KR100796653B1 - Plasma display device and driving method thereof - Google Patents

Abstract

In the plasma display device, the voltage of the first electrode is gradually decreased from the first voltage to the second voltage between the reset period and the address period to prevent the cells that will not be turned on when the strong discharge occurs due to an unstable reset operation in the reset period. Doing. In this case, when the temperature of the plasma display panel is high, the first voltage is set lower than the first voltage when the temperature of the plasma display panel is low. In this case, strong discharge can be prevented when the first voltage is applied to the first electrode at a high temperature at which the discharge start voltage becomes low due to the characteristics of the plasma display panel.

PDP, electrode, mis-discharge, elimination, temperature

Description

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

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

2 illustrates a driving waveform of the plasma display device according to the first embodiment of the present invention.

3A is a diagram showing the wall charge state after the falling period of the reset period in accordance with the normal reset operation.

3B is a diagram showing the wall charge state after the falling period of the reset period due to the strong discharge in the falling period.

4 is a diagram illustrating an operation of the controller illustrated in FIG. 1.

5 illustrates a driving waveform of the plasma display device according to the second exemplary 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 display device using a plasma display panel (PDP) that displays characters or images using plasma generated by gas discharge. In the plasma display panel, dozens to millions or more pixels (discharge cells) are arranged in a matrix form according to their size.

The display panel of the plasma display device is driven by dividing one frame into a plurality of subfields having respective weights. Each subfield includes a reset period, an address period, and a sustain period.

The reset period is a period in which the state of the discharge cells is initialized to stably perform the address discharge, and the address period is a period in which cells to be turned on and cells not to be turned on are selected from among the plurality of discharge cells. The sustain period is a period in which sustain discharge is performed for the cells to be turned on to actually display an image.

In particular, after the voltage of the scan electrode Y is gradually increased in the rising period of the reset period, the voltage of the scanning electrode Y is gradually decreased in the falling period of the reset period, thereby causing the scan electrode Y and the sustain electrode X. ) A weak discharge (hereinafter referred to as "weak discharge") is generated between the electrodes and between the scan electrode Y and the address electrode A to form wall charges for stably performing the next address discharge. However, unstable discharge may occur due to an unstable reset operation. In the unstable discharge, when a strong discharge occurs in the rising period of the reset period and a discharge occurs due to self-erasing during the voltage drop of the scan electrode Y, a strong discharge occurs in the rising period and the falling period. In some cases, strong discharge occurs during the descent. In this case, in the first case, the reset function is performed according to the self-erasing. In the second and third cases, a positive wall charge is formed on the scan electrode Y due to the strong discharge in the falling period, and the sustain electrode X Negative wall charges are formed. At this time, if the wall voltage formed by the wall charges formed in the scan electrode Y and the sustain electrode X satisfies Equation 1, sustain discharge may occur in the sustain period even without the address discharge in the address period.

Here, Vwxy1 is a wall voltage formed between the scan electrode Y and the sustain electrode X due to the strong discharge in the falling period, and Vs is sustained with the scan electrode Y by the sustain discharge pulse applied in the sustain period. It is the voltage difference formed between the electrodes X, and Vf is the discharge start voltage between the scan electrode Y and the sustain electrode X.

As such, when strong discharge occurs due to an unstable reset operation in the falling period of the reset period, there is a problem in that false discharge occurs due to the strong discharge.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a plasma display device and a driving method thereof, which can prevent mis-discharge caused by an unstable reset operation. Another object of the present invention is to provide a plasma display device and a method of driving the same, which can prevent a strong discharge that may occur due to the characteristics of a plasma display panel whose discharge start voltage varies depending on temperature.

According to an aspect of the present invention, each of the plurality of first electrodes and the plurality of second electrodes includes a plurality of first electrodes and a plurality of second electrodes performing a display operation together with the plurality of first electrodes. In a plasma display device in which a plurality of discharge cells are formed at intersections, a method of driving one frame divided into a plurality of subfields is provided. The driving method includes sensing a temperature of the plasma display device, initializing the plurality of discharge cells in a reset period, assisting the reset period, and converting voltages of the plurality of first electrodes from a first voltage to a second voltage. Gradually decreasing the voltage, and differently setting the first voltages applied to the plurality of first electrodes according to temperatures of the plasma display device.

According to another aspect of the present invention, a plasma display device is provided. The plasma display device includes a plurality of first electrodes and a plurality of second electrodes that perform a display operation together with the plurality of first electrodes, and each cross point of the plurality of first electrodes and the plurality of second electrodes is provided. A plasma display panel in which a plurality of discharge cells are formed, a driver for gradually decreasing a voltage of the first electrode from a first voltage to a second voltage between a reset period and an address period, and a temperature sensing sensing a temperature of the plasma display panel And a controller configured to set the first voltage to be lower than the first voltage when the temperature of the plasma display panel is higher than the reference temperature when the temperature of the plasma display panel is lower than or equal to the reference temperature.

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. When a part is connected to another part, this includes not only a directly connected part but also a case where another part is connected in between.

In the present invention, the wall charge refers to a charge formed close to each electrode on the wall of the cell (eg, the dielectric layer). And the wall charge is not actually in contact with the electrode itself, but is described here as "formed", "accumulated" or "stacked" on the electrode. In addition, the wall voltage refers to the potential difference formed in the wall of the cell by the wall charge.

Now, a plasma display device and a driving method thereof according to an exemplary embodiment of the present invention will be described in detail.

First, a plasma display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 1.

1 is a diagram illustrating 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 sustain electrode driver 400, and a scan electrode driver 500. And a temperature sensing unit 600.

The plasma display panel 100 includes a plurality of address electrodes (hereinafter referred to as "A electrodes") A1 to Am extending in the column direction, and a plurality of sustain electrodes extending in pairs with each other in the row direction (hereinafter, " X electrodes "(X1 to Xn) and scan electrodes (hereinafter referred to as" Y electrodes ") (Y1 to Yn). In general, the X electrodes X1 to Xn are formed corresponding to the respective Y electrodes Y1 to Yn, and the display for displaying images in the sustain period between the X electrodes X1 to Xn and the Y electrodes Y1 to Yn. Perform the action. The Y electrodes Y1 to Yn and the X electrodes X1 to Xn are arranged to be orthogonal to the A electrodes A1 to Am. At this time, the discharge space at the intersection of the A electrodes A1 to Am and the X and Y electrodes X1 to Xn and Y1 to Yn forms a cell. The structure of the plasma display panel 100 is an example, and a panel having another structure to which the driving waveform described below may be applied may also be applied to the present invention.

The controller 200 receives an image signal from the outside and outputs an A electrode driving control signal, an X electrode driving control signal, and a Y electrode driving control signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield is composed of a reset period, an address period, and a sustain period.

The address electrode driver 300 receives an A electrode driving control signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each A electrode.

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

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

The temperature detector 600 detects the temperature of the plasma display panel 100 and transmits the temperature to the controller 200.

Next, a driving waveform of the plasma display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 2 to 3B. In the following description, only driving waveforms applied to the Y electrode, the X electrode, and the A electrode forming one cell will be described.

2 illustrates a driving waveform of a plasma display device according to an exemplary embodiment of the present invention. FIG. 3A is a diagram showing the wall charge state after the end of the fall period in the normal reset period, and FIG. 3B is a diagram showing the wall charge state due to the strong discharge in the fall period.

As shown in FIG. 2, each subfield of the plasma display device according to an exemplary embodiment includes a reset period, an error discharge erase period, an address period, and a sustain period.

In the rising period of the reset period, the voltage of the Y electrode is gradually increased from the Vs voltage to the Vset voltage while the X electrode is maintained at the reference voltage (0 V in FIG. 2). In FIG. 2, the voltage of the Y electrode is shown to increase in the form of a lamp. Then, a weak discharge occurs between the Y electrode and the X electrode and between the Y electrode and the A electrode while the voltage of the Y electrode is increased, so that a negative wall charge is formed at the Y electrode and a positive wall at the X and A electrodes. An electric charge is formed. When the voltage of the electrode gradually changes as shown in FIG. 2, a weak discharge occurs in the cell, and the wall charge is formed so that the sum of the voltage applied from the outside and the wall voltage of the cell maintains the discharge start voltage state. This principle is disclosed in US Pat. No. 5,745,086 to Weber. In the reset period, since the states of all cells must be initialized, the voltage Vset is high enough to cause a discharge in the cells of all conditions.

In the falling period of the reset period, the voltage of the Y electrode is gradually decreased from the Vs voltage to the Vnf voltage while the X electrode is maintained at the Ve voltage. Then, while the voltage of the Y electrode decreases, a weak discharge occurs between the Y electrode and the X electrode, and between the Y electrode and the A electrode, and the negative wall charges formed on the Y electrode and the positive wall charges formed on the X electrode and the A electrode. Is erased to initialize the discharge cells. In general, the magnitude of the (Vnf-Ve) voltage is set near the discharge start voltage between the Y electrode and the X electrode. As a result, the wall voltage between the Y electrode and the X electrode becomes almost 0 V, whereby a cell that does not have an address discharge in the address period can be prevented from being erroneously discharged in the sustain period.

The false discharge erase period serves to assist the reset period so that false discharge does not occur even when a strong discharge occurs due to an unstable reset operation. In this mis-discharge erasing period, the voltage of the Y electrode is gradually decreased from the voltage of Vs to the voltage of Vnf while the voltage of the X electrode is maintained at the Ve voltage. In this way, even if strong discharge occurs in the falling period of the reset period due to an unstable reset operation, it is possible to prevent a phenomenon in which discharge occurs in the sustain period even without an address discharge, that is, erroneous discharge.

Specifically, when weak discharge is normally performed in the falling period of the reset period, each electrode has a wall charge state as shown in FIG. 3A. In this state, no discharge occurs even when the voltage Vs is applied to the Y electrode in the erroneous discharge erasing period, so that the wall charge state becomes the same as the wall charge state after the end of the falling period. Then, while the voltage of the Y electrode decreases, a weak discharge occurs between the Y electrode and the X electrode and between the Y electrode and the A electrode, so that the negative wall charges formed on the Y electrode and the positive wall charges formed on the X electrode and the A electrode are reduced. Is erased.

On the other hand, when strong discharge occurs due to an unstable reset operation in the falling period of the reset period, each electrode has a wall charge state as shown in FIG. 3B. In this state, when the Vs voltage is applied to the Y electrode in the erroneous discharge erasing period, a discharge occurs to form a negative wall charge on the Y electrode and a positive wall charge on the X electrode. Then, while the voltage of the Y electrode decreases, a weak discharge occurs between the Y electrode and the X electrode and between the Y electrode and the A electrode, and a negative wall charge formed on the Y electrode and a positive wall formed on the X electrode and the A electrode. The charge is erased. Therefore, even if strong discharge occurs in the falling period of the reset period, no false discharge occurs.

In the address period, in order to select a discharge cell to emit light, a scan pulse having a VscL voltage is applied to a plurality of Y electrodes while a Ve voltage is applied to the X electrodes. At this time, the Va voltage is applied to the A electrode passing through the discharge cell to emit light among the plurality of discharge cells formed by the Y electrode and the X electrode to which the VscL voltage is applied. Then, an address discharge occurs between the A electrode to which the Va voltage is applied and the Y electrode to which the VscL voltage is applied, and the Y electrode to which the VscL voltage is applied, and the X electrode to which the Ve voltage is applied, thereby causing a positive wall charge, A, to the Y electrode. Negative wall charges are formed on the electrode and the X electrode, respectively. Here, the VscL voltage may be set at a level equal to or lower than the Vnf voltage. The VscH voltage higher than the VscL voltage is applied to the Y electrode to which the VscL voltage is not applied, and the reference voltage is applied to the A electrode of the discharge cell that is not selected.

Meanwhile, in order to perform this operation in the address period, the scan electrode driver 400 selects a Y electrode to which a scan pulse having a VscL voltage is applied among the Y electrodes Y1 to Yn. For example, in the single drive, the Y electrodes can be selected in the order arranged in the vertical direction. When one Y electrode is selected, the address electrode driver 300 selects a discharge cell to be turned on among discharge cells formed by the corresponding Y electrode. That is, the address electrode driver 300 selects a cell to which an address pulse of Va voltage is applied among the A electrodes A1 to Am.

Subsequently, in the sustain period, sustain discharge pulses having a high level voltage (Vs voltage in FIG. 2) and a low level voltage (0V voltage in FIG. 2) are alternately applied to the Y electrode and the X electrode in the opposite phase. That is, 0 V is applied to the X electrode when the Vs voltage is applied to the Y electrode, and 0 V is applied to the Y electrode when the Vs voltage is applied to the X electrode. Then, discharge occurs in the Y electrode and the X electrode by the wall voltage and the Vs voltage formed between the Y electrode and the X electrode by the address discharge in the address period. Thereafter, the process of applying the sustain discharge pulse to the Y electrode and the X electrode is repeated a number of times corresponding to the weight indicated by the corresponding subfield.

On the other hand, in the plasma display device, the discharge characteristics of the plasma display panel 100 vary with temperature. In detail, when the temperature of the plasma display panel 100 is high, the discharge start voltage is low, and when the temperature of the plasma display panel 100 is low, the discharge start voltage tends to be high. Due to this characteristic, strong discharge may occur when the voltage Vs is applied to the Y electrode in the false discharge erasure period even if the weak discharge is normally performed in the falling period of the reset period when the temperature of the plasma display panel 100 is high. This causes a problem that the contrast is lowered. Hereinafter, an embodiment capable of preventing such a decrease in contrast will be described in detail with reference to FIGS. 4 and 5.

4 is a diagram illustrating an operation of the controller illustrated in FIG. 1.

As shown in FIG. 4, the controller 200 receives the temperature of the plasma display panel 100 sensed by the temperature sensor 600 (S410) and compares the temperature with the reference temperature (S420). In this case, when the temperature of the plasma display panel 100 is higher than the reference temperature, the controller 200 transmits a control signal to the scan electrode driver 400 so that the voltage of the Y electrode gradually decreases from the VscH voltage during the erroneous discharge erase period. In operation S430 (see FIG. 5), when the plasma display panel 100 has a temperature lower than or equal to the reference temperature, a control signal for gradually decreasing the voltage of the Y electrode from the voltage Vs during the erroneous discharge erasing period may include a scan electrode driver ( 400) (S440, see FIG. 2). Here, the reference temperature may be generally set at about 65 degrees and may be set at other temperatures.

5 illustrates a driving waveform of the plasma display device according to the second exemplary embodiment of the present invention.

As shown in FIG. 5, when the temperature of the plasma display panel 100 is high, the voltage of the Y electrode is gradually decreased from the voltage lower than the voltage Vs to the voltage Vnf in the erroneous discharge erase period, unlike in FIG. 2. In FIG. 5, the VscH voltage is applied to the Y electrode at a voltage lower than the Vs voltage. When the VscH voltage is used at a voltage lower than the Vs voltage, an additional power supply does not need to be used. In this case, since the voltage difference (VscH-Ve) between the Y electrode and the X electrode is smaller than the voltage difference (Vs-Ve) between the Y electrode and the X electrode in the first embodiment, the high temperature in the wall charge state as shown in FIG. Even in this case, no discharge occurs. In the wall charge state as shown in FIG. 3B, the discharge may sufficiently occur due to the discharge start voltage lowered at high temperatures.

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, erroneous discharge due to strong discharge in the falling period of the reset period can be prevented, and in a plasma display device in which the discharge characteristic of the plasma display panel varies with temperature, a high temperature applied in the erroneous discharge erasing period at high temperatures It can prevent the strong discharge which can be caused by the voltage.

Claims (6)

A plurality of first electrodes and a plurality of second electrodes extending in parallel with each other and performing a display operation; and a plurality of third electrodes formed in a direction crossing the plurality of first electrodes and the plurality of second electrodes. In a plasma display device in which a plurality of discharge cells are formed at intersections of a plurality of first electrodes, a plurality of second electrodes, and a plurality of third electrodes, a method of driving one frame divided into a plurality of subfields, Sensing a temperature of the plasma display device; Initializing the plurality of discharge cells in a reset period, In a mis-discharge erasing period subsequent to the reset period, a first voltage and a third voltage are applied to the plurality of first electrodes and the plurality of second electrodes, respectively, and then the third voltage is applied to the plurality of second electrodes. Gradually decreasing the voltages of the plurality of first electrodes from the first voltage to the second voltage in the state where a high fourth voltage is applied, and Setting the first voltage when the temperature of the plasma display device is a first temperature lower than the first voltage when the temperature of the plasma display device is a second temperature lower than the first temperature. Method of driving a plasma display device comprising a. delete The method of claim 1, A fifth voltage is sequentially applied to the plurality of first electrodes during an address period, and a sixth voltage higher than the fifth voltage is applied to a first electrode of the plurality of first electrodes to which the fifth voltage is not applied. Step, and Alternately applying a sustain discharge pulse having a high level voltage and a low level voltage to the plurality of first electrodes and the plurality of second electrodes during a sustain period; More, When the first temperature is the first voltage is the same voltage as the sixth voltage, And the first voltage is the same voltage as the high level voltage at the second temperature. The method according to claim 1 or 3, The initializing step, Gradually increasing the voltages of the plurality of first electrodes from a seventh voltage to an eighth voltage while applying the third voltage to the plurality of second electrodes, and Gradually decreasing the voltages of the plurality of first electrodes from the ninth voltage lower than the eighth voltage to the second voltage while applying the fourth voltage to the plurality of second electrodes. Method of driving the device. A plurality of first electrodes and a plurality of second electrodes extending side by side while performing a display operation, a plurality of third electrodes formed in a direction crossing the plurality of first electrodes and the plurality of second electrodes, and the plurality of A plasma display panel including a plurality of discharge cells formed at intersections of a first electrode, the plurality of second electrodes, and the plurality of third electrodes; In the erroneous discharge erasing period between a reset period for initializing the plurality of discharge cells and an address period for selecting a cell to be turned on and a cell not to be turned on, the plurality of first electrodes and the plurality of second electrodes After applying the first voltage and the third voltage, respectively, the voltages of the plurality of first electrodes are changed from the first voltage to the second voltage with the fourth voltage higher than the third voltage applied to the plurality of second electrodes. A drive unit that gradually reduces to voltage, A temperature sensing unit sensing a temperature of the plasma display panel; A controller configured to set the first voltage at a temperature higher than a reference temperature of the plasma display panel to be lower than the first voltage at a temperature lower than the reference temperature of the plasma display panel; Plasma display device comprising a. The method of claim 5, The driving unit, The fifth voltage is sequentially applied to the plurality of first electrodes during the address period, and the sixth voltage higher than the fifth voltage is applied to the first electrode to which the fifth voltage is not applied among the plurality of first electrodes. , A sustain discharge pulse having a high level voltage and a low level voltage is alternately applied to the plurality of first electrodes and the plurality of second electrodes during the sustain period, The control unit, The first voltage is set to the sixth voltage when the temperature of the plasma display panel is higher than the reference temperature. And setting the first voltage at the temperature at which the temperature of the plasma display panel is equal to or less than the reference temperature to the high level voltage.

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