| 摘要 |
<p>This reflection projection system having a liquid-crystal light valve uses a polarising beam splitter (16) to reflect the light coming from a high-intensity arc lamp (10) to a liquid-crystal light valve (34) which is controlled by an image generator (36). The light reflected by the liquid-crystal light valve is sent through the polarising beam splitter (16) to a projection lens (38) and projected onto a screen. Spurious (parasitic) images of the arc-lamp source and reduction in contrast are caused by light reflected by the surfaces of the lens elements, on return, to the liquid-crystal light valve and subsequently reflected back through the lens. The spurious images and the reduction in contrast are eliminated by interposing a wide-band quarter-wave plate between the lens and the polarising beam splitter. Use for increasing the contrast and for eliminating "ghosts" in a projection system having a light valve. <IMAGE></p> |
