KR100719578B1 - Method for driving plasma display panel - Google Patents

Abstract

An object of the present invention is to provide a method of driving a plasma display panel that is stable and uniform address discharge is performed according to the temperature of the panel.

In order to achieve the above object, according to the present invention, discharge cells are defined in an area where a plurality of electrodes intersect, a unit frame displaying an image is divided into a plurality of subfields, and each subfield initializes all of the discharge cells. A reset period, an address period for distinguishing a cell to be turned on and a cell not to be turned on, and a sustain period for performing sustain discharge according to a gray scale weight assigned to each subfield in a discharge cell selected as a cell to be turned on In the method of driving a plasma display panel divided into

In the reset period, a falling pulse is applied to the first electrode of the plurality of electrodes, a bias voltage is applied to the second electrode extending in parallel with the first electrode, and a falling pulse is applied to the first electrode. The potential level of the bias voltage applied to the second electrode is increased as the temperature of the panel increases, and lower as the temperature of the panel decreases.

Description

Method for driving plasma display panel {Method for driving plasma display panel}

1 is a timing diagram showing a conventional driving signal for driving a plasma display panel.

2 is a diagram illustrating an electrode arrangement of a plasma display panel to which the method of driving a plasma display panel of the present invention can be applied.

3 is a timing diagram briefly illustrating a method of driving an address display separation (ADS).

4 is a block diagram schematically illustrating a plasma display apparatus to which a method of driving a plasma display panel of the present invention can be applied.

5 is a timing diagram illustrating an example of a method of driving a plasma display panel.

Explanation of symbols on the main parts of the drawings

Y1, ..., Yn ... first electrodes or scan electrodes

X1, ..., Xn ... second electrodes or sustain electrodes

A1, ..., Am ... third electrodes or address electrodes

Vsch ... high level of injection pulse Vscl ... low level of injection pulse

Vs ... high level of holding pulse Vg ... low level of holding pulse

High level of Va ... display data signal

Vb1, Vb2, Vb3 ... Bias Voltages

1st, 2nd period of the application period of T1, T2 ... falling pulse

ΔV ... potential difference between the lowest level of the falling pulse and the low level of the scanning pulse applied in the first period

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of driving a plasma display panel, and more particularly, to a method of driving a plasma display panel to stably perform an address discharge according to a panel temperature.

Recently, a plasma display panel, which is drawing attention as a replacement of a conventional cathode ray tube display device, is discharged after a discharge gas is filled between two substrates on which a plurality of electrodes are formed. The phosphor formed in a predetermined pattern by the ultraviolet rays is excited to obtain a desired image.

1 is a timing diagram showing a conventional driving signal for driving a plasma display panel.

The unit frame for displaying an image is divided into a plurality of subfields, and each subfield is driven in time division by being divided into a reset period, an address period, and a sustain period.

In the drawing, during the reset period, the rising pulse and the falling pulse are applied to the scan electrodes, and the bias voltage is applied to the sustain electrodes when the falling pulse is applied to initialize the entire discharge cell. In the address period, scan pulses are sequentially applied to the scan electrodes, display data signals are applied to the address electrodes to perform address discharge, and in the sustain period, sustain pulses are alternately applied to the scan electrodes and sustain electrodes. Thus, the sustain discharge is performed in the discharge cells in which the address discharge is performed, that is, divided into the cells to be turned on.

As described above, according to the driving signal of the conventional plasma display panel, a constant driving signal is applied to each electrode.

On the other hand, the rising pulse in the reset period serves to accumulate negative wall charges around the scan electrodes, and the falling pulse serves to erase the accumulated negative wall charges. When the falling pulse is applied, the bias voltage serves to accumulate an appropriate amount of negative charges that are erased in the vicinity of the scan electrode. Since the scan electrode performs address discharge with the address electrode during the address period, it is important to control the wall charge by applying the falling pulse and the bias voltage in the reset period. In the related art, as shown in FIG. 1, the lowest level of the falling pulse is higher than the low level of the scanning pulse. Thus, when the lowest level of the falling pulse is applied higher than the low level of the scanning pulse, the amount of wall charges erased in the vicinity of the scanning electrode is not erased in an appropriate amount, so that the address discharge is not stable. That is, there is a possibility that the address discharge is performed with over discharge. In addition, the application of the falling pulse and the bias voltage for erasing the wall charge near the scanning electrode is applied with the same falling pulse and the bias voltage while ignoring the temperature characteristic of the panel. Thus, when the panel temperature is high, the address discharge is low discharged. When the temperature of the panel is low temperature, the address discharge is performed by overdischarge.

SUMMARY OF THE INVENTION The present invention has been made to solve various problems including the above problems, and an object thereof is to provide a method of driving a plasma display panel in which a stable and uniform address discharge is performed according to the panel temperature.

In order to achieve the above object, according to the present invention, discharge cells are defined in an area where a plurality of electrodes intersect, and a unit frame for displaying an image is divided into a plurality of subfields, and each subfield is divided into entire discharge cells. A sustain discharge is performed according to a reset period for initializing, an address period for distinguishing a cell to be turned on and a cell not to be turned on among all the discharge cells, and a gray scale weight assigned to each subfield in a discharge cell selected as a cell to be turned on. In the method of driving a plasma display panel divided into periods,

In the reset period, a falling pulse is applied to the first electrode of the plurality of electrodes, a bias voltage is applied to the second electrode extending in parallel with the first electrode, and a falling pulse is applied to the first electrode. While the potential level of the bias voltage applied to the second electrode is increased as the temperature of the panel is increased, and as the temperature of the panel is lower, the driving method of the plasma display panel is provided.

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According to another aspect of the present invention, the potential level of the bias voltage is divided into a plurality of temperature sections of the panel temperature, the higher the temperature in the temperature section, the higher the potential level of the bias voltage.

According to still another aspect of the present invention, in an address period, a scan pulse having a low level is sequentially applied while maintaining a high level to the first electrode, and a scan pulse is applied to a third electrode extending across the first electrode. In accordance with this, a display data signal having a high level is applied, and a variable bias voltage is applied to the second electrode.

According to this still further feature of the present invention, in the sustain period, sustain pulses having a high level and a low level are alternately applied to the first electrode and the second electrode.

According to another feature of the present invention, the application period of the falling pulse is divided into a first period of gradually falling and a second period of rapidly falling to maintain the first voltage.

According to this still further feature of the present invention, the low level of the scan pulse is equal to the first voltage.

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

2 is a diagram illustrating an electrode arrangement of a plasma display panel to which the method of driving a plasma display panel of the present invention can be applied.

The first electrodes (scan electrodes, Y1, ... Yn) and the second electrodes (hold electrodes, X1, ..., Xn) extend in parallel with each other, and the third electrodes (address electrodes, A1). Am extends in a direction intersecting the first electrodes (scanning electrodes, Y1, ... Yn) and the second electrodes (holding electrodes, X1, ..., Xn). Discharge cells are defined in the intersecting area.

2 illustrates an electrode arrangement of a plasma display panel having a three electrode structure, the method of driving the plasma display panel of the present invention may be applied to a plasma display panel having a two electrode structure in addition to the plasma display panel having a three electrode structure. The following description will be based on the three-electrode structure.

The structure of the plasma display panel will be briefly described with reference to FIG. 2. The plasma display panel includes a first substrate and a second substrate, and a plurality of electrodes intersecting with each other between the first substrate and the second substrate, and the crossing regions. And a partition wall forming a discharge space together with the first substrate and the second substrate, a phosphor layer disposed in the discharge cell, and a discharge gas so as to define the discharge cells.

3 is a timing diagram briefly illustrating a method of driving an address display separation (ADS).

Referring to this, the unit frame for displaying an image is divided into a plurality of subfields, and each subfield is divided into a reset period, an address period, and a sustain period. The reset period is a period for initializing all the discharge cells, and the address period is a period for distinguishing the discharge cells that should be turned on and the discharge cells that should not be turned on among all the discharge cells, and the sustain period is a discharge cell selected as the discharge cells to be turned on. A sustain discharge period is performed according to the gray scale weights allocated to each subfield. The plasma display panel is driven by a time division driving method for applying a driving signal in accordance with the reset, address, and sustain periods for each subfield as described above.

In the drawing, the unit frame is divided into eight subfields SF1 to SF8, and each subfield is divided into a reset period (not shown), an address period A1 to A8, and a sustain period S1 to S8. The gray scale weight is allocated from the first subfield to the eighth subfield as 1T, 2T, ... 128T, but this is only an example and the present invention is not limited thereto. That is, the number of subfields of a unit frame may be less or more than eight, and the allocation of gray scale weights for each subfield may be changed according to a design specification, unlike illustrated.

4 is a block diagram schematically illustrating a plasma display apparatus to which a method of driving a plasma display panel of the present invention can be applied.

Referring to the drawings, the plasma display apparatus of FIG. 4 once includes an image processor 300, a logic controller 302, a Y driver 304, an address driver 306, an X driver 308, and a plasma display panel ( 1) is provided.

The image processor 300 receives an external video signal such as a PC signal, a DVD signal, a video signal, or a TV signal from the outside, converts an analog signal into a digital signal, and processes the digital signal into an internal video signal. The internal video signals are 8-bit red (R), green (G), and blue (B) image data, clock signals, and vertical and horizontal sync signals, respectively.

The logic controller 302 receives the internal image signal from the image processor 300 and undergoes a gamma correction and an automatic power control (APC) step, respectively, to drive the Y drive control signal SY and the A drive control signal SA. And an X drive control signal SX.

The Y driver 304 receives the Y drive control signal SY from the logic controller 302 and applies a drive signal to the first electrode (scanning electrode), and the address driver 306 receives the logic signal from the logic controller 302. The driving signal is applied to the third electrode (address electrode) by receiving the address driving control signal SA, and the X driving unit 308 receives the X driving control signal SX from the logic controller 302 to the second electrode (holding electrode). Is applied to the drive signal. Hereinafter, the first electrode will also be described as a scan electrode, the second electrode will be described as a scan electrode, and the third electrode will be described as an address electrode.

The Y driver 304 applies a reset pulse to the scan electrodes in the reset period. The reset pulse may be composed of only the falling pulse, and may be composed of the rising pulse and the falling pulse. The discharge cells are initialized while the wall charges are accumulated or erased in the discharge cells by the reset pulse. In addition, while maintaining the high level in the address period, the scan pulses having the low level are sequentially applied, and the sustain pulses having the high level and the low level are applied in the sustain period.

The address driver 306 applies a display data signal having a high level in accordance with the scan pulse in the address period. The address discharge is performed in the address period by the display data signal and the scanning pulse.

The X driver 308 applies a bias voltage from when the falling pulse is applied among the reset pulses to the end of the address period. In connection with the present invention, the voltage level of the bias voltage is varied according to the temperature of the panel. Meanwhile, in the sustain period, a sustain pulse having a high level and a low level is applied, but alternately with a sustain pulse output from the Y driver.

5 is a timing diagram illustrating an example of a method of driving a plasma display panel, which is a driving signal for solving the problem of the driving signal of FIG. 1.

As shown in Fig. 1, the lowest level Vnf of the falling pulse applied to the scan electrodes Y1, ..., Yn in the reset period is applied to the scan electrodes Y1, ..., Yn in the address period. In order to solve the problem that the address discharge is over-discharged in the address period by being applied higher than the low level Vscl of the pulse, the driving signal of FIG. 5 has the lowest level of the falling pulse equal to the low level Vscl of the scanning pulse. Do it. In addition, in consideration of the temperature characteristics of the panel, the voltage level of the bias voltage is varied when the falling pulse is applied. That is, if the panel temperature is high, the voltage level of the bias voltage is increased so that the address discharge is not performed with low discharge, and if the panel temperature is low, the voltage level of the bias voltage is lowered so that the address discharge is not performed with over discharge. .

Referring to the drawings, rising pulses and falling pulses are applied to the scan electrodes Y1,..., And Yn in the reset period PR1 of the first subfield. The rising pulse rises from the sustain discharge voltage, i.e., the high level Vs of the sustain pulse, rises to the rise maximum voltage Vs + Vset, and the fall pulse falls from the sustain discharge voltage Vs. The application of the rising pulse begins to accumulate negative wall charges near the scan electrodes, and the application of the falling pulse begins to erase the negative wall charges accumulated near the scan electrodes. In particular, since the falling pulse erases unnecessary wall charges so that the address discharge is stably performed between the scan electrode and the address electrode in the address period, that is, an appropriate amount of wall charges is accumulated, the lowest level of the falling pulse is important. . On the other hand, while applying a bias voltage from the falling pulse is applied, the voltage level of the bias voltage is varied in consideration of the temperature of the panel. It is preferable that the voltage level of the bias voltage is continuously increased as the temperature of the panel increases. In addition, in the case where the panel temperature is divided into a plurality of temperature sections, the bias voltage may be constant in the same temperature section, but the voltage level of the bias voltage may be varied for each temperature section. As shown in the drawing, if the temperature section of the panel is divided into three sections, it may be divided into a first temperature section, a second temperature section, and a third temperature section. If the temperature of the first temperature section is the lowest section, and the temperature of the third temperature section is the highest temperature section, when the panel temperature belongs to the first temperature section, the voltage level of the bias voltage is the lowest level. If the temperature of the panel belongs to the second temperature section, the voltage level of the bias voltage is set to Vb2, which is an intermediate level. If the temperature of the panel belongs to the third temperature section, the voltage level of the bias voltage is the highest. The level is set to Vb3. Conventionally, the address discharge was performed with low discharge when the panel temperature was high. However, in the present invention, the voltage level of the bias voltage is increased, so that the negative wall charge is accumulated more near the scan electrode when the falling pulse is applied. Allow address discharge to be stably performed. In addition, although the address discharge is conventionally performed as an overdischarge when the panel temperature is low, in the present invention, the voltage level of the bias voltage is lowered so that the negative wall charges are accumulated in the vicinity of the scan electrode when the falling pulse is applied. The address discharge is stably performed.

On the other hand, the application period of the falling pulse can be divided into a first period (T1) gradually falling as shown in the figure, and a second period (T2) that is rapidly falling to maintain the first voltage (Vnf). In the driving signal of FIG. 1, the lowest level Vnf of the falling pulse is higher than the low level Vscl of the scanning pulse, and wall charges are not properly erased in the vicinity of the scanning electrode in the reset period, so that the address discharge is over discharged. There was a tendency. In order to solve this problem, the driving signal of FIG. 5 divides the application period of the falling pulse into the first period T1 and the second period T2, and in the first period T1, the falling pulse is gradually lowered to fine-wall the charges. In the second period T2, the voltage is rapidly lowered to maintain the first voltage, so that only a proper amount of wall charge remains. The first voltage is preferably equal to the low level Vscl of the scan pulse applied to the scan electrode in the address period. At this time, the difference between the lowest level of the falling pulse in the first period and the low level Vscl of the scanning pulse is ΔV. By the drive signal of Fig. 5, only a proper amount of wall charges in the vicinity of the scan electrode remains, so that the address discharge in the address period can be performed uniformly and stably.

In the address period PA1 of the first subfield, the scan electrodes Y1,..., And Yn maintain the high level Vsch and sequentially apply the scan pulses having the low level Vscl. A display data signal having a high level Va is applied to (A1, ..., Am) in accordance with the scan pulse, and a reset period is applied to the sustain electrodes (X1, ..., Xn) according to the temperature of the panel. One of the applied bias voltages Vb1, Vb2, and Vb3 is applied when the falling pulse is applied. The address discharge is performed in the discharge cells to be turned on, so that positive wall charges are accumulated near the scan electrodes in the discharge cells where the address discharge has been performed, and negative wall charges are accumulated near the sustain electrodes.

In the sustain period PS1 of the first subfield, the scan electrodes Y1, ..., Yn and the sustain electrodes X1, ..., Xn have a high level Vs and a low level Vg. Alternating holding pulses are applied alternately. The sustain pulse is applied such that sustain discharge is performed by the gray scale weight of the first subfield SF1.

The reset period, the address period, and the sustain period after the second subfield may be applied with the same driving signals as the reset period, the address period, and the sustain period of the first subfield described above. However, in the sustain period, the length of the sustain pulse applied depends on the gray scale weight.

On the other hand, the driving signal of Fig. 5 applies only the falling pulse in the reset period PR2 of the second subfield, and adopts the selective reset driving method.

In the selective reset driving method, first, a rising pulse and a falling pulse are applied in the reset period PR2 of the first subfield to accumulate negative wall charges due to the application of the rising pulse near the scan electrode in the discharge cell. All the discharge cells are initialized by erasing the negative wall charges accumulated by the application of the pulse. Next, during the reset periods PR2 to PR8 after the second subfield, only the falling pulse is applied, and in the discharge cell in which the sustain discharge has been performed, the wall charge accumulated by the sustain discharge is erased by applying the falling pulse, thereby discharging the discharge cell. In the discharge cell in which the wall charge state of? Is initialized, but the sustain discharge is not performed, the initialization state without accumulated wall charge is kept, so that the wall charge is not erased despite the application of the falling pulse. The wall charges are erased only in the discharge cells in which the sustain discharge has been performed by the selective driving method. However, at the end of the reset period, the wall charges of all the discharge cells are maintained in the initialized state. Such a selective reset method can shorten the reset period by applying only the falling pulse in the reset period after the second subfield, and can assign the shortened period to the address period or the sustain period, in particular, high-quality plasma display. It is suitable for driving the panel.

Meanwhile, in the reset period PR2 of the second subfield, the falling pulse is applied to the scan electrodes Y1,..., And Yn, and the applying period of the falling pulse is the same as in the reset period PR1 of the first subfield. The first period T1 gradually descends, and the second period T2 rapidly descends to maintain the first voltage. When the falling pulse is applied, one of the voltage levels Vb1, Vb2, and Vb3 of the bias voltage is applied to the sustain electrodes X1, ..., Xn according to the temperature of the panel. In other words, the higher the temperature of the panel, the higher the voltage level of the bias voltage.

The driving signal applied to the address period PA2 and the sustain period PS2 of the second subfield is the same as the driving signal applied to the address period PA1 and the sustain period PS1 of the first subfield. However, the length of the sustain pulse applied to the sustain period PS2 of the second subfield is determined by the gray scale weight of the second subfield SF2.

According to the present invention as described above, the following effects can be obtained.

First, since the voltage level of the bias voltage applied from the application of the falling pulse in the reset period is varied according to the temperature of the panel, only an appropriate amount of negative wall charges remain near the scan electrodes at the end of the reset period, so that the address discharge in the address period Is uniform and stable.

Second, by dividing the application period of the falling pulse into a first period of gradually falling and a second period of rapidly falling to maintain the first voltage (Vscl), the wall charge near the scanning electrode is erased in an appropriate amount, so that the address discharge This is also done stably.

Third, by adopting the selective reset driving method, the reset period is shortened, and can be further allocated to the address period or the sustain period by the shortened period, thereby enabling the driving of the plasma display panel of high quality.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (7)

Discharge cells are defined in an area where a plurality of electrodes cross each other, and a unit frame displaying an image is divided into a plurality of subfields, and each subfield must be turned on during a reset period for initializing all discharge cells. A driving method of a plasma display panel divided into an address period for distinguishing a cell to be turned on and a cell not to be turned on, and a sustain period for performing sustain discharge according to a gray scale weight assigned to each subfield in a discharge cell selected as a cell to be turned on, In the reset period, a falling pulse is applied to a first electrode of the plurality of electrodes, a bias voltage is applied to the second electrode extending in parallel with the first electrode from the time of applying the falling pulse, and to the first electrode. The potential level of the bias voltage applied to the second electrode while the falling pulse is applied is higher as the temperature of the panel is increased and lower as the temperature of the panel is lower. . delete The method of claim 1, The potential level of the bias voltage is divided into a plurality of temperature sections of the panel temperature, the higher the temperature in the temperature section, the higher the potential level of the bias voltage, characterized in that the driving method of the plasma display panel. The method of claim 1, In the address period, a display pulse having a high level while maintaining a high level to the first electrode and sequentially applying a scanning pulse having a low level, and having a high level in accordance with the scanning pulse to a third electrode extending across the first electrode. And applying a data signal and applying the variable bias voltage to the second electrode. The method of claim 1, And in the sustain period, sustain pulses alternately having high and low levels are alternately applied to the first electrode and the second electrode. The method of claim 4, wherein And a period in which the falling pulse is applied is divided into a first period of gradually falling and a second period of rapidly falling to maintain the first voltage. The method of claim 6, And a low level of the scan pulse is the same as that of the first voltage.

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