Patents by Inventor Philip J. Wightman

Philip J. Wightman 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).

  • Selenium and iridium doped emulsions with improved properties
    Patent number: 5164292
    Abstract: The invention is generally accomplished by forming a silver halide emulsion and during precipitation adding iridium and selenium in an amount effective to decrease reciprocity failure with substantially no decrease in speed. In a preferred form, a photographic element is formed comprising of bromoiodide emulsion having about 3 to about 88 nanograms of iridium per square meter of silver halide grain surface area and about 42 to about 487 nanograms of selenium per square meter of silver halide grain surface area. It is also preferred that the iridium and selenium be added at a point after the precipitation has proceeeded to a point wherein at least half of the silver to be added is present.
    Type: Grant
    Filed: December 27, 1990
    Date of Patent: November 17, 1992
    Assignee: Eastman Kodak Company
    Inventors: Brian R. Johnson, Philip J. Wightman