Liquid crystal display devices have problems such as a low contrast, a slow response speed, a narrow viewing angle and the like. For solving these problems, various techniques have been proposed.
For example, in a method called a Vertical Alignment (VA) mode, liquid crystal molecules of liquid crystals having a negative dielectric anisotropy are aligned in a vertical direction by use of a vertical alignment film in a case where voltage is not applied to the liquid crystals. As a result, a black display is carried out. Meanwhile, in a case where voltage is applied to the liquid crystals, the liquid crystal molecules are aligned in a horizontal direction. As a result, a white display is carried out. In this way, in the VA mode, when no voltage is applied, the liquid crystal molecules are vertically aligned. Accordingly, it is possible to obtain a display having little light leakage, a good black display quality, and a high contrast. Further, as compared to a TN (Twisted Nematic) mode, the liquid crystal molecules are arranged in a simpler manner because the liquid crystal molecules are not intricately twisted. Accordingly, when voltage is applied, a time for forming a state where the liquid crystal molecules are twisted is short, that is, a response speed is fast. Therefore, this VA mode has characteristics that are excellent in contrast and responsiveness.
Meanwhile, as a technique for widening a viewing angle, for example, a method of driving liquid crystals by use of a Multi-Domain design has been proposed. In the Multi-Domain design, one picture element region is divided into a plurality of sectional parts and liquid crystal molecules in each sectional part are aligned in a direction that is different for each sectional part. In this mode, in each picture element region, liquid crystal molecules aligned in different directions are present. Accordingly, a view is not limited in a specific direction. Therefore, a viewing angle can be widened.
Furthermore, in recent years, a technique called MVA (Multi-domain Vertical Alignment) in which the VA mode and the Multi-Domain design are combined has been proposed.
In an MVA liquid crystal display devices, alignment dividing means (a protrusion or a cutout section of an electrode) is formed also in an area relevant to display. Therefore, an effective display area tends to be smaller. This causes a problem such that, if the effective display area is ensured, it becomes difficult to provide a large storage capacitance.
Furthermore, in recent years, a distance between a picture element electrode and each signal line has become shorter (or an overlap amount of the picture element electrode and each signal line has become larger) due to demands for a higher aperture ratio and dot size reduction caused by an increased fineness). Therefore, a parasitic capacitance (Csd) between a picture element electrode and a data line tends to be larger with respect to a total pixel capacitance. In a case where the parasitic capacitance (Csd) between the picture element electrode and the data line becomes lager as described above, there arises a problem of deterioration in display quality, such as shadowing, uneven display within a panel plane, and the like.
In order to solve such problems, Patent Literature 1 discloses a technique in which, as shown in FIG. 14, a shield electrode 88 is provided on a protective film 180 above a data line 171 so that a parasitic capacitance (Csd) between a picture element electrode 190 and the data line 171 is reduced.
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USPTO Backgrounds