KR100801702B1 - Method for driving plasma display panel - Google Patents

Abstract

The present invention relates to a method of driving a plasma display panel. The driving method includes a sustain pulse having alternating positive first voltages and negative second voltages in the sustain period, when the second voltage is applied to the scan electrodes. A positive voltage is applied to the sustain electrode.

According to the present invention, when the plasma display panel is driven by being divided into a reset section, an address section, and a sustain section, the positive and negative voltages are alternately applied to the scan electrodes in the sustain section, and the scan electrodes are alternately applied to the scan electrodes. By applying a positive voltage to the sustain electrode when applying a negative voltage, it is possible to increase the surface discharge between the scan electrode and the sustain electrode in the sustain period, and to suppress the occurrence of the counter discharge between the scan electrode and the address electrode, thereby displaying the display image. It is possible to increase the luminance and to secure a high margin in driving the plasma display panel.

Description

Method for driving plasma display panel {Method for driving plasma display panel}

1 is a perspective view illustrating a discharge cell structure of a general plasma display panel.

2 is a timing diagram showing a general waveform of signals for driving a plasma display panel.

3 is a timing diagram illustrating a method of time division driving by dividing one frame into a plurality of subfields.

FIG. 4 is a timing diagram illustrating a single sustain driving method in which a positive voltage and a negative voltage are alternately applied to a scan electrode and driven.

5 is a timing diagram illustrating an embodiment of a method of driving a plasma display panel according to the present invention.

The present invention relates to a plasma display device, and more particularly, to a method of driving a plasma display panel.

In the plasma display panel, a discharge cell is formed between a rear substrate having a partition wall and an opposite front substrate, and vacuum ultraviolet light generated when an inert gas inside each discharge cell is discharged by a high frequency voltage emits phosphors. Device.

1 is a perspective view illustrating a discharge cell structure of a general plasma display panel, in which an upper substrate 10 is opposed to a lower substrate 18, and the upper substrate 10 has a scan electrode Y and a sustain electrode Z. ) Is formed, and the address electrode X is formed on the lower substrate 18. The scan electrode Y and the sustain electrode Z are composed of transparent electrodes 12Y and 12Z and metal bus electrodes 13Y and 13Z having a line width smaller than that of the transparent electrode, respectively.

The transparent electrodes 12Y and 12Z include indium tin oxide (ITO), and the metal bus electrodes 13Y and 13Z include a metal such as chromium (Cr), It serves to reduce the voltage drop caused by the transparent electrodes 12Y and 12Z having high resistance. In addition, an upper dielectric layer 14 and a protective layer 16 are stacked on the upper substrate 10 to cover the scan electrode Y and the sustain electrode Z. Wall charges generated during plasma discharge are accumulated in the upper dielectric layer 14, and the protective layer 16 prevents damage to the upper dielectric layer 14 due to sputtering generated during plasma discharge and discharge efficiency of secondary electrons. Increase

In addition, a lower dielectric layer 22 is formed on the lower substrate 18, and a barrier rib 24 is formed to prevent leakage of ultraviolet rays and visible light generated by discharge into adjacent discharge cells, and the lower dielectric layer 22 is formed. And a phosphor layer 26 is applied to the surface of the partition wall 24. 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.

The plasma display panel is time-divisionally driven by dividing one frame into several subfields having different number of emission times in order to realize gray level of an image.

FIG. 2 is a timing diagram illustrating a general waveform of signals for driving a plasma display panel for the divided subfield.

The reset section is composed of a setup section and a setdown section, in which the rising ramp waveform Ramp-up is simultaneously applied to all of the scan electrodes Y, thereby finely discharging all the discharge cells. Is generated and thus wall charges are generated. In the set-down period, a falling ramp waveform (Ramp-down) falling at a positive voltage lower than the peak voltage of the rising ramp waveform (Ramp-up) is simultaneously applied to all the scan electrodes (Y), thereby erasing discharge in all discharge cells. Generated, thereby eliminating unnecessary charges during wall charges and space charges generated by the setup discharges.

In the address section, a negative scan pulse scan is sequentially applied to the scan electrode Y, and at the same time, a positive data pulse data is applied to the address electrode X. The address discharge is generated by the voltage difference between the scan pulse and the data pulse and the wall voltage generated during the reset period, and the cell is selected. On the other hand, a signal maintaining the sustain voltage Vs is applied to the sustain electrode Z during the set down period and the address period.

In the sustain period, a sustain pulse is alternately applied to the scan electrode (Y) and the sustain electrode (Z) to generate sustain discharge in the form of surface discharge between the scan electrode (Y) and the sustain electrode (Z). After the sustain discharge is completed, a ramp waveform erase for erasing wall charge is supplied to the sustain electrode Z.

According to the present invention, in driving a plasma display panel, a plasma display panel which prevents opposite discharge between the scan electrode and the address electrode in the sustain period and increases the surface discharge between the scan electrode and the sustain electrode to increase the brightness of the display image. An object of the present invention is to provide a driving method.

In the method of driving a plasma display panel according to the present invention for solving the above technical problem, a sustain pulse having an alternating first positive voltage and a second negative voltage is applied to a scan electrode in a sustain period. The positive voltage is applied to the sustain electrode while the second voltage is applied to the sustain electrode.

Preferably, a ground voltage is applied to the sustain electrode in the reset period and the address period, and the second voltage preferably has an absolute value lower than the first voltage.

When the second voltage is applied to the scan electrode, the second voltage is preferably set such that the voltage between the scan electrode and the address electrode is lower than the discharge start voltage. The discharge start voltage is a minimum voltage that must be applied for a discharge to occur in the discharge cell.

Preferably, a ground voltage is applied to the address electrode in the sustain period.

Hereinafter, a driving method of a plasma display panel according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a timing diagram illustrating a method of time-division driving by dividing a frame into a plurality of subfields. In order to realize time-division gray scale display, a unit frame includes a predetermined number of subfields SF1,. , SF8). Each subfield SF1, ... SF8 is divided into a reset section (not shown), an address section A1, ..., A8 and a sustain section S1, ..., S8.

In each address section A1, ..., A8, a display data signal is applied to the address electrode X, and scan pulses corresponding to each scan electrode Y are sequentially applied.

In each of the sustain periods S1, ..., S8, a sustain pulse is alternately applied to the scan electrode Y and the sustain electrode Z to form wall charges in the address periods A1, ..., A8. Sustain discharge occurs in the discharge cells.

The luminance of the plasma display panel is proportional to the number of sustain discharge pulses in the sustain discharge periods S1, ..., S8 occupied in the unit frame. When one frame forming one image is represented by eight subfields and 256 gradations, each subfield in turn has different sustains at a ratio of 1, 2, 4, 8, 16, 32, 64, and 128. The number of pulses can be assigned. In order to obtain luminance of 133 gradations, cells may be sustained by addressing the cells during the subfield 1 section, the subfield 3 section, and the subfield 8 section.

The number of sustain discharges allocated to each subfield may be variably determined according to weights of the subfields according to the APC (Automatic Power Control) step. The number of sustain discharges allocated to each subfield can be variously modified in consideration of gamma characteristics and panel characteristics. For example, the gray level assigned to subfield 4 may be lowered from 8 to 6, and the gray level assigned to subfield 6 may be increased from 32 to 34. In addition, the number of subfields forming one frame can be variously modified according to design specifications.

FIG. 4 is a timing diagram illustrating a single sustain driving method in which a positive voltage and a negative voltage are alternately applied to a scan electrode to be driven. As described above, one subfield SF includes a reset period, an address period, and a sustain period.

As shown in FIG. 4, in the reset period, the ground voltage Vg is first applied to each of the scan electrodes Y1,..., And Yn, and the sustain voltage Vs is suddenly applied, and then suddenly not. A rising ramp signal with no slope is applied up to the highest rising voltage. A weak discharge occurs due to the application of the rising ramp signal as described above, and negative charges begin to accumulate in the vicinity of the scan electrode while the weak discharge occurs. After a pulse rapidly falling to the ground voltage Vg is applied to the scan electrodes Y1,..., And Yn, a falling ramp signal is applied to reach the lowest falling voltage.

As the falling ramp signal is applied, a discharge occurs, and a portion of the negative charges accumulated near the scan electrode is emitted while the discharge occurs. As a result, a negative amount of negative charge remaining near the scan electrode is sufficient to generate an address discharge. The ground voltage Vg is applied to the sustain electrode Z and the address electrode X.

The ground voltage Vg is applied to the sustain electrode Z not only in the reset section but also in the entire address section and the sustain section, thereby reducing the manufacturing cost of the driving circuit by eliminating the circuit applying the pulse to the sustain electrode Z. have.

In the address period, a scan bias voltage is first applied to the scan electrodes Y1,..., And Yn to select a cell to be turned on, and then a scan pulse having a negative scan voltage is sequentially applied to each scan electrode. A display data signal having an address voltage Va on the address electrode X is applied in accordance with the scan pulse. The ground voltage Vg is subsequently applied to the sustain electrode Z. The address discharge is performed by the address voltage Va, the scan voltage, the wall voltage by the negative charge formed near the scan electrode Y and the wall voltage by the positive charge formed near the address electrode X. After the address discharge is performed, positive charges are accumulated in the vicinity of the scan electrode Y, and negative charges are accumulated in the vicinity of the sustain electrode Z.

In the sustain period, a sustain pulse having a positive sustain voltage Vs and a negative sustain voltage (-Vs) is alternately applied to the scan electrodes Y1, ..., Yn, and the sustain electrodes Z are alternately applied. Ground voltage Vg is applied.

As shown in FIG. 4, in the sustain period, the ground voltage Vg, which is an intermediate voltage, is applied to the scan electrode Y between the positive sustain voltage Vs and the negative sustain voltage V−s. It is preferable. By further applying the intermediate voltage, a sudden voltage change between the positive sustain voltage Vs and the negative sustain voltage (-Vs) is prevented.

When the positive sustain voltage Vs is applied to the scan electrode Y, the positive sustain voltage Vs applied to the sustain electrode Y, the ground voltage Vg applied to the sustain electrode Z, and the scan electrode While the sustain discharge is performed due to the wall voltage due to the positive charge accumulated near (Y) and the wall voltage due to the negative charge accumulated near the sustain electrode (Z), the negative charge accumulates near the scan electrode (Y) and the sustain electrode (Z). Positive charges build up nearby.

When the negative sustain voltage (-Vs) is applied to the scan electrode Y, the negative sustain voltage (-Vs) applied to the scan electrode Y and the ground voltage Vg applied to the sustain electrode Z are applied. ), While the sustain discharge is performed due to the wall voltage due to the negative charge accumulated near the scan electrode (Y) and the wall voltage due to the positive charge accumulated on the sustain electrode (Z), positive charges accumulate near the scan electrode (Y) and the sustain electrode (Z). Negative charges accumulate nearby.

As described above, since the positive sustain voltage Vs and the negative sustain voltage (-Vs) are repeatedly applied to the scan electrode Y alternately, the sustain discharge is generated a predetermined number of times.

5 is a timing diagram illustrating an embodiment of a method of driving a plasma display panel according to the present invention. In order to increase the brightness of the display image, preventing the discharge between the scan electrode (Y) and the address electrode (X) in the sustain period, and increasing the surface discharge between the scan electrode (Y) and the sustain electrode (Z) It is desirable. As shown in FIG. 5, it is preferable to apply the positive voltage Vz to the sustain electrode Z while the negative sustain pulse is applied to the scan electrode Y in the sustain period. By applying the positive voltage Vz to the sustain electrode Z as described above, the surface discharge between the scan electrode Y and the sustain electrode Z can be increased.

In addition, it is preferable that the absolute value Vs ₁ of the negative voltage (-Vs ₁ ) applied to the scan electrode Y in the sustain period is smaller than the sustain voltage Vs of the positive voltage. By reducing the magnitude of the negative voltage applied to the sustain electrode Z as described above, it is possible to prevent the counter discharge generated between the scan electrode Y and the address electrode X during the sustain period.

That is, immediately after the positive sustain voltage Vs is applied to the scan electrode Y, negative charges accumulate near the scan electrode Y, positive charges accumulate near the sustain electrode Z, and an address section near the address electrode X. At this time, negative charges formed in the stack are stacked, and when a negative voltage is applied to the scan electrode (Y), the counter discharge between the scan electrode (Y) and the address electrode (X) is the plane between the scan electrode (Y) and the sustain electrode (Z). May occur before discharge. As described above, when the counter discharge occurs first, negative charges accumulate near the scan electrode Y. Then, even when a positive voltage is applied to the scan electrode Y, the surface discharge between the scan electrode Y and the sustain electrode Z is reduced. It does not happen properly.

Therefore, as shown in FIG. 5, the negative voltage is applied to the scan electrode Y by making the absolute value of the negative voltage (−Vs ₁ ) applied to the scan electrode Y smaller than the magnitude of the positive voltage Vs. The surface discharge occurs before the time counter discharge, and when the negative voltage is applied, a positive voltage is applied to the sustain electrode Z to increase the voltage between the scan electrode Y and the sustain electrode Z, thereby increasing the strong surface discharge. To occur.

The magnitude of the negative voltage (-Vs ₁ ) applied to the scan electrode (Y) and the magnitude of the positive voltage (Vz) applied to the sustain electrode in the sustain period are the structure of the discharge cell, the scan electrode (Y) and The discharge start voltage between the address electrode X and the discharge start voltage between the scan electrode Y and the sustain electrode Z may be set in consideration.

Although a preferred embodiment of the present invention has been described in detail above, those skilled in the art to which the present invention pertains can make various changes without departing from the spirit and scope of the invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Accordingly, modifications to future embodiments of the present invention will not depart from the technology of the present invention.

According to the driving method of the plasma display panel according to the present invention configured as described above, when the positive voltage and the negative voltage are alternately applied to the scan electrode in the sustain period, and the negative voltage is applied to the scan electrode, the positive electrode is applied to the sustain electrode. By applying a voltage, it is possible to increase the surface discharge between the scan electrode and the sustain electrode in the sustain period, and to suppress the occurrence of the counter discharge between the scan electrode and the address electrode, thereby increasing the brightness of the display image and driving the plasma display panel. High margins can be secured.

Claims (6)

Discharge cells are defined in an area where a plurality of electrodes cross each other, and a unit frame for displaying an image is divided into a plurality of subfields, and each subfield is to be turned on among a reset period for initializing all discharge cells and all discharge cells. A method of driving a plasma display panel divided into an address section for distinguishing a cell from a cell that should not be turned on, and a sustain section for performing sustain discharge according to a gray scale weight assigned to each subfield in a discharge cell selected as a cell to be turned on, In the sustain period, a sustain pulse having an alternating first positive voltage and a second negative voltage is applied to a scan electrode, and a third positive polarity is applied to the sustain electrode when the second voltage is applied to the scan electrode. Voltage is applied, And a ground voltage is applied to the sustain electrode in the reset period and the address period. delete The method of claim 1, And the second voltage has an absolute value lower than that of the first voltage. The method of claim 3, wherein the second voltage is And when the second voltage is applied to the scan electrode, the voltage between the scan electrode and the address electrode is set to be lower than a discharge start voltage. The method of claim 4, wherein the discharge start voltage is And a minimum voltage to be applied to generate a discharge in the discharge cell. The method of claim 1, And a ground voltage is applied to the address electrode in the sustain period.

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