JPH09147809A - Electrodeless fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodeless fluorescent lamp which improves build-up characteristics even discharge gas containing amalgam is used. SOLUTION: A bulb 1 includes discharge gas containing amalgam 4, and a high frequency current flows into an induction coil 2 adjacent to the bulb 1 so that a high frequency electromagnetic field is applied to the discharge gas, which is excited and luminescent. The amalgam 4 is collected in a tip part 1a provided around the coldest point on lighting in the bulb 1, and a lead part 2a of the induction coil 2 is arranged in the neighborhood of the tip part 1a. At startup, heat from the lead part 2a of the induction coil 2 is applied to the amalgam 4, thereby rapidly increasing mercury vapor pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention does not have an electrode in a bulb in which a discharge gas is enclosed, and a high-frequency electromagnetic field formed by passing a high-frequency current through an induction coil is applied to the discharge gas so that the discharge gas is discharged. The present invention relates to an electrodeless fluorescent lamp which discharges ultraviolet rays to emit ultraviolet rays and converts the ultraviolet rays into visible rays by a phosphor layer formed on a peripheral wall of a bulb.

[0002]

2. Description of the Related Art Conventionally, there is known an electrodeless lamp in which a discharge gas enclosed in a bulb is acted on by a high-frequency electromagnetic field to excite the discharge gas to emit light. Since this kind of electrodeless lamp has features such as small size, high output, and long life, research and development have been conducted in various places.

As an electrodeless lamp of this type, for example, as shown in FIG. 7, a bulb-shaped bulb 1 formed in a shape surrounding an induction coil 2 is known (Japanese Patent Publication No. 56-56).
No. 50385). A discharge gas containing mercury vapor is sealed in the bulb 1, and a high-frequency electromagnetic field formed by flowing a high-frequency current through the induction coil 2 acts on the discharge gas to excite the discharge gas and emit ultraviolet light. Let it do. Further, a fluorescent material layer is formed on the peripheral wall of the bulb 1, and the ultraviolet rays emitted from the discharge gas are converted into visible light and provided for illumination.

Here, in a small electrodeless fluorescent lamp, since the bulb 1 has a high temperature, there is a problem that the mercury vapor pressure becomes excessive during steady lighting and the efficiency is lowered. In order to solve this problem, it is necessary to control the mercury vapor pressure at high temperature to the optimum condition. Therefore, it has been considered to enclose amalgam (mercury + (Bi-In) or the like) as discharge gas in the bulb 1.

[0005]

By the way, the amalgam enclosed in the valve 1 for controlling the mercury vapor pressure is
Since the mercury vapor pressure is controlled to the optimum condition when the bulb 1 reaches a high temperature in the steady lighting state, the electrodeless lamp using the amalgam is a mercury vapor pressure from room temperature to the steady lighting state. The pressure is insufficient and a sufficient amount of light cannot be obtained. That is, there is a problem that the rising characteristics from the start of the electrodeless lamp to the steady lighting state are poor.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an electrodeless fluorescent lamp having improved start-up characteristics while using a discharge gas containing amalgam.

[0007]

In order to achieve the above object, the invention of claim 1 encloses an induction coil to which a high frequency current is applied, and a discharge gas having a shape surrounding the induction coil and containing an amalgam. And a bulb made of a translucent material with a phosphor layer on the peripheral wall, and the ultraviolet rays emitted by the discharge of the discharge gas by the action of the high-frequency electromagnetic field formed by the induction coil are converted into visible rays by the phosphor layer. In the electrodeless fluorescent lamp to be converted, a tip portion for accumulating amalgam is formed near the coldest point in lighting the bulb, and a lead portion for connecting the induction coil to a high frequency power source is arranged so as to pass near the tip portion. ing.

In order to achieve the above object, the invention of claim 2 encloses an induction coil to which a high-frequency current is applied, and a discharge gas containing an amalgam and having a shape partially inserted into the induction coil. And a bulb made of a translucent material having a phosphor layer on the peripheral wall, and the bulb emits ultraviolet rays emitted by the discharge of discharge gas due to the action of the high frequency electromagnetic field formed by the induction coil. In an electrodeless fluorescent lamp that converts to visible light, form a chip part that stores amalgam near the coldest point when lighting the bulb, and connect the lead part that connects the induction coil to a high frequency power source near the chip part. It is located in.

In the structure of the first and second aspects of the invention, when the lamp is started, the temperature of the induction coil rises rapidly due to radiation from the discharge plasma and self-heating of the induction coil. Here, the heat of the induction coil is radiated through the lead portion, and heats the amalgam accumulated in the chip portion formed near the lead portion of the induction coil. Therefore, the temperature of the amalgam will rise within a short time after the lamp starts, and the mercury vapor pressure controlled by the amalgam will reach a stable state in a relatively short time, improving the startup characteristics of the lamp. It

According to a third aspect of the present invention, in the first or second aspect of the invention, an auxiliary amalgam for controlling the mercury vapor pressure near room temperature to be lower than that of the amalgam is enclosed in the bulb and heated by the discharge plasma. As a result, an amalgam reservoir for accommodating the auxiliary amalgam is formed at a position where the mercury vapor pressure is controlled to be higher than that of the amalgam and in the vicinity of the lead portion of the induction coil.

According to this structure, when the lamp is started, the auxiliary amalgam stored in the amalgam reservoir is heated by both the discharge plasma and the lead portion of the induction coil. Will be heated first and the temperature will rise rapidly. As a result, the auxiliary amalgam functions in a short time after the lamp is started, and the rising characteristics are further improved as compared with the case where the amalgam is stored only in the tip portion.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) In this embodiment, as shown in FIG. 1, a valve 1 formed so as to surround an induction coil 2 is used. The bulb 1 is formed of a translucent material such as glass into a spherical shape, and has a peripheral wall partially recessed inward. In other words, the valve has a shape in which the peripheral edge of the opening window and the open end of the inner tube are joined by inserting the cylindrical inner tube with the tip closed into the spherical outer tube having the opening window formed in part. The outer tube and the inner tube are formed into an airtight space. In the bulb 1, a phosphor layer 3 is formed on at least the inner peripheral surface of the outer tube. The phosphor layer 3 may be formed on the outer peripheral surface of the inner tube, if necessary. Further, the induction coil 2 is inserted into the inner tube.

A discharge gas is enclosed in the bulb 1. As the discharge gas, for example, a rare gas such as argon and mercury and a metal forming an amalgam together with mercury (amalgam base metal) are enclosed. In the vicinity of the joint between the outer tube and the inner tube of the bulb 1 (this part is near the coldest point during lighting), the tip portion 1a is formed so as to project outward from the outer tube, In, the amalgam base metal is enclosed in the tip portion 1a. Here, the ratio of the amalgam base metal and mercury is set so that the luminous efficiency in the steady lighting state is the highest.

By the way, the induction coil 2 has a high frequency power source 8
A lead portion 2a is provided for connecting the induction coil 2 to a coaxial cable (not shown) for supplying a high-frequency current from (see FIG. 5). The lead portion 2a of the induction coil 2 is arranged so as to pass near the tip portion 1a in which the amalgam 4 is enclosed. With the above configuration, when a high frequency current from the high frequency power source 8 is passed through the induction coil 2, the high frequency electromagnetic field formed around the induction coil 2 acts on the discharge gas to excite mercury and emit ultraviolet rays. Will be done. This ultraviolet ray is converted into visible light by the phosphor layer 3 and provided for illumination.

By the way, the induction coil 2 is activated when the lamp is turned on.
Becomes high due to radiation heat from the discharge plasma, self-heating, etc., and the heat of the induction coil 2 is conducted through the lead portion 2a and radiated, and is stabilized at a temperature at which heating and heat radiation are in equilibrium. At the time of starting, however, the temperature of the induction coil 2 rapidly rises due to the radiant heat of discharge plasma and self-heating, so that the temperature of the lead portion 2a also sharply rises. Here, since the tip portion 1a is provided in the vicinity of the lead portion 2a, the amalgam 4 is heated by the lead portion 2a, and the mercury vapor pressure rises rapidly. Will be reached. That is, the rising characteristics are improved. As described above, with the simple configuration in which the lead portion 2a of the induction coil 2 passes near the tip portion 1a accumulating the amalgam 4, it is possible to improve the rising characteristics of the electrodeless fluorescent lamp using the amalgam 4. it can.

(Embodiment 2) In this embodiment, the lead portion 2
In order to accelerate the heating of the amalgam 4 by a, as shown in FIG. 2, between the lead portion 2a of the induction coil 2 and the chip portion 1a in which the amalgam 4 is encapsulated, an insulating heat conductive material such as silicone is used. 7 are provided. With this configuration, the efficiency of heat conduction from the induction coil 2 to the amalgam 4 is increased, and the rising characteristics of the electrodeless fluorescent lamp using the amalgam 4 can be further improved. Other configurations and operations are the same as those of the first embodiment.

(Embodiment 3) In this embodiment, the induction coil 2 is provided on the outer peripheral side of the valve 1. That is,
A part of the valve 1 is inserted inside the induction coil 2. The positional relationship between the valve 1 and the induction coil 2 is set so that a plane passing through the center of the induction coil 2 and orthogonal to the centerline direction passes through substantially the center of the valve 1. Further, the inner pipe of the valve 1 is formed shorter than that of the first embodiment. The lead portion 2a of the induction coil 2 is the first embodiment.
Similarly to the above, it is arranged so as to pass near the chip portion 1a. Other configurations and operations are similar to those of the first embodiment,
At the time of starting the lamp, heat is conducted from the induction coil 2 to the lead portion 2a, and this heat heats the amalgam 4 enclosed in the tip portion 1b.

(Embodiment 4) In this embodiment, as shown in FIG. 4, in addition to the structure of Embodiment 1, an auxiliary amalgam 5 is used.
Is provided. The auxiliary amalgam 5 is stored in an amalgam reservoir 6 arranged in a portion where the temperature rises faster than the tip portion 1a when starting the lamp (a portion that is likely to receive heat from the discharge plasma). Here, the auxiliary amalgam 6 is in the vicinity of the lead portion 2a of the induction coil 2 and the tip portion 1
It is arranged closer to the induction coil 2 than a. The auxiliary amalgam 6 is selected so that the mercury vapor pressure near room temperature can be controlled to be lower than that of the amalgam 4 accumulated in the tip portion 1b.

However, since the auxiliary amalgam 5 is heated by the discharge plasma at the time of starting the lamp, the mercury vapor pressure in the bulb 1 is increased by the auxiliary amalgam 5, and thereafter,
The heating of the amalgam 4 enclosed in the tip portion 1a increases the mercury vapor pressure. That is, compared with the case where the amalgam 4 is enclosed only in the tip portion 1a, the rise of the mercury vapor pressure can be further accelerated, and the rise characteristics of the electrodeless discharge fluorescent lamp using the amalgam can be further improved. it can.

By the way, in each of the above-mentioned embodiments,
Lead portion 2a on the power supply side and the ground side of the induction coil 2
Is preferably drawn from both sides of the induction coil 2 in the radial direction, as shown in FIG. Further, it is desirable that the lead portion 2a pulled out from the closed end side of the inner tube is passed through the inside of the induction coil 2. Alternatively, as shown in FIG. 6, the lead portion 2a pulled out from the closed end side of the inner pipe is connected to the induction coil 2
You may make it pass near the center line of. In this case, the lead portion 2a on the power source side is arranged along the vicinity of the center line of the induction coil 2, and the other lead portion 2a is on the ground side.

In general, when an electrodeless discharge fluorescent lamp is turned on, a high voltage is applied to both ends of the induction coil 2, so that a strong electric field is formed between both ends of the induction coil 2 and the electric field causes electrons to be ionized. Since the ions and ions are accelerated and collide with the phosphor layer 3, the deterioration of the phosphor layer 3 becomes large. However, in the case where the lead portion 2a of the induction coil 2 is arranged as shown in FIG. A relatively long distance can be taken between them, and the electric field across the induction coil can be made relatively small. That is, the phosphor layer 3
Is less likely to deteriorate.

Further, if arranged as shown in FIG. 6, the lead portion 2
The electric field across the induction coil 2 can be reduced and the lead wire 2a on the power source side, to which a high voltage is applied, can be separated from the phosphor layer 3 as compared with the case where they are arranged adjacent to each other. Moreover, since the electric field with the discharge plasma also weakens, the deterioration of the phosphor layer 3 can be further reduced.

[0023]

According to the first aspect of the present invention, an induction coil to which a high frequency current is applied, a discharge gas containing an amalgam and having a shape surrounding the induction coil, and a phosphor layer on the peripheral wall are provided. And a bulb made of a conductive material, which is premised on an electrodeless fluorescent lamp which converts ultraviolet rays emitted by discharge of discharge gas by the action of a high frequency electromagnetic field formed by an induction coil into visible rays by a phosphor layer. The invention of Item 2 is a translucent light having an induction coil to which a high-frequency current is applied, a discharge gas containing an amalgam having a shape partially inserted in the induction coil, and a phosphor layer on the peripheral wall. And a bulb made of a conductive material. The bulb emits ultraviolet rays emitted by the discharge of the discharge gas by the action of the high-frequency electromagnetic field formed by the induction coil into visible light by the phosphor layer. The invention is based on an electrodeless fluorescent lamp that can be replaced, and both inventions have a lead portion for connecting an induction coil to a high-frequency power source, in which a chip portion for accumulating amalgam is formed in the bulb near the coldest point during lighting. Since it is placed so that it passes near the tip, the temperature of the induction coil rises sharply due to radiation from the discharge plasma and self-heating of the induction coil when the lamp is started. Then, the amalgam accumulated in the tip portion formed near the lead portion of the induction coil is heated. As a result, the temperature of the amalgam starts to rise within a short time after the lamp starts, and the mercury vapor pressure controlled by the amalgam reaches a stable state in a relatively short time, improving the startup characteristics of the lamp. Have advantages.

According to the third aspect of the present invention, an auxiliary amalgam for controlling the mercury vapor pressure near room temperature to be lower than that of the amalgam is enclosed in the bulb and heated by discharge plasma so that the mercury vapor pressure becomes higher than that of the amalgam. An amalgam reservoir for accumulating the auxiliary amalgam is formed at a position that is controlled to be higher and near the lead portion of the induction coil, and the discharge plasma and the induction coil lead when the lamp is started. Since the auxiliary amalgam stored in the amalgam reservoir is heated by both the part and the part, the auxiliary amalgam is heated before the amalgam stored in the chip part, and the temperature rises sharply. As a result, the auxiliary amalgam functions in a short time from the start of the lamp, and there is an effect that the rising characteristics are further improved as compared with the case where the amalgam is stored only in the tip portion.

[Brief description of the drawings]

1A and 1B show a first embodiment, in which FIG. 1A is a vertical sectional view, and FIG.
FIG. 6 is a sectional view taken along line XX of FIG.

2A and 2B show a second embodiment, in which FIG. 2A is a longitudinal sectional view and FIG.
FIG. 6 is a sectional view taken along line XX of FIG.

3A and 3B show a third embodiment, in which FIG. 3A is a longitudinal sectional view, and FIG.
FIG. 6 is a sectional view taken along line XX of FIG.

4A and 4B show Embodiment 4 in which FIG. 4A is a longitudinal sectional view, and FIG.
FIG. 6 is a sectional view taken along line XX of FIG.

FIG. 5 is a perspective view showing an example of the shape of the induction coil in the embodiment.

FIG. 6 is a perspective view showing another example of the shape of the induction coil in the embodiment.

FIG. 7 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Valve 1a Chip part 2 Induction coil 2a Lead part 3 Phosphor layer 4 Amalgam 5 Auxiliary amalgam 6 Amalgam reservoir

Claims (3)

[Claims] An induction coil through which a high-frequency current flows,
A discharge gas containing an amalgam that has a shape surrounding the induction coil and is filled with a bulb made of a translucent material having a phosphor layer on the peripheral wall, and discharge by the action of a high-frequency electromagnetic field formed by the induction coil In an electrodeless fluorescent lamp that converts the ultraviolet light emitted by the discharge of gas into visible light through a phosphor layer, a tip part for accumulating amalgam is formed in the vicinity of the coldest point in lighting the bulb, and the induction coil is used as a high frequency power source. An electrodeless fluorescent lamp in which a lead portion to be connected is arranged so as to pass near the chip portion. 2. An induction coil to which a high frequency current is applied,
A high-frequency wave formed by an induction coil, which is provided with a bulb made of a translucent material having a shape in which a portion thereof is inserted into the induction coil and containing a discharge gas containing amalgam and having a phosphor layer on the peripheral wall. In the electrodeless fluorescent lamp that converts the ultraviolet light emitted by the discharge of the discharge gas by the action of the electromagnetic field into visible light by the phosphor layer, a tip portion for storing amalgam is formed near the coldest point in the lighting of the bulb, and An electrodeless fluorescent lamp in which a lead portion for connecting an induction coil to a high frequency power source is arranged so as to pass near the chip portion. 3. An auxiliary amalgam for controlling the mercury vapor pressure near room temperature to be lower than that of the amalgam is enclosed in a bulb and heated by discharge plasma to control the mercury vapor pressure to be higher than that of the amalgam. The electrodeless fluorescent lamp according to claim 1 or 2, wherein an amalgam reservoir for accumulating the auxiliary amalgam is formed at a position that is close to the lead portion of the induction coil.