High-speed direct-positive photographic elements utilizing core-shell emulsions
US5532119A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1993 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Mar 25, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2001/091
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Direct-positive photographic elements are comprised of a support and a silver halide emulsion layer containing core-shell silver halide grains comprising a chemically sensitized core and a chemically sensitized shell, wherein at least one of the core and the shell comprises a band of dopant and wherein the dopant is hexacyano ruthenium (II). Preferably, the shell of the core-shell grains is chemically sensitized with both a gold-containing chemical sensitizing agent and a sulfur-containing chemical sensitizing agent and the weight ratio of the gold-containing chemical sensitizing agent to the sulfur-containing chemical sensitizing agent is at least about two to one.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.