Abstract: A hard disk drive (HDD) including a slider. The slider includes a resistive temperature detector (RTD) configured to detect a temperature generated by one or more of slider spacing and contact with a media of said HDD. HDD also includes a slider signal controller configured to control bias signal of a slider with respect to a media potential, a real-time media-disk fly-height and contact detector configured to detect one or more of temperature generated by real-time media-disk slider spacing and real-time media-disk contact, and a real-time relative fly-height determiner configured to detect real-time relative fly-height of the slider based on analysis of a modulated portion of a high-frequency signal coupled to an element of the slider.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method for measuring a change of a clearance between a head and a disk. The method includes reading a preliminarily written data string for clearance measurement on a disk to obtain a first measured value corresponding to a clearance, and writing a new data string for deterioration check onto the disk and reading the data string for deterioration check to obtain a second measured value corresponding to the clearance. The method also includes determining a deterioration of the data string for clearance measurement from a difference between the first measured value and the second measured value, measuring a clearance change using the data string for clearance measurement by a normal operation if the determination is that the data string for clearance measurement has not deteriorated, and measuring a clearance change by an operation different operation if the determination is that the data string for clearance measurement has deteriorated.

Abstract: Various embodiments for addressing time-varying periodic disturbances in a servo control system are provided. Each of a plurality of coefficients is updated based on an estimation of at least one disturbance frequency. The updated plurality of coefficients is provided to at least one peak filter modifying an input signal of the servo control system. The peak filter is operable in view of the updated plurality of coefficients to cancel at least one of the time-varying periodic disturbances.

Abstract: A method of detecting defects of a recording medium comprises detecting a number of error-corrected error correction code symbols in each of a plurality of sectors in the recording medium, classifying sectors having a number of error-corrected ECC symbols greater than a first threshold value as first type defect sectors, calculating moving averages of the numbers of error-corrected ECC symbols in units of a predetermined number of sectors, and classifying sectors that are used to calculate a moving average greater than a second threshold value as second type defect sectors.

Abstract: The present invention provides an optical information recording apparatus and method capable of effectively determining appropriate recording parameters in a short time with favorable efficiency, when recording information onto an optical disk having different information recording conditions and information recording characteristics. An information recording condition or an information recording characteristic of an optical disk 1 is identified, and a recording pulse position is corrected at a correction accuracy according to the identifies information recording condition or information recording characteristic, such that a recording mark is formed in a predetermined position.

Abstract: An optical reproducing apparatus connectable to optical pickups and a method of controlling an optical pickup thereof are provided. The optical reproducing apparatus measures resistance of an optical pickup on a port of a connection unit to which the optical pickup is connected, and determines the type of the optical pickup according to the measured resistance. Accordingly, optical reproducing apparatuses may be controlled according to the type of optical pickups, and manufactured using various optical pickups without checking the type of optical pickups, which allows convenient manufacturing of optical reproducing apparatuses.

Abstract: An optical head device includes a light source configured to emit a light beam, a light collecting optical system configured to converge the light beam onto an information recording medium, a hologram element configured to diffract the light beam reflected from the information recording medium, and a photodetector having a plurality of detection regions configured to receive the light beam diffracted by the hologram element. The hologram element has a plurality of diffraction regions separated from each other by a straight line extending in a track direction of the information recording medium. At least one of the plurality of diffraction regions has a pattern which introduces coma aberration in the track direction to the diffracted light.

Abstract: A suspension for a head stack assembly, comprises a flexure with a suspension tongue, a flexure tail and a plurality of conductive traces extending between the suspension tongue and the flexure tail, each of said conductive traces having one end thereof terminated to an electrical pad formed on the suspension tongue for electrical connection to a slider and the other end thereof terminated to a connection pad formed on the flexure tail for both testing and bonding such that the flexure has no additional testing pads. The suspension with a flexure tail able to make the bonding and the dynamic performance testing on the pad area and thus reduce suspension length and increase flexure density for low cost. The invention also discloses a manufacturing method of the suspension and a HSA with such an suspension and a disk drive unit having such an HSA.

Abstract: 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.

Abstract: An optical disc drive having an optical pickup head emitting a light beam to an optical storage medium, detecting the light beam reflected from the optical storage medium, and outputting a signal based on the received reflected light, having a jitter measuring unit measuring jitter in signals output from the optical pickup head and having an evaluation unit determining from the measured jitter if the optical storage medium is good or defective. The jitter measuring unit measures jitter in a train of 3T or longer marks or spaces from an optical storage medium to which digital information is recorded as a train of marks or spaces of length kT based on a period T and an integer k of two or more.

Abstract: Methods and systems for the rapid evaluation of optical media reliability are disclosed. Simultaneous exposure of optical media to heat, humidity, and light has been found to be an effective test to differentiate more stable media from less stable media in a reasonable amount of time.

Abstract: A data storage device determines a zone layout based on a quality evaluation factor. The zone layout is designed such that a measurement value of the quality evaluation factor for each track in each zone is within a range between a predetermined upper limit and a predetermined lower limit and a maximum amount of variation of the measurement value within each zone is substantially equal to a difference between the upper limit and the lower limit.

Abstract: An optical disk apparatus and a method of performing a lead-in process with respect to an optical disk thereof includes a feature where an optical pickup unit reads out information recorded on a file system area of the storage area of the optical disk, and performs a lead-in process using the read-out file system if information recorded on a lead-in area of a storage area of the optical disk cannot be read out. Further, the optical disk apparatus may perform the lead-in process with respect to the optical disk even if there is a defect in the lead-in area.

Abstract: A method and apparatus for recording contents. The method includes recording contents on a disc; verifying whether an error occurs in the recording; and reducing the number of available recordings of the contents, which is included in recording authority information, by 1, if an error does not occur in the recording. According to the method, if an error occurs in recording, the number of available recordings may be prevented from being unreasonably reduced.

Abstract: The present invention provides a recording medium reproducing method comprising the steps of: irradiating light onto a recording medium, the recording medium including a data image and a reference pattern, the reference pattern being divided by a plurality of fractional regions, the fractional regions being in invert, rotational and symmetrical relationship; determining information associated to data-image distortion based on the reference pattern; and correcting position of the data image based on the information relating to data-image distortion.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method of identifying physical characteristic information of an optical disc includes: deriving a reading result by reading at least a first region of the optical disc, where a location of the first region is specified in a Blu-ray disc specification for recording information associated with recording management of a BD recordable disc; and identifying a first physical characteristic of the optical disc according to the reading result.

Abstract: 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.

Abstract: Disclosed is a magnetic recording medium evaluating method capable of providing a discrete-type or bit-pattern-type magnetic recording medium that has stable head floating characteristics even when concave and convex portions remain on the surface and can respond to high recording density with high productivity. A method of evaluating a magnetic recording medium having a magnetic recording pattern on at least one surface of a disk-shaped substrate and includes concave and convex portions corresponding to the magnetic recording pattern on the surface includes: floating and moving a head slider having a sensor attached thereto above the surface of the magnetic recording medium that is rotated; detecting a signal output from the sensor in a non-contact state between the head slider and the magnetic recording medium; and determining whether the magnetic recording medium is defective on the basis of the signal.

Abstract: 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.

Abstract: A method includes acquiring, by a data storage device, signals generated by one or more sensors that relate to a mechanical vibration of the data storage device. The one or more sensors are in electrical communication with the data storage device. The method includes storing a representation of the signals as data in the data storage device.

Abstract: A method and apparatus for determining the likelihood that a hard-disk drive (HDD) will experience an imminent error in operation is provided. The HDD comprises a differential pressure sensor capable of measuring the difference in the pressure between the interior and the exterior of the enclosure. The differential pressure sensor may reside in a breather filter covering an air passage within the enclosure. The HDD also comprises a risk assessment component capable of (a) determining an expression of how likely it is that the HDD will experience an imminent error in operation based, at least in part, upon the difference in pressure measured by the pressure sensor, and (b) communicating the expression to a user of the HDD. The HDD may optionally comprise one or more of an atmospheric pressure sensor, a particle counter, and a chemical vapor sensor which may be used by the risk assessment component.

Abstract: 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.

Abstract: An erasure information marking method for a burst cutting area (BCA) of a blu-ray disc (BD) is provided. The erasure information marking method includes obtaining at least four raw data recorded in the BCA; recognizing a record type of the BCA according to the four raw data; obtaining two duplicate copyright protection data, relating to the copyright protection of the BD, in the four raw data according to the record type of the BCA; and marking the erasure information of the BCA according to the difference between the two duplicate copyright protection data.

Abstract: A method for calibrating the offset of a micro actuator includes: setting a reference reflective plane with different focus voltage levels; focusing on test points on the reference reflective plane and recording the tracking voltages; selecting a standard focus voltage level; calculating the offset of the tracking voltage for each test point; curve-fitting the offsets into a tracking voltage curve for each focus voltage level; and acquiring an offset of a selected tracking voltage by interpolation or extrapolation to calibrate the selected tracking voltage.

Abstract: A method for rating an information recording medium according to the present invention includes the steps of: receiving a digital read signal, which has been generated based on an analog read signal representing information that has been read from the information recording medium, and shaping the waveform of the digital read signal; subjecting the shaped digital read signal to maximum likelihood decoding, thereby generating a binarized signal showing a result of the maximum likelihood decoding; and calculating the quality of the digital read signal based on the shaped digital read signal and the binarized signal. If the quality of the read signal is calculated by a PRML method in which a number of zero-cross portions are included in a merging path of a minimum difference metric, the quality is calculated by using only a state transition pattern in which only one zero-cross portion is included in a merging path of a non-minimum difference metric.

Abstract: 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.

Abstract: A method for calibrating a focusing error signal of a lightscribe disc includes the following steps. An optical pickup head is moved to a focusing reference surface by utilizing radial voltages to some predetermined measuring positions to find and record the best gain value used to calibrate the asymmetry of the focusing error signal. The best gain fitting curve is formed by curve-fitting, based on the recorded radial voltages and the best gain values. The best gain value is obtained by an interpolation or extrapolation method, and used to calibrate the asymmetry of the focusing error signal of a lightscribe disc.

Abstract: The present invention aims to provide a reproduced signal evaluation method and a write adjustment method for offering a Blu-ray disc having a large storage capacity with excellent media compatibility. An evaluation index L-SEAT is calculated through signed addition using a Euclidean distance difference calculated from at least one of target signals in which a focused edge is shifted to the right and left, and the quality of the reproduced signal is evaluated based on the evaluation index. Write condition adjustment using the index enables write adjustment not depending on SNR and achieving high adjustment accuracy.

Abstract: 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.

Abstract: The signal source generates a signal of a frequency higher than the vibration frequency of the slider of the hard disk drive, and supplies it to one end of the slider and the disk of the hard disk drive. The detector detects a signal output from the other end of the slider and the disk, and outputs a change in the capacitance between the slider and the disk as a voltage when the hard disk drive receives an impact.

Abstract: 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.

Abstract: 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.

Abstract: A novel evaluation index is introduced so as to allow both a total evaluation of data recording and an evaluation of individual detection patterns. A data recording evaluation method includes a step of reproducing the result of data recording performed on an optical disk and identifying a predetermined detection pattern in a reproduction signal, a step of detecting the signal state of the reproduction signal corresponding to the predetermined detection pattern, and a first calculation step of calculating a first recording state evaluation index value based on the detected signal state and a reference condition which is identified from the predetermined detection pattern and adjusted so as to reflect the signal state of the reproduction signal.

Abstract: This document relates to a method of compensating for a sensitivity variation of a tracking actuator with focusing offset when recording labels on a disc for label recording. A focusing point suitable for the position of an object lens in the circumference direction and/or the radius direction is detected, a tracking sensitivity corresponding to the detected focusing point is obtained based on information about a tracking sensitivity variation according to a focusing point variation, and labels are recorded on a label plane using the detected focusing point and tracking sensitivity. The information may be measured using at least two different types of discs one of which has a distance, between the surface of the disc and a pattern area required for a feed forward servo operation, different from the distance of the other.

Abstract: 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.

Abstract: 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.