Light source

Abstract

To provide a long light source which has a small number of components, can be mass-produced at low cost, and can efficiently emit light over a wide range including both ends in the longitudinal direction of the light source.SOLUTION: A light source 1 includes a translucent cover 10 which is a hard housing formed in a long cylindrical shape, and a long flat plate-like substrate 20 on which an LED element 22 is mounted and which is inserted into an internal space of the translucent cover 10. A power supply component 23 for supplying power to the LED element 22 is mounted on the back surface of the substrate 20. The translucent cover 10 has a cylindrical wall integrally molded by a translucent resin, and is constituted so that the substrate 20 can be inserted from an axial end part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a light source, and more particularly to an elongated light source including an LED element. [Background technology]

[0002] Conventionally, straight tube fluorescent lamps have been widely used as long light sources, but in recent years they have been increasingly replaced by LED light sources including LED elements. A long LED light source generally comprises a long LED board on which LED elements are mounted, and a housing that houses the LED board (see, for example, Patent Documents 1 to 5). The housing includes, for example, a long cylindrical translucent cover that covers the LED board.

[0003] Patent documents 1 and 2 disclose LED light sources having a rectangular cylindrical housing formed by assembling multiple cover members. Patent documents 3 and 4 disclose LED light sources having an integrally molded cylindrical housing. In the light sources of Patent documents 3 and 4, the LED board is fixed to the housing by intermittently applying adhesive between the back surface of the LED board and the inner wall of the housing. Multiple LED elements are mounted on the surface of the board, and circuit components are mounted on the longitudinal ends. Patent document 5 discloses a flexible strip-shaped LED light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-85212 [Patent Document 2] Japanese Patent Application Publication No. 2018-185908 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-35285 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-149168 [Patent Document 5] Japanese Patent Application Laid-Open No. 2015-195204 Summary of the Invention [Problem to be solved by the invention]

[0005] Since long LED light sources are expected to become widespread as replacements for straight-tube fluorescent lamps, it is desirable for them to have a simple structure with a small number of parts and be mass-produced at low cost. Long LED light sources are also required to be able to efficiently emit light over a wide range, including both ends in the longitudinal direction of the light source. [Means for solving the problem]

[0006] The light source according to the present disclosure comprises a rigid housing formed in a long cylindrical shape, and a long, flat substrate having an LED element mounted on its surface and inserted into the internal space of the housing, with a power supply component mounted on the back surface of the substrate for supplying power to the LED element, and the housing has a cylindrical wall integrally molded from a translucent resin and is configured so that the substrate can be inserted from the axial end. [Effects of the Invention]

[0007] The light source according to the present disclosure has a simple structure with a small number of parts, can be mass-produced at low cost, and can efficiently emit light over a wide range, including both ends of the light source in the longitudinal direction. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a light source according to an embodiment, showing a state in which a mounting fixture is attached to an outer groove of a housing. [Figure 2] 1 is an exploded perspective view of a light source with a fixture according to an embodiment; [Figure 3] 3 is an enlarged view of an end portion in the longitudinal direction of an LED substrate that is an example of an embodiment. FIG. [Figure 4] 1 is a widthwise cross-sectional view of a light source with a fixture according to an embodiment of the present invention; [Figure 5] FIG. 1 is a perspective view of a mounting fixture according to an embodiment. [Figure 6] FIG. 2 is a cross-sectional view showing an example of an attachment form of a light source according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of a light source and a fixture according to the present disclosure will be described in detail with reference to the drawings. The embodiments described below are merely examples, and the present invention is not limited to the following embodiments. Furthermore, forms formed by selectively combining multiple embodiments and modifications described below are included within the scope of the present disclosure.

[0010] Fig. 1 is a perspective view of a light source 1, which is an example of an embodiment. Fig. 1 illustrates a state in which a fixture 40, which is an example of an embodiment, is attached to an outer groove 12 of a light-transmitting cover 10, which is a housing of the light source 1 (hereinafter, sometimes referred to as "light source 1 with fixture"). Fig. 2 is an exploded perspective view of the light source 1 with fixture (side cover 30 is not shown).

[0011] As shown in FIGS. 1 and 2, the light source 1 includes a translucent cover 10 formed in a long cylindrical shape, and a long, flat substrate 20 inserted into the internal space of the translucent cover 10. The translucent cover 10 is a hard housing that houses the substrate 20. An inner groove 11 into which both widthwise ends of the substrate 20 are inserted is formed over the entire axial length on the inner surface of the translucent cover 10, and an outer groove 12 into which a mounting fixture 40 fits is formed over the entire axial length on the outer surface of the translucent cover 10 on the back side of the substrate 20. The substrate 20 is an LED substrate on which LED elements 22 are mounted on the front surface and on which power supply components 23 that supply power to the LED elements 22 are mounted on the back surface.

[0012] As will be described in detail later, the light-transmitting cover 10 has a cylindrical wall integrally molded from a light-transmitting resin, and is configured so that the substrate 20 can be inserted from the axial end (longitudinal end). The light-transmitting cover 10 can be a glass cover, but is preferably a resin cover from the viewpoints of productivity, light weight, etc. The axial direction and longitudinal direction of the light-transmitting cover 10 refer to the same direction.

[0013] The light source 1 is fixed to a mounting surface using a fixture 40. The light source 1 is expected to become widely used as a replacement for straight tube fluorescent lamps, and can be used as a light source for existing lighting fixtures. In this case, the mounting surface of the light source 1 is the surface of the lighting fixture body. The use of the light source 1 is not particularly limited, but it can be used as a lighting fixture installed in a bathroom sink, kitchen, storage room, etc. Furthermore, the light source 1 can be directly mounted to a ceiling, wall, etc., and used as a lighting fixture by itself. The fixture 40 can directly fix the light source 1 to a ceiling, wall, etc. As will be described in detail later, the fixture 40 can also be used to fix the light source 1 to a wall, etc., with the longitudinal direction of the light source 1 aligned vertically.

[0014] The light source 1 is an elongated LED light source including a plurality of LED elements 22, and is configured to efficiently emit light over a wide range including both longitudinal ends. No power supply components 23 are arranged on the surface of the substrate 20, and the LED elements 22 are arranged up to the vicinity of both longitudinal ends of the substrate 20. Furthermore, since both axial ends of the translucent cover 10 are open, the light source 1 is provided with side covers 30 as lids to cover the openings, but the side covers 30 hardly cover the surface of the translucent cover 10. Therefore, the light source 1 can efficiently emit light over almost its entire length.

[0015] As described above, the light source 1 includes a hard, light-transmitting cover 10 as a housing for accommodating the substrate 20. Here, "hard" means that it is not flexible and does not deform during use, installation, etc., in other words, it is not flexible. Because the light-transmitting cover 10 is hard and has excellent shape stability, it functions as a protective cover for the substrate 20 and also makes it easy to attach the light source 1 to a lighting fixture. The light-transmitting cover 10 can be manufactured to any length by extrusion molding, making it easy to manufacture multiple types of light source 1 with different lengths. Furthermore, the light source 1 has a simple structure with a small number of parts, allowing for low-cost mass production.

[0016] The fixture 40 for fixing the light source 1 to the mounting surface is fitted into a pair of outer grooves 12 formed on the back surface of the substrate 20 along the longitudinal direction of the light-transmitting cover 10 and includes a pair of clamping portions 41 that hold the cover by elastic force, and a fixing portion 42 that is molded integrally with the clamping portions 41 and fixed to the mounting surface. The fixture 40 is formed into a roughly U-shape overall, with the clamping portions 41 extending in the same direction from both sides of the fixing portion 42. The spacing between the clamping portions 41 is slightly smaller than the width of the light-transmitting cover 10.

[0017] The fixture 40 holds the light source 1 by utilizing the outer groove 12 of the light-transmitting cover 10. In other words, the light source 1 has an outer groove 12 formed on the outer surface of the light-transmitting cover 10 as a structure for attaching the fixture 40. The pair of clamping portions 41 are elastically deformable in the width direction of the light-transmitting cover 10, which is the direction in which the clamping portions 41 are aligned, and function as springs that apply elastic force to the outer surface of the light-transmitting cover 10. As will be described in detail later, the clamping portions 41 hold the light-transmitting cover 10 by an elastic force that allows the light source 1 to slide in the longitudinal direction of the light-transmitting cover 10 and prevents the light source 1 from sliding due to its own weight, for example.

[0018] The mounting fixture 40 is preferably a metal fitting made of a single metal plate. Although the mounting fixture 40 can be made of resin, it is preferably made of metal from the standpoint of durability and the like. The clamping portion 41 and fixing portion 42 of the mounting fixture 40 are formed by bending a single metal plate. The mounting fixture 40 is fixed to the mounting surface using, for example, a screw, and therefore a screw insertion hole 43 is formed in the fixing portion 42. The clamping portion 41 also has a protrusion 44 formed by bending the metal plate at a right angle or an acute angle. The protrusion 44 has a shape that protrudes toward the light-transmitting cover 10 and is formed in a position that fits into the outer groove 12.

[0019] The light source 1 is fixed to the mounting surface by fitting a mounting fixture 40, which is screwed to the mounting surface, into the outer groove 12 of the translucent cover 10. Because the outer groove 12 is formed over the entire length of the translucent cover 10, the clamping portion 41 can be slid and inserted into the outer groove 12 from both longitudinal ends. However, because the clamping portion 41 is elastically deformable in the width direction of the translucent cover 10, the clamping portion 41 can be spread outward and fitted into the outer groove 12 from the middle of the translucent cover 10. The number of mounting fixtures 40 that hold the light source 1 is not particularly limited, but two or more is preferable from the perspective of stability of the light source 1, etc. The number of mounting fixtures 40 attached to one light source 1 is, for example, two or more and four or less. The number and arrangement of the mounting fixtures 40 can be changed as appropriate depending on the length of the light source 1, the shape of the mounting surface, etc.

[0020] The light source 1 includes side covers 30 attached to both axial ends of the light-transmitting cover 10. The side covers 30 are lids that cover openings formed at both axial ends of the light-transmitting cover 10, have a shape corresponding to the opening of the light-transmitting cover 10, and cover the entire opening. The side covers 30 also have insertion holes 31 for a power line 35 that supplies AC power to the power supply component 23. The light source 1 incorporates the power supply component 23 that converts AC power to DC power, so the power line 35 that supplies AC power can be directly connected. The power line 35 is introduced into the light-transmitting cover 10 through the insertion holes 31 in the side covers 30 and connected to a terminal (not shown) provided on the substrate 20.

[0021] Although a portion of the surface of the light-transmitting cover 10 is covered by the side cover 30, it is preferable that the overlapping range of the side cover 30 is small because the LED elements 22 are arranged close to both longitudinal ends of the cover. The overlap width between the light-transmitting cover 10 and the side cover 30 is, for example, 3 mm or less. There are no particular limitations on the method for fastening the side cover 30, but in this embodiment, locking holes 15 are formed at both longitudinal ends of the light-transmitting cover 10, and the side cover 30 is fixed to the light-transmitting cover 10 by fitting the claws 32 (see FIG. 3 described below) of the side cover 30 into the locking holes 15.

[0022] The locking holes 15 are formed in the outer groove 12, penetrating the translucent cover 10 in the thickness direction. In this case, the fixing structure of the side cover 30 does not affect the light emitted from the light source 1. A total of four locking holes 15 are formed in the outer groove 12 on both sides in the width direction at both longitudinal end portions of the translucent cover 10.

[0023] As described above, the translucent cover 10 has an inner groove 11 formed therein. As will be described in detail later, the inner groove 11 is a holding groove for the substrate 20 into which both widthwise ends of the substrate 20 are inserted, and is formed by a first convex portion 13 and a second convex portion 14 that protrude into the internal space of the translucent cover 10. The second convex portion 14 is formed inside the outer groove 12 by the outer groove 12 being recessed inside the translucent cover 10. The second convex portion 14 constitutes part of the inner groove 11, and also functions as a shielding portion that covers both widthwise ends of the back surface of the substrate 20 to prevent light from leaking to the back surface side.

[0024] The structure of the substrate 20 will be described in further detail below with reference to Fig. 3. Fig. 3 is an enlarged view of an end portion of the substrate 20 in the longitudinal direction.

[0025] As shown in Fig. 3, the substrate 20 includes a long, flat base 21, an LED element 22 mounted on a first surface (front side) of the base 21, and a power supply component 23 mounted on a second surface (back side) of the base 21. The power supply component 23 is disposed only on the back side of the base 21 opposite the LED element 22. In this case, the light emitted from the LED element 22 is not blocked by the power supply component 23. Furthermore, there is no need to secure a mounting space for the power supply component 23 on the front side of the base 21, and the LED element 22 can be disposed up to the vicinity of both ends of the base 21 in the longitudinal direction.

[0026] The base 21 is a flat plate whose front and back surfaces are substantially parallel to each other and has a length equal to or slightly shorter than that of the light-transmitting cover 10. For example, the length of the base 21 is 90% to 100% of the length of the light-transmitting cover 10, and the thickness of the base 21 is 1.0 mm to 3.0 mm. A terminal (not shown) is provided at a longitudinal end of the base 21, and a power line 35 introduced through an insertion hole 31 in the side cover 30 is connected to the terminal. The side cover 30 has a claw 32 that is inserted into the internal space of the light-transmitting cover 10 and fits into the locking hole 15 from the inside of the cover. The claw 32 is located only on the back side of the base 21 and does not affect the light emitted from the LED element 22. The side cover 30 may be fixed to the base 21.

[0027] The LED elements 22 are mounted at predetermined intervals along the longitudinal direction of the base 21. Conventionally known elements can be used for the LED elements 22. The LED elements 22 can be arranged in two or more rows along the longitudinal direction of the base 21, but in this embodiment, they are arranged in a single row. The predetermined intervals between the LED elements 22 are preferably substantially constant. Suitable examples of the predetermined intervals are 10 mm to 80 mm, 20 mm to 80 mm, 30 mm to 80 mm, or 40 mm to 70 mm. In this case, heat generation from the substrate 20 is sufficiently suppressed, eliminating the need for a heat sink for heat radiation. Therefore, the light source 1 does not have a heat sink, and no heat sink is provided within the translucent cover 10.

[0028] As described above, the LED elements 22 are also arranged at both longitudinal ends of the base 21. The distance between one longitudinal end of the base 21 and the LED element 22 closest to that end is smaller than the distance between the LED elements 22, and is, for example, 10 mm or more and 25 mm or less (the same applies to the other longitudinal end of the base 21). Furthermore, the light source 1 is designed so that the overlap width between the translucent cover 10 and the side cover 30 is small, so that light can be efficiently emitted over substantially the entire length of the light source 1. The number of LED elements 22 included in one substrate 20 is not particularly limited and can be changed as appropriate depending on the length of the light source 1.

[0029] In this embodiment, the light output of the light source 1 is 400 lm or more, more preferably 1200 lm or more, and the luminous efficiency is 110 lm / W or more. The light output of the light source 1 is set, for example, between 400 lm and 4000 lm, or between 1200 lm and 4000 lm. The power consumption per unit length of the light source 1 is preferably 1.0 W / cm or less, more preferably 0.5 W / cm or less, particularly preferably 0.3 W / cm or less, and even more preferably 0.2 W / cm or less. In this case, heat generation from the substrate 20 is not a problem even without a heat sink.

[0030] The power supply components 23 have the function of converting AC current from a commercial power source into DC current for lighting the LED elements 22. The power supply components 23 include multiple components, such as a switching element, a choke coil, and a capacitor. Because the power supply components 23 are taller than the LED elements 22, a space capable of accommodating the power supply components 23 is provided on the rear surface side of the substrate 20 within the interior space of the translucent cover 10. Because the power supply components 23 generate heat when driven, they are dispersed and arranged over a length range equivalent to, for example, twice the distance D between the LED elements 22. In this embodiment, the power supply components 23 are arranged at appropriate intervals from one longitudinal end of the base 21 to the third LED element 22.

[0031] The configuration of the light-transmitting cover 10 will be described in further detail below with reference to Fig. 4. Fig. 4 is a widthwise cross-sectional view of the light source with mounting fixture 1. For ease of explanation, the direction in which the front surface of the base 21 on which the LED elements 22 are mounted faces will be referred to as the "front," and the direction in which the back surface of the base 21 on which the power supply components 23 are mounted faces will be referred to as the "rear."

[0032] As shown in Fig. 4, the light-transmitting cover 10 has a front surface 10a that is curved outwardly convex, a rear surface 10b that is formed substantially flat, and a pair of side surfaces 10c that connect the widthwise ends of the front surface 10a and the rear surface 10b. The side surfaces 10c are formed substantially perpendicular to the rear surface 10b, but the boundary between the rear surface 10b and the side surfaces 10c is chamfered. The front surface 10a, the rear surface 10b, and the pair of side surfaces 10c are integrally molded from a light-transmitting resin and form the cylindrical wall of the light-transmitting cover 10. Note that Fig. 4 shows the light-transmitting cover 10 held by a mounting fixture 40 that is screwed to a mounting surface 50.

[0033] As described above, the translucent cover 10 is manufactured by extrusion molding of a translucent resin. In this case, the length of the translucent cover 10 can be adjusted as desired, allowing products of different lengths to be easily manufactured at low cost. The integrally molded translucent cover 10 eliminates the need for assembly of multiple parts, which occurs when a cover is composed of multiple parts, significantly contributing to reduced manufacturing costs. The translucent cover 10 also has high mechanical strength and is resistant to impacts. The thickness of the translucent cover 10 is not particularly limited, but is, for example, 1.0 mm or more and 3.0 mm or less in the areas where no protrusions or the like are present.

[0034] The light-transmitting cover 10 can be formed by two-color molding, for example, using different materials for the front portion 10a and other portions. However, from the viewpoint of cost reduction, it is preferable that the entire cover be made of the same material. The light-transmitting resin that forms the light-transmitting cover 10 is not particularly limited, but examples of suitable resins include polycarbonate and acrylic resin. The light-transmitting cover 10 is, for example, colorless, transparent, or milky white. The light-transmitting cover 10 may contain additives such as pigments as long as they do not impair the desired light-transmitting properties.

[0035] The light-transmitting cover 10 has a pair of inner grooves 11 formed on the inner surface of the side surface portion 10c and a pair of outer grooves 12 formed on the outer surface of the side surface portion 10c. The inner grooves 11 and the outer grooves 12 are formed over the entire axial length of the light-transmitting cover 10 (see FIG. 2). The pair of inner grooves 11 are formed at positions opposite each other in the width direction of the light-transmitting cover 10, and the pair of outer grooves 12 are similarly formed at positions opposite each other in the width direction of the cover. The inner grooves 11 are located closer to the front surface portion 10a than the outer grooves 12. The outer grooves 12 are formed wider than the inner grooves 11 in a portion including the center of the light-transmitting cover 10 in the front-rear direction. The inner grooves 11 and the outer grooves 12 are adjacently disposed in the front-rear direction, and a second convex portion 14 on the inner surface formed by the outer grooves 12 constitutes part of the inner groove 11.

[0036] The inner groove 11 is a holding groove for the substrate 20 into which both widthwise ends of the substrate 20 (base portion 21) are inserted, and is formed by a first protrusion 13 and a second protrusion 14. The first protrusion 13 and the second protrusion 14 are protrusions that protrude in the widthwise direction from the inner surface of the side portion 10c and are formed over the entire axial length of the cover. The first protrusion 13 and the second protrusion 14 are formed with a gap in the front-rear direction of the translucent cover 10 that allows the base portion 21 of the substrate 20 to be inserted. The substrate 20 can be inserted between the first protrusion 13 and the second protrusion 14, i.e., into the inner groove 11, from openings at both axial ends of the translucent cover 10. The substrate 20 is held in the inner groove 11 with the surface of the base portion 21, on which the LED elements 22 are mounted, facing the front surface 10a.

[0037] The inner groove 11 is formed closer to the front surface 10a than the center of the translucent cover 10 in the front-rear direction. This ensures that the internal space of the translucent cover 10 has sufficient space to accommodate the power supply components 23 mounted on the back surface of the base 21. The first protrusions 13 forming the inner groove 11 cover part of the surface of the base 21, but their tips are far away from the center of the base 21 in the width direction where the LED elements 22 are arranged, and do not affect the light emitted from the LED elements 22. The pair of first protrusions 13 have, for example, the same shape and size, and cover a length range of 3% to 20% of the width of the base 21 from both ends of the base 21 in the width direction. In this case, the substrate 20 can be stably held without blocking the light emitted from the LED elements 22.

[0038] As described above, the second convex portion 14 is formed by recessing the outer groove 12 into the inside of the light-transmitting cover 10. By forming the inner groove 11 using the outer groove 12 into which the mounting fixture 40 fits, the light-transmitting cover 10 can be made smaller and less expensive. The second convex portion 14 covers both widthwise ends of the back surface of the base 21 and abuts against the back surface of the base 21 at least when the back surface of the base 21 faces vertically downward. Note that when the light source 1 is fixed to the mounting surface 50, the back surface of the base 21 often faces vertically upward or horizontally. In this case, too, it is preferable that there is no large gap between the back surface of the base 21 and the second convex portion 14, and the back surface of the base 21 and the second convex portion 14 may be in substantial contact.

[0039] The second convex portions 14 function as shielding portions that cover the back surface of the base 21 at both widthwise ends of the base 21 and prevent light from leaking toward the rear surface portion 10b. The presence of the second convex portions 14 effectively prevents light from circulating around the back surface of the base 21, and the side surface portion 10c clearly shows a difference in brightness across the inner groove 11. In other words, the light emitted from the LED element 22 is emitted to the outside only from the front surface portion 10a of the translucent cover 10 and from the portion of the side surface portion 10c that is located closer to the front surface portion 10a than the inner groove 11. In this case, light can be extracted efficiently from the light source 1. Furthermore, the clear boundary between brightness and darkness allows for a neat and tidy appearance.

[0040] The width (length in the front-to-rear direction) of the inner groove 11, i.e., the distance between the first protrusion 13 and the second protrusion 14, is slightly larger than the thickness of the base 21 at the narrowest part of the range where the base 21 is inserted, and is preferably 1.5 times or less, and more preferably 1.3 times or less, the thickness of the base 21. A suitable width of the inner groove 11 is, for example, 1.1 to 1.3 times the thickness of the base 21, and is constant over the entire length of the inner groove 11. If the width of the inner groove 11 is within this range, the substrate 20 can be inserted into the inner groove 11 without any problems, and the substrate 20 is stably held. In addition, the shielding effect of the second protrusion 14 becomes more pronounced.

[0041] The surface of the first protrusion 13 facing the front surface of the base 21 is inclined so as to gradually move away from the front surface of the base 21 toward the tip of the first protrusion 13, but the surface of the second protrusion 14 facing the back surface of the base 21 has a region that extends approximately parallel to the back surface of the base 21. The surface of the second protrusion 14 facing the back surface of the base 21 includes a larger region that is aligned with the surface direction of the base 21 than the surface of the first protrusion 13 facing the front surface of the base 21. In this case, the shielding effect of the second protrusion 14 becomes more pronounced.

[0042] The outer groove 12 is recessed in a portion of the side surface portion 10c that is closer to the rear surface portion 10b than the back surface of the base portion 21, which is held in the inner groove 11. The outer groove 12 is formed with a depth that allows the clamping portion 41 of the mounting fixture 40 to fit securely and the mounting fixture 40 to clamp the light-transmitting cover 10. The outer groove 12 has an angular shape to facilitate the clamping portion 41 to be easily caught, and the groove bottom is formed to be approximately flat. The depth of the outer groove 12 is, for example, 1.0 mm or more and 3.0 mm or less at its deepest portion, and is constant along its entire length. In this case, the mounting fixture 40 stably holds the light-transmitting cover 10, the shielding function of the second protrusions 14 is sufficiently ensured, and interference of the second protrusions 14 with the power supply components 23 can be prevented.

[0043] The width (length in the front-to-rear direction) of the outer groove 12 is, for example, 2.0 mm to 10.0 mm, or 3.0 mm to 8.0 mm, and is constant over the entire length of the outer groove 12. If the width of the outer groove 12 is within this range, the clamping portion 41 can be smoothly fitted into the outer groove 12, and the mounting fixture 40 can stably hold the translucent cover 10.

[0044] Since the outer groove 12 is formed closer to the rear surface 10b than the back surface of the base 21, not only the outer groove 12 but also the fixture 40 that fits into the outer groove 12 does not affect the light emitted from the LED element 22. A part of the fixture 40 may extend toward the front surface of the base 21, but it is preferable that the fixture 40 be located outside the range in which the light emission angle θ of the LED element 22 is 60° in the cross section of the light source 1 in the width direction. In this case, the light emitted from the LED element 22 is not substantially affected by the fixture 40. In this embodiment, the entire fixture 40 is located closer to the rear surface 10b than the front surface of the base 21.

[0045] The configuration of the fixture 40 will be described in further detail below with reference to Figures 4 and 5. Figure 5 is a perspective view of the fixture 40.

[0046] As shown in FIGS. 4 and 5 , the mounting fixture 40 has a pair of clamping portions 41, a fixing portion 42, and an inclined portion 46 formed between each of the clamping portions 41 and the fixing portion 42. The mounting fixture 40 is a metal fitting formed by bending a single metal plate, and the pair of clamping portions 41 extend in the same direction facing each other, forming a generally U-shaped overall configuration. The fixing portion 42 and the inclined portion 46 are longer in the longitudinal direction than in the width direction of the translucent cover 10. The inclined portion 46 is a portion that is inclined outward from both sides of the fixing portion 42 in the width direction so as to gradually move away from the mounting surface 50. As will be described in detail later, the inclined portion 46 forms a space between the mounting fixture 40 and the rear surface portion 10b of the translucent cover 10 through which wiring can be passed.

[0047] The mounting fixture 40 has a fixing portion 42 fixed to the mounting surface 50 using a screw 51, and the clamping portion 41 fitted into the outer groove 12 of the light-transmitting cover 10, thereby fixing the light source 1 to the mounting surface 50. An insertion hole 43 for the screw 51 is formed in the fixing portion 42, and, for example, one mounting fixture 40 is fixed to the mounting surface 50 using one screw 51. The fixing portion 42 is formed flat so as to abut against the flat mounting surface 50 without any gaps, but, for example, if the mounting surface 50 is curved, the fixing portion 42 may be curved to fit along the mounting surface 50. The insertion hole 43 is formed in the center of the fixing portion 42 in the longitudinal and width directions.

[0048] As described above, the clamping portion 41 is positioned outside the range where the light emission angle θ of the LED elements 22 is 60° in the widthwise cross section of the light source 1, and holds the translucent cover 10 on the back surface side of the base 21. Assuming a Lambertian light distribution, 60° corresponds to a 1 / 2 light distribution angle. By positioning the fixture 40 outside this angle range, light can be extracted efficiently from the light source 1. In this embodiment, the fixture 40 is not present on the front surface side of the base 21, and the fixture 40 does not block the light emitted from the LED elements 22. Only the front surface portion 10a of the translucent cover 10 is disposed in front of the LED elements 22.

[0049] The clamping portion 41 has a protrusion 44 formed by bending a metal plate at a right angle or an acute angle. The protrusion 44 has an L-shape in cross section and protrudes toward the light-transmitting cover 10. By forming the protrusion 44 on the clamping portion 41, the clamping portion 41 fits securely into the outer groove 12, thereby stably holding the light-transmitting cover 10. Substantially only the protrusion 44 of the clamping portion 41 abuts against the side surface portion 10c of the light-transmitting cover 10, and the portion where the protrusion 44 is formed clamps the light-transmitting cover 10. The pair of clamping portions 41 have substantially the same length, and each has a protrusion 44 at its tip at a position facing each other in the width direction.

[0050] The protrusion 44 includes a tip 44a, a first region 44b, and a second region 44c. The pair of clamping portions 41 have portions extending from the boundaries with the respective inclined portions 46 substantially perpendicular to the fixed portion 42. The tip portions away from the inclined portions 46 are formed with the first region 44b, which bends toward each other, and the second region 44c, which is folded back at the tip 44a and bends away from each other. The angle between the first region 44b and the second region 44c is, for example, 90°±10° or 90°±5°. The tip 44a is also formed with a region extending substantially perpendicular to the fixed portion 42.

[0051] The portion of the clamping portion 41 that contacts the light-transmitting cover 10 is formed linearly along the longitudinal direction of the cover. In the example shown in FIG. 4, the tip portion 44a and the second region 44c contact the side surface portion 10c of the light-transmitting cover 10, but if the front surface portion 10a faces vertically downward, for example, the tip portion 44a and the first region 44b contact the side surface portion 10c. The tip portion 44a, the first region 44b, and the second region 44c are formed linearly without any irregularities along the longitudinal direction. In this case, damage to the light-transmitting cover 10 can be prevented when the mounting fixture 40 moves relative to the light-transmitting cover 10.

[0052] The clamping portion 41 holds the light-transmitting cover 10 with an elastic force that allows the light source 1 to slide in the longitudinal direction of the light-transmitting cover 10, but prevents the light source 1 from sliding under its own weight. That is, with the clamping portion 41 fitted in the outer groove 12, the user can slide the light-transmitting cover 10 in the longitudinal direction, but even if the light source 1 is positioned so that the longitudinal direction of the light-transmitting cover 10 is oriented vertically, the light source 1 is firmly held by the clamping portion 41 and will not fall. In this case, the position of the light source 1 can be finely adjusted after it has been attached to the fixture 40 while the light source 1 is stably held.

[0053] The clamping portion 41 preferably has an elastic resin coating 45 on the inner surface that contacts the light-transmitting cover 10. The resin coating 45 increases the frictional force against the outer surface of the light-transmitting cover 10, and particularly suppresses relative movement between the light source 1 and the fixture 40 along the longitudinal direction of the light-transmitting cover 10. By providing the resin coating 45, the fixture 40 can stably hold the light source 1 even when the light source 1 is positioned so that the longitudinal direction of the light-transmitting cover 10 is aligned vertically. The resin coating 45 also contributes to suppressing damage to the light-transmitting cover 10.

[0054] The material constituting the resin coating 45 is not particularly limited, but a suitable example is silicone resin. The resin coating 45 is formed, for example, by coating the inner surface of the clamping portion 41 with paint containing silicone resin or the like. The resin coating 45 may be formed only on the protrusions 44 of the clamping portion 41, but from the viewpoints of improving productivity and suppressing unintended movement of the light source 1, the resin coating 45 is formed on the entire inner surface of the mounting fixture 40. The thickness of the resin coating 45 is, for example, 0.1 mm or more and 1.0 mm or less.

[0055] When the clamping portion 41 is fitted into the outer groove 12, the fixing portion 42 is disposed between the fixing portion 42 and the light-transmitting cover 10 with a space therebetween for passing a wire. In this embodiment, the inclined portion 46 forms a portion including the fixing portion 42 and the inclined portion 46 convex rearward, ensuring a space between the fixing portion 42 and the light-transmitting cover 10 for passing the power line 35 even when the screw 51 is attached to the insertion hole 43. The fixing portion 42 is disposed substantially parallel to the side surface portion 10c of the light-transmitting cover 10 with a gap between it and the rear surface portion 10b. The gap between the rear surface portion 10b and the fixing portion 42 is, for example, 5.0 mm or more and 15.0 mm or less, and the power line 35 can be passed through this gap when the screw 51 is attached to the insertion hole 43 of the fixing portion 42. In this case, the contact area with the mounting surface 50 is also reduced, thereby suppressing damage to the mounting surface 50.

[0056] An example of a mounting form of the light source 1 will be described below with reference to Fig. 6. Fig. 6 is a cross-sectional view of the light source 1 fixed to a mounting surface 50, taken along the longitudinal direction.

[0057] In the example shown in FIG. 6, the light source 1 is fixed to the mounting surface 50 using two mounting fixtures 40 that are screwed to the mounting surface 50. One mounting fixture 40 is provided between the longitudinal center and both ends of the light source 1. In the example shown in FIG. 6, a mounting fixture 40X is attached to the longitudinal center of the light source 1. Like the mounting fixture 40, the mounting fixture 40X is attached to the outer groove 12 of the light-transmitting cover 10, but differs from the mounting fixture 40 in that it is not screwed to the mounting surface 50. In other words, the mounting fixture 40X does not fix the light source 1 to the mounting surface 50.

[0058] The mounting fixture 40X is used to route the power line 35 drawn out from the mounting surface 50 along the longitudinal direction of the light-transmitting cover 10. The mounting fixture 40X routes the power line 35 from the insertion hole 43X of the fixing portion 42X between the fixing portion 42X and the rear surface portion 10b, and routes the power line 35 so that it extends along the longitudinal direction of the light source 1. The power line 35 further passes between the mounting fixture 40, which is screwed to the mounting surface 50, and the rear surface portion 10b, and is introduced into the light-transmitting cover 10 through the insertion hole 31 of the side cover 30. As described above, the fixing portion 42 is arranged with a space between it and the rear surface portion 10b to allow the power line 35 to pass through, even when the screw 51 is fixed in the insertion hole 43.

[0059] The mounting fixture 40X can be the same as the mounting fixture 40, or a dedicated mounting fixture can be used. An example of a dedicated mounting fixture is a fixture having an insertion hole 43X with a larger diameter than the insertion hole 43 of the mounting fixture 40. In this case, it becomes easier to pass the wire through the insertion hole 43X. Furthermore, the mounting fixture 40 may have a wire insertion hole in addition to the insertion hole 43 for the screw 51.

[0060] As described above, the light source 1 having the above configuration can be mass-produced at low cost with a small number of parts, and can efficiently emit light over a wide range, including both longitudinal ends of the light source 1. Furthermore, the fixture 40 can be easily attached to the translucent cover 10 without impairing the performance and appearance of the light source 1, and can fix the light source 1 to the intended mounting surface. The light source 1 is suitable as a replacement for a straight tube fluorescent lamp, and can also be used as a standalone lighting fixture by directly attaching the light source 1 to a ceiling, wall, etc. using the fixture 40.

[0061] The light source 1's translucent cover 10 has a cylindrical wall formed integrally with the front portion 10a, rear portion 10b, and pair of side portions 10c by extrusion molding of translucent resin, and can be manufactured in any length. This allows products of different lengths to be manufactured easily and at low cost, and eliminates the need for assembly of multiple parts. Furthermore, LED elements 22 are mounted on the surface of the substrate 20, extending to both ends of the substrate 20 at longitudinal intervals of 10 mm to 80 mm. In this case, light can be efficiently emitted along substantially the entire length of the light source 1, and heat generation from the substrate 20 is sufficiently suppressed, eliminating the need for a heat sink.

[0062] In addition, the second convex portion 14 that forms part of the inner groove 11 effectively prevents light from leaking around to the back surface of the base 21. As a result, the boundary between light and dark appears clearly at the position of the inner groove 11 on the side surface 10c of the translucent cover 10, achieving a neat appearance. Furthermore, light can be extracted efficiently from the light source 1.

[0063] The fixture 40 can be easily attached to the light source 1 by utilizing the outer groove 12 of the light-transmitting cover 10. Furthermore, by forming an elastic resin coating 45 on the inner surface of the clamping portion 41, damage to the light-transmitting cover 10 is suppressed, and the light source 1 can be stably held even when the light source 1 is positioned so that the longitudinal direction of the light-transmitting cover 10 is aligned vertically. Furthermore, the fixture 40 is attached to the cover with a space for passing the power line 35 between the fixing portion 42 and the rear surface portion 10b of the light-transmitting cover 10 secured, so the power line 35 can be smoothly routed using the fixture 40.

[0064] The above embodiment can be modified as appropriate within the scope of the purpose of the present disclosure. For example, in the above embodiment, the second convex portion 14 is formed by the outer groove 12 being recessed into the inside of the translucent cover 10. However, it is also possible to form a convex portion having the function of the above-mentioned shielding portion independently of the outer groove 12. Similar to the second convex portion 14, the convex portion covers the back surface of the substrate at both ends in the width direction of the substrate to prevent light leakage to the back surface side. However, from the viewpoint of miniaturization and cost reduction of the translucent cover, when the outer groove 12 is formed, it is preferable to form the convex portion using the outer groove 12.

[0065] In the above embodiment, the inner groove 11, which is a holding groove for the substrate 20, is formed over the entire longitudinal length of the light-transmitting cover 10, but it is also possible to use a light-transmitting cover that does not have a holding groove. In this case, the holding portion for the substrate may be formed on the lid that closes the opening of the light-transmitting cover. However, from the viewpoints of productivity of the light source, stability of the substrate, etc., it is preferable to form the inner groove 11 in the light-transmitting cover so that the substrate 20 can be inserted.

[0066] The present disclosure is further illustrated by the following embodiments. Configuration 1: A light source comprising a rigid housing formed in a long cylindrical shape, and a long, flat substrate having an LED element mounted on its surface and inserted into the internal space of the housing, with a power supply component mounted on the back surface of the substrate for supplying power to the LED element, the housing having a cylindrical wall integrally molded from a translucent resin and configured so that the substrate can be inserted from an axial end. Configuration 2: The light source according to configuration 1, wherein the LED elements are mounted at intervals of 10 mm to 80 mm in the longitudinal direction of the substrate, and no heat sink is provided for radiating heat. Configuration 3: The light source according to configuration 1, wherein the LED elements are mounted at intervals of 30 mm to 80 mm in the longitudinal direction of the substrate, and no heat sink is provided for radiating heat. Configuration 4: The light source according to any one of configurations 1 to 3, wherein the inner surface of the housing has a holding groove for the substrate, the holding groove being formed over the entire axial length and into which both widthwise ends of the substrate are inserted. Configuration 5: The light source according to configuration 3, wherein an outer groove into which a mounting fixture fits is formed over the entire axial length on the outer surface of the housing on the rear side of the board. Configuration 6: The light source according to Configuration 5, wherein the outer groove forms a convex portion that protrudes into the internal space of the housing, and the convex portion constitutes part of the holding groove and also functions as a shielding portion that covers both widthwise ends of the back surface of the substrate to prevent light from leaking to the back surface side. Configuration 7: A light source according to any one of configurations 1 to 5, wherein the housing has a protrusion formed thereon over the entire axial length thereof that protrudes into the internal space, and the protrusion functions as a shield at both widthwise ends of the substrate to cover the rear surface of the substrate and prevent light from leaking to the rear surface side. Configuration 8: The light source according to any one of configurations 1 to 7, further comprising a lid attached to an axial end of the housing, the lid having an insertion hole for a power line for supplying AC power to the power supply component. [Explanation of symbols]

[0067] 1 light source 10. Translucent cover 10a Front part 10b Rear part 10c Side part 11 Inner groove 12 Outer groove 13 First convex part 14 Second convex part 15 Locking hole 20 Substrate 21 Base 22 LED elements 23 Power Supply Components 30 Side cover 31 Insertion hole 35 Power line 40 Mounting fixture 41 Clamping part 42 Fixed part 43 Insertion hole 44 Convex part 44a Tip 44b 1st area 44c 1st area 45 Resin coating 46 Slope 50 Mounting surface 51 Bis

Claims

1. a rigid housing formed in a long cylindrical shape; a long, flat substrate having an LED element mounted on its surface and inserted into the internal space of the housing; Equipped with A power supply component that supplies power to the LED element is mounted on the back surface of the substrate, The housing has a cylindrical wall integrally molded from a light-transmitting resin, and is configured so that the substrate can be inserted from an axial end thereof.

2. 10. The light source of claim 1, The LED elements are mounted in plurality at intervals of 10 mm or more and 80 mm or less in the longitudinal direction of the substrate, It does not have a heat sink to radiate heat.

3. 10. The light source of claim 1, The LED elements are mounted in plurality at intervals of 30 mm or more and 80 mm or less in the longitudinal direction of the substrate, It does not have a heat sink to radiate heat.

4. 10. The light source of claim 1, The inner surface of the housing is formed with holding grooves for the board, the holding grooves being adapted to receive both widthwise ends of the board, and extending over the entire axial length.

5. 5. The light source of claim 4, An outer groove into which a mounting fixture fits is formed over the entire axial length on the outer surface of the housing on the rear side of the board.

6. 6. The light source of claim 5, the outer groove forms a protrusion that protrudes into the internal space of the housing, The convex portion constitutes a part of the holding groove, and also functions as a shielding portion that covers both widthwise ends of the rear surface of the substrate to prevent light from leaking to the rear surface side.

7. 10. The light source of claim 1, The housing has a protrusion formed thereon over the entire axial length thereof, the protrusion protruding into the internal space. The convex portions function as shielding portions that cover the rear surface of the substrate at both widthwise ends of the substrate and prevent light from leaking to the rear surface side.

8. The light source according to any one of claims 1 to 7, Further, a cover attached to an axial end of the housing is provided, The cover has an insertion hole for a power line that supplies AC power to the power supply component.

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