KR100672311B1 - Apparatus for driving plasma display panel - Google Patents

Abstract

An apparatus for driving a plasma display panel is provided to reduce manufacturing cost by generating a bias voltage and supplying the bias voltage to a sustain common electrode during a bias period, using a few capacitors instead of a separate bias voltage source. An apparatus for driving a plasma display panel includes a voltage charging unit(10) and a voltage supply unit(12). When a sustain down voltage is supplied to a sustain common electrode, the voltage charging unit is charged at an absolute value of the sustain down voltage. The voltage supply unit supplies a bias voltage to the sustain common electrode during a bias period. The bias voltage is generated by the voltage, which is charged in the voltage charging unit. The voltage charging unit includes capacitors(C1,C2) and a sustain down switch(susdn). The capacitors are series-connected between a sustain up voltage and the sustain common electrode. The sustain down switch is arranged between the sustain common electrode and the sustain down voltage and turned on during the sustain down period.

Description

Apparatus for driving plasma display panel

1 is a waveform diagram exemplarily illustrating a driving waveform of a PDP supplied to each subfield.

2 is a circuit diagram of an embodiment of a driving apparatus of a plasma display panel according to the present invention.

3 and 4 are views for explaining the operation of the driving apparatus of the plasma display panel according to the present invention shown in FIG.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device of a plasma display panel (hereinafter referred to as "PDP"), and more particularly to a PDP driving device which eliminates the need for a bias voltage source.

In the conventional AC type surface discharge PDP, time division driving is performed by dividing one frame into several subfields having different emission counts in order to realize gray level of an image. In this case, each subfield may include a reset period for initializing the entire screen, an address period for selecting a scan line and selecting a cell from the selected scan line, and gradation depending on the number of discharges. It is divided into sustain periods.

FIG. 1 is a waveform diagram exemplarily illustrating a driving waveform of a PDP supplied to each subfield, and illustrates a signal Y supplied to a scan electrode and a signal Z supplied to a sustain common electrode.

Referring to FIG. 1, each subfield is divided into a reset period, an address period, and a sustain period. In the reset period, the rising ramp waveform Ramp-up is simultaneously applied to all the scan electrodes Y in the set-up period SU. In the set-down period SD, the rising ramp waveform Ramp-up is supplied, and then the falling ramp waveform Ramp-down falls at a positive voltage lower than the peak voltage of the rising ramp waveform Ramp-up. Is simultaneously applied to the scan electrodes (Y). Ramp-down generates a weak erase discharge in the cells, thereby eliminating unnecessary charges among the wall charges and the space charges generated by the setup discharges, and allowing each of the following address operations to be performed smoothly. Initialize the state of the cell.

In the address period, the negative scan pulse Scan is sequentially applied to the scan electrodes Y, and the positive data pulse data is applied to the address electrodes X. As the voltage difference between the scan pulse and the data pulse and the wall voltage generated in the reset period are added, an address discharge is generated in the cells to which the data pulse is applied.

In the sustain period, the sustain up voltage and the sustain down voltage are alternately applied to the scan electrodes Y and the sustain electrodes Z as the sustain pulse su. That is, a high level voltage is applied in the sustain up period, and a low level voltage is applied in the sustain down period.

Referring to FIG. 1, the bias voltage Vbias is applied to the sustain common electrode in the set down period SD and the address period of the reset period for a stable addressing operation. For this purpose, the conventional PDP driving apparatus must separately prepare a bias voltage source to generate a bias voltage. As described above, the conventional PDP driving apparatus has to provide a separate bias voltage source, thereby increasing the cost of the product.

An object of the present invention is to provide a plasma display panel driving apparatus capable of generating a bias voltage and applying it to a sustain common electrode without a separate bias voltage source.

In order to achieve the above object, a driving apparatus of a plasma display panel according to the present invention includes a voltage charging unit which charges an absolute value of the sustain down voltage when a sustain down voltage is supplied to a sustain common electrode, and the charged voltage on the charged voltage. And a voltage supply unit for supplying the generated bias voltage to the sustain common electrode in the bias period.

Hereinafter, the configuration and operation of an embodiment of a driving apparatus of a plasma display panel according to the present invention will be described with reference to the accompanying drawings.

2 is a circuit diagram of an embodiment of a driving apparatus of a plasma display panel according to the present invention, which includes an energy recovery unit 5, a voltage charging unit 10, and a voltage supply unit 12, a sustain up switch, and a sustain down voltage source ( 14).

The voltage charging unit 10 shown in FIG. 2 charges the absolute value of the sustain down voltage when the sustain down voltage is supplied to the sustain common electrode Z. Here, during the sustain down period, the sustain down voltage is applied to the sustain common electrode Z and the sustain up voltage is applied to the scan electrode Y, so that sustain discharge occurs. The sustain down voltage can be generated from the sustain down voltage source 14. For example, the sustain down voltage (-Vs) may be -200 volts. According to the present invention, the sustain up voltage can be the ground potential GND, and the sustain down voltage can be the negative potential -Vs as described above. 1 and 2, the sustain up voltage is a ground potential and the sustain down voltage is a negative potential, but the present invention is not limited thereto.

According to an embodiment of the present invention, the voltage charging unit 10 may be implemented with capacitors C1 and C2 and a sustain down switch susdn. The capacitors C1 and C2 are connected in series with the sustain up voltage GND and the sustain common electrode Z. In the case of FIG. 2, two capacitors C1 and C2 have been described, but the present invention is not limited thereto, and more capacitors can be provided.

The sustain down switch susdn is provided between the sustain common electrode Z and the sustain down voltage -Vs, and is turned on during the sustain down period.

According to another embodiment of the present invention, the voltage charging unit 10 may further provide a common switch (SC). The common switch SC is provided between the sustain up switch Susup and the sustain common electrode Z, and is turned on in the sustain down period or the sustain up period.

According to another embodiment of the present invention, the voltage charging unit 10 may further provide a diode (D1). The diode D1 has an anode and a cathode connected between the sustain up voltage GND and the capacitor C1, respectively.

On the other hand, the voltage supply unit 12 serves to supply the bias voltage generated by the voltage charged in the voltage charging unit 10 to the sustain common electrode Z in the bias period. Here, the bias period corresponds to at least one of a set down period of an address period and a reset period. For example, the voltage supply unit 12 may supply the bias voltage to the sustain common electrode Z only in the address period, unlike in FIG. 1, and in both the set down period and the address period of the reset period, as shown in FIG. 1. The bias voltage may be supplied to the sustain common electrode Z.

In this case, the bias voltage supplied from the voltage supply unit 12 to the sustain common electrode Z may be a voltage between the capacitors C1 and C2.

For the above operation, the voltage supply unit 12 may be implemented as a bias switch (BS). The bias switch BS is provided between the voltage charged in the capacitors C1 and C2 and the sustain common electrode Z. The bias switch BS is turned on in the bias period to sustain the voltage charged in the voltage charging unit 10 as the bias voltage. Output to the common electrode Z.

As shown in FIG. 2, the driving apparatus of the plasma display panel may further include a sustain up switch. The sustain up switch susup is provided between the sustain up voltage GND and the sustain common electrode Z, and is turned on in the bias period or the sustain up period.

According to the present invention, the driving apparatus of the plasma display panel may further include an energy recovery unit 5. The energy recovery unit 5 illustrated in FIG. 2 may be implemented with an external capacitor Cx, diodes D2 to D5, first and second energy recovery switches ER1 and ER2, and an inductor L. . The external capacitor Cx recovers and charges the voltage charged in the panel capacitor Cp. The inductor L is connected between the external capacitor Cx and the panel capacitor Cp. The first energy recovery switch ER1 supplies the recovered voltage charged in the external capacitor Cx to the panel capacitor Cp through the inductor L. The second energy recovery switch ER2 recovers the voltage charged in the panel capacitor Cp back to the external capacitor Cx through the inductor L.

The diode D2 has an anode and a cathode connected between the first energy recovery switch ER1 and the inductor L, respectively, and the diode D3 is between the panel capacitor Cp and the second energy recovery switch ER2. Has a positive electrode and a negative electrode, respectively. The diode D4 has a cathode and an anode connected between the sustain up voltage GND and one side of the inductor L, respectively. The diode D5 has a cathode and an anode connected between one side of the inductor L and the sustain down voltage (-Vs), respectively.

The energy recovery unit 5 having the configuration as described above recovers energy generated between the scan electrode Y and the common sustain electrode Z in the sustain period. At this time, the diodes D2 and D3 are provided between the first and second energy recovery switches ER1 and ER2 to limit the reverse current.

3 and 4 are views for explaining the operation of the driving apparatus of the plasma display panel according to the present invention shown in FIG.

Referring to FIG. 3, while the sustain up period, that is, the sustain up voltage GND is applied to the sustain common electrode Z, the sustain up switch susup and the common switch SC are turned on, and the sustain down switch ( susdn) and bias switch BS are turned off. Therefore, the sustain up voltage GND may be applied to the sustain common electrode Z.

Further, in the sustain down period, that is, while the sustain down voltage (-Vs) is applied to the sustain common electrode Z, the common switch SC and the sustain down switch susdn are turned on, and the sustain up switch susup. And the bias switch BS is turned off. Thus, a current path leading to the sustain down voltage (-Vs) is formed in the arrow direction 30 via the diode D1, the capacitors C1 and C2, the common switch SC, and the sustain down switch susdn. .

As a result, the sustain up voltage GND or the sustain down voltage −Vs may be applied to the sustain common electrode Z by the on and off operations of the sustain up and down switches susdn and susdn as described above. .

During such sustain operation, in a situation where the sustain down voltage (-Vs) is applied to the sustain common electrode Z in the sustain down period, the absolute value of the sustain down voltage (-Vs) at the capacitors C1 and C2 ( Vs) can be charged. Here, the voltage charged in the capacitor C2 can be used as the bias voltage.

Referring to FIG. 4, in the bias period, the sustain up switch susup and the bias switch BS are turned on, and the common switch SW and the sustain down switch susdn are turned off in the bias period. Accordingly, a current path leading to the panel capacitor Cp through the ground potential GND, the sustain up switch susup, the capacitor C2, and the bias switch BS, which are the sustain up voltage, is formed in the arrow direction 40. Therefore, the voltage V ₂ charged in the capacitor C2 may be applied to the sustain common electrode Z as the bias voltage Vbias. That is, the range of the bias voltage may be expressed as Equation 1 below, and the bias voltage may be expressed as Equation 2 shown below.

As can be seen from Equation 2, varying the capacitances of the capacitors C1 and C2 can change the level of the bias voltage. To this end, the capacitances of the capacitors C1 and C2 may be varied externally. That is, it can be seen from the above Equation 2 that the bias voltage Vbias can be determined by the ratio between the capacitors C1 and C2.

As described above, the driving apparatus of the plasma display panel according to the present invention can supply the bias voltage to the sustain common electrode during the bias period by using only a few capacitors, without using a separate bias voltage source, thereby reducing manufacturing costs. It has an effect that can be made.

Claims (11)

A voltage charging unit configured to charge an absolute value of the sustain down voltage when a sustain down voltage is supplied to the sustain common electrode; And And a voltage supply unit configured to supply a bias voltage generated by the charged voltage to the sustain common electrode in the bias period in the voltage charging unit. The method of claim 1, wherein the voltage charging unit Capacitors connected in series with a sustain up voltage and the sustain common electrode; And And a sustain down switch provided between the sustain common electrode and the sustain down voltage and turned on during the sustain down period. The method of claim 2, wherein the voltage supply unit And a bias switch provided between the voltage charged in the capacitors and the sustain common electrode, the bias switch being turned on in the bias period to output the charged voltage as the bias voltage to the sustain common electrode. The driving device of the plasma display panel. The apparatus of claim 3, wherein the plasma display panel is driven. And a sustain up switch provided between the sustain up voltage and the sustain common electrode and turned on in the bias period or the sustain up period. The method of claim 4, wherein the voltage charging unit And a common switch provided between the sustain up switch and the sustain common electrode, turned on in the sustain up period or the sustain down period, and turned off in the bias period. drive. The apparatus of claim 3, wherein the bias voltage is determined by a ratio between the capacitors as a voltage between the capacitors. The apparatus of claim 1, wherein the bias period corresponds to an address period. The apparatus of claim 1, wherein the bias period corresponds to a set down period of a reset period. The apparatus of claim 2, wherein the sustain up voltage is a ground potential, and the sustain down voltage is a negative potential. The method of claim 2, wherein the voltage charging unit And a diode having a cathode and an anode connected between the sustain up voltage and the capacitors, respectively. The apparatus of claim 2, wherein the capacitances of the capacitors are variable.

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