JP2000285870A - Microwave incandescent lamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave incandescent lamp device having a long life excellent in light emitting efficiency. SOLUTION: This microwave incandescent lamp device comprises a magnetron 5 for generating a microwave, a waveguide tube 6 being a transmission line for transmitting the microwave, a cavity component 7, and an arc tube 9 supported by a supporting rod 8 composed of a dielectric material, etc., and disposed inside the cavity component 7. The arc tube 9 is provided with an emitter supported by the supporting rod 8 inside a bulb. The microwave heats the emitter to emit light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave incandescent lamp device that emits light when a luminescent material is heated using microwaves.

[0002]

2. Description of the Related Art As shown in FIG. 3, a filament lamp conventionally used for an incandescent lamp has a filament 1 made of tungsten which generates heat at a high temperature when an electric current flows, a support rod 2 for supporting the filament 1, and A conductive lead wire 3 for passing an electric current is provided in a glass bulb 4. A small amount of a rare gas such as argon (Ar) is sealed in the glass bulb 4.

In a filament lamp, the filament 1 generates heat and emits light when an electric current is applied. The more the electric current is applied, the more the luminous amount increases and the luminous efficiency also increases. Since light is generated from the heated filament 1, it has excellent color rendering properties, and it is easy to make the filament 1 close to a point light source by reducing the size of the filament 1. Therefore, a filament lamp is used as a light source in a wide range.

[0004]

However, since the filament 1 which has reached a high temperature evaporates from its surface, the filament 1 gradually becomes thinner and eventually breaks, ending its life. The filament 1 needs to be made of a conductive material in order to flow an electric current, and furthermore, it is necessary to be made of a material which does not easily evaporate at a high temperature in order to maintain a certain life. For this reason, materials that can be used as the filament 1 are limited to metals, such as tungsten, and carbon, and there is a problem that it is difficult to extend the life of the filament lamp.

[0005] The present invention has been made to solve such problems, and an object of the present invention is to provide a microwave incandescent lamp device having a long life and excellent luminous efficiency.

[0006]

A microwave incandescent lamp device according to the present invention comprises a microwave oscillator, a transmission line for transmitting microwaves generated by the microwave oscillator, and a microwave cavity connected to the transmission line. And a luminous tube provided inside the microwave cavity forming member and enclosing a luminous body which emits heat by the microwave. With this configuration, the luminous body can be heated by the microwave to emit light.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a microwave incandescent lamp device according to one embodiment of the present invention includes a magnetron 5 as a microwave oscillator and a waveguide as a transmission line for transmitting the microwave generated by the magnetron 5. It includes a wave tube 6, a hollow component 7, and an arc tube 9 supported by a support rod 8 and provided in the hollow component 7.

The cavity forming member 7 is formed in a cylindrical shape by using a conductive mesh material or the like that does not transmit microwaves but transmits light, and is formed with the waveguide 6 so that microwaves do not leak outside. It is electrically connected. Magnetron 5
The generated microwave is transmitted through the waveguide 6 and supplied to the power supply port 10.
Through the cavity component 7 to form a microwave cavity in the cavity component 7.

As shown in FIG. 2, the luminous tube 9 is provided with a luminous bulb held in a bulb 11 made of transparent quartz glass or translucent ceramics by a support rod 12 made of quartz glass or translucent ceramics. A body 13 is provided. The inside of the arc tube 9 is in a vacuum of 0.013 Pa or less, or a rare gas such as Ar is sealed.

In such a microwave incandescent lamp device, when microwaves are transmitted into the cavity member 7, the luminous body 13 absorbs the microwaves and starts generating heat, is kept in a high temperature state, and starts emitting heat. . The luminous body 13 generates heat by absorbing microwaves, and does not need to be a conductive substance. Even if the luminous body 13 is broken and cracked or divided into several parts, if the position of the luminous body 13 within the luminous tube 9 does not largely move, the luminous body 13 generates heat. Since the light emission continues, the life of the filament does not end when the filament breaks in the conventional filament lamp. Therefore, the life of the arc tube can be greatly extended as compared with the conventional filament lamp.

As the luminous body 13, any substance that absorbs microwaves and is difficult to gasify at high temperatures can be used.
A conductive material such as a metal, a dielectric, an insulator coated or covered with a conductive material, or the like can be used. For this reason, the selection range of the material that can be used as the light emitter is expanded as compared with the conventional case. Here, a dielectric is a substance that does not conduct electricity, absorbs microwaves, and can generate and emit light, and an insulator is a substance that does not pass electricity, does not easily absorb microwaves, and does not emit heat. Since a material such as zirconium carbide, tantalum carbide, or hafnium carbide that is less likely to evaporate at a higher temperature than conventionally used tungsten can be used, it can be heated to a higher temperature than tungsten. Therefore, it is possible to provide a microwave incandescent lamp device having a higher color temperature than a filament lamp using tungsten and having excellent luminous efficiency.

Next, a specific example of the arc tube 9 will be described.
In the example shown below, the bulb 11 and the support rod 12 are made of quartz glass, and the diameter of the spherical portion of the bulb 11 is 30 mm.
And

As the luminous body 13 according to the first embodiment, a rod-shaped tungsten having a diameter of 0.3 mm and a length of 4 mm was used, and 13 kPa of Ar gas was sealed in the bulb 11.
The microwave power to be applied is about 100 W.
The microwave supplied into the cavity component 7 is
The rod-shaped tungsten, which is the luminous body 13 installed therein, can generate heat within a few seconds to emit light. In this embodiment, Ar gas is sealed in the arc tube 9, but a small amount of iodine,
A halogen element such as bromine or chlorine may be sealed. In this case, since the halogen cycle can be used, the life and efficiency of the microwave incandescent lamp device can be further improved.

As the luminous body 13 according to the second embodiment, a carbon rod having a diameter of 0.3 mm and a length of 4 mm was used.
1 was evacuated to a high vacuum of 0.013 Pa or less. The microwave power to be applied is about 200W. The microwave supplied into the hollow component member 7 can cause the carbon rod, which is the luminous body 13 installed in the luminous tube 9, to generate heat within several seconds to emit light. When the input microwave power is increased, the temperature of the carbon rod can be further increased, so that a high-luminance state with a high color temperature, which is difficult to obtain with a luminous body made of tungsten, can be obtained.

As the heating element 13 according to the third embodiment, a rod-shaped dielectric ceramic having a diameter of 0.5 mm and a length of 5 mm was used, and the valve 11 was evacuated to a high vacuum of 0.013 Pa or less. The microwave power to be applied is about 200W. The microwaves supplied into the cavity constituting member 7 can cause the dielectric ceramics, which are the luminous bodies 13 installed in the arc tube 9, to generate heat and emit light. When the input microwave power was increased, the luminous body 13 cracked, but luminescence continued.

As the luminous body 13 according to the fourth embodiment, a rod-shaped crystallized quartz glass having a diameter of 0.5 mm and a length of 5 mm and having a conductive layer made of iron formed on the surface was used. The valve 11 was evacuated to a high vacuum of 0.013 Pa or less. The microwave power to be applied is about 200W. The microwave supplied into the cavity component 7 can cause the luminous body 13 installed in the arc tube 9 to generate heat and emit light. In this case, since the crystallized quartz glass is an insulator and absorbs a small amount of microwaves, first, the conductive layer made of a conductive material absorbs microwaves and becomes hot, and accordingly, the crystallized quartz glass also becomes hot. . In this way, the luminous body 13 made of crystallized quartz glass having the conductive layer formed on the surface emits light.

In the fourth embodiment, the luminous body 13 having a conductive layer formed on the surface of crystallized quartz glass is used. Instead of the crystallized quartz glass, an insulator such as alumina having a high melting point is used. You may. Instead of the conductive layer, a layer made of a conductive material such as a carbon film or a dielectric layer made of a metal oxide such as alumina or zirconia can be used.

As the luminous body 13 according to the fifth embodiment, a pipe-shaped crystallized quartz glass having a diameter of 3 mm and a length of 5 mm filled with carbon powder as a conductive material was used. The valve 11 was evacuated to a high vacuum of 0.013 Pa or less. The input microwave power is about 200 W. The microwave supplied into the cavity component 7 can cause the luminous body 13 installed in the arc tube 9 to generate heat and emit light. Further, a pipe-shaped crystallized quartz glass may be filled with a metal oxide powder such as alumina or zirconia.

In the fifth embodiment, the crystallized quartz glass having a pipe shape is used as the light-emitting body 13, but an insulator such as alumina having a high melting point can be used instead of the crystallized quartz glass.

In the above-described embodiment, quartz glass is used as the bulb 11 as it is. However, fine white powder such as silica or a pigment having low microwave absorption may be applied to the inner or outer surface of the bulb 11. In this case, it can be used for a decorative light source or the like.

In the above embodiment, a waveguide is used as a microwave transmission path. However, a microwave may be transmitted using a coaxial line. In this case, an antenna or the like is used instead of the power supply port 10.

[0023]

As described above, the present invention provides a long life and high luminous efficiency by providing a luminous tube in which a luminous body which generates and emits heat by microwaves is enclosed inside a microwave cavity forming member. An object of the present invention is to provide a microwave incandescent lamp device capable of realizing an incandescent light source having a high color temperature.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a microwave incandescent lamp device according to an embodiment of the present invention.

FIG. 2 is a sectional view of an arc tube according to an embodiment of the present invention.

FIG. 3 is a sectional view of a conventional filament lamp.

[Explanation of symbols]

 Reference Signs List 5 magnetron 6 waveguide 7 cavity constituent member 8 support rod 9 arc tube 10 power supply port 11 bulb 12 support rod 13 luminous body

Continued on the front page (72) Inventor Katsushi Seki 1-1, Sachimachi, Takatsuki-shi, Osaka Matsushita Electronics Co., Ltd. F-term (reference) 3K073 AA00 AA16 AA87 CJ00 CJ14

Claims (5)

[Claims] 1. A microwave oscillator, a transmission line for transmitting microwaves generated by the microwave oscillator, a microwave cavity forming member connected to the transmission line, and a microwave cavity forming member provided inside the microwave cavity forming member. An incandescent lamp in which a luminous body which generates and emits heat by the microwave is sealed. 2. The microwave incandescent lamp device according to claim 1, wherein said luminous body is made of a conductive material. 3. The microwave incandescent lamp device according to claim 1, wherein said luminous body is made of a dielectric ceramic. 4. The microwave incandescent lamp device according to claim 1, wherein the luminous body has a layer made of a conductive material or a dielectric layer formed on a surface of an insulator. 5. The microwave incandescent lamp device according to claim 1, wherein the luminous body is provided with a conductive material or a dielectric inside an insulator.