The present invention provides an image display device that reduces variations
in brightness of the light emitting elements included in the device due to a voltage
drop on the power source line of the device and TFT threshold voltage variations
and displays good quality images. The image display device is equipped with a pixel
circuit voltage detecting means to selectively output a voltage internal to a pixel
circuit included in each of a plurality of pixels of the device to a signal line
to which the pixel circuit connects. Its drive circuit is equipped with a voltage
addition means to add the signal line voltage and a signal voltage corresponding
to image data to be displayed and output a sum voltage to the signal line again.