| 摘要 |
PROBLEM TO BE SOLVED: To provide an illuminating device which allows uniform surface light emission and very thin depth with a simple structure by integrally installing a light guide section formed approximately in the same broadening angle as the light emitting angle peculiar to the light source and a diffusion section which reflects the incident light coming from the light source on a light guide plate. SOLUTION: A diffusion plate 1 which is formed by transparent acrylic material, etc., to guide and diffuse the light from a LED 2 is in contact with the LED 2 used as a light source lamp on a surface 1d. The diffusion plate 1 is composed from a light guide section 1a which is broadened and extended in the opening angle of the same extent as the broadening angle of the the light emission flux from the surface 1d and a diffusion section 1b having a reflecting layer 1c for causing the light guided by this light guide section 1a to be reflected irregularly toward the LCD 5 side. Thus, because the broadening angle of the light guide section 1a of the diffusion plate 1 is set based on the relative radiant-intensity characteristic of the LED 2, the light reflected from the reflection layer 1c causes a uniform surface light emission, allowing a thin depth with a simple constitution. |
