Lighting apparatus

Abstract

To provide a lighting apparatus that is useful when installed such that a tube axis extends along a tunnel axis direction, and that can increase illuminance over a wide range in the tunnel axis direction.SOLUTION: A lighting apparatus is a straight-tube lighting apparatus that is installed on an installation surface of a culvert and irradiates light toward a side opposite to the installation surface, the lighting apparatus including an LED substrate in which multiple LED elements are arranged along a tube axis direction, a cylindrical protective body that accommodates the LED substrate, and a reflector that intersects the tube axis direction and has a reflective surface that reflects light from the multiple LED elements in the tube axis direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a lighting device, and more particularly to a lighting device that uses an LED (Light Emitting Diode) as a light source. [Background technology]

[0002] In recent years, efforts have been made to use LEDs as light sources in lighting devices that are installed in poor temperature environments such as urban areas and underground tunnels in urban areas in order to achieve energy savings and longer lifespans (see, for example, Patent Document 1). Generally, when installing lighting devices in tunnels, the installation intervals and other factors are set with reference to the optical characteristics of the lighting devices.

[0003] The optical characteristics of a straight-tube lighting device with a tube axis (lamp axis) are expressed by the light distribution characteristics in the AA plane perpendicular to the tube axis (hereinafter referred to as the "AA light distribution characteristics"), the light distribution characteristics in the BB plane including the tube axis (hereinafter referred to as the "BB light distribution characteristics"), and the light distribution characteristics in the CC plane tilted at 45 degrees to the AA and BB planes (hereinafter referred to as the "CC light distribution characteristics") (see Figure 1). In a lighting device equipped with an LED light source, the direction in which the LED elements are arranged is the tube axis.

[0004] Patent Document 1 discloses an illumination device that can suppress the decrease in luminous intensity due to deviation from the optical axis on the AA plane and improve the AA light distribution characteristics. The illumination device disclosed in Patent Document 1 can reduce the difference in brightness in the tunnel axis direction and increase illuminance over a wide range by installing the illumination device so that the tube axis is perpendicular to the tunnel axis direction, i.e., along the tunnel width direction (see Figure 2A). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7194782 Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, depending on the cross-sectional shape of the tunnel, it may be difficult to install a lighting device so that the tube axis is aligned along the tunnel width. For example, if the tunnel has a dome-shaped cross-section, it is difficult to ensure the tunnel width in the ceiling, which significantly limits the length of the lighting device's tube axis.

[0007] In this case, a lighting device with a long tube axis can be used by installing the lighting device so that the tube axis is aligned with the tunnel axis direction. However, the conventional lighting device disclosed in Patent Document 1 and the like has poor BB light distribution characteristics, and brightness differences tend to occur in the tunnel axis direction (see Figure 2B).

[0008] An object of the present invention is to provide a lighting device that is useful when installed so that the tube axis is aligned with the axial direction of the tunnel, and that can increase illuminance over a wide range in the axial direction of the tunnel. [Means for solving the problem]

[0009] The lighting device according to the present invention comprises: A straight tube lighting device that is installed on the installation surface of a culvert and irradiates light to the opposite side of the installation surface, an LED substrate on which a plurality of LED elements are arranged along the tube axis direction; A cylindrical protective body that accommodates the LED substrate; and a reflector having a reflecting surface that intersects the tube axis direction and reflects light from the plurality of LED elements in the tube axis direction. [Effects of the Invention]

[0010] According to the present invention, when the lighting device is installed so that the tube axis is aligned along the axial direction of the tunnel, the illuminance can be increased over a wide range in the axial direction of the tunnel. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of the light distribution characteristic of a straight-tube lighting device. [Figure 2]2A and 2B are diagrams showing the relationship between the installation state of the lighting device in the tunnel and the illumination range. [Figure 3] 3A and 3B are diagrams showing the appearance of the lighting device according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing the internal structure of the lighting device according to the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing the internal structure of the lighting device according to the first embodiment. [Figure 6] FIG. 6 is a diagram showing an example of an arrangement of LED elements in a light source unit. [Figure 7] FIG. 7 is a diagram showing the illumination state of the LED element when an intermediate reflector is provided. [Figure 8] FIG. 8 is a cross-sectional view showing the internal structure of the lighting device according to the second embodiment. [Figure 9] FIG. 9 is a diagram showing the illumination state of the LED element when an end reflector is provided. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0013] [First embodiment] 3A and 3B are diagrams showing the appearance of the lighting device 1 according to the first embodiment. FIG. 3A is a front view of the lighting device 1, showing the state where it is attached to an installation surface C. FIG. 3B is a plan view of the lighting device 1 as seen from the installation surface C side. FIGS. 4 and 5 are cross-sectional views showing the internal structure of the lighting device 1. FIG. 4 schematically shows a cross section perpendicular to the tube axis of the lighting device 1, and FIG. 5 schematically shows a vertical section parallel to the tube axis of the lighting device 1.

[0014] The lighting device 1 is installed, for example, on an installation surface C of a culvert such as a tunnel or passageway, and irradiates light on the side opposite the installation surface C. The lighting device 1 is installed, for example, on the ceiling of a tunnel extending horizontally, and irradiates light vertically downward on the side opposite the installation surface C. The lighting device 1 is, for example, a waterproof lighting device, and complies with JIS C 0920 IPX7.

[0015] The lighting device 1 includes a light source unit LU, a power supply unit PU, a protective body 30, etc. The light source unit LU and the power supply unit PU are housed inside the protective body 30. The LED boards 10A, 10B of the light source unit LU are electrically connected to a power supply circuit board 21 of the power supply unit PU, and power is supplied from the power supply unit PU to the light source unit LU. The power supply unit PU is also connected to a power cable 41 inside the protective body 30, and power is supplied from an external power source via the power cable 41.

[0016] The protector 30 includes a protective tube 31 , and holding cases 32 and 33 and sealing caps 34 and 35 disposed on both ends of the protective tube 31 .

[0017] The protective tube 31 is, for example, a translucent cylindrical member made of a light-transmitting material such as glass or resin. The protective tube 31 can be made of, for example, polycarbonate resin. Both ends of the protective tube 31 are closed by holding cases 32 and 33 and sealing caps 34 and 35. The protective tube 31 transmits a portion of the light emitted from the first LED elements 13A and 13B and the second LED elements 15A and 15B and reflects the remainder.

[0018] The holding cases 32 and 33 are cylindrical and made of a resin material such as ABS resin. Similarly, the sealing caps 34 and 35 are bowl-shaped and made of a resin material such as ABS resin. The holding cases 32 and 33 and the sealing caps 34 and 35 are preferably made of a thermally conductive material.

[0019] The retaining cases 32 and 33 are fitted onto both ends of the protective tube 31, for example, and are fixed to the protective tube 31 by tightening the fastening rings 36 and 37 from the axial center side. Sealing members (not shown) such as O-rings are arranged between the retaining cases 32 and 33 and the fastening rings 36 and 37 to ensure watertightness.

[0020] Hanging arms 32a, 33a are provided to protrude outward from parts of the outer periphery of the holding cases 32, 33. The hanging arms 32a, 33a are fastened to fixing pieces 51a of the flat chassis 51 with fastening members (reference numeral omitted), such as screws. When the chassis 51 is fixed to the installation surface C of the ceiling of the tunnel, the lighting device 1 is held in a suspended state from the ceiling via the hanging arms 32a, 33a.

[0021] The sealing caps 34, 35 are fastened to, for example, the holding cases 32, 33. Sealing members (not shown) such as O-rings are arranged between the sealing caps 34, 35 and the holding cases 32, 33 to ensure watertightness. One of the sealing caps 34 is provided with a cable insertion portion 42 through which a power cable 41 is pulled. The power cable 41 is pulled into the protective tube 31 through the cable insertion portion 42 and connected to the power supply unit PU.

[0022] Heat dissipation plates 38, 39 are fitted into the holding cases 32, 33. Specifically, the heat dissipation plates 38, 39 are fastened by screws to mounting pieces 32c, 33c that are integral with the holding cases 32, 33, so that heat is dissipated from the power supply circuit board 21 via the heat dissipation plates 38, 39 and the holding cases 32, 33. The heat dissipation plates 38, 39 are disk-shaped and made of a thermally conductive material such as anodized aluminum. The shape of the heat dissipation plates 38, 39 is not limited to disk, and they may have any shape, such as rectangular or elliptical, as long as they can be fastened to the mounting pieces 32c, 33c.

[0023] The power supply unit PU has a power supply circuit board 21 and a power supply module 22 mounted on the power supply circuit board 21. The power supply circuit board 21 is electrically connected to a power cable 41 and the LED boards 10A, 10B. The power supply module 22 may be any device capable of supplying power to the first LED elements 13A, 13B and second LED elements 15A, 15B mounted on the LED boards 10A, 10B, and may be configured, for example, by a DC power supply circuit.

[0024] The power supply unit PU is held in a predetermined position by joining the power supply circuit board 21 to the heat dissipation plates 38, 39. The power supply unit PU is held in a position where, for example, the power supply circuit board 21 and the chassis 51 are parallel to each other. In other words, when the lighting device 1 is installed on an installation surface C, the power supply circuit board 21 is parallel to the installation surface C. The power supply circuit board 21 and the heat dissipation plates 38, 39 are joined via a thermally conductive joining means or joining member, such as welding or fastening with screws.

[0025] The light source unit LU has two LED boards 10A and 10B. The LED boards 10A and 10B are printed wiring boards. The LED board 10A has power lines to the first LED element 13A and the second LED element 15A, etc. The LED board 10B has power lines to the first LED element 13B and the second LED element 15B, etc.

[0026] The LED substrates 10A, 10B are elongated substrates with a substantially L-shaped cross section, and are divided by a bent portion into first LED mounting substrate portions 11A, 11B and second LED mounting substrate portions 12A, 12B. The angles formed between the first LED mounting substrate portions 11A, 11B and the second LED mounting substrate portions 12A, 12B are obtuse angles. The LED substrates 10A, 10B are arranged to extend along the tube axis direction of the lighting device 1.

[0027] A plurality of first LED elements 13A, 13B are linearly arranged on the first LED mounting substrate portions 11A, 11B, respectively. The arrangement direction of the first LED elements 13A, 13B coincides with the tube axis direction of the lighting device 1. The first LED elements 13A, 13B may be arranged in a single row, or may be arranged two-dimensionally in multiple rows.

[0028] On each of the first LED mounting substrates 11A and 11B, the optical axes of the first LED elements 13A and 13B mounted thereon are the same and typically perpendicular to the LED mounting surface. When the lighting device 1 is installed on the ceiling of a culvert, the optical axes of the first LED elements 13A and 13B are directed vertically downward.

[0029] The first LED mounting substrate units 11A and 11B are fixed to the power supply circuit board 21 via spacers 23. The LED substrates 10A and 10B are held in a position where the first LED mounting substrate units 11A and 11B are parallel to the power supply circuit board 21. That is, in this embodiment, the power supply circuit board 21 functions as a support that supports the light source unit LU with respect to the protector 30.

[0030] A plurality of second LED elements 15A, 15B are linearly arranged on the second LED mounting substrate portions 12A, 12B, respectively. The arrangement direction of the second LED elements 15A, 15B coincides with the tube axis direction of the lighting device 1. The second LED elements 15A, 15B may be arranged in a single row, or may be arranged two-dimensionally in multiple rows.

[0031] On each of the second LED mounting substrate units 12A and 12B, the optical axes of the multiple second LED elements 15A and 15B mounted thereon are the same and are typically perpendicular to the LED mounting surfaces. The second LED mounting substrate units 12A and 12B are arranged so that their LED mounting surfaces face opposite each other in a vertical cross section along the tube axis direction of the lighting device 1, i.e., so that the second LED elements 15A and 15B mounted on the second LED mounting substrate units 12A and 12B illuminate different regions. In other words, the second LED mounting substrate units 12A and 12B are arranged so that the non-mounted surfaces of the second LED elements 15A and 15B face each other.

[0032] The second LED mounting substrate units 12A and 12B are disposed at an incline relative to the first LED mounting substrate units 11A and 11B. Specifically, the second LED mounting substrate units 12A and 12B are disposed such that their open ends on the opposite side from the power supply circuit board 21 (the first LED mounting substrate units 11A and 11B) approach each other. Since the first LED mounting substrate units 11A and 11B are fixed parallel to the power supply circuit board 21 and thus to the chassis 51, the second LED mounting substrate units 12A and 12B can be said to be disposed at an incline relative to the installation surface C. In addition, in a cross section perpendicular to the tube axis direction of the lighting device 1, the optical axes of the second LED elements 15A and 15B can be said to intersect each other. The LED substrates 10A and 10B are disposed symmetrically with respect to a vertical section along the tube axis direction of the lighting device 1, for example.

[0033] The light source unit LU is held in a suspended state on the power supply circuit board 21. A space is formed between the power supply circuit board 21 and the LED boards 10A, 10B (second LED mounting board portions 12A, 12B). This allows heat generated when the first LED elements 13A, 13B and the second LED elements 15A, 15B are driven to be dissipated efficiently.

[0034] Furthermore, the first LED elements 13A, 13B and the second LED elements 15A, 15B are preferably arranged alternately along the tube axis direction, as shown in Fig. 6. By arranging them in this manner, it is possible to suppress heat generation from the first LED elements 13A, 13B and the second LED elements 15A, 15B while maintaining the desired light distribution characteristics.

[0035] Furthermore, the light source unit LU includes a reflector 16. A reflecting surface 16a (see FIG. 7) of the reflector 16 intersects (typically, is perpendicular to) the tube axis direction and reflects light emitted from the first LED elements 13A and 13B and the second LED elements 15A and 15B.

[0036] The reflector 16 is made of a metal material such as aluminum, and has a mirror-finished surface. The mirror-finishing of the reflector 16 includes, for example, applying white paint to the surface or attaching a heat-resistant mirror seal.

[0037] The reflector 16 has, for example, a semicircular shape with a slit that can be inserted into the LED substrates 10A and 10B. The shape of the reflector 16 is not limited to a semicircular shape, and may be rectangular or elliptical as long as it can reflect the light from the first LED elements 13A and 13B and the second LED elements 15A and 15B in the tube axis direction.

[0038] If the thickness of the reflector 16 is too thick, the installation workability will be poor and the parts cost will increase. On the other hand, if the thickness of the reflector 16 is too thin, the mechanical strength will be reduced and the heat dissipation will be poor. For this reason, the thickness of the reflector 16 is preferably 1-2 mm. By setting the thickness of the reflector 16 to 1-2 mm, it is possible to ensure the installation workability, mechanical strength, and heat dissipation while suppressing the parts cost.

[0039] In the first embodiment, the reflector 16 is an intermediate reflector that is disposed at an intermediate position in the tube axis direction between the first LED elements 13A, 13B and the second LED elements 15A, 15B, and has both surfaces that function as reflective surfaces (hereinafter referred to as "intermediate reflector 16"). The intermediate reflector 16 is disposed, for example, at a position that divides the first LED elements 13A, 13B and the second LED elements 15A, 15B into two in the tube axis direction.

[0040] The intermediate reflector 16 may be positioned so as to divide the first LED elements 13A, 13B and the second LED elements 15A, 15B into multiple sections in the tube axis direction, and may be positioned biased to one side in the tube axis direction, or may be provided in multiple positions.

[0041] By providing intermediate reflector 16, the optical paths of the light from first LED elements 13A, 13B and second LED elements 15A, 15B can be adjusted (see FIG. 7). Therefore, when the light transmittance of holding cases 32, 33, sealing caps 34, 35, and heat dissipation plates 38, 39 is low, the proportion of light blocked by these components can be reduced, and the BB light distribution characteristics can be improved.

[0042] Thus, the lighting device 1 according to the first embodiment has the following characteristics: That is, the lighting device 1 is a straight-tube lighting device that is installed on an installation surface C of a culvert and irradiates light in a direction opposite to the installation surface C, and includes LED substrates 10A and 10B on which first LED elements 13A and 13B and second LED elements 15A and 15B (plurality of LED elements) are arranged along the tube axis direction, a cylindrical protector 30 that houses the LED substrates 10A and 10B, and a reflector 16 that intersects the tube axis direction and has a reflecting surface 16a that reflects light from the first LED elements 13A and 13B and second LED elements 15A and 15B.

[0043] According to the lighting device 1, even if the light transmittance of the holding cases 32, 33, sealing caps 34, 35, and heat dissipation plates 38, 39 attached to the end of the protector 30 in the tube axis direction is low, the proportion of light blocked by these members can be reduced, and the BB light distribution characteristics are significantly improved. Therefore, by installing the lighting device 1 so that the tube axis is aligned with the tunnel axis direction, the difference in brightness in the tunnel axis direction can be reduced, and the illuminance can be increased over a wide range in the tunnel axis direction.

[0044] In the lighting device 1, the intermediate reflector 16 is disposed at a midpoint in the tube axis direction between the first LED elements 13A, 13B and the second LED elements 15A, 15B (plurality of LED elements), and both surfaces function as reflecting surfaces 16a. This allows the adjustment of the optical paths of light from the LED elements located mainly at the midpoint in the tube axis direction among the first LED elements 13A, 13B and the second LED elements 15A, 15B, thereby improving the BB light distribution characteristics.

[0045] In the lighting device 1, the LED substrates 10A and 10B include first LED mounting substrate units 11A and 11B, in which first LED elements 13A and 13B (multiple LED elements) are arranged to emit light in a first direction perpendicular to the tube axis direction (for example, vertically when the lighting device 1 is installed on installation surface C on the ceiling of a culvert), and second LED mounting substrate units 12A and 12B, in which second LED elements 15A and 15B (multiple LED elements) emit light in a second direction perpendicular to the tube axis direction and different from the first direction. More specifically, the LED substrates 10A and 10B are arranged symmetrically with respect to a vertical cross section along the axial direction. Increasing the number of LED elements further improves the BB light distribution characteristics of the lighting device 1, and also improves the AA light distribution characteristics. Therefore, when the lighting device 1 is installed so that the tube axis is aligned with the tunnel axis direction, the illuminance can be increased over a wide range in the tunnel width direction.

[0046] In the lighting device 1, the first LED elements 13A, 13B (LED elements arranged on the first LED mounting substrate parts 11A, 11B) and the second LED elements 15A, 15B (LED elements arranged on the second LED mounting substrate parts 12A, 12B) are arranged alternately along the tube axis direction. This makes it possible to suppress heat generation from the first LED elements 13A, 13B and the second LED elements 15A, 15B while maintaining desired light distribution characteristics, and to prevent damage to the LED elements due to heat.

[0047] [Second embodiment] In the lighting device 1 according to the first embodiment, an intermediate reflector 16 is disposed at a midpoint in the tube axis direction between the first LED elements 13A, 13B and the second LED elements 15A, 15B. In contrast, in the lighting device 2 according to the second embodiment, reflectors 17 are disposed at end positions in the tube axis direction between the first LED elements 13A, 13B and the second LED elements 15A, 15B (hereinafter referred to as "end reflectors 17"). The configuration of the end reflectors 17 is similar to that of the intermediate reflector 16 according to the first embodiment, and therefore a description thereof will be omitted.

[0048] The lighting device 2 according to the second embodiment has the following features in addition to or instead of the features of the lighting device 1 according to the first embodiment. That is, the lighting device 2 is provided with an end reflector 17 that is arranged at an end position in the tube axis direction of the first LED elements 13A, 13B and the second LED elements 15A, 15B (plurality of LED elements) and has one surface that functions as a reflecting surface 17a (see FIGS. 8 and 9). This makes it possible to adjust the optical paths of light from the first LED elements 13A, 13B and the second LED elements 15A, 15B on the end sides that are likely to be blocked by the holding cases 32, 33, the sealing caps 34, 35, and the heat dissipation plates 38, 39 when they have low light transmittance, thereby effectively improving the BB light distribution characteristics.

[0049] When the LED substrates 10A, 10B and the heat dissipation plates 38, 39 are close to each other in the tube axis direction, the heat dissipation plates 38, 39 may function as end reflectors.

[0050] The invention made by the inventor has been specifically described above based on an embodiment, but the present invention is not limited to the above embodiment and can be modified within the scope of the gist thereof.

[0051] For example, in the embodiment, the lighting devices 1 and 2 are described as being installed on the ceiling of a tunnel, but the lighting devices 1 and 2 may also be installed on the side walls of the tunnel.Furthermore, in a tunnel that extends vertically, the lighting devices 1 and 2 may be installed at a predetermined interval in the vertical direction.

[0052] Furthermore, in the lighting devices 1 and 2, a phosphorescent material may be disposed between the two LED substrates 10A and 10B so as to protrude beyond the ends of the LED substrates 10A and 10B. This can increase the illuminance over a wide range in the tunnel axis direction, and improve visibility due to the phosphorescence of the phosphorescent material.

[0053] Furthermore, the intermediate reflector 16 of the first embodiment and the end reflector 17 of the second embodiment may be used together in one lighting device.

[0054] The present invention can also be applied to a lighting device having either one of the first LED elements 13A, 13B and the second LED elements 15A, 15B.

[0055] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0056] 1, 2 Lighting equipment 10A, 10B LED board 11A, 11B First LED mounting board section 12A, 12B Second LED mounting board section 13A, 13B First LED element 15A, 15B Second LED element 16 Reflector, intermediate reflector 17 Reflector, end reflector

Claims

1. A straight tube lighting device that is installed on the installation surface of a culvert and irradiates light to the opposite side of the installation surface, an LED substrate on which a plurality of LED elements are arranged along the tube axis direction; a cylindrical protective body that accommodates the LED substrate; a reflector having a reflective surface that intersects the tube axis direction and reflects light from the plurality of LED elements in the tube axis direction, Lighting equipment.

2. The reflector includes an intermediate reflector disposed at an intermediate position in the tube axis direction of the plurality of LED elements, and both surfaces of the intermediate reflector function as the reflecting surfaces. The lighting device according to claim 1 .

3. The reflector includes an end reflector disposed at an end position of the plurality of LED elements in the tube axis direction, one surface of which functions as the reflecting surface. The lighting device according to claim 1 .

4. The LED substrate includes a first LED mounting substrate portion in which the plurality of LED elements are arranged to irradiate light in a first direction perpendicular to the tube axis direction, and a second LED mounting substrate portion in which the plurality of LED elements irradiate light in a second direction perpendicular to the tube axis direction and different from the first direction. The lighting device according to claim 1 .

5. The LED substrates are arranged symmetrically with respect to a vertical cross section along the tube axis direction.

5. The lighting device according to claim 4.

6. The LED elements arranged on the first LED mounting substrate portion and the LED elements arranged on the second LED mounting substrate portion are arranged alternately along the tube axis direction.

5. The lighting device according to claim 4.

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