JPH0610971B2 - Microwave discharge device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave discharge device, and more particularly to a mechanism for causing a discharge tube for generating ultraviolet rays or the like to discharge with microwaves without electrodes.

[Conventional technology]

A photoresist for forming a circuit pattern on a semiconductor, a certain kind of paint, or the like can be rapidly cured or insolubilized when irradiated with ultraviolet rays. Ultraviolet rays are also widely used for sterilization and the like. A gas-filled discharge tube is generally used to generate the ultraviolet rays and the like.

In a conventional discharge tube, a metal electrode is enclosed and a voltage is applied to the metal electrode to generate a discharge. Therefore, it was not possible to apply a power higher than the power resistance of the electrode, and a high output could not be obtained. In addition, since corrosive gases such as halogens and halides cannot be filled, the types of filling gas that can be used are limited,
There is also a problem that a desired spectrum component cannot be obtained.

[Problems to be solved by the invention]

The present invention focuses on the fact that various drawbacks of the conventional discharge tube are mainly caused by the enclosed metal electrode, and provides a microwave discharge device in order to solve those problems by the electrodeless discharge tube. The purpose is to

[Means for solving problems]

In order to achieve the above object, the present invention provides an electrodeless discharge tube in which a dielectric is filled with a gas, which is inserted and installed in the maximum electric field of a ridge type waveguide, and a microwave is introduced into this waveguide. , Proposes a microwave discharge device for generating discharge without electrodes.

[Operation of the invention]

FIG. 2 is a perspective view of a ridge type waveguide. In the figure, a ridge 2 is formed inside a waveguide 1, and an electric field is concentrated on the ridge 2 as indicated by a dotted line of electric force. When a discharge tube filled with gas is inserted into the strong electric field portion of this ridge, the gas is given energy and discharged. Therefore, it is not necessary to seal the metal electrode.

It is also conceivable to use a cavity resonator to generate microwave discharge. However, in the cavity resonator, the microwave becomes a standing wave, so that a long arc tube cannot uniformly emit light. On the other hand, since the microwave in the ridge type waveguide used in the present invention is a traveling wave, it is possible to cause a long arc tube to emit light uniformly.

Example of Invention

Next, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view of a microwave discharge device according to the present invention. In the figure, 1 is a waveguide, 2 is a ridge, 3 is a discharge tube, and 4 is a mesh structure portion provided on the waveguide wall. The discharge tube 3 is inserted in the strong electric field portion of the ridge 2.

Here, the upper surface 2A of the ridge electrode that is in contact with the gas-filled discharge tube 3 is a curved surface that collects light such as a parabolic surface. By doing so, it is efficient and convenient to project the light emitted by the discharge onto the target in the direction of the arrow.

Further, the mesh structure 4 provided on the waveguide wall facing the ridge 4
Has a pitch that allows emitted light to pass through but cuts off microwaves. As a result, the emitted light can be used without the microwave leaking to the outside.

In this embodiment, since the metal electrode is not enclosed in the gas-filled discharge tube 3, high power resistance and high output light can be obtained. In addition, since corrosive gases such as halogens and halides can be freely enclosed, the types of usable enclosed gases are expanded, and light having a desired spectral component can be used.

〔The invention's effect〕

 According to the present invention, the following effects can be obtained.

(1) Since it is an electrodeless discharge in which a metal electrode is not enclosed in the discharge tube, the withstand power is increased and high-power light can be extracted.

(2) Encapsulating a corrosive gas such as halogen, the spectrum component which has not been used conventionally can be obtained.

(3) Since a ridge type waveguide is used and the microwave in this waveguide is a traveling wave, it is possible to emit light even in a long arc tube.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a microwave discharge device of the present invention using a ridge type waveguide and an electrodeless discharge tube, and FIG. 2 is a perspective view showing a state of an electric field of the ridge type waveguide used in the present invention. . DESCRIPTION OF SYMBOLS 1 ... Ridge type waveguide, 2 ... Ridge 2A ... Ridge upper surface, 3 ... Gas-filled discharge tube 4 ... Waveguide wall mesh structure

Claims (2)

[Claims] 1. A ridge type waveguide, and a discharge tube formed by enclosing a gas in a dielectric and inserted and installed in the maximum electric field of the ridge type waveguide. A microwave discharge device characterized in that a discharge is generated by the generated microwave. 2. The microwave discharge device according to claim 1, wherein the upper surface of the ridge is formed into a curved surface having a light-collecting property, and the waveguide wall facing the ridge surface is light-transmissive and does not allow microwaves to pass therethrough. A microwave discharge device having a mesh structure.