Patent US4309481A successfully refreshed from Google Patents.
US4309481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter-coated phosphor
Assignee: Toshiba Corp
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Filing: 1980-04-09
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Granted: 1982-01-05
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Expires: 2000-04-09
Abstract
Abstract Disclosed is a filter-coated phosphor having phosphor particles coated with filter particles formed of pigments of the same color as that of light emitted from the phosphor, the phosphor particles coated with the filter particles being additionally coated with a borate compound. According to this filter-coated phosphor, the filter particles never exfoliate from the surfaces of the phosphor particles in a slurry, satisfactory dispersibility is obtained in the slurry, and the slurry pH is stable. A phosphor screen of a color picture tube obtained with use of the filter-coated phosphor exhibits highly outstanding contrast and luminous efficiency.
Inventors
- 👤 Tadashi Wakatsuki
- 👤 Takeshi Takahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:14
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/02; C09K11/025; C09K11/08; C09K11/77; C09K11/7783; C09K11/7784; C09K11/7787; C09K11/7789; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
65 words
A filter-coated phosphor having phosphor particles coated with filter particles formed of pigments of the same color as that of light emitted from said phosphor, said phosphor particles coated with said filter particles being additionally coated with a borate compound wherein the weight of phosphor particles, and the weight of said borate compound coating is 0.001 to 0.3% of the weight of the phosphor compound.
Claim 2
Dependent Claim
65 words
A filter-coated phosphor having phosphor particles coated with filter particles formed of pigments of the same color as that of light emitted from said phosphor, said phosphor particles coated with said filter particles being additionally coated with a borate compound wherein the weight of phosphor particles, and the weight of said borate compound coating is 0.001 to 0.3% of the weight of the phosphor compound.
Claim 3
Dependent Claim
15 words
A filter-coated phosphor according to claim 1, wherein said borate compound is water-insoluble metal borate.
Claim 4
Dependent Claim
22 words
A filter-coated phosphor according to claim 2, wherein said water-insoluble metal borate is a borate of a metal other than alkali metals.
Claim 5
Dependent Claim
28 words
A filter-coated phosphor according to claim 3, wherein said borate is selected among a group consisting of zinc borate, aluminum borate, barium borate, calcium borate, and strontium borate.
Claim 6
Dependent Claim
26 words
A filter-coated phosphor according to claim 1, wherein the weight of said borate compound coating is 0.001 to 0.1% of the weight of the phosphor particles.
Claim 7
Dependent Claim
19 words
A filter-coated phosphor according to claim 1, wherein said filter-coated phosphor is a red-emitting phosphor coated with indium sulfide.
Claim 8
Dependent Claim
28 words
A filter-coated phosphor according to any one of claims 1 to 6, wherein said filter particles are fixed on the phosphor particles by means of an organic binder.
Claim 9
Dependent Claim
15 words
A filter-coated phosphor according to claim 7, wherein said organic binder is acrylic resin emulsion.
References Cited (Backward Citations)
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US3294569A
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US4020231A
Cited
US4173660A
Cited
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Cited
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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) | 1985-01-04 | 1985-07-06 | 1986-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-04 | 1989-07-06 | 1990-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-04 | 1993-07-06 | 1994-01-05 | $7700.00 | Window Closed / Lapsed |