Ultraviolet irradiation device

Abstract

To provide an ultraviolet-ray irradiation device capable of increasing a uniformity ratio.SOLUTION: An ultraviolet-ray irradiation device according to an embodiment, includes: a light emission pipe that is extended to a first direction, has a cylinder shape, and in which a gas is entered into an inner space; an internal electrode provided to an inner part of the light emission pipe; an outer electrode provided to an outer part of the light emission pipe; and a cooling part having a concave part extended to the first direction. The outer electrode includes: an electrode body that is provided between an outer surface of the light emission pipe and an inner surface of the concave part of the cooling part, and is opposite to the inner electrode; and a plurality of attachment parts that is provided to each of end parts on both sides of the electrode in a second direction orthogonal to the first direction. The plurality of attachment parts is attached to a surface where the concave part opens in parallel to the first direction. A center-to-center distance of the plurality of attachment parts is 30 mm or more and 150 mm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to an ultraviolet irradiation device.

Background Art

[0002] There is an ultraviolet irradiation device including a barrier discharge lamp that irradiates ultraviolet rays. The ultraviolet irradiation device including a barrier discharge lamp is used for, for example, surface treatment such as removal of organic substances (photo cleaning treatment) adhering to the surface of an object, surface modification, and formation of an oxide film. The barrier discharge lamp has, for example, an internal electrode provided inside a light-emitting tube and an external electrode provided outside the light-emitting tube. When an alternating voltage is applied to the internal electrode and the external electrode, dielectric barrier discharge occurs, and ultraviolet rays having a specific wavelength are irradiated according to the type of gas enclosed inside the light-emitting tube. In addition, when the barrier discharge lamp is lit, heat is generated together with ultraviolet rays. Therefore, a cooling unit may be provided outside the light-emitting tube.

[0003] In recent years, in order to perform a wider range of processing, the length of the barrier discharge lamp in the tube axis direction has a tendency to become longer. When the length of the barrier discharge lamp in the tube axis direction becomes longer, the length of the external electrode in the tube axis direction becomes longer. When the length of the external electrode becomes longer, the amount of deformation of the external electrode tends to increase due to the generated heat. When the amount of deformation of the external electrode increases, the distance between the internal electrode and the external electrode may change, and the discharge state may change. When the discharge state changes, the uniformity decreases, and processing unevenness is likely to occur.

[0004] Therefore, even when the length of the barrier discharge lamp in the tube axis direction becomes longer, it has been desired to develop an ultraviolet irradiation device capable of increasing the uniformity.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The problem that this invention aims to solve is to provide an ultraviolet irradiation device that can achieve high uniformity. [Means for solving the problem]

[0007] The ultraviolet irradiation device according to the embodiment comprises: a discharge tube extending in a first direction, having a cylindrical shape and filled with gas in its internal space; an internal electrode provided inside the discharge tube; an external electrode provided outside the discharge tube; and a cooling section having a recess extending in the first direction. The external electrode is provided between the outer surface of the discharge tube and the inner surface of the recess of the cooling section and has an electrode body facing the internal electrode; and a plurality of mounting portions provided at each of the ends on both sides of the electrode body in a second direction perpendicular to the first direction. The length of the discharge tube and the length of the electrode body in the first direction are 600 mm or more. The plurality of mounting parts are mounted on the surface of the cooling unit where the recess opens, in the first direction. The distance between the centers of the plurality of mounting parts is 30 mm or more and 150 mm or less. [Effects of the Invention]

[0008] According to embodiments of the present invention, it is possible to provide an ultraviolet irradiation device that can achieve a high degree of uniformity. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic exploded view illustrating the ultraviolet irradiation device according to this embodiment. [Figure 2] This is a schematic diagram illustrating a barrier discharge lamp. [Figure 3] Figure 2 is a schematic cross-sectional view of the barrier discharge lamp in the direction of line AA. [Figure 4] This is a schematic perspective view of the external electrode. [Figure 5] This table shows the relationship between the distance between the centers of the mounting parts and the degree of uniformity. [Modes for carrying out the invention]

[0010] The embodiments will be illustrated below with reference to the drawings. In each drawing, the same reference numerals are used for similar components, and detailed explanations are omitted as appropriate. Also, the arrows X, Y, and Z in each drawing represent three mutually orthogonal directions. For example, the direction perpendicular to the tube axis direction of the barrier discharge lamp 1 (discharge tube 11) (corresponding to an example of the second direction) is the X direction, the tube axis direction of the barrier discharge lamp 1 (discharge tube 11) (corresponding to an example of the first direction) is the Y direction, and the direction of ultraviolet irradiation is the Z direction.

[0011] Figure 1 is a schematic exploded view illustrating the ultraviolet irradiation device 100 according to this embodiment. In Figure 1, an example is shown where one barrier discharge lamp 1 is provided. However, the number of barrier discharge lamps 1 can be appropriately changed depending on the application and the size of the object to be irradiated. In other words, it is sufficient to provide at least one barrier discharge lamp 1. As shown in Figure 1, the ultraviolet irradiation device 100 includes, for example, a barrier discharge lamp 1, a cooling unit 2, a socket 3, and a case 4.

[0012] Figure 2 is a schematic diagram illustrating barrier discharge lamp 1. Figure 3 is a schematic cross-sectional view of the barrier discharge lamp 1 in the AA direction in Figure 2. Note that in Figure 3, the cooling unit 2 is also depicted. As shown in Figures 2 and 3, the barrier discharge lamp 1 includes, for example, a discharge tube 11, an internal electrode 12, a reflective film 13, a holder 14, lead wires 15, and an external electrode 16.

[0013] The discharge tube 11 has a cylindrical shape, with its overall length (length in the direction of the tube) being longer than its diameter. The discharge tube 11 can be, for example, a cylindrical tube. Sealing portions 11a are provided at each of the ends of the discharge tube 11 in the direction of the tube axis. By providing the sealing portions 11a, the internal space of the discharge tube 11 can be airtightly sealed. The sealing portions 11a can be formed, for example, using a pinch seal method or a shrink seal method.

[0014] Furthermore, a conductive portion 11b and an outer lead 11c can be provided inside the sealing portion 11a. One conductive portion 11b can be provided for each sealing portion 11a. The planar shape of the conductive portion 11b is, for example, a rectangle. The conductive portion 11b is in the form of a thin film. The conductive portion 11b can be formed from, for example, molybdenum foil.

[0015] The outer lead 11c is linear and can be provided on the sealing portion 11a on the side where the lead wire 15 is provided. One end of the outer lead 11c is electrically connected to the conductive portion 11b. The vicinity of the end of the outer lead 11c can be laser-welded or resistance-welded to the conductive portion 11b. The other end of the outer lead 11c can be exposed from the sealing portion 11a. The outer lead 11c contains, for example, molybdenum.

[0016] The internal space of the discharge tube 11 is filled with gas. In the barrier discharge lamp 1, a barrier discharge is performed between the internal electrode 12 and the external electrode 16, supplying high-energy electrons to the filled gas and generating excimer-excited molecules. When the excimer-excited molecules return to their original state, light with a specific peak wavelength is generated depending on the type of gas. Therefore, the gas sealed in the internal space of the discharge tube 11 can be appropriately changed according to the application of the barrier discharge lamp 1. The gas sealed in the internal space of the discharge tube 11 can be, for example, a noble gas such as krypton, xenon, argon, or neon, or a mixed gas of several types of noble gases. The gas can also contain halogen gases as needed.

[0017] The pressure of the gas (enclosed pressure) in the internal space of the light-emitting tube 11 at 25°C can be, for example, about 80 kPa to 200 kPa. The pressure of the gas (enclosed pressure) in the internal space of the light-emitting tube 11 at 25°C can be determined by the standard state of the gas (SATP (Standard Ambient Temperature and Pressure): temperature 25°C, 1 bar).

[0018] For example, when optically cleaning the surface of a glass plate for a flat panel display, it is preferable to use xenon as the enclosed gas. The enclosed pressure of xenon can be, for example, about 93 kPa. If xenon is used as the enclosed gas, ultraviolet light with a peak wavelength of 172 nm can be generated, thus enhancing the cleaning effect.

[0019] In this case, the light-emitting tube 11 is formed of a material having a high transmittance of ultraviolet light with a peak wavelength of 200 nm or less. For example, the light-emitting tube 11 is formed of a material that transmits ultraviolet light and contains SiO2 (silicon dioxide). The light-emitting tube 11 can be formed of, for example, synthetic quartz glass.

[0020] The internal electrode 12 is provided inside the light-emitting tube 11. The internal electrode 12 has, for example, a coil 12a and a leg 12b. The coil 12a and the leg 12b can be integrally formed. The coil 12a and the leg 12b are formed, for example, by plastically processing a wire. The wire diameter (diameter) of the wire is, for example, about 0.2 mm to 1.0 mm.

[0021] The coil 12a and the leg 12b mainly contain tungsten, for example. For example, the coil 12a and the leg 12b can be formed using doped tungsten obtained by adding potassium or the like to tungsten. If the coil 12a is formed using doped tungsten, the dimensional stability of the coil 12a can be enhanced.

[0022] > The coil 12a is spiral in shape and is located in the internal space of the discharge tube 11. The coil 12a extends along the tube axis of the discharge tube 11 through the central region of the internal space of the discharge tube 11. The pitch dimension P of the coil 12a can be, for example, about 10 mm to 120 mm.

[0023] As shown in Figure 3, the gap S between the coil 12a and the inner wall of the discharge tube 11 in a direction perpendicular to the tube axis direction of the discharge tube 11 is preferably 10 mm or less. Alternatively, the gap S may be omitted, and the coil 12a and the reflective film 13 may be in contact. Furthermore, if the reflective film 13 is not provided, the coil 12a and the inner wall of the discharge tube 11 may be in contact. If the gap S is less than or equal to a predetermined dimension, a stable barrier discharge can be generated at a low voltage. Therefore, for example, the outer diameter of the coil 12a can be set so that a predetermined gap S is provided according to the inner diameter of the discharge tube 11.

[0024] Legs 12b are provided at each of the ends of the coil 12a. Legs 12b are linear in shape and extend from the ends of the coil 12a along the tube axis of the discharge tube 11.

[0025] The end of leg 12b is electrically connected to the conductive part 11b inside the sealing part 11a. The vicinity of the end of leg 12b can be laser-welded or resistance-welded to the conductive part 11b.

[0026] The reflective film 13 is in the form of a film and is provided on the inner wall of the discharge tube 11. The reflective film 13 can be provided between the external electrode 16 and the internal electrode 12 (coil 12a). The reflective film 13 reflects ultraviolet light generated in the internal space of the discharge tube 11 that does not travel in the direction of irradiation toward the direction of irradiation. If the reflective film 13 is provided, the efficiency of ultraviolet light extraction can be improved. In addition, if the reflective film 13 is provided, the area of ​​the discharge tube 11 that is directly incident on by ultraviolet light can be reduced, thereby suppressing chemical structural changes of the discharge tube 11 caused by ultraviolet light.

[0027] As shown in Figure 3, when viewed from a direction along the tube axis of the discharge tube 11, the reflective film 13 can be provided in a range where the central angle θ1 is approximately 180° to 300°. The length L1 of the reflective film 13 in the axial direction of the tube can be greater than or equal to the length L2 of the coil 12a. In this way, the efficiency of ultraviolet light extraction can be effectively improved.

[0028] The thickness of the reflective film 13 can be, for example, about 100 μm to 300 μm. This makes it easy to maintain good reflectivity against ultraviolet light. The reflective film 13 contains, for example, SiO2. The reflective film 13 may also contain particles that scatter ultraviolet light. These ultraviolet light-scattering particles include, for example, aluminum oxide.

[0029] The reflective film 13 is not strictly necessary and can be omitted. However, if the reflective film 13 is provided, the efficiency of ultraviolet light extraction can be improved, and chemical structural changes of the discharge tube 11 due to ultraviolet light can be suppressed.

[0030] The holder 14 is provided at each end of the discharge tube 11 in the axial direction of the tube. The holder 14 covers the ends of the discharge tube 11. The holder 14 can be formed from, for example, an organic material such as resin or an inorganic material such as ceramics. The holder 14 may include, for example, steatite or aluminum oxide. The holder 14 may be in contact with the external electrode 16 or may be provided at a distance from the external electrode 16.

[0031] The lead wire 15 is electrically connected to the end of the outer lead 11c that is exposed from the sealing portion 11a. The lead wire 15 is electrically connected to the internal electrode 12 via the outer lead 11c and the conductive portion 11b. For example, a lighting circuit provided outside the ultraviolet irradiation device 100 can be electrically connected to the lead wire 15. Note that, as shown in Figure 2, the lead wire 15 can be provided on only one end of the discharge tube 11, or on both ends of the discharge tube 11.

[0032] The external electrode 16 is located outside the discharge tube 11. Figure 4 is a schematic perspective view of the external electrode 16. As shown in Figures 1 to 4, the external electrode 16 has, for example, an electrode body 16a and a plurality of mounting parts 16b. The electrode body 16a and the plurality of mounting parts 16b can be formed integrally.

[0033] The electrode body 16a extends along the outer surface of the discharge tube 11, in the direction of the tube axis of the discharge tube 11. The electrode body 16a is provided between the outer surface of the discharge tube 11 and the inner surface of the recess 2a of the cooling section 2, which will be described later. The electrode body 16a faces the internal electrode 12 (coil 12a). If a reflective film 13 is provided, the electrode body 16a can be provided in a position facing the reflective film 13.

[0034] If the gap between the electrode body 16a on the discharge tube 11 side and the outer surface of the discharge tube 11 is made too large, the ultraviolet light extraction efficiency may decrease. For example, when a barrier discharge occurs between the internal electrode 12 and the electrode body 16a, if there is ambient air in the gap between the internal electrode 12 and the electrode body 16a, hydrogen nitrate gas may be generated. Also, moisture from the environment may condense on the surface of the electrode body 16a. When hydrogen nitrate gas dissolves in the condensed moisture, nitric acid is produced. When nitric acid comes into contact with the outer surface of the discharge tube 11, the transmittance of ultraviolet light decreases. If such chemical reactions occur repeatedly each time the barrier discharge lamp 1 is lit, the ultraviolet light extraction efficiency may decrease over time.

[0035] On the other hand, if the gap between the surface of the electrode body 16a facing the discharge tube 11 and the outer surface of the discharge tube 11 is made too small, it becomes difficult to attach the electrode body 16a to the discharge tube 11 due to dimensional tolerances and twisting. Therefore, when the radius of the discharge tube 11 is R1 (mm) and the radius of curvature of the surface of the electrode body 16a facing the discharge tube 11 is R2 (mm), it is preferable to set the gap to "0.93 ≤ R1 / R2 ≤ 0.99". In this way, it is possible to suppress a decrease in the efficiency of ultraviolet light extraction and to facilitate the attachment of the external electrode 16.

[0036] Furthermore, the discharge tube 11, internal electrode 12, and reflective film 13 are more prone to wear than the external electrode 16. Therefore, it is preferable to make the discharge tube 11 easily removable from the external electrode 16 (electrode body 16a). If "0.93 ≤ R1 / R2 ≤ 0.99", the discharge tube 11 becomes easier to remove from the external electrode 16 (electrode body 16a), thereby improving maintainability and reducing running costs.

[0037] Furthermore, as shown in Figure 3, when viewed from a direction along the tube axis of the discharge tube 11, if the central angle θ2 of the surface of the electrode body 16a on the discharge tube 11 side becomes small, the area in which the electrode body 16a and the internal electrode 12 face each other becomes small, which may reduce the amount of ultraviolet light. On the other hand, if the central angle θ2 becomes large, the ultraviolet light generated in the internal space of the discharge tube 11 is more easily absorbed by the electrode body 16a, which may reduce the efficiency of ultraviolet light extraction. For this reason, it is preferable to set the central angle θ2 to be between 180° and 300°. In this way, the amount of ultraviolet light can be increased, and the decrease in the efficiency of ultraviolet light extraction can be suppressed.

[0038] The central angle θ2 of the electrode body 16a on the side facing the discharge tube 11 may be the same as or different from the central angle θ1 of the reflective film 13. The length of the electrode body 16a in the axial direction of the tube can be, for example, the same as the length L1 of the reflective film 13 in the axial direction of the tube. The thickness of the electrode body 16a can be, for example, 0.1 mm or more and 1.0 mm or less.

[0039] The electrode body 16a contains a conductive material such as metal. The electrode body 16a is formed using, for example, stainless steel or aluminum. When the barrier discharge lamp 1 is lit, heat is generated along with ultraviolet light. Therefore, if the electrode body 16a contains a material with high thermal conductivity such as metal, the electrode body 16a can also be used as a heat dissipation part.

[0040] In recent years, there has been a tendency for the length of the barrier discharge lamp 1 in the axial direction to increase in order to perform processing over a wider area. When the length of the barrier discharge lamp 1 in the axial direction increases, the length of the electrode body 16a in the axial direction also increases. When the length of the electrode body 16a increases, the amount of deformation of the electrode body 16a may increase due to the heat generated when the barrier discharge lamp 1 is lit.

[0041] If the deformation of the electrode body 16a increases, the distance between the internal electrode 12 (coil 12a) and the electrode body 16a may change, potentially altering the discharge state. A change in the discharge state may result in uneven illumination distribution and a decrease in uniformity. A decrease in uniformity makes it easier for uneven processing to occur.

[0042] For example, if the length of the barrier discharge lamp 1 in the axial direction of the tube exceeds 750 mm, the uniformity decreases, and uneven processing tends to increase.

[0043] Therefore, the external electrode 16 is provided with multiple mounting portions 16b. As shown in Figures 3 and 4, the multiple mounting portions 16b are provided at each of the ends on both sides of the electrode body 16a in a direction perpendicular to the tube axis direction of the discharge tube 11. One end of the multiple mounting portions 16b is provided at the end of the electrode body 16a. In a direction perpendicular to the tube axis direction of the discharge tube 11, the multiple mounting portions 16b extend away from the discharge tube 11.

[0044] The length Y1 of the mounting portion 16b of the discharge tube 11 in the direction of the tube axis can be, for example, 5 mm or more and 20 mm or less. The length X1 of the mounting portion 16b of the discharge tube 11 in the direction perpendicular to the direction of the tube axis can be, for example, 5 mm or more and 20 mm or less. The thickness and material of the multiple mounting portions 16b can be the same as those of the electrode body 16a.

[0045] Multiple mounting portions 16b are arranged in the direction of the tube axis of the discharge tube 11. Multiple mounting portions 16b are attached to the surface of the cooling unit 2 where the recess 2a opens. Multiple mounting portions 16b can be attached to the cooling unit 2 using fastening members such as screws. Therefore, each of the multiple mounting portions 16b can be provided with a hole 16b1 that penetrates in the thickness direction.

[0046] By attaching multiple mounting parts 16b to the cooling part 2, deformation of the electrode body 16a due to the heat generated when the barrier discharge lamp 1 is lit can be suppressed. Suppressing deformation of the electrode body 16a suppresses changes in the distance between the internal electrode 12 (coil 12a) and the external electrode 16 (electrode body 16a), which would otherwise change the discharge state. Suppressing changes in the discharge state allows for higher uniformity. Therefore, the occurrence of processing irregularities can be suppressed.

[0047] In this case, shortening the distance Y2 (pitch dimension) between the centers of the mounting portion 16b in the axial direction of the pipe makes deformation of the electrode body 16a less likely. Figure 5 is a table showing the relationship between the center-to-center distance Y2 of the mounting portion 16b and the degree of uniformity. Figure 5 shows the case where the length of the discharge tube 11 in the axial direction of the tube is 1400 mm. In the illuminance column, "0" represents the position of the center of the discharge tube 11 in the direction of the tube axis. "300" represents a position of 300 mm in one direction from the center of the discharge tube 11, "600" represents a position of 600 mm, and "700" represents a position of 700 mm. "-300" represents a position of 300 mm in the other direction from the center of the discharge tube 11, "-600" represents a position of 600 mm, and "-700" represents a position of 700 mm. Uniformity is defined as "1 - (highest illuminance - lowest illuminance) / (highest illuminance + lowest illuminance)". The closer the uniformity is to "1", the higher the uniformity; in other words, the closer the uniformity is to "1", the more uniform the illuminance distribution is.

[0048] As can be seen from Figure 5, the uniformity can be increased by setting the distance Y2 between the centers of the mounting parts 16b to 150 mm or less. In this case, even if the distance Y2 between the centers of the mounting parts 16b is less than 30 mm, the uniformity cannot be further increased. Also, if the distance Y2 between the centers of the mounting parts 16b is less than 30 mm, the number of mounting parts 16b increases, making the attachment and removal of the external electrodes 16 complicated.

[0049] Therefore, it is preferable that the distance Y2 between the centers of the mounting portions 16b be 30 mm or more and 150 mm or less. This allows for a higher degree of uniformity, thereby reducing processing irregularities. Furthermore, since the number of mounting portions 16b is not excessively large, the attachment and removal of the external electrodes 16 does not become complicated.

[0050] Furthermore, while Figure 1 illustrates the case where the center-to-center distance Y2 is constant (where multiple mounting parts 16b are provided at equal intervals), the center-to-center distance Y2 may vary depending on the position of the barrier discharge lamp 1 in the axial direction of the tube. For example, the temperature tends to be higher on the center side of the barrier discharge lamp 1 than on the end side. Therefore, for example, the center-to-center distance Y2 on the center side of the barrier discharge lamp 1 can be made shorter than the center-to-center distance Y2 on the end side.

[0051] Furthermore, in Figures 1 and 4, an example is shown where the mounting portion 16b provided at one end of the electrode body 16a and the mounting portion 16b provided at the other end of the electrode body 16a are located at the same position in a direction perpendicular to the tube axis direction of the barrier discharge lamp 1. However, they may be located at different positions.

[0052] Furthermore, if the length of the barrier discharge lamp 1 in the axial direction increases, the length of the discharge tube 11 in the axial direction also increases. When the length of the discharge tube 11 increases, the amount of deformation of the discharge tube 11 may increase due to the heat generated when the barrier discharge lamp 1 is lit.

[0053] If the deformation of the discharge tube 11 becomes large, the distance between the internal electrode 12 (coil 12a) and the electrode body 16a may change, potentially altering the discharge state. Furthermore, a gap may form between the discharge tube 11 and the cooling unit 2, potentially altering the cooling state. Changes in the discharge state or cooling state can further increase the likelihood of processing inconsistencies.

[0054] For example, if the length of the discharge tube 11 and the length of the electrode body 16a in the axial direction of the tube exceeds 600 mm, the uniformity may decrease further, potentially leading to even greater processing unevenness.

[0055] Therefore, as shown in Figure 3, a positioning member 16c can be further provided to regulate the position of the electrode body 16a and the position of the discharge tube 11 in a direction perpendicular to the tube axis direction of the discharge tube 11. The positioning member 16c is plate-shaped. The positioning member 16c is provided, for example, between the mounting portion 16b and the surface of the cooling portion 2 where the recess 2a opens. The number of positioning members 16c can be, for example, the same as the number of mounting portions 16b.

[0056] The positioning member 16c can be attached to the cooling unit 2 together with the mounting part 16b using, for example, fastening members such as screws. Therefore, the positioning member 16c can be provided with a hole that penetrates in the thickness direction.

[0057] The length of the positioning member 16c in the tube axis direction of the discharge tube 11 can be, for example, the same as the length Y1 of the mounting portion 16b. That is, the length of the positioning member 16c in the tube axis direction of the discharge tube 11 can be, for example, 5 mm or more and 20 mm or less. The length of the positioning member 16c in the direction perpendicular to the tube axis direction of the discharge tube 11 can be, for example, the same as the length X1 of the mounting portion 16b. The thickness of the positioning member 16c can be, for example, about 0.3 mm. The material of the positioning member 16c can be, for example, a metal such as stainless steel.

[0058] When the positioning member 16c is attached to the cooling unit 2, a small gap may be provided between one end of the positioning member 16c and the electrode body 16a, and between the electrode body 16a and the outer surface of the discharge tube 11, or no gap may be provided.

[0059] Furthermore, although the example given illustrates the case where a positioning member 16c is provided for each of the multiple mounting portions 16b, it is also possible to provide one positioning member for multiple mounting portions 16b. For example, a pair of positioning members can be provided for a single external electrode 16.

[0060] If a positioning member 16c is provided, deformation of the electrode body 16a and the discharge tube 11 due to the heat generated when the barrier discharge lamp 1 is lit can be suppressed. Suppressing deformation of the electrode body 16a and the discharge tube 11 can suppress changes in the distance between the internal electrode 12 (coil 12a) and the external electrode 16 (electrode body 16a), which can change the discharge state, and preventing gaps from forming between the discharge tube 11 and the cooling unit 2, which can change the cooling state. Suppressing changes in the discharge state and the cooling state can further increase uniformity. Therefore, the occurrence of processing irregularities can be further suppressed.

[0061] Next, we will return to Figure 1 and describe the cooling unit 2, socket 3, and case 4. As shown in Figures 1 and 3, the cooling unit 2 faces the discharge tube 11 with the external electrode 16 in between. The cooling unit 2 extends in the direction of the tube axis of the barrier discharge lamp 1. The length of the cooling unit 2 in the direction of the tube axis can be, for example, the same as the length of the external electrode 16 (electrode body 16a) in the direction of the tube axis. At least one cooling unit 2 can be provided. If multiple cooling units 2 are provided, as shown in Figure 1, the multiple cooling units 2 can be arranged in a line along the direction of the tube axis of the barrier discharge lamp 1.

[0062] As shown in Figure 3, a recess 2a can be provided on one surface of the cooling section 2. The recess 2a extends in the direction of the tube axis of the discharge tube 11. Inside the recess 2a, the electrode body 16a of the external electrode 16 and the discharge tube 11 of the barrier discharge lamp 1 can be provided. At least a portion of the inner surface of the recess 2a can be in contact with the electrode body 16a.

[0063] Multiple mounting portions 16b of the external electrode 16 are attached to the surface of the cooling unit 2 where the recess 2a opens. Furthermore, if a positioning member 16c is provided, the positioning member 16c can be placed between the surface of the cooling unit 2 where the recess 2a opens and each of the multiple mounting portions 16b.

[0064] The cooling section 2 is formed from a material with high thermal conductivity. For example, the cooling section 2 can be made from a metal such as aluminum or stainless steel. Furthermore, as shown in Figure 3, a flow path 2b for circulating a refrigerant can be provided inside the cooling unit 2. The refrigerant can be, for example, water. By circulating a refrigerant inside the flow path 2b, heat dissipation can be improved.

[0065] Socket 3 is electrically connected to, for example, a lighting circuit. The lead wires 15 and external electrodes 16 are electrically connected to socket 3 in a detachable manner. Therefore, by electrically connecting the lead wires 15 and external electrodes 16 to socket 3, the internal electrodes 12 and external electrodes 16 can be electrically connected to a lighting circuit or the like.

[0066] The lighting circuit includes, for example, an inverter that converts power from an AC power source into high-voltage, high-frequency power (for example, a sine wave with a frequency of 37 kHz). For example, the lighting circuit lights up the barrier discharge lamp 1 with a lamp power of approximately 2.4 kW.

[0067] Case 4 is box-shaped and houses the barrier discharge lamp 1, cooling unit 2, and socket 3 inside. An opening is provided on one side of case 4 so that ultraviolet light emitted from the barrier discharge lamp 1 is irradiated to the outside. The lighting circuit can be installed inside case 4 or outside case 4.

[0068] Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Furthermore, the embodiments described above can be implemented in combination with each other. [Explanation of Symbols]

[0069] 1 barrier discharge lamp, 2 cooling unit, 11 discharge tube, 12 internal electrode, 12a coil, 13 reflective film, 16 external electrode, 16a electrode body, 16b mounting part, 16c positioning member, 100 ultraviolet irradiation device

Claims

1. A light-emitting tube extending in a first direction, having a cylindrical shape, and with gas sealed in its internal space; An internal electrode provided inside the light-emitting tube; An external electrode provided outside the aforementioned light-emitting tube; A cooling portion having a recess extending in the first direction; It is equipped with, The aforementioned external electrode is An electrode body is provided between the outer surface of the light-emitting tube and the inner surface of the recess of the cooling section, and is facing the internal electrode; In a second direction perpendicular to the first direction, a plurality of mounting portions are provided at each of the ends on both sides of the electrode body; It has, The length of the discharge tube and the length of the electrode body in the first direction are 600 mm or more. The plurality of mounting portions are attached to the surface of the cooling portion where the recess opens, arranged in the first direction. An ultraviolet irradiation device in which the distance between the centers of the multiple mounting parts is 30 mm or more and 150 mm or less.

2. It has a plate-like shape and is provided between the mounting portion and the surface of the cooling portion where the recess opens. The ultraviolet irradiation device according to claim 1, further comprising a positioning member for regulating the position of the electrode body and the position of the discharge tube in a second direction perpendicular to the first direction.

3. The ultraviolet irradiation device according to claim 2, wherein the length of the positioning member in the first direction is 5 mm or more and 20 mm or less.

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