Patent ID: 7423295

Claim:
A light emitting device comprising: a substrate; first, second, third and fourth transistors provided over the substrate; a bank provided over at least the fourth transistor; and a light emitting layer provided beyond the bank so that the light emitting layer is provided in an opening, the light emitting layer connected with the fourth transistor, wherein drains of the second transistor and the third transistor are connected to each other, wherein the first transistor controls a video signal inputted to each gate of the second transistor and the third transistor, wherein sources of the third transistor and the fourth transistor are connected to each other, wherein the drains of the second transistor and the third transistor are connected to a gate of the fourth transistor, wherein the fourth transistor controls a current amount supplied to the light emitting layer according to each drain potential of the second transistor and the third transistor, and wherein a light emitted from the light emitting layer is outputted from a first side of the light emitting device though the substrate, and is outputted from a second side of the light emitting device opposite to the first side.