Excimer lamp

Abstract

The invention provides an excimer lamp. In a line irradiation type excimer lamp, light such as ultraviolet rays emitted from the inside of a discharge tube is efficiently irradiated toward an irradiation object. An outer surface (20S) of a discharge tube (20) of an excimer lamp (10) is covered by an outer electrode (40), and an outer surface portion not covered by the outer electrode (40) is configured as a window (20W) for light transmission. The foil electrode (30) is provided with wedge-shaped parts (34A, 34B) which are sharpened towards two ends (E1, E2) in the width direction, one end (E2) of the foil electrode (30) is opposite to the outer electrode (40), and one end (E1) of the foil electrode (30) is opposite to the window (20W).

Description

Technical Field

[0001] The present invention relates to an excimer lamp, and more particularly to an excimer lamp capable of efficiently irradiating light such as ultraviolet rays toward an irradiation object. Background Art

[0002] In an excimer lamp, an inner electrode is provided in a discharge tube filled with rare gas such as xenon or a mixed gas containing rare gas, and an outer electrode is provided on the outer surface of the discharge tube. A high-frequency voltage is applied between the inner electrode and the outer electrode to generate a discharge, and excimer light (ultraviolet light) is radiated from the discharge space.

[0003] The following excimer lamp is known: in order to irradiate light efficiently, the excimer lamp covers a part of the outer surface of the discharge tube with an outer electrode having a reflective property, and emits light from the light-transmitting part where the outer electrode is not provided. For example, a slit-shaped light-transmitting part is set along the lamp axis direction, and the outer surface part of the discharge tube other than this is covered with an outer electrode such as an aluminum reflective film (see Patent Document 1). Hereinafter, such an excimer lamp is referred to as a line irradiation type excimer lamp.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 7-272692 (FIG. 7, etc.)

[0005] In the case of a small linear excimer lamp (for example, a discharge tube having an outer diameter of several to several tens of mm), it is required to more efficiently irradiate light emitted from discharge in the discharge tube toward an irradiation object. Summary of the invention

[0006] The linear irradiation type excimer lamp as one embodiment of the present invention is configured as follows: a light emitting surface is provided along the lamp axis direction corresponding to a slit-shaped light-transmitting portion provided along the lamp axis direction. The excimer lamp comprises: a discharge tube; a dielectric covering an inner electrode extending in a strip shape in the discharge tube; and an outer electrode provided along the circumference of the outer surface of the discharge tube. For example, in order to perform linear light irradiation through the slit-shaped light emitting surface, the outer electrode may be provided in a part of the circumference of the outer surface of the discharge tube in an arc-shaped cross section. The configuration area of ​​the outer electrode along the circumference, that is, the light irradiation width, is arbitrary depending on the lamp size, light output, use environment, etc.

[0007] The structure of the inner electrode is various, for example, it can be configured as a foil electrode extending along the lamp axis direction. The foil electrode can be configured so that the two ends along the electrode width direction are thinner than the central part in the width direction of the foil electrode. For example, the foil electrode can be configured so that there is a flat portion with a substantially constant thickness along the width direction between the two ends along the width direction of the foil electrode, and the foil electrode is sharpened from the two ends of the flat portion toward the two ends along the width direction of the foil electrode.

[0008] In the excimer lamp of the present invention, at least one end of the strip-shaped inner electrode along the width direction is opposite to the outer electrode. For example, the outer electrode may be arranged so that the other end of the inner electrode along the width direction is opposite to the discharge surface of the discharge tube. Furthermore, the discharge surface of the discharge tube is formed symmetrically with the width direction of the inner electrode as the symmetry axis. That is, the outer electrode may be configured to be symmetrical with the width direction of the inner electrode as the symmetry axis.

[0009] The dielectric can be configured in various shapes. For example, the inner electrode and the dielectric can be coaxially arranged, and the distance between the outer surface of the dielectric and the inner electrode along the thickness direction of the inner electrode can be shorter than the distance between the outer surface of the dielectric and the inner electrode along the width direction of the inner electrode.

[0010] For example, in the case where the inner electrode is a foil electrode, the foil electrode may have a flat portion with a thickness substantially constant along the width direction formed between both ends of the foil electrode along the width direction, and the dielectric may have a thickness substantially constant along the width direction of the foil electrode, and an outer surface substantially parallel to the flat portion may be provided.

[0011] As a dielectric having such characteristics, for example, it can be configured to be flat in the width direction of the inner electrode. Here, "flat in the width direction of the inner electrode" means having a flat outer surface along the width direction of the strip-shaped inner electrode and flattened in the electrode thickness direction. In addition, the dielectric can be configured so that the cross section of the dielectric is oblong or oblong.

[0012] According to the present invention, in a linear irradiation type excimer lamp, light emitted by discharge in a discharge tube can be efficiently irradiated toward an irradiation object. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic cross-sectional view of the excimer lamp according to the present embodiment, taken along the electrode width direction.

[0014] Figure 2 This is a schematic cross-sectional view of the excimer lamp according to the present embodiment, taken along the electrode thickness direction.

[0015] Figure 3 This is a top view of the excimer lamp as viewed from the radiating surface side.

[0016] Figure 4 It is along Figure 3 A cross-sectional view taken along line IV-IV.

[0017] Figure 5 is an enlarged cross-sectional view of the foil electrode.

[0018] Figure 6is an enlarged cross-sectional view of a foil electrode and a dielectric covering the foil electrode.

[0019] Description of symbols

[0020] 10: Excimer lamp; 20: discharge tube; 30: foil electrode; 40: outer electrode; 50: dielectric. DETAILED DESCRIPTION

[0021] Hereinafter, the excimer lamp according to the present embodiment will be described with reference to the drawings.

[0022] Figure 1 This is a schematic cross-sectional view of an excimer lamp along the electrode width direction. Figure 2 This is a schematic cross-sectional view of an excimer lamp along the electrode thickness direction. Figure 3 This is a top view of the excimer lamp as viewed from the irradiation surface side. Figure 4 It is along Figure 3 A cross-sectional view taken along line IV-IV.

[0023] The excimer lamp 10 is a line irradiation type excimer lamp that emits light from a light-transmitting portion set along the lamp axis. The excimer lamp 10 has a bottomed cylindrical discharge tube (discharge container) 20 made of a dielectric material such as quartz glass, and a window 20W serving as a light emission surface (exit surface) is formed on a part of the cylindrical side surface of the bottomed cylindrical discharge tube 20.

[0024] Here, the discharge tube 20 is a discharge tube having a circular cross section along the tube diameter (lamp diameter) direction, and is configured to have a constant inner diameter and thickness along the tube axis (lamp axis) C. A rare gas such as xenon or a mixed gas thereof is sealed in a discharge space S in the discharge tube 20 as a discharge gas.

[0025] An electrode (inner electrode) extending in a strip shape along the tube axis C is arranged in the discharge tube 20. Here, the foil electrode 30 is arranged along the tube axis C. The foil electrode 30 is covered (sealed) by a columnar dielectric 50 made of quartz glass or the like, and is not exposed to the discharge space S, but is buried in the dielectric 50. One end 30T of the foil electrode 30 along the lamp axis C is connected to a power supply line (power supply rod) 60, and the power supply line 60 is connected to a power supply unit (not shown) provided outside.

[0026] The dielectric 50 is welded to the discharge tube 20 at a flange portion (hereinafter referred to as a weld portion) 52 protruding radially in a flange shape to form the inner tube of the double-tube type excimer lamp 10. The outer diameter of the weld portion 52 of the dielectric 50 is set according to the inner diameter D1 of the discharge tube 20.

[0027] like Figure 4As shown in FIG. 1 , the foil electrode 30 is coaxially arranged with the discharge tube 20, and the dielectric 50 is also coaxially arranged with the discharge tube 20. Therefore, the foil electrode 30 is coaxially arranged in a state where the center position in the width direction and the thickness direction thereof coincides with the center position of the dielectric 50. Furthermore, the foil electrode 30 is arranged at a position symmetrical with respect to the tube axis C. Figure 1 to Figure 4 In the diagram, the width direction of the foil electrode 30 is defined as the Y direction, and the direction perpendicular thereto (thickness direction) is defined as the X direction.

[0028] An outer electrode 40 is provided on the outer surface 20S of the discharge tube 20. The outer electrode 40 is made of a material that reflects light emitted by the discharge generated in the discharge space S, for example, a film or plate having thermal conductivity and electrical conductivity. Here, the outer surface portion of the discharge tube 20 that is not covered by the outer electrode 40 is formed as a window 20W for light emission. The outer electrode 40 can be made of a film (such as an aluminum film) that reflects light including ultraviolet light having a wavelength of 172 nm, for example.

[0029] When a high-frequency voltage (for example, a voltage in the range of several kV to more than ten kV at a frequency of several kHz to several tens of MHz) is applied between the foil electrode 30 and the outer electrode 40, a dielectric barrier discharge is generated through the dielectric 50 covering the foil electrode 30 and the discharge tube 20 covered by the outer electrode, and excimer light of a specified spectrum (for example, a wavelength of 172 nm) is radiated from the discharge space S.

[0030] Light emitted from the discharge space S is emitted directly from the window 20W to the outside of the lamp or is emitted from the window 20W to the outside of the lamp by reflection from the outer electrode 40. By arranging the irradiation object close to the window 20W so as to face it, light irradiation and ultraviolet irradiation treatment can be performed.

[0031] The size of the small linear irradiation type excimer lamp 10 can be set according to the use environment, etc. For example, the axial length (luminous length) of the discharge generated in the discharge tube 20 can be set in the range of 20 mm to 400 mm. In addition, the outer diameter of the discharge tube 20 can be set in the range of 5 mm to 30 mm, preferably in the range of 8 mm to 25 mm.

[0032] In consideration of suppressing the degradation of the discharge tube due to the excimer light and suppressing the increase of the discharge start voltage, the wall thickness of the discharge tube 20 can be set within a range of, for example, 0.8 mm to 1.5 mm.

[0033] In order to prevent insufficient illumination due to narrowing of the discharge space and unstable discharge due to expansion of the discharge distance, the discharge distance, i.e., the distance between the dielectric 50 and the inner diameter of the discharge tube 20, can be set in the range of 2 mm to 12 mm, preferably in the range of 3 mm to 10 mm.

[0034] The foil electrode 30 is configured as an extremely thin strip electrode whose thickness is suppressed relative to the electrode width. Here, the thickness of the foil electrode 30 is set to be 1 / 30 or less, preferably 1 / 50 or less, and more preferably 1 / 100 or less relative to the electrode width. Figure 2 to Figure 4 In FIG. 1 , the thickness of the foil electrode 30 is exaggerated.

[0035] For example, the thickness of the foil electrode 30 may be set in the range of 20 μm to 50 μm in consideration of current capacity, ease of manufacturing, and prevention of peeling from the dielectric 50. On the other hand, the width of the foil electrode 30 may be set in the range of 1.2 mm to 10 mm in consideration of current capacity, ease of manufacturing, and prevention of interruption of discharge light due to enlarged electrode area.

[0036] The electrode material of the foil electrode 30 can be formed of a metal or alloy with high conductivity. Also, it can be made of a material that is easy to be polished by electric field. Here, molybdenum or an alloy containing molybdenum is used.

[0037] Here, the dielectric 50 is made of a dielectric material (such as SiO2). The thickness of the dielectric 50 can be set in the range of, for example, 0.1 mm to 2 mm in consideration of maintaining the limit of insulation and preventing an increase in the discharge start voltage.

[0038] The dielectric 50 is a flat material having a substantially constant thickness along the width direction (Y direction) of the foil electrode 30 (see Figure 4 , Figure 6 ), and is formed into a flat shape in the entire range of the discharge space S. It can also be said that the dielectric 50 is composed of a quadrangular columnar portion having a substantially constant thickness along the width direction (Y direction) of the foil electrode 30 and semi-cylindrical portions integrally formed at both ends of the quadrangular columnar portion.

[0039] The dielectric 50 is flattened along the thickness direction (X direction) of the foil electrode 30 to have an outer diameter W2 ( Figure 2 ) is smaller than the outer diameter W1 ( Figure 1 ) is a flat shape, so that the distance between the inner surface of the discharge tube and the outer surface of the dielectric along the thickness direction (X direction) of the foil electrode 30 is D21 ( Figure 2 ) is longer than the distance D11 from the outer surface of the dielectric along the width direction (Y direction) of the foil electrode 30 ( Figure 1 ).

[0040] like Figure 1 , Figure 2As shown in FIG. 1 , the dielectric 50 includes a portion (hereinafter referred to as a small diameter portion) 53 formed inside the discharge tube so as to extend toward the discharge space S side, and a portion (hereinafter referred to as a large diameter portion) 55 formed outside the discharge tube so as to protrude from the fusion portion 52 toward the power supply line 60 side, with the fusion portion 52 being sandwiched between the small diameter portion 53 and the large diameter portion 55. The position of a connection portion 54 connecting the small diameter portion 53 and the fusion portion 52 of the dielectric 50 along the tube axis C direction corresponds to the end portion 30T of the foil electrode 30.

[0041] A protruding portion (hereinafter referred to as an exhaust pipe) 22 is formed at the end of the discharge tube 20. The exhaust pipe 22 is formed during the lamp manufacturing process, and the front end side of the glass tube, which is the material of the outer tube, is heated and deformed to reduce its diameter, and a tube smaller than the glass tube is welded, thereby integrally forming the exhaust pipe 22.

[0042] The outer electrode 40 covers the outer surface 20S of the discharge tube 20 including the exhaust tube 22 except for the window 20W. Here, the area occupied by the window 20W on the outer surface of the discharge tube relative to the discharge interval is set to half of the circumferential area of ​​the discharge tube 20 (refer to Figure 4 ), wherein the discharge interval is an interval where the foil electrode 30 and the outer electrode 40 are opposite to each other along the lamp axis C.

[0043] The dielectric 50 that forms the double tube type lamp by being welded to the discharge tube 20 has a small diameter portion 53 and a large diameter portion 55. The outer diameter W1 (see FIG. 5 ) of the small diameter portion 53 along the width direction (Y direction) of the foil electrode 30 is Figure 1 ) and the outer diameter W2 along the thickness direction (X direction) (refer to Figure 2 ) are smaller than the outer diameter W12 of the circular cross-section large diameter portion 55. Here, the outer diameter W1 of the dielectric 50 along the width direction (Y direction) of the foil electrode 30 is set to be 3 / 4 or less, preferably 1 / 2 or less of the inner diameter D1 of the discharge tube 20.

[0044] Figure 5 It is an enlarged cross-sectional view of the foil electrode 30 .

[0045] As described above, the foil electrode 30 is an electrode formed to be very thin relative to the width w, and the thickness t of the foil electrode is suppressed to be less than 1 / 30 relative to the width w. The foil electrode 30 has a flat portion 32 with a constant thickness (= t), and has wedge-shaped portions 34A and 34B, and the front ends of the wedge-shaped portions 34A and 34B become thinner in a wedge shape from the width direction ends 32A and 32B of the flat portion 32 to the width direction ends E1 and E2 of the foil electrode 30.

[0046] For example, the angles θ1 and θ2 (angle θ of the edge E) at the two ends E1 and E2 in the width direction of the foil electrode 30 can be set within a range of 2° to 15°, preferably within a range of 10° or less, by considering the difficulty of peeling caused by the gap generated in the boundary portion with the covered dielectric, the size of the cross-sectional area of ​​the flat portion corresponding to the current capacity, and the suppression of the temperature rise caused by the generation of Joule heat. In addition, the inclination angle of the cross section of the flat portion 32 can be set within a range of less than 2°. The angle θ can be set according to the following angle: when the cross section near the range of about 100 μm away from the edge E of the foil electrode 30 is magnified and observed, the thickness increases from the edge E of the foil electrode toward the flat portion 32. As a result, in the foil electrode 30, the edge-shaped edge E is formed on the entire electrode along the tube axis C direction.

[0047] The flat portion 32 is formed so that the center (central portion) in the width direction coincides with the tube axis C, and the wedge-shaped portions 34A and 34B are symmetrical with respect to the flat portion 32. In addition, regarding the wedge-shaped portions 34A and 34B, the width direction length d1 of the wedge-shaped portions 34A and 34B is set to be less than 0.2 with respect to the electrode width w (d1 / w) of the foil electrode 30. Here, the inclination angle θ of the cross section from the width direction ends of the wedge-shaped portions 34A and 34B toward the width direction ends 32A and 32B of the flat portion 32 is formed to be constant.

[0048] The flat portion 32 is formed to have a thickness that accounts for 70% or more of the maximum thickness T of the foil electrode 30. For example, the length d between the widthwise ends 32A and 32B of the flat portion 32 is set to be 0.6 or more relative to the electrode width w of the foil electrode 30 (d / w).

[0049] Figure 6 It is an enlarged cross-sectional view of the foil electrode 30 and the dielectric 50 covering the foil electrode 30 .

[0050] The cross-sectional shape of the dielectric 50 is long oval or long circle. Figure 5 The arrangement and shape matching of the foil electrode 30 shown are cross-sectional shapes that reduce the difference in the distance from any surface of the foil electrode 30 to the outer surface 50S of the dielectric 50 (to the thickness of the foil electrode).

[0051] Here, the section M0 is defined as the central section (planar section) 50M0, and the section M0 has a planar (flat surface) outer surface 50S1 of a quadrangular columnar section that is substantially parallel to the flat section 32 of the foil electrode 30 and substantially perpendicular to the discharge surface 20D of the discharge tube 20. The section M1 is defined as the two end sections (curved section sections) 50M1, and the section M1 has a curved (semi-elliptical) outer surface 50S2 of a semi-cylindrical section that is convex from both ends of the central section 50M0 toward the outside in the electrode width direction (Y direction).

[0052] The quadrangular columnar portion is a columnar body whose cross section along the lamp diameter direction is a quadrilateral shape such as a square or a rectangle, and whose cross-sectional shape is the same along the tube axis C direction which is substantially parallel to the flat portion 32 of the foil electrode. The quadrangular columnar portion is a pair, and covers the vicinity of the center portion in the width direction of the foil electrode from both sides in the electrode thickness direction so that the thickness T2 is substantially constant.

[0053] The semi-cylindrical portion is a semi-cylindrical body whose cross section along the lamp diameter direction is approximately a semicircular shape such as a semi-ellipse, and whose cross-sectional shape is the same along the tube axis C. The semi-cylindrical portion is a pair, and covers the vicinity of the edge in the width direction of the foil electrode from both sides in the electrode width direction in a manner of surrounding the vicinity of the edge with the vicinity of the edge as the center, with a thickness T1 in the electrode width direction and a thickness T2 in the electrode thickness direction.

[0054] The boundary between the central portion (flat portion) 50M0 and the two end portions (curved portion) 50M1 of the dielectric 50 is located closer to the center (tube axis C) of the width direction of the foil electrode 30 than the two ends E1 and E2 of the foil electrode 30, preferably the two ends 32A and 32B of the flat portion 32 in the width direction. That is, the length of the section M0 along the width direction (Y direction) of the foil electrode is set to be smaller than w, preferably smaller than d. In addition, the length of the section M1 is formed to be larger than T1.

[0055] With respect to the structure of the foil electrode 30 and the dielectric 50 , a window 20W that enables efficient light emission is formed on the outer surface 20S of the discharge tube 20 .

[0056] As described above, the discharge tube 20 uses the outer surface portion of the discharge tube 20 that is not covered by the outer electrode 40 as the window 20W for light emission. Here, half of the circumferential region of the discharge tube 20 is formed as the window 20W. To explain in more detail, the outer electrode 40 has shielding portions 40M1 and 40M2 (see FIG. 4 ) that cover the outer surface 20S of the discharge tube 20 in the entire circumferential direction on the exhaust pipe 22 side and the power supply line 60 side. Figure 3 ), a window 20W having a semicircular cross-section is provided between the shielding portions 40M1 and 40M2.

[0057] One end E2 of foil electrode 30 faces outer electrode 40 , and the opposite end E1 faces window 20W. Window 20W is formed at a position relative to outer surface 20S of discharge tube 20 so that only one end E2 of foil electrode 30 faces outer electrode 40 .

[0058] Furthermore, the window 20W is formed in a region symmetrical with respect to the width direction (Y direction) of the foil electrode 30 as an axis of symmetry, and the window 20W is formed in a region symmetrical with respect to the dielectric 50. Therefore, one end E2 of the foil electrode 30 is directed toward the middle position of the semicircular cross-sectional portion 40M of the outer electrode 40, and the semicircular cross-sectional portion 40M is also formed in a region symmetrical with respect to the width direction (Y direction) of the foil electrode 30 as an axis of symmetry.

[0059] By arranging the window 20W in accordance with the formation position of the foil electrode 30 , in other words, by forming the window 20W in consideration of the width direction (Y direction) of the foil electrode 30 , the light radiation efficiency of the line irradiation type excimer lamp 10 is improved.

[0060] That is, the foil electrode 30 is formed with wedge-shaped portions 34A and 34B that are sharpened toward both ends E1 and E2 in the width direction, and one end E2 of the foil electrode 30 faces the outer electrode 40. Therefore, even if the area of ​​the window 20W (the volume of the discharge tube 20) as the discharge surface is increased, the discharge start voltage can be set low by electric field concentration, and the lighting startability can be maintained in a good state.

[0061] Furthermore, since the dielectric 50 is flattened along the width direction (Y direction) of the foil electrode 30, the cross-sectional area becomes smaller than that of a dielectric having a circular cross-section, thereby ensuring the volume of the discharge space S. That is, when viewed from the window 20W side as the discharge surface, the cross-sectional area of ​​the discharge space S is larger along the thickness direction (X direction) of the foil electrode 30.

[0062] Therefore, it is possible to suppress the attenuation of the light reflected by the outer electrode 40 while being guided to the window 20W by passing through the dielectric 50. This allows a small but large-diameter excimer lamp 10 to be configured, and the illuminance can be increased while adjusting the diameter of the discharge tube 20 and the size of the window 20W.

[0063] Furthermore, the formation area of ​​the window 20W is symmetrical (linear symmetry with the Y direction as the axis) with respect to the width direction (Y direction) of the foil electrode 30, and the flattened direction of the dielectric 50 is also along the width direction (Y direction) of the foil electrode 30. Thus, the illumination distribution of the light passing through the window 20W is made uniform.

[0064] As described above, the diameter of the small diameter portion 53 of the dielectric 50 disposed in the discharge tube 20 is smaller than the diameter of the large diameter portion 55 outside the discharge space S. Thus, the volume of the discharge space S can be ensured to be large, and the attenuation of the light emitted by the discharge generated in the discharge space S while traveling toward the window 20W is suppressed and guided.

[0065] The wedge-shaped portions 34A and 34B of the foil electrode 30 make the foil electrode 30 closely adhere to the dielectric 50, and a gap is not easily formed at the boundary portion with the dielectric 50, and peeling is not easily generated. In addition, by forming the flat portion 32 on the foil electrode 30, the close adhesion between the foil electrode 30 and the dielectric 50 can be improved to suppress peeling. As a result, the light intensity can be maintained while the lamp is lit.

[0066] Such a line irradiation type excimer lamp 10 can be manufactured by the following manufacturing method, for example.

[0067] First, the power supply line is connected to the foil electrode by resistance welding or the like, and a glass tube as a dielectric coating material is inserted. After the foil electrode is inserted, the glass tube is evacuated, and then the dielectric coating material is heated from the outside to be welded to the foil electrode. At this time, heating is adjusted so that the cross-sectional shape of the dielectric 50 described above is obtained.

[0068] For example, a dielectric having an oblong or oblong cross section can be formed by performing the following steps: rotating the glass tube while heating it with a burner or the like, thereby uniformly shrinking (reducing the diameter) the inner surface of the glass tube in the circumferential direction until it contacts the two ends (wedge-shaped portions) of the foil electrode, and shrinking the glass tube between the portions contacting the two ends (wedge-shaped portions) of the foil electrode in the thickness direction of the foil electrode to be integrated with the flat portion. Alternatively, a step of coating the dielectric or a step of cutting the glass tube may be performed.

[0069] A flange-shaped so-called abacus-shaped seal is formed at a position of the glass tube corresponding to the electrode edge along the tube axis direction. Then, a discharge tube of quartz glass or the like is formed with an exhaust pipe at one end and an insertion port at the other end, a dielectric with foil electrodes fused thereto is inserted into the discharge tube, and the insertion port of the discharge tube is fused to the abacus-shaped seal.

[0070] While heating the entire discharge tube, the discharge tube is evacuated through the exhaust pipe to remove impurities. Then, after the discharge gas is sealed, the exhaust pipe is sealed and an outer electrode is arranged on the outer surface of the discharge tube. At this time, the area on the outer surface of the discharge tube where the window is formed as the discharge surface is shielded, and the area where the outer electrode is arranged is irradiated with ultraviolet rays to perform surface treatment, and then the outer electrode is directly formed on the outer surface of the discharge tube by sputtering, thereby Figure 3As shown, the discharge tube is covered with a film-shaped outer electrode having a property of reflecting light including ultraviolet rays, such as an aluminum film, and a window 20W having a semicircular cross-section is provided as a portion through which light including ultraviolet rays passes.

[0071] In the excimer lamp 10 of the present embodiment described above, the dielectric 50 is configured to be flat, but it may be configured to be elliptical. That is, the dielectric 50 may be formed to have an elliptical cross section along the tube axis C. Furthermore, the dielectric 50 is not limited to being flat as a whole, but may be configured to be partially flat. For example, only a portion covering a portion of the foil electrode 30 may be flat.

[0072] The foil electrode 30 may be configured without the flat portion 32 and without the wedge-shaped portions 34A and 34B. The thickness of the end portion in the electrode width direction (Y direction) may be smaller than the thickness of the center portion.

[0073] The thickness T2 of the foil electrode 30 can be set according to the cross-sectional area, i.e., the inner diameter D1 of the discharge tube 20 in consideration of the uniformity of the illuminance distribution along the thickness direction (X direction) of the foil electrode 30. For example, the thickness T2 can be set to 1 / 200 or less of the inner diameter D1 of the discharge tube 20.

[0074] Furthermore, considering the lighting startability due to electric field concentration, the width W of the foil electrode 30 may be set according to the inner diameter D1 of the discharge tube 20. For example, the width W of the foil electrode 30 may be set to be less than 1 / 2, preferably less than 1 / 4 of the inner diameter D1 of the discharge surface 20D.

[0075] The structure of the outer electrode 40 may be an electrode structure other than an aluminum film, and may be configured so that light is reflected by providing a material or component capable of reflecting light independently of the outer electrode 40 instead of using only the outer electrode 40. Furthermore, light may be reflected by a material or component other than the outer electrode 40. Instead of emitting ultraviolet rays from the emission surface, visible light emitted from discharge or a phosphor may be emitted.

[0076] The size of the window 20W, that is, the ratio of the arc to the entire circumference (360°) of the outer surface of the discharge tube along the circumferential direction, can be set according to the use environment, etc., and a window with a cross-sectional arc shape having a center angle smaller than 180°, which is a center angle of a circular arc corresponding to half the circumference of the outer surface of the discharge tube, or a center angle exceeding 180° can be formed in a part of the circumferential direction of the outer surface of the discharge tube. In this case, the window 20W can be formed so that the two ends E1 and E2 of the foil electrode 30 face the outer electrode 40.

Claims

1. An excimer lamp, which is a line irradiation type excimer lamp, characterized in that: The excimer lamp has: Discharge tube; a dielectric covering an inner electrode extending in a strip shape in the discharge tube; and an outer electrode arranged along the circumference of the outer surface of the discharge tube, At least one end of the inner electrode along the width direction faces the outer electrode.

2. The excimer lamp according to claim 1, characterized in that: The other end of the inner electrode along the width direction faces the discharge surface of the discharge tube.

3. The excimer lamp according to claim 1, characterized in that: The discharge surface of the discharge tube is formed symmetrically with the width direction of the inner electrode as a symmetry axis.

4. The excimer lamp according to claim 1, characterized in that: The inner electrode is arranged coaxially with the dielectric, A distance between the outer surface of the dielectric and the inner electrode along a thickness direction of the inner electrode is shorter than a distance between the outer surface of the dielectric and the inner electrode along a width direction of the inner electrode.

5. The excimer lamp according to claim 1, characterized in that: The inner electrode is a foil electrode, The foil-shaped electrode has a flat portion having a substantially constant thickness along the width direction between both ends along the width direction of the foil-shaped electrode. The dielectric has a substantially constant thickness along a width direction of the foil-shaped electrode, and has an outer surface substantially parallel to the flat portion.

6. The excimer lamp according to claim 1, characterized in that: The dielectric has a small diameter portion formed inside the discharge tube and a large diameter portion formed outside the discharge tube. The small diameter portion of the dielectric has a diameter smaller than that of the large diameter portion along the width direction and the thickness direction of the inner electrode.

7. The excimer lamp according to any one of claims 1 to 6, characterized in that: The dielectric has a flat shape corresponding to a width direction of the inner electrode.

8. The excimer lamp according to any one of claims 1 to 6, characterized in that: The cross section of the dielectric is in the shape of an oblong circle or an oblong ellipse.

9. The excimer lamp according to any one of claims 1 to 6, characterized in that: The inner electrode is a foil electrode, The foil-shaped electrode has a flat portion having a substantially constant thickness along the width direction between both ends of the foil-shaped electrode along the width direction. The foil-shaped electrode is sharpened from both ends of the flat portion toward both ends of the foil-shaped electrode in a width direction.

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