JP7559660B2 - Lighting fixtures - Google Patents

Description

Patent Act Article 30, Paragraph 2 applies Exhibition date: March 9th to 12th, 2021 Exhibition name and location: 15th International Lighting Exhibition, Lighting Fair 2021, Tokyo Big Sight, West Hall 1 (3-11-1 Ariake, Koto-ku, Tokyo) [Publications, etc.] Sales date: March 25th, 2021 Sales location: Iwasaki Electric Co., Ltd. (1-1-7 Higashi-Nihonbashi, Chuo-ku, Tokyo) [Publications, etc.] Sales date: April 7th, 2021 Sales location: Iwasaki Electric Co., Ltd. (1-1-7 Higashi-Nihonbashi, Chuo-ku, Tokyo)

The present invention relates to a lighting fixture.

Patent Document 1 discloses a lighting fixture comprising a metal lighting fixture reflector having a surface covered with an insulating film coating, and a metal lighting fixture body to which the metal lighting fixture reflector is fixed, and which is earthed by connecting the metal lighting fixture body to a ground wire.
Patent Document 1 also shows that when earthing a metal lighting fixture reflector via a metal screw that fixes the metal lighting fixture reflector to the metal lighting fixture body, for example, by using a special toothed screw for the metal screw or by inserting a toothed washer between the general-purpose metal screw, the insulating coating film on the metal lighting fixture reflector can be peeled off and electrical continuity can be achieved between the metal lighting fixture reflector and the metal lighting fixture body.

JP 2011-34689 A

In Patent Document 1, if the metal screw and the metal lighting reflector are made of different materials, and the contact area between them is exposed to rainwater, etc., the difference in the ionization tendency between the two causes electrolytic corrosion at the conductive part between them. As a result, the insulating paint around the conductive part may deteriorate and peel off, or the screw hole in the metal lighting reflector may be damaged by corrosion, causing the metal screw to fall off.

The present invention aims to provide a lighting fixture that can suppress electrolytic corrosion of conductive parts used for grounding.

One aspect of the present invention is a lighting fixture comprising a first case housing a light source and a second case electrically connected to a ground wire, the lighting fixture comprising a ground structure for electrically connecting the first case and the second case, the ground structure comprising a first metal part provided on the surface of the first case, a second metal part provided on the surface of the second case, a conductive elastic deformation member that is sandwiched between the first metal part and the second metal part and elastically deforms, and a seal part that seals an area including the first metal part, the second metal part, and the elastic deformation member.

One aspect of the present invention is a lighting fixture including a first case that houses a light source and a second case that is electrically connected to a ground wire, the first case and the second case having a wiring hole through which a power line passes, and a grounding structure that electrically connects the first case and the second case and prevents water from getting into a wiring path through which the power line passes , the surface of the first case being provided with the grounding structure including a first metal part that is annular in plan view and surrounds the periphery of the wiring hole , a wall part that is annular in plan view and surrounds the first metal part from an outer periphery, and a groove part that is annular in plan view on the outer periphery of the wall part, and the surface of the second case being provided with the grounding structure a second metal part having a circular annular region facing the first metal part and convex toward the first metal part is provided as a part, a conductive elastic deformation member which is sandwiched between the first metal part and the second metal part and elastically deforms is arranged on the inner peripheral side of the wall part of the first case, an annular seal part which closes the gap between the first case and the second case is fitted into the groove part of the first case so as to seal an area including the first metal part, the second metal part, and the elastic deformation member, the elastic deformation member is a wave washer which is circular in a plan view, and the power supply line passes through a central hole of this wave washer .

Another aspect of the present invention is characterized in that, in the above-mentioned lighting device, the first case and the second case are both made of metal, and the first metal part and the second metal part are both formed by exposing the metal base of the first case and the second case.

The present invention makes it possible to suppress electrolytic corrosion of conductive parts used for grounding.

FIG. 2 is a perspective view of the front side of the floodlight according to the embodiment of the present invention. FIG. 2 is a perspective view of the floodlight as viewed from the rear side. 3 is a perspective view of the floodlight taken along line AA in FIG. 2. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 5 is an enlarged view of the area indicated by the arrow X in FIG. 4 . FIG. 2 is an exploded perspective view of the floodlight as viewed from the rear side. FIG. FIG. 13 is a diagram showing test results of a noise test on a ground wire. FIG. 2 is a plan view showing a configuration of an illumination unit. 10 is a cross-sectional view taken along line BB of FIG. 9. FIG. 13 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. FIG. 2 is a diagram showing the chromaticity characteristics of a COB type LED. FIG. 11 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. 5A and 5B are diagrams showing measurement results of the reflection characteristics of a reflecting surface according to an embodiment of the present invention. FIG. 4 is a diagram showing a measurement result of the radiation spectrum of a floodlight according to an embodiment of the present invention. FIG. 2 is a perspective view showing a configuration of a reflecting surface according to an embodiment of the present invention. 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. FIG. 13 is an illustration of a concave facet design. 11A and 11B 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.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In this embodiment, a floodlight is illustrated as an example of a lighting device.

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 the walls of buildings 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 FIG. 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. The emission direction of the illumination light can be changed by changing the tilt angle of the fixture body 3.

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 device main body 3 of this embodiment includes a main body case 10 and a power supply case 12, which are separate bodies.

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, and an emission opening 14, which is generally rectangular when viewed from the front and emits illumination light, is open on the front side, and an illumination unit 13 is housed in a position facing the emission opening 14. The illumination unit 13 includes a light source of 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.

A decorative frame 15 is attached to the front of the main case 10, surrounding the emission opening 14. The emission opening 14 is covered by 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 case 10.

As shown in FIG. 2, support attachment pieces 17 are provided on both the left and right sides of the main case 10. As shown in FIG. 1, each support attachment piece 17 extends toward the rear of the main case 10, and the U-shaped support arm 4 is attached so as to be freely rotatable.

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 attachment 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, and a circuit board 19A of the power supply device 19 is 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 ventilation holes opened in the side surfaces 12A.

As shown in FIG. 4, the power supply case 12 is fixed to the back of the main body case 10 with a gap δ between the power supply case 12 and the main body case 10. The power supply case 12 is fixed by 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 material of the screws 24 is appropriate, and in this embodiment, it is stainless steel. As described later, the surfaces of the power supply case 12 and the main body case 10, including the screw holes 25, are surface-treated (insulating paint in this embodiment) to form an insulating layer, and the screw 24 and the screw holes 25 are not electrically connected to each other by screwing them into each other.

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

In this embodiment, the main body case 10 and the power supply case 12 are each aluminum die-cast products, and are formed from an aluminum alloy, which is a type of metal. In addition, 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, so that the entire surface of the base material exposed to the outside is covered with an insulating layer made of an insulating coating film, thereby improving corrosion resistance and insulation.

Next, we will explain the grounding structure of the floodlight 1.

As shown in FIG. 3, a waterproof wire retraction section 42 is provided on the bottom surface 12B of the power supply case 12, which retracts the power supply line 40 that transmits commercial power into the inside. The power supply line 40 includes a ground wire 40A, which is electrically connected to the power supply case 12, thereby grounding the power supply case 12. In this embodiment, a ground terminal (not shown) is erected on the bottom plate 20 inside the power supply case 12, and the power supply case 12 is grounded by connecting the ground wire 40A to the ground terminal.

In addition, as shown in FIG. 4, the device body 3 of this embodiment includes 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.

FIG. 5 is an enlarged view of the area indicated by the arrow X in FIG.
In this embodiment, the ground 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 with the above-mentioned gap δ therebetween, via a wave washer 56.
Specifically, the grounding structure 50 includes a first metal part 52 that is electrically conductive with the main body case 10 and is provided on the rear surface 10A of the main body case 10, a second metal part 54 that is electrically conductive with the power supply case 12 and is provided on the opposing surface 12C of the power supply case 12, and the above-mentioned metallic wave washer 56 that is interposed between the first metal part 52 and the second metal part 54 and is sandwiched between the first metal part 52 and the second metal part 54.

The ground structure 50 of this embodiment further includes a seal portion 57 that seals the entire circumference 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 becoming wet with 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.

FIG. 6 is a perspective view of the floodlight 1 as viewed from the rear side.
A wiring hole 61 is opened in the rear surface 10A of the main body case 10, and wiring 60 drawn from the power supply case 12 is led 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 surrounding 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 a formation region of the first metal portion 52 is masked.

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 placed inside the wall portion 58 on the surface of the first metal portion 52 in a state where it is positioned by the wall portion 58.

A groove 59 having a circular shape in a plan view is formed on the outer periphery of the wall 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 crushed 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 part 52, the second metal part 54, and the wave washer 56).

FIG. 7 is a perspective view of the wave washer 56.
The wavy washer 56 is a metal plate-like member having a circular ring shape in a plan view. The wavy washer 56 includes, within the plane, a plurality of first portions 56A bent in a convex direction relative to the surface of the flat first metal portion 52 and a plurality of second portions 56B bent in a concave direction, 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.

As shown in FIG. 5, the second metal part 54 provided on the power supply case 12 is a part of the opposing surface 12C of the power supply case 12 deformed in a convex shape toward the main body case 10, and is formed in a circular ring shape in a plan view with approximately the same diameter as the first metal part 52. The tip part 54A of the second metal part 54 is masked during surface treatment (insulating coating in this embodiment) like the first metal part 52, exposing the metal base of the power supply case 12, and the tip part 54A presses the metal wave washer 56 toward the first metal part 52, thereby elastically deforming the wave washer 56. In other words, the wave washer 56 is sandwiched between the first metal part 52 and the second metal part 54, each of which has its metal base exposed, by the pressing of the first metal part 52, and the first metal part 52 and the second metal part 54 are electrically connected through the wave washer 56.

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 the gap δ from expanding even if the amount of protrusion of second metal part 54 becomes somewhat larger due to dimensional tolerances of parts, etc., and also prevents the sealing performance of seal part 57 from decreasing due to the expansion 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 conductivity between the first metal part 52 and the second metal part 54 can be reliably established through the wave washer 56.

In addition, in the ground 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 as shown in FIG. 5, a wiring path 62 is formed inside the seal part 57, 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 makes it possible to reduce costs without providing a separate waterproof structure for the wiring 60.

Incidentally, a configuration is also conceivable in which an earth wire for grounding is introduced from the inside of the power supply case 12 through the wiring path 62 into the inside of the main body case 10, and electrical continuity is established between the power supply case 12 and the main body case 10 via 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 results in poor assembly workability and increased manufacturing costs.
In addition, because 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 noise.
In contrast, in the grounding structure 50 of the present embodiment, the power supply case 12 and the main body case 10 are electrically connected using a wave washer 56 rather than an earth wire, which improves assembly workability and does not result in increased costs or noise.

8 is a diagram showing the 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 Special des Perturbations Radioélectriques) for 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, it is found that the noise in that frequency range is suppressed, and a noise suppression effect is achieved.

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 it is necessary to ensure electrical continuity between these parts. For this reason, the above-mentioned wave washer 56 is provided at the engagement parts of both parts, and the bottom plate 20 and cover body 22 are sandwiched between the wave washer 56 to ensure electrical continuity between them. As a result, just like the electrical continuity between the power supply case 12 and the main body case 10, there is no need to connect the bottom plate 20 and cover body 22 with an earth wire, improving the ease of assembly.

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 all need to have a circular ring shape in a 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 portion 52 and the second metal portion 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 paint, and any surface treatment that forms an insulating layer on the surface may be used.

Next, the configuration of the lighting unit 13 will be described in detail.

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 of FIG.
As described above, the illumination unit 13 includes the LEDs 30 as the light source and the reflector 32 as the light control member, and the reflector 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 reflector 32, and the reflector 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 light distribution angle, and as shown in Fig. 9, the exit side opening ends 35 of adjacent reflecting surfaces 34 are arranged so close to each other that they are almost in contact with each other, thereby reducing the planar dimensions of the reflector 32.

The LED 30 in 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 illumination unit 13 is increased.

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

However, if no measures are taken, the shorter the length LA of the reflective surface 34, the more noticeable the unevenness in illuminance and color will be, resulting in a deterioration in lighting quality. In particular, in the case of sign lighting, this can have adverse effects such as changing the color of the display surface of the sign.

To explain the occurrence of illuminance unevenness, if the length LA of the reflecting surface 34, which is long enough 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, the emitted light components that are not parallel to the design optical axis KA increase. For this reason, the light distribution shape in a cross section including the design optical axis KA, as shown in Figure 11, has peaks on both sides of the design optical axis KA, resulting in a so-called "peak crack" shape, and the central luminous intensity (axial luminous intensity) decreases. As a result, illuminance unevenness occurs on the irradiation surface with reduced illuminance in the center.

Next, the occurrence of color unevenness will be explained. The COB type LED used in 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. The blue light and the yellow light from the fluorescence are mixed together 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, and the component containing a large amount of white light is positioned away from the design optical axis KA, causing the above-mentioned peak splitting. As a result, the part of the irradiated surface corresponding to the design optical axis KA appears relatively yellowish.

In addition, generally, the chromaticity of the light emitted from the COB LED of such a configuration changes depending on the radiation angle α with respect to the optical axis KB of the COB LED. Specifically, as shown in FIG. 12, the chromaticity ΔCCY increases as the radiation angle α increases. Considering the white point in the xy chromaticity diagram as a reference, the chromaticity ΔCCY becomes more yellowish as y increases and more reddish as y decreases, so it can be said that the chromaticity ΔCCY becomes more yellowish as ΔCCY increases. Therefore, if the radiation light with a relatively large radiation angle α is blocked so that it is not incident on 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 the case of COB LEDs, the light emission efficiency can be increased by increasing the color deviation (Duv). However, increasing the color deviation (Duv) increases the yellowish color of the emitted light, which causes color unevenness. The color deviation (Duv) is a value that represents the deviation (deviation) from the blackbody radiation locus.
Thus, in the case of COB LEDs, the problem of color unevenness becomes more pronounced as the efficiency increases.

Therefore, the reflecting surface 34 of the present embodiment is configured to be able to increase efficiency even with a short length LA, and to suppress the occurrence of uneven illuminance and color unevenness.
Specifically, the above-mentioned effect is achieved by differentiating the layout of the reflecting surface 34 from the usual 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.

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, is disposed on the LED 30 so that the 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 by a predetermined distance LC (0.5 mm in this embodiment) along the design optical axis KA.
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, and the "peak split" shown in Fig. 11 is eliminated. This maximizes the central luminous intensity (axial luminous intensity), and suppresses the occurrence of uneven illuminance and color unevenness 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.

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 a case in which the reflective film 70 is not provided, and is formed on the entire surface of the reflective surface 34 .
The reflecting surface 34 in this embodiment is formed by forming an undercoat layer of suitable paint (in this embodiment, product name: UV-542 by Toyo Kogyo Paint 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 in this embodiment is made of ADC12, which is an aluminum alloy, but other suitable materials such as pure aluminum or a resin material can also be used for the base material.

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 SiO ₂ (refractive index: 1.46), and the high refractive index material layer 74 is made of TiO ₂ (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, the low refractive index material layer 72 and the high refractive index material layer ₇₄ can be made of 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).
The refractive index listed next to the material name is the value for a wavelength of about 550 nm.

The reflective film 70 having such a configuration changes the peak wavelength in the reflection characteristics 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 nm.

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 reflective 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 reflective surface sample SA2.

FIG. 15 is a diagram showing the measurement results of the radiation spectrum of the projector 1.
The measurement results were obtained by measuring the reflecting surface samples SA3, SA4, and SA5 of the reflecting surface 34 with an illuminance meter at a point 3 meters away from the projector 1. The reflecting surface sample SA3 is the reflecting surface 34 having the reflecting film 70 designed to have a peak wavelength of 300 nm, the reflecting surface sample SA4 is the reflecting surface 34 having the reflecting film 70 designed to have a peak wavelength of 450 nm, and the reflecting surface sample SA5 is the reflecting surface 34 having the reflecting 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.

The measurement results in Figures 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 reflection surface 34 with a reflection 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 reflection surface 34 having such a reflection film 70 as illumination light, it is possible to make yellow color unevenness on the illuminated surface less noticeable.

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 facet 80 is omitted in order to avoid the drawings becoming complicated.
As shown in FIG. 16, the reflecting surface 34 of this embodiment is provided with a series of concave facets 80 without any gaps.

17A and 17B are diagrams showing the configuration of a 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 concave amount Q, and color unevenness can be suppressed by increasing the diffusion. However, since the light distribution angle increases as the diffusion increases, in this embodiment, the concave facet 80 is designed to suppress color unevenness while suppressing the increase in the light distribution angle to about 6 degrees or less.

The design of such a concave facet 80 is as follows:

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 the 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 bottom 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.

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 N+1th 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.

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 reflecting surface 34, which is a paraboloid, is specified, 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 a value (=360/Z) obtained by dividing 360 degrees by the number Z of first concave facets 80-1 formed, and the number Z is arbitrary.
In the 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.

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

In formula (1), the larger the coefficient E, the larger the concave amount Q, which results in greater diffusion and a larger light distribution angle. Therefore, the coefficient E is set within a range in which the light distribution angle does not exceed an 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.

In addition, by determining the width WF and the concave amount Q, two points PF1 and PF2 are determined on the concave facet 80 separated by the WF, 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 passing through each of these points PF1, PF2, and PF4 is specified as the curved surface of the concave facet 80.

Next, the length of the upper side MAU of the paraboloid 85 is determined to be the height HF. This upper side MAU is a side of the paraboloid 85 that extends at a position corresponding to the exit 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.

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.

19 is a diagram showing the results of simulating the chromaticity distribution of the light emitted from the reflecting surface 34 of this embodiment. The simulation in this figure is for determining the chromaticity distribution when the wall surface is irradiated with the light emitted from the reflecting surface 34 in a state where the design optical axis KA is placed on the wall surface. This simulation is performed on the reflecting surface 34 where the predetermined distance LC of the focal point FA from the light emitting surface 36 is about 0.5 mm and the reflecting surface 34 is not provided with the reflective film 70.
As shown in the figure, when the concave facet 80 is not provided on the reflecting surface 34, the difference in color temperature between the vicinity range T of the design optical axis KA and its surroundings is significant, and the color temperature is high in the vicinity range T. It can be seen that such a difference in color temperature between the vicinity 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 increases by approximately 6 degrees, it is understood that the difference in color temperature is mitigated and color unevenness is eliminated.

In this way, although the length LA of the reflective surface 34 in 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 unevenness in illuminance and color.
Furthermore, the reflective 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.

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, the light-emitting surface 36 is circular in plan view with a diameter of 5.5 mm, and the corresponding reflective surface 34 has a length LA of 22.8 mm. In this case, by setting the predetermined distance LC from the light-emitting surface 36 to the focal point FA to 0.5 mm, the peak wavelength in the reflection characteristic of the reflective film 70 to 425 nm, and the dimensions of the first concave facet 80-1, which is the basis for the dimensions of each of the concave facets 80, to the following values, the increase in the light distribution angle is suppressed 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 having a thickness of 100 nm to 200 nm, a low refractive index material layer 72 made of SiO ₂ having a thickness of 60 nm to 70 nm, and a high refractive index material layer 74 made of TiO ₂ having a thickness of 40 nm to 50 nm.

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 in number to the extent that color unevenness and illuminance unevenness do not occur.

This embodiment provides the following advantages:

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

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, electrical connection between the first metal part 52 and the second metal part 54 can be reliably achieved 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.

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 reliably establishing electrical continuity between them by the ground structure 50. In addition, since electrolytic corrosion of the ground structure 50 is prevented, peeling of the insulating layer due to electrolytic corrosion can be prevented.

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 in which the first metal portion 52 and the second metal portion 54 are to be formed during surface treatment (insulating coating in this embodiment).

In this embodiment, the ground structure 50 has a wiring path 62 through which the wiring 60 extending between the main body case 10 and the power supply case 12 passes in the area sealed by the seal portion 57 .
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.

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 of the light-emitting surface 36. The parabolic focal point FA of this reflecting surface 34 is located at a position spaced apart from the light-emitting surface 36 along the design optical axis KA, and a reflecting film 70 that increases the reflectance of blue light is provided on the surface, and multiple concave facets 80 are provided on the surface.

With this configuration, the focal point FA is positioned at a distance along the design optical axis KA from the light-emitting surface 36, 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 further reduces color unevenness while suppressing the spread of the light distribution angle.
As a result, even if the length LA of the reflecting surface 34 is made shorter than the standard, the occurrence of uneven illuminance and color unevenness can be suppressed, and the lighting quality can be improved.
Furthermore, by increasing the color deviation (Duv) of the LED 30 or causing the emitted light of the LED 30 in the range of 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.

In this embodiment, the reflective film 70 has a higher reflectance for light of the complementary color (blue in this embodiment) of the color of the target of the color unevenness than for light of the color of the target 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 cancelled out by the complementary color, thereby suppressing color unevenness.

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 color unevenness can be improved while suppressing the spread of the emitted light.

The above-described embodiment is merely an example of one aspect of the present invention, and any modification or application is possible without departing from the spirit and scope of the present invention.

For example, the present invention is not limited to floodlight 1 and can be applied to lighting fixtures for any purpose.

In the above-described embodiments, the horizontal, vertical, and other directions, various numerical values, shapes, and materials include a range that provides the same effect as those directions, numerical values, shapes, and materials (a so-called equivalent range), unless otherwise specified.

1. Floodlight (lighting equipment)
3 Instrument body 10 Body case (first case)
12 Power supply case (second case)
12C Opposing surface 13 Lighting part 19 Power supply device 20 Bottom plate 22 Cover body 30 LED (light source)
40A Ground wire 50 Ground structure 52 First metal part 54 Second metal part 55 Packing 56 Wave washer (elastic deformation member)
57 Sealing portion 61 Wiring hole 62 Wiring path δ Gap

Claims (3)

a first case containing a light source;
a second case electrically connected to the ground line;
A lighting fixture comprising:
the first case and the second case have wiring holes through which power lines pass;
a ground structure portion that electrically connects the first case and the second case and prevents a wiring path through which the power line passes from being wet ;
On a surface of the first case , a first metal portion having a circular shape in a plan view and surrounding the periphery of the wiring hole , a wall portion having a circular shape in a plan view and surrounding the first metal portion from an outer periphery side, and a groove portion having a circular shape in a plan view recessed on the outer periphery side of the wall portion,
a second metal portion is provided on a surface of the second case as the ground structure, the second metal portion having a ring-shaped region facing the first metal portion and projecting toward the first metal portion ;
a conductive elastic deformation member that is sandwiched between the first metal portion and the second metal portion and elastically deforms is disposed on an inner circumferential side of the wall portion of the first case ,
an annular seal portion that closes a gap between the first case and the second case so as to seal an area including the first metal portion, the second metal portion, and the elastic deformation member is fitted into the groove portion of the first case;
The elastic deformation member is a wave washer having a circular shape in a plan view, and the power line passes through a central hole of the wave washer.
A lighting fixture characterized by: The lighting device according to claim 1 , wherein an insulating layer is formed on the first case and the second case except for the first metal portion and the second metal portion, respectively. the first case and the second case are both made of metal,
The lighting device according to claim 1 or 2, characterized in that the first metal part and the second metal part are both formed by exposing the metal base material of the first case and the second case.

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