Patents by Inventor Robert T. Shannahan

Robert T. Shannahan 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).

  • Color developer for diffusion transfer
    Patent number: 4066457
    Abstract: A diffusion transfer photographic element containing a lipophilic, non-diffusing color former in a silver halide emulsion layer, or in a layer adjacent thereto, is developed by using a water- and alkali-soluble color developer capable of coupling with the color former to form a diffusible coupled product, the color developer being coated with the silver halide emulsion layer or in any layer of the photographic element or being in an alkaline developing solution.
    Type: Grant
    Filed: December 10, 1974
    Date of Patent: January 3, 1978
    Assignee: GAF Corporation
    Inventors: Theodore Panasik, Felix Viro, Burton H. Waxman, Robert T. Shannahan