The present invention provides an optical compensation structure for improving the gray-level of the vertical alignment mode liquid crystal 4 domain. Such an optical compensation structure to improve the gray level of the four-domain vertical alignment liquid crystal mode of the present invention is excellent contrast ratio (contrast ratio), wide viewing angle characteristics, the optical performance of the implement side light leakage dark state (dark state) without as one will remain to improve the gray level (gray-level) of the distortion in terms of viewing angle.
The optical compensation structure to improve the gray level of the four-domain vertical alignment liquid crystal mode in accordance with the present invention by applying a voltage, and control the transmission of external light, the four-way to knock the liquid crystal cell 20 composed of a liquid crystal and a vertical alignment; The upper side polarizing plate 30 disposed on the upper side of the vertical alignment liquid crystal cell (20) and; Lower polarizer 40 is arranged on a lower side of the vertical alignment liquid crystal cell (20) and; The biaxial film (biaxial film) (50) disposed between the vertical alignment liquid crystal cell 20 and the upper side polarizing plate 30 and; Wherein arranged between the vertical alignment liquid crystal cell 20 and the lower polarizing plate 40, the optical axis comprising: an optical film having a negative C- plate 60 of a uniaxial birefringent medium in a perpendicular state to the surface of the film, the vertically aligned liquid crystal cell 20 and the upper side polarizing plate 30 and between the upper optical compensation film 70 and the lower optically compensating film (80) between the vertically aligned liquid crystal cell 20 and the lower polarizing plate 40, respectively, characterized in that for positioning.