Physical properties of new liquid-crystal mixtures and electrooptical performance in twisted nematic displays

Abstract

Complete sets of measurements are reported of the elastic, dielectric, optical, and viscous properties of new liquid-crystal mixtures for twisted nematic displays. Their optical and capacitive threshold voltages were shown to be identical and were used to determine the twist elastic constants k 22 . The splay (k 11 ) and bend (k 33 ) elastic constants were measured using a novel phase sensitive capacitance bridge, The new mixtures consist of nematic and isotropic components belonging to different chemical classes. Large mesomorphic temperature ranges (T c > 100° C), fast electrooptical response, 1.5-V operation, and 3-V 1:3 multiplexability could be achieved with different eutectic mixtures. Good agreement was found between material properties of physically and chemically different mixtures and their static and dynamic electrooptical performance in twisted nematic displays.