Class / Patent application number | Description | Number of patent applications / Date published |
369530380 | Of transducer assembly mechanism | 33 |
20080232218 | Methods and apparatus to monitor and control hard-disk head position - Methods and apparatus to monitor and control hard-disk drive head position are described. In one example, a hard-disk drive system includes a hard-disk drive platter, a hard-disk drive read head configured to read information from the hard-disk drive platter, and a hard-disk drive head position controller configured to a receive a signal via the hard-disk drive read head and to determine if the received signal indicates that a distance between the hard-disk drive platter and the hard-disk drive is less than a predetermined distance and to vary a temperature of the read head based on the determination. | 09-25-2008 |
20100067342 | APPARATUS AND METHOD FOR ADJUSTING A FEED-FORWARD SIGNAL FOR SEEK CONTROL DURING A SEEK OPERATION - A hard disk drive control module has a feed-forward signal input port communicatively coupled with a reference model. The hard disk drive control module has a tracking error signal input port communicatively coupled with a magnetic transducer of the hard disk drive. The hard disk drive control module has an error calculator module configured for determining a difference between an estimated tracking error signal in response to a first feed-forward signal and an actual tracking error signal of the magnetic transducer in response to the first feed-forward signal. The hard disk drive control module has a feed-forward signal adjuster module configured for adjusting a gain and a phase for a second feed-forward signal based on the difference between the estimated tracking error signal in response to the first feed-forward signal and the actual tracking error signal of the magnetic transducer. The hard disk drive control module has a feed-forward signal adjustment output port communicatively coupled to the second feed-forward signal. | 03-18-2010 |
20100315928 | Elimination of errors due to aging in magneto-resistive devices - The problem of magneto-resistive sensor drift with age has been solved by normalizing the sensor's output relative to its output when it is in a selected reproducible state. Details for the method to accomplish this normalization are disclosed together with several examples of how the method can be utilized. | 12-16-2010 |
20110158072 | METHOD OF DETECTING APPROXIMATE TOUCH-DOWN, METHOD OF ADJUSTING HEAD FLYING HEIGHT USING THE DETECTED APPROXIMATE TOUCH-DOWN, AND DISK DRIVE - A method and apparatus to control a flying height of a head in a disk drive by detecting a flying state of the head just before it touches down to a disk. The method includes detecting approximate touch-down based on detecting a motion change of a head in a disk track direction by changing a flying height of the head on a rotating disk and determining that the head approaches a touch-down approximated flying height when the detected motion change of the head in the disk track direction exceeds a threshold value. | 06-30-2011 |
20110242954 | MAGNETIC HEAD SLIDER INSPECTION DEVICE - A magnetic head slider inspection device including a motor unit for revolving a disk medium, a slider unit provided with a reproducing head, which is levitated from a surface of the disk medium under force generated by the revolving disk medium, a magnetic field generator positioned at an opposite side of the disk medium with respect to the slider unit for generating a magnetic field substantially perpendicular to the disk medium surface, and a circuit unit for generating the magnetic field from the magnetic field generator, and measuring a resistance value of the reproducing head levitated from the disk medium surface. | 10-06-2011 |
20110255388 | PATTERN WRITING SYSTEM AND METHOD AND ABNORMALITY DIAGNOSING METHOD - Reflected and scattered electrons generated by emitting an electron beam onto a substrate are detected by a detecting unit. The product of the area (S | 10-20-2011 |
20120057446 | SUB-OPTICAL-RESOLUTION KERR SIGNAL DETECTION FOR PERPENDICULAR WRITE-HEAD CHARACTERIZATION - A property, such as a quality parameter, of a write pole in a write head is determined using an optical metrology device, where the write pole is smaller than the optical resolution limit of the metrology device. The metrology device produces polarized light that is reflected off the write pole while the write pole is magnetized either during or after excitation with a write current. The magnetization alters the polarization state of the light, which can be analyzed to transform the altered polarization state into intensity. The intensity of the light is detected over the point spread function of the optics in the metrology device and an intensity value is generated. The intensity value is used to determine the quality parameter of the write pole, e.g., by comparison to a threshold or reference intensity value, which may be generated empirically or theoretically. | 03-08-2012 |
20130058201 | APPARATUS FOR DIGITAL RMS DETECTION AND PEAK DETECTION IN HEAD-DISK CONTACT DETECTION - An apparatus comprises a root mean square (‘RMS’) value generator; an integrator coupled to the RMS value generator; a sample and hold switch coupled to an output of the integrator; a capacitor coupled between the sample and hold switch and a ground; an input of the analog to digital convertor (‘ADC’) coupled to the capacitor; an adder coupled to an output of the ADC; a register, wherein an output of the register is coupled to an input of the adder; and wherein an output of the adder is coupled to an input of the register; and a logic coupled to the register for comparing an output of the register to an RMS threshold value for determining whether a touch-down has occurred. | 03-07-2013 |
20130114387 | MEASURING METHOD OF A MAGNETIC HEAD AND MEASURING APPARATUS THEREOF - Measuring method of a magnetic head includes (a) placing the magnetic head at normal position, defining a first direction parallel to an air bearing surface and two shielding layers of the magnetic head, and defining a second direction perpendicular to the first direction; (b) tilting the magnetic head at an angle to the second direction, applying a plurality of first magnetic fields with different intensities in the first direction, and measuring out a first output parameter curve; (c) repeating the step (b) with different angles and measuring out a plurality of first output parameter curves; (d) calculating a plurality of pinned direction tilt ratios that a pinned direction of a pinned layer of the magnetic head tilts towards the second direction according to the parameter curves; and (e) calculating a pinned direction tilt angle that the pinned direction tilts towards the second direction according to the pinned direction tilting ratios. | 05-09-2013 |
20130242712 | STORAGE SYSTEM AND STORAGE CONTROL METHOD - A storage system includes plural drive devices and a control device. Each of the plural drive devices reads or writes data from or to a portable recording medium. The control device performs a parallel process in which a first process and a second process are performed in parallel. The first process is to write specified data to a first portable recording medium via a first drive device of the plural drive devices. The second process is to write the specified data to a second portable recording medium via a second drive device of the plural drive devices. The control device cancels, upon completion of either one of the first process and the second process, the other one of the first process and the second process. | 09-19-2013 |
20130294210 | SPECTRAL NOISE ANALYSIS FOR READ HEAD STRUCTURES - A testing device tests a magnetic head with a read head structure including a read head element while applying an external magnetic field to the magnetic head. The testing device receives signals from the read head element and processes the signals to generate a spectral power density for the signals. The spectral power density is characterized for at least one frequency range. The characterization of the spectral power density is used to determine a characteristic of noise from the read head structure. The signals from the read head may be received with different applied magnetic fields and/or before or while thermally exciting the magnetic head. Additionally, a histogram of the signals may be generated and used to determine a second characteristic of the noise. | 11-07-2013 |
20140029402 | Detection System Using Heating Element Temperature Oscillations - A data storage system includes a recording head and a compensating resistor. The recording head has a heating element. The compensating resistor is in electrical series with the heating element and is external to the recording head. A method includes applying an alternating current at a first angular frequency to a recording head. A voltage drop across the recording head heating element is measured. A component of the voltage drop is extracted. The component has a frequency that is three times the frequency of the first angular frequency. | 01-30-2014 |
20140086033 | METHOD AND APPARATUS FOR INSPECTING THERMAL ASSIST TYPE MAGNETIC HEAD DEVICE - In order to enable inspection of the physical shape of a near-field light emitting portion of a thermal assist type magnetic head, a thermal assist type magnetic head device is placed on a table movable in a plane, a probe fixed to a cantilever scans a plane apart at a constant distance from the surface of the sample placed on the table while moving the table in a plane, the displacement of the cantilever is detected by applying light to the scanning cantilever and detecting reflected light from the cantilever, an atomic force microscope (AFM) image of the thermal assist type magnetic head device is formed using information about the detected displacement of the cantilever and positional information about the table, and the quality of a physical shape including the size or typical dimensions of the near-field light emitting portion is determined by processing the formed AFM image. | 03-27-2014 |
20140092716 | METHOD AND APPARATUS FOR INSPECTING THERMAL ASSIST TYPE MAGNETIC HEAD - An apparatus for inspecting a thermal assist type magnetic head is configured to include a scanning probe microscope unit comprising a cantilever having a probe with a magnetic film formed on the surface of a tip portion thereof; a prober unit which provides an alternating current to a terminal formed on the thermal assist type magnetic head element; a scattered light detection unit which detects scattered light generated from the probe; and a signal process unit which detects defect by using an output signal from the scanning probe microscope unit by scanning the surface of the thermal assist type magnetic head element with the probe in a state that the magnetic field is generated and the near-field light is stopped, and an output signal from the scattered light detection unit by scanning the surface with the probe while near-field light is generated and the magnetic field is off. | 04-03-2014 |
20140092717 | METHOD AND APPARATUS FOR INSPECTING THERMAL ASSIST TYPE MAGNETIC HEAD - An apparatus for inspecting a thermal assist type magnetic head is constituted by a scanning probe microscope means including a cantilever having a probe with a magnetic film formed on the surface of a tip portion thereof; a probe unit which provides an alternating current to a terminal formed on the thermal assist type magnetic head element and causes a pulse drive current or pulse drive voltage; a scattered light detection means which scans the near-field light emitting part with the probe to detect the scattered light generated from the probe in the generation region of the near-field light; an imaging means which image the thermal assist type magnetic head element; and a signal process means inspects the thermal assist type magnetic head element and an output signal outputted from the scanning probe microscope means by scanning with the probe while providing an alternating current to the terminal. | 04-03-2014 |
20140133284 | MAGNETO-OPTICAL DETECTION OF A FIELD PRODUCED BY A SUB-RESOLUTION MAGNETIC STRUCTURE - A polarization microscope optically detects the effect of the magnetic field from a sub-optical resolution magnetic structure on a magneto-optical transducer. The magneto-optical transducer includes a magnetic layer with a magnetization that is changed by the magnetic field produced by the magnetic structure. The saturation field of the magnetic layer is sufficiently lower than the magnetic field produced by the magnetic structure that the area of magnetization change in the magnetic layer is optically resolvable by the polarization microscope. A probe may be used to provide a current to the sample to produce the magnetic field. By analyzing the optically detected magnetization, one or more characteristics of the sample may be determined. A magnetic recording storage layer may be deposited over the magnetic layer, where a magnetic field produced by the sample is written to the magnetic recording storage layer to effect the magnetization of the magnetic layer. | 05-15-2014 |
20140146649 | HEAD SUSPENSION FLEXURE WITH INTEGRATED STRAIN SENSOR AND SPUTTERED TRACES - Various embodiments concern a method for manufacturing a disk drive head suspension component. Such methods can comprise providing a head suspension component comprising a layer of insulating material on a spring metal layer. Such methods can further comprise forming a strain gauge element and a trace seed layer by depositing a first metal on the insulating material layer, such as by sputtering. The strain gauge element and the trace seed layer can be formed simultaneously by the depositing of the first metal as part of the same process step. The first metal can be of a strain gauge class of metal having relatively high resistivity, such as constantan. Such methods can further comprise plating a second metal on the trace seed layer to form one or more traces. | 05-29-2014 |
20140254341 | Friction Force Measurement Assembly and Method - The application discloses a sensor device to measure friction force at a head-media interface. As disclosed, the sensor device has a transducer element oriented to provide an electrical output responsive to force or strain imparted to the transducer element along an in-plane axis. Sensor circuitry is coupled to the transducer element to process the electrical output to provide an output measure of friction force. In illustrated embodiments, the head includes an actuator element which is powered on/off at an on/off frequency to cyclically protrude a localized portion of the head. The on/off frequency of the actuator is used by the sensor circuitry to detect excitation of the sensor device due to friction force at the head-media interface. | 09-11-2014 |
20140254342 | SPINSTAND WITH MOTOR HAVING FLUID DYNAMIC BEARING - Provided herein is an apparatus, including a spinstand configured to position a disk in a testing orientation and a motor coupled to the spinstand, configured to rotate the disk. The motor comprises a fluid dynamic bearing. | 09-11-2014 |
20140334278 | Systems and Methods for Energy Based Head Contact Detection - The present inventions are related to systems and methods for determining contact between two elements, and more particularly to systems and methods for determining contact between a head assembly and a storage medium. | 11-13-2014 |
20140334279 | TESTING METHOD OF A MAGNETIC HEAD, AND TESTING APPARATUS THEREOF - A testing method of a magnetic head includes: applying a first magnetic field with a constant intensity in a first direction that is the same with that of the longitudinal bias field to the magnetic head, simultaneously applying a second magnetic field with variant intensities in a second direction traversing the air bearing surface, and measuring a first noise; applying a third magnetic field with a constant intensity in a third direction that is opposite to the first direction to the magnetic head, simultaneously applying the second magnetic field with variant intensities in the second direction, and measuring a second noise; and analyzing noise change between the first noise and the second noise. The invention can screen out defective magnetic heads that possess poor noise characteristic and unstable performance. | 11-13-2014 |
20140334280 | Systems and Methods for Characterizing Head Contact - The present inventions are related to systems and methods for determining contact between two elements, and more particularly to systems and methods for determining contact between a head assembly and a storage medium. | 11-13-2014 |
20140347969 | Hard Disk Drive With Contact Detection Using a Spin Torque Oscillator - A hard-disk drive having a structurally efficient magnetic head slider utilizes a MAMR-based spin torque oscillator (STO) for head-disk contact detection and for flying height sensing. Contact detection and spacing estimation techniques consider the nominal temperature difference, and thus different criteria, between read and write operations. | 11-27-2014 |
20150023144 | METHOD 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. | 01-22-2015 |
20150085632 | DETECTION AND REMEDIATION OF HEAD CONTAMINATION - A heat generating component of a slider is energized at a predetermined frequency. The heat generating component changes a spacing between a medium and the slider. A temperature response proximate a media-facing surface of the slider is measured while the heating element is energized. Based on the measured temperature response, a determination is made as to whether the media-facing surface is contaminated. In response to determining that the media-facing surface is contaminated, remedial action is taken. | 03-26-2015 |
20150117173 | MODIFIED AREAL DENSITIES FOR DEGRADED STORAGE DEVICE READ HEADS - Systems, methods, and firmware for operating data storage devices and storage processors are provided herein. In one example, a data storage device is provided. The data storage device includes magnetic storage media configured to store data, read heads configured to read data from the magnetic storage media at associated areal densities, and a storage processor. The storage processor is configured to monitor read error rates of the read heads during operation of the data storage device to identify a degraded one of the read heads, and process at least the read error rates and an areal density of the degraded one of the read heads to modify the areal density of at least the degraded one of the read heads. | 04-30-2015 |
20160071540 | Diagnostic Method and Apparatus for a Tape Storage System - A diagnostic method and system comprising writing to a tape location of a tape medium using a first tape head as the tape medium is transported in a first direction, reading from the tape location using a second tape head as the tape medium is transported in the first direction, detecting an occurrence of a tape system failure, performing a diagnostic tape operation selected from a group consisting of writing to the tape location using the second tape head as the tape medium is transported in the first direction and reading from the tape location using the first tape head as the tape medium is transported in the first direction, differentially diagnosing a tape medium failure or a tape head failure depending on whether the tape operation failure is observed in response to performing the diagnostic tape operation, and posting a corresponding error code. | 03-10-2016 |
20160093320 | DETECTING DAMAGE TO TUNNELING MAGNETORESISTANCE SENSORS - Embodiments of the present invention provide methods, systems, and computer program products for detecting damage to tunneling magnetoresistance (TMR) sensors. In one embodiment, resistances of a TMR sensor are measured upon application of one or both of negative polarity bias current and positive polarity bias current at a plurality of current magnitudes. Resistances of the TMR sensor can then be analyzed with respect to current, voltage, voltage squared, and/or power, including analyses of changes to slopes calculated with these values and hysteresis-induced fluctuations, all of which can be used to detect damage to the TMR sensor. The present invention also describes methods to utilize the measured values of neighbor TMR sensors to distinguish normal versus damaged parts for head elements containing multiple TMR read elements. | 03-31-2016 |
20160379676 | HDD MAGNETIC HEAD DEGRADATION FIELD-FAILURE DETECTION AND PREDICTION - A method, apparatus, and system for implementing head degradation detection and prediction for hard disk drives (HDDs) are provided. Statistical parameter stability tests are used that are calculated as Confidence Intervals (CIs) from HDD parameter measurements. HDD parameters include, for example, change or delta in fly height (dFH), magnetic resistor resistance (MRR) head values, servo variable gain amplifier (SVGA) readback amplitude values, that are used in conjunction with two or more confidence level indicators and an Auto-Regressive Integrated Moving-Average (ARIMA) (p, d, q) predictor for head degradation detection and field failure prediction. | 12-29-2016 |
369530390 | Transducer location indicating | 4 |
20110242955 | PROXIMITY 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. | 10-06-2011 |
20120250484 | PROXIMITY SENSING SYSTEM - A data storage system for detecting a location of a head relative to a magnetic media is described. This system comprises arms, a preamplifier circuit coupled to the arms for controlling the arms, a proximity sensing system positioned within the preamplifier circuit, the proximity sensing system comprising: an input stage for transmitting an input sense signal; a programmable gain stage coupled to receive the input sense signal and operative for transmitting a gain signal in response to receiving the input sense signal; a multiplexer coupled to receive the gain signal and at least one control signal, the multiplexer operative for transmitting a multiplexed signal; a detector coupled to receive the multiplexed signal and a second control signal, the detector operative for transmitting an output signal; wherein an amplitude associated with the output signal enables detecting the location of the head. | 10-04-2012 |
20130250745 | Systems 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. | 09-26-2013 |
20140269241 | HIGH SAMPLE RATE DPES TO IMPROVE CONTACT DETECTION SIGNAL TO NOISE RATIO - Using a high sample rate dPES, together with pulsed heater and lock-in technique, to improve dPES SNR for contact detection between the head and media surface. Steps of powering a transducing head actuator with pulsed input signal at a select data track offset from a previously-written to data track of the storage medium, where the pulsed input signal has select amplitude and duty cycle to simulate a response signal, and further locking in an amplitude with respect to the heater frequency, can lead to a determination of level of heater power for initiating contact between the transducing head and the storage medium. | 09-18-2014 |