Patent US3567442A successfully refreshed from Google Patents.
US3567442A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Novel photographic products and processes
Assignee: Polaroid Corp
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Filing: 1967-03-10
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Granted: 1971-03-02
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Expires: 1987-03-10
Abstract
Abstract THE PRESENT INVENTION IS DIRECTED TO A SILVER DIFFUSION TRANSFER PHOTOGRAPHIC PROCESS PRINT-RECEIVING ELEMENT WHICH COMPRISES A COMMON SUPPORT CARRYING ON ONE SURFACE A PLURALITY OF LAYERS EACH OF WHICH COMPRISES METALLIC SULFIDE, METALLIC SELENIDE, COLLODIAL METAL, THIOOXALATE OR THIOACETAMIDE SILVER PRECIPITATING AGENTS DISPOSED IN A GELATIN, DEACTYLATED CHITIN OR SILICA MATRIX WHEREIN EACH SUCH LAYER COMPRISES A SUBSTANTIALLY CONSTANT CONCENTRATION OF SILVER PRECIPITATING AGENT PER UNIT AREA, AND A DECREASING CONCENTRATION, LAYER-WISE, IN THE DIRECTION OF THE SUPPORT; AND TO PHOTOGRAPHIC SILVER DIFFUSION TRANSFER PROCESSES EMPLOYING SUCH PRINT RECEIVING ELEMENT.
Inventors
- 👤 Edwin Land
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:26
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/24; G03C8/26; G03C8/28
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |