The brightness and contrast ratio of bistable twisted nematic displays are studied using the parameter space approach. By plotting the contrast ratio as a function of the twist angle and birefringence of the display, regions where the bistable twisted nematic display shows the best contrast ratio are clearly shown. We also studied the switching mechanisms of such displays.

Twisted homogeneously planar-aligned nematic liquid-crystal cells are cooled into the smectic- A phase. The expected defective structure does not form. Instead the cells still show good optical-guiding characteristics. Exploration of the cells using a half-leaky guided-mode arrangement reveals that the liquid-crystal phase separates into three or more regions. Adjacent to both the upper and low...

This paper presents two fundamental enhancements in a hybrid audio signal model consisting of sinusoidal, transient, and noise (STN) components. The first enhancement involves a novel application of a perceptual metric for optimal time segmentation for the analysis of transients. In particular, Moore and Glasberg’s model of partial loudness is modified for use with general signals and then inte...

A state of matter in which molecules show a long-range orientational order and no positional order is called a nematic liquid crystal. The best known and most widely used (for example, in modern displays) is the uniaxial nematic, with the rod-like molecules aligned along a single axis, called the director. When the molecules are chiral, the director twists in space, drawing a right-angle helico...

The 4'-n-alkyl-4-cyanobiphenyls and 4'-n-alkoxy-4-cyanobiphenyls provide colourless liquid crystal phases which are chemically and photochemically stable. In many cases, the mesophases are produced at quite low temperatures, and indeed two members of the n-alkyl series are nematic at room temperature. Eutectic mixtures prepared from members of the two series give wide nematic ranges, e. g., fro...

A three-terminal bistable twisted nematic liquid crystal display has been demonstrated. This display makes use of a combination of strong in-plane electric fields and vertical electric field for switching between the f and the f1p twist states. The lifetimes of the two bistable twist states are infinite, which is a significant improvement over conventional bistable twisted nematic displays. © 2...

To control viewing angle, various methods have been introduced by many LC display researchers [1-3]. Almost, however, they require side cost due to additional optical components. In this letter, as another merit of bistable nematic display, we present viewing angle control liquid crystal display using two stable states, splay and 180 ̊-twist at π cell with 3-terminal electrodes. Splay state of n...

A nematic elastomer film with a 90 o twist orientation between the top and bottom surfaces is prepared by chiral imprinting methods. The reactive achiral nematic monomers and crosslinkers are photopolymerized in the presence of a controlled amount of unreactive chiral dopant. The elastomer films possess a 90 o twist orientation even after the removal of the chiral dopant. The films exhibit an e...

Mueller calculus is employed to find the conditions that govern linear polarization preservation and the linear to circular polarization transformation in a general twisted nematic LC cell. The results are applied to the design of both transmittive and reflective twisted nematic LCDs. New optimized optical modes are reported. This method provides a clear physical interpretation of all LCD modes...

Mueller calculus is employed to find the conditions that govern linear polarization preservation and the linear to circular polarization transformation in a general twisted nematic LC cell. The results are applied to the design of both transmittive and reflective twisted nematic LCDs. New optimized optical modes are reported. This method provides a clear physical interpretation of all LCD modes...