Excimer lamp

Abstract

In a spot irradiation type excimer lamp, light such as ultraviolet rays is effectively irradiated toward an object to be irradiated. The excimer lamp (10) comprises a discharge tube (20), a thin electrode (30) extending along the tube axis (C) inside the discharge tube (20), an outer electrode (40) covering the outer surface of the discharge tube (20), and a dielectric (50) covering the thin electrode (30). The dielectric (50) is flat in the width direction (Y direction) of the thin electrode (30).

Description

Technology Field

[0001] The present invention relates to an excimer lamp, and in particular to an excimer lamp that irradiates light in the direction of the lamp axis (hereinafter referred to as a spot-irradiation type excimer lamp). Background Technology

[0003] In a spot-irradiation type excimer lamp, one end of the discharge tube is made into a light emission surface (output surface), and an outer electrode (such as an aluminum film) on a film that reflects ultraviolet rays is installed to cover the outer surface of the discharge tube (for example, see Patent Document 1).

[0004] Excimer light emitted from a discharge generated by applying a high-frequency voltage between an inner electrode and an outer electrode installed inside a discharge tube is guided toward the emission side of the discharge tube by reflection by the outer electrode, and is also guided toward the emission side by the fiber effect through which ultraviolet light passes through the walls of the discharge tube, thereby causing ultraviolet light to be emitted from the lamp emission side. Prior art literature

[0006] Japanese Registered Patent Publication No. 6557011 The problem to be solved

[0007] For example, when configuring a small spot-irradiation type excimer lamp (e.g., a discharge vessel with an outer diameter of several mm to several tens of mm), it may be necessary to place the object to be irradiated in close proximity and irradiate it intensively with light such as ultraviolet rays. Even in such cases, it may be required to irradiate light effectively. means of solving the problem

[0009] An excimer lamp, which is one embodiment of the present invention, comprises a discharge tube having a light emission surface formed at one end and a dielectric covering a foil electrode extending in a strip shape within the discharge tube. The foil electrode can be arranged to extend, for example, in the direction of the tube axis (lamp axis) of a tubular discharge vessel.

[0010] The configuration of the thin electrode is diverse, and the thin electrode can be configured such that the ends along the width direction of the thin electrode become thinner than the center of the thin electrode along the width direction. For example, the thin electrode may have a flat portion with a thickness approximately constant along the width direction between the ends along the width direction of the thin electrode, and may have a shape that is sharpened from the ends of the flat portion toward the ends along the width direction of the thin electrode.

[0011] The excimer lamp of the present invention has a dielectric that is flattened in the width direction of the thin electrode. Here, "flattened in the width direction of the thin electrode" means that it is a shape in which a flat surface portion is installed that is elongated along the width direction of the thin electrode and has a thickness that is approximately constant along the thickness direction of the thin electrode. This flattened shape can be described as a shape caused by flattening in the thickness direction of the thin electrode.

[0012] The arrangement configuration of the dielectric and the thin electrode is diverse, and the thin electrode can be configured so that it is arranged coaxially with respect to the dielectric, and the distance between the outer surface of the dielectric and the thin electrode along the thickness direction of the thin electrode can be configured to be shorter than the distance between the outer surface of the dielectric and the thin electrode along the width direction of the thin electrode.

[0013] The dielectric can be configured such that its flatness is determined based on the position of the thin electrode, that is, the width direction. For example, it can be configured to have an outer surface approximately parallel to the width direction of the thin electrode. Additionally, the dielectric can be configured to have an outer surface approximately perpendicular to the emission surface.

[0014] The dielectric can be applied in various shapes as it has a flattened specific shape. For example, the dielectric can be configured so that its cross-section is elongated (oval) or elongated elliptical. Additionally, the dielectric can be configured to have a small diameter portion formed within the discharge tube and a large diameter portion formed outside the discharge tube, such that the diameter of the thin electrode in the width and thickness directions of the small diameter portion becomes smaller than the diameter of the large diameter portion. Effects of the invention

[0016] According to the present invention, in a spot-irradiation type excimer lamp, light can be effectively irradiated toward an object to be irradiated. Brief explanation of the drawing

[0018] FIG. 1 is a schematic cross-sectional view along the electrode width direction of an excimer lamp according to the present embodiment. FIG. 2 is a schematic side view of the excimer lamp of the present embodiment seen from the exit surface side. FIG. 3 is a cross-sectional view along the electrode thickness direction of the excimer lamp of the present embodiment. Figure 4 is an enlarged cross-sectional view of the thin electrode. Figure 5 is an enlarged cross-sectional view of the thin electrode and the dielectric covering the thin electrode. Specific details for implementing the invention

[0019] Hereinafter, an excimer lamp of the present embodiment will be described with reference to the drawings.

[0020] FIG. 1 is a schematic cross-sectional view along the electrode width direction of the excimer lamp of the present embodiment. FIG. 2 is a schematic side view of the excimer lamp of the present embodiment seen from the exit surface side. FIG. 3 is a cross-sectional view along the electrode thickness direction of the excimer lamp of the present embodiment.

[0021] The excimer lamp (10) is a spot-irradiation type excimer lamp, and in this case, it is configured as a small spot-irradiation type excimer lamp. The excimer lamp (10) is equipped with a bottom-shaped discharge tube (discharge container) (20) made of a dielectric material such as quartz glass, and one end of the bottom part of the discharge tube (20) is configured as a light emission surface (output surface) (20D) containing ultraviolet light.

[0022] The discharge tube (20) is configured such that, in this case, the cross-section along the direction of the tube diameter (lamp diameter) is circular, and the inner diameter and thickness are constant along the tube axis (lamp axis) (C). A noble gas, such as xenon gas, or a mixture thereof, is sealed as a discharge gas in the discharge space (S) within the discharge tube (20). The discharge surface (20D) of the discharge tube (20) is made of a material that transmits light emitted from the discharge generated in the discharge space (S).

[0023] A foil electrode (30) extending in a strip shape along the tube axis (C) is disposed inside the discharge tube (20). The foil electrode (30) is covered (sealed) by a column-shaped dielectric (50) made of quartz glass or the like, and is embedded within the dielectric (50) so as not to be exposed to the discharge space (S). One end (30T) of the foil electrode (30) along the lamp axis (C) direction 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) installed externally.

[0024] The dielectric (50) is welded to the discharge tube (20) at a flange (hereinafter referred to as the welded part) (52) that protrudes in a flange shape in the diameter direction to form the inner tube of the excimer lamp (10), which is a double tubular lamp. The size of the outer diameter of the welded part (52) of the dielectric (50) is determined according to the inner diameter (D1) of the discharge tube (20).

[0025] As shown in FIG. 2, the thin electrode (30) is arranged coaxially with respect to the discharge tube (20), and the dielectric (50) is also arranged coaxially with respect to the discharge tube (20). Accordingly, the thin electrode (30) is arranged coaxially with the center position in the width direction and the center position in the thickness direction aligned with the center position of the dielectric (50). In addition, it is arranged in a position symmetrical with respect to the tube axis (C). In FIGS. 1 to 3, the width direction of the thin electrode (30) is defined as the Y direction, and the direction perpendicular thereto (thickness direction) is defined as the X direction.

[0026] An outer electrode (40) is installed on the outer surface (20S) of the discharge tube (20). The outer electrode (40) is made of a material that reflects light, such as ultraviolet rays, emitted from a discharge generated in the discharge space (S), and is composed of, for example, a film or plate having thermal conductivity and electrical conductivity. Here, the outer electrode (40) covers the outer surface (20S) of the discharge tube (20), excluding the discharge surface (20D). The outer electrode (40) can be composed of, for example, a film (such as an aluminum film) that reflects light including ultraviolet rays with a wavelength of 172 nm.

[0027] When a high-frequency voltage (e.g., a voltage in the range of several kV to several tens of kV at a frequency of several kHz to several tens of MHz) is applied between the thin electrode (30) and the outer electrode (40), a dielectric barrier discharge occurs between the outer surface of the dielectric (50) covering the thin electrode (30) and the inner surface of the discharge tube (20) covered by the outer electrode (40), and excimer light of a predetermined spectrum (e.g., wavelength 172 nm) is emitted from the discharge space (S).

[0028] Light emitted from the discharge space (S) is guided toward the emission surface (20D) by reflection by the outer electrode (40) and fiber effect by the dielectric (50) and the discharge tube (20), and is emitted from the emission surface (20D). By arranging the object to be irradiated so as to face the emission surface (20D), it is possible to perform light irradiation or ultraviolet irradiation treatment.

[0029] The size of the small spot-illumination type excimer lamp (10) can be determined in accordance with the usage environment, etc. For example, the axial length (luminous length) in which discharge occurs within the discharge tube (20) can be set in the range of 20 mm to 400 mm. Also, 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.

[0030] The thickness of the discharge tube (20) can be set to, for example, a range of 0.8 mm to 1.5 mm, in consideration of preventing deterioration of the discharge tube by excimer light and suppressing the rise in the discharge initiation voltage.

[0031] The discharge distance, that is, the distance between the dielectric (50) and the inner diameter of the discharge tube (20), can be set to a range of 2mm to 12mm, preferably 3mm to 10mm, taking into account the prevention of insufficient illumination due to the narrowing of the discharge space and the prevention of instability of the discharge due to the expansion of the discharge distance.

[0032] The thin electrode (30) is configured as an ultra-thin strip-shaped electrode with a thickness suppressed relative to the electrode width. Here, the thickness of the thin electrode (30) relative to the electrode width is set to 1 / 30 or less, preferably 1 / 50 or less, and more preferably 1 / 100 or less. In addition, in FIGS. 2 and 3, the thickness of the thin electrode (30) is shown in an exaggerated manner.

[0033] For example, the thickness of the thin electrode (30) can be set in the range of 20㎛ to 50㎛, taking into account the current capacity, ease of manufacturing, and prevention of delamination with the dielectric (50). Meanwhile, the width of the thin electrode (30) can be set in the range of 1.2㎜ to 10㎜, taking into account the current capacity, ease of manufacturing, and prevention of blockage of discharge light due to increased electrode area.

[0034] The electrode material of the thin electrode (30) can be formed from a metal or alloy with high conductivity. It can also be composed of a material that is easy to polish with an electric field. Here, molybdenum or an alloy containing it is used.

[0035] The dielectric (50) is composed of a dielectric material (SiO2, etc.) in this case. The thickness of the dielectric (50) can be set to, for example, a range of 0.1 mm to 2 mm, taking into account the limit for maintaining insulation and preventing an increase in the discharge initiation voltage.

[0036] As shown in FIG. 2, the dielectric (50) is formed to be flat along the tube axis (C). Also, the dielectric (50) has a thickness that is approximately constant along the width direction (Y direction) of the thin electrode (30). Therefore, it can be said that the dielectric (50) is composed of a rectangular columnar portion with a thickness that is approximately constant along the width direction (Y direction) of the thin electrode (30), and a semicircular columnar portion formed integrally at both ends of the rectangular columnar portion.

[0037] As the dielectric (50) is flattened in the thickness direction (X direction) of the thin electrode (30) and has an elongated flat shape in the width direction (Y direction) of the thin electrode (30), the outer diameter (W21) (Fig. 3) along the thickness direction (X direction) of the thin electrode (30) becomes smaller than the outer diameter (W11) (Fig. 1) along the width direction (Y direction) of the thin electrode (30). Therefore, the distance (D21) (Fig. 3) between the inner surface of the discharge tube (20M) along the thickness direction (X direction) of the thin electrode (30) and the outer surface of the dielectric is longer than the distance (D11) (Fig. 1) along the width direction (Y direction) of the thin electrode (30).

[0038] As illustrated in FIGS. 1 and 3, the dielectric (50) is provided with a portion (hereinafter referred to as the small diameter portion) (53) formed inside the discharge tube so as to extend toward the discharge space side (S) with the weld portion (52) in between, and a portion (hereinafter referred to as the large diameter portion) (55) formed outside the discharge tube so as to protrude toward the feed line (60) side from the weld portion (52). The position along the tube axis (C) of the connecting portion (54) connecting the small diameter portion (53) and the weld portion (52) of the dielectric (50) corresponds to the end (30T) of the thin electrode (30).

[0039] Figure 4 is an enlarged cross-sectional view of the thin electrode (30).

[0040] As described above, the thin electrode (30) is an electrode formed with a very thin thickness relative to the width (w) of the thin electrode, and the thickness (t) relative to the width (w) of the thin electrode is suppressed to 1 / 30 or less. The thin electrode (30) has a flat portion (32) with a constant thickness (=t), and has a wedge-shaped portion (34A, 34B) that tapers to a wedge shape from both ends in the width direction (both ends in the width direction) (32A, 32B) of the flat portion (32) to both ends in the width direction (both ends in the width direction) (E1, E2) of the thin electrode (30).

[0041] For example, the angles (θ1, θ2) (angle (θ) of the edge (E)) of the two ends (E1, E2) in the width direction of the thin electrode (30) can be set to a range of 2° or more and 15° or less, preferably 10° or less, by considering factors such as difficulty in preventing delamination due to a gap formed at the boundary with the coated dielectric, the size of the cross-sectional area of ​​the flat portion corresponding to the current capacity, and the suppression of temperature rise due to the generation of Joule heat. In addition, the inclination angle of the cross-section of the flat portion (32) can be set to a range of less than 2°. This angle (θ) can be determined by observing a cross-section in the vicinity of a range of about 100 μm from the edge (E) of the thin electrode (30) in enlargement, and from the angle at which the thickness increases from the edge (E) of the thin electrode toward the flat portion (32). Accordingly, in the thin electrode (30), an edge-shaped edge (E) is formed along the entire electrode along the direction of the tube axis (C).

[0042] The flat portion (32) is formed such that its width direction center (central portion) coincides with the tube axis (C), and the wedge-shaped portions (34A, 34B) have a shape symmetric to the flat portion (32). In addition, the width direction length (d1) (d1 / w) of the wedge-shaped portions (34A, 34B) relative to the electrode width (w) of the thin electrode (30) is set to be 0.2 or less. Here, the angle of inclination (θ) of the cross-section from both ends in the width direction toward both ends (32A, 32B) in the width direction of the flat portion (32) is formed to be constant.

[0043] Additionally, the flat portion (32) is formed to have a thickness that accounts for at least 70% of the maximum thickness (T) of the thin electrode (30). For example, the length (d) (d / w) between the two ends (32A, 32B) in the width direction of the flat portion (32) relative to the electrode width (w) of the thin electrode (30) is set to be 0.6 or more.

[0044] FIG. 5 is an enlarged cross-sectional view of a thin electrode (30) and a dielectric (50) covering the thin electrode (30).

[0045] As described above, the dielectric (50) has a flat shape along the tube axis (C) direction, and the cross-section of the dielectric (50) is elongated oval or elongated (oval shape). The dielectric (50) has a roughly uniform cross-sectional shape over the area covering the thin electrode (30) along the tube axis (lamp axis) (C).

[0046] The elongated elliptical or elongated cross-sectional shape of the dielectric (50) is a cross-sectional shape that reduces the difference in distance (thickness to the thin electrode) from any surface of the thin electrode (30) to the outer surface (50S) of the dielectric (50) in accordance with the arrangement and shape of the thin electrode (30) shown in FIG. 4.

[0047] Here, the section (M0) in which the outer surface (50S1) of a rectangular column-shaped portion is formed, which is approximately parallel to the flat portion (32) of the thin electrode (30) and approximately perpendicular to the discharge surface (20D) of the discharge tube (20), is called the central portion (flat portion) (50M0). Additionally, the section (M1) in which the outer surface (50S2) of a convex semi-circular portion is formed, extending outward from both ends of the central portion (50M0) in the electrode width direction (Y direction), is called the end portion (curved portion) (50M1).

[0048] The square columnar part has a cross-section along the lamp diameter direction that approximates a square, such as a square or a rectangle, and is a columnar body with a uniform cross-sectional shape along the tube axis (C) direction that is approximately parallel to the flat part (32) of the thin electrode. A pair of these square columnar parts cover the area near the center in the width direction of the thin electrode from both sides in the electrode thickness direction so that the thickness (T2) is approximately constant.

[0049] Additionally, the semicircular upper portion has a cross-section along the lamp diameter direction that approximates a semicircle, such as a semi-elliptical shape, and is a semicircular body with a uniform cross-sectional shape along the tube axis (C). A pair of these semicircular upper portions are used to cover the edge of the thin electrode in the width direction from both sides in the electrode width direction, with the electrode width direction thickness (T1) and the electrode thickness direction thickness (T2) surrounding the edge.

[0050] The boundary between the central part (flat part) (50M0) and the ends (curved part) (50M1) of the dielectric (50) is located along the width direction (Y direction) of the thin electrode (30), and is positioned closer to the center (tube axis (C)) of the thin electrode (30) than to the ends (E1, E2) of the thin electrode (30), preferably the ends (32A, 32B) of the flat part (32). That is, the length of the section (M0) along the width direction (Y direction) of the thin electrode is determined to be smaller than w, and preferably smaller than d. Also, the length of the section (M1) is formed to be larger than T1.

[0051] As described above, the dielectric (50) that forms a double-tube lamp by welding with the discharge tube (20) has a small diameter portion (53) and a large diameter portion (55). The outer diameter (W11) in the width direction (Y direction) and the outer diameter (W21) in the thickness direction (X direction) of the thin electrode (30) of the small diameter portion (53) are both smaller than the outer diameter (W12) of the large diameter portion (55), which has a circular cross-sectional shape.

[0052] Here, the outer diameter (W11) along the width direction (Y direction) of the thin electrode (30) of the dielectric (50) is set to be 3 / 4 or less, preferably 1 / 2 or less, with respect to the inner diameter (D1) of the discharge tube (20).

[0053] According to the excimer lamp (10) of the present embodiment described above, the light radiation efficiency is increased as a spot irradiation type excimer lamp (10) by the configuration in which the dielectric (50) is flat.

[0054] That is, because the dielectric (50) is flat, the cross-sectional area is reduced compared to a dielectric with a circular cross-sectional shape, and the volume of the discharge space (S) is secured. That is, the cross-sectional area of ​​the discharge space (S) is large along the thickness direction (X direction) of the thin electrode (30) when viewed from the discharge surface (20D) side.

[0055] Therefore, attenuation of light reflected from the outer electrode (40) can be suppressed while it is guided to the emission surface (20D) along the tube axis (C) direction. This makes it possible to construct an axially long excimer lamp (10) even if small, allowing for high brightness while significantly adjusting the length along the tube axis (C) direction of the discharge tube (20).

[0056] In addition, since the dielectric (50) is flat, uniformity of the roughness distribution along the thickness direction (X direction) of the thin electrode (30) can be achieved. That is, for an electrode structure in which a flat portion (32) is installed on the thin electrode (30), the distance interval to the outer surface (50S) of the dielectric (50), that is, the thickness along the thickness direction (X direction) of the thin electrode (30), is approximately constant along the width direction (Y direction) of the thin electrode (30).

[0057] Therefore, the occurrence of a biased discharge in the width direction (Y direction) of the thin electrode (30) is suppressed, and in particular, the decrease in roughness near the center is suppressed. By doing so, the area of ​​the discharge surface (20D) (volume of the discharge tube (20)) can be increased while promoting uniformity of the roughness distribution.

[0058] Additionally, the small diameter portion (53) disposed within the discharge tube (20) of the dielectric (50), that is, within the discharge space (S), has a diameter (W11) smaller than the large diameter portion (55) outside the discharge space (S). As a result, it is possible to secure a larger volume of the discharge space (S), thereby suppressing attenuation of light emitted from the discharge generated in the discharge space (S) while it travels toward the emission surface (20D) due to the fiber effect caused by the dielectric (50) and the discharge tube (20) or reflection by the outer electrode (40).

[0059] Meanwhile, the thin electrode (30) forms wedge-shaped portions (34A, 34B) that are sharpened toward both ends (E1, E2) in the width direction, and the dielectric (50) is flat along the width direction (Y direction) of the thin electrode (30). Therefore, even if the area of ​​the discharge surface (20D) (volume of the discharge tube (20)) is increased, the discharge initiation voltage can be set low by the electric field concentration, and the lighting startability can be maintained in a good state.

[0060] In addition, due to the wedge-shaped portions (34A, 34B) of the thin electrode (30), the thin electrode (30) adheres closely to the dielectric (50), making it difficult for a gap to form at the boundary portion with the dielectric (50), thereby making it difficult for delamination to occur. Furthermore, by forming a flat portion (32) on the thin electrode (30), the adhesion between the thin electrode (30) and the dielectric (50) can be increased, thereby suppressing delamination. As a result, the attenuation of light is suppressed while it travels through the interior of the dielectric (50) toward the emission surface (20D) due to the fiber effect, and the illuminance of the light can be enhanced.

[0061] An excimer lamp (10) equipped with such a dielectric (50) can be manufactured, for example, by the following manufacturing method.

[0062] First, a feed line is connected to the thin electrode by resistance welding or the like, and inserted into a glass tube that serves as a dielectric film material. After inserting the thin electrode, the inside of the glass tube is vacuumed, and then the dielectric film material is heated from the outside to bond with the thin electrode. At this time, heating adjustment is performed to achieve the cross-sectional shape of the dielectric (50) described above.

[0063] For example, by rotating the glass tube and heating it with a burner or the like, the inner surface of the glass tube is uniformly contracted (shrinked) in the circumferential direction until it comes into contact with both ends (wedge-shaped portions) of the thin electrode, and the glass tube between the parts in contact with both ends (wedge-shaped portions) of the thin electrode is contracted along the thickness direction of the thin electrode to integrate with the flat portion, it is possible to form a dielectric with an elongated oval cross section or an elongated spherical cross section. In addition, this process may be performed instead of the process of coating the dielectric or the process of cutting the glass tube.

[0064] A flange-shaped, so-called abacus-bead-shaped seal is formed at a position on the glass tube corresponding to the electrode edge along the tube axis. Then, a discharge tube made 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 material with a thin electrode attached is inserted into the discharge tube, and the insertion port of the discharge tube is welded to the abacus-bead-shaped seal.

[0065] While heating the entire discharge tube, vacuum suction is performed through the exhaust pipe to remove impurities. Then, after sealing the discharge gas, the exhaust pipe is sealed, and an outer electrode is placed on the outer surface of the discharge tube. At this time, the outer electrode is formed directly on the outer surface of the discharge tube by sputtering after masking the area on the outer surface of the discharge tube that becomes the discharge surface, surface treating the area where the outer electrode is installed by ultraviolet irradiation, and then sputtering.

[0066] In the excimer lamp (10) of the present embodiment described above, the dielectric (50) is configured to be flat, but it is also possible to configure it to be elliptical. That is, the dielectric (50) having an elliptical cross-section may be formed along the tube axis (C). In addition, the dielectric (50) is not limited to being flat throughout, but may be configured to be partially flat. For example, only the part covering a portion of the inner electrode (30) may be flat.

[0067] Regarding the thin electrode (30), it is possible to have a configuration in which the flat portion (32) is not installed, or a configuration in which the wedge-shaped portion (4A, 34B) is not installed. It is preferable to configure it so that the thickness of the end portion is smaller than that of the center portion in the electrode width direction (Y direction).

[0068] The thickness (T2) of the thin electrode (30) can be determined according to the area of ​​the discharge surface (20D) of the discharge tube (20), i.e., the inner diameter (D1), by considering the uniformity of the roughness distribution along the thickness direction (X direction) of the thin electrode (30). For example, it can be determined to be 1 / 200 or less of the inner diameter (D1) of the discharge surface (20D).

[0069] In addition, regarding the width (W) of the thin electrode (30), it is possible to determine it according to the area of ​​the discharge surface (20D) of the discharge tube (20), that is, the inner diameter (D1), taking into consideration the lighting start capability due to electric field concentration. For example, the width (W) of the thin electrode (30) can be determined to be 1 / 2 or less, preferably 1 / 4 or less, of the inner diameter (D1) of the discharge surface (20D).

[0070] The configuration of the outer electrode (40) may include an electrode configuration other than an aluminum film, and it may be configured to reflect light by installing a material or component capable of reflecting light, rather than reflecting light solely by the outer electrode (40). It may also be configured to reflect light by a material or component other than the outer electrode (40). It may be configured to emit visible light emitted from a discharge or phosphor, rather than emitting ultraviolet light from the emission surface. Explanation of the symbols

[0072] 10 Excimer Lamp 20 discharge tubes 20D ejection surface 30 inner electrode (thin electrode) 40 outer electrode 50 Genomes

Claims

Claim 1 An excimer lamp comprising a discharge tube having a light emission surface formed at one end and a dielectric covering a thin electrode extending in a strip shape within the discharge tube, wherein the dielectric has a small diameter portion formed within the discharge tube and a large diameter portion formed outside the discharge tube, wherein the small diameter portion of the dielectric is flattened in alignment with the width direction of the thin electrode, wherein the thin electrode has a flat portion having a constant thickness along the width direction between both ends along the width direction of the thin electrode, wherein the small diameter portion of the dielectric has an outer surface parallel to the width direction of the thin electrode, and wherein the distance interval from the flat portion to the outer surface is constant along the width direction of the thin electrode. Claim 2 An excimer lamp according to claim 1, characterized in that the narrow portion of the dielectric is an outer surface with a planar shape perpendicular to the emission surface. Claim 3 An excimer lamp according to claim 1, characterized in that the diameter of the thin electrode of the small diameter portion along the width and thickness directions is smaller than the diameter of the large diameter portion. Claim 4 An excimer lamp according to claim 1, characterized in that the thin electrode is sharpened from both ends of the flat portion toward both ends along the width direction of the thin electrode. Claim 5 An excimer lamp according to any one of claims 1 to 4, wherein the thin electrode is arranged coaxially with respect to the dielectric, and the distance between the outer surface of the dielectric and the thin electrode along the thickness direction of the thin electrode is shorter than the distance between the outer surface of the dielectric and the thin electrode along the width direction of the thin electrode. Claim 6 delete Claim 7 delete

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