| 摘要 |
<p>The color light returning in the direction of the light valve is shut off through color light combining means, the color light entering from the back side of the light valve is shut off, thereby preventing occurrence of malfunction of the light valve, so that a sharp image is obtained. The constitution of the invention comprises a light source for emitting a white light in one direction, color light separating means for separating the white light from the light source into three color lights of red light, blue light and green light, modulating means including liquid crystal light valves for modulating the polarized lights contained in the luminous fluxes from the color light separating means, and producing a video image, color light combining means for combining the modulated luminous fluxes after being modulated by the modulating means, and projection optical means for projecting the combined luminous flux obtained by the color light combining means on a screen. A polarizer is disposed at the light exit side of the modulating means. A dichroic filter having characteristics for selectively passing and selectively reflecting the color lights from the modulating means is disposed between the color light combining means and the modulating means positioned on an optical path of at least one color light of the three color lights of the red light, blue light and green light. The quarter-wave plate has a plurality of quarter-wave plates, a first quarter-wave plate of the plurality of quarter-wave plates contacts the dichroic filter, and a second quarter-wave plate of the plurality of quarter-wave plates contacts the dichroic filter, and is disposed between the dichroic filter and the color light combining means. <IMAGE></p> |
