JP2002075282A - Discharge lamp and its cooling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make up an ideal cooling balance without using an enormous amount of cooling gas for cooling a discharge lamp. SOLUTION: A pair of air vents 17-2, 17-4 are formed at a position opposite to each other on a periphery face of a second metal base 12-2. Then, a pair of cooling nozzles are arranged on the periphery of the second metal base 12-2 for spraying cooling gas on the second metal base 12-2. The cooling gas sprayed in A direction collides with the periphery face of the second metal base 12-2 and then rises along the periphery face of the luminous tube 2, which cools a second sealing part T and a second luminous tube S. The cooling gas sprayed in B direction enters inside the second metal base 12-2 through the air vent 17-2, cools a second junction part U, and gets out through the air vent 17-4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp for optically processing a work such as a semiconductor, a liquid crystal or a printed circuit board, and more particularly to a discharge lamp having a base having excellent crack resistance and a method of cooling the same.

[0002]

2. Description of the Related Art Conventionally, as a discharge lamp for optically processing a work such as a semiconductor, a liquid crystal or a printed circuit board, for example, there is one shown in FIG. This discharge lamp includes an arc tube 2, a cathode 3, an anode 4, a first internal lead 5, a second internal lead 6,
First bead tube 7, second bead tube 8, first quartz glass rod 9, second quartz glass rod 10, first base 11, and second base
It has twelve.

[0003] The light emitting tube 2 has a light emitting portion formed in a substantially spherical or elliptical spherical shape from quartz glass, and a pair of sealing portions formed in a tubular shape on both sides thereof. The cathode 3 and the anode 4 face each other inside the light emitting section. The first behind the cathode 3
The internal lead 5 is connected, and the second internal lead 6 is connected behind the anode 4. The first internal lead 5 is inserted into the first bead tube 7, and the rear end is inserted into the first quartz glass rod 9. Similarly, the second internal lead 6 is inserted into the second bead tube 8, and the rear end is inserted into the second quartz glass rod 10.

In the sealing portion, a first base 11 is fixed outside a portion accommodating the first quartz glass rod 9, and a first cap 11 is fixed outside a portion accommodating the second quartz glass rod 10. Two bases 12 are fixed.

FIG. 6 is a cross-sectional view showing the structure of the sealing portion on the anode side in FIG. 5 and the inside of the base. As shown in this figure, a second internal lead 6 is inserted into one end (the end on the anode side) of the second quartz glass rod 10. In addition, the other end of the second quartz glass rod 10 is inserted with the tip side of the current introducing metal 14. A power supply line 15 is connected to the rear end side of the current introducing metal 14 via a joint 16. Further, a metal foil for current introduction (not shown) is arranged on the outer peripheral surface of the second quartz glass rod 10 and is melted and adhered to the inner surface of the arc tube 2. The second base 12 is provided so as to cover the joint 16. The sealing part on the anode side has been described above, but the same applies to the structure on the cathode side.

[0006] A discharge medium made of mercury and a rare gas such as argon or xenon is sealed in the sealed arc tube 2 to constitute a high-pressure discharge lamp.

[0007] An ideal cooling balance during the operation of the discharge lamp configured as described above will be described. First, the light emitting portion is ideally at 500 to 800 ° C. in order to avoid the danger of non-evaporation of mercury at low temperatures and the risk of burst at high temperatures. The sealing portion is ideally at 400 ° C. or lower in order to prevent cracks in the sealing portion due to thermal expansion of the current introducing metal foil and peeling of the metal foil on the light emitting portion side. In addition, feeder
The joint 16 between the metal 15 and the current introducing metal 14 is formed to prevent the seal 16 from cracking due to the oxidation of the joint 16 and its surroundings and the accompanying thermal expansion of the current introducing metal 14.
It is ideally below ℃. Then, in order to create such an ideal cooling balance, a method of blowing gas (air, nitrogen gas, or the like) to a base of a discharge lamp has been generally performed.

[0008]

However, the conventional cooling method has not realized an ideal cooling balance. Hereinafter, this point will be described with reference to FIGS.

FIG. 7 is a diagram showing a case where a cooling gas is blown to a die having no air hole. (A) of this figure is a perspective view, and (b) is a horizontal cross section of a base part. FIG.
As shown in the figure, when the cooling gas is blown to the base 12 having no air hole by the cooling nozzles in the directions A and B different from each other by 90 ° in the same horizontal plane, the power supply line 15 and the metal for current introduction are formed. If the junction 16 with 14 is cooled so as to be within an appropriate temperature (100 ° C. or less), the flow rate of the cooling gas becomes enormous, the light emitting portion is excessively cooled, and the non-evaporation of mercury occurs. . The reason for this is as shown in FIG.
This is because the cooling gas that has collided with the gas flows to the arc tube 2 as shown by E1 and F1 in the figure and lowers its temperature.

As shown in FIG. 8, in the light emitting section, the first light emitting section R on the cathode side, the second light emitting section S on the anode side, the first sealing section Q on the cathode side, and the sealing section on the anode side. The part is a second sealing part T, the joining part on the cathode side is the first joining part P, the joining part on the anode side is the second joining part U, and the cooling nozzles in directions C and D differ by 90 ° in the same horizontal plane. A cooling gas is blown onto the first base 11 and the second base is cooled by the cooling nozzles in the directions A and B described above.
FIG. 9 shows measurement data of the relationship between the temperature of each part and the flow rate of the cooling gas (here, air) when the cooling gas is blown to the nozzle 12. Note that the second light emitting unit S and the second light emitting unit S in FIG.
The sealing part T and the second joint part U are respectively S,
Corresponds to T and U. That is, the second light emitting unit S and the second sealing unit T are present on the surface of the arc tube, and the second joint U is connected to the joint 16
Be yourself. The same applies to the first light emitting unit R, the first sealing unit Q, and the first joining unit P. Also, this measurement was adjusted so that an equal amount of cooling gas was injected from each nozzle,
The specifications of the discharge lamp used are as follows. Voltage: about 50 V, current: about 100 A, power: about 5 kW, light-emitting part diameter: φ82 mm, amount of mercury: about 30 mg / cc

As shown in FIG. 9, in order to reduce the temperature of the first joint P and the second joint U to 100.degree.
An enormous amount of cooling gas of about 0 liter is required. Then, in that case, it can be seen that the temperature of the second light emitting unit S drops to about 450 ° C.

On the other hand, as shown in FIG. 10, four air holes (two through holes orthogonal to each other on the same horizontal plane) 17-1 to 17-4 are formed in order to cool the joint efficiently. There is also a discharge lamp provided with the formed second base 12-1. Where air holes 17
An air hole 17-3 is provided at a position where -1 is extended straight, and an air hole 17-4 is provided at a position where air hole 17-2 is extended straight.
The line connecting the air holes 17-1 and 17-3 and the air holes
Line segments connecting 17-2 and air holes 17-4 are orthogonal to each other.

However, in the cooling method shown in FIG. 10, the cooling gas injected from the nozzle in the direction of A passes through the air holes 17-1 to 17-3 as shown in F2.
It does not turn to the light emitting part and the sealing part. Similarly, the cooling gas injected from the nozzle in the direction B passes through as in E2, and does not go to the light emitting portion and the sealing portion. For this reason, the light emitting part and the sealing part were not sufficiently cooled, resulting in a high temperature. As a result, it is inevitable that the life of the discharge lamp is shortened and the risk of rupture is increased due to the high temperature of the light emitting portion. Also,
The high temperature of the sealing portion may cause cracks in the sealing portion or peeling of the metal foil due to thermal expansion of the metal foil for current introduction.

FIG. 11 shows measurement data of the relationship between the temperature of each part during the operation of the discharge lamp shown in FIG. 10 and the flow rate of the cooling gas. Here, the relationship between the specifications of the discharge lamp and the flow rate of each nozzle is the same as when measuring the data in FIG.

As shown in FIG. 11, the first and second joints P and U are always maintained at an appropriate temperature of 100 ° C. or less, but the first and second light emitting units R and S and the In order to bring the first and second sealing portions Q and T to the appropriate temperatures, an enormous amount of cooling gas of about 250 liters per minute is required.

Further, it was confirmed from the experimental data that if the flow rate of the cooling gas is increased, the respective parts can be set to an appropriate temperature. Since there is a variation in exhaust capability, it is not always possible to secure an appropriate temperature for all discharge lamps.

The present invention has been made in view of the above problems, and a discharge lamp capable of forming an ideal cooling balance without using an enormous amount of cooling gas and a method of cooling the discharge lamp. The purpose is to provide.

[0018]

A discharge lamp according to the present invention comprises:
A light emitting tube having a light emitting part in the center and a sealing part on both sides,
A pair of current introducing metal foils disposed in the sealing portion and fused to the arc tube, a pair of joining portions for joining the current introducing metal foil and a power supply line, and the joining portion A discharge lamp including a pair of bases provided to cover and having an air hole, wherein the base propagates a part of a cooling gas supplied from the outside to the joining portion from the air holes. Another part of the cooling gas propagates from the outer peripheral surface of the base to the outer peripheral surface of the arc tube. With this configuration, when the discharge lamp is cooled, a part of the cooling gas can cool the joint part, and the other part can cool the sealing part and the light emitting part. An ideal cooling balance can be created without using gas.

Further, the method for cooling a discharge lamp according to the present invention comprises:
A light emitting tube having a light emitting part in the center and a sealing part on both sides,
A pair of current introducing metal foils disposed in the sealing portion and fused to the arc tube, a pair of joining portions for joining the current introducing metal foil and a power supply line, and the joining portion When cooling the discharge lamp with a pair of bases provided to cover with cooling gas injected from a plurality of cooling nozzles, open an air hole in the base, one or more bases for one base. Cooling the joint by supplying a cooling gas injected from a cooling nozzle to the inside of the die through the air hole,
The sealing portion and the light emitting portion are cooled by propagating cooling gas injected from at least one other cooling nozzle from the outer peripheral surface of the base to the outer peripheral surface of the arc tube. With this configuration, it is possible to cool the joint with a part of the cooling gas and to cool the sealing part and the light emitting part with the other part, which is ideal without using an enormous amount of cooling gas. A proper cooling balance can be created.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing the internal structure of the sealing portion on the anode side and the base in the discharge lamp according to the embodiment of the present invention. In this figure, components corresponding to those in FIG. 6 are denoted by reference numerals used in FIG. As shown in FIG.
The discharge lamp of the present embodiment has a base 12 with a base air hole (hereinafter simply referred to as an air hole) 17. Other configurations are shown in FIG.
It is the same as the discharge lamp.

FIG. 2 is a view for explaining a method for cooling the discharge lamp according to the embodiment of the present invention, and a cross-sectional view showing an example of the structure of the base. As shown in FIG.
-2, a pair of air holes 17
-2, 17-4 are formed. A pair of cooling nozzles for blowing a cooling gas to the second base 12-2 are arranged around the second base 12-2. One cooling nozzle injects a cooling gas in the direction of A in the figure, and the other cooling nozzle injects a cooling gas in the direction of B in the figure.
The cooling gas injected in the direction A collides with the outer peripheral surface of the second base 12-2, and then rises along the outer peripheral surface of the arc tube 2, whereby the second sealing portion T and the second light emitting portion Cool S. The cooling gas injected in the direction B enters the inside of the second base 12-2 through the air hole 17-2, cools the second joint U, and passes through the air hole 17-4 to the outside. Exit. Therefore, B
The temperature of the second joint portion U and its surroundings can be suppressed by the cooling gas injected in the direction A, and the cooling gas injected in the direction A is supplied to the second sealing portion T and the second light emitting portion S. Can turn around and cool those parts appropriately. This makes it possible to create an ideal cooling balance for each part of the discharge lamp without using an enormous amount of cooling gas. Although FIG. 2 shows a method for cooling the second base, the first base can be cooled in the same manner.

FIG. 3 is a sectional view showing another two examples of the structure of the second die. In the structure shown in FIG.
An air hole 17-3 is formed in the middle (at a position separated by 90 °) between the air holes 17-3. In this case, the cooling gas injected in the direction of B enters the inside of the second base 12-2 through the air hole 17-2, cools the second joint U, and cools the air hole 17-3. And 17-4
Through to the outside. The flow of the cooling gas injected in the direction A is the same as in FIG. Also, in the structure shown in FIG. 3B, the air holes 17-5 and 17-6 for discharging the cooling gas to the outside of the base are more air holes 17-4 than the air holes 17-4 in FIG. It is formed at a position close to -2. And B
The cooling gas injected in the direction of the arrow enters the inside of the second base 12-4 through the air hole 17-2, cools the second joint U, and passes through the air holes 17-5 and 17-6. To the outside. The flow of the cooling gas injected in the direction A is the same as in FIG.

FIG. 4 shows measurement data of the relationship between the temperature of each part during the operation of the discharge lamp shown in FIGS. 1 and 2 and the flow rate of the cooling gas. Here, the specifications of the discharge lamp other than the structure of the base,
The relationship between the temperature measurement site and the flow rate of each nozzle is the same as when the data in FIG. 9 was measured. As can be seen from FIG. 4, according to the method for cooling a discharge lamp according to the embodiment of the present invention, 14
By using a cooling gas of about 0 liter, the first and second light emitting units R and S, the first and second second sealing units Q and T, and the first and second bonding units P and U can be set to each appropriate temperature.

As described above, according to the embodiment of the present invention, the temperature of the junction and the surrounding area can be suppressed by the cooling gas injected in the direction B, so that the current introducing metal foil is heated to a high temperature. Thus, cracks in the sealing portion caused by thermal expansion can be prevented. In addition, since a large amount of cooling gas does not flow into the light emitting unit, it is possible to prevent non-evaporation of mercury due to supercooling. Further, since the sealing portion and the light emitting portion can be cooled by the cooling gas injected in the direction A, the life of the discharge lamp is shortened due to the high temperature of the light emitting portion, and the risk of explosion is increased, and It is possible to prevent the sealing portion crack due to the thermal expansion of the current introducing metal foil due to the high temperature of the stopping portion and the first contact of the metal with the light emitting portion.

In the present invention, the air holes per cap may be set within a range of 70% or less of the total surface area of the side face of the cap while maintaining the strength of the cap.

[0027]

As described above in detail, according to the present invention, an air hole is made in the base of the discharge lamp, and a part of the cooling gas is propagated from the air hole to the inside of the base. To cool the sealing portion and the light emitting portion by propagating another part of the cooling gas from the outer peripheral surface of the base to the outer peripheral surface of the arc tube, thereby joining with a part of the cooling gas. Since the part can be cooled and the sealing part and the light emitting part can be cooled by the other part, an ideal cooling balance can be created without using an enormous amount of cooling gas.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure inside an anode-side sealing portion and a base in a discharge lamp according to an embodiment of the present invention;

FIG. 2 is a view for explaining a method of cooling the discharge lamp according to the embodiment of the present invention, and a cross-sectional view showing an example of a base structure;

FIG. 3 is a sectional view showing another two examples of the structure of the base in the discharge lamp according to the embodiment of the present invention;

FIG. 4 is a diagram showing measurement data of a relationship between the temperature of each part and the flow rate of a cooling gas during lighting of the discharge lamp shown in FIGS. 1 and 2,

FIG. 5 is a diagram showing a configuration of a conventional discharge lamp.

FIG. 6 is a cross-sectional view showing an anode-side sealing portion and a structure inside a base in a conventional discharge lamp;

FIG. 7 is a diagram showing a case where a cooling gas is blown to a base having no air hole in a conventional discharge lamp.

FIG. 8 is a diagram showing a temperature measurement site in a conventional discharge lamp.

FIG. 9 is a diagram showing measurement data of the relationship between the temperature of each part and the flow rate of the cooling gas when a cooling gas is blown to a conventional die having no air holes;

FIG. 10 is a diagram showing a case where a cooling gas is blown onto a base having an air hole in a conventional discharge lamp.

FIG. 11 is a diagram showing measurement data of the relationship between the temperature of each part and the flow rate of the cooling gas when a cooling gas is blown onto a conventional die having air holes.

[Explanation of symbols]

 2 arc tube 3 cathode 4 anode 11 and 12 base 15 power supply line 16 joint 17 air hole

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akiyoshi Fujimori 3-34-1, Chofugaoka, Chofu-shi, Tokyo F-term in Oak Manufacturing Co., Ltd. 5C035 HH14 5C039 AA02

Claims (2)

[Claims] 1. A light emitting tube having a light emitting portion at the center and a sealing portion on both sides, and a pair of metal foils for current introduction provided in the sealing portion and fused to the light emitting tube. A discharge lamp comprising: a pair of joints for joining the current introducing metal foil and a power supply line; and a pair of bases provided to cover the joints and having air holes. Causes a part of the cooling gas supplied from the outside to propagate from the air hole to the joining portion, and causes another part of the cooling gas to propagate from the outer peripheral surface of the base to the outer peripheral surface of the arc tube. Discharge lamp characterized in that: 2. A light emitting tube having a light emitting portion at the center and a sealing portion on both sides, and a pair of current introducing metal foils disposed in the sealing portion and fused to the light emitting tube. A cooling gas injected from a plurality of cooling nozzles to a discharge lamp including a pair of joints for joining the current introducing metal foil and the power supply line, and a pair of bases provided to cover the joints. At the time of cooling, the joining is performed by opening an air hole in the base and supplying cooling gas injected from one or more cooling nozzles to one base through the air hole into the base. Cooling the sealing portion and the light emitting portion by propagating cooling gas injected from one or more other cooling nozzles from the outer peripheral surface of the base to the outer peripheral surface of the arc tube. Discharge lamp cooling method.