JP4429129B2 - Method for producing mercury-free arc tube for discharge lamp device and mercury-free arc tube for discharge lamp device - Google Patents

Description

The present invention inserts an electrode assembly, in which an electrode rod and a molybdenum lead wire are connected and integrated via a molybdenum foil, from both ends of the glass tube, and pinch-seals the electrode assembly insertion site of the glass tube. The present invention relates to a method of manufacturing a mercury-free arc tube for a discharge lamp apparatus that forms a sealed chamber part in which a metal rod is enclosed in the center of a tube and metal halide is enclosed but mercury is not enclosed as an enclosure, and in particular, a secondary pinch. The lead wire of the electrode assembly on the seal side is formed with a bent portion having a width larger than the inner diameter of the glass tube. The secondary pinch is held in a predetermined position in the glass tube while the electrode assembly on the secondary pinch seal side is held by itself. The present invention relates to a method for manufacturing a mercury-free arc tube to be sealed.

  FIG. 7 shows a conventional discharge lamp apparatus. The front end of the arc tube 5 is supported by a single lead support 2 protruding forward of the insulating base 1, and the rear end of the arc tube 5 is a recess 1 a of the base 1. Further, the rear end portion of the arc tube 5 is held by a metal support member S fixed to the front surface of the insulating base 1.

  The front end side lead wire 8 led out from the arc tube 5 is fixed to the lead support 2 by welding, while the rear end side lead wire 8 passes through the bottom wall 1b formed with the recess 1a of the base 1 and is provided on the bottom wall 1b. The terminal 3 is fixed by welding. Reference numeral G denotes a cylindrical ultraviolet shielding glove that cuts ultraviolet components in a wavelength range harmful to the human body in the light emitted from the arc tube 5, and is welded and integrated with the arc tube 5.

As shown in FIG. 8, the arc tube 5 is formed with a sealed chamber portion 5a in which electrode rods 6 and 6 are provided between a pair of front and rear pinch seal portions 5b and 5b and mercury or a metal halide is enclosed. It has a structured. In the pinch seal portion 5b, an electrode assembly A in which a tungsten electrode rod 6 protruding into the sealed chamber portion 5a and a molybdenum lead wire 8 led out from the pinch seal portion 5b are connected and integrated via a molybdenum foil 7, A ′ is sealed to ensure airtightness in the sealed chamber portion 5a.

As a manufacturing method of the arc tube 5, first, as shown in FIG. 9A, the opening end side below the cylindrical glass tube W in which the chamber portion w2 is formed in the middle of the linear extension portion w1. Then, an electrode assembly A in which the electrode rod 6, the molybdenum foil 7 and the lead wire 8 are connected and integrated is inserted, and the chamber portion w2 is inserted.
A primary pinch seal is applied to a position q1 in the vicinity. Next, as shown in FIG. 9B, mercury is supplied to the chamber portion w2 through the mercury supply nozzle N inserted into the glass tube W from the upper opening end side. Next, as shown in FIG. 9 (c), metal halide pellets P and the like are introduced into the chamber portion w2, and subsequently, a bent portion 8a is formed in the lead wire 8 as shown in FIG. 9 (d). The other electrode assembly A ′ (see FIG. 10) is inserted and self-held. That is, in the electrode assembly A ′ inserted into the glass tube W, a bent portion 8a having a width wider than the inner diameter of the glass tube W formed on the lead wire 8 is pressed against the inner peripheral surface of the glass tube W. It is self-held at that position inserted by force. Subsequently, the opening end side of the glass tube W is temporarily sealed using a burner. Further, the electrode assembly A ′ insertion site of the glass tube W is subjected to a secondary pinch seal, the temporary sealing side of the glass tube W is cut at a predetermined position, and the lead wire 8 is led out from the glass tube W.

  Mercury that acts as a buffer is enclosed in the sealed chamber portion 5a of the conventional arc tube, but mercury is an environmentally hazardous substance and is sealed to meet the social needs to reduce the environmental pollution on the earth as much as possible. Mercury-free arc tubes that do not contain mercury in the chamber portion 5a are being actively developed.

  The following problems were pointed out in the process of manufacturing the mercury-free arc tube by the conventional method, that is, in the process of manufacturing the mercury-free arc tube by the method of omitting the mercury supply process shown in FIG. 9B. .

  That is, when the electrode assembly A ′ is inserted into the glass tube W, the glass piece or molybdenum piece scraped by rubbing between the bent portion 8a of the lead wire 8 and the inner peripheral surface of the glass tube W falls, and the secondary pinch is dropped. By sealing, these foreign substances may be mixed in the sealed chamber portion 5a. If glass pieces or molybdenum pieces that should not exist are present as foreign matter in the sealed chamber part 5a, the luminous flux maintenance factor decreases or flicker phenomenon (arc disappearance) occurs. Therefore, there is a problem that the yield in manufacturing the arc tube is poor.

  In the method of manufacturing an arc tube containing mercury, it is difficult to insert the mercury supply nozzle N into the glass tube W in which the electrode assembly A ′ is inserted. Therefore, the electrode assembly A ′ insertion process is performed after the mercury supply process. However, it was considered that a certain amount of foreign matter was inevitably mixed in the sealed chamber portion 5a.

However, since a mercury supplying step is not necessary for manufacturing a mercury-free arc tube, in the conventional method, the electrode assembly A ′ that has been inserted downward from the open end of the glass tube W facing upward is directed downward. If the glass tube W is inserted upward from the open end of the glass tube W, the glass piece or molybdenum piece scraped by the lead wire 8 (the bent portion 8a thereof) and the glass tube W scraped and dropped by its own weight. The electrode assembly A ′ is self-held in the glass tube W even if it is discharged naturally from the open end and then the open end of the glass tube W is directed upward to insert the metal halide pellets P. Therefore, the electrode assembly A ′ does not move freely, and there is a sufficient gap between the glass tube W and the electrode assembly A ′, so that the falling of the metal halide pellets P is prevented. The inventor thought it was not. And when this method was adopted, it was confirmed that the method was very effective, and thus the present invention was proposed.

  The present invention has been made in view of the above-mentioned problems of the prior art and the above-mentioned knowledge of the inventor. The object of the present invention is to produce a mercury-free arc tube for a discharge lamp device in which a foreign substance does not enter the sealed chamber and discharge. It is to provide a mercury-free arc tube for a lamp device.

In order to achieve the above object, in the method for manufacturing a mercury-free arc tube for a discharge lamp device according to claim 1, a first electrode assembly in which an electrode rod and a molybdenum lead wire are connected and integrated via a molybdenum foil is provided. A primary pinch seal step of inserting from one end side of the glass tube and pinch-sealing the first electrode assembly insertion site in the glass tube;
An enclosure supply step for supplying a predetermined pellet-shaped enclosure material made of a metal halide into the glass tube from the other end side of the glass tube opening;
Connect the electrode rod and the molybdenum lead wire through a molybdenum foil and integrate the second electrode assembly in which the bent portion having a width larger than the inner diameter of the glass tube is formed on the lead wire, the other end side of the glass tube opening A second electrode assembly insertion step of inserting the first electrode assembly and holding it in a predetermined position in the glass tube;
A secondary pinch sealing step for pinch sealing the second electrode assembly insertion site in the glass tube;
A method for producing a mercury-free arc tube for a discharge lamp device comprising:
After the primary pinch seal step, before the inclusion supply step, the electrode assembly insertion step of inserting the second electrode assembly from the other end side of the glass tube opened downward is configured. .

  (Operation) In the step of inserting the second electrode assembly, since the second electrode assembly is inserted upward from the opening end of the glass tube facing downward, the bent portion of the lead wire and the glass tube W rub against each other. Even if a piece or molybdenum piece is scraped off, it falls inside the glass tube W by its own weight and is naturally discharged out of the glass tube W from the open end.

  In the enclosing material supply process, the opening end of the glass tube facing downward in the process of inserting the second electrode assembly is directed upward. However, the second electrode assembly is self-held in the glass tube. Therefore, the second electrode assembly does not move in the glass tube without permission.

In addition, in the enclosure supply process, there is a gap around the second electrode assembly in the glass tube that allows the pellet-shaped encapsulation object (metal halide) to sufficiently pass therethrough. The pellet-like encapsulated material (metal halide) charged from the end falls within the glass tube without being blocked by the second electrode assembly, and reaches the intended position.

  In this way, no mercury (glass piece or molybdenum piece) is present in the glass tube when pinching and sealing the second electrode assembly insertion site in the glass tube (in the secondary pinch sealing process), so the manufactured mercury-free Foreign matter (glass pieces or molybdenum pieces) does not enter the sealed chamber of the arc tube.

In a mercury-free arc tube for a discharge lamp apparatus according to claim 2, a sealed chamber portion manufactured by the method according to claim 1 and having an electrode rod placed in the center of a glass tube and filled with a metal halide is provided. The mercury-free arc tube for a discharge lamp apparatus provided was configured such that the amount of foreign matter in the sealed chamber portion of the arc tube was 0.125 × 10 ⁻⁶ cm ³ or less.

(Operation) When the amount of foreign matter in the sealed chamber portion of the mercury-free arc tube is 0.125 × 10 ⁻⁶ cm ³ or less, as shown in FIGS. (Arc disappearance) does not occur, and a high luminous flux maintenance factor can be obtained.

  According to the method for manufacturing a mercury-free arc tube for a discharge lamp device according to claim 1, glass pieces and molybdenum pieces are not enclosed as foreign matter in the sealed chamber portion of the manufactured mercury-free arc tube, so that the defective product generation rate is increased accordingly. This reduces the yield in producing mercury-free arc tubes.

  According to the mercury-free arc tube for a discharge lamp device according to claim 2, since there is no possibility of occurrence of flicker phenomenon (arc extinction) due to contamination of foreign matter in the sealed chamber portion, light color and luminous flux can be used even for long-term use. A mercury-free arc tube for a discharge lamp device is provided that does not decrease (has a high luminous flux maintenance factor).

  Next, embodiments of the present invention will be described based on examples.

1 to 6 show an embodiment of the present invention, FIG. 1 is a longitudinal sectional view of a mercury-free arc tube for a discharge lamp apparatus according to an embodiment of the present invention, and FIG. 2 is a production of the arc tube. It is process explanatory drawing which shows a process, (a) is explanatory drawing of the temporary pinch sealing process in a primary pinch sealing process, (b) is explanatory drawing of this pinch sealing process in a primary pinch sealing process, (c) is a 2nd electrode. Explanatory drawing of assembly insertion process, (d) is an explanatory view of a process for supplying an encapsulated material (metal halide) such as a luminescent substance, (e) is an explanatory view of a chip-off process, and (f) is a secondary pinch sealing process. It is explanatory drawing. 3 is a cross-sectional view showing a gap for passing pellets around the second electrode assembly inserted in the glass tube, FIG. 4 is a diagram showing the relationship between the amount of foreign matter mixed and the flicker occurrence rate, and FIG. 5 is the amount of foreign matter mixed in FIG. 6 is a diagram showing a comparison of the contamination state in the sealed chamber portion of the arc tube manufactured by the method of the present embodiment and the conventional method, respectively.

  In these drawings, the discharge lamp device to which the arc tube 10 is attached is the same as the conventional structure shown in FIG. 7, and the description thereof is omitted.

The arc tube 10 has a pinch-sealed portion near the spherical bulging portion w _{2 of} the circular pipe-shaped quartz glass tube W in which a spherical bulging portion w ₂ is formed in the longitudinal direction of the linear extending portion w _1. Structure in which pinch seal portions 13A and 13A ′ (primary pinch seal portion 13A and secondary pinch seal portion 13A ′) having a rectangular cross section are formed at both ends of an ellipsoidal chipless sealed chamber portion 12 forming a space. In the sealed chamber portion 12, the electrode rods 6 and 6 made of tungsten constituting the discharge electrode are arranged to face each other, and the electrode rods 6 and 6 are molybdenum foils sealed to the pinch seal portions 13A and 13A ′. 7, lead wires 8 and 8 made of molybdenum connected to the molybdenum foils 7 and 7 are led out from the ends of the pinch seal portions 13A and 13A ′, and the lead wires 8 and 8 are non-pinch seal portions. Pipe shape The shape portion 14 is inserted and extends to the outside.

The external structure of the arc tube 10 is not different from the conventional mercury-containing arc tube 5 shown in FIG. 8 at first glance. However, in the sealed chamber portion 12, a rare gas for starting and a metal halide for main light emission are included. In addition, auxiliary metal halides and the like that act as buffer substances instead of mercury are enclosed. That is, the arc tube 10 is configured as a so-called mercury-free arc tube in which an auxiliary metal halide in place of mercury is sealed, unlike a conventional mercury-containing arc tube in which mercury, which is an environmentally hazardous substance, is sealed. Various proposals have been made for specific structures of the enclosed substance in the sealed chamber section 12 in, for example, Japanese Patent Application Laid-Open Nos. 11-238488 and 11-3007048.

Further, since the arc tube 10 is manufactured by the method shown in FIG. 2, foreign matter (glass pieces or molybdenum pieces) is completely mixed into the sealed chamber portion 12 which has been a problem in the conventional manufacturing method. Even if it is mixed, the mixed amount is limited to a very small amount of 0.125 × 10 ⁻⁶ cm ³ or less, so that flicker occurs and the luminous flux maintenance factor decreases. There is no fear.

That is, in the conventional method, when the second electrode assembly A ′ is inserted into the glass tube W, the bent portion 8a of the lead wire 8 and the inner peripheral surface of the glass tube W are scraped and scraped off. Although the piece falls and enters the sealed chamber portion 5a as a foreign substance, the inventor believes that the size of the foreign substance (glass piece or molybdenum piece) is 0.05 mm (volume conversion 0.125 × 10 ⁻⁶ cm ³ ) or less. Is small, 0.05 to 0.1 mm (volume conversion 0.125 × 10 ⁻⁶ to 1 × 10 ⁻⁶ cm ³ ) is medium, and 0.1 mm (volume conversion 1 × 10 ⁻⁶ cm ³ ) or more is large When the relationship between the amount of foreign matter mixed into the sealed chamber, the flicker generation rate, and the luminous flux maintenance rate was examined, it was found that there was a relationship as shown in FIGS.

From these figures, when the amount of foreign matter (glass pieces or molybdenum pieces) is 0.05 mm or less (volume conversion 0.125 × 10 ⁻⁶ cm ³ ) or less, the flicker occurrence rate is almost 0 (FIG. 4). 2) and the luminous flux maintenance factor (after 1000 hours of lighting) is 80% or more, which is a reference value required for a general arc tube for a discharge lamp device (see FIG. 5). Therefore, the manufacturing process shown in FIG. By adopting, the amount of foreign matter (glass pieces or molybdenum pieces) mixed in the sealed chamber portion 12 is 0.125 × 10 ⁻⁶ cm ³ or less.

  Next, the manufacturing process of the mercury-free arc tube shown in FIG. 1 will be described with reference to FIG.

First, a glass tube W having a spherical bulge portion w ₂ formed in the middle of the linear extension portion w ₁ is manufactured in advance. 2A, the glass tube W is held vertically, the electrode assembly A is inserted and held at a predetermined position from the opening end side below the glass tube W, and the glass tube W A forming gas (argon gas) supply nozzle 40 is inserted into the upper opening end of the. Further, the lower end portion of the glass tube W is inserted into the gas supply pipe 30.

  The forming gas supplied from the nozzle 40 is used to keep the inside of the glass tube W at the time of pinch sealing in a residual pressure state and prevent the electrode assembly A from being oxidized. The inert gas (argon gas or nitrogen gas) supplied from the gas supply pipe 50 holds the lead wire 8 in an inert gas atmosphere at the time of pinch sealing and while the lead wire 8 after pinch sealing is in a high temperature state. Thus, oxidation of the lead wire 8 is prevented. Reference numeral 22 denotes a glass tube gripping member.

Then, as shown in FIG. 2A, while forming gas is supplied from the nozzle 40 into the glass tube W, and further, inert gas is supplied from the pipe 50 to the lower end of the glass tube W, the linear shape is obtained. A position near the spherical bulging portion w ₂ (position including the molybdenum foil) in the extending portion w ₁ is heated to 2100 ° C. by the burner 24a, and the lead wire 8 connection side of the molybdenum foil 7 is temporarily pinched with the pincher 26a.

Next, when the temporary pinch seal is finished, as shown in FIG. 2 (b), the inside of the glass tube W is maintained at a vacuum (pressure of 400 Torr or less) by a vacuum pump (not shown), and the pincher 26b is used for molybdenum. The unpinch seal portion including the foil 7 is heated to 2100 ° C. by the burner 24b to perform the main pinch seal (primary pinch seal process). The degree of vacuum applied to the glass tube W is preferably 400 Torr to 4 × 10 ⁻³ Torr. Also in this pinch sealing process, it is desirable to prevent oxidation of the lead wire 8 by maintaining the lower opening of the glass tube W in an inert gas (argon gas or nitrogen gas) atmosphere.

  Next, as shown in FIG. 2 (c), the upper opening of the glass tube W subjected to the primary pinch seal treatment is directed downward, and the electrode bar 6, the molybdenum foil 7 and the lead wire 8 are connected and integrated. The second electrode assembly A ′ thus made is inserted into the glass tube W from a lower open end of the glass tube W to a predetermined position (second electrode assembly insertion step).

The lead wire 8 of the second electrode assembly A ′ is provided with an M-shaped bent portion 8a (see FIG. 10) in the middle in the longitudinal direction, and the bent portion 8a is formed on the inner peripheral surface of the glass tube W. The electrode assembly A ′ is self-held at a predetermined position in the longitudinal direction of the linear extending portion w ₁ in the form of pressure contact. In the second electrode assembly insertion step, the glass tube W is moved from the upper side to the lower side with respect to the fixed lower second electrode assembly A ′, and the second electrode assembly is moved to a predetermined position in the glass tube W. A ′ may be inserted, or both the second electrode assembly A ′ and the glass tube W may be moved in the approaching direction so that the second electrode assembly A ′ is inserted to a predetermined position in the glass tube W. Good.

In the step of inserting the second electrode assembly A ′, since the electrode assembly A ′ is inserted upward from the opening end of the glass tube W facing downward, the bent portion 8a of the lead wire 8 and the glass tube W rub against each other. Even if the glass piece or the molybdenum piece is scraped off, it falls inside the glass tube W by its own weight and is naturally discharged out of the glass tube W from the opening end. That is, as in the conventional method, a glass piece or molybdenum piece scraped by rubbing between the bent portion 8a of the lead wire 8 and the glass tube W remains in the spherical bulge portion w ₂ (see FIG. 9D). ), Never.

Next, after the second electrode assembly insertion step shown in FIG. 2 (c), as shown in FIG. 2 (d), below the glass tube W in which the second electrode assembly A ′ is inserted and held at a predetermined position. The opening (the opening end side of the glass tube W into which the second electrode assembly A ′ is inserted) is directed upward, and the metal halide is introduced from the opening end side above the glass tube W to the spherical bulging portion w _2. Pellet (spherical material having an outer diameter of about 0.5 mm) P is charged (filled material supply step).

  In the filling material supply step, the opening end of the glass tube W facing downward in the step of inserting the second electrode assembly A ′ is directed upward, but the second electrode assembly A ′ is located in the glass tube W. Therefore, the second electrode assembly A ′ does not move inside the glass tube without permission.

In addition, in the enclosure supply process, as shown in FIG. 3, pellets P of the planned inclusion (metal halide) are sufficiently around the second electrode assembly A ′ in the glass tube W (inner diameter 2 mm). Since there is a gap that can pass through, the pellet P of the material to be encapsulated (metal halide) introduced from the open end above the glass tube W is not obstructed by A ′ in the second electrode assembly. the inner and free fall, reaching into the spherically swollen portion w _2.

Then, after adjusting the insertion position of the second electrode assembly A ′ (in general, about several mm), the inside of the glass tube W is evacuated, and as shown in FIG. While supplying the xenon gas, a predetermined portion above the glass tube W is chipped off, whereby the electrode assembly A ′ with lead wire is temporarily fixed in the glass tube W, and a luminescent substance or the like is sealed. A symbol W ₃ indicates a chip-off part.

  It should be noted that when the electrode assembly A ′ is temporarily fixed, adjustment is performed to slightly move the insertion position of the second electrode assembly A ′. The movement amount of the second electrode assembly A ′ is generally about several mm. Therefore, when adjusting the movement of the second electrode assembly A ′, there is almost no possibility that the bent portion 8a of the lead wire and the glass tube W are scraped and scraped.

After the electrode assembly A ′ temporary fixing step shown in FIG. 2 (e), as shown in FIG. 2 (f), the spherical bulging portion w ₂ is placed in liquid nitrogen (LN ₂ ) so that the metal halide is not vaporized.
), The position near the spherical bulging portion w ₂ (the position including the molybdenum foil 7) in the linear extending portion w ₁ is heated to 2100 ° C. with the burner 24, and the secondary pinch seal is performed with the pincher 26 c. , Spherical bulge w ₂
Is sealed (secondary pinch sealing step), so that the chipless sealed chamber portion 12 in which the electrodes 6 and 6 are provided between the primary pinch seal portion 13A and the secondary pinch seal portion 13A ′ and the metal halide or the like is enclosed is sealed. A glass tube formed with is completed.

During this secondary pinch sealing process, foreign matters (glass pieces and molybdenum pieces) are not present in the spherical bulge portion w ₂ , so foreign matters (glass pieces and molybdenum pieces) are enclosed in the sealed chamber portion 12. There is no. Further, even if foreign matter (glass piece or molybdenum piece) is present in the sealed chamber during the secondary pinch sealing process, it is very small (0.125 × 10 ⁻⁶ cm ³ or less), so flicker There is no concern about the occurrence of light flux or the reduction in luminous flux maintenance factor.

  Finally, the mercury tube 10 shown in FIG. 1 is obtained by cutting the end of the glass tube W by a predetermined length.

  FIG. 6 shows the result of foreign matter mixing in the sealed chamber portion of the arc tube manufactured by the process shown in FIG. 2 and the arc tube manufactured by the conventional method, and the defective product occurrence rate by the conventional manufacturing method is 34%. On the other hand, the defective product incidence by the manufacturing method of this example was 0%.

It is a longitudinal cross-sectional view of the arc tube for discharge lamp apparatuses which is one Example of this invention. It is an explanatory view of the manufacturing process of the arc tube, (a) is an explanatory view of the temporary pinch sealing process in the primary pinch sealing process, (b) is an explanatory view of the main pinch sealing process in the primary pinch sealing process, (c) is the second An explanatory view of an electrode assembly insertion process, (d) is an explanatory view of an encapsulated material (metal halide) supply process, (e) is an explanatory view of a tip-off process, and (f) is an explanatory view of a secondary pinch sealing process. is there. It is sectional drawing which shows the clearance gap around the 2nd electrode assembly inserted in the glass tube (sectional drawing in alignment with line III-III shown in FIG.2 (d)). It is a figure which shows the relationship between the mixing amount of a foreign material, and a flicker incidence. It is a figure which shows the relationship between the mixing amount of a foreign material, and a luminous flux maintenance factor. It is a figure which compares and shows the mixing state of the foreign material in the sealed chamber part of the arc tube each manufactured by the present Example method and the conventional method. It is a longitudinal cross-sectional view of the conventional discharge lamp apparatus. It is a longitudinal cross-sectional view of the conventional mercury free arc tube. It is manufacturing process explanatory drawing of the conventional mercury free arc tube. It is a side view of the 2nd electrode assembly.

Explanation of symbols

A Electrode assembly on the primary pinch seal side A 'Electrode assembly on the secondary pinch seal side 6 Electrode bar 7 Molybdenum foil 8 Lead wire 8a M-shaped bent portion of the lead wire P Pellet (metal halide) pellet W Glass tube w ₁ Straight extension part of glass tube w ₂ Spherical bulge part of glass tube 10 Mercury free arc tube 12 Sealed chamber part 13A Primary pinch seal part 13A 'Secondary pinch seal part

Claims (2)

A primary pinch which inserts a first electrode assembly in which an electrode rod and a molybdenum lead wire are connected and integrated via a molybdenum foil from one end side of the glass tube, and pinch-seals the first electrode assembly insertion site in the glass tube. Sealing process;
An enclosure supply step of supplying a predetermined pellet-shaped encapsulation target made of a metal halide into the glass tube from the other end side of the glass tube opening;
Connect the electrode rod and the molybdenum lead wire through a molybdenum foil and integrate the second electrode assembly in which the bent portion having a width larger than the inner diameter of the glass tube is formed on the lead wire, and open the other end side of the glass tube. A second electrode assembly insertion step of inserting the first electrode assembly and holding it in a predetermined position in the glass tube;
A secondary pinch sealing step for pinch sealing the second electrode assembly insertion site in the glass tube;
A method for producing a mercury-free arc tube for a discharge lamp device comprising:
After the primary pinch sealing step, before the inclusion supply step, the electrode assembly insertion step of inserting the second electrode assembly from the other end side of the glass tube opened downward is performed. Of producing a mercury-free arc tube for a discharge lamp apparatus. A mercury-free arc tube for a discharge lamp device, which is manufactured by the method according to claim 1 and has a sealed chamber portion in which a metal rod is sealed and an electrode rod is provided in the center of the glass tube, A mercury-free arc tube for a discharge lamp device, wherein the amount of foreign matter in the sealed chamber portion of the tube is 0.125 × 10 ⁻⁶ cm ³ or less.

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