| 摘要 |
PROBLEM TO BE SOLVED: To suppress a hot spot and light and dark lines that emission light nearby an incidence surface forms without spoiling divisional light emission properties.SOLUTION: A light guide plate 1 includes an incidence surface 10 on which light emitted from a spot light source is made incident and an emission surface 11 from which the light made incident from the incidence surface 10 is emitted, and a propagation reflection surface 12 reflecting the light toward the emission surface 11 is formed on the reverse surface on the opposite side from the emission surface 11. The emission surface 11 comprises a propagation region 11a adjoining the incidence surface 10, a diffusion propagation auxiliary region 11b adjoining the propagation region 11a, and a diffusion propagation region 11c adjoining the diffusion propagation region 11b. Mainly a hot spot and light and dark lines mainly nearby the incidence surface are controlled by a curved part at an upper end of a prism formed in the diffusion propagation region 11c and mainly visual field characteristics of the light guide plate 1 are controlled by a linear part of the prism. |
