US5124072A
Expired / Lapsed
US
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Alkaline earth hafnate phosphor with cerium luminescence
Assignee: General Electric Co
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Filing: 1991-12-02
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Granted: 1992-06-23
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Expires: 2011-12-02
Abstract
Abstract A phosphor comprising an effective amount of cerium to provide luminescence, and the balance substantially an oxide compound of hafnium and an alkaline earth from the group consisting of barium, strontium, calcium, and mixtures thereof, having substantially a perovskite crystal form.
Inventors
- 👤 Stephen L. Dole
- 👤 Subramaniam Venkataramani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:31
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7715; C09K11/7716; C09K11/7718
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
78 words
An alkaline earth hafnate phosphor with cerium luminescence having substantially a perovskite crystal form comprising about 0.01 to 10 mole percent cerium, and the balance substantially an oxide having the formula AHfO 3 , where A is an alkaline earth from the group consisting of barium, strontium, calcium, and mixtures thereof, wherein the ratio of Hf:A is about 1:095 to 1.05, and exhibiting a decay time constant that is about an order of magnitude less than 300 nanoseconds.
Claim 2
Dependent Claim
78 words
An alkaline earth hafnate phosphor with cerium luminescence having substantially a perovskite crystal form comprising about 0.01 to 10 mole percent cerium, and the balance substantially an oxide having the formula AHfO 3 , where A is an alkaline earth from the group consisting of barium, strontium, calcium, and mixtures thereof, wherein the ratio of Hf:A is about 1:095 to 1.05, and exhibiting a decay time constant that is about an order of magnitude less than 300 nanoseconds.
Claim 3
Dependent Claim
16 words
A phosphor according to claim 1 wherein the cerium is about 0.1 to 1 mole percent.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-23 | 1995-12-23 | 1996-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-23 | 1999-12-23 | 2000-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-23 | 2003-12-23 | 2004-06-23 | $7700.00 | Window Closed / Lapsed |