US4879059A
Expired / Lapsed
US
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Liquid crystal device
Assignee: Canon Inc
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Filing: 1987-08-31
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Granted: 1989-11-07
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Expires: 2007-08-31
Abstract
Abstract A liquid crystal device comprises a pair of substrates and a ferroelectric liquid crystal disposed between the substrates. At least one of the pair of substrates has an alignment control film formed of an aliphatic polyimide resin having a function of aligning said plurality of layers preferentially in one direction. The aliphatic polyimide resin film stably provides a uniform alignment state with a large tilt angle than a conventional alignment control film of polyimide or polyvinyl alcohol over a long period. The liquid crystal device also provides a color tone of black in its darkest state.
Inventors
- 👤 Yukio Hanyu
- 👤 Yukiko Futami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:27
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133711; G02F1/133723; C; C09; C09K; C09K19/00; C09K19/02; C09K19/0225; C09K2323/00; C09K2323/02; C09K2323/027; G02F1/137; G02F1/139; G02F1/141
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
48 words
A ferroelectric liquid crystal device comprising a pair oof sustrates an aligment control film of an aliphatic polyimide derived from a (i) tetracarboxylic acid or dianhydride and (ii) a diamine, at least one of which is aliphatic and a ferroelectric liquid crystal disposed between the pair of substrates.
Claim 2
Dependent Claim
48 words
A ferroelectric liquid crystal device comprising a pair oof sustrates an aligment control film of an aliphatic polyimide derived from a (i) tetracarboxylic acid or dianhydride and (ii) a diamine, at least one of which is aliphatic and a ferroelectric liquid crystal disposed between the pair of substrates.
Claim 3
Dependent Claim
92 words
A device according to claim 1, wherein said aliphatic polyamide has a structural unit represented by the formula: ##STR18## wherein R 2 is a tetravalent group, R 3 is a divalent group, at least one of R 2 and R 3 is an aliphatic group and the other can be an aromatic group and n is 0 or 1, said ferroelectric liquid crystal being disposed in a layer thin enough so as to release its helical structure and provide at least two bistable orientation states in the absence of an electric field.
Claim 4
Dependent Claim
33 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR19## wherein R 2 is an aliphatic group, and R 3 is an aromatic group.
Claim 5
Dependent Claim
19 words
A device according to claim 3, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR20##
Claim 6
Dependent Claim
19 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR21##
Claim 7
Dependent Claim
19 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR22##
Claim 8
Dependent Claim
19 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR23##
Claim 9
Dependent Claim
19 words
A device according to claim 2, wherein said aliphatic polyamide has a structural unit represented by the formula: ##STR24##
Claim 10
Dependent Claim
19 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR25##
Claim 11
Dependent Claim
33 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR26## wherein R 2 is an aromatic group and R 3 is an aliphatic group.
Claim 12
Dependent Claim
33 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR27## wherein R 2 is an aromatic group and R 3 is an alicyclic group.
Claim 13
Dependent Claim
33 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR28## wherein R 2 is an alicyclic group and R 3 is an aromatic group.
Claim 14
Dependent Claim
30 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR29## wherein R 2 and R 3 are respectively an aliphatic group.
Claim 15
Dependent Claim
36 words
A device according to claim 2, wherein said aliphatic polyimide has a structural unit represented by the formula: ##STR30## wherein R 2 and R 3 are aliphatic group, either one of which is an alicyclic group.
Claim 16
Dependent Claim
17 words
A device according to claim 1, wherein said aliphatic polyimide comprises 100-200,000 repetitions of the structural unit.
Claim 17
Dependent Claim
17 words
A device according to claim 1, wherein said aliphatic polyamide comprises 500-5000 repetitions of the structural unit.
Claim 18
Dependent Claim
16 words
A device according to claim 1, wherein said alignment control film has a uniaxial orientation axis.
Claim 19
Dependent Claim
16 words
A device according to claim 17, wherein said uniaxial orientation axis has been provided by rubbing.
Claim 20
Dependent Claim
17 words
A device according to claim 1, wherein said ferroelectric liquid crystal is in a chiral smectic phase.
Claim 21
Dependent Claim
30 words
A device according to claim 1, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal in a nonhelical structure and provides a tilt angle of 18° or above.
Claim 22
Dependent Claim
20 words
A device according to claim 1, wherein said aliphatic polyimide film has a thickness of 30 Å to 1 μ.
Claim 23
Dependent Claim
20 words
A device according to claim 1, wherein said aliphatic polymide film has a thickness of 50 Å to 2000 Å.
Claim 24
Dependent Claim
20 words
A device according to claim 1, wherein said aliphatic polyimide film has a thickness of 70 Å to 1000 Å.
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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) | 1992-11-06 | 1993-05-08 | 1993-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-06 | 1997-05-08 | 1997-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-06 | 2001-05-08 | 2001-11-07 | $7700.00 | Window Closed / Lapsed |