Patents by Inventor Mark A. Nokes

Mark A. Nokes 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: 5212580
    Abstract: A raster scan apparatus provides a scanning assembly capable of moving in a sinusoidal motion along a first direction and stepping in fine steps in a second direction perpendicular to the first direction. In one embodiment, a piezoelectric bimorph sets in scanning motion a scanning assembly formed by a wafer holder and leaf springs. The amplitude of the scanning motion is controlled by a voltage applied across the piezoelectric bimorph. A Hall effect sensor provides an output signal indicating the instantaneous location of the scanning assembly in motion. The output signal of the Hall effect sensor is compared against a predetermined threshold to provide a trigger signal for synchronization. The output signal of the Hall effect sensor is also fed back to the source of sinusoidal voltage to adaptively adjust the sinusoidal voltage so as to achieve a predetermined amplitude for the scanning motion.
    Type: Grant
    Filed: February 12, 1992
    Date of Patent: May 18, 1993
    Assignee: High Yield Technology
    Inventors: George L. Coad, James B. Stolz, Yung C. Lee, Ron B. Whitney, Peter G. Borden, Mark A. Nokes