Patent ID: 6538631
Filing Date: 2003-03-25
Classification: G09G

Abstract:
A source driving circuit for a liquid crystal display having a shift register, a sampling latch, a holding latch, a digital/analog converter, and an output buffer, comprising:n external capacitors charged with stepwise voltages between an upper voltage (VH) and a lower voltage (VL), respectively, wherein n is an integer no less than 2; a first polarity modulator for performing stepwise polarity modulation of odd-numbered source lines connected to the n external capacitors by providing load capacitors connected to the odd-numbered source lines with the stepwise polarity voltages from the n external capacitors and recovering at the n external capacitors the stepwise polarity voltages from the load capacitors connected to odd-numbered source lines; a second polarity modulator for performing stepwise polarity modulation of even-numbered source lines connected to the n external capacitors by providing load capacitors connected to the even-numbered source lines with the stepwise polarity voltages from the n external capacitors and recovering at the n external capacitors the stepwise polarity voltages from the load capacitors connected to even-numbered source lines, wherein the n external capacitors are connected to both the first polarity modulator and the second polarity modulator; and a plurality of multiplexers for selecting the output of the first polarity modulator or the second modulator in a polarity modulation phase, selecting an output of the output buffer in a gray scale phase, and for then outputting the selected outputs to pixels.