Light emitting device and lighting fixture

Abstract

To easily form a planar light source having a circular shape.SOLUTION: A light emitting device 111 includes: a plurality of light emitting elements 50; and a substrate 40. Each of the plurality of light emitting elements 50 emits light. Each light emitting element 50 is disposed on the substrate 40. Each of the plurality of light emitting elements 50 has a rectangular shape and a rectangular light emitting surface. The plurality of light emitting elements 50 includes a plurality of types of light emitting elements 51 and 52 having mutually different sizes. The plurality of light emitting elements 50 are arranged aligned inside a circular region R in the substrate 40. The plurality of light emitting elements 50 contains a plurality of outermost light emitting elements 50R disposed on the outermost side in a radial direction of the circular region R. The plurality of outermost light emitting elements 50R is arranged along a boundary R1 between the inside and the outside of the circular region R.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a light-emitting device and a lighting fixture.

Background Art

[0002] In the lighting device of Patent Document 1, the light emitted from the light source is distributed by a lens. A plurality of LEDs of the same size and different emission colors are regularly arranged so as to be arranged at the vertices of a lattice or a triangle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, there is a desire to arrange a plurality of light-emitting elements having a rectangular light-emitting surface to form a surface light source having a shape close to a circle.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a light-emitting device and a lighting fixture capable of easily forming a surface light source having a shape close to a circle.

Means for Solving the Problems

[0006] The light-emitting device according to the present invention includes a plurality of light-emitting elements and a substrate. Each of the plurality of light-emitting elements emits light. The light-emitting elements are arranged on the substrate. Each of the plurality of light-emitting elements has a rectangular shape and a rectangular light-emitting surface. The plurality of light-emitting elements include a plurality of types of light-emitting elements having different sizes from each other. The plurality of light-emitting elements are arranged side by side inside a circular region on the substrate. The plurality of light-emitting elements include a plurality of outermost light-emitting elements arranged on the outermost side in the radial direction of the circular region. The plurality of outermost light-emitting elements are arranged side by side along the boundary between the inside and the outside of the circular region.

[0007] In the light-emitting device according to the present invention, it is preferable that each of the plurality of types of light-emitting elements includes a first-color light-emitting element that emits light in a first color and a second-color light-emitting element that emits light in a second color different from the first color.

[0008] In the light-emitting device according to the present invention, it is preferable that the plurality of types of light-emitting elements include a first light-emitting element and a second light-emitting element smaller than the first light-emitting element. In the circular region, it is preferable that the second light-emitting element is arranged on the outer side in the radial direction than the first light-emitting element.

[0009] In the light-emitting device according to the present invention, it is preferable that each of the plurality of light-emitting elements is formed by a CSP (Chip Size Package).

[0010] In the light-emitting device according to the present invention, it is preferable that the distance between adjacent light-emitting elements is shorter than the length of one side of the second light-emitting element.

[0011] In the light-emitting device according to the present invention, it is preferable that the plurality of types of light-emitting elements further include a third light-emitting element having a size different from the size of the first light-emitting element and different from the size of the second light-emitting element.

[0012] The light-emitting device according to the present invention includes a light-emitting device and a power source that supplies power to the light-emitting device.

Effect of the Invention

[0013] According to the present invention, it becomes possible to easily form a surface light source having a circular shape.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and the description will not be repeated.

[0016] Referring to FIG. 1, the lighting fixture 200 according to this embodiment will be described. FIG. 1 is a view showing the lighting fixture 200 according to this embodiment. The lighting fixture 200 is attached to an attachment object such as a building, for example. The lighting fixture 200 is a spotlight, a downlight, or the like.

[0017] As shown in FIG. 1, the lighting fixture 200 includes a cylindrical lamp body 80 and a cylindrical frame body 103 that houses the lamp body 80 and fixes the lamp body 80 to the mounting position of the object to be mounted. The lamp body 80 includes a power source 70, a light-emitting device 111, and a lens 127. The power source 70 converts, for example, AC power supplied from an AC power source outside the lighting fixture 200 into DC power and supplies it to the light-emitting device 111. The light-emitting device 111 emits light when DC power is supplied from the power source 70. The lens 127 covers the light-emitting surface of the light-emitting device 111 and condenses or diffuses the light emitted from the light-emitting device 111.

[0018] Next, with reference to FIG. 2, the light-emitting device 111 according to the present embodiment will be described. FIG. 2 is a diagram showing the light-emitting device 111 according to the present embodiment.

[0019] The light-emitting device 111 includes a substrate 40 and a plurality of light-emitting elements 50. The plurality of light-emitting elements 50 are arranged side by side on the mounting surface of the substrate 40. In the present embodiment, the light-emitting element 50 is an LED (Light Emitting Diode) and emits light. The light-emitting element 50 has a rectangular shape and a rectangular light-emitting surface. The substrate 40 is a multilayer substrate in which a plurality of conductive layers and a plurality of insulating layers are alternately laminated. A mounting surface is provided on the surface of the substrate 40. In the present embodiment, the substrate 40 is circular along the cross-section of the lamp body 80 along the light-emitting surface, but the shape of the substrate 40 is not particularly limited. Also, the size of the substrate 40 is not particularly limited.

[0020] As an example, the light-emitting element 50 forms an LED chip having a rectangular shape, which is formed by further covering an LED and a phosphor layer with a package larger than the phosphor layer to form a single unit, and mounting a plurality of LED chips on the mounting surface of the substrate 40 and electrically connecting them to the conductive layer of the substrate 40, or is a COB (Chip on Board) type formed by covering a plurality of LEDs with one package.

[0021] Specifically, the SMD type light-emitting element 50 has a light-emitting surface corresponding to one LED. In the SMD type light-emitting element 50, a part of the package that does not transmit light is provided around the light-emitting surface. On the other hand, the COB type light-emitting element 50 has a light-emitting surface corresponding to a plurality of LEDs. In the COB type light-emitting element 50, a part of the package that does not transmit light is provided surrounding the light-emitting surface. Specifically, a dam-shaped structure that contributes to resin molding for encapsulating the LED chip is provided.

[0022] [Light-emitting element arrangement pattern 1] Next, with reference to FIGS. 2 and 3, the arrangement of the light-emitting elements 50 on the substrate 40 will be described. FIG. 3 is a diagram showing details of the arrangement of the light-emitting elements 50 on the substrate 40. Note that FIG. 3 is a representative example of the arrangement of the light-emitting elements 50 and is not necessarily the actual arrangement.

[0023] As shown in FIG. 2, the plurality of light-emitting elements 50 include light-emitting elements 51 and light-emitting elements 52 that are different in size from each other. The light-emitting elements 51 and the light-emitting elements 52 are an example of a plurality of types of light-emitting elements. For example, the light-emitting element 52 is smaller than the light-emitting element 51. That is, the light-emitting element 52 has a smaller area of the light-emitting portion than the light-emitting element 51. Specifically, the length of one side of the light-emitting element 52 (see FIG. 3) is shorter than the length of one side of the light-emitting element 51 (see FIG. 3). The light-emitting element 51 is an example of a first light-emitting element. The light-emitting element 52 is an example of a second light-emitting element. In FIG. 2, for the sake of clarity of the drawing, among the plurality of light-emitting elements 51 and the plurality of light-emitting elements 52, some of the light-emitting elements 51 and the light-emitting elements 52 are typically labeled.

[0024] The plurality of light-emitting elements 50 are arranged side by side in a region R inside a circular boundary R1 shown by a dashed line in FIG. 2 on the mounting surface of the substrate 40. In other words, in the region R on the mounting surface of the substrate 40, the plurality of light-emitting elements 51 and the plurality of light-emitting elements 52 are randomly spread without a predetermined regularity. For example, a certain light-emitting element 51 arranged in the region R may be adjacent to a light-emitting element 51 or may be adjacent to a light-emitting element 52. The ratio of the region R to the mounting surface of the substrate 40 is not particularly limited.

[0025] Therefore, the plurality of light-emitting elements 50 includes a plurality of outermost light-emitting elements 50R arranged most outward in the radial direction of the region R. The outermost light-emitting elements 50R are arranged side by side along the boundary R1.

[0026] If only the light-emitting elements 52 smaller than the light-emitting element 51 are arranged in the region R, while it is easy to arrange the outermost light-emitting elements 50R along the boundary R1, many light-emitting elements 52 are required to cover the region R. On the other hand, if only the light-emitting elements 51 are arranged in the region R, the number of light-emitting elements 51 required to cover the region R decreases compared to the case of the light-emitting elements 52, while the gap generated between the outermost light-emitting element 50R and the boundary R1 becomes larger. That is, the light-emitting element 51 is more difficult to arrange along the boundary R1 compared to the light-emitting element 52, and it is difficult to make the light-emitting shape of the light-emitting device 111 closer to a circular shape even if the region R is covered.

[0027] On the contrary, by arranging the light-emitting element 51 and the light-emitting element 52 having rectangular light-emitting surfaces with different sizes inside the region R and arranging the outermost light-emitting elements 50R along the circular boundary R1, for example, the light-emitting element 52 is arranged in the gap generated between the outermost light-emitting element 50R and the boundary R1, and the gap generated in the region R is easily filled. Therefore, the light-emitting shape of the light-emitting device 111 can be made closer to a circular shape with a small number of components. Therefore, according to the light-emitting device 111 of the present embodiment, it is easy to form a surface light source having a circular shape.

[0028] Also, as shown in FIGS. 2 and 3, the plurality of light-emitting elements 51 includes a light-emitting element 51A that emits light in a first color and a light-emitting element 51B that emits light in a second color different from the first color. The plurality of light-emitting elements 52 includes a light-emitting element 52A that emits light in the first color and a light-emitting element 52B that emits light in the second color. The first color and the second color have different correlated color temperatures (hereinafter simply referred to as "color temperatures"). As an example, the first color is a warm color (about 2800 K to 3500 K). The second color is a cool color (about 5700 K to 7100 K). In FIG. 2, the difference in color temperature is represented by hatching. Note that the color temperature of the first color and the color temperature of the second color are not particularly limited to the above.

[0029] The light of the first color emitted from the plurality of light-emitting elements 51A and the plurality of light-emitting elements 52A and the light of the second color emitted from the plurality of light-emitting elements 51B and the plurality of light-emitting elements 52B are mixed by the condensing or diffusing by the lens 127 when passing through the lens 127. By mixing the first color and the second color, light including a desired spectrum is more easily generated than the emitted light of a light-emitting element that emits light in a single color.

[0030] Also, in the present embodiment, color adjustment for adjusting the emission color of the light-emitting device 111 may be performed by adjusting the brightness of the light-emitting element 52A and the light-emitting element 52B with respect to each other to adjust the mixing ratio of the light of the first color and the light of the second color. The color adjustment is performed, for example, by a control unit (not shown) that controls the light emission of the light-emitting element 52A and the light-emitting element 52B based on a color adjustment control signal input from an illumination control device such as a light controller, and the amount of current flowing through the light-emitting element 52A and the light-emitting element 52B is determined.

[0031] Specifically, the length of one side of the light-emitting element 51A is the length L11A. The length of the side intersecting one side of the light-emitting element 51A is the length L12A. In other words, the size of the light-emitting element 51A can be expressed as length L11A × length L12A. Note that the length L11A and the length L12A may be the same or different from each other.

[0032] Typically, the light-emitting element 50 is formed as a CSP (Chip Size Package) that covers the phosphor layer with a package of the same size as the phosphor layer. Hereinafter, the CSP-type light-emitting element 50 will be described as an example. When the light-emitting element 51A is of the CSP type, the size of the light-emitting surface is substantially the same as the size of the light-emitting element 51A.

[0033] When the light-emitting element 50 is formed as a CSP, the ratio of the light-emitting surface to the package increases. As a result, the ratio of the light-emitting surfaces of the plurality of light-emitting elements 50 to the region R increases. Therefore, a circular surface light source with uniform light brightness is easily generated.

[0034] Similarly, the length of one side of the light-emitting element 51B is length L11B. The length of the side intersecting one side of the light-emitting element 51B is length L12B. The length L11B is the same as the length L11A. The length L12B is the same as the length L12A. The lengths L11A, L12A, L11B, and L12B are not particularly limited in numerical value, but may be longer or shorter than the radius of the region R.

[0035] On the other hand, the length of one side of the light-emitting element 52A is length L21A. The length of the side intersecting one side of the light-emitting element 52A is length L22A. The length of one side of the light-emitting element 52B is length L21B. The length of the side intersecting one side of the light-emitting element 52B is length L22B. The length L21B is the same as the length L21A. The length L22B is the same as the length L22A. At least one of the lengths L21A and L22A is shorter than the lengths L11A and L12A, respectively. At least one of the lengths L21B and L22B is shorter than the lengths L11B and L12B, respectively. The lengths L21A, L22A, L21B, and L22B are not particularly limited in numerical value, but are shorter than the radius of the region R.

[0036] The light-emitting elements 51A, 51B, 52A, and 52B are arranged in the region R at a predetermined interval from each other. As an example, the adjacent light-emitting elements 51A and 51B are arranged at an interval d1 from each other. The adjacent light-emitting elements 51A and 52B are arranged at an interval d2 from each other. The adjacent light-emitting elements 52A and 52B are arranged at an interval d3 from each other. The interval d1, the interval d2, and the interval d3 may be the same or different from each other.

[0037] The interval d1, the interval d2, and the interval d3 are each shorter than the length of one side of the light-emitting element 52A (light-emitting element 52B). Specifically, the interval d1, the interval d2, and the interval d3 are shorter than the shorter one of the length L21A and the length L22A.

[0038] As a result, the density of the light-emitting elements 50 in the region R increases. As a result, the ratio of the light-emitting surfaces of the plurality of light-emitting elements 50 to the region R increases. Therefore, it becomes easier to generate a circular surface light source with uniform light brightness.

[0039] [Light-emitting element arrangement pattern 2] Next, with reference to FIG. 4, another example of the arrangement of the light-emitting elements 50 on the substrate 40 will be described. FIG. 4 is a diagram showing another example of the arrangement of the light-emitting elements 50 on the substrate 40.

[0040] A light-emitting device 111A, which is a modified example of the light-emitting device 111 according to the present embodiment, is the same as the light-emitting device 111 except that the arrangement of the light-emitting elements 50 on the substrate 40 is different from that of the light-emitting device 111.

[0041] As shown in FIG. 4, in the region R of the substrate 40 in the light-emitting device 111A, the light-emitting element 52 is arranged outside the light-emitting element 51 in the radial direction of the region R. Specifically, the light-emitting element 51 is arranged on the center side of the region R. The light-emitting element 52 is arranged on the outer peripheral (boundary t) side of the region R.

[0042] The light-emitting element 52 smaller than the light-emitting element 51 is easier to arrange along the curve of the boundary R1 than the light-emitting element 51. Therefore, the arrangement of the outermost light-emitting element 50R can be made closer to a circular shape.

[0043] [Light-emitting element arrangement pattern 3] Next, with reference to FIG. 5, another example of the arrangement of the light-emitting elements 50 on the substrate 40 will be described. FIG. 5 is a diagram showing another example of the arrangement of the light-emitting elements 50 on the substrate 40.

[0044] A light-emitting device 111B, which is a modified example of the light-emitting device 111 according to the present embodiment, is the same as the light-emitting device 111 except that the arrangement of the light-emitting elements 50 on the substrate 40 is different from that of the light-emitting device 111.

[0045] As shown in FIG. 5, in the light-emitting device 111B, the light-emitting element 50 further includes a light-emitting element 53 having a size different from that of the light-emitting element 51 and different from that of the light-emitting element 52. For example, the light-emitting element 53 is larger than the light-emitting element 51. In the present embodiment, the light-emitting element 53 includes a light-emitting element 53A that emits light in the first color and a light-emitting element 53B that emits light in the second color.

[0046] In this way, by using light-emitting elements 50 of three types of sizes, the shape of the light emission of the light-emitting device 111 can be made closer to a circular shape with a smaller number of parts.

[0047] For example, on the substrate 40 in the light-emitting device 111B, the light-emitting element 53A and the light-emitting element 53B are arranged on the center side of the region R. The plurality of light-emitting elements 52 are arranged on the outer peripheral (boundary R1) side of the light-emitting element 53 in the region R. The plurality of light-emitting elements 51 are arranged on the outer peripheral (boundary R1) side of the light-emitting element 52 in the region R.

[0048] Note that, in the light-emitting device 111B, only one of the light-emitting elements 53A and 53B may be arranged on the substrate 40. Further, the light-emitting elements 51, 52, and 53 are not limited to the arrangement shown in FIG. 5, and may be arranged randomly without a predetermined regularity as shown in FIG. 2, for example.

[0049] Further, the light-emitting element 53 may be smaller than the light-emitting element 52, or may be larger than the light-emitting element 52 and smaller than the light-emitting element 51.

[0050] In the present embodiment, the light-emitting device 111 is configured to be provided in a spotlight and a downlight. However, the present invention is not limited to this, and the light-emitting device 111 may be provided in, for example, a headlight of a vehicle.

[0051] In the present embodiment, the light-emitting element 50 is configured to emit light in the first color or the second color. However, the light-emitting element 50 may include a light-emitting element that emits light in a third color different from the first color and the second color.

[0052] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. Further, the plurality of components disclosed in the above embodiments can be modified as appropriate. For example, a component among all the components shown in one embodiment may be added to the components of another embodiment, or some of the components among all the components shown in one embodiment may be deleted from the embodiment.

[0053] Further, the drawings schematically show each component mainly for easy understanding of the invention, and the thickness, length, number, interval, etc. of each illustrated component may be different from the actual ones for convenience of drawing creation. Also, the configuration of each component shown in the above embodiment is an example and is not particularly limited, and it goes without saying that various changes can be made without substantially departing from the effects of the present invention.

Industrial Applicability

[0054] The present invention can be used in the fields of light-emitting devices and lighting fixtures.

Explanation of Reference Numerals

[0055] 40: Substrate 50: Light-emitting element 50R: Outermost light-emitting element 51, 51A, 51B: Light-emitting element (first light-emitting element) 52, 52A, 52B: Light-emitting element (second light-emitting element) 53, 53A, 53B: Light-emitting element (third light-emitting element) 70: Power supply 111, 111A, 111B: Light-emitting device 200: Lighting fixture R: Region R1: Boundary d-1, d-2, d-3: Spacing

Claims

1. A plurality of light-emitting elements each emitting light, a substrate on which the light-emitting elements are disposed, and comprising: each of the plurality of light-emitting elements has a rectangular shape and a rectangular light-emitting surface, the plurality of light-emitting elements includes a plurality of types of light-emitting elements having different sizes from each other, the plurality of light-emitting elements are arranged side by side inside a circular region on the substrate, the plurality of light-emitting elements includes a plurality of outermost light-emitting elements arranged outermost in the radial direction of the circular region, the plurality of outermost light-emitting elements are arranged side by side along the boundary between the inside and the outside of the circular region, a light-emitting device.

2. The light-emitting device according to claim 1, wherein each of the plurality of types of light-emitting elements includes a first-color light-emitting element that emits light in a first color and a second-color light-emitting element that emits light in a second color different from the first color.

3. The plurality of types of light-emitting elements include a first light-emitting element, and a second light-emitting element smaller than the first light-emitting element, and comprising: In the circular region, the second light-emitting element is arranged outside the first light-emitting element in the radial direction. The light-emitting device according to claim 1 or claim 2.

4. The light-emitting device according to claim 1 or claim 2, wherein each of the plurality of light-emitting elements is formed by a CSP (Chip Size Package).

5. The light-emitting device according to claim 3, wherein the distance between adjacent light-emitting elements is shorter than the length of one side of the second light-emitting element.

6. The light-emitting device according to claim 3, wherein the plurality of types of light-emitting elements further includes a third light-emitting element having a size different from the size of the first light-emitting element and different from the size of the second light-emitting element.

7. A lighting fixture comprising the light-emitting device according to claim 1 or claim 2, and a power supply for supplying power to the light-emitting device. ​

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