Lighting device

Abstract

The present invention provides a lighting device that can easily match the actual peak angle in the AA light distribution characteristics to the target peak angle, and can increase illuminance over a wide area in the tunnel axis direction. [Solution] The lighting device is a straight-tube type lighting device installed on the installation surface of a culvert and irradiating light on the opposite side from the installation surface, comprising: a plurality of LED elements; two LED substrates on which the plurality of LED elements are arranged along the tube axis direction and which are arranged so that the non-mounted sides of the LED elements face each other; and a translucent protective tube that houses the LED substrates, wherein the LED substrate has a first substrate portion on which the LED elements are mounted and a second substrate portion formed by bending the first substrate portion at a predetermined substrate bending angle θ1, the substrate bending angle θ1 being 50°

Description

Technical Field

[0005] ,

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

Background Art

[0002] In recent years, in lighting devices installed in a harsh temperature environment such as in urban areas and tunnels underground in urban areas, in order to achieve energy saving and long life, the light source is being made into an LED (for example, see Patent Documents 1 to 4). Generally, when installing a lighting device in a tunnel, the installation interval etc. are set referring to the optical characteristics of the lighting device.

[0003] The optical characteristics of a straight tube type lighting device having a tube axis (lamp axis) are represented by the light distribution characteristics in the A-A plane orthogonal to the tube axis (hereinafter referred to as "A-A light distribution characteristics"), the light distribution characteristics in the B-B plane including the tube axis (hereinafter referred to as "B-B light distribution characteristics"), and the light distribution characteristics in the C-C plane inclined 45° with respect to the A-A plane and the B-B plane (hereinafter referred to as "C-C light distribution characteristics") (see FIG. 1). In a lighting device provided with an LED light source, the arrangement direction of the LED elements becomes the tube axis.

[0004] FIG. 1 is a diagram showing an example of the light distribution characteristics of a straight tube type lighting device. When the lighting device shown in FIG. 1 is installed on the ceiling, the optical axis faces vertically downward. As shown in FIG. 1, generally, as the irradiation direction deviates from the vertical direction (0°), the luminous intensity decreases. Also, the A-A light distribution characteristics have a smaller decrease in luminous intensity depending on the irradiation direction compared to the B-B light distribution characteristics and the C-C light distribution characteristics, and the angular range (light distribution angle) in which a predetermined luminous intensity (for example, 50% of the luminous intensity in the optical axis direction) can be obtained is large. Therefore, when installing a plurality of lighting devices having the light distribution characteristics shown in FIG. 1 along the extending direction of the tunnel (hereinafter referred to as "tunnel axis direction"), the lighting devices are installed so that the tube axis is orthogonal to the tunnel axis direction, and the A-A light distribution characteristics with a large light distribution angle are applied to the tunnel axis direction (see FIG. 2).

[0005] Furthermore, Patent Documents 1 to 4 disclose a lighting device in which two LED substrates on which LED elements are mounted are arranged so that their respective optical axes intersect each other. In such a lighting device, the beam angle in the AA light distribution characteristics is larger compared to the case where the optical axis is pointed vertically downward. Therefore, it is useful when it is desired to efficiently secure a predetermined brightness along the tunnel axis direction. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2013-51193 [Patent Document 2] Japanese Patent Publication No. 2012-43558 [Patent Document 3] Patent No. 7179921 [Patent Document 4] Patent No. 7194782 [Overview of the project] [Problems that the invention aims to solve]

[0007] In lighting devices such as those disclosed in Patent Documents 1 to 4, it is generally assumed that the angle in the direction of the optical axis of the LED element becomes the peak angle of the AA light distribution. Therefore, the direction of the optical axis of the LED element, that is, the mounting angle of the LED substrate, is designed based on the target peak angle of the AA light distribution (hereinafter referred to as the "target peak angle").

[0008] However, even when the mounting angle of an LED substrate is designed to match a target peak angle, the actual peak angle may not match the target peak angle.

[0009] The object of the present invention is to provide a lighting device that can easily match the actual peak angle in the AA light distribution characteristics to the target peak angle, and can increase illuminance over a wide range in the tunnel axis direction. [Means for solving the problem]

[0010] The lighting device according to the present invention is A straight-tube type lighting device that is installed on the installation surface of a culvert and irradiates light on the opposite side from the installation surface, Multiple LED elements, Multiple LED elements are arranged along the tube axis direction, and two LED substrates are arranged so that the non-mounted sides of the LED elements face each other, It comprises a translucent protective tube that houses the LED substrate, The LED substrate has a first substrate portion on which the LED elements are mounted, and a second substrate portion formed by bending the first substrate portion at a predetermined substrate bending angle θ1. The substrate bending angle θ1 is set to be greater than the target peak angle θ2 for AA light distribution, taking into account the refraction of light emitted from the LED element in the protective tube. [Effects of the Invention]

[0011] According to the present invention, the actual peak angle in the AA light distribution characteristics can be easily matched to the target peak angle, and the illuminance can be increased over a wide area in the tunnel axis direction. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows an example of the light distribution characteristics of a straight-tube lighting device. [Figure 2] Figure 2 shows the relationship between the installation configuration of lighting devices inside a tunnel and the illumination range. [Figure 3] Figures 3A and 3B show the external appearance of the lighting device according to the embodiment. [Figure 4] Figure 4 is a cross-sectional view showing the internal structure of a lighting device according to an embodiment. [Figure 5] Figure 5 is a cross-sectional view showing the internal structure of a lighting device according to an embodiment. [Figure 6] Figures 6A and 6B are explanatory diagrams of the light distribution peak angle of the lighting device. [Figure 7]FIG. 7 is a diagram showing the light distribution characteristics of the lighting device. [Figure 8] FIG. 8 is a diagram showing an example of the relationship between the substrate bending angle and the light distribution peak angle. [Figure 9] FIG. 9 is a diagram showing an example of the relationship between the substrate bending angle and the minimum floor illuminance and the average illuminance.

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0014] FIGS. 3A and 3B are diagrams showing the appearance of the lighting device 1 according to the embodiment. FIG. 3A is a front view of the lighting device 1 and shows the state of being attached to the installation surface C. FIG. 3B is a plan view of the lighting device 1 viewed from the side of the installation surface C. 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. FIG. 5 schematically shows a longitudinal section parallel to the tube axis of the lighting device 1.

[0015] The lighting device 1 is installed, for example, on the installation surface C of a culvert such as a tunnel or a tunnel, and irradiates light to the side opposite to the installation surface C. The irradiation device 1 is installed, for example, on the ceiling of a tunnel extending in the horizontal direction, and irradiates light downward vertically on the side opposite to the installation surface C. The lighting device 1 is, for example, a waterproof lighting device and complies with JIS C 0920 IPX7.

[0016] The lighting device 1 includes a light source unit LU, a power supply unit PU, a protective body 30, and the like. The light source unit LU and the power supply unit PU are housed inside the protective body 30. The LED substrates 10A and 10B of the light source unit LU and the power supply circuit board 21 of the power supply unit PU are electrically connected, and power is supplied from the power supply unit PU to the light source unit LU. Further, the power supply unit PU is connected to the power cable 41 inside the protective body 30, and power is supplied from an external power source via the power cable 41.

[0017] The protective body 30 includes a protective tube 31, and retaining cases 32, 33 and sealing caps 34, 35 positioned at both ends of the protective tube 31.

[0018] The protective tube 31 is, for example, a translucent cylindrical member, formed from a light-transmitting material such as glass or resin. "Translucent" includes milky white and translucent. For example, polycarbonate resin can be used as the molding material for the protective tube 31. Both ends of the protective tube 31 are closed by retaining cases 32, 33 and sealing caps 34, 35. The protective tube 31 transmits a portion of the light emitted from the LED elements 15A and 15B and reflects the rest.

[0019] The retaining cases 32 and 33 have a cylindrical shape and are made of a resin material such as ABS resin. Similarly, the sealing caps 34 and 35 have a bowl shape and are made of a resin material such as ABS resin. It is preferable that the retaining cases 32 and 33 and the sealing caps 34 and 35 are made of a material that has thermal conductivity.

[0020] The retaining cases 32 and 33 are fitted to both ends of the protective tube 31, for example, and are fixed to the protective tube 31 by tightening the tightening rings 36 and 37 from the axial center side. A sealing member such as an O-ring (not shown) is placed between the retaining cases 32 and 33 and the tightening rings 36 and 37 to ensure watertightness.

[0021] Suspension arms 32a and 33a are provided on a portion of the outer circumference of the holding cases 32 and 33 so as to protrude outward. The suspension arms 32a and 33a are fastened to a fixing piece 51a of the flat chassis 51 by fastening members (not shown in the reference numerals), such as screws. When the chassis 51 is fixed to the installation surface C of the tunnel ceiling, the lighting device 1 is held suspended from the ceiling via the suspension arms 32a and 33a.

[0022] The sealing caps 34 and 35 are fastened, for example, to the retaining cases 32 and 33. A sealing member (not shown) such as an O-ring is placed between the sealing caps 34 and 35 and the retaining cases 32 and 33 to ensure watertightness. One of the sealing caps 34 is provided with a cable insertion section 42 through which the power cable 41 is drawn. The power cable 41 is drawn into the protective tube 31 via the cable insertion section 42 and connected to the power supply unit PU.

[0023] Furthermore, heat dissipation plates 38 and 39 are fitted inside the retaining cases 32 and 33. Specifically, the heat dissipation plates 38 and 39 are fastened by screws to mounting pieces 32c and 33c which are integrally provided on the retaining cases 32 and 33, and heat is dissipated from the power supply circuit board 21 via the heat dissipation plates 38 and 39 and the retaining cases 32 and 33. The heat dissipation plates 38 and 39 have a disc shape and are made of a thermally conductive material such as anodized aluminum. Note that the heat dissipation plates 38 and 39 are not limited to a disc shape, but can be rectangular, elliptical, or any other shape as long as they can be fastened to the mounting pieces 32c and 33c.

[0024] The power supply unit PU includes 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 LED boards 10A and 10B. The power supply module 22 only needs to be capable of supplying power to the LED elements 15A and 15B mounted on the LED boards 10A and 10B, and can be composed of, for example, a DC power supply circuit.

[0025] 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 and 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. In other words, when the lighting device 1 is installed on the 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 and 39 are joined via heat-conductive joining means or joining members, such as welding or fastening with screws.

[0026] The light source unit LU has two LED boards 10A and 10B. The LED boards 10A and 10B are printed circuit boards on which power lines to LED elements 15A and 15B are formed. The LED boards 10A and 10B are arranged to extend along the axial direction of the lighting device 1. The LED boards 10A and 10B are elongated boards having a roughly L-shaped cross-section, and are divided at the bend into LED mounting board sections 11A and 11B (first board section) and fixed board sections 12A and 12B (second board section).

[0027] The LED mounting board sections 11A, 11B and the fixed board sections 12A, 12B are formed, for example, by bending a single printed circuit board at a board bending angle θ1. The angle between the optical axes 14A, 14B and the vertical direction is the same as the board bending angle θ1 of the LED boards 10A, 10B (see Figure 6B). The board mounting angle θs, which is the angle between the LED mounting board sections 11A, 11B and the fixed board sections 12A, 12B, is expressed as 180°-θ1 using the board bending angle θ1.

[0028] Multiple LED elements 15A and 15B are arranged linearly on the LED mounting board sections 11A and 11B, respectively. The arrangement direction of the LED elements 15A and 15B coincides with the tube axis of the lighting device 1. The LED elements 15A and 15B may be arranged in a single row or in multiple rows in a two-dimensional arrangement.

[0029] In each of the LED mounting substrates 11A and 11B, the optical axis directions of the multiple LED elements 15A and 15B mounted are the same and are typically perpendicular to the LED mounting surface. The LED mounting substrates 11A and 11B are arranged such that their respective LED mounting surfaces face opposite each other with respect to the longitudinal cross-section along the tube axis of the lighting device 1, that is, the LED elements 15A and 15B mounted on the LED mounting substrates 11A and 11B illuminate different areas. It can also be said that the LED mounting substrates 11A and 11B are arranged so that the non-mounted surfaces of the LED elements 15A and 15B face each other.

[0030] Furthermore, the LED mounting boards 11A and 11B are positioned at an angle with respect to the fixed boards 12A and 12B. Specifically, the open ends of the LED mounting boards 11A and 11B, opposite to the power supply circuit board 21 side (fixed boards 12A and 12B side), are inclined so that they are close to each other. Since the fixed boards 12A and 12B are fixed parallel to the power supply circuit board 21 and, consequently, to the chassis 51, it can be said that the LED mounting boards 11A and 11B are positioned at an angle with respect to the mounting surface C. Also, in a cross-section perpendicular to the tube axis of the lighting device 1, the optical axes of the LED elements 15A and 15B intersect each other. The LED boards 10A and 10B are provided symmetrically, for example, with respect to a vertical cross-section along the tube axis of the lighting device 1.

[0031] The fixed substrate sections 12A and 12B 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 fixed substrate sections 12A and 12B are parallel to the power supply circuit board 21. In other words, in this embodiment, the power supply circuit board 21 functions as a support for the light source unit LU relative to the protective body 30.

[0032] The light source unit LU is held suspended from the power supply circuit board 21. A space is formed between the power supply circuit board 21 and the LED boards 10A and 10B (fixed board sections 12A and 12B). This allows the heat generated when the LED elements 15A and 15B are driven to be efficiently dissipated.

[0033] Furthermore, the light source unit LU has phosphorescent bodies 71 and 72 that emit light even when the LED elements 15A and 15B are not illuminating the light, such as during a power outage or when the power is off. The phosphorescent bodies 71 and 72 mainly absorb the reflected light that is reflected by the protective tube 31 from the light emitted from the LED elements 15A and 15B and store it as energy. The mounting configuration of the phosphorescent bodies 71 and 72 is not particularly limited and should be placed in an area that does not obstruct the light emitted from the LED elements 15A and 15B.

[0034] The phosphorescent material 71 is positioned, for example, to protrude from the LED mounting substrates 11A and 11B. Specifically, one LED substrate 10B has a phosphorescent material mounting portion 13B (third substrate portion) connected to the LED mounting substrate 11B so as to be perpendicular to the fixed substrate portion 12B. The phosphorescent material 71 is positioned on both sides of the phosphorescent material mounting portion 13B. The light emitted from the LED elements 15A and 15B is not obstructed by the phosphorescent material 71. The phosphorescent material 71 can efficiently store light, and the phosphorescence of the phosphorescent material 71 can improve visibility.

[0035] The phosphorescent material 72 is placed on one side of the fixed substrate sections 12A and 12B. The side on which the phosphorescent material 72 is placed is the same side as the LED mounting side of the LED mounting substrate sections 11A and 12A. The light emitted from the LED elements 15A and 15B is not obstructed by the phosphorescent material 72. By providing the phosphorescent material 72, the viewing range (viewing angle) is expanded, and visibility is further improved by the phosphorescence of the phosphorescent material 72.

[0036] The phosphorescent bodies 71 and 72 have a flat plate shape and are the same length as the LED substrates 10A and 10B in the direction of the tube axis. Furthermore, the phosphorescent bodies 71 and 72 extend along the direction of the tube axis, and are positioned so that the main surface of the flat plate shape faces the illumination side of the LED elements 15A and 15B. This allows them to efficiently receive and store the reflected light reflected by the protective tube 31.

[0037] The phosphorescent bodies 71 and 72 are composed of molded articles made of, for example, a phosphorescent material. Known phosphorescent materials such as strontium aluminate can be used as the phosphorescent material. In this case, the phosphorescent energy can be easily increased simply by increasing the volume of the phosphorescent bodies 71 and 72. Therefore, compared to phosphorescent bodies in which a phosphorescent sheet is attached to the surface of the substrate or a phosphorescent paint is applied, the luminescence duration can be extended, and the phosphorescent brightness is also increased, improving visibility.

[0038] The phosphorescent bodies 71 and 72 are attached to the phosphorescent body mounting portion 13B and the fixed substrate portions 12A and 12B, for example, by heat-resistant adhesive tape (not shown).

[0039] In the lighting device 1, the optical axis directions of the LED elements 15A and 15B are inclined with respect to the vertical and horizontal directions, so that the AA light distribution characteristics of the lighting device 1 provide a predetermined luminous intensity over a wide area (see Figure 7). Therefore, by installing the lighting device 1 on the ceiling of the tunnel so that the pipe axis is perpendicular to the tunnel axis direction, that is, so that the AA light distribution is applied in the direction of the tunnel axis, a wide area can be illuminated in the direction of the tunnel axis. Furthermore, when installing multiple lighting devices 1 at predetermined intervals in the direction of the tunnel axis, the number of lighting devices 1 can be reduced, thereby reducing equipment construction costs. In addition, sufficient brightness can be ensured even at points far from the lighting device 1 (for example, intermediate point P1 (see Figure 6A)).

[0040] In particular, if two adjacent lighting devices 1 are installed so that their respective optical axis directions intersect near the midpoint P1, the distance L between the lighting devices 1 can be extended to its maximum extent. For example, if the peak angle θp of the AA light distribution of lighting device 1 is 75° and the installation height H of lighting device 1 is 2.1m, then lighting device 1 should be installed with the midpoint P1 being approximately 8m (=2.1 × tan75°) horizontally from lighting device 1.

[0041] Basically, the peak angle θp of the AA light distribution is considered to coincide with the angle θ1 in the optical axis direction of the LED elements 15A and 15B, that is, the substrate bending angle θ1. Therefore, in conventional lighting devices, the substrate bending angle θ1 of the LED substrates 10A and 10B, that is, the optical axis direction of the LED elements 15A and 15B, is designed based on the target peak angle θ2 of the AA light distribution (θ1=θ2). However, the inventors have investigated and found that the actual light distribution peak angle θp may deviate from the target peak angle θ2, and that the desired light distribution characteristics may not be obtained with a design method that makes the substrate bending angle θ1 the same as the target peak angle θ2.

[0042] Figure 8 shows an example of the relationship between the substrate bending angle θ1 and the actual light distribution peak angle θp. As shown in Figure 8, when the protective tube 31 is absent, the substrate bending angle θ1 and the actual light distribution peak angle θp match well. This indicates that the desired light distribution characteristics can be obtained by setting the substrate bending angle θ1 to be the same as the target peak angle θ2. Although not shown in Figure 8, even when the protective tube 31 is present, if the protective tube 31 is transparent, the same results as when the protective tube 31 is absent were obtained.

[0043] On the other hand, when the protective tube 31 is present, the substrate bending angle θ1 and the actual light distribution peak angle θp do not coincide, and the light distribution peak angle θp is 10 to 15° smaller than the substrate bending angle θ1. In other words, the actual light distribution peak angle θp is 10 to 15° smaller than the target peak angle θ2, and the desired light distribution characteristics are not obtained. In the case of a translucent (e.g., milky white or semi-transparent) protective tube 31, it is thought that the light path is disturbed when the light emitted from the LED elements 15A and 15B passes through the protective tube 31, causing the angle of incidence and the angle of emission of the light to be different, resulting in refraction.

[0044] Therefore, in this embodiment, the substrate bending angle θ1 is set to be larger than the target peak angle θ2 of the AA light distribution, taking into account the refraction of light emitted from the LED elements 15A and 15B in the protective tube 31. Specifically, the substrate bending angle θ1 is set to satisfy θ2+10°≦θ1≦θ2+15°. This makes it easy to match the actual peak angle θp of the AA light distribution to the target peak angle θ2, and to realize a lighting device 1 having the desired light distribution characteristics (target peak angle θ2).

[0045] Furthermore, in this embodiment, the bending angle θ1 of the LED substrates 10A and 10B is set to satisfy 50° < θ < 90°. Figure 9 is a diagram showing an example of the relationship between the substrate bending angle θ1 and the minimum and average illuminance on the floor. Figure 9 shows the minimum and average illuminance when two lighting devices 1 are installed on the ceiling of a tunnel with a distance of 16m between the fixtures. The minimum and average illuminances shown in Figure 9 are simulation results when the tunnel width is 2.1m, the height from the lighting device 1 to the floor is 2.1m, the maintenance factor is 0.7, and the reflectance is 1.4. The minimum illuminance on the floor is, for example, the illuminance at the midpoint P1 (see Figure 6A) between the two lighting devices 1.

[0046] Generally, for a floor to be walkable, the minimum illuminance on the floor surface must be 2.25 lx or higher. As shown in Figure 9, when the substrate bending angle θ1 of the lighting device 1 is greater than 50°, the minimum illuminance on the floor surface is 2.25 lx or higher. This is thought to be because when the substrate bending angle θ1 is 50° or less, the peak angle θp in the AA light distribution approaches 0°, and when the lighting device 1 is installed on the ceiling, it points almost vertically downward. Also, the average illuminance required for very rough, short-term work outdoors is 10 lx (JIS Z 9110:2010). As shown in Figure 9, when the substrate bending angle θ1 of the lighting device 1 is less than 90°, the average illuminance is 10 lx or higher. Therefore, it is preferable that the substrate bending angle θ1 of the LED substrates 10A and 10B satisfy 50° < θ1 < 90°.

[0047] As described above, the lighting device 1 according to the embodiment has the following features. Specifically, the lighting device 1 according to the embodiment is a straight-tube type lighting device that is installed on the installation surface C of a culvert and irradiates light on the opposite side from the installation surface C, and comprises a plurality of LED elements 15A, 15B, two LED substrates 10A, 10B on which the plurality of LED elements 15A, 15B are arranged along the tube axis direction and which are arranged so that the non-mounted surfaces of the LED elements 15A, 15B face each other, and a translucent (for example, milky white or semi-transparent) protective tube 31 that houses the LED substrates 10A, 10B, and the LED substrates 10A, 10B have LED mounting substrate portions 11A, 11B (first substrate portion) on which the LED elements 15A, 15B are mounted, and fixed substrate portions 12A, 12B (second substrate portion) formed by bending the LED mounting substrate portions 11A, 11B at a predetermined substrate bending angle θ1. The substrate bending angle θ1 is set to 50° < θ1 < 90°, and is greater than the target peak angle θ2 for AA light distribution, taking into account the refraction of light emitted from the LED elements 15A and 15B in the protective tube 31.

[0048] Specifically, in the lighting device 1, the substrate bending angle θ1 satisfies θ2 + 10° ≤ θ1 ≤ θ2 + 15°.

[0049] According to the lighting device 1, the actual peak angle θp of the AA light distribution can be easily matched to the target peak angle θ2, making it possible to realize a lighting device with the desired light distribution characteristics (target peak angle θ2). Furthermore, light can be irradiated on both sides of the tube axis, and by installing the lighting device 1 so that the tube axis is perpendicular to the tunnel axis direction, the illuminance can be increased over a wide area in the tunnel axis direction.

[0050] In the lighting device 1, the protective tube 31 is made of polycarbonate. In this case, the refraction of light emitted from the LED elements 15A and 15B in the protective tube 31 becomes significant, but by setting the substrate bending angle θ1 as described above, the actual peak angle θp of the AA light distribution can be easily matched to the target peak angle θ2.

[0051] In the lighting device 1, one LED substrate 13B has a phosphorescent material mounting section 13B (third substrate section) connected to the LED mounting substrate section 11B (first substrate section) so as to be perpendicular to the fixed substrate section 12B (second substrate section), and phosphorescent materials 71 are arranged on both sides of the phosphorescent material mounting section 13B. This allows the phosphorescent material 71 to be easily positioned and to be charged with light without obstructing the irradiation of light from the LED elements 15A and 15B. Therefore, the phosphorescent material 71 can be charged with light efficiently, and the visibility due to the phosphorescence of the phosphorescent material 71 can be improved, making it suitable as a good visible sign when the lights are off.

[0052] Furthermore, in the lighting device 1, the phosphorescent material 72 is placed on the fixed substrate sections 12A and 12B (second substrate section). This allows the phosphorescent material 72 to be easily placed, and it can store light in the phosphorescent material 72 without obstructing the irradiation of light from the LED elements 15A and 15B, and the light-emitting area of ​​the phosphorescent material 72 is also increased. Therefore, the visibility due to the phosphorescence of the phosphorescent materials 71 and 72 is further improved.

[0053] Although the present invention has been specifically described above based on embodiments, the present invention is not limited to the above embodiments and can be modified without departing from its spirit.

[0054] For example, as the phosphorescent bodies 71 and 72, a phosphorescent sheet containing a phosphorescent material may be attached to the surface of a resin or metal substrate, or a phosphorescent paint may be applied. In addition, the retaining cases 32 and 33 and / or the sealing caps 34 and 35 may also be made phosphorescent in addition to the phosphorescent bodies 71 and 72.

[0055] Alternatively, for example, in the lighting device 1, a heat sink may be attached to the power supply circuit board 21 via a spacer 23, and the fixing board portions 12A and 12B of the LED boards 10A and 10B may be fixed to this heat sink. In this case, the heat sink, rather than the power supply circuit board 21, is joined to the heat dissipation plates 38 and 39 and functions as a support for the light source unit LU. The heat sink is formed of a metal material such as aluminum that has thermal conductivity.

[0056] The heat generated when the LED elements 15A and 15B are driven is transferred as a heat flow through the heat sink and efficiently dissipated to the outside via the heat dissipation plates 38 and 39 and the holding cases 32 and 33. Therefore, the limitations imposed by the heat generated by the LED elements 15A and 15B during operation are alleviated, making it possible to increase the number of LED elements mounted or increase the driving power, thus facilitating a high-brightness design for the lighting device 1. Furthermore, with the high-brightness design of the lighting device 1, the amount of light incident on the phosphorescent materials 71 and 72 increases, and the phosphorescence duration is extended, making it suitable as an emergency exit sign.

[0057] Furthermore, although the embodiment described the case in which the lighting device 1 is installed on the ceiling of the tunnel, the lighting device 1 may also be installed on the side wall of the tunnel. In addition, in a tunnel that extends vertically, the lighting devices may be installed at predetermined intervals in the vertical direction.

[0058] Furthermore, the board bending angle θ1 of the two LED boards 10A and 10B may be the same or different. Moreover, the board bending angle θ1 may be variable by connecting the LED mounting board sections 11A and 11B and the fixed board sections 12A and 12B via a hinge structure. In this case, the illumination range of the lighting device in the tunnel axis direction becomes variable, so the required brightness can be easily secured by adjusting the board bending angle θ1 according to the number of lighting devices that can be installed. In addition, the illumination range can be changed after the lighting device has been installed.

[0059] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0060] 1. Lighting device 10A, 10B LED board 11A, 11B LED mounting board section (first board section) 12A, 12B Fixed board part (second board part) 13B Luminous material mounting section (third substrate section) 15A, 15B LED elements 31 Protection tube 71, 72 Luminous material

Claims

1. A straight-tube type lighting device that is installed on the installation surface of a culvert and irradiates light on the opposite side from the installation surface, Multiple LED elements, Multiple LED elements are arranged along the tube axis direction, and two LED substrates are arranged so that the non-mounted sides of the LED elements face each other, It comprises a translucent protective tube that houses the LED substrate, The LED substrate has a first substrate portion on which the LED elements are mounted, and a second substrate portion formed by bending the first substrate portion at a predetermined substrate bending angle θ1. The substrate bending angle θ1 is set to be greater than the target peak angle θ2 for A-A light distribution, taking into account the refraction of light emitted from the LED element in the protective tube. Lighting device.

2. The bending angle θ1 of the substrate satisfies θ2 + 10° ≤ θ1 ≤ θ2 + 15°. The lighting device according to claim 1.

3. The protective tube is made of polycarbonate. The lighting device according to claim 1.

4. One of the LED substrates has a third substrate portion connected to the first substrate portion so as to be perpendicular to the second substrate portion, A phosphorescent material is arranged on both sides of the third substrate portion. The lighting device according to claim 1.

5. A phosphorescent material is arranged on the second substrate portion. The lighting device according to claim 1.

Images