US4838651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection tube having an insulating layer of magnesium oxide and a high transmission metal grating
Assignee: Nokia Deutschland GmbH
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Filing: 1987-12-01
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Granted: 1989-06-13
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Expires: 2007-12-01
Abstract
Abstract A projection tube includes a liquid crystal cell having liquid crystal material sandwiched between two plates. The cell is addressable by an electron beam and serves as a light valve for plane-parallel light with which the projection tube is illuminated from behind. On the side facing the liquid crystal material, the plate on which the electron beam writes has dot coatings of indium-tin oxide to achieve a high resolution and a sharp definition of the image to be displayed on a screen. The side of the plate on which the electron beam writes has an insulating layer of magnesium oxide.
Inventors
- 👤 Jurgen Pottharst
- 👤 Kurt M. Tischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:49
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133348
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
86 words
A projection tube, comprising: an electron-beam-addressed liquid crystal cell having liquid crystal material sandwiched between first and second plates, the first plate forms a faceplate for the projection tube, and the second plate is written on by an electron beam; dot coatings of electrically conductive and transparent material are formed on a surface of the second plate facing the liquid crystal material; and an insulating layer of magnesium oxide is formed on a surface of the second plate that is written on by the electron beam.
Claim 2
Dependent Claim
86 words
A projection tube, comprising: an electron-beam-addressed liquid crystal cell having liquid crystal material sandwiched between first and second plates, the first plate forms a faceplate for the projection tube, and the second plate is written on by an electron beam; dot coatings of electrically conductive and transparent material are formed on a surface of the second plate facing the liquid crystal material; and an insulating layer of magnesium oxide is formed on a surface of the second plate that is written on by the electron beam.
Claim 3
Dependent Claim
17 words
A projection tube as claimed in claim 1, wherein the dot coatings are made of indium-tin oxide.
Claim 4
Dependent Claim
21 words
A projection tube as claimed in claim 2, wherein the dot coatings are arranged in the form of rows and columns.
Claim 5
Dependent Claim
18 words
A projection tube as claimed in claim 1, wherein the insulating layer is made of vapor-deposited magnesium oxide.
Claim 6
Dependent Claim
24 words
A projection tube as claimed in claim 1, additionally comprising a high transmission metal grating disposed between the insulating layer and the electron beam.
References Cited (Backward Citations)
US3982150A
Cited
US3293474A
Cited
US3825791A
Cited
US3908148A
Cited
US4683398A
Cited
US4744636A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |