5.4: A Defect Free Bistable C1 SSFLC Display

Abstract

A defect free, large memory angle, high contrast ratio and bistable C1 SSFLC display, which has potential for E-paper and Liquid Crystal on Silicon (LCoS) applications has been developed using 5 o oblique SiO deposition alignment. The electro-optical properties and bistability of this display have been investigated. Various aspects of defect control are also discussed.

P‐101: Eliminating Layer Undulation Textures in SSFLC Devices

“…Geometrically, a zigzag free C1 structure can be achieved with 5 o obliquely evaporated SiO alignment 7,8,9 . However, this device still generally shows some subtle defects 10,11 , such as those reported before, are seen also in the SmA phase. One defect we found in our SiO aligned cell is the pin defect (Figure 1), which is related to the spacers and the dust, and it looks like a meteor.…”

“…We eliminated this defect by mixing the spacers in the UV-curable glue instead of spraying spacers onto the entire substrate and properly controlling the etching condition. The pin defects are removed and the contrast ratio was improved significantly 10 . The textures of the cell before and after removing the spacers from the pixel region for both materials are also shown in Figure 1.…”

L‐7: Late‐News Paper: Bistable Ferroelectric Liquid Crystal Pretilt and Alignment Direction on Obliquely Deposited SiO2 Surfaces

“…Another important property of LC-surface interactions, especially for FLC alignment [3,4], is pretilt (Figure 2(b)). Molecular orientation at a surface can vary from perpendicular (90° pretilt) to parallel (0° pretilt).…”

“…It has been found that the high pretilt angle of obliquely deposited SiO X can be used to suppress C2 chevron formation in ferrroelectric liquid crystal (FLC) devices, thus eliminating zigzag defects [2]. Combined with the low threshold bistable switching of some FLCs on SiO X , this makes SiO X an attractive candidate for use in commercial devices [3,4].…”

Bistable FLCOS devices for doubled‐brightness micro‐projectors

“…True bistable switching is achieved with relatively few FLC/alignmentsurface combinations. In particular, obliquely deposited SiO X and SiO 2 alignment surfaces have been shown to produce low voltage bistable switching with some FLCs [5][6][7], making them good candidates for use in FLCOS devices. We utilize these alignment surfaces with newly developed FLC materials to make experimental bistable FLCOS devices.…”