Uniform Lying Helix of Cholesteric Liquid Crystals Aligned by means of Slit Coater Method with Electric Treatment

Abstract

SUMMARYA Uniform Lying Helix (ULH) liquid crystal device (LCD) fabricated by utilizing the characteristics of shear flow alignment as well as dielectric anisotropy was demonstrated. Cholesteric liquid crystals with a short helical pitch can exhibit an electric field-induced tilt. These experimental results indicate that it is possible to realize a high-speed response flexible LCD using plastic substrates. key words: uniform lying helix mode, flexible LCD, slit coater, short-pitch cholesteric liquid crystals

Review on polymer-stabilized short-pitch cholesteric liquid crystal displays

“…Unlike BPLC and USH modes, ULH mode needs special treatment to obtain uniform alignment pattern. A variety of methods involving combinations of electrical, mechanical or thermal treatment [70][71][72][73], periodic anchoring [77][78][79][80][81][82], electro-hydrodynamic effects [83,84], BP-ULH transition [38,85,86], tri-electrodes configuration [87] and slit coater [88] have been proposed. In table 1, we list several alignment approaches to obtain uniform ULH pattern.…”

“…Yes [115] Yes [36] No Alignment Not necessary Simple alignment procedure [38] Complicated alignment procedure [73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88] Charging issue…”

Study of Liquid Crystal Alignment Using Slit Coater under Different Application Velocities

“…Prof. Fujikake's group has demonstrated flexible LCDs that use polymer-wall technologies [2], and bendable LCDs have been realized using polyimide substrates [3]. Recently, the slit coater method was devised as a novel fabrication process for flexible LCDs [4][5][6][7][8][9]. The advantage of the slit coater method is that an alignment film and its thermal coating process are unnecessary.…”

“…The advantage of the slit coater method is that an alignment film and its thermal coating process are unnecessary. Twisted nematic (TN) mode LCDs, inplane switching (IPS) mode LCDs, and uniform lying helix (ULH) mode LCDs fabricated by the slit coater method have been demonstrated [5,9], and the surface anchoring energy has been surveyed [6,7]. However, the optimal fabrication conditions of the slit coating of LC materials has not yet been investigated.…”