US3597082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Uncopyable photochromic paper
Assignee: Western Atlas Inc
•
Filing: 1967-02-20
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Granted: 1971-08-03
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Expires: 1987-02-20
Abstract
Abstract A photochromic paper having visible data thereon which, in response to radiation impinging on its surface, temporarily changes color to substantially match the color of the data thereby preventing copying therefrom.
Inventors
- 👤 Raymond W James
- 👤 Wyman F Uhl
- 👤 Christo Antonio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:07
CPC Classifications
G; G03; G03G; G03G21/00; G03G21/04; G03G21/043; G03B; G03B15/00; G03C; G03C5/00; G03C5/08; Y; Y10; Y10S; Y10S283/00; Y10S283/902
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
27 words
A support including a photochromic layer, visible data on said photochromic layer having a color substantially matching the color of the excited form of said photochromic layer.
Claim 2
Dependent Claim
27 words
A support including a photochromic layer, visible data on said photochromic layer having a color substantially matching the color of the excited form of said photochromic layer.
Claim 3
Dependent Claim
24 words
A support as defined by claim 1, wherein said photochromic layer comprises a sheet of paper, photochromic material incorporated into said sheet of paper.
Claim 4
Dependent Claim
23 words
A support as defined by claim 2, wherein there is at least 1 pound of photochromic material per 3,000 square feet of paper.
Claim 5
Dependent Claim
39 words
A support as defined by claim 1, wherein said photochromic layer comprises a photochromic coating on said support, said coating comprising a compatible resin binder and from about 10 percent to 90 percent by weight of a photochromic material.
Claim 6
Dependent Claim
31 words
A support as defined by claim 1, wherein said photochromic layer includes photochromes selected from the group consisting of phosphotungstic acid, silicotungstic acid, benzyldthydraphenol hydrazine, copper chloride, spiropyrans, bilophenes and triarylmethaneleucocyanides.
References Cited (Backward Citations)
US2740324A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |