Road-lighting device

Abstract

Provided is a road-lighting device comprising a light-emitting module (12) and two or more light distribution adjustment units (14), wherein the two or more light distribution adjustment units (14) are positioned so as not to overlap when viewed from a direction perpendicular to the light-emitting module (12).

Description

road lighting equipment

[0001] The present invention relates to a road lighting device.

[0002] Conventionally, road lighting devices that illuminate road surfaces such as roadways and sidewalks have widely used lamps as light sources, such as fluorescent lamps, high-pressure mercury lamps, metal halide lamps, and sodium lamps. These lamps reflect light from the lamp using a dome-shaped reflector, allowing them to illuminate a wide lighting area such as a road with sufficient brightness.

[0003] Patent Document 1 describes a road lighting device that includes a plurality of LED elements, a sub-lens that focuses diffused light beams from the LED elements in the road width direction and thereby emits a fan-shaped focused light beam that spreads along the road longitudinal direction, and a main lens that is provided below the sub-lens and emits the focused light beam focused by the sub-lens toward the illumination area, and refracts part of the focused light beam along the road longitudinal direction and emits it in the direction of the far end area within the illumination area.

[0004] JP 2009-99492 A

[0005] The inventors have conducted research and found that there is room for improvement in the uniformity and illumination range of road lighting devices. One object of the present invention is to provide a road lighting device that can illuminate a wider range with high uniformity.

[0006] According to the present invention, there is provided the following road lighting device. [1] A road lighting device including a light-emitting module and two or more luminous intensity distribution adjustment units, wherein the two or more luminous intensity distribution adjustment units are positioned so as not to overlap when viewed from a direction perpendicular to the light-emitting module. [2] The road lighting device according to [1], wherein at least one set of the two or more luminous intensity distribution adjustment units are positioned symmetrically in cross section. [3] The road lighting device according to [1], wherein at least one set of the two or more luminous intensity distribution adjustment units is formed by dividing a single cylindrical lens into at least two. [4] The road lighting device according to any of [1] to [3], wherein the luminous intensity distribution adjustment unit has a curved surface, and the angle formed by normals to the curved surface at both ends of the curved surface is 90° or greater. [5] The road lighting device according to any one of [1] to [4], wherein at least one pair of the light distribution adjustment units among the two or more light distribution adjustment units are positioned apart from each other by more than 0 cm and not more than 50 cm. [6] The road lighting device according to any one of [1] to [5], wherein at least one of the light distribution adjustment units has optical characteristics different from the optical characteristics of the other light distribution adjustment units.

[0007] According to the present invention, a road lighting device is provided that can illuminate a wider area with high uniformity.

[0008] 12. An example of a plan view of a road lighting device as seen from below. An A-A' cross-sectional view of FIG. 1. An example of a plan view of a road lighting device as seen from above. An example of a side view of a road lighting device. A perspective view of a light source unit. A perspective view of a light source unit with the luminous intensity distribution adjustment unit not shown. A B-B' cross-sectional view of FIG. 5. A B-B' cross-sectional view of a modified luminous intensity distribution adjustment unit. A diagram showing a first example of a luminous intensity distribution adjustment unit. A C-C' cross-sectional view of FIG. 9. A top view and a side view of a luminous intensity distribution adjustment unit. A diagram showing a second example of a luminous intensity distribution adjustment unit. A C-C' cross-sectional view of FIG. 12. A diagram showing a third example of a luminous intensity distribution adjustment unit. A C-C' cross-sectional view of FIG. 14. A diagram showing modified shapes of a luminous intensity distribution adjustment unit. A first diagram showing modified luminous intensity distribution adjustment units and light source units. A second diagram showing modified luminous intensity distribution adjustment units and light source units. A third diagram showing modified luminous intensity distribution adjustment units and light source units. A fourth diagram showing modified luminous intensity distribution adjustment units and light source units. 21 is a plan view of the light emitting module as viewed from a perpendicular direction. FIG. 22 is a cross-sectional view taken along the line DD' in FIG. 21. FIG. 23 is a diagram showing the light emitting operation of the light emitting module.

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, like components are designated by like reference numerals, and their description will be omitted where appropriate.

[0010] The road lighting device 100 according to this embodiment will be described with reference to the drawings. Fig. 1 is an example of a plan view of the road lighting device 100 according to this embodiment as seen from below. Fig. 2 is a cross-sectional view taken along line A-A' in Fig. 1. Fig. 3 is an example of a plan view of the road lighting device 100 as seen from above. Fig. 4 is an example of a side view of the road lighting device 100.

[0011] As shown in FIG. 1, the road lighting device 100 includes a housing and a light source unit 10 housed within the housing. As shown in FIGS. 1 to 4, the housing has a lower main body case 101 and an upper main body case 102. By combining these, a space a for housing the light source unit 10 is formed inside, as shown in FIG. 2. As shown in FIGS. 3 and 4, the upper main body case 102 further includes a first case portion 102a located on the front side in the direction in which light is emitted, and a second case portion 102b located on the rear side. In FIG. 1, the left side of the road lighting device 100 faces the road. In addition, a pole coupling portion 103 for coupling to a pole is provided on the right side of the road lighting device 100.

[0012] As shown in Figures 1 and 2, a window 104 is provided on the lower surface 101b of the lower main body case 101. This allows light from the light source unit 10 to be irradiated onto the road surface. The window 104 can be made of a light-transmitting material, such as glass or resin. Here, light-transmitting means that the light emitted by the light source unit 10 passes through. A number of grooves 101a for heat dissipation are formed on the side surface of the lower main body case 101. Each component will be described in detail below.

[0013] [Light Source Unit 10] FIG. 5 is a perspective view of the light source unit 10. FIG. 6 is a perspective view of the light source unit 10, with the light distribution adjustment units 14 and 14' omitted. FIG. 7 is a cross-sectional view taken along the line B-B' of FIG. 5. As shown in FIGS. 5 and 6, the light source unit 10 includes a light-emitting module 12, a substantially cylindrical main body 11 that supports the light-emitting module 12, and a light distribution adjustment unit 14 that is detachably attached to the main body 11. The main body 11 also includes a trunk 18, a screw portion (attachment portion) 18a provided at one end of the trunk 18, and a cooling fan 19 provided at the other end of the trunk 18. Note that the cooling fan 19 is usually covered with a cover (not shown) to ensure sufficient airflow from the cooling fan 19.

[0014] 6, the body 18 is substantially cylindrical and has a recessed portion with a width T1 at the center in the longitudinal direction, which is recessed radially inward. The bottom surface of the recessed portion forms a flat surface, and the light-emitting module 12 is mounted (fixed) to this bottom surface.

[0015] The body 18 has an internal space, and as shown in Fig. 7, a heat sink 16 is provided in the internal space. The heat sink 16 has a plurality of fins and is in contact with the phosphor substrate of the light-emitting module 12. Furthermore, a power supply drive circuit and a temperature sensor are provided in the internal space, and the drive circuit controls the drive of a cooling fan 19, thereby controlling the temperature inside the light source unit 10 to be within a desired range.

[0016] The drive circuit includes an LED driver IC, a capacitor, etc., and controls the on-duty (off-duty) of the drive element Q through switching operation using PWM (Pulse Width Modulation) to control the current flowing through the LED chip to a desired value.

[0017] Furthermore, the light distribution adjustment section 14 is detachable from the main body 11 of the light source unit 10. Specific means for configuring the light distribution adjustment section 14 to be detachable include, for example, providing a claw portion (not shown) on the light distribution adjustment section 14 and providing an engagement portion (not shown) made up of a notch, recess, or protrusion on the body 18 of the light source unit 10.

[0018] The body 18 can be made of resin or metal, and the threaded portion 18a is made of, for example, aluminum die-cast.

[0019] A screw hole is provided inside the lower main body case 101 on the side of the support coupling part 103, and by screwing the screw part 18a into the screw hole, the light source unit 10 can be detachably attached to the lower main body case 101, and further, the light emitting module 12 is electrically connected via the screwed screw part 18a. Details of each component of the light source unit 10 will be further described below.

[0020] [Light distribution adjustment unit 14] As shown in Figures 2 and 5, two or more light distribution adjustment units 14 (two, 14 and 14', in Figures 2 and 5) are provided. Each light distribution adjustment unit 14 is attached so as to cover at least a portion of the light-emitting module 12, for example, and has a convex shape extending outward from the light-emitting module 12 side. In other words, the outer surface of the light distribution adjustment unit 14 has a shape that protrudes outward from the light-emitting module 12 side. The relationship between the outer and inner surfaces of the light distribution adjustment unit 14 is arbitrary, but it is preferable that it include a shape that functions as a lens, such as a concave lens or a convex lens. This allows the light emitted from the light-emitting module 12 to be diffused and emitted (irradiated) outward.

[0021] 7, the plurality of luminous intensity distribution adjustment units 14 are positioned so as not to overlap one another when viewed from a direction perpendicular to the light source unit 10 (light-emitting module 12) (when viewed from the right side in FIG. 7). This allows the luminous intensity distribution adjustment units 14 to distribute light over a wider range with high uniformity. The width W1 of the gap between at least one pair of luminous intensity distribution adjustment units 14 is, for example, 5% to 50% of the width W2 of the light source unit 10, or, for example, greater than 0 cm and less than 50 cm.

[0022] At least one set of luminous intensity distribution adjusters 14 may be in contact with each other. In other words, the gap width W1 between at least one set of luminous intensity distribution adjusters 14 may be 0 cm.

[0023] 7, at least one set of luminous intensity distribution adjustment units 14 are preferably positioned symmetrically in cross section. More specifically, at least one set of luminous intensity distribution adjustment units 14 are preferably positioned symmetrically with respect to a plane S that passes through the center of light-emitting module 12 and is perpendicular to light-emitting module 12.

[0024] 8 shows a cross-sectional view taken along the line B-B' of a modified example of the luminous intensity distribution adjustment unit 14. FIG. 8(b) is an enlarged view of the dashed line portion in FIG. 8(a). As shown in FIG. 8, the angle θ between the tangent line l of the end of the luminous intensity distribution adjustment unit 14 and the contact surface may be an angle other than a right angle. The angle θ is preferably, for example, between 60° and 120°.

[0025] As described above, it is preferable that at least a portion of each light distribution adjustment unit 14 that is irradiated with light from the light-emitting module 12 functions as a lens for distributing the light emitted by the light-emitting module 12. In other words, it is preferable that the cross-sectional shape of the light distribution adjustment unit 14 is a part of a lens shape, such as a cylindrical lens shape or a Fresnel lens shape. A cylindrical lens is a lens formed by splitting a cylinder along the axial direction, with one surface having a curvature and the other surface not having a curvature. A Fresnel lens is a lens whose lens surface (the cylindrical lens portion at the end) is processed to reduce its thickness in a concentric manner, etc., and has a structure in which mountain-shaped prisms are formed in a stepped pattern. The mountain-shaped prisms can change the direction of light travel.

[0026] Furthermore, when the light distribution adjustment unit 14 includes a part of the lens shape, it is preferable that the single lens shape be formed when at least one set of light distribution adjustment units 14 are coupled to each other. In other words, it is preferable that at least one set of light distribution adjustment units 14 includes a shape obtained by dividing the single lens shape.

[0027] For example, the light distribution adjustment unit 14 is formed by dividing a single existing lens member such as a cylindrical lens or a Fresnel lens into multiple pieces. Here, the lens member may be divided into multiple light distribution adjustment units 14 by, for example, forming a scribe line on the lens member and then folding the lens member along the scribe line. Alternatively, the lens member may be divided into multiple light distribution adjustment units 14 using an electric cutter, an ultrasonic cutter, or the like.

[0028] Alternatively, an existing lens member may be used as the light distribution adjustment unit 14. For example, two existing convex lenses may be used as the light distribution adjustment units 14, 14', respectively.

[0029] Fig. 9 shows a first example of the light distribution adjustment unit 14. As shown in Fig. 9(a), each light distribution adjustment unit 14 has the shape of a portion of a cylindrical lens on the inner side 14c. Furthermore, as shown in Fig. 9(b), when the light distribution adjustment units 14 shown in Fig. 9(a) are joined together, they form the shape of a single cylindrical lens. In other words, each light distribution adjustment unit 14 has the shape of a single cylindrical lens divided into two. In the first example, the light distribution adjustment units 14, 14' have shapes symmetrical to each other.

[0030] Figure 10(a) shows a CC' cross-sectional view of Figure 9(a), and Figure 10(b) shows a CC' cross-sectional view of Figure 9(b). As shown in Figure 10, in light distribution adjustment unit 14, the surface that receives light emitted from light-emitting module 12 is light-receiving surface 14a, and the surface that emits the received light is emission surface 14b. As an example, the radius of curvature of emission surface 14b can be approximately 42 mm.

[0031] 10, the angle between the normals to the curved surfaces of the luminous intensity distribution adjuster 14 at both ends (θ in FIG. 10(a)) is preferably 90° or greater. This allows the light to be distributed over a wider range.

[0032] Furthermore, as shown in Figure 10, it is preferable that the thickness in the normal direction of the exit surface 14b (convex surface) of the light distribution spectrum adjustment unit 14 is greater at the end a of the exit surface 14b than at the zenith portion b of the exit surface 14b, and that the thickness gradually increases from the zenith portion b of the exit surface 14b to the end a of the exit surface 14b.

[0033] FIG. 11( a) shows a top view of the luminous intensity distribution adjustment unit 14. FIG. 11( b) shows a side view of the luminous intensity distribution adjustment unit 14. The luminous intensity distribution adjustment unit 14 is formed, for example, so that the length T2 of the inner portion 14c including the lens shape is shorter than the length T1 (see FIG. 6) of the main body 11. As an example, the longitudinal length T3 of the luminous intensity distribution adjustment unit 14 can be approximately 192 mm, the length T2 can be approximately 100 mm, the width T5 can be approximately 85 mm, and the width T4 of the end portion of the inner portion 14c can be approximately 17.5 mm. Also, as an example, the height T6 of the luminous intensity distribution adjustment unit 14 can be approximately 21 mm.

[0034] FIG. 12 shows a second example of the light distribution adjustment unit 14. FIG. 13(a) shows a cross-sectional view taken along CC' in FIG. 12(a), and FIG. 13(b) shows a cross-sectional view taken along CC' in FIG. 12(b). As shown in FIGS. 12 and 13, each light distribution adjustment unit 14 has a Fresnel lens shape on the light-receiving surface 14a side of the inner surface 14c. As shown in FIG. 13(b), when the light distribution adjustment units 14 are joined together, the light-receiving surface 14a side has a Fresnel lens shape. In other words, in the second example, each light distribution adjustment unit 14 has a shape in which a Fresnel lens-shaped lens is divided into two on the light-receiving surface 14a side.

[0035] FIG. 14 shows a third example of the light distribution adjustment unit 14. FIG. 15(a) shows a CC' cross-sectional view of FIG. 14(a), and FIG. 15(b) shows a CC' cross-sectional view of FIG. 14(b). As shown in FIGS. 14 and 15, each light distribution adjustment unit 14 has a Fresnel lens shape on the exit surface 14b side of the inner side 14c. As shown in FIG. 15(b), when the light distribution adjustment units 14 are joined together, the exit surface 14b side has a Fresnel lens shape. In other words, in the third example, each light distribution adjustment unit 14 has a shape obtained by dividing a lens having a Fresnel lens shape into two on the exit surface 14b side.

[0036] In the above examples of luminous intensity distribution adjustment unit 14, all of them have a shape in which a single lens is divided into two pieces, but luminous intensity distribution adjustment unit 14 is not limited to this. As shown in Fig. 16 , luminous intensity distribution adjustment unit 14 may be formed by dividing a single lens into three pieces in a cross-sectional view and then removing the central portion (14d in Fig. 16 ) including zenith portion b.

[0037] A coating layer may be provided on the surface of the exit surface of the light distribution adjuster 14. Examples of the coating layer include a hard coating layer, an anti-reflection layer, and an anti-fouling layer, and the coating layer may be a single layer or a laminate of two or more layers.

[0038] The light distribution adjustment unit 14 receives light emitted from the light-emitting module 12 and emits the received light to the outside. Therefore, a material transparent to the emission wavelength of the light-emitting diode elements (LEDs, etc.) can be used as the material for the light distribution adjustment unit 14. Specifically, a thermoplastic resin, a thermosetting resin, glass, etc. can be used, and it is preferable that the material has high heat resistance so as to withstand the temperature rise inside the light source unit 10 due to heat generation by the light-emitting diode elements. More specifically, polyimide, polyacrylate, polysulfone, polyarylsulfone, aromatic polyamide, aromatic polyetheramide, polyphenylene sulfide, polyaryl ether ketone, polyamideimide, liquid crystalline polyester, polytetrafluoroethylene, polycarbonate, etc. can be used.

[0039] Furthermore, when luminous intensity distribution adjustment unit 14 is made of resin, luminous intensity distribution adjustment unit 14 can be manufactured by injection molding, compression molding, transfer molding, cast molding, etc. Alternatively, luminous intensity distribution adjustment unit 14 can be manufactured by forming scribe lines on a lens member manufactured by the above-described method, and then bending the lens member along the scribe lines, or by dividing the lens member by processing using an electric cutter or an ultrasonic cutter.

[0040] The light distribution of the light emitted by the light source unit 10 is what is called a Lambertian light distribution, and when the angle formed with the z direction (see FIG. 7) is θ, the luminous intensity distribution is proportional to cos θ. In other words, in the cross-sectional view shown in FIG. 7, light is basically not distributed to the left of the light-emitting module 12.

[0041] 17 to 20, modifications of the light distribution adjustment sections 14 and the light source units 10 will be described. In the modifications, the light distribution adjustment sections 14 are positioned asymmetrically with respect to the light-emitting modules 12.

[0042] As shown in Fig. 17(a), for example, the angle formed by the tangent line of the end of one luminous intensity distribution adjustment unit 14 and the contact surface may be different from the angle formed by the tangent line of the end of the other luminous intensity distribution adjustment unit 14 and the contact surface (see Fig. 8). Alternatively, as shown in Fig. 17(b), the shapes of the respective luminous intensity distribution adjustment units 14 may be different. In other words, one luminous intensity distribution adjustment unit 14 may have optical characteristics different from the optical characteristics of the other luminous intensity distribution adjustment unit 14. For example, the luminous intensity distribution adjustment unit 14 may be formed by dividing a single meniscus lens into two equal parts at a location offset from the center, rather than by dividing it into two equal parts at the center.

[0043] 18( a), the light-emitting modules 12 may be tilted about the x-direction as an axis. The tilt angle θ is, for example, 1° or more and 30° or less. Also, as shown in FIG. 18( b), the light-emitting modules 12 may be disposed at positions shifted from the center. This also makes the light distribution adjustment units 14 asymmetrical with respect to the light-emitting modules 12.

[0044] 19, which is a cross-sectional view of the light source unit 10 viewed from the y direction, the light-emitting modules 12 may be tilted around the y direction at an angle of, for example, 1° to 30°. The light-emitting modules 12 may also be tilted around the y direction in addition to the tilt around the x direction. This can improve the uniformity not only in the vehicle travel direction but also in the lane width direction.

[0045] 20, a plurality of light-emitting modules 12 may be provided. For example, as shown in Fig. 20(a), the light-emitting modules 12 may be arranged along the short side of the light source unit 10, or as shown in Fig. 20(b), the light-emitting modules 12 may be arranged along the long side of the light source unit 10.

[0046] [Light-emitting module 12] The light-emitting module 12 is not particularly limited as long as it can emit light, and a fluorescent lamp, a high-pressure mercury lamp, a metal halide lamp, a sodium lamp, or the like can be used, but it is preferable that the light-emitting module 12 is configured from a phosphor substrate 20 and a plurality of light-emitting elements (LED chips) 30 mounted on the phosphor substrate 20. In the following explanation, the light-emitting module 12 will be described as being configured from a phosphor substrate 20 and a plurality of light-emitting elements (LED chips) 30 mounted on the phosphor substrate 20.

[0047] Fig. 21 is a plan view of the light-emitting module 12 as viewed from a perpendicular direction, and Fig. 22 is a cross-sectional view taken along the line DD' in Fig. 21. As shown in Fig. 21, the light-emitting module 12 has a plurality of light-emitting elements 30 arranged in a lattice pattern on a phosphor substrate 20. However, the arrangement of the light-emitting elements 30 is not limited to a lattice pattern.

[0048] [Phosphor Substrate 20] A plurality of light-emitting elements 30 are arranged on the phosphor substrate 20. The phosphor substrate 20 serves to hold these elements. As shown in FIG. 22 , the phosphor substrate 20 includes a phosphor layer 21, a circuit pattern layer 22, an insulating layer 23, and a back pattern layer 24. These layers are stacked in this order starting from the side on which the light-emitting elements 30 are provided. The phosphor layer 21 is made of a phosphor material and serves to emit light using light emitted by the light-emitting elements 30 as excitation light. The circuit pattern layer 22 and the back pattern layer 24 are provided to supply power to the light-emitting elements 30. The insulating layer 23 is made of an insulating material and supports the above-mentioned components while preventing the circuit pattern layers 22 and the back pattern layers 24 from shorting out with each other.

[0049] <Phosphor Layer 21> The phosphor layer 21 is formed so as to cover the circuit pattern layer 22. The phosphor layer 21 is formed, for example, in at least a part of the area of ​​the circuit pattern layer 22 excluding the area where the light emitting elements 30 are arranged. In other words, the phosphor layer 21 is formed in the area surrounding the area where the light emitting elements 30 are arranged in the circuit pattern layer 22. It is preferable that the phosphor layer 21 is formed in most of the above-mentioned area.

[0050] The phosphor layer 21 is, for example, composed of a phosphor and a binder, which will be described later. The phosphor contained in the phosphor layer 21 is fine particles dispersed and held in the binder, and has the property of exciting the light emitted from the light-emitting element 30 using the light as excitation light. The binder may be, for example, an epoxy-based, acrylate-based, or silicone-based binder, as long as it has insulating properties equivalent to those of the binder contained in the solder resist.

[0051] The phosphor contained in the phosphor layer 21 of this embodiment may be, for example, one or a combination of two or more selected from an α-type sialon phosphor containing Eu, a β-type sialon phosphor containing Eu, a CASN phosphor containing Eu, and a SCASN phosphor containing Eu. In addition to these, phosphors such as YAG, LuAG, BOS, and other visible light-excited phosphors may also be included.

[0052] The α-sialon phosphor containing Eu has the general formula: M ｘ EU ｙ Si １２－（ｍ＋ｎ） Al （ｍ＋ｎ） O ｎ N １６－ｎ In the above general formula, M is one or more elements selected from the group consisting of Li, Mg, Ca, Y, and lanthanide elements (excluding La and Ce), including at least Ca, and when the valence of M is a, ax+2y=m, where x is 0<x≦1.5, 0.3≦m<4.5, and 0<n<2.25.

[0053] The β-type sialon phosphor containing Eu has the general formula: Si ６－ｚ Al ｚ O ｚ N ８－ｚ (z=0.005 to 1) and divalent europium (Eu ２＋ ) is a solid solution phosphor.

[0054] Furthermore, examples of nitride phosphors include Eu-containing CASN phosphors and Eu-containing SCASN phosphors.

[0055] A CASN phosphor containing Eu (an example of a nitride phosphor) is, for example, represented by the formula CaAlSiN３ :Eu ２＋ and Eu ２＋ The term "CASN phosphor" refers to a red phosphor that uses as an activator an alkaline earth silicon nitride crystal as a matrix. Note that the definition of a CASN phosphor containing Eu in this specification excludes a SCASN phosphor containing Eu.

[0056] A SCASN phosphor containing Eu (an example of a nitride phosphor) is, for example, represented by the formula (Sr, Ca)AlSiN ３ :Eu ２＋ and Eu ２＋ This refers to a red phosphor that uses as an activator an alkaline earth silicon nitride crystal as a matrix.

[0057] <Circuit Pattern Layer 22, Back Pattern Layer 24> The circuit pattern layer 22 according to this embodiment is a conductive layer formed on the front side of the insulating layer 23, and the back pattern layer 24 is a conductive layer provided on the back side of the insulating layer 23. The materials constituting the circuit pattern layer 22 and the back pattern layer 24 are not particularly limited as long as they are conductive, and are, for example, copper.

[0058] The area on the surface of the insulating layer 23 where the circuit pattern layer 22 is arranged is, for example, 60% or more of the area of ​​the surface of the insulating layer 23 .

[0059] <Insulating Layer 23> The insulating layer 23 according to this embodiment maintains each component and also plays a role in preventing short circuits between the circuit pattern layers 22 and the back surface pattern layers 24. The material constituting the insulating layer 23 is not particularly limited as long as it has insulating properties, but for example, an insulating material such as a prepreg obtained by impregnating a fiber substrate such as glass cloth with a resin such as bismaleimide resin can be used.

[0060] [Light-emitting element 30] The light-emitting element 30 includes general light-emitting elements such as fluorescent lamps and LEDs, but a CSP (chip scale package) incorporating a flip-chip LED 32 (hereinafter referred to as LED 32) is particularly preferred (see FIG. 22). As shown in FIG. 22, the CSP is preferably such that the entire periphery (five sides) of the LED 32, excluding the bottom surface, is covered with a phosphor encapsulating layer 31 containing a phosphor. When covered with the phosphor encapsulating layer 31, the light from the LED 32 is color-converted by the phosphor of the phosphor encapsulating layer 31 and irradiated to the outside.

[0061] [Light Emitting Operation of Light Emitting Module 12] Next, the light emitting operation of the light emitting module 12 of this embodiment will be described with reference to FIG.

[0062] First, when an activation switch (not shown) that activates the plurality of light-emitting elements 30 is turned on, power supply from an external power source (not shown) to the circuit pattern layer 22 begins via a connector (not shown), and the plurality of light-emitting elements 30 emit light L radially, and part of the light L reaches the phosphor layer 21 of the phosphor substrate 20. Below, the behavior of the emitted light L will be explained according to the traveling direction of the light L.

[0063] A portion of the light L emitted from each light-emitting element 30 is emitted to the outside without entering the phosphor layer 21. In this case, the wavelength of the light L remains the same as the wavelength of the light L when it is emitted from each light-emitting element 30.

[0064] Furthermore, a portion of the light L emitted from the light-emitting element 30 is incident on the phosphor layer 21. Here, the "portion of light L" includes light that has not been color-converted by the phosphor of the light-emitting element 30 (phosphor sealing layer 31), i.e., light from the LED 32 itself (e.g., blue light (wavelength of approximately 470 nm)). When a portion of the light L emitted from the light-emitting element 30 collides with the phosphor dispersed in the phosphor layer 21, the phosphor is excited and emits light. As a result, a portion of the energy of the light L is used to excite the phosphor, resulting in a loss of some of the energy of the light L. As a result, the wavelength of the light L is converted (wavelength conversion is performed). For example, depending on the type of phosphor in the phosphor layer 21 (e.g., when red-based CASN is used as the phosphor), the wavelength of the light L becomes longer (e.g., 650 nm). Furthermore, while some of the light emitted by the excitation of the phosphor layer 21 exits the phosphor layer 21 as is, a portion of the light travels toward the underlying circuit pattern layer 22. A portion of the light is reflected by the circuit pattern layer 22 and emitted to the outside. As described above, when the wavelength of light emitted by the excitation of the phosphor in the phosphor layer 21 is 600 nm or longer, a reflective effect can be achieved even if the circuit pattern layer 22 is made of Cu. Note that the wavelength of the light L may differ from the above example depending on the type of phosphor in the phosphor layer 21, but in either case, wavelength conversion of the light L is achieved. For example, when the wavelength of light emitted by the excitation of the phosphor layer 21 is less than 600 nm, a reflective effect can be achieved by plating the circuit pattern layer 22 or its surface with Ag (plated). Alternatively, a similar effect can be achieved by providing a white reflective layer below the phosphor layer 21 (on the insulating layer 23 side). The reflective layer can be formed, for example, from a white paint such as titanium oxide filler.

[0065] Through the above operation, light emitted from the light-emitting module 12 passes through the light distribution adjustment unit 14 and is irradiated from the road lighting device 100. The road lighting device 100 according to this embodiment has the following advantages. First, by having multiple light distribution adjustment units 14, it is possible to illuminate a wide area. Furthermore, since the light distribution adjustment units 14 can be arranged asymmetrically, it is possible to design the device according to the site.

[0066] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0067] This application claims priority based on Japanese Patent Application No. 2023-205208, filed December 5, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0068] REFERENCE SIGNS LIST 100 Road lighting device 101 Lower main body case 101a Groove 102 Upper main body case 102a First case part 102b Second case part 103 Pillar joint part 104 Window part 10 Light source unit 11 Main body 12 Light-emitting module 14 Light distribution adjustment part 14a Light receiving surface 14b Emission surface 16 Heat sink 18 Body part 18a Screw part 19 Cooling fan 20 Phosphor substrate 21 Phosphor layer 22 Circuit pattern layer 23 Insulation layer 24 Back surface pattern layer 30 Light-emitting element 32 LED

Claims

1. A road lighting device comprising a light emitting module and two or more light distribution adjustment units, wherein the two or more light distribution adjustment units are positioned so as not to overlap when viewed from a direction perpendicular to the light emitting module.

2. The road lighting device according to claim 1, wherein at least one set of said light distribution adjustment parts among said two or more light distribution adjustment parts are positioned symmetrically in cross section.

3. The road lighting device according to claim 1, wherein at least one of the two or more light distribution adjustment sections is formed by dividing one cylindrical lens into at least two.

4. A road lighting device according to any one of claims 1 to 3, wherein the light distribution adjustment portion has a curved surface, and an angle between normals to the curved surface at both ends of the curved surface is 90° or more.

5. The road lighting device according to any one of claims 1 to 3, wherein at least one pair of said light distribution adjustment parts among said two or more light distribution adjustment parts are positioned apart from each other by more than 0 cm and not more than 50 cm.

6. A road lighting device according to any one of claims 1 to 3, wherein at least one of the light distribution adjustment sections has optical characteristics different from the optical characteristics of the other light distribution adjustment sections.

Images