Patent US 6,979,839

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.