KR20110067228A - Plasma display apparatus and driving method thereof - Google Patents

Abstract

PURPOSE: A plasma display apparatus and a driving method thereof are provided to supply a sustain signal of different types to a plasma display panel by using an energy recovery circuit. CONSTITUTION: In a plasma display apparatus and a driving method thereof, a plasma display panel comprises a scan electrode and a sustain electrode. A first switch(S1) is arranged between a sustain voltage source and a scan electrode. A second switch(S2) is arranged between a positive sustain voltage source and a sustain electrode. A third switch(S3) is arranged between a first node and the ground. A fourth switch(S4) is arranged between a second node and the ground. A first inductor(L1) is arranged in parallel with the first switch. A second inductor(L2) is arranged in parallel with the second switch. A third inductor(L3) is arranged in parallel with the third switch. A fourth inductor(L4) is arranged in parallel with the fourth switch.

Description

Plasma display apparatus and driving method thereof

The present invention relates to a plasma display device and a driving method thereof.

The plasma display apparatus includes a plasma display panel.

The plasma display panel includes a phosphor layer formed in a discharge cell divided by a partition wall, and also includes a plurality of electrodes.

When the drive signal is supplied to the electrode of the plasma display panel, the discharge is generated by the drive signal supplied in the discharge cell. Here, when discharged by a drive signal in the discharge cell, the discharge gas filled in the discharge cell generates vacuum ultraviolet rays, and the vacuum ultraviolet light emits the phosphor formed in the discharge cell to emit visible light. Generate. The visible light displays an image on the screen of the plasma display panel.

The present invention proposes an improved energy recovery circuit capable of reducing the number of switching elements in an energy recovery circuit, and a plasma display device capable of supplying a sustain signal having a different sustain signal form to a plasma display panel through one energy recovery circuit. And a driving method thereof.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

One example of a plasma display device according to the present invention includes a plasma display panel including a scan electrode and a sustain electrode; A first switch disposed between the scan voltage and the sustain voltage source for supplying the positive sustain voltage; A second switch disposed between the positive sustain voltage source and the sustain electrode; A third switch disposed between the first node between the first switch and the scan electrode and the ground for supplying a ground level voltage GND; A fourth switch disposed between ground and a second node between the second switch and the sustain electrode; A first inductor disposed in parallel with the first switch between the first node and the sustain voltage source; A second inductor disposed in parallel with the second switch between the second node and the sustain voltage source; A third inductor disposed in parallel with the third switch between the first node and ground; And a fourth inductor disposed in parallel with the fourth switch between the second node and ground.

The plasma display device may include a first diode disposed in parallel with the first switch between the sustain voltage source and the first node to block a current flowing from the sustain voltage source to the first node via the first inductor; And a second diode disposed in parallel with the second switch between the sustain voltage source and the second node to block a current flowing from the sustain voltage source to the second node via the second inductor.

The plasma display apparatus may further include a third diode disposed in parallel with the third switch between the first node and the ground to block a current flowing from the first node to the ground through the third inductor; And a fourth diode disposed between the second node and the ground, the fourth diode blocking the current flowing from the second node to the ground through the fourth inductor.

Here, after the fourth switch is turned on during the first period of the sustain period of the subfield, the voltage of the scan electrode gradually rises by resonance with the third inductor from the negative sustain voltage to the positive sustain voltage, The voltage of the sustain electrode can maintain the ground level voltage.

In addition, when the fourth switch is turned on, the voltage of the scan electrode may drop without resonance from the ground level voltage to the negative sustain voltage, and the voltage of the sustain electrode may fall without resonance from the positive sustain voltage to the voltage at the ground level. have.

In addition, the voltage difference between the scan electrode and the sustain electrode may be equal to the magnitude of the negative sustain voltage when the voltage of the scan electrode and the sustain electrode drops by turning on the fourth switch.

Further, during the second period subsequent to the first period, the first switch is turned on while the fourth switch is kept turned on, so that the voltage of the scan electrode maintains the positive sustain voltage, and the voltage of the sustain electrode is The ground level voltage can be maintained.

Here, during the third period after the second period, after the third switch is turned on, the voltage of the scan electrode maintains the voltage at the ground level, and the voltage of the sustain electrode is set from the negative sustain voltage to the positive sustain voltage. It may rise gradually due to resonance with the inductor.

In addition, as soon as the third switch is turned on, the voltage of the scan electrode drops without resonance from the positive sustain voltage to the ground level voltage, and the voltage of the sustain electrode can fall from the ground level voltage to the negative sustain voltage without resonance. have.

In addition, the voltage difference between the scan electrode and the sustain electrode may be equal to the magnitude of the positive sustain voltage when the voltage of the scan electrode and the sustain electrode drops by turning on the third switch.

In addition, during the fourth period following the third period, the second switch is turned on while the third switch is kept turned on, so that the voltage of the scan electrode maintains the voltage at the ground level, and the sustain electrode is positive. The sustain voltage can be maintained.

In addition, the first to fourth switches may be turned off during a period between the second period and the third period.

In addition, the first to fourth switches may be turned off during the period between the fourth period and the first period.

In addition, during the fifth period of the sustain period of the subfield, after the first switch is turned on, the voltage of the scan electrode is maintained at the positive sustain voltage, and the voltage of the sustain electrode is at ground level starting from twice the voltage of the positive sustain voltage. The voltage may be gradually decreased by resonance with the second inductor.

Here, the moment the first switch is turned on, the voltage of the scan electrode rises without resonance from the ground level voltage to the positive sustain voltage, and the voltage of the sustain electrode is twice the voltage from the positive sustain voltage to the positive sustain voltage. Can rise without resonance.

In this case, the voltage difference between the scan electrode and the sustain electrode may be equal to the magnitude of the negative sustain voltage when the voltage of the scan electrode and the sustain electrode increases by turning on the first switch.

Further, during the sixth period following the fifth period, the fourth switch is turned on while the first switch is kept turned on, so that the voltage of the scan electrode maintains the positive sustain voltage, and the voltage of the sustain electrode is The ground level voltage can be maintained.

Further, during the seventh period after the sixth period, after the second switch is turned on, the voltage of the scan electrode is gradually increased by resonance with the first inductor from twice the voltage of the positive sustain voltage to the voltage of the ground level. The voltage of the sustain electrode is lowered and the positive sustain voltage can be maintained.

Here, the moment the second switch is turned on, the voltage of the scan electrode rises without resonance from the positive sustain voltage voltage to twice the voltage of the positive sustain voltage, and the voltage of the sustain electrode increases from the ground level voltage to the positive sustain voltage. Can rise without resonance.

In addition, the voltage difference between the scan electrode and the sustain electrode may be equal to the magnitude of the positive sustain voltage when the voltage of the scan electrode and the sustain electrode increases by turning on the second switch.

In addition, during the eighth period subsequent to the seventh period, the third switch is turned on while the second switch is kept turned on, so that the voltage of the scan electrode maintains the voltage of the ground level, and the voltage of the sustain electrode is The positive sustain voltage can be maintained.

In addition, the first to fourth switches may be turned off during the period between the sixth and seventh periods.

In addition, the first to fourth switches may be turned off during the period between the eighth period and the fifth period.

In addition, the first inductor and the second inductor may have the same inductance.

In addition, the third inductor and the fourth inductor may have the same inductance.

Also, inductances of the first inductor and the second inductor may be smaller than inductances of the third inductor and the fourth inductor.

In addition, a period in which resonance occurs by the first inductor and the second inductor may be shorter than a period in which resonance occurs in the third inductor and the fourth inductor.

In addition, resonance using the first inductor and the second inductor may occur when the number of discharge cells turned on in the plasma display panel is large.

In addition, resonance using the third inductor and the fourth inductor may occur when the number of discharge cells turned on in the plasma display panel is small.

In addition, the driving method of the plasma display apparatus according to the exemplary embodiment of the present invention supplies at least one of the first sustain signal and the second sustain signal to the scan electrode and the sustain electrode during the sustain period of the subfield, and the first sustain signal is negative. Gradually rises from the sustain voltage to the positive sustain voltage, maintains the positive sustain voltage, drops from the positive sustain voltage to the ground level voltage, maintains the ground level voltage, and maintains the ground level voltage from the negative sustain voltage. Down to voltage,

 The second sustain signal rises from the ground level voltage to the positive sustain voltage, maintains the positive sustain voltage, rises from the positive sustain voltage to twice the voltage of the positive sustain voltage, and from the positive sustain voltage to the ground level. It gradually decreases to the voltage of, and maintains the ground level voltage.

Here, in the first sustain signal, the magnitude of the rising slope gradually increasing from the negative sustain voltage to the positive sustain voltage is determined by the falling slope of the signal falling from the positive sustain voltage to the voltage of the ground level or the negative voltage from the ground level voltage. It may be less than the magnitude of the falling slope of the signal falling to the polar sustain voltage.

Also, in the first sustain signal, the period of maintaining the ground level may be longer than the period of maintaining the positive sustain voltage.

Further, in the first sustain signal, the period of maintaining the ground level may gradually increase from the negative sustain voltage to the positive sustain voltage, and may be the same as the period of maintaining the positive sustain voltage.

Here, while the voltage of the first sustain signal supplied to the scan electrode gradually rises from the negative sustain voltage to the positive sustain voltage, and while maintaining the positive sustain voltage, the voltage of the first sustain signal supplied to the sustain electrode is The ground level voltage can be maintained.

In addition, in the second sustain signal, the magnitude of the falling slope gradually decreasing from twice the voltage of the positive sustain voltage to the voltage at the ground level is the rising slope or the positive sustain voltage rising from the ground level voltage to the positive sustain voltage. It may be less than the magnitude of the rising slope rising from the voltage up to twice the voltage of the positive sustain voltage.

Further, in the second sustain signal, the period of maintaining the positive sustain voltage may be longer than the period of maintaining the voltage of the round level.

Also, in the second sustain signal, the period for maintaining the positive sustain voltage may be the same as the period for gradually decreasing from twice the voltage of the positive sustain voltage to the voltage at the ground level and maintaining the voltage at the ground level.

Further, while the voltage of the second sustain signal supplied to the scan electrode maintains the positive sustain voltage, the second sustain signal supplied to the sustain electrode drops from a voltage twice the positive sustain voltage to a voltage at ground level, The ground level voltage can be maintained.

In addition, while the voltage of the second sustain signal supplied to the scan electrode drops from the voltage twice the positive sustain voltage to the voltage at the ground level, and maintains the voltage at the ground level, the second sustain signal supplied to the sustain electrode is maintained. The voltage can maintain a positive sustain voltage.

In addition, the period in which the first sustain signal gradually rises from the negative sustain voltage to the positive sustain voltage may be longer than the period in which the second sustain signal falls from the voltage twice the positive sustain voltage to the voltage at the ground level.

In addition, the period of the first sustain signal may be longer than that of the second sustain signal.

In addition, the driving method of the plasma display apparatus according to another exemplary embodiment of the present invention supplies a first sustain signal to the scan electrode and the sustain electrode in the case of the first subfield having a low gray scale weight in the same frame, In the case of the second subfield having a high gray scale weight, a second sustain signal is supplied, and the first sustain signal gradually rises from the negative sustain voltage to the positive sustain voltage, maintains the positive sustain voltage, and maintains the positive sustain voltage. At the ground level, maintains the ground level voltage, falls from the ground level voltage to the negative sustain voltage, and the second sustain signal rises from the ground level voltage to the positive sustain voltage, Maintain sustain voltage, positive polarity from sustain voltage It rises to twice the voltage of the stain voltage, and the positive sustain voltage to the voltage gradually drops from the ground level, and maintains the voltage of the ground level.

In addition, the driving method of the plasma display apparatus according to another embodiment of the present invention supplies a first sustain signal to the scan electrode and the sustain electrode in a first frame having a low average power level (APL), and average power level than the first frame. If (APL) is high, the second sustain signal is supplied, and the first sustain signal gradually rises from the negative sustain voltage to the positive sustain voltage, maintains the positive sustain voltage, and maintains the ground level at the positive sustain voltage. Drop to the voltage, maintain the ground level voltage, fall from the ground level voltage to the negative sustain voltage, and the second sustain signal rises from the ground level voltage to the positive sustain voltage and maintains the positive sustain voltage From the positive sustain voltage to twice the positive sustain voltage. Rises, the positive polarity and the sustain voltage to the voltage gradually drops from the ground level, and maintains the voltage of the ground level.

In addition, the driving method of the plasma display apparatus according to still another embodiment of the present invention supplies a first sustain signal to the scan electrode and the sustain electrode when the number of discharge cells turned on in the same subfield is small, and turns on the discharge cells. The second sustain signal is supplied when the number is large, and the first sustain signal gradually rises from the negative sustain voltage to the positive sustain voltage, maintains the positive sustain voltage, and maintains the positive sustain voltage at ground level. To the ground level, maintains the ground level voltage, falls from the ground level voltage to the negative sustain voltage, and the second sustain signal rises from the ground level voltage to the positive sustain voltage and maintains the positive sustain voltage. , Twice the positive sustain voltage to the positive sustain voltage It rises to the voltage, and gradually falls from the positive sustain voltage to the ground level voltage, and maintains the ground level voltage.

The plasma display device and the driving method thereof according to the present invention propose an improved energy recovery circuit which reduces the number of switching elements of the energy recovery circuit, thereby reducing manufacturing costs and providing a more stable sustain signal.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the following will describe a preferred embodiment of the present invention, but the technical idea of the present invention is not limited thereto and may be variously modified and modified by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view for explaining a plasma display device according to the present invention.

As shown in FIG. 1, the plasma display apparatus may include a plasma display panel 100 and a driver 110.

The plasma display panel 100 includes scan electrodes Y1 to Yn and sustain electrodes Z1 to Zn that are parallel to each other, and crosses the scan electrodes Y1 to Yn and the sustain electrodes Z1 to Zn. X1 to Xm). In addition, the plasma display panel 100 may implement an image in a frame including a plurality of subfields.

The driving unit 110 supplies a driving signal to at least one of the scan electrodes Y1 to Yn, the sustain electrodes Z1 to Zn, or the address electrodes X1 to Xm of the plasma display panel 100, thereby providing a plasma display panel 100. The image may be implemented on the screen.

Here, in FIG. 1, only the case where the driving unit 110 is formed in one board form is illustrated, but in the present invention, the driving unit 110 is divided into a plurality of board forms according to electrodes formed on the plasma display panel 100. It is also possible to lose. For example, the driver 110 may include a first driver (not shown) for driving the scan electrodes Y1 to Yn of the plasma display panel 100 and a second driver (not shown) for driving the sustain electrodes Z1 to Zn. H) and a third driver (not shown) for driving the address electrodes X1 to Xm.

In the plasma display apparatus according to the present invention, the number of switching elements of the energy recovery circuit for supplying a sustain signal to the sustain electrodes Z1 to Zn and the scan electrodes Y1 to Yn during the sustain period of the subfield in the driving unit 110 is determined. A new type of sustain signal is provided to the sustain electrodes Z1 to Zn and the scan electrodes Y1 to Yn during the sustain period of the subfield to provide an improved energy recovery circuit which can be reduced. To provide.

2 is a view for explaining an example of the structure of a plasma display panel in the plasma display device shown in FIG.

Referring to FIG. 2, the plasma display panel 100 includes a rear substrate 211 on which a plurality of second electrodes 213 and X intersect the plurality of first electrodes 202 (Y) and 203 (Z). It may include.

Here, the first electrodes 202 and 203 may include scan electrodes Y1 to Yn 202 and Y that are parallel to each other, and sustain electrodes Z1 to Zn 203 and Z, and the second electrode 211 is provided. Can be referred to as address electrodes X1 to Xm.

Scan electrodes Y1 to Yn (202 and Y) and sustain electrodes Z1 are formed on the front substrate 201 where the scan electrodes Y1 to Yn (202 and Y) and the sustain electrodes Z1 to Zn (203 and Z) are formed. The upper dielectric layer 204 which limits the discharge current of ˜Zn (203, Z) and insulates between the scan electrodes (Y1-Yn) (202, Y) and the sustain electrodes (Z1-Zn) (203, Z). Can be deployed.

A protective layer 205 may be formed on the front substrate 201 where the upper dielectric layer 204 is formed to facilitate discharge conditions. The protective layer 205 may include a material having a high secondary electron emission coefficient, such as magnesium oxide (MgO) material.

The address electrodes X1 to Xm 213 and X are formed on the rear substrate 211, and the address electrodes X1 to X are formed on the rear substrate 211 on which the address electrodes X1 to Xm 213 and X are formed. A lower dielectric layer 215 may be formed to cover Xm 213 and X and insulate address electrodes X1 to Xm 213 and X.

On top of the lower dielectric layer 215, a partition space 212, such as a stripe type, a well type, a delta type, a honeycomb type, etc., is formed on the discharge space, that is, to partition the discharge cells. Can be. Accordingly, a first discharge cell emitting red (R) light, a second discharge cell emitting blue (B) light, and green (between the front substrate 201 and the rear substrate 211). Green: G) A third discharge cell or the like that emits light can be formed.

The partition 212 may include a first partition 212b and a second partition 212a, and a height of the first partition 212b and a height of the second partition 212a may be different from each other.

On the other hand, in the discharge cells, the address electrodes X1 to Xm 213 may cross the scan electrodes Y1 to Yn 202 and the sustain electrodes Z1 to Zn 203. In other words, the discharge cells are formed at points where the address electrodes X1 to Xm 213 cross the scan electrodes Y1 to Yn 202 and the sustain electrodes Z1 to Zn 203.

A predetermined discharge gas may be filled in the discharge cell partitioned by the partition wall 212.

In addition, a phosphor layer 214 that emits visible light for image display may be formed in the discharge cells partitioned by the partition wall 212. For example, a first phosphor layer that generates red light, a second phosphor layer that generates blue light, and a third phosphor layer that generates green light may be formed.

The address electrodes X1 to Xm 213 formed on the rear substrate 211 may have substantially the same width or thickness, but the width or thickness inside the discharge cell is the width or thickness outside the discharge cell. It may be different from. For example, the width or thickness inside the discharge cell may be wider or thicker than that outside the discharge cell.

When a predetermined signal is supplied to at least one of the scan electrodes (Y1 to Yn) 202, the sustain electrodes (Z1 to Zn) 203, and the address electrodes (X1 to Xm) 213, discharge may occur in the discharge cells. have. As such, when discharge is generated in the discharge cell, ultraviolet rays may be generated by the discharge gas filled in the discharge cell, and the ultraviolet rays may be irradiated onto the phosphor particles of the phosphor layer 214. Then, a predetermined image may be displayed on the screen of the plasma display panel 100 by the phosphor particles irradiated with ultraviolet rays to emit visible light.

FIG. 3 is a diagram for explaining an example of an image frame for implementing gradation of an image.

Referring to FIG. 3, a frame for implementing gray levels of an image may include a plurality of subfields SF1 to SF8.

In addition, the plurality of subfields may include a sustain period for implementing gradation according to an address period and a number of discharges for selecting a discharge cell in which discharge will not occur or a discharge cell in which discharge occurs. It may include.

For example, in case of displaying an image with 256 gray levels, for example, one frame is divided into eight subfields SF1 to SF8 as shown in FIG. 3, and each of the eight subfields SF1 to SF8 is an address. It can include a period and a sustain period.

Alternatively, at least one subfield of the plurality of subfields of the frame may further include a reset period for initialization. In addition, at least one subfield of the plurality of subfields of the frame may not include a sustain period.

Meanwhile, the weight of the subfield may be set by adjusting the number of sustain signals supplied in the sustain period. That is, a predetermined weight can be given to each subfield using the sustain period. For example, the weight of each subfield is 2 ⁿ by setting the weight of the first subfield to 2 ⁰ and the weight of the second subfield to 2 ¹ (where n = 0, 1, 2, 3, 4, 5, 6, 7) can be set to increase the ratio. As described above, gray levels of various images may be realized by adjusting the number of sustain signals supplied in the sustain period of each subfield according to the weight in each subfield.

In FIG. 3, only one image frame is composed of eight subfields. However, the number of subfields constituting one image frame may be variously changed. For example, one video frame may be configured with 12 subfields from the first subfield to the twelfth subfield, or one video frame may be configured with 10 subfields.

In addition, in FIG. 3, subfields are arranged in an order of increasing weight in one image frame. Alternatively, subfields may be arranged in an order of decreasing weight in one image frame. Subfields may be arranged regardless.

4 is a view for explaining an example of a driving method of the plasma display device according to FIG. 1.

As shown in FIG. 4, the driver 110 may supply the rising ramp signal RU gradually rising from the ground level to the scan electrode Y during the setup period SU during the reset period RP of the subfield. Can be.

As such, when the rising ramp signal RU is supplied to the scan electrode Y in the set-up period SU of the subfield SF, a weak dark discharge is generated in the discharge cell by the rising ramp signal RU. ), That is, a setup discharge occurs. By this setup discharge, the distribution of wall charges can be uniform in the discharge cells. In FIG. 4, the rising ramp signal RU is supplied as an example in the setup period SU of the subfield SF. However, instead of the rising ramp signal RU, the ground level voltage GND is applied instead. Can be supplied.

In the set down period SD of the reset period RP of the subfield, the driving units 110 and 110 are supplied to the scan electrode Y with the falling ramp signal RD gradually falling at the ground level. In the discharge cell, a weak erase discharge, that is, a set-down discharge occurs. By this set-down discharge, wall charges such that address discharge can be stably generated can be uniformly retained in the discharge cells. In addition, the driving unit 110 may supply the sustain reference voltage ZB to the sustain electrode Z.

Next, in the address period AP of the subfield, the driving unit 110 supplies the first scan reference voltage YB to the scan electrode Y and supplies a plurality of scan signals SC that fall from the scan reference voltage YB. When the data signal is supplied by supplying the discharge cells, address discharge, which is a counter discharge, may occur.

In addition, when the scan signal SC is supplied to the scan electrode Y, the driver 110 supplies the data signal DATA to the address electrode X so as to correspond to the scan signal SC, thereby turning on the scan signal SC. The discharge cell to be turned on and the discharge cell to be turned off may be selected. Accordingly, in the discharge cells to which the data signal is supplied among the plurality of discharge cells, the voltage difference between the scan signal SC and the data signal DATA and the wall voltage due to the wall charges generated in the reset period RP are added to the data. The address discharge may be generated in the discharge cell to which the signal DATA is supplied.

In addition, the driving unit 110 supplies the sustain reference voltage ZB to the sustain electrode Z, and the scan electrode Y and the address electrode (Z) in the sustain electrode Z in the address period AP in which address discharge occurs. The address discharge can be made more effective between X).

Next, in the sustain period SP of the subfields SF1 and SF2, the driving unit 110 may have the first sustain signal SUS1 or the second sustain in the form of pulses different from the scan electrode Y and the sustain electrode Z. At least one of the signal SUS2 may be supplied.

As an example, FIG. 4 illustrates an example in which the first sustain signal SUS1 is supplied to the scan electrode Y and the sustain electrode Z. An example of supplying the second sustain signal SUS2 is illustrated in FIG. 6. An example in which the first sustain signal SUS1 and the second sustain signal SUS2 are supplied together is illustrated in FIGS. 8 to 10.

When such a sustain signal is supplied, the discharge cell selected by the address discharge is added with the wall voltage in the discharge cell and the sustain voltage VS of the sustain signals SUS1 and SUS2 and the scan electrode Y when the sustain signal is supplied. A sustain discharge, that is, a display discharge, may be generated between the sustain electrode and the sustain electrode Z.

Hereinafter, an example in which the first sustain signal SUS1 and the second sustain signal SUS2 are supplied will be described in more detail.

First, as shown in FIG. 4, the first sustain signal SUS1 supplied during the sustain period SP of the subfield gradually rises from the negative sustain voltage (-VS) to the positive sustain voltage VS. Maintains the positive sustain voltage VS, falls from the positive sustain voltage VS to the ground level voltage GND, maintains the ground level voltage GND, and starts from the ground level voltage GND. The voltage drops to the negative sustain voltage (-VS).

The first sustain signal SUS1 will be described in more detail with reference to FIG. 5 below.

As shown in FIG. 5, the first sustain signal SUS1 supplied to the scan electrode Y and the sustain electrode Z is alternately supplied and may be periodically repeated.

More specifically, during the sustain period SP of the subfield, the first sustain signal SUS1 supplied to the scan electrode Y and the first sustain signal SUS1 supplied to the sustain electrode Z may have a half cycle phase difference. have.

Therefore, the voltage of the first sustain signal SUS1 supplied to the scan electrode Y gradually rises from the negative sustain voltage (-VS) to the positive sustain voltage VS, thereby increasing the positive sustain voltage VS. During the maintenance, the voltage of the first sustain signal SUS1 supplied to the sustain electrode Z may maintain the ground level voltage GND.

In addition, while the voltage of the first sustain signal SUS1 supplied to the scan electrode Y maintains the ground level voltage GND, the voltage of the first sustain signal SUS1 supplied to the sustain electrode Z is negative. It can gradually rise from the polar sustain voltage (-VS) to the positive sustain voltage (VS).

Thus, the period of the 1st sustain signal SUS1 supplied to the scan electrode Y and the 1st sustain signal SUS1 supplied to the sustain electrode Z has a phase difference of half cycle, and therefore the scan electrode Y and the sustain are made. The voltage difference between the electrodes Z can be alternately made to be the positive sustain voltage VS and the negative sustain voltage (-VS).

In addition, in the first sustain signal SUS1, the magnitude of the rising slope gradually rising from the negative sustain voltage (-VS) to the positive sustain voltage VS is equal to the voltage at the ground level at the positive sustain voltage VS. It may be smaller than the falling slope of the signal falling to GND) or the falling slope of the signal falling from the ground level voltage GND to the negative sustain voltage -VS. By doing in this way, there exists an effect which can mitigate the electric shock which a switching element can receive by a big voltage fluctuation.

In addition, the magnitude of the rising slope (FIGS. 8 and SLa) gradually rising from the negative sustain voltage (-VS) to the positive sustain voltage VS in the first sustain signal SUS1 will be described later with reference to FIGS. In the second sustain signal SUS2, it is smaller than the magnitude of the falling slope (FIG. 8, SLb) gradually descending from the voltage 2VS of the positive sustain voltage VS to the voltage GND of the ground level. That is, the resonance period D4 of the first sustain signal SUS1 is relatively longer than the resonance period D4 'of the second sustain signal SUS2. In this manner, the supply efficiency of the energy supplied to the plasma display panel 100 by resonance and the recovery efficiency of the energy recovered from the plasma display panel 100 can be maintained better.

Further, in the first sustain signal SUS1, for example, the period D2 for maintaining the ground level GND at the scan electrode Y may be longer than the period D3 for maintaining the positive sustain voltage VS. have.

Further, in the first sustain signal SUS1, the period D2 of maintaining the ground level GND gradually rises from the negative sustain voltage (-VS) to the positive sustain voltage VS, and the positive sustain voltage It may be the same as the period D1 for holding VS. In this way, the voltage is changed at the other electrode (for example, the sustain electrode Z) while one electrode (for example, the scan electrode Y) is fixed at the ground level GND. It is possible to more easily control the voltage fluctuation between (Y) and the sustain electrode (Z).

In addition, as illustrated, a time point t1 at which the first sustain signal SUS1 supplied to the scan electrode Y falls from the ground level voltage GND to the negative sustain voltage −VS without LC resonance and The point in time t1 at which the first sustain signal SUS1 supplied to the sustain electrode Z falls from the positive sustain voltage VS to the ground level voltage GND without LC resonance may coincide. In this manner, the voltage difference YZ between the first sustain signal SUS1 supplied to the scan electrode Y and the first sustain signal SUS1 supplied to the sustain electrode Z is equal to the negative sustain voltage (-VS). It can keep the size.

In addition, as shown in the drawing, a time point t2 at which the first sustain signal SUS1 supplied to the sustain electrode Z descends from the ground level voltage GND to the negative sustain voltage −VS without LC resonance and The point in time t2 at which the first sustain signal SUS1 supplied to the scan electrode Y falls from the positive sustain voltage VS to the ground level voltage GND without LC resonance may coincide. In this way, the voltage difference YZ between the first sustain signal SUS1 supplied to the scan electrode Y and the first sustain signal SUS1 supplied to the sustain electrode Z is equal to the positive sustain voltage VS. It can keep the size.

FIG. 6 is a diagram for describing an example in which the second sustain signal SUS2 is supplied during the sustain period SP in FIG. 4.

Here, since the reset period RP and the address period AP are the same as those described with reference to FIG. 4, the description will be omitted only for the sustain period SP.

As illustrated in FIG. 6, the driver 110 may supply the second sustain signal SUS2 to the scan electrode Y and the sustain electrode Z.

As shown in the drawing, the second sustain signal SUS2 rises from the ground level voltage GND to the positive sustain voltage VS, maintains the positive sustain voltage VS, and maintains the positive sustain voltage The voltage rises from VS to twice the voltage (2VS) of the positive sustain voltage VS, and gradually decreases from the positive sustain voltage VS to the ground level voltage GND, thereby lowering the ground level voltage GND. Keep it.

The second sustain signal SUS2 will be described in more detail with reference to FIG. 7.

As illustrated in FIG. 7, the second sustain signal SUS2 supplied to the scan electrode Y and the sustain electrode Z is alternately supplied and may be periodically repeated.

More specifically, the second sustain signal SUS2 supplied to the scan electrode Y and the second sustain signal SUS2 supplied to the sustain electrode Z during the sustain period SP of the subfield have a phase difference of 1/2 cycle. It can have

Therefore, during the period D2 'during which the voltage of the second sustain signal SUS2 supplied to the scan electrode Y maintains the positive sustain voltage VS, the second sustain signal supplied to the sustain electrode Z ( SUS2 may be lowered from the voltage twice the voltage of the positive sustain voltage VS to the ground level voltage GND, and maintain the ground level voltage GND.

In addition, the voltage of the second sustain signal SUS2 supplied to the scan electrode Y is lowered from the voltage 2VS of the positive sustain voltage VS to the voltage GND of the ground level, and thus the voltage of the ground level. During the period of maintaining GND, the voltage of the second sustain signal SUS2 supplied to the sustain electrode Z can maintain the positive sustain voltage VS.

As such, the period of the second sustain signal SUS2 supplied to the scan electrode Y and the second sustain signal SUS2 supplied to the sustain electrode Z has a phase difference of 1/2 cycle, whereby the scan electrode Y And the voltage difference between the sustain electrode Z and the positive sustain voltage (VS) and the negative sustain voltage (-VS) alternately.

In addition, as shown in the drawing, the second sustain signal SUS2 supplied to the scan electrode Y rises without LC resonance from the ground level voltage GND to the positive polarity sustain voltage VS without sustaining t3 and sustain. The time t3 at which the second sustain signal SUS2 supplied to the electrode Z rises without LC resonance from the positive sustain voltage VS to the double voltage voltage 2VS of the positive sustain voltage VS is the same. Can be. In this manner, the voltage difference YZ between the second sustain signal SUS2 supplied to the scan electrode Y and the second sustain signal SUS2 supplied to the sustain electrode Z is equal to the negative sustain voltage (-VS). It can keep the size.

In addition, as shown in the drawing, a time t4 at which the second sustain signal SUS2 supplied to the sustain electrode Z rises from the ground level voltage GND to the positive sustain voltage VS without LC resonance and scanning is performed. The time t4 at which the second sustain signal SUS2 supplied to the electrode Y rises without LC resonance from the positive sustain voltage VS to the double voltage voltage 2VS of the positive sustain voltage VS is the same. Can be. In this way, the voltage difference YZ between the first sustain signal SUS1 supplied to the scan electrode Y and the first sustain signal SUS1 supplied to the sustain electrode Z is equal to the positive sustain voltage VS. It can keep the size.

In addition, in the second sustain signal SUS2, the magnitude of the falling slope gradually falling from the voltage double of the positive sustain voltage VS to the ground level voltage GND is the ground level voltage GND. It may be less than the magnitude of the rising slope rising from the positive sustain voltage (VS) or the rising slope rising from the positive sustain voltage (VS) to twice the voltage (2VS) of the positive sustain voltage (VS). By doing in this way, there exists an effect which can mitigate the electric shock which a switching element can receive by a big voltage fluctuation.

In addition, the magnitude of the falling slope (FIG. 8, SLb) gradually falling from the voltage twice the voltage of the positive sustain voltage VS to the ground level voltage GND in the second sustain signal SUS2 is the first magnitude. In the sustain signal SUS1, the magnitude of the rising slope (FIG. 8, SLa) gradually rising from the negative sustain voltage (-VS) to the positive sustain voltage VS is greater. That is, the resonance period D4 ′ of the second sustain signal SUS2 is relatively shorter than the resonance period D4 of the first sustain signal SUS1. This is illustrated in more detail in FIG. 8.

In this way, the sustain discharge by the second sustain signal SUS2 can be made relatively stronger than the sustain discharge by the first sustain signal SUS1.

Therefore, there is an effect of reducing the moving spots that may occur in the image of the plasma display panel 100, that is, the spots that appear as if the wave is moving in the image.

Moreover, such moving spots tend to occur stronger as the brightness of the image is brighter. Therefore, when the luminance of the image is bright, it is more effective to supply the second sustain signal SUS2 to the plasma display panel 100.

Further, in the second sustain signal SUS2 supplied to the scan electrode Y, the period D2 'for maintaining the positive sustain voltage VS is the period D3' for maintaining the ground level voltage GND. It can be longer.

Further, in the second sustain signal SUS2, the period D2 'during which the positive sustain voltage VS is maintained extends from twice the voltage 2VS of the positive sustain voltage VS to the ground level voltage GND. It may be equal to the period D1 ′ that gradually decreases and maintains the ground level voltage GND. Thus, by changing the voltage at the other electrode (for example, the sustain electrode Z) while one electrode (for example, the scan electrode Y) is fixed at the ground level, the scan electrode Y It is possible to more easily control the voltage fluctuation between the sustain electrode and the sustain electrode (Z).

FIG. 8 is a diagram for describing an example in which the first sustain signal SUS1 and the second sustain signal SUS2 are supplied together during the sustain period SP in FIG. 4.

As shown in FIG. 8, the first sustain signal SUS1 and the second sustain signal SUS2 may be supplied together during the sustain period SP of the subfield.

As shown in more detail, the first sustain signal SUS1 may be supplied first, and then the second sustain signal SUS2 may be supplied. Although not shown, the second sustain signal SUS2 is supplied, but the first sustain signal SUS2 is supplied. The signal SUS1 may be supplied, and the first sustain signal SUS1 and the second sustain signal SUS2 may be alternately repeated. Here, when the first sustain signal SUS1 and the second sustain signal SUS2 are alternately repeated, the resonance period is different from each other, thereby removing the afterimage of the image.

The first sustain signal SUS1 and the second sustain signal SUS2 are more specifically compared as follows.

In the period D4 in which the first sustain signal SUS1 gradually rises from the negative sustain voltage (-VS) to the positive sustain voltage VS, the second sustain signal SUS2 is set to the positive sustain voltage VS. It can be made longer than the period (D4 ') which gradually falls from the double voltage (2VS) to the ground level voltage (GND). In other words, the magnitude of the rising slope SLa in which the first sustain signal SUS1 gradually rises from the negative sustain voltage (-VS) to the positive sustain voltage VS is smaller than that of the second sustain signal SUS2. It can be made larger than the magnitude of the falling slope SLb falling from the voltage 2VS twice the sustain voltage VS to the voltage GND of the ground level. In this way, when the first sustain signal SUS1 is supplied to the plasma display panel 100 as described above with reference to FIG. 6, sufficient energy for sustain discharge is supplied and sufficient energy is supplied from the plasma display panel 100. The driving efficiency can be improved and driving efficiency can be improved. When the second sustain signal SUS2 is supplied to the plasma display panel 100 as described above with reference to FIG. 7, it may occur in the image of the plasma display panel 100. There is an effect that can reduce the moving stains more effectively.

.

In addition, as illustrated, the period of the first sustain signal SUS1 may be longer than the period of the second sustain signal SUS2.

9 is a view for explaining an example in which the first sustain signal SUS1 and the second sustain signal SUS2 are supplied differently for each subfield.

As illustrated in FIG. 9, the first sustain signal SUS1 may be supplied in a subfield having a low gray scale weight, and the second sustain signal SUS2 may be supplied in a subfield with a high gray scale weight.

More specifically, the first sustain signal SUS1 may be supplied during the sustain period SP from the first subfield SF1 to the fourth subfield SF4, and the second sustain signal SUS2 may be applied to the fifth sustain signal SUS2. It can be supplied during the sustain period SP from the subfield SF5 to the eighth subfield SF8.

In this way, the driving efficiency of the plasma display panel 100 may be further improved in the subfield representing the low grayscale image, and the subfield representing the high grayscale image may occur in the image of the plasma display panel 100. There is an effect that can reduce the moving stains more effectively.

Meanwhile, in FIG. 9, the first sustain signal SUS1 is from the first subfield SF1 to the fourth subfield SF4, and the second sustain signal SUS2 is from the fourth subfield SF4 to the eighth subfield. Although supplying up to SF8 has been described as an example, the first sustain signal SUS1 is supplied only to the first subfield SF1 and the second subfield SF2, and the second sustain signal SUS2 is supplied to the remaining subfields. Can be supplied.

As such, supplying the first sustain signal SUS1 and the second sustain signal SUS2 differently for each subfield may be variously changed.

FIG. 10 illustrates an example in which the first sustain signal SUS1 and the second sustain signal SUS2 are supplied differently for each frame.

As shown in FIG. 10A, in the case of the first frame (Frame 1) in which an image is displayed only in a region A where the number of discharge cells turned on is relatively small, that is, when the average power level APL is low, In the case of the second frame (Frame 2) in which one sustain signal SUS1 is supplied and an image is displayed only in a region B, where the number of discharge cells turned on is relatively large as shown in (b), that is, the average power level. When the APL is high, the second sustain signal SUS2 may be supplied to the scan electrode Y and the sustain electrode Z of the plasma display panel 100.

In FIG. 10, it is assumed that the luminance of an image displayed in each discharge cell is the same.

This is because when the number of discharge cells turned on is relatively small, as shown in (a), the load of the plasma display panel 100 is relatively small, so that the movement of moving images on the image of the plasma display panel 100 is relatively small. Will occur. Therefore, in such a case, it is because it is more effective to supply the first sustain signal SUS1 which can improve the driving efficiency rather than the second sustain signal SUS2 which can reduce the moving unevenness, and (b) and In the case where the number of discharge cells that are turned on is relatively large, the load of the plasma display panel 100 is relatively large, so that a strong sustain discharge is effective and a moving stain is likely to occur. Therefore, it is because it is more effective to supply the second sustain signal SUS2 which reduces moving unevenness and causes a relatively stronger sustain discharge.

Meanwhile, in FIG. 10, the case where the first frame Frame 1 and the second frame 2 are not continuous with each other is described as an example. However, the first frame Frame 1 and the second frame Frame 2 are different from each other. The order of the second frame Frame 2 may be a frame that is temporally earlier than the order of the first frame Frame 1.

Although not shown, when the number of discharge cells turned on in the image of the plasma display panel 100 is the same, but the luminance of the image is different, that is, the luminance of the image is low, the average power level APL is low. The first sustain signal SUS1 is supplied in the first frame (Frame 1), and the second sustain signal SUS2 is supplied in the second frame (Frame 2) in which the brightness of the image is high and the average power level APL is high. It can be.

When the luminance is low, the first sustain signal SUS1 may be supplied to improve driving efficiency, rather than the second sustain signal SUS2, which is relatively unlikely to cause moving spots in the image of the plasma display panel 100. When the brightness is high, since moving spots are relatively high in the image of the plasma display panel 100, it is more preferable to supply the second sustain signal SUS2 which may cause sufficient sustain discharge. Because it becomes effective.

FIG. 11 is a diagram for describing an example of an energy recovery circuit included in the driver 110 illustrated in FIG. 1. 12 is an example of a conventional energy recovery circuit for comparison with the present invention.

The energy recovery circuit illustrated in FIG. 11 may supply the first sustain signal SUS1 and the second sustain signal SUS2 described with reference to FIGS. 4 to 10.

As shown, the driving unit 110 may include first to fourth switches S1 to S4, first to fourth inductors L1 to L4, and first to fourth diodes D1 to D4.

 Here, the first switch S1 to the fourth switch S4 may use various switching elements such as a field effect transistor (FET) or a metal oxide semiconductor field effect transistor (MOSFET).

The first switch S1 is disposed between the sustain voltage source VS supplying the positive sustain voltage VS and the scan electrode Y, and supplies the positive sustain voltage VS to the scan electrode Y. The second switch S2 is disposed between the positive sustain voltage source VS and the sustain electrode Z, and serves to supply the positive sustain voltage VS to the sustain electrode Z.

The third switch S3 is disposed between the first node N1 between the first switch S1 and the scan electrode Y and the ground for supplying the ground level voltage GND to the scan electrode Y. The fourth switch S4 is disposed between the second node N2 and the ground GND between the second switch S2 and the sustain electrode Z, and serves to supply a ground level voltage GND. The function serves to supply the ground level voltage GND to the sustain electrode Z.

The first inductor L1 is disposed in parallel with the first switch S1 between the first node N1 and the sustain voltage source VS, and the voltage of the second sustain signal SUS2 supplied to the scan electrode Y. Resonance occurs to gradually fall from the voltage twice the voltage of the positive sustain voltage VS to the ground level voltage GND, and the second inductor L2 is connected to the second node N2 and the sustain. The voltage of the second sustain signal SUS2 disposed in parallel with the second switch S2 between the voltage sources VS and supplied to the sustain electrode Z is twice the voltage of the positive sustain voltage VS (2VS). To cause the resonance to gradually fall from the ground level voltage (GND).

Here, the first inductor L1 and the second inductor L2 may have the same inductance. By doing in this way, the period in which resonance occurs by the 1st inductor L1 and the 2nd inductor L2 can be made the same. That is, in the second sustain signal SUS2 supplied to each of the scan electrode Y and the sustain electrode Z, the voltage GND of the ground level from the double voltage (2VS) of the positive sustain voltage VS due to resonance is caused. The slopes of descent gradually descending to) can be equal to each other.

The third inductor L3 is disposed in parallel with the third switch S3 between the first node N1 and the ground GND, so that the third sustain signal SUS1 is supplied to the scan electrode Y. Resonance occurs such that the voltage gradually rises from the negative sustain voltage (-VS) to the positive sustain voltage (VS), and the fourth inductor L4 is connected between the second node N2 and the ground GND. The voltage of the first sustain signal SUS1, which is disposed in parallel with the fourth switch S4 and supplied to the sustain electrode Z, gradually increases from the negative sustain voltage (-VS) to the positive sustain voltage VS. Let resonance occur.

Here, the third inductor L3 and the fourth inductor L4 may have the same inductance. By doing in this way, the period in which resonance occurs by the 3rd inductor L3 and the 4th inductor L4 can be made the same. That is, in the first sustain signal SUS1 supplied to each of the scan electrode Y and the sustain electrode Z, the resonance gradually rises from the negative sustain voltage (-VS) to the positive sustain voltage VS by resonance. The ascending slope can be equal to each other.

In addition, the inductance of the first inductor L1 and the second inductor L2 may be smaller than that of the third inductor L3 and the fourth inductor L4. In this way, the period in which resonance occurs by the first inductor L1 and the second inductor L2 can be shorter than the period in which resonance occurs in the third inductor L3 and the fourth inductor L4. . That is, the magnitude of the falling slope gradually falling from the second sustain signal SUS2 to twice the voltage of the positive sustain voltage VS to the ground level voltage GND is negative in the first sustain signal SUS1. It can be made larger than the magnitude of the rising slope gradually increasing from the polar sustain voltage (-VS) to the positive sustain voltage (VS).

In addition, the resonance using the first inductor L1 and the second inductor L2 may occur when the number of discharge cells turned on in the plasma display panel 100 is large. ) And the fourth inductor L4 may be generated when the number of discharge cells turned on in the plasma display panel 100 is small. This is the same as the reason described with reference to FIG. 10 and will be omitted.

In addition, a period in which resonance occurs by the first inductor L1 and the second inductor L2 may be shorter than a period in which resonance occurs in the third inductor L3 and the fourth inductor L4. This is because the sizes of the first and second inductors L1 and L2 are smaller than those of the third and fourth inductors L4.

In addition, the energy recovery circuit according to the present invention may further include the first to fourth diode (D1 ~ D4) for preventing the reverse current.

More specifically, the first diode D1 is disposed in parallel with the first switch S1 between the sustain voltage source VS and the first node N1 to pass through the first inductor L1 from the sustain voltage source VS. The current flowing to the first node N1 is cut off, and the second diode D2 is disposed in parallel with the second switch S2 between the sustain voltage source VS and the second node N2 to maintain the sustain voltage source VS. The current flowing from the second node N2 to the second inductor L2 may be blocked.

In FIG. 11, the first diode D1 is disposed between the first inductor L1 and the first node N1 as an example. Alternatively, the first diode D1 is disposed between the sustain voltage source VS and the first inductor L1. May be In FIG. 5, the second diode D2 is also disposed between the second inductor L2 and the second node N2 as an example. Alternatively, the second diode D2 is disposed between the sustain voltage source VS and the second inductor L2. It can be.

In addition, the third diode D3 is disposed in parallel with the third switch S3 between the first node N1 and the ground to flow through the third inductor L3 from the first node N1 to the ground. And the fourth diode D4 is disposed between the second node N2 and the ground, and the fourth switch S4 is a current flowing from the second node N2 to the ground through the fourth inductor L4. Can be blocked. In FIG. 11, for example, the third diode D3 is disposed between the third inductor L3 and the ground. Alternatively, the third diode D3 may be disposed between the first node N1 and the third inductor L3. Although the fourth diode D4 is also disposed between the fourth inductor L4 and the ground, the fourth diode D4 may be disposed between the fourth inductor L4 and the second node N2.

This energy recovery circuit according to the present invention is compared with the conventional energy recovery circuit as shown in FIG. 12 as follows.

In the conventional energy recovery circuit as shown in FIG. 12, the rising slope of the signal in which the voltage gradually rises due to resonance in the sustain signal supplied to the scan electrode Y during the sustain period SP of the subfield is 2; In addition to the existing ER_UP2 and ER_DN switching elements, a separate control signal line for controlling one ER_UP1 switching element and ER_UP1 switching element must be added. In this case, there is a problem that the manufacturing cost is increased due to the addition of the switching element.

However, in the case of the energy recovery circuit according to the present invention as shown in FIG. The rising slope or the falling slope of the sustain signal supplied to the scan electrode Y or the sustain electrode Z may be varied during the sustain period SP of the subfield.

In the conventional energy recovery circuit as shown in FIG. 12, the switching elements SUS_UP and SUS_DN for maintaining the sustain voltage or the ground voltage in the sustain signal on the scan electrode Y side and the sustain electrode Z side, and Although there is a problem in that the manufacturing cost increases due to separate switching elements ER_UP1, ER_UP2, and ER_DN for controlling resonance, in the case of the energy recovery circuit according to the present invention as shown in FIG. 11, one switching element is a sustain voltage or a ground voltage. By controlling to maintain the control while maintaining the resonance has the effect of further reducing the manufacturing cost.

In addition, in the case of the present invention, by connecting the ground (GND) to the frame, there is an effect that can reduce the external noise by the plasma display panel 100 (Cp) during resonance.

In addition, in the energy recovery circuit of the present invention as shown in FIG. 11, the resonance current flows through the frame that is hardly affected by the noise of the plasma display panel 100 (Cp), and thus the inductance tolerance range during inductance matching is shown. (inductance tolerance) has the effect of reducing.

Therefore, the plasma display device according to the present invention has an effect of improving driving reliability.

FIG. 13 is a diagram for explaining an example of a switching timing diagram for driving the energy recovery circuit shown in FIG. 11, and FIGS. 14 to 17 are diagrams showing the operation of the energy recovery circuit according to each switching timing.

13 to 17 illustrate an example in which the first sustain signal SUS1 is supplied to the scan electrode Y and the sustain electrode Z as an example.

First, the first sustain signal SUS1 supplied by the energy recovery circuit according to an example of the present invention will be described as follows.

As shown in FIG. 13, the first sustain signal SUS1 supplied to the scan electrode Y is operated from the ground level voltage GND to the negative sustain voltage during the first period P1 of the sustain period SP. After falling down to (-VS) without LC resonance, the second period gradually rises by LC resonance from the negative sustain voltage (-VS) to the positive sustain voltage (VS), and continues with the first period P1. During (P2), the positive sustain voltage (VS) is maintained and the LC is maintained from the positive sustain voltage (VS) to the ground level voltage (GND) during the third period (P3) subsequent to the second period (P2). Maintaining the ground level voltage GND after falling without resonance, and maintaining the ground level voltage GND for the fourth period P4 subsequent to the third period P3.

In addition, the first sustain signal SUS1 supplied to the sustain electrode Z is LC from the ground level voltage GND to the negative sustain voltage (-VS) during the third period P3 of the sustain period SP. After falling without resonance, the voltage gradually rises by LC resonance from the negative sustain voltage (-VS) to the positive sustain voltage (VS), and maintains the positive sustain voltage (VS) for the fourth period (P4). In the first period P1 consecutive to the fourth period P4, the voltage is maintained from the positive sustain voltage VS to the ground level voltage GND without falling through LC resonance, and the second period P2 is maintained. ), Maintaining the ground level voltage GND.

Next, an operation of the energy recovery circuit for implementing the first sustain signal SUS1 described above will be described.

First, as shown in FIG. 13, when the fourth switch S4 is turned on during the first period P1 of the sustain period SP of the subfield, as shown in FIG. 14, Z is shown. A current path is formed, such as N2 → S4 → GND → D3 → L3 → N1 → Y.

When such a current path is formed, as illustrated in FIG. 13, at the instant t1 when the fourth switch S4 is turned on, the voltage of the scan electrode Y is the ground level voltage GND. ) To the negative sustain voltage (-VS) drops without LC resonance, and the voltage of the sustain electrode (Z) falls from the positive sustain voltage (VS) to the ground level voltage (GND) without LC resonance, immediately after From the negative sustain voltage (-VS) to the positive sustain voltage VS, the voltage gradually rising by the resonance with the third inductor L3 is supplied to the scan electrode Y during the remaining first period P1. The sustain electrode Z is supplied with the ground level voltage GND.

More specifically, the inductor can not instantaneously change the current through the inductor, but the voltage difference across the inductor can change instantaneously, and the capacitor has a voltage across the capacitor even if the voltage across the capacitor instantaneously changes The difference cannot change instantaneously.

Accordingly, the voltage difference across the third inductor L3 may change momentarily, and the voltage of the scan electrode Y connected to the first node N1 and the sustain electrode Z connected to the second node N2 may change. Each of the voltages is in a state capable of instantaneous change.

Accordingly, the second node N2 is connected to the ground by the turn on of the fourth switch S4, and instantaneously becomes the ground level voltage GND, and the voltage of the sustain electrode Z is also positive. At the polarity sustain voltage VS, the voltage becomes the ground level voltage GND. At this time, the instantaneous voltage drop of the sustain electrode Z becomes a voltage drop irrelevant to the LC resonance.

At this time, since the plasma display panel 100 (Cp) including the scan electrode Y and the sustain electrode Z is the same as the equivalent capacitor, the voltage difference YZ across the plasma display panel 100 (Cp) It cannot change instantly.

Therefore, as shown in FIG. 12, the voltage difference YZ across the plasma display panel 100 (Cp) is the moment immediately before the fourth switch S4 is turned on (t1- in FIG. 12). ), The magnitude of the negative sustain voltage (-VS), which is the voltage difference (YZ) across the plasma display panel 100 (Cp) immediately before the fourth switch S4 is turned on. It must be maintained.

Accordingly, in order to maintain the voltage difference YZ across the plasma display panel 100 (Cp) as the voltage of the sustain electrode Z decreases instantaneously, the voltage of the scan electrode Y is also independent of the LC resonance. It is instantaneously lowered from the ground level voltage (GND) to the negative sustain voltage (-VS). Therefore, the voltage difference across the third inductor L3 also changes instantaneously from the sustain voltage VS to the ground voltage GND.

In this manner, immediately after the voltages of the scan electrode Y and the sustain electrode Z are simultaneously dropped simultaneously without LC resonance, the third inductor L3 and the plasma display panel 100 (Cp) start LC resonance. .

At this time, since the sustain electrode Z is connected to the ground GND, the ground level voltage GND is continuously supplied, and the scan electrode Y is positive from the negative sustain voltage (-VS) by LC resonance. The voltage gradually rising up to the polarity sustain voltage VS is supplied.

Secondly, as shown in FIG. 13, in a state in which the fourth switch S4 maintains Turn On during the second period P2 consecutive to the first period P1, the first period P1 is the first. When the switch S1 is turned on, as shown in FIG. 15, a current path such as VS → S1 → N1 → Cp → N2 → S4 → GND is formed.

According to this current path, as shown in FIG. 13, the scan electrode Y is connected to the positive sustain voltage source VS to maintain the positive sustain voltage VS, and the sustain electrode Z is grounded. Since it maintains the connection with GND, it maintains the ground level voltage GND.

Thereafter, the first to fourth switches S4 and S1 to S4 are all turned on during the period between the second period P2 and the third period P3, so that the energy recovery circuit is floating. ) State.

By providing a period in which the energy recovery circuit is in a floating state, the third switch S3 is turned on after a predetermined period after the first switch S1 and the fourth switch S4 are turned off. ) To ensure the stability of the driving.

Third, as shown in FIG. 13, when the third switch S3 is turned on during the third period P3 after the second period P2, as shown in FIG. 16. A current path is formed such that Y → N1 → S3 → GND → D4 → L4 → N2 → Z.

When such a current path is formed, due to the voltage change characteristics of the inductor and capacitor described in the first period P1, as shown in FIG. 13, the scan electrode at the moment t3 is turned on (t2). The voltage of (Y) falls without resonance from the positive sustain voltage VS to the ground level voltage GND, and the voltage of the sustain electrode Z is reduced from the ground level voltage GND to the negative sustain voltage (-VS). ) Is lowered without resonance, and immediately after the fall, the ground electrode voltage GND is supplied to the scan electrode Y and the negative sustain voltage (-VS) for the remaining third period P3. ) Is gradually supplied by the resonance with the third inductor L3 from the positive polarity sustain voltage VS.

Here, the voltage of the scan electrode Y and the sustain electrode Z at the instant (t2) when the voltage of the scan electrode Y and the sustain electrode Z decreases by turning on the third switch S3. The difference YZ is equal to the magnitude of the positive sustain voltage VS.

Subsequently, lastly, as shown in FIG. 13, in a state in which the third switch S3 maintains Turn On during the fourth period P4 subsequent to the third period P3. When the second switch S2 is turned on, a current path such as VS → S2 → N2 → Cp → N1 → S3 → GND is formed as shown in FIG. 17.

According to this current path, as shown in FIG. 13, the scan electrode Y maintains the ground level voltage GND, and the sustain electrode Z maintains the positive sustain voltage VS. .

Thereafter, the first to fourth switches S4 and S1 to S4 are all turned on during the period between the fourth period P4 and the first period P1, so that the energy recovery circuit is floated. Floating) state.

By providing a period in which the energy recovery circuit is in a floating state, the fourth switch S4 is turned on after a predetermined period after the second switch S2 and the third switch S3 are turned off. To ensure the stability of the drive.

FIG. 18 is a diagram for explaining an example of a switching timing diagram for driving the energy recovery circuit shown in FIG. 11, and FIGS. 19 to 22 are diagrams showing the operation of the energy recovery circuit according to each switching timing.

18 to 22 show an example in which the second sustain signal SUS2 is supplied to the scan electrode Y and the sustain electrode Z. As shown in FIG.

First, the second sustain signal SUS2 supplied by the energy recovery circuit according to an example of the present invention will be described.

As shown in FIG. 18, the second sustain signal SUS2 supplied to the scan electrode Y is the positive sustain voltage from the ground level voltage GND during the fifth period P5 of the sustain period SP. After rising to (VS) without LC resonance, the positive sustain voltage (VS) is maintained, and the positive sustain voltage (VS) is maintained for the sixth period (P6) continuous with the fifth period (P5). During the seventh period P7 after the sixth period P6, the positive sustain voltage VS rises without resonance from the positive sustain voltage VS to twice the voltage 2VS of the positive sustain voltage VS without resonance, and then the positive sustain voltage VS The voltage at ground level GND is gradually lowered from the double voltage (2VS) to ground level voltage GND by LC resonance and during the eighth period P8 subsequent to the seventh period P7. Maintaining.

In addition, the second sustain signal SUS2 supplied to the sustain electrode Z (Y) is the positive sustain voltage VS from the ground level voltage GND during the seventh period P7 of the sustain period SP. After rising without LC resonance, the positive sustain voltage (VS) is maintained, and the positive sustain voltage (VS) is maintained for the eighth period (P8) subsequent to the seventh period (P7), and the eighth period ( During the fifth period P5 after P8), the resonance sustain voltage rises from the positive sustain voltage VS to twice the voltage 2VS of the positive sustain voltage VS without resonance, and then doubles the positive sustain voltage VS. From the voltage 2VS to the ground level voltage GND, the voltage is gradually lowered by LC resonance, and the ground level voltage GND is maintained during the sixth period P6 continuous with the fifth period P5. Steps.

As described above, the second sustain signal SUS2 supplied to the scan electrode Y and the second sustain signal SUS2 supplied to the sustain electrode Z have a half cycle phase difference.

Next, an operation of the energy recovery circuit for implementing the aforementioned second sustain signal SUS2 will be described.

Here, it is assumed that the voltage of the scan electrode Y is set to the ground voltage GND, and the voltage of the sustain electrode Z is set to the positive sustain voltage VS.

First, as shown in FIG. 18, when the first switch S1 is turned on during the fifth period P5 of the sustain period SP of the subfield, as shown in FIG. 19, Z is shown. A current path is formed such that → N2 → D2 → L2 → VS → S1 → N1 → Y.

When such a current path is formed, as illustrated in FIG. 18, at the instant t3 when the first switch S1 is turned on, the voltage of the scan electrode Y becomes the ground level voltage GND. From the positive sustain voltage (VS) without LC resonance, and the voltage of the sustain electrode (Z) increases without the LC resonance from the positive sustain voltage (VS) to twice the voltage (2VS) of the positive sustain voltage (VS). Immediately after the rise, the scan electrode Y maintains the positive sustain voltage VS for the remaining fifth period P5, and the sustain electrode Z is twice the voltage of the positive sustain voltage VS. From 2VS to the ground level voltage GND, a voltage that gradually decreases due to resonance with the second inductor L2 is supplied.

More specifically, the voltage of the first node N1 is instantaneously increased without LC resonance from the ground level voltage GND to the positive sustain voltage VS at the time t3 when the first switch S1 is turned on. Accordingly, the voltage of the scan electrode Y also rises instantaneously without LC resonance from the ground level voltage GND to the positive sustain voltage VS.

In addition, since the voltage difference across the CP should be continuous due to the characteristics of the capacitor, in order to maintain the voltage difference across the CP immediately before the turn-on of the first switch S1, the voltage of the sustain electrode Z is also instantaneously positive and without LC resonance. At VS, the voltage rises to twice the voltage (2VS) of the positive sustain voltage VS. As a result, the voltage difference across the second inductor L2 also increases from 0V to VS.

As such, after the voltages of the scan electrode Y and the sustain electrode Z rise momentarily, the second inductor L2 and the plasma display panel 100 (CP) start resonance for the remaining fifth period P5. Therefore, the voltage of the sustain electrodes Z and Y gradually decreases from the voltage twice the voltage of the positive sustain voltage VS to the ground level voltage GND. In addition, since the voltage of the scan electrode Y is connected to the positive sustain voltage source VS, the positive sustain voltage VS is maintained.

Here, the voltage difference (YZ) between the scan electrode (Y) and the sustain electrode (Z) at the moment when the voltage of the scan electrode (Y) and the sustain electrode (Z) increases due to the turn-on of the first switch (S1). ) Is equal to the magnitude of the negative sustain voltage (-VS) due to the voltage characteristics of the capacitor.

Secondly, as shown in FIG. 18, in a state in which the first switch S1 maintains Turn On during the sixth period P6 consecutive to the fifth period P5, the fourth period P4 is applied. When the switch S4 is turned on, as shown in FIG. 20, a current path such as VS → S1 → N1 → Cp → N2 → S4 → GND is formed.

According to this current path, as shown in FIG. 18, the scan electrode Y conducting with the positive sustain voltage source VS maintains the positive sustain voltage VS, and the sustain conducting with ground GND. The electrode Z continuously maintains the ground level voltage GND.

Thereafter, the first to fourth switches S4 and S1 to S4 are all turned on during the period between the sixth period P6 and the seventh period P7, so that the energy recovery circuit is floated. Floating) state.

By providing a period in which the energy recovery circuit is in a floating state, the second switch S2 is turned on after a predetermined period after the first switch S1 and the fourth switch S4 are turned off. ) To ensure the stability of the driving.

Third, as shown in FIG. 18, when the second switch S2 is turned on during the seventh period P7 after the sixth period P6, as shown in FIG. 21. A current path is formed such that Y → N1 → D1 → L1 → VS → S2 → N2 → Z.

When such a current path is formed, as shown in FIG. 18, the voltage of the scan electrode Y is changed from the positive sustain voltage VS to the positive sustain voltage at the time t4 when the second switch S2 is turned on. The voltage of the sustain electrode Z rises without resonance from the ground level voltage GND to the positive sustain voltage VS without resonance. During the seventh period P7, the voltage of the scan electrode Y gradually decreases from the voltage 2VS of the positive sustain voltage VS to the voltage GND of the ground level, and the sustain electrode Z Since the voltage of V is conductive with the positive sustain voltage source VS, the positive sustain voltage VS is maintained.

Here, the voltage of the scan electrode Y and the sustain electrode Z is instantaneous (t4) when the voltage between the scan electrode Y and the sustain electrode Z increases by turning on the second switch S2. The difference YZ is equal to the magnitude of the positive sustain voltage VS because of the voltage characteristics of the capacitor.

Then, lastly, as shown in FIG. 18, in a state in which the second switch S2 maintains Turn On during the eighth period P8 subsequent to the seventh period P7. When the third switch S3 is turned on, a current path such as VS → S2 → N2 → Cp → N1 → S3 → GND is formed as shown in FIG. 22.

According to this current path, as shown in FIG. 18, the scan electrode Y maintains the ground level voltage GND, and the sustain electrode Z maintains the positive sustain voltage VS. .

Thereafter, the first to fourth switches S4 and S1 to S4 are all turned on during the period between the eighth period P8 and the fifth period P5, so that the energy recovery circuit is floating. ) State.

By providing a period in which the energy recovery circuit is in a floating state, the first switch S1 is turned on after a predetermined period after the second switch S2 and the third switch S3 are turned off. To ensure the stability of the drive.

As described above, the plasma display device according to the present invention reduces the number of switching elements in the energy recovery circuit, thereby reducing the manufacturing cost of the plasma display device, and is connected to the back of the plasma display in the energy recovery circuit to connect the inductor for resonance. By omitting the connection line, a more stable sustain signal is supplied to the plasma display panel 100 (Cp) by minimizing the influence of external noise.

In addition, the plasma display apparatus according to the present invention uses the same energy recovery circuit, but by different driving methods, the first sustain signal SUS1 and the second sustain signal SUS2 having different shapes, as described above, There is an effect that can be supplied to the display panel 100.

In addition, the plasma display apparatus according to the present invention may include a sustain signal supplied to the plasma display panel 100 according to the number of discharge cells turned on in the image of the plasma display panel 100 or the luminance of the first sustain signal SUS1. Or by selecting at least one of the second sustain signals SUS2 so as to be appropriately supplied, thereby improving driving efficiency of the plasma display panel 100, removing moving stains, and removing afterimages. have.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a view for explaining a plasma display device according to the present invention.

2 is a view for explaining an example of the structure of a plasma display panel in the plasma display device shown in FIG.

FIG. 3 is a diagram for explaining an example of an image frame for implementing gradation of an image. FIG.

4 is a view for explaining an example of a driving method of the plasma display device according to FIG. 1;

FIG. 5 is a diagram for explaining the first sustain signal shown in FIG. 4 in more detail.

FIG. 6 is a view for explaining an example in which the second sustain signal SUS2 is supplied during the sustain period SP in FIG. 4.

FIG. 7 is a diagram for explaining the second sustain signal shown in FIG. 6 in more detail.

8 is a view for explaining an example in which the first sustain signal SUS1 and the second sustain signal SUS2 are supplied together during the sustain period SP in FIG. 4.

9 is a view for explaining an example in which the first sustain signal SUS1 and the second sustain signal SUS2 are supplied differently for each subfield.

10 is a view for explaining an example in which the first sustain signal SUS1 and the second sustain signal SUS2 are supplied differently for each frame.

FIG. 11 is a view for explaining an example of an energy recovery circuit included in the driving unit 110 shown in FIG. 1.

12 is an example of a conventional energy recovery circuit for comparison with the present invention.

FIG. 13 is a view for explaining an example of a switching timing diagram for driving the energy recovery circuit shown in FIG.

14 to 17 show the operation of the energy recovery circuit according to each switching timing.

18 is a view for explaining an example of a switching timing diagram for driving the energy recovery circuit shown in FIG.

19 to 22 show the operation of the energy recovery circuit according to each switching timing.

Claims (24)

A plasma display panel including a scan electrode and a sustain electrode; A first switch disposed between the scan electrode and a sustain voltage source for supplying a positive sustain voltage; A second switch disposed between the positive sustain voltage source and the sustain electrode; A third switch disposed between a first node between the first switch and the scan electrode and a ground for supplying a ground level voltage (GND); A fourth switch disposed between the second node and the ground between the second switch and the sustain electrode; A first inductor disposed in parallel with the first switch between the first node and the sustain voltage source; A second inductor disposed in parallel with the second switch between the second node and the sustain voltage source; A third inductor disposed in parallel with the third switch between the first node and the ground; And A fourth inductor disposed in parallel with the fourth switch between the second node and the ground; Plasma display device comprising a. The method of claim 1, The plasma display device A first diode disposed in parallel with the first switch between the sustain voltage source and the first node to block a current flowing from the sustain voltage source to the first node via the first inductor; And A second diode disposed in parallel with the second switch between the sustain voltage source and the second node to block a current flowing from the sustain voltage source to the second node via the second inductor; Plasma display device further comprising. The method of claim 1, The plasma display device A third diode disposed between the first node and the ground in parallel with the third switch to block a current flowing from the first node to the ground via the third inductor; And A fourth diode disposed between the second node and the ground and blocking the current flowing from the second node to the ground via the fourth inductor; Plasma display device further comprising. The method of claim 1, And the first inductor and the second inductor have the same inductance. The method of claim 1, And the third inductor and the fourth inductor have the same inductance. The method of claim 1, The inductance of the first inductor and the second inductor is smaller than the inductance of the third inductor and the fourth inductor. The method of claim 1, And a period in which resonance occurs by the first inductor and the second inductor is shorter than a period in which resonance occurs in the third inductor and the fourth inductor. The method of claim 1, The resonance using the first inductor and the second inductor is generated when the number of discharge cells turned on in the plasma display panel is large. The method of claim 1, Resonance using the third inductor and the fourth inductor is generated when the number of discharge cells turned on in the plasma display panel is small. In the driving method of the plasma display device comprising a scan electrode and a sustain electrode parallel to the scan electrode, Supplying at least one of a first sustain signal and a second sustain signal to the scan electrode and the sustain electrode during the sustain period of the subfield; The first sustain signal gradually rises from a negative sustain voltage to a positive sustain voltage, maintains the positive sustain voltage, falls from the positive sustain voltage to a voltage at ground level, and decreases the voltage at ground level. Holding, and drop from the ground level voltage to the negative sustain voltage, The second sustain signal rises from the ground level voltage to the positive sustain voltage, maintains the positive sustain voltage, and rises from the positive sustain voltage to twice the voltage of the positive sustain voltage. Gradually dropping from the positive sustain voltage to the ground level voltage and maintaining the ground level voltage Method of driving a plasma display device, characterized in that. 11. The method of claim 10, In the first sustain signal, the magnitude of the rising slope gradually increasing from the negative sustain voltage to the positive sustain voltage is the falling slope of the signal falling from the positive sustain voltage to the ground level voltage or the ground level. Less than the magnitude of the falling slope of the signal falling from the voltage to the negative sustain voltage Method of driving a plasma display device, characterized in that. 11. The method of claim 10, In the first sustain signal, the period of maintaining the ground level is longer than the period of maintaining the positive sustain voltage. Method of driving a plasma display device, characterized in that. 11. The method of claim 10, In the first sustain signal, the period of maintaining the ground level is gradually increased from the negative sustain voltage to the positive sustain voltage and is the same as the period of maintaining the positive sustain voltage. Method of driving a plasma display device, characterized in that. 11. The method of claim 10, The voltage supplied to the sustain electrode gradually increases from the negative sustain voltage to the positive sustain voltage and maintains the positive sustain voltage while the voltage of the first sustain signal supplied to the scan electrode is increased. The voltage of the sustain signal is to maintain the ground level voltage Method of driving a plasma display device, characterized in that. 11. The method of claim 10, In the second sustain signal, the magnitude of the falling slope that gradually decreases from twice the voltage of the positive sustain voltage to the voltage of the ground level is a rising slope that rises from the ground level voltage to the positive sustain voltage or the Less than the magnitude of the rising slope rising from the positive sustain voltage to twice the voltage of the positive sustain voltage Method of driving a plasma display device, characterized in that. 11. The method of claim 10, In the second sustain signal, the period for maintaining the positive sustain voltage is longer than the period for maintaining the ground level voltage. Method of driving a plasma display device, characterized in that. 11. The method of claim 10, In the second sustain signal, the period for maintaining the positive sustain voltage is gradually lowered from the voltage twice the positive sustain voltage to the voltage at the ground level, and is the same as the period for maintaining the voltage at the ground level. Method of driving a plasma display device, characterized in that. 11. The method of claim 10, While the voltage of the second sustain signal supplied to the scan electrode maintains the positive sustain voltage, the second sustain signal supplied to the sustain electrode is a voltage of the ground level from twice the voltage of the positive sustain voltage. Dropping down to a voltage and maintaining said ground level voltage Method of driving a plasma display device, characterized in that. 11. The method of claim 10, The voltage supplied to the sustain electrode while the voltage of the second sustain signal supplied to the scan electrode falls from the voltage twice the positive sustain voltage to the voltage of the ground level and maintains the ground level voltage. The voltage of the second sustain signal maintains the positive sustain voltage Method of driving a plasma display device, characterized in that. 11. The method of claim 10, The period in which the first sustain signal gradually rises from the negative sustain voltage to the positive sustain voltage is greater than the period in which the second sustain signal falls from the voltage twice the positive sustain voltage to the voltage at the ground level. Long Method of driving a plasma display device, characterized in that. 11. The method of claim 10, And the period of the first sustain signal is longer than the period of the second sustain signal. In the driving method of the plasma display device comprising a scan electrode and a sustain electrode parallel to the scan electrode, In the same frame, a first sustain signal is supplied to the scan electrode and the sustain electrode in the first subfield having a low gray scale weight, and a second sustain signal is supplied in the second subfield having a gray weight higher than the first subfield. Supply, The first sustain signal gradually rises from a negative sustain voltage to a positive sustain voltage, maintains the positive sustain voltage, falls from the positive sustain voltage to a voltage at ground level, and decreases the voltage at ground level. Holding, and drop from the ground level voltage to the negative sustain voltage, The second sustain signal rises from the ground level voltage to the positive sustain voltage, maintains the positive sustain voltage, and rises from the positive sustain voltage to twice the voltage of the positive sustain voltage. Gradually dropping from the positive sustain voltage to the ground level voltage and maintaining the ground level voltage Method of driving a plasma display device, characterized in that. In the driving method of the plasma display device comprising a scan electrode and a sustain electrode parallel to the scan electrode, Supplying a first sustain signal to the scan electrode and the sustain electrode in a first frame having a low average power level APL, and supplying a second sustain signal when the average power level APL is higher than the first frame, The first sustain signal gradually rises from a negative sustain voltage to a positive sustain voltage, maintains the positive sustain voltage, falls from the positive sustain voltage to a voltage at ground level, and decreases the voltage at ground level. Holding, and drop from the ground level voltage to the negative sustain voltage, The second sustain signal rises from the ground level voltage to the positive sustain voltage, maintains the positive sustain voltage, and rises from the positive sustain voltage to twice the voltage of the positive sustain voltage. Gradually dropping from the positive sustain voltage to the ground level voltage and maintaining the ground level voltage Method of driving a plasma display device, characterized in that. In the driving method of the plasma display device comprising a scan electrode and a sustain electrode parallel to the scan electrode, The first sustain signal is supplied to the scan electrode and the sustain electrode when the number of discharge cells turned on in the subfield having the same gray scale weight is small, and the second sustain signal is supplied when the number of discharge cells turned on is large. , The first sustain signal gradually rises from a negative sustain voltage to a positive sustain voltage, maintains the positive sustain voltage, falls from the positive sustain voltage to a voltage at ground level, and decreases the voltage at ground level. Holding, and drop from the ground level voltage to the negative sustain voltage, The second sustain signal rises from the ground level voltage to the positive sustain voltage, maintains the positive sustain voltage, and rises from the positive sustain voltage to twice the voltage of the positive sustain voltage. Gradually dropping from the positive sustain voltage to the ground level voltage and maintaining the ground level voltage Method of driving a plasma display device, characterized in that.

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