A wide-view twisted nematic liquid crystal cell with improved image quality obtained by decreasing γ-curve distortion

Wide-view (WV) film, which was introduced by Fuji Co., has been commercialized to block light leakage of twisted nematic (TN)-liquid crystal (LC) cells in a dark state when the viewing angles are in the off-axis direction. In this investigation, we designed an optical compensation structure of a TN-LC cell with an improved γ-curve, as well as a viewing angle property in the dark state. Basically, we used a pair of optical films consisting of a positive and a negative A-plate in order to avoid affecting the viewing angle property in the dark state. Then, we optimized the positive and negative A-plate to improve the viewing angle property in the gray levels by calculating polarization variations as a function of the optical axis and the retardation of the pair of the A-plates. From this calculation, we were able to show that the proposed normally white (NW) WV-TN cell exhibits wide viewing angle performance, including good γ-curve stability.