KR100572658B1 - Dielectric barrier discharge lamp lighting apparatus - Google Patents

Abstract

The plurality of dielectric barrier discharge lamps are turned on without flicker. In the dielectric barrier discharge lamp lighting device of the present invention, the DC power supply 2 is input, and one side of the secondary coil 4 of the inverter transformer 6 included in each of the plurality of inverter circuits 100, 101, and 102 is provided. By grounding and connecting the other side in parallel, the phases of the high frequency output voltages of the plurality of inverter circuits are synchronized to light each of the plurality of dielectric barrier discharge lamps without flicker, and simultaneously to connect the plurality of dielectric barrier discharge lamps with a pair of electrodes. Enable lighting.

DC power supply, coil, inverter circuit, inverter transformer, synchronous transformer

Description

Dielectric barrier discharge lamp lighting device {DIELECTRIC BARRIER DISCHARGE LAMP LIGHTING APPARATUS}

1 is a circuit diagram of a first embodiment of the present invention.

2 is a circuit diagram of a second embodiment of the present invention.

3 is a circuit diagram of a third embodiment of the present invention.

4 is a circuit diagram of a fourth embodiment of the present invention.

5 is a circuit diagram of a fifth embodiment of the present invention.

6 is a circuit diagram of a conventional dielectric barrier discharge lamp lighting device.

<Explanation of symbols for the main parts of the drawings>

2: DC power

3: primary coil

4: secondary coil

5: tertiary coil

6: inverter transformer

7: resonant capacitor

8: transistor

9: transistor

10: synchronous transformer

11: resistance

12: inductor

13: switch

100, 101, 102: inverter circuit

110: dielectric barrier discharge lamp

111: Dielectric Barrier Discharge Lamp

112: dielectric barrier discharge lamp

The present invention relates to a dielectric barrier discharge lamp lighting device.

BACKGROUND ART A dielectric barrier discharge lamp is used as a lighting device suitable for a light source for backlight of a liquid crystal display device used for a personal computer, an OA device, or the like. Particularly, a discharge lamp which generates little flicker on a liquid crystal display screen, which is a so-called dielectric barrier discharge type having electrodes on the outer surface of a tubular glass lamp container as described in Japanese Patent Application Laid-Open No. 61-126559. Low pressure discharge lamps are known.

When using such a dielectric barrier discharge type low voltage discharge lamp as a light source for backlight of a liquid crystal display device, it is necessary to light several discharge lamps simultaneously. In addition, since the number of discharge lamps to light at the same time increases with the enlargement of the display screen, it is necessary to share and drive the lighting device which lights them also by a plurality of inverter circuits. As such a lighting device, what is shown in FIG. 6 is known. In the dielectric barrier discharge lamp lighting device of FIG. 6, each of the plurality of inverter circuits 100, 101, and 102 includes the primary coil 3 on the input side, the secondary coil 4 on the output side, and the tertiary coil 5. Inverter transformer (6) having a structure, the inductance component of the inverter transformer (6) and the resonant capacitor (7) constituting the LC resonant circuit, and each emitter is grounded to drive the inverter transformer (6) The transistors 8 and 9 are provided. One end of the secondary coil 4 of each inverter transformer 6 is grounded, and the other end thereof is connected to the dielectric barrier discharge lamps 110, 111, 112.

The DC power supply terminal 2 is connected to the base of the input side transistor 8 of each inverter circuit 100, 101, 102 via a resistor 11 in series so as to supply a driving current to one transistor 8. Connected. Each emitter is grounded to the pair of transistors 8 and 9, and the primary coil 3 of the inverter transformer 6 is connected in parallel between these collectors. An intermediate tab is provided in the primary coil 3, and a DC power supply terminal 2 is connected to the intermediate tab via an inductor 12 in series. The inductor 12 is comprised by the choke coil, and makes constant current the input current to each inverter circuit 100,101,102. In addition, a resonance capacitor 7 is connected in parallel between the collectors of the pair of transistors 8, 9.

Then, a synchronous transformer 15 is provided on the primary side of each inverter transformer 6, and the primary coil of the synchronous transformer 15 is connected to a pair of transistors 8 of the inverter circuits 100, 101, and 102. , 9), and the secondary coils of the synchronous transformer 15 are connected in parallel to each other, thereby synchronizing the phases of the high frequency output voltages of the inverter circuits 100, 101, and 102. Flickering caused by the discharge lamp being driven by the high frequency voltage of the different phase was prevented. That is, the plurality of inverter circuits 100, 101, and 102 oscillate independently although they have a common frequency, so that a high frequency output in which the voltage and the phase are shifted from each other is generated on the output side of these inverter transformers 6. When each of the dielectric barrier discharge lamps 110, 111, and 112 lights up at such a high frequency output, each discharge lamp is discharged from the surface of the discharge lamp having the higher potential due to the instantaneous potential difference caused by the phase shift of the voltage. It leaks and the adjacent electric potential flows into a low discharge lamp. By repeating this phenomenon, the flicker phenomenon of the discharge lamp is induced.

[Patent Document 1]

JP-A 61-126559

[Patent Document 2]

Japanese Patent Application Laid-Open No. 2002-25786

However, in the above dielectric barrier discharge lamp lighting apparatus, the frequency and phase of the oscillation frequency are synchronized on the primary side of the inverter transformer 6 in each inverter circuit 100, 101, 102, but each inverter transformer Variation in the coupling of (6) causes a difference in the voltage value or phase generated on the secondary side, which causes a difference in luminance in the discharge lamps connected to the secondary side of each inverter transformer 6 to generate flicker. It was a cause.

The present invention has been invented to solve such a conventional technical problem, and the voltage and phase of each inverter circuit output high frequency output can be more accurately controlled without being affected by the variation in the coupling ratio or the turns ratio of the inverter transformer included in the plurality of inverter circuits. It is an object of the present invention to provide a dielectric barrier discharge lamp lighting device that can drive a plurality of dielectric barrier discharge lamps without flicker by synchronizing with them.

The dielectric barrier discharge lamp lighting device of the present invention is a dielectric barrier discharge lamp lighting device which is supplied with a direct current power source, converts a direct current into high frequency alternating current, and outputs a different dielectric barrier discharge lamp by the high frequency alternating current output. And one end of the secondary coil of the inverter transformer included in the plurality of inverter circuits is connected to each other.

In the dielectric barrier discharge lamp lighting device of the present invention, the plurality of inverter circuits include an inverter transformer having a primary coil on the input side, a secondary coil on the output side, and a tertiary coil on the input side, and the first 1 of the inverter transformer. It is connected to the primary coil, the inductance component of the primary coil and the resonant capacitor constituting the LC resonant circuit, the DC power supply and the tertiary coil output of the inverter transformer are supplied to the input side, and the output side is connected to the primary coil. The oscillation transistor is provided.

Further, in the dielectric barrier discharge lamp lighting device of the present invention, the other end of the secondary coil of the inverter transformer is grounded, and the plurality of dielectric barrier discharge lamps are respectively connected to a common connected terminal of the secondary coil of the inverter transformer. And is connected between grounds.

In the dielectric barrier discharge lamp lighting device of the present invention, the other ends of the secondary coils of the inverter transformer are also connected to each other, and the plurality of dielectric barrier discharge lamps are connected between terminals of the secondary coils of the inverter transformer. It features.

In addition, the dielectric barrier discharge lamp lighting apparatus of the present invention is supplied with a direct current power source, converts a direct current into a high frequency alternating current, and outputs the dielectric barrier discharge lamp which lights each of the different dielectric barrier discharge lamps by the high frequency alternating current output. An apparatus, wherein one end of a secondary coil of an inverter transformer included in the plurality of inverter circuits is connected to each other via a synchronous transformer, and the dielectric barrier discharge lamp is connected to the secondary coil of the inverter transformer through the synchronous transformer. It is characterized by that.

In the dielectric barrier discharge lamp lighting device of the present invention, the plurality of inverter circuits each include an inverter transformer having a primary coil on the input side, a secondary coil on the output side, and a tertiary coil on the input side, and the 1 of the inverter transformer. It is connected to the primary coil, the inductance component of the primary coil and the resonant capacitor constituting the LC resonant circuit, the DC power supply and the tertiary coil output of the inverter transformer are supplied to the input side, and the output side is connected to the primary coil. The oscillation transistor is provided.

In the dielectric barrier discharge lamp lighting device of the present invention, one end of the secondary coil of the inverter transformer included in the plurality of inverter circuits is grounded, and one end of the primary coil of the synchronous transformer is respectively connected to the other end of the secondary coil. The secondary coils of the respective synchronous transformers are connected in parallel to each other, and a dielectric barrier discharge lamp is connected between the other end of the primary coil of the synchronous transformer and the ground, respectively.

In the dielectric barrier discharge lamp lighting device of the present invention, one end of the secondary coil of each of the synchronous transformers is grounded, and the other end thereof is connected to each other.

In the dielectric barrier discharge lamp lighting device of the present invention, one end of the secondary coil of each of the synchronous transformers is grounded through a switch that can be opened and closed.

In the above-described dielectric barrier discharge lamp lighting device of the present invention, since the ends of the secondary coils of the inverter transformers included in the plurality of inverter circuits are connected to each other, the outputs of the inverter circuits have the same voltage value and have the same phase. It becomes an AC voltage. That is, since one end of the secondary coils of the inverter transformers included in the plurality of inverter circuits are connected to each other, the output voltage and the phase of this portion coincide with each other. As a result, since the high frequency voltage of the same voltage and phase propagates from the secondary coil of the inverter transformer to the primary coil side, the primary side of the inverter transformer also resonates by the high frequency voltage of the same voltage and phase.

In this way, the output of each inverter circuit whose voltage and phase coincide with each other is supplied to the dielectric barrier discharge lamps connected to the secondary coils of the inverter transformers to light them, so that each discharge lamp always emits light with the same brightness, Flicker can be prevented.

<Example>

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described in detail based on drawing. Fig. 1 shows a circuit diagram of a dielectric barrier discharge lamp lighting device of a first embodiment of the present invention. In the present embodiment, the DC power supply 2 is provided for each of the inverter circuits 100, 101, and 102. The plurality of inverter circuits 100, 101, and 102 have the same configuration, and are generally composed of a well-known resonance type inverter circuit.

Each of the inverter circuits 100, 101, and 102 includes an inverter transformer 6 having a primary coil 3 on the input side, a secondary coil 4 on the output side, and a tertiary coil 5, and the inverter transformer 6. A resonance capacitor (7) constituting an inductance component and an LC resonance circuit, and transistors (8, 9) whose respective emitters are grounded to drive the inverter transformer (6).

One end of the secondary coil 4 of each inverter transformer 6 is grounded, and the other end of the secondary coil 4 is connected in common.

The DC power supply 2 is connected to the base of the transistor 8 on the input side of each of the inverter circuits 100, 101, 102 via a resistor 11 in order to supply a driving current to one transistor 8. Connected. Between the collectors of the pair of transistors 8 and 9 with each emitter grounded, a primary coil 3 provided with an intermediate tap of the inverter transformer 6 is connected in parallel, and also for resonance. The capacitor 7 is also connected in parallel.

The DC power supply 2 further includes a primary coil of the inverter transformer 6 via a series of inductors 12 made of choke coils in series so as to constant current the input current to each of the inverter circuits 100, 101, and 102. It is connected to the intermediate | middle tap of (3).

The secondary coils 4 of the inverter transformers 6 are wound more than the primary coils 3 so that the secondary voltages are boosted. One end of the secondary coil 4 of each inverter transformer 6 is grounded and the other end is connected to each other. At the other end of the secondary coil 4, dielectric barrier discharge lamps 110, 111, and 112 are connected in parallel, respectively, and dielectric barrier discharge lamps ( 110, 111, 112 light up.

One end of the tertiary coil 5 provided in each inverter transformer 6 is connected to the base side of the transistor 8 and the other end is connected to the bass side of the transistor 9 to generate the voltage generated in the tertiary coil 5. Is fed back to the base of the transistors 8 and 9 to be applied.

Next, the operation of the dielectric barrier discharge lamp lighting device of the first embodiment of the above configuration will be described. When the DC power supply 2 is applied, current flows through the primary coil 3 of the inverter transformer 6 through each inductor 12, and at the same time, the voltage output from the DC power supply 2 passes through the resistor 11. It is applied to the base of the transistor 8.

Resonance of the primary coil 3 of each inverter transformer 6, the reactance of the tertiary coil 5 and the resonance capacitor 7 causes resonance between the terminals of the tertiary coil 5 of the inverter transformer 6. The high voltage boosted by the turn ratio of the primary coil 3 and the tertiary coil 5 of the transformer 6 is induced, and at the same time, the primary coil 3 is provided to the tertiary coil 5 of the inverter transformer 6. The current flows and oscillates in the same direction as the current flowing through the oscillation, thereby alternately conducting the transistors 8 and 9 at the resonance frequency.

The inverter transformers of the inverter circuits 100, 101, and 102 each step up by the turn ratio of the primary coil 3 and the secondary coil 4. Since the secondary coil 4 side of each inverter transformer 6 is connected to each other, the output voltage and phase of these connection parts match each other. As a result, since the high frequency voltage of the same voltage and phase propagates from the secondary coil of the inverter transformer to the primary coil side, the primary side of the inverter transformer also resonates by the high frequency voltage of the same voltage and phase.

As a result, each of the plurality of dielectric barrier discharge lamps 110, 111, and 112 is turned on by alternating phases, and the entire lighting device can be turned on without flicker.

Next, the dielectric barrier discharge lamp lighting apparatus of the second embodiment of the present invention will be described with reference to FIG. The dielectric barrier discharge lamp lighting device of the second embodiment is characterized in that both ends of the secondary coils 4 of the inverter transformer 6 of the plurality of inverter circuits 100, 101, 102 are connected in parallel with each other. The plurality of dielectric barrier discharge lamps 110, 111, 112 are connected between both ends of the secondary coil 4 of the inverter transformer 6 of the plurality of inverter circuits 100, 101, 102, respectively. Other configurations are common to the first embodiment shown in FIG.

Also by the dielectric barrier discharge lamp lighting device of this second embodiment, a plurality of dielectric barrier discharge lamps 110 driven and lighted by each of the plurality of inverter circuits 100, 101, and 102 by the same operation as in the first embodiment. , 111, 112 can be synchronized with each other to be turned on without the flicker.

Next, the dielectric barrier discharge lamp lighting apparatus of the third embodiment of the present invention will be described with reference to FIG. The characteristic of the dielectric barrier discharge lamp lighting device of the third embodiment is that one end of each of the secondary coils 4 of the inverter transformers 6 of the plurality of inverter circuits 100, 101, and 102 is grounded, and the synchronous transformer is connected to the other end thereof. The primary coils of (10) are connected in series, and are supplied to the dielectric barrier discharge lamps 110, 111, and 112 through the primary coils of the synchronous transformer 10, respectively. In addition, the secondary coil side of each synchronous transformer 10 is connected in parallel. The turn ratio of the primary coil and secondary coil of the synchronous transformer 10 is one. Other configurations are common to the first embodiment shown in FIG.

Even in the dielectric barrier discharge lamp lighting device of this embodiment, the primary side of each of the inverter circuits 100, 101, and 102 is synchronously resonated by the same operation principle as that of the first embodiment shown in FIG. Each of the barrier discharge lamps 110, 111, and 112 can be turned on without alternating flicker by alternating phases, and each of the plurality of dielectric barrier discharge lamps 110, 111, and 112 is turned on by a pair of electrodes. It becomes possible.

Next, a dielectric barrier discharge lamp lighting apparatus of a fourth embodiment of the present invention will be described with reference to FIG. In the dielectric barrier discharge lamp lighting device of the present embodiment, one end of each of the secondary coils 4 of the inverter transformers 6 of the plurality of inverter circuits 100, 101, and 102 is grounded, and the synchronous transformer ( 10) is connected to each of the dielectric barrier discharge lamps 110, 111, and 112 via the primary coil of the synchronous transformer 10. On the secondary coil side of each synchronous transformer 10, one end thereof is connected in parallel with one end of the secondary coil of another synchronous transformer 10, and the secondary coil of each synchronous transformer 10 The other end is grounded. The turn ratio of the primary coil and secondary coil of the synchronous transformer 10 is one. Other configurations are common to the first embodiment shown in FIG.

In the dielectric barrier discharge lamp lighting device of the present embodiment, the primary side of each of the inverter circuits 100, 101, and 102 is synchronously resonated and synchronized on the secondary side according to the same operation principle as that of the first embodiment shown in FIG. By paralleling the transformer 10 for the dielectric, the phases of the alternating current with respect to the dielectric barrier discharge lamps 110, 111, and 112 can be better matched, and as a result, each of the plurality of dielectric barrier discharge lamps 110, 111, and 112 is connected. By alternating phases, it can be turned on without flicker.

Next, a dielectric barrier discharge lamp lighting apparatus of a fifth embodiment of the present invention will be described with reference to FIG. In the dielectric barrier discharge lamp lighting device of the present embodiment, one end of each of the secondary coils 4 of the inverter transformers 6 of the plurality of inverter circuits 100, 101, and 102 is grounded, and the synchronous transformer ( 10) is connected to each of the dielectric barrier discharge lamps 110, 111, and 112 via the primary coil of the synchronous transformer 10. On the secondary coil side of each synchronous transformer 10, one end thereof is connected in parallel with one end of the secondary coil of another synchronous transformer 10, and the secondary coil of each synchronous transformer 10 The other end is grounded via the switch 13. The turn ratio of the primary coil and secondary coil of the synchronous transformer 10 is one. Other configurations are common to the first embodiment shown in FIG.

In the dielectric barrier discharge lamp lighting device of the present embodiment, the state in which the switch 13 is opened has a circuit configuration equivalent to that of the first embodiment shown in FIG. 1, and accordingly the same operation principle as that of the first embodiment. By synchronously resonating the primary sides of the inverter circuits 100, 101, and 102, as a result, each of the plurality of dielectric barrier discharge lamps 110, 111, and 112 can be turned on without alternating flicker by alternating phases. In the dielectric barrier discharge lamp lighting device of the present embodiment, the state in which the switch 13 is closed has a circuit configuration equivalent to that of the fourth embodiment shown in FIG. Each of the dielectric barrier discharge lamps 110, 111, and 112 can be turned on without alternating flicker by alternating phases.

As described above, according to the present invention, in the above-described dielectric barrier discharge lamp lighting device of the present invention, since one ends of the secondary coils of the inverter transformers included in the plurality of inverter circuits are connected to each other, the output of each inverter circuit is The same voltage value results in an AC voltage having the same phase. That is, since one end of the secondary coils of the inverter transformers included in the plurality of inverter circuits are connected to each other, the output voltage and the phase of this portion coincide with each other. As a result, since the high frequency voltage of the same voltage and phase propagates from the secondary coil of the inverter transformer to the primary coil side, the primary side of the inverter transformer also resonates by the high frequency voltage of the same voltage and phase.

In this way, the output of each inverter circuit whose voltage and phase coincide with each other is supplied to the dielectric barrier discharge lamps connected to the secondary coils of the inverter transformers to light them, so that each discharge lamp always lights up with the same brightness without flicker. You can.

Claims (9)

A dielectric barrier discharge lamp lighting device comprising a plurality of inverter circuits supplied with a direct current power source, converting a direct current into a high frequency alternating current, and lighting the plurality of different dielectric barrier discharge lamps by the high frequency output. One end of the secondary coils of the inverter transformer included in the plurality of inverter circuits is connected to each other. Dielectric barrier discharge lamp lighting device. The method of claim 1, The plurality of inverter circuits are each connected to an inverter transformer having a primary coil on the input side, a secondary coil on the output side, and a tertiary coil on the input side, and the primary coil of the inverter transformer, and the inductance component of the primary coil. And a resonant capacitor constituting the LC resonant circuit, and an oscillation transistor having a DC power supply and a tertiary coil output of the inverter transformer supplied to an input side and having an output side connected to the primary coil. Discharge lamp lighting device. The method of claim 2, The other end of the secondary coil of the inverter transformer is grounded, and the plurality of dielectric barrier discharge lamps are connected between a common connected terminal and a ground of the secondary coil of the inverter transformer, respectively. Chi. The method of claim 3, The other ends of the secondary coils of the inverter transformer are also connected to each other, and the plurality of dielectric barrier discharge lamps are connected between terminals of the secondary coils of the inverter transformer, respectively. A dielectric barrier discharge lamp lighting device comprising a plurality of inverter circuits supplied with a direct current power source, converting a direct current into a high frequency alternating current, and lighting the different dielectric barrier discharge lamps by the high frequency output. One end of the secondary coils of the inverter transformer included in the plurality of inverter circuits is connected to each other through a synchronous transformer, and the dielectric barrier discharge lamp is connected to the secondary coils of the inverter transformer through the synchronous transformer. Dielectric barrier discharge lamp lighting device. The method of claim 5, In the dielectric barrier discharge lamp lighting device, the plurality of inverter circuits are each connected to an inverter transformer having a primary coil on the input side, a secondary coil on the output side, and a tertiary coil on the input side, and the primary coil of the inverter transformer. An oscillation transistor in which an inductance component of the primary coil and a resonant capacitor constituting the LC resonant circuit, a DC power supply and a tertiary coil output of the inverter transformer are supplied to an input side, and an output side thereof is connected to the primary coil. Dielectric barrier discharge lamp lighting device comprising a. The method of claim 6, One end of the secondary coil of the inverter transformer included in the plurality of inverter circuits is grounded, and one end of the primary coil of the synchronous transformer is connected to the other end of the secondary coil, and the secondary coil of each of the synchronous transformers is connected. The dielectric barrier discharge lamp lighting device is connected in parallel with each other, and a dielectric barrier discharge lamp is connected between the other end of the primary coil and the ground of the synchronous transformer, respectively. The method of claim 7, wherein And one end of the secondary coil of each of the synchronous transformers is grounded, and the other end thereof is connected to each other. The method of claim 8, And one end of the secondary coil of each of the synchronous transformers is grounded through an openable switch.

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