JPH0896766A - Dielectric barrier discharge device - Google Patents

Abstract

PURPOSE: To make luminous energy adjustable in each lamp by connecting a plurality of dielectric barrier discharge lamps all in parallel to a power feeder, and inserting a dielectric or capacitive impedance element in series to one or more of these lamps. CONSTITUTION: A plurality of dielectric barrier discharge lamps T, T2 to T4 are connected all in parallel to a power feeder S, but to insert inductive/ capacitive impedance elements Z, Z1 , Z2 in series to one or more the lamps. In this way, voltage applied to discharge plasma spaces G, G1 to G4 of each lamp is decreased, when the impedance element is capacitive, and increased when it is inductive. Accordingly, luminous energy balance of the individual lamps in a dielectric barrier discharge device can be adjusted by selectively inserting the impedance elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is, for example, a kind of discharge lamp used as an ultraviolet light source for photochemical reaction, which forms excimer molecules by dielectric barrier discharge and utilizes light emitted from the excimer molecules. And a light source device including a so-called dielectric barrier discharge lamp.

[0002]

2. Description of the Related Art As a technique related to the present invention, Japanese Patent Laid-Open Publication No. 2-7353 discloses a dielectric barrier discharge lamp. There, the discharge vessel is filled with a discharge gas that forms excimer molecules, and a dielectric barrier discharge (also known as ozonizer discharge or silent discharge. Revised new edition “Discharge Handbook” published by the Institute of Electrical Engineers, June 1991, reprint 7
(See page 263 of press issue), an excimer molecule is formed, and a radiator for extracting light emitted from the excimer molecule is described.

The dielectric barrier discharge lamp and the light source device including the dielectric barrier discharge lamp as described above have various features that conventional low-pressure mercury discharge lamps and high-pressure arc discharge lamps do not have, and thus have a wide variety of potential applications. There is. Especially, in the recent growing concern over environmental pollution problems, pollution-free material processing using photochemical reaction by ultraviolet rays is one of the most important applications. Therefore, there is a very strong demand for the dielectric barrier discharge light source device to have a high output, a large irradiation area, and a uniform irradiation energy density or controllability.

As one of proposals meeting this requirement, there is, for example, Japanese Patent Laid-Open Publication No. 4-229671. It describes a structure in which a plurality of dielectric barrier discharge lamps are lit in parallel to increase the size of a light source and the irradiation area. However, only such a conventional technique has not been able to sufficiently meet another important requirement of uniformizing or controlling the irradiation energy density.

The reason why the irradiation energy density is required to be uniform or controllable is as follows. That is, the material treatment action by the ultraviolet rays of the dielectric barrier discharge lamp is
It is due to a highly complex and sophisticated photochemical reaction. Therefore, in order to obtain a desired material processing effect on a material having a large area, there should be no excess or deficiency of the desired irradiation energy density distribution.

The technical problems of the device for lighting a plurality of dielectric barrier discharge lamps will be described below with reference to FIG. When lighting the dielectric barrier discharge lamp, for example, 10 kHz to 200 kHz, 2
A high-frequency alternating high voltage of kV to 10 kVrms is applied. In the dielectric barrier discharge lamp (T), a space (G) of the discharge plasma is sandwiched between the electrodes (Ea) and (Eb),
There is one or two dielectrics (D), which act as a capacitor to cause a current to flow. here,
Since the voltage applied to the discharge plasma is alternating current, discharge start and discharge are repeated every half cycle,
Therefore, the dielectric barrier discharge lamp is basically a non-linear element.

However, if the discharge plasma during discharge is approximately regarded as a pure resistance, the dielectric barrier discharge lamp during discharge has an equivalent capacitor having a certain capacitance C and an equivalent resistance having a certain resistance value R. It can be approximately understood as if and are connected in series. There is a parallel capacitance in the resistance of the discharge space, but this is usually small and can be ignored.

For example, a dielectric barrier discharge having an electrode area of 200 cm ² filled with a xenon gas at a pressure of about 40,000 Pa in a discharge space formed with a gap of 4 mm between two quartz plates each having a thickness of 1 mm which is a dielectric. When the lamp is lit at a frequency of about 100 kHz and an applied voltage of about 4 kVrms, in the measurement experiment by the inventors, about 200
The result is approximately equivalent to a series connection of a pF capacitor and a resistor of about 1.5 kΩ.

However, the lighting characteristics of the lamp differ from one lamp to another due to processing errors and variations in manufacturing the lamp. For example, when a quartz material is used as the dielectric (D) of the dielectric barrier discharge lamp, the economically available quartz glass having a nominal thickness of 1 mm has a thickness variation of about ± 0.3 mm.

For this reason, the electrostatic capacitance of the lamp equivalent capacitor has a variation of about 30%. Further, if there is a variation in the distance between the two quartz plates or the pressure of the filling gas, the resistance value of the lamp equivalent resistance will also vary.

These variations appear as variations in the discharge start voltage of the dielectric barrier discharge lamp and variations in the plasma emission efficiency after the start of discharge. In the case of a dielectric barrier discharge device in which a plurality of lamps having such variations are simply connected in parallel, naturally, variations in power consumption, that is, variations in emission intensity occur among the individual lamps. Therefore, the irradiation energy density distribution deviates from the distribution expected based on the lamp arrangement at the time of device design.

On the other hand, regarding the variation of the lamps, if it is small, not all the problems concerning the irradiation energy density distribution can be solved. In general, when a certain area is irradiated with light from a plurality of lamps, the illuminance tends to decrease at the edge of the area. As a simple method for improving this, (1) the irradiation area is set wider than the necessary area, (2) the arrangement density of the lamps at the edge of the area is increased, and (3) the lamp corresponding to the edge of the area. It can be said that the method is strong, but none of them are good methods.

In the case of the method (1) in which the irradiation area is set wider than the necessary area or the lamp arrangement density at the end of the area (2) is increased, the number of lamps must be increased in the end. I won't. Further, when the lamp corresponding to the end of the region (3) is made strong, it is nothing but an increase in the type of lamp or the number of power supply devices. Therefore, both methods result in high cost.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to light a plurality of dielectric barrier discharge lamps including those having the above-mentioned variations by a common power supply device to reduce the light irradiation energy density in a necessary area. An object of the present invention is to provide an economical dielectric barrier discharge device having improved uniformity or controllability.

[0015]

In order to solve this problem, the invention according to claim 1 of the present invention provides a discharge space (G, G1) filled with a discharge gas for generating excimer molecules by dielectric barrier discharge. , G2, ..., and both electrodes (E) for inducing a discharge phenomenon in the discharge gas.
a, Ea1, Ea2 ,. ． ． ), (Eb, Eb1, Eb
2 ,. ． ． A) and a plurality of dielectric barrier discharge lamps (T, T1, ...) Having a structure in which a dielectric (D, D1, D2, ...) Is interposed between at least one of
T2 ,. ． ． ) And the electrodes (Ea, Ea1, Ea2, ...), (Ea, Ea1, Ea2, ...) Of the plurality of dielectric barrier discharge lamps.
b, Eb1, Eb2 ,. ． ． ), A power supply device for applying a high AC voltage to the plurality of dielectric barrier discharge lamps (T, T1,
T2 ,. ． ． ) Is basically connected in parallel and connected to a power supply device, and is capacitively and / or inductively connected to one or more of the plurality of dielectric barrier discharge lamps (T, T1, T2, ...). Impedance element (Z, Z1, Z
2 ,. ． ． ) Are inserted in series, the plurality of dielectric barrier discharge lamps (T, T1, T2, ...)
The power consumption balance of the impedance element (Z,
Z1, Z2 ,. ． ． ) Is not inserted, it is modified from the power consumption balance of the plurality of dielectric barrier discharge lamps (T, T1, T2, ...).

According to a second aspect of the present invention, in the first aspect of the invention, the electrodes (Ea, Ea1, Ea2, ...) And (Eb, E) of the both electrodes of each of the dielectric barrier discharge lamps are provided.
b1, Eb2 ,. ． ． 1) is commonly connected and grounded.

According to a third aspect of the present invention, in the second aspect of the invention, each of the dielectric barrier discharge lamps has electrodes (Ea, Ea1, Ea2, ...) And (E) of the both electrodes.
b, Eb1, Eb2 ,. ． ． ), One electrode (E
b, Eb1, Eb2 ,. ． ． ) Has a large portion facing the outside, and the other electrode (Ea, Ea1, Ea)
2 ,. ． ． ) Has a structure in which the portion facing the outside is small, and the electrode connected in common and grounded is the electrode having the larger portion facing the outside (Eb, E).
b1, Eb2 ,. ． ． ).

The invention of claim 4 of the present invention is the same as the invention of claim 1, claim 2 or claim 3, wherein the impedance elements (Z, Z1, Z2, ...) Inserted in series.
Is a capacitor, and the capacitance of each dielectric barrier discharge lamp (T, T1, T
2 ,. ． ． 5) or more of the electrostatic capacity at the time of discharge which is possessed by the above).

[0019]

The operation of the invention of claim 1 of the present invention will be described with reference to FIG.
Will be explained. In the configuration shown in FIG. 2, the plurality of dielectric barrier discharge lamps (T, T1, T2, ...)
All are connected in parallel to the power supply (S), but one or more lamps have inductive and / or capacitive impedance elements (Z, Z1, Z2, ...) inserted in series with the lamps. Has been done. Therefore, each lamp (T, T1, T
2 ,. ． ． ) Discharge plasma space (G, G1, G
2 ,. ． ． ) Is applied to the impedance of the lamp itself and each impedance element (Z, Z
1, Z2 ,. ． ． ) The value of the lamp discharge plasma resistance to the sum of impedances multiplied by the voltage of the power supply device.

More specifically, when the voltage of the power supply device is Vs and the angular frequency is ω, attention is paid to a certain lamp, its approximate capacitance is C, and discharge plasma of the lamp. If the approximate resistance value of R is R, then the impedance of the lamp is expressed as R-j / ωC. Also,
If the impedance of the impedance element inserted in series in the lamp is jX (ω), the voltage Vg applied to the discharge plasma of the lamp is approximately expressed as follows.

Vg = VsR / [R−j {1 / ωC−X (ω)}] (Equation 1)

The voltage Vg0 applied to the discharge plasma of the lamp when the impedance element is not inserted is expressed as follows.

Vg0 = VsR / [R-j {1 / ωC}] (Equation 2)

Therefore, it can be seen that the value of Vg can be increased or decreased to some extent by properly setting X (ω).

For example, when the impedance element to be inserted is capacitive, that is, a capacitor, if the electrostatic capacity of the capacitor is Y, then X (ω) is −1 / ωY, and the discharge plasma of the lamp is Voltage Vg applied to
Y is approximately expressed as follows.

VgY = VsR / [R−j {1 / ωC + 1 / ωY}] (Equation 3)

In this case, the voltage VgY applied to the discharge plasma can be made smaller than the voltage Vg0 when the capacitor is not inserted. When the voltage applied to the discharge plasma of each lamp decreases, the power consumption of the plasma decreases, and as a result, the amount of light emitted from the lamp decreases.

When the impedance element to be inserted is inductive, that is, a coil, if the inductance of the coil is written as L, then X (ω) is ωL, which is applied to the discharge plasma of the lamp. The voltage VgL is approximately expressed as follows.

VgL = VsR / [R−j {1 / ωC−ωL}] (Equation 4)

In this case, the resonance frequency ω determined by the electrostatic capacity C of the lamp and the inductance L of the inserted coil.
When 0 is sufficiently higher than the actually driven angular frequency ω, the voltage VgL applied to the discharge plasma can be made larger than the voltage Vg0 when the coil is not inserted. Increasing the voltage applied to the discharge plasma of each lamp increases the power consumption of that plasma, and consequently increases the amount of light emitted from that lamp.

Therefore, the amount of light emission can be adjusted for each lamp by selecting and inserting an inductive or capacitive impedance element having an impedance value corresponding to each characteristic of a plurality of dielectric barrier discharge lamps. You can

At this time, since the impedance element to be inserted does not need to have a resistance component, there is an advantage that the impedance element itself consumes no power or can be kept low.

There may be one or more lamps in which no impedance element is inserted. Further, as the impedance element to be inserted, it is possible to use all capacitors, all coils, or a mixture of capacitors and coils.

In the case of a coil, as described above, it has the effect of increasing the amount of light emitted from the lamp into which it is inserted.
For example, if there is a lamp that emits a significantly smaller amount of light than other lamps, it is effective to use it to improve this.

In the case of the capacitor, as described above, since it has the effect of reducing the light emission amount of the inserted lamp, when there is a lamp having a larger light emission amount than other lamps, the lamp It only works to reduce the amount of light emitted. However, as in the above (Equation 3), with respect to the voltage applied to the discharge plasma of the lamp, the frequency dependence of the impedance of the lamp itself (-j / ωC) and the frequency dependence of the capacitor inserted therein (-j / ΩY)
Therefore, if the impedance elements to be inserted are all capacitors, there is a great advantage that the balance of the light emission amount of each lamp hardly changes even if the drive frequency of the power supply device is changed. .

As described above, by using the invention of claim 1 of the present invention, the light emission amount balance of each lamp of the dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps is adjusted, and as a result, the irradiation energy is adjusted. It is possible to modify the density distribution to a desired one.

Regarding the operation of the invention of claim 2 of the present invention,
This will be described with reference to FIGS. 3 and 4. As shown in FIG. 3, in the invention of claim 2 of the present invention, in the invention of claim 1, a plurality of dielectric barrier discharge lamps (T, T1, T) are used.
2 ,. ． ． ) Indicates electrodes of both electrodes (Ea, Ea1, Ea)
2 ,. ． ． ), (Eb, Eb1, Eb2, ...) Of which the inductive and / or capacitive impedance element (Z, Z1, Z2, ...) Is not inserted, is commonly connected, and It is grounded, which allows
There are significant safety benefits.

Possible failures in the high voltage part of the dielectric barrier discharge device include dielectric breakdown of the inserted capacitor and burnout of the inserted coil, which may lead to electric shock to the human body. It shouldn't be. For example, as shown in FIG. 4, a dielectric barrier discharge lamp (T)
When one electrode (Ea) is connected to the high voltage side (H) of the power feeding device and the other electrode (Eb) is grounded via an inductive and / or capacitive impedance element (Z) think of. In the normal normal operation, the voltage applied to the impedance element (Z) changes the balance of the light emission amount of the lamp and is much lower than the voltage applied to both electrodes of the dielectric barrier discharge lamp (T). Therefore, the potential of the electrode (Eb) connected to the impedance element (Z) of the dielectric barrier discharge lamp (T) is
High voltage does not occur with reference to ground.

However, when the impedance element (Z) becomes nonconductive due to damage, the potential of the electrode (Eb) connected to the impedance element (Z) of the dielectric barrier discharge lamp (T) is changed. , High voltage with reference to ground. Since this part is a part that should not have a high voltage during the normal operation, there is a risk of inducing another accident.

On the other hand, in the case of the configuration of FIG. 3, both terminals of the impedance element (Z) are at a high voltage even in the normal normal operation, so that the impedance element (Z) is damaged and becomes non-conductive. In this case, the potential of the electrode (Eb) connected to the impedance element (Z) of the dielectric barrier discharge lamp (T) only drops to near the installation potential, which is advantageous in terms of safety. is there.

As described above, by using the invention of claim 2 of the present invention, it is inserted when the light emission amount balance of each lamp of the dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps is adjusted. Even if the impedance element is damaged, it is possible to ensure safety against electric shock to the human body.

Regarding the operation of the invention of claim 3 of the present invention,
This will be described with reference to FIGS. 5, 6 and 7. As shown in FIG. 5, in the invention of claim 3 of the present invention, in the invention of claim 1 or 2, the plurality of dielectric barrier discharge lamps (T, T1, T2, ...) Of the electrodes of the one of the electrodes (Eb, E
b1, Eb2 ,. ． ． ) Are commonly connected and grounded. In addition, an inductive or capacitive impedance element (Z,
Z1, Z2 ,. ． ． ) Is inserted in the wiring to the electrode (Ea, Ea1, Ea2, ...) Of which the portion facing the outside is smaller, which produces a great advantage in terms of countermeasures against electromagnetic noise.

As described above, as an example of an important application of the dielectric barrier discharge device, material treatment by ultraviolet rays can be mentioned. Such a material treatment equipment usually includes a computer and various sensors. Automatic control system. Since advanced systems of this kind are generally vulnerable to electromagnetic noise, all their components must have low electromagnetic noise generation. However, in the dielectric barrier discharge lamp in the lighting state, a high voltage is applied to the discharge space (G, G1, G2, ...) And instantaneous bursts of large current pulses are generated in the discharge plasma. The discharge space (G, G1, G2, ...) Is the main source of electromagnetic noise.

In general, the electromagnetic noise generation source can suppress the emission of electromagnetic noise to the outside by surrounding it with a grounded conductor. Here, as shown in FIG. 5, each of the dielectric barrier discharge lamps has a structure in which the portion facing the outside becomes large in one of the electrodes (Eb, Eb1, Eb2, ...) Are connected in common and grounded, this electrode (Eb, Eb1, Eb
2 ,. ． ． ) Eventually behaves like a grounded conductor surrounding the discharge space. Therefore, the effect of suppressing the emission of electromagnetic noise generated by the dielectric barrier discharge lamp can be obtained.

This effect cannot be obtained even if the electrodes (Ea, Ea1, Ea2, ...) Which have a smaller portion facing the outside are grounded. Further, even if the electrode (Eb, Eb1, Eb2, ...) Of which the portion facing the outside is larger, inductive and / or capacitive impedance for adjusting the light emission amount balance of each lamp is provided. Element (Z,
Z1, Z2 ,. ． ． With the method of grounding via), the effect can hardly be expected.

In order to maximize the effect of suppressing the emission of this electromagnetic noise, the structure of the dielectric barrier discharge lamp is, for example, as shown in FIGS. 6 and 7, most of the outer surface of the lamp itself. It is ideal to have a structure in which is covered with one electrode (Eb). Here, FIG.
FIG. 3 is a sectional view taken along line AA of the lamp shown in FIG.

The lamp shown in FIGS. 6 and 7 is composed of an outer tube (1) and an inner tube (2) made of a dielectric material such as quartz glass.
It has a structure in which both ends of the heavy pipe are sealed, and the outer pipe (1),
The hollow cylindrical space (G) surrounded by the inner tube (2) and the sealing portions (3a) and (3b) is filled with a discharge gas, and the outer tube (1) faces the outside world. One electrode (Eb) having the larger portion is provided, and the other electrode (Ea) is provided inside the inner tube (2). By forming one or both of the two electrodes as a transparent electrode or a mesh electrode, radiated light from the lamp discharge plasma can be extracted and used through the electrodes. At this time, most of the electromagnetic noise generated in the discharge space (G) is generated by grounding the electrode (Eb) provided outside the outer tube (1) and having a larger portion facing the outside. Release can be suppressed.

As described above, by using the invention of claim 3 of the present invention, it is possible to adjust the light emission amount balance of individual lamps of a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps, and It is safe in that one of the electrodes is directly and commonly grounded, and the emission of electromagnetic noise can be suppressed.

The operation of the fourth aspect of the present invention will be described with reference to FIG. In the invention of claim 4 of the present invention, in any one of the inventions of claims 1 to 3,
Impedance elements (Z, Z1, Z2, ...) Inserted in series with each dielectric barrier discharge lamp for adjusting the light emission amount balance of each dielectric barrier discharge lamp are all capacitors, and The capacitance of each dielectric barrier discharge lamp (T, T1, T
2 ,. ． ． ) Has a discharge capacity of 5 times or more.

First, when the impedance elements (Z, Z1, Z2, ...) Inserted in series are all capacitors, even if the drive frequency of the power supply device is changed, the light emission amount of each lamp is changed. It has been shown by the formula (Formula 3) representing the voltage VgY applied to the above-mentioned lamp discharge plasma that there is an advantage that the change in the balance of the above formulas hardly occurs.

On the other hand, this equation also shows that the voltage VgY applied to the lamp discharge plasma is proportional to the voltage Vs of the power supply. This property is necessary to make it possible to adjust the light emission amount of all the plurality of lamps by changing the voltage Vs of the power feeding device while maintaining the light emission amount balance adjusted by the inserted capacitor. .

However, as described above, the dielectric barrier discharge lamp is basically a non-linear element, and it is merely an approximation to regard the discharge plasma during discharge as a pure resistance having a resistance value R. In fact, during the discharge stop period that occurs in each half cycle of the AC voltage applied to the lamp,
The discharge space has an almost infinite resistance value. And
When the applied AC voltage reaches the discharge start threshold value, a discharge is generated and instantaneously becomes plasma having a finite resistance value.

During the discharge stop period, almost all of the voltage of the power supply device is applied to the discharge space, but after the discharge is started, a current flows in the discharge space, so that the voltage is divided in the inserted capacitor. The voltage applied to the discharge space will drop sharply. Here, if the value of the capacitor inserted in series with the lamp is too small, the amount of voltage division into the capacitor after the start of discharge will be too large, and therefore the sudden drop in the voltage applied to the discharge space will be too large. Then, a phenomenon occurs in which the discharge is instantaneously stopped, and this phenomenon is repeated within a short time.

Although such a state is a problem in itself, further, in this state, since the non-linearity of the phenomenon is too strong, a capacitor is inserted in series to each lamp to balance the light emission amount of the lamp. Even if it is adjusted, there is a problem that the balance of the light emission amount of each lamp is disturbed with respect to a slight change in the supply voltage of the power supply device.

The inventors of the present invention have made experiments to find that the range of the capacitance of the capacitors inserted in series for avoiding this inconvenience is 5 of the capacitance at the time of discharge of each dielectric barrier discharge lamp to be inserted. I found that it was more than double.

On the other hand, if the value of the capacitor inserted in series with the lamp is too large, the above problem does not occur. However, at this time, even after the start of discharge,
Since the amount of voltage division of the capacitor inserted in series is small, there is almost no effect of insertion. Even with such a small voltage division amount, since this circuit is basically a high voltage circuit, it is necessary to use a relatively expensive and highly reliable capacitor that is safe and reliable. There is.

As described above, the variation in the electrostatic capacity of the lamp that occurs in the normal manufacturing process using the economically available lamp material is about 30%. When a plurality of such lamps are lit, the capacitance of a capacitor inserted in series is 5% if the practical minimum amount to adjust the voltage applied to each lamp is 5%. , The dielectric capacitance of each dielectric barrier discharge lamp to be inserted should be 20 times or less of the discharging capacitance.

The value of the electrostatic capacity of the dielectric barrier discharge lamp at the time of discharge is calculated from the dielectric (D) and the electrodes (Ea) and (Eb) of both electrodes, considering the discharge space as a conductor. It is almost the same as the calculated value of the capacitance of the virtually formed capacitor. Therefore, in practice, the calculated value of the electrostatic capacity may be regarded as the same as the value of the electrostatic capacity at the time of discharging.

Specifically, the calculated value of the capacitance is obtained as follows. Let d be the thickness of the dielectric (D) (the total thickness when two dielectrics (D) are present) and ε be the dielectric constant of the dielectric (D), and the electrodes (Ea), (E
When b) is parallel and has the same area S, the value of the capacitance C when the lamp is discharged is as follows according to the well-known calculation formula of the capacitance of a parallel plate type capacitor.

C = εS / d (Equation 5)

Alternatively, when the structure of the dielectric barrier discharge lamp is a double-tube coaxial cylindrical structure as shown in FIGS. 6 and 7, the capacitance of the outer tube portion and the capacitance of the inner tube portion are Are connected in series. Specifically, the outer radius of the outer tube dielectric is R1, the inner radius is R2, the outer radius of the inner tube dielectric is R3,
If the inner radius is R4 and the electrode length is F, and the electrode length is sufficiently larger than the outer radius of the outer tube dielectric, the well-known calculation formula of the capacitance of the coaxial cylindrical capacitor is used to calculate the outer tube dielectric The electrostatic capacitance Co and the electrostatic capacitance Ci of the inner tube dielectric are as follows.

Co = 2πεF / ln (R1 / R2) (Equation 6a) Ci = 2πεF / ln (R3 / R4) (Equation 6b)

Therefore, the value of the electrostatic capacitance C during discharge of the lamp is obtained as follows.

C = Co Ci / (Co + Ci) (Equation 6c)

In the case of other shapes, it is obtained by calculation according to the shape. When the thin linear electrode has a structure in which it is stretched around a certain surface area, such as when the electrode is the mesh electrode, the area corresponding to the thickness of the thin linear electrode. Instead of considering the electrodes as electrodes, it is sufficient to consider the entire surface area roughly covered by the thin linear electrodes as a continuous electrode, assuming that there is no gap between the thin linear electrodes.

As described above, by using the invention of claim 4 of the present invention, it is possible to adjust the light emission amount balance of each lamp of the dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps. Further, even when the driving frequency of the power supply device of the dielectric barrier discharge device is changed or when the supply voltage of the power supply device is changed, there is an advantage that the balance of the light emission amount of each lamp hardly changes. can get. Furthermore, by applying the invention of claim 2 to a safe dielectric barrier discharge device, and by applying the invention of claim 3 to a safe dielectric barrier discharge device, emission of electromagnetic noise is suppressed. be able to.

[0067]

EXAMPLE FIG. 8 shows a simplified example of an example of the present invention. In the present embodiment, the power supply device (S)
Shows a device constituted by a switching inverter called a half bridge system. Rectifier diode (11
a), (11b) and smoothing capacitors (12a), (12
b) constitutes a DC power supply unit for positive, negative and zero voltages. Two field effect transistors (15a) and (15b) are connected to the DC power supply unit as switching elements for a switching inverter, and a transformer (1
A positive voltage and a negative voltage are alternately switched and applied to the primary winding of 8).

In the secondary winding of the transformer (18), a voltage is generated by multiplying the voltage of the primary winding by its winding ratio. In this embodiment, a so-called LC series resonance circuit composed of a coil (19) and a capacitor (20) is further connected, and a voltage higher than the voltage of the secondary winding of the transformer (18) is applied to the capacitor (20) due to a resonance phenomenon. ), And this voltage is supplied for lighting the four dielectric barrier discharge lamps (T, T1, T2, T3).

In this embodiment, according to claims 3 and 4 of the present invention, all the dielectric barrier discharge lamps (T, T1, T2, T3) have the shapes shown in FIGS. 6 and 7. is there. The electrodes of the larger ones of the lamps facing the outside are commonly connected and grounded. Also,
The impedance elements inserted to adjust the light emission amount balance of each lamp are all inserted as capacitors into the wiring to the electrode whose portion facing the outside is smaller. However, as an example, some of the lamps (T2) are not provided with capacitors for adjusting the balance of the light emission amount. In addition, some of the lamps (T3) have two capacitors (32
a, 32b) are inserted in series.

The reason for connecting a plurality of capacitors in series in this way is as follows. When preparing a capacitor having an electrostatic capacity corresponding to the light emission amount of each lamp in order to adjust the light emission amount balance, there are various types. However, instead, prepare only one type of capacitance for the capacitor to be prepared, or prepare a small number of capacitors, and connect them in series to insert them. Depending on the number of capacitors to be inserted, the light emission of each lamp This is because the amount of light emission can be adjusted according to the amount, and it may be more economical than the former.

For example, when the standard discharge electrostatic capacity of each lamp is 100 pF, for example, only a 2000 pF capacitor having an electrostatic capacity of 20 times this value is prepared, and depending on the light emission amount of each lamp. Therefore, it is possible to use a method of adjusting the light emission amount balance of each lamp by inserting no capacitors or inserting one, two, three, or four capacitors in series. it can.

Alternatively, as shown in FIG. 9, a plurality of capacitors connected in series is installed in advance for each lamp, and terminals (Ja, Ja1) in which no capacitors are inserted are installed according to the light emission amount of each lamp. ) It is also possible to use a method of selecting and connecting the terminals (Jb, Jb1) into which one capacitor is inserted, the terminals (Jc, Jc1) into which two capacitors are inserted, and the like. With this method, the material cost of the device will increase slightly, but the work time for adjusting the light emission balance of the lamp during device manufacturing will be shortened, and the work time for readjustment of the light emission balance during lamp replacement during device maintenance work will be shortened. Has a great effect on. Here, the number of capacitors to be connected in series in advance and the electrostatic capacity may be appropriately determined according to the expected degree of variation in the light emission amount of the lamp and the target value of the accuracy of the light emission amount balance adjustment.

Although a plurality of capacitors (32a, 32b) for adjusting the balance of light emission amount are inserted in series, they may be inserted in parallel. However, when inserting in series, the larger the number of inserted capacitors, the higher the voltage applied to the entire inserted capacitor, and at the same time, the withstand voltage of the entire capacitor automatically increases.
This is convenient because there is an advantage that each capacitor does not need to have a high withstand voltage value. On the other hand, in the case of inserting capacitors connected in parallel, such an advantage does not occur, so care must be taken.

When detecting the lighting state of each lamp, as shown in the embodiment of FIG. 9, for example, a current detector (40, 41, 42, 43) can be inserted in series with each lamp. Although the insertion position of the current detector in FIG. 8 is a high voltage portion, if a so-called CT that detects magnetism generated around the current path is used as the current detector, insulation can be relatively easily performed. Therefore, there is no problem. It should be noted that such a magnetic detection type current detector or a so-called shunt resistance current detector having a small resistance value, for example, 0.1 Ω or less has almost no influence on the operation of the inserted circuit. Do not give. Therefore, a configuration method in which the insertion position of the current detector is on the ground side of the lamp also works well. Further, this configuration method is within the scope of claim 2 or claim 3 and claim 4 of the present invention.

The output signals of the current detectors (40, 41, 42, 43) are input to the inverter control circuit (23). For example, if it is detected that a current within a normal range is flowing through each lamp and if it is detected that the current flowing through a certain lamp is too large or too small, it is determined that the lamp is abnormal, and the gate drive circuit (22). Stop the switching signal to the field effect transistors (15a), (15
It is possible to prohibit the switching operation of b) and stop the power supply to each lamp.

In the embodiment of FIG. 8, a voltage detector (21) for detecting the output voltage of the power feeding device (S) is also provided,
This output signal is input to the inverter control circuit (23),
The output voltage of the power supply device is monitored. With such a configuration, for example, if it is detected that the output voltage of the power feeding device is excessive or excessive, it is determined that the device is abnormal and the switching signal to the gate drive circuit (22) is stopped to stop the electric field. The switching operation of the effect transistors (15a) and (15b) can be prohibited, and the power supply to each lamp can be stopped.

In the embodiment shown in FIG. 8, the transformer (1
8) A current detector (17) for detecting the current flowing in the primary winding is provided, and this output signal is input to the inverter control circuit (23). For example, when an excessive current is detected, A field effect transistor (15
A configuration for stopping the switching operation of a) and (15b) is also shown.

In addition to the description here, for example, [1]. In the inverter control circuit (23), the arithmetic circuit generates the total value or the minimum value of the current values of the respective lamps indicated by the output signals of the current detectors (40, 41, 42, 43) of the respective lamps, which is set in advance. The gate drive circuit (2
Control 2) to stabilize the overall light output of the lamp.

[2]. Current detector for each lamp (40, 4
1, 42, 43) is replaced with an optical sensor for detecting the light emission amount of each lamp, and similarly, in the inverter control circuit (23), the total value of the light amount values of each lamp indicated by the output signals of these optical sensors. Alternatively, a minimum value is generated, and the gate drive circuit (22) is controlled by feedback control so that this value matches a preset target value to stabilize the overall light emission amount of the lamp.

[3]. In the inverter control circuit (23), the gate drive circuit (22) is controlled by feedback control so that the output voltage of the power supply device (S) indicated by the voltage detector (21) matches the preset target value. To stabilize the overall amount of light emitted from the lamp.

[4]. In the inverter control circuit (23), the transformer (1
The power factor of the switching inverter is set to a target value by detecting the phase of the current flowing in the primary winding of 8) and using PLL control based on the comparison between this and the voltage phase of the primary winding of the transformer (18). To improve the efficiency of the device by feedback controlling the switching frequency so that it matches with, and to adjust the light emission amount of the lamp by adjusting the power factor.

[5]. Coil (19) and capacitor (2
0) omitting the LC series resonant circuit

[6]. It is possible to improve or change the switching inverter by using another type of inverter, for example, a one-transistor inverter or a four-transistor full-bridge inverter. Can be arbitrarily implemented by the designer within the scope of the present invention.

As a matter of course, the circuit configuration shown in FIG.
This is an example in which only the main elements are described, and in the case of actual application, it should be changed accordingly depending on the characteristics of the parts used, the polarity, etc., and peripheral elements should be added as necessary. It is a thing.

[0085]

According to the invention of claim 1 of the present invention, the light emission amount balance of each lamp of a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps is adjusted,
As a result, it is possible to realize a dielectric barrier discharge device capable of modifying the distribution of irradiation energy density to a desired one.

By using the invention of claim 2 of the present invention, when the light emission amount balance of each lamp of the dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps is adjusted, the inserted impedance element is Even if it is damaged, it is possible to realize a dielectric barrier discharge device that secures safety against electric shock accidents to the human body.

By using the invention of claim 3 of the present invention, it is possible to adjust the light emission amount balance of each lamp of a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps, and also to adjust one of the electrodes. It is safe in that they are commonly grounded directly, and it is possible to realize a dielectric barrier discharge device in which emission of electromagnetic noise is suppressed.

By using the invention according to claim 4 of the present invention, it is possible to adjust the light emission amount balance of each lamp of the dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps. Further, even when the driving frequency of the power supply device of the dielectric barrier discharge device is changed or when the supply voltage of the power supply device is changed, there is an advantage that the balance of the light emission amount of each lamp hardly changes. can get. Further, a safe dielectric barrier discharge device can be realized by applying the invention of claim 2, and a safe dielectric barrier discharge in which emission of electromagnetic noise is suppressed by applying the invention of claim 3. The device can be realized.

As described above, according to the present invention, a plurality of dielectric barrier discharge lamps including those having variations are provided.
Provided is an economical dielectric barrier discharge device in which the problem of uniformity or controllability of light irradiation energy density in a required area, which has been difficult when lighted by a common power supply device, has been improved. It becomes possible to do.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a dielectric barrier discharge lamp.

FIG. 2 is an explanatory diagram of a dielectric barrier discharge device of the present invention.

FIG. 3 is an explanatory diagram of a dielectric barrier discharge device of the present invention.

FIG. 4 is an explanatory diagram of a dielectric barrier discharge device.

FIG. 5 is an explanatory diagram of a dielectric barrier discharge device of the present invention.

FIG. 6 is an explanatory diagram of a dielectric barrier discharge lamp.

FIG. 7 is an explanatory diagram of a dielectric barrier discharge lamp.

FIG. 8 is an explanatory diagram of an embodiment of the dielectric barrier discharge device of the present invention.

FIG. 9 is an explanatory diagram of an embodiment of the dielectric barrier discharge device of the present invention.

[Explanation of symbols]

 Ca, Cb Equivalent capacitor Ya, Yb, Yc, Yd Capacitor Ya1, Yb1, Yc1, Yd1 Capacitor Jd, Je, Jd1, Je1 Terminal 13 Unbiased excitation prevention capacitor

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takashi Asahina 1194 Sado, Bessho-cho, Himeji City, Hyogo Prefecture Ushio Electric Co., Ltd.

Claims (4)

[Claims] 1. A discharge space (G, G) filled with a discharge gas for generating excimer molecules by dielectric barrier discharge.
1, G2 ,. ． ． ), And electrodes (Ea, Ea1, Ea2, ...) And (Eb, Eb) of both electrodes for inducing a discharge phenomenon in the discharge gas.
1, Eb2 ,. ． ． A) and a plurality of dielectric barrier discharge lamps (T, T1, T2, ...) Having a structure in which a dielectric (D, D1, D2, ...) Is interposed between at least one of the above and the discharge gas. ), And the electrodes (Ea, Ea,
Ea1, Ea2 ,. ． ． ), (Eb, Eb1, Eb
2 ,. ． ． ), A power supply device for applying a high AC voltage to the dielectric barrier discharge device, wherein the plurality of dielectric barrier discharge lamps (T, T1, T
2 ,. ． ． ) Are basically connected in parallel and are connected to a power supply device, and the plurality of dielectric barrier discharge lamps (T, T1, T
2 ,. ． ． ) In series with capacitive and / or inductive impedance elements (Z, Z1, Z2, ...), the plurality of dielectric barrier discharge lamps (T, T1, T).
2 ,. ． ． ), The plurality of dielectric barrier discharge lamps (T, T1, T) when the impedance elements (Z, Z1, Z2, ...) Are not inserted.
2 ,. ． ． ) A dielectric barrier discharge device characterized by being modified from the power consumption balance of (1). 2. Electrodes (Ea, Ea1, Ea2, ...) And (Eb, Eb, ...) Of the both electrodes of each of the dielectric barrier discharge lamps.
Eb1, Eb2 ,. ． ． ) One is commonly connected,
The dielectric barrier discharge device according to claim 1, wherein the dielectric barrier discharge device is grounded. 3. Each of the dielectric barrier discharge lamps includes electrodes (Ea, Ea1, Ea) of the both electrodes.
2 ,. ． ． ), (Eb, Eb1, Eb2 ,. , ... have a structure in which the portion facing the outside is small, and the electrodes connected in common and grounded are the electrodes (Eb, Eb1) where the portion facing the outside is large. , Eb
2 ,. ． ． 3. The dielectric barrier discharge device according to claim 2, wherein 4. The impedance element (Z, Z1, Z2, ...) Inserted in series is a capacitor, and the capacitance thereof is a dielectric barrier discharge lamp (T, T1) to be inserted. , T2, ...) is 5 times or more of the electrostatic capacity of the dielectric barrier discharge device at the time of discharge.