Patent US3650974A successfully refreshed from Google Patents.
US3650974A
Expired / Lapsed
US
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Alkaline earth halosilicate phosphors
Assignee: EMI Group Ltd
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Filing: 1969-05-13
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Granted: 1972-03-21
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Expires: 1989-05-13
Abstract
Abstract A PHOSPHOR FOR USE IN FLUORESCENT LAMPS COMPRISING AN ALAKILNE EARTH YTRIUM OR LANTHANUM HALOSILICATE ACTIVATED BY ACTIVATING METAL IONS IN THE TRIVALENT STATE AND/OR ACTIVITING METAL IONS IN THE DIVALENT STATE, E.G., BY TRIVALENT TIN, ANTIMONY, TERBIUM CERIUM OR EUROPIUM IONS.
Inventors
- 👤 Harold Francis Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:02
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/77062
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) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |