Light-emitting device and lighting device using same

Abstract

[Problem] To provide a light-emitting device capable of efficiently enhancing irradiation in a specific direction. [Solution] A light-emitting device (1) is provided with: a substrate (10); a pair of power supply terminals (21) and (22) provided on the substrate; a plurality of first light-emitting elements (31) and a plurality of second light-emitting elements (32) that emit light by supplying power between the pair of power supply terminals; and a light emitting surface (40) that emits light emitted by the light emitting elements, the light emitting surface having a first light emitting region (41), which is a surface region that includes a center of gravity of the light emitting surface in plan view, and second light emitting regions (42, 43), which are surface regions that do not include the first light emitting region, the light emitting element group (60) constituting the plurality of light emitting elements comprising: a first light emitting element group (61); the first light-emitting element is composed of a plurality of first light-emitting elements arranged in a first light-emitting area in a plan view. And a second light-emitting element group (62) comprising a plurality of second light-emitting elements disposed in the second light emission region in plan view. The average brightness of the light emitted from the first light emitting region is higher than the average brightness of the light emitted from the second light emitting region.

Description

Technical Field

[0001] The present invention relates to a light-emitting device in which a plurality of light-emitting elements are arranged, and a lighting device using the light-emitting device. Background Art

[0002] A light-emitting device is known that utilizes multiple LED (Light-Emitting-Diode) elements within a narrow light-emitting area to generate light. For example, Patent Document 1 describes a light-emitting device in which multiple LED elements are grouped into a predetermined number and connected in a mixed series and parallel configuration. The light-emitting device described in Patent Document 1 prevents excessively high drive voltages and minimizes variations in light emission among individual LED elements. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-9298 Summary of the Invention Problems to be solved by the invention

[0004] However, in the light-emitting device described in Patent Document 1, the number of LED elements in parallel in each group is the same, and the current of equal value flows through each LED element, so the amount of light emitted by each LED element is also equal. Therefore, the lighting device using the light-emitting device described in Patent Document 1 has difficulty in enhancing illumination in a specific direction.

[0005] Therefore, an object of the present invention is to provide a light-emitting device and a lighting device using the same, wherein the light-emitting device is provided with an area with high average brightness and an area with low average brightness on a light emitting surface, and can efficiently enhance illumination in a specific direction. Technical means to solve the problem

[0006] The light-emitting device of the present invention comprises: a pair of power terminals, which are arranged on the substrate; a plurality of first light-emitting elements and a plurality of second light-emitting elements, which emit light by supplying power between the pair of power terminals; and a light emitting surface, which emits light emitted by the plurality of first light-emitting elements and the plurality of second light-emitting elements, the light emitting surface having a surface area including the center of gravity of the light emitting surface when viewed from above, namely a first light emitting area, and a surface area not including the first light emitting area, namely a second light emitting area, the plurality of first light-emitting elements are arranged in the first light emitting area when viewed from above, forming a first light-emitting element group, and the plurality of second light-emitting elements are arranged in the second light emitting area when viewed from above, forming a second light-emitting element group, and the average brightness of the light emitted from the first light emitting area is higher than the average brightness of the light emitted from the second light emitting area.

[0007] In addition, in the light-emitting device of the present invention, the first light-emitting element group includes at least one first light-emitting element column in which the plurality of first light-emitting elements are arranged, the gaps between the plurality of first light-emitting elements constituting the first light-emitting element column are smaller than the element size of the first light-emitting elements, and the plurality of first light-emitting elements are connected in series. On the other hand, the second light-emitting element group includes a plurality of second light-emitting element columns in which the plurality of second light-emitting elements are arranged, the gaps between the plurality of second light-emitting elements constituting the second light-emitting element column are smaller than the element size of the second light-emitting elements, and the plurality of second light-emitting elements are connected in series.

[0008] Furthermore, the lighting device of the present invention includes the above-mentioned light-emitting device and a condenser arranged above the light-emitting surface. Effects of the Invention

[0009] According to the light-emitting device of the present invention, since the average brightness of light emitted from the first light-emitting area including the center of gravity of the light-emitting surface is higher than the average brightness of light emitted from the second light-emitting area not including the first light-emitting area, the illumination from the light-emitting device in a specific direction can be efficiently enhanced.

[0010] Furthermore, according to the light-emitting device of the present invention, since the gaps between the plurality of first light-emitting elements constituting the first light-emitting element column are set to be smaller than the element size of the first light-emitting elements, and the gaps between the plurality of second light-emitting elements constituting the second light-emitting element column are set to be smaller than the element size of the second light-emitting elements, the occurrence of color unevenness in light emitted from the light-emitting device can be suppressed.

[0011] Furthermore, according to the lighting device of the present invention, since the light-emitting device of the present invention is used, it is possible to effectively enhance the lighting directed in a specific direction while suppressing the occurrence of color unevenness.

[0012] Furthermore, the lighting device of the present invention utilizes the light-emitting device of the present invention, thereby enhancing emission in specific directions and reducing emission in directions other than the specific directions. This allows for illumination that minimizes light pollution. Furthermore, by reducing the amount of electricity supplied, it can contribute to the United Nations Sustainable Development Goals (SDGs). BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1A It is a perspective view of a light emitting device according to a first embodiment of the present invention. Figure 1B It is a top view of the light emitting device according to the first embodiment of the present invention. Figure 2 It is magnified Figure 1AA top view of the area surrounded by the dotted line A. Figure 3 This is a circuit diagram of a light-emitting device according to a first embodiment of the present invention. Figure 4A This diagram shows the front chromaticity due to differences in column ratios at a color temperature of 2700K. Figure 4B This diagram shows the front chromaticity due to differences in column ratios at a color temperature of 5000K. Figure 5 FIG2 schematically shows the color unevenness of light emitted from the concentrator of the light emitting device. Figure 6 1 and 2 show examples of element size ratios that vary depending on element arrangement. Figure 7 This is a graph showing the area ratio of color unevenness in a light-emitting device relative to the element size ratio. Figure 8 It is a plan view of a light emitting device according to a second embodiment of the present invention. Figure 9 It is a plan view of a light emitting device according to a third embodiment of the present invention. Figure 10 It is a top view of a light emitting device according to a fourth embodiment of the present invention. Figure 11 It is a plan view of a light emitting device according to a fifth embodiment of the present invention. Figure 12 This is a circuit diagram of a light-emitting device according to a fifth embodiment of the present invention. Figure 13 This is a circuit diagram of a light-emitting device according to a sixth embodiment of the present invention. Figure 14A This is a characteristic diagram (part 1) showing luminous intensity distribution of a lighting device using the light-emitting device according to the first embodiment of the present invention and a lighting device using the light-emitting device of a comparative example. Figure 14B This is a characteristic diagram (part 2) showing luminous intensity distribution of a lighting device using the light-emitting device according to the first embodiment of the present invention and a lighting device using the light-emitting device of a comparative example. Figure 14C This is a characteristic diagram (part 3) showing the luminous intensity distribution of a lighting device using the light-emitting device according to the first embodiment of the present invention and a lighting device using the light-emitting device of a comparative example. Figure 15A This is a front view of a lighting device using the light-emitting device according to the first embodiment of the present invention. Figure 15B This is a plan view of a lighting device using the light-emitting device according to the first embodiment of the present invention. Figure 16This is a cross-sectional view of a condenser lens disposed above the light-emitting device. Figure 17A is a top view of a light-emitting device of a comparative example. Figure 17B is a circuit diagram of a light-emitting device of a comparative example. Figure 18 It is a perspective view of a light emitting device having multiple light emitting surfaces. DETAILED DESCRIPTION

[0014] Hereinafter, the light emitting device and the lighting device of the present invention will be described with reference to the accompanying drawings. However, it should be noted that the scope of the present invention is not limited to these embodiments but covers the inventions described in the claims and their equivalents.

[0015] Figure 1A is a perspective view of a light emitting device 1 according to a first embodiment of the present invention. Figure 1B is a top view of the light emitting device 1. Figure 1B The bonding wires 14 and Figure 1A Sealing material 12 is shown. Figure 2 It is magnified by Figure 1A The top view of the range surrounded by the dotted line A is shown. Figure 2 In, omitted Figure 1A The reflecting frame 11 and the sealing material 12 shown, Figure 1B A first power supply wiring 91 and a second power supply wiring 92 are shown. Figure 3 This is a circuit diagram of the light emitting device according to the first embodiment.

[0016] The light-emitting device 1 of the first embodiment includes a substrate 10, a first power terminal 21 and a second power terminal 22 serving as a pair of power terminals, a plurality of first light-emitting elements 31 and a plurality of second light-emitting elements 32 constituting a light-emitting element group 60, a reflective frame 11, and a sealing material 12. LED elements are used as the first light-emitting elements 31 and the second light-emitting elements 32.

[0017] The substrate 10 is a laminated substrate in which the lower surface of a circuit substrate formed of an insulating material such as glass epoxy resin is bonded to the upper surface of a mounting substrate made of a metal with high thermal conductivity, such as aluminum. The upper surface of the substrate 10 has a mounting area 50, to which a plurality of first light-emitting elements 31 and a plurality of second light-emitting elements 32 constituting the light-emitting element group 60 are mounted via an insulating adhesive or the like. The circuit substrate may also have a planar shape having substantially the same outer shape as the mounting substrate, forming an opening surrounding the mounting area 50. A highly reflective film may also be provided on the upper surface of the mounting substrate. The substrate 10 may also be a ceramic substrate with high thermal conductivity. The planar shape of the substrate 10 may be polygonal or elliptical. In this embodiment, the substrate 10 has a square planar shape with a side of 20 mm.

[0018] On the top surface of the substrate 10, a pair of first and second power terminals 21, 22 are arranged at diagonal corners. The first and second power terminals 21, 22 are wiring patterns formed from a conductive thin film such as copper. They are used to supply power from an external power source (not shown) to the plurality of first and second light-emitting elements 31, 32 mounted on the mounting area 50. The first and second power terminals 21, 22 may also be solder-plated or gold-plated. Electronic components such as connectors may also be mounted on the first and second power terminals 21, 22. The first and second power terminals 21, 22 may be arranged on either the side or bottom surface of the substrate 10.

[0019] The light emitting element group 60 is composed of a first light emitting element group 61 and a pair of second light emitting element groups 62 and 63 arranged on both sides of the first light emitting element group 61 .

[0020] The first light-emitting element group 61 is composed of a plurality of first light-emitting element columns 71. Furthermore, the first light-emitting element columns 71 are composed of a plurality of first light-emitting elements 31. The plurality of first light-emitting elements 31 constituting the first light-emitting element columns 71 are connected in series via bonding wires 14. The plurality of first light-emitting element columns 71 constituting the first light-emitting element group 61 are connected in parallel via bonding wires 14 between first power supply pads 81 and opposing electrode pads 84, which are arranged to sandwich the first light-emitting element columns 71 and are located on both sides of the first light-emitting element columns 71. In this embodiment, the first light-emitting element group 61 is composed of four first light-emitting element columns 71, each of which is composed of eight first light-emitting elements 31.

[0021] The second light-emitting element group 62, arranged on one side of the first light-emitting element group 61, is composed of a plurality of second light-emitting element columns 72. Furthermore, the second light-emitting element columns 72 are composed of a plurality of second light-emitting elements 32. The plurality of second light-emitting elements 32 constituting the second light-emitting element columns 72 are connected in series via bonding wires 14. The plurality of second light-emitting element columns 72 constituting the second light-emitting element group 62 are connected in parallel via bonding wires 14 between the opposing electrode pads 84 and the second power supply pads 82, which are arranged to sandwich the second light-emitting element columns 72 and are located on both sides of the second light-emitting element columns 72. In this embodiment, the second light-emitting element group 62 is composed of three second light-emitting element columns 72, each of which is composed of eight second light-emitting elements 32.

[0022] On the other hand, the second light-emitting element group 63, arranged on the other side of the first light-emitting element group 61, is composed of a plurality of second light-emitting element columns 73. Furthermore, the second light-emitting element columns 73 are composed of a plurality of second light-emitting elements 32. The plurality of second light-emitting elements 32 constituting the second light-emitting element columns 73 are connected in series via bonding wires 14. The plurality of second light-emitting element columns 73 constituting the second light-emitting element group 63 are connected in parallel via bonding wires 14 between the opposing electrode pads 84 and the third power supply pads 83, which are arranged to sandwich the second light-emitting element columns 73 and are located on both sides of the second light-emitting element columns 73. In this embodiment, the second light-emitting element group 63 is composed of three second light-emitting element columns 73, each of which is composed of eight second light-emitting elements 32. Furthermore, the light-emitting elements constituting the second light-emitting element columns 73 arranged on the other side are composed of the same second light-emitting elements 32 as those constituting the second light-emitting element columns 72 arranged on one side. Furthermore, the number of the second light emitting elements 32 constituting the second light emitting element column 73 is the same as the number of the second light emitting elements 32 constituting the second light emitting element column 72 .

[0023] The number of columns of the first light emitting element columns 71 constituting the first light emitting element group 61 is less than the sum of the numbers of columns of the second light emitting element columns 72 and 73 constituting the pair of second light emitting element groups 62 and 63. In the present embodiment, the number of columns of the first light emitting element columns 71 constituting the first light emitting element group 61 is two columns less than the sum of the numbers of columns of the second light emitting element columns 72 and 73 constituting the second light emitting element groups 62 and 63.

[0024] The first light-emitting element 31 is a blue LED die having a rectangular planar shape, including an anode electrode and a cathode electrode. It emits blue light depending on the forward voltage applied between the anode and cathode electrodes. The dominant wavelength of the blue light emitted from the first light-emitting element 31 is between 445 nm and 495 nm. The first light-emitting element 31 is formed by stacking a PN junction layer formed of a gallium nitride layer on a sapphire substrate, which serves as a transparent substrate. In this embodiment, the first light-emitting element 31 has a square planar shape with a side of 0.7 mm, and the dominant wavelength of the blue light emitted from the first light-emitting element 31 is 450 nm.

[0025] The second light-emitting element 32 is a blue LED die having a rectangular planar shape, which has an anode electrode and a cathode electrode, and emits blue light according to the forward voltage applied between the anode electrode and the cathode electrode. The main wavelength of the blue light emitted from the second light-emitting element 32 is in the range between 445nm and 495nm. The second light-emitting element 32 is formed by stacking a PN junction layer formed by a gallium nitride layer on a sapphire substrate as a transparent substrate. The second light-emitting element 32 can also be a light-emitting element having the same characteristics as the first light-emitting element 31. In addition, the second light-emitting element 32 can also be a light-emitting element having a smaller element size than the first light-emitting element 31. In this embodiment, the second light-emitting element 32 is a light-emitting element having the same characteristics as the first light-emitting element 31.

[0026] The mounting area 50 is an area on the upper surface of the substrate 10 where a plurality of first light-emitting elements 31 and a plurality of second light-emitting elements 32 constituting the light-emitting element group 60 are mounted, and includes a first mounting area 51 and a pair of second mounting areas 52, 53 arranged on both sides of the first mounting area 51. The first mounting area 51 and the second mounting areas 52, 53 are arranged adjacent to each other in a stripe shape. Furthermore, the first mounting area 51 is located in the surface area including the center of gravity of the light emitting surface 40, that is, the central part of the mounting area 50 and is arranged between the left and right pair of second mounting areas 52, 53. In addition, the second mounting areas 52, 53 are arranged to be isolated from each other, sandwiching the first mounting area 51. The planar shape of the mounting area 50 is preferably rectangular. The boundary lines L12, L13 indicating the boundaries of the first mounting area 51 and the second mounting areas 52, 53 are preferably aligned with the first mounting area 51 and the second mounting areas 52, 53. Figure 2 In this embodiment, the plane shape of the mounting area 50 is a rectangle, and the boundary line L12 and the boundary line L13 are straight lines parallel to the second direction.

[0027] A plurality of first light emitting elements 31 constituting a first light emitting element group 61 are mounted on the first mounting area 51. No light emitting elements constituting a light emitting element group other than the first light emitting element group 61 are mounted on the first mounting area 51. The planar shape of the first mounting area 51 is preferably a minimum rectangle that includes all of the plurality of first light emitting elements 31 mounted on the first mounting area 51. The first light emitting elements 31 mounted on the first mounting area 51 may be arranged in a rectangular shape. Figure 2 The first light-emitting elements 31 are arranged at equal intervals parallel to the first direction shown, and can also be arranged at equal intervals parallel to the second direction. In this embodiment, the first light-emitting elements 31 mounted on the first mounting area 51 are arranged at intervals of 1.0 mm parallel to the first direction and at intervals of 1.0 mm parallel to the second direction. In this case, the gap between adjacent first light-emitting elements 31 is 0.3 mm, which is smaller than the respective longitudinal and transverse dimensions of each first light-emitting element 31. In addition, the longitudinal and transverse dimensions of an element are also referred to as element dimensions.

[0028] A plurality of second light-emitting elements 32 constituting second light-emitting element groups 62 and 63 are mounted on the second mounting areas 52 and 53. Light-emitting elements constituting light-emitting element groups other than the second light-emitting element groups 62 and 63 are not mounted on the second mounting areas 52 and 53. The planar shape of the second mounting areas 52 and 53 is preferably a minimum rectangle that encompasses all of the plurality of second light-emitting elements 32 mounted on the second mounting areas 52 and 53. The second light-emitting elements 32 mounted on the second mounting areas 52 and 53 can be arranged at equal intervals parallel to the first direction, or at equal intervals parallel to the second direction. The length of the intervals between the second light-emitting elements 32 mounted on the second mounting areas 52 and 53 in the first direction can be greater than the length of the intervals between the first light-emitting elements 31 mounted on the first mounting area 51 in the first direction. The length of the intervals between the second light-emitting elements 32 mounted on the second mounting areas 52 and 53 in the second direction can be greater than the length of the intervals between the first light-emitting elements 31 mounted on the first mounting area 51 in the second direction. In this embodiment, the second light-emitting elements 32 mounted on the second mounting areas 52 and 53 are arranged parallel to the first direction at intervals of 1.0 mm, and parallel to the second direction at intervals of 1.0 mm. In this case, the gap between adjacent second light-emitting elements 32 is 0.3 mm, which is smaller than the vertical and horizontal dimensions of each second light-emitting element 32.

[0029] The first direction is a direction in which the first mounting area 51 and the second mounting areas 52 and 53 are arranged adjacent to each other in a stripe shape.

[0030] Furthermore, in this embodiment, the gap in the first direction between each first light-emitting element 31 of the first light-emitting element column 71 installed at both ends of the first mounting area 51 and each second light-emitting element 32 of the second light-emitting element column 72, 73 installed at one end adjacent to the first light-emitting element column 71 of a pair of second mounting areas 52, 53 is the same as the gap between the elements, and is smaller than the dimensions of the respective longitudinal and transverse sides of each element of the first light-emitting element 31 and the second light-emitting element 32.

[0031] As described above, in this embodiment, the gaps between the first and second light-emitting elements 31 and 32, the gaps between the first and second light-emitting element columns 71 and 72 and 73, and the gaps between the first and second light-emitting element columns 71 and 72 and 73 are all smaller than the vertical and horizontal dimensions of each element. Therefore, light emitted from the light-emitting region of the light-emitting device achieves excellent color mixing between the elements, suppressing color unevenness. Consequently, a lighting device or the like using this light-emitting device can achieve excellent lighting effects with minimal color unevenness.

[0032] The first power pad 81, the opposing electrode pad 84, the second power pad 82, and the third power pad 83 are wiring patterns formed on the upper surface of the substrate 10 from a conductive thin film such as copper, arranged near the mounting area 50. The first power pad 81, the opposing electrode pad 84, the second power pad 82, and the third power pad 83 may also be gold-plated. Furthermore, the first power pad 81, the opposing electrode pad 84, the second power pad 82, and the third power pad 83 are preferably covered by a reflective frame 11 that surrounds a rectangular light-emitting surface 40, described later, in a rectangular frame shape. The reflective frame 11 serves as a rectangular frame-shaped barrier disposed around the first light-emitting element group 61 and the second light-emitting element groups 62 and 63. The first power pad 81, the opposing electrode pad 84, the second power pad 82, and the third power pad 83 are arranged on the lower surface of the barrier.

[0033] On the upper surface of the substrate 10, a first power supply pad 81 is arranged near the first mounting area 51. The first power supply pad 81 is connected to the first power supply terminal 21 via a first power supply wiring 91. The first power supply pad 81 is connected to the anode electrode of each of the first light-emitting elements 31 at the head end of the first light-emitting element array 71 constituting the first light-emitting element group 61 via a bonding wire 14. The light-emitting element at the head end of a light-emitting element array described in this specification refers to a light-emitting element whose anode electrode is connected to the power supply pad at one end of a light-emitting element array consisting of a plurality of light-emitting elements connected in series via a bonding wire.

[0034] The opposing electrode pads 84 are arranged on the upper surface of the substrate 10 near the mounting area 50 opposite the first power pad 81, sandwiching the first mounting area 51. The opposing electrode pads 84 are connected to the cathode electrodes of the first light-emitting elements 31 at the end of each of the first light-emitting element columns 71 constituting the first light-emitting element group 61 via bonding wires 14. Furthermore, the opposing electrode pads 84 are connected to the anode electrodes of the second light-emitting elements 32 at the beginning of each of the second light-emitting element columns 72 and 73 constituting the second light-emitting element groups 62 and 63 via bonding wires 14. The light-emitting elements at the end of a light-emitting element column described in this specification refer to light-emitting elements whose cathode electrodes are connected to the power pads at the other end of a light-emitting element column consisting of a plurality of light-emitting elements connected in series via bonding wires.

[0035] The second power pads 82 and the third power pads 83 are arranged on the upper surface of the substrate 10 near the second mounting areas 52 and 53, facing the counter electrode pad 84, with the second mounting areas 52 and 53 sandwiched therebetween. The second power pads 82 and the third power pads 83 are connected to the second power terminals 22 via the second power wiring 92. The second power pads 82 and the third power pads 83 are connected to the cathode electrodes of the second light-emitting elements 32 at the ends of the second light-emitting element columns 72 and 73 constituting the second light-emitting element groups 62 and 63, respectively, via bonding wires 14.

[0036] On the upper surface of the substrate 10 , the first power supply pad 81 , the second power supply pad 82 , and the third power supply pad 83 are arranged near the same side of the mounting region 50 as the counter electrode pad 84 , with the mounting region 50 sandwiched therebetween.

[0037] The bonding wire 14 is a conductive wire made of a conductor such as gold or copper. The portions electrically connected by the bonding wire 14 may be connected by a wiring pattern made of a conductive thin film such as copper disposed on the upper surface of the substrate 10 instead of the bonding wire 14 .

[0038] The first power supply wiring 91 and the second power supply wiring 92 are wiring patterns formed from a conductive thin film such as copper, arranged on the upper surface of the substrate 10. The first power supply wiring 91 connects the first power supply terminal 21 and the first power supply pad 81. The second power supply wiring 92 connects the second power supply terminal 22, the second power supply pad 82, and the third power supply pad 83. The first power supply wiring 91 and the second power supply wiring 92 can be covered with an insulating film 13 called a solder resist. The first power supply wiring 91 and the second power supply wiring 92 can each be composed of multiple wiring patterns connected via conductive jumper components. An electronic component such as a Zener diode or a capacitor can also be connected between the first power supply wiring 91 and the second power supply wiring 92.

[0039] The reflective frame 11 is made of a synthetic resin such as silicone containing white particles such as titanium oxide and has a light reflectivity of 80% or more. The reflective frame 11 is disposed on the upper surface of the substrate 10 to surround the light emitting element group 60 and serves as a barrier to prevent the sealing material 12 from flowing out.

[0040] Sealing material 12 is a synthetic resin material based on a transparent resin such as silicone resin and containing a phosphor. Sealing material 12 is arranged to cover mounting area 50 and light-emitting element group 60 within the area surrounded by reflective frame 11. The phosphor contained in sealing material 12 may be, for example, YAG, CASN, SCASN, KSF, or a mixture thereof. It serves as a wavelength conversion component that absorbs blue light emitted by first and second light-emitting elements 31 and 32 and converts the wavelength of the light into red, green, yellow, or other light.

[0041] The light emitting device 1 emits synthesized light of blue light emitted from the first and second light emitting elements 31 and 32 and wavelength-converted light emitted from the phosphor contained in the sealing material 12 from the light emitting surface 40 which is the upper surface of the sealing material 12 .

[0042] The light exit surface 40 formed into a rectangular shape has a first light exit area 41, which is the central portion of the surface area including the center point of the light exit surface 40, and a pair of second light exit areas 42 and 43, which are arranged on both sides of the first light exit area 41 and are surface areas that do not include the first light exit area 41. The first light exit area 41 and the second light exit areas 42 and 43 are areas that overlap with the first mounting area 51 and the second mounting areas 52 and 53 in the same position and shape when viewed from above.

[0043] like Figure 1A 、 Figure 1B and Figure 3 As shown, when a potential difference greater than a threshold value is applied between the first power terminal 21 and the second power terminal 22, the light emitting device 1 causes current to flow from the first power terminal 21 to the second power terminal 22, and power is supplied. Figure 2 As shown, the plurality of first light emitting elements 31 and the plurality of second light emitting elements 32 constituting the light emitting element group 60 mounted in the mounting area 50 are lit.

[0044] The number of first light-emitting element columns 71 constituting the first light-emitting element group 61 is smaller than the sum of the number of second light-emitting element columns 72 and 73 constituting the second light-emitting element groups 62 and 63. Therefore, the current value flowing through each of the plurality of first light-emitting elements 31 constituting the first light-emitting element group 61 is greater than the current value flowing through each of the plurality of second light-emitting elements 32 constituting the second light-emitting element groups 62 and 63.

[0045] Therefore, the light flux emitted by each of the plurality of first light emitting elements 31 constituting the first light emitting element group 61 mounted in the first mounting area 51 is greater than the light flux emitted by each of the plurality of second light emitting elements 32 constituting the second light emitting element groups 62 and 63 .

[0046] The plurality of first light-emitting elements 31 constituting the first light-emitting element group 61 and the plurality of second light-emitting elements 32 constituting the second light-emitting element groups 62 and 63 are arranged at equal intervals in the first mounting area 51 and the second mounting areas 52 and 53, respectively. Therefore, the average brightness of the light emitted from the first light-emitting area 41 is higher than the average brightness of the light emitted from the second light-emitting areas 42 and 43.

[0047] Figure 4A and Figure 4B This graph shows the shift in front chromaticity when the column ratio is set to 1, 2, 3, and 4. Here, the "column ratio" refers to the value obtained by dividing the sum of the number of columns of the second light-emitting element columns 72 and 73 constituting the second light-emitting element groups 62 and 63 by the number of columns of the first light-emitting element column 71 constituting the first light-emitting element group 61. Figure 4A and Figure 4B The black dots shown in are XY chromaticity coordinates representing the centers of the color temperatures 2700K and 5000K standardized by ANSI NEMA ANSLG C78.377-2015. Figure 4A and Figure 4B The range enclosed by the shown quadrilateral is XY chromaticity coordinates representing the allowable range of color temperatures 2700K and 5000K standardized by ANSI NEMA ANSLG C78.377-2015.

[0048] like Figure 4A As shown in FIG. 1 , if the phosphor contained in the sealing material 12 is set so that the column ratio is set to 1 and the color temperature falls within the allowable range of 2700K, setting the column ratio to 4 will exceed the allowable range, and the phosphor setting conditions must be changed. On the other hand, if the column ratio is 3 or less, it falls within the allowable range, and the phosphor setting conditions do not need to be changed. Therefore, the column ratio is preferably 3 or less.

[0049] In addition, if Figure 4B As shown in FIG. 1 , if the phosphor contained in the sealing material 12 is set so that the column ratio is set to 1 and the color temperature falls within the permissible range of 5000K, setting the column ratio to 3 deviates from the permissible range, and the phosphor setting conditions must be changed. On the other hand, if the column ratio is 2 or less, the phosphor falls within the permissible range, and no change in the phosphor setting conditions is required. Therefore, the column ratio is more preferably 2 or less.

[0050] Then, according to Figures 5 to 7The relationship between the spacing between light emitting elements and color unevenness with respect to the element size of each light emitting element in the light emitting element group 60 constituting the light emitting surface 40 in the light emitting device 1 will be described. The spacing between light emitting elements is also called element pitch. Figure 5 The diagram schematically shows the color unevenness of the light emitted from the concentrator of the light-emitting device. The annular black band 8 represents the portion where the light emitted from each light-emitting element appears as well-mixed light, and the annular white band 9 represents the portion where the light emitted from each light-emitting element appears as uneven color due to insufficient color mixing. Since the aberration of the light emitted from the concentrator in the sagittal direction B (rotational direction) is greater than the aberration in the tangential direction A (radial direction), as shown in FIG. Figure 5 As shown, the color unevenness is displayed in multiple layers in the shape of concentric circles.

[0051] Figure 6 These are examples showing different element size ratios depending on the element arrangement. Incidentally, element size ratio = element size / element spacing. The example of element arrangement shown in (a) is a case where the element size is 1 and the element spacing is 5, and the element size ratio is about 20%. In this case, the gap between the elements is 4 times the element size. The example of element arrangement shown in (b) is a case where the element size is 1 and the element spacing is 2, and the element size ratio is about 50%. In this case, the gap between the elements is roughly the same as the element size. The example of element arrangement shown in (c) is a case where the element size is 1 and the element spacing is 1.25, and the element size ratio is 80%. In this case, the gap between the elements is much smaller than the element size.

[0052] Figure 7 This is a graph showing the area ratio of color unevenness in a light emitting device relative to the element size ratio. The area ratio of color unevenness is calculated based on the Figure 5 The calculation is based on the areas of the black band 8 and the white band 9. Furthermore, the color unevenness area ratio is expressed as: area of ​​white band / area of ​​black band + area of ​​white band. This graph shows that the color unevenness area ratio varies significantly above a component size ratio of 50%, but color unevenness is less likely to occur above 50%. This indicates that setting the gap between adjacent components to be equal to or smaller than the component size effectively suppresses color unevenness.

[0053] Figure 8FIG2 shows a light-emitting device 1-1 according to a second embodiment of the present invention. This light-emitting device 1-1 comprises a rectangular reflective frame 11 surrounding a rectangular light-emitting surface 40. As in the previous embodiment, the light-emitting surface 40 comprises a first light-emitting region, which is the central portion of the surface region including the center of gravity of the light-emitting surface, and a pair of second light-emitting regions disposed on either side thereof. A first light-emitting element group 60 corresponds to the first light-emitting region, and second light-emitting element groups 62 and 63 correspond to the second light-emitting region. The first and second light-emitting element groups constitute a light-emitting element group mounted in the mounting area of ​​the light-emitting surface.

[0054] In this embodiment, the first light-emitting element group 61 is composed of three first light-emitting element columns 71. Furthermore, each first light-emitting element column 71 is composed of six first light-emitting elements 31. The plurality of first light-emitting elements 31 constituting the first light-emitting element columns 71 are connected in series via bonding wires 14. Furthermore, the three first light-emitting element columns 71 constituting the first light-emitting element group 61 are connected in parallel via bonding wires 14 between first power supply pads 81 and counter electrode pads 84, which are located on both sides of the first light-emitting element column 71 and sandwich the first light-emitting element column 71.

[0055] The second light-emitting element groups 62 and 63, arranged on either side of the first light-emitting element group 61, are each composed of two second light-emitting element columns 72 and 73. Furthermore, the second light-emitting element columns 72 and 73 are each composed of six second light-emitting elements 32. The plurality of second light-emitting elements 32 constituting the second light-emitting element columns 72 and 73 are connected in series via bonding wires 14. The plurality of second light-emitting element columns 72 and 73 constituting the second light-emitting element groups 62 and 63 are connected in parallel via bonding wires 14 between the opposing electrode pads 84, the second power supply pads 82, and the third power supply pads 83, which are arranged to sandwich the second light-emitting element columns 72 and 73 and are located on either side thereof.

[0056] In this embodiment, the gap between the first and second light emitting elements 31 and 32 is smaller than the light emitting element size. In addition, the gap between the first and second light emitting element columns 71, 72, and 73 is also smaller than the light emitting element size.

[0057] In the light-emitting device 1-1 of this embodiment, a first power supply pad 81, a second power supply pad 82, a third power supply pad 83, and a counter electrode pad 84 are provided on the lower surface of a rectangular frame-shaped reflective frame 11 surrounding the light-emitting surface 40. The first power supply pad 81 is connected to a first power supply terminal (not shown), while the second power supply pad 82 and the third power supply pad 83 are connected to a second power supply terminal (not shown). When current flows from the first power supply terminal to the second power supply terminal, the plurality of first light-emitting elements 31 and the plurality of second light-emitting elements 32 constituting the light-emitting element group mounted in the mounting area are illuminated.

[0058] As in the first embodiment, the number of first light-emitting element columns 71 constituting the first light-emitting element group 61 is less than the sum of the number of second light-emitting element columns 72 and 73 constituting the second light-emitting element groups 62 and 63. Therefore, the current flowing through each of the plurality of first light-emitting elements 31 constituting the first light-emitting element group 61 is greater than the current flowing through each of the plurality of second light-emitting elements 32 constituting the second light-emitting element groups 62 and 63. Consequently, the light flux emitted by each of the plurality of first light-emitting elements 31 constituting the first light-emitting element group 61 mounted in the first mounting area is greater than the light flux emitted by each of the plurality of second light-emitting elements 32 constituting the second light-emitting element groups 62 and 63. Furthermore, the plurality of first light-emitting elements 31 constituting the first light-emitting element group 61 and the plurality of second light-emitting elements 32 constituting the second light-emitting element groups 62 and 63 are arranged at equal intervals in the first mounting area and the second mounting area, respectively. Consequently, the average brightness of light emitted from the first light-emitting area is higher than the average brightness of light emitted from the second light-emitting area.

[0059] Figure 9 FIG2 shows a light-emitting device 1-2 according to a third embodiment of the present invention. This light-emitting device 1-2 has the same structure as the light-emitting device 1-1 according to the second embodiment, except for the shape of the light-emitting surface 40, the shape of the reflective frame 11, and the arrangement of the light-emitting elements. Therefore, common components are given the same reference numerals, and detailed descriptions are omitted. This light-emitting device 1-2 is surrounded by a circular light-emitting surface 40 formed by an annular reflective frame 11. Furthermore, a first power supply pad 81, a second power supply pad 82, a third power supply pad 83, and an opposing electrode pad 84 are provided on the lower surface of the rectangular reflective frame 11 surrounding the light-emitting surface 40.

[0060] In this embodiment, the three first light-emitting elements 31 at each end of each of the three first light-emitting element columns 71 that comprise the first light-emitting element group 61 are positioned close to the reflective frame 11, specifically, at the vertices of a triangle. Furthermore, the two left and right second light-emitting element columns 72 and 73 that comprise the second light-emitting element groups 62 and 63 are arranged so as to describe a curve along the reflective frame. This arrangement of the first and second light-emitting elements 31 and 32 corresponds to the circular light-emitting surface 40, thereby achieving sufficient brightness and suppressing color unevenness in the portion of the reflective frame 11 that is close to the light-emitting surface 40.

[0061] Figure 10 A light-emitting device 1-3 according to a fourth embodiment of the present invention is shown. This light-emitting device 1-3 has the same structure as the light-emitting device 1-1 according to the second embodiment, except for the arrangement shape of the light-emitting elements and the number of light-emitting element rows. Therefore, common components are given the same reference numerals, and detailed descriptions thereof are omitted.

[0062] In this embodiment, the first light-emitting element column 71 constituting the first light-emitting element group 61 is only one column. In addition, the six first light-emitting elements 31 constituting the first light-emitting element column 71 are arranged in the central portion of the light-emitting surface 40. On the other hand, the second light-emitting element columns 72 and 73 constituting the second light-emitting element groups 62 and 63 are composed of a total of 12 second light-emitting elements 32, which are arranged so as to surround the first light-emitting element 31. In addition, two second light-emitting element columns 72 and 73 are formed by six second light-emitting elements 32 each. In this way, the first light-emitting element 31 is arranged in the central portion of the light-emitting surface 40, and the second light-emitting elements 32 surround it. Therefore, the brightness of the central portion of the light-emitting surface 40 becomes high, and the brightness of the surrounding portion becomes uniform.

[0063] Figure 11 and Figure 12 FIG. 5 shows a light-emitting device 1-4 according to a fifth embodiment of the present invention. This light-emitting device 1-4 comprises a first light-emitting element group 61 and a pair of second light-emitting element groups 62 and 63 disposed on either side of the mounting area of ​​the light-emitting surface 40. One side of each of the second light-emitting element groups 62 and 63 is connected to a first power supply pad 81, and the other side is connected to a second power supply pad 82. The first and second power supply pads 81 and 82 are disposed on the lower surface of the annular reflective frame 11 surrounding the light-emitting surface 40. When current flows from the first power supply terminal (not shown) to the second power supply terminal 22, the plurality of first light-emitting elements 31 constituting the first light-emitting element group 61 and the plurality of second light-emitting elements 32 constituting the second light-emitting element groups 62 and 63 are illuminated.

[0064] The first light-emitting element group 61 includes two first light-emitting element columns 71, each including two first light-emitting elements 31. A pair of second light-emitting element groups 62 and 63 includes four second light-emitting element columns 72 and 73, respectively, each including one second light-emitting element 32. The two first light-emitting element columns 71 are connected in parallel. Furthermore, the four second light-emitting element columns 72 and 73 are also connected in parallel, but the first light-emitting element columns 71 and the second light-emitting element columns 72 and 73 are directly connected in series using bonding wires 14, without electrode pads interposed therebetween.

[0065] The first light-emitting element 31 of the first light-emitting element row 71 and the second light-emitting element 32 of the second light-emitting element rows 72 and 73 that are directly connected may also have multiple bonding wires 14 connected to their respective anode electrodes or cathode electrodes. For process and durability reasons, the number of bonding wires 14 connected to one anode electrode or cathode electrode is preferably two or less. In other words, the row number ratio, which is the value obtained by dividing the sum of the number of rows of the second light-emitting element rows 72 and 73 constituting the second light-emitting element groups 62 and 63 by the number of rows of the first light-emitting element row 71 constituting the first light-emitting element group 61, is preferably 2 or less.

[0066] and Figure 10 The arrangement of the light-emitting elements in the fourth embodiment shown is the same, with four first light-emitting elements 31 arranged in the center of the light-emitting surface 40, surrounded by eight second light-emitting elements 32. In this embodiment, since the first light-emitting elements 31 are arranged in the center of the light-emitting surface 40 and the second light-emitting elements 32 surround it, the brightness of the center of the light-emitting surface 40 is high, while the brightness of the surrounding area is uniform.

[0067] Figure 13The sixth embodiment of the present invention is shown as a light-emitting device 1-5. This light-emitting device 1-5 is similar to the light-emitting device 1-4 of the fifth embodiment. A pair of second light-emitting element groups 62 and 63 are arranged on either side of a first light-emitting element group 61. One side of the pair of second light-emitting element groups 62 and 63 is connected to a first power supply pad 81, and the other side is connected to a second power supply pad 82. However, the light-emitting device 1-4 of the fifth embodiment differs in that the first light-emitting element column 71 constituting the first light-emitting element group 61 and the second light-emitting element columns 72 and 73 constituting the pair of second light-emitting element groups 62 and 63 are connected via opposing electrode pads. Specifically, opposing electrode pad 84A connects the other end of the second light-emitting element column 72, which is connected to the first power supply pad 81, and one end of the first light-emitting element column 71. Opposing electrode pad 84b connects the other end of the first light-emitting element column 71 and one end of the second light-emitting element column 73, which is connected to the second power supply pad 82. These power pads and electrode pads are arranged on the lower surface side of a rectangular or annular reflective frame surrounding the light emitting surface. When current flows from the first power terminal to the second power terminal, the multiple first light-emitting elements 31 constituting the first light-emitting element group 61 and the multiple second light-emitting elements 32 constituting the second light-emitting element groups 62 and 63 are lit.

[0068] The first light-emitting element group 61 includes two first light-emitting element columns 71, each of which includes two first light-emitting elements 31. A pair of second light-emitting element groups 62 and 63 includes three second light-emitting element columns 72 and 73, respectively, each of which includes three second light-emitting elements 32. The two first light-emitting element columns 71 are connected in parallel. Furthermore, the three second light-emitting element columns 72 and 73 are also connected in parallel, but the first light-emitting element columns 71 and the second light-emitting element columns 72 and 73 are connected in series via opposing electrode pads 84a and 84b.

[0069] Figure 14A It means using Figure 15A 、 Figure 15B The lighting device 3 of this embodiment shown and Figure 17A 、 Figure 17B The characteristic diagram (part 1) of the luminous intensity distribution of the lighting device of the comparative example light emitting device 2 is shown. Figure 14B This is a characteristic diagram (part 2) showing the luminous intensity distribution of a lighting device using the lighting device 3 of this embodiment and the light-emitting device 2 of the comparative example.

[0070] Figure 15A This is a front view of the lighting device 3 of this embodiment. Figure 15B It is a plan view of the lighting device 3 according to this embodiment.

[0071] Illuminating device 3 of this embodiment includes: a light-emitting device 1; a reflector 4 serving as a concentrator for converging and emitting light emitted by light-emitting device 1; and a base 5 having a flat upper surface on which light-emitting device 1 and reflector 4 are mounted. Light-emitting device 1 is disposed on the upper surface of base 5 and emits light when supplied with power from an external power supply (not shown).

[0072] The reflector 4 has an upper surface opening 402 and a bottom surface opening 403, with a reflecting surface 401 disposed between the upper surface opening 402 and the bottom surface opening 403. The bottom surface opening 403 is an opening provided on the upper surface of the base 5 so as to cover the light-emitting device 1. The reflecting surface 401 reflects light emitted by the light-emitting device 1 toward the upper surface opening 402. The upper surface opening 402 is an opening through which the light reflected by the reflecting surface 401 is emitted. When viewed from above, the reflecting surface 401 has a circular shape, and the center of gravity of the light-emitting surface 40 of the light-emitting device 1 is aligned with the center of the circle defining the outer shape of the reflecting surface 401. When viewed from above, light emitted from the center of the circle defining the outer shape of the reflecting surface 401 is concentrated and efficiently emitted from the upper surface opening 402. As an example, the outermost diameter of the reflecting surface 401 is 60 mm, and the distance from the bottom surface opening 403 to the upper surface opening 402 is 45 mm. In addition, as a concentrator other than the reflector 4, for example, Figure 16 The condenser lens 7 is shown. The condenser lens 7 is arranged to cover the upper portion of the light emitting device 1 and has an incident surface 7a for receiving light emitted from the light emitting device 1, a reflecting surface 7b for reflecting light incident into the lens, and an emitting surface 7c for emitting light in the lens upward.

[0073] The lighting device 3 emits light having a luminous intensity Lθ (cd) in a direction forming an angle θ (°) with an axis P, which passes through the center of the circle forming the outer shape of the reflecting surface 401 when viewed from above and extends parallel to the normal to the upper surface of the base 5. Using a photometer (not shown), the luminous intensity Lθ is measured at a position equidistant from point O, the intersection of axis P and the upper surface of the base 5. The distance between point O and the position where the luminous intensity is measured is referred to as the far-field region and, as an example, is 1 meter.

[0074] The lighting device using the comparative example light emitting device 2 differs from the lighting device 3 in that the light emitting device 2 is used instead of the light emitting device 1. The configuration and functions of the components other than the use of the light emitting device 2 are substantially the same as those of the lighting device 3.

[0075] Figure 17A is a front view of a light emitting device 2 of a comparative example, Figure 17B FIG. 2 is a circuit diagram of a light emitting device 2 according to a comparative example. Figure 17A , the bonding wire 14 is omitted.

[0076] The light-emitting device 2 of the comparative example differs from the light-emitting device 1 in that it includes a first power supply wire 291, a second power supply wire 292, and a first power supply pad 281 instead of the first power supply wire 91, the second power supply wire 92, and the first power supply pad 81, and does not include the second power supply pad 82 and the third power supply pad 83. Furthermore, the light-emitting device 2 of the comparative example differs from the light-emitting device 1 in that it does not include the second light-emitting element 32, but instead includes the same number of first light-emitting elements 31 as the first light-emitting elements 31 and the second light-emitting elements 32 of the light-emitting device 1, with the first light-emitting elements 31 of the light-emitting device 2 being connected in the same direction. The configuration and function of the components of the light-emitting device 2 other than the first power supply wire 291, the second power supply wire 292, the first power supply pad 281, and the first light-emitting elements 31 are identical to those of the components of the light-emitting device 1 designated by the same reference numerals, and therefore detailed descriptions thereof will be omitted.

[0077] The light-emitting device 2 includes a first power terminal 21 and a second power terminal 22 as a pair of power terminals. The first power terminal 21 is connected to the first power pad 281 via a first power wiring 291, and the second power terminal 22 is connected to the opposing electrode pad 84 via a second power wiring 292. A light-emitting element row consisting of eight first light-emitting elements 31 connected in series via bonding wires 14 is arranged between the first power pad 281 and the opposing electrode pad 84. Furthermore, by connecting ten of these light-emitting element rows in parallel in the same direction, 80 first light-emitting elements 31 are connected between the first power terminal 21 and the second power terminal 22. Each light-emitting element row includes a first light-emitting element 31 at the leading end, whose anode electrode is connected to the first power pad 281 via a bonding wire 14, and a first light-emitting element 31 at the trailing end, whose cathode electrode is connected to the opposing electrode pad 84 via a bonding wire 14.

[0078] When the light-emitting device 2 supplies power between the first power terminal 21 and the second power terminal 22, currents of the same current value flow through the 80 first light-emitting elements 31 connected between the first power terminal 21 and the second power terminal 22, so the light beam amounts emitted by each first light-emitting element 31 are equal.

[0079] Figure 14A W1 and W2 shown are graphs showing luminous intensity distribution when the same amount of power W is supplied to the lighting device 3 using the light-emitting device 1 and the lighting device using the light-emitting device 2, respectively. Figure 14A The horizontal axis of the characteristic diagram shown represents the value of the light emission angle θ (in degrees), and the vertical axis represents the value of the normalized luminous intensity ratio in θ, which represents the value of the normalized luminous intensity ratio when the luminous intensity Lθ at θ = 0 when the power W is supplied to the lighting device using the light-emitting device 2 is set to 1.00.

[0080] exist Figure 14A , the value of W2 when θ = 0 is 1.00, while the value of W1 is 1.15. In the range of -5 ≤ θ ≤ 5, the value of W1 is greater than the value of W2, and the difference between the values ​​of W1 and W2 is greater than 0.03. Near θ = ± 6.5, the values ​​of W1 and W2 are equal. In the range of θ ≤ -7 or 7 ≤ θ, the value of W1 is smaller than the value of W2, and the difference between the values ​​of W1 and W2 is greater than -0.01 and less than 0.00. The lighting device 3 of this embodiment can improve the illumination in a specific direction compared to the lighting device using the light-emitting device 2 supplied with the same amount of power W.

[0081] Figure 14B The horizontal and vertical axes of the characteristic diagrams shown represent Figure 14A The values ​​indicated on the horizontal axis and the vertical axis of the characteristic graph shown are the same values.

[0082] Figure 14B W1 shown with Figure 14A The same curve as W1 is shown, representing the luminous intensity distribution when power of amount W is supplied to lighting device 3. W3 is a curve representing the luminous intensity distribution when power of amount Wa is supplied to a lighting device using light-emitting device 2. Power amount Wa is the amount of power obtained by setting the value of W3 when θ = 0 to be equal to the value of W1 when θ = 0. As an example, power amount Wa is 1.2 times the power amount W.

[0083] exist Figure 14B In the example, when θ = 0, the values ​​of W1 and W3 are both 1.15. In the region of values ​​other than θ = 0, the value of W3 is higher than that of W1. For example, when θ = 6.5, the value of W1 is 0.66, and the value of W3 is 0.76.

[0084] The lighting device 3 reduces the amount of electric power supplied compared to the lighting device using the light-emitting device 2 set to have the same luminous intensity in the front direction.

[0085] The light emitting device 1 of this embodiment can efficiently improve irradiation in a specific direction compared to the light emitting device 2 .

[0086] Figure 14C The horizontal and vertical axes of the characteristic diagrams shown represent Figure 14A The values ​​indicated on the horizontal axis and the vertical axis of the characteristic graph shown are the same values. Figure 14C W2 shown with Figure 14AThe same curve W2 is shown, representing the luminous intensity distribution when power W is supplied to a lighting device using light-emitting device 2. A curve W4 represents the luminous intensity distribution when power Wb is supplied to lighting device 3. Power Wb is lower than power W. When θ < |5|, the value of W4 is higher than the value of W2. When θ > |5|, the value of W4 is set to a lower value than the value of W2. As an example, power Wb is 0.96 times the power W.

[0087] exist Figure 14C , the value of W4 when θ=0 is 1.10, which is higher than W2; the value of W4 when θ<|5| is higher than W2; the value of W4 when θ=|5| is approximately the same as W2; and the value of W4 when θ>|5| is lower than W2.

[0088] Compared to a lighting device using a light-emitting device 2 whose luminous intensity is set to the same front direction, the lighting device 3 can enhance emission in a specific direction (for example, in the range of θ<|5|), weaken emission in directions other than the specific direction (for example, in the range of θ>|5|), and can reduce the amount of electric power supplied.

[0089] Figure 18 It is a perspective view of a light emitting device 1-6 according to a seventh embodiment of the present invention.

[0090] The light-emitting device 1-6 of the seventh embodiment differs from the light-emitting device 1 in that it includes a substrate 610 and a plurality of light-emitting surfaces 640a to 640d instead of the substrate 10 and the light-emitting surface 40. The configuration and functions of the components of the light-emitting device 2 other than the substrate 610 and the light-emitting surfaces 640a to 640d are identical to those of the light-emitting device 1, and therefore detailed description thereof will be omitted.

[0091] The front shape of the substrate 610 is different from the front shape of the substrate 10. The configuration and function other than the front shape are the same as those of the substrate 10. In this embodiment, the front shape of the substrate 610 is a square with a side of 40 mm.

[0092] Light emitting device 1-6 differs from light emitting device 1 in that it has multiple light emitting surfaces. In this embodiment, it has four light emitting surfaces 640a to 640d. The number of light emitting surfaces can be two, three, or five or more.

[0093] In light-emitting devices 1-6, when a potential difference greater than a threshold value is applied between a pair of power terminals, first power terminal 21 and second power terminal 22, current flows from first power terminal 21 to second power terminal 22, supplying power. When current flows from first power terminal 21 to second power terminal 22, light is emitted from each of the four light-emitting surfaces 640a to 640d.

[0094] The light exit surfaces 640 a to 640 d have the same configuration and function as the components of the light exit surface 40 , and are disposed separately from each other. Explanation of symbols

[0095] 1.1-1 to 1-6, 2 Light-emitting device 3 lighting fixtures 4 reflectors (concentrators) 5 abutments 7. Condenser lens (condenser) 7a Incident surface 7b Reflective surface 7c Exit surface 8 black belts 9 white belt 10. 610 substrate 11 Reflective frame 12 Sealing materials 13 Insulation film 14 Bonding wire 21 First power terminal 22 Second power terminal 31 first light-emitting element 32 second light emitting element 40, 640a~d light exit surface 41 first light emitting area 42, 43 Second light emitting area 50 installation area 51 First installation area 52, 53 Second installation area 60 light-emitting element groups 61 first light emitting element group 62, 63 second light emitting element group 71 first light emitting element row 72, 73 Second light emitting element row 81, 281 First power pad 82 Second power pad 83 Third power pad 84 Counter electrode pad 91, 291 First power supply wiring 92, 292 Second power supply wiring.

Claims

1. A light emitting device, characterized in that: have: substrate; a pair of power terminals disposed on the substrate; a plurality of first light emitting elements and a plurality of second light emitting elements that emit light when power is supplied between the pair of power terminals; as well as a light emitting surface for emitting light emitted by the plurality of first light emitting elements and the plurality of second light emitting elements, The light exit surface includes a first light exit area which is a surface area including the center of gravity of the light exit surface in a plan view, and a second light exit area which is a surface area not including the first light exit area. The plurality of first light emitting elements are arranged in the first light emitting region in a plan view and constitute a first light emitting element group, and the plurality of second light emitting elements are arranged in the second light emitting region in a plan view and constitute a second light emitting element group. The average brightness of light emitted from the first light emitting area is higher than the average brightness of light emitted from the second light emitting area.

2. The light emitting device according to claim 1, wherein The first light exit area is arranged at a central portion of the light exit surface in a plan view, and the second light exit areas are arranged on both sides of the light exit surface with the first light exit area interposed therebetween in a plan view.

3. The light emitting device according to claim 2, wherein: The light emitting surface is formed into a rectangle or a circle when viewed from above.

4. The light emitting device according to any one of claims 1 to 3, characterized in that The light emitting surface is surrounded by a rectangular or annular reflective frame.

5. The light emitting device according to claim 1, wherein The first light emitting element group includes at least one first light emitting element column in which the plurality of first light emitting elements are arranged, a gap between the plurality of first light emitting elements constituting the first light emitting element column is smaller than an element size of the first light emitting element, and the plurality of first light emitting elements are connected in series. The second light emitting element group includes a plurality of second light emitting element columns in which the plurality of second light emitting elements are arranged. A gap between the plurality of second light emitting elements constituting the second light emitting element columns is smaller than an element size of the second light emitting elements, and the plurality of second light emitting elements are connected in series.

6. The light emitting device according to claim 5, characterized in that The plurality of first light emitting elements and the plurality of second light emitting elements are respectively connected in series via bonding wires.

7. The light emitting device according to claim 5, characterized in that The power supplied to the first light emitting element is greater than the power supplied to the second light emitting element.

8. The light emitting device according to claim 5, characterized in that The first light emitting element group is composed of at least one first light emitting element column connected between the first power supply pad and the counter electrode pad. The second light emitting element group is composed of a plurality of second light emitting element columns connected in parallel between the counter electrode pad and the second power supply pad.

9. The light emitting device according to claim 8, characterized in that The first power supply pad and the counter electrode pad are arranged to sandwich the at least one first light emitting element column and are located on both sides thereof, and the counter electrode pad and the second power supply pad are arranged to sandwich the plurality of second light emitting element columns and are located on both sides thereof.

10. The light emitting device according to claim 9, characterized in that The first power pad, the counter electrode pad, and the second power pad are provided on the substrate and arranged on the lower surface side of a rectangular frame-shaped or ring-shaped stopper provided around the first and second light emitting element groups.

11. The light emitting device according to claim 9 or 10, characterized in that: The first power supply pad and the second power supply pad are arranged adjacent to each other, and the counter electrode pad is arranged at a position facing the first power supply pad and the second power supply pad.

12. The light emitting device according to claim 5, characterized in that A first light-emitting element group including at least one first light-emitting element column is sandwiched between two second light-emitting element groups each consisting of a plurality of second light-emitting element columns. The first light-emitting element group and the second light-emitting element group are connected in series, and the plurality of second light-emitting element columns are connected in parallel with each other.

13. The light emitting device according to claim 12, characterized in that: In the second light emitting element groups respectively arranged on both sides of the first light emitting element group, the first power supply pad is connected to one end of the second light emitting element column constituting one of the second light emitting element groups, and the second power supply pad is connected to the other end of the second light emitting element column constituting the other second light emitting element group.

14. The light emitting device according to claim 13, wherein: The opposing electrode pad is connected to the other end of the second light-emitting element column of the second light-emitting element group constituting the one side and one end of the first light-emitting element column constituting the first light-emitting element group, and the second power supply pad is connected to the other end of the first light-emitting element column and one end of the second light-emitting element column constituting the other side.

15. The light emitting device according to claim 8 or 12, characterized in that: The number of the at least one first light emitting element column is smaller than the number of the plurality of second light emitting element columns.

16. The light emitting device according to claim 1, wherein The light emitting device includes a plurality of light emitting surfaces, and the light emitting surfaces are arranged on a substrate so as to be separated from each other.

17. A lighting device, characterized in that: have: The light emitting device according to claim 1 and a concentrator arranged above the light emitting surface.

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