Patents Examined by Richard A. Rusenberger
  • Patent number: 4007979
    Abstract: A device which eliminates unwanted light rays and permits passage of desired light rays. For the purposes of this specification, the desired light rays are those which originate on a first side of a material capable of effecting light passage, and which pass through the material to a second side. Undesirable light rays are those originating on the second side of the material, which pass through the material to the second side of the material. The material, in the embodiment illustrated, is a beam splitter intended to present a desired scene to an observer. The preferred embodiment includes a linear polarizer and a quarter wave retarder which impart an elliptical polarization to the undesired light rays.
    Type: Grant
    Filed: April 18, 1975
    Date of Patent: February 15, 1977
    Assignee: McDonnell Douglas Corporation
    Inventor: David B. Coblitz