JPH10269817A - High-frequency electrodeless discharge lamp light reflector and high-frequency electrodeless discharge lamp apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-frequency electrodeless discharge lamp and a high-frequency electrodeless discharge lamp apparatus which can suppress irradiation in the infrared region and eliminate the need for the provision of a light reflector made of a nonconductive, low dielectric loss material in the interior of a microwave cavity or protective means against high-frequency wave leakage. SOLUTION: A high electrodeless discharge lamp has a configuration wherein a light reflector 13 made of a light reflective material is provided so as to be in contact with an exterior of a light transmitting conductive material 12 which forms a microwave cavity for supplying necessary energy for discharge to an electrodeless discharge lamp 11 or an exterior of a light transmitting conductive material which forms protective means against high-frequency wave leakage being provided in an exterior of high frequency energy supplying means. With this configuration, it can be possible that irradiation in the infrared region is suppressed and the need for the provision of a light reflector made of an expensive, low complex dielectric constant material in the interior of the microwave cavity or protective means against high-frequency wave leakage is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light reflector for a high-frequency electrodeless discharge lamp and a high-frequency electrodeless discharge lamp apparatus using the same.

[0002]

2. Description of the Related Art In recent years, high frequency electrodeless discharge lamps have been actively researched and developed as next-generation high-intensity discharge lamps due to the following characteristics.

[0003] Compared with an arc discharge lamp having electrodes, a high-frequency electrodeless discharge lamp can easily couple electromagnetic energy to a filler, can eliminate mercury from the filler for discharge luminescence, and has high luminescence. It has an excellent advantage that efficiency can be expected. 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.

In these high-frequency electrodeless discharge lamps, the shape of the light reflector is greatly restricted by the shape of the high-frequency energy supply means. However, in fields where uniform directional light emission is required, such as liquid crystal projection, the design of the light reflector is based on the light utilization efficiency (the amount of light that can be effectively irradiated within the amount of light emitted from the lamp). Amount). Therefore, the configuration of the light reflector for efficiently extracting the radiation light from the lamp to the outside is an important technical problem.

[0005] A light reflector of a conventional high-frequency electrodeless discharge lamp will be described below. JP-A-56-126250
In the "microwave discharge light source device" disclosed in Japanese Patent Application Publication No. H10-260, the electrodeless discharge lamp is formed in a spherical shape, and the inner wall surface of the microwave cavity is a reflection surface that considers the electrodeless discharge lamp as a point light source. Thereby, the illuminance distribution in the circular irradiation surface area is made uniform and has a desired distribution characteristic.

In the "reflector for collecting light in a reflectorless microwave driven lamp" disclosed in JP-A-7-45104, a first light reflector provided outside a microwave cavity is provided. (Reflector) and a second light reflector made of a non-conductive material provided inside the microwave cavity for reflecting light to the outside of the microwave cavity. ing. In addition, the design of the microwave cavity and the optical reflector can be performed separately, thereby increasing the degree of freedom in designing the microwave cavity.

[0007]

In the former "microwave discharge light source device" exemplified in the prior art, since the light reflector also serves as a microwave cavity, the material of the light reflector is a conductive material. (Mainly metallic materials).
Therefore, it is difficult to use a dichroic mirror or the like for suppressing reflection of infrared rays unnecessary for general lighting use. Further, when the optical reflector also serves as a microwave cavity, it is necessary to achieve both electromagnetic field design and optical design, and there is a problem that the design is very difficult.

In the latter "reflector for recovering light in a reflectorless microwave driven lamp", a first light reflector is provided outside a microwave cavity.
The second light reflector is provided inside the microwave cavity. This limits the second light reflector to materials that are non-conductive and have very low dielectric loss. Thus, there is a problem that the cost of the second light reflector provided inside the microwave cavity is much higher than the cost of the first light reflector provided outside the microwave cavity.

Furthermore, in recent years, excellent high-frequency energy supply means other than microwave cavities have been proposed, and a light reflector (and high-frequency leakage prevention means) suitable for high-frequency energy supply means other than these microwave cavities. Is needed.

[0010] In this specification, "high frequency" refers to an electromagnetic wave having a frequency of 1 MHz to 100 GHz.

[0011]

In order to achieve this object, a high-frequency electrodeless discharge lamp light reflector of the present invention and a high-frequency electrodeless discharge lamp device using the same are provided with a light-reflecting material made of a light-reflective material. A high-frequency leakage preventing means provided outside the light-transmitting conductive material forming the microwave cavity for supplying energy required for discharging the electrodeless discharge lamp or outside the high-frequency energy supplying means. It has a configuration provided so as to be in contact with the outside of the light transmitting conductive material.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 11 denotes an electrodeless discharge lamp in which mercury, metal halide, or the like is used as a light emitting material, and a rare gas such as argon is used as a buffer gas. The bulb of the electrodeless discharge lamp 11 has a spherical shape made of quartz glass, and is similarly supported inside the microwave cavity 14 by a support made of quartz glass. The microwave cavity 14 includes the light non-emission direction wall 12 a and the light emission direction wall 1.
2b, and is made of a light-transmitting conductive material such as a metal mesh. The microwave oscillated from the magnetron 16 serving as the microwave oscillating means is propagated to the microwave cavity by the waveguide 15 serving as the microwave propagating means, and supplies energy required for discharge to the electrodeless discharge lamp 11.

Of the light emitted from the electrodeless discharge lamp 11, the light emitted in the light emitting direction is the light emitting direction wall 12b.
Radiated directly from. On the other hand, light emitted in a direction other than the light emission direction passes through the light non-emission direction wall 12a, is reflected by the light reflector 13, and is extracted from the light emission direction wall 12b. FIG. 2 shows a detailed perspective view of the light non-emission direction wall 21 made of a metal mesh and the light reflector 22 provided in contact with the wall. As shown in FIG. 2, providing the metal mesh and the light reflector 22 so as to be in contact with each other has a desirable result for maintenance of a metal mesh having low mechanical strength.

The light reflector 13 is preferably made of heat-resistant glass such as Pyrex, and is preferably coated with a dichroic coat to reflect only visible light and not infrared light. When the shape of the light reflector 13 is a rotating radiation surface or a spheroidal surface in accordance with an optical system to be used, light utilization efficiency can be increased. At that time, the electrodeless discharge lamp 11 must be installed at a focal point on the rotation axis of the light reflector 13. The electrodeless discharge lamp 11 is installed at a position apart from the light emitting direction wall 12b, which is the end of the microwave cavity, by 1/4 tube wavelength (or an odd multiple thereof) from the viewpoint of electromagnetic field design. desirable.

With the above configuration, unnecessary irradiation in the infrared region can be suppressed as compared with the case where the light reflector is constituted only by the metal wall. In addition, the configuration in which the light reflector is in contact with the outside of the microwave cavity eliminates the need to provide a light reflector made of a non-conductive low dielectric loss material inside the microwave cavity. This greatly increases the degree of freedom in selecting the light reflector material.

(Embodiment 2) A case of using a high-frequency energy supply means other than a microwave cavity according to a second embodiment of the present invention will be described below with reference to FIG.

In FIG. 3, a high frequency oscillated by a magnetron, a semiconductor oscillator or the like is propagated through a coaxial tube 36 as a high frequency propagation means and a loop antenna 35 as a high frequency energy supply means through a loop antenna 35. The electrodeless discharge lamp 31 emits discharge light by coupling high-frequency energy by a resonance electromagnetic field generated at the center of the loop gap resonator 34. The walls 32a and 32b made of a light-transmissive conductive material such as a metal mesh prevent the leakage of high-frequency energy not coupled to the electrodeless discharge lamp 31.

The energy supply to an electrodeless discharge lamp using a loop gap resonator is disclosed in
No. 8127. FIG.
1 shows an example of a loop gap resonator disclosed in Japanese Patent No. 48127. The loop gap resonator 42 functions as an inductor L when a current flows through an annular loop, and functions as a capacitor C when electric charges accumulate in the gap. These L and C are electrically coupled, and resonate as an LC resonator. In FIG. 4, the electrodeless discharge lamp 41 can be kept on by the resonance magnetic field of the loop gap resonator 42 indicated by the dotted arrow.

As in the first embodiment, of the light emitted from the electrodeless discharge lamp 31, the light emitted in the light emitting direction is directly emitted from the light emitting direction wall 32b. On the other hand, light emitted in a direction other than the light emission direction passes through the light non-emission direction wall 32a, is reflected by the light reflector 33, and is extracted from the light emission direction wall 32b.

As in the first embodiment, the light reflector 33 is made of heat-resistant glass such as Pyrex, and is preferably applied with a dichroic coat or the like. Furthermore, the shape of the light reflector 33 is set as a rotating radiation surface or a spheroidal surface in accordance with the optical system to be used, and the electrodeless radiation lamp 1 is used.
It is needless to say that it is desirable to set 1 at the focal point on the rotation axis of the light reflector 33.

When such a high-frequency energy supply means is used, high-frequency waves not coupled to the electrodeless discharge lamp leak to the outside of the high-frequency energy supply means, so that a high-frequency leakage prevention means is required. At the time of starting or the like, since high-frequency energy is not sufficiently coupled to the electrodeless discharge lamp, particularly large energy leaks outside the high-frequency energy supply means. By making the configuration of the high-frequency leakage prevention means and the light reflector as described above, it is possible to simultaneously prevent high-frequency leakage and improve the light use efficiency of light radiation.

(Embodiment 3) The examples described in the first embodiment and the second embodiment are mainly "300M
Hz to 30 GHz "in the microwave band. Hereinafter, in the third embodiment of the present invention, “1 MHz” having a lower frequency than the microwave band is used.
The case where a frequency band of “300 MHz” is used will be described with reference to FIG.

In this frequency band, the H discharge system using an induction coil shown in FIG. 5 is most frequently used as a discharge energy supply means for an electrodeless discharge lamp. A high-frequency current generated from the high-frequency power supply 55 is converted into a high-frequency magnetic field by the induction coil 54. The electrodeless discharge lamp 51 installed inside the induction coil generates an induced current due to a high-frequency magnetic field, and thus, can start and maintain a discharge plasma inside the electrodeless discharge lamp 51. At the time of starting or the like, since high-frequency energy is not sufficiently coupled to the electrodeless discharge lamp 51, particularly large energy leaks outside the induction coil. The walls shown at 52a and 52b and made of a light transmissive conductive material such as a metal mesh prevent the leakage of these high frequency energies.

In this embodiment, similarly to the first and second embodiments, of the light emitted from the electrodeless discharge lamp 51, the light emitted in the light emission direction is the light emission direction wall 52b. Radiated directly from. On the other hand, light emitted in a direction other than the light emission direction is reflected by the light reflector 63 through the light non-emission direction wall 52a, and is reflected by the light emission direction wall 52b.
Thus, it is extracted as irradiation light.

Furthermore, by forming the shape of the light reflector 53 into a rotating radiation surface or a spheroidal surface in accordance with the optical system to be used, light emission characteristics suitable for the optical system can be obtained. The light reflector 53 is made of a heat-resistant glass such as Pyrex and is provided with a dichroic coat or the like, so that the irradiation of infrared radiation, which is emitted in large quantities by high-intensity discharge, is greatly suppressed. It is possible to do.

[0027]

As described above, according to the present invention, an optical reflector made of a non-conductive low dielectric loss material is provided inside a microwave cavity (or a high-frequency leakage prevention means) for suppressing radiation in the infrared region. An excellent high-frequency electrodeless discharge lamp light reflector which can eliminate the necessity, and a high-frequency electrodeless discharge lamp device using the same can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a high-frequency electrodeless discharge lamp light reflector according to a first embodiment of the present invention and a high-frequency electrodeless discharge lamp device using the same.

FIG. 2 is a detailed view of a high-frequency electrodeless discharge lamp light reflector according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a high-frequency electrodeless discharge lamp light reflector according to a second embodiment of the present invention and a high-frequency electrodeless discharge lamp device using the same;

FIG. 4 is a perspective view of a loop gap resonator according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of an H-discharge type high frequency electrodeless discharge lamp light reflector and a high frequency electrodeless discharge lamp device using the same according to a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 electrodeless discharge lamp 12 light-transmitting conductive member 13 light reflector 14 microwave cavity 21 light-transmitting conductive member 22 light reflector 31, 41, 51, 61 electrodeless discharge lamp 32, 52 light-transmitting conductive member 33, 53 light reflector 42 loop gap resonator 54 induction coil

Continuing on the front page (72) Inventor Koichi Katase 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. A light reflector made of a light-reflective material is provided on a light-transmitting conductive wall constituting at least a part of a microwave cavity for supplying energy required for discharging an electrodeless discharge lamp. A high-frequency electrodeless discharge lamp light reflector provided substantially in contact with the outside of the light-transmissive conductive wall not in the emission direction. 2. A light reflector made of a light-reflective material forms at least a part of a high-frequency leakage prevention means provided outside a high-frequency energy supply means for supplying energy required for discharging an electrodeless discharge lamp. A high-frequency electrodeless discharge lamp light reflector, which is provided substantially in contact with the light-transmitting conductive wall to be formed and on the outside of the light-transmitting conductive wall which is not in the light emission direction. 3. The high frequency electrodeless discharge lamp light reflector according to claim 1, wherein the light reflector has a heat-resistant glassy substance. 4. The high frequency electrodeless discharge lamp light reflector according to claim 1, wherein the light reflector is rotationally symmetric with respect to an axis parallel to a light emitting direction. 5. An electrodeless discharge lamp, microwave oscillating means for oscillating microwaves, a microwave cavity made of a light transmitting conductive material for supplying microwave energy to said electrodeless discharge lamp, A microwave propagation means for transmitting the microwave oscillated from the wave oscillating means to the microwave cavity; and a light reflector made of a light-reflective material, wherein the light reflector is a light-transmitting conductive material constituting the microwave cavity. A high-frequency electrodeless discharge lamp device, which is provided substantially in contact with an outer side of the light-transmitting conductive wall that is not in a light emission direction of a wall. 6. An electrodeless discharge lamp, high frequency oscillation means for oscillating high frequency, high frequency energy supply means for supplying high frequency energy to said electrodeless discharge lamp, and provided outside said high frequency energy supply means. A high-frequency leakage preventing means made of a light-transmitting conductive material, a high-frequency propagating means for transmitting high-frequency waves oscillated from the high-frequency oscillating means to the high-frequency energy supplying means, and a light reflector made of a light-reflective material; The high-frequency electrodeless discharge lamp device is characterized in that the lamp is provided substantially in contact with the light-transmitting conductive wall constituting the high-frequency leakage preventing means, not in the light emission direction of the light-transmitting conductive wall. 7. The high frequency electrodeless discharge lamp device according to claim 5, wherein the light reflector has a heat-resistant glassy substance. 8. The light reflector according to claim 5, wherein the light reflector is rotationally symmetric with respect to an axis parallel to the light emitting direction, and the electrodeless discharge lamp is provided on the rotationally symmetric axis of the light reflector. ~
8. The high frequency electrodeless discharge lamp device according to any one of items 7 to 7.