US4229525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for improving image-sharpness of photographic silver halide material
Assignee: Fujifilm Holdings Corp
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Filing: 1976-11-29
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Granted: 1980-10-21
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Expires: 1996-11-29
Abstract
Abstract A photographic silver halide emulsion containing silver halide grains having an average grain size of from 0.3 to 3.0 microns in diameter as a light sensitive element in a dispersing medium and additionally containing super fine grains of silver halide having an average grain size of less than 0.2 microns in diameter is disclosed.
Inventors
- 👤 Hirozo Ueda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:19
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/035; G03C2001/03564; G03C2001/03594; G03C2200/00; G03C2200/38; G03C7/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
159 words
A process for improving image-sharpness of a photosensitive material comprising a support having thereon at least one layer containing a negative working photographic emulsion containing randomly dispersed light-sensitive silver halide grains having an average grain size of from 0.3 to 3.0 microns in diameter, as the main silver halide image-yielding component thereof in a photographically compatible dispersing medium, which process comprises incorporating at random in said emulsion prior to adding any sensitizing dye to said emulsion super-fine grains of silver halide having an average grain size of less than 0.2 microns in diameter in said emulsion in an amount of from 10 g to 50 g per 100 g of said dispersing medium, said super-fine grains of silver halide co-existing with said light-sensitive silver halide grains and being substantially transparent to visible rays and contributing very little to the formation of an image directly, whereby said emulsion exhibits increased image sharpness without a significant decrease in speed and/or gradation.
Claim 2
Dependent Claim
159 words
A process for improving image-sharpness of a photosensitive material comprising a support having thereon at least one layer containing a negative working photographic emulsion containing randomly dispersed light-sensitive silver halide grains having an average grain size of from 0.3 to 3.0 microns in diameter, as the main silver halide image-yielding component thereof in a photographically compatible dispersing medium, which process comprises incorporating at random in said emulsion prior to adding any sensitizing dye to said emulsion super-fine grains of silver halide having an average grain size of less than 0.2 microns in diameter in said emulsion in an amount of from 10 g to 50 g per 100 g of said dispersing medium, said super-fine grains of silver halide co-existing with said light-sensitive silver halide grains and being substantially transparent to visible rays and contributing very little to the formation of an image directly, whereby said emulsion exhibits increased image sharpness without a significant decrease in speed and/or gradation.
Claim 3
Dependent Claim
27 words
The process of claim 1, wherein a sensitizing dye is added to said photographic emulsion after said super-fine grains of silver halide are incorporated in the emulsion.
Claim 4
Dependent Claim
11 words
The process of claim 1, wherein the dispersing medium is gelatin.
Claim 5
Dependent Claim
18 words
The process of claim 3, wherein said prepared photographic silver halide emulsion is free from spectral sensitizing dye.
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) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |