Abstract: A method includes generating synthetic data related to known defect patterns on surfaces of magnetic media using parameterized rules. A classifier model is trained with the synthetic data so that the classifier model learns how to detect and identify defect patterns on magnetic media. Performance of the classifier model is validated by using real defect pattern data. The classifier model is deployed for use in identifying defective data patterns on magnetic media test specimens. The classifier may be used before or after clustering defect data points on surfaces of magnetic media.

Abstract: Operations include compensating for a Tracking Error Signal (TES) offset in an optical tape drive. The tracking error offset compensation system detects a control signal for controlling movement of an optical head across a surface of a tape. The tracking error offset compensation system computes an estimated movement of the optical head, based on the initial control signal. The tracking error offset compensation system determines an estimated TES offset, based on the estimated movement of the optical head. The tracking error offset compensation system uses the estimated TES offset to correct a TES. The tracking error offset compensation system transmits the corrected TES, for controlling additional movement of the optical head.

Abstract: Embodiments are provided for syncing multiple electronic devices for collective audio playback. According to certain aspects, a master device connects (218) to a slave device via a wireless connection. The master device calculates (224) a network latency via a series of network latency pings with the slave device and sends (225) the network latency to the slave device. Further, the master devices sends (232) a portion of an audio file as well as a timing instruction including a system time to the slave device. The master device initiates (234) playback of the portion of the audio file and the slave devices initiates (236) playback of the portion of the audio file according to the timing instruction and a calculated system clock offset value.

Abstract: A method for correcting a mounting position of a disk device on a rack, includes performing a normal seek to position a head of the disk device above a target position on the disk, determining that the normal seek has failed, and performing an excitation seek that causes a position of a base supporting the disk to move and reposition the disk. The disk device includes a carriage arm supporting the head, a voice coil motor configured to drive the carriage arm to position the head, the base supporting the magnetic disk, the voice coil motor, and the carriage arm, and a control unit configured to control a current to the voice coil motor to be supplied with a first current profile during the normal seek and with a second current profile during the excitation seek.

Abstract: An apparatus comprises a slider having an air bearing surface (ABS) and a near-field transducer (NFT) at or near the ABS. An optical waveguide is configured to couple light from a laser source to the NFT. A resistive sensor comprises an ABS section situated at or proximate the ABS and a distal section extending away from the ABS to a location at least lateral of or behind the NFT. The resistive sensor is configured to detect changes in output optical power of the laser source and contact between the slider and a magnetic recording medium.

Abstract: A storage device disclosed herein includes a transducer head with a proximity sensor that generates head-disc proximity signals, a digitizer configured to convert the analog proximity signals from the proximity sensor to digitized sample data, a discrete wavelet transformation (DWT) module configured to analyze the digitized sample data by performing an enhanced DWT on the digitized sample data to generate DWT coefficients, and a modal filter configured to determine dominant head-disc interference (HDI) modes for a transducer head by analyzing the DWT coefficients.

Abstract: An apparatus-implemented method according to one embodiment includes detecting an error while writing data to a tape volume, and repositioning the tape in response to detecting the error. Further, the method includes determining, after the repositioning, a current position of the tape, and determining, based on the current position, whether a rewrite of data associated with the error to the tape volume is allowed. A system according to one embodiment includes a processor and logic integrated with and/or executable by the processor. The logic is configured to cause the foregoing method to occur. A computer program product according to one embodiment includes a computer readable storage medium having program instructions embodied therewith, the program instructions readable and/or executable by a controller to cause the controller to perform the foregoing method.

Abstract: An optical information recording/reproducing device which records an interference pattern between a reference beam and a signal beam as a hologram in an optical information storage medium or reproduces information from the optical information storage medium, the optical information recording/reproducing device includes a light source unit which emits a light beam, a signal-beam/reference-beam optical unit which generates the signal beam and the reference beam from the light beam and irradiates the optical information storage medium, a spatial light modulator which adds information to the generated signal beam, a photodetection unit which detects a reproduced beam from the optical information storage medium and acquires a reproduced image constituted by a plurality of pixels arrayed in a lattice shape, and a signal processing unit which performs equalization processing to a first pixel of the reproduced image to have a target characteristic.

Abstract: A magnetic disk device includes a magnetic disk, a head slider and a control circuit. The head slider includes a read element, a write element, a first heater and a second heater. The first heater is arranged nearer to the read element than the write element. The second heater is arranged nearer to the write element than to the read element. The control circuit controls a ratio of powers to be supplied to the first heater and the second heater to adjust a first spacing between the read element and the magnetic disk and a second spacing between the write element and the magnetic disk.

Abstract: A method of testing a dynamic write field of a recording head includes preparing a test magnetic medium and recording a write signal on the test magnetic medium with the write signal being set at a first write parameter and a second write parameter. An average of multiple read-back signals of the recorded write signal are captured to determine an average amplitude of the read-back signals. The recording of the write signal on the test magnetic medium and the capturing of the average of multiple read-back signals of the recorded write signal are repeated to determine the average amplitude of the read-back signals by fixing the first write parameter of the write signal and changing the second write parameter of the write signal until the average amplitude of the read-back signals saturates.

Abstract: In a method, read signals from each of a plurality of read transducers of a data head are buffered for each of a plurality of cross-track positions of the head relative to a data track. The buffered read signals are processed to establish a quality metric for each of the read signals and at least one combination read signal comprising at least two of the read signals. A data recovery cross-track position and a reader configuration comprising one or more of the read transducers are identified based on the quality metrics. A data read operation is then performed with the data head in the data recovery cross-track position using the read signals from the identified reader configuration.

Abstract: Methods of forming a NFT the methods including forming a hard mask positioned over at least a portion of the rod, the hard mask including at least one layer; patterning a resist mask over the hard mask, the resist mask having an edge positioned over at least a portion of the rod; etching a portion of the hard mask to expose a back edge of the rod and to form a back edge of the hard mask, wherein the back edge of the rod is equivalent to the back edge of the peg; and wherein a forward portion of the rod which is the portion of the rod forward of the back edge is covered by the hard mask; forming a disc mask including a void configured to form a disc of a NFT, the disc mask being formed over at least a portion of the hard mask so that the exposed back edge of the rod is within the void configured to form the disc; etching an area exposed in the void of the disc mask to remove both a rear portion of the rod and the surrounding dielectric up to the back edge of the hard mask edge; depositing a disc material in th

Abstract: An apparatus comprises a slider configured for writing data to and reading data from a magnetic recording medium and for heat-assisted magnetic recording. The slider comprises a heater configured to receive an AC signal and to cause oscillation in a spacing between the slider and the medium, and a contact sensor situated on the slider and configured to produce a DC response signal. A detector is coupled to the slider and configured to measure an amplitude of a spike in the DC response signal, calculate a ratio between the spike amplitude and an amplitude of the DC response signal, and detect contact between the slider and the medium in response to the ratio exceeding a predetermined threshold.

Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a laser configured to heat the disk while writing data to the disk. A write power is applied to the laser in order to write data to the disk during a write operation. A determination is made as to whether the laser power should be in an off state after the write operation. After the write operation, the laser power is gradually decreased to the off state based on a first decrease function.

Abstract: Embodiments described herein involve a method comprising generating a seek command in a heat-assisted magnetic recording (HAMR) device. A first current is supplied to a laser diode of the HAMR device in response to the seek command to preheat the laser diode. The first current is insufficient to cause erasure of data on media of the HAMR device. A second current that is greater than the first current is supplied to the laser diode for writing to a magnetic recording medium of the HAMR device after executing the seek command. Preheating the laser diode reduces a likelihood of a laser mode hop occurring while writing to the medium.

Abstract: A set of first signal light and reference light with a phase difference of almost 0 degree, a set of second signal light and reference light with a phase difference of almost 180 degrees, a set of third signal light and reference light with a phase difference of almost 90 degrees, and a set of fourth signal light and reference light with a phase difference of almost 270 degrees are generated. A first differential signal as a difference between a first light-receiving signal obtained by a first light-receiving element and a second light-receiving signal obtained by a second light-receiving element is calculated, and a second differential signal as a difference between a third light-receiving signal obtained by a third light-receiving element and a fourth light-receiving signal obtained by a fourth light-receiving element is calculated. The first differential signal and the second differential signal are supplied to respective FIR filters.

Abstract: A preamplifier circuit can include a control line dedicated to receive a control signal that corresponds to indicating a specific register of the preamplifier circuit, which can allow the preamplifier to switch between utilizing two or more registers to control a current output of the preamplifier circuit. The preamplifier circuit may also have a serial input to program multiple registers of the preamplifier circuit in a serial fashion. In some embodiments, the current output may be a laser bias current. The preamplifier may adjust an output current that drives a laser emitter based on a control signal indicating which specific registers controls the output current. Further, a controller, such as a system-on-chip controller, may selectively vary the control signal to affect the current output of the preamplifier circuit. These systems and methods may be particularly useful for lasers and heat-assisted magnetic recording (HAMR).

Abstract: Systems and methods for forward corrupted track detection and by-pass are described. In one embodiment, a storage system comprising a storage controller performs a read operation for a target track of a shingled magnetic recording (SMR) disk drive and detects a read operation failure of the read operation for the target track. The storage controller also performs a boundary track read operation on one or more tracks including or adjacent to the target track and detect a forward corruption area based on the boundary track read operation. In another embodiment, a method is provided that includes detecting a read operation failure of a read operation for a track of a disk drive and performing a boundary track read operation on one or more tracks including or adjacent to the target track. The method also includes detecting a forward corruption area based on the boundary track read operation.

Abstract: The present technology relates to an information processing device and method, a recording medium, and a program, which can improve a data transfer speed. In the recording medium, a recording area is divided into a plurality of simulated zones and a set of the plurality of simulated zones composes a simulated zone group. Then, an address is set to each area in the simulated zones so that the addresses are interleaved between the simulated zones composing the simulated zone group. By interleaving the addresses between the simulated zones in this manner, a local seek operation or a rotational delay can be reduced and the data transfer speed can be improved when recording or reproducing data to the recording medium in more than one channel at the same time. The present technology can be applied to an optical disk.

Abstract: A computer-implemented method, according to one embodiment, includes, performing anti-aliasing filtering on each of a plurality of symmetrical square wave signals, each symmetrical square wave signal having a frequency that is a different fraction of a frequency of a data read clock. The filtered symmetrical square wave signals are passed through a band pass filter. An amplitude of each of the symmetrical square wave signals is measured after the band pass filtering. In response to the amplitudes of the symmetrical square wave signals being within a predefined range, anti-aliasing settings used during the anti-aliasing filtering are stored. In response to the amplitudes of the symmetrical square wave signals being outside the predefined range, the anti-aliasing settings are changed.