Luminaire

Abstract

To provide a luminaire which can perform plasma processing on the air efficiently along a natural flow of the air, and which does not only function as the luminaire but also can sterilize or deodorize the peripheral air.SOLUTION: A luminaire 100 includes: a plasma generation part 10 which includes a lighting element 31, at least one of a hood 33 and a reflection plate 32, and a dielectric layer and a pair of electrode layers provided on both sides of the dielectric layer, and which generates plasma; and a power source part for applying an AC voltage on the pair of electrode layers. In the luminaire 100, the plasma generation part 10 is installed in the periphery of the lighting element 31.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a lighting device equipped with a plasma treatment device that performs plasma treatment on air. [Background technology]

[0002] In recent years, the outbreak of the COVID-19 pandemic has led to a surge of interest worldwide in defense measures against viruses and bacteria. Against this backdrop, plasma processing is being developed as a new defense against viruses and bacteria. Regarding plasma processing technology, a method called Dielectric Barrier Discharge (DBD) has been developed in recent years, making it possible to generate low-temperature plasma at atmospheric pressure.

[0003] When gases containing oxygen and moisture, such as air, are treated with plasma, they generate reactive species (ROS), such as singlet oxygen, hydrogen peroxide, OH radicals, peroxide radicals, and ozone. These reactive species can decompose, kill, or inactivate microorganisms through oxidation reactions and other processes. Examples of microorganisms include various viruses, bacteria, and mold. The reactive species can also decompose chemical substances through oxidation reactions and other processes. Therefore, plasma treatment can be used not only for sterilization but also for deodorization and other purposes.

[0004] Various plasma processing apparatuses have been developed to perform continuous plasma processing while flowing air. For example, Patent Document 1 discloses a plasma generating apparatus in which two or more plasma generating units are stacked, each of which has a flat first electrode and a flat second electrode facing each other across a gap. Patent Document 2 also discloses an air purifier that includes a plasma generator having a structure in which electrode members, at least a portion of which is covered with a dielectric, are arranged in the thickness direction and generate plasma in the gap between adjacent electrode members, a power source that applies voltage, and a blower that blows air through the gap and releases the generated ozone along with the air. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-190472 [Patent Document 2] Japanese Patent Application Publication No. 2018-130208 Summary of the Invention [Problem to be solved by the invention]

[0006] In both the plasma generator described in Patent Document 1 and the air purifier described in Patent Document 2, the air must be forced to pass through a plurality of narrow slit-shaped spaces in order to perform plasma treatment on the air. In other words, it was difficult for either device to perform efficient plasma treatment along the air flow without significantly fluctuating the air flow.

[0007] In our daily lives, sterilization and deodorization functions are required in various aspects of our living environment. Therefore, it would be extremely useful to incorporate plasma processing equipment into everyday products, such as lighting fixtures. Here, "sterilization" is used in a broad sense to include not only the elimination of microorganisms but also "inactivation," which stops or reduces the activity of microorganisms (the same applies below).

[0008] The present invention has been made in view of the above-mentioned circumstances, and aims to provide a lighting device that incorporates a plasma treatment device into the lighting device, thereby enabling efficient plasma treatment of air in accordance with the natural flow of air, and that not only functions as a lighting device but also sterilizes or deodorizes the surrounding air. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the present invention has the following configuration. (1) A lighting device comprising: a lighting element; at least one of a hood and a reflector; a plasma generating unit having a dielectric layer and a pair of electrode layers provided on both sides of the dielectric layer, which generates plasma; and a power supply unit applying an AC voltage to the pair of electrode layers, wherein the plasma generating unit is installed around the lighting element. (2) The lighting device according to (1), wherein the electrode layer has a through-hole penetrating in the thickness direction. (3) The lighting device according to (1) or (2), further comprising a discharge section for discharging the air plasma-treated by the plasma generating section into an external space. (4) The lighting device described in (1) or (2), characterized in that the air plasma-treated in the plasma generating unit is released into the external space by air convection generated by the heat generated by the lighting element. (5) The lighting device according to (1) or (2), further comprising a blower for discharging the air plasma-treated by the plasma generating unit to an external space. (6) The lighting device according to (1) or (2), wherein the plasma generating section is flexible. [Effects of the Invention]

[0010] The lighting device of the present invention is capable of efficiently plasma treating air in accordance with the natural flow of the air, and not only functions as a lighting device but also sterilizes or deodorizes the surrounding air. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view for explaining a plasma generating unit. [Figure 2] FIG. 2 is a perspective view for explaining a plasma generating unit. [Figure 3] FIG. 2 is a cross-sectional view illustrating a plasma generating unit. [Figure 4] FIG. 10 is a perspective view for explaining a plasma generating unit according to a first modified example. [Figure 5] FIG. 10 is a perspective view for explaining a plasma generating unit according to a second modified example. [Figure 6] FIG. 10 is a perspective view for explaining a plasma generating unit according to a third modified example. [Figure 7] FIG. 10 is a cross-sectional view illustrating a plasma generating unit according to a fourth modified example. [Figure 8] FIG. 10 is a cross-sectional view illustrating a plasma generating unit according to a fifth modified example. [Figure 9] FIG. 13 is a cross-sectional view illustrating a plasma generating unit according to a sixth modified example. [Figure 10] 1 is a perspective view showing an illumination device according to a first embodiment. [Figure 11] FIG. 1 is a side view showing an illumination device according to a first embodiment. [Figure 12] FIG. 2 is an enlarged perspective view showing a part of the lighting device according to the first embodiment. [Figure 13] FIG. 2 is an enlarged perspective view showing a part of the lighting device according to the first embodiment. [Figure 14] FIG. 2 is a schematic cross-sectional view of the vicinity of a plasma generating unit according to the first embodiment. [Figure 15] FIG. 10 is a schematic cross-sectional view of a first modified example of the vicinity of the plasma generating unit of the first embodiment. [Figure 16]FIG. 10 is a schematic cross-sectional view of a second modified example of the vicinity of the plasma generating unit of the first embodiment. [Figure 17] FIG. 10 is a perspective view showing an illumination device according to a second embodiment. [Figure 18] FIG. 10 is an enlarged perspective view showing a part of an illumination device according to a second embodiment. [Figure 19] FIG. 10 is a schematic side view showing an illumination device according to a second embodiment. [Figure 20] FIG. 10 is a perspective view showing an illumination device according to a third embodiment. [Figure 21] FIG. 10 is an enlarged perspective view showing a part of an illumination device according to a third embodiment. [Figure 22] FIG. 10 is a semi-transparent side view of a portion of an illumination device according to a third embodiment. [Figure 23] FIG. 10 is a semi-transparent side view showing a modified example of a part of the lighting device according to the third embodiment. [Figure 24] FIG. 10 is a plan view for explaining a plasma generating section of an illumination device according to a third embodiment. [Figure 25] FIG. 10 is a cross-sectional view illustrating a plasma generating unit of a lighting device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail, but the embodiments of the present invention are not limited to the embodiments described below. Each embodiment and modified example can be applied in appropriate combination. Furthermore, directions such as "upper" and "lower" in the description are used for convenience of explanation and do not limit the directions of the present invention.

[0013] The lighting device of this embodiment includes a lighting element, a hood, and / or a reflector, as well as a plasma generating unit and a power supply unit. The plasma generating unit of this embodiment has a dielectric layer and a pair of electrode layers provided on both sides of the dielectric layer. Mask layers may be provided on the opposite sides (outsides) of the pair of electrode layers from the dielectric layer. The power supply unit can apply an AC voltage to the pair of electrode layers. In dielectric barrier discharge, a dielectric layer is provided between two electrode layers, and an AC voltage is applied between the two electrode layers, thereby generating plasma in the dielectric layer sandwiched between the two electrode layers. First, the plasma generating unit will be described.

[0014] <Basic structure of the plasma generation unit> As shown in Figures 1 and 2, the plasma generating unit 10 includes a dielectric layer 11, an upper electrode 12, a lower electrode 13, an upper mask layer 14, and a lower mask layer 15. The plasma generating unit 10 is preferably a thin-film member that is flexible. For convenience, the dielectric layer 11 is expressed as a single dielectric, but it may also be a laminate of one or more dielectrics containing air. The mask layer is provided to protect the electrodes and improve the ease of assembly of the electrodes, and may be omitted. Furthermore, by appropriately selecting the thickness and position of the mask layer, excessive electric field concentration on the electrodes can be prevented, thereby extending the life of the electrodes.

[0015] As shown in FIGS. 1 to 3, the dielectric layer 11 is a layer member disposed between the upper electrode 12 and the lower electrode 13. The material of the dielectric layer 11 is preferably an insulating material with a large breakdown voltage so that discharge does not easily occur between the upper electrode 12 and the lower electrode 13. Furthermore, since the material of the dielectric layer 11 will be exposed to the generated plasma, it is preferably a material that is durable against active substances generated in the plasma. The material of the dielectric layer 11 is preferably a material selected mainly from glass, ceramics, and synthetic resins. The term "mainly" means that the component composition is 50% by mass or more (the same applies hereinafter).

[0016] Examples of glass include soda-lime glass (soda glass), borosilicate glass, quartz glass, lead glass, and oxide glass. Examples of ceramics include alumina, silica, titanium oxide, zinc oxide, and mica (layered silicate). Synthetic resins include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include general-purpose resins such as polyolefin, polystyrene, polyvinyl acetate, polyurethane, polylactic acid, ABS resin, AS resin, acrylic resin, polyvinyl chloride, and polyvinylidene chloride; engineering plastics such as polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyester, and cyclic polyolefin; super-engineering plastics such as polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, liquid crystal polymer, polyetheretherketone, polyimide, polyamideimide, and polyetherimide; and fluorine-based resins. Examples of thermosetting resins include phenolic resin, melamine resin, urea resin, alkyd resin, epoxy resin, unsaturated polyester resin, and polyurethane resin. Among these synthetic resins, silicone-based resins, polyimide-based resins, and Teflon®-based resins, which are highly durable, are particularly preferred. The thickness of the dielectric layer 11 is not particularly limited, but is preferably 0.01 mm to 5.0 mm, more preferably 0.1 mm to 3.0 mm, and even more preferably 0.1 to 1.0 mm, in order to achieve light weight and compactness.

[0017] As shown in FIGS. 2 and 3, the upper electrode (electrode layer) 12 and the lower electrode (electrode layer) 13 are layer members disposed on the front and back of the dielectric layer 11. The upper electrode 12 and the lower electrode 13 are each provided with a through-hole 16 penetrating in the thickness direction. In this embodiment, the through-holes 16 are oval in shape, and five through-holes 16 are formed, but the shape and number are not limited. The through-holes 16 may be omitted, but the presence of the through-holes 16 in this embodiment makes it easier to generate plasma and facilitates the creation of a power supply circuit. Furthermore, contact with gas at the through-holes 16 enables plasma processing of the gas.

[0018] Upper-layer electrode 12 and lower-layer electrode 13 are formed of a conductive material, and may be a metal plate (including metal foil), conductive paint, conductive polymer, conductive film, etc. There are no particular limitations on the thickness of upper-layer electrode 12 and lower-layer electrode 13, but in order to provide a flexible, lightweight, and compact processing device, the thickness is preferably 5 μm to 1.0 mm, more preferably 5 μm to 0.2 mm, and even more preferably 5 μm to 0.1 mm, respectively.

[0019] The dielectric layer 11, the upper electrode 12, and the lower electrode 13 may be laminated without using an adhesive, or may be bonded with an adhesive. The adhesive is preferably a material that is durable against active substances generated in plasma. Examples of adhesives include epoxy, acrylic, urethane, phenol, urea, silicone, cyanoacrylate, rubber, and vinyl acetate adhesives. Among these, silicone adhesives, UV-curable epoxy adhesives, polyamide adhesives, and polyimide adhesives are preferred from the standpoint of durability, with silicone adhesives being more preferred. The thickness of the adhesive is preferably 0.01 to 0.2 mm, and more preferably 0.01 to 0.1 mm.

[0020] As shown in FIG. 3, the upper mask layer (mask layer) 14 and the lower mask layer (mask layer) 15 are members respectively disposed on the outside of the upper electrode 12 and the lower electrode 13. More specifically, the upper mask layer 14 is disposed on the upper surface of the upper electrode 12. The lower mask layer 15 is disposed on the lower surface of the lower electrode 13. The upper mask layer 14 and the lower mask layer 15 are each provided with a through hole 17. In this embodiment, the through holes 17 are oval in shape, and five through holes 17 are formed, but the shape and number are not limited. The through holes 17 may be omitted.

[0021] 2 and 3, through holes 17 have the same shape as through holes 16 and are connected to each other, but they do not necessarily have to be the same shape. Through through holes 16 and 17, dielectric layer 11 is exposed to the outside. In other words, the surface of dielectric layer 11 is exposed to the outside at multiple locations where through holes 16 and 17 are formed. In addition, hole walls (cross-sectional portions) 16a and 17a of through holes 16 and 17 are also exposed to the outside. When an AC voltage is applied between the upper electrode 12 and the lower electrode 13 sandwiching the dielectric layer 11, plasma is generated within the dielectric layer 11. Furthermore, plasma is also generated near the cross-sections 16a of the electrode layer within the through-holes 16 and 17. When an AC voltage is applied between the two electrode layers, plasma is generally generated more easily from the protruding edges of the electrode layers than from the flat portions of the electrode layers. Therefore, in Figures 2 and 3, more plasma is generated near the cross-sections 16a of the electrode layers within the through-holes 16 and 17 than inside the dielectric layer 11 between the two electrode layers. As a result, providing the through-holes 16 and 17 in the plasma generation unit 10 enables more effective plasma generation. Furthermore, when a mask layer is formed using a liquid resin or the like, the mask layer penetrates into areas without electrodes and directly covers the dielectric. However, in areas where the dielectric is exposed, as in this case, the material constituting the mask layer functions as part of the dielectric. At the same time, it can also be used to protect the dielectric layer.

[0022] The upper mask layer 14 and the lower mask layer 15 are formed of an insulating material. The material for forming the mask layers is similar to that of the dielectric layer 11, and is preferably a material selected from glass, ceramics, and synthetic resins. However, to accommodate complex shapes such as those in this embodiment, a flexible material is preferable. Furthermore, the hardness of the upper mask layer 14 and the lower mask layer 15 is preferably equal to or less than that of the upper electrode 12 and the lower electrode 13. While the plasma generation unit 10 can be difficult to handle if it is made of a thin material, providing the upper mask layer 14 and the lower mask layer 15 improves ease of handling. Furthermore, the upper mask layer 14 and the lower mask layer 15 protect the thin conductor from mechanical and physical shocks during manufacturing and use, as well as deterioration caused by the surrounding environment. They also provide mechanical protection against scratches that may occur during manufacturing. On the other hand, when considering that the plasma generating unit 10 will be installed on an object to be attached, it is preferable that the upper mask layer 14 and the lower mask layer 15 have a hardness that allows them to be easily installed along the object to be attached and also improves handling. Furthermore, by dividing the dielectric layer 11 into two, the upper and lower structures of the plasma generating unit 10 can be made symmetrical. Manufacturing can be easily achieved by assembling the upper and lower structures and bonding them together in the center. In this case, the dielectric layer 11 is divided into three layers: the upper layer, the lower layer, and the adhesive layer, but is electrically considered to be a single dielectric. The thicknesses of the upper mask layer 14 and the lower mask layer 15 are not particularly limited, but in order to provide a flexible, lightweight, and compact processing device, they are preferably 5 μm to 1.0 mm, more preferably 5 μm to 0.2 mm, and even more preferably 5 μm to 0.1 mm. The thicknesses of the upper mask layer 14 and the lower mask layer 15 may be set as appropriate, but in this embodiment they are formed to be larger than the thicknesses of the upper-layer electrode 12 and the lower-layer electrode 13.

[0023] The plasma generating unit 10 can be made very thin and flexible, which can lead to problems such as difficulty in handling during assembly. Furthermore, the upper electrode 12 and the lower electrode 13 are formed of conductive materials, such as conductive metals or conductive dielectrics. However, metals, for example, can be corroded by liquids or gases. Furthermore, the upper electrode 12 and the lower electrode 13 are oxidized by highly oxidizing gases and corroded by sulfuric acid or hydrochloric acid. Furthermore, if the upper electrode 12 and the lower electrode 13 are made of a resin-based conductive material, they may be deteriorated by humidity or acid. Furthermore, the plasma generating unit 10 is designed to be installed according to the shape of the object to which it is to be attached. However, if only the upper electrode 12 and the lower electrode 13 are used without the upper mask layer 14 and the lower mask layer 15, problems such as wrinkles in the metal constituting the electrodes or gaps between the electrodes and the dielectric layer 11 can occur if the electrodes are made of thin metal. If gaps are formed between the upper layer electrode 12 and the lower layer electrode 13 and the dielectric layer 11, this can cause abnormal discharge or partial discharge. In this regard, according to this embodiment, the upper mask layer 14 and the lower mask layer 15 can protect the upper electrode 12 and the lower electrode 13, and the plasma generating unit 10 can be easily handled, improving workability and assembly. Furthermore, the provision of the upper mask layer 14 and the lower mask layer 15 allows installation on an object without forming wrinkles or gaps. Furthermore, when multiple pairs of electrodes are provided to form a multi-stage structure, the upper mask layer 14 and the lower mask layer 15 also serve as part of the dielectric that constitutes the barrier discharge, making it less likely that abnormal discharge will occur even if gaps are formed during installation. Depending on the situation, the same effect can be achieved with either the upper or lower mask layer.

[0024] The outer edges of upper-layer electrode 12 and lower-layer electrode 13 may be sealed with an insulator (not shown) to prevent deterioration over time due to exposure to the outside world and to prevent discharge from occurring through the outer edges other than through-hole 16. When a synthetic resin or the like is used as the mask layer, this effect is achieved because it thinly extends to the outer edges of dielectric layer 11 in addition to the outer edges of upper-layer electrode 12 and lower-layer electrode 13. Similarly, the outer edges of the upper mask layer 14 and the lower mask layer 15 may be sealed with an insulator (not shown) to prevent their outer edges from being exposed to the outside world and reacting with external substances to deteriorate over time, and to prevent discharge from occurring through the outer edges other than the through holes 17.

[0025] When the longitudinal direction of the through holes 16, 17 is parallel to the gas flow direction, the resistance to the gas flow is small and the gas flows smoothly. On the other hand, when the longitudinal direction of the through holes 16, 17 is perpendicular to the gas flow direction, the resistance to the gas flow is large, the gas flow is disturbed, and the gas is agitated.

[0026] The shape, number, and orientation of the through-holes 16 and 17 relative to the gas flow can be selected appropriately depending on the purpose of the plasma processing, the effect of the plasma processing, and other factors. The through-holes may have different shapes on the front and back sides of the plasma generating unit 10. Alternatively, through-holes may be provided on the front side of the plasma generating unit 10, while no through-holes are provided on the back side. Although the through-holes are shown as oval in this example, this shape is not required. Round, elliptical, rectangular, triangular, and other shapes are also acceptable. However, shapes with sharp corners tend to concentrate the electric field, so rounded corners are more appropriate. A similar effect can also be achieved with a structure with larger through-holes, such as a mesh-like shape. While the figure shows five through-holes, there is no limit to the number. Multiple through-holes may be arranged vertically or horizontally. Furthermore, through-holes shaped like a company logo or initials can be provided to expose the plasma area, allowing for use as a display.

[0027] <First Modification of Plasma Generation Unit> 4 is a perspective view for explaining a plasma generating unit according to a first modified example. The plasma generating unit 10A according to the first modified example differs from the basic structure described above in that it does not have an upper mask layer 14. As in the plasma generating unit according to the first modified example, the mask layer may be provided only on one side of the plasma generating unit 10A.

[0028] <Second Modification of Plasma Generation Unit> FIG. 5 is a perspective view illustrating a plasma generating unit according to a second modified example. The plasma generating unit 10B according to the second modified example differs from the basic structure described above in that it does not include the upper mask layer 14 and the lower mask layer 15. The upper mask layer 14 and the lower mask layer 15 may be omitted, as in the plasma generating unit 10B according to the second modified example. That is, by configuring the plasma generating unit 10B with only the dielectric layer 11, the upper electrode 12, and the lower electrode 13, it is possible to further reduce the size and the number of parts. Furthermore, if processes for manufacturing printed circuit boards, semiconductor ICs, etc. can be used to manufacture this plasma generating unit, process steps can be omitted, thereby reducing product costs.

[0029] Furthermore, as in the first and second modified examples, by omitting either or both of the upper mask layer 14 and the lower mask layer 15, the overall thickness can be reduced and flexibility can be increased, which is convenient when creating an ultra-compact plasma generation device.

[0030] <Third Modification of Plasma Generation Unit> FIG. 6 is a perspective view illustrating a plasma generation unit according to a third modification. The plasma generation unit 10C according to the third modification differs from the basic structure described above in that an air layer 18 is provided below the dielectric layer 11C. If air is considered a dielectric with a relative dielectric constant of 1 and the combined air and dielectric layer 11C are considered a single dielectric, the structure can be considered identical to the basic structure shown in FIG. 2. The composite relative dielectric constant (or dielectric constant) can be calculated from the respective relative dielectric constants (or dielectric constants) and thicknesses. The plasma generation unit 10C according to the third modification includes a dielectric layer 11C, an upper electrode 12, a lower electrode 13, an upper mask layer 14, a lower mask layer 15, and an air layer 18. The air layer 18 is provided between the dielectric layer 11C and the lower electrode 13. In the third modification, three surfaces can come into contact with gas: the air layer 18 between the upper electrode 12 and the lower electrode 13, the back surface of the lower electrode 13, and the back surface of the upper electrode 12. The back surface here refers to the surface opposite to the air layer 18. This improves the plasma utilization efficiency compared to when only the air layer 18 is used, and allows for plasma processing of a larger amount of gas.

[0031] <Fourth Modification of Plasma Generation Unit> FIG. 7 is a cross-sectional view illustrating a plasma generating unit according to a fourth modification. The plasma generating unit 10D according to the fourth modification differs from the third modification in that it does not include an upper mask layer 14. As with the third modification, if air is considered a dielectric with a dielectric constant of 1 and the dielectric layer 11C and the resulting air layer are considered a single dielectric, the resulting structure can be considered identical to the basic structure shown in FIG. 2. The composite dielectric constant (or permittivity) can be calculated from the respective permittivity (or permittivity) and thickness. The plasma generating unit 10D includes a dielectric layer 11C, an upper electrode 12, a lower electrode 13, a lower mask layer 15, and an air layer 18. As in the fourth modification, the air layer 18 may be provided between the dielectric layer 11C and the lower electrode 13, while the upper mask layer may be omitted. This configuration can achieve substantially the same effects as the third modification while reducing the number of components. Furthermore, when this electrode is fabricated using a process for manufacturing printed circuit boards or semiconductor ICs, a process step can be omitted, thereby reducing costs.

[0032] <Fifth Modification of Plasma Generation Unit> FIG. 8 is a cross-sectional view illustrating a plasma generating unit according to a fifth modification. The plasma generating unit 10E according to the fifth modification differs from the third modification in that it does not include an upper mask layer 14 and a lower mask layer 15. The plasma generating unit 10E also includes a dielectric layer 11Cb on the lower surface of the lower electrode 13. The plasma generating unit 10E includes dielectric layers 11Ca and 11Cb, an upper electrode 12, and a lower electrode 13. The dielectric layer 11Cb on the lower surface of the lower electrode 13 is used to support the lower electrode 13. As in the fifth modification, the upper and lower mask layers may be omitted while providing an air layer 18 between the dielectric layer 11Ca and the lower electrode 13. This configuration can achieve substantially the same effects as the third modification while reducing the number of components. In this way, the structure constituting the upper electrode 12 and the structure constituting the lower electrode 13 can have the same configuration. Furthermore, when this electrode is fabricated using a process for manufacturing a printed circuit board or a semiconductor IC, a process step can be omitted, thereby reducing costs. Furthermore, since there is less material in the thickness direction, flexibility can be improved.

[0033] The upper layer dielectric 11Ca and the air layer 18 function as a single dielectric. This dielectric constant can be calculated from the relative permittivity (or dielectric constant) and thickness of the upper layer 11Ca, and, if air is used as the gas, the relative permittivity (or dielectric constant) of the air and the thickness of the air layer 18. The lower layer dielectric 11Cb plays almost no role in plasma generation. However, this structure allows the upper layer electrode 12 and the lower layer electrode 13 to have the same configuration. This reduces manufacturing costs.

[0034] <Sixth Modification of Plasma Generation Unit> 9 is a cross-sectional view illustrating a plasma generating unit according to a sixth modified example. The plasma generating unit 10F according to the sixth modified example includes, from top to bottom, an air layer 18, an upper electrode 12, a dielectric layer 11Ca, an air layer 18, a lower electrode 13, a dielectric layer 11Cb, an air layer 18, an upper electrode 12, a dielectric layer 11Ca, an air layer 18, a lower electrode 13, and a dielectric layer 11Cb. In other words, the plasma generating unit 10F according to the fifth modified example is configured by stacking two plasma generating units 10E according to the fifth modified example in the thickness direction. The ends of the dielectric layers 11Ca and 11Cb are supported by a box-shaped housing 21F.

[0035] Inside the housing 21F, basic units in which an upper-layer electrode 12 is laminated only on one side (top surface) of a dielectric layer 11Ca and basic units in which a lower-layer electrode 13 is laminated only on one side (top surface) of a dielectric layer 11Cb are alternately arranged with an air layer (gas inlet layer) 18 between them. As a result, electrodes of opposite polarity are alternately laminated, but if a space in which plasma is not generated is desired, the electrodes do not need to be alternately arranged. By designing a space in which plasma is not generated in this way, it is possible to place a sensor, wiring, or other circuits between them. An air layer 18 is formed between each of the electrode layers adjacent in the vertical direction.

[0036] According to this modification, the plasma generating section 10F can be easily formed simply by stacking basic units each composed of a dielectric layer and an electrode layer (upper electrode 12 or lower electrode 13) at intervals. Furthermore, since plasma can be generated in multiple air layers 18, plasma can be generated efficiently in a small space. Furthermore, since no separate components such as spacers are required to space the basic units, multi-stage construction is easily possible, reducing manufacturing costs and shortening development time. Since the number of stacked electrodes can be freely changed, the amount of contact between plasma and gas can be controlled, and the contact area between plasma and gas can be easily changed, which has the advantage of easily constructing devices with different processing capacities.

[0037] The plasma generating unit 10 of this embodiment is manufactured by laminating materials such as electrode layers 12 and 13, dielectric layer 11, and mask layers 14 and 15. Methods for laminating each layer include known methods such as pressure bonding, thermocompression bonding, and adhesive application, and can be appropriately selected and used. Methods for forming through holes in the electrode layers 12 and 13 and mask layers 14 and 15 include known methods such as punching and etching, and can be appropriately selected and used.

[0038] The power supply unit (not shown) of this embodiment applies an AC voltage to the pair of electrode layers of the plasma generating unit 10. There are no particular restrictions on the specific contents of the power supply unit, and any known power supply device can be used as long as it can apply an AC voltage of a predetermined voltage at a predetermined frequency to the two electrode layers. The frequency of the AC voltage is preferably 50 Hz to 30 MHz, and more preferably 50 Hz to 100 kHz. The AC voltage is preferably 0.1 to 50 kV, and more preferably 0.2 to 10 kV.

[0039] In plasma-treated air, the active species generated by the plasma kill or inactivate microorganisms present in the air and decompose chemical substances, so by treating the air with plasma, it is possible to sterilize and deodorize the air. Furthermore, active species remain in the plasma-treated air. Therefore, by spraying the plasma-treated air onto an object, microorganisms present in the object are killed or inactivated, and chemical substances are decomposed, thereby sterilizing and deodorizing the object.

[0040] First Embodiment Next, a lighting device according to a first embodiment of the present invention will be described. FIG. 10 is a perspective view showing an illumination device according to a first embodiment, and FIG. 11 is a side view showing the illumination device according to the first embodiment. The illumination device 100 according to the first embodiment is a downlight type illumination device having a hood (shade) 33 that opens downward and a reflector 32 so as to illuminate downward. Examples of downlight type illumination devices include lighting fixtures such as downlights, desk lamps, floor lamps, and ceiling lights. The illumination device 100 basically comprises an illumination element 31, a socket 34, a hood 33, and a reflector 32. The illumination element 31 is not particularly limited, and examples thereof include an incandescent lamp, an LED, a fluorescent lamp, a halogen lamp, a mercury lamp, and a sodium lamp.

[0041] A gap exists between the hood 33 and the reflector 32. In the space between the hood 33 and the reflector 32, the plasma generating unit 10 is installed on a part of the reflector 32. In addition, a part of the hood 33 facing the plasma generating unit 10 is provided with a number of vent holes 30 that lead to the external space. An electric cord for applying an AC voltage to the plasma generating unit 10 is not shown. In addition, a power supply unit for applying an AC voltage to the plasma generating unit 10, a driving circuit for the lighting element, etc. can be built into the socket unit 34, etc., as necessary (not shown).

[0042] 12 and 13 are enlarged perspective views showing the vicinity of the plasma generating unit 10 of the lighting device 100 of the first embodiment. An AC voltage is applied to the plasma generating unit 10 from a power supply unit to generate plasma in the space around the plasma generating unit 10. Meanwhile, the lighting element 31 generates heat when lit, which heats the inside of the reflector 32 and the space between the hood 33 and the reflector 32. As a result, a convection phenomenon occurs in which the air in the space between the hood 33 and the reflector 32 rises.

[0043] 12, when the upper and lower portions of the gap space between the hood 33 and the reflector 32 are open, a portion of the air around the lighting device 100 flows in from the lower gap space 35a, rises due to air convection generated by the heat generated by the lighting elements 31, and is released into the external space from the upper gap space 35b, creating an air flow 36. In addition, a portion of the air passes through the ventilation holes 30 provided in the hood 33 and is released into the external space, creating an air flow 36. As a result, the air plasma-treated around the plasma generation unit 10 is released and diffused into the external space of the lighting device 100, enabling the external space to be plasma-treated.

[0044] 13, when the lower gap between the hood 33 and the reflector 32 is closed, a portion of the air around the lighting device 100 flows into the gap through the vent holes 30 provided in the hood 33, rises due to the convection of air generated by the heat generated by the lighting elements 31, and is released into the external space from the upper gap space 35b or again through the vent holes 30, creating an air flow 36. As a result, the air plasma-treated around the plasma generation unit 10 is released and diffused into the external space of the lighting device 100, thereby plasma-treating the external space.

[0045] Here, the plasma generation unit 10 may be installed on at least one of the hood 33, the reflector 32, and the intermediate portion between the hood 33 and the reflector 32, as long as it can perform the above-described functions. The plasma generation unit 10 may also be installed in a manner that is substantially integrated with the hood 33 or the reflector 32. The plasma generation unit 10 is preferably installed in a manner that allows it to be detached and attached to the lighting device 100, which facilitates replacement as needed in the event of a malfunction or other problem. A filter is preferably installed near the air inlet to prevent dust and fine debris from adhering to the plasma generation unit 10 due to air flowing in from the outside. A gap between the hood 33 and the reflector 32 is not necessary as long as an air flow can be created that circulates plasma-treated air and releases it into the space outside the lighting device 100.

[0046] 10 to 13 show an embodiment in which the plasma generating unit 10 is installed on a portion of the outer surface (outer surface) of the reflector 32 opposite the lighting element 31, but this is not limiting. The plasma generating unit 10 can be installed on the inner surface of the hood 33, on the inner or outer surface of the reflector 32, or in the space between the hood 33 and the reflector 32. The plasma generating unit 10 may be installed in one or more locations, or all around the entire circumference. Furthermore, since the plasma generating unit 10 can be manufactured in a thin and flexible form, the installation position, dimensions, and shape of the plasma generating unit 10 can be freely designed and adopted as needed. When installing the plasma generating unit 10 in a location that can be touched by hand, such as the inner surface of the hood 33, a mask layer or protective cover is installed to prevent direct contact with the electrode layer or plasma generation circuit.

[0047] In FIGS. 10 to 13, the upper gap space 35b and the vent hole 30 function as a release portion that releases the plasma-treated air to the outside space. The ventilation holes 30 may or may not be provided in the hood 33. Even in the case where ventilation holes 30 are provided, they may be provided in the hood 33, the reflector 32, or both. The position, number, dimensions, and shape of the ventilation holes 30 can be freely designed and adopted as needed.

[0048] A blower (not shown) may be installed in the lighting device 100 to forcibly create an air flow 36 that discharges the plasma-treated air into the space outside the lighting device 100. Examples of blowers include a fan, a blower, and a pump. The installation location, number, dimensions, shape, etc. of the blowers are not limited and can be freely selected. Furthermore, in order to guide the air flow 36 in a specific direction, a shielding plate, fins, piping, etc. may be installed along the air flow 36 as appropriate.

[0049] Fig. 14 is a schematic cross-sectional view of the vicinity of the plasma generation unit of the first embodiment. Fig. 14 shows a hood 33, a reflector 32, an illumination element 31, a socket unit 34, a dielectric layer 11, an upper-layer electrode 12, and a lower-layer electrode 13. The plasma generation unit has the same configuration as Fig. 5. For safety, an upper mask layer 14 may be installed above the upper-layer electrode 12, and a lower mask layer 15 may be installed below the lower-layer electrode 13, as in Figs. 1 to 3. Through holes 16 and 17 are not shown.

[0050] For safety reasons, it is preferable to have a function that cuts off the power supplied to the plasma generation unit when the hood 33 is removed. Furthermore, the reflector 32 can be partially or entirely detachable and connected with a connector or the like, allowing for easy replacement of the plasma generation unit. Furthermore, by making the upper electrode 12 the ground side, the lower electrode 13 on the high-voltage side is less likely to be touched, thereby enhancing safety. In this case, it is preferable not to provide a through-hole in the lower electrode 13 on the high-voltage side. Furthermore, the reflector 32 needs to be an insulator with the required thickness. However, if this is not possible, an insulating dielectric layer (not shown) may be provided between the lower electrode 13 and the reflector 32, or a spacer or the like may be used to provide a gap.

[0051] 14, the plasma generating unit is attached to the side of the reflector 32 opposite to the side where the lighting element 31 is located, but the plasma generating unit can also be attached to the same side of the reflector 32 as the lighting element 31. In this case, however, it is necessary to install a protective cover or the like to prevent hands from touching the plasma generating unit when replacing the lighting element 31, and some ingenuity is required to improve the appearance.

[0052] 15 is a schematic cross-sectional view of a first modified example near the plasma generation unit of the first embodiment. When a conductive reflector or a conductive reflector having an insulating layer on its surface is used as the reflector 32, all or part of the lower electrode 13 can be substituted with the conductive reflector 32. In this case, as shown in FIG. 15, a simple structure is obtained. The conductive reflector 32 may be covered with a dielectric mask layer, and is preferably on the ground side.

[0053] Figure 16 is a schematic cross-sectional view of a second modified example of the plasma generation unit and its vicinity in the first embodiment. Figure 16 shows the hood 33, reflector 32, lighting element 31, socket 34, protective cover 37, upper mask layer 14, upper electrode 12, dielectric layers 11a and 11b, air layer 18, lower electrode 13, and lower mask layer 15. The protective cover 37 is installed for safety purposes, but it may also be made of a member with fine holes that functions as a filter to prevent fine dust and dirt from entering the plasma generation unit. The protective cover 37 may be fixed to the reflector 32, the hood 33, or both the reflector 32 and the hood 33.

[0054] Between the upper electrode 12 and the lower electrode 13, there are two dielectric layers 11a and 11b and an air layer 18, which are obtained by dividing the dielectric layer 11 of the basic electrode structure 10B shown in Figure 5 into three. This allows the plasma and the gas to come into contact on three surfaces: the surface of the upper electrode 12, the space between the upper electrode 12 and the lower electrode 13, and the back surface of the lower electrode 13. Of course, the structure is not limited to these layer structures, and may be formed by laminating multiple dielectric layers or multiple air layers. The upper mask layer 14 and the lower mask layer 15 can be provided as needed. The upper mask layer 14 and the lower mask layer 15 are provided mainly for the purpose of protecting the electrode layers when the material constituting the upper electrode 12 or the lower electrode 13 is thin and its mechanical strength is weakened, or when the upper electrode 12 or the lower electrode 13 is subject to erosion by the environment. Furthermore, by carefully selecting the shape, structure, and dielectric constant of the material used for the upper mask layer 14 and the lower mask layer 15, the electric field strength at the edges of the electrode layers can be reduced, thereby extending the life of the electrode layers.

[0055] Second Embodiment Next, a lighting device according to a second embodiment of the present invention will be described. Fig. 17 is a perspective view showing an illumination device according to a second embodiment. Fig. 18 is an enlarged perspective view showing a portion of an illumination device according to the second embodiment. Illumination device 200 has an illumination element 43 of a long tube fluorescent lamp type, and has a long reflector 32 folded in half along the length of illumination element 43. Illumination element 43 has a cylindrical shape that extends in the longitudinal direction, like a long tube fluorescent lamp, and the light source can be an LED, a fluorescent lamp, or the like.

[0056] The lighting device 200 is basically composed of a main body case 42, lighting elements 43, and a reflector 32. Inside the main body case 42 are housed a plasma processing box 38 including the plasma generation unit 10, a power supply unit (not shown) for applying AC voltage to the plasma generation unit 10, a driving circuit (not shown) for the lighting elements, etc. Inside the plasma processing box 38 are an air intake fan 39, a filter 40, the plasma generation unit 10, an air shielding plate 41, and an air vent 30. The air vent 30 penetrates the wall of the plasma processing box 38 and the reflector 32.

[0057] The air flow 36 in the lighting device 200 is described below. A portion of the air around the lighting device 200 is drawn in by an air intake fan 39 and taken into the plasma processing box 38. The taken-in air passes through a filter 40 to remove fine dust and dirt. The air is then plasma-treated by passing around the plasma generation unit 10. The plasma-treated air is discharged to the outside of the plasma processing box 38 through the air vent 30. The air vent 30 functions as a discharge unit that discharges the plasma-treated air into the external space. The number, position, dimensions, and shape of the plasma generation units 10 in the plasma processing box 38 are not particularly limited as long as they can effectively plasma-treat the air along the air flow 36 within the plasma processing box 38.

[0058] An air intake fan 39 is installed inside the plasma processing box 38 as needed. Because heat generated by the lighting elements 43 when lit creates air convection, the air intake fan 39 is not necessarily required if sufficient airflow can be achieved. The air shielding plate 41 controls the airflow and ensures that plasma-treated air is discharged to the outside through the air vent 30. Fins or other devices can be installed inside the plasma processing box 38 as needed to control the air volume, direction, or residence time. While Figures 17 and 18 show a single filter 40, multiple filters with different functions may be used as needed. Furthermore, a separate filter may be installed in the air vent 30 to prevent foreign matter from entering or to prevent backflow of air.

[0059] The plasma processing box 38 may also be designed to be detachable from the main case 42. This allows for quick replacement of the plasma processing components in the event of a malfunction. The main case 42 may also incorporate a high-voltage power supply circuit, various sensors for temperature and humidity, and, if necessary, wirelessly connectable modules and controllers. These may provide information on the ambient air quality, the lifespan and malfunction status of the lighting device, and information on the function, operating status, lifespan, and operating time of the plasma generation unit. Especially when the lighting device is installed in a location that is difficult to access, the status of the lighting device can be monitored via a smartphone or computer, improving maintenance. This information may also be used to determine the room's ventilation target or to provide digital information to the ventilation system, thereby automating the ventilation system.

[0060] 19 is a schematic side view showing a lighting device according to the second embodiment. When an air intake fan 39 is provided inside the plasma processing box 38, the air that has been plasma-treated inside the plasma processing box 38 is discharged to the outside through the air vents 30. The discharged plasma-treated air rides on the upward air convection flow 44 generated by the heat generated by the lighting elements 43 and is diffused into the space outside the lighting device 200, thereby enabling the external space to be plasma-treated.

[0061] On the other hand, even if there is no air intake fan 39 inside the plasma processing box 38, the heat generated by the lighting elements 43 slightly warms the reflector 32, which creates a convection flow 44 of air flowing upward from the lighting elements 43. This air flow 44 draws the air that has been plasma-treated inside the plasma processing box 38 out through the vent holes 30 provided at the top of the reflector 32 and diffuses it into the space outside the lighting device 200, thereby enabling the external space to be plasma-treated.

[0062] 19, the plasma processing box 38 is installed on only one side of the reflector 32, but it may be installed on both sides of the reflector 32. Also, in FIG. 19, an example of a reflector having a triangular cross section (inverted roof shape) is shown as the reflector 32, but the same effect can be obtained with a reflector having an arc shape or a sloping flat shape.

[0063] Third Embodiment Next, a lighting device according to a third embodiment of the present invention will be described. FIG. 20 is a perspective view showing a lighting device according to a third embodiment. FIG. 21 is an enlarged perspective view showing a portion of the lighting device according to the third embodiment. The lighting device 300 according to the third embodiment is a so-called lamp stand, and its basic components include a lamp unit 45, a support 46, and a base 47. The lamp unit 45 has a cylindrical outer hood, and an air intake 49 and an air exhaust 48 on its outer surface. As shown in FIG. 21, an illumination element 50 and an illumination element driver 51 are installed on the underside of the lamp unit 45. The illumination element 50 is ring-shaped and is located between the cylindrical hood and the illumination element driver 51, and can illuminate the area below the lamp unit 45. The illumination element driver 51 is disk-shaped and includes an illumination element driver, a power supply, a motor (none of which are shown), and the like, and can rotate the entire lamp unit 45 as needed.

[0064] 22 is a semi-transparent side view of a portion of an illumination device according to the third embodiment. The lamp unit 45 includes a cylindrical plasma driver 53, a ring-shaped plasma generator 52, a ring-shaped illumination element 50, and a disk-shaped illumination element driver 51. The cylindrical plasma driver 53 includes a built-in power supply (not shown) for applying an AC voltage to the electrode layer of the plasma generator 52.

[0065] When the ring-shaped lighting element 50 is lit, it generates heat, generating an upward convection flow 36 of air around the lighting element 50. As a result, some of the air around the lighting device 300 is drawn in from below the lamp unit 45 and into the lamp unit 45 through the air intake 49. The air drawn into the lamp unit 45 flows through the lamp unit 45 along the dotted line indicated by 36, is plasma-treated around the ring-shaped plasma generation unit 52, and is then discharged to the outside of the lamp unit 45 through the air outlet 48. The plasma-treated air discharged to the outside is diffused into the external space, thereby enabling the space outside the lighting device 300 to be plasma-treated. The air outlet 48 functions as a discharge unit that discharges the plasma-treated air into the external space.

[0066] The number, position, dimensions, and shape of the plasma generating units 52 in the lamp unit 45 are not particularly limited as long as they can effectively plasma-treat the air along the air flow 36 in the lamp unit 45. FIG. 23 is a semi-transparent side view showing a modified example of a portion of the lighting device according to the third embodiment. FIG. 23 shows an embodiment in which strip-shaped plasma generating units 54 are installed inside a cylindrical hood on the outer layer of the lamp unit 45. FIG. 23 also shows an embodiment in which strip-shaped plasma generating units 55 are installed outside a cylindrical plasma driving unit 53.

[0067] 22 and 23, heat generated by the lighting elements 50 creates an upward convection flow 36 of air, enabling the space outside the lighting device 300 to be plasma-treated, eliminating the need for a fan to draw air into the lamp unit 45. As a result, there is no fan noise, there are no mechanically driven parts, and there is little risk of malfunction. However, a fan may be further installed inside the lamp unit 45 to forcibly create a steady air flow 36.

[0068] The lighting device 300 of the third embodiment can be used as a lighting device that impressively displays a specific shape such as a company logo or product name. Consider the case where a strip-shaped plasma generating unit 54 shown in FIG. 23 is used. A cross shape is used as a specific example of a company logo. FIG. 24 is a plan view of the strip-shaped plasma generating unit 54. FIG. 25 is a cross-sectional view of the strip-shaped plasma generating unit 54. Of the pair of electrode layers of the plasma generating unit 54, the planar shape of the through-hole 56 in the upper electrode 12 is a cross shape.

[0069] Here, the cylindrical outer hood of the lamp unit 45 is made of a transparent material, and an AC voltage is applied to the pair of electrode layers 12, 13 of the plasma generating unit 54. This causes plasma emission around the through-hole 56, and a purple or other colored light appears in the shape of a cross on the hood of the through-hole 56. [Explanation of symbols]

[0070] 10 Plasma generation unit 11 Dielectric layer 12 Upper layer electrode (electrode layer) 13 Lower electrode (electrode layer) 14 Upper mask layer (mask layer) 15 Lower mask layer (mask layer) 16, 17 Through holes 18 Air Layer 30 ventilation holes 31 Lighting elements 32 Reflector 33 Food 34 Socket part 35 Space Between 36 Air Flow 37 Protective cover 100 lighting equipment 200 lighting equipment 300 lighting equipment

Claims

1. A lighting element; At least one of a hood and a reflector; a plasma generating unit that has a dielectric layer and a pair of electrode layers provided on both sides of the dielectric layer and generates plasma; a power supply unit that applies an AC voltage to the pair of electrode layers, A lighting device characterized in that the plasma generating unit is installed around the lighting element.

2. The lighting device according to claim 1 , wherein the electrode layer has a through-hole penetrating therethrough in a thickness direction.

3. 3. The lighting device according to claim 1, further comprising a discharge section for discharging the air plasma-treated by the plasma generating section into an external space.

4. 3. The lighting device according to claim 1, wherein the air that has been plasma-treated in the plasma generating section is released to an external space by air convection generated by heat generated by the lighting element.

5. 3. The lighting device according to claim 1, further comprising a blower for discharging the air that has been plasma-treated in the plasma generating section to an external space.

6. 3. The lighting device according to claim 1, wherein the plasma generating portion is flexible.

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