KR100536246B1 - Driving method thereof plasma display device - Google Patents

Abstract

The present invention relates to a method of driving a plasma display device. According to the present invention, when the scan voltage is sequentially applied to the Y electrode, the Y electrode is divided into a plurality of groups according to the scanning order, the scan voltage is set differently for each group, and the scan voltage is applied to the first Y electrode of each group. Before the voltage of the Y electrode is gradually lowered and the bias voltage of the X electrode is further included. In this case, since the state of the discharge cell before the application of the scan voltage is restored to the state immediately after the reset, the address discharge efficiency can be increased, and the voltage difference between the X-Y electrodes can be compensated to prevent erroneous discharge from occurring in the sustain period.

Description

Driving method of plasma display device {DRIVING METHOD THEREOF PLASMA DISPLAY DEVICE}

The present invention relates to a method of driving a plasma display device.

Among the flat panel display devices, the plasma display device has been in the spotlight as a flat panel display device due to the advantages of higher luminance and luminous efficiency and a wider viewing angle than other display devices.

Plasma display devices are flat display devices that display characters or images using plasma generated by gas discharge, and dozens to millions or more of pixels are arranged in a matrix form according to their size. First, the structure of the plasma display device will be described with reference to FIG. 1.

1 is a partial perspective view of a plasma display device.

As shown in FIG. 1, the plasma display device includes two glass substrates 1 and 6 facing away from each other. On the glass substrate 1, the scan electrode 4 and the sustain electrode 5 are formed in pairs and in parallel, and the scan electrode 4 and the sustain electrode 5 are covered with the dielectric layer 2 and the protective film 3. have. A plurality of address electrodes 8 are formed on the glass substrate 6, and the address electrodes 8 are covered with the insulator layer 7. The address electrode 8 and the partition 9 are formed on the insulator layer 7 between the address electrodes 8. In addition, the phosphor 10 is formed on the surface of the insulator layer 7 and on both sides of the partition wall 9. The glass substrates 1 and 6 are disposed to face each other with the discharge space 11 therebetween so that the scan electrode 4, the address electrode 8, the sustain electrode 5, and the address electrode 8 are orthogonal to each other. The discharge space 11 at the intersection of the address electrode 8 and the paired scan electrode 4 and the sustain electrode 5 forms a discharge cell 12.

The electrode of the plasma display panel has a matrix structure of n × m. The plurality of address electrodes A ₁ -A _m are arranged in the vertical direction, and the plurality of scan electrodes Y ₁ -Y _n and the storage electrodes X ₁ -X _n are arranged in pairs in the horizontal direction.

In general, a plasma display device is driven by dividing one frame into a plurality of subfields, and gray levels are expressed by a combination of subfields. In general, each subfield includes a reset period, an address period, and a sustain period.

The reset period serves to erase the wall charges formed by the previous sustain discharge and to set up the wall charges in order to stably perform the next address discharge. The address period is a period in which a wall charge is accumulated in a cell (addressed cell) that is turned on by selecting a cell that is turned on and a cell that is not turned on in the panel. The sustain period is a period in which sustain discharge is performed to actually display an image in the addressed cells.

In this case, the wall charge refers to a charge formed in the wall of the discharge cell (eg, the dielectric layer) close to each electrode and accumulated in the electrode. Such wall charges are not actually in contact with the electrodes themselves, but here wall charges are described as "formed", "accumulated" or "stacked" on the electrodes. In addition, wall voltage refers to the potential difference formed in the wall of a discharge cell by wall charge.

2 is a view showing a driving waveform according to the prior art.

As shown in FIG. 2, at the end of the reset period, the voltage of the scan electrode is maintained while the sum of the wall voltage between the scan electrode and the sustain electrode and the voltages applied to the scan electrode and the sustain electrode is close to the discharge start voltage. Was lowered to the voltage VscL. In the address period, scan pulses having the low voltage VscL and the high voltage VscH are sequentially applied to the scan electrodes, and at the same time, data pulses are applied to the address electrodes to cause address discharge.

On the other hand, the address discharge is determined by the density of the priming particles and the wall voltage formed in the discharge space. However, since the time when the scan pulse is applied after the reset discharge is generated toward the bottom of the panel from the first scan electrode toward the bottom of the panel, the density of the priming particles is gradually lowered toward the bottom of the panel. Further, the wall voltage gradually collapses toward the lower end, and the voltage on the discharge space gradually decreases. Therefore, there is a problem that the discharge delay time is longer toward the bottom, thereby reducing the address margin.

An object of the present invention is to provide a method of driving a plasma display device which can improve a discharge margin in an address period.

According to an aspect of the present invention, there is provided a driving method of a plasma display device including a plurality of first electrodes, second electrodes, and address electrodes.

Dividing the plurality of first electrodes into a plurality of groups including a first group and a second group,

In the address period,

a) sequentially applying a scan pulse of a second voltage level to a first electrode belonging to the first group while biasing the voltage of the second electrode to a first voltage; b) gradually lowering the voltage of the first electrode to a third voltage; And c) a scan pulse of a fifth voltage level lower than the second voltage level sequentially to the first electrode belonging to the second group while biasing the voltage of the second electrode to a fourth voltage lower than the first voltage. Applying a.

Further, in step b),

The voltage of the second electrode is lowered to the fourth voltage, and the voltage of the first electrode is gradually lowered from the second voltage to the third voltage.

At this time, the third voltage and the fifth voltage is substantially the same,

The voltage difference between the first voltage and the second voltage and the voltage difference between the fourth voltage and the fifth voltage may be set to be substantially the same.

In addition, the plurality of groups further includes a third group,

After step c),

d) gradually lowering the voltage of the first electrode to a seventh voltage; And e) a scan pulse of an eighth voltage level lower than the fifth voltage level sequentially to a first electrode belonging to the third group in a state in which the voltage of the second electrode is biased to a sixth voltage lower than the fourth voltage. It may further comprise the step of applying.

At this time, the seventh voltage and the eighth voltage are substantially the same,

The voltage difference between the first voltage and the second voltage and the voltage difference between the sixth voltage and the eighth voltage may be substantially the same.

A driving method of a plasma display device according to another aspect of the present invention is a driving method of a plasma display device including a plurality of first electrodes, second electrodes, and address electrodes.

Dividing the plurality of first electrodes into a plurality of groups including a first group, a second group, and a third group,

In the address period,

a) sequentially applying a scan pulse of a second voltage level to a first electrode belonging to the first group while biasing the voltage of the second electrode to a first voltage; b) gradually lowering the voltage of the first electrode to the third voltage while biasing the voltage of the second electrode to the first voltage; c) sequentially applying a scan pulse of a fourth voltage level lower than the second voltage level to a first electrode belonging to the second group; d) gradually lowering the voltage of the first electrode to a fifth voltage; And e) a scan pulse of a seventh voltage level lower than the fourth voltage level sequentially to the first electrode belonging to the third group while biasing the voltage of the second electrode to a sixth voltage lower than the first voltage. Applying a.

DETAILED DESCRIPTION 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.

First, a plasma display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 3.

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

As shown in FIG. 3, a plasma display device according to an exemplary embodiment of the present invention includes a plasma display panel 100, an address driver 200, a Y electrode driver 320, an X electrode driver 340, and a controller 400. Include.

The plasma display panel 100 includes a plurality of address electrodes A1 to Am arranged in the column direction, first electrodes Y1 to Yn (hereinafter referred to as Y electrodes), and second electrodes arranged in the row direction. X1 to Xn) (hereinafter referred to as X electrode).

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

The Y electrode driver 320 and the X electrode driver 340 receive the Y electrode driving signal SY and the X electrode driving signal SX from the controller 200 and apply them to the X electrode and the Y electrode, respectively.

The control unit 400 receives an image signal from the outside, generates an address driving control signal SA, a Y electrode driving signal SY, and an X electrode driving signal SX, respectively, and generates an address driving unit 200 and a Y electrode driving unit ( 320 and the X electrode driver 340.

4 is a driving waveform diagram applied to the plasma display panel according to the first embodiment of the present invention.

As shown in FIG. 4, according to the first embodiment of the present invention, when the scan voltage is sequentially applied to the Y electrode, the Y electrode is divided into a plurality of groups according to the scanning order, and the scan voltage is set differently for each group. Further, the method further includes a period of gradually lowering the voltage of the Y electrode, such as a falling ramp reset period, before applying the scan voltage to the first Y electrode of each group. In FIG. 4, the Y electrode is divided into three groups (first, second, and third scan groups) for convenience.

That is, after the voltage of the Y electrode is lowered to the voltage VscL1 in the falling reset period, the scan pulses of the voltage VscL1 are sequentially applied to the first scan group while the voltage VscH1 is applied to all the Y electrodes in the address period. Is authorized. At this time, the voltage of the Y electrode after the addressing of the first scan group is completed is the voltage VscL1.

However, while the scan voltage pulse is applied to the first scan group, the wall voltage may collapse in the discharge cell including the Y electrode of the second scan group, so that only the scan voltage pulse of the voltage VscL1 may not generate stable address discharge. Therefore, the voltage of the Y electrode is gradually lowered from the voltage VscL1 to the voltage VscL2 before addressing the second scan group. Then, a weak discharge is generated between the X electrode and the Y electrode and the wall charge is erased, such as by applying the falling ramp waveform in the reset period, so that the state of the discharge cell is restored to an easy state for address discharge. Therefore, in this state, if the scan pulses of the voltage VscL2 are sequentially applied to the second scan group, stable address discharge can be caused. At this time, the voltage applied to the unselected scan lines of the second scan group is also lowered to the voltage VscH2 in order to make the address conditions of the first scan group and the second scan group the same.

Similarly, after applying the scan voltage pulses sequentially to the second scan group and before applying the scan voltage pulses to the third scan group to increase the address discharge efficiency of the third scan group, the voltage of the Y electrode is changed from the voltage VscL2. After gradually lowering to VscL3, scan voltage pulses of the voltage VscL3 are sequentially applied to the third scan group.

On the other hand, according to the first embodiment of the present invention to compensate for the wall charge loss of the A electrode of the lower panel to further include a period of gradually lowering the voltage of the Y electrode before applying the scan voltage to the first Y electrode of each group On the other hand, since the voltage of the X electrode is biased to a constant voltage during the address period, the voltage difference between the X electrode and the Y electrode increases toward the lower side of the panel. Therefore, a discharge occurs between X-Y electrodes in a discharge cell that is not selected in the address period, and eventually discharge may occur even in the sustain period.

Therefore, in the second embodiment of the present invention, in addition to lowering the voltage of the Y electrode for each group in the address period, the bias voltage of the X electrode is also lowered in steps. This second embodiment of the present invention will be described in detail with reference to FIG.

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

Referring to FIG. 5, the driving waveform according to the second embodiment of the present invention is the same as the first embodiment of the present invention except that the voltages of the X electrodes of each group are differently set in the address period.

Specifically, in the first embodiment of the present invention, the Y electrode is divided into a plurality of groups according to the order in which the scan pulses are applied, and the scan pulse voltage is set differently for each group. In the second embodiment of the present invention, the X electrode Is divided into a plurality of groups so as to correspond to each group of Y electrodes. The voltage of the Y electrode is gradually lowered and the voltage of the X electrode of each group is lowered before the scan voltage is applied to the first Y electrode of each group during the address period.

That is, while the voltage VscH1 is applied to all the Y electrodes in the address period, the scan pulses of the voltage VscL1 are sequentially applied to the first scan group, and the X electrode group corresponding to the first scan group is set to the Ve voltage. Bias.

When addressing the first scan group is completed as described above, the voltage of the Y electrode is gradually lowered from the voltage VscL1 to the voltage VscL2 before addressing the second scan group. At this time, the bias voltage of the X electrode group corresponding to the second scan group is also lowered to a Ve1 voltage lower than Ve. Then, as the voltage of the second scan group is lowered, the voltage difference between the X-Y electrodes can be compensated for, so that erroneous discharge can be prevented in the sustain period.

Similarly, after applying the scan pulses of the voltage VscL2 to the second scan group sequentially and completing the addressing, the voltage of the Y electrode is changed from the voltage VscL2 to the voltage VscL3 before the scan voltage pulse is applied to the third scan group. Slowly lower until In addition, the bias voltage of the X electrode group corresponding to the third scan group is also lowered to the Ve2 voltage lower than Ve1 to compensate for the increase in the voltage difference between the X and Y electrodes.

On the other hand, in the second embodiment of the present invention, the voltage of the X electrode group corresponding to each scan group is set differently, but as the third embodiment of the present invention, as shown in FIG. 6, the voltage of the XY electrode in the address period is shown. As long as the voltage maintains a voltage that does not cause erroneous discharge in the sustain period, even if the voltage of the Y electrode is lowered, it can be kept constant without lowering the bias voltage of the X electrode. In FIG. 6, the bias voltage of the X electrode is maintained at the Ve voltage while the first scan group and the second scan group are addressed, and the bias voltage of the X electrode is lowered to the Ve2 voltage before addressing the third scan group. In this way, the type of bias voltage of the X electrode is reduced, so that the number of power supplies can be reduced.

Meanwhile, in the first to third embodiments of the present invention, the voltage before the scan voltage pulse is applied to each group and the scan voltage are the same, but the two voltage values may be set differently.

In addition, the scan voltage difference between each scan group, that is, the voltage difference between VscL1 and VscL2 and the voltage difference between VscL2 and VscL3 can be set differently.

In addition, the voltage difference may be set differently for each subfield, and may be set differently for each scan group and subfield.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited thereto, and various other changes and modifications are possible.

As described above, according to the present invention, when the scan voltage is sequentially applied to the Y electrode, the Y electrode is divided into a plurality of groups according to the scanning order, and the scan voltage is set differently for each group, and the first Y electrode of each group The address discharge efficiency can be increased by restoring the state of the discharge cell before applying the scan voltage to the state immediately after the reset by further including a period of gradually lowering the voltage of the Y electrode before applying the scan voltage to.

In addition, when the voltage of the Y electrode is gradually lowered during the address period, the bias voltage of the X electrode is also lowered to compensate for the voltage difference between the X and Y electrodes, thereby preventing the occurrence of erroneous discharge in the sustain period.

1 is a partial perspective view of a plasma display device.

2 is a driving waveform diagram of a plasma display device according to the prior art.

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

4 is a driving waveform diagram applied to a plasma display panel according to a first exemplary embodiment of the present invention.

5 is a driving waveform diagram applied to a plasma display panel according to a second exemplary embodiment of the present invention.

6 is a driving waveform diagram applied to a plasma display panel according to a third exemplary embodiment of the present invention.

Claims (13)

In the driving method of a plasma display device comprising a plurality of first electrodes, second electrodes and address electrodes, Dividing the plurality of first electrodes into a plurality of groups including a first group and a second group, In the address period, a) sequentially applying a scan pulse of a second voltage level to a first electrode belonging to the first group while biasing the voltage of the second electrode to a first voltage; b) gradually lowering the voltage of the first electrode to a third voltage; And c) scanning pulses of a fifth voltage level lower than the second voltage level are sequentially applied to a first electrode belonging to the second group while biasing the voltage of the second electrode to a fourth voltage lower than the first voltage; Authorizing step Method of driving a plasma display device comprising a. The method of claim 1, In step b), Biasing the voltage of the second electrode to the fourth voltage A method of driving a plasma display device. The method of claim 1, In step b), Gradually lowering the voltage of the first electrode from the second voltage to the third voltage A method of driving a plasma display device. The method of claim 1, The third voltage and the fifth voltage are substantially equal A method of driving a plasma display device. The method according to claim 1 or 4, The voltage difference between the first voltage and the second voltage and the voltage difference between the fourth voltage and the fifth voltage are substantially the same. A method of driving a plasma display device. The method of claim 1, The plurality of groups further comprises a third group, After step c), d) gradually lowering the voltage of the first electrode to a seventh voltage; And e) scanning pulses of an eighth voltage level lower than the fifth voltage level are sequentially applied to a first electrode belonging to the third group while biasing the voltage of the second electrode to a sixth voltage lower than the fourth voltage; Authorizing step The driving method of the plasma display device further comprising. The method of claim 6, The seventh voltage and the eighth voltage are substantially the same. A method of driving a plasma display device. The method of claim 6, The voltage difference between the first voltage and the second voltage and the voltage difference between the sixth and eighth voltages are substantially the same. A method of driving a plasma display device. In the driving method of a plasma display device comprising a plurality of first electrodes, second electrodes and address electrodes, Dividing the plurality of first electrodes into a plurality of groups including a first group, a second group, and a third group, In the address period, a) sequentially applying a scan pulse of a second voltage level to a first electrode belonging to the first group while biasing the voltage of the second electrode to a first voltage; b) gradually lowering the voltage of the first electrode to the third voltage while biasing the voltage of the second electrode to the first voltage; c) sequentially applying a scan pulse of a fourth voltage level lower than the second voltage level to a first electrode belonging to the second group; d) gradually lowering the voltage of the first electrode to a fifth voltage; And e) scanning pulses of a seventh voltage level lower than the fourth voltage level are sequentially applied to the first electrodes belonging to the third group while biasing the voltage of the second electrode to a sixth voltage lower than the first voltage; Authorizing step Method of driving a plasma display device comprising a. The method of claim 9, In step d), Biasing the voltage of the second electrode to the sixth voltage A method of driving a plasma display device. The method of claim 9, In step b), the voltage of the first electrode is gradually lowered from the second voltage to the third voltage, In step d), the voltage of the first electrode is gradually lowered from the third voltage to the fifth voltage. A method of driving a plasma display device. The method of claim 9, The third voltage and the fourth voltage are substantially the same, and the fifth voltage and the seventh voltage are substantially the same. A method of driving a plasma display device. The method of claim 9 or 12, The voltage difference between the first voltage and the fourth voltage and the voltage difference between the sixth voltage and the seventh voltage are substantially the same. A method of driving a plasma display device.