SURFACE ILLUMINATING LIGHT SOURCE DEVICE AND SURFACE ILLUMINATING DEVICE

摘要

Uniform illuminating light is obtained on a surface at a prescribed distance from a radiation surface without increasing the thickness of light in a radiation direction by using light from the light source at a high efficiency. A surface illuminating light source device is provided with a light source for radiating light; a light guide body which propagates light from the light source and has the radiation surface at a prescribed position in the radiation direction; a casing having surfaces closed except the radiation surface of the light guide body and has a light source arranged substantially at the center; an inner reflection section which is arranged between the casing and the light guide body and has a reflection surface which reflects light propagating inside the light guide body; and a radiation side reflection section having an outer reflection section which is arranged on the radiation surface and has a reflection surface that reflects light propagating inside the light guide body at a prescribed rate, and an opening section which is formed on the outer reflection section and passes through reflection light reflected at least once by one of the reflection surfaces among the light from the light source (12).