| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a backlight illumination device uniformly illuminating a liquid crystal display device turning light from an LED light source into uniform and directional illumination light by using a light guide passage. <P>SOLUTION: The backlight illumination device, illuminating a liquid crystal display panel 20 from backside, has more than one unit of illumination units with identical construction composed of a single LED light source 10 and a light guide passage structure 13 for heightening the directivity of illumination light by guiding the light from the LED light source; and a diffusion plate 15 arranged between the illumination unit and the liquid crystal display panel 20, diffusing the light emitted from the LED light source guided by the light guide structure with a prescribed diffusion angle. The light guide passage structure 13, having hollow light guide space, guides the light by a reflection face having no curvature in light guide direction, of which an opening at light emission side is larger than that at light incident side. A main light beam Ax from the LED light source 10 almost coincides with a light guide passage central line corresponding to the LED light source, and the main light beam Ax crosses the diffusion plate 15 almost at right angle. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
