Bistable chiral-splay nematic liquid crystal device using horizontal switching

Abstract

The bistability in a chiral-splay nematic liquid crystal cell, which is obtained by adding a chiral additive to a splay cell, is proposed. In this letter, we describe a horizontal way of switching between the two states of the bistable chiral-splay cell, one state being characterized by a nontwisted director field with splay, the second state showing a director-field with 180° twist. The optimization of the various parameters of the device is described.

Dual mode operation of bistable chiral splay nematic liquid crystal cell using horizontal switching for dynamic operation

“…When an adequate vertical electric field is applied and removed, the splay state is changed into a -twist state via a bend state. 6 Because the splay and -twist states are topologically inequivalent each other, they have long retention time by doping an adequate ratio of a chiral dopant. 6,8 Also, the -twist state returns back to the initial splay state by using a horizontal electric field.…”

“…6 Because the splay and -twist states are topologically inequivalent each other, they have long retention time by doping an adequate ratio of a chiral dopant. 6,8 Also, the -twist state returns back to the initial splay state by using a horizontal electric field. 6 In order to verify that the proposed dual mode LCD operates as both the dynamic and memory modes, a LC cell was fabricated with three electrodes structure for applying vertical and horizontal electric fields, as shown in Fig.…”

“…3,5 The latter mode uses two LC textures of splay and twist and shows superior retention times in the two stable states. 6,8 However, because the LC textures used for the dynamic and memory modes are different, the pixel of the prototype dual mode LCD should be divided into two subpixels. The pixel division causes the decrease in the aperture ratio and the resolution of the LCD.…”

Optical multi-stability of bimesogenic cholesteric liquid crystal

“…CLCs have many merits, such as low power consumption due to their bistability [1][2][3][4][5][6], simple LC cell structure, and enhanced brightness. They have been used mainly for outdoor reflective type displays [7][8][9][10]. Furthermore, the image quality of CLC displays in comparison to other reflective LC displays is excellent in terms of viewing angle and color due to Bragg reflection.…”

Liquid Crystal Modes for Display Applications

“…그 이외에 액정의 blue phase, [20,21] ferroelectric [22] 액정을 이용한 모드 들도 개발되었지만, 복잡한 제조 공정 및 구동 방법으로 인 해 아직까지는 상용화 되지 못하고 있다. 전력소모를 최소화 하여 e-book 등에의 응용에 적합한 memory mode, [23] dynamic mode와 memory mode를 스위칭하여 동영상을 디스플레이할 수 있으면서도 전력소모를 최소화할 수 있는 dual mode [24,25] 에 대한 연구도 활발히 진행되고 있다. 본 논문에서는 가장 널리 사용되고 있는 VA 모드 및 IPS 모드에 대한 기술을 중 심으로 살펴보고자 한다.…”