KR100784568B1 - Plasma Display Apparatus and Driving Method Thereof - Google Patents

Abstract

The present invention relates to a plasma display device and a driving method thereof, and more particularly, to a plasma display device for adjusting a slope of a set-up pulse of a reset pulse supplied to a scan electrode in a reset period according to a pattern of an input image; The present invention relates to a driving method thereof, and has an effect of improving image quality by removing a sticking afterimage.

Plasma display device of the present invention for achieving this purpose is to control the plasma display panel including the scan electrode, the scan driver for driving the scan electrode and the scan driver, at least one of the sub-field of the frame according to the pattern of the input image Subfield Supplied to the scan electrode in the reset period And a reset pulse controller for adjusting a slope of the setup pulse of the reset pulse.

Description

Plasma Display Apparatus and Driving Method Thereof

1 is a diagram showing the structure of a typical plasma display panel.

2 is a view showing a coupling relationship between a plasma display panel and a driver;

3 is a diagram illustrating a method of implementing image gradation of a typical plasma display panel.

4 is a view illustrating a driving waveform according to a driving method of a conventional plasma display panel.

5 is a view for explaining an afterimage generated in a conventional plasma display panel.

6 is a diagram for explaining the structure of a plasma display device of the present invention;

7 is a first embodiment of a method of driving a plasma display panel of the present invention;

8 is a view for explaining in detail the reset pulse of the reset period of the drive waveform of the plasma display panel of the present invention of FIG.

9A to 9B are diagrams for explaining an example in which a plurality of subfields having a plurality of reset pulses supplied to the scan electrode in a reset period are set in plural.

10A to 10B are diagrams for explaining that the number of reset pulses changes as the time for which the image lasts below the threshold change rate increases in the first embodiment of the method of driving the plasma display panel of the present invention.

FIG. 11 is a view for explaining another example in which the number of reset pulses changes as the time for which an image lasts below a threshold change rate increases in the first embodiment of the method of driving a plasma display panel of the present invention. FIG.

Fig. 12 shows a second embodiment of a method of driving a plasma display panel of the present invention.

13A to 13B are diagrams for explaining an example in which a plurality of subfields are set in which the absolute value of the inclination of the set-up pulses supplied to the scan electrodes in the setup period of the reset period is larger than the other subfields.

14A to 14B are diagrams for describing a change in the slope of a set-up pulse as the time for which an image lasts below a threshold change rate increases in the second embodiment of the method of driving a plasma display panel of the present invention. .

FIG. 15 is a view for explaining another example in which a slope of a set-up pulse changes as the time for which an image lasts below a threshold change rate increases in the second embodiment of the method of driving a plasma display panel of the present invention. .

Fig. 16 shows a third embodiment of a method of driving a plasma display panel of the present invention.

17A to 17B are diagrams for explaining an example in which a plurality of subfields are set in which the absolute value of the inclination of the set-down pulses supplied to the scan electrodes in the setdown period of the reset period is larger than the other subfields.

18A to 18B are diagrams for explaining that the slope of a set-down pulse is changed as the time for which an image lasts below a threshold change rate increases in the third embodiment of the method of driving a plasma display panel of the present invention. .

FIG. 19 is a view for explaining another example in which the slope of a set-down pulse is changed as the time that an image lasts below a threshold change rate increases in the third embodiment of the method of driving a plasma display panel of the present invention. .

20 shows a fourth embodiment of a method of driving a plasma display panel of the present invention;

21A to 21B are diagrams for explaining an example in which a plurality of subfields are set in which the magnitude of the voltage of the reset pulse supplied to the scan electrode in the reset period is larger than the other subfields.

22A to 22B are diagrams for explaining that the magnitude of the voltage of the reset pulse changes as the time for which the image lasts below the threshold change rate increases in the fourth embodiment of the method of driving the plasma display panel of the present invention.

FIG. 23 is a view for explaining another example in which the magnitude of the voltage of the reset pulse changes as the time for which the image lasts below the threshold change rate increases in the fourth embodiment of the method of driving the plasma display panel of the present invention.

<Explanation of symbols for main parts of the drawings>

600: plasma display panel 601: reset pulse control unit

602: data driver 603: scan driver

604: sustain driver 605: drive voltage generator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device, and more particularly, to a plasma display device and a method of driving the same, which improve the reset pulse supplied to the scan electrode in the reset period to reduce the occurrence of sticking afterimages.

In general, a plasma display panel includes a discharge cell formed by a partition formed between a front panel and a rear panel, and each cell includes neon (Ne), helium (He), or a mixture of neon and helium (Ne + He) and An inert gas containing the same main discharge gas and a small amount of xenon is filled. When discharged by a high frequency voltage, the inert gas emits vacuum ultraviolet rays (Vacuum Ultra Violet-rays) to emit an phosphor formed in the discharge cell, thereby realizing an image. Such a plasma display panel has a spotlight as a next generation display device because of its thin and light configuration.

1 illustrates a structure of a general plasma display panel.

As illustrated in FIG. 1, a plasma display panel includes a front panel in which a plurality of sustain electrode pairs formed by pairing a scan electrode 102 and a sustain electrode 103 are arranged on a front substrate 101 that is a display surface on which an image is displayed. 100 and a rear panel 110 having a plurality of address electrodes 113 arranged so as to intersect with the plurality of storage electrode pairs described above on the rear substrate 111 forming the rear surface, are coupled in parallel with a predetermined distance therebetween. .

The front panel 100 is made of a scan electrode 102 and a sustain electrode 103, that is, a transparent electrode (a) formed of a transparent ITO material and a metal material to mutually discharge and maintain light emission of the cells in one discharge cell. The scan electrode 102 and the sustain electrode 103 provided as the bus electrode b are included in pairs. The scan electrode 102 and the sustain electrode 103 are covered by one or more upper dielectric layers 104 that limit the discharge current and insulate the electrode pairs, and facilitate discharge conditions on top of the upper dielectric layer 104. In order to do this, a protective layer 105 on which magnesium oxide (MgO) is deposited is formed.

The rear panel 110 is arranged in such a manner that a plurality of discharge spaces, that is, barrier ribs 112 of a stripe type (or well type) for forming discharge cells are maintained in parallel. In addition, a plurality of address electrodes 113 are arranged in parallel with the partition wall 112 to perform address discharge so that the inert gas in the discharge cell generates vacuum ultraviolet rays. On the upper side of the rear panel 110, red (R), green (G), and blue (B) phosphors 114 which emit visible light for image display during sustain discharge are coated. A lower dielectric layer 115 is formed between the address electrode 113 and the phosphor 114 to protect the address electrode 113.

The plasma display panel having the above-described structure is provided with a plurality of discharge cells in a matrix structure, and a driving unit including a driving circuit for supplying a predetermined pulse to the discharge cells is attached and driven. The coupling relationship between the plasma display panel and the driving unit is illustrated in FIG. 2.

2 is a view illustrating a coupling relationship between a plasma display panel and a driver.

As shown in FIG. 2, the driver includes, for example, a data driver 201, a scan driver 202, and a sustain driver 203. These driving units 201, 202, and 203 are connected to the plasma display panel 200 to form one plasma display device.

Here, the plasma display panel 200 is supplied with a data pulse from the data driver 201. These data pulses are generated when an image signal input from the outside goes through a predetermined signal processing process. The plasma display panel 200 receives the scan pulse and the sustain pulse output from the scan driver 202, and the sustain pulse output from the sustain driver 203. As described above, a discharge occurs in a cell selected by the scan pulse among a plurality of cells included in the plasma display panel 200 that receives the data pulse, the scan pulse, the sustain pulse, and the like, and the discharged cell emits light with a predetermined luminance. . Herein, the data driver 201, the scan driver 202, and the sustain driver 203 are address electrodes X ₁ to X _m of the plasma display panel 200 through a connecting body such as a flexible printed circuit (FPC) (not shown). ), Scan electrodes Y ₁ to Y _n , and sustain electrodes Z ₁ to Z _n .

A method of implementing image gradation in such a plasma display apparatus is shown in FIG. 3.

3 is a diagram illustrating a method of implementing image grayscale of a general plasma display panel.

As shown in FIG. 3, in the conventional method of expressing a gray level of a plasma display panel, a frame is divided into several subfields having different number of light emission times, and each subfield is again configured as a reset period (RPD) for initializing all cells. ) Is divided into an address period APD for selecting a cell to be discharged and a sustain period SPD for implementing gradation according to the number of discharges. For example, when displaying an image with 256 gray levels, a frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields SF1 to SF8 as shown in FIG. 3, and eight subfields. Each of the SFs SF1 to SF8 is divided into a reset period, an address period, and a sustain period.

The reset period and the address period of each subfield are the same for each subfield. The address discharge for selecting the cell to be discharged is caused by the voltage difference between the address electrode and the transparent electrode which is the scan electrode. The sustain period is increased at a rate of 2 ⁿ ( ^where n = 0, 1, 2, 3, 4, 5, 6, 7) in each subfield. In this way, since the sustain period is different in each subfield, the gray scale of the image is expressed by adjusting the sustain period of each subfield, that is, the number of sustain discharges. A driving waveform of one subfield in the method of driving the plasma display panel driven according to the image gray scale implementation method is as shown in FIG. 4.

4 is a diagram illustrating a driving waveform according to a driving method of a conventional plasma display panel.

As shown in Fig. 4, the plasma display panel erases the reset period for initializing all the cells, the address period for selecting the cells to be discharged, the sustain period for maintaining the discharge of the selected cells, and the wall charges in the discharged cells. It is divided into an erase period for driving.

In the reset period, a set-up waveform (Set-Up) is simultaneously applied to all scan electrodes in the set-up period. This setup waveform causes a weak dark discharge in the discharge cells of the entire screen. By this setup discharge, positive wall charges are accumulated on the address electrode and the sustain electrode, and negative wall charges are accumulated on the scan electrode.

In the set-down period, after the setup waveform is supplied, the set-down waveform starts to fall from the positive polarity voltage lower than the peak voltage of the setup waveform and falls to a specific voltage level below the ground (GND) level voltage. By generating a weak erase discharge in the cells, the wall charges excessively formed in the scan electrode are sufficiently erased. By this set down discharge, the wall charges to the extent that the address discharge can be stably generated remain uniformly in the cells.

In the address period, negative polarity scan pulses are sequentially applied to the scan electrodes, and data pulses of positive polarity are applied to the address electrodes in synchronization with the scan pulses. As the voltage difference between the scan pulse and the data pulse and the wall voltage generated in the reset period are added, an address discharge is generated in the discharge cell to which the data pulse is applied. In the cells selected by the address discharge, a wall charge is formed such that a discharge can occur when the sustain voltage Vs is applied. The sustain electrode is supplied with a positive voltage Vz so as to reduce the voltage difference with the scan electrode in at least one of the set down period and the address period so that no misdischarge occurs with the scan electrode.

In the sustain period, a sustain pulse Su is applied to the scan electrode and the sustain electrodes alternately. In the cell selected by the address discharge, as the wall voltage and the sustain pulse in the cell are added, a sustain discharge, that is, a display discharge, occurs between the scan electrode and the sustain electrode every time the sustain pulse is applied.

After the sustain discharge is completed, in the erase period, the voltage of the erase ramp waveform Ramp-ers having a small pulse width and voltage level is supplied to the sustain electrode to erase the wall charge remaining in the cells of the entire screen.

Meanwhile, in the conventional plasma display device driven as described above, a sticking afterimage appears due to the fixation of factors influencing the discharge such as phosphors.

5 is a view for explaining a sticking afterimage generated in the conventional plasma display panel.

Referring to FIG. 5, as shown in (a), a discharge is generated locally in a predetermined region 502 of the panel display surface 500. Subsequently, as shown in (b), when the above-mentioned discharge of the predetermined region 502 is stopped or a discharge of another pattern, that is, transferred to another image, the above-described predetermined region 502 appears as an afterimage in the next image. There is a problem.

Such afterimages intensify when the same screen continues or when the change of the screen is insignificant, causing fixed afterimages. For example, when there is no change rate of successive incoming image data or below a threshold change rate, sustain pulses are applied in the same or similar pattern on the same or similar area of the panel display surface. At this time, the fixation of the factors influencing the discharge such as the phosphor is further intensified, so that the image to be implemented is further fixed, and thus a fixation afterimage that deepens the afterimage appearing in the next image is generated.

On the other hand, the plasma display device is gradually pursuing high brightness, but in order to realize such high brightness, the peak brightness of the sustain pulse can be increased by increasing the peak value of the sustain pulse. However, when the peak value of the voltage, such as a sustain pulse, is high, the fluorescent material is excited by a strong discharge, thereby causing the stuck state to further increase the occurrence of sticking afterimages.

Accordingly, an object of the present invention is to provide a plasma display device and a driving method thereof for reducing a sticking afterimage resulting from fixation of wall charges in a discharge cell.

Another object of the present invention is to provide a plasma display device and a driving method thereof capable of improving image quality.

A plasma display apparatus according to the present invention for achieving the above object is to control the scan driver and the scan driver for driving the scan electrode, and the sub-frame of the frame according to the input image pattern Of one or more subfields of the field Supplied to the scan electrode in the setup period of the reset period And a reset pulse controller for adjusting a slope of a set-up pulse.

The reset pulse controller may be configured in the set-up period of the reset period of one or more subfields of the subfields of the frame when the rate of change of the image data into which the pattern of the image is input is a residual pattern that lasts longer than a threshold time. The absolute value of the slope of the set-up pulses supplied to the scan electrodes is larger than other subfields.

In addition, the threshold rate of change is a ratio of the difference between the image data of the previous frame and the image data of the current frame has a value of 10% of the total image data, the threshold time is determined within the range of 1 second or more within 10 seconds. It features.

Further, the threshold time has at least two different values, wherein the at least two threshold times include a first threshold time and a second threshold time later than the first threshold time, and after the first threshold time, the second threshold time. The absolute value of the slope of the set-up pulse supplied to the scan electrode in the setup period of the reset period of one or more of the subfields of the frame before the threshold time is smaller than after the second threshold time. It is characterized by.

In addition, the reset pulse controller controls the gray level from the subfield having the lowest gray scale weight in the subfield of which the absolute value of the slope of the set-up pulse supplied to the scan electrode is increased in the setup period of the reset period. The subfields may be subfields up to a predetermined number of subfields in order of low weight.

In addition, the driving method of the plasma display panel according to the present invention for achieving the above object is to perform one or more subfields among the subfields of the frame according to the pattern of the input image. Supplied to the scan electrode in the setup period of the reset period It is characterized in that the slope of the set-up pulse is adjusted.

Further, when the change rate of the image data to which the image pattern is input is a residual image pattern that lasts more than a threshold time at or below a threshold change rate, the setup supplied to the scan electrode in the setup period of the reset period of one or more subfields of the subfields of the frame. The absolute value of the slope of the (Set-Up) pulse is larger than other subfields.

In addition, the threshold rate of change is a ratio of the difference between the image data of the previous frame and the image data of the current frame has a value of 10% of the total image data, the threshold time is determined within the range of 1 second or more within 10 seconds. It features.

Further, the threshold time has at least two different values, wherein the at least two threshold times include a first threshold time and a second threshold time later than the first threshold time, and after the first threshold time, the second threshold time. The absolute value of the slope of the set-up pulse supplied to the scan electrode in the setup period of the reset period of one or more subfields of the subfield of the frame before the threshold time is smaller than after the second threshold time. It features.

The subfields in which the absolute value of the slope of the set-up pulses supplied to the scan electrodes in the setup period of the reset period are larger than the other subfields among the subfields of the frame are from the subfield with the lowest gray scale weight. The subfields may be subfields up to a predetermined number of subfields in order of low weight.

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

6 is a view for explaining the structure of the plasma display device of the present invention.

As shown in FIG. 6, the plasma display apparatus of the present invention includes a plasma display panel 600, a data driver 602, a scan driver 603, a sustain driver 604, and a reset pulse controller 601. Including the device.

For example, the plasma display device of the present invention is formed of a frame by a combination of at least one subfield in which drive pulses are applied to the address electrodes X1 to Xm, the scan electrodes Y1 to Yn, and the sustain electrode Z. Plasma display panel 600 representing an image, data driver 602 for supplying data to address electrodes X1 to Xm formed in plasma display panel 600, and scan electrodes Y1 to Yn A reset period by controlling the scan driver 603 for driving, the sustain driver 604 for driving the sustain electrodes Z as common electrodes, and the scan driver 603 described above when the plasma display panel 600 is driven. Is one of the number of reset pulses, the slope of the set-up pulse of the reset pulse, the slope of the set-down pulse of the reset pulse, or the magnitude of the voltage of the reset pulse. And a reset pulse controller 601 for adjusting the phase, and a driving voltage generator 605 for supplying a driving voltage required for each driver (602, 603, 604).

Here, the above-described plasma display panel 600 is bonded to the front panel (not shown) and the rear panel (not shown) at regular intervals, a plurality of electrodes, for example, scan electrodes (for example) Y1 to Yn and the sustain electrode Z are formed in pairs, and address electrodes X1 to Xm are formed to intersect the scan electrodes Y1 to Yn and the sustain electrode Z described above.

The data driver 602 is subjected to inverse gamma correction and error diffusion by an inverse gamma correction circuit, an error diffusion circuit, and the like, and then data mapped to each subfield is supplied by the subfield mapping circuit. The data driver 602 samples and latches data in response to a data timing control signal CTRX from a timing controller (not shown), and then supplies the data to the address electrodes X1 to Xm.

The scan driver 603 supplies the reset pulses to the scan electrodes Y1 to Yn during the reset period under the control of the reset pulse controller 601, and the scan pulses to the scan electrodes Y1 to Yn during the address period. The sustain pulse is supplied to the scan electrodes Y1 to Yn during the sustain period under the control of the timing controller (not shown), and the erase pulse is supplied to the scan electrodes Y1 to Yn during the erase period.

The sustain driver 604 supplies a bias voltage having a predetermined magnitude to the sustain electrodes Z during the address period, and alternately operates with the scan driver 603 described above during the sustain period to sustain the sustain pulses Vs. (Z), and erase pulses are supplied to the sustain electrode (Z) during the erase period.

The reset pulse controller 601 supplies a predetermined control signal to the scan driver 603 to control the operation timing and synchronization of the scan driver 603 in the reset period, so that the scan driver 603 receives an input image. At least one of the subfields of the frame according to the pattern of Adjust the number of reset pulses supplied to the scan electrode Y, the slope of the set-up pulse of the reset pulse, the slope of the set-down pulse of the reset pulse or the voltage of the reset pulse in the reset period. Do it.

In this way, the number of reset pulses supplied to the scan electrode Y in the reset period, the slope of the set-up pulse of the reset pulse, the slope of the set-down pulse of the reset pulse, or the voltage of the reset pulse. The reason for adjusting the size is to improve the sticking afterimage of the image implemented when the plasma display device is driven.

Such a function and operation of the plasma display device of the present invention will be described in more detail with reference to a method of driving the plasma display panel.

7 is a diagram showing a first embodiment of a method of driving a plasma display panel of the present invention.

As illustrated in FIG. 7, in the plasma display panel, a plurality of subfields form one frame to display an image. Such a plasma display panel includes a reset period (a) in which one subfield initializes all cells, an address period (b) for selecting a cell to be discharged, a sustain period for maintaining discharge of the selected cell, and a discharged cell in the discharged cell. The driving is divided into an erasing period (c) for erasing the wall charges. Here, in the above-described reset period (a), the reset pulses supplied to the scan electrode (Y) are adjusted according to the pattern of the image whose number is input.

That is, according to the pattern of the image inputted by the reset pulse control unit 601 of FIG. Supplied to the scan electrode Y in the reset period a. The number of reset pulses is adjusted.

The reset pulse adjusted according to the input image pattern will be described in more detail with reference to FIG. 8 as follows.

FIG. 8 is a diagram for describing in detail the number of reset pulses supplied in a reset period among the driving waveforms of the plasma display panel of FIG. 7.

In FIG. 8, only reset pulses having the features of the present invention are shown, in which more reset pulses are applied to the first subfield shown in FIG. 7 than other subfields. When the input image pattern is the afterimage pattern, the number of reset pulses supplied to the scan electrode in the reset period is different from the subfield (the first subfield in FIG. 8) having the lowest gray scale weight among the n subfields of the frame. It can be applied in two more to remove the stuck state.

The afterimage pattern described above is an image pattern for generating a fixed afterimage in an image to be implemented, and means that the input image data is an image pattern when the change rate of the image persists for a threshold time or more below a threshold change rate. In the case of such an afterimage pattern, the wall charge distribution in the discharge cell is particularly hardened, so that even after the next image is input, the wall charge generated by the previous image is maintained for a certain time, thereby causing a sticking afterimage. .

Accordingly, in the present invention, when the input image pattern is the afterimage pattern, as shown in FIG. 8, the number of reset pulses supplied to the scan electrodes is increased in the reset period to cause strong discharge, thereby distributing the distribution of wall charges in the fixed discharge cells. It shakes to suppress the occurrence of sticking afterimages.

The threshold rate of change in the afterimage pattern may be limited to less than 10% of the total image data as a ratio of the difference between the image data of the previous frame and the image data of the current frame. In addition, a threshold time can be limited to what is determined within the range of 1 second or more and 10 second or less.

More preferably, although not shown in the drawing, the reset pulse supplied to the scan electrode in the reset period is made negative so that the positive ions of the electrons are attracted to the panel with the scan electrode, thereby affecting the opposite panel-side phosphor. By minimizing the fixation due to the reset pulse can be reduced. Accordingly, the sticking afterimage can be more effectively controlled.

Meanwhile, unlike the above-described FIGS. 7 to 8, a plurality of subfields to which a plurality of reset pulses are supplied may be set among a plurality of subfields of a frame, which will be described with reference to FIGS. 9A to 9B.

9A to 9B are diagrams for explaining an example in which a plurality of subfields having a plurality of reset pulses supplied to the scan electrode in a reset period is set to a plurality of them.

As shown in Figs. 9A to 9B, among the subfields of the frame, a plurality of subfields having a plurality of reset pulses supplied to the scan electrode in the reset period are plural, preferably the gradation weights from the subfields having the lowest gradation weights. Can be subfields up to a predetermined number of subfields in ascending order. More preferably, the subfield having a plurality of reset pulses supplied to the scan electrodes is the third subfield in the order of the lowest gray scale weight from the lowest gray scale weight.

In FIG. 9A, a plurality of subfields having a plurality of reset pulses supplied to the scan electrode in the reset period, that is, the scan electrode in the reset period of the first subfield having the lowest gray scale weight among the first, second, and third subfields, are used as scan electrodes. The number of reset pulses supplied is larger than the other second and third subfields. Accordingly, by applying more reset pulses to the first subfield where the discharge is most unstable, it is possible to stabilize the discharge more.

In FIG. 9B, the number of reset pulses supplied to the scan electrodes in the reset periods of the plurality of subfields and the first, second, and third subfields, wherein the number of reset pulses is supplied to the scan electrodes in the reset period among the subfields of the frame. It is possible to easily control the driving by applying two to each of the same.

Meanwhile, the number of reset pulses may be adjusted according to the threshold time of the above-described afterimage pattern, which will be described with reference to FIGS. 10A to 10B.

10A to 10B are diagrams for explaining that the number of reset pulses changes as the time for which the image lasts below the threshold change rate increases in the first embodiment of the method of driving the plasma display panel of the present invention.

As shown in Figs. 10A and 10B, the scan period is reset in one or more subfields of the subfields of the frame as the time duration of the change rate of the input image data above the threshold time of the afterimage pattern continues below the threshold change rate increases. The number of reset pulses supplied to the electrode is also increased.

For example, as shown in FIG. 10A, a reset pulse may be added to the first subfield having the lowest gray scale weight, and as shown in FIG. 10B, a reset pulse may be added to the second subfield so as to be controlled in the same manner as the first subfield. You can also add

In addition, the number of additional reset pulses may be adjusted to be constant as the time duration of the change rate of the image data input above the threshold time increases below the threshold change rate.

FIG. 11 is a view for explaining another example in which the number of reset pulses changes as the time for which the image lasts below the threshold change rate increases in the first embodiment of the method of driving the plasma display panel of the present invention.

As shown in FIG. 11, the threshold time may have two or more different values, wherein the threshold time includes a first threshold time and a second threshold time later than the first threshold time, and after the first threshold time, the second threshold time. The number of reset pulses supplied to the scan electrodes in the reset period of one or more of the subfields of the frame before the threshold time is made smaller than after the second threshold time. In other words, by dividing the threshold time by n, the driving time can be systematically controlled by adding one reset pulse constantly as the threshold time increases.

As described above, if the number of reset pulses is increased as the time for which the rate of change of the image data lasts below the threshold rate of change increases, the wall charge in the discharge cell increases as the time for which the rate of change of the image data lasts below the threshold rate of change increases. Fixation of distribution can be effectively improved.

Unlike adjusting the number of reset pulses above, when the reset pulse is input in the setup period of the reset period, the slope of the set-up pulse that reaches the set-up voltage with a predetermined slope among the reset pulses may be adjusted. Next, as shown in FIG.

12 is a diagram showing a second embodiment of the method for driving the plasma display panel of the present invention.

As shown in FIG. 12, when a pattern of an input image is an afterimage pattern, a scan is performed in a setup period of a reset period in a subfield (the first subfield in FIG. 12) having the lowest gray scale weight among the n subfields of a frame. The absolute value of the slope of the set-up pulses supplied to the electrodes is made larger than the other subfields. The reason is that increasing the absolute value of the slope of the set-up pulse can cause strong discharge due to the rapid rate of voltage change per hour, thereby shaking the distribution of wall charge in the fixed discharge cell more strongly, thereby causing the sticking afterimage. Can be effectively suppressed.

Since the afterimage pattern is the same as described above, it is omitted.

On the other hand, the length t1 of the setup period of the subfield which makes the absolute value of the slope of the set-up pulse supplied to the scan electrode in the setup period of the reset period among the subfields of the frame larger than the other subfields is different. To be the same as the fields t2, t3 ... tn. Therefore, the drive control is facilitated by making the length of each subfield the same.

Alternatively, although not shown in the drawing, the length of the setup period of the subfield which makes the absolute value of the slope of the set-up pulse supplied to the scan electrode in the setup period of the reset period among the subfields of the frame larger than the other subfields ( t1) may be shorter than other subfields t2, t3... tn. This can shorten the length of the setup period, thereby speeding up the operation, and it is advantageous in that other driving periods, such as an address period and a sustain period, can be secured.

On the other hand, more preferably, the reset pulse supplied to the scan electrode in the reset period is negative, although not shown in the drawings.

On the other hand, unlike FIG. 12 described above, a plurality of subfields may be set to increase the absolute value of the slope of the set-up pulse from the plurality of subfields of the frame than other subfields. Same as 13b.

13A to 13B are diagrams for explaining an example in which a plurality of subfields are set in which the absolute value of the inclination of the set-up pulses supplied to the scan electrodes in the setup period of the reset period is larger than the other subfields. .

As shown in Figs. 13A to 13B, among the subfields of the frame, there are a plurality of subfields in which the absolute value of the slope of the set-up pulses supplied to the scan electrodes in the setup period of the reset period is larger than the other subfields. In this case, the subfield may be a subfield from the subfield having the lowest gray scale weight to a predetermined number of subfields in the order of the low gray scale weight. More preferably, the subfields are the third subfields in the order of the lowest gradation weights from the lowest gradation weights.

In FIG. 13A, a gray scale weight among a plurality of subfields, that is, first, second, and third subfields, in which an absolute value of a slope of a set-up pulse supplied to the scan electrode in a setup period of a reset period is made larger than other subfields. The absolute value of the slope of the set-up pulses supplied to the scan electrodes in the setup period of the reset period of the lowest first subfield is larger than the other second and third subfields. Accordingly, the absolute value of the slope of the set-up pulse is increased in the first subfield where the discharge is most unstable, so that the discharge can be initialized more reliably and the discharge can be stabilized.

In FIG. 13B, a plurality of subfields, first, second, and third subfields in which an absolute value of a slope of a set-up pulse supplied to a scan electrode in a setup period of a reset period among subfields of a frame is larger than other subfields. In the setup period of the field reset period, the absolute value of the inclination of the set-up pulses supplied to the scan electrodes is equally applied to each other to facilitate driving control.

Meanwhile, the inclination of the set-up pulses may be adjusted according to the threshold time of the afterimage pattern described above, which will be described with reference to FIGS. 14A to 14B.

14A to 14B are diagrams for describing a change in the slope of a set-up pulse as the time for which an image lasts below a threshold change rate increases in the second embodiment of the method of driving a plasma display panel of the present invention. to be.

As shown in Figs. 14A and 14B, the setup period of the reset period of one or more subfields of the subfields of the frame is increased as the time duration of the change rate of the input image data above the threshold time of the afterimage pattern continues below the threshold change rate is increased. It is possible to increase the absolute value of the slope of the set-up pulse supplied to the scan electrode in the period or to increase the subfield in which the absolute value of the slope of the set-up pulse is increased.

For example, as shown in FIG. 14A, the absolute value of the slope of the set-up pulse is increased in the first subfield having the lowest gray scale weight than other subfields, and as the time duration below the threshold change rate increases, 1 The absolute value of the slope of the set-up pulse of the subfield may be made larger.

Alternatively, as shown in FIG. 14B, the subfield which can control the same as the first subfield in which the absolute value of the slope of the set-up pulse is made larger than the other subfields is increased. That is, the absolute value of the slope of the set-up pulse may also be made larger in the second subfield than in the other subfields in the same manner as in the first subfield.

In addition, it is also possible to adjust the slope of the set-up pulse, which increases as the change time of the image data input above the threshold time continues below the threshold change rate, or to set up the set-up. It is also possible to constantly increase the subfield which increases the absolute value of the slope of the pulse than other subfields.

FIG. 15 is a view for explaining another example in which a slope of a set-up pulse is changed as the time for which an image lasts below a threshold change rate increases in the second embodiment of the method of driving a plasma display panel of the present invention. to be.

As shown in FIG. 15, the threshold time may have two or more different values, wherein the threshold time includes a first threshold time and a second threshold time later than the first threshold time, and after the first threshold time, the second threshold time. The second threshold time is the number of subfields in which the absolute value of the slope of a set-up pulse supplied to the scan electrode is increased in the setup period of the reset period of one or more of the subfields of the frame before the threshold time. Do less than after.

That is, as an example, in FIG. 15, the subfield is divided into n threshold times so that the absolute value of the slope of the set-up pulses supplied to the scan electrodes in the setup period of the reset period is larger than other subfields as the threshold time increases. It is possible to control the driving systematically by increasing the constant by one.

As such, as the time for which the rate of change of the image data changes below the threshold rate of change increases, when the subfield in which the absolute value of the slope of the set-up pulse is increased larger than other subfields is increased, the rate of change of the image data becomes critical. It is possible to effectively improve the solidification of the wall charge distribution in the discharge cells, which increases as the time duration to be below the change rate increases.

Unlike adjusting the absolute value of the slope of the set-up pulse above, the slope of the set-down pulse reaching a specific voltage level with a predetermined slope after the setup waveform in the set-down period of the reset period is adjusted. It may also be described as follows in FIG.

16 shows a third embodiment of a method of driving a plasma display panel of the present invention.

As shown in FIG. 16, when the input image pattern is the afterimage pattern, the subfield (the first subfield in FIG. 16) having the lowest gray scale weight among the n subfields of the frame is scanned in the set down period of the reset period. The absolute value of the slope of the set-down pulse supplied to the electrode is larger than the other subfields. The reason is that if the absolute value of the slope of the set-down pulse is increased, the strong discharge may be caused by the rapid rate of voltage change per hour, thereby shaking the distribution of the wall charges in the fixed discharge cells more strongly, thereby causing the sticking afterimage. Can be effectively suppressed.

Since the afterimage pattern is as described above, it is omitted.

On the other hand, the length t1 of the setdown period of the subfield, in which the absolute value of the slope of the set-down pulse supplied to the scan electrode in the setdown period of the reset period among the subfields of the frame, is larger than the other subfields. To be the same as the fields t2, t3 ... tn. Therefore, the drive control is facilitated by making the length of each subfield the same.

Alternatively, although not shown in the drawings, the length of the setup period of the subfield in which the absolute value of the slope of the set-up pulse supplied to the scan electrode in the setup period of the reset period among the subfields of the frame is larger than the other subfields ( t1) is made shorter than other subfields t2, t3 ... tn. This can shorten the length of the setup period, thereby speeding up the operation, and it is advantageous in that other driving periods, such as an address period and a sustain period, can be secured.

On the other hand, more preferably, the reset pulse supplied to the scan electrode in the reset period is negative, although not shown in the drawing, the reason is as described above.

On the other hand, unlike FIG. 16 described above, among the plurality of subfields of the frame, a plurality of subfields may be set in which the absolute value of the slope of the set-down pulse is larger than other subfields. Same as FIG. 17B.

17A to 17B are diagrams for explaining an example in which a plurality of subfields are set in which the absolute value of the slope of the set-down pulses supplied to the scan electrodes in the setdown period of the reset period is larger than the other subfields. .

As shown in Figs. 17A to 17B, among the subfields of the frame, there are a plurality of subfields in which the absolute value of the slope of the set-down pulse supplied to the scan electrode in the setdown period of the reset period is larger than the other subfields. Preferably, the subfields may be subfields ranging from the subfield having the lowest gray scale weight to the predetermined number of subfields in the order of the low gray scale weight. More preferably, the subfields are the third subfields in the order of the lowest gradation weights from the lowest gradation weights.

In FIG. 17A, a gray scale weight among a plurality of subfields, that is, first, second, and third subfields, in which an absolute value of a slope of a set-down pulse supplied to a scan electrode is increased in a reset period of a reset period than that of other subfields. The absolute value of the slope of the set-down pulses supplied to the scan electrodes in the reset period of the reset period of the lowest first subfield is greater than the other second and third subfields. As a result, the absolute value of the slope of the set-down pulse is increased in the first subfield where the discharge is most unstable, so that the discharge can be initialized more reliably to stabilize the discharge.

In FIG. 17B, a plurality of subfields, first, second, and third subfields in which an absolute value of a slope of a set-down pulse supplied to a scan electrode in a setdown period of a reset period among subfields of a frame is larger than other subfields. The absolute value of the slope of the set-down pulses supplied to the scan electrodes in the set-down period of the reset period of the field may be equally applied to each other to facilitate driving control.

Meanwhile, the inclination of the set-down pulse may be adjusted according to the threshold time of the above-described afterimage pattern, which will be described with reference to FIGS. 18A to 18B.

18A to 18B are diagrams for explaining that the slope of a set-down pulse is changed as the time for which an image lasts below a threshold change rate increases in the third embodiment of the method of driving a plasma display panel of the present invention. to be.

As shown in Figs. 18A and 18B, the set-down of the reset period of one or more subfields of the subfields of the frame is increased as the time for the change rate of the input image data to exceed the threshold time of the afterimage pattern to increase below the threshold change rate increases. In the period, the absolute value of the slope of the set-down pulse supplied to the scan electrode may be increased or the subfield in which the absolute value of the slope of the set-down pulse is increased may be increased.

For example, as shown in FIG. 18A, the absolute value of the slope of the set-down pulse is made larger in the first subfield having the lowest gray scale weight than other subfields, and as the time duration below the threshold rate of change increases. The absolute value of the slope of the set-down pulse of the first subfield may be made larger.

Alternatively, as shown in FIG. 18B, a subfield capable of controlling the same as the first subfield in which the absolute value of the slope of the set-down pulse is made larger than other subfields is increased. That is, the absolute value of the slope of the set-down pulse in the second subfield may be made larger than other subfields in the same manner as the first subfield.

In addition, it is also possible to adjust the slope of the set-down pulse, which increases as the time that the change rate of the image data input above the threshold time continues below the threshold change rate increases, or set-down. Subfields that increase the absolute value of the slope of the pulse larger than the other subfields may be constantly increased.

FIG. 19 is a view for explaining another example in which a slope of a set-down pulse is changed as the time for which an image lasts below a threshold change rate increases in the third embodiment of the method of driving a plasma display panel of the present invention. to be.

As shown in FIG. 19, the threshold time may have two or more different values, wherein the threshold time includes a first threshold time and a second threshold time later than the first threshold time, and after the first threshold time, the second threshold time. In the set-down period of the reset period of one or more subfields of the subfields of the frame before the threshold time, the second threshold time is the number of subfields with the absolute value of the slope of the set-down pulse supplied to the scan electrode increased. Do less than after.

That is, as an example, in FIG. 19, the threshold time is divided into n subfields so that the absolute value of the slope of the set-down pulse supplied to the scan electrode in the setdown period of the reset period is larger than the other subfields as the threshold time increases. It is possible to control the driving systematically by increasing the constant by one.

As described above, as the time for which the rate of change of the image data continues below the threshold rate of change increases, increasing the subfield in which the absolute value of the slope of the set-down pulse is larger than other subfields increases the rate of change of the image data. It is possible to effectively improve the solidification of the wall charge distribution in the discharge cells, which increases as the time duration to be below the change rate increases.

Unlike adjusting the absolute value of the slope of the set-down pulse in the above, it is also possible to adjust the magnitude of the voltage of the reset pulse supplied to the scan electrode in the reset period.

20 shows a fourth embodiment of a method of driving a plasma display panel of the present invention.

As shown in FIG. 20, when the pattern of the input image is the afterimage pattern, the subfield (the first subfield in FIG. 20) having the lowest gray scale weight among the n subfields of the frame is supplied to the scan electrode in the reset period. The magnitude (Vsetup2) of the voltage of the reset pulse to be made is larger than the other subfields. The reason for this is that if the voltage of the reset pulse is increased, strong discharge can be caused by the high peak voltage pulse, thereby shaking the distribution of wall charges in the fixed discharge cells more effectively, thereby effectively suppressing the occurrence of sticking afterimages. Can be.

Since the afterimage pattern is as described above, it is omitted.

On the other hand, more preferably, the reset pulse supplied to the scan electrode in the reset period is negative, although not shown in the drawing, the reason is as described above.

On the other hand, unlike FIG. 20 described above, a plurality of subfields may be set in a plurality of subfields of the frame, the magnitude of the reset pulse voltage being larger than other subfields, which will be described with reference to FIGS. 21A to 21B.

21A to 21B are diagrams for explaining an example in which a plurality of subfields are set in which the magnitude of the voltage of the reset pulse supplied to the scan electrode is larger than other subfields in the reset period.

As shown in Figs. 21A to 21B, among the subfields of the frame, there are a plurality of subfields in which the magnitude of the voltage of the reset pulse supplied to the scan electrode in the reset period is larger than the other subfields. The subfields may be subfields up to a predetermined number of subfields in descending order of gray scale weights. More preferably, the subfields are the third subfields in the order of the lowest gradation weights from the lowest gradation weights.

In FIG. 21A, a plurality of subfields, i.e., a first sub with the lowest gray scale weight among the first, second, and third subfields, in which the magnitude of the voltage of the reset pulse supplied to the scan electrode in the reset period is larger than the other subfields Vsetup1. In the reset period of the field, the magnitude Vsetup3 of the voltage of the reset pulse supplied to the scan electrode is larger than the other second and third subfields Vsetup2. Accordingly, by increasing the magnitude of the voltage of the reset pulse in the first subfield where the discharge is most unstable, the discharge can be initialized more reliably and the discharge can be stabilized.

In FIG. 21B, a scan is performed in a reset period of a plurality of subfields, first, second, and third subfields in which the magnitude of the voltage of the reset pulse supplied to the scan electrode in the reset period among the subfields of the frame is larger than the other subfields Vsetup1. The control of driving can be facilitated by applying the same magnitude Vsetup2 of the voltage of the reset pulse supplied to the electrode.

Meanwhile, the inclination of the set-down pulse may be adjusted according to the threshold time of the above-described afterimage pattern, which will be described with reference to FIGS. 22A to 22B.

22A to 22B are diagrams for explaining that the magnitude of the voltage of the reset pulse changes as the time for which the image lasts below the threshold change rate increases in the fourth embodiment of the method of driving the plasma display panel of the present invention.

As shown in Figs. 22A and 22B, the scan period is reset in the reset period of one or more subfields of the subfields as the change time of the input image data over the threshold time of the afterimage pattern continues below the threshold change rate. The magnitude of the voltage of the reset pulse supplied to the electrode may be increased or the subfield may be increased in which the magnitude of the voltage of the reset pulse is increased.

For example, as shown in FIG. 22A, the voltage of the reset pulse is increased in the first subfield having the lowest gray scale weight than other subfields, and the reset time of the first subfield is increased as the time duration below the threshold change rate increases. The magnitude of the voltage of the pulse can be made larger.

Alternatively, as shown in FIG. 22B, a subfield which can be controlled in the same way as the first subfield in which the voltage of the reset pulse is made larger than other subfields is increased. In other words, the voltage of the reset pulse may be made larger in the second subfield than other subfields in the same manner as in the first subfield.

In addition, as the time that the change rate of the image data input above the threshold time lasts below the threshold change rate increases, the voltage level of the reset pulse that is increased may be adjusted to be constant. It is also possible to increase the subfields to be enlarged constantly.

FIG. 23 is a view for explaining another example in which the magnitude of the voltage of the reset pulse changes as the time for which the image lasts below the threshold change rate increases in the fourth embodiment of the method of driving the plasma display panel of the present invention.

As shown in FIG. 23, the threshold time may have two or more different values, wherein the threshold time includes a first threshold time and a second threshold time later than the first threshold time, and after the first threshold time, the second threshold time. The number of subfields having a larger magnitude of the voltage of the reset pulse supplied to the scan electrode in the reset period of one or more of the subfields of the frame before the threshold time is made smaller than after the second threshold time.

That is, as an example, in FIG. 23, when the threshold time is increased by dividing the threshold time by n, the subfield which increases the voltage of the reset pulse supplied to the scan electrode in the reset period more than the other subfields is driven one by one. Can be controlled systematically.

As such, when the change rate of the image data continues below the threshold rate of change, and the subfield whose magnitude of the reset pulse is increased larger than the other subfields increases, the change rate of the image data continues below the threshold rate of change. This increase can effectively improve the fixation of the wall charge distribution in the discharge cells which increases.

As described above, the plasma display apparatus of the present invention is configured to display one or more subfields among the subfields of the frame according to the input image pattern. The number of reset pulses supplied to the scan electrode Y in the reset period, the slope of the set-up pulse of the reset pulse, the slope of the set-down pulse of the reset pulse, or the magnitudes of the voltages of the reset pulse, respectively. In addition, by adjusting one or more of these in combination, it is possible to effectively reduce the sticking afterimage.

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.

As described above in detail, the plasma display device and the driving method thereof according to the present invention have the effect of reducing the solidification of the wall charges in the discharge cells.

In addition, the plasma display device and the driving method thereof according to the present invention have the effect of improving the image quality.

Claims (10)

A plasma display panel including a scan electrode; A scan driver for driving the scan electrode; And If the pattern of the input image is the afterimage pattern by controlling the scan driver, one or more subfields of Supplied to the scan electrode in the setup period of the reset period A reset pulse controller configured to adjust an absolute value of a slope of a set-up pulse larger than other subfields; Plasma display device comprising a. The method of claim 1, The reset pulse controller In the case where the change rate of the input image data is a residual pattern that lasts more than a threshold time at or below a threshold change rate, a setup supplied to a scan electrode in a setup period of a reset period of one or more subfields of a frame -Up) Plasma display device characterized in that the absolute value of the slope of the pulse is made larger than the other subfields. The method of claim 2, The threshold change rate is a ratio of the difference between the image data of the previous frame and the image data of the current frame and has a value of 10% of the total image data. And the threshold time is determined within a range of 1 second to 10 seconds. The method of claim 2, The threshold time has at least two different values, The at least two threshold times comprise a first threshold time and a second threshold time later than the first threshold time, The absolute value of the slope of a set-up pulse supplied to the scan electrode in the setup period of the reset period of one or more subfields of the subfields of the frame after the first threshold time is equal to And smaller than after said second threshold time. The method of claim 2, The reset pulse controller The number of subfields in which the absolute value of the slope of the set-up pulses supplied to the scan electrodes is increased in the set-up period of the reset period among the subfields of the frame is a predetermined number from the subfield having the lowest gray scale weight in the order of low gray scale weight. And a subfield up to a subfield of. A driving method of a plasma display panel including a reset period, an address period, and a sustain period, If the pattern of the input image is the afterimage pattern, one or more subfields Supplied to the scan electrode in the setup period of the reset period A method of driving a plasma display panel, wherein an absolute value of a slope of a set-up pulse is adjusted to be larger than another subfield. The method of claim 6, In the case where the change rate of the input image data is a residual pattern that lasts more than a threshold time at or below a threshold change rate, a setup supplied to a scan electrode in a setup period of a reset period of one or more subfields of a frame -Up) The absolute value of the slope of the pulse is larger than the other sub-field driving method of the plasma display panel. The method of claim 7, wherein The threshold change rate is a ratio of the difference between the image data of the previous frame and the image data of the current frame and has a value of 10% of the total image data. And the threshold time is determined within a range of 1 second to 10 seconds. The method of claim 7, wherein The threshold time has at least two different values, The at least two threshold times comprise a first threshold time and a second threshold time later than the first threshold time, The absolute value of the slope of the set-up pulse supplied to the scan electrode in the setup period of the reset period of one or more subfields of the subfield of the frame after the first threshold time is equal to And less than after the second threshold time. The method of claim 7, wherein The subfields in which the absolute value of the slope of the set-up pulses supplied to the scan electrodes in the setup period of the reset period are larger than the other subfields among the subfields of the frame, A subfield up to a predetermined number of subfields in a low order.

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