A modulated data signal is generated so as to change such that a length of a data period indicative of a timing of writing of the gradation voltage signal to each of the pixel portions becomes a length according to a distance from the data driver to each of the pixel portions. The timing control unit writes a video data signal to a memory at a timing according to a data period of the video data signal. The timing control unit reads the video data signal from the memory at a timing according to a period as a result of correction of a data period of the modulated data signal on the basis of a difference between an average value of lengths of the data periods of the video data signals and an average value of lengths of the data periods of the modulated data signals.