JPS61294753A - Short-arc type discharge lamp device - Google Patents

Abstract

PURPOSE:To stabilize discharge while to improve break resistance of lamp and to reduce damage due to breakdown by inserting a discharge lamp into a pipe formed shorter than the shortest distance between the base metal sections. CONSTITUTION:The overall length L of pipe 7 is determined shorter than the shortest distance between the base metal sections 2, 3 such that each base metal section 2, 3 will project from the opposite open end sections of pipe 7. Since the lamp will radiate light in longitudinal direction with some radiation angle (a) (shown by dot line) the length L of lamp 7 is selected to cover said range (a) sufficiently. When containing such short-arc discharge lamp in a casing 6, flow of cold wind is never dispersed to cool the base metal section while simultaneously to maintain the valve at predetermined high temperature thus to lengthen the service life while to stabilize the spectrum and the brightness of emitted light. Since the silicon glass pipe 7 will prevent dispersion of chips upon breakdown of lamp, the parts in the casing 6 is protected from damage.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a short-arc discharge lamp device, and more particularly to a short-arc discharge lamp device that can sufficiently cool base portions at both ends of the lamp.

(Background of the Invention) Short arc discharge lamps such as ultra-high pressure mercury lamps are widely used, for example, as light sources for exposure equipment for semiconductor manufacturing.

FIG. 5 shows a conventional short-arc discharge lamp. This short-arc discharge lamp consists of a lamp bulb 1 made of quartz glass, a base 2.3 at both ends of the lamp bulb 1, and a pair of caps 2.3 provided on the bulb 1. It is composed of electrodes 4 and 5.

Such a short arc discharge lamp must satisfy the following conditions.

(2) The central part of the lamp pulp, that is, the light emitting part, is maintained at a desired high temperature below the softening point of the quartz glass (bulb 1).

This first condition is necessary to stabilize the discharge between the electrodes and to keep the bright spot constant.

■Keep the mouthpiece cool.

Since the thermal expansion of the cap is different from that of quartz glass, if the cap gets hot, the quartz glass will crack at the cap, and there is a risk that the lamp bulb will burst.

However, with conventional lamp devices, it has not been possible to perform cooling that satisfies conditions (1) and (2) above at the same time.

(Object of the Invention) The present invention solves the above-mentioned drawbacks, stabilizes the discharge of a short-arc discharge lamp, makes the lamp less likely to burst, and creates a short arc that causes less harm to the surroundings of the lamp even if it bursts. The purpose is to obtain a type discharge lamp device.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

(Embodiment) FIG. 1 is a schematic sectional view of a short arc discharge lamp device according to a first embodiment of the present invention. In FIG. 1, there is shown a lamp bulb 1 made of quartz glass, and base portions 2 at both ends of the lamp bulb 1.
3 and a pair of electrodes 4.5 in the lamp bulb 1.
supported within. A cylindrical quartz glass pipe 7 with both ends open is inserted into the outer periphery of the lamp bulb 1. As will be described later, the pipe 7 is also supported by the casing 6 by a support member, and the diameter of the pipe 7 is determined so as to have a predetermined gap with the lamp bulb 1. Further, the total length of the pipe 7 is determined to be shorter than the length Lo of the shortest interval between the mouthpieces 2.3 so that each mouthpiece 2.3 protrudes from both open ends of the pipe 7. Since the lamp emits light in the light emission angle range α in the longitudinal direction of the lamp (dotted line) as shown in the figure, the length of the pipe 7 is selected to sufficiently cover the light emission angle range α. There is.

On the other hand, a ventilation opening 6a is provided on the side of the casing 6, from which a ventilation fan 8 blows cold air to the casing 6.
In addition, an exhaust opening 6b is provided above the casing 6 and above the upper base portion 2 of the lamp, and an intake fan 9 is provided here. A condensing lens 10 that receives light from the light emission angle range α is arranged on the side of the lamp.

The cold air sent into the casing 6 by the ventilation fan 8 is directly applied to both caps 2.3.
3 can be sufficiently cooled. In addition, since the cold air is blocked by the quartz glass pipe 7, it does not directly hit the lamp bulb 1, so that the light emitting portion of the lamp bulb 1 can be maintained at a high temperature.

However, in order to prevent the temperature of the light emitting section from becoming too high, the intake fan 9 circulates a certain amount of cold air within the pipe 7 to maintain the light emitting section at a desired high temperature. ing. When the lamp is used as a light source of an exposure apparatus for semiconductor manufacturing, the light transmitted through the lens 10 is projected onto a semiconductor substrate (not shown) for pattern formation.

If such a short-arc discharge lamp device is built into the casing 6, the flow of cold air will not be diffused (because it is easy to cool the base and maintain a constant high temperature of the bulb at the same time). This not only extends the life of the lamp, but also eliminates fluctuations in the light emitting point between the electrodes, making it possible to stabilize the emission spectrum and luminance.Furthermore, even if the lamp ruptures, the quartz glass Since the pipe 7 prevents fragments of the lamp from scattering, parts inside the casing 6 such as the condenser lens 10 will not be destroyed.

In the first embodiment described above (see FIG. 1), the light from the discharge lamp is focused by the lens 10. !
5! In addition to the ventilation fan 8 that cools each base 2.3 of the lamp bulb 1, an intake fan 9 is required to ventilate the inside of the pipe 7. Next, an elliptical mirror was used instead of the lens 100. A second embodiment will be described with reference to FIG. 2, in which a single fan cools each mouthpiece and blows air into the pipe.

・Those with the same numbers as in FIG. 2 and FIG. 1 are the same parts, and the relative positional relationship between the lamp bulb 1 and the pipe 7 and the size of the pipe 7 are the same as in FIG. 1. , the explanation thereof will be omitted.

In FIG. 2, an ellipse all is housed in the casing 6, an opening 11a is provided at the lower part of the elliptical mirror 11, and an opening 11b through which the pipe 7 passes is provided at the upper part of the elliptical mirror 11. It is provided. Further, an outer II end of a plate-shaped support member 12 is fixed to the inner wall surface of the casing 6. The upper part of the pipe 7 is fixed to a cylindrical attachment part 12a provided at the center of the support member 12. In this way, the pipe 7 is supported by the casing 6 by the support member 12.

The support member 12 is attached by providing a large number of ventilation holes 13 around the portion 12a, and furthermore, a roof portion 14 is continuously formed around the portion 12a, and a lamp is provided on the top of the roof portion 14. An exhaust port 15 is formed to face the periphery of the upper mouthpiece 2 of the valve 1 with a gap therebetween. One end of the rod-shaped support member 16 is fixed to the casing 6, and the other end supports the base portion 3 at the bottom of the lamp. An intake fan 18 is provided above the exhaust opening 17 provided in the upper part of the casing 6.
is located. The intake fan 18 cools each mouthpiece and blows air through the pipes, as described above.

Since a reflecting mirror 19 is arranged obliquely below the aperture 11a, the light beam (point &s in the figure) from the light emitting part of the lamp bulb 1 is reflected by the elliptical mirror 11, and the aperture 11a
a and the reflecting mirror 19.

By the rotation of the intake fan 18, most of the air is sucked into the elliptical mirror 11 from the lower part of the casing 6, so that the lower base part 3 can be sufficiently cooled, and the gap between the lamp bulb 1 and the pipe 7 can be sufficiently cooled. The temperature of the light emitting part of the lamp bulb 1 can be maintained at a desired high temperature by a small amount of air flowing through the lamp bulb 1. In addition, air flowing into the gap between the opening 11b and the pipe 7 via the pipe 7 and the elliptical mirror 11, and the elliptical mirror 1
Since the air flowing to the outside of the cap 1 flows toward the upper cap portion 2 through the vent 13, the cap portion 2 can be sufficiently cooled.

Note that if the temperature sensor is used to measure the temperature of the lamp bulb 1 and the rotation of the intake fan 18 is controlled based on the measurement result, the temperature inside the lamp bulb 1 can be controlled to a higher temperature. I can do it.

As mentioned above, the shape of each quartz glass pipe in the first embodiment (see Fig. 1) and the second embodiment (see Fig. 2) was cylindrical. For example,
This will be explained based on FIGS. 3 and 4.

First, in FIG. 3, by making the opening at the bottom of the quartz glass pipe 20 small, the flow rate of air flowing into the gap through the opening is small (as a result, the light emitting part of the lamp bulb 1 is You can get away with not having to cool it down.

Next, in FIG. 4, by making the quartz glass pipe 21 follow the shape of the lamp bulb 1, air flows at a constant speed over the entire surface of the pulp, improving the cooling state of the light emitting part. can.

The embodiments described above are effective not only for ultra-high-pressure mercury lamps but also for short-arc xenon lamps and the like.

(Effects of the Invention) As described above, according to the present invention, since the discharge lamp is inserted into the formed pipe, the discharge of the discharge lamp can be stabilized. In addition, it is possible to obtain a short arc discharge lamp device in which the lamp is less likely to be damaged and causes less damage to the surroundings of the lamp even if it ruptures.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a short arc discharge lamp device according to a first embodiment of the present invention. FIG. 2 is a schematic sectional view of a short arc discharge lamp device according to a second embodiment of the present invention. Figures 3 and 4 are schematic sectional views showing modified examples of the pipe = [Explanation of symbols of main parts]

Claims (1)

[Claims] 1. A short arc discharge lamp having a light emitting part in the center and base parts at both ends; a ventilation part for cooling the lamp by passing cold air through the short arc discharge lamp; and; in a short arc discharge lamp device having both ends open and having a total length shorter than the shortest distance between the caps, each of the caps protrudes from each open end. A short arc discharge lamp device comprising a quartz glass pipe that surrounds a discharge lamp with a predetermined gap. 2. The light from the lamp is emitted in a certain angular range in the longitudinal direction of the lamp, and the quartz glass pipe has a length that covers all the emitted light in the angular range. The short arc discharge lamp device according to item 1.