US4861143A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display capable of displaying grey tone
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1987-12-02
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Granted: 1989-08-29
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Expires: 2007-12-02
Abstract
Abstract A liquid crystal display of the chiral smectic type is caused to have grey scales, by applying a voltage of an intermediate level to the liquid crystal. Within each picture element of the display, there are a number of domains of the liquid crystal layer, some being transparent while the other being opaque rendering grey tone to the picture element.
Inventors
- 👤 Shunpei Yamazaki
- 👤 Takashi Inujima
- 👤 Toshimitsu Konuma
- 👤 Toshiji Hamatani
- 👤 Akira Mase
- 👤 Mitsunori Sakama
- 👤 Minoru Miyazaki
- 👤 Kaoru Koyanagi
- 👤 Toshiharu Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:52
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/141; G02F1/133; G02F1/1333; G02F1/1343; G02F1/13439; G02F1/133371; G02F2203/00; G02F2203/30
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
167 words
A display device comprising: a liquid crystal device including a transparent substrate, an opposed substrate, a smectic liquid crystal layer disposed between said substrates and a pair of electrodes formed on the both insides of said substrates in order to define a plurality of pixels, each said pixel of said liquid crystal device being provided with a corrugated inside surface contiguous to said liquid crystal layer so that a number of narrower liquid crystal layer regions and a number of wider liquid crystal layer regions are disposed over each pixel; means for applying a first voltage to said pair of electrodes so that said liquid crystal device is made transparent inbetween; means for applying a second voltage to said pair of electrodes so that said liquid crystal device is made opaque inbetween; and means for applying an intermediate voltage between said first and second voltages to said pair of electrodes so that each said pixel subjected to said intermediate voltage is provided with a grey scale tone.
Claim 2
Dependent Claim
167 words
A display device comprising: a liquid crystal device including a transparent substrate, an opposed substrate, a smectic liquid crystal layer disposed between said substrates and a pair of electrodes formed on the both insides of said substrates in order to define a plurality of pixels, each said pixel of said liquid crystal device being provided with a corrugated inside surface contiguous to said liquid crystal layer so that a number of narrower liquid crystal layer regions and a number of wider liquid crystal layer regions are disposed over each pixel; means for applying a first voltage to said pair of electrodes so that said liquid crystal device is made transparent inbetween; means for applying a second voltage to said pair of electrodes so that said liquid crystal device is made opaque inbetween; and means for applying an intermediate voltage between said first and second voltages to said pair of electrodes so that each said pixel subjected to said intermediate voltage is provided with a grey scale tone.
Claim 3
Dependent Claim
18 words
The display of claim 1 including a plurality of pairs of electrodes which are formed in a matrix.
Claim 4
Dependent Claim
18 words
The display of claim 1 wherein said liquid crystal layer is made of a chiral smectic liquid crystal.
Claim 5
Dependent Claim
27 words
The display of claim 3 wherein said liquid crystal device exhibits apparent hysteresis with reference to the transmissivity of said liquid crystal layer and the applied voltage.
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) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |