JPH0527946B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microwave discharge light source device that has been improved so that the generated light can be used in a preferable manner.

[Conventional technology]

As a light source device using microwave discharge, for example, there is a light source device proposed in Japanese Patent Application No. 59-39980 as shown in FIG. In the figure, 1 is a magnetron which is a microwave oscillator, 2 is a magnetron antenna, 3 is a waveguide with this microwave oscillator attached to its end, 5 is a microwave resonant cavity, and the other end of the waveguide 3 It is composed of a cavity wall 6 connected to a cylindrical metal mesh and a light-transmitting member 7 made of a cylindrical metal mesh. Reference numeral 8 denotes a power feeding port provided in the cavity wall 6, which feeds microwaves from the waveguide 3 into the microwave resonant cavity 5. Reference numeral 9 denotes a spherical lamp disposed within the microwave resonant cavity 5, which is filled with a rare gas, mercury, etc., and is made of a transparent material such as quartz glass. Reference numeral 91 denotes a lamp support extending from the outer wall of the lamp 9, which is also made of a dielectric material such as quartz glass.
The lamp 9 is fixed to the cavity wall 6 with a lamp fixing screw 10. 11 is a light reflection plate that reflects the light emitted from the microwave resonance cavity 5; 12 is a cooling fan that cools the magnetron 1 and the lamp 9; 4 is a ventilation port that guides cooling air into the waveguide; It is a box that covers the whole thing.

The operation of this device is as follows. The microwave oscillated by the magnetron 1 is excited as a propagation mode from the magnetron antenna 2 to the waveguide 3. This microwave is transmitted to the cavity wall 6 through the power supply port 8.
Power is supplied to the microwave resonant cavity 5 surrounded by the light transmitting member 7 and the light transmitting member 7. The rare gas in the lamp 9 is discharged by this microwave, and the lamp wall is heated by this energy, and the enclosed mercury etc. evaporate and gasify, and the discharge is mainly a discharge of metal gas such as mercury. It emits light in a spectrum depending on its type.

The light-transmitting member 7 acts to reflect microwaves like metal, and the light is transmitted through the mesh openings. In other words, it acts as an opaque body for microwaves and as a transparent body for light. Therefore, the light from the lamp 9 is radiated out from the microwave resonant cavity 5 and the light reflecting plate 11
reflected. The light reflecting plate 11 is designed in various shapes depending on the use of light.

[Problem that the invention seeks to solve]

In the conventional microwave discharge light source device as described above, the waveguide 3 extends rearward in the light emission direction and occupies a large amount of space at the rear. Therefore, the distance between the light source and the surface to be irradiated becomes closer, and the light rays become spread out at the ends of the surface to be irradiated, causing the problem that satisfactory performance cannot be obtained in devices that require parallel light.

The present invention was made to solve this problem, and an object of the present invention is to provide a microwave discharge light source device in which the depth of the device can be made shallow so that the distance between the light source and the surface to be irradiated does not become close.

[Means for solving problems]

The microwave discharge light source device according to the present invention has a power supply port provided on the opposite side to the light emission direction, and the direction of the waveguide axis on the side where the microwave oscillator is attached.
The planes of the feed ports are not perpendicular to each other, and the microwave oscillator and microwave resonant cavity are provided on the same side of the waveguide.

[Effect]

The microwave discharge light source device in this invention includes:
The configuration is such that the waveguide does not extend behind the microwave resonant cavity having the lamp, reducing the depth of the device.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part of a microwave discharge light source device according to an embodiment of the present invention, and the direction of the plane of the power supply port 8 and the axis of the waveguide on the side where the magnetron 1 is attached are not perpendicular to each other. In addition, a corner portion is provided in the waveguide 3. 31 indicates a corner portion of such a waveguide. Here, the waveguide 3 is a rectangular waveguide, and FIG. 1 is a cross-sectional view perpendicular to the electric field E, and the corner portion is the E corner. On the other hand, Figure 2 shows the waveguide shown in Figure 1, the electric field E in the resonant cavity, and the magnetic field H.
FIG. In the figure, the solid line E
indicates electric lines of force, that is, an electric field, and small circle H indicates lines of magnetic force, that is, a magnetic field. Also, here, the microwave resonant cavity 5 has a cylindrical shape. The mode in the waveguide 3 is a square TE ₁₀ mode, and the microwave resonant cavity 5
The mode inside is excited as a cylindrical TE ₁₁₁ mode, that is, a mode with one peak of electromagnetic field in every direction. In the TE ₁₀ mode in the waveguide 3, the directions of both the electric and magnetic fields are changed at the corner 31 as shown in the figure. In this case, the angle θ of the corner portion 31 is
The angle is set at 45°, and the directions of the electric and magnetic fields are changed to right angles. Therefore, the electromagnetic field mode on the waveguide side of the power feed port 8 is generated even if the waveguide length shown in Fig. 2 is 1/
Even short wavelengths of less than 4 tube wavelengths result in a mode very close to TE ₁₀ . Therefore, the same cylindrical microwave resonant cavity as the proposed example shown in FIG. 5 can be used as the microwave resonant cavity in the configuration of the present invention. That is, from the TE ₁₀ mode of the rectangular waveguide,
The TE ₁₁₁ mode of the cylindrical resonant cavity can be excited well as shown in Figure 2. However, if is small, the mode on the waveguide side is not exactly the same as TE ₁₀ , so the shape of the feed port may need to be slightly different from that in Figure 5, but the cavity is the same. Things can be used.

As an example, the waveguide 3 has a rectangular cross-sectional shape of 95 mm x 54 mm, which is the same as that proposed in Japanese Patent Application No. 59-39980, and the microwave resonant cavity 5 is a cylindrical cavity with a diameter of 80 mm and a height of 90 mm. Lamp 9 is a sphere with a diameter of 30 mm, filled with 60 torr of Ar and 100 mg of Hg.
As the corner of the waveguide, θ in Fig. 2 is 45°,
As a result of using a microwave with a frequency of 8 mm and a power of 800 W, it took about 5 seconds to reach a steady state after exciting with a microwave with a frequency of 2450 MHz and a power of 800 W. The matching state between the waveguide and the microwave resonant cavity was steady, and the microwave power Reflection coefficient is 0.1
It was as follows. By using the corner portions in this manner, good characteristics can be obtained even if the distance from the corner portions to the power feeding port is short, or even if the above distance is zero.
In other words, it is thought that a mode other than the basic mode TE ₁₀ is mixed in at the power supply port position.
It was found that good characteristics can be obtained even when the wavelength is less than 2 tube wavelengths.

When the microwave discharge light source device having the above configuration is used as a light source of a film transfer device, the operation is as follows. FIG. 3 is a schematic diagram of the film transfer device, in which a microwave discharge light source device 17 or 18 is installed in a frame 14. The microwave discharge light source device 17 shown by the dotted line is the fifth one proposed earlier.
The microwave discharge light source device 18 shown by the solid line is the one shown in FIG. 1 according to the present invention, which is turned upside down. A transfer film 15 and a transfer film 16 are placed on top of each other on the upper surface of the frame 14, and the transfer film 16 is exposed to light from a light source device, so that the transfer film 15 is transferred onto the transfer film 16. The transferred film 15 may be a stack of several sheets for editing. In such a case,
Since the transferred film is thick, unless the light beam is perpendicular to the film surface, the image transferred to the transfer film 16 will be blurred. Therefore, the light beam is required to be as perpendicular to the film surface as possible, that is, to be close to parallel light. When the previously proposed microwave discharge light source device 17 is used, since the light source is located high, the light beam spreads as shown by the dotted arrow line, resulting in a light beam that is considerably deviated from parallel light. On the other hand, when the microwave discharge light source device 18 according to the present invention is used, the position of the light source can be lowered, so that the light rays irradiated onto the irradiated surface become more parallel light, as shown by the solid arrow line. becomes. Therefore, the transferred image is less blurred and high-quality transfer is possible.

FIG. 4 is a sectional view of a main part of a microwave discharge light source device according to another embodiment of the present invention. In the figure, the microwave resonant cavity 5 is composed of a rotationally symmetrical cavity wall 61 that also serves as a light reflection plate and a light transmitting member 7, and a spherical lamp 9 is supported from both sides by two support rods 91. ing. For this device,
The electromagnetic field mode excited in the microwave resonant cavity 5 is different from that in Fig. 1, but it is still caused by the waveguide.
Using a mode excited by the TE ₁₀ mode, it is possible to excite even if the waveguide has a corner portion 31.
Therefore, by using the corner portion, the depth of the light source with respect to the light irradiation direction can be made shallow, and the same effect as that shown in FIG. 1 can be obtained.

In the above two embodiments, an E corner is used as the corner portion, but an H corner may be used, and the same effect as in the above embodiment can be obtained.

Furthermore, in each of the above embodiments, the direction of the waveguide axis on the side where the microwave oscillator is installed is parallel to the surface of the feed port, but there is a configuration in which the two are not parallel but diagonal. However, it often has the effect of making the depth shallower. In this case, it is also possible to obtain a predetermined mode.

〔Effect of the invention〕

As explained above, this invention provides a power feed port on the side opposite to the light emission direction, and the direction of the waveguide axis on the side where the microwave oscillator is attached is not perpendicular to the surface of the power feed port. Since the wave oscillator and the microwave resonant cavity are installed on the same side of the waveguide, the depth of the device can be made shallow, and the distance between the light source and the irradiated surface can be increased in a limited space. This has the effect of obtaining parallel light rays. Furthermore, the device itself has the effect of being compact, easy to attach to the housing, and space-efficient. In addition, the lamp can be cooled uniformly, which allows more microwave power to be input, which has the effect of producing stronger light.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing a microwave discharge light source device according to an embodiment of the present invention, and FIG. 2 is a diagram showing microwave excitation from a waveguide to a microwave resonant cavity according to an embodiment of the present invention. Partial sectional view showing 3rd
The figure is a schematic configuration diagram showing a film transfer device using a microwave discharge light source device according to an embodiment of the present invention, and FIG. 4 is a sectional view of essential parts showing a microwave discharge light source device according to another embodiment of the present invention. FIG. 5 is a sectional view of a main part of the previously proposed microwave discharge light source device. 1... Magnetron, 3... Waveguide, 5... Microwave resonant cavity, 7... Light transmitting member, 8...
Power supply port, 9... lamp, 31... corner section. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A waveguide having a microwave oscillator attached to its end, microwaves being supplied from the other end of the waveguide through a power supply port, and having a light-transmitting member on at least a part of the wall surface. and a lamp disposed within the microwave resonant cavity, the power supply port is provided on the side opposite to the light emitting side, and the microwave oscillator is attached. The direction of the waveguide axis on the side where the waveguide is connected is not perpendicular to the plane of the feed port, and the microwave oscillator and the microwave resonance cavity are provided on the same side with respect to the waveguide. Microwave discharge light source device. 2. The microwave discharge light source device according to claim 1, wherein the waveguide is provided with a corner portion. 3. The microwave discharge light source device according to claim 2, wherein the corner portion of the waveguide is an E corner. 4. The microwave discharge light source device according to claim 2, wherein the corner portion of the waveguide is an H corner. 5 The waveguide length from the corner to the feed port is 1/2
4. The microwave discharge light source device according to claim 3, wherein the wavelength is equal to or less than the tube wavelength.