According to one embodiment, a magnetic recording apparatus measures and stores recording signal quality of a disk at an initial stage, inspects the recording signal quality before data is recorded, determines whether or not the recording signal quality obtained in the inspection satisfies a standard when compared to the stored recording signal quality at the initial stage, adjusts, based on a result of the determination, light irradiation power of a light irradiation element so as to satisfy the standard, determines a read offset amount based on a result of the adjustment, and performs control so that a position of a read head is shifted based on the determined read offset amount.

A method, computer system, and computer program product for determining head wear of magnetic tape head elements of tape drives during operation. The method may include receiving a first calibration parameter for a first tape head element at a first time. Calibration parameter for the first tape head element may be compared with a reference parameter. Determination may be made whether to remove the first tape head element from service or generate a warning, based on a result of the comparison. Method may include generating the first calibration parameter by calculating midpoint bias voltage for the first tape head element as a function of bias current and head resistance. The first calibration parameter for the first tape head element may be bias current parameter or bias resistance parameter. The first calibration parameter for the first tape head element may be less than, equal to, or greater than the reference parameter.

A data storage device is disclosed comprising a head actuated over a disk surface, wherein the head comprises a plurality of elements including a write assist element. A bias signal applied to the write assist element is controlled such that the write assist element is substantially unprotruded, and while the write element is substantially unprotruded, an air bearing resonant frequency (ABRF) of the head and disk surface is measured. The bias signal applied to the write assist element is controlled such that the write assist element protrudes toward the disk surface, and while the write assist element protrudes toward the disk surface, the head is excited at the measured ABRF and the head touching down onto the disk surface is detected.

A data storage device is disclosed comprising an elevator actuator configured to actuate a head along an axial dimension, and a position sensor configured to generate a sinusoidal sensor signal representing a position of the head along the axial dimension, wherein the position sensor comprises a sensor element and an encoder strip comprising a pattern having at least one region that causes a disturbance in the sinusoidal sensor signal. The elevator actuator is controlled to move the head in a first direction along the axial dimension to detect the disturbance in the sinusoidal sensor signal, and when the disturbance in the sinusoidal signal is detected, the elevator actuator is controlled to move the head in a second direction along the axial dimension opposite the first direction in order to measure a zero crossing of the sinusoidal sensor signal.

Methods and apparatus for allocating logical sectors and bands to store data on interlaced magnetic recording tracks. The systems and methods include formatting a data storage medium to include a plurality of bands, each band of the plurality of bands including a plurality of tracks, the plurality of tracks including a subset of top tracks interlaced with a subset of bottom tracks, and each track of the plurality of tracks including a number of sectors, formatting a first band of the plurality of bands, determining an isolation region of the first band, and formatting a second band of the plurality of bands responsive to determining the isolation region of the first band.

This disclosure is related to systems, devices, processes, and methods to optimize a laser power boost amplitude, a laser power boost duration, or both in a heat-assisted data recording device, such as in heat-assisted magnetic recording (HAMR). The amplitude and duration for the laser power boost may be determined for a specific portion of a write operation, such as a first sector of the write operation. During operation of a data storage device, the laser power boost may provide additional power to the laser for the specific portion. Once the laser power boost duration has elapsed, the data storage device may continue providing power to the laser at the normal power input range of the laser. The laser power boost settings may be determined on a per head per zone basis, per track basis, or another configuration.

A data storage device is disclosed comprising a first disk comprising a first disk surface, a second disk comprising a second disk surface, an elevator actuator configured to actuate a head along an axial dimension relative to the first and second disks, a radial actuator configured to actuate the head radially over the first disk surface or the second disk surface, and a position sensor configured to generate a sinusoidal sensor signal representing a position of the head along the axial dimension. A crashstop_offset along the axial dimension is measured from a crashstop position of the elevator actuator to a zero crossing of the sinusoidal sensor signal.

Methods and apparatus for allocating logical sectors and bands to store data on interlaced magnetic recording tracks. The systems and methods include formatting a data storage medium to include a plurality of bands, each band of the plurality of bands including a plurality of tracks, the plurality of tracks including a subset of top tracks interlaced with a subset of bottom tracks, and each track of the plurality of tracks including a number of sectors, formatting a first band of the plurality of bands, determining an isolation region of the first band, and formatting a second band of the plurality of bands responsive to determining the isolation region of the first band.

Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.

A data storage device is disclosed comprising a head actuated over a disk. A test pattern is read from a first part of the disk to generate a first read signal that is sampled to generate a first sequence of signal samples. The test pattern is read from a second part of the disk to generate a second read signal that is sampled to generate a second sequence of signal samples. A third sequence of signal samples is generated by at least one of amplitude-inverting the second sequence of signal samples, time-inverting the second sequence of signal samples, and amplitude-inverting and time-inverting the second sequence of signal samples. A quality metric is generated based on the first sequence of signal samples and the third sequence of signal samples, and a data density of the disk is configured based on the quality metric.