Light guide plate

A light guide plate comprising a rectangular light exit plan, two light entrance planes respectively connected with the light exit plane at two opposite sides of the light exit plane and a rear plane including two symmetrical planes provided on a side opposite from the light exit plane, a distance of the two symmetrical planes from the light exit plane increasing from the two light entrance planes toward a center of the light exit plane,

• wherein the light guide plate comprises three structural layers disposed on each other in a direction normal to the light exit plane, each of at least two or more of the structural layers containing scattering particles dispersed therein, the structural layers having different particle densities of scattering particles,
• wherein a relationship Np1<Np2<Np3 holds, where Np1 is a particle density of scattering particles of a first structural layer from the light exit plane, and Np2 is a particle density of scattering particles of a second structural layer from the light exit plane, Np3 is a particle density of scattering particles of a third structural layer from the light exit plane, and
• wherein the two symmetrical planes are connected with each other through a flat portion parallel to the light exit plane.