EP0422904A2
Expired / Lapsed
EP
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Method of driving antiferroelectric liquid crystal device
Assignee: Sharp Corp
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Filing: 1990-10-09
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Granted: —
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Expires: 2010-10-09
Abstract
Abstract A method of driving a liquid crystal device having a substrate on which a plurality of scanning electrodes are arrayed in parallel to each other and a substrate on which a plurality of signal electrodes are arrayed in parallel to each other, the substrates being opposed so that the scanning electrodes and the signal electrodes are intersectionally placed to each other, and sandwiching an antiferroelectric liquid crystal phase between the substrates, comprising the steps of: applying, at odd-numbered frames, a selection voltage whose average potential is positive followed by a non-selection voltage whose average potential is positive to each of the scanning electrodes, and applying, at even-numbered frames, a selection voltage whose average potential is negative followed by a non-selection voltage whose average potential is negative to each of the scanning electrodes, so as to control the bistable switching state of the antiferroelectric liquid crystal phase at a plurality of pixels defined by the intersection area of each of the scanning electrodes and each of the signal electrodes in combination with voltages applied to the each of the signal electrodes, thereby turning each pixel on or off to provide a predetermined image.
Inventors
- 👤 Mitsuhiro Koden
- 👤 Takaji Numao
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 13:10
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3622; G09G3/3629; G09G3/3633; C; C07; C07C; C07C57/00; C07C57/30; C07C57/32; G09G2310/00; G09G2310/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
192 words
A method of driving a liquid crystal device having a substrate on which a plurality of scanning electrodes are arrayed in parallel to each other and a substrate on which a plurality of signal electrodes are arrayed in parallel to each other, the substrates being opposed so that the scanning electrodes and the signal electrodes are intersectionally placed to each other, and sandwiching an antiferroelectric liquid crystal phase between the substrates, comprising the steps of: applying, at odd-numbered frames, a selection voltage whose average potential is positive followed by a non-selection voltage whose average potential is positive to each of the scanning electrodes, and applying, at even-numbered frames, a selection voltage whose average potential is negative followed by a non-selection voltage whose average potential is negative to each of the scanning electrodes, so as to control the tristable switching state of the anti-ferroelectric liquid crystal phase at a plurality of pixels defined by the intersection area of each of the scanning electrodes and each of the signal electrodes in combination with voltages applied to the each of the signal electrodes, thereby turning each pixel on or off to provide a predetermined image.
Claim 2
Independent Claim
192 words
A method of driving a liquid crystal device having a substrate on which a plurality of scanning electrodes are arrayed in parallel to each other and a substrate on which a plurality of signal electrodes are arrayed in parallel to each other, the substrates being opposed so that the scanning electrodes and the signal electrodes are intersectionally placed to each other, and sandwiching an antiferroelectric liquid crystal phase between the substrates, comprising the steps of: applying, at odd-numbered frames, a selection voltage whose average potential is positive followed by a non-selection voltage whose average potential is positive to each of the scanning electrodes, and applying, at even-numbered frames, a selection voltage whose average potential is negative followed by a non-selection voltage whose average potential is negative to each of the scanning electrodes, so as to control the tristable switching state of the anti-ferroelectric liquid crystal phase at a plurality of pixels defined by the intersection area of each of the scanning electrodes and each of the signal electrodes in combination with voltages applied to the each of the signal electrodes, thereby turning each pixel on or off to provide a predetermined image.
Claim 3
Dependent Claim
22 words
The method of claim 1 in which the selection voltage applied at the odd- or even-numbered frames has a stepwise uneven waveform.
Claim 4
Dependent Claim
21 words
The method of claim 1 in which the non-selection voltage applied at the odd- or even-numbered frames has an even waveform.
Claim 5
Dependent Claim
26 words
The method of claim 1 in which the voltage applied to the signal electrodes has a rectangular waveform whose average potential is kept to be zero.
Claim 6
Dependent Claim
30 words
The method of claim 1 in which the antiferroelectric liquid crystal phase comprises at least one compounds of: wherein n and m each denotes an integer of 6 to 12.
Claim 7
Independent Claim
157 words
A method of driving a liquid crystal device having a row-and-column matrix of display pixels and electrodes formed on opposed substrates between which is disposed an antiferroelectric liquid crystal phase material, the method comprising applying to said electrodes drive signals which drive the device repetitively in a succession of frames to form a desired display in which each pixel is put in an on or off condition according to the voltage applied across the liquid crystal at the position of that pixel, wherein the voltages applied to the pixels are reversed from one frame to the next, said voltages being such that for one of said on and off conditions a pixel switches between two out of three stable states of the liquid crystal between successive frames and such that for the other of said on and off conditions a pixel stays in the third of said three stable states of the liquid crystal in successive frames.
Claim 8
Independent Claim
157 words
A method of driving a liquid crystal device having a row-and-column matrix of display pixels and electrodes formed on opposed substrates between which is disposed an antiferroelectric liquid crystal phase material, the method comprising applying to said electrodes drive signals which drive the device repetitively in a succession of frames to form a desired display in which each pixel is put in an on or off condition according to the voltage applied across the liquid crystal at the position of that pixel, wherein the voltages applied to the pixels are reversed from one frame to the next, said voltages being such that for one of said on and off conditions a pixel switches between two out of three stable states of the liquid crystal between successive frames and such that for the other of said on and off conditions a pixel stays in the third of said three stable states of the liquid crystal in successive frames.
References Cited (Backward Citations)
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