An electro-optical driving device for providing a high-quality display that is free from non-uniformities. Subpixels 120a, 120b, and 120c are arranged at the respective intersections of 3m scanning lines 112 that extend in the X direction and n data lines 114 that extend in the Y direction. The subpixels 120a, 120b, and 120c are adjacent in the Y direction and are grouped together as a pixel 120 in a driving operation. In a first mode, the subpixels forming the one pixel are individually turned on and off in response to gray scale data indicating the gray scale of the pixel. In a second mode, the subpixels forming the one pixel are supplied with a common voltage in response to the gray scale data indicating the gray scale of the pixel. In this way, the signal supplied to the data lines is binary regardless of the first mode or the second mode.