JPS60167256A - Electrodeless electric-discharge lamp - Google Patents

Abstract

PURPOSE:To enable magnetic line of force to be effectually utilized for emission by placing a pair of semispherical airtight bulbs having a concave area on their bottom in such a manner as to cause the concave areas to face each other and installing high-frequency oscillating coils in the concave areas. CONSTITUTION:Semispherical airtight bulbs 10a and 10b are prepared from glass or similar material and have concave areas 11a and 11b on their bottoms. The inner surfaces of the bulbs 10a and 10b are coated with a phosphor 12 and a light-transmitting high-frequency-electric-wave-shielding film 13. The bulbs 10a and 10b are charged with mercury and an inactive gas and connected facing each other by means of a cylindrical support 14. High-frequency oscillating coils 15a and 15b are placed in the concave areas 11a and 11b and connected to a power supply 17 through an oscillator 16. Owing to the above constitution of an electrodeless electric-discharge lamp, magnetic line of force can be effectually contributed to emission by equalizing the directions of the polarities of the oscillating coils 15a and 15b. Consequently, the luminous efficiency of the lamp can be increased and the leakage of electric wave can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an electrodeless discharge lamp in which metal within the bulb is excited by a high-frequency electromagnetic field to emit visible light through a bulb coated with a phosphor.

[Background technology]

Although general incandescent light bulbs are widely used, the efficiency of these incandescent light bulbs is low, on the order of 10 to 15ltn/W, and the lifespan is short, about 1,000 hours.

In contrast, ordinary fluorescent lamps have an efficiency of 50~go.
I! m/w is higher than incandescent bulbs, and the lifespan is approximately 5,000 yen.
Although time consuming and requiring long blind glass tubes and auxiliary ballasts, it is difficult to replace household incandescent light bulbs.

Against this background, various small fluorescent lamps with different incandescent lamp bases have been developed that can be directly adapted to currently installed incandescent lamp fixtures, and electrodeless discharge lamps are one of them. It is.

Figure $1 shows an example of such an electrodeless discharge lamp, and an airtight container made of a translucent material such as glass, so-called pulp 1, has a hemispherical shape with both ends 2 and 2' facing each other. There is a small diameter cylindrical part 3 connected between them.

A high frequency oscillation coil 4 is attached to the small diameter cylindrical portion 3.

The high frequency oscillation coil 4 is connected to the power supply 6 via the high frequency oscillator 5.
It is connected to the. Further, the inside 7 of the valve 7 rev 1 is filled with metal vapor such as mercury and inert gas such as argon as a fluorescence excitation gas. A phosphor 8 for preventing leakage of radio waves due to high frequency electromagnetic fields and a translucent high frequency radio wave shielding film 9 for preventing leakage of radio waves due to high frequency electromagnetic fields are attached.

In such a discharge lamp, a high-frequency electric field and a magnetic field are created by a high-frequency oscillation coil 4, and this electromagnetic field excites the metal vapor within the bulb both sides 2.2/ disposed at both ends of the coil 4. The ultraviolet light generated by ionization passes through the phosphor 8 on the inner surface of the pulp 1 and becomes visible light, which is emitted to the outside of the pulp 1. At that time, the lines of magnetic force go from the inner surface of the oscillation coil 4 to the outside from one end 2 of the pulp 1, pass through the outer periphery, and exit from the other end 21 of the pulp 1, as shown by the broken line in FIG. come inside.

At this time, a high frequency wave shielding film 9 is coated on the inner surface of the bulb 1 to prevent lines of magnetic force that may cause radio wave interference from exiting the bulb 1, but as a practical matter, It cannot be completely shielded and leaks to the outside to some extent. In this case, the lines of magnetic force are generated closer to the outer periphery than the center of the cylindrical space formed by the coil/L/4, and have a magnetic field that draws a short loop. That is, the magnetic field is stronger near the side of the valve 1 than near the center line. From this, the radio wave leakage is highest near the joint surface between the pulp both ends 2.2/ and the small diameter cylindrical part 3 connecting them. However, the magnetic field lines in this vicinity have a short distance to pass through the inside of the bulb 1, and do not contribute much to light emission due to discharge.

In other words, in an electrodeless discharge lamp configured as shown in Fig. 1, the magnetic lines of force generated near the outer periphery of the cylindrical space by the high-frequency oscillating coil I and 4 are meaningless in terms of luminous efficiency of the lamp, and are simply It only causes radio wave leakage, and despite its luminous efficiency, radio wave leakage is a major drawback.

[Purpose of the invention]

The present invention was made in view of the above-mentioned drawbacks, and its purpose is to reduce the magnetic lines of force generated by a high-frequency oscillation coil that do not contribute to light emission, and to reduce the leakage of radio waves from the lamp in an electrodeless discharge lamp. is to provide.

[Disclosure of the invention]

Hereinafter, the present invention will be explained based on the embodiment shown in FIG.
In Fig. 2, lOa and lob are hemispherical pulps having cavities 11a and llb on the bottom, respectively, and are airtightly formed of a translucent material such as glass, and the inner surface has phosphor particles and A high-frequency radio wave shielding layer B having translucent properties is applied. 14 is a cylindrical support that connects the pair of pulps LOa and LOb; 15a and 15b are the hollow portions 1;
A high frequency oscillation coil disposed in 1a and llb,
It is connected to a power source 17 via a high frequency oscillator 16 housed inside the support body 14 .

Note that, like the conventional example, at least one kind of metal vapor such as mercury and inert gas such as argon is sealed inside the valves lOa and lOb.

If the polarities of the oscillating coils 15a and 15b are, for example, as shown in FIG. 2, with the upper part being the N pole and the lower part being the S pole, then after the power supply 17 is turned on, the lines of magnetic force generated from both the oscillating coils 1v15a and 15b are as follows. Pulp IOa and IOb side (
In the diagram, most of the generation occurs to the left in the oscillation coil 15a on the left, to the right in the oscillation coil 15b on the right), and toward the center of the lamp (to the right in the oscillation coil L/15a on the left in the diagram, and to the left in the oscillation coil 15b on the right). Since the polarities of both oscillation coils 15a and 15b are the same, the generated lines of magnetic force repel each other and are reduced.

The magnetic lines of force coming out to each pulp lOa and lOb side excites metal vapor such as mercury in the pulp, and the ultraviolet rays generated by the ionization pass through the phosphor coated on the inside of the pulp and become visible. It becomes light and goes outside. From this, most of the magnetic lines of force generated by the oscillation coils 15a and 15b effectively pass through the pulps loa and lOb and contribute to light emission, so that the luminous efficiency is the same as above.

Moreover, in the above example, both pulp loa.

A high frequency oscillator 16 is installed inside the support 14 that connects the tab.
Since it is configured to accommodate the following, it is possible to achieve miniaturization.

〔Effect of the invention〕

As described above, the present invention comprises a bulb consisting of a pair of unsightly hemispherical containers each having a cavity on the bottom side, a high frequency oscillation coil is housed in each of the cavities, and the polarities of both oscillation coils are set to be the same. Since the magnetic field lines generated by the oscillation coil can effectively contribute to light emission, it is possible to improve luminous efficiency and provide an electrodeless discharge lamp with less radio wave leakage.

[Brief explanation of the drawing]

FIG. 1 is a simplified cross-sectional view of a conventional example, and FIG. 2 is a commercially simplified cross-sectional view of an embodiment of the present invention. 10a, lob...pulp, lla, llb...
Cavity, ν...phosphor, 15 a * 15 b...
・High-frequency oscillation carp M0 patent applicant Matsushita Electric Works Co., Ltd. Representative patent attorney Toshimaru Takemoto (and 2 others) Figure 1 Figure 2

Claims (1)

[Claims] (1) An electrodeless discharge in which metal vapor sealed inside a bulb is excited by an electromagnetic field generated by a high-frequency oscillating coil p, and visible light is emitted outside the bulb via a phosphor coated on the inner surface of the bulb. In the lamp, the pulp is formed by arranging a pair of hemispherical airtight containers having cavities on the bottom side so that the cavities face each other, and
An electrodeless discharge lamp characterized in that the high frequency oscillation coils are arranged in each of the cavities so that their polarities are in the same direction.