When a resistance load inverter is used to control lighting/non-lighting
of a pixel, in accordance with characteristic variations of a transistor
forming the resistance load inverter, variations occur in light emission
of each pixel. As an inverter in a pixel, an N channel transistor and a P
channel transistor are used to apply a CMOS inverter. Even when
characteristics of the transistor forming the CMOS inverter vary and
inverter transfer characteristics vary, there is little effect on
controlling lighting/non-lighting of the pixel, therefore, light emission
variations of each pixel can be eliminated. Further, a signal potential
of a scan line is used as one power source of a potential of the
inverter, therefore, an aperture ratio of the pixel can be increased.