Patents by Inventor William F. Butterfield

William F. Butterfield 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: 5689371
    Abstract: An optical filter assembly for use on a visual display device is disclosed. Included in the assembly is a frame defining a viewing aperture which frame is mounted on a visual display device such that the aperture is in registry with the screen of the visual display device. An optical filter is provided for covering the aperture. The frame assembly includes a plurality of side walls which extend the distance sufficient for reducing the passage of room light to behind the optical filter. The frame assembly also includes structure for holding releasably the optical filter to the frame assembly and structure associated with the frame assembly for spacing the optical filter from the display screen. Included is spacing structure which includes a protrusion intrical with the frame for contacting the display screen for thereby physically spacing the filter from the display screen.
    Type: Grant
    Filed: August 30, 1995
    Date of Patent: November 18, 1997
    Assignee: Polaroid Corporation
    Inventor: William F. Butterfield
  • Patent number: 4747674
    Abstract: A contrast enhancement filter having antistatic and antireflection properties is disclosed. The article comprises a plastic support sheet carrying on one side thereof a layer of indium tin oxide, and superposed upon said layer, an antireflection layer. A light-polarizing element is affixed to the opposed side thereof. The contrast enhancement filter can be used for the reduction of specular glare from the surface of cathode ray tubes, computer display screens and the like.
    Type: Grant
    Filed: March 30, 1987
    Date of Patent: May 31, 1988
    Assignee: Polaroid Corporation
    Inventors: William F. Butterfield, Kuang-Chou Chang, Edmund J. McLelland, Leonard Polizzotto