Patent US4932757A successfully refreshed from Google Patents.
US4932757A
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Ferroelectric liquid crystal device
Assignee: Canon Inc
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Filing: 1988-08-16
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Granted: 1990-06-12
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Expires: 2008-08-16
Abstract
Abstract A ferroelectric liquid crystal device comprises a pair of substrates each provided with an electrode, and a ferroelectric liquid crystal disposed between the pair of substrates. At least one of the pair of substrates has thereon an inorganic oxide layer which has a resistance of 1-10 5 Ω/cm 2 in the direction of the layer thickness and preferably has a pencil hardness of 4H or harder. Because of the provision of the inorganic oxide layer, the ferroelectric liquid crystal device shows good bistability on switching under application of pulse electric fields and yet free of short circuit between the upper and lower electrodes.
Inventors
- 👤 Yukio Hanyu
- 👤 Yutaka Inaba
- 👤 Akira Tsuboyama
- 👤 Akio Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:20
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133345; G02F1/137; G02F1/139; G02F1/141
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
93 words
In a ferroelectric liquid crystal device comprising a pair of substrated each provided with an electrode on the inner surface thereof, and a ferroelectric liquid crystal disposed between the pair of substrates, the improvement wherein at least one of said pair of substrates has an inorganic oxide layer having a resistance of from 1-10 5 Ω per unit area of 1 cm 2 in the direction of the layer thickness on the inner surface and has an alignment control layer having a thickness of 400 Å or less on the inorganic oxide layer.
Claim 2
Dependent Claim
93 words
In a ferroelectric liquid crystal device comprising a pair of substrated each provided with an electrode on the inner surface thereof, and a ferroelectric liquid crystal disposed between the pair of substrates, the improvement wherein at least one of said pair of substrates has an inorganic oxide layer having a resistance of from 1-10 5 Ω per unit area of 1 cm 2 in the direction of the layer thickness on the inner surface and has an alignment control layer having a thickness of 400 Å or less on the inorganic oxide layer.
Claim 3
Dependent Claim
19 words
A device according to claim 1, wherein said inorganic oxide layer shows a pencil hardness of 4H or harder.
Claim 4
Dependent Claim
17 words
A device according to claim 1, wherein said inorganic oxide layer has a thickness of 100-3000 Å.
Claim 5
Dependent Claim
19 words
A device according to claim 1, wherein said alignment control layer has a thickness of 100 Å or less.
Claim 6
Dependent Claim
20 words
A device according to claim 1, wherein said alignment control layer has a resistivity of 10 5 -10 14 Ω.cm.
Claim 7
Dependent Claim
32 words
A device according to claim 1, wherein said inorganic oxide layer has a resistance of 1-10 4 Ω per unit area of 1 cm 2 in the direction of the layer thickness.
Claim 8
Dependent Claim
32 words
A device according to claim 1, wherein said inorganic oxide layer has a resistance of 1-10 3 Ω per unit area of 1 cm 2 in the direction of the layer thickness.
Claim 9
Dependent Claim
20 words
A device according to claim 1, wherein said inorganic oxide layer comprises at least one species of Sn and Ti.
Claim 10
Dependent Claim
22 words
A device according to claim 1, wherein said ferroelectric liquid crystal has a spontaneous polarization of 15×10 -8 coulomb/cm 2 or larger.
Claim 11
Dependent Claim
22 words
A device according to claim 1, wherein said ferroelectric liquid crystal has a spontaneous polarization of 20×10 -8 coulomb/cm 2 or larger.
Claim 12
Dependent Claim
34 words
A device according to claim 1, wherein said ferroelectric liquid crystal is disposed in a layer thin enough to suppress the formation of its own helical structure in the absence of an electric field.
Claim 13
Dependent Claim
19 words
A device according to claim 11, wherein said ferroelectric liquid crystal is disposed in a thickness of 0.5-4 μm.
Claim 14
Dependent Claim
19 words
A device according to claim 11, wherein said ferroelectric liquid crystal is disposed in a thickness of 1-2.5 μm.
References Cited (Backward Citations)
US4367924A
Cited
JPS58172621A
Cited
US4563059A
Cited
US4693951A
Cited
US4681404A
Cited
US4715686A
Cited
US4615586A
Cited
US4738515A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |