JP2015065128A - Short arc type discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure that improves operation efficiency by simplifying the operation of fitting together an electrode core wire holder and an electrode core wire, which are disposed in a sealing pipe, in a short arc type discharge lamp having an arc tube, the sealing tube, and a pair of electrodes arranged opposite within the arc tube, and hence the operation of assembling an electrode structure body, and also that enables the accurate matching of the relative positions of the counter electrodes and hence early evaporation of mercury after lighting.SOLUTION: An electrode structure 10 including an electrode is sealed in a sealing tube 3. The electrode structure body comprises: an electrode; an electrode core wire; an electrode core wire holder 12 made of metal; a sealing glass body behind the electrode core wire holder; a rear collector plate at the trailing end of the sealing glass body; a conductive foil connected to the electrode core wire holder and the rear collector plate; a cushioning foil wound round the electrode core wire holder; and a sub-sealing tube 19 for sealing the electrode core wire holder, sealing glass body, and rear collector plate. The sub-sealing tube is sealed by the sealing tube.

Description

  The present invention relates to a short arc type discharge lamp, and more particularly to a short arc type discharge lamp in which an electrode core wire holder is used in a sealed tube.

2. Description of the Related Art Conventionally, a short arc type discharge lamp enclosing mercury has been widely used as an ultraviolet light source of an exposure apparatus used to expose a semiconductor substrate or a liquid crystal substrate for a liquid crystal display.
In this type of short arc type discharge lamp, there is a glass cylindrical electrode core wire holding body for holding an electrode core wire in a sealed tube as disclosed in JP 2007-115498 A (cited document 1). A structure is used that holds the electrodes that are arranged and are enlarged.

FIG. 6 shows such a conventional short arc type discharge lamp.
As shown in FIG. 6, the short arc type discharge lamp 31 is connected in a row so as to extend outward from both ends of the arc tube 32, and the arc tube 32 made of quartz glass surrounding the light emitting space S. It is comprised by the sealing tube 33.
An anode 34 and a cathode 35 are disposed in the arc tube 32 so as to face each other, and each of them has a cylindrical shape extending from the sealing tube 33 to the arc tube 32 along the tube axis, for example, made of tungsten. The electrode core wires 36 and 36 are fixed and supported at the tip ends. The arc tube 32 is filled with a noble gas such as xenon, argon, krypton or a mixture gas thereof and a luminescent substance such as mercury.

In the sealing tube 33, a cylindrical electrode core wire holding body 37 made of quartz glass is disposed at a position close to the arc tube 32, and the electrode core wire 36 includes the cylindrical electrode core wire holding body 37. It is supported through.
Further, a sealing glass body 38 made of quartz glass is disposed behind the electrode core wire holding body 37.
A metal front current collecting plate 42 is provided on the front end face of the sealing glass body 38 so as to be sandwiched between the electrode core wire holding body 37.

The electrode core wire 36 to which the electrodes 34 and 35 are attached penetrates the electrode core wire holder 37, and the front current collecting plate 42 is fixed to the rear end portion side thereof.
On the other hand, the sealing glass body 38 is formed with a bottomed hole 38a extending from the front end surface along the axial direction and a bottomed hole 38b extending from the rear end surface, and these bottomed holes 38a, 38b are formed. In each, an electrode core wire 36 and an external lead 39 are inserted. The external lead 39 extends behind the sealing portion 33.
A rear current collecting plate 43 is disposed on the rear end surface of the sealing glass body 38, and the external lead 39 passes through the rear current collecting plate 43, and the rear current collecting plate 43 is connected to the external lead 39. It is fixed to.

A plurality of strip-shaped metal foils 41 made of molybdenum are arranged on the outer peripheral surface of the sealing glass body 38 so as to be separated from each other in the circumferential direction of the sealing glass body 38 and extend in the longitudinal direction. The inner end of each of the metal foils 41 is connected to the front current collecting plate 42 and electrically connected to the electrode core wire 36, while the outer end of each of the metal foils 41 is It is connected to the rear current collecting plate 43 and is electrically connected to the external lead 39.
Thereby, the electrode core wire 36 and the external lead 39 are electrically connected via the front current collecting plate 42, the metal foil 41 and the rear current collecting plate 43.
The outer peripheral surface of the sealing glass body 38 is air-tightly welded to the inner surface of the sealing portion 33 via the metal foil 41.
An external lead holding body 40 is disposed behind the rear current collecting plate 43, and the external lead 39 is inserted and supported by the external lead holding body 40. Is hermetically welded to the inner surface of the sealing portion 33.

  In such a conventional technique, the cylindrical electrode core wire holding body 37 that holds the electrode core wire 36 is made of quartz glass, and the electrode core wire 36 penetrates the inside thereof. When sealing with the sealing tube 33, The sealing tube 33 and the electrode core wire holder 37 are welded together.

JP 2007-115498 A

In the above prior art, the glass electrode core holder has a poor processing accuracy in the first place due to the nature of the material of quartz glass, and when the metal electrode core is passed through the glass holder, Inevitable gaps occur. Moreover, the gap is not constant in the axial direction.
As a result, positional displacement may occur between the electrode core holder and the electrode core wire, the position of the electrode becomes unstable, and positional displacement occurs at the tip between the opposing electrodes, ensuring an accurate opposing position. However, the distance between the electrodes is not stable and varies depending on the individual lamps, and the desired performance cannot be obtained.

Furthermore, in the assembly work of the glass electrode core holder and the electrode core wire, it must be performed while correcting the mismatch in dimensional accuracy between the two, and a great deal of labor is required. This hinders automation.
In addition, there is a problem that a complicated operation is involved in which a buffer foil is wound around the electrode core wire and inserted into the electrode core wire holder so that the glass electrode core wire holder and the electrode core wire are not fused.
Moreover, the tip of the electrode core holder is exposed to the light emitting space, and since it is made of glass, the temperature does not rise easily when the lamp is turned on, and the mercury that has condensed and stayed there when the lamp is turned off evaporates. There is also a problem that it is difficult to light up early.

  In view of the above-mentioned problems of the prior art, the problem to be solved by the present invention is a glass arc tube that constitutes a light emitting space, a glass sealing tube connected to both ends of the arc tube, In a short arc type discharge lamp provided with a pair of electrodes opposed to each other in the arc tube, the assembly work of the electrode core wire holding body and the electrode core wire disposed in the sealing tube, and the assembly work of the electrode structure body, is simplified. To improve the working efficiency, accurately align the relative position of the counter electrode, and provide a short arc discharge lamp structure that allows mercury to evaporate early after lighting. is there.

In order to solve the above problems, in the short arc type discharge lamp according to the present invention, an electrode structure including an electrode is sealed in a sealing tube, and the electrode structure is disposed in the electrode, the electrode core wire, and the arc tube. A metal electrode core wire holder that is exposed and has a current collecting function, a sealing glass body behind the electrode core wire holder, a rear current collecting plate at the rear end of the sealing glass body, and the electrode Conductive foil connected to the core wire holder and the rear current collector, buffer foil wound around the outer periphery of the electrode core wire holder, the electrode core wire holder, the sealing glass body, and the rear current collector It comprises a sub sealing tube that seals a plate, and the sub sealing tube is sealed by the sealing tube.
The buffer foil is embossed to have an uneven shape, and a gap is formed by the unevenness of the buffer foil between the inner peripheral surface of the sub-sealing tube and the outer peripheral surface of the electrode core wire holder. It is characterized by being.

According to the present invention, since the electrode core wire holder is made of metal, the processing accuracy is dramatically improved compared to that made of glass, and the assembly work with the electrode core wire made of the same metal is very much performed. As a result, the assembly work can be automated, and the counter electrodes can be accurately aligned with each other.
Further, since heat transfer from the electrode core wire is good and the temperature rises quickly at the time of lighting as compared with the case where the electrode core wire holder is made of glass, early mercury evaporation can be realized, and early stable lighting is brought about.
In addition, since the electrode structure including the metal electrode core wire holder is configured, the electrode structure may be sealed in the sealing tube, and automation of the lamp assembly operation is promoted, and the work efficiency is further improved. Figured.
Moreover, since the buffer foil which is embossed and has uneven | corrugated shape was wound around the outer periphery of the metal electrode core wire holder in the electrode structure, the sub seal tube was heated and melted to seal the electrode core wire holder. However, the secondary sealing tube and the electrode core wire holder are not fused, and even if the metal electrode core wire holder is thermally expanded, it is absorbed by the unevenness of the buffer foil. There will be no accidents such as damage or rupture.

Sectional drawing of the state before sealing of the Example of this invention Sectional drawing of the state after sealing of the Example of this invention Cross-sectional view of only the electrode structure of the present invention Enlarged view of part X in FIG. Enlarged view of only the buffer foil in FIG. Overall view of a conventional short arc type discharge lamp

FIG. 1 is a sectional view showing a state before sealing of a short arc type discharge lamp 1 according to the present invention, and FIG. 2 is a sectional view showing a state after sealing.
The short arc type discharge lamp 1 has an arc tube 2 and a sealing tube 3, and a pair of an anode 4 and a cathode 5 are disposed facing each other in an emission space in the arc tube 2.
In the short arc type discharge lamp of the present invention, the electrode structure 10 including the electrodes 4 and 5 is formed, and the electrode structure 10 is sealed in the sealing tube 3.
3 to 5 show details of the electrode structure 10, and FIG. 3 shows the electrode structure 10 including the anode 4. The electrode structure 10 including the other cathode 5 has a similar structure.

Hereinafter, in this specification, the front end and the front mean the light emission space side in the arc tube 2, and the rear end and the rear mean the opposite side, that is, the outside of the lamp.
The electrode core wire 11 of the electrode (anode) 4 is fitted with a metal cylindrical electrode core wire holder 12 on the rear end side. In other words, the electrode core wire 11 penetrates the cylindrical electrode core wire holder 12. These two parts are fixed to each other by brazing, caulking or the like.
A sealing glass body 13 is disposed behind the electrode core holder 12, and a ring-shaped metal rear current collecting plate 15 is disposed at the rear end thereof, and an external lead 14 is connected to the rear current collecting plate 15. And the front is in contact with the sealing glass plate 13.
The rear current collecting plate 15 and the external lead 14 are fixed by means such as brazing and caulking.
In addition, an external lead holding cylinder 16 is provided behind the rear current collecting plate 15 as necessary.
The electrode core wire 11 and the external lead 14 have a structure in which bottomed holes are formed at the front and rear ends of the sealing glass body 13 and the respective end portions are inserted as shown in FIG. It is good.

The metal electrode core wire holder 12 also has a current collecting function, and a plurality of the electrode core wire holders 12 are provided between the electrode core wire holder 12 and the rear current collector plate 15 along the outer periphery of the sealing glass body 13. The conductive foil 17 is provided. The conductive foil 17 is welded to the electrode core wire holder 12 at the front end and is welded to the rear current collecting plate 15 at the rear end.
As shown in detail in FIG. 3, a buffer foil 18 is wound around the outer periphery of the electrode core wire holder 12. The buffer foil 18 is wound around the outer circumference of the electrode core wire holder 12 one or more times, and is fixed to the electrode core wire holder 12 by welding at the overlapping portion.
At this time, as shown in FIG. 4, the buffer foil 18 is wound around the electrode core wire holder 12 from above the conductive foil 17. As shown in FIG. 5, the buffer foil 18 is provided with irregularities 18a and 18b by embossing.
Due to the irregularities 18 a and 18 b of the buffer foil 18, a gap is formed between the inner peripheral surface of the sub-sealing tube 19 and the outer peripheral surface of the electrode core wire holder 12.

Then, as shown in FIG. 3, an auxiliary sealing tube 19 made of quartz glass including an electrode core wire holder 12, a sealing glass body 13, a rear current collector 15, and an external lead holder 16 is covered. It is fitted, heat-melted and sealed.
At this time, since the buffer foil 18 is wound around the metal electrode core holder 12, the glass sub seal tube 19 is not welded to the electrode core holder 12, and the sub seal is formed. The accident that the pipe 19 is broken is prevented.
Further, since the buffer foil has irregularities and has a minute gap between the sub-sealing tube 17 and the metal electrode core wire holder 12, even if the electrode core wire holder 12 expands during lighting, it is absorbed into this gap. Therefore, neither the secondary sealing tube 12 nor the sealing tube 3 is damaged or broken.
In this way, the electrode 4 including the electrode core wire 11, the metal electrode core wire holding body 12, the sealing glass body 13, the rear current collecting plate 15, and the external lead holding body 16 as necessary is sub-encapsulated. The electrode structure 10 sealed by the stop tube 19 is formed.

Then, as shown in FIG. 1, this electrode structure 10 is disposed in the sealing tube 3, and the sealing tube 10 and the secondary sealing tube 19 are welded by heating and melting the sealing tube 10. As shown in FIG. 2, the short arc type discharge lamp 1 in which the electrode structure 10 is sealed in the sealing tube 3 is thus completed.
At this time, the front end face of the metal electrode core wire holding body 12 of the electrode structure 10 is disposed so as to be exposed to the light emitting space of the arc tube 2.

As described above, in the present invention, in the short arc type discharge lamp including the arc tube, the sealing tube, and the pair of electrodes disposed to face each other in the arc tube, the electrode core wire disposed in the sealing tube. Since the holding body is made of metal, an electrode structure is prepared including the electrode core wire holding body, and the secondary sealing tube of the electrode structure is welded and sealed to the sealing tube, the electrode core wire holding body The dimensional accuracy is easily and accurately obtained, the assembly work with the electrode core wire is simplified, and the electrode structure including this makes it possible to automatically assemble the lamp. Positioning can be greatly contributed to improvement of work efficiency and reduction of work cost.
In addition, the electrode core wire holder exposed in the light emitting space is made of metal, so that heat transfer from the electrode is fast when it is turned on, the temperature rises early, and the mercury that has condensed and stays off when it is extinguished early. Evaporates to provide stable early lighting.
Further, since the buffer foil is interposed between the outer periphery of the metal electrode core wire holder and the sub-sealing tube, it is not welded to the electrode core wire holder when the sub-sealing tube is welded.
Furthermore, since this buffer foil is uneven by embossing, a gap is formed between the sub-sealing tube and the electrode core wire holder, and the metal electrode core wire holder is thermally expanded during lighting. However, it is not absorbed by this gap and the secondary sealing tube is not damaged.

DESCRIPTION OF SYMBOLS 1 Short arc type discharge lamp 2 Light emitting tube 3 Sealing tube 4 Anode 5 Cathode 10 Electrode structure 11 Electrode core wire 12 Metal electrode core wire holding body 13 Glass body for sealing 14 External lead 15 Back current collecting plate 17 Conductive foil 18 Buffer Foil 19 Sub sealing tube

Claims (2)

A short arc type discharge lamp comprising: a glass arc tube constituting a light emitting space; a glass sealing tube connected to both ends of the arc tube; and a pair of electrodes disposed opposite to each other in the arc tube. In
An electrode structure including the electrode is sealed in the sealing tube,
The electrode structure is
Electrodes,
An electrode core wire;
A metal electrode core wire holder exposed in the arc tube and having a current collecting function;
A sealing glass body behind the electrode core holder;
A rear current collecting plate at the rear end of the sealing glass body;
A conductive foil connected to the electrode core wire holder and the rear current collector;
A buffer foil wound around the outer periphery of the electrode core holder;
The electrode core wire holder, the sealing glass body, and a sub-sealing tube that seals the rear current collector plate,
The short arc type discharge lamp, wherein the sub sealing tube is sealed by the sealing tube. The buffer foil is embossed and has an uneven shape,
2. The short arc type discharge lamp according to claim 1, wherein a gap is formed between the inner peripheral surface of the sub-sealing tube and the outer peripheral surface of the electrode core holder by the irregularities of the buffer foil. .

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