Patent US4790631A successfully refreshed from Google Patents.
US4790631A
Expired / Lapsed
US
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Liquid crystal device with ferroelectric liquid crystal adapted for unipolar driving
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1987-12-31
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Granted: 1988-12-13
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Expires: 2007-12-31
Abstract
Abstract A liquid crystal device can be controlled by applying a positive (or negative) voltage to certain pixels and by removing the applied voltage through a main electrode arrangement in the form of a matrix. The liquid crystal layer embodying the liquid crystal device is entirely subjected, during operation, to a reverse electric field by a reverse voltage applied to an adjunct electrode arrangement. With this structure, each pixel defined in the liquid crystal layer is always subjected to an electric field so that a highly stabilized operation can be realized.
Inventors
- 👤 Shunpei Yamazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:28
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/134336; G02F1/137; G02F1/139; G02F1/141
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
102 words
A liquid crystal device comprising: a pair of substrates, at least one of which is transparent; a layer of ferroelectric liquid crystal interposed between said substrates having two stable states; an adjunct electrode arrangement for inducing an electric field normal to said substrate in said liquid crystal layer, in order that said liquid crystal layer be in one of of said states; and a main electrode arrangement for selectively inducing a reverse electric field in at least one of the pixels which are defined by said main electrode arrangement and change the state of the pixel subjected to said reverse electric field.
Claim 2
Dependent Claim
102 words
A liquid crystal device comprising: a pair of substrates, at least one of which is transparent; a layer of ferroelectric liquid crystal interposed between said substrates having two stable states; an adjunct electrode arrangement for inducing an electric field normal to said substrate in said liquid crystal layer, in order that said liquid crystal layer be in one of of said states; and a main electrode arrangement for selectively inducing a reverse electric field in at least one of the pixels which are defined by said main electrode arrangement and change the state of the pixel subjected to said reverse electric field.
Claim 3
Dependent Claim
59 words
The device of claim 1 wherein said main electrode arrangement comprises a plurality of first conductive strips extending parallel in one direction on the inside surface of one of said substrates, and a plurality of second conductive strips extending parallel in the perpendicular direction to said first conductive strips to form a matrix structure with said first conductive strips.
Claim 4
Dependent Claim
30 words
The device of claim 2 wherein said adjunct electrode arrangement comprises a first conductive film underlying said first conductive strips and a second conductive film underlying said second conductive strips.
Claim 5
Dependent Claim
61 words
The device of claim 1 wherein said main electrode arrangement comprises a first conductive pattern formed on one of said substrates and a second conductive pattern formed on the other substrate, and said adjunct electrode arrangement comprises a third conductive pattern underlying said first conductive pattern on said one substrate and said second conductive pattern shared with said main electrode arrangement.
References Cited (Backward Citations)
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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) | 1991-12-13 | 1992-06-13 | 1992-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-13 | 1996-06-13 | 1996-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-13 | 2000-06-13 | 2000-12-13 | $7700.00 | Window Closed / Lapsed |