US4988880A
Expired / Lapsed
US
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X-ray intensifying screen containing hafnia phosphor
Assignee: Carestream Health Inc
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Filing: 1989-02-03
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Granted: 1991-01-29
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Expires: 2009-02-03
Abstract
Abstract An intensifying screen for producing a latent image in a silver halide radiographic element when imagewise exposed to X-radiation is disclosed. The screen contains a phosphor having a hafnia host containing zirconia in concentrations higher than those found in optical grade hafnia. The phosphor can include as an activator one or a combination of titanium, rare earth, and alkali metal ions. Phosphor preparation processes are also disclosed.
Inventors
- 👤 Philip S. Bryan
- 👤 Patrick M. Lambert
- 👤 Christine M. Towers
- 👤 Gregory S. Jarrold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:02
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/67; C09K11/671; C09K11/77; C09K11/7701; C09K11/7715; C09K11/7716; C09K11/7728; C09K11/7729; C09K11/7743; C09K11/7744; C09K11/7756; C09K11/7759; C09K11/776; G; G21; G21K; G21K4/00
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
109 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor host consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z wherein z is in the range of from 4×10 -4 to 0.3, said phosphor exhibiting a higher luminescence intensity when excited by X-radiation as compared to the phosphor as described above differing solely in that z is less than 4×10 -4 .
Claim 2
Dependent Claim
109 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor host consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z wherein z is in the range of from 4×10 -4 to 0.3, said phosphor exhibiting a higher luminescence intensity when excited by X-radiation as compared to the phosphor as described above differing solely in that z is less than 4×10 -4 .
Claim 3
Dependent Claim
21 words
An X-ray intensifying screen according to claim 1 in which z is in the range of from 1×10 -3 to 0.2.
Claim 4
Dependent Claim
21 words
An X-ray intensifying screen according to claim 2 in which z is in the range of from 2×10 -3 to 0.1.
Claim 5
Dependent Claim
121 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z M.sub.y wherein M represents ions of at least one alkali metal; y is in the range of from 1×10 -4 to 1; and z is in the range of from 4×10 -4 to 0.3, said phosphor exhibiting a higher luminescence intensity when excited by X-radiation as compared to the phosphor as described above absent M.
Claim 6
Dependent Claim
121 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z M.sub.y wherein M represents ions of at least one alkali metal; y is in the range of from 1×10 -4 to 1; and z is in the range of from 4×10 -4 to 0.3, said phosphor exhibiting a higher luminescence intensity when excited by X-radiation as compared to the phosphor as described above absent M.
Claim 7
Dependent Claim
21 words
An X-ray intensifying screen according to claim 4 in which y is in the range of from 1×10 -4 to 0.2.
Claim 8
Dependent Claim
14 words
An X-ray intensifying screen according to claim 4 in which M includes lithium ions.
Claim 9
Dependent Claim
25 words
An X-ray intensifying screen according to claim 6 in which M is lithium and y is in the range of from 8×10 -4 to 0.15.
Claim 10
Dependent Claim
21 words
An X-ray intensifying screen according to claim 7 in which z is in the range of from 1×10 -3 to 0.2.
Claim 11
Dependent Claim
20 words
An X-ray intensifying screen according to claim 4 in which M includes at least one of sodium and potassium ions.
Claim 12
Dependent Claim
33 words
An X-ray intensifying screen according to claim 9 in which M represents at least one of sodium and potassium and y is in the range of from 8×10 -4 to 7×10 -2 .
Claim 13
Dependent Claim
21 words
An X-ray intensifying screen according to claim 10 in which z is in the range of from 1×10 -3 to 0.2.
Claim 14
Dependent Claim
20 words
An X-ray intensifying screen according to claim 4 in which M includes at least one of cesium and rubidium ions.
Claim 15
Dependent Claim
25 words
An X-ray intensifying screen according to claim 4 in which M includes at least two alkali metal activators chosen from among lithium, sodium, and potassium.
Claim 16
Dependent Claim
16 words
An X-ray intensifying screen according to claim 13 in which M includes lithium and potassium ions.
Claim 17
Dependent Claim
112 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z Ti.sub.x wherein x is in the range of from 3×10 -4 to 1.0 and z is in the range of from 4×10 -4 to 0.3, said phosphor exhibiting a higher luminescence intensity when excited by X-radiation as compared to the phosphor as described above absent titanium.
Claim 18
Dependent Claim
112 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z Ti.sub.x wherein x is in the range of from 3×10 -4 to 1.0 and z is in the range of from 4×10 -4 to 0.3, said phosphor exhibiting a higher luminescence intensity when excited by X-radiation as compared to the phosphor as described above absent titanium.
Claim 19
Dependent Claim
21 words
An X-ray intensifying screen according to claim 15 in which x is in the range of from 3×10 -4 to 0.5.
Claim 20
Dependent Claim
21 words
An X-ray intensifying screen according to claim 16 in which x is in the range of from 3×10 -4 to 0.25.
Claim 21
Dependent Claim
21 words
An X-ray intensifying screen according to claim 17 in which z is in the range of from 1×10 -3 to 0.2.
Claim 22
Dependent Claim
136 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z L.sub.w wherein L represents at least one rare earth element selected from the group consisting of praseodymium, samarium, europium, gadolinium, terbium, dysprosium, and ytterbium; w is in the range of from 3×10 -4 to <5×10 -2 ; and z is in the range of from 4×10 -4 to 0.3, said phosphor exhibiting a higher luminescence intensity when excited by X-radiation as compared to the phosphor as described above absent L.
Claim 23
Dependent Claim
136 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z L.sub.w wherein L represents at least one rare earth element selected from the group consisting of praseodymium, samarium, europium, gadolinium, terbium, dysprosium, and ytterbium; w is in the range of from 3×10 -4 to <5×10 -2 ; and z is in the range of from 4×10 -4 to 0.3, said phosphor exhibiting a higher luminescence intensity when excited by X-radiation as compared to the phosphor as described above absent L.
Claim 24
Dependent Claim
110 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z M.sub.y Ti.sub.x wherein M represents at least one alkali metal; x is in the range of from 3×10 -4 to 1.0; y is in the range of from 6×10 -4 to 1.0; and z is in the range of from 4×10 -4 to 0.3.
Claim 25
Dependent Claim
110 words
An X-ray intensifying screen comprised of a support and a fluorescent layer containing an organic binder that is transparent to X-radiation and to radiation emitted when the layer is excited by X-radiation and a phosphor capable of absorbing X-radiation and emitting longer wavelength electromagnetic radiation comprised of monoclinic crystals of a hafnium dioxide phosphor consisting essentially of oxygen and combined elements satisfying the relationship Hf.sub.1-z Zr.sub.z M.sub.y Ti.sub.x wherein M represents at least one alkali metal; x is in the range of from 3×10 -4 to 1.0; y is in the range of from 6×10 -4 to 1.0; and z is in the range of from 4×10 -4 to 0.3.
Claim 26
Dependent Claim
44 words
An X-ray intensifying screen according to claim 20 in which x is in the range of from 3×10 -4 to 0.5; y is in the range of from 8×10 -4 to 0.2; and z is in the range of from 1×10 -3 to 0.2.
References Cited (Backward Citations)
US2314699A
Cited
US2402760A
Cited
US2542336A
Cited
US3640887A
Cited
US4006097A
Cited
US3905911A
Cited
US3905912A
Cited
US3941715A
Cited
US4014812A
Cited
JPS5358491A
Cited
US4112194A
Cited
US4068128A
Cited
US4153469A
Cited
US4153469B1
Cited
US4295989A
Cited
JPH0822263A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-28 | 1994-07-30 | 1995-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-28 | 1998-07-30 | 1999-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-28 | 2002-07-30 | 2003-01-29 | $7700.00 | Window Closed / Lapsed |