JP2003100482A - Dielectric barrier discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a generation of a brightness slope between electrodes by reducing a leakage current of a dielectric barrier discharge lamp. SOLUTION: Electrodes 3, 4 are formed to the outer surface of a dielectric barrier discharge lamp, and the high voltage sides of high frequency power source 5, 6 are connected to respective electrodes 3, 4. Lower voltage sides of the high frequency power sources 5, 6 are connected to a ground voltage GND. The phase of the wave form of the output voltage of the high frequency power sources 5, 6 are made different or inverted from each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a kind of discharge lamp, in which a fluorescent substance is excited by ultraviolet rays emitted by a dielectric barrier discharge of a discharge gas enclosed in a discharge vessel, and visible light emitted by the fluorescent substance is emitted. The present invention relates to a discharge barrier discharge lamp lighting device having a so-called dielectric barrier discharge lamp to be used.

[0002]

2. Description of the Related Art Fluorescent lamps are used as light sources for illuminating originals in information equipment such as facsimiles, copying machines and image readers, and as light sources for display in large color display devices, electronic bulletin boards and the like. As a conventional fluorescent lamp used for such an application, there is known a so-called internal electrode type fluorescent lamp in which a pair of electrodes are provided inside both ends of a lamp bulb in which a discharge medium such as a rare gas is sealed. However, this fluorescent lamp has a non-uniform luminance distribution in the bulb axis direction, and the tube end is blackened to reduce the effective light emission length.
There are shortcomings such as short life. On the other hand, a so-called external electrode type dielectric barrier discharge lamp in which a pair of electrodes are provided on the outer surfaces of both ends of the lamp bulb is also used for the above application. This fluorescent lamp has a uniform luminance distribution in the tube axis direction containing mercury as compared with the internal electrode type fluorescent lamp,
There is no blackening of the tube end, and the service life is relatively long.

Such a dielectric barrier discharge lamp is shown in FIG.
It is turned on by a lighting device as shown in FIG. In the dielectric barrier discharge lamp 1, a phosphor coating is formed on the inner surface of a tubular glass bulb 2 which is a dielectric, and a rare gas such as neon or argon and a metal vapor such as mercury are sealed inside. Further, electrodes 3 and 4 are formed on both ends of the outer surface of the tubular glass bulb 2. The electrodes 3 and 4 are formed by winding a metal conductor made of aluminum (Al) or the like along the circumferential direction of the bulb. A high frequency power source 5 is connected between the pair of electrodes 3 and 4, and one electrode 4 is connected to the ground potential GND.

When a voltage is applied between the electrodes 3 and 4 by the power source 5, a high frequency electromagnetic field is generated between the electrodes due to the capacitance between the electrodes. The high-frequency electromagnetic field excites a metal vapor such as mercury enclosed in the glass bulb 2 to emit ultraviolet rays. This ultraviolet ray excites the phosphor adhered to the inner surface of the glass bulb 2 to generate a visible ray, and this visible ray is radiated to the outside of the glass bulb 2.

[0005]

The lighting method of the discharge lamp shown in FIG. 1 is such that only one of the pair of electrodes 3 and 4 has, for example, 20
Since a high voltage of 00 to 3000 V is applied, it is called a one side high voltage lighting system. For this reason, a high potential difference V is generated between the electrodes on both ends of the lamp, and the potential 3 linearly decreases from the high potential V to the ground potential GND from the electrode 3 toward the electrode 4 as shown in FIG. Such a high potential difference across the lamp causes leakage current. This leakage current is a phenomenon in which a current flowing in the tubular glass bulb 2 from one electrode 3 toward the other electrode 4 leaks to the ground potential GND in the middle thereof, and the leakage current increases as the potential difference increases. Therefore, when the lamp is lit by the lighting method shown in FIGS. 1 and 2, the current flowing in the tubular glass bulb 2 is equal to that on the high voltage side and G
A difference occurs in the current value on the ND side. For this reason, in the one-sided high-voltage lighting system, a so-called brightness gradient in which the brightness of the lamp decreases from the high-pressure side of the tubular glass bulb 2 toward the GND side appears.

Further, in the conventional one-sided high-voltage lighting system, since a high voltage of 2000 to 3000 V, for example, is applied to the one electrode 3, there is a problem that ozone is generated in the high-voltage electrode portion.

Further, in the conventional one-sided high-voltage lighting system, it has been confirmed that since the potentials of the electrode portions at both ends are greatly different, a temperature difference between the electrode portions also occurs, which adversely affects the operation of the lamp.

Therefore, the present invention eliminates the above-mentioned problems, prevents the luminance gradient due to the leakage current in high voltage driving, and obtains a substantially uniform and sufficient luminance along the tube axis of the lamp bulb. An object of the present invention is to provide a lamp lighting device.

[0009]

SUMMARY OF THE INVENTION A dielectric barrier discharge lamp lighting device according to the present invention comprises a dielectric barrier discharge lamp having a pair of electrodes formed on the outer surfaces of both ends of a lamp bulb having a discharge gas filled therein. A first and a second high frequency voltage source connected between each of the pair of electrodes of the discharge lamp and a ground potential, the first and second high frequency voltage sources being a pair of electrodes of the discharge lamp. It is characterized in that first and second high-frequency voltages having different phases are supplied to the electrodes.

In the dielectric barrier discharge lamp lighting device of the present invention, the first and second high frequency voltages are:
It is characterized in that it is a sine wave voltage of the same frequency.

Further, in the dielectric barrier discharge lamp lighting device of the present invention, the first and second high frequency voltages have the same period, different polarities, and the same amplitude. It is characterized by that.

Further, in the dielectric barrier discharge lamp lighting device of the present invention, the inverter circuit includes a switching circuit to which a DC voltage from the DC power supply is supplied,
An inverter having a primary winding to which the output of the switching circuit is supplied, a secondary winding whose center tap is connected to the ground potential, and a tertiary winding which generates a feedback signal to the input side of the switching circuit. A transformer, wherein the first and second high-frequency voltages are supplied by the secondary winding of the inverter transformer, the middle taps of which are grounded, and the windings on both sides thereof generate alternating voltages having mutually inverted phases. It is characterized by.

Further, in the dielectric barrier discharge lamp lighting device of the present invention, the dielectric barrier discharge lamp is composed of a plurality of dielectric barrier discharge lamps connected in parallel or in series. To do.

Further, in the dielectric barrier discharge lamp lighting device of the present invention, the plurality of dielectric barrier discharge lamps are arranged substantially parallel to each other, and both ends thereof are
The dielectric barrier discharge lamp is inserted and supported in an electrode formed of a pair of conductive silicone rubbers extending in a direction transverse to the tube axis direction, and the electrode formed of the pair of conductive silicone rubbers is , And are connected to the output ends of the secondary windings of the inverter transformers, respectively.

In the dielectric barrier discharge lamp lighting device of the present invention, a transistor switching circuit to which a DC voltage is supplied, a primary winding to which the output of the switching circuit is supplied, and an intermediate tap are connected to the ground potential. A one-input two-output type inverter transformer having a secondary winding and a tertiary winding for generating a feedback signal to the input side of the switching circuit, and windings on both sides of the intermediate tap of the inverter transformer. It is characterized in that the output terminals of the lines are configured to generate alternating voltages whose phases are mutually inverted.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 3 is a schematic circuit diagram of the dielectric barrier discharge lamp lighting device, and FIG. 4 is an output voltage waveform diagram of the high frequency power supply. First, referring to FIG. 3, in the dielectric barrier discharge lamp 1, a fluorescent coating is formed on the inner surface of a straight tubular glass bulb 2, and electrodes 3 and 4 are provided on both ends on the outer surface.
A rare gas is enclosed in the internal discharge space. As the filling gas, a single gas or a mixed gas selected from rare gases such as neon, argon, helium, krypton, and xenon is used. The electrodes 3 and 4 are formed by winding an aluminum tape having a predetermined width along the circumferential direction at predetermined positions on both ends of the glass bulb 2.
The inner surface may be provided with a material layer having a high light reflection property, such as SiO ₂ , TiO ₂ , or Ag. Although not shown, the outer surfaces of the electrodes 3 and 4 are covered with a transparent insulating coating made of silicon resin, PET resin or the like to prevent a short circuit between the electrodes 3 and 4. In addition to the aluminum tape, the electrodes 3 and 4 may be formed of a metal tape such as a silver tape or a conductive paint such as a silver paste.

The first high-frequency power source 5 has one electrode 3 and GN.
The second high frequency power supply 6 is connected between the other electrodes 4 and GND.

Next, the operation of the embodiment of the present invention thus constructed will be described.

In the dielectric barrier discharge lamp 1, the glass bulb 2 also serves as a dielectric, and discharge is performed through glass which is a dielectric. When a high frequency AC voltage is applied to the electrodes 3 and 4 from the first and second high frequency power supplies 5 and 6, a current does not flow directly from the electrodes 3 and 4 to the discharge space in the glass bulb 2. The glass, which is a dielectric material, interposed between the discharge space and the electrodes 3 and 4 acts as a capacitor so that a current flows. That is, the glass bulb 2
On the inner surface of the glass bulb, electric charges having the same signs and opposite signs to the surfaces on the electrodes 3 and 4 side on the inner surface of the glass bulb 2 are induced by the polarization of the glass, and discharge occurs between the inner surface of the glass bulb and the discharge space. The charges induced on the inner surface of the glass bulb 2 are neutralized by the charges moved by the discharge, and the electric field in the discharge space is reduced, so that the discharge current is stopped even if the voltage application to the electrodes 3 and 4 is continued. However, when the applied voltage further increases, the discharge current continues. When the discharge is stopped after the discharge once occurs, it is not re-discharged until the polarity of the applied voltage is reversed. That is, the current flows and discharges only immediately after the polarity of the applied voltage is reversed, and otherwise the electric current is stopped by the accumulation of charges on the inner surface of the glass bulb 2. Since a rare gas such as neon or argon is enclosed inside, the rare gas atoms are excited to the resonance level by collision with electrons due to the above discharge, and the excited atoms of this resonance level are the pressure of the rare gas. Is high, it collides with noble gas atoms of other ground levels and forms excimers of diatomic molecules. This excimer emits ultraviolet rays and returns to the two ground level noble gas atoms. The ultraviolet rays radiated by the excimer do not cause self-absorption unlike the resonance ultraviolet rays of the atoms, so they are converted into visible light by the phosphor and emit light with high brightness.

4A and 4B show output voltage waveforms of the first and second high frequency power supplies 5 and 6, respectively. As shown in the figure, these output voltage waveforms are
They have the same amplitude and are 180 degrees out of phase with each other. Now, assuming that the amplitudes of these output voltages, that is, the peak values are V / 2, at time t2 when these waveforms have peak values, + V / 2 is applied to the electrode 3 and -V is applied to the electrode 4. / 2 is applied. As a result,
As shown in FIG. 5, the potential difference between the electrodes 3 and 4 is V, and a required high voltage is applied, but a voltage of 1/2 of the peak voltage V is applied to each of the electrodes 3 and 4. Then, the potential becomes 0 at the central portion of the glass bulb 2, that is, becomes the GND level. Further, in FIG. 4, at time t1 when the output voltage waveforms of the first and second high-frequency power supplies 5 and 6 are 0 potential, the potentials of the electrodes 3 and 4 are 0 potential, and the potential difference between both electrodes is also 0 potential. Becomes further,
At time t4 when the output voltage waveforms of the first and second high frequency power supplies 5 and 6 have other peak values, -V is applied to the electrode 3.
/ 2 is applied, and + V / 2 is applied to the electrode 4. As a result, the potential difference between the electrodes 3 and 4 becomes V, and the required high voltage is applied. As described above, in the double high-voltage lighting method of the present invention, the potential difference between the electrodes 3 and 4 is a sinusoidal voltage that changes at the same frequency as the output voltage waveforms of the first and second high frequency power supplies 5 and 6 with the amplitude V. Becomes But,
The voltage applied to each of the electrodes 3 and 4 is a sine wave voltage having an amplitude of V / 2.

Therefore, compared with the conventional one-sided high-voltage lighting system shown in FIG. 1, the potential applied to the electrodes 3 and 4 is 1/2 of the required lighting voltage, so that the leakage current is half or less. Fall to. Therefore, there is almost no brightness gradient along the glass bulb 2 between the electrodes 3 and 4, and a substantially uniform brightness distribution can be obtained.

A concrete example of the above embodiment will be described. The dielectric barrier discharge lamp 1 is made of borosilicate glass and has an inner diameter of 2.0 mm, an outer diameter of 2.6 mm, and an overall length of 350 mm.
A 20-mm-thick three-wavelength phosphor coating was provided on the inner surface of the straight tubular glass bulb 2. The outer surface of the glass bulb 2 has a thickness of 0.
Electrodes 2 and 3 were formed by winding an aluminum tape having a width of 1 mm and a width of 20 mm along the circumferential direction. A mixed gas having a composition ratio of neon / argon = 90 mol% / 10 mol% was filled as a filling gas at a filling pressure of 60 Torr, and 3 mg of mercury was mixed therein. High frequency power supplies 5 and 6 are 2500 Vrm, respectively
has a voltage of s and a frequency of 45 KHz and is in phase with each other.
A generator that generates sine wave outputs that differ by 80 degrees was used. When the outputs of these high-frequency power supplies 5 and 6 were applied to the electrodes 3 and 4, respectively, a current of 10 mA flowed to the dielectric barrier discharge lamp 1 and turned on. For comparison, the conventional one-sided high voltage lighting system lighting device shown in FIG.
A sine wave output voltage having a voltage of 00 Vrms and a frequency of 45 KHz was applied to the electrodes 3 and 4. Lamp current is 5m
It was A. Further, in the dielectric barrier discharge lamp of the present invention, as compared with the conventional dielectric barrier discharge lamp, light emission of high brightness can be obtained by using a power supply of the same output voltage and a double discharge current, and the conventional dielectric barrier discharge lamp can be obtained. Almost no brightness gradient was seen in the body barrier discharge lamp. This fact indicates that in the dielectric barrier discharge lamp of the present invention, in order to operate with the same discharge current as the conventional dielectric barrier discharge lamp, the output voltage of the high frequency power supplies 5 and 6 is halved, that is, 1
This means that it can be set to 225 Vrms. Then, the decrease in the leakage current could prevent the luminance gradient.

FIG. 6 shows another voltage waveform supplied from the first and second power supplies 5 and 6. These waveforms are
The pulse voltage waveforms have the same repetition period T and opposite polarities. Even if these pulse voltages are supplied to the electrodes 3 and 4, respectively, the same effect as that of the sine wave power supply shown in FIG. 4 can be obtained.

FIG. 7 is a diagram showing still another voltage waveform supplied from the first and second power supplies 5 and 6. For these waveforms, a sinusoidal half-wave rectified waveform is used instead of the pulse waveform of FIG. 6, and these waveforms have the same phase but opposite polarities. Even if these half-wave rectified voltages are supplied to the electrodes 3 and 4, respectively, the same effect as the sine wave voltage or the pulse voltage shown in FIG. 4 or 6 can be obtained.

The output voltage waveforms of the first and second power supplies 5 and 6 shown in FIGS. 4, 6 and 7 are in phase with each other.
Although it is 80 degrees or 0 degrees, it is not always necessary to have such a relationship. That is, the waveforms shown in FIG. 8 are out of phase with each other by 180 degrees as compared with the waveforms shown in FIG.
The voltage supplied to the electrodes 3 and 4 becomes larger than V / 2 as the deviation from 180 degrees becomes larger, but can be made smaller than the potential V applied in the one-side high voltage lighting system. In the waveform shown in FIG. 9, the phase of the pulse waveform deviates from 0 degrees as compared with the waveform in FIG. But,
If the two pulse voltage waveforms have opposite polarities at the same time, the same effect as the waveform shown in FIG. 6 can be obtained. Figure 1
In the waveform shown in 0, the phase of the half-wave rectified waveform is deviated from 0 degrees as compared with the waveform in FIG. 7. However, if the two half-wave rectified voltage waveforms have opposite polarities at the same time, the same effect as the waveform shown in FIG. 7 can be obtained.

2 shown in FIGS. 4 and 6 to 10.
The two voltage waveforms do not necessarily have the same peak value. In this case, the voltage supplied to the electrodes 3 and 4 is V /
Although it is larger than 2, it can be smaller than the potential V applied in the one-side high-voltage lighting system.

FIG. 11 is a circuit diagram showing another embodiment of the dielectric barrier discharge lamp lighting device of the present invention. This lighting device is composed of a resonance type Royer inverter circuit using self-excited oscillation. Although not shown, a DC voltage from a DC power supply is supplied to the input terminal 11, and this voltage is branched so that one of them is divided into an inductance 12 and a resistor 13.
Are supplied in series to the base electrode of the transistor 14 which constitutes the inverter circuit. Inductance 1
Reference numeral 2 is a choke coil that makes the input current to the inverter circuit a constant current. The inverter circuit includes a transistor 14 and another transistor 15 whose emitter electrode is commonly grounded to the GND potential. The collector electrodes of the transistors 14 and 15 are connected to both ends of a primary winding 17 of an inverter transformer 16 which constitutes an inverter circuit. In this case, the transistor 14
Is connected to the positive electrode side of the primary winding 17, and the collector electrode of the transistor 15 is connected to the negative electrode side of the primary winding 17. Secondary winding 18 of inverter transformer 16
Has one end grounded to GND and the other end connected to one electrode 3 of the dielectric barrier discharge lamp 1. The inverter transformer 16 is also provided with a tertiary winding 19.
The ends of the tertiary winding 19 are connected to the base electrodes of the transistors 14 and 15, respectively, and the voltage generated in the tertiary winding 19 is fed back to the bases of the transistors 14 and 15. Between the both ends of the primary winding 17 of the inverter transformer 16, the inductance component of the inverter transformer 16 and L
A capacitor 20 forming a C resonance circuit is connected. Further, the DC voltage supplied from the input terminal 11 is supplied to the center tap of the primary winding 17 of the inverter transformer 16 via the inductance 12.

The DC voltage supplied from the input terminal 11 is
Further, it is connected to the intermediate tap of the primary winding 23 of the second inverter transformer 22 via the inductance 21. One end of the primary winding 23 on the positive side is the transistor 1
5 is connected to the collector electrode. In addition, the primary winding 2
One end on the negative side of 3 is connected to the collector electrode of the transistor 14. That is, the primary winding 17 of the first inverter transformer 16 and the primary winding 23 of the second inverter transformer 22 are connected so as to have opposite polarities with respect to the collector output voltages of the transistors 14 and 15. ing. A second resonance capacitor 24 that forms an LC resonance circuit with the inductance component of the second inverter transformer 22 is connected between both ends of the primary winding 23 of the second inverter transformer 22. Then, one end of the secondary winding 25 of the second inverter transformer 22 is grounded to GND, and the other end is connected to the other electrode 4 of the dielectric barrier discharge lamp 1.

Next, the operation of the lighting device for the dielectric barrier discharge lamp thus constructed will be described. Input terminal 1
When a DC voltage is applied to 1, the current flows through the inductor 12 to the primary winding 17 of the first inverter transformer 16. At the same time, the DC voltage applied to the input terminal 11 is applied to the base of the transistor 14 via the resistor 13. This input voltage is amplified by the transistor 14,
The amplified output current is supplied to the first inverter transformer 1
6 to the primary winding 17. This output current is
In the resonance circuit composed of the reactance of the inverter transformer 16 and the resonance capacitor 20,
Resonance occurs at a frequency determined by the C value, and a voltage is induced between the terminals of the tertiary winding 19 of the inverter transformer 16.
The induced voltage becomes a voltage according to the turn ratio of the primary winding 17 and the tertiary winding 19 of the inverter transformer 16. At this time, in the tertiary winding 19 of the inverter transformer 16,
A current flows in the same direction as the direction of the current flowing through the primary winding 17, and this current is input to the base electrodes of the transistors 14 and 15 to cause self-sustained pulsation. As a result, these transistors 14, 15 are alternately conducted at the resonant frequency. At this time, the oscillation frequency is determined by the reactances of the primary winding 17 and the tertiary winding 19 of the inverter transformer 16, the resonance capacitor 20, and the reactance component returned from the secondary side of the inverter transformer 16. The output of the inverter circuit at this time is the inverter transformer 16
The AC voltage whose amplitude is changed at the resonance frequency is output by boosting the winding ratio of the primary winding 17 and the secondary winding 18. This AC voltage is applied to the secondary winding 18 of the first inverter transformer 16 and the secondary winding 18 of the second inverter transformer 22.
It is output across both ends of the next winding 25. Here, the AC voltage waveform output to the secondary winding 18 of the first inverter transformer 16 and the secondary winding 2 of the second inverter transformer 22.
The phases of the AC voltage waveform output to 5 are inverted. Therefore, a potential difference corresponding to the sum of these AC voltage amplitudes is applied between the pair of electrodes 3, 4 of the dielectric barrier discharge lamp 1. In other words, since an inverter circuit that generates a voltage that is half the potential difference required to light the dielectric barrier discharge lamp 1 can be used, it is possible to light the discharge lamp without a brightness gradient due to leakage current.

FIG. 12 is a circuit diagram showing still another embodiment of the dielectric barrier discharge lamp lighting device of the present invention. Also in the lighting device of this embodiment, similarly to the embodiment of FIG. 11, it is configured by a resonance type Royer inverter circuit utilizing self-excited oscillation. However, in this embodiment, the second inverter transformer 22 in the embodiment of FIG. 11 is omitted. Except for this point, both embodiments have substantially the same circuit configuration. For this reason,
In FIG. 2, components corresponding to those in FIG. 11 are designated by the same reference numerals, and the description thereof will be omitted. Below, only different components will be described.

The inverter transformer 31 is a one-input / two-output type transformer, and the intermediate winding 33 of the secondary winding 32 is grounded to GND. And this secondary winding 32
Is wound so that the winding directions are opposite to each other on both sides of the intermediate tap 33, and the number of turns on both sides is greater than the number of turns of the primary winding 17 to boost the voltage. As a result, boosted voltage waveforms having phases different from each other by 180 degrees are obtained at the two output terminals of the secondary winding 32.

These output voltages are applied to both electrodes 3 and 4 of the dielectric barrier discharge lamp 1, and like the case of FIG. 11, the discharge lamp 1 is driven to be driven by a voltage larger than the amplitude of these voltages. You can The primary winding 17 and the tertiary winding 19 of the inverter transformer 31 have the same structure as the inverter transformer 16 of FIG.

Thus, by using the one-input / two-output type transformer as the inverter transformer 31, the primary side becomes completely common, and as compared with the case where two transformers are used as shown in FIG. 11, the core volume is reduced. Increased stability improves.

FIG. 13 is a circuit diagram showing still another embodiment of the dielectric barrier discharge lamp lighting device of the present invention. In this embodiment, the plurality of dielectric barrier discharge lamps 1 are driven in parallel by the lighting device shown in FIG. Multiple dielectric barrier discharge lamps arranged in parallel
Electrodes 41, 42 made of a pair of rod-shaped conductive silicone rubbers arranged parallel to the direction perpendicular to the plurality of dielectric barrier discharge lamps 1 are provided at both ends of 1.
Both ends of the plurality of dielectric barrier discharge lamps 1 are inserted into a plurality of holes formed in the conductive silicon rubber electrodes 41 and 42. The pair of rod-shaped electrodes 41, 42 are connected to the inverter transformer 3 at their opposite ends.
1 is connected to both ends of the secondary winding 32.

The electrodes 41 and 42 adhere to the outer peripheral surface of the lamp bulb constituting the dielectric barrier discharge lamp 1 by the stretchability of the conductive silicon rubber to form external electrodes, and at the same time, a plurality of dielectric barrier discharges are formed. The electrodes on both ends of the lamp 1 are connected to each other. As a result, the plurality of dielectric barrier discharge lamps 1 are connected to the secondary winding 3 of the inverter transformer 31.
2 will be connected in parallel.

According to the lighting device of the present invention thus constructed, the electrode portion formed by winding the aluminum tape around the outer peripheral surface of the lamp bulb generally used in the conventional dielectric barrier discharge lamp of this type. Can be omitted.
Further, with such a configuration, conventionally required to simultaneously drive a plurality of such dielectric barrier discharge lamps 1,
Since the relay board, the lead wire, or the conductive metal fitting is not required, the structure of the electrode portion can be extremely simplified.

Further, the pair of rod-shaped electrodes 41 and 42 are connected to both ends of the secondary winding 32 of the inverter transformer 31 at the opposite ends thereof, so that the potential difference due to the resistance value of the conductive silicone rubber is obtained. Are canceled out, and the high voltage applied to each of the plurality of dielectric barrier discharge lamps becomes equal. Therefore, there is an advantage that all the discharge lamps can be lit with substantially uniform brightness without causing variations in tube current and the like.

FIG. 14 is a circuit diagram showing still another embodiment of the dielectric barrier discharge lamp lighting device of the present invention. In this embodiment, two dielectric barrier discharge lamps 1-1, 1-2 connected in series are driven.
A common electrode 3 is provided at one end of each of the discharge lamps 1-1 and 1-2, and an independent electrode 4-is provided at the other end.
1, 4-2 are provided. The high voltage side terminals of the high frequency power supplies 5 and 6 are connected to these independent electrodes 4-1 and 4-2. The low voltage side terminals of these high frequency power supplies 5 and 6 are grounded to GND as in the embodiment shown in FIG. As the high frequency power supplies 5 and 6, specifically, the inverter circuits shown in FIGS. 11 and 12 are used. As the common electrode 3, the conductive silicon rubber electrode 41 or 42 shown in FIG. 13 can be used. In addition,
The electrodes 4-1 and 4-2 may be formed by winding an aluminum tape around the outer peripheral surface of a lamp bulb that is generally used in a conventional dielectric barrier discharge lamp of this type.

[0039]

According to the present invention, a high frequency power supply having a low output voltage is used to supply a high voltage output required for a dielectric barrier discharge lamp, thereby preventing a luminance gradient due to a leakage current in high voltage driving. However, a lighting device for a dielectric barrier discharge lamp is obtained which is substantially uniform along the tube axis of the lamp bulb and has sufficient brightness.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a conventional dielectric barrier discharge lamp lighting device.

FIG. 2 is a graph showing a relationship between a distance between electrodes and a voltage for explaining an operation of a conventional dielectric barrier discharge lamp lighting device.

FIG. 3 is a schematic configuration diagram of a dielectric barrier discharge lamp lighting device of the present invention.

FIG. 4 is an output voltage waveform diagram of a high frequency power source in the dielectric barrier discharge lamp lighting device of the present invention.

FIG. 5 is a graph showing the relationship between the distance between the electrodes and the voltage for explaining the operation of the dielectric barrier discharge lamp lighting device of the present invention.

FIG. 6 is an output voltage waveform diagram of a high frequency power supply according to another embodiment of the present invention.

FIG. 7 is an output voltage waveform diagram of a high frequency power supply according to still another embodiment of the present invention.

FIG. 8 is an output voltage waveform diagram of a high frequency power supply according to still another embodiment of the present invention.

FIG. 9 is an output voltage waveform diagram of a high frequency power supply according to still another embodiment of the present invention.

FIG. 10 is an output voltage waveform diagram of a high frequency power supply according to still another embodiment of the present invention.

FIG. 11 is a circuit diagram of a dielectric barrier discharge lamp lighting device according to still another embodiment of the present invention.

FIG. 12 is a circuit diagram of a dielectric barrier discharge lamp lighting device according to still another embodiment of the present invention.

FIG. 13 is a circuit diagram of a dielectric barrier discharge lamp lighting device according to still another embodiment of the present invention.

FIG. 14 is a circuit diagram of a dielectric barrier discharge lamp lighting device according to still another embodiment of the present invention.

[Explanation of symbols]

1 Dielectric barrier discharge lamp 2 Straight tubular glass bulb 3, 4 electrodes 5, 6 high frequency power supply 11 input terminals 12 Inductance 13 resistance 14, 15 transistors 16, 22 Inverter transformer 17,23 Primary winding 18, 25 Secondary winding 19 Third winding 20, 25 condenser 21 Inductance 41, 42 Conductive silicone rubber

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01J 65/00 H01J 65/00 B // F21Y 103: 00 F21Y 103: 00

Claims (16)

[Claims] 1. A dielectric barrier discharge lamp having a pair of electrodes formed on the outer surfaces of both ends of a lamp bulb in which a discharge gas is enclosed, and between each of the pair of electrodes of the discharge lamp and the ground potential. A first and a second high-frequency voltage source connected to the first and second high-frequency voltage sources,
The pair of electrodes of the discharge lamp has a first phase different from each other.
And a dielectric barrier discharge lamp lighting device characterized by supplying a second high frequency voltage. 2. The dielectric barrier discharge lamp lighting device according to claim 1, wherein the first and second high frequency voltages are sine wave voltages having the same frequency. 3. The dielectric barrier discharge lamp lighting device according to claim 2, wherein the first and second high-frequency voltages have the same cycle, different polarities, and the same amplitude. 4. The dielectric barrier discharge lamp according to claim 1, wherein the first and second high-frequency voltages are configured by an inverter circuit that receives a DC power supply as an input. Lighting device. 5. The inverter circuit includes a switching circuit to which a DC voltage is supplied from the DC power supply, a primary winding to which an output of the switching circuit is supplied, and an intermediate tap connected to the ground potential. An inverter transformer having a secondary winding and a tertiary winding that generates a feedback signal to the input side of the switching circuit, the intermediate taps of the first and second high-frequency voltages being grounded,
5. The dielectric barrier discharge lamp lighting device according to claim 4, wherein the windings on both sides are supplied by a secondary winding of the inverter transformer that generates alternating voltages having mutually inverted phases. 6. The dielectric barrier discharge lamp lighting device according to claim 5, wherein a phosphor coating is formed on the inner surface of the lamp bulb. 7. The dielectric barrier discharge lamp lighting device according to claim 1, wherein the first and second high frequency voltages output pulse waveform voltages having substantially the same frequency. 8. The dielectric barrier discharge lamp lighting device according to claim 7, wherein the first and second high-frequency voltages have substantially the same amplitude and opposite polarities. 9. The dielectric barrier discharge lamp comprises a plurality of dielectric barrier discharge lamps connected in parallel or in series with each other.
2. A dielectric barrier discharge lamp lighting device according to. 10. The plurality of dielectric barrier discharge lamps are arranged substantially parallel to each other, and both ends of the pair of dielectric barrier discharge lamps are arranged to extend in a direction transverse to a tube axis direction of the dielectric barrier discharge lamp. Inserted and supported in an electrode formed of conductive silicon rubber, the electrodes formed of the pair of conductive silicon rubbers are respectively connected to output terminals of secondary windings of the inverter transformer. The dielectric barrier discharge lamp lighting device according to claim 9. 11. The electrodes formed of a pair of conductive silicone rubbers extending in a direction transverse to the tube axis direction of the dielectric barrier discharge lamp have electrodes at opposite ends in the extension direction. 11. The dielectric barrier discharge lamp lighting device according to claim 10, wherein the device is connected to an output terminal of a secondary winding of the inverter transformer. 12. The dielectric barrier discharge lamp lighting device according to claim 11, wherein a phosphor coating is formed on an inner surface of the lamp bulb. 13. A transistor switching circuit to which a DC voltage is supplied, a primary winding to which an output of the switching circuit is supplied, a secondary winding whose center tap is connected to the ground potential, and an input to the switching circuit. A 1-input 2-output type inverter transformer having a tertiary winding for generating a feedback signal to the side, and the output terminals of the windings on both sides of the intermediate tap of this inverter transformer have mutually inverted phases. A dielectric barrier discharge lamp lighting device, which is configured to generate an AC voltage. 14. An output terminal of a secondary winding of the inverter transformer is connected to a pair of elongated electrodes formed of a pair of conductive silicone rubbers arranged substantially in parallel, respectively, and the pair of electrodes is connected to each other. The dielectric barrier discharge lamp lighting device according to claim 13, wherein both ends of a plurality of dielectric barrier discharge lamps arranged substantially in parallel are inserted and supported therein. 15. The electrodes formed of the pair of conductive silicone rubbers are connected to the output ends of the secondary windings of the inverter transformer at ends opposite to each other in the longitudinal direction thereof. 15. The method according to claim 14,
2. A dielectric barrier discharge lamp lighting device according to. 16. The dielectric barrier discharge lamp lighting device according to claim 15, wherein a phosphor coating is formed on an inner surface of the lamp bulb.