| 摘要 |
PROBLEM TO BE SOLVED: To improve luminance distribution on the light emitting face by forming light scattering face to scatter the light in at least one of the light emitting face of a plate-like member and the face on the opposite to the light emitting face in a manner that the scattering is gradually decreased as it becomes far from the end face. SOLUTION: The cross-section shapes of plate-like members are formed into a wedge-like shape and a pair of the members are installed along the pieces of light emitting members on the opposite to the plate-like members. Illumination light emitted out of a fluorescent lamp 40 enters light guide plates 32A. 32B. In the rear faces 32N of the light guide plates 32A, 32B, the roughness per unit surface area is gradually deceased and the wedge-type tip end side is formed to be a specular face and light scattering is gradually decreased as it is getting far from the light receiving faces, so that the illumination light is distributed in the center part of the light emitting part to improve the brightness distribution. By utilizing the plate-like members with a small surface area, the light emitting face with a large surface area is illuminated. The assembling work and the maintenance work are simplified by making a light source to be a unit and installing the unit of the light source in a frame unit. |
