Divided periods by dividing a frame of a video signal are produced. A display element is ON-OFF controlled on a pixel-by-pixel basis according to a video signal in accordance with the divided periods preassigned to each gradation. The light amount of a light source for emitting light to the display element is controlled so that a first light amount in a first divided period corresponding to the lowest gradation except black display becomes a light amount lower than a second light amount in a second divided period other than the first divided period.