PURPOSE: To obtain a good picture quality without executing complicated processing by providing an idle time after the field scanning of an arc raster scan is ended, executing a stroke scan within this idle time, and displaying a video signal.

CONSTITUTION: An arc raster scanning signal generating circuit 1 outputs an arc raster scanning signal of an X direction and a Y direction by amplifying a prescribed sine signal and cosine signal corresponding to a count value of a bearing clock, in accordance with a count value of a distance clock, and a stroke scanning signal generating circuit 2 generates a stroke scanning signal of an X direction and a Y direction. A stroke scan is executed within an idle time after a field scan of an arc raster display has been ended. That is to say, a stroke video signal outputted from an ROM27 in this case is supplied to a CRT45 through a video amplifying circuit 43.