Display apparatus and back light unit to be used therefor

A back light unit for irradiating a light onto a liquid crystal panel,

• wherein the back light unit comprises a light source unit having in combination with a light source for emitting a light, and an optical waveguide having translucency to guide a light of said light source in a direction of the liquid crystal panel, and a chassis for holding or supporting said light source unit, the optical waveguide is formed plate-like, as well as, a face opposing to the back face of the liquid crystal panel is used as a light emitting surface for emitting a light, and said light emitting surface is formed in nearly a plane, and a bottom face opposing to the chassis is used as a reflecting face for reflecting a light, and one of a plurality of side faces adjacent to the light emitting surface and the reflecting face is used as a light incidence surface where a light from the light source is injected,
• a plurality of the light source units are arranged so that the light source of the other light source unit is positioned at the chassis side of the reflecting face of the optical waveguide in one of the light source units, and
• a plurality of the optical waveguides are one-piece molded, and at the light emitting surface or the bottom face of said one-piece molded optical waveguide, a light regulation unit is installed, which unit is one for determining boundary of the light source unit, and also for limiting a light from the optical waveguide of a certain light source unit toward the optical waveguide of other light source unit.