US5644193A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phosphor, cathode-ray tube, fluorescent lamp and radiation intensifying screen
Assignee: Toshiba Corp
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Filing: 1994-12-16
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Granted: 1997-07-01
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Expires: 2014-12-16
Abstract
Abstract Disclosed is a phosphor suitable for use in a cathode-ray tube, a fluorescent lamp, a radiation intensifying screen, which comprises transparent spherical particles having an average particle size of 0.5 to 20 μm and a ratio of the major diameter to the minor diameter of individual particles in the range of 1.0 to 1.5, and ultrafine particles having a diameter of 0.2 μm or less in an amount of 5 wt % or less.
Inventors
- 👤 Naotoshi Matsuda
- 👤 Masaaki Tamatani
- 👤 Keiko Albessard
- 👤 Miwa Okumura
- 👤 Takeshi Takahara
- 👤 Takeo Itou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:19
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/20; C; C09; C09K; C09K11/00; C09K11/08; C09K11/67; C09K11/671; C09K11/77; C09K11/7766; C09K11/7767; C09K11/7769; C09K11/7771; C09K11/7783; C09K11/7784; C09K11/7787; C09K11/7789; G; G21; G21K; G21K4/00; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/44; G21K2004/06; H01J61/70
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
57 words
A phosphor, comprising: transparent spherical particles having an average particle size of 0.5 to 20 μm and a ratio of the major diameter to the minor diameter of individual particles in the range of 1.0 to 1.5; and ultrafine particles having a diameter of 0.2 μm or less in an amount of 0.001-5 wt % or less.
Claim 2
Dependent Claim
57 words
A phosphor, comprising: transparent spherical particles having an average particle size of 0.5 to 20 μm and a ratio of the major diameter to the minor diameter of individual particles in the range of 1.0 to 1.5; and ultrafine particles having a diameter of 0.2 μm or less in an amount of 0.001-5 wt % or less.
Claim 3
Dependent Claim
101 words
The phosphor according to claim 1, represented by the formula: Ln 2 O 3 :R wherein Ln is at least one element selected from the group consisting of La, Gd, Lu and Y, and R is at least one element selected from the lanthanide group; and comprising, transparent spherical particles having an average particle size of 0.5 to 15 μm and a ratio of the major diameter to the minor diameter of individual particles in the range of 1.0 to 1.5, and ultrafine particles having a diameter of 0.2 μm or less in an amount of 0.001-2 wt % or less.
Claim 4
Dependent Claim
56 words
The phosphor according to claim 2, wherein said R is Eu and the molar ratio of Eu to Ln is 1 to 6%, said R is Tb and the molar ratio of Tb to Ln is 0.1 to 6%, or said R is Pr and the molar ratio of Pr to Ln is 0.01 to 5%.
Claim 5
Dependent Claim
38 words
The phosphor according to claim 2, represented by the formula: Gd 2 O 3 :R wherein R is at least one element selected from the lanthanide group; and at least part of crystalline system is a monoclinic system.
Claim 6
Dependent Claim
56 words
The phosphor according to claim 4, wherein said R is Eu and the molar ratio of Eu to Gd is 1 to 6%; said R is Tb and the molar ratio of Tb to Gd is 0.1 to 6%; or said R is Pr and the molar ratio of Pr to Gd is 0.01 to 5%.
Claim 7
Dependent Claim
36 words
The phosphor according to claim 4, represented by the formula: Gd 2 O 3 :Eu, wherein the content of the monoclinic system is 5 to 100% and the average particle size is 0.5 to 3 μm.
Claim 8
Dependent Claim
101 words
The phosphor according to claim 1, represented by the formula: Ln 2 O 2 S:R wherein Ln is at least one element selected from the group consisting of Y, La, Gd, and Lu, and R is at least one element selected from the lanthanide group; and comprising, transparent spherical particles having an average particle size of 0.5 to 15 μm and a ratio of the major diameter to the minor diameter of individual particles in the range of 1.0 to 1.5, and ultrafine particles having a diameter of 0.2 μm or less in an amount of 0.001-2 wt % or less.
Claim 9
Dependent Claim
56 words
The phosphor according to claim 7, wherein said R is Eu and the molar ratio of Eu to Ln is 2 to 7%; said R is Tb and the molar ratio of Tb to Ln is 0.1 to 6%; or said R is Pr and the molar ratio of Pr to Ln is 0.01 to 0.5%.
Claim 10
Dependent Claim
28 words
The phosphor according to claim 7, having reflectance for visual light of 85% or more when the phosphor is used in a layer having an optically indefinite thickness.
Claim 11
Dependent Claim
88 words
The phosphor according to claim 1, represented by the formula: MWO 4 wherein M is at least one component selected from the group consisting of Ca and Mg; or CaWO 4 :Pb, and comprising, transparent spherical particles having an average particle size of 0.5 to 20 μm and a ratio of the major diameter to the minor diameter of individual particles in the range of 1.0 to 1.5, and ultrafine particles having a diameter of 0.2 μm or less in an amount of 0.001-5 wt % or less.
Claim 12
Dependent Claim
27 words
The phosphor according to claim 10, wherein a content of said ultrafine particles having a diameter of 0.2 μm or less is 0.01 to 2 wt %.
References Cited (Backward Citations)
US2049765A
Cited
US2284055A
Cited
US2617773A
Cited
US2807586A
Cited
US2980550A
Cited
US3032428A
Cited
US3097172A
Cited
US3338841A
Cited
US3368980A
Cited
US3440080A
Cited
US3449258A
Cited
US3437432A
Cited
US4752424A
Cited
US4863882A
Cited
US5340673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-06-30 | 2000-12-30 | 2001-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-30 | 2004-12-30 | 2005-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-30 | 2008-12-30 | 2009-07-01 | $7700.00 | Window Closed / Lapsed |