Patents by Inventor Tawara Kumamura

Tawara Kumamura 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: 4840882
    Abstract: In a heat-developable color light-sensitive material comprising a support having thereon at least two light-sensitive layers each comprising a light-sensitive silver halide, organic silver salt, dye-donating material capable of releasing or forming a diffusible dye by heat development, reducing agent, and hydrophilic binder, said at least two light-sensitive layers differing from each other in the color sensitivity of said light-sensitive silver halide and in the hue of said diffusible dye, said heat-developable color light-sensitive material, wherein at least one of said light-sensitive layer(s) containing said dye-donating materials are hardened with a hardening agent for said hydrophilic binder. The foregoing heat-developable color light-sensitive material prevents diffusion of the dye-donating material and reduces or prevents the color-crossover phenomenon. Transferability of the dye is also improved as is scratch resistance of the photographic component layers.
    Type: Grant
    Filed: August 31, 1988
    Date of Patent: June 20, 1989
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Masaru Iwagaki, Takashi Sasaki, Tawara Kumamura, Fumio Ishii, Kunihiro Koshizuka