JPH0799041A - Electrodeless discharge lamp and lamp device including the same, lighting equipment, road lamp - Google Patents

Abstract

PURPOSE:To prevent a going out and to suppress the variation of the brightness by forming a translucent bulb sealing a luminous material in a circular form, and connecting a tubing for starting sealing a rare gas for starting, to the translucent bulb by separating the inner side. CONSTITUTION:In the starting of an electrodeless discharge lamp 12, a voltage for starting is fed to an electrode 18 for starting from a high-frequency oscillation circuit, and at the same time, a high-frequency current is fed to exciting coils 25 so as to generate a high-frequency electric field in a bulb 14. A potential difference is generated between the electrode 18 and the electric field in the bulb 14, so as to generate a glow discharge to a rare gas in a tubing 16. As a result, a plasma discharge is induced in the bulb 14 to generate a ring form discharge 15, and a luminous material is ionized and excited so as to generate a light. When an optical sensor detects the lighting, a starting circuit is cut off. Since the amount of the discharge 15 is designated by the bulb 14, the variation of the phase difference between the lamp current and the voltage is reduced, so as to reduce the variation of the brightness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless discharge lamp in which plasma is generated in a bulb by a high-frequency excitation coil, and a luminescent substance in the bulb is caused to emit light by this discharge, a lamp device including the same, and a lighting fixture. ， Regarding street lights.

[0002]

2. Description of the Related Art Generally, in a well-known high-pressure metal vapor discharge lamp, that is, an HID discharge lamp, electrodes are arranged in a bulb, so that a sealing structure of the electrodes becomes complicated and a leak from an electrode sealing portion occurs. It is necessary to take special measures to prevent
Moreover, since the electrodes are exposed to the discharge space, various problems such as erosion of the electrodes occur.

Therefore, an electrodeless discharge lamp has been attracting attention as a lamp that solves the above-mentioned problems of the electrode type discharge lamp. In this type of conventional electrodeless discharge lamp, as shown in FIG. 7, a luminescent material is enclosed in an elliptic spherical transparent bulb 1, and a high frequency excitation coil 2 is arranged so as to surround the bulb 1. On one side of the valve 1, a starting thin tube 3 which is preferably made of the same material as the valve is connected as an internal part of the valve 1. At least one kind of argon or krypton, for example, is filled in the thin tube 3 as a starting rare gas.

When this is turned on, a high frequency voltage is applied to the starting electrode 4 of the thin tube 3. Then, a potential difference is generated between the starting electrode 4 and the high frequency electric field generated in the valve 1 by the high frequency magnetic field of the excitation coil 2,
As a result, glow discharge is generated in the thin tube 3 by the starting rare gas. Since this glow discharge causes an electric field gradient between the glow discharge and the inside of the bulb 1, a ring-shaped plasma discharge 5 is induced in the bulb 1. 8A shows a double-tube type electrodeless discharge lamp in which the bulb 1 shown in FIG. 7 is built in a translucent outer tube 6, and FIG. 8B shows the same figure (A). ) Is a plan view of FIG.

[0005]

However, in such a conventional electrodeless discharge lamp, since the bulb 1 has a substantially spherical shape, electric power cannot be sufficiently supplied into the bulb 1 and extinction occurs. However, there is a problem that the fluctuation of brightness is large.

That is, the diameter of the plasma discharge 5 depends on the bulb 1.
When the temperature of the valve 1 is low immediately after starting, for example, when the temperature of the valve 1 is low, it is formed small at the center of the valve 1 and gradually expands in the outer diameter direction and expands as the temperature of the valve 1 rises. Moreover, due to the expansion of the plasma discharge 5,
The phase difference between the lamp current and the voltage also changes.

For this reason, since the deviation of the current and voltage from the set phase gradually increases immediately after the start of the engine, the matching of the resonance circuit for supplying power to the high frequency coil changes, and the valve 1 In addition to not being able to supply sufficient power to the inside, fading occurs and brightness changes greatly.

Further, since the fluctuation of the phase difference between the lamp current and the voltage is large, an excessive reverse current flows through the power element such as FET of the high frequency oscillation circuit, or the current is rapidly changed, which causes damage. In some cases.

Therefore, the present invention has been made in view of such circumstances, and an object thereof is a highly efficient electrodeless discharge lamp capable of preventing extinguishing and suppressing fluctuation of brightness, and a lamp device including the same. , To provide lighting fixtures and street lights.

[0010]

The present invention is configured as follows in order to solve the above-mentioned problems.

The invention according to claim 1 of the present application (hereinafter, referred to as the first
Invention), a translucent bulb for enclosing a luminescent substance is formed in an annular shape, and a starting thin tube which is isolated from the inside and encloses a starting rare gas is connected to the bulb. And

Further, in the invention according to claim 2 of the present application (hereinafter referred to as the second invention), the starting thin tube is connected to the inner wall of the valve, and the tip portion thereof is extended to the central portion of the valve. After that, the external electrodes are provided so as to stand upright at right angles.

Further, the invention according to claim 3 of the present application (hereinafter referred to as the third invention) is characterized in that a flat high-frequency coil is arranged close to the valve according to claim 1 or 2. And

Furthermore, an invention according to claim 4 of the present application (hereinafter referred to as a fourth invention) is a starting circuit for applying a starting voltage to a starting electrode of a starting thin tube according to claim 1 or 2. A lighting device for applying a flat high-frequency voltage to the high-frequency coil according to claim 3 is provided.

The invention according to claim 5 of the present application (hereinafter referred to as the fifth invention) is the electrodeless discharge lamp according to claim 1 or 2, or the electrodeless discharge lamp according to claim 3 or 4. One of them is provided as a light source in the instrument body.

Furthermore, the invention according to claim 6 of the present application (hereinafter referred to as the sixth invention) is characterized in that the lighting fixture according to claim 5 is erected on a road.

[0017]

[Action]

<First to Sixth Inventions> Since the light-transmitting bulb is formed in an annular shape, the magnitude of the ring-shaped discharge plasma generated in the bulb can be regulated by this bulb. Therefore, the change in the diameter of the discharge plasma can be suppressed to be small immediately after lighting and after that, and the fluctuation in the phase difference between the lamp current and the voltage is small. As a result, it is possible to sufficiently supply electric power to the bulb, prevent the lamp from disappearing, and reduce the fluctuation in brightness.

Further, it is possible to prevent damage to the power element such as FET.

<Second Invention> Since the starting thin tube stands outward from the central portion of the annular valve, the annular valve is built in the light-transmitting outer tube to form a double tube. In this case, the outer tube and the valve of the inner tube can be easily provided concentrically, and the structure of the double tube becomes very easy.

<Fourth Invention> When the starting voltage is applied to the starting voltage of the starting thin tube by the starting circuit and the high frequency voltage is applied to the high frequency coil by the lighting circuit, it is generated in the starting electrode and the valve. A potential difference is generated between the high-frequency electric field and the high-frequency electric field, which causes a glow discharge due to the starting rare gas in the capillary. This glow discharge generates an electric field gradient between the glow discharge and the bulb, and a ring-shaped plasma discharge is induced in the bulb. This plasma discharge causes the light-emitting substance in the bulb to emit light, and the light is turned on.

[0021]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6, the same or corresponding parts are designated by the same reference numerals.

FIG. 3 is an overall configuration diagram of an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part thereof. In these figures, an electrodeless discharge lamp device 11 is a lamp 12 and a lighting device 13 for lighting the lamp 12. Have and.

The lamp 12 has a bulb 14, which is shown in FIG.
As shown in (B), it is formed in an annular shape by a high melting point glass such as synthetic quartz or a transparent ceramic material such as alumina. In the bulb 14, a luminescent substance that emits light by a ring-shaped arc discharge 15 induced by plasma, for example, a metal halide, NaI-Ce.
I ₃ is enclosed. In addition to the light emitting substance, at least one rare gas for starting such as argon, xenon, krypton, neon, etc. is enclosed in the bulb 14.

A starting thin tube 16 is connected to the outer surface of the inner peripheral portion of the valve 14. This thin tube 16 is a valve 14
It is desirable that the valve 1 is made of the same material as
The inside of 4 is isolated via a partition wall 17. The starting thin tube 16 once extends from the outer surface of the inner peripheral portion of the valve 14 to the central portion of the valve 14, and then bends at a substantially right angle at the central portion and stands up. At least one of argon and krypton is enclosed as the rare gas. A starting electrode 18 is attached to the tip of the starting thin tube 16. In the case of the present embodiment, a reduced diameter portion 19 is formed at the tip of the thin tube 16, and a split ring type starting electrode 18 is fitted into the reduced diameter portion 19.

Such a starting electrode 18 is used for the capacitor 2
0a, 20b and an impedance 20c are connected to a starting circuit 20, and the starting circuit 20 is connected to a high frequency oscillation circuit 22 via a matching box 21.

The starting circuit 20 includes a switching means 2
3 is provided. The switching means 23 comprises an electronic switch or the like, and the starting circuit 20 until the lamp is activated.
Open and close intermittently. That is, this switching means 2
3 has an effect of alternately turning on and off, such as turning on the starting circuit 20 for 1 second, turning it off for 1 second, and then turning it on again for 1 second.

It should be noted that the switching means 23 can be switched so as to stop the on / off repetition and keep the off state when a signal from the optical sensor 24 is received. The optical sensor 24 emits a signal by detecting the light emitting state of the bulb 14.

An excitation coil 25 is arranged around the valve 14. The excitation coil 25 has one end connected to the high frequency oscillation circuit 22 via the matching box 21 and the other end connected to the ground 26, and 13.56 supplied from the high frequency oscillation circuit 22.
A high frequency current of about MHz is applied.
Due to such a high-frequency current, a magnetic field is generated in the excitation coil 25 along the coil axis direction O-O of the excitation coil 25, whereby a coil is generated in the valve 14 accommodated in the central space of the excitation coil 25. A donut-shaped arc discharge 15 is generated by the plasma so as to surround the axis OO. The arc discharge 15 ionizes and excites the luminescent metal to emit light, which passes through the bulb 10 and is emitted to the outside.

The exciting coil 25 has a pair of upper and lower ring-shaped metal discs 25a, 2 whose conductors corresponding to the coil wires are high-purity aluminum, copper, silver or the like and which have excellent conductivity.
5b. These pair of circular discs 25
a and 25b are arranged so as to face each other in the coil axis OO direction, and by forming a spiral-shaped energization path as a whole by welding and connecting a part of the inner peripheral portion to each other. That is,
The pair of annular discs 25a and 25b are not continuous in the circumferential direction, but are separated from each other in the circumferential direction, and the inner peripheral portion of one annular disc 25a and the other annular disc 2 are separated from each other.
The inner peripheral portion of 5b is partially connected to each other to form a spiral energization path as a whole.

Next, the operation of this embodiment will be described.

When starting the electrodeless discharge lamp 12, a starting voltage is supplied from the high frequency oscillation circuit 22 to the starting electrode 18, and at the same time a high frequency current is passed through the excitation coil 25.
An electric field is generated in the bulb 14 by the high frequency magnetic field. Then, a potential difference is generated between the starting electrode 18 and the electric field in the bulb 14, and the rare gas in the thin tube 16 causes glow discharge.

For this reason, an electric field gradient is generated between the glow discharge in the thin tube 16 and the electric field in the bulb 14 to induce plasma discharge in the bulb 14, and thus the ring-shaped discharge 1
2 occurs. This discharge 12 emits light when the luminescent substance in the bulb 14 is ionized and excited. When this light emission is detected by the optical sensor 24, the switching means 23 stops its operation, and thereafter the starting circuit 20 is left open while the lamp is on.

In this embodiment, since the bulb 14 is formed in an annular shape, the ring-shaped plasma discharge 12 generated by the bulb 14 has a size that is large immediately after the start-up and after the ignition. Is almost defined by, and the size variation can be almost suppressed.

For this reason, the variation in the phase difference between the lamp current and the voltage due to the variation in the diameter of the plasma discharge 12 is also suppressed, and the variation in matching for supplying the electric power to the excitation coil 25 is small. This will provide sufficient power to the valve 14
It can be supplied to the inside to prevent fading, and most of the fluctuations in brightness can be suppressed.

Further, since the fluctuation of the phase difference between the current and the voltage is small, it is possible to prevent the reverse voltage from being applied to the power element such as the FET of the high frequency oscillation circuit 22 or the current from being rapidly changed and damaged.

Further, the size of the doughnut-shaped plasma discharge 12 can be forcibly increased by enlarging the annular valve 14, while the inner diameter of the discharge 12 can be regulated to be small. By reducing the relative distance between the two, the degree of coupling between the excitation coil 25 and the discharge 12 can be increased, and the efficiency can be improved.

FIG. 4 shows an electrodeless discharge lamp 30 according to another embodiment of the present invention, which uses the bulb 14 of the electrodeless discharge lamp 12 of the above-described embodiment as a circular tube and has a translucent outer tube 3.
It is characterized in that it is built in 1 and configured as a double tube.

This electrodeless discharge lamp 12 is a starting thin tube 1.
Since 6 is erected at the center of the annular valve 14, the outer tube 31 can be easily and concentrically contained in the inner valve 14, and the center of gravity is also stable.

FIGS. 5 and 6 show still another embodiment of the present invention, which is a road lamp 40 using the electrodeless discharge lamp device 11 as a light source.

In FIG. 5, reference numeral 40a is a pole of an illuminating device for illuminating a road such as a highway, and an illuminating device 41 is installed at the upper end thereof. The height H of this pole 40a
Is set to λ / 2 or an integral multiple of λ / 2 with respect to the wavelength λ of the high frequency current supplied to the electrodeless discharge lamp device 11. For example, when the output frequency of the high frequency oscillation circuit 2 is 13.56 MHz, the wavelength λ is 22.1 m, while the height H of the pole 40a is λ / 2 = 11.1.
It is set to 05m.

As shown in FIG. 8, the lighting fixture 41 attached to the tip of the pole 40a has the lower surface opening of the fixture main body 42 closed by a prism cover 43. Is installed. This reflector 4
The electrodeless discharge lamp device 11 shown in FIG. 1 is installed at a predetermined position in the position 4. The light emitted from the electrodeless discharge lamp device 11 is reflected by the reflecting mirror 44,
The prism cover 43 controls the irradiation direction to irradiate the road. In the instrument body 41,
A main lighting circuit including a high frequency oscillation circuit 22 and a matching circuit 21 as shown in FIG. 1 for maintaining the lighting of the electrodeless discharge lamp 12 is provided on the printed circuit board 45 by wiring, and the discharge lamp is started. A starter circuit component 46 is housed therein.

One of the annular discs 25a of the high-frequency excitation coil 25 constituting the discharge lamp 12 has its ends integrally extended and is mechanically and electrically connected to the printed circuit board 45. The ring-shaped circular plate 25b is connected to the ground electrode 26 (FIG. 3) with the instrument body 42 as the ground. The instrument body 42 has the same potential as the ground through the pole 40a.

A fan 47 is provided in the instrument main body 42, and the fan 47 blows air for cooling to the discharge lamp 12 through ducts 48 and 49. The fan 47 is designed to be operated while the electrodeless discharge lamp device 11 is lit, so that the electrodeless discharge lamp device 11 is always forced by the ducts 48 and 49 by the wind generated by the fan 47 during lighting. To be cooled. For this reason, even if the tube wall of the valve 14 is heated by the ring-shaped plasma formed along the tube wall, the tube wall is forcibly cooled, so that the valve 14 is deformed or ruptured, and the undesired reaction of the encapsulating material is prevented. The temperature rise of the excitation coil 25 can be suppressed.

As a result, the electric field strength can be increased and concentrated to improve the startability, the lamp can be made into a single tube to be miniaturized, and the coil can be cooled, so that a large electric power can be obtained. Can also be added, and the luminous efficiency can be increased.

[0045]

As described above, in the first to sixth inventions of the present application, since the translucent bulb is formed in an annular shape, the size of the ring-shaped discharge plasma generated in the bulb is
It can be defined by this valve. For this,
Since the diameter change of the discharge plasma can be suppressed to be small immediately after lighting and after that, the fluctuation of the phase difference between the lamp current and the voltage is small. As a result, it is possible to sufficiently supply electric power to the bulb, prevent the lamp from disappearing, and reduce the fluctuation in brightness.

Further, it is possible to prevent damage to the power element such as FET.

In the second invention of the present application, the starting thin tube is
Since it stands up from the center of the annular valve to the outside, if this annular valve is built in a light-transmitting outer tube and configured as a double tube, the outer tube and the inner tube valve can be easily installed. Can be provided concentrically with each other, which makes the construction of the double tube very easy.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of an electrodeless discharge lamp according to the present invention.

2A is a plan view of the valve shown in FIG. 1, and FIG. 2B is a perspective view thereof.

FIG. 3 is an overall configuration diagram of an embodiment of an electrodeless discharge lamp device according to the present invention.

FIG. 4 is a front view of another embodiment of the present invention.

FIG. 5 is a side view of a road light showing still another embodiment of the present invention.

6 is an enlarged view of a main part of FIG.

FIG. 7 is a sectional view of a conventional electrodeless discharge lamp.

FIG. 8A is a front view of a conventional double tube wall electrodeless discharge lamp, and FIG. 8B is a plan view of FIG. 8A.

[Explanation of symbols]

 11 Electrodeless discharge lamp device 12 Electrodeless discharge lamp 13 Lighting device 14 Bulb 15 Plasma discharge 16 Starting thin tube 17 Partition wall 18 Starting electrode 20 Starting circuit 21 Matching box 22 High frequency oscillation circuit 24 Sensors 25a, 25b A pair of excitation coils 40 Road Light 41 Lighting fixture 42 Instrument body

Claims (6)

[Claims] 1. A translucent bulb for enclosing a luminescent substance,
An electrodeless discharge lamp, which is formed in an annular shape and to which a starting thin tube which is isolated from the inside and which contains a starting rare gas is connected. 2. The starting thin tube is connected to the inner wall of the valve, and the tip portion of the thin tube is extended to the central portion of the valve and then is erected in a right angle direction to provide an external electrode. Item 2. The electrodeless discharge lamp according to Item 1. 3. An electrodeless discharge lamp device characterized in that a flat high-frequency coil is arranged close to the bulb according to claim 1 or 2. 4. A starting circuit for applying a starting voltage to a starting electrode of the starting thin tube according to claim 1 or 2.
An electrodeless discharge lamp device comprising a lighting device for applying a high-frequency voltage to the flat high-frequency coil described. 5. A lighting fixture, wherein the electrodeless discharge lamp according to claim 1 or 2 or the electrodeless discharge lamp according to claim 3 or 4 is provided as a light source in a fixture body. 6. A road light comprising the lighting device according to claim 5 standing on a road.