The 
ripple component superimposed on the drive power source Va applied to the source 
electrode of a 
light emission drive 
transistor Tr2 is extracted by a 
ripple component extraction circuit 14, and the 
ripple component is supplied to one input terminal of a 
voltage addition circuit 15. A data 
voltage Vdata transmitted via a data line is input to the other input terminal of the 
voltage addition circuit 15. Accordingly, in the voltage addition circuit 15, the ripple component extracted by the ripple component extraction circuit 14 is added to the data voltage Vdata treating the data voltage Vdata as the base. Its output is supplied to a scan selection 
transistor designated by reference character SW1 as Vgate, and the 
transistor Tr1 is turned on at an addressing time so that the Vgate is supplied to the gate of the 
light emission drive transistor Tr2. Thus, the gate-to-source voltage Vgs of the 
light emission drive transistor Tr2 represents an approximately constant value all the time regardless of timing of addressing. Therefore, a problem that 
intensity change occurs for each 
scan line so that the display quality of an image is considerably deteriorated can be avoided.