JP2770726B2 - Driving method of plasma display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of driving a plasma display panel used for an information terminal device, a display device of a personal computer, or an image display device of a television.

[0002]

2. Description of the Related Art A plasma display panel has characteristics such as a large capacity, a fast response speed, and a wide viewing angle among flat displays, and is suitable for a display with a large area. In particular, the ac-type plasma display panel shown in FIGS. 3 and 4 in which surface discharge between two electrodes on the same plane is the main discharge is a highly efficient and long-life panel having a memory function advantageous for obtaining high luminance. . In FIG. 3, 1 is a first insulating substrate made of glass, 2 is a second insulating substrate made of glass, 3 is a discharge electrode group made of a transparent conductive film such as Nesa (SnO ₂ ), and 4 is a thin metal film such as Al. 5 is a discharge gas space filled with a discharge gas such as a rare gas, 6 is an insulator partition sandwiched between the first insulating substrate 1 and the second insulating substrate 2 to partition between display cells, Reference numeral 7 denotes a phosphor that emits light by ultraviolet light generated by the discharge, 8 denotes an insulator that covers the electrodes, and 9 denotes a Mg0 protective film that protects the insulator from gas discharge. As shown in FIG. 4, the surface discharge electrode group 3 is composed of scanning electrodes 11 and sustaining electrodes 12 which are alternately arranged in parallel on the first insulating substrate.

Next, the discharging operation of the selected display cell will be described. Discharge starts when the pulse voltage applied to the scan electrode and the data electrode of the selected display cell, that is, the potential difference between the scan pulse and the data pulse exceeds the discharge start voltage. The charged particles move to the surface of the dielectric or phosphor on the electrode in accordance with the potential difference of the pulse voltage, and the charge is accumulated. Since the equivalent internal voltage, i.e., the wall voltage, due to the accumulated charges has a polarity opposite to that of the scan pulse and the data pulse, the effective voltage inside the cell decreases as the discharge grows, and the pulse voltage becomes constant. Even if the value is held, the discharge cannot be sustained and finally stops. Thereafter, when a sustain pulse, which is a pulse voltage having the same polarity as the wall voltage, is applied between the adjacent scan electrode and the sustain electrode, the wall voltage generated by charge accumulation on the scan electrode is superimposed as an effective voltage. You. Therefore, even if the voltage value of the sustain pulse is lower than the discharge starting voltage between the scan electrode and the sustain electrode when the wall voltage is not formed, the discharge occurs because the effective voltage applied to the discharge space exceeds the discharge starting voltage. Start. Further, after the discharge between the scan electrode and the sustain electrode, the wall voltage is similarly formed even when the discharge is maintained, so that the sustain pulse is repeatedly applied between the scan electrode and the sustain electrode. For example, the discharge can be maintained until the erase voltage for erasing the wall voltage and stopping the discharge is applied to the scan electrodes. This function is the above-mentioned memory function.

Utilizing such memory retention and pulse-like discharge characteristics, it is possible to display multi-gradation moving images. FIG. 2 shows an example of a voltage waveform applied to each electrode of the plasma display panel. In FIG. 2, V _{S 1} is a pulse voltage waveform applied to the first row of scan electrodes, V _{S 2} is a pulse voltage waveform applied to the scan electrodes of the second row, the pulse V _C is applied to the sustain electrode The voltage waveform, V _D, is the pulse voltage waveform applied to the data electrode.

First, a discharge called a priming discharge is performed between the sustain electrode and the scan electrode. By performing this discharge,
Since the priming particles are uniformly generated in the cell space of the entire panel, the discharge at the time of data writing can be performed at a low voltage without variation between cells. After the application of the priming pulse 17 and the priming erase pulse 18, a sustain pulse of a constant frequency is applied to the sustain electrode, and three types of high voltage pulses of the sustain pulse, the scan pulse, and the erase pulse are applied to the scan electrode paired with the sustain electrode. Are mixed and applied in a certain sequence. The sustain pulse applied to the scan electrode and the sustain electrode is set to a voltage within a memory margin, and their phases are opposite.

[0006] The scanning pulse is inserted between the sustain pulses and is sequentially applied to the scanning electrodes. The data electrodes
A data pulse is applied according to the timing of the scanning pulse. The data pulse and the scanning pulse are superimposed, and a write discharge occurs in the light emitting display cell. FIG. 2 illustrates a case where writing is not performed on the pixels connected to the scanning electrodes in the first row, and writing is performed on the pixels connected to the scanning electrodes in the second row. As shown in FIG. 2, the selected display cell is discharged by superimposing a scan pulse 13 applied to the scan electrode 11 and a data pulse 14 applied to the data electrode 4 in synchronization with this pulse, thereby discharging the selected display cell. Is written. Sustain discharge for light emission display is performed between scan electrode 11 and sustain electrode 12 by a sustain pulse. Also,
When erasing the display data, the sustain discharge is erased by applying an erasing pulse (not shown) having a voltage lower than the sustain pulse 15 or a narrow pulse width to the scan electrode 11.

[0007]

However, in the above-described conventional method of driving a plasma display panel having a surface discharge electrode structure, the data pulse voltage applied to the data electrode and the scan pulse voltage applied to the scan electrode at the time of writing discharge are reduced. Needs to be large. Especially,
Since the scan pulse voltage cannot be increased so much to prevent erroneous discharge, the data pulse voltage increases. Therefore, in a plasma display panel having a large area and a large display capacity, a large number of high-withstand-voltage driving circuits for applying a high voltage to a data pulse when writing display data are required.

An object of the present invention is to provide a driving method which enables a reliable write operation with a low data pulse voltage.

[0009]

A driving method according to the present invention comprises a scan electrode group consisting of scan electrodes formed on the same plane in a display cell and a sustain electrode for discharging between the scan electrodes. Sustain electrode group, also includes a data electrode group consisting of data electrodes for supplying display data orthogonal to the scan electrode group and the sustain electrode group, between the scan electrode group and the sustain electrode group and the data electrode group In a method for driving an AC discharge memory type plasma display panel in which a discharge gas is sealed, a pulse voltage which is immediately before application of a data pulse for supplying display data and at which a discharge occurs between a scan electrode and a sustain electrode is applied. An auxiliary pulse voltage having a polarity opposite to that of the data pulse is applied to the data electrode during a period including the data pulse.

[0010]

In the present invention, an auxiliary pulse voltage having a polarity opposite to that of the data pulse is applied to the data electrode before writing the display data and during a period in which a discharge occurs between the sustain electrode and the scan electrode. By applying the auxiliary pulse, it is possible to accumulate charges on the data electrodes even when no discharge occurs between the data electrodes and the scan electrodes or the sustain electrodes, and the accumulated charges form a wall voltage. .
By selecting the polarity of the auxiliary pulse so that the wall voltage and the externally applied voltage due to the data pulse and the scanning pulse at the time of writing are superimposed, the writing discharge can be started even at a data pulse voltage lower than the conventional one. . As a result, a stable write operation can be performed using a lower data pulse voltage than in the related art, and a favorable display with multiple gradations can be realized.

[0011]

Embodiments of the present invention will be described with reference to the drawings. Referring to FIG. 1 showing a first embodiment of a drive waveform for realizing the drive method of the present invention, V _S1 is a pulse voltage waveform applied to the scan electrode in the first row, and V _S2 is a scan in the second row. pulse voltage waveform applied to the electrodes, V _C is a pulse voltage waveform applied to the sustain electrodes, V _D is a pulse voltage waveform applied to the data electrodes, the polarity of all pulse voltages than the data pulses are negative. An auxiliary pulse 16 having a polarity opposite to that of the data pulse applied at the time of display data writing, that is, a negative polarity, is applied to all data electrodes, and a discharge occurs between the scanning electrode and the sustain electrode immediately before performing the writing operation. It is applied at least during a period including the priming erase pulse 18 which is the last pulse voltage during the priming discharge period. By applying the negative auxiliary pulse voltage, the positively charged particles generated at the time of priming discharge are accumulated on the data electrode, and are superimposed on the positive data pulse at the time of the write discharge to form a discharge space. A high electric field can be formed therein. If the auxiliary pulse is applied at the time of discharge formation by the priming erase pulse, a wall voltage can be formed on the data electrode. However, it is possible to use the movement of the charge remaining in the space due to the potential difference between the data electrode and the scan electrode. For example, since a larger wall voltage can be formed on the data electrode, it is preferable to keep applying the voltage until after the priming erase pulse is cut off.

Next, the discharging operation of the selected display cell of the present invention will be described in more detail. When a discharge is formed between two electrodes in a three-electrode type plasma display panel, if a non-zero potential is applied to the remaining one electrode, a charge corresponding to the potential difference accumulates on the dielectric or phosphor surface on the electrode. Is done. Priming digestion pulse 1
When a negative auxiliary pulse is applied to the data electrode at the time of application of 8, the positive electric charge is accumulated.

Usually, a writing discharge occurs when the potential difference between the scanning pulse and the data pulse of the selected display cell exceeds the discharge starting voltage. However, by accumulating the charges as described above, the effective voltage inside the cell increases, and even when the potential difference between the scan electrode and the sustain electrode when the wall voltage is not formed is lower than the discharge start voltage, the effective voltage is reduced. Discharge can be started beyond the starting voltage.

In the first embodiment, the application period of the auxiliary pulse is a period including the priming erase pulse. However, the application period of the auxiliary pulse is immediately before the operation of writing the display data and between the sustain electrode and the scan electrode. , The discharge may be performed during a period other than the period including the priming erase pulse. For example, FIG. 6 shows a driving waveform of the second embodiment using the present invention when an image is displayed by the field division method as shown in FIG. At the beginning of the subfield 20-1, an auxiliary pulse 16-1 is applied at the time of priming erase discharge. When a discharge occurs during display selection, the wall voltage on the data electrode is extinguished, and the write voltage of the display cell increases after the selected subfield. Therefore, the voltage is applied at the end of each subfield. Then, the auxiliary pulse 16-2 is applied to the data electrode immediately before the next writing operation, and in synchronization with the erasing pulse voltage 19 of the sustain discharge in which a discharge occurs between the sustain electrode and the scan electrode at the end. Thus, a wall voltage can be formed on the data electrode. However, at this time, the timing of writing and erasing the display data overlaps with only one auxiliary pulse, so that the auxiliary pulse is divided for each erasing pulse as shown in FIG. 6 so as not to hinder the next writing operation. It is necessary to apply or divide the auxiliary pulse every several lines, though not shown here.

On the other hand, in the halftone display as shown in FIG. 7, one auxiliary pulse may be applied to the erasing period as in the first embodiment. This is because when the display data write operation and the sustain operation are separated in time,
This is because data erasing is performed all at once just before the writing period starts. FIG. 8 shows a drive waveform at this time as a third embodiment.

[0016]

As is apparent from the above description, in the above-mentioned AC discharge memory type plasma display panel, an auxiliary pulse having a polarity opposite to that of the data pulse is applied to the data electrode, and is superimposed on the data electrode. By forming the wall voltage, the writing discharge can be easily performed with a lower data pulse voltage than in the related art. In addition, by using the driving method of the present invention, driving of the panel becomes easy and reliable, and a plasma display panel having good display quality and driving characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a method of driving a surface discharge type plasma display panel using the present invention.

FIG. 2 is an example of a method of driving a conventional surface discharge AC memory type plasma display panel.

FIG. 3 is a structural sectional view of a surface discharge AC memory type plasma display panel.

FIG. 4 is a plan view of a surface discharge AC memory type plasma display panel.

FIG. 5 is a first example of a timing chart of halftone TV display.

FIG. 6 shows a second embodiment of a method of driving a surface discharge type plasma display panel using the present invention.

FIG. 7 is a second example of a timing chart of halftone TV display.

FIG. 8 shows a third embodiment of a method of driving a surface discharge type plasma display panel using the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 First insulating substrate 2 Second insulating substrate 3 Surface discharge electrode 4 Data electrode 5 Discharge gas space 6 Insulator partition wall 7 Phosphor 8 Insulator 9 Protective film 10 Display cell 11 Scan electrode 12 Sustain electrode 13 Scan pulse 14 Data pulse 15 Sustain pulse 16 Auxiliary pulse 17 Priming pulse 18 Priming erase pulse 19 Erase pulse 20-1 to 20-7 Subfield

Claims (1)

(57) [Claims] 1. A scan electrode group consisting of scan electrodes formed on the same plane in a display cell, and a sustain electrode group consisting of sustain electrodes for maintaining discharge between the scan electrodes, and the scan electrode group. An AC discharge memory type plasma comprising a data electrode group consisting of data electrodes for supplying display data orthogonal to the sustain electrode group, wherein a discharge gas is sealed between the scan electrode group and the sustain electrode group and the data electrode group. In the method for driving a display panel, the polarity is opposite to that of the data pulse immediately before the application of a data pulse for supplying display data and during a period including a pulse voltage at which a discharge occurs between a scan electrode and a sustain electrode. A driving method for an AC discharge memory type plasma display panel, wherein the auxiliary pulse voltage is applied to a data electrode.