Patent ID: 7372443

Claim:
A drive circuit for driving a display device including an active matrix substrate provided with a plurality of pixel electrodes arranged in a matrix, an opposing substrate provided with a transparent opposing electrode, and a liquid crystal layer held between the active matrix substrate and the opposing substrate, the drive circuit comprising: a first signal supplying unit that supplies an image signal to the pixel electrodes; a first detector that detects, on the basis of the image signal per unit time, a first gray level characterizing the brightness of an image; a variation-signal setting unit that sets a variation signal on the basis of the first gray level; and a second signal supplying unit that supplies the variation signal to the opposing electrode, the liquid crystal layer being driven by an effective voltage signal generated by modulating the image signal using the variation signal, and the variation-signal setting unit setting the variation signal so that the gray level of the effective voltage signal becomes greater than the gray level of the image signal in accordance with an increase in the first gray level.