| 摘要 |
Provided is an optical element that diffuses light from a light source and is able to reduce color differences arising depending on the direction of the light. The optical element is configured in a manner so as to be provided with an entrance surface that covers light sources disposed on a plane, and an exit surface that covers the entrance surface, and light from the light sources passes through the entrance surface and exit surface and then is radiated to the outside. With the central axis of the optical element as the optical axis, in a cross section of the optical element perpendicular to the plane and containing the optical axis, when the angle of the normal line of the exit surface at a point (Q) on the exit surface to the optical axis is &phgr; and the distance of point (Q) to the optical axis is r, the exit surface is configured in a manner such that the ratio of &phgr; to r has at least three maximum values and at least three minimum values. |
