KR100627348B1 - Plasma display device and driving method thereof - Google Patents

Abstract

According to the present invention, after the address operation is performed on one of the scan electrode lines, the sustain discharge operation on the scan electrode line is performed only after the address operation of the last scan electrode line is completed. In order to solve the problem that a considerable time gap occurs until the occurrence of the sustain discharge operation becomes unstable, the cells of the plasma display panel including the plurality of scan electrodes and the plurality of sustain electrodes are divided into a plurality of groups, and the frame In expressing gradation in the subfield method, it is possible to minimize the temporal gap between the address period and the sustain period, so that smooth sustain discharge can occur in the sustain period.

In addition, by applying the first sustain discharge pulse differently from the sustain discharge pulse applied in the sustain period of each group before the common sustain period among the plurality of sustain periods, the address period is first performed to perform a lack of priming particles. It is possible to ensure the stability of the discharge during the common maintenance period in the group in.

PDP, address / hold mixing period, luminance correction period, sustain discharge, common maintenance period

Description

Plasma display device and driving method thereof {PLASMA DISPLAY DEVICE AND DRIVING METHOD THEREOF}

1 is a diagram illustrating a gray scale display method of a conventional plasma display panel.

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

FIG. 3 is a diagram for describing a driving method of a plasma display device in which a scan electrode line is divided into a plurality of (n) groups, and one frame is divided into a plurality of subfields for each group.

4 is a diagram illustrating an example of dividing cells of a plasma display panel into four groups according to an exemplary embodiment of the present invention.

FIG. 5 is a driving waveform diagram of a plasma display device in which the driving method described with reference to FIG. 4 according to the first exemplary embodiment of the present invention is applied to two scan electrode groups Yodd and Yeven.

6 is a driving waveform diagram of a plasma display device according to a second embodiment of the present invention.

7 is a driving waveform diagram of a plasma display device according to a third exemplary embodiment of the present invention.

The present invention relates to a plasma display device including a plasma display panel (PDP) and a driving method thereof.

A plasma display device is a flat display device that displays characters or images by using plasma generated by gas discharge. In the display panel, tens to millions or more of pixels are arranged in a matrix form according to their size.

In general, a plasma display device divides one frame into a plurality of subfields SF1-SF8 having respective weights (1T, 2T, 4T, 8T, 16T, 31T, 64T, and 128T) and time-divisionally controls them to implement gradation. Each subfield SF1-SF8 has a reset period (not shown), an address period Ad1-Ad8, and a sustain period S1-S8. The reset period is a period of initializing the state of each cell in order to perform an address operation smoothly on the cell. The address period is a wall charge on a cell (addressed cell) that is turned on to distinguish a cell that is turned on and a cell that is not turned on. This is the period during which the stacking operation is performed. The sustain period is a period in which a discharge for actually displaying an image on an addressed cell is applied by applying a sustain discharge voltage pulse.

1 is a diagram illustrating a gray scale expression method of a conventional plasma display panel.

As shown in FIG. 1, the conventional method of driving a plasma display device sequentially completes an address operation from the first scan electrode line Y1 to the last scan electrode line Yn, and then simultaneously holds all the cells in the sustain period. It is to perform the discharge operation. According to such a driving method, after an address operation is performed on one scan electrode line, the sustain discharge operation in the scan electrode line is performed only after the address operation of the last scan electrode line is completed. Therefore, there is a problem that a significant time gap occurs until the sustain discharge operation occurs in the cell in which the address operation has occurred, and the sustain discharge operation may become unstable.

Accordingly, an object of the present invention is to provide a plasma display device and a driving method thereof capable of reducing a time gap between an address operation and a sustain discharge operation. Another object of the present invention is to provide a plasma display device and a method of driving the same, which can stably perform sustain discharge of a group having a period in which a predetermined sustain discharge operation is stopped after an address operation ends.

In the plasma display panel including a plurality of scan electrodes and a plurality of sustain electrodes forming a plurality of cells according to an aspect of the present invention for solving this problem, the plurality of scan electrodes are divided into at least two groups, In the driving method of a plasma display device which divides and drives one frame into a plurality of subfields,

A sustain pulse is performed by applying a scan pulse to a scan electrode of a first group among the plurality of groups, addressing a discharge cell to be selected, and applying a sustain discharge pulse having a first potential to the discharge cell selected in the addressing step. And applying a scan pulse to a scan electrode of a second group of the plurality of groups, addressing the discharge cell to be selected, and applying a sustain discharge pulse having a second potential to the discharge cell selected in the addressing step. Performing sustain discharge, and performing sustain discharge in common to the discharge cells selected in the addressing of the first group and the second group after the sustain discharge of the second group;

The potential of the at least one sustain discharge pulse applied in the sustain period for performing the sustain discharge in common has a third potential higher than the first and second potentials.

According to another aspect of the present invention, a plasma display device includes a plasma display panel including a plurality of scan electrodes and a plurality of sustain electrodes; And a driving unit dividing the scan electrode into at least two groups and applying a driving signal to each group.

The driving unit

An address period for selecting a cell to display by applying scan pulses for each of the first and second groups in at least one subfield, and a sustain period for applying a sustain discharge pulse to sustain discharge the selected discharge cell in the address period The sustain discharge pulses applied in the sustain periods of each of the first and second groups have first and second pulse widths, respectively.

At least one sustain discharge applied during a common sustain period in which the sustain discharge is performed in common to the cells selected from the first group and the second group after the end of the sustain period of the second group, and the sustain discharge is performed in common; The pulse width of the pulse has a third pulse width longer than the first and second pulse widths.

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

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

First, a plasma display device according to an exemplary embodiment of the present invention will be described with reference to FIG. 2. 2 is a schematic conceptual diagram of a plasma display device according to an exemplary embodiment of the present invention.

As shown in FIG. 2, a plasma display device according to an exemplary embodiment of the present invention includes a plasma display panel 100, a controller 200, an address driver 300, a sustain electrode driver 400, and a scan electrode driver 500. Include. The plasma display panel 100 includes a plurality of address electrodes A1-Am arranged in the column direction, a plurality of sustain electrodes X1-Xn arranged in the row direction, and a plurality of scan electrodes Y1-Yn. do. The plurality of scan electrodes Y1-Yn and the sustain electrodes X1-Xn are arranged in pairs with each other. The discharge cells are formed by the adjacent scan electrodes, the sustain electrodes, and the address electrodes crossing them.

The controller 200 receives an image signal from the outside and outputs an address driving control signal, a sustain electrode driving control signal, and a scan electrode driving control signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield is represented by a reset period, an address period, and a sustain period. The address driver 300 receives an address drive control signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode. The sustain electrode driver 400 receives the sustain electrode driving control signal from the controller 200 and applies a driving voltage to the sustain electrode X. The scan electrode driver 500 receives a scan electrode driving control signal from the controller 200 and applies a driving voltage to the scan electrode Y.

Next, a driving method of the plasma display device according to an exemplary embodiment of the present invention will be described with reference to FIGS. 3 to 5.

FIG. 3 is a diagram for describing a driving method of a plasma display device in which a scan electrode line is divided into a plurality of (n) groups, and one frame is divided into a plurality of subfields for each group. In FIG. 3, each group is represented by a combination of eight subfields.

Meanwhile, in the method of dividing the scan electrode lines into a plurality of groups, groups may be formed by grouping a predetermined number of scan electrode lines in a physical arrangement order. For example, when the panel is formed of 800 scan electrode lines, the first to 100th scan electrode lines may be set as the first group and the 101st to 200th scan electrode lines may be set as the second group while being divided into eight groups. However, in grouping the scan electrode lines, adjacent adjacent lines may not be collected, but scan electrode lines spaced apart from each other may be gathered into the same group. That is, the first, 9, 17, ... (8k + 1) th scan electrode lines are allocated to the first group, and the second, 10, 18, ... (8k + 2) th scan electrodes are allocated to the second group. Allocating lines. On the other hand, if necessary, it is possible to group the scan electrode lines even in an irregular manner.

4 is a diagram illustrating an example in which scan electrodes of a plasma display panel according to an exemplary embodiment of the present invention are divided into four groups. One subfield consists of a reset period R, an address / sustain mixture period T1, a common sustain period T2, and a luminance correction period T3.

The reset period R initializes the wall charge state of the cell by applying reset pulses to the scan electrode lines of all groups.

The address / hold mixing period T1 sequentially performs an address operation from the first scan electrode line Y11 to the last scan electrode line Y1m in the first group G1 (AG1). When all address operations are completed with respect to the cells of the first group G1, at least one sustain pulse is applied to the first group to perform a sustain discharge operation (S11).

When the first sustain period S11 of the first group G1 ends, an address operation is performed on the cells of the second group G2 (AG2).

When the address period AG2 of the second group G2 ends, that is, when all address operations for the scan electrode lines belonging to the second group G2 are completed, the first sustain period for the second group G2 is completed. (S21) is performed. At this time, the second holding period S12 is also performed in the first group in which the address period has already been performed. However, if the gray level is satisfied by the first holding period S11 of the first group, the second holding period S12 of the first group may not be performed. Of course, the cells for which the address period has not yet been performed remain idle.

When the first sustain period S21 of the second group G2 ends, the address period AG3 and the first sustain period S31 are performed in the same manner as described above with respect to the third group G3. During the first sustain period S31 of the third group G3, the sustain periods S13 and S22 may be performed for the cells of the first and second groups G1 and G2 that have already performed the address period. . However, if the gradation level is satisfied by the first and second sustain periods S11 and S21 of the first and second groups, additional maintenance periods S13 and S22 may not be performed.

Finally, the address period AG4 and the first sustain period S41 are performed for the fourth group G4 through the above-described process, and the first sustain period S41 of the fourth group G4 is performed. During the execution, the sustain periods S14, S23, and S32 may also be performed for the cells of the first, second, and third groups G1, G2, and G3 that have already performed the address period.

4 illustrates an example in which the sustain period is performed for all the cells in the group in which the address period was previously performed while the sustain period is performed for one group of cells. At this time, assuming that the number of sustain pulses applied during the unit sustain period is the same, and thus the luminance expressed by the same is the same, the cells of the first group will exhibit n times the luminance as compared to the cells of the n-th group. Similarly, compared to the cells of the n-th group, the cells of the second group will exhibit n-1 times the luminance, and the cells of the Gn-1 group will exhibit the twice the luminance. In order to equally correct the luminance difference for each group, a predetermined additional holding period is required, which is a luminance correction period T3.

The luminance correction period T3 is a sustain discharge period that is selectively performed for each group so that the gray levels of the cells of each group are equally corrected with each other.

The common sustain period T2 is a period in which sustain pulses are commonly applied to all the cells simultaneously for a predetermined period of time, and the address / sustain mixing period T1 or the address / sustain mixing period T1 and the luminance correction period T3 May be selectively performed when the gradation diagram assigned to each subfield is not satisfied. The common holding period T2 may be performed after the address / holding mixing period T1, or may be performed after the luminance correction period T3, as shown in FIG.

In addition, the size of the common sustain period T2 may be appropriately changed according to the weight of the subfield.

In addition, one subfield may be implemented only in the address / sustain mixing period T1. Specifically, after the address operation and sustain discharge operation for one group are completed, the address operation and sustain discharge operation of another group are sequentially performed, and the address / sustainment period is sequentially performed from the first group G1 to the fourth group G4. Is performed.

5 is a driving waveform diagram of a plasma display device according to a first embodiment of the present invention. In particular, it is a drive waveform diagram in which the driving method described with reference to FIG. 4 is applied to the odd line group Yodd, the even line group Yeven, and the sustain electrode X of the scan electrode.

In the reset period R, a reset waveform is applied to the odd and even scan electrode groups Yodd and Yeven to initialize the wall charge state of the cell. Since the reset waveform of FIG. 5 is a general waveform, detailed description thereof will be omitted.

In the address / sustain mixing period T1, an address period Aodd of an odd line group Yodd is first performed, and a sustain period Sodd1 of an odd line group Yodd is performed. After the sustain period Sodd1 of the odd line group Yodd is completed, the address period Aeven of the even line group Yeven is performed. Then, the second sustain period Sodd2 of the odd line group Yodd and the first sustain period Seven of the even line group Yeven are performed together.

In the address period Aodd, a scan pulse having a VscL voltage is sequentially applied to the scan electrodes of the odd line group Yodd while the scan electrodes of the even line group Yeven are maintained at the VscH voltage. Although not shown, an address voltage is applied to an address electrode forming a cell to be selected among cells formed by a scan electrode to which a scan pulse is applied. Then, an address discharge occurs due to a difference between the address voltage applied to the address electrode and the voltage VscL applied to the scan electrode and the wall voltage caused by the wall charges formed on the address electrode and the scan electrode, thereby forming a wall voltage on the scan electrode and the sustain electrode. do.

In the sustain period Sodd1 of the address / sustain mixing period T1, a sustain discharge pulse is applied to the scan electrodes Yodd and Yeven and the sustain electrode X alternately. In FIG. 5, one sustain discharge pulse is applied to the scan electrodes Yodd and Yeven and the sustain electrode X, respectively. In addition, the sustain discharge pulse has a high level voltage (Vs voltage in FIG. 5) and a low level voltage (0V or VscH voltage in FIG. 5), and the voltage Vs or (Vs-VscH) may cause sustain discharge along with the wall voltage. That is the voltage. First, a Vs voltage is applied to the scan electrodes Yod and Yeven and 0 V is applied to the sustain electrode X, and a wall is formed between the scan electrode Yodd and the sustain electrode X by the address discharge in the address period Aodd. In the cell in which the voltage is formed, sustain discharge occurs due to the wall voltage, the voltage difference Vs between the scan electrode Yodd and the sustain electrode X, and a wall voltage of opposite polarity is formed between the scan electrode and the sustain electrode. On the other hand, the sustain discharge pulse is also applied to the scan electrodes of the even-numbered line group Yeven during the sustain period Sodd1 of the address / sustain mixing period T1, but a wall voltage is formed between the scan electrode Yeven and the sustain electrode X. There is no maintenance discharge. As such, when the address period Aodd and the sustain period Sodd1 of the address / sustain mixing period T1 are completed for the scan electrodes of the odd line group YG1, the addresses of the scan electrodes of the even line group Yeven are subsequently The address period Aeven of the / hold mixing period T1 is performed.

For the scan electrodes of the even-numbered line group YG2, in the address period Aeven of the address / sustain mixing period T1, the scan electrodes Yeven are sequentially arranged while the other scan electrode Y is kept at the VscH voltage. A scan pulse with a VscL voltage is applied. As described above, the wall voltage is formed by applying the address voltage to the address electrode A forming the cell to be selected from the cells formed by the scan electrode Y to which the VscL voltage is applied. In FIG. 5, although a part of the sustain period Sodd1 and a part of the address period Aeven overlap, the two periods Sodd1 and Aeven may be separated.

In the sustain periods Sodd2 and Seven of the address / sustain mixing period T1, a sustain discharge pulse having a Vs voltage and a 0V voltage is applied to the scan electrodes Yodd and Yeven and the sustain electrode X alternately. Then, sustain discharge occurs in a cell in which the wall voltage is formed in the address period Aeven among the cells of the even line group Yeven and in a cell in which the wall voltage is formed in the address period Aodd among the cells of the odd line group Yodd. That is, the sustain period Seven of the address / sustain mixing period T1 of the even line group Yeven and the second sustain period Sodd2 of the address / sustain mixing period T1 of the odd line group Yodd are performed simultaneously. do.

In the next luminance correction period T3, an additional sustain period is given for the cells of the even line group Yeven so that the cells of the odd line group Yodd and the even line group Yeven have the same luminance. That is, in the luminance correction period T3, the discharge is prevented from occurring in the cells of the odd line group Yodd, and the discharge occurs only in the cells of the even line group Yeven. To this end, when the sustain discharge pulse of the voltage Vs is applied to the sustain electrode X, the VL2 voltage between the Vs voltage and the 0 V voltage is applied to the odd line group scan electrode Yodd and the ground voltage is applied to the even line group scan electrode Yeven. Apply (0V). Then, in the odd line group Yodd, the voltage difference between the scan electrode Yodd and the sustain electrode X does not reach the discharge start voltage, so that discharge does not occur and sustain discharge occurs only in the cells of the even line group. In this case, a voltage equal to the voltage of the sustain discharge pulse (Vs voltage in FIG. 5) applied to the sustain electrode X may be applied to the odd line group scan electrode Yodd instead of the VL2 voltage between the Vs voltage and the 0V voltage. have. Then, 0 V is applied to the sustain electrode X, and a Vs voltage is applied to the scan electrodes of the odd line group Yodd and the even line group Yeven. Then, since there is no previous sustain discharge in the cells of the odd line group Yodd, the wall voltage is formed to be reverse polarity, so that sustain discharge does not occur, and sustain discharge occurs in the cells of the even line group Yeven. In this manner, the number of sustain discharges in the odd line group Yodd is limited by the number of sustain discharges in the sustain period Sodd1 of the address / sustain mixing period T1, so that the odd line group Yodd and the even line group Yeven Are made equal.

Then, sustain discharge pulses are applied to the odd and even line group scan electrodes Yodd and Yeven and sustain electrode X in the common sustain period T2 to perform sustain discharge in common for the two groups Yodd and Yeven. do.

Therefore, in the subfield of FIG. 5, the five discharges are performed on the odd line group Yodd and the even line group Yeven.

However, according to the same driving method as in the first embodiment of the present invention, in the odd line group Yodd, the address operation is first performed in the address period Aodd and the sustain discharge operation is performed in the sustain period Sodd1. In Aeven, no operation is performed while performing the address operation of the even line group Yeven. Then, after performing the sustain discharge operation in the sustain periods (Sodd2, Seven) again, in the luminance correction period (T3), no common operation is performed in the common maintenance period (T2) without performing any operation.

On the other hand, in the even line group Yeven, the address operation is performed in the address period Aeven, and then the sustain discharge operation is performed in the sustain periods Sodd2 and Seven and the luminance correction period T3. T2) performs a common lipophilic operation.

Therefore, in the odd line group Yodd, the sustain discharge occurs first and the sustain discharge operation is stopped in the middle, and the priming particles may disappear during the sustain discharge operation. Then, when the sustain discharge is performed next, the sustain discharge becomes weak due to the lack of priming particles, so that the luminance may be lowered compared to the even line group Yeven. Therefore, an embodiment in which the luminance in the odd line group Yodd may be compensated will be described with reference to FIG. 6.

6 is a driving waveform diagram of a plasma display device according to a second embodiment of the present invention. The driving waveform according to the second embodiment of the present invention has a voltage level of the first sustain discharge pulse of the common sustain period T2 higher than that of the sustain discharge pulse before the common sustain period T2. Except for the point of application, all of the same waveform is duplicated, so the description is omitted.

According to the second embodiment of the present invention, as shown in FIG. 6, the first sustain discharge pulse of the common sustain period T2, that is, the sustain discharge pulse voltage Vs1 applied to the sustain electrode X in FIG. It is applied higher than the level Vs of the sustain discharge pulse voltage applied in the sustain periods Sodd and Seven of the odd line group Yodd and the even line group Yeven before the common sustain period T2. Then, the discharge stability of the sustain discharge in the odd and even line groups Yodd and Yeven corresponding to the sustain electrode X can be ensured. In particular, since the sustain discharge occurs after the address period Aodd is performed before the even line group Yeven, and the sustain discharge operation is stopped before the common sustain period T2 is performed, the priming particles The sustain discharge in the common sustain period T2 can be efficiently performed by securing the discharge stability in the odd line group Yodd which is in the insufficient state.

Meanwhile, in the second embodiment of the present invention, it has been described that the voltage level of the first sustain discharge pulse is higher than the level of the sustain discharge pulse voltage applied in the previous sustain period in the common sustain period T2. The present invention is not limited thereto, and the third embodiment of the present invention, in which the same effect as the second embodiment of the present invention can be obtained, is described in detail.

7 is a driving waveform diagram of a plasma display device according to a third exemplary embodiment of the present invention.

As shown in FIG. 7, the driving waveforms according to the third exemplary embodiment of the present invention are the same except for the first sustain discharge pulse applied to the sustain electrode X in the common sustain period T2. Is omitted.

According to the third embodiment of the present invention, the pulse width W2 of the first sustain discharge pulse among the sustain discharge pulses applied to the sustain electrode X in the common sustain period T2 is defined as the odd-numbered line group before the common sustain period ( Yodd) and the sustain discharge pulse width W1 applied in the sustain periods Sodd and Seven of the even line group Yeven. By doing this, it is possible to ensure the discharge stability of the sustain discharge in the odd and even line groups Yodd and Yeven corresponding to the sustain electrode X. In particular, since the sustain discharge occurs after the address period Aodd is performed before the even line group Yeven, and the sustain discharge operation is stopped before the common sustain period T2 is performed, the priming particles The sustain discharge in the common sustain period T2 can be efficiently performed by securing the discharge stability in the odd line group Yodd which is in the insufficient state.

In addition, the slope of the first sustain discharge pulse applied to the sustain electrode X in the common sustain period T2 is different from the slope of the sustain discharge pulse applied to the sustain period Sodd of the odd line group Yodd. Even if adjusted, the same effect as the 2nd and 3rd Example of this invention can be acquired. That is, even if the slope of the first sustain discharge pulse applied to the sustain electrode X in the common sustain period T2 is greater than the slope of the sustain discharge pulse applied to the sustain period Sodd of the odd line group Yodd. The same effects as in the second and third embodiments of the present invention can be obtained.

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

As described above, according to the present invention, the cells constituting the display panel can be driven in a plurality of groups without the addition of a driving circuit. In addition, when the cells constituting the display panel are divided into a plurality of groups without the addition of a driving circuit, and the gray level is expressed in a frame-subfield method, the temporal gap between the address period and the sustain period is minimized so that the sustain period is smooth. Maintenance discharge can occur.

Further, by applying the first sustain discharge pulse applied in the common sustain period among the plurality of sustain periods differently from the sustain discharge pulse applied in the sustain period of the group which first performed the address period before the common sustain period, the address period is first applied. It can be carried out to ensure the stability of the maintenance discharge in the common maintenance period of the group in the lack of priming particles.

Claims (9)

In a plasma display panel including a plurality of scan electrodes and a plurality of sustain electrodes forming a plurality of cells, the plurality of scan electrodes are divided into at least two groups, and one frame is divided into a plurality of subfields to drive the plasma display. In the driving method of the device, Addressing a discharge cell to be selected by applying a scan pulse to a scan electrode of a first group of the plurality of groups; Performing sustain discharge by applying a sustain discharge pulse having a first potential to the discharge cells selected in the addressing step; Addressing a discharge cell to be selected by applying a scan pulse to a scan electrode of a second group of the plurality of groups; Performing sustain discharge by applying a sustain discharge pulse having a second potential to the discharge cells selected in the addressing step; And After the sustain discharge step of the second group, performing the sustain discharge in common to the discharge cells selected in the addressing step of the first group and the second group, And a potential of at least one sustain discharge pulse applied in the sustain period during which the sustain discharge is commonly performed has a third potential higher than the first and second potentials. The method of claim 1, In the step of performing the maintenance discharge in common, And the at least one sustain discharge pulse is the first sustain discharge pulse applied during the sustain period during which the sustain discharge is commonly performed. The method of claim 1, The sustain discharge pulses applied during the sustain period of each of the first group and the second group have first and second pulse widths, respectively. In the step of performing the maintenance discharge in common, The pulse width of the at least one sustain discharge pulse has a third pulse width longer than the first and second pulse widths of the sustain discharge pulses applied during the sustain periods of the first group and the second group, respectively. Method of driving. The method of claim 1, The sustain discharge step of the second group Simultaneously performing sustain discharge on the discharge cells selected in the addressing step of the first group and the discharge cells selected in the addressing step of the second group; And And performing sustain discharge only in the discharge cells selected in the addressing step of the second group. A plasma display panel including a plurality of scan electrodes and a plurality of sustain electrodes; And A driving unit for dividing the scan electrodes into at least two groups and applying a driving signal to each group; The driving unit In at least one subfield An address period for selecting a cell to be displayed by applying scan pulses to each of the first and second groups, and a sustain period for applying a sustain discharge pulse to sustain discharge the selected discharge cell in the address period; The sustain discharge pulses applied in the sustain periods of each of the first and second groups have first and second pulse widths, respectively. At least one sustain discharge applied during a common sustain period in which the sustain discharge is performed in common to the cells selected from the first group and the second group after the end of the sustain period of the second group, and the sustain discharge is performed in common; And a pulse width of the pulse has a third pulse width longer than the first and second pulse widths. The method of claim 5, And the at least one sustain discharge pulse applied during the common sustain period is a first sustain discharge pulse applied during the common sustain period. The method of claim 5, In the sustain period of each of the first and second groups, sustain discharge pulses of the first and second potentials are applied, respectively. After the end of the sustain period of the second group, the potential of the at least one sustain discharge pulse applied during the common sustain period which performs the sustain discharge in common to the cells selected from the first group and the second group is equal to the first and the second. And a third potential higher than the first and second potentials of the sustain discharge pulses applied in each of the two sustain periods. The method of claim 5, In the sustain period of each of the first and second groups, a sustain discharge pulse having a first and a second slope is applied, respectively. After the end of the sustain period of the second group, the slope of the at least one sustain discharge pulse applied during the common sustain period which performs the sustain discharge in common to the cells selected from the first group and the second group is the first and the second. And a third slope higher than the first and second slopes of the sustain discharge pulses applied in the respective sustain periods of the two groups. The method of claim 5, The maintenance period of the second group is, A first period in which sustain discharge is simultaneously performed in a cell selected in the address period of the first group and a discharge cell selected in the address period of the second group; And And a second period in which sustaining discharge is performed only in a cell selected in the address period of the second group.

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