US2506622A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elimination of preservative sulfite from photographic developers prior to use in color development
Assignee: Technicolor Motion Picture Corp
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Filing: 1945-03-08
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Granted: 1950-05-09
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Expires: 1965-03-08
Abstract
No abstract record available.
Inventors
- 👤 Tull Alan Gilbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:06
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/407; G03C7/413; G03C5/00; G03C5/26; G03C5/29; G03C5/305
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
IN A PROCESS OF PHOTOGRAPHIC DEVELOPMENT OF A SILVER SALT IN WHICH IN ADDITION TO THE SILVER IMAGE THERE IS ALSO PRODUCED A SECONDARY IMAGE DERIVED FROM THE OXIDATION PRODUCTS OF THE DEVELOPING AGENT, AND FOR WHICH DEVELOPMENT THERE IS EMPLOYED AN AQUEOUS SOLUTION OF A DEVELOPING AGENT WHICH PRIOR TO USE CONTAINS A SULPHITE AS PRESERVATIVE, THE STEP OF INHIBITING THE EFFECT OF SAID SULPHITE DURING DEVELOPMENT PROPER, BY ADDING TO SAID SOLUTION IMMEDIATELY BEFORE ANY SUBSTANTIAL DEVELOPMENT HAS BEGUN A WATER SOLUBLE COMPOUND OF AN ALKALINE EARTH METAL CAPABLE OF PRECIPITATING SAID SULPHITE, IN AN AMOUNT SUFFICIENT TO BIND SUBSTANTIALLY THE WHOLE OF SAID SULPHITE TO FORM A COMPOUND WHICH IS INNOCUOUS TO SAID DEVELOPMENT.
Claim 2
Dependent Claim
117 words
IN A PROCESS OF PHOTOGRAPHIC DEVELOPMENT OF A SILVER SALT IN WHICH IN ADDITION TO THE SILVER IMAGE THERE IS ALSO PRODUCED A SECONDARY IMAGE DERIVED FROM THE OXIDATION PRODUCTS OF THE DEVELOPING AGENT, AND FOR WHICH DEVELOPMENT THERE IS EMPLOYED AN AQUEOUS SOLUTION OF A DEVELOPING AGENT WHICH PRIOR TO USE CONTAINS A SULPHITE AS PRESERVATIVE, THE STEP OF INHIBITING THE EFFECT OF SAID SULPHITE DURING DEVELOPMENT PROPER, BY ADDING TO SAID SOLUTION IMMEDIATELY BEFORE ANY SUBSTANTIAL DEVELOPMENT HAS BEGUN A WATER SOLUBLE COMPOUND OF AN ALKALINE EARTH METAL CAPABLE OF PRECIPITATING SAID SULPHITE, IN AN AMOUNT SUFFICIENT TO BIND SUBSTANTIALLY THE WHOLE OF SAID SULPHITE TO FORM A COMPOUND WHICH IS INNOCUOUS TO SAID DEVELOPMENT.
References Cited (Backward Citations)
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Cited
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GB454794A
Cited
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Cited
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Cited
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Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-05-08 | 1953-11-07 | 1954-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-05-08 | 1957-11-07 | 1958-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-05-08 | 1961-11-07 | 1962-05-09 | $7700.00 | Window Closed / Lapsed |