JP3481175B2 - Dielectric barrier lamp - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp, and more particularly to a dielectric barrier lamp used in an ultraviolet exposure device or the like.

[0002]

2. Description of the Related Art In order to manufacture semiconductor integrated circuits (ICs), liquid crystal display panels (LCDs), printed circuit boards (PCBs) and the like, it is common to use a photo-curing resin (resin) and an ultraviolet exposure device. is there. A mercury lamp, a dielectric barrier lamp, or the like is used in such an exposure apparatus.

In the dielectric barrier lamp, the discharge vessel is filled with a discharge gas for forming excimer molecules, and the excimer molecules are formed by an ozonizer discharge or a dielectric barrier discharge. It is a lamp that takes out the light emitted from the excimer molecule. Conventional examples of such a dielectric barrier lamp are disclosed in Japanese Patent Laid-Open Nos. 7-14553 and 7-1455.
No. 4 and Japanese Patent Laid-Open No. 6-310104, “Dielectric Barrier Discharge Lamp”. As shown in FIG. 5, such a conventional example has a discharge vessel 1, an inner tube 2, an outer tube 3, electrodes 4, 5, a getter 6, a discharge space 7, a power source 8 and a protrusion 9. Discharge container 1 having a substantially cylindrical outer shape
The discharge space 7 is filled with a discharge gas that forms excimer molecules by dielectric barrier discharge. At least a part of the discharge vessel 1 also serves as a dielectric of the dielectric barrier discharge, and at least a part of the discharge gas is transparent to the light emitted from the excimer molecules. Conductive mesh electrodes 4 and 5 are provided on at least a part of the light-transmitting dielectric to form a dielectric barrier discharge lamp. At least one group of strands forming the conductive mesh electrode is arranged so as to intersect the axes 10a-10b of the discharge vessel 1 at an angle.

Further, another conventional example of the dielectric barrier discharge lamp device is disclosed in, for example, Japanese Unexamined Patent Publication No. 8-153493. This conventional example is shown in FIG. This dielectric barrier discharge lamp device includes a plurality of dielectric barrier discharge lamps 1 each having the same structure as the dielectric barrier discharge lamp shown in FIG.
Two V-shaped light reflectors having a, 1b, 1c and apex 12
11, 13, light extraction window 20, lamp house 21, cooling block 22, inert gas inlet 23 such as nitrogen gas, inert gas outlet 24, discharge gas filled space 26, light reflection plate 27 and cooling fluid It is composed of passages 28 and 29.

As described above, the light-transmissive discharge vessel having a substantially cylindrical outer shape, the metal mesh electrode provided on the entire circumference of a part of the outer surface of the discharge vessel, and the discharge vessel inside the electrode are called the discharge vessel. A plurality of cylindrical dielectric barrier discharge lamps 1a to 1 composed of an inner electrode provided coaxially and a discharge gas filled in the discharge vessel to form excimer molecules by dielectric barrier discharge.
c and these plural lamps are arranged in parallel and stored,
A dielectric barrier discharge lamp device including a lamp house (21) having a light extraction window (20) for extracting excimer light emitted from excimer molecules, and a power supply for performing dielectric barrier discharge. And a plurality of adjacent lamps as described above
V-shaped light reflecting plates 11 and 13 are provided between the two to increase the luminous intensity and to obtain relatively uniform parallel light from a light extraction window 20 over a wide range.

[0006]

However, the above-mentioned conventional dielectric barrier discharge lamp lacks vibration, shock, and thermal stability because the linear external electrode is spirally wound around the outer circumference of the arc tube. . In addition, sufficient light emission output required for recent exposure apparatuses such as ICs, LCDs and PCBs cannot be obtained.
Furthermore, when a plurality of dielectric barrier discharge lamps are used, there is a problem that the size becomes large and power consumption increases.

Accordingly, the object of the present invention is to provide excellent stability,
Another object of the present invention is to provide a dielectric barrier discharge lamp having high luminous efficiency.

[0008]

According to the dielectric barrier lamp of the present invention, the casing is arranged outside the arc tube, and the spiral groove and the protrusion are formed on the inner surface of the casing. Further, by using the thin metallic strip-shaped electrode as external electrodes of the outer periphery of the arc tube, characterized in that it tightly held on the outer surface of the arc tube met with this in a spiral groove of the casing.

[0009] The strip Jogaibu electrodes, a large number of openings are formed in a mesh shape, emits radiation from the arc tube efficiently to the outside of the light-emitting tube as a high aperture ratio. Also, the internal electrodes are
A metal rod-shaped electrode is inserted into the central hole of the arc tube, and an electrode holding portion is arranged at least at one end. The high frequency drive voltage is applied to the inner electrode and the outer electrode, preferably via an electrode fixing plate.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The structure and operation of a preferred embodiment of the dielectric barrier lamp according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a vertical sectional view of a preferred embodiment of a dielectric barrier lamp according to the present invention. The structure of the dielectric barrier lamp 100 will be described. This dielectric barrier lamp 100, a conductive metal rod electrode 101 which is assembled to the lamp center, double structure arranged around the terminal 102 and the electrode 10 1 to apply a high frequency driving voltage is provided to the electrode 101 or The arc tube 103 having a coaxial structure is included. A rare gas such as argon or xenon is sealed in the discharge space 104 that is sealed by the outer tube and the inner tube that form the arc tube 103. This arc tube 103
Is formed of a light (ultraviolet) transmitting material such as quartz glass. The electrode 101 is inserted, and insulating electrode holding members 105 and 106 are arranged on both sides of the arc tube 103.

[0012] The dielectric barrier lamp 100 further housing portion 107, a thin metal strip shape disposed on the outside of the arc tube 103 and the helical external electrodes 108 and Figures 2-4
As shown, it has an electrode fixing plate 110 attached to the casing 107 . Protrusions 112 for holding the spiral external electrodes 108 and grooves 113 are alternately formed in a portion of the casing 107 facing the arc tube 103.

Next, FIGS. 2 and 3 are cross-sectional views of the dielectric barrier lamp 100 according to the present invention shown in FIG. 1 in the vicinity of an end portion and an intermediate portion thereof. In addition, FIG. 4 is a view showing the outer appearance of the dielectric barrier lamp 100 according to the present invention. Figure 4
The dielectric barrier lamp 1 of the present invention, as best shown in FIG.
00 is that it forms a large number of openings 1 11 to the external electrodes 108 disposed formed on the outer circumference of the arc tube 103.
Action and effect of the openings 1 11 will become apparent from the following description.

In this dielectric barrier lamp 100, the high frequency drive voltage is applied between the thin metal outer electrode 108 and the rod-shaped metal inner electrode 101 at the center. Since the external electrode 108 and the internal electrode 101 face each other, the high frequency drive voltage applied to the external electrode 108 causes discharge between the external electrode 108 and the internal electrode 101. At this time, it is well known that the wavelength of the emitted light changes depending on the kind of the rare gas interposed between the electrodes 108 and 101.

At this time, the external electrode 108 cannot maintain optimum light emission unless it is in close contact with the arc tube 103.
Further, the emitted light cannot be sufficiently radiated to the outside from the light emitting window unless the external electrode 108 has an appropriate aperture ratio. Therefore, in general, the external electrode 108 is spirally wound around the outer circumference of the arc tube 103 relatively sparsely so as to obtain a sufficient opening.

[0016] According to the dielectric barrier lamp 100 of the present invention, the inner surface of the casing 107, the groove 113 of the pitch can be fitted a band-shaped and spiral external electrode 108 is formed. The groove 113 allows the thin strip- shaped external electrodes 108 made of a highly conductive metal such as SUS (stainless steel), monel or aluminum to be pressed or adhered to the outer surface of the arc tube 103 at a constant pitch. In addition, the end portion of the external electrode 108 is fixed to the fixing plate 110 as described above.
It is fixed by. Only wound on the outer surface of the strip-like outer electrodes 108 simply emitting tube 103, vibration, shock,
There is a risk of displacement due to heat generation. However, according to the dielectric barrier lamp 100 of the present invention, the housing portion 10
The external electrode 108 can be reliably and stably fixed by the groove 113 and the protrusion 112 provided in the electrode 7. Moreover, the projection 112 is formed by the arc tube 103 and the casing 107.
It is possible to keep the strip- shaped external electrode 108 constant without damaging the thickness by processing it to a height that sets the interval between and. By appropriately selecting the pitch between the groove 113 and the protrusion 112, the external electrode 108
It is possible to determine the aperture ratio of.

Furthermore, the dielectric barrier lamp 1 of the present invention
According to 00, the strip-shaped metal plate forming the external electrodes 108, are formed a large number of openings 111 over its entire length. By using the external electrode 108 having such a specific shape, the aperture ratio is greatly increased, and the emitted light can be emitted to the outside extremely efficiently. The opening 111 of the external electrode 108 can be circular, rectangular, rhombic, or any other shape. By forming such an opening 111 in the external electrode 108, it becomes possible to realize a high aperture ratio of about 60% or more. The formation of such an opening 111 in the outer electrode 108 can be performed by well-known means including machining and chemical etching. Also,
Since both ends of the external electrode 108 are held by the electrode holding portions 105 and 106 made of a non-conductive material such as synthetic resin, there is no instability during operation.

As best shown in FIG. 4, the high frequency drive voltage is generated by the voltage generator 120 and applied between the inner electrode 101 and the outer electrode 108 of the dielectric barrier lamp 100. Since such a high frequency voltage generator 120 is well known,
The description is omitted here.

The configuration and operation of the preferred embodiment of the dielectric barrier lamp according to the present invention have been described above in detail. However, those skilled in the art can easily understand that the present invention should not be limited to only the specific embodiment and various modifications and changes can be made according to the specific application. For example, it goes without saying that the internal electrode may be a conductive coating applied to the inner wall of the arc tube instead of the metal rod-shaped electrode of this particular embodiment.

[0020]

As can be understood from the above description, the dielectric barrier lamp according to the present invention has an aperture ratio of, for example, 60%.
Since it can be made extremely high as described above, it is possible to radiate the emitted light such as ultraviolet rays to the outside of the arc tube with high efficiency. Further, since the external electrode is securely held on the outer surface of the arc tube by the groove and the projection of the casing, the remarkable practical effect that the light emission is extremely stable is obtained.

[Brief description of drawings]

1 is a longitudinal sectional view of a preferred embodiment of a dielectric barrier lamp according to the present invention,

2 is an end cross-sectional view of the dielectric barrier lamp of FIG. 1,

FIG. 3 is a sectional view of an intermediate portion of the dielectric barrier lamp shown in FIG.

FIG. 4 is an external view showing an operating state of the dielectric barrier lamp of FIG.

FIG. 5 is a vertical sectional view of a conventional dielectric barrier discharge lamp,

FIG. 6 is a cross-sectional view of a conventional dielectric barrier discharge lamp device.

[Explanation of symbols]

100 dielectric barrier lamp 101 internal electrode 102 terminal 103 arc tube 104 discharge space 105 Electrode holding member 106 Electrode holding member 107 housing 108 External electrode 110 External electrode fixing part 111 opening 112 Spiral protrusion 113 spiral groove

Continuation of the front page (56) References JP-A-8-153493 (JP, A) JP-A-10-284008 (JP, A) JP-A-7-14554 (JP, A) JP-A-7-14553 (JP , A) JP 6-310104 (JP, A) JP 6-84506 (JP, A) JP 62-12046 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) H01J 65/00

Claims (6)

(57) [Claims] 1. A dielectric barrier lamp having an internal electrode and an external electrode inside and outside a double-structured arc tube, wherein a rare gas is sealed in a discharge space of the arc tube. A housing portion is arranged on the outer surface, a spiral groove and a spiral protrusion are formed on the inner surface of the housing portion, and the external electrode arranged on the outer surface of the arc tube is held in the spiral groove. Characteristic dielectric barrier lamp. Wherein said external electrodes, a dielectric barrier lamp according to claim 1, characterized in that the thin metallic strip-shaped electrodes. 3. The dielectric barrier lamp according to claim 2, wherein a large number of small openings are formed in at least the light emitting portion of the external electrode. 4. The dielectric barrier lamp according to claim 1, wherein the internal electrode is a metal rod-shaped electrode inserted in a central hole of the arc tube. 5. Before Symbol inner electrode is longer than the arc tube,
The dielectric barrier lamp according to claim 4, wherein an electrode holder is disposed on at least one side of the arc tube to hold an end of the external electrode. 6. The end portion of the external electrode is attached to the housing portion.
The dielectric barrier lamp according to claim 1, wherein the dielectric barrier lamp is fixed to an attached electrode fixing plate, and a high frequency drive voltage is applied to the electrode fixing plate.