Light-emitting device

Abstract

To provide a light-emitting device meeting a demand for a custom-made color.SOLUTION: A light-emitting device comprises a first light-emitting element group and a second light-emitting element group. The first light-emitting element group includes a first element as a red light-emitting element and a second element as a color light-emitting element different from the first element. The second light-emitting element group includes the first element, the second element, and a third element as a color light-emitting element different from the first element and second element. The first elements and second element of the first light-emitting element group are connected in series. The first element, second element and third element of the second light-emitting element group are connected in series.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a light emitting device. [Background technology]

[0002] Light-emitting devices including light-emitting diodes (LEDs) are used as the light source of lighting fixtures. In particular, lighting fixtures that require high output and uniform light distribution use light-emitting devices of the COB (Chip on Board) type, SMD (Surface Mount Device) type, and CSP (Chip Scale Package) type. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-057201 Summary of the Invention [Problem to be solved by the invention]

[0004] Lighting fixtures for performance spaces may require lighting fixtures with a specific light color that is not used frequently. Since manufacturing LEDs or SMDs that emit a specific light color each time a specific light color is required, it is desirable to be able to meet the demand without manufacturing LEDs or SMDs that emit light of a custom color, as this would be costly and time consuming.

[0005] The problem that the present invention seeks to solve is to provide a light emitting device that can be tailored to meet custom color requirements. [Means for solving the problem]

[0006] The light emitting device of the embodiment includes a first light emitting element group and a second light emitting element group. The first light emitting element group includes a first element which is a red light emitting element and a second element which is a light emitting element of a color different from the first element. The second light emitting element group includes the first element, the second element, and a third element which is a light emitting element of a color different from the first element and the second element. The first element and the second element of the first light emitting element group are connected in series. The first element, the second element, and the third element of the second light emitting element group are connected in series. Effect of the Invention

[0007] According to the embodiment, it is possible to provide a light emitting device that meets the requirements of a custom color. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a light emitting device according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing an example of the configuration of the light source module. [Diagram 3] FIG. 3 is a diagram showing an example configuration of each light-emitting element in the light-emitting element group 4a and the light-emitting element group 4b that satisfies the required conditions for the light source device, for example, a color temperature of 3000K, a color deviation duv of 0, an average color rendering index Ra of 90 or more, and a luminous flux of 10000 lm. [Figure 4] FIG. 4 is a diagram showing examples of color temperature, deviation, general color rendering index, and luminous flux obtained in the example configuration of the light-emitting element in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The light emitting device (1) of the embodiment includes a first light emitting element group (4a) and a second light emitting element group (4b). The first light emitting element group (4a) includes a first element (41a) that is a red light emitting element and a second element (42a) that is a light emitting element of a color different from the first element (41a). The second light emitting element group (4b) includes the first element (41b), the second element (42b), and a third element (43b) that is a light emitting element of a color different from the first element and the second element. The first element (41a) and the second element (42a) of the first light emitting element group (4a) are connected in series. The first element (41b), the second element (42b), and the third element (43b) of the second light emitting element group (4b) are connected in series.

[0010] In the embodiment, the second elements (42a, 42b) are lime-colored light-emitting elements.

[0011] In the embodiment, the third element (43b) is a white light emitting element.

[0012] In the embodiment, the luminous flux ratio of the first elements (41a, 41b) to the second elements (42a, 42b) is 1:2.3-2.6.

[0013] In the embodiment, the luminous flux ratio of the first element (41a, 41b) to the third element (43b) is 1:1.5-2.3.

[0014] According to the above configuration, it is possible to provide a light emitting device that meets the requirements without requiring a wavelength conversion section for a custom color that meets the requirements.

[0015] Hereinafter, an embodiment will be described with reference to the drawings. Fig. 1 is a schematic diagram showing an example of a light emitting device according to an embodiment. The light emitting device 1 is a device that serves as a light source for a lighting fixture. The light emitting device 1 in the embodiment can be used as a light source for fixtures such as indoor downlights and spotlights.

[0016] As shown in FIG. 1, the light emitting device 1 includes a light source module 2, a plurality of power sources 3a and 3b, and a control unit 5.

[0017] The light source module 2 includes a plurality of light emitting element groups 4a and 4b, two in FIG. 1. The light emitting element group 4a is a light emitting element group that emits light with a lower color temperature than the light emitting element group 4b. The light emitting element group 4b is a light emitting element group that emits light with a higher color temperature than the light emitting element group 4a. As will be described in detail later, each of the light emitting element groups 4a and 4b includes a plurality of light emitting elements connected in series. The light emitting elements may be, for example, bare chip light emitting diodes (LEDs), SMD type light emitting elements, or CSP type light emitting elements. Each light emitting element of the light emitting element group 4a is connected to a power source 3a and emits light based on the power supplied from the power source 3a. The light emitting element group 4b is connected to a power source 3b and emits light based on the power supplied from the power source 3b.

[0018] The power source 3a is connected to the light-emitting element group 4a, and supplies power to the light-emitting element group 4a for causing each light-emitting element of the light-emitting element group 4a to emit light based on a control command from the control unit 5. The power source 3b is connected to the light-emitting element group 4b, and supplies power to the light-emitting element group 4b for causing each light-emitting element of the light-emitting element group 4b to emit light based on a control command from the control unit 5.

[0019] The control unit 5 is connected to the power source 3a and the power source 3b, and can control the power sources 3a and 3b independently. For example, when the light source module 2 is turned off, the control unit 5 controls the timing of turning off the light-emitting element group 4a by the power source 3a to be delayed from the timing of turning off the light-emitting element group 4b by the power source 3b. By turning off the light-emitting element group 4b on the high color temperature side first, the light-emitting device 1 turns off while emitting reddish light like a light bulb. The control unit 5 includes a processor or integrated circuit including a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), and a storage medium such as a memory. The control unit 5 may include only one processor or integrated circuit, or the like, or may include multiple processors or integrated circuits.

[0020] 2 is a schematic diagram showing an example of the configuration of the light source module 2. The light source module 2 has a substrate 21. On the substrate 21, light emitting elements constituting the light emitting element group 4a and light emitting elements constituting the light emitting element group 4b are arranged.

[0021] The light-emitting element group 4a includes a first element 41a and a second element 42a. The first element 41a is a red light-emitting element with a peak wavelength of 610-650 nm. The second element 42a is a green (lime) light-emitting element with a peak wavelength of 530-600 nm. In the example of FIG. 2, the number of elements in the first element 41a is 33, and the number of elements in the second element 42a is 11. The light-emitting element group 4a is a light-emitting element group on the low color temperature side, and therefore includes many light-emitting elements with a low color temperature, i.e., red, and does not include white light-emitting elements.

[0022] The light-emitting element group 4a has a configuration in which a first light-emitting element group, a second light-emitting element group, a third light-emitting element group, a fourth light-emitting element group, a fifth light-emitting element group, a sixth light-emitting element group, and a seventh light-emitting element group, each of which is composed of a plurality of light-emitting elements arranged in a straight line when viewed diagonally in FIG. 2, are arranged at intervals. The first light-emitting element group includes three first elements 41a and two second elements 42a connected in series, and is connected to the positive electrode 22a and the negative electrode 23b via the wiring L11. The second light-emitting element group includes five first elements 41a and two second elements 42a connected in series, and is connected to the positive electrode 22a and the negative electrode 23b via the wiring L12. The third light-emitting element group includes eight first elements 41a connected in series, and is connected to the positive electrode 22a and the negative electrode 23b via the wiring L13. The fourth light-emitting element group includes five first elements 41a and three second elements 42a connected in series, and is connected to the positive electrode 22a and the negative electrode 23b via the wiring L14. The fifth light-emitting element group includes six first elements 41a and one second element 42a connected in series, and is connected to the positive electrode 22a and the negative electrode 23b via the wiring L15. The sixth light-emitting element group includes five first elements 41a and two second elements 42a connected in series, and is connected to the positive electrode 22a and the negative electrode 23b via the wiring L16. The seventh light-emitting element group includes one first element 41a and one second element 42a connected in series, and is connected to the positive electrode 22a and the negative electrode 23b via the wiring L17. As shown in FIG. 2, the first light-emitting element group to the seventh light-emitting element group are connected to the wiring L11 to the wiring L17 so that they are connected in series. The positive electrode 22a and the negative electrode 23b are connected to a power source 3a.

[0023] The light-emitting element group 4b includes a first element 41b, a second element 42b, and a third element 43b. The first element 41a is a red light-emitting element having a peak wavelength of 610-650 nm. The first element 41b may be a light-emitting element having the same peak wavelength as the first element 41a (i.e., the same element as the first element 41a), or may be a light-emitting element having a different peak wavelength. The second element 42b is a lime light-emitting element having a peak wavelength of 530-600 nm. The second element 42b may be a light-emitting element having the same peak wavelength as the second element 42a (i.e., the same element as the second element 42a), or may be a light-emitting element having a different peak wavelength. The third element 43b is a white light-emitting element having a color temperature of 5000 K or more. The white light-emitting element is formed by, for example, sealing a light-emitting element that emits light with an excitation wavelength of the phosphor in a sealing resin containing a phosphor. The third element 43b emits white light by mixing the fluorescence of the sealing resin and the light of the light-emitting element. 2, the number of elements in the first element 41b is 3, the number of elements in the second element 42b is 15, and the number of elements in the third element 43b is 26. The light-emitting element group 4b is a light-emitting element group on the high color temperature side, and therefore includes many light-emitting elements with a high color temperature, i.e., white.

[0024] The light-emitting element group 4b has a configuration in which a first light-emitting element group, a second light-emitting element group, a third light-emitting element group, a fourth light-emitting element group, a fifth light-emitting element group, a sixth light-emitting element group, and a seventh light-emitting element group, each of which is composed of a plurality of light-emitting elements arranged in a straight line when viewed diagonally in FIG. 2, are arranged between the light-emitting element groups of the light-emitting element group 4a. The first light-emitting element group includes one second element 41b and one third element 42b connected in series, and is connected to the positive electrode 22b and the negative electrode 23a via the wiring L21. The second light-emitting element group includes one first element 41b and six third elements 43b connected in series, and is connected to the positive electrode 22b and the negative electrode 23a via the wiring L22. The third light-emitting element group includes one first element 41b, four second elements 42b, and two third elements 43b connected in series, and is connected to the positive electrode 22b and the negative electrode 23a via the wiring L23. The fourth light-emitting element group includes three second elements 42b and five third elements 43b connected in series, and is connected to the positive electrode 22b and the negative electrode 23a via the wiring L24. The fifth light-emitting element group includes three second elements 42b and five third elements 43b connected in series, and is connected to the positive electrode 22b and the negative electrode 23a via the wiring L25. The sixth light-emitting element group includes one first element 41b, two second elements 42b, and four third elements 43b connected in series, and is connected to the positive electrode 22b and the negative electrode 23a via the wiring L26. The seventh light-emitting element group includes two second elements 42b and three third elements 43b connected in series, and is connected to the positive electrode 22b and the negative electrode 23a via the wiring L27. Then, as shown in FIG. 2, the wirings L21 to L27 are connected so that the first light-emitting element group to the seventh light-emitting element group are connected in series, respectively. The positive electrode 22b and the negative electrode 23a are connected to a power source 3b.

[0025] By arranging the first element 41a, the second element 42a, the first element 41b, the second element 42b, and the third element 43b as described above, the light emitting elements of the light emitting element group 4a and the light emitting element group 4b can be arranged in a substantially circular shape as a whole. Here, the arrangement of the first element 41a and the second element 42a of the light emitting element group 4a and the arrangement of the first element 41b, the second element 42b, and the third element 43b of the light emitting element group 4b are not limited to those shown in FIG. 2. However, it is preferable that the light emitting elements of each color are arranged in an evenly distributed manner. In particular, it is preferable that the colors of the light emitting elements adjacent in the circumferential direction in the outer periphery of the substantially circular light emitting element group are different. The outer periphery refers to, for example, the light emitting elements located on the outermost side of the substantially circular light emitting element group and the light emitting element located one element inside.

[0026] Furthermore, when the light emitting device 1 is used as a light source for a spotlight, it is desirable to determine the orientation of the light source module 2 according to the orientation of the band door. Specifically, it is desirable to determine the orientation of the light source module 2 so that light emitting elements of the same color are not consecutively arranged in a direction parallel to the orientation of the band door. For example, when band doors are attached to the upper, lower, left, and right parts of the light source module in Fig. 2, it is desirable to avoid consecutively arranging light emitting elements of the same color as much as possible in directions perpendicular to the faces of the respective band doors, specifically in the horizontal and vertical directions in Fig. 2.

[0027] 2, the first light-emitting element group, the second light-emitting element group, the third light-emitting element group, the fourth light-emitting element group, the fifth light-emitting element group, the sixth light-emitting element group, and the seventh light-emitting element group constituting the light-emitting element group 4a are connected in series. Similarly, the first light-emitting element group, the second light-emitting element group, the third light-emitting element group, the fourth light-emitting element group, the fifth light-emitting element group, the sixth light-emitting element group, and the seventh light-emitting element group constituting the light-emitting element group 4b are connected in series. In contrast, the first light-emitting element group, the second light-emitting element group, the third light-emitting element group, the fourth light-emitting element group, the fifth light-emitting element group, the sixth light-emitting element group, and the seventh light-emitting element group constituting the light-emitting element group 4a may be connected in parallel. Similarly, the first light-emitting element group, the second light-emitting element group, the third light-emitting element group, the fourth light-emitting element group, the fifth light-emitting element group, the sixth light-emitting element group, and the seventh light-emitting element group constituting the light-emitting element group 4b may be connected in parallel.

[0028] 2, separate electrodes are provided for the light-emitting element group 4a and the light-emitting element group 4b. In contrast, the negative electrode may be shared by the light-emitting element group 4a and the light-emitting element group 4b. In this case, only one negative electrode needs to be provided.

[0029] Furthermore, in the embodiment, the light emitting device 1 can emit illumination light according to various requirements by adjusting the luminous flux ratio of the red, lime, and white light emitting elements. The adjustment of the luminous flux ratio of the light emitting elements can be performed, for example, by changing the element number ratio of the red, lime, and white light emitting elements or by changing the type of the light emitting elements.

[0030] Fig. 3 is a diagram showing an example of the configuration of each of the light-emitting element groups 4a and 4b that satisfies the required conditions of the light source device with the smallest number of light-emitting elements when, for example, a color temperature of 3000K, a color deviation duv of 0, an average color rendering index Ra of 90 or more, and a luminous flux of 10000 lm are given as the required conditions of the light source device. Fig. 4 is a diagram showing examples of the color temperature, deviation, average color rendering index, and luminous flux obtained with the configuration example of the light-emitting elements in Fig. 3.

[0031] Here, in Fig. 3 and Fig. 4, the first element 41a and the second element 41b are red light-emitting elements having the same peak wavelength, and the second element 42a and the second element 42b are lime light-emitting elements having the same peak wavelength. Therefore, the number of red light-emitting elements shown in Fig. 3 is the total number of light-emitting elements of the first element 41a and the second element 41b. Similarly, the number of lime light-emitting elements shown in Fig. 3 is the total number of light-emitting elements of the second element 42a and the second element 42b. Moreover, the luminous flux of Fig. 3 is the luminous flux of each light-emitting element. On the other hand, the luminous flux of Fig. 4 is the total luminous flux of the light-emitting device 1.

[0032] Furthermore, in FIG. 3, the average color rendering index Ra of the third element 43b having a color temperature of 5000 K is 50, the average color rendering index Ra of the third element 43b having a color temperature of 5700 K is 80, and the average color rendering index Ra of the third element 43b having a color temperature of 6500 K is 50.

[0033] The total number of red light-emitting elements, lime light-emitting elements and white light-emitting elements, i.e., the total number of first elements 41a, second elements 42a, first elements 41b, second elements 42b and third elements 43b, is 88, the same as in Fig. 2. Therefore, the first configuration example, second configuration example and third configuration example shown below each correspond to a configuration in Fig. 2 in which light-emitting elements corresponding to the difference from Fig. 2 are replaced.

[0034] In the first configuration example, as shown in Fig. 3, there are 33 red light emitting elements, 34 lime light emitting elements, and 34 white light emitting elements with a color temperature of 5000K and Ra of 50. In the first configuration example, the luminous flux of the red light emitting elements is 1980lm, the luminous flux of the lime light emitting elements is 4725lm, and the luminous flux of the white light emitting elements is 4950lm. When these luminous fluxes are expressed as an emission luminous flux ratio, red:lime:white is approximately 1:2.4:2.3.

[0035] In the first configuration example, as shown in Fig. 4, the color temperature of the light emitting device 1 is 2986K, the color deviation duv is 0.00081, the average color rendering index Ra is 95.5, the special color rendering index R9 of red is 91.8, and the luminous flux is 10074lm. That is, the required conditions are satisfied by the first configuration example. Note that in the first configuration example, the special color rendering index R9 is 91.8. Therefore, even if a condition that the special color rendering index R9 is 90 or more is added to the required conditions, the required conditions are satisfied by the first configuration example.

[0036] In the second configuration example, as shown in Fig. 3, there are 34 red light emitting elements, 22 lime light emitting elements, and 32 white light emitting elements with a color temperature of 5700K and Ra of 80. In the second configuration example, the luminous flux of the red light emitting elements is 2040lm, the luminous flux of the lime light emitting elements is 4950lm, and the luminous flux of the white light emitting elements is 5400lm. When these luminous fluxes are expressed as an emission luminous flux ratio, red:lime:white is approximately 1:2.4:2.1.

[0037] In the second configuration example, as shown in Fig. 4, the color temperature of the light emitting device 1 is 3014K, the color deviation duv is -0.00141, the special color rendering index Ra is 95, the special color rendering index R9 is 97.9, and the luminous flux is 10079. That is, the required conditions are satisfied by the second configuration example as well. Note that in the second configuration example, the special color rendering index R9 is 97.9. Therefore, even if a condition that R9 is 90 or more is added to the required conditions, the required conditions are satisfied by the second configuration example.

[0038] In the third configuration example, as shown in Fig. 3, there are 36 red light emitting elements, 24 lime light emitting elements, and 28 white light emitting elements with a color temperature of 6500K and Ra of 50. In the third configuration example, the luminous flux of the red light emitting elements is 2160lm, the luminous flux of the lime light emitting elements is 5400lm, and the luminous flux of the white light emitting elements is 3780lm. When these luminous fluxes are expressed as an emission luminous flux ratio, red:lime:white is approximately 1:2.5:1.8.

[0039] In the third configuration example, the color temperature of the light emitting device 1 is 3014K, the color deviation duv is -0.00142, the average color rendering index Ra is 95, the special color rendering index R9 is 93.1, and the luminous flux is 10088. That is, the required conditions are satisfied by the third configuration example as well. Note that in the third configuration example, the special color rendering index R9 is 97.9. Therefore, even if a condition that R9 is 90 or more is added to the required conditions, the required conditions are satisfied by the third configuration example.

[0040] As described above, various configuration examples can be adopted for the same required conditions. Therefore, for example, when the required conditions of the light source device are given as described above, that is, a color temperature of 3000K, a color deviation duv of 0, an average color rendering index Ra of 90 or more, and a luminous flux of 10000 lm, the first element 41a, the second element 42a, the first element 41b, the second element 42b, and the third element 43b may be arranged so that the luminous flux ratio of red:lime:white is approximately 1:2.3-2.6:1.5-2.3.

[0041] In addition, as in the first configuration example, when an element having a color temperature of 5000K and an average color rendering index Ra of 50 is selected as the white light-emitting element, there is an advantage that the absolute value of the color deviation is smaller than in the other configuration examples. In addition, as in the second configuration example, when an element having a color temperature of 5700K and an average color rendering index Ra of 80 is selected as the white light-emitting element, there is an advantage that the special color rendering index Ra is larger than in the other configuration examples. Furthermore, as in the third configuration example, when an element having a color temperature of 6500K and an average color rendering index Ra of 50 is selected as the white light-emitting element, there is an advantage that the luminous flux is larger, that is, the efficiency is higher.

[0042] As described above, according to the embodiment, the light emitting device has light emitting elements of three colors, red, lime, and white. By simply adjusting the luminous flux ratio of these three color light emitting elements, a light emitting device with various light colors can be obtained with the minimum number of light emitting elements required and without the need for a wavelength conversion unit for a custom color according to the request.

[0043] According to the embodiment, the light-emitting elements of the three colors, red, lime, and white, are divided into a light-emitting element group on the low color temperature side that includes many red light-emitting elements and a light-emitting element group on the high color temperature side that includes many white light-emitting elements. The light-emitting element group on the low color temperature side and the light-emitting element group on the high color temperature side can be controlled independently. This allows the lighting fixture including the light-emitting device 1 to be turned on and off with the same light color as incandescent lighting. Each light-emitting element group includes light-emitting elements connected in series. These light-emitting elements connected in series can be made to emit light with the same current value.

[0044] (Modification) 2, the total number of light-emitting elements is the same in the light-emitting element group on the low color temperature side and the light-emitting element group on the high color temperature side. On the other hand, the total number of light-emitting elements does not necessarily have to be the same in the light-emitting element group on the low color temperature side and the light-emitting element group on the high color temperature side.

[0045] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0046] 1 light emitting device, 2 light source module, 3a, 3b power source, 4a, 4b light emitting element group, 5 control unit, 21 substrate, 22a, 22b positive electrodes, 23a, 23b negative electrodes, 41a, 42a first elements, 41b, 42b second elements, 43b third elements.

Claims

1. a first light-emitting element group including a first element that is a red light-emitting element and a second element that is a light-emitting element of a color different from the first element; a second light-emitting element group including the first element, the second element, and a third element that is a light-emitting element having a color different from that of the first element and the second element; Equipped with the first element and the second element of the first light-emitting element group are connected in series; the first element, the second element, and the third element of the second light-emitting element group are connected in series; Light emitting device.

2. The light emitting device according to claim 1 , wherein the second element is a lime light emitting element.

3. The light emitting device according to claim 1 , wherein the third element is a white light emitting element.

4. 3. The light emitting device according to claim 1, wherein a luminous flux ratio between the first element and the second element is 1:2.3-2.

6.

5. 4. The light emitting device according to claim 1, wherein a luminous flux ratio between the first element and the third element is 1:1.5-2.3.

Images