Optical approach to improve the γ curve in a vertical-alignment liquid-crystal cell

In this Letter, we propose an optical configuration of a four-domain vertical-alignment (VA) liquid-crystal (LC) cell, which can improve the γ-curve distortion by using a pair of patterned A plates, without any change in cell structure. In order to find the optimal parameter value of the patterned A film, we calculated the polarization difference between the normal direction and the all-viewing direction as functions of the optical axes and the retardation (Δnd) under the voltage applied state. Based on the calculated results, the proposed LC cell showed an improvement in γ-curve distortion of more than 80% in each oblique viewing angle compared to a conventional wide-view VA LC cell, without any loss of optical performance in the dark state.