SURFACE LIGHT SOURCE CAPABLE OF CHANGING RANGE OF SPREAD ANGLE OF EXIT LIGHT, AND LIQUID CRYSTAL DISPLAY APPARATUS USING THIS SURFACE LIGHT SOURCE

摘要

A surface light source capable of changing the range of a spread angle of exit light and an LCD(Liquid Crystal Display) apparatus using the same are provided to control the lighting of light emitting devices, thereby emitting selectively the light beams with different diffusion angles. The surface light source includes the first and second light sources having at least one light emitting diodes(25a,25b,25c). A light deflection device emits the light beam of the first light source as the first illumination light beam with the previously defined diffusion angle range. The light deflection device also emits the light beam of the second light source as the second illumination light beam with the previously defined diffusion angle range wider than that of the first illumination light beam. The light deflection device includes a light incoming surface(12) for receiving the light beams of the first and second light sources. A light exiting surface emits the light beam induced from the inside of a transparent member to the previously set direction. An opposite surface is installed at another plate surface opposite to the light exiting surface. A light guide panel is installed at any one of the light exiting surface or the opposite surface.