Patent ID: 9222646
Filing Date: 2015-12-29
Classification: F21V,G02B

Abstract:
1. A light flux controlling member that controls 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; a total reflection surface that totally reflects part of the light incident on the incidence surface; and an emission surface that emits the part of the light incident on the incidence surface and the light reflected by the total reflection surface, wherein the incidence surface is so formed as to face the light emitting element and to intersect with a central axis of the light flux controlling member, the emission surface is so formed as to face away from the incidence surface and to intersect with the central axis of the light flux controlling member, the total reflection surface is so formed as to surround the central axis of the light flux controlling member and to have a diameter that gradually increases from a side of the incidence surface toward a side of the emission surface, and, when the light flux controlling member is disposed in a three-dimensional orthogonal coordinate system in such a manner that a light emission center of the light emitting element is located at an origin, that the central axis of the light flux controlling member corresponds to a z axis, and that a direction in which light travels from the light emission center of the light emitting element toward the emission surface is a forward direction of the z axis, the emission surface satisfies the following Expression (1) and Expression (2) where ΔZ