An object of the present invention is to provide a light emitting device
that is able to suppress power consumption while a balance of white light
is kept, without making a configuration of a power source circuit
complicated. A power source potential corresponding to each color of a
light emitting element is used as a higher electric potential of a video
signal and an electric potential of a power source line in the case that
a transistor for controlling a supply of electric current to the light
emitting element is a p-channel TFT. Conversely, a power source potential
corresponding to each color of a light emitting element is used as a
lower electric potential of a video signal and an electric potential of a
power source line in the case that a transistor for controlling a supply
of electric current to the light emitting element is an n-channel TFT.