An electro-optical device having six image signal lines that are third
layer leads comprising the same layer as data lines. A lead which is
branched from one image signal line and crosses the other image signal
lines is a parallel connection of a first layer lead and a second layer
lead. The first layer lead comprises the same layer as the scanning lines
in a display region and the second layer lead comprises the same layer as
a barrier film of a thin film transistor (TFT) in the display region.
Although the first and second layer leads have high resistance alone, the
parallel connection can reduce resistance. In other portions, the second
layer lead is used alone to improve the design versatility. Thus, the
design versatility of peripheral circuits such as a sampling circuit in
an electro-optical device is improved and the lead resistance in the
peripheral circuit is reduced.