Patent EP0367531A2 successfully refreshed from Google Patents.
EP0367531A2
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Method of driving ferroelectric liquid crystal display panel
Assignee: Sharp Corp
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Filing: 1989-10-30
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Granted: —
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Expires: 2009-10-30
Abstract
Abstract In a method of driving a ferroelectric liquid crystal display panel, a non-selection voltage B is continuously applied to a scanning electrode L i from the time at which the selection voltage A is applied to the scanning voltage L i to the time at which the selection voltage A is again applied to the scanning electrode L₁, and a succeeding erasing voltage H is applied to the scanning electrode L i at the time N x t₀ before the application of the selection voltage A, whereby approximately the same effect as realized by the application of voltage -V g for P x t₀ can be provided on a pixel A ij , no matter whether a bright voltage D or a dark voltage E is applied to a signal electrode S j , so that the pixel A ij can be set to the dark memory state. At the time Q x t₀ before the application of the succeeding erasing voltage H to the scanning electrode L i , a compensation voltage G is applied, so that driving with no DC component left on the pixel A ij can be realized.
Inventors
- 👤 Takaji Numao
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 15:19
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3622; G09G3/3629; G09G2310/00; G09G2310/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
135 words
A method of driving a liquid crystal display panel having a plurality of scanning electrodes (L i , i is a positive integer) arranged parallel to each other, signal electrodes (S j , j is a positive integer) arranged parallel to each other intersecting said plurality of said scanning electrodes and ferroelectric liquid crystal (8) sealed between said plurality of scanning electrodes and the plurality of signal electrodes, comprising the steps of: applying a compensation voltage G followed by a succeeding erasing voltage H and thereafter applying a selection voltage A to the scanning electrode L i corresponding to a pixel to be displayed out of said plurality of scanning electrodes; and applying a bright voltage D to the signal electrode corresponding to said pixel to be displayed; whereby the corresponding pixel is turned on.
Claim 2
Independent Claim
135 words
A method of driving a liquid crystal display panel having a plurality of scanning electrodes (L i , i is a positive integer) arranged parallel to each other, signal electrodes (S j , j is a positive integer) arranged parallel to each other intersecting said plurality of said scanning electrodes and ferroelectric liquid crystal (8) sealed between said plurality of scanning electrodes and the plurality of signal electrodes, comprising the steps of: applying a compensation voltage G followed by a succeeding erasing voltage H and thereafter applying a selection voltage A to the scanning electrode L i corresponding to a pixel to be displayed out of said plurality of scanning electrodes; and applying a bright voltage D to the signal electrode corresponding to said pixel to be displayed; whereby the corresponding pixel is turned on.
Claim 3
Dependent Claim
148 words
A method of driving a ferroelectric liquid crystal display panel according to claim 1, wherein said compensation voltage G comprises a voltage which becomes negative for a prescribed time period, said succeeding erasing voltage H comprises a voltage which becomes positive for said predetermined time period; said selection voltage A comprises, in the former half of said predetermined time period, a negative voltage approximately equal to the succeeding erasing voltage H and, in the latter half of said predetermined time period, a positive voltage approximately equal to said compensation voltage G; and said bright voltage D comprises, in the former half of said predetermined time period, a positive voltage approximately equal to said selection voltage A in the latter half of the period, and in the latter half of the period, a negative voltage approximately equal to said selection voltage A in the former half of the period.
Claim 4
Dependent Claim
42 words
A method of driving a ferroelectric liquid crystal display panel according to claim 2, further comprising the steps of applying a dark voltage E to the signal electrode corresponding to said pixel to be displayed, whereby the corresponding pixel is turned off.
Claim 5
Dependent Claim
68 words
A method of driving a ferroelectric liquid crystal display panel according to claim 3, wherein said dark voltage E comprises, in the former half of said predetermined period, a positive voltage lower than said bright voltage D in the former half of the period, and, in the latter half of the period, a negative voltage higher than said bright voltage D in the latter half of the period.
Claim 6
Dependent Claim
49 words
A method of driving a ferroelectric liquid crystal display panel according to claim 4, further comprising the steps of applying a non-selection voltage B is applied to the scanning electrodes corresponding to the pixels other than said pixel to be displayed, whereby the pixels are set to non-selected state.
Claim 7
Dependent Claim
96 words
A method of driving a ferroelectric liquid crystal display panel according to claim 5, wherein said non-selection voltage B comprises, in the former half of said predetermined period, a positive voltage lower than said selection voltage A in the latter half of the period and higher than said dark voltage E in the former half of the period, and in the latter half of the period, a negative voltage higher than said selection voltage A in the former half of the period and lower than said dark voltage E in the latter half of the period.
Claim 8
Dependent Claim
38 words
Liquid crystal matrix display drive in which an erasing voltage (H) applied to a scanning electrode prior to the selection thereof by a selection voltage (A) is preceded by a compensation voltage (G) applied to that scanning electrode.
Claim 9
Dependent Claim
38 words
Liquid crystal matrix display drive in which an erasing voltage (H) applied to a scanning electrode prior to the selection thereof by a selection voltage (A) is preceded by a compensation voltage (G) applied to that scanning electrode.
Claim 10
Dependent Claim
21 words
A drive circuit for driving a liquid crystal display panel by a method according to any of claims 1 to 6.
References Cited (Backward Citations)
No citation records indexed.
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