Patents by Inventor Richard C. Duffus

Richard C. Duffus 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).

  • Rotatable shear plate interferometer
    Patent number: 4786175
    Abstract: A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: November 22, 1988
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Richard C. Duffus