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US4070301A
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Method of preparing cerium-activated yttriumaluminate phosphor of improved efficiency
Assignee: Panasonic Holdings Corp
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Filing: 1976-06-01
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Granted: 1978-01-24
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Expires: 1996-06-01
Abstract
Abstract A cerium-activated yttriumaluminate phosphor such as YA103:Ce featuring an enhanced luminous intensity is produced by adding a barium compound exemplified by BaO, BaCO3, Ba(OH)2 and BaF3 to a mixture of source materials of the host material and the activator and baking the resulting mixture at a usual temperature ranging from 1000 DEG to 1400 DEG C. The barium compound preferably amounts to 0.001-8 mol% of the yttriumaluminate and may alternatively be introduced into a preliminarily baked and pulverized mixture of the source materials.
Inventors
- 👤 Tetsuhiko Tomiki
- 👤 Takeshi Takeda
- 👤 Takeo Miyata
- 👤 Fumio Muramatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:22
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7774
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
194 words
A method of producing a phosphor comprising yttrium aluminate activated by cerium, the atomic ratio of yttrium to aluminum in the phosphor being substantially 1:1, the method comprising the steps of: a. preparing a mixture of Y 2 O 3 , Al 2 O 3 and CeF 3 , the molar ratio of Y 2 O 3 to Al 2 O 3 being substantially 1:1, the quantity of CeF 3 being such that cerium amounts to 0.1 to 5 mol % of said yttrium aluminate; b. adding a barium compound selected from the group consisting of BaO, BaCO 3 , BaF 2 , BaCl 2 and barium salts which yield BaO at a temperature below 1400° C. and selected from the group consisting of Ba(NO 3 ) 2 , Ba(OH) 2 and BaC 2 O 4 , to said mixture in an amount of 0.001 to 20 mol % of said mixture; c. baking the resultant mixture at a temperature in the range from about 1000° to about 1400° C.; and d. washing the product of step (c) with nitric acid when said amount of said barium compound is larger than 8 mol %.
Claim 2
Independent Claim
194 words
A method of producing a phosphor comprising yttrium aluminate activated by cerium, the atomic ratio of yttrium to aluminum in the phosphor being substantially 1:1, the method comprising the steps of: a. preparing a mixture of Y 2 O 3 , Al 2 O 3 and CeF 3 , the molar ratio of Y 2 O 3 to Al 2 O 3 being substantially 1:1, the quantity of CeF 3 being such that cerium amounts to 0.1 to 5 mol % of said yttrium aluminate; b. adding a barium compound selected from the group consisting of BaO, BaCO 3 , BaF 2 , BaCl 2 and barium salts which yield BaO at a temperature below 1400° C. and selected from the group consisting of Ba(NO 3 ) 2 , Ba(OH) 2 and BaC 2 O 4 , to said mixture in an amount of 0.001 to 20 mol % of said mixture; c. baking the resultant mixture at a temperature in the range from about 1000° to about 1400° C.; and d. washing the product of step (c) with nitric acid when said amount of said barium compound is larger than 8 mol %.
Claim 3
Dependent Claim
27 words
A method as claimed in claim 1, wherein step (c) is carried out at a temperature in the range of from about 1150° to about 1400° C.
Claim 4
Dependent Claim
34 words
A method as claimed in claim 2 further comprising the step of baking said mixture prepared at step (a) at a temperature below 1150° and then pulverizing the baked mixture prior to step (b).
Claim 5
Independent Claim
170 words
A method of producing a phosphor comprising yttrium aluminate activated by cerium, the atomic ratio of yttrium to aluminum in the phosphor being substantially 1:1, the method comprising the steps of: a. preparing a mixture of Y 2O 3 , Al 2 O 3 and CeF 3 , the molar ratio of Y 2 O 3 to Al 2 O 3 being substantially 1:1, the quantity of CeF 3 being such that cerium amounts to 0.1 to 5 mol % of said yttrium aluminate; b. adding a barium compound selected from the group consisting of BaO, BaCO 3 , BaF 2 , BaCl 2 and barium salts which yield BaO at a temperature below 1400° C. and selected from the group consisting of Ba(NO 3 ) 2 , Ba(OH) 2 and BaC 2 O 4 , to said mixture in an amount of 0.001 to 8 mol % of said mixture; and c. baking the resultant mixture at a temperature in the range from about 1000° to about 1400° C.
Claim 6
Independent Claim
170 words
A method of producing a phosphor comprising yttrium aluminate activated by cerium, the atomic ratio of yttrium to aluminum in the phosphor being substantially 1:1, the method comprising the steps of: a. preparing a mixture of Y 2O 3 , Al 2 O 3 and CeF 3 , the molar ratio of Y 2 O 3 to Al 2 O 3 being substantially 1:1, the quantity of CeF 3 being such that cerium amounts to 0.1 to 5 mol % of said yttrium aluminate; b. adding a barium compound selected from the group consisting of BaO, BaCO 3 , BaF 2 , BaCl 2 and barium salts which yield BaO at a temperature below 1400° C. and selected from the group consisting of Ba(NO 3 ) 2 , Ba(OH) 2 and BaC 2 O 4 , to said mixture in an amount of 0.001 to 8 mol % of said mixture; and c. baking the resultant mixture at a temperature in the range from about 1000° to about 1400° C.
Claim 7
Dependent Claim
27 words
A method as claimed in claim 4, wherein step (c) is carried out at a temperature in the range of from about 1150° to about 1400° C.
Claim 8
Dependent Claim
34 words
A method as claimed in claim 4 further comprising the step of baking said mixture prepared at step (a) at a temperature below 1150° and the pulverizing the baked mixture prior to step (b).
Claim 9
Dependent Claim
22 words
A method as claimed in claim 4, wherein said barium compound is in the range of about 0.05 to 3 mol %.
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) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |