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Complete suppression of color shift in in-plane switching mode liquid crystal displays (LCDs) has been realized. The LCDs have a multidomain structure obtained by unidirectional rubbing and use of zigzag electrodes. The design concept and performance of the devices are described in this paper.

Color shift and gray scale reversal for very large viewing angles are analyzed theoretically for in-plane switching. It follows that the color shift depends on the change of the effective birefringence dΔn, whereas gray scale reversal depends on the effective angle between the polarizers and the liquid-crystal director angle. Experimental results confirmed the theory that small gray levels result in a larger color shift. Likewise, the viewing angles in which a gray scale reversal occurs, correlate with the theory. To counter these drawbacks, two multidomain structures are proposed, neither of which requires additional orientation processes. With these multidomain structures, color shift was suppressed and no gray scale reversal was observed. However, the multidomain structures reduce maximum transmission, the extent of which depends on the type and design of the structure.

Unusual characteristics of the voltage-holding ratio were found when using in-plane switching of homogeneously oriented nematic liquid crystals. Even when employing liquid crystals with much lower resistivity than is applicable to the conventional active matrix driving technique, voltage-holding ratio characteristics were higher than those in conventional electric fields applied along the direction perpendicular to the substrate plane. The unusual holding ratio characteristics were attributed to the electric field direction being approximately parallel to the substrate plane.

We present new analytical tools able to predict the averaged behavior of fronts spreading through self-similar spatial systems starting from reaction-diffusion equations. The averaged speed for these fronts is predicted and compared with the predictions from a more general equation (proposed in a previous work of ours) and simulations. We focus here on two fractals, the Sierpinski gasket (SG) and the Koch curve (KC), for two reasons, i.e. i) they are widely known structures and ii) they are deterministic fractals, so the analytical study of them turns out to be more intuitive. These structures, despite their simplicity, let us observe several characteristics of fractal fronts. Finally, we discuss the usefulness and limitations of our approach.