Patent ID: 8797253

Claim:
A liquid crystal display device having a liquid crystal panel for displaying an input video signal, a light source of a light-emitting diode for irradiating the liquid crystal panel, and a light emission luminance control circuit for controlling light emission luminance of the light-emitting diode, wherein, the light emission luminance control circuit controls the light emission luminance of the light-emitting diode with both a Pulse Width Modulation system in which duty indicating a lighting time per cycle in a pulse to turn on/off the light-emitting diode is changed, and a current value control system in which a value of a current to be flowed to the light-emitting diode is selected from among a plurality of setting values, the light emission luminance control circuit receiving a mode switching signal and a light modulation control signal, wherein the mode switching signal indicates an eco mode and a plurality of quality modes including a first quality mode and a second quality mode, the Pulse Width Modulation system adjusting the duty according to the light modulation control signal, the quality mode and the eco mode, the current value control system selecting the current value according to the light modulation control signal, the quality mode and the eco mode.