EP0295802A1
Expired / Lapsed
EP
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Liquid crystal display device
Assignee: Sharp Corp
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Filing: 1988-05-27
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Granted: —
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Expires: 2008-05-27
Abstract
Abstract A liquid crystal display device containing an X-Y matrix type liquid crystal display panel in which M pcs. (M > 1) of signal electrodes and N pcs. (N > 1) of scanning electrodes are arranged in a matrix, the liquid crystal display device comprising a device for reversing the polarity of the voltage waveform applied to the liquid crystal display panel at intervals of n (1 < n < N) horizontal scanning periods and for setting the reversing timing at random for every predetermined number of frames, say, every two frames.
Inventors
- 👤 Kunihiko Yamamoto
- 👤 Yutaka Ishii
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 00:34
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3614
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
89 words
A liquid crystal display device containing an X-Y matrix type liquid crystal display panel in which M pcs. (M > 1) of signal electrodes and N pcs. (N > 1) of scanning electrodes are opposed to each other in a matrix, said liquid crystal display device comprising means for reversing the polarity of the voltage waveform applied to the liquid crystal display panel at intervals of n (1 < n < N) horizontal scanning periods and for setting the reversing timing at random for every predetermined number of frames.
Claim 2
Dependent Claim
89 words
A liquid crystal display device containing an X-Y matrix type liquid crystal display panel in which M pcs. (M > 1) of signal electrodes and N pcs. (N > 1) of scanning electrodes are opposed to each other in a matrix, said liquid crystal display device comprising means for reversing the polarity of the voltage waveform applied to the liquid crystal display panel at intervals of n (1 < n < N) horizontal scanning periods and for setting the reversing timing at random for every predetermined number of frames.
Claim 3
Dependent Claim
84 words
The liquid crystal display device of claim 1, wherein said means is a polarity reversal control circuit comprising a random number generating circuit, a latch circuit for storing the output from said random number generating circuit for every predetermined number of frames, a frequency deviding counter which starts counting by reading the initial value for every predetermined number of frames, and a control signal output circuit which outputs a polarity reversal control signal on the basis of the output from said frequency dividing counter.
Claim 4
Dependent Claim
17 words
The liquid crystal display device of claim 1, wherein said predetermined number of frames is two frames.
Claim 5
Dependent Claim
41 words
A liquid crystal display device according to any preceding claim wherein said reversing and setting means is operable every said predetermined number of frames to select at random one of a plurality of possible polarity reversal control signals of different phases.
Claim 6
Dependent Claim
55 words
A liquid crystal display device according to claim 4 wherein said reversing and setting means is operable to effect said polarity reversing in accordance with a said randomly selected polarity reversal control signal during a said predetermined number of frames, but to invert the polarity reversing between successive frames of said predetermined number of frames.
References Cited (Backward Citations)
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