Display device

1. A display device comprising:

a substrate;

a display region having a pixel switch, a pixel electrode which is connected to the pixel switch, and a transparent common electrode formed over the substrate;

a peripheral region having a gate signal line which is connected to the pixel switch, and a common connection line which is connected to the transparent common electrode;

an insulating layer which is disposed on the gate signal line and the common connection line;

a conductive layer which is disposed on the insulating layer and crosses the gate signal line and the common connection line in the peripheral region;

a first semiconductor film which is disposed between the insulating layer and the conductive layer;

a second semiconductor film which is disposed between the insulating layer and the conductor layer and is separated from the first semiconductor film;

wherein the conductor layer is connected to the gate signal line via a pair of diodes;

wherein the gate signal line is arranged in the display region and the peripheral region, the common connection line is arranged in the peripheral region and is connected to the transparent common electrode in the peripheral region, and the transparent common electrode is arranged in the display region;

wherein the first semiconductor film overlaps, in plan view, a region where the gate signal line crosses the conductive layer; and

wherein the second semiconductor film overlaps, in plan view, a region where the common connection line crosses the conductive layer.

2. A display device according to claim 1 , wherein the first semiconductor film and the second semiconductor film each include a semiconductor film doped with an impurity.

3. A display device according to claim 2 ,

wherein the gate signal line extends both in the peripheral region and in the display region; and

wherein the common connection line extends in a frame region without being formed in the display region.

4. A display device according to claim 3 ,

wherein the first semiconductor film does not overlap with a wire other that the conductive layer and the gate signal line; and

wherein the second semiconductor film does not overlap with a wire other than the conductive layer and the common connection line.

5. A display device according to claim 3 ,

wherein the conductive layer is a ground wiring.

6. A display device according to claim 2 ,

wherein the conductive layer is a ground wiring.

7. A display device according to claim 1 , wherein the gate signal line extends both in the peripheral region and in the display region; and

wherein the common connection line extends in a frame region without being formed in the display region.

8. A display device according to claim 7 ,

wherein the first semiconductor film does not overlap with a wire other that the conductive layer and the gate signal line; and

wherein the second semiconductor film does not overlap with a wire other than the conductive layer and the common connection line.

9. A display device according to claim 7 ,

wherein the conductive layer is a ground wiring.

10. A display device according to claim 1 ,

wherein the first semiconductor film does not overlap with a wire other that the conductive layer and the gate signal line; and

wherein the second semiconductor film does not overlap with a wire other than the conductive layer and the common connection line.

11. A display device according to claim 10 ,

wherein the conductive layer is a ground wiring.

12. A display device according to claim 1 ,

wherein the conductive layer is a ground wiring.

13. A display device according to claim 1 ,

wherein each of the pair of diodes is a diode-connected thin film transistor; and

wherein a gate electrode and a source electrode of each of the pair of diodes are connected to the conductive layer.

14. A display device according to claim 1 ,

wherein a length of the common connection line is shorter than a length of the gate signal line; and

wherein the common connection line isn't arranged in the display region.