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 consists of a light deflection means and the first light emitting element and the second light emitting device. It said light deflecting means is provided with a light guide plate having an opposing face opposing to the light output surface and the light exit surface for emitting the light incident end surface and the light incident to the light. Facing surface of the light guide plate is formed along a circular arc forming a semi-circular shape of concentric circles centered at the center position in the longitudinal direction of the light incidence end face, a plurality of arc-shaped inclined surfaces that slope at an angle determined in advance is installed. The first light emitting device is arranged on the central position of the light incident end face of the light guide plate, and the second light emitting element is disposed in at least two predetermined distance apart position with respect to the center position. ; A liquid crystal display device, a surface light source, light deflecting means, the light guide plate, the light incident end surface, the light exit surface, arc-shaped inclined surfaces, light emitting element, arc-shaped prism