Internal latent image type direct positive silver halide emulsions and process for producing the same

摘要

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.