Patent ID: 7479655

Claim:
A semiconductor device comprising: a substrate including a first region and a second region provided in the first region; a pixel provided in the second region, wherein the pixel contains a first pixel circuit including a first transistor, a second transistor, a gate signal line, a data signal line and a power source line, and a light emitting element electrically connected to the first pixel circuit; a test element group for testing the first transistor and the second transistor in the second region, wherein the test element group is provided in the first region outside of the second region; and at least one terminal provided outside of the first region, wherein the test element group includes a second pixel circuit, wherein, in the first pixel circuit, the first transistor includes a gate connected to the gate signal line, and a source and a drain of which one is electrically connected to the data signal line and the other is electrically connected to a gate of the second transistor, and the second transistor has a source and a drain of which one is electrically connected to the power source line and the other is electrically connected to the light emitting element, wherein at least one of first transistor and second transistor of the second pixel circuit is electrically connected to the terminal, and wherein a potential of a gate signal line of the second pixel circuit is fixed.