US4028550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray screens
Assignee: EIDP Inc
•
Filing: 1975-12-22
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Granted: 1977-06-07
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Expires: 1995-12-22
Abstract
Abstract X-ray screens having reduced mottle and exhibiting improved image quality are prepared using europium-activated fluorohalide phosphors having an aminocoumarin brightening agent added thereto.
Inventors
- 👤 James Paul Weiss
- 👤 Edward Dyal Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:39
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/06; C09K11/08; C09K11/77; C09K11/7728; C09K11/7732; C09K11/7733; G; G21; G21K; G21K4/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
20 words
A luminescent composition comprising a mixture of a europium-activated barium fluorohalide phosphor and an aminocoumarin brightening agent in a binder.
Claim 2
Dependent Claim
20 words
A luminescent composition comprising a mixture of a europium-activated barium fluorohalide phosphor and an aminocoumarin brightening agent in a binder.
Claim 3
Dependent Claim
12 words
The composition of claim 1 wherein the phosphor is Ba.sub..98 Eu.sub..02 FCl.
Claim 4
Dependent Claim
33 words
The composition of claim 1 wherein the aminocoumarin brightening agent has the formula ##STR2## wherein each of X 1 , X 2 , Y 1 , and Y 2 is hydrogen or alkyl.
Claim 5
Dependent Claim
15 words
An X-ray screen comprising a film support having the composition of claim 1 coated thereon.
Claim 6
Dependent Claim
27 words
An X-ray screen comprising a support bearing a thin layer of europium-activated Ba fluorohalide phosphor mixed with an aminocoumarin brightening agent and dispersed in a film-forming binder.
Claim 7
Dependent Claim
27 words
An X-ray screen comprising a support bearing a thin layer of europium-activated Ba fluorohalide phosphor mixed with an aminocoumarin brightening agent and dispersed in a film-forming binder.
Claim 8
Dependent Claim
19 words
The X-ray screen of claim 5 wherein a reflective layer is interposed between the support and the phosphor layer.
Claim 9
Dependent Claim
14 words
The X-ray screen of claim 5 wherein a protective topcoat covers the phosphor layer.
Claim 10
Dependent Claim
24 words
The X-ray screen of claim 5 wherein a K or Rb salt is added to the phosphor in an amount sufficient to reduce lag.
Claim 11
Dependent Claim
67 words
An X-ray screen comprising a polyethylene terephthalate film support bearing in order (1) a reflective layer of TiO 2 and K 2 O (TiO 2 ) 6 , in a binder, (2) a thin layer of Ba.sub..98 Eu.sub..02 FCl phosphor mixed with an aminocoumarin brightening agent in an amount up to 1% by wt. of the phosphor and dispersed in a binder, and (3) a protective topcoat.
Claim 12
Dependent Claim
67 words
An X-ray screen comprising a polyethylene terephthalate film support bearing in order (1) a reflective layer of TiO 2 and K 2 O (TiO 2 ) 6 , in a binder, (2) a thin layer of Ba.sub..98 Eu.sub..02 FCl phosphor mixed with an aminocoumarin brightening agent in an amount up to 1% by wt. of the phosphor and dispersed in a binder, and (3) a protective topcoat.
Claim 13
Dependent Claim
25 words
The X-ray screen of claim 9 wherein the brightening agent is formed from the reaction of 3-phenyl-7-aminocoumarin and diethylamine in the presence of cyanuric chloride.
Claim 14
Dependent Claim
13 words
The X-ray screen of claim 9 wherein the protective topcoat is cellulose acetate.
Claim 15
Dependent Claim
61 words
A luminescent composition comprising a mixture of (1) a europium-activated barium fluorohalide phosphor of the formula Ba 1 - (x +y ) Eu x Sr y FQ wherein Q is Br, Cl, or I, x is 0.0001 to 0.2 and y is 0 to 0.8, the foregoing proportions being in molar amounts, and (2) an aminocoumarin brightening agent, in a binder.
Claim 16
Dependent Claim
61 words
A luminescent composition comprising a mixture of (1) a europium-activated barium fluorohalide phosphor of the formula Ba 1 - (x +y ) Eu x Sr y FQ wherein Q is Br, Cl, or I, x is 0.0001 to 0.2 and y is 0 to 0.8, the foregoing proportions being in molar amounts, and (2) an aminocoumarin brightening agent, in a binder.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |