JP4401406B2 - Light source device - Google Patents

Description

  The present invention relates to a light source device that optically processes a workpiece such as a semiconductor, a liquid crystal, or a printed circuit board, and more particularly, to a light source device that realizes an ideal cooling balance by appropriately cooling a base portion of a discharge lamp.

  Conventionally, as a discharge lamp for optically processing a workpiece such as a semiconductor, a liquid crystal, or a printed circuit board, for example, there is one shown in FIG. The discharge lamp includes an arc tube 2, a cathode 3, an anode 4, a first internal lead 5, a second internal lead 6, a first bead tube 7, a second bead tube 8, a first quartz glass rod 9, and a second quartz glass. A rod 10, a first base 11, and a second base 12 are provided.

  The arc tube 2 has a light emitting portion formed in a substantially spherical or elliptical shape with quartz glass, and a pair of sealing portions formed in a tubular shape on both sides thereof. Inside the light emitting portion, the cathode 3 and the anode 4 are opposed to each other. A first internal lead 5 is connected behind the cathode 3, and a second internal lead 6 is connected behind the anode 4. The first internal lead 5 is inserted through the first bead tube 7 and the rear end thereof 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 thereof is inserted into the second quartz glass rod 10.

  A first base 11 is fixed to the outside of the portion containing the first quartz glass rod 9 in the sealing portion, and a second base 12 is placed outside the portion containing the second quartz glass rod 10. Is fixed.

  FIG. 6 is a cross-sectional view illustrating the internal structure of the sealing portion on the anode side and the base in FIG. 5. As shown in FIG. 5, the second internal lead 6 is inserted into one end (the end on the anode side) of the second quartz glass rod 10. The other end of the second quartz glass rod 10 is inserted with the tip end side of a current introducing metal rod 14. A power supply line 15 is connected to the rear end side of the current-introducing metal rod 14 via a joint 16. Further, a current introducing metal foil (not shown) is disposed on the outer peripheral surface of the second quartz glass rod 10 and is melt-adhered to the inner surface of the arc tube 2. And the 2nd nozzle | cap | die 12 is arrange | positioned so that the said junction part 16 may be covered. Although the anode side sealing portion has been described above, the structure on the cathode side is the same.

  The arc tube 2 sealed in this manner is filled with a discharge medium made of mercury and a rare gas such as argon or xenon to constitute a high-pressure discharge lamp.

The ideal cooling balance during lighting in the discharge lamp configured as described above will be described. First, the light emitting part is ideally 500 to 800 ° C. in order to avoid unevaporated mercury at a low temperature and the risk of explosion at a high temperature. Also, the sealing portion is ideally 400 ° C. or lower in order to prevent sealing portion cracking due to thermal expansion of the current-introducing metal foil and peeling of the metal foil on the light emitting portion side. Further, the joint 16 between the power supply line 15 and the current introduction metal rod 14 is used to prevent the occurrence of a crack in the sealing portion due to oxidation of the junction 16 and its surroundings and the accompanying thermal expansion of the current introduction metal rod 14. 100 ° C. or lower is ideal. In order to create such an ideal cooling balance, a method of blowing gas (air, nitrogen gas, etc.) to the base of the discharge lamp has been generally performed.
JP 2001-216938 A

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

  FIG. 7 is a diagram showing a case where cooling gas is blown onto a die having no air holes. FIG. 7A is a perspective view, and FIG. 7B is a horizontal cross section of the cap portion. As shown in FIG. 7, when the cooling gas is blown to the base 12 having no air holes by the cooling nozzles in the directions of A and B which are different by 90 ° in the same horizontal plane, the feeder 15 and the current are introduced. If the joint 16 with the metal rod 14 is cooled so that it is within the proper temperature (100 ° C or less), the flow rate of the cooling gas becomes enormous, the light emitting part is cooled too much, and mercury is not evaporated. Resulting in. The reason for this is that, as shown in FIG. 7A, the cooling gas that has collided with the base 12 travels to the arc tube 2 as shown by the curves E1 and F1 to lower the temperature of the arc tube 2.

As shown in FIG. 8, in the light emitting part, the cathode side is the first light emitting part R, the anode side is the second light emitting part S, the cathode side sealing part is the first sealing part Q, and the anode side sealing part is the first side. 2 The sealing part T, the cathode-side joining part as the first joining part P, the anode-side joining part as the second joining part U, and the first nozzle by the cooling nozzles in the directions of C and D different by 90 ° in the same horizontal plane. When the cooling gas is blown to 11 and the cooling gas is blown to the second base 12 by the cooling nozzles in the directions of A and B described above, the temperature of each part and the cooling gas (in this case, air) The measurement data of the relationship with the flow rate is shown in the characteristic curve diagram of FIG. In addition, the 2nd light emission part S of FIG. 8, the 2nd sealing part T, and the 2nd junction part U respond | correspond to S, T, and U in FIG. 6, respectively. That is, the second light emitting portion S and the second sealing portion T exist on the surface of the arc tube, and the second joint portion U is the joint portion 16 itself. The same applies to the first light emitting portion R, the first sealing portion Q, and the first joint portion P. In addition, this measurement is adjusted so that an equal amount of cooling gas is ejected from each nozzle, and the specifications of the discharge lamp used are as follows.
Voltage: about 50V, current: about 100A, power: about 5kW, light emitting part diameter: φ82mm, mercury content: about 30mg / cc

  As shown in the characteristic curve diagram of FIG. 9, in order to keep the first joint portion P and the second joint portion U at 100 ° C. or less, a huge amount of cooling gas of about 250 liters per minute is required. And in that case, it turns out that the temperature of the 2nd light emission part S will fall to about 450 degreeC.

  On the other hand, in order to efficiently cool the joint portion, 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. A discharge lamp having a two-piece base 12-1 is also known. Here, there is an air hole 17-3 at a position where the air hole 17-1 is extended straight, and there is an air hole 17-4 at a position where the air hole 17-2 is extended straight. The line segment connecting the air hole 17-1 and the air hole 17-3 and the line segment connecting the air hole 17-2 and the air hole 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 A direction passes from the air hole 17-1 to the air hole 17-3 as shown by F2, and the light emitting part and the sealing part Do not turn. Similarly, the cooling gas injected from the nozzle in the B direction passes through like E2 and does not turn to the light emitting part and the sealing part. For this reason, the light emitting part and the sealing part are not cooled sufficiently and become high temperature. As a result, it is inevitable that the life of the discharge lamp is shortened and the risk of explosion is increased due to the high temperature of the light emitting part. Moreover, when the sealing part becomes high temperature, there is a risk of inducing cracks in the sealing part and peeling of the metal foil due to thermal expansion of the metal foil for current introduction.

  Measurement data of the relationship between the temperature of each part during lighting of the discharge lamp shown in FIG. 10 and the flow rate of the cooling gas is shown in the characteristic curve diagram of FIG. Here, the relationship between the specification of the discharge lamp and the flow rate of each nozzle is the same as in the data measurement of FIG.

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

  In addition, it has been confirmed from experimental data that each part can be brought to an appropriate temperature by increasing the flow rate of the cooling gas, but in reality, the flow rate of the cooling gas and the exhaust capacity vary depending on the mechanical device. Therefore, it is not always possible to ensure an appropriate temperature for all discharge lamps.

  The present invention has been made in view of such problems, and provides a discharge lamp capable of creating an ideal cooling balance without using a huge amount of cooling gas and a cooling method thereof. It is for the purpose.

A light source device according to the present invention includes a discharge lamp having a sealing portion provided continuously to a light emitting portion, a base fixed to the sealing portion, and means for cooling the base with a cooling gas. ,
In the light source device provided with a plurality of air holes in the base, and configured so that the circumferential surface of the base is cooled by the cooling gas from two different directions,
The plurality of air holes are in a positional relationship that do not oppose each other in the circumferential direction, one of the plurality of air holes is an inflow hole for cooling gas, and the other air hole is an outflow hole for the cooling gas, The outer peripheral surface of the base in which the plurality of air holes are not formed is used as the cooling gas spraying surface.

  According to the present invention, a plurality of air holes are formed in the base of the discharge lamp, and the joint is cooled by allowing a part of the cooling gas to flow into the base from the air hole, and the other cooling gas is supplied. By cooling a sealing part and a light emitting part by propagating a part from the outer peripheral surface of the base to the outer peripheral surface of the arc tube, the joint part is cooled with a part of the cooling gas and sealed with the other part. Since the stop portion and the light emitting portion can be cooled, an ideal cooling balance can be created without using a huge amount of cooling gas.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing the internal structure of an anode-side sealing portion and a base in a discharge lamp according to an embodiment of the present invention. In FIG. 1, the components corresponding to those in FIG. As shown in FIG. 1, the discharge lamp according to the present embodiment includes a base air hole (hereinafter simply referred to as an air hole) 17 in a base 12. Other configurations are the same as those of the discharge lamp of FIG.

FIG. 2 is a perspective view for explaining a method of cooling the discharge lamp according to the embodiment of the present invention.

As shown in FIG. 2, a plurality of air holes are formed in the outer peripheral surface of the second base 12-2 . As shown in the cross-sectional view of FIG. 3, a plurality of air holes 17-2, 17-5, and 17-6 are formed in a positional relationship that does not face each other . A pair of cooling nozzles for blowing a cooling gas to the second base 12-2 is disposed around the second base 12-2. One cooling nozzle injects a cooling gas in the direction A in the figure, and the other one cooling nozzle injects a cooling gas in the direction B in the figure.

The cooling gas sprayed 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 S. Cool down. Further, 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 sets the air holes 17-5 and 17-6 . Passes through the passages E5 and E6 to the outside.

  Therefore, the cooling gas injected in the B direction can suppress the temperature of the second joint portion U and its surroundings, and the cooling gas injected in the A direction includes the second sealing portion T and the second light emitting portion S. You can go around and cool those parts moderately. This makes it possible to create an ideal cooling balance for each part of the discharge lamp without using a huge amount of cooling gas. In addition, although FIG. 2 showed the method of cooling a 2nd nozzle | cap | die, a 1st nozzle | cap | die can also be cooled by the same method.

  The measurement data of the relationship between the temperature of each part during lighting of the discharge lamp shown in FIGS. 1 and 2 and the flow rate of the cooling gas is shown in the characteristic curve diagram of FIG. Here, the relationship between the specifications of the discharge lamp other than the structure of the base, the temperature measurement site, and the flow rate of each nozzle is the same as in the data measurement of FIG. As is clear from FIG. 4, according to the cooling method for the discharge lamp of the embodiment of the present invention, the first and second light emitting units R, S, The first and second sealing portions Q and T and the first and second joint portions P and U can be set to appropriate temperatures.

  As described above, according to the embodiment of the present invention, the temperature of the joint and its surroundings can be suppressed by the cooling gas jetted in the B direction, so that the current-introducing metal foil becomes hot and thermally expands. The generated sealing part crack can be prevented. In addition, since a large amount of cooling gas does not circulate to the light emitting portion, it is possible to prevent the occurrence of non-evaporation of mercury due to overcooling. Further, since the sealing portion and the light emitting portion can be cooled by the cooling gas injected in the A direction, the life of the discharge lamp is shortened and the risk of rupture increases due to the high temperature of the light emitting portion, and the sealing is performed. It is possible to prevent sealing portion cracks due to thermal expansion of the current-introducing metal foil due to the high temperature of the portion, and light-emitting portion side adhesion peeling of the metal foil.

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

Sectional drawing which shows the structure of the inside of the sealing part by the side of the anode in the embodiment of the discharge lamp of this invention, and a nozzle | cap | die, The perspective view for demonstrating embodiment of the method of cooling the discharge lamp of this invention , Sectional drawing which shows an example of the structure of the nozzle | cap | die in embodiment of the discharge lamp of this invention, FIG. 3 is a characteristic curve diagram showing measurement data of the relationship between the temperature of each part during lighting of the discharge lamp shown in FIGS. 1 and 2 and the flow rate of the cooling gas; A longitudinal sectional view showing the configuration of a conventional discharge lamp, Sectional drawing which shows the internal structure of the sealing part on the anode side in a conventional discharge lamp, and a nozzle | cap | die, A perspective view and a cross-sectional view showing a state in which cooling gas is blown to a base without an air hole in a conventional discharge lamp, The figure which shows the temperature measurement site | part in the conventional discharge lamp, A characteristic curve diagram showing measurement data of the relationship between the temperature of each part and the flow rate of the cooling gas when the cooling gas is blown onto a conventional base without air holes, A perspective view and a cross-sectional view showing a state in which a cooling gas is blown to a base having an air hole in a conventional discharge lamp, It is a characteristic curve figure which shows the measurement data of the relationship between the temperature of each part at the time of spraying the cooling gas to the nozzle | cap | die with the conventional air hole, and the flow volume of the said cooling gas.

Explanation of symbols

2 arc tube 3 cathode 4 anode
11, 12 base
15 Feed line
16 joints
17 Air hole

Claims (1)

A discharge lamp having a sealing portion connected to the light emitting portion, a base fixed to the sealing portion, and means for cooling the base with a cooling gas;
In the light source device provided with a plurality of air holes in the base, and configured so that the circumferential surface of the base is cooled by the cooling gas from two different directions,
The plurality of air holes are in a positional relationship that do not oppose each other in the circumferential direction, one of the plurality of air holes is an inflow hole for cooling gas, and the other air hole is an outflow hole for the cooling gas, A light source device characterized in that an outer peripheral surface of the base in which the plurality of air holes are not formed is a partial spraying surface of the cooling gas.

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