Patents by Inventor Yoshitaka Yamada

Yoshitaka Yamada 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).

  • Silver halide color photographic material of high sensitivity and improved granularity
    Patent number: 4701404
    Abstract: A silver halide color photographic material having blue-, green- and red-sensitive silver halide emulsion layers coated on a support is provided, each of said layers being composed of a plurality of sub-layers having different sensitivities. In said material, at least a red-sensitive silver halide emulsion sub-layer having high sensitivity is provided between a first green-sensitive silver halide emulsion sub-layer of high sensitivity and a second green-sensitive silver halide emulsion sub-layer having a lower sensitivity than said first green-sensitive sub-layer, said first green-sensitive sub-layer and/or said red-sensitive sub-layer with high sensitivity giving a maximum color density of formed dye in said material higher than 0.6 but not exceeding 1.3.
    Type: Grant
    Filed: September 13, 1985
    Date of Patent: October 20, 1987
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Toshifumi Iijima, Yoshitaka Yamada, Kenji Kumashiro, Takashi Kamio, Shinya Shimura
  • Dye-sensitized light-sensitive core/shell silver halide photographic material
    Patent number: 4701405
    Abstract: There is disclosed a light-sensitive silver halide photographic material which has at least one silver halide emulsion layer on a support, the silver halide emulsion layer includes substantially monodispersed core/shell type silver halide grains, and the silver halide grains are those which have been sensitized with a combination of at least one of sensitizing dyes represented by the following formulae (I) and (II): ##STR1## wherein R.sub.1 to R.sub.8, Y.sub.1 to Y.sub.8, X.sub.1.sup..crclbar., X.sub.2.sup..crclbar., m and n have the same meanings as defined in the specification.
    Type: Grant
    Filed: August 26, 1985
    Date of Patent: October 20, 1987
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Hideki Takiguchi, Yoshitaka Yamada, Hirofumi Ohtani, Hiroshi Kashiwagi
  • Light-sensitive silver halide photographic material
    Patent number: 4481288
    Abstract: There is disclosed a light-sensitive silver halide photographic material having at least one silver halide emulsion layer constituted of a plural number of layers which are substantially the same in color to which they are sensitive but different in sensitivity provided on a support, which comprises a layer having the highest sensitivity among the plural number of layers with different sensitivities which contains at least two kinds of substantially mono-dispersed silver halide grains with different average grain sizes.The light-sensitive silver halide photographic material according to this invention is high in sensitivity and excellent in graininess of dye image.
    Type: Grant
    Filed: October 14, 1983
    Date of Patent: November 6, 1984
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Yoshitaka Yamada, Toshifumi Iijima, Toshihiko Yagi, Yoshihiro Haga, Kenji Kumashiro, Hiroshi Menjo