Projectors with Liquid Crystal Light Valves
Ernst H. Lueder, Peter Knoll, Seung Hee Lee · 2022
Liquid crystal displays (LCDs) can be used as the image source in a projector. Lenses project this image onto a screen. An LCD in such a projector is called a light valve, or more to the point, a Liquid Crystal Light Valve (LCLV). This chapter focuses on the various forms of LCLVs. A colour projector may use one, two or three LCDs as light valves; they may be transmissive or reflective and may exhibit a variety of implementations such as untwisted, especially vertically aligned, or twisted nematic LCDs, PDLCDs, FLCDs, or most promising, LCOS devices. The chapter examines the most important architectures of projectors that use LCLVs. After having passed the LCDs, the three colours are recombined in a dichroic colour combining cube or by separate dichroic mirrors and are then projected onto a screen. This one lamp, one projection lens, three light valve system is the most commonly used.