Super Twisted Nematic STN

The simple multiplexed LCD has the advantage of a simple electrode configuration as illustrated in Fig. 4.3.1. Two glass plates with striped transparent electrodes 

Accordingly, D-STN-LCDs fabricated according to these conditions (with micro colour filters on each pixel) were used to make multi-colour LCD displays. It should be noted that a film-compensated STN-LCD using optical retarder films instead of the STN-LCD liquid-crystal compensator in the D-STN-LCD can also be used. 

The principle of the IPS (In-Plane Switching) mode is shown in Fig. 4.4.1. In typical LCDs, both substrates have electrodes and the direction of the electric field is perpendicular to the substrates. In the IPS mode, however, only one substrate has electrodes and the electric field runs parallel to the substrates. The molecular long axes of the liquid crystal molecules are thus parallel to the substrates whether an electric field is or is not applied. In other words, the switching of the liquid crystal molecules by the electric field remains within a single plane. 

The strong merit of operation in the ISP mode is its wide viewing angle. Kiefer et at. proposed this mode in 1992 [1] and, in 1995, Oh-e et al. presented a wide viewing angle TFT-LCD in which the IPS mode was applied [2]. 

1 Viewing angle dependence of the contrast ratio of the VA mode (a) TN mode (b) VA mode (c) VA mode with two retardation films (d) MVA mode [1]. 

O 2005 K Jiki Takatob, Masald Hasegawa, Mitsuhiro Koden, Nobi uld Itoh, Ray Has wa and Ma anoii Sakamoto 

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The first TN-LCD were simple, directly addressed segment displays as still used, e. g., for wrist watches. When attempts were made to increase the information content of the displays by time-sequential addressing in rows and lines (multiplexing) the limits of the TN cell were soon met. At higher multiplex ratios [14] contrast loss occurred, because of ever shorter addressing times. The development of the super-twisted nematic (STN) cell in 1984 [15] pushed the practicable limit to higher multiplex ratios, but it did not lead to a general solution of the problem. 

In LCDs various LC modes of operation are applied like twisted nematic (TN) [5], super twisted nematic (STN)[6], vertically aligned nematic (VAN) [7,8], optically compensated birefringence (OCB) [9] and in plane switching (IPS) [10-12]. The LC mode used depends on the demands of a specific application, like the viewing angle, power consumption and manufacturing cost. 

Super-twisted nematic (STN) Retardation 2 As > 0 Twist (> 90 °) Perpendicular to substrate surface... 

Silver halide photosensitive materials for photographic purposes were the main products of FUJIFILM, and in the 1990s, future market projections did not hint any decline. Thus, silver hahde photosensitive materials were mainstream materials in our company. As a result, less than 1 % of researchers developed optical films for LCDs. Our team had developed and commercialized an optical compensation film for super twisted nematic (STN) LCDs since 1987, but we were greatly defeated by competitions that had products with better performance, but we were greatly defeated by competitors that had products with better performance. Thus, in 1992 we faced the closing down of our unit. 

Fig. 7.12 (a) Photo-aligned LCP retarder integrated onto the substrate of a photo-aligned LCD. (b) Black-white super twisted nematic (STN)-LCD with integrated color compensating a-plate... 

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