Patents by Inventor Chun Sei Tsai

Chun Sei Tsai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8694841
    Abstract: A method to enable defect margining of a disk drive may comprise executing a data access command on a target sector on the disk drive. Upon encountering a data access error at the target sector, an address of the target sector may be added to an error list. The address of the target sector in the error list may then be converted to a physical location on the disk drive. A thermal asperity scan may be performed at and around the physical location and, upon detecting a thermal asperity, and at least sectors around the detected thermal asperity may be margined, and the data stored within the margined sectors may be relocated. Instead of sectors, entire tracks may be margined and the data stored therein relocated to a spare or reserve location, one track at a time.
    Type: Grant
    Filed: June 20, 2012
    Date of Patent: April 8, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Heon Ho Chung, Chun Sei Tsai, Carl E. Barlow, Kenneth J. Smith
  • Patent number: 8612798
    Abstract: A hybrid drive is disclosed comprising a head actuated over a disk comprising a plurality of data sectors, a volatile semiconductor memory (VSM), and a non-volatile semiconductor memory (NVSM). A first write command is received from a host, the first write command comprising first data. The first data is stored in the VSM and written to a first data sector on the disk. The first data is read from the first data sector at least once during a first read operation, and when the first read operation fails, the first data is written to the NVSM. The first data sector is read at least once during a second read operation, and when the second read operation fails, the first data sector is mapped out.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: December 17, 2013
    Assignee: Western Digital Technologies, Inc.
    Inventor: Chun Sei Tsai
  • Patent number: 8427771
    Abstract: A hybrid drive is disclosed comprising a head actuated over a disk comprising a plurality of data sectors, and a non-volatile semiconductor memory (NVSM) comprising a plurality of memory segments. A read command is received from a host to read data from a first data sector. Data is read from the first data sector during a first read operation and a determination is made as to whether the first data sector is suspect. When the first data sector is suspect, the data is written to a first memory segment of the NVSM.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: April 23, 2013
    Assignee: Western Digital Technologies, Inc.
    Inventor: Chun Sei Tsai
  • Patent number: 8429343
    Abstract: A hybrid drive is disclosed comprising a head actuated over a disk comprising a plurality of data sectors, and a non-volatile semiconductor memory (NVSM). A plurality of refresh zones are defined, wherein each refresh zone comprises a plurality of the data sectors on the disk, and a refresh monitor is maintained for each refresh zone. When a write command is received from a host comprising data and the data is targeted to the NVSM, the data is written to the NVSM. When the data is targeted to a first refresh zone on the disk, and a first refresh monitor has not reached a refresh limit, the data is written to the first refresh zone. When the data is targeted to the first refresh zone on the disk, and the first refresh monitor has reached the refresh limit, the data is written to the NVSM.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: April 23, 2013
    Assignee: Western Digital Technologies, Inc.
    Inventor: Chun Sei Tsai
  • Patent number: 8320067
    Abstract: Systems and methods for performing refresh operations using write/read commands are provided. In one embodiment, a disk drive comprises a disk partitioned into a plurality of refresh zones, a head configured to write data to and read data from the disk, and a controller. The controller is configured to receive an access command, to read data from at least one of the refresh zones using the head in response to the access command, to check a condition of the read data, and to determine whether to refresh the at least one refresh zone based on the condition of the read data, wherein the read data includes data from a portion of the at least one refresh zone not being accessed by the access command.
    Type: Grant
    Filed: May 18, 2010
    Date of Patent: November 27, 2012
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chun Sei Tsai, Sang Huynh, Kenneth J. Smith, Carl E. Barlow
  • Patent number: 8271692
    Abstract: A storage device comprising a storage media and a controller is disclosed. The controller is configured to receive access commands from a host, to write data to or read data from the storage media based on the access commands, to detect a trigger event, and, when the trigger event is detected, to throttle back the access commands from the host based on an amount of data in a cache.
    Type: Grant
    Filed: October 1, 2010
    Date of Patent: September 18, 2012
    Assignee: Western Digital Technologies, Inc.
    Inventors: Peter H. Dinh, Carl E. Barlow, Joseph M. Viglione, Sang Huynh, Chun Sei Tsai
  • Patent number: 8174780
    Abstract: A disk drive is disclosed including a disk, and a head actuated over the disk. Control circuitry within the disk drive is operable to receive a write operation for a refresh zone of the disk, measure a write operation quality parameter that affects the quality of the write operation, and perform the write operation. An update function is enabled in connection with performing the write operation, wherein the update function is operable to update a refresh monitor as a function of the write operation and the write operation quality parameter. Data stored in the refresh zone of the disk is refreshed in response to the refresh monitor.
    Type: Grant
    Filed: June 27, 2007
    Date of Patent: May 8, 2012
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chun Sei Tsai, William B. Boyle, Michael S. Rothberg
  • Patent number: 8149528
    Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks. A first defect shape is detected during a manufacturing defect scan of the disk. A second defect shape is detected while the disk drive is deployed in-the-field. Whether the first defect shape is connectable to the second defect shape is determined, and when the first defect shape is connectable to the second defect shape, data sectors along a trajectory between the first defect shape and the second defect shape are relocated.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: April 3, 2012
    Assignee: Western Digital Technologies, Inc.
    Inventors: Dody Suratman, Chirag C. Patel, Chun Sei Tsai
  • Patent number: 8116025
    Abstract: A disk drive is disclosed comprising a disk having a plurality of tracks, wherein each track comprises a plurality of data sectors. A head is actuated radially over the disk for generating a read signal. A first read of a data sector is performed while adjusting an amplitude of the read signal in response to a gain control setting. When an error occurs while attempting to first read the data sector, a first jog value is generated in response to the gain control setting. The head is served over the data sector in response to the first jog value, and a second read of the data sector is performed.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: February 14, 2012
    Assignee: Western Digital Technologies, Inc.
    Inventors: Tom S. Chan, Chun Sei Tsai, Carl E. Barlow, Colin W. Morgan
  • Patent number: 8031423
    Abstract: A disk drive is disclosed comprising a head actuated over a disk having a plurality of data tracks. An ideal data tracks per inch (TPI) profile is determined for the disk, and an actual data TPI profile is generated that estimates the ideal data TPI profile by combining a first segment of a first predetermined data TPI profile and a second segment of a second predetermined data TPI profile.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: October 4, 2011
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chun Sei Tsai, Stephany W. Kwan, Kameron Kam-Wai Jung
  • Patent number: 8004785
    Abstract: A disk drive is disclosed comprising a disk having a plurality of data sectors, wherein a physical block address (PBA) is associated with each data sector. When a write command is received from a host to write user data to the disk, and the write command comprises an unformatted logical block address (LBA), the user data is written to a first data sector, and the first data sector is write verified. A second data sector is defect scanned, and after the second data sector passes the defect scan, the user data is migrated from the first data sector to the second data sector and the LBA is formatted to the second data sector.
    Type: Grant
    Filed: May 9, 2008
    Date of Patent: August 23, 2011
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chun Sei Tsai, William B. Boyle, Carl E. Barlow, Kenneth J. Smith
  • Patent number: 7982993
    Abstract: A disk drive is disclosed having a first disk surface, and a head actuated over the first disk surface. The first disk surface comprises a plurality of servo tracks and a plurality of data tracks. The data tracks of the first disk surface are banded together into a plurality of data zones, including a first data zone and a second data zone. A first servo tracks per inch (STPI) to data tracks per inch (DTPI) ratio of the first data zone is substantially different from a second STPI to DTPI ratio of the second data zone.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: July 19, 2011
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chun Sei Tsai, William B. Boyle, Carl E. Barlow
  • Patent number: 7974029
    Abstract: A disk drive is disclosed comprising a disk comprising a plurality of tracks, and a head actuated over the disk. A plurality of refresh zones are defined, wherein each refresh zone corresponds to a plurality of the tracks. Data is written to a first refresh zone, and a first zone counter is updated for a second refresh zone at a first rate. Data is written to a third refresh zone, and the first zone counter is updated for the second refresh zone at a second rate different than the first rate.
    Type: Grant
    Filed: July 31, 2009
    Date of Patent: July 5, 2011
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chun Sei Tsai, Sang Huynh, Anthony L. Pei, Don Brunnett, Jahangir John Kasraee, Kent W. Gibbons
  • Patent number: 7945727
    Abstract: A disk drive is disclosed including a disk comprising a plurality of refresh zones, and a head actuated over the disk. The disk drive further comprises control circuitry for receiving access commands from a host. The control circuitry refreshes a refresh zone in a plurality of segments with an interval between each segment, and processes at least one of the access commands during the interval between at least two of the segments, wherein a size of each segment and the interval ensures an average throughput of access commands received from the host does not fall below a first threshold.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: May 17, 2011
    Assignee: Western Digital Technologies, Inc.
    Inventors: Michael S. Rothberg, William B. Boyle, Chun Sei Tsai
  • Patent number: 7933087
    Abstract: A disk drive is disclosed comprising a disk having a plurality of data sectors, and a head actuated over the disk. The disk drive further comprises control circuitry operable to execute a write operation for writing data to the disk. A first part of the data is written to a first data sector together with a first sector signature data (SSD) record comprising a first parameter of the write operation and a first id that identifies the first parameter. A second part of the data is written to a second data sector together with a second SSD record comprising a second parameter of the write operation and a second id that identifies the second parameter.
    Type: Grant
    Filed: June 18, 2008
    Date of Patent: April 26, 2011
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chun Sei Tsai, William B. Boyle, Carl E. Barlow
  • Patent number: 7929234
    Abstract: A disk drive is disclosed comprising a head actuated over a disk, the disk having a plurality of data tracks, wherein a first plurality of data tracks comprises a first plurality of defect scanned data sectors and a second plurality of data tracks comprises a second plurality of unscanned data sectors. The second plurality of data tracks is divided into a plurality of defect zones. A first number of write commands are received from a host to write data to a first defect zone. A first data sector in the first defect zone is defect scanned in response to the first number of write commands to the first defect zone.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: April 19, 2011
    Assignee: Western Digital Technologies, Inc.
    Inventors: William B. Boyle, Chun Sei Tsai, Anthony L. Pei
  • Publication number: 20110026159
    Abstract: A disk drive is disclosed comprising a disk comprising a plurality of tracks, and a head actuated over the disk. A plurality of refresh zones are defined, wherein each refresh zone corresponds to a plurality of the tracks. Data is written to a first refresh zone, and a first zone counter is updated for a second refresh zone at a first rate. Data is written to a third refresh zone, and the first zone counter is updated for the second refresh zone at a second rate different than the first rate.
    Type: Application
    Filed: July 31, 2009
    Publication date: February 3, 2011
    Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: CHUN SEI TSAI, SANG HUYNH, ANTHONY L. PEI, DON BRUNNETT, JAHANGIR JOHN KASRAEE, KENT W. GIBBONS
  • Patent number: 7852596
    Abstract: A disk drive is disclosed comprising a disk and a head actuated over the disk. The disk comprises a plurality of tracks, wherein each track comprises a plurality of data sectors. A read command is received from a host to read data from a target data sector. When it is determined that the target data sector has not been written by the host, dummy data is returned to the host.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: December 14, 2010
    Assignee: Western Digital Technologies, Inc.
    Inventors: William B. Boyle, Chun Sei Tsai
  • Publication number: 20100214682
    Abstract: A disk drive is disclosed comprising a disk and a head actuated over the disk. The disk comprises a plurality of tracks, wherein each track comprises a plurality of data sectors. A read command is received from a host to read data from a target data sector. When it is determined that the target data sector has not been written by the host, dummy data is returned to the host.
    Type: Application
    Filed: February 25, 2009
    Publication date: August 26, 2010
    Applicant: Western Digital Technologies, Inc.
    Inventors: WILLIAM B. BOYLE, CHUN SEI TSAI
  • Publication number: 20090027799
    Abstract: A disk drive is disclosed including a disk comprising a plurality of refresh zones, and a head actuated over the disk. The disk drive further comprises control circuitry for receiving access commands from a host. The control circuitry refreshes a refresh zone in a plurality of segments with an interval between each segment, and processes at least one of the access commands during the interval between at least two of the segments, wherein a size of each segment and the interval ensures an average throughput of access commands received from the host does not fall below a first threshold.
    Type: Application
    Filed: July 27, 2007
    Publication date: January 29, 2009
    Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: MICHAEL S. ROTHBERG, WILLIAM B. BOYLE, CHUN SEI TSAI