lighting fixtures

Abstract

To avoid illumination quality from being impaired by downsizing the illumination quality.SOLUTION: The luminaire includes a light source having a planar light emitting face 36 for emitting light, and a parabolic reflection surface 34 for controlling light from the light emitting face 36. The reflection surface 34 is arranged at a position where a focus FA of a paraboloid separates a predetermined distance LC from the light emitting face 36 along a designed optical axis KA, and it has a reflection film 70 provided on the surface for enhancing the reflection factor of predetermined-wavelength light and a plurality of concave facets 80 provided on the surface.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a lighting fixture. [Background technology]

[0002] BACKGROUND ART There is known a floodlight that controls light emitted from a planar light-emitting surface such as a COB type LED by a parabolic reflecting surface (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-147722 Summary of the Invention [Problem to be solved by the invention]

[0004] By shortening the length of the reflective surface in the optical axis direction, which corresponds to the height of the reflector, it is possible to reduce the size, weight, and cost of the floodlight. However, shortening the length of the reflective surface can cause uneven illuminance and reduce the quality of lighting.

[0005] The present invention is a miniaturization Even if Lighting Quality It is possible to increase The object is to provide a lighting fixture. [Means for solving the problem]

[0006] One aspect of the present invention is a lighting fixture comprising a light source having a planar light-emitting surface that emits light, and a parabolic reflecting surface that controls the light from the light-emitting surface, wherein the reflecting surface is provided with a plurality of facets, and when the direction of a designed optical axis of the reflecting surface is defined as the up-down direction and the exit-side open end of the reflecting surface is defined as the up-down direction, the reflecting surface is disposed such that a focal point (FA) of the paraboloid is spaced a predetermined distance above the light emitting surface along the design optical axis;The facet has, in a plan view seen from the concave opening side of the paraboloid, a lower side parallel to the circumferential direction of the design optical axis, an upper side parallel to the lower side at a predetermined height (HF) from the lower side, and a maximum width (WF) between the lower side and the upper side. dent and the facets have a shape 、 To provide a lighting fixture in which the facets are arranged side by side in the vertical direction and the overall shape of the facets becomes smaller as they approach the light emitting surface.

[0007] Another aspect of the present invention is the lighting fixture described above, The facets are set continuously without gaps. It is being used.

[0008] In another aspect of the present invention, in the above-described lighting fixture, among the facets, first concave facets aligned in the circumferential direction at the output side opening end have a shape such that the maximum width (WF) is a value obtained by dividing the circumferential length of the output side opening end by a predetermined coefficient number (Z), the length of the lower side is a length obtained by dividing the maximum width (WF) in half, both end positions (PF1, PF2) of the maximum width (WF) are positions that realize a concave shape with an amount of concavity such that the length of the lower side and the light distribution angle do not exceed a tolerance, and the length of the upper side (MAU) at the circumferential angle corresponding to the circumferential length is a predetermined height (HF), The Nth recess counting downward from the first recess The N+1 concave facet is its upper edge But the first one that touches above a value obtained by dividing the length of the circumferential direction of the reflecting surface that coincides with the bottom side of the Nth concave facet and that corresponds to the position of the (N+1)th concave facet by the number of coefficients (Z) is defined as a maximum width (WF), a length obtained by dividing the maximum width (WF) in half is defined as the length of the bottom side, and positions (PF1, PF2) at both ends of the maximum width (WF) are defined as positions that realize a concave shape such that the length of the bottom side and the light distribution angle do not exceed a tolerance; The length of the bottom side of the Nth concave facet is doubled The shape has the predetermined height (HF), and N is an integer of 1 or more. [Effects of the Invention]

[0009] According to the present invention, the miniaturization does not compromise the quality of the illumination. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of a floodlight according to an embodiment of the present invention, as viewed from the front side. [Figure 2] FIG. 2 is a perspective view of the floodlight according to the embodiment of the present invention, as viewed from the rear side. [Figure 3] 3 is a perspective view of the floodlight according to the embodiment of the present invention taken along line AA in FIG. 2. FIG. [Figure 4] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 5] FIG. 5 is an enlarged view of the range indicated by the arrow X in FIG. [Figure 6] FIG. 2 is a perspective view of the main body case from the rear side. [Figure 7] FIG. [Figure 8] FIG. 10 is a diagram showing test results of a noise test on a ground wire. [Figure 9] FIG. 2 is a plan view showing the configuration of an illumination unit. [Figure 10] FIG. 10 is a cross-sectional view taken along line BB in FIG. 9. [Figure 11] FIG. 10 is a diagram showing a simulation result of a light distribution shape in a cross section including a design optical axis for a normal reflecting surface. [Figure 12] FIG. 1 is a diagram showing the chromaticity characteristics of a COB-type LED. [Figure 13] FIG. 10 is a diagram showing a simulation result of a light distribution shape in a cross section including a design optical axis for a reflecting surface according to an embodiment of the present invention. [Figure 14] 10A and 10B are diagrams showing measurement results of the reflection characteristics of a reflecting surface according to an embodiment of the present invention. [Figure 15] FIG. 10 is a diagram showing measurement results of the radiation spectrum of the floodlight according to the embodiment of the present invention. [Figure 16] FIG. 2 is a perspective view showing the configuration of a reflecting surface according to an embodiment of the present invention. [Figure 17] 1A and 1B are diagrams showing the configuration of a concave facet, in which (A) is a plan view and (B) is a cross-sectional view. [Figure 18] FIG. 10 is an illustration of a concave facet design. [Figure 19]10A and 10B are diagrams showing the results of a simulation of the chromaticity distribution of light emitted from a reflecting surface according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a floodlight is exemplified as an example of a lighting fixture.

[0012] FIG. 1 is a perspective view of a floodlight 1 according to this embodiment, as viewed from the front side, and FIG. 2 is a perspective view of the floodlight 1, as viewed from the rear side. Floodlight 1 is an outdoor lighting fixture that is installed outdoors and can be used as a sign lighting fixture that illuminates building walls and signs, an area lighting fixture that illuminates a specific area such as an outdoor parking lot, and an illumination lighting fixture that lights up buildings, exhibits, plants, etc. As shown in Figure 1, the floodlight 1 comprises a fixture body 3 that emits illumination light from the front, and a support arm 4 that supports the fixture body 3 so that it can be tilted freely, and the emission direction of the illumination light can be changed by changing the tilt angle of the fixture body 3.

[0013] 3 is a perspective view of the floodlight 1 taken along line AA in FIG. 2, and FIG. 4 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 3 and 4, the appliance main body 3 of this embodiment includes a main body case 10 and a power supply case 12, which are separate bodies.

[0014] The main body case 10 is a shallow box-shaped case. As shown in Fig. 1, the main body case 10 has a rectangular shape when viewed from the front, an emission opening 14 that is generally rectangular when viewed from the front and emits illumination light is open to the front, and an illumination unit 13 is housed in a position facing the emission opening 14. The illumination unit 13 includes a light source for the illumination light and a light control member that controls the illumination light. In this embodiment, the light source is an LED 30, which is a type of semiconductor light-emitting element, and the light control member is a reflector 32.

[0015] A decorative frame 15 is attached to the front of the main body case 10, surrounding the periphery of the exit opening 14. The exit opening 14 is covered with a cover 16 made of an appropriate light-transmitting material, and as shown in Figure 3, the cover 16 is fixed between the decorative frame 15 and the main body case 10.

[0016] As shown in Fig. 2, support attachment pieces 17 are provided on both the left and right sides of the main body case 10. As shown in Fig. 1, each support attachment piece 17 extends toward the rear of the main body case 10, and the U-shaped support arm 4 is rotatably attached to it.

[0017] As shown in Figures 3 and 4, the power supply case 12 is a box-shaped case that incorporates a power supply unit 19 that supplies power for lighting to the lighting unit 13, and as shown in Figure 2, it is housed between a pair of support mounting pieces 17 behind the main body case 10. 3 and 4, the power supply case 12 includes a substantially rectangular bottom plate 20 and a bottomless, substantially rectangular parallelepiped cover body 22 that covers the bottom plate 20, with a circuit board 19A of the power supply device 19 fixed to the bottom plate 20. As shown in Fig. 2, ventilation cap members 23 are attached to the side surfaces 12A on both the left and right sides of the power supply case 12. The ventilation cap members 23 are members that have a ventilation structure and a waterproof structure and cover the ventilation holes that open in the side surfaces 12A.

[0018] As shown in FIG. 4, the power supply case 12 is fixed to the rear of the main body case 10 with a gap δ between them. The power supply case 12 is fixed using screws, and metal screws 24 (FIG. 2) that penetrate the bottom plate 20 of the power supply case 12 are screwed into screw holes 25 (FIG. 6) provided at multiple locations on the back surface 10A (FIG. 6) of the main body case 10, thereby fixing the power supply case 12. The screws 24 may be made of any suitable material, and in this embodiment, they are stainless steel. As will be described later, the surfaces of the power supply case 12 and the main body case 10, including the screw holes 25, are subjected to a surface treatment (insulating coating in this embodiment) to form an insulating layer, and therefore the engagement of the screws 24 with the screw holes 25 does not establish electrical continuity between the power supply case 12 and the main body case 10.

[0019] The fixture body 3 comprises a main body case 10 and a power supply case 12, each of which is separate, with the main body case 10 incorporating the lighting unit 13 and the power supply case 12 incorporating the power supply device 19. This allows the unit relating to the lighting unit 13 and the unit relating to the power source and various electrical circuits for lighting the lighting unit 13 to be produced separately, thereby improving production efficiency. Furthermore, since the heat generated by the lighting unit 13 is not directly transmitted to the power supply device 19, even if the heat resistance temperature of the electronic components of the power supply device 19 is lower than the heat resistance temperature of the lighting unit 13 (semiconductor light-emitting element of the light source), the lighting unit 13 is less likely to be limited by the heat resistance temperature of the electronic components, and the light output of the lighting unit 13 can be increased.

[0020] In this embodiment, the main body case 10 and the power supply case 12 are each aluminum die-cast products made of aluminum alloy, which is a type of metal. After casting, the main body case 10 and the power supply case 12 are each subjected to an insulating coating, which is an example of a surface treatment that forms an insulating layer. This means that the entire surface of the base material that is exposed to the outside is covered with an insulating layer made of an insulating coating film, thereby improving corrosion resistance and insulation.

[0021] Next, the grounding structure of the floodlight 1 will be described.

[0022] 3, a waterproof wire inlet 42 is provided on the bottom surface 12B of the power supply case 12, through which a power supply line 40 that transmits commercial power is drawn inside. The power supply line 40 includes a grounding wire 40A, which is electrically connected to the power supply case 12, thereby grounding the power supply case 12. In this embodiment, a grounding terminal (not shown) is provided on the bottom plate 20 inside the power supply case 12, and the power supply case 12 is grounded by connecting the grounding wire 40A to this grounding terminal.

[0023] As shown in FIG. 4, the device body 3 of this embodiment is provided with a grounding structure 50 that grounds the main body case 10 through the power supply case 12 by electrically connecting the main body case 10 and the power supply case 12 to each other.

[0024] FIG. 5 is an enlarged view of the area indicated by the arrow X in FIG. 4, which includes the ground structure 50. In FIG. In this embodiment, the grounding structure 50 is a structure that provides electrical conductivity between the rear surface 10A of the main body case 10 and the opposing surface 12C of the power supply case 12 that faces the rear surface 10A across the gap δ, via a wave washer 56. Specifically, the grounding structure 50 includes a first metal part 52 electrically connected to the main body case 10 and provided on the rear surface 10A of the main body case 10, a second metal part 54 electrically connected to the power supply case 12 and provided on the opposing surface 12C of the power supply case 12, and the above-mentioned metal wave washer 56 interposed between the first metal part 52 and the second metal part 54 and sandwiched between the first metal part 52 and the second metal part 54.

[0025] The grounding structure 50 of this embodiment further includes a seal portion 57 that seals the entire periphery of the area including the first metal portion 52, the second metal portion 54, and the wave washer 56, and the seal portion 57 prevents the first metal portion 52, the second metal portion 54, and the wave washer 56 from being wetted by rainwater or the like. This prevents electrolytic corrosion of the first metal portion 52, the second metal portion 54, and the wave washer 56 even when the floodlight 1 is used outdoors.

[0026] FIG. 6 is a perspective view of the floodlight 1 as viewed from the rear side. A wiring hole 61 is opened on the back surface 10A of the main body case 10, and wiring 60 drawn out from the power supply case 12 is drawn into the main body case 10 through the wiring hole 61. The wiring 60 is, for example, a power line that supplies power from the power supply device 19 to the lighting unit 13. The first metal portion 52 in this embodiment has a generally annular shape in a plan view that surrounds the periphery of the wiring hole 61, and is a flat metal surface formed by exposing the base metal of the main body case 10. The first metal portion 52 is formed by performing a surface treatment (insulating coating in this embodiment) of the main body case 10 while masking the formation area of ​​the first metal portion 52.

[0027] A wall portion 58 is formed on the outer periphery of the first metal portion 52, surrounding the first metal portion 52, and a wave washer 56 is housed inside the wall portion 58 on the surface of the first metal portion 52, positioned by the wall portion 58.

[0028] A groove 59 having a circular shape in a plan view is formed on the outer periphery of the wall portion 58, and as shown in Fig. 5, a packing 55, which is a component of the sealing portion 57, is fitted into the groove 59. In this embodiment, an O-ring is used for the packing 55. The packing 55 is compressed between the rear surface 10A and the opposing surface 12C of the power supply case 12, thereby sealing the inside of the packing 55 (i.e., the area including the first metal portion 52, the second metal portion 54, and the wave washer 56).

[0029] FIG. 7 is a perspective view of the wave washer 56. The wave washer 56 is a metal plate-like member that is annular in plan view. The wave washer 56 includes, within its plane, a plurality of first portions 56A that are bent in a convex direction relative to the flat surface of the first metal portion 52 and a plurality of second portions 56B that are bent in a concave direction relative to the flat surface of the first metal portion 52, and is an elastically deformable member that elastically deforms in the concave and convex directions of the first portions 56A and the second portions 56B.

[0030] 5, the second metal portion 54 provided on the power supply case 12 is a portion of the opposing surface 12C of the power supply case 12 that is deformed to have a convex shape toward the main case 10, and is formed in a circular ring shape in a plan view with approximately the same diameter as the first metal portion 52. Like the first metal portion 52, the tip portion 54A of the second metal portion 54 is masked during surface treatment (insulating coating in this embodiment) to expose the metal base of the power supply case 12, and this tip portion 54A presses the metal wave washer 56 toward the first metal portion 52, thereby elastically deforming the wave washer 56. In other words, the wave washer 56 is sandwiched between the first metal portion 52 and the second metal portion 54, each of which has its metal base exposed, due to the pressing of the first metal portion 52, and the first metal portion 52 and the second metal portion 54 are electrically connected via the wave washer 56.

[0031] Here, the amount of protrusion of second metal part 54 toward main body case 10 is slightly smaller than the gap δ between opposing surface 12C of power supply case 12 and rear surface 10A of main body case 10. This prevents gap δ from widening even if the amount of protrusion of second metal part 54 becomes slightly larger due to dimensional tolerances of parts, etc., and also prevents the sealing performance of seal part 57 from deteriorating due to the widening of gap δ. Furthermore, since the wave washer 56 is interposed between the first metal part 52 and the second metal part 54, even if there is a slight gap between the first metal part 52 and the second metal part 54, electrical continuity between the first metal part 52 and the second metal part 54 can be reliably achieved through the wave washer 56.

[0032] Furthermore, in the grounding structure 50 of this embodiment, the first metal part 52, the second metal part 54, and the wave washer 56 are all formed in a ring shape surrounding the wiring hole 61, so that a wiring path 62 is formed inside the sealing part 57, as shown in Fig. 5, and the wiring 60 extends from the power supply case 12 to the inside of the main body case 10 through this wiring path 62. This eliminates the need to provide a separate waterproof structure for the wiring 60, thereby reducing costs.

[0033] Incidentally, it is also possible to introduce an earth wire for grounding from the inside of the power supply case 12 through the wiring path 62 into the inside of the main body case 10, and to establish electrical continuity between the power supply case 12 and the main body case 10 through the earth wire. However, in this configuration, it is necessary to connect the ground wires inside the power supply case 12 and the main body case 10, which makes assembly difficult and increases manufacturing costs. In addition, since the ground wire extends inside the power supply case 12, the ground wire is affected by the electronic components (particularly the coil components) of the power supply device 19, which increases the noise. In contrast, the grounding structure 50 of this embodiment uses a wave washer 56 instead of an earth wire to establish electrical continuity between the power supply case 12 and the main body case 10, thereby improving assembly workability and preventing increases in costs and noise.

[0034] 8 is a diagram showing the test results of a ground wire noise test conducted on the floodlight 1 of this embodiment. In the figure, line L indicates the value (i.e., CISPR15) set by CISPR (Comite International Spécial des Perturbations Radioélectriques) regarding the allowable values ​​of radio interference characteristics of electric lighting and similar devices. As shown in the figure, in the ground structure 50 of this embodiment, when the wave washer 56 is not provided between the first metal portion 52 and the second metal portion 54, noise exceeding the line LX occurs in the frequency range indicated by the arrow NA. In contrast, when the wave washer 56 is provided, noise in this frequency range is suppressed, and it can be seen that a noise suppression effect is achieved.

[0035] In the floodlight 1 of this embodiment, the bottom plate 20 and cover body 22 of the power supply case 12 are separate parts, and electrical continuity between these parts is also required. For this reason, the above-mentioned wave washers 56 are provided at the mating portions of both parts, and the bottom plate 20 and cover body 22 are sandwiched between the wave washers 56 to ensure electrical continuity between them. This eliminates the need to connect the bottom plate 20 and cover body 22 with an earth wire, as with the electrical continuity between the power supply case 12 and main body case 10, and improves assembly workability.

[0036] The ground structure 50 of this embodiment can be modified as follows. For example, if there is no need to pass the wiring 60 through the inside of the ground structure 50, the first metal portion 52, the second metal portion 54, and the wave washer 56 do not have to have a circular ring shape in plan view. In addition, in the ground structure 50 of this embodiment, the configurations provided in the power supply case 12 and the main body case 10 may be interchanged. Furthermore, the first metal part 52 and the second metal part 54 may be any suitable conductive material that provides electrical continuity between the power supply case 12 and the main body case 10, and do not have to be the base material of the power supply case 12 and the main body case 10. Furthermore, the surface treatment of the power supply case 12 and the main body case 10 is not limited to insulating coating, and any surface treatment that forms an insulating layer on the surface may be used.

[0037] Next, the configuration of the illumination unit 13 will be described in detail.

[0038] FIG. 9 is a plan view showing the configuration of the illumination unit 13, and FIG. 10 is a cross-sectional view taken along line BB in FIG. As described above, the illumination unit 13 includes LEDs 30 as light sources and a reflecting mirror 32 as a light control member, and the reflecting mirror 32 is formed with a reflecting surface 34 that controls the light distribution of the LEDs 30. The illumination unit 13 of this embodiment includes four LEDs 30 for one reflecting mirror 32, and the reflecting mirror 32 is provided with a reflecting surface 34 for each LED 30. Each reflecting surface 34 is a parabolic surface that controls the emitted light to a predetermined luminous intensity distribution angle, and as shown in FIG. 9 , the exit-side open ends 35 of adjacent reflecting surfaces 34 are arranged so close together that they are almost in contact with each other, thereby reducing the planar dimensions of the reflecting mirror 32.

[0039] The LED 30 of this embodiment is a COB type LED (COB: Chip On Board) in which a large number of semiconductor light-emitting elements are densely arranged to form a light-emitting surface 36 that is approximately circular in plan view, and by using such a COB type LED as a light source, the output of the lighting unit 13 is increased.

[0040] Here, as shown in Figure 10, the length LA of each reflecting surface 34 in the direction of the design optical axis KA of the reflecting mirror 32 of this embodiment is shorter than that of a normal reflecting surface used for controlling the light distribution of an LED 30 having such a light-emitting surface 36, thereby reducing the thickness dimension of the reflecting mirror 32. This achieves a compact illumination unit 13 with reduced planar dimensions and thickness. Furthermore, by reducing the thickness of illumination unit 13, the depth of main body case 10 is also reduced. Therefore, in the fixture body 3 including main body case 10 and power supply case 12, even if power supply case 12 is disposed behind main body case 10, the depth of main body case 10 is reduced, thereby reducing the overall depth of fixture body 3, and the floodlight 1 can be made smaller, lighter, and less expensive.

[0041] However, if no measures are taken, the shorter the length LA of the reflective surface 34, the more noticeable unevenness in illuminance and color will become, resulting in a deterioration in lighting quality, and particularly in the case of signboard lighting, this will have adverse effects such as changing the color of the display surface of the sign.

[0042] To explain the occurrence of illuminance unevenness, if the length LA of the reflecting surface 34, which is long enough so that the light-emitting surface 36 of the LED 30 can be considered a point light source, is used as a reference, when the length LA of the reflecting surface 34 is shorter than the reference length, the emitted light components non-parallel to the design optical axis KA increase. As a result, the light distribution shape in a cross section including the design optical axis KA will have peaks on both sides of the design optical axis KA, as shown in Figure 11, resulting in a so-called "peak split" shape, with a reduced central luminous intensity (axial luminous intensity). As a result, illuminance unevenness will occur on the illuminated surface, with reduced illuminance in the center.

[0043] Next, to explain the occurrence of color unevenness, the COB-type LED used in the LED 30 of this embodiment has a fluorescent layer that covers each semiconductor light-emitting element and is excited by the light emitted by these semiconductor light-emitting elements to emit fluorescence. Each semiconductor light-emitting element emits blue light, and the fluorescent layer is excited by the blue light to emit yellow fluorescence, and the blue light and the yellow light from the fluorescence are mixed to emit white light. The color of the irradiated surface is a mixture of white light and yellow light, and when the length LA of the reflecting surface 34 is short, the non-parallel light component increases, causing the component containing a large amount of white light to be positioned away from the design optical axis KA, resulting in the peak splitting described above. As a result, the part of the irradiated surface corresponding to the design optical axis KA appears relatively yellowish.

[0044] In general, the chromaticity of the light emitted from a COB LED with such a configuration varies depending on the radiation angle α relative to the optical axis KB of the COB LED. Specifically, as shown in Figure 12, the chromaticity ΔCCY increases as the radiation angle α increases. Considering the white point on the xy chromaticity diagram, the chromaticity ΔCCY becomes more yellowish as y increases and more reddish as y decreases. Therefore, the yellowish chromaticity increases as ΔCCY increases. Therefore, if the radiation with a relatively large radiation angle α is blocked so that it does not enter the reflecting surface 34, the occurrence of yellow color unevenness can be suppressed. However, the optical efficiency decreases because part of the radiation light from the COB LED is not used for illumination. In addition, in COB LEDs, increasing the color deviation (Duv) can improve luminous efficiency. However, increasing the color deviation (Duv) makes the emitted color more yellowish, causing color unevenness. Note that color deviation (Duv) is a value that represents the deviation (deviation) from the blackbody radiation locus. Thus, in COB LEDs, the problem of color unevenness becomes more pronounced as the efficiency increases.

[0045] Therefore, the reflecting surface 34 of this embodiment is configured to be able to increase efficiency even with a short length LA, and also to suppress the occurrence of uneven illuminance and color. Specifically, the above-mentioned effect is achieved by differentiating the layout of the reflecting surface 34 from that of a normal design and further providing the reflecting film 70 and the concave facet 80 on the reflecting surface 34. This configuration will be described in detail below.

[0046] First, the arrangement of the reflecting surface 34 will be described. 10, the reflecting surface 34 of this embodiment is a paraboloid having a focal point FA, and in a normal design, it is disposed on the LED 30 so that this focal point FA is located on the light-emitting surface 36. In contrast, the reflecting surface 34 of this embodiment is disposed so that the focal point FA is spaced upward from the light-emitting surface 36 along the design optical axis KA by a predetermined distance LC (0.5 mm in this embodiment). With this arrangement, as shown in Fig. 13, the light distribution shape in the cross section including the design optical axis KA has a peak at the design optical axis KA, eliminating the "peak splitting" shown in Fig. 11. This maximizes the central luminous intensity (axial luminous intensity), suppressing the occurrence of uneven illuminance and color on the illuminated surface. The graph in FIG. 13 was obtained by simulating a reflecting surface 34 that does not include a reflecting film 70 and a concave facet 80, which will be described later.

[0047] Next, the reflective film 70 on the reflective surface 34 will be described. The reflective film 70 is a film that increases the reflectance of blue light and decreases the reflectance of yellow light compared to when the reflective film 70 is not provided, and is formed over the entire surface of the reflective surface 34 . The reflecting surface 34 of this embodiment is formed by forming an undercoat layer of suitable paint (in this embodiment, product name: UV-542 by Toyo Kogyo Toryo Co., Ltd.) on the surface of the base material of the reflecting mirror 32, and then forming an aluminum vapor deposition layer on top of that. The base material of this embodiment is made of ADC12, an aluminum alloy, but other suitable materials such as pure aluminum or a resin material can also be used for the base material.

[0048] 10, the reflective film 70 of this embodiment is formed by laminating a reflective film layer 71, a low-refractive-index material layer 72, and a high-refractive-index material layer 74, which have different refractive indices, on the surface of the reflective surface 34. In this embodiment, the reflective film layer 71 is made of aluminum with a purity of 99.99%, the low-refractive-index material layer 72 is made of SiO2 (refractive index: 1.46), and the high-refractive-index material layer 74 is made of TiO2 (refractive index: 2.5), which has a higher refractive index than the material of the low-refractive-index material layer 72. In addition to these materials, known or well-known reflective film materials such as Ta2O5 (refractive index: 2.16), ZrO2 (refractive index: 2.00 to 2.05), MgF2 (refractive index: 1.38 to 1.4), and Al2O3 (refractive index: 1.63) can be used for the low refractive index material layer 72 and the high refractive index material layer 74. The refractive index listed next to the material name is the value for a wavelength of approximately 550 nm.

[0049] In the reflective film 70 having such a configuration, the peak wavelength in the reflection characteristics can be changed by varying the film thickness of the low refractive index material layer 72 and the high refractive index material layer 74 in units of several nanometers.

[0050] FIG. 14 is a diagram showing the measurement results of the reflection characteristics of the reflecting surface 34 of this embodiment. The figure shows the measurement results for two reflecting surfaces 34, reflecting surface sample SA1 and reflecting surface sample SA2. Reflecting surface sample SA1 is a reflecting surface 34 having a reflecting film 70 designed to have a peak wavelength of 425 nm. Reflecting surface sample SA2 is a reflecting surface 34 having a reflecting film 70 designed to have a peak wavelength of 550 nm. As shown in the figure, it can be seen that the reflecting surface sample SA1 has reflection characteristics in which the reflectance is higher in the wavelength range R1 of blue light and lower in the wavelength range R2 of yellow light than the reflecting surface sample SA2.

[0051] FIG. 15 is a diagram showing the measurement results of the radiation spectrum of the projector 1. In FIG. The measurement results were obtained by measuring reflective surface samples SA3, SA4, and SA5 of reflective surface 34 using an irradiance meter at a point 3 meters away from projector 1. Reflective surface sample SA3 is reflective surface 34 having a reflective film 70 designed to have a peak wavelength of 300 nm, while reflective surface sample SA4 is reflective surface 34 having a reflective film 70 designed to have a peak wavelength of 450 nm. Reflective surface sample SA5 is reflective surface 34 having a reflective film 70 designed to have a peak wavelength of 500 nm. As shown in the figure, it can be seen that the radiation intensity in the wavelength range R2 of yellow light decreases as the peak wavelength decreases.

[0052] 14 and 15 show that the peak wavelength in the reflection characteristics is 450 nm or less, which is close to the wavelength range R1 of blue light, and that providing the reflective surface 34 with a reflective film 70 that increases the reflectance of blue light, which is the complementary color of yellow, reduces the reflectance of yellow light and increases the amount of blue light. Therefore, by using the light emitted from the reflective surface 34 having such a reflective film 70 as illumination light, it is possible to make yellow color unevenness on the illuminated surface less noticeable.

[0053] Next, the concave facet 80 will be described. Fig. 16 is a perspective view showing the configuration of the reflecting surface 34. Note that in Figs. 9 and 10, the concave facets 80 are omitted to avoid cluttering the drawings. As shown in FIG. 16, the reflecting surface 34 of this embodiment is provided with a series of concave facets 80 without any gaps.

[0054] 17A and 17B are diagrams showing the configuration of the concave facet 80, with FIG. 17A being a plan view and FIG. 17B being a cross-sectional view. The concave facet 80 suppresses color unevenness, and its planar shape as viewed from the concave opening side is hexagonal, as shown in Fig. 17(A). The diffusion of the emitted light can be adjusted by varying the dimensions of the planar shape of the concave facet 80 and the amount of concavity Q, and color unevenness can be suppressed by increasing the diffusion. However, since the greater the diffusion, the wider the light distribution angle becomes, in this embodiment, the concave facet 80 is designed so that the increase in light distribution angle is kept to approximately 6 degrees or less while suppressing color unevenness.

[0055] The design of such a concave facet 80 is as follows.

[0056] In the following description, the direction of the design optical axis KA of the reflecting surface 34 is defined as the up-down direction, and the exit-side opening end 35 (FIG. 5) of the reflecting surface 34 is defined as the up direction. 16, the concave facet 80 of this embodiment is arranged such that a pair of six sides are parallel to the circumferential direction DA of the reflecting surface 34. As shown in Fig. 17, of the six sides of the concave facet 80, the side that is located at the lowest end and parallel to the circumferential direction DA is referred to as a lower side 80D, and the side that faces and is parallel to the lower side 80D is referred to as an upper side 80U. The shortest distance from the upper side 80U to the lower side 80D is called the height HF, the maximum width of the concave facet 80 in the circumferential direction DA is called the width WF, and the shortest distance from the line segment MF indicating this width WF to the upper side 80U is called the upper length HUF. The concave amount Q of the concave facet 80 is the shortest distance from the opening surface 80P of the concave facet 80 to the most concave position.

[0057] To explain the design of the concave facet 80, first, the dimensions of the first concave facet 80-1 (FIG. 16) aligned in the circumferential direction DA at the emission side open end 35 are determined. Next, the dimensions of the second concave facet 80-2 that contacts the first concave facet 80-1 below are determined based on the dimensions of the first concave facet 80-1. Similarly, the dimensions of the Nth concave facet 80-N+1 that contacts the Nth concave facet 80-N below are determined based on the dimensions of the Nth concave facet 80-N.

[0058] The dimensions of the first concave facet 80-1 are determined as follows. First, as shown in Fig. 16, a parabola MA that defines the parabolic reflecting surface 34 is identified, and then a paraboloid 85 is obtained by rotating the parabola MA by an angle θ around the design optical axis KA, as shown in Fig. 18. The angle θ is the value obtained by dividing 360 degrees by the number Z of first concave facets 80-1 formed (=360 / Z), and the number Z is arbitrary. Then, in this paraboloid 85, the width WF is determined based on the length in the circumferential direction DA at a position corresponding to the line segment MF of the first concave facet 80-1.

[0059] Next, the length obtained by dividing the width WF in half is determined as the length of the bottom side 80D. Next, the concave amount Q is determined based on the following equation (1). Concave amount Q = [(width WF + length of bottom side 80D) / 2] × coefficient E (1) However, the coefficient E is a value determined according to the allowable value of the light distribution angle.

[0060] In formula (1), the larger the coefficient E, the larger the concave amount Q, resulting in greater diffusion and a larger light distribution angle, so the coefficient E is set within a range that does not cause the light distribution angle to exceed the allowable value. For example, if the coefficient E is around "0.1", the 1 / 10 beam angle will be within 50 degrees, and if it is "0.0008", the increase in the 1 / 10 beam angle (light distribution angle) will be within approximately 6 degrees.

[0061] Furthermore, by determining the width WF and the concave amount Q, two points PF1 and PF2 on the concave facet 80 spaced apart by WF are determined, as shown in Fig. 17(A), and a point PF4 (Fig. 17(B)) is determined by dividing the midpoint PF3 of these two points PF1 and PF2 by the concave amount Q. Then, the curved surface of the concave facet 80 is identified as a curved surface passing through each of these points PF1, PF2, and PF4.

[0062] Next, the length of the upper side MAU of the paraboloid 85 is determined to be the height HF. This upper side MAU is the side of the paraboloid 85 that extends at a position corresponding to the exit-side opening end 35 of the reflecting surface 34. The height HF is divided in half to form the upper length HUF. This determines the dimensions of the hexagonal shape in plan view and the concave amount Q (shape of the curved surface) for the first concave facet 80-1.

[0063] The N+1th concave facet 80-N+1 (N=an integer equal to or greater than 1) is designed as follows. That is, the width WF, the length of the lower side 80D, and the concave amount Q are set in the same manner as for the first concave facet 80-1, while the height HF is set to twice the length of the lower side 80D of the Nth concave facet 80-N. This determines the dimensions of the hexagonal shape in plan view and the concave amount Q (shape of the curved surface) for the N+1th concave facet 80-N+1.

[0064] 19 is a diagram showing the results of a simulation of the chromaticity distribution of light emitted from the reflecting surface 34 of this embodiment. The simulation in this figure was performed to determine the chromaticity distribution when the wall surface was illuminated with light emitted from the reflecting surface 34, with the design optical axis KA positioned on the wall surface. This simulation was performed on a reflecting surface 34 where the predetermined distance LC of the focal point FA from the light-emitting surface 36 was approximately 0.5 mm and the above-mentioned reflective film 70 was not provided. As shown in the figure, when the concave facet 80 is not provided on the reflecting surface 34, there is a significant difference in color temperature between the range T near the design optical axis KA and its surroundings, and the color temperature is higher in the range T. It can be seen that this difference in color temperature between the range T and its surroundings causes relatively large color unevenness. On the other hand, when the concave facet 80 is provided on the reflecting surface 34, although the 1 / 10 beam angle is increased by approximately 6 degrees, it is clear that the difference in color temperature is alleviated and color unevenness is eliminated.

[0065] In this way, although the length LA of the reflecting surface 34 of this embodiment is shorter than the standard, the focal point FA is positioned so as to be spaced apart from the light-emitting surface 36 along the design optical axis KA, thereby improving illuminance unevenness and color unevenness. Furthermore, the reflecting surface 34 of this embodiment is provided with a reflective film 70 that increases the reflectance of blue light, thereby improving color unevenness, and in addition, the provision of a concave facet 80 makes it possible to further reduce color unevenness while suppressing the spread of the light distribution angle.

[0066] The dimensions of the reflecting surface 34 and the like vary depending on the maximum diameter of the light emitting surface 36 . In this embodiment, light-emitting surface 36 is circular in plan view with a diameter of 5.5 mm, and correspondingly, reflecting surface 34 has a length LA of 22.8 mm. In this case, by setting the predetermined distance LC from light-emitting surface 36 to focal point FA to 0.5 mm, the peak wavelength in the reflection characteristics of reflective film 70 to 425 nm, and the dimensions of first concave facet 80-1, which are the basis for the dimensions of each of concave facets 80, to the following values, the increase in the light distribution angle is kept to approximately 6 degrees or less, and color unevenness is also suppressed. That is, the dimensions of the first concave facet 80-1 are a width WF of 5.7 mm, a concave amount Q of 0.0062 mm (coefficient E=0.0008), and a height HF of approximately 5.65 mm. The reflective film 70 has a reflective film layer 71 made of aluminum with a thickness of 100 to 200 nm, a low refractive index material layer 72 made of SiO2 with a thickness of 60 to 70 nm, and a high refractive index material layer 74 made of TiO2 with a thickness of 40 to 50 nm.

[0067] The reflecting surface 34 of this embodiment can be modified as follows. For example, the concave facets 80 do not necessarily need to be provided without gaps, and may be reduced to the extent that color unevenness and illuminance unevenness do not occur.

[0068] According to this embodiment, the following effects are achieved.

[0069] Floodlight 1 of this embodiment is a lighting fixture including main body case 10 that houses LEDs 30 and power supply case 12 that is electrically connected to ground wire 40A. Floodlight 1 also includes a grounding structure 50 that provides electrical continuity between main body case 10 and power supply case 12. Grounding structure 50 includes a first metal portion 52 provided on back surface 10A of main body case 10, a second metal portion 54 provided on the opposing surface 12C of power supply case 12, a conductive wave washer 56 that is sandwiched between first metal portion 52 and second metal portion 54 and elastically deforms, and a seal portion 57 that seals an area that includes first metal portion 52, second metal portion 54, and wave washer 56.

[0070] According to this configuration, the first metal part 52 and the second metal part 54 are electrically connected via the wave washer 56, so that even if there is a gap between the first metal part 52 and the second metal part 54, the first metal part 52 and the second metal part 54 can be reliably electrically connected through the wave washer 56. Furthermore, the sealing portion 57 prevents the first metal portion 52, the second metal portion 54, and the wave washer 56 from becoming wet, and prevents electrolytic corrosion of the first metal portion 52, the second metal portion 54, and the wave washer 56 even when the floodlight 1 is used outdoors.

[0071] In this embodiment, the main body case 10 and the power supply case 12 are each provided with an insulating layer except for the first metal portion 52 and the second metal portion 54 . This increases the corrosion resistance of the main body case 10 and the power supply case 12, while ensuring electrical continuity between them by the grounding structure 50. Furthermore, since electrolytic corrosion of the grounding structure 50 is prevented, peeling of the insulating layer due to the electrolytic corrosion can be prevented.

[0072] In this embodiment, the main body case 10 and the power supply case 12 are both made of metal, and the first metal part 52 and the second metal part 54 are both formed by exposing the metal base of the main body case 10 and the power supply case 12. This makes it possible to easily provide the first metal portion 52 and the second metal portion 54 by simply masking the areas where the first metal portion 52 and the second metal portion 54 are to be formed during surface treatment (insulating coating in this embodiment).

[0073] In this embodiment, the ground structure 50 has, in the area sealed by the seal portion 57, a wiring path 62 through which wiring 60 extending between the main body case 10 and the power supply case 12 passes. This eliminates the need to provide a waterproof structure for waterproofing the wiring path 62 separately from the ground structure portion 50, thereby reducing costs.

[0074] The floodlight 1 of this embodiment is a lighting fixture that includes an LED 30 having a planar light-emitting surface 36 that emits light, and a parabolic reflecting surface 34 that controls the light from the light-emitting surface 36. The parabolic focus FA of this reflecting surface 34 is located at a position separated from the light-emitting surface 36 along the design optical axis KA, and a reflective film 70 that increases the reflectance of blue light is provided on the surface, and a plurality of concave facets 80 are also provided on the surface.

[0075] According to this configuration, the focal point FA is positioned at a distance from the light-emitting surface 36 along the design optical axis KA, thereby improving illuminance unevenness and color unevenness, and the color unevenness is further improved by the reflective film 70.In addition, the concave facet 80 suppresses the spread of the light distribution angle while further suppressing color unevenness. As a result, even if the length LA of the reflecting surface 34 is made shorter than the standard, it is possible to suppress the occurrence of uneven illuminance and uneven color, and improve the lighting quality. Furthermore, by increasing the color deviation (Duv) of the LED 30 or allowing the light emitted from the LED 30 within a large radiation angle α to be incident on the reflecting surface 34, it is possible to increase efficiency while suppressing the occurrence of color unevenness.

[0076] In this embodiment, the reflective film 70 increases the reflectance of light of the complementary color (blue in this embodiment) of the target color of the color unevenness more than the reflectance of light of the target color of the color unevenness (yellow in this embodiment). As a result, when the light emitted from the reflecting surface 34 is white light, the color of the object of color unevenness can be reliably canceled out by the complementary color, thereby suppressing color unevenness.

[0077] In this embodiment, the increase in the light distribution angle of the concave facet 80 due to the concave amount Q is approximately 6 degrees or less, so that color unevenness can be improved while suppressing the spread of the emitted light.

[0078] The above-described embodiment is merely an example of one aspect of the present invention, and any modifications and applications are possible without departing from the spirit of the present invention.

[0079] For example, the present invention is not limited to being applied to floodlight 1, but can be applied to lighting fixtures for any purpose.

[0080] Unless otherwise specified, the horizontal, vertical, and other directions, various numerical values, shapes, and materials in the above-described embodiments include a range (so-called equivalent range) that has the same effect as those directions, numerical values, shapes, and materials. [Explanation of symbols]

[0081] 1. Floodlight (lighting equipment) 13 Lighting Department 32 Reflector 34 Reflective surface 35 Exit opening end 36 Light-emitting surface 70 Reflective film 72 refractive index material layer 74 refractive index material layer 80 concave facets FA focus KA design optical axis Q concavity

Claims

1. a light source having a planar light-emitting surface that emits light; a parabolic reflecting surface that controls the light from the light emitting surface; A lighting fixture comprising: The reflecting surface is provided with a plurality of facets; When the direction of the design optical axis of the reflecting surface is defined as the up-down direction and the exit side opening end of the reflecting surface is defined as the up direction, The reflective surface is The focus (FA) of the paraboloid is disposed so as to be spaced a predetermined distance above the light-emitting surface along the design optical axis, The facets are In a plan view seen from the concave opening side of the paraboloid, the paraboloid has a concave shape having a lower side parallel to the circumferential direction of the design optical axis, an upper side parallel to the lower side at a predetermined height (HF) from the lower side, and a maximum width (WF) between the lower side and the upper side, The facets are The facets are arranged side by side in the vertical direction, and the overall shape of the facets becomes smaller as they approach the light-emitting surface. Lighting fixtures.

2. The facets are provided continuously without any gaps.

10. The lighting fixture of claim 1.

3. The facets are hexagonal in plan view.

10. The lighting fixture of claim 1.

4. The facet is a concave shape that suppresses the spread of the light distribution angle of the light from the light emitting surface.

10. The lighting fixture of claim 1.

5. Among the facets, first concave facets arranged in the circumferential direction at the exit side opening end are a value obtained by dividing the circumferential length of the exit side opening end by a predetermined coefficient number (Z) is defined as the maximum width (WF), a length obtained by dividing the maximum width (WF) in half is defined as the length of the lower side, positions (PF1, PF2) at both ends of the maximum width (WF) are defined as positions that realize a concave shape in which the length of the lower side and the light distribution angle do not exceed an allowable value, and the length of the upper side (MAU) at the circumferential angle that corresponds to the circumferential length is defined as the predetermined height (HF), The Nth (N+1)th concave facet counting downward from the first concave facet is the upper side of the reflecting surface coincides with the lower side of the Nth concave facet that contacts it from above, the maximum width (WF) is the value obtained by dividing the circumferential length of the reflecting surface corresponding to the position of the N+1th concave facet by the number of coefficients (Z), the length of the lower side is the length obtained by dividing the maximum width (WF) in half, the positions (PF1, PF2) at both ends of the maximum width (WF) are positions that realize a concave shape with an amount of concavity such that the length of the lower side and the light distribution angle do not exceed an allowable value, and the predetermined height (HF) is the length obtained by doubling the length of the lower side of the Nth concave facet, The N is an integer of 1 or more.

5. A lighting fixture according to claim 4.

Images