JP2001338620A - Electrodeless discharge lamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp device which has a long life and high efficiency. SOLUTION: This electrodeless discharge lamp device is equipped with a microwave generating device 1 producing microwave energy, a microwave resonator 3 with hollow cylinder-shaped metal mesh part 3a having its top face and circumference face non-translucent with microwave and with visible light, a waveguide 2 for propagating microwave energy generated by the microwave generating device 1, a connecting slot 7 to connect microwave energy propagated through the wave guide with microwave resonator 3, a discharge bulb 5 made of material having translucency, enclosing discharge gas inside and set around the center of the microwave resonator 3, and a pair of metal stubs 4, 4 each electrically connected to the microwave resonator 3 and arranged on the same line passing the discharge bulb 5 with the discharge bulb 5 in between.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless discharge lamp lighting device.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 59-86153, an electrodeless method for resonating microwave energy using a cavity resonator and lighting a discharge bulb disposed inside the cavity resonator. A discharge lamp lighting device is provided. This electrodeless discharge lamp lighting device includes an oscillator such as a magnetron that generates microwave energy, a metal cavity resonator that resonates microwave energy,
A coupling slot for coupling the microwave energy propagated from the oscillator through the waveguide etc. to the cavity resonator, and a discharge gas such as a rare gas or metal is sealed inside formed from a transparent material such as quartz glass And a discharge bulb disposed inside the cavity resonator.
Here, when the microwave energy generated by the oscillator is propagated through a waveguide or the like and introduced into the cavity through a coupling slot, a standing wave is generated inside the cavity at a preferable size. And discharge occurs in the discharge bulb due to the resonance energy. The plasma generated by the discharge bulb is radiated to the outside through an opening such as a metal mesh provided in the resonator.

In this electrodeless discharge lamp lighting device, a distribution of the electric field intensity based on the wavelength of the microwave is generated inside the cavity resonator. For example, a microwave having a frequency of 2.45 GHz has a wavelength of about 12 cm in free space. If an attempt is made to cause a discharge in a region having a wavelength longer than a half wavelength, a light emission distribution having uneven light intensity will result. If the light emitting area is reduced by, for example, reducing the diameter of the discharge bulb in order to eliminate such unevenness in intensity, the unevenness in intensity is reduced, but the energy coupling becomes poor, and the luminous efficiency is reduced. there were.

Therefore, in order to solve such a problem, an electrodeless discharge lamp lighting device has been proposed in which a TM010 mode standing wave is generated inside a cylindrical resonator to discharge a discharge bulb. (For example, see JP-A-2-98)
096). In this electrodeless discharge lamp lighting device,
By reducing the height of the cylindrical resonator, the electric field intensity of the electric field generated in the central axis direction of the cylindrical resonator is increased. For example, even a small discharge bulb having an outer diameter of 1.3 cm or less emits light with high efficiency. Can be done.

[0005]

In the electrodeless discharge lamp lighting device having the above structure, the height of the cylindrical resonator is reduced to increase the electric field intensity of the electric field generated in the central axis direction of the cylindrical resonator. Even a relatively small discharge bulb can emit light with high efficiency. Since the height of the cylindrical resonator is reduced in this way, the discharge bulb and the metal cylindrical resonator are arranged close to each other, and particularly, the HI
In the case of D lighting, the metal cylindrical resonator had a high temperature due to radiant heat from the discharge bulb. By the way, the cylindrical resonator is provided with, for example, a mesh-shaped metal mesh portion so as to prevent microwave leakage and transmit visible light, but the metal mesh portion has low strength. In addition, there is a possibility that the cylindrical resonator is thermally deformed due to radiant heat from the discharge bulb, and a problem such as deterioration of the luminous flux occurs.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electrodeless discharge lamp lighting device having a long life and high efficiency.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a microwave generating means for generating microwave energy, and a non-transparent microwave and visible light. A microwave resonator in which a light-transmitting portion having a light-transmitting property is formed at least in part, and coupling means for coupling microwave energy generated by the microwave generation means to the microwave resonator, A discharge bulb formed of a material having a light-transmitting property and enclosing a discharge gas therein and disposed inside the microwave resonator, and each of the discharge bulbs is electrically connected to the microwave resonator, with the discharge bulb interposed therebetween. A pair of metal stubs arranged on the same straight line passing through the discharge bulb, and a pair of metal stubs electrically connected to the microwave resonator, respectively. Are arranged on the same straight line passing through the discharge bulb, and the electric field energy can be concentrated in a region between the pair of metal stubs, and a high electric field can be obtained in a relatively narrow region. By disposing the bulb, the discharge bulb can emit light with high efficiency.

According to a second aspect of the present invention, in the first aspect of the present invention, the portion of the metal stub facing the discharge bulb is formed in substantially the same shape as the shape of the shape of the discharge bulb projected. A substantially uniform electric field distribution can be generated over the entire bulb, and uneven light emission can be eliminated.

According to a third aspect of the present invention, in the first or second aspect, the metal stub is plate-shaped,
The electric field distribution can be made substantially uniform in the direction along the longitudinal direction of the metal stub, and unevenness of light emission of the discharge bulb can be reduced.

According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the portion of the metal stub facing the discharge bulb is formed to have substantially the same shape as the shape of the discharge bulb projected. The metal stub and the metal stub that are coupled to the microwave resonator are each formed in a shape that reduces chipping of light. By generating a strong electric field distribution, it is possible to eliminate unevenness of light emission, and a part of the metal stub facing the discharge bulb or a part of the metal stub coupled to the microwave resonator becomes a shadow, and the light of the discharge bulb becomes dark. Can be prevented from being chipped.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, at least one of the metal stubs is provided with an air outlet for blowing air for cooling the discharge bulb. Since the discharge bulb can be cooled by blowing air to the discharge bulb, the discharge bulb can be formed of an inexpensive material having low heat resistance, and the thermal stress applied to the discharge bulb can be reduced. Can extend the life of the device.

According to a sixth aspect of the present invention, in the first to fifth aspects, the microwave resonator is a hollow cylindrical resonator having a hollow cylindrical shape. To play.

According to a seventh aspect of the present invention, in the first to fifth aspects of the present invention, the microwave resonator is a hollow, rectangular tube-shaped rectangular cavity resonator, similar to the first to fifth aspects of the present invention. Has the effect of

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, a reflecting mirror for reflecting radiation emitted from a discharge bulb in a desired direction is provided in a part of the microwave resonator. As a feature, light can be distributed in a desired direction by the reflecting mirror, and since a part of the microwave resonator is a reflecting mirror, labor for assembling can be reduced.

According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the material of the metal stub is either silver or a silver alloy, and the heat resistance and the oxidation resistance of the metal stub are improved. be able to.

According to a tenth aspect of the present invention, in the first to eighth aspects, the surface of the metal stub is silver-plated, and the heat resistance and the oxidation resistance of the metal stub can be improved. .

According to the eleventh aspect of the present invention, the first to tenth aspects are provided.
The invention according to the invention, characterized in that a valve holding means for holding the discharge bulb is provided on the metal stub, and the discharge bulb is supported by the valve holding means, whereby the discharge bulb is reliably positioned between the pair of metal stubs. Therefore, a high electric field can be applied to the discharge bulb, and the discharge bulb can be lighted with high efficiency.

According to the twelfth aspect of the present invention, the first to eleventh aspects are provided.
In the invention, characterized in that a metal stub holding means formed of a non-conductive material for holding a metal stub is provided in the microwave resonator, by providing a metal stub holding means for holding a metal stub, The holding power of the metal stub can be increased.

According to the thirteenth aspect, the first to twelfth aspects are described.
In the invention, the discharge bulb is held by the metal stub holding means, and since the metal stub and the discharge bulb are held by the metal stub holding means,
The discharge bulb can be positioned between the pair of metal stubs, and a high electric field can be applied to the discharge bulb to light the discharge bulb with high efficiency.

According to the fourteenth aspect, in the twelfth aspect or the first aspect,
The invention according to the third aspect, characterized in that at least a part of the surface of the metal stub holding means is provided with a reflecting surface for reflecting the radiated light of the discharge bulb in a desired direction. In this case, the reflected light can be efficiently emitted to the outside.

According to the fifteenth aspect, the first to fourteenth aspects are described.
In the invention, a reflection member for reflecting the radiation light of the discharge bulb in a desired direction is attached outside the microwave resonator, and the reflection member reflects the radiation light of the discharge bulb in a desired direction. Thereby, the light emitted from the discharge bulb can be efficiently radiated to the outside.

[0022]

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

(Embodiment 1) Embodiment 1 of the present invention is shown in FIG.
This will be described with reference to FIGS. This electrodeless discharge lamp lighting device includes a microwave generator (microwave generator) 1 such as a magnetron that generates microwave energy.
And a microwave resonator 3 having a hollow cylindrical shape. The microwave radiated from the microwave generator 1 passes through the waveguide 2 and is provided with a coupling slot (coupling means) provided on the bottom surface of the microwave resonator 3. Microwave energy is supplied to the inside of the microwave resonator 3 through (7). The peripheral surface and the upper surface of the microwave resonator 3 are formed of a mesh-shaped metal mesh portion 3a, which is impermeable to microwaves and transmissive to visible light. The metal mesh part 3a constitutes a light transmitting part.

In the vicinity of the center of the microwave resonator 3, a discharge bulb 5 supported by a bulb support bar 6 is arranged. The discharge bulb 5 is formed in a spherical shape from a translucent material such as quartz glass, and has a discharge gas such as a rare gas or metal sealed therein. Further, a pair of metal stubs 4 and 4 are arranged on the same straight line passing through the discharge bulb 5 with the discharge bulb 5 therebetween. One end of each metal stub 4, 4 is coupled to the inner peripheral surface of the microwave resonator 3 and is electrically connected to the microwave resonator 3.
Is opposite to the discharge bulb 5 via a predetermined gap. It is desirable that the discharge bulb 5 is arranged near the center of the microwave resonator 3. However, in some cases, the discharge bulb 5 may be arranged at a position shifted from the center position of the microwave resonator 3.

Here, the microwave resonator 3 has a TE111 mode electromagnetic field distribution inside the resonator (FIG. 2 shows a TE111 mode electromagnetic field distribution generated in the hollow cylindrical resonator 3; Arrow A indicates an electric field distribution, and arrow B indicates a magnetic field distribution.). The vicinity of the center of the microwave resonator 3 in the center axis direction is An electric field A is generated in a direction orthogonal to the central axis direction (see FIG. 3). At this time, since the pair of metal stubs 4 and 4 are arranged in the direction of the electric field A near the center in the central axis direction of the microwave resonator 3, a high electric field is applied between the gap between the pair of metal stubs 4 and 4. The discharge bulb 5 disposed between the pair of metal stubs 4 can be lighted with high efficiency. For example, if the gap between the pair of metal stubs 4 and 4 is 6 mm, the discharge bulb 5 having an outer diameter of about 5 mm
Can be turned on, and can be used as a lamp of a point light source.

The material of the metal stub 4 is desirably a material having a small electric resistance and having heat resistance and oxidation resistance. For example, the metal stub 4 is preferably formed of a material containing silver such as silver or a silver alloy. . Also, instead of using silver or a silver alloy as the material of the metal stub 4, a silver plating layer may be formed on the surface of the metal stub 4, and the same effect as described above can be obtained.

In this embodiment, the discharge bulb 5 has a spherical shape and the metal stub 4 has a round bar shape. However, as shown in FIG. 4, the discharge bulb 5 is formed in a cylindrical shape with both ends rounded, and the metal stub is formed. 4 may be formed in an elliptical shape, and since the cross-sectional shape of the metal stub 4 is substantially the same as the shape of the projected discharge bulb 5, a substantially uniform electric field distribution over the entire metal stub 4 By generating
Light emission unevenness can be eliminated. It should be noted that the shape of the discharge bulb 5 and the metal stub 4 is not limited to the above-mentioned shape, and the portion of the metal stub 4 facing the discharge bulb 5 has substantially the same shape as the projected shape of the discharge bulb 5. The discharge bulb 5 can be formed in any shape, and by generating a substantially uniform electric field distribution over the entire discharge bulb 5, unevenness of light emission can be reduced.

Further, as shown in FIG. 5, the metal stub 4 may be plate-shaped, and the electric field distribution can be made substantially uniform in the direction along the longitudinal direction of the metal stub 4, so that the light emission unevenness of the discharge bulb 5 can be reduced. Can be reduced.

Further, as shown in FIG.
Is formed in a plate shape, and a disc portion 4a is protruded from a portion of the metal stub 4 facing the discharge bulb 5 so that the discharge bulb 5
Can be formed in substantially the same shape as the shape of the discharge bulb 5 projected on the surface of the metal stub 4 opposed to the metal stub 4, thereby generating a substantially uniform electric field distribution over the entire discharge bulb 5 and eliminating uneven light emission. In addition, since the portion of the metal stub 4 facing the discharge bulb 5 and the portion of the metal stub 4 coupled to the microwave resonator 3 are each formed in a plate shape, light of the light blocked by the metal stub 4 is formed. The amount (shadow of light) can be reduced. The portion of the metal stub 4 facing the discharge bulb 5 and the portion of the metal stub 4 coupled to the microwave resonator 3 may each be formed in a circular cross section.
As described above, it is possible to reduce the amount of light blocked by the metal stub 4 (shadow of light).

In this embodiment, the microwave generator 1
Uses the coupling slot 7 as the coupling means because the microwaves radiated through the waveguide 2 are propagated through the waveguide 2. However, if a coaxial line is used instead of the waveguide 2, an antenna should be used as the coupling means. Can also. Further, in the present embodiment, the microwave resonator 3 is formed in a hollow cylindrical shape. However, the shape of the microwave resonator 3 is not limited to a hollow cylindrical shape. May be used, or those having other shapes may be used.

(Embodiment 2) FIG. 7 shows Embodiment 2 of the present invention.
This will be described with reference to FIG. Since the configuration other than the metal stub 4 is the same as that of the first embodiment, illustration and description of common components will be omitted, and only different portions will be described.

In this embodiment, an air outlet 4 b for blowing air for cooling the discharge bulb 5 to the pair of metal stubs 4.
The discharge valve 5 can be cooled by blowing air (arrow C in FIG. 7) from the air outlet 4b to the discharge bulb 5. Therefore, the operating temperature of the discharge bulb 5 can be kept low, and the discharge bulb 5
Can be formed from an inexpensive material having low heat resistance, and the thermal stress applied to the discharge bulb 5 can be reduced, so that the life of the discharge bulb 5 can be extended.

In this embodiment, the air outlets 4b are provided in both of the pair of metal stubs 4.
Only the air outlet 4b may be provided, and the same effect as described above can be obtained by providing the air outlet 4b in at least one of the metal stubs 4 and air-cooling the discharge bulb 4.

(Embodiment 3) FIG. 8 shows Embodiment 3 of the present invention.
This will be described with reference to FIG. Since the configuration other than the metal stub 4 and the discharge bulb 5 is the same as that of the first embodiment, illustration and description of common components will be omitted, and only different portions will be described.

In this embodiment, recesses 4c, 4c are provided in the portions of the metal stubs 4, 4 facing the discharge bulb 5, and the recesses 4c, 4c are respectively formed on the surface of the discharge bulb 5 facing the recesses 4c, 4c. Fitted valve support rods 6,6
And the concave portions 4c, 4c and the valve support portions 6, 6
Are fitted together, the discharge bulb 5 is held by the metal stubs 4, 4. Here, valve holding means for holding the discharge bulb 5 from the recess 4c is configured.

As described above, the discharge bulb 5 is disposed between the pair of metal stubs 4 by fitting the recesses 4c, 4c and the bulb support rods 6, 6, respectively. Since the discharge bulb 5 is reliably positioned, a high electric field concentrated by the pair of metal stubs 4, 4 can be applied to the discharge bulb 5, and the discharge bulb 5 can be lit with high efficiency.

(Embodiment 4) FIG. 9 shows Embodiment 4 of the present invention.
Description will be made with reference to (a) and (b). Since the configuration other than the microwave resonator 3 'is the same as that of the first embodiment, illustration and description of common components will be omitted, and only different portions will be described.

In this embodiment, a hemispherical microwave resonator 3 'is used, and a reflecting surface 3b for reflecting the radiated light of the discharge bulb 5 in a desired direction is formed on the inner surface of the microwave resonator 3'. The metal mesh part 3a is formed in the part. The discharge bulb 5 is supported by a bulb supporting rod 6 whose base is coupled to the inner surface of the microwave resonator 3 ', and is disposed near the focal point of the reflection surface 3b, and the emitted light of the discharge bulb 5 is reflected by the reflection surface 3b. The light is reflected and distributed in a desired direction. Further, a pair of metal stubs 4 and 4
Are arranged on the same straight line passing through the discharge bulb 5, and one end is coupled to the reflection surface 3 b of the microwave resonator 3 ′ to be electrically connected to the microwave resonator 3 ′. The other end of the discharge bulb 5 through a predetermined gap.
Opposes.

Here, the microwave resonator 3 'is formed in such a size that a TE111 mode electromagnetic field distribution is generated inside the resonator, and is located near the center of the microwave resonator 3' in the central axis direction. Generates an electric field in a direction orthogonal to the central axis direction of the microwave resonator 3. At this time, since the pair of metal stubs 4 and 4 are arranged in the direction of the electric field near the center in the central axis direction of the microwave resonator 3, a high electric field is generated between the gap between the pair of metal stubs 4 and 4. As a result, the discharge bulb 5 disposed between the pair of metal stubs 4 and 4 can be lighted with high efficiency.

In the present embodiment, the reflecting surface 3a is provided on the inner surface of the microwave resonator 3 ', and a part of the microwave resonator 3' is a reflecting mirror. By reflecting the radiated light of the discharge bulb 5 in a desired direction, the radiated light of the discharge bulb 5 can be efficiently radiated to the outside.

(Embodiment 5) FIG. 1 shows Embodiment 5 of the present invention.
This will be described with reference to FIGS. In this embodiment,
In the electrodeless discharge lamp lighting device according to the first embodiment, rectangular metal stub holding plates (metal stub holding means) 8, 8 made of a non-conductive material are arranged inside the microwave resonator 3. . Each of the metal stub holding plates 8, 8 is arranged at a position symmetrical with respect to the central axis of the microwave resonator 3 while being in contact with the bottom surface and the peripheral surface of the microwave resonator 3. The upper surfaces of the metal stub holding plates 8, 8 are in contact with the metal stubs 4, 4, and the metal stubs 4, 4 are held by the metal stub holding plates 8, 8.
The configuration other than the metal stub holding plates 8 and 8 is the same as that of the first embodiment, and the illustration and description of the same components will be omitted.

As in the first embodiment, the microwave resonator 3 is formed in such a size that an electromagnetic field distribution of the TE111 mode is generated inside the resonator.
An electric field is generated near the center of the microwave resonator 3 in a direction orthogonal to the center axis of the microwave resonator 3. At this time, since the pair of metal stubs 4 and 4 are arranged in the direction of the electric field near the center in the central axis direction of the microwave resonator 3, a high electric field is generated between the gap between the pair of metal stubs 4 and 4. As a result, the discharge bulb 5 disposed between the pair of metal stubs 4 and 4 can be lighted with high efficiency.

The shape of the metal stub holding plates 8, 8 is not limited to the above-mentioned shape, and may have any shape as long as it has a function of holding the metal stubs 4, 4. On the surfaces of the metal stub holding plates 8, 8, a reflection surface made of a non-conductive material such as quartz, Pyrex (registered trademark), inorganic cement, silicon rubber cement or the like is formed. The emitted light may be reflected in a desired direction, and the emitted light from the discharge bulb 5 can be efficiently emitted to the outside.

(Embodiment 6) FIG. 1 shows Embodiment 6 of the present invention.
This will be described with reference to 1 (a) and (b). In the electrodeless discharge lamp lighting device according to the fifth embodiment, a pair of metal stub holding plates 8, 8 are provided.
Are arranged at symmetrical positions with respect to the central axis of the microwave resonator 3, and the metal stubs 4, 4 are placed on the upper surfaces of the metal stub holding plates 8, 8, respectively. And a substantially cylindrical metal stub holder (metal stub holding means) 9 formed of a non-conductive material made of a glassy substance such as Pyrex or quartz, or a metal oxide such as alumina or mica. 3, a pair of metal stubs 4 and 4 are placed on the upper surface of the metal stub holder 9. Since the configuration other than the metal stub holder 9 is the same as that of the first embodiment, illustration and description of the same components will be omitted.

A semi-spherical recess 9a is formed substantially at the center of the upper surface of the metal stub holder 9, and the base of the valve support rod 6 is embedded and fixed at the center of the recess 9a. The discharge bulb 5 is arranged in the recess 9a via the.
The pair of metal stubs 4 and 4 are arranged on the same straight line passing through the discharge bulb 5 with the discharge bulb 5 therebetween.
The metal stubs 4, 4 face the discharge bulb 5 via a predetermined gap. As described above, in the present embodiment, the discharge bulb 5 is held by the metal stub holder 9 that supports the metal stubs 4, 4, so that the discharge bulb 5 is reliably positioned between the pair of metal stubs 4, 4. By applying a high electric field to the discharge bulb 5, the discharge bulb 5 can be lighted with high efficiency.

Here, the upper half of the microwave resonator 3 is a mesh-shaped metal mesh portion 3a, which is impermeable to microwaves and visible light. , The light emitted from the discharge bulb 5 can be emitted from the metal mesh portion 3a to the outside. Further, the lower half of the microwave resonator 3 is a metal plate through which light cannot pass, and the strength of the microwave resonator 3 is higher than when the lower half is made of a metal mesh portion. Of the microwave resonator 3 can be prevented, and the deformation of the microwave resonator 3 can be prevented.

In the electrodeless discharge lamp lighting device according to the present embodiment, as shown in FIGS. 12A and 12B, a material having non-conductivity such as quartz, Pyrex, inorganic cement, or silicon rubber cement is used. The reflecting surface 10 may be formed on the entire upper surface of the metal stub holder 9, and the reflecting surface 10 reflects the radiated light of the discharge bulb 5 in a desired direction, so that the radiated light of the discharge bulb 5 is efficiently externally reflected. Radiation.

In the electrodeless discharge lamp lighting device of this embodiment, as shown in FIGS. 13A and 13B, a reflecting surface 10 for reflecting the radiated light of the discharge bulb 5 is provided on the upper surface of the metal stub holder 9. In addition to the above, a reflecting mirror 11, which is a substantially dome-shaped reflecting member, may be attached to the outside of the microwave resonator 3, and the reflected light from the discharge bulb 5 is reflected in a desired direction by the reflecting surface 10 and the reflecting mirror 11. Accordingly, the light emitted from the discharge bulb 5 can be more efficiently emitted to the outside.

In this embodiment, the metal stub holder 9 is arranged on the entire lower half of the microwave resonator 3. However, if the microwave stubs 4 and 4 have a function of holding, It is not necessary to provide the metal stub holder 9 on the entire lower half of the metal resonator 3, and the metal stub holder 9 may be provided on a part of the microwave resonator 3.

[0050]

As described above, according to the first aspect of the present invention, there is provided a microwave generating means for generating microwave energy, and is non-transparent to microwaves and transparent to visible light. A microwave resonator having at least a portion of a light-transmitting portion having: a coupling means for coupling microwave energy generated by the microwave generation means to the microwave resonator; and a light-transmitting material. A discharge bulb formed and filled with a discharge gas therein and disposed inside the microwave resonator; and a discharge bulb interposed between the discharge bulbs and electrically connected to the microwave resonator. And a pair of metal stubs, each of which is electrically connected to the microwave resonator, passes through the discharge bulb with the discharge bulb in between. Since the electric field energy is concentrated in a region between the pair of metal stubs and a high electric field can be obtained in a relatively narrow region, the discharge valve is arranged in this region. Can emit light with high efficiency.

According to a second aspect of the present invention, in the first aspect of the present invention, the portion of the metal stub facing the discharge bulb is formed to have substantially the same shape as the shape of the shape of the discharge bulb projected. An approximately uniform electric field distribution can be generated in the entire bulb, and there is an effect that unevenness of light emission can be eliminated.

According to a third aspect of the present invention, in the first or second aspect, the metal stub is plate-shaped, and the electric field distribution can be made substantially uniform in a direction along the longitudinal direction of the metal stub. Therefore, there is an effect that unevenness of light emission of the discharge bulb can be reduced.

According to a fourth aspect of the present invention, in the first to third aspects, the portion of the metal stub facing the discharge bulb is:
A portion of the metal stub facing the discharge bulb and a portion of the metal stub coupled to the microwave resonator are formed in substantially the same shape as the shape obtained by projecting the shape of the discharge bulb,
Each of them is characterized in that it is formed in such a shape that chipping of light is reduced, and by generating a substantially uniform electric field distribution throughout the discharge bulb, it is possible to eliminate unevenness of light emission and to face the discharge bulb. There is an effect that it is possible to prevent a portion of the metal stub to be formed and a portion of the metal stub coupled to the microwave resonator from being shaded, so that light of the discharge bulb is lost.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, at least one of the metal stubs is provided with an air outlet for blowing air for cooling the discharge bulb. Since the discharge bulb can be cooled by blowing air to the discharge bulb, the discharge bulb can be formed of an inexpensive material having low heat resistance, and the thermal stress applied to the discharge bulb can be reduced. This has the effect of extending the life of the device.

According to a sixth aspect of the present invention, in the first to fifth aspects, the microwave resonator is a hollow cylindrical resonator having a hollow cylindrical shape, and the same effects as those of the first to fifth aspects are provided. To play.

According to a seventh aspect of the present invention, in the first to fifth aspects of the present invention, the microwave resonator is a hollow, rectangular cylindrical cavity resonator, and is similar to the first to fifth aspects of the present invention. Has the effect of

According to an eighth aspect of the present invention, in the first to seventh aspects of the present invention, a reflecting mirror for reflecting the radiated light of the discharge bulb in a desired direction is provided in a part of the microwave resonator. As a feature, there is an effect that light can be distributed in a desired direction by the reflecting mirror, and since a part of the microwave resonator is a reflecting mirror, labor for assembling can be reduced.

According to a ninth aspect of the present invention, in the first to eighth aspects, the material of the metal stub is either silver or an alloy of silver, and the heat resistance and the oxidation resistance of the metal stub are improved. There is an effect of doing.

According to a tenth aspect, in the first to eighth aspects, the surface of the metal stub is silver-plated, and the heat resistance and the oxidation resistance of the metal stub can be improved. This has the effect.

According to an eleventh aspect of the present invention, in the first to tenth aspects, a valve holding means for holding the discharge bulb is provided on the metal stub, and the discharge bulb is supported by the bulb holding means. Accordingly, since the discharge bulb is reliably positioned between the pair of metal stubs, a high electric field can be applied to the discharge bulb, and the discharge bulb can be lit with high efficiency.

According to a twelfth aspect of the present invention, in the first to eleventh aspects, a metal stub holding means made of a non-conductive material for holding a metal stub is provided in the microwave resonator. By providing the metal stub holding means for holding the metal stub, there is an effect that the holding force of the metal stub can be increased.

According to a thirteenth aspect, in the first to twelfth aspects, the discharge bulb is held by the metal stub holding means, and the metal stub and the discharge bulb are held by the metal stub holding means. Therefore, the discharge bulb can be positioned between the pair of metal stubs, and there is an effect that a high electric field is applied to the discharge bulb and the discharge bulb can be lit with high efficiency.

The invention of claim 14 is the invention of claim 12 or 13
The present invention is characterized in that at least a part of the surface of the metal stub holding means is provided with a reflecting surface for reflecting the radiated light of the discharge bulb in a desired direction, and the radiated light of the discharge bulb is reflected by the reflecting surface in a desired manner. The reflection in the direction has an effect that the emitted light can be efficiently emitted to the outside.

According to a fifteenth aspect of the present invention, in any one of the first to fourteenth aspects, a reflecting member for reflecting the radiated light of the discharge bulb in a desired direction is mounted outside the microwave resonator. By reflecting the light emitted from the discharge bulb in a desired direction by the reflecting member, there is an effect that the light emitted from the discharge bulb can be efficiently emitted to the outside.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an electrodeless discharge lamp lighting device according to a first embodiment.

FIG. 2 is a diagram showing an electromagnetic field distribution of a TE111 mode in a cylindrical resonator.

FIG. 3 is a view showing an electromagnetic field distribution generated in a resonator used in the electrodeless discharge lamp lighting device of the first embodiment.

FIG. 4 is an enlarged view of a main part of another electrodeless discharge lamp lighting device of the above.

FIG. 5 is an enlarged view of a main part of another electrodeless discharge lamp lighting device of the above.

FIG. 6 is an enlarged view of a main part of still another electrodeless discharge lamp lighting device of the above.

FIG. 7 is an enlarged view of a main part showing an electrodeless discharge lamp lighting device according to a second embodiment.

FIG. 8 is an enlarged view of a main part showing an electrodeless discharge lamp lighting device according to a third embodiment.

FIG. 9 shows an electrodeless discharge lamp lighting device according to a fourth embodiment,
(A) is a top view which can partially omit, (b) is a side sectional view which can omit a part.

FIG. 10 shows an electrodeless discharge lamp lighting device according to a fifth embodiment;
(A) is a top view which can partially omit, (b) is a side sectional view which can omit a part.

FIG. 11 shows an electrodeless discharge lamp lighting device according to a sixth embodiment;
(A) is a top view which can partially omit, (b) is a side sectional view which can omit a part.

FIG. 12 shows another electrodeless discharge lamp lighting device of the above,
(A) is a top view which can partially omit, (b) is a side sectional view which can omit a part.

13A and 13B show another electrodeless discharge lamp lighting device of the above, wherein FIG. 13A is a top view in which a part is omitted, and FIG. 13B is a side sectional view in which a part is omitted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microwave generator 2 Waveguide 3 Microwave resonator 3a Metal mesh part 4 Metal stub 5 Discharge bulb 7 Coupling slot

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Eiji Shiohama 1048 Kadoma, Kadoma, Osaka Pref. Matsushita Electric Works, Ltd. F-term (reference) 3K072 AA17 DD04 GB08 5C039 PP04 PP08 PP12

Claims (15)

[Claims] 1. A microwave generating means for generating microwave energy, and a light transmitting portion which is non-transparent to microwaves and transmissive to visible light is formed at least in part. A microwave resonator, coupling means for coupling the microwave energy generated by the microwave generating means to the microwave resonator, and a discharge gas sealed in the inside formed of a material having a light transmitting property. A discharge bulb disposed inside the resonator, and a pair of metal stubs electrically connected to the microwave resonator and arranged on the same straight line passing through the discharge bulb with the discharge bulb interposed therebetween. An electrodeless discharge lamp lighting device comprising: 2. The electrodeless discharge lamp lighting device according to claim 1, wherein a portion of the metal stub facing the discharge bulb is formed in substantially the same shape as the shape of the projected discharge bulb. 3. The lighting device for an electrodeless discharge lamp according to claim 1, wherein the metal stub has a plate shape. 4. A portion of the metal stub facing the discharge bulb is formed in substantially the same shape as the shape of the projected discharge bulb, and is coupled to the portion of the metal stub facing the discharge bulb and the microwave resonator. 4. The electrodeless discharge lamp lighting device according to claim 1, wherein the portions of the metal stubs to be formed are each formed in such a shape that chipping of light is reduced. 5. The electrodeless discharge lamp lighting device according to claim 1, wherein at least one of the metal stubs is provided with an air outlet for blowing air for cooling the discharge bulb. 6. The electrodeless discharge lamp lighting device according to claim 1, wherein the microwave resonator is a hollow cylindrical hollow resonator. 7. An electrodeless discharge lamp lighting device according to claim 1, wherein the microwave resonator is a hollow, rectangular tube-shaped rectangular cavity resonator. 8. An electrodeless discharge lamp according to claim 1, wherein a reflector for reflecting radiation emitted from the discharge bulb in a desired direction is provided in a part of the microwave resonator. Lighting device. 9. The electrodeless discharge lamp lighting device according to claim 1, wherein a material of the metal stub is one of silver and a silver alloy. 10. The electrodeless discharge lamp lighting device according to claim 1, wherein the surface of the metal stub is silver-plated. 11. The lighting device for an electrodeless discharge lamp according to claim 1, wherein valve holding means for holding the discharge bulb is provided on the metal stub. 12. The electrodeless discharge lamp lighting device according to claim 1, wherein a metal stub holding means made of a non-conductive material for holding the metal stub is provided in the microwave resonator. . 13. An electrodeless discharge lamp lighting device according to claim 12, wherein the discharge bulb is held by metal stub holding means. 14. The metal stub holding means is provided with a reflecting surface on at least a part of the surface of the metal stub holding means for reflecting the emitted light of the discharge bulb in a desired direction.
The electrodeless discharge lamp lighting device as described in the above. 15. An electrodeless discharge lamp lighting device according to claim 1, wherein a reflecting member for reflecting radiation emitted from the discharge bulb in a desired direction is mounted outside the microwave resonator.