Patents by Inventor Jeff Stephenson

Jeff Stephenson 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: 4691152
    Abstract: A velocity estimator for a voice coil motor driven actuator is implemented by integrating coil current to generate the estimated velocity and integrating the estimated velocity signal to produce an estimated position signal. The estimated position signal and a measured position signal are compared and the derived error signal is applied as negative feedback to the summing junctions at the inputs of each of the integrators. The use of an integrated signal results in reduced noise influence on the position error signal which, in the environment of a data disk drive, results in more reliable recording of track crossings and the ability to meet rigid product specifications using simple servo patterns.
    Type: Grant
    Filed: February 19, 1986
    Date of Patent: September 1, 1987
    Assignee: International Business Machines Corporation
    Inventors: Travis E. Ell, Jeff Stephenson