Patent ID: 8780018

Claim:
A light emitting device comprising: a signal line; a power source line; a light emitting element comprising a light emitting layer; a first transistor; a second transistor; a third transistor; a fourth transistor; a first insulating layer over a gate electrode of the second transistor; a conductive layer under a counter electrode of the light emitting element; and a second insulating layer interposed between the first insulating layer and the counter electrode of the light emitting element, wherein a gate electrode of the third transistor and a gate electrode of the fourth transistor are connected with each other, wherein one of a source and a drain of the third transistor and one of a source and a drain of the fourth transistor are connected with one of a source and a drain of the first transistor, wherein the other of a source and a drain of the third transistor is connected with the signal line, wherein the other of a source and a drain of the fourth transistor is connected with a gate electrode of the first transistor, wherein the other of a source and a drain of the first transistor is connected with the power source line, and wherein one of a source and a drain of the second transistor is directly connected with a pixel electrode of the light emitting element.