Patent US4243909A successfully refreshed from Google Patents.
US4243909A
Expired / Lapsed
US
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Fluorescent lamp alkaline earth halophosphate phosphor with protective NaCs2 PrCl6 coating
Assignee: Osram Sylvania Inc
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Filing: 1979-01-05
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Granted: 1981-01-06
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Expires: 1999-01-05
Abstract
Abstract Improved fluorescent lamps utilize phosphors which comprise a major amount of a particulate phosphor such as a cool white alkaline earth halophosphate coated with a minor amount of a protective coating consisting of NaCs 2 PrCl 6 .
Inventors
- 👤 Charles Brecher
- 👤 Daniel W. Oblas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:39
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/70; C09K11/72; C09K11/73; C09K11/02; C09K11/025; H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/44
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
115 words
A fluorescent lamp comprising: a tubular envelope; a phosphor layer on the interior surface of said envelope, said layer consisting essentially of finely-divided phosphor particles of a cool white alkaline earth halophosphate phosphor, each particle having a thin protective coating consisting of NaCs 2 PrCl 6 of about 10 Angstroms thickness; said protective coating being essentially opaque to ultraviolet radiation of wavelengths less than about 250 nanometers but excited thereby to emit visible radiation; mercury vapor within said envelope; and a pair of electrodes spaced apart within said tubular envelope and being adapted for connection, at those portions thereof extending outside of said envelope, to means for producing an electric discharge within said tubular envelope.
Claim 2
Dependent Claim
115 words
A fluorescent lamp comprising: a tubular envelope; a phosphor layer on the interior surface of said envelope, said layer consisting essentially of finely-divided phosphor particles of a cool white alkaline earth halophosphate phosphor, each particle having a thin protective coating consisting of NaCs 2 PrCl 6 of about 10 Angstroms thickness; said protective coating being essentially opaque to ultraviolet radiation of wavelengths less than about 250 nanometers but excited thereby to emit visible radiation; mercury vapor within said envelope; and a pair of electrodes spaced apart within said tubular envelope and being adapted for connection, at those portions thereof extending outside of said envelope, to means for producing an electric discharge within said tubular envelope.
References Cited (Backward Citations)
US2920003A
Cited
US3740250A
Cited
US3664862A
Cited
US3890522A
Cited
US4128674A
Cited
US4070598A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |