JP2002110044A - Manufacturing method of discharge tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a discharge tube allowing the exhausting and rare-gas sealing work of the discharge tube to be performed in a short time. SOLUTION: According to this manufacturing method of a discharge tube, a glass tube and first and second main electrodes are placed in a bell jar 1. A gap is provided between one open end of the glass tube 4 and the electrode 5, and another gap between the other open end thereof and the electrode 6. The interior of the glass tube is exhausted and the rare gas is sealed therein via the gaps. Thus, the interior of the glass tube can be exhausted and the rare gas can be sealed therein in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a discharge tube used as an artificial light source incorporated in a photographic camera or an electronic flash device for photographing. About the method.

[0002]

2. Description of the Related Art In the above-described discharge tube, a method as shown in FIG. 3 is often used to exhaust the inside of a glass bulb and fill a rare gas therein. In the figure, 1 is a bell jar, 2 is a base on which the glass bulb 15 and the main electrode 17 are placed, 3 is a jig for holding the bulb, 12 is a heating element, 13 is a bell jar 1 and a vacuum pump (not shown), a rare gas supply device. 14 is a cock for operating the exhaust and rare gas supply, 15 is a one-side sealed glass bulb in which the inside is exhausted and the rare gas is sealed, and 16 is sealed at one end of the glass bulb. The electrode 17 is another electrode mounted on the base 2.

In this set state, the exhaust and rare gas charging will be described. First, the cock 14 is opened and the inside of the bell jar 1 is exhausted by a vacuum pump (not shown).
Is closed, and then the cock 14 is opened again to supply a rare gas such as xenon at a predetermined pressure into the bell jar 1 by a rare gas supply device (not shown). Thereafter, the cock 14 is closed and the heating element 12 is heated by the high-frequency coil from the outside of the bell jar 1 to heat the end portion of the unsealed glass bulb 15 and the bead glass without the figure of the electrode 17. The electrode 17 is melted and sealed in the glass bulb 15 to complete the process.

[0004]

According to the above-described method, the electrode 16 is sealed on one side of the bulb 15, and the exhaust gas is filled with the rare gas through the gap between the bulb 15 and the electrode 17. The gap between the bulb 15 and the electrode 17 is small in order to make the final sealing work smooth and without deforming the bulb, so that it takes time to exhaust the inside of the bulb, and As a matter of course, noble gas can not be charged to a predetermined pressure in a short time. This is one of the factors that do not improve production efficiency in recent discharge tubes in which ultra-fine tubes with an inner diameter of 1.0 mmφ have been put to practical use. ing.

Accordingly, the present invention has been made to solve the above-mentioned problems and to provide a method for manufacturing a discharge tube capable of exhausting a bulb and filling a rare gas in a relatively short time.

[0006]

In order to achieve the object of the present invention, a first electrode sealed to one open end of a glass bulb and having a size smaller than the inside diameter of the glass bulb is provided below the bell jar. At the other end of the glass bulb, a second electrode mounted and attached with a bead glass formed so that a second electrode sealed to the other open end of the glass bulb can be locked to the open end of the glass bulb. Place. In this set state, the inside of the glass bulb is evacuated and the rare gas is supplied through a gap between the first electrode and the inside diameter of the glass bulb and a gap between the second electrode and the end of the glass bulb opening, Since exhaust and rare gas supply are performed through both open ends of the glass bulb,
Extremely smooth exhaust and rare gas charging can be achieved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to an unsealed glass tube in a bell jar, a first main electrode sealed to both open ends of the glass tube, and a first main electrode. The second main electrode and the glass tube are placed with a gap therebetween, and the inside of the glass tube is exhausted through the gap between the first and second main electrodes and the glass tube, and a rare gas is sealed therein. Since the inside of the glass tube is evacuated and supplied with a rare gas in an unsealed state, the operation of evacuating and filling the rare gas can be performed in a short time.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a schematic view showing an embodiment of a method for manufacturing a discharge tube according to the present invention. In the figure, 1 is a glass bell jar, 2 is a base, 3 is a jig, 4 is a glass tube, 5 is a first main electrode formed by attaching bead glass to a metal electrode,
Reference numeral 6 denotes a second main electrode formed by attaching a bead glass to a metal electrode, 11 and 12 denote heating elements for sealing the first and second main electrodes at the ends of the glass tube, and 13 denotes an exhaust vacuum (not shown). A connecting pipe 14 connected to the pump and the rare gas supply device is a cock for performing an exhaust operation and a rare gas supply operation.

The first main electrode 5 sealed in the glass tube 4 is a known one, and its configuration is not described, but the second main electrode 6 is a one devised for this manufacturing method. The feature is that the bead glass 10 attached to the metal body 9 is formed into a structure that can be engaged with the open end of the glass tube 4. In this embodiment, the bead glass 10 is Is slightly larger than the outer diameter of the glass tube 4 and is mounted on the open end of the glass tube 4. The unevenness of the open end surface of the glass tube 4 and the unevenness of the surface of the bead glass 10 cause the opening of the glass tube 4. There is a considerable gap between the edge and the bead glass.

In the set state, as described above, when the cock 14 is first opened and the inside of the bell jar 1 is evacuated by a vacuum pump (not shown), the inside of the glass tube 4 has both open ends, the first main electrode 5, and the second main electrode 5. The gas is exhausted through the gap between the electrodes 6, and then the cock 14 is closed and the cock 14 is opened again to supply a rare gas into the bell jar 1 from the rare gas filling device. The rare gas is sealed in the glass tube 4 through the gap between the main electrodes.

After the rare gas is sealed, the heating elements 11 and 12 are heated from the outside of the bell jar 1 by a high-frequency coil (not shown), so that both open ends of the glass tube 4 and the first main electrode 2
The bead glasses 8 and 10 of the main electrode are melted, and the electrodes 5 and 6 are sealed at both open ends of the glass tube 4.

FIG. 2 is a cross-sectional view of a discharge tube completed based on such a manufacturing method. The sealing portion at the opening end of the glass tube in which the second main electrode 6 is sealed is the first main electrode 5. Is slightly larger than the sealed portion at the sealed open end.

As described above, since the exhaust and rare gas filling of the present invention is performed through both open ends of the glass tube, it can be performed very smoothly and within a short time.

In this embodiment, as the second main electrode, the bead glass 10 having a diameter larger than the outer diameter of the glass tube 4 is used. The electrode may be held in the glass tube 4 by being formed into a shape that can be locked at the open end.

[0016]

As described above, in the method of manufacturing a discharge tube according to the present invention, since the exhaustion of the glass tube and the filling of the rare gas are performed through the gap between the two open ends of the glass tube and the sealed electrodes, The time can be greatly reduced as compared with the exhaustion of a glass tube sealed on one side and the filling of a rare gas, the operation can be performed in a very short time, and the work efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a method for manufacturing a discharge tube according to the present invention.

FIG. 2 is a completed sectional view of a discharge tube manufactured by the manufacturing method according to the embodiment of FIG. 1;

FIG. 3 is a schematic view showing a conventional method for manufacturing a discharge tube.

[Explanation of symbols]

 Reference Signs List 1 bell jar 2 base 3 jig 4 glass tube 5 first main electrode 6 second main electrode 10 bead glass

Claims (1)

[Claims] 1. A glass tube and a first main electrode sealed at one open end of the glass tube are mounted on a base in a bell jar to which a coupling tube for exhausting and filling a rare gas is connected, A second main electrode to which bead glass having a shape that can be locked above the other open end of the glass tube is mounted at the open end, and the inside of the bell jar is exhausted by an exhaust device connected to the coupling tube. Then, the inside of the glass tube is evacuated through a gap between the glass tube and the first and second main electrodes, and a rare gas is supplied into the bell jar by a rare gas filling device connected to the coupling tube. Thereby, the rare gas is supplied into the glass tube through a gap between the glass tube, the first main electrode, and the second main electrode.
A method for manufacturing a discharge tube, wherein the main electrode is sealed at the open end of the glass tube.