The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 05, 1989
Filed:
Aug. 06, 1987
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
In an internal latent image type direct positive silver halide emulsion containing core/shell type silver halide grains wherein at least light-sensitive sites of the silver halide internal core which has been subjected to doping with metal ions or chemical sensitization, or both, is covered with a silver halide outer shell, the improvement wherein a photographic additive which is adsorbed on silver halide in said emulsion or interacts with silver ion, said additive being a compound which functions to change the crystal form or particle size of the silver halide grains in the case of the formation thereof or acts as a sensitizer or a sensitizing assistant in the case of chemically sensitizing the core particles but has a harmful influence on photographic properties if it remains after use of it, is deactivated by a deactivator prior to completion of the formation of said core/shell type silver halide grains or completion of surface chemical ripening of said grains. A process for producing the above internal latent image type direct positive silver halide emulsion is also disclosed.