Patent ID: 9240153
Filing Date: 2016-01-19
CPC Classification: G02F,G09G

Claim Text:
1. A liquid crystal device having a first substrate, a second substrate, and liquid crystal provided between the first substrate and the second substrate, comprising: a plurality of scanning lines provided in the first substrate; a plurality of data lines provided in the first substrate; a plurality of switching elements provided in correspondence with intersections of the plurality of scanning lines and the plurality of data lines; a plurality of pixel electrodes connected to the plurality of switching elements; a common electrode provided in correspondence with the pixel electrodes; a control circuit that alternately supplies a first voltage and a second voltage higher than the first voltage to the common electrode; and a data line driving circuit that alternately supplies a positive-polarity image signal to the data lines after supplying the first voltage to the common electrode, of which an electric potential is higher than the first voltage, and a negative-polarity image signal to the data lines after supplying the second voltage to the common electrode, of which an electric potential is lower than the second voltage, to the plurality of data lines, wherein as the voltage of the common electrode drops the voltage of the corresponding pixel electrodes drop such that a potential difference between the voltage of the common electrode and the voltage of the pixel electrodes is maintained throughout a time period beginning when the voltage of the common electrode starts to drop and ending when the voltage of the common electrode stops dropping, wherein after a voltage supplied to said common electrode changes from the second voltage to the first voltage and after a selection voltage is supplied to one of the plurality of scanning lines, the positive-polarity image signal is supplied to the data lines, wherein after the voltage supplied to the common electrode changes from the first voltage to the second voltage and after the selection voltage is supplied to one of the plurality of scanning lines, the negative-polarity image signal is supplied to the data lines, wherein a length of a time that the voltage applied to the common electrode is the first voltage prior to positive polarity writing is substantially equal to a length of time that the voltage applied to the common electrode is the second voltage is at a high level prior to negative polarity writing, and wherein just before the writing of the image signal into a pixel electrode, a polarity of the pixel electrode becomes the same as a polarity of the common electrode.