TWI451470B - Sealing structure of short-arc discharge lamp - Google Patents

Description

Seal structure of short arc discharge lamp Field of invention

The present invention relates to a seal portion structure of a short arc discharge type lamp, and more particularly to a structure in a sealed tube of a short arc type discharge lamp used in the field of semiconductor or liquid crystal manufacturing.

Background of the invention

In order to improve the production efficiency in the manufacturing field of semiconductors or liquid crystals, the development of short-discharge discharge lamps has been greatly increased. Therefore, when manufacturing a lamp, there is a problem that a great stress is applied to the metal foil, and the sealing portion is broken. The countermeasure is to make the sealing portion effective in a double seal structure. In the double seal structure, since the metal foil is not subjected to a great stress when the lamp is manufactured, the drawback of the metal foil crack can be solved. Moreover, even if the electrode is large and heavy, the part can be welded to the sealing tube correctly, and the mechanical strength of the sealing portion is improved, thereby reducing the risk of breakage during manufacture or transportation. Hereinafter, a conventional technique of a double seal structure of a short arc type discharge lamp will be described.

A short arc type discharge lamp of the conventional double seal structure proposed by the applicant in the patent document 1 will be described with reference to Figs. 7 and 8. Fig. 7 is a cross-sectional view of a short arc type discharge lamp of a conventional double seal structure. As shown in Fig. 7, there is an arc tube 1 which forms a discharge space. a pair of electrodes (anode 2, cathode 3) The light is disposed in the arc tube 1 . The discharge space S is sealed with mercury and a rare gas to generate a space for discharge. The head-thick inner glass tube 236 is an inner glass tube that expands the outer diameter on the side of the discharge space.

Figure 8 is a cross-sectional view of the sealing portion of the short arc type discharge lamp. In Fig. 8, the electrode support rod 4 supports the metal member of the anode. The guide bar 5 is a conductive member for supplying electric power. The outer sealing tube 11 is an elongated cylindrical portion of the arc tube. The inner seal tube 12 is an inner seal tube that is sealed to be an airtight cylindrical glass member and has a larger outer diameter than the outer inner seal tube. The outer sealing tube 13 is for sealing an airtight cylindrical glass member, and is an inner sealing tube having an outer diameter smaller than that of the inner inner sealing tube. The glass rod 18 is a glass member that structurally connects the guide bar 5 and the electrode support rod 4. The head-thick internal glass tube 236 is an internal glass tube whose outer diameter is enlarged on the discharge space side, and is a member that holds the electrode support rod 4. The small diameter portion 237 is a small portion of the small inner glass tube. The large diameter portion of the 238 is a large part of the large internal glass tube.

The inclined portion 239 is a portion between the large diameter portion and the small diameter portion of the thick inner glass tube. The outer glass tube 7 holds the glass member of the guide bar 5. The metal foil 8 is a metal member that is connected between the glass rod 18 and the outer sealing tube 13 and electrically connects the inner metal ring to the outer metal ring. The fixing ring 9 is a quartz member that suppresses the movement of the outer sealing tube 13 in the axial direction. The inner metal ring 14 is a metal member that electrically connects the electrode support rod 4 and the metal foil 8. The outer metal ring 15 is a metal member that electrically connects the guide bar 5 and the metal foil 8. The welded end portion 224 is a circumferential end of the discharge space side of the welded portion of the thick inner glass tube and the outer sealed tube end. The diameter of the welded end of the discharge space side of the thick inner glass tube of the welded end diameter D1 is the diameter of the welded end.

The inner sealed tube 12 is present in the vicinity of the inclined portion 239 which is connected to the outer side of the light-emitting tube 1 and to the vicinity of the inclined portion 239 of the inner glass tube 236. The inner sealed tube 12 is not exposed to the discharge space S. Therefore, it is less common in the occurrence of cracks than in the conventional double seal structure, the reliability is improved, and the inspection time of the welded state can be shortened.

As described above, in the conventional double seal structure, the seal portion of the short arc type discharge lamp is configured to use a thick inner glass tube having a small diameter portion and a large diameter portion to constitute a mounting member, and the discharge space side of the inner seal tube is formed. The end portion is aligned between the small diameter portion and the large diameter portion of the thick inner glass tube, and the inner tube and the outer sealing tube are thickly welded, and the end portion of the inner sealing tube on the discharge space side is not exposed to the discharge space. The reliability and manufacturing efficiency of the double seal structure can be improved.

Further, in order to shorten the rise time when the short arc type discharge lamp is turned on, it is working to reduce the heat capacity of the sealing portion. The "short arc type mercury lamp" disclosed in Patent Document 2 is a large mercury lamp having a good rising characteristic. The pair of electrodes are disposed to face each other, and a light-emitting portion of mercury and a rare gas and a sealing portion formed at both ends thereof are sealed. The light-emitting portion is constituted by a main light-emitting space portion and a root space portion formed on the seal portion side of the main light-emitting space portion, and the ratio of the internal volume of the main light-emitting space portion to the internal volume of the root space portion is 0.01 to 0.09.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-157513

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2007-128755

Invention

However, in the conventional double seal structure, there is a problem that the thermal stress concentrates on the seal portion, the problem of easy breakage, and the rise time until stable brightness is increased.

The reason why the stress concentrates on the sealing portion and is broken is as follows. The short arc type discharge lamp determines the outer diameter of the inner metal ring based on the number of metal foils corresponding to the lamp current. Since the conventional double seal structure is provided with a large diameter portion on the discharge space side of the thick inner glass tube, the welded end diameter D1 exposed to the discharge space is larger than that of the conventional one heavy seal structure. When the welding end diameter D1 is increased, since the stress concentrates on the welded end portion 224, minute cracks are generated, so that the starting point of the cracking when the lamp is turned on may occur.

The reason for the increase in time until steady lighting is as follows. The time (rise time) of the short arc type discharge lamp from the start of discharge to the rise of the rated lamp voltage called the steady lighting state should be short. In the conventional double seal structure, since the large-diameter portion is formed on the discharge space side of the head inner glass tube, the heat capacity of the thick inner glass tube 236 at the discharge space side is larger than that of the single-tube seal structure. Therefore, the vicinity of the first thick inner glass tube 236 becomes the coldest portion, and it is difficult to heat up, and it is difficult to steam the mercury. The hair is not helpful for the discharge, so it takes time to rise to the stable discharge voltage, and it cannot be quickly transferred to the stable lighting.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, to improve the reliability of a double seal structure of a short arc type discharge lamp, and to shorten the time.

In order to solve the above problems, the present invention is a seal portion structure of a short arc type discharge lamp having a double seal structure, comprising a glass light-emitting tube, a glass outer seal tube connected to the light-emitting tube, and a welded inner side of the outer seal tube a coaxial inner sealing tube, a pair of electrodes enclosed in the arc tube, a metal electrode supporting rod supporting the electrode, an inner metal ring electrically connected to the electrode, and a guide rod for supplying electric power to the electrode and electricity An outer metal ring connected to the guide bar, a plurality of metal foils electrically connected to the inner metal ring and the outer metal ring, an outer glass tube supporting the guide bar, supporting the guide bar, the inner metal ring, and the outer metal a ring, the electrode support rod and the glass rod of the metal foil, and an inner glass tube supporting the electrode support rod; the internal glass tube has a larger diameter portion than the inner metal ring, and has a smaller diameter on the side of the light-emitting tube than the foregoing The small diameter section of the large diameter section. The large diameter portion is from a portion contacting the inner metal ring to a portion of the small diameter portion. The inner glass tube has a base diameter portion having an outer diameter approximately equal to the inner metal ring from a portion of the large diameter portion to a portion contacting the inner metal ring. The axial direction cross section of the large diameter portion is a mountain shape.

According to the above configuration, the diameter of the welded end portion of the short arc type discharge lamp having the double seal structure is as small as that of the one heavy seal structure, the stress concentration for the cause of the crack can be reduced, the reliability can be improved, and the welded end portion can be shortened. The inspection time of the welding state. Further, even if the heat capacity on the discharge space side is a double seal structure, the heat capacity can be reduced to the same extent as that of the one heavy seal structure, so that the brightness rise is accelerated. Further, even if the outer diameter of the seal portion necessary for strength is increased, the outer diameter of the ferrule is not increased, and overheating of the ferrule can be prevented. Further, since the double sealed tube can be sealed once, even if it is a double seal structure, it is a sealing step equivalent to a heavy seal, and the working time can be shortened.

The best form for implementing the invention

Hereinafter, the best mode for carrying out the invention will be described in detail with reference to Figs. 1 to 6 .

[First Embodiment]

According to a first embodiment of the present invention, a thin inner glass tube having a small diameter portion on a discharge space side is used to constitute a mounting member, and an end portion of the discharge space side of the head thin inner sealing tube is aligned with a large diameter of the thin internal glass tube. The sealing structure of the short arc type discharge lamp with the end face sealed.

Fig. 1 is a cross-sectional view showing the entire structure of a sealing portion of a short arc type discharge lamp according to a first embodiment of the present invention. In Fig. 1, the arc tube 1 is sealed with mercury. Quartz glass tube. The anode 2 is an electrode on the positive side. The cathode 3 is an electrode on the negative side. The discharge space S is sealed with mercury and a rare gas to generate a space for discharge. The head thin inner glass tube 36 is an inner glass tube having a small diameter portion on the discharge space side.

Fig. 2 is a partial cross-sectional view showing the structure of a seal portion of a short arc type discharge lamp. In Fig. 2, the electrode support rod 4 supports the metal member of the anode. The guide bar 5 is a conductive member for supplying electric power. The metal foil 8 is a metal member that is connected between the glass rod 18 and the inner glass tube 6 and electrically connects the inner metal ring to the outer metal ring. The fixing ring 9 is a quartz member that suppresses the movement of the inner sealing tube in the axial direction. The outer sealing tube 11 is an elongated cylindrical portion of the arc tube. The inner seal portion 12 is a cylindrical glass member that is sealed to be airtight, and is an inner seal tube having an outer diameter larger than that of the outer seal tube. The outer sealing tube 13 is a cylindrical glass member sealed to be airtight, and is an inner sealing tube having an outer diameter smaller than that of the inner inner sealing tube. The inner metal ring 14 is a metal member that electrically connects the electrode support rod 4 and the metal foil 8. The outer glass tube 15 is a glass member that holds the guide bar 5.

The inner end portion 16 is an end portion of the inner side sealed tube 10 on the discharge space side. The outer end portion 17 is an end portion of the inner side sealing tube 10 on the side of the fixing ring. The glass rod 18 is a glass member that structurally connects the guide bar and the electrode support rod 4. The welded end portion 24 is a cylindrical terminal end on the discharge space side of the welded portion of the thin inner glass tube and the outer sealed tube. That is, the discharge space side of the thick front inner glass tube 236 is partially flattened, and the welded end portion 24 is thin. The outer metal ring 25 is a metal member that electrically connects the guide bar to the metal foil. The head thin internal glass tube 36 is attached to The inner glass tube having a small diameter portion on the discharge space side is a member that holds the electrode support rod 4. The small-diameter portion 37 is a small portion of the small inner glass tube. The large-diameter part 38 is the part of the large internal glass tube. The large diameter portion end surface 39 is an end surface of the large diameter portion on the inner metal ring side. The inner diameter of the sealing tube D2 is the diameter of the thin inner glass tube exposed to the surface of the discharge space.

Fig. 3 is a cross-sectional view showing a state in which a mounting member of a seal portion structure of a short arc type discharge lamp is inserted into an inner sealing tube. In Fig. 3, the fixing ring 9 is an annular member for suppressing the movement of the outer sealing tube in the axial direction. The inner seal pipe 22 before welding is an inner seal pipe which is welded before the heat shrinkage diameter of a burner or the like, and has an inner diameter of the outer seal pipe which has the same inner diameter and a larger outer diameter than the outer seal pipe. The outer sealing tube 23 before welding is an outer sealing tube before welding, and is an inner sealing tube having the same inner diameter and a smaller outer diameter than the inner sealing tube. The inner end portion 26 is an end portion on the discharge space side of the inner sealed tube before welding. The outer end portion 27 is an end portion on the side opposite to the discharge space of the outer sealed tube before welding. The mounting part 19 is a mounting part that uses a thin internal glass tube.

Fig. 4 is a cross-sectional view showing a state in which a mounting member of a seal portion structure of a short arc type discharge lamp is inserted into an outer sealed tube and placed at a desired position. In Fig. 4, the outer side seal pipe 21 before welding is welded to the outer side seal pipe by a heat shrinkage diameter of a burner or the like.

A sealing portion structure and a manufacturing method of a short arc type discharge lamp according to a first embodiment of the present invention configured as above will be described. First, referring to Figure 1 and Figure 2, The overall structure of the short-arc discharge lamp. The short arc type discharge lamp has an arc tube 1 which is expanded at the center, and has a pair of anodes 2 and cathodes 3 in the arc tube 1. Further, the mounting member 19 is provided with a series of metallic components that supply electric power from the outside of the discharge lamp to the internal electrodes and that holds the glass components. Specifically, the mounting component 19 is composed of an anode 2, an electrode support rod 4, a guide bar 5, a glass rod 18, a head thin inner glass tube 36, an outer glass tube 7, a metal foil 8, an inner metal ring 14, and an outer metal ring 15. .

Next, the components will be described with reference to Fig. 3. Using the head thin inner glass tube 36, the head-mounted mounting member 19 is produced in the same manner as in the prior art. The manufactured head-mounted mounting member 19 is inserted into the inner sealing tube 22 before welding and the outer sealing tube 23 before welding, and the fixing ring 9 prevents the movement in the axial direction.

As shown in Fig. 3, the inner end portion 26 of the inner seal tube 22 before welding is brought into contact with and fixed to the large-diameter end surface 39 of the head thin inner glass tube 36. The large-diameter portion end surface 39 functions as a stopper that locks one end of the inner seal tube 22. The outer end portion 27 of the outer seal tube 23 before welding is in contact with the fixed ring 9. Therefore, the large-diameter portion end surface 39 and the fixing ring 9 can be prevented from moving in the axial direction of the inner seal pipe 22 before welding and the outer seal pipe 23 before welding.

Next, the method of arranging the components will be described with reference to Fig. 4. The mounting member 19 holding the inner sealing tube 22 and the outer sealing tube 23 is inserted into the outer sealing tube 21 before welding, and the anode 2 is placed in the discharge space. The location of the location within S. The inside of the outer sealed tube (in the discharge space) is in a negative pressure state, and is heated by a burner or the like to reduce the diameter of the outer seal tube 21, the inner seal tube 22, and the outer seal tube 23 before welding, and seal the outer seal tube 21 and the inside. The tube 22, the outer sealing tube 23, and the mounting member 19 are welded. In this way, a double seal construction seal can be performed. An example in which two types of inner sealing tubes having different outer diameters are used is used, and three or more inner sealing tubes having different outer diameters may be used depending on the required strength, and a double sealing structure having a desired strength and shape can be easily obtained.

Compared with the diameter D1 of the welded end portion on the discharge space side when the conventional thick inner glass tube shown in Fig. 7 is used, as shown in Fig. 1, when the head thin inner glass tube 36 is used, the welding can be reduced. The diameter D2 of the end portion prevents the concentration of stress on the thin inner glass tube of the head. Since the diameter of the welded end portion 24 on the discharge space side which is the same as the conventional one heavy pipe sealing structure can be used, the occurrence of cracks at the melt end portion can be reduced. Further, since the end face of the inner glass tube on the discharge space side can be made small, the temperature rise at the start of the lighting is accelerated, and the rise of the lighting is accelerated.

As described above, in the first embodiment of the present invention, the sealing portion of the short arc type discharge lamp is configured to be a thin inner glass tube having a small diameter portion on the discharge space side to constitute a mounting member for discharging the inner sealing tube. Since the space is aligned with the end surface of the large-diameter portion of the inner glass tube, the structure is sealed, so that the reliability is improved and the rise time of the lighting is shortened.

[Second embodiment]

In the second embodiment of the present invention, the intermediate thick glass tube having the large diameter portion formed in the intermediate portion is used to form the mounting member, and the end portion of the inner sealed tube on the discharge space side is aligned with the large diameter portion of the intermediate thick inner glass tube. The end surface is configured by a sealing portion of a short arc type discharge lamp in which the intermediate thick inner glass tube and the outer sealed tube are welded.

Fig. 5 is a partial cross-sectional view showing the structure of a seal portion of a short arc type discharge lamp. In Fig. 5, the inner end portion 16 is the end portion on the discharge space side of the inner seal tube 10. The outer end portion 17 is an end portion of the inner side sealing tube 10 on the side of the fixing ring. The glass rod 18 is a glass member that structurally connects the guide bar and the electrode support rod 4. The intermediate thick inner glass tube 136 holds the inner glass tube of the electrode support rod 4. The intermediate portion between the discharge space side and the inner metal ring side of the intermediate thick inner glass tube has a large-diameter portion (diameter D3) having a mountain-shaped or trapezoidal cross-sectional shape in the axial direction. The large diameter portion should be located near the center of the axis of the inner glass tube. The small diameter portion 137 is a small portion of the diameter of the inner thin glass tube. The large-diameter part 138 is the part of the large internal glass tube. The base diameter portion 140 is a portion of the middle of the thick inner glass tube which is the same diameter as the inner metal ring. In Fig. 5, since the thickness of the metal foil is drawn, the diameter of the base diameter portion appears to be larger than the diameter of the inner metal ring. Since the actual metal foil is a thin foil, the diameter of the base diameter portion and the diameter of the inner metal ring are About equal. The large diameter portion end surface 139 is an end surface of the large diameter portion on the inner metal ring side. The welded end portion 124 is a circumferential end of the discharge space side of the welded portion of the intermediate thick inner glass tube and the outer sealed tube. The description of the same portions as those of the first embodiment will be omitted.

Fig. 6 is a cross-sectional view showing a state in which a mounting member of a seal portion structure of a short arc type discharge lamp is inserted into an inner sealing tube. In Fig. 6, the fixing ring 9 is an annular member for suppressing the movement of the outer sealing tube in the axial direction. The inner seal pipe 22 before welding is an inner seal pipe before welding by a heat shrinkage diameter of a burner or the like, and is an inner seal pipe having the same inner diameter and a larger outer diameter than the outer seal pipe. The outer sealing tube 23 before welding is an outer sealing tube before welding, and the inner sealing tube having the same inner diameter and smaller outer diameter than the inner sealing tube. The inner end portion 26 is an end portion on the discharge space side of the inner sealed tube before welding. The outer end portion 27 is an end portion on the side opposite to the discharge space of the outer sealed tube before welding. The mounting part 19 is a mounting part using an intermediate thick internal glass tube.

A sealing portion structure and a manufacturing method of a short arc type discharge lamp according to a second embodiment of the present invention configured as described above will be described. Refer to Figure 6 for a description of the mounting parts. Using the intermediate thick inner glass tube 136, an intermediate thick mounting member 119 is produced in the same manner as in the prior art. The prepared intermediate thick mounting member 119 is inserted into the inner sealing tube 22 before welding and the outer sealing tube 23 before welding, and the fixing ring 9 prevents the movement in the axial direction.

As shown in Fig. 5, the inner end portion 26 of the inner seal tube 22 before welding is brought into contact with and fixed to the large-diameter end surface 139 of the intermediate thick inner glass tube 136. The large-diameter portion end surface 139 functions as a stopper that locks one end of the inner seal tube 22. The outer end portion 27 of the outer seal tube 23 before welding is in contact with the retaining ring 9. because Therefore, the large-diameter portion end surface 139 and the fixing ring 9 can be used to suppress the movement of the inner sealing tube 22 before welding and the outer sealing tube 23 before welding in the axial direction.

Similarly to the first embodiment, the intermediate thick glass tube 136 is used to reduce the diameter D2 of the welded end portion to the same extent as the conventional one-tube sealing structure. Therefore, the concentration of stress in the intermediate thick inner glass tube can be reduced, and the crack at the welded end portion can be reduced. Further, since the end surface of the intermediate thick glass tube on the discharge space side can be made small, the temperature rise at the start of the lighting is accelerated, and the rise of the lighting is accelerated.

The inner sealed tube 12 is provided between the outer side sealing tube 11 and the mounting member 119 connected to the light-emitting tube 1, and to the vicinity of the large-diameter portion end surface 139 of the intermediate thick inner glass tube 136. Therefore, in the first embodiment, the inner end surface of the inner sealing tube is welded to the end surface of the large diameter portion of the thin inner glass tube. In contrast, in the second embodiment, the inner surface of the inner sealing tube and the intermediate inner portion are formed. The circumference of the base diameter portion of the glass tube is welded outside. Therefore, compared with the first embodiment, the second embodiment can weld the inner sealed tube and the inner glass tube more reliably. Therefore, the risk of cracking due to cracks in the vicinity of the inner metal ring can be reduced, and reliability can be improved.

As described above, in the second embodiment of the present invention, the sealing portion of the short arc type discharge lamp is configured to use the small diameter portion having the discharge space side, the large diameter portion of the intermediate portion, and the base diameter portion of the inner metal ring side. The middle thick inner glass tube constitutes the mounting part, and the end of the discharge space side of the inner sealing tube is aligned with the middle The end surface of the large-diameter portion of the thick inner glass tube has a structure in which the intermediate inner glass tube and the outer sealed tube are welded together, so that the reliability of the double-sealed structure can be improved, and the rising characteristic of the lighting can be improved. Further, since the inner seal tube and the inner glass tube can be welded to each other reliably, the reliability against cracking can be improved.

Industry availability

The seal portion structure of the short arc discharge type lamp of the present invention is most suitable as a seal portion structure of a short arc type discharge lamp used in the field of semiconductor or liquid crystal production.

1‧‧‧Light tube

2‧‧‧Anode

3‧‧‧ cathode

4‧‧‧electrode support rod

5‧‧‧Guide bars

7‧‧‧External glass tube

8‧‧‧metal foil

9‧‧‧Fixed ring

11‧‧‧Outer sealing tube

12‧‧‧Internal sealed tube

13‧‧‧External sealing tube

14‧‧‧Internal metal rings

15‧‧‧External metal ring

16‧‧‧Internal end

17‧‧‧External end

18‧‧‧ glass rod

19‧‧‧Installation parts

21‧‧‧Outer sealing tube

22‧‧‧Internal sealed tube

23‧‧‧External sealing tube

24‧‧‧weld end

25‧‧‧External metal ring

26‧‧‧Internal end

27‧‧‧External end

36‧‧‧ head thin internal glass tube

37‧‧‧Little Trails Department

38‧‧‧Great Path Department

39‧‧‧ Large diameter end face

119‧‧‧ intermediate rough mounting parts

124‧‧‧welding end

136‧‧‧ Middle thick internal glass tube

137‧‧‧Little Trails Department

138‧‧‧The Great Trails Department

139‧‧‧ Large diameter end face

140‧‧‧Foundation

224‧‧‧weld end

236‧‧‧ head thin internal glass tube

237‧‧‧Little Trails Department

238‧‧‧The Great Trails Department

239‧‧‧ inclined section

D1‧‧‧weld end diameter

D2‧‧‧ Sealing tube inner diameter

D3‧‧ Path

D4‧‧ Path

S‧‧‧discharge space

Fig. 1 is a cross-sectional view showing the entire structure of a sealing portion of a short arc type discharge lamp according to a first embodiment of the present invention.

Fig. 2 is a partial cross-sectional view showing the structure of a sealing portion of a short arc type discharge lamp according to a first embodiment of the present invention.

Fig. 3 is a cross-sectional view showing the mounting member of the seal portion structure of the short arc type discharge lamp according to the first embodiment of the present invention inserted into the inner seal tube.

Fig. 4 is a cross-sectional view showing a state in which a mounting member of a seal portion structure of a short arc type discharge lamp according to a first embodiment of the present invention is inserted into an outer sealed tube and placed at a desired position.

Fig. 5 is a partial cross-sectional view showing the structure of a sealing portion of a short arc type discharge lamp according to a second embodiment of the present invention.

Fig. 6 is a cross-sectional view showing a state in which a mounting member of a seal portion structure of a short arc type discharge lamp according to a second embodiment of the present invention is inserted into an inner seal tube.

Figure 7 shows a short arc discharge lamp with a conventional double seal construction A cross-sectional view of the structure.

Fig. 8 is an enlarged cross-sectional view showing a seal portion of a short arc type discharge lamp having a conventional double seal structure.

1‧‧‧Light tube

2‧‧‧Anode

4‧‧‧electrode support rod

5‧‧‧Guide bars

8‧‧‧metal foil

9‧‧‧Fixed ring

11‧‧‧Outer sealing tube

12‧‧‧Internal sealed tube

13‧‧‧External sealing tube

14‧‧‧Internal metal rings

15‧‧‧External metal ring

16‧‧‧Internal end

17‧‧‧External end

18‧‧‧ glass rod

24‧‧‧weld end

25‧‧‧External metal ring

36‧‧‧ head thin internal glass tube

37‧‧‧Little Trails Department

38‧‧‧Great Path Department

39‧‧‧ Large diameter end face

D2‧‧‧ Sealing tube inner diameter

S‧‧‧discharge space

Claims (4)

A seal portion structure of a short arc type discharge lamp, which is a double seal structure, comprising: a glass light-emitting tube; a glass outer seal tube connected to the light-emitting tube; and an inner seal tube connected to the outer seal tube The inner side is welded into a coaxial shape; a pair of electrodes are enclosed in the light-emitting tube; a metal electrode support rod is used to support the electrode; an inner metal ring is electrically connected to the electrode; and a guide rod is used to electrically Provided to the electrode; an external metal ring electrically connected to the guide bar; a plurality of metal foils electrically connected to the inner metal ring and the outer metal ring; and an outer glass tube supporting the guide bar; a glass rod supporting the guide bar, the inner metal ring, the outer metal ring, the electrode support rod and the metal foil; and an inner glass tube supporting the electrode support rod; the inner glass tube having a diameter larger than the foregoing The large diameter portion of the inner metal ring has a small diameter portion having a smaller diameter than the large diameter portion on the side of the light-emitting tube, and is melted on the discharge space side of the inner glass tube. The inner diameter of the outer end of the sealed tube is smaller than the diameter of the large diameter portion. The seal portion structure of the short arc type discharge lamp of claim 1, wherein the end face of the large diameter portion is connected to the discharge of the inner seal tube The end of the space side is sealed. The seal portion structure of the short arc type discharge lamp of claim 1, wherein the inner glass tube has a base diameter which is approximately equal to an inner diameter of the inner metal ring at a portion from the large diameter portion to the inner metal ring. unit. The seal portion structure of the short arc type discharge lamp of claim 3, wherein the large-diameter portion has a mountain-shaped cross section in the axial direction.