JP2770847B2 - Driving method of plasma display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for driving a plasma display panel, and more particularly to a method for driving an AC memory type plasma display panel.

[0002]

2. Description of the Related Art Generally, a plasma display panel (hereinafter abbreviated as PDP) has a thin structure, has no flicker, has a large display contrast ratio, and can have a relatively large screen, and has a response speed. It has a number of features, such as being fast, self-luminous, and capable of emitting multicolor light by using a phosphor. For this reason, in recent years, it has been widely used in the field of computer-related display devices and the field of color image display.

[0003] Depending on the operation method, this PDP has an AC type in which electrodes are covered with a dielectric and indirectly operates in an AC discharge state, and a PDP in which the electrodes are exposed to a discharge space and are in a DC discharge state. There is a DC type that operates. Furthermore,
The AC type includes a memory operation type using a memory of a discharge cell as a driving method and a refresh operation type not using the memory. The brightness of the PDP is proportional to the number of discharges, that is, the number of repetitions of the pulse voltage. The refresh type described above is mainly used for a PDP having a small display capacity because the brightness decreases as the display capacity increases.

FIG. 4 is a cross-sectional view showing the structure of one display cell of an AC memory operation type PDP. This display cell is composed of two insulating substrates 1 on the back and front made of glass.
And 2 and a transparent scanning electrode 3 formed on the insulating substrate 2
And the transparent sustain electrode 4, the trace electrodes 5 and 6 arranged so as to overlap the scan electrode 3 and the sustain electrode 4 to reduce the electrode resistance value, and the scan electrode 3 and the sustain electrode 4 on the insulating substrate 1. A data electrode 7 formed orthogonally; a discharge gas space 8 in which the space between the insulating substrates 1 and 2 is filled with a discharge gas made of helium, neon, xenon, or the like, or a mixture thereof; Partition wall 9 for securing display and display cells, phosphor 11 for converting ultraviolet light generated by the discharge of the discharge gas into visible light 10, dielectric 12 for covering scan electrode 3 and sustain electrode 4, and It comprises a protective layer 13 made of magnesium oxide or the like for protecting the dielectric 12 from discharge, and a dielectric 14 covering the data electrode 7.

Next, the discharging operation of the selected display cell will be described with reference to FIG. When a pulse voltage exceeding the discharge threshold voltage, that is, a write pulse is applied between the scan electrode 3 and the data electrode 7, that is, a write pulse is applied to start the discharge, positive and negative charges corresponding to the polarity of the write pulse are generated on both sides of the dielectric material. 1
It is attracted to the surfaces of 2 and 14 causing a charge buildup. Since the equivalent internal voltage due to the accumulation of the charges, that is, the wall voltage, has the opposite polarity to the voltage of the write pulse, the effective voltage inside the cell decreases as the discharge grows, and the voltage of the write pulse becomes constant. Even if the value is maintained, the discharge cannot be maintained and finally stops. Thereafter, when a sustain pulse having the same polarity as the wall voltage is applied between the adjacent scan electrode 3 and sustain electrode 4, the wall voltage is superimposed as an effective voltage. Even if the amplitude is low, it is possible to discharge beyond the discharge threshold. Therefore, the discharge can be maintained by continuously applying the sustain pulse between the scan electrode 3 and the sustain electrode 4. This function is the above-mentioned memory function. Further, by applying an erasing pulse, which is a pulse having a wide width and a low voltage or a pulse having a narrow width of about a sustain pulse voltage, to neutralize the wall voltage, to the scan electrode 3 or the sustain electrode 4. Can be stopped.

In order to obtain a stable write discharge (discharge between the scan electrode and the data electrode) in an AC memory type PDP, it is effective to perform a preliminary discharge prior to the write discharge. The effect of the pre-discharge is to optimize the wall charge on each electrode and to sufficiently leave active particles (charged particles, excited particles, etc.) in the discharge space, so that writing for subsequent display cell selection can be performed. It is an object of the present invention to shorten a discharge delay time in a discharge and obtain writing characteristics at high speed and with little time variation.

FIG. 5 shows an electrode arrangement of a plasma display panel having the display cells shown in FIG.

The panel shown in FIG. 5 is a panel for dot matrix display arranged in a matrix of j × k rows and columns, and has scanning electrodes Sc1, Sc1 arranged in parallel to each other.
Scj, ..., Scj and sustain electrodes Su1, Su2, ..., Suj;
Data electrodes D1, D2,..., Dk arranged orthogonally to these scanning electrodes and sustaining electrodes.

FIG. 6 shows sustain electrodes Su1, Su2,..., Suj.
And a common sustain electrode driving waveform Wu applied to the
, Scj, scan electrode driving waveforms Ws1,
Ws2,..., Wsj and a data electrode drive waveform Wd applied to the data electrode Di (1 ≦ i ≦ k). One cycle of driving is composed of a preliminary discharge period A, a write discharge period B, and a sustain discharge period C, and this is repeated to obtain a desired image display.

In the pre-discharge period A, first, the sustain electrodes Su1,
A pre-discharge pulse Pp is applied to Su2,..., Suj to cause all the display cells to emit light. Subsequently, the scanning electrodes Sc1, Sc2,.
A pre-discharge erase pulse Ppe is applied to the
Erase the wall charge generated by p.

Next, in the write discharge period B, the scan electrodes S
The scan pulse Pw is applied in order from c1 to the scan electrode Scj,
A display cell is selectively illuminated by applying a data pulse Pd to the data electrode in synchronism with the scanning pulse Pw.

Lastly, in the sustain discharge period, sustain pulses Pu and Ps are alternately applied to the sustain electrodes and the scan electrodes, and the display cells which have selectively emitted light in the write discharge period are caused to emit light. After the number of sustain discharges at which a desired luminance is obtained, one field is completed by finally applying the sustain erase pulse Pe.

[0013]

In the conventional driving method, since the inside of the discharge cells is in a neutralized state after the sustain erasure discharge, the discharge must be generated by the unipolar pulse by the preliminary discharge pulse during the preliminary discharge. , A large pre-discharge pulse voltage was required.

If the repetition period of one field is controlled by an external input signal, the operation shifts to the next field unless a predetermined time has elapsed after the completion of the predetermined preliminary discharge, write discharge, and sustain discharge. Therefore, the time from the sustain erasure discharge to the pre-discharge in the next field becomes longer, and the pre-discharge becomes more unstable.

An object of the present invention is to solve the above-mentioned problems, to provide a plasma display panel driving method capable of stabilizing a preliminary discharge of the plasma display panel and expanding an operation margin.

[0016]

According to the present invention, there are provided a plurality of scan electrodes corresponding to scan lines of a display cell formed on the same plane, and a data writing device which is orthogonal to the scan electrodes and driven in accordance with display data. In a method for driving a plasma display including a plurality of data electrodes,
One field has a write discharge period for selectively emitting light of a desired display cell, a sustain discharge period for sustaining light emission of the selected display cell during the write discharge period, and a preliminary discharge period preceding the write discharge period. The discharge period ends with the sustain pulse, and the inter-electrode potential at the time of applying the final sustain pulse is opposite to the inter-electrode potential at the time of applying the pre-discharge pulse during the pre-discharge period of the next field. A method for driving a plasma display panel, characterized in that the pulse width is made larger than the pulse width of the sustain pulse before the last sustain pulse.

Further, according to the present invention, there is provided a method of driving a plasma display panel, wherein the end of the last sustain pulse is made simultaneously with the start of a pre-discharge pulse applied during a pre-discharge period of the next field. .

[0018]

[0019]

[0020]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a timing chart showing driving waveforms in the first embodiment of the present invention. Similar to the above-mentioned prior art, FIG. 1 shows a timing chart for driving the plasma display panel having the electrode arrangement shown in FIG. Things. here,
Wu is a common sustain electrode drive waveform applied to sustain electrodes Su1, Su2,..., Suj, and Ws1, Ws2,..., Wsj are scan electrode drive waveforms applied to scan electrodes Sc1, Sc2,. And Wd is the data electrode Di (1 ≦ i ≦
k) Data electrode driving waveform applied to k).

One cycle of driving is composed of a preliminary discharge period A, a write discharge period B, and a sustain discharge period C. These are repeated to obtain a desired image display. In the pre-discharge period A, a pre-discharge pulse Pp is first applied to the sustain electrodes Su1, Su2,..., Suj to cause all the display cells to emit light. Then, scan electrode Sc
The pre-discharge erase pulse Ppe is applied to 1, Sc2,..., Scj to erase the wall charges generated by the pre-discharge pulse Pp.

Subsequently, in the write discharge period B, a scan pulse Pw is applied in order from the scan electrode Sc1 to the scan electrode Scj, and a data pulse Pd is applied to the data electrode Di in synchronization with the scan pulse Pw. Is selectively emitted. The above driving sequence is the same as in the conventional example.

Lastly, in the sustain discharge period C, sustain pulses Pu and Ps are alternately applied to the sustain electrodes and the scan electrodes, and the display cells which have selectively emitted light during the write discharge period are caused to emit light. After the number of sustain discharges at which a desired luminance is obtained, the sustain pulse Pse is applied as the final sustain pulse to the scan electrodes Sc1, Sc2,..., Scj, and one field is completed.

Since the predischarge pulse Pp of the subsequent field is applied to the sustain electrodes Su1, Su2,..., Suj, the potential difference between the scan electrode and the sustain electrode is determined by comparing the predischarge pulse Pp with the sustain pulse Pse. There is a reverse potential relationship with the time of application. Therefore, when the pre-discharge pulse is applied, the internal voltage of these charges is superimposed on the pre-discharge pulse voltage due to the attraction of the space charge or wall charge in the display cell toward each electrode by the application of the final sustain pulse Pse. Is promoted, and high-speed and stable discharge characteristics can be obtained.

The sustain pulse Pse is arranged immediately before the predischarge pulse of the next field.
If the pulse width is equal to or larger than Ps, the effect is expanded.

FIG. 2 is a timing chart showing driving waveforms according to the second embodiment of the present invention. The basic sequence of the pre-discharge and the write discharge is the same as in the first embodiment, and a description thereof will be omitted. In this embodiment,
In the sustain discharge period C, the last sustain pulse Pse is applied with a shorter time interval from the end of the previous sustain pulse, and the application time is further extended to just before the preliminary discharge pulse of the next field. According to the present invention, the sustain discharge with the final sustain pulse Pse is also stabilized, and the function of retaining wall charges and space charges until immediately before the next preliminary discharge is enhanced,
An increasingly stable preliminary discharge can be realized.

In particular, the field cycle is determined by an external signal, and the cycle is determined by a driving repetition cycle, ie, a preliminary discharge,
Even if it is larger than the sum of the series of operations of the write discharge and the sustain discharge, from the end of the drive sequence specified in one field to the start of the next field,
Since the last sustain pulse Pse is continuously applied, the preliminary discharge can be stabilized regardless of the field period of the external signal.

FIG. 3 is a timing chart showing driving waveforms according to the third embodiment of the present invention. Also in this embodiment, the basic sequence of the preliminary discharge and the write discharge is the same as in the first embodiment. In the present invention,
In the sustain discharge period C, the last sustain pulse Pse is applied to the sustain electrode, and the polarity thereof is set to the opposite positive polarity to the preliminary discharge pulse Pp. The potential difference between the scan electrode and the sustain electrode is
The operation is reversed between when the last sustain pulse is applied and when the preliminary discharge pulse is applied, and the same effect as that of the second embodiment shown in FIG. 2 can be obtained.

In each of the above embodiments, the case of repeating one field has been described as an example. However, the method of driving a plasma display panel according to the present invention employs one field to realize multi-gradation display. Is divided into a plurality of subfields, and preliminary discharge is performed in each subfield,
The present invention is also applicable to a case where a sequence of write discharge and sustain discharge is provided.

Similarly, a surface discharge type AC plasma display panel having a three-electrode structure has been described as an example. However, the driving method of the plasma display panel of the present invention is not limited to this type of display panel. Of course, the present invention can be applied to other types of plasma display panels such as an opposed AC plasma display panel having an electrode structure.

[0032]

As described above, according to the driving method of the plasma display panel of the present invention, the sustain pulse having a polarity opposite to that of the preliminary discharge pulse is provided immediately before the preliminary discharge pulse. Discharge can be stabilized. Further, the start of the last sustain pulse is set immediately after the previous sustain pulse, so that a more stable preliminary discharge can be realized.

[Brief description of the drawings]

FIG. 1 is a timing chart showing voltage driving waveforms according to a first embodiment of the present invention.

FIG. 2 is a timing chart showing voltage driving waveforms according to a second embodiment of the present invention.

FIG. 3 is a timing chart showing a voltage driving waveform according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of an AC memory operation type PDP.

FIG. 5 is a plan view showing an electrode arrangement of an AC memory operation type PDP.

FIG. 6 is a timing chart showing an example of a driving voltage waveform in a conventional example.

[Explanation of symbols]

 A preliminary discharge period B write discharge period C sustain discharge period Pp preliminary discharge pulse Ppe preliminary discharge erase pulse Pw scan pulse Pu, Ps sustain pulse Pse final sustain pulse Pe sustain erase pulse Pd data pulse 1, insulating substrate 3, Sc1 to Scj scan electrode 4, Su1 to Suj sustain electrode 5, 6 trace electrode 7, D1 to Dk data electrode 8 discharge gas space 9 partition 10 visible light 11 phosphor 12, 14 dielectric 13 protective film 15 PDP panel 16 display cell

Claims (2)

(57) [Claims] 1. A semiconductor device comprising: a plurality of scan electrodes corresponding to scan lines of a display cell formed on the same plane; and a plurality of data electrodes for writing data which are orthogonal to the scan electrodes and driven in accordance with display data. In a method for driving a plasma display, one field selectively discharges a desired display cell in a write discharge period, a sustain discharge period in which a display cell selected in the write discharge period is sustained to emit light, and a preliminary discharge period prior to the write discharge period. A discharge period, wherein the sustain discharge period ends with a sustain pulse, and the potential between the electrodes when the last sustain pulse is applied is opposite to the potential between the electrodes when the pre-discharge pulse is applied during the pre-discharge period of the next field. Wherein the pulse width of the last sustain pulse is larger than the pulse width of the sustain pulse before the last sustain pulse. Display panel driving method. 2. The method of driving a plasma display panel according to claim 1, wherein the ending of the last sustain pulse is performed simultaneously with the start of a pre-discharge pulse applied in a pre-discharge period of a next field.