International Business Machines Corporation

Hgst Netherlands, B.v.

Hitachi Global Storage Technologies Netherlands B.v.

Mayo Foundation for Medical Education and Research

Western Digital Technologies, Inc.

Omnitier Storage, Inc.

Jonathan Darrel Coker

Richard Leo Galbraith

Evangelos Stavros Eleftheriou

David Robison Hall

David Timothy Flynn

Roy Daron Cideciyan

Travis Roger Oenning

David James Stanek

Roger William Wood

Walter Hirt

Todd Carter Truax

Weldon Mark Hanson

Sharat Batra

Rick Allen Philpott

Srinivasan Surendran

Thomas R Albrecht

Bruce Alexander Wilson

Martin Aureliano Hassner

David R Holmes, Iii

Timothy A Schaefer

Pablo A Ziperovich

Kirk Hwang

Francois Bernard Dolivo

Yuval Cassuto

Edward Brian Welch

Donald Earl Vosberg

Gregory J Kerwin

Balamurugan Anandan

Timothy Joseph Chainer

Gordon James Smith

Thomas Mittelholzer

Mark Delorman Schultz

Zvonimir Z Bandic

Cyril Guyot

Ajay Dholakia

Marco Sanvido

Earl Albert Cunningham

Ricardo Ruiz

Frank Ray Keyser, Iii

Reto Josef Hermann

Richard Greenberg

Gary Allan Herbst

John Jeffrey Stephenson

Wolfgang H Schott

Robert Andrew Kertis

Thomas C Christensen

Shad Henry Thorstenson

Kevin Roy Vannorsdel

James Bowling French, Jr

Sridhar Chatradhi

Yaw-Shing Tang

Allen Prescott Haar

Timothy John Everett

Jeffrey L Furlong

Patrick C Arnett

Mark Andrew Bergquist

Dean C Palmer

Gary William Walker

Kei Akiyama

Stephanie Louise Aho

Gregory Scott Bush

Richard C Jaworski

Eric James Tree

Paul P Howard

Mark D Warne

Jeffrey R Roepke

Timothy M Schaefer

Dave James Stanek

Joel Dale Haugen

Neil Krishnaswamy

Steven Michael Currie

David R Iii Holmes

Richard A Philpott

A first string, having a first string value, that is associated with a sample set of material is received, wherein a second string, having a complementary value relative to the first string value, is also associated with the sample set of material. A determinative hash is generated using the first string value and a symmetric generator polynomial. A second hash, corresponding to the second string, is generated directly from the determinative hash. A canonized hash is generated using the determinative hash and the second hash. It is determined whether at least one of the first string or the second string is stored in string storage that is configured to store a plurality of strings, including by searching a hash table for the canonized hash; in the event it is determined that at least one of the first string or the second string is not stored in the string storage, at least one of the first string or the second string is stored in the string storage.

Reversible hash generators for pairs of complementary sequences

A first string, having a first string value, that is associated with a sample set of material is received where a second string, having a complementary value relative to the first string value, is also associated with the sample set of material. A reversible hash generator is used to generate a determinative hash using the first string value, where a second hash, corresponding to the second string, is able to be determined directly from the determinative hash and without the reversible hash generator processing the complementary value of the second string. It is determined whether at least one of the first string or the second string is stored in a memory using the determinative hash.

A system according to one embodiment includes a magnetic head having a plurality of sensors arranged to simultaneously read at least three immediately adjacent data tracks on a magnetic medium, wherein none of the sensors share more than one lead with any other of the sensors. Such embodiment may be implemented in a magnetic data storage system such as a disk drive system, which may include a magnetic head, a drive mechanism for passing a magnetic medium (e.g., hard disk) over the magnetic head, and a controller electrically coupled to the magnetic head.

Multi-track reader for improved signal to noise ratio

A disk drive includes a controller and at least one disk, which may include a first I-region, a second I-region, and an E-region. The first and second I-region may have a first final logical block address (LBA) and a second final LBA, respectively. The controller may be configured to cause information to be written to the first I-region and the second I-region using a first type and a second type of magnetic recording, respectively. The controller also may be configured to set at least one of the first final LBA or the second final LBA to a final LBA value higher than the at least one of the first final LBA or the second final LBA, respectively, after writing user data to at least a portion of the first I-region or the second I-region and without removing the user data.

Disk drive including I-regions having configurable final logical block addresses

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.

In general, techniques are described for writing data to a storage device that comprises an interface and a controller. The interface may receive a request to sequentially write data stored in a first group of tracks to an I-region, where the first group of tracks was also previously written. The controller may move data stored in a second group of consecutive tracks different than the first group of tracks from the I-region to an E-region, the second group having cardinality equal to the tracks that must be moved for the first group to be written sequentially in the I-region. The E-region comprises a portion of the storage device reserved for temporary storage. The controller may determine a position of the I-region where data from one of the second group was previously stored, and write data from the first group of tracks sequentially to the I-region, starting at the position.

Atomic write-in-place for hard disk drives

The present invention generally relates to a read head in a magnetic recording head. The read head utilizes two reader elements that are stacked in the down track direction within the same read gap to improve resolution and SNR by combining the signals from the two reader elements. The output waveform from each read element is asymmetric in the down track direction; however, by use of equalizer settings and waveform combining the algorithm in signal processing, the combined waveform has a similar or better resolution and higher SNR compared to a single read element in a smaller read gap.

Multiple readers for high resolution and SNR for high areal density application

Disk drives are described in which blocks of data spanning multiple sectors are encoded into a plurality of codewords which are then divided into segments that are physically separated (distributed) on the disk surface over multiple sectors in a distributed codeword block so that the codewords have an improved worst case SNR in comparison to individual sectors. This results in more even SNR performance for each codeword, which improves the performance for portions of a track which have lower than the average SNR. Embodiments are described in which the distributed codeword blocks span across tracks.

Disk drive with distributed codeword blocks

A method of correcting repeatable run out (RRO) errors for a HDD in which RRO data is instead stored in consolidated form within the reserved area of the disk, instead of storing RRO data in the servo patterns for each HDD track or sector. RRO data is preferably stored in the reserved area of a hard disk drive in compressed form. The compressed RRO data is subsequently read into DRAM in compressed form and then decompressed for use. Predictive techniques determine what compressed RRO data is needed for upcoming read/write operations.

Method of compensating for repeatable runout error

A hard disk drive has disks with data sector preambles that allow for inter-track interference. The same data sector preamble is used for all data sectors in a track but the preamble in each track is different from the preamble in radially adjacent tracks. In a first embodiment each preamble includes a synchronization field (SF) and synchronization mark (SM) that are the same in each track but different from the SF and SM in radially adjacent tracks. Only two unique SFs and two unique SMs are required, with the two SFs and two SMs alternating in radially adjacent tracks. In a second embodiment the preambles are 'integrated', meaning that the preamble is a sequence of bits that does not include separate dedicated fields, like SF and SM. The preamble bit sequences are decoded using matched filters to provide bit synchronization and start-of-data information.

Disk drive with different data sector integrated preambles in adjacent data tracks

Disk drive with different synchronization fields and synchronization marks in the data sector preambles in adjacent data tracks

A receiver utilizes a plurality of read elements, each generating a read-back signal in response to a data track positioned beneath the read element. The plurality of read-back signals are each provided to at least one space-time interference cancellation filter, which generates a filtered output that maximizes a signal associated with one of the plurality of data tracks. The filtered output is provided to a one-dimensional Viterbi detector, which is configured to generate in response an output representative of a data sequence written to one of the plurality of data tracks.

Low complexity inter-track interference cancellation receiver for magnetic multiple-input, multiple-output (MIMO) channel

A disk drive includes an environmental monitor, a controller and a writing mechanism. The controller acts in response to an output from the environmental monitor to determine if the data capacity of a disk drive could be increased from a first value to a second value. The controller determines the second increased value. The writing mechanism, controlled by the controller, writes data to the disk to realize the increased data capacity of the disk drive. A method for increasing the data capacity of a disk drive from the factory settings for data capacity includes determining if the disk drive is in a favorable or stable environment, writing data to at least one portion of the disk drive at a higher capacity than the factory setting for the at least one portion of the disk drive, and resetting the capacity for at least one portion of the disk drive.

Dynamic variable capacity hard disk drive

Growing community of inventors

Rochester, MN, United States of America

Jonathan Darrel Coker