JPS6336081B2 - - 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. This microwave then propagates through the waveguide 3 and passes through the feed port 12 into the microwave cavity 11.
radiates into the cavity 11 to form a microwave electromagnetic field. 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 because the discharge lamp 13 is located near the center of the spherical part 5. This reflected light and the direct light from the discharge lamp 13 are radiated outward through the metal mesh plate 7. The light radiated outward is collected by a condensing lens 18.
The light is focused on the required 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 portion 8 need to be processed 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 in order to eliminate the drawbacks of the conventional ones as described above, and involves processing a curved surface having spring properties so that the contact part of the metal mesh plate with the flange part protrudes toward the flange part. Therefore, it is an object of the present invention to provide a microwave discharge light source device that does not require flat finishing of the flange portion and does not leak microwaves even with a small number of holding screws.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 3, the contact portion 7a of the metal mesh plate 7 is machined with a curved surface having spring properties so as to protrude toward the flange portion 10, and this curved surface is a stepped curved surface 7b in this example. . That is,
Since the stepped curved surface has a spring action, the flange portion 10
Even if the contact surface 10a of the presser flange 8 and the contact surface 8a of the presser flange 8 are rough, when the presser flange 8 is tightened to the flange portion 10 with the presser screw 9, for example, the contact surface 8a of the presser flange 8 and the flange portion 10
The stepped curved surface 7b of the metal mesh plate 7 is crushed and deformed in the convex portion with the contact surface 10a, while the concave portion is not crushed, so that the contact surface 7a of the metal mesh plate 7 is in electrical contact with the contact surface 10a of the flange portion 10 completely over the entire circumference. As a result, both contact surfaces 7a, 1
Since there is no gap between the contact surfaces 0a, the microwaves inside the microwave cavity 11 will not cause discharge between the contact surfaces, and the microwaves will not leak to the outside. Furthermore, the number of retaining screws 9 can be reduced over the entire circumference. For example, the diameter of microwave cavity 11 is 130 mm.
In this case, only three push screws are required.

FIG. 4 shows another embodiment of the contact surface 7a of the metal mesh plate 7. In this example, a convex surface 7 having spring properties is formed over the entire circumference of the contact surface of the metal mesh plate 7.
c is formed. In this case as well, the contact surface 7a of the metal mesh plate and the flange portion 1
Contact with the contact surface 10a of 0 is made 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 circumference. This clip 30 has a hook 31 attached to the outside of one flange portion 10, and a hook 33 on the other presser flange 8 to which a band 32 of the hook 31 is hooked. Even if the clip 30 is used in this way, the presser flange 8 cannot be tightened to the flange portion 10 and the contact surface 7 of the metal mesh plate
Since the contact surface 10a of the flange portion 10 can be brought into good contact with the contact surface 10a of the flange portion 10, the metal mesh plate can be easily attached and detached in place of the retaining screw 9. In addition, the fifth
Although the figure shows an example in which the curved surface of the metal mesh plate 7 is a stepped curved surface 7b, it may be a convex surface 7c.

As described above, according to the present invention, there is provided a cavity wall having an opening on at least one side and a flange provided around the opening, and a metal mesh plate overlaid on the flange so as to close the opening. In a microwave discharge light source device equipped with a microwave cavity mounted with a holding metal fitting and an electrodeless discharge lamp inside this cavity, the contact surface of the metal mesh plate with the flange part is made to protrude toward the flange part side. By processing the curved surface with spring properties, the contact between the metal mesh plate and the flange part of the microwave cavity wall is perfect, which eliminates the need for precision on both contact surfaces of the metal mesh plate and the flange part, and Even simple tightening means can be effective in preventing electrical discharge and microwave 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 metal mesh plate installed, 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, 7a...
...Contact surface, 7b...Stepped curved surface, 7c...Convex surface, 8
... Presser flange, 9 ... Holder screw, 10 ... Flange section, 11 ... Microwave cavity, 13 ... Electrodeless discharge lamp, 30 ... Clip. 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, and a metal mesh plate overlaid on the flange so as to close the opening. In a microwave discharge light source device comprising a microwave cavity mounted using a holding fitting and a fastening means, and an electrodeless discharge lamp inside this cavity, the corresponding surface of the metal mesh plate to the flange part is attached to the flange. A microwave discharge light source device characterized in that a curved surface having spring properties is processed so as to protrude toward the side. 2. The microwave discharge light source device according to claim 1, wherein the contact portion of the metal mesh plate is a stepped curved surface. 3. The microwave discharge light source device according to claim 1, wherein the contact portion of the metal mesh plate has a convex curved surface.