KR19990081215A - Driving Method of Plasma Display Panel - Google Patents

Abstract

The present invention relates to a method of driving a plasma display panel that can stabilize the operation of a cell and improve brightness by adjusting a driving pulse in a holding section.

The PDP driving method of the present invention is characterized by changing the voltage and pulse width of the sustain pulse supplied so that a sufficiently large wall charge is formed inside the cell at the beginning of the sustain period.

According to the present invention, the voltage and pulse width of the sustain pulse supplied to the sustain section of each subfield or the voltage and pulse width are varied so that sufficient wall charges are formed inside the cell at the beginning of the sustain section, thereby leading to the sustain pulse. The sustain discharge by the normal sustain pulses can be stably progressed to prevent malfunction of the cell and to improve the brightness of the screen.

Description

Method of Driving Plasma Display Panel

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display apparatus, and more particularly, to a method of driving a plasma display panel that can stabilize a cell operation and improve brightness by adjusting a driving pulse in a sustaining period of each subfield.

Recently, research into plasma display panels (hereinafter referred to as PDPs) with the possibility of accessing cathode ray tubes (CRTs) having high quality and low power consumption as flat panel display devices that pursue thinning, large size, and high image quality is actively conducted. It is becoming. This PDP is a display device that displays images by using a gas discharge phenomenon, and has the advantage of making a large area that other flat panel display devices, such as LCD (Lyquid Crystal Display) and EL (Electro Luminescence) display modules, cannot have. . In addition, PDPs have been widely spotlighted compared to other flat panel display devices in terms of low power consumption by using discharge selectivity due to nonlinearity, simplicity of process according to a simple structure, and low cost by using most glass materials.

Such PDPs are largely classified into AC and DC methods. AC type PDP is characterized by applying an alternating voltage between two electrodes with a dielectric interposed therebetween to discharge every half cycle, and DC type PDP is characterized in that it discharges by directly applying a DC voltage between electrodes. Here, the AC-type PDP is a surface discharge type using three electrodes and has a merit that low power driving is possible because a dielectric having a memory effect is used as charge accumulation. On the other hand, the direct current type PDP is a counter-discharge type, which applies a voltage directly between the electrodes, so that the luminous efficiency is good. However, the PDP of the direct current type PDP has a short lifespan by exposing the electrodes to the discharge space.

1 is a cross-sectional view showing a structure of a subcell included in a pixel cell of an alternating current (AC) type PDP. In general, a pixel cell of a PDP has three colors corresponding to red (R), green (G), and blue (B). It consists of three subcells.

In the sub-cell of the PDP shown in FIG. 1, the lower glass 20 is positioned to have a predetermined distance from the upper glass 10, which is the display surface of the image, and the upper glass 10 and the lower glass 20 are positioned. The partition 16 is formed in the cell to provide a discharge space in the cell. On the top glass 10, two sustain electrodes, that is, the scan / hold electrode Y and the sustain electrode Z, are arranged side by side, and on the top glass 10 on which the sustain electrodes 12a and 12b are disposed. The dielectric layer 12 is formed flat. A protective film 14, for example, a magnesium oxide (MgO) film, is formed on the dielectric layer 12 to prevent damage to the dielectric layer 12 from sputtering of plasma particles. The address electrode X is disposed on the lower plate glass 20, and the red, green, and blue colors for emitting red, green, and blue visible light when the cells are discharged are disposed on the lower plate glass 20 on which the address electrode X is disposed. Any one of the phosphors 16 is applied including a portion of the partition wall 18. An inert gas such as neon (Ne), helium (He), xenon (Xe), and the like is enclosed in the internal space of the PDP cell configured as described above. These gases are ionized into electrons and ions by a counter discharge between the scan / hold electrode Y and the address electrode X, that is, by a scan discharge, and become a plasma state. In this plasma state, the particles are exposed to ultraviolet rays generated by collisions. The phosphor is excited to emit light.

2 illustrates an electrode arrangement structure of a general PDP, in which the scan / sustain electrode lines Y and the sustain electrode lines Z are disposed so as to intersect in the horizontal direction of the PDP 30, and the scan / The address electrode lines X are disposed to be orthogonal to the storage electrode lines Y and the storage electrode lines Z, thereby forming a matrix structure.

The conventional AC PDP configured as described above may be driven by an ADS driving method or a non-ADS driving method. The ADS driving method is a method of dividing and driving one frame into a plurality of subfields according to the gradation to be implemented. Each subfield is driven by being divided into a reset section, an addressing section, and a sustain section.

Referring to FIG. 3, a method of giving a gradation for one frame by the ADS method is illustrated. This is an example of giving 256 gradations. For this purpose, one frame is composed of eight subfields included in an interval of 16.67 ms. In Fig. 2, the reset and addressing sections of each subfield are all assigned the same, and the holding section is 2 ⁰ , 2 ¹ , 2 ² ,.. , 2 ⁸ It will be allocated at the ratio of. In each subfield, the relative value of luminance is determined by the number of pulses applied for sustain discharge in the sustain period, and the gray level of the image is displayed by the combination of the determined luminance.

Referring to FIG. 4, a driving waveform of one subfield divided into a reset period, a scan period, and a sustain period is illustrated. 4A shows a voltage waveform supplied to the address electrode X, (b) a voltage waveform supplied to the scan / hold electrode Y, and (c) a supply to the sustain electrode Z. Shows the voltage waveform.

In FIG. 4, the reset section is a section for slightly retaining wall charges in the entire cell for stable operation of the cell. To this end, a high voltage is applied between the scan / sustain electrode Y and the sustain electrode Z to form wall charges in the dielectric layer 12. Once erased, most wall charges are neutralized. In this case, as shown in FIG. 4, a plurality of discharges are generated between the scan / sustain electrode Y and the sustain electrode Z in the reset section, thereby maintaining uniform wall charges inside the cell. The addressing section is a section for accumulating wall charges such that the next sustain discharge is possible for the pixels to be lit in accordance with the scan discharge. To this end, a scan discharge is performed by the image data pulse applied to the address electrode X and the scan pulse applied to the scan / sustain electrode Y to form wall charges in the cells to be lit.

In each subfield, the sustain section is a section for generating sustain discharge only for the cells in which the scan discharge is generated by raising the sustain pulse under the wall charge. To this end, a relative discharge value is determined by performing sustain discharge according to a sustain pulse applied between the scan / sustain electrode Y and the sustain electrode Z using wall charges formed inside the lit cell in the addressing section. Accordingly, the sustain discharge section is an important section so as to influence the performance of various matters such as brightness and efficiency of the screen and power consumption.

For example, in the case of VGA class, the sustain discharge proceeds after addressing 480 lines in the addressing section, and the sustaining pulses supplied to the wall charges formed in the addressing section are added and discharged to sustain the light emission. However, the wall charges formed in the cells to be lit in the addressing section are generally weak. As a result, the operation characteristics of the cell and the brightness of the screen depend on the wall charge and the sustain pulse in the sustain section.

Referring to FIG. 5, in one subfield illustrated in FIG. 4, a sustain pulse supplied to a sustain section is enlarged. FIG. 5A shows the voltage pulses supplied to the scan / sustain electrode Y and FIG. 5B shows the voltage pulses supplied to the sustain electrode Z. These sustain pulses have the same amplitude and pulse width.

However, as the wall charges formed in the addressing section are generally weak, it is insufficient to fully utilize the operation characteristics of the previous wall charges and the holding section with the same holding pulse and the same voltage supplied from the holding section. As such, since the sustain pulse according to the conventional PDP driving method does not fully utilize the wall charges in the addressing section, the operation of the cell is unstable or the brightness of the screen is lowered.

Accordingly, an object of the present invention is to provide a PDP driving method capable of stably operating a cell by adjusting a sustain pulse to fully utilize wall charges.

An object of the present invention is to provide a PDP driving method that can improve the brightness of the cell on the screen by adjusting the sustain pulse to fully utilize the wall charge.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view showing the structure of a PDP pixel cell of a conventional AC system.

2 is a diagram illustrating an electrode array structure of a PDP.

FIG. 3 is a diagram showing one frame composed of eight subfields for displaying 256 gradations. FIG.

4 is a view showing a waveform supplied to each electrode of FIG. 1 according to a conventional driving method.

5 is a waveform diagram supplied to a scan / sustain electrode and a sustain electrode in the sustain section of FIG. 4;

6 is a waveform diagram illustrating a PDP driving method according to the first embodiment of the present invention.

7 is a waveform diagram illustrating a PDP driving method according to a second embodiment of the present invention.

8 is a waveform diagram illustrating a PDP driving method according to a third embodiment of the present invention.

9 is a waveform diagram illustrating a PDP driving method according to a fourth embodiment of the present invention.

10 is a waveform diagram illustrating a PDP driving method according to a fifth embodiment of the present invention.

11 is a waveform diagram illustrating a PDP driving method according to a sixth embodiment of the present invention.

<Brief description of symbols for the main parts of the drawings>

10 top glass 12 dielectric layer

14: shield 16: partition

18 phosphor 20: bottom glass

X: address electrode Y: scan / hold electrode

Z: sustain electrode 30: PDP

In order to achieve the above object, the PDP driving method according to the present invention is to determine the reset period for remaining the wall charge in all cells by a predetermined amount, the address period for selecting the cells to be lit, the brightness of the lit cells A method of driving a plasma display panel in a frame unit including a plurality of subfields having a sustain period, the voltage and pulse width of a sustain pulse supplied so that a sufficiently large wall charge is formed inside the cell at the beginning of the sustain period. It characterized by changing the.

Other objects and advantages of the present invention in addition to the above object will become apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 6 to 11.

In general, the holding section of the reset section, the addressing section, and the holding section of one subfield determines the brightness, efficiency, power consumption, and the like of the PDP. In fact, a discharge occurs between the scan / hold electrode Y and the sustain electrode Z due to the wall charges formed in the addressing section (the discharge between the address electrode X and the scan / hold electrode Y is generated, and thus the dielectric layer 12 And the amount of ions formed before and on the voltage waveform supplied to the scan / hold electrode Y and the sustain electrode Z to be supplied to each other. Therefore, the PDP driving method according to the present invention adjusts the voltage and pulse width of the sustain pulse supplied from the sustain section in order to perform a stable sustain operation by fully utilizing the wall charges formed by the addressing discharge.

6 shows only the sustain voltage waveform supplied to the sustain section in the PDP driving method according to the first embodiment of the present invention. Fig. 6A shows the voltage waveform supplied to the scan / sustain electrode Y, and (b) shows the voltage waveform supplied to the sustain electrode Z. Figs.

In the PDP driving method according to the first exemplary embodiment of FIG. 6, a sustain voltage pulse having a higher voltage than usual is supplied at the beginning of the sustain period. These high voltage pulses provide sufficient wall charge in the sustain period after addressing discharge, allowing the cell to perform stable operation immediately. In other words, by supplying a voltage pulse higher than usual at the beginning of the sustain section, a larger amount of wall charges are formed in the scan / hold electrode Y and the sustain electrode Z, and then to the normal voltage pulse supplied next. As the wall charge is added, the sustain discharge operation proceeds, thereby allowing the cell to operate stably.

7 shows only the sustain voltage waveform supplied to the sustain section in the PDP driving method according to the second embodiment of the present invention. Fig. 7A shows the voltage waveform supplied to the scan / sustain electrode Y, and (b) shows the voltage waveform supplied to the sustain electrode Z. Figs.

In the PDP driving method according to the second embodiment of FIG. 7, a sustain pulse having an increased pulse width while having a normal voltage at the beginning of the sustain section is provided. At the beginning of the sustain section, a larger amount of wall charge is initially formed by supplying the sustain pulse with increased pulse width to the scan / sustain electrode Y and sustain electrode Z. FIG. Accordingly, the wall charge is added to the sustain pulse having the normal pulse width supplied next, and the sustain discharge operation proceeds continuously, thereby enabling the cell to operate stably.

8 shows only the sustain voltage waveform supplied to the sustain section in the PDP driving method according to the third embodiment of the present invention. FIG. 8A shows a voltage waveform supplied to the scan / sustain electrode Y, and (b) shows a voltage waveform supplied to the sustain electrode Z. In FIG.

In the PDP driving method according to the third exemplary embodiment of FIG. 8, a sustain pulse having a higher voltage and an increased pulse width than that at the beginning of the sustain section is supplied. At the beginning of the sustain section, a larger amount of wall charge is initially formed by supplying sustain pulses with increased voltage and pulse width to the scan / sustain electrodes Y and sustain electrodes Z. FIG. Accordingly, the wall charge is added to the sustain pulse having the normal pulse width supplied next, and the sustain discharge operation proceeds continuously, thereby enabling the cell to operate stably.

9 shows only the sustain voltage waveform supplied to the sustain section in the PDP driving method according to the fourth embodiment of the present invention. Fig. 9A shows the voltage waveform supplied to the scan / sustain electrode Y, and (b) shows the voltage waveform supplied to the sustain electrode Z. Figs.

The PDP driving method according to the fourth embodiment of FIG. 9 supplies a sustain pulse having a voltage higher than usual and an increased pulse width at the beginning of the sustain section to form sufficient wall charges initially, and then The width is to reduce. At the beginning of the sustain section, a larger amount of wall charge is initially formed by supplying sustain pulses with increased voltage and pulse width to the scan / sustain electrodes Y and sustain electrodes Z. FIG. Accordingly, the sustain discharge can be stably performed even if the width of the sustain pulse supplied next is shortened, thereby reducing the power consumption and improving the discharge efficiency.

10 shows only the sustain voltage waveform supplied to the sustain section in the PDP driving method according to the fifth embodiment of the present invention. 10A shows a voltage waveform supplied to the scan / sustain electrode Y, and (b) shows a voltage waveform supplied to the sustain electrode Z. In FIG.

The PDP driving method according to the fifth embodiment of FIG. 10 forms a sufficient wall charge at the beginning by supplying a sustain pulse having an increased pulse width while having a voltage as usual at the beginning of the sustain section. The width of the holding pulse is divided gradually by a certain unit. At the beginning of the sustain section, a larger amount of wall charge is initially formed by supplying the sustain pulse with increased pulse width to the scan / sustain electrode Y and sustain electrode Z. FIG. Accordingly, even when the width of the sustain pulse is supplied in a predetermined unit and gradually decreases, the sustain discharge can be stably performed, thereby reducing power consumption and improving discharge efficiency.

11 shows only the sustain voltage waveform supplied to the sustain section in the PDP driving method according to the sixth embodiment of the present invention. Fig. 11A shows the voltage waveform supplied to the scan / sustain electrode Y, and (b) shows the voltage waveform supplied to the sustain electrode Z. Figs.

The PDP driving method according to the sixth embodiment of FIG. 11 supplies a sustain pulse having a voltage higher than usual and an increased pulse width at the beginning of the sustain section to form sufficient wall charges initially, and then Voltage and pulse width are divided gradually by a certain unit. At the beginning of the sustain section, a larger amount of wall charge is initially formed by supplying sustain pulses with increased voltage and pulse width to the scan / sustain electrodes Y and sustain electrodes Z. FIG. Accordingly, even if the voltage and pulse width of the next sustaining pulse are divided by a predetermined unit and gradually reduced, the sustaining discharge can be stably performed, thereby reducing the power consumption and improving the discharge efficiency.

These various PDP driving methods increase the voltage, pulse width or voltage and pulse width of the sustain pulse supplied at the beginning of the sustain period to form sufficient wall charges, thereby stabilizing the sustain discharge of the cell and preventing malfunction. Instead, the brightness of the cell can be improved. In addition, by forming sufficient wall charges by the initial sustain pulses, stable sustain discharge can proceed even if the voltage, pulse width or voltage and pulse width of the sustain pulses supplied next decrease. This has the effect of driving the PDP at low power.

As described above, according to the PDP driving method according to the present invention, there is sufficient wall inside the cell at the beginning of the sustain period by changing the voltage, pulse width or voltage and pulse width of the sustain pulse supplied to the sustain section of each subfield. An electric charge will be formed. As a result, the sustain discharge by the normal sustain pulses following the initial sustain pulse can be stably progressed, thereby preventing the malfunction of the cell and improving the brightness of the screen. Further, even if the voltage or pulse width of the sustain pulses following the initial sustain pulse or the voltage and pulse width are reduced, the sustain discharge can be stably progressed by sufficient wall charge. Accordingly, there is an advantage that can drive the PDP at a lower power.

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 (11)

Frame unit including a plurality of subfields including a reset section for retaining wall charges in all cells by a predetermined amount, an address section for selecting a cell to be lit, and a holding section for determining the brightness of the lit cells In the method for driving a plasma display panel, And a voltage and a pulse width of the sustain pulse supplied so as to form a sufficiently large wall charge inside the cell at the beginning of the sustain section. The method of claim 1, And a pulse width and a voltage of a sustain pulse supplied at an initial stage of the sustain section. The method of claim 2, And a voltage and pulse width of the sustain pulses continuously supplied to the initial sustain pulse are gradually reduced. The method of claim 3, wherein And dividing the voltage and pulse width of the sustain pulses into predetermined units to gradually reduce the voltage. The method of claim 2, And gradually reducing any one of a voltage and a pulse width of sustain pulses continuously supplied to the initial sustain pulse. The method of claim 5, And dividing one of a voltage and a pulse width of the sustain pulses continuously supplied to the initial sustain pulse into predetermined units to gradually reduce the plasma display panel. The method of claim 1, And increasing one of a voltage and a pulse width of a sustain pulse supplied at an initial stage of the sustain section. The method of claim 7, wherein And a voltage and pulse width of the sustain pulses continuously supplied to the initial sustain pulse are gradually reduced. The method of claim 8, And dividing the voltage and pulse width of the sustain pulses into predetermined units to gradually reduce the voltage. The method of claim 7, wherein And gradually reducing any one of a voltage and a pulse width of sustain pulses continuously supplied to the initial sustain pulse. The method of claim 10, And dividing one of a voltage and a pulse width of the sustain pulses continuously supplied to the initial sustain pulse into predetermined units to gradually reduce the plasma display panel.