| 主权项 |
1. A light flux controlling member configured to control a distribution of light emitted from a light emitting element, the light flux controlling member disposed such that a central axis of the light flux controlling member coincides with an optical axis of the light emitting element, the light flux controlling member comprising:
an incidence surface configured such that light emitted from the light emitting element is incident on the incidence surface, the incidence surface being an inner surface of a recess disposed on a side of the light flux controlling member closer to the light emitting element to intersect with the central axis; a reflection surface configured to reflect part of the light incident on the incidence surface, the reflection surface being disposed to surround the central axis; and an emission surface configured to emit the light incident on the incidence surface, the emission surface being disposed on an opposite side of the light flux controlling member from the incidence surface to intersect with the central axis, wherein, the incidence surface comprises: a top surface in the recess, the top surface being a part of a rotationally symmetrical surface, a rotation axis of the rotationally symmetrical surface being a straight line located on a side near the light emitting element and perpendicularly intersecting with the central axis, and a side surface connecting an outer edge of the top surface with an opening edge of the recess,
wherein the top surface is divided by a first plane into a first top surface and a second top surface, the first plane including the central axis and being perpendicular to the rotation axis; andin a cross-section taken along a second plane which includes the central axis and is perpendicular to the first plane, an angle which is a smaller angle of two angles between a tangent to the first top surface and the central axis is larger than an average angle which is a smaller average angle of two average angles between a tangent to the second top surface and the central axis; the emission surface is a part of a rotationally symmetrical surface with the straight line as a rotation axis, and is divided by the first plane into a first emission surface and a second emission surface;
wherein in the cross-section taken along the second plane, an average angle which is a smaller average angle of two average angles between a tangent to the first emission surface and the central axis is smaller than an average angle which is a smaller average angle of two average angles between a tangent to the second emission surface and the central axis; the first top surface is disposed on a same side of the first plane as the first emission surface; and in a cross-section taken along the first plane, an intersection point of a tangent to at least one reflection surface and the central axis is disposed between the incidence surface and the rotation axis. |
