Patents by Inventor Asao Nakatsuka

Asao Nakatsuka 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).

  • Patent number: 4267250
    Abstract: In a color diffusion transfer photographic element containing at least one dye-releasing redox compound-containing layer associated with a silver halide photographic emulsion and capable of releasing a diffusible dye as a result of a redox reaction with the oxidation product of a developing agent produced by the development of silver halide with an alkaline processing solution, and at least one layer containing an antistain agent, the improvement which comprises said dye-releasing redox compound-containing layer associated with said silver halide photographic emulsion being spaced from the adjacent interlayer containing said antistain agent by a spacer layer essentially containing a hydrophilic colloid or by a silver halide emulsion layer having substantially the same spectral sensitivity as that of the associated silver halide emulsion.
    Type: Grant
    Filed: October 11, 1979
    Date of Patent: May 12, 1981
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Seiki Sakanoue, Kokichi Waki, Motohiko Tsubota, Osamu Takahashi, Asao Nakatsuka