An active-type display device includes a plurality of video signal lines that are formed on a substrate, a plurality of pixels that are connected to the video signal lines and are operated by current signals, and a video signal driver that supplies video currents to the pixels via the video signal lines on the basis of data signals that are supplied from an external circuit. The video signal driver includes a plurality of DA units that sum up at least one of a plurality of gray-level reference currents, which are stored in constant current memory circuits, on the basis of the data signals, thereby executing conversion to the video current.