JP2009289489A - Electrodeless discharge lamp and luminaire - Google Patents

Abstract

[PROBLEMS] To prevent a decrease in light output under a wide range of ambient temperatures from low to high.
An electrodeless discharge lamp (1) includes a bulb (2) formed of a light-transmitting material such as glass in an airtight manner and an on-off valve (3) that opens and closes at a predetermined temperature. The on-off valve 3 is fixed to the inner peripheral surface of the heat radiating pipe 25 of the coupler 21 by inserting the tubular portion 6 through the insertion hole 3 a on the opening side of the recess 5 from the position of the metal container 7. When the ambient temperature is low, the on-off valve 3
By closing, the heat dissipation near the metal container 7 is suppressed, and conversely, when the ambient temperature is high, the on-off valve 3 is opened to promote the heat dissipation near the metal container 7. Therefore, a desired mercury vapor pressure can be obtained from the amalgam in the metal container 7 under a wide range of ambient temperatures from a low temperature to a high temperature, and a decrease in light output can be prevented.
[Selection] Figure 1

Description

The present invention relates to an electrodeless discharge lamp that emits a light-transmitting bulb that is airtight with an induction coil without an electrode, and a lighting apparatus that uses such an electrodeless discharge lamp.

Conventionally, a discharge lamp having a pair of electrodes in a glass tube is called an electrodeless discharge lamp having no electrode inside. This type of discharge lamp does not turn off due to electrode breakage or emitter consumption, and has a very long life compared to a discharge lamp having electrodes.

An electrodeless discharge lamp is generally formed of a light-transmitting material in a medium air-tight manner and includes a bulb in which mercury and a rare gas are enclosed. The bulb is composed of an outer shell part of a main light emitting part, a recess partly opened and recessed in the outer shell part, and a tubular part containing a mercury alloy for supplying the mercury. When a core around which an induction coil is wound is disposed in a space excluding the tubular portion in the recess and a high-frequency current is passed through the induction coil, a discharge is generated inside the bulb by an induction electromagnetic field. Due to the occurrence of this discharge, electrons collide with mercury atoms enclosed in the bulb. Then, the mercury atom enters an excited state, releases ultraviolet rays, and returns to the ground state. This ultraviolet light is converted into visible light by the phosphor applied on the inner surface of the bulb. The mercury alloy uses amalgam capable of stable light output in a wide temperature environment.
The mercury vapor pressure in the discharge space is determined by the temperature of the amalgam.

By the way, the above-mentioned electrodeless discharge lamp has a problem that the core itself receives heat due to the heat of the bulb or the resistance loss of the induction coil wound around the core, and the light output efficiency is lowered.

Therefore, conventionally, for the purpose of efficiently cooling the induction coil and the core, an electrodeless discharge lamp using a heat pipe and an electrodeless discharge lamp provided with irregularities on the outer peripheral surface of the core have been proposed (Patent Document 1). And 2).
Japanese Patent No. 2807305 JP 2003-317672 A

However, in the conventional example, when used in a very low temperature environment, the heat generated in the valve, the induction coil, and the core is convected in the space in the recess and released to the outside.
Amalgam cannot be warmed efficiently. Therefore, the mercury vapor pressure depending on the temperature of the amalgam is lower than the desired vapor pressure, and there is a problem that the light output is reduced. In addition, when actually attached to a lighting fixture, the heat generated in the bulb, induction coil, and core is trapped in the lighting fixture, the ambient temperature rises, and the temperature of the amalgam becomes too high. Therefore, there is a problem that the vapor pressure becomes higher than the desired vapor pressure and the light output is reduced.

The present invention has been made in view of the above reasons, and its purpose is to provide an electrodeless discharge lamp capable of preventing a decrease in light output under a wide range of ambient temperatures from low to high, and such an electrode. The object is to provide a luminaire using an electrodeless discharge lamp.

In order to achieve the above object, the invention of claim 1 is a valve which is formed in a medium airtight manner with a translucent material and sealed with a rare gas and mercury, and is closed at a predetermined temperature or lower and exceeds a predetermined temperature. An open / close valve that opens, and the bulb includes an outer shell portion of a main light emitting part, a concave portion that is partially open and recessed in the outer shell portion, and an internal space of the outer shell portion that is provided in the concave portion. And a tubular portion in which the amalgam for supplying the mercury is accommodated, and the on-off valve is a space excluding the tubular portion in the recess, and the opening side of the recess from the storage position of the amalgam It is provided in the space of.

According to this invention, the on-off valve is closed at a predetermined temperature or lower and opened when the predetermined temperature is exceeded, and the on-off valve is a space excluding the tubular portion in the recess, and the recess from the storage position of the amalgam. Since the opening and closing valve is closed when the ambient temperature is low, heat release near the storage of the amalgam is suppressed, and conversely when the ambient temperature is high, By opening the on-off valve, heat dissipation near the storage of the amalgam is promoted. Therefore,
It is possible to prevent a decrease in light output under a wide range of ambient temperatures from low to high.

According to a second aspect of the present invention, in the first aspect of the present invention, the on-off valve is made of bimetal.

According to this invention, since the on-off valve is formed of bimetal, it can deform itself at a predetermined temperature.

According to a third aspect of the invention, in the first aspect of the invention, the on-off valve is formed of a shape memory alloy.

According to this invention, since the on-off valve is made of a shape memory alloy, it can deform itself at a predetermined temperature.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the opening / closing valve is provided with a hole through which the tubular portion is inserted in a central portion in the horizontal direction.

According to the present invention, since the opening / closing valve is provided with the hole through which the tubular portion is inserted in the central portion in the horizontal direction, the on-off valve can be installed in the horizontal direction around the tubular portion.

The invention of claim 5 is characterized in that it comprises an appliance body that houses the electrodeless discharge lamp according to any one of claims 1 to 4.

According to this invention, the lighting fixture which has an effect similar to the invention of any one of Claims 1-4 can be provided.

In the present invention, there is an effect that it is possible to prevent a decrease in light output under a wide range of ambient temperature from low temperature to high temperature.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. As shown in FIG. 1, the electrodeless discharge lamp 1 of the present embodiment is closed at a predetermined temperature or lower with a bulb 2 formed in a medium airtight manner by a translucent material such as glass, and when a predetermined temperature is exceeded. And an open / close valve 3 that opens.

The bulb 2 has a light bulb shape as a whole, and includes an outer shell portion 4, a recess portion 5, and a tubular portion 6. Mercury and a rare gas (such as argon or krypton) are enclosed in the bulb 2. Further, a protective film (not shown) made of a metal oxide such as alumina is formed on the inner surface of the valve 2.
Further, a phosphor (not shown) is applied on the protective film.

The outer shell portion 4 is a main light emitting portion, and is formed by communicating a substantially spherical portion and a substantially cylindrical portion. A locking groove 4a is formed on the outer peripheral surface of the substantially cylindrical portion.

The concave portion 5 is formed in a cylindrical shape in which one end of the substantially cylindrical portion of the outer shell portion 4 is opened and recessed in the outer shell portion 4.

The tubular portion 6 is formed in an elongated cylindrical shape having both ends opened. One end of the tubular portion 6 is coupled to the center of the bottom portion 5a at one end in the recess 5 and communicates with the internal space of the outer shell portion 4, and the other end is
It is provided toward the opening side of the recess 5. Further, the inner wall of the tubular portion 6 is provided with a protruding portion 6a that protrudes inward. First, a metal container 7 made of iron-nickel alloy is inserted through the opening at the other end of the tubular portion 6. Next, by inserting the elongated cylindrical glass rod 8, the metal container 7 is installed at a substantially central portion in the tubular portion 6 by the protruding portion 6 a and the glass rod 8.
And in the metal container 7, the amalgam (not shown) which supplies the said mercury in the valve | bulb 2 as mercury vapor | steam is accommodated. In the amalgam of this embodiment, for example, mercury is contained in a base metal made of an alloy of bismuth and indium at a content rate of 3.5%. The opening at the other end of the tubular portion 6 is melted and closed when the inside of the valve 2 is sealed.

As shown in FIGS. 2A and 2B, the on-off valve 3 is formed in a disk shape, and an insertion hole 3a through which the tubular portion 6 is inserted is provided at the center in the horizontal direction. The on-off valve 3 has an insertion hole 3a.
A plurality of substantially fan-shaped opening / closing pieces 3b are formed by being cut out at equal intervals in the horizontal direction from the peripheral edge of each. The on-off valve 3 is formed of a bimetal having a different coefficient of thermal expansion.
Made of magnesium alloy. This metal can deform itself at a predetermined temperature (for example, 100 ° C.). In addition, lead, tin, an indium alloy, etc. may be used. Further, in addition to the bimetal, a shape memory alloy such as a titanium alloy that is restored to its original shape depending on the temperature may be used. When the on-off valve 3 is below a predetermined temperature, as shown in FIG. 2A, all the on-off pieces 3b are aligned in the horizontal direction, and the valves are closed. On the contrary, when the predetermined temperature is exceeded, as shown in FIG. 2 (b), all the open / close pieces 3b are bent to one side in the axial direction, and the valve is opened. In addition, the description about the attachment position of the on-off valve 3 is mentioned later.

The electrodeless discharge lamp 1 described above is attached to a fixture body 20 of a lighting fixture as shown in FIG. In FIG. 1, only the coupler 21 and the base 22 are shown among the constituent members of the instrument body 20.

The coupler 21 includes an outer flange 23, a heat radiating cylinder 24, a heat radiating pipe 25, a ferrite core 26, and an induction coil 27. The coupler 21 as a whole has a substantially convex cross section, a cylindrical portion 21a having both ends open, and a disc-shaped step portion 21 formed at one end.
and b. The outer flange portion 23 and the heat radiation cylinder 24 are constituted by a cylindrical portion formed in a cylindrical shape whose both ends are open, and a disc portion whose one end is formed in a disc shape. And the cylindrical part of the thermal radiation cylinder 24 is extrapolated in the cylindrical part of the outer collar part 23, and the disk part of the mutual end is contact | abutted. The heat radiation cylinder 24 is made of an aluminum material having a high thermal conductivity.
The heat radiating pipe 25 is formed in a cylindrical shape having both ends opened by a copper material. An outer flange portion 23 and a heat radiating cylinder 24 are extrapolated on one side substantially half of the axial direction of the heat radiating pipe 25. On the other side, a ferrite core 26 formed in a cylindrical shape having both ends opened is extrapolated. Further, an induction coil 27 is wound around the outer peripheral surface of the ferrite core 26.

The base 22 is formed in a substantially cylindrical shape having both ends opened from a resin material or the like, and has a plurality of protrusions 22a protruding inward on the inner peripheral surface, and a disc-shaped locking portion having an insertion hole in the center. 22b is provided. The cylindrical portion 21 a of the coupler 21 is inserted from the one end side in the axial direction of the base 22 through the insertion hole, and the stepped portion 21 b of the coupler 21 is the locking portion 22 b of the base 22 and the inner peripheral surface of the base 22. Is fitted.

And the electrodeless discharge lamp 1 is attached to the instrument main body 20 as follows. First, the tubular portion 6 is inserted from the opening on the side having the ferrite core 26 and the induction coil 27 of the tubular portion 21a. At this time, the cylindrical portion 21a is simultaneously inserted from the opening of the concave portion 5, and the concave portion 5 and the coupler 2 are inserted.
1 is fitted. The plurality of protrusions 22 a of the base 22 are engaged with the locking grooves 4 a of the outer shell 4. Thereby, the electrodeless discharge lamp 1 is fixed to the instrument body 20.

As shown in FIG. 1, the on-off valve 3 has a tubular portion 6 inserted through the insertion hole 3 a to connect the coupler 2.
1 is fixed to the inner peripheral surface of the heat radiating pipe 25. By this on-off valve 3, the inner peripheral surface of the recess 5,
A space 9 surrounded by the outer peripheral surface of the tubular portion 6, the inner peripheral surface of the tubular portion 21a, and the outer peripheral surface is divided into two.
And the on-off valve 3 is provided in the opening side of the recessed part 5 rather than the position of the metal container 7 which accommodates the amalgam. This is because when the ambient temperature is low, the air that enters the space 9 in the recess 5 from the opening of the heat radiating pipe 25 is blocked before the position of the metal container 7. The on-off valve 3 of this embodiment is attached in a direction in which the on-off piece 3b is deformed toward the metal container 7 side. This is for accelerating the flow of air entering the recess 5 from the opening of the heat radiating pipe 25 when the ambient temperature is high. Although the heat radiating efficiency is somewhat reduced, the on-off valve 3 is mounted in the reverse direction described above. Also good.

Next, an embodiment of a lighting fixture according to the present invention will be described. The lighting fixture 30 is comprised from the fixture main body 20, the lighting circuit 31, the plug 32, the electric wire 33, and the electric wire 34, as shown in FIG. The instrument body 20 includes a reflector 35, a front panel 36, and the coupler 2 described above.
The electrodeless discharge lamp 1 is sealed and supported inside. The reflector 35 is formed in a substantially bell shape with an open bottom surface, and the outer flange portion 2 of the coupler 21 at the upper end portion in the opening.
3 is connected. The front panel 36 is formed in a disk shape from a translucent material,
It is attached to the peripheral edge below the reflector 35. One end of the electric wire 33 is connected to the induction coil 27 of the coupler 21 and the other end is connected to a lighting circuit 31 that supplies a high-frequency current. The lighting circuit 31 is connected to a power source (not shown) through a plug 32 and an electric wire 34.

Hereinafter, the operation of the electrodeless discharge lamp 1 of the present embodiment will be described. The light emission principle is the same as that of the above-described prior art, and the description thereof is omitted.

When the electrodeless discharge lamp 1 is attached to the fixture body 20 of the lighting fixture 30 and a high frequency current is supplied to the induction coil 27 of the coupler 21, an induction electromagnetic field is generated around the induction coil 27. The heat generated in the bulb 2, the ferrite core 26, and the induction coil 27 raises the temperature of the amalgam in the metal container 7 that determines the mercury vapor pressure in the bulb 2. At this time, if the ambient temperature is low, convection occurs in the space 9 in the case of the above-described prior art, and air having a low temperature enters from the opening of the recess 5 and the heat radiating pipe 25, and heat near the metal container 7 is taken away. On the other hand, in the case of the present embodiment including the on-off valve 3, as shown in FIGS. 2A and 4A, the on-off piece 3b is closed if the on-off valve 3 is below a predetermined temperature. Therefore, it is possible to block the entry of air having a low temperature (see the arrow in the figure). Therefore, heat dissipation near the metal container 7 can be suppressed, a temperature drop of the amalgam can be prevented, and a desired mercury vapor pressure can be obtained. On the other hand, when the ambient temperature is high, as shown in FIGS. 2B and 4B, if the on-off valve 3 exceeds a predetermined temperature, the on-off piece 3b opens to the metal container 7 side. The convection in the space 9 can be promoted (see the arrow in the figure). Therefore, heat dissipation near the metal container 7 can be promoted, a temperature rise of the amalgam can be prevented, and a desired mercury vapor pressure can be obtained.

Actually, in the electrodeless discharge lamp 1 of the present embodiment and the above-described electrodeless discharge lamp of the prior art,
Measurements were taken when the ambient temperature was changed. The results will be described with reference to FIGS. In FIG. 5, the horizontal axis X represents ambient temperature (° C.), the vertical axis Y represents amalgam temperature (° C.), the horizontal axis X in FIG. 6 represents ambient temperature (° C.), and the vertical axis Z represents light output efficiency (%). Show. In addition, the solid line A indicates the characteristics of the prior art, the broken line B indicates the characteristics of the present embodiment, and the arrow C indicates the desired amalgam temperature range.

As shown in FIG. 5, the amalgam temperature of the prior art increases in proportion to the increase in ambient temperature, and exceeds the range indicated by the arrow C when the ambient temperature is low and high. On the other hand, the amalgam temperature of the present embodiment shows a moderate increase with respect to the increase in the ambient temperature, and is within the range of the arrow C from beginning to end. Further, as shown in FIG. 6, the light output efficiency of the prior art decreases at low temperatures and high temperatures with respect to changes in ambient temperature, and particularly shows a significant decrease at low temperatures. On the other hand, the light output efficiency of the present embodiment has good results at low temperatures and high temperatures.

The electrodeless discharge lamp 1 of the present embodiment described above includes an on-off valve 3 that opens and closes at a predetermined temperature.
When the ambient temperature is low, the on-off valve 3 is closed to suppress heat dissipation near the metal container 7. Conversely, when the ambient temperature is high, the on-off valve 3 is opened to open the metal container 7. Promote nearby heat dissipation. Therefore, it is possible to prevent a decrease in light output under a wide range of environments where the ambient temperature ranges from low to high.

It is sectional drawing of embodiment of this invention. The on-off valve in the above is shown, (a) is a perspective view when the ambient temperature is low, and (b) is a perspective view when the ambient temperature is high. It is a perspective view when the electrodeless discharge lamp in the above is attached to a lighting fixture. The inside of a recessed part in the same as above is shown, (a) is a sectional view when the ambient temperature is low, and (b) is a sectional view when the ambient temperature is high. It is a characteristic figure of the amalgam temperature with respect to ambient temperature of this invention and a prior art example. It is a characteristic view of the light output efficiency with respect to the ambient temperature of the present invention and the conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrodeless discharge lamp 2 Valve 3 On-off valve 3a Insertion hole 5 Recessed part 6 Tubular part 7 Metal container 21 Coupler 25 Radiation pipe

Claims (5)

A valve that is formed of a light-transmitting material in an air-tight manner and is filled with rare gas and mercury, and an on-off valve that closes below a predetermined temperature and opens when the temperature exceeds a predetermined temperature. A tubular portion containing an amalgam that is provided in the concave portion and communicates with the internal space of the outer shell portion to supply the mercury. And the on-off valve is provided in a space excluding the tubular portion in the recess and in a space on the opening side of the recess from the storage position of the amalgam. lamp. 2. The electrodeless discharge lamp according to claim 1, wherein the on-off valve is made of bimetal. 2. The electrodeless discharge lamp according to claim 1, wherein the on-off valve is made of a shape memory alloy. 4. The electrodeless discharge lamp according to claim 1, wherein the opening / closing valve is provided with a hole through which the tubular portion is inserted in a central portion in a horizontal direction. An illumination fixture comprising an appliance main body that houses the electrodeless discharge lamp according to any one of claims 1 to 4.

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