Cell Thickness Dependence on Electric Optical Property of Reverse Mode Liquid Crystal Display

Abstract

Electro-optical properties have been investigated as a function of cell thickness in a reverse mode cell which shows a transparent off-state and a light scattering on-state. The cell is prepared by using a nematic liquid crystal (LC) and a photo-reactive mesogen. A driving voltage and a contrast ratio of this device strongly depend on a cell thickness and there is a trade-off relationship between them. We have reported that the cell thickness dependence in the reverse mode LC cell is different from that in a normal scattering mode polymer dispersed LC with normal scattering mode. The turbidity in voltage on-state is investigated as a function of cell thickness and a simple model with polymer rich and poor layers in the cell is proposed to analyze scattering properties. The low driving voltage is compatible with the high contrast ratio by control the cell thickness and the morphology of polymer network.