Method and apparatus for driving a liquid crystal display

摘要

The generation of flicker is prevented when the contrast of a displayed image is changed. The amplitude of the data voltage whose polarity is inverted at a timing synchronized with the display cycle of an image is changed based on the tone and the designed contrast. At the same time, the position (center) of 0 V relative to the amplitude of the data voltage is offset a larger amount as the contrast increases. This corrects a change V in voltage between the electrodes under the influence of the parasitic capacity of a TFT when the TFT is turned off, so that the voltage between the electrodes is also turned off despite the polarity of the data voltage applied to the liquid crystal, even when the designated contrast is relatively high and the amplitude of the data voltage is relatively small, and even when the designated contrast is relatively low and the amplitude of the data voltage is relatively large.