US5268780A
Expired / Lapsed
US
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Liquid crystal device having a polyimide alignment film substituted with fluorine or a fluorine-containing group
Assignee: Canon Inc
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Filing: 1992-06-15
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Granted: 1993-12-07
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Expires: 2012-06-15
Abstract
Abstract A liquid crystal device is formed by applying an alignment film comprising a fluorine-containing polyimide having a substituent of a fluorine atom or a fluorine containing group in its moiety originated from the carboxylic acid anhydride on at least one of a pair of substrates sandwiching a chiral smectic liquid crystal. Preferably, the respective substrates are provided with such fluorine-containing polyimide alignment films which have been rubbed in directions which are substantially parallel with each other and identical to each other or which intersect each other at a small counter-clockwise intersection angle. The liquid crystal device thus formed shows a high contrast display, particularly by multiplexing drive, free from after-image because of quick responsiveness.
Inventors
- 👤 Yukio Hanyu
- 👤 Masanobu Asaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:28
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1039; C08G73/1067; C08G73/1071; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133711; G02F1/133723; C09; C09K; C09K2323/00; C09K2323/02; C09K2323/027; C09K2323/0271
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
80 words
A liquid crystal device, comprising a pair of substrates and a chiral smectic liquid crystal disposed between the substrates, each of said substrates having an alignment film comprising a polyimide including a carboxylic acid-originated moiety having a substituent of a fluorine atom or a fluorine-containing group, and a diamine-originated moiety free from a substituent of a fluorine atom or a fluorine-containing group; the alignment films on the pair of substrates having rubbing axes which are substantially parallel to each other.
Claim 2
Dependent Claim
80 words
A liquid crystal device, comprising a pair of substrates and a chiral smectic liquid crystal disposed between the substrates, each of said substrates having an alignment film comprising a polyimide including a carboxylic acid-originated moiety having a substituent of a fluorine atom or a fluorine-containing group, and a diamine-originated moiety free from a substituent of a fluorine atom or a fluorine-containing group; the alignment films on the pair of substrates having rubbing axes which are substantially parallel to each other.
Claim 3
Dependent Claim
23 words
A device according to claim 1, wherein the rubbing axes provided on the alignment films have directions which are identical to each other.
Claim 4
Dependent Claim
86 words
A liquid crystal device, comprising a pair of substrates and a chiral smectic liquid crystal disposed between the substrates, each of said substrates having an alignment film comprising a polyimide having a substituent of a fluorine atom or a fluorine-containing group in its carboxylic acid-originated moiety; the alignment films on the pair of substrates having rubbing axes which are substantially parallel to each other; wherein the rubbing axes provided to the alignment films have directions which intersect each other at an intersection angle of 2-15 degrees.
Claim 5
Dependent Claim
86 words
A liquid crystal device, comprising a pair of substrates and a chiral smectic liquid crystal disposed between the substrates, each of said substrates having an alignment film comprising a polyimide having a substituent of a fluorine atom or a fluorine-containing group in its carboxylic acid-originated moiety; the alignment films on the pair of substrates having rubbing axes which are substantially parallel to each other; wherein the rubbing axes provided to the alignment films have directions which intersect each other at an intersection angle of 2-15 degrees.
Claim 6
Dependent Claim
13 words
A device according to claim 3, wherein said intersection angle is 3-12 degrees.
Claim 7
Dependent Claim
118 words
A liquid crystal device, comprising a pair of substrates and a chiral smectic liquid crystal disposed between the substrates, each of said substrates having an alignment film comprising a polyimide having a substituent of a fluorine atom or a fluorine-containing group in its carboxylic acid-originated moiety; the alignment films on the pair of substrates having rubbing axes which are generally identical to each other; wherein the rubbing axis provided to the polyimide film disposed on one of the substrates which is farther from a viewing position is disposed to have a counter-clockwise angle 2-15 degrees from the rubbing axis provided to the polyimide film disposed on the other of the substrates which is closer to the viewing position.
Claim 8
Dependent Claim
118 words
A liquid crystal device, comprising a pair of substrates and a chiral smectic liquid crystal disposed between the substrates, each of said substrates having an alignment film comprising a polyimide having a substituent of a fluorine atom or a fluorine-containing group in its carboxylic acid-originated moiety; the alignment films on the pair of substrates having rubbing axes which are generally identical to each other; wherein the rubbing axis provided to the polyimide film disposed on one of the substrates which is farther from a viewing position is disposed to have a counter-clockwise angle 2-15 degrees from the rubbing axis provided to the polyimide film disposed on the other of the substrates which is closer to the viewing position.
Claim 9
Dependent Claim
18 words
A device according to claim 5, wherein the counter-clockwise angle is set within the range of 3-12 degrees.
Claim 10
Independent Claim
36 words
A device according to any of claims 1, 3 or 5, wherein said pair of substrates are disposed to have a spacing small enough to suppress a helical alignment structure of the chiral smectic liquid crystal.
Claim 11
Dependent Claim
154 words
A liquid crystal device, comprising: a pair of substrates, each of said substrates having an alignment film comprising a polyimide including a carboxylic acid-originated moiety having a substituent of a fluorine atom or a fluorine-containing group, and a diamine-originated moiety free from a substituent of a fluorine atom or a fluorine-containing group, wherein the alignment films on the pair of substrates have rubbing axes which are substantially parallel to each other; and said liquid crystal device further comprising a chiral smectic liquid crystal disposed between the pair of substrates wherein said pair of substrates are disposed to have a spacing small enough to suppress a helical alignment structure of the chiral smectic liquid crystal and wherein said chiral smectic liquid crystal has been cooled from a temperature higher than a temperature range which imparts to said chiral smectic liquid crystal a smectic A phase to thereby form at least two different stable orientation states.
Claim 12
Dependent Claim
154 words
A liquid crystal device, comprising: a pair of substrates, each of said substrates having an alignment film comprising a polyimide including a carboxylic acid-originated moiety having a substituent of a fluorine atom or a fluorine-containing group, and a diamine-originated moiety free from a substituent of a fluorine atom or a fluorine-containing group, wherein the alignment films on the pair of substrates have rubbing axes which are substantially parallel to each other; and said liquid crystal device further comprising a chiral smectic liquid crystal disposed between the pair of substrates wherein said pair of substrates are disposed to have a spacing small enough to suppress a helical alignment structure of the chiral smectic liquid crystal and wherein said chiral smectic liquid crystal has been cooled from a temperature higher than a temperature range which imparts to said chiral smectic liquid crystal a smectic A phase to thereby form at least two different stable orientation states.
Claim 13
Independent Claim
349 words
A device according to any of claims 1, 3, 5 or 8, wherein said polyimide has at least one structural unit represented by the following formulas (I)-(VIII): ##STR56## wherein l is an integer of 1-3 and m is 0 or an integer of 1-3; ##STR57## wherein R 21 and R 22 are respectively hydrogen atom, fluorine atom or CF 3 with proviso that at least one of R 21 and R 22 is fluorine atom or --CF 3 ; ##STR58## wherein R 31 , R 32 , R 33 and R 34 are respectively hydrogen atom, fluorine atom or --CF 3 with proviso that at least one of R 31 , R 32 , R 33 and R 34 is fluorine atom or --CF 3 ; ##STR59## wherein R 41 , R 42 , R 43 and R 44 are respectively hydrogen atom, fluorine atom or --CF 3 with proviso that at least one of R 41 , R 42 , R 43 and R 44 is fluorine atom or --CF 3 ; ##STR60## wherein R 51 -R 59 and R 10 -R 14 are respectively hydrogen atom, fluorine atom or --CF 3 with proviso that at least one of R 51 -R 59 and R 10 -R 14 is fluorine atom or --CF 3 ; ##STR61## wherein ##STR62## n 1 is 0 or an integer of 1-7, R 62 and R 67 are respectively hydrogen atom or --CF 3 , R 63 -R 66 are respectively hydrogen atom, alkyl group, halogen atom or --CF 3 with proviso that at least one of R 62 -R 67 is --CF 3 when n1=0; ##STR63## wherein ##STR64## n 2 is 0 or an integer of 1-7, R 72 and R 77 are respectively hydrogen atom or --CF 3 , R 73 -R 76 are respectively hydrogen atom, alkyl group, halogen atom or --CF 3 with proviso that at least one of R 72 -R 76 is --CF 3 when n 1 =0; and ##STR65## wherein l8, m8 and n8 are respectively 0 or an integer of 1-3 with proviso that l8+m8+n8≧1.
Claim 14
Independent Claim
39 words
A device according to any of claims 1, 3, 5 or 8, wherein at least one of the substrates is provided with an electrode and an insulating film and one of said alignment films disposed thereon in this order.
Claim 15
Independent Claim
30 words
A device according to any of claims 1, 3, 5 or 8, wherein said polyimide film having a thickness of 50-1000Å, and said insulating film has a thickness of 200-1000Å.
Claim 16
Independent Claim
23 words
A device according to any of claims 1, 3, 5 or 8, wherein said polyimide film has a thickness of 100Å or less.
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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) | 1996-12-06 | 1997-06-07 | 1997-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-12-06 | 2001-06-07 | 2001-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-12-06 | 2005-06-07 | 2005-12-07 | $7700.00 | Window Closed / Lapsed |