Patents by Inventor Alex M. Purcell

Alex M. Purcell 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).

  • Optical tablet construction
    Patent number: 4936683
    Abstract: An optical digitizer or tablet employing a linear image sensor behind a microlouver strip and extending along a coordinate axis of a coordinate axes plane. In one embodiment, a non-directional light source floods the plane, and a cursor is provided with a reflector that reflects incident light. In another embodiment, the light source is on the reflector, and the sensor-microlouver combination is located along each tablet edge.
    Type: Grant
    Filed: June 22, 1989
    Date of Patent: June 26, 1990
    Assignee: Summagraphics Corporation
    Inventor: Alex M. Purcell