Patent US983811A successfully refreshed from Google Patents.
Patent US3930859A successfully refreshed from Google Patents.
US3930859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic process, system, recording medium and monoweb
Assignee: Bell and Howell Co
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Filing: 1973-07-20
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Granted: 1976-01-06
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Expires: 1993-07-20
Abstract
Abstract An improved photographic processing system and process are provided. The system includes a novel photographic recording medium comprising a layer of silver halide emulsion, a barrier layer disposed on a surface thereof, the barrier layer being soluble in aqueous alkali but insoluble in water and acidic media, and an acidic developer disposed as a layer on the outer surface of the barrier layer or mixed therewith. The developer is activatable at an alkaline pH. A novel processing web comprising a support containing an alkali and a free water source is also provided, which web is adapted for contacting the layer containing developer to initiate development of the silver halide. The developer thus is isolated from alkali and from the emulsion prior to developing. The process includes exposure of the recording medium, followed by the described contacting for development of a visible image. Nucleating and complexing agents can be included in the web, to remain with the web, to provide a positive print by diffusion transfer and/or to aid in stabilization of the photographic emulsion.
Inventors
- 👤 Richard A. Corrigan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:43
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/02; G03C8/04; G03C8/06; G03C1/00; G03C1/005; G03C1/06; G03C1/42; G03C5/00; G03C5/26; G03C5/261
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
83 words
An improved photographic recording medium comprising: a layer of silver halide emulsion; a barrier layer, soluble in aqueous alkali but insoluble in water and acidic media, disposed on a surface of said emulsion layer, said barrier layer comprising a material selected from the group consisting of: a monoalkyl ester-containing copolymer derivative of methyl ethyl ether-maleic anhydride copolymer, and a vinyl acetate-maleic anhydride copolymer; and an acidic developer for said silver halide with said barrier layer, said developer being activatable at an alkaline pH.
Claim 2
Dependent Claim
83 words
An improved photographic recording medium comprising: a layer of silver halide emulsion; a barrier layer, soluble in aqueous alkali but insoluble in water and acidic media, disposed on a surface of said emulsion layer, said barrier layer comprising a material selected from the group consisting of: a monoalkyl ester-containing copolymer derivative of methyl ethyl ether-maleic anhydride copolymer, and a vinyl acetate-maleic anhydride copolymer; and an acidic developer for said silver halide with said barrier layer, said developer being activatable at an alkaline pH.
Claim 3
Dependent Claim
31 words
The improved recording medium of claim 1 wherein said developer is formed as a layer disposed on the surface of said barrier layer opposite the barrier layer surface contacting said emulsion.
Claim 4
Dependent Claim
21 words
The improved recording medium of claim 1 wherein said copolymer comprises monoalkyl ester-containing copolymer derivative of methyl ethyl ether-maleic anhydride copolymer.
Claim 5
Dependent Claim
16 words
The improved recording medium of claim 1 wherein said copolymer comprises a vinyl acetate-maleic anhydride copolymer.
Claim 6
Dependent Claim
139 words
An improved photographic process, which process comprises: exposing a photographic recording medium to a pattern of light, said medium comprising: a layer of silver halide emulsion; a barrier layer, soluble in aqueous alkali but insoluble in water and acidic media, disposed on a surface of said emulsion layer, said barrier layer comprising a material selected from the group consisting of: a monoalkyl ester-containing copolymer derivative of methyl ethyl ether-maleic anhydride copolymer, and a vinyl acetate-maleic anhydride copolymer; and an acidic developer being activatable at an alkaline pH: contacting said developer with a processing web free of alkali-activatable silver halide developer comprising a support containing an alkali and a free water source, to activate said developer and cause penetration thereof through said barrier layer for development of said silver halide; and terminating said contacting and recovering said developed recording medium.
Claim 7
Dependent Claim
139 words
An improved photographic process, which process comprises: exposing a photographic recording medium to a pattern of light, said medium comprising: a layer of silver halide emulsion; a barrier layer, soluble in aqueous alkali but insoluble in water and acidic media, disposed on a surface of said emulsion layer, said barrier layer comprising a material selected from the group consisting of: a monoalkyl ester-containing copolymer derivative of methyl ethyl ether-maleic anhydride copolymer, and a vinyl acetate-maleic anhydride copolymer; and an acidic developer being activatable at an alkaline pH: contacting said developer with a processing web free of alkali-activatable silver halide developer comprising a support containing an alkali and a free water source, to activate said developer and cause penetration thereof through said barrier layer for development of said silver halide; and terminating said contacting and recovering said developed recording medium.
Claim 8
Dependent Claim
30 words
The improved process of claim 5 wherein said developer is formed as a layer disposed on the surface of said barrier layer opposite the barrier layer surface contacting said emulsion.
Claim 9
Dependent Claim
21 words
The improved process of claim 5 wherein said web contains free water and a fixer for a developed silver halide image.
Claim 10
Dependent Claim
23 words
The improved process of claim 5 wherein said web contains an agent which releases free water upon chemical reaction with said developer layer.
Claim 11
Dependent Claim
21 words
The improved process of claim 5 wherein said copolymer comprises a monoalkyl ester-containing copolymer derivative of methyl ethyl ether-maleic anhydride copolymer.
Claim 12
Dependent Claim
15 words
The improved process of claim 5 wherein said copolymer comprises a vinyl acetate-maleic anhydride copolymer.
References Cited (Backward Citations)
US2698798A
Cited
US2774668A
Cited
US2819166A
Cited
US3468664A
Cited
US3179517A
Cited
US3260598A
Cited
US3419395A
Cited
US3415651A
Cited
US3518088A
Cited
US3576632A
Cited
US3729314A
Cited
US3759712A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-05 | 1979-07-07 | 1980-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-05 | 1983-07-07 | 1984-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-05 | 1987-07-07 | 1988-01-06 | $7700.00 | Window Closed / Lapsed |