Patent ID: 7675497

Claim:
A driving unit for driving a liquid crystal display device, comprising; a data processing unit for selectively reversing and outputting bits exclusive of the most significant bit according to the most significant bit of the image data; an input register unit for sequentially storing N-bit image data provided from the data processing unit; a counter unit for counting based upon the N−1 bit image data to output control signals by receiving the N−1 bit image data exclusive of the most significant bit from the input register unit; a ramp signal generation unit for generating ramp signal, the ramp signal including a first ramp signal and a second ramp signal; a plurality of ramp signal selecting units for selecting the first ramp signal or the second ramp signal according to the most significant bits of the image data from the input register unit and outputting the selected ramp signal; and a plurality of switching units for sampling respectively the first ramp signal or the second ramp signal provided from the ramp signal selecting units according to the control signals of the counter unit and outputting the sampled ramp signal to data lines, wherein the second ramp signal is reversed from the first ramp signal by the control signal from the counting unit so that the voltage level of the first ramp signal at the sampling starting point is same as that of the reversed second ramp signal at the sampling starting point, wherein the data processing unit includes: an image data dividing unit for converting the second image data by selectively outputting first image data and second image data according to the most significant bit of N-bit image data; a data converting unit for reversing bits except for the most significant bit of the second image data input from the image data diving unit and outputting the converted second image data; and a multiplexer for selectively outputting one out of the first image data from the image data dividing unit and the converted second image data from the data converting unit according to a selection signal input from the image data diving unit.