EP0160302A2
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EP
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Ferroelectric liquid crystal cell
Assignee: Hitachi Ltd
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Filing: 1985-04-30
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Granted: —
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Expires: 2005-04-30
Abstract
Abstract Orientation control films (4) are coated and rubbed on a pair of transparent substrates (2) on the side contiguous to the terroelectric liquid crystal layer (1) for aligning molecules threof. The film (4) is made of a polyimide Polymer prepared by ring closure by heating and dehydrating of a polyamic acid which is synthetized by condensing pyromelli- tie dianhydride with 4,4-diaminoterphenyl. A contrast ratio of the ferroelectric liquid crystal element is improved while keeping a high responsibility charactéristics of the férroelec- tric liquid crystal materials.
Inventors
- 👤 Kishiro Iwasaki
- 👤 Susumu Era
- 👤 Hisao Yokokura
- 👤 Tadao Nakata
- 👤 Akio Mukoh
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 21:05
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1046; C08G73/105; C08G73/1067; C08G73/1071; C09; C09K; C09K19/00; C09K19/02; C09K19/0225; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133711; G02F1/133723; C09K2323/00; C09K2323/02; C09K2323/027; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31721
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
177 words
A ferroelectric liquid crystal cell including a pair of substrates (2) at least one of which is transparent, a ferroelectric liquid crystal layer (1) sandwitched between said substrates (2), a pair of electrodes (3) fitted to said respective substrates (2) for applying an electric field to said ferroelectric liquid crystal layer (1), and a pair of rubbed orientation control films (4) formed on said respective substrates (2) on the side contiguous to said ferroelectric liquid crystal layer (1) for uniformly aligning the moleclues thereof wherein the improvement comprises: said orientation control film (4) being a member selected from among a polyimide polymer material having repeating units of the general formula wherein R represents a divalent group selected from among a polyimide polymer material having repeating units of the general formula wherein R represents a divalent group selected from among a polyimide polymer material having repeating units of the general formula wherein Ar represents a tetravalent group selected from among wherein R represents a divalent group selected from among wherein R 1 -R 5 represent lower alkyl groups.
Claim 2
Dependent Claim
177 words
A ferroelectric liquid crystal cell including a pair of substrates (2) at least one of which is transparent, a ferroelectric liquid crystal layer (1) sandwitched between said substrates (2), a pair of electrodes (3) fitted to said respective substrates (2) for applying an electric field to said ferroelectric liquid crystal layer (1), and a pair of rubbed orientation control films (4) formed on said respective substrates (2) on the side contiguous to said ferroelectric liquid crystal layer (1) for uniformly aligning the moleclues thereof wherein the improvement comprises: said orientation control film (4) being a member selected from among a polyimide polymer material having repeating units of the general formula wherein R represents a divalent group selected from among a polyimide polymer material having repeating units of the general formula wherein R represents a divalent group selected from among a polyimide polymer material having repeating units of the general formula wherein Ar represents a tetravalent group selected from among wherein R represents a divalent group selected from among wherein R 1 -R 5 represent lower alkyl groups.
Claim 3
Dependent Claim
66 words
A ferroelectric liquid crystal cell according to claim 1 wherein said orientation control film (4) being a polyimide polymer material having structural units of the general formula [I] is prepared by ring closure by heating and dehydrating of a polyamic. acid which is synthesized by condensing 3,3',4,4'-diphenyltetracarboxylic anhydride with a diamine selected from p-phenylenediamine: 4,4 1- diaminodiphenylether: 4,4'-diaminodiphenylmethane: NH 2 , m-phenylenediamine: 4,4'-diaminodiphenyl (benzidine): and 4,4'-diaminoterphenyl:
Claim 4
Dependent Claim
58 words
Ferroelectric liquid crystal cell ccording to claim 1 wherein said orientation control film being a polyimide polymer material having structural units of the general formula [II] is prepared by ring closure by heating and dehydrating of a polyamic acid which is synthesized by condensing pyromellitic dianhydride with a diamine selected from p-phenylenediamine: benzidine: NH 2 , and 4,4'-diaminoterphenyl:
References Cited (Backward Citations)
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