Patent US6193714B1 successfully refreshed from Google Patents.
US3121632A
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US
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Photographic process and composition including leuco triphenylmethane dyes
Assignee: Horizons Inc
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Filing: 1961-08-30
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Granted: 1964-02-18
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Expires: 1981-08-30
Abstract
No abstract record available.
Inventors
- 👤 Robert H Sprague
- 👤 John A Stewart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:38
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/73; G03C1/732
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
19 words
A METHOD OF INCREASING THE PHOTOSENSITIVITY TO ULTRAVIOLET OF LEUCO BASES OF TRIPHENYLMETHANE DYES REPRESENTED BY THE GENERAL FORMULA
References Cited (Backward Citations)
GB190404994A
Cited
US1782259A
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US2324060A
Cited
US2366179A
Cited
US2441561A
Cited
US2528496A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-02-17 | 1967-08-19 | 1968-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-02-17 | 1971-08-19 | 1972-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-02-17 | 1975-08-19 | 1976-02-18 | $7700.00 | Window Closed / Lapsed |