Light guide plate with sharp-edged prisms and side-edge type surface-emission optical apparatus including the same

摘要

In a light guide plate having a light incident surface, a light distributing control surface perpendicular to the light incident surface and a light emitting surface opposing the light distributing control surface, a flat mirror-finish portion is provided on a first area of the light distributing control surface, and a prism sequence is provided on a second area of the light distributing control surface where the flat mirror-finish portion is not provided. The prism sequence is protruded with respect to the flat mirror-finish portion. Each prism of the prism sequence has a rising sloped surface opposing the light incident surface, a first falling sloped surface connected to the rising sloped surface, and a second falling sloped surface connected to the first falling sloped surface, A slope of the first falling sloped surface is larger than a slope of the second falling sloped surface.

主权项

1. A light guide plate having a light incident surface, a light distributing control surface perpendicular to said light incident surface and a light emitting surface opposing said light distributing control surface, comprising:
a flat mirror-finish portion provided on a first area of said light distributing control surface; and a prism sequence provided on a second area of said light distributing control surface where said flat mirror-finish portion is not provided, said prism sequence being protruded with respect to said flat mirror-finish portion, wherein each prism of said prism sequence has a rising sloped surface opposing said light incident surface, a first falling sloped surface connected to said rising sloped surface, and a second falling sloped surface connected to said first falling sloped surface, a slope of said first falling sloped surface being larger than a slope of said second falling sloped surface, wherein each of said first and second falling sloped surfaces is straightly-sloped, wherein a slope angle β1 of said first falling sloped surface with respect to said flat mirror finishing portion satisfies:
3°<β1<8°, wherein a slope angle β2 of said second falling sloped surface with respect to said flat mirror finishing portion satisfies:
0.5°<β2<3°, and wherein an area S12d of said first falling sloped surface and an area S12e of said second falling sloped surface satisfy:
2·S12d≦S12e≦6·S12d.