KR20100060112A - Plasma display apparatus - Google Patents

Abstract

PURPOSE: A plasma display apparatus is provided to stabilize a reset discharge by controlling the number of reset signals and the voltage of a free reset signal. CONSTITUTION: A plasma display panel comprises a scan electrode and a sustain electrode which are parallel. A driving unit differentiates voltage difference between the scan electrode and the sustain electrode at a free reset period of two arbitrary subfields. Two arbitrary subfields are a first sub field and a second sub field. The first and second sub fields are respectively included in different frames.

Description

Plasma Display Apparatus {Plasma Display Apparatus}

The present invention relates to a plasma display device.

The plasma display apparatus includes a plasma display panel.

The plasma display panel includes a phosphor layer formed in a discharge cell divided by a partition wall, and also includes a plurality of electrodes.

When the drive signal is supplied to the electrode of the plasma display panel, the discharge is generated by the drive signal supplied in the discharge cell. Here, when discharged by a drive signal in the discharge cell, the discharge gas filled in the discharge cell generates vacuum ultraviolet rays, and the vacuum ultraviolet light emits the phosphor formed in the discharge cell to emit visible light. Generate. The visible light displays an image on the screen of the plasma display panel.

The present invention provides a plasma display apparatus for stabilizing reset discharge by adjusting the voltage of a pre-reset signal supplied in a pre-reset period or by adjusting the number of reset signals supplied in a reset period according to a pattern of input image data. There is this.

The plasma display device according to the present invention is a plasma display panel including scan electrodes and sustain electrodes parallel to each other, and a scan electrode in a pre-reset period before a reset period of any two subfields among a plurality of subfields. And a driver for differentiating a voltage difference between the sustain electrode and the sustain electrode.

In addition, when any two subfields are referred to as a first subfield and a second subfield, the driving unit may change the maximum voltage difference between the scan electrode and the sustain electrode in the pre-reset period of the first subfield and the second subfield. can do.

In addition, the first subfield and the second subfield may be included in different frames, and may be the first subfield in each frame.

Further, in the pre-reset periods of the first subfield and the second subfield, a first signal in which the voltage gradually decreases is supplied to the scan electrode, a second signal having a reverse polarity with the first signal is supplied to the sustain electrode, and The difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of one subfield is the difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of the second subfield. Can be different from.

Further, the difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of the first subfield is the maximum voltage of the first signal and the maximum of the second signal in the pre-reset period of the second subfield. Larger than the difference in voltage, the first subfield may be repeated at a predetermined period.

In addition, the number of first subfields may be smaller than the number of second subfields.

The difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of the first subfield is called the first voltage, and the lowest voltage of the first signal in the pre-reset period of the second subfield. When the difference between the maximum voltage of the second signal and the second voltage is a second voltage smaller than the first voltage, it is determined whether the pattern of the input image data is switched mode or the holding mode in which the pattern of the input image data is maintained. Image data according to one subfield and image data according to a second subfield may be selectively used.

In addition, the image data according to the first subfield may be used in the switching mode, and the image data according to the second subfield may be used in the maintenance mode.

In addition, the number of reset signals supplied to the scan electrodes in the reset period of the first subfield may be different from the number of reset signals supplied to the scan electrodes in the reset period of the second subfield.

Further, the maximum voltage difference between the scan electrode and the sustain electrode in the pre-reset period of the first subfield is greater than the maximum voltage difference between the scan electrode and the sustain electrode in the pre-reset period of the second subfield, and reset of the first subfield. The number of reset signals supplied to the scan electrodes in the period may be greater than the number of reset signals supplied to the scan electrodes in the reset period of the second subfield.

Another plasma display apparatus according to the present invention is a plasma display panel including scan electrodes and sustain electrodes parallel to each other and a scan electrode in a pre-reset period before a reset period of at least one subfield of a first frame among a plurality of frames. The pre-reset signal is supplied such that the voltage difference between the sustain electrode and the sustain electrode becomes the first voltage, and the voltage difference between the scan electrode and the sustain electrode is greater than the first voltage in the pre-reset period before the reset period of at least one subfield of the second frame. The driving unit may be configured to supply a pre-reset signal so as to have a small second voltage, and the image data according to the first frame and the image data according to the second frame may be selectively used depending on whether the pattern of the input image data is switched.

In addition, when the pattern of the input image data is switched mode, the image data according to the first frame may be used, and when the pattern of the input image data is maintained, the image data according to the second frame may be used. .

In addition, the pre-reset signal supplied in the pre-reset period before the reset period of the at least one subfield of the first frame is a first signal in which the voltage gradually drops when supplied to the scan electrode, and is supplied to the sustain electrode and supplied to the first signal. And a second signal having reverse polarity, wherein the pre-reset signal supplied in the pre-reset period before the reset period of the at least one subfield of the second frame is provided with a third signal in which the voltage gradually decreases when supplied to the scan electrode. And a fourth signal supplied to the sustain electrode and inverse polarity with the third signal, wherein the lowest voltage of the first signal may be lower than the lowest voltage of the second signal.

In addition, the lowest voltage of the first signal may be the same as the lowest voltage of the scan signal supplied to the scan electrode in the address period after the reset period.

Another plasma display device according to the present invention is a plasma display panel including scan electrodes and a sustain electrode that are parallel to each other, and a scan electrode in any two reset periods of a plurality of subfields depending on whether a pattern of input image data is switched. It may include a driving unit for varying the number of reset signals supplied.

In addition, when any two subfields are referred to as a first subfield and a second subfield, the first subfield and the second subfield may be included in different frames, and may be the first subfield in each frame.

In addition, any two subfields are referred to as a first subfield and a second subfield, and the number of reset signals supplied to the scan electrodes in the reset period of the first subfield is transferred to the scan electrodes in the reset period of the second subfield. When the number of reset signals supplied is greater than the number of reset signals supplied, the image data according to the first subfield is used in the switching mode in which the pattern of the input image data is switched, and the second subfield in the holding mode in which the pattern of the input image data is maintained. Can use the image data according to.

The number of reset signals supplied to the scan electrodes in the reset period of the first subfield may be two, and the number of reset signals supplied to the scan electrodes in the reset period of the second subfield may be one.

The plasma display apparatus according to the present invention stabilizes the reset discharge by adjusting the voltage of the pre-reset signal supplied in the pre-reset period or the number of reset signals supplied in the reset period in accordance with the pattern of the input image data. It has the effect of improving the margin.

Hereinafter, a method of driving a plasma display panel according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram for explaining a configuration of a plasma display device.

Referring to FIG. 1, the plasma display apparatus may include a plasma display panel 100 and a driver 110.

The plasma display panel 100 may include scan electrodes Y1 to Yn and sustain electrodes Z1 to Zn that are parallel to each other, and may include address electrodes X1 to Xm that cross the scan electrode and the sustain electrode. In addition, the plasma display panel 100 may implement an image in a frame including a plurality of subfields.

The driver 110 may supply a driving signal to at least one of a scan electrode, a sustain electrode, and an address electrode of the plasma display panel 100 to implement an image on the screen of the plasma display panel 100. Preferably, the driving unit 110 is a voltage difference between the scan electrode and the sustain electrode of the plasma display panel 100 in the pre-reset period before the reset period of any two sub-fields of the plurality of sub-fields (Sub-Field) Can be different.

Here, in FIG. 1, only the case in which the driving unit 110 is formed as one board is illustrated, but in the present invention, the driving unit 110 is divided into a plurality of boards according to electrodes formed on the plasma display panel 100. It is also possible to lose. For example, the driver 110 may include a first driver (not shown) for driving the scan electrode of the plasma display panel 100, a second driver for driving the sustain electrode, and a third driver (not shown) for driving the address electrode. Can be divided into

2 is a diagram for explaining the structure of a plasma display panel.

Referring to FIG. 2, the plasma display panel 100 includes a front substrate 201 in which scan electrodes 202 and Y and sustain electrodes 203 and Z are parallel to each other, and scan electrodes 202 and Y and a sustain electrode ( The back substrate 211 on which the address electrodes 213 and X intersect with 203 and Z may be formed.

On the front substrate 201 where the scan electrodes 202 and Y and the sustain electrodes 203 and Z are formed, the discharge currents of the scan electrodes 202 and Y and the sustain electrodes 203 and Z are limited and the scan electrodes 202 and Y are restricted. ) And an upper dielectric layer 204 may be arranged to insulate between the sustain electrodes 203 and Z.

A protective layer 205 may be formed on the front substrate 201 where the upper dielectric layer 204 is formed to facilitate discharge conditions. The protective layer 205 may include a material having a high secondary electron emission coefficient, such as magnesium oxide (MgO) material.

The address electrodes 213 and X are formed on the rear substrate 211, and the address electrodes 213 and X are covered on the upper side of the rear substrate 211 on which the address electrodes 213 and X are formed. A lower dielectric layer 215 may be formed that insulates X).

On top of the lower dielectric layer 215, a partition 212, such as a stripe type, a well type, a delta type, a honeycomb type, etc., for partitioning a discharge space, that is, a discharge cell, is formed. This can be formed. Accordingly, the first discharge cell emitting red (R) light, the second discharge cell emitting blue (B) light, and the green (Green) light between the front substrate 201 and the rear substrate 211. : G) A third discharge cell or the like that emits light can be formed.

The partition 212 may include a first partition 212b and a second partition 212a, and a height of the first partition 212b and a height of the second partition 212a may be different from each other.

In the discharge cell, the address electrode 213 may cross the scan electrode 202 and the sustain electrode 203. That is, the discharge cell is formed at the point where the address electrode 213 crosses the scan electrode 202 and the sustain electrode 203.

A predetermined discharge gas may be filled in the discharge cell partitioned by the partition wall 212.

In addition, a phosphor layer 214 that emits visible light for image display may be formed in the discharge cells partitioned by the partition wall 212. For example, a first phosphor layer that generates red light, a second phosphor layer that generates blue light, and a third phosphor layer that generates green light may be formed.

In addition, the address electrode 213 formed on the rear substrate 211 may have substantially the same width or thickness, but the width or thickness inside the discharge cell may be different from the width or thickness outside the discharge cell. . For example, the width or thickness inside the discharge cell may be wider or thicker than that outside the discharge cell.

When a predetermined signal is supplied to at least one of the scan electrode 202, the sustain electrode 203, and the address electrode 213, discharge may occur in the discharge cell. As such, when discharge is generated in the discharge cell, ultraviolet rays may be generated by the discharge gas filled in the discharge cell, and the ultraviolet rays may be irradiated onto the phosphor particles of the phosphor layer 214. Then, a predetermined image may be displayed on the screen of the plasma display panel 100 by the phosphor particles irradiated with ultraviolet rays to emit visible light.

FIG. 3 is a diagram for describing an image frame for implementing gradation of an image.

Referring to FIG. 3, a frame for implementing gray levels of an image may include a plurality of subfields SF1 to SF8.

In addition, the plurality of subfields may include a sustain period for implementing gradation according to an address period and a number of discharges for selecting discharge cells in which discharge cells will not occur or discharge cells in which discharge occurs. Period) may be included.

For example, in case of displaying an image with 256 gray levels, for example, one frame is divided into eight subfields SF1 to SF8 as shown in FIG. 3, and each of the eight subfields SF1 to SF8 is an address. It can include a period and a sustain period.

Alternatively, at least one subfield of the plurality of subfields of the frame may further include a reset period for initialization.

In addition, at least one subfield of the plurality of subfields of the frame may not include a sustain period.

Meanwhile, the weight of the corresponding subfield may be set by adjusting the number of sustain signals supplied in the sustain period. That is, a predetermined weight can be given to each subfield using the sustain period. For example, the weight of each subfield is 2 ⁿ by setting the weight of the first subfield to 2 ⁰ and the weight of the second subfield to 2 ¹ (where n = 0, 1, 2, 3, 4, 5, 6, 7) can be set to increase the ratio. As described above, gray levels of various images may be realized by adjusting the number of sustain signals supplied in the sustain period of each subfield according to the weight in each subfield.

In FIG. 3, only one image frame is composed of eight subfields. However, the number of subfields constituting one image frame may be variously changed. For example, one video frame may be configured with 12 subfields from the first subfield to the twelfth subfield, or one video frame may be configured with 10 subfields.

In addition, in FIG. 3, subfields are arranged in an order of increasing weight in one image frame. Alternatively, subfields may be arranged in an order of decreasing weight in one image frame. Subfields may be arranged regardless.

At least one of the plurality of subfields included in the frame may be a selective erase subfield (SE), and at least one of the plurality of subfields may be a selective write subfield (SW). Do.

If one frame includes at least one selective erase subfield and an optional write subfield, the first subfield or the first and second subfields of the plurality of subfields of the frame are the selective write subfields, It may be desirable for the remainder to be selective erasure subfields.

Here, the selective erasing subfield is a subfield that turns off the discharge cells supplied with the data signal Data to the address electrodes in the address period in the sustain period after the address period.

The selective erasure subfield may include an address period for selecting a discharge cell to be turned off and a sustain period for generating sustain discharge in discharge cells not selected in the address period.

The selective write subfield is a subfield that turns on the discharge cells supplied with the data signal Data to the address electrodes in the address period in the sustain period after the address period.

The selective write subfield may include a reset period for initializing the discharge cells, an address period for selecting the discharge cells to be turned on, and a sustain period for generating sustain discharge in the discharge cells selected in the address period.

4 is a diagram schematically illustrating a method of driving a plasma display device. The driving waveform to be described below is supplied by the driving unit 110 of FIG. 1.

Referring to FIG. 4, a voltage is gradually applied to the scan electrode Y in the pre-reset period PRS before the reset period RS of at least one subfield of the plurality of sub-fields of the frame. The falling first signal S1 may be supplied.

In addition, in the pre-reset period, the second signal S2 having a reverse polarity with the first signal S1 can be supplied to the sustain electrode Z.

In this pre-reset period, when the first signal S1 is supplied to the scan electrode and the second signal S2 overlapping the first signal S1 is supplied to the sustain electrode, a pre-set discharge occurs in the discharge cell. . Then, a wall charge of a level sufficiently usable in a subsequent reset period may be formed in the discharge cell.

In the reset period RP for initialization, the reset signal RS may be supplied to the scan electrode Y. Here, the reset signal RS may include a rising ramp signal (Ramp-Up: RU) in which the voltage gradually rises and a falling ramp signal (Ramp-Down: RD) in which the voltage gradually falls.

For example, the rising ramp signal RU may be supplied to the scan electrode in the setup period SU of the reset period, and the falling ramp signal RD may be supplied to the scan electrode in the setdown period SD after the setup period. .

When the rising ramp signal is supplied to the scan electrode, a weak dark discharge, that is, setup discharge, occurs in the discharge cell by the rising ramp signal. By this setup discharge, the distribution of wall charges can be uniform in the discharge cells.

After the rising ramp signal is supplied, when the falling ramp signal is supplied to the scan electrode, a weak erase discharge, that is, a setdown discharge occurs in the discharge cell. By this set-down discharge, wall charges such that address discharge can be stably generated can be uniformly retained in the discharge cells.

In the address period AP after the reset period, the scan reference signal Ybias having a voltage higher than the lowest voltage of the falling ramp signal may be supplied to the scan electrode.

In addition, in the address period, the scan signal Sc that falls from the voltage of the scan reference signal Ybias may be supplied to the scan electrode.

Meanwhile, the pulse width of the scan signal supplied to the scan electrode in the address period of at least one subfield may be different from the pulse width of the scan signal of another subfield. For example, the width of the scan signal in the subfield located later in time may be smaller than the width of the scan signal in the preceding subfield. In addition, the reduction of the scan signal width according to the arrangement order of the subfields can be made gradually, such as 2.6 Hz (microseconds), 2.3 Hz, 2.1 Hz, 1.9 Hz, or 2.6 Hz, 2.3 Hz, 2.3 Hz, 2.1 Hz. .... 1.9 ㎲, 1.9 ㎲ and so on.

As such, when the scan signal is supplied to the scan electrode, the data signal Dt may be supplied to the address electrode X corresponding to the scan signal.

When the scan signal and the data signal are supplied, an address discharge may be generated in the discharge cell to which the data signal is supplied while the voltage difference between the scan signal and the data signal and the wall voltage generated by the wall charges generated in the reset period are added. .

In addition, the sustain reference signal Zbias signal may be supplied to the sustain electrode in the address period in which the address discharge occurs so that the address discharge is effectively generated between the scan electrode and the address electrode.

In the sustain period SP after the address period, the sustain signal SUS may be supplied to at least one of the scan electrode and the sustain electrode. For example, a sustain signal may be alternately supplied to the scan electrode and the sustain electrode.

When such a sustain signal is supplied, the discharge cell selected by the address discharge is added with the wall voltage in the discharge cell and the sustain voltage Vs of the sustain signal, and a sustain discharge, i.e., display between the scan electrode and the sustain electrode when the sustain signal is supplied. Discharge may occur.

In this way, an image can be realized.

5 to 9 are drawings for explaining a method of driving the plasma display device in detail.

First, referring to FIG. 5, the voltage difference between the scan electrode and the sustain electrode in the pre-reset period PRS before the reset period RS of any two subfields of the plurality of subfields is different from each other. Preferably. The maximum voltage difference between the scan electrode and the sustain electrode in the pre-reset period of any two subfields may be different.

For example, as shown in FIG. 5, the first subfield SF1 of the first frame Frame1 includes a pre-reset period before the reset period, and the first subfield SF1 of the second frame Frame2. In addition, when the pre-reset period is included, the voltage difference between the scan electrode Y and the sustain electrode Z in the pre-reset period of the first subfield of the first frame is equal to the pre-reset period of the first subfield of the second frame. It may be greater than the voltage difference between the scan electrode and the sustain electrode in.

In detail, as shown in FIG. 6A, a pre-reset signal supplied in the pre-reset period of the first subfield of the first frame is supplied to the scan electrode, and is supplied to the first signal S1 and the sustain electrode of which the voltage gradually decreases. In the case of including the second signal S2 having the opposite polarity with the first signal S1, the difference between the lowest voltage Vs1 of the first signal S1 and the maximum voltage Vs2 of the second signal S2 The difference between the lowest voltage Vs1 of the first signal S1 and the maximum voltage Vs2 of the second signal S2 supplied in the pre-reset period of the first subfield of the second frame of B is different.

To this end, the lowest voltage Vs1 of the first signal S1 supplied to the scan electrode in the pre-reset period of the first subfield of the first frame as in A is pre-set in the first subfield of the second frame as in B. In the reset period, the voltage may be lower than the lowest voltage Vs1 of the first signal S1 supplied to the scan electrode. That is, the voltage difference between the scan electrode and the sustain electrode can be increased by lowering the lowest voltage Vs1 of the first signal S1 supplied to the scan electrode in the pre-reset period of the first subfield of the first frame.

6, the lowest voltage Vs1 of the first signal S1 supplied to the scan electrode in the pre-reset period of the first subfield of the first frame is scanned in the address period as shown in FIG. 7A. It may be substantially the same as the lowest voltage (-Vy) of the scan signal Sc supplied to the electrode. In addition, the lowest voltage Vs1 of the first signal S1 supplied to the scan electrode in the pre-reset period of the first subfield of the second frame is reset to be supplied to the scan electrode in the reset period as shown in FIG. It may be substantially equal to the lowest voltage of the lowest voltage (V _RD ) of the signal.

Alternatively, as shown in FIG. 8A, the maximum voltage Vs2 of the second signal S2 supplied to the sustain electrode in the pre-reset period of the first subfield of the first frame is represented by B as the first subfield of the second frame. It can be higher than the maximum voltage (Vs2) of the second signal (S2) supplied to the sustain electrode in the pre-reset period of. That is, by increasing the maximum voltage Vs2 of the second signal S2 supplied to the scan electrode in the pre-reset period of the first subfield of the first frame, the voltage difference between the scan electrode and the sustain electrode can be increased. .

In this case, as in A, the maximum voltage Vs2 of the second signal S2 supplied to the sustain electrode in the pre-reset period of the first subfield of the first frame is equal to that of the sustain signal SUS supplied in the subsequent sustain period. It may be substantially equal to or higher than the voltage Vs. In addition, the maximum voltage Vs2 of the second signal S2 supplied to the sustain electrode in the pre-reset period of the first subfield of the second frame is greater than the maximum voltage of the sustain signal SUS supplied in the subsequent sustain period. It may be lower or substantially the same. Here, when the maximum voltage Vs2 of the second signal S2 supplied to the sustain electrode in the pre-reset period of the first subfield of the second frame is lower than the voltage Vs of the sustain signal, the second signal S2. The maximum voltage Vs2 may be substantially the same as the voltage of the sustain reference signal supplied to the sustain electrode in the address period.

Meanwhile, the number of subfields including the pre-reset period among the plurality of subfields included in one frame may be variously changed. For example, it may be possible that all subfields in one frame include a pre-reset period.

Considering a margin for the driving time, it may be desirable to limit the number of subfields including the pre-reset period among a plurality of subfields of one frame.

As such, when the voltage difference between the scan electrode and the sustain electrode in the pre-reset period is different from each other in any two subfields, as shown in FIG. 5, the scan electrode and the pre-reset period in the first subfield of the first frame are different from each other. Since the voltage difference between the sustain electrodes is relatively large, a relatively large amount of charges may be formed in the pre-reset period.

Then, the reset discharge is more strongly and stably generated in the subsequent reset period, thereby making the wall charges of the discharge cells uniform. Accordingly, the driving margin can be increased.

In addition, in the first subfield of the second frame as in the case of FIG. 5, since the voltage difference between the scan electrode and the sustain electrode is relatively small in the pre-reset period, the visible light generated by the pre-reset discharge generated in the pre-reset period is reduced. The amount can be reduced. Accordingly, it may be possible to improve the image quality of the image to be implemented.

On the other hand, if the voltage difference between the scan electrode and the sustain electrode in the pre-reset period is relatively large in all subfields including the pre-reset period as in the first subfield of the first frame of FIG. 5, the reset after the pre-reset period is performed. It is possible to improve the driving margin by stabilizing the reset discharge generated in the period, but the contrast characteristic of the image to be implemented may be excessively lowered by the rapid increase in the amount of light generated in the pre-reset period.

In addition, if the voltage difference between the scan electrode and the sustain electrode in the pre-reset period is relatively small in all subfields including the pre-reset period as in the first subfield of the second frame of FIG. It is possible to improve the contrast characteristic of the image by reducing the amount of light, but the intensity and stability of the reset discharge occurring in the subsequent reset period may be deteriorated by the decrease of the amount of wall charges formed in the discharge cell in the pre-reset period. As a result, the driving margin may deteriorate.

On the other hand, in the present invention, as in the case of FIG. 5, the voltage difference between the scan electrode and the sustain electrode is relatively large in the first subfield of the first frame during the pre-reset period, and pre-reset in the first subfield of the second frame. By relatively reducing the voltage difference between the scan electrode and the sustain electrode in the period, it is possible to stabilize the reset discharge to improve the driving margin and to improve the contrast characteristic of the image.

In addition, any two subfields having different voltage differences between the scan electrode and the sustain electrode in the pre-reset period may be repeated at regular intervals. Preferably, as in the first subfield of the first frame of FIG. 5, a subfield having a relatively large voltage difference between the scan electrode and the sustain electrode in the pre-reset period may be repeated every certain period.

In addition, as the subfields having a relatively large voltage difference between the scan electrode and the sustain electrode are repeated every predetermined period in the pre-reset period, the number is the number of subfields having a relatively small voltage difference between the scan electrode and the sustain electrode during the pre-reset period. Can be less than.

For example, as in the case of FIG. 9, the voltage difference between the scan electrode and the sustain electrode is relatively large in the pre-reset period of the first subfield as in the first frame of FIG. As in the second frame of 5, the voltage difference between the scan electrode and the sustain electrode may be relatively small in the pre-reset period of the first subfield.

That is, one subfield having a relatively large voltage difference between the scan electrode and the sustain electrode may be inserted in the pre-reset period at intervals of 10 frames.

If, as in the first subfield of the first frame of FIG. 5, the number of subfields in which the voltage difference between the scan electrode and the sustain electrode is relatively large in the prereset period is excessively increased, the scan electrode and the sustain electrode in the prereset period are increased. Visible light generated in the pre-reset period when the number of subfields with a relatively large voltage difference between them becomes larger or substantially the same as the number of subfields with a smaller voltage difference between the scan electrode and the sustain electrode in the pre-reset period. The excessive amount of lines can deteriorate the contrast characteristics of the image.

10 is a view for explaining an example of a method of adjusting the number of reset signals. Hereinafter, the description of the contents described above in detail will be omitted.

Referring to FIG. 10, the number of reset signals RS supplied to the scan electrodes in the reset period of two arbitrary subfields may be different.

For example, as in the case of FIG. 10, the number of reset signals RS1 and RS2 supplied to the scan electrodes in the reset period of the first subfield SF1 of the first frame Frame1 is two, and the second frame Frame2 is provided. The number of reset signals supplied to the scan electrodes in the reset period of the first subfield SF2 may be one.

In addition, in the first subfield of the first frame having a relatively large number of reset signals, as shown in the first subfield of the first frame of FIG. 5, the voltage difference between the scan electrode and the sustain electrode is different in the pre-reset period before the reset period. Can be relatively large.

As described above, when a plurality of reset signals are supplied in the reset period of the subfield where the voltage difference between the scan electrode and the sustain electrode is relatively large in the pre-reset period, the reset discharge can be further stabilized and the driving margin can be further improved. .

In addition, when a plurality of reset signals are used in the reset period, even when the amount of wall charges formed in the discharge cells in the pre-reset period before the reset period is small, the reset discharge can be stabilized and the driving margin can be sufficiently improved.

On the other hand, when the number of reset signals supplied to the scan electrodes in the reset period is three or more, the improvement in driving margin is insignificant compared to when the number of reset signals is two, whereas the amount of visible light generated in the reset period is greatly increased. Therefore, the contrast characteristic may deteriorate.

Therefore, it may be desirable to determine the maximum number of reset signals at a level capable of improving the driving margin without deteriorating the contrast characteristic. To this end, the maximum number of reset signals supplied to the scan electrodes in the reset period may be two. That is, the number of reset signals supplied to the scan electrodes in the reset period of the subfield where the voltage difference between the scan electrode and the sustain electrode is relatively large in the pre-reset period is two, and the voltage difference between the scan electrodes and the sustain electrode in the pre-reset period is In the reset period of the relatively small subfield, the number of reset signals supplied to the scan electrodes is one.

11 to 12 are diagrams for explaining an example of the driving method according to the pattern switching of the image data. In the following, the description thereof will be omitted.

First, referring to FIG. 11, the voltage difference between the scan electrode and the sustain electrode may be differently adjusted in the pre-reset period depending on whether the pattern of the input image data is switched.

For example, as shown in FIG. 5, in the pre-reset period before the reset period of the first subfield of the first frame among the plurality of frames, the pre-reset is performed such that the voltage difference between the scan electrode and the sustain electrode becomes the first voltage V1. A pre-reset signal such that a signal is supplied and the voltage difference between the scan electrode and the sustain electrode becomes a second voltage V2 smaller than the first voltage V1 in the pre-reset period before the reset period of the second subfield of the second frame. Suppose we supply

In this case, the image data according to the first frame and the image data according to the second frame may be selectively used depending on whether the pattern of the input image data is switched.

Preferably, when the pattern of the input image data is switched, the image data according to the first frame having a relatively large voltage difference between the scan electrode and the sustain electrode is used in the pre-reset period, and the pattern of the input image data is switched. If not, the image data according to the second frame having a relatively small voltage difference between the scan electrode and the sustain electrode in the pre-reset period can be used.

For example, suppose that the pattern of the image data input at time t10 and time t20 is switched as in the case of FIG. 11.

In this case, at t10 and t20, the image data according to the first frame having a relatively large voltage difference between the scan electrode and the sustain electrode in the pre-reset period may be used.

When the pattern of the input image data is switched, it may mean that two consecutive frames implement a substantially heterogeneous image when the pattern of the image data is switched. This may mean that the distribution of wall charges in two consecutive frames is heterogeneous, and thus, a stronger and more reliable reset may be necessary to smoothly implement heterogeneous images.

Therefore, when the pattern of image data is switched at time t10 and t20, the image data according to the first frame having a relatively large voltage difference between the scan electrode and the sustain electrode in the pre-reset period is used in advance in the pre-reset period before the reset period. By forming a sufficiently large amount of wall charge, the reset discharge in the reset period is sufficiently stable and strong. In this case, the driving margin can be improved.

On the other hand, when the pattern of the image data does not change and the substantially same pattern is maintained, since the images having substantially similar characteristics may be continuously implemented, the reset discharge may be sufficiently reset even when the reset discharge is relatively weak.

Therefore, when the pattern of the image data is substantially maintained, the image data according to the second frame having a relatively small voltage difference between the scan electrode and the sustain electrode in the pre-reset period can be used.

If the pattern of the image data is substantially maintained, if the image data according to the first frame having a relatively large voltage difference between the scan electrode and the sustain electrode is used in the pre-reset period, the driving margin may be improved, but the improvement is achieved. The degree can be insignificant, and unnecessarily increasing the amount of visible light generated in the pre-reset period can deteriorate the contrast characteristic of the image.

Meanwhile, the image data according to the first frame and the image data according to the second frame may be selectively used according to the switching period of the input image data pattern.

For example, as shown in FIG. 11, when the pattern of the image data is switched at time t10 and the image data to which the pattern is converted is input in the P1 period, the P1 period is referred to as a switching mode, and the pattern of the image data is substantially changed. The P2 period held by is referred to as the sustain mode.

Here, in the switching mode, the image data according to the first frame having a relatively large voltage difference between the scan electrode and the sustain electrode in the pre-reset period is used, and in the maintenance mode, the voltage difference between the scan electrode and the sustain electrode is relatively in the pre-reset period. Image data according to the small second frame can be used.

Here, whether or not the pattern of the image data is switched may be divided by the amount of change of the data of two consecutive frames.

For example, when the first frame and the second frame are continuous with each other, and the data of the first frame and the data of the second frame are substantially different, the images of the first frame and the second frame are substantially different, and the second The frame may be said that the image data has been converted.

Alternatively, the image data of the second frame may be switched when the amount of change of the image data of the second frame exceeds the threshold amount of change based on the image data of the first frame. For example, when the threshold change amount is set to approximately 50%, and the ratio of the portion of the second frame that is different from the image data of the first frame exceeds 50%, the image data of the second frame may be converted.

Alternatively, it may be possible to determine whether to switch the image data according to the degree of change of the average power level APL. For example, when the difference between the average power level of the second frame and the average power level of the first frame before the second frame exceeds a preset threshold, the image data of the second frame may be switched.

Preferably, when the image data is image data according to a moving picture, the current mode is set to a telephone mode to relatively increase the voltage difference between the scan electrode and the sustain electrode in the pre-reset period, and the image data is an image according to a still image. In the case of data, it can be set to the sustain mode to relatively reduce the voltage difference between the scan electrode and the sustain electrode in the pre-reset period.

In a more strict setting method, when the image data of consecutive first and second frames is substantially the same, the operation mode is maintained, and the image data of the first and second frames is not substantially the same. Can operate in the switch mode. Here, although the image data of the first frame and the second frame is the same, even if the image data of the first frame or the second frame is slightly changed due to a noise or the like, the image data of the first frame and the second frame is substantially changed. Can be regarded as the same.

In addition, it is possible to operate in the maintenance mode when the average power levels of the consecutive first and second frames are the same, and to operate in the switching mode when the average power levels of the first and second frames are different.

Meanwhile, the switching operation of the viewing channel and the on operation of power may be excluded from the switching mode of the image data.

The switching operation, the power-on operation, and the like of the viewing channel are operations for implementing an image discontinuously, and there is enough time for the timing of each operation.

On the other hand, when image data according to a video is input in the process of continuously implementing images, frames are continuously input without a pause period in which an image is not displayed, such as a switching operation of a viewing channel. It is desirable to operate in the switching mode as in the present invention to improve the drive margin.

Alternatively, as in the case of FIG. 12, the number of reset signals supplied to the scan electrodes in the reset period may be differently adjusted depending on whether the pattern of the input image data is switched.

Preferably, in the switching mode P1, the plurality of reset signals RS1 and RS2 may be supplied to the scan electrodes in the reset period, and in the sustain mode P2, one reset signal may be supplied to the scan electrodes in the reset period.

As described above, when the number of reset signals supplied to the scan electrodes is increased in the switching mode P1, the driving margin may be prevented even if the pattern of the input image data is switched.

Alternatively, as shown in FIG. 11, while the voltage difference between the scan electrode and the sustain electrode is relatively large in the pre-reset period in the switching mode P1, the reset supplied in the reset period in the telephone mode P1 as in the case of FIG. 12. It is also possible to have a plurality of signals. That is, it is possible to merge the method of FIG. 11 and the method of FIG.

As such, the technical configuration of the present invention described above can be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the exemplary embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the foregoing detailed description, and the meaning and scope of the claims are as follows. And all changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

1 is a diagram for explaining the configuration of a plasma display device;

2 is a diagram for explaining the structure of a plasma display panel;

FIG. 3 is a diagram for explaining a frame for implementing gradation of an image. FIG.

4 is a view for schematically explaining a method of driving a plasma display device;

5 to 9 are views for explaining a method of driving a plasma display device in detail.

10 is a diagram for explaining an example of a method of adjusting the number of reset signals.

11 to 12 are diagrams for explaining an example of the driving method according to the pattern switching of the image data.

Claims (18)

A plasma display panel including scan electrodes and sustain electrodes parallel to each other; And A driver for differentiating a voltage difference between the scan electrode and the sustain electrode in a pre-reset period before a reset period of any two subfields among a plurality of sub-fields; Plasma display device comprising a. The method of claim 1, When any two subfields are called a first subfield and a second subfield, The driving unit And a maximum voltage difference between the scan electrode and the sustain electrode during the pre-reset period of the first subfield and the second subfield. The method of claim 2, The first subfield and the second subfield are included in different frames and are the first subfield in each frame. 4. The method according to any one of claims 1 to 3, In the pre-reset periods of the first subfield and the second subfield, a first signal of which voltage gradually decreases is supplied to the scan electrode, and a second signal having a reverse polarity with the first signal is supplied to the sustain electrode. Supplied, The difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of the first subfield is equal to the lowest voltage of the first signal in the pre-reset period of the second subfield. And a plasma display device different from the maximum voltage difference of the second signal. The method of claim 4, wherein The difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of the first subfield is equal to the lowest voltage of the first signal in the pre-reset period of the second subfield. Greater than the difference between the maximum voltages of the second signals, And the first subfield is repeated at regular intervals. The method of claim 4, wherein The difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of the first subfield is equal to the lowest voltage of the first signal in the pre-reset period of the second subfield. Greater than the difference between the maximum voltages of the second signals, And the number of the first subfields is less than the number of the second subfields. The method of claim 4, wherein The difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of the first subfield is called a first voltage. When the difference between the lowest voltage of the first signal and the maximum voltage of the second signal in the pre-reset period of the second subfield is a second voltage smaller than the first voltage, The image data according to the first subfield and the image data according to the second subfield may be selectively used depending on whether the pattern of the input image data is switched mode or the maintenance mode in which the pattern of the input image data is maintained. Plasma display device. The method of claim 7, wherein And the image data according to the first subfield is used in the switching mode, and the image data according to the second subfield is used in the holding mode. The method of claim 2, The number of reset signals supplied to the scan electrodes in the reset period of the first subfield and the number of reset signals supplied to the scan electrodes in the reset period of the second subfield are different. The method of claim 9, The maximum voltage difference between the scan electrode and the sustain electrode in the pre-reset period of the first subfield is greater than the maximum voltage difference between the scan electrode and the sustain electrode in the pre-reset period of the second subfield, The number of reset signals supplied to the scan electrodes in the reset period of the first subfield is greater than the number of reset signals supplied to the scan electrodes in the reset period of the second subfield. A plasma display panel including scan electrodes and sustain electrodes parallel to each other; And In the pre-reset period before the reset period of the at least one subfield of the first frame of the plurality of frames, a pre-reset signal is supplied such that the voltage difference between the scan electrode and the sustain electrode becomes the first voltage, and the second A driver configured to supply a pre-reset signal such that a voltage difference between the scan electrode and the sustain electrode becomes a second voltage smaller than the first voltage in the pre-reset period before the reset period of at least one subfield of the frame; Including, And an image data according to the first frame and an image data according to the second frame according to whether the pattern of the input image data is switched. The method of claim 11, Plasma using the image data according to the first frame when the pattern of the input image data is switched, and using the image data according to the second frame when the pattern of the input image data is maintained. Display device. The method of claim 11, The pre-reset signal supplied in the pre-reset period before the reset period of the at least one subfield of the first frame is a first signal in which a voltage gradually decreases when supplied to a scan electrode, and is supplied to a sustain electrode and supplied to the first signal. A second signal that is reverse polarity with The pre-reset signal supplied in the pre-reset period before the reset period of the at least one subfield of the second frame is a third signal of which voltage gradually decreases when supplied to the scan electrode, and is supplied to the sustain electrode and supplied to the third signal. A fourth signal that is reverse polarity with The lowest voltage of the first signal is lower than the lowest voltage of the second signal. The method of claim 13, And the lowest voltage of the first signal is the same as the lowest voltage of the scan signal supplied to the scan electrode in the address period after the reset period. A plasma display panel including scan electrodes and sustain electrodes parallel to each other; And A driver configured to vary the number of reset signals supplied to the scan electrodes in any two reset periods among a plurality of subfields according to whether the pattern of the input image data is switched; Plasma display device comprising a. The method of claim 15, When any two subfields are called a first subfield and a second subfield, The first subfield and the second subfield are included in different frames and are the first subfield in each frame. The method of claim 15, Any two subfields are called a first subfield and a second subfield, When the number of reset signals supplied to the scan electrodes in the reset period of the first subfield is greater than the number of reset signals supplied to the scan electrodes in the reset period of the second subfield, In the switching mode in which the pattern of the input image data is switched, the image data according to the first subfield is used, and in the maintenance mode in which the pattern of the input image data is maintained, the image data according to the second subfield is used. Plasma display device. The method of claim 17, And the number of reset signals supplied to the scan electrodes in the reset period of the first subfield is two, and the number of reset signals supplied to the scan electrodes in the reset period of the second subfield is one.

Images