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MONITORING OR TESTING THE PROGRESS OF RECORDING

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360 - Dynamic magnetic information storage or retrieval

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DocumentTitleDate
20130044387MEASURING VARIATIONS IN HEAD-DISK CLEARANCE IN A HARD DISK DRIVE - Methods and systems for measuring variations in head-disk clearance in a hard disk drive. User generated data is randomly selected at a controller of the hard disk drive wherein the user generated data is stored on a disk associated with the hard disk drive. A reference point associated with the user generated data is stored on a storage medium associated with the hard disk drive. The user generated data is read at the controller. The user generated data is analyzed with the reference point using more than two frequencies, at the controller, to obtain a variation in measurement of the head-disk clearance.02-21-2013
20100053789 MAGNETIC FIELD SENSOR CIRCUIT - A magnetic field sensor circuit comprises a first magneto-resistive sensor (Rx) which senses a first magnetic field component in a first direction to supply a first sense signal (Vx). A first flipping coil (FC1) applies a first flipping magnetic field with a periodically changing polarity to the first magneto-resistive sensor (Rx) to cause the first sense signal (Vx) to have alternating different levels synchronized with the first flipping magnetic field. A second magneto -resistive sensor (Ry) senses a second magnetic field component in a second direction different than the first direction to supply a second sense signal (Vy). A second flipping coil (FC2) applies a second flipping magnetic field with a periodically changing polarity to the second magneto -resistive sensor (Ry) to cause the second sense signal (Vy) to have an alternating different levels synchronized with the second flipping magnetic field. The first flipping magnetic field and the second flipping magnetic field have a phase shift. A differential amplifier (AMP1) receives the first sense signal (Vx) and the second sense signal (Vy) to obtain a difference signal (Vd). A first synchronous demodulator (DEM1) receives the difference signal (Vd) and a first switching signal (Q1) being phase locked to the alternating different levels of the first sense signal (Vx) to supply a first output signal (Vox) indicating the first magnetic field component. A second synchronous demodulator (DEM2) receives the difference signal (Vd) and a second switching signal (Q2) being phase locked to the alternating different levels of the second sense signal (Vy) to supply a second output signal (Voy) indicating the second magnetic field component.03-04-2010
20110205653Systems and Methods for Data Recovery - Various embodiments of the present invention provide systems and methods for identifying a reproducible location on a storage medium. As an example, a circuit is described that include a media defect detector and an anchor fixing circuit. The media defect detector is operable to identify a media defect, and the anchor fixing circuit is operable to identify a location relative to the media defect. The location is reproducible.08-25-2011
20090195902METHOD, SYSTEM, AND COMPUTER PROGRAM PRODUCT FOR ESTIMATING ADJACENT TRACK ERASURE RISK BY DETERMINING ERASE BAND WIDTH GROWTH RATES - A method according to one embodiment comprises determining a growth rate of an erase band width between an aggressor track and a substantially unerased portion of a data track on a magnetic medium during a first number of write cycles on the aggressor track; and estimating the erase band width, or derived parameter thereof, for or after a second number of write cycles on the aggressor track, the second number of write cycles being greater than the first number of write cycles.08-06-2009
20090195901Circuits for vcm back emf measurement with a bias voltage to control head flying location on disk - A hard disk drive with a voice coil motor coupled to a head. The head moves relative to a disk. The voice coil motor receives a biasing voltage and has a back emf voltage. A test circuit is coupled to the voice coil motor to determine the back emf voltage. The back emf voltage can be used to analyze low frequency vibration in the disk drive. The test circuit can be constructed so that the back emf voltage is proportional to a pair of test resistors and/or a pair of test inductors. The biasing voltage allows the back emf voltage to be measured and analyzed while the head is at any location from the ID to the OD of the disk.08-06-2009
20080259481Method of Using a Magnetic Sensor - A method of measuring an external magnetic field pointing in a first direction substantially parallel to a surface normal to an at least first magnetoresistive layered structure deposited on a planar substrate, the method comprising: applying the external magnetic field to the planar substrate having at least one structure of soft-magnetic material being adapted to at least partially deflect the external magnetic field in a direction substantially parallel to the surface of the at least first magnetoresistive layered structure, the at least one structure of soft-magnetic material being arranged in the vicinity of the at least first magnetoresistive layered structure; measuring the electrical resistance of the at least first magnetoresistive layered structure, the electrical resistance depending on the magnitude and/or direction of magnetic field being deflected by the at least one structure of soft-magnetic material, and determining at least one of the magnitude and direction of the external magnetic field using the electrical resistance of the at least first magnetoresistive layered structure.10-23-2008
20100073797STORAGE DEVICE AND METHOD OF CONTROLLING STORAGE DEVICE - According to one embodiment, a storage device includes a target track write module and a test pattern read module. The target track write module performs a write operation on a target track, which is a predetermined track intersecting a test pattern, on a storage medium to which the test pattern is written. The test pattern intersects a plurality of tracks arranged at regular intervals and is continuously arranged over the tracks. The test pattern read module reads the test pattern overwritten by the target track write module.03-25-2010
20100073796MAGNETIC FIELD SENSOR - A device for sensing a magnetic field is described. The device comprises first, second and third leads and a junction between the leads. The junction and leads are arranged in a plane and the junction is configured to exhibit quantum confinement in a direction perpendicular to the plane. The first lead is arranged on one side of the junction and the second and third leads are arranged on an opposite side of the junction. The first lead is configured to limit angle of spread of charge carriers entering the junction so that, when charge carriers flow into the junction from the first lead, the charge carriers form a substantially nondivergent beam.03-25-2010
20100073795FLYING HEIGHT CONTROL DEVICE FOR MAGNETIC HEAD, AND MAGNETIC DISK DEVICE - A flying height control device controls a flying height of a magnetic head, while preventing unnecessary execution of flying height control when read performance drops. A control circuit, which controls the flying height by controlling the heat power of a heater element of a magnetic head, checks the read performance, detects a drop in read performance, then judges and discerns which the cause of the drop in read performance is in the magnetic head and the magnetic disk, and executes the flying height control by the heat power correction processing when judging that the cause of the drop in read performance is in the magnetic head. Thus unnecessary adjustment while the magnetic disk device is operating is prevented.03-25-2010
20100033861ERROR BURST DETECTION AND AMELIORATION - A method according to one embodiment includes monitoring a data transfer operation for detecting temporary errors; determining whether art error burst has occurred based on the monitoring; if an error burst has occurred, altering a condition of the data transfer operation; monitoring the data transfer operation having the altered condition for detecting temporary errors; determining whether another error burst has occurred based on the monitoring of the data transfer operation having the altered condition; and if another error burst has occurred; altering another condition of the data transfer operation. Additional systems and methods are also presented.02-11-2010
20130038959DISK DRIVE WRITING SPIRAL TRACKS ON A SLAVE SURFACE USING REPEATABLE RUNOUT COMPENSATION FOR A MASTER SURFACE - A method is disclosed of servo writing a disk drive comprising a first head actuated over a first disk surface, and a second head actuated over a second disk surface. A first repeatable runout (RRO) of the first disk surface is measured, and a seek is performed to seek the first head over the first disk surface in response to the measured first RRO while writing a first spiral track to the second disk surface using the second head. As a result, the first spiral track comprises a second RRO that substantially matches the first RRO of the first disk surface.02-14-2013
20130033777SYSTEM AND METHOD OF SYNCHRONIZED WRITING ON BIT PATTERNED MEDIA WITH READ-WRITE OFFSET - A system and method of establishing write timing in a disk drive using bit patterned media and a magnetic head with read-write offset in which servoing and writing occur on different tracks with timing offsets. Initially, the distance between the servoing and writing tracks is determined for each track/head position in accordance with head geometry and skew angle. The relative timing errors are then measured by iteratively writing data at timing offset increments to determine the optimal timing offset for the servoing/writing track pair, and then writing the offset to sync fields on the servoing tracks of the disk.02-07-2013
20090185305METHOD AND SYSTEM FOR SERVO TRACK WRITE - A servo track writing method and a servo track write system of a hard disk drive (HDD) using the servo track write method. The servo track writing method includes performing a reference check (R/C) on a first servo pattern which is pre-written on a first surface of a disk, and if the R/C determines that a quality of the first servo pattern is not good, erasing a specific area of the first servo pattern and writing a second servo pattern on a second surface of the disk. Therefore, process time delay factors of a series of rework processes of writing servo patterns on a disk are removed to shorten a process time of the rework processes. In addition, productivity of a HDD is improved.07-23-2009
20100321812PROXIMITY DETECTION METHOD FOR MAGNETIC HEAD AND RECORDING MEDIUM - Touchdown is detected between an R/W head and disk by determining the variance in the frequency domain of a baseline position error signal (PES) and a PES measured after incrementally increasing the DFH control signal. To quantify the variance in the frequency domain, a discrete Fourier transform of the baseline PES and of each PES produced for a given DFH control signal is used. A band-limited PES variance is used to improve touchdown detection, but is not a requirement of this method.12-23-2010
20090153997METHOD OPERATING HARD DISK DRIVE ON THE BASIS OF PREDICTED DEFECT USING HIERARCHICAL CLUSTERING AND CURVE FIT - A method of operating a hard disk drive (HDD) on the basis of a predicted new defect in a disk associated with the HDD is disclosed. The method includes detecting defects in a magnetic surface of the disk, defining a plurality of clusters by grouping the detected defects using a hierarchical clustering algorithm, calculating a curve fit for each one of the plurality of clusters, predicting a new defect likely to occur in the magnetic surface of the disk on the basis of the calculated curve fit; and writing data to the disk on the basis of the new defect prediction.06-18-2009
20090153996USING SERVO DATA HARMONICS TO MONITOR HEAD-MEDIUM SPACING - A method is disclosed that includes measuring a first amplitude and a second amplitude in a servo pattern signal derived from a transducer head interacting with a medium; and providing an indication of a change in a spacing distance between the head and the medium, wherein the change in the spacing is evaluated using a spacing relation derived from a ratio of the first harmonic amplitude and the second harmonic amplitude.06-18-2009
20090153995Temperature coefficient of resistance measurement of TMR head using flying height control heater and determine maximum bias voltage of TMR heads - A method for determining whether a magneto-resistive head of a hard disk drive is defective for having an undesirable break down voltage. The method includes applying a voltage to a heater element of a magneto-resistive head and measuring a write element resistance and a read element resistance. A temperature coefficient of resistance for the read element is determined from the measured read and write element resistances. The head is considered defective if the temperature coefficient exceeds a threshold.06-18-2009
20090153993Disk Drive Testing - A disk drive testing system includes at least one robotic arm defining a first axis substantially normal to a floor surface. The robotic arm is operable to rotate through a predetermined arc about and extend radially from the first axis. Multiple racks are arranged around the robotic arm for servicing by the robotic arm. Each rack houses multiple test slots that are each configured to receive a disk drive transporter configured to carry a disk drive for testing. A transfer station is arranged for servicing by the robotic arm. The transfer station includes multiple tote receptacles that are each configured to receive a disk drive tote.06-18-2009
20090153992Disk Drive Testing - A disk drive testing system includes at least one robotic arm defining a first axis substantially normal to a floor surface. The robotic arm is operable to rotate through a predetermined arc about and extend radially from the first axis. Multiple racks are arranged around the robotic arm for servicing by the robotic arm. Each rack houses multiple test slots that are each configured to receive a disk drive transporter configured to carry a disk drive for testing.06-18-2009
20090128943Test method and manufaturing method of disk drive device in consideration of manufacturing efficiency - Embodiments of the present invention help to improve test processes for hard disk drives (HDDs) and increase the manufacturing efficiency of HDDs. According to one embodiment, a test process performs a test on an HDD with respect to a plurality of items and stores one or a plurality of test results. Moreover, it determines the optimum specification category to which the HDD is to belong based on the stored test results. One factor of the specifications—storage capacity—has been determined before the test process or is determined during the test process. The test process classifies HDDs with the same storage capacity into different specification categories, and this classification may be performed in a single test process. This achieves efficient manufacture of HDDs with different specifications corresponding to the diversified usage of HDDs.05-21-2009
20130027800METHOD OF TUNING SKEW BETWEEN READ HEAD AND WRITE HEAD AND STORAGE DEVICE THEREOF - Tuning a skew between a read head and a write head, may include setting a center value of a track according to a track density of a storage medium; writing data having a certain pattern to at least one target track and at least two tracks adjacent to the target track, while following the center value of the track; reading the data having a certain pattern from the target track by using a plurality of off track values in an off track range based on the center value of the track; and detecting an off track value having a minimum error occurrence number among error occurrence numbers with respect to the read data having a certain pattern corresponding to each of the plurality of off tracks, as an optimum off track value of the target track.01-31-2013
20100328802Servo Write Head Gap Width Correction - Embodiments include methods, apparatus, and systems for servo write head gap width correction. One method includes measuring a pulse mismatch for servo stripes on magnetic tape written with a servo write head having servo head gaps with different physical sizes, and separately energizing the servo head gaps to correct the pulse mismatch so servo stripes written on the magnetic tape are within a predefined tolerance.12-30-2010
20090147389Read sensor testing using thermal magnetic fluctuation noise spectra - A read head is tested by measuring the thermal magnetic fluctuation noise spectrum. A non-uniformity in the magnetic field of the free layer is produced and the thermal magnetic fluctuation noise spectrum is measured, with and/or without an external magnetic field applied. A peak in the thermal magnetic fluctuation noise spectrum can be used to derive the desired dimension of the free layer, such as track width and stripe height. The resulting measurement may then be fed back into the process control for the production of the read heads if desired. Additionally, the stiffness of the free layer and the strength of the reference layer may be determined using ferromagnetic resonance peaks in the thermal magnetic fluctuation noise spectrum.06-11-2009
20090103201SYSTEM, METHOD, AND APPARATUS FOR PERFORMING METROLOGY ON PATTERNED MEDIA DISKS WITH TEST PATTERN AREAS - Techniques for performing metrology on magnetic media disk formations that are arranged in curvilinear patterns are disclosed. Small integrated test patterns having rectangular or hexagonal periodicity are integrated among the concentric circles of patterned media formations. The test patterns cover only very small areas of the disk so as to not significantly affect disk capacity. The periodicity of the test patterns allows their formations to be more readily measured by metrology technology than those having a curvilinear periodicity.04-23-2009
20090303629MAGNETIC RECORDING/REPRODUCING APPARATUS AND METHOD FOR DETERMINING MAGNETIC RECORDING CONDITION - A magnetic recording/reproducing apparatus 12-10-2009
20090091853APPARATUS, SYSTEM, AND METHOD FOR INTERCHANGE TESTING - An apparatus, system, and method are disclosed for interchanging testing. A test module moves a first tape from a tape pool to a first reserved slot of plurality of reserved slots using an accessor. In an embodiment, there is one (1) reserved slot corresponding to each of a plurality of tape drives. Each reserved slot is configured to store one tape for the corresponding tape drive. No other tape drive accesses the stored tape from the reserved slot. Additionally, the test module loads the first tape to a first tape drive from the first reserved slot using the accessor, reads to end of at least two file marks on the first tape using the first tape drive, rewinds to a beginning of the first tape using the first tape drive, spaces forward on the first tape to a beginning of a second of the at least two file marks using the first tape drive, writes specified data to the first tape using the first tape drive, writes a new second file mark to the first tape using the first tape drive, and moves the first tape to the first reserved slot using the accessor.04-09-2009
20090296254Magnetic recording medium evaluation apparatus and evaluation method - This invention provides a magnetic recording medium evaluation apparatus and evaluation method which yield results having good correlation with error rate measurements even when comparing media with different structures. Signals from a function generator are recorded in a magnetic recording medium. The recording signals are also passed through a first digital filter to obtain ideal restored signals. Reproduced signals from the magnetic recording medium are sampled in synchronization with the output from the function generator, and the discrete signals are passed through a second digital filter to obtain restored signals. The outputs from the first and second digital filters are input to an operational amplifier, and the difference between the restored signals and the ideal restored signals is taken for each sampling of the recording signals. The signal-to-noise ratio of the ideal restored signal to the average of the absolute value of this difference is used to evaluate signal quality.12-03-2009
20110013305PROXIMITY DETECTION METHOD FOR MAGNETIC HEAD AND RECORDING MEDIUM - Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.01-20-2011
20090268330METHOD AND APPARATUS ESTIMATING TOUCH-DOWN APPROACH FLYING HEIGHT FOR MAGNETIC HEAD OF DISK DRIVE - A method and apparatus for controlling flying height for the read/write head of a HDD. The method uses the flying status of the head immediately before the head touches down on the disk to provide such control.10-29-2009
20090268329SLIDER TESTER AND METHOD FOR TESTING SLIDER - A slider tester includes a disk, movable table, table drive mechanism, guide member, etc. A plurality of suspensions are mounted on the movable table. A slider is mounted on each suspension. A guide member can support respective lift tabs of the suspensions. The guide member includes a first guide surface, second guide surface, and opening arranged in a track width direction of the disk. When any of the lift tabs gets into the opening as the movable table moves in the track width direction of the disk, the slider is dropped toward a recording surface of the disk.10-29-2009
20090268328METHOD OF EXAMINING STORAGE DISK AND STORAGE DISK EXAMINING APPARATUS - A method of examining a storage disk is proposed. The method repeats steps of: executing a writing operation and a reading operation in sequence to recording tracks at first intervals so as to check a defect in the recording tracks based on the quality of a read signal; and selecting a recording track at a position spaced by a second interval larger than the first interval from a last recording track of the sequence, the recording track being a first recording track of the recording tracks at the first intervals. The method realizes detection of a defect for recording tracks at the first intervals in a concentrated manner. A recording track is then selected at a position spaced by the second interval from the sequence. A defect can reliably be detected without increasing the total number of recording tracks selected as sample tracks.10-29-2009
20090268327CHARACTERISTICS EVALUATING METHOD AND CHARACTERISTICS EVALUATING APPARATUS FOR A MAGNETIC HEAD - A rotating support mechanism that rotates and supports the head slider between a position where the magnetic field generated by a magnetic field generating apparatus and a hard bias magnetic field of the head slider are antiparallel and a position where an air-bearing surface (ABS) of the head slider is perpendicular to the magnetic field; an external magnetic field applying unit for applying a static magnetic field to the head slider using the magnetic field generating apparatus at the position where the magnetic field generated by the magnetic field generating apparatus and the hard bias magnetic field of the head slider are antiparallel; and a unit for applying an alternating magnetic field onto the head slider using the magnetic field generating apparatus and carrying out measurement of ρH at the position where the ABS of the head slider is perpendicular to the magnetic field generated by the magnetic field generating apparatus.10-29-2009
20090268326Apparatus and method for improving bandwidth of a fine positioning mechanism data storage manufacturing and test equipment - An apparatus and a method for improving bandwidth of a fine positioning mechanism in data storage manufacturing and test equipment that require fine positioning of a head on or about a track. The method comprises the steps of sensing separate sources of mechanical disturbance that mis-position the head with one or more non-contact position sensors, generating a compensating position control signal from one or more input signals, and positioning the head with a fine positioning mechanism and position control signal. The apparatus uses a shear mode micro-actuator as a fine positioning mechanism.10-29-2009
20090268325METHODS FOR DETECTING DAMAGE TO MAGNETORESISTIVE SENSORS - In one embodiment, a method for detecting a damaged magnetoresistive sensor includes analyzing readback signals of a plurality of sensors each being positioned over data tracks on a passing magnetic medium; determining whether at least one of the readback signals is out of phase with respect to the other readback signals, and/or whether at least one of the readback signals has a significantly lower amplitude that the other readback signals. Additional methods are also presented.10-29-2009
20090268324METHODS FOR DETECTING DAMAGE TO MAGNETORESISTIVE SENSORS - A method for detecting a damaged magnetoresistive sensor in one embodiment comprises measuring a resistance of a first sensor upon application thereto of a positive bias current; measuring the resistance of the first sensor upon application thereto of a negative bias current; determining a difference in the measured resistances at positive and negative currents of the first sensor; measuring a resistance of a second sensor upon application thereto of a positive bias current; measuring the resistance of the second sensor upon application thereto of a negative bias current; determining a difference in the measured resistances at positive and negative currents of the second sensor; and outputting at least one of the differences, or a derivative of the at least one of the differences. Additional methods are also presented.10-29-2009
20090268323Method and System for Obtaining N and K Map for Measuring Fly-Height - A method for obtaining a refractive index (n) and extinction coefficient (k) map of a slider surface, the method comprising the steps of processing an image of the slider surface to obtain spatially resolved normalized intensity data of the slider surface; measuring n and k values of the slider surface at different areas of the slider surface to obtain reflectivity data of the slider surface; mapping a distribution of the normalized intensity data to a distribution of the reflectivity data for deriving the n and k map of the slider surface.10-29-2009
20130063834Head Assembly with Head-Media Spacing Control - A head assembly including one or more transducer elements for controlling head-media spacing is disclosed. The assembly includes detection circuitry configured to receive an input detection signal responsive to the spacing between the head and the data storage media and provide an output measure indicative of the head-media spacing. The output signal is utilized by control circuitry to provide a control input to one of a plurality of transducer elements on the head to protrude a localized portion of the head to adjust head-media spacing.03-14-2013
20100265608Systems and Methods for Storage Channel Testing - Various embodiments of the present invention provide systems and methods for validating elements of storage devices. A an example, various embodiments of the present invention provide semiconductor devices that include a write path circuit, a read path circuit and a validation circuit. The write path circuit is operable to receive a data input and to convert the data input into write data suitable for storage to a storage medium. The read path circuit is operable to receive read data and to convert the read data into a data output. The validation circuit is operable to: receive the write data, augment the write data with a first noise sequence to yield a first augmented data series; and augment a derivative of the first augmented data series with a second noise sequence to yield the read data.10-21-2010
20100123962SINGLE-PASS DEFECT DETECTION FOR HARD-DISK DRIVE SYSTEMS - In one embodiment, defects are detected on the face of a hard-disk drive platter. A preamble, a sync mark, user or pseudorandom data, and a data pad are written to every sector on a track of the platter. Inter-sector gaps that separate consecutive sectors are overwritten with a fixed data pattern such that consecutive sectors are in phase lock with one another. After the track has been written, the track is read back and analyzed. Consecutive sectors are analyzed continuously without stopping. The preambles, sync marks, data pads, and overwritten inter-sector gaps are analyzed using suitable flaw-scan techniques. The user or pseudorandom data is analyzed using both data-integrity checks and suitable flaw-scan techniques. This process is repeated for all tracks on the disk, and defect detection is completed when all tracks have been analyzed.05-20-2010
20090237824PATTERN WRITING SYSTEM AND PARAMETERS MONITORING METHOD FOR PATTERN WRITING APPARATUS - A pattern writing system includes a plurality of control units configured to use different communication standards; a pattern writing unit configured to be controlled by the plurality of control units and write a pattern on a target object by using a charged particle beam; a storage unit configured to receive parameter information from an external slave computer and stores the parameter information; a first interface information circuit group configured to output a received parameter information to at least one of the plurality of control units in conformity with a communication standard on the at least one of plurality of control units; a main computer; and a second interface circuit group configured to receive a request from the main computer, input parameter information been setting in the plurality of control units without passing through the storage unit, convert communication standards of the parameter information input into a communication standard used by the main computer, and output the parameter information whose each communication standard is converted to the main computer.09-24-2009
20120113538SIMULATING DISCRETE TRACK MEDIA WITH CONTINUOUS MEDIA FOR HEAD EVALUATION - Approaches for a testing device for selecting a discrete track media (DTM) format for use with a particular head of a hard-disk drive (HDD). The testing device comprises a continuous magnetic-recording disk, rotatably mounted on a spindle, which stores data using a continuous media format. The testing device also comprises a testing module configured to simulate reading data, stored using a discrete track media (DTM) format, from the continuous magnetic-recording medium. Advantageously, testing time and cost is reduced as both discrete track media (DTM) disks and expensive discrete track media (DTM) recording testing hardware are not required to select the optimal a discrete track media (DTM) format for use with a particular head of a hard-disk drive (HDD). In addition, embodiments may be used to optimize features of the tracks of the DTM disk, such as the land to groove ratio.05-10-2012
20100085654DATA TRANSFER ASSEMBLY PERFORMANCE CHARACTERISTICS TESTING - An apparatus is provided having a data transfer member, and a medium supported by a base adjacent the data transfer member. A medium tilting device supports the base and is selectively positionable to tilt the medium with respect to the data transfer member to simulate presenting the head to the medium at a desired angular orientation. A sensor measures a characteristic associated with a data transfer relationship between the data transfer member and the medium.04-08-2010
20130188271TAPE WIDTH MEASUREMENTS - A tape drive is disclosed. The tape drive determines a current tape width and writes data to the tape as well as the current tape width. The tape width written to the tape is associated with the data. When reading data from a tape the tape drive reads the stored tape width and adjusts the current tape width to match the stored tape width before reading the data associated with the stored tape width.07-25-2013
20120236427STORAGE APPARATUS AND CONTROLLER - A storage apparatus includes a plurality of first storage mediums in which data is redundantly stored and a controller. The controller includes a formatting section which performs formatting in each of the plurality of first storage mediums, a detection section which detects a failure that has occurred in the plurality of first storage mediums, a control section which makes the formatting section stop the formatting at the time of the detection of the failure by the detection section and which rebuilds the data stored in the plurality of first storage mediums in which the failure has occurred in a second storage medium other than the plurality of first storage mediums, and a rebuild processing section which rebuilds the data stored in the plurality of first storage mediums in the second storage medium in accordance with instructions from the control section.09-20-2012
20090231743Testing method for thin-film magnetic head and jig used therefor - In testing thin-film magnetic heads, first, a back surface opposite to a medium facing surface of each of a plurality of thin-film magnetic heads is attached to a first surface of a first plate of a jig, the jig including the first plate of rubber having the first and second surfaces facing toward opposite directions, and a second plate greater in rigidity than the first plate and bonded to the second surface of the first plate. Next, the plurality of thin-film magnetic heads and the jig are mounted on a metal plate having a flat top surface, such that the medium facing surfaces of the thin-film magnetic heads touch the top surface of the metal plate. Next, heat-generating components of the plurality of thin-film magnetic heads mounted on the metal plate are energized.09-17-2009
20110242691Systems and Methods for Detecting Head Contact - Various embodiments of the present invention provide systems and methods for determining contact with a storage medium. As an example, a data storage system is disclosed that includes: a head assembly and a data processing circuit. The head includes a head disk interface sensor operable to provide a contact signal indicating contact between the head and a storage medium disposed in relation to the head. The data processing circuit is operable to process the contact signal to yield an indication of a contact between the storage medium and the head.10-06-2011
20100061003ROTARY DISK ECCENTRICITY MEASUREMENT METHOD, ROTARY ENCODER, AND ROTARY MEMBER CONTROL DEVICE - An eccentricity measurement method of measuring the eccentricity between a center of a connection portion of a rotary disk of a rotary encoder connected to a rotary shaft of a rotary member, and a center of a scale provided at the periphery of the rotary disk. The method includes forming, on the rotary disk, a circle pattern concentric with the scale and at least three straight-line patterns intersecting or contacting the circle pattern and the connection portion; and measuring an amount and direction of the eccentricity of the rotary disk by comparing a coordinate of the center of the connection portion, calculated from coordinates of intersections of the straight-line patterns and the connection portion, with a coordinate of the center of the scale, calculated from the coordinates of intersections of the straight-line patterns and the circle pattern.03-11-2010
20100202078READ/WRITE PROCESSING METHOD FOR MEDIUM RECORDING DEVICE AND MEDIUM RECORDING DEVICE - According to one embodiment, a medium recording device includes a reading/writing module configured to read/write data from/to a recording medium, a buffer memory configured to temporarily store the read data and data from a host, and a controlling circuit configured to, in response to a read command, read data from the buffer memory or the recording medium to transfer the data to the host, and in response to a write command, to store data from the host in the buffer memory, to write the data onto the recording medium, and to execute a write retry when writing fails. The controller circuit recognizes a read command issued by the host at a fixed interval for replaying continuous data, and determines whether write in response to a write command received during the replaying is likely to fail, and when the write is likely to fail, permits a reception of the read command issued at the fixed interval.08-12-2010
20090290247Abnormality determining apparatus - In a RAID apparatus, an error determining processing unit determines whether an HDD is normal based on an error determining condition obtained from an amount of increase of NON MEDIUM ERROR COUNT and the number of accesses memorized on a control table, and detects the HDD with abnormal performance.11-26-2009
20110273793DETERMINATION OF TIMING BASED SERVO PATTERN TYPE - In a magnetic tape drive having a servo read system with at least one read head, the system configured to read servo pattern information as a magnetic tape is moved longitudinally with respect to the at least one read head, the servo pattern comprising a timing-based servo pattern comprising an even number of bursts of sloped magnetic stripes, adjacent bursts oppositely sloped, alternate bursts identically sloped, an embodiment of a method determines the time between detection from the read head of a same stripe of alternate bursts of a pattern; determines the time between detection from the read head of stripes of a burst of a pattern; and determines a ratio of the determined times. The ratio is compared to a threshold, wherein the threshold comprises a differentiation between different servo pattern types.11-10-2011
20090207516Iterative repeatable run-out nulling for magnetic head tester - A method for operating a head testing apparatus or, more generally, a host hard disk drive using a mounted hard disk that has had its servo track information pre-written in an external servo-writing apparatus rather than in the head testing or host apparatus itself. The method eliminates repeatable errors and repeatable runout by effectively replacing the pre-written servo tracks, which are eccentric, with new track profiles that are tracked like circular tracks. The problem of repeatable errors is caused by repeatable runout superimposed upon written-in position errors when a disk written in one machine is transferred to another. This problem is eliminated by forming IRON (Iterative Repeatable Runout Nulling) profile tracks from the initially pre-written servo tracks, where the IRON profile tracks are effectively tracked as concentric circular tracks and generate no PES. The IRON profile is formed by an iterative method that starts with the measurement of the PES of one of the pre-written tracks and iteratively forms a new track profile that is effectively circular.08-20-2009
20110286125PATTERNED-MEDIA MAGNETIC RECORDING DISK DRIVE WITH DATA ISLAND MISPLACEMENT INFORMATION IN THE SERVO SECTORS - A disk drive with patterned-media disks has information recorded in the servo sectors that identifies misplacement of the data islands in the data regions between the servo sectors. This misplacement information is read from the servo sectors prior to writing to correct either or both the radial position of the write head and the timing of the write pulses to the data islands. The misplacement information may include radial deviation of the data tracks, circumferential or along-the-track misplacement of the data islands, or the location of defective data islands.11-24-2011
20120002316MAGNETIC RECORDING APPARATUS AND METHOD OF TESTING MAGNETIC RECORDING APPARATUS - According to one embodiment, there is provided a magnetic recording apparatus including a head slider including read and write elements, and a magnetic recording medium including magnetically recordable recording tracks with a width L01-05-2012
20120002315MAGNETIC DISK DRIVE AND REFRESH METHOD FOR THE SAME - According to one embodiment, a magnetic disk drive includes a grouping module and a refresh controller. The grouping module partitions a set of tracks on a disk into a plurality of groups. Each of the plurality of groups includes a plurality of tracks including at least two tracks with nonconsecutive physical positions. The refresh controller controls refresh process for each of the plurality of groups.01-05-2012
20120008225Fly Capable Slider Test Socket - The present application is directed to a slider supporting apparatus for flying a slider of a hard disk drive in the manufacturing process to provide electrical performance characteristics. The present invention discloses an integrated design including the electrical interconnect, the gimballing mechanism, the preload mechanism and the slider supporting mechanism integrated into a single supporting structure.01-12-2012
20110292533MAGNETIC DISK DRIVE AND METHOD FOR REWRITING DATA BLOCK - According to one embodiment, a magnetic disk includes a disk, a controller and an indicator module. The disk includes a plurality of data sectors. The controller is configured to control data rewrite for reading a first data block stored in the disk and writing a second data block corresponding to the read first data block to a write destination on the disk. The indicator module is configured to embed an indicator indicative of an attribute relating to data rewrite in each sector data in the second data block written to the write destination when the each sector data is written to the write destination.12-01-2011
20110292532STORAGE DEVICE AND METHOD FOR CONTROLLING PROJECTION AMOUNT OF HEAD - According to one embodiment, a storage device includes a recording medium, a driving module, a head, a conductive body, a write-verify module, and a projection amount controller. A conductive body is mounted on the head, and changes a projection amount of the head by thermally expanding the head with heat from a current carried by the conductive body. The write-verify module executes a write-verify check to check whether content written in any location on the recording medium is correct when the driving module starts rotating the recording medium. The projection amount controller controls the projection amount of the head by adding a first value to a current in a steady state carried by the conductive body if the content is correct, and adding a second value with an absolute value greater than that of the first value to the current in the steady state if the content is not correct.12-01-2011
20110292531DRIVE APPARATUS, LIBRARY APPARATUS, AND CONTROL METHOD THEREOF - A magnetic tape apparatus performs at least one of data reading processing and data writing processing on LTO wound around a reel. The magnetic tape apparatus causes the reel to rotate and move the LTO to a position at which the data writing processing or the data reading processing can be performed by a magnetic head. The magnetic tape apparatus is arranged along the width direction of the magnetic tape of LTO, which is driven, to detect medium abnormality that occurred in either a start-end or a stop-end in the width direction of the magnetic tape.12-01-2011
20090109563BURST INTERVAL MEASURING APPARATUS, BURST INTERVAL MEASURING METHOD, DRIVE APPARATUS, SERVO PATTERN WRITING APPARATUS, AND MAGNETIC TAPE TESTING APPARATUS - A burst interval measuring apparatus includes: a detector that outputs detection signals that can to measure a burst interval of servo patterns for a tracking servo; and a measuring unit that measures the burst interval based on the detection signals. The detector is constructed so as to be capable of outputting the detection signals that can measure the burst interval at plural positions that are separated in a width direction of the magnetic tape inside one of the servo patterns. The measuring unit uses measurement values for the burst interval at at least two positions out of the plural positions that have been measured based on the detection signals to specify velocity fluctuations in a movement velocity of the magnetic tape in the length direction and corrects the measurement values based on the velocity fluctuations.04-30-2009
20090296253CONTROL APPARATUS, STORAGE DEVICE, AND SYSTEM-INFORMATION STORAGE METHOD - A magnetic disk device performs test write to check the state of each of heads before system information is stored in a disk and, based on the result of the test write, stores the system information sequentially with the heads from one in good state. After a predetermined time has elapsed, the magnetic disk device suspends the process of storing the system information.12-03-2009
20090323210SHROUD FOR HEAD GIMBAL ASSEMBLY TESTING - In one implementation, an assembly for testing a head gimbal assembly comprises a rotatable test disc, a mounting surface configured to mount the head gimbal assembly, and a shroud covering the head gimbal assembly. The mounting surface is located in proximity to the test disc to facilitate loading the head gimbal assembly on the test disc. The shroud is configured to shield the head gimbal assembly from airflow produced when the test disc rotates.12-31-2009
20090128942Method for Determining Wear of a Data Storage Medium and Data Storage Device - The invention relates to a method of determining wear of a data storage medium actively by performing a read operation on the data storage medium and detecting a read signal, comparing the read signal to at least one wear threshold; and determining a wear level of an area of the data storage medium based on the comparison. The wear threshold is lower than a detection threshold, wherein the detection of the read signal above the detection threshold indicates the presence of stored data.05-21-2009
20100033862Inspection Apparatus and Inspection Method of Magnetic Disk or Magnetic Head - The present invention provides a technique for converting burst data to digital data, applying FFT operation to 202-11-2010
20100033860Proximity Detection Method For Magnetic Head And Recording Medium - Touchdown is detected between an R/W head and disk by determining the variance in the frequency domain of a baseline position error signal (PES) and a PES measured after incrementally increasing the DFH control signal. To quantify the variance in the frequency domain, a discrete Fourier transform of the baseline PES and of each PES produced for a given DFH control signal is used. A band-limited PES variance is used to improve touchdown detection, but is not a requirement of this method.02-11-2010
20090195903METHOD OF EVALUATING MAGNETORESISTIVE HEAD - The method is capable of perfectly detecting unstably magnetized magnetoresistive heads. The method of evaluating a magnetoresistive head comprises the steps of: applying a magnetic field to the magnetoresistive head, in the direction parallel to an air bearing surface of the magnetoresistive head, at a prescribed temperature; obtaining an image of the air bearing surface in a first magnetized state by using the Kerr effect; applying an external stress to the magnetoresistive head; obtaining an image of the air bearing surface in a second magnetized state by using the Kerr effect; and evaluating characteristics of the magnetoresistive head on the basis of the images of the first magnetized state and the second magnetized state or by comparing the images of the first magnetized state and the second magnetized state.08-06-2009
20090244752HEAD SPACING VERIFICATION IN MAGNETIC DISK DRIVE SYSTEMS DURING END-USER OPERATION - Magnetic disk drive systems and associated methods are described for verifying a spacing between read/write heads on a slider and a magnetic recording disk during end-user operation. An operating power applied to heating elements in the slider controls the spacing due to thermal protrusion. While in end-user operation, the operating power is temporarily increased to a test power to decrease the spacing. The test power is then evaluated to determine if contact between the read/write heads and the magnetic recording disk is detected. If contact is not detected, then the spacing due to the operating power is determined to be adequate. If contact is detected, then the operating power is recalibrated.10-01-2009
20090190245HEAD EVALUATION METHOD, MAGNETIC STORAGE APPARATUS AND COMPUTER-READABLE STORAGE MEDIUM - A head evaluation method obtains a first measured result indicating a change in read data, by writing data on and reading data from the disk rotated at a first speed, and reading the data from the disk rotated at a second speed higher than the first speed while maintaining a floating amount of a head the same as that when the disk is rotated at the first speed. A second measured result indicating a change in read data is obtained by writing data on and reading data from the disk rotated at the second speed, and reading the data from the disk rotated at the first speed while maintaining the floating amount of the head the same as that when the disk is rotated at the second speed. The head is evaluated based on the first and second measured results, and a primary factor of a characteristic change of the head depending solely on a transfer rate is evaluated.07-30-2009
20090097148Head test apparatus and head test analysis system - A head test apparatus includes a loading section that installs the head; a head operation section that causes the head installed in the loading section to execute a test access; a test section that examines the head by judging whether a test access signal obtained from the head when the test access is executed satisfies a predetermined reference; a signal output section that obtains the test access signal and outputs the obtained test access signal to an exterior of the head test apparatus; and a reference output section that outputs a reference signal which is used for taking, in the exterior of the head test apparatus, the test access signal that the signal output section outputs in synchronism with an acquisition of the head test access.04-16-2009
20090153994Disk Drive Transport, Clamping and Testing - A disk drive transporter, for transporting a disk drive and for mounting a disk drive within a test slot, includes a frame configured to receive and support a disk drive. The frame includes sidewalls configured to receive a disk drive therebetween and sized to be inserted into a test slot along with a disk drive. The frame also includes a clamping mechanism operatively associated with at least one of the sidewalls. The clamping mechanism includes a first engagement element and a first actuator operable to initiate movements of the first engagement element. The first actuator is operable to move the first engagement element into engagement with a test slot after a disk drive being supported by the frame is arranged in a test position in a test slot.06-18-2009
20100128376MAGNETIC DISK DRIVE HAVING ASSISTED RECORDING AND METHODS OF RECORDING DATA THERETO - In one embodiment, a magnetic disk drive includes a magnetic disk, a head slider for flying above the spinning magnetic disk, a pattern analyzer for analyzing a data pattern of data to be recorded on the magnetic disk to determine a recording current reversal timing and a recording assistance area in accordance with the analysis so that the rear end of the determined recording assistance area is shifted forward if the determined recording current reversal timing is earlier than a criterion, or the rear end of the determined recording assistance area is shifted backward if the determined recording current reversal timing is later than the criterion, a recording assistance element on the slider for forming the determined recording assistance area on the magnetic disk, and a recording element for recording the data on the magnetic disk using the recording current in accordance with the determined recording current reversal timing.05-27-2010
20080266692MAGNETIC DISK DEVICE AND DATA WRITING METHOD THEREOF - A data writing method to write data on a disk in a disk device. The data is written in one radial direction. The method includes detecting a first deviation amount from a center in a current track and sector in the direction of a track on which data was previously written. A second deviation amount from the center in the current track and sector in the direction of a track on which data will be subsequently written is also detected. Data is written on the current track when the first deviation amount is equal to or smaller than a first threshold and the second deviation amount is equal to or smaller than a second threshold.10-30-2008
20090310240CODING TECHNIQUE FOR CORRECTING MEDIA DEFECT-RELATED ERRORS AND RANDOM ERRORS - A method of writing data on a storage medium that takes into account a condition of the storage medium. The method includes receiving data to be written on a portion of a storage medium and encoding the data based on a condition of the portion of the storage medium. The encoded data is written on the portion of the storage medium. A data storage system that includes a storage medium having defects is also provided. The data storage system utilizes a coding scheme that comprises coding bit patterns configured to address the defects on the storage medium.12-17-2009
20100123964STORAGE DEVICE AND CONTROL DEVICE - According to one embodiment, a vibration correspondence information storage module stores, each time process such as reading and writing is performed, a head performing the process, a vibration amount of the head upon performing the process, and a process retry count in association with one another as vibration correspondence information. A process completion prediction time calculator calculates, upon determining a next execution command from among unexecuted read and write commands, process completion prediction time based on arrival time taken for a scheduled execution head to arrive at a scheduled process position from the current position, and a process retry count associated with the scheduled execution head and a current vibration amount thereof in the vibration correspondence information. A next execution command determining module determines the next execution command based on the process completion prediction time.05-20-2010
20100123963MAGNETIC STORAGE APPARATUS, HEAD TEST METHOD, AND HEAD TEST APPARATUS - According to one embodiment, a magnetic storage apparatus configured to write data to and read data from a magnetic medium with a head includes a setting module, a write module, a read module, and a quality measurement module. The setting module sets a plurality of sections divided in the track direction of the magnetic medium and a predetermined reference path along the track direction, and also sets at least one offset for each of the sections such that the offset is different between adjacent sections. The offset is the position of the head with respect to the reference path. The write module writes a first data pattern to the offset set by the setting module and writes a second data pattern to the reference path a predetermined number of times. The read module reads the first data pattern written by the write module. The quality measurement module measures the quality of the first data pattern read by the read module.05-20-2010
20100118425DISTURBANCE REJECTION IN A SERVO CONTROL LOOP USING PRESSURE-BASED DISC MODE SENSOR - Vibration of a rotatable disc is sensed using a pressure sensor positioned adjacent to and spaced apart from a surface of the rotatable disc. The pressure sensor detects pressure variation caused by vibration of the rotatable disc.05-13-2010
20100027149OSCILLATION TEST FOR OFF TRACK WRITE - An enhanced oscillation test for detecting off track writing associated with a read/write head writing, on a magnetic media, a measurement track. Once the measurement track is written, a series of seek, write, and read operations is performed, e.g., between various origin tracks and the tracks adjacent to the measurement track, in order to detect any off track write problems. If a measurement track read operation fails a certain number of times, then an error code is generated which indicates an off track write problem.02-04-2010
20100118424MEASUREMENT OF ROUND TRIP LATENCY IN WRITE AND READ PATHS - A method and apparatus for measuring latency in a communication path is provided. The technique includes driving a signal such as a square wave on the communication path, such as a write path such that it travels around the write-read path, and sensing a returned signal at one end of the write-read path. A square wave signal corresponding to the square wave driven on the write path is delayed by a predetermined phase thus generating a delayed signal. The returned signal and the delayed signal are mixed, producing a mixed signal. The mixed signal is integrated to obtain an integrated output. The phase by which the delayed signal is shifted is successively adjusted. Returned signals are mixed with such delayed signals until the integrated output is equal to zero. The phase shift amount that results in a nulled integrated output, less a quarter cycle of the square wave, is equal to the round trip latency of the write-read path.05-13-2010
20120033318PLANAR SLIDER TEST SOCKET - The present application is directed to a slider supporting apparatus for flying a slider of a hard disk drive in the manufacturing process to provide electrical performance characteristics. The present invention discloses an integrated design including the electrical interconnect, the gimballing mechanism, the preload mechanism and the slider supporting mechanism integrated into a single supporting structure.02-09-2012
20120033316Systems and Methods for Format Efficient Calibration for Servo Data Based Harmonics Calculation - Various embodiments of the present invention provide systems and methods for servo data based harmonics calculation. For example, a method for calculating harmonics is disclosed that includes: providing a data processing circuit; receiving a first data set derived from a data source during a servo data processing period; performing a first harmonics calculation using the first data set to yield a first harmonics ratio; receiving a second data set derived from a source other than the previously mentioned data source during a user data processing period; performing a second harmonics calculation using the second data set to yield a second harmonics ratio; and calculating a ratio of the first harmonics ratio to the second harmonics ratio.02-09-2012
20110188144SERVO ROUTINE FOR TRACK SEEKING IN A HARD DISK DRIVE AND HARD DISK DRIVE FOR PERFORMING THE SAME - A method for controlling a hard disk drive, includes a track seeking servo routine in which seek time is measured in a mode of the routine after the trajectory mode, the measured seek time is compared with a predetermined period of time, and an alarm mode is induced when the measured seek time exceeds the predetermined period of seek time.08-04-2011
20100079889Systems and Methods for Storing Data to Magnetic Tape Having Damaged Areas - A method for using magnetic tape having damaged areas is disclosed. The method may include writing data to streaming magnetic tape, determining if the data write was successful, and responding to an unsuccessful data write by interrupting the data writing and advancing the magnetic tape forward a predetermined distance. Additionally, the method may include attempting to write data at the next location on the magnetic tape and determining if the data write was successful. The method may further include repeating the steps of advancing the tape, attempting to write, and determining whether the data write was successful following any determination that an attempted data write was not successful. The method may include further include resuming writing data to streaming magnetic tape at a location where a data write is determined to be successful.04-01-2010
20100265610DISK DRIVE TRANSPORT, CLAMPING AND TESTING - A disk drive transporter, for transporting a disk drive and for mounting a disk drive within a test slot, includes a frame configured to receive and support a disk drive. The frame includes sidewalls configured to receive a disk drive therebetween and sized to be inserted into a test slot along with a disk drive. The frame also includes a clamping mechanism operatively associated with at least one of the sidewalls. The clamping mechanism includes a first engagement element and a first actuator operable to initiate movements of the first engagement element. The first actuator is operable to move the first engagement element into engagement with a test slot after a disk drive being supported by the frame is arranged in a test position in a test slot.10-21-2010
20110199699FREQUENCY-BASED APPROACH FOR DETECTION AND CLASSIFICATION OF HARD-DISC DEFECT REGIONS - In a hard-disc drive read channel, frequency-based measures are generated at two different data frequencies (e.g., 2T and DC) by applying a transform, such as a discrete Fourier transform (DFT), to signal values, such as ADC or equalizer output values, corresponding to, e.g., a 2T data pattern stored on the hard disc. The frequency-based measures are used to detect defect regions on the hard disc and/or to classify defect regions as being due to either thermal asperity (TA) or drop-out media defect (MD).08-18-2011
20090201598Disc drive device - Embodiments of the present invention precisely measure clearance variation by temperature change using a value in a RW channel. In an embodiment of the present invention, an HDD measures resolution by signals in a RW channel. The measured resolution shows variations depending on temperature according to two factors. One factor is the clearance variation depending on the temperature and the other is the variation in operational property of the RW channel depending on the temperature. The HDD compensates for the temperature variation of the resolution according to the two factors. The HDD uses two kinds of sensed temperature. One corresponds to the temperature inside an enclosure in which head sliders are provided and the other corresponds to the temperature of the chip in which the RW channel is implemented. Sensing the drive temperature and the channel temperature independently achieves precise compensation for the variation in the measured resolution caused by clearance variation and channel property.08-13-2009
20110170212METHOD AND APPARATUS FOR PREVENTING DATA LOSS IN HARD DISK DRIVE - A method of preventing data loss in a hard disk drive comprises detecting a write error, performing a write retry operation upon detection of the write error, and storing write retry information in a non-volatile memory before performing the write retry operation. The write retry information comprises location information and data for a sector to be rewritten in the write retry operation.07-14-2011
20090284857METHOD AND APPARATUS FOR TESTING CHARACTERISTICS OF THIN-FILM MAGNETIC HEAD - The characteristics of thin-film magnetic heads are evaluated by measuring, in a step and repeat method and apparatus, the magnetic field generated by the respective heads in a bar including multiple heads.11-19-2009
20090147390Detecting head/disk contact using timing jitter - A disk drive that includes a head and a disk. The disk drive also includes a circuit that can detect head/disk contact from a jitter determined from a read signal provided by the head. The jitter may correspond to the time interval between two detected sync marks. Alternatively, the jitter may correspond to a change in frequency of a read clock generated from the read signal. These approaches allow for detection of head movement in a down track direction. Down track is a direction that is essentially parallel with the longitudinal axis of the head.06-11-2009
20090290249MANAGEMENT APPARATUS, STORAGE SYSTEM, AND STORAGE APPARATUS MANAGEMENT METHOD - There is provided a management apparatus of a storage apparatus. The management apparatus includes an acquisition determination section that determines whether predetermined identification information can be acquired or not from a mounting apparatus that mounts at least one storage apparatus and has at least one predetermined identification information assigned thereto, and a failure determination section that determines, based on a determination result of the acquisition determination section, an access failure to the storage apparatus mounted in the mounting apparatus has been caused due to a failure of the storage apparatus itself or an interruption of a power supply to the mounting apparatus.11-26-2009
20090262446METHOD FOR MEASURING WRITE WIDTH AND/OR READ WIDTH OF A COMPOSITE MAGNETIC HEAD AND A MEASURING DEVICE USING THE METHOD - A write sensitive width is calculated by writing a test data by a write head by moving the write head in a radial direction of a magnetic recording medium at a designated speed K to obliquely cross a designated track or a track adjacent to the designated track, reading the test data recorded in the track obliquely by a read head to obtain a read characteristics profile of a read voltage with respect to the track scanning time and obtaining a moving distance in the radial direction of the head by multiplying the test data scanning time of the read head with the designated moving speed K.10-22-2009
20090262445Bulk Feeding Disk Drives to Disk Drive Testing Systems - A method of supplying disk drives to a disk drive testing system includes placing a disk drive tote, carrying multiple disk drives, in a presentation position accessible to an automated transporter of the disk drive testing system. The method includes actuating the automated transporter to retrieve one of the disk drives from the disk drive tote, and actuating the automated transporter to deliver the retrieved disk drive to a test slot of the disk drive testing system and insert the disk drive in the test slot.10-22-2009
20090262444Transferring Disk Drives Within Disk Drive Testing Systems - A method of transferring disk drives within a disk drive testing system includes actuating an automated transporter to retrieve multiple disk drives presented for testing, and actuating the automated transporter to deliver each retrieved disk drive to a respective test slot of the disk drive testing system and insert each disk drive in the respective test slot.10-22-2009
20090273854METHOD FOR SCREENING MAGNETIC-RECORDING HEADS - A method for screening a magnetic-recording head utilizing a simulated-cross-track-gain profile of the magnetic-recording head to provide a manufacturing-qualified, magnetic-recording head. The method includes measuring a track profile of the magnetic-recording head, and providing the simulated-cross-track-gain profile of the magnetic-recording head synthesized utilizing the track profile of the magnetic-recording head. The method also includes calculating a peak-to-peak value of the simulated-cross-track-gain profile, and applying a selection criterion based on the peak-to-peak value of the simulated-cross-track-gain profile to screen the magnetic-recording head for use as the manufacturing-qualified, magnetic-recording head.11-05-2009
20090273855Method for measuring pole width of a slider of a disk drive device - A method for measuring pole width of a slider of a disk drive includes steps of: getting an original image of the pole surface; calculating the light intensity distribution profile of the original image and determining maximum and minimum light intensity data points of the profile; setting average of the maximum and minimum light intensity data points as a threshold; carrying out quadratic differentiation of the profile to obtain a quadratic differential asymptote; determining cross points between the quadratic differential asymptote and the threshold; calculating the distance between the cross points to obtain an initial pole width; and performing data compensation to the initial pole width to obtain a compensated pole width. The method may also measure the distance between edges of other micro-objects.11-05-2009
20090279197SERVO SIGNAL RECORDING APPARATUS - A servo signal recording apparatus of the present invention is provided with a tape motion measurement unit 11-12-2009
20090296251CONTROL APPARATUS, STORAGE DEVICE, AND TIMEOUT-POSSIBILITY NOTIFYING METHOD - A magnetic disk device performs test write on a test cylinder to check the state of each head before system information is stored in disks. The magnetic disk device then determines the state of each head based on the test write results stored in a test-write-result table. When a head is defective, the magnetic disk device notifies a host of the possibility of the occurrence of a timeout as a fault prediction.12-03-2009
20090284858MAGNETIC RECORDING APPARATUS AND CLOCK SIGNAL GENERATING METHOD - According to an aspect of the embodiment, in a magnetic recording apparatus having a magnetic recording medium of a patterned media system, a voltage generated between both terminals of a magnetic field generating coil in a case that a DC current is supplied to a recording element of a magnetic head is measured by a voltage measuring circuit in order to perform accurate recording at the center of each of magnetic body regions sectioned with non-magnetic body regions. Based on the measured voltage, a change in coil inductance in passage of the magnetic head over a magnetic body region and a non-magnetic body region in a patterned media is detected by a voltage change detecting circuit. A write clock signal which synchronizes with the change in coil inductance is generated by a clock signal generating circuit.11-19-2009
20090290248PRESSING HEAD STRUCTURE FOR TESTING KEY DURABILITY - A pressing head structure (11-26-2009
20090296252CONTROL APPARATUS, STORAGE DEVICE, AND SYSTEM-INFORMATION STORAGE METHOD - A magnetic disk device performs test write before storing system information to check the state of each head. The magnetic disk device then stores test write results in a test-write-result table of a RAM. The magnetic disk device then determines whether the number of defective heads is equal to or greater than a predetermined number. When the number of defective heads is equal to or greater than the predetermined number, the magnetic disk device suspends the process of storing the system information. When the number of defective heads is less than the predetermined number, the magnetic disk device refers to the test write results stored in the test-write-result table and performs write only with a head determined as normal.12-03-2009
20090168217Test-device system for independent characterization of sensor-width and sensor-stripe-height definition processses - A test-device system and method for deconvoluting measurements of effects of a sensor-width definition process from measurements of effects of a sensor-stripe-height-definition process in a manufacture of a magnetic sensor. The test-device system comprises a first test device for generating data to characterize a sensor-width-definition process. The test-device system also comprises a second test device for generating data to characterize a sensor-stripe-height-definition process. The test-device system allows independent characterization of a sensor-width parameter and a sensor-stripe-height parameter.07-02-2009
20090168216TEST COMPONENTS FABRICATED WITH PSEUDO SENSORS USED FOR DETERMINING THE RESISTANCE OF AN MR SENSOR - Test methods and components are disclosed for testing resistances of magnetoresistance (MR) sensors in read elements. Test components are fabricated on a wafer with a first test lead, a pseudo sensor, and a second test lead. The test leads and MR sensor are fabricated with similar processes as first shields, MR sensors, and second shields of read elements on the wafer. However, the pseudo sensor in the test component is fabricated with lead material (or another material having similar resistance properties) instead of an MR thin-film structure like an MR sensor. Forming the pseudo sensor from lead material causes the resistance of the pseudo sensor to be insignificant compared to the lead resistance. Thus, a resistance measurement of the test component represents the lead resistance of a read element. An accurate resistance measurement of an MR sensor in a read element may then be determined by subtracting the lead resistance.07-02-2009
20090168215TEST COMPONENTS FABRICATED WITH LARGE AREA SENSORS USED FOR DETERMINING THE RESISTANCE OF AN MR SENSOR - Test methods and components are disclosed for testing resistances of magnetoresistance (MR) sensors in read elements. Test components are fabricated on a wafer with a first test lead, a test MR sensor, and a second test lead. The test leads and test MR sensor are fabricated with similar processes as first shields, MR sensors, and second shields of read elements on tie wafer. However, the test MR sensor is fabricated with an area that is larger than areas of the MR sensors in the read elements. The larger area of the test MR sensor causes the resistance of the test MR sensor to be insignificant compared to the lead resistance. Thus, a resistance measurement of the test component represents the lead resistance of a read element. An accurate resistance measurement of an MR sensor in a read element may then be determined by subtracting the lead resistance.07-02-2009
20090168213VERIFICATION OF A GROUND CONNECTION FABRICATION PROCESS FOR ESD RESISTORS IN MAGNETIC HEADS - Test methods and components are disclosed for testing the quality of the ground connection fabrication process for ESD shunt resistors in magnetic heads. A wafer is populated with one or more test components along with magnetic heads. The test components are fabricated with ESD shunt resistor ground connections created by the same or similar process used to fabricate the ESD shunt resistor ground connections in magnetic heads on the wafer. The resistance of the test component ground connections may then be measured in order to determine the quality of the ground connections formed by the fabrication process. The quality of the ground connection fabrication process may then be determined based on the measured resistance of the test components.07-02-2009
20090168214VERIFICATION OF A FABRICATION PROCESS USED TO FORM READ ELEMENTS IN MAGNETIC HEADS - Test methods and components are disclosed for testing the quality of a fabrication process used to form read elements in magnetic heads. A wafer is populated with one or more test components along with magnetic heads. The test components are formed by the same or similar fabrication processes as the read elements, but do not include a conductive MR sensor between the test leads. By measuring the resistance of the test components, the formation of parasitic shunts can be identified in the test components, which may indicate the formation of parasitic shunts in the read elements. Thus, the quality of the fabrication process in forming read elements in magnetic head may be determined.07-02-2009
20110205654CONTROL APPARATUS, NONVOLATILE STORAGE APPARATUS AND DATA INITIALIZATION METHOD - A control apparatus for controlling initialization of data stored in a storage unit in response to receipt of an initialization instruction from a host system, includes (a) a register unit that stores inversion bit information indicating a plurality of bits to be inverted in data readout process, (b) a data receiving unit that receives read data and an error correcting code corresponding to the read data, and (c) an inversion unit that inverts part of bits of at least one of the read data and the error correcting code corresponding to the read data on the basis of the inversion bit information in the data readout process after the receipt of the initialization instruction. In the above (a), the plurality of bits to be inverted being part of bits of at least one of read data and an error correcting code corresponding to the read data.08-25-2011
20100103552Method for Distinguishing Unbalanced Disc - A method for distinguishing unbalanced disc in an optical disc reproducing/recording apparatus, comprising following steps: moving an optical pickup head to a first position of an optical disc; rotating the optical disc to a predetermined rotating speed; transferring a focus error signal produced by the optical pickup head to a focus control voltage signal; controlling the optical pickup head by the focus control voltage signal to maintain a focus light spot produced by the optical pickup head on the optical disc; and distinguishing if the optical disc is an unbalanced disc according to the focus control voltage signal.04-29-2010
20100061004Compensation for Different Transducer Translation Path Geometries - Method and apparatus for compensating for differences in translation path geometries of transducers used to access a data storage medium. A compensation profile is generated in relation to radial error between a first translation path geometry of a first transducer and a different, second translation path geometry of a second transducer. A control circuit directs the first transducer to write data to a rotatable data storage medium in relation to the compensation profile to emulate the second translation path geometry. In some embodiments, the control circuit comprises a data signal clock generator, a motor rotation clock generator, and a transducer radial translation clock generator. A nearest pulse detector identifies a closest clock signal pulse to a once-per-revolution (OPR) rotational reference, and the control circuit adjusts a frequency of the associated clock signal coincident with said closest pulse.03-11-2010
20100061002MAGNETIC HEAD INSPECTION METHOD, MAGNETIC HEAD INSPECTION DEVICE, AND MAGNETIC HEAD MANUFACTURING METHOD - A magnetic head inspection device inspects the write track width of a thin film magnetic head in a phase as early as possible during the manufacturing process. A recording signal (excitation signal) is input from bonding pads to the thin film magnetic head in a rowbar, and the magnetic field generated by the write pole (element) included in the thin film magnetic head is observed directly by using a magnetic force microscope (MFM), a scanning Hall probe microscope (SHPM), or a scanning magneto resistance effect microscope (SMRM) that performs a scanning motion at a position equivalent to the flying height of the magnetic head. In this manner, a shape of the generated magnetic field instead of the physical shape of the write pole (element) is measured; thus, a non-destructive inspection can be performed on the effective magnetic track width.03-11-2010
20080239536METHOD AND APPARATUS FOR DETECTING DEFECTS OF SERVO DATA IN A DISK DRIVE - According to one embodiment, in a disk drive having a disk medium that has a plurality of sectors, in each of which servo data containing a servo-burst patterns is recorded, a CPU calculates the reliability value of a sector to be evaluated, from a ratio of the sum of the servo-burst values acquired from the sector, to a value obtained by performing low-pass filtering operation on the sum acquired at the time of detection or acquired for the immediately preceding sample. The CPU then determines whether the sector is a defective sector having defective servo-burst patterns, on the basis of the reliability value thus calculated.10-02-2008
20080239537DISK RECORDER MANAGEMENT APPARATUS AND DISK RECORDER MANAGEMENT METHOD - According to one embodiment, a disk recorder management apparatus includes: a connection part to which a disk recorder is connected; an initial connection judging unit judging whether or not the disk recorder is connected to the connection part for the first time; and a recording control unit making the disk recorder record registration information indicating a correspondence between the disk recorder management apparatus and the disk recorder when it is judged by the initial connection judging unit that the disk recorder is connected for the first time.10-02-2008
20080239539METHOD AND APPARATUS FOR THREE-DIMENSIONAL MEASUREMENTS - An apparatus and method for measuring the physical quantities of a data center during operation and method for servicing large-scale computing systems is disclosed. The apparatus includes a cart that supports a plurality of sensors. The cart is moveable within the data center. The sensors capture temperature or other physical parameters within the room. The sensor readings, along with position and orientation information pertaining to the cart are transmitted to a computer system where the data is analyzed to select the optimum temperature or other system environmental parameters for the data center.10-02-2008
20080239535CERTIFYING WHILE SERVOWRITING MEDIA - Certifying a media while servowriting the media by formatting a full compliment of servo data in storage tracks of the media in a minimum number of passes per storage track while simultaneously performing a 100% media certification of the storage tracks during the minimum number of passes per storage track.10-02-2008
20090002861MAGNETIC HEAD TEST METHOD AND MAGNETIC HEAD TESTER - A magnetic head assembly having a mounting base in which a mounting hole having a protruded peripheral edge is formed is easily mounted on a head clamp table positioning the magnetic head assembly by fitting the mounting hole on a boss pin or a receiving hole of a tray, with a pin or a hole on a mounting table and with a positioning pin on a head clamp table and positioning a suction collet with using a boss pin or a receiving hole of a tray as references, and sucking the mounting base of the magnetic head assembly by a handling robot without requiring high positioning accuracy.01-01-2009
20110141602Systems and Methods for Storing Data to Magnetic Tape Having Damaged Areas - A method for using magnetic tape having damaged areas is disclosed. The method may include writing data to streaming magnetic tape, determining if the data write was successful, and responding to an unsuccessful data write by interrupting the data writing and advancing the magnetic tape forward a predetermined distance. Additionally, the method may include attempting to write data at the next location on the magnetic tape and determining if the data write was successful. The method may further include repeating the steps of advancing the tape, attempting to write, and determining whether the data write was successful following any determination that an attempted data write was not successful. The method may include further include resuming writing data to streaming magnetic tape at a location where a data write is determined to be successful.06-16-2011
20100053791STORAGE DEVICE, RECORDING MEDIUM EVALUATION DEVICE, AND RECORDING MEDIUM EVALUATION METHOD - According to one embodiment, a storage device that reads data from and writes data to a recording medium, which is rotationally driven by a motor, by a head, includes a ground disconnector, a motor voltage application module, and a Coulomb force detector. The ground disconnector disconnects a connection between the motor and ground. The motor voltage application module applies voltage to be supplied to the motor. The Coulomb force detector detects read output while the motor voltage application module applies voltage to the motor. The Coulomb force detector then calculates, based on the read output, an amount of change in floating height of the head to read data from or write data to the recording medium to detect the magnitude of Coulomb force generated by electrical charging of the recording medium based on the applied voltage and the amount of change in floating height of the head.03-04-2010
20080231983MAGNETIC HEAD SLIDER TESTING APPARATUS AND MAGNETIC HEAD SLIDER TESTING METHOD - In the present invention, a step portion for mounting a row bar is provided at a table stepping down from the face of the table, and by lowering a pair of hooks acrossing over the step portion in its width direction, a row bar held by the hooks is mounted on the step portion. Further, while interposing the row bar mounted on the step portion between a pair of hooks and a side face of the step portion, the side in longitudinal direction of the row bar and the bottom face thereof are butted to the bottom face and the standing up side face of the step portion to position two axes of the row bar among XYZ directions, successively, positioning of the row bar in one remaining direction along longitudinal direction of the row bar mounted on the step portion is performed by moving the table in the one remaining axial direction.09-25-2008
20100271725APPARATUS AND METHOD FOR PREVENTING QUEUE OVERFLOW FOR HARD DISK DRIVE PROTECTION IN COMPUTER SYSTEM - A queue overflow prevention method and apparatus for Hard Disk Drive (HDD) protection in a computer system is provided. The queue overflow prevention method includes measuring acceleration information of the system, determining if the system is in a stable status or an unstable status using the acceleration information, and, while the system is in the unstable status, restricting the generation of a disk Input/Output (I/O) request.10-28-2010
20100271726MAGNETIC RECORDING APPARATUS, MAGNETIC RECORDING MEDIUM, AND METHOD OF TESTING MAGNETIC RECORDING APPARATUS - According to one embodiment, a magnetic recording apparatus includes a magnetic recording medium including magnetically recordable recording tracks with a width L10-28-2010
20080278836Testing Data Transfer Time of Disk Drives in Consumer Electronics Devices - Systems, apparatus and methods are disclosed for testing performance of a disk drive in a digital home communications terminal. One such method comprises: downloading a disk drive performance test application from a server over a communication channel; executing the test application to measure at least one time for data transfer of a group of sectors on the disk drive; and reporting the time to the server over the communication channel. A digital video recorder comprises: a disk drive; a communication interface; memory storing executable instructions thereon; and a processor configured by the executable instructions. The processor is configured to download a disk drive performance test application from a server over the communication interface; execute the test application to measure at least one time for data transfer of a group of sectors on the disk drive; and report the time to the server over the communication interface.11-13-2008
20080278835MONITORING TRANSDUCER POTENTIAL TO DETECT AN OPERATING CONDITION - The disclosure is related to detecting a fault condition of a transducer for reading and writing data to a data storage medium. The fault condition can be detected based on a potential difference between a reference voltage and a common mode of the transducer.11-13-2008
20120287526BREAKDOWN PREDICTION DEVICE, BREAKDOWN PREDICTION METHOD, AND BREAKDOWN PREDICTION PROGRAM - A breakdown prediction device of the present invention includes: a vibration measurement unit that measures vibrations generated from a device being monitored; and a signal processing unit that performs breakdown prediction when a specific vibration is measured at the vibration measurement unit, a maximum vibration amplitude value of the vibration exceeding an upper limit vibration amplitude threshold, and a vibration amplitude value thereof being below a lower limit vibration amplitude threshold at a point in time when a specified time is reached from a point in time when the vibration exceeds the upper limit vibration amplitude threshold.11-15-2012
20100321810DISK DRIVE CONFIGURED TO CALCULATE HEAD REBOUND DISTANCE - According to one embodiment, a search module searches for a timing when a moving direction of a head changes in order to detect a first timing when the head collides against a stopper of a ramp during a head unload operation and a second timing when the head rebounds as a result of the collision. A calculation module calculates a rebound distance that the head has rebounded based on the first timing and the second timing.12-23-2010
20100321811DRIVE LIFE CYCLE MANAGEMENT - Described are a method and apparatus that monitor tape drive health for tape drives in a tape library. The tape library generally contains a data base that is adapted to maintain functional status records for interactions that occur when a tape drive physically engages a tape cartridge. More specifically, errors associated with tape drive and tape cartridge interactions can be stored in the data base and monitored to make determinations relative to problems encountered by a specific tape drive.12-23-2010
20090002860STORAGE APPARATUS AND CONTROL APPARATUS THEREOF, AND HEAD VIBRATION MEASUREMENT METHOD - A storage apparatus capable of measuring the vibration of a head vibration having a high frequency includes: a gate generation section that generates a plurality of first gate signals indicating the timing at which the head reads out servo information having a waveform for measurement of a reproduction signal level from a storage medium on which the servo information is written at predetermined intervals and on a first track of which a first waveform serving as a waveform for measurement of a reproduction signal level is written and which is at least a predetermined track and a second gate signal indicating at least one timing between the first gate signals; and a measurement section that measures the reproduction signal level of the waveform for measurement reproduced by the head at the timing of the gate signals.01-01-2009
20110007413CONTROL METHOD AND APPARATUS FOR A DUAL-CHANNEL WEIGHTED LPOS COMBINING SCHEME - A method for monitoring a plurality of servo channels, providing a finite state machine (“FSM”) comprising a single servo channel mode and a combined servo channel mode, and moving a sequential information storage medium comprising a plurality of servo bands across a read/write head comprising a corresponding plurality of servo sensors. The method further asserts an acquisition flag by a servo channel if that servo channel is tracking a servo pattern, and asserts a bit flag by a servo channel if a new LPOS bit is decoded. If at least one acquisition flag is asserted, the method determines if a bit flag is asserted by a servo channel associated with said asserted acquisition flag, and if an acquisition flag and a bit flag are asserted by a servo channel, the method determines a relative positioning of each servo sensor with respect to an associated servo pattern.01-13-2011
20090190244APPARATUS, SYSTEM, AND METHOD FOR DYNAMIC TAPE STICK AND TAPE BREAK DETECTION - An apparatus, system, and method are disclosed for dynamic tape stick and tape break detection. A first counter increments a first count and resets a second count in response to a sensor pulse from a first sensor of a first tape servo. A second counter increments the second count and resets the first count in response to a sensor pulse from a second sensor of a second tape servo. A detection module detects either the first count or the second count exceeding an error threshold.07-30-2009
20100271724Systems and Methods for Nyquist Tone Harmonic Measurements - Various embodiments of the present invention provide systems and methods for determining changes in fly-height. For example, various embodiments of the present invention provide storage devices that include a storage medium, an offset frequency, a read/write head assembly, and a harmonic fly-height change detection circuit. The storage medium includes a periodic data pattern that repeats at a data frequency. The read/write head assembly disposed in relation to the storage medium such that it senses the periodic data pattern and provides a sensed periodic data pattern. The harmonic fly-height change detection circuit samples the sensed periodic data pattern at an aggregate frequency to yield a first set of samples and a second set of samples. The aggregate frequency is the data frequency adjusted by the offset frequency. The harmonic fly-height change detection circuit calculates a first magnitude of the first set of samples and a second magnitude of the second set of samples.10-28-2010
20090303628DATA MANAGING METHOD, INFORMATION STORAGE APPARATUS, AND DATA MANGEMENT CIRCUIT - A magnetic disk device regularly monitors an abnormality in heads and, when detecting an abnormality in any head, transfers data in each cell corresponding to the head where the abnormality is detected to a replacement cell corresponding to another head. Then, in a management table, the magnetic disk device updates the logical address of the transfer-destination cell to the logical address of the transfer-source cell. Thereafter, the magnetic disk device deletes the data in the transfer-destination cell from the management table.12-10-2009
20090161244Method and apparatus for inspecting defects of patterns formed on a hard disk medium - If an inspection method for inspecting a patterned medium is intended for the nanoimprint process control, it is necessary to measure a correct shape of each pattern element. On the other hand, if the inspection method is intended for the quality control of products, it is necessary to inspect the products on a 100 percent basis. However, the conventional method which uses SEM or AFM could not satisfy these requirements.06-25-2009
20090161242MAGNETIC DISK SUBSTRATE AND MAGNETIC RECORDING MEDIUM THEREOF - The present invention relates to a magnetic disk substrate, in which an amplitude Wa of a waviness on a surface measured by using an interferometer for a versatile disk at a measuring wave-length of 5.0 mm is within the range of 0.1 nm to 0.5 nm, an average amplitude Wb of a microwaviness generated on the waviness measured by using a microscopy for three-dimensional surface-structural analysis at a measuring wave-length of 30 μm to 200 μm is 0.3 nm or less, and a value calculated by dividing the average amplitude Wb of the microwaviness by the amplitude Wa of the waviness is 0.6 or more.06-25-2009
20090161243Monitoring Disk Drives To Predict Failure - Embodiments include methods, apparatus, and systems for monitoring disk drives to predict failure. One embodiment includes a disk drive having a plurality of different types of sensors that sense events over a lifetime of the disk drive. Data from the events is aggregated to predict when the disk drive will fail.06-25-2009
20090027796INFORMATION RECORDING DEVICE AND CONTROL METHOD THEREFOR - According to one embodiment, an information recording device comprises, when writing asynchronous data not recorded in a disk-like recording medium among data recorded in a non-volatile memory by a control module, a setting module is configured to place priority order of writing the asynchronous data to the disk-like recording medium in response to a state of each recording area with the asynchronous data of the non-volatile memory recorded therein.01-29-2009
20090128941Write Head Tester Using Inductance - A write head is tested by measuring the effect that magnetic fields have on the inductance of the write head. For example, a perpendicular write head may be placed in a magnetic field with a first angle, e.g., non-parallel and non-perpendicular, to the air bearing surface and the inductance is measured. After altering the angle of the magnetic field the inductance is again tested. In another embodiment, the angles may be parallel and perpendicular to the air bearing surface. The difference in the inductance value can be used to determine a characteristic of the write head, such as the presence of a recording pole. In some embodiments, the inductance may be measured while applying a bias current to the write head while the write head is in an external magnetic field.05-21-2009
20090290246Method for testing performance of a magnetic head slider - A method for testing performance of a magnetic head slider includes the steps of: (1) rotating the disk and positioning the slider over the rotating disk at an initial fly-height; (2) exciting the fly-height actuator to make the slider touch the disk and recording a touch down spacing of the read head of the slider; (3) backing off the slider at a predetermined backoff amount from the disk; (4) testing dynamic performance of the slider to obtain a reference value which is related to the spacing between the disk and the slider; (5) varying the initial fly-height of the slider; (6) repeating the steps (2) to (4) with the backoff amount fixed; and (7) calculating a dynamic fly-height gamma ratio based at least in part on the recorded touch down spacing and the obtained reference values.11-26-2009
20090141385MEMORY DEVICE FOR STORING DATA AND READING DATA - According to an aspect of an embodiment, a memory device has a medium including a plurality of tracks, each of which has a plurality of sectors separated by a plurality of servo areas, for storing data in the sectors of the tracks, a head for writing data into and reading data from the medium and a controller for determining whether the head has read out data from a sector on a target track correctly or not in reference to information obtained from servo areas sandwiching the sector and for driving the head so as to retry reading out data from the sector when the controller determines that the head failed to have read out data on the target track.06-04-2009
20080316630USING INDUCTANCE TO MEASURE WRITER SPACING IN PERPENDICULAR MAGNETIC RECORDING - A magnetic data recording system that can directly measure soft underlayer spacing of a perpendicular magnetic write head during operation. The soft underlayer spacing of the magnetic write head can be determined by measuring the magnetic inductance of the write head. The inductance of the write head varies with changes in the distance between the write pole and the soft underlayer of the magnetic medium. By connecting the write head with magnetic inductance measuring circuitry, the soft underlayer spacing can be constantly monitored during operation of the magnetic data recording system. The system can also include active fly height control such as a thermal fly height control capability. By directly measuring the soft underlayer spacing in real time during use of the data recording system, the actively fly height controlling features can be operated efficiently to precisely maintain a desired spacing between the write pole and the soft underlayer of the magnetic medium.12-25-2008
20090086355SPINDLE STAGE FOR TESTING MAGNETIC HEAD WITH VCM MECHANISM AND AUTOMATIC MAGNETIC HEAD MOUNTING/DEMOUNTING DEVICE - To provide a spindle stage for testing a magnetic head in which high precision servo following can be performed by an inexpensive VCM mechanism without using a piezoelectric element, and to provide a device for mounting/demounting a magnetic head automatically. In a spindle stage for testing a magnetic head which includes: a head arm device having a head arm portion which is driven to swing by a VCM mechanism; and an HGA attached to the head arm portion, and loads the head arm device and the HGA relative to a surface of a medium in rotation to measure the electrical and mechanical characteristics, wherein the spindle stage includes: a fitting portion in which a swaging boss of the HGA is removably fitted; and a clamping member which moves between a locking position in which the swaging boss fitted in the fitting portion is locked and a releasing position in which the swaging boss can be freely fitted and removed into and from the fitting portion.04-02-2009
20110141601PROXIMITY DETECTION METHOD FOR MAGNETIC HEAD AND RECORDING MEDIUM - Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.06-16-2011
20090141384Inspection method for perpendicular magnetic recording medium and inspection device thereof - A device inspects the performance of a perpendicular magnetic recording medium by separating the medium noise component of a perpendicular magnetic recording medium to decrease the error rate by accurately separating and detecting the medium noise component. Using correlation matrices, jitter noise and T50 noise which depend on the transition point of magnetization, and DC noise which is added to a DC component are separated and detected from the medium noise component of a perpendicular magnetic recording medium acquired from the reproducing waveform of a magnetic head. By adding a base matrix of the DC noise component to a linear separation expression for detecting the noise power from the medium noise component, the DC noise is detected using the least square method, separately from the other medium noise, which depends on the fluctuation of magnetization transition points.06-04-2009
20110222182DISK DEVICE AND WRITE METHOD - A disk device and a write method that includes performing a write operation on a first data sector using first servo information, performing the write operation on a second data sector, and determining whether the write operation has been normally performed on the second data sector using a second servo signal.09-15-2011
20090244755METHOD FOR MEASURING WRITE WIDTH AND/OR READ WIDTH OF A COMPOSITE MAGNETIC HEAD AND A MEASURING DEVICE USING THE METHOD - A method for measuring a write width and/or a read width of a composite magnetic head in which a read characteristics profile having a peak as a read voltage characteristics for a moving distance is obtained by writing a test data in a designated track of eccentric tracks of such as a DTM by the composite magnetic head (write head), reading the test data from the designated track by moving the composite magnetic head (read head) in a radial direction and crossing the designated track and a write sensitive width or a read sensitive width is calculated on the basis of the read characteristics profile.10-01-2009
20090244753MONITORING ELEMENT FOR A MAGNETIC RECORDING HEAD AND METHOD OF MANUFACTURING A MAGNETIC RECORDING HEAD - A monitoring element for a magnetic recording head makes it possible to know the form of a magnetic pole of the magnetic recording head without destroying the element. The monitoring element for a magnetic recording head is formed on a workpiece for magnetic recording heads on which element magnetic poles of the magnetic recording heads are formed. The monitoring element includes a monitoring magnetic pole formed of a same material and in a same form as the element magnetic poles and monitoring terminals that are electrically connected to the monitoring magnetic pole.10-01-2009
20090244756DATA STORAGE APPARATUS - A data storage apparatus includes: a medium for storing data having synchronization marks and data blocks, the synchronization mark and the data block being allocated alternately in the circumference direction of the medium; a head writing data into or reading out data from the medium; and a processor for executing a process including: reading out synchronization marks, measuring time for the head to pass through each of the data blocks based on signals read out from each of the synchronization marks in the circumference direction, generating write/read clock for each of the data blocks, which is continuously changing in speed, by calculating difference in time for the head to pass through the each one of the data blocks and its adjacent one of the blocks on the basis of the time measured, and writing data into or reading out data from the medium in synchronization with the write/read clock.10-01-2009
20090244751TRACK ERROR MEASUREMENT AND RECOVERY - A method of measuring a track value is shown. The track value is related to track mis-registration, and is compared to a track value limit to assess a condition of the track. In example embodiments, the track value is determined as a function of multiple position error signals from previous wedges in the track. During a self servo writing operation, the track value and the track value limit are used to selectively perform a recovery action. In example embodiments, the track value limit is dynamically adjusted.10-01-2009
20100014179Media library system and method for monitoring changes in inventory of media cartridges - A method for monitoring changes in an inventory of media cartridges in a media library includes the steps of determining with a controller that the inventory of media cartridges in the media library has changed, and asynchronously reporting with the controller the specific change in inventory of media cartridges that has occurred in the media library. The method can also include the step of determining whether the change in inventory included an increase or a decrease in the quantity of media cartridges within the media library, or whether the change in inventory did not include an increase or decrease in the quantity of media cartridges within the media library. Further, the method can also include the step of determining whether the change in inventory of media cartridges is required to be reported. A media library system includes a media library having a plurality of media cartridges, and a controller that determines a change in an inventory of media cartridges in the media library. In certain embodiments, the controller asynchronously and selectively reports a specific change in the inventory of media cartridges in the media library.01-21-2010
20090316288METHOD FOR TESTING MAGNETIC RECORDING MEDIUM AND METHOD FOR PRODUCING MAGNETIC RECORDING MEDIUM - Provided is a method for testing a magnetic recording medium which is capable of carrying out a certification test with a high degree of accuracy.12-24-2009
20090251815Testing system and testing method for inspecting electonic devices - A testing system for inspecting electronic devices includes a first transparent disk, a first image capturing unit disposed under the first transparent disk, a second disk disposed next to the first transparent disk, a guiding unit disposed on adjacent area between the transparent disk and the second disk, and a plurality of second image capturing units disposed around the second disk. A plurality of electronic devices is continuingly supplied onto the first transparent disk and the first image capturing unit is used for capturing the images of the bottom surfaces of the electronic devices. Then, the electronic devices are guided to the second disk via the guiding unit and the second image capturing units are used for capturing the images of other surfaces of the electronic devices. A testing method for electronic devices is further disclosed.10-08-2009
20100149674METHOD OF MANUFACTURING DISK DEVICE, METHOD OF WRITING SERVO INFORMATION TO STORAGE DISK, AND DISK DEVICE - According to one embodiment, a method of writing servo information comprises: moving a head at a predetermined pitch in the radial direction of a storage disk to write servo information to each radial direction position in the circumferential direction of the storage disk; detecting a positional deviation value of the head while the servo information is being written to the radial direction position and determining whether the positional deviation value exceeds a predetermined value; and writing, when the positional deviation value exceeds the predetermined value, the position of defective servo information where the positional deviation value exceeds the predetermined value to a predetermined position in the radial direction of the storage disk.06-17-2010
20100149673METHOD FOR TESTNG MOLD STRUCTURE, MOLD STRUCTURE, AND MAGNETIC RECORDING MEDIUM - A method for testing a mold structure including magnetically transferring a magnetic signal according to a concavo-convex pattern for a servo area in a mold structure to a perpendicular magnetic recording medium; electrically reproducing ≧50 tracks of the magnetic signal of servo data transferred onto the perpendicular magnetic recording medium using a magnetic head to obtain a reproduction signal; and calculating a pattern drawing accuracy radially from the reproduction signal to evaluate a performance of the mold structure including a disc-shaped base material; and the concavo-convex pattern for the servo area and a concavo-convex pattern for a data area formed on a base material surface following a desired design pattern. The concavo-convex patterns for the servo area are aligned in the radial direction of the base material, and the concavo-convex pattern for the data area are aligned in the circumferential direction between the concavo-convex patterns for the servo area.06-17-2010
20120194936EVALUATION METHOD OF PERPENDICULAR MAGNETIC RECORDING MEDIUM AND MANUFACTURING METHOD OF PERPENDICULAR MAGNETIC RECORDING MEDIUM - A characteristic evaluation method of a perpendicular magnetic recording medium suitable for obtaining a perpendicular magnetic recording medium which can respond to much higher recording density is provided.08-02-2012
20100177418WRITER AND READER CENTER ALIGNMENT WITH SERVO AND DATA TRACK IN DISCRETE TRACK RECORDING - A hard disk drive with a patterned disk that has a discrete track. The disk drive includes a controller that controls a head and a voice coil motor to optimize a writing of information onto the discrete track. Writing optimization can occur by initially writing a track of information and recording the write position. The written track is then located by reading the information with a read element of a drive head and analyzing a quality of the read signal, such as signal amplitude or error rate. The read position is then recorded. The information is erased and the head is moved. The process of writing, finding the written track location, storing the write and read positions and again moving the head is repeated. The write and read positions that provide the best quality signal is saved and subsequently used to write and read data on the discrete track.07-15-2010
20090251816Patterned medium inspection method and inspection device - A defect inspection method and device for a perpendicular magnetic recording medium that has discrete recording tracks and grooves between recording tracks, including DC demagnetizing the perpendicular magnetic recording medium, detecting a reproduced signal from the perpendicular magnetic recording medium after the DC demagnetizing, removing output fluctuation components caused by the grooves from the reproduced signal using a filter with a prescribed cutoff frequency and separating a peak output of the reproduced signal, comparing the peak output with a prescribed reference signal, and identifying a location where the peak output exceeds the reference signal as a defect location. The method further includes performing an envelope-detection on the reproduced signal, detecting a pre-format region in the perpendicular magnetic recording medium using the envelope-detection result, masking the detected pre-format region, and detecting the defect location in a region outside the masked pre-format region in the perpendicular magnetic recording medium.10-08-2009
20100157455TEST DEVICE FOR MAGNETIC STORAGE DEVICE, MAGNETIC STORAGE DEVICE, AND METHOD OF MANUFACTURING MAGNETIC STORAGE DEVICE - According to one embodiment, a test device for a storage device includes: a module configured to acquire from the storage device a value corresponding to a signal level read from a magnetic disk through a magnetic head of the storage device, at a first timing at which an initial power of 0 or greater is supplied to a heater in the head and at a second timing at which a power to the heater is returned to the initial power after the power to the heater has been increased from the initial power, a periphery of a head element in the head has been expanded by the heater, and the element has been protruded toward a magnetic disk side; and a determiner configured to determine whether plastic deformation has occurred in the periphery of the element based on a difference between the values obtained at the first and second timings.06-24-2010
20100002327METHOD FOR IMPROVING MAGNETIC READ SENSOR MANUFACTURING USING EXTERNAL AND/OR EMBEDDED HEATING ELEMENT - A method for testing a magnetic head to determine whether the magnetic head is unacceptably affected by temperature variations. The test includes testing the magnetic head at different temperatures and measuring either or both of a signal amplitude and a signal asymmetry of a signal from the magnetic head at the different temperatures. If signal amplitude or signal asymmetry vary excessively as a result of the temperature change then the head can be scrapped.01-07-2010
20100157456DISK DRIVE AND METHOD OF MEASURING FRICTIONAL CHARACTERISTICS - According to one embodiment, in a disk drive, a voice coil motor is controlled to cause a head to minutely vibrate in a radial direction on a track of a disk. When the voice coil motor vibrates the head in the radial direction of the disk, frictional force occurring between the disk and the head is calculated based on the driving force of the voice coil motor generated to vibrate and detected positional information, thereby measuring frictional characteristics.06-24-2010
20100188767DISK DRIVE AND WRITE CONTROL METHOD THEREIN - According to one embodiment, a disk drive includes a medium scanner and a threshold manager. The medium scanner measures the write count of each head with respect to a disk. The medium scanner executes a read verify process by which data is read out from the disk, during idle state, when the write count is equal to or larger than a predetermined threshold value. The medium scanner rewrites the recovered data to the disk, if a read error occurs and the error is recoverable. The threshold manager initially sets the write count threshold value of each head in accordance with the head performance, and dynamically changes the write count threshold value in accordance with the error rate when the device is in operation.07-29-2010
20100002328DISK DRIVE IN WHICH THE DYNAMIC FLYING HEIGHT OF HEAD IS ADJUSTED - According to one embodiment, an adjusting element adjusts a dynamic flying height of a head lying over a disk in accordance with the power supplied to it. A calculation module calculates the power to supply to the adjusting element, from a barometric pressure detected by a barometric pressure sensor. A failure detection module detects failure of the barometric pressure sensor. An unload controller predicts an abnormal dynamic flying height of the head from the failure detected and then instructs the unloading of the head away from the disk.01-07-2010
20100002326Method and system for perpendicular magnetic media metrology - A metrology system for measuring the magnetic properties of a magnetic recording medium layer on a device used for perpendicular recording.01-07-2010
20100265609DISK DRIVE TRANSPORT, CLAMPING AND TESTING - A disk drive transporter, for transporting a disk drive and for mounting a disk drive within a test slot, includes a frame configured to receive and support a disk drive. The frame includes sidewalls configured to receive a disk drive therebetween and sized to be inserted into a test slot along with a disk drive. The frame also includes a clamping mechanism operatively associated with at least one of the sidewalls. The clamping mechanism includes a first engagement element and a first actuator operable to initiate movements of the first engagement element. The first actuator is operable to move the first engagement element into engagement with a test slot after a disk drive being supported by the frame is arranged in a test position in a test slot.10-21-2010
20100226032CONTROL DEVICE, MAGNETIC DISK DEVICE, AND IW SENSITIVITY CALCULATING METHOD - According to one embodiment, a control device includes a writer, a setting module, a reader, and an Iw sensitivity acquiring module. The writer writes a signal by the magnetic head. The setting module sets an electric parameter to the magnetic head. The reader reads the signal by the magnetic head. The Iw sensitivity acquiring module acquires Iw sensitivity of the magnetic head. The Iw sensitivity acquiring module includes a first acquiring module, a second acquiring module, and an Iw sensitivity calculator. The first acquiring module acquires a predetermined output value related to control of a signal having a predetermined frequency. The second acquiring module acquires a predetermined output value related to control of the signal having the predetermined frequency. The Iw sensitivity calculator calculates the Iw sensitivity of the magnetic head based on the predetermined output values acquired by the first and second acquiring modules.09-09-2010
20100238577METHOD AND APPARATUS FOR MEASURING PHASE SHIFT IN A DISK DRIVE HAVING BIT-PATTERNED MEDIA - According to one embodiment, a disk drive comprising a magnetic disk of bit-patterned type is provided. The disk drive has a reproduction module, a measurement module, and a recording module. The reproduction module outputs a reproduced signal corresponding to the phase-shift measuring bits provided on the magnetic disk. The measurement module determines that the phase shift corresponding to the phase-shift measuring bits is the phase shift of a write clock signal if the reproduced signal is determined to be indefinite on the basis of the quantization value of the reproduced signal. The recording module records data corresponding to the data recording bits, by using the write clock signal adjusted by the phase shift.09-23-2010
20120194935SYSTEM AND METHOD FOR MANAGING ERRORS ON A MAGNETIC TAPE - Systems and methods for managing errors on a magnetic tape having a plurality of partitions accessed by a tape drive having an associated tape drive processor in communication with a host computer having an associated host processor include receiving mapping information from the host computer that designates at least first and second logically adjacent partitions for reading/writing consecutive data, receiving a read/write request to transfer the consecutive data for the first and second partitions, detecting a data error when attempting to read/write the data for the second partition and communicating a corresponding data error message to the host computer, and receiving modified mapping information from the host computer that designates a third partition as logically adjacent to the first partition for reading/writing the consecutive data.08-02-2012
20100226031Systems and Methods for Defective Media Region Identification - Various embodiments of the present invention provide systems and methods for storage medium flaw detection. For example, some embodiments provide flaw detection systems that include an input circuit, a data processing circuit and a defect detection circuit. The input circuit is operable to receive an input signal and to provide a filtered output. The data processing circuit is operable to receive the filtered output and to compute a difference between the filtered output and an expected output, and the defect detection circuit receives the difference between the filtered output and the expected output and compares a derivative of the difference with a threshold value, and asserts a defect signal when a magnitude of the derivative of the difference exceeds a threshold value.09-09-2010
20100238576MAGNETIC BIT-PATTERNED DISK AND DISK DRIVE - According to one embodiment, a disk drive having a magnetic disk of the bit pattern media type is provided. The disk drive has a reproduction module configured to reproduce a signal from a measurement area provided on the magnetic disk and holding groups of phase-shift measuring bits, a measurement module configured to measure a phase shift that a write clock signal has with respect to data recording bits held in a data record area provided on the magnetic disk, when the signal reproduced by the reproduction module is indefinite, and a recording module configured to record data that corresponds to the data recording bits, by using the write clock signal adjusted by the phase shift.09-23-2010
20100246044MAGNETIC HEAD-POSITIONING SYSTEM, MAGNETIC HEAD TEST SYSTEM AND MAGNETIC DISK TEST SYSTEM - A magnetic head-positioning system to accurately test a magnetic disk and a magnetic head, comprises a plurality of hinges attached on an end portion of a linear driving element and disposed on both sides of a center line of the linear driving element, which is in parallel with an extension-shrinkage direction of the linear driving element, and an arm having a length longer than a distance between a plurality of hinge joint portions, the plurality of the hinge joint portions each of which join the hinge with a root portion of the arm and which are disposed on both sides of a center line of the arm which is in parallel with a longitudinal direction of the arm. The arm has an extremity portion on which a head gimval assembly is detachably attached and this head gimval assembly is positioned.09-30-2010
20110058270Rework method and apparatus of magnetic record medium, information - A reproducing method of reproducing magnetic information written in each of bits of a recording medium using a magnetic head having a reading element configured to measure external magnetic field intensity includes moving, measuring and specifying steps. In the moving step, the magnetic head moves to a position where the reading element covers two bits, one bit having known magnetic information, the other bit being adjacent to the one bit and having unknown magnetic information. In the measuring step, the reading element measures magnetic field intensity coming from the recording medium. In the specifying step, magnetic information of the bit having the unknown magnetic information is specified based on the magnetic field intensity measured in the measuring step and magnetic information of the bit having the known magnetic information.03-10-2011
20100142073METHOD AND APPARATUS FOR CONTROLLING FLY-HEIGHT OF A PERPENDICULAR-MAGNETIC-RECORDING HEAD IN A HARD DISK DRIVE - A method for controlling proximity of a read element of a perpendicular-magnetic-recording (PMR) head to a PMR disk. The method includes: a) writing recorded data with a write element of the PMR head to the PMR disk; b) providing a proximity-control setting to a proximity-control element; c) positioning the read element of the PMR head with the proximity-control element as determined by the proximity-control setting in communication with the PMR disk for reading recorded data back from the PMR disk; d) measuring a resolution of a read-back signal of recorded data on the PMR disk associated with the proximity-control setting; e) determining if the resolution measured for the read-back signal of recorded data on the PMR disk satisfies a criterion for the resolution of the read-back signal of recorded data; and, f) changing the proximity-control setting, and repeating b), c), d) and e), unless the resolution satisfies the criterion.06-10-2010
20100254036ERROR COMPENSATION USING A RESERVE TRACK - In one embodiment, a method includes simultaneously writing tracks of data on a magnetic medium in a first direction using less than all available writers in an array of magnetic writers. The method also includes determining that an error has occurred when writing one of the tracks and terminating writing with the writer associated with the track on which the error occurred. In addition, the method includes simultaneously writing tracks of data on the magnetic medium in the first direction using a previously unused writer in the array of magnetic writers.10-07-2010
20100118423DETERMINATION OF THE QUALITY OF AN ERASE PROCESS FOR PERPENDICULAR MAGNETIC RECORDING DISKS - Methods and test systems are disclosed for determining the quality of an erase process for perpendicular magnetic recording (PMR) disks. After performing an erase process on a PMR disk and before the PMR disk is assembled into a hard disk drive, a first test pattern of magnetization pulses is written to a region of the PMR disk. A second test pattern is subsequently read from the region of the PMR disk. The second pattern of magnetization pulses is analyzed in relation to the first test pattern and measured to determine the quality of the erase process.05-13-2010
20100142072METHODS FOR DEPOSITING LUBRICANT ONTO DISKS AND SYSTEMS THEREOF - A system in one embodiment includes a disk; a reservoir having a selectively openable cover; a lubricant in the reservoir; and a sensor for detecting an event or condition that triggers opening of the cover. A method in another embodiment includes determining that a trigger event or a trigger condition is occurring or has occurred in a hard disk drive; opening a cover of a lubricant reservoir for allowing egress of lubricant therefrom upon determining that the trigger event or the trigger condition has occurred; and closing the cover of the lubricant reservoir after a period of time. Additional systems and methods are also presented.06-10-2010
20090073594Disk drive device manufacturing method thereof, and method for specifying data track pitch for the disk drive device - Embodiments of the present invention help to increase the capacity and the reliability of a disk drive device to improve the manufacturing yield thereof. An embodiment of the present invention sets a data track pitch for each head slider (recording surface) in accordance with head characteristics. This method for specifying the data track pitch is based on the distance between erase band ends (EBEs) of the both adjacent data tracks. The erase band of a data track is a band defined as the area where the already written data are erased in writing the data track. The distance between the erase band ends of the both adjacent data tracks corresponds to the width SW of the area which is not erased by the adjacent data tracks. Specifying the data track pitch based on this leads to increase in the data capacity of each recording surface and secure prevention of occurrence of a squeeze error.03-19-2009
20090244754DATA STORAGE DEVICE AND WRITE PROCESSING METHOD FOR DATA STORAGE DEVICE - In a data storage device, a head writes data so as to protect data from off track writing to adjust tracks. A control unit acquires large ring buffer during sequential writing and performs a retry to return adjacent tracks, according to data of a return sector area of the ring buffer when a write error occurs. A write error due to a detection mistake of an off track error can be prevented.10-01-2009
20090323209METHOD FOR MEASURING MAGNETIC WRITE WIDTH IN DISCRETE TRACK RECORDING - A method of measuring a magnetic write width of a magnetic head MWW12-31-2009
20130128371DETERMINING TAPE HEAD CONDITION - Techniques to use a model associating condition of a tape head with tape head usage are described. The tape head is for use in a magnetic tape drive. In examples, a condition of the tape head is determined using a model. In examples, the model fits determined values of the condition parameter.05-23-2013
20110032631APPARATUS AND METHODS OF GENERATING A TEST PATTERN OF DATA, ANALYSING A TEST PATTERN OF DATA, AND TESTING A DATA STORAGE DISK MEDIUM AND/OR A READ/WRITE HEAD - A method of generating a test pattern of data to be written to a data storage disk medium for testing includes: rotating the disk; detecting fluctuations in the speed of rotation of the disk; producing a reference clock signal in accordance with the fluctuations so as to be synchronised with the rotation of the disk; and, generating a test pattern of data using the reference clock signal as a timing reference. An apparatus for generating a test pattern of data includes a spindle for rotating a disk; a detector arranged to detect fluctuations in the speed of rotation of the disk; a processor arranged to produce a reference clock signal in accordance with fluctuations so as to be synchronised with the rotation of the disk; and, a pattern generator arranged to generate a test pattern of data using the reference clock signal as a timing reference.02-10-2011
20090207515ERROR CORRECTION CAPABILITY FOR LONGITUDINAL POSITION DATA IN A TAPE STORAGE SYSTEM - A longitudinal position (LPOS) word L(n) is encoded with error correction capability. The LPOS word includes a plurality of LPOS symbols L08-20-2009
20100302664DISK DRIVE DATA STORAGE SYSTEMS AND METHODS USING BACKUP POWER SOURCE CHARGED BY SPINDLE MOTOR - A data storage system includes data storage including at least one data storage disk driven by a spindle motor and a control circuit coupled to the data storage and configured to be coupled to a main power source and a backup power source. The control circuit is configured to detect failure of the main power source, to responsively write data to the data storage while powered by the backup power source, and to subsequently recharge the backup power source using the spindle motor. The control circuit may be configured to further write data to the data storage using the recharged backup power source. The data storage system may further include a head configured to read and/or write data to or from the at least one data storage disk, and the control circuit may be configured to park the head using the recharged backup power source.12-02-2010
20100302667DETECTION OF DEFECTIVE TAPE DRIVE BY AGGREGATING READ ERROR STATISTICS - A plurality of tape drives writes a plurality of indicators corresponding to a plurality of data units on a tape, wherein an indicator indicates which tape drive of the plurality of tape drives has written a corresponding data unit on the tape. Each of the plurality of tape drives generates an extent of read errors, in response to reading the plurality of data units written on the tape. The extent of read errors generated by each of the plurality of tape drives are aggregated at a computational device coupled to the plurality of tape drives. A determination is made at the computational device of a defective tape drive of the plurality of tape drives from the aggregated extent of read errors.12-02-2010
20100302666DETECTING A PERIODIC SEQUENCE OF SERVO SIGNALS - A system and method are disclosed for detecting a periodic sequence. A value detector module detects a plurality of values of a periodic sequence. In one embodiment, a transformation module transforms the plurality of values into transformed values. A confinement module confines the values to a limited set of confined values. A correlation module correlates the confined values with a plurality of instances of the periodic sequence. In addition, a selection module selects an instance of the periodic sequence with the highest correlation to the confined values as an observed periodic sequence.12-02-2010
20100302665METHOD FOR MEASURING OPTIMUM SEEKING TIME AND INSPECTION APPARATUS USING THE SAME - The present invention provides a method for measuring an optimum seeking time and an inspection apparatus using this method capable of measuring and setting an optimum seeking time for inspection of a magnetic disk or magnetic head. The method samples average level differences of sector-wise read signals in positive and negative domains for one round of track and detects a minimum value H and a minimum value L among these differences. The method recalculates the seeking time while changing the settling time. After writing and reading test data, calculates a deviation DEV of average levels DEV=(H−L)/(H+L). The method is adapted to obtain a minimum one of the values of settling time having measured when the deviation DEV of average levels is equal to or less than a predetermined value as an optimum settling time or an optimum seeking time.12-02-2010
20100302663METHOD OF MEASURING NON-COHERENT RUNOUT FOR A DISK DRIVE - In a disk drive, a modified adaptive runout compensation algorithm is employed to measure non-coherent repeatable runout (RRO) of a track. The adaptive runout compensation algorithm is used to control the transducer head to follow the average RRO of adjacent tracks during the process of computing correction factors for non-coherent RRO for a given track. The adaptive runout compensation algorithm does not completely adapt to both the coherent and non-coherent RRO of a particular track because the transducer head is positioned over any one particular track for only a limited number of revolutions.12-02-2010
20100321813SYSTEM, METHOD, AND APPARATUS FOR PERFORMING METROLOGY ON PATTERNED MEDIA DISKS WITH TEST PATTERN AREAS - Techniques for performing metrology on magnetic media disk formations that are arranged in curvilinear patterns are disclosed. Small integrated test patterns having rectangular periodicity are integrated among the concentric circles of patterned media formations. The test patterns cover only very small areas of the disk so as to not significantly affect disk capacity. The periodicity of the test patterns allows their formations to be more readily measured by metrology technology than those having a curvilinear periodicity.12-23-2010
20110002060DETERIORATION DETECTION METHOD OF COMPOSITE MAGNETIC HEAD AND MAGNETIC DISK INSPECTION APPARATUS - An object of the present invention is to provide a deterioration detection method of a head and a magnetic disk inspection apparatus in which the number of times of exchanging the head due to deterioration is decreased to improve the throughput of an inspection. In the present invention, a resistance value detecting circuit that is directly coupled to both terminals of an MR head is provided to measure the resistance value of the MR head, and the measured value is compared with the initial value of the exchanged head, so that it is possible to recognize a deterioration state of each head irrespective of a magnetic disk as a measurement target.01-06-2011
20110002061CIRCUIT AND METHOD FOR DETECTING THE PHASE OF A SERVO SIGNAL - A detector recovers servo data from a servo signal generated by a read-write head, and determines the head-connection polarity from the recovered servo data. Such a detector allows a servo circuit to compensate for a reversed-connected read-write head, and thus allows a manufacturer to forego time-consuming and costly testing to determine whether the head is correctly connected to the servo circuit.01-06-2011
20110019298TESTING MAGNETIC DISK PERFORMANCE WITH A SINGLE SLIDER SIMULATING SLIDERS OF VARIOUS DISK DRIVE SYSTEMS - Magnetic disk drive systems and associated methods are described for testing magnetic disk performance for certification with a plurality of magnetic disk drive systems prior to installation. The test system may position a slider at a first spacing between the magnetic disk in the slider and simulate the recording performance of a disk drive system with the magnetic disk at the first spacing. The disk drive test system may then transfer a control signal to a heating element in the slider to move the slider to a different spacing between the magnetic disk and the slider to simulate the recording performance of another disk drive system. The test system may, thus, use a single slider to certify a magnetic disk with a plurality of disk drive systems.01-27-2011
20110019299LOAD/UNLOAD CONTROL METHOD AND APPARATUS FOR A MAGNETIC DISK DRIVE - According to one embodiment, an estimation method comprises measuring and creating. The measuring is configured to measure a head velocity and a terminal voltage of a coil of a voice coil motor at least two times before unload in a control system eliminating an influence caused by a transient response of inductance of the voice coil motor. The calculating is configured to a calculate torque constant and a coil resistance based on command voltages and at least two measured head velocities and terminal voltages of the coil.01-27-2011
20100172045CALIBRATION OF AN AUTOMATED DATA STORAGE LIBRARY WITH A CARTRIDGE-LIKE ELEMENT - Calibration of an automated data storage library having a plurality of storage slots configured to store at least one data storage cartridge. An element is placed in one of the plurality of storage slots having a known location, the element having similar external dimensions as a data storage cartridge having a fiducial mark thereon. The fiducial mark is sensed, and the position of the fiducial mark is calibrated with respect to the known location of the storage slot. The element comprises an exterior shell having similar external dimensions as a data storage cartridge; and the fiducial mark located on the exterior shell comprises at least one contrasting edge defining a specific calibration location on the element.07-08-2010
20110043938Systems and Methods for Fly-Height Control Using Servo Data - Various embodiments of the present invention provide systems and methods for determining changes in fly-height. For example, various embodiments of the present invention provide storage devices that include a storage medium having servo data thereon. A read/write head assembly is disposed in relation to the storage medium. A servo based fly-height adjustment circuit receives the servo data via the read/write head assembly, and calculates a first harmonics ratio based on the received data and compares the first harmonics ratio with a second harmonics ratio to determine an error in the distance between the read/write head assembly and the storage medium.02-24-2011
20110116182MAGNETIC HEAD SLIDER TESTING APPARATUS AND MAGNETIC HEAD SLIDER TESTING METHOD - A step portion for mounting a row bar is provided at a table stepping down from the face of the table, and by lowering a pair of hooks crossing over the step portion in its width direction, a row bar held by the hooks is mounted on the step portion. While interposing the row bar mounted on the step portion between a pair of hooks and a side face of the step portion, the side in longitudinal direction of the row bar and the bottom face thereof are butted to the bottom face and the standing up side face of the step portion to position two axes of the row bar among XYZ directions, successively, positioning of the row bar in one remaining direction along longitudinal direction of the row bar mounted on the step portion is performed by moving the table in the one remaining axial direction.05-19-2011
20090257142HEAD ASSEMBLY IN A DEPOPULATED CONFIGURATION - The application relates to utilizing a head assembly, having a default boot-up head and at least one other head, in a depopulated configuration. If, during testing of the head assembly, the default boot-up head is found to be flawed, it designated as faulty in a non-volatile memory in the head assembly. The head assembly with the default boot-up head is used in a data storage device.10-15-2009
20110242693MAGNETIC RECORDING MEDIUM EVALUATION APPARATUS AND EVALUATION METHOD - This invention provides a magnetic recording medium evaluation apparatus and evaluation method which yield results having good correlation with error rate measurements even when comparing media with different structures. Signals from a function generator are recorded in a magnetic recording medium. The recording signals are also passed through a first digital filter to obtain ideal restored signals. Reproduced signals from the magnetic recording medium are sampled in synchronization with the output from the function generator, and the discrete signals are passed through a second digital filter to obtain restored signals. The outputs from the first and second digital filters are input to an operational amplifier, and the difference between the restored signals and the ideal restored signals is taken for each sampling of the recording signals. The signal-to-noise ratio of the ideal restored signal to the average of the absolute value of this difference is used to evaluate signal quality.10-06-2011
20100027150MAGNETIC STORAGE APPARATUS AND METHOD FOR TESTING THEREOF - According to an aspect of the embodiment, a MCU divides a target track into recording areas on magnetic disks, assigns the recording areas to the magnetic heads, and performs write control during one rotation of the magnetic disks so that the magnetic heads write data in the recording areas assigned to the respective magnetic heads. After data writes by the magnetic heads, the MCU verifies whether data in the testing areas of the tracks adjacent to the target track is held without being erased.02-04-2010
20100039725ECCENTRICITY CORRECTION METHOD, SIGNAL PROCESSING CIRCUIT, MAGNETIC STORAGE APPARATUS AND PERPENDICULAR MAGNETIC RECORDING MEDIUM - A magnetic storage apparatus has a reproducing head to reproduce information from a perpendicular magnetic recording medium that is recorded with servo information, eccentricity correction data and read/write data. The apparatus further has a filter part to filter a reproduced output of the reproducing head by filtering the servo information which has a differentiated waveform by a non-differentiating characteristic and by filtering the eccentricity correction data and the read/write data which have rectangular waveforms by a differentiating characteristic, a demodulating part to demodulate the servo information, the eccentricity correction data and the read/write data that are filtered by the filter part, and a servo system to carry out a control process including an eccentricity control based on the servo information and the eccentricity correction data that are demodulated.02-18-2010
20090323211New data pattern for fly height measurement - A hard disk drive that includes a disk and a head that is separated from the disk by a flying height. The disk drive also includes a circuit that determines the flying height from an equation that uses a third harmonic of a read signal. The read signal includes a data pattern that is a product of a first data pattern and a second data pattern. The resultant data pattern provides a third harmonic with a relatively high magnitude and improved signal to noise ratio.12-31-2009
20100053792Apparatus for and method of measuring motion characteristics of head gimbal assembly - An apparatus correctly measures motion characteristics a head gimbal assembly exhibits when turned in a radial direction of a hard disk. The apparatus includes an assembly support to fixedly support the head gimbal assembly on a center axis that corresponds to a rotation axis around which the head gimbal assembly is turned in actual use, a disk drive to rotatably support the hard disk and turn around a turn axis that is concentric with the center axis on which the head gimbal assembly is fixedly supported, and a turn unit to turn the disk drive around the turn axis, thereby creating a relative turn of the head gimbal assembly with respect to the hard disk.03-04-2010
20100053788METHOD OF MEASURING VARIATION IN FLOATING AMOUNT AND MAGNETIC STORAGE APPARATUS - A method for measuring a variation in the floating amount of a magnetic head comprising: measuring the ambient temperature which is a temperature of the magnetic storage apparatus; reading a signal recorded in the magnetic recording medium; measuring a signal value which is a value related to a signal read in the reading; and calculating a variation in the floating amount of the magnetic head based on relationship information which is information representing a relationship between the ambient temperature and signal value that have previously been measured, measurement value which is the ambient temperature measured in the measuring of the temperature, and signal value measured in the measuring of the signal.03-04-2010
20100053790HARD DISK INSPECTION APPARATUS AND METHOD, AS WELL AS PROGRAM - A hard disk inspection apparatus comprises an image pickup device which includes an inspection region portion of a disk surface including an edge of a hard disk, and which picks up an image of reflected light from the inspection region portion, an edge detection processing device which detects an edge position of the hard disk, an information acquisition device which acquires specification information that defines several values of a inspection target hard disk, a window separation device which separates the captured image into windows, an image analysis device which performs data processing for each of the regions into which the captured image is separated by the window separation device, and acquires information regarding positions and sizes of dust for each region, and a display control device which displays a result obtained by the image analysis device on a monitor screen.03-04-2010
20100134912LUBRICANT DISTRIBUTION IN HARD DISK DRIVES USED FOR DIGITAL VIDEO RECORDERS - A method for utilizing idle times during read/write operations for a personal video recorder (PVR) is described. Idle times during read/write operations are predicted and then such idle times are used to perform hard disk maintenance functions.06-03-2010
20110075288MAGNETIC RECORDING MEDIUM - A novel magnetic recording medium is disclosed in which a plurality of magnetic data recording layers and navigation layers are separate from one another. By decoupling the navigation and data layers, data may be written to data layers without the need to align the written data along servo tracks. Thus, the data layers may be configured for high recording density. Beneficially, imperfections within the magnetic data layers may also be compensated for by the use of adaptive error correction schemes which vary the encoding/decoding of data during writing/reading based upon the local quality of the recording media.03-31-2011
20110075287System and method for map detector for symbol based error correction codes - A system for decoding data includes a symbol based error correction code device. The error correction code device includes a channel detector configured to generate probability mass function (PMF) information. The error correction code device further includes a decoder coupled to the channel detector. The decoder is configured to use the PMF information from the channel detector to perform an error correction code operation. The decoder also is configured to generate PMF information. The channel detector is configured to receive extrinsic PMF information in a turbo equalization scheme.03-31-2011
20120275048RECORDING REPRODUCING APPARATUS AND MAGNETIC RECORDING MEDIUM - A magnetic recording element records information by applying a recording magnetic field to a magnetic recording medium having an information recording area to form a plurality of recording columns extending in a first direction. Recording by the magnetic recording element is performed so that a first recording column and a second recording column formed before the first recording column partially overlap each other in a second direction perpendicular to the first direction, and that a recording start position of the first recording column is positioned upstream, relative to the recording direction, of a recording start position of the second recording column.11-01-2012
20080204913Magnetic head inspection system, magnetic head inspection method and magnetic disk drive manufacturing method - Embodiments of the present invention provide a magnetic head inspection system having a simple configuration capable of inspecting magnetic heads. According to one embodiment, the magnetic head inspection system comprises an inspection module which is provided with a magnetic disk where servo data including track identifier information are recorded, a spindle motor, a carriage having a mount structure to which a head assembly containing a magnetic head is secured, a voice coil motor and a main circuit section. An inspection circuit section instructs the main circuit section to execute control so as to move the magnetic head to a specific track and perform a certain read write operation by the magnetic head in order to inspect the magnetic head.08-28-2008
20100284102MAGNETIC RECORDING DEVICE WITH AN INTEGRATED MICROELECTRONIC DEVICE - A system includes a magnetic recording device and a circuit including at least one active semiconductor component. The circuit is formed on the magnetic recording device and generates an output associated with operation of the magnetic recording device.11-11-2010
20120134043Systems and Methods for Spiral Waveform Detection - Various embodiments of the present invention provide systems and methods for determining a location of a spiral pattern. As an example, a location detection circuits is discussed that includes: a pattern detection circuit, a computation circuit, and a center determination circuit. The pattern detection circuit is operable to identify a subset of a series of data samples corresponding to a defined pattern, and to indicate a location of the identified subset of the series of data samples. The series of data samples corresponds to a spiral pattern. The computation circuit operable to sum an absolute value of each sample of the subset of the series of data samples to yield a sum. The center determination circuit operable to identify a location of the spiral pattern using the sum.05-31-2012
20110134559METHODS FOR PRODUCING AND/OR TESTING MAGNETIC HEADS USING CLASSIFICATIONS - In one embodiment, a manufacturing method for magnetic heads includes classifying magnetic heads into one of a first tested head class, and a non-test-candidate head class, determining characteristic values of the magnetic heads classified in the first tested head class, estimating characteristic values of the magnetic heads classified in the non-test-candidate head class, wherein the estimating is based on the characteristic values of the magnetic heads classified in the first tested head class, classifying each of the magnetic heads classified in the non-test-candidate head class into one of: a second tested head class, and a non-test head class based on the estimated characteristic values, determining characteristic values of the magnetic heads classified in the second tested head class, and screening magnetic heads in the second tested head class based on the determined characteristic values of the magnetic heads classified in the second tested head class.06-09-2011
20110134557REAL TIME MONITORING INCONSISTENT OPERATIONS IN A HARD DISK DRIVE - Real time monitoring inconsistent operations in a hard disk drive, wherein the hard disk drive comprises a magnetic disk, a controller and a channel clock. A timing signal from the channel clock is measured in real time in the controller. Time intervals between sector identifier marks of the magnetic disk are detected using the timing signal from the channel clock during reading and writing operations of the hard disk drive in the controller. An inconsistency in the drive operations is detected in the controller based on changes in the time intervals between the sector identifier marks is detected during operation of the hard disk drive. The detection of the inconsistency in the drive operations is responded to.06-09-2011
20110134558DISK DEVICE, HEAD DISTANCE CALCULATION METHOD, AND OFFSET CONTROL METHOD - According to one embodiment, a disk device comprises a magnetic head module, a measurement module, and an arithmetic operation module. The magnetic head module includes a read head and a write head wherein an offset is present therebetween. The measurement module writes a measurement signal into a disk medium, reads the measurement signal while moving the read head in the radial direction, and obtains a measurement value of the offset based on a level of the read measurement signal. The arithmetic operation module obtains an estimate value of a distance between the write head and the read head based on a design value of the distance, a design value of the offset calculated by the design value of the distance, and the measurement value of the offset.06-09-2011
20110134556Detection and Acquisition of a Servo Pattern Subject to Lateral Motion - A method, a servo system and a tape drive are provided to acquire lock on a servo signal. The servo signals of at least one servo element are monitored to detect a valid servo signal. If a valid servo signal is not detected than the fine actuator is moved in a first direction until either a valid servo signal is detected or the fine actuator travel limit is reached. When a valid servo signal is detected, the fine actuator is set to a neutral position and the coarse actuator is moved in the first direction. When the fine actuator travel limit is reached the fine actuator is moved to the first position and the coarse actuator is moved in a second direction, opposite of the first direction.06-09-2011
20100165496SYSTEM, METHOD AND APPARATUS FOR SECTOR GRADING OF DEFECTIVE BIT PATTERNED MAGNETIC MEDIA IN HARD DISK DRIVES - A system for grading defective bit patterned magnetic media by disk sector in hard disk drives recovers a portion of any defective sectors at a lower areal density. The invention reduces the track pitch density for sectors containing amalgamated islands while leaving the remainder of the defect-free sectors in the zone optimized for linear bit density. This recovers a portion of the defective sector, approximately in proportion to the ratio of amalgamated islands over the original number of islands. A typical zone is first optimized for tracks per inch during formatting of the patterned media disk drive. The zone is then broken up into sectors that can each be optimized separately for linear bit density to ensure the maximum sustainable capacity for each sector.07-01-2010
20100165498Dependent Temperature Control Within Disk Drive Testing Systems - A method of controlling a temperature of a subject test slot in a cluster of test slots includes evaluating a request for a temperature change for the subject test slot to determine if sufficient power is available to achieve the requested temperature change, and inhibiting the requested temperature change unless or until sufficient power is determined to be available to achieve the requested temperature change.07-01-2010
20100079888ECCENTRICITY DETERMINATION FOR A DISK - Monitoring of the eccentricity of a pre-formatted servo pattern on a disk.04-01-2010
20100067136SYSTEM INCLUDING A HARD DISK DRIVE AND STRAY MAGNETIC FIELD SENSOR AND ASSOCIATED METHOD - A system includes a host device and a disk drive interfaced with the host device are described as well as an associated method. The disk drive includes a magnetic media for storing information using an actuator arrangement to perform a data access by moving at least one head proximate to the magnetic media. The information may be subject to corruption when the disk drive is exposed, during the data access, to a given stray magnetic field having a given minimum magnetic field intensity. The given stray magnetic field will not corrupt the information on the magnetic media with the actuator arrangement positioned away from the magnetic media. A stray magnetic field protection arrangement is configured for detecting an ambient magnetic environment for use in causing the actuator arrangement to park responsive to the detection of at least the given minimum magnetic field intensity.03-18-2010
20100067135Inspection Apparatus and Inspection Method of Magnetic Disk or Magnetic Head - The present invention is designed to support plural servo patterns by setting a portion of the information of the servo pattern as a detection pattern, comparing the demodulated pattern of the portion of the information with the detection pattern, and controlling an operation timing of a test according to a result of the comparison.03-18-2010
20100067134ADAPTIVE TRACK SHAPE CONTROL DURING SELF SERVO-WRITE - In a method for implementing track shape control during a self servo-write process, an error in a targeted path for writing servo data onto a first track of a disk is detected. The error is correlated with a second error for a targeted path in a previously written track of the disk. A correction is generated for a feed-forward signal used to position a writing element which is used to write servo data for a subsequent track of the disk.03-18-2010
20100067133COMMAND SUSPENSION IN RESPONSE, AT LEAST IN PART, TO DETECTED ACCELERATION AND/OR ORIENTATION CHANGE - In an embodiment, an apparatus is provided that may include circuitry to, in response at least in part to detected change in at least one of acceleration and orientation of storage, request suspension of at least one command currently stored in at least one pending command queue that is intended for execution, at least in part, by the storage. The at least one command having been previously issued by the circuitry but being currently unexecuted, at least in part, by the storage. The circuitry also being to store, in response at least in part to the detected change, at least one copy of the at least one command for later re-issuance by the circuitry, and to request replacement of at least one command in the at least one queue with at least one other command to park at least one head of the storage.03-18-2010
20100195235MEASUREMENT OF TRACK ECCENTRICITY ON BIT PATTERNED MEDIA - The eccentricity of tracks defined on a rotating bit patterned media are measured using a readback signal, and the measured eccentricity may be used to control centering of the disk relative to a rotational spindle and/or to control movement of a read/write head relative to a selected track on the disk.08-05-2010
20100195236DISK DRIVE TRANSPORT, CLAMPING AND TESTING - A disk drive transporter, for transporting a disk drive and for mounting a disk drive within a test slot, includes a frame configured to receive and support a disk drive. The frame includes sidewalls configured to receive a disk drive therebetween and sized to be inserted into a test slot along with a disk drive. The frame also includes a clamping mechanism operatively associated with at least one of the sidewalls. The clamping mechanism includes a first engagement element and a first actuator operable to initiate movements of the first engagement element. The first actuator is operable to move the first engagement element into engagement with a test slot after a disk drive being supported by the frame is arranged in a test position in a test slot.08-05-2010
20100165497STORAGE APPARATUS, CONTROL APPARATUS, AND CONTROL METHOD - According to one embodiment, a storage apparatus includes: a reader configured to read a sector recorded in a storage medium; a detector configured to detect a sync mark in the sector; a determiner configured to determine the position of the data region of the sector based on the sync mark detected by the detector; a data generator configured to generate data of the data region based on the data region, the position of the data region being determined by the determiner; a first judging module configured to judge whether the data generated by the data generator is normal; and a data compartment recorder configured to record a data compartment in the storage medium distinguishably from other data compartments, the recorded data compartment comprising a data region from which, among the data generated by the data generator, data judged as abnormal is generated.07-01-2010
20110149424DATA STORAGE DEVICE TESTER - A data storage device (DSD) tester for testing a DSD is disclosed. The DSD tester comprises a plurality of bays, a screen, and control circuitry operable to detect when a first DSD has been inserted into a first bay. Independent of operator input, a graphical user interface (GUI) displayed on the screen is automatically updated to reflect the first DSD has been inserted into the first bay. Independent of operator input, a DSD test is automatically executed on the first DSD. When the first DSD is removed from the first bay, independent of operator input, the GUI is automatically updated to reflect the first DSD has been removed from the first bay.06-23-2011
20110188143METHOD AND ITS APPARATUS FOR INSPECTING A MAGNETIC DISK - In order to implement efficient read/write testing by firstly determining read/write test area-sampling positions based on position information relating to any defects detected during optical inspection, and then conducting read/write tests only upon areas neighboring the defects detected during the optical inspection, a magnetic disk to be inspected is retained on a spindle and moved under this state between an optical type of inspection apparatus and a read/write test apparatus, in which apparatus configuration the read/write test apparatus uses position information on any defects detected by the optical type of inspection apparatus and conducts read/write tests only upon neighboring areas of the defects detected by the optical type of inspection apparatus.08-04-2011
20110188142DISC OPERATION SELECTION - A method of identifying a string or chain of efficient or “good enough” disc operations for processing (a pseudo optimal chain) is provided. A “pseudo optimal chain” comprises a string or chain of operations that, while not necessarily the optimal string or chain, provides an efficient sequence of operations that can be determined by comparing individual operations to predetermined selection criteria. In contrast to a true optimization technique that can require computing up to N! combinations for N operations, the string or chain of efficient or “good enough” disc operations allows for relatively simpler computations.08-04-2011
20100020427METHOD FOR MEASURING OFFSET AMOUNT BETWEEN HEADS IN A COMPOSITE MAGNETIC HEAD AND A MEASURING DEVICE USING THE METHOD - An offset amount between heads is calculated by positioning a head in a designated track under an ON track servo control, obliquely writing test data by moving the head in a radial direction of the magnetic recording medium at a designated moving speed K to cross the designated track and at least one track adjacent to the designated track according to a write start signal, reading the oblique test data by the read head from the adjacent track under the ON track servo control, detecting a peak position of a read voltage by using a read voltage characteristics of the read signal in the adjacent track and calculating the offset amount between the heads by detecting a scan time up to the peak position of the read voltage.01-28-2010
20110216431PROCESSING DISKS ON A SPIN STAND - A method of processing disks on spin stand is disclosed, the spin stand comprising a spindle motor having a rotor. A first disk is clamped to the rotor, wherein the first disk comprises a reference servo pattern. A second disk is clamped to the rotor, and a first head is servoed over the first disk in response to the reference servo pattern in order to position a second head over the second disk at a first radial location. Data is written to the second disk at the first radial location using the second head. The second disk is removed from the rotor while the first disk remains clamped to the rotor.09-08-2011
20110216430MAGNETIC HEAD INCLUDING SENSOR - A magnetic head disposed in a slider arranged with an interval with respect to a magnetic disk includes a sensor that is positioned in a stepped-back position from an air bearing surface facing the magnetic disk, an insulating film that is positioned on the air bearing surface and that covers the sensor; a pair of lead films, the lead films being electrically connected to the sensor such that at least portions of the lead films are exposed on the air bearing surface, and being configured to transfer a temperature change of the air bearing surface to the sensor.09-08-2011
20090231744MAGNETIC DISK DEVICE TESTING METHOD AND TESTING DEVICE - A magnetic disk device testing method includes obtaining index values indicating the signal quality of an adjacent track at different positions scattered in the width direction in the adjacent track located in the vicinity of a target track on a magnetic disk after repeatedly writing data onto the target track, and determining a representative value of the index values indicating the signal quality of the adjacent track based on the obtained results, while incrementing the number of data write times; and estimating an index value indicating the signal quality of the adjacent track to be obtained where data is written onto the target track a larger number of times than the total number of data write times the data has been actually written in obtaining the index values, the index value being estimated with the use of the representative values decided in the representative value deciding.09-17-2009
20110051274METHOD TO EVALUATE A DATA STORAGE DEVICE USING MAGNETIC SPACING LOSSES - A method of evaluating the performance of a magnetic recording system, comprising measuring a first set of finite impulse response filter tap values at time t03-03-2011
20120307391SYSTEM, METHOD, AND COMPUTER PROGRAM PRODUCT FOR SERVO COMPENSATOR SWITCHING IN HIGH VIBRATION ENVIRONMENTS - A tape drive system according to one embodiment includes a magnetic head having at least one servo sensor; a tape motion controller; a fine actuator; a skew actuator; a coarse actuator; and a control. The control is configured to perform various operations that help account for vibrations that effect track-following a servo track when operating a tape drive. Additional systems, methods and computer program products are also described.12-06-2012
20120307390SYSTEM, METHOD, AND COMPUTER PROGRAM PRODUCT FOR FAST RECOVERY TO A WRITE STATE - In one embodiment, a tape drive system includes a magnetic head having at least one servo sensor for track-following at least one defined servo track of a longitudinal tape, a tape motion controller configured to move the longitudinal tape past the magnetic head, a compound actuator configured to translate the magnetic head laterally with respect to the longitudinal tape, and a control configured to track-follow the at least one defined servo track by reducing a position error between the magnetic head and a desired position, transition from a write state to a monitor state when the position error is greater than a threshold, transition from the monitor state to a stop write state when the position error is greater than the threshold for a first period, and transition from the monitor state to the write state when the position error is less than the threshold for a second period.12-06-2012
20120307392METHOD FOR FAST RECOVERY TO A WRITE STATE - In one embodiment, a method includes sensing a servo sensor while a longitudinal tape is moved past a magnetic head, determining position error between the magnetic head and a desired position related to the at least one defined servo track; providing signals to operate a fine actuator to translate the magnetic head laterally in a manner to reduce the determined position error; transitioning from a write state to a monitor state when the determined position error is greater than a threshold error value; transitioning from the monitor state to a stop write state when the determined position error is greater than the threshold error value for a first predetermined period; and transitioning from the monitor state to the write state when the determined position error is less than the threshold error value for a second predetermined period.12-06-2012
20110141600DISK DEVICE AND OFFSET CONTROL METHOD THEREOF - According to one embodiment, a disk device comprises a memory, detector, calculation module, and deactivation module. The memory is configured to store an offset control amount at a time of manufacture. The detector is configured to detect a disk run-out. The calculation module is configured to obtain an offset control amount when the detector detects the disk run-out. The deactivation module is configured to deactivate the offset control based on a difference between the offset control amount obtained by the calculation module and the offset control amount at a time of manufacture stored in the memory and based on the offset control amount obtained by the calculation module.06-16-2011
20110141599Disk Drive And Method Of Writing Servo Write Tracks To A Disk - A system and method of writing servo write tracks to a rotating disk using a head having a read/write offset is disclosed. One embodiment utilizes a write element on the head to write the servo write tracks. A read element on the head is then positioned over the servo write tracks. The phase of a specific frequency component of the track shape error in the servo write track is measured during the positioning of the read element over the servo write track. A sine wave having a specific frequency and a phase is selected based on the measurement results. The sine wave is then applied to a servo system as a correction signal. A new servo write track is then written with the write element.06-16-2011
20110026154METHOD FOR CHARACTERIZING A MAGNETIC-RECORDING SYSTEM FOR THE PRESENCE OF ADJACENT-TRACK INTERFERENCE AND FAR-TRACK INTERFERENCE - A method for characterizing a magnetic-recording system for the presence of adjacent-track interference and far-track interference. The method includes writing a plurality of repeating pulse-waveforms on a data track of a magnetic-recording disk at a write element of a magnetic-recording head. The method further includes reading a plurality of read-back signals from the magnetic-recording disk over a band of pseudo-data tracks offset from the data track by corresponding pseudo-data-track offsets in a radial direction of the magnetic-recording disk at a read element of the magnetic-recording head. In addition, the method includes displaying a magnetic-recording-signature map synthesized from the read-back signals from the magnetic-recording disk.02-03-2011
20120038997SYSTEM FOR WRITE FAULT PROTECTION IN A HARD DISK DRIVE - This invention relates to a system and method performed by a controller in a hard disc drive to generate a write fault signal. The system performs in the following manner. The system begins by receiving a sample of a position error signal. The system then generates a control signal from the position error signal. A sample of the control signal is then captured by the system. The system then determines a parameter to test from the captured sample of the control signal. The absolute value of the parameter is then calculated and compared to a threshold value. The system then generates a write fault error signal in response to a determination that the absolute value of the parameter is greater than or equal to the threshold value.02-16-2012
20110075286SYSTEM, METHOD AND APPARATUS FOR DETERMINING TRACK PITCH IN A HARD DISK DRIVE TO SATISFY THE REQUIREMENTS OF BOTH OFF-TRACK CAPACITY AND ADJACENT TRACK ERASURE - Track pitch in a hard disk drive is selected to satisfy the requirements of both off-track capacity (OTC) and adjacent track interference (ATI). The invention separately measures the track pitch requirements for OTC and ATI. The track pitch for the drive is set with the larger of the OTC and ATI track pitches. The OTC track pitch is measured with a 747 curve, and the ATI track pitch is measured by the positions of adjacent tracks at which the on-track error rate is not worse than a given value after the targeted number of adjacent track writes in the ATI requirement.03-31-2011
20100007977HEAD STACK ASSEMBLY GRAMLOAD PROCESS CAPABILITY IMPROVEMENT - A method for measuring a gramload corresponding to a read/write head, where the head is an inner head of a plurality of heads in a head stack assembly (HSA), involves a measurement instrument having a plurality of cam-rods for systematically placing each of various heads in a preloaded state in order to measure the respective gramload of the heads. While an inner head's gramload is being measured, an adjacent inner head is configured in a supported state, and the cam-rod corresponding to the supported head transmits some additional force to the head whose gramload is being measured, e.g., via a common support arm for the adjacent inner heads. Therefore, this additional applied force is compensated for in order to provide more accurate gramload values.01-14-2010
20110317303MAGNETIC DISK DRIVE AND METHOD FOR ADJUSTING PARAMETER IN THE SAME - According to one embodiment, a magnetic disk drive includes a parameter management table, a parameter adjustment module and an interpolation module. The parameter management table stores a parameter used to write or read data to or from a disk in the parameter management table in association with each of a plurality of predetermined temperature divisions. The parameter adjustment module adjusts a first parameter stored in the parameter management table in association with a first temperature division to a second parameter adapted for the first temperature division if an ambient temperature detected by a temperature detector corresponds to the first temperature division and if the first parameter is unadjusted. The interpolation module updates an unadjusted third parameter corresponding to a third temperature division between the first temperature division and a second temperature division for which the parameter is adjusted based on a result of the adjustment of the first parameter.12-29-2011
20110317301NONLINEARITY MEASUREMENT APPARATUS, NONLINEARITY MEASUREMENT METHOD, AND MAGNETIC RECORDING AND REPRODUCTION APPARATUS - According to one embodiment, a non-linearity measurement apparatus includes a first measurement module, a second measurement module, and a calculation module. The first measurement module is configured to measure a component of a first higher harmonic from a reproduced signal of a first signal recorded on a magnetic recording medium. The second measurement module is configured to measure a component of a second higher harmonic from a reproduced signal of a second signal recorded on the magnetic recording medium. The calculation module is configured to calculate a non-linear transition shift of the magnetic recording medium by calculating an arcsine function of a value obtained by dividing the component of the second higher harmonic by the component of the first higher harmonic.12-29-2011
20110317302DISK STORAGE APPARATUS AND METHOD OF MEASURING FLYING HEIGHT OF A HEAD - According to one embodiment, a disk storage apparatus includes a read module, a measuring module, and a compensating module. The read module is configured to read first and second signals recorded on a disk, from which to measure the flying height of a head. The measuring module is configured to calculate the flying height of the head from the first and second measurement signals read by the read module. The compensating module is configured to use the data representing the flying height representing error resulting from superparamagnetic effect, thereby compensating for the flying height measured by the measuring module.12-29-2011
20090323212HANDLING ROBOT OF MAGNETIC HEAD ASSEMBLY, MAGNETIC HEAD TEST METHOD AND MAGNETIC HEAD TESTER - An upward warp of a terminal pad of a flexible cable which is kept horizontal by a suction head is prevented by a pressing arm which contacts with an upper surface of a rear portion of the flexible cable.12-31-2009
20120002314THERMAL READ/WRITE OFFSET COMPENSATION - A HDD comprising a temperature sensor disposed inside the HDD configured to periodically measure temperature inside of said hard disk drive; a magnetic disk; a read head; a write head; memory for storing RWO data. The RWO data is a function of a distance between the read head and the write head. The HDD also includes a RWO data adjustor configured to adjust the RWO data in response to a change in temperature of the HDD to compensate for a change in the distance between the read head and the write head based on the change in temperature.01-05-2012
20120008226FLY CAPABLE SLIDER TEST SOCKET - The present application is directed to a slider supporting apparatus for flying a slider of a hard disk drive in the manufacturing process to provide electrical performance characteristics. The present invention discloses an integrated design including the electrical interconnect, the gimballing mechanism, the preload mechanism and the slider supporting mechanism integrated into a single supporting structure.01-12-2012
20120206829METHOD OF TESTING MAGNETIC RECORDING MEDIUM - Disclosed is a method of testing a magnetic recording medium including a magnetically isolated magnetic recording pattern (08-16-2012
20110063746Systems and Methods for Improved Servo Data Operation - Various embodiments of the present invention provide systems, methods and media formats for efficiently determining a position error of a head in relation to a storage medium. In one case, a system is disclosed that includes a storage medium with a series of data. The series of data includes a first defined marker and a second defined marker located a distance from the first defined marker, and position location data. The systems further include a first detector circuit that is operable to detect the first defined marker and to establish a location of the first defined marker, and a second detector circuit that is operable to detect the second defined marker and to establish a location of the second defined marker. The systems further include an error calculation circuit and an interpolation circuit. The error calculation circuit is operable to calculate an interpolation offset based at least in part on the location of the first defined marker and the location of the second defined marker. The interpolation circuit is operable to interpolate the position location data and to provide an interpolated position location data.03-17-2011
20120044593TEMPERATURE INDUCED HEAD SKEW - One way to minimize full DC head-skew re-calibrations rendered necessary by changes in storage media drive operating temperature is to compensate for temperature-induced DC head-skew using a known relationship between temperature-induced DC head-skew and storage media operating temperature. More specifically, a first DC head-skew is measured at a first arbitrary temperature of the storage media drive. A second DC head-skew is measured at a second arbitrary temperature of the storage media drive. A DC head-skew correction factor is calculated using the first and second DC head-skews at the first and second arbitrary temperatures. When a multi-head storage media drive is powered-up for operation, a temperature sensor located in the storage media drive assembly measures the current storage media drive temperature. The head-skew correction factor is applied based on the measured temperature to correct the DC head-skew.02-23-2012
20120044594Method and System for Distinguishing Spatial and Thermal Defects on Perpendicular Media - Disclosed are a method and system for distinguishing spatial and thermal defects on perpendicular media. The magnetic domains of the perpendicular media are oriented to have a first polarity, scanned using a read head, oriented to have a second polarity and scanned again. The signals from the read head are combined to produce output signals having improved signal to noise ratios from which the locations of spatial and thermal defects can be identified and distinguished.02-23-2012
20120057255INSPECTION DEVICE OR INSPECTION METHOD FOR MAGNETIC HEAD OR MAGNETIC DISC, AND MAGNETIC DISC RECORDING DEVICE AND MAGNETIC DISC RECORDING METHOD - An inspection device or inspection method for a magnetic head or magnetic disc which can form a servo pattern applicable to a write system, and a magnetic disc recording device or magnetic disc recording method. In inspection or recording of a magnetic disc, which rotates the magnetic disc, a servo pattern is written into a servo pattern region of the magnetic disc by a write-in element of a magnetic head, and is read by a read-in element of the magnetic head. Servo following of a position of the magnetic head on the magnetic disc is performed based on the servo pattern which comprises a plurality of patterns. The patterns are written-in with a first frequency for causing the patterns to be subjected to the servo following and, the patterns are overwritten with a second frequency different from the first frequency, except a servo following width used in the servo following.03-08-2012
20120014010DETERMINING A REFERENCE WAVEFORM USED BY A CORRELATOR IN A SERVO CHANNEL - Provided are a method, servo channel, and tape drive for determining a reference waveform used by a correlator in a servo channel. Sequences of servo signal samples are provided from read servo signals read from a servo pattern on a recording medium. A determination is made of a reference waveform based on the sequences of servo signal samples and the reference waveform is forwarded. Interpolated servo signals are generated. The interpolated servo signal samples and the forwarded reference waveform are received to generate correlation output samples. Position and velocity information are calculated from the correlation output samples.01-19-2012
20110085258Magneto-resistive devices, information storage devices including the same and methods of operating information storage devices - An information storage device includes a magnetic track and a magnetic domain wall moving unit. The magnetic track has a plurality of magnetic domains and a magnetic domain wall between each pair of adjacent magnetic domains. The magnetic domain wall moving unit is configured to move at least the magnetic domain wall. The information storage device further includes a magneto-resistive device configured to read information recorded on the magnetic track. The magneto-resistive device includes a pinned layer, a free layer and a separation layer arranged there between. The pinned layer has a fixed magnetization direction. The free layer is disposed between the pinned layer and the magnetic track, and has a magnetization easy axis, which is non-parallel to the magnetization direction of the pinned layer.04-14-2011
20120206828COMMUNICATION APPARATUS - A communication apparatus is configured to execute testing of whether or not the responding module is correctly responding to the plurality of commands transmitted and received between a transmission module and a reception module, the testing being performed via a loop-back mode transmission and reception path configured such that the reception module receives the command transmitted by the transmission module; and during the testing, following procedure is performed, which includes: transmitting the specific command by the transmission module; receiving the specific command by the reception module via the transmission and reception path; deactivating reception of the specific command; and transmitting a command different from the specific command subsequent to transmitting the specific command by the transmission module.08-16-2012
20120026622METHOD AND APPARATUS FOR INSPECTING MAGNETIC DISK - In order to enable a highly-sensitive certifying test by detecting a signal with a high S/N ratio while controlling the glide height of a magnetic head to be optimized at the time of the certifying test, a method for inspecting a magnetic disk by conducting the certifying test for the magnetic disk using the magnetic head incorporating a heater includes: writing data into the magnetic disk using the magnetic head; and reading the data written into the magnetic disk using the magnetic head. Electric power applied to the heater incorporated in the magnetic head is switched between when writing the data and when reading the data.02-02-2012
20120026621MAGNETIC DISK APPARATUS AND SLIDER CONTROL METHOD - In one embodiment, there is provided a magnetic disk apparatus. The apparatus includes: a recording medium including a recording surface for recording information; a slider including a head configured to write information to the recording medium or read information from the recording medium; and a controller configured to control moving of the slider so as to remove a substance adhered to the slider and such that the slider is stopped at a position where the slider and the recording surface of the recording medium do not interfere with each other after the slider is moved at a given velocity or acceleration.02-02-2012
20120026620METHODS AND APPARATUS FOR GAIN ESTIMATION USING SERVO DATA WITH IMPROVED BIAS CORRECTION - Methods and apparatus are provided for gain estimation using servo data with improved bias correction. The gain is estimated using a preamble in a servo sector by obtaining a first gain estimate using a first gain estimation algorithm (such as a Zero Gain Start Algorithm) and a first portion of the preamble; storing the first portion of the preamble in a memory buffer; obtaining a second gain estimate using a second gain estimation algorithm (such as a Zero Forcing algorithm) and the first portion of the preamble; and processing Servo Address Mark (SAM) and Gray data in the servo sector using the first gain estimate substantially simultaneous to the step of obtaining the second gain estimate. A gain error can be obtained by calculating a difference between the first gain estimate and the second gain estimate. The gain error can be used in burst processing of the servo data.02-02-2012
20120026619WRITE PERFORMANCE MONITOR IN A STORAGE DEVICE - An apparatus comprising a write circuit, a processing circuit and a monitor circuit. The write circuit may be configured to generate one or more write control signals in response to an input signal. The processing circuit may be configured to generate an intermediate control signal in response to (i) the input signal, (ii) a reference clock signal and (iii) one or more user input signals. The monitor circuit may be configured to generate a sample signal in response to (i) the write control signals and (ii) the intermediate signal. The sample signal may represent a waveshape of the write control signals used to monitor writing to a data storage system.02-02-2012
20120300328Storage device with shingled data and unshingled cache regions - Shingled magnetic recording (SMR) devices according to embodiments of the invention include unshingled cache regions that can be used for storage of data. The unshingled cache regions can be used in a variety of flexible ways including in an implementation of write-twice caching or for opportunistic temporary storage to improve performance. The cache regions can be offset between top and bottom surfaces of the disk and staggered between disks to provide shorter seek times to the nearest cache region. Embodiments of the invention are adapted for use with symmetric or asymmetric heads.11-29-2012
20120300327SYSTEM AND METHOD FOR IMPROVING HEAD POSITIONING - Systems and methods for improving accuracy of head positioning using existing servo patterns are provided. In one embodiment, a method for improving read head positioning is provided that comprises: writing a series of tracks over a range of read offsets to be calibrated; measuring a set of raw track profiles from the series of tracks; sampling the set of raw track profiles at a series of signal amplitude levels; constructing a reference track profile from the set of sampled track profiles; calculating a set of read offset deltas from each sampled track profile; merging the sets of read offset deltas into a set of average read offset deltas; and converting the set of average read offset deltas into a read offset correction table. A similar method for improving disk write head positioning is also provided which utilizes such a read offset correction table to eventually create write offset correction table.11-29-2012
20090135512ELECTRICAL CURRENT AS PROBE FOR MODULATION AT HEAD-DISK INTERFACE - A system and method for measuring the modulation between a magnetic head and a magnetic storage medium, such as a disk, is disclosed. A magnetic read/write head is positioned above a magnetic storage medium at a given flying height. The magnetic read/write head reads a signal from the magnetic storage medium. A tester measures an alternating electric current between the magnetic read/write head through the slider and the magnetic storage medium. A computer may then calculate the modulation by the magnetic read/write head based on the alternating electric current. A DC voltage to the head may be applied to lower the flying height of the magnetic head.05-28-2009
20120250174INFORMATION RECORDING DEVICE AND INFORMATION RECORDING METHOD - According to one embodiment, an information recording device includes: a magnetic recording medium having tracks; a detector configured to detect widths of fringing phenomena that occur on both sides, in a track arrangement direction, of a track during recording on the track; and a recording controller configured to control recording so that adjacent tracks overlap with each other and that a track pitch is set at least on the basis of a smaller one of the detected fringing widths and a data read width for reading of data from the track.10-04-2012
20100290145DATA LOSS PREVENTION DURING A FALL OF A STORAGE DEVICE - A data storage circuit includes a hard disk drive (HDD) and a fall sensor. The HDD includes a rotatable media platter operable to receive and store data; a read/write head operable to communicate with the media platter by writing data to the media platter and by reading the data from the media platter; an arm supporting the read/write head; a motor coupled to the arm and operable to move the arm to and from the media platter; a drive controller operable to control the media platter, the read/write head and the servo motor; a general purpose input/output (GPIO) terminal coupled to the drive controller; and a data interface terminal coupled to the drive controller. The fall sensor is communicatively coupled to the drive controller and is configured to send an interrupt trigger signal to the drive controller when the drive is falling. The interrupt trigger signal is sent via the GPIO terminal when the HDD is free fall sense enabled and the interrupt trigger signal is sent via the data interface terminal when the HDD is not free fall sense enabled.11-18-2010
20100290144INVARIANT MULTI-DIMENSIONAL VIBRATION-RESILIENCE-SIGNATURE GENERATION SYSTEM - One embodiment of the present invention provides a system that generates vibration-resistance signatures for hard disk drives (HDDs). In this system, a set of HDDs is mechanically affixed to a disk enclosure. The system additionally includes a vibration generator which is mechanically coupled to the disk enclosure and can apply a translational vibration profile to the disk enclosure. The system further includes a coupling mechanism between the set of HDDs and the disk enclosure which translates the translational vibration profile into both translational and rotational vibrations for the set of HDDs in multiple dimensions. The system additionally includes a monitoring mechanism which monitors an HDD performance metric from the set of HDDs while the HDDs are subject to the translational and rotational vibrations. The system also includes a signature-generation mechanism which uses the monitored HDD performance metric to generate vibration-resistance signatures for the set of HDDs.11-18-2010
20100246043MEASURING READER/WRITER OFFSET IN A TAPE DRIVE HEAD - In a method of electronically measuring reader/writer offset in a tape drive head, a plurality of sequentially adjacent data tracks are written on a tape with a write head. Error rate information is measured while reading a data track of the plurality of sequentially adjacent data tracks with a read head of the tape drive. A bathtub shaped curve is built from a set of the error rate information which is accumulated by reading the data track at a plurality of offsets of the read head relative to the data track. Offset of the read head relative to the write head is measured by determining an offset of the read head which correlates to a magnetic center of the data track as represented by a center point between edges of the bathtub shaped curve.09-30-2010
20100246042Device of evaluating magnetic read head and method of evaluating magnetic read head - An MR element having a magnetically free layer and a magnetic bias layer that applies a bias magnetic field to the magnetically free layer are included. Furthermore, a measuring section that measures a ferromagnetic resonance frequency f09-30-2010
20120212848OVERWRITE CONTROL METHOD FOR DATA IN TAPE RECORDING APPARATUS, AND TAPE RECORDING APPARATUS - A data-overwriting technique that facilitates determining whether data is new or old. A tape recording apparatus includes: a receiving unit for receiving information on overwrite starting position and an overwrite request; a trying unit for trying to determine a beginning position of a data unit; an overwrite executing unit for executing overwriting from the determined overwrite starting position in response to a success of the determination by the trying unit; and a type judging unit for judging whether the data unit that is recorded at the overwrite starting position is a null data unit or not in response to a failure of the determination by the trying unit. The trying unit responds to judgment that the data unit is the null data unit by determining a beginning of a data unit following the data unit as the overwrite starting position.08-23-2012
20120212847INFORMATION RECORDING DEVICE AND INFORMATION RECORDING METHOD - According to one embodiment, an information recording device includes: a magnetic recording medium having tracks; and a recording controller configured to control recording of information on a track provided between a first track group and a second track group adjacent to the first track group, the first track group and the second track group being included in a plurality of track groups, each of which includes a plurality of adjacent tracks partially overlap each other.08-23-2012
20120212846Method of Calibrating Data Readers Relative to Servo Readers - A method of calibrating a servo reader and a read/write head for a data storage tape machine that reads and writes data to a data storage tape. The data storage tape has a servo pattern that is recorded on the tape in a known location. The servo pattern is used to provide precise position information for the data storage tape. According to the method, data is recorded on the data storage tape and the location of the data storage track is read. The location of the data storage tape is compared to the known location of the servo pattern to establish a reader offset value. The data storage tape machine is updated based upon the reader offset value to adjust the position of the read/write head.08-23-2012
20120134042Systems and Methods for Signal Polarity Determination - Various embodiments of the present invention provide systems and methods for determining head polarity. As an example, a head polarity detection circuit includes: a first computation circuit, a second computation circuit, and an inversion determination circuit. The first computation circuit is operable to sum an absolute value of each sample of a first subset of a series of data samples corresponding to a first phase of an analog input to yield a first sum, and the second computation circuit is operable to sum an absolute value of each sample of a second subset of the series of data samples corresponding to a second phase of the analog input to yield a second sum. The first phase is more than ninety degrees offset from the second phase.05-31-2012
20100328801DISK DRIVE - According to one embodiment, a disk drive includes a disk medium, a read controller configured to perform a read control for information in the disk medium, a determiner configured to determine whether or not to ignore a read error in information as a read target depending on a type of the information, and a transmitter configured to transmit the information to a host device without read error detection for the information read by the read controller if the determiner determines to ignore the read error.12-30-2010
20100328800Magnetic recording apparatus and magnetic recording evaluating apparatus - A magnetic recording apparatus includes: a magnetic recording medium having a recording surface on which a plurality of magnetic recording cells magnetically isolated from each other are arranged; a magnetic writing element recording information to the magnetic recording cells under a condition in accordance with setting information; a magnetic reading element reproducing information recorded in the magnetic recording cells; a memory storing the setting information for writing; and a processor for executing a program code. The program code includes a test module, responsive to a test write start signal, for repeating writing and reading test information by the magnetic writing and reading elements and calculating a quality index value representing quality of writing of the reproduced test information with the setting information changed, and a write module for selecting setting information with which the quality index value satisfies a predetermined condition, and writing the selected information in the memory.12-30-2010
20100328798SYSTEM AND METHOD FOR DETERMINING VIBRATION OF AT LEAST ONE HARD DISK DRIVE - A system for determining vibration of at least one hard disk drive includes one or more computers configured to command a plurality of reads from the at least one hard disk drive such that, for each of the plurality of reads, data stored on the at least one hard disk drive is retrieved directly from the at least one hard disk drive. The one or more computers are also configured to obtain read rate information related to the plurality of reads and to determine a vibration level experienced by the at least one hard disk drive based on the read rate information.12-30-2010
20100020428METHOD FOR MEASURING WRITE/READ WIDTH OF A COMPOSITE MAGNETIC HEAD AND A MEASURING DEVICE USING THE METHOD - A test data is written in tracks of a DTM by making the tracks eccentric by accessing a plurality of tracks by forcibly making a composite magnetic head eccentric under an ON track servo control. The test data written in the tracks which are pseudo-eccentric are written in the tracks with the original write sensitive width of a write head. It is possible to obtain a read characteristics profile having a peak by tracing and reading the test data while moving the composite magnetic head (read head) which is forcibly made eccentric in a radial direction.01-28-2010
20100027148TRIPLE TRACK TEST FOR SIDE ERASE BAND WIDTH AND SIDE ERASE AMPLITUDE LOSS OF A RECORDING HEAD - A triple track test for determining respective erase band widths associated with a read/write head involves writing first and second data tracks in each direction and at a certain distance from an origin, and erasing a track having a center at the origin. Based on a triple track test profile (3T) corresponding to the three tracks, a first distance is measured in one direction from the origin to one of the modified data tracks and a first erase band width is computed based thereon. The other side erase band width is computable similarly. A side erase amplitude loss measurement procedure, for determining the amount of signal amplitude lost by an adjacent track due to the respective erase bands, involves constructing a side-erase profile based on a composite of the 3T profile and a full-track profile, from which respective amplitude losses are computed for the respective erase bands.02-04-2010
20120176699MAGNETIC READING AND WRITING DEVICE - In a magnetic reading/writing device, a controller derives at each radius of a recording medium a slope of a curve of track-averaged write performance with respect to an adjustment parameter, and determines a first set of fitting coefficients of a first equation approximating the derived slopes in terms of a first variable representing each radius. The controller acquires write performance dependence on a variable representing each of multiple circumferential positions of the medium by measuring track average write performance with respect to the circumferential positions, and determines a second set of fitting coefficients to approximate by a periodic function the acquired dependence in terms of the first variable. The controller corrects a condition value representing the adjustment parameter by subtracting from the condition value an adjustment value obtained from functions calculated with the first and second sets of fitting coefficients.07-12-2012
20120075738INSPECTION APPARATUS AND INSPECTION METHOD FOR MAGNETIC HEAD OR MAGNETIC DISK AND INSPECTION METHOD FOR MAGNETIC HEAD - An inspection apparatus and method for a magnetic head or a magnetic disk is conducted using a two-carriage method. In particular, the magnetic disk is rotated by a spindle, a test signal is written into the magnetic disk by one magnetic head mounted in one carriage which moves in the radius direction of the magnetic disk, and the test signal of the magnetic disk is read by the other magnetic head mounted in the other carriage which moves in the radius direction of the magnetic disk to inspect the performance of the magnetic head or the magnetic disk using the read signal. The sector pulses to determine servo timing at which servo burst signals preliminarily written into the disk are read are formed on the basis of a clock signal and an index signal generated along with the rotation of the spindle.03-29-2012
20120176698Reducing Errors Resulting from Width Variability of Storage Media Write Tracks - Various approaches that reduce the width variability of storage media data tracks are described. First and second data tracks are written so that the second track overlaps the first track. After writing the second track data to the second track, an effective width of the first track is determined. The effective width of the first track is the portion of the first track that is not overlapped by the second track. One or more additional write operations to the recording medium are performed to compensate for the effective width of the first track being less than a threshold. The additional write operations may include one or more of rewriting the first track data to a third track on the storage medium and writing additional redundancy information to supplement the coding of the first track data.07-12-2012
20100271723HARMONIC SELECTION FOR TRACK FOLLOWING ON A HARD DISK DRIVE - Harmonic selection for track following is described for a hard disk drive comprising at least one magnetic disk capable of storing data and spinning, a controller capable of controlling a read/write head capable of reading and writing data while following a track on a surface of the at least one magnetic disk, and a memory device capable of storing data relating to the operation of the hard disk drive. A drive function test on the hard disk drive is performed, during which harmonic frequencies are identified which cause disturbances for the hard disk drive. Data regarding the harmonic frequencies which cause the greatest disturbances for the hard disk drive is stored in the memory device. The data regarding the harmonic frequencies which cause the greatest disturbances is forwarded to the controller upon the at least one magnetic disk spinning.10-28-2010
20100039724MAGNETIC RECORDING MEDIUM - In order to provide a magnetic recording medium having excellent electromagnetic conversion characteristics, a magnetic recording medium (02-18-2010
20100007979MAGNETIC DISC APPARATUS, GAS SENSOR, AND THEIR MANUFACTURE METHOD - A magnetic recording medium having a first lubricant layer formed on the surface thereof and a gas sensor are disposed in a housing. The gas sensor detects gas by adsorbing the gas on a detection surface thereof The detection surface is formed with a second lubricant layer made of the same lubricant agent as that of the first lubricant layer.01-14-2010
20100007978DETECTION OF DEFECTIVE TAPE DRIVE BY AGGREGATING READ ERROR STATISTICS - A plurality of tape drives writes a plurality of indicators corresponding to a plurality of data units on a tape, wherein an indicator indicates which tape drive of the plurality of tape drives has written a corresponding data unit on the tape. Each of the plurality of tape drives generates an extent of read errors, in response to reading the plurality of data units written on the tape. The extent of read errors generated by each of the plurality of tape drives are aggregated at a computational device coupled to the plurality of tape drives. A determination is made at the computational device of a defective tape drive of the plurality of tape drives from the aggregated extent of read errors.01-14-2010
20100007976PROTECTING MAGNETIC HEAD ELEMENTS - A magnetic head is described herein. A method for manufacturing the magnetic head comprises determining a protective distance for a protective structure to extend beyond an element in a direction toward a disk, layering the protective structure, and removing material from the protective structure to obtain approximately the protective distance. The protective distance is from an element end to a protective structure end. The protective distance is determined based on a magnetic head profile. The thickness of the protective structure is based on pole-tip recession.01-14-2010
20120262813DATA RECORDING METHOD, DATA RECORDING APPARATUS, AND RECORDING MEDIUM - The data recording apparatus for recording data to a recording medium having one or more tracks arranged in parallel comprises a data recorder configured to record data to the one or more tracks, a memory configured to store data, and a controller configured to control the data recorder. The controller determines whether or not the one or more tracks include a data defective region in which the data has not been recorded properly, stores in the memory the data that has not been recorded properly, designates a position corresponding to the data defective region, which is in a track arranged in parallel to the data defective region, and reads from the memory the data that has not been recorded properly, and records that data to the position corresponding to the data defective region.10-18-2012
20120262812TEST APPARATUS AND METHOD OF TESTING WITH A TEST APPARATUS - There is disclosed a test apparatus for performing testing with a read/write head and method of testing with a test apparatus. The test apparatus includes a head load mechanism for receiving and positioning the read/write head during testing and a multi-channel preamplifier arranged to interface plural channels to a measurement system. A first channel of the multi-channel preamplifier has a connector for connecting to the read/write head. One or more other channels of the multi-channel preamplifier is connected to or has a connector for connecting to another device for interfacing that device to the measurement system.10-18-2012
20120229928DISK STORAGE DEVICE AND METHOD FOR MEASURING HEAD FLYING HEIGHT - According to one embodiment, a disk storage device comprises a controller, a recording module, a read module, and a detector. The controller is configured to control a head flying height with respect to a storage medium to a predetermined value. The recording module is configured to record a measurement signal on the storage medium when the controller controls the head flying height to the predetermined value. The read module is configured to read the measurement signal from the storage medium when the controller controls the head flying height to the predetermined value. The detector is configured to detect the head flying height based on the measurement signal read from the read module.09-13-2012
20100238575WRITE DRIVER MONITORING AND DETECTION - Electronic circuitry and methods are disclosed for monitoring a portion of a write driver, for example, a steady state value of a write driver of a hard disk drive preamplifier. Based on a result of the monitoring, a condition, such as a fault, can be detected in the write driver. For example, apparatus for monitoring a write driver of a disk drive system comprises a comparator circuit coupled to an output of the write driver and configured to compare a value present at the output of the write driver with a reference value such that at least one condition associated with the write driver is detectable as a result of the comparison of the write driver output value and the reference value.09-23-2010
20100328799Spin Torque Oscillator Sensor - A spin torque oscillation magnetoresistive sensor for measuring a magnetic field. The sensor uses a change in precessional oscillation frequency of a magnetization of a magnetic layer to determine the magnitude of a magnetic field. The sensor can include a magnetic free layer, a magnetic pinned layer and a non-magnetic layer sandwiched therebetween. Circuitry is connected with these layers to induce an electrical current through the layers. Spin polarization of electrons traveling through the device causes a spin torque induced precession of the magnetization of one or more of the layers. The frequency of this oscillation modulates in response to a magnetic field. The modulation of the oscillation frequency can be measured to detect the presence of the magnetic field, and determine its magnitude.12-30-2010
20110235204DETECTION OF HARD-DISC DEFECT REGIONS USING SOFT DECISIONS - In a hard-disc drive, a defect region on the hard disc is detected by generating two statistical measures (e.g., β09-29-2011
20110242692DATA-DEPENDENT NOISE-PREDICTIVE MAXIMUM LIKELIHOOD DETECTION (DD-NPML) FOR MAGNETIC RECORDING - In one embodiment, a method includes applying one or more whitening filters to an input stream of digitized samples from a magnetic data channel to produce a filtered sequence, performing one or more branch metric calculations to the filtered sequence to produce a branch metric, and applying a multi-state data-dependent noise-predictive maximum likelihood (DD-NPML) detector to the branch metric to produce an output stream. In another embodiment, a multi-channel data storage system includes a head for reading data from a storage medium, logic for applying one or more whitening filters to an input stream of digitized samples from a magnetic data channel to produce a filtered sequence, logic for performing one or more branch metric calculations to the filtered sequence to produce a branch metric, and logic for applying a multi-state DD-NPML detector to the branch metric to produce an output stream. Other systems and methods are described as well.10-06-2011
20110249355METHOD AND SYSTEM FOR ERROR CHECKING IN BIT-PATTERNED MEDIA - A disc drive system provides increased reliability by detecting and correcting errors associated with bit-patterned media. Write synchronization errors associated with bit-patterned media are addressed by including data storage for temporarily storing data that is being written to the disc drive. The data is read from both the disc drive and the storage medium and compared to detect write synchronization errors. The disc drive system utilizes the identified write synchronization errors for at least one of timing recovery, equalizer training detection, error correction code application, and error recovery.10-13-2011
20120092787MAGNETIC HEAD AND DISK DRIVE WITH THE SAME - According to one embodiment, a magnetic head includes a magnetic core including a main pole, and a return pole opposed to the main pole with a magnetic gap therebetween, and configured to return magnetic flux from the main pole and form a magnetic circuit in conjunction with the main pole, a coil configured to excite magnetic flux in the magnetic circuit, and a nonmagnetic electrically conductive layer formed by disposing only a nonmagnetic material in the magnetic gap between the return pole and an end portion of the main pole on the recording medium side, and configured to electrically connect the main pole and the return pole. The main pole, the nonmagnetic electrically conductive layer, and the return pole are configured to constitute a series electrical circuit.04-19-2012
20120327529METHOD FOR ACTIVE CONTROL OF SPACING BETWEEN A HEAD AND A STORAGE MEDIUM - A head using heaters or actuators to control head media spacing is disclosed. In embodiments disclosed the heaters are selectively energized to control a close point of the head for read and/or write operations. As disclosed power is supplied to multiple heaters to generate heat induced protrusion data and the heat induced protrusion data is used to apply power to the multiple heaters for head media spacing control.12-27-2012
20100142074HEAD EVALUATING METHOD AND DEVICE, AND INFORMATION STORAGE APPARATUS - According to one embodiment, a method evaluates a head comprising a read element, a recording element, a coil, and a heater to change a projection amount of the elements by thermal expansion. The method includes: floating the head over the medium rotated; projecting including conducting electricity through the heater with an electric power, and projecting the elements toward the medium; first recording including stopping the conduction, and recording data in a sector on the medium after the stopping; second recording of recording data in another sector on the medium; reproducing the recorded data to obtain their reproducing characteristics; and obtaining including repeating the projecting, first and second recording, and reproducing, while changing the electric power in the projecting, obtaining the electric power for the heater at which the characteristics equal each other to compute the projection amount due to a current fed through the coil upon recording.06-10-2010
20100134911MULTI-PARAMETER OPTIMIZATION OF WRITE HEAD PERFORMANCE USING ADAPTIVE RESPONSE SURFACE - A method for optimizing design parameters of a magnetic write head. The method involves compiling a table of data points for a plurality of design parameters. An experimentally derived optimal design point is determined a first set of tests are performed at this experimentally determined design point. A three dimensional response surface is generated based on the testing. Then, a projected optimal design point is determined from the three dimensional response surface. Another test is performed using this projected optimal design point, and a convergence is determined by comparing the results of the first and second tests. If the convergence is within a predetermined value, then the process is complete. If the convergence is not within the predetermined value, then the process is repeated using the most recent projected optimal design point.06-03-2010
20100091398Disk clock system with up-sampler to generate frequency offset - A system reads data from a magnetic storage media. A read head reads data from the magnetic storage media and produce an analog signal. A variable gain amplifier amplifies the analog signal. An offset adjust module substantially centers the amplified analog signal to a midscale. A Magneto Resistive Asymmetry (MRA) correction module MRA corrects the amplified analog signal. A Continuous Time Filter (CTF) compensation module processes the amplified analog signal. An Analog to Digital Converter (ADC) samples the amplified analog signal based upon a control signal to produce a digital signal. A Disk Lock Clock (DLC) system produces the control signal to the ADC. The control signal is representative of a frequency offset caused by at least one servo wedge rate error. A Finite Impulse Response (FIR) filter module filters the digital signal. A sequence detector processes the digital signal and detects a bit sequence from the digital signal.04-15-2010
20080239538METHOD OF EXAMINING APERTURE DIAMETER OF DISK SUBSTRATE HAVING CIRCULAR APERTURE IN CENTRAL PORTION THEREOF AND APPARATUS THEREOF - The present invention relates to a method of examining an aperture diameter of a disk substrate having a circular aperture in the central portion thereof, the method including: attempting to pass a standard sphere for the aperture diameter through the aperture; and inspecting the aperture diameter of the disk substrate, based on whether the sphere passes through the aperture or not. Furthermore, the present invention relates to an examination apparatus thereof.10-02-2008
20080225426Magnetic recording device including a thermal proximity sensor - A system includes a magnetic device for writing to and reading from a magnetic medium and a sensor disposed adjacent to the magnetic device and proximate to the magnetic medium. The sensor generates signals related to thermal variations in the sensor caused by changes in a distance between the magnetic device and the magnetic medium.09-18-2008
20130170060MICROWAVE-ASSISTED MAGNETIC RECORDING HEAD AND SYSTEMS THEREOF WITH ENVIRONMENTAL CONDITIONS CONTROL - In one embodiment, a system includes a medium, a magnetic head having a write element adapted for writing data to the medium, a MAMR element and/or a TAMR element adapted for assisting recording on the medium, the MAMR element having a microwave-generating portion that receives current for operation thereof, the TAMR element having a localized heat-generating portion that receives current for operation thereof, and a read element adapted for reading data from the medium, a device adapted for measuring environmental conditions relating to the TAMR/MAMR elements and the medium, and a controller adapted for controlling operation of the magnetic head and adjusting operating parameters of the system based on the environmental conditions. The environmental conditions include temperature, a reproduced signal of the read element, and/or clearance between the TAMR/MAMR elements and the medium. The operating parameters include the clearance, amount of current injected to the TAMR/MAMR elements, and/or write current.07-04-2013
20120250175INSPECTION DEVICE AND INSPECTION METHOD FOR INSPECTING MAGNETIC DISK OR MAGNETIC HEAD - The present invention realizes reduction of position information demodulation errors caused by the eccentricity of the magnetic disk and improvement of position signal detection accuracy, as well as enabling quick eccentricity clock correction for arbitrary clock frequencies. An inspection device in accordance with the present invention comprises: a servo demodulation unit which demodulates servo information; a PLL clock generating unit which generates a reference clock and supplies the reference clock to the servo demodulation unit; and a tester control unit. The PLL clock generating unit includes an eccentricity correction circuit for correcting the frequency of the reference clock depending on the eccentricity of the magnetic disk. The tester control unit generates correction data for correcting the frequency of the reference clock, multiplies the correction data by the inverse of a transfer function of the PLL clock generating unit, and supplies the product to the eccentricity correction circuit.10-04-2012
20130094104Head DFH protrusion shape calibration by HDI sensor - Dynamic fly height (DFH) controlled read/write heads using multiple heaters have their heater powers set within a range of ratios that allows minimum clearances to be set between the read-gap and the write-gap and the surface of a disk, thereby providing improved touch-down detection. Determining the correct range of power ratios requires varying the ratio to create an adjustable protrusion profile for the read and write elements in the head and measuring values of the ratio and corresponding values of read gap and write gap clearances that create points of minimum clearance. By adjusting the ratio of power supplied to the heaters, different protrusion profiles can be produced, clearance control for sigma reduction can be obtained and read/write readiness and operation consistency and reliability can be improved.04-18-2013
20130128373DATA STORAGE DEVICE AND METHOD OF PROCESSING A SIGNAL IN A DATA STORAGE DEVICE - According to embodiments of the present invention, a data storage device is provided. The data storage device includes a recording channel configured to carry a signal; a detector configured to detect the signal from the recording channel; and a noise prediction circuit configured to predict noise affecting the recording channel and the detected signal based on a noisy channel model. According to further embodiments of the present invention, a method of processing a signal in a data storage device is also provided.05-23-2013
20130128372METHOD AND SYSTEM FOR ERROR CHECKING IN BIT-PATTERNED MEDIA - A disc drive system provides increased reliability by detecting and correcting errors associated with bit-patterned media. Write synchronization errors associated with bit-patterned media are addressed by including data storage for temporarily storing data that is being written to the disc drive. The data is read from both the disc drive and the storage medium and compared to detect write synchronization errors. A disc drive system for correcting write synchronization errors includes an encoder, non-volatile storage, and decoder device for implementing a parity-based scheme for increased reliability. Data strings being written to the disc drive are combined in an encoder to generate a parity string. The address of the data being written to the disc drive, along with the updated parity string is stored to the non-volatile storage. The data strings are read from the disc drive by the decoder. If uncorrectable errors are identified, the decoder employs the parity string in conjunction with the other data strings written to the disc drive to reconstruct the data string with uncorrectable errors.05-23-2013
20130135764IMPLEMENTING DATA TRACK PITCH ADJUSTMENT UNDER OPERATIONAL VIBRATION CONDITIONS - A method, apparatus and a data storage device are provided for implementing data track pitch adjustment for data written on a recordable surface of a storage device under operational vibration conditions. An operational vibration disturbance spectrum is detected during a write operation and the data track pitch is selectively adjusted based on the detected operational vibration disturbance spectrum. The adjusted track pitch information is saved and used during a read operation.05-30-2013
20110222181COMMUNICATION APPARATUS - A communication apparatus is configured to execute testing of whether or not the responding module is correctly responding to the plurality of commands transmitted and received between a transmission module and a reception module, the testing being performed via a loop-back mode transmission and reception path configured such that the reception module receives the command transmitted by the transmission module; and during the testing, following procedure is performed, which includes: transmitting the specific command by the transmission module; receiving the specific command by the reception module via the transmission and reception path; deactivating reception of the specific command; and transmitting a command different from the specific command subsequent to transmitting the specific command by the transmission module.09-15-2011
20110222180METHOD AND SYSTEM FOR INTERROGATING THE THICKNESS OF A CARBON LAYER - A method and system for interrogating a thickness of a carbon layer are described. The carbon layer resides on at least one of a magnetic recording head and a magnetic recording disk. The method and system include providing an enhancement film on the carbon layer. The enhancement film is continuous across a portion of the carbon layer. The method and system also include exposing the enhancement film to light from a light source and detecting scattered light from the carbon layer to provide a surface enhanced Raman spectroscopy (SERS) spectrum. The enhancement film resides between the light source and the carbon layer. The method and system also include determining the thickness of the carbon layer based on the SERS spectrum.09-15-2011
20080198493TEST METHOD OF A MAGNETIC DISK AND MAGNECTIC DISK TESTER - A test burst signal is overwritten from a write end position over a connecting region determined by positional deviation between a read head and a write head and a peripheral speed of a disk. Since, therefore, the overwritten signal portion is overlapped on the test burst signal written at a write start point, it is possible to reduce a width of the connecting region to thereby reduce a test inhibit region.08-21-2008
20080198492HARD DISK DRIVE AND ASSOCIATED METHOD FOR OPTIMIZING WRITE PARAMETERS - A hard disk drive which can maintain a write property at a constant level by reflecting a temperature effect during a write parameter set process even when the hard disk drive is used under a condition different from one intended during manufacturing of the disk. The hard disk drive includes a disk, a thermister and a controller. The disk stores data and the thermister measures the temperature around the disk. The controller is coupled to the thermister and selects a parameter to be optimized from parameters related to a disk write operation. The controller writes arbitrary data to a test track on the disk to obtain a first bit error rate of the test track. The controller repeatedly writes arbitrary data to at least one track adjacent to the test track indicated by as many times as an adjacent track write count is based on an associated temperature measured by the thermister to obtain a second bit error rate of the test track. The controller sets a value of the selected parameter to determine a difference between the first bit error rate and the second bit error rate which is less than a predetermined criteria corresponding to an optimized value of the selected parameter in a disk zone to which the test track is located.08-21-2008
20080198491METHOD OF SETTING WRITE FACTOR IN HARD DISK DRIVE AND HARD DISK DRIVE USING THE SAME - A method of setting write factors of each head in a hard disk and a hard disk drive using the method. The method includes writing a write signal onto a test track based on a write factor initially set on the magnetic head, writing the write signals onto the tracks adjacent to the test track, measuring the write quality of the test track, changing the write factor of the magnetic head and repeating the writing of the write signal onto the test track, and setting a write factor of the magnetic head by selecting the write factor corresponding to an optimum write quality from among the write qualities of the write factors of the test track.08-21-2008
20080198490PRML channel with zero-mean noise reduction - A hard disk drive with a read channel that averages data before the data is provided to a viterbi detector of the channel. Averaging the data reduces the zero mean noise in the data.08-21-2008
20080198489Cartridge drive diagnostic tools - In one embodiment, a method of diagnosing an error in a cartridge drive, comprises detecting an occurrence of a defined event in a cartridge drive, in response to the defined event, initiating an analysis routine of at least one event log from the cartridge drive, and invoking an intervention routine when the analysis indicates that the defined event represents a failure threat.08-21-2008
20130148225SHINGLED MAGNETIC RECORDING (SMR) DISK DRIVE WITH VERIFICATION OF WRITTEN DATA - A “write-squeeze-verify” method is used for verification of the data that has been written in the annular bands of a shingled magnetic recording disk drive. The writing of data along a track overwrites a portion of the previously written track and thus “squeezes” the data of the previously written track to thereby form a “shingled data track” (SDT). The data in each SDT is read back and verified by performing an error correction check using error correction bits associated with the data written in the SDT, or by comparing the readback data with the data stored in memory. If the data read back is not verified, a write error counter is incremented and a write error frequency is calculated. One or more attempts to write the data can be performed. If the data in the SDT cannot be verified after the attempted rewrite(s), then a “re-try fail” is reported.06-13-2013
20100302662TESTING METHOD OF WAFER WITH THIN-FILM MAGNETIC HEADS AND MANUFACTURING METHOD OF THIN-FILM MAGNETIC HEAD - A testing method of a wafer provided with a plurality of thin-film magnetic heads is provided. Each of the plurality of thin-film magnetic heads includes a main pole layer, a first test pad formed on the wafer and electrically connected with an extended top end section of the main pole layer and a second test pad formed on the wafer and electrically connected with a back end section of the main pole layer. The testing method includes a step of measuring an electrical resistance between the first test pad and the second test pad, a step of judging whether the measured electrical resistance is within a set range, and a step of discriminating that the thin-film magnetic head is a non-defective product when the measured electrical resistance is within the set range.12-02-2010
20120275049ERROR BURST DETECTION AND AMELIORATION - A method according to one embodiment includes monitoring a data transfer operation for detecting temporary errors; determining whether an error burst has occurred based on the monitoring; if an error burst has occurred, altering a condition of the data transfer operation; monitoring the data transfer operation having the altered condition for detecting temporary errors; determining whether another error burst has occurred based on the monitoring of the data transfer operation having the altered condition; and if another error burst has occurred, altering another condition of the data transfer operation. Additional systems and methods are also presented.11-01-2012
20120275047Method of testing anti-high temperature performance of a magnetic head and apparatus thereof - A method of testing anti-high temperature performance of a magnetic head comprises applying a plurality of second magnetic fields with different intensities in a second direction to the magnetic head, and measuring a second output parameter curve, and judging whether a variation that is beyond an allowable value is presented on the second output parameter curve, therein the second direction passes through the ABS and at an angle whose absolute value is an acute angle to the ABS. The present invention can screen out defective magnetic heads that possess poor anti-high temperature performance without heating the magnetic head.11-01-2012
20130182346TAPE HEAD LENGTH ADJUSTMENT - A tape drive is disclosed. The tape drive determines a current tape width and adjusts the length of a tape head to more closely match the current tape width. The tape drive adjusts the length of the tape head by controlling the power to a heating element coupled to the tape head.07-18-2013
20120281304Systems and Methods for Read Head Characterization - Various embodiments of the present invention provide systems and methods for read sensor characterization. As an example, a data storage device is disclosed that includes a storage medium, a read/write head assembly disposed in relation to the storage medium, and a track width setting circuit. The track width setting circuit is operable to: write data to at least a first track and a second track on the storage medium, read data from the second track, determine an estimated track offset where interference from the data written to the first track is insubstantial, and modify at least the second track width based at least in part on the estimated track offset. The first track is a first track width and the second track is a second track width.11-08-2012
20120019945Method and system for measuring noise of a magnetic head - A method for measuring noise of a magnetic head includes setting a plurality of threshold values, applying bias current or voltage to a read element of the magnetic head, applying an external transverse magnetic field to the magnetic head, amplifying output signal from the read element to produce an amplified signal, filtering the amplified signal to produce a filtered signal, generating an enable signal for each threshold value in a predetermined time window by a counting control means with input signals which include the filtered signal and the threshold value, measuring the cumulative time duration of each enable signal, making an amplitude-duration distribution according to the cumulative time durations and the threshold values, calculating a plurality of parameters according to the amplitude-duration distribution and analyzing the parameters with a plurality of predetermined criteria to determine the defects of the magnetic head. Accordingly, the invention also discloses a system for measuring noise of a magnetic head.01-26-2012
20130194690MAGNETIC DISK APPARATUS AND DATA REFRESH METHOD - According to at least one embodiment, a magnetic disk apparatus includes a disk, a random number generator, a determination module, and a refresh module. The disk includes a plurality of tracks. A random number generator generates a random number within a range of N integers in accordance with writing to a first area of a first track of the plurality of tracks. A determination module determines whether the generated random number includes a predetermined number. A refresh module refreshes a second area of a second track near the first track based on a result of determination of the determination module. The second area corresponds to the first area.08-01-2013
20130194689MAGNETIC DISK APPARATUS, READ/WRITE CONTROL METHOD, AND CONTROLLER - According to at least one embodiment, a magnetic disk apparatus includes a magnetic disk, a nonvolatile memory, a determination module, a write module, and a read module. The determination module determines whether the off-track write occurs on a first data sector during a write mode. The write module writes first data in the nonvolatile memory if the determination module determines that the off-track write occurs on the first data sector. The read module reads the first data from one of the magnetic disk and the nonvolatile memory based on a determination result of the determination module.08-01-2013
20120033317POSITION ERROR SIGNAL DEMODULATION WITH TARGET-BASED BLENDING - In a disk drive, a method for servo burst-decoding demodulation that accommodates track pitch variation. Depending on the distance a read head is displaced from a read head target position, a target-based blending scheme, a position-based blending scheme, or a weighted combination of both is used to determine the position of the transducer head. When the transducer head is relatively close to the target position, the target-based blending scheme is used to decode servo bursts and calculate the exact head position. When the transducer head is relatively far from the target position, the position-based blending scheme is used to decode servo bursts and calculate head position. When the transducer head is an intermediate distance from the target position, a weighted combination of the target-based and position-based blending schemes is used.02-09-2012
20130201576STORAGE DEVICE HAVING CALIBRATION CIRCUITRY PROVIDING PROGRAMMABLE PHASE UPDATE VALUES - A hard disk drive or other disk-based storage device comprises a storage disk, a read/write head configured to read data from and write data to the disk, and control circuitry coupled to the read/write head and configured to process data received from and supplied to the read/write head. The control circuitry comprises calibration circuitry configured to vary a phase of a clock signal as a test pattern is written to the storage disk as part of a calibration procedure, and disk locked clock circuitry coupled to the calibration circuitry and configured to obtain phase lock between the clock signal and a timing pattern on a surface of the storage disk. The calibration circuitry is further configured to determine an initial phase update value to be applied by the disk locked clock circuitry in a control loop as the phase of the clock signal is varied as part of the calibration procedure.08-08-2013

Patent applications in class MONITORING OR TESTING THE PROGRESS OF RECORDING