UNIT LIGHT GUIDE PLATE, LIGHT GUIDE PLATE UNIT, PLANAR ILLUMINATING DEVICE AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

A unitary light guide plate as well as a light guide plate unit include a light exit plane, a thick portion located substantially on a center portion of the light exit plane, thin end portions formed on both sides of the thick portion, a half portion of a parallel groove formed on a backside of the light exit plane to accommodate linearly arranged light sources, inclined back portions arranged so as to become thinner from the thick portion to the thin end portions, and scattering means for scattering light entering from the light sources accommodated in the parallel groove into the thin end portions and propagated through the inclined back portions toward the thick portion. A unitary light guide plate includes a point-like light source, a light exit plane for emitting light, a backside facing the light exit plane, a lateral plane connected to the light exit plane and the backside, a light entrance portion for disposing the point-like light source and causing the incident light to enter to an inside thereof, and scattering means for scattering light entering to the inside and emitting the light from the light exit plane, wherein a distance between the light exit plane and the backside becomes lager with an increasing distance from the light entrance portion.