JP3178237B2 - Dielectric barrier discharge 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 kind of discharge lamp used as, for example, an ultraviolet light source for a photochemical reaction, in which excimer molecules are formed by dielectric barrier discharge and light emitted from the excimer molecules is used. 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.
There, a discharge vessel is filled with a discharge gas for forming excimer molecules, and a dielectric barrier discharge (also known as an ozonizer discharge or a silent discharge) is issued. (See page 263)
A lamp using light emitted from the excimer molecule, i.e., a dielectric barrier discharge lamp, wherein the discharge vessel is cylindrical and at least a part of the discharge vessel is A dielectric barrier discharge lamp is described, which also serves as a dielectric for a dielectric barrier discharge, the dielectric being light transmissive, and a conductive mesh electrode provided on at least a part of the dielectric. Further, a dielectric barrier discharge lamp having a configuration in which an electrode for dielectric barrier discharge is a metal and the metal electrode is in contact with a discharge gas is described in US Pat. No. 5,173,638. The dielectric barrier discharge lamp as described above,
It is useful because it has various features not found in conventional glow discharge lamps and arc discharge lamps. However, the dielectric barrier discharge lamp as described above is not necessarily compact in shape, and if the shape is compact, the power output to the lamp becomes insufficient due to insufficient power injected into the lamp, or the discharge becomes insufficient. There is a problem that the light output becomes unstable due to instability.

[0003]

It is an object of the present invention to provide a dielectric barrier discharge lamp which is compact, has a sufficiently high light output and is stable.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide at least a light-transmitting, elongated tubular discharge vessel serving also as a dielectric for a dielectric barrier discharge, and at least a part of the outer surface of the discharge vessel. A light-transmitting outer electrode for performing a dielectric barrier discharge provided in the discharge vessel,
Excimer molecules formed by an elongated inner electrode having a ratio L / D of a length L to an outer diameter D of 30 or more, particularly 80 or more, and the dielectric barrier discharge filled between the first dielectric and the inner electrode. Is formed as a generally tubular dielectric barrier discharge lamp composed of a discharge gas, and in particular, the inner electrode is formed of an elongated metal round bar or an elongated metal tube, and the inner electrode is in contact with the discharge gas. Achieved by configuration.

[0005] In addition, a getter is attached to the inner electrode, and one end of the elongated metal rod or the elongated metal tube is air-tightly attached to one end of the discharge vessel and drawn out of the discharge vessel. Is configured to be in the discharge vessel, the other end of the elongated metal rod or the elongated metal tube is fixed to the other end of the discharge vessel, or the elongated metal rod or the elongated The other end of the metal tube is loosely held at the other end of the discharge vessel, and a member that loosely holds the other end of the elongated metal rod or the elongated metal tube at the other end of the discharge vessel is provided. The object of the present invention is further achieved by using a structure that also serves as the rest of the exhaust pipe of the dielectric barrier discharge lamp.

Further, the dielectric barrier discharge lamp may be an aperture type lamp having a slit-like portion for taking out light provided on a part of an outer peripheral surface of the discharge vessel along a longitudinal direction. The outer surface of the light extraction portion is provided with a member that is electrically connected to the outer electrode and is light-transmissive. The outer electrode is installed on a part of the outer surface of the discharge vessel, and the light The extraction part is located on the opposite side of the outer electrode, and the inner electrode is provided closer to the light extraction part than the central axis of the discharge vessel. It was set on a part of the outer surface of the vessel, the light extraction portion was located on the opposite side of the outer electrode, and the inner electrode was provided farther from the light extraction portion than the central axis of the discharge vessel. Book by The purpose of the light is even more accomplished.

[0007] The discharge vessel is a cylinder, the inner electrode is a round bar or a tubular metal, and the inner diameter of the discharge vessel is in the range of 3 to 40 times the outer diameter of the inner electrode. The outer electrode is provided over the entire outer surface of the discharge vessel, and the distance between the central axis of the inner electrode and the central axis of the discharge vessel is set to be larger than the outer diameter of the inner electrode. In addition, the object of the present invention is further achieved by forming the outer electrode with a seamless cylindrical wire mesh.

[0008]

[Function] A high-intensity ultraviolet light source is required for the ultraviolet curing of paint and the dry cleaning of metal surfaces using ultraviolet light. Compactness is required in order to obtain high brightness by increasing the size or to make the entire device compact. That is, it is required that the outer diameter is small and the ratio of the total length to the effective emission length is small. However, it is difficult to make the shape of the conventional dielectric barrier discharge lamp compact, and even if the lamp is made compact, the power output to the lamp becomes insufficient due to insufficient power injection into the lamp. Alternatively, there has been a problem that the discharge becomes unstable and the light output becomes unstable.

FIG. 12 is a schematic diagram of a conventional dielectric barrier discharge lamp, and the above problem will be described. The discharge vessel 1 is made of glass, and has a hollow cylindrical shape in which an inner tube 22 and an outer tube 23 are coaxially arranged. On the outer surface of the outer tube 23, an electrode 24 for light-transmitting dielectric barrier discharge is provided.
On the outer surface of the inner tube 22, electrodes 25 for dielectric barrier discharge which also serve as a light reflection film formed by vapor deposition of aluminum are provided. At one end of the discharge vessel, a getter chamber 26 for accommodating a getter 27 is provided. In order to mechanically and chemically protect the electrode 25 formed by vapor deposition of aluminum, a protective film 28 made of boron nitride is provided on the electrode 25. Dielectric barrier discharge is
As described in the "Discharge Handbook", a large number of small discharge plasmas (hereinafter referred to as microplasma) having a very small plasma diameter and a very short discharge duration. . In the discharge space 29,
A discharge gas for forming excimer molecules by dielectric barrier discharge is filled, and electrodes 24 and 25 are supplied by an AC power supply 21.
When a voltage is applied to the discharge space 29, a large number of microplasmas are stably generated in the discharge space 29, and excimer light is emitted. If a phosphor is applied to the inner surfaces of the inner tube and the outer tube, the phosphor is excited by excimer light and emits visible light.

However, as is apparent from FIG. 12, first of all, there are two dielectrics between the electrodes 24 and 25, that is, the inner tube 22 and the outer tube 23, and the protective film of the electrode 25. Since the lamps 28 are provided, it is extremely difficult to reduce the diameter of the lamp. Second, even if the diameter can be reduced, the surface area of the inner tube 22 facing the discharge space 29 is reduced, so that the amount of power injected into the discharge space 29 is reduced.
A disadvantage arises in that the light output is reduced. Third, since the getter cannot be fixed because there is no metal in the discharge vessel 1, a getter storage chamber for storing the getter needs to be provided separately from the discharge space, and the overall length of the lamp becomes longer. And the like.

Before explaining the principle of the present invention, first, an outline of a general dielectric barrier discharge will be described. In a normal arc discharge such as a medium pressure arc discharge lamp or a high pressure arc discharge lamp of several tens of torr or more, only one discharge plasma exists in a discharge space, and one small electrode luminescent spot is generated on an electrode surface. That is, even if the area of the electrode is increased, a portion that substantially functions as an electrode is a very small portion. On the other hand, as described in the discharge handbook, in the dielectric barrier discharge,
Since a dielectric is inserted into the discharge path, the dielectric prevents the discharge plasma from converging into a single line, so that there are multiple discharge plasmas in the discharge space, and a large number of electrodes are formed over a wide area of the electrode. Bright spots will be uniformly present. One of the reasons why excimer light is emitted with high efficiency in a dielectric barrier discharge lamp is the existence of the above-mentioned multiple discharge plasmas. The injection of power into the discharge space when a dielectric is inserted in the discharge path is roughly based on a voltage applied to the discharge space, that is, a discharge maintaining voltage,
It is approximately proportional to the ratio of the voltage drop in the dielectric, that is, the ratio of the impedance of the discharge plasma to the impedance of the dielectric. In a dielectric barrier discharge lamp having a configuration in which two dielectrics are present across the discharge space, the effect of preventing the discharge plasma from converging into a single line is large,
Although multiple discharge plasmas are stably present, a stable light output can be obtained.On the other hand, since there are two dielectrics, power is hardly injected into the discharge space, and as a result, the light output is sufficient. Disadvantageously cannot be obtained. In contrast, in a dielectric barrier discharge lamp having only one dielectric, that is, a dielectric barrier discharge lamp having a structure in which one electrode is in contact with a discharge gas, power can be easily injected into a discharge space. On the other hand, since the effect of preventing the discharge plasma from converging into a single line is small, the discharge is temporarily concentrated at one point on the metal electrode in contact with the discharge gas, and as a result, Disadvantages such as unstable discharge, unstable light output, and reduced radiation efficiency of excimer light occur.

[0012] The present inventors have at least considered that they are light-transmitting,
An elongated tubular, discharge vessel also serving as a first dielectric of the dielectric barrier discharge, and a light-transmissive outer electrode for performing a dielectric barrier discharge provided on at least a part of the outer surface of the discharge vessel; An elongated inner electrode located inside the discharge vessel,
In a substantially tubular dielectric barrier discharge lamp composed of a discharge gas forming excimer molecules by the dielectric barrier discharge filled in the discharge vessel, xenon gas or a mixed gas of chlorine and a rare gas is used as a discharge gas. The phenomenon of discharge plasma converging into a single line was examined by changing the shape of the inner electrode. as a result,
When the inner electrode is formed of an elongated metal round bar or an elongated metal circular tube, even if the inner electrode is in contact with the discharge gas,
It has been found that the phenomenon in which the discharge plasma converges in one line is unlikely to occur. The meaning of "elongated" here is that the ratio of the length of the part operating as a dielectric barrier discharge electrode of a metal round bar or metal tube to the average outer diameter is large,
In particular, when the ratio is 30 or more, particularly 80 or more, a phenomenon in which the discharge plasma converges in one line hardly occurs.

That is, at least a light-transmissive, elongated tubular discharge vessel serving also as a dielectric for the dielectric barrier discharge, and a dielectric barrier discharge provided on at least a part of the outer surface of the discharge vessel for performing the dielectric barrier discharge A substantially tubular dielectric comprising a light-transmissive outer electrode, an elongated inner electrode disposed inside the discharge vessel, and a discharge gas that forms excimer molecules by the dielectric barrier discharge filled in the discharge vessel. In the body barrier discharge lamp, if the inner electrode is formed of an elongated metal rod or an elongated metal tube and the inner electrode is configured to be in contact with the discharge gas, first, the phenomenon that the discharge plasma converges into a single line. And the fluctuation of light output is small. Secondly, the number of dielectrics inserted in the discharge path is reduced to one, and the protective film 28 is not required. Third, since the diameter can be easily realized, and thirdly, since the number of dielectrics is reduced to one, even when an elongated inner electrode having a small surface area is used, sufficient power can be injected into the discharge space, and thus the light output is sufficiently large. A compact dielectric barrier discharge lamp with high luminance and stable light output can be obtained.

Further, when combined with a condenser mirror, the ultraviolet light emitted from the lamp is reflected by the condenser mirror, but a part of the reflected ultraviolet light returns to the lamp, and After passing through, it is reflected by the condenser mirror again and emitted from the condenser system. When a thin metal rod or a long metal tube is used as the inner electrode as in the present invention, absorption of ultraviolet light by the inner electrode is small, and therefore, even when combined with a condenser mirror, a lamp with high luminous efficiency is obtained. I can do it.

When a getter is attached to the inner electrode, a compact lamp can be obtained because it is not necessary to separately provide a getter storage chamber or another member for attaching the getter.

When one end of the elongated metal rod or the elongated metal tube is air-tightly attached to one end of the discharge vessel and drawn out of the discharge vessel, and the other end is located inside the discharge vessel, Second, since the electrode lead wire is present only at one end, conversion can be achieved. Second, a high voltage is required to light the dielectric barrier discharge lamp, and the electrode lead wire to which a high voltage is applied is required. Although the above-mentioned safety measures are necessary, by setting the above-mentioned inner electrode to a higher voltage, insulation measures can be completed at one end, and a more compact dielectric barrier discharge lamp can be obtained.

When the other end of the elongated metal rod or the elongated metal tube is fixed to the other end of the discharge vessel, both ends of the metal electrode are supported, and the elongated metal electrode is placed in the elongated discharge vessel. It is possible to install the dielectric barrier discharge lamp with a good positional relationship, and to obtain a dielectric barrier discharge lamp with little variation. When the other end of the elongated metal rod or the elongated metal tube is loosely held at the other end of the discharge vessel, firstly, manufacture becomes easy, and secondly, as the elongated metal electrode, the heat of the discharge vessel is used. It is possible to use a metal having a coefficient of thermal expansion different from the coefficient of expansion, for example, it is possible to use a metal that is a getter material as an electrode,
There is an advantage that the degree of freedom of measures such as extension of life is increased. When the member for loosely holding the other end of the elongated metal rod or the elongated metal tube at the other end of the discharge vessel is also used as the rest of the exhaust pipe of the dielectric barrier discharge lamp, the production is further facilitated and the cost is reduced. This has the advantage of becoming

A light reflecting film is provided on a part of the outer surface of the discharge vessel,
An aperture-type lamp having a configuration in which a light-reflecting film is not provided remains in a slit shape in the longitudinal direction of the container and takes out light in a slit shape. It has the advantage that it is more compact and can obtain high brightness. However, although an aperture-type lamp has been realized in a fluorescent lamp, an aperture-type lamp has not been realized in a conventional ultraviolet lamp using low-pressure mercury discharge or high-pressure arc discharge. The reason is that since the ultraviolet light is absorbed by the discharge gas or plasma in the lamp, the aperture type lamp of the configuration in which the ultraviolet light emitted from the plasma is emitted from the light extraction part after being reflected by the reflection film many times, This is because the luminous efficiency is significantly reduced.

At least light transmissive, elongated tubular,
A discharge vessel serving also as a dielectric of the dielectric barrier discharge, a light-transmissive outer electrode for performing a dielectric barrier discharge provided on at least a part of an outer surface of the discharge vessel, and disposed inside the discharge vessel. An elongated metal electrode or an elongated metal rod in a substantially tubular dielectric barrier discharge lamp comprising a discharge gas that forms excimer molecules by the dielectric barrier discharge filled in the discharge vessel. A tube, the inner electrode is in contact with a discharge gas, and the dielectric barrier discharge lamp emits light in a slit shape from a light extraction portion provided on a part of an outer peripheral surface of the discharge vessel. First, the excimer light is not absorbed by the discharge gas or plasma, so that an aperture lamp with high efficiency ultraviolet light emission can be realized. In two, since the inner electrode consisting of an elongated metal bar or elongated metal tube, less absorption of ultraviolet light by the inner electrode, thus high efficiency can be obtained, Third,
Since the inner electrode is in contact with the discharge gas, a large amount of power can be injected, and therefore, a high light output can be obtained, that is, a compact, high-intensity ultraviolet-emitting aperture-type dielectric barrier discharge lamp can be obtained.

In the aperture-type dielectric barrier discharge lamp, when a member that is electrically connected to the outer electrode and that is light-transmissive is provided on the outer surface of the light extraction portion, the dielectric barrier discharge lamp can be used. There is an advantage that it is possible to prevent the electromagnetic noise radio waves generated from leaking from the light extraction portion. In the aperture-type dielectric barrier discharge lamp, the outer electrode is provided on a part of an outer peripheral surface of the discharge vessel, the light extraction portion is located at a position opposite to the outer electrode, and the inner electrode is disposed on the discharge vessel. When the inner electrode is separated from the light extraction portion, the light extraction efficiency is increased because the inner electrode is separated from the light extraction portion, and the distance between the outer electrode and the inner electrode is reduced. Since it is shorter, there is an advantage that the discharge starting voltage is reduced. In the aperture-type dielectric barrier discharge lamp, the outer electrode is provided on a part of an outer peripheral surface of the discharge vessel, the light extraction portion is located at a position opposite to the outer electrode, and the inner electrode is disposed on the discharge vessel. In the configuration provided closer to the light extraction portion than the central axis of the electrode, the distance between the outer electrode and the inner electrode is increased, so that the discharge space can be enlarged, so that a large light output can be obtained with a thinner discharge vessel. This has the advantage of being

In the dielectric barrier discharge lamp, wherein the discharge vessel is a cylinder and the inner electrode is a round bar or a tubular metal, the inner diameter of the cylindrical discharge vessel is a round bar or a tubular metal. When the outer diameter of the inner electrode is less than 3 times, the absorption of visible light by the inner electrode becomes negligible, and in the region exceeding 40 times the outer diameter of the inner electrode, There is a disadvantage that the discharge becomes unstable due to the imbalance of the electrode area with the electrode. That is, the discharge vessel is a cylinder, the inner electrode is a round bar or a tubular metal, and the inner diameter of the discharge vessel is configured to be 3 to 40 times the outer diameter of the inner electrode. Thus, a dielectric barrier discharge lamp having sufficient luminous efficiency and stable light output can be obtained.

[0022] In the dielectric barrier discharge lamp, wherein the discharge vessel is a cylinder and the inner electrode is a round bar or a tubular metal, the outer electrode is provided around the entire circumference of the discharge vessel. If the distance between the center axis of the inner electrode and the center axis of the discharge vessel is set to be larger than the outer diameter of the inner electrode, the distance between the inner electrode and the outer electrode becomes shorter, so that the discharge starting voltage is reduced. This has the advantage that the lighting power supply is simplified. The effect of lowering the discharge starting voltage is significant when the distance between the central axis of the inner electrode and the central axis of the discharge vessel is greater than the outer diameter of the inner electrode.

When the outer electrode is formed of a seamless cylindrical wire mesh, there is no overlap between the edges of the wire mesh which occurs when a flat wire mesh is wound to form a cylindrical shape. This has the advantage that is smaller.

[0024]

FIG. 1 shows a dielectric barrier discharge lamp according to a first embodiment of the present invention. The discharge vessel 1 is composed of a synthetic quartz glass tube having an inner diameter of 5 mm and a total length of 200 mm, and one end 11 of the tube.
, One end of the inner electrode 5 is hermetically attached, and the other end 12 of the discharge vessel 1 is hermetically closed. The inner electrode 5
An empty rod made of tungsten and having a diameter of 1 mm, coaxial with the discharge vessel 1, and the other end 6 of the inner electrode is present in the discharge vessel. The method of airtightly attaching the inner electrode to one end 11 of the discharge vessel is as follows. First, a glass having a coefficient of thermal expansion equivalent to the coefficient of thermal expansion of tungsten is applied to tungsten, and then the quartz glass and the coefficient of thermal expansion of tungsten are coated thereon. A so-called graded seal method, in which a glass having an intermediate coefficient of thermal expansion was applied, was used. One end of the inner electrode is drawn out of the discharge vessel 1 and connected to a power supply 21. A seamless stainless steel wire mesh is provided on the outer surface of the discharge vessel 1 as the outer electrode 4. The outer electrode 4 is also provided on the outer surface of the other end 12 of the discharge vessel which is hermetically closed. Xenon was filled in the discharge vessel 1 as discharge gas at 30 kPa from an exhaust pipe provided near one end 11.
3 is the rest of the exhaust pipe. When a high frequency voltage of 20 kHz and 3 kV is applied between the outer electrode 4 and the inner electrode 5 by the power supply 21, stable dielectric barrier discharge occurs,
As a result, vacuum ultraviolet rays having a maximum value at a wavelength of 172 nm were efficiently emitted. The characteristics of the dielectric barrier discharge lamp of this embodiment can be summarized as follows. First, the phenomenon that the discharge plasma converges in a single line is less likely to occur, and therefore, the fluctuation of the light output is small. Third, the thinner inner electrode with a small surface area is in contact with the discharge gas, so that sufficient power can be injected into the discharge space, and therefore the light output is sufficiently high. Fourth, since the lamp emits light up to the other end 12 of the discharge vessel 1, the ratio of the effective emission length of the lamp is increased, and therefore, a stable and compact dielectric barrier discharge lamp having a large light output is obtained.

FIG. 2 shows a dielectric barrier discharge lamp according to a second embodiment of the present invention. The inner electrode 5 has a tubular shape, and both ends are hermetically fixed and sealed to both ends 11 and 12 of the discharge vessel. In this case, there is an advantage that the weight is reduced because the electrode is hollow. A powder getter 2, which is an alloy of zirconium and titanium, is applied to a part of the surface of the inner electrode 5. In the present embodiment, there is an advantage that the lamp does not become large despite the provision of the getter, and the weight is reduced because the inner electrode is a hollow tube.

FIG. 3 shows a dielectric barrier discharge lamp according to a third embodiment of the present invention. The structure of the lamp of this embodiment is such that, in addition to the lamp structure of the first embodiment, the other end 6 of the inner electrode 5 is embedded in the other end 12 of the discharge vessel 1 and fixed. Advantages such as easy alignment of the central axis of the discharge vessel 1 and the inner electrode 5 to obtain a lamp with less variation, and higher mechanical strength because both ends of the inner electrode 5 are fixed are obtained.

FIG. 4 shows a dielectric barrier discharge lamp according to a fourth embodiment of the present invention. The structure of the lamp of the present embodiment has a total length of 30 in addition to the lamp structure of the first embodiment.
0 mm, and the other end 6 of the inner electrode 5 is inserted into a recess 7 provided in the other end 12 of the discharge vessel 1 and held loosely. It is applied all over. In this embodiment, the manufacture of the lamp becomes easy, and even if the thermal expansion coefficients of the inner electrode 5 and the discharge vessel 1 are different, the difference is absorbed by the recess 7, so that the total length of the lamp is 300 mm. Despite its long length, a highly reliable dielectric barrier discharge lamp was obtained.

FIG. 5 shows a dielectric barrier discharge lamp according to a fifth embodiment of the present invention. The structure of the lamp of the present embodiment is such that the recess 7 in the lamp structure of the fourth embodiment is also used as the remaining portion 3 of the exhaust pipe of the dielectric barrier discharge lamp, so that the manufacturing is further facilitated and the cost is reduced. This has the advantage of becoming

FIG. 6 is a sectional view of a dielectric barrier discharge lamp according to a sixth embodiment of the present invention. The lamp of this embodiment is
With the configuration in which the discharge vessel 1 in the dielectric barrier discharge lamp of the fifth embodiment is a hollow elliptical cylinder, there is an advantage that a thin dielectric barrier discharge lamp can be obtained in addition to the advantage of the fifth embodiment. .

FIG. 7 is a sectional view of an aperture type dielectric barrier discharge lamp according to a seventh embodiment of the present invention. In the lamp of the present embodiment, an outer electrode 8 also serving as a light reflection plate made of aluminum is provided on a part of the outer peripheral surface of the discharge vessel 1, and a tube wall portion where the outer electrode 8 is not provided is
This is a configuration in which the light extraction portion 9 is provided. This portion extends like a slit along the longitudinal direction of the lamp. Since the inner electrode 5 provided in the discharge vessel 1 is thin and large power can be injected, it is possible to obtain an aperture-type dielectric barrier discharge lamp which is compact and has a large light output.

FIG. 8 is a sectional view of an aperture type dielectric barrier discharge lamp according to an eighth embodiment of the present invention. The lamp structure of the present embodiment is configured such that the discharge vessel 1 of the aperture type dielectric barrier discharge lamp of the seventh embodiment is a hollow elliptical cylinder, and the light extraction portion 9 is provided on the tube wall in the long axis direction. Since the discharge space can be made larger than the light extraction part 9,
A higher brightness aperture-type dielectric barrier discharge lamp is obtained.

The aperture-type dielectric barrier discharge lamp according to the ninth embodiment of the present invention is different from the aperture-type dielectric barrier discharge lamp according to the eighth embodiment in that the light-extracting portion 9 of the discharge lamp 1 has
Is provided on the tube wall in the short axis direction. There is an advantage that the light extraction portion 9 can be made larger than the thickness of the discharge vessel 1. That is, a thinner aperture type dielectric barrier discharge lamp can be obtained.

FIG. 9 is a sectional view of an aperture type dielectric barrier discharge lamp according to a tenth embodiment of the present invention. In the lamp of the present embodiment, a light reflecting film 10 made of a multilayer dielectric film is provided on a part of the inner peripheral surface of the discharge vessel 1. It is a take-out portion 9, and furthermore, the outer electrode 4 made of a seamless cylindrical metal net is provided all around the outer surface of the discharge vessel 1. That is, the portion of the outer electrode 4 existing on the outer surface of the light extraction portion 9 is electrically connected to the outer electrode, and corresponds to a light-transmitting member because it is a net.
Therefore, there is an advantage that the electromagnetic noise radio waves generated by the dielectric barrier discharge can be prevented from leaking from the light extraction portion 9.

FIG. 10 is a sectional view of an aperture type dielectric barrier discharge lamp according to an eleventh embodiment of the present invention. The structure of the lamp of this embodiment is the same as that of the seventh embodiment except that the inner electrode 5 is provided closer to the light extraction portion 9 than the central axis X of the discharge vessel 1. Such a structure has the advantage of increasing the distance between the outer and inner electrodes, thus increasing the input to the lamp and therefore the light output.

FIG. 11 is a sectional view showing an aperture type dielectric barrier discharge lamp according to a twelfth embodiment of the present invention. The structure of the lamp of this embodiment is the same as that of the seventh embodiment except that the inner electrode 5 is provided farther from the light extraction portion 9 than the central axis X of the discharge vessel 1. With such a structure, the distance between the outer electrode and the inner electrode is shortened, so that the discharge starting voltage is lowered, and the inner electrode 5 is separated from the light extraction portion 9, so that the light Has an advantage that the take-out efficiency is increased and the efficiency is high.

In the dielectric barrier discharge lamp according to the thirteenth embodiment of the present invention, the inner electrode 5 of the dielectric barrier discharge lamp according to the first embodiment is positioned 1.5 mm from the central axis of the discharge vessel 1.
It is a configuration in which it is staggered. In this embodiment, there is an advantage that the discharge starting voltage is reduced.

[0037]

As described above, according to the present invention, it is possible to provide a dielectric barrier discharge lamp which is compact, has a sufficiently large light output, is high in brightness, and is stable.

[Brief description of the 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 view of another embodiment of the dielectric barrier discharge lamp of the present invention.

FIG. 3 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention.

FIG. 4 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention.

FIG. 5 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention.

FIG. 6 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention, showing a cross section perpendicular to the longitudinal direction of the lamp.

FIG. 7 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention, showing a cross section perpendicular to the longitudinal direction of the lamp.

FIG. 8 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention, showing a cross section perpendicular to the longitudinal direction of the lamp.

FIG. 9 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention, showing a cross section perpendicular to the longitudinal direction of the lamp.

FIG. 10 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention, showing a cross section perpendicular to the longitudinal direction of the lamp.

FIG. 11 is an explanatory view of another embodiment of the dielectric barrier discharge lamp of the present invention, showing a cross section perpendicular to the longitudinal direction of the lamp.

FIG. 12 is an explanatory view of a conventional dielectric barrier discharge lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge container 2 Getter 3 Remaining part of exhaust pipe 4 Outer electrode 5 Inner electrode 6 The other end of inner electrode 7 Depression 8 Outer electrode 9 Light extraction part 10 Light reflection film

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriyoshi Hishinuma, 1194 Sado, Bessho-cho, Himeji-shi, Hyogo Ushio Electric Co., Ltd. Examiner Katsumi Enari in Oh Electric Co., Ltd. (56) References JP-A-3-201358 (JP, A) JP-A-2-309552 (JP, A) JP-A-4-223039 (JP, A) JP JP-A-5-190150 (JP, A) JP-A-5-190152 (JP, A) JP-A-57-63756 (JP, A) JP-A-53-146480 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) H01J 65/04 H01J 61/06

Claims (5)

(57) [Claims] 1. A discharge vessel having an elongated tubular shape and also serving as a dielectric for dielectric barrier discharge, a light-transmitting outer electrode provided on at least a part of an outer surface of the discharge vessel, and An inner electrode formed of an elongated metal round bar or an elongated metal circular tube which is disposed inside the discharge vessel and has a value L / D of a ratio of the length L to the outer diameter D of 30 or more; A dielectric-barrier discharge lamp, comprising: a discharge gas filled so as to form excimer molecules by the dielectric-barrier discharge; and a getter attached to the inner electrode. 2. A discharge vessel having an elongated tubular shape and also serving as a dielectric for dielectric barrier discharge, a light-transmissive outer electrode provided on at least a part of an outer surface of the discharge vessel, and An inner electrode formed of an elongated metal round bar or an elongated metal circular tube which is disposed inside the discharge vessel and has a value L / D of a ratio of the length L to the outer diameter D of 30 or more; A discharge gas that forms excimer molecules by the dielectric barrier discharge filled so as to be in contact with one end of the inner electrode, and one end of the inner electrode is hermetically attached to one end of the discharge vessel, and is drawn out of the discharge vessel. ,
The other end of the inner electrode is loosely held in a remaining portion of an exhaust pipe formed at the other end of the discharge vessel. 3. A discharge vessel having an elongated tubular shape and also serving as a dielectric for dielectric barrier discharge, a light-transmissive outer electrode provided on at least a part of an outer surface of the discharge vessel, and An inner electrode formed of an elongated metal round bar or an elongated metal circular tube which is disposed inside the discharge vessel and has a value L / D of a ratio of the length L to the outer diameter D of 30 or more; A discharge gas that forms excimer molecules by the dielectric barrier discharge filled so as to be in contact with the discharge vessel; the discharge vessel has a portion that takes out light in a slit shape along the longitudinal direction thereof; A dielectric barrier discharge lamp, wherein the outer electrode is also provided on an outer surface. 4. The dielectric barrier discharge lamp according to claim 3, wherein said inner electrode is closer to said light extraction portion than a center axis of said discharge vessel. 5. A discharge vessel having a long and narrow tubular shape and also serving as a dielectric for dielectric barrier discharge, a light-transmitting outer electrode provided on at least a part of an outer surface of the discharge vessel, An inner electrode formed of an elongated metal round bar or an elongated metal circular tube which is disposed inside the discharge vessel and has a value L / D of a ratio of the length L to the outer diameter D of 30 or more; A dielectric-barrier discharge lamp, characterized in that a discharge gas that forms excimer molecules by the dielectric-barrier discharge filled so as to be in contact with the dielectric-barrier discharge, and the outer electrode is made of a seamless cylindrical metal mesh.