Light-emitting device, light flux control member, and surface light source device

Abstract

The invention relates to a light-emitting device, a luminous flux control member, and a surface light source device. This light-emitting device is provided with: a light-emitting element; a light flux control member having a recessed portion through which light emitted from the light emitting element is transmitted, a first reflection surface which reflects a portion of the light transmitted through the recessed portion, and an emission surface which emits the light reflected by the first reflection surface to the outside; and a translucent resin which is filled in the recess, seals the light-emitting element, and adheres the light flux control member to the substrate and the light-emitting element, in which, when viewed in plan view, an end portion of the first reflection surface on the center axis side is positioned further inward than an outer edge of the light-emitting element, and the end portion of the second reflection surface on the center axis side is positioned further inward than the outer edge of the light-emitting element. The distance between the end portion of the first reflecting surface and the outer edge is 25% or less of the length of the short axis of the light-emitting element, and the short axis passes through the center of the light-emitting element.

Description

Technical Field

[0001] The invention relates to a light emitting device, a light beam control component and a surface light source device. Background Art

[0002] A known technique called potting is a technique for sealing components and circuits by injecting resin into components and circuits arranged on a substrate and curing the resin. In addition, a light-emitting element having a light-reflecting film on the upper surface is known. In recent years, as a light-emitting device for a high-end direct-type surface light source device, a light-emitting device in which a light-emitting element is sealed with resin is used, and the light-emitting element is arranged on a substrate and has a light-reflecting film on its upper surface. For example, Patent Document 1 discloses such a light-emitting device.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-082802 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In the light-emitting device as described above, the resin covering and sealing the light-emitting element has the function of spreading the light. Therefore, compared with the case where there is only the light-emitting element, the light from the light-emitting element sealed by the resin will be more spread. If the light is more spread, the following advantages can be enjoyed, that is, the center-to-center distance (pitch) of multiple light-emitting devices can be expanded in the surface light source device, thereby reducing the number of light-emitting devices and reducing costs.

[0008] However, during potting, resin is dripped onto the light emitting element disposed on the substrate to seal the light emitting element, so the shape of the resin cannot be made into a desired shape. Therefore, the effect of spreading light may not be sufficient.

[0009] The present invention aims to provide a light emitting device that can seal a light emitting element and spread light more widely. In addition, the present invention aims to provide a surface light source device having the light emitting device. In addition, the present invention aims to provide a light beam control component for the light emitting device.

[0010] Solutions to the problem

[0011] The present invention relates to the following light emitting device, light beam control component and surface light source device.

[0012] [1] A light emitting device comprising: a substrate; a light emitting element arranged on the substrate and having a light reflecting film on an upper surface; a light beam controlling member comprising: a recessed portion arranged on the back side so as to cover the light emitting element and for transmitting light emitted from the light emitting element; a first reflecting surface arranged on the front side and for reflecting a portion of the light transmitted through the recessed portion in a direction substantially perpendicular to and away from a central axis of the light emitting element; and an emitting surface for emitting the light reflected by the first reflecting surface and another portion of the light emitted from the light emitting element to the outside; and a light-transmitting resin filled in the recessed portion to seal the light emitting element and to bond the light beam controlling member to the substrate and the light emitting element, wherein in the light emitting device, in a perspective plan view, an end of the first reflecting surface on the central axis side is located further inward than an outer edge of the light emitting element, and a distance between the end of the first reflecting surface and the outer edge is less than 25% of a length of a minor axis of the light emitting element, the minor axis passing through the center of the light emitting element.

[0013] [2] The light-emitting device as described in [1], wherein the distance between the end of the first reflecting surface and the outer edge is less than 23% of the length of the short axis of the light-emitting element, and the short axis passes through the center of the light-emitting element.

[0014] [3] The light emitting device according to [1] or [2], wherein the area inside the inner edge formed by the end of the first reflecting surface is 60% to 80% of the area inside the outer edge of the light emitting element.

[0015] [4] A light emitting device as described in any one of [1] to [3], wherein the light beam controlling component further has a second reflecting surface, which is a plane arranged on the front side outside the first reflecting surface and substantially perpendicular to the central axis.

[0016] [5] A light-emitting device as described in [4], wherein, when the angle of the direction of light emitted from a position at half the height of the light-emitting element as the exit point and traveling perpendicularly to the substrate toward the front side of the light beam control component is set to 0°, the first angle light emitted at an angle of greater than 70° and less than 110° includes light that is emitted from the light-emitting element without being reflected by the first reflecting surface and the second reflecting surface and is emitted from the exit surface.

[0017] [6] A light-emitting device as described in [4] or [5], wherein, when the angle of the direction of light emitted from a position at half the height of the light-emitting element as the exit point and traveling perpendicularly to the substrate toward the front side of the light beam control component is set to 0°, a second angle light ray emitted at an angle greater than 60° and less than 70° and a third angle light ray emitted at an angle greater than 110° and less than 120° include light rays emitted from the light-emitting element, reflected by the second reflecting surface, and emitted from the exit surface to the substrate.

[0018] [7] The light emitting device according to any one of [1] to [6], wherein the refractive index of the light flux controlling member and the light-transmitting resin is 1.4 to 1.6 respectively.

[0019] [8] A light flux controlling component used in the light emitting device described in any one of [1] to [7].

[0020] [9] A surface light source device comprising a light diffusion plate and at least one light emitting device, wherein the light emitting device is the light emitting device described in any one of [1] to [7].

[0021]

[10] A surface light source device as described in [9], wherein the at least one light-emitting device is a plurality of light-emitting devices, and the plurality of light-emitting devices are arranged in rows at equal intervals in the X direction and in the Y direction perpendicular to the X direction, and when the center-to-center distance between two adjacent light-emitting devices in the X direction among the plurality of light-emitting devices is set to Px, the center-to-center distance between two adjacent light-emitting devices in the Y direction among the plurality of light-emitting devices is set to Py, Px is set to be less than Py, and the distance between the substrate and the light diffuser is set to H, H / Px is 0.2 to 0.3.

[0022] Effects of the Invention

[0023] According to the present invention, a light emitting device that can seal a light emitting element and spread light more can be provided. In addition, according to the present invention, a surface light source device having the light emitting device can be provided. In addition, according to the present invention, a light beam control component for the light emitting device can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1A , Figure 1B This is a diagram showing the structure of the surface light source device according to the first embodiment.

[0025] Figure 2A , Figure 2B It is a diagram showing the arrangement of light-emitting devices in a surface light source device.

[0026] Figure 3A to Figure 3E It is a diagram showing the structure of a light flux controlling member according to an embodiment.

[0027] Figure 4A , Figure 4B This is an enlarged view of the light flux controlling component according to the embodiment.

[0028] Figure 5A , Figure 5B This is a diagram showing the light distribution of light beams by the light flux controlling member according to the first embodiment.

[0029] Figure 6A to Figure 6D This is a diagram showing the light distribution of light beams by the light flux controlling member according to the first embodiment.

[0030] Figure 7 This is a diagram showing the luminance distribution of the light-emitting device according to embodiment 1.

[0031] Figure 8 It is a diagram showing the light distribution of light beams by the light flux controlling members according to the first embodiment and the first modification.

[0032] Fig. 9 It is a diagram showing the light distribution of light beams by the light flux controlling members according to the first embodiment and the first modification.

[0033] Fig.10 It is a diagram showing the luminance distribution of the light-emitting device of Embodiment 1 and Modification 1.

[0034] Fig.11 It is a diagram showing the light distribution of light beams by the light flux controlling members according to the first embodiment and the second modification.

[0035] Fig.12 It is a diagram showing the light distribution of light beams by the light flux controlling members according to the first embodiment and the second modification.

[0036] Fig.13 It is a diagram showing the luminance distribution of the light-emitting devices of Embodiment 1 and Modification Example 2.

[0037] Fig.14A , Fig. 14B It is a diagram showing the luminance distribution of the light-emitting devices of embodiment 1, variant example 3, and variant example 4.

[0038] Fig.15A , Fig. 15B This is a diagram showing the light distribution of light beams by the light flux controlling member according to the first embodiment.

[0039] Figures 16A to 16F This is a diagram showing the structure of a light flux controlling member according to the second embodiment.

[0040] Fig.17 It is a diagram showing a method for manufacturing a light-emitting device.

[0041] Fig.18It is a diagram showing a method for manufacturing a light-emitting device.

[0042] Description of Reference Numerals

[0043] 100: surface light source device;

[0044] 100': display device;

[0045] 102: display component;

[0046] 110: housing;

[0047] 112: bottom plate;

[0048] 114: Top plate;

[0049] 120: light diffusion plate;

[0050] 200: Light emitting device;

[0051] 210: substrate;

[0052] 220: light emitting element;

[0053] 221: outer edge;

[0054] 230: light-transmitting resin;

[0055] 300, 300a, 300b, 400: beam control components;

[0056] 310, 410: concave part;

[0057] 320, 420: first reflection surface;

[0058] 321: inner edge;

[0059] 330, 330a, 430: second reflecting surface;

[0060] 340, 440: exit surface;

[0061] 341: first exit surface;

[0062] 342: second exit surface;

[0063] 343: The third exit surface. DETAILED DESCRIPTION

[0064] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, as a representative example of the surface light source device of the present invention, a surface light source device suitable for a backlight source of a liquid crystal display device will be described. These surface light source devices can be combined with a display component 102 (for example, a liquid crystal panel) to be irradiated with light from the surface light source device to be used as a display device 100' (see Figure 1B ).

[0065] [Implementation Method]

[0066] (Structure of surface light source device and light emitting device)

[0067] Figure 1A , Figure 1B , Figure 2A It is a diagram showing the structure of a surface light source device 100 according to an embodiment of the present invention. Figure 1A is a top view of the surface light source device 100, Figure 1B It is the main view. Figure 2A yes Figure 1B The cross-sectional schematic diagram along the AA line is shown. Figure 2B yes Figure 1A A partial enlarged cross-sectional view of line BB is shown. Figure 2A FIG. 1 schematically shows the arrangement of the plurality of light emitting devices 200 in the surface light source device 100. Figure 2B The configuration of the light emitting device 200 as viewed in cross section is shown.

[0068] like Figure 1A to Figure 2B As shown in FIG. 1 , the surface light source device 100 of this embodiment includes a housing 110, a plurality of light emitting devices 200, and a light diffusion plate 120. Figure 2A As shown, a plurality of light emitting devices 200 are arranged on the bottom plate 112 of the housing 110. The inner surface of the bottom plate 112 functions as a diffuse reflection surface. In addition, an opening is provided on the top plate 114 of the housing 110. The light diffusion plate 120 is arranged in a manner to block the opening and functions as a light emitting surface. The size of the light emitting surface is not particularly limited, but is, for example, about 400 mm×about 700 mm.

[0069] like Figure 2A As shown in FIG. 1 , in this embodiment, the light emitting device 200 is fixed to a substrate 210 fixed at a predetermined position on the bottom plate 112 of the housing 110. In this embodiment, the substrate 210 is rod-shaped. The light emitting device 200 has a light beam control component 300 (lens) for controlling the light distribution of the light from the light emitting element 220. It should be noted that the light emitting element 220 is arranged under the light beam control component 300 and is therefore not visible. Figure 2A For illustration purposes, the light emitting element 220 is shown.

[0070] like Figure 2A As shown in FIG. 1 , in this embodiment, a plurality of light emitting devices 200 are arranged in a row at equal intervals in the X direction, and are also arranged in a row at equal intervals in the Y direction perpendicular to the X direction. Figure 2AAs shown in FIG. 1 , when the center-to-center distance between two adjacent light emitting devices 200 in the X direction is set to Px, and the center-to-center distance between two adjacent light emitting devices 200 in the Y direction is set to Py, the X direction and the Y direction are defined so that Px is less than Py. Figure 2A As shown, Px and Py are equal. It should be noted that in this specification, the distance between the centers of two light emitting devices 200 refers to the distance between the centers of the light emitting elements 220 of the two light emitting devices 200 .

[0071] Figure 2B yes Figure 2A The cross-sectional view of the light emitting device 200 is shown in FIG. Figure 2B As shown, in the light emitting device 200, a recess 310 of a light beam control component 300 (lens) is arranged above the light emitting element 220. In addition, a light-transmitting resin 230 is filled between the light emitting element 220 and the recess 310 (in the recess 310) for sealing the light emitting element 220 and bonding the light beam control component 300 to the substrate. The light emitting device 200 in the surface light source device 100 of the embodiment of the present invention can further expand the light from the light emitting element 220 by using the light beam control component 300. Therefore, the distance (pitch) between the plurality of light emitting devices 200 can be enlarged, thereby reducing the number of light emitting devices 200 and reducing costs. The structure of such a light beam control component 300 will be described in detail later.

[0072] In addition, in the surface light source device of the present embodiment, the relationship between the distance between the substrate 210 and the light diffusion plate 120 and the pitch of the light emitting devices 200 can be set as follows. That is, when the center-to-center distance between the light emitting elements 220 of two light emitting devices 200 adjacent in the X direction is set to Px, the center-to-center distance between the light emitting elements 220 of two light emitting devices 200 adjacent in the Y direction is set to Py (as described above, the X direction and the Y direction are defined in such a manner that Px is less than Py), and the distance between the substrate 210 and the light diffusion plate 120 is set to H, H / Px can be set to 0.2 to 0.3.

[0073] (Light-emitting element)

[0074] The light emitting element 220 is the light source of the surface light source device 100 and is mounted on the substrate 210. The light emitting element 220 is, for example, a light emitting diode (LED) such as a white light emitting diode. In addition, the light emitting element 220 is a light emitting element having a light reflecting film on its upper surface. As a result, there is almost no emission of light from the upper surface of the light emitting element 220, and the emission of light is mainly from the side. The light reflecting film is, for example, a DBR (Distributed Bragg Reflector) film. The size of the light emitting element 220 is not particularly limited, but preferably, it is rectangular when viewed from above, and the length of one side is 0.1 mm to 1.0 mm, more preferably 0.2 mm to 0.7 mm. In the present embodiment, the light emitting element 220 is rectangular (square) when viewed from above.

[0075] (Translucent resin)

[0076] like Figure 2B As shown, translucent resin 230 is filled between light emitting element 220 and recess 310 on the back side of light beam control component 300 (in recess 310), and is used to seal light emitting element 220 and bond light beam control component 300 to substrate 210. Translucent resin 230 is not particularly limited as long as it has the above-mentioned function. From the viewpoint of suppressing the refraction of light emitted from light emitting element 220, translucent resin 230 preferably has a refractive index close to that of the material of light beam control component 300. Specifically, preferably, the absolute value of the difference between the refractive index of light beam control component 300 and the refractive index of translucent resin 230 is less than 0.1. The refractive index of translucent resin 230 can be, for example, 1.4 to 1.6.

[0077] Examples of the light-transmitting resin 230 include epoxy resin, silicone resin, and a resin obtained by mixing epoxy resin and silicone resin.

[0078] (Beam Control Components)

[0079] Figure 3A is a perspective view of the light beam control component 300. Figure 3B It is a top view. Figure 3C This is a bottom view. Figure 3D is a side view, Figure 3E is along Figure 3B It should be noted that Figure 3C , Figure 3E , a state in which light emitting element 220 is sealed in recess 310 of light flux controlling member 300 by light-transmitting resin 230 is shown.

[0080] Light beam control component 300 is an optical component that controls the light distribution of light emitted from light emitting element 220, and is bonded to substrate 210 by light-transmitting resin 230 filled in recess 310 on the back side of light beam control component 300. Light beam control component 300 has a substantially disk-shaped outer shape, which is circular when viewed from above or from below. The refractive index of light beam control component 300 may be, for example, 1.4 to 1.6.

[0081] Light flux controlling member 300 includes concave portion 310, first reflecting surface 320, second reflecting surface 330 and emission surface 340. Each of these will be described below.

[0082] <Concave>

[0083] The concave portion 310 is aligned with the central axis CA of the light emitting element 220 (see Figure 2B ) are arranged on the back side of light beam controlling component 300 in a manner intersecting with each other. The inner surface of recess 310 is a surface through which light from light emitting element 220 is transmitted into light beam controlling component 300. Recess 310 is filled with light-transmitting resin 230 to seal light emitting element 220. In the present embodiment, recess 310 is in the shape of a disk, and appears circular when light beam controlling component 300 is viewed from above.

[0084] The recess 310 formed in the light beam controlling component 300 is a recess that can contain the light emitting element 220. The shape of the recess 310 is not limited to the shape shown in the figure, as long as the light beam controlling component 300 and the light emitting element 220 can be bonded together by the translucent resin 230 in the recess 310.

[0085] <First Reflecting Surface>

[0086] First reflective surface 320 is disposed on the front side of light beam control component 300, and reflects at least a portion of the light incident from recess 310 in a direction substantially perpendicular to and away from central axis CA of light emitting element 220. Figure 3B As shown in FIG. 1 , when light beam control component 300 is viewed from above, first reflective surface 320 is configured in a ring shape surrounding the center of light beam control component 300. Figure 3E As can be seen from the cross-sectional view of , first reflecting surface 320 is a curved surface, and a tangent line to the curved surface gradually approaches parallelism with the back surface of beam controlling component 300 as it moves from the center of beam controlling component 300 to the outside. Since first reflecting surface 320 has such a shape, light that passes through the concave portion and reaches first reflecting surface 320 is reflected in a direction away from the central axis of light emitting element 220 and is mainly emitted from exit surface 340.

[0087] Figure 4A yes Figure 3B A magnified image of Figure 4A, light emitting element 220 is shown disposed under light beam control member 300. As for the end portion on the center side of first reflecting surface 320, i.e., the inner edge, refer to Figure 4A The positional relationship between the light emitting element 220 and the light emitting element 220 will be described. The light emitting element 220 disposed under the light beam controlling member 300 is not visible, but is shown for the purpose of description. Figure 4A Indicated by dotted lines.

[0088] like Figure 4A As shown, when the first reflecting surface 320 is viewed from above, the inner edge 321 formed by the end of the first reflecting surface 320 on the central axis CA side of the light emitting element 220 is a circle. The inner edge 321 is located inside the outer edge 221 of the light emitting element 220 when viewed from above. The distance between the inner edge 321 and the outer edge 221 only needs to be less than 25% of the length of the short axis of the light emitting element 220, preferably less than 23%, and the short axis passes through the center of the light emitting element 220.

[0089] Since the inner edge of the first reflective surface 320 and the outer edge of the light emitting element 220 are in the above-described positional relationship, light emitted from the side surface of the light emitting element 220 having the reflective film on the upper surface is easily reflected by the first reflective surface 320, and the luminance distribution becomes good.

[0090] It should be noted that, preferably, in a perspective plan view, the area inside the inner edge 321 formed by the end of the first reflective surface 320 is 60% to 80% of the area inside the outer edge 221 of the light emitting element 220 .

[0091] In this embodiment, if Figure 3E As shown, the region inside inner edge 321 is a plane and is parallel to the back surface side of light flux controlling member 300. It should be noted that this region may not be a plane.

[0092] <Second Reflecting Surface>

[0093] Second reflecting surface 330 is arranged outside first reflecting surface 320 on the front side of light flux controlling component 300. Second reflecting surface 330 mainly reflects the light reaching second reflecting surface 330 toward substrate 210. Second reflecting surface 330 is a plane substantially perpendicular to central axis CA of light emitting element 220. When light flux controlling component 300 is viewed from above, second reflecting surface 330 is arranged in a ring shape.

[0094] <Exit surface>

[0095] Outgoing surface 340 is a surface disposed on the side of light flux controlling member 300 and emits the light reflected by first reflecting surface 320 and another part of the light emitted from light emitting element 220 to the outside of light flux controlling member 300. Outgoing surface 340 is substantially parallel to central axis CA of light emitting element 220.

[0096] Figure 4B yes Figure 3D A partial enlarged view of the exit surface 340 is shown in detail. Figure 4B As shown, in this embodiment, the emission surface 340 has a first emission surface 341, a second emission surface 342 and a third emission surface 343 in order from the back side to the front side.

[0097] First emission surface 341 and third emission surface 343 are perpendicular to central axis CA of light emitting element 220. Second emission surface 342 is slightly inclined so as to approach the back side of light flux controlling member 300 as it moves away from central axis CA of light emitting element 220. It should be noted that second emission surface 342 and third emission surface 343 may be roughened.

[0098] (Light distribution simulation)

[0099] Figure 5A , Figure 5B The light distribution simulation results of the light emitting device 200 according to the present embodiment are shown. Figure 5A , Figure 5B In the figure, a light emitting element (light emitting diode) 220 having a reflective film on the upper surface and a height of 0.08 mm is used, and a point at half the height, i.e., a height of 0.04 mm, is used as the light emission point, and the light distribution of the light from the emission point is shown in a cross section. It should be noted that light emitting element 220 is sealed by light-transmitting resin 230 filled in concave portion 310 of light beam control component 300. The refractive index of light beam control component 300 is set to 1.41, and the refractive index of light-transmitting resin 230 is set to 1.41.

[0100] Figure 5A In FIG. 1 , the angle of the direction from the emission point to the front side of the light beam control component 300 perpendicular to the substrate 210 is set to 0°, and the light distribution of the light emitted from the emission point at an angle of 0° to 90° is shown. Figure 5B The light distribution of light emitted from the emission point at an angle of 91° to 180° is shown.

[0101] according to Figure 5A It can be seen that the light rays with an angle of 0° to 90° are mainly reflected by the first reflection surface 320 or the second reflection surface 330 and emitted from the emission surface 340 , or are not reflected by the first reflection surface 320 but directly emitted from the emission surface 340 .

[0102] On the other hand, light rays at 91° to 180° are mainly reflected by substrate 210 and then reflected by first reflection surface 320 or second reflection surface and then emitted from emission surface 340, or are reflected by substrate 210 and then directly emitted from emission surface 340. It should be noted that in the light emitting device of the present embodiment, light-transmitting resin 230 having a small refractive index difference with light beam controlling component 300 is filled between the back surface of light beam controlling component 300 and substrate 210, so that light rays are not reflected by the back surface but are transmitted by the back surface and reflected by substrate 210.

[0103] Figure 6A to Figure 6D The following is a simulation result of light distribution when the angles of the light rays are divided more finely.

[0104] Fig. 6A The light distribution of light emitted from the emission point at an angle of 50° to 70° is shown. Figure 6B The light distribution of the light emitted from the emission point at an angle of 70° to 90° is shown. Figure 6C The light distribution of the light emitted from the emission point at an angle of 90° to 110° is shown. Fig.6D The light distribution of light emitted from the emission point at an angle of 110° to 130° is shown.

[0105] according to Fig. 6A It can be seen that the light rays with an angle of 50° to 70° are mainly reflected by the first reflection surface 320 or the second reflection surface 330 and emitted from the emission surface 340 .

[0106] according to Figure 6B It can be seen that the light rays with an angle of 70° to 90° are mainly emitted directly from the emission surface 340 without being reflected by the first reflection surface 320 .

[0107] according to Figure 6C It can be seen that the light rays with an angle of 90° to 110° are mainly reflected by the substrate 210 first, and then directly emitted from the emission surface 340 .

[0108] according to Fig.6D It can be seen that the light rays with an angle of 110° to 130° are mainly reflected by the substrate 210 first, and then reflected by the first reflection surface 320 or the second reflection surface 330 and emitted from the emission surface 340 .

[0109] Figure 7 The luminance distribution of the light-emitting device of the embodiment and the luminance distribution of the light-emitting devices of Comparative Examples 1 and 2 are shown. Figure 7 The luminance distribution of φ shows the luminance distribution of light reaching the light diffusion plate. Figure 7 The horizontal axis of the light emitting element has the intersection of the central axis and the light diffusion plate as 0mm. Figure 7 The vertical axis represents the standardized luminance. Here, in order to compare the ability of each light emitting device to spread light, the maximum value of the luminance of each light emitting device is set to 1.

[0110] The light emitting device according to the embodiment is a light emitting device that includes light flux controlling member 300 as described above and has light distribution characteristics as shown in FIGS. 5 and 6 .

[0111] On the other hand, the light emitting device of Comparative Example 1 is a light emitting device in which a light emitting element having a reflective film on the upper surface is potted, and the light emitting device of Comparative Example 2 is a light emitting device in which a light emitting element having no reflective film on the upper surface is potted.

[0112] according to Figure 7 It can be seen that in the light emitting device of the embodiment, light spreads further than in Comparative Examples 1 and 2.

[0113] according to Figure 6A to Figure 6D and Figure 7 From the viewpoint of expanding the light, the light distribution of the light beam by the light beam controlling component of the light emitting device is preferably the following light distribution.

[0114] That is, the angle of the direction of the light emitted from the position of half the height of the light emitting element 220 as the emission point and traveling perpendicularly to the substrate 210 toward the front side of the light beam control component 300 is set to 0°, and the light emitted at an angle of 70° or more and 110° or less is taken as the first angle light. At this time, preferably, the first angle light includes the light emitted from the light emitting element 220 without being reflected by the first reflection surface 320 and the second reflection surface 330 and emitted from the emission surface 340 (refer to Figure 6B , Figure 6C ).

[0115] The proportion of the light at the first angle that is emitted from the light emitting element 220 without being reflected by the first reflecting surface 320 and the second reflecting surface 330 and emitted from the emission surface 340 can be appropriately adjusted according to the desired light distribution characteristics. For example, more than 80%, more than 85%, more than 90%, or more than 95% of the light at the first angle can be emitted from the emission surface 340 without being reflected by the first reflecting surface 320 and the second reflecting surface 330. The upper limit of this value can be, for example, less than 100%, less than 95%, or less than 90%.

[0116] In addition, similarly, the angle of the direction of the light emitted from the position of half the height of the light emitting element 220 as the exit point when it travels perpendicularly to the substrate toward the front side of the light beam control component 300 is set to 0°, and the light emitted at an angle of more than 60° and less than 70° is used as the second angle light, and the light emitted at an angle of more than 110° and less than 120° is used as the third angle light. At this time, preferably, the second angle light and the third angle light include the light emitted from the light emitting element 220, reflected by the second reflection surface 330, and emitted from the exit surface 340 toward the substrate 210 (refer to Fig. 6A , Fig.6D ).

[0117] The proportion of the second angle light rays emitted from the light emitting element 220, reflected by the second reflection surface 330, and emitted from the emission surface 340 to the substrate 210 can be appropriately adjusted according to the desired light distribution characteristics. For example, more than 80%, more than 85%, more than 90%, or more than 95% of the second angle light rays emitted from the light emitting element 220, reflected by the second reflection surface 330, and emitted from the emission surface 340 to the substrate 210 can be sufficient. The upper limit of this value can be, for example, less than 100%, less than 95%, or less than 90%.

[0118] The proportion of the third angle light emitted from the light emitting element 220, reflected by the second reflection surface 330, and emitted from the emission surface 340 to the substrate 210 can be appropriately adjusted according to the desired light distribution characteristics. For example, more than 80%, more than 85%, more than 90%, or more than 95% of the third angle light emitted from the light emitting element 220, reflected by the second reflection surface 330, and emitted from the emission surface 340 to the substrate 210 can be sufficient. The upper limit of this value can be, for example, less than 100%, less than 95%, or less than 90%.

[0119] (Effect)

[0120] According to the light flux controlling member of the embodiment of the present invention, the recess of the light flux controlling member covers the light emitting element, and the light transmissive resin filled in the recess seals the light emitting element. Thus, the light flux controlling member can further expand the light while sealing the light emitting element.

[0121] [Modification 1]

[0122] Next, a light emitting device according to variation 1 is described.

[0123] Figure 8 , Fig. 9 Comparison between the light distribution of light flux controlling member 300 included in light emitting device 200 according to the embodiment and the light distribution of light flux controlling member 300 a included in the light emitting device according to Modification 1 is shown.

[0124] exist Figure 8 , Fig. 9 As shown by the dotted line on the left, the positions of light emitting element 220 are aligned in the embodiment and variant 1. Also, as shown by the dotted line on the right, second reflecting surface 330a of light beam control component 300a of the variant is 0.4 mm smaller in the radial direction than second reflecting surface 320 of light beam control component 300 of the embodiment. Figure 8 , Fig. 9 In the embodiment, the light distribution in the light emitting device of such modification example 1 is compared with the light distribution in the light emitting device of the embodiment.

[0125] Specifically, Figure 8 The upper figure shows the light distribution of light at 60° to 80° in the light emitting device of the embodiment, and the lower figure shows the light distribution of light at 60° to 80° in the light emitting device of modification example 1.

[0126] Likewise, Fig. 9 The upper figure shows the light distribution of light at 100° to 120° in the light emitting device of the embodiment, and the lower figure shows the light distribution of light at 100° to 120° in the light emitting device of modification example 1.

[0127] according to Figure 8 , Fig. 9 It can be seen that in light flux controlling member 300a included in the light emitting device of Modification 1, second reflecting surface 330a is relatively short, and therefore less light is reflected by second reflecting surface 330a and directed toward the substrate side.

[0128] Fig.10 The luminance distribution of the light-emitting device according to the embodiment and the light-emitting device according to Modification 1 are shown. Fig.10 Zhongyu Figure 7 Similarly, the maximum value of the brightness is set to 1 to make it easier to compare the spread of light between the two. Fig.10 It can be seen that the luminance distribution of the light-emitting device of the embodiment and the light-emitting device of the modified example is almost the same, but in the light-emitting device of the modified example, a higher luminance is generated near 8 mm compared with the light-emitting device of the embodiment. This corresponds to the following situation: Figure 8 , Fig. 9 As shown, in the light emitting device of the modified example, light emitted at a specific angle is not reflected by the second reflecting surface 330a, but reaches the light diffusion plate.

[0129] (Effect)

[0130] The light emitting device of Modification 1 has the same effects as those of the light emitting device of the embodiment.

[0131] [Modification 2]

[0132] Next, a light emitting device according to variation 2 is described.

[0133] Fig.11 , Fig.12 Comparison between the light distribution of light flux controlling member 300 included in light emitting device 200 according to the embodiment and the light distribution of light flux controlling member 300 b included in the light emitting device according to Modification 2 is shown.

[0134] exist Fig.11 , Fig.12As shown by the dotted line on the left, the positions of light emitting element 220 are aligned in the embodiment and Modification 2. In addition, as shown by the dotted line on the right, the positions of the outer edges of second reflecting surface 330a are also aligned. However, in light beam controlling component 300b of Modification 2, the height of light beam controlling component (second reflecting surface 330) is lower than that of light beam controlling component 300 of the embodiment.

[0135] exist Fig.11 , Fig.12 In FIG. 1 , the light distribution in the light emitting device of such variation 2 is compared with the light distribution in the embodiment.

[0136] Specifically, Fig.11 The upper figure shows the light distribution of 60° to 80° in the light emitting device of the embodiment, and the lower figure shows the light distribution of 60° to 80° in the light emitting device of modification example 2.

[0137] Likewise, Fig.12 The upper figure shows the light distribution of light at 100° to 120° in the light emitting device of the embodiment, and the lower figure shows the light distribution of light at 100° to 120° in the light emitting device of modification example 2.

[0138] according to Fig.11 , Fig.12 It can be seen that in the light beam control component 300b of the light emitting device of Modification 2, the second reflection surface 320b is located at a lower position, so that more light reaches the second reflection surface 320b and is reflected toward the substrate side than in the embodiment. The light toward the substrate is reflected and illuminates the light diffuser at a position close to the light emitting element 220.

[0139] Fig.13 The luminance distribution of the light emitting device of the embodiment and the light emitting device of the second modification is shown. Fig.13 It can be seen that in the light-emitting device of the embodiment and the light-emitting device of the modification example 2, the brightness near the top of the light-emitting element in the light-emitting device of the modification example 2 is higher. This corresponds to the following situation: Fig.11 , 12 As shown, in Modification 2, the light reflected by the second reflection surface 320 b and directed toward the substrate is reflected by the substrate and illuminates the light diffusion plate at a position close to the light emitting element 220 .

[0140] (Effect)

[0141] The light-emitting device of Modification 2 has the same effects as those of the light-emitting device of the embodiment.

[0142] [Variation 3, 4]

[0143] Next, light emitting devices according to Modifications 3 and 4 are described.

[0144] Fig.14A and Fig. 14B The luminance distribution of the light emitting devices according to the embodiment and Modifications 3 and 4 is shown.

[0145] The light beam control component of the light emitting device of the modification example 3 is a light beam control component obtained by reducing the light beam control component 300 of the light emitting device of the embodiment. Here, the light beam control component 300 is reduced in such a way that the ratio of the length and height in the radial direction of the light beam control component 300 remains unchanged. Therefore, the shape of the light beam control component 300 is similar to the shape of the light beam control component of the modification example 3. Here, when the size of the light beam control component 300 is set to 100%, it is reduced to 90%.

[0146] On the other hand, the light beam controlling member of the light emitting device of Modification 4 is a light beam controlling member that is enlarged to 116% when the size of light beam controlling member 300 is set to 100%. It should be noted that the light beam controlling member 300 is enlarged so that the shape is similar to the shape of the light beam controlling member of Modification 4.

[0147] Fig.14A The luminance distribution of the embodiment, the modification 3, and the comparative example is shown. Fig. 14B Yes Fig.14A The maximum value of the brightness shown is set to 1. Fig. 14B In variant example 4, the light expands laterally, so it is not preferred.

[0148] (Effect)

[0149] The light emitting devices of Modifications 3 and 4 have the same effects as the light emitting device of the embodiment.

[0150] <Refractive Index>

[0151] Fig.15A , Fig. 15B The light distributions are shown when the refractive index of the material of light flux controlling member 300 constituting the light emitting device of the embodiment is set to 1.41 and 1.51. Fig.15A , Fig. 15B As shown in FIG. 1 , even if the refractive index of the material constituting light flux controlling member 300 changes, the light distribution does not change much. This is because light emitting element 220 is sealed by light-transmitting resin 230 filled in the concave portion of light flux controlling member 300, and therefore, the light emitted from light emitting element 220 does not travel in the air before entering the interior of light flux controlling member 300 from the concave portion of the light flux controlling member. Thus, the refraction of the light is suppressed, and therefore, even if the refractive index of the material constituting light flux controlling member 300 changes, the light distribution does not change much.

[0152] [Implementation Method 2]

[0153] Fig.16A is a top view of light flux controlling component 400 according to Embodiment 2. Fig. 16B This is a bottom view. Fig. 16C is along Fig.16A The cross-sectional view of the CC line, Fig.16D is along Fig.16A In addition, Fig.16E , Fig.16F is a side view of light beam control component 400. Fig. 16B , Fig. 16C , Fig.16D , a state in which light emitting element 220 is sealed by light-transmitting resin 230 in recess 410 of light flux controlling member 400 is shown.

[0154] like Fig.16A As shown, the main difference between light beam control component 400 of embodiment 2 and light beam control component 300 of embodiment 1 is that the top view shape is an ellipse. Similar to light beam control component 300, light beam control component 400 has concave portion 410, first reflection surface 420, second reflection surface 430 and emission surface 440. Each of them will be described below.

[0155] <Concave>

[0156] Concave portion 410 is arranged on the back side of light beam controlling component 400 so as to intersect the central axis of light emitting element 220. The inner surface of concave portion 410 is a surface through which light from the light emitting element is transmitted into light beam controlling component 400. Concave portion 410 is filled with light-transmitting resin 230 to seal light emitting element 220. In the present embodiment, the shape of concave portion 410 is hemispherical, and appears circular when light beam controlling component 400 is viewed from above.

[0157] Recess 410 formed in beam controlling component 400 is a recess 410 capable of containing light emitting element 220 , and the shape of recess 410 is not limited to the shape shown in the figure, as long as beam controlling component 400 and light emitting element 220 can be bonded together by translucent resin 230 in recess 410 .

[0158] <First Reflecting Surface>

[0159] First reflective surface 420 is disposed on the front side of light beam control component 400, and reflects at least a portion of the light incident through recess 410 in a direction substantially perpendicular to the central axis of light emitting element 220 and away from the central axis. Fig.16A As shown in FIG. 4 , when looking down at light beam control component 400 , first reflective surface 420 is configured in a ring shape, surrounding the center of light beam control component 300 , and its inner and outer edges are elliptical. Fig. 16C , Fig.16DAs can be seen from the cross-sectional view of , first reflecting surface 420 is a curved surface having a shape in which a tangent line to the curved surface gradually approaches a shape parallel to the back surface of light beam controlling component 400 as it moves from the center of light beam controlling component 400 to the outside. Since first reflecting surface 420 has such a shape, light that passes through the concave portion and reaches first reflecting surface 420 is reflected in a direction away from the central axis of light emitting element 220.

[0160] <Second Reflecting Surface>

[0161] Second reflecting surface 430 is arranged outside first reflecting surface 420 on the front side of light beam controlling component 400. Second reflecting surface 430 is a plane substantially perpendicular to the central axis of light emitting element 220. When light beam controlling component 400 is viewed from above, second reflecting surface 430 is arranged in a ring shape, surrounding first reflecting surface 420, and its inner and outer edges are elliptical.

[0162] <Exit surface>

[0163] Outgoing surface 440 is disposed on the side of light flux controlling member 400 and emits the light reflected by first reflecting surface 420 and another part of the light emitted from light emitting element 220 to the outside of light flux controlling member 300. Outgoing surface 440 is substantially parallel to the central axis of light emitting element 220.

[0164] (Effect)

[0165] According to Embodiment 2, a light emitting device capable of further spreading light while sealing a light source can be provided.

[0166] [Manufacturing method]

[0167] The method for manufacturing the light emitting device is described below by taking the case where the light beam control component 300 is used as an example. The method for manufacturing the light emitting device includes the following steps: Fig.17 As shown in the above figure, there is a process of preparing a substrate 210 on which a light emitting element 220 is configured; and a process of filling a translucent resin 230 in a recess 310 of a light beam control component 300, and bonding the light beam control component to the substrate 210 while sealing the light emitting element 220.

[0168] In addition, as another manufacturing method, Fig.18 As shown, there can be cited a method including the following steps: a step of dripping a translucent resin 230 onto a light emitting element 220 mounted on a substrate 210; a step of aligning a recess 310 of a light beam control component 300 on the translucent resin 230 and configuring the light beam control component 300 on the substrate 210; and a step of mounting the light beam control component 300 on the substrate 210 by curing the translucent resin 230, for example, by using heat.

[0169] These manufacturing methods can also be applied to other embodiments. In order to avoid bubbles remaining in the recess of the light beam control component, it is preferred to make appropriate adjustments and design changes to the amount of translucent resin used, the shape of the recess, etc., so that no bubbles that affect the light beam control function remain.

[0170] Industrial Applicability

[0171] The light emitting device, light flux controlling member, and surface light source device of the present invention can be applied to, for example, a backlight source of a liquid crystal display device and general lighting.

Claims

1. A light emitting device, characterized in that: have: substrate; a light emitting element disposed on the substrate and having a light reflecting film on an upper surface; a light beam control member having: a recessed portion arranged on the back side so as to cover the light emitting element and through which light emitted from the light emitting element passes; a first reflecting surface disposed on the front side, for reflecting a portion of the light transmitted through the concave portion in a direction substantially perpendicular to and away from the central axis of the light emitting element; and an emitting surface for emitting the light reflected by the first reflecting surface and another portion of the light emitted from the light emitting element to the outside respectively; as well as A light-transmitting resin is filled in the concave portion to seal the light-emitting element, and the light beam control component is bonded to the substrate and the light-emitting element. In the light-emitting device, when viewed from above, the end of the first reflecting surface on the central axis side is located closer to the inside than the outer edge of the light-emitting element, and the distance between the end of the first reflecting surface and the outer edge is less than 25% of the length of the short axis of the light-emitting element, and the short axis passes through the center of the light-emitting element.

2. The light emitting device according to claim 1, wherein: A distance between an end of the first reflecting surface and the outer edge is less than 23% of a length of a short axis of the light emitting element, and the short axis passes through a center of the light emitting element.

3. The light emitting device according to claim 1, wherein: An area inside an inner edge formed by an end portion of the first reflecting surface is 60% to 80% of an area inside an outer edge of the light emitting element.

4. The light emitting device according to claim 1, wherein: The light flux controlling member further includes a second reflecting surface which is a plane arranged outside the first reflecting surface on the front side and is substantially perpendicular to the central axis.

5. The light emitting device according to claim 4, wherein: When the angle of the direction of the light emitted from the position at half the height of the light emitting element as the emission point and traveling perpendicularly to the substrate toward the front side of the light flux controlling member is set to 0°, The first angle light emitted at an angle of 70° or more and 110° or less includes light emitted from the light emitting element without being reflected by the first reflecting surface and the second reflecting surface and then emitted from the emission surface.

6. The light emitting device according to claim 4, wherein: When the angle of the direction of the light emitted from the position at half the height of the light emitting element as the emission point and traveling perpendicularly to the substrate toward the front side of the light flux controlling member is set to 0°, The second angle light emitted at an angle of greater than 60° and less than 70° and the third angle light emitted at an angle greater than 110° and less than 120° include the light emitted from the light emitting element, reflected by the second reflection surface and emitted from the emission surface to the substrate.

7. The light emitting device according to claim 1, wherein: The light flux controlling member and the light-transmitting resin each have a refractive index of 1.4 to 1.

6.

8. A beam control component, characterized in that: Used in the light emitting device according to any one of claims 1 to 7.

9. A surface light source device, characterized in that: A light diffuser and at least one light emitting device are provided, wherein the light emitting device is the light emitting device according to any one of claims 1 to 7.

10. The surface light source device according to claim 9, wherein: The at least one light emitting device is a plurality of light emitting devices, The plurality of light emitting devices are arranged in a row at equal intervals in an X direction and in a Y direction perpendicular to the X direction. When the center-to-center distance between two adjacent light-emitting devices in the X direction among the plurality of light-emitting devices is set to Px, the center-to-center distance between two adjacent light-emitting devices in the Y direction among the plurality of light-emitting devices is set to Py, Px is set to be less than Py, and the distance between the substrate and the light diffusion plate is set to H, H / Px is 0.2~0.3.

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