Patents by Inventor Chirag C. Patel

Chirag C. Patel 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).

  • Disk drive calibrating defect threshold based on statistical quality metric measured for reference tracks
    Patent number: 9202517
    Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks. First data is written to a first data track, and the first data is read from the first data track to measure a first quality metric representing a recording quality of the first data. Second data is written to a second data track, and the second data is read from the second data track to measure a second quality metric representing a recording quality of the second data. The first and second quality metrics are processed to generate a first statistical quality metric. A first defect threshold is generated based on the first statistical quality metric, and at least part of the disk is scanned for defects based on the first defect threshold.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: December 1, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Carl E. Barlow, Chirag C. Patel, Andrew W. Fok, Chun Sei Tsai, Donald Brunnett
  • Data storage device screening heads by verifying defects after defect scan
    Patent number: 9117489
    Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of tracks. A defect scan of at least one of the tracks is executed, and a log entry is generated when a defect is detected. After the defect scan, a verify operation is executed for at least two of the detected defects. A number of times the verify operation detects a false defect is counted, and whether the head is defective is determined based at least partly on the count.
    Type: Grant
    Filed: February 18, 2014
    Date of Patent: August 25, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Dean V. Dang, Chun Sei Tsai, Chirag C. Patel, Ammar A. Zayed, Carl E. Barlow, Thao Hieu Banh
  • Disk drive detecting different asperities on a disk using different sensor bias settings
    Patent number: 8902533
    Abstract: A disk drive is disclosed comprising a disk comprising a plurality of data tracks, and a head actuated over the disk, the head comprising an asperity sensor operable to generate a sensor signal having a magnitude based on a bias setting of the asperity sensor. The asperity sensor is configured with a first bias setting and a first asperity on the disk is detected based on the sensor signal generated at the first bias setting. The asperity sensor is configured with a second bias setting different from the first bias setting and a second asperity on the disk is detected based on the sensor signal generated at the second bias setting.
    Type: Grant
    Filed: August 30, 2013
    Date of Patent: December 2, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Carl E. Barlow, Chun Sei Tsai, Chirag C. Patel, Boon Sien Chew, Thomas A. O'Dell, David E. Wachenschwanz, David E. Fowler
  • Disk drive connecting defect shapes to preempt data loss
    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