Patent ID: 6731261
Filing Date: 2004-05-04
Classification: G02F,G09G

Abstract:
A display device comprising:a first substrate having a plurality of row electrodes; a second substrate having a plurality of column electrodes; a layer of electro-optical material disposed between the first and second substrates, said layer of electro-optical material being capable of assuming a plurality of states, at least two states of which are stable in the absence of an electric field; drive means for driving the row electrodes with selection signals and for driving the column electrodes with data signals in conformity with an image to be displayed, wherein, in an operating state, the drive means provide a row electrode during a selection period with at least one pulsatory selection signal comprising a first sub-selection signal having a first amplitude and a first polarity, and a second sub-selection signal having substantially a same amplitude and duration as the first sub-selection signal and having a second polarity opposite to the first polarity, wherein, when the row electrode is being supplied with the first sub-selection signal, the drive means provides at least one of the column electrodes with a first sub-column signal having a second amplitude, the first sub-column signal having the first polarity for a first portion of the first sub-column signal and having the second polarity for a second portion of the first sub-column signal, and wherein, when the row electrode is being supplied with the second sub-selection signal, the drive means supplies the at least one column electrode with a second sub-column signal having substantially the same second amplitude, the second sub-column signal having the second polarity for a first portion of the second sub-column signal and having the first polarity for a second portion of the second sub-column signal, the first portion of the second sub-column signal being of equal duration to the first portion of the first sub-column signal, and the second portion of the second sub-column signal being of equal duration to the second portion of the first sub-column signal.