KR102190650B1 - Discharge lamp - Google Patents

Abstract

The discharge lamp of the present invention includes a discharge tube and a pair of electrodes disposed in the discharge tube, and at least one electrode melts when the lamp is lit and convectively is enclosed in an enclosed space, and along the electrode axis in the enclosed space. It is disposed, and has a hollow rectifier having an opening on the bottom side of the closed space and an opening on the top side of the closed space. A flow path of the heat transfer body is formed between the opening at the bottom of the closed space and the opening on the upper surface of the closed space, and the rectifier is disposed so that the electrode shaft passes through the flow path.

Description

Discharge lamp {DISCHARGE LAMP}

TECHNICAL FIELD The present invention relates to a discharge lamp used in an exposure apparatus or the like, and more particularly, to an electrode in which a heat transfer body is enclosed in an electrode.

BACKGROUND ART [0002] In a discharge lamp, an electrode in which a metal having a cooling function is sealed in a closed space formed inside the electrode is known as the output is increased (see Patent Document 1). There, a heat transfer member made of a metal such as silver having a high thermal conductivity and a relatively low melting point is sealed inside the anode. When the electrode temperature rises by lighting the lamp, the heat transfer body dissolves and becomes liquefied. Accordingly, thermal convection occurs in the closed space, and the heat of the electrode tip portion is transported in the direction of the electrode supporting rod on the opposite side.

When the heat transfer body convections when the lamp is lit, a drastic temperature difference occurs in the enclosed space inside the electrode, and there is a fear that high temperature creep deformation may occur. In order to prevent this, a plate-shaped regulating member that traverses in the radial direction so as to pass through the center of the enclosed space, that is, the electrode axis, is disposed to prevent the heat transfer member from rotating along the circumferential direction (see Patent Document 2).

Japanese Patent Laid-Open Publication No. 2004-006246 Japanese Patent Laid-Open Publication No. 2012-028168

If a regulating body crossing the enclosed space is provided, the flow of the heat transfer body that is going to rise from the center passing through the electrode axis is prevented. This is to reduce the heat transport ability to the electrode tip side, and it is not possible to suppress consumption of the electrode tip portion due to an increase in the electrode tip temperature.

Therefore, it is necessary to increase the heat transport capability without disturbing the convection of the heat transfer body.

The discharge lamp of the present invention includes a discharge tube and a pair of electrodes disposed in the discharge tube, and at least one electrode melts when the lamp is lit and convectively is enclosed in an enclosed space, and along the electrode axis in the enclosed space. It is disposed, and has a hollow rectifier having an opening on the bottom of the closed space and an opening on the top of the closed space. Accordingly, a flow path for the heat transfer body is formed between the opening at the bottom of the closed space and the opening at the top of the closed space. And the rectifier is arranged so that the electrode shaft may pass through the flow path. The rectifier is provided with a tube body, for example, and is disposed in a closed space formed in the anode. However, the tube body shall include either a circular cross-sectional shape or a polygonal shape.

When the lamp is lit, the heat transfer body heated in the central portion near the bottom of the closed space rises through the passage. And by thermal convection, most of the heat transfer body near the upper surface of the closed space moves to the space/gap provided between the inner side of the closed space and the outer surface of the rectifier, and descends along the electrode axis. By forming such a flow, the generation of flow along the radial direction is suppressed, and thermal convection is promoted.

As a configuration for promoting the upward flow of the heat transfer body along the electrode axis, for example, the opening on the bottom of the closed space and the opening on the top of the closed space of the rectifier can be directed toward the bottom and the top of the closed space, respectively. Further, since the flow from the radial direction of the closed space is sufficiently blocked, the rectifier can also be disposed in the center. For example, the opening at the bottom of the closed space of the rectifier is located on the lower side of the center along the electrode axis of the closed space, and the opening on the upper side of the closed space of the rectifier is on the top side of the closed space along the electrode axis. It constitutes the rectifier to be located.

Including the electrode tip, its cross-sectional shape is symmetrical with respect to the electrode axis, and the enclosed space can also be disposed coaxially. Considering that the heat transfer body is most heated near the tip of the electrode, it is also possible to arrange the rectifier coaxially with respect to the enclosed space. Here, the term “coaxial” refers to a state in which the axis of the enclosed space passes through the center of the cross section perpendicular to the axial direction of the rectifier or near it.

In consideration of preventing the thermal convection from being locally disturbed, it is preferable that the inner space region forming the flow path and the space region outside it are symmetrical with respect to the vertical section of the electrode axis, and the outer surface of the rectifier and the side surface of the enclosed space It is preferable that the distance along the radial direction of is the same throughout the circumferential direction. For example, it is possible to coaxially arrange a rectifier having a circular cross section as a cylindrical inner space.

Further, it is also possible to smooth thermal convection by arranging the rectifier in a symmetrical position with respect to the electrode axis. For example, by arranging the rectifier so that the center position of the rectifier in the direction of the electrode axis of the rectifier comes at the center position in the electrode axis direction of the inner space, the opening at the bottom of the closed space and the bottom of the closed space are The distance can be made equal to the distance along the electrode axis direction between the opening on the upper surface of the closed space and the upper surface of the closed space.

Considering that the arrangement position along the radial direction of the rectifier affects the occurrence of congestion in thermal convection, the rectifier may be arranged so as to satisfy the following equation.

0.33 ≤ L1/a ≤ 0.84

However, L1 represents the distance from the electrode axis to the rectifier, and a represents the inner radius of the sealed container. By satisfying these conditions, thermal convection occurs effectively. In particular, by arranging so as to satisfy the following conditional expression, a further heat transport effect is exhibited.

0.66 ≤ L1/a ≤ 0.74

On the other hand, when the position of the rectifier along the electrode axis direction is considered, the rectifier can be arranged so as to satisfy the following equation.

0.50 ≤ L2/b ≤ 0.84

However, L2 represents the length of the rectifier, and b represents the length of the sealed container in the axial direction. Accordingly, the heat transport effect is exhibited.

Considering that the risen heat transfer body descends smoothly, the rectifier may have an outlet formed in the vicinity of the upper surface of the closed space along the circumferential direction of the side of the closed space. Further, in consideration of transferring the heat of the rising heat transfer body to the side of the electrode, a slit may be formed with respect to the rectifier along the electrode axis.

After the lamp is turned off, the heat transfer body is preferably solidified in a state where the height in the electrode axial direction of the inner region of the rectifier is lower than that of the outer region of the rectifier.

Advantageous Effects of Invention According to the present invention, it is possible to obtain an electrode encapsulated with a heat transfer body with improved heat transport capability.

1 is a plan view schematically showing a discharge lamp according to a first embodiment.
2 is a schematic cross-sectional view of an anode.
3 is a perspective view of a rectifier.
4 is a diagram showing convection of a heat transfer body.
5 is a schematic cross-sectional view of an anode in a state in which the heating element is solidified.
6 is a perspective view of a rectifier in the second embodiment.
7 is a perspective view of a rectifier in the third embodiment.
8 is a perspective view of a rectifier in the fourth embodiment.
9 is a graph showing changes in electrode tip temperature and maximum flow rate for L1/a.
10 is a graph showing changes in electrode tip temperature and maximum flow rate for L2/b.

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

1 is a plan view schematically showing a discharge lamp according to a first embodiment.

The short arc type discharge lamp 10 is a discharge lamp that can be used as a light source of an exposure apparatus (not shown) for forming a pattern, and has a transparent quartz glass discharge tube (light emitting tube) 12. In the discharge tube 12, a cathode 20 and an anode 30 are disposed to face each other at predetermined intervals.

On both sides of the discharge tube 12, sealing tubes 13A and 13B made of quartz glass are integrally provided with the discharge tube 12 so as to face each other, and both ends of the sealing tubes 13A and 13B are provided with detention tubes 19A. , 19B).

The discharge lamp 10 is disposed along the vertical direction so that the anode 30 is on the upper side and the cathode 20 is on the lower side. Inside the sealing tubes 13A and 13B, conductive electrode support rods 17A and 17B supporting the metallic cathode 20 and anode 30 are provided, and a metal ring (not shown), a metal foil such as molybdenum, etc. It is connected to the conductive lead rods 15A and 15B via (16A, 16B), respectively.

The sealing tubes 13A and 13B are welded to a glass tube (not shown) provided in the sealing tubes 13A and 13B, and accordingly, the discharge space DS filled with mercury and noble gas is sealed.

The lead rods 15A and 15B are connected to an external power supply unit (not shown), and the cathode 20 through the lead rods 15A and 15B, metal foils 16A and 16B, and electrode support rods 17A and 17B , A voltage is applied between the anodes 30. When electric power is supplied to the discharge lamp 10, arc discharge occurs between the electrodes, and bright rays (ultraviolet light) due to mercury are radiated.

2 is a schematic cross-sectional view of an anode. 3 is a perspective view of a rectifier.

As shown in Fig. 2, the anode 30 is constituted by a cylindrical body portion 34 and a conical object tip portion 32 having an electrode tip end surface 30S. The body portion 34 has a structure in which the sealing lid 60 to which the electrode support rod 17B is attached is bonded to each other, and the body portion and the tip portion excluding the sealing lid 60 are formed of the same metal material.

In the body portion 34, a columnar closed space 50 is formed coaxially with respect to the electrode shaft E in the inner center. In the closed space 50, the upper limit is the closed space upper surface 50T in contact with the sealing lid 60 on the electrode supporting rod side, and the lower limit is the closed space bottom surface 50B on the electrode tip end side.

In the closed space 50, the heat transfer body M is enclosed. The heat transfer body M is made of a metal (for example, silver) having a lower melting point than that of the body part 34 and the sealing lid 60, and dissolves when the lamp is lit to become a liquid, and the inside of the closed space 50 Convection in. When the lamp goes out, the heat transfer body M solidifies.

In addition, in the closed space 50, a tubular rectifier 40 is provided coaxially with respect to the closed space 50, and the central axis of the rectifier 40 coincides with the electrode axis E. . The rectifier 40 has a radius L1 and a length L2 along the electrode axis E.

The rectifier 40 is disposed in the closed space 50 so as to be separated by a distance 12 from the closed space bottom surface 50B and a distance l3 from the closed space upper surface 50T along the electrode axis direction. . For example, the rectifier 40 is arranged so that the distances 12 and l3 become the same. On the other hand, the rectifier 40 is separated from the closed space side surface 50S by a distance l1 in the radial direction, and the distance between the rectifier 40 and the closed space side 50S is the same throughout the circumferential direction. Do.

As shown in Fig. 3, the rectifier 40 is constituted by a tube body 40S having an opening 41A serving as an inlet at the bottom of the closed space and an opening 41B serving as an outlet at the upper surface of the closed space. Has been. The tubular body 40S becomes circular in cross section here. In addition, the pipe body 40S is fixed by a rod-shaped or plate-shaped fixing member (not shown). When the fixing member has a plate shape, it is provided along the electrode axis.

The openings 41A and 41B of the pipe body 40S face the closed space bottom surface 50B and the closed space upper surface 50T, respectively. In addition, the tube 40S is disposed near the center W in the electrode axis direction with respect to the electrode axis, and the opening 41A is located on the bottom side of the closed space 50 in the electrode axis direction center W, The opening 41B is located on the upper surface side than the center W in the electrode axis direction.

The pipe body 40S defines a space region V1 serving as a conduit of the pipe body 40S and a space region V2 outside the closed space 50, and two space regions are divided. The tube body 40S is formed from a high melting point metal (for example, tungsten, tantalum, etc.) or an alloy thereof.

4 is a diagram showing convection of a heat transfer body. The heat transport effect by the rectifier is demonstrated using FIG. 4.

During lamp lighting, when the temperature of the electrode tip 32 becomes high due to arc discharge, the melted heat transfer body M rises along the electrode axis E. In particular, by the arc heat at the electrode tip end surface 30S, the heat transfer member M tries to rise at the center of the sealed space 50 centered on the electrode axis E. As a result, the heat transfer member M flows into the opening portion 41A of the rectifier 40 and moves through the pipe inner path.

The heat transfer body M that has risen inside the rectifier 40 moves along the upper surface 50T of the enclosed space, transfers heat to the electrode support bar, and then moves the outer region V2 of the rectifier 40. Descend. At this time, the heat transfer member M descends while discharging heat to the outer surface 34S of the body part 34. Then, the heat transfer member M, which has reached the vicinity of the periphery of the closed space bottom surface 50B, moves to the center thereof, and rises again inside the rectifier 40 by arc heat.

The convection of the heat transfer member M is promoted by the arrangement of the rectifier 40. That is, by installing the tube body 40S coaxially, the flow in the upward direction in the inner region V1 of the rectifier 40 and the flow in the downward direction in the outer region V2 are blocked from each other. It is difficult to generate, and convection is promoted. Since the convection in the vertical direction of the heat transfer body M is not inhibited, the flow rate and flow rate when the heat transfer body M rises increase.

In the configuration in which the rectifier is not provided, due to the influence of the flow in which the heat transfer body M mostly descends near the side of the enclosed space, the area in which the heat transfer body M rises near the center becomes small and narrow, so that the upward flow rate is reduced. It decreases, and the flow rate does not become fast.

However, in the case of the present embodiment, the arrangement of the rectifier 40 increases the flow rate of the heat transfer member M, particularly the flow rate of the upstream flow, and increases the flow rate, so that the heat at the end of the electrode is transferred to the electrode support bar. It is transported efficiently to and suppresses the temperature increase of the electrode tip 32. As a result, the consumption of the electrode tip 32 can be suppressed. In particular, since the rectifier 40 has a sufficient length with respect to the electrode axial direction and is located in the center, the inside of the enclosed space 50 is substantially divided into a conduit and an outer space region thereof, so that a passage is sufficiently secured. Has been.

In addition, the rectifier 40 has an action of blocking the movement of heat along the radial direction of the enclosed space 50, and accordingly, the stress applied to the enclosed space 50 when the heat transfer member M solidifies It can be reduced. Hereinafter, this will be described.

5 is a schematic cross-sectional view of an anode in a state in which the heating element is solidified.

Since the rectifier 40 makes it difficult to transfer the heat of the inner region V1 to the outer region V2, the temperature decrease of the heat transfer member M in the inner region V1 when the lamp is turned off is delayed. , The outer region V2 solidifies relatively quickly. As a result, as shown in Fig. 5, the heat transfer body M in the outer region V2 solidifies and contracts, and the heat transfer body in the inner region V1 solidifies while the liquid level is lower than that.

As a result, concave portions having an appropriate depth are formed in the heat transfer body M that has been solidified and contracted. After that, when the lamp is lit again, the heat transfer member M thermally expands, and stress is applied to the closed space bottom surface 50B and the closed space side surface 50S. However, by forming the concave portion, it is possible to reduce the stress by placing the stress in the central portion. Accordingly, when the electrode is lit, the breakage of the electrode tip 32 does not occur.

In addition, since the heat transfer body in the inner region V1 solidifies while the liquid level is lowered, the heat transfer body in the inner region V1 dissolves relatively quickly and starts convection, so the time required for the entire heat transfer body to dissolve is short. Lose. As a result, it is possible to prevent consumption of the electrode tip 32 during lighting.

In this embodiment, the size of the rectifier 40 is determined so as to satisfy the following equation, and the arrangement position in the radial direction is determined.

0.33 ≤ L1/a ≤ 0.84 (1)

However, the radius along the electrode diameter direction of the rectifier 40 is L1, and the inner radius of the enclosed space 50 is a.

When L1/a is less than 0.33, the inner diameter of the rectifier 40 becomes relatively too small, thereby inhibiting the upward flow of the heat transfer body M. On the other hand, when L1/a is greater than 0.84, a lot of downward flow of the heat transfer member M occurs inside the rectifier 40, thereby inhibiting the upward flow.

In addition, when the range of the following equation is satisfied, a great effect can be obtained for an upward convection increase.

0.66 ≤ L1/a ≤ 0.74 (2)

On the other hand, L2 of the rectifier can obtain the effect of increasing the flow velocity of the heat transfer body by satisfying the following equation.

0.50 ≤ L2/b ≤ 0.84 (3)

However, the length in the axial direction of the rectifier is L2, and the length in the axial direction of the sealed container is b.

If the length of the rectifier in the electrode axis direction is smaller than the range of the above equation, it is impossible to sufficiently block (block) the convection up and down. Moreover, when it is larger than the range of the above formula, the flow in the electrode diameter direction will be inhibited.

As described above, according to the present embodiment, in the discharge lamp 10, the sealed space 50 is formed in the anode 30, and the heat transfer member M is enclosed in the sealed space 50. And, in the closed space 50, the tubular rectifier 40 having a circular cross-section is separated from the closed space side surface 50S, the closed space upper surface 50T, and the closed space bottom surface 50B at distances l1, l3, and l2, respectively. It is arranged coaxially in a state that is separated by a distance.

Next, the electrode which is the 2nd and 3rd embodiment is demonstrated using FIGS. 6 and 7. In the second embodiment, a hole is formed in the rectifying body. About the structure other than that, it is substantially the same as 1st embodiment.

6 is a perspective view of a rectifier in the second embodiment.

The rectifier 140 has a plurality of holes 140R formed at predetermined intervals along the circumferential direction in the vicinity of the upper surface of the enclosed space, that is, at a position on the upper surface side rather than the center along the electrode axis of the enclosed space. Accordingly, the raised heat transfer member M flows out to the outer region V2 through the hole 140R. As a result, convection of the heat transfer member M is promoted, and heat is easily transferred.

Further, by forming the hole 140R, when the heat transfer member M solidifies after the lamp is turned off, the depth of the recess does not become excessive. This is because there is no large temperature difference between the central portion and the lateral vicinity according to the radial direction, so that when the lamp is turned off, it does not rapidly solidify only near the side of the enclosed space.

If the concave portion is too high, the bottom of the concave portion approaches the bottom of the enclosed space, and a strong stress acts on the bottom surface when solidifying. However, since the concave portion has an appropriate height, even if the lamp is repeatedly turned on and off, the stress applied to the enclosed space can be reduced.

In addition, since the passage of the heat transfer body can be secured by the hole 140R, the upper portion of the rectifier can be directly welded to the sealing lid 60 to be fixed. Accordingly, it is possible to create an electrode without using a member for fixing the rectifier.

Next, a third embodiment will be described using FIG. 7. In the third embodiment, a slit is formed in the rectifying body. About the structure other than that, it is the same as 1st embodiment.

7 is a perspective view of a rectifier in the third embodiment.

The rectifier 240 is disposed so that the curved portions 240A and 240B having a semicircular cross-section are relative to each other, and a slit ST is formed between the curved portions 240A and 240B. In other words, the rectifier 240 is the same as the structure in which the tube body shown in the first embodiment is divided into two and arranged so as to create a gap. By forming the slit ST in this way, as in the second embodiment, heat can be easily moved and the height of the recessed portion is appropriate. In addition, it is also possible to have a configuration in which the number of slits is further increased.

Next, a discharge lamp according to a fourth embodiment will be described using FIG. 8. In the fourth embodiment, the cross-sectional shape of the tubular body is polygonal.

8 is a perspective view of a rectifier of a discharge lamp according to a fourth embodiment.

The rectifier 340 is constituted by a tube body 340R having a triangular cross-section, and at least one side of the tube body 340R along the electrode axis direction is fixed to the side of the closed space. In this way, it becomes easy to fix the rectifier by making it a triangular cross section. In addition, about the cross-sectional shape, you may comprise polygons other than a triangle.

Regarding the installation configuration of the rectifier, a configuration that is fixed to one of the upper and lower surfaces of the enclosed space, or both may be provided. In this case, thermal convection is promoted by forming the inlet and outlet of the heat transfer member on the top of the rectifier.

The rectifier is arranged coaxially with respect to the enclosed space and has a symmetrical arrangement structure, but it may be offset by a predetermined distance in the radial direction with respect to the electrode axis (E), and the electrode axis is within the tube. A rectifier may be arranged so as to pass therethrough, and the rectifier may be configured to define an inner region inside the pipe and an outer region outside the pipe.

As for the rectifier, it is also possible to configure other than a tube, and it is also possible to constitute a hollow member in which a flow path is formed along the electrode shaft, such as a thick hollow cylindrical body, and a plurality of flow paths are prescribed inside. , It is okay to be formed. Further, according to the installation state of the discharge lamp, a rectifier may be provided on the cathode or a rectifier may be provided on both electrodes.

<Example>

Hereinafter, examples will be described using Figs. 9 and 10. Here, it was verified by simulation how the position and shape of the rectifier based on the above equations (1) to (3) are affected by the temperature of the electrode tip and the maximum flow velocity of the heating element.

A rectifier having a circular cross section was coaxially arranged in a closed space having a circular cross section, and a rectifier was disposed so that the distance between the upper and lower surfaces of the closed space was the same, and a discharge lamp in which the heat transfer body was sealed in the closed space was set. The diameter of the sealed space (diameter inside the sealed container = 2a) is 30 mm, the diameter of the anode (outer diameter of the electrode) is 40 mm, and the thickness on the tip side (the distance in the electrode axis direction between the bottom of the sealed space and the tip of the electrode) is 10 mm, An anode having a thickness of 5 mm in the cylindrical portion and 35 mm in the height of the enclosed space (b) was modeled, and simulation of the tip temperature and maximum flow rate by a calculator was performed based on the heat quantity assuming an electric power of 14 kW.

At this time, the electrode tip temperature and the maximum flow velocity were calculated while changing the ratio L1/a between the electrode radial distance L1 from the electrode axis to the rectifier and the radius a (=15 mm) inside the sealed container. However, the maximum flow velocity represents the maximum flow velocity of the heating element rising along the electrode axis.

9 is a graph showing changes in electrode tip temperature and maximum flow rate with respect to L1/a.

As shown in Fig. 9, the maximum flow velocity increases in the vicinity of L1/a=0.33 and is large in the vicinity of 0.84 as compared to the case where there is no rectifier. This range of L1/a corresponds to the range of Formula (1). In particular, the range in which the maximum flow rate is maintained at a high level corresponds to 0.66 to 0.74 shown in the above formula (2). Accordingly, it can be seen that an electrode having a closed space that satisfies the above formulas (1) and (2) exhibits an excellent heat transport effect.

Further, the electrode tip temperature and maximum flow velocity were calculated while changing the ratio L2/b of the length L2 of the rectifier in the axial direction of the electrode and the length b (=30 mm) in the axial direction of the sealed container. However, the distance between the rectifier and the bottom of the enclosed space was the same as the distance between the rectifier and the upper surface of the enclosed space.

10 is a graph showing changes in electrode tip temperature and maximum flow rate with respect to L2/b.

As shown in Fig. 10, the maximum flow velocity increases in the vicinity of L2/b = 0.50, and is relatively large in the vicinity of 0.84. This range of L2/b corresponds to the range of Expression (3). Accordingly, it can be seen that an electrode having a closed space satisfying the above formula (3) exhibits an excellent heat transport effect.

With respect to the present invention, various changes, substitutions, and substitutions are possible without departing from the intent and scope of the present invention defined by the appended claims. In addition, in the present invention, it is not intended to be limited to the process, apparatus, manufacture, construction, means, method, and step of the specific embodiment described in the specification. Those skilled in the art will recognize that, from the disclosure of the present invention, devices, means, and methods that substantially achieve functions such as those brought about by the embodiments described herein, or substantially bring equivalent actions and effects, are derived. . Accordingly, it is intended that the appended claims fall within the scope of such devices, means and methods.

This application is an application claiming priority as a basic application for Japanese application (Japanese Patent Application No. 2013-091235, filed on April 24, 2013), and the disclosure contents including the specification, drawings, and claims of the basic application are incorporated herein by reference. Included.

10: discharge lamp
30: anode
40: rectifier
50: confined space

Claims (11)

Discharge tube,
Equipped with a pair of electrodes disposed in the discharge tube,
At least one electrode,
An enclosed space in which the heat transfer element that melts and convections when the lamp is lit is enclosed,
It is disposed along the axis of the electrode in the closed space, and has a hollow rectifier having an opening on the bottom of the closed space and an opening on the top of the closed space,
The discharge lamp, wherein the rectifier is disposed so that an electrode shaft passes through a flow path formed between the opening at the bottom of the closed space and the opening at the top of the closed space. The method of claim 1,
A discharge lamp, characterized in that the opening at the bottom of the closed space and the opening at the top of the closed space of the rectifier face each of the bottom and the top of the closed space. The method according to claim 1 or 2,
The opening on the bottom side of the closed space of the rectifier is located on the bottom side of the closed space than the center along the electrode axis,
The discharge lamp, characterized in that the opening on the upper surface side of the closed space of the rectifier is located on the upper surface side of the closed space than the center along the electrode axis. The method according to claim 1 or 2,
The discharge lamp, wherein the rectifier is disposed coaxially with respect to the closed space. The method of claim 4,
A discharge lamp, wherein a distance along a radial direction between an outer surface of the rectifier and a side surface of the enclosed space is the same throughout the circumferential direction. The method according to claim 1 or 2,
Discharge lamp, characterized in that the distance along the electrode axis direction between the opening at the bottom of the closed space and the bottom of the closed space is the same as the distance along the electrode axis between the opening at the top of the closed space and the upper surface of the closed space . The method of claim 5,
A discharge lamp, wherein the rectifier is disposed so as to satisfy the following equation.
0.33 ≤ L1/a ≤ 0.84
However, L1 represents the distance from the electrode axis to the rectifier, and a represents the inner radius of the sealed container. The method of claim 7,
A discharge lamp, wherein the rectifier is disposed so as to satisfy the following equation.
0.66 ≤ L1/a ≤ 0.74 The method of claim 6,
A discharge lamp, wherein the rectifier is disposed so as to satisfy the following equation.
0.50 ≤ L2/b ≤ 0.84
However, L2 represents the length of the rectifier, and b represents the length in the axial direction of the sealed container. delete The method according to claim 1 or 2,
The discharge lamp, wherein the heat transfer body solidifies after the lamp is turned off, in a state in which the height of the electrode axial direction of the inner region of the rectifier is lower than that of the outer region of the rectifier.

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