Patents by Inventor Hilary G. Sillitto

Hilary G. Sillitto 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).

  • Zoom lens
    Patent number: 5151820
    Abstract: A zoom lens, for use in a telescope at infra-red wavelengths or single wavelength visible light, provides a magnification which may be adjusted to either of two predetermined values. The lens comprises a pair (14) of similar elements (15, 16) fixed relative to one another and each having an aspheric convex surface with the aspheric surfaces of the pair of elements outermost. The pair of elements (14) is located between the two image planes formed in the telescope and is movable between two conjugate positions.
    Type: Grant
    Filed: May 2, 1991
    Date of Patent: September 29, 1992
    Assignee: GEC Ferranti Defence Systems Limited
    Inventors: Hilary G. Sillitto, Alison B. Lessels