Patents by Inventor Frederick K. Groll

Frederick K. Groll 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: 4890172
    Abstract: A method for automatically calibrating gain parameters of a servo control including a track position detector for a computer disk drive. The method generally comprises the step of encoding AB bursts on at least one special calibration track of a disk surface in accordance with a known off center pattern signal having a preselected frequency. Servo correction number information is also encoded on the calibration track to compensate for the off center pattern of the AB bursts. A digital signal processing technique is performed on a correction signal derived from the AB bursts and servo correction number information to detect a residual signal at the preselected frequency of the off center pattern signal. The gain of the track position detector is thereafter adjusted to minimize the magnitude of the residual signal.
    Type: Grant
    Filed: September 27, 1988
    Date of Patent: December 26, 1989
    Assignee: Digital Equipment Corporation
    Inventors: Charles R. Watt, Frederick K. Groll, John A. Scaramuzzo, Jr.