JP7093712B2 - Luminous flux control member, light emitting device and lighting device - Google Patents

Description

The present invention relates to a luminous flux control member, a light emitting device and a lighting device.

As a light source for a lighting device, a signboard, or the like, a light emitting device having a light emitting element such as an LED is used. Among them, as a light source such as a channel character type signboard having a special shape, the light emitted from the light emitting element is reflected in two directions opposite to each other in the horizontal direction to make the light distribution characteristic anisotropic. A light source (indicating an elliptical light distribution) is used.

As a light emitting device having an anisotropic light distribution characteristic, for example, in Patent Document 1, as shown in FIG. 1, a light emitting element 12 and a reflection cup 14a that reflects light emitted from the light emitting element 12 upward are shown. A light emitting device having a base (lead for mounting a chip) 14 and a light flux control member 13 (translucent resin in Patent Document 1) for sealing a light emitting element 12 and a reflection cup 14a is disclosed. The luminous flux control member 13 has two reflecting surfaces 17 that reflect the light emitted from the light emitting element 12 and the light reflected by the reflecting cup 14a, and two emitting surfaces that emit the light reflected by the reflecting surface 17 to the outside. 19 (side surface in Patent Document 1).

In such a light emitting device, the light emitted from the upper surface of the light emitting element 12 directly reaches the reflecting surface 17 of the luminous flux control member 13, and the light emitted from the side surface of the light emitting element 12 is reflected by the reflection cup 14a. After that, it reaches the two reflecting surfaces 17 of the luminous flux control member 13. Then, these lights that have reached the two reflecting surfaces 17 of the luminous flux control member 13 travel in the opposite directions in the horizontal direction, and are emitted to the outside from the two emitting surfaces 19 of the luminous flux control member 13.

As the light emitting element used in such a light emitting device, a light emitting element such as an LED is used. Most of the inexpensive and mass-produced LEDs have, for example, a light emitting element (SMD type) having a light emitting part that emits blue light and a phosphor that covers the periphery thereof and converts the blue light emitted from the light emitting part into white light. Light emitting element).

Japanese Unexamined Patent Publication No. 9-18508

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 in a long optical path in the phosphor and is emitted, so that it is easily converted into white light. On the other hand, blue light emitted at a small angle with respect to the optical axis of the light emitting element propagates in a short optical path in the phosphor and is emitted, so that it is difficult to be converted into white light and is emitted as bluish light. Cheap. Not limited to such an SMD type light emitting element, a light emitting element that emits light having a different color depending on the emission direction is applied to a light emitting device having an anisotropic light distribution characteristic as shown in Patent Document 1. Then, there is a problem that color unevenness is likely to occur in the region where the light emitted at a small angle with respect to the optical axis of the light emitting element reaches and the region where the light emitted at a large angle with respect to the optical axis reaches. rice field. Specifically, there is a problem that light emitted at a small angle with respect to the optical axis of the light emitting element tends to concentrate and reach a specific region of the light diffusing plate, and the blue color in that region tends to be strong. ..

On the other hand, when trying to suppress color unevenness, the light distribution characteristics tend to be impaired. Therefore, it is desired to be able to suppress color unevenness without impairing the light distribution characteristics (while maintaining a high degree of light distribution characteristics).

Therefore, an object of the present invention is to provide a luminous flux control 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 having this luminous flux control member.

The light beam control member according to the present invention is a light beam control member for controlling light distribution of light emitted from a light emitting element, is an inner surface of a recess arranged on the back side, and is light emitted from the light emitting element. 2 is arranged on the incident surface and a part of the light incident on the incident surface is reflected in two directions that are substantially perpendicular to the optical axis of the light emitting element and are opposite to each other. The incident surface has two reflecting surfaces and two emitting surfaces that are arranged so as to face each other with the two reflecting surfaces interposed therebetween and emit light reflected by the two reflecting surfaces to the outside. The inner top surface of the recess has two inner surfaces that sandwich the inner top surface of the recess and are arranged in a direction in which the two emission surfaces face each other, and the inner top surface has the light emitting surface. When viewed along the optical axis of the element, a plurality of first ridges having ridges substantially parallel to the directions in which the two emission surfaces face each other are arranged, and are perpendicular to the ridges of the first ridge. The height of the first ridge in the cross section becomes lower as it approaches the two exit surfaces.

The light beam control member according to the present invention is a light beam control member for controlling light distribution of light emitted from a light emitting element, is an inner surface of a recess arranged on the back side, and is light emitted from the light emitting element. 2 is arranged on the incident surface and a part of the light incident on the incident surface is reflected in two directions that are substantially perpendicular to the optical axis of the light emitting element and are opposite to each other. It has two reflecting surfaces and two emitting surfaces that are arranged so as to face each other with the two reflecting surfaces interposed therebetween and emit light reflected by the two reflecting surfaces to the outside. A plurality of second ridges having a ridge line substantially parallel to the optical axis of the light emitting element are arranged on each of the surfaces when viewed along the directions in which the two emission surfaces face each other. The height of the second ridge in the cross section perpendicular to the ridge of the two ridges decreases as it approaches the back side.

The light emitting device according to the present invention has a light emitting element and a light flux control member according to the present invention in which the incident surface is arranged so as to face the light emitting element.

The lighting device according to the present invention has a plurality of light emitting devices according to the present invention and a light diffusing plate that diffuses and transmits light emitted from the light emitting device.

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

FIG. 1 is a diagram showing a configuration of a conventional light emitting device. 2A and 2B are diagrams showing the configuration of the lighting device according to the first embodiment. FIG. 3 is a plan view of the lighting device with the light diffusing plate removed. 4A to 4C are views showing the configuration around the light emitting device shown in FIG. 5A to 5D are views showing the configuration of the light flux control member according to the first embodiment. 6A is a sectional view taken along line AA of the first inner top surface of FIG. 5C, and FIG. 6B is a sectional view taken along line BB of the first inner top surface of FIG. 5C. FIG. 7 is a graph showing the cross-sectional shape of the first inner top surface in the cross section perpendicular to the ridgeline of the first ridge. 8A to 8C are views showing a modified example of the cross-sectional shape of the first inner top surface in the cross section perpendicular to the ridgeline of the first ridge. 9A to 9F are views showing a modified example of the cross-sectional shape of the first inner top surface in the cross section perpendicular to the ridgeline of the first ridge. FIG. 10A shows the analysis result of the illuminance distribution on the light diffusing plate of the illuminating device using the luminous flux control member according to the first embodiment and the illuminance distribution on the light diffusing plate of the illuminating device using the luminous flux control member for comparison. 10B is a graph showing the analysis results of the above, and FIG. 10B shows the analysis results of the chromaticity Y value on the light diffusing plate of the lighting device using the light flux control member according to the first embodiment and the light flux control member for comparison. It is a graph which shows the analysis result of the chromaticity Y value on the light diffusing plate of the illuminating device used. 11A to 11D are views showing the configuration of the light flux control member according to the second embodiment. 12A is a sectional view taken along line AA of the exit surface of FIG. 11D, and FIG. 12B is a sectional view taken along line BB of the exit surface of FIG. 11D. FIGS. 13A to 13C are views showing an example of deformation of the cross-sectional shape of the exit surface in the cross section perpendicular to the ridgeline of the second ridge. 14A to 14F are views showing an example of deformation of the cross-sectional shape of the exit surface in the cross section perpendicular to the ridgeline of the second ridge. FIG. 15A shows the analysis result of the illuminance distribution on the light diffusing plate of the illuminating device using the light flux control member according to the second embodiment and the illuminance distribution on the light diffusing plate of the illuminating device using the luminous flux control member for comparison. 15B is a graph showing the analysis result of the above, and FIG. 15B uses the analysis result of the chromaticity Y value on the light diffusing plate of the lighting device using the light flux control member according to the second embodiment and the light flux control member for comparison. It is a graph which shows the analysis result of the chromaticity Y value on the light diffusing plate of the lighting apparatus. 16A to 16D are views showing the configuration of the luminous flux control member according to the third embodiment. 17A is a sectional view taken along line AA of the first inner top surface of FIG. 16C, and FIG. 17B is a sectional view taken along line BB of the first inner top surface of FIG. 16C. FIG. 18A is a graph showing a cross-sectional shape of the reflection surface of the light beam control member in a cross section perpendicular to the ridgeline of the third convex line, and FIG. 18B is a graph showing the third convexity in a cross section perpendicular to the ridgeline of the third convex line. It is a graph which shows the result (Δh1) which subtracted the design value of the cross-sectional shape of the reflection surface of the light beam control member which does not have a 3rd convex from the design value of the cross-sectional shape of the reflection surface of the light beam control member which has a stripe. FIG. 19A shows the analysis result of the illuminance distribution on the light diffusing plate of the illuminating device using the light flux control member according to the third embodiment and the illuminance distribution on the light diffusing plate of the illuminating device using the luminous flux control member for comparison. 19B is a graph showing the analysis result of the above, and FIG. 19B shows the analysis result of the chromaticity Y value on the light diffusing plate of the lighting device using the light flux control member according to the third embodiment and the light flux control member for comparison. It is a graph which shows the analysis result of the chromaticity Y value on the light diffusing plate of the lighting apparatus using. FIG. 20 is a partially enlarged perspective view showing the configuration of the lighting device according to the modified example.

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

[Embodiment 1]
(Construction of lighting equipment)
2A and 2B, and FIG. 3 are diagrams showing the configuration of the lighting device 100 according to the first embodiment. 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 lighting device 100 according to the present embodiment in a state where the light diffusing plate 150 is removed. 4A to 4C are views showing the configuration around the light emitting device 130 shown in 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 the line 4C-4C of FIG. 4B. The lighting device 100 shown in the figure is used, for example, as a channel character signboard.

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

The housing 110 is a box-shaped body in which at least a part of one surface is opened for accommodating a plurality of substrates 120 and a plurality of light emitting devices 130 inside the housing 110. In the present embodiment, the housing 110 is composed of a bottom plate, a top plate facing the bottom plate, and four side plates connecting the bottom plate and the top plate. The top plate is formed with an opening that serves as a light emitting region. This opening is closed by the light diffusing plate 150. The bottom plate and the top plate are arranged in parallel. The height (space thickness) from the surface of the bottom plate to the light diffusing plate 150 is not particularly limited, but is about 20 to 100 mm. The housing 110 is made of, for example, a resin such as polymethyl methacrylate (PMMA) or polycarbonate (PC), or a metal such as stainless steel or aluminum.

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

The plurality of substrates 120 are flat plates for arranging the plurality of light emitting devices 130 on the bottom plate of the housing 110 at predetermined intervals (see FIG. 4C). In the present embodiment, the substrate 120 is arranged on the bottom plate of the housing 110 via a caulking material 141 described later (see FIG. 4C). The wiring of the board 120 is electrically connected by the cable 140.

The plurality of light emitting devices 130 are arranged on the bottom plate of the housing 110 via the plurality of substrates 120, respectively. The number of light emitting devices 130 arranged 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 the 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 control member 132. In each of the plurality of light emitting devices 130, the optical axis of the light emitted from the light emitting element 131 (the optical axis LA of the light emitting element 131 described later) is arranged so as to be along the normal line with respect to the surface of the substrate 120.

The light emitting element 131 is a light source of the lighting device 100 (and the light emitting device 130). The light emitting element 131 is arranged on the substrate 120 (see FIG. 4C) and is electrically connected to the 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 emitted light of the light emitting element 131 included in the light emitting device 130 is not particularly limited. In the present embodiment, for example, an SMD type light emitting element having a light emitting portion that emits blue light and a phosphor that covers the periphery thereof and converts the blue light emitted from the light emitting portion into white light can be used.

The luminous flux control member 132 controls the light distribution of the light emitted from the light emitting element 131, and the traveling direction of the light is substantially perpendicular to the surface direction of the substrate 120, particularly the optical axis LA of the light emitting element 131. Change in two directions that are opposite to each other. The luminous flux control member 132 is arranged so that its incident surface 133 faces the light emitting element 131, specifically, its central axis CA coincides with the optical axis LA of the light emitting element 131 (see FIG. 4C). ). The "optical axis LA of the light emitting element 131" means a light ray at the center of a three-dimensional emitted light flux from the light emitting element 131. The "central axis CA of the luminous flux control member 132" means, for example, a axis of symmetry that is twice symmetric.

Hereinafter, in each light emitting device 130, two light emitting elements 131 pass through the light emitting center and are orthogonal to each other in a direction parallel to the optical axis LA of the light emitting element 131 in the Z-axis direction and a plane perpendicular to the Z-axis direction. The directions are called the X-axis direction and the Y-axis direction. Specifically, in the light beam control member 132 described later, the direction in which the two emission surfaces 135 described later face each other is the Y-axis direction, and the direction orthogonal to the Y-axis direction in the plane perpendicular to the Z-axis direction is set. It is called the X-axis direction.

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

The lighting device 100 according to the present embodiment has a main feature in the configuration of the luminous flux control member 132. Therefore, the luminous flux control member 132 will be described in detail separately.

The cable 140 electrically connects a plurality of adjacent boards 120 to each other. The connection between the substrate 120 and the cable 140 is reinforced with a caulking material 141 (see FIG. 4C). Examples of the material of the caulking material 141 include urethane resin, silicone resin, and epoxy resin.

In this way, by electrically connecting the plurality of light emitting devices 130 via the cable 140 and modularizing them, the plurality of light emitting devices 130 can be freely arranged according to the shape of the housing 110.

The light diffusing plate 150 is arranged so as to close the opening of the housing 110 (see FIGS. 2A and 2B). The light diffusing plate 150 is a plate-shaped member having light transmittance and light diffusivity, and transmits light emitted from the emission surface 135 (see FIG. 5) of the light flux control member 132 while diffusing it. The light diffusing plate 150 can be, for example, a light emitting surface of the lighting device 100.

The material of the light diffusing plate 150 is not particularly limited as long as it can transmit the emitted light from the emitting surface 135 of the light beam control member 132 while diffusing it, and is, for example, polymethyl methacrylate (PMMA), polycarbonate (PC), and the like. It is a light-transmitting resin such as polystyrene (PS) and styrene-methylmethacrylate copolymer resin (MS). In order to impart light diffusivity, fine irregularities are formed on the surface of the light diffusing plate 150, or light diffusing elements such as beads are dispersed inside the light diffusing plate 150.

In the lighting device 100 according to the present embodiment, the light emitted from each light emitting element 131 is omitted so as to illuminate a wide range of the light diffusing plate 150 by the luminous flux control member 132, particularly with respect to the optical axis LA of the light emitting element 131. It is converted into light emitted in two directions (Y-axis direction in FIGS. 4A to 4C) that are vertically and opposite to each other. The light emitted from each luminous flux control member 132 is further diffused by the light diffusing plate 150 and emitted to the outside. Thereby, color unevenness and illuminance unevenness of the lighting device 100 can be suppressed.

(Structure of luminous flux control member)
5A to 5D are views showing the configuration of the luminous flux control member 132. 5A is a plan view of the luminous flux control member 132, FIG. 5B is a cross-sectional view taken along the line 5B-5B of FIG. 5A, FIG. 5C is a bottom view, and FIG. 5D is a side view. 6A is a sectional view taken along line AA of the first inner top surface 133a of FIG. 5C, and FIG. 6B is a sectional view taken along line BB of the first inner top surface 133a of FIG. 5C.

The luminous flux control member 132 controls the light distribution of the light emitted from the light emitting element 131. As shown in FIGS. 5A-D, the luminous flux control member 132 has an incident surface 133, two reflecting surfaces 134, two emitting surfaces 135, a collar 136 and two legs 137. Hereinafter, the side on which the incident surface of the luminous flux control member 132 is formed (the side of the light emitting element 131) is referred to as the back side, and the side on which the reflection surface 134 is formed is referred to as the front side.

The incident surface 133 causes a part of the light emitted from the light emitting element 131 to be incident. The incident surface 133 is the inner surface of the recess 139 formed on the back side of the luminous flux control member 132, that is, in the central portion of the bottom surface 138. The inner surface shape of the concave portion 139 is not particularly limited, and may be a surface including an edge, or may be a curved surface having no edge, such as a hemispherical shape or a semi-elliptical shape. In the present embodiment, the inner surface shape of the recess 139 is a surface including an edge.

Specifically, the inner surface (incident surface 133) of the recess 139 has at least a first inner surface 133a (inner surface) and two inner surface 133b, and two second inner surfaces between them. It further has 133c, two third inner surfaces 133d, and two fourth inner surfaces 133e (see FIGS. 5B and C). The two second inner top surfaces 133c, the two third inner top surfaces 133d, and the two fourth inner top surfaces 133e are the first inner top surfaces in the direction in which the two exit surfaces 135 face each other (Y-axis direction). It is arranged so as to sandwich 133a.

The first inner top surface 133a is a surface arranged in the central portion of the recess 139 so as to intersect the optical axis LA of the light emitting element 131. The first inner top surface 133a is formed so that light emitted from the light emitting center of the light emitting element 131 at an angle of at least 0 ° or more and 10 ° or less is incident on the optical axis LA of the light emitting element 131. preferable. Further, the first inner top surface 133a is a light emitting element 131 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 between the two reflecting surfaces 134. It is preferable that the light emitting element 131 is formed so that the height from the light emitting surface increases as it approaches the optical axis LA. A plurality of first ridges 142 are arranged on the first inner top surface 133a in order to suppress color unevenness caused by the light emitting element 131 (see FIG. 5C).

When the plurality of first ridges 142 are viewed along the optical axis LA of the light emitting element 131 (when viewed along the Z-axis direction), the plurality of first ridges 142 have two ridges. The emission surface 135 is arranged so as to be substantially parallel to the opposite direction (Y-axis direction). The fact that the ridgeline of the first ridge 142 is substantially parallel to the direction in which the two emission surfaces 135 face each other (Y-axis direction) means that the ridgeline of the first ridge 142 is substantially parallel to the ridgeline of the first ridge 142 when viewed along the Z-axis direction. It means that the angle formed by the two emission surfaces 135 in the opposite direction (Y-axis direction) is 15 ° or less, preferably 0 °. That is, the direction in which the ridgeline of the first ridge 142 extends does not necessarily have to coincide with the Y-axis direction. From the boundary between the two reflecting surfaces 134 (or the virtual plane containing the optical axis LA (or the XZ plane including the X-axis and the Z-axis) set between the two reflecting surfaces 134) to each of the two emitting surfaces 135. It suffices if the plurality of first ridges 142 are formed so as to extend without intersecting with each other.

The cross-sectional shape of the first ridge 142 in the cross section perpendicular to the ridgeline of the first ridge 142 is not particularly limited, and may be a triangle, a rectangle (including a trapezoid), or a half. It may be circular, semi-elliptical, or corrugated. In the present embodiment, the cross-sectional shape of the first ridge 142 in the cross section perpendicular to the ridgeline of the first ridge 142 is a triangle (see FIGS. 6A and 6B).

The "ridge line" in the first ridge 142 means a linear chain of the highest portion (top) of the ridge, includes the optical axis LA of the light emitting element 131, and has a cross section parallel to the X-axis direction. A line connecting the vertices of the first convex strip 142. The number of "ridge lines" in the first ridge 142 may be one for each first ridge 142, or may be two or more. For example, when the cross-sectional shape of the first ridge 142 is a waveform, one line connecting the vertices of the wave becomes a ridge line. When the cross-sectional shape of the first ridge 142 is trapezoidal, there are two lines, one that connects one point of the two vertices of the trapezoid (the intersection of the upper base and the leg) and the other that connects the other points. Each line of is a ridgeline.

FIG. 7 is a graph showing the cross-sectional shape of the first inner top surface 133a in the cross section perpendicular to the ridgeline of the first ridge 142. In FIG. 7, the horizontal axis represents the distance d1 (distance in the X-axis direction; mm) from the center of the first inner top surface 133a, and the vertical axis is the height from the reference plane of the first inner top surface 133a. H1 (height in the Z-axis direction; mm) is shown. The reference plane is a line connecting the apex of the first ridge 142 and the midpoint of the valley bottom adjacent to the apex of the first ridge 142 in a cross section perpendicular to the ridgeline of the first ridge 142.

In the cross section perpendicular to the ridgeline of the first ridge 142, the distance a (distance in the X-axis direction) between the centers of the plurality of first ridges 142 may or may not be the same. From the viewpoint of suppressing color unevenness while realizing a desired light distribution, it is preferable that the distance a between the centers of the plurality of first ridges 142 is the same. The “distance between the centers of the plurality of first ridges 142 a” means the distance between the center lines of the plurality of first ridges 142 (see FIG. 7).

In the cross section perpendicular to the ridgeline of the first ridge 142, the height b (length in the Z-axis direction) of the plurality of first ridges 142 may or may not be the same. From the viewpoint of suppressing color unevenness while realizing a desired light distribution, it is preferable that the heights b of the plurality of first ridges 142 are the same. The "height b of the first ridge 142" is a straight line connecting the vertices of two adjacent first ridges 142 in a cross section perpendicular to the ridgeline of the first ridge 142, and the two first ridges. It means a length corresponding to half of the distance between the recess formed between 142 and the straight line connecting the valley bottoms of the two recesses formed on both sides thereof (see FIG. 7).

The ratio of the distance a between the centers of the plurality of first ridges 142 to the height b in the cross section perpendicular to the ridgeline of the first ridge 142 is a: b = 1: 0 to 1: 0.5. preferable. When a: b is within the above range, the traveling direction of the light incident on the first inner top surface 133a is likely to be slightly changed without significantly affecting the illuminance distribution on the light diffusing plate 150, which is desired. It is easy to suppress color unevenness while realizing light distribution. The distance a between the centers of the plurality of first ridges 142 should be 0.1 mm or more and 1 mm or less in consideration of the effect of improving color unevenness, the processing accuracy of the mold, and the transferability at the time of molding the luminous flux control member. preferable.

The height b of the first ridge 142 in the cross section perpendicular to the ridge of the first ridge 142 decreases as it approaches the two exit surfaces 135 (see FIGS. 5C, 6A and B). That is, 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 near the center of the first inner top surface 133a, contributes greatly 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 ridgeline direction of the first ridge 142, it is possible to easily change the traveling direction of the incident light. .. On the other hand, light emitted from the light emitting center of the light emitting element 131 at a large angle with respect to the optical axis LA of the light emitting element 131, for example, light incident on the side of the first inner top surface 133a closer to the emitting surface 135, has color unevenness. Contribution to small. Therefore, by lowering the height b of the first ridge 142 on the side closer to the two emission surfaces 135 in the ridgeline direction of the first ridge 142, the traveling direction of the incident light is not changed more than necessary. can do. As a result, it is possible to suppress color unevenness on the light emitting surface of the lighting device 100 and to prevent the light distribution characteristics of the light emitting device 130 from being impaired (see FIGS. 6A and 6B).

The height b of the first ridge 142 may be linearly lowered or curvedly lowered as it approaches the two exit surfaces 135. A linear decrease means that the slope of the ridgeline of the first ridge 142 is constant regardless of the position of the first ridge 142 in the ridgeline direction; a curve lower means that the slope of the ridgeline is constant. It means that the inclination of the ridgeline of 142 changes depending on the position of the first ridge 142 in the ridgeline direction. The inclination of the ridgeline of the first ridge 142 specifically means the inclination of the ridgeline in the cross section including the ridgeline of the first ridge 142. When the ridgeline in the cross section including the ridgeline of the first ridge 142 is a curve, the slope of the ridgeline at each position means the slope of the tangent line of the curve at each position. In the present embodiment, the height b of the first ridge 142 is linearly lowered as it approaches the two exit surfaces 135.

The region where the height b of the first ridge 142 becomes lower as it approaches the two exit surfaces 135 may be the entire or a part of the ridgeline direction of the first ridge 142. In the present embodiment, the region where the height b of the first ridge 142 becomes lower as it approaches the two exit surfaces 135 is the entire ridgeline direction of the first ridge 142.

The two reflecting surfaces 134 are arranged on the front side of the light flux control member 132, that is, on the side opposite to the light emitting element 131 (on the light diffusing plate 150 side) with the incident surface 133 interposed therebetween. Further, the two reflecting surfaces 134 have two directions (two emitting surfaces 135) in which a part of the light incident from the incident surface 133 is substantially perpendicular to the optical axis LA of the light emitting element 131 and is opposite to each other. Reflect in the opposite direction, that is, in the Y-axis direction. The two reflecting surfaces 134 include the optical axis LA of the light emitting element 131, and in a cross section parallel to the Y-axis direction, the end portion (emission) from the optical axis LA of the light emitting element 131 with the optical axis LA of the light emitting element 131 as a boundary. They are arranged so that the height from the bottom surface 138 (the substrate 120) increases toward the surface 135). Specifically, the two reflecting surfaces 134 are formed so that the inclination of the tangent line gradually decreases from the optical axis LA of the light emitting element 131 toward the end portion (emission surface 135) in the cross section. ..

The two emission surfaces 135 are arranged so as to face each other (in the Y-axis direction) with the two reflection surfaces 134 interposed therebetween. The two exit surfaces 135 are incident on the incident surface 133 (particularly the two inner surface 133b) and directly reach the exit surface 135, and are incident on the incident surface 133 (particularly the first inner surface 133a). The light reflected by the reflecting surface 134 is emitted 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. "Almost parallel to the optical axis LA" means that the smaller angle between 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. It means that. When the emission surface 135 is a curved surface, the smaller angle between the optical axis LA and the emission surface 135 is the curve of the optical axis LA and the emission surface 135 in the cross section. It means the smaller angle of the angle formed by the tangent line.

The collar portion 136 is located between the two emission surfaces 135 and the outer peripheral portion of the bottom surface 138 of the luminous flux control member 132, and projects outward with respect to the central axis CA. The shape of the crossguard 136 is substantially rectangular. The crossguard 136 is not an essential component, but the provision of the crossguard 136 facilitates the handling and alignment of the luminous flux control member 132. The thickness of the collar portion 136 is not particularly limited, and can be determined in consideration of the required area of the two exit surfaces 135, the formability of the collar portion 136, and the like.

The two leg portions 137 are substantially columnar members protruding from the bottom surface of the bottom surface 138 and the bottom portion of the flange portion 136 toward the light emitting element 131 on the outer peripheral portion of the bottom surface 138 (back surface) of the light flux control member 132. The two legs 137 support the luminous flux control member 132 at an appropriate position with respect to the light emitting element 131 (see FIG. 4C). The leg portion 137 may be fitted into a hole portion formed in the substrate 120 and used for positioning in a direction parallel to the XY plane. The number of legs 137 is not particularly limited.

(Action)
The operation of the luminous flux control member 132 according to the present embodiment will be described while comparing with the luminous flux control member for comparison. The luminous flux control member for comparison is configured in the same manner as the luminous flux control member according to the present embodiment, except that the first inner top surface 133a does not have a plurality of first ridges 142.

In the luminous flux control member (not shown) for comparison and the luminous flux control member 132 of the present embodiment, the light emitted from the light emitting element 131 is incident on the incident surface 133, and some of the light is incident on the two reflecting surfaces 134. After being reflected and traveling in two directions perpendicular to the optical axis LA of the light emitting element 131 and opposite to each other, the light is emitted to the outside from the two emission surfaces 135. The light emitted from the emission surface 135 is controlled to reach a position away from the light emitting device 130 of the light diffusing plate 150 (see FIGS. 4C and 5B).

In the luminous flux control member for comparison, the first inner top surface 133a is a smooth surface. Therefore, the light emitted at a small angle with respect to the optical axis LA of the light emitting element 131 (for example, an angle of at least 0 ° or more and 10 ° or less from the light emitting center of the light emitting element 131 with respect to the optical axis LA of the light emitting element 131) is emitted. Since the incident light is from a smooth surface, the light diffusing plate 150 can be easily reached by concentrating on a specific region without disturbing the traveling direction. As a result, the blue color in a specific region of the light emitting element 131 tends to be stronger than in other regions, and color unevenness tends to occur.

On the other hand, in the luminous flux control member 132 of the present embodiment, a plurality of first ridges 142 having ridges substantially parallel to the Y-axis direction are arranged on the first inner top surface 133a (see FIG. 5C). Moreover, the height of the first ridge 142 decreases as it approaches the exit surface 135 (see FIGS. 6A and 6B).
As a result, 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 near the center of the first inner top surface 133a (a large contribution to color unevenness). Since the traveling direction of the light is sufficiently changed by the first ridge 142, the light) can be concentrated in a specific region of the light diffusing plate 150 and difficult to reach. On the other hand, light emitted from the light emitting center of the light emitting element 131 at a large angle with respect to the optical axis LA of the light emitting element 131, for example, light incident near the ends of the two light emitting surfaces 135 on the side (the contribution to color unevenness is small). Since the traveling direction of the light cannot be changed more than necessary by the first ridge 142, the light distribution characteristics are not easily impaired. As a result, the light distribution characteristics of the light emitting device 130 can be less likely to be impaired than before while suppressing color unevenness on the light emitting surface of the lighting device 100.

In the first embodiment, the width (size in the X-axis direction) of the first ridge 142 is constant in the ridge direction of the first ridge 142 in the cross section perpendicular to the ridge of the first ridge 142. An example is shown (see FIGS. 5C, 6A and B), but is not limited to this and may not be constant. That is, even if the width (size in the X-axis direction) of the first ridge 142 in the cross section perpendicular to the ridgeline of the first ridge 142 is different between the AA line cross section and the BB line cross section. good.

8A to 8C are views showing a modified example of the cross-sectional shape of the first inner top surface 133a in the cross section perpendicular to the ridgeline of the first ridge 142. As shown in FIGS. 8A to 8C, in the cross section perpendicular to the ridgeline of the first ridge 142, the width c (size in the X-axis direction) of the first ridge 142 becomes smaller as it approaches the exit surface 135. May be good. As a result, the mold can be processed so that the apex angle of the first ridge 142 has the same size, which facilitates the production of the mold. The distance a between the centers of the plurality of first ridges 142 in the cross section perpendicular to the ridge of the first ridge 142 is constant (see FIGS. 8A to 8C).

Further, in the first embodiment, an example is shown in which the cross-sectional shape of the first ridge 142 is a triangle as shown in FIGS. 6A and 6B in the cross section perpendicular to the ridgeline of the first ridge 142. Not limited to this.

9A to 9F are views showing a modified example of the cross-sectional shape of the first inner top surface 133a in the cross section perpendicular to the ridgeline of the first ridge 142. That is, the cross-sectional shape of the first ridge 142 in the cross section perpendicular to the ridgeline of the first ridge 142 may be semi-circular or semi-elliptical (see FIGS. 9A and B, 9E and F), and has a waveform. It may be (see FIGS. 9C and D).

(Simulation 1)
Illuminance distribution and chromaticity Y on the light diffusing plate 150 of the lighting device 100 using the light flux control members A-1 (FIGS. 5C, 6A and B) or A-2 (FIGS. 8A to 8C) according to the present embodiment. The value was analyzed. The analysis of the illuminance distribution and the chromaticity Y value was performed using the lighting device 100 having only one light emitting device 130.
Further, for comparison, the light diffusing plate of the lighting device using the light flux control member (comparison) which is the same as the light flux control member A-1 or A-2 except that the first inner top surface 133a does not have a protrusion. The illuminance distribution and chromaticity Y value above were also analyzed.

The parameters of the luminous flux control members A-1 and A-2 were set as follows.

<Parameter of the first inner top surface 133a>
In the cross section perpendicular to the ridgeline of the first ridge 142, the cross-sectional shape of the first ridge 142 is a triangle. The distance a and the height b between the centers of the plurality of first ridges 142 in the cross section perpendicular to the ridge of the first ridge 142 are set as follows.
-Luminous flux control member A-1:
Distance between centers a: Height b = 1: 0.14 (A-A line cross section)
Distance between centers a = 500 μm, height b = 72 μm
The height b of the first ridge 142 gradually decreased as it approached the exit surface 135 in the Y-axis direction, and the height b in the BB line cross section was set to approach 0 μm.
・ Luminous flux control member A-2
Distance between centers a: Height b = 1: 0.14 (A-A line cross section)
Distance between centers a = 500 μm, height b = 72 μm
The height b of the first ridge 142 gradually decreased as it approached the exit surface 135 in the Y-axis direction, and the height b in the BB line cross section was set to approach 0 μm. Further, the width of the first ridge 142 is also set so as to gradually decrease as it approaches the exit surface 135 in the Y-axis direction, and the width in the BB line cross section approaches 0 μm.

<Other common parameters>
-Outer diameter of the luminous flux control member 132: length 11.1 mm in the Y-axis direction, length 9.2 mm in the X-axis direction
-Height of light emitting element 131: 0.75 mm
-Size of light emitting element 131: φ2.8 mm
-Space between the substrate 120 and the light diffusing plate 150: 50 mm

FIG. 10A is a graph showing the analysis result of the illuminance distribution on the light diffusing plate of the lighting device according to the present embodiment and the analysis result of the illuminance distribution on the light diffusing plate of the comparative lighting device. The horizontal axis of FIG. 10A indicates the distance d2 (distance in the Y-axis direction; mm) of the light emitting element 131 from the optical axis LA of the light diffusing plate 150, and the vertical axis represents the maximum distance of the light diffusing plate 150 at each distance. The relative illuminance when the illuminance is 1 is shown.
FIG. 10B is a graph showing the analysis result of the chromaticity Y value on the light diffusing plate of the lighting device according to the present embodiment and the analysis result of the chromaticity Y value on the light diffusing plate of the lighting device for comparison. .. The horizontal axis of FIG. 10B shows the distance d2 (distance in the Y-axis direction; mm) of the light emitting element 131 from the optical axis LA of the light diffusing plate 150, and the vertical axis shows the chromaticity Y value of the light diffusing plate 150. Shows.

As shown in FIG. 10A, the illuminance distribution of the lighting device using the light flux control member A-1 or A-2 according to the present embodiment shows that the spread of light in the Y-axis direction is a light flux control member for comparison. It is equivalent to the illuminance distribution of the lighting device used, and it can be seen that the light distribution characteristics are highly maintained.

Further, as shown in FIG. 10B, in the lighting device using the light flux control member for comparison, the valley bottom portion and the top portion adjacent to the valley bottom portion where the distance d2 from the optical axis LA of the light emitting element 131 is around 40 mm (specific region). The lighting device 100 using the luminous flux control member A-1 or A-2 according to the present embodiment has a large difference in chromaticity from (see the arrow in FIG. 10B) and causes bluish color unevenness. It can be seen that the difference in chromaticity between the valley bottom portion where the distance d2 of the light emitting element 131 from the optical axis LA is around 40 mm and the top portion adjacent thereto is small, and the color unevenness is reduced.

From these facts, it can be seen that the lighting device using the luminous flux control member according to the present embodiment can sufficiently suppress color unevenness on the light emitting surface of the lighting device 100 while maintaining a high degree of light distribution characteristics.

(effect)
As described above, in the luminous flux control member 132 according to the present embodiment, a plurality of first ridges 142 are arranged on the first inner top surface 133a, and the height of the first ridges 142 is the emission surface. It becomes lower as it approaches 135. As a result, among the light emitted from the light emitting element 131, the light emitted at a small angle with respect to the optical axis LA of the light emitting element 131 (light having a large contribution to color unevenness) is appropriately changed. Since the emission direction of other light (light that contributes less to color unevenness) is not changed more than necessary, it is possible to suppress color unevenness while maintaining the desired light distribution characteristics.

[Embodiment 2]
(Structure of luminous flux control member)
Next, with reference to FIG. 11, the luminous flux control member 132 according to the second embodiment will be described. 11A to 11D are views showing the configuration of the light flux control member according to the second embodiment. 11A is a plan view of the luminous flux control member 132, FIG. 11B is a cross-sectional view taken along the line 11B-11B of FIG. 11A, FIG. 11C is a bottom view, and FIG. 11D is a side view. 12A is a sectional view taken along line AA of the exit surface of FIG. 11D, and FIG. 12B is a sectional view taken along line BB of the exit surface of FIG. 11D. In the luminous flux control member 132 according to the present embodiment, instead of the incident surface 133 (first top surface 133a) having a plurality of first ridges 142, the two exit surfaces 135 have a plurality of second ridges 143. In that respect, it differs from the luminous flux control member 132 according to the first embodiment. Therefore, the same components as those of the luminous flux control member 132 according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the luminous flux control member 132 according to the present embodiment, a plurality of second ridges 143 are arranged on each of the two emission surfaces 135 (see FIG. 11D).

The cross-sectional shape of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 is not particularly limited, and may be corrugated, semicircular or semi-elliptical, or triangular. It may be a rectangle (including a trapezoid). In the present embodiment, the cross-sectional shape of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 is a triangle (see FIGS. 12A and 12B).

The second ridge 143 has a ridge line substantially parallel to the optical axis LA of the light emitting element 131 when viewed along a direction (Y-axis direction) in which the two emission surfaces 135 face each other. Approximately parallel means that the angle formed by the optical axis LA of the light emitting element 131 and the ridgeline of the second ridge 143 is 15 ° or less, preferably 0 °, when viewed along the Y-axis direction. .. In this way, the angle formed by the optical axis LA and the ridgeline of the second ridge 143 is minimized so that the molded product can be formed from the mold without having to make the molding mold of the luminous flux control member 132 having a complicated structure. This is so that it can be taken out without difficulty. If it is possible to adopt a mold structure that slides in a direction intersecting the taking-out direction of the molded product, it is possible to eliminate the limitation of the tilt angle with respect to the optical axis LA. Further, when the luminous flux control member 132 is mounted on the substrate 120, it is possible to greatly incline the angle formed by the optical axis LA and the ridgeline of the second convex ridge 143.

The "ridge line" in the second ridge 143 means a linear chain of the highest portion of the ridge, as described above, and the second ridge in the cross section perpendicular to the optical axis LA of the light emitting element 131. A line connecting the vertices of 143.

In the cross section perpendicular to the ridgeline of the second ridge 143, the distance a (distance in the X-axis direction) between the centers of the plurality of second ridges 143 may or may not be the same. From the viewpoint of suppressing color unevenness while realizing a desired light distribution, it is preferable that the distance a between the centers of the plurality of second ridges 143 is the same. The "distance between the centers of the plurality of second ridges 143 a" means the distance between the center lines of the plurality of second ridges 143 in the cross section perpendicular to the ridgeline of the second ridge 143, as described above. (See FIG. 13).

In the cross section perpendicular to the ridgeline of the second ridge 143, the height b (length in the Y-axis direction) of the plurality of second ridges 143 may or may not be the same. From the viewpoint of ease of mold processing, it is preferable that the height b of the plurality of second ridges 143 is the same. The "height b of the second ridge 143" is the straight line connecting the vertices of the two adjacent second ridges 143 in the cross section perpendicular to the ridgeline of the second ridge 143 and the two thereof, as described above. It means a length corresponding to half of the distance between the concave portion formed between the two second ridges 143 and the straight line connecting the valley bottoms of the two concave portions formed on both sides thereof (see FIG. 13).

The ratio of the distance a between the centers of the plurality of second ridges 143 to the height b in the cross section perpendicular to the ridgeline of the second ridge 143 is a: b = 1: 0 to 1: 0.5. preferable. When a: b is within the above range, the traveling direction of the light emitted from the emission surface 135 is likely to be slightly changed, so that it is easy to suppress color unevenness while realizing a desired light distribution. The distance a between the centers of the plurality of second ridges 143 shall be 0.1 mm or more and 2 mm or less in consideration of the effect of improving color unevenness, the processing accuracy of the mold, and the transferability at the time of molding the luminous flux control member 132. Is preferable.

The height b of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 decreases from the front side to the back side (see FIGS. 12A and 12B). That is, the 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 (light having a large contribution to color unevenness) is incident on the first inner top surface 133a and is a reflection surface. It is reflected by 134 and is likely to be emitted from a position near the upper ends (front side of the light flux control member 132) of the two emission surfaces 135. Therefore, the height b of the second ridge 143 near the front side (reflection surface 134 side) of the luminous flux control member 132 is increased so that the traveling direction of the light emitted from the emission surface 135 can be easily changed.
On the other hand, the light emitted from the light emitting center of the light emitting element 131 at a large angle with respect to the optical axis LA of the light emitting element 131 (light that contributes less to color unevenness) is, for example, the second inner top surface 133c or the third inner sky. After incident on the surface 133d, the fourth inner top surface 133e or the inner side surface 133b, it is easy to reach the lower ends of the two emission surfaces 135 (the back side of the light beam control member 132), and the lower ends (luminous flux) of the emission surface 135 are easily reached. It is easy to emit light from a place near (the back side of the control member 132). Therefore, the height b of the second ridge 143 on the side close to the back side (bottom surface 138 side) of the luminous flux control member 132 is lowered so that the traveling direction of the light emitted from the emission surface 135 does not change more than necessary. This ensures that the light distribution characteristics are not impaired. As a result, the light distribution characteristics of the light emitting device 130 can be less likely to be impaired than before while suppressing color unevenness on the light emitting surface of the lighting device 100 (see FIGS. 12A and 12B).

The height b of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 may be linearly lowered or curvedly lowered from the front side to the back side. As described above, linearly lowering means that the inclination of the ridgeline of the second ridge 143 is constant regardless of the position of the second ridge 143 in the ridgeline direction; , Means that the inclination of the ridgeline of the second ridge 143 changes depending on the position of the second ridge 143 in the ridgeline direction. The inclination of the ridgeline of the second ridge 143 specifically means the inclination of the ridgeline in the cross section including the ridgeline of the second ridge 143. When the ridgeline in the cross section including the ridgeline of the second ridge 143 is a curve, the slope of the ridgeline at each position means the slope of the tangent line of the curve at each position. In the present embodiment, the height b of the second ridge 143 is linearly lowered from the front side to the back side.

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

(Action)
In the luminous flux control member 132 of the present embodiment, a plurality of second ridges 143 having ridges substantially parallel to the optical axis LA (Z-axis direction) of the light emitting element 131 are arranged on the two emission surfaces 135. (See FIG. 11D). Further, the height of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 decreases from the front side to the back side (see FIGS. 12A and 12B). As a result, the 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 (light having a large contribution to color unevenness) is incident on the first inner top surface 133a and then is incident. It is reflected by the reflecting surface 134 and easily reaches the vicinity of the upper end portion of the emitting surface 135 (the front side of the light flux control member 132). The light that has reached the vicinity of the upper end of the emission surface 135 (the front side of the luminous flux control member 132) is appropriately changed in the traveling direction by the second ridge 143 (which has a high height), so that the light diffusing plate 150 is specified. It is possible to concentrate on the area of and prevent it from reaching.
On the other hand, the light emitted from the light emitting center of the light emitting element 131 at a large angle (light having a small contribution to color unevenness) with respect to the optical axis LA of the light emitting element 131 is incident on the inner surface 133b or the like and then emitted from the light emitting surface 135. It is easy to reach the vicinity of the lower end of the light beam (the back side of the luminous flux control member 132). The light that reaches the vicinity of the lower end of the emission surface 135 (the back side of the luminous flux control member 132) has a light distribution characteristic because the traveling direction of the light does not change more than necessary due to the (low height) second ridge 143. Hard to be damaged.
As a result, it is possible to suppress color unevenness on the light emitting surface of the lighting device 100 and prevent the light distribution characteristics of the light emitted from the light emitting element 131 from being impaired more than ever.

In the second embodiment, the width (size in the X-axis direction) of the second ridge 143 is constant in the ridge direction of the second ridge 143 in the cross section perpendicular to the ridge line of the second ridge 143. An example is shown (see FIGS. 11D, 12A and B), but is not limited to this and may not be constant. That is, even if the width (size in the X-axis direction) of the second ridge 143 in the cross section perpendicular to the ridge line of the second ridge 143 is different between the AA line cross section and the BB line cross section. good.

13A to 13C are views showing an example of deformation of the cross-sectional shape of the exit surface 135 in the cross section perpendicular to the ridgeline of the second ridge 143. As shown in FIGS. 13A to 13C, in the cross section perpendicular to the ridgeline of the second ridge 143, the width c (size in the X-axis direction) of the second ridge 143 may become smaller as it approaches the back side. .. As a result, the same effect as when the height is constant can be obtained. The distance a between the centers of the plurality of second ridges 143 in the cross section perpendicular to the ridgeline of the second ridge 143 is constant (see FIGS. 13A to 13C).

In the second embodiment, an example is shown in which the cross-sectional shape of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 is a triangle as shown in FIGS. 12A and 12B. Not limited to this.

14A to 14F are views showing a modified example of the cross-sectional shape of the exit surface 135 in the cross section perpendicular to the ridgeline of the second ridge 143. That is, the cross-sectional shape of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 may be corrugated (see FIGS. 14A to 14B), semicircular or semi-elliptical. Good (see FIGS. 14C to 14F).

(Simulation 2)
Illuminance distribution and color on the light diffusing plate 150 of the lighting device 100 using the light flux control members B-1 (FIGS. 11A to D, 12A and B) or B-2 (FIGS. 13A to 13C) according to the present embodiment. The degree Y value was analyzed.
Further, for comparison, a lighting device using a luminous flux control member (comparison 1) which is the same as the luminous flux control member B-1 or B-2 except that the emission surface 135 does not have a ridge, and a second in the Z-axis direction. 2 The chromaticity Y value on the light diffusing plate of the lighting device using the luminous flux control member (Comparison 2), which is the same as the luminous flux control member B-1 or B-2 except that the height of the ridges is constant. The illuminance distribution was also analyzed.

The parameters of the emission surface 135 of the luminous flux control members B-1 and B-2 were set as follows. Other common parameters were the same as in Simulation 1.

<Parameter of the exit surface 135>
The shape of the exit surface 135 having the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 is a triangle. Further, the distance a and the height b between the centers of the plurality of second ridges 143 in the cross section perpendicular to the ridgeline of the second ridge 143 are set as follows.
-Luminous flux control member B-1
Distance between centers a: Height b = 1: 0.13 (A-A line cross section)
Center-to-center distance a = 750 μm, height b = 100 μm
Height h of the exit surface 135 in the Z-axis direction (see FIG. 11D) = 3.9 mm
The height b of the second ridge 143 gradually decreased as it approached the bottom surface 138 in the Z-axis direction, and the height b in the BB line cross section was set to approach 0 μm.
・ Luminous flux control member B-2
Distance between centers a: Height b = 1: 0.15 (A-A line cross section)
Center-to-center distance a = 750 μm, height b = 110 μm
Height h of the exit surface 135 in the Z-axis direction (see FIG. 11D) = 3.9 mm
The height b of the second ridge 143 gradually decreased as it approached the bottom surface 138 in the Z-axis direction, and the height b in the BB line cross section was set to approach 0 μm. Further, the width of the second ridge 143 was also set so as to gradually decrease as it approached the bottom surface 138 in the Z-axis direction, and the width in the BB line cross section approached 0 μm.

FIG. 15A is a graph showing the analysis result of the illuminance distribution on the light diffusing plate of the lighting device according to the present embodiment and the analysis result of the illuminance distribution on the light diffusing plate of the comparative lighting device. The horizontal axis of FIG. 15A indicates the distance d2 (distance in the Y-axis direction; mm) of the light emitting element 131 from the optical axis LA of the light diffusing plate 150, and the vertical axis represents the maximum distance of the light diffusing plate 150 at each distance. The relative illuminance when the illuminance is 1 is shown.
FIG. 15B is a graph showing the analysis result of the chromaticity Y value on the light diffusing plate of the lighting device according to the present embodiment and the analysis result of the chromaticity Y value on the light diffusing plate of the lighting device for comparison. be. The horizontal axis of FIG. 15B shows the distance d2 (distance in the Y-axis direction; mm) of the light emitting element 131 from the optical axis LA of the light diffusing plate 150, and the vertical axis shows the chromaticity Y value of the light diffusing plate 150. Shows.

As shown in FIG. 15A, in the illuminance distribution of the lighting device using the light flux control member B-1 or B-2 according to the present embodiment, the spread of light in the Y-axis direction is the light flux control member for comparison. Compared with the illuminance distribution of the lighting device using the comparison 1), it is not significantly impaired, and it can be seen that the light distribution characteristics can be generally maintained. Further, it can be seen that the spread of light in the Y-axis direction is wider than the illuminance distribution of the lighting device using the light flux control member for comparison (Comparison 2), and the light distribution characteristics are not easily impaired (compared to Comparison 2). ..

Further, as shown in FIG. 15B, in the lighting device (comparison 1) using the light flux control member for comparison, the valley bottom portion where the distance d2 from the optical axis LA of the light emitting element 131 is around 40 mm and the top portion adjacent to the valley bottom portion (comparison 1). The lighting device 100 using the luminous flux control member B-1 or B-2 according to the present embodiment has a large difference in chromaticity from the arrow in FIG. 15B) and causes bluish color unevenness. It can be seen that the difference in chromaticity between the valley bottom portion where the distance d2 of the light emitting element 131 from the optical axis LA is around 40 mm and the top portion adjacent thereto is small, and the color unevenness is reduced. It can also be seen that the lighting device 100 using the luminous flux control member B-1 or B-2 according to the present embodiment can obtain the same color unevenness reduction effect as in Comparison 2.

From these facts, it can be seen that the lighting device using the luminous flux control member according to the present embodiment can sufficiently suppress color unevenness on the light emitting surface of the lighting device 100 while maintaining good light distribution characteristics.

(effect)
As described above, in the luminous flux control member 132 according to the present embodiment, a plurality of second ridges 143 are arranged on the two emission surfaces 135, and the height of the second ridges 143 increases from the front side to the back side. It is getting lower as you go. As a result, among the light emitted from the light emitting element 131, the light emitted at a small angle with respect to the optical axis LA of the light emitting element 131 (light having a large contribution to color unevenness) is appropriately changed. Since the emission direction of other light (light that contributes less to color unevenness) is not changed more than necessary, it is possible to suppress color unevenness while maintaining the desired light distribution characteristics.

[Embodiment 3]
(Structure of luminous flux control member)
Next, the luminous flux control member 132 according to the third embodiment will be described with reference to FIG. 16A to 16D are views showing the configuration of the luminous flux control member according to the third embodiment. 16A is a plan view of the luminous flux control member 132, FIG. 16B is a cross-sectional view taken along the line 16B-16B of FIG. 16A, FIG. 16C is a bottom view, and FIG. 16D is a side view. 17A is a sectional view taken along line AA of the first inner top surface 133a of FIG. 16C, and FIG. 17B is a sectional view taken along line BB of the first inner top surface 133a of FIG. 16C. The light flux control member 132 according to the present embodiment is related to the first embodiment in that the two emission surfaces 135 and the two reflection surfaces 134 are further provided with the second ridges 143 and the third ridges 144, respectively. It is different from the luminous flux control member 132. Therefore, the same components as those of the luminous flux control member 132 according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the luminous flux control member 132 according to the present embodiment, a plurality of second ridges 143 are further arranged on the two emission surfaces 135 (see FIG. 16D). The height b in the cross section perpendicular to the ridgeline of the second ridge 143 may be constant in the Z-axis direction, or may decrease as it approaches the bottom surface 138. In the present embodiment, the height b in the cross section perpendicular to the ridgeline of the second ridge 143 is constant in the Z-axis direction.

In the cross section perpendicular to the ridgeline of the second ridge 143, the cross-sectional shape of the emission surface 135 of the luminous flux control member 132 may be set to satisfy the equation (1).
hy = b × cos (2πdx / a) ・ ・ ・ Equation (1)
(A: Distance between centers (mm) of a plurality of second ridges 143,
b: Height (mm) of the second ridge 143,
dx: Distance from the center on the exit surface 135 (distance in the X-axis direction; mm),
hy: Height of the exit surface 135 from the reference surface (height in the Y-axis direction; mm))

The ratio of the distance a between the centers of the plurality of second ridges 143 to the height b in the cross section perpendicular to the ridgeline of the second ridge 143 is preferably a: b = 2: 1 to 13: 1. When a: b is within the above range, the light emitted from the two emission surfaces 135 can be slightly changed instead of being scattered, so that the desired light distribution can be achieved and the color can be changed. It is easy to suppress unevenness. Above all, the ratio of the distance a between the centers of the plurality of second ridges 143 and the height b is a: b = 5: 1 to 11: 1 from the viewpoint that not only the color unevenness can be suppressed but also the illuminance distribution can be further improved. It is more preferable that a: b = 5: 1 to 10: 1.

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

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

The region reached by the light incident on the first inner top surface 133a on the two reflecting surfaces 134 is, for example, a region on the two reflecting surfaces 134 in the vicinity of the optical axis LA of the light emitting element 131 (see FIG. 16A). .. When the third ridge 144 is viewed along the optical axis LA of the light emitting element 131 (when viewed along the Z-axis direction), the ridgeline thereof is in the direction in which the two exit surfaces 135 face each other (or the first). It is formed so as to be substantially perpendicular to the ridgeline of the ridge 142). Specifically, "substantially vertical" means that the angle between the direction in which the two emitting surfaces 135 face each other (or the ridgeline of the first ridge 142) and the ridgeline of the third ridge 144 is 90 ± 5 ° or less, preferably 90 ± 5 ° or less. It means that it is 90 °.

When the plurality of third ridges 144 are viewed along the optical axis LA of the light emitting element 131 (when viewed along the Z-axis direction), the ridgeline thereof is substantially relative to the ridgeline of the first ridge 142. It is formed so as to be vertical.

As described above, the "ridge line" in the third ridge 144 means a linear chain connecting the highest portions of the ridges, includes the optical axis LA of the light emitting element 131, and is parallel to the Y-axis direction. A line connecting the vertices of the third ridge 144 in a cross section. The plurality of third ridges 144 may be arranged so that their ridges are substantially parallel to the X-axis direction when viewed along the Z-axis direction (see FIG. 16A), or surround the optical axis LA. It may be arranged so as to be a part of an annular shape (not shown).

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

In the cross section perpendicular to the ridgeline of the third ridge 144, the distance a (distance in the Y-axis direction) between the centers of the plurality of third ridges 144 may or may not be the same. For example, in a cross section perpendicular to the ridgeline of the third ridge 144, even if the distance a between the centers of the plurality of third ridges 144 gradually decreases as the light emitting element 131 moves away from the optical axis LA in the Y-axis direction. good. The center-to-center distance a of the plurality of third ridges 144 includes the optical axis LA of the light emitting element 131 and is adjacent to the two third ridges 144 in a cross section parallel to the Y-axis direction. The distance between the center lines.

In the cross section perpendicular to the ridgeline of the third ridge 144, the height b (length in the Z-axis direction) of the plurality of third ridges 144 may or may not be the same. For example, in a cross section perpendicular to the ridgeline of the third ridge 144 (a cross section including the optical axis LA of the light emitting element 131 and parallel to the Y-axis direction), as the distance from the optical axis LA of the light emitting element 131 increases in the Y-axis direction, The height b of the third ridge 144 may be gradually reduced. The "height b of the third ridge 144" is a straight line connecting the vertices of two adjacent third ridges 144 in a cross section perpendicular to the ridgeline of the third ridge 144, and the two third ridges. It means a length corresponding to half of the distance between the recess formed between 144 and the straight line connecting the valley bottoms of the two recesses formed on both sides thereof.

(Action)
In the light beam control member 132 of the present embodiment, a plurality of first ridges 142 having ridges substantially parallel to the Y-axis direction are arranged on the first inner top surface 133a (see FIG. 16C), and two reflecting surfaces. A plurality of third ridges 144 having a ridge line substantially parallel to the X-axis direction are arranged on the 134 (see FIG. 16A), and a plurality of ridge lines having a ridge line substantially parallel to the Z-axis direction are arranged on the two exit surfaces 135. The second ridge 143 of the above is arranged (see FIG. 16D). As a result, the 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 the first ridge 142 of the incident surface 133, the third ridge 144 of the reflecting surface 134, and the light. Since the traveling directions of the light are appropriately changed by the second protrusions 143 of the emission surface 135, it is possible to prevent the light diffusing plate 150 from concentrating and reaching a specific region.

(Simulation 3)
Luminous flux control member C-1 (FIGS. 16A to D, FIGS. 17A and B) or C-2 (the shape of the first inner top surface 133a of C-1 is changed to FIGS. 8A to 8C) according to the present embodiment. The illuminance distribution and the chromaticity Y value on the light diffusing plate 150 of the lighting device 100 using (FIGS. 16A, B and D, FIGS. 8A to 8C) were analyzed.
Further, for comparison, the light diffusing plate of the lighting device using the light flux control member (comparison) which is the same as the light flux control member C-1 or C-2 except that the first inner top surface 133a does not have a protrusion. The illuminance distribution and chromaticity Y value above were also analyzed.

In the luminous flux control members C-1 (FIGS. 16A to D, FIGS. 17A and B) and C-2 (FIGS. 16A, B and D, FIGS. 8A to 8C), the parameters of the two reflecting surfaces 134 and the two emitting surfaces 135. The parameters were set as follows. In addition, the parameters and common parameters of the first inner top surface 133a were set in the same manner as in Simulation 1.

<Parameter of reflective surface 134>
The shape of the reflective surface 134 having the third ridge 144 in the cross section perpendicular to the ridge of the third ridge 144 was set as follows.

FIG. 18A is a graph showing the cross-sectional shape of the reflective surface 134 of the luminous flux control member C-1 or C-2 in the cross section perpendicular to the ridgeline of the third ridge 144. FIG. 18B is from the analysis result of the cross-sectional shape of the reflecting surface 134 of the light flux control members C-1 or C-2 of FIGS. 17A to 17D having the third ridge 144 in the cross section perpendicular to the ridgeline of the third ridge 144. , A graph showing the result (Δh1; mm) obtained by subtracting the analysis result of the cross-sectional shape of the reflective surface 134 of the luminous flux control member similar to the luminous flux control member C-1 or C-2 except that the third convex groove 144 is not provided. be.

The horizontal axis of FIGS. 18A and 18B shows the distance d2 (distance in the Y-axis direction; mm) of the light emitting element 131 from the optical axis LA. The vertical axis of FIG. 18A shows the height h1 (height in the Z-axis direction; mm) of the reflecting surface 134 from the bottom surface 138 with respect to the point where the optical axis LA of the light emitting element 131 intersects. The vertical axis of FIG. 18B is a cross section of the reflecting surface 134 of the light flux control member having no third ridge 144 from the cross-sectional shape of the reflecting surface 134 of the light flux controlling member C-1 or C-2 having the third ridge 144. The difference Δh1 (height in the Z-axis direction; mm) obtained by subtracting the shape is shown.
a: Distance between centers of the third ridge 144 (mm)
b: Height of the third ridge 144 (length in the Z-axis direction; mm)
Distance between centers of third ridge 144 a: height b = 20: 1
Distance a = 500 μm, height b = 25 μm between the centers of the third ridge 144

<Parameter of the exit surface 135>
The shape of the exit surface 135 having the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 was set so as to satisfy the above-mentioned equation (1). Further, the distance a and the height b between the centers of the plurality of second ridges 143 in the cross section perpendicular to the ridgeline of the second ridge 143 are set as follows. The height b of the second ridge 143 was set to be constant in the ridgeline direction.
Distance between centers a: Height b = 7.5: 1 (common to AA line and BB line cross section)
Center-to-center distance a = 750 μm, height b = 100 μm

FIG. 19A is a graph showing the analysis result of the illuminance distribution on the light diffusing plate of the lighting device according to the present embodiment and the analysis result of the illuminance distribution on the light diffusing plate of the comparative lighting device. The horizontal axis of FIG. 19A indicates the distance d2 (distance in the Y-axis direction; mm) of the light emitting element 131 from the optical axis LA of the light diffusing plate 150, and the vertical axis represents the maximum distance of the light diffusing plate 150 at each distance. The relative illuminance when the illuminance is 1 is shown.
FIG. 19B is a graph showing the analysis result of the chromaticity Y value on the light diffusing plate of the lighting device according to the present embodiment and the analysis result of the chromaticity Y value on the light diffusing plate of the lighting device for comparison. be. The horizontal axis of FIG. 19B shows the distance d2 (distance in the Y-axis direction; mm) of the light emitting element 131 from the optical axis LA of the light diffusing plate 150, and the vertical axis shows the chromaticity Y value of the light diffusing plate 150. Shows.

As shown in FIG. 19A, the illuminance distribution of the lighting device using the light flux control member C-1 or C-2 according to the present embodiment shows that the spread of light in the Y-axis direction is a light flux control member for comparison. It can be seen that it is equivalent to the lighting device used and maintains a high degree of light distribution characteristics.

Further, as shown in FIG. 19B, in the lighting device using the light flux control member for comparison, the valley bottom portion where the distance d2 of the light emitting element 131 from the optical axis LA is around 40 mm and the apex adjacent thereto (arrow in FIG. 19B). The difference in chromaticity from (see) is large and bluish color unevenness occurs, whereas the lighting device 100 using the luminous flux control member C-1 or C-2 is the distance from the optical axis LA of the light emitting element 131. It can be seen that the difference in chromaticity between the valley bottom where d2 is around 40 mm and the apex adjacent to it is small, and the color unevenness is particularly reduced.

From these facts, it can be seen that the lighting device using the luminous flux control member according to the present embodiment can sufficiently suppress color unevenness on the light emitting surface of the lighting device 100 while maintaining a high degree of light distribution characteristics.

(effect)
As described above, in the light flux control member 132 according to the present embodiment, a plurality of first ridges 142 are arranged on the first inner top surface 133a, and a plurality of second ridges 143 are arranged on the two exit surfaces 135. And a plurality of third protrusions 144 are arranged on the two reflecting surfaces 134. As a result, among the light emitted from the light emitting element 131 (rather than having a ridge on only one of the first inner top surface 133a, the emitting surface 135, and the reflecting surface 134), particularly the light emitting element 131. While making it easier to change the emission direction of light emitted at a small angle with respect to the optical axis LA (light with a large contribution to color unevenness), the emission direction of other light (light with a small contribution to color unevenness) is Since it is not changed more than necessary, it is possible to suppress color unevenness while maintaining the desired light distribution characteristics.

[Modification example]
In the first and third embodiments, in the luminous flux control member 132, a plurality of first ridges 142 are provided only on the first inner top surface 133a, but the present invention is not limited to this, and the first inner surface is not limited to this. It may be further provided on at least one of the second inner top surface 133c, the third inner top surface 133d, and the fourth inner top surface 133e other than the top surface 133a. Similarly, in embodiments 2 and 3, a plurality of second ridges 143 are provided on the entire surface of the exit surface 135, but the present invention is not limited to this, and the second ridges 143 are provided only on a part of the exit surface 135. May be

Further, in the first to third embodiments, in the luminous flux control member 132, a plurality of first ridges 142 (or second ridges 143) are provided on the flat first inner top surface 133a (or emission surface 135). However, the present invention is not limited to this, and may be provided on the first inner top surface 133a (or exit surface 135) which is a curved surface (for example, a concave surface).

Further, in the first to third embodiments, in the light flux control member 132, an example in which the inner surface shape of the concave portion 139 is a surface including an edge is shown, but the present invention is not limited to this, and a hemispherical shape, a semi-elliptical shape, or the like is shown. As such, it may be a curved surface that does not include edges. In that 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 can be continuously formed.

Further, in the first to third embodiments, in the luminous flux control member 132, the inner surface shape of the recess 139 has two second inner top surfaces in addition to the first inner top surface 133a (inner top surface) and the two inner surface 133b. An example of having 133c, two third inner surface 133d, and two fourth inner surface 133e is shown, but the present invention is not limited to this, and two second inner surface 133c and two third inner surface are shown. One or more of the surface 133d and the two fourth inner top surfaces 133e may be omitted.

Further, in the first to third embodiments, in the light beam control member 132 including the optical axis LA of the light emitting element 131 and in a cross section parallel to the Y-axis direction, the two emission surfaces 135 have the optical axis LA of the light emitting element 131. However, the present invention is not limited to this, and may be slightly inclined with respect to the optical axis LA of the 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, the emission surface 135 has a handleability when taking out a molded product from the mold as it moves away from the light emitting element 131 along the Z axis. If it is possible to form a mold structure so as not to damage the light emitting element 131, the light emitting element 131 may be inclined so as to be away from the optical axis LA. As a result, the amount of light refracted upward (direction toward the light diffusing plate 150) emitted from the exit surface 135 is reduced, so that it becomes easier to make the illuminance distribution and the color distribution uniform. The tilt angle of the emission surface 135 with respect to the optical axis LA of the light emitting element 131 in the cross section including the optical axis LA of the light emitting element 131 and parallel to the Y-axis direction can be, for example, 10 ° or less.

Further, in the first to third embodiments, in the lighting device 100, an example in which a plurality of light emitting devices 130 are arranged in one row is shown, but the present invention is not limited to this, and the lighting device 100 may be arranged in a plurality of rows or more.

Further, in the first to third embodiments, in the lighting device 100, a plurality of boards 120 are arranged for each light emitting device 130, and each board 120 is electrically connected to each other by a cable 140, but the present invention is limited to this. Instead, a plurality of light emitting devices 130 may be arranged on one substrate 120. In that case, the cable 140 and the caulking material 141 are unnecessary.

Further, in the first to third embodiments, in the lighting device 100, the housing 110 is a box-shaped body having a bottom plate, four side plates, and a top plate (at least partially provided with an opening). An example is shown, but the present invention is not limited to this, and at least the bottom plate may be provided, and the side plate and the top plate may be omitted.

FIG. 20 is a partially enlarged perspective view showing the configuration of the lighting device according to the modified example. As shown in FIG. 20, the top plate and the side plate of the housing 110 may be omitted, and the bottom plate of the housing 110 may be covered only with the light diffusing plate 150.

Further, in the first to third embodiments, the lighting device 100 is an example of a channel character signboard, but the present invention is not limited to this, and line lighting or the like may be used.

The lighting device having the luminous flux control member according to the present invention can be applied to, for example, a signboard (particularly a channel character signboard), line lighting, general lighting, and the like.

100 Lighting device 110 Housing 120 Board 130 Light emitting device 131 Light emitting element 132 Luminous flux control member 133 Incident surface 133a Inner top surface (first inner top surface)
133b Inner side surface 133c 2nd inner top surface 133d 3rd inner top surface 133e 4th inner top surface 134 Reflective surface 135 Exit surface 136 Crossguard 137 Legs 138 Bottom bottom 139 Recessed 140 Cable 141 Coking material 142 1st convex strip 143 2nd Convex 144 3rd Convex 150 Light Diffusing Plate CA Central Axis LA Optical Axis

Claims (11)

A luminous flux control member for controlling the light distribution of light emitted from a light emitting element.
The inner surface of the recess arranged on the back side, the incident surface on which the light emitted from the light emitting element is incident, and the incident surface.
Two reflecting surfaces arranged on the front side and reflecting a part of the light incident on the incident surface in two directions substantially perpendicular to the optical axis of the light emitting element and opposite to each other.
Two emitting surfaces that are arranged so as to face each other with the two reflecting surfaces interposed therebetween and emit light reflected by the two reflecting surfaces to the outside, respectively.
Have,
The incident surface has an inner surface of the recess and two inner surfaces that sandwich the inner surface of the recess and are arranged in a direction in which the two exit surfaces face each other.
On the inner surface, a plurality of first ridges having ridges substantially parallel to the directions in which the two emission surfaces face each other when viewed along the optical axis of the light emitting element are arranged.
The height of the first ridge in the cross section perpendicular to the ridgeline of the first ridge decreases as it approaches the two emission planes.
Luminous flux control member. A luminous flux control member for controlling the light distribution of light emitted from a light emitting element.
The inner surface of the recess arranged on the back side, the incident surface on which the light emitted from the light emitting element is incident, and the incident surface.
Two reflecting surfaces arranged on the front side and reflecting a part of the light incident on the incident surface in two directions substantially perpendicular to the optical axis of the light emitting element and opposite to each other.
Two emitting surfaces that are arranged so as to face each other with the two reflecting surfaces interposed therebetween and emit light reflected by the two reflecting surfaces to the outside, respectively.
Have,
A plurality of second ridges having a ridge line substantially parallel to the optical axis of the light emitting element are arranged on each of the two emission surfaces when viewed along the directions in which the two emission surfaces face each other. Ori,
The height of the second ridge in the cross section perpendicular to the ridgeline of the second ridge decreases as it approaches the back side.
Luminous flux control member. A plurality of second ridges having a ridge line substantially parallel to the optical axis of the light emitting element are arranged on each of the two emission surfaces when viewed along the directions in which the two emission surfaces face each other. Ori,
The height of the second ridge in the cross section perpendicular to the ridgeline of the second ridge decreases as it approaches the back side.
The luminous flux control member according to claim 1. At least a part of each of the two reflecting surfaces has a plurality of third protrusions having ridges substantially perpendicular to the direction in which the two emitting surfaces face each other when viewed along the optical axis of the light emitting element. Is placed,
The luminous flux control member according to any one of claims 1 to 3. In the direction of the ridgeline of the first ridge, the inclination of the ridgeline of the first ridge is constant.
The luminous flux control member according to claim 1. In the direction of the ridgeline of the second ridge, the inclination of the ridgeline of the second ridge is constant.
The luminous flux control member according to claim 2. The width of the first ridge in the cross section perpendicular to the ridge of the first ridge becomes smaller as it approaches the exit surface.
The luminous flux control member according to claim 1. The width of the second ridge in the cross section perpendicular to the ridge of the second ridge becomes smaller as it approaches the back side.
The luminous flux control member according to claim 2. With a light emitting element
The luminous flux control member according to any one of claims 1 to 8, wherein the incident surface is arranged so as to face the light emitting element.
A light emitting device. Light emitted from the light emitting 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.
The light emitting device according to claim 9. The light emitting device according to claim 9 or 10, and the light emitting device.
A light diffusing plate that diffuses and transmits the light emitted from the light emitting device,
Has a lighting device.

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