Computer Simulation Of Viewing Angle Characteristics Of Liquid Crystal Display Mode

Characteristics of optics and dynamics of liquid crystal displays (LCDs) are studied in this thesis. Basing on super twisted nematic (STN) and chiral-homeotropic (ChH) LCDs, the performance of the LCDs is improved after optimization.Basing on the continuum theory of liquid crystal, a new finite-difference iterative method is proposed to calculate the distribution of liquid crystal directors under an applied voltage. A new 2X2 extended Jones matrix is introduced to calculate the lightwave transmission of a liquid crystal cell and the dynamic parameter space method is also studied. The formulas of quantity and qualitative analysis of dynamic response of LCD are obtained after the dynamic response properties of liquid crystal cell are analyzed in detail.In the study on STN-LCD, double films compensated STN-LCD is introduced to eliminate the color at the off-state in this paper. Using 2X2 extended Jones matrix, we have optimized six parameters, the orientation for optical axes of polaroids and compensating films and the optical retardation of two compensating films, and get the double films compensated STN-LCD with wide viewing angle, weak color dispersion and black-white display.In this thesis, the ChH-LCD is also studied in order to resolve the problems of color dispersion and narrow viewing angle of vertical LCD. By optimization, we have obtained the transmissive and reflective LCD with full colors in calculation. Comparing with vertical LCD, the ChH-LCD has many virtues, such as weak color dispersion and wide viewing angle. The ChH-LCD with a positive compensated film is also studied, and the transmissive and reflective ChH-LCDs are optimized using dynamic parameter space method. We optimize three parameters, the thickness and birefringence product, the liquid crystal twist angle and the angle between the input director and the polarizer. After optimization, the ChH-LCD has many virtues, such as the characteristic of weak color dispersion, wide viewing angle, high contrast ratio, and fast response. By optimization, the reflective ChH-LCD (RChH-LCD) has the characteristic of weak color dispersion, low operation voltage, high contrast ratio, and fast response.