Patents by Inventor William M. Webster, Jr.

William M. Webster, Jr. 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).

  • Sheet-material authenticated item with reflective-diffractive authenticating device
    Patent number: 4892385
    Abstract: An improved authenticating device comprises a substrate bonded to the sheet material, the substrate having a reflective diffractive structure formed as a relief pattern on a viewable surface thereof, and a transparent material covering the structure. Specified grating parameters of the diffractive structure, obtainable at low cost, result in peculiar, but easily discernable, optical color properties that cannot be copied by color copying machines.
    Type: Grant
    Filed: February 19, 1981
    Date of Patent: January 9, 1990
    Assignee: General Electric Company
    Inventors: William M. Webster, Jr., John P. Russell