In a hold-type display device, such as a liquid crystal display device, so-called blurring which appears on a profile of a displayed animated image can be suppressed without degrading the brightness of the image. An image based on video data to be inputted to a display device is displayed for every frame period and, thereafter, the image is masked with a blanking image. Here, the ratio between an image display period of the video data and a blanking image display period in one frame period is adjusted, based on the number of pixel rows selected in a pixel array in response to a scanning clock for respective periods, the frequency of the scanning clock, and shortening of a horizontal period of display signal inputting to every pixel row with respect to a horizontal scanning period of the video data, whereby the image can be efficiently cancelled using the blanking image.