Patent ID: 7232248

Claim:
A display device comprising: a main screen disposed on an inner side of the display device; a sub screen disposed on an outer side of the display device and opposite to the main screen; a first light-emitting unit; a second light-emitting unit; and a control unit controlling the first and the second light-emitting units, wherein the first light-emitting unit couples between a first output terminal of the control unit and a reference terminal having a reference voltage level, and the second light-emitting unit couples between a second output terminal of the control unit and the reference terminal, wherein the current path between the first output terminal and the reference terminal is electrically independent of the current path between the second output terminal and the reference terminal; wherein the control unit drives the first light-emitting unit to emit a first light to the sub screen when the display device uses the sub screen; and wherein when the display device uses the main screen, the control unit drives the first and the second light-emitting units to respectively emit the first light and a second light to the main screen.