US3761942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low energy thermochromic image recording device
Assignee: International Business Machines Corp
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Filing: 1971-07-28
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Granted: 1973-09-25
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Expires: 1991-07-28
Abstract
Abstract A thermochromic recording device is prepared from reversible photochromic materials. The photochromic material, dissolved in a plastic matrix, is coated onto a substrate. The coating is exposed to light radiation to produce a color therein. The colored layer or film can be rapidly written upon with low energy lasers or light emitting diodes to effect a visible image. Spots having 3 Mu diameters can be recorded with energies as low as 0.043 nanojoules/ Mu 2.
Inventors
- 👤 M Lorenz
- 👤 R Srinivasan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:04
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/73; B; B41; B41M; B41M5/00; B41M5/26; B41M5/28; B41M5/282; B41M5/284; Y; Y10; Y10S; Y10S430/00; Y10S430/146; Y10S430/163
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
152 words
A low energy image recording device comprising a. a substrate; b. an active film comprising a photochromic material dissolved in a plastic matrix, said film being disposed on said substrate, said material being one which becomes colored upon its exposure to a light source and which is changed from its colored to its decolored state upon its exposure in its colored state to a low energy radiation source, said material being selected from the group consisting of 1,3,3 trimethylindolino benzospiropyran and its 5-OCH3, 5-OCH3-6''Cl, 5-OCH3-6Br, 6''-NO2, 5-OCH3-6''NO2, 8''-NO2 and 5, 5''-Cl2-6''-NO2 derivatives, 1, 3,3 trimethylindolino naphthospiropyran and its derivatives, and dianthrone, dixanthylene, xanthylideneanthrone and their derivatives; c. a light source for effecting the coloration of said film; and d. a laser radiation source having a power output not exceeding 1 m watt for inscribing information on said active film by selectively decolorizing said film in its colored state in a predetermined pattern.
Claim 2
Dependent Claim
41 words
A low energy image recording device as defined in claim 16 and further including: e. a metal film interposed between said substrate and said active film for absorbing radiation and transferrng said absorbed radiation as heat energy to said active film.
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) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |