Light guide block and related illumination device and backlight module having the same

摘要

A backlight module (300) includes a plurality of illumination devices (100). Each of the illumination devices includes a light guide block (120) and a point light source (140) optically coupled with the light guide block. The light guide block includes a light exit surface (121), a bottom surface (123) opposite to the light exit surface, and a tapered portion (122) located between the light exit surface and the bottom surface. The bottom surface has a receiving hole (1232) formed therein. The tapered portion includes an outside surface (1221) and a prism array (1224) formed on the outside surface. The point light source is secured in the receiving hole. The plurality of illumination devices are joined with one another and the light exit surfaces of light guide blocks are substantially coplanar and whereby cooperatively constitute a light output surface of the backlight module.