US2984567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for elimination of reversal reexposure in processing photographic films
Assignee: Eastman Kodak Co
•
Filing: 1957-11-29
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Granted: 1961-05-16
•
Expires: 1977-11-29
Abstract
No abstract record available.
Inventors
- 👤 Richard W Henn
- 👤 David K Bulloch
- 👤 Charleton C Bard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:42
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/50
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
181 words
IN A PHOTOGRAPHIC REVERSAL PROCESS COMPRISING EXPOSING A PHOTOGRAPHIC SILVER HALIDE EMULSION TO AN IMAGE, DEVELOPING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION TO PRODUCE A BLACK-AND-WHITE NEGATIVE IMAGE BY CONTACTING SAID EXPOSED PHOTOGRAPHIC SILVER HALIDE EMULSION WITH A PHOTOGRAPHIC DEVELOPER, AND SUBSEQUENTLY OBTAINING A REVERSAL POSITIVE IMAGE BY CONTACTING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION WITH A NUCLEATING AGENT FOR A SUFFICIENT TIME ONLY TO NUCLEATE PREVIOUSLY UNEXPOSED SILVER HALIDE SUBSTANTIALLY WITHOUT THE FORMATION OF A VISIBLE IMAGE, FOLLOWED BY CONTACTING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION WITH A SECOND PHOTOGRAPHIC DEVELOPER FOR A SUFFICIENT TIME TO DEVELOP A VISIBLE IMAGE, THE STEP OF NUCLEATING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION BY CONTACTING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION WITH AN AQUEOUS SOLUTION OF AN ALKALI METAL BOROHYDRIDE HAVING A PH OF AT LEAST 10.0 AND CONTAINING AT LEAST 0.1 G./LITER OF SOLUTION BUT NOT MORE THAN 30 G./LITER OF SOLUTION OF AN ALKALI METAL BOROHYDRIDE SELECTED FROM THE CLASS CONSISTING OF SODIUM BOROHYDRIDE AND POTASSIUM BOROHYDRIDE FOR A SUFFICIENT TIME ONLY TO NUCLEATE PREVIOUSLY UNEXPOSED SILVER HALIDE SUBSTANTIALLY WITHOUT THE FORMATION OF A VISIBLE IMAGE.
Claim 2
Dependent Claim
181 words
IN A PHOTOGRAPHIC REVERSAL PROCESS COMPRISING EXPOSING A PHOTOGRAPHIC SILVER HALIDE EMULSION TO AN IMAGE, DEVELOPING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION TO PRODUCE A BLACK-AND-WHITE NEGATIVE IMAGE BY CONTACTING SAID EXPOSED PHOTOGRAPHIC SILVER HALIDE EMULSION WITH A PHOTOGRAPHIC DEVELOPER, AND SUBSEQUENTLY OBTAINING A REVERSAL POSITIVE IMAGE BY CONTACTING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION WITH A NUCLEATING AGENT FOR A SUFFICIENT TIME ONLY TO NUCLEATE PREVIOUSLY UNEXPOSED SILVER HALIDE SUBSTANTIALLY WITHOUT THE FORMATION OF A VISIBLE IMAGE, FOLLOWED BY CONTACTING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION WITH A SECOND PHOTOGRAPHIC DEVELOPER FOR A SUFFICIENT TIME TO DEVELOP A VISIBLE IMAGE, THE STEP OF NUCLEATING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION BY CONTACTING SAID PHOTOGRAPHIC SILVER HALIDE EMULSION WITH AN AQUEOUS SOLUTION OF AN ALKALI METAL BOROHYDRIDE HAVING A PH OF AT LEAST 10.0 AND CONTAINING AT LEAST 0.1 G./LITER OF SOLUTION BUT NOT MORE THAN 30 G./LITER OF SOLUTION OF AN ALKALI METAL BOROHYDRIDE SELECTED FROM THE CLASS CONSISTING OF SODIUM BOROHYDRIDE AND POTASSIUM BOROHYDRIDE FOR A SUFFICIENT TIME ONLY TO NUCLEATE PREVIOUSLY UNEXPOSED SILVER HALIDE SUBSTANTIALLY WITHOUT THE FORMATION OF A VISIBLE IMAGE.
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) | 1964-05-15 | 1964-11-14 | 1965-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-05-15 | 1968-11-14 | 1969-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-05-15 | 1972-11-14 | 1973-05-16 | $7700.00 | Window Closed / Lapsed |