JP2002190252A - Manufacturing method of discharge tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for joining a tube-shaped discharge lamp with sealing tubes reliably by melting their joining portions avoiding clogging of the melted ends of the tube-shaped discharge lamp. SOLUTION: The tube-shaped discharge lamp 12 which is made of hard glass having transmission characteristic for ultraviolet rays is joined with the sealing tubes 14 which are made of the same hard glass by melting their joining portions. Tubes 24 which are made of a material having a higher melting point than that of the hard glass are inserted into both ends 12a and 12b of the tube- shaped discharge lamp 12 to dispose them there respectively. After both ends 12a and 12b with the tubes 24 are inserted into bodies 16 of the sealing tubes 14 through holes 26 thereof respectively, portions near both ends 12a and 12b of the tube-shaped discharge lamp 12 and portions near the holes 26 of the sealing tubes 14 are heated to a temperature which is higher than the melting point of the hard glass of which the tube-shaped discharge lamp 12 and the sealing tube 14 constitute and is lower than the melting point of the material of which the tubes 24 constitute. Both portions of the tube-shaped discharge lamp 12 and the sealing tubes 14 are melted and are solidified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a discharge tube, and more particularly to a method for manufacturing a discharge tube suitable for a light source for a backlight of a transmission type display panel such as a liquid crystal display panel.

[0002]

2. Description of the Related Art In a non-self-luminous transmissive display panel such as a liquid crystal display panel, a backlight is provided on the back side, and light from the backlight is irradiated from the back of the transmissive display panel. Is displayed.
FIG. 6 is a schematic cross-sectional view of an essential part showing an example of such a backlight 70, which includes a discharge tube 72 as a light source and a light guide plate 74.

[0003] The discharge tube 72 includes a single elongated arc tube portion 76 made of an ultraviolet ray transmissive glass tube such as a hard glass tube having an ultraviolet ray transmissive characteristic, and both end portions 76a and 76b of the arc tube portion 76.
And a pair of sealing tube portions 78 connected to the arc tube portion 76 in a substantially orthogonal state, and made of the same material as the arc tube portion 76 and made of ultraviolet transmitting glass. Light board 74
And the pair of sealing tube portions 78 are disposed along an end surface orthogonal to the one end surface on which the arc tube portion 76 is disposed. The sealing tube portion 78
It has a straight tube portion 80, and a pair of sealing portions 82 formed by melting and sealing both ends of the tube portion 80. One of the sealing portions 82 has a discharge electrode. 84 and a part of the lead terminal 86 are sealed. The tip of the discharge electrode 84 is a sealing portion.
The base end is connected to one end of a lead terminal 86 buried in the sealing portion 82 while projecting outside the tube 82 to be exposed in the tube body portion 80. The other end of the lead terminal 86 protrudes out of the sealing portion 82. A hole 88 having substantially the same diameter as the inner diameter of the arc tube portion 76 is formed in the tube portion 80 of the sealing tube portion 78, and the inner diameter of the hole 88 matches the inner diameter of the arc tube portion 76. , Sealing tube 78
The airtight container 90 is formed by joining the end surfaces of both ends 76a and 76b of the light emitting tube portion 76 to the outer surface of the sealing tube portion 78 in a state where the light emitting tube portion and the light emitting tube portion 76 are in communication with each other. Airtight container above
90 is filled with a discharge gas for generating ultraviolet rays.
Further, although not shown, a phosphor is attached to the outer surface of the arc tube portion 76.

When a voltage is applied to the discharge tube 72 through the pair of lead terminals 86, a discharge is generated between the discharge electrodes 84, and electrons collide with the ultraviolet radiation gas to emit ultraviolet light of various wavelengths. Is radiated. The emitted ultraviolet light passes through the arc tube portion 76 made of ultraviolet transmitting glass, and excites the phosphor adhered to the outer surface of the arc tube portion 76 to generate visible light. This visible light is diffused and reflected by the light guide plate 74 to form light traveling toward the transmission type display panel (not shown) disposed above the light guide plate 74.

In the above-described discharge tube 72, only the arc tube portion 76 is arranged along one end surface of the light guide plate 74, and the sealing portion 82 that does not contribute to generation of visible light is not arranged. Thus, a large amount of visible light traveling toward one end surface of the light guide plate 74 can be secured. In addition, the discharge tube 72
The arc tube portion 76 and the sealing tube portion 78 are connected in a substantially orthogonal state, and the sealing tube portion 78 is arranged along an end surface orthogonal to one end surface of the light guide plate 74 in which the arc tube portion 76 is arranged. Therefore, the size of the backlight is reduced. The discharge tube 72
In the above, the two members, the arc tube part 76 and the sealing tube part 78, are connected to form the hermetic container 90, and the hermetic container 90 is made of a single member.
90 was not constructed for the following reasons. That is, when the airtight container 90 is formed of a single member, it is necessary to bend the vicinity of both ends of one elongated ultraviolet transmitting glass tube at a substantially right angle, but when the diameter of the ultraviolet transmitting glass tube is small. This is because the inner surfaces of the ultraviolet transmitting glass tubes may come into contact with each other in the vicinity of the bent portion and the inside of the tube may be closed.

In manufacturing the discharge tube 72, an arc tube portion is used.
The joining between the sealing tube portion 78 and the sealing tube portion 78 is performed by the following method. First, the luminous tube portion 76 is attached to the tube portion 80 of the sealing tube portion 78.
A hole 88 having substantially the same diameter as the inside diameter is formed. Next, the tubular body 80
The sealing tube portion 78 and the arc tube portion 76 are communicated with each other by matching the hole 88 of the arc tube with the inner diameter of the arc tube portion 76, and the end faces of both ends 76a and 76b of the arc tube portion 76 are sealed. It is brought into contact with the outer surface of the tube section 78. In this state, both end portions 76 of the arc tube portion 76
The vicinity of the abutting portion between the end surfaces of the a and b and the outer surface of the sealing tube portion 78 is heated to melt the sealing tube portion 78 and the arc tube portion 76 near the abutting portion, and then solidify and seal. The stop tube portion 78 and the arc tube portion 76 are welded and joined.

[0007]

However, in the above-described method for manufacturing the discharge tube 72, since the sealing tube portion 78 and the arc tube portion 76 are welded to each other and joined together, it is difficult to melt or discharge the tube. There has been a problem that the ends 76a and 76b of the arc tube 76 are closed by the heat-deformed sealing tube 78 and arc tube 76. In particular, the tube diameter of the arc tube portion 76 is 1 to 2 mm.
In this case, there is a high possibility that the end portions 76a and 76b are blocked by the melted or thermally deformed sealing tube portion 78 and the arc tube portion 76.

The present invention has been devised in view of the above problems, and has as its object to block the inside of the end of the arc tube at the time of welding and joining the sealing tube and the arc tube. An object of the present invention is to realize a method of manufacturing a discharge tube that can securely join an arc tube portion and a sealing tube portion without performing any process.

[0009]

According to a first aspect of the present invention, there is provided a method for manufacturing a discharge tube, comprising the steps of: forming a discharge tube made of an ultraviolet transmitting glass; A sealing tube portion having a pair of sealing portions formed by melting and sealing both ends of the opening is connected to each other to form an airtight container, and a discharge gas for generating ultraviolet light is sealed in the airtight container. And a method of manufacturing a discharge tube in which a discharge electrode is arranged near one of the sealed tube portions, wherein the arc tube portion and the sealed tube portion are connected by welding. The connection by this welding is, first, in both ends of the arc tube part,
A cylindrical body made of a material having a melting point higher than the melting point of the ultraviolet transmitting glass constituting the arc tube portion is inserted and arranged, and then both ends of the arc tube portion are formed in the tube portion of the sealing tube portion. Inserted into the tube through the hole, then, near both ends of the arc tube and the hole near the sealing tube, higher than the melting point of at least one of the constituent materials of the arc tube and the sealing tube, Further, the heating is performed at a temperature lower than the melting point of the cylindrical body, and at least one of the arc tube portion and the sealing tube portion is melted and then solidified.

In the invention according to the first aspect, a cylindrical body made of a material having a higher melting point than the melting point of the ultraviolet transmitting glass constituting the arc tube portion is inserted and arranged in both ends of the arc tube portion. By heating at a temperature higher than the melting point of at least one of the constituent materials of the sealing tube portion and lower than the melting point of the cylindrical body, at least one of the arc tube portion and the sealing tube portion is melted and then solidified. Since the end of the arc tube is welded to the sealing tube, the tubular body does not melt even if the end of the arc tube is melted or thermally deformed during welding. Therefore, it is possible to prevent the inside of the end portion from being closed by the arc tube portion that has been melted or thermally deformed. In addition, since both ends of the arc tube are inserted into the tube, respectively, even if the sealing tube is melted or thermally deformed at the time of welding, the melted or thermally deformed sealing tube is deformed by the arc tube. Is prevented from entering from the end portion and closing the inside of the end portion.

According to a second aspect of the present invention, there is provided a method for manufacturing a discharge tube according to the first aspect, wherein the sealing tube portion is made of an ultraviolet transmitting glass of the same material as the arc tube portion. Heat both ends of the arc tube portion and the vicinity of the hole of the sealing tube portion at a temperature higher than the melting point of the ultraviolet transmitting glass constituting the arc tube portion and the sealing tube portion, and lower than the melting point of the cylindrical body. After melting both the arc tube portion and the sealing tube portion, they are solidified.

In the invention according to claim 2, the sealing tube portion is made of the same material as that of the arc tube portion, and is made of ultraviolet transmitting glass.
Heat both ends of the arc tube portion and the vicinity of the hole of the sealing tube portion at a temperature higher than the melting point of the ultraviolet transmitting glass constituting the arc tube portion and the sealing tube portion, and lower than the melting point of the cylindrical body. ,
Both the arc tube part and the sealing tube part are solidified after melting,
For welding the end of the arc tube portion and the sealing tube portion,
Also in this case, the cylindrical body does not melt even if the end of the arc tube part is melted or thermally deformed during welding. Therefore, it is possible to prevent the inside of the end portion from being closed by the arc tube portion that has been melted or thermally deformed. Further, since both ends of the arc tube are inserted into the tube, respectively, during welding, the melted or thermally deformed sealing tube may enter from the end of the arc tube and block the inside of the end. Is prevented.

According to a third aspect of the present invention, in the method for manufacturing a discharge tube according to the first or second aspect, the tubular body is made of a light-transmitting material. I do. In this manner, by forming the cylindrical body from a light-transmitting material, the emission of ultraviolet light from the arc tube is not blocked by the cylindrical body, and the emission area of the arc tube does not decrease. .

[0014]

FIG. 1 is a sectional view of a discharge tube 10 manufactured by the manufacturing method of the present invention.
Is connected to the arc tube portion 12 made of a hard glass tube having an ultraviolet transmission characteristic, and to both ends 12a and 12b of the arc tube portion 12 in a state substantially orthogonal to the arc tube portion 12, and And a pair of sealing tube portions 14 made of hard glass having the same material as the above and having ultraviolet transmission characteristics. The sealing tube 14
Has a straight tube portion 16 and a pair of sealing portions 18a and 18b formed by melting and sealing both ends of the tube portion 16. The pair of sealing portions 18a , 18b
The discharge electrode 20 and a part of the lead terminal 22 are sealed in 18a. The tip of the discharge electrode 20 is sealed at a sealing portion 18a.
It protrudes outside and is exposed in the tube body portion 16, and its base end is connected to one end of a lead terminal 22 embedded in the sealing portion 18a. The other end of the lead terminal 22 is connected to the sealing portion 18a.
It protrudes outside.

Further, both end portions 12a, 12b of the arc tube portion 12 are provided.
Inside, cylindrical bodies 24, 24 are inserted and arranged, respectively.
The cylindrical body 24 is made of a hard glass (melting point of about 800 degrees) constituting the arc tube portion 12 and a quartz glass (melting point of about 2000 degrees), which is a material having a high melting point and translucency. I have. As described above, by forming the cylindrical body 24 from a material having translucency such as quartz glass, the arc tube part 12
The emission of ultraviolet light is not blocked by the cylindrical body 24, and the emission area of the arc tube portion 12 is not reduced. However, as the material forming the cylindrical body 24, an opaque material such as ceramic or aluminum having a higher melting point than the hard glass forming the arc tube part 12 may be used. In this case, it is desirable to make the length of the tubular body 24 as short as possible in order to minimize the decrease in the light emitting area of the arc tube section 12. The cylindrical body 24 may be inserted and arranged with a part thereof slightly projecting from the ends 12a and 12b of the arc tube part 12.

A hole 26 having substantially the same diameter as the outer diameter of the arc tube portion 12 is formed in the tube portion 16 of the sealing tube portion 14.
The end portions 12a and 12b of the arc tube portion 12 are inserted into the tube body portion 16 so that the sealing tube portion 14 and the arc tube portion 12 communicate with each other. , 12b and the sealing tube 14 are joined to form an airtight container 28. In the airtight container 28, as a discharge gas for generating ultraviolet light,
For example, it is filled with an ultraviolet emitting gas obtained by mixing argon and mercury, or an ultraviolet emitting gas mainly containing xenon. Although not shown, the arc tube section
A phosphor is adhered to the outer surface of 12.

When a voltage is applied to the discharge tube 10 through the pair of lead terminals 22, a discharge is generated between the discharge electrodes 20, and electrons collide with the ultraviolet radiation gas to emit ultraviolet light of various wavelengths. Is radiated. The emitted ultraviolet light passes through the arc tube section 12 made of ultraviolet transmitting glass, and excites the phosphor adhered to the outer surface of the arc tube section 12 to generate visible light.

Next, a method for manufacturing the discharge tube 10 will be described with reference to FIGS. First, the discharge electrode 20 and the lead terminal 22 are connected in advance, and the connected discharge electrode 20 is connected.
Then, the lead terminal 22 is inserted into the hard glass tube 30 through an opening on one end side of the hard glass tube 30 serving as the base of the sealing tube portion 14.
At this time, the other end of the lead terminal 22 is connected to the hard glass tube.
30 so that it protrudes outside. In this state, the discharge electrode 20 and the lead terminal 22 in the hard glass tube 30
The sealing portion 18a is formed by heating and melting the end on the side where the is inserted, and then cooling and solidifying.

Next, a hole 26 having substantially the same diameter as the outer diameter of the arc tube portion 12 is formed in the tube portion 16 of the hard glass tube 30. The holes 26 can be formed by blowing a gas such as nitrogen gas or air while heating and softening the tube portion 16 of the hard glass tube 30. The hole 26 can also be formed by irradiating a laser beam to the tube portion 16 of the hard glass tube 30 to evaporate the hard glass forming the tube portion 16. In this case, a shielding member for shielding the laser beam is inserted into the tube portion 16 in order to prevent the laser beam from being irradiated on the tube portion 16 located behind the hole 26 forming portion in the tube portion 16. There is a need. Further, the hole 26, while containing water containing fine sand particles, continuously flowing on the surface of the tubular body 16, applying ultrasonic vibration to the water flowing through the hole 26 forming location, contained in the water It can also be formed by shaving the tube portion 16 with sand particles. Alternatively, the hole 26 can be formed by melting the tube portion 16 of the hard glass tube 30 using a micro burner.
In the case of the method of forming the hole 26 using a laser beam, or the method of forming the hole 26 by ultrasonically oscillating water containing fine sand particles, the shape and size of the hole 26 can be relatively easily adjusted. Can be controlled.

Next, after inserting the tubular body 24 into the ends 12a and 12b of the arc tube portion 12, as shown in FIG. 2, the end portion 12a of the arc tube portion 12 is inserted into the hole 12a. From 26, the hard glass tube 30 is inserted into the tube portion 16 to make the arc tube portion 12 and the hard glass tube 30 communicate with each other. Then, as shown in FIG. 3, the burner 32 causes the end portion 12a of the arc tube portion 12 and the vicinity of the hole 26 of the hard glass tube 30 to move in the vicinity of the arc tube portion 12 and the hard glass tube 30.
After heating at a temperature higher than the melting point of the hard glass and lower than the melting point of the cylindrical body 24 to melt both the arc tube portion 12 and the hard glass tube 30, they are cooled and solidified to form an arc tube. The part 12 and the hard glass tube 30 are welded and joined. As described above, since the arc tube portion 12 and the sealing tube portion 14 are made of the same hard glass, they have the same thermal expansion coefficient, and have extremely good bonding properties.

After the hard glass tube 30 is joined to both ends 12a and 12b of the arc tube portion 12, the hard glass tube 30 is connected to the other end of the hard glass tube 30 via an exhaust device (not shown).
After the inside of the arc tube 30 and the arc tube section 12 are evacuated to a high vacuum state, an ultraviolet radiation gas is filled. Then, as shown in FIG.
The other end of the hard glass tube 30 is heated and melted by the burner 32,
By sealing off, the sealing portion 18b is formed. Finally, if a phosphor is attached to the outer surface of the arc tube portion 12, the discharge tube 10 shown in FIG. 1 is completed.

As described above, in the present invention, the arc tube section
A cylindrical body 24 made of a material having a higher melting point than the hard glass constituting the arc tube portion 12 is inserted and disposed in the ends 12a and 12b of the arc tube 12, and the arc tube portion 12 and the sealing tube portion 14 (hard tube). Glass tube
Heating at a temperature higher than the melting point of the hard glass constituting 30) and lower than the melting point of the cylindrical body 24 to perform welding between the ends 12a and 12b of the arc tube portion 12 and the sealing tube portion 14. Therefore, even when the ends 12a and 12b of the arc tube part 12 are melted during welding, the tubular body 24 does not melt. Therefore, it is possible to prevent the end portions 12a and 12b from being closed by the arc tube portion 12 that has been melted or thermally deformed. Further, the end portion 12a of the arc tube portion 12,
Since the tube 12b is inserted into the tube 16, the melted or thermally deformed sealing tube 14 enters the ends 12a and 12b of the arc tube 12 and closes the ends 12a and 12b. Can also be prevented.

In the above, the sealing tube 14 is connected to the arc tube 12
Although the description has been given of the case where the sealing tube 14 is made of a material different from that of the arc tube 12, the present invention is applicable. For example, the sealing tube portion 14 may be made of inexpensive soft glass (with a melting point of about 600 degrees) while having a lower melting point than the above hard glass and being easy to process. In this case, the ends 12a, 12b of the arc tube part 12
The sealing tube portion 14 is bonded to the sealing tube portion 14 by heating and melting the sealing tube portion 14 at a temperature higher than the melting point of the soft glass constituting the sealing tube portion 14, and then cooling and solidifying the sealing tube portion 14. Arc tube part
The welding is performed by welding to the 12 ends 12a and 12b. In this case, since the heating is performed at a temperature considerably higher than the melting point of the soft glass in order to quickly melt the sealing tube portion 14, the arc tube portion is heated.
The hard glass constituting 12 may also be thermally deformed. However, as described above, the cylindrical body 24 made of a material having a higher melting point than the hard glass constituting the arc tube part 12 is inserted and arranged in the ends 12 a and 12 b of the arc tube part 12, The deformed arc tube part 12 does not block the insides of the ends 12a and 12b. Also, the ends 12a and 12b of the arc tube part 12 are
Since it is inserted into the tube body 16, the molten sealing tube 14
Enters through the ends 12a and 12b of the arc tube part 12 and
Blocking of the insides a and 12b is also prevented.

Further, in the above description, hard glass having ultraviolet transmission characteristics has been described as an example of the glass constituting the arc tube portion 12, but the glass is not limited thereto.
For example, any glass having ultraviolet transmission characteristics, such as quartz glass, can be used as a material for forming the arc tube portion 12.

FIG. 5 is a schematic sectional view of a main part showing a case where the above-mentioned discharge tube 10 of the present invention is used as a light source for a backlight of a transmission type display panel. As shown in FIG.
Ten arc tube sections 12 are arranged along one end surface of the light guide plate. Also, one sealing portion 18 in each sealing tube portion 14
b and the tube portion 16 closer to the sealing portion 18b than the hole 26 is disposed along an end surface orthogonal to one end surface of the light guide plate 34 in which the arc tube portion 12 is disposed, and the other sealing portion 18a The tube portion 16 on the sealing portion 18 a side from the location where the hole 26 is formed is disposed so as to protrude from the end of the light guide plate 34. Then, between the sealing portion 18a and the tube portion 16 on one end side of the arc tube portion 12 and the sealing portion 18a and the tube portion 16 on the other end side, which are arranged to protrude from the end of the light guide plate 34. A drive unit 36 including a drive circuit and the like for the discharge tube 10 is arranged in the space (3) to reduce the size of the backlight.
Thus, when a voltage is applied to the discharge tube 10 via the pair of lead terminals 22, a discharge is generated between the discharge electrodes 20, and electrons collide with the ultraviolet radiation gas to emit ultraviolet rays of various wavelengths. Because The emitted ultraviolet light passes through the arc tube part 12, excites the phosphor adhered to the outer surface of the arc tube part 12, and generates visible light. This visible light is diffusely reflected by the light guide plate 34, and is formed as light traveling toward the transmission type display panel (not shown) disposed above the light guide plate 34.

[0026]

According to the first aspect of the present invention, a cylindrical body made of a material having a higher melting point than the melting point of the ultraviolet transmitting glass constituting the arc tube is inserted and arranged in both ends of the arc tube. By heating at a temperature higher than the melting point of at least one of the constituent materials of the arc tube portion and the sealing tube portion and lower than the melting point of the cylindrical body, at least one of the arc tube portion and the sealing tube portion is melted. After solidification, the end of the arc tube portion and the sealing tube portion are welded to each other, so that during welding, the cylindrical body does not melt even if the end portion of the arc tube portion is melted or thermally deformed. Absent. Therefore, it is possible to prevent the inside of the end portion from being closed by the arc tube portion that has been melted or thermally deformed. Also,
Since both ends of the arc tube are inserted into the tube, respectively, even if the sealing tube is melted or thermally deformed at the time of welding, the melted or thermally deformed sealing tube is kept at the end of the arc tube. It is possible to prevent the inside of the end portion from being closed by entering from the portion.

Further, in the invention according to claim 2, the sealing tube portion is made of ultraviolet transmitting glass of the same material as the arc tube portion, and both ends of the arc tube portion and the hole of the sealing tube portion are provided. The neighborhood
Heating is performed at a temperature higher than the melting point of the ultraviolet transmitting glass constituting the arc tube portion and the sealing tube portion, and lower than the melting point of the cylindrical body, so that both the arc tube portion and the sealing tube portion are melted and solidified. Thus, the end portion of the arc tube portion is welded to the sealing tube portion. Even when the end portion of the arc tube portion is melted or thermally deformed during welding, the tubular body does not melt. Therefore, it is possible to prevent the inside of the end portion from being closed by the arc tube portion that has been melted or thermally deformed. Further, since both ends of the arc tube are inserted into the tube, respectively, during welding, the melted or thermally deformed sealing tube may enter from the end of the arc tube and block the inside of the end. Can be prevented.

Further, in the invention according to claim 3,
Since the cylindrical body inserted and arranged in the end of the arc tube portion is made of a translucent material, the emission of ultraviolet light from the arc tube portion is not interrupted by the above-mentioned cylindrical body, and the emission area of the arc tube portion is reduced. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a discharge tube according to the present invention.

FIG. 2 is an explanatory view showing a method for manufacturing a discharge tube according to the present invention.

FIG. 3 is an explanatory view showing a method for manufacturing a discharge tube according to the present invention.

FIG. 4 is an explanatory view showing a method for manufacturing a discharge tube according to the present invention.

FIG. 5 is a schematic cross-sectional view of a main part showing a case where the discharge tube according to the present invention is used as a light source of a backlight.

FIG. 6 is a schematic cross-sectional view of a main part showing an example of a conventional backlight.

[Explanation of symbols]

 10 discharge tube 12 arc tube part 14 sealed tube part 16 tube part 18a sealed part 18b sealed part 20 discharge electrode 22 lead terminal 24 cylindrical body 26 hole 28 airtight container 30 rigid glass tube

Claims (3)

[Claims] 1. A sealed tube portion having a tube portion and a pair of sealing portions formed by melting and sealing both ends of the tube portion at both ends of an arc tube portion made of ultraviolet transmitting glass. Are connected to each other to form a hermetic container, a discharge gas for generating ultraviolet light is sealed in the hermetic container, and a discharge electrode is arranged in the vicinity of one sealing portion of each of the sealing tube portions. In the method for manufacturing a discharge tube, the connection between the arc tube portion and the sealing tube portion is performed by welding.
A cylindrical body made of a material having a melting point higher than the melting point of the ultraviolet transmitting glass constituting the arc tube portion is inserted and arranged in both ends of the arc tube portion, and then both ends of the arc tube portion are sealed. Inserted into the tube portion through the hole formed in the tube portion of the stop tube portion, then, near both ends of the arc tube portion and the hole near the sealing tube portion,
Heating was performed at a temperature higher than the melting point of at least one of the constituent materials of the arc tube portion and the sealing tube portion, and lower than the melting point of the cylindrical body, and at least one of the arc tube portion and the sealing tube portion was melted. Thereafter, the method is performed by solidifying the discharge tube. 2. The sealing tube section is made of an ultraviolet transmitting glass of the same material as the arc tube section, and both ends of the arc tube section and the vicinity of the hole of the sealing tube section are formed by the arc tube section and the sealing tube. Heating at a temperature higher than the melting point of the ultraviolet transmitting glass constituting the part and lower than the melting point of the cylindrical body, melting both the arc tube part and the sealing tube part, and then solidifying. Item 1
3. The method for manufacturing a discharge tube according to claim 1. 3. The method for manufacturing a discharge tube according to claim 1, wherein the tubular body is made of a translucent material.