Patent US3690889A successfully refreshed from Google Patents.
US3690889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photocolorable vacuum sublimed xanthene dye
Assignee: RCA Corp
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Filing: 1970-09-30
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Granted: 1972-09-12
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Expires: 1990-09-30
Abstract
Abstract AN OPTICAL RECORDING AND STORAGE MEDIA COMPRISES A SUBSTRATE HAVING AN ESSENTIALLY COLORLESS VACCUM SUBLIMED XANTHENE DYE TYPE FILM THEREON. THE XANTHENE DYE IS OF THE TYPE HAVING A PENDANT PHENYL RING AT THE 9TH CARBON OF THE XANTHENE STRUCTURE. A COOH GROUP IS PRESENT ON THE CARBON ATOM OF THE PHENYL RING IMMEDIATELY ADJACENT THE LINKING CARBON OF THE RING. ELECTRON WITHDRAWING GROUPS ARE PRESENT ON THE XANTHENE STRUCTURE. AN EXAMPLE OF SUCH A MATERIAL IS RHODAMINE B.
Inventors
- 👤 Sol Esther Harrison
- 👤 Robert Drake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:03
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/73
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |