KR20080043539A - Plasma display device and driving method thereof - Google Patents

Abstract

A plasma display device and a driving method thereof are provided to reduce power consumption of the display device by suppressing peak current due to turn-on/off operations of a switch. A plasma display device includes a PDP(Plasma Display Panel), a controller(200), and a driver(300,400). The controller includes an image signal processor(210) which detects a vertical synchronous frequency of an external image signal, and a mode determining unit(220) which determines a driving mode according to the vertical synchronous frequency of the external image signal. The driving unit applies a driving voltage to the PDP according to a driving control signal. During a first mode, the driver detects a first vertical synchronous frequency in the image signal processor and generates a control signal for driving plural sub-fields in one frame synchronously with the first vertical synchronous frequency. During a second mode, the driver generates a control signal for driving in a transient period, when a variation in the vertical synchronous frequency is detected in the mode determining unit. During a third mode, the image signal processor detects a second vertical synchronous frequency, and the driver generates the control signal for driving the sub-fields in one frame synchronously with the second vertical synchronous signal. The driving unit repeatedly applies reset rising pulses and reset falling pulses to plural electrodes.

Description

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

1 illustrates a conceptual diagram of a plasma display device according to an exemplary embodiment of the present invention.

FIG. 2 is a block diagram of a controller related to a change in vertical synchronization frequency of an external image signal in the plasma display device according to an exemplary embodiment of the present invention.

3 illustrates a logic process and subfield generation when a vertical synchronizing frequency of an external image signal varies from 60 Hz to 50 Hz in a plasma display device according to an exemplary embodiment of the present invention.

4 shows driving waveforms in the transition period according to the first embodiment of the present invention.

5 shows driving waveforms in the transition period according to the second embodiment of the present invention.

6 shows driving waveforms in the transition period according to the third embodiment of the present invention.

7 shows driving waveforms in the transition period according to the fourth embodiment of the present invention.

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

The plasma display device is a flat display device that displays characters or images by using plasma generated by gas discharge. In the display panel of the plasma display device, tens to millions or more of discharge cells (hereinafter, referred to as "cells") are arranged in a matrix form according to their size. The plasma display device configured as described above receives an image signal from the outside and selectively emits the plurality of cells to display image data input as an electric signal.

In general, a plasma display device drives by dividing one frame into a plurality of subfields having respective gray scale weights. In this case, the luminance of the cell is determined by a sum of weights of at least one subfield emitted by the corresponding cell among the plurality of subfields.

Each subfield consists of a reset period, an address period, and a sustain period. The reset period is a period for initializing the state of the discharge cells, and the address period is a period for selecting light emitting cells and non-light emitting cells among the discharge cells. The sustain period is a period in which an image is displayed by sustaining and discharging the cell selected as the light emitting cell in the address period by the number of times determined corresponding to the weight of the subfield.

On the other hand, a video signal input from the outside (hereinafter, referred to as an "external video signal") is generally divided into a NTSC (National Television Standard Committee) video signal and a PAL (Phase Alternating by Line) video signal according to a vertical synchronization frequency. . Here, the vertical synchronization frequency of the NTSC video signal is 58 Hz to 60 Hz (hereinafter referred to as 60 Hz), and the vertical synchronization frequency of the PAL video signal is 48 Hz to 52 Hz (hereinafter referred to as 50 Hz). That is, since the vertical synchronization frequency of the NTSC video signal is 60 Hz, the time allotted to one frame at the time of driving according to the NTSC video signal is 16.67 ms (= 1/60 second). On the other hand, since the vertical synchronization frequency of the PAL video signal is 50 Hz, the time allotted to one frame during driving according to the PAL video signal is 20 ms (= 1/50 second).

As described above, since a frame at the time of driving according to the PAL video signal is allocated a longer time than a frame at the time of driving the NTSC video signal, the driving according to the NTSC video signal is performed for the purpose of preventing flicker when driving the PAL video signal. A different subfield arrangement is required. The plasma display device is designed to determine a vertical synchronizing frequency of an external image signal and operate in a different driving mode according to the vertical synchronizing frequency.

On the other hand, while the plasma display device is being driven, the NTSC video signal may be input suddenly and then the PAL video signal may be suddenly input, or conversely, the PAL video signal may be suddenly input and then the NTSC video signal may be suddenly input.

In the plasma display device according to the related art, when the vertical synchronizing frequency of the input external video signal fluctuates, the transient state is set before operating in the driving mode corresponding to the changed vertical synchronizing frequency.

The plasma display device according to the related art does not generate any control signal so as not to display the screen in the transition period, thereby preventing occurrence of screen flicker or gray scale due to the variation of the vertical synchronization frequency.

However, according to the prior art, during the transition period in which no control signal is generated so that no driving voltage is applied to the cell, the space charge inside the cell may disappear and the wall charge may be lost. As a result, reset discharge for initializing the wall charge state does not occur properly when driving according to the changed vertical synchronization frequency, and thus an incorrect discharge that does not stably perform an address discharge for selecting a cell to be discharged may occur. There is this.

Disclosure of Invention The present invention is to solve the problems of the prior art, and when the vertical synchronization frequency of an image signal input from the outside is changed, a plasma display device capable of preventing mis-discharge when driving according to the changed vertical synchronization frequency and its driving The technical problem is to provide a method.

According to an aspect of the present invention, a method of driving a plasma display device which displays an external image signal received from an external device and includes a plurality of electrodes, wherein (a) when an external image signal having a first vertical synchronization frequency is inputted, Driving one frame into a plurality of subfields in synchronization with the first vertical synchronization frequency; (b) when an external image signal having a second vertical synchronization frequency is input, driving one frame into a plurality of subfields in synchronization with the second vertical synchronization frequency; And (c) if an external video signal having the second vertical synchronization frequency is input during step (a), setting a transient period before step (b). In this case, the process of applying a reset rising waveform that gradually rises to the plurality of electrodes in the transient period and then applying a reset falling waveform that gradually falls is repeated at least one time.

In step (c), before setting the transient period, it is determined whether an external video signal having the second vertical synchronization frequency is input for a predetermined period, and the external video signal having the second vertical synchronization frequency is inputted to the second image. And dividing and driving one frame into a plurality of subfields in synchronization with one vertical synchronization frequency.

Here, the reset rising waveform is a voltage waveform gradually rising from the sustain voltage to the first voltage, and the reset falling waveform is a voltage waveform gradually falling from the sustain voltage to the second voltage, or the reset rising waveform is greater than the sustain voltage. The voltage waveform gradually rising from the low non-scanning voltage to the first voltage may be a voltage waveform gradually decreasing from the non-scanning voltage to the second voltage.

In some periods including the end point of the transient period during the transient period, the applying of the reset rising waveform and the reset falling waveform to the plurality of electrodes may be repeated at least one time. The external video signal having the first vertical synchronization frequency is an NTSC video signal, and the external video signal having the second vertical synchronization frequency is a PAL video signal.

According to another feature of the present invention, in the driving method of a plasma display device which displays an external image signal received from the outside and includes a plurality of electrodes, (a) when an external image signal having a first vertical synchronization frequency is inputted, Driving one frame into a plurality of subfields in synchronization with the first vertical synchronization frequency; (b) when an external image signal having a second vertical synchronization frequency is input, driving one frame into a plurality of subfields in synchronization with the second vertical synchronization frequency; And (c) if an external image signal having the second vertical synchronizing frequency is input during the step (a), setting the transient period before the step (b). At this time, the voltage difference between the plurality of first electrodes and the plurality of second electrodes is maintained at the sustain voltage in the transient period.

And dividing and driving one frame into a plurality of subfields in synchronization with the first vertical synchronizing frequency of the external image signal having the second vertical synchronizing frequency between steps (b) and (c). do.

In addition, a second voltage is applied to the plurality of second electrodes in a state in which a first voltage is applied to the plurality of first electrodes immediately before the transient period starts, and the plurality of first electrodes are connected to the first electrodes in the transition period. Biasing the voltage and biasing the plurality of second electrodes to the second voltage, wherein a difference between the first voltage and the second voltage is the sustain voltage.

According to another aspect of the present invention, a plasma display device includes a plasma display panel including a plurality of electrodes, an image signal processor for detecting a vertical synchronization frequency of an external image signal input from an external device, and a vertical synchronization frequency of the external image signal. And a control unit including a mode determination unit determining a driving mode according to the driving mode, and a driving unit applying a driving voltage to the plasma display panel according to the driving control signal.

The control unit may include a first mode that detects a first vertical synchronizing frequency in the image signal processing unit and generates a control signal for driving a frame into a plurality of subfields in synchronization with the first vertical synchronizing frequency. When the mode determiner detects a change in the vertical synchronizing frequency, the second mode generates a control signal for driving in the transient period and the image signal processor detects a second vertical synchronizing frequency and synchronizes with the second vertical synchronizing frequency. In this case, an operation including a third mode of generating a control signal for dividing and driving one frame into a plurality of subfields is performed.

The driving unit repeatedly applies a reset rising waveform gradually rising and a reset falling waveform gradually falling to the plurality of electrodes in the transient period.

The controller may determine whether a second vertical synchronization frequency is detected by the image signal processor during a first period when the mode determiner detects a change in the vertical synchronization frequency from the first vertical synchronization frequency to the second vertical frequency. And a fourth mode of generating a control signal for driving one frame into a plurality of subfields in synchronization with the first vertical synchronizing frequency during the first period, and then performing the third mode.

The reset rising waveform may be a voltage waveform gradually rising from the sustain voltage to the first voltage, and the reset falling waveform may be a voltage waveform gradually falling from the sustain voltage to the second voltage, or the reset rising waveform. May be a voltage waveform gradually rising from the first voltage lower than the sustain voltage to the second voltage, and the reset falling waveform may be a voltage waveform gradually falling from the first voltage to the third voltage. The driving unit may apply the reset rising waveform and the reset falling waveform to the plurality of electrodes in a second period including the end time of the transient period during the transient period.

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, and like reference numerals designate like parts 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.

1 illustrates a conceptual diagram of a plasma display device according to an exemplary embodiment of the present invention.

As shown in FIG. 1, a plasma display device according to an exemplary embodiment of the present invention includes a plasma display panel 100, a controller 200, an address electrode driver 300, a scan electrode driver 400, and a sustain electrode driver 500. ). The plasma display panel 100 includes a plurality of address electrodes A1-Am (hereinafter referred to as "A electrodes") extending in a column direction, and a plurality of sustain electrodes X1-Xn (hereinafter referred to as "X electrodes") extending in a row direction. Electrodes ") and a plurality of scan electrodes Y1-Yn (hereinafter referred to as" Y electrodes "). The plurality of Y electrodes Y1-Yn and the X electrodes X1-Xn are arranged in pairs with each other. The discharge cell 12 is formed where the adjacent Y electrodes Y1-Yn, the X electrodes X1-Xn and the A electrodes A1-Am cross each other.

The controller 200 receives an image signal (hereinafter, referred to as an “external image signal”) from the outside, detects a vertical synchronization frequency of the external image signal, sets a driving mode corresponding to the vertical synchronization frequency, and provides one frame. Generates a control signal for driving by dividing into a plurality of subfields having respective weights. Also, an address electrode driving control signal, a sustain electrode driving control signal, and a scan electrode driving control signal for displaying the external image signal are output.

The address electrode driver 300 receives an address electrode driving control signal from the controller 200 and applies a signal for selecting a discharge cell to be displayed to each of the A electrodes A1-Am. The scan electrode driver 400 receives a scan electrode drive control signal from the controller 200 to apply a drive voltage to the Y electrodes Y1-Yn, and the sustain electrode driver 500 controls the sustain electrode drive from the controller 200. The signal is received and a driving voltage is applied to the X electrodes X1-Xn.

Hereinafter, a plasma display device and a driving method thereof capable of preventing mis-discharge during driving according to the changed vertical synchronization frequency when the vertical synchronization frequency of the external video signal is changed will be described.

FIG. 2 is a block diagram of the controller 200 related to the variation of the vertical synchronization frequency of the external image signal in the plasma display device according to the exemplary embodiment of the present invention. In FIG. 2, the illustration of a portion not directly related to the variation of the vertical synchronization frequency of the external video signal is omitted.

As shown in FIG. 2, the controller includes an image signal processor 210 and a mode determiner 220.

The image signal processor 210 performs basic signal processing, that is, gamma correction and error diffusion processing, on the external image signal input from the outside, and outputs RGB image data corresponding to the external image signal. The video signal processor 210 detects a vertical synchronization frequency from the external video signal, and outputs a frequency determination signal according to whether the external video signal is a 50 Hz PAL video signal or a 60 Hz NTSC video signal.

The mode determination unit 220 determines a driving mode corresponding to the vertical synchronization frequency according to the frequency determination signal, and outputs a driving mode control signal. For example, the driving mode control signal is logically set to a high level in the case of the driving mode according to the PAL video signal (hereinafter referred to as the 'PAL driving mode'), and the driving mode according to the NTSC video signal (hereinafter, ' NTSC driving mode ”may be logically set to a low level.

In addition, the mode determination unit 220 determines whether the frequency determination signal is fluctuated, and if the frequency determination signal is fluctuating, determines whether the frequency determination signal fluctuated for a predetermined period from the time when the frequency determination signal is fluctuated is continuously input. do. Here, the predetermined period is a period that can be predicted that the continuously changed frequency determination signal will be input in the future, and is obtained through an experimental method, and the detailed method thereof can be easily understood by those skilled in the art. Is omitted.

If the frequency determination signal continuously changed for a predetermined period from the time when the frequency determination signal is changed, the mode determination unit 220 generates a transition control signal and a mode control signal according to the changed vertical synchronization frequency after the end of the predetermined period. Output At this time, when the transient setting signal is output from the mode determining unit 220, the driving units 300 to 500 respectively apply a reset waveform to the Y electrode to generate a reset discharge in the cell, or to each electrode to maintain the wall voltage of the cell. A bias voltage of may be applied.

Alternatively, the mode determiner 220 may output a transition setting signal and a mode control signal according to the changed vertical synchronization frequency at the time when the frequency determination signal changes.

3 illustrates a logic process and subfield generation when an external video signal changes from an NTSC video signal to a PAL video signal in the plasma display device according to an exemplary embodiment of the present invention.

As shown in FIG. 3, when the external video signal is an NTSC video signal, the video signal processor 210 outputs a frequency determination signal (hereinafter referred to as an NTSC frequency determination signal) corresponding to the NTSC video signal. The mode determination unit 220 outputs a mode control signal (hereinafter referred to as an NTSC mode control signal) corresponding to the NTSC driving mode. In FIG. 3, the NTSC frequency determination signal is illustrated as being at a high level, and the NTSC mode control signal is illustrated as being at a low level.

On the other hand, when an NTSC video signal is input as an external video signal and a PAL video signal is input (indicated at (a) in FIG. 3), the video signal processor 210 determines a frequency determination signal corresponding to the PAL video signal (hereinafter, ' PAL frequency determination signal). When the mode determination unit 220 receives the PAL frequency determination signal, the mode determination unit 220 detects that the frequency determination signal is changed from the NTSC frequency determination signal to the PAL frequency determination signal, and continuously determines the PAL frequency from the time point (a) until the mode determination period. Examine whether or not a signal is input. Here, the period allocated to the mode determination period is a period that can be predicted to continuously input the PAL frequency determination signal in the future, and can be obtained through an experimental method, and specific methods thereof can be easily understood by those skilled in the art. , A detailed description thereof will be omitted. 3, the PAL frequency determination signal is shown as having a low level.

In the meantime, the mode control signal is maintained as an NTSC mode control signal. Since the PAL image signal can be determined to be input due to an instantaneous problem, it operates in the NTSC driving mode in the mode determination period.

If the PAL frequency determination signal is continuously input during the mode determination period, the mode determination unit 220 outputs the PAL mode control signal and the transition setting signal at the end of the mode determination period (time point (b)). In FIG. 3, the PAL mode control signal is shown to be at a high level, and the transient setting signal is shown to be at a low level during the transition period.

Thereafter, when the transition period ends ((c) time point), if the mode determination unit 220 sets the transition setting signal to a high level, the plasma display device operates in the PAL driving mode according to the PAL image signal.

According to an embodiment of the present invention, a reset waveform is applied to allow the wall charge state of the cell to be initialized in the transition period, or the voltage of each electrode is maintained at the respective bias voltage so that the wall voltage between each electrode is maintained. In this case, in the PAL driving mode, a reset discharge for initializing a wall charge state of each cell or an address discharge for selecting a cell to be sustained discharged in a corresponding subfield can be stably generated.

In addition, although not shown separately, the transient setting signal may be immediately output when the PAL image signal is input for fast driving. That is, since the PAL video signal is driven in the NTSC mode during the mode determination period, the video signal may be unstable. Therefore, when the PAL video signal is input, the mode determination period may be omitted and the transient setting signal may be output.

However, if the mode determination period is configured before outputting the transient setting signal, the plasma display device can be driven more stably when the vertical synchronizing frequency is changed than when there is no mode determination period.

Hereinafter, each embodiment of the present invention according to the voltage waveform applied to each electrode in the transition period will be described with reference to FIGS. 4 to 7.

4 shows driving waveforms in the transition period according to the first embodiment of the present invention. According to the first embodiment, the process of applying a reset rising waveform that gradually rises to the Y electrode in the transition period and then applying a reset falling waveform that gradually falls is repeated at least one time.

That is, as shown in FIG. 4, in the transition period, the sustain voltage (“Vs” in FIG. 4) is applied to the Y electrode while a reference voltage (shown as “0 V” in FIG. 4) is applied to the X electrode and the A electrode. Applying a reset rising waveform that gradually rises from the reset maximum voltage (shown as "(Vs + Vset)" in FIG. 4) to the A and X electrodes, respectively. In the state of Fig. 4, the process of applying the reset falling waveform gradually descending from the sustain voltage to the reset minimum voltage (shown as "Vnf" in Fig. 4) is applied to the Y electrode. Repeat. Here, the sustain voltage has the same voltage level as the sustain discharge pulse of the high voltage level applied alternately to the X electrode and the Y electrode in the sustain period.

As described above, according to the first embodiment, since the wall charge state of each cell is initialized during the transition period, the space charge inside the cell can be prevented from disappearing and the wall charges formed in each electrode can be prevented from being lost. In the mode, reset discharge and address discharge can stably occur.

On the other hand, as the reset maximum voltage is lower, the absolute value of the voltage level of the reset minimum voltage may be smaller, thereby reducing the stress of the driving circuit.

5 shows driving waveforms in the transition period according to the second embodiment of the present invention. According to the second embodiment, the start voltage of the reset rising waveform and the start voltage of the reset falling waveform are set to a non-scan voltage (shown as "VscH" in FIG. 6) lower than the sustain voltage. Here, the non-scanning voltage is a voltage applied to the plurality of Y electrodes except for at least one Y electrode to which the scan voltage applied sequentially is applied in the address period. Since the second embodiment is the same as or similar to the first embodiment, redundant descriptions thereof will be omitted.

As shown in FIG. 6, according to the second embodiment, in the transient state, at a non-scan voltage to the Y electrode in a state in which a reference voltage (shown as “0 V” in FIG. 6) is applied to the X electrode and the A electrode. Applying a reset rising waveform that gradually rises to the reset maximum voltage (shown as "(VscH + Vset)" in FIG. 6) and the reference and bias voltages ("Ve" in FIG. ), The process of applying a reset falling waveform that gradually descends from the non-scan voltage to the reset minimum voltage (shown as "(Vnf ')" in FIG. 6) is repeatedly applied to the Y electrode. do.

As described above, according to the second embodiment, not only the wall charge state of each cell is initialized in the transition period, but also the stress applied to the driving circuit can be reduced by lowering the absolute values of the voltage levels of the reset highest voltage and the reset minimum voltage. The stability of the circuit can be improved.

On the other hand, according to the first embodiment and the second embodiment, since the reset discharge is generated in the plurality of cells during the entire period allocated to the transition period, the contrast can be lowered.

6 shows driving waveforms in the transition period according to the third embodiment of the present invention. According to the third embodiment, the reset discharge is generated in the plurality of cells only during the partial period Tr including the end point of the transition period in the transition period. Since the third embodiment is the same as or similar to the first embodiment or the second embodiment except that only a part of the transition period causes the reset discharge, a redundant description will be omitted.

That is, as illustrated in FIG. 6, the process of applying the reset rising waveform and applying the reset falling waveform to the Y electrode is repeated at least one time in the Tr period of the transition period. Here, the start voltage of the reset rising waveform and the start voltage of the reset falling waveform may be sustain voltages or non-scan voltages.

In this way, not only the wall charge state of each cell is initialized before the PAL driving mode is started, but also reset discharge is generated only in a part of the transition period, thereby preventing the lowering of the contrast and reducing unnecessary power consumption. .

On the other hand, according to the first to third embodiments, as the progressively changing reset waveform is applied to the Y electrode in the transition period, discharge is continuously generated to lower the contrast, use a high voltage, and switch on the circuit. Peak currents occur during off, resulting in high power consumption in the transient period.

7 shows driving waveforms in the transition period according to the fourth embodiment of the present invention. According to the fourth embodiment, the sustain voltage is applied to any one of the Y electrode and the X electrode in the transition period, and the reference voltage is applied to the remaining electrodes.

That is, in the sustain period of the last subfield just before the transition begins, the voltage applied last to the X electrode and the voltage applied last to the Y electrode are maintained at the transition voltages of the X electrode and the Y electrode, respectively.

FIG. 7 illustrates a case where a reference voltage is last applied to the X electrode and a sustain voltage is last applied to the Y electrode in the sustain period of the last subfield just before the transition begins. Here, in the transient period, the voltage of the X electrode is maintained at the reference voltage, and the voltage of the Y electrode is maintained at the sustain voltage. In addition, since the voltage of the A electrode is maintained at the reference voltage in the sustain period, the voltage of the A electrode is maintained at the reference voltage even in the transition period.

In this way, since the fluctuation of the wall voltage does not occur in the transition period, discharge does not occur between the X electrode and the Y electrode, between the X electrode and the A electrode, and between the Y electrode and the A electrode. However, since a voltage is applied to each electrode, wall charges formed on each electrode are maintained without being lost. Therefore, after the transition period ends, the wall charges necessary for the reset discharge and the address discharge are maintained properly, so that the reset discharge and the address discharge can be stably generated. And since discharge does not generate | occur | produce in a transition period, the fall of contrast can be prevented.

In addition, since the voltage applied to each electrode is not changed during the transition period, the generation of peak current according to the turn-on-turn-off operation of the switch is reduced, thereby reducing power consumption.

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

According to the present invention, when a video signal having a different vertical synchronizing frequency is input and the driving drive mode is changed, it is possible to prevent erroneous discharge in the changed driving drive mode.

Claims (19)

In the driving method of a plasma display device which displays an external video signal received from the outside and includes a plurality of electrodes, (a) when an external image signal having a first vertical synchronization frequency is input, driving one frame into a plurality of subfields in synchronization with the first vertical synchronization frequency; (b) when an external image signal having a second vertical synchronization frequency is input, driving one frame into a plurality of subfields in synchronization with the second vertical synchronization frequency; Including, (c) if an external video signal having the second vertical synchronization frequency is input during step (a), setting a transient period before step (b); And applying a reset rising waveform that gradually rises and then gradually applying a reset rising waveform to the plurality of electrodes in the transient period, at least one or more times. The method of claim 1, In the step (c), before setting the transient period, it is determined whether an external video signal having the second vertical synchronization frequency is input for a predetermined period, and the external video signal having the second vertical synchronization frequency is input to the first. And driving one frame divided into a plurality of subfields in synchronism with the vertical synchronizing frequency. The method according to claim 1 or 2, The reset rising waveform is a voltage waveform gradually rising from the sustain voltage to the first voltage, and the reset falling waveform is a voltage waveform gradually falling from the sustain voltage to the second voltage. The method of claim 3, And applying the reset rising waveform and the DPP reset falling waveform to the plurality of electrodes at least one or more times in the partial period including the end point of the transient period during the transient period. The method of claim 3, And the external video signal having the first vertical synchronization frequency is an NTSC video signal, and the external video signal having the second vertical synchronization frequency is a PAL video signal. The method according to claim 1 or 2, The reset rising waveform is a voltage waveform gradually rising from the non-scanning voltage lower than the sustain voltage to the first voltage, and the reset falling waveform is a voltage waveform gradually falling from the non-scanning voltage to the second voltage. Driving method. The method of claim 6, And applying the reset rising waveform and the reset falling waveform to the plurality of electrodes at least one or more times in the partial period including the end point of the transient period during the transient period. The method of claim 7, wherein And the external image signal having the first vertical synchronization frequency is an NTSC signal, and the external image signal having the second vertical synchronization frequency is a PAL image signal. In the driving method of a plasma display device which displays an external video signal received from the outside and includes a plurality of electrodes, (a) when an external image signal having a first vertical synchronization frequency is input, driving one frame into a plurality of subfields in synchronization with the first vertical synchronization frequency; (b) when an external image signal having a second vertical synchronization frequency is input, driving one frame into a plurality of subfields in synchronization with the second vertical synchronization frequency; Including, (c) if an external video signal having the second vertical synchronization frequency is input during step (a), setting a transient period before step (b); And a voltage difference between the plurality of first electrodes and the plurality of second electrodes at a sustain voltage during the transient period. The method of claim 9, And driving the external image signal having the second vertical synchronization frequency by dividing one frame into a plurality of subfields in synchronization with the first vertical synchronization frequency between steps (b) and (c). A method of driving a plasma display device. The method of claim 9 or 10, A second voltage is applied to the plurality of second electrodes while a first voltage is applied to the plurality of first electrodes just before the transient period begins, Biasing the plurality of first electrodes to the first voltage and biasing the plurality of second electrodes to the second voltage in the transition period, And the difference between the first voltage and the second voltage is the sustain voltage. The method of claim 11, And the external image signal having the first vertical synchronization frequency is an NTSC signal, and the external image signal having the second vertical synchronization frequency is a PAL image signal. A plasma display panel including a plurality of electrodes, A control unit including a video signal processing unit detecting a vertical synchronization frequency of an external image signal received from the outside, and a mode determination unit determining a driving mode according to the vertical synchronization frequency of the external image signal; A driving unit configured to apply a driving voltage to the plasma display panel according to the driving control signal; The control unit, A first mode in which the image signal processor detects a first vertical synchronizing frequency and generates a control signal for driving one frame into a plurality of subfields in synchronization with the first vertical synchronizing frequency; A second mode for generating a control signal for driving in a transient period when the mode determining unit detects a change in the vertical synchronizing frequency; and The image signal processor detects a second vertical synchronization frequency and performs a third mode of generating a control signal for driving one frame into a plurality of subfields in synchronization with the second vertical synchronization frequency; , The driving unit, And a reset rising waveform gradually rising and a reset falling waveform gradually falling to the plurality of electrodes in the transient period. The method of claim 13, The control unit, When the mode determiner detects a change in the vertical synchronization frequency from the first vertical synchronization frequency to the second vertical frequency, the image signal processor determines whether the second vertical synchronization frequency is detected during the first period. And a fourth mode of generating a control signal for driving a frame into a plurality of subfields in synchronization with the first vertical synchronization frequency during a first period, and then performing the third mode. The method according to claim 13 or 14, And the reset rising waveform is a voltage waveform gradually rising from the sustain voltage to the first voltage, and the reset falling waveform is a voltage waveform gradually falling from the sustain voltage to the second voltage. The method of claim 15, The driving unit, And applying the reset rising waveform and the reset falling waveform to the plurality of electrodes in a second period including an end point of the transient period during the transient period. The method according to claim 13 or 14, The driving unit, And the reset rising waveform is a voltage waveform gradually rising from a first voltage lower than a sustain voltage to a second voltage, and the reset falling waveform is a voltage waveform gradually falling from the first voltage to a third voltage. The method of claim 17, The driving unit, And applying the reset rising waveform and the reset falling waveform to the plurality of electrodes in a second period including an end point of the transient period during the transient period. The method according to claim 13 or 14, The first vertical synchronizing frequency is 60 Hz, and the second vertical synchronizing frequency is 50 Hz.

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