JP2020061330A - Light flux control member, light emitting device, and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: 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. A luminous flux control member comprises an incident surface, two reflecting surfaces that reflect a part of light incident on the incident surface in directions substantially perpendicular to the optical axis of a light emitting element, and two reflecting surfaces. It has two emitting surfaces arranged so as to be sandwiched from each other. The incident surface has an inner top surface of the recess and two inner surfaces arranged so as to sandwich the inner top surface. On the inner surface, a plurality of first protrusions having ridges substantially parallel to the directions in which the two exit surfaces face each other when viewed along the optical axis of the light emitting element are arranged, and the first convex The height of the strip decreases as it approaches the two exit surfaces. [Selection diagram] Fig. 6

Description

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

  A light emitting device having a light emitting element such as an LED is used as a light source of a lighting device or a signboard. 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 which are opposite to each other in the horizontal direction, so that the light distribution characteristic is anisotropic. A light emitting device (which exhibits an elliptical light distribution) is used.

  As a light emitting device having anisotropy in light distribution characteristics, for example, in Patent Document 1, as shown in FIG. 1, a light emitting element 12 and a reflection cup 14a for reflecting light emitted from the light emitting element 12 upward are shown. There is disclosed a light emitting device having a base (chip mounting lead) 14 having a light emitting element 12 and a light flux controlling member 13 (translucent resin in Patent Document 1) for sealing the light emitting element 12 and the reflection cup 14a. Light flux controlling member 13 has two reflecting surfaces 17 for reflecting the light emitted from light emitting element 12 and the light reflected by reflection cup 14a, and two emitting surfaces for emitting the light reflected by 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 reflection surface 17 of the light flux controlling 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 two reflecting surfaces 17 of light flux controlling member 13. Then, these lights that have reached the two reflecting surfaces 17 of the light flux controlling member 13 travel in mutually opposite directions in the horizontal direction and are emitted to the outside from the two emitting surfaces 19 of the light flux controlling member 13.

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

JP-A-9-18058

  In the SMD type light emitting element, the blue light emitted at a large angle with respect to the optical axis of the light emitting element propagates along the 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 is emitted as a bluish light because it is difficult to be converted into white light because it is emitted by traveling along a short optical path in the phosphor. Cheap. Not limited to such an SMD type light emitting element, a light emitting element that emits light with different tints depending on the emission direction is applied to a light emitting device having anisotropy in the light distribution characteristic as shown in Patent Document 1. Then, there is a problem that color unevenness is likely to occur between a region where light emitted at a small angle with respect to the optical axis of the light emitting element reaches and a region where light emitted at a large angle with respect to the optical axis reaches. It was Specifically, there is a problem that light emitted at a small angle with respect to the optical axis of the light emitting element is likely to be concentrated and reach a specific area of the light diffusion plate, and the blue color of the area is likely to appear strongly. .

  On the other hand, if it is attempted to suppress color unevenness, the light distribution characteristic tends to be impaired. Therefore, it is desired to suppress color unevenness without impairing the light distribution characteristic (while maintaining the light distribution characteristic at a high level).

  Then, the objective of this invention is providing the light flux control member which can suppress the color unevenness resulting from a light emitting element, 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 light flux controlling member.

  A light flux controlling member according to the present invention is a light flux controlling member for controlling light distribution of light emitted from a light emitting element, and is a light flux emitted from the light emitting element on an inner surface of a concave portion arranged on the back side. Is disposed on the front surface side of the incident surface on which light is incident, and reflects a part of the light incident on the incident surface in two directions which are substantially perpendicular to the optical axis of the light emitting element and opposite to each other. Two reflecting surfaces, and two emitting surfaces that are arranged to face each other with the two reflecting surfaces sandwiched therebetween and that respectively emit the light reflected by the two reflecting surfaces to the outside. , The inner top surface of the concave portion and two inner side surfaces that are arranged in a direction sandwiching the inner top surface of the concave portion and facing each other, and the inner top surface includes the light emitting element. The direction in which the two emission surfaces face each other when viewed along the optical axis of the device A plurality of first ridges having substantially parallel ridges are arranged, and the height of the first ridges in a cross section perpendicular to the ridges of the first ridges decreases as they approach the two emission surfaces. .

  A light flux controlling member according to the present invention is a light flux controlling member for controlling light distribution of light emitted from a light emitting element, and is a light flux emitted from the light emitting element on an inner surface of a concave portion arranged on the back side. Is disposed on the front surface side of the incident surface on which light is incident, and reflects a part of the light incident on the incident surface in two directions which are substantially perpendicular to the optical axis of the light emitting element and opposite to each other. Two reflecting surfaces, and two emitting surfaces that are arranged to face each other with the two reflecting surfaces sandwiched therebetween and that respectively emit the light reflected by the two reflecting surfaces to the outside. A plurality of second ridges each 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 a direction in which the two emission surfaces face each other. 2 Height of the second ridge in a cross section perpendicular to the ridgeline of the ridge , It lowers toward the rear side.

  A light emitting device according to the present invention includes a light emitting element and a light flux controlling member according to the present invention, wherein the incident surface is arranged so as to face the light emitting element.

  An illumination device according to the present invention includes a plurality of light emitting devices according to the present invention, and a light diffusion plate that diffuses and transmits light emitted from the light emitting devices.

  ADVANTAGE OF THE INVENTION According to this invention, the light flux control member which can suppress the color unevenness resulting from a light emitting element can be provided, 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 a configuration of the illumination device according to the first embodiment. FIG. 3 is a plan view of the illumination device with the light diffusion plate removed. 4A to 4C are diagrams showing the configuration around the light emitting device shown in FIG. 5A to 5D are diagrams showing the configuration of the light flux controlling member according to the first embodiment. 6A is a sectional view taken along the line AA of the first inner top surface of FIG. 5C, and FIG. 6B is a sectional view taken along the line BB of the first inner top surface of FIG. 5C. FIG. 7 is a graph showing a cross-sectional shape of the first inner top surface in a cross section perpendicular to the ridgeline of the first ridge. 8A to 8C are diagrams showing modified examples 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 diagrams showing modified examples 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 is an analysis result of the illuminance distribution on the light diffusion plate of the lighting device using the light flux controlling member according to the first embodiment, and an illuminance distribution on the light diffusion plate of the lighting device using the comparative light flux controlling member. 10B is a graph showing the analysis result of FIG. 10B, and FIG. 10B shows the analysis result of the chromaticity Y value on the light diffusion plate of the lighting device using the light flux controlling member according to the first embodiment, and the light flux controlling member for comparison. It is a graph which shows the analysis result of the chromaticity Y value on the light diffusion plate of the used illuminating device. 11A to 11D are diagrams showing the configuration of the light flux controlling member according to the second embodiment. 12A is a sectional view taken along the line AA of the emission surface of FIG. 11D, and FIG. 12B is a sectional view taken along the line BB of the emission surface of FIG. 11D. 13A to 13C are diagrams showing modified examples of the cross-sectional shape of the emission surface in the cross section perpendicular to the ridgeline of the second ridge. 14A to 14F are diagrams showing modified examples of the cross-sectional shape of the emission surface in a cross section perpendicular to the ridgeline of the second ridge. FIG. 15A is an analysis result of the illuminance distribution on the light diffusion plate of the lighting device using the light flux controlling member according to the second embodiment, and an illuminance distribution on the light diffusion plate of the lighting device using the comparative light flux controlling member. 15B is a graph showing the analysis result of FIG. 15B, and FIG. 15B shows the analysis result of the chromaticity Y value on the light diffusion plate of the lighting device using the light flux controlling member according to the second embodiment and the light flux controlling member for comparison. 9 is a graph showing the analysis result of the chromaticity Y value on the light diffusion plate of the lighting device. 16A to 16D are diagrams showing the configuration of the light flux controlling member according to the third embodiment. 17A is a cross-sectional view taken along the line AA of the first inner top surface of FIG. 16C, and FIG. 17B is a cross-sectional view taken along the 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 flux controlling member in a cross section perpendicular to the ridgeline of the third ridge, and FIG. 18B is a cross section perpendicular to the ridgeline of the third ridge. It is a graph which shows the result ((DELTA) h1) which deducted the design value of the cross-sectional shape of the reflection surface of the light flux control member which does not have the 3rd convex stripe from the design value of the cross-sectional shape of the reflection surface of the light flux control member which has a stripe. FIG. 19A is an analysis result of the illuminance distribution on the light diffusion plate of the lighting device using the light flux controlling member according to the third embodiment, and the illuminance distribution on the light diffusion plate of the lighting device using the comparative light flux controlling member. 19B is a graph showing the analysis result of FIG. 19B, and FIG. 19B shows the analysis result of the chromaticity Y value on the light diffusion plate of the lighting device using the light flux controlling member according to the third embodiment, and the light flux controlling member for comparison. 6 is a graph showing an analysis result of a chromaticity Y value on a light diffusing plate of an illuminating device using. FIG. 20 is a partially enlarged perspective view showing the configuration of the lighting device according to the modification.

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

[Embodiment 1]
(Structure of lighting device)
2A and 2B and FIG. 3 are diagrams showing the configuration of the illumination device 100 according to the first embodiment. FIG. 2A is a plan view of the lighting device 100, and FIG. 2B is a front view. FIG. 3 is a plan view of lighting device 100 according to the present embodiment with light diffusion plate 150 removed. 4A to 4C are diagrams showing the configuration around the light emitting device 130 shown in FIG. 4A is a perspective view around the light emitting device 130 shown in FIG. 3, FIG. 4B is a plan view of FIG. 4A, and FIG. 4C is a cross-sectional view taken along line 4C-4C of FIG. 4B. The illumination device 100 shown in the figure is used as, for example, a channel character signboard.

  As shown in FIGS. 2A, 2B, 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 diffusion plate 150.

  The housing 110 is a box-shaped body in which at least a part of one surface is opened to accommodate the plurality of substrates 120 and the plurality of light emitting devices 130 therein. In the present embodiment, housing 110 includes a bottom plate, a top plate that faces the bottom plate, and four side plates that connect the bottom plate and the top plate. An opening serving as a light emitting region is formed on the top plate. This opening is closed by the light diffusion 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 diffusion 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 polymethylmethacrylate (PMMA) or polycarbonate (PC), a metal such as stainless steel or aluminum, or the like.

  The shape of the housing 100 in plan view may be any shape. In the present embodiment, since it is used for a channel character billboard, etc., the shape of the housing 100 in 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 substrate 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 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 controlling member 132. Each of the plurality of light emitting devices 130 is arranged such that 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 along the normal 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 light emitted from 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 blue light emitted from the light emitting portion into white light can be used.

  The light flux controlling member 132 controls the light distribution of the light emitted from the light emitting element 131, 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, and Change in two directions that are opposite to each other. Light flux controlling member 132 is arranged such that its incident surface 133 faces light emitting element 131, and more specifically, its central axis CA coincides with optical axis LA of light emitting element 131 (see FIG. 4C). ). The “optical axis LA of the light emitting element 131” means a light beam at the center of a three-dimensional light flux emitted from the light emitting element 131. The "central axis CA of the light flux controlling member 132" refers to, for example, a two-fold symmetrical axis of symmetry.

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

  The material of light flux controlling member 132 is not particularly limited as long as it can pass light of a desired wavelength. For example, the material of light flux controlling member 132 is a light transmissive resin such as polymethylmethacrylate (PMMA), polycarbonate (PC), epoxy resin (EP), or glass.

  Lighting device 100 according to the present embodiment has a main feature in the configuration of light flux controlling member 132. Therefore, the light flux controlling member 132 will be described in detail separately.

  The cable 140 electrically connects the plurality of adjacent substrates 120 to each other. The connecting portion between the substrate 120 and the cable 140 is reinforced by 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 through the cable 140 to form a module, the plurality of light emitting devices 130 can be freely arranged according to the shape of the housing 110.

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

  The material of the light diffusion plate 150 is not particularly limited as long as it can diffuse and transmit the light emitted from the emission surface 135 of the light flux controlling member 132. For example, polymethyl methacrylate (PMMA), polycarbonate (PC), It is a light transmissive resin such as polystyrene (PS) and styrene / methyl methacrylate copolymer resin (MS). In order to impart the light diffusing property, 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 substantially directed to the optical axis LA of the light emitting element 131 so that the light flux controlling member 132 illuminates a wide range of the light diffusing plate 150. The light is emitted in the vertical direction and converted into light traveling in two directions (Y-axis directions in FIGS. 4A to 4C) that are opposite to each other. The light emitted from each light flux controlling member 132 is further diffused by the light diffusion plate 150 and emitted to the outside. Accordingly, it is possible to suppress color unevenness and illuminance unevenness of the illumination device 100.

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

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

  The incident surface 133 allows a part of the light emitted from the light emitting element 131 to enter. Incident surface 133 is the back surface of light flux controlling member 132, that is, the inner surface of recess 139 formed in the central portion of bottom surface 138. The shape of the inner surface of the recess 139 is not particularly limited, and may be a surface including an edge or a curved surface that does not include an edge such as a hemispherical shape or a semielliptic shape. In this 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 top surface 133a (inner top surface) and two inner side surfaces 133b, and two second inner top surfaces therebetween. 133c, two third inner top surfaces 133d, and two fourth inner top surfaces 133e are further included (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 emission 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 with 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 emission center of the light emitting element 131 at an angle of at least 0 ° and not more than 10 ° with respect to the optical axis LA of the light emitting element 131 is incident. preferable. In addition, the first inner top surface 133 a of the light emitting element 131 prevents light emitted at a small angle with respect to the optical axis LA of the light emitting element 131 from advancing to the boundary portion between the two reflecting surfaces 134. It is preferable that the height from the light emitting surface of the light emitting element 131 increases as the distance from the optical axis LA increases. 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 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 ridge lines. The emission surfaces 135 are arranged so as to be substantially parallel to the opposite direction (Y-axis direction). 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 when viewed along the Z-axis direction, It means that the angle formed by the direction in which the two emission surfaces 135 face each other (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 coincide with the Y-axis direction. From the boundary of the two reflecting surfaces 134 (or a virtual plane including the optical axis LA (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 is sufficient that the plurality of first ridges 142 are formed so as to extend toward each other without intersecting.

  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 or 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 connection of the highest portion (top portion) of the ridge, and includes the optical axis LA of the light emitting element 131, and in a cross section parallel to the X-axis direction, A line connecting the vertices of the first ridge 142. The number of “ridge lines” in the first ridges 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 corrugated, one line connecting the vertices of the wave becomes a ridge line. When the cross-sectional shape of the first ridge 142 is trapezoidal, two lines of one of the two vertices of the trapezoid (the intersection of the upper base and the leg) are connected, and the other line is connected. The lines are the ridgelines.

  FIG. 7 is a graph showing a cross-sectional shape of the first inner top surface 133a in a cross section perpendicular to the ridgeline of the first ridge 142. In FIG. 7, the horizontal axis represents the distance d1 (the distance in the X-axis direction; mm) from the center of the first inner top surface 133a, and the vertical axis represents the height of the first inner top surface 133a from the reference plane. The height h1 (height in the Z-axis direction; mm) is shown. The reference plane refers to a line that connects the apex of the first ridge 142 and the midpoint of the valley bottom next 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 center-to-center distances a (distance in the X-axis direction) of the plurality of first ridges 142 may or may not be the same. From the viewpoint of suppressing the color unevenness while realizing the desired light distribution, the center-to-center distances a of the plurality of first ridges 142 are preferably the same. The “center-to-center distance a of the plurality of first ridges 142” refers to the distance between the center lines of the plurality of first ridges 142 (see FIG. 7).

  In a cross section perpendicular to the ridgeline of the first ridge 142, the heights b (lengths in the Z-axis direction) of the plurality of first ridges 142 may or may not be the same. From the viewpoint of suppressing the color unevenness while realizing the desired light distribution, it is preferable that the heights b of the plurality of first ridges 142 be the same. The "height b of the first ridge 142" means 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 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 center-to-center distance a of the plurality of first ridges 142 to the height b in the cross section perpendicular to the ridgeline of the first ridges 142 may be 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 diffusion plate 150, and therefore, it is desired. It is easy to suppress color unevenness while achieving light distribution. The center-to-center distance a of the plurality of first ridges 142 is 0.1 mm or more and 1 mm or less in consideration of the effect of improving the color unevenness, the processing accuracy of the mold, and the transferability when the light flux controlling member is molded. preferable.

  The height b of the first ridge 142 in the cross section perpendicular to the ridgeline of the first ridge 142 decreases as it approaches the two emission surfaces 135 (see FIGS. 5C, 6A, and B). That is, the light emitted from the light emission center of the light emitting element 131 at a small angle with respect to the optical axis LA of the light emitting element 131, particularly the light incident near the center of the first inner top surface 133a, has a large contribution 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, the light emitted from the light emission 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, the light incident on the side closer to the emission surface 135 of the first inner ceiling surface 133a has uneven color. Contribution to Therefore, by lowering the height b of the first ridge 142 on the side closer to the two emission surfaces 135 in the ridge direction of the first ridge 142, the traveling direction of the incident light is not changed more than necessary. can do. Thereby, it is possible to suppress the color unevenness on the light emitting surface of the lighting device 100 and 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 curvilinearly lowered as it approaches the two emission surfaces 135. The linear decrease means that the inclination of the ridgeline of the first ridge 142 is constant irrespective of the position of the first ridge 142 in the ridge direction; the curvilinear decrease means the first ridge. This means that the inclination of the ridgeline of the 142 changes depending on the position of the first ridge 142 in the ridgeline direction. In addition, the inclination of the ridgeline of the first ridge 142 specifically refers to the inclination of the ridgeline in a 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 refers to the slope of the tangent to the curve at each position. In the present embodiment, the height b of the first ridge 142 linearly decreases as it approaches the two emission surfaces 135.

  The region where the height b of the first ridge 142 decreases as it approaches the two emission surfaces 135 may be the entire ridge line direction of the first ridge 142 or a part thereof. In the present embodiment, the region in which the height b of the first ridge 142 decreases as it approaches the two emission surfaces 135 is the entire ridge line direction of the first ridge 142.

  The two reflecting surfaces 134 are arranged on the front side of the light flux controlling member 132, that is, on the side opposite to the light emitting element 131 (on the side of the light diffusing plate 150) with the entrance surface 133 interposed therebetween. In addition, the two reflecting surfaces 134 partially reflect the light incident from the incident surface 133 in two directions that are substantially perpendicular to the optical axis LA of the light emitting element 131 and are opposite to each other (the two emitting surfaces 135 are The light is reflected in the opposite direction, that is, the Y-axis direction. The two reflecting surfaces 134 include the optical axis LA of the light emitting element 131, and in the cross section parallel to the Y-axis direction, with the optical axis LA of the light emitting element 131 as a boundary, end portions (emission) from the optical axis LA of the light emitting element 131. The heights from the bottom surface 138 (the substrate 120) are increased toward the surface 135). Specifically, in the cross section, the two reflecting surfaces 134 are formed such that the inclination of the tangent line gradually decreases from the optical axis LA of the light emitting element 131 toward the end (emission surface 135). .

  The two emission surfaces 135 are arranged 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 entrance surface 133 (particularly the two inner side surfaces 133b) and directly reach the exit surface 135, and are incident on the entrance surface 133 (particularly the first inner top surface 133a). The light reflected by the reflecting surface 134 is emitted to the outside.

  The emission surface 135 may be a flat surface or a curved surface. In the present embodiment, the emission surface 135 is a surface that is substantially parallel to the optical axis LA. The phrase “substantially parallel to the optical axis LA” means that, in a cross section including the optical axis LA and parallel to the Y-axis direction, the smaller one of the angles formed by the optical axis LA and the emission surface 135 is 3 ° or less. Means that. In the case where the emission surface 135 is a curved surface, the smaller angle between the optical axis LA and the emission surface 135 is smaller than that of the curved line in the cross section of the optical axis LA and the emission surface 135. The smaller of the angles formed by the tangents.

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

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

(Action)
The operation of light flux controlling member 132 according to the present embodiment will be described in comparison with a light flux controlling member for comparison. The light flux controlling member for comparison has the same configuration as the light flux controlling member according to the present embodiment, except that the first inner top surface 133a does not have the plurality of first ridges 142.

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

  In the light flux controlling member for comparison, first inner top surface 133a is a smooth surface. Therefore, light emitted at a small angle with respect to the optical axis LA of the light emitting element 131 (for example, an angle of at least 0 ° and 10 ° or less with respect to the optical axis LA of the light emitting element 131 from the light emission center of the light emitting element 131) Since the light is incident from the smooth surface, it is easy to concentrate and reach a specific region of the light diffusion plate 150 without disturbing the traveling direction. As a result, the blue color in a specific region of the light emitting element 131 is more likely to appear than in other regions, and color unevenness is likely to occur.

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

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

  8A to 8C are diagrams showing modified examples 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 emission surface 135. Good. This makes it possible to process the mold so that the apex angles of the first ridges 142 have the same size, which facilitates the manufacture of the mold. The center-to-center distance a of the plurality of first ridges 142 in the cross section perpendicular to the ridgeline of the first ridges 142 is constant (see FIGS. 8A to 8C).

  Further, in the first embodiment, the example 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 is shown. It is not limited to this.

  9A to 9F are diagrams showing modified examples 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 a semicircle or a semi-ellipse (see FIGS. 9A and B, 9E and F), or a waveform. (See FIGS. 9C and D).

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

  The parameters of light flux controlling members A-1 and A-2 were set as follows.

<Parameters 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 was a triangle. The center-to-center distances a and the heights b of the plurality of first ridges 142 in the cross section perpendicular to the ridgeline of the first ridges 142 were set as follows.
Light flux control member A-1:
Center-to-center distance a: height b = 1: 0.14 (A-A line cross section)
Center distance a = 500 μm, height b = 72 μm
The height b of the first ridge 142 is set to gradually decrease as it approaches the emission surface 135 in the Y-axis direction, and the height b in the cross section along the line BB approaches 0 μm.
・ Light flux control member A-2
Center-to-center distance a: height b = 1: 0.14 (A-A line cross section)
Center distance a = 500 μm, height b = 72 μm
The height b of the first ridge 142 is set to gradually decrease as it approaches the emission surface 135 in the Y-axis direction, and the height b in the cross section along the line BB approaches 0 μm. The width of the first ridge 142 is also set to gradually decrease as it approaches the emitting surface 135 in the Y-axis direction, and the width in the cross section along the line BB approaches 0 μm.

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

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

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

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

  From these, it is understood that the lighting device using the light flux controlling member according to the present embodiment can sufficiently suppress the color unevenness on the light emitting surface of the lighting device 100 while maintaining the high light distribution characteristics.

(effect)
As described above, in light flux controlling member 132 according to the present embodiment, a plurality of first ridges 142 are arranged on first inner top surface 133a, and the height of first ridges 142 is equal to the emission surface. It becomes lower as it approaches 135. As a result, among the light emitted from the light emitting element 131, particularly 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. However, the emission direction of the other light (the light that contributes less to the color unevenness) is not changed more than necessary, so that the color unevenness can be suppressed while maintaining the desired light distribution characteristics.

[Second Embodiment]
(Structure of light flux controlling member)
Next, referring to FIG. 11, light flux controlling member 132 according to the second embodiment will be described. 11A to 11D are diagrams showing the configuration of the light flux controlling member according to the second embodiment. 11A is a plan view of light flux controlling member 132, FIG. 11B is a cross-sectional view taken along 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 the line AA of the emission surface of FIG. 11D, and FIG. 12B is a sectional view taken along the line BB of the emission surface of FIG. 11D. In light flux controlling member 132 according to the present embodiment, two exit surfaces 135 have a plurality of second ridges 143 instead of incidence surface 133 (first top surface 133a) having a plurality of first ridges 142. This is different from light flux controlling member 132 according to the first embodiment in points. Therefore, the same components as those of light flux controlling member 132 according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

  In light flux controlling member 132 according to the present embodiment, a plurality of second ridges 143 are respectively arranged on 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. Or 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 that is substantially parallel to the optical axis LA of the light emitting element 131 when viewed along the direction in which the two emission surfaces 135 face each other (Y-axis direction). The term “substantially 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 convex strip 143 is made as small as possible, even if the molding die for the light flux controlling member 132 does not have a complicated structure. This is so that it can be taken out easily. If it is possible to adopt a mold structure that slides in a direction that intersects with the take-out direction of the molded product, it is possible to eliminate the limitation on the angle of inclination with respect to the optical axis LA. Further, when mounting light flux controlling member 132 on substrate 120, it is possible to greatly incline the angle formed by optical axis LA and the ridge of second ridge 143.

  The “ridge line” in the second ridge 143 means a linear connection 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 center-to-center distances a (distance in the X-axis direction) of the plurality of second ridges 143 may or may not be the same. From the viewpoint of suppressing the color unevenness while realizing the desired light distribution, the center-to-center distances a of the plurality of second ridges 143 are preferably the same. The “center-to-center distance a of the plurality of second ridges 143” 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 ridges 143, as described above. (See Figure 13).

  In a cross section perpendicular to the ridgeline of the second ridges 143, the heights b (lengths in the Y-axis direction) of the plurality of second ridges 143 may be the same or different. From the viewpoint of ease of mold processing, it is preferable that the heights b of the plurality of second ridges 143 are the same. The “height b of the second ridge 143” means a straight line connecting the vertices of two adjacent second ridges 143 in a cross section perpendicular to the ridge of the second ridge 143, as in the above description. This means a length corresponding to half the distance between the recess formed between the two second ridges 143 and the straight line connecting the valley bottoms of the two recesses formed on both sides of the recess (see FIG. 13).

  The ratio of the center-to-center distance a of the plurality of second ridges 143 to the height b in the cross section perpendicular to the ridgeline of the second ridges 143 may be 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, and thus it is easy to suppress the color unevenness while realizing the desired light distribution. The center-to-center distance a of the plurality of second ridges 143 is 0.1 mm or more and 2 mm or less in consideration of the effect of improving the color unevenness, the processing accuracy of the mold, and the transferability when the light flux controlling member 132 is molded. Is preferred.

The height b of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 decreases as it approaches the back side from the front side (see FIGS. 12A and 12B). That is, light emitted from the light emission center of the light emitting element 131 at a small angle with respect to the optical axis LA of the light emitting element 131 (light having a large contribution to color unevenness) is incident on the first inner top surface 133a and is reflected on the reflecting surface. The light is reflected by 134 and is likely to be emitted from a location near the upper ends of the two emission surfaces 135 (front side of light flux controlling member 132). Therefore, the height b of the second ridge 143 near the front side (reflection surface 134 side) of the light flux controlling member 132 is increased to facilitate changing the traveling direction of the light emitted from the emission surface 135.
On the other hand, the light emitted from the light emission 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 little to color unevenness) is, for example, the second inner top surface 133c or the third inner top surface. After being incident on the surface 133d, the fourth inner top surface 133e, or the inner side surface 133b, it is easy to directly reach the lower end portions of the two emission surfaces 135 (the back side of the light flux controlling member 132), and The light is likely to be emitted from a portion near the control member 132 (the back side). Therefore, the height b of the second ridge 143 on the side closer to the back side (bottom surface 138 side) of the light flux controlling 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 prevents the light distribution characteristic from being impaired. Accordingly, it is possible to suppress color unevenness on the light emitting surface of the lighting device 100 and make it more difficult to impair the light distribution characteristics of the light emitting device 130 (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. The linear 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 as described above; , The inclination of the ridgeline of the second ridge 143 changes depending on the position of the second ridgeline 143 in the ridgeline direction. The inclination of the ridgeline of the second ridge 143 specifically refers to the inclination of the ridgeline in a 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 refers to the slope of the tangent to the curve at each position. In the present embodiment, the height b of the second ridge 143 linearly decreases from the front side to the back side.

  The region where the height b of the second ridge 143 decreases as it approaches the back side may be the entire ridge line direction of the second ridge 143 or a part thereof. In the present embodiment, the region in which the height b of the second ridge 143 decreases toward the back side is the entire area in the ridge line direction of the second ridge 143.

(Action)
In light flux controlling member 132 of the present embodiment, a plurality of second ridges 143 having ridge lines substantially parallel to optical axis LA (Z axis direction) of light emitting element 131 are arranged on two emission surfaces 135. (See Figure 11D). Further, the height of the second ridge 143 in the cross section perpendicular to the ridgeline of the second ridge 143 decreases as it approaches the back side from the front side (see FIGS. 12A and 12B). As a result, light emitted from the light emission center of the light emitting element 131 at a small angle with respect to the optical axis LA of the light emitting element 131 (light having a large contribution to color unevenness) is incident on the first inner top surface 133a and then The light is reflected by the reflecting surface 134 and easily reaches the vicinity of the upper end of the emitting surface 135 (front side of the light flux controlling member 132). The light reaching the vicinity of the upper end of the emission surface 135 (the front side of the light flux controlling member 132) is appropriately changed in the traveling direction by the (high) second ridges 143, so that the light diffusion plate 150 can be identified. It is possible to avoid reaching the area of.
On the other hand, the light emitted from the light emission 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 side surface 133 b and then on the emission surface 135. It is easy to reach the vicinity of the lower end portion (back side of light flux controlling member 132). The light reaching the vicinity of the lower end portion of the emission surface 135 (the back side of the light flux controlling member 132) does not change the traveling direction of the light more than necessary due to the second protrusions 143 (having a low height), so that the light distribution characteristic is Hard to be damaged.
Accordingly, it is possible to suppress color unevenness on the light emitting surface of the illumination 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, in the cross section perpendicular to the ridgeline of the second ridge 143, the width of the second ridge 143 (size in the X-axis direction) is constant in the ridgeline direction of the second ridge 143. Although an example is shown (see FIGS. 11D, 12A and B), the present invention 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 ridgeline of the second ridge 143 is different between the AA line cross section and the BB line cross section. Good.

  13A to 13C are diagrams showing modified examples of the cross-sectional shape of the emission surface 135 in a cross section perpendicular to the ridgeline of the second ridge 143. As shown in FIGS. 13A to 13C, in a 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 toward the back side. . Thereby, the same effect as when the height is constant is obtained. The center-to-center distance a of the plurality of second ridges 143 in the cross section perpendicular to the ridge of the second ridge 143 is constant (see FIGS. 13A to 13C).

  In the second embodiment, an example 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 has been shown. It is not limited to this.

  14A to 14F are diagrams showing modified examples of the cross-sectional shape of the emission surface 135 in a cross section perpendicular to the ridgeline of the second convex stripe 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 and 14B), or may be semicircular or semielliptical. Good (see Figures 14C-F).

(Simulation 2)
Illuminance distribution and color on the light diffusion plate 150 of the illumination device 100 using the light flux controlling member B-1 (FIGS. 11A to D, 12A and B) or B-2 (FIGS. 13A to 13C) according to the present embodiment. The Y value was analyzed.
For comparison, an illumination device using a light flux controlling member (Comparison 1) which is similar to light flux controlling member B-1 or B-2 except that emission surface 135 does not have a convex stripe, and a first illumination device in the Z-axis direction. 2 The chromaticity Y value on the light diffusion plate of the illuminating device using the light flux controlling member (Comparison 2) which is the same as the light flux controlling member B-1 or B-2 except that the height of the ridges is fixed. The illuminance distribution was also analyzed.

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

<Parameters of emission surface 135>
The shape of the emission surface 135 having the second ridges 143 in the cross section perpendicular to the ridgeline of the second ridges 143 was a triangle. The center-to-center distances a and the heights b of the plurality of second ridges 143 in the cross section perpendicular to the ridgeline of the second ridges 143 are set as follows.
.Light flux controlling member B-1
Center-to-center distance a: Height b = 1: 0.13 (A-A line cross section)
Center distance a = 750 μm, height b = 100 μm
Height h of the emission surface 135 in the Z-axis direction (see FIG. 11D) = 3.9 mm
The height b of the second ridge 143 gradually decreases as it approaches the bottom surface 138 in the Z-axis direction, and the height b in the BB line cross section is set to approach 0 μm.
.Light flux controlling member B-2
Center-to-center distance a: height b = 1: 0.15 (A-A line cross section)
Center distance a = 750 μm, height b = 110 μm
Height h of the emission surface 135 in the Z-axis direction (see FIG. 11D) = 3.9 mm
The height b of the second ridge 143 gradually decreases as it approaches the bottom surface 138 in the Z-axis direction, and the height b in the BB line cross section is set to approach 0 μm. Also, the width of the second ridge 143 was set so as to gradually decrease as it approaches the bottom surface 138 in the Z-axis direction, and the width in the BB line cross section approaches 0 μm.

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

  As shown in FIG. 15A, in the illuminance distribution of the illumination device using light flux controlling member B-1 or B-2 according to the present embodiment, the spread of light in the Y-axis direction is a light flux controlling member for comparison ( Compared with the illuminance distribution of the illuminating 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 illumination device using the comparative light flux controlling member (Comparison 2), and the light distribution characteristics are less likely to be impaired (compared to Comparison 2). .

  Further, as shown in FIG. 15B, in the illuminating device using the light flux controlling member for comparison (Comparison 1), 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 portion adjacent thereto ( (See the arrow in FIG. 15B), a large chromaticity difference occurs, and bluish color unevenness occurs, whereas the illumination device 100 using the light flux controlling member B-1 or B-2 according to the present embodiment is It can be seen that the difference in chromaticity between the valley bottom and the apex adjacent thereto at a distance d2 of the light emitting element 131 from the optical axis LA in the vicinity of 40 mm is small, and color unevenness is reduced. It is also understood that the illumination device 100 using the light flux controlling member B-1 or B-2 according to the present embodiment can obtain the color unevenness reducing effect equivalent to that of the comparison 2.

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

(effect)
As described above, light flux controlling member 132 according to the present embodiment has a plurality of second ridges 143 arranged on two emission surfaces 135, and the height of 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, particularly 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. However, the emission direction of the other light (the light that contributes less to the color unevenness) is not changed more than necessary, so that the color unevenness can be suppressed while maintaining the desired light distribution characteristics.

[Third Embodiment]
(Structure of light flux controlling member)
Next, referring to FIG. 16, light flux controlling member 132 according to the third embodiment will be described. 16A to 16D are diagrams showing the configuration of the light flux controlling member according to the third embodiment. 16A is a plan view of light flux controlling member 132, FIG. 16B is a cross-sectional view taken along line 16B-16B of FIG. 16A, FIG. 16C is a bottom view, and FIG. 16D is a side view. 17A is a cross-sectional view of the first inner top surface 133a of FIG. 16C taken along the line AA, and FIG. 17B is a cross-sectional view of the first inner top surface 133a of FIG. 16C taken along the line BB. Light flux controlling member 132 according to the present embodiment relates to Embodiment 1 in that second emitting surface 135 and two reflecting surfaces 134 are further provided with second convex line 143 and third convex line 144, respectively. It is different from light flux controlling member 132. Therefore, the same components as those of light flux controlling member 132 according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

  In light flux controlling member 132 according to the present embodiment, a plurality of second ridges 143 are further arranged on two emission surfaces 135 (see FIG. 16D). The height b of the second ridge 143 in the cross section perpendicular to the ridgeline 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.

The cross-sectional shape of the emission surface 135 of the light flux controlling member 132 can be set so as to satisfy the expression (1) in the cross section perpendicular to the ridgeline of the second ridge 143.
hy = b × cos (2πdx / a) Equation (1)
(A: center distance (mm) of the plurality of second ridges 143,
b: height (mm) of the second ridge 143,
dx: distance from the center of the emission surface 135 (distance in X-axis direction; mm),
hy: Height of the emission surface 135 from the reference surface (height in the Y-axis direction; mm))

  The ratio of the center-to-center distance a of the plurality of second ridges 143 to the height b in the cross section perpendicular to the ridgeline of the second ridges 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 in the traveling direction instead of being scattered, so that a desired light distribution can be achieved while achieving the desired color distribution. Easy to suppress unevenness. Above all, from the viewpoint that not only color unevenness can be suppressed but also the illuminance distribution can be further improved, the ratio of the center-to-center distance a of the plurality of second ridges 143 to the height b is a: b = 5: 1 to 11: 1. Is more preferable, and a: b = 5: 1 to 10: 1 is further preferable.

  In the cross section perpendicular to the ridge of the second ridge 143, the center-to-center distance a 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. Among them, when the ratio of the center-to-center distance a of the plurality of second ridges 143 to the height b is a: b = 5: 1 to 10: 1, the center-to-center distance a of the plurality of second ridges 143 is More preferably, it is more than 0.125 mm and not more than 2.000 mm.

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

  The area where the light incident on the first inner top surface 133a reaches on the two reflecting surfaces 134 is, for example, an area near the optical axis LA of the light emitting element 131 on the two reflecting surfaces 134 (see FIG. 16A). . The third ridge 144 has a ridge line in a direction in which the two emission surfaces 135 face each other when viewed along the optical axis LA of the light emitting element 131 (when viewed along the Z-axis direction) (or in the first direction). It is formed so as to be substantially perpendicular to the ridgeline of the ridge 142. The term “substantially perpendicular” specifically means that the angle between the direction in which the two emission 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 It means 90 °.

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

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

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

  In the cross section perpendicular to the ridgeline of the third ridge 144, the center-to-center distances a (distances in the Y-axis direction) of the plurality of third ridges 144 may or may not be the same. For example, in the cross section perpendicular to the ridgeline of the third ridge 144, the center-to-center distance a of the plurality of third ridges 144 may gradually decrease as the distance from the optical axis LA of the light emitting element 131 increases in the Y-axis direction. Good. The center-to-center distances a of the plurality of third ridges 144 are similar to those described above, and in the cross section including the optical axis LA of the light emitting element 131 and being parallel to the Y-axis direction, the two third ridges 144 adjacent to each other. The distance between centerlines.

  In a cross section perpendicular to the ridgeline of the third ridge 144, the heights b (lengths 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 (a cross section including the optical axis LA of the light emitting element 131 and parallel to the Y axis direction) perpendicular to the ridge of the third convex line 144, 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” means a straight line connecting the apexes of two adjacent third ridges 144 in a cross section perpendicular to the ridge of the third ridge 144, and the two third ridges. It means a length corresponding to half 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 light flux controlling member 132 of the present embodiment, first inner top surface 133a is provided with a plurality of first ridges 142 having ridge lines substantially parallel to the Y-axis direction (see FIG. 16C), and two reflecting surfaces. A plurality of third ridges 144 having ridge lines substantially parallel to the X-axis direction are arranged on the 134 (see FIG. 16A), and a plurality of third ridges 144 having ridge lines substantially parallel to the Z-axis direction are provided on the two emission surfaces 135. Second ridges 143 are arranged (see FIG. 16D). As a result, the light emitted from the light emission center of the light emitting element 131 at a small angle with respect to the optical axis LA of the light emitting element 131 receives the first ridge 142 of the incident surface 133, the third ridge 144 of the reflecting surface 134, and Since the traveling direction of light is appropriately changed by the second ridges 143 of the emission surface 135, it is possible to prevent the light from concentrating and reaching a specific region of the light diffusion plate 150.

(Simulation 3)
Light flux controlling member C-1 (FIGS. 16A to D, FIGS. 17A and B) or C-2 (the shape of 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 diffusion plate 150 of the lighting device 100 using (FIGS. 16A, B and D, and FIGS. 8A to 8C) were analyzed.
For comparison, a light diffusion plate of a lighting device using a light flux controlling member (comparative) that is the same as light flux controlling member C-1 or C-2 except that first inner top surface 133a does not have a ridge. The illuminance distribution and chromaticity Y value above were also analyzed.

  In light flux controlling members C-1 (FIGS. 16A to D, FIGS. 17A and B) and C-2 (FIGS. 16A, B and D, and FIGS. 8A to C), parameters of two reflecting surfaces 134 and two emitting surfaces 135 are set. The parameters were set as follows. In addition, the parameters of the first inner top surface 133a and the common parameters were set similarly to the simulation 1.

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

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

The horizontal axis of FIGS. 18A and 18B represents the distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light emitting element 131. The vertical axis of FIG. 18A indicates 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 the cross-sectional shape of the reflecting surface 134 of the light flux controlling member having no third convex stripe 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 convex stripe 144. The difference Δh1 (height in the Z-axis direction; mm) obtained by subtracting the shape is shown.
a: Distance between the centers of the third ridges 144 (mm)
b: Height of the third ridge 144 (length in Z-axis direction; mm)
Center-to-center distance a of the third ridge 144: height b = 20: 1
Center-to-center distance a = 500 μm, height b = 25 μm of the third ridges 144

<Parameters of emission surface 135>
The shape of the emission surface 135 having the second ridges 143 in the cross section perpendicular to the ridgeline of the second ridges 143 was set so as to satisfy the above-mentioned formula (1). The center-to-center distances a and the heights b of the plurality of second ridges 143 in the cross section perpendicular to the ridgeline of the second ridges 143 are set as follows. The height b of the second ridge 143 was constant in the ridge direction.
Center-to-center distance a: height b = 7.5: 1 (common to AA line and BB line cross sections)
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 diffusion plate of the lighting device according to the present embodiment and the analysis result of the illuminance distribution on the light diffusion plate of the comparative lighting device. 19A, the horizontal axis represents the distance d2 (distance in the Y-axis direction; mm) from the optical axis LA of the light emitting element 131 in the light diffusion plate 150, and the vertical axis represents the maximum at each distance in the light diffusion plate 150. 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 diffusion plate of the lighting device according to the present embodiment, and the analysis result of the chromaticity Y value on the light diffusion plate of the comparative lighting device. is there. 19B, the horizontal axis represents the distance d2 (the distance in the Y-axis direction; mm) from the optical axis LA of the light emitting element 131 in the light diffusion plate 150, and the vertical axis represents the chromaticity Y value in the light diffusion plate 150. Shows.

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

  Further, as shown in FIG. 19B, in the illumination device using the light flux controlling 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 portion adjacent thereto (the arrow in FIG. 19B). However, in the illuminating device 100 using the light flux controlling member C-1 or C-2, the distance from the optical axis LA of the light emitting element 131 is different from that of the light emitting element 131. It can be seen that the difference in chromaticity between the valley bottom portion where d2 is around 40 mm and the apex portion adjacent thereto is small, and color unevenness is particularly reduced.

  From these, it is understood that the lighting device using the light flux controlling member according to the present embodiment can sufficiently suppress the color unevenness on the light emitting surface of the lighting device 100 while maintaining the high light distribution characteristics.

(effect)
As described above, light flux controlling member 132 according to the present embodiment has a plurality of first ridges 142 arranged on first inner top surface 133a and a plurality of second ridges 143 arranged on two emission surfaces 135. In addition, the plurality of third ridges 144 are arranged on the two reflecting surfaces 134. Thereby, of the light emitted from the light emitting element 131 (as compared with the case where only one of the first inner top surface 133a, the emitting surface 135, and the reflecting surface 134 has a ridge), 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 having a large contribution to color unevenness), the emission directions of other light (light having a small contribution to color unevenness) Since it is not changed more than necessary, color unevenness can be suppressed while maintaining desired light distribution characteristics.

[Modification]
In Embodiments 1 and 3, an example in which a plurality of first ridges 142 is provided only on first inner top surface 133a in light flux controlling member 132 has been described, but the present invention 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 the second and third embodiments, an example in which the plurality of second ridges 143 are respectively provided on the entire surface of the emission surface 135 is shown, but the present invention is not limited to this, and is provided only on a part of the emission surface 135. You may be asked.

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

  Further, in the first to third embodiments, in light flux controlling member 132, an example in which the inner surface shape of recess 139 is a surface including an edge is shown, but the present invention is not limited to this, and a hemispherical shape, a semi-ellipsoidal shape, or the like. Thus, it may be a curved surface that does not include an edge. 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 may be continuously formed.

  In Embodiments 1 to 3, in light flux controlling member 132, the inner surface shape of recess 139 has two second inner top surfaces other than first inner top surface 133a (inner top surface) and two inner side surfaces 133b. 133c, the example which further has two 3rd inner top surfaces 133d and two 4th inner top surfaces 133e was shown, but it is not limited to this, two 2nd inner top surfaces 133c, and 2nd 3rd inner top surfaces. 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 light flux control member 132, in the cross section that includes optical axis LA of light emitting element 131 and is parallel to the Y-axis direction, two emission surfaces 135 have optical axis LA of light emitting element 131. Although the example in which the light emitting element 131 is substantially parallel (not inclined) is shown, the 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 that includes the optical axis LA of the light emitting element 131 and is parallel to the Y-axis direction, the emission surface 135 is easy to handle when the molded product is taken out of the mold as the emission surface 135 moves away from the light emitting element 131 along the Z axis. When it is possible to have a mold structure that does not impair the light emitting element 131, the light emitting element 131 may be tilted away from the optical axis LA. As a result, the light refracted and emitted from the emission surface 135 in the upward direction (direction toward the light diffusion plate 150) is reduced, and thus it becomes easier to make the illuminance distribution and the color distribution uniform. The inclination angle of the emission surface 135 with respect to the optical axis LA of the light emitting element 131 in a cross section including the optical axis LA of the light emitting element 131 and parallel to the Y-axis direction may be, for example, 10 ° or less.

  In addition, in the first to third embodiments, the example in which the plurality of light emitting devices 130 are arranged in one row in the lighting device 100 has been described, but the present invention is not limited to this, and may be arranged in two or more rows.

  Further, in the first to third embodiments, in the lighting device 100, the plurality of substrates 120 are arranged for each light emitting device 130, and the example in which the substrates 120 are electrically connected to each other by the cable 140 has been described, but the present invention is not limited to this. However, 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.

  In Embodiments 1 to 3, in lighting device 100, housing 110 is a box-shaped body having a bottom plate, four side plates, and a top plate (at least a portion of which has an opening). Although an example is shown, the present invention is not limited to this, as long as it has at least a bottom plate, 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 modification. 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 with only the light diffusion plate 150.

  In addition, in the first to third embodiments, the example in which the lighting device 100 is the channel character signboard is shown, but the lighting device 100 is not limited to this, and may be line lighting or the like.

  The lighting device having the light flux controlling member according to the present invention can be applied to, for example, signboards (particularly channel character signboards), line lighting, general lighting, and the like.

100 Lighting Device 110 Housing 120 Substrate 130 Light Emitting Device 131 Light Emitting Element 132 Light Flux Control Member 133 Incident Surface 133a Inner Top Surface (First Inner Top Surface)
133b inner side surface 133c second inner top surface 133d third inner top surface 133e fourth inner top surface 134 reflective surface 135 exit surface 136 collar portion 137 leg portion 138 bottom surface 139 recess 140 cable 141 caulking material 142 first convex strip 143 second Ridge 144 third ridge 150 light diffusing plate CA central axis LA optical axis

Claims (11)

A light flux controlling member for controlling light distribution of light emitted from a light emitting element,
An inner surface of the concave portion arranged on the back side, an incident surface on which the light emitted from the light emitting element is incident,
Two reflecting surfaces that are arranged on the front side and that reflect a part of the light incident on the incident surface in two directions that are substantially perpendicular to the optical axis of the light emitting element and are opposite to each other,
Two emission surfaces, which are arranged to face each other with the two reflection surfaces sandwiched therebetween, and which respectively emit the light reflected by the two reflection surfaces to the outside.
Have
The incident surface has an inner top surface of the recess and two inner side surfaces sandwiching the inner top surface of the recess and arranged in a direction in which the two output surfaces face each other.
On the inner top surface, when viewed along the optical axis of the light emitting element, a plurality of first ridges having ridge lines substantially parallel to the direction in which the two emission surfaces face each other are arranged,
The height of the first ridge in a cross section perpendicular to the ridgeline of the first ridge becomes lower as it approaches the two emission surfaces.
Light flux control member. A light flux controlling member for controlling light distribution of light emitted from a light emitting element,
An inner surface of the concave portion arranged on the back side, an incident surface on which the light emitted from the light emitting element is incident,
Two reflecting surfaces that are arranged on the front side and that reflect a part of the light incident on the incident surface in two directions that are substantially perpendicular to the optical axis of the light emitting element and are opposite to each other,
Two emission surfaces, which are arranged to face each other with the two reflection surfaces sandwiched therebetween, and which respectively emit the light reflected by the two reflection surfaces to the outside.
Have
A plurality of second ridges each 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 in a direction in which the two emission surfaces face each other. Cage,
The height of the second ridge in a cross section perpendicular to the ridgeline of the second ridge becomes lower toward the back side.
Light flux control member. A plurality of second ridges each 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 in a direction in which the two emission surfaces face each other. Cage,
The height of the second ridge in a cross section perpendicular to the ridgeline of the second ridge becomes lower toward the back side.
The light flux controlling member according to claim 1. At least a part of each of the two reflecting surfaces has a plurality of third ridges each having a ridge line substantially perpendicular to a direction in which the two emitting surfaces face each other when viewed along the optical axis of the light emitting element. Is located,
The light flux controlling member according to claim 1. In the ridgeline direction of the first ridge, the inclination of the ridgeline of the first ridge is constant.
The light flux controlling member according to claim 1. In the ridgeline direction of the second ridge, the inclination of the ridgeline of the second ridge is constant.
The light flux controlling member according to claim 2. The width of the first ridge in a cross section perpendicular to the ridgeline of the first ridge becomes smaller as it approaches the emission surface,
The light flux controlling member according to claim 1. The width of the second ridge in a cross section perpendicular to the ridgeline of the second ridge becomes smaller toward the back side.
The light flux controlling member according to claim 2. A light emitting element,
The light flux controlling member according to any one of claims 1 to 8, wherein the incident surface is disposed so as to face the light emitting element.
And a light emitting device. Light emitted from the light emission center of the light emitting element at an angle of at least 0 ° and not more than 10 ° 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. A plurality of light emitting devices according to claim 9 or 10,
A light diffusing plate that transmits the light emitted from the light emitting device while diffusing it;
A lighting device.