US2843481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic processes
Assignee: Polaroid Corp
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Filing: 1954-07-19
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Granted: 1958-07-15
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Expires: 1974-07-19
Abstract
No abstract record available.
Inventors
- 👤 Elkan R Blout
- 👤 Saul G Cohen
- 👤 Green Milton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:00
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/30; G02B5/3025; G02B5/3033; G02B30/00; G02B30/20; G02B30/22; G02B30/25; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/30; G03C5/3014; G03C7/00; G03C7/22; G03C7/25; G03C9/00; G03C9/04
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
70 words
IN A PROCESS OF FORMING A SILVER TRANSFER PRINT BY A DIFFUSION-TRANSFER REVERSAL PROCESS WHEREIN THE LATENT IMAGE IS DEVELOPED BY AN AQUEOUS COMPOSITION COMPRISING A SILVER HALIDE DEVELOPING AGENT, AN ALKALI AND A SILVER HALIDE SOLVENT, AND UNEXPOSED SILVER HALIDE IS TRANSFERRED TO AN IMAGE-RECEIVING LAYER TO FORM A POSITIVE SILVER IMAGE, THE IMPROVEMENT WHICH COMPRISES EFFECTING SAID DEVELOPMENT USING A MONOCYCLIC, N-HYDROXYL HETEROCYCLIC AMINE AS THE DEVELOPING AGENT.
References Cited (Backward Citations)
US1658177A
Cited
US1937844A
Cited
US2030336A
Cited
US2550617A
Cited
US2623880A
Cited
US2648673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-07-14 | 1962-01-13 | 1962-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-07-14 | 1966-01-13 | 1966-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-07-14 | 1970-01-13 | 1970-07-15 | $7700.00 | Window Closed / Lapsed |