A drive circuit that is an example of the present invention is a drive circuit of a display device for outputting in parallel the analog picture signals generated based on the digital picture signals inputted in serial. This circuit comprises a level shift circuit for converting the voltage level of the digital picture signals that were inputted in serial, a D/A conversion circuit for generating analog picture signals based on the digital picture signals that were subjected to level conversion with the level shift circuit, and an expansion circuit connected to the output side of the D/A conversion circuit or between the level shift circuit and the D/A conversion circuit and serving to expand and hold the inputted serial picture signals in parallel and output the picture signals in parallel. The level shift circuit is thus formed in the front stage of the picture signal register circuit.