JP3549597B2 - Driving method of plasma display panel - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a method for driving a display panel constituted by a group of cells, which are display elements having a memory function, and more particularly to a method for driving a three-electrode, surface-discharge type AC plasma display panel (PDP). It is.
[0002]
[Prior art]
FIG. 13 is a schematic plan view of a conventional PDP disclosed in, for example, JP-A-6-186927, FIG. 14 is a schematic cross-sectional view showing a basic structure of the cell of FIG. 13, and FIG. FIG. 4 is a waveform chart showing a driving method. In FIG. 13, 101 is a panel main body, 102 is an X electrode, 103K (K is an arbitrary number from 1 to 1000) is a Y electrode, 104K is an address electrode, 105 is a pair of X electrodes and one Y electrode. M × 1000 cells are formed at the intersections with the address electrodes, 106 is a wall separating the cells 105, and 107K is a display line.
[0003]
14, reference numeral 108 denotes a front glass substrate, 109 denotes a rear glass substrate, 110 denotes a dielectric layer that covers the X electrode 102 and the Y electrode 103K, and 111 denotes a protective film made of an MgO film or the like that protects the dielectric layer 110 from discharge. Reference numeral 112 denotes a phosphor which emits a color when excited by ultraviolet rays emitted as a discharge gas, and 113 denotes a discharge space.
[0004]
FIG. 15 is a waveform chart showing a conventional PDP driving method, and shows one driving cycle. First, the Y electrode of the selected line is set to the GND level, the potential of the Y electrode of the non-selected line is held at the Vs level, the write pulse 136 including the potential Vw is applied to the X electrode 102, and the discharge of all cells in the selected line is performed. Is performed. Subsequently, the potential of the Y electrode of the selected line is returned to the voltage Vs, the sustain discharge pulse 137 is applied, and after the sustain discharge is performed, the narrow erase pulse 138 is applied to the Y electrode of the selected line. Erase discharge is performed in all cells in the line.
[0005]
Next, a GND level address pulse (writing pulse) 139 is applied to the Y electrode of the selected line, the potential of the Y electrode of the non-selected line is held at the Vs level, and a voltage is applied to the address electrode corresponding to the cell to be turned on. An address pulse (writing pulse) 140 of Va is applied, and a cell selected as a cell to be turned on is discharged.
[0006]
Next, sustain discharge pulses 141 and 142 are alternately applied to the X electrode 102 and the Y electrode of the selected line, whereby the sustain discharge is repeated. In this way, display data is written to the selected line. Incidentally, reference numeral 143 denotes a sustain discharge pulse applied to the Y electrodes of the non-selected lines. In this conventional method of driving a PDP, before writing display data to a selected line, a write discharge is performed in all cells of the selected line, and then an erase discharge is performed in all cells of the selected line. Therefore, the state of all the cells in the selected line can be made uniform, and in the line sequential driving method, writing errors can be avoided and good image display can be performed.
[0007]
[Problems to be solved by the invention]
Although the conventional PDP driving method avoids the writing error as described above, all the cells are discharged between the sustain electrode pairs (between the X electrode and the Y electrode). There is a problem that a high voltage is required, and the discharge is intensified to deteriorate the contrast.
[0008]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a method of driving a plasma display panel in which deterioration of contrast is suppressed as much as possible and stable address discharge is performed.
[0009]
[Means for Solving the Problems]
A driving method of a plasma display panel according to the present invention is configured such that one field is constituted by a plurality of subfields, and an AC type plasma display panel including a plurality of cells for displaying multiple gradations by a combination of the subfields is driven. In a driving method of performing a preliminary discharge and a sustain discharge during a field period,
The preliminary discharge is
Of the plurality of cells, the discharge was started only in the cell that was performing the sustain discharge in the previous subfield ,
Subsequently , discharge is started only in cells in which sustain discharge has not been performed in the previous subfield.
[0026]
[Action]
According to the driving method of the plasma display panel according to the present invention, of the plurality of cells, the discharge is started in advance only in the cell that has performed the sustain discharge in the previous subfield, and then the sustain discharge is performed in the previous subfield. The preliminary discharge that starts the discharge occurs only in the cell in which the discharge has not been performed.
[0039]
【Example】
Embodiment 1 FIG.
In order to suppress the deterioration of contrast, it is necessary to lower the voltage of the preliminary discharge to weaken the discharge, but in this embodiment, first, a discharge is generated between the writing electrode and one electrode of the sustain electrode pair, Next, this discharge is used as a trigger to generate a preliminary discharge between the pair of sustain electrodes at a low voltage.
[0040]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a PDP according to this embodiment, FIG. 2 is a schematic configuration diagram of the PDP according to this embodiment, and FIG. 3 is a driving waveform diagram according to this embodiment.
[0041]
In FIG. 1, 1 is a front substrate, 2 is a rear substrate, 3 is an X electrode forming one of a pair of sustain electrodes provided on the back surface of the front substrate 1, and 4 is a sustain electrode provided in parallel with the X electrode 3. The Y electrode 5 which forms the other of the pair, 5 is a W electrode which is a write electrode provided on the back electrode 2 orthogonal to the sustain electrode pair, 6 is a dielectric layer covering the X electrode 3 and the Y electrode 4, and 7 is A discharge space 18 formed between the front substrate 1 and the rear substrate 2 is a phosphor or a dielectric covering the W electrode 5.
In FIG. 2, reference numeral 8 denotes a discharge cell including the intersection of the sustain electrode pairs 3, 4 and the W electrode 5.
[0042]
Next, the operation will be described with reference to the driving waveform diagram of FIG.
First, the potential of the X electrode 3 is raised to the sustain voltage Vs (200 V), and at the same time, the preliminary discharge pulse 13 of the potential Vw (80 V) is applied to all the W electrodes 5. At this time, since there is a potential difference Vw between the W electrode 5 and the Y electrode 4, discharge is started. Then, triggered by the discharge between the W electrode 5 and the Y electrode 4, a discharge is generated between the X electrode 3 and the Y electrode 4 as a preliminary discharge due to the potential difference Vs.
[0043]
Subsequently, the potential of the Y electrode 4 is set to Vs, and a erasing pulse having a potential of 0 is applied to the X electrode 3 to erase all cells. Next, at the same time as the scanning pulse 10 of the potential 0 is applied to the Y electrode 4, the writing pulse 9 of the potential Vw is applied to the W electrode 5 according to the image data, and a writing discharge occurs. Then, by applying the sustain pulse 11 alternately to the X electrode 3 and the Y electrode 4, a sustain discharge is performed and an image is displayed.
[0044]
By making the operation at the time of the preliminary discharge the same as the operation at the time of the write discharge, the potential difference between the X electrode 3 and the Y electrode 4 can be made a relatively small value of Vs (200 V), and the energy of the preliminary discharge can be reduced. It can be small and does not significantly deteriorate contrast.
[0045]
For example, according to the method of driving a PDP described in the related art, a preliminary discharge cannot be started unless a voltage of about 350 V is applied between the X electrode 3 and the Y electrode 4.
The discharge between the W electrode 5 and the X electrode 3 can be made sufficiently weak by reducing the capacitance between the W electrode 5 and the discharge space.
In this embodiment, the preliminary discharge is performed in all the cells at the same time. However, the preliminary discharge may not necessarily be performed in all the cells, but may be performed for one display line or for several display lines.
[0046]
The cell structure of the PDP may be such that the X and Y electrode pairs 3, 4 and the W electrode 5 are on the same plane as shown in FIG.
Further, here, narrow erase was used as the erase pulse, but this can be done by wide erase, erase using a blunt waveform, erase using self-erase, or erase using a blunt waveform after narrow erase. For example, a combination of a plurality of erasures may be performed.
The same applies to the following embodiments.
[0047]
Embodiment 2. FIG.
When the preliminary discharge is performed by the driving method of the first embodiment, when the discharge characteristics of the cells vary, or when the sustain discharge has not been performed in the previous field, the discharge hardly occurs when the time has elapsed since the preliminary discharge. For this reason, the cells are separately subjected to a somewhat stronger preliminary discharge for the discharge so that there is no cell in which the preliminary discharge does not occur.
[0048]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a driving waveform diagram of the PDP according to the second embodiment.
As shown in FIG. 5, first, a pulse of the potential Vs (200 V) is applied to the X electrode 3, and only the cells that have undergone the sustain discharge in the previous field are discharged first. Next, a preliminary discharge pulse is applied to the X electrode 3 and the W electrode 5. At this time, no discharge occurs in the cells that had undergone the sustain discharge in the previous field because wall charges have already been formed to cancel the preliminary discharge pulse, and only the cells that did not discharge in the previous field are newly added. Causes a discharge.
Subsequently, erasure, writing, and maintenance are performed as in the first embodiment.
[0049]
Cells that have not undergone a sustain discharge in the previous field are less likely to be discharged because the time has elapsed since the previous preliminary discharge, and a slightly stronger discharge is required to achieve a sufficient effect with one preliminary discharge. May be better.
[0050]
In this embodiment, since the preliminary discharge is separately performed for the cells for which the sustain discharge has not been performed in the previous field, for example, as shown in FIG. 5, the potential of the X electrode 3 during the preliminary discharge is slightly increased. Discharge can be caused under a condition different from that of the cell that was discharged in the previous field.
In this case, if the potential of the X electrode 3 is too high, the contrast is deteriorated, and the use of the W electrode 5 becomes meaningless. Therefore, a range of about 1 to 1.5 times Vs is considered appropriate. .
Note that the same operation is performed even if the first pulse and the second pulse of the X electrode 3 in FIG. 5 are connected as shown by a broken line.
[0051]
According to this embodiment, since the cells which have not undergone the sustain discharge in the previous field are separately subjected to the preliminary discharge, the cells in which the preliminary discharge does not occur can be eliminated.
[0052]
Embodiment 3 FIG.
According to the driving method of the PDP described in the first or second embodiment, the pre-discharge to the W electrode 5 is performed when the discharge characteristics of the cells vary, or when a very long time elapses from the pre-discharge in the previous field. There is a possibility that a cell that does not discharge only with a pulse may occur. The third embodiment solves this problem, and applies a high-voltage pulse to the X electrode 3 after applying a preliminary discharge pulse to the W electrode so as to prevent the occurrence of cells that do not discharge.
[0053]
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a driving waveform diagram of the PDP according to this embodiment.
As shown in FIG. 6, similarly to the second embodiment, first, a pulse of the potential Vs (200 V) is applied to the X electrode 3, and only the cells that have undergone the sustain discharge in the previous field are discharged first. Next, a preliminary discharge pulse is applied to the X electrode 3 and the W electrode 5, and a cell which has not been discharged in the previous field newly discharges. However, if the discharge characteristics of the cells vary, or if a very long time has elapsed since the preliminary discharge in the previous field, there is a possibility that some cells may not be discharged only by applying the preliminary discharge pulse. Therefore, following the application of the preliminary discharge pulse, the high voltage pulse 14 is applied to the X electrode 3.
The high voltage pulse 14 forcibly discharges cells that have not been discharged only by the preliminary discharge pulse 13 to the W electrode 5, so that preliminary discharge can be reliably generated in all cells. Further, in the high-voltage pulse 14, only the cells that have not been discharged by the preliminary discharge pulse are discharged, so that the display contrast is not significantly deteriorated. The voltage of the high-voltage pulse is considered to be, for example, 1.5 to 2 times Vs as a necessary and sufficient value for reliably generating a discharge.
In the third embodiment as well, pulses may be connected by broken lines as shown in FIG.
[0054]
According to this embodiment, after applying the preliminary discharge pulse 13 to the W electrode 5 and applying the high voltage pulse 14 to the X electrode 3, the preliminary discharge can be surely performed in all cells without greatly deteriorating the display contrast. Discharge can occur.
[0055]
Embodiment 4. FIG.
In the third embodiment, after applying the pre-discharge pulse to the W electrode, the discharge occurs in all the cells to which the high voltage pulse is applied to the X electrode. In the fourth embodiment, the waveform of the high voltage pulse is blunted. Thus, the contrast is kept higher than that of the third embodiment by discharging with the minimum voltage that can be discharged.
[0056]
Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a driving waveform diagram of the PDP according to this embodiment.
As shown in FIG. 7, after applying the preliminary discharge pulse 13 to the W electrode 5, a high voltage pulse 14 is applied to the X electrode 3, and this waveform has a dull shape in which the voltage gradually increases. The rise time of this blunt waveform is several μs to several hundred μs. Since the cells that have not been discharged by the preliminary discharge pulse are discharged at the minimum dischargeable voltage by dulling the waveform in this manner, the contrast can be kept higher than in the third embodiment.
Since a blunting pulse is applied to the X electrode 3 after the potential of Vs is once applied, there is no possibility of erasing discharge due to the blunting waveform.
In the fourth embodiment as well, pulses may be connected as shown by a broken line in FIG.
[0057]
According to this embodiment, the waveform of the high-voltage pulse 14 applied to the X electrode 3 is blunted, so that all the cells can be discharged, and the contrast can be kept higher than in the third embodiment.
[0058]
Embodiment 5 FIG.
In order to maintain a higher contrast, the preliminary discharge shown in Example 4 is not performed continuously, but the preliminary discharge is thinned out in a range where the effect of the preliminary discharge continues.
Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a driving waveform diagram of the PDP according to this embodiment, and FIG. 9 is a sequence diagram.
In FIG. 9, 15 is a writing / sustaining period, 16 is a preliminary discharging / erasing period, and 17 is an erasing period.
As shown in FIGS. 8 and 9, in the subfield gradation method, the preliminary discharge shown in the fourth embodiment is performed every other field, and the effect of the preliminary discharge is larger than the length of one subfield. In the case of a long duration, the contrast can be kept higher by thinning out the preliminary discharge in this way.
[0059]
Embodiment 6 FIG.
In the fifth embodiment, the preliminary discharge shown in the fourth embodiment is performed every other field. However, as shown in the driving waveform diagram of FIG. 10, the preliminary discharge shown in the first embodiment and the fourth embodiment are performed. It is needless to say that the intended purpose can be achieved also by the method of alternately performing the preliminary discharge including the high voltage pulse described in (1).
[0060]
Embodiment 7 FIG.
In the fifth embodiment, the preliminary discharge is performed every other subfield. However, as shown in the driving sequence of FIG. 11, the effect of the preliminary discharge in the previous subfield remains strong in the subfield having a short period. , The frequency of preliminary discharge is reduced. Conversely, after the long subfield, the effect of the preliminary discharge in the previous subfield is weak, so that the preliminary discharge is not reduced much.
In this manner, one preliminary discharge can be used efficiently, and stable writing can be performed with the minimum frequency of the preliminary discharge.
[0061]
Embodiment 8 FIG.
Further, in the drive sequence shown in FIG. 12, this is improved, the order is changed so that short subfields and long subfields are alternated, and preliminary discharge is caused to occur on average in one field.
In this way, one preliminary discharge can be used efficiently, and more stable writing can be performed with the minimum frequency of the preliminary discharge.
[0062]
【The invention's effect】
The driving method of the plasma display panel according to the present invention starts the precedent discharge only in the cell that has performed the sustain discharge in the previous subfield, and then performs the sustain discharge in the previous subfield. Since the preliminary discharge for starting the discharge is performed only in the cell that has not been discharged, the preliminary discharge can be reliably generated even in the cell in which the sustain discharge has not been performed in the previous subfield.
[Brief description of the drawings]
FIG. 1 is a sectional view of a cell of a plasma display panel according to Embodiment 1 of the present invention.
FIG. 2 is a configuration diagram of a plasma display panel according to Embodiment 1 of the present invention.
FIG. 3 is a driving waveform diagram of the plasma display panel according to the first embodiment of the present invention.
FIG. 4 is a sectional view of a cell of the plasma display panel according to Embodiment 1 of the present invention.
FIG. 5 is a driving waveform diagram of a plasma display panel according to Embodiment 2 of the present invention.
FIG. 6 is a driving waveform diagram of a plasma display panel according to Embodiment 3 of the present invention.
FIG. 7 is a driving waveform diagram of a plasma display panel according to Embodiment 4 of the present invention.
FIG. 8 is a driving waveform diagram of a plasma display panel according to Embodiment 5 of the present invention.
FIG. 9 is a sequence diagram of a plasma display panel according to Embodiment 5 of the present invention.
FIG. 10 is a driving waveform diagram of a plasma display panel according to Embodiment 6 of the present invention.
FIG. 11 is a sequence diagram of a plasma display panel according to Embodiment 7 of the present invention.
FIG. 12 is a sequence diagram of a plasma display panel according to Embodiment 8 of the present invention.
FIG. 13 is a configuration diagram of a conventional plasma display panel.
FIG. 14 is a cross-sectional view of a conventional plasma display panel.
FIG. 15 is a driving waveform diagram of a conventional plasma display panel.
[Explanation of symbols]
3 X electrode, 4 Y electrode, 5 W electrode, 8 cells, 13 preliminary discharge pulse, 14 high voltage preliminary discharge pulse.

Claims (5)

One field is composed of a plurality of subfields, and a preliminary discharge and a sustain discharge are performed during the field period when driving an AC type plasma display panel including a plurality of cells that display multiple gradations by a combination of the subfields. In the driving method,
The preliminary discharge is
Out of the plurality of cells , only the cell that has been performing the sustain discharge in the previous subfield is allowed to start discharging in advance,
A method for driving a plasma display panel, comprising: starting discharge only in cells in which the sustain discharge has not been performed in the previous subfield. One field is composed of a plurality of subfields, and a preliminary discharge and a sustain discharge are performed during the field period when driving an AC type plasma display panel including a plurality of cells that display multiple gradations by a combination of the subfields. In the driving method,
The preliminary discharge is
Of the plurality of cells, the cells that have performed the sustain discharge in the previous subfield and the cells that have not performed the sustain discharge in the previous subfield are performed under different conditions,
The voltage applied to generate the preliminary discharge is
Out of the plurality of cells, the cell that did not perform the sustain discharge in the previous subfield is higher than the cell that performed the sustain discharge in the previous subfield.
A method for driving a plasma display panel, comprising: AC type plasma display panel
3. The driving method for a plasma display panel according to claim 1, further comprising a pair of sustain electrodes arranged in parallel and a write electrode arranged in a direction orthogonal to the pair of sustain electrodes. One field is composed of a plurality of subfields, and when driving an AC-type plasma display panel including a plurality of cells that display multiple gradations by a combination of the subfields, preliminary discharge and sustain discharge are performed during the field period. In the driving method,
The preliminary discharge is
Of the plurality of cells, the cells that have performed the sustain discharge in the previous subfield and the cells that have not performed the sustain discharge in the previous subfield are performed under different conditions,
AC type plasma display panel
Having a pair of sustain electrodes arranged in parallel, and a write electrode arranged in a direction orthogonal to the pair of sustain electrodes,
The voltage applied to generate the preliminary discharge in the cells that did not perform the sustain discharge in the previous subfield is:
1.5 to 2 times the voltage applied to generate the preliminary discharge in the cell that was performing the sustain discharge in the previous subfield
A method for driving a plasma display panel, comprising: The waveform of the voltage applied to generate the preliminary discharge in the cell that did not perform the sustain discharge in the previous subfield is:
The driving method of the plasma display panel of claim 2 or 4, wherein the rise time is dull waveform is several μs~ several hundred .mu.s.

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