JPH06338301A - Dielectric barrier discharge lamp and processing method using same - Google Patents

Abstract

PURPOSE:To obtain a lamp having a high radiance by providing a condenser lens near a light deriving window member. CONSTITUTION:Flat dielectrics 2, 3 and a side plate 6 are provided, and a light deriving window member 1 is provided in parallel with a discharge passage, and a condensing cylindrical lens 10 is provided near the member 1. This discharge container is filled with the discharge gas for forming excimer molecule with the dielectric barrier discharge, and voltage is applied to electrodes 4, 5 by an alternating current power source 22. Microplasmas 20a-20d are thereby generated stably to generate excimer molecules, and the excimer light is radiated. The light radiated from the plasma 20a-20d passes the member 1, and is collected by the condenser lens 10. Consequently, the radiated light having a high radiance can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is, for example, a kind of discharge lamp used as an ultraviolet light source for photochemical reaction, which forms excimer molecules by dielectric barrier discharge and utilizes the light emitted from the excimer molecules. To a so-called dielectric barrier discharge lamp and a processing method using the dielectric barrier discharge lamp.

[0002]

2. Description of the Related Art As a technique related to the present invention, there is, for example, Japanese Patent Laid-Open Publication No. 2-7353, in which a discharge vessel is filled with a discharge gas for forming excimer molecules, and a dielectric is used. Barrier discharge (also known as ozonizer discharge or silent discharge. See the revised edition “Discharge Handbook” published by The Institute of Electrical Engineers of Japan, June 2001, Reprint 7th edition, page 263) forms excimer molecules, and the light emitted from the excimer molecules is extracted. A radiator, or dielectric barrier discharge lamp, is described. Further, US Pat. No. 2,943,225 describes a dielectric barrier discharge lamp device having a light extraction window member provided in parallel with the discharge path of the dielectric barrier discharge. The dielectric barrier discharge lamp as described above is useful because it has various features that conventional low-pressure mercury lamps and high-pressure arc discharge lamps do not have. In particular, the dielectric barrier discharge lamp provided with the light extraction window member in parallel with the discharge path can increase the radiance by increasing the size of the discharge space in the direction perpendicular to the light extraction window member. I also have. However, even the above dielectric barrier discharge lamp has a problem that the radiance is not always sufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a dielectric barrier discharge lamp with high radiance, and further to provide a treatment method using the dielectric barrier discharge lamp. .

[0004]

DISCLOSURE OF THE INVENTION It is an object of the present invention to fill a discharge vessel with a discharge gas that forms excimer molecules by a dielectric barrier discharge, and a part of the discharge vessel is a dielectric barrier discharge dielectric. In a dielectric barrier discharge lamp that also serves as a body and has a light extraction window member provided in parallel with the discharge path of the dielectric barrier discharge, by providing a condenser lens in the immediate vicinity of the light extraction window member. Can be achieved. Alternatively, the object of the present invention can be further achieved by configuring a part of the condenser lens so as to also serve as the light extraction window member. Further, the object of the present invention can be further achieved by providing a light reflecting film on the tube wall of the discharge vessel which is in the vicinity of the light extraction window member and is parallel to the discharge path. Further, the object of the present invention can be further achieved by configuring the length H parallel to the discharge path of the light extraction window member to exceed the discharge path length L of the dielectric barrier discharge.

[0005]

[Function] Dielectric barrier discharge is described in the "Discharge Handbook"
As described in (1), it is a large collection of minute discharge plasmas (hereinafter referred to as microplasma) having a very small plasma diameter and a very short discharge duration. We have proposed a dielectric barrier discharge lamp in which at least the discharge container is filled with a discharge gas that forms excimer molecules by dielectric barrier discharge, and a part of the discharge container also serves as a dielectric of the dielectric barrier discharge. Since the microplasma is very thin and the absorption of the excimer light in the discharge space is small, the excimer light generated in the discharge space can proceed without being absorbed in the long discharge space. By providing a light extraction window member in parallel with the discharge path of the body barrier discharge, and by further providing a condenser lens in the immediate vicinity of the light extraction window member, excimer light in an optically deep range is efficiently condensed. We have experimentally discovered that high radiance can be obtained. In addition, the above-mentioned high brightness by the condenser lens, excimer molecules are generated by dielectric barrier discharge,
Only possible in a dielectric barrier discharge lamp that utilizes excimer light, which utilizes a uniform discharge plasma and in the case of a conventional glow discharge lamp that utilizes the spectral lines of the atoms, such as a low pressure mercury lamp, of the emitted light. Due to the absorption, the effect of increasing the brightness by the condenser lens is extremely small.

The operation will be described below with reference to FIG. 1 which is a side sectional view showing an outline of the present invention, FIG. 2 which is a front view and FIG. 3 which is a partial side sectional view. That is, for discharge for forming excimer molecules by a dielectric barrier discharge in a discharge vessel composed of flat plate-shaped dielectrics 2, 3, side plates 6, 8a, 8b and a light extraction window member 1 provided in parallel with a discharge path. When gas is filled and a voltage is applied to the electrodes 4 and 5 by the AC power source 22, the microplasma 20a, 20b, 20
c and 20d are stably generated, excimer molecules are generated,
Excimer light is emitted. Since the microplasma is very thin and the absorption of the excimer light in the discharge space is small, the excimer light can travel without being absorbed over a long distance in the discharge space, and therefore, the excimer light is parallel to the discharge path. By providing the cylindrical lens 10 for condensing,
Microplasma 21 relatively close to the light extraction window member 1
It is possible to collect not only the radiated light from a but also the radiated light from the microplasma 21d located away from the light extraction window member 1, and thus a high-intensity dielectric barrier discharge lamp can be obtained. Furthermore, if the light extraction window member 1 is removed, the cylindrical lens 10 for condensing is attached, and the light extraction window member and the condensing lens are also used, the light extraction window member 1 does not absorb the light, so that higher brightness can be obtained. To be

Since the excimer light has a small absorption in the discharge space, the excimer light generated in the discharge space easily reaches the side plates 8a and 8b, and therefore the side plates 8a and 8b.
The light is absorbed by or is leaked to the outside to cause a loss, which lowers the luminous efficiency. As a result, when the dielectric barrier discharge lamp is long along the light extraction window member, the light emitted from the portions of the light extraction window member 1 in the vicinity of the side plates 8a and 8b is considerably larger than the light emitted from the central portion. Get smaller. That is, the spatial distribution of the light emitted from the light extraction window member 1 in the direction perpendicular to the discharge path becomes non-uniform. In addition,
The side plate 6 influences the luminous efficiency, but hardly influences the spatial distribution of the emitted light. When a light reflecting film is provided on the tube wall of the discharge vessel which is in the immediate vicinity of the light extraction window member and is parallel to the discharge path, and a condenser lens is provided in the immediate vicinity of the light extraction window member, light on the tube wall is provided. Loss is reduced and the radiance is reduced less in the portions of the light extraction window member 1 near the side plates 8a and 8b. As a result, the spatial uniformity of the radiance is good and the light extraction efficiency is high. That is, a dielectric barrier discharge lamp having a sufficient luminous efficiency can be obtained.

As shown in FIG. 1, when a voltage is applied to the electrodes 4 and 5 by the AC power source 22, in addition to the microplasmas 20a, 20b, 20c and 20d which are stably generated,
A creeping discharge plasma 7 is formed along the surface of the light extraction window member 1.
Occurs irregularly. Therefore, the light output becomes unstable. Further, for the radiance obtained from the light extraction window member 1, the microplasma 20a, 20b, 20
In addition to the positive columns of c and 20d, the surface discharge plasmas 21a, 21b, 21c, which are generated on the surfaces of the dielectrics 2 and 3,
The emitted light from 21d greatly contributes, and therefore, when the length of the light extraction window member parallel to the discharge path is shorter than the discharge path length of the dielectric barrier discharge, the luminous efficiency is extremely reduced. There was found. In particular, when a condenser lens is provided in the immediate vicinity of the light extraction window member 1 to collect light, the length parallel to the discharge path of the light extraction window member is smaller than the discharge path length of the dielectric barrier discharge. As a result, the decrease in luminous efficiency is greater.

As shown in FIG. 3, in a dielectric barrier discharge lamp having a light extraction window member 1 provided in parallel with the discharge path of the dielectric barrier discharge, the discharge path of the light extraction window member 1 is If the parallel length H exceeds the discharge path length L of the dielectric barrier discharge, the recess 23 is formed, and as a result, the discharge path length of the creeping discharge becomes long and the tube forming the recess 23 is formed. It is difficult to irradiate the wall with radiation from the dielectric barrier discharge lamp.
Is less likely to occur, and as a result, an optical output with good temporal stability can be obtained. Further, the length H parallel to the discharge path of the light extraction window member 1 is configured to exceed the discharge path length L of the dielectric barrier discharge, so that the creeping surface generated on the surfaces of the dielectrics 2 and 3 is formed. Discharge plasma 21
Light emitted from a, 21b, 21c, and 21d efficiently enters the condenser lens, so that high brightness and high efficiency can be obtained.
When the value obtained by dividing H by L is 1.2 or more, the effects of stabilizing light emission, improving brightness, and improving efficiency are further exhibited.

When the dielectric barrier discharge lamp of the present invention is used, the dielectric barrier discharge lamp of the present invention can form a linearly illuminated surface of high brightness, so that a linear object to be treated can be treated as a linear object. By arranging them so as to match the irradiation surface, it is possible to process the linear objects at high speed and with high efficiency. The processing mentioned here includes cleaning using light, etching, surface modification, curing of paint, disinfection and sterilization.

When processing is carried out using light, it is desirable to bring the object to be processed and the light source as close as possible in view of the efficiency of light utilization. When treating the surface of a flat object to be treated, if a light source with a large light emitting surface such as a flat light emitting surface is used, the distance between the surface of the object to be treated and the light source is spread over the entire light emitting surface of the light source. It is generally difficult to keep constant, that is, it is generally difficult to keep the distance between planes constant, so that the irradiation dose on the surface of the object to be treated becomes non-uniform, and uniform treatment is performed. Is impossible. Since the light extraction window member or the condenser lens of the dielectric barrier discharge lamp of the present invention has a narrow band shape and can form a high-luminance linear irradiation surface, the dielectric barrier discharge lamp of the present invention can be formed. When using, the distance between the plane and the straight line may be kept constant, and the linear portion on the surface of the object to be processed can be uniformly irradiated. By using the dielectric barrier discharge lamp of the present invention and moving the flat object to be processed or the dielectric barrier discharge lamp relatively in the width direction of the window member, the surface of the flat object to be processed is changed. Can be processed uniformly. The use of the dielectric barrier discharge lamp of the present invention becomes more advantageous especially when the object to be treated is a film and it is difficult to maintain a flat surface over a large area.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A schematic view of a flat plate type dielectric barrier discharge lamp which is a first embodiment of the present invention is shown in a side sectional view of FIG. 1 and a front view of FIG. Two rectangular synthetic quartz glass plates having a long side of 300 mm and a short side of 80 mm are used as dielectrics 2 and 3, and the distance between the inner surfaces of the dielectrics 2 and 3 is set to 8 mm, and they are opposed to each other.
The light extraction window member 1 and the side plates 8a, 8b, 6 were provided in the peripheral portion to form a discharge vessel. The light extraction window member 1 is provided on one long side of the dielectrics 2 and 3 and has a length H parallel to the discharge path as a discharge path length L of the dielectric barrier discharge, that is, the dielectrics 2 and 3. 8m, which is the same as the distance between inner surfaces of 8mm
m. Light reflecting films 9a, 9b, 9c made of aluminum were provided on the outside of the side plates 8a, 8b and 6 by vapor deposition. The light-collecting cylindrical lens 10 was placed in the immediate vicinity of the window member 1 using a silicone resin adhesive. The adhesion was performed only at the end of the light extraction window member. As a discharge gas, xenon was filled in the discharge space 11 at 300 Torr, and a voltage was applied to the electrodes 4 and 5 made of aluminum which also served as a light reflection plate by the power source 22. As a result, a dielectric barrier discharge was generated and xenon excimer molecules were discharged. The emitted 172 nm and ultraviolet rays in the vicinity thereof were condensed by the condensing cylindrical lens 10, and a high-intensity dielectric barrier discharge lamp having a linear light emitting surface was obtained.
Further, by providing the side plates 8a and 8b with the reflection films 9a and 9b, a dielectric barrier discharge lamp having improved spatial uniformity of light output and improved luminous efficiency was obtained.

In the second embodiment of the present invention, in the flat plate dielectric barrier discharge lamp of the first embodiment, the length H parallel to the discharge path of the light extraction window member 1 is defined as the dielectric barrier discharge. 10 mm, which is larger than the discharge path length L of 8 mm. In this embodiment, in addition to the spatial uniformity of the light output, stabilization of the light output can be achieved by suppressing the creeping discharge in the vicinity of the window member, and the result that the light extraction efficiency is improved, Higher brightness was achieved.

In the third embodiment of the present invention, in the flat plate dielectric barrier discharge lamp of the first embodiment, the light extraction window member 1 is removed and, instead, a converging cylindrical lens 10 made of synthetic quartz glass is used. Is attached to the discharge vessel by welding, and the light extraction window member and the condenser lens are also used. With the above configuration, it was possible to obtain a smaller-sized dielectric barrier discharge lamp with higher brightness.

A front view of an arc-shaped dielectric barrier discharge lamp according to the fourth embodiment of the present invention is shown in FIG. Outer diameter 70mm
And a dielectric material 41, 42 in which a quartz glass tube having an outer diameter of 40 mm is vertically divided, a light extraction window member 43, a side plate 44a,
44b and a side plate 6 (not shown) were provided to form a discharge vessel. Although not shown, the light extraction window member 4
An arcuate columnar condensing lens is provided along the nearest direction. Also, on the inner surfaces of the side plates 44a and 44b,
25 layers of MgF ₂ and LaF ₃ are alternately laminated to form 172 nm
Are provided with multilayer dielectric reflection films 45a and 45b. Further, although not shown, similar multilayer dielectric reflection films are provided on the inner surfaces of the dielectrics 41 and 42. When 400 torr of xenon is sealed in the discharge space 11 as a discharge gas and an AC voltage is applied to the electrodes 4 and 5 provided on the outer surfaces of the dielectrics 41 and 42, a stable dielectric barrier discharge is generated and the excimer of xenon is generated. The 172 nm ultraviolet light emitted from the molecule and ultraviolet rays in the vicinity thereof are condensed by an arc-shaped cylindrical condenser lens, and have high brightness, good spatial uniformity, and highly efficient arc-shaped linear light emission. A dielectric barrier discharge lamp having a face was obtained. Side plates 44a, 4
By using the light reflection films 45a and 45b provided on the side plate 4b as electrical insulators, there is an advantage that creeping discharge is less likely to occur on the side plate.

The fifth embodiment of the present invention is a cleaning method using the dielectric barrier discharge lamp of the present invention, and a schematic view is shown in FIG. Condensing lens 1 of the same dielectric barrier discharge lamp 51 as the flat dielectric barrier discharge lamp shown in the second embodiment.
In parallel with 0, the optical fiber 50 as the object to be cleaned is installed in an atmosphere containing oxygen. 52 is a light reflection plate. The condenser lens 10 of the dielectric barrier discharge lamp 51 concentrates and irradiates the surface of the optical fiber 50 with ultraviolet rays having a wavelength of 172 nm and its vicinity. As a result, active oxygen atoms are generated near the surface of the optical fiber 50, and the surface of the optical fiber 50 is cleaned by a normal mechanism. Since the radiation surface of the dielectric barrier discharge lamp of the present invention is linear and high-intensity ultraviolet rays can be obtained, cleaning can be performed at high speed with high light utilization rate.

In the sixth embodiment of the present invention, the discharge gas for the dielectric barrier discharge in the fifth embodiment is a mixed gas of xenon and chlorine, and the surface of the optical fiber 50 is coated with a photocurable resin. The photocurable resin is cured. The photocurable resin on the surface of the optical fiber 50 is irradiated with high brightness at 302 nm and ultraviolet rays in the vicinity thereof emitted from the excimer molecule composed of xenon and chlorine, and the photocurable resin is efficiently cured. Although one dielectric barrier discharge lamp was used in the fifth and sixth embodiments,
By irradiating ultraviolet rays from different directions using a plurality of dielectric barrier discharge lamps, the uniformity in the circumferential direction is improved and the processing can be performed at high speed.

FIG. 6 shows a schematic view of the surface modification method of the seventh embodiment of the present invention. The same dielectric barrier discharge lamp 6 as the flat dielectric barrier discharge lamp shown in the third embodiment.
A roller 62 is provided in parallel with the condenser lens 10 of No. 1 and has a polyethylene film 63 as a surface-modified product.
Is installed in an atmosphere containing oxygen. By the condenser lens 10 of the dielectric barrier discharge lamp 61, the roller 62
The wavelength of 172 nm and ultraviolet rays in the vicinity thereof are concentrated and applied to the surface of the polyethylene film 63 that is in close contact with the.
As a result, the surface of the polyethylene film is modified by the usual mechanism. Since the radiation surface of the dielectric barrier discharge lamp of the present invention is linear, it is easy to keep the distance between the surface of the polyethylene film and the dielectric barrier discharge lamp constant, and since high-intensity ultraviolet rays can be obtained, uniformly,
In addition, the surface can be modified at high speed.

[0019]

As described above, according to the present invention, the brightness is high, the spatial distribution of the light output is uniform, the efficiency is high, and
A dielectric barrier discharge lamp having a stable light output can be provided. Furthermore, by using the dielectric barrier discharge lamp of the present invention, it becomes possible to uniformly and rapidly process flat, film and linear objects.

[Brief description of drawings]

FIG. 1 is an illustration of an embodiment of a dielectric barrier discharge lamp of the present invention, shown from the side.

FIG. 2 is an explanatory view showing the lamp of FIG. 1 from the front.

FIG. 3 is an explanatory diagram of a window member.

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

FIG. 5 is an explanatory view of a cleaning method using the dielectric barrier discharge lamp of the present invention.

FIG. 6 is an explanatory diagram of a surface modification method using the dielectric barrier discharge lamp of the present invention.

[Explanation of symbols]

 1 Window Member 2,3 Dielectric 4,5 Electrode 6,8a, 8b Side Plate 9a, 9b, 9c Reflective Film 10 Condensing Lens 11 Discharge Space 22 Power Supply 50 Optical Fiber 63 Polyethylene Film

Claims (7)

[Claims] 1. A discharge vessel is filled with a discharge gas that forms excimer molecules by a dielectric barrier discharge, and a part of the discharge vessel also serves as a dielectric of the dielectric barrier discharge.
A dielectric barrier discharge lamp having a light extraction window member provided in parallel with a discharge path of the dielectric barrier discharge, wherein a condenser lens is provided in the immediate vicinity of the light extraction window member. Barrier discharge lamp. 2. A discharge vessel is filled with a discharge gas for forming excimer molecules by a dielectric barrier discharge, and a part of the discharge vessel also serves as a dielectric of the dielectric barrier discharge.
In a dielectric barrier discharge lamp having a light extraction window member provided in parallel with a discharge path of the dielectric barrier discharge, the light extraction window member also serves as a condenser lens. Discharge lamp. 3. A dielectric barrier discharge lamp according to claim 1, wherein a light reflecting film is provided on the tube wall of the discharge vessel which is in the direct vicinity of the light extraction window member and is parallel to the discharge path. . 4. The dielectric according to claim 1, wherein the length H parallel to the discharge path of the light extraction window member exceeds the discharge path length L of the dielectric barrier discharge. Barrier discharge lamp. 5. A method for treating a linear object, which comprises using the dielectric barrier discharge lamp according to any one of claims 1 to 4. 6. A method of treating a flat article, which uses the dielectric barrier discharge lamp according to any one of claims 1 to 4. 7. A method for treating a film-like material, wherein the dielectric barrier discharge lamp according to claim 1 is used.