The present invention provides an active-matrix electro-optical device allowing
clear multi-gray-scale color display. In the electro-optical display according
to the present invention, a plurality of pixels included in a pixel portion have
a first and a second source signal lines, a first and a second gate signal lines,
and a power source supply line. Each of the pixels has a first TFT for switching,
a second TFT for switching, a TFT for driving and a light emitting element.
