| 摘要 |
PROBLEM TO BE SOLVED: To obtain lighting of higher luminance than that obtained by using a light shield plate without partially lowering the luminance of a fluorescent tube by passing part of the light emitted by a light source through a light guide plate which is obliquely arranged. SOLUTION: The light guide plate 4 is arranged slantingly above so that part of the light emitted by a fluorescent tube 8 can pass through the light guide plate 4. In the back light body 1, the whole of the light emitted by the fluorescent tube 8 is not made incident directly on the diffusion plate and part of the light passes through the light guide plate 4 and is projected from the upper end surface of the light guide plate 3 and diffused to selectively irradiate a position which is far away from the fluorescent tube 8 and low in luminance. The degree of diffusion of this light is only adjusted according to the finish state of the upper end surface. Consequently, the back light body 1 decreases in high/low difference in luminance due to the difference in the distance of a diffusion plate from the fluorescent tube 8, so that the entire surface of the diffusion plate can be irradiated nearly uniformly. |
