Lighting fixtures

Abstract

To provide a luminaire that can efficiently extract light emitted by a light emitting module, to the outside.SOLUTION: A luminaire 100 comprises: a light emitting module 10 comprising a plurality of light emitting elements 21 for emitting light frontward; an optical member 200 comprising a plurality of lenses 210, and covering the plurality of light emitting elements 21; and an illuminating cover 140 having translucency, and arranged in front of the optical member 200. Each of the plurality of lenses 210 is arranged opposite to two or more light emitting elements 21 out of the plurality of light emitting elements 21, and comprises two or more concave parts 221 forming an inner surface on which light from the two or more light emitting elements 21 is incident. The two or more concave parts 221 correspond to the two or more light emitting elements 21 on a one-to-one basis. Each of the two or more concave parts 221 is arranged opposite to one light emitting element 21 out of the two or more light emitting elements 21.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a lighting fixture including a plurality of light-emitting elements arranged on a substrate.

Background Art

[0002] Conventionally, a ceiling light, which is a lighting fixture arranged on a ceiling, is known. For example, the lighting fixture disclosed in Patent Document 1 includes a light-emitting module having a plurality of LED light sources, a lens cover covering the plurality of LED light sources, and a diffusion cover covering the lens cover. The lens cover has a plurality of lenses that control the light distribution of the light emitted from each of the plurality of LED light sources.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional lighting fixture, one lens is arranged for each of the plurality of LED light sources so as to control the light distribution of the light emitted from each of the plurality of LED light sources mounted on the substrate. However, since the range in which the plurality of LED light sources can be arranged on the substrate is limited, for example, when the number of LED light sources is increased to obtain brighter illumination light, the density of the LED light sources on the substrate is improved, and as a result, the overlapping portion between adjacent lenses becomes larger. As a result, there is a problem that it becomes difficult to improve the light extraction efficiency of each lens.

[0005] The present invention has been newly made by the inventors of the present application paying attention to the above problems, and an object thereof is to provide a lighting fixture capable of efficiently extracting the light emitted from a light-emitting module to the outside.

Means for Solving the Problems

[0006] A lighting fixture according to one aspect of the present invention comprises a light-emitting module having a plurality of light-emitting elements that emit light forward, an optical member having a plurality of lenses and covering the plurality of light-emitting elements, and a light-transmitting lighting cover disposed in front of the optical member, wherein each of the plurality of lenses is disposed opposite to two or more of the plurality of light-emitting elements, and has two or more recesses that form an inner surface into which light from the two or more light-emitting elements enters, with two or more recesses corresponding one-to-one with the two or more light-emitting elements, and each of the two or more recesses is disposed opposite to one of the two or more light-emitting elements. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a lighting fixture that can efficiently extract light emitted by a light-emitting module to the outside. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing the first external appearance of a lighting fixture according to an embodiment. [Figure 2] Figure 2 is a second exploded perspective view of the lighting fixture according to the embodiment. [Figure 3] Figure 3 is a plan view of a light-emitting module according to an embodiment. [Figure 4A] Figure 4A is a plan view of an optical component according to an embodiment. [Figure 4B] Figure 4B shows the back surface of the optical component according to the embodiment. [Figure 5] Figure 5 is a perspective view of the lens according to the embodiment, as seen from the side of the incident surface. [Figure 6] Figure 6 is a cross-sectional view of a lens according to an embodiment. [Figure 7] Figure 7 is a cross-sectional view of a lens according to an embodiment. [Figure 8A] Figure 8A shows the light distribution curve of light emitted from a lens according to the embodiment. [Figure 8B] Figure 8B shows the light distribution curve of light emitted from a lens according to the embodiment. [Figure 8C] Figure 8C shows the light distribution curve of light emitted from a lens according to the embodiment. [Figure 9A] Figure 9A is a plan view showing the positional relationship between the light-emitting element group and the lens according to the embodiment. [Figure 9B] Figure 9B is a side view of the lens according to the embodiment. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are all specific examples of the present invention. Therefore, the numerical values, components, arrangement and connection configurations of components, as well as the processes and their sequences shown in the following embodiments, are examples only and are not intended to limit the present invention. Accordingly, any components in the following embodiments that are not described in the independent claims representing the highest-level concept of the present invention will be described as optional components.

[0010] Each figure is a schematic diagram and not necessarily a strictly accurate representation. In each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations are omitted or simplified. In each figure, the X, Y, and Z axes represent the three axes of a three-dimensional Cartesian coordinate system. In this embodiment, the Z-axis direction is defined as the vertical direction (up and down direction), and the direction perpendicular to the Z-axis (parallel to the XY plane) is defined as the horizontal direction. Depending on the usage, the Z-axis direction may not be vertical, but for the sake of explanation, the Z-axis direction will be described as vertical below.

[0011] In the following description, for example, the positive X-axis direction indicates the arrow direction of the X-axis, and the negative X-axis direction indicates the direction opposite to the positive X-axis direction. The same applies to the Y-axis direction and the Z-axis direction. When simply referring to the "X-axis direction", it means a two-way direction parallel to the X-axis or either one of the directions. The same applies to terms related to the Y-axis and Z-axis.

[0012] Expressions indicating relative directions or postures such as parallel and orthogonal strictly include cases where they are not exactly in that direction or posture. For example, when two directions are orthogonal, it not only means that the two directions are completely orthogonal, but also means that they are substantially orthogonal, that is, for example, including a difference of about a few percent.

[0013] (Embodiment) [1. Overall Structure of Lighting Fixture] First, while referring to FIGS. 1 to 3, the overall structure of the lighting fixture 100 according to the embodiment will be described. FIG. 1 is a first exploded perspective view of the lighting fixture 100 according to the embodiment. FIG. 2 is a second exploded perspective view of the lighting fixture 100 according to the embodiment. The downward direction (negative Z-axis direction) in FIGS. 1 and 2 corresponds to the direction of the ceiling (not shown). That is, the lighting fixture 100 in FIGS. 1 and 2 is illustrated in an upside-down posture compared to normal use. This is the same for FIGS. 6, 7, and 9B described later. FIG. 3 is a view (plan view) when viewed from the positive Z-axis direction (hereinafter also referred to as "front") of the light-emitting module 10 according to the embodiment.

[0014] As shown in Fig. 1, the lighting fixture 100 of the present embodiment is, for example, a ceiling light attached to the ceiling of a building. The lighting fixture 100 according to the present embodiment includes a fixture body 110, a light-emitting module 10 attached to the fixture body 110, and an optical member 200. As shown in Fig. 2, the light-emitting module 10 has a substrate 11 and a plurality of light-emitting elements 21 arranged on a main surface 11a (a surface in the +Z-axis direction) of the substrate 11. In the present embodiment, a plurality of circuit components (not shown) are further arranged on the main surface 11a of the substrate 11, and a power supply circuit is constituted by these plurality of circuit components. The power supply circuit is covered by a circuit cover 150. The circuit cover 150 is formed of a material with high heat resistance such as metal. The light-emitting module 10 emits light by the power supplied from the power supply circuit arranged on the substrate 11. The lighting fixture 100 does not necessarily need to include a power supply circuit, and may receive power supply for the light emission of the light-emitting module 10 via an electric wire from a power supply circuit arranged in the ceiling space, for example. Thereby, for example, the lighting fixture 100 can be miniaturized or lightened.

[0015] The optical member 200 is a member that covers the light-emitting module 10 and transmits the light from the light-emitting module 10. The light-emitting module 10 includes a plurality of lenses 210. Each of the plurality of lenses 210 is arranged so as to cover two or more light-emitting elements 21 included in the light-emitting module 10. That is, one lens 210 faces two or more light-emitting elements 21 in the Z-axis direction. That is, in the present embodiment, the lens 210 and the light-emitting element 21 are associated with each other in a one-to-many relationship. The lens 210 controls the light distribution of two or more light-emitting elements 21 arranged to face each other in the Z-axis direction.

[0016] The lighting fixture 100 according to the present embodiment further includes a reflective sheet 40 arranged along the light-emitting module 10. The reflective sheet 40 is, for example, a sheet-like member formed of resin, and reflects the light directly and indirectly directed from the light-emitting element 21 toward the reflective sheet 40. As shown in Fig. 2, a plurality of through holes 41 for exposing each of the plurality of light-emitting elements 21 to the side of the optical member 200 are formed in the reflective sheet 40.

[0017] [1-1. Main body of the device] As shown in Figure 1, the fixture body 110 is a disc-shaped member made from sheet metal such as an aluminum plate or a steel plate. The surface of the fixture body 110 on which the light-emitting module 10 etc. are arranged is coated with, for example, a white paint with high light reflectivity or coated with a reflective metallic material.

[0018] A circular opening 119 is formed in the center of the fixture body 110. The opening 119 has a structure that allows a fixture mounting member (not shown) to be attached, and the fixture body 110 can be detachably attached to the ceiling via the fixture mounting member. In other words, the fixture body 110 may be detachably attached to the ceiling via the fixture mounting member.

[0019] In the fixture body 110, a mounting surface 112 is formed around the opening 119. When the mounting surface 112 and the light-emitting module 10 are attached to the fixture body 110, the back surface of the substrate 11 of the mounting surface 112 is in contact with each other. As a result, the heat emitted by the light-emitting module 10 is efficiently dissipated to the outside through the fixture body 110.

[0020] [1-2. Light-emitting module] As shown in Figure 3, the light-emitting module 10 comprises a substrate 11 and a plurality of light-emitting elements 21 arranged on the main surface 11a of the substrate 11, which is the front-facing surface. The substrate 11 has a polygonal shape when viewed from the front (hereinafter also referred to as "plan view"), and a substantially circular opening 12 is formed in the center. The substrate 11 can be described, for example, as a rectangle with the tips of the four corners cut off. The substrate 11 is a so-called printed circuit board in which metal wiring is patterned. In this embodiment, the substrate 11 is a resin substrate in which the conductor pattern (metal wiring) is exposed on at least the main surface 11a, of which the main surface 11a and the back surface (the surface in the negative Z-axis direction) are used. Examples of such substrates include glass epoxy substrates and composite substrate epoxy resin substrates (CEM-3).

[0021] Each of the multiple light-emitting elements 21 in this embodiment is an individually packaged SMD (Surface Mount Device) type LED element (LED light source). That is, each of the multiple light-emitting elements 21 comprises a white container (package) made of resin or ceramic, an LED chip (bare chip) placed inside the container, and a sealing member that seals the LED chip. Each of the multiple light-emitting elements 21 primarily emits light forward (in the Z-axis positive direction). In other words, in this embodiment, the lighting fixture 100 is mounted on the ceiling or the like in a position where the optical axis of the light-emitting elements 21 is facing in the Z-axis positive direction.

[0022] Each of these multiple light-emitting elements 21 belongs to one of several light-emitting element groups 20, as shown in Figure 3, for example. A light-emitting element group 20 is a light source unit consisting of three or four light-emitting elements 21 that are relatively close to each other. In this embodiment, when distinguishing between a light-emitting element group 20 consisting of four light-emitting elements 21 and a light-emitting element group 20 consisting of three light-emitting elements 21, the former is referred to as light-emitting element group 20A and the latter as light-emitting element group 20B. In this embodiment, 198 light-emitting elements 21 are arranged on the substrate 11, and these 198 light-emitting elements 21 constitute 48 light-emitting element groups 20A and 2 light-emitting element groups 20B.

[0023] More specifically, in this embodiment, the multiple light-emitting element groups 20A include two types of light-emitting element groups 20A distinguished by the arrangement layout of four light-emitting elements 21. Specifically, the multiple light-emitting element groups 20A are distinguished into light-emitting element group 20A1 and light-emitting element group 20A2. Light-emitting element group 20A1 is composed of four light-emitting elements 21 arranged in a matrix along the X-axis and Y-axis. Light-emitting element group 20A2 has an arrangement layout obtained by rotating light-emitting element group 20A1 by 45° around the Z-axis. Thus, differentiating the arrangement layout of N light-emitting elements 21 included in one light-emitting element group 20 from the arrangement layout of N light-emitting elements 21 included in another light-emitting element group 20 contributes to reducing light unevenness in the illumination light emitted by the lighting fixture 100. However, the relative positional relationship between each of the light-emitting element groups 20A1 and 20A2 and the lens 210, which will be described later, is common to both light-emitting element groups 20A1 and 20A2. Therefore, in the following explanation, when describing the light-emitting element group 20A, we will use the light-emitting element group 20A1 as an example.

[0024] Thus, the light-emitting module 10, which has multiple light-emitting element groups 20, is covered by an optical member 200, which has multiple lenses 210 that correspond one-to-one with the multiple light-emitting element groups 20. The configuration of the optical member 200 and its surroundings will be described later with reference to Figures 4A to 9B.

[0025] [1-3. Lighting cover 140] The lighting cover 140 is a component that covers the side of the fixture body 110 to which the light-emitting module 10 and the like are attached, and is made of a light-transmitting resin. The lighting cover 140 is made of, for example, a milky white resin and can diffuse the light from each light-emitting element 21 and emit it to the outside. In this embodiment, the lighting cover 140 is detachably attached to the fixture body 110. The lighting cover 140 may also be called, for example, a "diffusion cover" or a "globe".

[0026] [2. Configuration of the optical component 200 and its surrounding area] Next, the configuration of the optical member 200 and its surrounding area according to this embodiment will be described with reference to Figures 4A to 9B, in addition to Figures 1 to 3 described above.

[0027] Figure 4A is a plan view of the optical member 200 according to the embodiment. In Figure 4A, to make it easier to distinguish between lenses 210A, 210B, and 210C, dark dots are marked on lens 210B and light dots are marked on lens 210C. Figure 4B is a view of the back surface 201b of the optical member 200 according to the embodiment. In Figure 4B, the optical member 200 shown in Figure 4A is shown rotated 180° around the X axis. Figure 5 is a perspective view of lens 210A according to the embodiment as seen from the incident surface 220 side. Figure 6 is a cross-sectional view of lens 210A according to the embodiment. In Figure 6, the cross-section along line VI-VI shown in Figures 4A, 4B, and 5 is simply illustrated. Figure 7 is a cross-sectional view of lens 210C according to the embodiment. In Figure 7, the cross-section along line VII-VII shown in Figures 4A and 4B is simply illustrated.

[0028] Figure 8A shows the light distribution curve of light emitted from lens 210A. Figure 8B shows the light distribution curve of light emitted from lens 210B. Figure 8C shows the light distribution curve of light emitted from lens 210C. Figure 9A is a plan view showing the positional relationship between the light-emitting element group 20A and lens 210A. In Figure 9A, in order to clearly show this positional relationship, the outlines of the four recesses 221 and the four light-emitting elements 21 of lens 210A are shown with solid lines in a plan view. Figure 9B is a side view of lens 210A according to the embodiment (viewed from the direction of the positive X-axis).

[0029] As shown in Figures 1, 2, and 4A, the optical member 200 is positioned to cover the light-emitting module 10. More specifically, the optical member 200 covers the area of ​​the light-emitting module 10 in which at least a plurality of light-emitting elements 21 are located. The optical member 200 is formed using a translucent resin material, such as transparent acrylic resin. In a plan view, the optical member 200 has a circular outer shape with a hole (opening 209) in the center, that is, it has a shape generally called a donut shape.

[0030] As shown in Figure 4A, the optical member 200 comprises a flat main body portion 201 and a plurality of lenses 210 protruding forward from the front surface 201a of the main body portion 201. The plurality of lenses 210 are distinguished into lenses 210A and 210C that face the light-emitting element group 20A consisting of four light-emitting elements 21, and lenses 210B that face the light-emitting element group 20B consisting of three light-emitting elements 21. Although both lenses 210A and 210B are positioned facing the light-emitting element group 20A, they have different optical characteristics due to differences in shape and outer diameter in plan view. These optical characteristics will be described later.

[0031] In this embodiment, the optical member 200 is provided with 50 lenses 210 corresponding to 50 light-emitting element groups 20. These 50 lenses 210 are composed of 40 lenses 210A, 8 lenses 210C, and 2 lenses 210B.

[0032] Lenses 210A to 210C each have recesses 221 (see Figures 4B and 5) at positions opposite to each of the two or more light-emitting elements 21 that are arranged opposite each other in the Z-axis direction. The inner surfaces of these recesses 221 form an incident surface 220 into which light from the plurality of light-emitting elements 21 (light-emitting element group 20) is incident.

[0033] That is, lenses 210A and 210C, which are positioned opposite the light-emitting element group 20A, have four recesses 221. Lens 210B, which is positioned opposite the light-emitting element group 20B, has three recesses 221. For example, as shown in Figure 5, lens 210A has an incident surface 220 formed by the combination of four recesses 221. Similarly, lens 210C also has an incident surface 220 formed by the combination of four recesses 221, and lens 210B has an incident surface 220 formed by the combination of three recesses 221. Thus, in this embodiment, lens 210 has two or more recesses 221 inside that correspond one-to-one with two or more light-emitting elements 21, and has one light-emitting surface 211 having a rotationally symmetric three-dimensional shape. In other words, as shown in Figures 1, 2, and 4A, the optical member 200 appears to have 50 lenses 210. Each of these 50 lenses 210 is positioned to cover two or more light-emitting elements 21, as shown in Figures 3 to 7 and Figure 9A. This allows each of the 50 lenses 210 to impart an optical effect (such as widening the beam angle) to the light from two or more light-emitting elements 21, while keeping the overlap with other lenses 210 relatively small.

[0034] The lighting fixture 100 according to this embodiment, configured as described above, can be described as follows, for example.

[0035] (1) The lighting fixture 100 according to this embodiment comprises a light-emitting module 10 having a plurality of light-emitting elements 21 that emit light forward, an optical member 200 having a plurality of lenses 210 and covering the plurality of light-emitting elements 21, and a light-transmitting lighting cover 140 positioned in front of the optical member 200. Each of the plurality of lenses 210 is positioned opposite two or more of the plurality of light-emitting elements 21 and has two or more recesses 221 that form an inner surface into which light from the two or more light-emitting elements 21 enters. The two or more recesses 221 correspond one-to-one with the two or more light-emitting elements 21. Each of the two or more recesses 221 is positioned opposite one of the two or more light-emitting elements 21.

[0036] In this configuration, unlike the case where one lens is placed for each of the multiple light-emitting elements 21, the light from two or more light-emitting elements 21 is controlled by a single lens 210. Even in this case, the lens 210 has one recess 221 facing one of the light-emitting elements 21 (see Figures 4B to 7). This ensures appropriate light distribution control for each of the two or more light-emitting elements 21. Furthermore, since the light distribution control for two or more light-emitting elements 21 is performed by a single lens 210, even if the number of light-emitting elements 21 in the light-emitting module 10 is relatively large, the increase in the number of lenses 210 that the optical member 200 needs to have is suppressed. For example, in this embodiment, 50 lenses 210 are placed for 198 light-emitting elements 21. As a result, compared to the case where 198 lenses are placed for 198 light-emitting elements 21, the overlap between the lens 210 in this embodiment and other adjacent lenses 210 is smaller. Therefore, the loss of optical effect from each of the multiple lenses 210 due to this overlap is suppressed.

[0037] An example of the optical characteristics of lenses 210A to 210C according to this embodiment will be explained using Figures 8A to 8C. Figure 8A corresponds to lens 210A, Figure 8B corresponds to lens 210B, and Figure 8C corresponds to lens 210C. Figures 8A and 8C show the optical distribution curves in two planes that are parallel to the Z-axis and orthogonal to each other. Figure 8B shows the optical distribution curves in three planes that are parallel to the Z-axis and rotated by 45° around the Z-axis.

[0038] As shown in Figures 8A to 8C, the light emitted from lenses 210A, 210B, and 210C travels diagonally forward. As a result, the light emitted from the multiple lenses 210, which are arranged in a relatively narrow area, spreads to almost the entire (or entire) front surface of the illumination cover 140 (see Figures 1 and 2). This makes the front surface of the illumination cover 140 appear to be continuously brightly lit. In other words, unevenness in the illumination light emitted from the lighting fixture 100 is reduced.

[0039] More specifically, the multiple light-emitting elements 21 and the multiple lenses 210 are not positioned in the center of the illumination cover 140 in a plan view, as shown in Figure 2, for example. Therefore, the center of the illumination cover 140 may appear darker than other parts. In this regard, in this embodiment, of the lenses 210A, 210B, and 210C, lens 210C is mainly configured to irradiate more light toward the center of the illumination cover 140. More specifically, as shown in Figures 6 and 7, lens 210C has a smaller outer diameter than lens 210A, and its height (width in the Z-axis direction) from the front surface 201a (see Figure 4A) of the main body 201 of the optical member 200 is greater than that of lens 210A. Lens 210C configured in this way can irradiate more light forward than lenses 210A and 210B, as shown in Figure 8C. In other words, while the peaks of the light distribution curves of lenses 210A and 210B are greater than 60°, the peak of the light distribution curve of lens 210C is approximately 50°. Lens 210C, which has such optical characteristics, is positioned close to the center of the illumination cover 140 in a plan view, as shown in Figure 4A. This allows light to efficiently enter the center of the illumination cover 140. Furthermore, lenses 210A and 210B, which emit wider-angle illumination light, efficiently enter parts of the illumination cover 140 other than the center. As a result, when the illumination fixture 100 is viewed from a distance, light unevenness (luminance unevenness) on the front surface of the illumination cover 140 is suppressed. In addition, since there is relatively little overlap between adjacent lenses 210 that provide such optical effects, the light with the characteristics shown in Figures 8A to 8C is efficiently output from each lens 210.

[0040] Furthermore, even if multiple lenses are arranged in a one-to-one correspondence with multiple light-emitting elements 21, reducing the size of each lens can reduce the overlap between adjacent lenses. However, in this case, each lens loses at least some of its functions, such as light distribution control. Therefore, miniaturizing lenses to reduce overlap is not desirable. Also, even if, for example, one lens 210 is arranged for four light-emitting elements 21, if the area of ​​the lens 210 in plan view is four times the area of ​​the lens arranged for one light-emitting element 21 (hereinafter referred to as "lens X"), it will be difficult to reduce the overlap between adjacent lenses 210. In this regard, for example, the outer diameter of lens 210A having the optical characteristics shown in Figure 8A is, for example, 25 mm, and the outer diameter of lens X to obtain similar optical characteristics is, for example, about 16 mm. In other words, when comparing lens 210A to lens X, lens 210A controls the light distribution of four times the number of light-emitting elements 21 as lens X, while its area in plan view is approximately 2.4 times that of lens X. Therefore, without changing the area on the substrate 11 where light-emitting elements 21 can be placed and the number of light-emitting elements 21, when comparing the case where multiple lenses 210A are placed with the case where multiple lenses X are placed, the overlap between adjacent lenses 210A is smaller when multiple lenses 210A are placed.

[0041] As described above, in this embodiment, multiple light-emitting elements 21 are concentrated within a relatively narrow range, and the light distribution control of these multiple light-emitting elements 21 (light-emitting element group 20) is performed by a single lens 210. Therefore, it is conceivable to increase the number of light-emitting elements 21 arranged on the substrate 11 (see Figure 3) by further increasing the density of two or more light-emitting elements 21 included in the light-emitting element group 20. However, if the spacing between adjacent light-emitting elements 21 in the light-emitting element group 20 is made excessively small, a problem may arise in which the light distribution control for each of these light-emitting elements 21 cannot be properly performed. Therefore, the inventors of this application have diligently studied the size of the light-emitting elements 21 and the distance between them, and have found conditions regarding the size of the light-emitting elements 21 that enable proper light distribution control. This will be explained in detail using lens 210A.

[0042] (2) In the lighting fixture 100 described in (1) above, L1 is the length of one side of each of the multiple light-emitting elements 21 which are rectangular (more specifically square) in plan view, and R1 is the distance between the center of the lens 210A (lens center 210Aa) and the center of each of the multiple light-emitting elements 21 (element center 21c) (see Figure 9A). In this case, it is preferable that L1 and R1 satisfy the following (Equation 1).

[0043] 0.9≦R1 / L1≦1.2 (Formula 1)

[0044] In other words, it is preferable, for example from the viewpoint of accurately controlling the light distribution by lens 210A, that the ratio of the distance R1 between the lens center 210Aa and the element center 21c to the length L1 of one side of the light-emitting element 21 is 0.9 or more and 1.2 or less. This also applies to lenses 210B and 210C. Note that the length L1 of one side of the light-emitting element 21 is the size of the outer shape (outermost part) of the light-emitting element 21 in a plan view. That is, if the light-emitting element 21 is an SMD type LED element comprising a square substrate (container or primary mounting substrate, etc.) in a plan view and an LED chip mounted on the substrate, L1 is the length of one side of the substrate in a plan view. If the outer shape of the substrate in a plan view is rectangular, L1 is the length of the longer side of the substrate.

[0045] In the lighting fixture 100 according to this embodiment, as described above, the number of lenses 210 provided by the optical member 200 is small compared to the number of light-emitting elements 21, thereby reducing the overlapping portion between adjacent lenses 210. Therefore, it is thought that reducing the size of the lenses 210 in a plan view would further reduce this overlapping portion. However, if the size of the lenses 210 is reduced, the area of ​​the light-emitting surface 211 will decrease accordingly, and as a result, some of the optical effects obtained by the lenses 210 will be lost. Specifically, there is a possibility that the light distribution control for two or more light-emitting elements 21 arranged opposite the lens 210 may not be properly performed. It is also conceivable that the area of ​​the light-emitting surface 211 can be increased by increasing the outer diameter of the lens 210, thereby improving the accuracy of light distribution control, but in this case, the problem of increased overlapping portion between adjacent lenses 210 arises. Therefore, the inventors of the present invention have diligently studied the outer diameter of the lens 210 and the position of the light-emitting elements 21, and have found conditions regarding the outer diameter of the lens 210, etc., that enable proper light distribution control. This will be explained in detail using lens 210A.

[0046] (3) In the lighting fixture 100 described in (2) above, as shown in Figure 9B, the lens 210A has a circular shape in plan view. When the radius of this lens 210A is R2, it is preferable that R1 and R2 (see Figures 9A and 9B) satisfy the following equation (Equation 2).

[0047] 8≦R2 / R1≦10 (Formula 2)

[0048] In other words, it is preferable that the ratio of the radius of lens 210A to the distance R1 between the lens center 210Aa and the element center 21c is 8 or more and 10 or less, from the viewpoint of improving the accuracy of light distribution control by lens 210A, for example. This also applies to lenses 210B and 210C. It is preferable that each of the multiple lenses 210A of the optical member 200 satisfies the above (Equation 2) for R1 and R2, from the viewpoint of improving the light extraction efficiency of the optical member 200 as a whole.

[0049] In this embodiment, in a lens 210 arranged facing two or more light-emitting elements 21 in the Z-axis direction, a recess 221 is arranged facing each of the two or more light-emitting elements 21. Preferably, the center of each of these recesses 221 is located on the optical axis of the light-emitting element 21. This will be specifically explained using lens 210A.

[0050] (4) In the lighting fixture 100 described in any one of (1) to (3) above, as shown in Figure 6, it is preferable that each of the two or more recesses 221 is located in the lens 210A at a position through which the optical axis 21a of one light-emitting element 21 facing the recess 221 passes.

[0051] In this embodiment, the center of the recess 221a is the point on the inner surface of the recess 221 that is furthest from the light-emitting element 21, that is, the point located furthest in the positive Z-axis direction. The center of the recess 221a can also be described as the deepest point in the recess 221. The optical axis 21a is a virtual line that passes through the element center 21c (see Figure 9A) and extends in the positive Z-axis direction.

[0052] Thus, by positioning the recess 221 such that its center 221a lies on the optical axis 21a of the light-emitting element 21, the light emitted from the light-emitting element 21 efficiently travels from the inner surface of the recess 221 into the lens 210A and is emitted to the outside from the light-emitting surface 211. In other words, the above configuration is advantageous from the viewpoint of improving the accuracy of light distribution control by the lens 210A. Lenses 210B and 210C also have this feature. For example, as shown in Figure 7, in lens 210C, the recess 221 is provided such that its center 221a is located at a position through which the optical axis 21a of one light-emitting element 21 facing the recess 221 passes. It is preferable from the viewpoint of improving the overall light extraction efficiency of the optical element 200 that each of the multiple lenses 210A of the optical element 200 satisfies the above positional relationship between the recess 221 and the optical axis 21a of the light-emitting element 21.

[0053] In this embodiment, the light-emitting surface 211 of lens 210 has a series of smooth curved shapes, except for the portion that overlaps with other lenses 210. It is preferable that this curved shape is rotationally symmetric. This will be specifically explained using lens 210A.

[0054] (5) In the lighting fixture 100 described in any one of (1) to (4) above, it is preferable that the light-emitting surface 211 of the lens 210A has a shape that is rotationally symmetric about a rotation axis 210Ab that passes through the center of the lens 210A (lens center 210Aa) in a plan view and extends in the front-to-back direction (Z-axis direction). In this embodiment, the shape of the light-emitting surface 211 is obtained by rotating the curved line representing the light-emitting surface 211, which is in the Y-axis positive direction more than the rotation axis 210Ab, by 360° about the rotation axis 210Ab, as shown in Figure 6. In other words, the shape of the light-emitting surface 211 coincides with any rotation angle about the rotation axis 210Ab, except for the overlapping portion with other lenses 210. The shape of the light-emitting surface 211 can also be described as having a shape that is rotationally symmetrical n times (where n is infinite) about the rotation axis 210Ab.

[0055] Thus, the single lens 210A that controls the light distribution from two or more light-emitting elements 21 has a series of smooth light-emitting surfaces 211 due to its rotational symmetry. This improves the uniformity of the light intensity (luminosity) emitted from the lens 210A in all directions when viewed from above. This contributes to suppressing light unevenness in the illumination light emitted by the lighting fixture 100.

[0056] The characteristics of the light-emitting surface 211 of lens 210A described above are also present in lenses 210B and 210C. For example, as shown in Figure 7, the light-emitting surface 211 of lens 210C has a rotationally symmetrical shape with respect to a rotation axis 210Cb that passes through the center of lens 210C (lens center 210Ca) in a plan view and extends in the front-to-back direction (Z-axis direction).

[0057] More specifically, it is preferable that the position of the rotation axis defining the rotational symmetry of the light-emitting surface 211 of the lens 210 coincides with the centers of two or more light-emitting elements 21 corresponding to the lens 210. This will be explained in detail using lens 210A.

[0058] (6) In the lighting fixture 100 described in any one of (1) to (5) above, it is preferable that the position of the rotation axis 210Ab (see Figure 6) in a plan view coincides with the center of the circle passing through the centers (element centers 21c) of each of the two or more light-emitting elements 21.

[0059] In this embodiment, as shown in Figure 9A, four light-emitting elements 21 are arranged in the lens 210A, and the center of the lens 210Aa coincides with the center of a circle with radius R1 that passes through the element centers 21c of the four light-emitting elements 21. Furthermore, the axis of rotation 210Ab that defines the rotational symmetry of the light-emitting surface 211 of the lens 210A passes through the lens center 210Aa and is parallel to the Z-axis, as shown in Figure 6. Therefore, the position of the axis of rotation 210Ab in a plan view coincides with the center of the circle that passes through the element centers 21c of each of the four light-emitting elements 21. In other words, the position of the center of two or more (four in Figures 6 and 9A) light-emitting elements 21 arranged on the XY plane, when viewed from the Z-axis direction, coincides with the geometric center position of the light-emitting surface 211. This further improves the uniformity of the light intensity (luminosity) emitted from the lens 210A in all directions in a plan view.

[0060] (Other embodiments) Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments.

[0061] In the above embodiment, the light-emitting module 10 is provided with 198 light-emitting elements 21, and these 198 elements 21 constitute 50 light-emitting element groups 20. However, the number of light-emitting elements 21 and light-emitting element groups 20 provided by the light-emitting module 10 is not limited to this. The light-emitting module 10 may be provided with multiple light-emitting element groups 20, and each of the multiple light-emitting element groups 20 may be composed of two or more light-emitting elements 21. The number of light-emitting elements 21 and light-emitting element groups 20 provided by the light-emitting module 10 may be appropriately determined according to the capacity required of the lighting fixture 100, or the environment in which the lighting fixture 100 is installed. The same applies to the size and shape of the substrate 11, optical member 200, and lighting cover 140, and are not limited to the sizes and shapes shown in Figures 1 to 4B.

[0062] The orientation of the multiple light-emitting elements 21 of the light-emitting element group 20 in a plan view is not limited to the orientation shown in Figure 9A, for example. For example, each of the four light-emitting elements 21 shown in Figure 9A may be rotated by a predetermined angle (e.g., 45°) around the element center 21c. The orientations of the multiple light-emitting elements 21 of the light-emitting element group 20 in a plan view do not need to be the same. In other words, the orientation of one or more of the multiple light-emitting elements 21 of the light-emitting element group 20 may differ from the orientation of the other light-emitting elements 21.

[0063] The optical component 200 may include multiple lenses 210 that are associated one-to-one with multiple light-emitting element groups 20, as well as one or more lenses that are associated one-to-one with one or more light-emitting elements 21. In other words, as long as the optical component 200 includes multiple lenses 210, each associated with two or more light-emitting elements 21, it may also include one or more additional lenses, and these one or more lenses may have any shape, size, and application.

[0064] The multiple light-emitting elements 21 provided in the light-emitting module 10 may include two or more types of light-emitting elements 21 with different emission colors (color temperatures). In this case, one group of light-emitting elements 20 (see Figure 3) includes two or more light-emitting elements 21 with the same emission color (color temperature). If the multiple groups of light-emitting elements 20 configured in this way are divided into, for example, a first group and a second group with different emission colors (color temperatures), one or more groups of light-emitting elements 20 in the first group and one or more groups of light-emitting elements 20 in the second group may be controlled independently of each other. This makes it possible to change both the brightness and color of the illumination light emitted from the lighting fixture 100.

[0065] Although the substrate 11 of the light-emitting module 10 is exemplified as a rectangular substrate 11 with the tips of its four corners cut off, the external shape of the substrate 11 of the light-emitting module 10 in plan view is not limited to this. For example, the external shape of the substrate 11 in plan view may be a polygon other than a rectangle, such as a triangular or pentagonal shape, or it may be a non-circular shape different from a polygon, such as an ellipse or oblong shape.

[0066] Furthermore, the substrate (module substrate) on which the multiple light-emitting elements 21 of the light-emitting module 10 are arranged does not have to be a single physical substrate, such as the substrate 11 shown in Figure 3. For example, a single module substrate may be formed by connecting multiple substrates, each having one or more light-emitting elements 21 arranged on it. For example, depending on the required size of the module substrate, it may be decided whether to realize the module substrate as a single substrate or as multiple substrates.

[0067] Furthermore, the substrate 11 of the light-emitting module 10 may be of a type other than the glass epoxy substrate and composite epoxy resin substrate (CEM-3) exemplified in the above embodiment. For example, a metal base substrate made of a metal material with a resin coating on its surface may be used. In this case, for example, the heat from the multiple light-emitting elements 21 and the multiple circuit components (not shown) arranged on the main surface 11a of the substrate 11 is efficiently conducted to the device body 110 via the substrate 11.

[0068] Although the light-emitting element 21 is described as an SMD type LED element, it is not limited to this. For example, the light-emitting module 10 may be a COB (Chip On Board) structure in which LED chips are directly mounted on the substrate 11. In this case, illumination light of a predetermined color temperature can be obtained by sealing multiple LED chips mounted on the substrate 11 together or individually with a sealing member containing a wavelength conversion material. When multiple LED chips mounted on the substrate 11 are individually sealed by a sealing member, one light-emitting element 21 comprises one LED chip and a sealing member that seals that one LED chip. In this case, the maximum width of the outer shape of the sealing member in a plan view (diameter in the case of a circle) may be treated as the length L1 of one side of the light-emitting element 21.

[0069] Furthermore, in the above embodiments and modifications, an LED element in which an LED chip is packaged was exemplified as the light-emitting element 21. However, other types of solid-state light-emitting elements such as semiconductor light-emitting elements like semiconductor lasers, or EL elements such as organic EL (Electro-Luminescence) or inorganic EL may be used as the light-emitting element 21.

[0070] Furthermore, the present invention also includes forms obtained by applying various modifications to the above embodiments and their variations that a person skilled in the art could conceive, as well as forms realized by arbitrarily combining the components and functions of each embodiment and its variations without departing from the spirit of the present invention. [Explanation of Symbols]

[0071] 10 Light-emitting modules 11 circuit boards 20, 20A, 20A1, 20A2, 20B light-emitting element group 21 Light-emitting element 21a Optical axis 21c element center 100 lighting fixtures 140 Lighting Cover 200 Optical Components 201 Main body 201a front 201b back side 210, 210A, 210B, 210C lenses 210Aa, 210Ca lens center 210Ab, 210Cb Rotation axis 211 Light exit surface 220 Incidence plane 221 Recess 221a Center of recess

Claims

1. A light-emitting module having multiple light-emitting elements that emit light forward, An optical member having multiple lenses and covering the multiple light-emitting elements, The optical member comprises a light-transmitting illumination cover positioned in front of the optical member, Each of the aforementioned lenses is It is arranged opposite to two or more of the plurality of light-emitting elements, Two or more recesses that form the inner surface into which light from the two or more light-emitting elements enters, and having two or more recesses that correspond one-to-one with the two or more light-emitting elements, Each of the two or more recesses is positioned opposite one of the two or more light-emitting elements. Each of the two or more light-emitting elements has a rectangular shape when viewed from the front. Let L1 be the length of one side in the aforementioned rectangle. When viewed from the front, if R1 is the distance between the center of the lens and the centers of each of the two or more light-emitting elements, The condition 0.9 ≤ R1 / L1 ≤ 1.2 is satisfied. The aforementioned lens has a circular shape when viewed from the front. If the radius of the aforementioned lens is R2, Satisfying 8 ≤ R² / R¹ ≤ 10, Lighting fixtures.

2. Each of the two or more recesses is provided in the lens such that the center of the recess is located at a position through which the optical axis of one of the light-emitting elements facing the recess passes. The lighting fixture according to claim 1.

3. A light-emitting module having a plurality of light-emitting elements that emit light forward, An optical member having multiple lenses and covering the multiple light-emitting elements, The optical member comprises a light-transmitting illumination cover positioned in front of the optical member, Each of the aforementioned lenses is It is arranged opposite to two or more of the plurality of light-emitting elements, Two or more recesses that form the inner surface into which light from the two or more light-emitting elements enters, and having two or more recesses that correspond one-to-one with the two or more light-emitting elements, Each of the two or more recesses is positioned opposite one of the two or more light-emitting elements. The light-emitting surface of the lens has a rotationally symmetrical shape with respect to an axis of rotation that passes through the center of the lens and extends in the front-to-back direction when viewed from the front. When viewed from the front, the position of the rotation axis coincides with the center of the circle passing through the center of each of the two or more light-emitting elements. Lighting fixtures.

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