Lighting device

Abstract

To provide a lighting device which can efficiently radiate light to an object.SOLUTION: A lighting device includes: a substrate; an LED light source which is disposed on a first direction side of the substrate so that light is radiated in the first direction; a reflection plate disposed at the first direction side of the substrate and having a reflection surface which reflects light from the LED light source; and a heat sink. A surface of the reflection plate which is opposite to the reflection surface is in contact with the heat sink.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The following disclosure relates to lighting devices. [Background technology]

[0002] For example, Patent Document 1 discloses a straight tube type LED lighting tube that is provided with a reflector in its internal space for reflecting light emitted from an LED. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-99674 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide an illumination device that can efficiently irradiate an object with light. [Means for solving the problem]

[0005] The lighting device of the present disclosure includes a substrate, an LED light source arranged on the first direction side of the substrate so that light is irradiated in the first direction, a reflector arranged on the first direction side of the substrate and having a reflective surface that reflects light from the LED light source, and a heat sink, and it is preferable that the surface of the reflector opposite to the reflective surface be in contact with the heat sink. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide an illumination device that can efficiently irradiate an object with light. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view of a lighting device 10 according to a first embodiment. [Figure 2] 1 is a perspective view showing the internal structure of an illumination device 10 according to a first embodiment. [Figure 3] FIG. 2 is an enlarged perspective view showing the internal structure of the lighting device 10 of the first embodiment. [Figure 4] 2 is a cross-sectional view of the lighting device 10 of the first embodiment taken along the line A1-A2 in FIG. [Figure 5] 1 is a perspective view showing the internal structure of an end portion of the lighting device 10 of the first embodiment. [Figure 6] 2 is a perspective view showing the internal structure of a joint portion included in the lighting device 10 of the first embodiment. FIG. [Figure 7] 1 is a longitudinal cross-sectional view showing the internal structure of an end portion of the lighting device 10 of the first embodiment. [Figure 8] 10 is an enlarged cross-sectional view of the lighting device 10 of the second embodiment when the heat sink is provided with a second extension portion. FIG. [Figure 9] 10 is an enlarged cross-sectional view of the lighting device 10 of the second embodiment when the heat sink does not include a second extension portion. FIG. [Figure 10] FIG. 10 is a cross-sectional view of the lighting device 10 of the third embodiment. [Figure 11] FIG. 10 is a perspective view illustrating a mode in which a cable is connected to the lighting device 10 of the modified example. [Figure 12] FIG. 10 is a perspective view showing a state in which a plurality of lighting devices 10 according to a modified example are connected together. [Figure 13] FIG. 10 is a longitudinal cross-sectional view showing a state in which a plurality of lighting devices 10 according to a modified example are connected together. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of a lighting device according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the contents described in the following embodiments, and appropriate design changes can be made within the scope of the configuration of the present disclosure. In the drawings, identical or equivalent elements are given the same reference numerals, and redundant explanations will be omitted. The following description will focus on the main parts and parts related to the present disclosure.

[0009] In this specification, when two lines or planes are "parallel," it means that the angle (absolute value) they form is within the range of 0°±3°. When two lines or planes are "orthogonal" (and "perpendicular"), it means that the angle (absolute value) they form is within the range of 90°±3°.

[0010] (Embodiment 1) Fig. 1 is a perspective view of the lighting device 10 of the first embodiment. Fig. 2 is a perspective view showing the internal structure of the lighting device 10 of the first embodiment. Fig. 3 is an enlarged perspective view showing the internal structure of the lighting device 10 of the first embodiment. Fig. 4 is a cross-sectional view of the lighting device 10 of the first embodiment taken along the line A1-A2 in Fig. 1.

[0011] An illumination device 10 of this embodiment will be described with reference to Figures 1 to 4. As shown in Figures 1 to 4, the illumination device 10 of this embodiment includes a substrate 11, an LED light source 12 arranged on the first direction D1 side of the substrate 11 so as to irradiate light in the first direction D1, and a reflector 14X arranged on the first direction D1 side of the substrate 11 and reflecting the light from the LED light source 12. In this aspect, the illumination device 10 is able to reflect the light emitted from the LED light source 12 in the first direction D1 by the reflector 14X, and can efficiently irradiate light onto an object located on the first direction D1 side of the illumination device 10.

[0012] Here, LED light sources have a wide illumination angle, and when they emit light, they radiate the surrounding area radially. Therefore, instead of concentrating all of the light in a specific direction, such as directly below the light source (i.e., directly in front of the LED light source) or in the surrounding space, the light is dispersed in unnecessary directions, such as horizontally. Therefore, even if the LED light source itself has high luminance, it can be difficult to achieve sufficient illuminance. In particular, lighting devices for plant growth are required to efficiently irradiate only the plants with the amount of light necessary for plant growth. However, conventional lighting devices for plant growth simply irradiate light from the LED light source outward, irradiating light on areas other than the plants, which is inefficient. For example, the lighting tube described in Patent Document 1 also disperses light when a desired illuminance (brightness) is required in a specific area, resulting in insufficient illuminance.

[0013] On the other hand, the lighting device 10 of this embodiment is arranged on the first direction D1 side of the substrate 11 and includes a reflecting portion 14X that reflects light from the LED light source 12. Therefore, the reflecting portion 14X changes the angle of light emitted from the LED light source 12, and the light that would conventionally be emitted in a horizontal direction, etc., can be distributed directly below the LED light source 12 (the first direction D1 side of the LED light source 12) and the surrounding space, thereby concentrating the amount of light.

[0014] In this way, the lighting device 10 of this embodiment can distribute the entire amount of light radially irradiated from the LED light source 12 in a specific direction directly below the LED light source 12 and in the surrounding space without waste, thereby eliminating light loss and improving the illuminance and photosynthetic photon flux density (PPFD) in the illuminated surface directly below the LED light source 12 and in the surrounding space, etc. Therefore, the lighting device 10 of this embodiment can be suitably used as a lighting device for growing plants.

[0015] Furthermore, in the lighting device 10 of this embodiment, by concentrating the light from the LED light source 12 directly below the LED light source 12 (in front of the LED light source 12), it is possible to prevent the light from hitting the side surfaces of the lighting device 10, and therefore it is possible to prevent the lighting device 10 itself from becoming hot, and it also has an excellent heat dissipation effect. The lighting device 10 of this embodiment will be described in detail below.

[0016] As shown in Fig. 3, the substrate 11 is preferably an elongated member, for example, an electronic circuit board having a main surface that is an elongated flat plate.

[0017] The LED light source 12 is disposed on the first direction D1 side of the substrate 11 so as to irradiate light in the first direction D1. Specifically, the LED light source 12 is attached to a surface 11A on the first direction D1 side of the substrate 11. The LED light source 12 is, for example, a white LED that emits white light when a voltage equal to or greater than a predetermined value is applied thereto, but is not limited to a white LED.

[0018] The first direction D1 is, for example, a direction perpendicular to the main surface (also referred to as the substrate 11 surface) of the substrate 11. If the surface of the substrate 11 is not flat but has recesses, protrusions, or the like, the direction perpendicular to the surface of the substrate 11 can be determined by assuming that the surface of the substrate 11 is flat and has no recesses, protrusions, or the like.

[0019] The lighting device 10 preferably includes a plurality of LED light sources 12. The plurality of LED light sources 12 are arranged at regular intervals along the longitudinal direction of the substrate 11, for example, on a surface 11A on the first direction D1 side of the substrate 11, at a central position in the width direction, as shown in FIG.

[0020] 3, the LED light sources 12 are arranged in a row, but the arrangement of the LED light sources 12 is not limited to the above configuration and may be arranged in multiple rows, such as two rows. Furthermore, instead of being arranged in an orderly manner at regular intervals, the LED light sources 12 may be arranged in a wave or zigzag pattern along the longitudinal direction of the substrate 11.

[0021] The substrate 11 may have a flat surface, or may have a recess or protrusion formed at the location where the LED light source 12 is attached.

[0022] The lighting device 10 preferably includes a heat sink 13. The lighting device 10 of this aspect can dissipate heat generated from the substrate 11, the LED light source 12, etc. by the heat sink 13. The heat sink 13 includes, for example, a metal material with heat dissipation properties, such as aluminum. As shown in FIG. 3 , the heat sink 13 is preferably disposed so as to extend in the longitudinal direction of the substrate 11 (i.e., disposed along the longitudinal direction of the substrate 11). The total length of the heat sink 13 in the longitudinal direction is preferably, for example, the same as or longer than the total length of the substrate 11 in the longitudinal direction.

[0023] 4, the heat sink 13 preferably includes a support portion 13A that contacts the surface 11B of the substrate 11 opposite to the first direction D1. In the lighting device 10 of this embodiment, the heat sink 13 can be stably fixed, and the effect of the heat sink 13 is more effectively exhibited. The support portion 13A preferably extends, for example, in the longitudinal direction of the substrate 11, i.e., is disposed along the longitudinal direction of the substrate 11. Furthermore, from the viewpoint of more stably supporting the heat sink 13, it is more preferable that the support portion 13A contacts the surface 11B of the substrate 11 opposite to the first direction D1 and covers the entire surface 11B of the substrate 11 opposite to the first direction D1.

[0024] The heat sink 13 preferably includes a plurality of heat dissipation fins 13B extending from the support portion 13A in the direction opposite to the first direction D1. With this configuration, heat generated from the substrate 11, the LED light source 12, etc. is transferred to the support portion 13A, and the heat transferred to the support portion 13A can be dissipated to the outside of the lighting device 10 by the plurality of heat dissipation fins 13B.

[0025] Specifically, the heat dissipation fins 13B are plate-like members extending from the support portion 13A to the side opposite to the first direction D1 along the longitudinal direction of the substrate 11, and a plurality of the heat dissipation fins 13B are provided in the shape of strips on the support portion 13A. The upper end portion of the heat dissipation fins 13B (i.e., the end portion opposite to the first direction D1) serves as a power supply mounting surface on which the power supply 15 described below is mounted.

[0026] The heat sink 13 is preferably positioned at an end of the substrate 11 and has a protrusion 13C that protrudes from the support 13A toward the first direction D1. In the lighting device 10 of this aspect, the substrate 11 can be held by the support 13A and the protrusion 13C. As a result, the substrate 11 and the heat sink 13 can be stably held (for example, the substrate 11 and the heat sink 13 can be integrated) without using adhesive, making it easy to assemble the lighting device 10. It is more preferable that the heat sink 13 has a pair of protrusions 13C at both ends of the substrate 11, as will be described later.

[0027] The protruding portion 13C has a generally T-shaped cross section and protrudes from the supporting portion 13A into the internal space 16 of the lighting device 10. The protruding portion 13C includes, for example, a first extending portion 13C1 extending from the supporting portion 13A toward the first direction D1, and a second extending portion 13C2 connected to an end portion 13C1T of the first extending portion 13C1 on the first direction D1 side and extending in a direction intersecting the extension direction of the first extending portion 13C1. In other words, the protrusion 13C has a first extension portion 13C1 that is continuous with the support portion 13A and is provided on the first direction D1 side of the support portion 13A, and a second extension portion 13C2 that is connected to the end portion 13C1T on the first direction D1 side of the first extension portion 13C1, and it is preferable that in a cross-sectional view (cross-section viewed from the third direction D3), the direction in which the central axis of the first extension portion 13C1 extends intersects with the direction in which the central axis of the second extension portion 13C2 extends (see Figure 4).

[0028] The reflecting portion 14X is disposed on the first direction D1 side of the substrate 11 and reflects light from the LED light source 12. In the lighting device 10 configured as described above, the reflecting portion 14X can reflect the light emitted from the LED light source 12 toward the first direction D1 side, and the lighting device 10 can efficiently irradiate the light onto an object located on the first direction D1 side.

[0029] 3, the reflecting portion 14X extends, for example, in the longitudinal direction of the substrate 11. The total length of the reflecting portion 14X in the longitudinal direction corresponds to the range in which the LED light source 12 is arranged.

[0030] When the distance between the lighting device 10 and the target plant (the root portion, i.e., the surface on which the plant is planted) is 20 cm or more and 40 cm or less, in a cross-sectional view (a cross-section viewed from the third direction D3), the angle α between the reflecting portion 14X and the first direction D1 is preferably 30° or more and 60° or less, more preferably 35° or more and 55° or less, and even more preferably 40° or more and 50° or less. The distance between the lighting device 10 and the plant (the root portion, i.e., the surface on which the plant is planted) is more preferably 25 cm or more and 35 cm or less, and even more preferably 30 cm.

[0031] 4, the lighting device 10 preferably includes a power supply 15 that supplies a predetermined current to the LED light source 12. The power supply 15 is preferably disposed on the side opposite the first direction D1 of the substrate 11. By adopting such an embodiment, the power supply 15 is disposed in a position that does not interfere with the LED light source 12, and therefore the lighting device 10 can more efficiently irradiate light onto an object located on the first direction D1 side.

[0032] The power supply 15 is disposed, for example, on one end side in the longitudinal direction of the substrate 11. The power supply 15 is fixed, for example, between the heat dissipation fins 13B of the heat sink 13 with screws.

[0033] 4, the lighting device 10 preferably includes a tube 17 that houses the substrate 11, the LED light source 12, and the reflector 14X. The tube 17 has an internal space 16 that can house the substrate 11, the LED light source 12, and the reflector 14X. As shown in FIG. 1, the tube 17 is, for example, a cylindrical member that extends along the longitudinal direction of the substrate 11.

[0034] The tube 17 can be made of a material such as glass or synthetic resin. For example, the tube 17 may be a long, cylindrical member integrally formed from a material having a predetermined elasticity, such as polycarbonate resin. The tube 17 is entirely or partially translucent, and is made of a transparent, semi-transparent, or colored transparent material as long as it is translucent.

[0035] The total length of the tube 17 in the longitudinal direction is set to, for example, approximately the same as the total length of the support part 13A of the heat sink 13 excluding the joint parts 18 attached to both longitudinal ends of the support part 13A. Both longitudinal end edges of the tube 17 are in close contact with the inner end edges of the joint parts 18 without any gaps.

[0036] Fig. 5 is a perspective view showing the internal structure of an end portion of the lighting device 10 of Embodiment 1. Fig. 6 is a perspective view showing the internal structure of a joint portion included in the lighting device 10 of Embodiment 1. Fig. 7 is a longitudinal cross-sectional view showing the internal structure of the end portion of the lighting device 10 of Embodiment 1.

[0037] 5 to 7, the lighting device 10 preferably includes a joint portion 18 that closes the ends (preferably both ends) of the tubular body 17. The joint portion 18 has, for example, a cylindrical structure with an internal space 18X. The joint portion 18 has a structure in which the end on the tubular body 17 side is open and the end opposite the tubular body 17 is closed.

[0038] The joint part 18 preferably has a cover part 18A formed in a substantially circular disk shape with approximately the same diameter as the end face of the tube 17, and a fitting part 18B that fits into the opening in the end face of the tube 17. By adopting such an embodiment, the joint part 18 can be attached by fitting over the end parts of the tube 17 and the heat sink 13 at both ends of the tube 17 in the longitudinal direction.

[0039] The lid portion 18A has a protrusion 18A1 on the inside thereof that fits onto the heat dissipation fin 13B. The joint portion 18 having such a configuration can stably fix the heat sink 13 inside the tubular body 17.

[0040] The lighting device 10 preferably includes a connector 19 to which an electrical cable can be connected.

[0041] (Embodiment 2) 4, the lighting device 10 of this embodiment includes a reflector 14 having a reflective surface 14A as the reflector 14X in the first embodiment. Specifically, the lighting device 10 of this embodiment includes a substrate 11, an LED light source 12 arranged on the first direction D1 side of the substrate 11 so as to irradiate light in the first direction D1, a reflector 14 arranged on the first direction D1 side of the substrate 11 and having a reflective surface 14A that reflects light from the LED light source 12, and a heat sink 13, where a surface 14B of the reflector 14 opposite to the reflective surface 14A is in contact with the heat sink 13. The lighting device 10 of this embodiment can reflect light that has passed through the reflector 14 without being reflected by the reflective surface 14A, using the heat sink 13, thereby improving light utilization efficiency and enabling light to be more efficiently irradiated onto an object.

[0042] The reflective surface 14A is disposed on the first direction D1 side of the substrate 11 and reflects light from the LED light source 12. With this configuration, the light emitted from the LED light source 12 can be reflected by the reflective surface 14A in the first direction D1 side, and the lighting device 10 can efficiently irradiate light onto an object located on the first direction D1 side.

[0043] The reflector 14 and the reflecting surface 14A extend, for example, in the longitudinal direction of the substrate 11. The total length of the reflector 14 and the reflecting surface 14A in the longitudinal direction corresponds to the range in which the LED light source 12 is arranged.

[0044] The preferred range of the angle formed between the reflecting surface 14A and the first direction D1 is the same as the angle α formed between the reflecting portion 14X and the first direction D1 described above, and therefore, description thereof will be omitted.

[0045] 8 is an enlarged cross-sectional view of the lighting device 10 of the second embodiment, in which the heat sink includes a second extension portion. As shown in FIG. 8, the heat sink 13 of the second embodiment includes a support portion 13A that contacts the surface 11B of the substrate 11 opposite the first direction D1, and a protrusion 13C that is located at the end of the substrate 11 and protrudes from the support portion 13A in the first direction D1. The protrusion 13C includes a first extension portion 13C1 that extends from the support portion 13A in the first direction D1, and a second extension portion 13C2 that extends along the reflecting surface 14A. The surface 14B of the reflecting plate 14 opposite the reflecting surface 14A is preferably in contact with the second extension portion 13C2. The lighting device 10 of this embodiment allows the second extension portion 13C2 of the heat sink 13 to effectively reflect light that passes through the reflecting plate 14 without being reflected by the reflecting surface 14A. As a result, the lighting device 10 can effectively improve the light utilization efficiency, and can more efficiently irradiate the object with light.

[0046] Fig. 9 is an enlarged cross-sectional view of the lighting device 10 of Embodiment 2 when the heat sink does not include a second extension portion. The protrusion 13C included in the lighting device 10 shown in Fig. 9 includes a first extension portion 13C1 extending from the support portion 13A toward the first direction D1, and a convex portion 13C3 that does not extend in the direction along the reflective surface 14A.

[0047] In the lighting device 10 shown in Fig. 9 that does not include a second extension portion, even if the reflective surface 14A and the reflector 14 are made of a highly reflective material, if the reflector 14 does not have a sufficient thickness, light from the LED light source 12 may be transmitted to the side opposite the reflective surface 14A of the reflector 14, resulting in light loss and insufficient reflection. In particular, when the reflective surface 14A and the reflector 14 are made of resin, light loss becomes significant. Furthermore, since the highly reflective materials used for the reflector 14 and the reflective surface 14A are generally expensive, producing a reflector of sufficient thickness using such materials leads to increased costs.

[0048] On the other hand, in the lighting device 10 having the second extension portion 13C2 shown in Figure 8, the surface 14B opposite to the reflective surface 14A of the reflector 14 is in contact with the second extension portion 13C2 of the protrusion 13C, thereby preventing light leakage and enabling efficient reflection of light.

[0049] It is preferable that reflector 14 continuously covers the entire surface of second extension portion 13C2 from surface 13C2A on the first direction D1 side to surface 13C2B on the opposite side from first direction D1. In lighting device 10 of this aspect, light that passes through reflector 14 without being reflected by reflective surface 14A can be more effectively reflected toward first direction D1 by heat sink 13, thereby more effectively improving light utilization efficiency and enabling light to be irradiated onto an object more efficiently.

[0050] (Embodiment 3) Fig. 10 is a cross-sectional view of the lighting device 10 of embodiment 3. Like Fig. 4, Fig. 10 is a cross-sectional view of the lighting device 10 of embodiment 3 taken along line A1-A2 in Fig. 1. As shown in Fig. 10, the lighting device 10 of this embodiment is substantially the same as the lighting device of embodiment 1 or 2, except that the shape of the heat sink 13 is different.

[0051] The heat sink 13 of this embodiment further includes a reflector cover 13D, which is disposed on the side of the reflector 14 opposite the reflection direction of light reflected by the reflector 14. In the lighting device 10 of this embodiment, the reflector cover 13D can sufficiently reduce or fill the gap between the reflector 14 and the inner surface of the tube 17, thereby sufficiently preventing light from leaking through the gap without being reflected by the reflective surface 14A. Furthermore, although light that has passed through the reflector 14 may leak between the end 13C21 of the second extension portion 13C2 facing outward from the tube 17 and the inner surface of the tube 17, the reflector cover 13D can reflect the light that has passed through the reflector 14. As a result, the lighting device 10 can effectively improve light utilization efficiency and more efficiently irradiate light onto an object.

[0052] The reflector cover portion 13D is arranged, for example, from the support portion 13A or the protruding portion 13C toward the inner surface (also referred to as the inner surface) of the tubular body 17. The reflector cover portion 13D is preferably arranged from the protruding portion 13C toward the inner surface of the tubular body 17. The lighting device 10 of this aspect can irradiate the object with light more efficiently. For example, the reflector cover portion 13D is preferably arranged from the first extension portion 13C1 of the protruding portion 13C toward the inner surface of the tubular body 17.

[0053] It is preferable that the reflector cover portion 13D is disposed at least up to the vicinity of the inner surface of the tubular body 17. The lighting device 10 of this embodiment can irradiate the object with light more efficiently. The tip of the reflector cover portion 13D may or may not be in contact with the inner surface of the tubular body 17, but it is more preferable that it be in contact.

[0054] Preferably, the reflector 14 has a bent portion that continuously covers the surface of the second extension portion 13C2 facing the first direction D1, through the end 13C21 of the second extension portion 13C2 facing outward from the tube 17, to the surface opposite the first direction D1, and the reflector cover portion 13D is disposed on the opposite side of the bent portion in the first direction D1. The lighting device 10 of this aspect can effectively reflect light that passes through the space between the end 13C21 of the second extension portion 13C2 facing outward from the tube 17 and the inner surface of the tube 17 (i.e., the bent portion of the reflector 14). As a result, the lighting device 10 can effectively improve light utilization efficiency and more efficiently irradiate light onto an object.

[0055] (Variation) As shown in FIG. 4 , the lighting device 10 of this modification is a lighting device 10 (specifically, a lighting tube 100) having a tube body 17, and includes a pair of reflectors 14X according to the first or second embodiment. Specifically, the lighting device 10 of this modification includes a substrate 11, an LED light source 12 disposed on the first direction D1 side of the substrate 11 so as to irradiate light in the first direction D1, a pair of reflectors 14X disposed on the first direction D1 side of the substrate 11 and reflecting light from the LED light source 12, and a tube body 17 accommodating the substrate 11, the LED light source 12, and the pair of reflectors 14X. This configuration changes the angle of light emitted from the LED light source 12, and the lighting device 10 can distribute light that would conventionally be emitted laterally, within an area sandwiched between the pair of reflectors 14X, i.e., directly below the LED light source 12 (the first direction D1 side of the LED light source 12) and the surrounding space, thereby concentrating the amount of light.

[0056] The pair of reflecting portions 14X are disposed at both ends in the second direction D2 of the substrate 11. The second direction D2 is, for example, perpendicular to the first direction D1.

[0057] Furthermore, in the lighting device 10 of this modification, the LED light source 12 (specifically, the entire LED light source 12) is disposed on the first direction D1 side of the centroid 17X of the tube 17 in a cross-sectional view of the tube 17. By adopting this configuration, the distance between the LED light source 12 and an object located on the first direction D1 side of the lighting device 10 can be shortened compared to when the LED light source 12 (specifically, the entire LED light source 12) is disposed on the opposite side of the centroid 17X of the tube 17 in the first direction D1 in a cross-sectional view of the tube 17. As a result, the lighting device 10 can more efficiently irradiate light onto the object. Note that the cross-sectional view of the tube 17 specifically refers to a cross-sectional view taken along a plane including the first direction D1 and the second direction D2.

[0058] When the tube 17 has a longitudinal shape, for example, the first direction D1 and the second direction D2 are parallel to the short-side direction of the tube 17. Furthermore, a third direction D3 that is perpendicular to the first direction D1 and the second direction D2 is parallel to the long-side direction of the tube 17. When the tube 17 has a longitudinal shape, the substrate 11 and the support portion 13A of the heat sink 13 also have a longitudinal shape, the second direction D2 is parallel to the short-side direction of the substrate 11 and the support portion 13A, and the third direction D3 is parallel to the long-side direction of the substrate 11 and the support portion 13A.

[0059] The lighting device 10 of this embodiment is, for example, a straight-tube LED lighting tube. The overall length of the lighting tube 100 is the same as that of a conventional straight-tube fluorescent lamp, and can be set appropriately to, for example, 600 mm, 900 mm, 1200 mm, 1800 mm, 2400 mm, etc. depending on the application. The diameter of the lighting tube 100 is also approximately the same as that of a conventional straight-tube fluorescent lamp, and the lighting tube 100 has an overall shape and appearance that are approximately the same as that of a straight-tube fluorescent lamp.

[0060] In a cross-sectional view of the tube 17, the substrate 11 (specifically, the entire substrate 11) is preferably disposed closer to the first direction D1 than the centroid 17X of the tube 17. By adopting such an embodiment, the space on the opposite side of the substrate 11 from the first direction D1 can be expanded compared to when the substrate 11 (specifically, the entire substrate 11) is disposed on the opposite side of the centroid 17X of the tube 17 from the first direction D1. As a result, components included in the lighting device 10 (for example, the heat dissipation fins 13B of the heat sink 13 and the power supply 15) can be stored in a space on the opposite side of the substrate 11 from the first direction D1 where they do not interfere with the light of the LED light source 12, thereby improving the light utilization efficiency of the lighting device 10.

[0061] In a cross-sectional view of the tubular body 17, the support portion 13A (specifically, the entire support portion 13A) is preferably disposed closer to the first direction D1 than the centroid 17X of the tubular body 17. In the lighting device 10 of this aspect, it is possible to increase the space on the side opposite the first direction D1 of the support portion 13A compared to a case in which the support portion 13A (specifically, the entire support portion 13A) is disposed on the side opposite the first direction D1 than the centroid 17X of the tubular body 17. As a result, components included in the lighting device 10 (for example, the heat dissipation fins 13B of the heat sink 13 and the power supply 15) can be stored in the space on the side opposite the first direction D1 of the support portion 13A where they do not interfere with the light of the LED light source 12, thereby improving the light utilization efficiency of the lighting device 10.

[0062] The lighting device 10 further includes a heat sink 13. The heat sink 13 preferably includes a support portion 13A that contacts a surface 11B of the substrate 11 opposite the first direction D1, and a pair of protrusions 13C that are located at both ends of the substrate 11 and protrude from the support portion 13A toward the first direction D1, and the pair of protrusions 13C hold the pair of reflecting portions 14X. The lighting device 10 of this aspect can stably hold the heat sink 13 and the pair of reflecting portions 14X (for example, integrate the pair of reflecting portions 14X and the heat sink 13) without using adhesive, making it easy to assemble the lighting device 10. The pair of protrusions 13C are located at both ends of the substrate 11 in the second direction D2.

[0063] Preferably, each of the pair of reflecting portions 14X is located between the corresponding one of the pair of protruding portions 13C and the tube 17 (sandwiched between the protruding portion 13C and the tube 17). By adopting such an embodiment, the pair of protruding portions 13C can hold the pair of reflecting portions 14X. As a result, the lighting device 10 can stably hold the heat sink 13 and the pair of reflecting portions 14X without using adhesive. More preferably, each of the pair of reflecting portions 14X is located between the corresponding one of the pair of second extending portions 13C2 and the tube 17 (sandwiched between the second extending portion 13C2 and the tube 17).

[0064] The pair of protrusions 13C constitute a pair of locking means at both ends of the substrate 11. Preferably, each of the pair of protrusions 13C includes a first extension portion 13C1 extending from the support portion 13A toward the first direction D1, and a second extension portion 13C2 connected to an end portion 13C1T of the first extension portion 13C1 on the first direction D1 side and extending toward the inside and outside of the tube 17. This configuration allows the pair of protrusions 13C to more stably hold the pair of reflecting portions 14X. Furthermore, since the pair of protrusions 13C include the first extension portion 13C1 and the second extension portion 13C2, respectively, the substrate 11 can be slidably inserted between the support portion 13A of the heat sink 13 and the pair of second extension portions 13C2 (specifically, portions of the second extension portion 13C2 located toward the inside of the tube 17 from the end portion 13C1T), and the pair of second extension portions 13C2 can hold the substrate 11. As a result, the substrate 11 and the heat sink 13 are more stably held without using adhesive, making it easier to assemble the lighting device 10.

[0065] Preferably, each of the pair of reflecting portions 14X continuously covers from a surface 13C2A on the first direction D1 side to a surface 13C2B on the opposite side to the first direction D1 side of the second extending portion 13C2 of the corresponding one of the pair of protruding portions 13C. By adopting such an embodiment, the pair of protruding portions 13C (specifically, the second extending portion 13C2) can more stably hold the pair of reflecting portions 14X.

[0066] In a cross-sectional view of the tubular body 17, it is preferable that an end 13C21 of the second extension portion 13C2 facing outward from the tubular body 17 is located closer to the first direction D1 than an end 13C22 of the second extension portion 13C2 facing inward from the tubular body 17. With this configuration, when the reflecting portions 14X are arranged to cover the second extension portion 13C2, the reflecting portions 14X are arranged to face each other across the LED light source 12, and therefore the lighting device 10 can more effectively irradiate light onto an object (specifically, a plant) located on the first direction D1 side.

[0067] The pair of reflecting portions 14X are preferably arranged so as to face the LED light source 12 side along the third direction D3 (the longitudinal direction of the tube body 17). That is, the pair of reflecting portions 14X are preferably arranged parallel to each other so as to face each other across the row of LED light sources 12 arranged on the first direction D1 side of the substrate 11. By adopting such an embodiment, the lighting device 10 can more efficiently irradiate light onto an object located on the first direction D1 side.

[0068] In a cross-sectional view of the tubular body 17, each reflective portion 14X (specifically, the entire reflective portion 14X) is preferably disposed on the first direction D1 side of the centroid 17X of the tubular body 17. By adopting such an embodiment, the length of each reflective portion 14X can be shorter than when each reflective portion is disposed on the opposite side of the first direction, and therefore the internal structure of the lighting device 10 can be further simplified. As a result, the manufacturing cost of the lighting device 10 can be reduced.

[0069] The pair of reflecting portions 14X can be formed, for example, by applying white paint to the surfaces 13C2A of the second extending portions 13C2 of the corresponding one of the pair of protruding portions 13C on the first direction D1 side. In this case, the heat sink 13 can function as the reflecting portions 14X.

[0070] Each reflecting portion 14X may be a reflecting plate 14 having a reflecting surface 14A. The reflecting plate 14 preferably contains a highly reflective material (e.g., a resin such as polycarbonate). Using a highly reflective material makes it easy to process each reflecting portion 14X (reflecting plate 14) into a complex shape. Therefore, for example, it is easy to form a reflecting portion 14X having a shape that continuously covers the second extension portion 13C2 of the heat sink 13 from the surface 13C2A on the first direction D1 side to the surface 13C2B on the opposite side from the first direction D1 side, thereby making it possible to irradiate light onto an object more efficiently while reducing costs. The reflecting plate 14 may also contain a predetermined metal material such as aluminum.

[0071] The tube 17 accommodates the substrate 11, the LED light source 12, the heat sink 13, the pair of reflectors 14X, and the power supply 15 inside.

[0072] The lighting device 10 includes a joint portion 18 that closes the end of the tube 17. In a cross-sectional view of the tube 17, the joint portion 18 is preferably located on the opposite side of the first direction D1 from the end of the reflecting portion 14X on the first direction D1 side. To prevent light emitted from the LED light source from being shaded by the joint portion, the joint portion needs to be located on the opposite side of the first direction D1 from the LED light source. However, since the lighting device 10 of this modification includes the reflecting portion 14X, if the joint portion 18 is located on the opposite side of the first direction D1 from the end of the reflecting portion 14X on the first direction D1 side, the light emitted from the LED light source 12 can be prevented from being blocked by the joint portion 18. This allows the lighting device 10 to improve light utilization efficiency and more efficiently irradiate light onto an object.

[0073] The lighting device 10 preferably includes a connector 19 to which an electric cable can be connected, the pair of reflecting portions 14X being disposed at both ends of the substrate 11 in the second direction D2, and the connector 19 being disposed so as to protrude into a plane including the first direction D1 and the second direction D2. By adopting such an embodiment, the end face in the third direction D3 orthogonal to the first direction D1 and the second direction D2 can be made flat, thereby realizing seamless connection when multiple lighting devices 10 are connected in the third direction D3. The connector 19 is disposed, for example, in the joint portion 18 (specifically, the lid portion 18A).

[0074] The lighting device 10 also includes a connector 19 to which an electric cable can be connected. The connector 19 is preferably located on the opposite side of the first direction D1 from the end of the reflector 14X on the first direction D1 side in a cross-sectional view of the tube body 17. To prevent light emitted from the LED light source from hitting the connector and casting a shadow on it, the connector needs to be located on the opposite side of the first direction D1 from the LED light source. However, since the lighting device 10 of this modification includes the reflector 14X, if the connector 19 is located on the opposite side of the first direction D1 from the end of the reflector 14X on the first direction D1 side, the lighting device 10 can prevent light emitted from the LED light source 12 from being blocked by the connector 19, thereby improving light utilization efficiency and enabling light to be more efficiently irradiated onto an object.

[0075] The lighting device 10 also includes a connector 19 to which an electric cable can be connected, and it is more preferable that the connector 19 is disposed on the opposite side of the first direction D1 from the LED light source 12 in a cross-sectional view of the tube body 17. The lighting device 10 of this aspect can effectively prevent the light emitted from the LED light source 12 in the first direction D1 from being blocked by the connector 19, thereby effectively increasing the light utilization efficiency and enabling light to be irradiated onto an object more efficiently.

[0076] Fig. 11 is a perspective view illustrating a state in which a cable is connected to the lighting device 10 of the modified example. Fig. 12 is a perspective view showing a state in which a plurality of lighting devices 10 of the modified example are connected. Fig. 13 is a longitudinal cross-sectional view showing a state in which a plurality of lighting devices 10 of the modified example are connected.

[0077] As shown in FIGS. 11 to 13 , one of the connectors 19 arranged at both ends of the lighting device 10 may be an input connector 19A into which current is input from outside the lighting device 10. For example, an AC 100V input cable 21 is connected to the input connector 19A. The other of the connectors 19 at both ends may be a transition connector 19B for electrically connecting two adjacent lighting devices 10. For example, an AC 100V transition cable 22 is connected to the transition connector 19B. By connecting the transition connector 19B of one of the two adjacent lighting devices 10 to the transition connector 19B of the other lighting device 10 via the transition cable 22, multiple lighting devices 10 can be connected in the third direction D3 (longitudinal direction).

[0078] 11 to 13, the lighting device 10 includes a joint portion 18 that closes the end of the tube body 17, and the joint portion 18 preferably has a light-transmitting portion 18Y at least on the first direction D1 side and includes an LED light source 18Z for the joint portion inside. By adopting this configuration, when a plurality of lighting devices 10 are connected in the third direction D3 (longitudinal direction), a light source that irradiates light in the first direction D1 side is also disposed near the connection portion, thereby achieving seamless light emission in which the boundary between two adjacent lighting devices 10 is not noticeable.

[0079] The light-transmitting portion 18Y is entirely or partially light-transmitting, and is formed of a transparent, semi-transparent, or colored transparent material as long as it can transmit light.

[0080] The lighting device 10 preferably includes a plurality of LED light sources 12, a pair of reflectors 14X are disposed at both ends of the substrate 11 in the second direction D2, and the plurality of LED light sources 12 and the joint LED light source 18Z are disposed at equal intervals along a third direction D3 that is perpendicular to the first direction D1 and the second direction D2. By adopting such an embodiment, when a plurality of lighting devices 10 are connected in the third direction D3 (longitudinal direction), seamless light emission is achieved in which the boundary between two adjacent lighting devices 10 is less noticeable.

[0081] 13, when a plurality of lighting devices 10 are connected in the third direction D3 (longitudinal direction), it is preferable that the joint LED light sources 18Z arranged at the ends of adjacent lighting devices 10 are also arranged at equal intervals along the third direction D3. By adopting such an arrangement, the boundary between two adjacent lighting devices 10 becomes even less noticeable.

[0082] Although the embodiments and modifications of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and modifications and can be implemented in various forms without departing from the spirit of the present disclosure. Furthermore, the components disclosed in the above embodiments and modifications can be modified as appropriate. For example, some of the components shown in one embodiment or modification may be added to the components of another embodiment or modification, or some of the components shown in one embodiment or modification may be deleted from that embodiment or modification.

[0083] Furthermore, the drawings mainly show each component in a schematic manner to facilitate understanding of the invention, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of creating the drawings. Furthermore, the configurations of each component shown in the above embodiment and modified examples are merely examples and are not particularly limited, and it goes without saying that various modifications are possible within a scope that does not substantially deviate from the effects of the present disclosure. [Explanation of symbols]

[0084] 10: Lighting device (lighting tube) 11: Circuit board 11A, 11B, 13C2A, 13C2B, 14B: Surface 12:LED light source 13: Heat sink 13A: Support part 13B: Heat dissipation fin 13C:Protrusion 13C1: First extension section 13C1T, 13C21, 13C22: End 13C2:Second extension section 13C3, 18A1: Convex part 13D: Reflector cover 14:Reflector 14A: Reflective surface 14X:Reflector 15: Power supply 16, 18X: Internal space 17: Body 17X: Centroid 18: Joint part 18A: Lid 18B: Inset part 18Y: Translucent part 18Z: LED light source for joint 19: Connector 19A: Input connector 19B: Transition connector 21: Input cable 22: Crossover cable 100: Lighting tube D1: First direction D2:Second direction D3: Third direction

Claims

1. A substrate; an LED light source disposed on the first direction side of the substrate so as to irradiate light in the first direction; a reflector disposed on the first direction side of the substrate and having a reflecting surface that reflects light from the LED light source; a heat sink; a surface of the reflector opposite to the reflecting surface that is in contact with the heat sink;

2. The heat sink is a support portion in contact with a surface of the substrate opposite to the first direction side; a protrusion located at an end of the substrate and protruding from the support portion toward the first direction, The protrusion is a first extension portion extending from the support portion toward the first direction; a second extension portion extending in a direction along the reflecting surface, The lighting device according to claim 1 , wherein a surface of the reflector opposite to the reflecting surface is in contact with the second extension portion.

3. The lighting device according to claim 2 , wherein the reflector continuously covers a surface of the second extension portion on the side facing the first direction to a surface of the second extension portion on the side facing the first direction.

4. The heat sink further includes a reflector cover portion, The lighting device according to claim 1 , wherein the reflector cover is disposed on a side of the reflector opposite to a reflection direction of the light reflected by the reflector.

5. 5. The lighting device according to claim 1, which is a lighting device for growing plants.

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