JP2002175781A - Discharge lamp and ultraviolet ray irradiating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance uniformity ratio of illuminance in a longitudinal direction of a discharge lamp of light irradiated from the discharge lamp. SOLUTION: The discharge lamp includes an external electrode 5 wound in a coil shape along a longitudinal direction of a sealed container 2 on an outer periphery of the sealed container 2, and a short-circuit electrode 6 arranged along the longitudinal direction of the sealed container 2 and being cross-contact with the external electrode 5, and the external electrode 5 wound in the coil shape is short-circuited by the short-circuit electrode 6. Thereby, generation of an inductance value in the longitudinal direction of the discharge lamp can be prevented, and the light irradiated from the discharge lamp increases the uniformity ratio of illuminance in the longitudinal direction of the discharge lamp.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a discharge lamp and an ultraviolet irradiation device using the discharge lamp.

[0002]

2. Description of the Related Art As an ultraviolet lamp that emits ultraviolet light,
Various dielectric barrier discharge lamps have been proposed. Such a dielectric barrier discharge lamp encloses a discharge medium (excimer generation gas) for generating excimer in an airtight discharge space, and also has a space inside the discharge space. A pair of electrodes is provided on the outside and a high voltage is applied between these electrodes to discharge. This discharge causes ultraviolet rays to be emitted from the discharge medium.

FIG. 9 is a front view showing an example of a conventional dielectric barrier discharge lamp. In FIG. 9, 101 is a cylindrical airtight container, 102 is an external electrode having conductivity,
103 is a conductive internal electrode; 104 is a sealing portion;
05 is a high frequency generation circuit. Xenon or the like as an excimer generating gas is sealed in the airtight container 101.

[0004] The hermetic container 101 is formed of a dielectric material that transmits ultraviolet light, for example, quartz or the like.

[0005] The external electrode 102 is mounted on the outer periphery of the airtight container 101 by being wound in a coil shape.

The internal electrode 103 is a conductive member having, for example, a coil shape, a bar shape, a linear shape, a plate shape, or the like, and is connected to a lead wire 106 fixed to a sealing portion 104.

The high-frequency generation circuit 105 includes an external electrode 102
A voltage is applied between the electrode and the internal electrode 103 to supply electric energy required for dielectric barrier discharge.

In the dielectric barrier discharge lamp having such a structure, when a voltage is applied between the external electrode 102 and the internal electrode 103 by the high-frequency generation circuit 105, a dielectric is generated between the external electrode 102 and the internal electrode 103. A body barrier discharge occurs. By this dielectric barrier discharge, the airtight container 1
The excimer-producing gas such as xenon sealed in the inside of O.sub.01 is temporarily bonded to a molecular state (excimer state). Then, when returning from the molecular state to the atomic base state, ultraviolet rays with little re-absorption are emitted. This is the light emission principle of the dielectric barrier discharge lamp.

[0009]

[Disconnection of External Electrode] The external electrode 1 wound in a coil shape as shown in FIG.
02 has a small wire diameter so as not to hinder the irradiation of ultraviolet rays transmitted through the airtight container 101. For this reason, an overcurrent may flow through the external electrode 102 during energization, and the external electrode 102 may be disconnected.

As the external electrodes, Japanese Patent Application Laid-Open No. 7-27
As described in Japanese Patent No. 2692, there is one using a seamless cylindrical wire mesh. However, when a cylindrical metal mesh is used as the external electrode, the structure of the external electrode becomes complicated and the cost increases. Furthermore, when a cylindrical wire mesh is used as the external electrode, the ratio of the emitted ultraviolet light that is shielded by the cylindrical wire mesh is high, and the adhesion to the airtight container is insufficient, and the irradiation performance of the ultraviolet light is poor. Become.

[Uniformity in the longitudinal direction of the dielectric barrier discharge lamp] When the external electrode 102 is wound around the outer periphery of the hermetic container 101, an inductance value is generated. In each part in the longitudinal direction, a part where dielectric barrier discharge is likely to occur and a part where dielectric barrier discharge is unlikely to occur occur, and the irradiation amount of ultraviolet rays in each part along the longitudinal direction of the hermetic container varies, and the length of the dielectric barrier discharge lamp increases. The uniformity of the illuminated light in the direction decreases.

[Power (Illuminance) of Dielectric Barrier Discharge Lamp] In order to increase the power of the dielectric barrier discharge lamp to increase the illuminance of ultraviolet rays, it is necessary to increase the applied voltage. However, in order to increase the applied voltage, the dielectric barrier discharge lamp must be redesigned for a high voltage.

An object of the present invention is to increase the uniformity of light emitted in the longitudinal direction of a discharge lamp.

[0014]

According to a first aspect of the present invention, there is provided a discharge lamp including an elongated tubular hermetic container mainly formed of a dielectric material; and an interior disposed in the hermetic container along a longitudinal direction thereof. An electrode; a linear external electrode wound in a coil shape along the longitudinal direction of the hermetic container; a short-circuit electrode arranged along the longitudinal direction of the hermetic container and cross-contacting with the external electrode; And a discharge medium sealed in an airtight container.

Therefore, when a voltage is applied between the external electrode and the internal electrode, a discharge occurs between the two electrodes and light is emitted from the discharge lamp. For example, when xenon is sealed as a discharge medium, xenon is temporarily bonded to a molecular state (excimer state) by a discharge between both electrodes,
When returning from the molecular state to the atomic ground state, light with little reabsorption is efficiently emitted, and the discharge lamp emits light. The wavelength range of the emitted light depends on the type of the discharge medium sealed in the airtight container. For example, when a large amount of xenon is sealed, ultraviolet light having a wavelength of 172 nm is emitted.

When an external electrode is wound around the outer periphery of the hermetic container, an inductance value is generated, and the generation of the inductance value causes a change in impedance. There is a portion that is difficult to perform, and the irradiation amount of light at each portion along the longitudinal direction of the airtight container varies, and the uniformity of the irradiated light in the longitudinal direction of the discharge lamp decreases.
However, by providing the short-circuit electrode along the longitudinal direction of the airtight container, the coil-shaped external electrode is short-circuited, and the occurrence of an inductance value can be prevented. This allows
The change in the impedance in the longitudinal direction of the discharge lamp can be eliminated, the discharge can be generated almost uniformly in the entire region in the longitudinal direction of the hermetic container, and the uniformity of the irradiated light in the longitudinal direction of the discharge lamp increases. . Note that the inductance value for one turn, which is considered to remain after being short-circuited, is a very small value, and therefore has little effect on the impedance in the lamp longitudinal direction. As described above, the discharge can be generated substantially uniformly in the entire area in the longitudinal direction of the lamp, and the uniformity of light emitted in the longitudinal direction of the discharge lamp is increased.

Further, it is considered that by arranging the short-circuit electrode along the longitudinal direction of the hermetic container, a discharge easily occurs between the short-circuit electrode and the internal electrode. This point will be described with reference to FIG. 2 which will be described in an embodiment described below. When three discharge paths A, B, and C are assumed (A is a discharge path at one end of which is a short-circuit electrode position). Impedance Z in each discharge path A, B, C
Is

[0018]

(Equation 1)

## EQU1 ## Here, R is the resistance value in the discharge space, L is the inductance value of the external electrode up to the position of each of the discharge paths A, B, and C. C is the capacitance ω of each of the discharge paths A, B, and C.

In FIG. 2, 3 is an internal electrode, 5 is an external electrode, 6 is a short-circuit electrode, and 2 is an airtight container.

Although the values of L and C are slightly different in each of the discharge paths A, B and C, as can be seen from the above equation, even if the values are slightly different, each of the discharge paths A , B, and C have almost no effect on the impedance Z, and the impedances of the discharge paths A, B, and C can be considered to be substantially the same. As a result, even when the short-circuit electrode 6 is provided, the discharge does not easily occur between the short-circuit electrode 6 and the internal electrode 3, which is the same as when the short-circuit electrode 6 is not provided. In addition, electric discharge occurs almost uniformly in the entire area of the hermetic container 2 in the circumferential direction.

According to a second aspect of the present invention, in the discharge lamp of the first aspect, the short-circuit electrode has a smaller electric resistance than the external electrode.

Therefore, since the electric resistance of the short-circuit electrode is smaller than the electric resistance of the external electrode, when a voltage is applied between the external electrode and the internal electrode, an overcurrent is prevented from flowing to the external electrode, and It is possible to prevent the external electrodes from being disconnected by overcurrent during lighting or the like.

According to a third aspect of the present invention, in the discharge lamp according to the first or second aspect, the tube diameter of the hermetic container is D.
mm, the wire diameter of the external electrode is d1 mm, and the winding pitch of the external electrode around the tubular portion of the hermetic container is hm.
When m, 0.05 ≦ d1 ≦ 0.9, 6 ≦ D ≦ 4
0, 10 <h / d1 <100.

Therefore, in a discharge lamp in which the tube diameter Dmm of the hermetic container is 6 ≦ D ≦ 40, the wire diameter d1 of the external electrode and the winding pitch h of the external electrode are set to 10 <h / d.
By defining the relationship of 1 <100, the light blocking ratio of the light emitted from the airtight container by the external electrode can be suppressed to 10% or less, and the light irradiation performance is favorably maintained.

In this regard, if h / d1 is 10 or less, for example, if the wire diameter d1 of the external electrode is 0.1 mm, the winding pitch dimension h will be 1 mm or less, and the external electrode emits light from the discharge lamp. Irradiation is greatly blocked, and the required light cannot be obtained.

Further, when h / d1 is 100 or more,
For example, when the wire diameter d1 of the external electrode is 0.1 mm,
The distance between adjacent external electrodes is as large as 10 mm or more, so that the creeping movement of the discharge hardly occurs. As a result, there arises a problem that the uniformity of the irradiated light in the longitudinal direction of the discharge lamp is significantly reduced.

Also, regarding the wire diameter d1 of the external electrode,
If the thickness is 0.05 mm or less, it becomes difficult for the current to flow.
When the diameter is 9 mm or more, the light-shielding rate increases.
By setting the wire diameter d1 of the external electrode to be 0.05 ≦ d1 ≦ 0.9, irradiation of light from the discharge lamp is performed well.

The invention described in claim 4 is the first to third aspects of the present invention.
The discharge lamp according to any one of the above, wherein constrictions are formed at both ends of the hermetic container, and the external electrode is wound around the constriction a plurality of times.

Therefore, loosening of the external electrode wound around the outer periphery of the airtight container is prevented, and deviation of the winding pitch dimension of the external electrode caused by such loosening is prevented.

[0031] The invention according to claim 5 provides the invention according to claims 1 to 4.
In the discharge lamp according to any one of the above, sealing portions that are pinch-sealed at both ends of the hermetic container are formed, and are inside the sealing portions at both ends of the hermetic container and head toward the sealing portion. It is characterized in that a rough surface portion is formed at the position of the inclined surface.

Therefore, the external electrode wound around the outer periphery of the airtight container is wound around the rough surface at the inclined surface toward the sealing portions formed at both ends thereof.
The wound external electrode is prevented from slipping along the inclined surface due to the large frictional resistance of the rough surface portion, and the wound state of the external electrode is stabilized.

The invention according to claim 6 is the invention according to claims 1 to 5
In the discharge lamp according to any one of the above, the internal electrode is disposed on a substantially central axis in the hermetic container, and an internal power supply electrode extending in the central axis direction, and an inner peripheral surface of the hermetic container. A plurality of conductive anchors formed in a ring shape along the central axis of the hermetic container and arranged at substantially equal intervals along the central axis direction of the hermetic container and connected to the internal power supply electrode.

Therefore, when the internal feeder electrode is going to hang down due to its own weight or the like, the conductive anchor comes into contact with and supports the inner peripheral surface of the airtight container, and the internal feeder electrode may droop greatly. Is prevented. And
By preventing the drooping, it is possible to prevent the distance between the internal electrode and the external electrode from largely fluctuating, and to cause a large fluctuation in the distance between the internal electrode and the external electrode. It is possible to prevent the formation of a portion and to generate a discharge almost uniformly in the entire region in the longitudinal direction of the hermetic container, thereby increasing the uniformity of the irradiated light in the longitudinal direction of the discharge lamp.

In addition, since the conductive anchor is provided, the distance between the conductive anchor, which is a part of the internal electrode, and the inner peripheral surface of the hermetic container, which is a dielectric, is shortened. Creepage discharge is likely to occur, and startability is improved, so that the starting voltage and the lighting maintenance voltage can be reduced.

According to a seventh aspect of the present invention, in the discharge lamp of the sixth aspect, the wire diameter of the external electrode is d1m.
m, wherein when the pitch dimension of the conductive anchor is Hmm, 100 <H / d1 <300.

Accordingly, by defining the wire diameter dimension d1 of the external electrode and the pitch dimension H of the conductive anchor as described above, the conductive anchors are arranged at appropriate intervals, and the inner circumference of the hermetic container is kept. The generation of creeping discharge along the surface is promoted, and the discharge can be stably generated.

On the other hand, when H / d1 is 100 or less, for example, when the wire diameter d1 of the external electrode is 0.1 mm, the pitch H of the conductive anchors becomes 10 mm or less, and the conductive anchors between the conductive anchors become conductive. Occupied by the conductive anchor increases, the undischarged portion which is the area occupied by the conductive anchor increases, and illuminance lowering and illuminance unevenness occur.

When H / d1 is 300 or more, for example, when the wire diameter d1 of the external electrode is 0.1 mm, the pitch H of the conductive anchor becomes 30 mm or more, which is large. Therefore, a needle-like discharge other than the creeping discharge is likely to occur, and the illuminance becomes uneven, so that the uniformity of the irradiated light in the longitudinal direction of the discharge lamp cannot be maintained.

The invention described in claim 8 is the first to seventh aspects.
The discharge lamp according to any one of the above, wherein the short-circuit electrode is arranged in the vicinity of a chip portion present on an outer peripheral portion of the airtight container.

Therefore, the short-circuit electrode and the tip portion hinder the light emitted from the airtight container. However, these tip portions and the short-circuit electrode are arranged close to each other, and the short-circuit electrode and the tip portion are not required to be irradiated with light. By arranging them, the irradiation of light from the discharge lamp can be maintained in a good state. Further, this chip portion can be used as a positioning reference when arranging the short-circuit electrode.

The ninth aspect of the present invention provides the first to eighth aspects.
The discharge lamp according to any one of the above, wherein a plurality of the short-circuit electrodes are provided.

Therefore, it is possible to more reliably prevent the overcurrent from flowing to the external electrode, and it is possible to more reliably prevent the disconnection of the external electrode due to the overcurrent.

According to a tenth aspect of the present invention, in the discharge lamp according to any one of the first to ninth aspects, a lead wire for energizing the external electrode is connected to the short-circuit electrode.

Therefore, it is possible to prevent the entire lamp current from flowing only to the external electrode at the connection portion with the lead wire, thereby preventing disconnection of the external electrode due to overcurrent.

According to an eleventh aspect of the present invention, in the discharge lamp according to any one of the first to tenth aspects, a tubular outer tube formed of a light-transmitting material and covering the airtight container is provided. It is characterized by the following.

Therefore, the light emitted from the airtight container passes through the outer tube and is irradiated. Further, by providing the outer tube, dirt is prevented from being attached to the outer electrode wound around the outer periphery of the airtight container, and metal ions released from the outer electrode are attached to surrounding members. Is prevented.

According to a twelfth aspect of the present invention, there is provided an ultraviolet irradiation apparatus, comprising: a plurality of the discharge lamps according to the eleventh aspect; and a holding case for holding the plurality of the discharge lamps close to each other so that their central axes are parallel. And;

Therefore, according to this ultraviolet irradiation apparatus, the discharge lamp is irradiated with ultraviolet rays by appropriately selecting a discharge medium in the discharge lamp according to any one of claims 1 to 10, and the discharge lamp is described in claim 11 The same operation and effect as when the outer tube is provided. Further, since the discharge lamp directly faces the object to be irradiated with the ultraviolet light, the irradiation of the object with the ultraviolet light can be efficiently performed. Irradiation of ultraviolet light can be performed efficiently even on an irradiation target that has not been irradiated.

Here, in the present invention, definitions and technical meanings of the terms are as follows unless otherwise specified.

[Airtight Container] An airtight container mainly formed of a dielectric material can be generally manufactured using quartz glass. As a dielectric material, the dielectric constant ε
Means that 3.0 <ε <10, and the dielectric constant ε of quartz glass is 3.8.

The airtight container may be a tubular one, and may be not only a straight tube but also a curved one.

[Internal Electrode] The internal electrode is made of a heat-resistant metal such as nickel, tungsten, molybdenum, or the like.
It is formed from a metal such as stainless steel or titanium. The shape may be a rod shape, a linear shape, a plate shape, or the like, but may be a structure having an internal feeder electrode and a conductive anchor as in the invention according to claim 5.

[External Electrode] The external electrode acts to generate a discharge between itself and the internal electrode, and emits light by the discharge. As the structure of the external electrode, it is wound in a coil shape around the outer periphery of the airtight container.

It is desirable that the external electrode has a wire diameter and a winding pitch such that the light shielding ratio of light emitted to the outside of the airtight container can be suppressed to 10% or less.

Such an external electrode can be formed using a suitable metal, for example, stainless steel, nickel, silver, gold, platinum, or the like.

[Short-circuit electrode] The short-circuit electrode is disposed in the longitudinal direction of the airtight container. Regarding the arrangement state of the short-circuit means, it may be arranged so as to be in contact with the outer peripheral surface of the airtight container, and the external electrode may be wound thereover to make cross contact with the external electrode, or the external electrode is wound around the airtight container. It may be cross-contacted with an external electrode by attaching it later. Also, when the short-circuit electrode and the airtight container are brought into contact, the larger the contact area, the larger the capacitance of the discharge lamp as shown by the equivalent circuit of the capacitive load. The power of the discharge lamp can be increased without increasing the illuminance of light emitted from the discharge lamp.

Such a short-circuit electrode is arranged on the side which does not hinder the light irradiated to the outside of the airtight container.

Such a short-circuit electrode can be formed using an appropriate metal, for example, stainless steel, nickel, silver, gold, platinum or the like.

The electric resistance of such a short-circuit electrode is set to be smaller than the electric resistance of the external electrode. Means for making the electric resistance of the short-circuit electrode smaller than the electric resistance of the external electrode include making the cross-sectional area of the short-circuit electrode smaller than the cross-sectional area of the external electrode, or forming the short-circuit electrode with a material having a lower electric resistance. Is mentioned.

The shape of the short-circuit electrode may be a round bar, a plate,
A plate shape having a crescent cross section may be used.

The number of short-circuit electrodes may be one or a plurality of short-circuit electrodes may be provided.

[Discharge Medium] The discharge medium is a medium that generates a discharge when a voltage is applied, and a typical example thereof is an excimer generated gas. The excimer product gas is mainly composed of xenon, and this xenon is mixed with a rare gas alone such as krypton, argon, neon or a mixed gas of a rare gas and a halogen such as fluorine, chlorine, bromine or iodine. Can be used. Such a filling pressure of the discharge medium affects the output of the emitted light and the startability. That is, the output of the emitted light increases as the filling pressure of the discharge medium increases, but the starting voltage and the lighting voltage increase. For example, a pressure of 10 to 70 kPa is appropriate as the pressure at which the discharge medium is filled.

[Outer tube] The outer tube is made of a material having light transmittance,
For example, it is formed of quartz glass. The outer tube is formed to have a size surrounding the airtight container. A space between the outer peripheral surface of the hermetic container and the inner peripheral surface of the outer tube is used as a cooling medium, a flow path of an inert gas used as a medium for preventing light such as irradiated ultraviolet light from being absorbed by oxygen. It may be.

[0065]

FIG. 1 shows a first embodiment of the present invention.
A description will be given based on FIG. FIG. 1 is a longitudinal sectional front view showing a dielectric barrier discharge lamp, FIG. 2 is a longitudinal sectional side view thereof, and FIG. 3 is a front view and a plan view showing an end of an airtight container.

As shown in FIG. 1, a dielectric barrier discharge lamp 1, which is a discharge lamp, includes an airtight container 2, an internal electrode 3, a lead wire 4 connected to the internal electrode 3, an external electrode 5, a short-circuit electrode 6, and an external electrode. It is formed by a tube 7 and the like.

The hermetic container 2 is made of quartz glass and has an outer diameter (tube diameter D) of 12 mm and an inner diameter of 10 mm.
And an elongated cylindrical hollow portion 2a, and sealing portions 2b formed at both ends of the hollow portion 2a. The sealing portion 2b has a pinch seal structure in which a molybdenum foil 8 is embedded.

Xenon is sealed in the hollow portion 2a of the hermetic container 2 as a main component of the excimer generation gas as a discharge medium. If necessary, 5 to 50% of a rare gas such as argon or neon can be sealed. The sealing pressure is 10 to 70 kPa.

The internal electrode 3 is formed of tungsten having a wire diameter of 1.0 mm and has a length “L” of 1000.
mm. As a material for the internal electrode 3, a heat-resistant metal such as nickel and molybdenum can be used in addition to tungsten. The internal electrode 3 is an airtight container 2
Of the airtight container 2
Of the molybdenum foil 8
And sealed and fixed by the sealing portion 2b.

The external electrode 5 has a wire diameter "d1" of 0.1 mm.
Metal such as stainless steel is wound around the outer periphery of the hermetic container 2 in a coil shape, and is wound in a coil shape at a pitch of 1 to 2 mm at a winding pitch “h” at a tubular portion of the hermetic container 2. It is installed. As a result, “h / d1” becomes 10 <h / d1 <20, and the ratio (opening ratio) of the portion of the hermetic container 2 that is not covered with the external electrode 5 is set to 90 to 95%.

A constricted portion 9 is formed at both ends of the airtight container 2 and at a boundary between the hollow portion 2a and the sealing portion 2b (see FIG. 3B). This constricted portion 9 has an external electrode 5
Of the airtight container 2 is wound several times.
Of the external electrode 5 wound around the outer periphery of the external electrode 5 is prevented, and the deviation of the winding pitch dimension of the external electrode 5 caused by such loosening is prevented.

Further, both ends of the hermetic container 2 and portions from the hollow portion 2a to the sealing portion 2b are inclined surfaces, and a rough surface portion 10 is formed at this inclined surface. (A)). The rough surface portion 10 is formed by applying aluminum powder or performing a surface roughening process. Thereby, even when the external electrode 5 is wound around the inclined surface, the external electrode 5
Is prevented from slipping along the inclined surface due to a large frictional resistance with the rough surface portion 10, and the wound state is stably maintained.

The short-circuit electrode 6 is arranged along the longitudinal direction (center axis direction) of the hermetic container 2 in contact with the outer peripheral surface of the hermetic container 2. Further, the external electrode 5 is wound around the short-circuit electrode 6 together with the airtight container 2, and the short-circuit electrode 6 and the external electrode 5 intersect and are electrically connected at many points along the longitudinal direction of the airtight container 2. ing. The short-circuit electrode 6 has a wire diameter of 1.0 mm, and has a cross-sectional area larger than that of the external electrode 5. Since the cross-sectional area of the short-circuit electrode 6 is wider than the cross-sectional area of the external electrode 5, when the short-circuit electrode 6 and the external electrode 5 are formed of the same material, the electric resistance of the short-circuit electrode 6 is smaller.

The outer peripheral surface of the hermetic container 2
There is a tip portion 11 which is the remaining portion of the tube portion used for discharging the residual gas inside and for injecting the excimer generation gas into the hermetic container 2 during the production of. The short-circuit electrode 6 is arranged near the chip portion 11.

The outer tube 7 is a member formed of a straight pipe-shaped quartz glass having an outer diameter dimension of 17.5 mm, and has a size such that a predetermined gap is formed between the outer tube 7 and the outer peripheral surface of the airtight container 2. Is used. This gap portion is formed in a flow path space 1 through which an inert gas such as a nitrogen gas or an argon gas described later flows.
It is 2. At both ends of the outer tube 7, a pair of plugs 13a, which hermetically seal the outer tube 7 while the airtight container 2 is housed,
13b is welded. An inlet 14 through which nitrogen gas flows into the channel space 12 is formed in one plug 13a, and an outlet 15 through which nitrogen gas flows out from the channel space 12 is formed in the other plug 13b. ing.

An inert gas circulation mechanism (not shown) for circulating nitrogen gas at a predetermined flow rate is connected between the inlet 14 and the outlet 15. This inert gas circulation mechanism includes a pipe connected between the inlet 14 and the outlet 15,
It is composed of a storage tank, a fluid pump and the like provided in the middle of the pipe for storing nitrogen gas.

The sockets 16a and 16b are attached to the plugs 13a and 13b, respectively. The lead wire 4 of the internal electrode 3 is provided through the sockets 16a and 16b, and a lead wire 17 for supplying electricity to the external electrode 5 is conducted to one of the sockets 16b. Since the end of the lead wire 17 is connected to the short-circuit electrode 6, the lamp current is prevented from flowing only to the external electrode 5 at the connection portion with the lead wire 17, and the external electrode 5 due to overcurrent is prevented.
Disconnection is prevented.

In such a configuration, when a voltage is applied between the external electrode 5 and the internal electrode 3, a dielectric barrier discharge occurs between the electrodes 3 and 5. Thereby, the airtight container 2
The excimer-produced gas enclosed in the gas temporarily combines into a molecular state (excimer state), and when returning from such a molecular state to the ground state of atoms, ultraviolet light with little re-absorption is efficiently emitted, and a dielectric barrier discharge occurs. The lamp 1 emits light. The wavelength range of the emitted ultraviolet light depends on the type of excimer-producing gas sealed in the hermetic container 2. For example, when a large amount of xenon is sealed, ultraviolet light having a wavelength of 172 nm is emitted.

Here, in order not to hinder the irradiation of ultraviolet rays from the dielectric barrier discharge lamp 1, it is desirable to make the external electrode 5 thin. However, this external electrode 5
If the width is too small, a break may occur when an overcurrent flows. However, in the dielectric barrier discharge lamp 1, the provision of the short-circuit electrode 6 prevents a part of the current from flowing through the short-circuit electrode 6, thereby preventing an overcurrent from flowing to the external electrode 5, and Disconnection of the external electrode 5 can be prevented.

When the external electrode 5 is wound around the outer periphery of the hermetic container 2, an inductance value is generated, and the generation of the inductance value causes a change in impedance.
In each part of the hermetic container 2 in the longitudinal direction, a portion where the dielectric barrier discharge easily occurs and a portion in which the dielectric barrier discharge is less likely to occur, and the irradiation amount of the ultraviolet rays varies in each portion along the longitudinal direction of the hermetic container 2. The uniformity of the ultraviolet rays irradiated in the longitudinal direction of the discharge lamp 1 decreases. However, by providing the short-circuit electrode 6 along the longitudinal direction of the airtight container 2, the external electrode 5 wound in a coil shape is short-circuited, and the inductance value can be prevented. As a result, it is possible to eliminate a change in the impedance of the dielectric barrier discharge lamp 1 in the longitudinal direction, and to generate a dielectric barrier discharge substantially uniformly in the entire region in the longitudinal direction of the hermetic container 2. 1, the uniformity of the ultraviolet rays irradiated in the longitudinal direction is increased.

The dielectric barrier discharge lamp 1 is a capacitive load composed of a resistance value, which is a part of the discharge space, and a capacitor capacity, which is a part of the hermetic container 2, as represented by an equivalent circuit. When the voltage increases, the power of the dielectric barrier discharge lamp 1 can be increased without increasing the applied voltage, and the illuminance of ultraviolet rays emitted from the dielectric barrier discharge lamp can be increased. And
The capacitance of the capacitor increases as the contact area between the external electrode 5 and the short-circuit electrode 6 which is a part of the external electrode and the hermetic container 2 increases. That is, by providing the short-circuit electrode 6, the power of the dielectric barrier discharge lamp 1 can be increased without increasing the applied voltage, and the illuminance of the ultraviolet light emitted from the dielectric barrier discharge lamp can be increased.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be described based on. The same portions as those described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted (the same applies to the following embodiments). FIG. 4 is a vertical sectional side view showing the dielectric barrier discharge lamp 1a.

Dielectric barrier discharge lamp 1 of the present embodiment
The basic structure of a is the same as the structure of the dielectric barrier discharge lamp 1 of the first embodiment, and the different part is the number of provided short-circuit electrodes 6. In the present embodiment, three short-circuit electrodes 6 are arranged along the longitudinal direction of the hermetic container 2 so as to be in contact with the outer peripheral surface of the hermetic container 2, and around these three short-circuit electrodes 6. An external electrode 5 is wound therearound. The three short-circuit electrodes 6 are arranged at intervals of approximately 90 °, and one in the center is arranged near the chip portion 11.

In such a configuration, by increasing the number of short-circuit electrodes 6, it is possible to more reliably prevent an overcurrent from flowing to the external electrode 5, and to more reliably prevent disconnection of the external electrode 5 due to the overcurrent. Can be prevented.

Further, by increasing the number of short-circuit electrodes 6, the contact area between short-circuit electrode 6, which is a part of the external electrode, and hermetic container 2 is increased, and dielectric barrier discharge lamp 1a is connected to an equivalent circuit of a capacitive load. Since the capacitance of the capacitor in the case indicated by increases, the power of the dielectric barrier discharge lamp 1a can be further increased without increasing the applied voltage, and the illuminance of the ultraviolet light emitted from the dielectric barrier discharge lamp 1a can be reduced. It can be further improved.

Next, a third embodiment of the present invention will be described with reference to FIG.
7 will be described with reference to FIG. FIG. 5 is a vertical sectional front view showing the dielectric barrier discharge lamp 1b, FIG. 6 is a vertical sectional side view thereof, and FIG. 7 is a vertical sectional front view showing a part thereof in an enlarged manner.

Dielectric barrier discharge lamp 1 of the present embodiment
The basic structure of “b” is the same as that of the dielectric barrier discharge lamp 1 of the first embodiment, and the difference is the structure of the internal electrode 18. The internal electrode 18 is one internal feeder electrode 1
8a, a plurality of conductive anchors 18b, and connecting wire portions 18c
Are formed.

The internal power supply electrode 18a is made of a heat-resistant metal such as nickel, tungsten, molybdenum, or the like.
A wire rod having a diameter of 0.1 mm made of a metal such as stainless steel or titanium is formed into a coil having an outer diameter of 1.2 mm at a pitch of 1 mm.
The airtight container 2 is formed by being wound at about 00%, is disposed on a substantially central axis along the longitudinal direction of the airtight container 2, and both ends thereof are connected to the molybdenum foil 8 and sealed and fixed by the sealing portion 2b.

The conductive anchors 18b are formed by rolling a wire having the same material as the internal feeder electrode 18a and having a diameter of 0.31 mm into a ring shape having an outer diameter of 9.0 mm. Each is connection line 1
8c is connected to the internal feeder electrode 18a. The pitch dimension "H" of each conductive anchor 18b along the longitudinal direction of the airtight container 2 is set to 12 mm. Also,
As described in the first embodiment, the wire diameter “d1” of the external electrode 5 is 0.1 mm, and the winding pitch dimension “h” of the external electrode 5 is 1 to 2 mm. Accordingly, the ratio of the wire diameter dimension “d1” of the external electrode 5 to the pitch dimension “H” of the conductive anchor 18b is defined as “H / d1 = 120”.

In such a configuration, since the internal electrode 18 is formed by the internal power supply electrode 18a, the conductive anchor 18b, and the connection line portion 18c, the internal power supply electrode 18a is caused by its own weight or thermal expansion at the time of lighting. When it hangs down, the conductive anchor 18b comes into contact with and supports the inner peripheral surface of the airtight container 2, and the inner power supply electrode 18
a is prevented from drooping greatly. Further, since the internal power supply electrode 18a is formed in a coil shape, the expansion due to thermal expansion can be absorbed by the internal power supply electrode 18a itself, and the internal power supply electrode 18a can be further prevented from sagging due to thermal expansion. Can be.

As a result, a large variation in the distance between the internal electrode 18 and the external electrode 5 can be prevented, and a discharge occurs due to a large variation in the distance between the internal electrode 18 and the external electrode 5. It is possible to prevent a portion that is easy to generate and a portion that is unlikely to be generated, and to prevent a variation in light distribution in the longitudinal direction of the hermetic container 2, thereby increasing the degree of uniformity of ultraviolet rays irradiated in the longitudinal direction of the hermetic container 2.

Further, since the conductive anchors 18b have a uniform pitch, the distance between the conductive anchors 18b, which are a part of the internal electrodes 18, and the inner peripheral surface of the hermetic container 2, which is a dielectric, is reduced. And the conductive anchor 17
b and the external electrode 5 become uniform, so that the airtight container 2
, A dielectric barrier discharge (creepage dielectric barrier discharge) easily propagates along the inner peripheral surface of the substrate, thereby improving the startability, and reducing the starting voltage and the lighting maintenance voltage.

The ratio of the wire diameter “d1” of the external electrode 5 to the pitch “H” of the conductive anchor 17b is “H /
Since d1 = 120 ″, the conductive anchors 17b are arranged at appropriate intervals, and the generation of the creepage dielectric barrier discharge is promoted, and the dielectric barrier discharge can be stably generated. it can.

In this embodiment, as in the first embodiment, the short-circuit electrode 6 in contact with the outer peripheral surface of the hermetic container 2 is arranged along the longitudinal direction of the hermetic container 2. In the same manner as in the embodiment, the operation and effect of providing the short-circuit electrode 6, specifically, preventing disconnection of the external electrode 5 due to overcurrent, irradiating in the longitudinal direction of the dielectric barrier discharge lamp 1 b And the power of the dielectric barrier discharge lamp 1b is increased.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
It will be described based on. FIG. 8 is a sectional view showing the ultraviolet irradiation device 21.

The ultraviolet irradiation device 21 applies a voltage to the plurality of dielectric barrier discharge lamps 1, a holding housing 22 holding these dielectric barrier discharge lamps 1, and each of the dielectric barrier discharge lamps 1. The high frequency generating circuit 23 includes an inert gas circulation mechanism (not shown) that circulates nitrogen gas to the flow path space 12 of each dielectric barrier discharge lamp 1.

The holding case 22 is formed by a storage case 24 and a cooling block 25. Cooling block 25
Are formed with a plurality of storage recesses 26, and one dielectric barrier discharge lamp 1 is fitted into each of the storage recesses 26. These dielectric barrier discharge lamps 1 are held close to each other so that their central axes are parallel. Specifically, when the outer diameter of the outer tube 7 is 17.5 mm, the dielectric barrier discharge lamps 1 are arranged so that the distance between adjacent dielectric barrier discharge lamps 1 is 2.5 mm. In the cooling block 25, a cooling water channel 27 through which cooling water flows is formed. The storage case 24 is used as a conductive member for grounding, and stores the dielectric barrier discharge lamp 1 in the storage recess 26.
The socket 16b (see FIG. 1) is electrically connected to ground when it is fitted in the socket. An object 28 to be irradiated with ultraviolet rays is arranged at a position in the ultraviolet irradiation device 21 facing the direction in which ultraviolet rays are emitted from the plurality of dielectric barrier discharge lamps 1.

In such a configuration, when the object to be irradiated 28 is irradiated with ultraviolet rays by the ultraviolet irradiation device 21, as shown in FIG. The object to be irradiated 28 is arranged at a position to be driven, and the high frequency generation circuit 23 is driven.

By driving the high-frequency generation circuit 23, ultraviolet rays are emitted from the dielectric barrier discharge lamp 1 based on the above-described light emission principle, and the ultraviolet rays transmitted through the airtight container 2 and the outer tube 7 impinge on the surface of the irradiation object 28. As a result, the surface is cleaned.

Here, the dielectric barrier discharge lamp 1 has a double tube structure including the airtight container 2 and the outer tube 7, and can prevent dirt from adhering to the outer electrode 5. Further, it is possible to prevent metal ions jumping out of the external electrode 5 from adhering to the irradiation object 28. And the dielectric barrier discharge lamp 1
Can be brought close to the irradiation object 28, so that the irradiation of the irradiation object 28 can be performed efficiently.

Further, in the ultraviolet irradiation apparatus 21, since a plurality of dielectric barrier discharge lamps 1 are arranged close to each other, it is possible to make the irradiation amount of the ultraviolet light substantially uniform at each part of the surface of the object 28 to be irradiated. And the cleaning performance by ultraviolet irradiation can be improved.

In the dielectric barrier discharge lamp 1, a passage space 1 is provided between the outer peripheral surface of the hermetic container 2 and the inner peripheral surface of the outer tube 7.
2 is formed, and nitrogen gas, which is an inert gas, is flown into the flow path space 12. The nitrogen gas can remove the air from the flow path space 12 and is contained in the air. It is possible to prevent the ultraviolet rays irradiated by the oxygen being absorbed from being absorbed. In addition, the dielectric barrier discharge lamp 1 can be cooled by the nitrogen gas, the temperature can be prevented from rising due to heat at the time of light emission, and a decrease in the luminous efficiency of ultraviolet rays due to the temperature rise can be prevented, so that a high luminous efficiency can be maintained. .

According to the ultraviolet irradiation device 21,
Since the dielectric barrier discharge lamp 1 directly faces the object 28 to be irradiated with ultraviolet rays, a plurality of dielectric barrier discharge lamps 1 are arranged in a shape following the irregularities on the surface of the object 28. Thereby, ultraviolet irradiation can be efficiently performed even on the irradiation object 28 that is not planar.

The ultraviolet irradiation device 21 of the present embodiment
In the above, the case where the dielectric barrier discharge lamp 1 described in the first embodiment is used has been described as an example. However, the dielectric barrier discharge lamp 1 is replaced with the dielectric barrier discharge lamp 1 and described in the second embodiment. The dielectric barrier discharge lamp 1a or the dielectric barrier discharge lamp 1b described in the third embodiment may be used.

[0105]

According to the discharge lamp of the first aspect of the present invention, the outer electrode wound around the outer periphery of the hermetic container in a coil shape along the longitudinal direction thereof, and the outer electrode is formed on the hermetic container along the longitudinal direction of the hermetic container. Since the external electrode is wound around the outer periphery of the hermetic container when the outer electrode is wound around the outer periphery of the hermetic container, an inductance value is generated, and the uniformity of light irradiated in the longitudinal direction of the hermetic container is reduced. As a cause, by providing a short-circuit electrode along the longitudinal direction of the hermetic container, it is possible to prevent the occurrence of an inductance value by short-circuiting the coil-shaped external electrode, thereby reducing the impedance in the longitudinal direction of the discharge lamp. It is possible to stably generate a discharge in the entire region in the longitudinal direction of the hermetic container without change, and to increase the uniformity of light irradiated in the longitudinal direction of the hermetic container. Kill.

According to the second aspect of the present invention, in the discharge lamp according to the first aspect, since the short-circuit electrode has lower electric resistance than the external electrode, the external electrode can be applied when a voltage is applied between the external electrode and the internal electrode. Overcurrent can be prevented from flowing to the external electrode, and disconnection of the external electrode due to the overcurrent can be prevented.

According to the third aspect of the present invention, in the discharge lamp according to the first or second aspect, the tube diameter of the hermetic container is D mm, the wire diameter of the external electrode is d1 mm, and the outside of the hermetic container is connected to the tubular portion. When the winding pitch dimension of the electrode is hmm, 0.05 ≦ d1 ≦ 0.9, 6 ≦ D ≦ 40, 10 <h
/ D1 <100, so that 6 ≦ D ≦
In the airtight container 40, the light blocking ratio of the light emitted from the airtight container by the external electrode can be suppressed to 10% or less, and the light irradiation performance can be maintained well. In addition, by defining as above, it is possible to prevent the pitch interval of the external electrodes from being too large, to promote the generation of creeping discharge along the inner peripheral surface of the airtight container, and to stably generate the discharge. Thus, it is possible to easily maintain the current flowing through the external electrodes.

According to the fourth aspect of the present invention, in the discharge lamp according to any one of the first to third aspects, constrictions are formed at both ends of the hermetic container, and the external electrode is wound around the constriction a plurality of times. Therefore, loosening of the external electrode wound around the outer periphery of the airtight container can be prevented, and deviation of the winding pitch dimension of the external electrode caused by such loosening can be prevented.

According to the fifth aspect of the present invention, in the discharge lamp according to any one of the first to fourth aspects, pinch-sealed sealing portions are formed at both ends of the hermetic container, and both ends of the hermetic container are provided. Since the rough surface portion is formed at the position of the inclined surface toward the sealing portion, the external electrode is wound around the rough surface portion at the position of the inclined surface toward the sealing portion formed at both ends of the hermetic container. Accordingly, it is possible to prevent the external electrode wound around the inclined surface from slipping along the inclined surface due to the large frictional resistance, and to stabilize the winding state of the external electrode.

According to the sixth aspect of the present invention, in the discharge lamp according to any one of the first to fifth aspects, the internal electrode is disposed on a substantially central axis in the airtight container and extends in the central axis direction. And a plurality of inner feeder electrodes connected to the inner feeder electrode which are formed in a ring shape along the inner peripheral surface of the hermetic container and are arranged at substantially equal intervals along the central axis direction of the hermetic container. Since the conductive power anchor has a conductive anchor, the conductive power anchor will come into contact with and support the inner peripheral surface of the airtight container when the internal power feeder electrode is going to hang down due to its own weight or the like. It can be prevented from drooping greatly. And, by preventing the sag, the distance between the internal electrode and the external electrode can be prevented from being greatly varied, and a portion where the discharge is likely to occur due to a large variation between the internal electrode and the external electrode is generated. It is possible to prevent the formation of a portion that is difficult to perform, and it is possible to generate a discharge substantially uniformly in the entire region in the longitudinal direction of the hermetic container, and it is possible to increase the uniformity of irradiated light in the longitudinal direction of the hermetic container. Also, by having the conductive anchor, the distance between the conductive anchor, which is a part of the internal electrode, and the inner peripheral surface of the hermetic container is reduced, so that creeping discharge along the inner peripheral surface of the hermetic container easily occurs, The startability can be improved, and the starting voltage and the lighting maintenance voltage can be reduced.

According to the seventh aspect of the present invention, in the discharge lamp according to the sixth aspect, the wire diameter of the external electrode is d1m.
m, when the pitch dimension of the conductive anchor is Hmm,
Since 100 <H / d1 <300, the conductive anchors are arranged at appropriate intervals by defining as described above, and the generation of creeping discharge along the inner peripheral surface of the airtight container is prevented. The discharge can be promoted, and the discharge can be generated stably.

According to the eighth aspect of the present invention, in the discharge lamp according to any one of the first to seventh aspects, the short-circuit electrode is arranged in the vicinity of the tip portion present on the outer peripheral portion of the airtight container. Although the short-circuit electrode and the tip block the light emitted from the airtight container, the discharge lamp is arranged by arranging the tip and the short-circuit electrode in the vicinity and on the side where the light does not need to be irradiated. Irradiation of light can be maintained in a good state. Further, this chip portion can be used as a positioning reference when arranging the short-circuit electrode.

According to the ninth aspect of the present invention, in the discharge lamp according to any one of the first to eighth aspects, a plurality of short-circuit electrodes are provided. Disconnection can be more reliably prevented.

According to the tenth aspect, the first aspect is provided.
In the discharge lamp according to any one of the first to ninth aspects, since the lead wire for supplying current to the external electrode is connected to the short-circuit electrode, it is possible to prevent the entire lamp current from flowing only to the external electrode at the connection portion with the lead wire. In addition, disconnection of the external electrode due to overcurrent can be prevented.

According to the eleventh aspect, according to the first aspect,
11. In the discharge lamp according to any one of Items 10 to 10, since the tubular outer tube formed of a light transmissive material and covering the airtight container is provided, the external electrode wound around the outer periphery of the airtight container is contaminated. Can be prevented from adhering,
In addition, it is possible to prevent metal ions emitted from the external electrode from adhering to surrounding members.

According to the ultraviolet irradiation apparatus of the twelfth aspect, the plurality of discharge lamps of the eleventh aspect and a holding housing for holding the discharge lamps close to each other so that their central axes are parallel to each other are provided. Claim 1
The discharge lamp according to any one of claims 10 to 10 can be irradiated with ultraviolet rays by appropriately selecting a discharge medium, and has the same operation and effect as the case where the outer tube according to claim 10 is provided for the discharge lamp. Play. Further, since the discharge lamp directly faces the object to be irradiated with the ultraviolet light, the irradiation of the object with the ultraviolet light can be efficiently performed. Irradiation of ultraviolet rays can be efficiently performed even on an irradiation target that has not been irradiated.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing a dielectric barrier discharge lamp according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional side view thereof.

3A is an enlarged front view showing an end of the airtight container, and FIG. 3B is a plan view thereof.

FIG. 4 is a vertical sectional side view showing a dielectric barrier discharge lamp according to a second embodiment of the present invention.

FIG. 5 is a vertical sectional front view showing a dielectric barrier discharge lamp according to a third embodiment of the present invention.

FIG. 6 is a vertical sectional side view thereof.

FIG. 7 is a longitudinal sectional front view showing a part of the enlarged view.

FIG. 8 is a sectional view showing an ultraviolet irradiation device according to a fourth embodiment of the present invention.

FIG. 9 is a vertical sectional front view showing a conventional dielectric barrier discharge lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a, 1b Discharge lamp 2 Airtight container 2b Sealing part 3 Internal electrode 5 External electrode 6 Short circuit electrode 7 Outer tube 9 Constriction part 10 Rough surface part 11 Tip part 17 Lead wire 18 Internal electrode 18a Internal power supply electrode 18b Conductive anchor 21 UV irradiation device 22 Holding case

Claims (12)

[Claims] 1. An elongated tubular hermetic container mainly formed of a dielectric material; an internal electrode disposed in the hermetic container along a longitudinal direction thereof; and a coiled shape along the longitudinal direction of the hermetic container. A linear external electrode wound around the container; a short-circuit electrode disposed along the longitudinal direction of the hermetic container and cross-contacting the external electrode; and a discharge medium sealed in the hermetic container. A discharge lamp. 2. The discharge lamp according to claim 1, wherein the short-circuit electrode has lower electric resistance than the external electrode. 3. When the tube diameter of the airtight container is D mm, the wire diameter of the external electrode is d1 mm, and the winding pitch of the external electrode around the tubular portion of the airtight container is hmm, 0.05 ≦ d1. 3. The discharge lamp according to claim 1, wherein the relationship is defined as: ≦ 0.9, 6 ≦ D ≦ 40, and 10 <h / d1 <100. 4. The discharge lamp according to claim 1, wherein constricted portions are formed at both ends of the hermetic container, and the external electrode is wound around the constricted portion a plurality of times. . 5. A pinch-sealed sealing portion is formed at both ends of the hermetic container, and at both ends of the hermetic container, at an inclined surface inside the sealing portion and facing the sealing portion. The discharge lamp according to any one of claims 1 to 4, wherein a rough surface portion is formed. 6. The internal electrode is disposed on a substantially central axis in the hermetic container and extends in the central axis direction, and is formed in a ring shape along the inner peripheral surface of the hermetic container. And a plurality of conductive anchors arranged at substantially equal intervals along the central axis direction of the hermetic container and connected to the internal power supply electrode.
6. The discharge lamp according to any one of claims 5 to 5. 7. The method according to claim 6, wherein when the wire diameter of the external electrode is d1 mm and the pitch of the conductive anchor is Hmm, 100 <H / d1 <300. Discharge lamp. 8. The discharge lamp according to claim 1, wherein the short-circuit electrode is arranged near a chip portion present on an outer peripheral portion of the hermetic container. 9. The discharge lamp according to claim 1, wherein a plurality of said short-circuit electrodes are provided. 10. The short-circuit electrode according to claim 1, wherein a lead wire for energizing the external electrode is connected to the short-circuit electrode.
10. The discharge lamp according to any one of claims 9 to 9. 11. The discharge lamp according to claim 1, further comprising a tubular outer tube formed of a light transmissive material and covering the airtight container. 12. A plurality of discharge lamps according to claim 11, and a holding case for holding the plurality of discharge lamps close to each other so that their central axes are parallel to each other. An ultraviolet irradiation device characterized by the above-mentioned.