Twisted-nematic liquid-crystal displays with small grayscale inversion and wide viewing angle

This work proposes a twisted-nematic liquid-crystal display (TN-LCD) with a small grayscale inversion and wide viewing angle. The electro-optical properties of a tilted TN cell are studied to develop the proposed TN-LCD. Calculations reveal that when the applied voltage exceeds a critical voltage, the effective optical property of the tilted TN cell is optically uniaxial with the effective optical axis parallel to the bisector of the twist angle. This bisector effect is used to improve the grayscale inversion of TN-LCDs. A viewing angle of over the entire 80° viewing cone of the proposed TN-LCD is also demonstrated theoretically and experimentally.