EP0345904A2
Expired / Lapsed
EP
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Photostimulable phosphor and radiographic application
Assignee: Agfa Gevaert NV
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Filing: 1989-06-07
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Granted: —
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Expires: 2009-06-07
Abstract
Abstract A photostimulable rare earth metal doped barium strontium fluoride phosphor, characterized in that said phosphor is within the scope of following empirical formula (I) : Ba 1-x-y Sr x M y II F 2-a-b Br a X b :zA wherein : M II is at least one member selected from the group consisting of Mg and Ca; X is at least one member selected from the group consisting of Cl and I; x is in the range 0.05 ≦ x ≦ 0.55; y is in the range 0 < y < 0.05; a is in the range 0.70 ≦ a ≦ 0.96; b is in the range 0 ≦ b < 0.15; z is in the range 10⁻⁷ < z ≦ 0.15, and A is Eu²⁺ or Eu²⁺ together with one or more of the co-dopants selected from the group consisting of Eu³⁺, Y, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, La, Gd and Lu, and wherein fluorine is present stoichiometrically in said phosphor in a larger atom % than bromine taken alone or bromine combined with chlorine and/or iodine.
Inventors
- 👤 David Richard Terrell
- 👤 Albert Domien Adriaensens
- 👤 Lodewijk Marie Neyens
- 👤 Melvin Tecotzky
- 👤 Benjamas S. Davis
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 13:50
CPC Classifications
G; G21; G21K; G21K4/00; C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7728; C09K11/7732; C09K11/7733; C09K11/7783; C09K11/779; C09K11/7791
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
182 words
A photostimulable rare earth metal doped barium strontium fluoride phosphor, characterized in that said phosphor is within the scope of following empirical formula (I) : Ba 1-x-y Sr x M y II F 2-a-b Br a X b :zA wherein : M II is at least one member selected from the group consisting of Mg and Ca; X is at least one member selected from the group consisting of Cl and I; x is in the range 0.05 ≦ x ≦ 0.55; y is in the range 0 < y < 0.05; a is in the range 0.70 ≦ a ≦ 0.96; b is in the range 0 ≦ b < 0.15; z is in the range 10⁻⁷ < z ≦ 0.15, and A is Eu²⁺ or Eu²⁺ together with one or more of the co-dopants selected from the group consisting of Eu³⁺, Y, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, La, Gd and Lu, and wherein fluorine is present stoichiometrically in said phosphor in a larger atom % than bromine taken alone or bromine combined with chlorine and/or iodine.
Claim 2
Dependent Claim
182 words
A photostimulable rare earth metal doped barium strontium fluoride phosphor, characterized in that said phosphor is within the scope of following empirical formula (I) : Ba 1-x-y Sr x M y II F 2-a-b Br a X b :zA wherein : M II is at least one member selected from the group consisting of Mg and Ca; X is at least one member selected from the group consisting of Cl and I; x is in the range 0.05 ≦ x ≦ 0.55; y is in the range 0 < y < 0.05; a is in the range 0.70 ≦ a ≦ 0.96; b is in the range 0 ≦ b < 0.15; z is in the range 10⁻⁷ < z ≦ 0.15, and A is Eu²⁺ or Eu²⁺ together with one or more of the co-dopants selected from the group consisting of Eu³⁺, Y, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, La, Gd and Lu, and wherein fluorine is present stoichiometrically in said phosphor in a larger atom % than bromine taken alone or bromine combined with chlorine and/or iodine.
Claim 3
Dependent Claim
18 words
A photostimulable phosphor according to claim 1, wherein the co-dopant is Y or Eu³⁺ or a combination thereof.
Claim 4
Dependent Claim
83 words
A photostimulable phosphor according to claim 1, wherein z is in the range 10⁻⁶ ≦ z ≦ 10⁻²; A is Eu²⁺ alone or in admixture with at least one of the members selected from the group consisting of Eu³⁺, Y, Lu and Gd, and a is in the range 0.90 ≦ a ≦ 0.96 for x in the range 0.12 ≦ x ≦ 0.17 and in the range 0.85 ≦ a ≦ 0.96 for x in the range 0.17 ≦ x ≦ 0.55.
Claim 5
Dependent Claim
20 words
A photostimulable phosphor according to claim 1, wherein A is Eu²⁺ either or not in combination with Y and/or Eu³⁺.
Claim 6
Dependent Claim
142 words
A photostimulable phosphor according to claim 1, wherein said phosphor is a mixed doped phosphor prepared by fusing for about 2 h at temperatures between 700 and 1000°C in a reducing atmosphere Ba 1-x-y Sr x M y II F 2-a-b Br a X b :zEu wherein : M II is at least one member selected from the group consisting of Mg and Ca; X is at least one member selected from the group consisting of Cl and I; x is in the range 0.05 ≦ x ≦ 0.55; y is in the range 0 < y < 0.05; a is in the range 0.70 ≦ a ≦ 0.96; b is in the range 0 ≦ b < 0.15; z is in the range 10⁻⁷ < z ≦ 0.15, with "A" halide(s), wherein "A" is a co-dopant as defined in claim 1.
Claim 7
Dependent Claim
186 words
A radiation image storage panel comprising in a binder layer a photostimulable phosphor, characterized in that said phosphor is within the scope of the following empirical formula (I) : Ba 1-x-y Sr x M y II F 2-a-b Br a X b :zA wherein : M II is at least one member selected from the group consisting of Mg and Ca; X is at least one member selected from the group consisting of Cl and I; x is in the range 0.05 ≦ x ≦ 0.55; y is in the range 0 < y < 0.05; a is in the range 0.70 ≦ a ≦ 0.96; b is in the range 0 ≦ b < 0.15; z is in the range 10⁻⁷ < z ≦ 0.15, and A is Eu²⁺ or Eu²⁺ together with one or more of the co-dopants selected from the group consisting of Eu³⁺, Y, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, La, Gd and Lu, and wherein fluorine is present stoichiometrically in said phosphor in a larger atom % than bromine taken alone or bromine combined with chlorine and/or iodine.
Claim 8
Dependent Claim
186 words
A radiation image storage panel comprising in a binder layer a photostimulable phosphor, characterized in that said phosphor is within the scope of the following empirical formula (I) : Ba 1-x-y Sr x M y II F 2-a-b Br a X b :zA wherein : M II is at least one member selected from the group consisting of Mg and Ca; X is at least one member selected from the group consisting of Cl and I; x is in the range 0.05 ≦ x ≦ 0.55; y is in the range 0 < y < 0.05; a is in the range 0.70 ≦ a ≦ 0.96; b is in the range 0 ≦ b < 0.15; z is in the range 10⁻⁷ < z ≦ 0.15, and A is Eu²⁺ or Eu²⁺ together with one or more of the co-dopants selected from the group consisting of Eu³⁺, Y, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, La, Gd and Lu, and wherein fluorine is present stoichiometrically in said phosphor in a larger atom % than bromine taken alone or bromine combined with chlorine and/or iodine.
Claim 9
Dependent Claim
86 words
A radiation image storage panel according to claim 6, wherein wherein z is in the range 10⁻⁶ ≦ z ≦ 10⁻²; A is Eu²⁺ alone or in admixture with at least one of the members selected from the group consisting of Eu³⁺, Y, Lu and Gd, and a is in the range 0.90 ≦ a ≦ 0.96 for x in the range 0.12 ≦ x ≦ 0.17 and in the range 0.85 ≦ a ≦ 0.96 for x in the range 0.17 ≦ x ≦ 0.55.
Claim 10
Dependent Claim
22 words
A radiation image storage panel according to claim 6, wherein A is Eu²⁺ either or not in combination with Y and/or Eu³⁺.
Claim 11
Dependent Claim
29 words
A radiation image storage panel according to any of claims 6 to 8, wherein said phosphor is applied at a coverage in the range from 300 to 1500 g/m2.
Claim 12
Independent Claim
258 words
A method for recording and reproducing an X-ray image which method comprises the steps of : (1) image-wise exposing a photostimulable phosphor to X-rays, (2) photostimulating said phosphor with stimulating electromagnetic radiation selected from visible light and infrared light to release from said phosphor in accordance with the absorbed X-rays electromagnetic radiation different in wavelength characteristic from the radiation used in the photostimulation, and (3) detecting the light emitted by the photostimulation applied in step (2), characterized in that the phosphor subjected to the treatments of said steps (1) and (2) is within the scope of following empirical fomula (I) : Ba 1-x-y Sr x M y II F 2-a-b Br a X b :zA wherein : M II is at least one member selected from the group consisting of Mg and Ca; X is at least one member selected from the group consisting of Cl and I; x is in the range 0.05 ≦ x ≦ 0.55; y is in the range 0 < y < 0.05; a is in the range 0.70 ≦ a ≦ 0.96; b is in the range 0 ≦ b < 0.15; z is in the range 10⁻⁷ < z ≦ 0.15, and A is Eu²⁺ or Eu²⁺ together with one or more of the co-dopants selected from the group consisting of Eu³⁺, Y, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, La, Gd and Lu, and wherein fluorine is present stoichiometrically in said phosphor in a larger atom % than bromine taken alone or bromine combined with chlorine and/or iodine.
Claim 13
Independent Claim
258 words
A method for recording and reproducing an X-ray image which method comprises the steps of : (1) image-wise exposing a photostimulable phosphor to X-rays, (2) photostimulating said phosphor with stimulating electromagnetic radiation selected from visible light and infrared light to release from said phosphor in accordance with the absorbed X-rays electromagnetic radiation different in wavelength characteristic from the radiation used in the photostimulation, and (3) detecting the light emitted by the photostimulation applied in step (2), characterized in that the phosphor subjected to the treatments of said steps (1) and (2) is within the scope of following empirical fomula (I) : Ba 1-x-y Sr x M y II F 2-a-b Br a X b :zA wherein : M II is at least one member selected from the group consisting of Mg and Ca; X is at least one member selected from the group consisting of Cl and I; x is in the range 0.05 ≦ x ≦ 0.55; y is in the range 0 < y < 0.05; a is in the range 0.70 ≦ a ≦ 0.96; b is in the range 0 ≦ b < 0.15; z is in the range 10⁻⁷ < z ≦ 0.15, and A is Eu²⁺ or Eu²⁺ together with one or more of the co-dopants selected from the group consisting of Eu³⁺, Y, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, La, Gd and Lu, and wherein fluorine is present stoichiometrically in said phosphor in a larger atom % than bromine taken alone or bromine combined with chlorine and/or iodine.
Claim 14
Dependent Claim
85 words
A method according to claim 10, wherein in said phosphor z is in the range 10⁻⁶ ≦ z ≦ 10⁻²; A is Eu²⁺ alone or in admixture with at least one of the members selected from the group consisting of Eu³⁺, Y, Lu and Gd, and a is in the range 0.90 ≦ a ≦ 0.96 for x in the ranges 0.12 ≦ x ≦ 0.17 and in the range 0.85 ≦ a ≦ 0.96 for x in the range 0.17 ≦ x ≦ 0.55.
Claim 15
Dependent Claim
22 words
A method according to claim 10, wherein in said phosphor A is Eu²⁺ either or not in combination with Y and/or Eu³⁺.
Claim 16
Dependent Claim
15 words
A method according to claim 10, wherein the photostimulation proceeds with a scanning laser beam.
Claim 17
Dependent Claim
25 words
A method according to claim 10, wherein the detection of the light emitted by photostimulation proceeds with a phototube providing electrical signals that are digitized.
Claim 18
Dependent Claim
16 words
A method according to claim 14, wherein after storage said signals are subjected to digital processing.
Claim 19
Dependent Claim
30 words
A method according to claim 14, wherein digital signals obtained from analog-digital conversion of the electrical signals corresponding with the light obtained through photostimulation are displayed on a cathode-ray tube.
Claim 20
Dependent Claim
23 words
A method according to claim 14, wherein digital signals are transformed into analog signals that are used to modulate a writing laser beam.
References Cited (Backward Citations)
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