JPH0745381A - Electrodeless discharge lamp lighting unit - Google Patents

Abstract

PURPOSE:To provide an electrodeless discharge lamp lighting unit excellent in power efficiency. CONSTITUTION:A coil 2 for high-frequency power supply is arranged close to an electrodeless discharge lamp 1. An impedance coordination circuit 4 is connected to a high frequency power source 3, and high frequency power is supplied from the high-frequency power source 3 to the coil 2 for high frequency power supply so as to light the electrodeless discharge lamp 1. The high frequency power source 3 is composed of an oscillator 5 and an E-class power amplifying circuit 6. The E-class power amplifying circuit 6 amplifies the high frequency output signal of the oscillator 5 into E class, and it supplies it efficiently to the coil 2 for high frequency power supply. Moreover, high frequency power can be supplied more efficiently from the high frequency power supply 3 to the coil 2 for high frequency power supply by coordinating the impedance by means of the impedance circuit 4.

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 lighting device which emits light by applying a high frequency electromagnetic field to an electrodeless discharge lamp.

[0002]

2. Description of the Related Art FIG. 9 shows an example of a conventional electrodeless discharge lamp lighting device. The electrodeless discharge lamp 1 used is an interior of a bulb formed airtightly with a transparent material such as quartz or ceramics. A rare gas or a substance or metal vapor that excites and emits light when a rare gas is discharged is sealed therein, and a phosphor is applied to the inner tube surface as necessary. Electrodeless discharge lamp 1
A high-frequency power supply coil 2 formed of a metal having good conductivity is provided in the vicinity of the outer periphery of the coil. The high-frequency power supply 3 for supplying high-frequency power to the high-frequency power supply coil 2 and the impedance of the high-frequency power supply coil 2 and the high-frequency power supply 3 are matched, and reflection is eliminated to efficiently supply the high-frequency power to the electrodeless discharge lamp 1. The electrodeless discharge lamp lighting device is configured by connecting the impedance matching circuit 4 for transmission to the high frequency power supply coil 2. And
Several MHz from the high frequency power supply 3 to the high frequency power supply coil 2
To generate a high-frequency electromagnetic field in the high-frequency power supply coil 2, supply high-frequency power to the electrodeless discharge lamp 1, and generate a high-frequency plasma current in the electrodeless discharge lamp 1. It emits ultraviolet rays or visible light.

Here, the high frequency power supply 3 includes an oscillating section 5 for generating a high frequency voltage, and a C class power amplifier circuit 10 for amplifying the high frequency voltage by operating a large capacity MOS field effect transistor FET in the C class. It consists of and. The impedance matching circuit 4 is the capacitor C ₈ -C ₁₀
And the variable capacitor C _V, the output impedance of the high frequency power supply 3 and the electrodeless discharge lamp 1 serving as a load.
And the input impedance of the high frequency power supply coil 2 are matched, and the high frequency power of the high frequency power supply 3 is efficiently supplied to the high frequency power supply coil 2. The variable capacitor C _V of the impedance matching circuit 4 inserted in parallel with the high frequency power supply coil 2 is for adjusting the impedance of the impedance matching circuit 4 according to the manufacturing variations of the electrodeless discharge lamp. is there.

[0004]

In the above conventional structure, C is used.
There is a problem that the power efficiency of the high frequency power supply 3 that performs class power amplification is not very good. The present invention is intended to solve the above problems, and an object thereof is to provide an electrodeless discharge lamp lighting device provided with a high-frequency power source having high power efficiency.

[0005]

In order to achieve the above object, the invention of claim 1 is an electrodeless discharge in which a discharge gas such as a rare gas or a metal vapor is enclosed in a glass bulb and no electrode is provided inside. High frequency power supply including a lamp, a high frequency power supply coil disposed in the vicinity of the electrodeless discharge lamp, and a class D or class E power amplification circuit including at least a switching element, a resonance coil and a resonance capacitor It is characterized by comprising a high-frequency power source for supplying high-frequency power to the power coil and an impedance matching circuit for impedance matching between the high-frequency power source and the high-frequency power supply coil.

According to a second aspect of the present invention, in the first aspect of the invention, the impedance matching circuit connects at least two capacitors to the high frequency power supply coil in series and in parallel, and the impedance is adjusted in parallel to the capacitors connected in series. It is characterized by being connected with a variable capacitor for. According to a third aspect of the present invention, in the first or second aspect of the invention, at least one variable capacitor for impedance adjustment is connected to a resonance coil or a resonance capacitor that constitutes a class D or class E power amplifier circuit. Is characterized by.

The invention of claim 4 relates to claim 1 to claim 3.
In the described invention, the high frequency power source and the impedance matching circuit are connected by a coaxial cable, the output impedance of the high frequency power source is matched to the characteristic impedance of the coaxial cable, and the input impedance of the high frequency power supply coil is adjusted by the impedance matching circuit. It is characterized in that it is matched with the characteristic impedance of.

[0008]

In the structure of the first aspect of the present invention, a discharge gas such as a rare gas or a metal vapor is sealed in a glass bulb, and an electrodeless discharge lamp having no electrode inside and a discharge lamp disposed in the vicinity of the electrodeless discharge lamp are disposed. A high-frequency power supply coil provided; and a high-frequency power supply for supplying high-frequency power to the high-frequency power supply coil, comprising a class-D or class-E power amplification circuit including at least a switching element, a resonance coil, and a resonance capacitor.
Since the electrodeless discharge lamp lighting device is composed of the impedance matching circuit that performs impedance matching between the high frequency power supply and the high frequency power supply coil, the high frequency power supply performs class D or class E power amplification, thus improving power efficiency, Furthermore, by matching the output impedance of the high frequency power supply and the input impedance of the high frequency power supply coil, the high frequency power from the high frequency power supply can be efficiently supplied to the high frequency power supply coil.

According to another aspect of the present invention, the impedance matching circuit connects at least two capacitors in series and in parallel to the high frequency power supply coil, and the variable capacitors for impedance adjustment are connected in parallel to the capacitors connected in series. Since they are connected, the impedance of the impedance matching circuit can be changed by changing the capacitance of the variable capacitor to adjust the input impedance of the high frequency power supply coil.

According to the third aspect of the present invention, since at least one variable capacitor for impedance adjustment is connected to the resonance coil or the resonance capacitor forming the class D or class E power amplifier circuit, it is connected to the high frequency power source side. The output impedance of the high frequency power supply can be adjusted by changing the capacitance of the variable capacitor. According to the invention of claim 4, the high frequency power source and the impedance matching circuit are connected by a coaxial cable, the output impedance of the high frequency power source is matched with the characteristic impedance of the coaxial cable, and the input impedance of the high frequency power supply coil is impedance matched. Since the circuit matches the characteristic impedance of the coaxial cable, it is possible to efficiently supply high-frequency power from the high-frequency power supply to the high-frequency power supply coil via the coaxial cable, and to install the high-frequency power supply and the electrodeless discharge lamp separately. Therefore, the circuit element of the high frequency power supply can be protected from the heat generated by the electrodeless discharge lamp.

[0011]

【Example】

(Embodiment 1) A schematic circuit configuration diagram of this embodiment is shown in FIG.
As shown in FIG. 1, a high-frequency power supply coil 2 is arranged close to the electrodeless discharge lamp 1, and high-frequency power is supplied from the high-frequency power supply 3 to the high-frequency power supply coil 2 via an impedance matching circuit 4. The configuration is common to the conventional example, and the description of the common part is omitted.

The high frequency power source 3 is composed of an oscillating unit 5 and a class E power amplifier circuit 6, and a high frequency output signal of the oscillating unit 5 is class E amplified by the class E power amplifier circuit 6 to supply a high frequency power supply coil. 2 is supplied with high frequency power. The class E power amplifier circuit 6 uses the gate and source of a large-capacity MOS field effect transistor FET, which is a switching element, as an input side terminal and the drain and source as an output side terminal. The oscillator 5 is connected to the input side terminal, and the series circuit of the DC power supply Vd and the RF choke coil L ₁ is connected to the drain of the field effect transistor FET. The RF choke coil L ₁ is for making the current supplied from the DC power supply Vd to the field effect transistor FET substantially constant. Further, a capacitor C ₁ is connected in parallel between the drain and source of the field effect transistor FET, and a series resonance circuit of a resonance capacitor C ₂ and a resonance coil L ₂ is connected to the drain. The resonance frequency of the series resonance circuit is set to a value close to the operating frequency at which the field effect transistor FET operates by the high frequency output signal of the oscillator 5.

That is, the field effect transistor FET is turned on / off by the high frequency output signal of the oscillating unit 5 to interrupt the input signal from the DC power supply Vd, and the interrupted frequency is close to the resonance frequency of the resonance circuit. Since it is set, the high frequency signal of the oscillator 5 can be amplified with high efficiency. On the other hand, the impedance matching circuit 4 includes an impedance matching circuit 7 formed by connecting a coil L ₃ , a capacitor C ₃ and a capacitor C ₄ in a π type, a capacitor C ₅ in series with the high frequency power supply coil 2, and a capacitor C ₆ And an impedance matching circuit 8 formed by connecting a variable capacitor C _V1 in parallel. The impedance matching circuit 7 impedance-converts the output impedance of the high-frequency power supply 3, and the impedance matching circuit 8 impedance-converts the high-frequency power supply coil 2.
The input impedance and the output impedance are matched. Therefore, by performing impedance matching with the impedance circuit 4, high frequency power can be efficiently supplied from the high frequency power supply 3 to the high frequency power supply coil 2.

The variable capacitor C _V1 is for adjusting the impedance of the impedance matching circuit 8 according to the manufacturing variations of the electrodeless discharge lamp 1. (Embodiment 2) A schematic circuit configuration diagram of this embodiment is shown in FIG.
However, since the basic structure is common to the conventional example and the first embodiment, the description of the common parts will be omitted.

As shown in FIG. 2, in this embodiment, E
A capacitor C ₇ is connected in parallel to the output side terminal of the class power amplifier circuit 6. Therefore, the output impedance Z ₁ of the class E power amplifier circuit 6, FIG. 3 (a) and starting point X shown in (b), FIG impedance capacitor C ₂ viewed right from the point X of (a) 'And impedance Z ₂ can be converted into a series impedance, and the same figure (b)
It can be replaced with the equivalent circuit shown in.

Further, the impedance matching circuit 4 has a high frequency.
Capacitor C connected in series to the wave power supply coil 2_Five
And a capacitor connected in parallel to the high frequency power supply coil 2.
Sensor C₆And the above capacitor C_FiveVariable connected in parallel to
Capacitor C_V1It consists of and. Therefore, yes
Variable capacitor C_V1By changing the capacity of
The impedance of the impedance matching circuit 4 is the above capacitor
C₂’And impedance Z ₂Adjusted to the series impedance of
Characteristics, or also the characteristics of the electrodeless discharge lamp 1
Match the input impedance that fluctuates due to variations in
Can be adjusted to

Further, the voltage applied across the variable capacitor C _V1 when the electrodeless discharge lamp 1 is turned on is
Can be suppressed lower than the voltage applied to the high frequency power supplying coil 2, it is not necessary to use high capacitor with less breakdown voltage as a variable capacitor C _V1, the variable capacitor C _V1 itself can be miniaturized. (Embodiment 3) A schematic circuit configuration diagram of this embodiment is shown in FIG.
As shown in FIG. 4, in the present embodiment, the variable capacitor C _V2 is connected in parallel to the output side terminal of the class E power amplifier circuit 6 in the second embodiment, and the variable capacitor C _V1 of the impedance matching circuit 4 is removed. Has become. Therefore, the configurations other than the above are common to those of the second embodiment, and the description of the common parts will be omitted.

In the above structure, by changing the capacitance of the variable capacitor C _V2 , the output impedance of the high frequency power supply 3 is adjusted according to the input impedance of the high frequency power supply coil 2 due to the variation in the characteristics of the electrodeless discharge lamp 1. It is possible to match the input impedance of the coil 2 for high frequency power supply. In addition, the electrodeless discharge lamp 1
When starting lighting, the high frequency power is generated at both ends of the capacitor C ₆ by supplying high frequency power having a frequency close to the resonance frequency of the resonance circuit composed of the capacitors C ₅ , C ₆ and the high frequency power supply coil 2. Then, the electrodeless discharge lamp 1 can be started to light. On the other hand, the both ends of the variable capacitor C _V2, because the relatively low voltage than the high voltage developed across the capacitor C ₆ is applied, it is not necessary to use high capacitor with less breakdown voltage as a variable capacitor C _V2, variable The capacitor C _V2 itself can be miniaturized.

As shown in FIG. 5, in addition to the above configuration, a variable capacitor C _V3 is connected in parallel with the capacitor C _1, and two variable capacitors C _V2 and C _V3 adjust the output impedance of the high frequency power source 3. You may do it. Further, three or more variable capacitors may be connected to the high frequency power source 3 to adjust the output impedance. (Embodiment 4) A schematic circuit configuration diagram of this embodiment is shown in FIG.
As shown in FIG. 6, this embodiment is based on Embodiments 2 to 3.
And a coil 2 for supplying high frequency power.
The impedance matching circuit 4 is composed of a capacitor C ₅ connected in series to the high frequency power supply coil, a capacitor C ₆ connected in parallel to the high frequency power supply coil 2 and a variable capacitor C _V1 connected in parallel to the above capacitor C ₅ , and is of an E-class class. A variable capacitor C _V2 is connected in parallel to the output side terminal of the power amplifier circuit 6. It should be noted that description of common parts other than the above is omitted.

In the above structure, the input impedance of the high frequency power supply coil 2 including the electrodeless discharge lamp 1 is adjusted by the variable capacitor C _V1 , and the output impedance of the high frequency power supply 3 is adjusted by the variable capacitor C _V2 .
It is possible to match the respective impedances and prevent mismatches due to variations in the characteristics of the electrodeless discharge lamp 1.

(Embodiment 5) FIG. 7 shows a schematic circuit configuration diagram of this embodiment. As shown in FIG. 7, this embodiment is similar to the second embodiment.
The high frequency power source 3 in 3 and the impedance matching circuit 4 in Example 3 are connected by a coaxial cable 9. The description of the common parts will be omitted.

In the above structure, the output impedance of the high frequency power source 3 is matched with the characteristic impedance of the coaxial cable 9, and the input impedance of the high frequency power supply coil 2 is matched with the characteristic impedance by the impedance matching circuit 4. Therefore, the high frequency power supply coil 2 is fed from the high frequency power supply 3 via the coaxial cable 9.
High-frequency power can be supplied efficiently. Further, since the high frequency power supply 3 and the electrodeless discharge lamp 1 can be installed separately from each other by the coaxial cable 9, the circuit elements constituting the high frequency power supply 3 can be protected from the heat generated by the electrodeless discharge lamp 1. .

The impedance matching circuit 4 has the above-mentioned structure.
It is not limited to the configurations shown in the first to fifth embodiments.
In any of the configurations shown in FIGS.
Good. Ie inductive or capacitive impedance
Z₁~ Z_FourIn the same manner as this example, FIG.
Two impedance Z₁And Z₂In series with the input / output terminals
And the parallel connection.
Dance Z₁~ Z₃Are connected in a T-shape.
The same figure (c) shows three impedances Z₁~ Z ₃The π type
Connected to, and (d) in the figure shows four impeders.
Z₁~ Z_FourAre connected in a bridge shape.

Further, in the above-mentioned first to fifth embodiments, the case where the power amplifier circuit of the high frequency power source is the class E power amplifier circuit has been described, but it goes without saying that it may be a class D power amplifier circuit.

[0025]

According to the first aspect of the present invention, a discharge gas such as a rare gas or a metal vapor is sealed in a glass bulb, and an electrodeless discharge lamp having no electrode inside and a discharge lamp disposed close to the electrodeless discharge lamp are provided. A high-frequency power supply coil provided; and a high-frequency power supply for supplying high-frequency power to the high-frequency power supply coil, comprising a class-D or class-E power amplification circuit including at least a switching element, a resonance coil, and a resonance capacitor. Since the electrodeless discharge lamp lighting device is configured by the impedance matching circuit for impedance matching between the high frequency power supply and the high frequency power supply coil, the high frequency power supply is of class D or E.
There is an effect that the power efficiency is improved because the class power amplification is performed. Furthermore, with the output impedance of the high frequency power supply,
It is possible to match the input impedance of the high frequency power supply coil and to efficiently supply the high frequency power from the high frequency power supply to the high frequency power supply coil to further improve the power efficiency.

According to a second aspect of the present invention, the impedance matching circuit has at least two capacitors connected in series and in parallel to the high frequency power supply coil, and the variable capacitors for impedance adjustment are connected in parallel to the capacitors connected in series. Therefore, there is an effect that the impedance of the impedance matching circuit can be converted by changing the capacitance of the variable capacitor to adjust the input impedance of the high frequency power supply coil. In addition, since a high voltage is not applied to the variable capacitor of the impedance matching circuit when starting the electrodeless discharge lamp, it is possible to use a variable capacitor whose breakdown voltage is not so high, and thus it is possible to downsize the variable capacitor. .

According to the invention of claim 3, at least one variable capacitor for impedance adjustment is connected to the resonance coil or the resonance capacitor which constitutes the class D or class E power amplifier circuit. By changing the capacity of the variable capacitor connected to the high frequency power source side according to the variation, the output impedance of the high frequency power source can be adjusted to effectively supply the high frequency power to the high frequency power supply coil.

According to a fourth aspect of the present invention, the high frequency power source and the impedance matching circuit are connected by a coaxial cable, and
Since the output impedance of the high frequency power supply was matched to the characteristic impedance of the coaxial cable, and the input impedance of the coil for high frequency power supply was matched to the characteristic impedance of the coaxial cable by the impedance matching circuit, the high frequency power supply was supplied from the high frequency power source via the coaxial cable. Since high frequency power can be efficiently supplied to the coil for use and the high frequency power supply and the electrodeless discharge lamp can be installed separately from each other, the circuit element of the high frequency power supply is protected from the heat generated by the electrodeless discharge lamp to improve the reliability of the circuit element. The effect is that it can be improved.

[Brief description of drawings]

FIG. 1 is a schematic circuit configuration diagram showing a first embodiment.

FIG. 2 is a schematic circuit configuration diagram showing a second embodiment.

3 shows the same as above, FIG. 3A is a schematic circuit configuration diagram showing a high frequency power source, and FIG. 3B is an equivalent circuit diagram of FIG. 3A.

FIG. 4 is a schematic circuit configuration diagram showing a third embodiment.

FIG. 5 is a schematic circuit configuration diagram showing another configuration of the above.

FIG. 6 is a schematic circuit configuration diagram showing a fourth embodiment.

FIG. 7 is a schematic circuit configuration diagram showing a fifth embodiment.

FIG. 8 is a schematic circuit configuration diagram showing another configuration of the impedance matching circuit according to the first to fifth embodiments.

FIG. 9 is a schematic circuit configuration diagram showing a conventional example.

[Explanation of symbols]

1 electrodeless discharge lamp 2 frequency power supplying coil 3 high-frequency power source 4 impedance matching circuit 5 oscillation unit 6 E class power amplifier FET field effect transistor C ₁ -C ₆ capacitor C _V1 variable capacitor

Claims (4)

[Claims] 1. A non-electrode discharge lamp having no electrodes inside, and a high-frequency power supply coil disposed in the vicinity of the no-electrode discharge lamp, in which a discharge gas such as rare gas or metal vapor is sealed in a glass bulb. And a class D or E having at least a switching element, a resonance coil, and a resonance capacitor
An electrodeless discharge, comprising: a high-frequency power supply, which has a class-class power amplification circuit and supplies high-frequency power to the high-frequency power supply coil, and an impedance matching circuit for impedance matching between the high-frequency power supply and the high-frequency power supply coil. Electric lighting device. 2. The impedance matching circuit comprises at least two capacitors connected in series and in parallel to a high-frequency power supply coil, and a variable capacitor for impedance adjustment connected in parallel to the capacitors connected in series. The electrodeless discharge lamp lighting device according to claim 1. 3. A resonance coil or a resonance capacitor that constitutes a class D or class E power amplifier circuit, and at least one variable capacitor for impedance adjustment is connected to the resonance coil or the resonance capacitor. Electrode discharge lamp lighting device. 4. The coaxial cable connecting the high frequency power supply and the impedance matching circuit with a coaxial cable, matching the output impedance of the high frequency power supply with the characteristic impedance of the coaxial cable, and matching the input impedance of the high frequency power supply coil with the impedance matching circuit. 2. The characteristic impedance of the device is matched.
The electrodeless discharge lamp lighting device according to claim 3.