US5140449A
Expired / Lapsed
US
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Liquid crystal light valve in combination with a cathode ray tube containing a far-red emitting double-activated yttrium aluminum garnet phosphor
Assignee: Victor Company of Japan Ltd
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Filing: 1992-01-30
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Granted: 1992-08-18
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Expires: 2012-01-30
Abstract
Abstract A doubly activated yttriuim aluminum garnet (YAG) phosphor, activated with both europium and chromium, is provided. The concentration of Eu ranges from about 1 to 5 at %, while the concentration of Cr ranges from about 0.1 to 1 at %. The YAG:Eu,Cr phosphor has a line spectrum which more closely matches the spectral sensitivity of amorphous silicon liquid crystal light valves thereby, providing more efficient use of the available energy.
Inventors
- 👤 Esther Sluzky
- 👤 Mary A. Lemoine
- 👤 Kenneth R. Hesse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:01
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; H04N9/315; H04N9/3158; C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7783; C09K11/7792; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
67 words
In combination, a liquid crystal light valve including a photosensitive layer consisting essentially of a hydrogenated α-silicon photoconductor and a cathode ray tube containing a far-red emitting phosphor operatively coupled thereto, characterized in that said phosphor consists essentially of yttrium aluminum garnet activated with about 1 to 5 at % europium ions and about 0.1 to 1 at % chromium ions, based on the total cation concentration.
Claim 2
Dependent Claim
67 words
In combination, a liquid crystal light valve including a photosensitive layer consisting essentially of a hydrogenated α-silicon photoconductor and a cathode ray tube containing a far-red emitting phosphor operatively coupled thereto, characterized in that said phosphor consists essentially of yttrium aluminum garnet activated with about 1 to 5 at % europium ions and about 0.1 to 1 at % chromium ions, based on the total cation concentration.
Claim 3
Dependent Claim
16 words
The combination of claim 1 wherein the amount of chromium ions is about 0.25 at %.
Claim 4
Dependent Claim
19 words
The combination of claim 1 wherein said phosphor has an average particle size of less than about 6 μm.
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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) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |