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US4451757A
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Fluorescent lamp having improved maintenance
Assignee: Osram Sylvania Inc
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Filing: 1982-01-25
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Granted: 1984-05-29
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Expires: 2002-01-25
Abstract
Abstract Lumen maintenance of fluorescent lamps is improved by dispersing throughout the phosphor a small quantity, less than 0.2% by weight of the phosphor, of a metallic borate. The improvement is realized in lamps with or without an internal conductive coating.
Inventors
- 👤 Costas C. Lagos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:19
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/46
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
114 words
A fluorescent lamp comprised of a tubular glass envelope having electrodes sealed in the ends thereof and having in its interior a luminescent material of a given weight, said luminescent material including a substantially homogeneous dispersion of a metallic borate in an amount effective to increase the lumen maintenance of said lamp, said borate having the general formula MB.sub.x O.sub.y ZH.sub.2 O where M=Na; Ba; Zn; or Ca; and when M=Na, then x=4, y=7, and Z=10; when M=Ba, then x=2, y=4, and Z=1; when M=Zn, then x=4, y=9, and Z=5; when M=Ca, then x=4, y=7, and Z=0; and wherein said borate comprises from about 0.02 to about 0.12% by weight of said luminescent material.
Claim 2
Dependent Claim
114 words
A fluorescent lamp comprised of a tubular glass envelope having electrodes sealed in the ends thereof and having in its interior a luminescent material of a given weight, said luminescent material including a substantially homogeneous dispersion of a metallic borate in an amount effective to increase the lumen maintenance of said lamp, said borate having the general formula MB.sub.x O.sub.y ZH.sub.2 O where M=Na; Ba; Zn; or Ca; and when M=Na, then x=4, y=7, and Z=10; when M=Ba, then x=2, y=4, and Z=1; when M=Zn, then x=4, y=9, and Z=5; when M=Ca, then x=4, y=7, and Z=0; and wherein said borate comprises from about 0.02 to about 0.12% by weight of said luminescent material.
Claim 3
Dependent Claim
54 words
The lamp of claim 1 wherein said tubular glass envalope has a transparent conductive coating on the interior surface thereof; said luminescent material overlies said conductive coating and said borate comprises Na 2 B 4 O 7 .10H 2 O in an amount of about 0.02 to 0.05% by weight of said luminescent material.
Claim 4
Dependent Claim
44 words
The lamp of claim 1 wherein said luminescent material is applied to the interior surface of said glass envelope and said borate comprises BaB 2 O 4 .H 2 O in an amount of about 0.03 to 0.07% by weight of said luminescent material.
Claim 5
Dependent Claim
72 words
A luminescent material including a substantially homogeneous dispersion of a metallic borate having the general formula MB.sub.x O.sub.y ZH.sub.2 O where M=Na; Ba; Zn; or Ca; and when M=Na; then x=4, y=7, and Z=10; when M=Ba; then x=2, y=4, and Z=1; when M=Zn, then x=4, y=9, and Z=5; when M=Ca, then x=4, y=7, and Z=0; and wherein said borate comprises from about 0.02 to about 0.12% by weight of said luminescent material.
Claim 6
Dependent Claim
72 words
A luminescent material including a substantially homogeneous dispersion of a metallic borate having the general formula MB.sub.x O.sub.y ZH.sub.2 O where M=Na; Ba; Zn; or Ca; and when M=Na; then x=4, y=7, and Z=10; when M=Ba; then x=2, y=4, and Z=1; when M=Zn, then x=4, y=9, and Z=5; when M=Ca, then x=4, y=7, and Z=0; and wherein said borate comprises from about 0.02 to about 0.12% by weight of said luminescent material.
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) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |