LIGHT GUIDE BODY AND SURFACE LIGHT SOURCE DEVICE AND LIQUID CRYSTAL DISPLAY DEVICE BOTH USNIG THE BODY

摘要

PROBLEM TO BE SOLVED: To provide an inexpensive surface light source device having a simple structure and an optical system realizing an illumination efficiency higher than that of conventional ones by making an outgoing beam from a light guide body more abundant in the light condensing property and further being excellent in the assembling property and to provide a liquid crystal display device using the surface light source device as a backlight optical system. SOLUTION: In the light guide body 21 making at least one side end part 21a to be a light incident surface and one surface to be a light emitting surface 21b, the light guide body 21 is characterized by being provided with a light extraction mechanism 290 consisting of a projecting and recessing part 29 emitting light in large quantity to the side opposite to the light emitting surface 21b and by making the shape of the projecting and recessing part 29 seen directly above the light emitting surface 21b to be protruding in the principal traveling direction of the light.