JPH0714553A - Dielectric barrier discharge lamp - Google Patents

Abstract

PURPOSE:To stabilize an electric discharge and improve luminous efficiency by arranging strands forming a conducting mesh electrode provided on a light transmitting dielectric substance to obliquely cross the axis of a discharge container. CONSTITUTION:A discharge container is made of quartz glass, and it is coaxially arranged with an inside tube 2 and an outside tube 3 into a hollow cylindrical shape. The outside tube 3 and the inside tube 2 concurrently serve as a dielectric barrier and a tip output window member dielectric barrier discharge, and light transmitting metal mesh electrodes 4, 5 are provided on the outer face. The mesh electrodes 4, 5 are bored with meshes 21 on metal plates, the residual portions 22a, 22b, 22c and 23a, 23b, 23... of the metal plates form strand groups of metal nets, and they obliquely cross each other respectively. No excess electric discharges occur between the outside tube 3 and the electrode 5 and between the inside tube 2 and the electrode 4, generation of harmful compounds around a lamp can be prevented, and the electric discharge is stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is, for example, a kind of discharge lamp used as an ultraviolet light source for photochemical reaction, which forms excimer molecules by dielectric barrier discharge and utilizes the light emitted from the excimer molecules. To improve the so-called dielectric barrier discharge lamp.

[0002]

2. Description of the Related Art As a technique related to the present invention, there is, for example, Japanese Patent Laid-Open Publication No. Hei 2-7353, in which a discharge vessel is filled with a discharge gas for forming excimer molecules, Barrier discharge (also known as ozonizer discharge or silent discharge. See the revised edition "Discharge Handbook" published by The Institute of Electrical Engineers of Japan, June 7, 1999, 7th edition, page 263) forms excimer molecules, and the light emitted from the excimer molecules is extracted. A radiator, i.e. a dielectric barrier discharge lamp, is described, wherein the discharge vessel is cylindrical, at least a portion of the discharge vessel also serving as the dielectric of the dielectric barrier discharge, at least the dielectric A part of the dielectric layer is transparent to light emitted from the excimer molecule, and an electrically conductive mesh electrode is provided on at least a part of the transparent dielectric body. Body structure barrier discharge lamp is described. The dielectric barrier discharge lamp as described above is useful because it has various features that conventional low-pressure mercury discharge lamps and high-pressure arc discharge lamps do not have. However, the above-mentioned dielectric barrier discharge lamp has a problem that the luminous efficiency is not always sufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cylindrical dielectric barrier discharge lamp with stable discharge and high luminous efficiency.

[0004]

An object of the present invention is to fill a discharge vessel having a substantially cylindrical outer shape with a discharge gas for forming excimer molecules by dielectric barrier discharge, and at least a part of the discharge vessel. Also serves as a dielectric of the dielectric barrier discharge, at least a part of the dielectric is light transmissive to light emitted from the excimer molecule, and at least a part of the light transmissive dielectric is In a dielectric barrier discharge lamp provided with a conductive reticulated electrode, it can be achieved by arranging at least one group of wires forming the conductive reticulated electrode so as to cross the axis of the discharge vessel at an angle. Further, the object of the present invention can be further achieved by using a structure in which the conductive mesh electrode is perforated in a single metal plate.

[0005]

[Function] Dielectric barrier discharge is described in the "Discharge Handbook"
As described in (1), it is a large collection of minute discharge plasmas (hereinafter referred to as microplasma) having a very small plasma diameter and a very short discharge duration. In a dielectric barrier discharge lamp having a structure in which a conductive mesh electrode is provided on a roughly cylindrical light-transmitting dielectric that is a light extraction window member, we have found that the stability of the light output, that is, the temporal fluctuation of the light output. , And luminous efficiency have been experimentally found to be affected by the small voids created between the conductive mesh electrode and the light transmissive dielectric. That is, in a dielectric barrier discharge lamp having a cylindrical outer shape, it is difficult to completely adhere the cylindrical light-transmitting dielectric and the conductive mesh electrode to each other, and therefore A void may occur between the transparent dielectric and a portion of the conductive mesh electrode. Then, extra discharge is generated in the minute gap. As a result, this extra discharge generates harmful compounds in the vicinity of the lamp, for example, nitrogen oxides and ozone are generated when the atmosphere is air, and the discharge becomes unstable, resulting in a light output. It has been found that there are problems such as instability and reduced luminous efficiency.

A discharge container having at least a substantially cylindrical outer shape is filled with a discharge gas for forming excimer molecules by dielectric barrier discharge, and at least a part of the discharge container also serves as a dielectric for the dielectric barrier discharge. And a dielectric barrier discharge in which at least a part of the dielectric is transparent to the light emitted from the excimer molecule, and a conductive mesh electrode is provided on at least a part of the transparent dielectric. In the lamp, at least one group of strands forming the conductive reticulated electrode is arranged so as to obliquely intersect the axis of the discharge container, and the conductive reticulated electrode is arranged in the discharge container in a state configured as described above. When pulled in the axial direction, the radius of the conductive mesh electrode contracts, so that there is no gap between the light transmissive dielectric and a part of the conductive mesh electrode, and as a result, an extra discharge occurs. No longer be generated. Therefore,
You can prevent the generation of harmful compounds around the lamp,
In addition, the discharge becomes stable and the luminous efficiency can be improved. Further, in the case of an ordinary net having a structure in which a plurality of groups of metal thin wires are woven, at the intersection of the metal thin wires, one group of metal thin wires is located on the other group of metal thin wires, so that the light transmissive dielectric In contrast to the gap between the body and the body, when the conductive reticulated electrode is perforated in a single metal plate, the wires that make up the net are on the same plane even at their intersections. Further, the gap between the light-transmissive dielectric and a part of the conductive reticulated electrode is further eliminated, and as a result, extra discharge is prevented from occurring, and the object of the present invention can be further achieved.

[0007]

1 is a schematic view of a coaxial cylindrical dielectric barrier discharge lamp according to a first embodiment of the present invention. Discharge vessel 1
Is made of quartz glass having a total length of about 300 mm, and an inner tube 2 having an outer diameter of 14 mm and an outer tube 3 having an inner diameter of about 25 mm are coaxially arranged to form a hollow cylinder. Outer tube 3 and inner tube 2
Serves as both a dielectric barrier for dielectric barrier discharge and a light extraction window member, and metal net-like electrodes 4 and 5 for transmitting light are provided on the outer surface thereof. The mesh electrodes 4 and 5 are shown in FIG.
As shown in a part thereof, a single metal plate is perforated, the metal plate is made of aluminum having a thickness of 0.2 mm, and diamond-shaped holes, that is, meshes 21 are perforated, and a remaining width of 0. 2 mm metal plate portions 22a, 22b, 22c, ...
.. and 23a, 23b, 23c, ... Form a wire group of a metal net, and intersect diagonally with each other.

The metal mesh is, as shown in FIG.
a, 22b, 22c, ... And 23a, 23b, 2
3c, ... The group of wires is the dielectric barrier discharge lamp 1
The outer tube 3 was wound on the outer side so as to cross the shafts 20a and 20b of the above, and was inserted into the inner tube 2 in a cylindrical shape. After mounting as described above, the electrode 5 wound around the outer tube 3 is pulled in the axial direction 20a, 20b of the lamp, and the electrode 4 inserted into the inner tube 2 is moved in the axial direction of the lamp. By compressing, each electrode was brought into close contact with the outer tube 3 and the inner tube 2 without any gap. A barium getter 6 is provided at one end of the discharge vessel 1. Further, the getter 6 is only fixed to the discharge vessel 1 by the protrusion 9 provided on the outer tube 3 and is not fixed to the discharge vessel 1. 300 tons of xenon gas was used as the discharge gas in the discharge space 7.
rr was enclosed. Discharging with a power of 8 watts at a frequency of 20 kHz at a power of 2 watts per cm of lamp, no extra discharges occurred between the outer tube 3 and the electrode 5 and between the inner tube 2 and the electrode 4, thus In addition, it was possible to prevent the generation of harmful compounds in the vicinity of the lamp, stabilize the discharge, radiate the ultraviolet rays at 172 nm and its vicinity with high efficiency, and improve the luminous efficiency by about 10%.

Further, even in the case of an ordinary net having a structure in which a plurality of groups of metal thin wires are woven, the same adhesive function due to the expansion and contraction function can be obtained, but at the intersection of the metal thin wires, one group of metal thin wires is Since it is located on the thin metal wire of the group of, a gap is created between the light-transmitting dielectric and
When the conductive reticulated electrode is perforated in a single metal plate, the wires forming the net are in the same plane even at the intersections thereof, so that the light transmissive dielectric and a part of the conductive reticulated electrode are formed. The voids are further eliminated from occurring, and as a result, extra discharge is not generated, and the object of the present invention can be achieved further.

In the second embodiment of the present invention, the electrode 4 in the first embodiment is a metal thin film electrode also serving as a light reflecting plate on which aluminum is vapor-deposited, and the electrode 5 has a diameter of 0.05.
A metal net in which 50 mm mesh stainless steel wires are orthogonally woven is arranged so that each element wire obliquely intersects the axis of the lamp. Also in this embodiment, the outer tube 3
Excessive discharge is less likely to occur between the electrode 5 and the electrode 5, so that the generation of harmful compounds in the vicinity of the lamp is reduced and the discharge is stabilized, and the ultraviolet rays at 172 nm and its vicinity are highly efficient. The emission efficiency was improved.

[0011]

As described above, according to the present invention, a highly efficient dielectric barrier discharge lamp can be provided.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of a dielectric barrier discharge lamp of the present invention.

FIG. 2 is an illustration of an example of an electrode.

[Explanation of symbols]

 1 Discharge container 2 Inner tube 3 Outer tube 4,5 Electrode 7 Discharge space 8 Power supply

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Onishi 1194 Sato, Bessho Town, Himeji City, Hyogo Prefecture Ushio Electric Co., Ltd.

Claims (2)

[Claims] 1. A discharge vessel having a substantially cylindrical outer shape is filled with a discharge gas that forms excimer molecules by dielectric barrier discharge, and at least a part of the discharge vessel also serves as a dielectric of the dielectric barrier discharge. At least a part of the dielectric is transparent to light emitted from the excimer molecule, and a dielectric barrier in which a conductive mesh electrode is provided on at least a part of the transparent dielectric. In a discharge lamp, at least one group of strands forming the conductive mesh electrode intersects the axis of the discharge vessel at an angle, and a dielectric barrier discharge lamp. 2. The dielectric barrier discharge lamp according to claim 1, wherein the conductive mesh electrode is made of a perforated metal plate.