US5378398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating europium activated strontium tetraborate phosphor
Assignee: Osram Sylvania Inc
•
Filing: 1991-07-15
•
Granted: 1995-01-03
•
Expires: 2011-07-15
Abstract
Abstract Europium activated strontium tetraborate phosphor is reacted with strontium carbonate or strontium fluoride or ammonium fluoride in order to improve emission characteristics.
Inventors
- 👤 Anthony F. Kasenga
- 👤 Joseph J. Lenox
- 👤 John S. Tulk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:48
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7728; C09K11/774
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
38 words
The method of treating europium activated strontium tetraborate phosphor comprising the steps of blending the phosphor with strontium carbonate or strontium fluoride or ammonium fluoride, and then firing the blend at an elevated temperature in a reducing atmosphere.
Claim 2
Independent Claim
38 words
The method of treating europium activated strontium tetraborate phosphor comprising the steps of blending the phosphor with strontium carbonate or strontium fluoride or ammonium fluoride, and then firing the blend at an elevated temperature in a reducing atmosphere.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein the elevated temperature is about 1500° to 1800° F.
Claim 4
Dependent Claim
11 words
The method of claim 1 wherein the reducing atmosphere is hydrogen-nitrogen.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein the phosphor is blended with at least about 0.4 mole percent SrCO 3 .
Claim 6
Dependent Claim
20 words
The method of claim 1 wherein the phosphor is blended with at least about 0.4 mole percent SrF 2 .
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein the phosphor is blended with at least about 5 mole percent NH 4 F.
References Cited (Backward Citations)
US4719033A
Cited
US5023015A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-02 | 1998-07-04 | 1999-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-02 | 2002-07-04 | 2003-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-02 | 2006-07-04 | 2007-01-03 | $7700.00 | Window Closed / Lapsed |