JP7082498B2 - Discharge lamp - Google Patents

Description

The present invention relates to discharge lamps such as excimer lamps and external electrode type fluorescent lamps that are discharged by a dielectric barrier discharge or a capacitance-coupled high-frequency discharge, and more particularly to a discharge lamp having a double-tube structure.

In an excimer lamp or the like having a double tube structure in which an inner tube and an outer tube form a light emitting tube, the outer tube and the inner tube are welded at a sealing portion and are integrally sealed. Since the inner tube is supported by the outer tube at its end, if the inner tube bends due to its own weight and impact or vibration is transmitted to the lamp during transportation, the inner surface of the outer tube may be damaged and the sealing part may be damaged. be. In particular, in the case of a lamp having a small diameter and a long length, the load applied to the sealing portion is large.

In order to prevent this, a lamp structure in which a flat plate is sandwiched between the inner tube and the outer tube is known (see Patent Document 1). There, a plurality of ring-shaped flat plates are arranged along the lamp axis direction and welded to the inner tube. By contacting the ring-shaped plate with the outer tube, the inner tube is supported over the entire length direction.

Japanese Unexamined Patent Publication No. 2009-230868

In excimer lamps and the like, a fluorescent substance or the like may be applied to the inner surface of the outer tube and the outer surface of the inner tube to form a film. However, when the ring-shaped flat plate is provided, it is welded or in contact with the inner surface of the outer tube over the entire outer peripheral surface thereof, which hinders the application of the phosphor and makes it difficult to form a homogeneous film.

Therefore, it is required to realize a lamp structure capable of forming a homogeneous film in the arc tube while reliably supporting the inner tube.

The discharge lamp of the present invention is a discharge lamp having a double tube structure including an outer tube and an inner tube, and includes a pair of rod-shaped support members arranged between the outer tube and the inner tube. The support member extends radially from the outer surface of the inner tube and supports the inner tube by welding or contact with the outer tube.

The number of pairs of support members is arbitrary. For example, it can be composed of a pair or a plurality of pairs of support members. The pair of support members may be arranged facing each other or may be offset along the ramp axis. For example, one support member can be placed along the same side (ie, not facing each other) at two different locations along the ramp axis, and at more locations on the same side or opposite side. It is possible to arrange the support members and form the support members with a pair or more. On the other hand, as the shape of the support member, various shapes such as a straight line, a polygonal line, and a curved line can be applied. The support member can be made of the same material as the outer tube or the inner tube. It is also possible to form a film on at least one of the inner surface of the outer tube and the outer surface of the inner tube.

The pair of support members can be configured to be rotationally symmetric with respect to the ramp axis, taking into account force balance. For example, support members having the same shape may be arranged on the same line. Further, the pair of support members can be arranged to face each other at a predetermined position (same position) along the lamp axis direction.

The welded portion between the support member and the outer surface of the inner tube can be formed into a curved surface. When the inner tube has an elliptical cross section, the pair of support members can be configured to extend along the long axis direction of the inner tube in consideration of welding and stable support. It is also possible to make the width of the support member shorter than the length of the long axis of the inner pipe.

On the outer tube, a first introduction tube extending along the ramp axis direction may be formed at one end, and a second introduction tube extending in a direction different from the ramp axis direction may be formed at the other end. It is possible. The pair of support members can be provided closer to the first introduction pipe than to the second introduction pipe.

As a discharge lamp, the outer tube and the inner tube are integrally welded at one end of the lamp, and at the other end, a gap is created between the tip surface of the inner tube and the inner surface of the outer tube. It is possible to form. In this case, the pair of support members can be configured to be located away from the tip surface of the inner tube by a distance longer than the distance interval along the ramp axis direction of the gap.

The method for manufacturing a discharge lamp according to one aspect of the present invention is a step of forming a first introduction tube and a second introduction tube with respect to the outer tube, and a step of welding a rod-shaped support member to the outer surface of the inner tube. And the step of welding the outer tube and the inner tube to form an arc tube having an integrated double tube structure, and welding the outer tube and the support member before or after welding the outer tube and the inner tube. It includes a step and a step of forming a film on the surface inside the arc tube by flowing in and out of the paint from the first introduction tube.

According to the present invention, it is possible to prevent cracks in the sealing portion of the arc tube and to form a uniform film in the arc tube.

It is a schematic plan view of the discharge lamp of this embodiment. It is a figure which showed the discharge lamp in the sealed state. It is a partially enlarged view of the discharge lamp of FIG. It is sectional drawing of the discharge lamp along the line IV-IV of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic plan view of an excimer lamp according to the present embodiment. FIG. 2 is a diagram showing a sealed discharge lamp.

The discharge lamp 10 is a lamp having a double tube structure, and includes a light emitting tube 15 in which a bottomed outer tube 20 and an inner tube 30 are integrally welded in a sealing portion 12. Here, it is configured as a small diameter and long excimer lamp, the axial length of the arc tube 15 is 300 to 1050 mm, the discharge distance is 1 to 17 mm, the inner diameter of the outer tube 20 is 6 to 40 mm, and the wall thickness of the outer tube 20. Is set in the range of 0.7 to 2 mm.

A discharge space S in which a rare gas such as xenon gas or a mixed gas is sealed is formed between the outer tube 20 and the inner tube 30. A phosphor film C is formed on the inner surface of the arc tube 15.

The inner tube 30 has an elliptical cross section, and a band-shaped inner electrode 50 is arranged inside the inner tube 30 along the X direction of the lamp axis. A spiral outer electrode 40 is wound around the outer surface of the outer tube 20 along the X direction of the lamp axis. The feeder line 80 connected to the end of the inner electrode 50 is connected to a power supply unit (not shown) installed outside, and power is supplied to the discharge lamp 10 via the feeder line 80.

The polarities of the outer electrode 40 and the inner electrode 50 are defined here as the cathode and the anode, and the outer electrode 40 and the inner electrode 50 are arranged to face each other with the arc tube 15 which is a dielectric interposed therebetween. When power is supplied to the discharge lamp 10, a dielectric barrier discharge occurs in the discharge space S between the outer electrode 40 and the inner electrode 50, and excimer light having a predetermined spectrum is emitted. The phosphor film C is excited by excimer light and emits fluorescence.

At one end of the outer tube 20, a first introduction tube 60 is formed on the lamp shaft X. Further, in the vicinity of the sealing portion 12 of the outer tube 20, the second introduction tube 70 is formed at a position away from the lamp shaft X in a direction inclined by a predetermined angle with respect to the lamp shaft X. Here, the second introduction pipe 70 is defined to be tilted in the range of 40 ° to 80 ° with respect to the lamp axis X in the direction opposite to that of the first introduction pipe 60.

Support members 90 and 95 are arranged between the outer pipe 20 and the inner pipe 30, that is, in the discharge space S. The support member 90 is arranged near the first introduction pipe 60, and the support member 95 is arranged near the center along the lamp axis X. The support members 90 and 95 are welded to the outer surface of the inner tube 30 and the inner surface of the outer tube 20 to support the inner tube 30.

FIG. 3 is a partially enlarged view of the discharge lamp of FIG. FIG. 4 is a cross-sectional view of the discharge lamp along lines IV-IV of FIG.

As shown in FIG. 4, the support member 90 here is composed of a pair of rod-shaped members 90A and 90B. The support member may be composed of not only a pair of rod-shaped members but also one or three or more rod-shaped members. The rod-shaped members 90A and 90B are linear columnar members here, and have a cross-sectional shape (circular cross-sectional shape) of the same size as a whole. Further, the rod-shaped members 90A and 90B have the same cross-sectional shape as each other. The welded portion between the rod-shaped members 90A and 90B and the outer surface of the inner tube 30 is formed in a curved surface shape in the cross section in the X direction of the lamp axis. (See Fig. 3).

The rod-shaped members 90A and 90B are made of the same material as the outer tube 20 and the inner tube 30. The support member 90 here is formed of quartz glass having the same light transmittance as the outer tube 20 and the inner tube 30.

As shown in FIGS. 1 and 2, the rod-shaped members 90A and 90B are arranged at predetermined positions along the direction of the lamp shaft X, and as shown in FIG. They are arranged facing each other along the same line. Further, the rod-shaped members 90A and 90B are welded to the outer surface of the inner tube 30 so as to be along the major axis direction LY of the inner tube 30 having an elliptical cross section. The width W of the rod-shaped members 90A and 90B is shorter than the major axis length L of the inner tube 30 having an elliptical cross section.

As shown in FIG. 3, the tip surface 30T of the inner tube 30 is separated from the outer tube 20 (inner surface) along the lamp axis X by a predetermined distance T1. The distance interval T1 is larger than the diameter of the first introduction pipe 60. In this gap portion S1, a sufficient space is provided so that the phosphor does not remain in the arc tube 15 and flows out when the phosphor is applied. On the other hand, the support member 90 is provided at a position separated from the tip surface 30T of the inner tube 30 by a predetermined distance interval T2. The distance interval T2 is longer than the distance interval T1.

Such a discharge lamp 10 is manufactured by the following process.

First, a first introduction pipe (see FIG. 2) along the pipe axis is formed at one end of the outer pipe, and the direction opposite to that of the first introduction pipe is formed near the other end. A second introduction pipe (see FIG. 2) having an angle of 40 ° to 80 ° with respect to the pipe axis is formed. On the other hand, a pair of support members are welded to the inner tube in which a foil-shaped inner electrode is embedded so that the root is curved at a predetermined interval.

Then, the inner tube and the outer tube are welded together to form an integrated arc tube. When welding the inner tube and the outer tube, the support member and the outer tube are welded together. At this time, the support member and the outer tube may be welded after the inner tube and the outer tube are welded, and the support member and the outer tube are welded before the inner tube and the outer tube are welded. May be good. After that, the arc tube is arranged so that the first introduction tube faces downward in the vertical direction, and the inside of the arc tube is put into a negative pressure state by sucking from the second introduction tube, and the paint (here, fluorescence) is applied from the first introduction tube. Inflow of body paint). After that, the paint is discharged by adjusting the pressure to form a phosphor film in the arc tube.

One of the first introduction tube and the second introduction tube is hermetically sealed by heating and melting, and the arc tube is evacuated from the other introduction tube to remove impurities. The discharge gas is sealed in the arc tube through the introduction tube that is not airtightly sealed, and the introduction tube is airtightly sealed by heating and melting. Then, the outer electrode is arranged on the outer surface of the arc tube. The support member may not be welded to the outer tube so that a slight gap may be formed. In this case, the inner tube is supported by the support member by arranging the discharge lamp along the horizontal direction so that the support member is along the vertical direction.

As described above, according to the present embodiment, in the discharge lamp 10 having a double tube structure in which the outer tube 20 and the inner tube 30 are integrally welded, the outer tube 20 extends radially from the outer surface of the inner tube 30. Support members 90 and 95 that support the inner tube 30 by welding or contact with the inner tube 30 are provided.

By providing the rod-shaped support members 90 and 95, it is possible to suppress the bending of the inner pipe, prevent the inner surface of the outer pipe from being damaged, and prevent the sealing portion from being damaged. In particular, by welding the support members 90 and 95 to the outer pipe 20 and the inner pipe 30, the inner pipe 30 can be firmly supported.

Further, since the support members 90 and 95 are rod-shaped, they are not welded over the entire circumferential direction at predetermined points on the inner surface of the outer tube and the outer surface of the inner tube, but are welded only to a small part. As a result, the fluorescent paint can flow in and out along the entire lamp axis X of the discharge lamp 10, and a homogeneous fluorescent film can be formed. In particular, by forming the rod-shaped members 90A and 90B in a columnar shape, the flow of the fluorescent paint does not become an obstacle. Further, by forming the welded portion between the rod-shaped members 90A and 90B and the outer surface of the inner tube 30 into a curved surface shape such as a skirt shape, it is possible to prevent the fluorescent paint from accumulating in the welded portion and becoming a so-called lump. ..

When a homogeneous phosphor film is formed, it becomes possible to reduce the effects of thermal expansion and contraction between the phosphor and the arc tube, and impurities contained in the phosphor, and it becomes possible to reduce the influence of impurities contained in the phosphor. When airtightly sealed, cracks in the introduction tube can be prevented.

In addition, the formation of a homogeneous phosphor film makes it possible to radiate fluorescence uniformly from the entire discharge lamp. Further, the support members 90 and 95 do not act as a barrier to the flow of the discharge gas, and the convection of the discharge gas can realize a uniform discharge without bias.

In the present embodiment, the rod-shaped members 90A and 90B are arranged along the same line when viewed from the lamp axis X direction. Thereby, the inner tube 30 can be supported at a position coaxial with the outer tube 20 through the lamp manufacturing process. Further, by being supported at a coaxial position, when the phosphor is applied, the fluorescent paint flows in and out without being biased in one direction, enabling the formation of a homogeneous fluorescent film. Further, since the rod-shaped members 90A and 90B are arranged so as to face each other, it is not necessary to particularly consider the positioning of the discharge lamp in the axial direction.

Further, the rod-shaped members 90A and 90B are welded to the inner tube 30 having an elliptical cross section along the long axis direction LY so that the welding area becomes smaller. Since the width W of the rod-shaped members 90A and 90B is relatively small, the influence of the support member 90 blocking light can be suppressed. Further, since the inner tube 30 is welded in a thick direction (LY), it is possible to prevent the inner tube from being deformed or bent due to heat during welding.

Since the support members 90 and 95 are made of quartz glass having the same light transmittance as the outer tube 20 and the inner tube 30, it is possible to suppress a decrease in the amount of light. Further, in the case of providing a discharge lamp that does not require ozone generation, for example, an arc tube can be formed of quartz glass doped with metal, and a support member can be formed according to the arc tube.

By providing the gap portion S1 between the inner tube 30 and the outer tube 20, when the phosphor is applied, the fluorescent paint is not accumulated between the inner tube and the outer tube, and a uniform phosphor film is formed. Enables. In particular, when the fluorescent paint is discharged, it is possible to prevent the fluorescent paint from accumulating near the tip surface 30T of the inner tube 30 and becoming lumpy.

On the other hand, the support member 90 is arranged at a position farther than the gap S1. Considering that the inner pipe 30 is a cantilever-shaped support by the sealing portion 12, it is preferable to arrange the support member 90 as close to the tip surface 30T of the inner pipe 30 as possible. However, in consideration of the smooth inflow and outflow of the fluorescent paint, the support member 90 is arranged at a position farther than the gap S1 (T1 <T2).

By providing the support member 90 at a position closer to the first introduction tube 60 than to the second introduction tube 70, the phosphor can be reliably formed on the support member 90 as well. Further, since the second introduction pipe 70 is tilted with respect to the lamp axis X, the second introduction pipe is sucked from the second introduction pipe as compared with the second introduction pipe perpendicular to the lamp axis. The amount of the phosphor applied to the introduction tube is suppressed, and cracks in the introduction tube when the second introduction tube is hermetically sealed can be prevented.

The rod-shaped members 90A and 90B are not limited to the columnar shape, and the cross-sectional shape size may not be constant in the longitudinal direction. For example, it may be tapered. In this case, a uniform fluorescent film is applied to the inner surface of the outer tube to increase the radiation efficiency of fluorescence. In order to facilitate the lamp manufacturing process, the outer tube is tapered toward the outer tube. Is good. Furthermore, it is also possible to make it into a polygonal line or a curved line. The rod-shaped members 90A and 90B do not have to have the same shape. Then, more support members than the support members 90 and 95 may be provided, or only one support member may be provided.

The rod-shaped members 90A and 90B may be arranged along the minor axis direction of the inner pipe 30. On the other hand, the inner tube 30 is not limited to an elliptical cross section, and can be configured into another tubular shape such as a circular cross section. The support member 90 does not have to be formed by the pair of rod-shaped members 90A and 90B, and the inner tube 30 may be coaxially supported with respect to the outer tube 20. For example, if at least two rod-shaped members are arranged so as to be in the same radial direction when viewed from the lamp axis direction, three or more rod-shaped members may be prepared. Further, the rod-shaped members 90A and 90B are not limited to being arranged at the same position (opposite arrangement) with respect to the lamp axis X, and one of the rod-shaped members 90A and 90B is arranged at a position offset back and forth along the lamp axis X so as to be rotationally symmetric. You may. Alternatively, a plurality of support members composed of one rod-shaped member may be arranged along the lamp axis at predetermined intervals.

The welded portion between the rod-shaped members 90A and 90B and the outer surface of the inner tube 30 does not have to have a curved surface shape extending like a skirt, and has a convex shape that rises toward the outer tube in the cross section in the X direction of the lamp axis, for example. A curved shape such as a dome shape is also possible. A curved surface that makes it difficult for the fluorescent paint to collect is desirable, but the rod-shaped members 90A and 90B may be welded at a right angle so that the angle formed by the outer surface of the inner tube 30 is 90 °. This can be formed by heat adjustment when welding the rod-shaped members 90A and 90B.

In the present embodiment, the discharge lamp 10 is composed of a long excimer lamp, but other discharge lamps may be used. As described above, the support members 90 and 95 may not be welded to the outer tube 20 and may be contact-supported. In this case, the phosphor can be applied to the entire surface of the arc tube 15. Alternatively, the heating at the time of welding may be adjusted to form a small wedge-shaped gap along the circumferential direction at the end of the welded portion between the rod-shaped members 90A and 95B and the inner surface of the outer tube 20. By applying a fluorescent substance to this gap as well, the influence of the rod-shaped members 90A and 90B can be reduced as much as possible. It is also possible to form another film such as an ultraviolet reflecting film instead of the phosphor film.

10 Discharge lamp 20 Outer tube 30 Inner tube 90 Support member 90A Rod-shaped member (support member)
90B rod-shaped member (support member)

Claims (12)

A double tube structure discharge lamp with an outer tube and an inner tube.
A rod-shaped support member arranged between the outer tube and the inner tube and composed of a pair or a plurality of pairs is provided.
A discharge lamp in which the support member extends radially from the outer surface of the inner tube and supports the inner tube by welding or contact with the outer tube. The discharge lamp according to claim 1, wherein the support member is rotationally symmetric with respect to the lamp axis. A double tube structure discharge lamp with an outer tube and an inner tube.
It comprises a pair of rod-shaped support members arranged between the outer tube and the inner tube.
The support member extends radially from the outer surface of the inner tube and supports the inner tube by welding or contact with the outer tube.
A discharge lamp characterized in that the pair of support members are arranged along the same radial line when viewed from the lamp axis direction. A double tube structure discharge lamp with an outer tube and an inner tube.
It comprises a pair of rod-shaped support members arranged between the outer tube and the inner tube.
The support member extends radially from the outer surface of the inner tube and supports the inner tube by welding or contact with the outer tube.
A discharge lamp characterized in that a pair of the support members are arranged to face each other at a predetermined position along the lamp axis direction. A double tube structure discharge lamp with an outer tube and an inner tube.
It comprises a pair of rod-shaped support members arranged between the outer tube and the inner tube.
The support member welds to the inner tube and extends radially from the outer surface of the inner tube to support the inner tube by welding or contact with the outer tube.
A discharge lamp characterized in that the welded portion between the support member and the outer surface of the inner tube has a curved surface shape in which the diameter becomes larger as the outer surface of the inner tube is closer . A double tube structure discharge lamp with an outer tube and an inner tube.
It comprises a pair of rod-shaped support members arranged between the outer tube and the inner tube.
The support member extends radially from the outer surface of the inner tube and supports the inner tube by welding or contact with the outer tube.
The inner tube has an elliptical cross section and has an elliptical cross section.
A discharge lamp, wherein each pair of support members extends along the long axis direction of the inner tube. A double tube structure discharge lamp with an outer tube and an inner tube.
It comprises a pair of rod-shaped support members arranged between the outer tube and the inner tube.
The support member extends radially from the outer surface of the inner tube and supports the inner tube by welding or contact with the outer tube.
A discharge lamp characterized in that the width of the support member is shorter than the major axis length of the inner tube. The discharge lamp according to any one of claims 1 to 7, wherein the support member is made of the same material as the outer tube or the inner tube. A double tube structure discharge lamp with an outer tube and an inner tube.
It comprises a pair of rod-shaped support members arranged between the outer tube and the inner tube.
The support member extends radially from the outer surface of the inner tube and supports the inner tube by welding or contact with the outer tube.
In the outer tube, a first introduction tube extending along the ramp axis direction is formed at one end, and a second introduction tube extending in a direction different from the ramp axis direction is formed at the other end. ,
A discharge lamp characterized in that a pair of support members is provided at a position closer to the first introduction pipe than to the second introduction pipe. A double tube structure discharge lamp with an outer tube and an inner tube.
It comprises a pair of rod-shaped support members arranged between the outer tube and the inner tube.
The support member extends radially from the outer surface of the inner tube and supports the inner tube by welding or contact with the outer tube.
The outer tube and the inner tube are integrally welded at one lamp end, and a gap is formed between the tip surface of the inner tube and the inner surface of the outer tube at the other end. Being done
A discharge lamp characterized in that the pair of support members is located at a position away from the tip surface of the inner tube by a distance longer than the distance interval along the ramp axial direction of the gap. The discharge lamp according to any one of claims 1 to 10, wherein a film is formed on at least one of the inner surface of the outer tube and the outer surface of the inner tube. The process of forming the first introduction pipe and the second introduction pipe with respect to the outer pipe,
The process of welding a rod-shaped support member to the outer surface of the inner tube,
A step of welding the outer tube and the inner tube to form an arc tube having an integrated double tube structure.
A step of welding the outer tube and the support member before or after welding the outer tube and the inner tube.
A method for manufacturing a discharge lamp, which comprises a step of forming a film on the surface of the arc tube by inflowing and flowing out paint from the first introduction tube.

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