General Processing Of A Digital Signal Patents (Class 360/39)
  • Patent number: 10353624
    Abstract: A method for writing data in a buffer to a magnetic recording tape includes identifying a size of an unused area of the magnetic recording tape based on a current writing position on the magnetic recording tape. An upper limit of a capacity for data that can be stored in the buffer is determined based on the size of the unused area. The predetermined data is stored, according to a command for storing predetermined data in the buffer, in the buffer on condition that the capacity for data in the buffer does not exceed the upper limit.
    Type: Grant
    Filed: July 29, 2015
    Date of Patent: July 16, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Yutaka Oishi
  • Patent number: 10319400
    Abstract: A method includes moving a heat-assisted magnetic recording (HAMR) slider relative to a magnetic recording medium. The slider comprises a writer, a writer heater, and a near-field transducer (NFT). For each of a plurality of different head-to media spacings a test tone is written to a track of the medium, the test tone is read and a Discrete Fourier Transform (DFT) of an amplitude of the read test tone is captured. A first DFT curve is generated at a beginning of writing the test tones. A second DFT curve is generated at a saturated state of writing the test tones. An amount of horizontal shift between the first and second DFT curves is computed. The amount of horizontal shift corresponding to writer heater power required to compensate for NFT clearance offset due to laser induced writer protrusion.
    Type: Grant
    Filed: August 17, 2018
    Date of Patent: June 11, 2019
    Assignee: Seagate Technology LLC
    Inventors: Zhen Wei, Hua Liu
  • Patent number: 10321424
    Abstract: A method and nodes for wireless timing synchronization of a target node and a source node. In some embodiments, a request is sent to a source node for time synchronizing the target node with the source node. A first time, T1, indicative of time of transmission of a first radio signal from the source node to the target node is determined. A second time, T2, indicative of time of receipt of the first radio signal at the target node is determined. A third time, T3, indicative of time of transmission of a second radio signal from the target node to the source node is determined. A fourth time, T4, indicative of time of receipt of the second radio signal at the source node is determined. A clock offset based on T1, T2, T3 and T4 for use in time synchronizing the target node with the source node is determined.
    Type: Grant
    Filed: July 17, 2015
    Date of Patent: June 11, 2019
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Chunhui Zhang, Angelo Centonza, Garry Irvine, Mikael Olofsson, Magnus Sandgren
  • Patent number: 10311897
    Abstract: First and second tracks of a magnetic recording medium are read simultaneously via a first reader that provides a first signal based on detecting a total perpendicular field of the first and second tracks. The first and second tracks are read simultaneously via a second reader that provides a second signal based on detecting a total longitudinal field of the first and second tracks. Data is detected from the first and second signals.
    Type: Grant
    Filed: July 30, 2018
    Date of Patent: June 4, 2019
    Assignee: Seagate Technology LLC
    Inventors: Walter R. Eppler, Mehmet Fatih Erden, Stephanie Hernandez
  • Patent number: 10304471
    Abstract: An audio signal (X) is represented by a bitstream (B) segmented into frames. An audio processing system (500) comprises a buffer (510) and a decoding section (520). The buffer joins sets of audio data (D1; D2, . . . , DN) carried by N respective frames (F1, F2, . . . , FN) into one decodable set of audio data (D) corresponding to a first frame rate and to a first number of samples of the audio signal per frame. The frames have a second frame rate corresponding to a second number of samples of the audio signal per frame. The first number of samples is N times the second number of samples. The decoding section decodes the decodable set of audio data into a segment of the audio signal by at least employing signal synthesis, based on the decodable set of audio data, with a stride corresponding to the first number of samples of the audio signal.
    Type: Grant
    Filed: October 23, 2015
    Date of Patent: May 28, 2019
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Alexander Groeschel, Heiko Purnhagen, Holger Hoerich, Kurt Krauss
  • Patent number: 10270445
    Abstract: A semiconductor device includes a clock divider that receives a clock signal and generates even and odd clock signals. The clock signal includes a first frequency, while the even and odd clock signals each includes a second frequency that is half the first frequency. The semiconductor device also includes even and odd command paths coupled to the clock divider each having a set of logic and a set of flip-flops. The even command path receives a command and the even clock signal and outputs an even output signal. The odd command path receives the command and the odd clock signal and outputs an odd output signal. The semiconductor device also includes combination circuitry coupled to the even and odd command paths that combines the even and odd output signals.
    Type: Grant
    Filed: June 20, 2018
    Date of Patent: April 23, 2019
    Assignee: Micron Technology, Inc.
    Inventor: Kallol Mazumder
  • Patent number: 10157637
    Abstract: Systems and methods are disclosed for sampling signals in multi-reader magnetic recording. In certain embodiments, an apparatus may comprise a plurality of read heads configured to simultaneously read from a single track of a storage medium, a plurality of analog to digital converters (ADCs) configured to receive signal patterns from corresponding read heads, and a circuit configured to control the plurality of ADCs to sample the signal patterns according to a single clock signal generator. The output of the ADCs may be individually delayed based on a down-track offset of the read heads in order to align the samples, so that samples corresponding to the same portion of the recorded signal can be combined for bit pattern detection.
    Type: Grant
    Filed: October 2, 2017
    Date of Patent: December 18, 2018
    Assignee: Seagate Technology LLC
    Inventors: Marcus Marrow, Jason Bellorado, Zheng Wu
  • Patent number: 10108470
    Abstract: Apparatuses, systems, methods, and computer program products are disclosed for parity storage management. A system includes a plurality of storage elements. A system includes a controller that selects a parity storage element from a plurality of storage elements. A parity storage element has an error rate higher than other elements of a plurality of storage elements, and the parity storage element stores parity data for the plurality of storage elements.
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: October 23, 2018
    Assignee: SanDisk Technologies LLC
    Inventors: Gulzar A. Kathawala, Shuenghee Park, Jingfeng Yuan, Mark Dancho
  • Patent number: 10109314
    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.
    Type: Grant
    Filed: March 7, 2018
    Date of Patent: October 23, 2018
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
    Inventor: Manabu Kobayashi
  • Patent number: 10102869
    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.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: October 16, 2018
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
    Inventors: Kazuya Takada, Kenji Yoshida
  • Patent number: 10068597
    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.
    Type: Grant
    Filed: January 17, 2018
    Date of Patent: September 4, 2018
    Assignee: Seagate Technology LLC
    Inventors: Jason Charles Jury, Steven Douglas Granz
  • Patent number: 10063234
    Abstract: A semiconductor device includes a clock divider that receives a clock signal and generates even and odd clock signals. The clock signal includes a first frequency, while the even and odd clock signals each includes a second frequency that is half the first frequency. The semiconductor device also includes even and odd command paths coupled to the clock divider each having a set of logic and a set of flip-flops. The even command path receives a command and the even clock signal and outputs an even output signal. The odd command path receives the command and the odd clock signal and outputs an odd output signal. The semiconductor device also includes combination circuitry coupled to the even and odd command paths that combines the even and odd output signals.
    Type: Grant
    Filed: July 13, 2017
    Date of Patent: August 28, 2018
    Assignee: Micron Technology, Inc.
    Inventor: Kallol Mazumder
  • Patent number: 10026431
    Abstract: This disclosure relates to a memory device that includes at least one magnetic track on a substrate, wherein the at least one magnetic track comprises one or more magnetic domains. Contacts can be disposed on the at least one magnetic track according to a predetermined arrangement to form a plurality of bitcells on the at least one magnetic track, wherein each one of the plurality of bitcells is configured to store at least one magnetic domain. The device can include a timing circuit connected to the contacts, with the timing circuit being configured to apply to the contacts multiple phases of electric currents according to a predetermined timing sequence to cause the at least one magnetic domain to shift from the each one of the plurality of bitcells to an adjacent one of the plurality of bitcells on the at least one magnetic track.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: July 17, 2018
    Assignee: Carnegie Mellon University
    Inventors: David M. Bromberg, Lawrence Pileggi, Jian-Gang Zhu
  • Patent number: 10026474
    Abstract: Switched memristor analog tuning employs a switch-selectable programmed resistance to tune a resistance-tunable analog circuit. A plurality of switched memristors is to provide the switch-selectable programmed resistance. The resistance-tunable analog circuit is connected to the plurality of switched memristors. The switch-selectable programmed resistance is to tune an analog attribute of the resistance-tunable analog circuit.
    Type: Grant
    Filed: April 26, 2014
    Date of Patent: July 17, 2018
    Assignee: Hewlett Packard Enterprise Development LP
    Inventor: Brent Buchanan
  • Patent number: 10026441
    Abstract: The present disclosure relates to a method and apparatus for processing of multi-dimensional readback signal from magnetic recording or optical, physical data recording so as to reduce/control Inter Symbol Interference (ISI) and noise within acceptable limits. The method is based on Partial Response Maximum Likelihood (PRML) detection and takes care of time varying channel conditions. In an embodiment, the filter coefficients of both the equalizer and the partial response (PR) target are jointly adapted to account for the channel condition for both separable and non-separable targets thus reducing signal detection complexity. In an aspect, the disclosure provides an apparatus that incorporates an adaptation engine along with the equalizer and the PR target that updates filter coefficients of both the equalizer and the PR target following the formulated mathematical equations.
    Type: Grant
    Filed: July 13, 2017
    Date of Patent: July 17, 2018
    Assignee: INDIAN INSTITUTE OF SCIENCE
    Inventors: Shayan Srinivasa Garani, Chaitanya Kumar Matcha, Arnab Dey
  • Patent number: 10020012
    Abstract: First and second servo control processors are coupled to respective first and second actuators that independently position first and second heads over one or more disks of a data storage drive. The first and second servo control processors are further coupled to first and second low-latency ports. First and second unidirectional buses couple the first and second low-latency ports. The first and second unidirectional busses are operable to isochronously exchange servo positioning data between the first and second servo control processors. The first and second servo control processors each use the servo positioning data to compensate for movement caused by another of the first and second servo control processors.
    Type: Grant
    Filed: October 31, 2017
    Date of Patent: July 10, 2018
    Assignee: Seagate Technology LLC
    Inventors: Aaron P. Weyer, Bruce Douglas Buch, Kyaw Sin Maung, Jon D. Trantham, Nicholas Paul Mati
  • Patent number: 9979155
    Abstract: A drive circuit of a light emitting element, the drive circuit includes: an input terminal configured to receive an input signal; an output terminal configured to output a signal based on the input signal as a drive signal to the light emitting element; and a main body circuit configured to generate the drive signal by carrying out timing correction to reduce a difference from a standard delay value for rising or falling of a plurality of signal patterns of the input signal regarding a timing of rising of a first signal subsequent to a first signal pattern in the plurality of signal patterns or a timing of falling of a second signal subsequent to a second signal pattern in the plurality of signal patterns.
    Type: Grant
    Filed: December 14, 2016
    Date of Patent: May 22, 2018
    Assignee: FUJITSU LIMITED
    Inventor: Yukito Tsunoda
  • Patent number: 9899053
    Abstract: Method and apparatus for data security in a data storage device. In some embodiments, a first version of firmware is installed in a memory of the device. The firmware is used by a programmable processor to control accesses to a rotatable data recording medium on which is written pre-recorded servo positioning data used to position a data transducer. A newer, second version of the firmwave is subsequently installed in the memory to replace the first version of firmware. The second version of the firmware includes an instruction to corrupt a selected portion of the servo positioning data on the medium in order to authenticate the second version of the firmware. During a subsequent initialization of the device, host access is granted based on detection of the corruption of the selected portion of the servo positioning data.
    Type: Grant
    Filed: October 11, 2016
    Date of Patent: February 20, 2018
    Assignee: Seagate Technology LLC
    Inventors: Leroy L. Leach, Todd D. Baumann
  • Patent number: 9899056
    Abstract: A computer-implemented method, according to one embodiment, includes, performing anti-aliasing filtering on each of a plurality of symmetrical square wave signals, each symmetrical square wave signal having a frequency that is a different fraction of a frequency of a data read clock. The filtered symmetrical square wave signals are passed through a band pass filter. An amplitude of each of the symmetrical square wave signals is measured after the band pass filtering. In response to the amplitudes of the symmetrical square wave signals being within a predefined range, anti-aliasing settings used during the anti-aliasing filtering are stored. In response to the amplitudes of the symmetrical square wave signals being outside the predefined range, the anti-aliasing settings are changed.
    Type: Grant
    Filed: May 23, 2017
    Date of Patent: February 20, 2018
    Assignee: International Business Machines Corporation
    Inventors: Larry L. Tretter, Matthew M. Viens
  • Patent number: 9886970
    Abstract: In certain embodiments, an apparatus may comprise a first output driver connected to a first output via a first trace and a second output driver connected to a second output via a second trace. The first output driver may be configured to output a first drive signal to the first output to drive the first output and the first drive signal may cause first induced noise in the second trace. Further, the second output driver may be configured to output a second drive signal based on the first drive signal where the second drive signal may reduce the magnitude of the first induced noise at the second output.
    Type: Grant
    Filed: September 1, 2016
    Date of Patent: February 6, 2018
    Assignee: Seagate Technology LLC
    Inventors: Todd Michael Lammers, JianHua Xue, Javier I Guzman, Andrew Thomas Jaeb, Bruce Douglas Buch
  • Patent number: 9882577
    Abstract: There is disclosed herein charge-mode circuitry for use in a comparator to capture a difference between magnitudes of first and second input signals, the circuitry comprising: a tail node configured during a capture operation to receive a charge packet; first and second nodes conductively connectable to said tail node along respective first and second paths; and control circuitry configured during the capture operation to control such connections between the tail node and the first and second nodes based on the first and second input signals such that said charge packet is divided between said first and second paths in dependence upon the difference between magnitudes of the first and second input signals.
    Type: Grant
    Filed: March 10, 2017
    Date of Patent: January 30, 2018
    Assignee: SOCIONEXT INC.
    Inventors: Ian Juso Dedic, Prabhu Ashwin Harold Rebello, John James Danson
  • Patent number: 9858962
    Abstract: According to one embodiment, there is provided a disk apparatus including a disk medium and a controller. The disk medium is able to store a signal with three levels in a track. The track includes a first subtrack and a second subtract. The second subtrack is adjacent to the first subtract. The controller performs a first operation based on a selected level among the three levels, a first bit written in the first subtract corresponding to the selected level, and a second bit written in the second subtrack corresponding to the selected level. The first operation is an operation to correct displacement between a write position of a third bit in the first subtrack and a write position of a fourth bit in the second subtrack in a circumferential direction of the disk medium.
    Type: Grant
    Filed: March 3, 2017
    Date of Patent: January 2, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tomokazu Okubo
  • Patent number: 9841916
    Abstract: A memory system includes a plurality of channels; a plurality of semiconductor memory devices connected to the channels; and a controller that controls the semiconductor memory devices through the channels, wherein the controller writes program data in a first semiconductor memory device of the plurality of semiconductor memory devices, and wherein, when the writing of the program data fails, the program data is temporarily stored in a page buffer unit of a second semiconductor memory device of the plurality of semiconductor memory devices connected to a channel other than the channel corresponding to the first semiconductor memory device.
    Type: Grant
    Filed: December 2, 2015
    Date of Patent: December 12, 2017
    Assignee: SK Hynix Inc.
    Inventor: Sung Yeob Cho
  • Patent number: 9824703
    Abstract: According to one embodiment, a magnetic recording and reproducing device includes a magnetic recording medium, a magnetic head, and a processor. The magnetic head includes a first reproducing element portion and a second reproducing element portion. The processor is configured to acquire a first signal and a second signal, and to output an output signal according to either one of the first signal and the second signal. The first signal is obtained by reproducing information recorded on a first recording region by the first reproducing element portion. The second signal is obtained by reproducing the information recorded on the first recording region by the second reproducing element portion.
    Type: Grant
    Filed: September 7, 2016
    Date of Patent: November 21, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuya Sugawara, Tomoyuki Maeda, Kenichiro Yamada
  • Patent number: 9823987
    Abstract: Implementations disclosed herein provide a method comprising iteratively reading data from a failing media sector prior to a an error minimization operation, analyzing read data at each iteration using an error minimization operation to determine sections of read data as good data, storing the good data in a buffer during each iteration, and using the good data as input for the read data during a subsequent error retry operation. In another implementation, the method further comprises comparing new read data with stored good data in the buffer, and replacing the stored good data with the new read data if the new read data has a higher quality than the stored good data.
    Type: Grant
    Filed: October 2, 2015
    Date of Patent: November 21, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Mingyeong Son, Seungyoul Jeong, Seokhun Jeon
  • Patent number: 9818445
    Abstract: Implementations described and claimed herein includes a storage device comprising a plurality of readers, including a first subset of readers configured to read a first subset of tracks and a second subset of readers configured to read a second subset of tracks, the first subset of tracks being wider than the second subset of tracks. In another implementation, the readers in the first subset of readers are wider than the readers in the second subset of readers. The wider readers may be configured to recover servo information and the narrow readers may be configured to recover data information. The storage devices may include two-dimensional magnetic recording, conventional perpendicular magnetic recording, shingled magnetic recording, multi-sensor magnetic recording, and interlaced magnetic recording.
    Type: Grant
    Filed: January 12, 2016
    Date of Patent: November 14, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Wenzhong Zhu, Mehmet F. Erden, Kenneth A. Haapala, Wei Tian, Edward Gage
  • Patent number: 9786319
    Abstract: This disclosure describes codes and techniques for magnetic recording. The coding schemes decrease bit error rates by decreasing total transitions in the encoded binary data compared to conventional codes. Additionally, instead of relying on a single coding scheme, an encoder and decoder are configured to switch between different coding schemes. By so doing, a variety of the coding schemes allows the encoded binary data to have a smaller bit error rate than a single coding scheme and have a maximum run-length less than or equal to a maximum run-length limitation of a magnetic disk.
    Type: Grant
    Filed: March 8, 2017
    Date of Patent: October 10, 2017
    Assignee: Marvell International Ltd.
    Inventors: Seyed Mehrdad Khatami, Gregory Burd, Byung-Hak Kim
  • Patent number: 9747161
    Abstract: The invention provides a signal processing device, including: an extraction section that extracts, from an input digital signal, a decoding target signal at an extraction timing that has been determined as a timing for extracting the decoding target signal; a decoding section that decodes the decoding target signal by estimating, by a maximum likelihood decoding, a candidate for a decoding result of the decoding target signal extracted by the extraction section and detecting a maximum likelihood decoding result; and an adjustment section that adjusts the extraction timing using a likelihood of the candidate for the decoding result estimated by the decoding section.
    Type: Grant
    Filed: October 27, 2015
    Date of Patent: August 29, 2017
    Assignee: FUJIFILM CORPORATION
    Inventors: Atsushi Musha, Osamu Shimizu
  • Patent number: 9733859
    Abstract: A method, computer program product, and system for dividing a file and writing the file to a plurality of tapes in a tape library system comprising a plurality of tape apparatuses. A request to write a file to a plurality of tapes is received. The file comprises data. A number of available tapes is predicted with respect to a number of drives available at a time when the file requested to be written is written to the plurality of tapes. The data of the file is divided into a predetermined number of segments to reduce a time period for reading the file. The predetermined number of segments is based on the predicted number of tape drives. The data segments are written to the available tape drives.
    Type: Grant
    Filed: November 9, 2015
    Date of Patent: August 15, 2017
    Assignee: International Business Machines Corporation
    Inventors: Tohru Hasegawa, Masayuki Iwanaga, Yutaka Oishi
  • Patent number: 9728206
    Abstract: A storage device includes a transducer head including a first write element configured to write data at a first write width and a second write element configured to write data at a second write width less than the first write width. According to one implementation, the first write element writes data at a first linear density and to alternating data tracks and the second write element writes data at a second linear density and to data tracks interlaced with the alternating data tracks.
    Type: Grant
    Filed: April 14, 2015
    Date of Patent: August 8, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Kaizhong Gao, Wenzhong Zhu, Edward Gage
  • Patent number: 9728221
    Abstract: This application includes systems and techniques relating to storage devices, such as a device including: a first read channel to process a first input signal obtained from a storage medium using a first read head; a second read channel to process a second input signal obtained from the storage medium using a second read head, which is offset from the first read head in each of two dimensions; a single digital timing loop configured to control interpolation of timing of sampling for first and second analog to digital converters in the first and second read channels; and a two dimensional equalizer coupled with output lines of the first and second read channels; the device being configured to account for a fractional timing difference between the first input signal and the second input signal, the fractional timing difference being a fractional amount of a single clock cycle of the device.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: August 8, 2017
    Assignee: Marvell World Trade Ltd.
    Inventors: Mats Oberg, Nitin Nangare
  • Patent number: 9679597
    Abstract: An apparatus and method involves a writer configured for heat-assisted magnetic recording of data to a magnetic storage medium. A controller is coupled to the writer. The controller and writer are configured to write data to a plurality of concentric bands of the medium each comprising a plurality of partially overlapping narrow data tracks and a wide track. The wide tracks of successive bands are positioned adjacent to one another with no intervening narrow data track therebetween.
    Type: Grant
    Filed: July 8, 2016
    Date of Patent: June 13, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Wenzhong Zhu, Alfredo Sam Chu
  • Patent number: 9666213
    Abstract: In response to a command to update a target track, two tracks or more are concurrently read. The two tracks or more tracks include a top track that partially overlaps the target track. Data of the top track is stored in a memory, and the update data is written over at least part of the target track. The stored data is written on the recording medium over the top track or at a different location.
    Type: Grant
    Filed: June 29, 2016
    Date of Patent: May 30, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Mehmet Fatih Erden, Steven Douglas Granz
  • Patent number: 9640217
    Abstract: Systems and methods relating generally to determining flaws on a storage medium.
    Type: Grant
    Filed: November 30, 2015
    Date of Patent: May 2, 2017
    Assignee: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
    Inventor: Jefferson Singleton
  • Patent number: 9607642
    Abstract: An AC signal having a specified frequency and a DC offset voltage is applied to a slider substrate or a magnetic recording medium. A low- or non-modulation interface is defined between the slider and medium. In response to applying the AC signal, an oscillation in an electrostatic force occurs between the slider and the medium at the specified frequency, which causes an oscillation in thermal sensor signal at the slider, which oscillates at the specified frequency. A heater of the slider is adjusted to decrease spacing between the slider and medium during oscillation of the electrostatic force. For each heater adjustment, thermal sensor resistance is measured over a specified number of medium revolutions. Head-medium contact is detected using one of an amplitude of a harmonic of the thermal sensor signal and a summation of amplitudes of all frequency components at the specified frequency.
    Type: Grant
    Filed: January 27, 2016
    Date of Patent: March 28, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Won Choul Yang, Jin Pil Kim, Shi Jung Kim
  • Patent number: 9576594
    Abstract: A computer-implemented method, according to one embodiment, includes: receiving a first output signal from a write driver, the write driver having an operating voltage applied thereto, receiving a second output signal from a comparator circuit, the comparator circuit having a reference voltage applied thereto, comparing a voltage of the first output signal with a voltage of the second output signal, and detecting a high resistance condition in response to determining that the voltage of the first output signal is less than the voltage of the second output signal. According to the present embodiment, the high resistance condition indicates open and/or partially open circuitry in the write driver. Moreover, the operating voltage is equal to the reference voltage. Other systems, methods, and computer program products are described in additional embodiments.
    Type: Grant
    Filed: April 26, 2016
    Date of Patent: February 21, 2017
    Assignee: International Business Machines Corporation
    Inventor: Larry L. Tretter
  • Patent number: 9570105
    Abstract: Systems and methods are disclosed for data processing, and more particularly for equalizing a data signal during both real time (i.e., on the fly) and retry operation. The system may include a first equalizer circuit operable to equalize a first sample set, and a second equalizer circuit operable to equalize a second sample set. The system may include a third equalizer circuit operable to equalize a summed data set to yield a third equalized output. The system may include a summation circuit connected to the first equalizer circuit, the second equalizer circuit, and a switch circuit. The summation circuit is operable to sum at least the first equalized data set and the second equalized data set to yield the summed data set. The switch circuit selectively provides the third equalized data set to the summation circuit.
    Type: Grant
    Filed: December 14, 2015
    Date of Patent: February 14, 2017
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventors: George Mathew, Jongseung Park, Han Fang, Richard Rauschmayer
  • Patent number: 9548079
    Abstract: According to one embodiment, a magnetic recording and reproducing device includes a magnetic recording medium, a recording unit and a reproducing unit. The magnetic recording medium includes a first track and a second track, the first track extending in a first direction, the second track extending in the first direction and being arranged with the first track in a second direction intersecting the first direction. The first track includes first and second sub-tracks extending in the first direction. The second track includes third and fourth sub-tracks extending in the first direction. The second sub-track is disposed between the first and fourth sub-tracks. The third sub-track is disposed between the second and fourth sub-tracks. The recording unit records information in the first and second tracks. The reproducing unit reproduces first information recorded in the first track. The reproducing unit reproduces second information recorded in the second track.
    Type: Grant
    Filed: October 26, 2015
    Date of Patent: January 17, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuya Sugawara, Tomoyuki Maeda, Kenichiro Yamada
  • Patent number: 9472237
    Abstract: Embodiments of the present inventions are related to systems and methods for data processing, and more particularly to systems and methods for reducing inter-track interference in relation to processing data retrieved from a storage medium.
    Type: Grant
    Filed: April 27, 2015
    Date of Patent: October 18, 2016
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventors: Yuqing Yang, Shaohua Yang
  • Patent number: 9431052
    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.
    Type: Grant
    Filed: June 24, 2015
    Date of Patent: August 30, 2016
    Assignee: Marvell World Trade Ltd.
    Inventors: Mats Oberg, Nitin Nangare
  • Patent number: 9424876
    Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for detecting patterns in a data stream. As an example, a data processing system is discussed that includes a sync mark detection circuit and a sync quality output circuit. The sync mark detection circuit is operable to identify a predefined pattern in a received data set, where identification of the predefined pattern results is asserting a sync found output, and where a preamble pattern precedes the predefined pattern in the received data set. The sync quality output circuit is operable to provide a sync mark quality metric indicating a similarity between the preamble pattern and the received data set within a region preceding the predefined pattern.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: August 23, 2016
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventor: Shaohua Yang
  • Patent number: 9354332
    Abstract: A detector (22) detects an event. First and second time-to-digital converters (TDCs) (70, 72) generate first and second time stamps (TS1, TS2) for the detection of the event. The first TDC and the second TDC are both synchronized with a common clock signal (62) that defines a fixed time offset between the second TDC and the first TDC. An autocalibration circuit (120) adjusts the first TDC and the second TDC to keep the time difference between the second time stamp and the first time stamp equal to the fixed time offset between the second TDC and the first TDC. The detector may be a detector array, and trigger circuitry (28) propogates a trigger signal from a trigger detector of the array of detectors to the first and second TDC's. Skew correction circuitry (132, 134, 136, 142, 60, 162) adjusts a timestamp (TS) based on which detector is the triggering detector.
    Type: Grant
    Filed: March 29, 2012
    Date of Patent: May 31, 2016
    Assignee: KONINKLIJKE PHILIPS N.V.
    Inventors: Bernardus Antonius Maria Zwaans, Thomas Frach
  • Patent number: 9288084
    Abstract: A data processing system includes an equalizer circuit operable to equalize digital data according to tap coefficients to yield equalized data, a tap coefficient adaptation circuit operable to adapt the tap coefficients based at least in part on a scaled error signal, a data detector operable to apply a data detection algorithm to the digital data to generate hard decisions and soft decisions, an error calculation circuit operable to calculate an error signal based on the equalized data and on the hard decisions, and a scaling circuit operable to scale the error signal based on the soft decisions to yield the scaled error signal.
    Type: Grant
    Filed: April 23, 2014
    Date of Patent: March 15, 2016
    Assignee: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
    Inventors: Lu Lu, Haitao Xia, Haotian Zhang, Jianzhong Huang
  • Patent number: 9257144
    Abstract: A system for writing data to overlapping physical tracks of a shingled magnetic record (SMR) hard disk drive (HDD) and a method for creating a logical disk from overlapping physical tracks of the SMR HDD. The system comprises a write header and a memory identifying the overlapping physical tracks which are accessible through the logical disk. The physical tracks are spaced from each other by at least the width of the write header. The method comprises mapping in a memory the logical disk to writeable tracks of the overlapping physical tracks, the writeable tracks spaced from each other by at least the width of the write header.
    Type: Grant
    Filed: April 16, 2015
    Date of Patent: February 9, 2016
    Assignee: PMC-Sierra US, Inc.
    Inventor: Dong Zhang
  • Patent number: 9251856
    Abstract: A reader failover system and method are described for a data storage system. At least two reader systems, including a first reader element and a second reader element, situated on the same head, are employed to read a magnetic storage medium. In an aspect, the head is a two-dimensional magnetic recording (TDMR) head. Control circuitry detects when the first reader system provides less than a predetermined performance or fails, and thereafter causes the second reader system, but not the first reader system, to read the magnetic storage medium. In an aspect, a buffer stores a first reader element signal until the control circuitry detects whether or not the first reader element provides less than a predetermined performance or fails. In an aspect, when a reader element fails, data recovery is performed, and all of, or a majority of, the media continues to be readable, improving the data storage system robustness.
    Type: Grant
    Filed: March 20, 2015
    Date of Patent: February 2, 2016
    Assignee: Western Digial Technologies, Inc.
    Inventors: David W. Wheelock, Shafa Dahandeh, Anantha Raman Krishnan, Aravind Raghunathan, Kent D. Anderson
  • Patent number: 9230567
    Abstract: According to one embodiment, a microwave-assisted magnetic recording head includes a SIL formed either in an area outside a FGL in a track width direction or in an area outside a FGL in a depth direction perpendicular to an air bearing surface of the FGL. An area between the SIL and the FGL can be enlarged, and an intermediate layer can be formed therebetween such that an area in which the intermediate layer contacts the FGL can be enlarged as well.
    Type: Grant
    Filed: July 29, 2015
    Date of Patent: January 5, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Norihito Fujita, Katsuhiko Koui, Satoshi Shirotori, Mariko Shimizu, Shuichi Murakami
  • Patent number: 9147431
    Abstract: Method and apparatus for decoding data, such as from a rotatable magnetic recording medium. In accordance with some embodiments, a plurality of sensors is provided, with each sensor configured to generate a sense signal from an adjacent pattern. A processing circuit is configured to decode data from the adjacent pattern using the generated sense signals.
    Type: Grant
    Filed: August 6, 2013
    Date of Patent: September 29, 2015
    Assignee: Seagate Technology LLC
    Inventors: Todd Michael Lammers, Robert Matousek, William Michael Radich
  • Patent number: 9147429
    Abstract: Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for processing skew tolerant processing of data derived from multiple read heads.
    Type: Grant
    Filed: March 31, 2014
    Date of Patent: September 29, 2015
    Assignee: Avago Technologies General IP (Singapore) PTE. LTD.
    Inventor: Eui Seok Hwang
  • Patent number: 9105302
    Abstract: Technologies are described herein for utilizing multiple, wide readers to read narrow data tracks on a magnetic recording media in a storage device. A system for reading a data track on a magnetic recording media comprises a plurality of reader elements and a multi-reader decoder module operably connected to the plurality of reader elements. Each of the reader elements is configured to read a magnetic signal from the magnetic recording media. Each reader element may be wider than a width of the data track on the recording media. The multi-reader decoder module is configured to receive a read signal from each of the reader elements, and decode the data on the data track based on the read signals from the reader elements.
    Type: Grant
    Filed: July 29, 2014
    Date of Patent: August 11, 2015
    Assignee: Seagate Technology LLC
    Inventors: Mehmet Fatih Erden, Jason Charles Jury
  • Patent number: 9082418
    Abstract: According to various embodiments, a method for reading data from a storage medium using a reader may be provided. The method may include: reading a first signal with a reader head of the reader at a first position of the storage medium; reading a second signal with a reader head of the reader at a second position of the storage medium; and determining data stored at a pre-determined position of the storage medium based on the first signal and based on the second signal.
    Type: Grant
    Filed: July 16, 2013
    Date of Patent: July 14, 2015
    Assignee: MARVELL INTERNATIONAL LTD.
    Inventors: Chun Lian Ong, Zhimin Yuan, Siang Huei Leong, Bo Liu