WO2013035324A1

WO2013035324A1 - Luminous flux control member and illumination device

Info

Publication number: WO2013035324A1
Application number: PCT/JP2012/005631
Authority: WO
Inventors: 昌代瀧澤; 中村　真人
Original assignee: 株式会社エンプラス
Priority date: 2011-09-09
Filing date: 2012-09-05
Publication date: 2013-03-14
Also published as: JP5837374B2; JP2013058440A

Abstract

A luminous flux control member (130) has a substantially circular shape in top view, and has a reflecting surface (132) for reflecting light emitted from a light-emitting element (120), and a transmitting part (134) for transmitting light emitted from the light-emitting element (120). The reflecting surface (132) is a concave surface, the center section (136) of which is nearer the light-emitting element (120) than the outer periphery section (138). The transmitting part (134) is formed in at least the center half region of the luminous flux control member (130) as viewed in plan view.

Description

Luminous flux control member and lighting device

The present invention relates to a light flux controlling member that controls the traveling direction of light emitted from a light emitting element. The present invention also relates to an illumination device having the light flux controlling member, which can be used in place of an incandescent bulb.

In recent years, lighting devices (for example, LED bulbs) using light emitting diodes (hereinafter also referred to as “LEDs”) as light sources have been used as an alternative to incandescent bulbs from the viewpoint of energy saving and environmental conservation.

However, a conventional lighting device using an LED as a light source emits light only in the forward direction, and cannot emit light in a wide range like incandescent bulbs. For this reason, the conventional illuminating device cannot illuminate the room widely using the reflected light from a ceiling or a wall surface like an incandescent bulb.

In order to bring the light distribution characteristics of such a conventional LED light source into a light distribution characteristic of an incandescent bulb, it has been proposed to control the traveling direction of light emitted from the LED with a light flux control member (for example, , See Patent Document 1).

FIG. 1 is a schematic diagram showing a configuration of an illumination device including a light flux controlling member (reflecting mirror) described in Patent Document 1. As illustrated in FIG. 1, the lighting device 10 includes a substrate 20, a plurality of LEDs 30 disposed on the substrate 20, and a reflecting mirror 40 that reflects light emitted from the LEDs 30. The reflecting surface of the reflecting mirror 40 has substantially the same shape as the side surface of the truncated cone. As indicated by arrows in FIG. 1, among the plurality of LEDs 30, the emitted light from the LEDs 30 arranged inside the reflecting mirror 40 becomes the emitted light in the forward direction (upward direction) as it is. On the other hand, the emitted light from the LED 30 arranged outside the reflecting mirror 40 is reflected by the reflecting surface of the reflecting mirror 40 and becomes emitted light in the lateral direction (horizontal direction) or the backward direction (downward direction). .

Thus, by controlling the traveling direction of the emitted light from the LED using the reflecting mirror, it is possible to obtain the emitted light not only in the forward direction but also in the lateral direction and the backward direction. Therefore, by using the light flux controlling member (reflecting mirror) described in Patent Document 1, the light distribution characteristic of the lighting device (LED light bulb) can be brought close to the light distribution characteristic of the incandescent light bulb.

Registered Utility Model No. 3169310

However, in the light flux controlling member (reflecting mirror) described in Patent Document 1, the light emitted from the light emitting element (LED) disposed in the center of the substrate becomes the light emitted in the forward direction as it is. There is a problem that the amount of emitted light cannot be controlled. For this reason, in the illuminating device using the light flux controlling member described in Patent Document 1, the light distribution characteristic is poor as a whole.

An object of the present invention is to provide a light flux control member that can control not only the amount of emitted light toward the lateral direction and the backward direction but also the amount of emitted light toward the forward direction to make the light distribution characteristics closer to an incandescent bulb. It is. Another object of the present invention is to provide an illumination device having this light flux controlling member.

The light flux controlling member of the present invention is disposed with respect to the light emitting element via an air layer so that the central axis thereof is positioned concentrically with the center of the light flux of one or more light emitting elements disposed on the substrate. A light beam control member having a substantially circular shape in plan view, and having a reflection surface that reflects light emitted from the light emitting element, and a transmission part that transmits light emitted from the light emitting element, The reflecting surface is a concave surface located closer to the light emitting element in the center than in the outer periphery, and when viewed from above, the light flux controlling member has an annular shape composed of 0 to 25% from the outside of the radius. The region is defined as region a, the annular region consisting of 25 to 50% from the outside of the radius is defined as region b, the annular region consisting of the portion from 50 to 75% from the outside of the radius is defined as region c, and from the outside of the radius. Circular area consisting of 75-100% When the region d is used, the transmissive part is formed at least in a region including the region c and the region d, and the area ratio of the transmissive part in the region c is the transmissive part in the region d. The configuration is equal to or greater than the area ratio.

The illuminating device of the present invention includes one or more light emitting elements disposed on a substrate, the light flux controlling member disposed via an air layer with respect to the light emitting elements, and an outer edge of the light flux controlling member. A side wall portion extending toward the substrate side and a cover including a lid portion disposed through an air layer with respect to the light flux controlling member, and the side wall portion is reflected by a reflecting surface of the light flux controlling member. The light reaching the inner surface of the side wall portion and the light directly reaching the inner surface of the side wall portion from the light emitting element are emitted outward from the outer surface of the side wall portion, and the lid portion of the light flux controlling member A configuration is adopted in which light that has passed through the transmission part and reaches the inner surface of the lid part is emitted outward from the outer surface of the lid part.

The light flux controlling member of the present invention can control not only the amount of emitted light directed in the lateral direction and the backward direction but also the amount of emitted light directed in the forward direction by adjusting the amount of transmitted light of the transmission part. For this reason, the illuminating device of this invention can make the light distribution characteristic of an emitted light close to the light distribution characteristic of an incandescent lamp.

It is a schematic diagram which shows the structure of the illuminating device of patent document 1. FIG. 3 is a cross-sectional view illustrating a configuration of the lighting apparatus according to the first embodiment. 3A is a plan view of the light flux controlling member of the first embodiment, FIG. 3B is a cross-sectional view of the light flux controlling member of the first embodiment, and FIG. 3C is a bottom view of the light flux controlling member of the first embodiment. FIG. 4A and 4B are plan views of the light flux controlling member of the first embodiment for explaining the position of the transmission part. 5A and 5B are cross-sectional views showing an example of an optical path in the illumination device of the first embodiment. 3 is a graph showing the light distribution characteristics of the illumination device according to the first embodiment. 7A is a plan view of the light flux controlling member of the second embodiment, FIG. 7B is a cross-sectional view of the light flux controlling member of the second embodiment, and FIG. 7C is a bottom view of the light flux controlling member of the second embodiment. FIG. It is a top view of the light beam control member of Embodiment 2 for demonstrating the position of a permeation | transmission part. 6 is a graph showing light distribution characteristics of the illumination device according to the second embodiment. 10 is a graph showing a simulation result of light distribution characteristics of the illumination device of the second embodiment. 10 is a graph showing a simulation result of light distribution characteristics of the illumination device of the second embodiment. 10 is a graph showing a simulation result of light distribution characteristics of the illumination device of the second embodiment. 13A and 13B are cross-sectional views showing an example of a method for fixing the light flux controlling member. 14A and 14B are cross-sectional views showing another example of the fixing method of the light flux controlling member. 15A and 15B are cross-sectional views showing another example of the fixing method of the light flux controlling member. 16A is a cross-sectional view of the cover taken along line AA shown in FIG. 14B, and FIG. 16B is a cross-sectional view of the cover taken along line BB shown in FIG. 15B.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
[Configuration of lighting device]
FIG. 2 is a cross-sectional view showing a configuration of lighting apparatus 100 according to Embodiment 1 of the present invention. Lighting device 100 of the present embodiment can be used in place of an incandescent bulb.

As shown in FIG. 2, the lighting device 100 includes a substrate 110, one or more light emitting elements 120, a light flux controlling member 130, and a cover 140.

The light emitting element 120 is a light source of the lighting device 100 and is fixed on the substrate 110. The light emitting element 120 is a light emitting diode (LED) such as a white light emitting diode. When a plurality of light emitting elements 120 are fixed on the substrate 110, each light emitting element 120 is preferably arranged on the circumference.

The light flux controlling member 130 is a member having a substantially circular shape in plan view that controls the traveling direction of the light emitted from the light emitting element 120. As will be described later, the light flux controlling member 130 includes a reflection surface 132 that reflects the light emitted from the light emitting element 120 and a transmission part 134 that transmits the light emitted from the light emitting element 120.

The light flux controlling member 130 is disposed through the air layer with respect to the light emitting element 120 so that the central axis CA thereof coincides with the optical axis LA of the light emitting element 120. That is, the light flux controlling member 130 is disposed so as to face the light emitting element 120. In the case where a plurality of light emitting elements 120 are arranged on the substrate 110, the “optical axis of the light emitting elements” refers to the traveling direction of light at the center of a three-dimensional light beam from the plurality of light emitting elements. In the following description, of the two main surfaces of the light flux controlling member 130, the surface facing the light emitting element 120 (the downward surface in FIG. 2) is referred to as the “inner surface”, and the surface opposite to the inner surface (upward in FIG. 2). Is sometimes referred to as the “outer surface”.

The illumination device 100 of the present invention has a main feature in the configuration of the light flux controlling member 130. Therefore, the configuration of the light flux controlling member 130 will be described in detail separately.

The cover 140 is a hollow member that diffuses light whose traveling direction is controlled by the light flux controlling member 130. The cover 140 includes a side wall portion 142 extending from the outer edge of the light flux controlling member 130 toward the substrate 110 and a lid portion 144 disposed with respect to the light flux controlling member 130 via an air layer. The side wall 142 is located on the inner surface (surface on which the reflecting surface 132 exists) of the light flux controlling member 130, and the lid 144 is located on the outer surface (surface opposite to the inner surface) of the light flux controlling member 130. In the example shown in FIG. 2, the side wall portion 142 and the lid portion 144 are formed as separate members, but they may be integrally formed (see FIGS. 13 to 15).

The side wall part 142 reflects light that has been reflected by the reflecting surface 132 of the light flux controlling member 130 and reached the inner surface of the side wall part 142 and light that has directly reached the inner surface of the side wall part 142 from the light emitting element 120 from the outer surface of the side wall part 142. The light is emitted outward (see FIG. 5A). On the other hand, the lid part 144 emits light that has passed through the transmission part 134 of the light flux controlling member 130 and reached the inner surface of the lid part 144 from the outer surface of the lid part 144 to the outside (see FIG. 5B).

As described above, the cover 140 (the side wall portion 142 and the lid portion 144) diffuses the light whose traveling direction is controlled by the light flux controlling member 130. The means for giving the light diffusion function to the cover 140 is not particularly limited. For example, the inner surface or the outer surface of the cover 140 may be subjected to light diffusion treatment (for example, roughening treatment), or a material having light diffusion ability (for example, a light-transmitting material containing scatterers such as beads). The cover 140 may be manufactured using the same. The shape of the cover 140 is not particularly limited as long as desired light distribution characteristics can be realized. For example, the shape of the cover 140 is a spherical crown (a shape obtained by cutting a part of a spherical surface with a plane).

[Configuration of luminous flux control member]
3A is a plan view of the light flux controlling member 130, FIG. 3B is a cross-sectional view taken along the line BB shown in FIG. 3A, and FIG. 3C is a bottom view of the light flux controlling member 130. As shown in these drawings, the shape of the light flux controlling member 130 is rotationally symmetric about the central axis CA. Therefore, the planar view shape of the light flux controlling member 130 is a substantially circular shape.

3A to 3C, the light flux controlling member 130 has a reflecting surface 132 and a plurality of transmitting portions 134.

The reflection surface 132 is formed on a surface (inner surface; surface shown in FIG. 3C) facing the light emitting element 120 in the illumination device 100. As described above, the reflecting surface 132 reflects the emitted light from the light emitting element 120 toward the side wall 142 of the cover 140 (see FIG. 5A). For example, the reflecting surface 132 can be formed by forming a light reflecting film on the inner surface of the light flux controlling member 130 made of resin or the like. The reflective surface 132 can also be formed by making the light flux controlling member 130 from a light reflective material (for example, a resin such as a white acrylic resin or white polycarbonate, a metal plate, or the like). When these light reflective materials are used, the reflective surface 132 described later functions effectively by forming the reflective surface 132 so as to have gloss.

2 and 3B, the reflecting surface 132 is a concave surface in which the central part 136 located on the central axis CA is located closer to the light emitting element 120 (substrate 110) than the outer peripheral part 138. That is, the reflecting surface 132 is a tapered concave surface that converges on the central axis CA. Usually, the shape of the reflecting surface 132 is a curved surface shape in which the inclination gradually decreases from the central portion 136 to the outer peripheral portion 138 of the light flux controlling member 130. However, the portion of the reflective surface 132 that is farthest from the light emitting element 120 (substrate 110) is not necessarily the outer peripheral portion 138. That is, as shown in FIGS. 2 and 3B, a portion farthest from the light emitting element 120 may be located between the center portion 136 and the outer peripheral portion 138. In this case, the shape of the reflecting surface 132 is an aspherical shape in which a point where the inclination angle is zero is formed between the center portion 136 and the outer peripheral portion 138 and at a position close to the outer peripheral portion 138. Of course, the outer peripheral part 138 may be a part farthest from the light emitting element 120 (substrate 110).

The transmitting part 134 transmits the light emitted from the light emitting element 120 from the inner surface (surface facing the light emitting element 120) side to the outer surface (surface not facing the light emitting element 120) side (see FIG. 5B). In the example shown in FIGS. 2 and 3, the transmission part 134 is a through hole. However, the transmission part 134 may not be a through-hole as long as it can transmit light, and may be, for example, a bottomed recess. In this case, the emitted light from the light emitting element 120 is transmitted through the bottom of the recess (the portion where the thickness is reduced). Usually, these through holes or recesses are formed to be parallel to the central axis CA.

As shown in FIG. 4A, when the light flux controlling member 130 is viewed in a plan view, an annular region composed of a portion of 0 to 25% from the outside of the radius r is defined as “region a”, and 25 to 50 from the outside of the radius r. An annular region consisting of a portion of% is referred to as “region b”, an annular region consisting of a portion of 50 to 75% from the outside of the radius r is referred to as “region c”, and from a portion of 75 to 100% from the outside of the radius r This circular area is referred to as “area d”. In this case, as shown in FIG. 4B, the transmissive portion 134 is formed at least in a region including the region c and the region d. When the transmissive part 134 is not formed in these regions, the light emitted from the front direction (upward) is insufficient in the illumination device 100, and good light distribution characteristics cannot be realized (see FIGS. 5B and 10). ).

The area ratio of the transmission part 134 in the region c is equal to or larger than the area ratio of the transmission part 134 in the region d (c ≧ d; see FIG. 4B). When the area ratio of the transmissive portion 134 in the region c is less than the area ratio of the transmissive portion 134 in the region d (when c <d to the extent that it is not a slight difference), the light transmitted through the region c and traveling in the forward direction is reduced. Accordingly, the light component reflected toward the lateral direction increases (see FIGS. 5A and 5B). Because the light emitting element 120 is a surface emitting light source having a certain area, or the emitted light from the light flux controlling member 130 is diffused by the cover 140, a specific angle (light emission) in the forward direction in the lighting device 100 is obtained. The amount of light emitted from the center through the region c in the forward direction (angle with respect to the optical axis) does not become zero. However, since the emitted light which goes to the extension direction of the line segment which connects the arbitrary points on the light emission surface of the light emitting element 120 and the area | region c runs short, a favorable light distribution characteristic cannot be implement | achieved (refer FIG. 12). When the transmission part 134 is a through hole, the area ratio of the transmission part 134 is the same as the aperture ratio.

Moreover, it is preferable that the transmission part 134 is not formed in the area a located on the outermost periphery side (see FIG. 4B). When the transmissive part 134 is formed in the area a, the transmissive part 134 formed in the area a and the cover lid part 144 are close to each other, so that a spot pattern is formed on the cover lid part 144 in the illumination device 100. It may appear and look bad. In addition, about the area | region b, the permeation | transmission part 134 may be formed (refer FIG. 4B), and does not need to be formed.

Specifically, the area ratio (aperture ratio) of the transmission part 134 in each region of the light flux controlling member 130 preferably satisfies the following conditions.
-Region a: 0 area%
Area b: 0 to 30 area%
-Region c: 10 to 50 area%
Region d: 0 to 15 area% (however, it is not more than the area ratio of the transmission part 134 in the region c)
-Total of region c and region d: 10 to 50 area%

The area ratio (aperture ratio) of the transmission part 134 in each region of the light flux controlling member 130 shown in FIGS. 2 to 4 is as follows.
-Region a: 0 area%
-Region b: 5.3 area%
-Region c: 25.5 area%
-Region d: 13.3 area%

The material of the light flux controlling member 130 is not particularly limited as long as it has a desired strength and the reflection surface 132 has reflection characteristics. Examples of the material of the light flux controlling member 130 include resins such as polymethyl methacrylate (PMMA), polycarbonate (PC), and liquid crystal polymer (LCP), and metals (alloys) such as aluminum (Al) and stainless steel (SUS). , Glass and so on.

FIG. 5A is a schematic diagram showing a state in which light emitted from the light emitting element 120 is reflected by the reflecting surface 132 of the light flux controlling member 130. FIG. 5B is a schematic diagram illustrating a state in which emitted light from the light emitting element 120 is transmitted through the transmission part 134 of the light flux controlling member 130. In FIG. 5B, it is indicated which region of the transmission part 134 each light beam has transmitted.

As shown in FIG. 5A, the light reflected by the reflecting surface 132 is emitted in the lateral direction or the backward direction through the side wall portion 142. The light emitted from the light emission center of the light emitting element 120 is converted to the light which is reflected more backward in the light reflected in the vicinity of the outer peripheral portion 138 than in the light reflected in the vicinity of the central portion 136. Further, as shown in FIG. 5B, the light that has passed through the transmission part 134 formed in the region b, the region c, and the region d of the light flux controlling member 130 is emitted forward through the lid 144.

[Measurement of light distribution characteristics of lighting equipment]
The light distribution characteristics of the illumination device 100 of the first embodiment shown in FIG. 2 were measured. The light flux controlling member 130 was produced by cutting a white acrylic resin plate. In addition, the parameter of each component of the illuminating device 100 is as follows.
-Size of light emitting element 120: 20 × 15 mm
The distance between the light emitting element 120 and the center part 136 of the light flux controlling member: 3 mm
・ Height of the side wall 142 of the cover: 12 mm
-Overall height of cover 140: 30 mm
・ Overall diameter of cover 140: 40 mm
-Height of light flux controlling member 130: 10 mm
-Outer diameter of light flux controlling member 130: 38 mm
-Diameter of transmission part 134 (through hole) formed in region b: 1 mm
-Diameter of transmission part 134 (through hole) formed in region c: 2.4 mm
-Diameter of transmission part 134 (through hole) formed in region d: 1 mm
・ Roughness of reflecting surface 132: Ra 0.03 μm or less, Ry 0.3 μm or less

The light distribution characteristics were measured by the following procedure. An illuminometer was placed at a position (reference position 0 °) that is a predetermined distance away from the light emission center of the light emitting element 120 in the illumination device 100 along the optical axis LA. The illuminance is measured by rotating the illuminance meter 180 degrees in the clockwise direction (+ θ direction) at 5 ° intervals with the light emission center of the light emitting element 120 as the rotation center, and the illuminance is 180 in the counterclockwise direction (−θ direction) at 5 ° intervals. The illuminance was measured after rotating. The relative illuminance (non-dimensional value) when the maximum illuminance among the measured illuminances was 1 was smoothly connected with a curve, and the graph of FIG. 6 was created.

FIG. 6 is a graph showing the light distribution characteristics of the lighting apparatus 100 according to the first embodiment. In this graph, 0 ° means the forward direction (upward direction), 90 ° means the lateral direction (horizontal direction), and 180 ° means the backward direction (downward direction). From FIG. 6, it can be seen that the illumination device 100 of Embodiment 1 has wide (about 270 °) and well-balanced light distribution characteristics.

[effect]
The light flux controlling member 130 according to Embodiment 1 reflects a part of the light emitted from the light emitting element 120 that has reached the light flux controlling member 130 toward the side wall 142 of the cover by the reflecting surface 132 (FIG. 5A). The remaining light is transmitted in the direction of the cover lid 144 by the transmission part 134 (see FIG. 5B). At this time, the amount of emitted light in each direction can be easily controlled by adjusting the position and area ratio of the transmission part 134. As described above, the light flux controlling member 130 according to the first embodiment controls not only the amount of emitted light directed in the lateral direction and the backward direction but also the amount of emitted light directed in the forward direction, thereby making the light distribution characteristics closer to those of the incandescent bulb. Can do.

The lighting device 100 according to Embodiment 1 can be used for indoor lighting or the like instead of an incandescent light bulb. In addition, lighting device 100 of Embodiment 1 can consume less power than incandescent bulbs and can be used for a longer period of time than incandescent bulbs.

(Embodiment 2)
The illumination device 200 (not shown) of the second embodiment includes a substrate 110, one or more light emitting elements 120, a light flux control member 210, and a cover 140. The illuminating device 200 of Embodiment 2 is the same as the illuminating device 100 of Embodiment 1 about components other than the light beam control member 210. FIG. Therefore, in the present embodiment, only the light flux controlling member 210 will be described. Also, the same components as those of the illumination device 100 and the light flux controlling member 130 of Embodiment 1 shown in FIGS. 2 to 4 are denoted by the same reference numerals, and description thereof is omitted.

[Configuration of luminous flux control member]
7A is a plan view of light flux controlling member 210 of Embodiment 2, FIG. 7B is a cross-sectional view taken along line BB shown in FIG. 7A, and FIG. 7C is a bottom view of light flux controlling member 210. is there. FIG. 8 is a plan view of the light flux controlling member 210 of the second embodiment for explaining the position of the transmission part 134.

As shown in FIGS. 7A to 7C and FIG. 8, light flux controlling member 210 of the second embodiment is different from light flux controlling member 130 of the first embodiment in that it has a larger number of transmitting portions 134 (through holes). . Specifically, light flux controlling member 210 of the second embodiment has a large number of transmitting portions 134 depending on region b (see FIG. 4B and FIG. 8 for comparison).

The area ratio (aperture ratio) of the transmission part 132 in each region of the light flux controlling member 210 shown in FIGS. 7 and 8 is as follows.
-Region a: 0 area%
Area b: 15.7 area%
-Region c: 25.5 area%
-Region d: 13.3 area%

[Measurement of light distribution characteristics of lighting equipment]
The light distribution characteristics of the illumination device 200 (not shown) of the second embodiment including the light flux controlling member 210 of the second embodiment shown in FIG. 7 were measured. The procedure for measuring the light distribution characteristic is the same as that described in the first embodiment. The light flux controlling member 210 was produced by cutting a white acrylic resin. In addition, the parameter of each component of the illuminating device 200 is as follows (refer FIG. 2).
-Size of light emitting element 120: 20 × 15 mm
-Distance between light emitting element 120 and light flux controlling member 130: 3 mm
・ Height of the side wall 142 of the cover: 12 mm
-Overall height of cover 140: 30 mm
・ Overall diameter of cover 140: 40 mm
-Height of light flux controlling member 130: 10 mm
-Outer diameter of light flux controlling member 130: 38 mm
-Diameter of outer transmission part 134 (through hole) formed in region b: 1 mm
-Diameter of inner transmission part 134 (through hole) formed in region b: 1.4 mm
-Diameter of transmission part 134 (through hole) formed in region c: 2.4 mm
-Diameter of transmission part 134 (through hole) formed in region d: 1 mm
・ Roughness of reflecting surface 132: Ra 0.03 μm or less, Ry 0.3 μm or less

FIG. 9 is a graph showing the light distribution characteristics of the lighting apparatus 200 according to the second embodiment. From FIG. 9, it can be seen that the illumination device 200 of the second embodiment has a wide (about 270 °) and well-balanced light distribution characteristic, like the illumination device 100 of the first embodiment.

[Simulation of light distribution characteristics of lighting equipment]
Simulation software (LightTools; Optical Research Associates) was used to simulate the light distribution characteristics of the illumination device when the area ratio of the transmission part 134 of the light flux controlling member 210 of the second embodiment was changed. Conditions (parameters) other than the area ratio (aperture ratio) of the transmissive part 134 were set to be the same values as those of the illumination device 200 and the light flux controlling member 210 of the second embodiment.

A light distribution characteristic was simulated for an illumination device including the following four types of light flux controlling members. “Light flux controlling member 1” corresponds to light flux controlling member 210 of the second embodiment (see FIG. 7).
[Flux control member 1]
-Region a: 0 area%
Area b: 15.7 area%
-Region c: 25.5 area%
-Region d: 13.3 area%
[Flux control member 2]
-Region a: 0 area%
Area b: 15.7 area%
-Region c: 0 area%
-Region d: 0 area%
[Flux control member 3]
-Region a: 0 area%
Area b: 15.7 area%
-Region c: 13.3 area%
-Region d: 13.3 area%
[Flux control member 4]
-Region a: 0 area%
Area b: 15.7 area%
-Region c: 0 area%
-Region d: 13.3 area%

FIG. 10 is a graph showing the simulation results of the light distribution characteristics of the illumination device including the light flux control member 1 and the illumination device including the light flux control member 2. A solid line indicates the light distribution characteristic of the lighting device including the light flux control member 1, and a broken line indicates the light distribution characteristic of the lighting device including the light beam control member 2. The light distribution characteristic (measurement result) of the illumination device 200 including the light flux control member 210 shown in FIG. 9 is different from the light distribution characteristic (simulation result) of the illumination device including the light flux control member 1 shown in FIG. It is considered that it is difficult to precisely set the degree of diffusion of light reflected by the reflecting surface 132 of the light flux controlling member 210 and the degree of diffusion of light transmitted through the cover 140 in the simulation.

The light flux controlling member 1 has a transmissive portion 134 formed in both the region c and the region d (c, d> 0). On the other hand, in the light flux controlling member 2, the transmission part 134 is not formed in either the region c or the region d (c, d = 0).

As shown in FIG. 10, in the lighting device including the light flux controlling member 1 (c, d> 0), the light is distributed in a balanced manner in the front direction, the side direction, and the rear direction. On the other hand, in the illuminating device including the light flux controlling member 2 (c, d = 0), although the light is distributed in the lateral direction and the backward direction, the light is hardly distributed in the forward direction. From these results, it is suggested that in order to distribute light in a balanced manner, it is necessary to form the transmission part 134 in both or at least one of the region c and the region d.

FIG. 11 is a graph showing a simulation result of the light distribution characteristics of the illumination device including the light flux control member 1 and the illumination device including the light flux control member 3. The solid line indicates the light distribution characteristic of the lighting device including the light flux control member 1, and the broken line indicates the light distribution characteristic of the lighting device including the light beam control member 3. FIG. 12 is a graph showing a simulation result of the light distribution characteristics of the illumination device including the light flux control member 1 and the illumination device including the light flux control member 4. The solid line indicates the light distribution characteristic of the illumination device including the light flux control member 1, and the broken line indicates the light distribution characteristic of the illumination device including the light flux control member 4.

In the light flux controlling member 1, the area ratio of the transmission part 134 in the area c exceeds the area ratio of the transmission part 134 in the area d (c> d). On the other hand, in the light flux controlling member 3, the area ratio of the transmission part 134 in the region c is the same as the area ratio of the transmission part 134 in the region d (c = d). In the light flux controlling member 4, the area ratio of the transmissive part 134 in the region c is smaller than the area ratio of the transmissive part 134 in the region d (c <d).

As shown in FIG. 11, the lighting device including the light flux controlling member 1 (c> d) and the lighting device including the light flux controlling member 3 (c = d) both distributed light in a well-balanced manner. On the other hand, as shown in FIG. 12, in the illuminating device including the light flux controlling member 4 (c <d), the light is distributed in the lateral direction and the backward direction, but is hardly distributed in the forward direction. It was. From these results, it is suggested that the area ratio of the transmissive portion 134 in the region c needs to be equal to or greater than the area ratio of the transmissive portion 134 in the region d in order to distribute light in a balanced manner.

[effect]
Illumination apparatus 200 according to the second embodiment and luminous flux control member 210 according to the second embodiment have the same effects as illumination apparatus 100 according to the first embodiment and luminous flux control member 130 according to the first embodiment. Illumination apparatus 200 according to Embodiment 2 can be used for indoor lighting instead of an incandescent bulb.

(Modification)
In each of the above-described embodiments, as shown in FIG. 13A (before fixing) and FIG. 13B (after fixing), an example in which the light flux controlling member 130 is fixed by being sandwiched between the side wall portion 142 and the lid portion 144 of the cover will be described. did. However, in the illumination device of the present invention, the method for fixing the light flux controlling member 130 is not limited to this. Moreover, the side wall part 142 and the cover part 144 of the cover do not need to be separate members, and may be integrally formed.

For example, as shown in FIG. 14A (before fixing) and FIG. 14B (after fixing), the light flux controlling member 130 is used by using two

covers

140a and 140b each having a fixing portion 146 for fixing the light flux controlling member 130. May be fixed. Further, as shown in FIG. 15A (before fixing) and FIG. 15B (after fixing), the light flux controlling member 130 may be fixed using an integrated cover 140 having a fixing portion 146.

16A and 16B are a cross-sectional view of the cover 140 taken along line AA shown in FIG. 14B and a cross-sectional view of the cover 140 taken along line BB shown in FIG. 15B. As shown in FIG. 16A and FIG. 16B, a pair of fixing portions 160 may be formed so as to face each other, but may be formed over the entire inner periphery of the cover 140.

Since all of the covers 140 shown in FIGS. 13 to 15 have no undercut portion, they can be easily manufactured by an injection molding method or the like. The method for fixing light flux controlling member 130 and cover 140 is not particularly limited. Examples of the method for fixing the light flux controlling member 130 and the cover 140 include adhesion and press fitting.

This application claims priority based on Japanese Patent Application No. 2011-197168 filed on September 9, 2011. The contents described in the application specification and the drawings are all incorporated herein by reference.

The lighting device including the light flux controlling member of the present invention can be used in place of an incandescent bulb. In addition, since the lighting device including the light flux controlling member of the present invention can arbitrarily adjust the light distribution characteristics according to the application, it can be widely applied to various lighting devices such as chandeliers and indirect lighting devices.

10 Lighting device 20 Substrate 30 LED
40 Reflective mirror 100, 200 Illuminating device 110 Substrate 120

Light emitting element

130, 210 Light flux controlling member 132 Reflecting surface 134 Transmitting portion (through hole)
136 Center part 138 Outer part 140 Cover 142 Side wall part 144 Lid part 146 Fixed part CA Central axis LA Optical axis

Claims

The shape in plan view, which is arranged via an air layer with respect to the light emitting element so that its central axis is located concentrically with the center of the light beam of one or more light emitting elements arranged on the substrate, has a substantially circular shape. A luminous flux control member of
A reflective surface for reflecting the light emitted from the light emitting element;
A transmission part that transmits light emitted from the light emitting element,
The reflective surface is a concave surface located closer to the light emitting element in the center than the outer periphery,
When the light flux controlling member is viewed in plan, a ring-shaped region composed of 0 to 25% from the outside of the radius is defined as region a, and a ring-shaped region composed of 25 to 50% from the outside of the radius is defined as region b. When a ring-shaped region consisting of 50 to 75% from the outside of the radius is a region c and a circular region consisting of a portion of 75 to 100% from the outside of the radius is a region d,
The transmissive part is formed at least in a region composed of the region c and the region d, and an area ratio of the transmissive part in the region c is equal to or larger than an area ratio of the transmissive part in the region d.
Luminous flux control member.
The light flux controlling member according to claim 1, wherein the transmission part is not formed in the region a.
The area ratio of the transmission part in the region c is in the range of 10 to 50 area%,
The area ratio of the transmission part in the region d is 15 area% or less,
The area ratio of the transmission part in the region consisting of the region c and the region d is in the range of 10 to 50 area%.
The light flux controlling member according to claim 1.
The light flux controlling member according to claim 1, wherein the transmission part is also formed in the region b.
The light flux controlling member according to claim 4, wherein an area ratio of the transmission portion in the region b is 30 area% or less.
The light flux controlling member according to claim 1, wherein the transmission part is a through hole or a concave part.
The light flux controlling member according to claim 1, wherein the reflecting surface is an aspherical surface.
One or more light emitting elements disposed on a substrate;
The light flux controlling member according to any one of claims 1 to 7, which is disposed with respect to the light emitting element via an air layer;
A side wall portion extending from the outer edge of the light flux controlling member to the substrate side, and a cover including a lid portion disposed via an air layer with respect to the light flux controlling member,
The side wall portion reflects light that has been reflected by the reflecting surface of the light flux controlling member and reached the inner surface of the side wall portion, and light that has directly reached the inner surface of the side wall portion from the light emitting element from the outer surface of the side wall portion. To the direction,
The lid part emits light that has passed through the transmission part of the light flux controlling member and reached the inner surface of the lid part to the outside from the outer surface of the lid part,
Lighting device.