Patents by Inventor Hiroaki Shiozawa

Hiroaki Shiozawa 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: 4840888
    Abstract: There is disclosed a light-sensitive silver halide photographic material having at least one silver halide emulsion layer on a support, which comprises the light-sensitive photographic material contains light-sensitive silver halide grains, metal salt grains having internal fog and a polyhydric alcohol having at least two hydroxyl groups having a melting point of 40.degree. C. or higher.
    Type: Grant
    Filed: October 27, 1988
    Date of Patent: June 20, 1989
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Mikio Kawasaki, Hiroaki Shiozawa, Kakujulo Fukuouji, Kouji Ono
  • 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: 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