To sufficiently perform the frame display even by a signal of a short horizontal blanking period in a case when an image signal which has a number of picture elements less than that of a display unit, is to be displayed, by performing the writing of the signal for the frame display in a horizontal direction, within a vertical blanking period of an input image signal.

A source driver 104 is driven in such manner that only a source line of a part corresponding to a frame in a horizontal direction, is ON, and the condition is kept. An enable signal of the source driver 104 is kept in high level to make the writing of an image signal to an picture element corresponding to the frame in the horizontal direction, possible. The driving of a gate driver 105 is started, and the gate lines are successively switched on to perform the writing of the image signal to the picture element corresponding to the frame in the horizontal direction. The image level on this occasion, is kept in a black level when the display of the frame is black. And the input image signal is displayed on a center of a liquid crystal panel 108.