KR20000021115A - Method for driving plasma display panel - Google Patents

Abstract

The present invention relates to a method of driving a plasma display panel, comprising: a plurality of address electrodes formed on one substrate, a plurality of sustain electrodes formed on the other substrate facing the substrate so as to be orthogonal to the address electrodes, and the address electrodes and the sustain electrodes An AC-type plasma display panel structure including discharge cells formed at intersections of the reset cells and alternately applying pulses alternately to uniform wall charges of the discharge cells; An address step of specifying a pixel by data pulses applied to the plurality of address electrodes whenever scan pulses are applied to the plurality of sustain electrodes and the scan pulses are applied; A driving method comprising a sustain discharge step of applying an alternating pulse to maintain a discharge to implement an image, wherein the pulses applied alternately in the sustain discharge step have different widths. It is characterized in that the made, including, the image quality of the color plasma display panel is improved, the life is extended, the power consumption is reduced.

Description

Driving Method of Plasma Display Panel

The present invention relates to a plasma display panel (hereinafter referred to as a plasma display panel), and more particularly to a method for driving a PD.

PD and LCD are spotlighted as next generation display devices with the highest design among flat panel displays. In particular, PDP has higher luminance and wider viewing angle than LCD, and thus has wide applicability as a thin, large display such as an outdoor advertising tower, a wall-mounted TV, or a theater display.

The PD is used to display and emit light using gas discharge. In the configuration, the PD is classified into an AC PD with a dielectric layer formed on the surface of the electrode and a DC PD with the surface of the electrode exposed to the discharge space. In the AC type PD, the phosphor is formed on the dielectric layer, and in the DC type PD, the phosphor is formed on the electrode. PDPD emits the phosphor by irradiating the phosphor with ultraviolet rays generated by gas discharge.

The structure of a typical AC type counter discharge PDPD is composed of a plurality of matrix electrodes as shown in FIG. The opposite discharge type PDP includes a sustain electrode 11 formed on the front substrate 10, a dielectric layer 12 formed thereon, and a protective layer made of magnesium oxide (MgO) or the like to protect the surface of the dielectric layer with ion shock ( 13), the address electrode 21 formed on the back substrate 20, the dielectric layer 22 formed thereon, the partition 23 formed on the dielectric layer, and the phosphor 24 coated between the partition walls.

The pulse applied to each electrode for driving the general PD shown in FIG. 1 is the same as that shown in FIG. 2. The driving pulse of a typical PD is divided into a reset discharge period, an address discharge period, and a sustain discharge period in order to select a discharge cell of the PD PD and to sustain light emission.

In the reset discharge period, the address electrodes and the sustain electrodes are discharged to erase wall charges in the discharge cells to initialize the cells.

In the address discharge period, a scan pulse 30 is applied to the sustain electrode, a data pulse 40 is applied to the address electrode, and a cell to be discharged is selected to form wall charges in the cell. FIG. 2 is a waveform diagram illustrating that a positive voltage data pulse 40 is applied to an address electrode and a negative voltage scan pulse 30 is applied to a sustain electrode. As a result, electrostatic charges are generated at the address electrodes and negative charges are generated at the sustain electrodes. At this time, both the generated static charge and the negative charge are wall charges.

In the sustain discharge period, sustain pulses 31 and 41 which are out of phase with each other are continuously applied to all of the address electrodes and all the sustain electrodes that are opposed to each other. At this time, the discharge cells in which the wall charges are generated in the above-described address discharge period are kept at a predetermined wall voltage, so that the wall voltage Vw and the discharge sustain voltage Vs due to the sustain pulse are overlapped. A potential difference equal to or greater than the discharge threshold voltage Vb is generated in the discharge cell. As a result, even when sustain pulses are simultaneously applied to all address electrodes and all sustain electrodes, the discharge is not maintained in all the discharge cells, but only in the discharge cells in which wall charges are generated during the address discharge period. Using this principle, each cell of the screen selectively emits light in an AC PD.

In addition to the AC type PD, there is a DC type PD formed by exposing an electrode in a discharge space. As shown in FIG. 3, the structure of the DC PD panel includes a plurality of matrix electrodes, a plurality of cathodes 50, a plurality of display anodes 60 orthogonal to the cathodes, and a plurality of auxiliary cathodes 70. It consists of.

The cathode 50 and the anodes 60 and 70 are divided by the partition wall 23, and the space of the display discharge cell 80 and the space of the auxiliary discharge cell 80 ′ are respectively configured. Most barrier ribs 23 and the glass substrates 10 and 20 are composed of a space of a predetermined distance to form a priming path. The priming path flows the auxiliary discharge generated in the auxiliary discharge cell 80 'into the display discharge cell 80.

The DC type PD of this structure uses a pulse memory system, and a method for driving the pulse memory system is as shown in FIG. The sustain discharge pulse 90 of Fig. 5 is always applied to the cathode, and the scanning pulse 95 is applied in turn from the first cathode.

The secondary discharge always occurs whenever the scan pulse 95 'is applied to the secondary discharge cell 80'. Then, the discharge of the auxiliary discharge cell 80 'continuously moves to adjacent adjacent discharge cells. At this time, the discharge moved to the adjacent secondary discharge cell 80 'generates charged particles, and the charged particles diffuse through the priming path to the adjacent display discharge cell 80 to delay the ignition of the display discharge cell. Decrease.

While the scan pulse 95 is applied to the cathode 50, the data pulse 93 applied to the display anode 60 is assisted by an auxiliary discharge, that is, a priming path, to cause a display discharge. Therefore, since the discharge voltage of the display discharge cell 80 is lowered, the once addressed cell continues to be discharged only by applying the sustain discharge pulse 90.

However, in the conventional AC type opposite discharge PD, the sustain discharge waveforms applied to the positive electrodes during the sustain discharge period have opposite phases, so that the positive electrodes are impacted by ions while the discharge is sustained. Due to such a shock, the conventional AC type opposite discharge PD has a problem that the electrode and the dielectric layer are damaged, and the life of the product is shortened due to deterioration of the phosphor.

In addition, the conventional DC-type PDPD has a problem in that the area ratio of the display discharge cell is reduced due to the auxiliary discharge cell, the luminance of the PD is reduced, and the number of pixels is reduced, making it difficult to realize high resolution. In addition, since the electrode is exposed to the discharge space and ions collide directly with the electrode and the phosphor, there is a problem in that the lifetime is shortened.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object thereof is to provide a PDP driving method for improving the image quality of a PD and extending the life of the PD.

1 is a view showing a schematic structure of a typical AC plasma display panel.

2 illustrates waveforms of pulses applied to the electrodes of the plasma display panel of FIG.

3 shows a schematic structure of a DC plasma display panel;

4 illustrates waveforms of pulses applied to the electrodes of the DC plasma display panel shown in FIG. 3;

FIG. 5 illustrates a structure of a plasma display panel in which the present invention is implemented, in which two glass substrates are bonded to each other and electrodes are formed to face each other.

FIG. 6 is a diagram showing a driving method of the present invention, showing waveforms of pulses applied to respective electrodes of a plasma display panel; FIG.

FIG. 7 is a diagram showing a potential difference held in each discharge cell of the plasma display panel by the pulse shown in FIG.

8A to 8D are diagrams showing the state of the discharge cell operated by FIG.

Explanation of symbols for main parts of the drawings

100: top plate 110: sustain electrode

200: lower plate 210: address electrode

300: first voltage pulse 310: second voltage pulse

320: scan pulse 330: data pulse

340: third voltage pulse 350: fourth voltage pulse

400: negative wall charge 410: positive wall charge

430: space charge 440: metastable garden

In the PDP driving method of the present invention, an impact point of ions generated by the discharge between the address electrode and the sustain electrode is different from the time point at which the voltage applied to the address electrode and the voltage applied to the sustain electrode are applied during the discharge period of one subfield. It is characterized by minimizing.

The PDP in which the driving method of the present invention is implemented has a structure in which the lower plate 200 and the upper plate 100 are bonded as shown in FIG. 5. The address electrode 210 is continuously formed in the lower plate 200, and the sustain electrode 110 is formed continuously in the direction perpendicular to the address electrode of the lower plate in the upper plate 100. Discharge cells 220 are divided into partitions at the intersections of the address electrodes and the sustain electrodes, and inert gases such as neon (Ne), argon (Ar), and xenon (Xe) are mixed in the discharge cells. It is sealed. Since the structure of the PDP to which the driving method of the present invention is implemented is the same as that of the conventional PDP, a detailed description of the structure of the PDIP will be omitted.

The most preferred embodiment of the method of driving the plasma display panel of the present invention is to make the turn-on period of the third pulse applied to the address electrode shorter than the turn-on period of the fourth pulse applied to the sustain electrode in order to maintain the discharge of the discharge cells. . That is, according to the present invention, the pulse width of the third pulse applied to the address electrode is smaller than the pulse width of the fourth pulse applied to the sustain electrode.

Further, according to the present invention, the time point at which the third voltage pulse applied to the address electrode is turned on is earlier than the time point at which the fourth voltage pulse applied to the sustain electrode is turned on. At this time, the turn-on period of the third voltage pulse is within 1.5 microseconds, and the time difference between the time when the third voltage pulse is turned off and the time when the fourth voltage pulse is turned off is about 2 micro seconds. Therefore, the present invention shows the sustain discharge pulse as shown in FIG. 7 during the sustain discharge period of the PD.

Hereinafter, a method of driving PDIP according to the present invention will be described in detail with reference to a preferred embodiment of the present invention.

(Example)

An embodiment of the present invention provides a method of applying a first voltage pulse to an address electrode and applying a second voltage pulse to the sustain electrode during a period in which the first voltage pulse is kept high, and a scan pulse to a portion of the sustain electrode. And applying a data pulse to the address electrode each time a scan pulse is applied, and applying a third voltage pulse having a lower potential than the first voltage pulse to the address electrode and keeping the third voltage pulse high. And applying a fourth voltage pulse to the sustain electrode during the period of time.

Hereinafter, a PDP driving method of an embodiment of the present invention will be described with reference to FIGS. 6 and 7. In the PDD driving method according to the embodiment of the present invention, as shown in FIG. 6, one subfield is divided into a reset discharge period, an address discharge period, and a sustain discharge period, and a width of a pulse applied to the sustain electrode during the sustain discharge period. And widths of pulses applied to the address electrodes are varied. That is, the present invention is characterized in that the widths of the pulses applied to each other alternately during the sustain discharge period of the PD.

First, in the reset discharge period, the PDP driving circuit according to the embodiment of the present invention simultaneously applies a predetermined first voltage pulse 300 to all the address electrodes of the PD, and during the ON period of the first voltage pulse, The second voltage pulse 310 having a larger pulse width than the first voltage pulse is applied to all the sustain electrodes. At this time, the rising time of the first voltage pulse and the rising time of the second voltage pulse have a slight time difference as shown in FIG. That is, the second voltage pulse rises during the high section of the first voltage pulse, and the first voltage pulse falls during the high section of the second voltage pulse. As a result, discharge is generated in all the discharge cells of the PD, and wall charges are formed on the surface of each electrode. At this time, wall charges of all the discharge cells are uniformly formed.

In the PD discharge driving circuit according to the embodiment of the present invention, the scan pulse 320 is sequentially applied to the sustain electrodes of the PD electrodes in which the wall charges are to be erased, and the scan pulses are applied to the sustain electrodes. The data pulse 330 of a phase opposite to that of the scan pulse phase is applied to all cells except for cells to emit light of the PD. As a result, the wall charges formed in the discharge cells formed at the intersections of the sustain electrodes to which the scan pulses are applied and the address electrodes to which the data pulses are applied are erased. At this time, the discharge cells are selectively discharged by data pulses and scan pulses having a selectively high value. Therefore, the light emission of the pixel of the PDP is selected by this selective discharge operation.

Then, in the sustain discharge period, the PDP drive circuit according to the embodiment of the present invention applies the third voltage pulse 340 to all the address electrodes of the PDP at the same time, and during the on period of the third voltage pulse, The fourth voltage pulse 350 having a larger pulse width than the third voltage pulse is simultaneously applied to the sustain electrode. At this time, as in the reset discharge period, the rise time of the third voltage pulse and the rise time of the fourth voltage pulse have a slight time difference as shown in FIG. That is, the fourth voltage pulse rises during the high section of the third voltage pulse, and the third voltage pulse falls during the high section of the fourth voltage pulse. As a result, the discharge of the pixel specified in the address discharge period is maintained continuously.

At this time, the potential Vs of the third voltage pulse 340 is generally lower than the potential Vr of the first voltage pulse 300. This is because no wall charge is formed inside the discharge cell at the time when the first voltage pulse is applied. Since the wall charges by the first voltage pulse are formed inside the discharge cell at the time when the third voltage pulse is applied, the voltage required for discharge is lower than the time when the first voltage pulse is applied.

The improvement of the PDP driving method according to the embodiment of the present invention over the conventional PDP driving method can lower the potential of the pulse applied to the sustain electrode during the sustain discharge period, and the ion shock applied to the electrode, the dielectric, and the phosphor during the discharge process. This is the point that is reduced. Hereinafter, the reason and the operation principle and operation of the embodiment of the present invention will be described with reference to FIGS. 7 and 8.

First, the cell that emits light in the PD is formed with wall charges through the reset discharge period and the address discharge period, thereby bringing a state as shown in FIG. 8A. That is, wall charges 400 and 410 having opposite polarities are accumulated in the address electrode 210 and the sustain electrode 110. Therefore, the wall voltage Vw due to wall charge is maintained in the discharge region between the address electrode 210 and the sustain electrode 110.

Thereafter, when the third voltage pulse 340, that is, the sustain voltage Vs is applied to the address electrode 210 during the period between t1 and t2 of FIG. 7, the sustain voltage and the wall voltage are overlapped and applied to the discharge region. As a result, primary discharge is generated in the discharge region as shown in FIG. 8B by the overlapping voltage of the sustain voltage and the wall voltage, and a large number of space charges and metastable atoms are generated in the discharge region where the primary discharge is performed. .

In addition, when a fourth voltage pulse 350 is applied to adjust the voltage so that the address voltage and the discharge are not generated in the sustain electrode in the interval between t2 and t3 of FIG. 7, between the address electrode 210 and the sustain electrode 110. Since the potential difference does not occur, the metastable atoms 440 and the space charges 430 are continuously maintained as shown in FIG. 8C. Therefore, the discharge cell maintains an electrically conducting state in the interval between t2 and t3.

In the section between t3 and t4 of FIG. 7, the fourth voltage pulse 350 is continuously applied to the sustain electrode to generate a secondary discharge at t3. This section has the effect that the discharge occurs at a voltage much lower than the discharge generated in the section between t1 and t2 by the space charge and metastable atoms generated by the discharge generated in the section between t1 and t2. That is, the potential difference applied to the both ends of the electrode during the secondary discharge is much lower than the potential difference applied to the both ends of the electrode during the primary discharge. This effect is the priming effect.

As shown in FIG. 8B, the priming effect is achieved by driving the external driving circuit to generate the secondary discharge by maintaining the predetermined potential difference between the plurality of metastable atoms 440 and the space charges 430 generated after the primary discharge by the wall charge. This is the effect of lowering the discharge holding voltage applied in the furnace. That is, if the potential difference held by the metastable atoms and the space charges is Vp, and the voltage to be maintained between the address electrode and the sustain electrode to cause the secondary discharge is Vb, the external drive circuit must be at least Vb to generate the primary discharge. A discharge start voltage Vs having a potential was to be applied, but a discharge holding voltage having a potential higher than or equal to Vb-Vp may be applied to cause secondary discharge. Therefore, the discharge holding voltage applied by the external drive circuit to generate the secondary discharge is lower than the discharge start voltage applied by the external drive circuit to cause the primary discharge.

Thereafter, as shown in FIG. 8D, wall charges 400 and 410 having opposite polarities are again generated on the surface of the address electrode 210 and the sustain electrode 110 in the discharge cell, and the wall charges are discharged again. Maintain wall voltage at In the interval after t5, the phenomenon of the interval between t1 and t4 is repeated. As a result, the PDP driving method of the embodiment of the present invention can reduce the ion impact of each electrode and prevent the degradation of the phosphor, so that the PDIP life is extended than before.

At this time, the width of the pulse applied to each electrode varies depending on the area of the electrode, the structure of the barrier rib, the characteristics of the discharge gas, etc., but the time between the t1 and t2 sections does not eliminate plasma and metastable atoms. The pulse widths of the address electrode and the sustain electrode are adjusted to be set to a time within the range. Then, the time period between the period t3 and t4 is adjusted to the time of the range in which the wall charge can be formed stably to adjust the pulse width of the address electrode and the sustain electrode. In general, the time between the t1 and t2 sections is usually within 1.5 microseconds, and the time between the t3 and t4 sections is usually 2 microseconds or more.

When the discharge voltage is lowered, the ion impact on the electrode, the dielectric, and the phosphor is reduced, and the lifetime of the PD is extended. The reason for this is as follows.

First, the moving speed of the ions moving by the applied voltage between the data electrode and the sustain electrode in the discharge space is expressed by the following equation (1).

At this time, the moving distance of the ions is shown in Equation (2).

In addition, the following equation (3) holds.

Therefore, the kinetic energy of the ions moved by the distance s is as shown in equation (4).

At this time, Equation 4 is represented by Equation 5 again.

Equation 5 is expressed by Equation 6 based on the speed.

As expressed in Equation 6, the velocity of the ions is proportional to the voltage applied from the outside. At this time, the amount of impact the electrode and the phosphor receive by the kinetic energy of ions is expressed by Equation (7).

FΔt = mV

As shown in Equation 6, the speed at which ions move is proportional to the voltage applied from the outside, and as shown in Equation 7, the amount of impact received by the electrode and the phosphor is proportional to the speed of the ions.

As a result, the present invention can cause secondary discharge at low voltage by the priming effect. The discharge by the low voltage reduces the impact of ions applied to the electrode, the dielectric layer and the phosphor, and thus has an effect of extending the life of the PD.

In the PDP driving method according to the embodiment of the present invention, pulses applied to the address electrode and the sustain electrode during the sustain discharge period may be applied in the same manner during the reset discharge period.

In addition, the effect of applying pulses having different widths in the sustain discharge step of the present invention can be applied not only to the PD of the opposite discharge type but also to the sustain discharge period of other types of AC PDs. Therefore, the sustain discharge step of the present invention can solve the problem of deterioration of the electrode, the phosphor, and the dielectric layer, which is a problem in various types of PD.

Compared to the conventional PDP driving method, the PDP driving method of the present invention reduces the ion impact applied to the electrode, prevents deterioration of the phosphor, and improves the image quality of the color PD, and has an effect of extending the life of the PD. In addition, power consumption is reduced by applying a lower sustain discharge pulse than the conventional PD drive method.

Claims (7)

An AC plasma including a plurality of address electrodes formed on one substrate, a plurality of sustain electrodes formed on the other substrate facing the substrate so as to be orthogonal to the address electrodes, and discharge cells formed at intersections of the address electrodes and the sustain electrodes; A reset step of applying a pulse to the display panel structure alternately to make the wall charges of the discharge cells uniform; An address step of specifying a pixel by data pulses applied to the plurality of address electrodes whenever scan pulses are applied to the plurality of sustain electrodes and the scan pulses are applied; In the driving method comprising a sustain discharge step of implementing an image by applying a pulse alternately to maintain a discharge, And the pulses applied alternately in the sustain discharge step have different widths. The method of claim 1, further comprising: maintaining one of the pulses that are alternately applied in the sustain discharge step, and the other pulse is turned on after a predetermined time to maintain the discharge. A method of driving a plasma display panel. The method of claim 2, wherein the one pulse width is less than or equal to the other pulse width. The method of claim 1, further comprising the steps of: one of the pulses applied alternately in the reset step is turned on, and after a predetermined time, the other pulse is turned on to maintain the discharge; A method of driving a plasma display panel. The method of claim 4, wherein the one pulse width is less than or equal to the other pulse width. 5. A method for driving a plasma display panel according to any one of claims 2, 3 and 4, wherein the predetermined time is within 1.5 microseconds. 5. The plasma display according to any one of claims 2, 3, and 4, wherein a time difference between the time at which the one pulse falls and the time at which the other pulse falls is at least 2 microseconds. How to drive the panel.