JP2000348889A - High frequency energy supply device and high frequency electrodeless discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress corona discharge generating at the tip of a conductive projection part by suppressing generation of abnormal discharge in the vicinity of at least one tip of plural conductive projection parts contained in a side cavity resonator group. SOLUTION: A suppressing means for suppressing generation of abnormal discharge is installed in the vicinity of at least one tip of plural conductive projection parts contained in a side cavity resonator group. As the suppressing means, the corner of a tip 21 of a vane 14 is rounded or chamfered to reduce an inequality electric field at the tip of the vane 14. The tip of the conductive projection part may be evacuated or pressed, and by this, generation of abnormal discharge in the vicinity of the tip of the conductive projection part can be suppressed or prevented. Moreover, the tip of the vane may be covered with a dielectric, and by this, break down voltage in a gap at the tip of the vane is increased, and unnecessary corona discharge can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency energy supply device and a high-frequency electrodeless discharge device using the same.

[0002]

2. Description of the Related Art A high frequency electrodeless discharge lamp is easier to couple electromagnetic energy to a filler than an electrode arc discharge lamp, and can eliminate mercury from the filler for discharge luminescence. There is an excellent advantage that high luminous efficiency can be expected because there is no loss. Further, since no electrodes are provided inside the discharge space, blackening of the bulb inner wall due to electrode evaporation does not occur. This makes it possible to greatly extend the lamp life. From these characteristics, high-frequency electrodeless discharge lamps are the next generation of high-intensity discharge lamps.
Research has been actively conducted in recent years.

[0003] Generally, in a discharge lamp device, the smaller the light source, the closer to a point light source, and the light distribution design can be more idealized. For example, in consideration of application to a standard liquid crystal video projector or the like, a plasma arc size of about 3 mm or less is required from the viewpoint of optical design for improving the utilization efficiency of radiation light. On the other hand, in the electrodeless discharge lamp, the size of the plasma arc is determined by the inner diameter of the bulb. However, in the conventional high frequency electrodeless discharge lamp device using a cavity resonator, the size of the plasma can be reduced depending on the wavelength. Due to the limitations, it is not suitable for applications requiring a high-brightness point light source. Therefore, a high-frequency energy supply device capable of concentrating a high-frequency resonance electromagnetic field in a space smaller than the cavity resonator has been developed in recent years.

A conventional high-frequency energy supply device 120 described in Japanese Patent Application Laid-Open No. 10-189270 will be described below.
Will be described.

[0005] The high-frequency energy supply device 120 includes a plurality of side cavity resonators (that is, a group of side cavity resonators).
The side cavity resonator group has an electromagnetic inductive function section made of a ring-shaped conductive material and an electric capacity function section made of an air gap. The side cavity resonator group is arranged in an annular shape such that the capacitive function units face each other inside the group. The side cavity resonator group supplies high-frequency energy required for discharge to a load using a resonance high-frequency electromagnetic field generated at the center of the side cavity resonator group. Thereby, the high-frequency resonance electromagnetic field can be concentrated in a space smaller than the conventional cavity resonator. As a result, high-frequency energy can be supplied to a space smaller than that of the conventional cavity resonator.

FIG. 12 shows a structure of a vane type resonator 122 as an example of a side cavity resonator group of a conventional high frequency energy supply device 120. The vane-type resonator 122 includes the cylinder 1
25, and eight plate-like vanes 124 extending from the inner periphery of the cylinder 125 toward the center of the cylinder 125.
The cylinder 125 and the vane 124 are made of a conductive material.

[0007] The surface on which the inner peripheral surface of the cylinder 125 and the two adjacent vanes 124 oppose each other and the space defined by these surfaces serve as an electromagnetic inductive function part. Two vanes 124 adjacent to each other and a gap between them function as an electric capacitive function portion.

High-frequency energy transmitted from a high-frequency oscillator (not shown) passes through a coupling antenna 133 serving as an electric-field-coupling-type high-frequency coupling unit 123 and the vein resonator 12
2 The coupling antenna 133 is electrically connected to one of the eight vanes 124 by caulking or welding. The vane resonator 122 is designed in advance so as to resonate at the frequency of the high-frequency energy to be coupled. In this way, using the resonance high-frequency electric field E generated at the center of the vane-type resonator 122,
The required high-frequency energy is supplied to a load 121 such as an electrodeless discharge lamp disposed at the center of the vane type resonator 122.

Here, the number of side cavity resonators included in the vane-type resonator 122 is N, and
Is designed to be driven in a mode in which the phases of the adjacent side cavity resonators are shifted by 2π / N. In this case, the electric charge of a certain vane 124 and the electric charge of the opposing vane 124 have opposite polarities. The resonance high-frequency electric field E generated by these electric charges is directed in the diameter direction of the central portion of the vane-type resonator 122, and has a distribution crossing a load 121 such as an electrodeless discharge lamp. When operating the vane-type resonator 122 in the 2π / N mode, the strongest electric field can be obtained at the center where the load 121 such as an electrodeless discharge lamp is disposed.

FIG. 13 shows the structure of a conventional high-frequency electrodeless discharge lamp device 130 having a group of side cavity resonators 132. The side cavity resonator group 132 is, for example, the vane-type resonator 122 shown in FIG.

The electrodeless discharge lamp 131 is made of a spherical quartz glass filled with an ionizable medium which emits light by high frequency discharge. The electrodeless discharge lamp 131 is supported at the center of the side cavity resonator group 132 by a support rod made of quartz glass.

Reference numeral 139 indicates a high-frequency waveguide made of a metal conductor, and reference numeral 137 indicates a magnetron for exciting high frequency. An oscillation antenna 138 is provided inside the high-frequency waveguide 139. The dimensions of each part of the side cavity resonator group 132 are designed so that the resonance frequency of the side cavity resonator group 132 matches the frequency of the high frequency oscillated from the oscillation antenna 138.

When a high voltage is applied to the magnetron 137 from a high-voltage power supply, a high frequency is excited inside the high-frequency waveguide 139, and the propagated high frequency is transmitted to the coupling antenna 133.
Is coupled to the side cavity group 132. The coupling antenna 133 is a coupling antenna support 13 made of a dielectric.
6 locks it in place.

The electrodeless discharge lamp 131 discharges and emits light due to the resonant high-frequency electromagnetic field generated at the center of the side cavity resonator group 132. The radiation emitted by the discharge is reflected by the reflector 134 made of a conductor, and is extracted to the outside through the metal net 135. The reflecting mirror 134 and the metal net 135 function as high-frequency leakage prevention means.

According to the high-frequency energy supply device described in Japanese Patent Application Laid-Open No. Hei 10-189270, it is possible to maintain a plasma arc having a relatively small size of 10 mm or less even in a high-frequency electrodeless discharge.

[0016]

According to the conventional high-frequency energy supply device 120 described above, the inventors of the present invention can supply energy with good matching to a load such as an electrodeless discharge lamp due to a strongly concentrated resonance electric field. If this is not possible, the side cavity resonator group (for example, the vane type resonator 122)
It has been found that arcing by corona discharge occurs from the tip of the conductive protrusion (for example, the vane 124) to the atmosphere in the side cavity resonator group. For example, reference numeral 126 shown in FIG. 12 schematically shows that arcing due to corona discharge occurs at the tip of the vane 124.

When such a corona discharge occurs, a large amount of high-frequency energy is lost there, and there is a problem that sufficient high-frequency energy cannot be supplied to the load. Also, when the atmosphere in the side cavity resonator group causes strong corona discharge for a long time, the glass of the electrodeless discharge lamp,
There is also a problem that the high frequency shield or the side cavity resonator group itself may be melted and broken.

Japanese Patent Application Laid-Open No. Hei 10-189270 does not mention the occurrence of arcing due to corona discharge or the problem described above.

The present invention provides a high-frequency energy supply device capable of suppressing the occurrence of corona discharge from the tip of the conductive protrusion of the side cavity resonator group, and a high-frequency electrodeless discharge device using the same. The purpose is to:

[0020]

According to the present invention, there is provided a high-frequency energy supply device comprising: a side cavity group having a plurality of conductive protrusions; and an abnormal state near at least one end of the plurality of conductive protrusions. And a suppressing means for suppressing generation of electric discharge, whereby the above object is achieved.

[0021] At least one end of the plurality of conductive protrusions may be rounded or chamfered.

[0022] The pressure of the atmosphere around at least one end of the plurality of conductive protrusions may be set to a pressure at which abnormal discharge is unlikely to occur as compared with atmospheric pressure.

[0023] The high-frequency energy supply device may further include a dielectric covering at least one end of the plurality of conductive protrusions, wherein the dielectric has a breakdown strength greater than that of the atmosphere. You may have.

The side cavity resonator group may be a vane type resonator.

The high-frequency electrodeless discharge device of the present invention comprises an electrodeless discharge generator and a high-frequency energy supply device for supplying high-frequency energy to the electrodeless discharge generator. A side cavity group having a conductive protruding portion, and a suppressor that suppresses the occurrence of abnormal discharge in the vicinity of at least one end portion of the plurality of conductive protruding portions.
The above object is achieved.

[0026] The suppressing means may include an assisting means for assisting a reliable start of the discharge in the electrodeless discharge generating section.

According to another aspect of the present invention, there is provided an electrodeless discharge generator, a high-frequency energy supply device for supplying high-frequency energy to the electrodeless discharge generator, and a reliable discharge in the electrodeless discharge generator. And assist means for assisting the vehicle to start.
The above object is achieved.

[0028] The assist means may include a support member that supports the electrodeless discharge generating section and includes a starting auxiliary electrode, and a starting circuit that applies a high voltage pulse to the starting auxiliary electrode.

[0029] The assisting means supports the electrodeless discharge generating section and encloses a rare gas, a high voltage application electrode connected to the support member, and applies a high voltage pulse to the high voltage application electrode. A starting circuit for generating a rare gas discharge inside the support member by applying the voltage may be included.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

The term "high frequency" in this specification refers to an electromagnetic wave having a frequency of 1 MHz to 100 GHz.
In particular, in the "microwave" frequency range of 300 MHz to 30 GHz, the present invention can obtain suitable effects.

(Embodiment 1) FIG. 1 shows the configuration of a high-frequency energy supply device 10 according to Embodiment 1 of the present invention.

The high-frequency energy supply device 10 includes a vane type resonator 12 as a group of side cavity resonators.

The vane-type resonator 12 has a cylinder 15 and eight plate-shaped vanes 14 extending from the inner periphery of the cylinder 15 toward the center of the cylinder 15. The cylinder 15 and the vane 14 are made of a conductive material. The inner radius of the cylinder 15 is
For example, it is 20 mm. The plate thickness of the vane 14 is, for example, 2.5 mm. The vanes 14 are also called conductive protrusions.

A pair of adjacent vanes 14 and a gap between the pair of adjacent vanes 14 form one side cavity resonator. A substantially annular coupling of the plurality of side cavity resonators forms a vane-type resonator 12. It is sufficient that the plurality of side cavity resonators are electrically coupled, and it is not always required that the plurality of side cavity resonators are physically integrated. FIG. 1 shows an example of a vane-type resonator 12 in which eight side cavity resonators (a group of side cavity resonators) are integrally formed.

High-frequency energy transmitted from a high-frequency oscillator (not shown) is coupled to the vane-type resonator 12 via the coupling antenna 13. The coupling antenna 13 is electrically connected to one of the eight vanes 14 by caulking or welding. Note that the vane-type resonator 12 is
It is pre-designed to resonate at the frequency of the coupled high frequency energy. In this manner, the high-frequency energy required for the load 11 such as the electrodeless discharge lamp disposed at the center of the vane-type resonator 12 is obtained by using the resonance high-frequency electric field E generated at the center of the vane-type resonator 12. Supplied. Here, the inner diameter of the cylindrical space in which the load 11 is to be provided is, for example, 10 mm.

In the vane resonator 12, the vane 14
Are rounded at the end closer to the center of the cylinder 15 (hereinafter referred to as the tip 21 of the vane 14).
For example, the corner of the tip 21 of the vane 14 can be rounded by performing a rounding process on the tip 21 of the vane 14.

FIG. 2 shows the tip 21 of the vane 14 in an enlarged manner. Thus, by rounding the corner of the tip 21 of the vane 14, it is possible to avoid a strong electric field from being concentrated on a part of the tip 21 of the vane 14. As a result, it is possible to suppress or prevent the occurrence of abnormal discharge (for example, corona discharge) near the tip 21 of the vane 14.

Here, the corona discharge generally means the following phenomenon. In the case of a flat counter electrode, a uniform electric field is formed between the electrodes except near the edges. However, considering the needle and the flat counter electrode, a significant unequal electric field is produced. When the unequal electric field is remarkable, ionization occurs only in a strong electric field, and does not ionize in other weak electric fields, and a partial discharge (local destruction) occurs. This discharge is called corona discharge.

In the vane-type resonator 12, the strongest electric field is generated in the gap between the adjacent vanes 14.

FIG. 3 shows a result of analyzing the electric field intensity distribution in the surrounding atmosphere at the tip of the vane 124 of the conventional vane-type resonator 122 described with reference to FIG. 12 by using the finite element method. In FIG. 3, the curve shows the contour line of the electric field intensity in the 2π / N mode.

In the conventional vane resonator 122, the tip of the vane 124 has a sharp corner. As shown in FIG. 3, the contour lines of the electric field intensity are extremely dense in the portion where the corner of the tip of the vane 124 is sharp. This is because the electric field strongly concentrates on the pointed corner of the vane 124.

FIG. 4 shows a vane type resonator 12 according to the present invention.
4 shows the result of analyzing the electric field strength distribution in the atmosphere around the tip 21 of the vane 14 using the finite element method. In FIG. 4, the curve shows the contour line of the electric field intensity in the 2π / N mode.

In the vane type resonator 12, the vane 1
4 have rounded corners. As shown in FIG. 4, as compared with the case of FIG.
Are sparse in the vicinity of. This is Bain 14
This is because the electric field is dispersed in the vicinity of the tip portion 21 of FIG. Thereby, the unequal electric field at the tip 21 of the vane 14 can be reduced. As a result, it is possible to suppress or prevent the occurrence of corona discharge.

It is not necessary to round the corners of the tips 21 of all the vanes 14 among the plurality of vanes 14 included in the vane-type resonator 12. It is within the scope of the present invention to round the corner of the tip 21 of at least one of the vanes 14 included in the vane resonator 12.
For example, the vane 14 to which the coupling antenna 13 is coupled
May be rounded, or the corners of the tips 21 of some vanes 14 arranged near the vane 14 to which the coupling antenna 13 is coupled may be rounded.

FIGS. 1 and 2 show an example in which the corner of the tip end 21 of the vane 14 is rounded in the horizontal direction (horizontal direction) as shown by an arrow Rh in FIG. But,
The direction and location of rounding the corner of the vane 14 are not limited thereto.

FIG. 5 is a sectional view of the vane 14 shown in FIG.
A section is shown. For example, the corner of the tip 21 of the vane 14 may be rounded in the vertical direction (vertical direction) as shown by an arrow Rv in FIG. Reference numeral 51 indicates a portion of the vane 14 whose corner is rounded in the vertical direction. It is also desirable to round the upper corner and the lower corner of the portion other than the tip portion 21 of the vane 14. Reference numeral 52 indicates the portion of the vane 14 with the upper and lower corners rounded. By rounding the corners of these parts,
The electric field can be prevented from being concentrated on the pointed portion of. As a result, the occurrence of corona discharge can be suppressed or prevented.

In the first embodiment, a case where the radius of curvature of the rounded corner of the tip end portion 21 of the vane 14 is equal to half of the maximum thickness of the vane 14 is shown. It is not limited. However, as the radius of curvature of the rounded corners decreases, the electric field concentrates, and corona discharge easily occurs. On the other hand, the required radius of curvature changes depending on various conditions such as the strength of the applied high-frequency electric field and the distance between the adjacent vanes 14.

Therefore, it is desirable to determine an appropriate value of the radius of curvature of the rounded corner based on the experimental results so as to conform to the conditions such as the size of the side cavity resonator group to be applied and the high frequency power. The inventors believe that the thickness of the vanes 14 is about 1 mm, the gap between adjacent vanes 14 is about 5 mm, and the input power is about 30 mm.
The experiment was performed under the condition of W. In this experiment, a sufficiently useful result could be obtained when the radius of curvature of the rounded corner was about 0.2 mm or more.

Further, instead of rounding the corner of the tip 21 of the vane 14, the same effect can be obtained by chamfering the corner of the tip 21 of the vane 14 as shown in FIG. Alternatively, the tip 21 of the vane 14
In addition to rounding one corner, another corner of the tip 21 of the vane 14 may be chamfered. In this manner, by rounding or chamfering the tip 21 of the vane 14, it is possible to prevent the electric field from being concentrated on the sharp portion of the vane 14. As a result, the occurrence of corona discharge can be suppressed or prevented.

(Embodiment 2) FIG. 7 shows a configuration of a high-frequency energy supply device 70 according to Embodiment 2 of the present invention.

The high-frequency energy supply device 70 includes a group of side cavity resonators 72. The structure of the side cavity resonator group 72 is the same as, for example, the structure of the conventional vane-type resonator 122 shown in FIG.

The electrodeless discharge lamp 71 is supported at the center of the side cavity resonator group 72 by a support rod. High-frequency waves transmitted from a high-frequency oscillator (not shown) such as a magnetron are coupled to the side cavity resonator group 72 by the coupling antenna 77. The coupling antenna 77 is fixed at an appropriate position by a coupling antenna support 76 made of a dielectric.

The electrodeless discharge lamp 71 emits and emits light due to the resonant high-frequency electromagnetic field generated at the center of the side cavity resonator group 72. The radiation emitted by the discharge is reflected by a reflecting mirror 74 made of a conductor, and is extracted outside through a metal net 73 and an airtight lid 75 made of a light-transmitting material. The reflecting mirror 74 and the metal net 73 function as high-frequency leakage prevention means.

The hermetic lid 75 is made of a heat-resistant and translucent material such as borosilicate glass. The airtight lid 75, the reflecting mirror 74, and the coupling antenna support 76 form an airtight structure. By making the inside of this airtight structure vacuum or pressurized,
The tip of the conductive protrusion at which the strongest electric field occurs in the side cavity group 72 is also vacuum or pressurized. Thereby, generation of abnormal discharge (for example, corona discharge) in the vicinity of the tip of the conductive protrusion can be suppressed or prevented.

Hereinafter, with reference to FIG. 8, the reason why abnormal discharge can be suppressed by setting the atmosphere around the end of the conductive protrusion of the side cavity resonator group 72 to be vacuum or pressurized will be described. explain.

FIG. 8 is a correlation diagram between the breakdown voltage at which a spark discharge occurs, the pressure of the surrounding atmosphere, and the distance between the electrodes when a DC pulse voltage is applied between the parallel plate electrodes.

In FIG. 8, the horizontal axis represents the product of the pressure p of the surrounding atmosphere and the distance l between the electrodes, and the vertical axis represents the breakdown voltage Vs at which spark discharge occurs.

As the product p · l of the pressure p of the surrounding atmosphere and the distance l between the electrodes becomes smaller, the breakdown voltage Vs gradually decreases, but when the product p · l becomes smaller than 1, the breakdown voltage becomes smaller. Vs rises sharply. Therefore, the product p
It can be seen that corona discharge is extremely unlikely to occur when the surrounding atmosphere is evacuated so that 1 is sufficiently smaller than 1 (cm · Torr). In a range where the product p · l is sufficiently larger than 1 (cm · Torr), the breakdown voltage Vs gradually increases as the product p · l increases. Therefore, the product p · l is 1 (cm · Torr)
By pressurizing the surrounding atmosphere so as to be sufficiently larger than that, the occurrence of corona discharge can be suppressed.

In the vane type resonator, the distance of the gap at the tip of the vane having the strongest electric field is generally 0.1 to 1c.
m. Therefore, when the surrounding atmosphere is evacuated, it is understood that the pressure in the airtight structure should be set to a value sufficiently smaller than 1 Torr. For example, when air is exhausted using a rotary pump, the pressure becomes 10
^-2 to 10 ^-3 Torr. This can be said to be a value sufficient to suppress discharge.

Since the atmospheric pressure is about 760 Torr, when the pressure p of the surrounding atmosphere is equal to the atmospheric pressure, the product pl is obviously larger than 1. Accordingly, the breakdown voltage Vs is increased by pressurizing the surrounding atmosphere so that the pressure p of the surrounding atmosphere becomes higher than the atmospheric pressure. Thereby, the occurrence of corona discharge can be suppressed.

As described above, by setting the pressure of the atmosphere around at least one end of the plurality of conductive protrusions of the side cavity resonator group 72 to a pressure at which abnormal discharge does not easily occur as compared with atmospheric pressure. It is possible to suppress or prevent the occurrence of abnormal discharge.

In the above description, a configuration in which the entire inside of a vane-type resonator, which is a kind of the side cavity resonator group, is vacuumed or pressurized has been described. Typically, the same effect can be obtained even in a configuration in which only the portion around the gap between the tips of the conductive protrusions is vacuumed or pressurized.

(Embodiment 3) FIG. 9A shows a third embodiment of the present invention.
1 shows a configuration of a high-frequency energy supply device 90 according to the embodiment.

The high-frequency energy supply device 90 includes a vane-type resonator 92 as a side cavity resonator group.

An electrodeless discharge lamp 91 is provided at the center of the vane type resonator 92. High-frequency energy propagated from a high-frequency oscillator (not shown) is coupled to the vane-type resonator 92 via a coupling antenna (not shown). The vane resonator 92 is designed in advance to resonate at the frequency of the high-frequency energy to be coupled. As a result, a resonant high-frequency electric field is generated at the center of the vane-type resonator 92. The energy required for the high-frequency discharge is supplied to the electrodeless discharge lamp 91 using the resonance high-frequency electric field generated at the center of the vane-type resonator 92.

Further, as shown in FIG. 9A, the tip of the vane where the highest electric field occurs in the vane-type resonator 92 is covered with a dielectric 93. Thus, the breakdown voltage of the gap at the tip of the vane increases, and unnecessary corona discharge is suppressed.

FIG. 9B shows a BB section shown in FIG. 9A. As shown in FIG. 9B, the dielectric 93 preferably covers not only the gap between the adjacent vanes but also the upper and lower sides of the vanes. This is useful to prevent corona discharge from occurring from either the upper or lower corner of the vane.

Table 1 shows the dielectric breakdown strength of the atmosphere and the dielectric breakdown strength of typical dielectric materials having excellent insulation properties.

[0070]

[Table 1]

As is clear from Table 1, by covering the tip of the vane with a dielectric 93 made of a material having a dielectric breakdown strength higher than the atmospheric dielectric strength, the voltage at which the dielectric breakdown occurs can be reduced. It can be increased 3 to 24 times compared to the atmosphere. Thereby, generation of unnecessary corona discharge in the side cavity resonator group can be suppressed.

The dielectric 93 is not limited to a solid. The dielectric 93 may be a liquid or a gas as long as it satisfies the condition of having a breakdown strength greater than the breakdown strength of the atmosphere.

In consideration of application to a high-frequency electrodeless discharge lamp device, it is preferable to select a material having a high regular transmittance as the material of the dielectric 93. This is because such material selection can reduce light loss and increase light use efficiency. Therefore, as a material of the dielectric 93,
It is desirable to select a material such as quartz glass or borosilicate glass. Needless to say, a material having a small dielectric loss should be selected as the material of the dielectric 93.

In the third embodiment, the dielectric 93 covers the tip of the vane and fills the gap between the tips of the vanes. However, the arrangement of the dielectric 93 is not limited to this. . For example, the dielectric 93 may be arranged so that the dielectric 93 covers the entire conductive protrusion of the vein resonator 92.

Alternatively, only the surface of the tip of the vane may be covered with the dielectric 93. In this case, emission of electrons from the surface of the tip of the vane is suppressed.
As a result, the occurrence of corona discharge is suppressed.

In the above-described first to third embodiments, examples have been described in which a vane-type resonator is used as the side cavity resonator group, but the present invention is not limited to this. It is also possible to use another type of side cavity resonator group such as a hole-slot type resonator as the side cavity resonator group.

Further, in the above-described first to third embodiments, the load to which high-frequency energy is supplied is not limited to a discharge lamp. For example, the load is an electrodeless discharge generator. Alternatively, the load may be a discharge gas. The application field of the high-frequency energy supply device of the present invention is not limited to discharge lamps (particularly, high-frequency electrodeless discharge lamps). For example, in an apparatus using a high-frequency discharge such as a plasma CVD, a plasma torch, or a gas discharge laser, supply of energy by a concentrated and non-deflected resonance high-frequency electric field to form a stable discharge plasma having a relatively small diameter. Is required, the high-frequency energy supply device of the present invention is useful.

In addition, the high-frequency energy heats, emits, melts, or evaporates a relatively small-diameter object (load) disposed at the center of the high-frequency energy supply device. The high-frequency energy supply device of the present invention is also useful when it is necessary to supply discharge energy by a high resonance high-frequency electric field.

(Embodiment 4) When the side cavity resonator group is used as a high-frequency energy supply device for supplying high-frequency energy to an electrodeless discharge generator (for example, an electrodeless discharge lamp), the electrodeless discharge generator Before the discharge occurs, there is no place for high-frequency energy. This contributes to abnormal discharge.

On the other hand, the electrodeless discharge lamp does not show conductivity before starting discharge, but shows conductivity after starting discharge due to the plasma inside the electrodeless discharge lamp. Therefore, before and after the discharge start of the electrodeless discharge lamp, the impedance seen from outside the resonator as the high-frequency energy supply device changes greatly. Therefore, if the dimensions of the resonator and the device are designed to match the impedance at the time of sustaining discharge, the dimensions do not match the impedance before the start of discharge, so the resonance electric field at the center of the resonator is weak, and the electrodeless discharge lamp There is a problem that the starting of the vehicle is uncertain.

By providing an assisting means for assisting the discharge to be reliably started in the electrodeless discharge generating section, the probability that high-frequency energy causes abnormal discharge can be reduced. As a result, occurrence of abnormal discharge can be suppressed.

Hereinafter, in the fourth and fifth embodiments, specific examples of the above-described assist means will be described.

FIG. 10 shows a side cross section of a high-frequency electrodeless discharge lamp device 100 according to Embodiment 4 of the present invention. The high-frequency electrodeless discharge lamp device 100 includes an electrodeless discharge lamp 101.
A side cavity resonator group 102 is included as a high-frequency energy supply device for supplying high-frequency energy to the power supply.

The structure of the side cavity resonator group 102 is, for example,
The structure is the same as that of the conventional vane-type resonator 122 shown in FIG. Alternatively, the structure of the side cavity resonator group 102 may be the same as the structure of the side cavity resonator group (or the vane type resonator) described in the first to third embodiments.

The electrodeless discharge lamp 101 is made of a translucent heat-resistant material such as quartz glass. Electrodeless discharge lamp 101
Is filled with a rare gas and a luminescent material such as a metal halide. The electrodeless discharge lamp 101 is supported at the center of the side cavity resonator group 102 by a support rod 106. The support bar 106 is also made of quartz glass or the like.

A light reflecting surface is formed inside the annular portion 103 of the side cavity resonator group 102, and the annular portion 103 also serves as a reflecting mirror. Further, the annular portion 103 and the metal net 104
Function as high-frequency leakage prevention means for preventing high-frequency leakage. The annular portion 103 is made of a conductive material, and the metal net 104 is made of a light-transmitting conductive material. The radiated light generated by the discharge of the luminescent material sealed inside the electrodeless discharge lamp 101 is reflected by the reflecting mirror 103.
And is extracted outside through the metal net 104.

As described above, the electrodeless discharge lamp 101 is
Functions as an electrodeless discharge generator.

The support rod 106 is hollow. Support rod 106
Of the starting auxiliary electrode 108 made of a rod-shaped metal conductor
Is installed. A lead from a starting circuit 109 is electrically connected to the starting auxiliary electrode 108. The high voltage pulse generated by the starting circuit 108 is applied to the starting auxiliary electrode 108 via a conductor.

The starting auxiliary electrode 108 and the reflecting mirror 103
A dielectric support bar 106 is inserted between the two.
Thus, the starting auxiliary electrode 108 and the reflecting mirror 103 are electrically insulated.

High-frequency energy generated from a high-frequency power supply 107 as a high-frequency oscillator propagates through a high-frequency propagation section 105 such as a coaxial line and is coupled to the side cavity resonator group 102. As a result, a resonant high-frequency electric field is generated at the center of the side cavity resonator group 102 where the electrodeless discharge lamp 101 is installed.

However, in particular, the electrodeless discharge lamp 10
In a situation where 1 is sufficiently cooled, since the electron density inside the electrodeless discharge lamp 101 is low, a starting discharge due to dielectric breakdown may not be caused by the resonance high-frequency electric field alone.

Therefore, the starting circuit 1 is connected to the starting auxiliary electrode 108.
By applying a high voltage pulse from 09, a minute discharge is generated inside the electrodeless discharge lamp. Thereby, the electrodeless discharge by the high frequency is reliably started. In an experiment conducted by using a high-voltage pulse transformer used for starting a general high-intensity discharge lamp, by applying a high voltage of about 20 kV to the starting auxiliary electrode 108, electrodeless discharge by high frequency was reliably performed. I was able to confirm that it would start.

It is not necessary to apply a high-voltage pulse to the starting auxiliary electrode 108 after the high-frequency electrodeless discharge has started. Therefore, it is desirable to stop applying the high-voltage pulse immediately after the high-frequency electrodeless discharge starts.

If the starting auxiliary electrode 108 is too close to the electrodeless discharge lamp 101, it is heated by the resonance electric field at the center of the side cavity resonator group 102, causing not only loss of high frequency energy but also high frequency energy. If the electric power is large, the starting auxiliary electrode 108 itself may be melted and damaged.

In the experiment conducted by the inventors, it was found that even when the distance between the tip of the starting auxiliary electrode 108 and the tube wall of the electrodeless discharge lamp 101 was 10 mm or more, the electrodeless discharge by high frequency was sufficiently started. Was completed. This distance is
Since an appropriate value greatly changes depending on the supplied high-frequency energy power, the applied high-voltage pulse for starting, and the like, it cannot be uniquely determined. However, if the tip of the starting auxiliary electrode 108, which is a conductor, is too close to the center of the side cavity resonator group 102, a current due to a resonance electric field flows through the starting auxiliary electrode 108, causing power loss. From that viewpoint, the starting auxiliary electrode 10
It is desirable that the tip of 8 be located as far away from the center of the side cavity group 102 as possible. Therefore, based on the experimental results, to meet the specifications of the applied device,
It is desirable to appropriately determine the distance between the tip of the starting auxiliary electrode 108 and the tube wall of the electrodeless discharge lamp 101.

With the above configuration, the electrodeless discharge lamp 10
1 reliably starts the high-frequency discharge, and thereafter receives the supply of high-frequency energy from the side cavity resonator group 102 to maintain the discharge. According to the high-frequency electrodeless discharge lamp device 100 configured as described above, high-frequency discharge in the electrodeless discharge lamp can be reliably started.

(Embodiment 5) FIG. 11 is a side sectional view of a high-frequency electrodeless discharge lamp device 110 according to Embodiment 5 of the present invention. The high-frequency electrodeless discharge lamp device 110 includes a side cavity resonator group 112 as a high-frequency energy supply device that supplies high-frequency energy to the electrodeless discharge lamp 111.

The structure of the side cavity resonator group 112 is, for example, as follows.
The structure is the same as that of the conventional vane-type resonator 122 shown in FIG. Alternatively, the structure of the side cavity resonator group 112 may be the same as the structure of the side cavity resonator group (or the vane type resonator) described in the first to third embodiments.

The electrodeless discharge lamp 111 is similar to that of the fourth embodiment.
Similarly to the above, it is made of a translucent heat-resistant material such as quartz glass.
A rare gas and a luminescent material such as a metal halide are sealed inside the electrodeless discharge lamp 111. The electrodeless discharge lamp 111 is supported by the support rod 116 at the center of the side cavity resonator group 112. The support bar 116 is also made of quartz glass or the like.

As in the fourth embodiment, side cavity group 1
A light reflecting surface is formed inside the 12 annular portions 113, and the annular portions 113 also serve as reflecting mirrors. Further, the annular portion 113 and the metal net 114 function as high-frequency leakage prevention means for preventing high-frequency leakage. The annular portion 113 is made of a conductive material, and the metal net 114 is made of a light-transmitting conductive material. The radiated light generated by the discharge of the luminescent material sealed inside the electrodeless discharge lamp 111 is reflected by the reflecting mirror 113 and is reflected by the metal net 11.
4 to the outside.

As described above, the electrodeless discharge lamp 111 is
Functions as an electrodeless discharge generator.

The support rod 116 is hollow. Support rod 116
Is filled with a rare gas such as argon. The support bar 116 has a portion that extends outside the annular portion 113. The high voltage application electrode 118 is provided in this portion. A conductor from the starting circuit 119 is electrically connected to the high voltage application electrode 118. The high voltage pulse generated by the starting circuit 119 is applied to the high voltage application electrode 118 via a conductive wire.

The high voltage application electrode 118 and the reflecting mirror 11
3 is arranged at a sufficient distance so that the surrounding atmosphere does not cause dielectric breakdown. Thus, the high voltage application electrode 118 and the reflecting mirror 113 are electrically insulated.

High-frequency energy generated from a high-frequency power supply 117 as a high-frequency oscillator propagates through a high-frequency propagation section 115 such as a coaxial line, and is coupled to the side cavity resonator group 112. As a result, a resonant high-frequency electric field is generated at the center of the side cavity resonator group 112 in which the electrodeless discharge lamp 111 is installed.

Therefore, by applying a high voltage pulse from the starting circuit 119 to the high voltage application electrode 118, a rare gas discharge is first generated inside the support rod 116. This allows
The plasma of the rare gas discharge functions as a conductor. Next, a high-voltage pulse propagates through the plasma of the rare gas discharge, and a starting discharge occurs inside the electrodeless discharge lamp 111.
In this way, electrodeless discharge by high frequency is reliably started.

It is not necessary to apply a high voltage pulse to the high voltage application electrode 118 after the high frequency electrodeless discharge has started. Therefore, it is desirable to stop applying the high-voltage pulse immediately after the high-frequency electrodeless discharge starts.

After stopping the application of the high voltage pulse,
The rare gas discharge inside the support bar 116 is extinguished. For this reason,
The high-frequency energy to be supplied to the electrodeless discharge lamp 111 is not consumed by the rare gas discharge inside the support rod 116.

With the above configuration, the electrodeless discharge lamp 11
1 can reliably start the high-frequency discharge, and thereafter can receive the high-frequency energy supplied from the side cavity resonator group 112 and maintain the discharge. According to the high-frequency electrodeless discharge lamp device 110 configured as described above, the electrodeless discharge lamp 1
11 can be started reliably.

As described above, in the fourth and fifth embodiments, high-frequency discharge in the electrodeless discharge lamp can be reliably started, and occurrence of abnormal discharge can be suppressed. .

[0110]

As described above, according to the high-frequency energy supply device of the present invention, an abnormal discharge (for example, corona discharge) is generated in the vicinity of at least one of the plurality of conductive protrusions. Is suppressed. This allows
Energy loss due to corona discharge in the atmosphere can be reduced. Further, a high-frequency energy supply device capable of efficiently supplying energy for discharge, heating, light emission, melting, or evaporation can be obtained. Further, it is possible to prevent the glass of the electrodeless discharge lamp, the high frequency shield, or the resonator itself from being melted and broken.

Further, according to the high-frequency electrodeless discharge device of the present invention, a remarkable effect of reliably starting the electrodeless discharge generator can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a high-frequency energy supply device 10 according to a first embodiment of the present invention.

FIG. 2 is an enlarged view showing a distal end portion 21 of a vane 14;

FIG. 3 is a diagram showing a result of analyzing the electric field intensity distribution in the surrounding atmosphere at the tip of a vane 124 of a conventional vane resonator 122 using a finite element method.

FIG. 4 shows a tip 21 of a vane 14 of the vane resonator 12.
FIG. 6 is a diagram showing a result of analyzing a field intensity distribution in a surrounding atmosphere of the marine environment using a finite element method.

FIG. 5 is a diagram showing a cross section AA of the vane 14 shown in FIG. 2;

FIG. 6 is an enlarged view showing a tip 21 of the vane 14;

FIG. 7 is a diagram illustrating a configuration of a high-frequency energy supply device 70 according to a second embodiment of the present invention.

FIG. 8 is a correlation diagram of a breakdown voltage with respect to a product of an atmospheric pressure and a distance between electrodes.

FIG. 9A is a diagram illustrating a configuration of a high-frequency energy supply device 90 according to a third embodiment of the present invention.

FIG. 9B is a diagram showing a BB cross section shown in FIG. 9A.

FIG. 10 is a side sectional view of a high-frequency electrodeless discharge lamp device 100 according to a fourth embodiment of the present invention.

FIG. 11 is a diagram showing a side cross section of a high-frequency electrodeless discharge lamp device 110 according to a fifth embodiment of the present invention.

FIG. 12 is a diagram showing a structure of a vane type resonator 122 as an example of a side cavity group of a conventional high frequency energy supply device 120.

FIG. 13 is a view showing the structure of a conventional high-frequency electrodeless discharge lamp device 130.

[Explanation of symbols]

 10, 70, 90 High frequency energy supply device 12 Bain resonator 13 Coupling antenna 14 Bain 15 Cylinder 21 Tip portion 100, 110 High frequency electrodeless discharge device 108 Starting auxiliary electrode 118 High voltage application electrode 109, 119 Starting circuit

Claims (10)

[Claims] 1. A group of side cavity resonators having a plurality of conductive protrusions, and suppression means for suppressing occurrence of abnormal discharge near at least one end of the plurality of conductive protrusions. High frequency energy supply device. 2. At least one of the plurality of conductive protrusions
The high-frequency energy supply device according to claim 1, wherein the two tip portions are rounded or chamfered. 3. At least one of the plurality of conductive protrusions
2. The high-frequency energy supply device according to claim 1, wherein the pressure of the atmosphere around the two tip portions is set to a pressure at which abnormal discharge does not easily occur as compared with the atmospheric pressure. 4. The high-frequency energy supply device further includes a dielectric covering at least one end of the plurality of conductive protrusions, wherein the dielectric has a breakdown strength greater than the atmospheric breakdown strength. The high-frequency energy supply device according to claim 1, wherein the high-frequency energy supply device has a height. 5. The high-frequency energy supply device according to claim 1, wherein the side cavity resonator group is a vane type resonator. 6. An electrodeless discharge generator, comprising: a high-frequency energy supply device for supplying high-frequency energy to the electrodeless discharge generation portion; wherein the high-frequency energy supply device has a side cavity resonance having a plurality of conductive protrusions. A high-frequency electrodeless discharge device, comprising: a group of devices; 7. The high-frequency electrodeless discharge device according to claim 6, wherein the suppression unit includes an assisting unit that assists in reliably starting the discharge in the electrodeless discharge generating section. 8. An electrodeless discharge generating section, a high-frequency energy supply device for supplying high-frequency energy to the electrodeless discharge generating section, and an assisting means for assisting a reliable start of discharge in the electrodeless discharge generating section. High frequency electrodeless discharge device equipped with. 9. The assisting device according to claim 8, wherein the assisting unit includes: a supporting member that supports the electrodeless discharge generating unit and includes a starting auxiliary electrode; and a starting circuit that applies a high voltage pulse to the starting auxiliary electrode. The high-frequency electrodeless discharge device according to claim 1. 10. The assisting means includes: a support member that supports the electrodeless discharge generating section and fills a rare gas; a high voltage application electrode connected to the support member; and a high voltage applied to the high voltage application electrode. The high-frequency electrodeless discharge device according to claim 8, further comprising: a starting circuit that generates a rare gas discharge inside the support member by applying a pulse.