阅读说明：本技术 光束控制部件、发光装置及照明装置 (Light flux controlling member, light emitting device, and lighting device ) 是由 关晃伸 筱原浩之 于 2019-10-10 设计创作，主要内容包括：光束控制部件包括：入射面；两个反射面,使由入射面入射的光的一部分向与发光元件的光轴大致垂直且彼此相反的方向反射；以及两个出射面,隔着两个反射面相对配置。入射面具有：凹部的内顶面；以及两个内侧面,隔着凹部的内顶面而配置。在内顶面配置有多个第一凸条,该多个第一凸条具有在沿着发光元件的光轴观察时大致平行于两个出射面彼此相对的方向的棱线,且第一凸条的高度随着接近两个出射面而变低。(The light flux controlling member includes: an incident surface; two reflecting surfaces that reflect a part of light incident from the incident surface in directions substantially perpendicular to an optical axis of the light emitting element and opposite to each other; and two emission surfaces arranged to face each other with the two reflection surfaces interposed therebetween. The incident surface has: an inner top surface of the recess; and two inner side surfaces disposed with the inner top surface of the recess interposed therebetween. The inner top surface is provided with a plurality of first convex strips, the first convex strips are provided with ridgelines which are approximately parallel to the direction in which the two emission surfaces are opposite to each other when being observed along the optical axis of the light-emitting element, and the height of the first convex strips is reduced as the first convex strips approach the two emission surfaces.)

1. A light flux controlling member for controlling distribution of light emitted from a light emitting element, comprising:

an incident surface that is an inner surface of the concave portion disposed on the rear surface side and on which light emitted from the light emitting element is incident;

two reflecting surfaces which are arranged on a front surface side and reflect a part of light incident from the incident surface in two directions which are substantially perpendicular to an optical axis of the light emitting element and are opposite to each other, respectively; and

two emission surfaces which are disposed so as to face each other with the two reflection surfaces interposed therebetween and which emit the light reflected by the two reflection surfaces to the outside,

the incident surface has: an interior top surface of the recess; and two inner side surfaces arranged in a direction in which the two emission surfaces face each other with the inner top surface of the recess interposed therebetween,

a plurality of first ribs having ridge lines substantially parallel to a direction in which the two emission surfaces face each other when viewed along an optical axis of the light emitting element are arranged on the inner top surface,

the height of the first ridge in a cross section perpendicular to the ridge line of the first ridge becomes lower as the first ridge approaches the two emission surfaces.

2. A light flux controlling member for controlling distribution of light emitted from a light emitting element, comprising:

an incident surface which is arranged on the inner surface of the concave part on the back surface side and is provided with a concave partThe incident surfaceMaking light emitted from the light emitting element incident;

two reflecting surfaces which are arranged on a front surface side and reflect a part of light incident from the incident surface in two directions which are substantially perpendicular to an optical axis of the light emitting element and are opposite to each other, respectively; and

two emission surfaces which are disposed so as to face each other with the two reflection surfaces interposed therebetween and which emit the light reflected by the two reflection surfaces to the outside,

a plurality of second ribs having ridge lines substantially parallel to the optical axis of the light emitting element when viewed in a direction in which the two emission surfaces face each other are arranged on each of the two emission surfaces,

the height of the second ridge in a cross section perpendicular to the ridge line of the second ridge becomes lower as it approaches the back surface side.

3. The light beam steering section of claim 1,

a plurality of second ribs having ridge lines substantially parallel to the optical axis of the light emitting element when viewed in a direction in which the two emission surfaces face each other are arranged on each of the two emission surfaces,

the height of the second ridge in a cross section perpendicular to the ridge line of the second ridge becomes lower as it approaches the back surface side.

4. The light beam control member according to any one of claims 1 to 3,

a plurality of third ridges having ridgelines substantially perpendicular to a direction in which the two emission surfaces face each other when viewed along the optical axis of the light emitting element are arranged on at least a portion of each of the two reflection surfaces.

5. The light beam steering section of claim 1,

in the ridge line direction of the first ridge line, the inclination of the ridge line of the first ridge line is constant.

6. The beam steering section of claim 2,

in the ridge line direction of the second ridge line, the inclination of the ridge line of the second ridge line is constant.

7. The light beam steering section of claim 1,

the width of the first ridge in a cross section perpendicular to the ridge line of the first ridge becomes smaller as approaching the emission surface.

8. The beam steering section of claim 2,

the width of the second ridge in a cross section perpendicular to the ridge line of the second ridge becomes smaller as approaching the back surface side.

9. A light-emitting device, comprising:

a light emitting element; and

the light flux controlling member according to any one of claims 1 to 8, wherein the incident surface is disposed to face the light emitting element.

10. The light emitting device of claim 9,

light emitted from the light emission center of the light emitting element at an angle of at least 0 ° or more and 10 ° or less with respect to the optical axis of the light emitting element is incident on the incident surface.

11. An illumination device, comprising:

a plurality of the light emitting devices of claim 9 or 10; and

a light diffusion plate diffusing and transmitting light emitted from the light emitting device.

Technical Field

The invention relates to a light flux controlling member, a light emitting device and a lighting device.

Background

As a light source of a lighting device, a signboard, or the like, a light-emitting device having a light-emitting element such as an LED is used. In particular, as a light source of a channel letter signboard or the like having a special shape, a light emitting device is used which reflects light emitted from a light emitting element in two directions opposite to each other in a horizontal direction and has anisotropic light distribution characteristics (exhibits an elliptical light distribution).

As a light emitting device having anisotropic light distribution characteristics, for example, patent document 1 discloses a light emitting device including, as shown in fig. 1: a light emitting element 12; a base (a lead base for mounting a chip) 14 having a reflecting cup 14a, the reflecting cup 14a reflecting light emitted from the light emitting element 12 upward; and light flux controlling member 13 (translucent resin in patent document 1) for sealing light emitting element 12 and reflector cup 14 a. Light flux controlling member 13 has: two reflecting surfaces 17 for reflecting light emitted from the light emitting element 12 or light reflected by the reflecting cup 14 a; and two light emitting surfaces 19 (side surfaces in patent document 1) for emitting the light reflected by the reflecting surface 17 to the outside.

In such a light emitting device, light emitted from the upper surface of light emitting element 12 directly reaches reflection surface 17 of light flux controlling member 13, and light emitted from the side surface of light emitting element 12 is reflected by reflection cup 14a and then reaches two reflection surfaces 17 of light flux controlling member 13. The light beams that have reached two reflecting surfaces 17 of light flux controlling member 13 travel in directions opposite to each other in the horizontal direction, and are emitted from two emission surfaces 19 of light flux controlling member 13 to the outside.

Light-emitting elements such as LEDs are used as light-emitting elements used in such light-emitting devices. Most of LEDs that are mass-produced at low cost include, for example, a light-emitting portion that emits blue light and a light-emitting element (SMD type light-emitting element) that covers the periphery of the light-emitting portion and that converts the blue light emitted from the light-emitting portion into white light.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 9-18058

Disclosure of Invention

Problems to be solved by the invention

In the SMD type light emitting element, blue light emitted at a large angle with respect to the optical axis of the light emitting element propagates through a long optical path in the phosphor and is emitted, and therefore is easily converted into white light. On the other hand, since blue light emitted at a small angle with respect to the optical axis of the light-emitting element propagates through the phosphor in a short optical path and is emitted, the blue light is not easily converted into white light and is easily emitted as blue light. In addition to the SMD-type light emitting element, when a light emitting element that emits light of a different color tone depending on an emission direction is applied to a light emitting device having anisotropic light distribution characteristics as shown in patent document 1, there is a problem as follows: color unevenness is likely to occur between a region where light emitted at a small angle with respect to the optical axis of the light-emitting element reaches and a region where light emitted at a large angle with respect to the optical axis reaches. Specifically, there are the following problems: light emitted at a small angle with respect to the optical axis of the light emitting element easily reaches a specific region of the light diffusion plate in a concentrated manner, and blue color easily appears in the region.

On the other hand, in order to suppress color unevenness, the light distribution characteristics tend to be impaired. Therefore, it is desirable to suppress color unevenness without impairing the light distribution characteristics (maintaining the light distribution characteristics at a high level).

Accordingly, an object of the present invention is to provide a light flux controlling member capable of suppressing color unevenness caused by a light emitting element while maintaining a desired light distribution characteristic. Another object of the present invention is to provide a light-emitting device and a lighting device including the light flux controlling member.

Means for solving the problems

A light flux controlling member according to the present invention is a light flux controlling member for controlling distribution of light emitted from a light emitting element, including: an incident surface which is arranged on the inner surface of the concave part on the back surface side and is provided with a concave partThe incident surfaceMaking light emitted from the light emitting element incident; two reflecting surfaces which are arranged on a front surface side and reflect a part of light incident from the incident surface in two directions which are substantially perpendicular to an optical axis of the light emitting element and are opposite to each other, respectively; and two emission surfaces that are arranged to face each other with the two reflection surfaces interposed therebetween and that emit the light reflected by the two reflection surfaces to the outside, respectively, wherein the incident surface includes: an interior top surface of the recess; and two inner side surfaces that are arranged in a direction in which the two emission surfaces face each other with an inner top surface of the concave portion interposed therebetween, wherein the inner top surface is provided with a plurality of first ridges that have ridge lines that are substantially parallel to the direction in which the two emission surfaces face each other when viewed along an optical axis of the light-emitting element, and wherein a height of the first ridges in a cross section perpendicular to the ridge lines of the first ridges decreases as the first ridges approach the two emission surfaces.

A light flux controlling member according to the present invention is a light flux controlling member for controlling distribution of light emitted from a light emitting element, including: an incident surface which is arranged on the inner surface of the concave part on the back surface side and is provided with a concave partThe incident surfaceMaking light emitted from the light emitting element incident; two reflecting surfaces which are arranged on a front surface side and reflect a part of light incident from the incident surface in two directions which are substantially perpendicular to an optical axis of the light emitting element and are opposite to each other, respectively; and two emission surfaces which are arranged to face each other with the two reflection surfaces interposed therebetween, and which emit the light reflected by the two reflection surfaces to the outside, respectively, and the light emitted from the two emission surfacesEach of the second ribs has a ridge line substantially parallel to the optical axis of the light emitting element when viewed in a direction in which the two emission surfaces face each other, and a height of the second rib in a cross section perpendicular to the ridge line of the second rib becomes lower as approaching the back surface side.

The light emitting device of the present invention includes: a light emitting element; and a light flux controlling member of the present invention, wherein the incident surface is disposed to face the light emitting element.

The lighting device of the present invention includes: a plurality of light emitting devices of the present invention; and a light diffusion plate diffusing and transmitting light emitted from the light emitting device.

Effects of the invention

According to the present invention, it is possible to provide a light flux controlling member capable of suppressing color unevenness caused by a light emitting element while maintaining a desired light distribution characteristic.

Drawings

Fig. 1 is a diagram showing a structure of a conventional light-emitting device.

Fig. 2A and 2B are diagrams showing the configuration of the lighting device according to embodiment 1.

Fig. 3 is a plan view of the lighting device with the light diffusion plate removed.

Fig. 4A to 4C are diagrams showing the configuration of the periphery of the light-emitting device shown in fig. 3.

Fig. 5A to 5D are diagrams showing the configuration of a light flux controlling member according to embodiment 1.

Fig. 6A is a sectional view taken along line a-a of the first ceiling surface of fig. 5C, and fig. 6B is a sectional view taken along line B-B of the first ceiling surface of fig. 5C.

Fig. 7 is a graph showing a cross-sectional shape of the first inner top surface in a cross section perpendicular to the ridge line of the first ridge.

Fig. 8A to 8C are views showing modifications of the cross-sectional shape of the first inner ceiling surface in a cross section perpendicular to the ridge line of the first ridge.

Fig. 9A to 9F are views showing modifications of the cross-sectional shape of the first inner ceiling surface in the cross section perpendicular to the ridge line of the first ridge.

Fig. 10A is a graph showing the analysis result of the illuminance distribution on the light diffusion plate of the illumination apparatus using the light flux controlling member of embodiment 1 and the analysis result of the illuminance distribution on the light diffusion plate of the illumination apparatus using the light flux controlling member for comparison, and fig. 10B is a graph showing the analysis result of the chromaticity Y value on the light diffusion plate of the illumination apparatus using the light flux controlling member of embodiment 1 and the analysis result of the chromaticity Y value on the light diffusion plate of the illumination apparatus using the light flux controlling member for comparison.

Fig. 11A to 11D are diagrams showing the configuration of a light flux controlling member according to embodiment 2.

Fig. 12A is a sectional view taken along line a-a of the exit surface of fig. 11D, and fig. 12B is a sectional view taken along line B-B of the exit surface of fig. 11D.

Fig. 13A to 13C are views showing modified examples of the sectional shape of the light emission surface in a cross section perpendicular to the ridge line of the second ridge.

Fig. 14A to 14F are views showing modifications of the cross-sectional shape of the light emission surface in a cross section perpendicular to the ridge line of the second ridge.

Fig. 15A is a graph showing the analysis result of the illuminance distribution on the light diffusion plate of the illumination apparatus using the light flux controlling member of embodiment 2 and the analysis result of the illuminance distribution on the light diffusion plate of the illumination apparatus using the light flux controlling member for comparison, and fig. 15B is a graph showing the analysis result of the chromaticity Y value on the light diffusion plate of the illumination apparatus using the light flux controlling member of embodiment 2 and the analysis result of the chromaticity Y value on the light diffusion plate of the illumination apparatus using the light flux controlling member for comparison.

Fig. 16A to 16D are diagrams showing the structure of a light flux controlling member according to embodiment 3.

Fig. 17A is a sectional view taken along line a-a of the first ceiling surface of fig. 16C, and fig. 17B is a sectional view taken along line B-B of the first ceiling surface of fig. 16C.

Fig. 18A is a graph showing the sectional shape of the reflection surface of the light flux controlling member in a cross section perpendicular to the ridge line of the third ridge, and fig. 18B is a graph showing the result (Δ h1) of subtracting the design value of the sectional shape of the reflection surface of the light flux controlling member without the third ridge from the design value of the sectional shape of the reflection surface of the light flux controlling member with the third ridge in a cross section perpendicular to the ridge line of the third ridge.

Fig. 19A is a graph showing the analysis result of the illuminance distribution on the light diffusion plate of the illumination apparatus using the light flux controlling member of embodiment 3 and the analysis result of the illuminance distribution on the light diffusion plate of the illumination apparatus using the light flux controlling member for comparison, and fig. 19B is a graph showing the analysis result of the chromaticity Y value on the light diffusion plate of the illumination apparatus using the light flux controlling member of embodiment 3 and the analysis result of the chromaticity Y value on the light diffusion plate of the illumination apparatus using the light flux controlling member for comparison.

Fig. 20 is a partially enlarged perspective view showing a configuration of a lighting device according to a modification.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the drawings.

[ embodiment 1]

(Structure of Lighting device)

Fig. 2A, 2B, and 3 are diagrams illustrating a configuration of an illumination device 100 according to embodiment 1. Fig. 2A is a plan view of the lighting device 100, and fig. 2B is a front view. Fig. 3 is a plan view of the illumination device 100 according to the present embodiment with the light diffusion plate 150 removed. Fig. 4A to 4C are diagrams illustrating the configuration around the light-emitting device 130 illustrated in fig. 3. Fig. 4A is a perspective view of the periphery of the light emitting device 130 shown in fig. 3, fig. 4B is a plan view of fig. 4A, and fig. 4C is a cross-sectional view taken along line 4C-4C of fig. 4B. The lighting device 100 shown in the figure is used as a channel letter signboard, for example.

As shown in fig. 2A, 2B, and 3, the lighting device 100 includes: a case 110, a plurality of substrates 120 (not shown), a plurality of light emitting devices 130, a cable 140, and a light diffusion plate 150.

The case 110 is a box-like body having at least a part of one surface opened for accommodating the plurality of substrates 120 and the plurality of light emitting devices 130 therein. In the present embodiment, the housing 110 includes: the bottom plate, with the relative roof of bottom plate, four curb plates of connecting bottom plate and roof. An opening portion serving as a light emitting region is formed in the top plate. The opening is covered with a light diffusion plate 150. The bottom plate is disposed parallel to the top plate. The height (spatial thickness) from the surface of the base plate to the light diffusion plate 150 is not particularly limited, but is preferably about 20 to 100 mm. The case 110 is made of resin such as polymethyl methacrylate (PMMA) and Polycarbonate (PC), metal such as stainless steel and aluminum, or the like.

The shape of the case 100 in plan view may be any shape. In the present embodiment, since the housing is used for a channel sign or the like, the planar shape of the housing 100 is an S-shape.

The plurality of substrates 120 are flat plates for disposing the plurality of light emitting devices 130 at predetermined intervals on the bottom plate of the case 110 (see fig. 4C). In the present embodiment, the substrate 120 is disposed on the bottom plate of the housing 110 via a caulking member 141 (see fig. 4C). The wiring of the substrate 120 is electrically connected by a cable 140.

The light emitting devices 130 are disposed on the bottom plate of the housing 110 through the substrates 120. The number of the light emitting devices 130 disposed on the bottom plate of the housing 110 is not particularly limited. The number of light emitting devices 130 arranged on the bottom plate of the housing 110 is appropriately set based on the size of a light emitting region (light emitting surface) defined by the opening of the housing 110.

Each of the plurality of light emitting devices 130 has a light emitting element 131 and a light flux controlling member 132. Each of the plurality of light-emitting devices 130 is arranged such that an optical axis of light emitted from the light-emitting element 131 (an optical axis LA of the light-emitting element 131 described later) is along a normal line with respect to the surface of the substrate 120.

The light emitting element 131 is a light source of the lighting apparatus 100 (and the light emitting apparatus 130). The light-emitting element 131 is disposed on the substrate 120 (see fig. 4C), and is electrically connected to a wiring formed on the substrate 120 or in the substrate 120.

The light emitting element 131 is, for example, a Light Emitting Diode (LED). The color of the outgoing light of the light emitting element 131 included in the light emitting device 130 is not particularly limited. In this embodiment, an SMD type light emitting element having: for example, a light emitting section that emits blue light and a phosphor that covers the periphery thereof and converts the blue light emitted from the light emitting section into white light.

Light flux controlling member 132 controls the distribution of light emitted from light emitting element 131 to change the traveling direction of the light to a direction along the surface of substrate 120, in particular, two directions that are substantially perpendicular to and opposite to optical axis LA of light emitting element 131. Light flux controlling member 132 is disposed such that incident surface 133 faces light emitting element 131, specifically, such that central axis CA thereof coincides with optical axis LA of light emitting element 131 (see fig. 4C). The "optical axis LA of the light emitting element 131" refers to a light ray from the center of the three-dimensional outgoing light flux from the light emitting element 131. "central axis CA of light flux controlling member 132" means, for example, a symmetry axis of two-fold symmetry.

Hereinafter, in each light-emitting device 130, a direction passing through the light-emission center of the light-emitting element 131 and parallel to the optical axis LA of the light-emitting element 131 is referred to as a Z-axis direction, and two directions orthogonal to each other in a plane perpendicular to the Z-axis direction are referred to as an X-axis direction and a Y-axis direction. Specifically, in light flux controlling member 132 described later, the direction in which two emission surfaces 135 described later face each other is referred to as the Y-axis direction, and the direction orthogonal to the Y-axis direction in a plane perpendicular to the Z-axis direction is referred to as the X-axis direction.

The material of light flux controlling member 132 is not particularly limited as long as it is a material that can pass light of a desired wavelength. For example, the material of light flux controlling member 132 is a light-transmitting resin such as polymethyl methacrylate (PMMA), Polycarbonate (PC), or epoxy resin (EP), or glass.

The main feature of illumination device 100 of the present embodiment is the structure of light flux controlling member 132. Accordingly, with respect to light flux controlling member 132, additional details will be provided.

The cables 140 electrically connect adjacent plural substrates 120 to each other. The connection part between the substrate 120 and the cable 140 is reinforced by the caulking member 141 (see fig. 4C). Examples of the material of the caulking part 141 include: polyurethane resin, silicone resin, epoxy resin.

In this way, the plurality of light emitting devices 130 are electrically connected via the cable 140 to be modularized, so that the plurality of light emitting devices 130 can be freely arranged according to the shape of the housing 110.

The light diffusion plate 150 is disposed so as to cover the opening of the housing 110 (see fig. 2A and 2B). Light diffusion plate 150 is a plate-like member having light permeability and light diffusion properties, and diffuses and transmits light emitted from emission surface 135 (see fig. 5) of light flux controlling member 132. The light diffusion plate 150 can serve as, for example, a light emitting surface of the lighting device 100.

The material of light diffusion plate 150 is not particularly limited as long as it can diffuse and transmit the light emitted from emission surface 135 of light flux controlling member 132, and examples thereof include light-transmitting resins such as polymethyl methacrylate (PMMA), Polycarbonate (PC), Polystyrene (PS), and styrene-methyl methacrylate copolymer resin (MS). In order to impart light diffusion properties, fine irregularities are formed on the surface of the light diffusion plate 150, or light diffusers such as beads are dispersed inside the light diffusion plate 150.

In illumination device 100 of the present embodiment, light emitted from each light emitting element 131 is changed by light flux controlling member 132 to be emitted in two directions (Y-axis directions in fig. 4A to 4C) opposite to each other, in particular, in a direction substantially perpendicular to optical axis LA of light emitting element 131, so as to irradiate a wide range of light diffusion plate 150. The light emitted from each light flux controlling member 132 is further diffused by the light diffusion plate 150 and emitted to the outside. This can suppress color unevenness and illuminance unevenness of the illumination device 100. (Structure of light flux controlling Member)

Fig. 5A to 5D are diagrams showing the structure of light flux controlling member 132. Fig. 5A is a top view of light flux controlling member 132, fig. 5B is a cross-sectional view taken along line 5B-5B of fig. 5A, fig. 5C is a bottom view, and fig. 5D is a side view. Fig. 6A is a sectional view taken along line a-a of the first interior top surface 133a of fig. 5C, and fig. 6B is a sectional view taken along line B-B of the first interior top surface 133a of fig. 5C.

Light flux controlling member 132 controls the distribution of light emitted from light emitting element 131. As shown in fig. 5A to 5D, light flux controlling member 132 has incident surface 133, two reflection surfaces 134, two emission surfaces 135, flange 136, and two leg portions 137. Hereinafter, the side of light flux controlling member 132 on which the incident surface is formed (light emitting element 131 side) is referred to as the back side, and the side on which reflection surface 134 is formed is referred to as the front side.

The incident surface 133 allows a part of the light emitted from the light emitting element 131 to enter. Incident surface 133 is an inner surface of concave portion 139 formed in the center of bottom surface 138, which is the rear surface side of light flux controlling member 132. The inner surface of the concave portion 139 is not particularly limited, and may be a surface having an edge or a curved surface having no edge, such as a hemispherical shape or a semi-elliptical shape. In the present embodiment, the inner surface of the concave portion 139 has a ribbed shape.

Specifically, the inner surface (incidence surface 133) of the recess 139 has at least a first inner top surface 133a (inner top surface) and two inner side surfaces 133B, and further has two second inner top surfaces 133C, two third inner top surfaces 133d, and two fourth inner top surfaces 133e therebetween (see fig. 5B and 5C). The two second inner top surfaces 133c, the two third inner top surfaces 133d, and the two fourth inner top surfaces 133e are disposed so as to sandwich the first inner top surface 133a in a direction (Y-axis direction) in which the two emission surfaces 135 face each other.

The first inner top surface 133a is a surface disposed at the center of the concave portion 139 so as to intersect the optical axis LA of the light emitting element 131. The first inner top surface 133a is preferably formed so that light emitted from the light emission center of the light emitting element 131 enters at least 0 ° and 10 ° with respect to the optical axis LA of the light emitting element 131. In addition, from the viewpoint of preventing light emitted at a small angle with respect to the optical axis LA of the light-emitting element 131 from traveling to the boundary portion between the two reflecting surfaces 134, the first inner top surface 133a is preferably formed so as to have a height from the light-emitting surface of the light-emitting element 131 higher as the optical axis LA of the light-emitting element 131 approaches. On the first inner top surface 133a, a plurality of first convex stripes 142 are arranged to suppress color unevenness caused by the light emitting elements 131 (see fig. 5C).

The first ribs 142 are arranged such that the ridge lines of the first ribs 142 are substantially parallel to the direction (Y-axis direction) in which the two emission surfaces 135 face each other when viewed along the optical axis LA of the light-emitting element 131 (when viewed along the Z-axis direction). The direction (Y-axis direction) in which the ridges of the first ridges 142 face each other substantially parallel to the two emission surfaces 135 means that the angle formed by the ridges of the first ridges 142 and the direction (Y-axis direction) in which the two emission surfaces 135 face each other when viewed along the Z-axis direction is 15 ° or less, preferably 0 °. That is, the direction in which the ridges of the first ribs 142 extend does not necessarily have to coincide with the Y-axis direction. The plurality of first ribs 142 may be formed so as to extend from the boundary portion between the two reflection surfaces 134 (or a virtual plane (XZ plane including the X axis and the Z axis) set between the two reflection surfaces 134 and including the optical axis LA) to each of the two emission surfaces 135 without intersecting each other.

The cross-sectional shape of the first ridge 142 in a cross section perpendicular to the ridge line of the first ridge 142 is not particularly limited, and may be triangular, rectangular (including trapezoidal), semicircular, semielliptical, or wavy. In the present embodiment, the cross-sectional shape of the first ridge 142 in a cross section perpendicular to the ridge line of the first ridge 142 is triangular (see fig. 6A and 6B).

The "ridge line" in the first convex stripes 142 means a linear connection of the highest portions (tops) of the convex stripes, and means a line connecting the apexes of the first convex stripes 142 in a cross section parallel to the X-axis direction and including the optical axis LA of the light-emitting element 131. The "ridge" of the first projecting strip 142 may be one for each first projecting strip 142, or may be two or more. For example, when the cross-sectional shape of the first ridges 142 is a wave shape, a line connecting the peaks of the wave becomes a ridge line. When the cross-sectional shape of the first ridge 142 is a trapezoid, a line connecting one point of two apexes (intersection points of the upper base and the waist) of the trapezoid and a line connecting the other point are ridge lines, respectively.

Fig. 7 is a graph showing the cross-sectional shape of the first inner top surface 133a in a cross section perpendicular to the ridge line of the first ridge 142. In fig. 7, the horizontal axis represents a distance d1 (distance in the X-axis direction; mm) from the center of the first ceiling surface 133a, and the vertical axis represents a height h1 (height in the Z-axis direction; mm) from the reference plane of the first ceiling surface 133 a. The reference plane is a line connecting the apexes of the first ridges 142 and the midpoints between the valleys adjacent thereto in a cross section perpendicular to the ridges of the first ridges 142.

In a cross section perpendicular to the ridge line of the first ridge 142, the distances a (distances in the X-axis direction) between the centers of the plurality of first ridges 142 may be the same or different. From the viewpoint of achieving a desired light distribution and suppressing color unevenness, it is preferable that the center-to-center distances a of the plurality of first convex strips 142 are the same. The "distance a between the centers of the first ribs 142" refers to a distance between the center lines of the first ribs 142 (see fig. 7).

In a cross section perpendicular to the ridge line of the first ridge 142, the heights b (lengths in the Z-axis direction) of the plurality of first ridges 142 may be the same or different. From the viewpoint of achieving a desired light distribution and suppressing color unevenness, the heights b of the plurality of first ridges 142 are preferably the same. The "height b of the first ridge 142" is a length corresponding to half of a distance between a straight line connecting apexes of two adjacent first ridges 142 and a straight line connecting a valley bottom of a recess formed between the two first ridges 142 and a valley bottom of two recesses formed on both sides of the recess in a cross section perpendicular to the ridge line of the first ridge 142 (see fig. 7).

Preferably, a ratio of the distance a between centers of the plurality of first ribs 142 to the height b in a cross section perpendicular to the ridge line of the first ribs 142 is a: b is 1: 0-1: 0.5. if a: when b is within the above range, the traveling direction of the light incident from the first inner ceiling surface 133a can be easily changed slightly without largely affecting the illuminance distribution on the light diffusion plate 150, and thus, desired light distribution can be easily achieved and color unevenness can be suppressed. In view of improving the effect of color unevenness, the processing accuracy of the mold, and the transferability of the light flux controlling member during molding, the center-to-center distance a between the plurality of first ridges 142 is preferably 0.1mm or more and 1mm or less.

The height B of the first ridge 142 in a cross section perpendicular to the ridge line of the first ridge 142 becomes lower as the distance from the two emission surfaces 135 approaches (see fig. 5C, 6A, and 6B). That is, light emitted from the light emission center of the light emitting element 131 at a small angle with respect to the optical axis LA of the light emitting element 131, particularly light incident from the vicinity of the center of the first inner top surface 133a, greatly contributes to color unevenness. Therefore, by increasing the height b of the first ridge 142 on the center side of the first inner top surface 133a in the ridge line direction of the first ridge 142, the traveling direction of the incident light can be easily changed. On the other hand, light emitted from the light emission center of light-emitting element 131 at a large angle with respect to optical axis LA of light-emitting element 131, for example, light incident from the side closer to emission surface 135 in first inner top surface 133a contributes less to color unevenness. Therefore, by decreasing the height b of the first ridge 142 on the nearer side from the two emission surfaces 135 in the ridge line direction of the first ridge 142, the traveling direction of the incident light can be changed without being changed more than necessary. This can suppress color unevenness on the light emitting surface of the illumination device 100, and the light distribution characteristics of the light emitting device 130 are less likely to be impaired (see fig. 6A and 6B).

The height b of the first protrusion 142 may be linearly or curvilinearly decreased as it approaches the two emission surfaces 135. The linearly lower is that the inclination of the ridge of the first ridge 142 is constant regardless of the position in the ridge direction of the first ridge 142; the curved lower portion means that the inclination of the ridge of the first ridge 142 changes depending on the position in the ridge direction of the first ridge 142. Specifically, the inclination of the ridge of the first ridge 142 is the inclination of the ridge in the cross section including the ridge of the first ridge 142. When the ridge line in the cross section including the ridge line of the first ridge 142 is a curve, the inclination of the ridge line at each position refers to the inclination of the tangent to the curve at the position. In the present embodiment, the height b of the first protrusion 142 linearly decreases as it approaches the two emission surfaces 135.

The region where the height b of the first ridge 142 decreases as the first ridge approaches the two emission surfaces 135 may be the entire region in the ridge line direction of the first ridge 142 or a partial region. In the present embodiment, the regions where the height b of the first ribs 142 decreases as the first ribs approach the two emission surfaces 135 are all the regions in the ridge line direction of the first ribs 142.

Two reflection surfaces 134 are disposed on the front surface side of light flux controlling member 132, that is, on the side opposite to light emitting element 131 (on the side of light diffusion plate 150) with incidence surface 133 interposed therebetween. The two reflecting surfaces 134 reflect a part of the light incident from the incident surface 133 in two directions (directions in which the two emission surfaces 135 face each other, that is, Y-axis directions) substantially perpendicular to the optical axis LA of the light emitting element 131 and opposite to each other. The two reflecting surfaces 134 are arranged such that, in a cross section including the optical axis LA of the light-emitting element 131 and parallel to the Y-axis direction, the height from the bottom surface 138 (substrate 120) increases as going from the end portion (emission surface 135) of the optical axis LA of the light-emitting element 131 to the boundary with the optical axis LA of the light-emitting element 131. Specifically, in the cross section, the two reflecting surfaces 134 are formed such that the inclination of the tangent line gradually decreases as the distance from the optical axis LA of the light emitting element 131 to the end (the emission surface 135) decreases.

The two emission surfaces 135 are disposed opposite to each other (in the Y-axis direction) with the two reflection surfaces 134 interposed therebetween. The two emission surfaces 135 respectively emit light that has been incident on the incident surface 133 (particularly, the two inner side surfaces 133b) and has directly reached the emission surface 135 and light that has been incident on the incident surface 133 (particularly, the first inner top surface 133a) and has been reflected by the two reflection surfaces 134 to the outside.

The exit surface 135 may be a flat surface or a curved surface. In the present embodiment, the emission surface 135 is a surface substantially parallel to the optical axis LA. "substantially parallel to the optical axis LA" means that a smaller angle of angles formed by the optical axis LA and the emission surface 135 is 3 ° or less in a cross section including the optical axis LA and parallel to the Y-axis direction. Note that, in the case where the emission surface 135 is a curved surface, a smaller angle of the angles formed by the optical axis LA and the emission surface 135 means a smaller angle of the angles formed by the optical axis LA and the tangent line of the curve in the cross section of the emission surface 135 in the cross section.

Flange 136 is located between both emission surfaces 135 and the outer peripheral portion of bottom surface 138 of light flux controlling member 132, and protrudes outward with respect to central axis CA. The flange 136 is substantially rectangular in shape. Flange 136 is not an essential component, but by providing flange 136, handling and alignment of light flux controlling member 132 are facilitated. The thickness of the flange 136 is not particularly limited, and may be determined in consideration of the area required for the two emission surfaces 135, the ease of molding the flange 136, and the like.

Two leg portions 137 are substantially columnar members protruding from bottom surface 138 and the bottom of flange portion 136 toward light emitting element 131 at the outer periphery of bottom surface 138 (rear surface) of light flux controlling member 132. Two leg portions 137 support light flux controlling member 132 at appropriate positions with respect to light emitting element 131 (see fig. 4C). The leg portion 137 may be fitted in a hole portion formed in the substrate 120 for positioning in a direction parallel to the XY plane. The number of the leg portions 137 is not particularly limited.

(action)

The operation of light flux controlling member 132 of the present embodiment will be described in comparison with a comparative light flux controlling member. The comparative flux control member is configured in the same manner as the flux control member according to the present embodiment except that the first inner top surface 133a does not have the plurality of first ridges 142.

In comparative light flux controlling member (not shown) and light flux controlling member 132 of the present embodiment, light emitted from light emitting element 131 is incident on incident surface 133, and a part of the light is reflected by two reflecting surfaces 134, travels in two directions perpendicular to optical axis LA of light emitting element 131 and opposite to each other, and is then emitted to the outside from two emission surfaces 135. The light emitted from the emission surface 135 is controlled so as to reach a position of the light diffusion plate 150 distant from the light emitting device 130 (see fig. 4C and 5B).

In the comparative light flux controlling member, first inner top surface 133a is a smooth surface. Therefore, light emitted at a small angle with respect to the optical axis LA of the light-emitting element 131 (for example, light emitted at an angle of at least 0 ° or more and 10 ° or less with respect to the optical axis LA of the light-emitting element 131 from the light-emission center of the light-emitting element 131) is incident from a smooth surface, and therefore the traveling direction is not disturbed, and the light easily reaches a specific region of the light diffusion plate 150 in a concentrated manner. As a result, blue from a specific region of the light-emitting element 131 is more easily conspicuously displayed than in other regions, and color unevenness is likely to occur.

In contrast, in light flux controlling member 132 of the present embodiment, a plurality of first ridges 142 having ridges substantially parallel to the Y-axis direction are arranged on first inner top surface 133a (see fig. 5C), and the height of first ridges 142 decreases as it approaches emission surface 135 (see fig. 6A and 6B).

Accordingly, the traveling direction of light emitted from the light-emitting center of the light-emitting element 131 at a small angle with respect to the optical axis LA of the light-emitting element 131, particularly light incident from the vicinity of the center of the first inner ceiling surface 133a (light having a large contribution to color unevenness), is sufficiently changed by the first convex stripes 142, and thus, it is difficult to intensively reach a specific region of the light diffusion plate 150. On the other hand, light emitted from the light emission center of light-emitting element 131 at a large angle with respect to optical axis LA of light-emitting element 131, for example, light incident from the vicinity of the end portions on the side of both emission surfaces 135 (light with a small contribution to color unevenness), is not likely to be impaired in light distribution characteristics because the traveling direction of light is not changed more than necessary by first ridges 142. This can suppress color unevenness on the light emitting surface of the illumination device 100, and further reduce the light distribution characteristics of the light emitting device 130.

In embodiment 1, an example is shown in which the width (size in the X-axis direction) of the first ridge 142 is constant in the ridge line direction of the first ridge 142 in a cross section perpendicular to the ridge line of the first ridge 142 (see fig. 5C, 6A, and 6B), but the present invention is not limited thereto, and may not be constant. That is, the width (size in the X-axis direction) of the first ridge 142 in the cross section perpendicular to the ridge line of the first ridge 142 may be different between the cross section along line a-a and the cross section along line B-B.

Fig. 8A to 8C are views showing modifications of the cross-sectional shape of the first inner top surface 133a in a cross section perpendicular to the ridge line of the first ridge 142. As shown in fig. 8A to 8C, in a cross section perpendicular to the ridge line of the first ridge 142, the width C (the size in the X-axis direction) of the first ridge 142 may be decreased as approaching the emission surface 135. Accordingly, the die can be processed so that the apex angles of the first ridges 142 are the same size, and thus the die can be easily manufactured. Note that, in a cross section perpendicular to the ridge line of the first ridge 142, the center-to-center distance a of the plurality of first ridges 142 is constant (see fig. 8A to 8C).

In embodiment 1, the example in which the cross-sectional shape of the first ridge 142 in the cross section perpendicular to the ridge line of the first ridge 142 is a triangle as shown in fig. 6A and 6B is shown, but the present invention is not limited thereto.

Fig. 9A to 9F are views showing modifications of the cross-sectional shape of the first inner top surface 133a in a cross section perpendicular to the ridge line of the first ridge 142. That is, the cross-sectional shape of the first ridge 142 in a cross section perpendicular to the ridge line of the first ridge 142 may be semicircular or semielliptical (see fig. 9A and 9B, 9E, and 9F), or may be wavy (see fig. 9C and 9D).

(simulation 1)

Illumination distribution and chromaticity Y values on light diffusion plate 150 of illumination apparatus 100 using light flux controlling member a-1 (fig. 5C, 6A, and 6B) or a-2 (fig. 8A to 8C) according to the present embodiment were analyzed. The illuminance distribution and chromaticity Y value were analyzed using the lighting apparatus 100 having only one light-emitting device 130.

For comparison, the illuminance distribution and chromaticity Y value on the light diffusion plate of the illumination apparatus using the following light flux controlling member (comparison) were also analyzed: the first inner top surface 133a of the light flux controlling member (comparative) is the same as the light flux controlling member A-1 or A-2 except that it has no convex stripes.

The parameters of the beam control sections A-1 and A-2 are set as follows.

< parameters of the first interior top surface 133a >

In a cross section perpendicular to the ridge line of the first ridge 142, the cross-sectional shape of the first ridge 142 is triangular. The center-to-center distances a and heights b of the plurality of first ridges 142 in a cross section perpendicular to the ridge line of the first ridge 142 are set as follows.

Beam control unit a-1:

distance a between centers: height b is 1: 0.14(A-A line section)

The center-to-center distance a is 500 μm and the height b is 72 μm

The height B of the first ridge 142 is set to be gradually lower as approaching the emission surface 135 in the Y-axis direction, and the height B in the cross section of the line B-B approaches 0 μm.

Light flux controlling Member A-2

Distance a between centers: height b is 1: 0.14(A-A line section)

The center-to-center distance a is 500 μm and the height b is 72 μm

The height B of the first ridge 142 is set to be gradually lower as approaching the emission surface 135 in the Y-axis direction, and the height B in the cross section of the line B-B approaches 0 μm. The width of the first ridge 142 is also set so that the width in the cross section of the line B-B approaches 0 μm, gradually decreasing toward the emission surface 135 in the Y-axis direction.

< other common parameters >

Outer diameter of light flux controlling member 132: length 11.1mm in Y-axis direction and length 9.2mm in X-axis direction

Height of light-emitting element 131: 0.75mm

Size of light-emitting element 131:

spacing between the substrate 120 and the light diffusion plate 150: 50mm

Fig. 10A is a graph showing the analysis result of the illuminance distribution on the light diffusion plate of the illumination device of the present embodiment and the analysis result of the illuminance distribution on the light diffusion plate of the illumination device for comparison. The horizontal axis of fig. 10A represents the distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light-emitting element 131 on the light diffusion plate 150, and the vertical axis represents the relative illuminance when the maximum illuminance at each distance on the light diffusion plate 150 is 1.

Fig. 10B is a graph showing the analysis result of the chromaticity Y value on the light diffusion plate of the illumination device of the present embodiment and the analysis result of the chromaticity Y value on the light diffusion plate of the illumination device for comparison. The horizontal axis of fig. 10B represents the distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light-emitting element 131 on the light diffusion plate 150, and the vertical axis represents the chromaticity Y value on the light diffusion plate 150.

As shown in fig. 10A, it is understood that the light distribution characteristics are highly maintained in the illuminance distribution of the illumination device using light flux controlling member a-1 or a-2 according to the present embodiment, with the spread of light in the Y-axis direction being equivalent to the illuminance distribution of the illumination device using the comparative light flux controlling member.

As shown in fig. 10B, in the illumination device using the comparative light flux controlling member, while the chromaticity difference between the valley bottom portion of the distance d2 from the optical axis LA of the light emitting element 131 in the vicinity of 40mm (specific region) and the top portion adjacent thereto (see the arrow in fig. 10B) is large, and the chromaticity difference between the valley bottom portion of the distance d2 from the optical axis LA of the light emitting element 131 in the vicinity of 40mm and the top portion adjacent thereto is small, and the color unevenness is reduced, in the illumination device 100 using the light flux controlling member a-1 or a-2 of the present embodiment.

From this, it is understood that the illumination device using the light flux controlling member of the present embodiment can sufficiently suppress color unevenness on the light emitting surface of illumination device 100 while highly maintaining the light distribution characteristics.

(Effect)

As described above, light flux controlling member 132 of the present embodiment has a plurality of first ridges 142 arranged on first inner top surface 133a, and the height of first ridges 142 decreases as it approaches output surface 135. Accordingly, the emission direction of light emitted from light-emitting element 131, particularly light emitted at a small angle with respect to optical axis LA of light-emitting element 131 (light having a large contribution to color unevenness), is appropriately changed, and the emission direction of the other light (light having a small contribution to color unevenness) is not required to be changed more than necessary, so that it is possible to suppress color unevenness while maintaining desired light distribution characteristics.

[ embodiment 2]

(Structure of light flux controlling Member)

Next, light flux controlling member 132 according to embodiment 2 will be described with reference to fig. 11. Fig. 11A to 11D are diagrams showing the configuration of a light flux controlling member according to embodiment 2. Fig. 11A is a plan view of light flux controlling member 132, fig. 11B is a sectional view taken along line 11B-11B in fig. 11A, fig. 11C is a bottom view, and fig. 11D is a side view. Fig. 12A is a sectional view taken along line a-a of the exit surface of fig. 11D, and fig. 12B is a sectional view taken along line B-B of the exit surface of fig. 11D. Light flux controlling member 132 of the present embodiment differs from light flux controlling member 132 of embodiment 1 in that, instead of incident surface 133 (first top surface 133a) having a plurality of first ridges 142, two emission surfaces 135 have a plurality of second ridges 143. Therefore, the same components as light flux controlling member 132 according to embodiment 1 are denoted by the same reference numerals, and descriptions thereof are omitted.

In light flux controlling member 132 of the present embodiment, a plurality of second ridges 143 are arranged on each of two emission surfaces 135 (see fig. 11D).

The cross-sectional shape of the second protrusions 143 in a cross-section perpendicular to the ridge lines of the second protrusions 143 is not particularly limited, and may be a wave shape, a semicircular shape, a semi-elliptical shape, a triangular shape, or a rectangular shape (including a trapezoidal shape). In the present embodiment, the cross-sectional shape of the second ridge 143 in a cross section perpendicular to the ridge line of the second ridge 143 is triangular (see fig. 12A and 12B).

The second protrusion 143 has a ridge line substantially parallel to the optical axis LA of the light emitting element 131 when viewed along the direction (Y-axis direction) in which the two emission surfaces 135 face each other. Substantially parallel means that an angle formed by the optical axis LA of the light emitting element 131 and the ridge line of the second protrusion 143 is 15 ° or less, preferably 0 ° when viewed along the Y-axis direction. The reason why the angle formed by optical axis LA and the ridge line of second ridge 143 is as small as possible is because the molded article can be easily removed from the mold without making the mold for molding light flux controlling member 132 have a complicated structure. If the mold structure can be adopted that slides in a direction intersecting the molded article removal direction, the angle of inclination with respect to the optical axis LA may not be limited. When light flux controlling member 132 is mounted on substrate 120, the angle formed by optical axis LA and the ridge line of second ridge 143 may be largely inclined.

Similarly to the above, the "ridge line" in the second convex stripes 143 means a linear connection of the highest portions of the convex stripes, and means a line connecting the apexes of the second convex stripes 143 in a cross section perpendicular to the optical axis LA of the light-emitting elements 131.

In a cross section perpendicular to the ridge line of the second ribs 143, the center-to-center distances a (distances in the X-axis direction) of the plurality of second ribs 143 may be the same or different. From the viewpoint of achieving a desired light distribution and suppressing color unevenness, the center-to-center distances a of the plurality of second convex strips 143 are preferably the same. As described above, the "center-to-center distance a between the second ribs 143" refers to a distance between center lines of the second ribs 143 in a cross section perpendicular to the ridge lines of the second ribs 143 (see fig. 13).

In a cross section perpendicular to the ridge line of the second ridge 143, the heights b (lengths in the Y-axis direction) of the plurality of second ridges 143 may be the same or different. From the viewpoint of ease of mold processing, the heights b of the plurality of second ridges 143 are preferably the same. As described above, the "height b of the second ridge 143" is a length that is half of a distance between a straight line connecting apexes of two adjacent second ridges 143 and a straight line connecting a valley bottom of a recess formed between the two second ridges 143 and a valley bottom of two recesses formed on both sides of the recess in a cross section perpendicular to a ridge line of the second ridge 143 (see fig. 13).

Preferably, in a cross section perpendicular to the ridge line of the second ribs 143, a ratio of the distance a between the centers of the plurality of second ribs 143 to the height b is a: b is 1: 0-1: 0.5. if a: when b is within the above range, the traveling direction of the light emitted from emission surface 135 can be easily changed slightly, and thus, desired light distribution can be easily achieved and color unevenness can be suppressed. In view of improving the effect of color unevenness, the processing accuracy of the mold, and the transferability of light flux controlling member 132 during molding, it is preferable that the center-to-center distance a between the plurality of second ridges 143 is 0.1mm to 2 mm.

The height B of the second protrusions 143 in a cross section perpendicular to the ridge line of the second protrusions 143 decreases as the rear surface side approaches from the front surface side (see fig. 12A and 12B). That is, light emitted from the light emission center of light-emitting element 131 at a small angle with respect to optical axis LA of light-emitting element 131 (light contributing largely to color unevenness) is likely to enter first inner top surface 133a, be reflected by reflection surface 134, and then be emitted from a portion closer to the upper ends of two emission surfaces 135 (the front surface side of light flux controlling member 132). Therefore, the height b of second ridge 143 closer to the front surface side (reflection surface 134 side) of light flux controlling member 132 is increased, and the traveling direction of light emitted from emission surface 135 is easily changed.

On the other hand, light emitted from the light emission center of light-emitting element 131 at a large angle with respect to optical axis LA of light-emitting element 131 (light contributing little to color unevenness) is likely to enter second inner top surface 133c or third inner top surface 133d, fourth inner top surface 133e, or inner side surface 133b, for example, and then directly reach the lower ends of two emission surfaces 135 (the back surfaces of light flux controlling members 132), and is likely to be emitted from a portion closer to the lower end of emission surface 135 (the back surface of light flux controlling member 132). Therefore, the height b of second ridge 143 closer to the rear surface side (bottom surface 138 side) of light flux controlling member 132 is reduced so that the traveling direction of light emitted from emission surface 135 does not need to be changed more than necessary, and thus the light distribution characteristics are not impaired. This can suppress color unevenness on the light-emitting surface of the illumination device 100, and further, the light distribution characteristics of the light-emitting device 130 are less likely to be impaired (see fig. 12A and 12B).

The height b of the second protrusions 143 in a cross section perpendicular to the ridge line of the second protrusions 143 may linearly decrease from the front side toward the back side, or may curvilinearly decrease. Similarly to the above, the linearly lower means that the inclination of the ridge line of the second ridge 143 is constant regardless of the position in the ridge line direction of the second ridge 143; the curved lower portion means that the inclination of the ridge of the second ridge 143 changes depending on the position in the ridge direction of the second ridge 143. Specifically, the inclination of the ridge of the second ridge 143 is the inclination of the ridge in the cross section including the ridge of the second ridge 143. When the ridge line in the cross section including the ridge line of the second ridge 143 is a curve, the inclination of the ridge line at each position refers to the inclination of the tangent to the curve at that position. In the present embodiment, the height b of the second protrusion 143 linearly decreases from the front side toward the back side.

The region where the height b of the second ridges 143 decreases as it approaches the back surface side may be the entire region in the ridge line direction of the second ridges 143 or a partial region. In the present embodiment, the region where the height b of the second ridges 143 becomes lower as it approaches the back surface side is the entire region in the ridge line direction of the second ridges 143.

(action)

In light flux controlling member 132 of the present embodiment, a plurality of second convex stripes 143 (see fig. 11D) having ridges substantially parallel to optical axis LA (Z-axis direction) of light emitting element 131 are arranged on both emission surfaces 135. In addition, the height of the second protrusions 143 in a cross section perpendicular to the ridge line of the second protrusions 143 decreases as the rear surface side approaches from the front surface side (see fig. 12A and 12B). Thus, light emitted from the light emission center of light-emitting element 131 at a small angle with respect to optical axis LA of light-emitting element 131 (light contributing largely to color unevenness) is easily incident on first inner top surface 133a, and then reflected by rear reflection surface 134 to reach the vicinity of the upper end portion of emission surface 135 (the front surface side of light flux controlling member 132). Since the traveling direction of light reaching the vicinity of the upper end portion of emission surface 135 (the front surface side of light flux controlling member 132) is appropriately changed by second convex strip 143 (having a high height), the light can reach a specific region of light diffusion plate 150 without being concentrated.

On the other hand, light emitted from the light emission center of light-emitting element 131 at a large angle (light contributing little to color unevenness) with respect to optical axis LA of light-emitting element 131 easily enters inner surface 133b or the like and then reaches the vicinity of the lower end of emission surface 135 (the rear surface side of light flux controlling member 132). Light reaching the vicinity of the lower end portion of emission surface 135 (the rear surface side of light flux controlling member 132) does not need to be changed in the traveling direction of light by more than necessary by second convex strip 143 (having a small height), and therefore, the light distribution characteristics are not easily impaired.

This can suppress color unevenness on the light-emitting surface of illumination device 100, and further reduce the light distribution characteristics of light emitted from light-emitting element 131.

In embodiment 2, an example is shown in which the width (the size in the X-axis direction) of the second ridge 143 is constant in the ridge direction of the second ridge 143 in a cross section perpendicular to the ridge of the second ridge 143 (see fig. 11D, 12A, and 12B), but this is not limitative. That is, the width (size in the X-axis direction) of the second ridge 143 in a cross section perpendicular to the ridge line of the second ridge 143 may be different between the cross section along line a-a and the cross section along line B-B.

Fig. 13A to 13C are views showing modified examples of the cross-sectional shape of the emission surface 135 in a cross section perpendicular to the ridge line of the second ridge 143. As shown in fig. 13A to 13C, in a cross section perpendicular to the ridge line of the second ridge 143, the width C (the size in the X-axis direction) of the second ridge 143 may be smaller as approaching the back surface side. This can provide the same effect as in the case of a constant height. Note that, in a cross section perpendicular to the ridge line of the second ridge 143, the center-to-center distance a of the plurality of second ridges 143 is constant (see fig. 13A to 13C).

In embodiment 2, the example in which the cross-sectional shape of the second ridge 143 in the cross-section perpendicular to the ridge line of the second ridge 143 is a triangle as shown in fig. 12A and 12B is shown, but the present invention is not limited thereto.

Fig. 14A to 14F are views showing modified examples of the cross-sectional shape of the emission surface 135 in a cross section perpendicular to the ridge line of the second ridge 143. That is, the cross-sectional shape of the second ridges 143 in a cross section perpendicular to the ridge lines of the second ridges 143 may be a wave shape (see fig. 14A to 14B), or a semi-circle shape or a semi-ellipse shape (see fig. 14C to 14F).

(simulation 2)

Illumination distribution and chromaticity Y values on light diffusion plate 150 of illumination device 100 using light flux controlling member B-1 (fig. 11A to 11D, fig. 12A and 12B) or B-2 (fig. 13A to 13C) of the present embodiment were analyzed.

For comparison, the illuminance distribution and chromaticity Y value on the light diffusion plate were also analyzed for the illumination apparatus using the following light flux controlling member (comparative 1) and the illumination apparatus using the following light flux controlling member (comparative 2): the light flux controlling member (comparative example 1) has the same configuration as the light flux controlling member B-1 or B-2 except that the output surface 135 does not have the ridge, and the light flux controlling member (comparative example 2) has the same configuration as the light flux controlling member B-1 or B-2 except that the height of the second ridge in the Z-axis direction is constant.

The parameters of emission surface 135 of light flux controlling members B-1 and B-2 are set as follows. The other common parameters were set to be the same as in simulation 1.

< parameters of the exit surface 135 >

The shape of the emission surface 135 having the second protrusion 143 in a cross section perpendicular to the ridge line of the second protrusion 143 is triangular. The center-to-center distances a and heights b of the plurality of second ridges 143 in a cross section perpendicular to the ridge line of the second ridges 143 are set as follows.

Light flux controlling Member B-1

Distance a between centers: height b is 1: 0.13(A-A line section)

The center-to-center distance a is 750 μm and the height b is 100 μm

The height h (see fig. 11D) of the exit surface 135 in the Z-axis direction is 3.9mm

The height B of the second protrusions 143 is set to gradually decrease as approaching the bottom surface 138 in the Z-axis direction, and the height B in the cross section of the line B-B approaches 0 μm.

Light flux controlling Member B-2

Distance a between centers: height b is 1: 0.15(A-A line section)

The center-to-center distance a is 750 μm and the height b is 110 μm

The height h (see fig. 11D) of the exit surface 135 in the Z-axis direction is 3.9mm

The height B of the second protrusions 143 is set to gradually decrease as approaching the bottom surface 138 in the Z-axis direction, and the height B in the cross section of the line B-B approaches 0 μm. The width of the second projection 143 is also set so as to gradually decrease toward the bottom surface 138 in the Z-axis direction, and the width in the cross section of the line B-B is set so as to approach 0 μm.

Fig. 15A is a graph showing the analysis result of the illuminance distribution on the light diffusion plate of the illumination device of the present embodiment and the analysis result of the illuminance distribution on the light diffusion plate of the illumination device for comparison. The abscissa of fig. 15A represents the distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light-emitting element 131 on the light diffusion plate 150, and the ordinate represents the relative illuminance when the maximum illuminance at each distance on the light diffusion plate 150 is 1.

Fig. 15B is a graph showing the analysis result of the chromaticity Y value on the light diffusion plate of the illumination device of the present embodiment and the analysis result of the chromaticity Y value on the light diffusion plate of the illumination device for comparison. The horizontal axis of fig. 15B represents the distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light-emitting element 131 on the light diffusion plate 150, and the vertical axis represents the chromaticity Y value on the light diffusion plate 150.

As shown in fig. 15A, it is understood that the spread of light in the Y-axis direction is not significantly impaired in the illuminance distribution of the illumination apparatus using light flux controlling member B-1 or B-2 of the present embodiment compared with the illuminance distribution of the illumination apparatus using the comparative light flux controlling member (comparative 1), and the light distribution characteristics can be almost maintained. Further, it is found that the spread of light in the Y-axis direction is wider than the illuminance distribution of the illumination device using the comparative light flux controlling member (comparative 2), and the light distribution characteristics are less likely to be impaired (compared to comparative 2).

As shown in fig. 15B, in the illumination device (comparative 1) using the comparative light flux controlling member, while the chromaticity difference between the bottom of the valley at a distance d2 near 40mm from the optical axis LA of the light-emitting element 131 and the top adjacent thereto (see the arrow in fig. 15B) is large, and the slight blue color unevenness occurs, in the illumination device 100 using the light flux controlling member B-1 or B-2 of the present embodiment, the chromaticity difference between the bottom of the valley at a distance d2 near 40mm from the optical axis LA of the light-emitting element 131 and the top adjacent thereto is small, and the color unevenness is reduced. Further, it is also understood that illumination device 100 using light flux controlling member B-1 or B-2 of the present embodiment can obtain the effect of reducing color unevenness equivalent to that of comparative example 2.

From this, it is understood that the illumination device using the light flux controlling member of the present embodiment can sufficiently suppress color unevenness on the light emitting surface of illumination device 100 while maintaining favorable light distribution characteristics.

(Effect)

As described above, light flux controlling member 132 according to the present embodiment has a plurality of second protrusions 143 disposed on both emission surfaces 135, and the height of second protrusions 143 decreases as the rear surface side approaches from the front surface side. Accordingly, the emission direction of light emitted from light-emitting element 131, particularly light emitted at a small angle with respect to optical axis LA of light-emitting element 131 (light having a large contribution to color unevenness), is appropriately changed, and the emission direction of the other light (light having a small contribution to color unevenness) is not required to be changed more than necessary, so that it is possible to suppress color unevenness while maintaining desired light distribution characteristics.

[ embodiment 3]

(Structure of light flux controlling Member)

Next, light flux controlling member 132 according to embodiment 3 will be described with reference to fig. 16. Fig. 16A to 16D are diagrams showing the structure of a light flux controlling member according to embodiment 3. Fig. 16A is a plan view of light flux controlling member 132, fig. 16B is a cross-sectional view taken along line 16B-16B of fig. 16A, fig. 16C is a bottom view, and fig. 16D is a side view. Fig. 17A is a sectional view taken along line a-a of first interior top surface 133a of fig. 16C, and fig. 17B is a sectional view taken along line B-B of first interior top surface 133a of fig. 16C. Light flux controlling member 132 of the present embodiment is different from light flux controlling member 132 of embodiment 1 in that second ridges 143 and third ridges 144 are also provided on two emission surfaces 135 and two reflection surfaces 134, respectively. Therefore, the same components as light flux controlling member 132 according to embodiment 1 are denoted by the same reference numerals, and descriptions thereof are omitted.

In light flux controlling member 132 of the present embodiment, a plurality of second ridges 143 are further arranged on both emission surfaces 135 (see fig. 16D). The height b in the cross section perpendicular to the ridge line of the second protrusion 143 may be constant in the Z-axis direction, or may become lower as it approaches the bottom surface 138. In the present embodiment, the height b in a cross section perpendicular to the ridge line of the second ridge 143 is constant in the Z-axis direction.

The cross-sectional shape of emission surface 135 of light flux controlling member 132 in the cross section perpendicular to the ridge line of second ridge 143 is set so as to satisfy expression (1).

hy ═ b × cos (2 pi dx/a) … formula (1)

(a: the distance (mm) between the centers of the plurality of second protrusions 143;

b: the height (mm) of the second protruding strips 143;

dx: a distance from the center in the exit surface 135 (distance in the X-axis direction; mm);

hy: height (height in the Y-axis direction; mm) from the reference plane of the exit surface 135. )

Preferably, in a cross section perpendicular to the ridge line of the second ribs 143, a ratio of the distance a between the centers of the plurality of second ribs 143 to the height b is a: b is 2: 1-13: 1. if a: when b is within the above range, the traveling direction can be slightly changed without scattering the light emitted from the two emission surfaces 135, and therefore, desired light distribution can be easily achieved and color unevenness can be suppressed. In particular, from the viewpoint of further improving the luminance distribution without suppressing color unevenness, the ratio of the center-to-center distance a to the height b of the second ridges 143 is more preferably a: b is 5: 1-11: 1, more preferably a: b is 5: 1-10: 1.

in a cross section perpendicular to the ridge line of the second ridges 143, the center-to-center distance a between the plurality of second ridges 143 is not particularly limited, but is preferably 0.125mm or more and 4.000mm or less, for example, from the viewpoint of easily obtaining the effect of suppressing color unevenness. In particular, the ratio of the distance a between the centers of the plurality of second protrusions 143 to the height b is a: b is 5: 1-10: in case 1, the center-to-center distance a between the second protrusions 143 is more preferably more than 0.125mm and 2.000mm or less.

In light flux controlling member 132 of the present embodiment, a plurality of third ridges 144 are further arranged on at least a part of two reflecting surfaces 134, preferably in a region where light incident from first inner top surface 133a reaches (see fig. 16A and 16B).

The region of the two reflection surfaces 134 that is reached by the light incident on the first inner top surface 133a is, for example, a region of the two reflection surfaces 134 in the vicinity of the optical axis LA of the light emitting element 131 (see fig. 16A). The third ribs 144 are formed such that the ridge thereof is substantially perpendicular to the direction in which the two emission surfaces 135 face each other (or the ridge of the first ribs 142) when viewed along the optical axis LA of the light emitting element 131 (when viewed along the Z-axis direction). Specifically, the substantially perpendicular direction means that the angle formed by the direction in which the two light emission surfaces 135 face each other (or the ridge line of the first ridge 142) and the ridge line of the third ridge 144 is 90 ± 5 ° or less, preferably 90 °.

The plurality of third ribs 144 are formed such that the ridge line thereof is substantially perpendicular to the ridge line of the first rib 142 when viewed along the optical axis LA of the light-emitting element 131 (when viewed along the Z-axis direction).

As described above, the "ridge line" in the third convex stripes 144 refers to a linear connection connecting the highest portions of the convex stripes, and refers to a line connecting the apexes of the third convex stripes 144 in a cross section parallel to the Y-axis direction and including the optical axis LA of the light-emitting elements 131. The plurality of third ribs 144 may be arranged such that the ridge lines thereof are substantially parallel to the X-axis direction when viewed along the Z-axis direction (see fig. 16A), or may be arranged so as to form a part of an annular shape surrounding the optical axis LA (not shown).

In a cross section perpendicular to the ridge line of the third ridge 144 (a cross section parallel to the Y-axis direction including the optical axis LA of the light-emitting element 131), the cross-sectional shape of the third ridge 144 is not particularly limited, and may be a wave shape, a triangle shape, or a rectangle shape (including a trapezoid shape).

In a cross section perpendicular to the ridge line of the third ridges 144, the center-to-center distances a (distances in the Y-axis direction) of the plurality of third ridges 144 may be the same or different. For example, in a cross section perpendicular to the ridge line of the third ribs 144, the distance a between the centers of the plurality of third ribs 144 may gradually decrease as the distance increases in the Y-axis direction from the optical axis LA of the light-emitting element 131. As described above, the center-to-center distance a of the third ridges 144 is a distance between the center lines of two adjacent third ridges 144 in a cross section including the optical axis LA of the light-emitting element 131 and parallel to the Y-axis direction.

In a cross section perpendicular to the ridge line of the third ridges 144, the heights b (lengths in the Z-axis direction) of the plurality of third ridges 144 may be the same or different. For example, in a cross section perpendicular to the ridge line of the third ridge 144 (a cross section parallel to the Y-axis direction including the optical axis LA of the light-emitting element 131), the height b of the third ridge 144 may gradually decrease as the distance from the optical axis LA of the light-emitting element 131 in the Y-axis direction increases. The "height b of the third ridges 144" is a length half of a distance between a straight line connecting apexes of two adjacent third ridges 144 and a straight line connecting a valley bottom of a recess formed between the two third ridges 144 and a valley bottom of two recesses formed on both sides of the recess in a cross section perpendicular to the ridge line of the third ridges 144.

(action)

In light flux controlling member 132 of the present embodiment, first ridges 142 (see fig. 16C) having ridges substantially parallel to the Y-axis direction are arranged on first inner top surface 133a, third ridges 144 (see fig. 16A) having ridges substantially parallel to the X-axis direction are arranged on both reflection surfaces 134, and second ridges 143 (see fig. 16D) having ridges substantially parallel to the Z-axis direction are arranged on both emission surfaces 135. Accordingly, the traveling direction of light emitted from the light-emitting center of the light-emitting element 131 at a small angle with respect to the optical axis LA of the light-emitting element 131 is appropriately changed by the first ridges 142 of the incident surface 133, the third ridges 144 of the reflection surface 134, and the second ridges 143 of the emission surface 135, respectively, and thus the light can reach a specific region of the light diffusion plate 150 without being concentrated.

(simulation 3)

Illumination device 100 using light flux controlling member C-1 (fig. 16A to 16D, 17A, and 17B) or C-2 (light flux controlling member after changing the shape of first inner top surface 133a of C-1 to fig. 8A to 8C) (fig. 16A, 16B, 16D, and 8A to 8C) of the present embodiment was analyzed for the illuminance distribution and chromaticity Y value on light diffusion plate 150.

For comparison, the illuminance distribution and chromaticity Y value on the light diffusion plate were also analyzed for an illumination apparatus using a light flux controlling member (comparison) configured in the same manner as the light flux controlling member C-1 or C-2 except that the first inner top surface 133a had no convex line.

In light flux controlling member C-1 (fig. 16A to 16D, 17A and 17B) and C-2 (fig. 16A, 16B, 16D, and 8A to 8C), the parameters of two reflecting surfaces 134 and the parameters of two emitting surfaces 135 are set as follows, respectively. The parameters and common parameters of the first ceiling surface 133a are the same as those of simulation 1.

< parameters of reflecting surface 134 >

The shape of the reflection surface 134 having the third ridges 144 in a cross section perpendicular to the ridges of the third ridges 144 is set as follows.

FIG. 18A is a graph showing the cross-sectional shape of reflection surface 134 of light flux controlling member C-1 or C-2 in a cross section perpendicular to the ridge line of third ridge 144. FIG. 18B is a graph showing the result (Δ h 1; mm) of the analysis of the cross-sectional shape of reflecting surface 134 of light flux controlling member configured in the same manner as light flux controlling member C-1 or C-2 except that third ridge 144 is not present, subtracted from the result of the analysis of the cross-sectional shape of reflecting surface 134 of light flux controlling member C-1 or C-2 of FIGS. 17A to 17D having third ridge 144 in a cross section perpendicular to the ridge line of third ridge 144.

The horizontal axis in fig. 18A and 18B represents a distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light-emitting element 131. The vertical axis in fig. 18A represents a height h1 (height in the Z-axis direction; mm) from the bottom surface 138 of a point where the reflection surface 134 intersects the optical axis LA of the light emitting element 131. The vertical axis in FIG. 18B shows a difference Δ h1 (height in the Z-axis direction; mm) obtained by subtracting the sectional shape of reflection surface 134 of the light flux controlling member without third ridge 144 from the sectional shape of reflection surface 134 of light flux controlling member C-1 or C-2 having third ridge 144.

a: distance (mm) between centers of third ribs 144

b: height (length in Z-axis direction; mm) of the third projecting strip 144

Distance a between centers of the third ribs 144: height b is 20: 1

The third ribs 144 have a center-to-center distance a of 500 μm and a height b of 25 μm

< parameters of the exit surface 135 >

The shape of the emission surface 135 having the second ridges 143 in a cross section perpendicular to the ridges of the second ridges 143 is set so as to satisfy the above expression (1). The center-to-center distances a and heights b of the plurality of second ridges 143 in a cross section perpendicular to the ridge line of the second ridges 143 are set as follows. Note that the height b of the second protrusion 143 is constant in the ridge line direction.

Distance a between centers: height b is 7.5: 1(A-A line, B-B line section common)

The center-to-center distance a is 750 μm and the height b is 100 μm

Fig. 19A is a graph showing the analysis result of the illuminance distribution on the light diffusion plate of the illumination device of the present embodiment and the analysis result of the illuminance distribution on the light diffusion plate of the illumination device for comparison. The horizontal axis of fig. 19A represents the distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light-emitting element 131 on the light diffusion plate 150, and the vertical axis represents the relative illuminance when the maximum illuminance at each distance on the light diffusion plate 150 is 1.

Fig. 19B is a graph showing the analysis result of the chromaticity Y value on the light diffusion plate of the illumination device of the present embodiment and the analysis result of the chromaticity Y value on the light diffusion plate of the illumination device for comparison. The horizontal axis of fig. 19B represents the distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light-emitting element 131 on the light diffusion plate 150, and the vertical axis represents the chromaticity Y value on the light diffusion plate 150.

As shown in fig. 19A, it can also be seen that in the illuminance distribution of the illumination device using light flux controlling member C-1 or C-2 according to the present embodiment, the spread of light in the Y-axis direction is equivalent to that of the illumination device using the comparative light flux controlling member, and the light distribution characteristics are highly maintained.

As shown in fig. 19B, in the illumination device using the comparative light flux controlling member, while the chromaticity difference between the valley bottom portion of the distance d2 from the optical axis LA of the light-emitting element 131 in the vicinity of 40mm and the top portion adjacent thereto (see the arrow in fig. 19B) was large, and the slight blue color unevenness occurred, the chromaticity difference between the valley bottom portion of the distance d2 from the optical axis LA of the light-emitting element 131 in the vicinity of 40mm and the top portion adjacent thereto was small in the illumination device 100 using the light flux controlling member C-1 or C-2, and the color unevenness was particularly reduced.

From this, it is understood that the illumination device using the light flux controlling member of the present embodiment can sufficiently suppress color unevenness on the light emitting surface of illumination device 100 while highly maintaining the light distribution characteristics.

(Effect)

As described above, light flux controlling member 132 of the present embodiment has a plurality of first ridges 142 arranged on first inner top surface 133a, a plurality of second ridges 143 arranged on two emission surfaces 135, and a plurality of third ridges 144 arranged on two reflection surfaces 134. Accordingly, the emission direction of light emitted from light emitting element 131, particularly light emitted at a small angle with respect to optical axis LA of light emitting element 131 (light contributing a large amount of color unevenness), is easily changed more than necessary (compared with the case where only one of first inner top surface 133a, emission surface 135, and reflection surface 134 has a convex line), and the emission direction of the other light (light contributing a small amount of color unevenness) is not changed more than necessary, so that it is possible to suppress color unevenness while maintaining desired light distribution characteristics.

[ modified examples ]

In embodiments 1 and 3, an example is shown in which, in light flux controlling member 132, a plurality of first ridges 142 are provided only on first inner top surface 133a, but the present invention is not limited to this, and at least one of second inner top surface 133c, third inner top surface 133d, and fourth inner top surface 133e other than first inner top surface 133a may be further provided. Similarly, in embodiments 2 and 3, an example is shown in which the plurality of second ribs 143 are provided on the entire surface of the emission surface 135, but the present invention is not limited thereto, and may be provided only on a part of the emission surface 135.

In embodiments 1 to 3, an example is shown in which a plurality of first ridges 142 (or second ridges 143) are provided on the planar first inner top surface 133a (or emission surface 135) in the light flux controlling member 132, but the present invention is not limited thereto, and may be provided on a curved (for example, concave) first inner top surface 133a (or emission surface 135).

In embodiments 1 to 3, an example is shown in which the shape of the inner surface of concave portion 139 in light flux controlling member 132 is a surface having an edge, but the present invention is not limited thereto, and a curved surface having no edge such as a hemispherical shape or a semi-elliptical shape may be used. In this case, the first inner top surface 133a, the second inner top surface 133c, the third inner top surface 133d, the fourth inner top surface 133e, and the inner side surface 133b may be continuously formed.

In embodiments 1 to 3, an example is shown in which, in addition to first ceiling surface 133a (ceiling surface) and two inner side surfaces 133b, the inner surface shape of recess 139 has two second ceiling surfaces 133c, two third ceiling surfaces 133d, and two fourth ceiling surfaces 133e in light flux controlling member 132, but the present invention is not limited thereto, and one or more of two second ceiling surfaces 133c, two third ceiling surfaces 133d, and two fourth ceiling surfaces 133e may be omitted.

In embodiments 1 to 3, an example is shown in which, in a cross section of light flux controlling member 132 including optical axis LA of light emitting element 131 and parallel to the Y-axis direction, two emission surfaces 135 are substantially parallel to (not inclined to) optical axis LA of light emitting element 131, but the present invention is not limited thereto, and may be slightly inclined with respect to optical axis LA of light emitting element 131. For example, in a cross section including the optical axis LA of the light-emitting element 131 and parallel to the Y-axis direction, if the mold structure can be set such that the operability when the molded article is taken out from the mold is not impaired as the molded article is separated from the light-emitting element 131 along the Z-axis, the emission surface 135 may be inclined so as to be separated from the optical axis LA of the light-emitting element 131. This reduces the amount of light refracted and emitted upward (in the direction toward the light diffusion plate 150) from the emission surface 135, thereby further facilitating the uniformity of the illuminance distribution and the color distribution. An inclination angle of emission surface 135 with respect to optical axis LA of light-emitting element 131 in a cross section including optical axis LA of light-emitting element 131 and parallel to the Y-axis direction may be set to, for example, 10 ° or less.

In embodiments 1 to 3, an example in which the plurality of light emitting devices 130 are arranged in a single row in the illumination device 100 is shown, but the present invention is not limited thereto, and the light emitting devices may be arranged in a plurality of rows of two or more rows.

In embodiments 1 to 3, an example is shown in which a plurality of substrates 120 are disposed for each light-emitting device 130 in the illumination device 100, and the substrates 120 are electrically connected to each other by the cable 140, but the present invention is not limited thereto, and a plurality of light-emitting devices 130 may be disposed on one substrate 120. In this case, the cable 140 and the caulking part 141 are not required.

In embodiments 1 to 3, the case 110 is a box-shaped body having a bottom plate, four side plates, and a top plate (having an opening at least in a part) in the illumination device 100, but the present invention is not limited thereto, and the side plates and the top plate may be omitted as long as at least the bottom plate is provided.

Fig. 20 is a partially enlarged perspective view showing a configuration of a lighting device according to a modification. As shown in fig. 20, the top plate and the side plates of the housing 110 may be omitted, and only the bottom plate of the housing 110 may be covered with the light diffusion plate 150.

In embodiments 1 to 3, the illumination device 100 is an example of a slot-type character signboard, but the present invention is not limited thereto, and may be a line illumination or the like.

The present application claims priority based on japanese patent application laid-open at 12.10.2018, kokai 2018-. The contents described in the specification and drawings of this application are all incorporated in the specification of the present application.

Industrial applicability

The illumination device having the light flux controlling member of the present invention can be applied to, for example, signs (especially, channel letter signs), line illumination, general illumination, and the like.

Description of the reference numerals

100 lighting device

110 casing

120 substrate

130 light emitting device

131 luminous element

132 light beam control component

133 incident plane

133a inner top surface (first inner top surface)

133b inner side surface

133c second inner top surface

133d third inner top surface

133e fourth inner top surface

134 reflective surface

135 exit surface

136 flange portion

137 foot parts

138 bottom surface

139 recess

140 electric cable

141 caulking member

142 first convex strip

143 second protrusion strip

144 third rib

150 light diffusion plate

CA center shaft

LA optical axis