| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface light source used in a display that enables to improve image resolution by adjusting the directivity. SOLUTION: A light beam emitted from a point light source 45 is emitted from a linearly extended region by a wedge-shaped light conductive body 47, deflected by a prism sheet 50. The light beam is cast in the direction perpendicular to the light incident surface 44a of a light conductive plate 44 with narrow directivity along the width of the light conductive plate 44. The light conductive plate 44 has a bottom provided with a plurality of right triangular diffusion patterns 46, from which the light rays reflected are case in the direction perpendicular to the light emitting surface 44b of the light conductive plate 44. Meanwhile, a part of the light beam incident on the diffusion pattern 46 penetrates it so as to narrow the directivity of the emitted light along longitudinal direction of the light conductive plate. |
