| 摘要 |
PURPOSE:To make thickness smaller and to obtain high and uniform luminance by arranging a reflection layer on the base of a transparent substrate of a valley shape in cross section having light transmissivity, a milky white plate atop the substrate, linear-shaped light sources on its flanks and a light diffusion plate on the upper part. CONSTITUTION:A planar light transmission plate is constituted by disposing the reflection layer 3 on the base of the transparent substrate 2 having the valley shape in sectional plane shape and the light transmissivity and disposing the milky white plate 1 having a light diffusion function atop the layer. The linear-shaped light sources 4 are arranged on the flanks of the light transmission plate and the light diffusion plate 5 is arranged in the upper part, by which the light source device is constituted. For example, a transparent acrylic plate, etc., are used for the transparent substrate 2. For example, a milky white acrylic resin plate, etc., are used for the milky opaque plate 1. For example, a light transmission plate deposited with metal, such as aluminum, by evaporation on the base of the plate is used for the light reflection layer 3. The shape at the boundary between the milky white plate 1 and the transparent substrate 2 is formed as a shape symmetrical with the central part between the light sources. The light reflection plate is so mounted as to cover the linear-shaped light sources 4. |
