Road lighting device

Abstract

To provide a road lighting device capable of illuminating a wider range with high uniformity.SOLUTION: A road lighting device comprises a light emitting module 12, and two or more light distribution adjustment units 14. 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.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to road lighting.

[0002] Conventionally, in road lighting devices for illuminating the road surfaces of roads such as roadways and sidewalks, lamps such as fluorescent lamps, high-pressure mercury lamps, metal halide lamps, and sodium lamps have been widely used as light sources. These lamps can reflect the light from the lamp with a dome-shaped reflector and illuminate a wide lighting area such as a road with sufficient brightness.

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

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As a result of investigations by the present inventor, it has been found that there is room for improvement in terms of uniformity and lighting range for road lighting. An example of the object of the present invention is to provide road lighting that can illuminate a wider range with high uniformity.

Means for Solving the Problems

[0006] According to the present invention, the following road lighting is provided. [1] A road lighting device comprising a light-emitting module and two or more light distribution adjustment units, wherein when viewed from a direction perpendicular to the light-emitting module, the two or more light distribution adjustment units are positioned so as not to overlap. [2] Among the two or more light distribution adjustment units, at least one set of the light distribution adjustment units is symmetrically positioned in cross-section. The road lighting according to [1]. [3] Among the two or more light distribution adjustment units, at least one set of the light distribution adjustment units is formed by dividing at least two of one cylindrical lens. The road lighting according to [1]. [4] The light distribution adjustment unit has a curved surface, and the angle formed by the normal lines of the curved surface at both ends of the curved surface is 90° or more. The road lighting according to any one of [1] to [3]. [5] Among the two or more light distribution adjustment units, at least one set of the light distribution adjustment units is positioned at a distance greater than 0 cm and less than or equal to 50 cm from each other. The road lighting according to any one of [1] to [4]. [6] At least one of the light distribution adjustment units has an optical property different from that of the other light distribution adjustment units. The road lighting according to any one of [1] to [5].

Advantages of the Invention

[0007] According to the present invention, there is provided a road lighting that can illuminate a wider range with a high degree of uniformity.

Brief Description of the Drawings

[0008]

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[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as 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 viewed from below. FIG. 2 is a cross-sectional view taken along line A-A' of FIG. 1. FIG. 3 is an example of a plan view of the road lighting device 100 as viewed 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 in 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 coupling these, as shown in FIG. 2, a space a for housing the light source unit 10 is formed inside. As shown in FIGS. 3 and 4, the upper main body case 102 further has a first case portion 102a located on the front side and a second case portion 102b located on the rear side in the direction in which light is radiated. In FIG. 1, the left side of the road lighting device 100 faces the road side. Further, on the right side of the road lighting device 100, a column coupling portion 103 for coupling with a column is provided.

[0012] As shown in FIGS. 1 and 2, a window portion 104 is provided on the lower surface 101b of the lower main body case 101. Thereby, the light from the light source unit 10 can be irradiated onto the road surface. The window portion 104 can be made of a light-transmissive material, such as glass or resin. Here, light transmissivity means transmitting the light emitted by the light source unit 10. A large number of heat dissipation grooves 101a are formed on the side surface of the lower main body case 101. Hereinafter, the details of each configuration will be described.

[0013] [Light Source Unit 10] FIG. 5 is a perspective view of the light source unit 10. Further, FIG. 6 is a perspective view of the light source unit 10 with the description of the light distribution adjusting parts 14, 14' omitted. Further, FIG. 7 is a cross-sectional view taken along 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 adjusting part 14 detachably provided on the main body 11. Further, the main body 11 includes a body part 18, a screw part (attachment part) 18a provided at one end of the body part 18, and a cooling fan 19 provided at the other end of the body part 18. Note that, in order to ensure the air volume (air passage) from the cooling fan 19, the cooling fan 19 is usually covered with a cover (not shown).

[0014] As shown in FIG. 6, the body part 18 is substantially cylindrical and has a portion recessed radially inward with a width T1 at the central portion in the longitudinal direction. The bottom surface of the recessed portion constitutes a flat surface, and the light emitting module 12 is mounted (fixed) on this bottom surface.

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

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

[0017] Further, the light distribution adjusting part 14 is detachable from the main body 11 of the light source unit 10. As a specific means for configuring the light distribution adjusting part 14 to be detachable, for example, the light distribution adjusting part 14 is provided with claw parts (not shown), and the body part 18 of the light source unit 10 is provided with an engaging part (not shown) composed of a notch, a recess, or a protrusion.

[0018] The body 18 can be made of resin or metal. Further, the threaded portion 18a is formed by, for example, aluminum die casting.

[0019] Inside the lower main body case 101, a threaded hole is provided on the side of the support column coupling portion 103. By screwing the threaded portion 18a into the threaded hole, the light source unit 10 can be detachably attached to the lower main body case 101. Further, the light emitting module 12 is electrically connected via the screwed threaded portion 18a. Hereinafter, the details of each component of the light source unit 10 will be further described.

[0020] [Light distribution adjustment unit 14] As shown in FIGS. 2 and 5, two or more (two in FIGS. 2 and 5, 14 and 14') light distribution adjustment units 14 are provided. Each light distribution adjustment unit 14 is mounted so as to cover at least a part of the light emitting module 12, and has a convex shape outward from the side of the light emitting module 12. That is, the outer surface of the light distribution adjustment unit 14 has a shape that protrudes outward from the side of the light emitting module 12. The relationship between the outer surface and the inner surface of the light distribution adjustment unit 14 is arbitrary, but preferably includes a shape that functions as a lens, such as a concave lens or a convex lens. By doing so, the light emitted from the light emitting module 12 can be diffused and emitted (irradiated) outward.

[0021] Further, as shown in FIG. 7, when the plurality of light distribution adjustment units 14 are viewed from a direction perpendicular to the light source unit 10 (the light emitting module 12) (when viewed from the right side in FIG. 7), they are positioned so as not to overlap each other. Thereby, the light distribution adjustment unit 14 can distribute light over a wider range with a high degree of uniformity. Note that the width W1 of the gap between at least one set of the light distribution adjustment units 14 is, for example, 5% or more and 50% or less of the width W2 of the light source unit 10, or, for example, more than 0 cm and 50 cm or less.

[0022] Also, at least one set of light distribution adjusting parts 14 may be in contact. In other words, the width W1 of the gap between at least one set of light distribution adjusting parts 14 may be 0 cm.

[0023] Also, as shown in FIG. 7, at least one set of light distribution adjusting parts 14 is preferably symmetrically positioned in the cross-section. More specifically, it is preferably symmetrically positioned with respect to a plane S that passes through the center of the light emitting module 12 and is perpendicular to the light emitting module 12, between at least one set of light distribution adjusting parts 14.

[0024] Also, FIG. 8 shows a cross-sectional view of a modified example of the light distribution adjusting part 14 taken along the line B - B'. FIG. 8(b) is an enlarged view of the dashed line part in FIG. 8(a). As shown in FIG. 8, the angle θ formed by the tangent line l at the end of the light distribution adjusting part 14 with the contact surface may be an angle other than a right angle. The angle θ is preferably, for example, 60° or more and 120° or less.

[0025] Also, as described above, at least a part of the portion of each light distribution adjusting part 14 that is irradiated with light from the light emitting module 12 preferably functions as a lens for distributing the light emitted by the light emitting module 12. In other words, the cross-sectional shape of the orientation distribution adjusting part 14 is preferably a part of a lens shape such as the shape of a cylindrical lens and the shape of a Fresnel lens. Note that a cylindrical lens is a lens formed by cutting a cylinder in the axial direction, consisting of one surface with curvature and the other surface without curvature. Also, a Fresnel lens is a lens in which the lens surface (the cylindrical lens part at the end) is processed so that the thickness decreases in a concentric circle shape or the like, and has a structure in which prism-shaped ridges are formed in a stepped manner. The prism-shaped ridges can change the traveling direction of light.

[0026] Further, when the light distribution adjustment part 14 includes a part of the shape of the lens shape, it is preferable that when at least one set of light distribution adjustment parts 14 are coupled to each other, they form one of the lens shapes. In other words, it is preferable that at least one set of light distribution adjustment parts 14 includes a shape obtained by dividing one of the lens shapes.

[0027] For example, the light distribution adjustment part 14 is formed by dividing a single existing lens member such as a cylindrical lens or a Fresnel lens into a plurality of parts. Here, the lens member may be divided into a plurality of light distribution adjustment parts 14, for example, by being folded along the scribe line after the scribe line is formed. Further, the lens member may be divided into a plurality of light distribution adjustment parts 14 using an electric cutter or an ultrasonic cutter.

[0028] Alternatively, an existing lens member may be used as the light distribution adjustment part 14. For example, two existing convex lenses may be used as the light distribution adjustment parts 14 and 14´, respectively.

[0029] FIG. 9 shows a first example of the light distribution adjustment part 14. As shown in FIG. 9(a), each light distribution adjustment part 14 has a part of the shape of a cylindrical lens on the inner side 14c. Further, as shown in FIG. 9(b), when the light distribution adjustment parts 14 shown in FIG. 9(a) are joined to each other, they form the shape of a single cylindrical lens. In other words, each light distribution adjustment part 14 has a shape obtained by dividing a single cylindrical lens into two parts. In the first example, the light distribution adjustment parts 14 and 14´ have symmetrical shapes with respect to each other.

[0030] FIG. 10(a) shows a cross-sectional view taken along line C-C´ of FIG. 9(a), and FIG. 10(b) shows a cross-sectional view taken along line C-C´ of FIG. 9(b). As shown in FIG. 10, in the light distribution adjustment part 14, the surface that receives the light emitted from the light emitting module 12 is defined as the light receiving surface 14a, and the surface that emits the received light is defined as the light emitting surface 14b. As an example, the radius of curvature of the light emitting surface 14b can be about 42 mm.

[0031] In addition, for the curved surface of the light distribution adjustment unit 14 shown in FIG. 10, it is preferable that the angle (θ in FIG. 10(a)) formed by the normal lines of the curved surfaces at both ends is 90° or more. Thereby, light can be distributed over a wider range.

[0032] Also, as shown in FIG. 10, the thickness in the normal direction of the light emitting surface 14b (convex curved surface) of the light distribution and spectral adjustment unit 14 is larger at the end a of the light emitting surface 14b than at the zenith b of the light emitting surface 14b. Furthermore, it is preferable that the value of the thickness gradually increases from the zenith b to the end a of the light emitting surface 14b.

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

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

[0035] FIG. 14 shows a third example of the light distribution adjustment unit 14. FIG. 15(a) shows a cross-sectional view taken along the line C-C' of FIG. 14(a), and FIG. 15(b) shows a cross-sectional view taken along the line C-C' of FIG. 14(b). As shown in FIGS. 14 and 15, each light distribution adjustment unit 14 has a Fresnel lens shape on the emission surface 14b side of the inner side 14c. Further, as shown in FIG. 15(b), when the respective light distribution adjustment units 14 are joined to each other, the emission surface 14b side has a Fresnel lens shape. In other words, in the third example, each light distribution adjustment unit 14 has a shape in which a lens having a Fresnel lens shape on the emission surface 14b side is divided into two.

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

[0037] Further, a coating layer may be provided on the surface of the emission surface of the light distribution adjustment unit 14. Examples of the coating layer include a hard coat layer, an antireflection layer, an antifouling layer, etc., and it can be a single layer or a laminate of two or more layers.

[0038] Since the light distribution adjustment unit 14 receives the emitted light of the light emitting module 12 and emits the received light to the outside, as a material constituting the light distribution adjustment unit 14, a material transparent to the emission wavelength of a light emitting diode element (such as an LED) can be used. Specifically, a thermoplastic resin, a thermosetting resin, glass, etc. can be used, and it is preferably highly heat-resistant so as to withstand the temperature rise inside the light source unit 10 due to the heat generation of the light emitting diode element. More specifically, polyimide, polyacrylate, polysulfone, polyallyl sulfone, aromatic polyamide, aromatic polyether amide, polyphenylene sulfide, polyallyl ether ketone, polyamideimide, liquid crystal polyester, polytetrafluoroethylene, polycarbonate, etc. can be used.

[0039] When the light distribution adjustment part 14 is made of resin, the light distribution adjustment part 14 can be manufactured by injection molding, compression molding, transfer molding, casting molding, or the like. Alternatively, the light distribution adjustment part 14 can also be manufactured by folding the lens member manufactured by the above method along the scribe line after the scribe line is formed, or by dividing it 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 a so-called Lambertian distribution. When the angle formed with the z direction (see FIG. 7) is θ, the luminous intensity distribution is proportional to cosθ. In other words, basically no light is distributed to the left side of the light emitting module 12 in the cross-sectional view shown in FIG. 7.

[0041] Next, with reference to FIGS. 17 to 20, modified examples of the light distribution adjustment part 14 and the light source unit 10 will be described. In the modified examples, each light distribution adjustment part 14 is positioned asymmetrically with respect to the light emitting module 12.

[0042] As shown in FIG. 17(a), for example, the angle formed by the tangent line at the end of one light distribution adjustment part 14 with the contact surface and the angle formed by the tangent line at the end of the other light distribution adjustment part 14 with the contact surface (see FIG. 8) may be different. Or, as shown in FIG. 17(b), the shapes of the respective light distribution adjustment parts 14 may be different. In other words, one light distribution adjustment part 14 may have optical characteristics different from those of the other light distribution adjustment part 14. For example, the light distribution adjustment part 14 may be formed by dividing it into two at a position shifted from the center instead of equally dividing a single meniscus lens into two at the center.

[0043] Also, as shown in FIG. 18(a), the light emitting module 12 may be inclined about the x axis. The inclination angle θ is, for example, 1° or more and 30° or less. Further, as shown in FIG. 18(b), the light emitting module 12 may be arranged at a position shifted from the center. Also by this, each light distribution adjustment part 14 becomes asymmetric with respect to the light emitting module 12.

[0044] Also, as shown in FIG. 19 which is a cross-sectional view of the light source unit 10 viewed from the y-direction, the light emitting module 12 may be inclined at an angle of, for example, 1° or more and 30° or less about the y-axis. Further, the light emitting module 12 may be inclined about the y-axis in combination with the inclination about the x-axis. Thereby, it is possible to improve not only the uniformity in the vehicle traveling direction but also the uniformity in the lane width direction.

[0045] Also, as shown in FIG. 20, a plurality of light emitting modules 12 may be provided. For example, as shown in FIG. 20(a), they may be arranged along the short side direction of the light source unit 10, or as shown in FIG. 20(b), they may be arranged along the long side direction 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, etc. can be used, but it is preferably composed of a phosphor substrate 20 and a plurality of light emitting elements (LED chips) 30 mounted on the phosphor substrate 20. In the following description, the light emitting module 12 will be described as being composed of 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 viewed from a right angle direction, and FIG. 22 is a cross-sectional view taken along D-D' in FIG. 21. As shown in FIG. 21, in the light emitting module 12, a plurality of light emitting elements 30 are arranged in a lattice pattern on the phosphor substrate 20. However, the arrangement of the light emitting elements 30 is not limited to the 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. Further, 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 surface pattern layer 24. These layers are laminated in this order from the surface side where the light-emitting element 30 is provided. The phosphor layer 21 is composed of a phosphor material and serves to emit light using the light emitted by the light-emitting element 30 as excitation light. Also, the circuit pattern layer 22 and the back surface pattern layer 24 are provided to supply power to the light-emitting element 30. Further, the insulating layer 23 is composed of an insulating material, holds the above-described components, and prevents the circuit pattern layer 22 and the back surface pattern layer 24 from short-circuiting 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, on at least a part of the region excluding the region where the light-emitting element 30 of the circuit pattern layer 22 is arranged. In other words, the phosphor layer 21 is formed in the region around the region where the light-emitting element 30 of the circuit pattern layer 22 is arranged. The phosphor layer 21 is preferably formed in most of the above-described regions.

[0050] As an example, the phosphor layer 21 is composed of a phosphor and a binder, which will be described later. The phosphor contained in the phosphor layer 21 is fine particles held in a state of being dispersed in the binder and has the property of being excited by the light emitted by the light-emitting element 30 as excitation light. The binder may be, for example, an epoxy-based, acrylate-based, silicone-based, etc., as long as it has the same insulation property as the binder contained in the solder resist.

[0051] As an example of the phosphor contained in the phosphor layer 21 of the present embodiment, 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 can be used. In addition to this, phosphors such as YAG, LuAG, BOS, and other visible light-excited phosphors may also be included.

[0052] The α - sialon phosphor containing Eu is represented by 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 at least one element selected from the group consisting of Li, Mg, Ca, Y, and lanthanide elements (excluding La and Ce), and containing at least Ca. When the valence of M is a, ax + 2y = m, where 0 < x ≤ 1.5, 0.3 ≤ m < 4.5, and 0 < n < 2.25.

[0053] The β - sialon phosphor containing Eu is a phosphor in which divalent europium (Eu 6-z Al z O z N 8-z (z = 0.005 - 1)) is dissolved as a luminescence center in β - sialon represented by the formula. 2+ )

[0054] In addition, as nitride phosphors, there are mentioned a CASN phosphor containing Eu, a SCASN phosphor containing Eu, and the like.

[0055] The CASN phosphor containing Eu (an example of a nitride phosphor) is represented by, for example, the formula CaAlSiN3:Eu 2+ and is a red phosphor having Eu 2+ as an activator and a crystal composed of alkaline earth silicon nitride as a matrix. In the definition of the CASN phosphor containing Eu in this specification, the SCASN phosphor containing Eu is excluded.

[0056] The SCASN phosphor containing Eu (an example of a nitride phosphor) is represented by, for example, the formula (Sr,Ca)AlSiN3:Eu 2+ and is a red phosphor having Eu 2+ as an activator and a crystal composed of alkaline earth silicon nitride as a matrix.

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

[0058] Note that the region on the surface of the insulating layer 23 where the circuit pattern layer 22 is disposed is, for example, 60% or more of the region (area) of the surface of the insulating layer 23.

[0059] <Insulating layer 23> The insulating layer 23 according to this embodiment holds each component and plays a role of 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, and for example, an insulating material such as a prepreg obtained by impregnating a resin such as a bismaleimide resin into a fiber base material such as a glass cloth can be used.

[0060] [Light emitting element 30] The light emitting element 30 includes general light emitting elements such as fluorescent lamps and LEDs, and a CSP (Chip Scale Package) incorporating a flip chip LED 32 (hereinafter referred to as LED 32) is particularly preferable (see FIG. 22). As the CSP, as shown in FIG. 22, it is preferable that the entire circumference (five surfaces) excluding the bottom surface of the LED 32 is covered with a phosphor encapsulation layer 31 containing a phosphor. When covered with the phosphor encapsulation layer 31, the light of the LED 32 is color - converted by the phosphor in the phosphor encapsulation layer 31 and irradiated to the outside.

[0061] [Light emission operation of the light emitting module 12] Next, the light emission operation of the light emitting module 12 of this embodiment will be described with reference to FIG. 23.

[0062] First, when an operation switch (not shown) for operating a plurality of light-emitting elements 30 is turned on, power supply from an external power source (not shown) to the circuit pattern layer 22 is started via a connector (not shown), and the plurality of light-emitting elements 30 emit light L radially. A part of the light L reaches the phosphor layer 21 of the phosphor substrate 20. Hereinafter, the behavior of the light L will be described by dividing it in the traveling direction of the emitted light L.

[0063] A part 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] Also, a part of the light L emitted from the light-emitting element 30 enters the phosphor layer 21. Here, the "part of the light L" includes the light that has not been color-converted by the phosphor (phosphor encapsulation layer 31) of the light-emitting element 30, that is, the light of the LED 32 itself (for example, light of blue color (wavelength near 470 nm)). When a part 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. Along with this, a part of the energy of the light L is used for the excitation of the phosphor, so a part of the energy of the light L is lost. 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 (for example, when red CASN is used for the phosphor), the wavelength of the light L becomes longer (for example, 650 nm or the like). Also, the light emitted by the excitation of the phosphor layer 21 may be emitted from the phosphor layer 21 as it is, but a part of the light goes toward the lower circuit pattern layer 22. And a part of the light is emitted to the outside by reflection in the circuit pattern layer 22. As described above, when the wavelength of the light due to the excitation of the phosphor in the phosphor layer 21 is 600 nm or more, a reflection effect can be expected even if the circuit pattern layer 22 is made of Cu. Note that depending on the type of phosphor in the phosphor layer 21, the wavelength of the light L is different from the above example, but in any case, the wavelength conversion of the light L will be performed. For example, when the wavelength of the light emitted by the excitation of the phosphor layer 21 is less than 600 nm, a reflection effect can be expected by making the circuit pattern layer 22 or its surface, for example, Ag (plating). Or, even if a white reflective layer is provided on the lower side (insulating layer 23 side) of the phosphor layer 21, a similar effect can be expected. The reflective layer is formed of, for example, a white paint such as a titanium oxide filler.

[0065] Through the above operations, the light emitted from the light-emitting module 12 is irradiated from the road lighting device 100 via the light distribution adjustment unit 14. According to the road lighting device 100 according to the present embodiment, the following effects can be obtained. First, by having a plurality of light distribution adjustment units 14, a wide range can be illuminated. Also, since each light distribution adjustment unit 14 can be arranged asymmetrically, a design according to the site can be made.

[0066] 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 configurations other than those described above can also be adopted.

Explanation of Reference Numerals

[0067] 100 Road lighting device 101 Lower body case 101a Groove 102 Upper body case 102a First case part 102b Second case part 103 Support column connection 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 Light emitting surface 16 Heat sink 18 Barrel part 18a Thread 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 including a light emitting module and two or more light distribution adjusting parts, wherein the two or more light distribution adjusting parts are positioned so as not to overlap when viewed from a direction perpendicular to the light emitting module.

2. Among the two or more light distribution adjusting parts, at least one set of the light distribution adjusting parts is symmetrically positioned in cross section, The road lighting according to Claim 1.

3. Among the two or more light distribution adjusting parts, at least one set of the light distribution adjusting parts is formed by dividing at least two of one cylindrical lens, The road lighting according to Claim 1.

4. The light distribution adjusting part has a curved surface, and an angle formed by the normal lines of the curved surface at both ends of the curved surface is 90° or more, The road lighting according to any one of Claims 1 to 3.

5. Among the two or more light distribution adjusting parts, at least one set of the light distribution adjusting parts is positioned at a distance of more than 0 cm and 50 cm or less from each other, The road lighting according to any one of Claims 1 to 3.

6. At least one of the light distribution adjusting parts has an optical property different from the optical properties of the other light distribution adjusting parts, The road lighting according to any one of Claims 1 to 3.

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