US4479886A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making cerium activated yttrium aluminate phosphor
Assignee: Osram Sylvania Inc
•
Filing: 1983-08-08
•
Granted: 1984-10-30
•
Expires: 2003-08-08
Abstract
Abstract The luminous efficiency of Y 3 Al 5 O 12 :Ce phosphor can be increased by milling the phosphor to reduce its particle size, blending barium fluoride into the milled phosphor, and then reduction annealing the blend of phosphor and barium fluoride.
Inventors
- 👤 Anthony F. Kasenga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:29
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7774
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
155 words
The method of making Y 3 Al 5 O 12 :Ce phosphor comprising the steps of forming a mixture of source materials for Y 3 Al 5 O 12 :Ce phosphor; firing the mixture at an elevated temperature to react the source materials to form Y 3 Al 5 O 12 :Ce phosphor; milling the phosphor to reduce the particle size thereof; blending barium fluoride into the milled phosphor; and annealing the blend of milled phosphor and barium fluoride in a reducing atmosphere at a high temperature lower than said elevated temperature, the amount of barium fluoride blended into the milled phosphor being such that the Y 3 Al 5 O 12 :Ce phosphor so made exhibits a greater brightness at 3650 excitation than said phosphor prepared as above absent the steps of milling the phosphor, blending barium fluoride into the milled phosphor and annealing the blend in a reducing atmosphere at said high temperature.
Claim 2
Independent Claim
155 words
The method of making Y 3 Al 5 O 12 :Ce phosphor comprising the steps of forming a mixture of source materials for Y 3 Al 5 O 12 :Ce phosphor; firing the mixture at an elevated temperature to react the source materials to form Y 3 Al 5 O 12 :Ce phosphor; milling the phosphor to reduce the particle size thereof; blending barium fluoride into the milled phosphor; and annealing the blend of milled phosphor and barium fluoride in a reducing atmosphere at a high temperature lower than said elevated temperature, the amount of barium fluoride blended into the milled phosphor being such that the Y 3 Al 5 O 12 :Ce phosphor so made exhibits a greater brightness at 3650 excitation than said phosphor prepared as above absent the steps of milling the phosphor, blending barium fluoride into the milled phosphor and annealing the blend in a reducing atmosphere at said high temperature.
References Cited (Backward Citations)
US4070301A
Cited
US4141855A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-30 | 1988-04-30 | 1988-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-30 | 1992-04-30 | 1992-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-30 | 1996-04-30 | 1996-10-30 | $7700.00 | Window Closed / Lapsed |