KR100708858B1 - Plasma display device and driving method thereof - Google Patents

Abstract

In the plasma display device, sustain discharge pulses having a high level voltage and a low level voltage are applied to the plurality of scan electrodes and the plurality of sustain electrodes in a sustain period in an opposite phase. In this case, a time for changing the sustain discharge pulse last applied to the sustain electrode to the high level voltage is set differently according to the temperature of the plasma display device. That is, the sustain discharge pulse last applied to the sustain electrode when the temperature of the plasma display device is low is changed from the last sustain pulse applied to the sustain electrode when the temperature of the plasma display device is high to the high level voltage. It is shorter than the time to change to the high level voltage in. In this way, low discharge that may occur when the temperature of the plasma display device is high can be prevented.

PDP, electrode, discharge, temperature, voltage, low discharge, sustain discharge pulse

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 and 3 illustrate driving waveforms of the plasma display device according to the first and second exemplary embodiments of the present invention, respectively.

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 that displays text or an image by using plasma generated by gas discharge. In the plasma display panel, dozens to millions or more of discharge cells are arranged in a matrix form according to their size.

In the plasma display device, one field (1TV field) is divided into a plurality of subfields having respective weights and driven, and the gray level is displayed by a combination of the weights of the subfields in which the display operation occurs among the plurality of subfields. In the address period of each subfield, the discharge cells to emit light and the discharge cells not to emit light by the address discharge are selected, and the discharge cells to emit light selected in the sustain period are sustained and discharged for a period corresponding to the weight of the subfield so that the image is displayed. Is displayed. Such a plasma display device has a characteristic that the discharge characteristics of the plasma display panel vary with temperature. In particular, the movement of electrons becomes more active in the discharge space at a high temperature, so that the wall discharges of the discharge cells addressed later in time are lost in the address period in which the scanning pulses are sequentially applied to select the discharge cells to emit light. It may not happen.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a plasma display device and a driving method thereof capable of generating stable address discharge even at a high temperature.

According to an aspect of the present invention, a plasma display panel including a plurality of first electrodes and a plurality of second electrodes performing a display operation together with the plurality of first electrodes, and a temperature sensing sensing a temperature of the plasma display panel. A driving unit for applying a sustain discharge pulse having a first voltage and a second voltage higher than the first voltage to the plurality of first electrodes and the plurality of second electrodes in an opposite phase in the sustain period, and the plasma display panel And a controller configured to differently set a time from the last sustain discharge pulse applied to the plurality of first electrodes to the second voltage according to a temperature of.

According to another aspect of the present invention, a method of driving a frame divided into a plurality of subfields in a plasma display device including a plurality of scan electrodes and a plurality of sustain electrodes performing a display operation together with the plurality of scan electrodes Is provided. The driving method includes applying a sustain discharge pulse having a high level voltage and a low level voltage to the plurality of scan electrodes and the plurality of sustain electrodes in a reverse phase in a sustain period, and sensing a temperature of the plasma display device. And differently setting a time for changing from the sustain discharge pulse last applied to the sustain electrode to the high level voltage according to the sensed 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, and like reference numerals designate like parts throughout the specification. In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

In addition, the wall charge in the present invention refers to a charge formed close to each electrode on the wall (eg, the dielectric layer) of the cell. 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.

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 scan electrode driver 400, and a sustain 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 to 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 the cell 12. 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 scan electrode driver 400 receives a Y electrode driving control signal from the controller 200 and applies a driving voltage to the Y electrode.

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

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

2 and 3 illustrate driving waveforms of the plasma display device according to the first and second exemplary embodiments of the present invention, respectively. In the following description, only the driving waveforms applied to the Y electrode, the X electrode, and the A electrode forming one cell will be described.

First, as shown in FIG. 2, in the rising period of the reset period of the first subfield, the voltage of the Y electrode gradually increases from the Vs voltage to the Vset voltage while the X electrode is maintained at the reference voltage (0 V in FIG. 2). do. In FIG. 2, the voltage of the Y electrode is shown to increase in the form of a lamp. Then, while the voltage of the Y electrode is increased, a weak discharge (hereinafter referred to as “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 is applied to the Y electrode. And a positive wall charge is formed on the X and A electrodes.

In the falling period of the reset period of the first subfield, the voltage of the Y electrode is gradually decreased from the Vs voltage to the Vnf voltage while the Ve voltage is applied to 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 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.

In the address period of the first subfield, in order to select a discharge cell to emit light, a scan pulse having a VscL voltage is sequentially 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.

In the sustain period of the first subfield, a sustain discharge pulse having a high level voltage (Vs voltage in FIG. 2) and a low level voltage (0V in FIG. 2) is applied to the Y electrode and the X electrode in the opposite phase to Y of the discharge cell to be turned on. A sustain discharge occurs between the electrode and the X electrode. 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, sustain discharge occurs between the Y electrode and the X electrode by the wall voltage formed between the Y electrode and the X electrode and the Vs voltage 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. In FIG. 2, it is assumed that the time of changing from the low level voltage to the high level voltage and the time of changing from the high level voltage to the low level voltage when the sustain discharge pulse is applied are the same.

Subsequently, unlike the first subfield, the reset period of the second subfield includes only the falling period. In the following, a reset period consisting only of a falling period is defined as a secondary reset period. In the auxiliary reset period, while the Ve voltage is applied to the X electrode, the voltage of the Y electrode is gradually decreased from the Vs voltage to the Vnf voltage. At this time, when sustain discharge occurs in the sustain period of the first subfield, since the negative (-) wall charge is formed on the Y electrode and the positive (+) wall charge is formed on the X electrode and the A electrode, the reset group of the first subfield is performed. As with the falling period of the liver, 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 gradually decreased, so that the negative wall charges formed on the Y electrode and the X electrode and the A electrode The positive wall charges formed are erased to initialize the discharge cells. At this time, since the final voltage Vnf of the Y electrode in the auxiliary reset period is the same as the final voltage Vnf of the Y electrode in the reset period of the first subfield, the wall charge state of the cell after the completion of the auxiliary reset period is determined in the first subfield. It becomes substantially the same as the wall charge state after completion of the reset period. The cell in which the address discharge has not occurred in the address period of the first subfield maintains the wall charge state after the end of the reset period of the first subfield. Since the wall voltage formed in the cell after the end of the reset period of the first subfield is formed near the discharge start voltage along with the applied voltage, no discharge occurs when the voltage of the Y electrode decreases to the Vnf voltage. Therefore, since such a discharge does not occur in the auxiliary reset period, the cell maintains the wall charge state set in the reset period of the first subfield. In this way, in the subfield formed of the auxiliary reset period, reset discharge occurs when sustain discharge occurs in the immediately preceding subfield, and reset discharge does not occur when there is no sustain discharge.

Subsequently, the address period and the sustain period of the second subfield are the same as the first subfield. However, in the sustain period of the second subfield, the sustain discharge pulse is applied to the Y electrode and the X electrode in the opposite phase by the number of times corresponding to the weight indicated by the corresponding subfield.

In the plasma display device driven as described above, the controller 200 compares the temperature of the plasma display panel 100 sensed by the temperature sensor 600 with a threshold value, and when the detected temperature is higher than the threshold value, the control unit 200 immediately before the auxiliary reset period. In the sustain period, the time for changing the Vs voltage in the last sustain discharge pulse applied to the X electrode is shortened.

For example, in the plasma display device, the control unit 200 may provide a control signal for applying the driving waveform shown in FIG. 2 when the temperature of the plasma display panel 100 is lower than the threshold value. If the temperature of the plasma display panel 100 is higher than the threshold, the control unit 200 transmits a control signal for applying the driving waveform shown in FIG. 3 to each of the driving units 300, 400, and 500. do.

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

As shown in FIG. 3, the driving waveform according to the second embodiment of the present invention is a high level voltage Vs at a low level voltage (0V) of a sustain discharge pulse last applied to the X electrode in the sustain period immediately before the auxiliary reset period. Same as the first embodiment of the present invention except that the time to change is different.

Specifically, the time T3 when the driving waveform according to the second embodiment of the present invention changes from the 0 V voltage of the last sustain discharge pulse applied to the X electrode in the sustain period just before the auxiliary reset to the Vs voltage is shown in FIG. 2. It is shorter than the time T3 which changes from the 0V voltage of the last sustain discharge pulse applied to the X electrode in the drive waveform to the Vs voltage. As a result, the time T4 at which the Vs voltage of the last sustain discharge pulse applied to the X electrode is applied in the sustain period immediately before the auxiliary reset period is applied to the Vs voltage of the last sustain discharge pulse applied to the X electrode in the driving waveform shown in FIG. This becomes longer than the applied time T2. Accordingly, more negative wall charges and positive wall charges can be formed in the Y electrode and the X electrode in the sustain period just before the auxiliary reset period than in the first embodiment of the present invention. Even though the wall charge is erased through the auxiliary reset period, the auxiliary reset period is the same as the driving waveform of FIG. 2. As a result, even after the auxiliary reset period, the negative wall charge and ( +) More wall charge remains. Therefore, when the temperature of the plasma display panel 100 is higher than the threshold, low driving can be prevented by applying the driving waveform shown in FIG. 3.

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.

As described above, according to the present invention, when the temperature of the plasma display panel is higher than the threshold, the voltage is changed from the low level voltage of the last sustain discharge pulse applied to the X electrode to the high level voltage in the sustain period just before the auxiliary reset. By shortening time, low discharge is prevented.

Claims (8)

A plasma display panel including a plurality of first electrodes and a plurality of second electrodes performing a display operation together with the plurality of first electrodes; A temperature sensing unit sensing a temperature of the plasma display panel; In the sustain period, a sustain discharge pulse having a first voltage and a second voltage higher than the first voltage is applied to the plurality of first electrodes and the plurality of second electrodes in an opposite phase to thereby provide the plurality of first electrodes and the plurality of electrodes. A driving unit for performing sustain discharge between the second electrodes of And a controller configured to set different time periods from the first voltage to the second voltage of the last sustain discharge pulses applied to the plurality of first electrodes according to temperatures of the plasma display panel. The method of claim 1, The control unit, The time at which the temperature of the plasma display panel is changed from the first voltage of the last sustain discharge pulse to the second voltage at a first temperature is measured at a second temperature at which the temperature of the plasma display panel is lower than the first temperature. And a setting period shorter than a time for changing from the first voltage to the second voltage of the last sustain discharge pulse. The method of claim 2, The driving unit, Scanning pulses are sequentially applied to the plurality of second electrodes during an address period, And performing initialization for a cell in which sustain discharge has occurred in the sustain period during the sustain period. The method according to any one of claims 1 to 3, And the last sustain discharge pulse is applied to the plurality of second electrodes after the last sustain discharge pulse is applied to the plurality of first electrodes in the sustain period. In a plasma display device including a plurality of scan electrodes and a plurality of sustain electrodes for performing a display operation together with the plurality of scan electrodes, a method of driving one frame divided into a plurality of subfields is provided. Applying a sustain discharge pulse having a high level voltage and a low level voltage to the plurality of scan electrodes and the plurality of sustain electrodes in a sustain period in an opposite phase, Sensing a temperature of the plasma display device, and Setting a different period of time from the low level voltage of the last sustain discharge pulse applied to the plurality of sustain electrodes to the high level voltage according to the sensed temperature Method of driving a plasma display device comprising a. The method of claim 5, When the temperature of the plasma display device is higher than a threshold, the period of changing from the low level voltage of the last sustain discharge pulse to the high level voltage when the temperature of the plasma display device is lower than the threshold; A method of driving a plasma display device which is shorter than a period of changing from a low level voltage to the high level voltage. The method of claim 6, The period having the high level voltage in the last sustain discharge pulse when the temperature of the plasma display device is higher than the threshold has the high level voltage in the last sustain discharge pulse when the temperature of the plasma display device is lower than the threshold value. A method of driving a plasma display device longer than the period. The method according to any one of claims 5 to 7, The sustain period ends after the last sustain discharge pulse is applied to the plurality of sustain electrodes and then the sustain discharge pulse is applied to the plurality of scan electrodes. And gradually decreasing voltages of the plurality of scan electrodes during the reset period subsequent to the sustain period while the high level voltages of the sustain discharge pulses are applied to the plurality of scan electrodes.

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