Patent ID: 8044895

Claim:
A display device comprising: a pixel including a first thin film transistor, a second thin film transistor, a third thin film transistor, a fourth thin film transistor, a first capacitor, a second capacitor and a light emitting element; a signal line; a first power source line; a second power source line; a third power source line, wherein one of a source and a drain of the first thin film transistor is electrically connected to the signal line and the other of the source and the drain of the first thin film transistor is electrically connected to a gate of the second thin film transistor, wherein one of a source and a drain of the second thin film transistor is electrically connected to the first power source line and the other of the source and the drain of the second thin film transistor is electrically connected to a first electrode of the light emitting element, wherein a second electrode of the light emitting element is electrically connected to the second power source line, wherein one of a source and a drain of the third thin film transistor is electrically connected to the first electrode of the light emitting element and the other of the third thin film transistor is directly connected to the third power source line, wherein the first capacitor is electrically connected in parallel to the light emitting element, wherein the second capacitor is located between one of the source and the drain of the second thin film transistor and the gate of the second thin film transistor, wherein the fourth thin film transistor is electrically connected in parallel to the second capacitor, wherein a gate of the third thin film transistor is electrically connected to a gate of the fourth thin film transistor, and wherein a potential of the second power source line is lower than that of the third power source line.