Patents by Inventor Tsutomu Hamanka

Tsutomu Hamanka 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).

  • Process for forming photographic images
    Patent number: 4268616
    Abstract: A process for forming photographic images comprising a silver image and a dye image, which comprises development processing an imagewise exposed silver halide photographic light-sensitive material in the presence of a carboxy- and sulfo-free naphthalene compound wherein at least two hydrogen atoms in the naphthalene nucleus are substituted at specific positions thereof as indicated in formula (I) below, and a 3-pyrazolidone compound.
    Type: Grant
    Filed: January 18, 1980
    Date of Patent: May 19, 1981
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Junkichi Ogawa, Tsutomu Hamanka