JPS62105356A - Microwave discharge light source device - Google Patents

Abstract

PURPOSE:To obtain a microwave discharge light source device which can increase the radiating quantity of light to the outside by arranging a microwave bandpass filter for passing the basic wave component of microwave energy while suppressing/attenuating other higher harmonic components in a waveguide. CONSTITUTION:Microwave energy oscillated from a magnetron 1 contains main basic wave component in a microwave circuit system and unnecessary higher harmonic components having integer times of frequency of the basic wave. When passing through a microwave bandpass filter 15 and a waveguide, the higher harmonic component microwave energy is suppressed and attenuated and only the basic wave component is led to a microwave resonant cavity 5. Consequently, the opening rates and the arranging gaps of the first and the second metal mesh boards 7, 8 are not required to match with the higher harmonic components of the microwave for the purpose to prevent leakage of the microwave energy but can be set to the basic wave component resulting in increase of the opening rate and the radiating quantity of light to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microwave discharge light source device that utilizes microwave discharge.

[Conventional technology]

FIG. 2 is a sectional view showing a conventional microwave discharge light source device disclosed in, for example, Japanese Utility Model Application Publications No. 58-192458. In the figure, 1 is a magnetron that oscillates microwaves, 2 is a magnetron antenna, 3 is a waveguide having a ventilation port 3a that carries the microwaves from the antenna 2, and 4 is a cavity that constitutes a microphone A-wave resonant cavity 5. At the body wall, the microwave from the waveguide 3 is fed into the resonant cavity 5 through the feed port 6. Reference numeral 7 denotes a first metal mesh plate that closes the openings 1 to 1 of the cavity wall 4; 8, a ring-shaped spacer 9 is provided on the outer side of the first metal mesh plate 7; This is a second metal mesh plate fixed with screws 11 together with the ring-shaped fixing frame 10 stacked on top of the frame. 12 is a spherical electrodeless lamp arranged in the microwave resonant cavity 5; 13 is a magnetron 1;
and a fan for cooling the electrodeless lamp 12, and 14 is a casing that accommodates each of the above-mentioned components.

The conventional microwave discharge light source device is constructed as described above, and the microwave oscillated from the magnetron 1 is fed from the antenna 2 through the waveguide 3 and radiated into the microwave resonant cavity 5 from the 1°C opening 6. Ru. The gas enclosed within the electrodeless lamp 12 is excited to discharge and emit light by this microwave. This light is then radiated to the outside according to the aperture ratio of the first and second metal mesh plates 7.8. On the other hand, since the energy of microwaves is greatly attenuated by being reflected by a metal mesh plate, leakage of microwaves from the first metal mesh plate 7 is reflected by the second metal mesh plate 8 and attenuated. Therefore, by appropriately selecting the aperture ratio and installation gap of both metal mesh plates 7 and 8, leakage of microwave energy is prevented and the amount of light emitted to the outside is increased.

[Problem that the invention seeks to solve]

In the conventional microwave discharge light source device as described above, depending on the aperture ratio and installation gap of both metal mesh plates 7 and 8,
In order to prevent the microwave energy from the fundamental wave to the harmonics generated by the magnetron 1 from leaking to the outside, the aperture ratio of the metal mesh plates 7 and 8 is set so that the harmonics of the microwave energy are high. Therefore, the aperture ratio of both metal mesh plates 7 and 8 must be made small from the general characteristics of microwave shielding. For this reason, the conventional microwave discharge light source device has a problem in that the amount of light emitted to the outside is reduced.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a microwave discharge light source device that can increase the amount of light emitted to the outside.

[Means for solving problems]

The microwave discharge light source device according to the present invention is provided with a microwave bandpass filter in the waveguide that passes the fundamental wave component of microwave energy and suppresses and attenuates microwave energy of other harmonic components. be.

[For production]

In this invention, since the microwave band-pass filter is provided, the microwave energy of harmonic components other than the fundamental wave component is suppressed and attenuated. It is possible to match the frequency of the fundamental wave component.

〔Example〕

FIG. 1 is a sectional view showing a microwave discharge light source device according to an embodiment of the present invention. In the figure, 1 to 14 are the second
Since it is similar to the conventional device shown in the figure, corresponding parts are given the same reference numerals and their explanation will be omitted. Further, 15 is connected to be located in the middle of the waveguide 3, and allows the microwave energy of the fundamental wave component, which is the oscillation frequency of the magnetron 1, to pass therethrough, and suppresses and attenuates the microwave energy of other harmonic components. It is a microwave bandpass filter.

The microwave discharge light source device configured as described above performs the basic operation as already explained in connection with the conventional device, and the gas in the electrodeless lamp 12 is discharge-excited by microwave energy to emit light. In this case, the microwave energy oscillated from the magnetron 1 includes a main fundamental wave component for the microwave circuit system and unnecessary harmonic components that are integral multiples of the frequency of the fundamental wave.

The microwave energy of this harmonic component is suppressed and attenuated when passing through the waveguide 3 via the microwave bandpass filter 15, and only the fundamental component is guided to the microwave resonant cavity 5. This eliminates the need to match the aperture ratio and installation gap of the first metal mesh plate 7 and the second metal mesh plate 8 to the harmonic components of the microwave to prevent leakage of microwave energy. Can be set. Therefore, the aperture ratio can be increased and the amount of light emitted to the outside can be increased.

〔Effect of the invention〕

As explained above, this invention is a microwave bandpass filter that allows the fundamental wave component of microwave energy oscillated from a magnetron to pass through a waveguide, and suppresses and attenuates other unnecessary harmonic components of microwave energy. Since the microwave energy is provided with a first
and the aperture ratio of the second metal mesh plate can be made to match the frequency of the fundamental wave component at which the aperture ratio is maximum,
This has the effect of increasing the amount of light radiated to the outside and reliably preventing leakage of microwave energy to the outside.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a microwave discharge light source device according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional microwave discharge light source device IT. DESCRIPTION OF SYMBOLS 1... Magnetron, 3... - Waveguide, 5... Microwave resonance cavity, 7... First metal mesh plate, 8...
... second metal mesh plate, 12 ... electrodeless lamp,
15...Microwave band pass filter. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] An electrodeless lamp is disposed in a microwave resonant cavity provided with a metal mesh plate on at least one surface, and the electrodeless lamp is connected to the microwave cavity by transmitting microwaves oscillated by a magnetron through a waveguide. In a microwave discharge light source device that is lit by a microwave electromagnetic field formed inside the body, a fundamental wave component of microwave energy is passed through the waveguide, and microwave energy of other harmonic components is suppressed and attenuated. A microwave discharge light source device characterized in that a microwave bandpass filter is provided.