TW202420397A - Ultraviolet irradiation device - Google Patents

Abstract

The utility model provides an ultraviolet irradiation device which can restrain and block reduction of uniformity in the tube axis direction of a discharge lamp. An ultraviolet irradiation device according to an embodiment comprises: a box-shaped housing having one end open; a blocking discharge lamp which is arranged in the frame body and can irradiate ultraviolet rays; and a gas flow forming part which is arranged in the frame body and enables purge gas to flow towards the blocking discharge lamp. The barrier discharge lamp is provided with: a ring-shaped light-emitting tube which extends in one direction and in which a gas is sealed; the internal electrode is arranged in the light-emitting tube; and the external electrode is arranged outside the light-emitting tube. The gas flow forming portion forms a flow of the purge gas flowing in the vicinity of an end portion of the light emitting tube on a side facing the opening of the frame.

Description

UV irradiation device

The embodiment of the present invention relates to an ultraviolet irradiation device.

There is an ultraviolet irradiation device, which includes a shielded discharge lamp that irradiates ultraviolet rays. The ultraviolet irradiation device including the shielded discharge lamp is used, for example, for surface treatment such as removal of organic matter attached to the surface of an object (photocleaning treatment), surface modification, and formation of an oxide film. The shielded 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, a dielectric shielding discharge is generated, thereby irradiating ultraviolet rays having a specific wavelength corresponding to the type of gas sealed inside the light-emitting tube.

Here, when the treatment using ultraviolet rays is performed, gas may be released from the object. For example, when the surface of the object contains organic matter, the organic matter may be decomposed by irradiation with ultraviolet rays, thereby releasing gas containing components of the organic matter. In addition, when a volatile material is applied to the surface of the object, gas containing components of the volatile material may be released. When the released gas reaches the shield discharge lamp, the components contained in the gas adhere to the surface of the shield discharge lamp, and the uniformity of the shield discharge lamp in the tube axis direction may decrease. If the uniformity decreases, uneven treatment is likely to occur, so the quality of the treated object may decrease.

Therefore, a technique has been proposed in which a shielding discharge lamp is installed inside a box-shaped frame having one end opened, and the inside of the box-shaped frame is purged with nitrogen gas. If the shielding discharge lamp is installed in a space filled with nitrogen gas, even if gas is released from the object, it is possible to suppress the released gas from reaching the shielding discharge lamp.

However, when the treatment time is long or the number of treatments is large, the released gas may reach the shield discharge lamp over time. Also, when the amount of gas released is large, the released gas may reach the shield discharge lamp. Therefore, even if the periphery of the shield discharge lamp is simply filled with nitrogen, the uniformity of the shield discharge lamp in the tube axis direction may decrease.

Therefore, it is desirable to develop an ultraviolet irradiation device that can suppress the decrease in uniformity in the tube axis direction of a shielded discharge lamp. [Prior art literature] [Patent literature]

[Patent Document 1] Japanese Patent Publication No. 2013-191758

[The problem that the invention wants to solve]

The problem to be solved by the present invention is to provide an ultraviolet irradiation device capable of suppressing the decrease in uniformity in the tube axis direction of a shielded discharge lamp. [Means for solving the problem]

The ultraviolet irradiation device of the embodiment includes: a frame body, which is box-shaped and has an opening at one end; a shielded discharge lamp, which is arranged inside the frame body and can irradiate ultraviolet rays; and an airflow forming part, which is inside the frame body and allows the blowing gas to flow toward the shielded discharge lamp. The shielded discharge lamp has: a light-emitting tube, which extends in one direction, is ring-shaped, and has gas sealed inside; an internal electrode, which is arranged inside the light-emitting tube; and an external electrode, which is arranged outside the light-emitting tube. The airflow forming part forms the flow of the blowing gas flowing near the end of the light-emitting tube on the side opposite to the opening of the frame body. [Effect of the invention]

According to the embodiment of the present invention, an ultraviolet irradiation device capable of suppressing a decrease in uniformity in the tube axial direction of a shielded discharge lamp can be provided.

Hereinafter, the embodiment will be illustrated with reference to the accompanying drawings. In addition, in each of the accompanying drawings, the same symbols are attached to the same structural components and detailed descriptions are appropriately omitted. In addition, arrows X, Y, and Z in each of the accompanying drawings represent three directions that are orthogonal to each other. For example, the direction orthogonal to the tube axis direction of the shielded discharge lamp 1 (luminous tube 11) is set as the X direction, the tube axis direction of the shielded discharge lamp 1 (luminous tube 11) is set as the Y direction, and the irradiation direction of ultraviolet rays is set as the Z direction.

Fig. 1 is a schematic cross-sectional view of an ultraviolet irradiation device 100 for illustrating the present embodiment. In Fig. 1, a case where one shielding discharge lamp 1 is provided is illustrated, but the number of shielding discharge lamps 1 can be appropriately changed according to the purpose of the shielding discharge lamps 1 or the size of the object 200 to be processed. That is, at least one shielding discharge lamp 1 only needs to be provided.

In addition, as shown in FIG. 1 , the ultraviolet irradiation device 100 (shielded discharge lamp 1) is provided on the side in the gravity direction of the object 200. At this time, the object 200 can be moved relative to the ultraviolet irradiation device 100 (shielded discharge lamp 1). For example, the object 200 can be moved in a predetermined direction using a conveyor 201 such as a conveyor. In addition, the ultraviolet irradiation device 100 (shielded discharge lamp 1) can also be moved relative to the object 200. For example, the object 200 can be placed on a stage or the like, and the ultraviolet irradiation device 100 (shielded discharge lamp 1) can be moved in a predetermined direction using a single-axis robot or the like.

That is, the relative position between the ultraviolet irradiation device 100 (shielded discharge lamp 1) and the object 200 may be changed. In addition, the position between the ultraviolet irradiation device 100 (shielded discharge lamp 1) and the object 200 may be constant. However, if the relative position between the ultraviolet irradiation device 100 (shielded discharge lamp 1) and the object 200 is changed, the irradiation area of the ultraviolet irradiation device 100 (shielded discharge lamp 1) can be reduced, so that the ultraviolet irradiation device 100 (shielded discharge lamp 1) can be miniaturized or energy-saving.

As shown in FIG1 , the ultraviolet irradiation device 100 includes, for example, a shielded discharge lamp 1, a cooling unit 2, a lamp holder 3, a cover 4, a frame 5, and a purge gas supply unit 6. FIG2 is a schematic exploded view of the shielded discharge lamp 1, the cooling unit 2, the lamp holder 3, and the cover 4. FIG3 is a schematic diagram for illustrating the shielded discharge lamp 1. FIG4 is a schematic cross-sectional view of the shielded discharge lamp 1 in the A-A line direction in FIG3 . In addition, the cooling unit 2 is also depicted in FIG4 . As shown in FIG3 and FIG4 , the shielded discharge lamp 1 includes, for example, a light-emitting tube 11, an internal electrode 12, a reflective film 13, a bracket 14, a wire 15, and an external electrode 16.

The light-emitting tube 11 is in a tubular shape, and has a shape in which the total length (length in the tube axis direction) is longer than the tube diameter. The light-emitting tube 11 extends in one direction (Y direction). The light-emitting tube 11 can be set as a cylindrical tube, for example. Sealing parts 11a are respectively provided at both end parts in the tube axis direction of the light-emitting tube 11. By providing the sealing parts 11a, the internal space of the light-emitting tube 11 can be hermetically sealed. The sealing parts 11a can be formed, for example, using a pinch seal method or a shrink seal method.

Furthermore, a conductive portion 11b and an outer lead 11c may be provided inside the sealing portion 11a. One conductive portion 11b may be provided for each sealing portion 11a. The plane shape of the conductive portion 11b is, for example, a quadrangle. The conductive portion 11b is in a thin film shape. The conductive portion 11b may be formed of, for example, molybdenum foil.

The outer lead 11c is linear and can be provided at least on one side of the sealing portion 11a provided with the lead 15. 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 includes, for example, molybdenum.

Gas is sealed in the internal space of the light-emitting tube 11. In the shielded discharge lamp 1, shielded discharge is performed between the internal electrode 12 and the external electrode 16, and high-energy electrons are given to the sealed gas to generate excimer excited molecules. When the excimer excited molecules are reduced, light with a specific peak wavelength is generated corresponding to the type of gas. Therefore, the gas sealed in the internal space of the light-emitting tube 11 can be appropriately changed according to the purpose of the shielded discharge lamp 1. The gas sealed in the internal space of the light-emitting tube 11 can be, for example, a rare gas such as krypton, xenon, argon, neon, or a mixed gas formed by mixing multiple rare gases. Halogen gas or the like can also be further included in the gas as needed.

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

For example, when the surface of a glass plate for a flat panel display is optically cleaned, it is preferred that the sealed gas be xenon. In this case, the sealing pressure of xenon can be set to, for example, about 93 kPa. If the sealed gas is xenon, ultraviolet light with a peak wavelength of 172 nm can be generated, thereby improving the cleaning effect.

The light-emitting tube 11 is formed of a material having a high transmittance of ultraviolet light having a peak wavelength of 200 nm or less, for example, or can be formed of synthetic quartz glass.

The internal electrode 12 is provided inside the light-emitting tube 11. The internal electrode 12 includes, for example, a coil 12a and an electrode 12b. The coil 12a and the electrode 12b may be formed integrally. The coil 12a and the electrode 12b are formed, for example, by plastic working a wire. The wire diameter (diameter) of the wire is, for example, about 0.2 mm to 1.0 mm. The material of the wire is, for example, tungsten or doped tungsten obtained by adding potassium to tungsten.

The coil 12a is spirally shaped and is disposed in the inner space of the light-emitting tube 11. The coil 12a extends along the tube axis of the light-emitting tube 11 in the central region of the inner space of the light-emitting tube 11. The pitch dimension P of the coil 12a can be set to about 10 mm to 120 mm, for example.

The poles 12b are respectively arranged at the ends of the coil 12a on both sides. The poles 12b are linear and extend from the ends of the coil 12a along the tube axis of the light-emitting tube 11. The ends of the poles 12b are electrically connected to the conductive part 11b inside the sealing part 11a. The ends of the poles 12b can be laser welded or resistance welded to the conductive part 11b.

The reflective film 13 may be provided between the external electrode 16 and the internal electrode 12 (coil 12a). For example, the reflective film 13 is in the form of a film and is provided on the inner wall of the light-emitting tube 11. The reflective film 13 reflects the ultraviolet rays generated in the inner space of the light-emitting tube 11 and not directed in the irradiation direction toward the irradiation direction. If the reflective film 13 is provided, the extraction efficiency of the ultraviolet rays can be improved. Furthermore, if the reflective film 13 is provided, the area of the light-emitting tube 11 where the ultraviolet rays directly enter can be reduced, thereby suppressing the chemical structural changes of the light-emitting tube 11 caused by the ultraviolet rays.

The thickness of the reflective film 13 can be set to about 100 μm to 300 μm, for example. The reflective film 13 includes, for example, SiO ₂ . Furthermore, the reflective film 13 may include particles that scatter ultraviolet rays. The particles that scatter ultraviolet rays include, for example, aluminum oxide.

The reflective film 13 is not necessarily required and can be omitted. However, if the reflective film 13 is provided, the efficiency of extracting ultraviolet rays can be improved and chemical structural changes of the light-emitting tube 11 caused by ultraviolet rays can be suppressed.

The brackets 14 are respectively provided at the ends of both sides of the light-emitting tube 11 in the tube axis direction. The brackets 14 cover the ends of the light-emitting tube 11. The brackets 14 can be formed of, for example, an insulating material. The brackets 14 can be formed of, for example, steatite, alumina, etc. The brackets 14 can be in contact with the external electrode 16 or separated from the external electrode 16.

The lead wire 15 is electrically connected to the end of the outer lead wire 11c exposed from the sealing portion 11a. The lead wire 15 is electrically connected to the internal electrode 12 via the outer lead wire 11c and the conductive portion 11b. The lead wire 15 is electrically connected to a lighting circuit provided outside the ultraviolet irradiation device 100, for example. In addition, the lead wire 15 may be provided only at one end side of the light-emitting tube 11 as shown in FIG. 3 , or may be provided at both end sides of the light-emitting tube 11.

As shown in Fig. 2 to Fig. 4, the external electrode 16 is provided outside the light-emitting tube 11. The external electrode 16 includes, for example, an electrode body 16a and a plurality of mounting portions 16b. The electrode body 16a and the plurality of mounting portions 16b may be formed integrally.

The electrode 16a extends along the outer surface of the light-emitting tube 11 and in the tube axis direction of the light-emitting tube 11. The electrode 16a is provided between the outer surface of the light-emitting tube 11 and the inner wall of the recess 2a of the cooling unit 2. The electrode 16a faces the inner electrode 12 (coil 12a). When the reflective film 13 is provided, the electrode 16a may be provided at a position facing the reflective film 13.

The thickness of the electrode 16a can be set to, for example, 0.1 mm or more and 1.0 mm or less. The electrode 16a can be formed of a conductive material such as metal. The electrode 16a is formed of, for example, stainless steel, aluminum, etc. Moreover, when the shielding discharge lamp 1 is lit, heat is generated together with ultraviolet rays. Therefore, if the electrode 16a includes a material with high thermal conductivity such as metal, the electrode 16a can also be used as a heat sink.

The plurality of mounting portions 16b are respectively provided at both side ends of the electrode body 16a in a direction perpendicular to the tube axis direction of the light-emitting tube 11. One end of the plurality of mounting portions 16b is provided at the end of the electrode body 16a. In a direction perpendicular to the tube axis direction of the light-emitting tube 11, the plurality of mounting portions 16b extend in a direction away from the light-emitting tube 11.

The plurality of mounting parts 16b are arranged along the tube axis direction of the light-emitting tube 11. The plurality of mounting parts 16b are mounted on the surface of the cooling part 2 where the recessed part 2a is opened. The plurality of mounting parts 16b are mounted on the cooling part 2 using a fastening member such as a screw. The thickness and material of the plurality of mounting parts 16b can be set to be the same as that of the electrode body 16a.

If a plurality of mounting portions 16b are mounted on the cooling portion 2, deformation of the electrode body 16a due to heat generated when the shield discharge lamp 1 is turned on can be suppressed. If deformation of the electrode body 16a can be suppressed, the phenomenon that the discharge state changes due to a change in the distance between the internal electrode 12 (coil 12a) and the external electrode 16 (electrode body 16a) can be suppressed. If the change in the discharge state can be suppressed, uniformity can be improved. Therefore, the occurrence of uneven processing can be suppressed.

Furthermore, a plurality of positioning members 16c may be provided. The positioning member 16c is plate-shaped and may be provided between the mounting portion 16b and the surface of the cooling portion 2 on which the recessed portion 2a is provided. For example, the number of positioning members 16c may be the same as the number of mounting portions 16b.

The positioning member 16c is mounted on the cooling unit 2 together with the mounting portion 16b using a fastening member such as a screw. Therefore, a hole penetrating the thickness direction can be provided in the positioning member 16c. The thickness of the positioning member 16c can be set to about 0.3 mm, for example. The material of the positioning member 16c can be set to a metal such as stainless steel, for example.

When the positioning member 16c is mounted on the cooling unit 2, a small gap may be provided at least at any one of the ends of the positioning member 16c and the electrode 16a and between the electrode 16a and the outer surface of the light-emitting tube 11, or no gap may be provided. In this way, the electrode 16a and the light-emitting tube 11 can be prevented from being deformed by the heat generated when the shielded discharge lamp 1 is lit. Therefore, the discharge state may be changed due to the change in the distance between the internal electrode 12 (coil 12a) and the external electrode 16 (electrode 16a), or the cooling state may be changed due to the gap between the light-emitting tube 11 and the cooling unit 2. If the change in the discharge state and the cooling state can be suppressed, the uniformity can be further improved. Therefore, the occurrence of uneven processing can be further suppressed.

As shown in FIG. 2 and FIG. 4 , the cooling part 2 faces the light-emitting tube 11 with the external electrode 16 interposed therebetween. The cooling part 2 extends along the tube axis direction of the shielded discharge lamp 1. The length of the cooling part 2 in the tube axis direction can be set to be the same as the length of the external electrode 16 (electrode body 16a) in the tube axis direction, for example. At least one cooling part 2 can be provided. When a plurality of cooling parts 2 are provided, as shown in FIG. 2 , the plurality of cooling parts 2 can be arranged in a row along the tube axis direction of the shielded discharge lamp 1.

As shown in FIG4 , a recess 2a may be provided on one surface of the cooling portion 2. The recess 2a extends along the tube axis direction of the light-emitting tube 11. An electrode body 16a of the external electrode 16 and the light-emitting tube 11 of the shielded discharge lamp 1 may be provided inside the recess 2a. At least a portion of the inner surface of the recess 2a may be in contact with the electrode body 16a.

The cooling part 2 is formed of a material with high thermal conductivity. The cooling part 2 can be formed of a metal such as aluminum or stainless steel, for example. In addition, as shown in FIG. 4 , a flow path 2b can be provided inside the cooling part 2. For example, a refrigerant is supplied to the flow path 2b via an on-off valve 2c. The refrigerant is, for example, water. The refrigerant flowing inside the flow path 2b is discharged to the outside of the cooling part 2. If the refrigerant is made to flow inside the flow path 2b, the heat generated in the shielded discharge lamp 1 can be efficiently dissipated.

The lamp holder 3 is electrically connected to, for example, a lighting circuit. The lead wire 15 and the external electrode 16 are electrically connected to the lamp holder 3 in a detachable manner. By electrically connecting the lead wire 15 and the external electrode 16 to the lamp holder 3, the internal electrode 12 and the external electrode 16 can be electrically connected to the lighting circuit.

The lighting circuit includes, for example, an inverter that converts power from an AC power source into power of high voltage and high frequency (for example, a sine wave with a frequency of 37 kHz). For example, the lighting circuit lights the shielding discharge lamp 1 with a lamp power of about 2.4 kW.

The cover 4 is box-shaped and contains the shielding discharge lamp 1, the cooling unit 2 and the lamp holder 3. One end of the cover 4 is open. If the cover 4 is provided, the purge gas G described later can be retained in the inner space of the cover 4. If the purge gas G is retained in the inner space of the cover 4, the shielding discharge lamp 1 can be protected.

The frame 5 is box-shaped and contains the shielding discharge lamp 1, the cooling unit 2, the lamp holder 3 and the cover 4. One end of the frame 5 is open. The direction in which the opening of the frame 5 is provided can be set to be the same as the direction in which the opening of the cover 4 is provided. As shown in FIG. 1 , the ultraviolet rays irradiated from the shielding discharge lamp 1 are irradiated to the object 200 through the opening of the cover 4 and the opening of the frame 5.

The purge gas G supplied from the purge gas supply unit 6 is retained in the internal space of the housing 5. When the internal space of the housing 5 is filled with the purge gas G, the gas 200a including the components of the object 200 emitted from the object 200 can be prevented from reaching the shield discharge lamp 1 (luminous tube 11).

FIG5 is a schematic cross-sectional view of an ultraviolet irradiation device 300 for illustrating a comparative example. As shown in FIG5 , the ultraviolet irradiation device 300 has a shielded discharge lamp 1, a cooling unit 2, a lamp holder 3, a cover 4, a frame 5, and a purge gas supply unit 306. The purge gas supply unit 306 supplies the purge gas G to the inner space of the frame 5 through a flow regulating valve 306a, for example. The purge gas G supplied to the inner space of the frame 5 is retained in the inner space of the frame 5, and a portion is discharged to the outside from the opening of the frame 5.

If the purge gas G is retained in the internal space of the frame 5, as shown in FIG5, a layer 306b of the purge gas G is formed between the shield discharge lamp 1 (luminous tube 11) and the object 200. If the layer 306b of the purge gas G is formed, it is possible to suppress the gas 200a emitted from the object 200 from reaching the shield discharge lamp 1 (luminous tube 11). Therefore, it is possible to suppress the components of the object 200 from adhering to the surface of the shield discharge lamp 1 (luminous tube 11) and causing the uniformity of the shield discharge lamp 1 in the tube axis direction to decrease.

However, when the processing time is long or the number of processing is large, the gas 200a may reach the shield discharge lamp 1 (luminous tube 11) as time passes. In addition, when the emission amount of the gas 200a is large, the gas 200a may reach the shield discharge lamp 1 (luminous tube 11). When the gas 200a reaches the shield discharge lamp 1 (luminous tube 11), the components of the object 200 may adhere to the surface of the shield discharge lamp 1 (luminous tube 11) and the uniformity of the shield discharge lamp 1 in the tube axis direction may decrease. If the uniformity decreases, uneven processing is likely to occur, so the quality of the object 200 subjected to the processing may be reduced.

Therefore, the ultraviolet irradiation device 100 of the present embodiment is provided with a purge gas supply unit 6. As shown in FIG1 , the purge gas supply unit 6 has, for example, a gas supply source 6a, an on-off valve 6b, a flow rate adjustment unit 6c, and an airflow forming unit 6d. The gas supply source 6a, the on-off valve 6b, and the flow rate adjustment unit 6c may be provided outside the frame 5. The airflow forming unit 6d may be provided in the internal space of the frame 5.

The gas supply source 6a supplies the purge gas G to the gas flow forming portion 6d. The gas supply source 6a can be, for example, a high-pressure gas cylinder storing the purge gas G or a factory pipe.

The purge gas G is not particularly limited as long as it is a gas that does not easily react with the object 200 and the parts of the shielded discharge lamp 1. The purge gas G can be, for example, a rare gas such as nitrogen, argon or helium. At this time, if the purge gas G is set to a gas with a smaller specific gravity than air (such as helium), it is easy to make the purge gas G stagnate in the internal space of the frame 5. In addition, if the purge gas G is set to nitrogen, which is cheaper than rare gases, it is possible to reduce operating costs.

The on-off valve 6b may be connected between the gas supply source 6a and the gas flow forming portion 6d via a pipe or the like. The on-off valve 6b controls the supply and stop of the purge gas G. The on-off valve 6b may be, for example, a two-way valve.

The flow regulating section 6c can be connected between the on-off valve 6b and the airflow forming section 6d via piping or the like. The flow regulating section 6c regulates the flow rate of the purge gas G. The flow regulating section 6c can be, for example, a flow regulating valve or a pressure regulating valve. Moreover, the flow regulating section 6c can also have the function of the on-off valve 6b. The airflow forming section 6d can be connected to the flow regulating section 6c, for example, via piping or the like. FIG. 6 is a schematic three-dimensional diagram for illustrating the airflow forming section 6d. As shown in FIG. 1 and FIG. 6, the airflow forming section 6d can be arranged in parallel with the shielded discharge lamp 1 (luminous tube 11) in a direction (X direction) orthogonal to the tube axis direction of the shielded discharge lamp 1 (luminous tube 11). The airflow forming section 6d can be arranged in parallel with the shielded discharge lamp 1 (luminous tube 11). In the tube axis direction (Y direction) of the shielded discharge lamp 1 (light-emitting tube 11), the length of the airflow forming portion 6d can be set to be the same as the length of the shielded discharge lamp 1.

As shown in FIG6 , the air flow forming portion 6d may be provided with a blow-out port 6d1 for blowing the sweeping gas G. The blow-out port 6d1 may be, for example, a slit extending along the tube axis direction (Y direction) of the shielded discharge lamp 1 (flash tube 11). Alternatively, a plurality of holes arranged along the tube axis direction (Y direction) of the shielded discharge lamp 1 (flash tube 11) may be provided as the blow-out port 6d1.

As shown in FIG. 1 and FIG. 6 , the blowing gas G supplied to the airflow forming section 6d is blown out from the blowing port 6d1. The blowing gas G blown out from the blowing port 6d1 is supplied to the vicinity of the end of the light-emitting tube 11 on the object 200 side. That is, the airflow forming section 6d causes the blowing gas G to flow toward the shielded discharge lamp 1 (light-emitting tube 11) inside the frame 5. At this time, as shown in FIG. 1 , the airflow forming section 6d forms a flow of the blowing gas G flowing near the end of the light-emitting tube 11 on the side facing the opening of the frame 5 (the side facing the object 200). The blowing gas G flows along the opening of the frame 5 from one side of the light-emitting tube 11 to the other side in a direction (X direction) orthogonal to the direction in which the light-emitting tube 11 extends. If such a flow of the purge gas G is formed, the gas 200a from the object 200 toward the shield discharge lamp 1 (flash tube 11) can be moved away from the shield discharge lamp 1 (flash tube 11) along with the flow of the purge gas G.

The flow rate or flow rate of the purge gas G blown out from the blow outlet 6d1 is not particularly limited as long as it is a flow rate or flow rate at which the gas 200a is far away from the shielding discharge lamp 1 (luminous tube 11). At this time, if the flow rate of the purge gas G is increased or the flow rate of the purge gas G is increased, it is difficult for the gas 200a to reach the shielding discharge lamp 1 (luminous tube 11). On the other hand, if the flow rate of the purge gas G is increased or the flow rate of the purge gas G is increased, the operating cost will increase. Therefore, the flow rate or flow rate of the purge gas G can be appropriately changed according to the emission amount of the gas 200a, the distance between the shielding discharge lamp 1 (luminous tube 11) and the object 200, etc. The flow rate or flow rate of the purge gas G can be appropriately determined by conducting experiments or simulations.

If the airflow forming portion 6d is provided, it is possible to effectively prevent the components of the object 200 from adhering to the surface of the shield discharge lamp 1 (luminous tube 11). Therefore, it is possible to prevent the uniformity of the shield discharge lamp 1 in the tube axis direction from decreasing, thereby preventing the occurrence of uneven processing.

FIG7 is a schematic three-dimensional diagram of an airflow forming portion 6da for illustrating another embodiment. The airflow forming portion 6da can be, for example, an air supply fan. In this case, as shown in FIG7 , a plurality of airflow forming portions 6da can be arranged along the tube axis direction (Y direction) of the shielded discharge lamp 1 (luminous tube 11). The row of the plurality of airflow forming portions 6da can be arranged to be parallel to the shielded discharge lamp 1 (luminous tube 11). In addition, the number of airflow forming portions 6da is not limited to the number illustrated, and for example, it can be appropriately changed according to the length in the tube axis direction of the shielded discharge lamp 1 (luminous tube 11). In addition, the airflow forming portion 6da can also be a cross-flow fan (line flow fan (registered trademark)). When the airflow forming portion 6da is set as a cross-flow fan, for example, an airflow forming portion 6da extending along the tube axis direction (Y direction) of the shielded discharge lamp 1 (light-emitting tube 11) can be set.

Furthermore, the airflow forming portion 6da supplies the blowing gas G retained in the internal space of the frame 5 to the vicinity of the end of the light-emitting tube 11 on the object 200 side. Therefore, the flow adjusting portion 6c is connected to the internal space of the frame 5. The flow adjusting portion 6c supplies the blowing gas G to the internal space of the frame 5 so that the blowing gas G exists at least around the airflow forming portion 6da.

When the airflow forming portion 6da is provided, a flow of the sweeping gas G can also be formed near the end of the flash tube 11 on the object 200 side. If the flow of the sweeping gas G is formed, the gas 200a from the object 200 toward the shield discharge lamp 1 (flash tube 11) can be moved away from the shield discharge lamp 1 (flash tube 11) along with the flow of the sweeping gas G. That is, if the airflow forming portion 6da is provided, the same effect as that of the airflow forming portion 6d can be achieved.

FIG8 is a table for illustrating the effect of the ultraviolet irradiation device 300 of the comparative example shown in FIG5. In addition, FIG8 is a table for illustrating the effect when the airflow forming section 6d (6da) is not provided. FIG9 is a table for illustrating the effect when the airflow forming section 6d (6da) is provided. In addition, "0 mm" in FIG8 and FIG9 represents the center position in the tube axis direction (Y direction) of the shielded discharge lamp 1 (light-emitting tube 11). Moreover, "300 mm", "600 mm", "700 mm", "-300 mm", "-600 mm", and "-700 mm" represent the distance from the center position. FIG10 is a graph for illustrating the change of uniformity over time.

As can be seen from Fig. 8 and Fig. 9, if the airflow forming portion 6d (6da) is provided, the variation in the illuminance in the tube axis direction (Y direction) of the muffled discharge lamp 1 (luminous tube 11) can be reduced. That is, the uniformity can be improved.

Moreover, as can be seen from FIG. 10 , if the airflow forming section 6d (6da) is provided, the uniformity can be suppressed from decreasing over time. Moreover, since the purge gas G is directly supplied to the vicinity of the shield discharge lamp 1 (luminous tube 11), it is possible to effectively suppress the contact between the external gas (air) and the shield discharge lamp 1 (luminous tube 11). For example, when shield discharge occurs between the internal electrode 12 and the electrode 16a, if air in the environment exists in the gap between the electrode 16a and the cooling section 2 or the gap between the electrode 16a and the luminous tube 11, hydrogen nitrate gas may be generated. Moreover, moisture in the environment may condense on the surface of the electrode 16a. If hydrogen nitrate gas dissolves in condensed water, nitric acid will be generated. When nitric acid contacts the outer surface of the light-emitting tube 11, the transmittance of ultraviolet rays will decrease. If this chemical reaction is repeated every time the shielded discharge lamp 1 is lit, the efficiency of ultraviolet light extraction may decrease over time.

If the airflow forming section 6d (6da) is provided, the purge gas G is directly supplied to the vicinity of the shield discharge lamp 1 (luminous tube 11), so that the generation of hydrogen nitrate gas or condensation of water can be effectively suppressed. Therefore, the reduction in ultraviolet light extraction efficiency over time can be effectively suppressed.

Furthermore, if the cover 4 is provided, the purge gas G supplied to the vicinity of the shielded discharge lamp 1 (luminous tube 11) can be retained, thereby further suppressing the generation of hydrogen nitrate gas or condensation of water. Therefore, the reduction in ultraviolet light extraction efficiency over time can be further suppressed.

Several embodiments of the present invention are illustrated above, but these embodiments are provided as examples 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, changes, etc. can be made without departing from the scope of the invention. These embodiments or their variations are included in the scope or the subject matter of the invention, and are included in the invention described in the claims and the scope of their equivalents. Moreover, the aforementioned embodiments can be implemented in combination with each other.

1: Shielded discharge lamp 2: Cooling part 2a: Recessed part 2b: Flow path 2c, 6b: On/off valve 3: Lamp holder 4: Cover 5: Frame 6, 306: Blowing gas supply part 6a: Gas supply source 6c: Flow rate adjustment part 6d, 6da: Air flow forming part 6d1: Blowing outlet 11: Light-emitting tube 11a: Sealing part 11b: Conductive part 11c: External lead 12: Internal electrode 12a: Coil 12b: Electrode 13: Reflective film 14: Bracket 15: Wire 16: External electrode 16a: Electrode body 16b: Mounting part 16c: Positioning member 100: UV irradiation device 200: Object 200a: Gas 201: Transport device 306a: Flow control valve 306b: Layer A-A: Line G: Blowing gas P: Pitch size X, Y, Z: Arrows

FIG. 1 is a schematic cross-sectional view of an ultraviolet irradiation device for illustrating the present embodiment. FIG. 2 is a schematic exploded view of a shielded discharge lamp, a cooling unit, a lamp holder, and a cover. FIG. 3 is a schematic view for illustrating a shielded discharge lamp. FIG. 4 is a schematic cross-sectional view of the shielded discharge lamp in FIG. 3 along the A-A line. FIG. 5 is a schematic cross-sectional view of an ultraviolet irradiation device for illustrating a comparative example. FIG. 6 is a schematic three-dimensional view for illustrating an airflow forming unit. FIG. 7 is a schematic three-dimensional view for illustrating an airflow forming unit of another embodiment. FIG. 8 is a table for illustrating the effect of the ultraviolet irradiation device of the comparative example shown in FIG. 5. FIG. 9 is a table for illustrating the effect when an airflow forming unit is provided. FIG. 10 is a graph for illustrating the change of uniformity over time.

1: Shielding discharge lamp

2: Cooling section

2b: Flow path

3: Lamp holder

4: Hood

5: Frame

2c, 6b: Open/Close valve

6: Blowing gas supply unit

6a: Gas supply source

6c: Flow adjustment department

6d: Airflow formation part

16a: Electrode

16b: Installation Department

16c: Positioning components

100: Ultraviolet irradiation device

200: Object

200a: Gas

201: Transport device

G: Blowing gas

Claims (3)

A UV irradiation device, characterized in that it includes: a frame, which is box-shaped and has an opening at one end; a shielded discharge lamp, which is arranged inside the frame and irradiates UV rays; an airflow forming part, which makes a blowing gas flow toward the shielded discharge lamp inside the frame, the shielded discharge lamp has: a light-emitting tube, which extends in one direction, is tubular, and has a gas sealed inside; an internal electrode, which is arranged inside the light-emitting tube; and an external electrode, which is arranged outside the light-emitting tube, the airflow forming part forms the flow of the blowing gas flowing near the end of the light-emitting tube on the side opposite to the opening of the frame. An ultraviolet irradiation device as described in claim 1, wherein the purge gas is retained in the internal space of the frame. An ultraviolet irradiation device as described in claim 1 or claim 2, wherein the blowing gas flows along the opening of the frame from one side of the light-emitting tube to the other side in a direction orthogonal to the direction in which the light-emitting tube extends.