Patent ID: 7499014
Filing Date: 2009-03-03
Classification: G09G

Abstract:
1. A driving circuit of a liquid crystal display device for generating ramp signal comprising: a timing controller to output control signals and video data; a ramp signal generator to receive a ramp control signal output from the timing controller, and to generate and output a ramp signal by combining a gray voltage for each level and a precharging voltage for each gray voltage, wherein the precharging voltage data is at least two gray levels higher than that of the gray voltage; and a data driver to provide video signals to respective data lines by sampling/holding the ramp signal output from the ramp signal generator according to a value of the video data; wherein the ramp signal generator includes: a signal generator to receive a look-up table control signal (LUT control signal) from the timing controller, and to output a digital/analog converter control signal (DAC control signal), precharging voltage data and gray voltage data for each level; and a digital/analog converter to output a precharged ramp signal by converting the precharging voltage data and the gray voltage data for each level to analog signals according to the DAC control signal outputted from the signal generator; and wherein the signal generator includes: a look-up table having the precharging voltage data and the gray voltage data for each level; and a logic controller to receive the LUT control signal from the timing controller and to sequentially output the combined precharging voltage data and the data in the look-up table.