KR20040090583A - Method And Apparatus Of Driving Plasma Display Panel - Google Patents

Abstract

PURPOSE: A method for driving a plasma display panel and an apparatus thereof are provided to improve gray level expression by forming a scan driving unit and a sustain driving unit at least two blocks. CONSTITUTION: According to the apparatus for driving a plasma display panel, the first scan driving unit(112a) drives odd-numbered scan electrode lines(Y1-Ym-1). The second scan driving unit(112b) drives even-numbered scan electrode lines(Y2-Ym). The first common sustain driving unit(114a) drives odd-numbered sustain electrode lines(Z1-Zm-1). The second common sustain driving unit(114b) drives even-numbered sustain electrode lines(Z2-Zm). And a X driving unit(116) drives n address electrode lines(X1-Xn).

Description

Method and apparatus for driving plasma display panel {Method And Apparatus Of 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 and apparatus for driving a plasma display panel capable of improving gray scale expression.

Plasma Display Panel (hereinafter referred to as "PDP") is characterized by emitting phosphors by 147nm ultraviolet rays generated when discharge of inert gas such as He + Xe, Ne + Xe and He + Ne + Xe. An image containing graphics is displayed. Such a PDP is not only thin and easy to enlarge, but also greatly improved in quality due to recent technology development. In particular, the three-electrode AC surface discharge type PDP has advantages of low voltage driving and long life because wall charges are accumulated on the surface during discharge and protect the electrodes from sputtering caused by the discharge.

Referring to FIG. 1, a discharge cell of a three-electrode AC surface discharge type PDP includes a scan electrode Y and a sustain electrode Z formed on the upper substrate 10, and an address electrode formed on the lower substrate 18. X). Each of the scan electrode Y and the sustain electrode Z has a line width smaller than that of the transparent electrodes 12Y and 12Z and the transparent electrodes 12Y and 12Z, and the metal bus electrode 13Y is formed at one edge region of the transparent electrode. , 13Z).

The transparent electrodes 12Y and 12Z are usually formed on the upper substrate 10 by indium tin oxide (hereinafter, referred to as “ITO”). The metal bus electrodes 13Y and 13Z are usually formed of metals such as chromium (Cr) and formed on the transparent electrodes 12Y and 12Z to reduce voltage drop caused by the transparent electrodes 12Y and 12Z having high resistance. The upper dielectric layer 14 and the passivation layer 16 are stacked on the upper substrate 10 having the scan electrode Y and the sustain electrode Z side by side. In the upper dielectric layer 14, wall charges generated during plasma discharge are accumulated. The protective layer 16 prevents damage to the upper dielectric layer 14 due to sputtering generated during plasma discharge and increases emission efficiency of secondary electrons. As the protective film 16, magnesium oxide (MgO) is usually used. The lower dielectric layer 22 and the partition wall 24 are formed on the lower substrate 18 on which the address electrode X is formed, and the phosphor layer 26 is coated on the surfaces of the lower dielectric layer 22 and the partition wall 24. The address electrode X is formed in the direction crossing the scan electrode Y and the sustain electrode Z. The partition wall 24 is formed in parallel with the address electrode X to prevent ultraviolet rays and visible light generated by the discharge from leaking to the adjacent discharge cells. The phosphor layer 26 is excited by ultraviolet rays generated during plasma discharge to generate visible light of any one of red, green, and blue. An inert mixed gas such as He + Xe, Ne + Xe, and He + Ne + Xe for discharging is injected into the discharge space of the discharge cells provided between the upper and lower substrates 10 and 18 and the partition wall 24.

The three-electrode AC surface discharge type PDP is driven by dividing one frame into several subfields having different emission counts in order to realize gray levels of an image. Each subfield is further divided into a reset period for uniformly generating discharge, an address period for selecting a discharge cell, and a sustain period for implementing gray levels according to the number of discharges. For example, when the image is to be displayed in 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. In addition, each of the eight subfields SF1 to SF8 is divided into a reset and an address period and a sustain period. Here, the reset and address periods of each subfield are the same for each subfield, while the sustain period increases at a rate of 2 ⁿ (n = 0,1,2,3,4,5,6,7) in each subfield. do. As described above, since the sustain period is changed in each subfield, gray levels of an image can be realized.

3 is a waveform diagram illustrating a method of driving a PDP according to the prior art.

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 applied to all the scan electrodes Y simultaneously. This rising ramp waveform (Ramp-up) causes a slight discharge in the cells of the full screen to generate wall charges in the cells. During the set down period, after the rising ramp waveform Ramp-up is supplied, the falling ramp waveform Ramp-down falling at the positive voltage lower than the peak voltage of the rising ramp waveform Ramp-up is applied to the scan electrodes Y. It is applied at the same time. Ramp-down generates weak erase discharges in the cells, thereby eliminating unnecessary charges during wall charges and space charges generated by setup discharges, and uniformly distributing the wall charges required for address discharges in the cells of the full screen. Will remain.

In the address period, a negative scan pulse scan is sequentially applied to the scan electrodes Y, and a positive data pulse data is applied to the address electrodes X. As the voltage difference between the scan pulse and the data pulse and the wall voltage generated in the initialization period are added, an address discharge is generated in the cell to which the data pulse is applied. Wall charges are generated in the cells selected by the address discharge.

On the other hand, the positive electrode DC voltage of the sustain voltage level Vs is supplied to the sustain electrodes Z 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. Then, the cell selected by the address discharge is sustained in the form of surface discharge between the scan electrode Y and the sustain electrode Z each time the sustain pulse sus is applied while the wall voltage and the sustain pulse sus in the cell are added. Discharge occurs. Finally, after the sustain discharge is completed, an erase ramp waveform (erase) having a small pulse width is supplied to the sustain electrode Z to erase wall charges in the cell.

4 is a view showing a driving apparatus of a plasma display panel according to a conventional method.

Referring to FIG. 4, a PDP driving apparatus drives a scan driver 12 for driving _m scan electrode lines Y ₁ to Y _m and m common sustain electrode lines Z ₁ to Z _m . And a sustain driver 14 for driving the n address electrode lines X ₁ to X _n .

The scan driver 12 initializes the full screen by supplying setup / down waveforms (Ramp-up, Ramp-down) in each subfield in the initialization period, and applies a scan pulse (Scan) in the address period to the upper scan electrode lines. It is supplied to (Y ₁ to Y _m ) sequentially. In addition, the scan driver 12 supplies sustain pulses (sus) in the subfield to cause sustain discharge.

A sustain driving unit 14 serves to the sustain electrode lines are commonly connected to a (Z ₁ to Z _m) to the sustain electrode lines (Z ₁ to Z _m), a direct current voltage and sustain pulses (sus) scanning to supply sequentially do.

The address driver 16 supplies a data pulse data to the address electrode lines X ₁ to Xn to be synchronized with the scan pulse scan.

In such a PDP, the reset and address periods of each subfield are the same for each subfield, while the sustain period is 2 ⁿ (n = 0,1,2,3,4,5,6,7) of each subfield. Is increased in proportion. As described above, since the sustain period is changed in each subfield, gray levels of an image can be realized. However, there is a limit in expressing the gray scale in this way. Accordingly, there is a demand for a method capable of improving gradation.

Accordingly, an object of the present invention is to provide a method and apparatus for driving a plasma display panel to improve gray scale expression.

1 is a perspective view showing a discharge cell structure of a conventional three-electrode AC surface discharge type plasma display panel.

2 is a diagram showing a frame structure of an 8-bit default code for implementing 256 gray scales.

3 is a waveform diagram showing a method of driving a plasma display panel according to a conventional method.

4 is a view showing a driving device of a plasma display panel according to a conventional method.

5 is a diagram illustrating a driving device of a plasma display panel according to a first embodiment of the present invention.

6A to 6C are views showing an increase in gray scale expression according to the driving device shown in FIG.

FIG. 7 is a diagram illustrating a case in which different sustain pulses are alternately provided for each frame in the first embodiment of the present invention. FIG.

8 is a view showing a driving apparatus for a plasma display panel according to a second embodiment of the present invention;

9A to 9F are views showing an increase in gray scale expression according to the driving device shown in FIG.

<Description of Symbols for Main Parts of Drawings>

10: upper substrate 18: lower substrate

Y: scan electrode Z: sustain electrode

X: address electrode 12Y, 12Z: transparent electrode

13Y, 13Z: metal bus electrode 14: upper dielectric layer

16: protective film 22: lower dielectric layer

24: partition 26: phosphor layer

12,112a, 112b, 212a, 212b, 212c, 212d: Scan driver

14,114a, 114b, 214a, 214b, 214c, 214d: Sustain drive section

16,116,216: address driver

In order to achieve the above object, a method of driving a plasma display panel according to an embodiment of the present invention comprises the steps of separating the sustain electrode pairs into at least two sustain electrode groups, and sustain pulses having different numbers of sustain pulse groups. It includes the step of being supplied.

The sustain electrode groups are supplied with the same number of sustain pulses.

The sustain electrode pairs are divided into odd sustain electrode groups and even sustain electrode groups.

The odd and even sustain electrode groups may be supplied with different numbers of sustain pulses.

A first number of sustain pulses are supplied to the odd sustaining electrode groups, and a second number of sustain pulses different from the first number is supplied to the even sustaining electrode groups in an n (n is natural number) frame. And a third number of sustain pulses different from the first and second numbers is supplied to the odd sustain electrode groups in an n + 1th frame, and a fourth number different from the third number is supplied to the even sustain electrode groups. It is characterized in that it further comprises the step of supplying a number of sustain pulses.

In the method of driving a plasma display panel according to an embodiment of the present invention, the sustain electrode pairs formed on the upper side are separated into at least two sustain electrode groups, and the sustain electrode pairs formed on the lower side are at least two sustain electrode groups. And a step of supplying a different number of sustain pulses to the upper sustain electrode groups, and a step of supplying a different number of sustain pulses to the lower sustain electrode groups.

The sustain electrode groups are supplied with the same number of sustain pulses.

The upper sustain electrode pairs may be divided into an odd sustain electrode group and an even sustain electrode group.

The lower sustain electrode pairs are separated into an odd sustain electrode group and an even sustain electrode group.

A first number of sustain pulses is supplied to the odd sustain electrode group on the upper side, and a second number of sustain pulses different from the first number is supplied to the even sustain electrode group on the upper side, and an odd sustain electrode group on the lower side. And a third number of sustain pulses is supplied to the lower even-numbered sustain electrode group, and a fourth number of sustain pulses different from the third number is supplied.

The first number and the third number are the same number.

The second number and the fourth number is characterized in that the same number.

The first number and the third number may be different from each other.

The second number and the fourth number may be different from each other.

A different number of sustain pulses are supplied to each of the sustaining electrode groups of the n-th frame, and a different number of sustain pulses than the sustain pulses supplied to each of the sustaining electrode groups of the n-th frame are n + 1th times. And differently supplied to each sustain electrode group of the frame.

An apparatus for driving a plasma display panel according to an exemplary embodiment of the present invention includes a first scan driver for supplying a first number of sustain pulses to even scan electrodes, and a second number different from the first number to odd scan electrodes. A second scan driver for supplying sustain pulses, a first sustain driver for supplying the first number of sustain pulses to even sustain electrodes, and a second number of sustain pulses for supplying odd sustain electrodes A second sustain drive unit is provided.

According to an exemplary embodiment of the present invention, a driving apparatus of a plasma display panel may include driving a scan driver for driving i (i is a natural number) scan electrodes and driving the i sustain electrodes, respectively. J sustain drivers are provided, and the scan drivers supply different numbers of sustain pulses to the i scan electrodes, respectively.

The sustain driver supplies different numbers of sustain pulses to the i sustain electrodes, respectively.

The scan electrodes and the sustain electrodes formed on the same discharge cell are supplied with the same number of sustain pulses.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 5 to 9F.

5 is a diagram illustrating a driving apparatus of a plasma display panel according to a first embodiment of the present invention.

Referring to FIG. 5, a driving apparatus of a PDP according to the first embodiment of the present invention includes a first scan driver 112a and an even scan electrode line for driving odd scan electrode lines Y ₁ to Y _{m -1} . The second scan driver 112b for driving (Y ₂ to Y _m ), the first common sustain driver 114a for driving the odd sustain electrode lines Z ₁ to Z _{m -1} , and the even sustain electrode A second common sustain driver 114b for driving the lines Z ₂ to Z _m and an X driver 116 for driving the _n address electrode lines X ₁ to X _n are provided.

The first and second scan drivers 112a and 112b initialize the full screen by supplying a setup / down waveform in the initialization period in each subfield, and scan scan pulses in the address period during the odd scan electrode lines (Y ₁ to Y). _m-1 ) and even scan electrode lines (Y ₂ to Y _m ) are sequentially supplied. In addition, the first and second scan drivers 112a supply a sustain pulse to the subfield to cause sustain discharge. At this time, the number of sustain pulses supplied from the first and second scan drivers 112a and 112b is set differently from each other.

The first and second common sustain drivers 114a and 114b are connected to the odd common sustain electrode lines Z ₁ to Z _{m -1} and the even common sustain electrode lines Z ₂ to Z _m , and thus the odd common sustain electrodes. It serves to sequentially supply the scan DC voltage and the sustain pulse to the lines Z ₁ to Z _{m -1} and the even common sustain electrode lines Z ₂ to Z _m . At this time, the number of sustain pulses supplied from the first and second common sustain drivers 114a and 114b are set differently from each other.

The address driver 116 supplies data pulses to the address electrode lines X ₁ to X _n to be synchronized with the scan pulses.

At this time, the number of sustain pulses supplied from the first scan driver 112a and the first common sustain driver 114a is set equal. In addition, the number of sustain pulses supplied from the second scan driver 112b and the second common sustain driver 114b is set equal.

In detail, the scan drive unit and the sustain driver which supply the sustain pulses are blocked by two blocks to supply different numbers of sustain pulses. That is, as shown in FIG. 6A, the first number of sustain pulses supplied from the first scan driver 212a to the odd electrode lines Y ₁ to Y _{m -1} and Z ₁ to Z _{m -1} may be used. You can express gradation. As shown in FIG. 6B, the second scan driver 212b uses a second number of sustain pulses different from the first number supplied to the even electrode lines Y ₂ to Y _m and Z ₂ to Z _m . You can express the gradation of. Also, as shown in FIG. 6C, the gray level of T3, which is an intermediate gray level of T1 and T2, may also be expressed. Thus, since different numbers of sustain pulses are supplied from the first and second scan drivers 212a and 212b, the gray scales can be expressed, thereby improving gray scale expression.

For example, 100 sustain pulses are supplied from the first scan driver 212a to the odd electrode lines Y ₁ to Y _{m -1} and Z ₁ to Z _{m -1} , and the second scan driver 212b is provided. Assume that 90 sustain pulses are supplied to even electrode lines (Y ₂ to Y _m and Z ₂ to Z _m ). Since not only the T1 gradation of FIG. 6A represented by 100 sustain pulses and the T2 gradation of FIG. 6B represented by 90 sustain pulses, but also the T3 gradation of FIG. 6C represented by its intermediate value can be expressed. will be. At this time, the scan driver and the sustain driver may block at least two or more to supply different numbers of sustain pulses.

Meanwhile, as shown in FIG. 7, a first number of sustain pulses are supplied to odd electrode lines in an n (n is a natural number) frame, and a second number of sustain pulses different from the first number are supplied to even electrode lines. Supply. In the n + 1 th frame, a third number of sustain pulses different from the first and second numbers is supplied to the odd electrode lines, and a fourth number of sustain pulses different from the third number is supplied to the even electrode lines. In this way, more gray levels can be expressed by supplying different numbers of sustain pulses to odd and even electrode lines for each frame.

For example, if the 100 sustain pulses are supplied to the odd electrode lines of the n-th frame and the 90 sustain pulses are supplied to the even electrode lines, the odd-electrodes of the n + 1th frame 80 sustain pulses are supplied to the lines, and 70 sustain pulses are supplied to the even electrode lines. In this way, different numbers of sustain pulses are supplied alternately for each frame to further improve gray scale expression.

8 is a diagram illustrating a driving apparatus of a plasma display panel according to a second embodiment of the present invention.

Referring to FIG. 8, the driving apparatus of the PDP according to the second embodiment of the present invention includes a first scan driver 212a and a first common sustain driver for driving odd scan electrode lines and odd sustain electrode lines on the upper side. 214a, the second scan driver 212b and the second common sustain driver 212b for driving the even scan electrode lines and the even sustain electrode lines on the upper side, and the odd scan electrode lines and the odd number on the lower side. A third scan driver 212c and a third common sustain driver 214c for driving the sustain electrode lines, a fourth scan driver 212d for driving the even scan electrode lines and the even sustain electrode lines on the lower side, and The fourth common sustain driver 214d is provided.

The first to fourth scan drivers 212a, 212b, 212c and 212d initialize the full screen by supplying a setup / down waveform in an initialization period in each subfield, and scan pulses in the address period, respectively. Will be supplied sequentially. In addition, the first to fourth scan drivers 212a, 212b, 212c, and 212d generate a sustain discharge by supplying a sustain pulse to the subfield. At this time, the number of sustain pulses supplied from the first and second scan drivers 212a and 212b on the upper side is set different from each other. In addition, the number of the sustain pulses supplied from the third and fourth scan drivers 212c and 212d on the lower side is set different from each other.

The first to fourth common sustain drivers 214a, 214b, 214c, and 214d are connected to the respective sustain electrode lines to sequentially supply the scan DC voltage and the sustain pulse to the sustain electrode lines. At this time, the number of sustain pulses supplied from the first and second common sustain drivers 214a and 214b on the upper side is set differently from each other. In addition, the number of sustain pulses supplied from the third and fourth common sustain drivers 214c and 214d on the lower side is set different from each other.

The address driver 216 supplies data pulses to the address electrode lines X ₁ to X _n to be synchronized with the scan pulse.

At this time, the number of sustain pulses supplied from the first scan driver 212a and the first common sustain driver 214a, and the number of sustain pulses supplied from the second scan driver 212b and the second common sustain driver 214b. The number of sustain pulses supplied from the third scan driver 212c and the third common sustain driver 214c and the number of sustain pulses supplied from the fourth scan driver 212d and the fourth common sustain driver 214d are the same. Is set to.

In detail, at least two of the scan driver and the sustain driver for supplying the sustain pulses are blocked on the upper and lower sides to supply different numbers of sustain pulses to the corresponding electrode lines. In other words, the scan driver on the upper side and the sustain driver are divided into at least two or more, and different sustain pulses are supplied to the electrode lines. That is, the gray level of T1 may be expressed by the first number of sustain pulses supplied from the first scan driver 212a and the first common sustain driver 214a to the upper odd electrode line as shown in FIG. 9A. As shown in FIG. 9B, the gray level of T2 is caused by a second number of sustain pulses different from the first number supplied to the upper even electrode lines from the second scan driver 212b and the second common sustain driver 214b. Can be expressed. In addition, as illustrated in FIG. 9C, the gray level of T3, which is an intermediate gray level of T1 and T2, may also be expressed. Thus, since different numbers of sustain pulses are supplied from the first and second scan drivers 212a and 212b, even gray scales can be expressed, thereby improving gray scale expression.

Meanwhile, the gray level of T4 may be expressed by the third number of sustain pulses supplied from the third scan driver 212c and the third common sustain driver 214c to the lower odd electrode line. As shown in FIG. 9E, the grayscale of T5 is applied by a fourth number of sustain pulses different from the third number supplied from the fourth scan driver 212d and the fourth common sustain driver 214d to the lower even electrode line. Can be expressed. In addition, as illustrated in FIG. 9F, the gray level of T6, which is an intermediate gray level of T4 and T5, may also be expressed. Thus, since different numbers of sustain pulses are supplied from the third and fourth scan drivers 212c and 212d, the gray scales can be expressed, thereby improving gray scale expression.

In this case, the upper side and the lower side may be driven separately, and the upper side and the lower side may be divided into at least two scan drivers and a sustain driver to supply different sustain pulses. That is, the first number, the third number, the second number and the fourth number of sustain pulses may be the same number or may be different from each other.

As described above, the method and apparatus for driving a plasma display panel according to the present invention block the scan driver and the sustain driver by at least two, and then supply different numbers of sustain pulses to the scan and sustain electrode lines. It can express gradation and can improve gradation expression.

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 (19)

In the driving method of a plasma display panel having a sustain electrode pair formed for each discharge cell, Separating the sustain electrode pairs into at least two sustain electrode groups; And supplying different numbers of sustain pulses to the sustain electrode groups. The method of claim 1, The sustain electrode group is supplied with the same number of sustain pulses driving method of the plasma display panel. The method of claim 1, The sustain electrode pairs are separated into odd sustain electrode groups and even sustain electrode groups. The method of claim 3, wherein And a different number of sustain pulses are supplied to the odd and even sustain electrode groups. The method of claim 4, wherein A first number of sustain pulses are supplied to the odd sustaining electrode groups, and a second number of sustain pulses different from the first number is supplied to the even sustaining electrode groups in an n (n is natural number) frame. Steps, A third number of sustain pulses different from the first and second numbers is supplied to the odd sustain electrode groups in an n + 1th frame, and a fourth number of sustain points different from the third number is supplied to the even sustain electrode groups. The method of driving a plasma display panel further comprising the step of supplying a pulse. In the method of driving a plasma display panel in which the panel is separated and driven to the upper side and the lower side, Separating the sustain electrode pairs formed on the upper side into at least two sustain electrode groups; Separating the sustain electrode pairs formed on the lower side into at least two sustain electrode groups; Supplying different numbers of sustain pulses to the sustain electrode groups on the upper side; And supplying different numbers of sustain pulses to the sustain electrode groups on the lower side. The method of claim 6, The sustain electrode group is supplied with the same number of sustain pulses driving method of the plasma display panel. The method of claim 6, And the sustain electrode pairs on the upper side are separated into an odd sustain electrode group and an even sustain electrode group. The method of claim 6, And the sustain electrode pairs on the lower side are separated into an odd sustain electrode group and an even sustain electrode group. The method according to claim 8 or 9, A first number of sustain pulses are supplied to the odd-numbered sustaining electrode groups on the upper side, A second number of sustain pulses different from the first number is supplied to the even sustain electrode group on the upper side, A third number of sustain pulses is supplied to the lower sustain electrode group; And a fourth number of sustain pulses different from the third number is supplied to the even-numbered sustaining electrode groups on the lower side. The method of claim 10, And the first number and the third number are the same number. The method of claim 10, And the second number and the fourth number are the same number. The method of claim 10, And the first number and the third number are different numbers from each other. The method of claim 10, And the second number and the fourth number are different numbers from each other. The method of claim 10, supplying a different number of sustain pulses to each of the sustain electrode groups of the nth frame (n is a natural number); And driving sustain pulses different from the sustain pulses supplied to each sustain electrode group of the nth frame to the sustain electrode groups of the n + 1th frame. Way. A first scan driver for supplying a first number of sustain pulses to the even scan electrodes; A second scan driver for supplying a second number of sustain pulses different from the first number to odd scan electrodes; A first sustain driver for supplying the first number of sustain pulses to even sustain electrodes; And a second sustain driver for supplying the second number of sustain pulses to the odd sustain electrodes. j (j is a natural number less than i) scan drivers for driving i (i is a natural number) scan electrodes, respectively J sustain elements for driving the i sustain electrodes, respectively; And the scan drivers supply different numbers of sustain pulses to the i scan electrodes, respectively. The method of claim 17, And the sustain driver supplies different numbers of sustain pulses to the i sustain electrodes, respectively. The method of claim 18, And the scan electrodes and the sustain electrodes formed on the same discharge cell are supplied with the same number of sustain pulses.