JPH1055892A - High-frequency power feed device, electrodeless electric discharge lamp lighting device, lighting system and photochemical treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rated value of lamp power, regardless of the fluctuation of exciting coil inductance or the like resulting from a dispersion at a manufacturing process or a change with the lapse of time, regarding a lighting device for an electrodeless electric discharge lamp. SOLUTION: A line across the drain sources of a high-frequency power supply 1 is connected to the first matching circuit 2a, and this first matching circuit 2a is connected to the second matching circuit 2b via a coaxial cable 5. The second matching circuit 2b is connected to an exciting coil 4 and this coil 4 is wound, for example, around an electric discharge lamp 3. In this case, the characteristic impedance and the delay time of the coaxial cable 5 are selected so that the internal loss of the high-frequency power supply becomes approximately constant and/or power transmitted to a load becomes equal to or less than the preset value, when the constant of a circuit element to form a close circuit including the load but not the high-frequency power supply fluctuates, regarding circuit elements forming the matching circuits 2a and 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency device for lighting an electrodeless discharge lamp, for example, by arranging an excitation coil near an electrodeless discharge lamp and applying a high-frequency power to the excitation coil to generate a magnetic field. The present invention relates to a power supply device, an electrodeless discharge lamp lighting device, a lighting device, and a photochemical treatment device.

[0002]

2. Description of the Related Art FIG. 7A shows a conventional electrodeless discharge lamp lighting device.
A high-frequency power of 88.45 V is generated and applied to the exciting coil 4 via the matching circuit 2 to turn on the electrodeless high-pressure discharge lamp 3 having a rating of, for example, 300 W. As the high frequency power supply 1, transistors Q1 and Q2 as shown in FIG. 8A, a coil L and a transistor Q1 and a capacitor C as shown in FIG. 8B, and a transistor Q1 as shown in FIG. To Q4 to generate high-frequency power by the switching operation of the transistor Q. Since such a high-frequency power supply 1 has a smaller loss than the output power, it can be regarded as a constant voltage source as shown in FIG. 7B, and the phase of the output current lags behind the output voltage of the high-frequency power supply 1. To be configured.

The equivalent circuit of the exciting coil 4 can be represented by an inductance Lc and a resistance Rc. The equivalent circuit of the discharge lamp 3 in a ring discharge state is represented by a discharge resistor Ra, an inductance Lc of the exciting coil 4 and a coupling coefficient k. And can be represented by the inductance La magnetically coupled. The constant is, for example, Rc = 4 kΩ Lc = 165 nH ± 5% La = 11.74 nH Ra = 2.021Ω (= α) k = 0.380.

FIGS. 9A to 9C show specific examples of the matching circuit 2. FIG. FIG. 9A shows a series capacitor Cs1 (= 2
33.5 pF) and a parallel capacitor Cp2 (= 679.9 pF)
FIG. 9B shows a series capacitor Cs1 (= 183 pF) and an inductance Ls2.
(= 162.9 nH) and the parallel capacitor Cp2 (= 67
9.9 pF).
FIG. 9C shows a series capacitor Cs1 (= 100 pF) and an inductance Ls2 (= 1.503 μH), a parallel capacitor Cp3 (= 184.3 pF), a series inductance Ls4 (= 747.3 nH) and a parallel capacitor Cp5.
(= 1041 pF). The input impedance | Z | / θ of the matching circuit 2 is 21.3Ω / 30 °.

[0005]

However, when such a matching circuit 2 is provided, as shown in FIG. 10, the inductance Lc (standardized inductance L) of the exciting coil 4 is increased.
c-nml) fluctuates due to manufacturing variations and aging, impedance mismatches occur and the lamp power P
relative direct illuminance in proportion to lmp (1.0 for 300W
0)) greatly deviates from the rated value.

FIG. 10 shows a normalized inductance Lc-nm.
It shows that the relative direct illuminance becomes smaller than the rated value when l increases, and the relative direct illuminance becomes larger than the rated value when the normalized inductance Lc-nml decreases. Further, in the latter case, the matching circuits shown in FIGS. 9A and 9B are more remarkable than those in FIG. 9C.

Here, the surface temperature of the discharge lamp 3 is several hundred degrees.
C or higher, and the junction temperature of the semiconductor is 1
Since the temperature must be lower than 50 ° C., the switching transistor and the like must be protected from high temperatures. Therefore, Japanese Utility Model Laid-Open No. 5-53018 proposes a method in which an oscillation circuit and an amplification circuit are unitized, an impedance matching circuit, an excitation coil, and a lamp are unitized and separated, and each unit is connected via a coaxial cable. Have been. However, in this method, the units are simply connected by a coaxial cable of an arbitrary length. If the inductance of the exciting coil changes, the impedance does not match, and the lamp power greatly deviates from the rated value. There is.

Further, in this type of magnetic induction type electrodeless discharge lamp lighting device, since power is transmitted to the discharge through a magnetic flux formed by a current flowing through the exciting coil 4, a comparison is required to maintain the discharge. Requires a large coil current. Normally, this large coil current is generated by a closed circuit including the exciting coil 4 and not including the high-frequency power supply 1. In FIG. 7, the matching circuit 2, the inductance Lc of the exciting coil 4, and the resistance Rc
Formed by the resonance action of a closed circuit constituted by The reason for utilizing the resonance action of the closed circuit including the exciting coil 4 is as follows.
The reason why a large current for forming a magnetic flux is caused to flow through the excitation coil 4, and the reason for utilizing the resonance action of a closed circuit that does not include the high-frequency power supply 1 is to prevent a large current from passing through the high-frequency power supply 1. This is for suppressing the internal loss of the high frequency power supply 1.

However, even if the resonance effect of the closed circuit that does not include the high-frequency power supply 1 is used, for example, if the inductance Lc of the exciting coil 4 at no load fluctuates,
Since the operating point of the high-frequency power supply 1 approaches or moves away from the resonance point, the internal loss of the high-frequency power supply 1 due to the fluctuation of the inductance Lc and the like particularly in the power supply 1 that generates a high frequency of, for example, 1 MHz or more by switching. There is a problem that it increases rapidly.

Further, since the internal loss of the high-frequency power supply 1 is larger than the design value, the input power to the discharge lamp 3 is limited as a result. There is a problem that it becomes dark. Similarly, the values of the elements (C and L of the matching circuit 2 shown in FIG. 9) connected to a tree for forming a closed circuit that does not include the high-frequency power supply 1 but includes the exciting coil 4 may fluctuate with high sensitivity. is there. Even when the electrodeless discharge lamp 1 is not used as a load, a reactive load (Q
A similar problem occurs with respect to a load having a high value.

Therefore, the inductance Lc of the exciting coil 4 when no load is applied is liable to fluctuate due to the thermal shock of radiation, heat transfer, and self-heating of the discharge lamp 1, and the constant of the element resonating with the exciting coil 4 is also constant. Since it is difficult to perform initial management and time-dependent management, it is necessary to solve such problems.

As a conventional example of this kind, there is proposed a method of providing an impedance inverting circuit when the internal loss of a high-frequency power supply is smaller than the power consumption of a load as shown in Japanese Patent Publication No. Hei 5-38436. ing. However, this method has a problem that when the discharge impedance increases (when the lamp power decreases), the supply power of the high-frequency power supply increases due to the impedance inverting circuit, and the internal loss of the high-frequency power supply increases. Another method is to detect the high-frequency current flowing through the exciting coil and feed it back to actively suppress the internal loss of high-frequency power. In this case, a special active circuit is required. This necessitates a complicated circuit configuration.

In view of the above-mentioned conventional problems, the present invention provides a high-frequency power supply device capable of obtaining a lamp power of a rated value even if the inductance and the like of an exciting coil fluctuate due to variations at the time of manufacture and changes over time. An object of the present invention is to provide an electric lamp lighting device, a lighting device, and a photochemical treatment device.

[0014]

According to the first aspect of the present invention, to achieve the above object, an exciting coil is arranged near an electrodeless discharge lamp, and a high-frequency power is applied to the exciting coil to generate a magnetic field. In the electrodeless discharge lamp lighting device for lighting the electrodeless discharge lamp, a high frequency power supply for generating high frequency power for maintaining lighting of the electrodeless discharge lamp and a first impedance matching connected to the high frequency power supply A circuit, a second impedance matching circuit connected to the exciting coil, and a transmission line connected between the first and second impedance matching circuits, and at least the first and second impedances. The length of the transmission line is set such that the output of the electrodeless discharge lamp is substantially constant according to the characteristics of the matching circuit. With the above configuration, the length of the transmission line is set such that the output of the electrodeless discharge lamp is substantially constant according to at least the characteristics of the first and second impedance matching circuits.

According to a second aspect of the present invention, the first and second impedance matching circuits of the first aspect are at least T-shaped.
It is characterized in that there are two combinations of an L-shaped and a π-shaped impedance matching circuit, and the length of the transmission line is different depending on the combination. With the above configuration, the optimal length of the transmission line is set according to the configuration of the first and second impedance matching circuits.

According to a third aspect of the present invention, when the characteristic of the exciting coil fluctuates in the first or second aspect of the invention,
The length of the transmission line is set such that the output of the electrodeless discharge lamp is substantially constant. With the above configuration, the length of the transmission line is set such that the output to the electrodeless discharge lamp becomes substantially constant even when the characteristics of the exciting coil fluctuate.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, when the characteristics other than the excitation coil fluctuate, the length of the transmission line is adjusted so that the output of the electrodeless discharge lamp becomes substantially constant. It is characterized by being set. With the above configuration, the length of the transmission line is set such that the output to the electrodeless discharge lamp becomes substantially constant even when characteristics other than the excitation coil fluctuate.

According to a fifth aspect of the present invention, in the first to fourth aspects, the transmission line is a coaxial cable. With the above configuration, high-frequency power is output to the electrodeless discharge lamp via a coaxial cable having an optimal length.

According to a sixth aspect of the present invention, in the lighting apparatus, the electrodeless discharge lamp, the exciting coil and the second impedance matching circuit according to the first to fifth aspects are provided in a lighting fixture main body. A power supply and a first impedance matching circuit are provided in a separate lighting fixture, and the lighting fixture main body and the lighting fixture separate body are connected via the transmission line according to claims 1 to 5. According to the above configuration, the high-frequency power from the separate lighting fixture is output to the lighting fixture main body via the transmission line having the optimum length.

According to a seventh aspect of the present invention, there is provided a high-frequency power supply for outputting high-frequency power of 1 MHz or more by a switching operation of a semiconductor switch, and a matching circuit connected between the high-frequency power supply and a load. Among the constituent circuit elements, the matching circuit is configured such that the internal loss of the high-frequency power supply becomes substantially constant when the constant of a circuit element that configures a closed circuit that does not include the high-frequency power supply and includes the load fluctuates. A high-frequency power supply device characterized in that constants of circuit elements to be operated are selected. According to the above configuration, since the internal loss of the high-frequency power supply is substantially constant, it is possible to prevent the operating point of the high-frequency power supply from approaching or leaving the resonance point. As a result, the radiator of the high-frequency power supply can be reduced in size, and when applied to an electrodeless discharge lamp, inexpensiveness, long life, and high reliability can be realized.

The invention according to claim 8 includes a high-frequency power supply that outputs high-frequency power of 1 MHz or more by a switching operation of a semiconductor switch, and a matching circuit connected between the high-frequency power supply and a load. Among the constituent circuit elements, the matching circuit is configured so that the power transmitted to the load becomes equal to or less than a set value when the constant of the circuit element forming the closed circuit including the load does not include the high-frequency power supply. A high-frequency power supply device wherein constants of circuit elements to be configured are selected. With the above configuration, since the power transmitted to the load is equal to or less than the set value, it is possible to prevent the operating point of the high frequency power supply from approaching or leaving the resonance point as a result. As a result, the radiator of the high-frequency power supply can be reduced in size, and when applied to an electrodeless discharge lamp, inexpensiveness, long life, and high reliability can be realized.

According to a ninth aspect of the present invention, there is provided a high frequency power supply for outputting a high frequency power of 1 MHz or more by a switching operation of a semiconductor switch, and a matching circuit connected between the high frequency power supply and a load. When the constant of the circuit element constituting the closed circuit including the load does not include the high-frequency power supply among the constituent circuit elements, the internal loss of the high-frequency power supply is transmitted to the load so as to be substantially constant. A constant of a circuit element constituting the matching circuit is selected such that the power of the matching circuit is equal to or less than a set value. According to the above configuration, since the internal loss of the high-frequency power supply is substantially constant and the power transmitted to the load is equal to or less than the set value, it is possible to prevent the operating point of the high-frequency power supply from approaching or leaving the resonance point. As a result, the radiator of the high-frequency power supply can be reduced in size, and when applied to an electrodeless discharge lamp, inexpensiveness, long life, and high reliability can be realized.

The invention according to claim 10 is the invention according to claims 7 to 9
Wherein the matching circuit includes a first impedance matching circuit connected to the high-frequency power supply, a second impedance matching circuit connected to the load, and the first and second impedance matching circuits. And a transmission line connected between the two impedance matching circuits, and among the circuit elements constituting the first and second impedance matching circuits, a closed circuit including the load without including the high-frequency power source is configured. The characteristic impedance of the transmission line and the delay are adjusted so that the internal loss of the high-frequency power supply becomes substantially constant and / or the power transmitted to the load becomes equal to or less than a set value when the constant of the circuit element to be changed fluctuates. The time is selected. With the above configuration, the characteristic impedance and the delay time of the transmission line can be selected by selecting the length of the transmission line, so that the operating point of the high-frequency power supply can be prevented from approaching or leaving the resonance point with a simple configuration. can do.

The invention according to claim 11 has an electrodeless discharge lamp, and an exciting coil wound near the electrodeless discharge lamp, wherein the exciting coil during lighting of the electrodeless discharge lamp has An electrodeless discharge lamp lighting device comprising the load according to any one of Items 8 to 10. The above configuration prevents the operating point of the high-frequency power supply from approaching or moving away from the resonance point even when the inductance of the excitation coil at no load fluctuates due to radiation from the lamp, heat transfer, and thermal shock due to self-heating. Can be.

According to a twelfth aspect of the present invention, the electrodeless discharge lamp emits ultraviolet light and is immersed in a processing object having a higher dielectric constant than air, and the processing object is further embodied in the eleventh embodiment.
A photochemical treatment apparatus characterized in that the load is the described load. With the above configuration, even when the electrodeless discharge lamp is arranged in or near the processing target having a dielectric constant much higher than that of air, the operating point of the high-frequency power supply can be prevented from approaching or leaving the resonance point. it can.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of an electrodeless discharge lamp lighting device according to the present invention, and FIGS.
(D) is a circuit diagram showing a specific example of the first and second matching circuits in FIG. 1, and FIG. 3 is a normalized inductance-relative when the first and second matching circuits in FIG. 2 (a) are used. FIG. 4 is a graph showing the characteristic of the illuminance directly below, FIG. 4 is a graph showing the characteristic of normalized inductance-relative illuminance directly below when the first and second matching circuits shown in FIG. 2B are used, and FIG. 6) is a graph showing characteristics of normalized inductance-relative direct illuminance when the first and second matching circuits are used, and FIG. 6 is a graph showing the case where the first and second matching circuits of FIG. It is a graph which shows the characteristic of normalized inductance-relative illuminance directly under.

The high-frequency power supply 1 shown in FIG. 1 is, for example, a preamplifier 1a and transistors (MOS-FETs) Q1, Q
2 and the alternating current output from the preamplifier 1a is applied to the gates of the transistors Q1 and Q2. Transistor Q2
Is applied with a voltage VDD (= 200 V), the source of the transistor Q2 is connected to the drain of the transistor Q1, and the source of the transistor Q1 is grounded. The transistors Q1 and Q2 are switched by the preamplifier 1a, and a high frequency of 13.56 MHz and 88.45 V is generated between the drain and the source of the transistor Q1.

A first matching circuit (cable input matching circuit) 2a is connected between the drain and source of the transistor Q1, and the first matching circuit 2a is connected via a coaxial cable 5 to the second matching circuit 2a.
(A cable output matching circuit) 2b. The second matching circuit 2b is connected to the exciting coil 4,
The excitation coil 4 is arranged near the discharge lamp 3 and is configured to be wound around, for example, the high-pressure electrodeless discharge lamp 3. The equivalent circuit of the exciting coil 4 can be represented by an inductance Lc and a resistance Rc. The equivalent circuit of the discharge lamp 3 in a ring discharge state is magnetically coupled by a discharge resistance Ra, the inductance Lc of the exciting coil 4 and a coupling coefficient k. It can be represented by the calculated inductance La. These constants used were the same as in the conventional example.

The input impedance Zin of the first matching circuit 2a is 17.5 Ω / 35 ° (input voltage Vin = 8
The power transmission from the first matching circuit 2a to the second matching circuit 2b is performed via the coaxial cable 5 having a characteristic impedance Z0 = 50 [Ω] and a delay time td [nsec]. Done. In the present invention, the first
FIG. 2A shows the matching circuit 2a and the second matching circuit 2b of FIG.
An experiment was performed using the combinations shown in FIGS.

That is, in the example shown in FIG.
Of the series capacitor Cs11 (= 100p
F) and a modified L-type (L'-type) composed of an inductance Ls12 (1.786 μH) and a parallel capacitor Cp13 (= 306.5 pF), and the second matching circuit 2b is a series capacitor Cs21 (= 127.6 pF). ) And a parallel capacitor Cp22 (= 757.9 pF) (hereinafter referred to as L'-L type).

The first matching circuit 2a shown in FIG. 2B is the same (L 'type) as that of FIG. 2A, but the second matching circuit 2b has a parallel inductance Lp21 (= 1.229 .mu.m).
H), π composed of a series capacitor Cs22 (= 112.1 pF) and a parallel capacitor Cp23 (= 744.2 pF).
(Hereinafter referred to as L′-π shape). FIG. 2 (c)
The first matching circuit 2a shown in FIG.
(= 594.9 pH) and the parallel inductance Lp12
(356.7 nH) and the series capacitor Cs13 (= 386
pF), and the second matching circuit 2b is the same (L-type) as in FIG. 2A (hereinafter referred to as TL).
form). The first matching circuit 2a shown in FIG.
The same (T type) as in the case of FIG.
b is the same (π type) as in FIG. 3B (hereinafter, T
-Π type).

The inductance Lc of the exciting coil 4 is intentionally changed by using the first and second matching circuits 2a and 2b of such a combination, and the delay time td is changed by changing the length of the coaxial cable 5. As a result, it was found that the optimum line length of the coaxial cable 5 was different for each combination of the matching circuits 2a and 2b. In the L'-L type shown in FIG. 2A, the most desirable characteristic can be obtained when td = 32.9 [nsec] as shown in FIG. 3, and td = 14.7.
In the case of [nsec], slightly desirable characteristics could be obtained. When td = 6.15 [nsec] and td = 0 [nsec], the lamp power Plmp greatly deviated from the rated value (300 W).

That is, when td = 0 [nsec] (no cable) or when the cable length corresponds to td = 6.15 [nsec], the inductance L of the exciting coil 4 is reduced.
c is the design center (Lc-nml =
1.000), the relative illuminance directly below the lamp power, which is proportional to the lamp power Plmp, fluctuated greatly with a slight fluctuation.
On the other hand, when the cable length corresponds to td = 32.9 [nsec], the inductance L of the exciting coil 4 is reduced.
Even if c fluctuated from the design value, the relative illuminance directly under the lamp power proportional to the lamp power Plmp could be kept constant. Also, td =
In the case of a cable length corresponding to 14.7 [nsec], rated power can be supplied at the design center (Lc-nml = 1.000), and this rated power is the maximum power.

In the L′-π type shown in FIG.
As shown in FIG. 4, the most desirable characteristic can be obtained when td = 7.89 [nsec], and td = 20.5 [nse
In the case of c), somewhat desirable characteristics could be obtained.
When td = 6.15 [nsec] and td = 0 [nsec], the relative direct illuminance (1.00 at 300 W), which is proportional to the lamp power Plmp, greatly deviated from the rated value.

In the TL type shown in FIG. 2C, the most desirable characteristics can be obtained when td = 25.2 [nsec] as shown in FIG. 5, and td = 7.00 [ nsec]
In the case of the above, slightly desirable characteristics could be obtained. td
= 30.7 [nsec] and td = 0 [nsec], the relative direct illuminance in proportion to the lamp power Plmp greatly deviated from the rated value.

In the T-π type shown in FIG. 2D, the most desirable characteristics can be obtained when td = 31.1 [nsec] as shown in FIG. 6, and td = 12.8 [ nsec]
In the case of the above, slightly desirable characteristics could be obtained. td
= 24.6 [nsec] and td = 0 [nsec], the relative direct illuminance in proportion to the lamp power Plmp greatly deviated from the rated value.

Therefore, according to the present invention, the cable 5
Is set to an optimum length in accordance with the combination of the first and second matching circuits 2a and 2b, so that the lamp power of the rated value is obtained even if the inductance Lc of the exciting coil 4 fluctuates due to variations at the time of manufacture and aging. Can be obtained. Furthermore,
When paying attention to a change in characteristics other than the inductance Lc, the optimum length of the cable 5 with respect to a change in the Cp value is:
It is equal to the cable length suitable for Lc fluctuation.

In the configuration in which the first and second matching circuits 2a and 2b are connected via the cable 5, the inductance Lc of the exciting coil 4 is intentionally increased by 2.5% from the design value.
If the lamp power Plamp at that time is within ± 10% of the design value (nameplate value), it can be determined that the cable length at that time is optimal.

FIG. 11 shows the configuration of a lighting device having the electrodeless discharge lamp lighting device of the present invention. This lighting device is separated into a lighting fixture main body 21 and a lighting fixture separate body 30, and the lighting fixture main body 21 and the lighting fixture separate body 30 are connected via a coaxial cable 5. In this example, a starting capillary is attached to the discharge lamp 25. Lighting fixture body 21
Is divided into two parts by a lamp chamber 22 and a component storage chamber 23. Inside the lamp chamber 22, a discharge lamp 25, a reflecting mirror 26 for reflecting the light of the discharge lamp 25, and a prism for refracting the light reflected by the reflecting mirror 26. And a prism cover 24.

A circuit board 27 for continuously lighting the discharge lamp 25 and a starting circuit component 28 for driving the starting thin tube to turn on the discharge lamp 25 are provided in the component accommodating chamber 23. The circuit board 27 is provided with the second matching circuit 2b shown in FIG. The circuit board 27 is connected to a heat pipe 29 provided outside the component housing chamber 23. The circuit board 31 is provided on the lighting fixture separate body 30, and the high-frequency power supply 1 and the first matching circuit 2a shown in FIG. 1 are provided on the circuit board 31. The second matching circuit 2b on the lighting fixture body 20 side and the first matching circuit 2a on the lighting fixture separate body 30 side are connected via the coaxial cable 5.

Next, a second embodiment will be described with reference to FIGS. FIG. 12 is a block diagram showing a high-frequency power supply device, an electrodeless discharge lamp lighting device, and a lighting device according to the second embodiment. FIGS. 13 to 15 are graphs showing characteristics of normalized Cp value-relative power loss, and FIGS. FIG. 18 to FIG. 18 are graphs showing characteristics of normalized Cp value-relative direct illuminance. In the configuration shown in FIG. 12, L'-L type matching circuits 2a and 2b shown in FIG. 2A are used, and the first matching circuit 2a has a series capacitor Cs11 (= 279.6 pF) and an inductance Ls12 ( 824.3 nH) and parallel capacitor C
It is composed of L 'type consisting of p13 (= 476.2 pF),
The second matching circuit 2b includes a series capacitor Cs21 (= 12
1.0pF) and the parallel capacitor Cp22 (= 780.1p
F) and the L-shape. A coaxial cable 5 is connected between the matching circuits 2a and 2b.
The inductance Lc of the exciting coil 4 is 15
The one with 9.0 nH and the resistance Rc of 3.34 kΩ was used.

In such a circuit, as shown in FIG. 13, first, (3/16) λ and (4
/ 16) A parallel capacitor Cp22 of 780.1 pF (hereinafter, referred to as “parameter”) connected in parallel to the exciting coil 4 using two types of λ
The internal loss of the high frequency power supply 1 was measured by changing Cp). When the coaxial cable 5 of (3/16) λ was used, the internal loss of the high-frequency power supply 1 was substantially constant although slightly fluctuated as shown by the mark ○. In contrast, (4/1
6) When the coaxial cable 5 of λ is used, the internal loss increases as the Cp value decreases, as indicated by the crosses.
Normalized Cp value = 1.02, ie, Cp = 780.1 pF
When × 1.02, the internal loss of the high-frequency power supply 1 is the design value =
It was 1.00. When the normalized Cp value is 0.99 or less, the internal loss of the high frequency power supply 1 is not shown, but this is because the lamp 3 has extinguished.

FIG. 14 shows a coaxial cable 5 of (1/16) λ.
When the normalized Cp value is 1.00, the internal loss of the high-frequency power supply 1 becomes the design value = 1.00, but when the Cp value is increased, the internal loss increases. When the chemical Cp value was 1.1 or more, the lamp 3 went out. FIG. 15 shows a case where the coaxial cable 5 of (2/16) λ is used. Compared with FIG. 14, the slope of the internal loss of the high-frequency power supply 1 is gentle, and the normalized Cp value =
When 1.00, the internal loss of the high-frequency power supply 1 is the design value =
Although it was 1.00, the internal loss increased when the Cp value was increased, and the lamp 3 went out when the normalized Cp value was 1.1 or more.

Also, as shown in FIG. 16, two types of coaxial cable 5 (3/16) λ and (4/16) λ were used, and the illuminance immediately below the lamp 3 was measured by changing the Cp value. . When the coaxial cable 5 of (3/16) λ is used, the illuminance directly below becomes the maximum when the normalized Cp value is 1.00, that is, Cp = 780.1 pF, and the Cp is shifted in ± When it increased or decreased, the illuminance immediately below decreased. On the other hand, when the coaxial cable 5 of (4/16) λ is used, it looks the same as the case of (3/16) λ, but the normalized Cp value is 0.99 as shown by the mark x. Below, lamp 3 went out.

FIG. 17 shows a coaxial cable 5 of (1/16) λ.
When the normalized Cp value is 1.00, the illuminance directly underneath is maximum, but when the Cp value decreases, the illuminance directly underneath decreases. FIG. 18 shows a case in which the coaxial cable 5 of (2/16) λ is used. Compared with FIG. 17, the inclination of the illuminance immediately below is gentle, and the normalized Cp value = 1.
When 00, the internal loss of the high-frequency power supply 1 is designed value = 1.0
Although it was 0, the illuminance immediately below decreased as the Cp value decreased.

Therefore, when the matching circuits 2a and 2b having the configuration shown in FIG. 12 and the coaxial cable 5 are used, the length of the coaxial cable 5 is (1/16) λ, (2/16) λ,
If the Cp value fluctuates at (4/16) λ, the internal loss of the high-frequency power supply 1 changes, and the illuminance immediately below decreases.
/ 16) When the coaxial cable 5 of λ was used, it was found that the internal loss of the high-frequency power supply 1 of the high-frequency power supply 1 became substantially constant and the lighting range could be widened even if the Cp value fluctuated.

FIG. 19A shows a third embodiment in which L'-π type matching circuits 2a and 2b shown in FIG. 2B are used, and the first matching circuit 2a is a series capacitor Cs11.
(= 100 pF) and the inductance Ls12 (1.76)
0 μH) and the parallel capacitor Cp13 (= 370.8 pF)
The second matching circuit 2b comprises a parallel inductance Lp21 (= 1.229 .mu.H) and a .pi.-type consisting of a series capacitor Cs22 (= 12.1 pF) and a parallel capacitor Cp23 (= 744.2 pF). It is composed of

FIG. 20 shows the illuminance immediately below the lamp when the inductance Lc of the exciting coil 4 is changed using six types of coaxial cables 5 having different lengths as described below. □: td = 0 [nsec] Δ: td = 6.15 [nsec] ×: td = 9.22 [nsec] *: td = 12.3 [nsec] ○: td = 15.4 [Nsec] + mark: td = 18.4 [nsec] (1/4 wavelength) According to FIG. 20, when the delay time td = 0 of the coaxial cable 5, ie, without using the coaxial cable 5, the matching circuit 2
In the configuration where a and b are directly connected, the illuminance immediately below the lamp does not change even if the inductance Lc of the exciting coil 4 changes, and the delay time td of the coaxial cable 5 is 18.4 [nsec].
In the configuration described above, when the variation of the inductance Lc of the exciting coil 4 fluctuates in the ± direction, the illuminance immediately below the lamp is reduced.

The length L of the coaxial cable 5 is L = k.c.Td, where k is a constant of the coaxial cable, c is the speed of light, and Td is a delay time. A feeder line or a parallel line may be used in place of the coaxial cable 5, and FIG.
As shown in (b), the first parallel inductance can be replaced by a π-type circuit composed of a series capacitor and a second parallel inductance. Note that the above embodiment is merely an example, and (1/16) λ, (2/16) λ,
(4/16) λ, etc., in some cases, and can be selected in relation to other conditions.

Further, according to the present invention, the UV
Hg for emitting light, Ar, Kr, Xe and N
e, enclosing at least one of them, disposing the lamp 3 in a pipe through which a fluid such as water or an organic solvent flows, and exposing the fluid to UV light to perform a treatment such as sterilization or polymerization. Can be. In this case, for example, the dielectric constant of water is much higher than that of air, and the capacitance becomes an equivalent circuit connected in parallel with the exciting coil 4. Therefore, taking into account this effect, the coaxial cable 5 and the matching circuits 2a and 2b are considered. A constant is selected.

[0051]

As described above, according to the first aspect of the present invention, the length of the transmission line is set so that the output of the electrodeless discharge lamp becomes substantially constant even if the characteristics of the exciting coil fluctuate. Therefore, even if the inductance and the like of the exciting coil fluctuate due to variations at the time of manufacture and changes over time, it is possible to obtain a lamp power of a rated value. According to the second aspect of the present invention, since the length of the transmission line is set according to the configuration of the first and second impedance matching circuits, regardless of the configuration of the first and second impedance matching circuits. Even if the inductance of the exciting coil fluctuates due to manufacturing variations or changes over time, it is possible to obtain a rated lamp power. According to the third aspect of the present invention, when the characteristics of the exciting coil fluctuate, the length of the transmission line is made variable so that the output of the electrodeless discharge lamp becomes substantially constant. Even if it fluctuates due to variations in time or changes over time, it is possible to obtain a rated value of lamp power. According to the invention of claim 4, when the characteristics other than the excitation coil fluctuate, the length of the transmission line is varied so that the output of the electrodeless discharge lamp becomes substantially constant. Can be obtained even if the characteristics fluctuate due to manufacturing variations or changes over time. Claim 5
According to the invention described above, since the length of the coaxial cable is made variable, a lamp power having a rated value can be obtained even if the inductance of the exciting coil fluctuates due to variations at the time of manufacture or aging. According to the invention described in claim 6, it is possible to realize a lighting device that outputs a lamp power of a rated value. According to the seventh aspect of the present invention, the internal loss of the high-frequency power supply is substantially constant when the constant of a circuit element that does not include the high-frequency power supply and that forms a closed circuit that includes a load among the circuit elements that configure the matching circuit varies. Since the constants of the circuit elements constituting the matching circuit are selected such that the following equation is satisfied, it is possible to prevent the operating point of the high-frequency power supply from approaching or leaving the resonance point. As a result, the radiator of the high-frequency power supply can be reduced in size, and when applied to an electrodeless discharge lamp, inexpensiveness, long life, and high reliability can be realized. According to the eighth aspect of the present invention, the power transmitted to the load when the constant of the circuit element forming the closed circuit including the load without including the high-frequency power supply among the circuit elements forming the matching circuit varies. Since the constants of the circuit elements forming the matching circuit are selected so as to be equal to or less than the value, it is possible to prevent the operating point of the high-frequency power supply from approaching or leaving the resonance point. As a result, the radiator of the high-frequency power supply can be reduced in size, and when applied to an electrodeless discharge lamp, inexpensiveness, long life, and high reliability can be realized. According to the ninth aspect of the present invention, the internal loss of the high-frequency power supply is substantially constant when the constant of a circuit element that does not include the high-frequency power supply and that forms a closed circuit that includes a load among the circuit elements that configure the matching circuit varies. And the constants of the circuit elements constituting the matching circuit are selected so that the power transmitted to the load is equal to or less than the set value, so that the operating point of the high-frequency power source approaches or moves away from the resonance point. Can be prevented. As a result, the radiator of the high-frequency power supply can be reduced in size, and when applied to an electrodeless discharge lamp, inexpensiveness, long life, and high reliability can be realized. According to the tenth aspect of the present invention, the characteristic impedance and the delay time of the transmission line can be selected by selecting the length of the transmission line, so that the operating point of the high-frequency power source approaches the resonance point with a simple configuration. And separation can be prevented. According to the eleventh aspect of the present invention, the operating point of the high-frequency power supply approaches or moves away from the resonance point even if the inductance of the excitation coil at no load varies due to radiation from the lamp, heat transfer, and thermal shock due to self-heating. Can be prevented. According to the twelfth aspect of the invention, even when the electrodeless discharge lamp is immersed in a processing target having a dielectric constant much higher than that of air, the operating point of the high-frequency power supply is prevented from approaching or moving away from the resonance point. can do.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of an electrodeless discharge lamp lighting device according to the present invention.

FIG. 2 is a circuit diagram showing a specific example of first and second matching circuits in FIG. 1;

FIG. 3 is a graph showing characteristics of normalized inductance-relative direct illuminance when the first and second matching circuits of FIG. 2A are used.

FIG. 4 is a graph showing characteristics of normalized inductance-relative direct illuminance when the first and second matching circuits of FIG. 2B are used.

FIG. 5 is a graph showing a characteristic of normalized inductance-relative direct illuminance when the first and second matching circuits of FIG. 2C are used.

FIG. 6 is a graph showing characteristics of normalized inductance-relative direct illuminance when the first and second matching circuits of FIG. 2 (c) are used.

FIG. 7 is a circuit diagram showing a conventional electrodeless discharge lamp lighting device.

8 is a circuit diagram showing a specific example of the high-frequency power supply of FIG.

FIG. 9 is a circuit diagram showing a specific example of the matching circuit of FIG. 7;

10 is a graph showing a characteristic of normalized inductance-relative direct illuminance when the matching circuit of FIG. 9 is used.

FIG. 11 is a configuration diagram showing a lighting device having the electrodeless discharge lamp lighting device of the present invention.

FIG. 12 is a block diagram illustrating a high-frequency power supply device, an electrodeless discharge lamp lighting device, and a lighting device according to a second embodiment.

FIG. 13 is a graph showing a characteristic of a normalized Cp value-relative power supply loss in the second embodiment.

FIG. 14 is a graph showing a characteristic of a normalized Cp value-relative power supply loss in the second embodiment.

FIG. 15 is a graph showing a characteristic of a normalized Cp value-relative power supply loss in the second embodiment.

FIG. 16 is a graph showing a characteristic of normalized Cp value-relative direct illuminance in the second embodiment.

FIG. 17 is a graph showing a characteristic of normalized Cp value-relative direct illuminance in the second embodiment.

FIG. 18 is a graph showing characteristics of normalized Cp value-relative direct illuminance in the second embodiment.

FIG. 19 is a block diagram showing a high-frequency power supply device, an electrodeless discharge lamp lighting device, and a lighting device according to the third embodiment and its modifications.

FIG. 20 is a graph showing a characteristic of normalized Lc value-relative direct illuminance in the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High frequency power supply 2a 1st matching circuit (cable input matching circuit) 2b 2nd matching circuit (cable output matching circuit) 3 discharge lamp 4 excitation coil 5 coaxial cable 21 lighting fixture main body 30 lighting fixture separate body

Claims (12)

[Claims] 1. An electrodeless discharge lamp lighting device for arranging an excitation coil near an electrodeless discharge lamp and applying a high frequency power to the excitation coil to generate a magnetic field, thereby lighting the electrodeless discharge lamp. A high-frequency power supply for generating high-frequency power for maintaining lighting of the electrode discharge lamp; a first impedance matching circuit connected to the high-frequency power supply; a second impedance matching circuit connected to the exciting coil; A transmission line connected between the first and second impedance matching circuits, wherein the output of the electrodeless discharge lamp is substantially constant according to at least the characteristics of the first and second impedance matching circuits. An electrodeless discharge lamp lighting device, wherein the length of the transmission line is set to be as follows. 2. The first and second impedance matching circuits are at least two combinations of T-type, L-type, and π-type impedance matching circuits, and the length of the transmission line differs according to the combination. The lighting device for an electrodeless discharge lamp according to claim 1, wherein: 3. The length of the transmission line is set such that the output of the electrodeless discharge lamp becomes substantially constant when the characteristics of the exciting coil fluctuate. 2. The electrodeless discharge lamp lighting device according to item 2. 4. The length of the transmission line is set so that the output of the electrodeless discharge lamp becomes substantially constant when characteristics other than the excitation coil fluctuate. The electrodeless discharge lamp lighting device according to any one of claims 1 to 3. 5. The lighting device for an electrodeless discharge lamp according to claim 1, wherein the transmission line is a coaxial cable. 6. An electrodeless discharge lamp according to claim 1, wherein:
The exciting coil and the second impedance matching circuit are provided in the lighting fixture main body, and the high-frequency power supply and the first impedance matching circuit according to claim 1 are provided in the lighting fixture separate body.
A lighting device in which a lighting fixture main body and a separate lighting fixture are connected via the transmission line according to claim 1. 7. A circuit element comprising: a high-frequency power supply that outputs high-frequency power of 1 MHz or more by a switching operation of a semiconductor switch; and a matching circuit connected between the high-frequency power supply and a load. The constants of the circuit elements forming the matching circuit are adjusted so that the internal loss of the high-frequency power supply becomes substantially constant when the constants of the circuit elements forming the closed circuit including the load do not include the high-frequency power supply. A high-frequency power supply device, which is selected. 8. A circuit element comprising: a high-frequency power supply that outputs high-frequency power of 1 MHz or more by a switching operation of a semiconductor switch; and a matching circuit connected between the high-frequency power supply and a load. The constants of the circuit elements constituting the matching circuit are set so that the power transmitted to the load becomes equal to or less than a set value when the constants of the circuit elements constituting the closed circuit including the load do not include the high-frequency power supply. Is selected. 9. A circuit element comprising: a high-frequency power supply that outputs high-frequency power of 1 MHz or more by a switching operation of a semiconductor switch; and a matching circuit connected between the high-frequency power supply and a load. When the constants of the circuit elements that form the closed circuit that does not include the high-frequency power supply but include the load fluctuate, the internal loss of the high-frequency power supply becomes substantially constant and the power transmitted to the load is equal to or less than a set value. Wherein the constants of the circuit elements constituting the matching circuit are selected such that: 10. The first impedance matching circuit connected to the high frequency power supply, the second impedance matching circuit connected to the load, and the first and second impedance matching circuits. And a transmission line connected between the first and second impedance matching circuits. Of the circuit elements constituting the first and second impedance matching circuits, a constant of a circuit element constituting a closed circuit including the load without including the high-frequency power supply is The characteristic impedance and the delay time of the transmission line are selected so that the internal loss of the high-frequency power supply becomes substantially constant and / or the power transmitted to the load becomes equal to or less than a set value when the power supply fluctuates. The high-frequency power supply device according to any one of claims 7 to 9, wherein: 11. An electrodeless discharge lamp comprising: an electrodeless discharge lamp; and an exciting coil wound near the electrodeless discharge lamp, wherein the exciting coil is turned on when the electrodeless discharge lamp is turned on. An electrodeless discharge lamp lighting device, characterized in that the load is the load described in (1). 12. The electrodeless discharge lamp emits ultraviolet light and is disposed in or near a processing object having a higher dielectric constant than air, and the processing object is a load according to claim 11. Photochemical processing equipment.