Calculated correlations between material parameters and electro-optical performance of twisted nematic displays

Computer calculations of the optical transmission of TN-LCDs as a function of the applied voltage are presented. In particular, the wavelength and angular dependence of half transmission voltages and sharpness of transmission curves are examined. Furthermore the lowest relaxation rates of the linearized dynamical equations, neglecting backflow effects are calculated. The dielectrical anisotropy and the elastic parameters are varied systematically in the calculations over ranges that actually occur in nematics. Although the results are too complex to be condensed in simple general statements they are helpfull in designing optimal nematic mixtures for a given display application.