EP0494626A2
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EP
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Ferroelectric liquid crystal element
Assignee: Canon Inc
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Filing: 1992-01-07
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Granted: —
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Expires: 2012-01-07
Abstract
Abstract In a ferroelectric liquid crystal element, which is constituted by holding a chiral smectic liquid crystal exhibiting ferroelectricity between electrode substrates, and in which the liquid crystal presents a plurality of surface stabilization states according to an electric field applied through the electrode substrates, and an alternating electric field having a strength equal to or higher than a constant value is applied during a period for inhibiting transition of the surface stabilization state, and to a corresponding liquid crystal portion, within a range causing no transition, the strength of the alternating electric field to be applied during the period for inhibiting transition of the surface stabilization state, and to the corresponding liquid crystal portion is set to be equal to or lower than a predetermined value which does not cause the liquid crystal to flow.
Inventors
- 👤 Yutaka C/O Canon Kabushiki Kaisha Inaba
- 👤 Shinjiro C/O Canon Kabushiki Kaisha Okada
- 👤 Osamu C/O Canon Kabushiki Kaisha Taniguchi
- 👤 Hironobu c/o Canon Kabushiki Kaisha Mizuno
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 14:46
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3622; G09G3/3629; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/141; G02F1/13787; G09G2310/00; G09G2310/02; G09G2310/0202; G09G2310/0205; G09G2310/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
131 words
A ferroelectric liquid crystal element, which is constituted by holding a chiral smectic liquid crystal exhibiting ferroelectricity between electrode substrates, and in which said liquid crystal presents a plurality of surface stabilization states according to an electric field applied through said electrode substrates, and an alternating electric field having a strength not less than a constant value is applied during a period for inhibiting transition of the surface stabilization state, and to a corresponding liquid crystal portion, within a range causing no transition, wherein the strength of the alternating electric field to be applied during the period for inhibiting transition of the surface stabilization state, and to the corresponding liquid crystal portion is set to be not more than a predetermined value which does not cause said liquid crystal to flow.
Claim 2
Dependent Claim
50 words
An element according to claim 1, wherein if the alternating electric field not less than the predetermined value is applied to cause the flow of said liquid crystal, a direction of the flow of said liquid crystal is reversed according to positive and negative levels of the alternating electric field.
Claim 3
Dependent Claim
69 words
An element according to claim 2, wherein if said liquid crystal is caused to flow, a velocity of the flow is low when a direction of the alternating electric field is the same as an average direction of directions of spontaneous polarization of said liquid crystal in an electric field non-application state, and is high when the direction of the alternating electric field is opposite to the average direction.
Claim 4
Dependent Claim
27 words
An element according to claim 1, wherein if said liquid crystal is caused to flow, a direction of the flow varies depending on the surface stabilization state.
Claim 5
Dependent Claim
72 words
An element according to claim 4, wherein a smectic layer of said liquid crystal is bent, and if said liquid crystal is caused to flow, an average molecular axis direction of said liquid crystal in an electric field application state is present inside an angle defined between a bisector direction of the bent corner, i.e., an outward direction of the bent corner, and a direction of the flow of said liquid crystal.
Claim 6
Dependent Claim
28 words
An element according to claim 1, wherein a force for causing said liquid crystal to flow is proportional to a strength of the electric field to be applied.
Claim 7
Dependent Claim
36 words
An element according to claim 6, wherein a force, from a surface of said electrode substrate, for preventing the flow of said liquid crystal varies depending on a direction to cause said liquid crystal to flow.
Claim 8
Dependent Claim
27 words
An element according to claim 1, wherein said opposing electrode substrates have different pre-tilt angles of said liquid crystal near said substrates in each surface stabilization state.
Claim 9
Dependent Claim
135 words
An element according to claim 1, wherein said opposing electrode substrates have a scanning electrode group for applying the electric field to said liquid crystal, and an information electrode group crossing said scanning electrode group, each crossing portion of said scanning and information electrode groups forms a pixel, in a scanning mode of the scanning electrodes, an electric field having a strength not less than a threshold value for transiting the surface stabilization state is applied to a pixel on the selected scanning electrode to transit the surface stabilization state of the pixel, and an electric field not less than the constant value within the range causing no transition, and not more than the predetermined value which does not cause said liquid crystal to flow is applied to a pixel on the non-selected scanning electrode.
References Cited (Backward Citations)
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