US5250330A
Expired / Lapsed
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Liquid crystal device
Assignee: Canon Inc
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Filing: 1991-10-22
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Granted: 1993-10-05
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Expires: 2011-10-22
Abstract
Abstract A liquid crystal device is formed by applying an alignment film comprising a polyimide which contains a structural unit represented by the following formula (I): ##STR1## wherein R 1 denotes a tetravalent organic residue group, R 2 denotes a divalent organic residue group, X denotes --NHR 3 or --OH, R 3 denotes an alkyl group having 5-20 carbon atoms, Y denotes --NHR 4 or --OH, and R 4 denotes an alkyl group having 5-20 carbon atoms with the proviso that both X and Y cannot be --OH and the --OH in X or Y can be removed by further cyclization. The liquid crystal device thus formed shows a high contrast display, particularly by multiplexing drive, free from after-image because of quick responsiveness.
Inventors
- 👤 Masanobu Asaoka
- 👤 Yasuto Kodera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:12
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133711; G02F1/133723; C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/14; C09; C09K; C09K2323/00; C09K2323/02; C09K2323/025; C09K2323/027; C09K2323/0271; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31721
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
121 words
A liquid crystal device, comprising: a pair of substrates and a chiral smectic liquid crystal disposed between the substrates; at least one of said pair of substrates having thereon an alignment film comprising a polyimide which contains a structural unit represented by the following formula (I): ##STR19## wherein R 1 denotes a tetravalent organic residue group, R 2 denotes a divalent organic residue group, X denotes --NHR 3 or --OH, R 3 denotes an alkyl group having 5-20 carbon atoms, Y denotes --NHR 4 or --OH, and R 4 denotes an alkyl group having 5-20 carbon atoms with the proviso that both X and Y cannot be --OH and the --OH in X or Y can be removed by further cyclization.
Claim 2
Dependent Claim
121 words
A liquid crystal device, comprising: a pair of substrates and a chiral smectic liquid crystal disposed between the substrates; at least one of said pair of substrates having thereon an alignment film comprising a polyimide which contains a structural unit represented by the following formula (I): ##STR19## wherein R 1 denotes a tetravalent organic residue group, R 2 denotes a divalent organic residue group, X denotes --NHR 3 or --OH, R 3 denotes an alkyl group having 5-20 carbon atoms, Y denotes --NHR 4 or --OH, and R 4 denotes an alkyl group having 5-20 carbon atoms with the proviso that both X and Y cannot be --OH and the --OH in X or Y can be removed by further cyclization.
Claim 3
Dependent Claim
28 words
A device according to claim 1, wherein at least one of R 1 and R 2 in the structural unit represented by the formula (I) contains a fluorine
Claim 4
Dependent Claim
27 words
A device according to claim 1, wherein the structural unit represented by the formula (I) is contained in a proportion of 0.5-30 wt. % in the polyimide.
Claim 5
Dependent Claim
31 words
A device according to claim 1, wherein the polyimide has a molecular weight of 10 4 to 10 5 as measured by GPC (gel permeation chromatography) for a corresponding polyamic acid.
Claim 6
Dependent Claim
21 words
A method for driving a liquid crystal device, comprising subjecting the liquid crystal device according to claim 1 to multiplexing drive.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-10-04 | 1997-04-05 | 1997-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-04 | 2001-04-05 | 2001-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-04 | 2005-04-05 | 2005-10-05 | $7700.00 | Window Closed / Lapsed |