Patent ID: 8723845

Claim:
A display device, having: a display region where (i) pixels arranged in a matrix manner and (ii) pixel TFT elements provided for the respective pixels, are provided; and a region on the periphery of the display region, in which region a driving circuit, including driving TFT elements formed monolithically with the pixel TFT elements, is provided, each of the driving TFT elements including a semiconductor layer, a gate electrode, a source electrode, and a drain electrode, the gate electrode being provided on a first surface of the semiconductor layer, and the source electrode and the drain electrode being provided on a second surface of the semiconductor layer, the second surface facing the first surface, one of the source electrode and the drain electrode being provided, in a region, so as to surround part of the other of the source electrode and the drain electrode, the one of the source electrode and the drain electrode being away, in the region, from the other by a constant distance, the driving circuit further including (i) a redundancy TFT element provided so as to have a channel width identical to those of the driving TFT elements, (ii) a first redundancy line, (iii) a second redundancy line, and (iv) a third redundancy line, the first redundancy line being provided, by electrically connecting to one of a plurality of first lines for supplying different first signals to the gate electrodes of the respective driving TFT elements, so as to supply, to a gate electrode of the redundancy TFT element, a first signal that is to be supplied via the one of the plurality of first lines electrically connected to the first redundancy line, the second redundancy line being provided, by electrically connecting to one of a plurality of second lines for supplying different second signals to the source electrodes of the respective driving TFT elements, so as to supply, to a source electrode of the redundancy TFT element, a second signal that is to be supplied via the one of the plurality of second lines electrically connected to the second redundancy line, and the third redundancy line being electrically connected to a drain electrode of the redundancy TFT element, and the third redundancy line being provided, by electrically connecting to one of a plurality of third lines, via which the different second signals are outputted from the drain electrodes of the respective driving TFT elements, so that a corresponding one of the different second signals, which is to be outputted from the drain electrode of the redundancy TFT element, is outputted from the one of the plurality of third lines electrically connected to the third redundancy line.