A display device with a touch screen having display pixels and optical sensors each arranged in a matrix. In the display device, a backlight controller controls a backlight unit to be turned ON in a data display duration and controls the backlight unit to be turned OFF in a sensor detection duration other than the data display duration. Consequently, the influence of backlight on a touch part when the shade of the touch part is to be detected, can be reduced and an accuracy in the detection of an optical sensor can be increased.