Lighting device

Abstract

This invention provides a lighting device that can be easily miniaturized as a whole, and that can efficiently utilize light by focusing the light from the light source in one direction to increase light intensity. [Solution] The lighting device 10 installed along the ceiling 3 of a passenger compartment 2 of a railway vehicle 1 comprises: a light source 20 that emits light toward the ceiling 3 from one longitudinal side; a lens 30 that distributes the light emitted from one side of the light source 20 by spreading it out to both sides of the side from an optical axis perpendicular to the side; and a reflecting part 40 that receives and reflects the light distributed to the other side in a direction that overlaps with the light distributed to one side of the side of the light source 20 by the lens 30.

Description

Technical Field

[0001] The present invention relates to a lighting device installed along a wall surface, which reflects light on the wall surface to indirectly illuminate the surroundings. For example, it is installed on the ceiling in the passenger compartment of a railway vehicle and used for indirect lighting.

Background Art

[0002] Conventionally, as interior lights used in the passenger compartments of railway vehicles, airplanes, automobiles, etc., for example, various lighting devices attached to the ceiling in the passenger compartment are known. Here, as typical interior lights, in addition to direct lighting that directly illuminates the passenger compartment with light from the ceiling, many indirect lighting methods that irradiate direct light upward to the ceiling and reflect it to illuminate the passenger compartment with the reflected indirect light have been proposed.

[0003] For example, Patent Document 1 describes a lighting device that includes a casing attached to the ceiling side and opening inward downward, and an LED substrate is assembled as a light source inside the casing. The direct light from the LED passes through a protective cover (lens) and is reflected inside the casing, and the passenger compartment is indirectly illuminated by this reflected indirect light.

[0004] In the lighting device described in Patent Document 1, due to the use of LEDs with a narrow irradiation range as light sources, in order to widen the irradiation range as much as possible, two LED substrates are assembled in opposite directions. Here, each LED substrate is assembled in a so-called vertical arrangement, which is inclined at an angle close to the vertical direction perpendicular to the ceiling in order to widen the irradiation range with respect to the horizontal ceiling.

[0005] In such a lighting device described in Patent Document 1, since two LED substrates are used even in one light source unit, there is a problem that the number of parts and the assembly man-hours increase. Moreover, since the LED substrates are vertically arranged and the protective cover is also vertically arranged accordingly, the height outer shape greatly protrudes in the vertical direction with respect to the ceiling by the width of each, and there is also a problem that it does not conform to the outer shape constraints in vehicles with a low ceiling.

[0006] Therefore, as a technology that can solve such problems, for example, Patent Document 2 describes a lighting device equipped with a lens that can spread light distribution to both sides of the passenger compartment without using reflection by the casing, by arranging only one LED substrate horizontally parallel to the ceiling. In the lighting device described in Patent Document 2, the overall height and dimensions of the device were large and bulky because the power supply board, which is separate from the light source, is mounted vertically, but the space required for arranging the light source and lens could be reduced in size. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 5600657 [Patent Document 2] Japanese Patent Publication No. 2024-139559 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In the lighting device described in Patent Document 1 mentioned above, the light from the two LED substrates was not controlled by lenses, but was directly received by the reflective surface inside the casing and reflected towards the ceiling. As a result, not only was it necessary to orient the LED substrates vertically, but a larger reflective surface was also required inside the casing, which led to an overall increase in the size of the lighting device.

[0009] Furthermore, in the lighting device described in Patent Document 2, if the light source unit consists of only one LED substrate and lens, it is possible to reduce the space required for its placement. However, if, of the two-sided light distribution of each light source unit, only one of the two-sided light distribution directions is sufficient, then not only will the light distribution to the other direction be wasted, but there is also a risk that the light intensity of the light distribution to the one direction will not be sufficient.

[0010] This invention addresses the problems of the conventional technology described above, and aims to provide a lighting device that can be easily miniaturized as a whole, and that can efficiently concentrate light from a light source in one direction to increase light intensity and make effective use of it. [Means for solving the problem]

[0011] To achieve the aforementioned objectives, one aspect of the present invention is: In a lighting device that is installed along a wall and indirectly illuminates the surroundings by reflecting light off the wall, A light source that is narrow in width and extends in the longitudinal direction, and emits light toward the wall surface from one side along the longitudinal direction, A lens is positioned along the longitudinal direction of the light source so as to cover one side thereof, and the light emitted from one side is spread out in directions to both sides of that side from the optical axis perpendicular to that side, The device is characterized by comprising a reflecting part that receives and reflects light distributed to the other side of the light source in a direction that overlaps with the light distributed to one side, from among the light distributed to both sides of one side of the light source by the lens. [Effects of the Invention]

[0012] According to the present invention, the entire lighting device can be easily miniaturized, and the light from the light source can be efficiently concentrated in one direction to increase light intensity and be used effectively. [Brief explanation of the drawing]

[0013] [Figure 1] This is an end view showing the lighting device according to this embodiment. [Figure 2] This is an end view showing the case of the lighting device according to this embodiment. [Figure 3] This is an end view showing the light source and lens of the lighting device according to this embodiment. [Figure 4] This is a perspective view showing the lighting device according to this embodiment. [Figure 5] This is a perspective view of the lighting device according to this embodiment, taken from a different angle. [Figure 6] It is an explanatory diagram showing the light distribution control of the lighting device according to this embodiment. [Figure 7] It is a longitudinal sectional view showing the interior of a railway vehicle compartment including the ceiling where the lighting device according to this embodiment is installed.

Mode for Carrying Out the Invention

[0014] Hereinafter, representative embodiments of the present invention will be described based on the drawings. Figs. 1 to 7 show an embodiment of the present invention. The lighting device 10 according to this embodiment is a device that is installed along a wall surface and reflects light on the wall surface to indirectly illuminate the surroundings. Hereinafter, a case where the lighting device 10 is applied to, for example, the "ceiling light" in the ceiling of a railway vehicle compartment will be described as an example.

[0015] Note that the components, shapes, numerical values, etc. shown in this embodiment are all examples of the present invention and do not limit the present invention. Also, in each figure, the slight differences in shape of the same part are merely design changes. Of course, the relative dimensional relationships, shapes, etc. of the components shown in each figure may be appropriately changed in design and may be different from the actual product.

[0016] <Overview of Lighting Device 10> As shown in Fig. 7, the lighting device 10 is installed along the wall surface of the ceiling 3 in the compartment 2 of the railway vehicle 1. The lighting device 10 extends in the longitudinal direction that is the front - rear direction of the railway vehicle 1, and is installed such that a pair is arranged parallel to each other with the center line S in both side directions of the ceiling 3 that is orthogonal to this longitudinal direction in between. Here, the pair of lighting devices 10 irradiate light toward both the central side and the end side of the ceiling 3 in both side directions. Note that a luggage rack 4 is supported from the side wall below the end side of the ceiling 3.

[0017] The lighting device 10 uses the ceiling 3 (equivalent to the "wall surface") as a reflector as it is, and functions as indirect lighting that illuminates the interior of the room indirectly with light from the ceiling 3. In FIG. 7, the pair of lighting devices 10 arranged in both side directions of the ceiling 3 are symmetric with respect to the center line S of the ceiling 3 on both sides, but are installed with the same configuration and different orientations. Note that the lighting devices 10 are combined and installed so that they are arranged in a row in the longitudinal direction according to the necessary length with respect to the total length of the ceiling 3 and the like.

[0018] As shown in FIG. 1, the lighting device 10 includes a case 11 that forms the outer shape of the entire device, a light source 20 and a lens 30 attached to the case 11, and a reflecting portion 40 provided as a part of the case 11. In the present embodiment, two sets of each of the light source 20, the lens 30, and the reflecting portion 40 unit are provided for one case 11. Of course, the number of units such as the light source 20 in one case 11 is not limited to two sets, and may be only one set or three sets or more.

[0019] <Regarding the case 11> As shown in FIG. 1, the case 11 is a container (lamp body) that forms the outer shape of the lighting device 10, and is formed in a long shape extending in the longitudinal direction so as to attach the light source 20 and the lens 30 over the entire length. As shown in FIGS. 2, 4, and 5, the case 11 includes a base portion 12 supported by the ceiling 3 and a cover portion 13 on the bottom side that covers the base portion 12 from below.

[0020] <<Base portion 12 (reflecting portion 40)>> The base portion 12 is a portion supported by the ceiling 3 for installing the entire lighting device 10 along the ceiling 3. The light source 20 and the lens 30 are attached, and the reflecting portion 40 is integrally provided. The base portion 12 is formed so as to cover the upper surface side opening of the cover portion 13 and is disposed inside the peripheral edge of the cover portion 13. Further, the light source 20 and the lens 30 are attached to the base portion 12 at positions overlapping the inside of the cover portion 13 in plan view, respectively.

[0021] In case 11 of this embodiment, two sets of light sources 20 and lenses 30 are attached to one base portion 12, and one reflector 40 is also provided for each set. That is, a first mounting surface portion 121 is provided on one end of the base portion 12 in the direction of both sides (towards the center of the ceiling 3) to which a set of first light sources 20 and first lenses 30 is attached. A first reflector 40A is integrally provided next to the first mounting surface portion 121.

[0022] The first mounting surface 121 is the part on which the light source 20 and the lens 30 are mounted in a superimposed state. The first mounting surface 121 has a width that matches the dimensions of both sides of the lens 30 and is formed as a flat surface that extends longitudinally along the entire length of the base 12. Both ends of the first mounting surface 121 rise up in a flange-like manner, and recessed groove rail-shaped engaging portions 121a are provided inside them for fitting and engaging both ends of the lens 30 from above. The first reflecting portion 40A is provided so as to rise above one of the engaging portions 121a on one side of the engaging portions 121a at both ends of the first mounting surface 121.

[0023] On the other hand, a second mounting surface 122 is provided on the other end of the base portion 12 (the end of the ceiling 3) to which the second light source 20 and the second lens 30, which form another set, are attached. A second reflector 40B is integrally provided next to the second mounting surface 122. Here, the second light source 20 has the same configuration as the first light source 20, and the second lens 30 also has the same configuration as the first lens 30. Although the configurations of the first reflector 40A and the second reflector 40B are slightly different, when referring to them collectively without distinction, they are simply written as reflector 40.

[0024] The second mounting surface 122, like the first mounting surface 121, is the part on which the light source 20 and the lens 30 are mounted in an overlapping state, and is formed in a planar shape extending in the longitudinal direction. Both ends of the second mounting surface 122 also rise up in a flange-like manner, and engaging portions 122a are provided on the inside of these flanges for fitting and engaging both ends of the lens 30 from above. The second reflective portion 40B is provided so as to rise above one of the engaging portions 122a on both ends of the second mounting surface 122.

[0025] Furthermore, the base portion 12 is provided with mounting surface portions 123 in the central part on both sides for installation on the ceiling 3. The mounting surface portion 123 is a planar portion that extends longitudinally along the entire length of the base portion 12 between the first mounting surface portion 121 and the second mounting surface portion 122, and forms the "reference surface" for the installation of the entire lighting device 10. The mounting surface portion 123 is set to be located on the horizontal plane when the lighting device 10 is installed on the ceiling 3. Related components such as the power supply unit 50 are arranged in the empty space above and below the mounting surface portion 123.

[0026] As shown in Figure 2, a first mounting surface 121 is provided along one end of the mounting surface 123 (the central side of the ceiling 3), and a second mounting surface 122 is provided along the other end of the mounting surface 123 (the edge side of the ceiling 3). In the vertical direction perpendicular to the reference plane of the mounting surface 123, the first mounting surface 121 is provided at a lower position than the mounting surface 123, and the second mounting surface 122 is provided at a higher position than the mounting surface 123.

[0027] More specifically, the middle portion of the back side of the first reflective portion 40A is connected along one end of the mounting surface portion 123, and the other end of the first mounting surface portion 121 is connected along the lower end of the first reflective portion 40A. In other words, the first mounting surface portion 121 is connected to one end of the mounting surface portion 123 via the first reflective portion 40A. Furthermore, as described above, the first reflective portion 40A is provided to rise from above the engaging portion 121a on the other end (one side) of the first mounting surface portion 121.

[0028] Here, the first mounting surface portion 121 is positioned to intersect the reference plane of the mounting surface portion 123 at an acute angle and obliquely. The first reflecting portion 40A is shaped to receive light from the light source 20 and lens 30 attached to the first mounting surface portion 121 toward the other end (the end of the ceiling 3), as described later, and reflect it in a direction that overlaps with the light distributed toward one end (the center of the ceiling 3). In particular, the reflective surface of the first reflecting portion 40A is provided with a concave curved cross-sectional shape that concentrates and reflects the light distribution from the lens 30 in the width direction.

[0029] Furthermore, along the other end of the mounting surface 123, one end of the second mounting surface 122 and the lower end of the second reflective portion 40B are connected via a thicker portion that raises them. Here, as described above, the second reflective portion 40B is provided so as to rise upward from the engaging portion 122a located on one end (one side) of the second mounting surface 122.

[0030] The second mounting surface 122 is basically symmetrical and has almost the same shape as the first mounting surface 121 described above, but the configuration below the bottom surface of the second mounting surface 122 is different as shown in the figure. The second mounting surface 122 is provided in the opposite direction to the first mounting surface 121 so as to intersect the reference surface of the mounting surface 123 at an acute angle and diagonally. In addition, the second reflector 40B is slightly different from the first reflector 40A.

[0031] The second reflector 40B is shaped to receive light from the light source 20 and lens 30 mounted on the second mounting surface 122, with the light distribution directed to one end (the center side of the ceiling 3) in the opposite direction to that of the first reflector 40A, and to reflect the light in a direction that overlaps with the light distributed to the other end (the edge side of the ceiling 3). The reflective surface of the second reflector 40B is also shaped with a concave cross-section that focuses and reflects the light distribution from the lens 30 in the width direction, but the second reflector 40B is smaller in vertical width and more compact than the first reflector 40A.

[0032] Such a base portion 12 can be constructed by extrusion molding from a metal such as aluminum, including all the aforementioned parts such as the first mounting surface portion 121, the second mounting surface portion 122, the installation surface portion 123, the first reflecting portion 40A, and the second reflecting portion 40B, to have a uniform cross-sectional shape along its entire length. If the base portion 12 is made of a metal with high thermal conductivity such as aluminum, it will function as a heat sink to dissipate the heat emitted by the light source 20, etc.

[0033] Furthermore, as shown in Figure 2, the portion of the second mounting surface 122, which is the other end of the base portion 12, below the bottom surface, serves as a bearing portion 125 and is rotatably connected to the other end of the cover portion 13, which will be described next, via a hinge 14. Therefore, the cover portion 13 can be opened and closed from one end 131 relative to the base portion 12, with the hinge 14 on the other end as the pivot point. Specifically, the hinge 14 should be, for example, a torque hinge (spring hinge) that biases the cover portion 13 in the direction of closing relative to the base portion 12. Note that, as shown in Figure 4, the hinges 14 are not continuous in the longitudinal direction of the base portion 12, etc., but rather multiple hinges are arranged at predetermined intervals.

[0034] <<Cover section 13>> As shown in Figure 1, the cover portion 13 is formed as an exterior surface facing the interior of the passenger compartment. The inside of the cover portion 13 is designed as a space that can receive the molten lens 30, which will be described later, when it drips down. More specifically, the cover portion 13 has both ends along its longitudinal direction that curve gently upward, and overall, it has a curved cross-sectional shape that is inclined relative to the base portion 12, with one end 131 (towards the center of the ceiling) being higher than the other end 132 (towards the edge of the ceiling).

[0035] The inside of such a cover portion 13 becomes a space that can receive the lens 30 when it is molten and dripped, if the lens 30 described later is made of a resin material. The cover portion 13, like the base portion 12, is preferably formed by extrusion molding from a metal such as aluminum to have a uniform cross-sectional shape over its entire length, including the receiving portion 133 and the bearing portion 134 described below. If the cover portion 13 is made of a metal with high thermal conductivity such as aluminum, it will also serve as a heat sink to dissipate the heat emitted by the light source 20, etc.

[0036] Furthermore, a receiving portion 133 is integrally provided on the inner surface of the cover portion 13, near one end, protruding from the inner surface and extending longitudinally parallel to the one end 131. The receiving portion 133 is the part that contacts the receiving portion 124 provided along the lower part of the other end of the first mounting surface portion 121 of the base portion 12. Here, the receiving portion 124 and the receiving portion 133 are preferably configured to actively contact each other not only by the biasing force of the hinge 14, but also by, for example, a magnet 124a and an iron plate 133a.

[0037] On the other hand, a bearing portion 134 is integrally provided on the inner surface of the cover portion 13, near the other end, and is erected higher than the receiving portion 133 on the inner surface and extends longitudinally parallel to the other end. The bearing portion 134 is the part of the base portion 12 that faces the bearing portion 125, and the bearing portion 125 and the bearing portion 134 are rotatably connected by a hinge 14. Here, the entire cover portion 13 with the bearing portion 134 is biased to align with the base portion 12 by the biasing force of the hinge 14 itself.

[0038] <Regarding light source 20> As shown in Figure 2, the light source 20 is formed in a narrow shape extending in the longitudinal direction, and emits light perpendicular to that surface from one side along its entire length (longitudinal direction). Specifically, the light source 20 is constructed, for example, by mounting multiple surface-mount type chip LEDs 22 as light-emitting elements at predetermined intervals (e.g., 10 mm) on one side of a narrow substrate 21 extending in a straight line. Such a light source 20 is formed in a bar shape overall and is also called a bar light.

[0039] In the light source 20, multiple chip LEDs 22 are arranged in a single row along the center line of one side of the substrate 21, with their optical axes positioned perpendicular to that side. With such a light source 20, light is emitted from one side of the substrate 21 along its entire length in a nearly continuous direction perpendicular to the substrate 21 and in the longitudinal direction. However, the illumination range of the light source 20 in both directions perpendicular to the longitudinal direction is limited to a relatively narrow angle centered on the optical axis of the chip LEDs 22, and the emitted light does not spread widely in both directions from both ends of the substrate 21.

[0040] The configuration of the chip LED 22 itself is fairly standard, so a detailed explanation will be omitted. However, the light-emitting color of the chip LED 22 can be arbitrarily selected, and multiple colors can be combined as appropriate, not just a single color. Furthermore, the chip LED 22 may be a full-color LED capable of emitting any color by mixing the three primary colors. Note that the light-emitting element of the light source 20 is not limited to the chip LED 22; an LED lamp in which the chip is embedded in a dome-shaped mold may also be used.

[0041] The substrate 21 is a narrow, straight-line plate, and on one of its surfaces, the mounting surface, are multiple chip LEDs 22 arranged in a row, as well as a connector 23 that connects to the power supply unit 50, which will be described later. The connector 23 does not extend along the entire length of the substrate 21, but is provided in pairs at both ends in the longitudinal direction of the substrate 21, with the chip LEDs 22 at those locations in between. In addition, although not shown, wiring patterns for the electrical connections of the chip LEDs 22 and connector 23 are printed on the mounting surface of the substrate 21. Specifically, the substrate 21 is formed into a narrow plate shape from a relatively rigid material such as a glass epoxy substrate.

[0042] The substrate 21 forms the main part of the outer shape of the light source 20. It is narrow and extends in the longitudinal direction, but its width in the transverse direction perpendicular to the longitudinal direction is also predetermined to the required size. In other words, the substrate 21 is designed to have a predetermined width because it not only mounts the chip LEDs 22 on its mounting surface, but also provides the connector 23 and necessary wiring patterns. This width of the substrate 21, i.e., the width of the light source 20, is a factor that determines the overall height of the lighting device 10 when it is installed along a wall, as it protrudes vertically from the wall.

[0043] The light source 20 is mounted such that the other side of the substrate 21 opposite to the mounting surface is in contact with the first mounting surface 121 (second mounting surface 122) of the base portion 12 in the case 11. In the basic installation state of the entire lighting device 10 on the ceiling 3, the substrate 21 of the light source 20 is held in a position tilted at an angle to the horizontal plane. The light source 20 is held in a predetermined position within the case 11 by fitting both ends along the longitudinal direction of the substrate 21 into the engagement portions 121a (122a) on both sides of the first mounting surface 121 (second mounting surface 122) described above. Note that the total length of the light source 20 (substrate 21) does not necessarily have to match the total length of the case 11; for example, multiple lenses 30 of a predetermined length are arranged in a row in one case 11.

[0044] <About Lens 30> As shown in Figure 3, the lens 30 allows light emitted from the light source 20 to pass through and distributes the light. It is positioned along the longitudinal direction of the light source 20, covering one side of it (the mounting surface of the substrate 21). The lens 30 is formed in an elongated shape that extends in the longitudinal direction and has a predetermined, uniform cross-sectional shape overall.

[0045] Specifically, the lens 30 is integrally molded from a transparent resin material such as acrylic or polycarbonate, which is a light-transmitting material. The total length of the lens 30 does not necessarily have to match the total length of the light source 20; for example, multiple lenses 30 may be arranged in a line around a continuous light source 20.

[0046] The lens 30 distributes the light emitted from one side of the light source 20 along its longitudinal direction, spreading it not only in the optical axis direction perpendicular to that side but also to both sides of that side. As mentioned above, from one side of the light source 20, light is emitted in a nearly continuous direction from each chip LED 22 arranged in a row on the mounting surface of the substrate 21. The lens 30 is designed to receive light from one side of the light source 20 in a cross-section perpendicular to its longitudinal direction and distribute it not only in the optical axis direction perpendicular to that side but also to both sides of the substrate 21.

[0047] More specifically, as shown in Figure 3, the lens 30 comprises a bottom surface 31 facing one side of the light source 20, an incident surface 32 with a semicircular cross-section recessed along the center line L (in both directions) extending in the longitudinal direction of the bottom surface 31, into which light from the chip LED 22 enters, and an exit surface 33 forming the outer perimeter on the opposite side of the bottom surface 31 that emits light to the outside. In addition, side ends 34, 34 protruding in both directions are provided at both ends of the lens 30 that form the boundary between the bottom surface 31 and the exit surface 33.

[0048] The lens 30 is mounted so that its bottom surface 31 overlaps the light source 20 with the first mounting surface 121 (second mounting surface 122) of the case 11, and its two end surfaces 34 engage with the engaging portions 121a (122a) on both sides of the first mounting surface 121 (second mounting surface 122). In this way, the lens 30 is mounted to the case 11 in a state that covers the light source 20. Furthermore, the bottom surface 21 of the lens 30 is provided with a recess 35 in which the connector 23 of the light source 20 is accommodated, as the connector 23 protrudes onto the mounting surface of the substrate 21. Here, the recess 35 is formed to be continuous along the longitudinal direction of the lens 30.

[0049] As shown in Figure 3, the emission surface 33 of the lens 30 has a concave curved surface portion 33a with a shallow depression in the center of its outer circumference along its longitudinal direction, and convex curved surfaces 33b, 33b that form peaks on both sides of the concave curved surface portion 33a. The center line L of the lens 30, i.e., the center of the concave curved surface portion 33a, is located on the optical axis of the chip LED 22. Therefore, the concave curved surface portion 33a functions as a concave lens that spreads the light from the emission surface 33 in the width direction of the lens 30, and the convex curved surface portion 33b functions as a convex lens that focuses the light from the emission surface 33 in the width direction. Note that the concave curved surface portion 33a and the convex curved surfaces 33b on both sides are continuous without being separated by a physical boundary. The specific details of the light distribution by such a lens 30 will be described later.

[0050] <Regarding the power supply unit 50> As shown in Figures 1 and 3, the power supply unit 50 for supplying power to the light source 20 is positioned on the upper surface of the base portion 12 of the case 11, between one end and the other end in a direction perpendicular to its longitudinal direction, specifically on the mounting surface 123 between the first mounting surface 121 and the second mounting surface 122. In this way, a large space for positioning the power supply unit 50 can be secured between the first mounting surface 121 and the second mounting surface 122 on the upper surface of the base portion 12.

[0051] The power supply unit 50 is configured as a unit on a power supply board 51, equipped with an AC / DC converter, capacitors, resistors, and connectors 52 that are connected to the connectors 23 of the light sources 20 via wiring, and is enclosed by a box-shaped housing 53 that forms its outer shape. The bottom surface of the housing 53 is fixed to the mounting surface 123 by screws or the like. The power supply unit 50 is common to all light sources 20, and one power supply unit 50 supplies power to multiple light sources 20, each connected via the connectors 23.

[0052] In this way, the empty space in the base section 12 can be effectively utilized for the placement of the power supply unit 50. Therefore, there is no need to perform any special cutouts or modifications on the ceiling 3 to accommodate the power supply unit 50, and the installation work of the lighting device 10 on the ceiling 3 can be simplified. In addition, a connector 54 for connecting to the commercial power supply is provided on the lower side of the installation surface section 123 located below the housing 53.

[0053] The upper surface of the housing 53 is set to form a horizontal plane parallel to the mounting surface 123, which forms the "reference surface" of the entire lighting device 10. Therefore, when installing the lighting device 10 on the ceiling 3, the housing 53 may also be configured to serve as a mounting bracket in addition to the end cap described below. Furthermore, as shown in Figure 1, although the second mounting surface 122 on the other end is higher than the mounting surface 123, the outer height of the housing 53 is set to the same height as the uppermost position of the reflecting section 40B, which extends even further upward than the second mounting surface 122. This reduces the overall height (thickness) of the lighting device 10.

[0054] Furthermore, if the housing 53 is constructed from a material with excellent thermal conductivity, such as aluminum, similar to the case 11, it will serve as a heat sink to dissipate the heat generated by the chip LEDs 22 of the light source 20. Although not shown, the housing 53 may also house a control unit that controls the lighting drive of the light source 20, or the control unit may be incorporated into the power supply unit 50. The lighting device 10 also includes an end cap that attaches to the end of the case 11, although this is not shown. The end cap is a component that fits over the end of the case 11 and also serves as a mounting bracket for installing the lighting device 10 on the ceiling 3.

[0055] <Regarding the operation of lighting device 10> The operation of the lighting device 10 according to this embodiment will be described below. <<Manufacturing of lighting device 10>> First, in manufacturing the lighting device 10, the case 11 that forms the outer shape is extruded from metal to form a uniform cross-sectional shape along its entire length, including all the small parts, with the base part 12 and the cover part 13 being molded separately. By dividing the case 11 in this way into the base part 12 to which related parts are attached and the cover part 13 that covers it from below, each part can be easily molded, reducing manufacturing costs and increasing the freedom of design and overall device design.

[0056] This makes it possible to integrally mold not only the mounting surfaces 121 and 122 for the light source 20 and other components in the case 11, but also the reflector 40, as part of the case 11 from the beginning. Therefore, the reflector 40 does not need to be attached to the case 11 as a separate component, reducing the number of parts and assembly time. Furthermore, if the entire case 11 is made of a metal with high thermal conductivity, such as aluminum, it also serves as a heat sink to dissipate the heat emitted by the light source 20 and other components.

[0057] When attaching the light source 20 and lens 30 to the base portion 12 of the case 11, the light source 20 and lens 30 are attached to the first mounting surface portion 121 and the second mounting surface portion 122, which form two units on both sides of the base portion 12. To explain using the first mounting surface portion 121 as an example, the first mounting surface portion 121 is formed such that the part on which the substrate 21 of the light source 20 is placed is recessed by the thickness of the substrate 21. The substrate 21 of the light source 20 is fitted into this recess 121b (recess 122b in the case of the second mounting surface portion 122), and the lens 30 is pressed down from above.

[0058] Since the first mounting surface 121 has engaging portions 121a on both sides for engaging with both sides of the lens 30, the lens 30 can be easily and securely attached by snap-fit ​​engagement when pressed down from above. At this time, both sides of the substrate 21 of the light source 20 are pressed down by the side ends 34 of the lens 30 that are in contact with the first mounting surface 121, so the light source 20 is also held in a stable state on the first mounting surface 121. This significantly improves the efficiency of the mounting work for the light source 20 and the lens 30.

[0059] Furthermore, it is preferable to interpose an axial elastic member (not shown) that extends along the entire length of the base portion 12 between the engaging portion 121a on one side (right side in Figure 1) of the first mounting surface portion 121 of the base portion 12 and the side end portion 34 of the lens. Such an elastic member will press the side end portion 34 of the lens 30 toward the other side (left side in Figure 1), thereby reliably supporting the lens 30 in a stable state on the first mounting surface portion 121 without any wobbling in the width direction.

[0060] The same applies to the mounting of the light source 20 and lens 30 on the second mounting surface 122. Also, on the upper side of the base portion 12, the power supply board 51 and housing 53 of the power supply unit 50 are attached to the mounting surface 123 between the first mounting surface 121 and the second mounting surface 122, and the connector 54 is attached to the lower side of the mounting surface 123. The assembled base portion 12 is then rotatably connected to the bearing portion 125 on the other end via a hinge 14 to the bearing portion 134 on the other end of the cover portion 13.

[0061] In this way, by making the cover portion 13 openable and closable relative to the base portion 12, maintenance and inspection of related components such as the connector 54 located in the internal space between them becomes easier. Furthermore, the cover portion 13 has a space inside that can receive the lens 30 when it melts and drips, which will be described in more detail later.

[0062] <<Installation of lighting device 10>> As shown in Figure 1, the completed lighting device 10 is installed, for example, on the ceiling 3 of a passenger compartment 2 in a railway car 1 and used as an interior light. In this case, as shown in Figure 7, the lighting device 10 is installed symmetrically on both sides with respect to the center line S of the ceiling 3, and functions as indirect lighting, illuminating the passenger compartment from the ceiling 3 with indirect light, roughly half and half. The lighting device 10 shown in Figure 1, which corresponds to the right-hand lighting device 10 in Figure 7, will be described below as representative.

[0063] To install the lighting device 10 on the ceiling 3 in the passenger room 2, it is fixed by screws or the like via an end cap (not shown in the illustration). At this time, the upper surface of the housing 53 faces the ceiling 3 in a horizontal position, and the installation surface 12, which forms the "reference surface" for the installation of the entire lighting device 10, is also maintained at the horizontal angle initially assumed.

[0064] <Light distribution of lighting device 10> As shown in Figure 6, when the lighting device 10 is installed on the ceiling 3, light is emitted from one end unit (left side in Figure 6) toward the center of the ceiling 3, and from the other end unit (right side in Figure 6) toward the edge of the ceiling 3. In this case, the substrate 21 of the light source 20 of each unit is tilted slightly with respect to the horizontal plane toward the side from which the light is emitted, and the optical axis of the chip LED 22 on the substrate 21 is also tilted toward the side from which the light is emitted with respect to the vertical direction, but the main light distribution control is performed by the lens 30 and the reflector 40.

[0065] In other words, in the light source 20, the light emitted from the chip LEDs 22 arranged in a row on the substrate 21 is controlled in its distribution as it enters the incident surface 32 of the lens 30 located on its optical axis and reaches the exit surface 33. As shown in Figure 3, the lens 30 according to this embodiment has a concave curved surface portion 33a that is shallowly recessed in the center of the exit surface 33, and convex curved surfaces 33b, 33b that form peaks on both sides of this concave curved surface portion 33a, so that it irradiates light in a wide span direction as shown by hatching in Figure 6.

[0066] This light distribution control of the lens 30 allows the light to be distributed not only along the optical axis perpendicular to one surface of the substrate 21, but also to both sides of that surface. Furthermore, regarding the placement of the substrate 21 on the light source 20, it is no longer necessary to use a nearly vertical orientation as in conventional technology; a tilt close to the horizontal plane is sufficient. As a result, the width of the light source 20 and lens 30 does not protrude vertically from the ceiling 3, and the thickness of the case 11, and consequently the overall height of the device, can be kept as low as possible.

[0067] Furthermore, for each unit, of the light distributed in both directions by the lens 30, the light directed to one side (thick hatched line in Figure 6) is directed directly towards the ceiling 3, while the light directed to the other side is received by the reflector 40 and reflected in a direction that overlaps with the light directed to the other side (thin hatched line in Figure 6). Below, the first reflector 40A will be described as a representative example of the first reflector 40A and second reflector 40B in the two sets of units shown in Figure 6.

[0068] As shown in Figure 6, in the unit at one end (left side in Figure 6), of the light distributed by the lens 30 in both directions, the light directed toward one side of the ceiling 3, which is the central side (thick hatched line in Figure 6), is directed toward the central side of the ceiling 3, with the one end 131 of the cover portion 13 as the lower limit. On the other hand, the light distributed by the lens 30 toward the other end of the ceiling 3, which is opposite to the central side of the ceiling 3, is reflected by the reflecting portion 40A located immediately next to it in a direction that overlaps with the light directed toward the central side of the ceiling 3 (one side) (thin hatched line in Figure 6).

[0069] Thus, even when using a lens 30 that distributes light in both directions, if light distribution to only one side (the center side of the ceiling 3) is sufficient, combining it with a reflector 40A allows for improved light intensity on one side without wasting light distributed to the other side (the edge side of the ceiling 3). In other words, by utilizing the characteristics of the lens 30 that distributes light in both directions, it becomes possible to concentrate and effectively utilize the light distributed to one side, along with the light distributed to the other side, through reflection by the reflector 40. Moreover, even from the limited opening in case 11, it becomes possible to further widen the vertical width of the illumination range in one direction. That is, the direct illumination light from the lens 30 in one direction is distributed upward toward the ceiling 3, while the reflected light from the reflector 40 is distributed downward toward the ceiling 3, overlapping with the direct illumination light in one direction.

[0070] Here, the reflecting part 40A only needs to be able to reflect the light distribution from the lens 30 to the other side in the opposite direction to one side. Therefore, the reflecting part 40A can be formed to be just large enough to cover the area from the end 34 of the lens 30 to the emission surface 33 slightly above this end 34. Consequently, there is no need to secure a large space for the reflecting part 40A next to the lens 30, and the case 11 as a whole can be miniaturized to the minimum necessary external dimensions.

[0071] By miniaturizing the reflective section 40A and the space required for its placement, and in conjunction with the aforementioned ingenious arrangement of the light source 20, lens 30, and power supply unit 50 housing 53, the overall external height of the lighting device 10 can be kept even lower. Therefore, this lighting device 10 can be installed in railway vehicles 1, such as express trains with low ceilings 3 and a lowered center of gravity to improve stability when traveling on curves at high speeds, without significantly encroaching on the passenger compartment 2.

[0072] Furthermore, by having a concave cross-sectional shape that focuses and reflects the light distribution from the lens 30 in the width direction, effective lateral light distribution is possible without obstruction, even through the narrow opening between the upper edge of the reflector 40A and one side end 131 of the cover 13. However, the reflector 40A is not necessarily limited to a concave cross-sectional shape; for example, it can be flat as long as it can reflect the light illuminating in the aforementioned one direction. In addition, the lens 30 eliminates the need for a protective cover (lens) as in conventional technology, which reduces the weight equivalent to the material and enhances safety, including during product assembly.

[0073] Furthermore, the light distribution control by the light source 20, lens 30, and second reflector 40B in the other end unit of the lighting device 10 (right side in Figure 6) is almost identical to that of the one end unit (left side in Figure 6) described above, except for the left-right orientation being reversed, but differs in the following respect. That is, the second reflector 40B is smaller in vertical width and more compact than the first reflector 40A. This is because the light distribution to the end side of the ceiling 3 hits the side wall immediately, so a smaller illuminance is sufficient compared to the light distribution to the center side of the ceiling 3. Also, it is preferable to focus the reflected light from the second reflector 40B towards the luggage rack 4 on the side wall (see Figure 7).

[0074] <Measures to prevent molten dripping from lighting device 10> In this lighting device 10, assuming installation in the passenger compartment 2 of a railway vehicle 1, measures have been taken to prevent the molten synthetic resin from dripping, allowing synthetic resin to be used as the material for the lens 30. Specifically, the inside of the cover portion 13 of the case 11 is made into a space that can receive the molten lens 30 if it drips down. Therefore, even if the lens 30 is made of synthetic resin and melts, the molten material can fall and accumulate inside the cover portion 13, and there is no risk of the molten material dripping into the passenger compartment 2.

[0075] In particular, as shown in Figure 1, the base portion 12 is positioned inward from the periphery of the cover portion 13, and the light source 20 and lens 30 are mounted on the base portion 12 in positions that overlap the inside of the cover portion 13 in a plan view. This makes it possible to more reliably catch molten material from the lens 30 or broken fragments of the light source 20 without them falling into the passenger cabin 2.

[0076] As a result, the lens 30 can be made of a material that is easy to process, durable, and inexpensive, and can be used as a material for railway vehicles, as in this embodiment. In addition, it is possible to reduce the weight compared to when glass is used as the material for the lens 30, and the lens 30 will not break like glass, thus improving safety.

[0077] Furthermore, since the cover portion 13 can be opened and closed relative to the base portion 12 by a hinge 14, maintenance and inspection of related parts located in the internal space enclosed by the base portion 12 and the cover portion 13 are made easier, and post-processing in the event that the lens 30 melts and drips onto the inside of the cover portion 13 is also made easier. The cover portion 13 is normally held stably in a closed state not only by the biasing force of the hinge 14 but also by the attractive force of the magnet 124a (magnetic catch).

[0078] <Construction and Effects of the Invention> Although this embodiment has been described above, the present invention is not limited to the embodiments described above. The present invention derived from the embodiments described above will be described below.

[0079] First, the present invention relates to a lighting device 10 that is installed along a wall surface 3 and indirectly illuminates the surroundings by reflecting light off the wall surface 3, A light source 20 that is narrow in the longitudinal direction and emits light toward the wall surface 3 from one side along the longitudinal direction, A lens 30 is positioned along the longitudinal direction of the light source 20 so as to cover one side thereof, and the light emitted from one side is spread out in directions to both sides of that side from the optical axis perpendicular to that side, The device is characterized by comprising a reflecting section 40 that receives and reflects light distributed to the other side of the light source 20 in a direction that overlaps with the light distributed to one side, from among the light distributed to both sides of one side by the lens 30.

[0080] With this configuration of the lighting device 10, the light emitted from one side of the light source 20 is spread by the lens 30 to both sides of the optical axis of the light source 20. However, the light directed to one side is directed directly towards the wall 3, while the light directed to the other side is received by the reflector 40 and reflected in a direction that overlaps with the light directed to the one side.

[0081] Therefore, assuming a lens 30 that distributes light in both directions, for example, if light distribution in only one direction is sufficient, combining it with the reflecting section 40 allows for improved light intensity of the light distributed to one side without wasting the light distributed to the other side. In other words, by taking advantage of the characteristics of the lens 30 that distributes light in both directions, it becomes possible to concentrate and effectively utilize the light distributed to one side, as well as the light distributed to the other side, through reflection by the reflecting section 40.

[0082] Here, the reflecting part 40 only needs to reflect the light distribution from the lens 30 to one side that is in the opposite direction, so it can be made as small as possible. Note that the "one side" of the light source 20 is the mounting surface of the substrate 21, and the "optical axis" of the light source 20 is the optical axis of the chip LED 22.

[0083] Furthermore, the present invention includes a longitudinally extending case 11 on which the light source 20 and the lens 30 are each mounted along their entire length. The reflective portion 40 is characterized in that it is provided as part of the case 11.

[0084] This configuration allows the light source 20 and lens 30 to be mounted together in the case 11, which forms the overall shape of the device. In particular, since the reflective section 40 is provided as part of the case 11 from the beginning, there is no need to add it to the case 11 separately, which reduces the number of parts and assembly time. However, the reflective section 40 is not limited to being integrally molded as part of the case 11; it is also conceivable to mold it separately from the case 11 and add it to the case 11 later.

[0085] Furthermore, in the present invention, the case 11 is provided in a shape that has a space inside it that can receive the lens 30 when it melts and drops into place. With this configuration, even if the lens 30, which is made of synthetic resin, were to melt, the molten material could be contained inside the case 11, and there would be no risk of the molten material dripping into the passenger compartment. Therefore, the lens 30 can be made of a material that is easy to process, durable, and inexpensive, such as synthetic resin, which can withstand melting and dripping.

[0086] Furthermore, in the present invention, the case 11 comprises a cover portion 13 that is on the bottom side and includes the space, and a base portion 12 that covers the upper opening of the cover portion 13. The base portion 12 is positioned inward from the periphery of the cover portion 13. The light source 20 and the lens 30 are mounted on the base portion 12 in positions that overlap the inside of the cover portion 13 in a plan view.

[0087] By dividing the case 11 into a base section 12 for attaching related components and a cover section 13 that covers it from below, it becomes easier to design each section with its own unique design. Furthermore, molten material from the lens 30 and broken fragments of the light source 20 can be more reliably caught without falling into the passenger compartment 2.

[0088] Furthermore, in the present invention, the light source 20, the lens 30, and the reflecting part 40 are arranged in two sets: a first light source 20, a first lens 30, and a first reflecting part 40A, and a second light source 20, a second lens 30, and a second reflecting part 40B, which form the other set. Of the base portion 12, a first light source 20 and a first lens 30 are attached along one end in a direction perpendicular to the longitudinal direction, emitting light toward the center of the ceiling 3 of the guest room 2, which is the wall surface 3, while a second light source 20 and a second lens 30 are attached to the other end, emitting light toward the edge of the ceiling 3. Of the base portion 12, a first reflecting portion 40A is provided along the side of the first lens 30, in a direction that overlaps with the light distributed to the central side of the ceiling 3 by the first lens 30, and receives and reflects the light distributed to the other side. The base portion 12 is characterized in that a second reflecting portion 40B is provided along the side of the second lens 30, in a direction that overlaps with the light distributed to one side, the end of the ceiling 3, by the second lens 30, and receives and reflects the light distributed to the other side.

[0089] With this configuration of lighting device 10, the two sets of units on both sides of the base section 12 make it possible to illuminate the ceiling 3 of the passenger room 2 separately, towards both the center and the edges.

[0090] Furthermore, in the present invention, the other end of the cover portion 13 is rotatably connected to the other end of the base portion 12, The cover portion 13 is characterized in that it can be opened and closed relative to the base portion 12, with the other end as the pivot point.

[0091] In this way, by configuring the cover portion 13 to be openable and closable relative to the base portion 12, maintenance and inspection of related components located in the internal space enclosed by the base portion 12 and the cover portion 13 becomes easier. Furthermore, as mentioned above, post-processing in the event that the lens 30 melts and drips onto the inside of the cover portion 13 also becomes easier.

[0092] Furthermore, the present invention is characterized in that a power supply unit 50 for supplying power to the light source 20 is arranged between one end and the other end of the base portion 12 in a direction perpendicular to the longitudinal direction.

[0093] This configuration allows the available space in the base section 12 to be effectively utilized for the placement of the power supply unit 50. Consequently, there is no need to perform any special cutouts or modifications on the wall surface 3 on which the lighting device 10 is installed to accommodate the power supply unit 50, and the installation work of the lighting device 10 on the wall surface 3 can be simplified.

[0094] While embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to the embodiments described above, and any changes or additions that do not depart from the spirit of the present invention are also included. For example, although an example of installing the lighting device 10 on the ceiling 3 inside the passenger compartment of a railway vehicle has been described, it may also be applied to indirect lighting inside passenger compartments of other vehicles such as aircraft and automobiles, or to indirect lighting in indoor facilities or general households. Furthermore, the wall surface on which the lighting device 10 is installed is not necessarily limited to the ceiling, but may also be a side wall or floor surface, etc.

[0095] Furthermore, although the lighting device 10 is configured to emit light towards both the center of the ceiling 3 and the end of the ceiling 3 above the luggage rack 4 using two sets of units on both sides, it may also be configured to have only one set of units to emit light towards only one side of the ceiling 3 in the bilateral direction. In addition, the ceiling 3 may also be provided with a main lighting device, for example, along the center line S in the bilateral direction, although this is not shown in the illustration, separate from the pair of lighting devices 10.

[0096] Furthermore, the specific shape of case 10 is not limited to the illustrated example. Also, the shape of the emission surface 33 of lens 30 is not particularly limited; any shape that yields a light distribution where the intensity of light spreading in the width direction of the lens is higher than the intensity of light in the vertical direction does not need to have a concave curved surface 33a. In addition, the specific shapes of each reflecting part 40A, 40B are not limited to the illustrated example. [Industrial applicability]

[0097] The lighting device according to the present invention can be widely used not only for indirect lighting in passenger compartments of railway cars, aircraft, automobiles, etc., but also for general-purpose lighting installed on various wall surfaces. [Explanation of Symbols]

[0098] 1…Railway vehicles 2…Guest rooms 3… Ceiling 4… Luggage racks 10…Lighting devices 11… Case 12...Base section 121...First mounting surface 122...Second mounting surface 13...Cover part 20…Light source 21… Circuit board 22…Chip LED 30... Lens 31...Bottom 32...Incidence plane 33… Launch surface 40A...First reflector 40B...Second reflector 50...Power supply section 53… Housing

Claims

1. In a lighting device that is installed along a wall and indirectly illuminates the surroundings by reflecting light off the wall, A light source that is narrow in width and extends in the longitudinal direction, and emits light toward the wall surface from one side along the longitudinal direction, A lens is positioned along the longitudinal direction of the light source so as to cover one side thereof, and the light emitted from one side is spread out in directions to both sides of that side from the optical axis perpendicular to that side, A lighting device characterized by comprising: a reflecting part that receives and reflects light distributed to the other side in a direction that overlaps with the light distributed to one side, from among the light distributed to both sides on one side of the light source by the lens.

2. The light source and the lens are each mounted in a longitudinally extending case that extends along its entire length. The lighting device according to claim 1, characterized in that the reflective portion is provided as part of the case.

3. The lighting device according to claim 2, characterized in that the case is provided in a shape that has a space inside it that can receive the lens when it melts and drips down.

4. The case comprises a cover portion that is on the bottom side and includes the space, and a base portion that covers the opening on the upper side of the cover portion. The base portion is positioned inward from the periphery of the cover portion. The lighting device according to claim 3, characterized in that the light source and the lens are mounted on the base portion in positions that overlap the inside of the cover portion in a plan view.

5. The light source, the lens, and the reflecting part consist of two sets: one set comprising a first light source, a first lens, and a first reflecting part, and the other set comprising a second light source, a second lens, and a second reflecting part. Of the base portion, a first light source and a first lens are attached along one end in a direction perpendicular to the longitudinal direction, emitting light toward the center of the ceiling of the guest room which is the wall surface, while a second light source and a second lens are attached to the other end, emitting light toward the edge of the ceiling. In the base portion, a first reflecting portion is provided along the side of the first lens, which receives and reflects light distributed to the other side in a direction that overlaps with the light distributed by the first lens to the central side of the ceiling, which is one of the two sides. The lighting device according to claim 4, characterized in that the base portion is provided with a second reflecting portion along the side of the second lens, which receives and reflects light distributed to the other side in a direction that overlaps with the light distributed to one side, the edge of the ceiling, by the second lens.

6. The other end of the cover portion is rotatably connected to the other end of the base portion. The lighting device according to claim 5, characterized in that the cover portion is made openable and closable relative to the base portion, with the other end as the pivot point.

7. The lighting device according to claim 6, characterized in that a power supply unit for supplying power to the light source is arranged between one end and the other end of the base portion in a direction perpendicular to the longitudinal direction.

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