Patent ID: 7804481

Claim:
A liquid crystal display (LCD) device, comprising: an LC panel including a first region having a plurality of pixel region to display image and a second region in the outside of the first region; a backlight that irradiates light a rear side of the LC panel; an inverter that supplies an output power to the backlight; a light sensing circuit that detects an amount of external light introduced to the LC panel by a first metal oxide semiconductor (MOS)-transistor and a second MOS-transistor serially connected to each other; an inverter driving controller that controls a driving of an inverter based on a voltage corresponding to the optical amount from the light sensing circuit; a second power terminal connected to each gate terminal of the first MOS-transistor and the second MOS-transistor; and an optical amount detecting terminal connected to a common connection point between a drain terminal of the first MOS-transistor and a source terminal of the second MOS-transistor, wherein the light sensing circuit is constructed so that the first MOS-transistor and the second MOS-transistor are serially connected to each other between a first power terminal and a ground terminal, wherein the first MOS-transistor and the second MOS-transistor are disposed in the second region so that the first MOS-transistor is exposed to external light and the second MOS-transistor is not exposed to external light.