Patent US2717833A successfully refreshed from Google Patents.
US2717833A
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Direct positive emulsions
Assignee: Unisys Corp
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Filing: 1952-05-12
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Granted: 1955-09-13
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Expires: 1972-05-12
Abstract
No abstract record available.
Inventors
- 👤 Wark Homer Albert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:18
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/485; Y; Y10; Y10S; Y10S430/00; Y10S430/141
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
115 words
IN A PROCESS FOR THE PRODUCTION OF DIRECT POSITIVE PHOTOGRAPHIC EMULSIONS ACCORDING TO WHICH A LIGHT SENSITIVE SILVER HALIDE EMULSION IS PRODUCED BY THE STEPS OF PRECIPITATION OF THE SILVER HALIDE, FIRST DIGESTION OF THE EMULSION, SHREDDING, WASHING, REMELTING AND SECOND DIGESTION, THE IMPROVEMENT WHICH COMPRISES PRECIPITATING SAID SILVER HALIDE IN THE PRESENCE OF A SOLUBLE SALT OF A METAL SELECTED FROM THE GROUP VIII OF THE PERIODIC ARRANGEMENT OF THE ELEMENTS, IN A RATIO OF THE ORDER OF 0.15 TO 393 MILLIGRAMS OF THE GROUP VIII METAL PER 100 GRAMS OF SILVER AND A METAL COMPLEXING BASIC NITROGEN COMPOUND, AND MAINTAINING THE EMULSION AT A PH NUMBER HIGHER THAN 7 THROUGHOUT SAID SECOND DIGESTION.
Claim 2
Dependent Claim
115 words
IN A PROCESS FOR THE PRODUCTION OF DIRECT POSITIVE PHOTOGRAPHIC EMULSIONS ACCORDING TO WHICH A LIGHT SENSITIVE SILVER HALIDE EMULSION IS PRODUCED BY THE STEPS OF PRECIPITATION OF THE SILVER HALIDE, FIRST DIGESTION OF THE EMULSION, SHREDDING, WASHING, REMELTING AND SECOND DIGESTION, THE IMPROVEMENT WHICH COMPRISES PRECIPITATING SAID SILVER HALIDE IN THE PRESENCE OF A SOLUBLE SALT OF A METAL SELECTED FROM THE GROUP VIII OF THE PERIODIC ARRANGEMENT OF THE ELEMENTS, IN A RATIO OF THE ORDER OF 0.15 TO 393 MILLIGRAMS OF THE GROUP VIII METAL PER 100 GRAMS OF SILVER AND A METAL COMPLEXING BASIC NITROGEN COMPOUND, AND MAINTAINING THE EMULSION AT A PH NUMBER HIGHER THAN 7 THROUGHOUT SAID SECOND DIGESTION.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-09-12 | 1959-03-14 | 1959-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-09-12 | 1963-03-14 | 1963-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-09-12 | 1967-03-14 | 1967-09-13 | $7700.00 | Window Closed / Lapsed |