Patent US3004850A successfully refreshed from Google Patents.
US3004850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of positive photographic records
Assignee: Ilford Imaging UK Ltd
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Filing: 1959-11-23
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Granted: 1961-10-17
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Expires: 1979-11-23
Abstract
No abstract record available.
Inventors
- 👤 Dickinson Harold Owen
- 👤 Duffin George Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:42
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/24; G03C8/243; C; C07; C07D; C07D231/00; C07D231/02; C07D231/10; C07D231/14; C07D231/18; C07D231/20; C07D231/54; Y; Y10; Y10S; Y10S430/00; Y10S430/166
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
60 words
A METHOD FOR PRODUCTION OF PHOTOGRAPHIC RECORDS FROM SILVER HALIDE PHOTOGRAPHIC EMULSIONS BY THE DIFFUSION TRANSFER PROCESS WHICH COMPRISES DEVELOPING A PHOTOGRAPHIC SILVER HALIDE EMULSION LAYER WHILE THE EMULSION LAYER IS IN FACE CONTACT WITH A LAYER CONTAINING DEVELOPMENT NUCLEI, THE DEVELOPMENT BEING EFFECTED IN THE PRESENCE OF A SOLVENT FOR SILVER HALIDE AND A COMPOUND OF THE GENERAL FORMULA:
Claim 2
Independent Claim
60 words
A METHOD FOR PRODUCTION OF PHOTOGRAPHIC RECORDS FROM SILVER HALIDE PHOTOGRAPHIC EMULSIONS BY THE DIFFUSION TRANSFER PROCESS WHICH COMPRISES DEVELOPING A PHOTOGRAPHIC SILVER HALIDE EMULSION LAYER WHILE THE EMULSION LAYER IS IN FACE CONTACT WITH A LAYER CONTAINING DEVELOPMENT NUCLEI, THE DEVELOPMENT BEING EFFECTED IN THE PRESENCE OF A SOLVENT FOR SILVER HALIDE AND A COMPOUND OF THE GENERAL FORMULA:
References Cited (Backward Citations)
US2699393A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-10-16 | 1965-04-17 | 1965-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-10-16 | 1969-04-17 | 1969-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-10-16 | 1973-04-17 | 1973-10-17 | $7700.00 | Window Closed / Lapsed |