<title>Addressing factors for polymer-dispersed liquid-crystal displays</title>

Abstract

Suitable addressing methods for polymer dispersed liquid crystal (PDLC) displays are dependent upon both the type of display and the PDLC properties. Video displays require fast frame rates, high resolution, and gray scale. The addressing method depends upon PDLC properties such as threshold voltage, operating voltages, response times, resistivity, and hysteresis effects. the properties of PDLC films which are formed by ultraviolet (UV) polymerization of LC/monomer solutions depend upon their formation conditions. The threshold and operating voltages, contrast ratio and response times are affected by formation factors including the UV intensity, temperature, LC concentration, LC composition, field pre- alignment conditions, cell thickness, and droplet shape. The PDLC resistivity and hysteresis properties are more difficult to control, and can strongly affect the light throughput, response times, and gray scale of video displays. Apparent limitations from these properties can be overcome by utilizing pulse mode addressing factors pertinent for active matrix and photoactivated light valve PDLC displays.