US4539138A
Expired / Lapsed
US
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Phosphor
Assignee: Fujifilm Holdings Corp
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Filing: 1984-03-12
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Granted: 1985-09-03
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Expires: 2004-03-12
Abstract
Abstract A rare earth element activated divalent metal represented by the formula MIIFX.xSiO2:yLn wherein MII is at least one divalent metal selected from the group consisting of Ba, Ca, Sr, Mg, Zn and Cd; Ln is at least one rare earth element selected from the group consisting of Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Sm and Gd; X is at least one halogen selected from the group consisting of Cl, Br and I; x and y are numbers satisfying the condition 5x10-5</=x</=0.5 and of 0<y</=0.2, respectively. This phosphor has improved characteristics such as the high luminance of emission, the high powder fluidity and good afterglow property.
Inventors
- 👤 Junji Miyahara
- 👤 Takashi Nakamura
- 👤 Kenji Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:22
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7783; C09K11/7784; C09K11/7787; C09K11/7788; C09K11/7701; C09K11/7704; C09K11/7705; C09K11/7766; C09K11/7767; C09K11/7769; C09K11/777
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
111 words
A rare earth element activated divalent metal fluorohalide phosphor represented by the formula M.sup.II FX.xSiO.sub.2 :yLn wherein M II is at least one divalent metal selected from the group consisting of Ba, Ca, Sr, Mg, Zn and Cd; Ln is at least one rare earth element selected from the group consisting of Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Sm and Gd; X is at least one halogen selected from the group consisting of Cl, Br and I; and x and y are numbers satisfying the conditions of 10 -5 ≦x≦0.3 and 0<y≦0.2, respectively, and exhibiting a faster decay of afterglow than said phosphor, absent SiO 2 .
Claim 2
Dependent Claim
111 words
A rare earth element activated divalent metal fluorohalide phosphor represented by the formula M.sup.II FX.xSiO.sub.2 :yLn wherein M II is at least one divalent metal selected from the group consisting of Ba, Ca, Sr, Mg, Zn and Cd; Ln is at least one rare earth element selected from the group consisting of Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Sm and Gd; X is at least one halogen selected from the group consisting of Cl, Br and I; and x and y are numbers satisfying the conditions of 10 -5 ≦x≦0.3 and 0<y≦0.2, respectively, and exhibiting a faster decay of afterglow than said phosphor, absent SiO 2 .
Claim 3
Dependent Claim
20 words
A phosphor as defined in claim 1 wherein said x is a number satisfying the condition of 10 -4 ≦x≦0.2.
Claim 4
Dependent Claim
33 words
A phosphor as defined in claim 1 wherein said M II is at least one divalent metal selected from the group consisting of Ba, Ca and Sr, and said Ln is divalent Eu.
References Cited (Backward Citations)
CA896453A
Cited
US2409174A
Cited
US3448056A
Cited
JPS5023387A
Cited
US3951848A
Cited
US4057508A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |