US3341330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming thermally stable photochromic images and product
Assignee: Appvion LLC
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Filing: 1964-01-16
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Granted: 1967-09-12
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Expires: 1984-01-16
Abstract
No abstract record available.
Inventors
- 👤 Peter L Foris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:07
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/685; Y; Y10; Y10S; Y10S430/00; Y10S430/163
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
102 words
A METHOD OF RECORDING CONSISTING OF THE STEPS OF: (A) FORMING AN IMAGE ON A LAYER OF PHOTOCHROMIC MATERIAL OF THE SPIRO-PYRAN TYPE BY EXPOSURE OF IT TO ULTRAVIOLET LIGHT IN THE IMAGE-REPRESENTING AREAS, AND KEEPING SUCH IMAGE FROM THERMAL DECAY BY COOLING SAID LAYER; (B) AND LATER SUBJECTING THE RECORD TO ACID VAPORS SELECTED FROM THE GROUP CONSISTING OF HYDROHALIC ACID VAPORS AND SULFUR DIOXIDE VAPORS BEFORE SUBJECTING THE LAYER TO HIGHER TEMPERATURES APT TO CAUSE THERMAL DECAY OF THE IMAGE, SAID IMAGE BEING REVERSIBLE TO ITS STATE IN WHICH IT IS SUBJECT TO THERMAL DECAY BY APPLICATION OF AMMONIA VAPORS.
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) | 1970-09-11 | 1971-03-13 | 1971-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-11 | 1975-03-13 | 1975-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-11 | 1979-03-13 | 1979-09-12 | $7700.00 | Window Closed / Lapsed |