Patent ID: 7098884

Claim:
A method of driving a semiconductor display device, the semiconductor display device comprising: an opposing electrode; a plurality of pixels, each of which comprises: a pixel TFT; a pixel electrode; and a liquid crystal formed between the pixel electrode and the opposing electrode; and a plurality of signal lines, each of which is electrically connected to at least one of the pixel TFTs, the method comprising the steps of: inputting display signals to the pixel electrodes of the pixels through the pixel TFTs; and displaying an image corresponding to the display signals during a frame period, wherein each of the display signals has one of a positive polarity and a negative polarity relative to an electric potential of the opposing electrode in accordance with a polarity pattern; wherein the polarity pattern is maintained during the frame period, and irregularly changed to another polarity pattern after the frame period; wherein the display signals having a same polarity are input to the pixel electrodes through the pixel TFTs connected to one of the plurality of signal lines; wherein polarities of the display signals are independently controlled in each of the plurality of signal lines; and wherein polarities of the display signals input to the pixel electrodes through the pixel TFTs connected to one of the plurality of signal lines are changed together.