Liquid crystal drive circuit and liquid crystal display device

Abstract

Output circuits OC1-OC240 supplied with picture signals VIN to output drive signals are provided. Each of the output circuits OC includes a switching element SW1, a capacitor C1 and a switching element SW2 provided at a first path, and a switching element SW3, a capacitor C2 and a switching element SW4 provided at a second path connected in parallel with the first path, and includes a sample-hold circuit SH1 supplied with a picture signal and a hold switching signal of which level is switched at a first period to alternately store the picture signal into the capacitor C1 or the capacitor C2 in accordance with hold switching signal to output it, and an amplifier AMP1 supplied with an output of this circuit SH1 to amplify that output to output it as a drive signal. Further, buffers are provided every output circuits OC. These buffers are connected to each other in series. Hold switching signal inputted from the external is inputted to the buffers and are propagated therethrough. Thus, outputs from respective buffers are delivered to corresponding output circuits OC. By providing such configuration, in accordance with this invention, it is suppressed that rounding of waveform takes place by the influence of wiring resistor and/or parasitic capacitor for a time period during which hold switching signal is transferred through the signal line and feed-through current in carrying out switching operation is thus increased so that power consumption become large.