Lighting tube

Abstract

To provide a lighting tube which can efficiently radiate light to an object.SOLUTION: A lighting tube includes: a substrate; an LED light source which is disposed on a first direction side of the substrate so that light is radiated in a first direction; a pair of reflection parts which are disposed at the first direction side of the substrate and reflects light from the LED light source; and a tube body which houses the substrate, the LED light source, and the pair of reflection parts. In a cross sectional view of the tube body, the LED light source is disposed on the first direction side relative to a centroid of the tube body.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The following disclosure relates to lighting tubes. [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 a lighting tube that can efficiently irradiate an object with light. [Means for solving the problem]

[0005] The lighting tube of the present disclosure comprises 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 pair of reflecting portions arranged on the first direction side of the substrate and reflecting light from the LED light source, and a tube body that houses the substrate, the LED light source, and the pair of reflecting portions, and in a cross-sectional view of the tube body, it is preferable that the LED light source be arranged on the first direction side of the centroid of the tube body. [Effects of the Invention]

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

[0007] [Figure 1]1 is a perspective view of a lighting tube 100 according to a first embodiment. [Figure 2] 1 is a perspective view showing the internal structure of an illumination tube 100 of a first embodiment. [Figure 3] 1 is an enlarged perspective view showing the internal structure of the lighting tube 100 of the first embodiment. [Figure 4] 2 is a cross-sectional view of the lighting tube 100 of the first embodiment taken along the line A1-A2 of FIG. 1. [Figure 5] 1 is a perspective view showing the internal structure of an end portion of the lighting tube 100 of the first embodiment. [Figure 6] 1 is a perspective view showing the internal structure of a joint portion provided in the lighting tube 100 of the first embodiment. [Figure 7] 1 is a longitudinal cross-sectional view showing the internal structure of an end portion of the lighting tube 100 of the first embodiment. [Figure 8] FIG. 10 is a perspective view for explaining a mode in which a cable is connected to the lighting tube 100 of the second embodiment. [Figure 9] FIG. 10 is a perspective view showing a state in which a plurality of lighting tubes 100 of the second embodiment are connected together. [Figure 10] 10 is a longitudinal cross-sectional view showing a state in which a plurality of lighting tubes 100 of the second embodiment are connected together. FIG. [Figure 11] FIG. 10 is an enlarged cross-sectional view of a modified lighting tube 100 in which the heat sink is provided with a second extension portion. [Figure 12] 10 is an enlarged cross-sectional view of a modified lighting tube 100 in which the heat sink does not include a second extension portion. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of a lighting tube 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 modifications can be made within the scope of the configuration of the present disclosure. In the drawings, identical or equivalent elements are designated by 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 a lighting tube 100 of embodiment 1. Fig. 2 is a perspective view showing the internal structure of the lighting tube 100 of embodiment 1. Fig. 3 is an enlarged perspective view showing the internal structure of the lighting tube 100 of embodiment 1. Fig. 4 is a cross-sectional view of the lighting tube 100 of embodiment 1 taken along line A1-A2 in Fig. 1.

[0011] An illumination tube 100 of this embodiment will be described with reference to FIGS. 1 to 4. The illumination tube 100 of this embodiment is a type of lighting device 10. As shown in FIGS. 1 to 4, the illumination tube 100 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 reflecting portion 14X arranged on the first direction D1 side of the substrate 11 and reflecting the light from the LED light source 12. In this embodiment, the illumination tube 100 can reflect the light irradiated from the LED light source 12 in the first direction D1 by the reflecting portion 14X, and can efficiently irradiate light onto an object located on the first direction D1 side of the illumination tube 100.

[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 (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 tubes for plant growth are required to efficiently irradiate only the plants with the amount of light necessary for plant growth. However, conventional lighting tubes for plant growth simply project the light emitted from the LED light source outward, irradiating 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 tube 100 of this embodiment is arranged on the first direction D1 side of the substrate 11 and is equipped with 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 was conventionally emitted in the 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 tube 100 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 irradiated surface directly below the LED light source 12 and in the surrounding space, etc. Therefore, the lighting tube 100 of this embodiment can be suitably used as a lighting tube for growing plants.

[0015] Furthermore, in the lighting tube 100 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 surface of the lighting tube 100, and therefore it is possible to prevent the lighting tube 100 itself from becoming hot, and it also has an excellent heat dissipation effect. The lighting tube 100 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 tube 100 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 the center 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 tube 100 preferably includes a heat sink 13. The lighting tube 100 of this embodiment can dissipate heat generated from the substrate 11, the LED light source 12, etc. by the heat sink 13. The heat sink 13 includes 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. The lighting tube 100 of this embodiment can stably fix the heat sink 13, thereby more effectively achieving the effects of the heat sink 13. The support portion 13A preferably extends 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 opposite direction to the first direction D1. In 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 tube 100 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 provided with protrusions 13C located at the end of the substrate 11 and protruding from the support 13A toward the first direction D1. In the lighting tube 100 of this embodiment, the substrate 11 can be held by the support 13A and the protrusions 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 tube 100. 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 tube 100. 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 extending 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 tube 100 of this embodiment, the reflecting portion 14X can reflect the light emitted from the LED light source 12 in the first direction D1 side, and the lighting tube 100 can efficiently irradiate the light to an object located on the first direction D1 side of the lighting tube 100.

[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 tube 100 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, the angle α between the reflecting portion 14X and the first direction D1 in a cross-sectional view (a cross-section viewed from the third direction D3) 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 tube 100 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 tube 100 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 to the first direction D1 of the substrate 11. By adopting such an embodiment, the power supply 15 is disposed at a position that does not interfere with the LED light source 12, so that the lighting tube 100 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] As shown in Fig. 4, the lighting tube 100 preferably includes a tube body 17 that houses the substrate 11, the LED light source 12, and the reflecting portion 14X. The tube body 17 has an internal space 16 that can house the substrate 11, the LED light source 12, and the reflecting portion 14X. As shown in Fig. 1, the tube body 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 the end portion of the lighting tube 100 of embodiment 1. Fig. 6 is a perspective view showing the internal structure of a joint portion provided in the lighting tube 100 of embodiment 1. Fig. 7 is a longitudinal cross-sectional view showing the internal structure of the end portion of the lighting tube 100 of embodiment 1.

[0037] 5 to 7, the lighting tube 100 preferably includes a joint portion 18 that closes the ends (preferably both ends) of the tube 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 tube body 17 side is open and the end opposite the tube 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 light tube 100 preferably includes a connector 19 to which an electrical cable can be connected.

[0041] (Embodiment 2) As shown in Fig. 4, the lighting tube 100 of this embodiment is a lighting tube 100 having a tube body 17 and includes a pair of reflecting portions 14X of the first embodiment. Specifically, the lighting tube 100 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 pair of reflecting portions 14X arranged on the first direction D1 side of the substrate 11 and reflecting light from the LED light source 12, and a tube body 17 that houses the substrate 11, the LED light source 12, and the pair of reflecting portions 14X. This configuration changes the irradiation angle of the light irradiated from the LED light source 12, and the lighting tube 100 can distribute light that has conventionally been irradiated in a horizontal direction or the like within an area sandwiched between the pair of reflecting portions 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.

[0042] 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.

[0043] Furthermore, in the lighting tube 100 of this embodiment, 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 tube 100 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 tube 100 can more efficiently irradiate light to 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.

[0044] 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.

[0045] The lighting tube 100 of this embodiment is, for example, a straight-tube type LED lighting tube. The overall length of the lighting tube 100 is the same as that of a conventional straight-tube type fluorescent lamp, and can be appropriately set to, for example, 600 mm, 900 mm, 1200 mm, 1800 mm, 2400 mm, etc. depending on the application. In addition, the tube diameter of the lighting tube 100 is approximately the same as that of a conventional straight-tube type fluorescent lamp, and the lighting tube 100 has an outer shape and appearance that are approximately the same as those of a straight-tube type fluorescent lamp overall.

[0046] In a cross-sectional view of the tube body 17, it is preferable that the substrate 11 (specifically, the entire substrate 11) is disposed closer to the first direction D1 than the centroid 17X of the tube body 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 body 17 from the first direction D1. As a result, components included in the lighting tube 100 (for example, the heat dissipation fins 13B of the heat sink 13 and the power source 15) can be stored in the 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 tube 100.

[0047] In a cross-sectional view of the tube 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 tube 17. In the lighting tube 100 of this embodiment, it is possible to increase the space on the opposite side of 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 closer to the first direction D1 than the centroid 17X of the tube 17. As a result, components of the lighting tube 100 (for example, the heat dissipation fins 13B of the heat sink 13 and the power source 15) can be stored in the space on the opposite side of 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 tube 100.

[0048] The lighting tube 100 further includes a heat sink 13. The heat sink 13 preferably includes a support portion 13A in contact with a surface 11B of the substrate 11 opposite to the first direction D1, and a pair of protrusions 13C located at both ends of the substrate 11 and protruding from the support portion 13A in the first direction D1, and the pair of protrusions 13C hold the pair of reflecting portions 14X. The lighting tube 100 of this embodiment can stably hold the heat sink 13 and the pair of reflecting portions 14X (for example, the pair of reflecting portions 14X and the heat sink 13 are integrated) without using adhesive, making it easy to assemble the lighting tube 100. The pair of protrusions 13C are located at both ends of the substrate 11 in the second direction D2.

[0049] It is preferable that 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 tube 100 can stably hold the heat sink 13 and the pair of reflecting portions 14X without using adhesive. It is more preferable that 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).

[0050] 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 held more stably without the use of adhesive, making it easier to assemble the lighting tube 100.

[0051] 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.

[0052] In a cross-sectional view of the tube 17, it is preferable that an end 13C21 of the second extension portion 13C2 facing outward from the tube 17 is located closer to the first direction D1 than an end 13C22 of the second extension portion 13C2 facing inward from the tube 17. By adopting such an embodiment, 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, so that the lighting tube 100 can more effectively irradiate light to an object (specifically, a plant) located on the first direction D1 side.

[0053] The pair of reflecting portions 14X are preferably arranged so as to face the LED light source 12 side along the third direction D3 (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 tube 100 can more efficiently irradiate light to an object located on the first direction D1 side.

[0054] In a cross-sectional view of the tube body 17, it is preferable that each reflecting portion 14X (specifically, the entire reflecting portion 14X) is disposed closer to the first direction D1 than the centroid 17X of the tube body 17. By adopting such an embodiment, the length of each reflecting portion 14X can be shorter than when each reflecting portion is disposed on the opposite side to the first direction, and therefore the internal structure of the lighting tube 100 can be further simplified. As a result, the manufacturing cost of the lighting tube 100 can be reduced.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] The lighting tube 100 includes a joint portion 18 that closes the end of the tube body 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 in a cross-sectional view of the tube body 17. 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 tube 100 of this embodiment 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 tube 100 to improve light utilization efficiency and more efficiently irradiate light onto an object.

[0059] The lighting tube 100 includes a connector 19 to which an electric cable can be connected, and the pair of reflecting portions 14X are preferably arranged at both ends of the substrate 11 in the second direction D2, with the connector 19 being arranged 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, so that when a plurality of lighting tubes 100 are connected in the third direction D3, seamless connection can be achieved. The connector 19 is arranged, for example, in the joint portion 18 (specifically, the cover portion 18A).

[0060] The lighting tube 100 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 reflecting portion 14X on the first direction D1 side in a cross-sectional view of the tube body 17. To prevent the 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 tube 100 of this embodiment includes the reflecting portion 14X, if the connector 19 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 lighting tube 100 can prevent the light emitted from the LED light source 12 from being blocked by the connector 19. This increases the light utilization efficiency and enables the lighting tube 100 to more efficiently irradiate the object with light.

[0061] The lighting tube 100 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 tube 100 of this type 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.

[0062] Fig. 8 is a perspective view for explaining how a cable is connected to the lighting tube 100 of embodiment 2. Fig. 9 is a perspective view showing a state in which a plurality of lighting tubes 100 of embodiment 2 are connected together. Fig. 10 is a longitudinal cross-sectional view showing a state in which a plurality of lighting tubes 100 of embodiment 2 are connected together.

[0063] As shown in FIGS. 8 to 10 , one of the connectors 19 arranged at both ends of the lighting tube 100 may be an input connector 19A to which current is input from outside the lighting tube 100. An input cable 21 for AC 100V, for example, 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 tubes 100. An AC 100V transition cable 22, for example, is connected to the transition connector 19B. By connecting the transition connector 19B of one of the two adjacent lighting tubes 100 to the transition connector 19B of the other lighting tube 100 with the transition cable 22, multiple lighting tubes 100 can be connected in the third direction D3 (longitudinal direction).

[0064] 8 to 10, the lighting tube 100 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 tubes 100 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 realizing seamless light emission in which the boundary between two adjacent lighting tubes 100 is not noticeable.

[0065] 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.

[0066] The lighting tube 100 preferably includes a plurality of LED light sources 12, a pair of reflecting portions 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 portion LED light source 18Z are disposed at equal intervals along a third direction D3 perpendicular to the first direction D1 and the second direction D2. By adopting such an embodiment, when a plurality of lighting tubes 100 are connected in the third direction D3 (longitudinal direction), seamless light emission is realized in which the boundary between two adjacent lighting tubes 100 is less noticeable.

[0067] 10, when a plurality of lighting tubes 100 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 tubes 100 are also arranged at equal intervals along the third direction D3. By adopting such an arrangement, the boundary between two adjacent lighting tubes 100 becomes even less noticeable.

[0068] (Variation) 4, the lighting tube 100 of this modification includes a reflector 14 having a reflecting surface 14A, as the reflecting portion 14X in the first or second embodiment. Specifically, the lighting tube 100 of this modification 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 reflecting 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 reflecting surface 14A is in contact with the heat sink 13. The lighting tube 100 of this embodiment can reflect light that has passed through the reflector 14 without being reflected by the reflecting surface 14A, by the heat sink 13, thereby improving light utilization efficiency and enabling light to be more efficiently irradiated onto an object.

[0069] The reflecting 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 reflecting surface 14A in the first direction D1 side, and the lighting tube 100 can efficiently irradiate light onto an object located on the first direction D1 side.

[0070] 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.

[0071] 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.

[0072] Fig. 11 is an enlarged cross-sectional view of a modified lighting tube 100 in which the heat sink includes a second extension portion. As shown in Fig. 11, the heat sink 13 of this modified example includes a support portion 13A in contact with a surface 11B of the substrate 11 opposite the first direction D1, and a protrusion 13C located at an end of the substrate 11 and protruding from the support portion 13A in the first direction D1. The protrusion 13C includes a first extension portion 13C1 extending from the support portion 13A in the first direction D1 and a second extension portion 13C2 extending along the reflecting surface 14A. The surface 14B of the reflector 14 opposite the reflecting surface 14A is preferably in contact with the second extension portion 13C2. The lighting tube 100 of this embodiment allows the second extension portion 13C2 of the heat sink 13 to effectively reflect light that passes through the reflector 14 without being reflected by the reflecting surface 14A. As a result, the lighting tube 100 can effectively improve the light utilization efficiency, and can irradiate the object with light more efficiently.

[0073] Fig. 12 is an enlarged cross-sectional view of a modified lighting tube 100 in which the heat sink does not have a second extension portion. The protrusion 13C of the lighting tube 100 shown in Fig. 12 has a first extension portion 13C1 extending from the support portion 13A toward the first direction D1, and a convex portion 13C3 not extending in the direction along the reflecting surface 14A.

[0074] In the lighting tube 100 shown in Fig. 12 that does not have 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 is not thick enough, 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.

[0075] On the other hand, in the lighting tube 100 having the second extension portion 13C2 shown in Figure 11, 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.

[0076] It is preferable that the reflector 14 continuously covers the second extension portion 13C2 from a surface 13C2A on the first direction D1 side to a surface 13C2B on the opposite side from the first direction D1 side. In the lighting tube 100 of this embodiment, light that passes through the reflector 14 without being reflected by the reflecting surface 14A can be more effectively reflected in the first direction D1 side by the heat sink 13, so that the light utilization efficiency can be more effectively improved and the object can be irradiated with light more efficiently.

[0077] 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.

[0078] 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]

[0079] 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 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 pair of reflecting portions disposed on the first direction side of the substrate and configured to reflect light from the LED light source; a tube that accommodates the substrate, the LED light source, and the pair of reflectors therein; In a cross-sectional view of the tube body, the LED light source is arranged on the first direction side of the centroid of the tube body.

2. The lighting tube further comprises a heat sink; The heat sink is a support portion in contact with a surface of the substrate opposite to the first direction side; a pair of protrusions located at both ends of the substrate and protruding from the support portion toward the first direction, The light tube of claim 1 , wherein the pair of protrusions holds the pair of reflectors.

3. The lighting tube further includes a connector to which an electric cable can be connected. the pair of reflecting portions are disposed at both ends of the substrate in the second direction, The lighting tube according to claim 1 , wherein the connector is disposed to protrude in a plane including the first direction and the second direction.

4. The lighting tube further includes a connector to which an electric cable can be connected. The lighting tube according to claim 1 , wherein the connector is disposed on a side opposite to the first direction side relative to the LED light source in a cross-sectional view of the tube body.

5. The lighting tube further includes a joint portion that closes an end of the tube body, The lighting tube according to claim 1 , wherein the joint portion has a light-transmitting portion at least on the first direction side, and includes an LED light source for the joint portion therein.

6. The lighting tube includes a plurality of the LED light sources, the pair of reflecting portions are disposed at both ends of the substrate in the second direction, The lighting tube according to claim 5 , wherein the plurality of LED light sources and the joint portion LED light source are arranged at equal intervals along a third direction perpendicular to the first direction and the second direction.

7. The lighting tube according to any one of claims 1 to 6, which is a lighting tube for growing plants.

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