KR100649258B1 - Plasma display and driving method thereof - Google Patents

Abstract

A plasma display device and a driving method thereof are provided to perform stable discharge by applying positive voltage to an address electrode before a first sustain discharge pulse is applied to a scan electrode. A method for driving one frame according to subfields in a plasma display device, which is comprised of first and second electrodes performing display, and third electrodes(A) formed across the first and second electrodes, includes the steps of: applying sustain discharge pulse having a second voltage and a third voltage lower than the second voltage to the first and second electrodes at opposite phases, during a sustain period while applying a first voltage(Va) to the third electrodes; applying a fourth voltage to the third electrodes for a predetermined time of the sustain period right before the first sustain discharge pulse is applied; and differently setting a fourth voltage in a first subfield having a main reset period where all discharge cells are initialized, and in a second subfield having an auxiliary reset period where the discharge cell having displayed an image in the preceding subfield is initialized.

Description

Plasma display device and driving method thereof {PLASMA DISPLAY 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 frame (1TV field) is divided into a plurality of subfields having respective weights and driven, and gray scales are displayed by a combination of weights of subfields in which a display operation occurs among the plurality of subfields. In the address period of each subfield, discharge cells to emit light and discharge cells not to emit light are selected by the address discharge, 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 to display an image. do.

In this sustain period, a sustain discharge pulse having a high level voltage (for example, a Vs voltage) and a low level voltage (for example, 0 V) is applied to the scan electrode and the sustain electrode in opposite phases. In this case, first, a Vs voltage is applied to the scan electrode and a 0 V voltage is applied to the sustain electrode, so that sustain discharge occurs between the scan electrode and the sustain electrode, and the sustain discharge causes negative (-) wall charges and ( +) Wall charges are formed. At this time, since the 0V voltage is also applied to the address electrode, the positive wall charges are dispersed not only in the sustain electrode but also in the address electrode. Therefore, the wall electrodes are not formed sufficiently in the sustain electrode. In this state, when the Vs voltage is subsequently applied to the sustain electrode and the 0 V voltage is applied to the scan electrode, the sustain discharge is less likely to occur.

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 securing discharge stability and reducing power consumption.

According to an aspect of the present invention, a plurality of second electrodes performing a display operation together with a plurality of first electrodes and the plurality of first electrodes, and a plurality of cross-sectional directions formed to cross the first electrode and the second electrode A method of dividing and driving one frame into a plurality of subfields in a plasma display device including a third electrode is provided. The driving method includes a second voltage lower than the second voltage and the third voltage to the plurality of first electrodes and the plurality of second electrodes in a state where a first voltage is applied to the plurality of third electrodes in the sustain period. Applying a sustain discharge pulse having a phase to the opposite phase, applying a fourth voltage to the plurality of third electrodes for a predetermined period immediately before the first sustain discharge pulse is applied in the sustain period, and all the discharge cells. Differently setting the fourth voltage in the first subfield having the main reset period to initialize and the fourth voltage in the second subfield having the auxiliary reset period initializing the discharge cells displaying the image in the immediately preceding subfield. Steps.

According to another aspect of the present invention, a plasma display device including a plasma display panel, a driver, and a controller is provided. The plasma display panel includes a plurality of second electrodes performing a display operation together with a plurality of first electrodes and the plurality of first electrodes, and a plurality of third electrodes formed in a direction crossing the first electrode and the second electrode. And a plurality of discharge cells formed by the first electrode, the second electrode, and the third electrode. The driving unit has a sustain discharge pulse having a high level voltage and a low level voltage in the opposite phase to the plurality of first electrodes and the plurality of second electrodes in a state in which a first voltage is applied to the plurality of third electrodes in a sustain period. And a second voltage is applied to the plurality of third electrodes during the first period immediately before the sustain discharge pulse first applied in the sustain period. And in the second subfield having an auxiliary reset period for initializing a discharge cell displaying an image in the subfield immediately preceding the second voltage in the first subfield having a main reset period for initializing all discharge cells. It is set lower than the second voltage.

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 may include 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 the 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.

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

As shown in Fig. 2, in the rising period of the reset period, the voltage of the Y electrode gradually increases from the voltage Vs to the voltage Vset while the X electrode is held 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, 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, the voltage of the Y electrode gradually decreases 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, 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, 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, between the Y electrode and the X electrode of the discharge cell to be turned on. Sustain discharge occurs. At this time, the voltage Va1 is applied to the A electrode for a predetermined period before the sustain discharge pulse is first applied in time in the sustain period. In FIG. 2, the first sustain discharge pulse is applied to the Y electrode in the sustain period, but may be applied to the X electrode. As such, when the voltage Va1 is applied to the A electrode before the first sustain discharge pulse is applied to the Y electrode in the sustain period, (+) wall charges are moved to the Y electrode, and when the Vs voltage is subsequently applied to the Y electrode, The sustain discharge can stably occur between the Y electrode and the X electrode. Using the Va voltage as the Va1 voltage reduces the number of additional power sources. 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.

However, in order to apply the Va1 voltage to the A electrode, the power consumption of the A electrode side is increased due to the switching of the switching element connected between the power supply for supplying the Va1 voltage and the A electrode. Hereinafter, a driving method capable of reducing such power consumption will be described in detail with reference to FIG. 3.

3 illustrates a driving waveform of the plasma display device according to the second exemplary embodiment of the present invention. In the following, a reset period consisting of a rising period and a falling period is defined as a main reset period, and a reset period consisting of only a falling period is defined as a secondary reset period.

As shown in FIG. 3, according to the second exemplary embodiment of the present invention, the reference voltage is applied to the A electrode before the first sustain discharge pulse is applied to the Y electrode in the sustain period of the subfield having the main reset period, and the auxiliary reset is performed. The Va1 voltage is applied to the A electrode of the subfield having the period.

That is, in the plasma display device, the controller 200 determines whether the reset period of each subfield is a main reset period or an auxiliary reset period, and thus, A during the second period and the fourth period in the sustain period of the subfield having the main reset period. The control signal is applied to the address electrode driver 300 to apply the reference voltage to the electrode and to apply the Va1 voltage to the A electrode during the second and fourth periods in the sustain period of the subfield having the auxiliary reset period.

In general, in the subfield having the main reset period, since there is a rising period for forming wall charges, more wall charges may be formed in each electrode than in the auxiliary reset period without the rising period for forming wall charges. Therefore, in the subfield having the main reset period, there is a high probability that the sustain discharge occurs stably even when the voltage Va1 is not applied to the A electrode in the sustain period. As such, when the probability of the sustain discharge occurring stably without applying the Va1 voltage to the A electrode in the sustain period is high, the control may be such that the address auxiliary pulse is not applied to the A electrode in the sustain period, thereby reducing power consumption. On the other hand, the subfield having the auxiliary reset period has a higher probability that sustain discharge is less likely to occur in the sustain period because the wall charges formed in each electrode are relatively insufficient. Therefore, in the sustain period of the subfield having the auxiliary reset period, the discharge stability is secured by applying the Va1 voltage to the A electrode.

On the other hand, the auxiliary reset period will be described. In the reset period of the second subfield, that is, the auxiliary reset period, 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. . At this time, when sustain discharge is generated in the sustain period of the first subfield, since negative (-) wall charges are formed on the Y electrode and positive (+) wall charges are formed on the X electrode and the A electrode, the reset period of the first subfield is performed. As with the falling period of, the 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 to the negative (-) wall charge and the X electrode and the A electrode formed on the Y 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.

Since the address period and the sustain period of the second subfield are the same as the first subfield, detailed description thereof will be omitted. 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.

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, in the subfield having the auxiliary reset period in which the wall charge is insufficient in the cell and the sustain discharge is not probable, the first sustain discharge pulse is applied to the scan electrode (or the sustain electrode) in time. Discharge stability is ensured by applying a positive voltage to the A electrode before it is applied. Also, in a subfield having a main reset period in which a large amount of wall charges are formed so that sustain discharge is likely to occur, the reference voltage is applied to the A electrode before the first sustain discharge pulse is applied to the scan electrode (or sustain electrode) in time in the sustain period. The power consumption is reduced by applying.

Claims (6)

A plasma 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 plurality of third electrodes formed in a direction crossing the first electrode and the second electrode In the method of driving by dividing a frame into a plurality of subfields in the display device, A sustain discharge pulse having a second voltage and a third voltage lower than the second voltage to the plurality of first electrodes and the plurality of second electrodes while a first voltage is applied to the plurality of third electrodes in the sustain period Applying to the opposite phase, Applying a fourth voltage to the plurality of third electrodes for a predetermined period immediately before the first sustain discharge pulse is applied in the sustain period, and The fourth voltage in the first subfield having a main reset period for initializing all discharge cells and the fourth voltage in the second subfield having an auxiliary reset period for initializing a discharge cell displaying an image in the immediately preceding subfield. Differently setting the plasma display device; The method of claim 1, And a fourth voltage in the first subfield is lower than the fourth voltage in the second subfield. The method of claim 2, And a fourth voltage in the first subfield is equal to the first voltage. The method of claim 2, And the fourth voltage in the second subfield is the same as the voltage applied to the third electrode of the discharge cell to be turned on in the address period. A plurality of second electrodes performing a display operation together with a plurality of first electrodes and the plurality of first electrodes, and a plurality of third electrodes formed in a direction crossing the first electrode and the second electrode, A plasma display panel in which a plurality of discharge cells are formed by the first electrode, the second electrode, and the third electrode; In a sustain period, a sustain discharge pulse having a high level voltage and a low level voltage is applied to the plurality of first electrodes and the plurality of second electrodes in a state in which a first voltage is applied to the plurality of third electrodes in a reverse phase. A driver for applying a second voltage to the plurality of third electrodes during a first period immediately before a sustain discharge pulse first applied in the sustain period, and The second voltage in a second subfield having an auxiliary reset period for initializing a discharge cell displaying an image in the immediately preceding subfield with the second voltage in the first subfield having a main reset period for initializing all discharge cells. A plasma display device including a control unit which is set lower. The method of claim 5, The control unit, And the second voltage in the first subfield is set equal to the first voltage, and the second voltage in the second subfield is set to a voltage higher than the first voltage.

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