Patent ID: 9024856
Filing Date: 2015-05-05
Classification: G09G

Abstract:
1. A signal driving circuit of a liquid crystal display device, the signal driving circuit comprising: a column driver configured to convert a video data into analog gray-scale voltages corresponding to a plurality of analog signal voltages and apply the analog gray-scale voltages to pixels of a liquid crystal panel; and an external voltage supplying unit comprising a digital to analog converting part that is coupled to a common electrode of the liquid crystal panel, wherein the digital to analog converting part is configured to: wherein, when the plurality of analog signal voltages are adjusted to vary a brightness of the liquid crystal panel, the plurality of adjusted analog signal voltages including a normal (+) adjusted gray-scale voltage and an inverse (−) adjusted gray-scale voltage, the common voltage supplied to the common electrode from the digital to analog converting part being adjusted such that the absolute values of the normal (+) adjusted gray-scale voltage and the inverse (−) adjusted gray-scale voltage have a same voltage difference with respect to the adjusted common voltage, the adjusted common voltage being supplied to the common electrode of the liquid crystal panel.