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US3615573A
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Direct-positive composition containing individually and differently fogged silver halide emulsions
Assignee: Eastman Kodak Co
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Filing: 1968-09-09
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Granted: 1971-10-26
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Expires: 1988-09-09
Abstract
Abstract This invention relates to direct-positive, photographic compositions. In one aspect, this invention relates to directpositive, chemically fogged silver halide compositions having extended exposure latitude. In another aspect, this invention relates to direct-positive, silver halide compositions having the ability to produce discrete, high-contrast steps over the exposure range of the photographic composition.
Inventors
- 👤 Albert C Smith Jr
- 👤 Bernard D Illingsworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:54
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/485; G03C1/48515; Y; Y10; Y10S; Y10S430/00; Y10S430/141
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
40 words
A direct-positive, photographic element according to claim 1 comprising three individual silver halidE emulsions which have been individually fogged to substantially different fog levels whereby a Density vs. Log of Exposure curve will exhibit three discrete steps in said curve.
Claim 2
Dependent Claim
16 words
A direct-positive, photographic element according to claim 1 wherein said emulsions have been reduction- and gold-fogged.
Claim 3
Dependent Claim
29 words
A direct-positive, photographic element according to claim 1 wherein said emulsions fogged to substantially different fog levels are present in admixture in a single layer in said photographic element.
Claim 4
Dependent Claim
48 words
A direct-positive, photographic element according to claim 1 wherein each of said fogged emulsions individually has a grain size distribution wherein at least 95 percent, by weight, of the silver halide grains of said emulsions have a size which is within 40 percent of the mean grain size.
Claim 5
Dependent Claim
38 words
A direct-positive, photographic element according to claim 1 wherein said fogged, silver halide emulsions comprise an organic electron acceptor which has an anodic polarographic potential and a cathodic polarographic potential which, when added together, give a positive sum.
Claim 6
Dependent Claim
33 words
A direct-positive, photographic element according to claim 1 wherein said chemically fogged, silver halide emulsions are blue-sensitive whereby it will provide a reversal image when exposed to blue light, developed, fixed and washed.
Claim 7
Dependent Claim
31 words
A direct-positive element according to claim 1 wherein a sufficient number of individually fogged, silver halide emulsions are present in said element to provide extended exposure latitude in said photographic element.
Claim 8
Dependent Claim
28 words
A direct-positive element according to claim 1 whereby a Density vs. Log of Exposure curve of said element will exhibit at least two discrete steps in said curve.
Claim 9
Dependent Claim
17 words
A direct-positive element according to claim 7 wherein said silver halide emulsions have been reduction- and gold-fogged.
Claim 10
Dependent Claim
52 words
In a method of making a chemically fogged, direct-positive silver halide emulsion, the improvement comprising (1 ) individually chemically fogging at least two separate silver halide emulsions to form direct-positive silver halide emulsions of substantially different light-exposure sensitivity and (2 ) forming a composite emulsion from said individually fogged silver halide emulsions.
Claim 11
Dependent Claim
38 words
A method according to claim 11 wherein one of said silver halide emulsions is chemically fogged to provide a light-exposure speed at least about 0.4 log E greater than another of said chemically fogged, direct-positive silver halide emulsions.
Claim 12
Dependent Claim
32 words
A process according to claim 11 wherein said silver halide emulsions each have 95 percent, by weight, of their constituent silver halide grains within about 40 percent of the means grain size.
Claim 13
Dependent Claim
19 words
A process according to claim 11 wherein said composite emulsion is formed by blending said fogged, silver halide emulsions.
Claim 14
Dependent Claim
31 words
A process according to claim 11 wherein each of said separate silver halide emulsions has an average constituent grain of substantially the same size and which is less than 2 microns.
Claim 15
Dependent Claim
15 words
A process according to claim 11 wherein said silver halide emulsions are reduction- and gold-fogged.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |