OPTICAL WAVEGUIDE, AND PLANAR ILLUMINATING APPARATUS AND LIQUID CRYSTAL DISPLAY APPARATUS USING THE OPTICAL WAVEGUIDE

摘要

An optical waveguide is provided with a plurality of transparent optical waveguides, and thin edge parts of the adjacent optical waveguide units are connected. The connected optical waveguide units are arranged to constitute a same flat plane by light projecting planes of the optical waveguide units. A shape of the optical waveguide unit satisfies 1.6R≤L and 0.6R≤D, where, R is a diameter of a bar-shaped light source, L is a distance from a plane, which passes a center axis of the bar-shaped light source and is vertical to the light projecting plane, to an edge plane of the thin edge part, which is a connecting part of the adjacent optical waveguide units, and D is the maximum thickness of a thick part of the optical waveguide unit. Thus, the larger size light projecting plane is provided, and projecting efficiency of the light projected from the light source is improved.