JPH04155741A - U-shaped discharge tube device - Google Patents

Abstract

PURPOSE:To effectively cool a discharge tube with liquid by putting a thermally opaque shade between two linear parts of the U-shaped tube. CONSTITUTION:A U-shaped discharge device is provided with a jacket 1, a U-shaped discharge tube 2, two straightening vanes 3a, 3b, a shade 4, and a base 5, etc. The shade 4 is made of thermally opaque member, and is put between each linear part 2a and 2b of the discharge tube 2. The straightening vanes 3a, 3b are formed out of transparent member, and are provided upright in opposition to the shade 4 at a point where the discharge tube 2 is sandwiched thereby. When the U-shaped discharge device is used, a cooling liquid is flown from the side of the one linear part 2a of the discharge tube 2 to the other linear part 2b, through a channel surrounded by the straightening vane 3a, the shade 4, and by the inner wall of the jacket 1, and is exhausted. Since the cooling liquid is constantly circulated in the channel formed along the discharge tube 2, the tube can thereby effectively be cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a discharge tube device used for exposure of printed wiring boards or photolithography, and particularly to a U-shaped discharge tube device with a liquid-cooled structure.

[Conventional technology]

BACKGROUND ART Long arc discharge tubes with a liquid-cooled structure are widely used as discharge tubes used for exposing printed wiring boards and the like because they are easy to light and inexpensive to manufacture.

However, long-arc discharge tubes have the disadvantage that it is difficult to obtain parallel light due to the long arc. Research is being conducted.

[Problem to be solved by the invention]

However, in order to put the U-shaped discharge tube into practical use, it was necessary to solve the following problems.

[11] Since the straight sections of the discharge tube are parallel to each other and close to each other, the straight sections are likely to be mutually heated by the radiant heat during discharge, resulting in overheating, which shortens the life of the discharge tube.

[21 In order to cool the discharge tube with liquid, it is conceivable to form a U-shaped water jacket made of quartz glass along the discharge tube, but it is difficult to form this water jacket.

[3] In order to avoid the above problem, it is possible to use an air cooling method, but air cooling does not provide sufficient cooling.

Further, dust is scattered and the exposed surface becomes dirty.

The present invention was devised in view of the above problems, and
It is an object of the present invention to provide a U-shaped discharge tube device having a liquid-cooled structure that prevents overheating of the straight portion of the discharge tube and is easy to manufacture.

[Means to solve the problem]

In order to solve the above problems, the present invention includes a U-shaped discharge tube erected approximately at the center of a plate-shaped base, and a hollow transparent jacket surrounding the discharge tube and attached to the base in a liquid-tight manner. a thermally opaque shielding plate interposed between the two straight sections of the discharge tube so as to substantially cover the inside of the jacket near the base; at least two transparent rectifier plates standing upright facing the plate; and liquid supply and drainage ports penetrating the base and opening on both sides of the shielding plate inside the jacket; It was constructed as a U-shaped discharge tube device in which cooling liquid was circulated through the jacket.

[Function] [11] Since a thermally opaque shielding plate is interposed between the two straight portions of the U-shaped tube, radiant heat during discharge is blocked and mutual heating is prevented.

[21 Since the shielding plate forms part of the inside of the jacket on the side closer to the base, a substantially U-shaped cooling channel is formed along the U-shaped tube together with the rectifying plate and the shielding plate.

Therefore, the discharge tube can be effectively cooled with liquid.

[31 The hollow jacket has a simple shape and is therefore easy to mold.

(Example〕 Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is an elevational view of a part of the U-shaped discharge tube device of the present invention in cross section, FIG. 2 is a view taken from the direction of the line ■-■ in FIG. 1, and FIG. 3 is the view shown in FIG. FIG. 4 is an enlarged view of the portion indicated by ■ in FIG. 1.

As shown in Figure 1, the U-shaped discharge tube device is
1, a U-shaped discharge tube 2, two rectifying plates 3a and 3b, a shielding plate 4, a disk-shaped base 5, and the like.

The jacket 1 is made of a transparent material such as quartz glass,
It has a hollow structure and is approximately bell-shaped.

The opening end 1a of this jacket 1 is as shown in FIG.
The base 50 is fluid-tightly attached to the base 5 via a seal ring 9.9 by a ring-shaped nut 6 that fits into a threaded portion 5a threaded on the periphery of the base 50. Therefore, when the ring-shaped nut 6 is tightened, the upper end 6a of the ring-shaped nut 6 presses the seal rings 9, 9 against the base 5, so that the cooling liquid filled in the jacket 1 does not leak to the outside.

Bases 2c, 2 of straight portions 2a, 2b of U-shaped discharge tube 2
d vertically penetrates approximately the center of the base 5, and the penetrating portion is sealed liquid-tight via a nut 10 and a seal packing 11. Note that connection hardware (not shown) for the power supply is fitted into the tips of the bases 2c and 2d.

The shielding plate 4 is formed of a so-called thermally opaque material that blocks heat rays but transmits light, such as transparent lead glass, and is located between the straight portions 2a and 2b of the U-shaped discharge tube 2. It is interposed and provided on the base 5 so as to substantially cover the inside of the jacket 1 on the side closer to the base 5. That is, as shown in FIG. 2, this shielding plate 4 has both ends in contact with the inner wall of the jacket 1, and as shown in FIGS. 1 and 3, its height is equal to that of the U-shaped discharge tube 2. straight line part 2
It is formed to have approximately the same dimensions as the heights of a and 2b. This shielding plate 4 blocks the radiant heat emitted from the discharge tube 2 to prevent the linear portions 2a and 2b from heating each other, and works in cooperation with rectifying plates 3a and 3b, etc., which will be described later, to prevent the discharge tube from being heated.
Its role is to form a flow path for the cooling liquid that can effectively cool the liquid.

The rectifying plates 3a and 3b are made of a transparent member such as quartz glass, and are erected on the base 5 opposite the shielding plate 4 at positions across the U-shaped discharge tube 2. As shown in FIGS. 1 and 2, the current plates 3a and 3b are formed so that their respective upper and side ends abut against the inner wall of the jacket 1.

The base 5 is provided with a liquid supply/drainage lower 8 that penetrates the base 5 and opens on both sides of the shielding plate 4, and drains a cooling liquid such as water from the liquid supply lower into the jacket 1. Mouth 8
is forced into circulation.

Hoses 7b and sb are attached to the lower liquid supply and drain 8 via connection fittings 7a and 8a attached to the bottom side of the base 5.

When using the above-mentioned U-shaped discharge tube device, follow the steps below.

First, the inside of the jacket 1 is filled with a cooling liquid such as water from the liquid supply lower, and the cooling liquid and air bubbles inside the jacket 1 are discharged from the liquid drain port 8, and the cooling liquid is drained from the liquid supply lower. Forcibly circulate to port 8. At this time, the cooling liquid, etc. flows from one straight section 1a side of the discharge tube 2 to the other straight section lb side through a flow path surrounded by the straightening plate 3a, the shielding plate 4, and the inner wall of the jacket 1, and flows through the flow path surrounded by the straightening plate 3a, the shielding plate 4, and the inner wall of the jacket 1. Shielding plate 4
The liquid is then discharged from the discharge port 8 through a flow path surrounded by the inner wall of the jacket 1. Since the cooling liquid and the like constantly circulate within the flow path formed along the discharge tube 2, the discharge tube 2 can be efficiently cooled. In addition, the current plates 3a, 3b and the jacket l
The area surrounded by the inner wall is also filled with coolant that has entered through gaps and is constantly flowing.

Here, when the U-shaped discharge tube 2 is discharged, the discharge tube 2 emits ultraviolet rays including heat rays, but the straight portions 2a, 2
b are shielded by the shielding plate 4, so they do not heat each other and overheating is prevented.

Note that the present invention is not limited to the above-mentioned embodiments. For example, the jacket may have a rectangular shape with a square cross section and a flat top, or a columnar shape with a polygonal cross section. Various changes may be made without departing from the gist of the invention, such as the fact that the light may be formed in different shapes, and that the orientation at the time of installation may be sideways or downward instead of emitting light upward. Of course you can.

〔Effect of the invention〕

Since the present invention is configured as described above, the following effects are achieved.

(1) Since a thermally opaque shielding plate is interposed between the two straight portions of the U-shaped tube, radiant heat during discharge is blocked and mutual heating is prevented.

(2) Since the shielding plate forms a portion of the inside of the jacket on the side closer to the base, a substantially U-shaped cooling channel is formed along the U-shaped tube together with the current plate and the shielding plate.

Therefore, the discharge tube can be effectively cooled with liquid.

(3) A hollow structure jacket has a simple shape and can be easily molded, thus enabling a liquid cooling structure.

[Brief explanation of the drawing]

FIG. 1 is an elevational view of a part of the U-shaped discharge tube device of the present invention in cross section, FIG. 2 is a view taken from the direction of the line ■-■ in FIG. 1, and FIG. 3 is the view shown in FIG. FIG. 4 is an enlarged view of the portion indicated by ■ in FIG. 1. 1...Jacket 2...U-shaped discharge tube 2a, 2b...Straight line portions 3a, 3b of U-shaped discharge tube
... Rectifier plate 4 ... Shielding plate 5 ... Base 6 ... Ring-shaped nut 7 ... Coolant supply port 8 ... Coolant drain port

Claims (1)

[Claims] A U-shaped discharge tube erected approximately at the center of a plate-shaped base, a hollow transparent jacket surrounding the discharge tube and attached to the base in a liquid-tight manner, and a side of the interior of the jacket close to the base. a thermally opaque shielding plate interposed between the two straight sections of the discharge tube so as to substantially bisect the discharge tube; and at least two shielding plates erected facing the shielding plate across each straight section of the discharge tube. a transparent rectifier plate, and liquid supply/drainage ports penetrating the base and opening on both sides of the shielding plate inside the jacket, and circulating the cooling liquid in the jacket through the liquid supply/drainage ports. A U-shaped discharge tube device.