Output voltages of regulators are supplied to each load device and input to a representing-value decision logic circuit that is operated by a dedicated resident power supply. One cathode is provided per plasma channel, which cathode includes an electrode which is adjustable relative to the cathode housing in the direction of the plasma channel. Because data latches and output latches are not necessary, the driver of the present invention achieves significant reduction in the circuit components and chip size without compromising the display quality. The perspective image generator changes the first direction into a third direction based on the difference in position between the first and second perspective images, and generates an updated one, viewed in the third direction, of the first perspective image.