Patents by Inventor Donald E. Sprothbery

Donald E. Sprothbery 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 layout for a three light valve full-color projector employing a dual relay lens system and a single projection lens
    Patent number: 4836649
    Abstract: A liquid crystal light valve projector is disclosed which includes source illumination appratus which images an illumination aperture at the liquid crystal light valves, and further includes light valve imaging apparatus for relaying the light valve images to a wide angle projection lens having a short back focal length. The disclosed liquid crystal light valve projector utilizes air separated dichroic color separator for providing primary color illumination to the light valves.
    Type: Grant
    Filed: July 19, 1985
    Date of Patent: June 6, 1989
    Assignee: Hughes Aircraft Company
    Inventors: Arno G. Ledebuhr, Donald E. Sprothbery