Patents by Inventor Thomas R. Corwin

Thomas R. Corwin 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: 4579370
    Abstract: A protected document has a cancellation phrase, normally invisible to the human eye, which will appear if the document is copied on a color copier. The protection of these documents is improved in the following protected document. The document is made up of a substrate, first and second cancellation phrase images which form a combined cancellation phrase image printed on the substrate, first and second background images forming a combined background image printed on the substrate and a camouflage overlay image (merged with) the combined cancellation and combined background images. The first and second cancellation phrase images appear on the document when it is copied on a color copier. The two images extend the range of protection for color copy machines having multiple darkness settings.
    Type: Grant
    Filed: July 6, 1984
    Date of Patent: April 1, 1986
    Assignee: Burroughs Corporation
    Inventors: Thomas R. Corwin, William H. Mowry, Jr.