Abstract: According to one embodiment, there is provided a method for detecting touchdown of head in a disk storage apparatus. The disk storage apparatus includes the head. The head includes a write element, a read element, a head disk interference (HDI) sensor, and a heater element. The HDI sensor detects thermal interference between the head and the disk. The method supplies alternating-current heater power to the heater element. The method increases the heater power in a step-by-step manner. The method further detects a phase of an output signal from the HDI sensor corresponding to the increased heater power, and detects the touchdown based on a change in the detected phase.

Abstract: A data storage device and method for enabling dynamic fly height control which is insensitive to off-track motions is described. In some embodiments, a hard disk drive acquires signal data from neighboring overlapping tracks which are unwritten, thermally erased, or AC demagnetized. Side-to-side (off-track) positional errors or oscillations of the read head do not affect the signal which arises solely from the magnetic domains on the disk. Thus, signal variations may only arise from changes in the fly height. In other embodiments, neighboring overlapping data tracks are prewritten with reference data. The width of the neighboring overlapping tracks exceeds any expected side-to-side positional errors of the read head, thus signal variations may only arise from changes in the fly height. For all embodiments, the noise or reference data signal may serve as a reliable dynamic measure of the fly height with no effects arising from off-track motions.

Abstract: A scissor style magnetic sensor having a novel hard bias structure for improved magnetic biasing robustness. The sensor includes a sensor stack that includes first and second magnetic layers separated by a non-magnetic layer such as an electrically insulating barrier layer or an electrically conductive spacer layer. The first and second magnetic layers have magnetizations that are antiparallel coupled, but that are canted in a direction that is neither parallel with nor perpendicular to the air bearing surface by a magnetic bias structure. The magnetic bias structure includes a neck portion extending from the back edge of the sensor stack and having first and second sides that are aligned with first and second sides of the sensor stack. The bias structure also includes a tapered or wedged portion extending backward from the neck portion.

Abstract: According to one embodiment, a magnetic medium's readback signal samples are processed iteratively to provide a slip-resistant read channel by feeding the decoder output decisions back to the read channel front end where they are used to drive the decision-aided digital signal processing functions and control loops. Since data decisions provided by the decoder are typically more reliable than those provided by the detector, a significant performance improvement is obtained. A more reliable operation of the digital front-end signal processing functions in turn allows improvements to the reliability of the decoded data. Usage of Error Correcting Code (ECC) schemes that are soft decodable makes the read channel technique, described according to various embodiments herein, particularly efficient.

Abstract: Implementations of the present disclosure involve a system and/or method for a target level driver of a host computer to obtain and maintain the state or mode of a physical or virtual tape drive storage system to restore the state of the tape drive storage system. The target level driver monitors one or more commands transmitted to the tape drive system from a user or administrator of the tape drive system. Through analysis and parsing of the one or more commands, the target level driver determines an operational mode state of the tape drive system and stores said mode state. Because the target level driver monitors the commands provided to the tape drive system, the stored operational mode state may include one or more operational modes not reported by the tape drive system.

Abstract: A disk drive is disclosed comprising a disk media, a head stack assembly (HSA) having a head coupled to its distal end, a microactuator used to provide fine position of the head and a voice coil motor (VCM) configured to actuate the HSA over the disk media, and control circuitry. The control circuitry may be configured to move the HSA in an alternating manner across the disk media while actuating the microactuator. One or more performance characteristics of the microactuator may be measured before and after the actuation of the microactuator, and failure may be detected based on the absolute or relative change of the one or more performance characteristics.

Abstract: A method and computer program product identify the location of a bad block on a disk platter of a hard disk drive, determine an avoidance area extending from the bad block, and prevent data from being written to the avoidance area.

Abstract: A method, apparatus and a data storage device are provided for implementing track following and data recovery with readback of shingled data written in overlapping shingled data tracks on a recordable surface of a storage device. Positional information is identified with data readback of shingled data written in overlapping shingled data tracks. The identified positional information is used to selectively modify at least one predefined channel parameter, for example, to provide enhanced track following and enhanced data recovery.

Abstract: A disk drive is disclosed comprising a disk and a head actuated over the disk, the head comprising a fly height actuator (FHA). The disk drive further comprises control circuitry including disk access circuitry, wherein during a calibration operation, the disk access circuitry is configured into a calibration mode that increases a heating of the head, and a fly height of the head is measured periodically to generate periodic fly height measurements that vary due to the heating of the head. A dynamic fly height (DFH) write profile is generated based on the periodic fly height measurements. During a write operation, the disk access circuitry is configured into a write mode and a DFH control signal is generated and applied to the FHA based on the DFH write profile.

Abstract: According to one embodiment, a disk storage apparatus includes a magnetic head, a detector, a calculator, and a decision module. The magnetic head has a high-frequency assisted element disposed close to a main magnetic pole that generates a recording magnetic field for perpendicular magnetic recording, the high-frequency assisted element applying a high-frequency magnetic field onto a magnetic disk during data recording. The detector detects an electrical resistance of the high-frequency assisted element. The calculator calculates time axis data indicative of a variation, on a time axis, in the electrical resistance value detected by the detector. The decision module determines whether the high-frequency assisted elements is malfunctioning based on the time axis data.

Abstract: Described are embodiments of an invention for customizing the range of acceptable write conditions to a tape of a tape cartridge that contracts or expands laterally based on environmental conditions. The tape drive utilizes servo information to determine if the tape has expanded or contracted from the nominal dimension and to determine the magnitude of the expansion or contraction. In the case of expansion, the magnitude of the determined expansion and the stored maximum amount of contraction must be below a predetermined threshold value to allow a write. In the case of contraction, the magnitude of the determined contraction and the stored magnitude of expansion must be below the same predetermined threshold value to allow a write. If the determined magnitude of contraction or expansion is greater than the stored magnitude of contraction or expansion, respectively, then the new extreme is stored.

Abstract: A disk drive is disclosed comprising a disk surface comprising a radius, a head operable to generate a read signal, and a voice coil motor (VCM) operable to actuate the head over the disk surface. A back electromotive force (BEMF) voltage generated by the VCM is measured. The VCM is controlled to move the head over substantially the entire radius of the disk surface in response to the BEMF voltage, and while moving the head the read signal from the head is processed to detect residual data recorded on the disk surface after erasing the disk surface.

Abstract: A determination is made in a tape drive of a potential deviation in tape dimensional stability of a tape, based on a current environmental condition and environmental conditions in which the tape is expected to be operational. A writing mechanism to write data to the tape is adjusted, based on the potential deviation in the tape dimensional stability.

Abstract: A breakdown prediction device of the present invention includes: a vibration measurement unit that measures vibrations generated from a device being monitored; and a signal processing unit that performs breakdown prediction when a specific vibration is measured at the vibration measurement unit, a maximum vibration amplitude value of the vibration exceeding an upper limit vibration amplitude threshold, and a vibration amplitude value thereof being below a lower limit vibration amplitude threshold at a point in time when a specified time is reached from a point in time when the vibration exceeds the upper limit vibration amplitude threshold.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of tracks. The head comprises a touchdown element operable to generate a touchdown signal. The touchdown signal is amplified by a gain to generate an amplified touchdown signal, and a touchdown event is detected by comparing the amplified touchdown signal to a threshold. During a calibration operation, the gain is adjusted and the threshold is adjusted until the amplified touchdown signal does not exceed the threshold. During a normal operation, the touchdown event is detected based at least partly on the adjusted gain and the adjusted threshold.

Abstract: A storage device includes a storage medium having a plurality of tracks of data. Reading apparatus for reading a current track of data that has been subject to previous encroachment to an extent from at least one adjacent track of data includes a write head that writes interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and circuitry that recovers data on the current track of data using the interfering data. A method for reading a current track of data, that has been subject to previous encroachment to an extent from at least one adjacent track of data, includes writing interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and recovering data on the current track of data using the interfering data.

Abstract: A disk drive is disclosed comprising a head actuated over a disk having a plurality of data tracks. A vibration is detected, and a write operation is configured to write a first plurality of blocks and a second plurality of blocks to a target data track based on the detected vibration. The first plurality of blocks are written to the target data track during a first revolution of the disk, and the second plurality of blocks are written to the target data track during a second revolution of the disk.

Abstract: A system detects adjacent track interference (ATI)/far track interference (FTI) in a data storage system. The system includes a micro-transition generator that introduces micro-transitions into data write patterns written to a magnetic media. A spectrum analyzer analyzes in the frequency domain read-back signals generated in response to the data write patterns. In particular, the spectrum analyzer calculates first and second signal-to-noise ratios (SNRs) based on read-back signals generated before and after a center track stress test. Adjacent track interference/far track interference effects are determined based on the first and second SNR values.

Abstract: A method, apparatus, and system are provided for implementing enhanced surface analysis test (SAT) function for microwave assisted magnetic recording (MAMR) hard disk drives (HDDs) using embedded contact sensor (ECS) and spin-torque oscillator (STO) signals. A preamplifier circuit receives the embedded contact sensor (ECS) and spin-torque oscillator (STO) signals and compares the received ECS and STO signals to identify magnetic disk media defects including bumps or thermal-asperity (TA) defects and pits or hole defects.

Abstract: A reception device and corresponding method for maintaining a high dynamic range of an AD converter circuit and preventing excessive input to the AD converter circuit is disclosed. For example, a reception device includes a variable gain amplifier circuit that amplifies an input analog signal with a gain controlled by a predetermined control signal, an analog-to-digital converter circuit an overload detector circuit with the same frequency characteristic as the analog-to-digital converter circuit. The overload detector circuit outputs a signal according to a comparison between a level of a signal input to the analog-to-digital converter circuit and a predetermined threshold. The signal that lowers the gain of the variable gain amplifier circuit more greatly is selected out of the signal from the overload detector circuit and another signal, and the gain of the variable gain amplifier circuit is controlled on the basis of the selected signal.

Abstract: Determining a parameter associated with whether a portion of a storage device is defective is disclosed. Determining comprises: obtaining known data associated with the portion; reading back from the portion to produce a read-back waveform; decoding the read-back waveform, including producing statistical information; and determining a parameter associated with whether the portion is defective based at least in part on the statistical information.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of tracks including a first fly height calibration track and a second fly height calibration track. The disk drive further comprises a fly height actuator operable to control a fly height of the head in response to a fly height control signal. When a refresh event is detected, calibration data is written to the second fly height calibration track. After writing calibration data to the second fly height calibration track, the first fly height calibration track is read in order to calibrate the fly height control signal applied to the fly height actuator. After calibrating the fly height control signal, the second fly height calibration track is read in order to recalibrate the fly height control signal applied to the fly height actuator.

Abstract: A two part process is used for modifying records to be written and retrieved from tape devices. A record is appended with a cyclic redundancy check and a string of zeros. Submitting the entire record to tape drives which are logical block protection enabled will result in no change. For drives that are not LBP enabled, the string of zeros at the end of the record is removed. In addition to determining whether a drive is LBP compliant, a determination may be made as to whether a drive is a linear tape open drive from a particular manufacturer. Linear tape open drives may behave similarly as drives which may not be enabled with logical block protection.

Abstract: According to one embodiment, a read/write apparatus includes a receiver and a refresh module. The receiver receives a write command requesting a write to a magnetic disk. The refresh module refreshes, when a first area of the magnetic disk includes a second area corresponding to the write command, data written in a third area, the third area being an area obtained by excluding the second area from the first area.

Abstract: A method for performing parallel flaw scans of a plurality of tracks of a storage device. The storage device includes at least one disk, at least two read sensors, at least two analog front ends, and at least two independent timing loops. Each disk includes at least one surface, wherein each surface includes a plurality of tracks. The method includes writing flaw patterns to tracks of one or more surfaces of one or more disks. The method also includes positioning a first read sensor to read a first track. The method further includes positioning a second read sensor to read a second track. The method additionally includes simultaneously reading signals from the first track and the second track. The method also includes simultaneously performing flaw scans on read back signals from the first track and the second track. The method further includes outputting flaw scan results.

Abstract: Storing data in a hard disk drive may include determining a percentage of storage usage (SU %) of the data tracks. If the SU % is less than a first threshold percentage (TP1), the method may include storing data to Nth data tracks. If the SU % is greater than or equal to TP1, but less than a second threshold percentage (TP2), the method may include storing data to about N/2 data tracks between said Nth data tracks. If the SU % is greater than or equal to TP2, the method may include storing data to data tracks between said N/2 data tracks and said Nth data tracks.

Abstract: Systems, methods, apparatus, and techniques are provided for controlling synchronization of a write clock. A frequency offset is estimated based, at least partially, on a location of the servo synchronization marker to produce the frequency offset estimate. A phase correction value and a frequency correction value associated with the write clock are obtained, and a data clock timing control signal is produced based on the frequency offset estimate, the phase correction value, and the frequency correction value. The data clock timing control signal is applied to a phase interpolator to modify a phase of the write clock.

Abstract: Tape head with thermal tape-head distance sensor to reduce the distance between the tape and the head to allow an increase in areal density. A tape head designed for reading and/or writing to a tape, including: a tape bearing surface shaped to form an air bearing when moving the tape with respect to the tape bearing surface; a thermal tape-head distance sensor circuit adapted to sense heat dissipated at the level of the tape bearing surface by the tape and thereby sense a distance between the tape bearing surface and the tape; and tape-head distance control means connected to the thermal tape-head distance sensor circuit to receive a signal provided by the tape-head distance sensor circuit and configured to alter the distance according to a signal received from the tape-head distance sensor circuit. This invention is further directed to a method of tape-head distance control for the above tape head.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to data processing including operational marginalization capability, and/or operational improvement capability.

Abstract: A system for identifying and compensating for non-linear transition shift in a magnetic medium data storage device is disclosed. The non-linear transition shift compensation system includes a non-linear transition shift estimation module adapted to generate non-linear transition shift estimates for specific bit patterns. The system further includes a pre-compensation module adapted to adjust the temporal spacing of binary transitions written to the magnetic medium based on the non-linear transition shift estimates generated by the non-linear transition shift estimation module for specific bit patterns corresponding to bit patterns appearing in the data being written to the magnetic medium.

Abstract: A tape drive device for storing data in a tape cartridge includes a comparison unit that compares a transfer speed of the data transmitted from a host machine to the tape drive device with a speed threshold, a speed determination unit that determines a writing speed to a tape cartridge using the speed threshold, and a data write unit that writes data to the tape cartridge, the data write unit writing data to the magnetic tape provided for the tape cartridge when the determined writing speed is higher than the speed threshold, and the data write unit writing subsequent data following data written to the magnetic tape to the non-volatile semiconductor memory provided for the tape cartridge when the determined writing speed is lower than the speed threshold.

Abstract: A method for writing information to a magnetizable disk surface on a disk drive includes designating a plurality of regions on a disk where information is to be stored, writing information representing data to a first track in at least one of the plurality of regions, writing information representing data to a second track in the at least one of the plurality of regions, the information written to the second track overwriting a portion of the first track, and determining an amount of the first track that is overwritten based on a performance factor. Determining an amount of the first track that is overwritten is done or accomplished on the fly. The amount to overwrite the track is done in the field rather than in a factory or manufacturing facility.

Abstract: A data processing circuit includes a long magnet identification circuit operable to identify long magnet bits in data to be processed, the long magnet bits comprising bits having a same value as a number of preceding and subsequent bits, an error calculation circuit operable to subtract an ideal version of the long magnet bits from the long magnet bits to yield an error signal, an adjacent track interference metric calculation circuit operable to calculate an adjacent track interference metric based on the error signal, and a comparator circuit operable to compare the adjacent track interference metric with a threshold value and to assert a refresh signal when the adjacent track interference metric is greater than the threshold value.

Abstract: According to one embodiment, a first defect detector executes a first scan test. The first scan test includes detecting a defect on a disk using a head disk interference sensor by scanning the disk using a head. The first scan test further includes identifying a range of cylinders indicated by servo data read by a read element when the defect is detected, as a first detected location of the detected defect. A compensator corrects the first detected location to a second detected location based on a position difference. The second detected location corresponds to a position of the head disk interference sensor at a time of detection of the defect.

Abstract: A disk drive is disclosed comprising a head actuated over a disk surface, the head comprising a temperature sensitive (TS) fly height sensor. The disk drive further comprises a ramp for parking the head, and control circuitry configured to process a fly height signal generated by the TS fly height sensor, wherein the fly height signal represents a fly height of the head over the disk, and detect whether the head is on the ramp in response to the fly height signal.

Abstract: A failure prediction system for performing failure prediction to a monitoring target device by detecting a state, comprising: a state detection unit for detecting state signals of no smaller than two different kinds, and outputting a detection signal corresponding to each of the state signals; a phase processing part for synchronizing a plurality of the detection signals; a signal analysis part for calculating a feature value indicating a feature of the state for each of the detection signals from the phase processing part; and a failure prediction part for performing failure prediction of the monitoring target device for each of the feature values by comparing the feature value in question and a reference value set in advance.

Abstract: The present inventions are related to systems and methods for data processing, and more particularly to data processing using distortion-correction loops with saturation-based assistance.

Abstract: Systems and methods for data processing, and more particularly to estimating or calculating interference between tracks on a storage medium.

Abstract: Various embodiments of the present invention provide systems and methods for read sensor characterization. As an example, a data storage device is disclosed that includes a storage medium, a read/write head assembly disposed in relation to the storage medium, and a track width setting circuit. The track width setting circuit is operable to: write data to at least a first track and a second track on the storage medium, read data from the second track, determine an estimated track offset where interference from the data written to the first track is insubstantial, and modify at least the second track width based at least in part on the estimated track offset. The first track is a first track width and the second track is a second track width.

Abstract: Various approaches that reduce the width variability of storage media data tracks are described. First and second data tracks are written so that the second track overlaps the first track. After writing the second track data to the second track, an effective width of the first track is determined. The effective width of the first track is the portion of the first track that is not overlapped by the second track. One or more additional write operations to the recording medium are performed to compensate for the effective width of the first track being less than a threshold. The additional write operations may include one or more of rewriting the first track data to a third track on the storage medium and writing additional redundancy information to supplement the coding of the first track data.

Abstract: 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.

Abstract: A data processing circuit includes a subtraction circuit operable to subtract an ideal version of a data pattern from a sampled version of a data pattern to yield a difference signal, an error calculation circuit operable to calculate an error between the ideal version of the data pattern and the sampled version of the data pattern based on the difference signal, and a comparator circuit operable to compare the error with a threshold value and operable to assert a track refresh signal if the error is greater than the threshold value. The track refresh signal is operable to trigger a magnetic storage device to refresh data on a data track.

Abstract: A method according to one embodiment includes measuring a current position error signal, and calculating a statistical derivative using the current position error signal sample. A kurtosis value is calculated using a current position error signal sample or derivative thereof. A threshold value is adjusted using the kurtosis value. The statistical derivative is compared to the threshold value, and writing is enabled when the statistical derivative does not exceed the threshold value.

Abstract: A system for monitoring and analyzing operation of a tape infrastructure. The system includes a plurality of real and virtual tape libraries each including a plurality of tape drives and tape media. The system includes a server linked to the tape library. On the server, a storage tape analytics application is provided that functions to extract raw data sets from the tape library corresponding to operations of the tape library. The data pertains to use of the drives and media during data storage operations and data about the activities of the real or virtual tape libraries. The analytics application stores the extracted data sets in an analytics database. The analytics application provides a user interface for viewing data in the analytics database, e.g., a GUI operable by monitoring personnel to view and interact with the gathered and processed tape operations monitoring data to provide historical and user-driven analysis of data for an entire data center.

Abstract: Embodiments of the present invention generally relate to a HAMR device having two temperature sensors disposed between a near field transducer (NFT) and a return pole. The two temperature sensors are aligned in a cross-track direction.

Abstract: An embedded contact sensor (ECS) element for fly-height control and touchdown detection. An embedded contact sensor (ECS) element with a resistance that changes with a temperature change, which senses a clearance change between a head slider and a disk of a disk drive. A resistance measurement section, within said head IC, that determines a value of direct current resistance (DCR) of said ECS element, wherein said value of DCR changes with a temperature change, wherein said temperature change is caused by an air bearing cooling and frictional induced heating at a head disk interface. A resistance slope to fly-height conversion section that dynamically determines a target fly-height value for said head slider over said disk based on changes in said value of DCR.

Abstract: Technologies are described herein for detecting adjacent track interference in a storage device using a size-adjustable sliding window. A value for an inter-track interference factor associated with at least one adjacent track is determined for a first area of a data track of the storage device. The first area may encompass a plurality of sectors of the data track. Next, it is determined whether the value of the calculated inter-track interference factor is greater than a threshold value, and if so, an indication of inter-track interference corresponding to the first area is stored in the storage device.

Abstract: A recording apparatus includes a head unit, which includes a driver, and a recording data transmitter that transfers recording data to the head unit via a signal line. The recording apparatus further includes a switching unit in the head unit that switches a driving signal applied to the driver between conductive and nonconductive states based on the transferred recording data, a partition signal output unit in the recording data transmitter that outputs a partition signal that partitions a data signal of the recording data to the head unit in response to switching by the switching unit, and a data selector in the head unit that selects data to be discarded from the transferred recording data based on the partition signal.

Abstract: Systems and methods for making fast measurements of channel performance metrics such as error margin and off-track recording capability in shingled magnetic recording are provided. One such method involves writing a plurality of shingled tracks on the disk, measuring an off track read capability (OTRC) of each of the plurality of shingled tracks, determining radial endpoints of the measured OTRC for each of the plurality of shingled tracks, determining an approximate radial center for each of the plurality of shingled tracks based on the respective OTRC radial endpoints, and measuring a channel performance metric at a range centered around the approximate radial center for each of the plurality of shingled tracks. In one such case, the channel performance metric involves error margin. One such system includes a processor coupled to a memory, a magnetic transducer, and a test platform, where the processor is configured to perform the method.

Abstract: A storage device includes a storage medium having a plurality of tracks of data. Reading apparatus for reading a current track of data that has been subject to previous encroachment to an extent from at least one adjacent track of data includes a write head that writes interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and circuitry that recovers data on the current track of data using the interfering data. A method for reading a current track of data, that has been subject to previous encroachment to an extent from at least one adjacent track of data, includes writing interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and recovering data on the current track of data using the interfering data.