JPH0226359B2 - - Google Patents

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]

BACKGROUND ART Recently, light source devices that use high-frequency discharge, particularly microwaves as high-frequency waves, have been attracting attention as light source devices that utilize electric discharge. In conventional light source devices with electrodes, the life of the lamp is determined by the wear and tear of the electrodes, but in light source devices using microwaves, the lamp can be made electrodeless, so the lamp life can be extended.

Furthermore, since there is no heat loss due to electrodes, and the difference in discharge impedance is small between the initial state and the stable state, it is easy to inject power in the initial state even when impedance matching is performed in the stable state. Another characteristic is that the time it takes to reach maximum output is short because the power is concentrated on the lamp tube wall.

FIG. 1 is a longitudinal cross-sectional view showing the configuration of a microwave discharge light source device according to the prior invention of the present inventors utilizing these features, in which 1 is a magnetron, 2 is a magnetron antenna, 3 is a waveguide, and 4 is a magnetron antenna. 44 is a microwave resonant cavity having a structure in which a portion of the inner wall that forms a reflective surface is formed as a spherical surface 41, a portion that follows it is formed as a cylindrical surface 42, and the surface that becomes the light passing surface is covered with a metal mesh plate 43; A light anti-reflection treatment layer covering the cylindrical surface 42, 5 a microwave power feed port provided at the junction of the cavity 4 and the waveguide 3, 6 a spherical discharge lamp, and 61 a tube of the discharge lamp 6. A supporting protrusion formed on the wall, 7 indicates a magnetron 1 and a discharge lamp 6.
8 is a vent provided in a part of the waveguide 3; 10 is a box housing the magnetron 1, the waveguide 3, the cavity 4, etc.; 11 is a projection 61;
This is a support rod that supports the discharge lamp 6 by fitting into it.

The operation of this device is as follows. Microwaves generated by the magnetron 1 are radiated into a waveguide 3 through a magnetron antenna 2.
This microwave propagates through the waveguide 3 and feeds into the feed port 5.
is radiated into the cavity 4 through the microwave, forming a microwave electromagnetic field within the cavity 4. Due to this microwave electromagnetic field, the gas in the discharge lamp 6 is discharged, the inner wall of the discharge lamp is heated, the metal such as mercury in the tube is evaporated and gasified, and the discharge shifts to a discharge of metal gas. At this time, light with a specific emission spectrum depending on the type of metal is generated, and this is used as a light source. In order to effectively utilize the light from the discharge lamp 6, the spherical part of the cavity 4 is used as a reflector, and the front surface is made up of a metal mesh plate 43 that blocks microwaves but transmits light, so that the light is directed only in the front. radiate to. On the other hand, since the magnetron 1 and the discharge lamp 6 need to be cooled during operation, they are blown by a cooling fan 7, and this cooling air passes through the vent 8, the waveguide 3, and the power supply port 5, cools the lamp 6, and then cools the mesh. Air is exhausted from the plate 10.

[Problem to be solved by the invention]

In the microwave discharge light source device as described above, the waveguide 3 is connected to a position facing the surface of the metal mesh plate 10. That is, the microwave transmission direction of the waveguide 3 and the surface of the metal mesh plate 10 are perpendicular. For this reason, there is a drawback that the waveguide 3 extends in a direction opposite to the direction in which light is extracted, and occupies a large amount of space at the rear.

This invention was made in order to solve the problem of not being able to lower the height of the device as described above, and is configured so that a waveguide is connected to the side surface and a magnetron is also arranged on the side of the cavity. In this way, it is an object of the present invention to provide a microwave discharge light source device that can reduce the height of the device.

[Means to solve the problem]

A magnetron, a waveguide, a spherical cavity with a reflective surface on its inner wall, a spherical electrodeless discharge lamp installed in the center of the cavity and filled with metal, and a spherical electrodeless discharge lamp installed in the front of the cavity. A microwave discharge light source device having a metal mesh plate that transmits light, characterized in that the waveguide is connected to a side surface of the cavity, and the magnetron is also arranged on a side of the cavity. Microwave discharge light source device.

〔Example〕

FIG. 2 is a longitudinal sectional view showing the structure of an embodiment of the present invention, and the same reference numerals as in FIG. 1 indicate the same parts.

In the above embodiment, the shape of the cavity is a combination of a spherical surface and a cylindrical surface, but even if the shape is other than that, the same operation will occur if the configuration is such that power is supplied from the side surface.

As described above, in a device configured to feed power from the side, there is no need to connect a waveguide at the rear and a large space is not required, so the thickness of the device can be reduced.

〔Effect of the invention〕

This invention is configured to introduce microwaves from a microwave oscillator into a cavity housing an electrodeless discharge lamp using a waveguide, and to emit light through a metal mesh plate forming the front surface of the cavity. wherein the waveguide is connected to a side surface of the cavity,
Moreover, the magnetron is also arranged on the side of the cavity, which reduces the thickness of the device and has the effect of increasing the distance between the object to be irradiated and the light source in a limited space.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the structure of a microwave discharge light source device according to the prior art, and FIG. 2 is a longitudinal sectional view showing the structure of an embodiment according to the present invention. In the figure, 1 is a magnetron, 3 is a waveguide,
4 is a cavity, 6 is an electrodeless discharge lamp, and 43 is a metal mesh plate. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A magnetron, a waveguide, a spherical cavity with a reflective surface on its inner wall, a spherical electrodeless discharge lamp provided in the center of the cavity and filled with metal, and a spherical electrodeless discharge lamp provided in the front of the cavity. In a microwave discharge light source device having a metal mesh plate that transmits emitted light,
the waveguide is connected to a side surface of the cavity, and
A microwave discharge light source device characterized in that the magnetron is also arranged on a side of the cavity.