Patent ID: 7791012

Claim:
A semiconductor device comprising: a photoelectric conversion element having a square plane; a current mirror circuit including a reference thin film transistor and a plurality of output thin film transistors, the current mirror circuit amplifying an output of the photoelectric conversion element; a high-potential electrode arranged at a first side of the photoelectric conversion element; and a low-potential electrode arranged at a second side of the photoelectric conversion element; wherein both the reference thin film transistor and the plurality of output thin film transistors are n-type thin film transistors, wherein one of source and drain electrodes of the reference thin film transistor is electrically connected to the high-potential electrode through the photoelectric conversion element, wherein one of source and drain electrodes of each of the plurality of output thin film transistors is electrically connected to the high-potential electrode, wherein the other of the source and drain electrodes of the reference thin film transistor is electrically connected to the low-potential electrode, wherein the other of the source and drain electrodes of each of the plurality of output thin film transistors is electrically connected to the low-potential electrode, wherein the plurality of output thin film transistors are provided in an L-shape region extending from a vicinity of the high-potential electrode to a vicinity of the low-potential electrode along the first side and the second side, and wherein the reference thin film transistor is provided in the vicinity of the low-potential electrode.