KR100649534B1 - Plasma display device and driving method thereof - Google Patents

Abstract

A plasma display device and a driving method thereof are provided to correctly execute addressing of a second group by adjusting the width of sustain discharge pulse during a sustain period according to the temperature. In a method for driving a plasma display device having a plasma display panel comprising plural first and second electrodes and plural third electrodes formed across the first and second electrodes, the first electrodes are divided into plural groups(G1,G2,G3,G4) including first and second groups, and a subfield includes plural address and sustain periods corresponding to each group. In at least one subfield, the driving method comprises the steps of selecting cells to be displayed, from cells of the first and second groups during each address period of the first and second groups and executing sustain discharge during a first sustain period(S11,S21,S31,S41) between the address periods of the first and second groups. The first pulse width of sustain discharge pulse applied to the first and second electrodes during the first sustain period is determined according to the temperature of the plasma display panel and the peripheral temperature.

Description

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

1 is a diagram illustrating a gray scale expression 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.

3 is a diagram illustrating an operation of the controller illustrated in FIG. 2.

FIG. 4 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.

5 is a diagram illustrating an example in which scan electrodes of a plasma display panel according to an exemplary embodiment are divided into four groups.

FIG. 6 is a driving waveform diagram of a plasma display device in which the driving method described with reference to FIG. 5 is applied to two scan electrode groups YG1 and YG2 and a sustain electrode X. FIG.

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

A plasma display device is a flat display device that displays characters or images by using plasma generated by gas discharge. The display panel may have tens to millions or more of discharge cells (hereinafter, referred to as "cells") depending on its size. Arranged in matrix form.

In general, the plasma display device divides one frame into a plurality of subfields having respective weights, and time-division controls them to implement gray scale. 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 each cell to smoothly perform an address operation on the cell, and the address period is a period for selecting a cell to be turned on from a plurality of cells through address discharge. That is, in the address period, scan pulses are sequentially applied to the plurality of scan electrodes, and address pulses are applied to the address electrodes. At this time, address discharge occurs in a cell to which a scan pulse and an address pulse are simultaneously applied. In the sustain period, sustain discharge pulses having a high level voltage and a low level voltage are alternately applied to the scan electrode and the sustain electrode in opposite phases to generate sustain discharge in a cell to be turned on.

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, the sustain discharge operation on the scan electrode line is performed only after the address operation of the last scan electrode line is completed after the air dress operation is performed on one scan electrode line. 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 the time gap between the address operation and the sustain discharge operation and stably performing the sustain discharge operation.

According to an aspect of the present invention for achieving the above object, a plurality of first electrodes and a plurality of second electrodes and a plurality of agents formed in a direction crossing the plurality of first electrodes and the plurality of second electrodes A method of driving a plasma display device including a plasma panel including three electrodes is provided. The driving method includes at least one of the plurality of first electrodes divided into a plurality of groups including a first group and a second group, the plurality of first electrodes including a plurality of address periods and a plurality of sustain periods respectively corresponding to the respective groups. Selecting cells to be displayed from among the cells of the first and second groups, respectively, in an address period of each of the first and second groups; And generating sustain discharge in a first sustain period that is located between an address period of the first group and an address period of the second group of the plurality of sustain periods. In this case, the magnitude of the first pulse width of the sustain discharge pulses applied to the plurality of first and second electrodes in the first sustain period is determined according to the temperature of the plasma display panel and the temperature of the caution. Is determined.

According to another feature of the present invention, a plasma display device is provided. The plasma display device includes a plasma display panel including a plurality of first electrodes and a plurality of second electrodes; A temperature sensing unit sensing a temperature of the plasma display panel; And a controller configured to generate a control signal for driving the plasma display panel according to the sensed temperature. In this case, the controller may be configured to divide the plurality of first electrodes into a plurality of groups including a first group and a second group, and to include at least one of a plurality of address periods and a plurality of sustain periods, respectively. Selecting cells to be displayed from the cells of the first and second groups, respectively, in one subfield in an address period of each of the first and second groups; And applying a sustain discharge pulse having a first pulse width in a first sustain period that is located between an address period of the first group and an address period of the second group among the plurality of sustain periods. At this time, the magnitude of the first pulse width is determined according to the sensed temperature.

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.

In addition, the wall charge referred to in the present invention refers to a charge formed in the wall (eg, a dielectric layer) of the discharge cell close to each electrode and accumulated in the electrode. Such wall charges are not actually in contact with the electrodes themselves, but here wall charges are described as "formed", "accumulated" or "stacked" on the electrodes. In addition, wall voltage refers to the potential difference formed in the wall of a discharge cell by wall charge.

A method of driving a plasma display device 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 scan electrode driver 400, a sustain electrode driver 500, and the like. It includes a temperature sensor 600.

The plasma display panel 100 includes a plurality of address electrodes A1-Am extending in the column direction, a plurality of sustain electrodes X1-Xn extending in the row direction, and a plurality of scan electrodes Y1-Yn. 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. At this time, the control unit 200 according to the temperature of the plasma display panel 100 received from the temperature sensor 600 or the ambient temperature of the plasma display panel sustain discharge pulse width in the sustain period located between the plurality of address periods. Outputs a control signal to adjust.

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 scan electrode driver 400 receives a scan electrode driving control signal from the controller 200 and applies a driving voltage to the scan electrode. The sustain electrode driver 500 receives the sustain electrode driving control signal from the controller 200 and applies a driving voltage to the sustain electrode.

The temperature detector 600 detects the temperature of the plasma display panel 100 or the temperature around the plasma display panel and transmits the detected temperature to the controller 200. Hereinafter, the temperature sensing unit 600 will be described as sensing the temperature of the plasma display panel for convenience. However, it is natural that the temperature sensing unit 600 can measure the temperature of not only the plasma display panel but also other parts.

Next, an operation of the controller 200 in the plasma display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 3.

3 is a diagram illustrating an operation of the controller illustrated in FIG. 2.

As shown in FIG. 3, the controller 200 receives the temperature of the plasma display panel 100 detected by the temperature sensor 600 and compares the temperature with a predetermined temperature (S410-S420).

At this time, when the detected temperature is higher than or equal to the predetermined temperature, the control unit 200 outputs a control signal for widening the sustain discharge pulse width in the sustain period located between the plurality of address periods than the pulse width Ts in the common sustain period. (S430).

On the other hand, when the sensed temperature is less than the predetermined temperature, the control unit 200 applies a sustain discharge pulse having the same pulse width as the pulse width Ts in the common sustain period in the sustain period located between the plurality of address periods. The control signal is output (S440).

In this way, the control signal output from the control unit 200 is input to the scan electrode driver 400 and the sustain electrode driver 500, and the scan electrode Y and the sustain electrode X in the sustain period which are located between the plurality of address periods. Wall voltage is controlled between (S450).

Here, the predetermined temperature may be obtained through an experimental method as the temperature of the point where the low discharge occurs in the address period, and the detailed description thereof will be omitted since it will be readily understood by those skilled in the art. Generally, the predetermined temperature is measured at about 60 ° C.

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. 4 to 6.

FIG. 4 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. 4, the gray level is expressed 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 neighboring lines may not be collected, but scan electrode lines spaced apart from each other may be collected in 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.

5 is a diagram illustrating an example in which scan electrodes of a plasma display panel according to an exemplary embodiment 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 for the cells of the first group G1, at least two sustain pulses are 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.

FIG. 5 shows an example in which all of the cells in the group in which the address period was previously performed are performed while the sustain period is performed in 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 for the 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 the sustain discharge operation for one group are completed, the address operation and the 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.

FIG. 6 is a driving waveform diagram of a plasma display device in which the driving method described with reference to FIG. 5 is applied to two scan electrode groups YG1 and YG2 and a sustain electrode X. FIG.

In the reset period R, a reset waveform is applied to the scan electrode lines of the first and second groups YG1 and YG2 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, first, the address period AG1 of the first group YG1 is performed, and the sustain period S11 of the first group YG1 is performed. After the sustain period S11 of the first group YG1 is completed, the address period AG2 of the second group YG2 is performed. Then, the second sustain period S12 of the first group YG1 and the first sustain period S21 of the second group YG2 are performed together.

Subsequently, the address period AG1 of the address / sustain mixing period T1 is performed on the scan electrodes of the first group YG1. In the address period AG1, a scan pulse having a VscL voltage is sequentially applied to the scan electrodes of the first group YG1 while the scan electrodes of the second group YG2 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 S11 of the address / sustain mixing period T1, sustain discharge pulses having a Ts pulse width are alternately applied to the scan electrodes YG1 and YG2 and the sustain electrode X. In FIG. 5, one sustain discharge pulse is applied to the scan electrodes YG1 and YG2 and the sustain electrodes XG1 and XG2, 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 YG1 and YG2 and 0 V is applied to the sustain electrode X, and a wall is formed between the scan electrode YG1 and the sustain electrode X by address discharge in the address period AG1. In the cell in which the voltage is formed, sustain discharge occurs due to the wall voltage and the voltage difference Vs between the scan electrode YG1 and the sustain electrode X to form a wall voltage of opposite polarity between the scan electrode and the sustain electrode.

On the other hand, while the sustain discharge pulse is applied to the scan electrodes of the second group YG2 in the sustain period S11 of the address / sustain mixing period T1, a wall voltage is formed between the scan electrode YG2 and the sustain electrode X. There is no maintenance discharge. As such, when the address period AG1 and the sustain period S11 of the address / sustain mixing period T1 are completed for the scan electrodes of the first group YG1, the addresses of the scan electrodes of the second group YG2 are subsequently added. The address period AG2 of the / hold mixing period T1 is performed.

With respect to the scan electrodes of the second group YG2, in the address period AG2 of the address / sustain mixing period T1, the scan electrodes YG2 are sequentially arranged while the other scan electrode Y is maintained 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 S11 and a part of the address period AG2 overlap each other, the two periods S1 and AG2 may be separated.

In the sustain periods S21 and S12 of the address / sustain mixing period T1, a sustain discharge pulse having a pulse width Ts of the scan electrodes YG1 and YG2 and the sustain electrode X, and alternately having a Vs voltage and a 0V voltage. Is applied. Then, sustain discharge occurs in a cell in which the wall voltage is formed in the address period AG2 among the cells of the second group YG2 and in a cell in which the wall voltage is formed in the address period AG1 among the cells of the first group YG1. That is, the sustain period S21 of the address / sustain mixing period T1 of the second group YG2 and the second sustain period S12 of the address / sustain mixing period T1 of the first group YG2 are performed simultaneously. do.

Then, in the common sustain period T2, sustain discharge pulses having a pulse width of Ts are applied to the first and second group scan electrodes YG1 and YG2 and the sustain electrode X so that the two groups YG1 and YG2 are applied. Maintenance discharge is commonly performed.

Then, in the luminance correction period T3, an additional holding period is given for the cells of the second group YG2 in order to make the cells of the first group YG1 and the second group YG2 have the same luminance. That is, in the luminance correction period T3, the discharge does not occur in the cells of the first group YG1, and the discharge occurs only for the cells of the second group YG2. To this end, when the sustain discharge pulse of the Vs voltage is applied to the sustain electrode X, the Vs voltage is applied to the first group scan electrode YG1 and the ground voltage (0V) is applied to the second group scan electrode YG2. Then, since the voltage difference between the scan electrode YG1 and the sustain electrode X is 0 V in the first group YG1, no discharge occurs, and sustain discharge occurs only in the cells of the second group. Then, 0 V is applied to the sustain electrode X, and a Vs voltage is applied to the scan electrodes of the first group YG1 and the second group YG2. Then, since there is no previous sustain discharge in the cells of the first group YG1, 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 second group YG2. In this way, the number of sustain discharges in the first group YG1 is limited by the number of sustain discharges in the sustain period S11 of the address / sustain mixture period T1, so that the first group YG1 and the second group YG2 Are made equal.

Therefore, in the subfield of FIG. 6, the first group YG1 and the second group YG2 are discharged five times in the same manner.

On the other hand, when the plasma display panel 100 or the temperature around it is high, the formation conditions of magnesium oxide (MgO) covering the scan electrode Y and sustain electrode X are sensitively changed depending on the plasma display panel temperature. The wall charges accumulated on the scan electrodes YG1 and YG2 and the sustain electrode X are lost to the space between the scan electrodes YG1 and YG2 and the sustain electrode X, and thus sustain discharge cannot be properly performed.

Particularly, when the scan pulse is applied in the address / sustain mixing period T1, in the case of the cell corresponding to the scan electrode to which the scan pulse is applied in the second half, the scan pulse is applied in a state where the wall charges are largely lost. The addressing operation of the group G2 is difficult to be performed properly.

Therefore, as shown in FIG. 3, when the sensed temperature is higher than the predetermined temperature, the wall charges lost between the scan electrodes YG1 and YG2 and the sustain electrode X in the address / sustain mixing period T1. In order to compensate the amount, in the first holding period S11 of the first group G1, the holding periods S21 and S12 and the common holding period T2 of the address / holding mixing period T1 are applied. A sustain discharge pulse having Ts1 wider than the discharge pulse width Ts is applied. That is, the width of the sustain discharge pulses applied to the scan electrodes YG1 and YG2 and the sustain electrode X in the first sustain period S11 of the first group G1 is increased to compensate for the amount of wall charges lost. Prevents low discharge at high temperatures.

On the other hand, as shown in FIG. 3, when the sensed temperature is lower than the predetermined temperature, in the first holding period S11 of the first group G1, the holding period S21 of the address / holding mixing period T1, A sustain discharge pulse having a width equal to the sustain discharge pulse width Ts applied in S12) and the common sustain period T2 is applied.

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, in the plasma display device which drives the scan electrodes in a plurality of groups, the width of the sustain discharge pulse in the sustain period located between the plurality of address periods is adjusted according to the temperature. The addressing of the two groups is performed properly, and the sustain discharge occurs stably in the sustain period of the address / sustain mixture period.

Claims (8)

And a plasma display panel including a plurality of first electrodes, a plurality of second electrodes, and a plurality of third electrodes formed in a direction crossing the plurality of first electrodes and the plurality of second electrodes. In the driving method,  The plurality of first electrodes may be divided into a plurality of groups including a first group and a second group, and in at least one subfield including a plurality of address periods and a plurality of sustain periods, respectively, corresponding to the groups. Selecting cells to be displayed from among cells of the first and second groups, respectively, in an address period of each of the first and second groups; And Generating sustain discharge in a first sustain period that is located between an address period of the first group and an address period of the second group of the plurality of sustain periods, The magnitude of the first pulse width of the sustain discharge pulses applied to the plurality of first and second electrodes in the first sustain period is determined according to the temperature of the plasma display panel and the temperature of the caution. A method of driving a plasma display device. The method of claim 1, Applying a sustain discharge pulse having a second pulse width to the plurality of first electrodes and the plurality of second electrodes in a second sustain period positioned after the address period of the second group of the plurality of sustain periods; The driving method of the plasma display device further comprising. The method of claim 2, In the first holding period, And the first pulse width is greater than the second pulse width when the sensed temperature is higher than a reference temperature. The method of claim 2, In the first holding period, And the first pulse width is equal to the second pulse width when the sensed temperature is lower than a reference temperature. A plasma display panel including a plurality of first electrodes and a plurality of second electrodes; A temperature sensing unit sensing a temperature of the plasma display panel; And And a controller configured to generate a control signal for driving the plasma display panel according to the sensed temperature. The control unit, The plurality of first electrodes may be divided into a plurality of groups including a first group and a second group, and in at least one subfield including a plurality of address periods and a plurality of sustain periods, respectively. , Selecting cells to be displayed from among cells of the first and second groups, respectively, in an address period of each of the first and second groups; And Applying a sustain discharge pulse having a first pulse width in a first sustain period that is located between an address period of the first group and an address period of the second group of the plurality of sustain periods, And the magnitude of the first pulse width is determined according to the sensed temperature. The method of claim 5, Applying a sustain discharge pulse having a second pulse width to the plurality of first electrodes and the plurality of second electrodes in a second sustain period positioned after the address period of the second group of the plurality of sustain periods; Plasma display device further comprising. The method of claim 6, The control unit, And when the sensed temperature is higher than a reference temperature, controlling the first pulse width to be greater than the second pulse width in the first sustain period. The method of claim 6, And when the sensed temperature is lower than a reference temperature, controlling the first pulse width to have the same magnitude as the second pulse width in the first sustain period.

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