| 摘要 |
The present invention relates to a surface light source having an inclined surface at a light introduction part of a light guide plate, which reduces light leakage from a lateral side of the light guide plate or an optical pattern of a body of the light guide plate. A point light source (32) is provided in opposition to a light incident surface (38) of a light guide plate (33). The light guide plate (33) includes a light introduction part (35) used to confine light incident to the light incident surface (38) from the point light source (32) and a light guide plate body (34) having a thickness thinner than the maximum thickness of the light introduction part (35). The light introduction part (35) has an inclined surface (37) inclined from a surface having a thickness thicker than that of the guide plate body (34) toward an end portion of a surface of the light guide plate body (34). The light guide plate body (34) has orientation changing patterns (40) located between an effective lighting area (46) and the light introduction part (35) to change the orientation of light passing through the effective lighting area (46) from the light introduction part (35) in such a manner that the orientation of the light passing through the effective lighting area (46) from the light introduction part (35) forms a smaller angle with respect to a direction perpendicular to the light incident surface (38) when viewed from the top. |
