Active matrix liquid-crystal display device having ITO signal lines and either a symmetric TFT structure or electrode and signal line edges with taper angles </=30 DEG

摘要

An active matrix type liquid-crystal display device wherein a plurality of gate wiring lines and drain wiring lines which cross perpendicularly to each other are laid on a first of two insulating substrates. The gate wiring lines and the drain wiring lines are electrically insulated from each other at areas where they crossover each other and thin-film transistors are respectively arranged near the individual crossover areas with their respective source electrodes connected to corresponding ones of transparent pixel electrodes disposed near the source electrodes, with their respective drain electrodes connected to the drain wiring lines, and with their respective gate electrodes connected to the gate wiring lines. The above structure, which includes the first insulating substrate, is covered with either only alignment layers or both protective insulating layers and alignment layers. Sets of transparent electrodes and alignment layers, each of the sets being opposite to a corresponding one of the transparent pixel electrodes, are disposed on a second of the two insulating substrates, the second insulating substrate being transparent and being located in opposition to the first insulating substrate. A liquid crystal is held between the two insulating substrates. The gate wiring lines as well as the drain wiring lines, and the transparent electrodes which are opposite to the wiring lines on the transparent insulating substrate are connected to liquid-crystal driver circuits which are provided outside the liquid-crystal display device. The improvement to the liquid crystal display device comprises the fact that the drain wiring lines, and the drain electrodes and the source electrodes of the thin-film transistors are formed of the same material as that of the transparent pixel electrodes, and that the transparent pixel electrodes are made thinner than the drain wiring parts.