US3870522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fogged, direct-positive emulsion containing heterodisperse and irregular composite silver halide grains
Assignee: Agfa Gevaert AG
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Filing: 1973-05-16
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Granted: 1975-03-11
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Expires: 1993-05-16
Abstract
Abstract A silver salt emulsion for the preparation of direct-positive images by imagewise exposure and development of developable fog light-sensitive material wherein the developable fog is destroyed on exposure to light and in which at least one fogged silver salt emulsion contains heterodispersed and irregular grains containing ripening nuclei and at least 10 percent of the grains have a size which deviates by at least 40 percent from the average grain diameter.
Inventors
- 👤 Erik Moisar
- 👤 Sieghart Klotzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:42
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/485; G03C1/48515
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
103 words
A PHOTOGRAPHIC MATERIAL COMPRISING A SUPPORT AND A LIGHT-SENSITIVE LAYER CONTAINING AT LEAST ONE FOGGED LIGHTSENSITIVE DIRECT POSITIVE SILVER HALIDE EMULSION LAYER BEING SPONTANEOUSLY DEVELOPABLE WITH SILVER HALIDE EMULSION LAYER BEING INTERNAL ELECTRON TRAPS WHEREIN THE IMPROVEMENT COMPRISES SILVER HALIDE GRAINS OF THE FOGGED EMULSION ARE HETERODISPERSED AND IRREGULAR HAVING CORES WHICH CONTAINS INTERVAL ELECTRON TRAPS AND OUTER SHELLS OF SILVER HALIDE ON THE CORES AND HAVING A GRAIN SIZE DISTRIBUTION WHEREIN AT LEAST 10 PERCENT OF THE GRAINS HAVE A SIZE WHICH DEVIATES BY AT LEAST 40 PERCENT FROM THE AVERAGE GRAIN DIAMETER, SAID OUTER SHELLS OF SILVER HALIDE HAVE BEEN FOGGED.
Claim 2
Dependent Claim
103 words
A PHOTOGRAPHIC MATERIAL COMPRISING A SUPPORT AND A LIGHT-SENSITIVE LAYER CONTAINING AT LEAST ONE FOGGED LIGHTSENSITIVE DIRECT POSITIVE SILVER HALIDE EMULSION LAYER BEING SPONTANEOUSLY DEVELOPABLE WITH SILVER HALIDE EMULSION LAYER BEING INTERNAL ELECTRON TRAPS WHEREIN THE IMPROVEMENT COMPRISES SILVER HALIDE GRAINS OF THE FOGGED EMULSION ARE HETERODISPERSED AND IRREGULAR HAVING CORES WHICH CONTAINS INTERVAL ELECTRON TRAPS AND OUTER SHELLS OF SILVER HALIDE ON THE CORES AND HAVING A GRAIN SIZE DISTRIBUTION WHEREIN AT LEAST 10 PERCENT OF THE GRAINS HAVE A SIZE WHICH DEVIATES BY AT LEAST 40 PERCENT FROM THE AVERAGE GRAIN DIAMETER, SAID OUTER SHELLS OF SILVER HALIDE HAVE BEEN FOGGED.
Claim 3
Dependent Claim
102 words
A photographic material comprising a support and a light-sensitive layer containing at least one fogged light-sensitive direct positive silver halide emulsion layer being spontaneously developable with silver halide grains containing internal electron traps wherein the improvement comprises silver halide grains of the fogged emulsion are heterodispersed and irregular having cores which contains interval electron traps and outer shells of silver halide on the cores and having a grain size distribution wherein at least 10 percent of the grains have a size which deviates by at least 40 percent from the average grain diameter, said outer shells of silver halide have been fogged.
Claim 4
Dependent Claim
102 words
A photographic material comprising a support and a light-sensitive layer containing at least one fogged light-sensitive direct positive silver halide emulsion layer being spontaneously developable with silver halide grains containing internal electron traps wherein the improvement comprises silver halide grains of the fogged emulsion are heterodispersed and irregular having cores which contains interval electron traps and outer shells of silver halide on the cores and having a grain size distribution wherein at least 10 percent of the grains have a size which deviates by at least 40 percent from the average grain diameter, said outer shells of silver halide have been fogged.
Claim 5
Dependent Claim
29 words
The material of claim 1 wherein at least 20 percent of the grains have a grain size which deviates by at least 40 percent from the average grain diameter.
Claim 6
Dependent Claim
23 words
The material of claim 1 wherein the silver halide is silver bromide which may contain up to 20 mols percent of silver iodide.
Claim 7
Dependent Claim
35 words
The material of claim 1 wherein the silver halide grains are fogged with a reducing agent in the presence of a gold compound or a compound of another metal which is more electro-positive than silver.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |