Patents by Inventor Tamotu Iwata

Tamotu Iwata 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: 5660972
    Abstract: Disclosed is a method for developing silver halide photographic photosensitive materials with a developer containing a sulfite wherein said developer contains 20 mol % or more of potassium ion based on the total alkali metal ions, 0.04 mol/l or more of bromine ion or a compound represented by the following formula (I): ##STR1## wherein R.sub.1 represents a hydroxyalkyl group having 2-10 carbon atoms and R.sub.2 and R.sub.3 each represent a hydrogen atom, an alkyl group having 1-10 carbon atoms or a hydroxyalkyl group having 2-10 carbon atoms and the developer is filtered by a filter containing physical development nuclei before, during or after development of the photosensitive materials with the developer. The method is especially effective in processing using an automatic processor. According to the present method, formation of silver sludges is effectively inhibited and thus, stain of roll and belt of the processors can be prevented.
    Type: Grant
    Filed: March 14, 1995
    Date of Patent: August 26, 1997
    Assignee: Mitsubishi Paper Mills Limited
    Inventors: Hideto Kiyama, Tamotu Iwata, Yukinao Kawamata, Susumu Baba
  • Patent number: 5344741
    Abstract: The present invention provides a developer for silver halide photographic light-sensitive materials which provides super-high contrast and is improved in stability with time. This developer contains at least (1) a developing agent, (2) 10 g/l or more of a hydroquinonemonosulfonate, (3) 0.3 mol/l or more of a sulfite and (4) an amino compound in an amount necessary to accelerate enhancement of contrast and has a pH of 10.5-12.3.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: September 6, 1994
    Assignee: Mitsubishi Paper Mills Limited
    Inventors: Tamotu Iwata, Seiichi Sumi
  • Patent number: 4153458
    Abstract: A photographic binder prepared by heating a mixed aqueous solution of styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer and polyvinyl alcohol in acidic state makes it possible to coat a photographic coating liquid for forming photographic layers in the same manner as in the case of using gelatin and furthermore gives excellent physical properties to the resultant photographic layers.
    Type: Grant
    Filed: November 1, 1977
    Date of Patent: May 8, 1979
    Assignee: Mitsubishi Paper Mills, Ltd.
    Inventors: Shigeru Iguchi, Tamotu Iwata, Tetsuo Yano
  • Patent number: 4119463
    Abstract: A photographic binder prepared by heating a mixed aqueous solution of styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer and polyvinyl alcohol in acidic state makes it possible to coat a photographic coating liquid for forming photographic layers in the same manner as in the case of using gelatin and furthermore gives excellent physical properties to the resultant photographic layers.
    Type: Grant
    Filed: April 20, 1976
    Date of Patent: October 10, 1978
    Assignee: Mitsubishi Paper Mills, Ltd.
    Inventors: Shigeru Iguchi, Tamotu Iwata, Tetsuo Yano