Liquid crystal display device
It is an object of the present invention to provide a liquid crystal display device which has a wide viewing angle and less color-shift depending on an angle at which a display screen is seen and can display an image favorably recognized both outdoors in sunlight and dark indoors (or outdoors at night). The liquid crystal display device includes a first portion where display is performed by transmission of light and a second portion where display is performed by reflection of light. Further, a liquid crystal layer includes a liquid crystal molecule which rotates parallel to an electrode plane when a potential difference is generated between two electrodes of a liquid crystal element provided below the liquid crystal layer.
1. A liquid crystal display device comprising:
a transistor over a substrate, the transistor comprising:
a semiconductor layer;
a gate insulating film over the semiconductor layer; and
a gate electrode over the gate insulating film;
a first insulating layer over the transistor;
a first wiring over the first insulating layer, the first wiring in contact with the semiconductor layer through an opening of the first insulating layer;
a second wiring over the first insulating layer;
a second insulating layer over the first wiring and the second wiring;
a common electrode over the second insulating layer, the common electrode electrically connected to the second wiring;
a third insulating layer over the common electrode;
a pixel electrode over the third insulating layer, the pixel electrode electrically connected to one of a source and a drain of the transistor;
a liquid crystal layer overlapping the pixel electrode and the common electrode,
wherein the first wiring and the second wiring comprise the same material, and
wherein the pixel electrode includes a slit.
2. The liquid crystal display device according to claim 1 , wherein the semiconductor layer comprises polycrystalline silicon.
3. The liquid crystal display device according to claim 1 , further comprising an FPC mechanically coupled to the substrate and electrically connected to the pixel electrode.
4. An electronic appliance comprising the liquid crystal display device according to claim 1 .
5. The liquid crystal display device according to claim 1 , wherein the gate electrode comprises molybdenum.
6. The liquid crystal display device according to claim 1 , wherein each of the common electrode and the pixel electrode comprises indium tin oxide.
7. A liquid crystal display device comprising:
a transistor over a substrate, the transistor comprising:
a semiconductor layer;
a gate electrode; and
a gate insulating film between the semiconductor layer and the gate electrode,
a first insulating layer over the transistor;
a first wiring over the first insulating layer, the first wiring in contact with the semiconductor layer through an opening of the first insulating layer;
a second wiring over the first insulating layer;
a second insulating layer over the first wiring and the second wiring;
a common electrode over the second insulating layer, the common electrode electrically connected to the second wiring;
a third insulating layer over the common electrode;
a pixel electrode over the third insulating layer, the pixel electrode electrically connected to one of a source and a drain of the transistor;
a liquid crystal layer overlapping the pixel electrode and the common electrode,
wherein the first wiring and the second wiring comprise the same material, and
wherein the pixel electrode includes a slit.
8. The liquid crystal display device according to claim 7 , wherein the semiconductor layer comprises polycrystalline silicon.
9. The liquid crystal display device according to claim 7 , further comprising an FPC mechanically coupled to the substrate and electrically connected to the pixel electrode.
10. An electronic appliance comprising the liquid crystal display device according to claim 7 .
11. The liquid crystal display device according to claim 7 , wherein the gate electrode comprises molybdenum.
12. The liquid crystal display device according to claim 7 , wherein each of the common electrode and the pixel electrode comprises indium tin oxide.
13. A liquid crystal display device comprising:
a transistor over a substrate, the transistor comprising:
a semiconductor layer;
a gate insulating film over the semiconductor layer; and
a gate electrode over the gate insulating film;
a first insulating layer over the transistor;
a first wiring over the first insulating layer, the first wiring in contact with the semiconductor layer through an opening of the first insulating layer;
a second wiring over the first insulating layer;
a second insulating layer over the first wiring and the second wiring;
a common electrode over the second insulating layer, the common electrode electrically connected to the second wiring;
a third insulating layer over the common electrode;
a pixel electrode over the third insulating layer, the pixel electrode electrically connected to one of a source and a drain of the transistor;
a liquid crystal layer overlapping the pixel electrode and the common electrode,
wherein the first wiring and the second wiring comprise the same material,
wherein the pixel electrode includes a slit, and
wherein the liquid crystal display device is configured to display an image by an FFS mode.
14. The liquid crystal display device according to claim 13 , wherein the semiconductor layer comprises polycrystalline silicon.
15. The liquid crystal display device according to claim 13 , further comprising an FPC mechanically coupled to the substrate and electrically connected to the pixel electrode.
16. An electronic appliance comprising the liquid crystal display device according to claim 13 .
17. The liquid crystal display device according to claim 13 , wherein the gate electrode comprises molybdenum.
18. The liquid crystal display device according to claim 13 , wherein each of the common electrode and the pixel electrode comprises indium tin oxide.