| 摘要 |
PURPOSE: To provide a liquid crystal display device where a high-efficiency backlight made light in weight is mounted by making a light transmission plate wedged and arranging the surface of a prism sheet on a side provided with a prism to be faced to the light transmission plate. CONSTITUTION: The prism sheet 10 is constituted so that its upper surface may be a smooth surface and its lower surface on the light transmission plate 11 side may be a prism surface. The plate 11 is a transparent plate made of acrylic resin and having a wedged cross section, and formed so that its cold cathode fluorescent tube 7 side may be thick and an opposite side may be thin. By making the plate 11 wedged, the backlight becomes light in weight. As for the surface state of the plate 11, four end faces are mirror surfaces, and a reflection tape is stuck to three end faces other than a surface adjacent to the fluorescent tube 7. Two large surfaces are made rough surfaces, and the rough surface state is not uniform on the surface of the plate 11 in order to keep luminance on the surface of the backlight uniform. By entirely making at least either the front surface or the back surface of the plate 11 rough surface, the projected light is adjusted in accordance with the degree of the rough surface. |
