In one embodiment of the present invention, a display device is disclosed wherein if a frame luminance is less than a maximum value, the device creates a difference between luminance outputs in the two subframes and sets the luminance difference to a value less than a sub-maximum luminance which is a maximum luminance output in one subframe. With the arrangement, no complete switching of the subframes in which luminance outputs are made occurs at a grayscale level where low luminance replaces high luminance or vice versa. Thus, the grayscale level-luminance curve continues smoothly.