Patent US4879059A successfully refreshed from Google Patents.
US4879059A
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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 03:21
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.
References Cited (Backward Citations)
US3994567A
Cited
US4068923A
Cited
US4278326A
Cited
US4311785A
Cited
US4405208A
Cited
JPS56111833A
Cited
US4381886A
Cited
US4366230A
Cited
JPS57135921A
Cited
EP0059790A1
Cited
US4590103A
Cited
US4514043A
Cited
GB2101760A
Cited
JPS5817417A
Cited
JPS5817418A
Cited
US4593977A
Cited
JPS5862620A
Cited
US4494824A
Cited
EP0091661A1
Cited
US4586791A
Cited
US4576732A
Cited
EP0130481A1
Cited
US4561726A
Cited
JPS60230605A
Cited
JPS60230625A
Cited
US4634228A
Cited
US4723839A
Cited
DE3605147A1
Cited
JPS61226733A
Cited
JPS61226732A
Cited
JPS62144141A
Cited
EP0231781A1
Cited
EP0247637A1
Cited
EP0249881A1
Cited
US4749777A
Cited
JPH06147932A
Cited
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 |