Abstract Fringe-field switching (FFS) mode utilizes mixed concept of phase retardation and polarization rotation effects for light modulation so that the light efficiency is dependent on electrode position. In addition, the liquid crystal (LC) director does not rotate enough above center of electrodes when using a LC with positive dielectric anisotropy [1-3]. Consequently, the light efficiency of the conventional FFS mode especially with positive LC is much lower than that of twisted nematic (TN) mode. However, the reduction of electrode width and distance between them to 1 µ and 1.5µ in the FFS mode greatly improves light efficiency (0.79 -> 0.90) and response time (31 ms -> 16ms) compared to the conventional structure according to our calculations, and thus the new FFS cell reaches the same light efficiency as that of the TN mode. Further, in the new FFS mode, the light modulation does occur purely by polarization rotation effect so that the wavelength dispersion and degree of color shift is reduced.

References [1] S. H. Lee, S. L. Lee and H. Y. Kim, Electro-optic characteristics and switching principle of a nematic liquid crystal cell controlled by fringe-field switching, Appl. Phys. Lett. 73, 2881 (1998). [2] S. H. Jung, H. Y. Kim, M. H. Lee, J. M. Rhee and S. H. Lee, Cell gap-dependent transmission characteristics of a fringe-electric field-driven homogeneously aligned liquid crystal cell, for a liquid crystal with negative dielectric anisotropy, Liquid Crystals. 32, 267 (2005). [3] S. J. Kim, H. Y. Kim, S. H. Lee, Y. K. Lee, K. C. Park and J. Jang, Cell Gap-Dependent transmittance Characteristic in a Fringe Field-Driven Homogeneously Aligned Liquid Crystal Cell with Positive Dielectric Anisotropy, Jap. J. Appl. Phys. 44, 6581 (2005).