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US3673103A
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Yttrium orthophosphate phosphor
Assignee: Mitsubishi Electric Corp
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Filing: 1969-08-29
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Granted: 1972-06-27
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Expires: 1989-08-29
Abstract
Abstract A phosphor consisting of yttrium phosphate as a matrix and cerium and thorium as an activator, represented by the general formula Y1 x 4/3yCexThyPO4 wherein x is 0.01-0.1 mol and y is 0.0002-0.05 mol. This phosphor gives a particularly strong luminescence in the near UV wavelength zone of 330-370 millimicrons, and has a light output about 1.5 times as high as a lead-activated barium disilicate (BaSi2O5:Pb), the light output decrease during light production being markedly small.
Inventors
- 👤 Kenzo Awazu
- 👤 Kazu Matsunaga
- 👤 Katsutoshi Muto
- 👤 Junjiro Kai
- 👤 Kyoko Oi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:41
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/0855; C09K11/0872; C09K11/77; C09K11/7766; C09K11/7777
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
68 words
A process for the production of the yttrium orthophosphate phosphor represented by the general formula Y1 x 4/3yCexThyPO4, wherein x is 0.01-0.1 and y is 0.0002-0.05, which comprises firing at least one compound selected from the class consisting of ammonium monohydrogen phosphate and phosphoric acid with a member selected from the class consisting of yttrium oxide and yttrium nitrate, cerium nitrate and thorium nitrate in a reducing atmosphere.
Claim 2
Dependent Claim
14 words
The process of claim 2 wherein said oxide is obtained by heating inorganic compounds.
Claim 3
Dependent Claim
26 words
The process of claim 2 wherein said oxide is obtained by heating at least one compound selected from the class consisting oF nitrates, acetates and oxalates.
Claim 4
Dependent Claim
17 words
The process of claim 2, wherein said firing is carried out at a temperature of 1,200*-1,300* C.
Claim 5
Dependent Claim
84 words
A process for the production of the yttrium orthophosphate phosphor represented by the general formula, Y1 x 4/3yCexThyPO4 wherein x is 0.01-0.1 and y is 0.0002- 0.05, which comprises adding a compound selected from the class consisting of ammonium monohydrogen phosphate and phosphoric acid to an aqueous solution containing thorium nitrate, a member selected from the class consisting of yttrium oxide and yttrium nitrate, and cerium nitrate, reacting to form a precipitate, drying said precipitate and then firing said precipitate in a reducing atmosphere.
Claim 6
Dependent Claim
17 words
The process of claim 6 wherein said firing is carried out at a temperature of 1,200*-1,300* C.
References Cited (Backward Citations)
US3351436A
Cited
US3314893A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |