Patents by Inventor David Liaw

David Liaw 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: 9070396
    Abstract: Embodiments of the present disclosure provide a method of self-servo writing, the method comprising actions of positionally tracking a selected timing track of a data storage disk, wherein the selected timing track has one or more timing segments; synchronizing an angular position signal to rotation of the data storage disk based on at least one of the one or more timing segments of the selected timing track; specifying servo sector positions relative to the synchronized angular position signal; writing servo sectors to the data storage disk at the specified servo sector positions relative to the synchronized angular position signal; detecting one or more positional errors in timing segments of a next timing track of the data storage disk based at least in part on the synchronized angular position signal; and accounting for the detected one or more positional errors in writing subsequent servo tracks. Other embodiments are also described.
    Type: Grant
    Filed: November 3, 2014
    Date of Patent: June 30, 2015
    Assignee: Marvell International Ltd.
    Inventors: Supaket Katchmart, David Liaw, Jerome F. Richgels, Henri Sutioso
  • Patent number: 8879190
    Abstract: Embodiments of the present disclosure provide a method of self-servo writing, the method comprising actions of positionally tracking a selected timing track of a data storage disk, wherein the selected timing track has one or more timing segments; synchronizing an angular position signal to rotation of the data storage disk based on at least one of the one or more timing segments of the selected timing track; specifying servo sector positions relative to the synchronized angular position signal; writing servo sectors to the data storage disk at the specified servo sector positions relative to the synchronized angular position signal; detecting one or more positional errors in timing segments of a next timing track of the data storage disk based at least in part on the synchronized angular position signal; and accounting for the detected one or more positional errors in writing subsequent servo tracks. Other embodiments are also described.
    Type: Grant
    Filed: July 20, 2012
    Date of Patent: November 4, 2014
    Assignee: Marvell International Ltd.
    Inventors: Supaket Katchmart, David Liaw, Jerome F. Richgels, Henri Sutioso
  • Patent number: 8854761
    Abstract: A method of writing servo data to a data storage medium includes reading a servo instruction from a memory, the servo instruction comprising a control portion and a data portion, processing the servo instruction in a controller to generate a servo data pattern from the data portion based on the control portion, and transferring the servo data pattern to the data storage medium. The processing may include transforming the data portion into the servo data pattern based on the control portion. The processing also may include following a command in the control portion to use the data portion as an index to retrieve a pre-programmed servo data pattern from a pattern store. The transferring may include storing the servo data pattern in a buffer, and writing the servo data pattern from the buffer to the data storage medium.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: October 7, 2014
    Assignee: Marvell International Ltd.
    Inventors: Supaket Katchmart, David Liaw
  • Patent number: 8593755
    Abstract: Some of the embodiments of the present disclosure provide a disk drive system comprising a disk drive system comprising a disk having a track upon a surface of the disk, the track including a first data-storing sector and a second data storing sector, and a servo sector located between the first data-storing sector and the second data-storing sector, the servo sector including a first flying height (FH) field having a predetermined pattern. Other embodiments are also described and claimed.
    Type: Grant
    Filed: November 14, 2012
    Date of Patent: November 26, 2013
    Assignee: Marvell International Ltd.
    Inventors: Pantas Sutardja, Supaket Katchmart, Henri Sutioso, David Liaw
  • Patent number: 8315007
    Abstract: Some of the embodiments of the present disclosure provide a disk drive system comprising a disk drive system comprising a disk having a track upon a surface of the disk, the track including a first data-storing sector and a second data storing sector, and a servo sector located between the first data-storing sector and the second data-storing sector, the servo sector including a first flying height (FH) field having a predetermined pattern. Other embodiments are also described and claimed.
    Type: Grant
    Filed: January 13, 2012
    Date of Patent: November 20, 2012
    Assignee: Marvell International Ltd.
    Inventors: Pantas Sutardja, Supaket Katchmart, Henri Sutioso, David Liaw
  • Patent number: 8169735
    Abstract: A system including a read module, a clock generator module, and a write module. The read module generates read signals in response to reading servo spirals from a magnetic medium of a hard disk drive. The clock generator module generates a spiral clock based on the read signals, and generates, based on the spiral clock, (i) a first write clock and (ii) a second write clock. The spiral clock has a first frequency, the first write clock has a second frequency, and the second write clock has a third frequency. The write module is configured to (i) write a first servo wedge on a first zone of the magnetic medium of the hard disk drive based on the first write clock, and (ii) write a second servo wedge on a second zone of the magnetic medium of the hard disk drive based on the second write clock.
    Type: Grant
    Filed: September 26, 2011
    Date of Patent: May 1, 2012
    Assignee: Marvell International Ltd.
    Inventors: Pantas Sutardja, Sukpaket Katchmart, Henri Sutioso, David Liaw
  • Patent number: 8098452
    Abstract: Some of the embodiments of the present disclosure provide a disk drive system comprising a disk drive system comprising a disk having a track upon a surface of the disk, the track including a first data-storing sector and a second data storing sector, and a servo sector located between the first data-storing sector and the second data-storing sector, the servo sector including a first flying height (FH) field having a predetermined pattern. Other embodiments are also described and claimed.
    Type: Grant
    Filed: January 14, 2011
    Date of Patent: January 17, 2012
    Assignee: Marvell International Ltd.
    Inventors: Pantas Sutardja, Supaket Katchmart, Henri Sutioso, David Liaw
  • Patent number: 8027117
    Abstract: A hard disk controller (HDC) of a hard disk drive (HDD) includes a read module, a clock generator module, and a write module. The read module reads servo spirals from a magnetic medium of the HDD via a read head of the HDD and generates read signals. The clock generator module generates a spiral clock having a first frequency based on the read signals and generates based on the spiral clock R write clocks having R frequencies, respectively, that are different than the first frequency, where R is an integer greater than 1. The write module writes via a write head of the HDD a first servo wedge on a first one of R zones of the magnetic medium using a first one of the R write clocks and a second servo wedge on a second one of the R zones using a second one of the R write clocks.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: September 27, 2011
    Assignee: Marvell International Ltd.
    Inventors: Pantas Sutardja, Sukpaket Katchmart, Henri Sutioso, David Liaw
  • Patent number: 7872828
    Abstract: Some of the embodiments of the present disclosure provide a disk drive system comprising a disk drive system comprising a disk having a track upon a surface of the disk, the track including a first data-storing sector and a second data storing sector, and a servo sector located between the first data-storing sector and the second data-storing sector, the servo sector including a first flying height (FH) field having a predetermined pattern. Other embodiments are also described and claimed.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: January 18, 2011
    Assignee: Marvell International Ltd.
    Inventors: Pantas Sutardja, Supaket Katchmart, Henri Sutioso, David Liaw