Patents by Inventor Siew Kin Chow

Siew Kin Chow 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: 9978403
    Abstract: Data is written to a recording medium via a read/write head. Subsequent to the writing, the data is read via a read transducer of a read/write head. An instability indicator is derived based on measurements performed while the reading the data. If the instability indicator exceeds a threshold, a current applied to a write coil of the read/write head is changed for subsequent write operations.
    Type: Grant
    Filed: February 17, 2017
    Date of Patent: May 22, 2018
    Assignee: Seagate Technology LLC
    Inventors: Wenzhong Zhu, Alfredo Sam Chu, Siew Kin Chow
  • Patent number: 9892752
    Abstract: An operational laser power for a heat-assisted, magnetic recording head is selected based on a function of a write quality metric versus laser power. The write quality metric of data written to a magnetic recording medium is monitored at the operational laser power. Responsive to the write quality metric satisfying a threshold, a power difference between the operational laser power and an offset laser power is determined. The offset laser power corresponds to a point of the function where the write quality metric is approximately equal to the threshold. A maximum laser power is set for a calibration operation. The maximum laser power is based on the sum of the operational laser power and the power difference.
    Type: Grant
    Filed: June 15, 2017
    Date of Patent: February 13, 2018
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Alfredo Sam Chu, Siew Kin Chow, Franklin P. Martens
  • Patent number: 9734862
    Abstract: A first tone is written at a first frequency to outer tracks that surround an inner track of a magnetic recording medium. A second tone is written at a second frequency different from the first frequency to the inner track. The first and second frequencies are both lower than a frequency of an AC erase signal. A crosstrack profile of the inner track is determined based on reading amplitude of the second frequency via the read/write head.
    Type: Grant
    Filed: October 17, 2016
    Date of Patent: August 15, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Alfredo Sam Chu, Wenzhong Zhu, Siew Kin Chow, Franklin P. Martens
  • Patent number: 9396750
    Abstract: A system may have a data storage medium that contains at least one data bit that is accessed by a transducing head that has a near-field transducer. A controller can be connected to the transducing head and store a plurality of near-field transducer operating currents in a memory. The controller may identify a change in efficiency of the near-field transducer from the plurality of near-field transducer operating currents.
    Type: Grant
    Filed: September 14, 2015
    Date of Patent: July 19, 2016
    Assignee: Seagate Technology LLC
    Inventors: Alfredo Chu, Kenneth Arthur Haapala, Paul William Burnett, Siew Kin Chow
  • Publication number: 20150380040
    Abstract: A system may have a data storage medium that contains at least one data bit that is accessed by a transducing head that has a near-field transducer. A controller can be connected to the transducing head and store a plurality of near-field transducer operating currents in a memory. The controller may identify a change in efficiency of the near-field transducer from the plurality of near-field transducer operating currents.
    Type: Application
    Filed: September 14, 2015
    Publication date: December 31, 2015
    Inventors: Alfredo Chu, Kenneth Arthur Haapala, Paul William Burnett, Siew Kin Chow
  • Patent number: 9142244
    Abstract: A system may have a data storage medium that contains at least one data bit that is accessed by a transducing head that has a near-field transducer. A controller can be connected to the transducing head and store a plurality of near-field transducer operating currents in a memory. The controller may identify a change in efficiency of the near-field transducer from the plurality of near-field transducer operating currents.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: September 22, 2015
    Assignee: Seagate Technology LLC
    Inventors: Alfredo Sam Chu, Kenneth Arthur Haapala, Paul William Burnett, Siew Kin Chow
  • Publication number: 20150235665
    Abstract: A system may have a data storage medium that contains at least one data bit that is accessed by a transducing head that has a near-field transducer. A controller can be connected to the transducing head and store a plurality of near-field transducer operating currents in a memory. The controller may identify a change in efficiency of the near-field transducer from the plurality of near-field transducer operating currents.
    Type: Application
    Filed: February 20, 2014
    Publication date: August 20, 2015
    Applicant: Seagate Technology LLC
    Inventors: Alfredo Sam Chu, Kenneth Arthur Haapala, Paul William Burnett, Siew Kin Chow
  • Patent number: 9093091
    Abstract: A pattern is written to only a portion of a test track of a magnetic disk. The pattern written to the portion of the test track is read using a read head. A cross-track offset between the read head and a write head is determined at a position on a disk based on reading the pattern.
    Type: Grant
    Filed: September 22, 2014
    Date of Patent: July 28, 2015
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Alfredo Sam Chu, Siew Kin Chow
  • Patent number: 8004786
    Abstract: A data storage device, e.g., a disc drive, includes one or more heads including a transducer. Each head also includes a deformable material that allows the spacing adjustments between the transducer and a data storage medium, e.g., a data storage disc, according to each of a plurality of settings. The device calculates a response function of a spacing change to a setting change for each head by measuring a change in the pole tip-data storage medium spacing corresponding to at least two settings. The device also determines an optimal setting. The device may also repeat response function calculations and/or determination of optimal settings to ensure continued optimal performance of the device. In summary, the device sets an optimal setting for each head according to a calculated response function particular to each head.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: August 23, 2011
    Assignee: Seagate Technology LLC
    Inventors: Jason M. Feist, Dallas S. Holm, Jr., Siew Kin Chow, Scott E. Ryun
  • Publication number: 20070195449
    Abstract: A data storage device, e.g., a disc drive, includes one or more heads including a transducer. Each head also includes a deformable material that allows the spacing adjustments between the transducer and a data storage medium, e.g., a data storage disc, according to each of a plurality of settings. The device calculates a response function of a spacing change to a setting change for each head by measuring a change in the pole tip-data storage medium spacing corresponding to at least two settings. The device also determines an optimal setting. The device may also repeat response function calculations and/or determination of optimal settings to ensure continued optimal performance of the device. In summary, the device sets an optimal setting for each head according to a calculated response function particular to each head.
    Type: Application
    Filed: February 17, 2006
    Publication date: August 23, 2007
    Applicant: Seagate Technology LLC
    Inventors: Jason Feist, Dallas Holm, Siew Kin Chow, Scott Ryun
  • Patent number: 6831796
    Abstract: The present invention is directed to detecting amplitude modulation on the written signal as a result of head movement along the z-axis during the write operation, before the head has had sufficient time to stabilize after seeking from a different track.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: December 14, 2004
    Assignee: Seagate Technology LLC
    Inventors: YeongHeng Tan, Siew Kin Chow
  • Publication number: 20020027730
    Abstract: The present invention is directed to detecting amplitude modulation on the written signal as a result of head movement along the z-axis during the write operation, before the head has had sufficient time to stabilize after seeking from a different track.
    Type: Application
    Filed: June 27, 2001
    Publication date: March 7, 2002
    Inventors: YeongHeng Tan, Siew Kin Chow