Patents by Inventor David A. Spaulding

David A. Spaulding 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).

  • Method and disk drive for improving head position accuracy during track following through real-time identification of external vibration and monitoring of write-unsafe occurrences
    Patent number: 6900958
    Abstract: A method is disclosed for improving head position accuracy in a disk drive during track following of concentric data storage tracks through real-time identification of external vibration and monitoring of write-unsafe (WUS) occurrences. In the method, after a seek operation to a predetermined data storage track, the track is followed using a servo control loop having a nominal gain and responsive to a position error signal (PES). After waiting a vibration detection delay period, occurrences of the PES exceeding a WUS limit are counted generating a WUS limit exception count. Also, a property of a variance is determined from spectral power values generated from the PES during track following. If the WUS limit exception count exceeds a first threshold, and if the property of the variance exceeds a second threshold, the nominal gain is increased to a vibration gain within a frequency band, to attenuate the effect of external vibration.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: May 31, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Li Yi, Yanbin Song, David A. Spaulding, Arafat M. Butt, Robert J. McNab, David D. Nguyen