| 摘要 |
PROBLEM TO BE SOLVED: To uniform the distribution of emitted light quantity by forming, on the surface side opposed to the emitting surface of a plate member, a high light diffusing area of the level of scattering a lighting light, compared with the adjacent area, in strip, keeping a prescribed distance from the end surface. SOLUTION: A light scattering light guide plate 11 has a light diffusing area 12 on a part of an inclined surface 11B. The light diffusing area 12 is formed into a mat surface (wrinkled surface) having a prescribed roughness by mat surface treatment, and in the section cut by the line B-B, a main light diffusing area 12M is formed with a prescribed width in parallel to an inclined surface 11A, keeping a prescribed distance D from the incident surface 11A, and cushioning light diffusing areas 12S are formed on both sides of the main light diffusing area 12M. The main light diffusing area 12M is formed in a position corresponding to the bright band which first appears from the incident surface side on the emitting surface with a width corresponding to this bright band. The main light diffusing area 12M is formed into a strip area having an excessive lighting light quantity to scatter and distribute the excessive lighting light to the adjacent areas lacking in light quantity. |
