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US4980559A
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X-ray intensifying screen including a titanium activated hafnium dioxide phospher containing europium to reduce afterglow
Assignee: Eastman Kodak Co
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Filing: 1989-11-15
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Granted: 1990-12-25
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Expires: 2009-11-15
Abstract
Abstract An intensifying screen is disclosed containing a phosphor composition comprised of monoclinic crystals of a titanium activated hafnia phosphor host containing europium ions to reduce afterglow. A phosphor composition in which zirconia is at least partially substituted for hafnia is also disclosed.
Inventors
- 👤 Philip S. Bryan
- 👤 Patrick W. Lambert
- 👤 Christine M. Towers
- 👤 Gregory S. Jarrold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:04
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7743; C09K11/7744; C09K11/67; C09K11/671; C09K11/7701; C09K11/7715; C09K11/7716; C09K11/7728; C09K11/7729; C09K11/7756; C09K11/7759; C09K11/776; C09K11/7766; C09K11/7767; C09K11/7769; C09K11/7783; C09K11/7784; C09K11/7787; G; G21; G21K; G21K4/00; C01; C01P; C01P2002/00; C01P2002/50; C01P2002/70; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
119 words
A screen comprised of a support and a fluorescent layer containing a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a titanium activated hafnium dioxide phosphor host, characterized in that the monoclinic crystals consist essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z Ti.sub.x M.sub.y Eu.sub.w wherein M represents at least one alkali metal; w is in the range of from 1×10 -6 to 1×10 -2 ; x is in the range of from 3×10 -4 to 1.0; y is up to 1; and z is up to 0.3, the phosphor exhibiting a reduced afterglow when excited by X-radiation as compared to the phosphor as defined above absent europium.
Claim 2
Dependent Claim
119 words
A screen comprised of a support and a fluorescent layer containing a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a titanium activated hafnium dioxide phosphor host, characterized in that the monoclinic crystals consist essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z Ti.sub.x M.sub.y Eu.sub.w wherein M represents at least one alkali metal; w is in the range of from 1×10 -6 to 1×10 -2 ; x is in the range of from 3×10 -4 to 1.0; y is up to 1; and z is up to 0.3, the phosphor exhibiting a reduced afterglow when excited by X-radiation as compared to the phosphor as defined above absent europium.
Claim 3
Dependent Claim
17 words
A screen according to claim 1 further characterized in that z is at least 4×10 -4 .
Claim 4
Dependent Claim
21 words
A screen according to claim 2 further characterized in that z is in the range of from 1×10 -3 to 0.2.
Claim 5
Dependent Claim
21 words
A screen according to claim 5 further characterized in that z is in the range of from 2×10 -3 to 0.1.
Claim 6
Dependent Claim
21 words
A screen according to claim 1 further characterized in that x is in the range of from 3×10 -4 to 0.5.
Claim 7
Dependent Claim
21 words
A screen according to claim 1 further characterized in that x is in the range of from 3×10 -4 to 0.25.
Claim 8
Dependent Claim
23 words
A screen according to claim 6 further characterized in that w is in the range of from 2×10 -4 to 2×10 -3 .
Claim 9
Dependent Claim
17 words
A screen according to claim 1 further characterized in that y is at least 1×10 31 4.
Claim 10
Dependent Claim
21 words
A screen according to claim 8 further characterized in that y is in the range of from 1×10 -4 to 0.2.
Claim 11
Dependent Claim
30 words
A screen according to claim 9 further characterized in that y is at least 8×10 -4 and the alkali metal ions include at least one of lithium, sodium, and potassium.
Claim 12
Dependent Claim
23 words
A screen according to claim 6 further characterized in that w is in the range of from 1×10 -5 to 5×10 -3 .
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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) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |