Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

International Business Machines Corporation

Western Digital Technologies, Inc.

Other

David Timothy Flynn

Jonathan Darrel Coker

Richard Leo Galbraith

Gary Allan Herbst

Weldon Mark Hanson

Niranjay Ravindran

Thomas R Albrecht

Iouri Oboukhov

James Bowling French, Jr

Timothy John Everett

Timothy Joseph Chainer

Mark Delorman Schultz

Bruce Alexander Wilson

Earl Albert Cunningham

Travis Roger Oenning

Xiao Z Wu

Mark David Hagen

Michael Anthony Moser

Zarko Popov

Yuval Cassuto

Thomas C Christensen

Todd Carter Truax

James B French, Jr

Jodie Ann Christner

Mark Andrew Bergquist

Hiroyasu Masuda

Neil Krishnaswamy

Jonathan Darrell Coker

Joel Dale Haugen

Various illustrative aspects are directed to a data storage device comprising data tracks N and N−1, and one or more processing devices, configured to identify, during a track write on the data track N, a write abort event based upon an expected risk for the data track N−1 exceeding a risk threshold, read one or more sectors of the data track N−1 and collect one or more corresponding sector metrics, verify the one or more sectors based upon the collected sector metrics, wherein the verifying comprises assigning each of the one or more sectors as one of a readable or a non-readable sector, and continue the track write on the data track N upon determining each of the one or more sectors is a readable sector, or recovering and relocating the data track N−1 based on determining at least one of the sectors is a non-readable sector.

Sector metrics to estimate health of written data

A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of servo sectors defining a plurality of data tracks, wherein each servo sector comprises a track ID followed by a sync mark followed by at least one servo burst, and a first servo sector does not include a preamble. During a read operation, a servo gate is opened in order to read the track ID, the sync mark, and the servo burst of the first servo sector. During a write operation, the servo gate is opened in order to miss reading at least part of the track ID of the first servo sector so as to reduce a write gap preceding the first servo sector.

Data storage device eliminating preamble from servo sectors

A data storage device is disclosed comprising a head actuated over a disk. A first plurality of codewords and corresponding parity sector are generated, and a second plurality of codewords and corresponding parity sector are generated. The first and second plurality of codewords are written to the disk, and during a read of the first and second set of codewords, M codeword locations within the data track that are unrecoverable are saved, and N codeword locations out of the M codeword locations are selected based on a quality metric of the read. The N codewords are reread from the data track at the N codeword locations and reliability metrics associated with the N codewords are saved. The saved reliability metrics are updated using at least one of the first parity sector or the second parity sector.

Data storage device employing multi-level parity sectors for data recovery procedure

A data storage device is disclosed wherein a first plurality of codewords are generated each comprising a plurality of symbols, and a first parity sector is generated over the first plurality of codewords. A second plurality of codewords are generated each comprising a plurality of symbols, and a second parity sector is generated over the second plurality of codewords. A third parity sector is generated over a first subset of the first plurality of codewords and a first subset of the second plurality of codewords, and a fourth parity sector is generated over a second subset of the first plurality of codewords and a second subset of the second plurality of codewords. When processing of a first codeword fails, the first codeword and the first parity sector are processed using a LDPC type decoder, and the first codeword and the third parity sector are processed using the LDPC type decoder.

A dual configuration headrest system includes a seat having a top side and a back edge. A backrest is attached to the seat and extends upwardly from the top side. A housing is attached the backrest and is positioned over an upper edge of the backrest. The housing has a top wall, a bottom wall, first lateral wall and a second lateral wall. A front side of the housing is open. A head support is mounted within the housing and has a first side and a second side positioned opposite of each other. The head support further has a top side, a bottom side, a first lateral side and a second lateral side. The head support is rotationally mounted within the housing such that the first side or the second side is positioned in an opening in the front side when the head support is rotated relative to the housing.

Dual configuration headrest system

An embodiment of the present invention implements some or all major servo subfunctions for a storage device in integrated servo fields comprising sequences of encoded bits having selected mathematical properties. The integrated servo field is composed of a number of encoded sequences, which are members of a selected sequence set that is constrained to preferably provide some or all of the following functions: the Servo Track Mark (STM), the Position Error Signal (PES) and location information such as the track-ID. The juxtaposition of sequences in the servo wedges is additionally constrained to increase the detectability of the contribution of adjacent sequences in the read signal. The integrated servo fields can provide a Position Error Signal (PES) in relation to the center of a data track through the amplitude of the signal read for adjacent sequences.

Information storage device with multiple-use fields in servo pattern

An embodiment of the present invention implements some or all major servo subfunctions for a storage device in integrated servo fields comprising sequences of encoded bits having selected mathematical properties. The integrated servo field is composed of a number of encoded sequences, which are members of a selected sequence set that is constrained to preferably provide some or all of the following functions: the Servo Track Mark (STM), the Position Error Signal (PES) and positional information such as the track-ID. The integrated servo fields can provide a Position Error Signal (PES) in relation to the center of a data track through the amplitude of the signal read for adjacent sequences. The servo system detects the sequences in the signal from the read head using a set of digital filters for the set of encoded sequences.

Disk drives are described that include a hybrid servo patterns in which the augmented servo burst fields, which can be Integrated Servo sequences, that provide the PES and also supply additional information such as a SAM, LSBs of the track identifier (TID), sector number, depending on the specific embodiment. Embodiments without write-to-read gaps before the servo sector SIDs are described. The augmented servo burst fields can be read after gapless writing of the preceding data area. For seeking operations the needed bits of the TID without having to detect or decode the Integrated Servo sequences or other augmented servo burst fields. Depending on the embodiment all or the most significant bits of the track identifier can be obtained during seeks by reading the TID fields passing under a read head as the read head moves across tracks without having to detect or decode the Integrated Servo sequences.

Servo systems with augmented servo bursts

Pre-patterned discrete track media for self-servo writing are described. Embodiments include land and groove patterns for two or more Integrated Servo sequence fields for each servo sector in which one of the Integrated Servo sequence fields is aligned with the data track and a second sequence is offset by one-half of a track width. The lands and grooves between the Integrated Servo sequence fields are preferably the same width as those between the data tracks to facilitate planarization. Alternative embodiments include a sync feature for each servo sector formed by a selected groove and/or land pattern as a marker for the start of the servo fields. Alternative embodiments include a bootstrap zone with servo patterns that are readable when DC-magnetized. Described methods of self-servowriting include ways to adapt to eccentricity and non-circularity of pre-patterned discrete tracks with respect to the head paths.

Patterned media for self-servowriting integrated servo fields

An embodiment of the present invention implements some or all major servo subfunctions for a storage device in integrated servo fields comprising sequences of encoded bits having selected mathematical properties. The integrated servo field is composed of a number of encoded sequences, which are members of a selected sequence set that is constrained to preferably provide some or all of the following functions: the Servo Track Mark (STM), the Position Error Signal (PES) and positional information such as the track-ID. In one embodiment the plurality sequences encoding a location identifier such as a track-ID are distributed across a set of servo wedges. A method of encoding the location identifier using a Chinese Remainder Theorem is described.

A magnetic recording disk drive has a position-error-signal (PES) servo pattern divided into at least two circumferentially adjacent fields that extend radially across the data tracks and include PES blocks that are DC magnetized in one direction, with each PES block having a magnetization opposite to the magnetization of its radially adjacent neighboring PES blocks. Each PES field is contiguous with and shifted radially relative to its circumferentially adjacent neighbor PES fields. Each PES block has a single DC magnetization, and the length of the magnetization is substantially longer than the length of the magnetizations in the other fields of the servo pattern.

Magnetic recording disk and disk drive with alternating single-polarity position error signal (PES) blocks for read/write head positioning

A system and method accurately clocks write data to the discrete data blocks in a patterned media disk drive. The precise time intervals between successive timing marks in the data tracks are measured by a timing mark detector that counts the integer number of write clock cycles between successive timing marks and the fractional part of a write clock cycle by detecting the phase difference between a timing mark and a reference signal. The resulting timing error is output to a write clock compensator. The write clock is capable of generating equally spaced primary phases and phases intermediate the primary phases. The compensator includes a phase rotator that controls which write clock phase is selected for output. The value in a phase register of the compensator is used to control the phase rotator to advance or retard the write clock phase, and thus to adjust its frequency and phase so as to be synchronized for writing to the data blocks.

Magnetic recording disk drive with patterned media and system for clocking write data

Write control bits are associated with servo pattern data bits to selectively disable or enable a write gate in a HDD write channel for self-servo writing after being sealed but before being vended to a user. The write gate can be disabled and enabled without deenergizing the write channel. A single write delay is calculated from one timing mark to the next to enable writing the next timing mark and portions of the radial pattern and servo pattern between the timing marks.

System and method for writing servo track in sealed HDD

A hard disk drive (HDD) holds data using a biphase scheme. A plurality of matched filters are used to detect binary data represented by the biphase pattern without the need for synchronous sampling or equalization.

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Mantorville, MN, United States of America

David Timothy Flynn