JPH02242292A - Method for driving plasma display panel - Google Patents

Abstract

PURPOSE:To prevent the generation of an unerased part while taking a large voltage margin by selectively impressing the holding pulses of the same polarity as the polarity of writing pulses to a Y electrode to be written at the time of brightness adjustment prior to the impression of the writing pulses. CONSTITUTION:Driving waveform pulses are so formed as to impress the holding pulse PSS of the same polarity as to be continuous with the writing pulse PW prior to the impression timing of the pulse PW. The holding pulse PSS is impressed prior to the writing pulse PW to the Y electrode. An increase in discharge current by such impression is averted and the voltage impressed in the gap between the X electrode and the Y electrode is not increased and, therefore, the accumulation of an overvoltage does not arise. Even if, therefore, the writing pulse PW of a high-voltage level is impressed, the sufficient erasing by the next erasing pulse is executed and the generation of the after-image is obviated. The generation of the defective light emission is, therefore, prevented while the large voltage margin is taken.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for driving a plasma display panel, and more particularly to a method for driving an XY matrix type AC plasma display panel (hereinafter abbreviated as FDP). .

[Conventional technology]

FIG. 3 shows an outline of a display device using an AC type FDP.

This device is broadly divided into a display drive unit 1 and a display control unit 2 that controls the display drive unit 1.

When the address data control signal is input to the ink face circuit 3 of the display control unit 2, it is applied to the Y drive circuit 5 of the display drive unit 1 via the display address buffer 4. The Y drive circuit 5 drives a plurality of FDPs 7 (for example,
400 Y electrodes 8 are driven. FDP7 is X, Y[
A well-known AC in which a discharge gas is sealed between opposing substrates (glass) equipped with poles, each substrate has X and Y electrode layers and a dielectric layer laminated, and a light-emitting display is performed using wall charges. It is a type FDP. On the other hand, in response to the address data control signal input to the ink face circuit 3, the display control circuit 9 of the display control unit 2 causes the display drive pulse generator 10 to apply a display drive pulse to the X drive circuit 11 of the display drive unit 1. The X drive circuit 11 drives a plurality of (for example, 600) Xfs of FDPs 7 designated via the X matrix circuit 12.
! ! Pole 13 Pole side 3. In this way, Y electrode 8 and
By selectively driving the a-pole 13, the corresponding Y
The discharge cells 14 located at the intersections of the electrodes 8 and the X electrodes 13 discharge and emit plasma, and each selected discharge cell 14
By emitting light, images such as various characters and figures are formed.

The total number of discharge cells on the FDP7 is 400 in the above example.
(Y) x 600 (X) Dots. Note that the Y drive circuit 5, the Y matrix circuit 6, and the X drive circuit 11
The reason why each of the X matrix circuits 12 is divided into two is to make it easier to take out the terminals since the electrode spacing becomes narrow when the number of each X-Y electrode is m x n trees. .

As shown in FIG. 4, the voltage for driving the FDP 7 is a pulse (hereinafter referred to as a write pulse) P for writing display data into each discharge cell 14 of the FDP 7.
v, and a pulse (hereinafter referred to as a sustain pulse) P for maintaining the written display data (that is, maintaining the discharge).
s and a pulse (hereinafter referred to as an erase pulse) for erasing (that is, stopping the discharge) the display data written once.

)Pp, is used.

There are various methods for writing, maintaining, and erasing display data, but they can be roughly divided into two methods: one in which each discharge cell 14 is individually selected and discharged; After all cells are discharged, erase pulse P
There is a method of selectively erasing the discharge cells 14 using E. The explanation here relates to the latter line sequential driving method. According to the line sequential driving method, after all the discharge cells 14 on the selected Y electrode emit light, unnecessary discharge cells 14 are selectively erased, and a desired image is formed with the remaining discharge cells 14. The Rukoto. This is the fourth
This will be explained in further detail using figures.

FIG. 4 is a diagram showing the correspondence between drive pulses and light emission according to the conventional line sequential drive method. First, in TA when a certain X electrode 13 is not selected (erasing operation); in one horizontal period (IH) of the FDP 7, a write pulse Pw is applied to the corresponding Y electrode, and an erase pulse is applied to the same Y electrode at the next timing. Pb is applied, and then a sustain pulse Ps is applied to all Y electrodes. As a result, the corresponding X electrode 13
emits light like LA in response to write pulse Pv and erase pulse PE, but thereafter does not emit light until the next write pulse Pw is applied.

On the other hand, when the X electrode 13 is selected (writing operation) T
In B, during the IH period of FDP7, the write pulse Py is similarly applied to a certain Y7m pole, but the erase pulse PC is not applied at the next timing, and the sustain pulse Ps is applied to all Y electrodes. As a result, the corresponding X electrode 13 continues to emit light like LB until the next write pulse Pv and erase pulse PE are applied thereafter. In other words, it exhibits a memory function.

The above operations are performed for each Y electrode in synchronization with the IH synchronization signal V11, and 1
2 screens are formed.

In this way, according to the conventional driving method, a write pulse Pw is first applied to one Y electrode to cause all discharge cells on the Y electrode to emit light, and then, if necessary, an erase pulse is applied to the same Y electrode. Either the PE is applied to erase the selected discharge cell, or the sustain pulse Ps is applied to drive only the selected discharge cell to maintain light emission.
Therefore, increasing the number of sustain pulses Ps makes it possible to proportionally emit high-intensity light. In other words, by adjusting the sustain pulse Ps,
As shown in FIG. 5, the luminance B of the selected discharge cell is varied from a high value B to a low value B'
I+ can be arbitrarily adjusted and is therefore given by the relative brightness difference between the light emission brightness Bit of the selected discharge cell and the non-light emission brightness Bt of the non-selected (erased) discharge cell.

The above is the general operation of an AC type FDP.

Next, details of the conventional driving method will be explained with reference to FIGS. 6 and 7.

As shown in FIG. 6, the Y electrodes Y1. Y
2, the X electrodes are respectively X1 and X2, and the Y electrodes at each intersection are discharge cells A and B.

Let them be C and D. In FIG. 6, it is assumed that X"TX k being “lit”,
Discharge cell B is half-selected and "not lit."

It is assumed that the discharge cell C is half-selected and is in a "non-lit" state, and the discharge cell C is not selected and is in a "non-lit" state.

FIG. 7 shows a drive pulse waveform for achieving such a lighting state. That is, in the discharge cell A, as shown in FIG. 7(a), the erase pulse PE is canceled by the cancel pulse Pc, and the write pulse Pw and the sustain pulse P
Since s is applied, it lights up. Since the erase pulse PE is applied to the discharge cell B, it is not lit even if the write pulse P1 and the sustain pulse Ps are applied. The discharge cell C is applied with the cancel pulse P1 and the sustain pulse Ps, but is not lit because there is no write pulse Pw. The discharge cell D is not lit only by the sustain pulse Ps.

[Problem to be solved by the invention]

A problem with the above conventional driving method is that since the write pulse Pw at the time of selection is a high voltage of about 150 V, sufficient erasing may not be possible even when the erasing pulse PE is applied next.

That is, FIG. 8 shows the drive waveform (a) and discharge current waveform (b) of half selection (non-lighting) of FIG. 7(b).

As shown in FIG. 8(a), after the write pulse Pw is applied, the erase pulse PE is applied, but the write pulse Pv suddenly rises from 0 level to 150.
Since a high voltage of V is applied to emit light, the discharge current ly between the Y electrode Y and the -X electrode X2 is large when the write pulse Pv is applied, and a large amount of wall charge is accumulated.

If the amount of this wall charge is large, the wall charge will not be erased by the next erase pulse PE and will remain, resulting in a current l due to the superposition of this wall charge and the charge caused by the voltage of the erase pulse PIE.
It happens that light is emitted by x. One possible means to prevent this is to lower the voltage of the write pulse Pw, but a drop in the write pulse Pw will adversely affect high-brightness display and reduce the drive voltage margin.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a driving method that does not cause unerased portions while ensuring a large voltage margin.

[Means to solve the problem]

In order to solve the above problems, the present invention provides each Y electrode (Y,
By applying a write pulse (P, ) for each Y2), all discharge cells (A, B, C, D) on the Y electrode are made to emit light, and then selected as one of the X electrodes (X, X2). An X-Y matrix type AC plasma display device that forms an image by stopping the light emission of any of the discharge cells (A, B, C, D) by applying an erase pulse (PE). In a spray panel driving method, when adjusting brightness, a sustain pulse (P ss) having the same polarity as the write pulse is selectively applied to the Y electrode to be written, prior to applying a write pulse (P,). Configure.

[Effect]

According to the present invention, the sustain pulse (P ss) is applied prior to the application of the write pulse (Pw).
Since the voltage is applied with the same polarity as w ), a large potential difference does not occur in the gap between the electrodes. Therefore, a wall charge acting in the opposite direction is generated, and the discharge reaches the normal sustain pulse Ps level, which can be sufficiently erased by the erase pulse (PR).

[Total implementation]

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of the present invention. In this Figure 1,
The same reference numerals are given to the parts that overlap with those in FIG. 7, and the explanation will be given below.

As shown in FIG. 1, a drive waveform pulse is generated so as to apply a sustain pulse Pss of the same polarity in succession to the write pulse Pw prior to the application timing of the write pulse Pv.

The waveform of FIG. 1(b) is shown in FIG. 2(a), and the corresponding discharge current waveform is shown in FIG. 2(b).

In this way, by applying the sustain pulse Pss prior to the write pulse Pw, as in the conventional case (see FIG.
b), iV) Since the discharge current does not increase and the voltage applied to the x-y@electrode gap does not increase, wall charges are not accumulated excessively. Therefore, even if a write pulse Pw at a high voltage level is applied, it can be sufficiently erased by the next erase pulse PE, and no afterimage will occur.

In this way, it is possible to prevent the occurrence of defective light emission while maintaining a large voltage margin.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to suppress defective light emission due to application of a high level write pulse, and a large voltage margin can be secured, so that high brightness light emission is not impaired.

Xl, X2...X electrode Yt, Y2...Y electrode Pv...Writing pulse Ps...sustaining pulse PE...Erasing pulse PC...Cancel pulse Pss...sustaining pulse A, B, C, D...discharge cell

[Brief explanation of drawings]

Fig. 1 is a drive waveform diagram of an embodiment of the present invention, Fig. 2 is a detailed drive waveform diagram of an embodiment of the invention, and Fig. 3 is a conventional AC type F
A schematic diagram of a DP display device, Fig. 4 is a drive waveform diagram of a conventional driving method, Fig. 5 is an explanatory diagram of a conventional brightness adjustment method, Fig. 6 is an explanatory diagram of a discharge cell, and Fig. 7 is a diagram of conventional driving. The waveform diagram in FIG. 8 is an explanatory diagram of the problems of the conventional driving method.

Claims (1)

[Claims] For each Y electrode (Y_1, Y_2), write pulse (P_
By applying W), all the discharge cells (A, B, C, D) on the Y electrode are made to emit light, and then the X electrode (X_1
, X_2).
By applying , any of the above discharge cells (A,
In a method of driving an X-Y matrix type AC plasma display panel in which an image is formed by stopping the light emission of B, C, D), a write pulse (P
A method for driving a plasma display panel, comprising selectively applying a sustain pulse (P_S_S) having the same polarity as the write pulse prior to application of the write pulse (P_S_S).