JPH0778592A - Dielectric barrier discharge lamp - Google Patents

Abstract

PURPOSE:To provide a dielectric barrier discharge lamp easy to retain a lamp and presenting a good light takeout efficiency by furnishing lamp base, which has a smaller outside diameter than a conductive mesh-form electrode and is equipped with a vent for cooling, at least at one end of a discharge vessel. CONSTITUTION:An inner tube 2 and outer tube 3 are coaxially installed in a discharge vessel 1 made of crystal glass, wherein the outer tube 3 is equipped at its outer surface with a mesh-form electrode 4 made of metal while the inner tube 2 is fitted with an Al electrode 5 on the outside surface, and a protection film 20 made from silicone rubber is installed to protect the Al electrode 5. At the ends of the discharge vessel 1, lamp bases 10, 11 are furnished made from silicone rubber, of smaller outside diameter than the mesh-form electrode 4, and having vents 12, 13. Xe gas is encapsulated in a discharge space 7 formed in this discharge vessel 1, and a current having a frequency of 20kHz is fed from a power supply 8 to actuate electric discharge, and ultraviolet rays of 172nm and its neighboring range are emitted in a high efficiency. Owing to silicone rubber adopted to the material of the lamp bases, cooling is possible to allow easy mounting on the vessel 1, and a good endurance is provided even for ultraviolet rays.

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. 2-7353, in which a discharge vessel is filled with a discharge gas for forming excimer molecules, and a dielectric is used. 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 2001, Reprint 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 barrier discharge lamp structure is described. The dielectric barrier discharge lamp as described above,
It is useful because it has various features that conventional low-pressure mercury discharge lamps and high-pressure arc discharge lamps do not have. But,
The dielectric barrier discharge lamp as described above has a problem that the method for holding the lamp has not been sufficiently examined, although it has a completely different structure from the conventional lamp.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a dielectric barrier discharge lamp which has a sufficient light extraction efficiency and is easy to hold.

[0004]

An object of the present invention is to fill a discharge vessel having at least a substantially cylindrical outer shape with a discharge gas that forms excimer molecules by dielectric barrier discharge, and to form an outer wall of the discharge vessel. At least a part thereof is transparent to the light emitted from the excimer molecule, and also serves as a dielectric of the dielectric barrier discharge, and at least a part of the transparent dielectric is conductive. This is achieved by providing a dielectric barrier discharge lamp provided with a mesh electrode with a structure in which at least one end of the discharge vessel is provided with a base having an outer diameter equal to or smaller than the outer diameter of the conductive mesh electrode.
Further, the object of the present invention is further achieved by configuring the base so as to have a ventilation hole for cooling the lamp.

[0005]

The inventors of the present invention have found that at least a part of the outer wall of the discharge vessel is filled with a discharge gas that forms excimer molecules by a dielectric barrier discharge in a discharge vessel having at least a substantially outer shape. A dielectric that is transparent to the light emitted from the molecule and that also serves as the dielectric of the dielectric barrier discharge, in which a conductive mesh electrode is provided on at least a part of the transparent dielectric. In the body barrier discharge lamp, the light extraction efficiency was examined in detail, and it was found that the light extraction efficiency was determined by the method of holding the dielectric barrier discharge lamp, in particular, the cap provided at the end of the dielectric barrier discharge lamp. It was discovered that it is greatly affected by the structure of. That is, it was discovered that when the outer diameter of the die exceeds the outer diameter of the conductive reticulated electrode, the light extraction efficiency decreases.
Furthermore, we have found that this cause is due to the light distribution unique to the cylindrical dielectric barrier discharge lamp. FIG. 2 is an explanatory view of the light distribution, in which the light distribution of a straight-tube fluorescent lamp or a halogen lamp is in a direction perpendicular to the tube axis of the lamp.
That is, while θ is a circular curve 21 whose diameter is the light output in the direction of π / 2, the light distribution of the dielectric barrier discharge lamp is closer to 0 and π than the circular distribution. The distribution 22 is such that the light output is increased. That is, in the dielectric barrier discharge lamp, the proportion of light emitted in the direction close to the tube axis is larger than that in a fluorescent lamp, and therefore the outer diameter of the base is smaller than the outer diameter of the conductive mesh electrode. If it exceeds, the light extraction efficiency decreases. That is, it is a phenomenon peculiar to the cylindrical dielectric barrier discharge lamp that the light output, in other words, the light extraction efficiency is lowered due to the structure of the base.

At least a part of the outer wall of the discharge vessel is filled with a discharge gas that forms excimer molecules by a dielectric barrier discharge in a discharge vessel having at least a substantially cylindrical outer shape, and light emitted from the excimer molecules. In the dielectric barrier discharge lamp, which is light transmissive to, and also serves as a dielectric of the dielectric barrier discharge, and in which at least a part of the light transmissive dielectric is provided with a conductive mesh electrode,
Providing at least one end of the discharge container with a base having an outer diameter equal to or less than the outer diameter of the conductive reticulated electrode, first of all without decreasing the light extraction efficiency, secondly thick, and
The position of the lamp can be set easily and precisely as compared with the case where the end of a coaxial cylinder having a complicated structure is directly supported. Incidentally, the base in the present invention is a structure for the purpose of holding the lamp independent of the discharge vessel of the dielectric barrier discharge lamp, which is fixed to the discharge vessel by adhesion with an adhesive or by press fitting. Say. Further, the outer diameter of the conductive reticulated electrode in the present invention is the outer diameter of the reticulated electrode measured in the state of being mounted in the discharge vessel. For example, the outer diameter of the conductive reticulated electrode when a cylindrical net having diameters of dmm crossed with each other is attached to a discharge vessel having a diameter of Dmm is 4 times d and D due to the "overlap" of the wires.
Is the sum of

If the base has a structure having a vent hole for cooling the lamp, the lamp can be easily cooled, and a high output dielectric barrier discharge lamp can be easily obtained. When the base is made of silicone rubber or fluororesin, the material is elastic, and therefore, there are advantages that the base is easy to attach to the end of the discharge vessel and the lead wire connected to the electrode is easy to take out.

[0008]

1 is a schematic view of a coaxial cylindrical dielectric barrier discharge lamp according to an embodiment of the present invention. The discharge vessel 1 is made of quartz glass having a total length of about 150 mm, and an inner tube 2 having an outer diameter of 14 mm and an outer tube 3 having a wall thickness of 1 mm and an inner diameter of about 25 mm are coaxially arranged to form a hollow cylinder. The outer tube 3 also serves as a dielectric barrier for a dielectric barrier discharge and a light extraction window, and a metal mesh electrode 4 that transmits light is provided on the outer surface. An aluminum electrode 5 also serving as a light reflection plate is provided on the outer surface of the inner tube 2. Reference numeral 20 is a protective film made of an addition type silicone rubber provided for the purpose of mechanically and chemically protecting the aluminum electrode 5. A barium getter 6 is provided at one end of the discharge vessel 1. The mesh electrode 4 is a seamlessly knitted cylindrical mesh that is elastic in the axial direction. The discharge vessel 1 is inserted into the cylindrical metal mesh,
By pulling in the axial direction of the lamp, a mesh electrode 5 is formed in close contact with the outside of the outer tube 3. Therefore, the outer diameter of the cylindrical mesh electrode is about 27.4 mm. Both ends of the discharge vessel are made of silicone rubber and have an outer diameter of 24 mm,
The bases 10 and 11 having the ventilation holes 12 and 13 were attached using a silicone rubber adhesive. The adhesive is not shown.

The discharge space 7 of the discharge vessel was filled with 300 Torr of xenon gas as a discharge gas. When the electric power was discharged from the power source 8 having a frequency of 20 kHz at a power of 2 watts per 1 cm of the lamp length, the ultraviolet rays at 172 nm and its vicinity were radiated with high efficiency. Since the base has an outer diameter smaller than the outer diameter of the conductive reticulated electrode, it directly supports the end of a coaxial cylinder having a thick and complicated structure without lowering the light extraction efficiency. It was possible to easily and precisely set the position of the lamp compared to. Further, by flowing nitrogen gas into the vent hole provided in the base to cool the lamp, a high output dielectric barrier discharge lamp which does not decrease in efficiency even when the lamp is lit with the electric input of 3 times as above was obtained. . Further, since the material of the base is silicon rubber, it has elasticity and can be easily attached to the discharge vessel.
Since it has sufficient resistance to ultraviolet rays in the wavelength region of nm and its vicinity, it has an advantage of having a sufficient life.

Even if a fluororesin base was used instead of silicon rubber, the same effect as in the above-mentioned embodiment was obtained. Moreover, it is obvious that the use of a ceramic or metal base does not lower the light extraction efficiency and can easily and precisely set the position of the lamp. .

[0011]

As described above, according to the present invention, it is possible to provide a dielectric barrier discharge lamp having sufficient light extraction efficiency and easy lamp holding.

[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 explanatory diagram of a light distribution distribution.

[Explanation of symbols]

 1 Discharge container 2 Inner tube 3 Outer tube 4 Cylindrical mesh electrode 5 Aluminum electrode 6 Getter 8 Power supply 10,11 Base 12,13 Vent hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumitoshi Takemoto 1194 Sado, Bessho Town, Himeji City, Hyogo Prefecture Ushio Electric Co., Ltd.

Claims (3)

[Claims] 1. A discharge vessel having 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 an outer wall of the discharge vessel is formed.
Is transparent to the light emitted from the excimer molecule, and also serves as the dielectric of the dielectric barrier discharge,
In a dielectric barrier discharge lamp in which a conductive mesh electrode is provided on at least a part of the light-transmitting dielectric, a base having an outer diameter equal to or smaller than the outer diameter of the conductive mesh electrode is provided on at least one end of the discharge vessel. Dielectric barrier discharge lamp characterized by 2. The dielectric barrier discharge lamp according to claim 1, wherein the base has a vent hole for cooling the lamp. 3. The dielectric barrier discharge lamp according to claim 1, wherein the base is silicon rubber or fluororesin.