Patent ID: 8653541

Claim:
A semiconductor device including a plurality of circuits and a plurality of light-emitting elements, where the circuit includes a power line which extends in a single direction to which a power potential is provided, a transistor for controlling a current of an EL element, and a gate electrode layer configured to form a channel of the transistor, wherein the transistor having a semiconductor layer, wherein the semiconductor layer includes: a first contact pad; a first part that is connected to the first contact pad and that extends along the power line; a second part that extends from the first part at a right angle; and a second contact pad where the first part and the second part are arranged between the second contact pad and the first contact pad, wherein the first contact pad electrically connects to the power line, wherein the gate electrode layer has a rectangle projecting part in the direction of the first part, wherein the rectangle projecting part of the gate electrode layer has a first side parallel to the extending direction of the first part, wherein a part that is not projecting at the gate electrode layer has a second side parallel to the first side and next to a side of the first part, wherein the second part intersects with the first side by sandwiching the gate electrode layer and an insulating layer, wherein the first side does not face any one of sides of the first contact pad, and wherein the semiconductor layer includes a third part that extends from the second part along the power line, and wherein the second contact pad abuts on an end of the third part.