US4076897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low lag luminescent phosphors and X-ray screen containing the same
Assignee: EIDP Inc
•
Filing: 1977-03-14
•
Granted: 1978-02-28
•
Expires: 1997-03-14
Abstract
Abstract The addition of potassium or ribidium salts to europium-activated fluorohalide phosphors produces X-ray screens with low lag even at very low europium concentrations.
Inventors
- 👤 James Ray Joiner, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:25
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7728; C09K11/7732; C09K11/7733
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
52 words
A luminescent phosphor of the formula Ba 1- ( x+y)Eu x Sr y FQ wherein Q = Br, Cl, or I x = 0.0001 to 0.2, and y = 0 to 0.8 and wherein the crystal structure of the phosphor contains potassium or rubidium ions in an amount sufficient to reduce lag.
Claim 2
Dependent Claim
52 words
A luminescent phosphor of the formula Ba 1- ( x+y)Eu x Sr y FQ wherein Q = Br, Cl, or I x = 0.0001 to 0.2, and y = 0 to 0.8 and wherein the crystal structure of the phosphor contains potassium or rubidium ions in an amount sufficient to reduce lag.
Claim 3
Dependent Claim
18 words
An X-ray screen comprising the phosphor of claim 1 mixed with a binder and coated upon a support.
Claim 4
Dependent Claim
28 words
The X-ray screen of claim 2 wherein the phosphor is Ba 0 .98 Eu 0 .02 FCl and its crystal structure contains sufficient potassium ions to reduce lag.
References Cited (Backward Citations)
US2303917A
Cited
US2303963A
Cited
US3163610A
Cited
US3693006A
Cited
NL7206945A
Cited
US3951848A
Cited
US4028550A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |