JP3059348B2 - Dielectric barrier discharge device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a technique related to the present invention, a dielectric barrier discharge lamp is disclosed, for example, in Japanese Patent Laid-Open Publication No. Hei 2-7353, which discloses a discharge gas for forming excimer molecules in a discharge vessel. And excimer molecules are formed by a dielectric barrier discharge (also known as an ozonizer discharge or a silent discharge. See the revised Electric Discharge Handbook published by the Institute of Electrical Engineers of Japan in June 2001, reprinted 7th page, page 263). An emitter for extracting emitted light is described.

The above-described dielectric barrier discharge lamp and the light source device including the same have various features not found in conventional low-pressure mercury discharge lamps and high-pressure arc discharge lamps, and thus have a wide variety of application possibilities. I have. Above all, with the increasing interest in environmental pollution problems in recent years, non-polluting material processing using photochemical reactions by ultraviolet rays is one of its most important applications. Therefore, there is a very strong demand for higher output or larger irradiation area for the dielectric barrier discharge light source device.

One proposal meeting this requirement is, for example, Japanese Patent Laid-Open Publication No. Hei 4-229671, in which a plurality of dielectric barrier discharge lamps are operated in parallel to increase the size of a light source and increase the irradiation area. It describes a configuration for achieving this. However, there are two major problems that cannot be solved only by such conventional techniques. The first problem is that the emission of electromagnetic noise increases as the output increases and the irradiation area increases, that is, as the power of the device increases. The second problem is that it is difficult to make the irradiation energy density uniform or controllable when irradiating a large area.

[0005] Regarding the first problem, that is, the large electromagnetic noise emission, the situation where improvement is required is briefly described below. In recent years, there has been a particularly strong demand for suppression of noise emission that causes electromagnetic interference, and in general, all devices are required by various regulations to keep the noise emission level below a specified standard. I have.
In fact, as mentioned above, an example of an important application of the dielectric barrier discharge device is material processing by ultraviolet rays, but such material processing equipment usually constitutes an advanced automatic control system including a computer and various sensors. Because advanced systems of this type are generally susceptible to electromagnetic noise, all components of the dielectric barrier discharge device, such as a large-scale, high-power dielectric barrier discharge device that simultaneously turns on multiple lamps, generate low electromagnetic noise. Obviously it must be.

Regarding the second problem, that is, the difficulty in making the irradiation energy density uniform or controllable, the reason why the improvement is required will be briefly described below. The material processing action of the dielectric barrier discharge lamp by ultraviolet rays is extremely complicated and is due to a high degree of photochemical reaction.In order to obtain a desired material processing effect for a large area material, a desired irradiation energy density distribution is required. There must be no excess or deficiency in the distribution. If the irradiation energy density is insufficient, it is clear that this is a problem because the irradiation effect is low. On the other hand, even when the irradiation energy density is excessive, for example, decomposition products due to irradiation ultraviolet rays may cause re-reaction and unintended molecular synthesis may be performed, and a non-uniform impurity layer may be formed on the surface of the target processing material. . Therefore,
There is a certain allowable range for the excess and deficiency of the irradiation energy density depending on the type of material processing reaction to be performed. For an ideal dielectric barrier discharge device, the irradiation energy density satisfies this allowable range. Is required, and in order to achieve it, the device is required to be controllable.

The reason why the first and second problems occur in the dielectric barrier discharge device will be described below with reference to FIGS.
This will be described with reference to (b) and (c). When the dielectric barrier discharge lamp is turned on, for example, a frequency of 10 kHz to 200 kHz and a voltage of 2 kV are applied to the pair of electrodes E and F.
A high-frequency AC high voltage of 10 to 10 kVrms is applied (see FIG. 1A). However, in the dielectric barrier discharge lamp T, one or two dielectrics D exist between the electrodes E and F with the discharge plasma space G interposed therebetween, and this acts as a capacitor so that a current flows. (See (b) of FIG. 1). Here, since the voltage applied to the discharge plasma is an alternating current, the discharge start and the discharge stop are repeated every half cycle, so that the dielectric barrier discharge lamp is basically a non-linear element. However, if one considers the discharge plasma during discharge to be approximately a pure resistance, that is, a dielectric barrier discharge lamp during discharge has an equivalent capacitor having a certain capacitance C and an equivalent capacitor having a certain resistance R. It can be approximately understood that the resistor and the resistor are connected in series (see (c) in FIG. 1). There is also a capacitance in parallel with the resistance of the discharge space,
Usually this is small and can be ignored. For example, thickness 1m
The gap Y between the two quartz plates of 4 m was set to 4 mm, and this was used as a discharge space G. A dielectric barrier discharge lamp having an electrode area of 200 cm ² filled with xenon gas at a pressure of about 40,000 Pa (based on 25 ° C.) was used. When the lamp is turned on at 100 kHz and an applied voltage of about 4 kVrms, in the measurement experiment conducted by the inventors, a capacitor of about 200 pF and about 1.
The result was obtained that the resistance was approximately equivalent to that obtained by connecting a 5 kΩ resistor in series.

As described above, the dielectric barrier discharge lamp performs a non-linear operation in which the discharge is started and stopped every half cycle, and the discharge is performed under the application of a high voltage to the discharge space G. Occurs. Therefore, at the moment when the voltage applied to the discharge space reaches the discharge start voltage, a large current pulse is generated in the discharge plasma, and intense electromagnetic noise including harmonics generated from the discharge space G is generated. . This is the reason why the electromagnetic noise emission in the dielectric barrier discharge device of the first problem is large.

In the manufacture of lamps, there are always processing errors and variations in the material procurement or manufacturing process, and the lighting characteristics of the lamps differ from one lamp to another. For example, when a quartz material is used as the dielectric material D of the dielectric barrier discharge lamp, the quartz glass having a nominal thickness of 1 mm which is economically available has a thickness variation of 0.3 mm.
mm. For this reason, the capacitance of the lamp equivalent capacitors varies individually by about 30%. Further, if there is a variation in the distance between the two quartz plates and the pressure of the filling gas, the resistance value of the lamp equivalent resistance will vary. These variations are
This appears as a variation in the discharge starting voltage of the dielectric barrier discharge lamp and a variation in the plasma emission efficiency after the start of the discharge. In the case of a dielectric barrier discharge device in which a plurality of lamps having such a variation are simply connected in parallel, a variation in power consumption, that is, a variation in emission intensity occurs for each lamp, and the irradiation energy density distribution is reduced. The distribution is deviated from the expected distribution based on the lamp arrangement at the time of designing the device. This is the reason why it is difficult to equalize the irradiation energy density in the dielectric barrier discharge device in the second problem.

[0010] Further, regarding the variation of the lamp, if it is small, not all the problems concerning the irradiation energy density distribution can be solved. Generally, when a certain area is irradiated with light from a plurality of lamps, the illuminance tends to decrease at the end of the area. As a simple way to improve this, set the irradiation area wider than the required area, increase the arrangement density of the lamp in the end area,
Although a method of increasing the intensity of the lamp corresponding to the end region is used, none of these methods is good. In the case of setting the irradiation area wider than the required area or increasing the arrangement density of the lamps in the end area, it is inevitable to increase the number of lamps, and the lamp corresponding to the end area must be added. Being more powerful means more lamps or more power supplies,
In each case, the cost is high. That is, even if there is no variation in the lamp, it is not economically possible to improve the irradiation energy density distribution to a desired one, for example, a uniform one. This is the reason why it is difficult to control the irradiation energy density in the dielectric barrier discharge device in the second problem.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to achieve the first problem of suppressing electromagnetic noise emission, and at the same time, a plurality of dielectric barrier discharges including those having the above-mentioned variations. An object of the present invention is to provide an economical dielectric barrier discharge device in which the problem of difficulty in uniforming or controlling the light irradiation energy density in a necessary area, which is the second problem, even when the lamp is turned on is improved. is there.

[0012]

In order to solve this problem, a first aspect of the present invention is to provide a discharge space (G, G) filled with a discharge gas for generating excimer molecules by dielectric barrier discharge. ₁ , G ₂ , ‥‥) and a pair of electrodes (E, E) for inducing a discharge phenomenon in the discharge gas.
E ₁ , E ₂ , ‥‥), (F, F ₁ , F ₂ , ‥‥) and at least one of the dielectrics (D,
D _1, D _2, a plurality of dielectric barrier discharge lamp having a structure in which ‥‥) mediated _{(T, T 1, T 2} , ‥‥) and, the one counter electrode (E of the respective dielectric barrier discharge lamp, E ₁ ,
E ₂ , ‥‥) and (F, F ₁ , F ₂ , ‥‥), a power supply device for applying a high AC voltage to the dielectric barrier discharge lamp (T, T
₁ , T ₂ , ‥‥), one power supply device (S, S ₁ , S ₂ , ‥‥) is provided corresponding to each of the power supply devices (S, S ₂ , ‥‥). S ₁ , S ₂ , ‥‥) are asynchronous with each other in the phase of the output vibration wave, and each of the power supply devices (S, S ₁ , S ₂ , ‥‥) can independently adjust the output power. This makes it possible to arbitrarily adjust the power consumption balance of each of the dielectric barrier discharge lamps (T, T ₁ , T ₂ , ‥‥).

According to a second aspect of the present invention, in the first aspect of the invention, signals (K, K ₁ , K ₂ ) of different frequencies generated from the signal (X) of one oscillator (M) are provided. ,
‥‥), the respective power supply devices (S, S ₁ , S ₂ , ‥)
Ii) is to excite the output vibration wave.

According to a third aspect of the present invention, in any one of the first and second aspects, the frequency of the output vibration wave of each of the power supply devices (S, S ₁ , S ₂ ,...) The average frequency values are different from each other by 2% or more.

According to a fourth aspect of the present invention, in the first aspect, the pair of electrodes (E, E ₁ , E) of each of the dielectric barrier discharge lamps is provided.
₂ , ，) and (F, F ₁ , F ₂ , が), a portion where one electrode (F, F ₁ , F ₂ , 部分) faces the outside is large, and the other electrode (E, E ₁ , E ₂ , ‥‥) has a structure in which a portion facing the outside has a small structure,
The electrode (F,
F ₁ , F ₂ ,...) Are commonly connected and grounded.

[0016]

The operation of the first aspect of the present invention will be described with reference to FIG. In the configuration shown in FIG. 2, a plurality of dielectric barrier discharge lamps (T, T ₁ , T ₂ ,...) Each have one power supply device (S, S ₁ , S ₂ ,.
‥‥) is provided. Each of these power supply devices (S,
S ₁ , S ₂ , ‥‥) are asynchronous with each other in the phase of the output vibration wave, and can independently adjust the output power. The important point here is that the power supply device is an aggregate of small power supply devices (S, S ₁ , S ₂ , ‥‥) and is asynchronous with each other in the phase of the output vibration wave.
As a result, the advantage of the measure against electromagnetic noise and the advantage of controllability of the irradiation energy density can be obtained at the same time.

In a high power dielectric barrier discharge device,
The reason why the electromagnetic noise is large is that, even if the electromagnetic noise generated by one lamp is large enough to be acceptable, the electromagnetic noise from a plurality of lamps is added and becomes large. When adding noises, the problem becomes most serious when the noises are added cooperatively, that is, when the electromagnetic noise from each lamp is coherent. For example, as can be seen from the fact that, in general, in an electromagnetic radiation test of an electric device, whether or not a radiated power spectrum distribution is equal to or less than a regulation value is measured, electromagnetic noise of a specific frequency is measured. The most problematic is the radiated noise. For example, Japanese Patent Application Laid-Open No. 4-229671, which is described in the section of the related art, describes a configuration in which a plurality of lamps are lit in parallel by one power supply device. In the configuration, since the discharge phenomena in each lamp occur completely synchronously, the electromagnetic noise generated from them is radiated cooperatively at a specific frequency, and therefore, the electromagnetic noise is considered to have a large influence on the outside. Can be

On the other hand, in the configuration according to the first aspect of the present invention, even when a plurality of lamps are turned on, each of the small power supply devices (S, S ₁ , S) that turns on only one lamp is provided. ₂ ) and ‥‥) operate asynchronously with each other in the phase of the output vibration wave, so that they are not added cooperatively when adding the electromagnetic noise from each lamp. Will be widely spread in the radiated power spectral distribution, and as a result will be reduced to a low overall electromagnetic noise emission level without producing intense emission at a particular frequency. It should be noted that the simplest method for making the phases of the output vibration waves of the power supply devices (S, S ₁ , S ₂ , ‥‥) asynchronous with each other is the method of each power supply device (S, S ₁ , S ₂ , ‥‥). ) Have independent oscillation frequency determining means, and each oscillation frequency is set to be slightly different. However, unless the independent oscillating frequency determining means uses, for example, a precision and high stability crystal oscillator, the oscillating frequencies of all the power supply devices (S, S ₁ , S ₂ , ‥‥) are strictly mutually strict. Because they are different, the influence of the electromagnetic noise radiation is reduced without intentionally shifting the oscillation frequencies from one another, but if it is desired to effectively reduce the electromagnetic noise radiation, each oscillation frequency must be slightly reduced. It is better to set so as to have a difference each time.

On the other hand, it is relatively easy to adjust the output power of the power supply device itself, but when a plurality of lamps are connected in parallel to this, it is necessary to adjust the power consumption for each lamp. Is very difficult. For example,
The configuration described in Japanese Patent Application Laid-Open No. Hei 4-229671, which is also described in the section of the prior art, is such that the power consumption adjustment for each individual lamp is completely impossible. Has become. In contrast,
In the configuration according to the first aspect of the present invention, it is possible to independently adjust the output power of each power supply device corresponding to each lamp, so that each dielectric barrier discharge lamp (T, T ₁ , T ₂ , ‥‥) makes it possible to arbitrarily adjust the power consumption balance, so that it is possible to adjust the light emission amount balance of each lamp, and as a result, to obtain a desired distribution of the irradiation energy density.

As described above, by using the invention of claim 1 of the present invention, in a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps, the electromagnetic noise emission level in the radiated power spectrum distribution can be suppressed to be low. In addition, it is possible to adjust the light emission balance of the individual lamps, and as a result, to change the distribution of the irradiation energy density 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. According to a second aspect of the present invention, in the first aspect, signals (K, K ₁ , K ₂ , ‥‥) of different frequencies generated from the signal (X) of one oscillator (M). Thus, the output vibration wave of each of the power supply devices (S, S ₁ , S ₂ , ‥‥) is excited.

In the description of the operation of the first aspect of the present invention, when it is desired to effectively reduce electromagnetic noise emission, each oscillation frequency of each power supply device (S, S ₁ , S ₂ ,. It is better to have something that has a little difference from the above. However, unless the independent oscillation frequency determining means uses an expensive, precise and highly stable crystal oscillator, it is not possible to reliably and stably maintain such a state that each oscillation frequency has a little difference. What is important here is the certainty and stability of the state in which each oscillation frequency has a slight difference, and the stability of the frequency value itself is not required. The invention of claim 2 of the present invention is to use an inexpensive component to reliably and stably maintain a state in which each oscillation frequency has a small difference without unnecessarily increasing the stability of the frequency value itself. Can be realized.

A clock signal (X) from one oscillator (M) that does not require such a high frequency stability is provided corresponding to each of the power supply devices (S, S ₁ , S ₂ ,...). Frequency converters (H, H ₁ , H ₂ , ‥‥)
Is input to Each frequency converter _{(H, H 1, H 2} , ‥
A simple method of realizing ii) is to configure them by a frequency dividing circuit and change the respective frequency dividing ratios little by little. For example, when the oscillation frequency of the oscillator (M) is 1 MHz and the frequency division ratios of the respective frequency dividers are 48, 49, 50, 51, and 52, respectively, the signals (K , K ₁ , K ₂ , ‥‥)
Are 20.8 kHz and 20.4 kHz, respectively.
z, 20.0 kHz, 19.6 kHz, 19.2 kHz
Becomes

The simplest frequency dividing circuit (B) as the frequency converter (H) is, as shown in FIG. 4, mainly composed of, for example, a digital down counter (Q).
When the count value of the down counter (Q) becomes zero, a load signal (J) is issued to the down counter itself (Q) to load a preset value (V) smaller than the frequency division ratio by one. Such a well-known circuit may be used and can be realized at very low cost. Another way of realizing each of the frequency converters (H, H ₁ , H ₂ ,...) Is to configure them by a frequency multiplier and change their respective frequency multipliers little by little. For example, the oscillation frequency of the oscillator (M) is 200 Hz, and the frequency multiplication ratios of the respective frequency multiplication circuits are 98, 99, 100,
When 101 and 102 are set, the frequencies of the signals (K, K ₁ , K ₂ , ‥‥) generated by the respective frequency multipliers are 19.6 kHz, 19.8 kHz, 20.0 kHz,
20.2 kHz and 20.4 kHz. As is well known, the frequency multiplier can be realized by a PLL circuit to which a frequency divider is applied.

As described above, each of the power supply devices (S, S) has a different frequency generated from the signal of one oscillator.
The advantage of exciting the output oscillating wave of S ₁ , S ₂ , ‥‥) is that the ratio of each frequency is equal to the frequency converter (H, H ₁ ,
H ₂ , ‥‥), for example, when the frequency divider is a frequency converter (H, H ₁ , H ₂ , ‥‥), the frequency divider is determined by the frequency division ratio. Even if the signal (X) generated from has a frequency fluctuation due to, for example, a temperature change, the ratio of each frequency is kept unchanged,
Therefore, each of the power supply devices (S, S ₁ , S ₂ ,.
Ii) The state where the frequencies of the output vibration waves are different from each other is maintained. Therefore, the state of low electromagnetic noise emission is reliably and stably maintained without using an expensive oscillator with high stability as one transmitter (M). Thus, by using the invention of claim 2 of the present invention, a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps can be used without using an expensive oscillator.
It is possible to reliably and stably maintain the state where the electromagnetic noise emission level in the emission power spectrum distribution is kept low. Further, since the features of the first aspect of the present invention are inherited, it is possible to adjust the light emission amount balance of the individual lamps and modify the distribution of the irradiation energy density to a desired one.

The operation of the third aspect of the present invention will be described. According to a third aspect of the present invention, in any one of the first and second aspects of the present invention, the frequency of the output vibration waves of each of the power supply devices (S, S ₁ , S ₂ ‥‥) is equal to the average frequency value. 2% or more.

In the description of the operation of the first aspect of the present invention, if the difference between the frequencies of the output vibration waves of the power supply devices (S, S ₁ , S ₂ ,. The effect is small, and it is understood that the difference between the frequencies has to be taken to some extent. In order to effectively reduce electromagnetic noise emission, it is sufficient from experience that the difference between the oscillation frequencies is 2% or more of the average frequency value. Of course, a frequency difference significantly larger than 2% can be provided, but in such a case,
It is necessary to pay attention to the phenomenon that the difference between the oscillating frequencies appears strictly as a difference between the lighting conditions of the lamps. If the difference between the oscillating frequencies is too large, the light emitting states of the lamps are different from each other. Occurs. The maximum limit of the frequency difference at which the difference in the light emission state is allowed is empirically 20%. As an example, in a device that lights up five lamps simultaneously, for example, when considering each difference evenly for each lamp, by subtracting 1 from the number of lamps, that is, by dividing 20% of the maximum limit by 4, Since a value of 5% is obtained, in the case of this example, it is limited that the frequencies of the power supply devices differ from each other by 5% of the average frequency value.

As described above, by using the invention of claim 3 of the present invention, in a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps, the electromagnetic noise emission level in the radiated power spectrum distribution is suppressed to a low level. The state can be reliably realized. In addition, since the characteristics of the first aspect of the present invention are basically inherited, it is possible to adjust the light emission amount balance of each lamp and change the distribution of the irradiation energy density to a desired one. .

Regarding the operation of the invention of claim 4 of the present invention,
This will be described with reference to FIGS. 5, 6, and 7. As shown in FIG. 5, in the invention according to claim 4 of the present invention, in the invention according to any one of claims 1, 2 and 3, a plurality of dielectric barrier discharge lamps (T, T ₁ , T _2, of the pair of electrodes of ‥‥), towards the electrode is large portion facing the outside _{(F, F 1, F 2} , ‥‥) are and are grounded commonly connected. This provides a further advantage in terms of measures against electromagnetic noise.

As described above, an example of an important application of the dielectric barrier discharge device is material processing using ultraviolet rays. In a dielectric barrier discharge lamp in a lighting state, a discharge space (G, G _{1) is used.} , G ₂ , ‥‥), and a burst of a large instantaneous current pulse is generated in the discharge plasma, so that the discharge space (G, G ₁ , G ₂ ,.
‥‥) is the main source of electromagnetic noise. In general, an electromagnetic noise generation source can suppress emission of electromagnetic noise to the outside by surrounding it with a grounded conductor. Here, as shown in FIG. 5, the portion facing the outside of each dielectric barrier discharge lamp is one electrode (F,
F ₁ , F ₂ , ‥‥), the electrodes are commonly connected and then grounded.
₁ , F ₂ , ‥‥), after all, behaves like a grounded conductor surrounding the discharge space. Therefore, an effect of suppressing emission of electromagnetic noise generated by the dielectric barrier discharge lamp is obtained. Note that this effect cannot be obtained even if the electrode (E, E ₁ , E ₂ , が) whose portion facing the outside is smaller is grounded.

In order to maximize the effect of suppressing the emission of the electromagnetic noise, the structure of the dielectric barrier discharge lamp is, for example, as shown in FIGS. Ideally, most of the structure is covered with one electrode (F). Here, FIG.
It is AA sectional drawing of the lamp shown in FIG. The lamp shown in FIGS. 6 and 7 has an outer tube 1 made of a dielectric material such as quartz glass.
And has a structure in which both ends of a double tube composed of the inner tube 2 and the inner tube 2 are sealed, and discharges into a hollow cylindrical space (G) surrounded by the outer tube 1, the inner tube 2, and the sealing portions 3a and 3b. One electrode (F) having a larger portion facing the outside is provided outside the outer tube 1 and the other electrode (E) is provided inside the inner tube 2. I have. Here, when one or both of the two electrodes are formed as a transparent electrode or a reticulated electrode, the emitted light from the lamp discharge plasma can be extracted and used through the electrodes. At this time, the discharge of the most part of the electromagnetic noise generated by the discharge space (G) is suppressed by grounding the electrode (F) having a larger portion facing the outside provided outside the outer tube 1. can do.

As described above, according to the fourth aspect of the present invention, in the dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps, one of the electrodes is directly grounded in common. Therefore, it is possible to realize a dielectric barrier discharge device that is safe and suppresses emission of electromagnetic noise. In addition, since the characteristics of the first aspect of the present invention are basically inherited, it is possible to adjust the light emission amount balance of each lamp and change the distribution of the irradiation energy density to a desired one. .

[0033]

FIG. 8 schematically shows an example of an embodiment of the present invention. In the present embodiment, the power supply device (S)
In the figure, a device constituted by a switching inverter called a half-bridge method is shown. A common DC power supply is constituted by a rectifier diode bridge 11 and a smoothing capacitor 12 from a normal commercial power line 10. This DC power is supplied to a chopper including a field effect transistor 14, a diode 15, and a choke coil 16 in the power supply device (S). The output of the chopper is
Smoothing is performed by two serially connected capacitors 17a and 17b having substantially the same capacitance to form a chopper type DC power supply dedicated to the power supply device (S). This chopper type DC power supply can change the voltage by adjusting the duty cycle of the gate drive circuit 13 having a variable duty cycle. In this chopper type DC power supply, two field effect transistors 20a and 20b are connected as switching elements for a switching inverter, and the direction of the current flowing through the primary winding of the transformer 22 is alternately switched. The switching operation is
The gate drive circuit 19 is driven by the gate drive circuit 19, and operates according to the signal K supplied from the frequency converter (H). The secondary winding of the transformer 22 includes:
Generally, a voltage having an amplitude equal to a value obtained by multiplying the voltage of the capacitor 17a or 17b by the turn ratio is generated. In this embodiment, a so-called LC series resonance circuit including the coil 23 and the capacitor 24 is further connected, and By phenomenon
A voltage higher than the voltage of the secondary winding of the transformer 22 is generated across the capacitor 24, and this voltage is supplied for lighting the dielectric barrier discharge lamp (T).

Since the structure of the other power supply devices (S ₁ , S ₂ , S ₃ ) is similar to the structure of the power supply device (S), FIG.
Are omitted. Power supply devices (S ₁ , S ₂ , S
₃ ), signals (K ₁ , K ₂ , K ₃ ) for defining respective switching timings are supplied from frequency converters (H ₁ , H ₂ , H ₃ ). The power supply devices (S ₁ , S ₂ , S ₃ ) supply respective output voltages for lighting the dielectric barrier discharge lamps (T ₁ , T ₂ , T ₃ ). Each frequency converter (H, H ₁ , H ₂ ,
H ₃ ) generates respective signals (K, K ₁ , K ₂ , K ₃ ) from the clock signal (X) of one oscillator (M) according to the second aspect of the present invention. The frequency divider (B) shown in FIG.
The frequency division ratios are different from each other, so that the output vibration waves of each power supply device (S, S ₁ , S ₂ , S ₃ ) are excited at different frequencies.

In a half-bridge type switching inverter as shown in FIG.
9 indicates, for example, the supplied signals (K, K ₁ , K ₂ ,
It is often easy to economically configure one that performs a switching operation of one cycle in two cycles of K ₃ ). In such a case, the feeding device _{(S, S 1, S 2} , S 3) signals supplied to the _{(K, K 1, K 2} , K 3) the ramp (T, T _1,
The output frequency of the oscillator (M) may be corrected to be twice the driving frequency to be supplied to T ₂ , T ₃ ). In addition, all the dielectric barrier discharge lamps (T, T ₁ , T ₂ ,
T ₃ ) has the shape shown in FIGS. 6 and 7 in accordance with the invention of claim 4 of the present invention, and the portion facing the outside is connected to the larger electrode in common and grounded.

In this embodiment, the gate drive circuit 13 having a variable duty cycle is provided independently for each power supply device and can be adjusted independently. Therefore, according to the dielectric barrier discharge device of the present embodiment, as described in the description of claim 1 of the present invention, the electromagnetic noise emission level in the radiated power spectrum distribution is suppressed to a low level, and the luminous intensity balance of each lamp is reduced. It is possible to adjust and consequently modify the distribution of the irradiation energy density to the desired one.

Further, the dielectric barrier discharge device of the present embodiment provides the signal (X) generated from the transmitter (M) as described in the description of the second aspect of the present invention.
In addition, even if there is a frequency fluctuation due to, for example, a temperature change or the like, the ratio of each frequency is kept unchanged, so that the frequency of the output vibration wave of each of the power supply devices (S, S ₁ , S ₂ , S ₃ ) is always Different states are maintained, so that a low state of electromagnetic noise emission is reliably and stably maintained. Further, in the dielectric barrier discharge device of the present embodiment, as described in the description of the invention of claim 4 of the present invention, all the lamps have the shapes shown in FIGS. A structure in which most of the outer outer surface is covered with one electrode (F), and all of the electrodes (F) that cover most of the outer outer surface of the lamp are commonly connected and grounded. Therefore, it is safe and emission of electromagnetic noise is suppressed.

It is to be noted that the following configuration is possible in addition to the above description. (1) For example, based on feedback control, the output voltage of a chopper type DC power supply, that is, the entire voltage of the two capacitors 17a and 17b connected in series is detected, and the detected voltage coincides with a variably set target voltage. A chopper-type DC power supply whose output voltage is variable and stabilized by automatically adjusting the duty cycle of the gate drive circuit 13. (2) For example, the voltage applied to the lamp, the current flowing through the lamp, or the light emission amount of the lamp is detected, and the duty cycle of the gate drive circuit 13 based on the feedback control is adjusted so as to match the target level of the variable setting. A power supply device in which lamp power is variable and approximately stabilized by automatic adjustment. (3) For example, the switching inverter may be an inverter of another system, for example, one composed of one transistor,
What is called a full bridge system consisting of four transistors. (4) For example, without providing a chopper type DC power supply, by automatically adjusting the duty cycle of the switching inverter or based on feedback control,
A power supply device in which lamp power is variable or variable and approximately stabilized. (5) For example, composed of a coil 19 and a capacitor 20,
Do not use an LC series resonance circuit.

The above (1) to (5) are arbitrarily implemented by the designer within the scope of the present invention. Incidentally, as a lamp current detector for the feedback control and the like,
A method of detecting magnetism generated around the current path (so-called CT) or a so-called shunt resistor having a small resistance value, for example, 0.1Ω or less, has almost no effect on the operation of a circuit in which it is inserted. Therefore, a configuration method in which the insertion position of the current detector is on the ground side of the lamp works well, and this configuration method is within the scope of claim 4 of the present invention.

In the above embodiment, any one of the plurality of power supply devices (S, S ₁ , S _{2 2} ) is provided.
In each case, one or more dielectric barrier discharge lamps to be supplied with electric power are one lamp, but the one lamp is connected in parallel with a plurality of lamps whose emission intensity difference is within an allowable value. It may be replaced with a connected one. In this case, an operation of selecting a lamp having a difference in emission intensity within an allowable value is added. However, the present discharge device functions well, and this configuration method is within the scope of claim 1 of the present invention. is there. And, of course, the circuit configuration and the like shown in FIG. 8 is an example in which the main elements are described. Modifications should be made accordingly and peripheral elements added as needed.

[0041]

By using the invention of claim 1 of the present invention, in a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps, the electromagnetic noise emission level in the radiated power spectrum distribution is suppressed to a low level. Thus, it is possible to realize a dielectric barrier discharge device capable of adjusting the light emission amount balance of the lamps and changing the irradiation energy density distribution to a desired one.

By using the invention of claim 2 of the present invention, a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps can be used without using an expensive oscillator.
A dielectric barrier discharge device capable of reliably and stably maintaining a state in which the electromagnetic noise emission level in the emission power spectrum distribution is kept low can be realized.

By using the invention of claim 3 of the present invention, in a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps, it is ensured that the electromagnetic noise emission level in the radiated power spectrum distribution is kept low. A dielectric barrier discharge device that can be realized can be realized.

By using the invention of claim 4 of the present invention, in a dielectric barrier discharge device including a plurality of dielectric barrier discharge lamps, it is safe in that one of the electrodes is commonly directly grounded. In addition, it is possible to realize a dielectric barrier discharge device in which emission of electromagnetic noise is suppressed.

As described above, according to the present invention, when illuminating a plurality of dielectric barrier discharge lamps including those having variations, the uniformity of the light irradiation energy density in a necessary region, which has been more difficult than in the prior art, has been made. It is possible to provide an economical dielectric barrier discharge device in which the problem of controllability or controllability is improved, and the electromagnetic noise emission level in the radiated power spectrum distribution is kept low.

[Brief description of the drawings]

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

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

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

FIG. 4 is an explanatory diagram of a frequency dividing circuit.

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

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

FIG. 7 is an explanatory diagram relating to a dielectric barrier discharge lamp shown in a section AA in FIG. 6;

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

[Explanation of symbols]

First dielectric of the outer tube 2 dielectric inner tube 3a, 3b sealing portion 13 the gate drive circuit 19 gate drive circuit B frequency divider C equivalent capacitor C _1, C ₂ equivalent capacitor D dielectrics E, F pair of electrodes G Discharge space H Frequency converter M Oscillator R Equivalent resistance S Feeder T Dielectric barrier discharge lamp

──────────────────────────────────────────────────続 き Continued on front page Examiner Naohide Murata (58) Field surveyed (Int.Cl. ⁷ , DB name) G21K 5/00

Claims (4)

(57) [Claims] A discharge space (G, 1) filled with a discharge gas for generating excimer molecules by a dielectric barrier discharge.
G ₁ , G ₂ ,...), And a pair of electrodes (E, E ₁ , E ₂ ,...) For inducing a discharge phenomenon in the discharge gas.
‥‥), (F, F ₁ , F ₂ , ‥‥) and at least one of the dielectrics (D, D ₁ , D ₂ ,
‥‥) having a plurality of dielectric barrier discharge lamps (T, T ₁ , T ₂ , ‥‥) interposed therebetween; and the pair of electrodes (E,
A dielectric barrier discharge device comprising: a power supply device for applying an AC high voltage to (E ₁ , E ₂ , ‥‥) and (F, F ₁ , F ₂ , ‥‥); _{(T, T 1, T 2} , ‥‥)
Corresponding to each of the power supply devices (S, S ₁ ,
S ₂ , ‥‥) are provided, and the power supply devices (S, S ₁ , S ₂ , ‥‥) are asynchronous with each other in the phase of the output vibration wave, and Since the device (S, S ₁ , S ₂ , ‥‥) can independently adjust the output power, the power consumption balance of each of the dielectric barrier discharge lamps (T, T ₁ , T ₂ , ‥‥) can be adjusted. A dielectric barrier discharge device characterized by being arbitrarily adjustable. 2. A signal (K, K ₁ , K ₂ , K ₂ , K ₁ , K ₂ , K ₁ ) of different frequencies generated from a signal (X) of one oscillator (M).
‥‥), the respective power supply devices (S, S ₁ , S ₂ , ‥)
2. The dielectric barrier discharge device according to claim 1, wherein the output vibration wave of ‥) is excited. 3. The power supply device (S, S ₁ , S ₂ ,.
I) The frequency of the output vibration wave is equal to the average frequency value of 2
3. The dielectric barrier discharge device according to claim 1, wherein the dielectric barrier discharge device is different by at least%. 4. A pair of electrodes (E, E ₁ , E ₂ , ‥‥), (F, F ₁ , F ₂ , ‥) of each of the dielectric barrier discharge lamps.
‥), the portion where one electrode (F, F ₁ , F ₂ , ‥‥) faces the outside is large, and the other electrode (E, E ₁ ,
E ₂ , ‥‥) has a structure in which the portion facing the outside is small, and the portion facing the outside is the larger electrode (F, F ₁ , F ₂ , ‥‥). 4. The dielectric barrier discharge device according to claim 1, wherein the dielectric barrier discharge device is commonly connected and grounded.