Direct positive photographic materials and a method of forming direct positive images
US4948712A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1988 |
| Grant date | Aug 14, 1990 |
| Priority date | — |
| Expiry date | Jun 7, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/156
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides (1) direct positive photographic photosensitive materials in which at least one type of FR compound which releases fogging agent or development accelerator or a precursor thereof in accordance with the amount of silver developed when the silver halide is being developed is included in a direct positive photographic material comprising at least one layer of non-pre-fogged internal latent image type silver halide emulsion on a support, and (2) a method of forming direct positive images of which the distinguishing features are that in a method for the formation of direct positive images in which a direct positive photographic photosensitive material comprising at least one layer of non-pre-fogged internal latent image forming silver halide emulsion on a support is processed, after image exposure, in a surface developer, at least one type of FR compound which releases fogging agent or development accelerator or precursors thereof is included in the said photographic mateiral, and that the said photosensitive material is subjected to a fogging process and to a development process during and/or after the said fogging process. It is possible by means of this inventi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.