Patents by Inventor Douglas W. Nelson

Douglas W. Nelson 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: 5289097
    Abstract: A spindle motor control method and apparatus for spindle motor control are provided for use in a direct access storage device. A plurality of operational modes of the direct access storage device are detected. The operational modes of the direct access storage device include start-up and idle operational modes and predetermined critical operational modes that include reading of data and reading of servo information. A pulse width modulation (PWM) mode control for applying driving current to the spindle motor is provided responsive to detecting a start-up or an idle operational mode. A linear mode control for applying driving current to the spindle motor is provided responsive to detecting one of the predetermined critical operational modes. During operation of the disk file, a small percentage of the overall file power-on time is spent performing critical file operations so that substantial power savings are achieved by the PWM mode control.
    Type: Grant
    Filed: August 18, 1992
    Date of Patent: February 22, 1994
    Assignee: International Business Machines Corporation
    Inventors: Kevin J. Erickson, Richard Greenberg, Douglas W. Nelson