Patents by Inventor Francis John Evans

Francis John Evans 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).

  • Performance of photographic emulsions at high silver ion concentrations
    Patent number: 5989795
    Abstract: This invention relates to a photographic recording material comprising a support and a photosensitive chemically sensitized silver halide emulsion layer, containing a sensitizing dye selected from the group consisting of oxonal dyes, merocyanine dyes, and cyanine dyes having a net negative charge, and which has a pH value between about 2 to about 5 and a pAg value between about 1 to about 4.7.
    Type: Grant
    Filed: May 21, 1992
    Date of Patent: November 23, 1999
    Assignee: Eastman Kodak Company
    Inventors: Francis John Evans, Arthur Herman Herz