JP4337306B2 - Driving method of plasma display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving method of a plasma display used for image display of a television and a computer.
[0002]
[Prior art]
The plasma display panel is configured by disposing a front substrate on which a display electrode pair including scan electrodes and sustain electrodes is formed and a rear substrate on which a data electrode is formed so that the display electrode pair and the data electrode intersect with each other. A discharge cell is formed at each intersection of the display electrode pair and the data electrode. Image display is performed by applying a drive voltage to each of the scan electrode, the sustain electrode, and the data electrode in an initialization period, a write period, a sustain period, and an erase period.
[0003]
First, in the initialization period, an initialization pulse is applied to all the scan electrodes, and initialization discharge is performed in all the discharge cells. In the next writing period, the scanning pulse is sequentially applied to the scanning electrode and the writing pulse is applied to the data electrode according to the display data, thereby crossing the scanning electrode to which the scanning pulse is applied and the data electrode to which the writing pulse is applied. Write discharge is caused in the discharge cells of the part, and display data is written. In the next sustain period, an image display is performed by applying a sustain pulse alternately to the scan electrodes and the sustain electrodes and generating a display discharge in the discharge cells in which the display data is written. In the next erasing period, an erasing pulse is applied to the sustain electrode to end the sustain discharge.
[0004]
Such an initialization period, writing period, sustain period, and erase period constitute one subfield and a plurality of subfields constitute one field. By changing the number of sustain pulses in each subfield, the subfield The gradation display is performed by changing the light emission luminance of the field and selecting the subfield to emit light in the writing period.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a driving method of a plasma display capable of performing high-quality display in such a plasma display panel.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises a plurality of row electrodes including scan electrodes and sustain electrodes, and a plurality of column electrodes arranged so as to intersect the row electrodes. A driving method of a plasma display in which a plurality of discharge cells are formed in a region intersecting with an electrode, wherein one field is composed of a plurality of subfields, and wall charges are applied to the discharge cells in accordance with display data in each subfield. And a sustain period in which a sustain discharge is generated in the discharge cells in which the wall charges are formed. In the write period, the scan electrode of each row has a scan pulse and data is transferred to the column electrode at the same timing as the scan pulse. when performing the scanning by applying a write pulse for writing, scanning electrodes for scanning continues not in the line next to In addition, the scan pulses applied to the scan electrodes to be continuously scanned are temporally overlapped, and among the scan electrodes to be continuously scanned, the scan electrode to be scanned first is set as the scan electrode SCNa, and the scan is performed later. When the scan electrode is the scan electrode SCNb and the scan electrode to be scanned thereafter is the scan electrode SCNc, the write discharge current does not flow through the scan electrode SCNa and the write discharge current flows through the scan electrode SCNb. During this period, a scan pulse is applied to the scan electrode SCNc, and the scan pulse applied to the scan electrode SCNb is terminated before the writing discharge current starts to flow to the scan electrode SCNc .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0008]
First, the configuration of the plasma display panel will be described with reference to FIG. 1 which is a perspective view showing the main part. As shown in FIG. 1, a plurality of scan electrodes 3 and sustain electrodes 4 covered with a dielectric layer 2 are provided in pairs on a first substrate 1, and a protective layer 5 is provided on the dielectric layer 2. Is forming. A plurality of data electrodes 8 covered with an overcoat layer 7 are provided on the second substrate 6, and a partition wall 9 parallel to the data electrodes 8 is provided so as to be positioned between the data electrodes 8 on the overcoat layer 7. Furthermore, a phosphor layer 10 is provided on the surfaces of the overcoat layer 7 and the barrier ribs 9. The first substrate 1 and the second substrate 6 are arranged to face each other so that the scan electrode 3 and the sustain electrode 4 and the data electrode 8 are orthogonal to each other, and a discharge space 11 is formed between the substrates. . In FIG. 1, the first substrate 1 and the second substrate 6 are shown separated from each other, and actually, the top of the partition wall 9 and the surface of the protective layer 5 are substantially in contact with each other. In FIG. 1, adjacent scan electrode 3 and sustain electrode 4 form a pair, and a discharge cell is formed at the intersection of scan electrode 3 and sustain electrode 4 and data electrode 8 forming a pair. Display is performed by sustain discharge between the scan electrode 3 and the sustain electrode 4 in the cell.
[0009]
As shown in FIG. 2, this plasma display panel has an M × N matrix structure, and N columns of data electrodes (column electrodes) D _{1 to} D _N are arranged in the column direction. In the direction, row electrodes including M rows of scan electrodes SCN _{1 to} SCN _M and sustain electrodes SUS _{1 to} SUS _M are arranged.
[0010]
A method of driving a plasma display according to an embodiment of the present invention for displaying an image on the plasma display panel having such a configuration will be described with reference to the drawings.
[0011]
FIG. 3 is a configuration diagram showing a subfield configuration in one field (1/60 second) that is a display period of one screen. Here, an example in which one field is configured by eight subfields SF1 to SF8 is shown. . Unlike each display light emission luminance of each subfield, eight subfields SF1, SF2, · ·, respectively 2 ⁰ weighting of the display light emission luminance of SF8, 2 ^1, · ·, 2 by 2 ^{7 8} = 256 gray scale display can be performed. A subfield SF1 arranged at the beginning of one field is composed of an initializing period, a writing period, a sustaining period and an erasing period, and subfields SF2 to SF8 are composed of a writing period, a sustaining period and an erasing period, respectively. Yes.
[0012]
FIG. 4 is an operation drive timing chart in the subfield SF1, and shows drive voltage waveforms applied to the respective electrodes. First, in the initialization period, when the initialization waveform Aic is applied to all the scan electrodes SCN _{1 to} SCN _M and the initialization waveform Aiu is applied to all the sustain electrodes SUS _{1 to} SUS _M , the initialization discharge is generated in all the discharge cells. Regardless of the wall charge state in the previous subfield, the wall charge state is reset in all the discharge cells, and the wall charge is generated to generate the write discharge in the next write period at a low voltage.
[0013]
In the writing period after the initialization period, all the sustain electrodes SUS _{1 to} SUS _M are held at Vh (V), and all the scan electrodes SCN _{1 to} SCN _M are held at 0 (V). Then, when scanning the first line, the first line of the predetermined data electrode D _i for writing data among the data electrodes D ₁ to D _N applied with a negative scan pulse As the scanning electrode SCN ₁ (i Is applied to the discharge cell at the intersection of the scan electrode SCN ₁ and the predetermined data electrode D _i, and the scan electrode SCN is generated in the discharge cell. Positive wall charges are accumulated on the surface of the protective layer 5 on ₁ .
[0014]
Next, the scanning pulse As a write pulse time prior application only time t from time to end the Aw of when scanning the scan electrodes SCN ₁ in the first row, negative scan to scan electrodes SCN ₃ in the third row by applying a positive write pulse Aw to a predetermined data electrode D _i is applied with a pulse as, address discharge occurs in the discharge cells at the intersections between the scanning electrode SCN ₃ predetermined data electrode D _i, the discharge In the cell, positive wall charges are accumulated on the surface of protective layer 5 on scan electrode SCN ₃ . That is, scan pulse As applied to scan electrode SCN ₁ in the first row and scan pulse As applied to scan electrode SCN ₃ in the third row overlap in time. Hereafter, time t is referred to as overlap time.
[0015]
After scanning the third line, scan the odd lines (M is an even number) in order, such as the fifth line, the seventh line,..., The (M-1) line, and then the second line. The fourth line,..., The Mth even-numbered line are scanned in order. That is, the scanning is performed so that the scanning electrode to be continuously scanned does not exist in the adjacent row, and so-called interlaced scanning is performed. As for the timing of applying the scan pulse, the scan pulse is applied to each of the two scan electrodes to be continuously scanned in the same manner as the scan pulse As applied to the scan electrodes SCN ₁ and SCN ₃ of the first and third rows. The scanning pulses As to be overlapped with each other for the overlap time t.
[0016]
As described above, scanning is performed by applying the scanning pulse As to the scanning electrodes SCN _{1 to} SCN _M of all rows, and wall charges are formed in predetermined discharge cells in accordance with display data in the writing period. .
[0017]
In the sustain period after the writing period, a positive sustain pulse Am is alternately applied to all the scan electrodes SCN _{1 to} SCN _M and all the sustain electrodes SUS _{1 to} SUS _M , so that the wall charges according to the display data. Sustain discharge is continuously performed in the discharge cell in which is formed. Light emission by this sustain discharge is used for display.
[0018]
In the erasing period after the sustaining period, the erasing waveform Aec is applied to all of the scan electrodes SCN _{1 to} SCN _M and the erasing waveform Aeu is applied to all of the sustaining electrodes SUS _{1 to} SUS _M , thereby maintaining the sustain discharge in the sustaining period In the discharge cell in which the occurrence of this occurs, the wall discharge in the same state as that at the end of the initialization period is formed by stopping the sustain discharge and generating a weak discharge. In the discharge cells in which neither the address discharge nor the sustain discharge has been performed, no discharge occurs during this erasing period, and the wall charge state is maintained at the end of the initialization period. That is, at the end of subfield SF1, wall charges in the same state as at the end of the initializing period are formed in all the discharge cells.
[0019]
As described above, the subfield SF1 includes the initializing period for generating the initializing discharge in all the discharge cells, the writing period for forming wall charges in the discharge cells according to the display data, and the display data in the writing period. The discharge cell in which the corresponding wall charges are formed is composed of a sustain period for generating a sustain discharge and an erasing period for stopping the sustain discharge. In addition, the drive voltage waveform applied to each electrode in the writing period, the sustain period, and the erasing period constituting each of the subfields SF2 to SF8 is the same as the drive voltage waveform in each period in the subfield SF1, and the subfield SF2 At the end of each of .about.SF8, wall charges in the same state as at the end of the initialization period are formed in all the discharge cells. Since the display light emission luminance of the subfield is proportional to the number of repetitions of sustain pulse Am in the sustain period, the number of repetitions of sustain pulse Am is changed in each subfield in accordance with the weighting of the display light emission luminance.
[0020]
Next, the overlap time t will be described with reference to FIG. 5, when scanning the first line, the scanning pulse As applied in the first row to the scan electrodes SCN _1, scan electrode current flowing through the write pulse Aw and the scanning electrodes SCN ₁ is applied to a predetermined data electrode D _i and each waveform of I _SCN1, when scanning the third row, the scan pulse as applied to scan electrode SCN ₃ in the third row, flows to the write pulse Aw and the scanning electrode SCN ₃ is applied to a predetermined data electrode D _i Each waveform of the scan electrode current I _SCN3 is shown. Here, the time when the scan pulse As is applied to the scan electrode SCN ₁ in the first row is shown as 0, and the pulse widths of the scan pulse As and the write pulse Aw are shown as Tp.
[0021]
When the scanning electrode current I _SCN1 flowing through the scanning electrodes SCN ₁ will be described as an example, a current Ic that charges the capacitance of the scanning electrodes SCN ₁ immediately after the application start time 0 of the scan pulse As applied to scan electrodes SCN ₁ to flow Thereafter, the current (address discharge current) Id due to the address discharge starts to flow from time Ts due to discharge delay, and stops flowing at time Te. Then, current Ie discharges the capacitance of the scanning electrodes SCN ₁ immediately before the application end time Tp of the scanning pulse As applied to scan electrodes SCN ₁ flows.
[0022]
As shown in FIG. 5, before the write discharge is started by the scan of the third row and the write discharge current Id starts to flow to the scan electrode SCN ₃ , the scan pulse As is applied to the scan electrode SCN ₁ of the first row. time t overlap as application of the write pulse Aw to a predetermined data electrode D _i is completed is set (t <Ts). Therefore, the write discharge is not generated by the write pulse Aw applied by the first row scan and the scan pulse As applied by the third row scan. Further, in the scanning of the first row, after the writing discharge is finished and the writing discharge current Id stops flowing at the time Te, after a time tc with a further margin, the application of the scanning pulse As to the scanning electrode SCN ₁ and the predetermined time are performed. Since the application of the write pulse Aw to the data electrode D _i is set to end, the write discharge is reliably performed.
[0023]
By the way, in the present embodiment, the scanning pulses applied to the scanning electrodes in the writing period are temporally overlapped for the overlap time t and the interlaced scanning is performed, but instead of performing interlaced scanning, the first and second lines are performed. When sequential scanning is performed in which adjacent rows are sequentially scanned like the first,..., And Mth rows, it is difficult to perform normal display. Considering this reason with reference to FIG. 6, when the scan pulses applied to the scan electrodes are overlapped in time by the overlap time t and are sequentially scanned, the write discharge is performed in the discharge cell C1 in the first row. the scanning pulse as is applied to the scanning electrode SCN ₂ while but occurring due to the influence of the applied scan pulses as the scanning electrode SCN _2, the electric charges generated in the address discharge in the discharge cell C1 A part moves toward the discharge cell C2 in the second row. For this reason, if there is no display data in the discharge cell C2 and no write discharge is generated, the wall charge state of the discharge cell C2 changes from the state at the end of the initialization period. Therefore, for example, when the scan pulse is applied to the scan electrodes so that the scan pulses overlap in time in the write period of the subfield SF1, and the sequential scan is performed, a desired write discharge occurs in the next subfield SF2. It is considered that normal display cannot be performed.
[0024]
Therefore, in the present invention, the scanning pulse is applied to the scanning electrode so that the scanning pulses overlap in time, and the interlaced scanning is performed. If the drive voltage waveform shown in FIG. 4, for example, the scanning pulse As the scanning electrode SCN ₃ while the address discharge in the first row of discharge cells C1 is generated is applied, the scanning electrode SCN ₃ discharge Since it is located away from the cell C1, there is no problem with the sequential scanning as described above, and normal display can be performed. In addition, the occurrence of an erroneous discharge in the discharge cells in the third row due to the discharge of the address discharge in the discharge cells C1 in the first row is suppressed.
[0025]
Further, in the driving method of the present invention, since the scanning pulse As is overlapped for the overlap time t, the time of the writing period is Tp × M−t × (M−1), as compared with the case where the overlap time t is not provided. The time of the writing period is shortened by t × (M−1). Therefore, if the time of the writing period is set to be the same as the case where the overlap time t is not provided, the number of panel rows can be increased. That is, when a = (Tp × M−t) / (Tp−t) and K is the maximum integer that does not exceed a, the number of lines on the panel can be increased from M lines to K lines.
[0026]
For example, when the discharge characteristics of the write discharge are measured in a prototype 42-inch plasma display panel, the discharge delay time Ts from the start of application of the scan pulse As and the write pulse Aw to the start of the write discharge is 0.7 μsec minimum ( Ts = 0.7 μsec), and the maximum time Te until the end of the writing discharge was 2.2 μsec (Te = 2.2 μsec). Here, assuming that the margin time tc = 0.31 μsec and the pulse width (application time) Tp of the scanning pulse As and write pulse Aw is Tp = Te + tc = 2.51 μsec, one field is composed of eight subfields. Thus, in order to display 2 ⁸ = 256 gradations, when the overlap time t is not provided, for example, it is limited to drive a panel having 480 rows. On the other hand, in the present invention, when the overlap time t = 0.51 μsec (<Ts), a = (Tp × M−t) / (Tp−t) = (2.51 × 480−0.51). ) / (2.51-0.51) = 602.145, it is possible to drive a panel having up to 602 rows, and a high-quality plasma display can be obtained.
[0027]
Further, the initializing discharge in the initializing period is generated even in a so-called black screen display in which there are no discharge cells to be displayed on the panel. Since the initializing discharge emits light, the initializing discharge is small. As a result, the visibility of black display is improved. In the present embodiment, since the initialization period for generating the initialization discharge is provided only in the subfield SF1, the black display is excellent in visibility and an extremely high value of contrast can be obtained.
[0028]
In the above embodiment, the case where the initialization period is provided in one subfield in one field has been described. However, the present invention is not limited to such a case. That is, the present invention is also applied to a case where one field is constituted by at least one subfield consisting of an initialization period, a writing period, a sustaining period and an erasing period and a plurality of subfields consisting of a writing period, a sustaining period and an erasing period. Can be implemented. Further, when scanning of the scanning electrodes is performed in the writing period, the scanning is not limited to that shown in FIG. 4, and the scanning is continuously performed, for example, the first row, the fourth row, the seventh row,. It suffices that the scan electrode does not exist in the adjacent row.
[0029]
【The invention's effect】
As described above, according to the plasma display driving method of the present invention, it is possible to obtain a plasma display capable of high-quality display.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a main part of a plasma display panel according to an embodiment of the present invention. FIG. 2 is an electrode array diagram of the plasma display panel. FIG. 4 is a configuration diagram showing a field configuration. FIG. 4 is an operation drive timing diagram in the subfield SF1 according to the embodiment of the invention. FIG. 5 is a diagram illustrating write pulses, scan pulses, and scan electrode currents according to the embodiment of the invention. FIG. 6 is a schematic configuration diagram of a discharge cell according to an embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 1st board | substrate 3 Scan electrode 4 Sustain electrode 6 2nd board | substrate 8 Data electrode

Claims (2)

A plurality of row electrodes including scan electrodes and sustain electrodes are arranged, and a plurality of column electrodes are arranged so as to intersect the row electrodes, and a plurality of discharge cells are provided in a region where the row electrodes and the column electrodes intersect. A driving method of the formed plasma display, wherein one field is composed of a plurality of subfields, and in each subfield, a writing period for forming wall charges in the discharge cells according to display data and the wall charges are formed. And a sustain period for generating a sustain discharge in the discharge cell, and scanning is performed by applying a scan pulse and a write pulse for writing data to the column electrode at the same timing as the scan pulse in the write period in the write period. When performing scanning, make sure that the scanning electrode to be continuously scanned does not exist in the adjacent row, and to continue scanning. The scan pulses applied to each of the electrodes are overlapped in time, and among the scan electrodes to be continuously scanned, the scan electrode to be scanned first is the scan electrode SCNa, the scan electrode to be scanned later is the scan electrode SCNb, and When the scan electrode to be scanned thereafter is the scan electrode SCNc, the scan electrode SCNc is scanned while the write discharge current is not flowing through the scan electrode SCNa and the write discharge current is flowing through the scan electrode SCNb. A method for driving a plasma display , comprising: applying a pulse and ending a scan pulse applied to the scan electrode SCNb before a write discharge current starts to flow to the scan electrode SCNc .   An initializing period for generating an initializing discharge in all the discharge cells, an addressing period for forming wall charges in the discharge cells according to display data, a sustaining period for generating sustain discharges in the discharge cells in which the wall charges are formed, and 2. A field according to claim 1, wherein at least one subfield comprising an erasing period for stopping the sustain discharge and a plurality of subfields comprising the writing period, the sustaining period and the erasing period constitute one field. The driving method of the plasma display as described.

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