Light Valves Enable 110-in. High-Definition Display

A team at NHK and Seikei University, both in Tokyo, has reported the development of a 110-in., color high-definition projection display that employs polymer-dispersed liquid crystal light valves. The researchers described the display in the Jan. 1 issue of Applied Optics.

The device features a light valve for each of the red, green and blue channels. Each light valve features nematic liquid crystal in a three-dimensional polymer matrix. Irradiating a boron-doped, hydrogenated amorphous silicon photoconductive film on the back side of the valve with the information to be projected orients the liquid crystal such that light reflected from the front of the valve is modulated to yield the desired image. No polarizing beamsplitter is required, so the technique does not suffer the optical losses of similar approaches that employ digital micromirror devices or other liquid crystal light valves.

The completed display yields a resolution of 810 TV lines and a luminous flux of 1900 to 2100 ANSI lm. Measured chromaticity coordinates nearly match the high-definition TV standard.