Patents by Inventor Berkeley M. Ferro

Berkeley M. Ferro 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).

  • Identification matter
    Patent number: 4500116
    Abstract: A credential, such as a passport or an identification card, is provided, for example by impregnation or coating, with a phosphorescent composition which includes at least two phosphorescence activators which exhibit different emission characteristics both with respect to wavelength and lifetime so that, when the composition is irradiated, the initial afterglow changes color, for example from green to blue.
    Type: Grant
    Filed: July 14, 1980
    Date of Patent: February 19, 1985
    Assignee: The Post Office
    Inventors: Berkeley M. Ferro, Aubrey D. Walker