Patent ID: 6786613
Filing Date: 2004-09-07
Classification: G02B,Y10S

Abstract:
A spread illuminating apparatus of side light type, comprising:a light conductive plate made of a light-transmissible material; a bar-like lamp disposed close to and along at least one end surface of the light conductive plate; and a light reflection pattern including a large number of grooves each having an inclined surface in section and formed on one major surface of the light conductive plate, wherein the grooves are formed in such a manner that a depth of each of the grooves increases gradually with an increase in a distance from the lamp, the grooves having the depth equal to a predetermined depth or larger than the predetermined depth have an inclined surface including a non-flat portion having an inclination angle that varies gradually, and an area of the non-flat portion increases gradually with the increase in the distance from the lamp.