US5162930A
Expired / Lapsed
US
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Liquid-crystal light valve in combination with a cathode ray tube containing a far-red emitting phosphor
Assignee: Victor Company of Japan Ltd
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Filing: 1992-01-06
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Granted: 1992-11-10
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Expires: 2012-01-06
Abstract
Abstract A far-red emitting phosphor for cathode ray tubes used in liquid crystal light valves comprises lithium aluminum (or gallium) oxide, activated with iron or chromium. Increasing the activator concentration from 0.005 mole (commercially available) to about 0.015 to 0.05 mole increases the phosphor efficiency by about 50% and reduces the decay time from 30 msec (for the commerically available material) to 19 msec. Reducing the particle size to an average of 4 mu m or less provides the requisite high resolution for the CRT application.
Inventors
- 👤 Esther Sluzky
- 👤 Mary A. Lemoine
- 👤 Kenneth R. Hesse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:39
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
72 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 a compound selected from the group consisting of (a) LiAl0 2 doped with about 0.015 to 0.05 mole of iron and (b) LiGaO 2 doped with about 0.03 to 0.07 mole of iron.
Claim 2
Dependent Claim
72 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 a compound selected from the group consisting of (a) LiAl0 2 doped with about 0.015 to 0.05 mole of iron and (b) LiGaO 2 doped with about 0.03 to 0.07 mole of iron.
Claim 3
Dependent Claim
22 words
The combination of claim 1 wherein said phosphor consists essentially of LiAlO 2 doped with about 0.015 to 0.035 mole of iron.
Claim 4
Dependent Claim
14 words
The combination of claim 2 wherein the amount of iron is about 0.025 mole.
Claim 5
Dependent Claim
20 words
The combination of claim 1 wherein said phosphor consists essentially of LiGalO 2 doped with about 0.05 mole of iron.
Claim 6
Dependent Claim
18 words
The combination of claim 1 wherein said phosphor has a maximum average particle sizes of about 4 μm.
References Cited (Backward Citations)
US3857054A
Cited
US4350604A
Cited
US4799050A
Cited
US4925276A
Cited
JPH01215885A
Cited
US5009490A
Cited
US5084777A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-11-10 | 1996-05-11 | 1996-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-10 | 2000-05-11 | 2000-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-10 | 2004-05-11 | 2004-11-10 | $7700.00 | Window Closed / Lapsed |