KR100740095B1 - Plasma display and driving method thereof - Google Patents

Abstract

In the plasma display device, sustain discharge pulses are alternately applied to the plurality of scan electrodes and the plurality of sustain electrodes in the sustain period to sustain discharge the selected discharge cells. At this time, the discharge efficiency is increased by applying address auxiliary pulses to the plurality of address electrodes in a plurality of first periods positioned between the sustain discharge pulses applied to the plurality of scan electrodes and the sustain discharge pulses applied to the plurality of scan electrodes. However, when the address auxiliary pulses are applied in every frame, the power consumption increases, so that in the sustain period of the subfield having the main reset period for initializing all the discharge cells, the discharge is displayed in the immediately preceding subfield without applying the address auxiliary pulses. The address auxiliary pulse is applied in the sustain period of the subfield having the auxiliary reset period for initializing the cell. In this way, power consumption can be reduced compared to applying the address auxiliary pulses in the plurality of first periods of all the subfields, and sustain discharge is not probable well, that is, discharge stability is secured in the subfields having the auxiliary reset period. can do.

PDP, electrode, discharge, power consumption, main reset, auxiliary reset, holding period

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, there is a problem in that the luminous efficiency caused by the sustain discharge is lowered.

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 improving luminous efficiency.

According to an aspect of the present invention, a plasma display panel, a driver, and a controller are included. 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 applies a first sustain discharge pulse and a second sustain discharge pulse to the plurality of first electrodes and the plurality of second electrodes, respectively, in the sustain period, and between the first sustain discharge pulse and the second sustain discharge pulse. The first voltage is applied to the plurality of third electrodes in the plurality of first periods positioned. The control unit may further include the first subfield having a main reset period for initializing all discharge cells, and the first subfield having a secondary reset period for initializing a discharge cell displaying an image in the immediately preceding subfield. Set the voltage differently. In this case, the first sustain discharge pulse and the second sustain discharge pulse have a high level voltage and a low level voltage in opposite phases.

According to another feature 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 are formed in a direction crossing the first electrode and the second electrode. A method of driving a frame by dividing the frame into a plurality of subfields in a plasma display device including a plurality of third electrodes is provided. The driving method includes applying a first sustain discharge pulse and a second sustain discharge pulse to the plurality of first electrodes and the plurality of second electrodes, respectively, in the sustain period, the first sustain discharge pulse and the second sustain. Applying a first voltage to the plurality of third electrodes in a plurality of first periods between discharge pulses, and a subfield immediately preceding the first voltage in a first subfield having a main reset period for initializing all discharge cells; And differently setting the first voltage in a second subfield having an auxiliary reset period for initializing a discharge cell displaying an image, wherein the first sustain discharge pulse and the second sustain discharge pulse are high level voltage. And low level voltage in opposite phase.

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.

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 discharge cells to emit light, scan pulses having a VscL voltage are 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 (0 V in FIG. 2) is applied to the Y electrode and the X electrode during the first period and the third period to discharge to be turned on. A sustain discharge occurs between the Y electrode and the X electrode of the cell. And an address auxiliary pulse having a high level voltage (Va1 voltage in FIG. 2) and a low level voltage (0 V in FIG. 2) at the A electrode during the second and fourth periods between the sustain discharge pulses applied to the Y electrode and the X electrode. Apply. In FIG. 2, the high level voltage of the address auxiliary pulse is illustrated as the Va1 voltage, but the Va voltage may be used. Using the Va voltage as the high level voltage for the address auxiliary pulses reduces the number of additional power supplies than using other voltages. Thereafter, the process of applying the sustain discharge pulse to the Y electrode and the X electrode and the process of applying the address auxiliary pulse to the A electrode are repeated the number of times corresponding to the weight indicated by the corresponding subfield.

Specifically, in the first period of the sustain period, the voltage Vs is applied to the Y electrode and the voltage 0 V is applied to the A electrode and the X electrode. Then, in the address period, sustain discharge occurs between the Y electrode and the X electrode due to the wall voltage formed between the Y electrode and the X electrode and the Vs voltage, and a negative wall charge is formed on the Y electrode and the X electrode and the A electrode. Positive wall charges are formed.

Then, in the second period of the sustain period, a 0 V voltage is applied to the Y electrode and the X electrode and a Va1 voltage is applied to the A electrode. Then, a discharge occurs between the Y electrode and the A electrode by the wall voltage formed between the Y electrode and the A electrode and the Va1 voltage, thereby forming a positive wall charge on the Y electrode and a negative wall charge on the A electrode. do. At this time, since the 0V voltage is applied to the X electrode, since the (+) wall charge is formed not only on the Y electrode but also on the X electrode, the (+) wall charge increases on the X electrode.

In the third period of the sustain period, the 0 V voltage is applied to the Y electrode and the A electrode, and the Vs voltage is applied to the X electrode. Then, since a large amount of positive wall charges are formed in the X electrode in the second period, sustain discharge occurs well between the Y electrode and the X electrode. As a result, positive wall charges and negative wall charges are formed on the Y electrode and the X electrode, respectively.

Then, in the fourth period of the sustain period, a 0V voltage is applied to the Y electrode and the X electrode and a Vs voltage is applied to the A electrode. At this time, a discharge occurs between the X electrode and the A electrode by the wall voltage formed between the X electrode and the A electrode and the Va1 voltage, thereby forming a positive wall charge on the X electrode and a negative wall charge on the A electrode. do. In addition, as the positive wall charges are attracted to the Y electrode, the positive wall charges increase in the Y electrode. Therefore, sustain discharge occurs well between the Y electrode and the X electrode when the Vs voltage is applied to the Y electrode and the 0 V voltage is applied to the X electrode in the subsequent first period.

In this way, by applying the address auxiliary pulse to the A electrode in the sustain period, discharge stability can be ensured in the sustain period, and in addition to the electric field between the X electrode and the Y electrode in the sustain period, between the Y electrode and the A electrode. In addition, since an electric field is formed to widen the discharge region, and the vacuum ultraviolet rays generated during discharge can be more efficiently transmitted to the phosphor layer, the brightness and discharge efficiency of the plasma display device are improved. However, in order to apply the Va1 voltage to the A electrode in the second and fourth periods, the switching element connected between the power supply supplying the Va1 voltage and the A electrode needs to repeatedly turn on and off, thereby causing the A electrode. The power consumption is increased on the side, and the efficiency increase is lowered. 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 embodiment of the present invention, in the sustain period of the subfield having the main reset period, A is not applied to the A electrode but only in the sustain period of the subfield having the auxiliary reset period. The voltage Va1 is applied to the electrode.

That is, in the plasma display device, the controller 200 determines whether the reset period of each subfield is the main reset period or the auxiliary reset period, and in the case of the main reset period, the second period and the fourth period of the sustain period of the corresponding subfield. In the address electrode driver 300, a reference signal is applied to the A electrode, and in the auxiliary reset period, a control signal is applied to the A electrode in the second and fourth periods of the sustain period of the corresponding subfield. To pass.

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 address auxiliary pulse is not applied to the A electrode. As described above, when the probability of the sustain discharge occurring stably even without the address assist pulse is high, the power consumption can be reduced by controlling not to apply the address assist pulse to the A electrode in the sustain period. 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 at each electrode are relatively insufficient. Therefore, in the subfield having the auxiliary reset period, the address auxiliary pulse is applied to the A electrode in the sustain period to ensure discharge stability.

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 has occurred 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 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 the 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 a main reset period in which a large number of wall charges are formed so that sustain discharge is likely to occur, power consumption is reduced and maintained by not applying an address auxiliary pulse to the A electrode. In a subfield having an auxiliary reset period in which discharge does not occur stochasticly, discharge stability can be ensured by applying a pulse to the A electrode.

Claims (6)

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 the sustain period, a first sustain discharge pulse and a second sustain discharge pulse are applied to the plurality of first electrodes and the plurality of second electrodes, respectively, and positioned between the first sustain discharge pulse and the second sustain discharge pulse. A driver for applying a first voltage to the plurality of third electrodes in the plurality of first periods, and The first voltage is different in the first subfield having a main reset period for initializing all discharge cells and in the second subfield having an auxiliary reset period for initializing a discharge cell displaying an image in the immediately preceding subfield. It includes a control unit for setting, And the first sustain discharge pulse and the second sustain discharge pulse have a high level voltage and a low level voltage in opposite phases. The method of claim 1, The control unit, The voltage applied to the plurality of third electrodes during the plurality of first periods in the second subfield is set higher than the voltage applied to the plurality of third electrodes during the plurality of first periods in the first subfield. Plasma display device. The method of claim 2, The voltage applied to the plurality of third electrodes during the plurality of first periods 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. And a voltage applied to the plurality of third electrodes during the first period in the first subfield is equal to a voltage applied to the third electrode of the discharge cell that will not be turned on. The method according to any one of claims 1 to 3, The driving unit, Discharge cells that are not turned on in the address period to the plurality of third electrodes while the first sustain discharge pulse and the second sustain discharge pulse are respectively applied to the plurality of first electrodes and the plurality of second electrodes in the sustain period. And a voltage equal to the voltage applied to the third electrode of the plasma display device. 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, Applying a first sustain discharge pulse and a second sustain discharge pulse to the plurality of first electrodes and the plurality of second electrodes, respectively, in the sustain period, Applying a first voltage to the plurality of third electrodes in a plurality of first periods between the first sustain discharge pulse and the second sustain discharge pulse, and The first voltage is different in the first subfield having a main reset period for initializing all discharge cells and in the second subfield having an auxiliary reset period for initializing a discharge cell displaying an image in the immediately preceding subfield. Setting up, And the first sustain discharge pulse and the second sustain discharge pulse have a high level voltage and a low level voltage in opposite phases. The method of claim 5, Applying a second voltage to the third electrode of the discharge cell to be turned on in the address period and applying a third voltage lower than the second voltage to the third electrode of the discharge cell to be turned on, The first voltage of the first subfield is equal to the third voltage, And the first voltage of the second subfield is the same as the second voltage.

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