Abstract: According to one embodiment, a contact-detecting method includes calculating a representative value for each of a plurality of first zones. The plurality of first zones is provided at different radial locations on the disk. The representative value is calculated based on values measured at a plurality of different radial locations included in each of the first zones. The method includes detecting a contact point at which a first member contacts with a second member based on a first difference. The first difference is a difference between a value measured at an objective measuring point and a representative value of a second zone among the plurality of first zones. The objective measuring point is included in a third zone among the plurality of first zones. The second zone is arranged radially inward of the third zone.

Abstract: Methods for determining a variable data frequency for recording data on a zone of a magnetic storage disc, each zone including a plurality of tracks and each track including a plurality of sectors, the method includes measuring a signal to noise ratio (S/N) around at least a first track in a first zone; and modulating a data frequency based on the measured S/N around the first track.

Abstract: A data sector is read using two or more passes of a read head over a recording medium. Each of the passes corresponds to a different cross-track offset, each of the data sectors being divided into two or more blocks. For each of the blocks, data is selected from one of the passes that read the block with a higher quality than other passes that read the block. The selected data from each of the blocks to is combined to form recovered data of the data sector.

Abstract: Structures and methods are disclosed for parallel biasing and testing, at dc and high frequency, of two or more read heads within a two dimensional magnetic recording (TDMR) slider. Testing of heads comprises both conventional tests of the individual heads within the slider, as well as tests for interactions between the heads which are very closely spaced within the slider and thus may exhibit various magnetic, capacitive, ohmic, and stress-related interactions not seen in non-TDMR heads having only a single read head. Overall testing times are nearly the same as for single head testing.

Abstract: A novel automatic record player for playing a phonograph record includes a base, a turntable, upper and lower hubs, a tonearm, a drive unit, a pinion, a control cam, a main arm, an auxiliary arm, first and second micro-switches, a clutch member, a first clutch actuating member, a switch activating member, an actuating pin, a synchronizing unit, a position guide, and an elongated member. When the clutch member is actuated by the first clutch actuating member, the tonearm is automatically positioned on the phonograph record.

Abstract: An apparatus includes a waveguide, a magnetic pole, and a near-field transducer. The near field transducer is positioned at or near a media-facing surface. The near-field transducer is operatively coupled to the waveguide. The near-field transducer includes an enlarged region. The near-field transducer also includes a peg region extending from the enlarged region towards the media-facing surface. The peg region is separated from the magnetic pole. The near-field transducer also includes a structure positioned between the magnetic pole and the peg region. The structure is separated from the peg region by a gap. The structure extends from the enlarged region towards the media-facing surface. The structure is configured to extend generation of surface plasmons toward the magnetic pole.

Abstract: A sensor supported by a head transducer has a temperature coefficient of resistance (TCR) and a sensor resistance. The sensor operates at a temperature above ambient and is responsive to changes in sensor-medium spacing. Conductive contacts connected to the sensor have a contact resistance and a cross-sectional area adjacent to the sensor larger than that of the sensor, such that the contact resistance is small relative to the sensor resistance and negligibly contributes to a signal generated by the sensor. A multiplicity of head transducers each support a TCR sensor and a power source can supply bias power to each sensor of each head to maintain each sensor at a fixed temperature above an ambient temperature in the presence of heat transfer changes impacting the sensors. A TCR sensor of a head transducer can include a track-oriented TCR sensor wire for sensing one or both of asperities of the medium.

Abstract: A hologram reproducing device which reproduces information from a recording medium having information recorded by interfering a signal beam and a reference beam, provided with a first light-angle change unit which changes an irradiation angle of the reference beam; a second light-angle change unit which changes the irradiation angle of the reference beam; a photodetector which detects a reproduction beam; a first light-angle drive-signal output unit which outputs a drive signal of the first light-angle change unit; a first light-angle control unit which controls the first light-angle change unit on the basis of the output of the photodetector; a second light-angle drive-signal output unit which outputs a drive signal of the second light-angle change unit; a second light-angle control unit which controls the second light-angle change unit; and a light-angle interpolation processing unit which controls a control target value of the second light-angle control unit.

Abstract: A product according to one embodiment includes a magnetic recording tape having opposite ends and at least one servo track, a longitudinal axis of the magnetic recording tape being defined between the ends. The at least one servo track has a plurality of straight first magnetic bars, and a plurality of straight second magnetic bars spaced from the first magnetic bars. A width of each of the at least one servo track is defined in a direction perpendicular to the longitudinal axis of the magnetic recording tape between sides of the servo track, the sides of each servo track extending along opposite ends of the each of the first magnetic bars. Lengths of the second magnetic bars between outermost ends thereof are less than the width of the associated servo track.

Abstract: A thermally assisted magnetic recording head slider includes a light source unit having a light emitting element emitting laser light and a submount holding the light emitting element, and slider including a thin-film laminated part having a main magnetic pole layer, a near-field light generating element and an optical waveguide. A combination of the light emitting element and near-field light generating element is composed of a first pattern or second pattern. The light source unit is mounted on a light source placing surface so that a substrate surface of the light emitting element is orthogonal to a laminated surface of the thin-film laminated part. A plurality of electrode pads are formed on the outer end surface of the slider. The light source unit has a first element electrode and second element electrode.

Abstract: A data storage device is disclosed comprising a disk comprising a plurality of data tracks each comprising a plurality of data sectors, and a head actuated over the disk. A first frequency preamble is written to a first data sector of a first data track and a second frequency preamble is written to a second data sector of a second data track, wherein the first frequency is different from the second frequency and the first data track is adjacent to the second data track.

Abstract: An apparatus for two-dimensional magnetic recording includes a storage medium, an array of magnetoresistive read heads disposed adjacent the storage medium and spaced to read a data track, a number of leads connected to the array of magnetoresistive read heads, and number of bias circuits connected to the array of read heads by the leads. The bias circuits can be configured to independently bias each of the array of read heads with the array of read heads connected in series or in parallel.

Abstract: A hard disk drive is adapted to take the most recent estimated read head positions (the position error signal or PES values) that are obtained during writing and write those values into the data sectors as written PES (WPES) values. The WPES values are available on readback for use as a predictor of the positions in which subsequent data sectors were written and are also available for use in a data recovery procedure should a particular data sector fail to be recovered. In two-dimensional magnetic recording, the difference between the WPES value and the read PES value is a quantity required to rapidly select the best 2D equalizer. The PES values may be encoded prior to being written into the data sectors. The WPES values are appended to the data sectors after the preamble and sync fields, which occur after every servo sector.

Abstract: Systems and methods relating generally to data processing, and more particularly to adjusting gain parameters in relation to data processing.

Abstract: The present disclosure describes systems and techniques relating to storage devices, such as storage devices that employ Two Dimensional Magnetic Recording (TDMR). According to an aspect of the described systems and techniques, a device includes: a first read channel to process a first input signal obtained from a Two Dimensional Magnetic Recording (TDMR) storage medium using a first read head, wherein the first read channel includes a first analog to digital converter (ADC); a second read channel to process a second input signal obtained from the TDMR, storage medium using a second read head, wherein the second read channel includes a second ADC; and a single digital timing loop (DTL) for both the first read channel and the second read channel, wherein the single DTL is configured to control interpolation of timing of sampling for the first and second ADCs.

Abstract: Technology is disclosed for deferring storage operations (e.g., writes or reads) during hostile events. When a data storage device experiences a hostile event, e.g., a vibration, shock, etc. contact by a head of the data storage device with a disk surface can cause errors or indeed damage. The technology can cause a data storage device to suspend storage operations until the hostile event is no longer detected.

Abstract: A hard disk device includes a main body and a temperature alarm circuit. The temperature alarm circuit includes a temperature detecting module detecting an internal temperature of the hard disk device, a control chip electrically coupled to the temperature detecting module to receive the internal temperature and configured to compare the internal temperature with a first preset temperature and a second preset temperature, a voltage pull-up module electrically coupled to the control chip, and an alarm module electrically coupled to the voltage pull-up module. The control chip outputs a control signal to the voltage pull-up module, the voltage pull-up module pulls up voltage of the control signal, and transmits the voltage pulled up control signal to the alarm module, and the alarm module alarms, in event that the internal temperature is higher than or equal to the first preset temperature or less than or equal to the second preset temperature.

Abstract: A method for calculating an average phase offset in a two dimensional magnetic recording system includes calculating a phase offset as a difference between a phase of a first signal derived from a first read head and a second phase of a second signal derived from a second read head, correcting for phase wrapping differences between the phase offset and a previous phase offset, determining whether the phase offset is consistent with the previous phase offset, and calculating an average phase offset which includes the phase offset only if it is consistent with the previous phase offset.

Abstract: A method involves receiving light from a light source at a fundamental transverse electric (TE00) mode or a fundamental transverse magnetic (TM00) mode. A waveguide polarization multiplexes the light to a combined mode that includes the TM00 mode and a first higher-order transverse electric (TE10) mode. A near-field transducer is excited via the light at the combined mode.

Abstract: A data encoder includes an encoding logic circuit configured to encode input data to apply run length limiting using state splitting of a code trellis, and a lookup table configured to apply a block-enumerable map on an un-split version of the code trellis, wherein entries in the lookup table are compressed.