Patent ID: 7828473
Filing Date: 2010-11-09
Classification: G02B,G02F,H01L

Abstract:
1. A light emission device including a light emitting diode element for use as a backlight luminous source in a liquid crystal panel display apparatus comprising a pair of substrates, a liquid crystal layer disposed between said pair of substrates and a polarization plate, wherein said light emitting diode element includes a substrate having first and second in-plane directions, each parallel to a main surface of said substrate and perpendicular to each other, a light emissive layer formed over said substrate and having a main surface which is parallel to the main surface of the substrate, and a waveguide for outputting light from said light emissive layer, said waveguide including a bottom main surface facing said main surface of said light emissive layer, an upper main surface opposite to and parallel to said lower main surface, first and second side portions, perpendicular to said upper and lower main surfaces and located between said upper and lower main surfaces, said first and second side portions extending in said first in-plane direction of said substrate, and said waveguide further including first and second end faces, perpendicular to said upper and lower main surfaces and located between said upper and lower main surfaces, said first and second end faces each extending in said second in-plane direction of said substrate, wherein said first end face of said waveguide is coated with a low reflective film to permit outputting of light from said light emissive layer and wherein said second end face of said wave guide is coated with a high reflective film for reflecting light from said light emissive layer to said first end face of said waveguide for outputting of said light from said light emitting diode element, wherein outgoing light from said light emissive layer is linearly polarized in advance, and wherein outgoing light from said light emissive layer is output from said waveguide in said first in-plane direction of said substrate through said first end face of said waveguide in a parallel direction with the main surface of said light emissive layer, said light emitting diode element including therein the waveguide arranged for outputting from said first end face, said first in-plane direction of the substrate, polarized light components from said light emissive layer to thereby permit parallel incidence with respect to a polarized light transmission direction of the polarization plate of said liquid crystal panel, said light emitting diode element including a first buried layer and a second buried layer respectively extending over said first and second side portions of said waveguide along the first in-plane direction, and said light emitting diode element having the waveguide included therein is mounted and arranged so that the polarized light transmission direction of the polarization plate of said liquid crystal panel is identical to a polarization direction through an optical system.