| 摘要 |
<p>PURPOSE:To suppress a decrease in the quantity of light transmitted through a projection optical system and to obtain a bright display image by projecting visible light which is polarized by a polarization beam splitter and a lambda/4-wavelength plate upon a liquid crystal display panel which is operated by an image information writing means. CONSTITUTION:The visible light from a light source 21 is polarized by the polarization beam splitter 24 and its S polarized component is converted by the lambda/4-wavelength plate 35 into circular polarized light, which is projected on the liquid crystal display panel 25. The panel 25 is operated by the image information writing means consisting of a laser 26, a beam splitter 33, and a liquid crystal driving circuit 29 to reflect the light from the wavelength plate 35, and the reflected light is further converted by a wavelength plate 35 into P polarized light, which is passed through the splitter 24 to form a color image on a screen 32 through filters 31 of respective colors. The visible light becomes the S polarized light which is a half in quantity through the splitter 24 and the P polarized light of the wavelength plate 35 is passed as it is, so the reduction in the quantity of light is only a half. Consequently, a bright display image is obtained without increasing the quantity of light of the light source.</p> |
