Patents by Inventor Wilhelm Krahn

Wilhelm Krahn 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).

  • Apparatus for the perimetric testing of the visual field of the human eye
    Patent number: 4045130
    Abstract: A perimetric testing apparatus is described for use in testing the field of vision of human eyes. This apparatus includes an approximately hemispherical shell together with a device for projecting successive light pattern groups onto the inner surface of the shell. The device includes shadow masks, representative of different light pattern groups, which may be selectively inserted into the light path of a light source projector. The apparatus may be used in a dynamic perimeter.
    Type: Grant
    Filed: June 9, 1975
    Date of Patent: August 30, 1977
    Assignee: Optische Werke G. Rodenstock
    Inventor: Wilhelm Krahn