JP2002319371A - Dielectric barrier discharge lamp, device for lighting dielectric barrier discharge lamp, and ultraviolet irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain high ultraviolet ray illuminance. SOLUTION: A mesh-like internal electrode 2 arranged with a large number of unit mesh portions 2b at a pitch P (mm) is equipped sealedly along an axial direction of a slim tubular air-tight container 1 comprising an ultraviolet ray transmitting material and having an inside diameter of DLI (mm), excimer generating gas is sealed inside the air-tight container 1, an external electrode 3 is arranged in an outer face of the container 1, and DLI.P satisfys following expression: 90<DLI.P<150. A difference DOI-DLO between an outside diameter DLO (mm) of the air-tight container 1 and an inside diameter DOI (mm) of an outer tube OT may satisfy following expression: 2<DOI-DLO<8, instead of satisfying the expression hereinbefore.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric barrier discharge lamp, a dielectric barrier discharge lamp lighting device using the same, and an ultraviolet irradiation device.

[0002]

2. Description of the Related Art An excimer discharge lamp, that is, a dielectric barrier discharge lamp, which emits a near-monochromatic radiation by causing a noble gas such as xenon or a mixed gas such as xenon or krypton and a chlorine gas or the like to emit silently, It is described in a number of documents and is conventionally known.
In the dielectric barrier discharge, a pulsed current flows due to a so-called silent discharge. This pulsed current has a high-speed electron flow and many pauses, so the substance that emits ultraviolet light, such as xenon, is temporarily combined with the molecular state (excimer state) and reabsorbed when returning to the ground state. Efficiently emits less UV rays.

[0003] Conventionally, a dielectric barrier discharge lamp generally used is, as disclosed in Japanese Patent No. 2854250, for example, in which an inner tube and an outer tube are separated from each other to form an annular end plate and a circular end plate. And a coaxial cylindrical discharge vessel formed by closing both ends. The outer tube also serves as a radiation outlet window. One of a pair of electrodes provided in the coaxial cylindrical discharge vessel is a conductive mesh electrode, and is mounted on the outer tube of the coaxial discharge vessel. The other electrode is a conductive thin-film electrode, formed on the inner tube of the coaxial discharge vessel,
Also serves as a reflector. In addition, bases are respectively attached to both end plates of the coaxial cylindrical discharge vessel, and are used for supporting a dielectric barrier discharge lamp. Then, a high frequency high voltage is applied between the conductive mesh electrode and the conductive thin film electrode from the power source,
Supplies the electrical energy required for dielectric barrier discharge.
(Prior Art 1) The prior art 1 has a relatively large amount of ultraviolet rays generated, but has the following problems. That is, since a discharge occurs through two glass walls serving as dielectrics, several kV
High frequency high voltage is required. For this reason, the high-frequency transformer that generates a high voltage not only becomes extremely large but also difficult to manufacture and expensive. In addition, the structure of the discharge vessel is complicated, and the amount of quartz glass used increases, which also increases the cost.

On the other hand, Japanese Patent Application Laid-Open No. 11-111235
Japanese Patent Laid-Open Publication No. H11-157, discloses a dielectric barrier discharge lamp that stably performs a dielectric barrier discharge without applying a high voltage as described above using an elongated tubular airtight container. In this dielectric barrier discharge lamp, one of the electrodes is exposed and sealed as an internal electrode extending along the center axis direction in an elongated tubular airtight container filled with excimer-produced gas, and the other electrode is externally sealed. The electrodes are configured in a mesh structure. In addition, when the internal electrodes are electrically heated from the outside, the starting electrons can be emitted and the starting voltage can be greatly reduced. In addition, since it has a simple structure and uses a small amount of quartz glass, it can be obtained at low cost. (Prior art 2) However, in prior art 2, since the internal electrode expands and hangs down due to external heating, when the dielectric barrier discharge lamp is turned on horizontally, the vertical distance between the internal electrode and the external electrode increases. The distance between the electrodes in the direction tends to change along the longitudinal direction of the airtight container.

Japanese Patent Application Laid-Open No. Hei 7-272692 discloses a light-transmitting, elongated tubular, light-transmitting external electrode on the outer surface of a discharge vessel also serving as a first dielectric of a dielectric barrier discharge. There has also been proposed a structure provided with an inner electrode formed of a metal rod or a metal pipe having a ratio L / D of length L to diameter D of 30 or more inside. (Prior Art 3) However, Conventional Technique 3 has a problem that the internal electrode is vulnerable to vibration and impact because it is cantilevered.

On the other hand, the present inventors have proposed a configuration in which an internal electrode is provided by the action of tension, or a position restrictor, ie, an anchor is attached to the internal electrode, so that the internal electrode is drooped. Invented a dielectric barrier discharge lamp that suppresses the above. This invention is disclosed in Japanese Patent Application No. 11-25992.
No. 3 has been filed. (Prior Art 4) According to Prior Art 4, since the anchor is made of a conductive metal, the anchor also acts as a part of the inner electrode, so that the distance between the inner and outer electrodes is reduced and the startability is improved. .

Further, the present inventors housed the dielectric barrier discharge lamp of the prior art 4 in an outer tube made of a material which is further transparent to ultraviolet light and through which a gas such as nitrogen gas having little ultraviolet absorption is passed. And a dielectric barrier discharge lamp. Moreover, by forming the external electrode in a mesh shape having a spiral portion, the manufacture of the external electrode is facilitated. This invention is disclosed in Japanese Patent Application No. 11-2599.
No. 23 has been filed. (Prior Art 5) According to Prior Art 5, it became possible to mount a dielectric barrier discharge lamp in an exposed state on an ultraviolet irradiation device. This eliminates the need for a conventionally used flat light extraction window made of synthetic quartz glass. Originally, it was difficult to manufacture flat synthetic quartz glass, and there was a problem of high cost.However, if a large area light extraction window was required as the work area increased, this could be met. become unable. On the other hand, according to the related art 5, there is no restriction as described above.

[0008]

However, there is a demand to obtain higher ultraviolet illuminance.

The present inventors have further studied and found that the inner diameter of the hermetic container in which the excimer generated gas is sealed and the pitch of the unit mesh portion of the internal electrode sealed in the hermetic container with respect to the axial direction of the hermetic container. It has been found that the relationship between the irradiance influences the ultraviolet illuminance, and that by optimizing the inner diameter and the pitch, the ultraviolet illuminance can be increased.

In the case where the arc tube having the airtight container, the internal electrode, the excimer generation gas and the external electrode is housed in the outer tube, the relationship between the outer diameter of the airtight container and the outer diameter of the outer tube is determined. It has been found that the influence of the ultraviolet illuminance can be increased and the ultraviolet illuminance can be increased by optimizing the outer diameters.

Further, when high-frequency pulse lighting is performed such that the internal electrode is an anode and the external electrode is a cathode, the pitch of the unit mesh portion of the internal electrode in the axial direction of the hermetic container affects the illuminance of ultraviolet rays. It has been found that by optimizing, the UV illuminance can be increased.

An object of the present invention is to provide a dielectric barrier discharge lamp capable of obtaining high ultraviolet illuminance, a dielectric barrier discharge lamp lighting device using the same, and an ultraviolet irradiation device.

[0013]

A dielectric barrier discharge lamp according to the first aspect of the present invention is made of an ultraviolet-permeable material, and has an elongated tubular airtight container having an inner diameter of _DLI (mm); Is the pitch P (m
m) an internal electrode which is formed in a mesh and is sealed in an airtight container along the axial direction thereof; an excimer product gas sealed in the airtight container; and an outer surface of the airtight container. has been the external electrodes; comprises a, D L _{I ·} P is a satisfies the following equation.

90 < _DLI · P <150 In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

[0015] The dielectric barrier discharge lamp includes an airtight container, an internal electrode, an excimer generated gas, and an external electrode. Hereinafter, each component will be described.

<About Airtight Container> An airtight container made of a material that transmits ultraviolet light can be generally manufactured using synthetic quartz glass. However, the present invention may be made of any material as long as it is transparent to vacuum ultraviolet light of the wavelength to be used.

The inner diameter D _LI (mm) of the airtight container is defined in a predetermined range in relation to a pitch P of a unit mesh portion of the internal electrode described later. On the other hand, the inner diameter and thickness of the hermetic container are not directly limited by themselves, but the outer diameter is preferably 12 mm or more in order to increase the ultraviolet output. In order to lower the discharge starting voltage, the inner diameter is preferably set to 25 mm or less. Furthermore, the thickness is 2m
m, preferably about 0.3 to 1 mm. On the other hand, the length of the airtight container is not limited at all, and can be set to an arbitrary length, for example, about 1 m in accordance with a required ultraviolet irradiation length.

Generally, an exhaust pipe is connected to the airtight container as a means for filling the excimer generated gas after exhausting the inside of the airtight container. In the present invention, when the exhaust pipe is connected, the exhaust pipe may be connected to any part of the airtight container, but by connecting the exhaust pipe to the side surface, the connection work of the exhaust pipe and the exhaust / sealing work become easy. When the gas is exhausted through the exhaust pipe, the excimer product gas is sealed in the airtight container from the exhaust pipe, and the exhaust pipe is chipped off, thereby forming an exhaust chip-off portion.

The airtight container is not limited to a straight tube as long as it is tubular, and may be curved. The cross-sectional shape of the tube is generally circular, but a desired cross-sectional shape such as an ellipse or a square can be used if necessary.

<Regarding the Internal Electrode> The internal electrode has a mesh shape in which a large number of unit mesh portions are arranged in the axial direction of the hermetic container with a gap therebetween. In the present invention, `` a large number of unit mesh portions are in the form of a mesh arranged via a gap in the axial direction of the airtight container '', and the unit mesh portions approach the inner wall surface of the airtight container, and Refers to a state in which they are spatially separated from each other in the axial direction of the airtight container, but are electrically connected. The unit mesh portion may be continuous in the circumferential direction or may be divided. Therefore, specifically, the unit mesh portion is allowed to have, for example, a ring shape (former of the former), a spiral shape or a coil shape (form of the latter), or a mesh shape. In addition,
In the case of a mesh, the former or the latter belongs depending on the configuration of the mesh.

When the unit mesh portions have a ring shape, a plurality of unit mesh portions are connected at a predetermined pitch by providing a connection portion extending in the axial direction of the airtight container, and It can be conductively connected. By configuring the connecting portion to extend along the central axis of the airtight container, the entire inner electrode is provided with a number of ring anchors (corresponding to a unit mesh portion), the filament of a halogen lamp for copying. And the manufacturing equipment can be diverted to facilitate the manufacturing. However, if necessary, a configuration in which the center axis of the airtight container is removed and the connecting portion is directly connected to the ring portion of the mesh-like portion may be adopted. The connecting portion may be a single linear line, or the outer diameter may be 20% of the inner diameter of the hermetic container.
The following coil shape may be used. Further, the connecting portion can be sealed in a state in which an appropriate value of tension, preferably 2 kg or more, acts in the central axis direction. In order to exert a tension, it is advantageous to form the internal electrode in a coil shape. Even if it is not a coil shape, a tension in the central axis direction can be applied to the connecting portion. Regardless of the shape of the connecting portion, sealing at both ends of the airtight container at both ends makes it easier to apply tension to the connecting portion. However, if necessary, the connecting portion is sealed to only one side of the airtight container at one end, and the other end is fixed to the sealing portion by appropriate means, such as an anchor wire, at the other end of the airtight container. Can also be tensioned.

On the other hand, when the unit mesh portion has a spiral shape or a mesh shape, the spiral or mesh portion also functions as a connecting portion, and a large number of unit mesh portions are mechanically and mutually connected. Conductively connect.
However, the shape retention of the internal electrode can be further imparted by welding a connecting portion made of a single or a plurality of rods to a spiral or mesh unit mesh portion. Alternatively, when a spiral or mesh-shaped unit mesh portion is formed by using a winding frame instead of the connecting portion of the rod-like body, shape retention is improved. The winding frame may be either insulating or conductive. If any one of the above-described configurations is employed for the mesh-like portion, shape stability can be imparted to the entire internal electrode, and handling thereof can be facilitated.

Also, the internal electrode is arranged such that a product p · P of a pitch P (m) of the unit mesh portion in the axial direction with a pressure p (Pa) of an excimer generation gas described later falls within a predetermined range. Be composed.

Further, in the present invention, even if the lamp efficiency is improved by increasing the filling pressure of the excimer generation gas as described later, the distance between the unit mesh portion and the inner wall surface of the hermetic container is reduced. It can be 3 mm or less. When the distance is 3 mm or less, the discharge sustaining voltage can be suppressed to 1000 V or less under certain conditions.

Further, the material constituting the internal electrode is not particularly limited. For example, a refractory metal such as tungsten, molybdenum, and nickel may be used. Tungsten and nickel have a relatively small work function.
Since electrons are easily emitted, it is effective in lowering the starting voltage.

Furthermore, in order to seal the internal electrode to the end of the airtight container made of quartz glass, a sealing structure using a sealing metal foil, which is frequently used when compactly sealing the quartz glass, is employed. can do. Further, the sealing metal foil can be hermetically sealed by pinch sealing the quartz glass.

<Excimer Product Gas> The excimer product gas may be a mixture of one or more rare gases such as xenon, krypton, argon or helium, or a mixture of a rare gas and a halogen such as fluorine, chlorine, bromine or iodine. XeCl, KrCl, or the like can be used. In addition, a gas that does not generate excimer, such as neon, may be mixed and used in addition to the excimer generating gas.

Further, the pressure of the excimer product gas is set to 200
It can be set to 00 Pa or more. As the pressure increases, the lamp efficiency increases and the UV output increases. However, the lamp efficiency tends to be saturated with an increase in pressure.

<Regarding the External Electrodes> The external electrodes act to generate a dielectric barrier discharge between the internal electrodes and the wall surface of the airtight container as a dielectric. The external electrodes may be formed in a mesh shape in order to lead ultraviolet light emitted from the excimer generated by the dielectric barrier discharge to the outside and increase ultraviolet light emission. In the present invention, "the external electrode has a mesh shape",
The external electrode is substantially in contact with the outer surface of the hermetic container, and a number of unit mesh portions are arranged at predetermined pitches in the axial direction of the hermetic container via the respective gaps, and each unit mesh portion is arranged in the axial direction. Are electrically connected. However, the unit mesh portion may be continuous or divided in the circumferential direction. Therefore, specifically, the unit mesh portion is allowed to have, for example, a spiral shape (coil shape) or a mesh shape.

When the external electrode is formed in a mesh shape due to the spiral shape (coil shape),
By winding the metal wire around the outer surface of the hermetic container at a predetermined pitch, it is possible to form an external electrode composed of a plurality of turns of the coil. However, by spirally connecting the spiral portion of the external electrode with one or more conductive rods so as to short-circuit, the distribution of inductance to the external electrode is practically prevented, and the resistance of the external electrode is reduced. Can be greatly reduced. Thus, it is possible to suppress a decrease in the uniformity of the ultraviolet illuminance distribution generated in the axial direction due to inductance and resistance distributed in the external electrode in the axial direction of the airtight container. In addition, the conductive rod-shaped body can be sandwiched between the airtight container and the spiral portion, or can be joined by welding to the spiral portion from the outside.

On the other hand, in the case where the external electrodes are formed in a mesh shape due to the mesh shape, the mesh shape can be constituted by, for example, knitting, tortoiseshell, flat knitting, punching, or the like. . Since the knitted fabric is particularly excellent in elasticity, it is easy to prepare a cylindrical mesh structure with an inner diameter larger than the outer diameter of the airtight container, place it outside the airtight container, and pull it toward both ends. By reducing the diameter, the external electrode can be brought into contact with the outer surface of the airtight container. Also, wrap the mesh structure spread out in a plate shape around the side of the airtight container and abut or overlap the both sides, then tie it through a wire to the side edge of the mesh structure, or fold it into a U-shape etc. It may be secured using a curved mechanical lock.

The external electrode can be formed using a suitable metal such as stainless steel, nickel and molybdenum.

Further, in order to increase the generation of ultraviolet rays due to dielectric barrier discharge, the external electrodes are preferably formed in a mesh shape using a metal wire as thin as possible, preferably about 0.05 to 0.5 mm. .

<Product D _LI · P of Inner Diameter D _LI and Pitch P of Unit Mesh Portion> Inner Diameter D of Airtight Container
_LI (mm) and pitch P of unit mesh part of internal electrode
Product _D LI · P and (mm) (mm ²⁾ is 90 super 15
When it is less than 0, high ultraviolet illuminance can be obtained. On the other hand, _DLI · P (mm ² ) is less than 90 and 1
Irrespective of 50 or more, the ultraviolet illuminance decreases.
The above relationship is as shown in FIG.

FIG. 1 is a graph showing the relationship between _DLI · P and ultraviolet illuminance using the outer diameter of the airtight container as a parameter.
In the figure, the horizontal axis represents _DLI · P (mm ² ), and the vertical axis represents ultraviolet illuminance (relative value).

As can be seen from the figure, the figure
In any of 1.5 mm, 14 mm, and 18 mm, if _DLI · P (mm ² ) is more than 90 to less than 150, it indicates that high ultraviolet illuminance can be obtained. The highest UV illuminance can be obtained by _DLI
When P (mm ² ) is about 120, more than 90 to 15
If it is less than 0, an illuminance of 90% or more of the highest ultraviolet illuminance can be obtained.

<Other Structures> Although not essential components of the present invention, the following structures can be selectively added as desired.

(1) Outer tube The outer tube is used when the arc tube is housed and used therein, whereby the dielectric barrier discharge lamp can be irradiated with an ultraviolet irradiation device without using a flat light extraction window. To be used directly. The outer tube is made of a material that transmits ultraviolet light, for example, synthetic quartz glass.

2 Regarding the base body In order to facilitate the energization of the dielectric barrier discharge lamp,
Caps having an appropriate shape and structure can be attached to both ends of the airtight container. When the outer tube is used, the end member supporting the outer tube is formed of an insulating member such as ceramics, and this can be used as an insulating base of the base member to form the base member. It should be noted that one of the bases may be on the high voltage side and the other may be on the ground side, so that a structure suitable for each can be provided.

<Regarding the Operation of the Present Invention> When a high-frequency voltage is applied between the internal electrode and the external electrode, a pulse-like dielectric barrier discharge is generated mainly between the external electrode and the unit mesh portion of the internal electrode. Then, a vacuum ultraviolet ray of the resonance line of the rare gas is generated. For example, when xenon is sealed, ultraviolet rays of 172 nm are mainly generated. The product D _LI · P (mm ² ) of the inner diameter D _LI (mm) of the airtight container and the pitch P (mm) of the mesh portion of the internal electrode is 90.
Since the range is from super to less than 150, high ultraviolet illuminance can be obtained.

The dielectric barrier discharge lamp according to the second aspect of the present invention is an elongated tubular airtight container made of an ultraviolet-permeable material having an outer diameter of D _LO (mm). And an arc tube having an excimer-producing gas sealed in an airtight container, and an external electrode disposed on the outer surface of the airtight container; and an outer diameter D _OI ( an elongated tubular and the outer tube of mm); equipped with, D _OI -D _LO is characterized by satisfying the following equation.

[0042] _{2 <D OI -D LO <8} < light emitting tube> arc tube, the airtight container is provided with an internal electrode, excimer product gas and the external electrodes. The “arc tube” is an expression used for convenience when the dielectric barrier discharge lamp has an outer tube. When the outer tube is not used, the arc tube constitutes a dielectric barrier discharge lamp. .

The outside diameter D _LO (mm) of the airtight container is:
As described later, it is defined in a predetermined range in relation to the inner diameter D _OI (mm) of the outer tube.

<Regarding Outer Tube> The outer tube is used for the purpose of housing the arc tube therein to protect the arc tube, discharge the heat generated by the arc tube, and suppress the attenuation of ultraviolet rays. . Then, the arc tube is configured to be turned on in a state where the inside of the outer tube is filled with a gas having low ultraviolet absorption such as nitrogen or argon. Even if the vacuum ultraviolet rays pass through the gas, the attenuation is small, so that the problem of ultraviolet attenuation does not occur even if the gas is filled in the outer tube. When nitrogen gas is used, since nitrogen has a higher thermal conductivity than air, heat generated in the arc tube by lighting through nitrogen is easily discharged to the outside, and cooling of the arc tube is promoted. The gas can be filled in such a manner as to flow through the outer tube. Thereby, even if the amount of heat generated by the arc tube is large, it can be cooled as desired. However, by appropriately balancing the heat radiation amount of the arc tube, the inner diameter of the outer tube, and the sealing pressure of the nitrogen gas, the outer tube can be filled in a sealed-off mode.

The inner diameter of the outer tube is _DOI (mm).
And the outer diameter D _LO (m
m) in a predetermined range.

Further, although the outer tube and the arc tube are generally arranged concentrically, they may be eccentric if necessary.
By decentering the arc tube so as to approach the work, the ultraviolet illuminance can be improved. The specific configuration for accommodating the arc tube in the outer tube is not particularly limited, but when nitrogen gas is allowed to flow inside, for example, heat-resistant end members are attached to both ends of the arc tube, A structure can be adopted in which both ends of the outer tube having the open end are supported by a pair of end plate members. And nitrogen gas can be supplied and discharged through the end member. That is, a configuration is formed in which a pair of end members are provided with an air passage communicating with the inside and outside of the outer tube, one end member is connected to a nitrogen supply pipe, and the other end member is connected to a nitrogen discharge pipe. I do.

Further, in order to attach both ends of the outer tube to the ultraviolet irradiation device, a metal pipe made of stainless steel or the like can be attached to both ends of the outer tube and reinforced.

<Inner diameter D _{OI of} outer tube and outer diameter D of hermetic container
For the difference _D OI _{-D LO} of _LO> difference _D OI _{-D LO} outer diameter _{D LO} outer diameter _{D OI} and airtight container outer tube, the outer tube, the size of the gap formed around the airtight container When the value is 4 mm, the UV illuminance is the largest, and as shown in FIG. 2, when the value is more than 2 to less than 8, it is found that 90% or more of the maximum value of the UV illuminance is secured. . In addition, if the outer diameter of the airtight container is 12 mm or more, the ultraviolet illuminance increases. Therefore, if the outer diameter of the airtight container is 12 mm or more and the above conditions are satisfied, higher ultraviolet illuminance can be obtained.

[0049] Figure 2 is a graph showing the relationship between the outer diameter difference _D OI _{-D LO} and ultraviolet illumination. In the figure, the horizontal axis is D
_OI- D _LO (mm), the vertical axis is UV illuminance (relative value)
Are respectively shown.

As can be understood from the figure, the figure shows the outer diameter difference D
_{If OI−} D _LO (mm) is more than 2 and less than 8,
It shows that high UV illuminance can be obtained. In contrast, when the outer diameter difference _D OI _{-D LO} is 2 or less and 8 or more, ultraviolet illuminance becomes less than 90% of the maximum value. That is, if the outer diameter difference _D OI _{-D LO} is 2 or less,
The heat generated from the arc tube is less likely to be exhausted and tends to remain in the outer tube. For this reason, the amount of generated ultraviolet rays decreases. In contrast, if the outer diameter difference D _OI -D _LO is 8 or greater, the nitrogen gas be supplied to the outer tube, not sufficient, since the oxygen will be mixed, before the ultraviolet rays reach the workpiece Attenuated by oxygen.

[0051] Then, in the present invention, by an outer diameter difference _D OI _-D LO of the outer tube and the airtight container (mm) is a predetermined range, high ultraviolet intensity is obtained.

Also, since the outer tube is provided, metal ions from the external electrode do not impact the work.
Since the contamination of the work is prevented and the external electrodes are not exposed to the outside, cleaning of the dielectric barrier discharge lamp is facilitated.

According to a third aspect of the present invention, there is provided a dielectric barrier discharge lamp, which is an elongated tubular airtight container made of an ultraviolet-permeable material having an outer diameter of D _LO (mm), and is sealed in the airtight container in the axial direction of the airtight container. And an arc tube having an excimer-producing gas sealed in an airtight container and an external electrode disposed on the outer surface of the airtight container; and an outer diameter _DOO ( mm) an elongated tubular outer tube, wherein _DOO / _DLO satisfies the following expression.

1.2 < _DOO / _DLO <4 In the present invention, the distance between the arc tube and the work is optimized by the above configuration to improve the ultraviolet irradiation effect, and
The light distribution characteristics of ultraviolet irradiation on the work are improved.
That is, the outer diameter D _LO of the outer tube is compared with the outer diameter D _LO of the airtight container.
When the ratio D _{OO /} D _LO of _OO is 4 or more, the distance between the arc tube and the workpiece becomes too large, with UV illumination is decreased, the ultraviolet to the outside of the space requirement of the work is irradiated distribution Optical characteristics deteriorate. On the other hand, when the outer diameter ratio _DOO / _DLO becomes 1.2 or less, the flow of nitrogen gas into the outer tube is not sufficiently performed.

According to a fourth aspect of the present invention, there is provided a dielectric barrier discharge lamp, comprising: an elongated tubular airtight container made of a material that transmits ultraviolet light; an internal electrode sealed in the airtight container and extending in the axial direction of the airtight container; An excimer product gas sealed in an airtight container, and an arc tube having external electrodes disposed on the outer surface of the airtight container; a heat pipe disposed thermally conductive over substantially the entire outer surface of the arc tube; An elongate tubular outer tube through which a light emitting tube is housed and a nitrogen gas flows therein.

The present invention specifies a configuration for improving the uniformity of the ultraviolet intensity distribution in the longitudinal direction of the dielectric barrier discharge lamp using a heat pipe. That is, when nitrogen gas flows into the outer tube from one end of the outer tube and is discharged from the other end, the generated heat of the arc tube is conducted while flowing through the outer tube and the temperature of the nitrogen gas rises. A temperature gradient is formed in the longitudinal direction of the arc tube. For this reason, the intensity of the ultraviolet light changes under the influence of the temperature gradient, and the lamp efficiency is improved on the blowing side, while the lamp efficiency is reduced on the exhaust side, and as a result, the uniformity of the ultraviolet intensity distribution is reduced. There is.

On the other hand, in the present invention, the heat absorption side of the heat pipe is arranged on the high temperature side of the arc tube, and the heat radiation side is arranged on the low temperature side of the arc tube. It can be transported to the low temperature side. for that reason,
The temperature distribution in the longitudinal direction of the arc tube can be substantially averaged. Note that by using a heat pipe having a flat cross-sectional shape, it becomes easy to arrange the heat pipe even when the space between the arc tube and the outer tube is narrow.

Further, in implementing the present invention, the heat uniformity is promoted by adding a heat conductive metal to the arc tube and arranging the heat pipe on the heat conductive metal in a thermally conductive manner. Further, by configuring the heat conductive metal block with an ultraviolet reflective metal such as high-purity aluminum, it can also function as a reflector. Thereby, the illuminance of the ultraviolet light applied to the work can be improved.

Thus, in the present invention, the uniformity of the distribution of the ultraviolet illuminance along the longitudinal direction is improved.

In practicing the present invention, it is more effective to properly combine the inventions of claims 1 to 3.

A dielectric barrier discharge lamp according to a fifth aspect of the present invention is the dielectric barrier discharge lamp according to any one of the first to fourth aspects, wherein the internal electrodes extend substantially along the axis of the hermetic container. It is characterized in that it has a mesh shape including a unit mesh portion composed of a plurality of ring-shaped portions distributed in the portion and the connection portion.

The present invention defines a configuration in which the unit mesh portion of the internal electrode is formed of a ring-shaped portion. The outer diameter of the ring-shaped portion is d (mm), and the inner diameter of the hermetic container is D (mm).
(Mm), d / D can satisfy the following expression. In addition, by setting the distance between the inner surface of the airtight container and the mesh-shaped portion to 3 mm or less, the discharge starting voltage is reduced and the startability is improved. 3 <d
/D<1.0 The ring-shaped portion is preferably perpendicular to the axis of the airtight container, but ± 10 ° relative to the perpendicular.
If it is below, it can be inclined.

Further, both the connection portion of the internal electrode and the unit mesh portion including the ring-shaped portion can be formed of tungsten. However, the ring-shaped portion, that is, the unit mesh portion, may be formed using a dissimilar metal wire such as molybdenum or nickel.

Thus, in the present invention, the manufacture of the internal electrode is easy, and the droop of the connecting portion can be suppressed.

A dielectric barrier discharge lamp according to a sixth aspect of the present invention is the dielectric barrier discharge lamp according to any one of the first to fifth aspects, wherein the external electrode has a mesh shape formed by a plurality of turns of a coil. It is characterized by:

According to the present invention, since the external electrode is formed in a mesh shape composed of a plurality of turns of the coil as described above, the external electrode can be easily manufactured, and the vacuum ultraviolet rays emitted from the excimer can be easily led out. In addition, the presence of a large number of unit mesh portions can increase ultraviolet radiation.

A lighting device for a dielectric barrier discharge lamp according to a seventh aspect of the present invention is provided with an internal electrode including a unit mesh portion having a pitch of 4 mm or less in an axial direction of the airtight container. A dielectric barrier discharge lamp; and a high-frequency lighting circuit for supplying a high-frequency pulse to the dielectric barrier discharge lamp to turn on the dielectric barrier discharge lamp so that an internal electrode of the dielectric barrier discharge lamp serves as an anode and an external electrode serves as a cathode. It is characterized by doing.

In a dielectric barrier discharge in which the internal electrode is the anode and the external electrode is the cathode, ultraviolet radiation from the vicinity of the unit mesh portion of the internal electrode is large, and ultraviolet radiation from the middle of the adjacent unit mesh portion. Less. Therefore, it was found that when the pitch of the unit mesh portion was large, the uniformity of the ultraviolet illuminance in the axial direction of the airtight container was deteriorated, and the ultraviolet illuminance was also reduced. When the phases of the internal electrode and the external electrode are opposite, the above does not occur.

On the other hand, in the present invention, by setting the pitch of the unit mesh portion of the internal electrode to 4 mm or less, the valley portion where the ultraviolet illuminance between the unit mesh portions becomes low is reduced by each unit mesh portion. As a result, the uniformity of the ultraviolet illuminance in the axial direction of the hermetic container is significantly improved, and the ultraviolet illuminance is improved.

Further, since a strong afterglow light emission is generated by the pulse lighting, it contributes to the improvement of the illuminance of ultraviolet rays.

The high-frequency lighting circuit may be of any configuration as long as it outputs a pulse voltage. For example, a rectangular wave pulse can be obtained by using a rectangular wave output inverter. However, a configuration in which a sine wave pulse is obtained using a sine wave output inverter may be employed.

According to an eighth aspect of the present invention, there is provided an ultraviolet irradiating apparatus according to any one of the first to sixth aspects, an ultraviolet irradiating apparatus main body provided with the dielectric barrier discharging lamp, and a dielectric barrier. And a high frequency lighting circuit for lighting the discharge lamp.

In the present invention, the term "ultraviolet irradiation device" means any device that utilizes ultraviolet light generated from a dielectric barrier discharge lamp. For example, there are a semiconductor stepper, a light cleaning device, a light curing device, a light drying device, and the like. Further, the “ultraviolet irradiation device main body” means the remaining portion of the ultraviolet irradiation device excluding the dielectric barrier discharge lamp and the high-frequency generating means.

One or more dielectric barrier discharge lamps can be used as needed.

Further, a high frequency lighting circuit is used to light the dielectric barrier discharge lamp. The high-frequency lighting circuit includes high-frequency generating means, generates a high-frequency voltage, and supplies a dielectric barrier discharge lamp with high-frequency power necessary for lighting the lamp. Note that “high frequency” refers to a frequency of 10 kHz or more. However, preferably between 100 kHz and 2 MHz
It is. The high-frequency lighting circuit operates at a stable voltage of about 1500 V or less when the dielectric barrier discharge lamp is stably operated.
It is preferable to apply a high-frequency voltage of 0 to 1000 V.
Furthermore, the starting voltage of the dielectric barrier discharge lamp is 2 to
It is 2.3 kVp-p, and can be easily started by increasing the secondary open circuit voltage of the high frequency lighting circuit to the starting voltage. In this case, it is preferable that the high frequency generating means is mainly composed of a parallel inverter because a high boosting ratio can be easily obtained. Since the high-frequency output waveform is a sine wave, noise is reduced when the dielectric barrier discharge lamp is turned on. However, if necessary, a starting pulse voltage generating means can be used in addition to the high frequency generating means. Furthermore, it is preferable that the dielectric barrier discharge lamp and the high frequency lighting circuit are arranged at a close position, but they can be arranged at positions separated from each other if necessary. Unlike a general discharge lamp, the dielectric barrier discharge lamp does not need to connect current limiting means in series. However, in order to adjust the lamp current to a predetermined value, lighting by connecting an appropriate value of impedance in series can be performed as necessary. In addition, when the dielectric barrier discharge lamp is connected to the high-frequency lighting circuit, noise generation is reduced by grounding the external electrodes.

[0076]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a partially sectional front view showing a first embodiment of the dielectric barrier discharge lamp of the present invention.

FIG. 4 is a partially sectional front view showing the arc tube.

FIG. 5 is an enlarged sectional view of a principal part of a dielectric barrier discharge lamp schematically showing a state of the dielectric barrier discharge.

In each of the figures, LT is an arc tube, OT is an outer tube, B1 is a first base, B2 is a second base, and WH is a wire harness.

<Regarding the Arc Tube LT> The arc tube LT includes an airtight container 1, an internal electrode 2, an external electrode 3, and a pair of introduction wires 4, 4.

The hermetic container 1 is made of an ultraviolet-permeable material and has an elongated cylindrical hollow portion 1a and sealing portions 1b formed at both ends of the hollow portion 1a. The sealing portion 1b
It has a pinch seal structure in which molybdenum foil 1b1 is embedded.

An excimer generated gas is sealed in the hollow portion 1a of the airtight container 1.

The internal electrode 2 comprises a connecting portion 2a, a number of unit mesh portions 2b, and straight portions 2c at both ends. The connecting portion 2a is mainly composed of a coil 2a formed by winding a thin metal wire. The unit mesh portion 2b is
and a large number of ring-shaped portions arranged at a constant pitch.
Both end linear portions 2c are formed by extending both ends of the connecting portion 2a. The internal electrode 2 is connected to one end of the molybdenum foil 1b1 of the sealing portion 1b formed at both ends of the hermetic container 1 with a tension of about 2 kg applied thereto.
Is welding. The internal electrode 2 connecting portion 2a is
It is stretched by the action of tension while mounted inside.

The external electrode 3 has a mesh shape.
The airtight container 1 is composed of a plurality of turns of a coil formed by closely winding a metal wire on the outer surface at a constant pitch. Therefore, the unit mesh portion 3a is formed by each turn of the coil.

The pair of lead wires 4, 4 are welded at their inner ends to the molybdenum foil 1b1 embedded in the sealing portions 1b formed at both ends of the airtight container 1, and have their base ends extending from the sealing portion 1b to the outside. It is exposed.

<Regarding Outer Tube OT> The outer tube OT is composed of an elongated tube 5 and a reinforcing tube 6, and includes first and second tubes 5 to be described later.
The arc tube LT is housed in a coaxial relationship through the base bodies B1 and B2. The elongated tube 5 is made of an ultraviolet-transmissive material whose both ends are open. The reinforcing pipe 6 is made of a stainless steel pipe, and is attached to the outside of both ends of the elongated pipe 5.

<Regarding First Cap B1> The first cap B1 includes an insulating base 7 and a cap terminal 8. The insulating base 7 is fixed to the sealing portion 1b at one end of the arc tube LT with an inorganic adhesive, and one end of the outer tube OT is fitted to the outside thereof. Further, an exhaust port (not shown) communicating between the inside and the outside is formed in the insulating base 7. The base terminal 8 is supported by the central portion of the insulating base 7 and is connected to the external electrode 3 of the arc tube LT. A part of the base terminal 8 protrudes from the first base body B1 to the outside, and an ultraviolet irradiation device main body (not shown). ) Is configured to be grounded.

<Regarding the Second Cap B2> The second cap B2 comprises an insulating base 7 and a cap terminal (not shown), like the first cap B1. The insulating substrate 7
The other end of the arc tube LT is fixed to the sealing portion 1b at the other end by an inorganic adhesive, and the other end of the outer tube OT is fitted to the outside thereof. Further, an air supply port (not shown) communicating between the inside and the outside is formed in the insulating base 7. The base terminal is supported by the center of the insulating base 7 and is connected to the internal electrode 2 of the arc tube LT via one of the lead wires 4, and a part of the base terminal protrudes from the insulating base 7 to the outside. WH connects. Then, the second base B2 is on the high voltage side.

<Regarding the Wire Harness WH> The wire harness WH includes an insulated wire 9, a socket 10, and a connection terminal 11. The socket 10 is an insulated wire 9
Is connected to one end of the second base B2. The connection terminal 11 is connected to the other end of the insulated wire 9 and is connected to a high voltage output terminal of a high frequency lighting circuit (not shown).

<About the Lighting State> When the dielectric barrier discharge lamp is turned on by applying a high-frequency AC voltage between the internal electrode 2 and the external electrode 3, as shown by the density of black dots in FIG. A strong dielectric barrier discharge is generated around the plurality of unit mesh portions 2b of the internal electrode 2 to emit vacuum ultraviolet rays.

Example 1 (The structure is shown in FIGS. 3 and 4.) <Emission tube LT> Hermetic container 1: made of synthetic quartz glass, having an outer diameter of 18 mm,
1 mm in thickness, 650 mm in total length Internal electrode 2: The connecting portion 2a has a coil shape formed by winding a thin tungsten wire having a diameter of 0.2 mm with an outer diameter of 1.4 mm and a coil pitch of 0.4 mm. Unit mesh part 2b
Is made of a thin tungsten wire having a diameter of 0.2 mm, its outer diameter is 14 mm, and its pitch is 8 mm. The distance between the inner surface of the airtight container 1 and the unit mesh portion 2b is 1.0 mm.

Excimer product gas: Xenon at a pressure of about 50
Sealed at kPa.

External electrode 3: A nickel fine wire having a diameter of 0.2 mm was wound at a pitch of 2 mm to form a mesh having a plurality of turns of a coil. <Outer tube OT>: made of synthetic quartz glass, outer diameter 25 m
m, thickness 1.2 mm, length 750 mm, a nitrogen gas through type <lighting conditions> voltage between the electrodes: 2.5kVp-p, frequency 250 kHz, sine wave _{<D LI · P>: 128} <D OI -D LO >: 4.6 < _DOO / _DLO >: 1.4 FIG. 6 is a diagram schematically showing the state of the dielectric barrier discharge in the second embodiment of the dielectric barrier discharge lamp of the present invention. It is an expanded principal part sectional view of a lamp.

This embodiment is different in that the unit mesh portion 2b 'of the internal electrode 2 is formed of a spiral portion. Also in this embodiment, a dielectric barrier discharge is generated and vacuum ultraviolet rays are radiated in substantially the same manner as in FIG.

FIG. 7 is an enlarged cross-sectional view showing a third embodiment of the dielectric barrier discharge lamp according to the present invention.

FIG. 8 is an enlarged longitudinal sectional view of the main part.

FIG. 9 is a front view showing the arc tube.

In each figure, the same parts as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. The present embodiment is different in that a rod-shaped body 12 that short-circuits the unit mesh portion 3a of the external electrode 3 is provided.

That is, first, a rod-shaped body 12 made of nickel or the like is provided along the longitudinal direction of the surface of the airtight container 1, and a unit mesh portion 3a formed of a coil is formed thereon, and the external electrode 3 is provided. are doing. Since the unit mesh portion 3a is short-circuited by the rod-shaped body 12, the inductance and resistance of the unit mesh portion 3a become extremely small, and the influence on the ultraviolet intensity distribution is almost eliminated. Reference numeral 1c denotes an exhaust chip-off portion.
It is formed on the side surface in the middle part of FIG.

FIG. 10 is a partially omitted enlarged cross-sectional view showing a fourth embodiment of the dielectric barrier discharge lamp according to the present invention. In the figure, the same parts as those in FIG. In this embodiment, the heat pipe H
The difference is that P is used. The illustration of the internal electrodes and the external electrodes is omitted.

That is, a heat pipe H having a flat cross section
Three Ps are used, each having a length substantially equal to the entire length of the arc tube LT, and are provided along the longitudinal direction of the outer surface of the upper half in the figure of the arc tube and spaced apart from each other. Have been. And the heat absorption end is on the high temperature side of the arc tube LT,
Further, the heat radiating ends are similarly arranged on the low temperature side. The high temperature side of the arc tube LT is generated on the side from which nitrogen gas is discharged. The low temperature side is generated on the side to which the nitrogen gas is supplied. The symbol R in the figure is a reflection plate, and the heat pipe H
From above P, it covers almost the upper half of the arc tube LT in terms of heat conduction.

Embodiment 2 (The structure is shown in FIGS. 3, 4 and 10.) <Emission tube LT>: Same as in Embodiment 1. <Outer tube OT>: Made of synthetic quartz glass, outer diameter 28 m
m, wall thickness 1.2 mm, length 750 mm, nitrogen gas flow system <heat pipe>: width 5 mm, height 2 mm, length 600
mm <Reflector>: Aluminum, thickness 1 mm <Lighting condition> Nitrogen gas flow rate: 1 to 5 l / min Lamp power: 150 W FIG. 11 shows one embodiment of the dielectric barrier discharge lamp lighting device of the present invention. It is the partial section front view and a circuit diagram.

FIG. 12 is a partially sectional front view showing the arc tube.

In each figure, the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals, and description thereof is omitted.

The dielectric barrier discharge lamp lighting device includes a dielectric barrier discharge lamp DDL and a high frequency lighting circuit HFO.
The high voltage output terminal is connected to the connection terminal 11 of the wire harness WH, and the low voltage output terminal is grounded.

The dielectric barrier discharge lamp DDL differs in the size of the arc tube LT, the internal electrode 2 and the outer tube OT.

Embodiment 3 (The structure is shown in FIGS. 11 and 12.) <Dielectric barrier discharge lamp> Hermetic container 1: made of synthetic quartz glass, having an outer diameter of 12 mm,
1 mm in thickness, 650 mm in total length Internal electrode 2: The connecting portion 2a has a coil shape formed by winding a thin tungsten wire having a diameter of 0.2 mm with an outer diameter of 1.4 mm and a coil pitch of 0.4 mm. Unit mesh part 2b
Has a diameter of 9 mm and a pitch of 3 mm. The distance between the inner surface of the airtight container 1 and the unit mesh portion 2b is 0.5 mm.

Excimer generated gas: Xenon about 50 kPa External electrode 3: Nickel fine wire having a diameter of 0.2 mm
mm to form a mesh having a plurality of turns.

Outer tube OT: made of synthetic quartz glass, outer diameter 20 mm, wall thickness 1.2 mm, length 750 mm, nitrogen gas flow system <High frequency lighting circuit> Rectangular wave output inverter, frequency 70 kHz, output voltage 2
000 Vp-p <Lighting conditions> Lamp power: 50 W Nitrogen gas: 50 l / min at a supply temperature of 25 ° C. <Ultraviolet intensity>: Dielectric barrier discharge lamp having a unit mesh portion 2 b pitch of 12 mm and a lighting frequency of 25
Except for lighting at 0 kHz, output voltage of 2500 Vp-p, and sine wave alternating current, about twice the ultraviolet output was obtained as compared with the comparative example having the same specifications as the present example.

FIG. 13 is a graph showing the relationship between the pitch of the unit mesh portion of the internal electrode and the illuminance of ultraviolet light in the dielectric barrier discharge lamp lighting device according to one embodiment of the present invention, together with that of the comparative example. In the figure, the horizontal axis represents the axial distance (mm) of the airtight container, and the vertical axis represents the UV illuminance (relative value).
Are respectively shown. In the present embodiment, the distances 0, 3,
The unit mesh portions are located at 6, 9, 12, 15, 18, 21, and 24 mm. On the other hand, in the comparative example, the unit mesh portions are located at distances of 0, 12, and 24 mm. Curve A indicates the present invention, and curve B indicates a comparative example.

FIG. 14 is a cross-sectional view showing a main part of an ultraviolet cleaning apparatus as one embodiment of the ultraviolet irradiation apparatus of the present invention.

In the figure, 21 is a dielectric barrier discharge lamp, 22 is an ultraviolet irradiation device main body, and 23 is a work.

The dielectric barrier discharge lamp 21 has a structure employing any one of the embodiments shown in FIGS. 3 to 10, and a plurality of the barrier discharge lamps 21 are arranged at a short interval.
2, three of which are shown in the figure. The same parts as those in FIG. 3 are denoted by the same reference numerals.

The ultraviolet irradiation device main body 22 includes an aluminum block, and has a concave reflecting surface 22a on its lower surface and a cooling water flow passage 22b inside.

The dielectric barrier discharge lamp 21 has an outer tube OT
Is supported in thermal contact with the concave reflection surface 22a of the ultraviolet irradiation device main body 22, and the low-pressure side of the output end of the high-frequency lighting circuit (not shown) uses the ultraviolet irradiation device main body 22 as a conductive path and is externally connected. Connected to electrodes. In addition,
The ultraviolet irradiation device main body 22 is grounded.

The work 23 is a dielectric barrier discharge lamp 2
1 is moved from the lower side to the outer surface of the outer tube OT of the dielectric barrier discharge lamp 21 to a position of 3 mm so as to be able to receive ultraviolet irradiation.

[0115]

According to the first aspect of the present invention, a large number of elongated tubular airtight containers having an inner diameter of D _LI (mm), which are made of an ultraviolet-permeable material, are arranged at a pitch P (mm) in the axial direction. and FuSo internal electrodes forming a mesh-like and includes a unit mesh portion, the excimer product gas sealed in the airtight container, as well as disposed in the external electrode on the outer surface of the airtight container, D _LI ·
When P satisfies the following expression, it is possible to provide a dielectric barrier discharge lamp capable of obtaining high ultraviolet illuminance.

90 < _DLI · P <150 According to the second aspect of the present invention, an elongated tubular hermetic container made of an ultraviolet-permeable material having an outer diameter of D _LO (mm) extends in the axial direction to extend inside. an arc tube that is FuSo electrodes sealed excimer product gas were provided with external electrodes on the outer surface of the airtight container, an inner diameter for accommodating the arc tube comprises an outer tube of the elongated tubular of D _{OI (mm),} D _OI by -D _LO satisfies the following equation, it is possible to provide a dielectric barrier discharge lamp having a high ultraviolet intensity is obtained.

[0117] ₂ <According to the invention of D _{OI -D} LO <8 claim 3, the outer diameter extends in the axial direction of the elongated tubular airtight container made of an ultraviolet transparent material _D LO (mm) An arc tube in which an inner electrode is sealed, an excimer generated gas is sealed, and an outer electrode is disposed on an outer surface of an airtight container, and an elongate tubular outer tube having an outer diameter of _DOO (mm) for accommodating the arc tube is provided. When _DOO / _DLO satisfies the following expression, it is possible to provide a dielectric barrier discharge lamp capable of obtaining high ultraviolet illuminance.

[0118] _{1.2 <D OO / D LO <} 4 According to the invention of claim 4, excimer generated FuSo internal electrodes extend axially of the elongate tubular airtight container made of ultraviolet transmitting material An arc tube in which gas is sealed and an external electrode is arranged on the outer surface of the airtight container, a heat pipe arranged thermally conductive over substantially the entire outer surface of the arc tube, and an arc tube made of a material which is transparent to ultraviolet light, By providing an elongated tubular outer tube that accommodates and allows nitrogen gas to flow through, it is possible to provide a dielectric barrier discharge lamp in which uniformity of ultraviolet illuminance is improved and high ultraviolet illuminance is obtained. .

According to the fifth aspect of the present invention, in addition, a unit mesh in which the internal electrode is formed of a connecting portion extending substantially along the axis of the airtight container and a plurality of ring-shaped portions dispersedly provided in the connecting portion. By providing a mesh shape with a large number of portions, it is possible to provide a dielectric barrier discharge lamp in which the manufacture of the internal electrode is easy and the droop of the connecting portion is suppressed by the unit mesh portion.

According to the sixth aspect of the present invention, since the external electrode has a mesh shape composed of a plurality of turns of a coil, it is easy to manufacture the external electrode, and the vacuum ultraviolet rays emitted from the excimer are transmitted to the outside. It is possible to provide a dielectric barrier discharge lamp that can be easily led out and that increases ultraviolet radiation by the unit mesh portion.

According to the seventh aspect of the present invention, a dielectric barrier discharge lamp including an internal electrode including a mesh-like portion having a pitch of 4 mm or less in the axial direction of the airtight container, an internal electrode serving as an anode, and an external electrode serving as a cathode A high-frequency lighting circuit for supplying a high-frequency pulse so that the uniformity of the ultraviolet illuminance in the axial direction of the airtight container is significantly improved, and the ultraviolet illuminance is improved. Can be provided.

According to an eighth aspect of the present invention, there is provided the dielectric barrier discharge lamp according to any one of the first to sixth aspects, and an ultraviolet irradiation device main body provided with the dielectric barrier discharge lamp.
By providing the high frequency lighting circuit for lighting the dielectric barrier discharge lamp, it is possible to provide an ultraviolet irradiation device having the effects of claims 1 to 6.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between _DLI · P and ultraviolet illuminance using the outer diameter of an airtight container as a parameter.

2 is a graph showing the relationship between the outer diameter difference _D OI _{-D LO} and ultraviolet illumination

FIG. 3 is a partially sectional front view showing a first embodiment of the dielectric barrier discharge lamp of the present invention.

FIG. 4 is a partial cross-sectional front view showing the same arc tube.

FIG. 5 is an enlarged sectional view of an essential part of the dielectric barrier discharge lamp, also schematically showing a state of the dielectric barrier discharge.

FIG. 6 is an enlarged sectional view of an essential part of a dielectric barrier discharge lamp according to a second embodiment of the present invention, schematically showing a state of the dielectric barrier discharge in the second embodiment;

FIG. 7 is an enlarged cross-sectional view showing a third embodiment of the dielectric barrier discharge lamp of the present invention.

FIG. 8 is an enlarged longitudinal sectional view of a main part of the same.

FIG. 9 is a front view showing the arc tube.

FIG. 10 is an enlarged partial cross-sectional view showing a fourth embodiment of the dielectric barrier discharge lamp according to the present invention;

FIG. 11 is a partial sectional front view and a circuit diagram showing an embodiment of the dielectric barrier discharge lamp lighting device of the present invention.

FIG. 12 is a partial cross-sectional front view showing the same arc tube.

FIG. 13 is a graph showing a relationship between a pitch of a unit mesh portion of an internal electrode and ultraviolet illuminance in an embodiment of the dielectric barrier discharge lamp lighting device of the present invention, together with that of a comparative example.

FIG. 14 is an essential part cross-sectional view showing an ultraviolet cleaning device as one embodiment of the ultraviolet irradiation device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Airtight container 1a ... Hollow part 1b ... Sealing part 1b1 ... Molybdenum foil 2 ... Internal electrode 2a ... Connection part 2b ... Unit mesh part 3 ... External electrode 3a ... Unit mesh part 5 ... Slender tube 6 ... Protection tube 7 ... Insulation Base 8: Base terminal 9: Insulated wire 10: Socket 11: Connection terminal B1: First base B2: Second base LT: Arc tube OT: Outer tube WH: Wire harness

Continued on the front page (72) Inventor Kiyoshi Nishimura 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Litec Corporation (72) Inventor Akihiko Tauchi 5-2-1 Asahicho, Imabari City, Ehime Prefecture Toshiba Lighting Corporation

Claims (8)

[Claims] (1) It is made of a material that transmits ultraviolet light and has an inner diameter of D
A long and narrow tubular airtight container of _LI (mm); a large number of unit mesh portions are in the form of a mesh arranged at a pitch P (mm) in the axial direction of the airtight container; and FuSo internalization electrodes Te; and excimer generated gas sealed in the airtight container; and external electrodes disposed on an outer surface of the airtight container; equipped with, characterized in that D _{LI ·} P satisfies the following formula Dielectric barrier discharge lamp. 90 <D _LI · P <150 2. An elongated tubular airtight container made of an ultraviolet-permeable material having an outer diameter of D _LO (mm), an internal electrode sealed in the airtight container and extending in the axial direction of the airtight container, and an airtight container. An arc tube having an excimer product gas sealed therein and an external electrode disposed on the outer surface of the airtight container; and an elongated tubular outer tube having an inner diameter of _DOI (mm) for accommodating the arc tube. _and, a dielectric barrier discharge lamp, characterized in that D OI _{-D LO} satisfies the following equation. 2 _{<D OI -D} LO _<8 3. An elongated tubular hermetic container made of an ultraviolet-permeable material having an outer diameter of D _LO (mm), an internal electrode sealed in the hermetic container and extending in the axial direction of the hermetic container, and an hermetic container. An excimer product gas enclosed therein, and an arc tube having an external electrode disposed on the outer surface of the airtight container; and an elongated tubular outer tube having an outer diameter of _DOO (mm) for accommodating the arc tube. 1. A dielectric barrier discharge lamp, comprising: _DOO / _DLO satisfying the following expression. 1.2 < _DOO / _DLO <4 4. An elongated tubular hermetic container made of an ultraviolet-permeable material, an internal electrode sealed in the hermetic container and extending in the axial direction of the hermetic container, an excimer product gas sealed in the hermetic container, An arc tube provided with external electrodes disposed on the outer surface of the airtight container; a heat pipe disposed thermally conductive over substantially the entire outer surface of the arc tube; And a slender tubular outer tube through which nitrogen gas flows. 5. The internal electrode has a mesh shape including a connecting portion extending substantially along the axis of the airtight container and a unit mesh portion including a plurality of ring-shaped portions distributed in the connecting portion. The dielectric barrier discharge lamp according to any one of claims 1 to 4, wherein: 6. The dielectric barrier discharge lamp according to claim 1, wherein the external electrode has a mesh shape composed of a plurality of turns of a coil. 7. The airtight container according to claim 1, wherein a plurality of unit mesh portions are provided with mesh-shaped internal electrodes arranged at a pitch of 4 mm or less in the axial direction of the hermetic container via a gap. A high-frequency lighting circuit for supplying a high-frequency pulse to the dielectric barrier discharge lamp so that the internal electrode of the dielectric barrier discharge lamp functions as an anode and the external electrode functions as a cathode; A lighting device for a dielectric barrier discharge lamp, comprising: 8. A dielectric barrier discharge lamp according to any one of claims 1 to 6, an ultraviolet irradiation device main body provided with the dielectric barrier discharge lamp, and a high frequency lighting circuit for lighting the dielectric barrier discharge lamp. An ultraviolet irradiation device, comprising: