Outdoor lighting fixture

Abstract

To provide an outdoor lighting fixture capable of changing an illumination color according to change of an ambient temperature with a simple configuration.SOLUTION: An outdoor lighting fixture comprises a light source part with an LED, and a cover that covers the light source part. A thermochromic material is provided on at least a part of the cover. The thermochromic material becomes decolorized or colored in accordance with a temperature of the thermochromic material. When a third temperature intermediate between a first temperature at which decoloring starts and a second temperature at which coloring starts is defined as TO°C, and a temperature rise of the thermochromic material due to lighting of the light source part is defined as TU°C, the following relation is satisfied: 10<TO-TU<30.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to outdoor lighting fixtures. [Background technology]

[0002] Patent Document 1 discloses an outdoor lighting fixture that has multiple LEDs with different color temperatures, measures the outside temperature, and controls the multiple LEDs to change color depending on the outside temperature, such as displaying daylight white in the hot summer and warm white in the cold winter. Patent Document 2 discloses an automobile headlamp that uses a thermochromic agent in the lens portion of the headlamp, so that when the lamp is turned on, the thermochromic agent is transparent and light can be irradiated to the outside, and when the lamp is turned off, the thermochromic agent is colored and has the color required for the design. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-48966

[0004] [Patent Document 2] Japanese Utility Model Application Publication No. 63-95103 Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Document 1 has a complex configuration, such as detecting the outside temperature and controlling LEDs with different color temperatures depending on the outside temperature. Also, Patent Document 2 only changes the color of the cover when the light source is turned off, but cannot change the color when the light source is turned on. The present invention provides an outdoor lighting fixture that has a simple configuration and can change the color of the light in response to changes in outside air temperature. [Means for solving the problem]

[0006] One aspect of the present invention is an outdoor lighting fixture comprising a light source unit having an LED and a cover that covers the light source unit, wherein a thermochromic material is provided in at least a portion of the cover, and the thermochromic material changes between a decolorized state and a colored state depending on the temperature of the thermochromic material, and where TO°C is a third temperature intermediate between a first temperature at which decolorization begins from the colored state and a second temperature at which coloration begins from the decolorized state, and TU°C is the temperature rise of the thermochromic material when the light source unit is turned on, the outdoor lighting fixture satisfies the following relationship: 10 <TO-TU<30 [Effects of the Invention]

[0007] According to the present invention, it is possible to change the color of illumination in response to changes in outside air temperature with a simple configuration. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view of an outdoor lighting fixture according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2 . [Figure 4] FIG. 4 is a vertical cross-sectional view of the light source unit, schematically showing the cover and the light-emitting element. [Figure 5] FIG. 2 is a diagram showing the emission spectrum of light emitted by an outdoor lighting fixture. [Figure 6] 1 is a graph showing changes in the color temperature of light emitted by an outdoor lighting fixture with respect to the outside temperature. [Figure 7] 10 is a diagram showing the optical characteristics of an outdoor lighting fixture relative to the outside temperature. [Figure 8] FIG. 10 is a vertical cross-sectional view of a light source unit, schematically showing a cover and a light-emitting element according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Outdoor lighting fixture configuration) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of an outdoor lighting fixture 1 according to a first embodiment of the present invention. As shown in FIG. 1, the outdoor lighting fixture 1 is a street light that is mainly used to illuminate parks, squares, sidewalks, and the like. The outdoor lighting fixture 1 has a light source unit 10, a support 50, and a holder unit 16. The light source unit 10 is disposed at the upper end of the outdoor lighting fixture 1 and emits illumination light. The light source unit 10 has an outer shell 11 and a bottom plate 13, and emits illumination light downward from an emission port 13a, which is an opening formed in the bottom plate 13.

[0010] The support 50 is a columnar member that is fixed to a pole or the like extending from the ground via a holder 16 attached to its lower end, and holds the light source unit 10 at its upper end. The support 50 is formed from a hollow aluminum extrusion material, and supplies power from wiring inside the pole or the like to the light source unit 10 via power wiring that passes through the inside of the support 50.

[0011] The holder unit 16 is a member that is fixed with its lower portion inserted into a hollow pole or the like and supports the support column 50. A support plate 16a, which is a plate-like member that extends downward, is fixed to the lower end of the holder unit 16, and the support plate 16a supports a power supply unit 51 and a protection device 53. The power supply unit 51 converts commercial AC power supplied from wiring inside the pole or the like into DC power and supplies it to the light source unit 10. The protection device 53 is equipped with a varistor and is a device that protects the light source unit 10 from surge currents and the like.

[0012] FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1, showing the configuration of the light source unit 10 as viewed from below.

[0013] 2, the light source unit 10 is formed in a circular shape in a plan view. The support pillar 50 is formed in a substantially equilateral triangular shape in a plan view, with each side of the triangle curved toward the center of the light source unit 10. Three light exit ports 13a are formed in the bottom plate 13 of the light source unit 10 so as to follow the three sides of the support pillar 50, and are arranged so that the light emitting elements 15a can be seen from each light exit port 13a when viewed from below.

[0014] The light emitting element 15a is an LED (Light Emitting Diode) that emits illumination light using power supplied from the power supply device 51. In this embodiment, an LED that does not emit ultraviolet light but emits light at a color temperature of 3500 K or higher is used as the light emitting element 15a. Note that the light emitting element 15a may be provided with other light emitting elements such as a laser diode.

[0015] In plan view, the light emitting elements 15a are arranged inside the reflecting mirror 19. The reflecting mirror 19 is formed in a cylindrical shape with a mirrored interior, and reflects the illumination light emitted from the light emitting elements 15a and guides it to the light outlet 13a. All three light outlets 13a are covered by a light-transmitting cover 60. Cover 60 is formed in the shape of a circular flat plate with an opening 61 in the center, and is attached to bottom plate 13. The illumination light emitted from three light outlets 13a passes through cover 60 and is emitted downward. Cover 60 is positioned so that the entire flat surface that serves as the light outlet surface faces the installation surface of outdoor lighting fixture 1.

[0016] Fig. 3 is a cross-sectional view taken along line III-III of Fig. 2. Fig. 3 shows the internal configuration of the light source unit 10. As shown in FIG. 3 , the light source unit 10 has an inner shell 30. The inner shell 30 is a concave member that houses a substrate 15 on which the light emitting element 15a is mounted, and a reflector 19. In this embodiment, the inner shell 30 is made of a metal material. A flange portion 39 is formed at a lower end portion 38 of the inner shell 30 by recessing the side surface of the inner shell 30. The lower end portion 38 of the inner shell 30 is fixed to the support 50, sandwiching the bottom plate 13, by bolts inserted into the flange portion 39. As a result, a light source chamber S2, which is a space partitioned by the inner shell 30, the bottom plate 13, and the cover 60, is formed inside the inner shell 30.

[0017] The light source chamber S2 is connected to the internal space S1 of the support 50 by a communication hole 13b, which is an opening provided in the center of the bottom plate 13, and an opening 61 provided in the center of the cover 60, and the power supply wiring extending from the inside of the pole, etc. is drawn from the internal space S1 of the support 50 into the light source chamber S2 through the communication hole 13b. The light source chamber S2 is configured to be able to communicate with the ventilation space S3 via an opening 35a formed in the upper surface 31 of the inner shell 30.

[0018] Inner peripheral packing 17a and outer peripheral packing 17b are provided between the members forming the light source chamber S2, thereby making the joints between the members airtight. Therefore, the light source chamber S2 communicates with the internal space S1 of the support 50 and the ventilation space S3.

[0019] The inner gasket 17a and the outer gasket 17b are each annular gaskets made of an elastic material such as rubber. The inner gasket 17a is disposed between the inner periphery of the cover 60 and the bottom plate 13. The inner gasket 17a is pressed against the bottom plate 13 from above by the retaining plate 14, thereby closing the joint between the cover 60 and the bottom plate 13 and gripping the inner periphery of the cover 60. The retaining plate 14 is a plate-like member that has through holes that open to overlap the communication holes 13b vertically and is fixed to the bottom plate 13 by fastening members inserted through the through holes. The outer gasket 17b is disposed between the outer periphery of the cover 60, the lower end 38 of the inner shell 30, and the bottom plate 13, closing the respective joints. The outer gasket 17b is sandwiched between the lower end 38 of the inner shell 30 and the bottom plate 13, thereby gripping the outer periphery of the cover 60.

[0020] A support column packing 12 is provided between the support column 50 and the bottom plate 13. The support column packing 12 is made of an elastic material such as rubber, and is a packing that closes the joint between the support column 50 and the bottom plate 13.

[0021] The upper surface 31 of the inner shell 30 is formed to be approximately flat. On the upper surface 31, an enclosing wall 33 and a middle partition wall 37, both of which are protrusions that protrude upward, are formed. The outer shell 11 is fastened to the inner shell 30 so that its inside contacts the upper ends of the enclosing wall 33 and the middle partition wall 37, and a ventilation space S3 is formed between the outer shells 11 and 30. A gap G is formed around the entire periphery between the lower end of the outer shell 11 and the outer periphery of the bottom plate 13, and the ventilation space S3 communicates with the outside of the light source unit 10 via the gap G.

[0022] Gap G is located at approximately the same height as the lower end 38 of the inner shell 30, and is provided below the upper surface 31. The height dimension of gap G is smaller than the thickness of the flange portion 39. The height dimension of gap G is designed so that the area of ​​gap G, expressed as the product of the height dimension and the length of the entire circumference of the lower end of the outer shell 11, is equal to or greater than the area of ​​opening 35a.

[0023] (Configuration related to light source) A plurality of substrates 15 are attached to the inside of the upper surface 31 of the inner shell 30. As shown in Fig. 2, when viewed from below, each of the substrates 15 is arranged such that a mounting surface 15b on which the light emitting elements 15a are mounted faces each of the light outlets 13a, and each of the light emitting elements 15a is located inside the light outlet 13a. As shown in FIG. 3, the inner shell 30 holds the substrate 15 so as to face the cover 60 with the reflecting mirror 19 and the light source chamber S2 in between.

[0024] As a result, both the substrate 15 and the light emitting element 15a are disposed vertically above the cover 60 at a predetermined distance. This prevents the cover 60 from being heated by the heat generated by the substrate 15 and the light-emitting element 15a in the outdoor lighting device 1. In this embodiment, the substrate 15 and the light-emitting element 15a are both arranged at a distance of 1 cm or more from the cover 60 in the vertical direction.

[0025] The substrates 15 are attached such that the entire attachment surface 15c, which is the surface opposite to the mounting surface 15b, abuts against the inside of the upper surface 31 of the inner shell 30. The upper surface 31, the surrounding wall 33, and the partition wall 37 function as a heat sink, thereby cooling the substrates 15. As described above, the upper surface 31, the surrounding wall 33, the partition wall 37, the substrate 15, and the light-emitting element 15a are disposed above the cover 60. This prevents the heat generated by the substrate 15 and the light-emitting element 15a and the heat released from the upper surface 31, the surrounding wall 33, and the partition wall 37 from being directed toward the cover 60 due to thermal convection or the like.

[0026] (Cover 60 configuration) The cover 60 is formed by applying a paint 64 containing a thermochromic material to a globe-shaped substrate 62 made of a resin or glass material (Fig. 4). Thermochromic materials are materials that change color or fade depending on the temperature of the material. However, the cover 60 is not limited to this, and may be formed by kneading a thermochromic material into the base material 62.

[0027] The thermochromic material of this embodiment begins to lose a predetermined color at a temperature equal to or higher than a predetermined temperature, and becomes colorless and transparent when the temperature rises from that temperature to a predetermined value or higher. Furthermore, the thermochromic material begins to take on a predetermined color below a predetermined temperature, and when the temperature drops from that temperature to a predetermined value or below, it is colored to the predetermined color with a transparency that allows the light emitted by the light-emitting element 15a to pass through. In the following description, the state in which the thermochromic material and cover 60 are colorless and transparent is referred to as the decolorized state. Also, the state in which the thermochromic material and cover 60 have completely changed color and are colored to a predetermined color is referred to as the colored state.

[0028] The cover 60 of this embodiment is colored in a color such that, in the colored state, the color temperature of light transmitted through the cover 60 is less than 3500 K. Specifically, the cover 60 of this embodiment turns orange when the temperature drops. The thermochromic material of this embodiment is formed so that the temperature at which it starts to fade from a colored state is lower than the temperature at which it starts to color from a faded state.

[0029] In this embodiment, the temperature at which the thermochromic material starts to change from a colored state to a discolored state is defined as a first temperature T1 (°C), and the temperature at which the thermochromic material starts to change from a discolored state to a colored state is defined as a second temperature T2 (°C). If the intermediate temperature between the first temperature T1 and the second temperature T2 is defined as a third temperature TO (°C), and the temperature of the thermochromic material that rises due to heat generated when the light source unit 10 is turned on is defined as an increased temperature TU (°C), the outdoor lighting device 1 uses a thermochromic material that satisfies the following formula (1): 10 <TO―TU<30 (1) For a thermochromic material and cover 60 that satisfy the above formula (1), TO-TU is in the range of 10°C to 30°C, so when the light source unit 10 is turned on and the outside air temperature is at a predetermined temperature between 10°C and 30°C, the thermochromic material switches between its colored state and its decolored state.

[0030] As a result, when the outside temperature is low, such as in winter, at 10°C or below, the thermochromic material of the outdoor lighting fixture 1 becomes colored, and the outdoor lighting fixture 1 emits light with a color temperature of less than 3500K. As a result, the outdoor lighting fixture 1 can illuminate a specific outdoor location with a color that is visually warm to pedestrians, and can produce color rendering that gives pedestrians a psychological sense of warmth. On the other hand, when the outside temperature is high, such as in summer, and exceeds 30°C, the thermochromic material is in a discolored state, and the outdoor lighting fixture 1 emits light with a color temperature of 3500K or higher. As a result, the outdoor lighting fixture 1 can illuminate a specific outdoor location with a color that appears cool to pedestrians, and can produce color rendering that gives pedestrians a psychological sense of coolness.

[0031] In this way, by including the cover 60 made of a thermochromic material, the outdoor lighting fixture 1 can adjust the color of the light in response to changes in the outside temperature, regardless of the input of power, etc. In other words, the outdoor lighting fixture 1 can adjust the color of the irradiated light with a simpler configuration.

[0032] The third temperature T can be set to various temperatures by selecting various thermochromic materials. Therefore, in the outdoor lighting device 1, any thermochromic material that will produce the third temperature T that satisfies the above formula (1) can be selected according to the rising temperature T.

[0033] In this embodiment, the temperature rise TU is in the range of 5° C. to 20° C. in accordance with the structure of the light source unit 10 and the power input to the light emitting element 15a. The amount of power input to the light emitting element 15a in this embodiment is 30 W. In the outdoor lighting device 1, by providing the light source unit 10 with the structure described above, it is possible to suppress an increase in the temperature rise TU, and it becomes easy to select a thermochromic material that satisfies the above formula (1).

[0034] In the outdoor lighting fixture 1, the temperature rise TU varies depending on the power input to the light emitting element 15a, the distance between the light emitting element 15a and the cover 60, the base material 62 of the cover 60, and the like. Furthermore, in the outdoor lighting fixture 1, the temperature rise TU may vary at different parts of the cover 60 depending on the positions of the light-emitting element 15a and the cover 60. In this case, the coloring state of the thermochromic material may differ at different positions on the cover 60, which may result in color unevenness. For this reason, it is preferable that the temperature rise TU of the thermochromic material be uniform throughout the entire cover 60.

[0035] 4 is a vertical cross-sectional view of the light source unit, which schematically shows the cover 60 and the light emitting element 15a. In FIG. 4, the cover 60 and the substrate 15 are shown cut along a plane parallel to the vertical direction. 4, of the light emitted from the light emitting element 15a, light L1 that is emitted perpendicularly downward in the vertical direction and light L2 that is reflected by the reflecting mirror 19 and goes downward become parallel to each other. Therefore, the light L1 and L2 are incident on the plane of the cover 60 approximately perpendicularly before being emitted from the light source unit 10. As a result, the optical path length D1 when each of the light L1 and L2 passes through the cover 60 is approximately the same as the thickness dimension of the cover 60.

[0036] In contrast, light L3 emitted from light emitting element 15a that is not reflected by reflecting mirror 19 and that is obliquely incident on the plane of cover 60 has an optical path length D2 when transmitted through cover 60 that is longer than D1. When a thermochromic material is kneaded into the cover 60, differences in the optical path length cause differences in the characteristics of the irradiated light. In the light source section 10 of this embodiment, the light emitting element 15a and the cover 60 are arranged so that the length dimension of the optical path length D2 is equal to or less than twice the length dimension of the optical path length D1. This reduces variations in the optical path length of the light emitted from the light emitting element 15a in the cover 60 of the outdoor lighting fixture 1. Therefore, in the case where a thermochromic material is kneaded into the cover 60, uneven coloring or decoloring of the cover 60 is reduced in the outdoor lighting fixture 1 when the light source unit 10 is turned on.

[0037] In the cover 60, a UV cut section 66 is provided on the entire flat surface located on the outside of the light source section 10. The UV cut section 66 is formed by attaching a UV cut filter to the entire flat surface of the cover 60 located on the outside of the light source section 10. As described above, the cover 60 is provided on the bottom surface of the light source unit 10 that is disposed opposite the installation surface of the outdoor lighting fixture 1, and is covered from above by the outer shell 11. In other words, the cover 60 is provided facing downward. This prevents direct sunlight from being irradiated onto the cover 60 and also prevents ultraviolet light from entering the cover 60. As a result, in the outdoor lighting device 1, deterioration of the thermochromic material provided in the cover 60 is prevented.

[0038] Thermochromic materials are generally susceptible to ultraviolet rays, and when exposed to strong ultraviolet rays such as direct sunlight, they may be altered and their light transmittance may decrease. Therefore, as described above, in outdoor lighting device 1, by providing a UV-cutting portion on cover 60 or by arranging cover 60 facing downward, the thermochromic material is prevented from being exposed to ultraviolet rays, and thus its alteration can be suppressed. The UV cut section 66 is not limited to a UV cut filter, and may be made of UV cut paint.

[0039] (Color matching experiment for outdoor lighting fixtures) Next, an experiment conducted by the inventors will be described. The inventors applied a thermochromic material to the outer surface of the daylight white cover 60 and evaluated the change in color of the outdoor lighting device 1 in response to changes in the outside air temperature.

[0040] In this experiment, a material formed from a leuco dye and a color developer was used as the thermochromic material. This material was orange in the colored state, and the first temperature at which it started to fade from the colored state was 25°C, and the second temperature at which it started to color from the faded state was 35°C. A third temperature TO, intermediate between the first and second temperatures, was 30°C. At this temperature, the thermochromic material had a color approximately halfway between the colored state and the faded state. Furthermore, the temperature rise TU to which the thermochromic material rose when the light source unit 10 was turned on was 10°C. In other words, the thermochromic material in this experiment was formed to have a color approximately halfway between the colored state and the faded state when the outside temperature was 20°C. The inventors set 10°C as a low outdoor temperature and 30°C as a high outdoor temperature, and evaluated the light emitted by outdoor lighting device 1 at each temperature.

[0041] Fig. 5 is a diagram showing the emission spectrum of light emitted from an outdoor lighting fixture. In Fig. 5, the horizontal axis X represents wavelength (nm) and the vertical axis Y represents relative intensity. In Fig. 5, the emission spectrum at an outdoor temperature of 30°C is shown by a solid line, and the emission spectrum at an outdoor temperature of 15°C is shown by a dashed line. 5, when the outside temperature is 30°C, the thermochromic material is in a decolorized state and the light from the light source unit 10 is emitted as is. Therefore, when the outside temperature is 30°C, the outdoor lighting device 1 emits light of 3921 K, which is approximately the same color temperature as the light from the light source unit 10. On the other hand, when the outside temperature is 10°C, the thermochromic material turns orange, and light with wavelengths of 400 to 570 nm is absorbed by the light source unit 10. The color temperature of the light emitted from the outdoor lighting fixture 1 was 2004K.

[0042] Fig. 6 is a diagram showing changes in the color temperature of the light emitted by the outdoor lighting fixture 1 with respect to the outside air temperature. In Fig. 6, the horizontal axis X represents the outside air temperature (°C), and the vertical axis Y represents the color temperature (K). As shown in Figure 6, when the outside temperature was 10°C, the color temperature of the light emitted by outdoor lighting fixture 1 was approximately 2000K. When the outside temperature was 30°C, the color temperature of the light emitted by outdoor lighting fixture 1 was approximately 4000K.

[0043] 7 is a diagram showing the optical characteristics of the outdoor lighting fixture 1 relative to the outside temperature. In Fig. 7, the horizontal axis X represents the outside temperature (°C), and the vertical axis Y represents the relative illuminance (%). As shown in Figure 7, when the outside temperature is 10°C, the relative illuminance of the outdoor lighting fixture 1 is approximately 35% lower than when the outside temperature is 30°C. In other words, it was discovered that the outdoor lighting fixture 1 has a relatively lower illuminance because the light from the light source unit 10 is absorbed as the thermochromic material is colored.

[0044] (Other embodiments) The first embodiment described above merely shows one aspect of the present invention, and any modifications and applications are possible without departing from the spirit of the present invention.

[0045] 8 is a vertical cross-sectional view of the light source unit 10 according to the modified example, which diagrammatically shows the cover 160 and the light emitting element 15a. In FIG. 8, the reflecting mirror 19 is omitted. In the outdoor lighting fixture 1 described above, the cover 60 has a flat outer surface, but this is not limiting, and the cover 60 may have another shape, such as a lens shape. As shown in FIG. 8, in outdoor lighting fixture 1, instead of cover 60, cover 160 may be provided on a predetermined location on the outer surface, with lens portion 168 having an outwardly convex shape. The cover 160 may be provided with a thermochromic material layer 164 in which the thermochromic material is not kneaded into the interior but is applied to the outer surface.

[0046] In this outdoor lighting fixture 1, the thermochromic material layer 164 is provided at any point on the outer surface of the cover 160, and has a substantially uniform thickness D3. As a result, in the outdoor lighting fixture 1, regardless of the angle at which light, such as light L3 and L4, enters the cover 160, the light path length D3 is approximately the same when it passes through the thermochromic material layer 164. Therefore, in the outdoor lighting fixture 1, when the light source unit 10 is turned on, uneven coloring or decoloring of the cover 60 is suppressed. In the outdoor lighting device 1, the cover 60 described above may be provided with a UV cut-off portion 66 that is applied to the outer surface, similar to the cover 160.

[0047] Unless otherwise specified, the horizontal, vertical, and other directions, various numerical values, and shapes in the above-described embodiments include a so-called equivalent range that provides the same action and effect as those directions, numerical values, and shapes.

[0048] [Configuration supported by the above embodiment] The above embodiment supports the following configurations.

[0049] (Configuration 1) An outdoor lighting fixture comprising a light source unit having an LED and a cover that covers the light source unit, wherein a thermochromic material is provided in at least a portion of the cover, and the thermochromic material changes to a decolorized or colored state according to the temperature of the thermochromic material, and where TO°C is a third temperature intermediate between a first temperature at which decolorization begins from the colored state and a second temperature at which coloration begins from the decolorized state, and TU°C is the temperature rise of the thermochromic material due to the light source unit being turned on, the outdoor lighting fixture satisfies the following relationship: 10 <TO―TU<30 This allows the outdoor lighting fixture to adjust the color of the emitted light in response to changes in outside temperature with a simpler configuration.

[0050] (Configuration 2) The outdoor lighting fixture according to Configuration 1, wherein the thermochromic material is applied or printed on the outer surface of the cover. This allows the outdoor lighting fixture to adjust the color of the emitted light in response to changes in outside temperature with a simpler configuration.

[0051] (Configuration 3) The outdoor lighting fixture according to Configuration 1, wherein the thermochromic material is kneaded into the cover. This allows the outdoor lighting fixture to adjust the color of the emitted light in response to changes in outside temperature with a simpler configuration.

[0052] (Configuration 4) The outdoor lighting fixture according to any one of Configurations 1 to 3, further comprising a UV-cutting portion on the outer surface of the cover. This prevents ultraviolet light from entering the cover, which in turn prevents deterioration of the thermochromic material of the cover in outdoor lighting fixtures.

[0053] (Configuration 5) The outdoor lighting fixture according to Configuration 4, wherein the UV-cutting portion is a coating of a UV-cutting agent or a UV-cutting film. This prevents ultraviolet light from entering the cover, which in turn prevents deterioration of the thermochromic material of the cover in outdoor lighting fixtures.

[0054] (Configuration 6) The outdoor lighting fixture according to any one of Configurations 1 to 5, wherein the cover is provided in a position where direct sunlight does not enter. This prevents direct sunlight from reaching the cover, which in outdoor lighting fixtures prevents the thermochromic material of the cover from deteriorating.

[0055] (Configuration 7) The outdoor lighting fixture according to any one of Configurations 1 to 6, wherein the cover is spaced at least 1 cm from the light source unit. This prevents heat from the light source from being directed toward the cover in an outdoor lighting fixture.

[0056] (Configuration 8) The outdoor lighting fixture according to any one of Configurations 1 to 7, wherein when the thermochromic material is in a decolorized state, the color temperature of the light irradiated to the outside is 3500 K or higher, and when the thermochromic material is in a colored state, the color temperature of the light irradiated to the outside is less than 3500 K. This allows the outdoor lighting fixture 1 to adjust the color of the emitted light to a color temperature that is comfortable for pedestrians, depending on the outside temperature. [Explanation of symbols]

[0057] 1. Outdoor lighting fixtures 10 Light source section 15 PCB 15a Light-emitting element 60, 160 cover 66 UV cut section 160 Cover 164 Thermochromic material layer TO 3rd temperature TU Temperature Rise

Claims

1. a light source unit having an LED; a cover that covers the light source unit; An outdoor lighting fixture comprising: At least a portion of the cover is provided with a thermochromic material; the thermochromic material is in a decolorized state or a colored state according to the temperature of the thermochromic material; a first temperature at which decolorization starts from a colored state; a second temperature at which coloring starts from a decolorized state; The third temperature between the above is TO°C, When the temperature rise of the thermochromic material due to the lighting of the light source unit is TU°C, the following relationship is satisfied: Outdoor lighting fixtures. 10<TO-TU<30

2. The thermochromic material is applied or printed on the outer surface of the cover.

10. The outdoor lighting fixture of claim 1.

3. The thermochromic material is kneaded into the cover.

10. The outdoor lighting fixture of claim 1.

4. A UV cut portion is provided on the outer surface of the cover. The outdoor lighting fixture according to any one of claims 1 to 3.

5. The UV cut portion is a coating of a UV cut agent or a UV cut film.

5. The outdoor lighting fixture of claim 4.

6. The cover is provided at a position where direct sunlight does not enter. The outdoor lighting fixture according to any one of claims 1 to 3.

7. The cover is spaced at least 1 cm from the light source unit. The outdoor lighting fixture according to any one of claims 1 to 3.

8. When the thermochromic material is in a bleached state, The color temperature of the light irradiated to the outside is 3500K or higher, When the thermochromic material is in a colored state, The color temperature of the light emitted to the outside is less than 3500K. The outdoor lighting fixture according to any one of claims 1 to 3.

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