US3887725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for improving lumen maintenance of calcium halophosphate phosphors used in a fluorescent lamp
Assignee: GTE Sylvania Inc
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Filing: 1972-12-04
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Granted: 1975-06-03
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Expires: 1992-12-04
Abstract
Abstract Addition of zinc orthophosphate to a calcium halophosphatelacquer slurry before application to a fluorescent lamp tube increases the lumen maintenance thereof. The additive quantity is in the range of from 0.06 to 0.60 percent by weight of the halophosphate phosphor.
Inventors
- 👤 Jr Albert O Halstead
- 👤 Donald A Hebbard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:23
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/74; C09K11/75; C09K11/76; H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/44
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
81 words
IN A PROCESS OF FABRICATING A FLUORESCENT LAMP IN WHICH A SLURRY OF A CALCIUM HALOPHOSPHATE PHOSPHOR HAVING THE GENERAL FORMULA CA10(F,CL)2(PO4)6:MN, SB AND A SUITABLE LACQUER IS APPLIED TO THE INTERIOR SURFACE OF SAID LAMP AND BAKED, THE IMPROVEMENT WHEREIN PRIOR TO THE APPLICATION OF SAID SLURRY TO SAID SURFACE, AN AMOUNT OF ZINC ORTHOPHOSPHATE SUFFICIENT TO INCREASE LUMEN MAINTENANCE OF SAID PHOSPHOR IS ADDED TO SAID SLURRY AND THE RESULTANT SLURRY IS BLENDED TO FORM A SUBSTANTIALLY HOMOGENOUS MIXTURE.
Claim 2
Dependent Claim
81 words
IN A PROCESS OF FABRICATING A FLUORESCENT LAMP IN WHICH A SLURRY OF A CALCIUM HALOPHOSPHATE PHOSPHOR HAVING THE GENERAL FORMULA CA10(F,CL)2(PO4)6:MN, SB AND A SUITABLE LACQUER IS APPLIED TO THE INTERIOR SURFACE OF SAID LAMP AND BAKED, THE IMPROVEMENT WHEREIN PRIOR TO THE APPLICATION OF SAID SLURRY TO SAID SURFACE, AN AMOUNT OF ZINC ORTHOPHOSPHATE SUFFICIENT TO INCREASE LUMEN MAINTENANCE OF SAID PHOSPHOR IS ADDED TO SAID SLURRY AND THE RESULTANT SLURRY IS BLENDED TO FORM A SUBSTANTIALLY HOMOGENOUS MIXTURE.
Claim 3
Dependent Claim
80 words
In a process of fabricating a fluorescent lamp in which a slurry of a calcium halophosphate phosphor having the general formula Ca10(F,Cl)2(PO4)6:Mn,Sb and a suitable lacquer is applied to the interior surface of said lamp and baked, the improvement wherein prior to the application of said slurry to said surface, an amount of zinc orthophosphate sufficient to increase lumen maintenance of said phosphor is added to said slurry and the resultant slurry is blended to form a substantially homogenous mixture.
Claim 4
Dependent Claim
80 words
In a process of fabricating a fluorescent lamp in which a slurry of a calcium halophosphate phosphor having the general formula Ca10(F,Cl)2(PO4)6:Mn,Sb and a suitable lacquer is applied to the interior surface of said lamp and baked, the improvement wherein prior to the application of said slurry to said surface, an amount of zinc orthophosphate sufficient to increase lumen maintenance of said phosphor is added to said slurry and the resultant slurry is blended to form a substantially homogenous mixture.
References Cited (Backward Citations)
US3430089A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |