KR100468415B1 - Method for driving plasma display panel - Google Patents

Abstract

The present invention relates to a method of driving a plasma display panel which increases brightness and reduces image quality deterioration.

A driving method of a plasma display panel according to the present invention includes a plurality of subfields in one field, and a driving method of a plasma display panel including scan electrodes and address electrodes for generating a discharge. Setting the discharge period, resetting discharge of the odd-numbered discharge cells by the reset pulse on the odd-numbered scan line of the first subfield, and scanning the negative polarity applied to the odd-numbered scan line of the first subfield. Causing an address discharge of an odd-numbered discharge cell by a pulse and a positive data pulse applied to the address electrode, a data pulse applied to the address electrode of the first subfield and the data pulse to the even-th scan line; Sustain discharge of even-numbered discharge cells is caused by alternating sustain pulses. It is characterized by including the steps:

Description

Driving Method of Plasma Display Panel {METHOD FOR DRIVING PLASMA DISPLAY PANEL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a method of driving a plasma display panel capable of increasing brightness and reducing image degradation.

Plasma Display Panel (hereinafter referred to as "PDP") is used to excite and emit phosphors by using ultraviolet rays generated when an inert mixed gas such as He + Xe, Ne + Xe, He + Xe + Ne is discharged. Will be displayed. Such PDPs are not only thin and large in size, but also have improved in image quality due to recent technology development.

Referring to FIG. 1, a discharge cell of a conventional three-electrode AC surface discharge type PDP has a scan electrode (Y) and a sustain electrode (Z), and an address electrode (X) orthogonal to the scan electrode (Y) and the sustain electrode (Z). It is provided.

At the intersection of the scan electrode Y, the sustain electrode Z and the address electrode X, a cell 1 for displaying any one of red, green and blue is formed. The scan electrode Y and the sustain electrode Z are formed on an upper substrate (not shown). On the upper substrate, a dielectric layer and an MgO protective layer (not shown) are stacked. The address electrode X is formed on the lower substrate (not shown). On the lower substrate, partition walls are formed to prevent optical and electrical interference between horizontally adjacent cells. Phosphors are excited on the lower substrate and the partition walls to be excited by vacuum ultraviolet rays and emit visible light. An inert mixed gas such as He + Xe, Ne + Xe, He + Xe + Ne is injected into the discharge space between the upper substrate and the lower substrate.

The PDP is time-divisionally driven by dividing one frame into several subfields having different number of emission times in order to implement grayscale of an image. Each subfield is divided into an initialization period for initializing the full screen, an address period for selecting a scan line and selecting a cell in the selected scan line, and a sustain period for implementing gray levels according to the number of discharges. For example, when the image is to be displayed with 256 gray levels, as shown in FIG. 2, the frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields SF1 to SF8. As described above, each of the eight subfields SF1 to SF8 is divided into an initialization period, an address period, and a sustain period. The initialization period and the address period of each subfield are the same for each subfield, while the sustain period and the number of sustain pulses allocated thereto are 2 ⁿ (n = 0,1,2,3,4,5,6) in each subfield. , 7).

3 shows driving waveforms of a PDP supplied to two subfields.

Referring to FIG. 3, the PDP is driven by being divided into an initialization period for initializing the full screen, an address period for selecting a cell, and a sustain period for maintaining discharge of the selected cell.

In the initialization period, the rising ramp waveform Ramp-up is simultaneously applied to all the scan electrodes Y in the setup period SU. This rising ramp waveform (Ramp-up) causes a discharge in the cells of the full screen. By this setup discharge, positive wall charges are accumulated on the address electrode X and the sustain electrode Z, and negative wall charges are accumulated on the scan electrode Y. After the rising ramp waveform Ramp-up is supplied in the set-down period SD, the falling ramp waveform Ramp-down falling at the positive voltage lower than the peak voltage of the rising ramp waveform Ramp-up is divided into the scan electrodes. Is simultaneously applied to Y). Ramp-down causes a slight erase discharge in the cells, thereby partially erasing the excessively formed wall charge. This set-down discharge causes the wall charges to be uniformly retained in the cells so that the address discharge can be stably generated.

In the address period, the negative scan pulse scan is sequentially applied to the scan electrodes Y, and the positive data pulse data is applied to the address electrodes X in synchronization with the scan pulse scan. As the voltage difference between the scan pulse and the data pulse and the wall voltage generated during the initialization period are added, an address discharge is generated in the cell to which the data pulse is applied. In the cells selected by the address discharge, wall charges are formed such that a discharge can occur when a sustain voltage is applied.

The sustain electrode Z is supplied with a positive DC voltage Zdc during the set down period and the address period.

In the sustain period, sustain pulses sus are alternately applied to the scan electrodes Y and the sustain electrodes Z. FIG. The cell selected by the address discharge has a sustain discharge, that is, a display discharge between the scan electrode Y and the sustain electrode Z whenever the sustain pulse sus is applied as the wall voltage and the sustain pulse sus are added. This will happen. The sustain pulse sus has a pulse width of about 2 to 3 ㎲ so that the discharge can be stabilized. It is discharged within approximately 0.5 to 1 시점 after the time when the sustain pulse (sus) is generated, but the sustain pulse (sus) after the discharge to form a wall charge to the extent that can cause the next discharge, This is because the sustain voltage (Vs) should be maintained at about 2 to 3 mA.

After the sustain discharge is completed, ramp waveforms having a small pulse width and a low voltage level are supplied to the sustain electrode Z to erase wall charges remaining in the cells of the full screen.

In the PDP according to the related art as described above, the address period takes the longest during one frame, and the addressing driving time becomes longer as the number of lines increases. For this reason, the driving method of the PDP according to the related art has a disadvantage in that the number of subfields is limited during one frame, which causes a deterioration in image quality.

Accordingly, it is an object of the present invention to provide a method of driving a PDP in which a cell area is reduced by using opposite discharge.

Another object of the present invention is to provide a method of driving a PDP that can reduce an address period.

1 is a plan view schematically showing an electrode arrangement of a conventional three-electrode AC surface discharge type plasma display panel.

2 is a diagram illustrating a frame configuration of an 8-bit default code for implementing 256 gray levels.

3 is a waveform diagram showing a drive waveform for driving a conventional PDP.

4 is a diagram schematically illustrating an electrode arrangement of a plasma display panel according to an exemplary embodiment of the present invention.

FIG. 5 is a diagram illustrating a frame configuration for implementing image gray scale in the plasma display panel illustrated in FIG. 4.

FIG. 6 is a diagram illustrating a driving waveform of the PDP according to the subfield arrangement shown in FIG. 5.

In order to achieve the above object, a plasma display panel driving method according to an embodiment of the present invention includes a plurality of subfields in one field, and a driving method of a plasma display panel including scan electrodes and address electrodes for generating a discharge. And setting two subfields to one discharge period, resetting discharge of the odd-numbered discharge cells by a reset pulse on the odd-numbered scan line of the first subfield, and Causing an address discharge of an odd-numbered discharge cell by a scan pulse applied to an odd-numbered scan line and a data pulse applied to the address electrode, and a data pulse and the even-numbered data applied to the address electrode of the first subfield; Even-numbered second due to the sustain pulse applied to the scan line alternately with the data pulse Characterized in that it comprises a step that causes a sustain discharge in all cells.

According to an exemplary embodiment of the present invention, a reset discharge of an even-numbered discharge cell is performed by a reset pulse on an even-numbered scan line of a second subfield; Generating an address discharge of the even-numbered discharge cell by the applied data pulse, and sustaining the data pulse applied to the address electrode of the second subfield and the sustain pulse applied to the odd-numbered scan line alternately with the data pulse. It further comprises the step of causing a discharge.

The reset pulse applied during the reset discharge in the present invention is characterized in that it has any one of a narrow pulse and a ramp pulse.

In the present invention, while the reset pulse is applied to the odd scan line of the first subfield, the base voltage level is maintained on the even scan line and the address electrode, and the reset pulse is applied to the even scan line of the second subfield. The base voltage level is maintained at the odd-numbered scan line and the address electrode while is applied.

The data pulse in the present invention is characterized by being applied at a lower voltage than the sustain pulse with a difference equal to or less than that of the sustain pulse.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 4 to 6.

4 schematically illustrates a PDP according to an embodiment of the present invention.

Referring to FIG. 4, the discharge cell of the PDP according to the embodiment of the present invention has a two-electrode alternating current counter discharge type structure including a scan electrode Y and an address electrode X orthogonal to the scan electrode Y. .

At the intersection of the scan electrode Y and the address electrode X, a cell 31 for displaying any one of red, green and blue is formed. The scan electrode Y is formed on an upper substrate (not shown). On the upper substrate, a dielectric layer and an MgO protective layer (not shown) are stacked. The address electrode X is formed on the lower substrate (not shown). On the lower substrate, partition walls are formed to prevent optical and electrical interference between horizontally adjacent cells. The partition wall is formed in a stripe shape so as to alternate with the address electrode (X). Phosphors are excited on the lower substrate and the partition walls to be excited by vacuum ultraviolet rays and emit visible light. An inert mixed gas such as He + Xe, Ne + Xe, He + Xe + Ne is injected into the discharge space between the upper substrate and the lower substrate. As described above, in the PDP configuration, the discharge cell can reduce the cell area and increase the resolution by using opposite discharge instead of surface discharge.

In order to realize the gray level of the image, the PDP is time-divisionally driven by dividing one frame into several subfields having different emission counts as shown in FIG. Each subfield is divided into an erasing period for initializing the entire screen or erasing residual wall charges, and an address and sustain period for selecting a scan line, selecting a cell from the selected scan line, or implementing gray levels according to the number of discharges.

At this time, the odd-numbered scan line Y2m-1 and the even-numbered scan line Y2m are driven so that addressing and sustain alternate with each other. That is, the even-numbered scan line Y2m performs an address scan while the odd-numbered scan line Y2m-1 performs sustain discharge. In general, since the time used for the address is longer than the time used for the sustain discharge, the odd-numbered scan line Y2m-1 waits for the address scan to end on the even-numbered scan line Y2m at the end of the sustain discharge. Next, after the address scan of the even-numbered scan line Y2m is finished, the odd-numbered scan line Y2m-1 turns off the discharge cells that were on through erase discharge. In the next subfield, the even scan line Y2m-1 is configured to perform an address scan while the even scan line Y2m performs sustain discharge.

As described above, the spatial resolution is increased without increasing the number of lines to be scanned when driving the PDP. In addition, since a part of the address period is shortened as compared to the ADS method of the prior art, it is possible to save time and to use it in other parts such as the sustain period, thereby reducing power consumption and improving luminous luminance.

FIG. 6 is a diagram illustrating a driving waveform of the PDP according to the subfield arrangement shown in FIG. 5.

Referring to FIG. 6, the PDP according to the present invention is an erase period for initializing a full screen or erasing wall charge remaining in a discharge cell by driving a previous subfield, selecting a cell, or maintaining a discharge of a selected cell. The operation is divided into an address period and a sustain period. In particular, FIG. 6 illustrates a case where an address scan enters an odd-numbered scan line Y2m-1 first and a sustain discharge occurs in an even-numbered scan line Y2m.

First, in the first subfield SF1, the odd-numbered scan line Y2m-1 includes an erase period and an address period, and the even-numbered scan line Y2m corresponds to the address period of the odd-numbered scan line Y2m-1. It consists only of the sustain period performed in the corresponding period.

In the erase period of the odd-numbered scan line Y2m-1, a narrow pulse or an erase pulse EP is applied to the odd-numbered scan line Y2m-1 to initialize the discharge cell. At this time, the erasing period may be erased by self-erasing after generating a strong discharge. At this time, since the even-numbered scan line Y2m is maintained at the same potential as the address electrode X, the addressed wall charge state does not change.

In the address period of the odd-numbered scan line Y2m-1, the negative scan pulse SP is sequentially applied to the odd-numbered scan line Y2m-1, and at the same time, the first voltage level Vd1 is applied to the address electrodes X. Alternatively, the positive data pulse DP of the second voltage level Vd2 higher than the first voltage level Vd1 is applied. The address discharge is generated in the cell to which the scan pulse DP is applied by the voltage difference between the scan pulse SP and the data pulse DP. In the cells selected by the address discharge, wall charges are formed such that a discharge can occur when a sustain voltage is applied.

During the sustain period of the even-numbered scan line Y2m, the sustain pulse SUSP and the first voltage level Vd1 or the second voltage level Vd2 are alternately applied to the even-numbered scan line Y2m and the address electrodes X. The data pulse DP of is applied. Here, the data pulse DP is used as another sustain pulse SSUS. Thus, the cell selected by the address discharge in the previous subfield is added between the even-numbered scan line Y2m and the address electrode line X every time the sustain pulse SSUS is applied while the wall voltage and the sustain pulse in the cell are added. Sustain discharge, or display discharge, occurs. Sustain pulse (SUSP) has a pulse width of about 2 to 3 ㎲ so that discharge can be stabilized. This is caused by discharge within approximately 0.5 to 1 kW since the time when the sustain pulse (SUSP) is generated, but since the sustain pulse (SUSP) is discharged to form a wall charge to the extent that can cause the next discharge, This is because the sustain voltage (Vs) should be maintained at about 2 to 3 mA.

In the above drive, since the sustain period is shorter than the address period, it takes time until the address period ends after the sustain period. Therefore, the PDP driving method according to the present invention can reduce the address period by the number of sustain pulses. That is, when 100 sustain pulses are applied with a width of about 2 to 3 ms, an address time of about 200 to 300 ms can be reduced.

In the next subfield SF2, the odd-numbered scan line Y2m-1 is composed only of the sustain period, and the even-numbered scan line Y2m is composed of the erase period and the address period.

In the erase period of the even-numbered scan line Y2m, a narrow pulse or an erase pulse EP is applied to the even-numbered scan line Y2m to initialize the discharge cell. At this time, the erasing period may be erased by self-erasing after generating a strong discharge. At this time, since the odd-numbered scan line Y2m-1 is maintained at the same potential as that of the address electrode X, the addressed wall charge state does not change.

In the address period of the even-numbered scan line Y2m, the negative scan pulse SP is sequentially applied to the even-numbered scan line Y2m and at the same time, the first voltage level Vd1 or the second voltage is applied to the address electrodes X. A positive data pulse DP of level Vd2 is applied. The address discharge is generated in the cell to which the scan pulse DP is applied by the voltage difference between the scan pulse SP and the data pulse DP. In the cells selected by the address discharge, wall charges are formed such that a discharge can occur when a sustain voltage is applied.

In the sustain period of the odd-numbered scan line Y2m-1, the sustain pulse SUSP and the first voltage level Vd1 or the first voltage are alternately applied to the odd-numbered scan line Y2m-1 and the address electrodes X. The data pulse DP of the second voltage level Vd2 higher than the level Vd1 is applied. Here, the data pulse DP is used as another sustain pulse SSUS. As a result, in the cell selected by the address discharge in the previous subfield, the wall voltage and the sustain pulse in the cell are added, and the odd-numbered scan line Y2m-1 and the address electrode line X are applied every time the sustain pulse SSUS is applied. Sustain discharge, that is, display discharge, occurs between them. Sustain pulse (SUSP) has a pulse width of about 2 to 3 ㎲ so that discharge can be stabilized. This is caused by discharge within approximately 0.5 to 1 kW since the time when the sustain pulse (SUSP) is generated, but since the sustain pulse (SUSP) is discharged to form a wall charge to the extent that can cause the next discharge, This is because the sustain voltage (Vs) should be maintained at about 2 to 3 mA.

In the above drive, since the sustain period is shorter than the address period, it takes time until the address period ends after the sustain period. Therefore, the PDP driving method according to the present invention can reduce the address period by the number of sustain pulses. That is, when 100 sustain pulses are applied with a width of about 2 to 3 ms, an address time of about 200 to 300 ms can be reduced.

As described above, the driving method of the PDP according to the present invention arranges the scan electrodes on the upper plate and the address electrodes on the lower plate in a matrix form, sets two subfields to one discharge period, and even-numbered and odd-numbered scan lines. Is driven so that the erase, address period and sustain period are alternated for each subfield. As a result, the driving method of the PDP according to the present invention can reduce the driving time by the number of sustain pulses, so that higher luminance can be obtained when the reduced time is utilized for sustain discharge. In addition, when the number of subfields is increased, the deterioration of image quality due to the video implementation may be reduced.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (5)

A driving method of a plasma display panel including a plurality of subfields in one field and having scan electrodes and address electrodes for generating a discharge, the method comprising: Setting two subfields to one discharge period, Resetting discharge of the odd-numbered discharge cell by the reset pulse in the odd-numbered scan line of the first subfield; Causing an address discharge of an odd-numbered discharge cell by a negative scan pulse applied to the odd-numbered scan line of the first subfield and a positive data pulse applied to the address electrode; Causing sustain discharge of even-numbered discharge cells by positive data pulses applied to the address electrodes of the first subfield and positive sustain pulses applied alternately to the data pulses on the even-th scan line; A driving method of a plasma display panel, characterized in that. The method of claim 1, Resetting discharge of the even-numbered discharge cell by the reset pulse to the even-numbered scan line of the second subfield; Causing an address discharge of an even-numbered discharge cell by a negative scan pulse applied to the even-numbered scan line of the second subfield and a positive data pulse applied to the address electrode; And causing sustain discharge by positive data pulses applied to the address electrodes of the second subfield and positive sustain pulses applied alternately to the data pulses in the odd scan line. How to drive the panel. The method of claim 2, The reset pulse applied during the reset discharge, A driving method of a plasma display panel having any one of a narrow pulse and a ramp pulse. The method of claim 1, While a reset pulse is applied to the odd scan line of the first subfield, a ground voltage level is maintained at the even scan line and the address electrode. And a base voltage level is maintained at the odd scan line and the address electrode while a reset pulse is applied to the even scan line of the second subfield. The method of claim 1, And the data pulses are applied at a voltage lower than the sustain pulses with a difference equal to or less than that of the sustain pulses.