Patents by Inventor Bernhard Doctor

Bernhard Doctor 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: 4824223
    Abstract: A projection objective with variable focal length is provided, consisting of a front member (F) with negative refractive power and a multiple-lens basic objective (G) with positive refractive power, between which a multiple-lens variator (V) displaceable in the direction of the optical axis and with positive refractive power is disposed, with said objective having seven self-contained lenses (L1-L7) separated from each other by air spaces and free of cemented surfaces, whereof the front member (F) consists of one single lens (1) with negative refractive power, the basic objective consists of a Cookes or Taylor lens (L5, L6, L7) and the variator (V) likewise consists of a Cookes or Taylor lens (L2, L3, L4).
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: April 25, 1989
    Assignee: Docter-Optic-Wetzlar GmbH
    Inventors: Bernhard Doctor, Ingolf Menzel