US3220837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffusion transfer to stratum of a silver image inked and used in printing
Assignee: Polaroid Corp
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Filing: 1955-07-22
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Granted: 1965-11-30
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Expires: 1975-07-22
Abstract
No abstract record available.
Inventors
- 👤 Edwin H Land
- 👤 Meroe M Morse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:32
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/06; G03F7/07
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
166 words
A PROCESS COMPRISING THE STEPS OF APPLYING TO A PHOTOEXPOSED SILVER HALIDE STRATUM AND A SUPERPOSED HYDROPHILIC, WATER-RECEPTIVE, SILVER-RECEPTIVE STRATUM WHICH CONTAINS NUCLEI FOR PRECIPITATION OF SILVER FROM A WATERSOLUBLE SILVER COMPLEX, AND AQUEOUS ALKALINE SOLUTION OF A SILVER HALIDE DEVELOPER AND A SILVER HALIDE SOLVENT, REDUCING THE EXPOSED SILVER HALIDE IN THE SILVER HALIDE STRATUM TO SILVER, FORMING FROM UNREDUCED SILVER HALIDE IN THE SILVER HALIDE STRATUM A WATER-SOLUBLE SILVER COMPLEX, DIFFUSING THE COMPLEX TO THE SILVER-RECEPTIVE STRATUM, PRODUCING FROM THE COMPLEX IN CONJUNCTION WITH SAID NUCLEI A VISIBLE IMAGE OF THE SILVER-RECEPTIVE STRATUM, SAID IMAGE HAVING FIRST AREAS THAT CONTAIN SILVER CONCENTRATED PRIMARILY AT THE SURFACE OF SAID SILVER-RECEPTIVE STRATUM IN THIN BUT SUBSTANTIALLY CONTINUOUS, OLEOPHILIC DENSE MASSES AND SECOND AREAS THAT ARE SUBSTANTIALLY SILVER-FREE, THEREAFTER STRIPPING THE SILVER HALIDE STRATUM FROM THE SILVER-RECEPTIVE STRATUM, COATING SAID SILVER-RECEPTIVE STRATUM WITH AN INK WHICH WILL PREFERENTIALLY WET SAID FIRST AREAS, AND PRESSING THE IMAGE ONTO A COPY SHEET IN ORDER TO TRANSFER SAID INK THERETO.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-29 | 1969-05-31 | 1969-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-29 | 1973-05-31 | 1973-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-29 | 1977-05-31 | 1977-11-30 | $7700.00 | Window Closed / Lapsed |