Patent ID: 8269753

Claim:
A display device, comprising: a backlight light source; a photo sensing unit capable of detecting the light intensity of ambient light and outputting a photocurrent corresponding to the light intensity of the ambient light; a voltage supply unit, for providing a voltage, which makes the photo sensing unit output a certain amount of photocurrent, to the photo sensing unit; and a supply voltage control unit, for controlling the voltage supply unit by the way of modulating the voltage supplied to the photo sensing unit based on the operation status of the backlight light source; wherein the supply voltage control unit outputs a voltage of a first voltage to the photo sensing unit while the backlight light source is operating; and the supply voltage control unit outputs a voltage of a second voltage, which is different from the first voltage, to the photo sensing unit while the backlight light source is not operating, and wherein the voltage of the second voltage makes the photo sensing unit output a photocurrent with maximum value, and the voltage of the first voltage makes the photo sensing unit output a photocurrent with the value smaller than the maximum value.