Patent ID: 7705815

Claim:
A backlight control unit for a liquid crystal display device, comprising: a liquid crystal panel for displaying an image; a backlight for providing light to the liquid crystal panel; a gate driving unit and a data driving unit for driving the liquid crystal panel; a timing controller for outputting signals to control the gate driving unit and the data driving unit, the timing controller including, an image data analyzer for calculating each representative gradation value by analyzing red, green, and blue gradations of the image data of one frame unit, and outputting two representative gradation values among three representative gradation values as maximum gradation value and minimum gradation value; and a dimming signal outputting unit for outputting a dimming control signal to control the light output amount of the backlight according to the maximum gradation value and minimum gradation value provided from the image data analyze; and an inverter for controlling the backlight to control a light output amount from the backlight according to the dimming control signal outputted from the timing controller, wherein the backlight duty ratio is determined by a difference between the maximum gradation value and the minimum gradation value.