US4052329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing cerium-activated yttrium silicate phosphor
Assignee: Panasonic Holdings Corp
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Filing: 1976-06-07
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Granted: 1977-10-04
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Expires: 1996-06-07
Abstract
Abstract In the firing of a cerium-activated Y 2 O 3 -SiO 2 system phosphor such as Y 2 SiO 5 :Ce and Y 2 Si 2 O 7 :Ce, the improvement of adding BaF 2 in a mol ratio of BaF 2 /Y 2 O 3 of 0.01-0.1 is disclosed which increases the luminosity, emission intensity or both of the phosphor. Phosphors having improved properties are conveniently prepared according to the disclosed process.
Inventors
- 👤 Yoji Fukuda
- 👤 Fumio Fukushima
- 👤 Yoshinobu Tsujimoto
- 👤 Masakazu Fukai
- 👤 Shinji Sugai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:37
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7767; C09K11/7769; C09K11/77742
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
124 words
A method of increasing the emission intensity of a Y 2 SiO 5 :Ce phosphor at around the 450nm wavelength comprising adding BaF 2 to a mixture of Y 2 O 3 , SiO 2 and CeO 2 , wherein the BaF 2 is added in an amount such that the BaF 2 /Y 2 O 3 mol ratio is 0.01 to 0.2 inclusive and wherein the SiO 2 /Y 2 O 3 mol ratio is 1.0 to 1.2 inclusive, and thereafter firing the BaF 2 -containing mixture at a temperature of the order of 1200-1500° C in air or a reducing atmosphere of an inert gas containing up to 5% hydrogen to produce a cerium-activated phosphate phosphor exhibiting increased luminosity and emission intensity.
Claim 2
Independent Claim
124 words
A method of increasing the emission intensity of a Y 2 SiO 5 :Ce phosphor at around the 450nm wavelength comprising adding BaF 2 to a mixture of Y 2 O 3 , SiO 2 and CeO 2 , wherein the BaF 2 is added in an amount such that the BaF 2 /Y 2 O 3 mol ratio is 0.01 to 0.2 inclusive and wherein the SiO 2 /Y 2 O 3 mol ratio is 1.0 to 1.2 inclusive, and thereafter firing the BaF 2 -containing mixture at a temperature of the order of 1200-1500° C in air or a reducing atmosphere of an inert gas containing up to 5% hydrogen to produce a cerium-activated phosphate phosphor exhibiting increased luminosity and emission intensity.
Claim 3
Dependent Claim
31 words
The method of claim 1 wherein the amount of BaF 2 added to the mixture is such that the ratio of BaF 2 /Y 2 O 3 is 0.03 to 0.1.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the amount of BaF 2 added to the mixture is such that the ratio of BaF 2 /Y 2 O 3 is 0.05 to 0.07.
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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |