Based on Ericksen-Leslie's elastic theory and dynamic theory, the responsive time parameter of the in-plane switching liquid crystal displays is analyzed, the chiral-planar alignment is introduced into this mode, and the dynamic equation of the director is given. The relation of the responding time and the twist angle is obtained by calculating the instantaneous distribution of the director in this mode. The computational result demonstrates that there is a short responding time in IPS-Chiral-Planar liquid crystal cell with a certain twist angle.

In the supertwisted nematic-liquid crystal display (STN-LCD), the director of liquid crystal is determined by the tilt angle θ and the twist angle φ. The ordinary differential equations and the boundary conditions satisfied by θ,φ and the electric potential U are obtained, based upon the continuum theory of liquid crystals. Solving two-point boundary problem of the ordinary differential equations by means of the relaxation method, dependence of the optical threshold voltage on the anchoring strength is calculated.