Low-position lighting device, and road lighting method using the low-position lighting device

Abstract

To provide a low-position illumination device that easily equalizes illuminance on a back side and a front side in a width direction on a road.SOLUTION: A low-position illumination device 1 is installed at a low position beside a road 2 comprising one or more lanes 5. The low-position illumination device 1 comprises a first illumination unit, and a second illumination unit. The first illumination unit applies first illumination light C1 to a back side in a width direction M2 of the road 2 on the road 2 out of the one or more lanes 5. The second illumination unit applies second illumination light C2 to a front side in the width direction M2 on the road 2 out of the one or more lanes 5.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure generally relates to a low-position lighting device and a road lighting method using the low-position lighting device, and more particularly to a low-position lighting device installed at a low position on the side of a road and a road lighting method using the low-position lighting device.

Background Art

[0002] The LED road lighting described in Patent Document 1 is installed at a low position on the side of a road. The LED road lighting includes an LED light-emitting unit and a guiding unit. The LED light-emitting unit is disposed inside the housing of the LED road lighting. The guiding unit is disposed inside the housing and guides a part of the light irradiated by the LED light-emitting unit from inside the housing to the road.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above LED road lighting, the LED light-emitting unit and the guiding unit constitute one lighting unit. And in the above LED road lighting, one lighting unit illuminates the back side and the front side in the width direction of the road. Therefore, it is difficult to make the illuminance uniform between the back side and the front side in the width direction of the road.

[0005] An object of the present disclosure is to provide a low-position lighting device that can easily make the illuminance uniform between the back side and the front side in the width direction of a road, and a road lighting method using the low-position lighting device.

Means for Solving the Problems

[0006] A low-position lighting device according to one aspect of the present disclosure is a low-position lighting device installed at a low position beside a road having one or more lanes. The low-position lighting device comprises a first lighting unit and a second lighting unit. The first lighting unit illuminates the one or more lanes on the far side in the width direction of the road with first lighting light. The second lighting unit illuminates the one or more lanes on the near side in the width direction of the road with second lighting light. The second horizontal beam angle of the second illumination light is greater than the first horizontal beam angle of the first illumination light. The second illumination light includes two constituent luminous fluxes. The illumination ranges of the two constituent luminous fluxes are connected to each other, offset from each other in the direction in which the road is laid. The rear portion of the connecting part of the illumination ranges of each of the two constituent luminous fluxes is constricted. The front end of the first illumination range of the first illumination light extends into the second illumination range of the second illumination light and overlaps with the rear portion of the connecting part.

[0007] A road lighting method using a low-position lighting device according to one aspect of the present disclosure is a road lighting method using a low-position lighting device that is installed at a low position beside a road having one or more lanes and comprises a first lighting unit and a second lighting unit. In the road lighting method using the low-position lighting device, the first illumination light of the first lighting unit is directed to the far side of the road in the width direction of the one or more lanes, and the second illumination light of the second lighting unit is directed to the near side of the road in the width direction of the one or more lanes. The second horizontal beam angle of the second illumination light is greater than the first horizontal beam angle of the first illumination light. The second illumination light includes two constituent luminous fluxes. The illumination ranges of the two constituent luminous fluxes are connected to each other, offset from each other in the direction in which the road is laid. The rear portion of the connecting part of the illumination ranges of each of the two constituent luminous fluxes is constricted. The front end of the first illumination range of the first illumination light extends into the second illumination range of the second illumination light and overlaps with the rear portion of the connecting part. [Effects of the Invention]

[0008] According to this disclosure, there is an advantage in that the illumination can be made uniform on both the far and near sides of the road in the width direction, and it is possible to widely accommodate road conditions with different road shoulder widths, number of lanes, and installation intervals by combining the light distribution of several types of lighting units in any ratio. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view showing the low-position lighting device according to the first embodiment illuminating the road surface. [Figure 2] Figure 2 is a perspective view of the low-position lighting device shown above. [Figure 3] Figure 3 is a partially exploded perspective view of a portion of the low-position lighting device shown above. [Figure 4] Figure 4 is a cross-sectional view taken along line IV-IV of Figure 1. [Figure 5] Figure 5 is a top view of Figure 1. [Figure 6] Figure 6 is a magnified view of a portion of Figure 3. [Figure 7] Figure 7 is a cross-sectional view taken along line VII-VII in Figure 2. [Figure 8] Figure 8 is a perspective view showing the low-position lighting device according to the second embodiment illuminating the road surface. [Figure 9] Figure 9 is a top view of Figure 8. [Figure 10] Figure 10 is a perspective view of the main components (first lighting unit and second lighting unit) of the low-position lighting device shown above. [Figure 11] Figure 11 is a cross-sectional view of the same low-position lighting device, taken in a cross-section perpendicular to the left-right direction. [Figure 12] Figure 12A is a perspective view of the lens body from the front. Figure 12B is a perspective view of the lens body from the rear. Figure 12C is a cross-sectional view of Figure 12A along the line X1-X1. [Modes for carrying out the invention]

[0010] A low-position lighting device according to an embodiment of the present disclosure will be described with reference to the drawings. The figures described in the embodiments below are schematic diagrams, and the ratios of the size and thickness of each component in the figures do not necessarily reflect the actual dimensional ratios.

[0011] (First Embodiment) (1) Overview As shown in Figure 1, the low-position lighting device 1 according to the first embodiment is installed at a low position beside a road 2 having one or more lanes 5 (51-54). The low-position lighting device 1 comprises a first lighting unit 11 and a second lighting unit 12 (see Figure 7). The first lighting unit 11 illuminates the far side of the road 2 in the width direction M2 of one or more lanes 5 with first illumination light C1. The second lighting unit 12 illuminates the near side of the road 2 in the width direction M2 of one or more lanes 5 with second illumination light C2.

[0012] According to this configuration, the first lighting unit 11 and the second lighting unit 12 illuminate the above-mentioned rear side and the above-mentioned front side with separate illumination lights (the first illumination light C1 and the second illumination light C2). Therefore, it is easy to make the illuminance uniform on the above-mentioned rear side and the above-mentioned front side.

[0013] (2) Detailed configuration Referring to FIGS. 1 to 6, the detailed configuration of the low-position lighting device 1 according to the first embodiment will be described.

[0014] In the following description, as shown in FIG. 1 and the like, the direction in which the road 2 is laid (that is, the longitudinal direction of the road 2) is described as the laying direction M1, and the width direction of the road 2 is described as the width direction M2. Also, the front, rear, left, right, up, and down of the low-position lighting device 1 will be described as the front, rear, left, right, up, and down in FIG. 1. The front side of the low-position lighting device 1 is the road 2 side, and the rear side of the low-position lighting device 1 is the side opposite to the road 2 side. The left side of the low-position lighting device 1 is the side in the traveling direction of the road 2 (the direction in which the automobile travels). The right side of the low-position lighting device 1 is the side opposite to the left side of the low-position lighting device 1. Also, in the width direction M2 of the road 2, the side on which the low-position lighting device 1 is installed is described as the front side, and the opposite side is described as the rear side. The left-right direction of the low-position lighting device 1 coincides with the laying direction M1, and the front-rear direction of the low-position lighting device 1 coincides with the width direction M2.

[0015] As shown in Fig. 1, the low-position lighting device 1 is installed at a low position on the side of a road 2 having one or more lanes 5 (for example, four lanes), and irradiates the one or more lanes 5 with illumination light (first illumination light C1 and second illumination light C2) to illuminate the one or more lanes 5. The low position is, for example, a height of 2 m or less (more preferably 1.2 m) from the road surface 3 of the road 2. More specifically, a plurality of low-position lighting devices 1 are installed at equal intervals along the laying direction M1 of the road 2 at a low position on the side of the road 2. And each low-position lighting device 1 illuminates a plurality of lanes 5 included within a specified range H1 in the laying direction M1 of the road 2. Here, the specified range H1 is a range set for each low-position lighting device 1, and is a range within a certain width (for example, 4 m, 6 m or 8 m) centered on the installation position of the low-position lighting device 1 in the laying direction M1. Note that the installation position of the low-position lighting device 1 is the central position of the low-position lighting device 1 on the upper surface of the side wall 4.

[0016] (2-1) Details of the road As shown in Fig. 1, the road 2 is, for example, a highway, but is not limited to a highway. The road 2 has a road surface 3 and side walls 4.

[0017] The road surface 3 has a plurality (four in the illustrated example) of lanes 5 and a roadside strip 6. Here, the lane 5 is a route designated for the passage of automobiles. The roadside strip 6 is a strip-shaped passage zone at the end of the road 2 provided connected to the carriageway (lane 5).

[0018] The plurality of lanes 5 are arranged side by side in the width direction M2 of the road 2. In the illustrated example, the number of lanes 5 is four, but may be any number of one or more. The widths of the four lanes 5 in the width direction M2 are the same as each other, for example, 3.5 m. When distinguishing the four lanes 5, the four lanes 5 are described as lane 51, lane 52, lane 53, and lane 54 from the back side to the front side.

[0019] The shoulder 6 is located at the side wall 4 side of the road surface 3 (i.e., between the lane 54 closest to the side wall 4 among the four lanes 5 and the side wall 4, as described later). The width M2 of the shoulder 6 is set to a width of, for example, 0.5m to 4.5m, depending on the specifications required for the road 2.

[0020] The side wall 4 is connected to the near end of the road surface 3 and is provided along the laying direction M1 of the road surface 3. The side wall 4 is, for example, a wall railing and has a predetermined height (approximately 1.1m) above the road surface 3. Therefore, the upper surface of the side wall 4 is at a low position.

[0021] (2-2) Details of the low-position lighting device As shown in Figure 1, the low-position lighting device 1 is installed at a low position beside the road 2, on the upper surface (height 1.1m) of the side wall 4 of the road 2, and illuminates the road surface 3 of the road 2 by shining illumination light (first illumination light C1 and second illumination light C2) onto the road surface 3 of the road 2.

[0022] As shown in Figures 2 and 3, the low-position lighting device 1 comprises a housing 10, a first lighting unit 11, a second lighting unit 12, and a power supply unit 13, among other things.

[0023] The housing 10 houses the first lighting unit 11, the second lighting unit 12, and the power supply unit 13, etc. The housing 10 is, for example, a rectangular box. More specifically, the housing 10 is, for example, a rectangular box that is elongated horizontally along the left-right direction (i.e., the laying direction M1 of the road 2) and has a flattened (i.e., relatively thin) width in the front-to-back direction (i.e., the width direction M2).

[0024] The enclosure 10 comprises an enclosure body 17 and a front cover 18.

[0025] The housing body 17 is a rectangular box shape with an open front, and has a rear wall 17a, an upper wall 17b, a lower wall 17c, a right wall 17d, and a left wall 17e. The first lighting unit 11, the second lighting unit 12, and the power supply unit 13 are fixed (for example, by screws) to the front of the rear wall 17a inside the housing body 17. The first lighting unit 11 and the second lighting unit 12 are arranged, for example, on the right half of the front of the rear wall 17a of the housing body 17. The first lighting unit 11 and the second lighting unit 12 are arranged vertically relative to each other, with the second lighting unit 12 positioned above the first lighting unit 11. The power supply unit 13 is located on the left half of the front of the rear wall 17a of the housing body 17.

[0026] The front cover 18 is a member that closes the front opening of the housing body 17 and is formed in a flat plate shape that is approximately the same shape and size (i.e., rectangular) as the front of the housing body 17. The front cover 18 has a first emission window 18a and a second emission window 18b. The first emission window 18a emits the first illumination light C1 emitted from the first illumination unit 11 from the inside to the outside of the housing 10. The first emission window 18a is located in front of the first illumination unit 11 on the front cover 18. The second emission window 18b emits the second illumination light C2 emitted from the second illumination unit 12 from the inside to the outside of the housing 10. The second emission window 18b is located in front of the second illumination unit 12 on the front cover 18. The second emission window 18b is located above the first emission window 18a. The first discharge window 18a and the second discharge window 18b are, for example, rectangular in shape, elongated horizontally in the left-right direction.

[0027] More specifically, the front cover 18 has a light-shielding plate 20 and a transparent plate 21 (see Figure 3). The light-shielding plate 20 is formed from a light-shielding material (e.g., metal or resin) and is a plate shape that is approximately the same shape and size (i.e., rectangular) as the front surface of the housing body 17. The light-shielding plate 20 has the first emission window 18a and the second emission window 18b described above. The transparent plate 21 is formed from a transparent material (e.g., transparent glass or resin) and is a plate shape that is approximately the same shape and size (i.e., rectangular) as the front surface of the light-shielding plate 20. The transparent plate 21 is fixed to the front surface of the light-shielding plate 20. As a result, the first emission window 18a and the second emission window 18b of the light-shielding plate 20 are blocked by the transparent plate 21.

[0028] The first lighting unit 11 emits first illumination light C1 through the first emission window 18a onto one or more of the farthest lanes 5 of the road 2 within a specified range H1 (for example, lanes 51, 52). As a result, the first lighting unit 11 illuminates the aforementioned farthest lanes 5 (51, 52) within the specified range H1 with the first illumination light C1.

[0029] The second lighting unit 12 illuminates one or more of the lanes 5 of the road 2 within the specified range H1 (for example, lanes 53 and 54) with the second illumination light C2 through the second emission window 18b. As a result, the second lighting unit 12 illuminates the aforementioned one or more lanes 5 (53 and 54) within the specified range H1 with the second illumination light C2.

[0030] It is desirable that the first illumination light C1 and the second illumination light C2 be limited to illuminating multiple lanes 51-54 within the specified range H1. More specifically, it is desirable that the first illumination light C1 be limited to illuminating one or more lanes 51,52 on the far side within the specified range H1, and that the second illumination light C2 be limited to illuminating one or more lanes 53,54 on the near side within the specified range H1. The purpose of limiting the illumination of the first illumination light C1 and the second illumination light C2 in this way is to prevent the first illumination light C1 and the second illumination light C2 from illuminating unnecessary areas of the road surface 3 (i.e., the area beyond lane 51 and the area in front of lane 54).

[0031] The first lighting unit 11 and the second lighting unit 12 are arranged side by side in the vertical direction. The second lighting unit 12 is positioned above the first lighting unit 11.

[0032] The power supply unit 13 converts the AC voltage supplied from an external AC power source (e.g., grid power) into a DC voltage, transforms the voltage value of the converted DC voltage to the required voltage value, and supplies the transformed DC voltage to the first lighting unit 11 and the second lighting unit 12. The first lighting unit 11 and the second lighting unit 12 illuminate the road surface 3 of the road 2 by emitting illumination light (first illumination light C1 and second illumination light C2) using the DC voltage supplied from the power supply unit 13.

[0033] (2-3) Details of the first and second illumination lights The details of the first illumination light C1 of the first illumination unit 11 and the second illumination light C2 of the second illumination unit 12 will be described with reference to Figures 4 and 5.

[0034] In the following explanation, the optical axis, illumination range, horizontal beam angle, and vertical beam angle of the first illumination beam C1 will be referred to as the first optical axis L1, the first illumination range N1, the first horizontal beam angle φ1, and the first vertical beam angle θ1, respectively. Similarly, the optical axis, illumination range, horizontal beam angle, and vertical beam angle of the second illumination beam C2 will be referred to as the second optical axis L2, the second illumination range N2, the second horizontal beam angle φ2, and the second vertical beam angle θ2, respectively.

[0035] Here, "illumination range" refers to the area (region) of the road surface 3 illuminated by the illumination light. "Horizontal beam angle" is the angle indicating the horizontal (i.e., lateral) spread of the illumination light. "Vertical beam angle" is the angle indicating the vertical (i.e., vertical) spread of the illumination light.

[0036] The first vertical beam angle θ1 of the first illumination light C1 (see Figure 4) is set such that the maximum width Q1 of the width direction M2 of the first illumination range N1 of the first illumination light C1 includes one or more lanes 51, 52 on the far side of the road 2 (see Figure 5). The first horizontal beam angle φ1 of the first illumination light C1 is set such that the maximum width P1 of the laying direction M1 of the first illumination range N1 includes the specified range H1 (see Figure 5). Note that A including B includes cases where both ends of range A coincide with both ends of range B, where both ends of range A are located outside both ends of range B, and where one end of range A coincides with one end of range B and the other end of range A is located outside the other end of range B.

[0037] The first lighting area N1 has an elongated shape, for example, where the width in the laying direction M1 narrows as you move from the far side to the near side in the width direction M2 of the road 2 (see Figure 5). The far side edge N1c of the first lighting area N1 is curved in an arc towards the far side. The ends P1a of the maximum width P1 in the laying direction M1 of the first lighting area N1 are located near the ends of the specified range H1 in one or more lanes 51, 52 (for example, lane 51) on the far side (see Figure 5). Also, the far end N1a in the width direction M2 of the first lighting area N1 is located near the far side edge 51s of lane 51 (see Figure 5). Furthermore, the near end N1b in the width direction M2 of the first lighting area N1 extends into lane 53 (see Figure 5). This overhang widens the width P11 (the front half of the first lighting area N1) of the laying direction M1 in lane 52 within the first lighting area N1, in a direction that matches the prescribed area H1 in lane 52.

[0038] In this way, the first vertical beam angle θ1 and the first horizontal beam angle φ1 of the first illumination light C1 are set. As a result, the first illumination light C1 can efficiently illuminate the entirety of one or more lanes 51, 52 on the far side within the specified range H1 (i.e., suppressing illumination of areas where the first illumination light C1 is not needed), reduce the occurrence of dark areas in areas where the first illumination light C1 is difficult to illuminate (for example, the corners 52a on the near side within the specified range H1 of lane 52), and illuminate more uniformly.

[0039] The second optical axis L2 of the second illumination light C2 of the second lighting unit 12 is directed downwards compared to the first optical axis L1 of the first illumination light C1 of the first lighting unit 11 (see Figure 4). The second vertical beam angle θ2 of the second illumination light C2 is set such that the maximum width Q2 of the width direction M2 of the second illumination range N2 of the second illumination light C2 includes one or more lanes 53, 54 on the near side of the road 2 (see Figure 5) (see Figure 4). The second horizontal beam angle φ2 of the second illumination light C2 is wider than the first horizontal beam angle φ1 of the first illumination light C1 (see Figure 5). As a result, the second horizontal beam angle φ2 is set such that the maximum width P2 of the laying direction M1 of the second illumination range N2 includes the specified range H1 (see Figure 5).

[0040] The second lighting area N2 has an elongated shape, for example, where the width in the laying direction M1 narrows as you move from the far side to the near side in the width direction M2 of the road 2 (see Figure 5). The far side edge N2c of the second lighting area N2 is curved in an arc towards the far side. The ends P2a of the maximum width P2 of the laying direction M1 of the second lighting area N2 are located near the ends of the specified range H1 in one or more lanes 53, 54 (for example, lane 53) on the near side. The far end N2a of the width direction M2 of the second lighting area N2 is located near the far side edge 53s of lane 53. The near end N2b of the width direction M2 of the second lighting area N2 is located near the near side edge 54s of lane 54.

[0041] In this way, the second vertical beam angle θ2 and the second horizontal beam angle φ2 of the second illumination light C2 are set. As a result, the second illumination light C2 can efficiently illuminate the entirety of one or more lanes 53, 54 on the near side within the specified range H1 (i.e., suppressing illumination of areas where the second illumination light C2 is not needed), reduce the occurrence of dark areas in areas where the second illumination light C2 is difficult to illuminate (for example, the corners 54a on the near side within the specified range H1 of lane 54), and illuminate more uniformly.

[0042] Furthermore, by illuminating one or more lanes 51, 52 on the far side and one or more lanes 53, 54 on the near side separately with different illumination lights (first illumination light C1 and second illumination light C2), it is possible to improve the lane axis uniformity and overall uniformity of each of the one or more lanes 5. Lane axis uniformity refers to the uniformity of illumination at positions taken at regular intervals along the centerline of each lane 5 within a specified range H1 for each lane 5. Overall uniformity refers to the uniformity of each lane 5 within a specified range H1 for each lane 5.

[0043] (2-4) Detailed configuration of the first lighting unit As shown in Figures 6 and 7, the first lighting unit 11 is fixed to the front of the rear wall 17a of the housing 10 via a substrate 22, together with the second lighting unit 12. The substrate 22 is made of metal and is, for example, a rectangular flat plate. The first lighting unit 11 and the second lighting unit 12 may be fixed directly to the front of the rear wall 17a without the substrate 22.

[0044] The first lighting unit 11 is a reflective surface type lighting unit. The first lighting unit 11 comprises a light source module 60, a heat dissipation section 70, a support member 80, and a reflector 90.

[0045] The light source module 60 emits light that forms the basis of the first illumination light C1. The light source module 60 has a plurality of light sources 61 and a circuit board 62. The plurality of light sources 61 emit light that forms the basis of the first illumination light C1. The plurality of light sources 61 are, for example, LEDs (light-emitting diodes) and are arranged in a line along the longitudinal direction (left-right direction) of the circuit board 62 on one main surface (bottom surface) of the circuit board 62.

[0046] The heat dissipation section 70 dissipates the heat generated by the light source module 60. The heat dissipation section 70 comprises a base section 71 and a plurality of heat sinks 72. The base section 71 and the plurality of heat sinks 72 are integrally formed.

[0047] The base portion 71 is a horizontally elongated, flat plate that is long in the left-right direction and has two main surfaces (upper and lower) that face each other in the vertical direction. The light source module 60 is fixed (for example, by screws) to the lower surface of the base portion 71.

[0048] Each of the multiple heat sinks 72 is a flat plate with a rectangular shape (e.g., trapezoidal shape) when viewed from a plan view from the left or right direction. Each of the multiple heat sinks 72 is provided on the upper surface of the base portion 71, with their thickness direction oriented in the left-right direction and spaced apart from each other in the left-right direction.

[0049] The support member 80 is a member for fixing the heat dissipation unit 70 to the substrate 22. The support member 80 has a support plate 81 and a fixing piece 82. The support plate 81 is a horizontally elongated plate that is long in the left-right direction and has two main surfaces (upper and lower surfaces) that face each other in the vertical direction. The support plate 81 has an opening 81a in which a plurality of heat dissipation plates 72 of the heat dissipation unit 70 are arranged. The opening 81a penetrates the support plate 81 in the vertical direction. The front edge portion 81s of the support plate 81 is folded back from the bottom to the rear in an L-shape. The fixing piece 82 is a portion for fixing (for example, by screw fixing) the support plate 81 to the front surface of the substrate 22. The fixing piece 82 is formed at the rear end of the support plate 81 along the longitudinal direction (left-right direction) of the rear end and protrudes upward. The heat dissipation unit 70 is fixed (for example, by screw fixing) to the lower surface of the support plate 81. In this fixed state, the light source module 60 provided on the lower surface of the heat dissipation section 70 is oriented downwards, and the multiple heat dissipation plates 72 of the heat dissipation section 70 protrude upwards from the opening 81a of the support plate 81.

[0050] The reflector 90 is positioned in front of (i.e., below) the light source module 60 and reflects the light from the light source module 60, converting it into the first illumination light C1. The reflector 90 has a reflector body 91 and a pair of left and right fixing pieces 92. The reflector body 91 and the fixing pieces 92 are integrally formed from metal or resin.

[0051] The reflective body 91 is a block having a reflective surface 91a that reflects light from the light source module 60 and converts it into first illumination light C1. More specifically, the reflective body 91 is a rectangular parallelepiped that is elongated in the left-right direction. The front surface of the reflective body 91 is the reflective surface 91a, and in a vertical cross-section, a concave curved surface is formed on the back side of the reflective surface 91a that is recessed in an arc shape. The light from the light source is converted into first illumination light C1 by reflection at this reflective surface 91a.

[0052] The pair of left and right fixing pieces 92 are for fixing (for example, by screw fixing) the reflective body 91 to the front surface of the substrate 22. The right fixing piece 92 protrudes to the right from the rear end of the right end face of the reflective body 91 and is fixed (for example, by screw fixing) to the front surface of the substrate 22. The left fixing piece 92 protrudes to the left from the rear end of the left end face of the reflective body 91 and is fixed (for example, by screw fixing) to the front surface of the substrate 22.

[0053] In the first lighting unit 11 configured in this way, reflected light from the reflective surface 91a can be efficiently extracted from the first emission window 18a. Therefore, the first lighting unit 11 can convert the light source from the light source module 60 into the first illumination light C1 more efficiently than a lens-type lighting unit.

[0054] (2-5) Detailed configuration of the second lighting unit As shown in Figures 6 and 7, the second lighting unit 12 is fixed to the front of the rear wall 17a of the housing 10 via the substrate 22, together with the first lighting unit 11 as described above.

[0055] The second lighting unit 12 is a lens-type lighting unit. The second lighting unit 12 comprises a unit body 100 that emits a second illumination light C2, and a support mechanism 160 that supports the unit body 100.

[0056] The support mechanism 160 supports the unit body 100 by fixing it so that its angle around the horizontal axis can be changed. In this way, the support mechanism 160 supports the unit body 100 by fixing the vertical irradiation angle of the second illumination light C2 so that it can be changed. The above irradiation angle is the angle that defines the irradiation direction of the second illumination light C2 (i.e., the same direction as the second optical axis L2 of the second illumination light C2) (for example, an angle with vertical downward as the reference).

[0057] The support mechanism 160 includes a support member 161, a pair of left and right first screws 162, and a pair of left and right second screws 163.

[0058] The unit body 100 is a component in which the light source 111 and the lens 33 are integrally assembled (i.e., a component in which the light source 111 and the lens 33 are fixed relative to each other). The unit body 100 comprises a light source module 110, a heat dissipation unit 120, a lens 33, and a mounting member 140.

[0059] The light source module 110 emits light from a light source that forms the basis of the second illumination light C2. The light source module 110 has a plurality of light sources 111 and a circuit board 112. The configuration of the light source module 110 (light sources 111 and circuit board 112) is the same as the configuration of the first illumination unit 11 of the first embodiment (light sources 61 and circuit board 62), so a detailed explanation of them is omitted.

[0060] The heat dissipation unit 120 (see Figure 7) dissipates the heat generated by the light source module 110. The heat dissipation unit 120 comprises a base portion 121 and a plurality of heat sinks 122. The configuration of the heat dissipation unit 120 (base portion 121 and heat sinks 122) is the same as the configuration of the heat dissipation unit 70 (base portion 71 and heat sinks 72) of the first lighting unit 11 of the first embodiment, so a detailed explanation of them is omitted. The light source module 110 is fixed (for example, by screw fixing) to one main surface (front) of the base portion 121 of the heat dissipation unit 120.

[0061] The mounting member 140 is a member that supports the heat dissipation section 120 on the support member 161 of the support mechanism 160 so that it can rotate around a horizontal axis. The mounting member 140 has a mounting plate 141 and a pair of left and right support pieces 142. The mounting plate 141 is a horizontally elongated plate that is long in the left-right direction and has two main surfaces (front and rear) that face each other in the front-rear direction. The mounting plate 141 has an opening 141a in which a plurality of heat dissipation plates 122 of the heat dissipation section 120 are arranged. The opening 141a penetrates the mounting plate 141 in the front-rear direction. The lower part 141d of the mounting plate 141 is folded back upward from the front in an L-shape. The upper part 141u of the mounting plate 141 is bent forward and protrudes. The pair of left and right support pieces 142 are parts that are supported by a pair of left and right support plates 165 of the support mechanism 160. In other words, the pair of left and right support pieces 142 are the parts into which the pair of left and right first screws 162 and the pair of left and right second screws 163 are screwed and fixed. The pair of left and right support pieces 142 protrude forward from both the left and right ends of the mounting plate 141. Each support piece 142 has a first screw hole 145 and a second screw hole 146 (see Figure 6).

[0062] The first screw hole 145 is a screw hole into which the first screw 162 is screwed and fixed, and is provided through each of the left and right support pieces 142 at a position corresponding to the central hole 168. The second screw hole 146 is a screw hole into which the second screw 163 is screwed and fixed, and is provided through each of the left and right support pieces 142 at a position a certain distance away from the first screw hole 145.

[0063] The heat dissipation unit 120 (see Figure 7) is fixed (for example, by screws) to the front of the mounting plate 141. In this state, the light source module 110 provided on the front of the heat dissipation unit 120 is facing forward, and the multiple heat dissipation plates 122 of the heat dissipation unit 120 protrude rearward from the opening 141a of the mounting plate 141.

[0064] The lens 33 is positioned in front of the light source module 110 and transmits (concentrates) the light from the light source module 110, converting it into a second illumination light C2. The lens 33 has a lens body 331 and a pair of upper and lower fixing parts 332. The lens body 331 and the fixing parts 332 are integrally formed. The lens body 331 is, for example, a meniscus cylindrical lens (for example, a convex meniscus cylindrical lens). The cross-sectional shape of the lens body 331 (i.e., the cross-sectional shape in a cross section perpendicular to the left-right direction) is, for example, an arc shape (for example, a semicircle shape). The pair of upper and lower fixing parts 332 are for fixing (for example, screw fixing) the lens body 331 to the front surface of the base part 121 of the heat dissipation part 120. The upper fixing part 332 is formed at the upper end of the lens body 331 along the longitudinal direction (left-right direction) of the upper end and protrudes upward. The lower fixing portion 332 is formed at the lower end of the lens body 331, along the longitudinal direction (left-right direction) of the lower end, and protrudes downward.

[0065] The lens 33 is fixed (for example, by screw fixing) to the front surface of the base portion 121 of the heat dissipation unit 120, so as to be positioned in front of the light source module 110.

[0066] In the second lighting unit 12 configured in this way, a pair of left and right first screws 162 are screwed into the left and right first screw holes 145 on each side of the heat dissipation unit 120 by passing through the central holes 168 on each side of the support mechanism 160 from each side. In addition, a pair of left and right second screws 163 are screwed into the left and right second screw holes 146 on each side of the heat dissipation unit 120 by passing through the elongated holes 169 on each side of the support mechanism 160 from each side.

[0067] To change the vertical irradiation angle (irradiation direction) of the second illumination light C2, the left and right first screws 162 and left and right second screws 163 are loosened. Then, the heat dissipation unit 120 is rotated around the left and right first screws 162 (i.e., around the horizontal axis) to the desired rotation position. At this time, the left and right second screws 163 move along the elongated holes 169 on the left and right sides of the support mechanism 160. Then, the left and right first screws 162 and left and right second screws 163 are tightened to fix the heat dissipation unit 120 in the desired rotation position. By changing the rotation position of the heat dissipation unit 120 in this way, it is possible to change the vertical irradiation angle (irradiation direction) of the second illumination light C2.

[0068] Thus, the second lighting unit 12 allows for a simple operation to change the vertical irradiation angle (irradiation direction) of the second illumination light C2 by simply loosening the screws (first screws 162 and second screws 163) and rotating the heat dissipation section 120 (i.e., a simple operation that only involves rotating the light source 111 and lens 33, which are fixed relative to each other). The lower limit angle of the second vertical beam distribution angle θ2 of the second illumination light C2 is set so that the light rays emitted in the direction of the lower limit angle are irradiated near the far side 6s (see Figure 5) of the roadside strip 6. Generally, the width M2 in the width direction of the roadside strip 6 differs depending on the specifications of the road 2. In this low-position lighting device 1, since the vertical irradiation angle of the second illumination light C2 can be easily changed in the second lighting unit 12, the vertical irradiation angle of the second illumination light C2 can be easily changed according to the width M2 in the width direction of the roadside strip 6. As a result, this low-position lighting device 1 can be easily installed and used on roads 2 of various specifications.

[0069] In this embodiment, the second screw 163 moves along the elongated hole 169, thereby changing the rotational position of the heat dissipation unit 120 around its horizontal axis (i.e., the vertical irradiation angle of the second illumination light C2). However, instead of the elongated hole 169, a plurality of selectable screw holes may be arranged in an arc shape. In this case, the second screw 163 is inserted through one of the multiple selectable screw holes and screwed into the second screw hole 146 of the unit body 100 to fix it in place. The rotational position of the heat dissipation unit 120 around its horizontal axis can be changed by selecting the appropriate selectable screw hole. After the change, the first screw 162 and the second screw 163 are tightened to fix the rotational position of the heat dissipation unit 120.

[0070] (3) Road lighting method using low-position lighting devices Functions similar to those of the low-position lighting device 1 according to the first embodiment may be realized in a road lighting method using the low-position lighting device 1 according to the first embodiment.

[0071] A road lighting method using a low-position lighting device according to one embodiment is a road lighting method using a low-position lighting device installed at a low position beside a road having one or more lanes, and comprising a first lighting unit and a second lighting unit. In this road lighting method, the first illumination light of the first lighting unit is directed to the far side of the road in the width direction of the one or more lanes. The second illumination light of the second lighting unit is directed to the near side of the road in the width direction of the one or more lanes.

[0072] (4) Variations Modifications of the first embodiment will now be described. In the following description, the same reference numerals are used for components that are the same as in the first embodiment, and their descriptions are omitted. The description will focus on the parts that differ from the first embodiment. It should be noted that the first embodiment and the modifications described later may be implemented in combination.

[0073] (4-1) Experimental variation 1 In the first embodiment, the second lighting unit 12 is exemplified as comprising a unit body 100 that emits a second illumination light C2 and a support mechanism 160 that fixes the unit body 100 so that its angle around the horizontal axis can be changed. However, at least one of the first lighting unit 11 and the second lighting unit 12 may also comprise a unit body that emits a first illumination light C1 or a second illumination light C2 and a support mechanism that fixes the unit body so that its angle around the horizontal axis can be changed.

[0074] (4-2) Modification 2 In the first embodiment, the first lighting unit 11 is a reflective surface type lighting unit, and the second lighting unit 12 is a lens type lighting unit. However, at least one of the first lighting unit 11 and the second lighting unit 12 may be a lens type lighting unit, or at least one of the first lighting unit 11 and the second lighting unit 12 may be a reflective surface type lighting unit.

[0075] (4-3) Modification 3 In the first embodiment, the second lighting unit 12 is positioned above the first lighting unit 11, but the second lighting unit 12 may also be positioned below the first lighting unit 11.

[0076] (4-4) Modification 4 In the first embodiment, the first lighting unit 11 and the second lighting unit 12 are arranged side by side in the vertical direction, but they may also be arranged side by side in the horizontal direction.

[0077] (4-5) Modification 5 In the first embodiment, the example is that the road 2 has four lanes 5, but the road 2 may have one or more lanes 5, two lanes 5, three lanes 5, or five or more lanes 5. If the road 2 has one lane 5, the first lighting unit 11 illuminates the far side of the lane 5 with the first illumination light C1, and the second lighting unit 12 illuminates the near side of the lane 5 with the second illumination light C2. If the road 2 has two lanes 5, the first lighting unit 11 illuminates the far lane 5 with the first illumination light C1, and the second lighting unit 12 illuminates the near lane 5 with the second illumination light C2. Furthermore, if the road 2 has three lanes 5, the first lighting unit 11 illuminates one or more of the farthest lanes 5 (for example, one of the farthest lanes 5) with the first illumination light C1, and the second lighting unit 12 illuminates one or more of the nearest lanes 5 (for example, two of the nearest lanes 5) with the second illumination light C2. If the road 2 has five lanes 5, the first lighting unit 11 illuminates one or more of the farthest lanes 5 (for example, two of the farthest lanes 5) with the first illumination light C1, and the second lighting unit 12 illuminates one or more of the nearest lanes 5 (for example, three of the nearest lanes 5) with the second illumination light C2.

[0078] (Second Embodiment) The low-position lighting device 1 according to the second embodiment will be described with reference to Figures 8 to 12. In the second embodiment, the same reference numerals are used for components that are the same as in the first embodiment, and their descriptions are omitted. The description will focus on the parts that differ from the first embodiment. The first embodiment, its modified form, and the second embodiment may be implemented in combination.

[0079] (1) Details of the second illumination light As shown in Figures 8 and 9, the low-position lighting device 1 according to the second embodiment is configured similarly to the low-position lighting device 1 according to the first embodiment, except that the second illumination range N2 of the second illumination light C2 has been changed to a batwing shape. The batwing shape is a shape in which, in a plan view, two mirror-image symmetrical shapes facing each other are connected to each other while being shifted in a direction away from each other, and the connection part is constricted.

[0080] In the second embodiment, the second illumination light C2 has two luminous beams (hereinafter referred to as "constituent luminous beams") C21 and C22 that constitute the second illumination light C2. The two constituent luminous beams C21 and C22 are emitted from the light source module 31 with their respective optical axes L21 and L22 (see Figure 9) shifted away from each other in the horizontal light distribution angle direction (in other words, the installation direction M1).

[0081] The second illumination range N2 is composed of the illumination ranges N21 and N22 of the two constituent luminous fluxes C21 and C22. Each illumination range N21 and N22 has a shape that is, for example, a mirror image of each other (i.e., a left-right symmetrical shape). Each illumination range N21 and N22 has an elongated shape in which the width in the laying direction M1 narrows as you move from the far side to the near side in the width direction M2 of the road 2. In addition, the contours of the far ends N21a and N22a of each illumination range N21 and N22 are curved in an arc shape. Each illumination range N21 and N22 is connected to each other with their respective optical axis positions K21 and K22 (see Figure 9) shifted away from each other in the horizontal light distribution angle direction (in other words, the laying direction M1). The optical axis positions K21 and K22 are the positions where the optical axes L21 and L22 intersect the road surface 3. The rear portion of the connecting section between each illumination range N21 and N22 (i.e., the central portion of the rear edge N2c of the second illumination range N2), N2d, is constricted.

[0082] As described above, the second illumination range N2 has a shape in which each illumination range N21 and N22 are connected to each other while being shifted away from each other in the horizontal light distribution angle direction (in other words, the laying direction M1). Therefore, the second illumination range N2 is wider in the laying direction M1 compared to the second illumination range N2 of the first embodiment. As a result, in the second embodiment, the second illumination range N2 can be further extended to the vicinity of the far corner 53a within the specified range H1 of lane 53 and the vicinity of the near corner 54a within the specified range H1 of lane 54. This makes it possible to illuminate the entirety of one or more lanes 53, 54 on the near side within the specified range H1 more uniformly than in the first embodiment.

[0083] Furthermore, in the second illumination range N2, as described above, the rear portion of the connecting part of each illumination range N21 and N22 (i.e., the central portion of the rear edge N2c of the second illumination range N2) N2d is constricted (i.e., it is recessed from the rear to the front). As explained in the first embodiment, the front end N1b of the first illumination range N1 protrudes into the lane 53 (i.e., into the second illumination range N2). In other words, the front end N1b of the first illumination range N1 overlaps with the second illumination range N2. However, as described above, the central portion N2d of the rear edge N2c of the second illumination range N2 is constricted. Therefore, the overlap between the second illumination range N2 and the front end N1b of the first illumination range N1 can be reduced. This prevents the illumination from becoming too bright in the overlapping area.

[0084] (2) Details of the second lighting unit Next, the configuration of the second lighting unit 12 of the second embodiment will be described with reference to Figures 10 and 11. In Figures 10 and 11, the first lighting unit 11 of the second embodiment has the same configuration as the first lighting unit 11 of the first embodiment, so the same reference numerals are used for the same components as in the first lighting unit 11 of the first embodiment, and detailed explanations are omitted.

[0085] The second illumination unit 12 of the second embodiment comprises a unit body 100 that emits a second illumination light C2, and a support mechanism 160 that supports the unit body 100.

[0086] The support mechanism 160 supports the unit body 100 by fixing it in a way that allows the angle of the unit body 100 around its horizontal axis to be changed. The support mechanism 160 has a support member 161, a pair of left and right first screws 162, and a pair of left and right second screws 163. The support member 161 has a pair of left and right support plates 165, a connecting plate 166, and a pair of left and right fixing pieces 167. Each support plate 165 has a central hole 168 and an elongated hole 169. Since the components of the support mechanism 160 (support member 161, first screw 162, second screw 163, support plate 165, connecting plate 166, fixing piece 167, central hole 168, and elongated hole 169) are the same as the components of the support mechanism 40 of the second lighting unit 12 in the first embodiment (support member 41, first screw 42, second screw 43, support plate 44, connecting plate 45, fixing piece 46, central hole 441, and elongated hole 442), a detailed explanation of them will be omitted.

[0087] The unit body 100 is a component in which the light source 111 and the lens 130 are integrally assembled (i.e., a component in which the light source 111 and the lens 130 are fixed relative to each other). The unit body 100 comprises a light source module 110, a heat dissipation unit 120, a lens 130, and a mounting member 140.

[0088] The light source module 110 emits light from a light source that forms the basis of the second illumination light C2. The light source module 110 has a plurality of light sources 111 and a circuit board 112. The configuration of the light source module 110 (light sources 111 and circuit board 112) is the same as the configuration of the second illumination unit 12 of the first embodiment (light sources 311 and circuit board 312), so a detailed explanation of them is omitted.

[0089] The heat dissipation unit 120 (see Figure 11) dissipates the heat generated by the light source module 110. The heat dissipation unit 120 comprises a base portion 121 and a plurality of heat sinks 122. The configuration of the heat dissipation unit 120 (base portion 121 and heat sinks 122) is the same as the configuration of the heat dissipation unit 70 (base portion 71 and heat sinks 72) of the first lighting unit 11 of the first embodiment, so a detailed explanation of them is omitted. The light source module 110 is fixed (for example, by screw fixing) to one main surface (front) of the base portion 121 of the heat dissipation unit 120.

[0090] The mounting member 140 is a member that supports the heat dissipation section 120 on the support member 161 of the support mechanism 160 so that it can rotate around a horizontal axis. The mounting member 140 has a mounting plate 141 and a pair of left and right support pieces 142. The mounting plate 141 is a horizontally elongated plate that is long in the left-right direction and has two main surfaces (front and rear) that face each other in the front-rear direction. The mounting plate 141 has an opening 141a in which a plurality of heat dissipation plates 122 of the heat dissipation section 120 are arranged. The opening 141a penetrates the mounting plate 141 in the front-rear direction. The lower part 141d of the mounting plate 141 is folded back upward from the front in an L-shape. The upper part 141u of the mounting plate 141 is bent forward and protrudes. The pair of left and right support pieces 142 are parts that are supported by a pair of left and right support plates 165 of the support mechanism 160. In other words, the pair of left and right support pieces 142 are the parts into which the pair of left and right first screws 162 and the pair of left and right second screws 163 are screwed and fixed. The pair of left and right support pieces 142 protrude forward from both the left and right ends of the mounting plate 141. Each support piece 142 has a first screw hole 145 and a second screw hole 146 (see Figure 10).

[0091] The first screw hole 145 is a screw hole into which the first screw 162 is screwed and fixed, and is provided through each of the left and right support pieces 142 at a position corresponding to the central hole 168. The second screw hole 146 is a screw hole into which the second screw 163 is screwed and fixed, and is provided through each of the left and right support pieces 142 at a position a certain distance away from the first screw hole 145.

[0092] The heat dissipation unit 120 is fixed (for example, by screws) to the front of the mounting plate 141. In this state, the light source module 110 provided on the front of the heat dissipation unit 120 is facing forward, and the multiple heat dissipation plates 122 of the heat dissipation unit 120 protrude rearward from the opening 141a of the mounting plate 141.

[0093] The lens 130 comprises multiple lens bodies 131 and connecting parts 132. The multiple lens bodies 131 and connecting parts 132 are integrally formed from the same material.

[0094] The connecting portion 132 connects multiple lens bodies 131. The connecting portion 132 is a horizontally elongated rectangular plate that is long in the left-right direction and has two main surfaces (front and rear) that face each other in the front-back direction.

[0095] The multiple lens bodies 131 correspond one-to-one with the multiple light sources 111 of the light source module 110, and convert the light from the corresponding light source 111 into two constituent luminous fluxes C21 and C22 before emission. The multiple lens bodies 131 are arranged at equal intervals along the longitudinal direction of the connecting portion 132 on the front surface of the connecting portion 132.

[0096] The lens body 131 is, for example, circular when viewed from the front. The front surface 131a of the lens body 131 is a spherical convex surface (Figure 12A). The rear surface 131b of the lens body 131 is concave in a columnar shape that is approximately isosceles when viewed from above, from the rear to the front (Figure 12A). More specifically, the rear surface 131b of the lens body 131 has an upper surface 131c, a lower surface 131d, a right side surface 131e, and a left side surface 131f (Figures 12B and 12C). The upper surface 131c and the lower surface 131d are approximately isosceles triangles of the same shape and size. The vertex corner 131g of the above approximately isosceles triangle faces the front surface 131a of the lens body 131 and is curved in an arc shape. The right side surface 131e is a plane that connects the right sides of the upper surface 131c and the lower surface 131d. The leading edge of the right side surface 131e is curved along the curvature of the apex corner 131g. The left side surface 131f is a plane connecting the left edges of the upper surface 131c and the lower surface 131d. The leading edge of the left side surface 131f is curved along the curvature of the apex corner 131g.

[0097] As described later, of the light source light incident on the rear surface 131b of the lens body 131, the light source light incident on the right side 131e becomes the luminous flux C22, which is shifted to the right of the two constituent luminous fluxes C21 and C22. Also, the light source light incident on the left side 131f becomes the luminous flux C21, which is shifted to the left of the two constituent luminous fluxes C21 and C22. By adjusting the narrow angle between the right side 131e and the left side 131f, it is possible to adjust the horizontal light distribution angle of the two constituent luminous fluxes C21 and C22.

[0098] The lens 130 is fixed (for example, by screws) to the front of the heat dissipation unit 120, with multiple lens bodies 131 positioned in front of the corresponding light sources 111.

[0099] In the second illumination unit 12 configured in this way, the light emitted from each light source 111 of the light source module 110 is incident on the rear surface 131b of the corresponding lens body 131. The light emitted from the light source incident on the right side surface 131e of the rear surface 131b passes through the lens body 131 and is emitted from the right half of the front surface 131a of the lens body 131. Similarly, the light emitted from the left side surface 131f of the rear surface 131b passes through the lens body 131 and is emitted from the left half of the front surface 131a of the lens body 131. The light emitted from the right half of the front surface 131a of each of the multiple lens bodies 131 is combined to form a luminous flux C22 that is shifted to the right of the two luminous fluxes C21 and C22 described above. Furthermore, the light from the light source emitted from the left half of the front surface 131a of each of the multiple lens bodies 131 is combined to form a constituent light beam C21 that is shifted to the left of the two constituent light beams C21 and C22 described above.

[0100] Furthermore, in the second lighting unit 12 configured in this way, similar to the second lighting unit 12 of the first embodiment, a pair of left and right first screws 162 are screwed into the first screw holes 145 on each side of the mounting member 140, passing through the central holes 168 of the support plates 165 on each side. Also, a pair of left and right second screws 163 are screwed into the second screw holes 146 on each side of the mounting member 140, passing through the elongated holes 169 of the support plates 165 on each side.

[0101] To change the vertical irradiation angle (irradiation direction) of the second illumination light C2, loosen the left and right first screws 162 and left and right second screws 163, as in the case of the second illumination unit 12 of the first embodiment. Then, rotate the heat dissipation unit 120 around the horizontal axis (i.e., the first screw 162) to the desired rotation position. Then, tighten the left and right first screws 162 and left and right second screws 163 to fix the heat dissipation unit 120 in the desired rotation position. By changing the rotation position of the heat dissipation unit 120 in this way, it is possible to change the vertical irradiation angle of the second illumination light C2.

[0102] Thus, in the second embodiment, as in the first embodiment, it is possible to change the vertical irradiation angle (irradiation direction) of the second illumination light C2 by simply loosening the screws (first screw 162 and second screw 163) and rotating the heat dissipation section 120 (i.e., by simply rotating the light source 111 and lens 130 which are fixed relative to each other).

[0103] (Appearance) As is clear from the embodiments and modifications described above, the following embodiments are disclosed herein.

[0104] The low-position lighting device (1) of the first embodiment is a low-position lighting device installed at a low position beside a road (2) having one or more lanes (5). The low-position lighting device (1) comprises a first lighting unit (11) and a second lighting unit (12). The first lighting unit (11) illuminates the front-rear side of one or more lanes (5) in the width direction (M2) of the road (2) with first illumination light (C1). The second lighting unit (12) illuminates the front side of one or more lanes (5) in the width direction (M2) of the road (2) with second illumination light (C2).

[0105] With this configuration, the first lighting unit (11) and the second lighting unit (12) illuminate the far side and the near side with separate lighting lights (first lighting light (C1) and second lighting light (C2)). This makes it easier to make the illumination (brightness on the road surface) uniform between the far side and the near side. As a result, it is possible to improve the uniformity of each lane axis and the overall uniformity of multiple lanes 5.

[0106] In the second embodiment of the low-position lighting device (1), in the first embodiment, the second horizontal beam angle (φ2) of the second illumination light (C2) is greater than the first horizontal beam angle (φ1) of the first illumination light (C1).

[0107] With this configuration, the second illumination range (N2) of the second illumination light (C2) can be extended to approximately the same width as the first illumination range (N1) of the first illumination light (C1) in the laying direction (M1). This makes it easier to achieve uniform illumination between the back and front sides.

[0108] In the third embodiment of the low-position lighting device (1), as in the second embodiment, the second illumination light (C2) includes two constituent luminous fluxes (C21, C22). The respective illumination ranges (N21, N22) of the two constituent luminous fluxes (C21, C22) are connected to each other, but are offset from each other in the direction of the road (2) laying direction (M1).

[0109] This configuration allows the second illumination range (N2) of the second illumination light (C2) to be easily extended in the direction (M1) of the road (2). This makes it possible to illuminate the area closer to the road more uniformly.

[0110] In the low-position lighting device (1) of the fourth embodiment, as in the third embodiment, the rear portion (N2d) of the connecting part between the respective illumination ranges (N21, N22) of the two constituent luminous fluxes (C21, C22) is constricted. The front end (N1b) of the first illumination range (N1) of the first illumination light (C1) protrudes into the second illumination range (N2) of the second illumination light (C2) and overlaps with the rear portion (N2d) of the connecting part.

[0111] With this configuration, the front end (N1b) of the first illumination range (N1) extends into the second illumination range (N2), allowing the width (P11) in the laying direction (M1) of the front half of the first illumination range (N1) to be further widened in the laying direction (M1). This allows the rear side to be illuminated more uniformly. In addition, the front end (N1b) of the first illumination range (N1) of the first illumination light (C1) extends into the second illumination range (N2) of the second illumination light (C2), overlapping with the rear portion (i.e., the constricted portion) (N2d) of the connecting portion. Therefore, the overlap between the front end (N1b) of the first illumination range (N1) and the second illumination range (N2) can be reduced. This prevents the illumination from becoming too bright in the overlapping area.

[0112] In the fifth embodiment of the low-position lighting device (1), in any one of the first to fourth embodiments, the first lighting unit (11) and the second lighting unit (12) are arranged side by side in the vertical direction.

[0113] This configuration allows the horizontal illumination direction of both the first illumination light (C1) and the second illumination light (C2) to be the same. As a result, it becomes easier to set the horizontal illumination direction of both the first illumination light (C1) and the second illumination light (C2).

[0114] In the sixth embodiment of the low-position lighting device (1), the second lighting unit (12) is positioned above the first lighting unit (11) in the fifth embodiment.

[0115] This configuration prevents the first illumination light (C1) and the second illumination light (C2) from directly entering the eyes of drivers of vehicles traveling on the road (2). As a result, it is possible to prevent drivers from being dazzled by the illumination light (C1, C2) of the low-position lighting device (1). More specifically, the second lighting unit (12) is positioned above the first lighting unit (11). However, the vertical illumination direction of the second lighting unit (12) is directed downwards compared to the vertical illumination direction of the first lighting unit (11). Therefore, it is possible to prevent the second illumination light (C2) of the second lighting unit (12) from directly entering the eyes of drivers. On the other hand, the vertical illumination direction of the first lighting unit (11) is directed upwards compared to the vertical illumination direction of the second lighting unit (12). However, the first lighting unit (11) is positioned below the second lighting unit (12). Therefore, it is possible to suppress the direct incidence of the first illumination light (C1) from the first lighting unit (11) into the driver's eyes.

[0116] The seventh embodiment of the low-position lighting device (1) is such that in any one of the first to sixth embodiments, at least one of the first lighting unit (11) and the second lighting unit (12) comprises a unit body (100) and a support mechanism (160). The unit body (100) emits a first illumination light (C1) or a second illumination light (C2). The support mechanism (160) fixes the unit body (100) so that its angle around the horizontal axis can be changed.

[0117] With this configuration, the vertical illumination direction of at least one of the first lighting unit (11) and the second lighting unit (12) can be easily changed according to the specifications of the road (2).

[0118] The eighth aspect of the low-position illumination device (1), in the first to seventh aspects, includes, at least one of the first illumination unit (11) and the second illumination unit (12), a light source (111) and a lens (33; 130). The lens (33; 130) is fixed relative to the light source (111) and transmits light from the light source (111) to emit a first illumination light (C1) or a second illumination light (C2).

[0119] In this configuration, since the light source (111) and the lenses (33;130) are relatively fixed, the illumination direction in the vertical direction can be easily changed in the lighting unit equipped with the above-mentioned light source (111) and lenses (33;130). That is, at least one of the first lighting unit (11) and the second lighting unit (12) can easily change the illumination direction in the vertical direction.

[0120] The low-position lighting device (1) of the ninth embodiment, in any one of the first to eighth embodiments, comprises at least one of the first lighting unit (11) and the second lighting unit (12), a light source (61) and a reflector (90). The reflector (90) reflects the light from the light source (61) and emits it as first illumination light (C1) or second illumination light (C2).

[0121] With this configuration, it is possible to efficiently extract reflected light from the reflective surface (91a) through the first emission window (18a) of the housing (10). The light source can be efficiently converted into illumination light (first illumination light (C1) or second illumination light (C2)), further improving the illuminance. In other words, at least one of the first illumination unit (11) and the second illumination unit (12) can efficiently convert light source light into illumination light, further improving the illuminance.

[0122] The tenth embodiment of the low-position lighting device (1) includes a housing (10) that houses a first lighting unit (11) and a second lighting unit (12) in any one of the first to ninth embodiments. The housing (10) has a first emission window (18a) and a second emission window (18b). The first emission window (18a) emits first illumination light (C1). The second emission window (18b) emits second illumination light (C2).

[0123] With this configuration, the first emission window (18a) can prevent the first illumination light (C1) from irradiating areas other than the designated range. In addition, the second emission window (18b) can prevent the second illumination light (C2) from irradiating areas other than the designated range.

[0124] The road lighting method of the low-position lighting device (1) of the eleventh embodiment is a road lighting method using a low-position lighting device that is installed at a low position beside a road (2) having one or more lanes (5) and comprises a first lighting unit (11) and a second lighting unit (12). In the above road lighting method, the first illumination light (C1) of the first lighting unit (11) is directed to the far side of the road (2) in the width direction (M2) of the road (2) among one or more lanes (5), and the second illumination light (C2) of the second lighting unit (12) is directed to the near side of the road (2) in the width direction (M2) among one or more lanes (5).

[0125] With this configuration, the first lighting unit (11) and the second lighting unit (12) illuminate the rear side and the front side with separate illumination lights (first illumination light (C1) and second illumination light (C2)). This makes it easier to make the illumination uniform between the rear side and the front side. As a result, it is possible to improve the uniformity of each lane axis and the overall uniformity of multiple lanes (5). [Explanation of Symbols]

[0126] 1 Low position lighting device 2 road 5, 51-54 lanes 10 cabinets 11. First Lighting Unit 12. Second Lighting Unit 18a First ejection window 18b Second exit window 100 Unit Body 33,130 lenses 40,160 Support mechanism 61,111 light source 90 Reflector C1 1st illumination light C2 2nd illumination light C21,C22 constituent luminous flux M1 installation direction M2 width direction N1b Front end N1 First illumination range N2 Second illumination range N21, N22 illumination range N2d Rear part of the connecting section φ1 First horizontal beam angle φ2 Second horizontal beam angle

Claims

1. A low-position lighting device installed at a low position beside a road with one or more lanes, A first lighting unit that illuminates the far side of one or more lanes in the width direction of the road with first illumination light, The system includes a second lighting unit that illuminates the front side in the width direction of one or more lanes on the road with a second lighting light, The second horizontal beam angle of the second illumination light is greater than the first horizontal beam angle of the first illumination light. The second illumination light comprises two constituent luminous fluxes, The illumination ranges of the two constituent luminous fluxes are connected to each other, but are offset from each other in the direction in which the road is laid. The inner portion of the connecting part of the illumination range of each of the two constituent luminous beams is constricted. The front end of the first illumination range of the first illumination light extends into the second illumination range of the second illumination light and overlaps with the rear portion of the connecting portion. Low-level lighting equipment.

2. The first lighting unit and the second lighting unit are arranged side by side in the vertical direction. The low-position lighting device according to claim 1.

3. The second lighting unit is positioned above the first lighting unit. The low-position lighting device according to claim 2.

4. At least one of the first lighting unit and the second lighting unit is A unit body that emits the first illumination light or the second illumination light, A low-position lighting device according to any one of claims 1 to 3, comprising a support mechanism for fixing the unit body so that its angle around the horizontal axis can be changed.

5. At least one of the first lighting unit and the second lighting unit is Light source and The system includes a lens that is fixed relative to the light source and transmits the light from the light source to emit the first illumination light or the second illumination light. A low-position lighting device according to any one of claims 1 to 3.

6. At least one of the first lighting unit and the second lighting unit is Light source and The system includes a reflecting section that reflects light from the aforementioned light source and emits it as the first illumination light or the second illumination light. A low-position lighting device according to any one of claims 1 to 3.

7. A housing comprising the first lighting unit and the second lighting unit, The aforementioned enclosure is The first emission window that emits the first illumination light, The device has a second emission window that emits the second illumination light, A low-position lighting device according to any one of claims 1 to 3.

8. A road lighting method using a low-position lighting device installed at a low position beside a road having one or more lanes, comprising a first lighting unit and a second lighting unit, The first illumination light of the first lighting unit is projected onto the far side of one or more lanes in the width direction of the road, The second illumination light of the second lighting unit is directed towards the front side in the width direction of the road among one or more lanes. The second horizontal beam angle of the second illumination light is greater than the first horizontal beam angle of the first illumination light. The second illumination light comprises two constituent luminous fluxes, The illumination ranges of the two constituent luminous fluxes are connected to each other, but are offset from each other in the direction in which the road is laid. The inner portion of the connecting part of the illumination range of each of the two constituent luminous beams is constricted. The front end of the first illumination range of the first illumination light extends into the second illumination range of the second illumination light and overlaps with the rear portion of the connecting portion. A road lighting method using low-position lighting devices.

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