SURFACE LIGHT SOURCE DEVICE AND LIQUID CRYSTAL DISPLAY.

摘要

The present invention provides a surface light source device capable of emitting light with high uniformity in luminance. A surface light source device comprising a plurality of light sources spaced from one another, and a plate 3 with a light deflecting structure which is disposed on the front side of these light sources so as to change the direction of light emitted from the light sources, wherein the plate 3 with the light deflecting structure consists of a light-transmitting plate which has a relief structure 4 formed on its light outgoing surface 3b; wherein the relief structure 4 comprises a plurality of triangular ridges 6 with triangular sections projected from the plate; and wherein the slopes 14 inclined downward to the left, of the triangular ridges 6, include steep slopes 16 having an inclination angle within a specified range, and gentle slopes 17 having an inclination angle within a specified range; and the slopes 15 inclined downward to the right, of the triangular ridges, include steep slopes 16 having an inclination angle within a specified range, and gentle slopes 17 having an inclination angle within a specified range.