Patent US3721630A successfully refreshed from Google Patents.
US3721630A
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Sulfur modified yttrium oxide phosphor
Assignee: GTE Sylvania Inc
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Filing: 1971-09-27
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Granted: 1973-03-20
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Expires: 1991-09-27
Abstract
Abstract Cathodoluminescent yttrium oxide phosphors activated with less than about 4 mole percent of europium are improved by a dopant of from about 1 to about 6 percent of sulfur which is incorporated during the firing step. The phosphors are brighter than prior art phosphors with the same color, in addition to having improved physical handling characteristics.
Inventors
- 👤 E Mehalchick
- 👤 J Mathers
- 👤 J Ferri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:47
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7783; C09K11/7784; C09K11/7787
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
19 words
A composition according to claim 1 wherein said sulfur is from about 2 to about 5 percent by weight.
Claim 2
Dependent Claim
18 words
A composition according to claim 2 wherein said europium is from about 3.0 to about 3.5 mole percent.
Claim 3
Dependent Claim
77 words
A process for producing a red-emitting cathodoluminescent phosphor composition comprising: a. forming a substantially uniform blend of yttrium oxide and europium oxide, said europium oxide being in fluorescence activating proportions but less than 4 moles per 100 moles of yttrium oxide and from about 1 to about 6 percent by weight of sulfur based upon said yttrium oxide, and b. firing said blend at a temperature of at least 2150* F for at least about 2 hours.
Claim 4
Dependent Claim
55 words
A process according to claim 4 wherein said yttrium oxide and said europium oxide are initially blended together with a borate source heated to at least about 1600* F and thereafter the resulting material is blended with said sulfur and a lithium source and heated to at least 2150* F for at least 2 hours.
Claim 5
Dependent Claim
19 words
A process according to claim 5 wherein said sulfur is from about 2 to about 5 percent by weight.
Claim 6
Dependent Claim
23 words
A process according to claim 6 wherein said europium oxide is from about 3.0 to about 3.5 moles per 100 moles yttrium oxide.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |