Patent ID: 7916105

Claim:
A liquid crystal display device, comprising: a liquid crystal panel; a data driver configured to supply a pixel driving signal to pixels on the liquid crystal panel; an input unit configured to provide input video data to be supplied to the data driver; a low gray scale compensator configured to compensate a low gray scale value video data in the input video data to generate a high gray scale value video data; a selection controller configured to detect a brightness of the input video data; a frame delay unit configured to delay the input video data transmitted from the input unit to the low gray scale compensator; and a multiplexer configured to select the input video data or the high gray scale value video data generated by the low gray scale compensator, wherein the multiplexer is controlled by the selection controller, and wherein the selection controller includes; a first comparator configured to compare a gray scale value of the input video data with a reference gray scale value; an accumulator configured to count a number of low gray scale value video data in the first video data of one frame in response to a data clock according to the comparison result from the first comparator to produce a counted number; a latch configured to sample the counted number produced by the accumulator; a second comparator configured to compare the counted number sampled by the latch with a reference pixel number; and a logic operation unit configured to perform a logic operation on the comparison results of the first comparator and the second comparator to generate a selection control signal for controlling the multiplexer.