Direct positive photographic light-sensitive materials
US4643965A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1984 |
| Grant date | Feb 17, 1987 |
| Priority date | — |
| Expiry date | May 24, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/141
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A direct positive photographic light-sensitive material is described, comprising a support and at least one internal latent image type silver halide emulsion layer containing core/shell type silver halide grains which are composed of a silver halide core subjected to at least one of doping with metal ions and chemical sensitization, and a silver halide shell covering at least sensitivity sites of said core, and a binder, wherein said core/shell type silver halide grains consist of two or more kinds of grains each having a different average grain size, and the core of the core/shell type silver halide grains having a larger average grain size is doped with a larger amount of lead ions, cadmium ions, or Group VIII metal ions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.