Patent USH840H successfully refreshed from Google Patents.
USH840H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single-Schottky diode liquid crystal light valve and method
Assignee: United States Department of the Air Force
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Filing: 1989-01-09
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Granted: 1990-11-06
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Expires: 2009-01-09
Abstract
Abstract A single-Schottky liquid crystal is disclosed in which a series of Schottky contacts are made on one side of a photoconductor substrate by a metal matrix mirror, with a doped semiconductor back contact electrode on the other side of the substrate. The light valve offers several operational advantages over MOS devices, and is easier to fabricate than double-Schottky light valves. It can be operated either in an AC mode or, by doping the liquid crystal ions, in a DC mode.
Inventors
- 👤 Uzi Efron
- 👤 Paul O. Braatz
- 👤 Jan Grinberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 00:33
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
137 words
A method of operating a liquid crystal light valve, comprising, providing a liquid crystal light valve having a liquid crystal layer, a doped semiconductor photoconductor layer, a Schottky diode means in contact with the photoconductor layer between the liquid crystal and photoconductor layers, a doped semiconductor layer electrically contacting the opposite side of the photoconductor layer from the Schottky diode means, and a counter-electrode on the opposite side of the liquid crystal layer from the photoconductor layer, and applying an alternating voltage across the electrode and counter-electrode to operate the light valve in spaced periods of reverse bias on the Schottky diode means and substantial majority carrier depletion of the photoconductor layer, and intervening substantially shorter periods of forward bias on the Schottky diode means sufficient to substantially balance the current flow through the liquid crystal layer.
Claim 2
Independent Claim
137 words
A method of operating a liquid crystal light valve, comprising, providing a liquid crystal light valve having a liquid crystal layer, a doped semiconductor photoconductor layer, a Schottky diode means in contact with the photoconductor layer between the liquid crystal and photoconductor layers, a doped semiconductor layer electrically contacting the opposite side of the photoconductor layer from the Schottky diode means, and a counter-electrode on the opposite side of the liquid crystal layer from the photoconductor layer, and applying an alternating voltage across the electrode and counter-electrode to operate the light valve in spaced periods of reverse bias on the Schottky diode means and substantial majority carrier depletion of the photoconductor layer, and intervening substantially shorter periods of forward bias on the Schottky diode means sufficient to substantially balance the current flow through the liquid crystal layer.
Claim 3
Independent Claim
109 words
A method of operating a liquid crystal light valve, comprising: providing a liquid crystal light valve having a liquid crystal layer which is doped with current carrying ions, a doped semiconductor photoconductor layer, a Schottky diode means in contact with the photoconductor layer between the liquid crystal and photoconductor layers, a doped semiconductor layer electrically contacting the opposite side of the photoconductor layer from the Schottky diode means, and a counter-electrode on the opposite side of the liquid crystal layer from the photoconductor layer, and applying a substantially DC voltage across the electrode and counter-electrode to operate the light valve with the Schottky diode means substantially continuously reverse biased.
Claim 4
Independent Claim
109 words
A method of operating a liquid crystal light valve, comprising: providing a liquid crystal light valve having a liquid crystal layer which is doped with current carrying ions, a doped semiconductor photoconductor layer, a Schottky diode means in contact with the photoconductor layer between the liquid crystal and photoconductor layers, a doped semiconductor layer electrically contacting the opposite side of the photoconductor layer from the Schottky diode means, and a counter-electrode on the opposite side of the liquid crystal layer from the photoconductor layer, and applying a substantially DC voltage across the electrode and counter-electrode to operate the light valve with the Schottky diode means substantially continuously reverse biased.
References Cited (Backward Citations)
FR2227547B1
Cited
US4191454A
Cited
US4128312A
Cited
US4228449A
Cited
US4705345A
Cited
US4807976A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |