Patents by Inventor Yasuo Tosaka

Yasuo Tosaka 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: 4268621
    Abstract: A light-sensitive silver halide photographic material of internal latent image type for use in the formation of a direct positive image containing a compound of the following general formula (I) or (II):General formula (I) ##STR1## General formula (II) ##STR2## The photographic material can be developed after a shortened induction period, can yield good positive images that are free from stain when undergoing fogging development, and can yield good direct positive images with a high maximum density and a low minimum density. The photographic material forms a direct positive image when subjected, after imagewise exposure, to an overall light exposure or development in the presence of a fogging agent and can be developed by surface development.
    Type: Grant
    Filed: July 27, 1979
    Date of Patent: May 19, 1981
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Keiji Ogi, Takashi Sasaki, Kenichiro Okaniwa, Yasuo Tosaka