Light source unit and road lighting device having the same

Abstract

A light source unit (10) of the present application includes: a light emitting module (12) having a substrate and a plurality of light emitting diode elements mounted on the substrate; and a light distribution adjusting portion (14) that is light-transmissive and covers the light emitting module (12). The substrate has a phosphor layer containing phosphor particles on a surface on which the light emitting diode elements are mounted. The light distribution adjusting portion (14) includes a portion having a convex shape outward from the substrate side, is separate from the plurality of light emitting diode elements and the phosphor layer, collectively covers the plurality of light emitting diode elements and the phosphor layer, and diffuses and distributes light emitted from the light emitting diode elements and light emitted from the phosphor layer.

Description

Technical Field

[0001] The present invention relates to a light source unit and a road lighting device having the light source unit installed to illuminate a surrounding area. Background Technology

[0002] Previously, fluorescent lamps, high-pressure mercury lamps, metal halide lamps, and sodium lamps were widely used as light sources in road lighting systems for illuminating driveways, sidewalks, and other road surfaces. These lamps reflect light from the lamps using dome-shaped reflectors, providing sufficient brightness to illuminate wide areas such as roads. However, they consume a lot of electricity and have a relatively short lifespan. In recent years, LEDs, which consume less electricity and have a longer lifespan, have been used to replace these light sources (Patent Document 1).

[0003] like Figure 1 As shown, the road lighting devices 100 are arranged at predetermined intervals along the road. To uniformly illuminate the road from a safety perspective and further reduce the number of road lighting devices 100 installed, it is preferable to maximize the illumination range of the lighting beam. For example, as... Figure 1 As shown, by setting the illumination angle α to 60° to 65°, the illumination range can be the area directly below (a) and its surrounding area (b).

[0004] As prior art related to road lighting devices using LED lighting, Patent Document 2 discloses a road lighting device having multiple LED units with LEDs and reflective surfaces.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2009-99492

[0008] Patent Document 2: Japanese Patent Application Publication No. 2012-114001 Summary of the Invention

[0009] However, the prior art described in Patent Document 2 has the following problems.

[0010] In Patent Document 2, achieving the desired light distribution requires replacing the entire road lighting device, which presents issues of cost and labor. Furthermore, a significant portion of the light emitted from the LED units does not contribute to road illumination, resulting in low lighting efficiency. Consequently, in recent years, the standards required for road lighting have become increasingly stringent, with a growing demand for light distribution characteristics that can uniformly illuminate the entire road.

[0011] Based on the above, the objective of the present invention is to provide a light source unit with high lighting efficiency and capable of illuminating the entire road in a manner that provides uniform light distribution, and further, to provide a road lighting device equipped with the light source unit.

[0012] The inventors discovered that by using a phosphor substrate with multiple LED elements in an LED unit installed in a road lighting device, and further shaping a light-transmitting cover over the phosphor substrate into a predetermined shape, the above-mentioned problem can be solved, thus completing the present invention.

[0013] Furthermore, it was discovered that by having multiple phosphor substrates arranged at a predetermined angle, the aforementioned problems could be solved, thus completing the present invention.

[0014] That is, the present invention can be described as follows.

[0015] [1] A light source unit, comprising:

[0016] A light-emitting module having a substrate and a plurality of light-emitting diode elements mounted on the substrate; and

[0017] A light distribution adjustment section covering the light transmittance of the aforementioned light-emitting module;

[0018] The substrate described above has a phosphor layer containing phosphor particles on the surface on which the light-emitting diode element is mounted.

[0019] The light distribution adjustment section includes a portion having a convex shape extending outward from the substrate side. It is separate from the plurality of light-emitting diode elements and the phosphor layer, and together they cover the plurality of light-emitting diode elements and the phosphor layer, so that the emitted light from the light-emitting diode elements and the light emitted from the phosphor layer are diffused and distributed.

[0020] [2] In the light source unit described in [1],

[0021] The light distribution adjustment section emits the light emitted from the light-emitting diode element and the light emitted from the phosphor layer, and distributes the light in a bat-wing-shaped illuminance distribution.

[0022] [3] In the light source unit described in [1] or [2],

[0023] The aforementioned light distribution adjustment section includes a convex curved surface that protrudes outward from the substrate side.

[0024] [4] In the light source unit described in [3],

[0025] The aforementioned light distribution adjustment section has a bowl-shaped or semi-cylindrical shape.

[0026] [5] In the light source unit described in [3] or [4],

[0027] The aforementioned substrate has a rectangular shape.

[0028] In the aforementioned light distribution adjustment section, the emission surfaces from the emitted light of the aforementioned light-emitting diode element and the light emitted from the aforementioned phosphor layer are convex curved surfaces.

[0029] In a cross-sectional view of a plane orthogonal to the long side direction and the surface direction of the substrate and passing through the center of the substrate, when the thickness of the normal direction of the convex surface of the light distribution adjustment part is set as d, the thickness d at the end of the convex surface is greater than the thickness d at the top of the convex surface.

[0030] [6] In the light source unit described in [5],

[0031] The value of the thickness d gradually increases from the top of the convex surface to the end of the convex surface.

[0032] [7] In the light source unit described in [1],

[0033] The light distribution adjustment section described above includes: a light-receiving surface for receiving light emitted from the light-emitting diode element and light emitted from the phosphor layer; and an emission surface for emitting the received light.

[0034] The aforementioned emission surface of the light distribution adjustment section includes a concave-convex shape consisting of an outwardly protruding ridge and a valley adjacent to the ridge and recessed inward.

[0035] [8] In the light source unit described in [1],

[0036] The aforementioned light distribution adjustment section includes a cylindrical lens section.

[0037] [9] In the light source unit described in [1],

[0038] The aforementioned light distribution adjustment section includes a Fresnel lens section.

[0039]

[10] In any one of the light source units described in [1] to [9],

[0040] The aforementioned light-emitting module includes a first light-emitting module and a second light-emitting module.

[0041] The first and second light-emitting modules do not exist in the same plane.

[0042] The angle formed between the back side of the substrate on which the light-emitting diode element is mounted in the first light-emitting module and the back side of the substrate on which the light-emitting diode element is mounted in the second light-emitting module is 0° to 120°.

[0043]

[11] A light source unit, comprising:

[0044] A light-emitting module having a substrate and a plurality of light-emitting diode elements mounted on the substrate; and

[0045] A light distribution adjustment section covering the light transmittance of the aforementioned light-emitting module;

[0046] The substrate described above has a phosphor layer containing phosphor particles on the surface on which the light-emitting diode element is mounted.

[0047] The aforementioned light-emitting module includes a first light-emitting module and a second light-emitting module.

[0048] The first and second light-emitting modules do not exist in the same plane.

[0049] The angle formed between the back side of the mounting surface of the LED element of the first light-emitting module and the back side of the mounting surface of the LED element of the second light-emitting module is 0 to 120°.

[0050]

[12] In any one of the light source units described in [1] to

[11] ,

[0051] The aforementioned light source unit has a heat sink on the side opposite to the surface of the substrate on which the light-emitting diode element is mounted.

[0052]

[13] In the light source unit described in

[12] ,

[0053] The aforementioned light source unit is equipped with a cooling fan.

[0054]

[14] In any one of the light source units described in [1] to

[13] ,

[0055] The aforementioned phosphor particles include those selected from CASN-based phosphors, SCASN-based phosphors, and La3Si6N. 11 One or more of the following: phosphotron, Sr2Si5N8 phosphotron, Ba2Si5N8 phosphotron, α-type silon phosphotron, β-type silon phosphotron, LuAG phosphotron, and YAG phosphotron.

[0056]

[15] In any one of the light source units described in [1] to

[14] ,

[0057] The median particle size D of the above fluorescent particles 50 The range is from 1μm to 20μm.

[0058]

[16] In any one of the light source units described in [1] to

[15] ,

[0059] The thickness of the aforementioned phosphor layer is less than 150 μm.

[0060]

[17] In any one of the light source units described in [1] to

[16] ,

[0061] The aforementioned phosphor layer comprises a transparent resin that is transparent to visible light and phosphor particles dispersed in the transparent resin.

[0062]

[18] In any one of the light source units described in [1] to

[17] ,

[0063] The aforementioned phosphor layer is a cured product of the phosphor coating.

[0064] The aforementioned phosphor coating comprises phosphor particles and curable resin components.

[0065]

[19] In the light source unit described in

[18] ,

[0066] The aforementioned curable resin component contains one or more selected from silicone resins and (meth)acrylate monomers.

[0067]

[20] In any one of the light source units described in [1] to

[19] ,

[0068] It is used for road lighting.

[0069]

[21] In any one of the light source units described in [1] to

[20] ,

[0070] When the fluorescence peak wavelength of the phosphor particles is set as λ1 when the emission of the above-mentioned light-emitting diode element is used as the excitation light, and the emission wavelength of the above-mentioned light-emitting diode element is set as λ2, the absolute value of the difference between λ1 and λ2, Δλ, is 50 nm or less.

[0071]

[22] The light source unit described in any one of [1] to

[21] includes:

[0072] The main body has the aforementioned light-emitting modules;

[0073] The aforementioned light distribution adjustment unit can be mounted and dismounted relative to the aforementioned main body.

[0074]

[23] In any one of [1] to

[22] , the light source unit has:

[0075] Mounting section, for detachable mounting to the housing of a road lighting device.

[0076]

[24] A road lighting device comprising a housing and a light source unit housed within the housing,

[0077] The aforementioned housing has:

[0078] The window allows light emitted from the aforementioned light source unit to pass through; and

[0079] The light source unit mounting section is used to mount the aforementioned light source unit.

[0080] The aforementioned light source unit is the light source unit described in

[23] .

[0081] The aforementioned light source unit is detachably mounted on the aforementioned light source unit mounting section.

[0082] The light source unit and road lighting device of the present invention include: a substrate having a phosphor layer; and a light distribution adjustment section having a specific shape and the characteristic of diffusing and distributing the emitted light from the light-emitting diode element and the light emitted from the phosphor layer. The phosphor layer absorbs light emitted from the light-emitting diode element to the rear side opposite to the illumination direction, and emits fluorescence using this light as excitation light. The emitted beam composed of the phosphor and the emitted light from the light-emitting diode element contains components of various directions, making it difficult to directly achieve high lighting efficiency. Therefore, in the present invention, the emitted light from the phosphor and the light-emitting diode element is configured to be emitted outward through the light distribution adjustment section having the above-described shape and characteristics. Thus, according to the present invention, through the synergistic effect of the phosphor substrate and the light distribution adjustment section covering the light-emitting module, high lighting efficiency and uniform lighting characteristics that illuminate the entire road can be achieved.

[0083] According to the present invention, a light source unit with high lighting efficiency and capable of illuminating in a desired light distribution manner can be provided, and further, a road lighting device equipped with the light source unit can be provided. Attached Figure Description

[0084] Figure 1 This is a side view showing the condition of the road lighting device of this embodiment being configured.

[0085] Figure 2 This is a top view showing the condition of the road lighting device according to this embodiment.

[0086] Figure 3 This is a bottom view of the road lighting device of this embodiment.

[0087] Figure 4 yes Figure 3 A sectional view of the road lighting installation along line A-A'.

[0088] Figure 5 This is a plan view of the road lighting device of this embodiment viewed from above.

[0089] Figure 6 This is a side view of the road lighting device according to this embodiment.

[0090] Figure 7 This is a perspective view of the light source unit in this embodiment.

[0091] Figure 8 This is a perspective view showing the shape of the detached light distribution adjustment section of the light source unit in this embodiment.

[0092] Figure 9 This is a graph representing the illuminance distribution of a bat wing.

[0093] Figure 10(a) is a perspective view of the semi-cylindrical light distribution adjustment section (cylindrical lens), and Figure 10(b) is a cross-sectional view of the semi-cylindrical light distribution adjustment section (cylindrical lens) along line B-B'.

[0094] Figure 11(a) is a top view of the semi-cylindrical light distribution adjustment section (cylindrical lens), and Figure 11(b) is a side view of the semi-cylindrical light distribution adjustment section (cylindrical lens).

[0095] Figure 12(a) is a perspective view of the bowl-shaped light distribution adjustment section, and Figure 12(b) is a cross-sectional view of the bowl-shaped light distribution adjustment section along line C-C'.

[0096] Figure 13 This is a cross-sectional view of the light distribution adjustment section in other ways.

[0097] Figure 14 This is a cross-sectional view of another type of light distribution adjustment section (Fresnel lens).

[0098] Figure 15 This is a three-dimensional view of the semi-cylindrical light distribution adjustment section (Fresnel lens).

[0099] Figure 16 This is a three-dimensional view of another type of semi-cylindrical light distribution adjustment section (Fresnel lens).

[0100] Figure 17 This is a perspective view showing the positional relationship of the light-emitting modules in the first embodiment.

[0101] Figure 18 This is a perspective view showing the positional relationship of the light-emitting modules in the first embodiment.

[0102] Figure 19 This is a top view of the light-emitting module in the first embodiment.

[0103] Figure 20 This is a partial cross-sectional view of a light-emitting substrate, which is one embodiment of the light-emitting module in the first embodiment.

[0104] Figure 21 This is a diagram used to explain the light-emitting operation of the light-emitting substrate of the first embodiment.

[0105] Figures 22(a), 22(b) and 22(c) are diagrams illustrating the effect of the light-emitting module of the first embodiment.

[0106] Figure 23(a) is a cross-sectional view showing the angle of the two light-emitting modules in the light source unit of the second embodiment, and Figure 23(b) is a cross-sectional view showing the state in which the two light-emitting modules are arranged at an angle of 0°.

[0107] Figures 24(a), 24(b), 24(c) and 24(d) are diagrams illustrating the effect of the light-emitting module of the second embodiment. Detailed Implementation

[0108] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. It should be noted that in all the drawings, the same reference numerals are used to denote the same constituent elements, and descriptions are omitted where appropriate.

[0109] [First Embodiment]

[0110] A preferred embodiment of the road lighting device of this embodiment will be described using the accompanying drawings.

[0111] The configuration of the road lighting device 100 is shown in Figure 1 and Figure 2 . Figure 1 This shows a side view of a street light. Figure 2 This represents a top view. For example... Figure 1 As shown, each road lighting unit 100 is supported by a support post P. (See reference...) Figure 1 As explained, the illumination angle is set to 60° to 65°, and the illumination range includes the area below the road lighting device 100 (area a) and the surrounding area (area b).

[0112] Figure 3 This is a bottom view of the road lighting device 100. Figure 4 yes Figure 3 A-A' section view. Figure 5 This is a top view of the road lighting device 100. Figure 6 This is a side view of the road lighting device 100.

[0113] like Figure 3 As shown, the road lighting device 100 includes a housing and a light source unit 10 housed within the housing.

[0114] like Figure 3 , 5 As shown in Figure 6, the housing consists of a lower main body shell 101 and an upper main body shell 102. By combining them, as... Figure 4 As shown, a space a is formed inside to house the light source unit 10. Figure 6 As shown, the upper main body shell 102 is further composed of a first shell portion 102a located on the front side and a second shell portion 102b located on the rear side. Figure 3 In the middle, the left side faces the road side, and the pillar joint 103 is set on the right side.

[0115] Inside the lower main body housing 101, a threaded hole (not shown) is provided on the support joint 103 side, for mounting the light source unit. Figure 7 The threaded portion 18a of the light source unit 10 shown is screwed into the threaded hole, and the light source unit 10 is detachably mounted to the lower main body housing 101. Figure 3 and Figure 4 As shown, a window 104 is provided on the lower surface 101b of the lower main body housing 101, which can illuminate the road surface with light from the light source unit 10. The window 104 can be made of glass or resin. A plurality of heat dissipation grooves 101a are formed on the side of the lower main body housing 101.

[0116] [Light Source Unit]

[0117] like Figure 7 , Figure 8 As shown, the light source unit 10 of this embodiment includes a light-emitting module 12, a generally cylindrical main body 11 including the light-emitting module 12, and a light distribution adjustment section 14 detachably disposed on the main body 11. The main body 11 includes a torso 18 and a cooling fan 19 disposed at one end of the torso 18. It should be noted that in order to ensure the airflow (air circulation) from the cooling fan 19, the cooling fan 19 is usually covered by a cover (not shown).

[0118] like Figure 8 As shown, the body 18 is generally cylindrical, with a radially inwardly recessed portion in the center of its long side. The bottom surface of the recessed portion forms a plane, on which a light-emitting module 12 is mounted (fixed).

[0119] The body 18 has an internal space, as shown in FIG23, and a heat sink 16 is provided in the internal space. The heat sink 16 has multiple fins and is connected to the phosphor substrate of the light-emitting module 12. Furthermore, a power drive circuit and a temperature sensor are provided in this internal space. The drive circuit drives and controls the cooling fan 19, thereby controlling the internal temperature of the light source unit 10 within the desired temperature range.

[0120] The driving circuit includes an LED driver IC, capacitors, etc., and uses switching actions to control the on-time (off-time) of the driving element Q using PWM (Pulse Width Modulation), thereby controlling the current flowing through the LED chip to the desired value.

[0121] like Figure 7 , Figure 8As shown, the light distribution adjustment unit 14 is detachably mounted relative to the main body 11 (body 18), and can be replaced to achieve the desired light distribution. Therefore, component replacement of the main body 11 equipped with the light-emitting module 12 and replacement of the light distribution adjustment unit 14 become easy. Alternatively, a group consisting of a main body 11 equipped with one type of light-emitting module 12 and various light distribution adjustment units 14 with different light distribution characteristics can be used, allowing selection of an appropriate light distribution adjustment unit 14 based on the application environment to achieve the desired light distribution characteristics.

[0122] The light source unit 10 of this embodiment can be circulated as a group of light source units consisting of a main body 11 equipped with a light-emitting module 12 and various light distribution adjustment parts 14 with different light distribution characteristics. Depending on the environment in which the road lighting device 100 is installed, one type of light distribution adjustment part 14 can be selected from the group of light source units, and the selected light distribution adjustment part 14 can be installed on the main body 11 equipped with the light-emitting module 12 to form the light source unit 10. This light source unit 10 can then be installed as the light source of the road lighting device 100. Therefore, the desired light distribution characteristics can be achieved according to the environment in which the road lighting device 100 is installed.

[0123] Various methods can be considered as specific means of configuring the light distribution adjustment part 14 so that it can be attached to and detached from the main body 11 of the light source unit 10. In this embodiment, the light distribution adjustment part 14 is provided with a claw (not shown), and the body 18 of the light source unit 10 is provided with an engaging part (not shown) composed of a notch, a recess, or a protrusion, and the claw engages with the engaging part.

[0124] The torso 18 can be made of resin or metal.

[0125] The body 18 has a threaded portion (mounting portion) 18a at one end. The threaded portion 18a is formed, for example, by die casting of aluminum.

[0126] Inside the lower main body housing 101, a threaded hole is provided on the support joint 103 side. By screwing the threaded part 18a into the threaded hole, the light source unit 10 can be detachably installed on the lower main body housing 101. Furthermore, the light-emitting module 12 is electrically connected via the screwed threaded part 18a.

[0127] In prior art, such as Patent Document 2, the entire road lighting device needs to be replaced to achieve the desired light distribution, which involves costs and labor. According to the light source unit 10 of this embodiment, the desired light distribution can be achieved by simply replacing the light source used in the existing road lighting device (more specifically, the light distribution adjustment unit 14), thereby reducing costs and labor.

[0128] It should be noted that while radiators are exemplified as a means of heat dissipation, there are also heat dissipation openings and slits. The optimal heat dissipation method should be used appropriately based on the required heat dissipation performance, noise performance, and other factors.

[0129] [Light Distribution Adjustment Section]

[0130] like Figure 8 As shown, the light distribution adjustment part 14 is mounted to cover the light-emitting module 12 and has a convex shape extending outward from the side of the light-emitting module 12. That is, the outer surface of the light distribution adjustment part 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 part 14 is arbitrary, but preferably as shown in Figures 10 to 14 below. Figure 14 The so-called concave lens shape shown is (for example, a concave lens shape with an inner surface and an outer surface that is a convex lens shape, and a concave meniscus lens shape that thickens at the ends). As a result, the emitted light from the light-emitting module 12 can be diffused and emitted (illuminated) outward.

[0131] The shape of the light distribution adjustment section 14 can be a dome shape, a cylindrical shape, a Fresnel lens shape, or a curved shape.

[0132] The light distribution adjustment unit 14 receives the emitted light from the light-emitting module 12 and emits the received light to the outside. Examples of light distribution adjustment units 14 include transparent covers and transparent lenses. It should be noted that the light distribution adjustment unit 14 in this embodiment is configured to cover the entire light-emitting module 12 separately from the plurality of light-emitting diode elements and the phosphor layer (i.e., the plurality of light-emitting diode elements and the phosphor layer are common), unlike optical systems that cover each light-emitting diode element with resin or the like.

[0133] The light distribution adjustment section 14 can be made of a material that is transparent to the emission wavelength of the light-emitting diode element (LED, etc.). Examples of such transparent materials include thermoplastic resin, thermosetting resin, and glass. High heat resistance is preferred so that it can withstand the temperature rise inside the light source unit 10 caused by the heat generated by the light-emitting diode element.

[0134] Furthermore, from the viewpoint of molding and processability, thermoplastic or thermosetting resins are preferred, such as polyimide, polyacrylate, polysulfone, polyallyl sulfone, aromatic polyamide, aromatic polyetheramide, polyphenylene sulfide, polyallyl ether ketone, polyamide-imide, liquid crystal polyester, and polytetrafluoroethylene. The light distribution adjustment section 14 may include a diffusing agent, an ultraviolet absorber, an antioxidant, etc.

[0135] When the light distribution adjustment part 14 is made of resin, it can be manufactured by injection molding, compression molding, transfer molding, casting, etc.

[0136] In this embodiment, a coating may be provided on the surface of the emission surface of the light distribution adjustment section 14. Examples of such coatings include hard coatings, anti-reflective layers, and anti-fouling layers, and it may be a single layer or a stack of two or more layers.

[0137] The light distribution adjustment unit 14 can emit the light emitted from the light-emitting diode element and the light emitted from the phosphor layer, so as... Figure 9 The illuminance distribution of the bat wing shape shown is used for light distribution.

[0138] Based on the illuminance distribution of a bat wing, by suppressing the amount of light emitted directly below the road lighting device 100 and increasing the amount of light emitted in the inclined direction, the light distribution can be expanded, and the uneven brightness of the illuminated surface (i.e., the road) can be suppressed.

[0139] Here, the light distribution characteristics of bat wings are defined as follows: Figure 9 As shown, with the optical axis L as 0°, there is a luminous intensity distribution where the luminous intensity is stronger than that at angles where the absolute value of the light distribution angle is greater than 0°. It should be noted that the optical axis L is defined as a line passing through the center of the light-emitting module 12 and orthogonal to the plane of the substrate described later.

[0140] The shape of the light distribution adjustment section 14 is not particularly limited as long as it can distribute light in a bat wing-shaped illuminance distribution, but it can include a convex curved surface protruding outward from the side of the light-emitting module 12. Examples include a semi-cylindrical shape as shown in FIG10 and a bowl-shaped shape as shown in FIG12.

[0141] Figure 10(a) shows a perspective view of the light distribution adjustment unit 14, Figure 10(b) shows a cross-sectional view along line B-B' of Figure 10(a), Figure 11(a) shows a top view, and Figure 11(b) shows a side view.

[0142] As shown in Figure 10, the light distribution adjustment section 14 includes: a light-receiving surface 14a for receiving emitted light from the light-emitting diode element and light emitted from the phosphor layer; and an emission surface 14b for emitting the received light. The lower side (i.e., the side of the light-emitting module 12) of the light distribution adjustment section 14 is open. The light distribution adjustment section 14 is mounted on the heat sink 16 via the open end, covering the light-emitting module 12. The radius of curvature of the emission surface 14b can be approximately 42 mm.

[0143] The emission surface 14b is a convex curved surface that protrudes from the light-emitting module 12 toward the road surface side that becomes the object of illumination. It is configured to diffuse and distribute the emitted light from the light-emitting diode element and the light emitted from the phosphor layer.

[0144] As shown in the top view of the light distribution adjustment section 14 in Figure 11(a), as an example, the length 14a of the long side of the light distribution adjustment section 14 can be about 192 mm, the length 14b can be about 100 mm, the length 14c can be about 46 mm, the length 14d of the short side can be about 85 mm, the length 14e can be about 50 mm, and the length 14f (width of end a) can be about 17.5 mm.

[0145] As shown in the side view of the light distribution adjustment section 14 in Figure 11(b), as an example, the height 14g of the light distribution adjustment section 14 can be about 21mm.

[0146] Additionally, as shown in FIG12(a), the light distribution adjustment section 14 can also be bowl-shaped. As shown in FIG12(b) as a cross-sectional view along line C-C' of FIG12(a), it includes: a light-receiving surface 14a, which receives the emitted light from the light-emitting diode element and the light emitted from the phosphor layer; and an emission surface 14b, which emits the received light.

[0147] When the light distribution adjustment section 14 of Figure 10 or Figure 12 covers the light source unit 10 having a rectangular substrate, in a cross-sectional view (i.e. Figure 10(b) or Figure 12(b)) of a plane orthogonal to the long side direction and the surface direction of the substrate and passing through the center of the substrate, the thickness of the normal direction of the emission surface 14b (convex curved surface) of the light distribution adjustment section 14 is set as d. The thickness d1 of the end a of the emission surface 14b is greater than the thickness d2 of the top b of the emission surface 14b. More preferably, the value of the thickness d gradually increases from the top b of the emission surface 14b to the end a of the emission surface 14b.

[0148] From the viewpoint of achieving good light distribution characteristics, the ratio (d1 / d2) of the thickness d1 of end a to the thickness d2 of top b can be at least 6, preferably at least 8, and at least 10, preferably at least 16.

[0149] From the viewpoint of achieving good light distribution characteristics, the thickness d1 of end a can be at least 8 mm, preferably at least 10 mm, and at least 30 mm, preferably at least 25 mm.

[0150] From the viewpoint of achieving good light distribution characteristics, the thickness d2 of the top b can be at least 0.5 mm at the lower limit, preferably at least 1 mm, and at least 5 mm at the upper limit, preferably at least 3 mm.

[0151] In this embodiment, the light source unit 10, by appropriately selecting the material of the light distribution adjustment section 14 and further adjusting the thickness of each section and its overall shape, including its ratio, can emit the emitted light from the light-emitting diode element and the light emitted from the phosphor layer, so as... Figure 9 The illuminance distribution of the bat wing shape shown is used for light distribution.

[0152] When the road lighting device 100 of this embodiment is used for road lighting of vehicles, from the viewpoint of suppressing light diffusion to the vehicle side, the light distribution adjustment unit 14 may also include a cylindrical lens portion at the end a (the end connected to the main body 11) in the short side direction, as shown in FIG10. The cylindrical lens portion may be formed entirely of resin or the like, and the interior may be hollow.

[0153] In this embodiment, the long side direction refers to the axial direction of the generally cylindrical main body 11, and the short side direction refers to the direction orthogonal to the long side direction.

[0154] A cylindrical lens is a lens formed by dividing a cylinder along its axial direction, consisting of a curved surface on one side and a non-curved surface on the other.

[0155] Furthermore, the light distribution adjustment unit 14 shown in Figures 10 and 11 can be as follows: Figure 13 The cross-sectional view shows that the injection surface 14b has a concave-convex structure, which is composed of a ridge 14b-1 that protrudes outward and extends along the long side or circumferential direction of the injection surface 14b, and a valley 14b-2 that is adjacent to the ridge 14b-1, recessed inward and extends along the long side or circumferential direction of the injection surface 14b.

[0156] In addition, such as Figure 14 As shown in the cross-sectional view, a Fresnel lens portion may also be included at the end in the short side direction (the end connected to the main body 11).

[0157] A Fresnel lens is a lens whose thickness is reduced by machining the lens surface (the cylindrical lens portion at the end) into concentric circles, etc., and a prism with a mountain-shaped form is formed into a stepped structure. In addition, the aforementioned mountain-shaped prism can change the direction of light travel.

[0158] Figure 15 or Figure 16 An example of a light distribution adjustment unit 14, which includes a Fresnel lens section, is shown in a three-dimensional view. Figure 15 The light distribution adjustment unit 14 shown has a Fresnel lens unit instead of the cylindrical lens unit in FIG10. Figure 15 The cross-sectional view along line B-B' of the light distribution adjustment unit 14 shown is similar to... Figure 14 The sectional view is the same. Figure 16 The light distribution adjustment section 14 shown has a Fresnel lens section along its entire long side.

[0159] [Light-emitting module]

[0160] like Figure 8As shown, the light source unit 10 of this embodiment includes a rectangular light-emitting module 12. It should be noted that the shape of the light-emitting module 12 is not particularly limited and various shapes can be adopted.

[0161] In addition, in this embodiment, multiple light-emitting modules 10 can be provided, and the placement of the multiple light-emitting modules 10 can be changed to better achieve bat wing light distribution.

[0162] For example, it can be like Figure 17 The light-emitting module 12 shown is composed of a first light-emitting module 12a and a second light-emitting module 12b, and the first light-emitting module 12a and the second light-emitting module 12b are arranged along the short side of the light source unit 10. Alternatively, it can be arranged as follows: Figure 18 As shown, they are arranged along the long side.

[0163] From the perspective of achieving bat wing light distribution over a wide range, the preferred method is as follows: Figure 18 The first light-emitting module 12a and the second light-emitting module 12b are arranged along the long side of the substrate.

[0164] [Composition of the light-emitting module]

[0165] like Figure 19 As shown, the light-emitting module 12 has a phosphor substrate 30 and a plurality of light-emitting diode elements (LED chips) 20 mounted on the phosphor substrate 30. Moreover, the phosphor substrate 30 has a substrate and a phosphor layer, which is located on the surface of the substrate on which the light-emitting diode elements 20 are mounted and contains phosphor particles.

[0166] The substrate constituting the phosphor substrate is an insulating substrate, which appears rectangular when viewed from above. Multiple LED chips are arranged in a grid pattern on the rectangular substrate.

[0167] Reference Figure 20 and Figure 21 This explains the specific structure of the light-emitting diode element 20. Figure 20 This is a partial cross-sectional view of the light-emitting module 12, which shows the specific structure of the light-emitting diode element 20.

[0168] <Light Emitting Diode Components>

[0169] like Figure 20 As shown, the light-emitting diode elements 20 are CSPs (Chip Scale Packages) on which flip-chip LEDs 22 (hereinafter referred to as "LED22") are assembled. One or more light-emitting diode elements 20 are disposed on surface 31 (one side of an example) of phosphor substrate 30. It should be noted that the correlated color temperature of the light emitted by the light-emitting diode elements 20 is, for example, 3018K.

[0170] In addition, when the light-emitting diode element 20 is emitting light, the phosphor substrate 30 is cooled by using the heat sink 16 with the cooling fan 19, for example, by reducing the temperature from room temperature to a range of 50°C to 100°C.

[0171] Here, we would like to clarify the meaning of “~” used in numerical ranges in this specification. For example, “50℃~100℃” means “50℃~100℃”. Moreover, “~” used in numerical ranges in this specification means: the portion of the text above the “~” and the portion of the text below the “~”.

[0172] <Configuration of LED Components>

[0173] Preferably, multiple light-emitting diode elements 20 are disposed on the phosphor substrate 30. The light-emitting diode elements 20 are preferably arranged in an array or matrix on the phosphor substrate 30.

[0174] Examples of array-like structures include linear and zigzag patterns. Examples of matrix-like structures include... Figure 19 The grid-like configurations shown include square grids, staggered grids, and rhomboid grids.

[0175] In this embodiment, from the viewpoint of obtaining uniform emitted light from the light-emitting module 12, it is preferable to use, as shown in the example below. Figure 19 The grid-shaped configuration of the light-emitting diode element 20 is shown.

[0176] <Phosphor substrate>

[0177] like Figure 20 As shown, the phosphor substrate 30 of the embodiment includes an insulating layer 32 (an example of an insulating substrate), and an electrode layer 34 and a phosphor layer 36 disposed on its surface. A back pattern layer (not shown) may also be provided on the side of the phosphor substrate 30 opposite to the above-mentioned surface. As an example, the phosphor layer 36 is disposed on the surface 32a of the insulating layer 32 and the surface 34a of the electrode layer 34, and is disposed on the portion other than the surfaces of the plurality of electrode pairs 34A described later.

[0178] It should be noted that the phosphor substrate 30 in this embodiment is manufactured by processing (etching, etc.) a double-sided board (hereinafter referred to as "mother board MB") on both sides of an insulating board. As an example, the mother board MB is CS-3305A manufactured by Lichang Industrial Co., Ltd.

[0179] <Insulation layer>

[0180] The main features of the insulating layer 32 in this embodiment will be described below.

[0181] As an example, the shape is as described above, and it is rectangular when viewed from the surface 31 side and the back 33 side.

[0182] As an example, the material is an insulating material containing bismaleimide resin and glass cloth.

[0183] As an example, the thickness is 100μm to 200μm.

[0184] As an example, the coefficients of thermal expansion (CTE) in both the longitudinal and transverse directions are less than 10 ppm / ℃ in the range of 50℃ to 100℃. Alternatively, from another perspective, as an example, the coefficients of thermal expansion (CTE) in both the longitudinal and transverse directions are 6 ppm / ℃. This value is approximately the same as that of the light-emitting diode element 20 in this embodiment (90% to 110%, i.e., within ±10%).

[0185] As an example, the glass transition temperature is above 300°C.

[0186] As an example, the energy storage modulus is greater than 1.0 × 10⁻⁶ when the temperature range is 100℃ to 300℃. 10 Pa and less than 1.0 × 10 11 Pa.

[0187] <Electrode layer>

[0188] In this embodiment, the electrode layer 34 is a metal layer disposed on the surface 31 side of the insulating layer 32. As an example, the electrode layer 34 in this embodiment is a copper foil layer (a layer made of Cu). In other words, the electrode layer 34 contains copper at least on its surface.

[0189] The electrode layer 34 is formed as a pattern disposed on the insulating layer 32 and is conductive to terminals (not shown) to which connectors (not shown) are attached. Furthermore, the electrode layer 34 supplies power, either directly attached to wires or supplied from an external power source (e.g., a drive circuit) via the connector, to the light-emitting diode element 20 in the configuration of the light-emitting module 12. When there are multiple light-emitting diode elements 20, a portion of the electrode layer 34 becomes multiple electrode pairs 34A respectively bonded to the multiple light-emitting diode elements 20. As shown in the figure, as an example, the multiple electrode pairs 34A protrude further outward in the thickness direction of the insulating layer 32 (phosphor substrate 30) than the wiring portion 34B.

[0190] It should be noted that, for example, the area in the surface 32a of the insulating layer 32 where the electrode layer 34 is disposed (the area occupied by the electrode layer 34) is more than 60% of the surface 31 of the insulating layer 32.

[0191] From the viewpoint of supplying power to the light-emitting diode element 20, the phosphor substrate 30 of this embodiment preferably includes an electrode layer 34.

[0192] <Fluorescent layer>

[0193] As an example, in this embodiment, the phosphor layer 36 is disposed on the surface 32a of the insulating layer 32 and the surface 34a of the electrode layer 34, and is disposed on the portion other than the surfaces of the plurality of electrode pairs 34A. Moreover, in this embodiment, as an example, the area on the surface 31 of the insulating layer 32 in which the phosphor layer 36 is disposed is more than 80% of the area on the surface 31 of the insulating layer 32.

[0194] As an example, the phosphor layer 36 in this embodiment is an insulating layer comprising a phosphor and an organic binder resin, described later. The phosphor contained in the phosphor layer 36 consists of microparticles that are maintained in a state of dispersion in the organic binder resin, and has the property of exciting the light emitted by each light-emitting diode element 20 as excitation light. Specifically, the phosphor in this embodiment has the property that the peak wavelength of the emission when the light emitted by the light-emitting diode element 20 is used as excitation light is in the visible light region.

[0195] Phosphor layer 36 can be obtained by curing the phosphor coating.

[0196] <Fluorescent Coating>

[0197] The phosphor coating of this embodiment contains phosphor particles and curable resin components.

[0198] The phosphor coating of this embodiment contains phosphor particles in all non-volatile components at a rate of 25 vol% to 60 vol%.

[0199] The phosphor coating of this embodiment contains a curable "resin component" instead of a glass adhesive. Therefore, if the phosphor coating of this embodiment is used, sintering at high temperature is not required, and the phosphor layer 36 can be set relatively easily.

[0200] The elimination of the need for high-temperature sintering allows for greater flexibility in the selection of phosphors that can be used. Specifically, obtaining a cured film using glass adhesives requires sintering at approximately 600°C. This high temperature necessitates the selection of heat-resistant phosphors, potentially limiting their usability. Furthermore, peeling is prone to occur upon cooling from the high temperature. However, by using a curable resin component to prepare the phosphor coating, the approximately 600°C temperature is not required, allowing for the formation of a phosphor layer 36 that is less prone to peeling.

[0201] Not needing to sinter at high temperatures also brings the following advantages: fewer restrictions on the heat resistance and optimization of the coefficient of thermal expansion of the coated or printed shell / substrate.

[0202] Furthermore, by using curable resin components, a moderately thin phosphor layer 36 can be easily formed by coating or printing. This is particularly effective when the phosphor particle content in the phosphor coating is high.

[0203] In order to fully convert the light emitted from the light-emitting diode element into fluorescence and to prevent the light emitted from the light-emitting diode element from passing through the phosphor layer 36, the inventors have ensured that the phosphor particle content in all non-volatile components of the phosphor coating is 25 vol% or more.

[0204] By ensuring that the phosphor particles in all non-volatile components of the phosphor coating are at least 25 vol%, the light emitted from the light-emitting diode element can be fully converted into fluorescence, and other advantages can also be obtained.

[0205] One example of this advantage is improved coating or printing adaptability. By having a moderately high content of phosphor particles in the phosphor coating, the phosphor coating becomes moderately less flowable, resulting in the easy formation of a phosphor layer 36 of moderate thickness.

[0206] In addition, by making the content of phosphor particles in all non-volatile components of the phosphor coating more than 25 vol%, it also has the advantage that cracks are less likely to occur in the phosphor layer 36.

[0207] One reason for crack formation is believed to be the difference in thermal expansion coefficients between the phosphor layer 36 and the insulating layer 32 on which the phosphor layer 36 is disposed. By ensuring that the phosphor particle content in all non-volatile components of the phosphor coating is 25 vol% or more, the curable resin component is relatively reduced. Consequently, the difference in thermal expansion coefficient between the phosphor layer 36 and the insulating layer 32 on which the phosphor layer 36 is disposed becomes smaller. As a result, it is considered that cracks are less likely to form in the phosphor layer 36.

[0208] The phosphor particle content in all non-volatile components of the phosphor coating is preferably 30 vol% or more, more preferably 35 vol% or more. Therefore, even when the phosphor layer 36 is thin, for example, the light emitted from the light-emitting diode element 20 can be sufficiently converted into fluorescence, or the color temperature of the light emitted from the light-emitting diode element 20 can be significantly changed.

[0209] On the other hand, if the phosphor particle content in all non-volatile components of the phosphor coating is too high, the phosphor particles are prone to detaching from the formed phosphor layer 36. Therefore, the phosphor particle content in all non-volatile components of the phosphor coating is kept below 60 vol%.

[0210] The following describes the components and properties of the phosphor coating of this embodiment.

[0211] (Fluorescent particles)

[0212] The phosphor coating of this embodiment contains phosphor particles. The phosphor particles emit fluorescence simply by means of light emitted from a light-emitting diode element. Depending on the desired hue, color temperature, etc., only one type of phosphor particle may be used, or two or more types of phosphor particles may be used together.

[0213] In this embodiment, when the emission of light from the LED element 20 is used as the excitation light, the fluorescence peak wavelength of the phosphor particles is set as λ1, and the emission wavelength of the LED element 20 is set as λ2. The absolute value of the difference between λ1 and λ2, Δλ, is preferably 50 nm or less, more preferably 30 nm or less, and most preferably 20 nm or less. The lower limit of the absolute value Δλ is not particularly limited, and it can also be 0, that is, λ1 and λ2 are the same.

[0214] By making the absolute value Δλ within the above range, the emission wavelength from the fluorescent substrate 30 is approximately the same as the emission wavelength of the light-emitting diode element 20. Therefore, the overall emission of the light-emitting module 12 can be adjusted to the designed color temperature.

[0215] Examples of phosphor particles include those selected from CASN-based phosphors, SCASN-based phosphors, and La3Si6N. 11 It is one or more of the following: Siron-based phosphors, Sr₂Si₅N₈-based phosphors, Ba₂Si₅N₈-based phosphors, α-type silon-based phosphors, β-type silon-based phosphors, LuAG-based phosphors, and YAG-based phosphors. These phosphors typically contain activating elements such as Eu and Ce.

[0216] CASN-based phosphors (a type of nitride phosphor) preferably contain Eu. CASN-based phosphors, for example, refer to those composed of the formula CaAlSiN3:Eu. 2＋ Indicated by Eu 2＋ A red phosphor with an activator and a matrix of crystals composed of alkaline earth silicon nitrides.

[0217] In the definition of Eu-containing CASN-based fluorophores in this specification, Eu-containing SCASN-based fluorophores are excluded.

[0218] SCASN-based phosphors (a type of nitride phosphor) preferably contain Eu. SCASN-based phosphors, for example, refer to those derived from the formula (Sr, Ca)AlSiN3:Eu. 2＋ Indicated by Eu 2＋ A red phosphor with an activator and a matrix of crystals composed of alkaline earth silicon nitrides.

[0219] La3Si6N 11 The specific phosphor is La3Si6N 11 Ce phosphors, etc. This typically converts the blue light wavelength from a blue LED into yellow light.

[0220] The Sr2Si5N8 phosphor specifically refers to Sr2Si5N8:Eu 2＋ Phosphor, Sr2Si5N8:Ce 3＋ Phosphors, etc. They typically convert the blue light wavelength from a blue LED into yellow to red light.

[0221] Ba2Si5N8 phosphors are specifically Ba2Si5N8:Eu. This typically converts the blue light wavelength from a blue LED into orange to red light.

[0222] Alpha-type thionyl phosphors preferably contain Eu. Alpha-type thionyl phosphors containing Eu are, for example, derived from the general formula: M x Eu y Si 12－（m＋n） Al （m＋n） O n N 16－n In the general formula, M is an element selected from Li, Mg, Ca, Y and the lanthanides (excluding La and Ce) that contains at least one Ca. When the valence of M is set to a, ax + 2y = m, where x is 0 < x ≤ 1.5, 0.3 ≤ m < 4.5, and 0 < n < 2.25.

[0223] β-type thionyl phosphors preferably contain Eu. Eu-containing β-type thionyl phosphors are, for example, derived from Si of the general formula. 6－z Al z O z N 8－z Eu 2 ＋ (0 < Z ≤ 4.2) indicates that Eu has been dissolved in solid solution. 2＋ A phosphor composed of β-thiaron. In the general formula, the Z-value and europium content are not particularly limited. For example, a Z-value greater than 0 and less than 4.2 is preferred from the viewpoint of further improving the luminescence intensity of the β-thiaron to be 0.005 to 1.0. Furthermore, the europium content is preferably 0.1% to 2.0% by mass.

[0224] LuAG phosphors typically refer to lutetium aluminum garnet crystals. Considering their application in lighting devices, LuAG is preferably a LuAG:Ce phosphor. More specifically, LuAG can be composed of Lu3Al5O3. 12 The composition of Ce is represented by a formula, but the composition of LuAG does not necessarily have to follow stoichiometry.

[0225] YAG phosphors typically refer to yttrium aluminum garnet crystals. Considering their application in lighting devices, YAG phosphors are preferably activated with Ce. More specifically, YAG phosphors can be produced from Y3Al5O3. 12The composition of Ce is represented by a formula, but the composition of YAG-based phosphors does not necessarily have to follow stoichiometry.

[0226] Commercially available fluorescent particles can be used. Examples of commercially available fluorescent particles include ALONBRIGHT (a registered trademark) from Denka Co., Ltd. Additionally, Mitsubishi Chemical Co., Ltd. and others also offer commercially available products.

[0227] Median particle size D of fluorescent particles 50 Preferably, the particle size is 1 μm to 20 μm, more preferably 5 μm to 15 μm. This is achieved by appropriately adjusting the median particle size D. 50 For example, by adjusting the fluidity of the phosphor coating, it is easier to form a thin and uniform coating film.

[0228] In the particle size distribution curve of the phosphor particles, it is preferable to observe two or more maxima. Specifically, it is preferable to observe maxima in both the region with a particle size of 1 μm to 6 μm and the region with a particle size of 10 μm to 25 μm. Observing two or more maxima means that the phosphor particles include both large and small particles. Since small particles can enter the "gap" between large particles, it is easier to increase the phosphor particle content compared to using only large particles. In addition, even if the phosphor particle content is increased, it is easier to maintain the various properties of the coating. Furthermore, when the coating film is formed, the light emitted from the light-emitting diode element becomes less transparent.

[0229] Median particle size D of fluorescent particles 50 The particle size distribution curve can be adjusted by carefully designing the preparation method of the fluorescent particles, appropriately crushing the fluorescent particles, and appropriately mixing two or more fluorescent particles with different particle sizes.

[0230] The particle size distribution curve of phosphor particles can be determined using a laser diffraction scattering particle size distribution measuring device after the phosphor particles of the raw material are dispersed in a dispersion medium using an ultrasonic homogenizer. The median particle size D can then be calculated from the obtained particle size distribution curve. 50 For details regarding the dispersion treatment and measuring apparatus, please refer to the embodiments described later.

[0231] For the sake of caution, it should be noted beforehand that in this specification, the median particle size D is... 50 The particle size distribution curve is determined based on volume.

[0232] The phosphor coating of this embodiment may contain only one type of phosphor particle, or it may contain two or more types.

[0233] As described above, the phosphor particle content in all non-volatile components of the phosphor coating is 25 vol% to 60 vol%. This content is preferably 30 vol% to 60 vol%, more preferably 35 vol% to 60 vol%, and even more preferably 40 vol% to 50 vol%.

[0234] (Curing resin components)

[0235] The phosphor coating of this embodiment contains a curable resin component. By curing the phosphor coating, the resulting phosphor layer contains an organic binder resin.

[0236] In this specification, "curable resin component" includes not only (1) a resin (polymer) component that has the property of curing by the action of heat, light, etc., but also (2) a component that is a monomer or oligomer before the coating is formed, but can be polymerized by the action of heat, light, etc. after the coating is formed to form a resin (polymer).

[0237] In connection with the above, in this specification, in addition to polymers, monomers or oligomers, polymerization initiators, curing agents, etc. are also part of the "curable resin components".

[0238] When curable resin components contain resins, monomers, or oligomers, they are typically organic. That is, curable resin components typically contain organic resins, organic monomers, or organic oligomers.

[0239] The curable resin component preferably includes a thermosetting resin component. This allows for the manufacture of highly durable lighting devices. Of course, depending on the purpose and application, the curable resin component may also include a thermoplastic resin.

[0240] The curable resin component preferably includes one or more monomers selected from silicone resins and (meth)acrylate monomers. Among them, from the viewpoints of heat resistance and durability, silicone resins (resins having siloxane bonds as the main backbone) are preferred.

[0241] The curable resin component preferably contains an organosilicon resin having phenyl and / or methyl groups. Such an organosilicon resin is preferred in terms of compatibility with other components, solvent solubility, coatability, heat resistance, and durability. The phenyl:methyl ratio in this resin is, for example, about 0.3:1 to 1.5:1.

[0242] Curable resin components can contain reactive groups. Therefore, curable resin components can cure on their own.

[0243] As an example, the curable resin component is preferably an organosilicon resin containing silanol groups (-Si-OH). Thus, a condensation reaction of the silanol groups occurs during film formation, resulting in a cured coating film. The silanol content (OH mass%) of the organosilicon resin containing silanol groups (-Si-OH) is, for example, 0.1% to 5% by mass.

[0244] As another example, the curable resin component can be a resin that is cured by a hydrogen silanization reaction of a vinyl polymer and a Si-H-based organosilicon polymer (addition reaction type).

[0245] There is no particular limitation on the weight-average molecular weight of the resin contained in the curing resin component. As long as it can form a coating film, it can contain resins of any weight-average molecular weight.

[0246] As an example, the weight-average molecular weight of the resin contained in the curable resin component is usually below 1,000 to 1,000,000, preferably 1,000 to 500,000.

[0247] When using commercially available resins as components of a curable resin, the weight-average molecular weight can be obtained from catalog data. If the weight-average molecular weight cannot be obtained from a catalog or similar source, it can be determined, for example, by gel permeation chromatography (GPC) using polyethylene as a standard.

[0248] The resin included as a curing resin component can also be a commercially available product.

[0249] Commercially available silicone resins are available from companies such as Dow Corning Toray Industries, Ltd. and Shin-Etsu Chemical Industries, Ltd. Examples include RSN-0409, RSN-0431, RSN-0804, RSN-0805, RSN-0806, RSN-0808, RSN-0840 (manufactured by Dow Corning Toray Industries, Ltd.), KF-8010, X-22-161A, KF-105, X-22-163A, X-22-169AS, KF-6001, KF-2200, X-22-164A, X-22-162C, X-22-167C, and X-22-173BX (manufactured by Shin-Etsu Chemical Industries, Ltd.).

[0250] As mentioned above, curable resin components may include monomers or oligomers instead of resins.

[0251] For example, the curable resin component preferably contains a (meth)acrylate monomer. The (meth)acrylate monomer can be monofunctional or polyfunctional. The (meth)acrylate monomer preferably has 2 to 6 (meth)acrylate structures in one molecule.

[0252] The curable resin component preferably includes a polymerization initiator along with monomers and oligomers.

[0253] For example, when the curable resin component contains (meth)acrylate monomers, it is preferable to use it in conjunction with a free radical polymerization initiator. The free radical polymerization initiator generates free radicals through heat or active light.

[0254] In addition to the combination of silicone resin, (meth)acrylate monomer and polymerization initiator as described above, any component known in the coatings industry can be used as a curable resin component. Examples of curable resin components include (i) polyurethane-based components containing polyols and polyisocyanates, and (ii) epoxy-based components.

[0255] Examples of polyols that can be categorized as (i) include (meth)acrylic acid polyols, polyester polyols, polyether polyols, epoxy polyols, polyolefin polyols, fluorinated polyols, polycaprolactone polyols, polycaprolactam polyols, and polycarbonate polyols.

[0256] Examples of polyisocyanates as (i) include polyisocyanates with 2 to 6 functions, more preferably 2 to 4 functions. Specifically, examples include aliphatic diisocyanates, cyclic aliphatic diisocyanates, isocyanurates and biuret-type adducts that are polymers of isocyanate compounds, and substances obtained by adding isocyanate compounds to polyols or low molecular weight polyester resins. Biuret-type, isocyanurate-type, adduct-type, and urethane-type polyisocyanates are also known. All of these can be used.

[0257] (i) The polyisocyanate can be a so-called capped isocyanate. In other words, part or all of the isocyanate group of the polyisocyanate can be in the form of a capped isocyanate group that is capped by a protecting group. For example, the isocyanate group is capped by an active hydrogen compound such as an alcohol, phenol, lactam, oxime, or active methylene group to form a capped isocyanate group.

[0258] Commercially available polyisocyanates include, for example, the DURANATE series manufactured by Asahi Kasei Corporation, the TAKENATE series manufactured by Mitsui Chemicals Corporation, and the DESMODUR series manufactured by Sumitomo Chemical Bayer Polyurethanes Co., Ltd.

[0259] (ii) The curable resin components of epoxy systems typically include epoxy resin and its curing agent.

[0260] Examples of epoxy resins include bisphenol A type epoxy resin, halogenated bisphenol A type epoxy resin, phenolic varnish type epoxy resin, polyethylene glycol type epoxy resin, bisphenol F type epoxy resin, epoxidized oil, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, etc.

[0261] Common examples of curing agents include polyamines, amine adducts, polyamides, and acid anhydrides.

[0262] The phosphor coating of this embodiment may contain only one type of curable resin component, or it may contain two or more types.

[0263] The amount of curable resin component in the phosphor coating of this embodiment is preferably 40 vol% to 65 vol% of all non-volatile components, more preferably 45 vol% to 60 vol%.

[0264] (Liquidity Adjuster)

[0265] The phosphor coating of this embodiment preferably includes a flow modifier. Therefore, it is sometimes possible to adjust the flow characteristics and coatability of the coating.

[0266] As a flow modifier, silica particles such as hydrophobic silica and hydrophilic silica, as well as alumina, can be used. Fumed silica is particularly preferred.

[0267] Commercially available liquidity adjusters include, for example, AEROSIL 130, AEROSIL 200, AEROSIL 300, AEROSIL R-972, AEROSIL R-812, AEROSIL R-812S, Alminium OxideC (manufactured by NIPPON AEROSILCO., LTD., AEROSIL is a registered trademark), and CARPLEX FPS-1 (manufactured by DSL Corporation, trade name).

[0268] When the phosphor coating of this embodiment contains a flow modifier, it may contain only one type of flow modifier or two or more types of flow modifiers.

[0269] When the phosphor coating of this embodiment contains a flow modifier, its amount is, for example, 10 vol% or less, preferably 1 vol% to 5 vol% of all non-volatile components. On a mass basis rather than a volume basis, the amount of the flow modifier is, for example, 5 wt% or less, preferably 0.1 wt% to 5 wt% of all non-volatile components.

[0270] (solvent)

[0271] The phosphor coating of this embodiment preferably contains a solvent. This results in a phosphor coating with good coatability. The solvent includes water and / or an organic solvent.

[0272] Examples of organic solvents include hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

[0273] Preferred organic solvents include alcohol-based solvents. Specifically, examples include methanol, ethanol, n-propanol, 2-propanol, n-butanol, 2-butanol, and tert-butanol. Additionally, alcohols containing ether bonds, such as butylcarbitol (diethylene glycol monobutyl ether) and ethylcarbitol (diethylene glycol monoethyl ether), are also preferred. These are particularly advantageous from the viewpoint of effectively dissolving / dispersing the silicone resin to prepare phosphor coatings with good coatability, especially when using silicone resins as the resin.

[0274] Furthermore, the solvent preferably includes an aromatic hydrocarbon solvent. Especially when using silicone resins, it is easy to prepare phosphor coatings with a good balance of various properties by using them in combination with an aromatic hydrocarbon solvent. Examples of aromatic hydrocarbon solvents include toluene and xylene.

[0275] When using solvents, only one solvent may be used, or two or more solvents may be used in combination. For example, the aforementioned alcohol solvents and aromatic hydrocarbon solvents may be used in combination. When using solvents in combination, from the viewpoint of fully obtaining the effect of combination, each solvent preferably contains at least 1% by mass of the total solvent volume.

[0276] When the phosphor coating of this embodiment contains a solvent, it is preferable to include the solvent in an amount where the concentration of non-volatile components is 90% by mass or less. However, the concentration of non-volatile components is not limited to this; it can be adjusted to an appropriate amount as long as a coating film can be formed.

[0277] (Other ingredients)

[0278] The phosphor coating of this embodiment may contain other components besides those described above. Examples of other components include rust-preventive pigments, filler pigments, surface conditioners, waxes, defoamers, dispersants, ultraviolet absorbers, light stabilizers, antioxidants, leveling agents, anti-wrinkle agents, plasticizers, and charge control agents.

[0279] (Viscosity)

[0280] The viscosity of the phosphor coating in this embodiment is preferably adjusted appropriately. By adjusting the viscosity appropriately, the coatability and the ease of forming a thin coating film can be further improved.

[0281] Specifically, using a Type B viscometer, the viscosity of the phosphor coating, measured at 25°C and 20 rpm, is preferably 60 dPs·s to 500 dPa·s, more preferably 80 dPs·s to 400 dPa·s. Setting this viscosity particularly improves film-forming properties when forming the coating by screen printing. When forming the coating by methods other than screen printing, the suitable viscosity may differ from the above range.

[0282] (Forms of coatings)

[0283] The phosphor coating of this embodiment can be a single-liquid type or a multi-liquid type with two or more liquids. Specifically, the phosphor coating of this embodiment can be supplied in the form of a single-liquid composition in which all necessary components are uniformly mixed or dispersed. Alternatively, the phosphor coating of this embodiment can also be supplied in the form of a two-liquid type (a two-liquid kit) containing a portion of the components in liquid A and a portion of the components in liquid B.

[0284] From the perspective of preservation stability before coating, it is sometimes preferable to use a multi-liquid type of phosphor coating.

[0285] In this embodiment, when the phosphor coating is a multi-liquid type, the liquids are uniformly mixed just before the coating film is formed to obtain the coating for application. In this coating for application, the content of phosphor particles in all non-volatile components is 25 vol% to 50 vol%.

[0286] The phosphor coating described above can be used to manufacture a phosphor substrate 30 having a phosphor layer 36 containing phosphor particles.

[0287] There are no particular limitations on the coating method. For example, various coating machines known in the coatings industry can be used to coat the coating composition. Alternatively, the coating composition can also be coated by printing methods such as screen printing.

[0288] After coating, it is preferable to perform drying and curing treatments. Drying conditions are, for example, 60°C to 100°C for 15 to 60 minutes. Curing conditions are, for example, 100°C to 200°C for 30 to 240 minutes.

[0289] The coating amount of the phosphor coating is adjusted so that the thickness of the phosphor layer 36 is preferably less than 150 μm, more preferably 30 μm to 100 μm, and even more preferably 30 μm to 80 μm.

[0290] With a phosphor particle content of 25 vol% or more, preferably 30 vol% or more, and more preferably 35 vol% or more in the phosphor coating, even if the thickness of the phosphor layer 36 is 150 μm or less, the light emitted from the light-emitting diode element 20 can be sufficiently converted into fluorescence. In addition, the light emitted from the light-emitting diode element 20 does not easily penetrate the phosphor layer.

[0291] <Light emission operation of the light-emitting substrate in this embodiment>

[0292] Next, refer to Figure 21 The light-emitting operation of the light-emitting substrate 10 in this embodiment will be described. Here, Figure 21 This diagram illustrates the light-emitting operation of the light-emitting module 12 and demonstrates the light-emitting operation of the multiple light-emitting diode elements 20.

[0293] First, when the operating switch (e.g., the function of the drive circuit) that activates the light-emitting diode element 20 is turned on, power is supplied to the electrode layer 34 from commercial AC power via the drive circuit, and the multiple light-emitting diode elements 20 emit light L in a radial pattern. A portion of this light L reaches the surface 31 of the phosphor substrate 30. Hereinafter, the trajectory of the emitted light L will be described by distinguishing the direction of travel of the light L.

[0294] A portion of the light L emitted from each light-emitting diode element 20 is emitted to the outside instead of into the phosphor layer 36. In this case, the wavelength of the light L remains the same as the wavelength of the light L emitted from each light-emitting diode element 20.

[0295] In addition, the light L emitted from each light-emitting diode element 20 contains the light of the LED 22 itself and is incident on the phosphor layer 36. Here, the "light L contains the light of the LED 22 itself" refers to the light in the emitted light L that has not been color-converted by the phosphor of each light-emitting diode element 20 (CSP itself), that is, the light of the LED 22 itself (for example, blue light with a wavelength of about 470nm).

[0296] Furthermore, when the light L emitted by LED22 collides with the phosphor dispersed in phosphor layer 36, the phosphor is excited and emits excitation light. The reason for phosphor excitation here is that the phosphor dispersed in phosphor layer 36 uses phosphors with an excitation peak for blue light (visible light-excited phosphors). Consequently, a portion of the energy of light L is used for phosphor excitation, thus light L loses a portion of its energy. As a result, the wavelength of light L is converted (wavelength conversion occurs). For example, depending on the type of phosphor in phosphor layer 36 (e.g., in the case where red CASN phosphors are used), the wavelength of light L becomes longer (e.g., 650 nm, etc.).

[0297] Furthermore, the excitation light in the phosphor layer 36 sometimes continues to be emitted from the phosphor layer 36 as before, but a portion of the excitation light is directed towards the lower electrode layer 34. Moreover, a portion of the excitation light is reflected outwards by the electrode layer 34. As described above, when the wavelength of the excitation light emitted by the phosphor is 600 nm or higher, a reflection effect can be expected even if the electrode layer 34 is made of Cu. It should be noted that the wavelength of light L differs from the examples described above depending on the type of phosphor in the phosphor layer 36, but wavelength conversion of light L is performed in all cases. For example, when the wavelength of the excitation light is less than 600 nm, a reflection effect can be expected if the electrode layer 34 or its surface is, for example, made of Ag (gold plating). Alternatively, a reflective layer can be provided on the lower side of the phosphor layer 36 (on the insulating layer 32 side). The reflective layer is provided, for example, with a white coating such as titanium dioxide filler.

[0298] As described above, the light L emitted by each light-emitting diode element 20 (the light L emitted radially by each light-emitting diode element 20) is irradiated to the outside along with the excitation light through multiple optical paths as described above. Therefore, when the emission wavelength of the phosphor included in the phosphor layer 36 is different from the emission wavelength of the phosphor of the LED 22 in the sealed (or covered) light-emitting diode element 20 (CSP), the light-emitting substrate 10 of this embodiment irradiates the light beam emitted by each light-emitting diode element 20 as a light beam containing light L with a wavelength different from the wavelength of the light L emitted by each light-emitting diode element 20, along with the excitation light. For example, the light-emitting module 12 of this embodiment irradiates the light beam emitted by each light-emitting diode element 20 as a light beam containing light L with a wavelength longer than the wavelength of the light L emitted by each light-emitting diode element 20, along with the excitation light.

[0299] In contrast, when the emission wavelength of the phosphor contained in the phosphor layer 36 is the same as the emission wavelength of the phosphor of the LED 22 in the sealed (or covered) light-emitting diode element 20 (CSP) (in the case of the same correlated color temperature), the light-emitting module 12 of this embodiment irradiates the light beam emitted by each light-emitting diode element 20 as a light beam containing light L with the same wavelength as the light L emitted by each light-emitting diode element 20, together with the excitation light.

[0300] The above is a description of the light-emitting operation of the light-emitting module 12 in this embodiment.

[0301] [Effects of the first embodiment]

[0302] Next, the effects of this embodiment will be explained with reference to the accompanying drawings.

[0303] like Figure 1 As shown, the light distribution characteristics were confirmed using a road light fixture 100 supported by a 10m long support post P. The experimental results are shown in Figure 22(a), (b), and (c).

[0304] Photometric data (IES data) were obtained using a NeoLight 9500 from Pimacs, and optical simulations were performed using ZEMAX and DIALux.

[0305] Figures 22(a), (b), and (c) show cross-sectional views of the road lighting device 100. The cross-sectional views are as follows: Figure 4 shown Figure 3 The sectional view of the light source unit 10 in the A-A' line sectional view.

[0306] In Figure 22(a), the first light-emitting module 12a and the second light-emitting module 12b are arranged as follows: Figure 17The light-transmitting cover (light distribution adjustment part 14) is arranged along the short side to make the thickness d uniform. The thickness d is 1.75 mm.

[0307] In Figure 22(b), the first light-emitting module 12a and the second light-emitting module 12b are arranged as follows: Figure 17 The light-transmitting cover (light distribution adjustment part 14) is arranged along the short side as shown in Figure 10, with the thickness d2 of the top b being 1.75 mm and the thickness d1 of the end a being 17.6 mm.

[0308] In Figure 22(c), the first light-emitting module 12a and the second light-emitting module 12b are arranged as follows: Figure 18 As shown, they are arranged along the long side, otherwise the same as in Figure 22(b).

[0309] As shown in the light distribution diagram (row 3), the road lighting device 100 equipped with the light source unit 10 of FIG22(a) can make the lighting range a circular range, as shown in the illuminance distribution (rows 4 and 5), with high illuminance.

[0310] In contrast, the road lighting device 100 equipped with the light source unit 10 shown in Figures 22(b) and (c) can make the lighting range resemble a bat wing, which can illuminate a larger area and is particularly suitable for lighting devices for automobile roads.

[0311] [Second Embodiment]

[0312] The road lighting device in this embodiment is the same as that in the first embodiment, except for the shape of the light distribution adjustment section 14 constituting the light source unit 10 and the configuration of the light-emitting module 12, so the description is omitted.

[0313] The light source unit 10 in this embodiment differs from that in the first embodiment. By configuring the light-emitting modules, the emitted light from the light-emitting diode element and the light emitted from the phosphor layer are distributed in a bat-wing-shaped illuminance distribution.

[0314] Will Figure 3 A cross-sectional view of the light source unit 10 of this embodiment in the A-A' line cross-sectional view of the road lighting device 100 is shown in Figures 23(a) and (b). In Figures 23(a) and (b), the upper main body shell 102 and the window 104 are omitted.

[0315] The shape of the light distribution adjustment section 14 is the same as that in the first embodiment, and examples include a semi-cylindrical shape and a bowl shape. The thickness of the light distribution adjustment section 14 is generally the same, about 1.75 mm.

[0316] As shown in Figures 23(a) and (b), the light-emitting module 12 includes a first light-emitting module 12a and a second light-emitting module 12b. The first light-emitting module 12a and the second light-emitting module 12b do not exist in the same plane and are arranged along the short side of the light source unit 10.

[0317] By changing the angle β formed by the back side of the mounting surface of the LED element 20 of the first light-emitting module 12a and the back side of the mounting surface of the LED element 20 of the second light-emitting module 12b, a batwing-shaped light distribution can be achieved, with an angle of 0° to 120°, preferably 0° to 90°, and more preferably 0° to 60°. Figure 23(b) shows the case where the angle β is 0°.

[0318] Alternatively, the light distribution adjustment unit 14 of the first embodiment can be used instead of the light distribution adjustment unit 14 of the light source unit 10 of this embodiment.

[0319] [Effects of the second embodiment]

[0320] Next, the effects of this embodiment will be explained with reference to the accompanying drawings.

[0321] like Figure 1 As shown, the light distribution characteristics were confirmed using a road light that is supported by a 10m long support P for the road lighting device 100. The experimental results are shown in Figures 24(a) to (d).

[0322] Figures 24(a) to (d) show cross-sectional views of the road lighting device 100. These cross-sectional views are as follows: Figure 4 shown Figure 3 A-A' section view.

[0323] In Figure 24(a), the first light-emitting module 12a and the second light-emitting module 12b are arranged as follows: Figure 17 The light-transmitting cover (light distribution adjustment part 14) is arranged along the short side to make the thickness d uniform.

[0324] In Figure 24(b), the angle β between the first light-emitting module 12a and the second light-emitting module 12b is 120°, otherwise it is the same as in Figure 24(a).

[0325] In Figure 24(c), the angle β between the first light-emitting module 12a and the second light-emitting module 12b is 60°, otherwise it is the same as in Figure 24(a).

[0326] In Figure 24(d), the angle β between the first light-emitting module 12a and the second light-emitting module 12b is 0°, otherwise it is the same as in Figure 24(a).

[0327] As shown in the light distribution diagram (row 2), the road lighting device 100 in Figure 24(a) and (b) can make the lighting range a circular range, as shown in the illuminance distribution (row 3), with high illuminance.

[0328] As the angle β decreases, the illuminance distribution expands. The road lighting device 100 in Figures 24(c) and (d) can make the lighting range resemble a bat wing, which can illuminate a larger area and is particularly suitable for lighting devices for automobile roads.

[0329] The embodiments of the present invention have been described above, but these are merely examples of the present invention. Various configurations other than those described above may be used without impairing the effects of the present invention.

[0330] This application claims priority based on Japanese Patent Application No. 2021-047599, filed on March 22, 2021, the entire contents of which are incorporated herein by reference.

[0331] Symbol Explanation

[0332] 100 road lighting fixtures

[0333] P pillar

[0334] a Directly below area

[0335] b Surrounding area

[0336] 101 Lower Main Shell

[0337] 101a slot

[0338] 102 Upper Main Shell

[0339] 102a First outer casing section

[0340] 102b Second outer casing section

[0341] 103 Support joint

[0342] 104 Window

[0343] 10 light source units

[0344] 11 Main Body

[0345] 12 Light-emitting modules

[0346] 14 Light Distribution Adjustment Section

[0347] 14a Light-receiving surface

[0348] 14b Injection Surface

[0349] 14b1 Spine

[0350] 14b2 Tanibe

[0351] 16 Radiators

[0352] 18. Torso

[0353] 18a Threaded section

[0354] 19 Cooling Fan

[0355] 20 Light Emitting Diode Components

[0356] 22 LED

[0357] Surfaces 31, 32a, and 34a

[0358] 32 Insulation layer

[0359] 33 Back

[0360] 34 Electrode Layer

[0361] 34A electrode pair

[0362] 34B Wiring Section

[0363] 36 Fluorescent Layer

Claims

1. A light source unit, comprising: A light-emitting module having a substrate and a plurality of light-emitting diode elements mounted on the substrate; and A light distribution adjustment section covering the light transmittance of the light-emitting module; The substrate has a phosphor layer containing phosphor particles on the surface on which the light-emitting diode element is mounted. The light distribution adjustment section includes a portion with a convex shape extending outward from the substrate side, which is separate from the plurality of light-emitting diode elements and the phosphor layer, and together covers the plurality of light-emitting diode elements and the phosphor layer, so that the emitted light from the light-emitting diode elements and the light emitted from the phosphor layer are diffused and distributed; The light distribution adjustment section includes a convex curved surface protruding outward from the substrate side. The substrate has a rectangular shape. In the light distribution adjustment section, the emission surfaces of the light emitted from the LED element and the light emitted from the phosphor layer are convex curved surfaces. In a cross-sectional view of a plane orthogonal to the long side direction and the surface direction of the substrate and passing through the center of the substrate, when the thickness of the convex surface of the light distribution adjustment part in the normal direction is set as d, the thickness d at the end of the convex surface is greater than the thickness d at the top of the convex surface. The ratio when the thickness d of the top is set to d2 and the thickness d of the end a is set to d1, i.e., d1 / d2, is 6~16.

2. The light source unit according to claim 1, wherein, The light distribution adjustment section emits the light emitted from the light-emitting diode element and the light emitted from the phosphor layer, and performs light distribution with a bat wing-shaped illuminance distribution.

3. The light source unit according to claim 1, wherein, The light distribution adjustment section has a bowl-shaped or semi-cylindrical shape.

4. The light source unit according to claim 1, wherein, The thickness d gradually increases from the top of the convex surface to the end of the convex surface.

5. The light source unit according to claim 1, wherein, The light distribution adjustment section includes: a light-receiving surface for receiving emitted light from the light-emitting diode element and emitted light from the phosphor layer; and an emission surface for emitting the received light. The emission surface of the light distribution adjustment section includes a concave-convex shape consisting of an outwardly protruding ridge and a valley adjacent to the ridge and recessed inward.

6. The light source unit according to claim 1, wherein, The light distribution adjustment section includes a cylindrical lens section.

7. The light source unit according to claim 1, wherein, The light distribution adjustment section includes a Fresnel lens section.

8. The light source unit according to any one of claims 1 to 7, wherein, The light-emitting module includes a first light-emitting module and a second light-emitting module. The first and second light-emitting modules do not exist in the same plane. The angle formed between the back side of the substrate on which the light-emitting diode element is mounted in the first light-emitting module and the back side of the substrate on which the light-emitting diode element is mounted in the second light-emitting module is 0° to 120°.

9. A light source unit, comprising: A light-emitting module having a substrate and a plurality of light-emitting diode elements mounted on the substrate; and A light distribution adjustment section covering the light transmittance of the light-emitting module; The substrate has a phosphor layer containing phosphor particles on the surface on which the light-emitting diode element is mounted. The light-emitting module includes a first light-emitting module and a second light-emitting module. The first and second light-emitting modules do not exist in the same plane. The angle formed between the back side of the mounting surface of the LED element of the first light-emitting module and the back side of the mounting surface of the LED element of the second light-emitting module is 0 to 120°. The light distribution adjustment section includes a convex curved surface protruding outward from the substrate side. The substrate has a rectangular shape. In the light distribution adjustment section, the emission surfaces of the light emitted from the LED element and the light emitted from the phosphor layer are convex curved surfaces. In a cross-sectional view of a plane orthogonal to the long side direction and the surface direction of the substrate and passing through the center of the substrate, when the thickness of the convex surface of the light distribution adjustment part in the normal direction is set as d, the thickness d at the end of the convex surface is greater than the thickness d at the top of the convex surface. The ratio when the thickness d of the top is set to d2 and the thickness d of the end a is set to d1, i.e., d1 / d2, is 6~16.

10. The light source unit according to any one of claims 1 to 9, wherein, The light source unit has a heat sink on the side opposite to the surface of the substrate on which the light-emitting diode element is mounted.

11. The light source unit according to claim 10, wherein, The light source unit is equipped with a cooling fan.

12. The light source unit according to any one of claims 1 to 11, wherein, The phosphor particles comprise phosphors selected from CASN-based phosphors, SCASN-based phosphors, and La3Si6N. 11 One or more of the following: phosphotron, Sr2Si5N8 phosphotron, Ba2Si5N8 phosphotron, α-type silon phosphotron, β-type silon phosphotron, LuAG phosphotron, and YAG phosphotron.

13. The light source unit according to any one of claims 1 to 12, wherein, The median particle size D of the fluorescent particles 50 The range is from 1μm to 20μm.

14. The light source unit according to any one of claims 1 to 13, wherein, The thickness of the phosphor layer is less than 150 μm.

15. The light source unit according to any one of claims 1 to 14, wherein, The phosphor layer comprises a transparent resin that is transparent to visible light and phosphor particles dispersed in the transparent resin.

16. The light source unit according to any one of claims 1 to 15, wherein, The phosphor layer is a cured product of the phosphor coating. The phosphor coating comprises phosphor particles and a curable resin component.

17. The light source unit according to claim 16, wherein, The curable resin component contains one or more selected from silicone resins and (meth)acrylate monomers.

18. The light source unit according to any one of claims 1 to 17, used for road lighting.

19. The light source unit according to any one of claims 1 to 18, wherein, When the fluorescence peak wavelength of the phosphor particles is set as λ1 when the emission of the light-emitting diode element is used as the excitation light, and the emission wavelength of the light-emitting diode element is set as λ2, the absolute value of the difference between λ1 and λ2, Δλ, is less than 50 nm.

20. The light source unit according to any one of claims 1 to 19, wherein, have: The main body includes the light-emitting module; The light distribution adjustment unit can be mounted and dismounted relative to the main body.

21. The light source unit according to any one of claims 1 to 20, wherein, have: Mounting section, for detachable mounting to the housing of a road lighting device.

22. A road lighting device comprising a housing and a light source unit housed within the housing, The housing has: A window portion allows light emitted from the light source unit to pass through; and A light source unit mounting section for mounting the light source unit; The light source unit is the light source unit as described in claim 21. The light source unit is detachably mounted on the light source unit mounting section.

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