LIGHT GUIDE PLATE AND BACKLIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain a light guide plate capable of attaining a sufficient luminescence area even in the case of a small-sized thin plate and having enhanced strength as compared with the conventional wedge-shaped one by forming plural inclined parts at the under surface of a plate from the light incidence side toward the opposite side. SOLUTION: The light guide plate 1 is obtained by injection-molding a synthetic resin such as an acrylic resin or a polycarbonate and has a nearly rectangular cross section and plural inclined parts at the under surface. The inclined parts are continuously formed along the traveling direction of light at a uniform width and the same angle of inclination. When light is incident from a light source 2 on the light guide plate 1, the traveling direction of light reflected by the upper surface of the plate 1 is changed whenever the light is reflected by an inclined surface, the incident angle to the upper surface is gradually reduced and light emerges gradually from the upper surface. The conventional effect is therefore produced while reducing the thickness of the light guide plate 1.