JP2003317670A - Dielectric barrier discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric barrier discharge lamp which prevents a local degradation of a discharge lamp by not making an inner electrode discharge at the same point and at the same time, has no points where discharge is hard nor has an unstable discharge. <P>SOLUTION: The dielectric barrier discharge lamp 1 is provided with a discharge vessel 2, in which, an inner electrode 3 is fitted. The inner electrode 3 is provided with a coarse-wound coil part 3A and a thick-wound coil part 3B. An outer electrode 7 is deposited on an outer periphery of the discharge vessel 2. The outer electrode is fitted only at a position corresponding to the coarse-wound coil part 3A on the periphery of the inner electrode 3, and not at a position corresponding to the thick-wound coil part 3B. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a dielectric barrier discharge lamp that forms excimer molecules by dielectric barrier discharge and emits light emitted from the excimer molecules.

[0002]

2. Description of the Related Art Heretofore, as a dielectric barrier discharge lamp for causing a discharge between an internal electrode and an external electrode through a dielectric, for example, Japanese Patent No. 3178237 (JP-A-7-27).
2692). This dielectric barrier discharge lamp has a tubular discharge vessel having an elongated shape as a whole. A light-transmitting outer electrode is provided on the outer surface of the discharge vessel, and an inner electrode made of an elongated metal circular tube is provided on the inner side of the discharge vessel. The discharge vessel is filled with a discharge gas that forms excimer molecules by dielectric barrier discharge while being in contact with the inner electrode. In this dielectric barrier discharge lamp, the fluctuation of the light output is small and the diameter of the lamp can be reduced.

However, in the dielectric barrier discharge lamp disclosed in Japanese Patent No. 3178237, due to the difference in the expansion coefficient between the discharge container and the internal electrode, the discharge container may be changed when the ambient temperature changes or the temperature rises during discharge. There was a problem that the battery was damaged or the internal electrodes were bent and uniform discharge was difficult to occur.

To solve this problem, Japanese Unexamined Patent Publication No. 9-28309
There is a fluorescent lamp disclosed in Japanese Patent Laid-Open No. In this fluorescent lamp, at least a part of an internal electrode provided in a tubular glass bulb (discharge vessel) is formed in a coil shape, and is erected in the tubular glass bulb with an appropriate tension. As the internal electrode, there are one in which the whole is formed in a coil shape, and one in which both ends are in a coil shape and a linear shape is formed between them.

[0005]

However, the above-mentioned Japanese Unexamined Patent Application Publication No.
Among the fluorescent lamps disclosed in Japanese Patent Publication No. 283091,
In the case where the entire inner electrode has a coil shape, the coil is wound in a dense state so that tension can be applied to the entire inner electrode. For this reason, the point of strong discharge in the internal electrodes is likely to be at the same place such as the end of the coil. As described above, if strong discharge occurs at the same place, there is a problem that the discharge container is locally deteriorated and the entire fluorescent lamp becomes unusable.

Further, in the case where both ends of the internal electrode are coil-shaped and the space between them is linear, the discharge is concentrated on the edge portion of the coil-shaped internal electrode, the center of the coil is difficult to discharge, and the discharge at that position is not generated. There was a problem of becoming unstable.

Therefore, an object of the present invention is to prevent local deterioration of the discharge container by preventing the strong discharge from occurring at the internal electrodes at the same time. It is to provide a dielectric barrier discharge lamp that does not become unstable.

[0008]

In the dielectric barrier discharge lamp according to the present invention, which has solved the above-mentioned problems, an internal electrode is provided in a discharge vessel, the internal electrode is fixed to the discharge vessel, and the internal electrode is fixed through the discharge vessel. A dielectric barrier discharge lamp in which an external electrode is provided around the internal electrode is characterized in that the internal electrode has a close-wound coil portion and a coarse-wound coil portion.

In the present invention, the internal electrode has a coarse winding coil portion in addition to the close winding coil portion. By having such a roughly wound coil portion, the strong discharge portion on the internal electrode is constantly moved, and it is possible to prevent the internal surface of the discharge vessel from being locally deteriorated by the discharge plasma.

Here, the "densely wound coil" and "coarsely wound coil" referred to in the present invention mean the relative relationship between them,
"Densely wound coil" means a coil wound so as to be denser than "coarsely wound coil", and "coarsely wound coil" means
It means a coil that is wound loosely rather than a tightly wound coil.

Further, it is preferable that the outer electrode is provided around only the roughly wound coil portion of the inner electrode.

In the dielectric barrier discharge lamp according to the present invention, the internal electrode has a coarse winding coil portion and a close winding coil portion, and the external electrode provided around the internal electrode is
It is provided only in the position corresponding to the coarse winding coil portion of the internal electrode. Therefore, since the distance between the external electrode and the internal electrode can be kept constant, uniform and stable discharge can be performed without lowering the emission intensity.

Further, the close-wound coil portion may be provided on one end side of the coarse-wound coil portion in the internal electrode, and the close-wound coil portion is formed on the other end side of the coarse-wound coil portion. It can also be an aspect. Further, the coarsely wound coil portion may be formed by being divided into a plurality of parts, and the densely wound coil portion may be formed between the plurality of roughly wound coil portions.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will now be described in detail with reference to the drawings. The same elements will be denoted by the same reference symbols, without redundant description.

FIG. 1 is a side view of a dielectric barrier discharge lamp according to a first embodiment of the present invention, FIG. 2 is an end side enlarged view of the dielectric barrier discharge lamp shown in FIG. 1, and FIG. FIG. 3 is an enlarged plan view of an end portion of the dielectric barrier discharge lamp shown in FIG.

As shown in FIG. 1, a dielectric barrier discharge lamp (excimer discharge lamp) 1 according to this embodiment is an elongated tubular light-transmissive discharge vessel (hereinafter referred to as "discharge vessel").
Equipped with 2. The discharge vessel 2 has an outer diameter of 10 mm and an inner diameter of 8
The glass bulb is made of a cylindrical glass material having a thickness of 1 mm (mm) and a length of 360 mm. Inside the discharge vessel 2,
An internal electrode 3 made of a long material is provided. here,
The long material is a so-called elongated member whose length in the direction orthogonal to the length in the longitudinal direction is short, and includes, for example, a wire rod, a rod material, a pipe material, or an elongated plate material. It doesn't matter.

The internal electrode 3 is a solid metal wire made of, for example, tungsten and is provided so as to penetrate in the longitudinal direction of the discharge vessel 2. The internal electrode 3 includes a coarse winding coil portion 3A as shown in FIG.
The close-wound coil portion 3B is formed on one end side of A, and the linear end portion 3C is formed on the outer side of the close-wound coil portion 3B.

Further, as shown in FIG. 1, a linear end portion 3D is formed on the other end side of the coarsely wound coil portion 3A.
The coarse winding coil portion 3A, the close winding coil portion 3B, the linear end portion 3C, and the linear end portion 3D have an outer diameter of 0.1.
It is formed by deforming one metal wire of 8 mm. In addition, these coarsely wound coil portions 3A,
The close-wound coil portion 3B and the linear end portion 3C are all arranged coaxially, and the axis thereof coincides with the extension line of the linear end portion 3D. The coarse winding coil portion 3A and the close winding coil portion 3B have the same winding diameter of 0.8 mm, and the coarse winding coil portion 3A has a pitch (distance between windings) of 2 mm.
Therefore, the roughly wound coil portion 3A has almost no tension in the axial direction. The pitch of the tightly wound coil portions 3B is about 0.25 mm. In addition, the roughly wound coil portion 3A
Is preferably 1.0 to 3.0 mm, and the pitch of the tightly wound coil portion 3B is preferably 0.2 to 0.5.

Metal foils 4 and 4 made of molybdenum foil containing molybdenum are connected to the linear ends 3C and 3D of the internal electrode 3, respectively. The metal foil 4 is a plate-shaped body having a horizontally long rectangular surface, and as shown in FIG. 3, the linear end 3C or the linear end of the internal electrode 3 is formed at the center portion in the height direction on the surface at one end side thereof. The parts 3D are connected by welding, for example.

Both ends of the discharge vessel 2 in the longitudinal direction are pinch-sealed to form pinch-sealed portions 5 and 5, respectively.
And the inside of the discharge vessel 2 is sealed. The metal foil 4 is disposed inside the pinch seal portions 5 and 5, and the metal foil 4 is attached to the internal electrode 3 by the pinch seal portions 5 and 5.
Is connected to the straight end 3C or the straight end 3D. Further, lead wires 6 and 6 made of, for example, molybdenum wires are connected to the central portions in the height direction on the surfaces of the other ends of the metal foils 4 and 4 by welding, for example. These lead wires 6 and 6 are respectively welded to the same surface as the surface to which the linear end portion 3C or the linear end portion 3D of the internal electrode 3 is connected.

An external electrode 7 is provided on the outer peripheral portion of the discharge vessel 2. As shown in FIG. 4, the external electrode 7 is provided at the upper part in the circumferential direction of the discharge vessel 2 so as to cover the range of 240 degrees around the exhaust pipe 8, and the lower part 120 in the circumferential direction. The degree is open. This opened portion becomes a light irradiation portion. The external electrode 7 is made of a metal film such as aluminum. The metal film is formed by vapor-depositing aluminum to a thickness of 150 nm on the upper portion of the discharge vessel 2, and has a function as a reflecting mirror.
Therefore, the light generated by the discharge is reflected by the reflecting mirror and is irradiated only from the light irradiation portion, and thus the light utilization efficiency can be increased accordingly. The outer diameter of the internal electrode 3 is
Since it is about 1/42 of the inner diameter of the discharge vessel 2, which is sufficiently small,
The light blocked by the internal electrodes 3 can be reduced very much,
The utilization efficiency can be increased accordingly.

Further, the dielectric barrier discharge lamp 1 is shown in FIG.
Both ends are gripped by the external electrode fittings 9, 9 shown in (a) and (b), and attached to a casing (not shown). These external electrode fittings 9 and 9 are attached in a state of contacting both ends of the external electrode 7, respectively, and current is supplied to the external electrode 7 from the external electrode fittings 9 and 9.

Explaining the relative positional relationship between the external electrode 7 and the internal electrode 3, the external electrode 7 is provided around the internal electrode 3. The external electrode 7 is provided only in the position corresponding to the coarse winding coil portion 3A of the internal electrode 3, and the external electrode 7 is not provided in the position corresponding to the close winding coil portion 3B.

Further, an exhaust pipe 8 is provided in the vicinity of the end of the discharge vessel 2 where the close-wound coil portion 3B is provided. The air in the discharge vessel 2 is discharged through the exhaust pipe 8 to make the inside of the discharge vessel 2 in a vacuum state, and then the discharge vessel 2 is filled with an excimer discharge gas such as xenon. In this way, the discharge vessel 2 is filled with the excimer discharge gas, and the internal electrodes 3 are exposed to the excimer discharge gas.

On the other hand, after the dielectric barrier discharge lamp 1 is attached to a casing (not shown), the lead wires 6 and 6 and the external electrode fittings 9 and 9 are connected to a lighting power source (not shown) through wirings. It This lighting power supply generates an AC voltage by applying a DC voltage with an inverter, and applies an AC voltage of, for example, 0.5 to 2 kV and a frequency of 35 to 50 kHz to the dielectric barrier discharge lamp 1. To do.

When arranging the dielectric barrier discharge lamp 1 in the housing, an external electrode located on the opposite side of the light irradiating portion for adhering a radiator (not shown) to the external electrode 7 of the dielectric barrier discharge lamp 1 is provided. The heat of the dielectric barrier discharge lamp 1 can be favorably absorbed by mounting the dielectric barrier discharge lamp 1 on the housing with the external electrode fittings 9 and 9 in a direction in which 7 contacts the radiator. Further, by appropriately cooling the radiator with water or air, the dielectric barrier discharge lamp 1 can be suitably cooled. Further, when a plurality of dielectric barrier discharge lamps 1 are arranged side by side to form the irradiation device, the distance between the dielectric barrier discharge lamps 1 and 1 is set to 13 mm, so that the range within several mm from the irradiation device. Thus, a uniform and sufficient irradiation intensity can be obtained.

In the dielectric barrier discharge lamp 1 having the above structure, the internal electrode 3 is provided with the coarse winding coil portion 3A and the close winding coil portion 3B. Therefore, the tightly wound coil portion 3B can apply tension to the coarsely wound coil portion 3A. Therefore, the influence of the expansion due to the linear expansion of the roughly wound coil portion 3A can be mitigated, so that the distance between the roughly wound coil portion 3A and the inner surface of the discharge vessel 2 can be kept constant.

Generally, in the dielectric barrier discharge lamp, the glass tube exists as a dielectric in the discharge path, and it is possible to prevent the discharge from concentrating at one place even if the discharge area is large. This is a discharge type in which a point light source is not suitable for a lamp and a wide discharge part can be provided. However, in the conventional dielectric barrier discharge lamp, the strong discharge point existing in the internal electrode 3 is likely to be always in the same place, and the internal surface of the discharge vessel 2 is likely to be locally deteriorated. In this regard, in the dielectric barrier discharge lamp 1 according to the present embodiment, since the internal electrode 3 has a gently coiled portion such as the coarsely wound coil portion 3A, a strong discharge point on the internal electrode 3 is generated. It will always move.
Therefore, it is possible to prevent the inner surface of the discharge vessel 2 from being locally deteriorated by the discharge plasma.

Further, in the dielectric barrier discharge lamp 1, the external electrode 7 is provided around the internal electrode 3, but the external electrode 7 is provided only in the position corresponding to the coarsely wound coil portion 3A in the internal electrode 3. , Is not provided at a position corresponding to the close-wound coil portion 3B. Therefore, the discharge state can be easily stabilized, and the emission intensity can be prevented from lowering. Furthermore, the tightly wound coil section 3
Since the external electrode 7 is not provided at the position corresponding to B, the portion where the discharge is likely to be concentrated such as the edge portion of the close-wound coil portion 3B and the portion where the discharge is difficult to discharge such as the central portion of the close-wound coil portion 3B can do.

Next, a second embodiment of the present invention will be described. FIG. 6 is a side view of the dielectric barrier discharge lamp according to this embodiment. As shown in FIG. 6, the dielectric barrier discharge lamp 10 according to the present embodiment is different from the dielectric barrier discharge lamp 1 according to the first embodiment mainly in the configuration of the coil portion of the internal electrode. . Explaining this difference, the internal electrode 13 is composed of the coarsely wound coil portion 1.
3A, one end of which is closely wound coil portion 13B
And the coarsely wound coil end 13C is connected to the close-wound coil portion 13B. The coarsely wound coil-shaped end portion 13D is also connected to the other end of the coarsely wound coil portion 13A. Then, these coarsely coiled end portions 13C and 13D are connected to the metal foils 4 and 4, respectively.

The coarsely wound coil portion 13A is rotated only once between the densely wound coil portion 13B connected to one end thereof and the coarsely wound coil portion 13D connected to the other end thereof, so to speak, in one turn. Has been formed. The outer diameter of the coarse winding coil portion 13A is set to be larger than the outer diameter of the close winding coil portion 13B. Further, the external electrode 7 is provided by being vapor-deposited on the discharge container 2, and is provided only in a position corresponding to the coarsely wound coil portion 13A on the periphery of the internal electrode 13. Others have the same configuration as that of the first embodiment.

Also in this embodiment, the outer electrode 7 is provided only in the portion corresponding to the coarsely wound coil portion 13A in the periphery of the inner electrode 13, and the outer electrode 7 is provided in the portion corresponding to the closely wound coil portion 13B. It will not be provided. Therefore, it is possible to apply an appropriate tension to the roughly wound coil portion 13A, stabilize the discharge state, and prevent the emission intensity from decreasing.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in each of the above-described embodiments, the outer electrode is provided only on the portion corresponding to the coarsely wound coil portion in the outer peripheral portion of the inner electrode, but the external electrode is provided on the portion corresponding to the entire inner electrode. can do. Further, in each of the above embodiments, the close-wound coil portion is provided only on one end side of the coarse-wound coil portion, but the close-wound coil portion may be provided at both ends of the coarse-wound coil portion. In particular, by applying the same tension to the coarsely wound coil portion by these double tightly wound coil portions, it is possible to uniformly and stably apply tension to the coarsely wound coil portion. Further, in each of the above embodiments, the internal electrode is formed by the coarse winding coil portion and the close winding coil portion,
The internal electrode may have a mode other than these, for example, a linear part.

In each of the above embodiments, the winding diameter of the coarse winding coil is the same as the winding diameter of the close winding coil, but the winding diameter of the coarse winding coil is smaller than that of the close winding coil. It can be increased, and vice versa.

On the other hand, in each of the above-described embodiments, the coarse winding coil portion and the close winding coil portion are formed by performing deformation processing such as bending one long material, but the coarse winding coil portion and the close winding coil portion are formed. The parts may be formed of different members and may be connected to each other. Furthermore, in each of the above-described embodiments, a discharge vessel having a metal film deposited thereon is used as the external electrode. However, for example, an external electrode having a mesh structure in which a metal wire is stretched around the discharge vessel in a mesh shape is used. You can also

[0036]

As described above, according to the present invention,
Preventing local deterioration of the discharge vessel by preventing the same strong discharge points from occurring at the internal electrodes, there is no position where it is difficult to discharge, and a dielectric barrier that does not cause unstable discharge. A discharge lamp can be provided.

[Brief description of drawings]

FIG. 1 is a side view of a dielectric barrier discharge lamp according to a first embodiment of the present invention.

2 is an end side enlarged side view of the dielectric barrier discharge lamp shown in FIG. 1. FIG.

FIG. 3 is an enlarged plan view of an end portion of the dielectric barrier discharge lamp shown in FIG.

4 is a sectional view taken along line IV-IV in FIG.

5A and 5B are diagrams showing external electrode fittings, in which FIG. 5A is a side view and FIG. 5B is a front view.

FIG. 6 is a side view of a dielectric barrier discharge lamp according to a second embodiment of the present invention.

[Explanation of symbols]

1, 10 ... Dielectric barrier discharge lamp, 2 ... Discharge container,
3, 13 ... Internal electrodes, 3A, 13A ... Coarse winding coil portion,
3B, 13B ... Densely wound coil portion, 3C, 3D ... Straight end portion, 13C, 13D ... Coarsely wound coil end portion, 4 ... Metal foil, 5 ... Pinch seal portion, 6 ... Lead wire, 7 ... External electrode, 8 ... Exhaust pipe 9 ... External electrode fitting.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sumi Fujita             1 Hamamatsuho, 1126 Nomachi, Hamamatsu City, Shizuoka Prefecture             Tonics Co., Ltd. (72) Inventor Hidetsugu Takaoka             1 Hamamatsuho, 1126 Nomachi, Hamamatsu City, Shizuoka Prefecture             Tonics Co., Ltd.

Claims (4)

[Claims] 1. A dielectric barrier discharge lamp in which an internal electrode is provided in a discharge vessel, the internal electrode is fixed to the discharge vessel, and an external electrode is provided around the internal electrode through the discharge vessel. The dielectric barrier discharge lamp, wherein the internal electrode has a closely wound coil portion and a coarsely wound coil portion. 2. The dielectric barrier discharge lamp according to claim 1, wherein the outer electrode is provided around only the roughly wound coil portion of the inner electrode. 3. The dielectric barrier discharge lamp according to claim 1, wherein a close-wound coil portion is provided on one end side of the coarse-wound coil portion in the internal electrode. 4. The dielectric barrier discharge lamp according to claim 3, wherein a densely wound coil portion is formed on the other end side of the coarsely wound coil portion.