KR20020020385A - Driving Method of Plasma Display Panel - Google Patents

Abstract

PURPOSE: A method of driving plasma display panel are provided to be capable of improving a light emitting efficiency. CONSTITUTION: A frame is divided into a plurality of sub-fields, and each sub-field is divided into an address discharge period, a sustain discharge period, and an erase period. During the reset period, a reset discharge for resetting a discharge cell is performed by supplying a reset pulse to the second trigger electrode(Tz) of the discharge cell. During the address period, scan pulses(C1-Cn) are sequentially supplied to the first trigger electrode(Ty), and a data pulse(Va) synchronized with the scan pulse is applied to an address electrode. During the sustain period, a sustain pulse is alternately applied between the first trigger electrode(Ty) and a scan/sustain electrode(Sy) and between the second trigger electrode(Tz) and a common sustain electrode(Sz).

Description

Driving method of plasma display panel {Driving Method of Plasma Display Panel}

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

Plasma Display Panel (hereinafter referred to as "PDP") is a display device using visible light generated from a phosphor when vacuum ultraviolet rays generated by gas discharge excite the phosphor. PDP is thinner and lighter than Cathode Ray Tube (CRT), which has been the mainstay of display means, and has the advantage of being able to realize high definition large screen. PDP is composed of a plurality of discharge cells arranged in a matrix form, one discharge cell constitutes a pixel of the screen.

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

Referring to FIG. 1, a discharge cell of a conventional three-electrode AC surface discharge type PDP includes a scan / sustain electrode 12Y and a common sustain electrode 12Z formed on an upper substrate 10, and a lower substrate 18. The formed address electrode 20X is provided. The upper dielectric layer 14 and the passivation layer 16 are stacked on the upper substrate 10 having the scan / sustain electrode 12Y and the common sustain electrode 12Z 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 discharge 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 20X 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 20X is formed in the direction crossing the scan / sustain electrode 12Y and the common sustain electrode 12Z. The partition wall 24 is formed in parallel with the address electrode 20X 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. Inert gas for gas discharge is injected into the discharge space provided between the upper substrate 10 / lower substrate 18 and the partition wall 24.

The AC surface discharge type PDP is driven by dividing one frame into several subfields having different discharge times in order to express gray level of an image. Each subfield is further divided into a reset period for uniformly causing discharge, an address period for selecting a discharge cell, and a sustain period for expressing gray scale according to the number of discharges. For example, when the image is to be displayed with 256 gray levels, the frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields. Each of the eight subfields is further divided into an address period and a sustain period. Here, the reset period and the address period 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) in each subfield. Is increased. In this way, since the sustain period is different in each subfield, the gray level of the image can be expressed.

Here, in the reset period, a reset pulse is supplied to the scan / sustain electrode 12Y to generate a reset discharge. In the address period, scan pulses are supplied to the scan / sustain electrodes 12Y, and data pulses are supplied to the address electrodes 20X to generate address discharges between the two electrodes 12Y and 20X. During the address discharge, wall charges are formed in the upper and lower dielectric layers 14 and 22. In the sustain period, sustain discharge occurs between the two electrodes 12Y and 12Z by an alternating current signal alternately supplied to the scan / sustain electrode 12Y and the common sustain electrode 12Z.

However, in the conventional AC surface discharge PDP, the sustain discharge space is concentrated in the center of the upper substrate 10, thereby decreasing the utilization of the discharge space. Accordingly, there is a problem that the discharge area is reduced and the luminous efficiency is reduced. In order to solve this problem, a 5-electrode AC surface discharge type PDP as shown in FIG. 2 has been proposed.

2 is a perspective view showing a discharge cell structure of a conventional 5-electrode AC surface discharge type PDP.

Referring to FIG. 2, the conventional 5-electrode AC surface discharge type PDP is positioned at the edges of the discharge cells and the first and second trigger electrodes 34Y and 34Z formed on the upper substrate 30 to be positioned at the center of the discharge cells. The scan / sustain electrode 32Y and the common sustain electrode 32Z, the trigger electrodes 34Y and 34Z, the scan / sustain electrode 32Y and the common sustain electrode 32Z formed on the upper substrate 30 The address electrode 42X is formed in the center of the lower substrate 40 in the direction perpendicular to each other. The upper dielectric layer 36 and the protective film 38 are formed on the upper substrate 30 having the scan / sustain electrode 32Y, the first trigger electrode 34Y, the second trigger electrode 34Z, and the common sustain electrode 32Z side by side. This is laminated. The lower dielectric layer 44 and the barrier rib 46 are formed on the lower substrate 40 on which the address electrode 42X is formed, and the phosphor layer 48 is coated on the surfaces of the lower dielectric layer 44 and the barrier rib 46. The trigger electrodes 34Y and 34Z formed at a narrow interval Ni at the center of the discharge cell are used to start sustain discharge by receiving an AC pulse during the sustain period. The scan / sustain electrode 32Y and the common sustain electrode 32Z formed at a wide interval Wi at the edge of the discharge cell are supplied with an alternating pulse during the sustain period, and then discharge is started between the trigger electrodes 34Y and 34Z. Used to maintain. In order to drive the five-electrode PDP, the waveform shown in FIG. 3 is applied.

Referring to FIG. 3, the conventional 5-electrode AC surface discharge type PDP is driven by dividing one frame into several subfields having different discharge times in order to express 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 expressing gray scale according to the number of discharges. In the reset period, a reset pulse is supplied to the second trigger electrode Tz of the discharge cell to generate a reset discharge for initializing the discharge cell. At this time, a DC voltage is supplied to the address electrode X to prevent erroneous discharge. In the address period, the scan pulse C is sequentially supplied to the first trigger electrode Ty, and the data pulse Va synchronized with the scan pulse C is supplied to the address electrode X. At this time, an address discharge occurs in the discharge cell supplied with the data pulse Va. In the sustain period, sustain pulses are alternately applied between the first trigger electrode Ty and the scan / sustain electrode Sy, the second trigger electrode Tz, and the common sustain electrode Sz. In this case, the voltage Vt applied to the trigger electrodes Ty and Tz has a level lower than the voltage Vs applied to the scan / sustain electrode Sy and the common sustain electrode Sz. During the sustain period, the address electrode X is supplied with a direct current voltage for preventing erroneous discharge.

The sustain discharge process will be described in detail with reference to FIGS. 4A and 4B. When the sustain pulse is applied to the first trigger electrode Ty, the scan / sustain electrode Sy, the second trigger electrode Tz, and the common sustain electrode Sz, first, the first trigger electrode Ty and the second trigger electrode are first applied. Discharge occurs between (Tz). After the discharge occurs between the first trigger electrode Ty and the second trigger electrode Tz, the second trigger electrode Tz and the common sustain electrode Sz or the first trigger electrode Ty and the scan / sustain electrode Sy Discharge occurs in the liver. After the discharge occurs between the second trigger electrode Tz and the common sustain electrode Sz or the first trigger electrode Ty and the scan / sustain electrode Sy, between the scan / sustain electrode Sy and the common sustain electrode Sz. Discharge occurs. At this time, even if the interval Wi between the scan / sustain electrode Sy and the common sustain electrode Sz is large, the first and second trigger electrodes Ty and Tz and the second trigger electrode Tz and the common sustain electrode Sz are present. Or a priming discharge between the first trigger electrode Ty and the scan / sustain electrode Sy may cause a discharge even with a sustain pulse of a relatively low voltage level. In this manner, the discharge is started using the trigger electrodes Ty and Tz formed at a narrow interval Ni, thereby suppressing an increase in the discharge start voltage, while the scan / sustain electrode Sy and the common sustain electrode ( A long discharge path between Sz) can cause sustain discharge.

The discharge contributing to the luminance in the five-electrode PDP operating as described above is the discharge occurring between the scan / sustain electrode Sy and the common sustain electrode Sz. The discharges occurring between the trigger electrodes Ty and Tz and the second trigger electrode Tz and the common sustain electrode Sz or between the first trigger electrode Ty and the scan / sustain electrode Sy are the scan / sustain electrodes Sy. And a discharge for generating charged particles such that a discharge can occur between the common sustain electrode Sz. Therefore, microdischarge should occur between the trigger electrodes Ty and Tz and the second trigger electrode Tz and the common sustain electrode Sz or between the first trigger electrode Ty and the scan / sustain electrode Sy. However, a strong discharge occurs between the trigger electrodes Ty and Tz formed at narrow intervals Ni. In addition, a strong discharge occurs between the second trigger electrode Tz and the common sustain electrode Sz or between the first trigger electrode Ty and the scan / sustain electrode Sy. As such, when a strong discharge occurs between the trigger electrodes Ty and Tz and the second trigger electrode Tz and the common sustain electrode Sz or the first trigger electrode Ty and the scan / sustain electrode Sy, the scan / sustain electrode The discharge between (Sy) and the common sustain electrode (Sz) is weakened, which lowers the luminous efficiency of the PDP.

Accordingly, an object of the present invention is to provide a method of driving a plasma display panel which can improve luminous efficiency.

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

2 is a perspective view showing a discharge cell structure of a conventional 5-electrode AC surface discharge plasma display panel.

3 is a waveform diagram illustrating driving waveforms applied to the 5-electrode plasma display panel shown in FIG. 2;

4A to 4B are cross-sectional views illustrating sustain discharges generated in the plasma display panel by the driving waveforms shown in FIG.

5 is a waveform diagram showing driving waveforms supplied to a plasma display panel according to an embodiment of the present invention;

6A to 6B are cross-sectional views illustrating sustain discharges generated in the plasma display panel by the driving waveforms shown in FIG.

<Description of Symbols for Main Parts of Drawings>

10,30: upper substrate 12Y, 32Y: scan / sustain electrode

12Z, 32Z: common sustain electrode 14,22,36,44: dielectric layer

16,38: protective film 18,40: lower substrate

20X, 42X: address electrode 24, 46: partition wall

26,48 phosphor layer 34Y, 34Z trigger electrode

In order to achieve the above object, the driving method of the plasma display panel according to the present invention includes applying a sustain pulse alternately to the sustain electrode pairs during the sustain period, and applying a pulse signal to the address electrode during the sustain period.

Other objects and features of the present invention in addition to the above objects will become 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 6B.

5 is a waveform diagram showing a driving waveform of the plasma display panel of the present invention.

Referring to FIG. 5, the five-electrode AC surface discharge type PDP according to the present invention is driven by dividing one frame into several subfields having different discharge times in order to express the gray level 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 expressing gray scale according to the number of discharges. In the reset period, a reset pulse is supplied to the second trigger electrode Tz of the discharge cell to generate a reset discharge for initializing the discharge cell. At this time, a DC voltage is supplied to the address electrode X to prevent erroneous discharge. In the address period, the scan pulse C is sequentially supplied to the first trigger electrode Ty, and the data pulse Va synchronized with the scan pulse C is supplied to the address electrode X. At this time, an address discharge occurs in the discharge cell supplied with the data pulse Va. In the sustain period, sustain pulses are alternately applied between the first trigger electrode Ty and the scan / sustain electrode Sy, the second trigger electrode Tz, and the common sustain electrode Sz. In this case, the voltage Vt applied to the trigger electrodes Ty and Tz has a level lower than the voltage Vs applied to the scan / sustain electrode Sy and the common sustain electrode Sz. In the sustain period, a pulse having a frequency twice that of the sustain pulses applied to the respective trigger electrodes Ty and Tz, the scan / sustain electrode Sy, and the common sustain electrode Sz is present in the address electrode X. Supplied. As such, the pulses supplied to the address electrode X are alternately supplied to the first trigger electrode Ty and the scan / sustain electrode Sy, the second trigger electrode Tz, and the common sustain electrode Sz. It is supplied in synchronization with the pulse. The pulse supplied to the address electrode X has a voltage value of Vs / 3 or more lower than the voltage Vs applied to the scan / sustain electrode Sy and the common sustain electrode Sz. The sustain discharge process will be described in detail with reference to FIGS. 6A and 6B. First, a sustain pulse is applied to the first trigger electrode Ty, the scan / sustain electrode Sy, the second trigger electrode Tz, and the common sustain electrode Sz, and has a voltage value of Vs / 3 or more at the address electrode. When a pulse is applied, a discharge occurs between the scan / sustain electrode Sy or the common sustain electrode Sz and the address electrode X. After the discharge occurs between the scan / sustain electrode Sy or the common sustain electrode Sz and the address electrode X, a sustain discharge occurs between the scan / sustain electrode Sy and the common sustain electrode Sz. That is, a weak opposite discharge is generated between the scan / sustain electrode Sy, the common sustain electrode Sz, and the address electrode X. At this time, only the wall charges are formed in the trigger electrodes Ty and Tz, and thus the sustain discharges are easily generated. As compared with the conventional 5-electrode PDP, in the present invention, only one weak discharge occurs before the sustain discharge occurs between the scan / sustain electrode Sy and the common sustain electrode Sz. Therefore, in the present invention, the luminous efficiency of the PDP can be improved. In addition, in the present invention, since no discharge occurs between the trigger electrodes Ty and Tz, a low voltage for forming wall charges may be applied to the trigger electrodes Ty and Tz. That is, the power consumption of the PDP can be minimized. In addition, in the present invention, since the address electrode X and the scan / sustain electrode Sy or the common sustain electrode Sz are used to initiate the sustain discharge, the trigger electrodes Ty and Tz positioned at the center of the discharge cell are used. Can be removed. That is, even when the trigger electrodes Ty and Tz are removed, the light emission efficiency of the PDP can be improved by widening the interval between the scan / sustain electrode Sy and the common sustain electrode Sz.

As described above, according to the driving method of the plasma display panel according to the present invention, the sustain discharge is initiated by causing a weak discharge between the scan / sustain electrode or the common sustain electrode and the address electrode. Therefore, the luminous efficiency of the plasma display panel can be improved. In addition, since the trigger electrodes do not discharge in the sustain period and form only wall charges, voltages applied to the trigger electrodes can be minimized. Furthermore, in the present invention, the manufacturing cost of the plasma display panel can be reduced by removing trigger electrodes that are not used for sustain discharge.

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 (5)

A discharge cell is formed at an intersection of a sustain electrode pair and an address electrode, and is driven by being divided into a reset period, an address period, and a sustain period. Alternately applying sustain pulses to the sustain electrode pairs during the sustain period; And applying a pulse signal to the address electrode during the sustain period. The method of claim 1, And said pulse signal has a frequency twice that of said sustain pulse. The method of claim 1, And the pulse signal is supplied in synchronization with all of the sustain pulses alternately applied to each of the sustain electrode pairs. The method of claim 1, And alternately applying a pulse having a lower voltage than the sustain pulse to trigger electrodes that are additionally provided between the sustain electrode pairs. The method of claim 1, And the voltage value of the pulse signal is 1/3 or more of the sustain pulse voltage value.