Design and fabrication of a projection display using optically addressed polymer-dispersed liquid crystal light valves

Abstract

A prototype projection display consisting of optically addressed polymer-dispersed liquid crystal (PDLC) light valves and a Schlieren optics is designed, built, and evaluated. This projection display, which controls light by a scattering effect in the PDLC film, can be configured without requiring a polarizer and can create a brighter highdefinition picture display with which high optical efficiency is possible. The relationship between the contrast ratio and the optical efficiency of a Schlieren projection system is discussed. To design a projection display with both high brightness and a high contrast ratio, the scattering characteristics of a reflection-mode PDLC cell is evaluated and the optical efficiency of the total projection system is studied using a simple model with perfect diffusion of a light source. Using these results, we design and prototype PDLC light valves for a full-color display and construct a projection display. We succeed in displaying pictures with a contrast ratio of 80:1 and a brightness greater than 1800 ANSI lumens.

Monodisperse PDLC composites generated by use of polyvinyl alcohol boric acid as matrix

“…Polymer dispersed liquid crystal (PDLC) composites are a quite new class of materials which combine the lm forming ability and mechanical strength of polymers with unique electrooptical properties of liquid crystals (LC), making them suitable for a large range of opto-electronic applications in different domains, from electronics to biomedical devices. [1][2][3][4][5][6] The PDLC preparation consists of liquid crystal dispersion as micrometric droplets into a carrying matrix, to create a light modulating layer. 6 The optical modes of liquid crystal droplets are different from the ones in isotropic compounds, due to LC birefringence and specic conguration of the director eld within the droplet, which is a consequence of physical interaction between liquid crystal and matrix.…”

Chitosan as matrix for bio-polymer dispersed liquid crystal systems

“…Starting with projection displays (Kikuchi, Fujii, Kawakita, Fujikake, & Takizawa, 2000), smart windows (Liu et al, 2011), or holographic systems (Su, Chu, Chang, & Hsiao, 2011), studies on PDLC systems are continuing at present, the newest ones being directed to bring the use of the PDLC systems to bio-applications, e.g. smart food packaging (Perju, Marin, Grigoras, & Bruma, 2011) or tunable artificial iris modulating light intensity through human eyes for assisting patients of aniridia (Hsu, Lu, Huang, & Shih, 2011).…”