Patent ID: 9535204
Date: 2017-01-03
CPC Classifications: G02B

Claim:
1. A spread illuminating apparatus, comprising: a light source; and a light guide plate having a light incident surface as an end face on which the light source is placed, and an emitting surface that is included in a surface connecting to one of two end sides in a longitudinal direction of the light incident surface and that emits light incident on the light incident surface, wherein the light guide plate has a light incident wedge portion integrally formed with the light guide plate, the light guide plate and the light incident wedge portion being both made of a transparent material, the light incident wedge portion includes a tilted surface, a thickness of the light incident wedge portion is reduced from the light incident surface side toward the emitting surface side, the tilted surface has an S-shape as viewed from a side, which has a convex portion on the light incident surface side and a concave portion on the emitting surface side with an inflection point therebetween, and a distance from the light incident surface to the inflection point is larger than the thickness of the light incident surface.