EP0637622A1
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EP
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Liquid crystal device
Assignee: Canon Inc
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Filing: 1994-08-02
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Granted: —
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Expires: 2014-08-02
Abstract
Abstract A chiral smectic liquid crystal device with a good planar homogeneity in a layer normal direction can be constituted by disposing a chiral smectic liquid crystal having no cholesteric phase between a pair of substrates having mutually different characters, particularly in terms of Iso - SmA phase transition temperature. The liquid crystal may preferably have a layer spacing-changing characteristic such that it provides a layer spacing d A at a first transition point where the layer spacing of the liquid crystal begins to decrease on temperature decrease in the vicinity of a transition temperature from SmA phase to SmC* phase and a layer spacing d min at a second transition point where the layer spacing of the liquid crystal begins to increase on further temperature decrease from the first transition point, satisfying 0.96 ≦ d min /d A .
Inventors
- 👤 Yukio C/O Canon Kabushiki Kaisha Hanyu
- 👤 Katsutoshi C/O Canon Kabushiki Kaisha Nakamura
- 👤 Nobuhiro C/O Canon Kabushiki Kaisha Ito
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 08:10
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/141; G02F1/1416; C; C09; C09K; C09K19/00; C09K19/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
40 words
A liquid crystal device, comprising a pair of substrates and a liquid crystal disposed therebetween; wherein the liquid crystal has a phase transition series not showing cholesteric phase, and the pair of substrates have been subjected to asymmetrical aligning treatments.
Claim 2
Dependent Claim
143 words
A liquid crystal device, comprising a pair of substrates each having thereon a transparent electrode, and a liquid crystal disposed between the substrates, wherein the liquid crystal does not have cholesteric phase and has a layer spacing-changing characteristic such that it provides a layer spacing d A at a first transition point where the layer spacing of the liquid crystal begins to decrease on temperature decrease in the vicinity of a transition temperature from SmA phase to SmC* phase and a layer spacing d min at a second transition point where the layer spacing of the liquid crystal begins to increase on further temperature decrease from the first transition point, satisfying 0.96 ≦ d min /d A , and the pair of substrates are provided with means for providing different Iso - SmA phase transition temperatures at their boundaries with the liquid crystal.
Claim 3
Dependent Claim
22 words
A liquid crystal device according to Claim 2, wherein d min and d A satisfy 0.99 ≦ d min /d A .
Claim 4
Dependent Claim
30 words
A liquid crystal device according to Claim 3, wherein the means for providing different Iso - SmA phase transition temperature is given by an asymmetry between the pair of substrates.
Claim 5
Dependent Claim
20 words
A liquid crystal device according to Claim 4, wherein the pair of substrates are provided with mutually different alignment films.
Claim 6
Dependent Claim
18 words
A liquid crystal device according to Claim 5, wherein said mutually different alignment films provide different pretilt angles.
Claim 7
Dependent Claim
32 words
A liquid crystal device according to any one of Claims 2 - 6, wherein the different Iso - SmA phase transition temperatures differ from each other by at least 0.5 o C.
Claim 8
Dependent Claim
152 words
A liquid crystal device, comprising a pair of substrates each having thereon a transparent electrode, and a liquid crystal disposed between the substrates, wherein the liquid crystal does not have cholesteric phase and has a layer spacing-changing characteristic such that it provides a layer spacing d A at a first transition point where the layer spacing of the liquid crystal begins to decrease on temperature decrease in the vicinity of a transition temperature from SmA phase to SmC* phase and a layer spacing d min at a second transition point where the layer spacing of the liquid crystal begins to increase on further temperature decrease from the first transition point, satisfying 0.96 ≦ d min /d A , and either one of the pair of substrates is provided with an alignment film for uniaxially aligning the liquid crystal, the alignment film having a glass transition point of at least 200 o C.
Claim 9
Dependent Claim
22 words
A liquid crystal device according to Claim 8, wherein d min and d A satisfy 0.99 ≦ d min /d A .
Claim 10
Dependent Claim
144 words
A liquid crystal device, comprising a pair of substrates each having thereon a transparent electrode, and a liquid crystal disposed between the substrates, wherein the liquid crystal does not have cholesteric phase and has a layer spacing-changing characteristic such that it provides a layer spacing d A at a first transition point where the layer spacing of the liquid crystal begins to decrease on temperature decrease in the vicinity of a transition temperature from SmA phase to SmC* phase and a layer spacing d min at a second transition point where the layer spacing of the liquid crystal begins to increase on further temperature decrease from the first transition point, satisfying 0.96 ≦ d min /d A , and either one of the pair of substrates is provided with an alignment film for uniaxially aligning the liquid crystal, the alignment film comprising a polyimide.
Claim 11
Dependent Claim
22 words
A liquid crystal device according to Claim 10, wherein d min and d A satisfy 0.99 ≦ d min /d A .
Claim 12
Dependent Claim
168 words
A liquid crystal device, comprising a pair of substrates each having thereon a transparent electrode, and a liquid crystal disposed between the substrates, wherein the liquid crystal does not have cholesteric phase and has a layer spacing-changing characteristic such that it provides a layer spacing d A at a first transition point where the layer spacing of the liquid crystal begins to decrease on temperature decrease in the vicinity of a transition temperature from SmA phase to SmC* phase and a layer spacing d min at a second transition point where the layer spacing of the liquid crystal begins to increase on further temperature decrease from the first transition point, satisfying 0.96 ≦ d min /d A , and one of the pair of substrates is provided with a uniaxial alignment film having a glass transition point of at least 200 o C, and the other of the pair of substrates is provided with an alignment film which alone would provide a random alignment of the liquid crystal.
Claim 13
Dependent Claim
22 words
A liquid crystal device according to Claim 12, wherein d min and d A satisfy 0.99 ≦ d min /d A .
Claim 14
Dependent Claim
160 words
A liquid crystal device, comprising a pair of substrates each having thereon a transparent electrode, and a liquid crystal disposed between the substrates, wherein the liquid crystal does not have cholesteric phase and has a layer spacing-changing characteristic such that it provides a layer spacing d A at a first transition point where the layer spacing of the liquid crystal begins to decrease on temperature decrease in the vicinity of a transition temperature from SmA phase to SmC* phase and a layer spacing d min at a second transition point where the layer spacing of the liquid crystal begins to increase on further temperature decrease from the first transition point, satisfying 0.96 ≦ d min /d A , and one of the pair of substrates is provided with a uniaxial alignment film comprising a polyimide, and the other of the pair of substrates is provided with an alignment film which alone would provide a random alignment of the liquid crystal.
Claim 15
Dependent Claim
22 words
A liquid crystal device according to Claim 14, wherein d min and d A satisfy 0.99 ≦ d min /d A .
References Cited (Backward Citations)
No citation records indexed.
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