Patents by Inventor Takeo Koitabashi

Takeo Koitabashi 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: 4680252
    Abstract: A silver halide light-sensitive photographic material for radiographic use comprising a transparent support and a silver halide emulsion layer on both sides thereof such that the blue light transmission density difference between the support and the silver halide layer is .gtoreq.0.35 and .ltoreq.0.60.
    Type: Grant
    Filed: July 19, 1985
    Date of Patent: July 14, 1987
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Akio Suzuki, Takeo Koitabashi, Masatoshi Iwata, Hisashi Yamaguchi, Syoji Matsuzaka
  • Patent number: 4514491
    Abstract: A photosensitive silver halide emulsion comprising photosensitive silver halide grains which essentially consists of monodisperse globular-shaped grains. The grains may be prepared by adding a silver halide solvent to a silver halide emulsion containing monodisperse silver halide grains of regular crystal habit at a time between the complete formation of the monodisperse silver halide grains of regular crystal habit and before commencement of chemical sensitization.
    Type: Grant
    Filed: May 3, 1982
    Date of Patent: April 30, 1985
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takeo Koitabashi, Syoji Matsuzaka, Yuji Hotta, Masatoshi Iwata
  • Patent number: 4497895
    Abstract: There is disclosed a method for preparing a silver halide photographic emulsion by use of an ammoniacal silver nitrate solution in a double-jet manner, characterized in that the method comprises the step of maintaining the ratio between the maximum and minimum solubility of the silver halide in a silver halide photographic emulsion at 3 or less after 1/10 of the total amount of the solution containing silver halide has been used.The method according to the present invention provides a monodispersed silver halide photographic emulsion which has a high sensitivity, i.e., which comprises silver halide having a relatively large crystal size.
    Type: Grant
    Filed: July 30, 1982
    Date of Patent: February 5, 1985
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Syoji Matsuzaka, Takeo Koitabashi, Yoshihiro Haga, Akio Suzuki, Hiroaki Shiozawa
  • Patent number: 4477560
    Abstract: There is disclosed a light-sensitive silver halide color photographic material, comprising a group of silver halide emulsion layers constituting the same color sensitive layer, said group of emulsion layers consisting of at least two silver halide emulsion layers with different light sensitivities, the layer with the highest sensitivity incorporating at least one kind of a compound having a non-diffusion type coupler component and a scavenger component for an oxidized product of a color forming developing agent in an amount of 1 to 5 mole % per mole of the silver halide in the layer containing said compound.The light-sensitive silver halide color photographic material according to the present invention has high sensitivity and can provide high image quality with a broad latitude.
    Type: Grant
    Filed: December 13, 1982
    Date of Patent: October 16, 1984
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takeo Koitabashi, Kiyoshi Yamashita, Toshifumi Iijima
  • Patent number: 4446228
    Abstract: A silver halide photographic material comprising a base having formed thereon a silver halide emulsion layer substantially made of two or more monodisperse emulsions having different average grain sizes in the range of from 0.2 to 3.0 .mu.m is disclosed. The grain size distribution curve of the silver halide grains in said emulsion layer has two or more peaks, and the distance between the highest peak and the second highest peak is at least 0.3 .mu.m.
    Type: Grant
    Filed: April 27, 1982
    Date of Patent: May 1, 1984
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Chika Honda, Masatoshi Iwata, Takeo Koitabashi
  • Patent number: 4444877
    Abstract: A light-sensitive silver halide emulsion is disclosed, which comprises cores composed of silver halide grains and shells covering the cores. The cores consist essentially of silver halide containing silver iodide, and the shells consist essentially of silver bromide, silver chloride or silver chlorobromide excluding silver iodide. The shells have a thickness of from 0.01 to 0.1.mu.. This light-sensitive silver halide emulsion has high sensitivity and superior covering power.
    Type: Grant
    Filed: February 9, 1982
    Date of Patent: April 24, 1984
    Assignee: Konishiroku Photo Ind. Co., Ltd.
    Inventors: Takeo Koitabashi, Yoshihiro Haga, Syoji Matsuzaka
  • Patent number: 4401754
    Abstract: A silver halide photographic emulsion characterized in that it comprises silver halide grains which are reduction-sensitized during the process of growing said grains and containing a compound of the formula ##STR1## wherein R.sub.1 and R.sub.2 are selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an acyl group and a cycloalkyl group and R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkoxy group, an acyl group, a carboxyl group, an aldehyde group, an amino group, a sulfo group, an alkylthio group, an acylamino group, an aryloxy group, an arylthio group, an alkylamino group, an alkoxycabonyl group and a sulfonamide group. The emulsion exhibits both high sensitivity and improved stability as compared with prior art compositions.
    Type: Grant
    Filed: October 30, 1981
    Date of Patent: August 30, 1983
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Akio Suzuki, Hiroaki Shiozawa, Takeo Koitabashi, Hideki Takiguchi
  • Patent number: 4350758
    Abstract: A photographic emulsion containing composite crystals of (a) silver halide and (b) copper halide or a solid solution crystal of copper halide and silver halide is found to be sufficiently photosensitive and developable. In such a photographic emulsion, the amount of silver used can significantly be decreased.
    Type: Grant
    Filed: November 3, 1980
    Date of Patent: September 21, 1982
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takeo Koitabashi, Syozi Matsuzaka, Toshifumi Iijima, Tetsuya Harada
  • Patent number: 4349622
    Abstract: There are provided a photographic silver halide emulsion which comprises composite silver halide crystals consisting essentially of multi-faceted silver iodobromide crystals containing 15-40 mole % of silver iodide and silver halide crystals containing not more than 10 mole % of silver iodide, said silver halide crystals being combined as epitaxial silver halide crystals with said multi-faceted silver iodobromide crystals, at least half of the facetes of said multi-faceted crystals being substantially free of said epitaxial crystals and the amount of said epitaxial crystals being limited to not more than 75 mole % based on the total silver halide forming said composite crystals, a silver halide emulsion comprising silver halide grains consisting essentially of silver iodobromide containing 15-40 mole % of silver iodide substantially homogeneously distributed therein, and a process for preparing the same.
    Type: Grant
    Filed: May 29, 1980
    Date of Patent: September 14, 1982
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takeo Koitabashi, Syozi Matsuzaka, Tashifumi Iijima
  • Patent number: 4232118
    Abstract: A photographic material having a light-sensitive silver halide emulsion layer containing a mixture of monomethinecyanine dyes is disclosed. The mixture is particularly suitable for minimizing fog in the finished product.
    Type: Grant
    Filed: March 1, 1979
    Date of Patent: November 4, 1980
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Ken Okauchi, Takeo Koitabashi, Noboru Fujimori
  • Patent number: 4147547
    Abstract: A light-sensitive silver halide photographic material having improved anti-fogging properties is described.
    Type: Grant
    Filed: January 10, 1978
    Date of Patent: April 3, 1979
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takeo Koitabashi, Noboru Fujimori, Shigemasa Itoh
  • Patent number: 4049456
    Abstract: A light-sensitive silver halide photographic material is disclosed which contains a support and a red-sensitive layer. The red-sensitive layer contains at least one sensitizing dye selected from a particular group of sensitizing dyes and at least one sensitizing dye selected from a second group of sensitizing dyes and at least one of a particular group of compounds.
    Type: Grant
    Filed: April 7, 1976
    Date of Patent: September 20, 1977
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takeo Koitabashi, Hideo Akamatsu
  • Patent number: 4045230
    Abstract: A light-sensitive silver halide color photographic material comprising at least a support and a red-sensitive, silver halide-containing layer containing at least one sensitizing dye of the following general formula I ##STR1## AND AT LEAST ONE SENSITIZING DYE OF THE FOLLOWING GENERAL FORMULA II ##STR2##
    Type: Grant
    Filed: March 16, 1976
    Date of Patent: August 30, 1977
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takeo Koitabashi, Hideo Akamatsu, Noboru Fujimori