Patent US2423767A successfully refreshed from Google Patents.
US2423767A
Expired / Lapsed
US
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Tone-control agents for silver halide emulsions
Assignee: Ilford Imaging UK Ltd
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Filing: 1944-12-13
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Granted: 1947-07-08
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Expires: 1964-12-13
Abstract
No abstract record available.
Inventors
- 👤 Fry Douglas James
- 👤 Brooks James Douglas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:48
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/35; G03C5/00; G03C5/26; G03C5/29; G03C5/305; Y; Y10; Y10S; Y10S430/00; Y10S430/162; Y10S430/166
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US394290A
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US1623499A
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US2124159A
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US2266442A
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US2286662A
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US2276254A
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US2309492A
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US2298093A
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US2346065A
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US2311098A
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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) | 1950-07-07 | 1951-01-06 | 1951-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-07-07 | 1955-01-06 | 1955-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-07-07 | 1959-01-06 | 1959-07-08 | $7700.00 | Window Closed / Lapsed |