JPH06310105A - Dielectric barrier discharge lamp - Google Patents

Abstract

PURPOSE:To provide a sheet-like dielectric barrier discharge lamp having a stable light output, high light emitting efficiency and a sufficient lifetime characteristic, where the light output cannot be reduced even after a lapse of lighting time. CONSTITUTION:A sheet-like dielectric barrier discharge lamp comprises sheet- like dielectrics 1, 2 for dielectric barrier discharge, a pair of electrodes 4 for dielectric barrier discharge, and a reinforcing member 5 consisting of a dielectric disposed in a discharge space in order to reinforce the dielectrics. One of the electrodes is provided on the outer surface of the dielectric except for an outer region opposite to the dielectric in contact with the reinforcing member 5.

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. 1-144560.
The discharge vessel is filled with a discharge gas that forms excimer molecules, and a dielectric barrier discharge (also known as ozonizer discharge or silent discharge. Revised new edition "Discharge Handbook" published by the Institute of Electrical Engineers of Japan, June 1st, 7th edition, Issue 263) (See page) to form excimer molecules and extract the light emitted from the excimer molecules, ie a dielectric barrier discharge lamp. It also describes a flat dielectric barrier discharge lamp with spacers. The flat dielectric barrier discharge lamp as described above is useful because it has various features which are not present in the conventional low pressure mercury discharge lamp or high pressure arc discharge lamp.
In order to mechanically reinforce the flat discharge vessel, it is necessary to provide a reinforcing member in the discharge space or in the vicinity of the discharge space.
This is a known technique in plasma display panels and the like. However, the flat-plate-shaped dielectric barrier discharge lamp with the reinforcing member provided in the discharge space as described above has unstable light output, the luminous efficiency is not always sufficient, and the light output is increased as the lighting time elapses. However, there is a problem that the life characteristics are not always sufficient.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention An object of the present invention is to provide a flat plate-shaped dielectric barrier having stable light output, high luminous efficiency, light output which does not decrease with the passage of lighting time, and which has sufficient life characteristics. It is to provide a discharge lamp.

[0004]

A flat plate dielectric for dielectric barrier discharge, and a pair of electrodes for dielectric barrier discharge,
In a flat plate dielectric barrier discharge lamp having a reinforcing member made of a dielectric material provided in a discharge space for reinforcing the dielectric material, except for an outer surface area opposite to the dielectric material with which the reinforcing member is in contact, One electrode is provided on the outer surface of the dielectric.

Specifically, for example, a flat plate-shaped first dielectric material and a second dielectric material that define the discharge space, and the first and second dielectric materials are provided in the discharge space to reinforce the discharge space. Electrodes are provided on the outer surfaces of the first and second dielectrics, respectively, except for the reinforcing member made of a dielectric material and the opposite outer surface areas of the opposing first and / or second dielectrics of the reinforcing member. At least one set of the dielectric and the electrode is provided so as to transmit light.

Alternatively, for example, the discharge space is defined,
From a flat plate-shaped dielectric that also serves as the light extraction window, a flat plate-shaped metal member that also defines the discharge space, and that also serves as the other electrode, and a dielectric provided in the discharge space to reinforce the dielectric. The outer surface of the dielectric member is provided with one electrode that transmits light, except for the reinforcing member and the outer surface area of the reinforcing member that is opposite to the opposing dielectric member.

More specifically, the distance between the boundary of the electrode and the boundary of the opposite outer surface area of the opposing dielectric of the reinforcing member is
It may be specified in the range of 1 to 15 times the thickness of the dielectric. And as for the reinforcing member, one end of the reinforcing member is a fixed end fixed to the first or second dielectric, and the other end is a free end that is not fixed, or One end of the reinforcing member may be a fixed end fixed to the dielectric or the other electrode, and the other end may be a free end not fixed.

[0008]

In the flat plate dielectric barrier discharge lamp having the reinforcing member in the discharge space, the discharge stability, that is, the stability of the light output, the luminous efficiency, and the life are determined by the constitution of the reinforcing member, the reinforcing member. It was discovered that it is greatly affected by the relative positional relationship between the and electrodes. That is, as shown in FIG. 2, a dielectric plate 1 for dielectric barrier discharge,
2 and an electrode 4 for dielectric barrier discharge which also functions as a light reflection plate
In a flat plate dielectric barrier discharge lamp having a light-transmissive metal mesh electrode 3 and a reinforcing member 5 made of a dielectric material provided in a discharge space to reinforce the dielectric material, electrodes 3, 4
When a high AC voltage is applied between the two, a uniform dielectric barrier discharge is generated in the discharge space 6 without the reinforcing member 5, whereas a creeping discharge 7 is generated along the reinforcing member 5. , The discharge generated in the discharge space 6 is very weak, and therefore the luminous efficiency is reduced. Further, the plasma 7 generated by the creeping discharge moves to the discharge space 6 and moves around irregularly, so that the light output is also unstable. The above-mentioned decrease in luminous efficiency and instability of light output associated with creeping discharge are peculiar phenomena of a flat plate dielectric barrier discharge lamp having a reinforcing member 5 made of a dielectric material, and they are a conventional phenomenon of a plasma display panel or a flat plate. This is a phenomenon that cannot be seen in fluorescent lamps.

As shown in FIG. 3, the inventors of the present invention have installed the electrodes, for example, the electrodes 4 provided on the surface (outer surface) of the flat plate-shaped dielectrics 1 and 2 opposite to the discharge space 6 to the flat plate-shaped dielectrics. 2 and the contact portion 22 of the reinforcing member 5 are configured so as to avoid the outer surface area 20 projected on the surface opposite to the discharge space of the flat plate-shaped dielectric body 4, that is, the discharge path of the reinforcing member 5 to the electrode 4. When a hole 21 having a cross-sectional area perpendicular to the reinforcing member 5 is provided and the electrode 4 is arranged so that the hole 21 is coaxial with the reinforcing member 5, the creeping discharge plasma 7 along the reinforcing member 5 is not generated and the discharge space 6 is formed. It has been found that uniform discharge occurs and the discharge is stable, so that reduction of luminous efficiency and instability of light output can be improved. A hole 21 is provided in the electrode 3 so as to avoid the outer surface area 20 in which the contact portion 22 of the flat plate-shaped dielectric 2 and the reinforcing member 5 is projected on the surface opposite to the discharge space of the flat plate-shaped dielectric 4. Or both electrodes 3 and 4 may be provided.

Contact portion 2 of the reinforcing member 5 along the discharge path
2 is mechanically fixed to the dielectric 2 by welding or an inorganic adhesive and the other end 23 is mechanically free even if it is in contact with the dielectric 1, the other end of the reinforcing member 5 Since the contact between 23 and the dielectric 1 is insufficient, creeping discharge is less likely to occur. Further, there is an advantage that manufacturing becomes easy. Further, when the flat plate-shaped dielectric 1 is also used as a light extraction window and the free end 23 of the reinforcing member 5 is arranged on the side of the light extraction window, the dielectric barrier discharge is generated even in the vicinity of the free end 23. Occurs, and therefore uniform light emission is obtained. Further, since the light extraction window is not contaminated due to the work of mechanically fixing the reinforcing member 5, there is an advantage that the transmittance of the light extraction window does not decrease.

An electrode 4 provided on the surface (outer surface) opposite to the discharge space 6 of the flat plate-shaped dielectric body 2 having one end fixed along the discharge path of the reinforcement member 5 is provided with the flat plate-shaped dielectric body 2 and the reinforcing member. The contact portion 22 of the plate-shaped dielectric 2 is arranged so as to avoid the outer surface area 20 projected on the surface opposite to the discharge space of the plate-shaped dielectric 2, and the plate-shaped dielectric 1 near the free end 23 of the reinforcing member 5. The electrode 3 provided on the surface (outer surface) opposite to the discharge space 6 is provided on the surface (outer surface) of the flat plate dielectric 1 close to the reinforcing member 5 on the opposite side of the discharge space 6. Projected outer surface area 24
If it is configured so as to avoid, the discharge will be more uniform, and the effect of suppressing creeping discharge will be even greater.

As shown in FIG. 4, the reinforcing member 5 is projected on the surface (outer surface) of the flat plate-shaped dielectric 2 opposite to the discharge space 6.
If the shortest distance a from the boundary 25 of the outer surface area 20 perpendicular to the discharge path to the boundary 26 of the electrode 4 is set to be 1 time or more the thickness b of the dielectric body 2, the occurrence of creeping discharge can be suppressed. Normal dielectric barrier discharge is also generated in the vicinity of the reinforcing member 5, so that a uniform light output can be obtained. That is, the shortest distance from the contour 25 of the cross-sectional portion perpendicular to the discharge path of the reinforcing member 5 projected on the surface (outer surface) opposite to the discharge space 6 of the flat dielectric 2 to the electrode 4 is the dielectric 2 By configuring the thickness to be in the range of 1 to 15 times the thickness, it is possible to obtain a dielectric barrier discharge lamp in which the occurrence of creeping discharge can be suppressed and the light output is spatially uniform.

[0013]

1 is a schematic view of a disk type dielectric barrier discharge lamp according to a first embodiment of the present invention. Diameter 100m
A disk-shaped discharge vessel 9 is formed by the flat plate-shaped dielectric bodies 1 and 2 made of synthetic quartz glass plate having a thickness of m and a thickness of 1.5 mm and the cylindrical quartz glass 8. The flat plate-shaped dielectric 1 also serves as a dielectric for a dielectric barrier discharge and a light extraction window, and has a metal mesh of a structure in which stainless steel wires having a diameter of 0.1 mm are knitted at 1 mm intervals orthogonally on the outer surface thereof. An electrode 3 is provided. Reinforcing member 5 made of synthetic quartz glass rod with a diameter of 2 mm
Is welded to the center 2a of the flat dielectric 2. The portion 5a of the reinforcing member 5 facing the flat plate-shaped dielectric 1 is only in contact with the flat plate-shaped dielectric 1 and is not mechanically fixed to the flat plate-shaped dielectric 1. On the outer surface of the flat plate-shaped dielectric body 2, an electrode 4 made of aluminum having a diameter of 10 mm and having a hole 4a in the center thereof is provided, which also serves as a light reflecting plate. Therefore, the boundary between the electrode 4 and the boundary of the opposing outer surface area of the dielectric member 2 of the reinforcing member facing each other is 4 mm. As a discharge gas, 350 Torr of xenon gas was filled in, and electrodes 3 and 4 were used.
When an AC voltage is applied between the electrodes, a uniform and stable dielectric barrier discharge is generated in the discharge space 6 without generating a creeping discharge, and ultraviolet rays having a maximum value at 172 nm and its vicinity are efficiently radiated, A dielectric barrier discharge lamp having good life characteristics was obtained because the discharge became non-uniform and was not concentrated locally.

In the second embodiment of the present invention, the electrode 4 in the first embodiment has no hole, and the metal mesh electrode 3 has a structure in which stainless steel wires having a diameter of 0.1 mm are knitted orthogonally at 6 mm intervals. The metal mesh electrode 3 was attached to the dielectric 1 so that the reinforcing member 5 was located at the center of the mesh of the metal mesh electrode 3. Also in this embodiment, a uniform and stable dielectric barrier discharge is generated in the discharge space 6 without generating the creeping discharge, and the ultraviolet rays having the maximum value at 172 nm and its vicinity are efficiently radiated, and the discharge is locally discharged. A dielectric barrier discharge lamp with good life characteristics was obtained because it was not concentrated in

A disk-shaped dielectric barrier discharge lamp according to the third embodiment of the present invention is shown in FIGS. The plate-shaped dielectric 51, the reinforcing member 52, and the side surface cylinder 53 are integrally formed of alumina, and the dielectric 1 made of sapphire and also serving as the light extraction window is hermetically sealed by the sealing glass. The reinforcing member 52 is not bonded to the dielectric 1 made of sapphire and also serving as the light extraction window. As shown in FIG. 5, the metal mesh electrode 3 provided on the dielectric 1 has a widened central portion, and the mesh wire is a projected portion of the cross section of the reinforcing member 52 perpendicular to the discharge path, that is, the outer surface area 55. It is installed so that it does not intersect with. In addition to the advantage that the ultraviolet radiation is efficiently radiated and the discharge is not locally concentrated, the life characteristics are also good, and in the present embodiment, since the reinforcing member is provided, the expensive sapphire disk can be made thin, so that the cost can be reduced. . Since the center portion of the sapphire disk is not bonded, there are advantages such as less cracking of sapphire due to the difference in thermal expansion coefficient between sapphire and alumina.

FIG. 7 is a schematic view of a disk-shaped dielectric barrier discharge lamp according to the fourth embodiment of the present invention. Diameter 100m
A disk-shaped discharge container 9 is formed by a flat plate-shaped dielectric 1 made of a synthetic quartz glass plate having a thickness of 1.5 mm and a thickness of 1.5 mm, an electrode 70 made of a nickel alloy disk, and a cylindrical quartz glass 8. The flat plate-shaped dielectric 1 also serves as a dielectric for a dielectric barrier discharge and a light extraction window, and a metal net having a structure in which stainless steel wires having a diameter of 0.1 mm are knitted at 2 mm intervals orthogonally on the outer surface thereof. The electrode 3 is provided in the same configuration as in FIG. 5 so as to avoid the reinforcing member 5. The reinforcing member 5 made of a synthetic quartz glass rod having a diameter of 2 mm is bonded to the electrode 70. The portion 5a of the reinforcing member 5 facing the flat plate-shaped dielectric 1 is only in contact with the flat plate-shaped dielectric 1 and is not mechanically fixed to the flat plate-shaped dielectric 1. Aluminum for reflecting ultraviolet rays is vapor-deposited on the inner surface of the electrode 70. The electrode 70 and the cylindrical quartz glass 8 are hermetically sealed using an alloy of titanium and indium. Even if the lamp is turned on, the temperature of the container does not rise so much, so there is no risk of cracks. 450T as discharge gas
When a xenon gas of orr was filled and an AC voltage was applied between the electrodes 3 and 4, a uniform and stable dielectric barrier discharge was generated in the discharge space 6 without generating a creeping discharge.
Ultraviolet rays having a maximum value of 72 nm and its vicinity are efficiently radiated, and the discharge is unstable, and the dielectric barrier discharge lamp having good life characteristics is obtained because it is not locally concentrated.

[0017]

As described above, according to the present invention, a dielectric having a stable light output, a high efficiency, a light output which does not decrease with the passage of lighting time, and a sufficient life characteristic. A barrier discharge lamp can be provided.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment lamp of the present invention.

FIG. 2 is an explanatory diagram of creeping discharge.

FIG. 3 is an explanatory diagram of prevention of creeping discharge.

FIG. 4 is an explanatory diagram of prevention of creeping discharge.

FIG. 5 is an explanatory diagram of how to provide a metal net electrode.

FIG. 6 is an explanatory view of a lamp according to another embodiment of the present invention.

FIG. 7 is an explanatory view of a lamp according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat dielectric 2 Flat dielectric 3 Metal mesh electrode 4 Electrode 5 Reinforcing member 6 Discharge space 7 Plasma 8 Quartz glass 9 Discharge container

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

Claims (6)

[Claims] 1. A flat plate dielectric for dielectric barrier discharge, a pair of electrodes for dielectric barrier discharge, and a reinforcing member made of a dielectric provided in a discharge space to reinforce the dielectric. In a flat plate dielectric barrier discharge lamp, one electrode is provided on the outer surface of the dielectric except for the outer surface area opposite to the dielectric with which the reinforcing member is in contact. lamp. 2. A reinforcing member comprising a flat plate-shaped first dielectric member and a second dielectric member defining a discharge space, and a dielectric member provided in the discharge space to reinforce the first and second dielectric members. An electrode on each of the outer surfaces of the first and second dielectrics, except for the member and the opposing outer surface areas of the opposing first and / or second dielectrics of the reinforcing member, A dielectric barrier discharge lamp, wherein one set of a dielectric and an electrode transmits light. 3. A flat plate-shaped dielectric that also serves as a light extraction window and defines the discharge space, and also defines the discharge space.
A flat metal member also serving as the other electrode, a reinforcing member made of a dielectric provided in the discharge space to reinforce the dielectric, and an outer surface area of the reinforcing member opposite to the opposing dielectric are provided. Except for the above, the dielectric barrier discharge lamp is characterized in that one electrode that transmits light is provided on the outer surface of the dielectric. 4. The distance between the boundary of the outer surface area of the reinforcing member, which is opposite to the facing dielectric, and the boundary of the electrode is defined to be in the range of 1 to 15 times the thickness of the dielectric. The dielectric barrier discharge lamp according to claim 1, wherein the dielectric barrier discharge lamp is a discharge lamp. 5. The reinforcing member according to claim 1, wherein one end of the reinforcing member is a fixed end fixed to the first or second dielectric and the other end is a free end not fixed. Two
A dielectric barrier discharge lamp as described. 6. The reinforcing member according to claim 3, wherein one end of the reinforcing member is a fixed end fixed to the dielectric or the other electrode, and the other end is a free end that is not fixed.
A dielectric barrier discharge lamp as described.