LIGHT FLUX CONTROLLING MEMBER, LIGHT EMITTING DEVICE AND ILLUMINATION APPARATUS

摘要

Light flux control member has first light flux control member and second light flux control member facing first light flux control member. First light flux control member and second light flux control member both have central axes which coincide with optical axis of a light emitting element. In inclined Fresnel lens of first light flux control member, the distance from troughs between annular projections to lower side step in optical axis direction is small for outer troughs, and gradually increases for troughs closer to optical axis. According to the present invention, a light flux control member which, from among the front, side, and rear, is capable of balanced distribution of light in at least two of those directions, a light emitting device, and an illumination device can be provided.

主权项

1. A light flux controlling member for controlling a distribution of light emitted from at least one light emitting element, the light flux controlling member comprising:
a first light flux controlling member disposed to face the light emitting element; and a second light flux controlling member disposed to face the first light flux controlling member, wherein: the first light flux controlling member includes a Fresnel lens part that has a plurality of rotationally symmetrical annular projections about an optical axis of the light emitting element as a rotation axis and faces the light emitting element, and an emission surface that faces the second light flux controlling member to emit light controlled by the Fresnel lens part toward the second light flux controlling member, each of the annular projections has an inner first inclining surface configured to receive a part of the light emitted from the light emitting element, and an outer second inclining surface for reflecting a part of the light having entered the first inclining surface toward the second light flux controlling member, the second light flux controlling member includes a reflection surface that faces the emission surface of the first light flux controlling member to reflect a part of light emitted from the first light flux controlling member and reached the second light flux controlling member, and to transmit a rest of the light, the reflection surface is a rotationally symmetrical plane about the optical axis as a rotation axis, the rotationally symmetrical plane having a generatrix line that is a concave curve relative to the first light flux controlling member, an outer peripheral portion of the reflection surface is located at a position distant from the light emitting element in a direction of the optical axis compared with a center portion of the reflection surface, and the Fresnel lens part includes an inclining Fresnel lens part at which a distance in the direction of the optical axis from a valley formed between the adjacent annular projections to a mounting surface on which the light emitting element is to be mounted is gradually increased toward the optical axis away from an outside .