JPH027352A - Electrodeless discharge lamp - Google Patents

Abstract

PURPOSE:To make it possible to effectively utilize its light output in its transverse direction and also reduce its leakage noises, by disposing a plate-shaped body with electric conductivity in such a way that its plate face is opposed to the face surrounded by induction coils and also a bulb abuts one part thereof. CONSTITUTION:If high frequency electric current is transmitted to induction coils 11, an electromagnetic field is induced and the electric-discharge gas body of the inside of a bulb 10 is excited and ionized. A plate-shaped body 12 then operates as a reflecting plate, for it is so constituted as to intensively reflect the light from the bulb 10 in its transverse direction. And also the plate-shaped body 12 has therewith the effect of reducing noises in its upward direction. Therefore, among the groups of magnetic flux generated in the induction coils 11, those which penetrate the inside of the bulb 10 assist in giving rise to its excitation light emission, while the rest of the flux become noises hence. As for leakage noises which penetrate the plate-shaped body 12, they can be reduced; it is because excess current generated by the magnetic flux penetrating the plate-shaped body 12 generates magnetic flux directed for weakening the magnetic flux penetrating the body.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an electrodeless discharge in which a rare gas or metal vapor inside the lamp is discharged and emitted light by a high-frequency '#C1 magnetic field from the outside, without having an electrode inside the lamp. Regarding lamps.

[Prior Art] This type of lamp has been known in the past, for example, the lamp disclosed in Japanese Patent Application Laid-Open No. 57-78766,
As shown in Fig. 5, a bulb 2 is formed to cover an air-core coil 1, and the mercury vapor inside the bulb 2 is discharged by an electromagnetic field generated by passing a high-frequency current through the air-core coil 1. , the magnetic field due to the cylindrical coil used here is
Although it is the strongest inside, in this example, there is no discharge space in that part, and the bulb 2 is formed by exclusively utilizing the magnetic field outside the coil.

In addition, in the lamp disclosed in U.S. Pat. No. 4,568,859, as shown in FIG.
Three short loops 3 are arranged along the outer peripheral wall of. However, with such a configuration, the magnetic flux generated by the short loop 3 is generated in a direction that weakens the original magnetic flux, and therefore the magnetic field within the valve 2 becomes weaker than in the case without the short loop 3. In other words, the light output is weakened.

[Problem to be solved by the invention] As described above, in conventional electrodeless discharge lamps, when trying to efficiently obtain light output, the leakage noise increases, and when trying to suppress the leakage noise, the light output efficiency decreases. There is a problem with doing so. Further, the above-mentioned leakage noise may cause radio wave interference that adversely affects other devices and the like.

The present invention has been made in view of the above-mentioned problems, and its object is to provide an electrodeless discharge lamp that can effectively utilize the light output in the lateral direction and has low leakage noise.

[Means for Solving the Problems] In order to solve the above problems, the electrodeless discharge lamp according to the present invention includes a conductive plate-like body, such that the plate surface faces the surface surrounded by the induction coil. Further, it is characterized in that a part thereof is arranged so as to be in contact with the valve.

[Example] Figures 1 to 3 show an example of the present invention.
0 is a spherical bulb that is airtight and translucent, and is filled with a rare gas such as argon as a discharge gas, or a metal such as mercury in addition to the rare gas. 1
1 is an induction coil wound along the lower outer peripheral wall of the bulb 10; 12 is a conductive plate-like body, which is fixed to the upper part of the bulb 10 so that a part thereof is in contact with the upper part of the bulb 10; It is made of metal and fixed with silicon, etc., which has good thermal conductivity. Further, the shape and mounting position of the plate-like body 12 are appropriately designed depending on the application.

Induction coil 1 of the electrodeless discharge lamp configured in this way
When a high frequency current is applied to the pulp 1, an electromagnetic field is induced, and the discharge gas in the pulp 1O is excited and ionized. that time,
Obtain visible light directly by excitation emission or use bulb 1
The ultraviolet rays generated by discharge excitation are converted into visible light using a phosphor coated on the inner wall surface of the 0. At this time, the plate-like body 12 functions as a reflecting plate and is configured to strongly reflect the light from the bulb 10 in the lateral direction. Furthermore, the plate-like body 12 also has the effect of reducing noise in the upward direction. In other words, out of the magnetic flux generated in the induction coil 11, the valve 1
Magnetic flux that penetrates within 0 contributes to excited light emission, but other magnetic flux becomes noise. Regarding the leakage noise that penetrates the plate-shaped body 12, the eddy current generated by the magnetic flux penetrating the plate-shaped body 12 generates a magnetic flux in a direction that weakens the penetrating magnetic flux, so that the noise can be reduced.

FIG. 4 shows an example of the application of the electrodeless discharge lamp according to the present invention, which is used in the above-mentioned aviation obstruction lamp. Such aircraft obstacle lights have a sealed structure for the purpose of waterproofing, and when the lamp is installed in a sealed lighting device, the temperature of the lamp rises and the temperature of the coldest part rises. Therefore, the light output decreases, making it impossible to obtain the desired light output. However, in this embodiment, the plate-like body 12 also serves as a heat sink, meaning that the portion of the bulb 10 that is in contact with the plate-like body 12 is The desired light output can be obtained. In addition, the presence of the plate-shaped body 12 makes it possible to effectively utilize the light output in the lateral direction, which is particularly effective as an aircraft obstruction light.

Note that the present invention is not limited to the above embodiments,
For example, in this embodiment, the induction coil 11 has a diameter ll1l.
1ll copper wire was used, but any material and wire diameter may be used as long as it is conductive. Further, the shape of the bulb 10 is not limited to a spherical shape either. Furthermore, a phosphor may be applied to the inner wall surface of the bulb 10, if necessary.

[Effects of the Invention] As described above, the present invention generates a high-frequency electromagnetic field with an induction coil wound along the outer wall of a bulb, and uses the skeleton frequency electromagnetic field to discharge a discharge gas body sealed in the bulb and emit light. In the electrodeless discharge lamp, a conductive plate is arranged so that its plate surface faces the surface surrounded by the induction coil described in No. 1111, and a part of it is in contact with the bulb. Therefore, according to the present invention, it is possible to provide an electrodeless discharge lamp with low leakage noise and high light output in the lateral direction of the lamp.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a sectional view of the same as above, Fig. 3 is a perspective view of an induction coil used in the above embodiment, and Fig. 4 is an electrodeless discharge according to the present invention. FIGS. 5 and 6 are partially sectional front views illustrating examples of lamp usage, and FIGS. 5 and 6 are partially sectional front views illustrating conventional examples, respectively. 10... Valve, 11... Induction coil, 12...
Platyform body.

Claims (1)

[Claims] (1) An electrodeless discharge lamp in which a high-frequency electromagnetic field is generated by an induction coil wound along the outer wall of the bulb, and the discharge gas sealed in the bulb is discharged and emitted by the high-frequency electromagnetic field. An electrodeless discharge lamp characterized in that a plate-like body having a plate-shaped body is arranged so that its plate surface faces a surface surrounded by the induction coil, and a part of the plate-like body is in contact with the bulb.