Patent ID: 8556493
Filing Date: 2013-10-15
Classification: G02B

Abstract:
1. A spread illuminating apparatus comprising: a point light source; a light guiding plate having a light incident face on which the point light source is mounted, and a light output face for planarly outputting light that has been introduced from the light incident face, the light incident face having light incident prism thereon so as to diffuse light that has been emitted from the point light source into a planar space substantially parallel with the light output face, wherein the light incident prism include: a first prism portion including a plurality of first prisms convex relative to the light incident face; and a second prism portion including a second prism convex relative to the light incident face, the second prism portion being placed next to the first prism portion in a longitudinal direction of the light incident face, the first prism partially overlaps another first prism adjacent thereto, and the vertex of each first prism is set higher than the vertex of the second prism relative to the light incident face.