JPS6336082B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microwave discharge light source device that utilizes light emission by microwave discharge.

Figure 1 shows a conventionally proposed microwave discharge light source device. In the figure, 1 is a magnetron that generates microwaves, 2 is a magnetron antenna of this magnetron, and 3 is a transmitter that transmits microwaves radiated from this antenna 2. 4 is a cavity wall connected to the end of the waveguide 3 via the microwave feed port 12, and the cavity wall 4 is connected to the spherical part 5 and extends around the opening 4a. It consists of a cylindrical part 6 having a flange part 10 bent outward, and is made of aluminum or the like. Reference numeral 7 denotes a metal mesh plate that closes the opening 4a of the cavity wall 4, and the metal mesh plate 7 is attached to a presser flange 8, which serves as a presser metal fitting, which is stacked on top of the metal mesh plate 7. It is tightened to 10. The metal mesh plate 7 blocks microwaves but allows light to pass through, and forms a microwave cavity 11 together with the cavity wall 4. Reference numeral 13 denotes a spherical electrodeless discharge lamp disposed near the center of the spherical portion 5 of the cavity wall 4, and is made of quartz glass, etc., and contains a rare gas such as argon, a metal such as mercury or iron, iodine, etc. contains halogen. Reference numeral 14 denotes a projection provided on a part of the outer wall of the discharge lamp 13, which is made of a low-loss dielectric material such as quartz glass, and one end of which is inserted and supported by the discharge lamp support portion 17 formed on the top of the spherical portion 5 of the cavity wall 4. The discharge lamp 13 is fitted into a flared support part 16 formed at the other end of a cylindrical support body 15, thereby supporting the discharge lamp 13. Reference numeral 18 denotes a lens for condensing the light emitted from the metal mesh plate 7 to the outside onto an irradiated surface (not shown).

Next, the operation will be explained. When the power is turned on, the magnetron 1 generates microwaves, which are radiated into the waveguide 3 through the antenna 2. The microwave propagates through the waveguide 3 and is radiated into the microwave cavity 11 through the feed port 12, forming a microwave electromagnetic field within the cavity 11. The rare gas in the discharge lamp 13 is discharged by this microwave electromagnetic field, and the inner wall of the discharge lamp 13 is heated. Therefore, mercury, iron, etc. in the discharge lamp 13 become halides and evaporate, and the discharge is mainly a discharge of metal gas, and light having a specific emission spectrum depending on the type of metal enclosed is emitted. The discharge at this time occurs near the tube wall of the discharge lamp 13. That is, the light emitted from the discharge lamp 13 has a spherical shape. Therefore, if the spherical part 5 of the cavity wall 4 is made a light reflecting surface, the reflected light will pass near the discharge lamp 13 again since the discharge lamp 13 is located near the center of the spherical part 5. This reflected light and discharge lamp 13
The direct light is emitted outward through the metal mesh plate 7. The light emitted outward is then focused by a condensing lens 18 onto a necessary irradiated surface.

Figure 2 is an enlarged view of the installation of the metal mesh plate 7.
Contact surface 7a of metal mesh plate 7 and flange portion 10
The contact surface 10a of the cap screw 9 is pressed into electrical contact with the contact surface 10a of the cap screw 9. Therefore, if the contact is not made completely over the entire circumference, discharge due to microwaves will occur in the parts where the contact is incomplete, and microwaves may leak to the outside of the microwave cavity 11. When using microwaves with high power, the contact surface 10a of the flange portion 10 and the contact surface 8a of the presser flange 8 must be machined into highly accurate flat surfaces to produce a contact effect. Further, a large number of holding screws 9 are required all around the circumference.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and by interposing an elastic body between the metal mesh plate and the holding flange, the contact surface 10a of the flange part can be finished flat. It is an object of the present invention to provide a microwave discharge light source device that does not require the following and does not leak microwaves even when the number of retaining screws 9 is small.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 3, an elastic body 20 is interposed between the metal mesh plate 7 and a holding flange 8 serving as a holding fitting. This elastic body 20 is preferably a packing material made of silicone rubber. By interposing the elastic body 20 in this way, the contact surface 10a of the flange portion 10 and the contact surface 8 of the presser flange 8
Even if a is a rough surface, by tightening the presser flange 8 with the presser screw 9, the elastic body 20 can
is crushed, while the concave portion is not crushed, so that the contact surface 7 of the metal mesh plate 7
a can be brought into complete electrical contact with the contact surface 10a of the flange portion 10 over the entire circumference. As a result, no gap is created between the contact surfaces 7a and 10a, so that the microwaves within the microwave cavity 11 do not cause discharge between the contact surfaces, and the microwaves do not leak to the outside. Further, the number of retaining screws 9 can be reduced over the entire circumference. For example, if the diameter of the microwave cavity 11 is 130 mm, only three holding screws are required.

FIG. 4 shows another embodiment of the elastic body. This elastic body is made of a spring plate 21. In this case as well, the contact surface 7a of the metal mesh plate 7 and the contact surface 10 of the flange portion 10 are similar to the silicone rubber gasket.
Contact with a can be made completely over the entire circumference.

FIG. 5 shows another tightening means in place of the cap screw 9. As this tightening means, for example, catch clips 30 manufactured by Takigen Manufacturing Co., Ltd. are used at several locations around the entire circumference. This clip 30
A latch 31 is attached to the outside of one flange portion 10, and a hook portion 33 to which a band 32 of the latch 31 is latched is provided on the other presser flange 8. Even if the clip 30 described above is used, the presser flange 8 can be tightened to the flange portion 10 and the contact surface 7a of the metal mesh plate can be brought into good contact with the contact surface 10a of the flange portion 10, so the presser screw 9
Instead, the metal mesh plate can be easily attached and detached. Although FIG. 5 shows an example in which the elastic body 20 is a silicone rubber gasket, it may also be a spring plate 21.

As described above, according to the present invention, the cavity wall has an opening on at least one side and a flange is provided around the opening, and a metal mesh plate is placed over the flange so as to close the opening. In a microwave discharge light source device equipped with a microwave cavity mounted with a holding fitting and an electrodeless discharge lamp inside this cavity, an elastic body is interposed between the metal mesh plate and the holding fitting. , the contact between the metal mesh plate and the flange part of the microwave cavity wall is perfect, and as a result, there is no need for precision on the contact surface of the metal mesh plate or the contact surface of the flange part, and even simple tightening means can prevent discharge and microwave This has the effect of preventing leakage.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the configuration of a conventional microwave discharge light source device, Fig. 2 is a sectional view of the installation of a metal mesh plate, Fig. 3 is a sectional view similar to Fig. 2 according to the present invention, and Fig. 4 is another sectional view. FIG. 5 is a cross-sectional view of another embodiment of the tightening means. 4...Cavity wall, 7...Metal mesh plate, 8...
Holder flange, 9... Holder screw, 10... Flange portion, 11... Microwave cavity, 13... Electrodeless discharge lamp, 20... Elastic body, 21... Spring plate, 30
...Crip. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A cavity wall having an opening on at least one side and a flange provided around the opening holds a metal mesh plate that overlaps the flange and closes the opening. In a microwave discharge light source device comprising a microwave cavity mounted using a metal fitting and a fastening means, and an electrodeless discharge lamp inside the microwave cavity, an annular shape is provided between the metal mesh plate and the holding metal fitting. A microwave discharge light source device characterized by interposing an elastic body. 2. The microwave discharge light source device according to claim 1, wherein the annular elastic body is made of silicone rubber. 3. The microwave discharge light source device according to claim 1, wherein the annular elastic body is made of a spring plate.