KR19980035146A - AC plasma display device (AC PDP) driving method using phase difference method and circuit and PDP panel - Google Patents

Abstract

The present invention utilizes a phase difference between a data input pulse and a scan pulse in an AC plasma display device having a three-electrode surface discharge structure. The data input speed is also related to an AC PDP driving method, a circuit thereof, and a PDP panel that can be doubled.

To this end, the present invention provides a three-electrode surface discharge AC PDP in which each cell is composed of two row electrodes and one column electrode, wherein the row electrodes are divided into upper and lower groups of the screen, and the driving pulses applied to the respective groups. Difference in phase difference by 1/2 period of sustain pulse to reduce the time required for full screen scanning by 1/2, also apply data pulses to column electrodes, and row electrodes apply common sustain pulses only. The electrodes are separated into scan electrodes to which the sustain, scan, and erase pulses are applied together, and the phase between the scan pulses at the top and bottom of the screen is separated by 1/2 of the sustain pulse so that the time required for the full screen scan is 1 /. It was reduced to 2.

Description

AC plasma display device (AC PDP) driving method using phase difference method and circuit and PDP panel

1 is a structural diagram of a typical three-electrode surface discharge AC PDP cell.

2 is an electrode layout of a typical three-electrode surface discharge AC PDP.

3 is a driving waveform diagram using an electrode arrangement of a typical three-electrode AC PDP.

4 is a basic driving waveform diagram used in a typical AC PDP.

5 is a basic drive waveform diagram for using the phase difference method of data and scan pulses according to the present invention.

6 is an electrode arrangement diagram of an AC PDP for applying FIG. 5. FIG.

7 is an overall waveform diagram of drive pulses for applying FIG.

8 is a schematic diagram of an AC PDP electrode arrangement in which the phase difference method of data and scan pulses can be used in the present invention, wherein the electrodes of the upper and lower groups of the screen are (a); {(S1, C1), (S2, C2)}, (b); {(S1, C1) (C2, S2)}, (c); {(C1, S1) (S2, C2)}, (d); Structure diagram arranged in the order of {(C1, S1) (C2, S2)}.

Explanation of symbols on the main parts of the drawings

1: lower insulation plate 2: upper insulation plate

3: row electrode 4: column electrode

5: lower insulating film 6: upper insulating film

7: protective film 8: discharge space

9: fluorescent film 10: partition wall

11: cell 12: sealing area

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to the driving of a plasma display panel, one of the flat panel displays, and more particularly to data input in an AC plasma display device having a three-electrode surface discharge structure. The present invention relates to an AC PDP driving method, a circuit thereof, and a PDP panel capable of doubling the data input speed without increasing the complexity of the driving device by using a phase difference between a pulse and a scan pulse.

In general, the plasma display device (PDP) is discharged by adjusting the voltage applied between the vertical and horizontal electrodes of the cell (CELL) constituting the pixel, the amount of light discharged changes the length of the discharge time in the cell Adjust it.

The full screen includes write pulses for inputting digital image signals to the vertical and horizontal electrodes of each cell, scan pulses for scanning, sustain pulses for sustaining discharge, and discharged cells. It was obtained by applying an erase pulse for stopping the discharge of the crystal and driving it in a matrix.

The level of gradation (gray level) required for the image display varies the length of time each cell is discharged within a given time (1/30 second for NTSC TV signals) required to display the entire image. It was implemented.

In this case, the brightness of the screen is determined by the brightness when each cell is driven to the maximum, and in order to increase the brightness, the driving time is maintained so that the discharge time of the cell can be kept as long as possible within a given time to compose a screen. The furnace must be designed.

Contrast, which is the difference in contrast, is determined by the brightness and luminance of the background of the lamp, and in order to increase the contrast, not only the background should be dark, but also the luminance needs to be increased.

In the case of a flat-panel display device for a high-definition television (HDTV), 265 gray levels are required, the resolution must be 1280 x 1024 or more, and the contrast under 200 lux lighting needs to be 100: 1 or more.

Therefore, an image digital signal required for 265 gray level image display requires 8-bit signals of R, G, and B, respectively, and the cell discharge time should be kept as long as possible in order to obtain the required luminance and contrast.

The gray level implementation includes a line scanning method and a subfield method. Among the AC PDPs, the most commonly adopted method is the sub-screen method.

In the subfield method, an 8-bit digital video signal is collected from the same weight bits from the most significant bit (MSB) to the least significant bit (LSB), and then the most significant bit (MSB) is represented by time ( During T), the lower bits are scanned for T / 2, T / 4, ..., T / 128 in the order of the bit closest to the most significant bit (MSB), respectively, to form a sub picture, and the light emitted from each sub picture. The 265 gray levels are realized using the integral effect of the eye on the.

However, since PDP must be driven in a matrix method, there is a problem in that write pulses cannot be applied to one or more horizontal electrodes at a time for a given vertical electrode. Therefore, the horizontal electrodes must be driven at different times. .

Therefore, in order to compose each sub-screen, it is necessary to scan all horizontal electrodes, and each cell can maintain the discharge only for a time reduced by the scanning time from the time allocated to the average sub-screen.

The time required for scanning increases as the number of horizontal electrodes increases, and since discharge cannot be maintained during this time, it becomes a factor that causes a decrease in luminance and contrast of the PDP, and thus the time required for scanning needs to be shortened as much as possible. .

FIG. 1 illustrates a three-electrode surface discharge AC PDP cell structure which is generally used today.

The partition wall 10 keeps the secondary insulating plate 1 and the upper insulating plate 2 in parallel and isolates the cells from each other. The row electrodes 3 are composed of a scan electrode, a common electrode, and two common electrodes. (1) They are arranged in parallel with each other from above.

The column electrodes 4 are arranged parallel to each other under the insulating plate 2 to form a matrix with the row electrodes 3.

The lower insulating film 5 and the upper insulating film 6 respectively cover the row electrode 3 and the column electrode 4 to protect the electrode. Since the electrode is covered with the insulating film, a direct current (DC) voltage is applied between the electrodes. When discharged, the discharge is soon extinguished.

In the case of an AC PDP having such an electrode structure, an AC voltage whose polarity is continuously reversed must be applied between electrodes in order to maintain discharge.

The protective film 7 is covered on the lower insulating film 5, and the protective film 7 protects the insulating film 5 to prolong its lifespan, improve the emission efficiency of secondary electrons, and MgO thin film is mainly used to reduce the change of discharge characteristics.

The fluorescent film 9 is coated on the upper insulating film 6, and is excited by ultraviolet rays generated by the discharge to generate red, green, and blue (RGB) visible light.

The discharge space 8 is a space of a cell where discharge is performed, and is mainly filled with a mixture of argon (Ar) and xenon (Xe) in order to increase ultraviolet emission efficiency.

2 shows the electrode arrangement of a typical three-electrode surface discharge AC PDP.

Each cell 11 is formed at a point where the row electrodes and the column electrodes cross at right angles to each other, and the row electrodes maintain a discharge with a scan (S ₁ ~ S _m ) electrode group mainly used for scanning of the screen. It consists of a group of common (C ₁ ~ C _m ) electrodes that are used mainly for giving, and column electrodes are used mainly for data input.

The sealing region 12 is used to maintain the vacuum of the entire PDP, and the partition 10 is formed between the insulating plates 1 and 2 and the edge of the PDP is sealed using a sealing agent.

3 shows a drive waveform diagram used in a typical three-electrode surface discharge AC PDP.

A sustain pulse A is applied to the common electrodes C ₁ to C _m , and the scan electrodes S ₁ to S _m have the same shape as the pulses of the common electrodes. A sustain pulse B with a different position is applied.

Scan pulses used for scanning the screen and erase pulses for stopping the discharge of the discharged cells are additionally input to each of the scan electrodes to control the blinking operation of the cells.

The light pulses are input to the column electrodes D ₁ to D _n by inputting data pulses synchronized with the scan pulses input to the scan electrodes. If a cell (S _1, D ₁₎ in this case is to be discharged forward (Positive) the data pulse is input to the D ₁ and a scan pulse is synchronized with the data pulse is input to the S ₁ when S between the _first electrode and the D _first electrode The discharge voltage is higher than the threshold voltage necessary to cause the discharge.

This state is maintained until the next erase pulse is applied by the electric field generated by the charged particles charged to the insulating film by the discharge and the electric field generated by the sustain pulses of S ₁ and C ₁ , and the amplitude is lower than the scan pulse. When the erase pulse is applied, the sum of the electric field caused by the charged particles and the electric field caused by the erase pulse generates a small discharge which is insufficient to sustain the discharge, and the discharge is extinguished when the next sustain pulse is applied.

When the electrodes described above summarize the roles, the scan electrodes serve as the sustain and the screen scan, while the common electrodes perform the sustain function only.

The data electrodes are responsible for data input for screen configuration.

4 illustrates the voltage difference between the scan electrode and the common electrode when the basic driving waveforms given in FIG. 3 are applied to the cell electrodes.

This waveform is a waveform obtained by integrating the waveform of the scan electrode and inverting the waveform of the scan electrode.

This basic driving waveform has the characteristic that only one scan pulse can be inputted once during one sustain pulse period, so that the scan pulse can be applied only for one half of the sustain pulse.

In order to increase the scan speed, the present invention uses a waveform as shown in FIG.

Compared to the case of FIG. 4, two scan pulses having the same amplitude but different signs are applied to the positive sustain pulse, so that the discharge is generated when the data pulse D coincides with the scan pulse.

When the PDP is driven using such a scan pulse, two scan pulses can be inserted within one sustain pulse period, thereby obtaining a double scan speed.

In order to implement the fundamental waveform of FIG. 5 in the three-electrode surface discharge AC PDP having the structure given in FIG. 1, it is necessary to modify the electrode arrangement shown in FIG.

6 is a modification of the arrangement of the electrodes so that two scan pulses can be inserted in one period of the sustain pulse.

Compared to the electrode arrangement of FIG. 2, the upper left side is arranged to be a scan electrode and the lower side is arranged to be a common electrode, the right side is arranged to be a common electrode, and the lower side is arranged to be a scan electrode.

In this case, the common electrode performs only a sustain function, and the scan electrode performs a sustain and a scan function.

And the sustain voltage input is applied to the sustain voltage waveforms of the same polarity alternately to the left and right as in the conventional driving method without the upper and lower division.

FIG. 7 is a representative drive waveform for doubling the scan rate using the electrode arrangement given in FIG.

When the C1 electrodes and the S2 electrodes are connected to the same sustain voltage source, and the C2 electrodes and the S1 electrodes are applied with another sustain waveform delayed by a half cycle from the waveform applied to the C1 / S2 electrodes, the C1 electrodes And phase difference between the C2 electrodes and the S1 electrodes and the S2 electrodes by 1/2 cycle.

At this time, the polarity of the sustain waveform is applied as the negative polarity as in the conventional driving method.

The data pulses are alternately inputted into data pulses 1 constituting the upper part of the screen and data pulses 2 constituting the lower part of the screen.

Each of these data pulses is synchronized with a corresponding scan pulse to control the flashing operation of the cell.

In this case, all data pulses are applied with positive polarity and all scan pulses are applied with negative polarity.

The erase pulse is applied to the scan electrodes (S1 and S2 electrodes) after a predetermined time elapses with a negative polarity as in the conventional method.

In the case of using the method shown in FIG. It is possible to scan one scan line on the upper screen and one scan line on the lower screen in one sustain period and sequentially scan the upper and lower screens one time at a time in one sustain period. The time required can be reduced to 1/2 compared to the conventional method.

In addition, since the waveforms of FIG. 7 have the same polarity as the waveforms used in the conventional method, there is no increase in the complexity of the circuit configuration required by using this waveform in the driving circuit configuration.

8 is a schematic diagram of an AC PDP electrode arrangement in which the phase difference method of data and scan pulses can be used in the present invention, wherein the electrodes of the upper group and the lower group of the screen are represented by {(S1, C1), (S2, C2). )}, (B) is {(S1, C1) (C2, S2)}, (c) is {(C1, S1) (S2, C2)}, (d) is {(C1, S1) (C2, S2)} shows a structural diagram arranged in the order of, as in this structure, the discharge time is increased in the three-electrode surface discharge AC PDP having various electrode arrangements, thereby improving the brightness and contrast of the entire screen.

As described above, the present invention can simultaneously drive the upper and lower portions of the screen within one sustain pulse period by using the phase difference of the driving pulses without physically separating the upper and lower portions, and it is necessary to scan the entire screen. By reducing the time to 1/2, the discharge time of the PDP cell can be increased, thereby improving the brightness and contrast of the entire screen, and also sustaining, scanning, and erasing the negative polarity used in the present method. The same result can be obtained by using pulses having opposite polarities instead of pulses and positive polarity data pulses.

Claims (7)

In a three-electrode surface discharge AC PDP in which each cell consists of two row electrodes and one column electrode, The row electrodes are divided into upper and lower groups of the screen, and the phase difference between the driving pulses applied to each group is separated by 1/2 of the sustain pulse to reduce the time required for full screen scanning by 1/2. AC plasma display device (AC PDP) driving method using a phase difference method. Data pulses are applied to the column electrodes, and the row electrodes are divided into common electrodes to which only the sustain pulses are applied and scan electrodes to which the sustain, scan and erase pulses are applied together. An AC plasma display device (AC PDP) driving circuit configured to reduce the time required for full screen scanning by half by a half cycle of the sustain pulse. The method of claim 2, The same sustain voltage source is connected to the C1 common electrodes and the S2 scan electrodes, and the C2 common electrodes and the S1 scan electrodes are connected to the sustain voltage source which is delayed by 1/2 of the waveform applied to the C1 common and S2 scan electrodes, and is scanned. A pulse is inserted between the sustain pulses of the S1 scan electrode and the S2 scan electrode, and the scan pulses between the two electrodes are separated by 1/2 period of the sustain pulse to simultaneously scan the upper and lower portions of the screen in one period of the sustain pulse. AC plasma display device (AC PDP) driving circuit. The method of claim 2, The data pulses are divided into data pulses 1 for constituting the upper part of the screen and data pulses 2 for constituting the lower part of the screen, and the time difference between each other is set by half a period of the sustain pulse, and they are alternately inputted in synchronization with the scan pulses. AC plasma display device (AC PDP) driving circuit configured to reduce the time required for screen scanning. The method of claim 2, An AC plasma display device (AC PDP) driving circuit configured to apply an erase pulse to the scan electrodes S1 and S2 after a predetermined time required for screen configuration after application of the scan pulse. In a three-electrode surface discharge AC PDP in which each cell consists of two row electrodes and one column electrode, The row electrodes are divided into upper and lower groups of the screen, and each group is disposed so that the upper part is the scan electrode S1 and the lower part is the common electrode C2, and the upper part is the common electrode C1. And a lower portion of the PDP panel disposed to be a scan electrode (S2). The method of claim 6, The electrodes of the upper group of the screen are arranged in the order of (S1, C1), and the lower electrodes are arranged in the order of (S2, C2), and {(S1, C1) (C2, S2)}, {(C1, S1), respectively. (S2, C2)} or a PDP panel having a structure arranged in the order of {(C1, S1) (C2, S2)}.