KR100764662B1 - Plasma display device and driving method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device and a driving method thereof, comprising a first switch for applying a positive external power source to a panel, a capacitor charged with a current as the first switch is conducted, and complementary to the first switch. And second and third switches for discharging current from the panel and capacitor as they are conducted, forming a sustain pulse of a half-sustain drive type using a single power supply and Circuit efficiency can be increased by reducing the applied voltage.

Plasma Display Panel, Half Sustain, Sustain

Description

Plasma display panel device and the operating method of the same}

1 is a diagram showing the structure of a plasma display panel;

2 is a view showing a driving waveform applied to drive a plasma display panel;

3 is a view showing a plasma display panel driving circuit according to the prior art;

4 is a view showing a plasma display device according to the present invention;

5 is a diagram showing a plasma display panel driving circuit according to the present invention;

6 is a diagram showing on / off timing of a switch provided in the plasma display panel driving circuit according to the present invention;

7 is a view showing an embodiment of a plasma display panel driving circuit according to the present invention;

8A to 8B are diagrams showing current paths of the plasma display panel according to the present invention.

<Explanation of symbols on main parts of the drawings>

Ysus_up: first switch Ysus_gnd: second switch

Ysus_dn: third switch C1: capacitor

Cp: Panel Capacitor

The present invention relates to a plasma display device and a method of driving the same, and in particular, the circuit efficiency can be improved by reducing the number of switches used to form a sustain pulse and the stress applied to the switch by a half sustain driving method using a single power supply. A plasma display device and a driving method thereof.

A plasma display panel is a display device in which vacuum ultraviolet rays (VUV) generated by discharging gas inside a panel collide with phosphors inside the panel to generate light. As shown in FIG. 1, the plasma display panel includes a front substrate A and a rear substrate B. As shown in FIG.

The front substrate A includes a scan electrode 1 and a sustain electrode 2 sequentially formed, a dielectric layer 3 stacked on the scan electrode and the sustain electrode, and a dielectric protective layer 4 formed on the dielectric layer. )

The scan electrode 1 and the sustain electrode 2 each have a relatively wide width and transparent electrodes 1a and 2a made of a transparent electrode material (ITO) to transmit visible light, and have a relatively narrow width. It is composed of bus electrodes 1b and 2b made of a metallic material provided to compensate for sheet resistance of the electrode.

When a driving signal for driving the plasma display panel is supplied to the scan electrode 1 and the sustain electrode 2, wall charges are accumulated in the dielectric layer 3, and the dielectric layer protective film 4 is formed by sputtering the dielectric layer ( 3) prevent damage and increase the emission efficiency of secondary electrons.

An address electrode 6 is formed on the rear substrate B so as to be orthogonal to the scan electrode 1 and the sustain electrode 2, and a dielectric layer 8 in which wall charges are accumulated on the address electrode is sequentially formed.

On the dielectric layer 8, the partition 7 partitioning the discharge space and the side surface of the partition and the bottom surface of the discharge space are excited by the ultraviolet rays generated by the discharge and are visible in any one of red, green or blue. Phosphor 9 for generating light is formed.

The plasma display panel displays a screen by discharging the plurality of address electrodes X arranged in the column direction and the plurality of scan electrodes Y and the sustain electrodes Z arranged in the row direction.

As shown in FIG. 2, the driving waveform includes a reset period R, an address period A, and a sustain period S. During the reset period, a setup reset signal R_up and a set down reset signal R_dn are generated. Supplied continuously.

When the setup reset signal R_up is supplied, reset discharge is generated between the scan electrode Y and the sustain electrode Z, and wall charges are accumulated in the dielectric layers on the scan electrode and the sustain electrode, and the set-down reset signal R_dn is generated. When supplied, the wall charge inside the discharge cell is erased to secure an operating margin of the driving circuit.

During the address period A, a data pulse having a positive polarity is applied to the address electrode X according to the image data, and a scan of negative polarity opposite to the data pulse is applied to the scan electrode Y. The pulse is supplied, and in the case of the cell to which the data pulse is applied, an address discharge occurs due to the voltage difference between the data pulse and the scan pulse.

During the sustain period S, a sustain pulse is alternately supplied to the scan electrode Y and the sustain electrode Z. When a sustain pulse is supplied to the cell where the address discharge is generated, the sustain discharge is generated and the screen is displayed.

The difference between the high potential voltage and the low potential voltage of the sustain pulse supplied to the scan electrode Y or the sustain electrode Z during the sustain period S is referred to as the sustain voltage Vs, which is the high potential voltage of the sustain pulse. When the level and the low potential voltage level is half of the sustain voltage (Vs / 2), this is called half sustain driving method.

The low potential voltage of the sustain pulse has a negative voltage rather than a ground voltage, that is, a ground level voltage, and the magnitude of the voltage corresponds to half (Vs / 2) of the sustain voltage.

As shown in FIG. 2, when looking at the reset signal applied to the scan electrode Y during the reset period R, the setup reset signal R_up is about half the sustain voltage Vs based on the ground level GND. / 2) after the rise, rises about 100V to 150V while taking the form of a ramp waveform. In the case of the set-down reset signal R_dn, the voltage decreases to about half of the sustain voltage (Vs / 2) and then decreases in the form of a ramp waveform around -300V.

The scan voltage Vsc is applied to the scan electrode Y during the address period A. The scan voltage is applied while the scan electrode is at the lowest voltage level (−Vy) of the set-down reset signal R_dn.

In this case, when a data pulse dp corresponding to the image data is applied to the address electrode X, a scan pulse is applied to the scan electrode Y opposite to the data pulse. When the scan pulse is applied, the scan electrode is applied. Voltage decreases to -Vy.

When the sustain period S starts, a sustain pulse is applied alternately to the scan electrode Y and the sustain electrode Z. The sustain pulse rises by Vs / 2 in the positive polarity direction and falls by Vs / 2 in the negative polarity direction based on the ground level GND.

In the half sustain driving method, wall charges are formed on the scan electrode (Y) and the sustain electrode (Z), similarly to performing sustain discharge by repeatedly raising / falling the sustain pulse from the ground voltage level to the sustain voltage level.

In addition, an electric field formed between the scan electrode and the address electrode X or between the sustain electrode and the address electrode during discharge between the scan electrode Y and the sustain electrode Z during the sustain period S is weaker than before. And the efficiency is improved.

In order to drive the plasma display panel using the half sustain driving method, a voltage source for applying the positive sustain voltage (Vs / 2) and the negative sustain voltage (-Vs / 2) should be separately provided.

If there is a separate voltage source for supplying the positive sustain voltage (Vs / 2) and the negative sustain voltage (-Vs / 2), not only the power supply configuration for supplying power to the plasma display panel is complicated, but also the power supply configuration The cost to increase.

Therefore, it is necessary to construct a circuit for applying the sustain pulse by supplying the positive sustain voltage (Vs / 2) and the negative sustain voltage (-Vs / 2) using a single power supply.

As shown in FIG. 3, in order to supply a sustain pulse (Vs / 2) and a negative sustain voltage (-Vs / 2) using the same power source, a sustain pulse is applied to the scan electrode (Y). The first driver 10 and the second driver 20 for applying a sustain pulse to the sustain electrode Y are provided.

The first driving unit 10 is turned on at the same time and the first to second switches (S1, S2) for supplying a positive external power supply (Vs / 2) to the panel (Cp), and the first The first capacitor C1 charged as the second to second switches are turned on, and the third to fourth switches that are turned on when the first to second switches are turned off to reduce the voltage of the panel. S3 and S4 are provided.

An external power supply is connected to one end of the first switch S1 to apply a positive power supply Vs / 2 from the outside. The third switch and the fourth switch S3 and S4 are connected in parallel, and the first capacitor C1 is also connected in parallel with the third switch to charge the current flowing through the first switch S1. .

The second drive unit 20 also has the same configuration as the first drive unit. That is, the sixth to seventh switches S6 and S7 which are turned on at the same time and supply the external external power Vs / 2 having positive polarity to the panel Cp, and the sixth to seventh switches are turned on. And the second capacitor C2 charged as the second capacitor C2 and the eighth to ninth switches S8 and S9 which are turned on when the sixth to seventh switches are turned off to reduce the voltage of the panel. It is provided.

When the sustain period S starts, the first to second switches S1 and S2 are turned on to supply the positive sustain voltage Vs / 2 to the panel Cp, so that the scan electrode Y has a high potential. It will have a sustain voltage level. At this time, the sixth to seventh switches S6 and S7 are turned on so that a negative sustain voltage (-Vs / 2) is supplied to the sustain electrode Z so that the sustain electrode has a low potential sustain voltage level. do.

When the third to fourth switches S3 and S4 are turned on, the voltage of the panel Cp decreases while the first capacitor is turned on while the first to second switches S1 and S2 are turned on. The voltage charged in (C1) exits through the third to fourth switches, and a negative sustain voltage (-Vs / 2) is applied to the scan electrode (Y).

At this time, the eighth to ninth switches S8 and S9 are turned on, and a positive sustain voltage Vs / 2 is applied to the sustain electrode Z, and at the same time, Vs / 2 to the second capacitor C2. As much voltage is charged.

In this case, the first driving unit 10 and the second driving unit 20 each use five switches to apply a sustain pulse to the scan electrode Y and the sustain electrode Z.

Compared to the conventional two to three switches used in the driving unit for applying the sustain pulse, the cost required for the circuit configuration is increased because more than two switches are required for half sustain driving using a single power supply. There is this.

In addition, as the number of switches used increases, the on / off adjustment of the switches becomes more complicated, so that the gate drive stage configuration of the FET used as the switch becomes more complicated, thereby reducing circuit reliability and efficiency.

In particular, as the number of switches through which the current passes increases, noise or distortion tends to occur on the waveform applied to the scan electrode Y or the sustain electrode Z, and thus, the half sustain drive using a single power supply is used. There is a problem that the number of switches must be reduced.

The present invention has been made to solve the above problems of the prior art, the purpose of which is to drive the plasma display panel by the half sustain driving method using a single power supply, the number of switches used for forming the sustain pulse and the switch The present invention provides a plasma display device and a method of driving the same, which can reduce circuit stress and improve circuit reliability.

According to an embodiment of the present invention, a plasma display device includes a first switch for applying a positive external power source to a panel, a capacitor charged with a current as the first switch is turned on, and complementary with the first switch. And second and third switches for discharging current from the panel and the capacitor as they are electrically operated.

A backflow preventing device is connected between the first switch and the capacitor and between the capacitor and the third switch to prevent a backflow of a current formed by a switch on / off.

The apparatus may further include an energy recovery unit including at least one switch and an inductor for recovering current of the panel during the sustain period, wherein the energy recovery unit is connected between the first switch and the second switch.

In the method of driving the plasma display apparatus, the first switch is turned on, the second and third switches are turned off to form the highest voltage of the sustain pulse, and the current is discharged from the panel to discharge the lowest voltage of the sustain pulse. And a first switch is turned off to form a second switch, and a second and third sustain switch are turned on.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 4 is a diagram showing a plasma display panel driving circuit according to the present invention, FIG. 5 is a diagram showing on / off timing of a switch provided in the plasma display panel driving circuit according to the present invention, and FIG. The embodiment of the plasma display panel driving circuit is shown in FIG.

As shown in FIG. 4, the plasma display panel includes a plurality of address electrodes X arranged in a column direction, a plurality of scan electrodes Y and a sustain electrode Z arranged in a row direction. . The scan electrode is formed corresponding to each sustain electrode, and one end of the sustain electrode is connected to each other, and the same voltage is applied thereto.

The plasma display panel is formed by bonding a front panel on which the scan electrode Y and the sustain electrode Z are alternately horizontally formed, and a back panel on which the address electrode X is formed, wherein the scan electrode and the sustain electrode and the address are joined. The electrodes are disposed to face each other so that the discharge spaces intersect vertically, and the discharge space at the intersection of the scan electrode and the sustain electrode and the address electrode forms a basic discharge cell.

In order to drive the plasma display panel, the data driver 110 applies data to the address electrodes X1 to Xm, the scan driver 120 to drive the scan electrodes Y1 to Yn, and the sustain electrode Z. And a sustain driver 120 for driving the controller and a controller 140 for controlling the drivers 110 to 130.

The data driver 110 samples and latches data in response to a timing control signal from the controller 140, and then supplies the data to the address electrodes X1 to Xm (hereinafter, X).

The scan driver 120 supplies scan pulses and sustain pulses to the scan electrodes Y1 to Yn (hereinafter referred to as Y) under the control of the controller 140, and the sustain driver 130 controls the controller 140. The control unit alternately operates with the scan driver 120 to supply a sustain pulse to the sustain electrode Z.

The control unit 140 receives a vertical / horizontal synchronization signal and a clock signal to generate timing control signals CTRX, CTRY, and CTRZ required for each of the driving units 110 to 130, and the driving unit corresponding to the timing control signal ( 110 to 130 to control the driving unit.

When the plasma display panel is driven, the sustain pulse generated by the scan driver 120 or the sustain driver 130 during the sustain period is negative sustain voltage level (-Vs / 2) and positive sustain voltage level (Vs / Switching to 2) to form a sustain pulse is called a half sustain driving method.

This is because the conventional sustain pulse was driven by full swing from the ground voltage level (GND) to the sustain voltage (Vs), whereas the highest voltage level of the sustain pulse is half of the sustain voltage (Vs / 2). The lowest voltage level is about half the sustain voltage below the ground voltage level.

As described above, when the half sustain driving method is used, the amount of wall charges formed on the scan electrode (Y) and the sustain electrode (Z) is the same for sustain discharge, while the scan electrode is discharged between the scan electrode and the sustain electrode. And the strength of the electric field formed between the address electrode X or the sustain electrode and the address electrode can be reduced.

In the case of sustain discharge, if the intensity of the electric field formed between the scan electrode Y and the address electrode X or between the sustain electrode Z and the address electrode increases, the sustain discharge generated between the scan electrode and the sustain electrode may be weakened. Therefore, when the half sustain driving method is used as described above, the driving of the plasma display panel is more stable.

In this case, since the same voltage having the opposite polarity is used in the case of the highest voltage level (Vs / 2) and the lowest voltage level (-Vs / 2) of the sustain pulse, a circuit for applying the sustain pulse using a single power supply is used. The configuration of is possible.

To this end, as illustrated in FIG. 5, the scan driver 120 is electrically connected to the first switch Ysus_up for applying the external external power Vs / 2 to the panel Cp, and the first switch is connected to the scan driver 120. A first capacitor C1 charged with a current, and second and third switches Ysus_dn and Ysus_gnd operatively complementary to the first switch and conducting to discharge current from the panel and the first capacitor. It is configured by.

The first switch Ysus_up has a drain terminal connected to the positive external power supply Vs / 2, and the second switch Ysus_dn is connected to the same node n1 as the source of the first switch.

One end of the first capacitor C1 is connected to the same node n2 as the source terminal of the second switch Ysus_dn, and the drain terminal of the third switch Ysus_gnd and the other end of the first capacitor are the same node n3. ), And the third switch and the first capacitor are connected in parallel. In this case, the second and third switches are connected to ground.

When the first switch Ysus_up is turned on, a positive sustain voltage Vs / 2 is applied from the external power supply to the panel Cp via the first switch. At this time, a voltage equal to the sustain voltage Vs / 2 is charged to the first capacitor C1.

Accordingly, as shown in FIG. 6, the waveform output to the scan electrode Y rises from the negative sustain minimum voltage level (-Vs / 2) to the positive sustain maximum voltage level (Vs / 2). do.

After a predetermined time, when the first switch Ysus_up is turned off and the second to third switches Ysus_dn and Ysus_gnd are turned on, current flows out from the panel Cp, and the scan electrode Y is sustained to a maximum voltage. At the level (Vs / 2), the negative sustain voltage decreases to the lowest voltage level (-Vs / 2).

That is, when the third switch Ysus_gnd is turned on, one end n3 of the first capacitor C1 connected to the third switch has a ground voltage level, so that the other end n2 of the first capacitor has a negative polarity. It will be reduced to the lowest sustain voltage level (-Vs / 2). Accordingly, the sustain waveform applied to the scan electrode Y has a negative sustain minimum voltage level (-Vs / 2).

At this time, as the second and third switches Ysus_dn and Ysus_gnd are conducted, current discharged from the first capacitor C1 may flow to the first switch Ysus_up.

That is, since the voltage of the node n1 to which the first switch Ysus_up and the panel Cp are connected is higher than that of the first capacitor C1, when the second and third switches Ysus_dn and Ysus_gnd are conducted, Since current flows from the one capacitor to the first switch, the voltage applied to the sustain electrode Y cannot be lowered to the negative sustain minimum voltage level (-Vs / 2).

To prevent this, as the second and third switches Ysus_dn and Ysus_gnd are conducted between the first switch Ysus_up and the first capacitor C1, current discharged from the first capacitor is transferred to the first switch. A backflow prevention element is connected to prevent backflow into the apparatus.

The backflow prevention device may be implemented as a switch or a diode such as a FET. In the present specification, a description will be given of an embodiment in which a backflow prevention device is implemented using a diode, but the type of the backflow prevention device is not limited to this specification.

When a diode D1 (hereinafter referred to as a first diode) is used as a backflow prevention element, an anode of the first diode is connected to the first switch Ysus_up (n1), and a cathode is connected to one end of the capacitor (n3). .

In addition, the second to third switches Ysus_dn and Ysus_gnd are turned on to apply a waveform of the negative sustain voltage (-Vs / 2) to the scan electrode Y, so that the current from the first capacitor C1 is turned on. When is discharged, the current to the ground (GND) can be reversed.

In this case, the current path passing through the second switch Ysus_dn, the first capacitor C1, and the third switch Ysus_gnd from the panel Cp cannot be normally formed, and thus the normal sustain is performed to the scan electrode Y. The pulse is not applied.

In order to prevent this, as the second and third switches Ysus_dn and Ysus_gnd are conducted, a backflow preventing element is provided to prevent current flowing to the ground GND from flowing back to the first capacitor C1.

When a diode D2 (hereinafter referred to as a second diode) is used as the backflow prevention element, an anode is connected to one end n2 of the first capacitor C1 and a cathode is connected to a source terminal of the third switch Ysus_gnd. .

Here, the voltage stress of the first switch Ysus_up is Vs, and the voltage stress of the second to third switches Ysus_dn and Ysus_gnd is half of the voltage stress applied to the first switch (Vs / 2).

Therefore, when the circuit for sustain pulse application is configured as described above, not only the application of the positive and negative sustain voltages (Vs / 2 or -Vs / 2) can be applied using a single power supply but also used for the circuit configuration. The number of switches can be reduced.

Conventionally, five or more switches have been used to apply the positive and negative sustain voltages (Vs / 2 or -Vs / 2), but in the present invention, three switches are used to form a sustain pulse.

In addition, since the voltage stress applied to the switch is reduced while reducing the number of switches, it is possible to increase the stability of the circuit and to configure the circuit using a switch having a large breakdown voltage, thereby reducing the cost required for the circuit configuration.

The sustain driver 130 for applying the sustain pulse to the sustain electrode Z also has the same structure as the scan driver 120 as shown in FIG. 5.

That is, the sustain driver 130 includes a fourth switch Zsus_up for applying a positive external power source Vs / 2 to the panel Cp, and a second capacitor charged with current as the fourth switch is turned on. C2) and fifth and sixth switches Zsus_dn and Zsus_gnd that operate complementarily with the fourth switch and are electrically connected to discharge current from the panel and the second capacitor.

The fourth to sixth switches Zsus_up, Zsus_dn, and Zsus_gnd included in the sustain driver 130 operate opposite to the first to third switches Ysus_up, Ysus_dn, and Ysus_gnd.

That is, as shown in FIG. 6, when a positive sustain pulse Vs / 2 is applied to the scan electrode Y, a negative sustain pulse (-Vs / 2) is applied to the sustain electrode Z. Since the first to third switches (Ysus_up, Ysus_dn, Ysus_gnd) and the fourth to sixth switches (Zsus_up, Zsus_dn, Zsus_gnd) operate in reverse.

When the first switch Ysus_up is turned on and the second to third switches Ysus_dn and Ysus_gnd are turned off, a positive sustain pulse Vs / 2 is applied to the scan electrode Y.

On the contrary, when the fourth switch Zsus_up is turned off and the fifth to sixth switches Zsus_dn and Zsus_gnd are turned on, a negative sustain pulse (-Vs / 2) is applied to the sustain electrode Y. do.

Subsequently, when the first switch Ysus_up is turned off and the second to third switches Ysus_dn and Ysus_gnd are turned on, a negative sustain pulse (-Vs / 2) is applied to the scan electrode Y. On the contrary, when the fourth switch Zsus_up is turned on and the fifth to sixth switches Zsus_dn and Zsus_gnd are turned off, a positive sustain pulse Vs / 2 is applied to the sustain electrode Z. do.

As such, when the on / off timings of the first to third switches Ysus_up, Ysus_dn, and Ysus_gnd and the fourth to sixth switches Zsus_up, Zsus_dn, and Zsus_gnd are adjusted, the scan electrode Y and the sustain electrode Z are adjusted. It is possible to apply a sustain pulse.

In this case, the waveforms of the sustain pulses applied to the scan electrode Y and the sustain electrode Z are shown in FIG. It is.

As described above, when the number of switches constituting the scan driver 120 and the sustain driver 130 is reduced, loss of waveforms applied to the scan electrode Y and the sustain electrode Z can be reduced.

When the current flows from the external power supply Vs / 2 to the panel Cp or while the current flows from the panel Cp to the ground GND, the number of switches present on the current path increases. Voltage drops occur, resulting in current losses.

In the present invention, since the number of switches required to configure the scan driver 120 and the sustain driver 130 has been reduced by more than half compared to the prior art, since the current lost during the switch is reduced, waveform distortion is reduced and stable. Not only is it possible to apply a sustain pulse, but it also increases circuit efficiency due to reduced losses.

In addition, since the switch element drive for adjusting the on / off of the switch is simplified, the cost and circuitry for the switch element drive stage configuration is reduced, thereby increasing the circuit reliability.

In general, an energy recovery unit ER is provided in the scan driver 120 or the sustain driver 130 in order to reduce power consumption by recovering reactive current when a sustain waveform is applied and using a sustain pulse.

Here, an example in which an energy recovery unit ER is connected to the scan driver 120 will be described. However, the energy recovery unit is connected to the sustain driver 130 in the same manner as the scan driver.

As shown in FIG. 5, the energy recovery unit ER is connected between n1 between the first switch Ysus_up and the second switch Ysus_dn.

The energy recovery unit ER includes an inductor L forming a resonance current, and one or more energy recovery switches Er_up and Er_dn connected to the inductor to recover reactive current from the panel.

The energy recovery switches Er_up and Er_dn include a first recovery switch Er_up for recovering energy stored in the panel Cp, and a second recovery switch Er_dn for applying the recovered energy to the panel.

In this case, diodes D3 and D4 are connected to one ends of the energy recovery switches Er_up and Er_dn to prevent reverse flow of the resonance current.

Before turning on the first switch Ysus_up to apply the positive sustain voltage Vs / 2 to the scan electrode Y, the first recovered switch Er_up is turned on to resonate the recovered power. It is applied to the scan electrode.

At this time, due to the parasitic resistance existing on the current path and the voltage drop caused by the switch or diode, the recovered voltage does not resonate and thus does not apply exactly twice the voltage to the panel, and thus, after the first recovery switch Er_up is turned on The first switch Ysus_up is turned on.

When the first recovery switch Er_up is turned on, the scan electrode Y rises from the low potential sustain voltage (-Vs / 2) to rise near the high potential sustain voltage (Vs / 2), and the first switch When (Ysus_up) turns on one after another, it rises to the high potential sustain voltage (Vs / 2).

On the contrary, before turning on the second to third switches Ysus_dn and Ysus_gnd, the second recovery switch Er_dn is turned on to recover the voltage applied to the scan electrode Y to be used for the next sustain pulse. do.

As described above, when the scan driver 120 includes the energy recovery unit ER, the reactive current of the panel Cp may be recovered and reused when the sustain pulse is applied, thereby reducing power consumption by applying the sustain pulse.

Looking at the driving method of the plasma display device of the present invention configured as described above are as follows.

The first switch Ysus_up is turned on to form the highest voltage Vs / 2 of the sustain pulse, and the second and third switches Ysus_dn and Ysus_gnd are turned off, and current is discharged from the panel to sustain The first switch is turned off and the second and third sustain switches are turned on to form the lowest voltage (-Vs / 2) of the pulse.

That is, the first recovery switch Er_up is turned on to apply the sustain pulse rising from the negative sustain minimum voltage (-Vs / 2) to the positive sustain maximum voltage (Vs / 2) to the scan electrode Y. Turn on.

When the first recovery switch Er_up is conducted, a resonance current is formed between the first recovery switch and the inductor L as shown in FIG. 8A, and the resonance current is applied to the panel Cp (I1).

Subsequently, when the first switch Ysus_up is turned on, a current I2 flows from the external voltage source Vs / 2 to the panel Cp through the first switch, and the positive sustain maximum voltage is supplied to the scan electrode. (Vs / 2) is applied.

After a predetermined time, in order to apply a sustain pulse that falls from the positive sustain maximum voltage (Vs / 2) to the negative sustain minimum voltage (-Vs / 2) to the scan electrode Y, a second recovery switch ( Turn on Er_dn).

When the second recovery switch Er_dn is turned on, the reactive current is recovered from the panel Cp through the inductor L as illustrated in FIG. 8B (I3). Since the intermediate value between the highest voltage (Vs / 2) and the lowest voltage (-Vs / 2) of the sustain pulse is the ground level, even if the second recovery switch is connected to the ground (GND) even without a separate capacitor, a reactive current is required. May have the effect of recovering.

Thereafter, when the second to third switches Ysus_dn and Ysus_gnd are turned on, current flows from the panel Cp to the ground GND (I4), and a negative sustain voltage of negative polarity is applied to the scan electrode (Y). (-Vs / 2) is applied.

As described above, when the sustain pulse is applied using the first to third switches (Ysus_up, Ysus_dn, Ysus_gnd), in the half sustain driving method using a single power supply, the sustain pulse can be applied using fewer switches. Will be.

Reducing the number of switches not only simplifies the on / off control of the switch, but also reduces the distortion of the applied sustain pulse and increases the reliability since a more stable sustain pulse can be applied.

In addition, since the voltage stress applied to the switch is similar to the related art, a circuit configuration using fewer switches is possible without a large increase in voltage stress, thereby reducing circuit efficiency and manufacturing cost.

As described above, the plasma display device and the driving method thereof according to the present invention have been described with reference to the illustrated drawings. It is possible to apply within the scope of protection of the technical idea of the present invention by those skilled in the art.

The plasma display device and the driving method thereof according to the present invention configured as described above have a circuit which reduces the number of switches required for sustain pulse formation in driving the plasma display panel by a half sustain method using a single power source. This reduces the cost of configuration.

In addition, since the loss and waveform distortion generated when the sustain pulse is formed and the number of the switches are reduced, the switch is easily controlled, thereby improving circuit reliability and efficiency.

Claims (6)

A first switch, one end of which is connected to a positive external power source and the other end of which is directly connected to the panel; A capacitor charged as the first switch is turned on; Second and third switches operatively complementary to said first switch and discharging said panel and said capacitor as conductive; And And a backflow prevention element connected between the first switch and the capacitor to prevent current from flowing from the capacitor to the first switch when the second switch and the third switch are conducted. Plasma display device. The method of claim 1, wherein the reverse current prevention device And a diode having a cathode terminal connected to the other end of the first switch and an anode terminal connected to one end of the capacitor. In claim 1, And the second and third switches are connected to ground. In claim 3, And a backflow prevention device for preventing a current flowing to ground to flow back to the capacitor as the second and third switches are turned on. In claim 1, Further comprising an energy recovery unit having one or more switches and inductors for recovering the current of the panel during the sustain period, And the energy recovery unit is connected between the first switch and the second switch. In the method for driving a plasma display panel, The first switch is turned on and the second and third switches are turned off to form the highest voltage of the sustain pulse; And turning off the first switch so that the current is discharged from the panel to form the lowest voltage of the sustain pulse, and turning on the second and third sustain switches.

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