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Subclass of:

360 - Dynamic magnetic information storage or retrieval

360069000 - AUTOMATIC CONTROL OF A RECORDER MECHANISM

360075000 - Controlling the head

360770010 - Track centering

Patent class list (only not empty are listed)

Deeper subclasses:

Class / Patent application numberDescriptionNumber of patent applications / Date published
360770070 By tracking signal recorded on or immediately beneath surface 52
360770040 By memory storage of repeatable error or correction 31
360770050 By servo signal component from carrier surface separate from information signal bearing surface 17
360770030 By nonmagnetic sensing (e.g., optical, capacitive) 6
360770060 Reproduced data signal used for tracking 5
20090195916EXTRACTION OF TRANSDUCER POSITION INFORMATION FROM BIT PATTERNED MAGNETIC MEDIA - Extracting transducer position information from bit patterned magnetic media includes providing a magnetic storage medium having at least one data array with multiple discrete and separated recording bits and providing the transducer adjacent the data array. A readback signal dependent upon the multiple recording bits is generated with the transducer. Determining the transducer position information further includes generating at least a first position signal and a second position signal from the readback signal.08-06-2009
20080266706MAGNETIC HEAD AND DISK APPARATUS - A magnetic head having a recording head portion for recording information at an arbitrary position on a magnetic recording surface of a recording medium and also having a reproducing head portion containing a reproducing head element for reproducing the information recorded at the arbitrary position on the magnetic recording surface forms a reproducing head element, the shape of which is curved, being made after a curved shape of a magnetization pattern recorded at the arbitrary position of the recording medium. Due to the foregoing, a shape of the lead gap formed between the reproducing head element and the magnetic recording surface of the recording medium is made to substantially agree with the shape of the magnetization pattern. On the other hand, a disk apparatus having a reproducing head element is provided in which the shape of the lead gap is made to substantially agree with the shape of the magnetization pattern.10-30-2008
20110032637EMBEDDED TRACK INFORMATION FOR PATTERNED MEDIA - A bit-patterned magnetic media (BPM) includes with respect to each data track a first sub-track and a second sub-track, each sub-track comprised of a plurality of bit-islands. A transducer head placed over a data track generates a readback signal. Channel response circuitry demodulates the readback signal and detects fine positioning information based on a comparison of a readback signal generated in response to the first sub-track and a readback signal generated in response to the second sub-track.02-10-2011
20080198502WRITE-HEAD POSITIONING METHOD AND DISK DRIVE - A write-head positioning method includes steps of positioning a write head on a first track of a storage medium on the basis of a servo signal and writing a signal on the first track, positioning the write head on second and third tracks located adjacent to opposite sides of the first track on the basis of servo signals and writing signals on the second track and the third track, positioning the read head at positions on the first track that are set at a predetermined interval in a track-width direction, and reading a signal from the first track at each position thereof, determining a signal profile that indicates a fluctuation of output values of the signals read at the respective positions on the first track, and detecting a peak position indicating a maximum output value in the determined signal profile.08-21-2008
20080198501Storage apparatus, storage control circuit, and head-position-displacement measuring method - Magnetic disks have a configuration in which a plurality of tracks formed of a magnetic substance are sectioned by a non-magnetic substance that does not allow magnetic write heads are of a combined type of a read head and a write head. A measurement recording unit causes the head to move across a predetermined amount at least more than one track during one lap of track, with a predetermined radial position and a track position of the magnetic disk being taken as recording start points, thereby writing measurement data while drawing a spiral path. A measurement reading unit causes the measurement data recorded in a spiral manner to be read while gradually shifting a read-beginning point within a predetermined scanning range from an inner perimeter side including the recording start points to an outer perimeter side. A position-displacement detecting unit finds a distribution of amplitudes of a read-back signal within a read scanning range and detects, in a distribution of evaluation values, an amount of position displacement of a read head and a write head on the storage medium in a radial direction for storage.08-21-2008
Entries
DocumentTitleDate
20100020435RECORDING DEVICE WITH WRITE HEAD SPANNING MULTIPLE ROWS OF BIT CELLS AND MULTI-SENSOR READ HEAD - In a recording device, a bit patterned medium comprises a track of bit cells, each settable to one of two distinct bit states. The track comprises two generally parallel rows of bit cells. The bit cells in one row are offset in a down track direction from the bit cells in the other row. A write head spans the two rows. A controller synchronously applies write signals to the write head to set the trailing bit cell covered by the write head as the track moves relative to the write head, and thereby write data to the track. The trailing bit cell covered by the write head alternates from being in one row to being in another row. Read sensors are positioned to independently read bit cells in respective rows, as the track moves relative to the write head along the down track direction.01-28-2010
20100149683MAGNETIC DISK DRIVE AND WRITE OFFSET CORRECTION METHOD THEREIN - According to one embodiment, a magnetic disk drive uses a patterned medium on which data tracks having a recording layer and grooves having no recording layer as a disk. The magnetic disk drive includes a correction unit which corrects the head center position of a write head so that a head edge portion on the side to which the top edge of the write head is tilted falls within or substantially falls within a groove on the side to which the top edge of the write head is tilted.06-17-2010
20100079903ADAPTIVE DATA RECOVERY PROCEDURE BASED ON RADIAL POSITIONING - Data recovery information characterizes data recovery procedure (DRP) steps to be performed within a hard disk drive (HDD) in response to a miss. Particular data recovery information corresponds to a radial position of the actuator and, therefore, the position of the magnetic recording read/write head relative to the associated storage media at the location at which the miss occurred. The data recovery information is based on the physical shape of a write pole and on how the physical shape of the pole inherently affects operational data error associated with the head. Because of the foregoing characteristics of such data recovery information, a more efficient and performant data recovery procedure is performed based thereon.04-01-2010
20090122439Mitigating the effects of disturbances of a disk drive - Embodiments of mitigating the effects of disturbances of a disk drive are disclosed. One method includes sensing a position error signal of a transducer coupled to a surface of the disk drive, wherein the position error signal aids in control of an actuator of the disk drive. A first disturbance signal is generated by sensing a disturbance of a first sensor attached to the disk drive, wherein the first disturbance signal aids in control of the actuator. A second disturbance signal is generated by sensing a disturbance of a second sensor attached to the disk drive, wherein the second disturbance signal aids in control of the actuator. Effects of the disturbances on the position error signal are reduced by adaptively adjusting a gain of the first disturbance signal and a gain of the second disturbance signal.05-14-2009
20100073809X-AMR ASSISTED RECORDING ON HIGH DENSITY BPM MEDIA - A method of writing information to an area of a bit-patterned medium, in which a magnetized probe generates a magnetic probe field at the area of bit-patterned medium to be written, applying an oriented static magnetic field, and applying an oriented microwave field at a selected frequency, resulting in the writing of information onto the area of bit-patterned media.03-25-2010
20100073808POSITION SENSING IN DISCRETE TRACK RECORDING - In a particular embodiment, a storage system is disclosed that includes a discrete track media having a plurality of concentric data tracks to store data and including a respective plurality of non-magnetic regions to separate adjacent data tracks. The non-magnetic regions include encoded position information. The storage system further includes a controller adapted to adjust a position of a read/write head relative to a center of a particular track based on the encoded position information.03-25-2010
20120182643Systems and Methods for Reduced Format Data Processing - Various embodiments of the present invention provide systems and methods for data processing. For example, some embodiments of the present invention provide data processing circuits that include a variable gain amplifier circuit, an analog to digital conversion circuit, a cosine component calculation circuit, a sine calculation circuit, and a zero gain start calculation circuit. The variable gain amplifier circuit is operable to apply a gain to a data input corresponding to a gain feedback value and providing an amplified output. The analog to digital conversion circuit is operable to convert the amplified output to a corresponding series of digital samples. The cosine component calculation circuit is operable to calculate a cosine component from the series of digital samples, and the sine component calculation circuit operable to calculate a sine component from the series of digital samples. The zero gain start calculation circuit is operable to calculate a raw gain error value based on the cosine component and the sine component, where the gain feedback value is derived from the raw gain error value.07-19-2012
20090268338DATA STORAGE DISK HAVING VARIABLE LOCATION SIGNAL AND DISK DRIVE USING THE DATA STORATE DISK - A hard disk drive includes a magnetic head, at least one disk and a controller. A location signal is recorded on the at least one disk for determining a location of the magnetic head in relation to the at least one disk. The controller controls the location of the magnetic head based on the location signal decoded through the magnetic head. At least one of frequency and amplitude of the location signal is variable.10-29-2009
20090268337METHOD AND APPARATUS FOR DETERMINING OFFSET BETWEEN READ HEAD AND WRITE HEAD IN A DISK DRIVE - According to one embodiment, a disk drive is disclosed which has an offset measuring function for measuring a dynamic offset value necessary to a dynamic offset control using a DTM type disk. A CPU included in the disk drive writes offset measuring position information to an optimum position of lands on the disk and calculates a dynamic offset value based on the offset measuring position information.10-29-2009
20100214687STORAGE DEVICE AND READ/WRITE PROCESSING METHOD THEREFOR - According to one embodiment, a storage device includes: a control circuit configured to perform a write retry when data writing fails, wherein the control circuit recognizes that read commands are issued at regular intervals for reproducing continuous pieces of data, and upon detecting an error requiring the write retry to be performed in the data writing by a write command received during the reproduction, the control circuit interrupts the data writing, perform data reading to store the data in the buffer memory after allocating a storage area for the data in the buffer memory, and then resumes the data writing.08-26-2010
20110292541DISK-ENCLOSURE COVER FOR LOW-PROFILE, HARD-DISK DRIVE - A disk-enclosure cover for a low-profile, hard-disk drive (HDD). The disk-enclosure cover includes a substantially flat, plate-like portion that includes a periphery, and a peripheral flange that is disposed at the periphery. The peripheral flange includes a recessed portion that is configured to be recessed from a SATA connector in proximity to the SATA connector. In addition, the recessed portion is configured to allow a top portion of the SATA connector to be disposed in close proximity to the peripheral flange when the SATA connector is seated on a receiving connector of the low-profile HDD.12-01-2011
20080285170Magnetic disk drive and method of controlling the same - Embodiments of the present invention provide a magnetic disk drive, in which a disturbance component contained in an output signal from a rotational vibration detector, can be appropriately suppressed irrespective of frequency of the component, and a method of controlling the drive. According to one embodiment, in a magnetic disk drive having a rotational vibration detector for detecting rotational vibration of a drive housing, a main control circuit performs a head moving step of driving a voice coil motor to move a magnetic head on a magnetic disk, a frequency estimation step of estimating a frequency of each disturbance component contained in an output signal from the rotational vibration detector after moving the magnetic head, and a suppressor setting step of setting a notch filter for suppressing the disturbance component based on the estimated frequency.11-20-2008
20090310249WRITE-ONCE TYPE STORAGE APPARATUS, CONTROL CIRCUIT, AND CONTROL METHOD - A recording processing unit sets a track pitch narrower than a writing width of a recording element so that part of the recorded track overlapped with the unused track is overwritten, and continuously records information on a disk medium toward one direction in accordance with the track pitch. A first offset correcting unit reads a write/read offset from a storage table, in which the write/read offset is measured and saved in advance, and corrects the write/read offset in the state that a reading element is positioned at a target track. A second offset correcting unit corrects a write-once center offset, which is a positional deviation between a read center position of the reading element, which has undergone correction of the write/read offset by the first offset correcting unit, and a center position of an effective track width caused by write-once recording.12-17-2009
20100195244SERVO AREA TEST METHOD OF A MAGNETIC RECORDING MEDIUM AND A TEST DEVICE - A read signal for one revolution of each of a plurality of tracks jitter of which is cancelled is obtained and a binary-coded image data for the read signal is generated and the track number position of each servo area is specified from the binary-coded image data. Further, a read signal in this position in radial direction is obtained from the track number position of each of the specified servo areas and the servo area is tested by the read signal.08-05-2010
20090168223Servo track writer clockhead radius jig - A servo track writer (STW) clockhead radius jig is disclosed. One embodiment provides a hard disk drive assembly including a base having a cutaway portion to provide visual access therein. In addition, a disk is mounted in the hard disk drive assembly, this disk having an indicator thereon to indicate a required radius setting for a clockhead.07-02-2009
20090103204BIT PATTERNED MEDIUM HAVING SUPER-TRACK, METHOD OF TRACKING TRACK OF BIT PATTERNED MEDIUM, HEAD APPROPRIATE FOR BIT PATTERNED MEDIUM, AND INFORMATION RECORDING/REPRODUCING APPARATUS INCLUDING BIT PATTERNED MEDIUM HEAD - Provided are a bit patterned medium having a super-track, a method of tracking a track of the bit patterned medium, a head appropriate for the bit patterned medium, and an information recording/reproducing apparatus including the bit patterned medium and the head. The bit patterned medium includes a substrate, and a recording layer comprised of a plurality of bit cells which are formed on the substrate by being separated from each other, along a plurality of tracks. Each of the plurality of tracks includes a super-track comprised of a plurality of sub-tracks. Bit cells formed on a sub-track from among the plurality of sub-tracks in the super-track are disposed so as to deviate from bit cells formed on another sub-track from among the plurality of sub-tracks in the super-track. A track ID (identification) for recognizing the super-track, and a servo burst generating a position error signal when a head tracks the super-track, are arranged in an area of each of the plurality of tracks. Meanwhile, the head includes a writing head recording information in units of sub-tracks, and a reading sensor reproducing the information in units of super-tracks.04-23-2009
20080239554Disk drive device and method for production thereof - Embodiments of the present invention provide a magnetic disk device and a method for production thereof, the magnetic disk device being characterized in that the magnetic disk therein permits a plurality of tracks thereon to record correction data when necessary without decreasing its storage capacity. According to one embodiment, the magnetic disk device is characterized in that the magnetic disk has the first tracks and the second tracks formed thereon, the first tracks having servo data regions arranged cyclically, with a portion of a region between them being the correction data region and the remaining regions being the user data region, and the second tracks having the servo data regions arranged cyclically, with the region between them being the user data regions, and the multiprocessing unit (MPU) switches the servo extraction timing of the position information sampler depending on whether the track for servo reproduction by the magnetic head is the first track or the second track.10-02-2008
20090168224METHOD AND APPARATUS FOR OFFSET CONTROL IN A DISK DRIVE - According to one embodiment, there is provided a disk drive that can perform dynamic offset control (DOC). The disk drive has a magnetic head, a disk, and offset calculating modules. The magnetic head has read head. Offset-measuring position data is written in a non-servo area provided in the disk. The read head reads the offset-measuring position data from the disk. Based on the offset-measuring position data thus read, the offset calculating modules calculate an offset value that changes during a one-rotation period of the disk.07-02-2009
20090168222Correcting a track pitch error with a subsequent servo-write pass - A method for correcting a track pitch error in servo tracks written on a magnetic recording media coupled with a disk surface, by using a subsequent servo-write pass, comprises propagating servo tracks across the magnetic recording media in a previous servo-write pass. The servo tracks have radial positioning servo code. The servo tracks enable a magnetic transducer to be positioned to at least one radial position on the magnetic recording media. At least one corrected radial reference point is calculated for the track pitch error written on the magnetic recording media, by identifying at least one inconsistency between a mechanical response of an actuator and the track pitch. A corrected location for at least one servo track is identified. At least one new servo track at the corrected location is propagated with the subsequent servo-write pass. Optimum data track distribution across the disk surface and optimum reading and writing of data to and from the magnetic recording media is enabled.07-02-2009
20090168225DISK DRIVE DEVICE AND HEAD POSITIONING CONTROL METHOD - According to one embodiment, a disk drive includes a detection signal producing module configured to produce a detection signal by reading each of the spiral servo patterns, the spiral servo patterns being read by a head while the head scans a circumferential direction region on the disk media. A position error computation module is configured to produce servo burst signals A, B, C, and D using a plurality of frames obtained by dividing the detection signal at even time intervals, at least one burst signal of the servo burst signals being produced using at least two frames in the frames, and to compute a position error of the head based on amplitude values of the produced burst signals.07-02-2009
20080291567Post-assembly head/disk offset adjuster - A post-assembly head/disk offset adjuster is disclosed. One embodiment provides a housing and at least one disk coupled with the housing. In addition, an adjustable pivot plate is coupled with the housing such that access to at least one adjustment point of the adjustable pivot plate is provided regardless of a state of assembly of the hard disk drive. Furthermore, an actuator is coupled with the adjustable pivot plate. In so doing, an adjustment to the at least one adjustment point of the adjustable pivot plate results in an adjustment to the actuator regardless of the state of assembly of the hard disk drive.11-27-2008
20100142084MAGNETIC MEDIUM HAVING AN ARTIFICIAL PATTERN STRUCTURE USING A GRADIENT OF A MAGNETIZATION REVERSAL FIELD AND A METHOD OF USE THEREOF - To avoid the occurrence of a recording error by suppressing the influence that a magneto-static interaction acting between the pattern dots exerts on a recording process and expand a margin for recording synchronization timing lag or tracking misregistration on the pattern dot. Each pattern dot has a structure in which a plurality of parts having different magnetization reversal fields are bonded with exchange interaction in the in-plane direction of a medium, substrate. The positional relationship between the parts having different magnetization reversal Fields is substantially coincident between the adjacent pattern dots, which are arranged to have a gradient of magnetization reversal field in a track direction or track transverse direction. Further, the recording is performed by adapting a gradient of recording magnetic field to the gradient of magnetization reversal field. Other methods and systems are described as well.06-10-2010
20120069465SPIN TORQUE OSCILLATOR AND MAGNETIC RECORDING HEAD AND MAGNETIC RECORDING DEVICE MOUNTED WITH THE SPIN TORQUE OSCILLATOR - The present invention provides a spin torque oscillator that can realize stable oscillation and has high reliability. A laminated structure including a first magnetic layer 03-22-2012
20110141617METHOD AND APPARATUS FOR MEASURING DISK RUNOUT IN A DISK DRIVE - According to one embodiment, a disk drive includes an actuator, a servo controller, a calculation module and an adjustment module. The actuator is configured to move the head over a disk, in the radial direction of the disk. The servo controller is configured to make the head move along a target orbit on the disk, in accordance with the distance the actuator has been moved. The calculation module is configured to calculate, as disk runout, a virtual target orbit value supplied to the servo controller to suppress the disturbance at the target orbit. The adjustment module is configured to multiply the virtual target orbit value by a gain that has been preset.06-16-2011
20090086363TRANSDUCER POSITIONING RESPONSIVE TO COMPLEX POSITION ERROR SIGNAL - Positioning of a transducer is controlled in response to real and imaginary component signals that are formed from a position error signal (PES) which is indicative of the transducer location on a media.04-02-2009
20090201602LONG-TERM ASYMMETRY TRACKING IN MAGNETIC RECORDING DEVICES - A technique tracks head asymmetry of a magnetic recording device over time. In particular, a reference pattern having a known fundamental/reference frequency may be read from a reserved track of a magnetic recording medium to produce a response signal, and signal power may then be determined at the reference frequency and at a second harmonic component frequency of the reference frequency. Accordingly, head asymmetry for the device may be tracked based on a ratio of the signal power at the second harmonic component frequency to the signal power at the reference frequency.08-13-2009
20090244767CONTROLLER FOR A POSITIONING DEVICE, METHOD FOR CONTROLLING A POSITIONING DEVICE, POSITIONING DEVICE, AND LITHOGRAPHIC APPARATUS PROVIDED WITH A POSITIONING DEVICE - A controller for a positioning device is constructed and arranged to receive a position signal indicative of a position of the positioning device, compare the position signal to a set-point signal indicative of a desired position of the positioning device to obtain an error signal, selectively modify the error signal based on the amplitude and the frequency content of the error signal to obtain a modified error signal, generate a control signal for controlling the positioning device on the basis of the modified error signal. The controller may be applied to control a positioning device in a lithographic apparatus.10-01-2009
20100020434METHOD FOR PRODUCTION OF MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCTION DEVICE - A method for the production of a magnetic recording medium includes the steps of forming a magnetic layer on a nonmagnetic substrate, injecting atoms into portions of the magnetic layer to cause the portions to be demagnetized or allowed to acquire amorphousness, thereby forming a magnetically separated magnetic recording pattern, the step of injecting atoms including the steps of applying to a surface of the formed magnetic layer an SOG film as a resist, partly removing or thinning the resist, and irradiating the surface with atoms, thereby partly injecting atoms into the magnetic layer through the portions of the magnetic layer from which the resist is removed or in which the resist is thinned.01-28-2010
20100220409MAGNETIC STORAGE MEDIUM, INFORMATION STORAGE DEVICE, AND CONTROL DEVICE - According to one embodiment, a magnetic storage medium, includes a magnetic recording layer that includes: a servo area including predetermined servo information; a user data area including predetermined user information; two preamble areas including a plurality of magnetic bodies made of magnetic particles, the magnetic bodies being arranged in a staggered pattern so that the staggered pattern is inverted with respect to an axis of symmetry at a track center; and a re-sync mark area positioned at a head of the preamble areas and indicates a start of the preamble areas.09-02-2010
20090073599Perpendicular magnetic recording medium and magnetic recording and reproducing apparatus using the same - Embodiments of the present invention provide a perpendicular magnetic recording medium suitable for high density recording. According to one embodiment, a magnetic recording layer comprises four layers in which a first magnetic layer, a magnetic coupling layer, a second magnetic layer, and a third magnetic layer are formed above a substrate. The first magnetic layer and the second magnetic layer are perpendicular magnetization films containing an oxide, and ferromagnetically coupled with each other by way of the magnetic coupling layer, and they are, more preferably, a Co alloy layer containing an oxide. The third magnetic layer is ferromagnetically coupled with the second magnetic layer. The concentration of the oxide contained in the third magnetic layer is lower than the concentration of the oxide in the second recording layer, or the third magnetic layer does not contain the oxide. In this case, magnetic property is set for the anisotropic magnetic field Hk1 of the first magnetic layer and the anisotropic magnetic field Hk2 of the second magnetic layer, so as to satisfy: Hk1>Hk2.03-19-2009
20100302675STORAGE MEDIUM AND METHOD AND PROGRAM FOR DETECTING TRACK POSITION OF STORAGE MEDIUM - According to one embodiment, a storage medium that stores position information indicating positions of a plurality of tracks in a radial direction in the tracks, wherein the position information includes: a first pattern in which a feed angle indicating a phase difference between the tracks is an angle obtained by adding a predetermined angle to +90°; a second pattern in which the feed angle is an angle obtained by adding the predetermined angle to −90°; and a third pattern in which the feed angle is the same as that of the first pattern.12-02-2010
20100134917METHOD AND APPARATUS FOR OFFSET CONTROL IN A DISK DRIVE - According to one embodiment, a disk drive capable of performing a dynamic offset control (DOC) is provided. The disk drive has an offset module and an updating module. The offset module calculates an offset value that changes during a one-rotation period of a disk, from the offset-measuring position data recorded in the disk. The updating module updates the offset value to a new one if a disk shift has occurred.06-03-2010
20090207521TECHNIQUES FOR IMPROVING PARALLEL SCAN OPERATIONS - Various technologies and techniques are disclosed for improving performance of parallel scans. Disk head randomization that occurs when performing a parallel scan is minimized by assigning a worker entity to each disk involved in the parallel scan, and by ensuring data is only accessed on a respective disk by the worker entity assigned to the disk. A parallel scan can be performed that is NUMA aware by ensuring a particular sub-set of data is resident in the same memory node during each parallel scan, and by ensuring the particular sub-set of data is processed by a worker entity assigned to a node in which the sub-set of data is resident. A process for performing a parallel scan involves breaking up work into sub-sets, assigning work to each worker entity that corresponds to a respective disk, and having the worker entities process the assigned work to complete the parallel scan.08-20-2009
20080218896HEAD POSITION CONTROL DEVICE AND MEDIUM STORAGE DEVICE - A head position control device uses a current observer control which performs two degree of freedom control, with which a current step difference due to the difference of eccentricities between heads is prevented without affecting the seek waveform after switching heads. The head position control device has a locus generation section, which calculates an initial value of the correction locus for canceling the current step difference of the output current based on an output current supplied to an actuator before switching, and an eccentricity correction current and initial velocity of another head after switching; and a two degree of freedom control system to which a seek locus is input, and supplies a correction locus according to the initial value to the two degree of freedom control system. One parameter can correct the initial velocity and the current step difference.09-11-2008
20110188154MAGNETIC DISK DEVICE AND CONTROL METHOD THEREOF, AND INFORMATION PROCESSOR - According to one embodiment, a magnetic disk device is configured to read data from and write data to a magnetic disk using a magnetic head and provided with a control module that controls initial operation of the magnetic disk device according to initial firmware. The magnetic disk device includes a reader, a retainer, a blocker, and a switch. The reader reads control firmware stored in the magnetic disk. The retainer fixes a servo control amount for the magnetic head after the control firmware is read, and retains the magnetic head at a predetermined position above the magnetic disk. The blocker blocks input of an interrupt signal to the control module. The switch switches the initial firmware to the control firmware after the servo control amount is fixed and the input of an interrupt signal is blocked.08-04-2011
20100027158Magnetic head for high-frequency field assist recording and magnetic recording apparatus using magnetic head for high-frequency field assist recording - A magnetic recording head includes: a magnetic pole; a magnetic shield forming a magnetic circuit with the magnetic pole; and a spin torque oscillator provided between the magnetic pole and the magnetic shield, and formed with a stack structure including a first magnetic layer, a second magnetic layer, and an intermediate layer interposed between the first magnetic layer and the second magnetic layer. The first magnetic layer is made of a magnetic material of 200 Oe or smaller in coercive force. A cross-sectional area of the first magnetic layer in a direction perpendicular to a stack layer face of the first magnetic layer is four or more times greater than a cross-sectional area of the second magnetic layer in a direction perpendicular to a stack layer face of the second magnetic layer.02-04-2010
20120300341INFORMATION RECORDER AND INFORMATION RECORDING METHOD - According to one embodiment, an information recorder includes: a determination module; a storage module; a reader; and a writer. The determination module determines whether a position of a head for writing data is off a target track of a recording medium. The storage module temporarily stores therein data written by the head. The reader reads, if it is determined that the head is positioned off the target track, first data written in a sector which is considered overwritten by the head positioned off the target track among sectors of an adjacent track adjacent to the target track, from the storage module. The writer writes, if it is determined that the head is positioned off the target track, the first data into a sector positioned later than the sector into which data is written at the time the head is positioned off the target track.11-29-2012
20100271731UNEQUAL ZONING FOR TRACK FOLLOWING ON A HARD DISK DRIVE - Unequal zoning for track following on a hard disk drive comprising at least one magnetic disk, a read/write head connected to at least one actuator arm and capable of reading and writing data on said at least one magnetic disk, a controller capable of moving said at least one actuator arm. A track is followed using the read/write head on the surface of the at least one magnetic disk. Information is stored at the controller regarding off-track displacement of the read/write head. A plurality of unequal zone partitions is created, wherein an unequal zone partition of the plurality of unequal zone partitions represents a physical region of the at least one magnetic disk and wherein the plurality of unequal zone partitions are based on the information regarding the off-track displacement of the track and are used by the controller to compensate for the off-track displacement of the track.10-28-2010
20100007985METHOD FOR PRODUCING MAGNETIC MEDIUM, MAGNETIC RECORD REPRODUCTION DEVICE, AND MAGNETIC RECORDING MEDIUM - One object of the present invention is to provide a method for producing a magnetic recording medium which has excellent magnetic separation properties of the magnetic recording pattern, the present invention providing a method for producing a magnetic recording medium having a magnetic recording pattern which is magnetically separated, comprising the steps of: after laminating at least a magnetic layer and a carbon protective layer on a non-magnetic substrate in this order, partially irradiating with a reactive plasma containing carbon and a halogen or reactive ions which are generated in the reactive plasma on a surface of the carbon protective layer, and thereby forming a halogenated carbon protective layer, which is obtained by partially halogenating the carbon protective layer, and the magnetic recording pattern separated magnetically which is obtained by partially improving the magnetic layer.01-14-2010
20080297942Drive unit - Embodiments in accordance with the present invention provide a drive unit that is capable of satisfactorily performing the positioning control with disturbance components included in a position error signal being effectively controlled. According to one embodiment, an error signal generator of a drive unit generates a position error signal (PES) on the basis of servo data read out from a magnetic disk. On the assumption that a frequency of a periodic variation component included in the PES is a target frequency, if a target frequency deviates from an effective frequency range of a digital filter, a downsampler down-samples the PES, and then supplies the PES to the digital filter so that the effective frequency range is shifted. As a result, within the shifted effective frequency range, a setting changing unit can control a setting frequency of the digital filter so that the setting frequency follows the target frequency. Therefore, it is possible to effectively reduce a signal component of the target frequency (a periodic variation component included in the PES).12-04-2008
20100232056METHOD FOR MANUFACTURING MAGNETIC RECORDING MEDIUM, AND MAGNETIC RECORDING/REPRODUCING DEVICE - Provided is a process for manufacturing a magnetic recording medium having a magnetically partitioned magnetic recording patterns, which comprises the following steps, conducted in the order: (1) step of forming a magnetic layer on a non-magnetic substrate, (2) step of exposing the surface of regions of the magnetic layer to a reactive plasma or a reactive ion, which regions are to magnetically partition the magnetic layer for forming a magnetically partitioned magnetic recording pattern, and (3) step of exposing the magnetically partitioned magnetic layer to an inert gas irradiation. Preferably, a step of removing surface layer portions of said regions of the magnetic layer is carried out after the step (1) but before the step (2). The surface of the magnetic layer of produced magnetic recording medium exhibits good resistance to corrosion caused by oxidation or halogenation.09-16-2010
20120327533DISK DRIVE MAPPING OUT DATA TRACKS TO AVOID THERMAL ASPERITIES - A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, wherein the head comprises a write element and a read element. An asperity in a target data track is detected, and a range of data tracks proximate the target data track is mapped out, wherein the range of data tracks spans at least twice a radial offset between the read element and the write element at the radial location of the target data track.12-27-2012
20100214686HEAD POSITIONING METHOD FOR ECCENTRIC TRACK AND HEAD POSITIONING CONTROL DEVICE - Drive waveforms with which extension and contraction characteristics of an actuator corresponding to a number of track eccentricity amounts are stored as data. By reading servo information written in a disk is obtained as a signal indicating a head displacement amount from a track. The head is moved in a direction in which the track is displaced by obtaining an amplitude corresponding to a slip amount of the head position and a rotation angle of maximum eccentricity, reading drive waveforms which is optimal in driving the actuator from the memory and driving the actuator with a drive waveform matched with the rotation angle at which the eccentricity is maximum.08-26-2010
20080198500Interleaved servo pattern - In general, the invention is directed to servo techniques that utilize servo patterns to facilitate head positioning relative to the data tracks. For example, the servo techniques may include a first series of servo patterns configured to allow calculation of a position error signal that substantially mitigates error resulting from a variation in velocity of the data storage tape during detection of the at least one of the servo patterns in the first series. The servo techniques may also include a second series of servo patterns interleaved within the first series of servo patterns in order to encode data. The encoded data may include linear position information. Embodiments may allow a data storage tape meeting a currently accepted data storage tape specification, e.g., an LTO Ultrium specification, to record data in a higher density than currently implemented with the specification.08-21-2008
20120281310DETERMINING MICROACTUATOR FAILURE IN A MULTI-STAGE TRACKING SYSTEM - A multi-stage tracking control system includes at least a main actuator and a microactuator. The tracking control system is switched to a single-stage mode so that the main actuator alone provides tracking. A disturbance signal is applied to the microactuator while in the single-stage mode, and a failure condition of the microactuator is determined based on a position error generated in response to the disturbance signal.11-08-2012
20110310506MAGNETIC DISK DEVICE AND HEAD POSITION CONTROL METHOD - According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, a position error signal output module, a vibration pattern detector, an adder, and a head positioning controller. The magnetic head moves over the magnetic disk. The position error signal output module outputs a position error signal based on a difference between a head position of the magnetic head over the magnetic disk and a target position on the magnetic disk. The vibration pattern detector detects a vibration pattern of the magnetic head caused by vibration. The adder adds the position error signal to an offset signal indicating amplitude of the vibration pattern. The head positioning controller moves the head position to the target position based on a result of addition by the adder.12-22-2011
20120019957METHOD 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.01-26-2012

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