In a video voltage comparator circuit, an average of first video voltages applied to pixel electrodes of pixels in the second-half rows in a k-th frame period (k is a natural number) is compared with an average of second video voltages applied to pixel electrodes of pixels in the first-half rows in a (k+1)th frame period for each row. In an overdrive voltage switching circuit, when a difference obtained from the comparison in the video voltage comparator circuit is greater than or equal to a threshold value, the overdrive voltage in the (k+1)th frame period is switched to a first overdrive voltage, and when the difference obtained from the comparison in the video voltage comparator circuit is less than the threshold value, the overdrive voltage in the (k+1)th frame period is switched to a second overdrive voltage lower than the first overdrive voltage.