Abstract: An apparatus includes a slider configured for heat-assisted magnetic recording. An input coupler of the slider is configured to-receive light produced by a light source. A waveguide of the slider comprises a waveguide core tapering from a first portion having a first cross sectional width to a second portion having a second cross sectional width along the light propagation direction. The second cross sectional width being smaller than the first cross sectional width, and the second portion having an output end. The waveguide includes at least one cladding layer comprising a metallic material. The at least one cladding layer surrounds at least the core. The at least one cladding layer is configured to sink heat away from the waveguide core. The waveguide is configured to provide a surface plasmon-enhanced near-field radiation pattern proximate the output end in response to the light received at the transducer region.

Abstract: A temperature compensation equation is generated during manufacture of a heat-assisted magnetic recording (HAMR) disk drive using initial total currents supplied to a laser diode of the disk drive at different initial operating temperatures. The total currents represent currents for recording data to or erasing data from the medium. The temperature compensation equation is stored in the disk drive, and updated, during field operation, using a subsequent total current associated with an operating temperature differing from the initial operating temperatures. The total current supplied to the laser diode for a subsequent write operation is adjusted using the updated temperature compensation equation in response to the operating temperature at the time of the subsequent write operation.

Abstract: Embodiments provide a terminal, and the terminal includes a body, a cover body covering the body, a circuit board mounted in the body, a central processing unit welded on the circuit board, a control part mounted on the cover body, and a protection switch welded on the circuit board. A hard disk slot for accommodating a hard disk is disposed in the body. The cover body is detachably mounted on the body, and is configured to seal the hard disk in the hard disk slot. The cover body is opened to drive the control part to open the protection switch. An electrical signal variation is generated due to opening of the protection switch. After detecting the electrical signal variation, the central processing unit instructs the hard disk to perform data protection and powers off the hard disk.

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: A hard disk device comprises a scanning mechanism that simultaneously scans a first recording medium surface with a first recording head and a second recording medium surface with a second recording head, a table storing band relative position information for a first band on the first recording medium surface and a second band on the second recording medium surface, and a processor. The processor calculates an inter-plane relative trajectory error between the first and second recording heads, determines a data access order performed by the first recording head on the first band and the second recording head on the second band, based on the band relative position information and the inter-plane relative trajectory error, and causes the first recording head to access a track and the second recording head to access a track in the data access order determined by the determining unit.

Abstract: According to one embodiment, a storage device includes a detector, a demodulator, a controller, and a recorder. When a user data item is split data including first data being at least part of a first code word and second data being at least part of a second code word, the controller sets a start position of the second data for forced search of the second code word on the basis of the position of a sync mark recorded in the recorder when the forced search of the first code word has succeeded.

Abstract: A data storage device is disclosed comprising a head actuated over a disk surface comprising a plurality of servo sectors, wherein each servo sector comprises a servo burst field. Across a first radial band of servo tracks, the servo burst field comprises a first length, and across a second radial band of servo tracks, the servo burst field comprises a second length longer than the first length. When the head is over the first radial band of the servo tracks, the head is servoed over the disk surface based on the first read element reading a first servo sector and the second read element concurrently reading a second servo sector different from the first servo sector. When the head is over the second radial band of the servo tracks, the head is servoed over the disk surface based on the first read element reading a third servo sector.

Abstract: According to one embodiment, a magnetic disk device including a disk, a head which reads data from the disk, a memory which records data, and a controller which includes a table, and records, at a first time point at which a read gate is open, a first area number of a first area of the table in which first information related to first data is recorded, a first serial number of the first data added when the read gate is open, and a first count value of the first data, in the first area.

Abstract: Implementations disclosed herein include a method to synthesize the controller of a multi-stage servo control system with multiple actuators in a hard disk drive by dividing controller synthesis into multiple dual-stage steps. The method includes measuring a first output of a first plant corresponding to a first actuator, measuring a second output of a second plant corresponding to a second actuator, designing a first controller responsive to the first output, designing a second controller responsive to the second output, and combining the first output and the second output to obtain a first combined output in a first dual-stage. The method also includes designing a third controller responsive to the first combined output, measuring a third output from a third plant corresponding to a third actuator, designing a fourth controller responsive to the third output, and combining the first combined output and the third output to obtain a second combined output.

Abstract: A data recording apparatus includes a disk, a read/write head, and a control circuit configured to control the head to perform reading of first data on the disk according to a first format and writing of second data to the disk according to a second format, wherein the second data is generated by compressing at least a part of the first data, and the second format is determined according to a data size of the second data.

Abstract: A magnetic recording apparatus in an embodiment includes a magnetic head, a storage, a detector, and a controller. The magnetic head records data on a recording medium. The storage stores first current parameters defining a first current waveform, second current parameters defining a second current waveform, and recording bit sequence information. The detector detects a discontinuity point from the recording bit sequence information. The discontinuity point is defined by a position at which recording bit lengths are discontinuous. The controller controls a waveform of a recording current of the magnetic head, based on the first current parameters at a recording bit that is not next to the discontinuity point and based on the second current parameters at a recording bit that is next to the discontinuity point.

Abstract: A magnetic disk device includes a magnetic disk that includes a plurality of tracks, a magnetic head for reading data from the magnetic disk, and a controller. The controller begins controlling the magnetic head to move to a second track of the plurality of tracks from a first track of the plurality of tracks before decoding of a first track signal output from the magnetic head is completed, wherein the first track signal is output from the magnetic head while the magnetic head is positioned over the first track.

Abstract: An example system may include a first vertical cavity surface emitting laser (VCSEL) that includes a first integrated polarization locking structure to produce a polarized optical data signal. The system may also comprise a second VCSEL that includes a second integrated polarization locking structure, the second integrated polarization locking structure orthogonal to the first integrated polarization locking structure, to produce an orthogonally polarized optical data signal. Lenses may be disposed on the substrate opposite the first VCSEL, to collimate the polarized optical data signal, and opposite the second VCSEL to collimate the orthogonally polarized optical data signal. A polarization division multiplexer may combine the first collimated polarized optical data signal and the second collimated orthogonally polarized optical data signal.

Abstract: A combination of a semiconductor member and a metal member is selected appropriately from a view point of increasing an enhancement factor of a near-field light. A device (1) has a semiconductor member (101) and a metal member (102), a near-field light is generated at the metal member when an energy is supplied to the semiconductor member, the metal member is made of an alloy including a first metal and a second metal, a condition of Rm1<Rs<Rm2 is satisfied, wherein a resonance wavelength of the first metal is Rm1, a resonance wavelength of the second metal is Rm2, and a resonance wavelength of the semiconductor member is Rs.

Abstract: Systems and techniques for compensation to improve write signal controls for magnetic-medium-based storage devices, include an apparatus comprising: pre-compensation circuitry coupled with a controller to receive a data signal and a write-current control signal and to generate a write-current signal; the pre-compensation circuitry is configured to use different baseline write-current levels for the write-current signal after an overshoot write-current level used at polarity transitions of the write-current signal, and the pre-compensation circuitry is configured use a first baseline level of the different baseline write-current levels for a first type of magnet in the sequence of magnets and use a second baseline level of the different baseline write-current levels for a second type of magnet in the sequence of magnets, the first baseline level having a greater magnitude than the second baseline level, and the first type of magnet being shorter than the second type of magnet.

Abstract: An optical disc device includes: an optical disc drive that reads data from a plurality of optical discs in which user data is recorded while distributed in the plurality of optical discs; a memory unit in which data read from an optical disc of a first group that is a part of the plurality of optical discs is recorded through the optical disc drive; and a controller that reproduces the user data from data of a remaining optical disc except for the first group, the data of the remaining optical disc being read through the optical disc drive, and the data recorded in the memory unit.

Abstract: Systems and techniques relating to voltage signal peak level detection used in sensor devices, namely in Fly-Height Sensors (FHS) devices include, according to an aspect, an integrated chip device comprising: peak detection circuitry configured to receive a voltage signal and output a peak voltage signal associated with a peak voltage level of the voltage signal, wherein the peak detection circuitry comprises: a linear loop section configured to store the peak voltage level and hold additional voltage levels of the voltage signal at an output terminal of an amplifier to a value greater than zero; and a feedback loop section configured to reduce a leakage current within the peak detection circuitry and generate a guard voltage signal usable to reduce a feedback voltage and prevent the feedback voltage from successively re-entering into the feedback loop section.

Abstract: In some implementations, a system includes a magnetic media disk and a read/write unit. The read/write unit includes a plurality of phase-locked loops (PLLs), an interpolator unit, a delay-locked loop, and a precompensation unit. The PLLs are configured to generate, using a reference clock signal, a first plurality of clock signals having different frequencies phases. The interpolator unit is configured to interpolate the first plurality of clock signals in accordance with a frequency offset signal to generate a single-phase clock signal. The delay-locked loop is configured to delay the single-phase clock signal in accordance with a PLL data clock signal to generate a second plurality of clock signals having different phases. The precompensation unit is configured to apply precompensation to the second plurality of clock signals to generate a timing signal for writing data to the magnetic media disk.

Abstract: A slider configured for heat-assisted magnetic recording has an upper surface, an opposing air bearing surface (ABS), and a body defined between the upper surface and the ABS. The slider comprises a write pole and a near-field transducer (NFT) at or near the ABS. An optical waveguide is configured to receive light from a laser source and comprises a first cladding layer, a second cladding layer, and a core between the first and second cladding layers. The core has a width, a length, and a longitudinal axis oriented along the length of the core. A bolometer is situated within the body of the slider at a location that receives at least some of the light communicated along the waveguide used during a writing operation. The bolometer is spaced apart from the core and comprises a longitudinal axis that is oriented substantially parallel to the longitudinal axis of the core.

Abstract: First tracks of a disk are read via a first read transducer. The first read transducer has a first crosstrack width and a first shield-to-shield spacing that are optimized to read a first track width and a first linear bit density of the first tracks. Second tracks interlaced between the first tracks are read via a second read transducer. The second read transducer has a second crosstrack width different from the first crosstrack width and second shield-to-shield spacing different than the first shield-to-shield spacing. The second crosstrack width and the second shield-to-shield spacing are optimized to read a second track width different from the first track width and a second linear bit density different from the first linear bit density.