Patent ID: 8519392

Claim:
A light emitting device comprising: a pixel over a substrate, the pixel comprising: a light emitting element; a first line, a second line, a third line, and a fourth line; and a first transistor, a second transistor, a third transistor, and a fourth transistor, wherein a gate of the third transistor is electrically connected to the second line, one of source and drain of the third transistor is electrically connected to the first line, and the other of source and drain of the third transistor is electrically connected to one of source and drain of the fourth transistor, wherein a gate of the fourth transistor is electrically connected to the second line, and the other of source and drain of the fourth transistor is electrically connected to a gate of the first transistor, wherein one of source and drain of the first transistor is electrically connected to the other of source and drain of the third transistor, and the other of source and drain of the first transistor is electrically connected to the fourth line, and wherein a gate of the second transistor is electrically connected to the third line, one of source and drain of the second transistor is electrically connected to the one of source and drain of the first transistor, and the other of source and drain of the second transistor is electrically connected to the light emitting element.