LIGHT FLUX CONTROL MEMBER, LIGHT-EMITTING DEVICE, PLANAR LIGHT SOURCE DEVICE AND DISPLAY DEVICE

摘要

This light flux control member comprises an entry surface, a reflective surface, a circular groove containing a first circular surface and a second circular surface, and an exit surface. The circular groove is disposed in such a manner as not to intersect with the optical path of a light from the entry surface to the reflective surface, and, in such a manner as to intersect with at least a portion of the optical path of a light, from being emitted from a point other than the center of the light-emitting element, entering at the entry surface and being reflected at the reflective surface, to reaching the exit surface. The second circular surface is formed in such a manner that the width of the circular groove widens as the opening ridges of the circular groove is approached from the valley portion of the circular groove.

主权项

1. A light flux controlling member for controlling a distribution of light emitted from a light emitting element, the light flux controlling member comprising:
an incidence surface on which light emitted from the light emitting element is incident, the incidence surface being disposed on a rear side to intersect with a central axis of the light flux controlling member; a reflection surface configured to reflect light incident on the incidence surface in a lateral direction, the reflection surface being disposed on a front side such that a distance from the light emitting element increases from a center portion toward an outer periphery portion of the reflection surface; an annular groove including a first annular surface and a second annular surface and disposed on a rear side at a position outside the incidence surface to surround the central axis, the first annular surface being disposed on the central axis side, the second annular surface being disposed outside the first annular surface; and an emission surface configured to emit light reflected by the reflection surface, the emission surface being disposed outside the annular groove to surround the central axis, wherein: the annular groove is disposed such that the annular groove does not intersect with a light path of light emitted from a center of the light emitting element in a region from a point of incidence of the light on the incidence surface to a point of reflection of the light at the reflection surface and that the annular groove intersects with at least a part of a light path of light which is emitted from the light emitting element and is incident on the incidence surface in a region from a point of reflection of the light at the reflection surface to a point of arrival of the light at the emission surface, and the second annular surface is formed such that a width of the annular groove increases toward an opening edge of the annular groove from a valley part of the annular groove, the second annular surface being configured to refract, toward the front side, light emitted from the light emitting element which is incident on the incidence surface and is reflected by the reflection surface.