KR20080047866A - Plasma display device and power device thereof - Google Patents

Abstract

A plasma display device and a power supply device thereof are provided to suppress oscillations by flowing currents having opposite flows to each other in a common mode choke. A power supply device of a plasma display device includes an input filter(610), a power factor compensation circuit(620), a POD(Point Of Deployment) voltage generator(640), and a switch unit. The input filter filters a noise of AC voltages outputted from an AC(Alternating Current) voltage source. The power factor compensation circuit converts the AC voltages into DC(Direct Current) voltages and outputs DC voltages compensated power factor. The POD voltage generator, which is connected to an output stage of the input filter, generates voltages in a POD wait mode. The switch unit, which is connected to a second end of the AC voltage source and connected between the output stage of the input filter and the power factor compensation circuit, is turned off in the POD wait mode.

Description

Plasma display device and power supply thereof {PLASMA DISPLAY DEVICE AND POWER DEVICE THEREOF}

1 is a configuration diagram showing a part of a power supply device of a conventional plasma display device.

2 is a diagram illustrating a plasma display device according to an exemplary embodiment of the present invention.

3 is a view schematically showing an entire block of a power supply unit according to an embodiment of the present invention.

4 is a view showing in detail the input filter according to an embodiment of the present invention.

The present invention relates to a plasma display device, and more particularly, to a power supply device for supplying power for driving a plasma display device.

A plasma display device is a display device that displays characters or images by using plasma generated by gas discharge, and tens to millions or more pixels (discharge cells) are arranged in a matrix form according to their size. The plasma display device is classified into a direct current type and an alternating current type according to the shape of a driving voltage waveform to be applied and the structure of a discharge cell.

In the panel of the DC plasma display device, since the electrode is exposed to the discharge space as it is, the current flows in the discharge space while the voltage is applied, and for this purpose, a resistance for limiting the current must be made. On the other hand, the panel of the AC plasma display device has an advantage that the electrode is covered with a dielectric layer, so that the current is limited by the formation of a natural capacitance component and the life is longer than that of the DC type because the electrode is protected from the impact of ions during discharge.

On the other hand, the standby state of the plasma display device is largely divided into a standby mode (Stand-by mode) and a POD mode (Point of Deployment, limited reception module).

In the standby mode, when the on signal is input by the remote controller when the power is applied, power is applied to the driving unit of the plasma display device to operate.

On the other hand, the POD mode has the purpose of forcing a screen to notify the crisis situation in a national crisis situation such as an exhibition or a disaster. At this time, since power must be forcibly turned on, power consumed by the POD module consumes about 15 times as much power as in the standby mode. In addition, excessive current flows, causing a lot of loss and heat. In particular, a problem arises in that noise is generated in a common mode choke of an AC line filter due to a large current.

1 is a configuration diagram showing a part of a power supply device of a conventional plasma display device.

As shown in FIG. 1, in the conventional power supply device, a common mode filter 10a including common mode chokes L1 and L2 and capacitors C1 and C2 is connected to both ends of an AC power source. Input switches S1 and S2 are connected to the second stage of FIG. 10a (which means the lower end of the common mode filter 10a in FIG. 1). A common mode filter 10b including common mode chokes L3 and L4 and capacitors C3 and C4 is connected between the input switches S1 and S2 and the bridge diode BD.

Therefore, the current flows to the POD voltage generator through the common mode filter 10a in the second stage of the AC power supply while the screen is turned off. At this time, since the input switches S1 and S2 are turned off, in the case of the common mode filter 10b connected to the rear ends of the input switches S1 and S2, no current flows. As shown in FIG. 1, the current generated in the bridge diode BD flows to the first stage of the AC power source. At this time, in the case of the common mode filter 10a connected between the AC power supply and the input switch, current flows in both directions in the first and second stages, thereby reducing vibration as much as possible.

However, in the case of the common mode filter 10b connected between the input switches S1 and S2 and the bridge diode BD, since the input switches S1 and S2 are turned off, the current cannot flow to the second stage. The current flows only in the first stage. Therefore, since a current flows only in one common mode choke L3 among the common mode chokes constituting the common mode filter 10b, the balance between the common mode chokes is lost and noise caused by tremor and vibration is greatly generated. There is this.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the problems of the prior art, and to provide a plasma display device and a power supply device capable of reducing noise in a POD standby mode as much as possible.

According to an aspect of the present invention, a power supply device for supplying a voltage to a plasma display device in a POD standby mode includes an input filter for filtering an alternating voltage output from an AC power source; A power factor correction circuit for converting the AC voltage into a DC voltage and compensating and outputting the power factor; A POD voltage generator connected to an output terminal of the input filter to generate a voltage output in the POD standby mode; And a switch unit turned off in the POD standby mode and connected to a second end of the AC power source. In this case, the switch unit is connected between the output terminal of the input filter and the power factor correction circuit unit.

According to another aspect of the present invention, a plasma display device includes a plasma display panel in which a plurality of discharge cells are formed; A driving unit driving the plasma display panel; And a power supply unit supplying power to the driving unit. In this case, the power supply unit, the AC voltage output from the AC power source including a capacitor connected between the first and second common mode choke and coupled to both ends of the AC power source, respectively, the first and second common mode choke An input filter unit for filtering the filter; A POD voltage generator connected to a contact of an output terminal of the input filter unit to generate a voltage to be output to the driver in a POD standby mode; And at least one switch that is turned off in the POD standby mode and is connected between the input filter unit and the driving unit.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

A plasma display device and a driving device thereof according to an embodiment of the present invention will now be described in detail with reference to the drawings.

2 is a diagram illustrating a plasma display device according to an exemplary embodiment of the present invention.

As shown in FIG. 2, a plasma display device according to an exemplary embodiment of the present invention includes a plasma display panel 100, a controller 200, an address electrode driver 300, a scan electrode driver 400, and a sustain electrode driver 500. And a power supply unit 600.

The plasma display panel 100 includes a plurality of address electrodes A1 to Am extending in the column direction, and a plurality of sustain electrodes X1 to Xn and scan electrodes Y1 to Yn extending in pairs in the row direction. Include. The X electrodes X1 to Xn are formed corresponding to the respective Y electrodes Y1 to Yn, and generally have one end connected in common to each other. The plasma display panel 100 includes a substrate (not shown) on which the sustain and scan electrodes X1 to Xn and Y1 to Yn are arranged, and a substrate (not shown) on which the address electrodes A1 to Am are arranged. The two substrates are disposed to face each other so that the scan electrodes Y1 to Yn and the address electrodes A1 to Am and the sustain electrodes X1 to Xn and the address electrodes A1 to Am are orthogonal to each other. At this time, the discharge space at the intersection of the address electrodes A1 to Am and the sustain and scan electrodes X1 to Xn and Y1 to Yn forms a discharge cell.

The controller 200 receives an image signal from the outside and outputs an address driving control signal, a sustain electrode X driving control signal, and a scan electrode Y driving control signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield is composed of a reset period, an address period, and a sustain period.

The address electrode driver 300 receives an address drive control signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode A. FIG.

The scan electrode driver 400 receives the scan electrode Y driving control signal from the controller 200 and applies a driving voltage to the scan electrode Y.

The sustain electrode driver 500 receives the sustain electrode X driving control signal from the controller 200 and applies a driving voltage to the sustain electrode X.

The power supply unit 600 supplies power required for driving the plasma display device to the control unit 200 and the respective driving units 300, 400, and 500.

3 is a view schematically showing the entire block of the power supply unit 600 according to an embodiment of the present invention.

As shown in FIG. 3, the power supply unit 600 includes an input filter 610, a power factor correction circuit 620, a DC-DC converter 630, and a POD voltage generator 640.

The input filter 610 filters to remove noise from an AC voltage input from the outside, and a line filter for removing noise applied to an AC line output from an AC power source and a common filter for removing common mode noise. Noise filters, and the like. In particular, the common mode noise filter composed of a common mode choke and a capacitor reduces the common mode noise by attenuating the magnetic flux of two currents flowing in opposite directions through the common mode choke.

The power factor correction circuit 620 receives a rectified voltage (propagation rectified voltage) by the input filter 610 and the bridge diode BD and outputs a constant DC voltage Vo, and the output DC voltage Vo is It is input to the DC-DC converter 630. Here, the bridge diode BD rectifies the AC input AC through the diode, and the DC-DC converter 630 receives the DC voltage Vo output from the power factor correction circuit 620 and receives a plurality of DC voltages ( Vs, Va, Vset, Ve, Vscan) are output. The plurality of DC voltages Vs, Va, Vset, Ve, and Vscan output from the DC-DC converter 630 are used as voltages for driving the plasma display device.

The POD voltage generator 640 receives an AC voltage output from the input filter 610 and outputs a POD voltage.

Hereinafter, a detailed method for reducing noise caused by vibration in the POD standby mode will be described in detail with reference to FIG. 4.

4 is a detailed view of the input filter 610 according to an embodiment of the present invention.

As shown in FIG. 4, the input filter 610 includes one or more common mode filters 610a and 610b. The common mode filter 610a includes a common mode choke L1 and L2 and capacitors C1 and C2 coupled thereto. That is, one end of the common mode chokes L1 and L2 are coupled and connected to both ends of the AC power, and the capacitors C1 and C2 are connected in parallel to both ends of the common mode choke L1 and L2.

The common mode filter 610b is connected to the common mode filter 610a, and the common mode filter 610b is connected to the common mode chokes L3 and L4 and the capacitor C3, which are coupled like the common mode filter 610a. C4).

At this time, the common mode filters 610a and 610b form an LC filter, and the common mode chokes L1, L2, L3, and L4 serve to remove low-frequency common mode noise, and the capacitors C1, C2, and C3. , C4) removes the common mode noise of the high band.

That is, the coupled common mode choke L1, L2, L3, L4 winds coils of the same inductance in one direction on one closed core in the opposite direction to prevent magnetization of the core by the current supplied to the load. Therefore, the common magnetic fluxes L1 and L2 and the common mode chokes L3 and L4 cancel each other's magnetic flux flowing in the reverse direction to remove common mode noise.

As described above, the common mode chokes L1 and L2 and the capacitors C1 and C2 form one common mode filter 610a, and the common mode chokes L3 and L4 and the capacitors C3 and C4 are similar to each other. Common mode filter 610b is formed.

In FIG. 4, the input filter 610 is configured as two common mode filters 610a and 610b. However, since the magnitude of noise may vary according to the input AC power, more common mode filters may be connected. . In addition, a normal mode filter may be further added between the AC power supply and the bridge diode (BD) to remove normal mode noise, and the filter may be configured in various forms. The POD voltage generator 640 is connected to the contacts at both ends between the common mode filter 610b and the first input switch S1.

The first input switch S1 and the second input switch S2 are connected between the common mode filter 610b and the bridge diode BD. In particular, the resistor R2 is parallel to the second input switch S2. When the inrush current flows rapidly, it is prevented from entering the power factor correction circuit.

At this time, by connecting the first input switch (S1) and the second input switch (S2) between the input filter 610 and the bridge diode (BD), as shown in Figure 4 from the bridge diode (BD) input filter ( A current path is formed to the first end of the AC power via 610, and a current path is formed to the POD voltage generator 640 via the input filter 610 at the second end of the AC power. That is, in the POD standby mode, only AC power is supplied while the screen is turned off, and since the input switches S1 and S2 are turned off, the input filter 610 is connected between the AC power and the input switches S1 and S2. Thus, current flows through both common mode filters included in the input filter 610.

Accordingly, current flows in the opposite directions to the common mode chokes L1 and L2 and the common mode chokes L3 and L4 forming the common mode filters 610a and 610b, respectively, and flows between the coupled common mode chokes. By balancing the current, vibration noise generated in POD standby mode can be minimized.

That is, the first input switch S1 and the second input switch S2 which are turned off in the POD mode are connected between the input filter 610 and the bridge diode BD to form a common mode choke. Currents in opposite directions flow to prevent vibration as much as possible.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the present invention, in the POD power supply apparatus, noise due to vibration in the POD standby mode may be reduced.

Claims (10)

A power supply for supplying a voltage to a plasma display device in a POD standby mode, An input filter for filtering an AC voltage output from an AC power source; A power factor correction circuit for converting the AC voltage into a DC voltage and compensating and outputting the power factor; A POD voltage generator connected to an output terminal of the input filter to generate a voltage output in the POD standby mode; And A switch unit turned off in the POD standby mode and connected to a second end of the AC power source; And the switch unit is connected between an output terminal of the input filter and the power factor correction circuit unit. The method of claim 1, And a DC-DC converter configured to convert the output voltage of the power factor correction circuit into a plurality of DC voltages capable of driving the plasma display. The method of claim 1, The input filter, A first common mode choke having a first end connected to a first end of the AC power source; A second common mode choke having a first end connected to a second end of the AC power source; A first capacitor connected to a first end of the first common mode choke and a first end of the second common mode choke; And And at least one common mode filter comprising a second capacitor connected to a second end of the first common mode choke and a second end of the second common mode choke. The method of claim 3, In the POD standby mode, A first current path is connected to the power factor correction circuit, the input filter, and a first end of the AC power source, And a second current path connected to a second end of the AC power source, the input filter, and the POD voltage generator. The method of claim 4, wherein And a current flowing in opposite directions to the first common mode choke and the second common mode choke. The method of claim 1, The switch unit And a first switch, a second switch, and a resistor connected in parallel with the second switch. A plasma display panel in which a plurality of discharge cells are formed; A driving unit driving the plasma display panel; And It includes a power supply for supplying power to the drive unit, The power supply unit, An input filter unit for filtering an AC voltage output from the AC power source, including a first and second common mode chokes coupled to both ends of an AC power source and a capacitor connected between the first and second common mode chokes, respectively ; A POD voltage generator connected to a contact of an output terminal of the input filter unit to generate a voltage to be output to the driver in a POD standby mode; And And at least one switch turned off in the POD standby mode and connected between the input filter unit and the driving unit. The method of claim 7, wherein The power supply unit, A power factor correction circuit for converting the AC voltage into a DC voltage and compensating and outputting the power factor; And a DC-DC converter configured to convert the output voltage of the power factor correction circuit into a plurality of DC voltages capable of driving the driver. The method of claim 8, In the POD standby mode, A first current path is connected to the power factor correction circuit, the input filter, and a first end of the AC power source, And a second current path connected to a second end of the AC power source, the input filter, and the POD voltage generator. The method of claim 9, And plasma flow in opposite directions to the first common mode choke and the second common mode choke.

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