CN100594530C - A plasma display panel driving method and plasma display panel apparatus - Google Patents

Abstract

Set-up, write, sustain and erase pulses are variously applied to a plasma display panel using a staircase waveform in which the rising or falling portion is in at least two steps. These staircase waveforms can be realized by adding at least two pulses. Use of such waveforms for the set-up, write and erase pulses improves contrast, and use for the sustain pulses reduces screen flicker and improvesluminous efficiency. This is of particular use in driving high definition plasma display panels to achieve high image quality and high luminance.

Description

Plasma displaying-board driving method and gas ions display panel apparatus

The application be that July 19, application number in 1999 are 200410045721 the applying date, denomination of invention divides an application for the application of " plasma displaying-board driving method and gas ions display panel apparatus ".

Technical field

The present invention relates to plasma display panel display device and plasma displaying-board driving method, particularly use the driving method that writes display separation (below be called ADS) method as the display screen of computing machine, TV etc.

Background technology

Recently, plasma display panel (below be called PDP) can be realized the large tracts of land, the thin and light display device that are used in computing machine, the TV etc. because of it becomes the focus of being paid close attention to.

PDP can be divided into two classes generally: direct current and AC type.EP 0762461 discloses the example of a kind of direct current PDP, and the discharge cell of this PDP exchanges PDP and is suitable for use as on the giant-screen, therefore the type for now mainly using by arranged.

Introduced its resolution now up to the high definition television of 1920 * 1080 pixels, and PDP preferably equally with other types of display to plant high-resolution display therewith compatible mutually.

Fig. 1 is the synoptic diagram of conventional AC PDP.

In this kind PDP, liner plate 11 and rear lining plate 12 before placing are abreast practised physiognomy each other and are placed over the ground and the space is arranged therebetween, and the edge with lining seals subsequently.

Being parallel strip ground on the inside surface of preceding lining 11 forms scan electrode group 19a and keeps electrode group 19b.Use dielectric layer 17 coated electrode group 19a and the 19b that constitute by lead glass etc.Use manganese oxide (MgO) protective seam 18 to cover on the surface of dielectric layer 17 afterwards.The data electrode group 14 that forms with parallel strip that is covered by insulation courses such as lead glass 13 places on the inside surface of rear lining plate 12.On the top of insulation course 13, place a plurality of barrier ribs 15 abreast with data electrode group 14.The space that liner plate is 11,12 is divided into the space of 100-200 micron by barrier ribs 15.Envelope has discharge gas in these spaces.Envelope has the pressure at discharge gas place to be located at usually under external world's (atmosphere) air pressure, typically between the 200-500 torr.

Fig. 2 illustrates the PDP electrode matrix.Electrode group 19a and 19b and data electrode group 14 are at right angles settled.The electrode crossing place forms the discharge cell between liner plate.Barrier ribs 15 separately in case the discharge between adjacent discharge cell is spread, can obtain high resolving power with adjacent discharge cell like this.

In monochromatic PDP, mainly the mixed gas of being made up of neon is used as discharge gas, sends visible light when discharge.But in the color PDP of Fig. 1, the fluorescence coating 16 that is made of fluorophor red, green, blue three primary colours forms on the inwall of discharge cell, and the mixed gas (as neon/xenon or helium/xenon) that mainly is made of xenon is used as discharge gas.The ultraviolet light that will be produced by discharging with fluorescence coating 16 converts visible light of all kinds to and carries out colored visualization.

Discharge cell in this PDP only has two show states, Kai Heguan basically.One frame (one) is divided into the ADS method of a plurality of subframes (son) and combines with the representing gradation level with open and closed in each subframe.

Fig. 3 is illustrated in when expressing 256 gray levels the dividing method to a frame.The transverse axis express time, and dash area represent the discharge keep the phase.

In the example segmentations method of Fig. 3, a frame is divided into 8 subframes.The ratio that the phase is kept in the discharge of subframe is made as 1,2,4,8,16,32,64 and 128 respectively.These 8 binary combination have been expressed 256 kinds of gray levels.TSC-system TV regulation frame rate was 60 frame/seconds, and therefore the time of a frame is decided to be 16.7ms.

Each subframe is made of following: initialization phase, one are write the phase, phase and an erasing period are kept in a discharge.

Fig. 4 is a sequential chart, is illustrated in the correlation technique when pulse is added on the electrode in a subframe.

In the initialization phase, go up and initialization discharge cell by initialization pulse being added to all scan electrode 19a.

Writing the phase, data pulse is added on the selected data electrode 14 and scanning impulse is added on the scan electrode 19a subsequently.This makes, and electric charge is accumulated in the cell to be lighted on the wall, writes out a pixel data screen.

Keep the phase in discharge, at scan electrode 19a with keep and add a big pulse voltage between electrode 19b, make the discharge cell of the wall electric charge that wherein added up discharge occur, and send light in certain period.

At erasing period, on scan electrode 19a, add burst pulse in a large number, the wall electric charge in the discharge cell is wiped free of.

In above-mentioned driving method, under the normal condition light only should keep interim sending in discharge and should be in initialization, write with erasing period and have light to emit.But when being added with initialization or erasing pulse, discharge can make entire display panel luminous, and thereby contrast is reduced.The discharge that occurs when adding write pulse also makes the discharge cell luminous, damages contrast.Therefore, need a kind of method that addresses these problems.

It is long as much as possible that above-mentioned PDP driving method also should make the discharge in every frame keep the phase, to improve brightness.Therefore, write pulse (scanning impulse and data pulse) preferably should be short as far as possible, can write at high speed like this.

High-resolution PDP has a large amount of scan electrodes, therefore need make write pulse (scanning impulse and data pulse) narrow, thereby can drive at a high speed.

But in traditional PD P, set write pulse narrowlyer and can produce the defective of writing, the image quality of demonstration is reduced.

If the voltage height and the pulse of write pulse are narrow, but just zero defect ground is write reliably with high speed.Therefore but normally, the ability that the high-speed data driver is withstand voltage is lower, is difficult to obtain the driving circuit that can high-voltage high-speed writes.

In above-mentioned PDP driving method, another emphasis is to drive PDP with low-power consumption.For reaching this point, the ineffective power consumption of the phase of keeping that should reduce to discharge is to increase luminance efficiency.

The object of the present invention is to provide a kind of PDP driving method, but its high speed operation, and improve contrast not causing under the situation of writing defective.Another object of the present invention is to provide a kind of PDP driving method that improves luminescence efficiency.A further object of the present invention provides a kind of PDP driving method, produces high image quality and high brightness under the situation that does not cause flicker and burr.

In the present invention, the waveform with two rank or multistage rising ladder is used as initialization pulse.Can improve contrast as initialization pulse and not produce with this kind waveform without simple rectangular pulses and write defective.

Make write pulse without simple rectangular pulses with two rank or multistage decline staircase waveform, can realize high-speed driving and do not cause the defective of writing.

Simultaneously, making write pulse with two rank or multistage rising staircase waveform can improve contrast and can not cause and write defective.

In addition, simple square wave and keep pulse with two rank or multistage decline staircase waveform and can allow to set with high pressure and keep pulse is stably worked guaranteeing, thereby is obtained high-quality picture.

If simple square wave and keep pulse with two rank or multistage rising staircase waveform and can improve luminescence efficiency.When first rank of second rank of the rising part of waveform and sloping portion and continuous function at once, then can obtain the raising of tangible luminescence efficiency.

By the rising part that uses its waveform is that oblique waveform is kept pulse, also can improve luminescence efficiency.

The method that another kind improves luminescence efficiency is to use a kind of waveform, wherein is higher than the added voltage that occurs the zero hour in the pulse of keeping pulse at the maximum voltage constantly of discharge current.

Doing discharge with two rank or multistage staircase waveform keeps the phase added first and keeps pulse and can improve image quality.

In addition, simply square waveform and do erasing pulse with two rank or multistage rising staircase waveform and can improve contrast obtains high image quality.

Use two rank or multistage decline staircase waveform to do erasing pulse and can shorten erasing period.

By simultaneously to initialization, write, keep with erasing pulse and use staircase waveform can further improve these effects.

Resemble and be used in initialization, write, keep with erasing pulse on the staircase waveform to rise on two rank or to descend can come together to obtain by two or more pulses are added in.

Description of drawings

Fig. 1 is the profile diagram of conventional AC PDP;

Fig. 2 illustrates the electrode matrix of above-mentioned PDP;

Fig. 3 is illustrated in the frame dividing method when driving above-mentioned PDP;

Fig. 4 is the related example of the sequential chart when being added to pulse on the electrode in a frame;

Fig. 5 illustrates the block scheme of PDP driving device structure related to the present invention;

Fig. 6 illustrates the scanner driver structured flowchart of Fig. 5;

Fig. 7 illustrates the data driver structured flowchart of Fig. 5;

Fig. 8 illustrates the sequential chart of the PDP driving method relevant with first embodiment;

Fig. 9 is the block scheme of the impulse summation circuit relevant with embodiment;

Situation when Figure 10 illustrates and by the impulse summation circuit first and second impulse summations risen staircase waveform to form on two rank;

Figure 11 illustrates the result of experiment 1;

Figure 12 is a sequential chart, and the PDP driving method relevant with second embodiment is shown;

Figure 13 illustrates with the impulse summation circuit the situation of first and second impulse summations when being formed with the waveform of two rank decline ladders;

Figure 14 illustrates the result of experiment 2;

Figure 15 is a sequential chart, and the PDP driving method relevant with the 3rd embodiment is shown;

Figure 16 is the block scheme of the ladder wave generation circuit relevant with the 3rd embodiment;

Figure 17 illustrates the measurement result of experiment 3;

Figure 18 is a sequential chart, and the PDP driving method relevant with the 4th embodiment is shown;

Figure 19 is the measurement result of experiment 4A;

Figure 20 is a sequential chart, and the PDP driving method relevant with the 5th embodiment is shown;

Figure 21 illustrates the measurement result of experiment 5A;

Figure 22 is a sequential chart, and the PDP driving method relevant with the 6th embodiment is shown;

Figure 23 and 24 illustrates the measurement result of experiment 6;

Figure 25 is a sequential chart, and the PDP driving method relevant with the 7th embodiment is shown;

Figure 26 illustrates with the impulse summation circuit first and second impulse summations to produce on two rank situation of the staircase waveform that rises and descend;

Figure 27 is a sequential chart, illustrates with simple square wave as keeping the V-Q Lissajous figure that is produced when pulse drives;

The example of the V-Q Lissajous figure that Figure 28 is seen when driving PDP for the method with the 7th embodiment;

Figure 29 is a sequential chart, and the PDP driving circuit relevant with the 8th embodiment is shown;

Figure 30 illustrates the waveform of keeping pulse among the 8th embodiment;

Figure 31 illustrates with the impulse summation circuit the situation of first and second impulse summations with the staircase waveform that forms the 8th embodiment;

Figure 32 illustrates the measurement result of experiment 8A;

Figure 33 is the example of V-Q Lissajous figure, and the measurement result of experiment 8A is shown;

Figure 34 is a sequential chart, and the PDP driving method relevant with the 9th embodiment is shown;

Figure 35 is a block scheme, and the trapezoidal waveform generation circuit relevant with the 9th embodiment is shown;

Figure 36 illustrates the trapezoidal waveform that is produced by trapezoidal waveform generation circuit;

Figure 37 illustrates the measurement result of experiment 9A;

Figure 38 is the example of V-Q Lissajous figure, and the measurement result of experiment 9A is shown;

Figure 39 is a sequential chart, and the PDP driving method relevant with the tenth embodiment is shown;

Figure 40 illustrates the measurement result of experiment 10A;

Figure 41 is a sequential chart, and the PDP driving method relevant with the 11 embodiment is shown;

Figure 42 illustrates the measurement result of experiment 11;

Figure 43 is a sequential chart, and the PDP driving method relevant with the 12 embodiment is shown;

Figure 44 is a sequential chart, and the PDP driving method relevant with the 13 embodiment is shown;

Figure 45 illustrates the figure as a result of experiment 13A;

Figure 46 is a sequential chart, and the PDP driving method relevant with the 14 embodiment is shown;

Figure 47 is a sequential chart, and the PDP driving method relevant with the 15 embodiment is shown;

Embodiment

Below with reference to accompanying drawing embodiments of the invention are described.

PDP 10 used in each embodiment has identical physical arrangement with the PDP that explains with reference to figure 1 in prior art, therefore use the label identical with Fig. 1.

The driving method of embodiment use substantially with applied correlation technique part in the ADS method explained.But respectively in initialization, to scan, keep with the added initialization of erasing period, scan, keep with erasing pulse be not to be simple square wave, but be staircase waveform or be ramp waveform.

Used drive unit and driving method among the explained later embodiment.

Fig. 5 is a block scheme, and the structure of drive unit 100 is shown.

Drive unit 100 comprises pretreater 101, frame memory 102, synchronizing pulse generating unit 103, scanner driver 104, keeps driver 105 and data driver 106.Pretreater 101 is handled from the pictorial data of outer image autput device input.Data after frame memory 102 stores processor.Synchronizing pulse generating unit 103 is that every frame and each subframe produce synchronizing pulse.Scanner driver 104 is added to pulse on the scan electrode 19a, keep driver 105 and pulse is added to keeps on the electrode 19b, and data driver is added to pulse on the data electrode 14.

Pretreater 101 extracts the pictorial data of every frame from input image data, produce the pictorial data of each subframe from the pictorial data of being extracted (subframe pattern image data), and it is stored in the frame memory 102.Pretreater 101 outputs to the current subframe pattern image data of being deposited in the frame memory 102 on the data driver 106 subsequently line by line, from the pictorial data of input, detect synchronizing signal, and the synchronizing signal of every frame and subframe is sent on the synchronizing pulse generating unit 103 such as horizontal-drive signal and vertical synchronizing signal.

Frame memory 102 can be stored the data of the every frame that is divided into the subframe pattern image data of each subframe.

Specifically, frame memory 102 is two mouthfuls of frame memories, has two memory blocks, and each district can store a frame (eight sub-frame images).When being read, the frame memory district alternately on the memory block, writes frame data.

Synchronizing pulse generation circuit 103 produces trigger pip, indicates each initialization, scans, keeps the moment of rising with erasing pulse.These trigger pips produce from the synchronizing signal that pretreater 101 receives with reference to every frame and each subframe place, and send on the driver 104-106.

Scanner driver 104 produces according to the trigger pip that receives from synchronizing pulse generating unit 103 and applies initialization, scans, keeps and erasing pulse.

Fig. 6 is a block scheme, and the structure of scanner driver 104 is shown.

Initialization, keep with erasing pulse and be added on all scan electrode 19a.Required pulse waveform is different according to situation.

As a result, scanner driver 104 has three pulse producers, and as shown in Figure 6, each generator produces a kind of pulse.These generators are initialization pulse generators 111, keep pulse producer 112a and erasing pulse generator 113.Three pulse producers are connected in the floating ground mode, and according to the trigger pip of unit 103 successively with initialization, keep with erasing pulse and be added to scan electrode group 19a.

As shown in Figure 6, scanner driver 104 also comprises a traffic pilot 115 and the scan pulse generator 114 that is attached thereto, and it makes scanning impulse sequentially be added to scan electrode 19a ₁, 19a ₂... 19a _NEmploying produces pulse and is switched and the method for output by traffic pilot 115 in scan pulse generator 114, but also can be adopted as the structure that each scan electrode 19a provides independent scanning impulse generation circuit.

Switch SW ₁And SW ₂Be placed in the scanner driver 104, selectively the output of above-mentioned pulse producer 111-113 and the output of scan pulse generator 114 are added to scan electrode group 19a.

Keep driver 105 and have one and keep pulse producer 112b, and produce according to trigger pip and to keep pulse, and this is kept pulse be added to and keep electrode 19b from synchronizing pulse generating unit 103.

Data driver 106 outputs to data electrode 14 in parallel with data pulse ₁-14 _MOn.Export according to the sub-field information that once serial is input to data driver 106 in delegation.

Fig. 7 is the block scheme of data driver 106 structures.

Data driver 106 comprise the sub-frame data of once getting a scan line first latch cicuit 121, the described scan line of storage sub-frame data second latch cicuit 122, produce the data pulse generator 123 of data pulse and at each electrode 14 ₁-14 _MThe AND gate 124 of porch ₁-124 _M

In first latch cicuit 121, sub-frame data and the clock CLK signal Synchronization of sending from pretreater 101 also once sequentially got many positions in order.(show data electrode 14 separately in case latched the subframe pattern image data of one scan row ₁-14 _MWhether apply pulse), just send second latch cicuit 122 to.The AND gate 124 that second latch cicuit 122 will belong to the data electrode that is added with pulse according to the trigger pip from synchronizing pulse generating unit 122 ₁-124 _MOpen.Meanwhile, data pulse generator 123 produces data pulse, and this data pulse is along with opening of AND gate is added on the data electrode.

In drive unit 100, as below will explaining, in order to show a frame image, be with initialization, the operation of keeping a subframe that constitutes with erasing period that writes, discharges repeats eight times.

In the initialization phase, the switch SW in the scanner driver 104 ₁And SW ₂Be respectively Kai Heguan.Initialization pulse generator 111 is added to an initialization pulse on all scan electrode 12a, makes in all discharge cells the initialization discharge to occur, and the wall electric charge that in each discharge cell, adds up.A certain amount of wall voltage is added in each cell, then discharges beginning just soon subsequent interim the writing that write.

Writing the phase, the switch SW in the scanner driver 104 ₁And SW ₂Be respectively Guan Hekai.The negative scanning impulse that is produced by scan pulse generator 114 sequentially is added to last column N of first row 1 of scan electrode 19a to scan electrode 19a.Simultaneously, data driver 106 is by being added to positive data pulse and the corresponding data electrode 14 of discharge cell to be lighted ₁-14 _MAnd write discharge, the wall electric charge is accumulated in these discharge cells.Therefore, the sub-image of a picture is to write up by accumulation wall electric charge on the dielectric layer surface in discharge cell to be lighted.

Scanning impulse and data pulse (in other words for writing pulse) should be established narrowly as much as possible to carry out driving at a high speed.If but it is too narrow to write pulse, just has and similarly write defective.In addition, be subjected to the restriction of used circuit types, mean that pulse width need be located at about 1.25 μ m or bigger usually.

In the phase of keeping, the switch SW in the scanner driver 104 ₁And SW ₂Be respectively Kai Heguan.Keeping pulse producer 112a is added to whole scan electrode group 12a with the discharge pulse of regular length (for example 1-5 μ s) and keeps driver 105 and the discharge pulse of regular length is added to the whole operation of keeping electrode group 12b alternately carries out.

This operation is raised to the discharge inception voltage (to call starting potential in the following text) that is higher than wherein in having added up the discharge cell of wall electric charge in the phase of writing with the current potential on dielectric layer surface, thereby occurs discharge in these cells.This keeps to discharge to make in the discharge cell and sends ultraviolet light.Fluorophor in this ultraviolet excitation fluorescence coating is to send the colored corresponding visible light of fluorescence coating with each discharge cell.

At erasing period, the switch SW in the scanner driver 104 ₁And SW ₂Be respectively Kai Heguan.Narrow erasing pulse is added on the whole scan electrode group 19a, will be by producing incomplete discharge in each cell mesospore charge erasure of discharging.

Below each embodiment of 15 embodiment explained that all specific pulse waveform arranges and effect.

First embodiment

Fig. 8 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

In correlation technique driving method shown in Figure 4, initialization pulse is simple rectangle.But what in this embodiment, initialization pulse adopted is that the staircase waveform that rises on two rank is arranged.

By two kinds of pulse waveform additions are obtained this kind waveform.

Fig. 9 is a block scheme, and the impulse summation circuit that produces staircase waveform is shown.

The impulse summation circuit comprises first pulse producer 131, second pulse producer 132 and delay circuit 133.First and second pulse producers 131 and 132 usefulness floating ground modes are in series, and the output voltage of two generators is superimposed.

Figure 10 A illustrates the impulse summation circuit, and first and second impulsive synchronization are to be formed with the staircase waveform that rises on two rank.

First pulse that is produced by first pulse producer 131 is wide square wave, and second pulse that second pulse producer 132 produces is narrow square wave.

Second pulse that first pulse that generator 131 produces and generator 132 produce is by 133 one schedule times of time-delay of delay circuit.These pulses produce from add pulse generating unit 103 according to trigger pip.Set the width of each pulse, so almost begin to descend in synchronization first and second pulses.

With first and second impulse summations, rise like this so that have on two rank in the output pulse.

As a kind of variation of impulse summation circuit shown in Figure 9, first and second pulse producer 131 and 132 can in parallel and first and second pulses output stack.Shown in Figure 10 B, having the step pulse that rises on two rank can produce by making second pulse producer 132 produce second pulse that is higher than first pulse.

Initialization pulse generator 111 among this embodiment has a sort circuit and with having the staircase waveform that rises on two rank as initialization pulse.

As below explaining, simple square wave and suppressed to write defective and improved contrast as initialization pulse with this waveform.

In other words, initialization pulse is added on the discharge cell so that a certain amount of wall electric charge is accumulated in each discharge cell, said process is being target writing aspire to the formation condition that accurately writes in short-term.

Should be not luminous when adding initialization pulse.If resembling in the prior art with simple square wave as initialization pulse, when voltage raises, have big change in voltage (change in voltage scope), and produce strong discharge trend.This discharge can cause sending high light from whole screen, and therefore contrast descends.In addition, the generation (undesired discharging) of the strong discharge of this kind more likely makes the wall electric charge change that has added up in each discharge cell after having applied initialization pulse.This change can cause the part to write the change of defective and brightness.

If make initialization pulse, just can avoid the sudden change in this voltage and institute's making alive is raise with two rank rising waveform.Thereby stably add up the wall electric charge and can not produce undesirable light discharge.

This reason is, when initialization pulse raises voltage change scope and the brightness that occurred between be not proportional relation.Although the little change in the voltage can not cause excessive brightness and produce, will see that when change in voltage reaches certain value brightness increases significantly.Therefore, make voltage arrive certain value with two rank rather than one-level and can reduce brightness by discharge generation.

Stably add up wall electric charge and limit brightness of also available oblique rising waveform of in United States Patent (USP) 5745086, instructing such as Weber.But the rise time among the Weber is extremely long.Can replace stably carrying out initialized method with two rank rising waveform of the present invention with burst pulse.

By using two rank rising waveform, can stably carry out initialization in that short initialization is interim, it can more speed be driven.

The PDP driving method of present embodiment can the high-speed driving display board and do not write defective, and improves contrast to obtain the high-quality picture.

If be used to be raised to the voltage V of the first step ₁With crest voltage V _StCompare too for a short time, then when being raised to second rank, will have a large amount of light and penetrate, and have and make the contrast that has been improved that loss be arranged.Therefore, voltage V ₁With V _StRatio should be located at 0.3-0.4 or bigger, and (V _St-V ₁) and V _StRatio should be located at 0.6-0.7 or littler.

If rise on first rank and compare the period (i.e. the flat of the first rank tp) that rises on terminal and second rank between beginning too widely with pulsewidth tw, it will have bad effect.Therefore, the ratio of tp and tw should be located at 0.8-0.9 or still less.

Up voltage V on first rank ₁Preferably should be located at V _f-70V≤V ₁≤ V _fV _fIt is the starting potential of drive unit.

Starting potential V _fBe by the determined fixed value of the structure of PDP10.And by measuring at scan electrode 12a and keeping between electrode 12b the voltage that increases very lentamente and read out in the discharge cell when beginning to light added voltage and determine.

Experiment 1

When driving PDP, be used as initialization pulse with two rank rising waveform.When driving, crest voltage V _StKeep fixingly with pulsewidth tw, but change ratio and the (V of tp and tw _St-V ₁) and V _StThe value of ratio and the variation of surveying its contrast and brightness value.

The waveform of each initialization pulse all is to be produced by given waveform generator, and this output voltage was amplified by the high speed and high pressure amplifier before being added to PDP.

Produce the brightness ratio that white is also measured secretly and highlights divides by a part of in the darkroom, lighting PDP and measure contrast.

Figure 11 illustrates this result of experiment, has expressed ratio and the (V of tp and tw _St-V ₁) and V ₁Ratio and the relation of contrast.

Shadow region in the accompanying drawing is the high place of contrast, and very little by the change that writes the brightness that defective causes, and in other words, this district is acceptable zone.The unacceptable result of region representation outside the shadow region.

As seen from the figure, tp preferably should be within the 0.8-0.9 (V with the ratio of tw _St-V ₁) and V _StRatio preferably should be within the 0.6-0.7.If but tp/tw and (V _St-V ₁)/V _StToo little, just can not obtain any result, like this, preferably make its ratio be located at 0.05 or bigger.

Present embodiment adopt with two impulse summations with form rise ladder on two rank waveform as initialization pulse.But also can be by three or more impulse summation is reached same excellent picture effect with the multistage waveform that generation has upgrading on three or more.

Second embodiment

Figure 12 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

In first embodiment, with two rank rising waveform as initialization pulse, but in this embodiment, with two rank falling waveform as initialization pulse.

Figure 13 illustrate the impulse summation circuit with first and second impulse summations to be formed with two rank decline staircase waveforms.

Two rank falling waveform are utilized the second pulsion phase Calais generation that also produces by first pulse and second pulse producer 132 with 131 generations of first pulse producer as the impulse summation circuit among first embodiment.

Specifically, use the impulse summation circuit as Fig. 9, wherein first pulse producer and second pulse producer are in series with the floating ground mode.When as shown in FIG. 13A, first pulse producer 131 almost rises second pulse of narrow square wave with second pulse producer 132 first pulse of wide square wave is risen.By two impulse summations are produced one two rank falling waveform.Another program is to be impulse summation circuit in parallel with first and second pulse producers wherein.Shown in Figure 13 B, in the case, first pulse producer makes first pulse of narrow square wave rise to higher level, and second pulse producer makes square wave rise to lower level.These two impulse summations produce one two rank falling waveform.

If but in prior art, as initialization pulse, when voltage drop was big, the sudden change of voltage (change in voltage scope) will cause from erasure discharge so with simple square wave.Should make high light luminous from the whole screen from erasure discharge, reduce contrast.

Because a part of wall electric charge that forms in the rising stage of initialization pulse is wiped electric charge certainly and eliminated, its basis (priming) effect is also weakened.

If as initialization pulse, the voltage jump of experience will no longer occur when electric charge descends, and like this, just be restricted from erasure discharge with two rank falling waveform.As a result, can limit light, the improvement contrast sent from whole screen, the elimination of wall electric charge is restricted, basic effect is improved.

If will gradually fall waveform as initialization pulse, the wall electric charge that can stably add up is also controlled brightness in a similar manner, but the fall time of waveform is longer.But in the present embodiment, use two rank falling waveform that the initialization that utilizes burst pulse to carry out is stably carried out.

Therefore, use two rank falling waveform in the short initialization phase, to carry out initialization, and can drive at a high speed.

The PDP driving method of present embodiment can carry out high-speed driving and not have writing defective, and contrast is significantly improved.The result can obtain the image of high-quality.

If in the first step, descend required voltage V ₁With respect to crest voltage V _StToo narrow, then in second step descended, will there be a large amount of light to penetrate, and have the danger that those effects are lost.Therefore, V ₁With V _StRatio should be located within the 0.8-0.9.

If the time between the end that first rank descend and the decline of second rank initial, (i.e. the width of the flat of the first rank tp) is with respect to pulsewidth t _nToo big, then have ill effect.Therefore, tp should be located within the 0.6-0.8 with the ratio of tw.

Experiment 2

Use various initialization pulses to drive PDP, and measure contrast in all cases with the same quadrat method in the experiment among first embodiment with two different rank falling waveform.

When driving PDP, each value is used for the ratio of tp that pulsewidth tw is compared with the width of first time depression of order tp and tw, and with maximum voltage V _StWith at the first rank drop-out voltage V ₁Ratio V ₁With V _StThe ratio.

Figure 14 shows this result of experiment, has represented ratio and the V of tp and tw ₁With V _StRatio with the relation between the contrast.

Shadow region among the figure is that contrast is higher and change very low zone by writing the brightness that defective produces, and in other words, is acceptable zone.Zone outside the shadow region is unacceptable result.

As seen from the figure, t _pWith t _wRatio and V ₁With V _StRatio should be too not big, like this, t _pWith t _wRatio preferably answer within 0.6 to 0.8 and V ₁With V _StRatio 0.8-0.9 within.If but tp and tw and V ₁With V _StRatio too little, then can't obtain useful results, therefore, its ratio preferably is located at 0.05 or bigger.

Present embodiment used two impulse summations with the waveform that forms two rank decline staircase waveforms as initialization pulse.But by three or more impulse summation also can be obtained same effect to produce the multistage waveform with depression of order under three or more that can realize than high picture quality.

The 3rd embodiment

Figure 15 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

In first embodiment, be used as initialization pulse with two rank rising waveform.But the also available multistage staircase waveform that three or more (for example 5 rank) raised bench is arranged of present embodiment.

By using the ladder wave generation circuit can obtain the multistage waveform initialization pulse of this kind as initialization pulse generator 111.

Figure 16 is the block scheme of ladder wave generation circuit, and sort circuit " has description in the electronic communication handbook what Denshi TsushinGakkai published.

The ladder wave generation circuit comprises and produces fixed number (in this example being 5) clock signal generator 141, electric capacity 142 and 143 and reset switch 144 of negative pulse (voltage Vp) continuously.The capacity C of capacitor 142 ₁Be set at the capacity C that is higher than capacitor 143 ₂

When clock signal generator 141 sent first pulse, the voltage of output unit 145 rose to C ₁/ (C ₁+ C ₂) V _pThe voltage of output unit 145 rises to C when sending second pulse ₁* C ₂/ (C ₁+ C ₂) ²V _pWhen sending the 3rd pulse, then rise to C ₁* C ₂/ (C ₁+ C ₂) ³V _p

Therefore, when clock signal generator 141 sends the pulse of fixed number (5), then export the waveform of the corresponding exponent number that risen.Subsequently, after the set time, produce initialization pulse waveform with a plurality of raised bench (5 rank) by reset switch 144.Output one side generation discharge at circuit descends voltage.

The effect of using the multistage rising waveform gained of this kind is identical with effect among first embodiment basically.Although but voltage is raised to same level, the voltage on each rank rises very little, can obtain better effect like this.

In this step pulse waveform, (slope of Figure 15 center line A a) preferably should be located at and is not less than 1V/ μ s but is not more than 9V/ μ s the mean value of voltage change ratio in each rank after first rank.Its reason is as follows:

If voltage raises, thereby the speed of change in voltage is positive region generating weak discharge in the I-V characteristic then within these ultimate values, and discharge occurs under the pattern of constant voltage almost, and therefore, retention value is V in the discharge cell _f ^*, compared with beginning voltage V _fLower slightly.This means and voltage V and V _f ^*Potential difference (PD) (V-V _f ^*) corresponding negative wall electric charge can be accumulated on the surface of the lip-deep dielectric layer of scan electrode 12a effectively.

If the mean value α of voltage change ratio is located at 10V/ μ s or bigger, then the light that is sent by the initialization pulse discharge obviously descends with regard to stronger and contrast.If but the α value in this scope, and if particularly be located at 6V/ μ s or more hour, the light ratio of being sent by the initialization pulse discharge is kept the light that discharge sends and is wanted much weak, and contrast is almost completely unaffected.

If being the mean value α value of voltage change ratio, initialization carries out for 10V/ μ s or when bigger, the accumulation of control wall electric charge difficulty under uniform rate then, thereby write defective easilier in the follow-up interim generation that writes.The light that excessive change in voltage then can make initialization pulse produce when initialized rising part increased is very strong and wall voltage is inhomogeneous.This is can produce strong discharge (from erasure discharge) because produce strong discharge during the pulse rising part and accumulate excessive wall electric charge between the rising stage in the sloping portion of pulse.

As in first embodiment explain the voltage V that rises on first rank ₁Should be with respect to starting potential V _fTo be set to V _f-70V≤V ₁≤ V _fBe advisable.

Experiment 3

Rise staircase waveform on 5 rank and drive PDP with having, and measure wall charge transfer quantity Δ Q[PC as initialization pulse] with write pulse voltage V _DataRelation between [V].In order to investigate thoroughly the dependence for the drive condition of rising stage voltage average rate of change α, setting first rank average voltage rate of change α [V/ μ s] afterwards is 2.1 and 10.5 various values, and measures.

Utilize given waveform generator to produce the initialization pulse of various waveforms, and its voltage was amplified before being added to PDP by the high speed and high pressure amplifier.Up voltage initialization pulse voltage is arranged on 180V on first rank, than discharge inception voltage V _fLow 20V.

Measure wall charge transfer quantity Δ Q by the wall charge detecting device being connected to PDP.This circuit is identical with the principle of the Sawyer-Tower circuit that characteristics such as assessing strong dielectric is used.

Figure 17 illustrates the result of this measurement, illustrates to write pulse voltage V at each value of each average voltage rate of change α _DataAnd the relation between the wall charge transfer quantity Δ Q.

If less than 3.5pc, then just easily producing to write defective and shield, dodges Δ Q.Therefore, for making PDP by driven, just should be with V _DataBe located on the line of the Δ Q=3.5pc shown in the figure.

As seen from the figure, voltage V _DataRising with the wall charge transfer quantity that writes discharge generation raises.This shows V _DataRising the discharge probability strengthened and reduced to write defective.

Among the figure, V _DataThe scope that occupies is less, and this shows that the transfer amount of wall electric charge is also bigger for bigger average voltage rate of change α.In other words, if average voltage rate of change α is located on the higher level in this scope, then can keep the level of wall charge transfer quantity Δ Q and even at V _DataStill can correctly drive PDP when being located at than low value.

In the driving method of present embodiment, can be limited in can not losing on the desired level contrast and can reduce at the wall electric charge of whole initialization phase and write discharge defect.As a result, can make because of flicker and the coarse image quality deterioration that causes of particle and be improved and obtain the high-quality picture.

Make initialization pulse with multistage rising waveform in the present embodiment, but the staircase waveform of also available multistage rising or decline is made initialization pulse, to obtain same high-quality image quality.

The 4th embodiment

Figure 18 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

Present embodiment adopts the staircase waveform with the decline of two rank as data pulse.

In data pulse generator 123, can adopt the sort of impulse summation circuit of being explained among second embodiment, so that two rank decline staircase waveforms are used as data pulse.

If adopt with correlation technique in similar simple square wave, data pulse widths is located at and is not more than 2 μ s the discharging efficiency of keeping discharge will be descended, and has a kind of by writing the rapid downward trend appearance of image quality that defective causes.

But simple square wave and do the data pulse and can make and write pulse (scanning impulse and data pulse) and be located at the discharging efficiency that can not reduce to keep interdischarge interval under the littler pulsewidth in the present embodiment, with having staircase waveform that two rank descend.The width that writes pulse can be made as 1.25 μ s.

By will write pulse be set at narrower, just can the phase that writes to drive at a high speed.When drive such as be used in have in the high-resolution high-definition television have the high definition PDP of a large amount of sweep traces the time this setting means extremely useful.

Even present embodiment uses and narrowly writes pulse still can to reach the stable reason that writes as follows:

Carry out as follows from writing the discharge operation that the phase keeps the phase to discharge.At first write pulse and between scan electrode and data electrode, discharge by applying.The result of this element task makes applying when keeping pulse, can and keep at scan electrode and keep discharge between the electrode.

If as data pulse, shown in experiment 4B, delay time than long and discharge time-delay (rising to the time of the peak value that discharges from pulse) about 700-900ns to the discharge of discharging from applying pulse with simple square wave.This means the short more just easy more generation discharge defect of time between data pulse rising and decline.In addition, keep the interim discharge time-delay of also causing, make luminous instability in discharge.

But if use the two rank falling waveform that produce from two add pulses as data pulse, the discharge time-delay then shortens to 300-500ns, and finishes discharge at short notice as in the present embodiment.Shorten from the time pulsewidth (being pulsewidth) that rises between the decline even this means data pulse, also can discharge reliably, to carry out stable writing.

Also can carry out following observation.

When being used as data pulse,, then can realize short bursts of data and high-speed driving if it can rise to high voltage with simple square wave.

But in the data driver that tradition adopts in PDP, relation reciprocal is arranged between the conversion ratio of the voltage of rising stage and the voltage endurance capability.Therefore to make the driving circuit that can be raised to the above high pressure of 100V very difficult instantaneously, and cost is high.

If produce pulse by first and second superimposed pulses to form staircase waveform, then driver IC (power MOSFET) just is used in each first and second pulse producer.This driver IC is at 100V or to be lower than the conversion ratio of low withstand voltage following pulse rising stage of voltage of 100V very fast.This means and to drive with high speed by high pressure.

Like this, PDP driving method of the present invention adopt the cost drive circuit with realize at a high speed, stable writing.

As the present invention, when writing pulse with the conduct of two rank decline staircase waveforms, first rank descend and should preferably be located in the scope of 10V-100V.This is because all be difficult to realize low withstand voltage driver IC being lower than the waveform that the 10V and first rank descend greater than 100V.

Experiment 4A

The data pulse that constitutes by the waveform that pulsewidth PW is set as various values is applied to and drives PDP on the data electrode, and has measured at the wall charge transfer quantity Δ Q[PC that writes before and after the discharge].Data pulse voltage V _DataBe set at 60,70,80,90 and 100 volts.

Be connected to the PDP device by wall charge detecting device and measure wall charge transfer quantity Δ Q the 3rd embodiment.

Figure 19 illustrates measurement result, and it illustrates at data pulse voltage V _DataThe data pulse widths PW of each value and the relation between the wall charge transfer quantity Δ Q.

Among the figure, can see and work as V _DataDuring for 60V, if pulsewidth PW is in 2.0 μ s or bigger scope the time, wall charge transfer quantity Δ Q can remain on a high value, and like this, writing discharge in this scope can roughly normally carry out.But work as V _DataWhen being 60 volts, can see flicker in a small amount.

If but V _DataΔ Q is made as and is higher than this value, what for to after pulsewidth PW reduces, still can remain on high value, writes discharge and still can normally carry out.Work as V _DataWhen being 100 volts, even when pulsewidth was 1.0 μ s, wall charge transfer quantity Δ Q can be about 6[pC] the high value, and can normally write discharge.

From then on can find out the voltage V of data pulse _DataBe worth high more, even then under narrower pulse width PW, also can obtain the wall charge transfer quantity of high stable.

Experiment 4B

Can be with the maximum voltage V that resembles in the present embodiment _pBe that two rank decline staircase waveforms that 60 volts square wave and maximum voltage are 100 volts are done the data pulse and driven PDP.Test voltage waveform and the wall charge transfer quantity Δ Q waveform that is applied in each case with the average discharge time-delay that writes discharge.The also flicker of test screen.

Measure every kind of waveform with digital oscilloscope.Eliminate and respectively measure noise by the mean value of getting 500 scannings.Table 1 illustrates this result of experiment:

Table one

	Maximum voltage V p[volt]	Average discharge time-delay [μ s]	Flicker
				Square wave
	60	1.86	Have a small amount of
				The waveform of the 4th embodiment	100	0.76	Do not have

From these results, can see, reduce discharge time-delay and screen sudden strain of a muscle as data pulse with two rank decline staircase waveforms.

The 5th embodiment

Figure 20 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

In the present embodiment, with rising staircase waveform as data pulse on two rank.

Impulse summation circuit described in first embodiment can be used as the data pulse generator 123 of Fig. 7, applies as data pulse with rising staircase waveform on two rank.

If with simple square wave in the prior art, will experience the rapid rising of a voltage in pulse rise time, like this, as testing shown in the 5A, luminously become stronger by what data pulse caused, and wall voltage becomes inhomogeneous.Identical among its reason and first embodiment in the situation of initialization pulse.

If luminously produced by data pulse, then it is just being kept on the light that discharge sends as optical superposition, and can make image quality decline when hanging down the color range demonstration.When with the ramp waveform input image signal and when carrying out gray level display by data pulse cause luminous very strong, then the deterioration of image quality is obvious especially.

, set lowlyer herein if be added to the voltage of the data pulse of data electrode, luminous being inhibited that causes by data pulse then, but the discharge time-delay that writes discharge then increases.This means to have produced and write defective and easier generation image quality deterioration.

If but data pulse used when rising staircase waveform on two rank that resemble in the present embodiment, the change in voltage on each rank is less, and pulse can be risen to high voltage, makes luminous inhibition that is caused by data pulse and can not produce to write defective.

As the 4th embodiment, with having 100 volts or being lower than 100 volts low withstand voltage driver IC as first and second pulse producers in the impulse summation circuit, then can high-speed driving PDP.Even on writing in the pulse, rise staircase waveform, rise on second rank and should preferably be located in the scope of 10V-100V with two rank.

Experiment 5A

Drive PDP10 with the correlation technique driving method that adopts simple square wave as data pulse, and can observe by writing discharge and keeping luminous that discharge produces.

Figure 21 A illustrates when writing discharge, with data pulse voltage V _Data, scan pulse voltage V _SCN-SUSWith luminous intensity situation over time.Figure 21 B illustrates when keeping discharge with keeping pulse voltage V _SCN-SUSWith luminous intensity situation over time.

Can observe the peak brightness that writes discharge shown in Figure 21 A greater than first keeping the peak brightness of pulse, and have the peak brightness area identical of keeping pulse with second by what keep that pulsed discharge produces.

Experiment 5B

With rising staircase waveform on simple square wave of describing in the present embodiment and two rank is that data pulse drives PDP, and measures the flicker of image quality and screen.

Produce data pulse with given waveform generator, and before being applied to PDP, amplify its voltage with the high speed high-voltage amplifier.Maximum voltage V in both cases _pBe 100V.Table two illustrates experimental result.

Table two

	Maximum voltage V p[volt]	The displayed image quality	Flicker
				Square wave
	100	Medium tone is interrupted	Do not have
				The waveform of the 5th embodiment	100	Satisfied	Do not have

From these results as seen, the waveform that uses present embodiment can produce more satisfied middle tone gray level display and flicker as data pulse and be less than situation when adopting simple square wave, thereby can produce excellent picture.

The 6th embodiment

Figure 22 is a sequential chart, and the PDP driving method relevant with the embodiment of the invention is shown.

Present embodiment is kept pulse with the conduct of two rank decline staircase waveforms.

Preferably be used as the impulse summation circuit of explaining among second embodiment and as shown in Fig. 5 and 6, keep pulse producer 112a and 112b as keeping pulse in order to apply this two rank decline staircase waveforms.To resemble simple square wave in the correlation technique when keeping pulse when driving PDP, and keep pulsed discharge and set highly more, it is then strong more to discharge, and makes the light can high brightness luminescent.But,, then when descending, also have weak discharge and produce abnormal operation if the discharge when rising is too strong as hereinafter testing shown in 6.

This phenomenon is generally known as from erasure discharge, and the wall electric charge that is accumulated in the discharge cell too much will appear in strong excessively discharge when rising.This means that the situation when course of discharge when descending is with rising is opposite.If produce from erasure discharge, the wall electric charge of being accumulated by discharge when rising will reduce, and corresponding brightness is descended.In addition, when by next reciprocal pulse voltage discharge, be applied to the minimizing of the effective voltage on the discharge gas in the discharge cell and produce the abnormal operation of unsettled discharge.

If, then can avoid voltage jump occurring and having suppressed, even keep under the situation that pulse voltage is set at high level also like this from erasure discharge with keeping pulse as two rank decline ladders in the present embodiment.

Therefore, in the driving method of present embodiment, when can keeping stable operation, will keep the light that pulse voltage is set at high level and produces high brightness, thereby obtain the high-quality picture.

When keeping pulse, be limited in starting potential V if be used to keep the maximum value voltage of pulse with this kind two rank falling waveform _fJust can suppress from erasure discharge in the time of in+150 volts or the lower slightly scope, therefore, PDP is preferably in this scope and drives.

Experiment 6

Drive PDP with simple square wave as keeping pulse, measure scan electrode and keep inter-electrode voltage and brightness over time.Adopt rationally high driving voltage and similar traditional PDP driving voltage as driving voltage.

Drive PDP as keeping pulse with reasonable high voltage with two rank staircase waveforms.Measure scan electrode and keep inter-electrode voltage and brightness over time.

In addition, under above-mentioned various conditions, drive PDP, and measure the brightness under the various situations in the following manner.Observe brightness and relative brightness under the various situations of from the round values of peak brightness, calculating with photodiode.With digital oscilloscope waveform under the various situations is shown.

Figure 23 and 24 illustrates voltage V and the time dependent measurement result of brightness B.Result when Figure 23 A illustrates with square wave as common driving voltage, the result when Figure 23 B then illustrates with the square wave of reasonable high driving voltage.Figure 24 illustrates the result with two rank decline ladders of rationally high voltage.

Table three

	Maximum voltage V p[V]	Relative brightness	From erasure discharge
				Square wave	200	1.00	Do not have
Square wave	280	1.83	Have
				The waveform of the 6th embodiment	280	2.10	Do not have

Table three illustrates the maximum voltage V that keeps pulse _p, brightness measurement result (relative value) and whether exist from erasure discharge.

When with square wave as keeping pulse with common driving voltage (V _p=100 volts) when driving PDP, luminous peak value will only be observed when rising and can't observe (not producing from erasure discharge) when descending, and see Figure 23 A.But when keeping pulse with square wave with reasonable high driving voltage (V _p=when 280V) driving PDP, when descending, also can be observed little luminescence peak (generation) from erasure discharge, see Figure 23 B.

With it in pairs than, when keeping pulse with two rank decline staircase waveforms with reasonable high driving voltage (V _p=when 280V) driving PDP, only when rising, observe luminescence peak and when descending, can't observe, as Figure 24.This shows the driving method that uses present embodiment even can not produce from erasure discharge under rationally high maximum drive voltage.

Relative brightness value in the table three has disclosed when with the brightness of the brightness during two rank decline staircase waveforms when being higher than with square wave.

Keeping pulse has used two rank decline staircase waveforms and has detected luminous under the maximum voltage that is set on the various level.Can see when maximum voltage be that voltage V is kept in minimum discharge _Smin2 times of (2V _Smin) time, can't when descending, observe luminescence peak, and keep voltage from erasure discharge V when maximum voltage discharges greater than minimum _SminTwice (2V _Smin) time when descending, can be observed luminescence peak.

The 7th embodiment

Figure 25 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

Present embodiment adopts the staircase waveform that rises on two rank and descend to keep pulse.

Apply as follows on two rank rise and the decline staircase waveform keep pulse, as the impulse summation circuit among first embodiment can be used as illustrated in Figures 5 and 6 keep pulse producer 112a and 112b, and second pulse is established narrowlyer.

Can produce as follows on two rank and rise and the decline staircase waveform.Available impulse summation circuit shown in Figure 9 wherein is in series first and second pulse producers with the floating ground method.Shown in Figure 26 A, first pulse producer produces wide square wave and rises as first pulse.After specific time-delay, very narrow square wave is risen as second pulse by second pulse producer.Subsequently these two impulse summations.As variation, also can be with the first and second pulse producer parallel connections as the impulse summation circuit.Shown in Figure 26 B, by first pulse producer wide square wave is risen first pulse after specific time-delay from low level, second pulse is risen subsequently from high level by the narrow square wave of second pulse producer, rise and the decline staircase waveform by two impulse summations being produced on two rank.

When the simple rectangular pulses of similar correlation technique is used as when keeping pulse and driving PDP, the rising of driving voltage will make brightness raise, and the also rising of discharge current and power consumption with being directly proportional.Therefore, the rising of driving voltage is very little to the influence of luminescence efficiency.

If rise on two rank and the decline staircase waveform is used as and keeps pulse, the maximum voltage of keeping pulse can be located at a high level, and like this, even with high brightness luminescent the time, power consumption is also not too big.Compare with correlation technique, the PDP driving method of present embodiment has higher brightness, and the rate of growth of power consumption is lower than the rate of growth of brightness, thereby discharging efficiency is increased.

This be since use rise on two rank and the decline staircase waveform as keeping pulse, the phase place of keeping pulse voltage by will being added to the discharge cell and the phase alignment of discharge current have suppressed the generation of invalid power.

Also can reach same effect by keeping pulse, definitely necessarily change the decrement phase of pulse into two rank with the staircase waveform that rises on two rank.

In order further to improve discharging efficiency, when keeping pulse and rise on by two rank, the rising of voltage is set to starting potential V in first rank _fBe not less than V _f-20V but be not more than V _fIn the scope of+30V, the voltage hold-time between rising on the liter and second rank on first rank then is set at discharge time-delay T _DfBe not less than T _Df-0.2 μ s but be not more than T _Df+ 0.2 μ s.

Experiment 7A

With rising on two rank and the decline staircase waveform is kept pulse and driven PDP, when keeping discharge by watching V-Q Lissajous figure to be evaluated at producing in the cell that discharges amount of power consumption.Produce by given waveform generator and to keep pulse and after its voltage is amplified by the high speed high-voltage amplifier, be applied on the PDP.

1 cycle that V-Q Lissajous figure is illustrated in pulse change is accumulated in the situation that the wall charge Q in the discharge cell changes in the form of a ring.The power consumption W of annulus area WS in V-Q Lissajous figure when discharge has certain relation, and this relation is represented by following equation (1).Therefore, by observing this V-Q Lissajous figure just can calculate power consumption.

(1) W=fs (notes f is a driving frequency)

Carrying out this and measure, is to measure the wall charge Q that adds up in the cell that discharges by the wall charge detecting device is linked to each other with PDP.This device uses and the identical principle of Sawger-Tower circuit of assessing characteristics such as strong dielectric.

V-QLissajous figure when Figure 27 illustrates and keeps pulse and drive PDP with simple square wave, a figure for low voltage drive PDP time the, and the figure of b for the time with high voltage drive PDP.

As shown in the figure, when keeping pulse with simple square wave, Lissajous figure a is similar parallelogram with b.This shows that when using rect.p. the rising of driving voltage can make power consumption raise with being directly proportional.

Figure 28 is V-Q Lissajous figure, and the situation when liter and decline staircase waveform are kept pulsed drive PDP on two rank is shown.

V-Q Lissajous figure in this accompanying drawing is a parallelogram flat rhombus rather than Figure 28.

Even the wall charge transfer quantity that occurs in the discharge cell of the V-Q Lissajous figure that this means Figure 28 and the V-QLissajous figure of Figure 27 is identical, annulus area is but little than the latter.In other words, concerning same luminous quantity, power consumption but reduces significantly.

Rise on two rank and decline staircase waveform when keeping pulse and driving PDP, just up voltage and rise to the various values of the voltage hold-time that second rank rise from first rank on first rank has been measured V-Q Lissajous and has been schemed.As a result, the last up voltage when first rank is located at V _f-20V is to V _fDuring+30 scope, observe a more flat ring.When voltage hold-time is located at T _Df-0.2 μ s is to T _DfDuring the scope of+0.2 μ s, also measure a more flat ring.

Experiment 7B

Keep pulse with liter and decline staircase waveform on simple square wave and two rank and drive PDP 10, and measure every kind of brightness and power consumption under the situation.

As test 6, from the integrated value of peak brightness, calculate the relative brightness value.Also measure the power consumption when driving PDP and from relative brightness and relative power consumption, calculate the relative brightness efficiency eta.Table four illustrates each relative value of relative brightness, relative power consumption and relative brightness efficient.

Table four

	Relative brightness	Relative power consumption	Relative efficiency
				Square wave	1.00	1.00	1.00
The waveform of the 7th embodiment	1.30	1.15	1.13

As seen, use on two rank to rise with the decline staircase waveform and compare when keeping pulse with simple square wave from these results, can make brightness increase by 30%, it is about 15% that the increase of power consumption then is suppressed at, luminance efficiency increase by 13%.

The PDP driving method of present embodiment, compare with the driving method of relevant technologies can be higher brightness and the luminescence efficiency driving that realizes high-quality.

The 8th embodiment

Figure 29 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

Present embodiment adopts the identical but waveform of the situation with the 7th embodiment to have on two rank of following characteristics liter and decline staircase waveform keep pulse.

Figure 30 illustrates the waveform of using in the present embodiment of keeping pulse.

(1) first rank rise to and the starting potential V in the cell that discharges _fVoltage much at one.

(2) at second raised bench, can measure its voltage for the sine function of trigonometric function, the maximum point of change in voltage and peak discharge current point are much at one.

It is identical when (3) voltage that begins to descend almost stops with discharge current.

(4) first times depression of orders drop to minimum sustaining voltage V fast with the cosine function of trigonometric function _sNear.Minimum sustaining voltage V referred in this _sThe minimum sustaining voltage of using for simple rectangular wave drive PDP the time.By scan electrode 12a in PDP 10 with keep and apply voltage between the electrode 12b and make the discharge cell be in illuminating state, reduce to apply voltage bit by bit and read the voltage that is applied when extinguishing first and record voltage V at the discharge cell _s

In order to utilize step pulse to keep pulse, can keep pulse producer 112a and 112b as shown in Fig. 5 and 6 with being used for as the described impulse summation circuit of the 8th embodiment with above-mentioned unique features.But be used as second pulse producer with pulse oscillator, make the variation of second pulse rise and descend with trigonometric function with RLC (RLC resistance-inductance-capacitance) circuit.

In other words, available following method produces the waveform of These characteristics.Employing has the impulse summation circuit of first and second pulse producers that the floating ground mode with Fig. 9 is in series.As Figure 31 A, first pulse of wide waveform is risen by first pulse producer.After regulation time-delay, second pulse of the extremely narrow waveform that changes with trigonometric function is risen by second pulse producer.With two impulse summations.Another program is to use the impulse summation circuit, and first and second pulse producers wherein are connected in parallel to each other.As Figure 31 B, make first pulse of wide square wave rise to one than low level by first pulse producer.Subsequently, after the regulation time-delay, make narrow second pulse that changes with trigonometric function of wave amplitude rise to higher level by second pulse producer.The waveform that two impulse summations is had These characteristics with generation.

Can adjust the slope that second pulse is risen and descended by the time constant of regulating the rlc circuit in second pulse producer.

Same with the 7th embodiment, the driving method of present embodiment has improved brightness, has suppressed the increase of power consumption simultaneously, and has improved luminescence efficiency.But the effect of embodiment generation is big a lot of thus.

Use the waveform of present embodiment that the higher reason of luminescence efficiency is up to the phase place that is later than discharge current by use above-mentioned (1) and (2) characteristic in the phase place of the rising stage on second rank change in voltage.This produces a kind of situation in the discharge cell, after beginning to discharge in this cell, apply a superpotential from power supply electric energy is injected into the plasma in the cell that discharges with being compelled to.

In addition, be applied to such a case in the discharge cell, luminescence efficiency is improved by being created in to take place in luminous period high voltage concentrated.This available above-mentioned characteristic (3) and (4) reach.

For reason given above can obtain following conclusion.

Rise on two rank and decline staircase waveform when keeping pulse, preferably set the phase place that is later than discharge current, like this, can improve luminescence efficiency in the phase place of the rising stage on second rank voltage (terminal voltage of discharge cell) variation.

When the two rank waveforms that use second rank to rise by trigonometric function are kept pulse, rise the discharge cycle T that best Ying Zaiyi has discharge current to flow through on second rank _DiseIn carry out, thereby can improve luminescence efficiency.

So-called discharge phase T _DiseBe meant from the charge period of discharge cell when being charged to its capability value _TchgWhen finishing to discharge current till having flowed during.The static capacity of cell " discharge " herein can be taken as by scan electrode, keep the geometry static capacity that the structure of the discharge cell that electrode, dielectric layer and discharge gas form is determined.As a result, discharge phase T _DiseCan be described as and " be charged to the charge period T of its how much static capacities from the discharge cell _ChgDuring between finishing to finish " to discharge current.

In another variation of present embodiment, when when first and second impulse summations are produced a step pulse, the pulse that first pulse is risen in order to trigonometric function.Generation is with the pulse on first and second rank of trigonometric function rising, used as keeping pulse.

When use this kind waveform keep pulse the time, can luminescence efficiency be improved further.In this case, first rank rise to from discharge phase T _DiseBegin the discharge phase T when discharge current reaches its maximal value _DscpSecond rank rise to discharge current and reach its maximal value to discharge phase T _DiseDuring between the end.

Experiment 8A

The waveform that utilization has a These characteristics is kept pulse and is driven PDP.Measure the voltage V between discharge cell electrode (scanning and keep electrode), the wall quantity of electric charge Q, the wall change in charge amount dQ/dt that in the discharge cell, add up and the brightness B of PDP, and observation V-Q Lissajous figure.

The same carrying out in the measurement of wall charge Q, brightness B etc. and the experiment of the 7th embodiment.

Figure 32 and 33 illustrates the result of these measurements.In Figure 32, provide electrode voltage V and wall voltage Q along time shaft, and wall voltage variation delta Q and brightness B.Figure 33 is V-Q Lissajous figure.

From Figure 32 as seen, in the rising stage, it is the point (t among the figure that begins to flow at discharge current that the voltage that rises on second rank rises ₁) begin immediately afterwards, and the phase delay that the voltage on second rank rises arrives after the phase place of discharge current.The peak that voltage V rises is limited in maximum discharge current (t among the figure constantly ₂) near.

At brightness B is to match with the period that high voltage is applied on the discharge cell period of high level, shows that high pressure mainly is added between light emission period in the discharge cell.

The V-Q Lissajous figure of Figure 33 is flat rhombus, and its left and right end has crooked sawtooth.Even these serrate show discharge cell mesospore charge transfer quantity and keep that annular area still diminishes when identical.In other words, although luminous quantity is identical, power consumption has diminished.

Experiment 8B

Drive PDP 10 with the method identical, wherein keep pulse with simple square wave and with the staircase waveform of present embodiment with experiment among the 7th embodiment.Measure brightness and power consumption, and from relative brightness and relative power consumption, calculate relative luminous efficiency.Table five illustrates each value of relative brightness, relative power consumption and relative luminous efficiency.

Table five

	Relative brightness	Relative power consumption	Relative efficiency
				Square wave	1.00	1.00	1.00
The waveform of the 8th embodiment	2.11	1.62	1.30

From these results as seen, with the staircase waveform in the present embodiment, keep the pulsion phase ratio with simple square wave brightness is doubled, the increase of power consumption then is suppressed at about 62%, and luminescence efficiency improves 30%.

Present embodiment shows an example, and second rank of its rising stage of waveform of this example and first rank of decrement phase are the waveforms that changes with trigonometric function, but also available other continuous function reaches similar effects.The waveform of for example also available exponential function or Gaussian function.

The 9th embodiment

Figure 34 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

The present invention adopts the rate of voltage rise when rising to keep pulse for the trapezoidal wave that does not influence driving.

This rising ramp waveform can be used as keeps pulse, it with trapezoidal wave generation circuit shown in Figure 35 as Fig. 5 and pulse producer 112a and the 112b of keeping shown in Figure 6.This trapezoidal wave generation circuit is made of clock pulse oscillator 151, triangle wave generating circuit 152 and voltage limiter 153.Voltage limiter 153 with voltage clamping on a certain level.In trapezoidal wave generation circuit, clock pulse oscillator 151 is according to the square wave of trigger pip generation shown in Figure 36 A from clock-pulse generator 103.Triangular waveform generation circuit 152 is according to the triangular wave of this square wave generation shown in Figure 36 B.Voltage limiter 153 blocks the crest of triangular wave to produce the trapezoidal wave shown in Figure 36 C subsequently.

As Figure 35, the saw-tooth wave generating circuit of available mirror image integration is as triangular wave generator 151.The saw-tooth wave generating circuit of the mirror image integration of Figure 35 has been described in the Denshin Tsushin Handobuku that has mentioned.Also can be used as voltage limiter 153 such as the Zener diode voltage limiter.

Keep pulse with the rising ramp waveform, keep the pulsion phase ratio, can make power consumption remain on low-level and can not reduce brightness with the simple square wave of correlation technique.In other words, can low-power consumption obtain the high-quality picture.

Reason is, the voltage of keeping between the pulse rising stage is raise an inclination, so that the voltage that applies on the point of maximum discharge current is higher than the voltage that discharge starting point place applies, this is identical with situation among the 8th embodiment.

As the another kind of variation of present embodiment, the available rising stage for tilt and decrement phase be the waveform on two rank keep pulse obtain with the 7th embodiment in identical effect.

The angle of up-wards inclination is preferably in 20V-800V/ μ s in keeping pulse.When keeping pulse width is 5 μ s or more hour, angle should be preferably in the scope of 40V-400V/ μ s.

Experiment 9A

The pulse of keeping with the rising slope shape drives PDP, and by the mode of the experiment 8B of the 8th embodiment measure voltage V between electrode (scanning and keep electrode), the variable quantity dQ/dt of the wall quantity of electric charge Q, the wall quantity of electric charge Q that in the discharge cell, accumulate and the brightness B of PDP.Also observe V-Q Lissajous figure.

The up-wards inclination of keeping pulse is 200V/ μ s.

Figure 37 and 38 illustrates these measurement results.In Figure 37, provide electrode voltage V, wall voltage Q, wall voltage variation delta Q and brightness B along time shaft.Figure 38 is V-QLissajous figure.

From Figure 37 as seen, at the point (t among the figure of peak discharge current ₂Point, it also is the point that peak brightness occurs) near, voltage V is higher than the point (t among the figure that begins to flow at discharge current ₁) voltage located.

The V-Q Lissajous figure of Figure 38 is the rhombus of an elongated flat.This V-QLissajous figure is made of oblique left and right limit, and cause owing to starting potential is lower than end voltage on these both sides.

Remain unchanged even this shows at discharge cell mesospore charge transfer quantity, keep pulse with the conduct of rising tilt waveform and annulus area is diminished with comparing with simple square wave.In other words, although luminous quantity is identical, power consumption is less.

Experiment 9B

Same method drives PDP 10 in the experiment with the 7th embodiment, keeps pulse with the rising oblique wave of simple square wave or present embodiment.Measure brightness and power consumption under every kind of situation, and from relative brightness and relative power consumption, calculate relative luminous efficiency η.Table six illustrates each value of relative brightness, relative power consumption and relative luminous efficiency η.

Table six

	Relative brightness	Relative power consumption	Relative efficiency
				Square wave	1.00	1.00	1.00
The waveform of the 9th embodiment	0.93	0.87	1.07

From these results as seen, keep pulse with the acclivity pulse of present embodiment and can make that brightness reduces 7%, power consumption reduces 13% with comparing with simple rectangular pulses, like this, luminescence efficiency increases about 7%.

The tenth embodiment

Figure 39 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

In the present embodiment, keep the phase added first in discharge and keep pulse and adopted on two rank and to rise and the waveform alternately that descends, but since second keep pulse use with correlation technique in identical simple square wave.

To keep pulse first and have on two rank and rise and falling waveform in order only to make, with the impulse summation circuit described among first embodiment as shown in Figure 5 keep pulse producer 112b.And be provided with switch usefulness for the second pulse producer open and close.Only just open (conducting) when having applied first second pulse producer when keeping pulse.

When applying first when keeping pulse, shown in Figure 26 as the 7th embodiment, first pulse that first pulse producer is produced and produced on two rank by second impulse summation that second pulse producer produces rises and two rank decline staircase waveforms.On the other hand, when apply second and subsequently keep pulse the time, only produce first pulse by first pulse producer.

When will with such simple pulse in the relevant technologies when keeping pulse, by apply in the discharge phase of keeping first to keep the discharge that pulse produces be that unsettled (discharge probability is low) and luminous quantity are less.This is one of reason of being dodged by screen the image quality deterioration that causes.

Provide below by first and keep the lower reason of discharge probability that pulse produces.

Always say time-delay there be (discharge time-delay) the discharge current to producing from applying pulse.Discharge is delayed time and applied voltage very strong correlativity.This area thinks that extensively voltage is high more, and the discharge time-delay is more little, and its distribution is very narrow.Discharge time-delay is long to be caused the problem of non stationary discharge also to be applicable to keeping in the pulse.

But be added to the voltage V on the discharge gas in the discharge cell _GasDepend on added driving voltage and the wall voltage that is accumulated on the dielectric layer that is covered in electrode on the power supply outside the discharge cell.In other words, wall voltage has a strong impact on the discharge time-delay.

Therefore, owing to before write discharge the inhomogeneous of wall electric charge of adding up and cause that easily first keeps the discharge time-delay and the non stationary discharge of pulse.

But as in the present embodiment rising on two rank and falling waveform is done first and kept pulse, and compare with simple square wave, discharging delays time then reduces.Therefore when applying first when keeping pulse, discharge probability improves, thus the minimizing screen flicker.

, do first with simple square wave and keep pulse, if the stability that can reach at interdischarge interval too with broad pulse.But can make used pulse very narrow as doing pulse with two staircase waveforms of addition in the present embodiment, can more speed drive like this.

Rise and the decline staircase waveform does first when keeping pulse the raising of the probability of preferably guaranteeing in the following manner to discharge on according to said method with two rank: rise on first rank and should be raised to minimum discharge and keep voltage V _sNear.After second rank are raised to peak voltage level, make waveform from descending rapidly near the discharge end caps.The voltage that first rank descend preferably drops to minimum discharge and keeps voltage V _sNear.

Rising to the period that first rank descend from second rank, in other words is maximum voltage retention time P _WmaxPreferably should be set at and be not less than 0.2 μ s and be not more than 90% of pulsewidth PW.

In addition, the first maximum voltage retention time PW that keeps pulse _Max1Should be set at than second with afterpulse PW _Max2Long 0.1 μ s of maximum voltage retention time.Under this setting, first discharge probability of keeping pulse obviously increases and can obtain the satisfied image of flicker free.

Experiment 10A

Do first with the staircase waveform of the simple square wave of correlation technique and present embodiment and keep pulse and drive PDP, and measure the voltage V between electrode (scanning and keep electrode) in the discharge cell in all cases _SCN-SUSLuminescence efficiency B with PDP.

Keep pulse by producing, and its voltage is amplified by the high speed high-voltage amplifier before being applied to PDP to waveform generator.Measure voltage waveform and brightness waveform by digital oscilloscope.

Figure 40 illustrates these measurement results, and A is for being used as first the situation when keeping pulse when square wave, and B to be staircase waveform be used as first the situation when keeping pulse.In two figure, provided electrode voltage V along time shaft _SCN-SUSWith brightness B.

In Figure 40, in the period between pulse rising starting point and luminescence peak, in other words be discharge time-delay, being lower than in A in B.In addition, can see luminous being better than in A in B by discharge generation.

Experiment 10B

Use maximum voltage V _pBe 180 volts simple square wave and maximum voltage be 230 volts two rank on rise and the decline staircase waveform is done first and kept pulse and drive PDP 10.Measure voltage waveform and brightness waveform under the various situations, and calculate average discharge time-delay.Also observed brightness and screen dodge.These results as shown in Table 7.

Table seven

	Maximum voltage V p(volt)	Average discharge time-delay [μ s]	Relative brightness	Flicker
					Square wave	180	1.86	1.00	Have
The waveform of the tenth embodiment	230	0.81	1.11	Do not have

From these results as seen, keep pulse with two rank staircase waveforms works first and can reduce discharge time-delay and screen sudden strain of a muscle.

The PDP driving method of present embodiment can make PDP obtain the high-resolution picture of high-quality.

The 11 embodiment

Figure 41 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

Present embodiment is done erasing pulse with rising staircase waveform on two rank.

For two such rank rising waveform are done erasing pulse, can be with the erasing pulse generator 113 that is used as impulse summation circuit illustrated among first embodiment among Fig. 6.

When having used the simple rectangular pulses that resembles in the relevant technologies, the last one discharge trend when rising, voltage is arranged after the voltage jump.This strong discharge make produce on the whole screen one stronger luminous, contrast is descended.

When producing the strong discharge of this kind, the remaining wall quantity of electric charge inhomogeneous this that become easily will produce mistake and discharge in next drive sequences in the discharge cell having added erasing pulse after.

But when having used two rank rising waveform to do erasing pulse, make to apply voltage and rise and avoided the mass mutation in the voltage, make luminously to be suppressed and to make the wall electric charge to be wiped equably.

In the present embodiment, make first, second pulse producer in the impulse summation circuit, with by first, second superimposed pulses is produced erasing pulse with low withstand voltage driver IC.This can make driving carry out at high speed.

If on this kind two rank, rise the voltage V in rising on first rank of staircase waveform ₁With respect to crest voltage V _eToo little, just there is relatively large light to send in then on second rank, rising, like this, the major part that loses in the contrast is improved.So V ₁With V _eRatio should preferably be located at and be not less than 0.05-0.2 and (V _e-V ₁) and V _eRatio be not more than 0.8-0.95.

In addition, if be accomplished to the period that second rank begin on rising stage first rank, in other words, the flat of the first rank tp is compared too wide with pulsewidth tp, then have the infringement effect.Therefore, tp should be located at 0.8 or littler with the ratio of tw.

For further improving image quality, the voltage V in rising stage first rank ₁Preferably should be located at V _f-50V to V _fIn the scope of+30V, maximum peak voltage V _eAt V _fTo V _fIn the scope of+100V.Herein, V _fBe starting potential.

Experiment 11

Drive PDP with rising staircase waveform on two rank do erasing pulse.When driving, crest voltage V _eTw is set as fixed value with pulsewidth, but the flat on first rank and the ratio of pulsewidth tw and the voltage (V on second rank among the rising stage tp _e-V ₁) and crest voltage V _eRatio be set as various values, and measure contrast by the identical mode of the experiment among first embodiment.

Figure 42 illustrates these measurement results.Ratio and the (V of tp and tw when doing erasing pulse with two rank rising waveform shown in the figure _e-V ₁) and V _eRatio and the relation between the contrast.

The acceptable scope of result is represented in the shadow region among the figure, for the contrast height and by writing the fewer scope of brightness variation that defective causes.The unacceptable result of region representation outside the shadow region.

As seen from the figure, tp should preferably be located at 0.8 or littler, (V with the ratio of tw _e-V ₁) and V _eRatio should preferably be located at 0.8-0.95 or littler.But if tp and tw and (V _e-V ₁) and V _eIf must be too low, then can not obtain effect, like this, ratio preferably should be located at and be higher than 0.05.

Present embodiment is done erasing pulse with rising staircase waveform on two rank, but also available have three or multistage multistage staircase waveform realize same good image quality.

The 12 embodiment

Figure 43 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

Present embodiment is done erasing pulse with two rank falling waveform.

The impulse summation unit of describing in should the most handy second embodiment is as the erasing pulse generator 113 among Fig. 6, with this two rank falling waveform as erasing pulse.

When doing erasing pulse with the simple square wave in the relevant technologies, at erasure discharge discharge time-delay is just arranged, its pulsewidth is too narrow will to be made to wipe and makes a mistake and image quality descends.With two rank falling waveform of present embodiment with compare do erasing pulse with simple square wave, still keep wiping accurately when very narrow even can set in erasing pulse.

The width that reduces erasing pulse can make erasing period reduce.This makes the phase of writing and keeps corresponding lengthening of phase, thereby obtains high brightness and high image quality.

In addition, make first and second pulse producers in the impulse summation circuit with by first and second superimposed pulses are produced erasing pulse with low withstand voltage driver IC.This can make driving to carry out at a high speed.

When by this method with two rank decline staircase waveforms when the erasing pulse, can accurately wipe and pulse width can be set narrowly as much as possible.The Pwer in period that finishes to the maximum voltage maintenance phase during as a result, from rising should fix on T _Df-0.1 μ s to T _DfBetween+0.1 μ s.Herein, T _DfBe the discharge time-delay.

When having used this two rank decline erasing pulses, maximum voltage Vmax should be set in V _fTo V _fIn+the 100V, to obtain the most satisfied image quality.

Experiment 12

Use maximum voltage V _pFor the 180V pulsewidth is that the simple square wave of 1.50 μ s and maximum voltage are that the 200V pulsewidth is that the two rank decline staircase waveforms of 0.77 μ s drive PDP 10 as erasing pulse.The average discharge time-delay of measuring voltage waveform and the brightness waveform under every kind of situation and measuring erasing period.The view screen situation is to judge whether erase operation is successful.

Table eight

	Maximum voltage V p(volt)	Average discharge time-delay [μ s]	Pulsewidth [μ s]	Erase operation
					Square wave	180	1.86	1.50	Satisfied
The waveform of the 12 embodiment	200	0.77	0.75	Satisfied

Table eight illustrates these measurement results, has disclosed that erase operation is all satisfactory in both cases.

But can see, can reduce discharge time-delay with staircase waveform widely with comparing do erasing pulse, and the used PDP driving method of present embodiment still can reach satisfactory performance with burst pulse the time with simple square wave.

Do erasing pulse with two rank decline staircase waveforms in the present embodiment, but with having three rank or more multistage multistage decline staircase waveform also can reach same effect.

The 13 embodiment

The used PDP of present embodiment has the basic structure identical with the PDP 10 of Fig. 1, and replaces neon-xenons or helium-xenon to make the sealing discharge gas with helium, neon, xenon and four kinds of mixed gass of argon, and the pressure of enclosure space is located at 800 to 4000 torrs, is higher than atmospheric pressure.

Figure 44 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

As shown in the figure, writing the pulse of keeping that data pulse that the phase applies and the discharge phase of keeping apply with two rank decline staircase waveforms in the present embodiment drives.In other words, present embodiment is done the data pulse and keep pulse with two rank falling waveform as the 6th embodiment with two rank falling waveform in the 14 embodiment.

The waveform character that present embodiment applies the architectural feature of PDP during with the driving PDP that below will describe combines, and to improve brightness and luminescence efficiency, suppresses the increase and the gratifying image of display quality of sparking voltage simultaneously.

When being enclosed in gas medium among the PDP, used pressure is usually less than 500 torrs.This means that the ultraviolet light that the discharge back produces mainly is that centre wavelength is the resonance line of 147nm.If but the pressure in the enclosure space too high (a large amount of atoms be enclosed in discharge space in), then centre wavelength is that the ratio of molecular beam of 154nm or 172nm is just bigger.Resonance line has the tendency of self-absorption, and molecular beam does not have self-absorption or self-absorption is very little, this means that the amount of the ultraviolet light that is reflected by fluorescence coating is bigger in the case, thereby has improved brightness and luminescence efficiency.The conversion efficiency that ultraviolet light is converted to visible light by common fluorescence coating is long more and big more with wavelength, therefore Here it is why present embodiment improved another reason of brightness and luminescence efficiency.

In traditional PD P, discharge has first glow phase, but if hyperbar is set in 800 to 4000 torrs, the then easier generation filament light-emitting state or second luminance in the present invention.The amount that this makes the electron density in positive pole improve, provide concentrated energy and improve the ultraviolet light of being sent out.

The gas medium that is sealed is the potpourri of above-mentioned four kinds of gases, and wherein the amount of xenon is less, can obtain high brightness and high-luminous-efficiency when keeping low discharge voltage.

As shown in Figure 1, in the PDP that clips the structure that discharge space places relative to one another between scan electrode and the data electrode was arranged, if set high pressure in its enclosure space, this just might produce the trend that writes defective.This is most likely because the hyperbar in the enclosure space raises starting potential.But when making initialization pulse and writing pulse with simple square wave when in correlation technique, even the pulse that writes that applies is located at high level and also can produces the discharge time-delay.As a result, be difficult to avoid writing defective.

But do the data pulse with two rank decline staircase waveforms in the present embodiment, reduced discharge time-delay, and write discharge applying to finish in the period of data pulse.As a result, increase, write defective and reduce by the wall quantity of electric charge that writes discharge generation.By two superimposed pulses are produced this staircase waveform together, promptly can make pulse producer with low withstand voltage driver IC.As a result, can drive at high speed.

In the present embodiment, two rank decline staircase waveforms also are used as keeps pulse, thereby can establish higherly with keeping pulse voltage, to increase brightness and to guarantee stably to work.Thereby can obtain the excellent picture of flicker free.

Experiment 13A

Making a kind of electrode separation is the PDP that 40 μ m and discharge gas are made up of 50% helium, 48% neon, 2% xenon or 50% helium, 48% neon, 2% xenon, 0.1% argon or 30% helium, 68% neon, 2% xenon or 30 chlorine, 67.9% neon, 2% xenon, 0.1% argon.Detect Pd and the starting potential V of each PDP _fBetween relation.

Figure 45 illustrates these results.Use the not brightness of the PDP of gas of the same race (sparking voltage is 250 volts) shown in the form under figure line.

As seen from the figure, increasing of air pressure can make starting potential raise in enclosure space, if but above-mentioned four kinds of gaseous mixture during as discharge gas, starting potential just can be limited on the lower level.

Specifically, if the potpourri of the helium with 30%, 67.9% neon, 2% xenon, 0.1% argon, then luminous better, even and starting potential is 6 at Pd and (still can remains on (less than 220 volts) in effective starting potential scope during torr * cm), this means that electrode separation d is 60 μ m, the pressure of enclosure space is 1000 torrs.

Therefore the minimum starting potential of this kind combination of gases preferably is made as 4 with Pd near Pd=4, (for example enclosure space pressure be 2000 torrs and electrode separation d is 20 μ m).

Absolute value (the particularly absolute value of starting potential) becomes with the amount of used xenon, but relativeness therebetween is constant substantially.

Experiment 13B

Driving each with the driving method as the staircase waveform of the present invention of the simple square waveform of the correlation technique of Fig. 4 and Figure 44, to have barrier ribs be 60 μ m height and pressure is the PDP of four kinds of combination gass under 2000 torrs.Carry out actual image and show, and assessment relative brightness, luminescence efficiency η and image quality (flicker).Table nine illustrates these results.

Table nine

	Relative brightness	Relative power consumption (watt)	Relative efficiency (n)	Image quality
					Square wave	1.00	1.00	1.00	A large amount of flickers
The waveform of the 13 embodiment	1.31	0.72	1.82	Satisfied

From these results as seen, when comparing with the driving method of simple square wave the time with driving method of the present invention, relative brightness, power consumption, relative efficiency and display quality are all fine.

Even this has shown when air pressure in the enclosure space of PDP is high that this display panel structure that the embodiment of the invention is told about and the combination of driving method still can obtain high brightness, high-luminous-efficiency and satisfied image quality.

In the present embodiment, driving method of the present invention is used in four kinds of gaseous mixture is closed in PDP in the enclosure space that pressure is 2000 torrs, and be on the PDP of mixed gas of xenon of 95% the neon that seals under 500 torrs and 5% at pressure.Relatively the luminescence efficiency η under each situation also can find that the efficient of last PDP is about the latter's half as much again.This has confirmed that the driving method of present embodiment and the composition of discharge gas and the combination of pressure are effective.

In the present embodiment, used data pulse and kept the example that pulse all is two rank falling waveform, but as another modified example, also can make data pulse and keep the two one of pulse or the both has two rank rising waveform and can get effect same.

In addition, though with rise on two rank or falling waveform only as data pulse and with simple square wave when keeping pulse, although efficient is lower, but still the effect can reaching in present embodiment.

The 14 embodiment

Figure 46 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

Present embodiment is made initialization pulse, is write pulse, first keeps pulse and erasing pulse with staircase waveform.

As Figure 46, in the present embodiment, as at first embodiment, to rise staircase waveform on two rank as initialization pulse, as the 4th embodiment, be used as data pulse, as the tenth embodiment, liter and decline staircase waveform on two rank kept pulse as first with two rank decline staircase waveforms, as the 11 embodiment, with rising staircase waveform on two rank as erasing pulse.

In the combination of the waveform by voltage being used in each period, contrast is improved, and the flicker that is produced by the discharge time-delay is inhibited, as mentioned below.

Do initialization and erasing pulse with staircase waveform the contrast during initialization and the erasure discharge is improved, but also have a kind of discharge time-delay Td that makes when writing discharge _AddDischarge time-delay T when keeping discharge with first _Dsus1The trend that increases.Its reason is, makes initialization pulse and erasing pulse can make discharge die down, the wall charge transfer quantity step-down that reduces charge transfer quantity and occur in the initialization phase with staircase waveform.

But in the present embodiment, reduce discharge time-delay Td by do the data pulse with staircase waveform _AddOperation and do first with staircase waveform and keep pulse and reduce discharge time-delay Td _Sus1Operation prevented discharge time-delay, thereby do not produce flicker.

In the driving method of present embodiment, promptly use 1.25 μ s wide write pulse and carry out high-speed driving the time still can obtain high contrast and satisfied image quality.

Experiment 14A

With simple square wave as writing pulse and keep pulse, and with liter on simple square wave and two rank with the decline ripple is made initialization pulse and erasing pulse drives PDP 10.Measure the average discharge time-delay Td that when writing discharge, occurs _Add(μ s), the average discharge time-delay Td that when first keeps discharge, occurs _Sus1(μ s), first keeps the contrast-ratio and the discharging efficiency P (%) of discharge.

Discharging efficiency P is by discharging into the operation of keeping discharge and carry out 10000 times and calculate keeping number of times luminous the discharge first and recording from writing.

Light with avalanche photo diode (APD) sends when observing in discharge on the digital oscilloscope carries out luminous detection.

Experiment 14B

Do initialization pulse and erasing pulse, do whole pulses of keeping with staircase waveform, to rise on simple square wave and two rank and the decline staircase waveform is used separately as and writes pulse and drive PDP 10 with simple square wave.Measure the average discharge time-delay Td that when writing discharge, occurs _Add(μ s), the average discharge time-delay Td that when first keeps discharge, occurs _Sus1Contrast-ratio and discharging efficiency P (%) when (μ s), first keeps discharge.

Experiment 14C

Do initialization pulse, erasing pulse and write pulse with staircase waveform, keep pulse as first respectively with liter and falling waveform on simple square wave and two rank and drive PDP 10.Measure the average discharge time-delay Td that when writing discharge, occurs _Add, keep the average discharge time-delay Td that when discharge occurs first _Sus1Contrast-ratio and discharging efficiency P (%) when (μ s), first keeps discharge.The result of table ten expression experiment 14A, 14B, 14C.

Table ten

From the result of experiment 14A as seen, with staircase waveform rather than simply square wave do initialization and erasing pulse can improve contrast greatly.But the average discharge time-delay Td that meanwhile, when writing discharge, occurs _AddThe average discharge time-delay Td that occurs when keeping discharge with first _Sus1To become big, and discharging efficiency P reduces.

From here with the result of experiment 14B as seen, with staircase waveform with write pulse with simple square wave and initialization pulse is compared with erasing pulse, contrast is remained on the level of improvement, and restricted T d _AddAnd T _Dsus1Increase, and suppress the decline of discharging efficiency P.

As seen the result who reaches experiment 14C from here with pulse is kept pulse with first and initialization pulse is compared with erasing pulse as writing with simple square wave, can improve contrast with staircase waveform, reduces the average discharge that writes when the discharging Td that delays time _AddAverage discharge time-delay Td when keeping discharge with first _Sus1And improve discharging efficiency P.

The 15 embodiment

Figure 47 is a sequential chart, and the PDP driving method relevant with present embodiment is shown.

In the present embodiment, as the 14 embodiment, be used as initialization pulse, write pulse and erasing pulse with staircase waveform.Staircase waveform not only is used as first and keeps pulse but also be used as all and keep pulse.

As Figure 47, in the present embodiment, as first embodiment, rise staircase waveform on two rank and be used as initialization pulse, as the 4th embodiment, two rank decline staircase waveforms are used as data pulse, as the 7th embodiment, rise on two rank and the decline staircase waveform is used as and keeps pulse,, rise staircase waveform on two rank and be used as erasing pulse as the 11 embodiment.

Apply staircase waveform by the combination day part, can improve contrast, suppress the flicker that produces by the discharge time-delay and realize high-luminous-efficiency, as described below.

In general, its luminescence efficiency of high-resolution PDP is all lower.This is because the discharge cell is more little, means that the wall surface on the unit volume of discharge space is long-pending big more, and this increases the wall surface loss from the charged particle of discharge gas and exciton.High-resolution PDP is also easier impurity, for example in manufacture process from emptying process residual steam.Easier because the interval between barrier ribs reduces to make the electric conductivity variation have this situation to take place.A large amount of impurity will make starting potential raise in discharge gas.

Therefore the simple square wave with correlation technique is difficult to stationary mode driving PDP with the then easier generation flicker of high-speed driving high-resolution PDP.But in the present embodiment, even still can stably drive high-resolution PDP with the high speed of about 1.25 μ s, and the image of full high resolution displayed.

In the PDP of high-resolution, keep pulse with staircase waveform and can improve luminescence efficiency greatly.This variation because of cell spacing among the PDP can make the effect that is obtained produce great changes.Its reason also can obtain bigger discharge current when being promptly to use simple square wave to do to keep pulse in the PDP of wide electrode is arranged, so the DeGrain of staircase waveform.But in narrow electrode PDP, keep pulse with simple square wave and mean and to obtain little discharge current, use the effect of staircase waveform just more obvious like this.

Experiment 15A

Do initialization and erasing pulse with staircase waveform, simple square wave is done all and is kept pulse, to rise on simple square wave and two rank and the decline staircase waveform is used separately as and writes pulse and drive PDP.The cell spacing is set in 360 μ m and 140 μ m.Measure relative luminous efficiency η and contrast-ratio.

Experiment 15B

Write pulse and initialization pulse and erasing pulse with staircase waveform, simple square wave is done all pulses that writes, to rise on simple square wave and two rank and the decline staircase waveform is used separately as and keeps pulse and drive PDP.The cell spacing is set in 360 μ m and 140 μ m.Measure relative luminous efficiency η and contrast-ratio.

In experiment 15A and 15B, it is gratifying observing about 400: 1 contrast-ratio.Table ten one shows the measurement result of relative luminous efficiency η.

Table ten one

From these results as seen, the cell spacing is that its luminescence efficiency of PDP of 140 μ m is lower than the PDP that the cell spacing is 360 μ m generally.

From experiment 15A as seen, no matter be with simple square wave or staircase waveform writes pulse, luminescence efficiency is all constant.But the result of experiment 15B shows the luminescence efficiency of keeping pulse generation with staircase waveform and is higher than the luminescence efficiency with simple square wave.

The result of experiment 15B also show with staircase waveform with keep the pulsion phase ratio with simple square waveform, can be about 8% with between cell being that luminescence efficiency among the PDP of 360 μ m increases, be that the luminescence efficiency among the PDP of 140 μ m improves about 30% with the cell spacing.Specifically, this shows that the pulse of doing in the high-resolution PDP with staircase waveform of keeping has improved luminescence efficiency greatly.

Therefore, making with the driving method of present embodiment can be with high-luminous-efficiency high-speed driving PDP, thereby can stably obtain showing the image of overall height sharpness.

Additional information

The present invention makes initialization pulse, writes pulse, keeps pulse and erasing pulse by using aforesaid distinct waveforms, particularly staircase waveform, and contrast, image quality and luminescence efficiency are improved.But with pulse be applied to scan electrode, the means on electrode and the data electrode kept are not limited to the foregoing description and describe, and when driving PDP with the ADS method, generally speaking can adopt these class means.

For example, in the above-described embodiments, described the example that staircase waveform initialization pulse and erasing pulse is added to scan electrode 19a, but the present invention can be by being applied to pulse data electrode 14 and keeping electrode 19b and go up and obtain same effect.

In the above-described embodiments, with the example of staircase waveform, be applied to data pulse on the data electrode 14 with step pulse, but staircase waveform also can be used as the scanning impulse that is applied on the scan electrode 19a as data pulse.

In addition, keep the phase, provided and just kept the example that pulse alternately is applied to scan electrode 19a and keeps electrode 19b in the discharge of the foregoing description.As another distortion, also can keep pulse and alternately be applied to scan electrode 19a or keep on the electrode 19b positive and negative.In the case, keep pulse with staircase waveform and can reach effect same.

The structure of the display panel of PDP not must with the foregoing description in identical.Driving method of the present invention also is applicable to and drives among conventional face discharge PDP or the opposite discharge PDP.

Possible commercial Application

Can PDP driving method of the present invention and display unit is effective on computer and television indicator, particularly on such main equipment.

Claims (2)

1, the driving method of plasma display panel is formed with a plurality of discharge cells in the described plasma display panel, described discharge cell has the first paired electrode and second electrode;

Described driving method comprises and carrying out the initialized initialization phase;

Interim in described initialization, described discharge cell is applied pulse, the mean value of the voltage change ratio of the voltage change ratio of the waveform of described pulse when rising when descending is big, and the mean value of the voltage change ratio when descending is 1V/ μ s or bigger, 9V/ μ s or littler.

2, the image display device that has plasma display panel and driving circuit thereof;

Described plasma display panel, disposed and left first liner plate and second liner plate at interval mutually, described first liner plate is provided with a plurality of paired first electrode and second electrodes, described second liner plate is provided with a plurality of third electrodes, has formed a plurality of discharge cells between described first liner plate and described second liner plate;

Described driving circuit applies pulse to described discharge cell, drives described plasma display panel;

1 frame comprises and carrying out the initialized initialization phase;

Interim in described initialization, described discharge cell is applied pulse, the mean value of the voltage change ratio of the voltage change ratio of the waveform of described pulse when rising when descending is big, and the mean value of the voltage change ratio when descending is 1V/ μ s or bigger, 9V/ μ s or littler.

Images