JP4232400B2 - Driving method of plasma display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method for driving a plasma display, which is known as a large-screen, thin and lightweight display device.
[0002]
[Prior art]
  An example of a plasma display panel (hereinafter referred to as a panel) used in a conventional AC type plasma display is shown in FIG. As shown in FIG. 3, a plurality of scanning electrodes 4 and sustain electrodes 5 covered with a dielectric layer 2 and a protective film 3 form a pair on the first glass substrate 1 on the front side. On the second glass substrate 6 formed in parallel and on the back side, a plurality of data electrodes 8 covered with an insulator layer 7 are formed, and on the insulator layer 7 between the data electrodes 8 A partition wall 9 is provided in parallel with the data electrode 8, and a phosphor 10 is provided from the surface of the insulator layer 7 to the side surface of the partition wall 9. Further, the first glass substrate 1 and the second glass substrate 6 are disposed to face each other with the discharge space 11 therebetween so that the scan electrode 4 and the sustain electrode 5 and the data electrode 8 intersect each other at a substantially right angle. The discharge space 11 is filled with at least one kind of rare gas among helium, neon, argon, and xenon as a discharge gas. A plurality of discharge cells 12 are formed in a discharge space at the intersection of the data electrode 8 and the pair of scan electrode 4 and sustain electrode 5 facing each other, sandwiched between two adjacent barrier ribs 9. .
[0003]
  Next, an electrode array diagram of this panel is shown in FIG. As shown in FIG. 4, the electrode arrangement of this panel has an m × n matrix configuration, m columns of data electrodes D1 to Dm are arranged in the column direction, and n rows of scan electrodes SCN1 in the row direction. -SCNn and sustain electrodes SUS1-SUSn are arranged. Further, the discharge cell 12 shown in FIG. 3 is configured as shown in FIG.
[0004]
  FIG. 5 shows an operation drive timing chart of a drive method for driving the panel. This driving method is for performing gradation display of 256 gradations, and one field period is composed of eight subfields. Hereinafter, a conventional driving method will be described with reference to FIG.
[0005]
  As shown in FIG. 5, each of the first to eighth subfields includes an initialization period, an address period, a sustain period, and an erase period. First, the operation in the first subfield will be described.
[0006]
  As shown in FIG. 5, in the initialization operation in the first half of the setup period, all the data electrodes D1 to Dm and all the sustain electrodes SUS1 to SUSn are held at 0 (V), and all the scan electrodes SCN1 to SCNn are Applies a ramp voltage that gradually rises from a voltage Vp (V) that is equal to or lower than the discharge start voltage to a voltage Vr (V) that exceeds the discharge start voltage, with respect to all the sustain electrodes SUS1 to SUSn. While this ramp voltage rises, the first weak initializing discharge is generated in all the discharge cells 12 from all the scan electrodes SCN1 to SCNn to all the data electrodes D1 to Dm and all the sustain electrodes SUS1 to SUSn. As a result, a negative wall voltage is accumulated on the surface of the protective film 3 on the scan electrodes SCN1 to SCNn, and the surface of the insulating layer 7 on the data electrodes D1 to Dm and the protective film 3 on the sustain electrodes SUS1 to SUSn. A positive wall voltage is accumulated on the surface.
[0007]
  Further, in the initializing operation in the latter half of the initializing period, all the sustain electrodes SUS1 to SUSn are kept at the positive voltage Vh (V), and all the scan electrodes SCN1 to SCNn are connected to all the sustain electrodes SUS1 to SUSn. A ramp voltage that gently falls from a voltage Vq (V) that is equal to or lower than the discharge start voltage to 0 (V) that exceeds the discharge start voltage is applied. While this ramp voltage falls, the second weak initializing discharge occurs again from all sustain electrodes SUS1 to SUSn to all scan electrodes SCN1 to SCNn in all discharge cells 12, and scan electrodes SCN1 to SCNn. The negative wall voltage on the surface of the upper protective film 3 and the positive wall voltage on the surface of the protective film 3 on the sustain electrodes SUS1 to SUSn are weakened. On the other hand, the positive wall voltage on the surface of the insulator layer 7 on the data electrodes D1 to Dm is maintained as it is. This completes the initialization operation in the initialization period.
[0008]
  In the address operation in the next address period, all scan electrodes SCN1 to SCNn are held at Vs (V), and predetermined data corresponding to the discharge cells 12 to be displayed in the first row among the data electrodes D1 to Dm. A positive address pulse voltage + Vw (V) is applied to the electrodes, and a scan pulse voltage 0 (V) is applied to scan electrode SCN1 in the first row. At this time, the voltage between the surface of the insulator layer 7 and the surface of the protective film 3 on the scan electrode SCN1 at the intersection of the predetermined data electrode and the scan electrode SCN1 is set to the write pulse voltage + Vw (V). Since the positive wall voltage of the surface of the insulator layer 7 on D1 to Dm is added, at this intersection, between the predetermined data electrode and the scan electrode SCN1 and the sustain electrode SUS1 and the scan electrode SCN1 Address discharge occurs during this period, a positive voltage is accumulated on the surface of the protective film 3 on the scan electrode SCN1 at this intersection, a negative voltage is accumulated on the surface of the protective film 3 on the sustain electrode SUS1, and data where the address discharge has occurred A negative voltage is accumulated on the surface of the insulator layer 7 on the electrode.
[0009]
  Next, among the data electrodes D1 to Dm, a positive address pulse voltage + Vw (V) is applied to a predetermined data electrode corresponding to the discharge cell 12 to be displayed in the second row, and the scan electrode SCN2 in the second row. A scan pulse voltage 0 (V) is applied. At this time, the voltage between the surface of the insulator layer 7 and the surface of the protective film 3 on the scan electrode SCN2 at the intersection of the predetermined data electrode and the scan electrode SCN2 is set to the write pulse voltage + Vw (V). Since the positive wall voltage of the surface of the insulating layer 7 on the data electrode is added, at this intersection, the predetermined data electrode and the scan electrode SCN2 and between the sustain electrode SUS2 and the scan electrode SCN2 An address discharge occurs in the meantime, and a positive voltage is accumulated on the surface of the protective film 3 on the scan electrode SCN2 at this intersection, and a negative voltage is accumulated on the surface of the protective film 3 on the sustain electrode SUS2.
[0010]
  A similar operation is subsequently performed. Finally, among the data electrodes D1 to Dm, a positive address pulse voltage + Vw (V) is applied to a predetermined data electrode corresponding to the discharge cell 12 to be displayed in the nth row. Scan pulse voltage 0 (V) is applied to scan electrode SCNn in the nth row. At this time, address discharge occurs between the predetermined data electrode and the scan electrode SCNn and between the sustain electrode SUSn and the scan electrode SCNn at the intersection between the predetermined data electrode and the scan electrode SCNn. A positive voltage is accumulated on the surface of the protective film 3 on the electrode SCNn, a negative voltage is accumulated on the surface of the protective film 3 on the sustain electrode SUSn, and a negative voltage is generated on the surface of the insulator layer 7 on the data electrode where the address discharge has occurred. Accumulated. Thus, the writing operation in the writing period is completed.
[0011]
  In the subsequent sustain period, first, all scan electrodes SCN1 to SCNn and sustain electrodes SUS1 to SUSn are once returned to 0 (V), and then positive sustain pulse voltage + Vm (V) is applied to all scan electrode groups SCN1 to SCNn. When applied, the voltage between the protective film 3 on the scan electrodes SCN1 to SCNn and the protective film 3 on the sustain electrodes SUS1 to SUSn in the discharge cell 12 in which the address discharge has occurred is written to the sustain pulse voltage + Vm (V). The positive voltage on the surface of the protective film 3 on the scan electrodes SCN1 to SCNn and the negative voltage on the surface of the protective film 3 on the sustain electrodes SUS1 to SUSn accumulated in the period are added. Therefore, in the discharge cell in which the address discharge has occurred, a sustain discharge occurs between scan electrodes SCN1 to SCNn and sustain electrodes SUS1 to SUSn, and the protective film on scan electrodes SCN1 to SCNn in the discharge cell in which the sustain discharge has occurred A negative voltage is accumulated on the surface 3 and a positive voltage is accumulated on the surface of the protective film 3 on the sustain electrodes SUS1 to SUSn. Thereafter, the sustain pulse voltage returns to 0 (V).
[0012]
  Subsequently, when a positive sustain pulse voltage + Vm (V) is applied to all the sustain electrodes SUS1 to SUSn, the protective film 3 on the sustain electrodes SUS1 to SUSn and the scan electrodes SCN1 to SCNn in the discharge cell 12 in which the sustain discharge has occurred. The voltage between the protective film 3 and the negative voltage on the surface of the protective film 3 on the scan electrodes SCN1 to SCNn and the voltages on the sustain electrodes SUS1 to SUSn are the sustain pulse voltage + Vm (V). The positive voltage on the surface of the protective film 3 is added. For this reason, in the discharge cell in which the sustain discharge has occurred, the sustain discharge occurs between sustain electrodes SUS1 to SUSn and scan electrodes SCN1 to SCNn, whereby surface of protective film 3 on sustain electrodes SUS1 to SUSn in the discharge cell A negative voltage is accumulated in the positive electrode, and a positive voltage is accumulated on the surface of the protective film 3 on the scan electrodes SCN1 to SCNn. Thereafter, the sustain pulse voltage returns to 0 (V).
[0013]
  Similarly, the sustain discharge is continuously performed by alternately applying the positive sustain pulse voltage + Vm (V) to all the scan electrodes SCN1 to SCNn and all the sustain electrodes SUS1 to SUSn. Finally, when a positive sustain pulse voltage + Vm (V) is applied to all scan electrodes SCN1 to SCNn, over protective film 3 and sustain electrodes SUS1 to SUSn on scan electrodes SCN1 to SCNn in discharge cell 12 in which sustain discharge has occurred. The voltage between the protective film 3 and the positive voltage on the surface of the protective film 3 on the scan electrodes SCN1 to SCNn accumulated by the immediately previous sustain discharge and the voltage on the sustain electrodes SUS1 to SUSn are the sustain pulse voltage + Vm (V). The negative voltage on the surface of the protective film 3 is added. For this reason, in the discharge cell in which the sustain discharge has occurred, the sustain discharge occurs between scan electrodes SCN1 to SCNn and sustain electrodes SUS1 to SUSn, whereby surface of protective film 3 on scan electrodes SCN1 to SCNn in the discharge cell A negative voltage is accumulated on the protective film 3, and a positive voltage is accumulated on the surface of the protective film 3 on the sustain electrodes SUS1 to SUSn. Thereafter, the sustain pulse voltage returns to 0 (V). Thus, the maintenance operation for the maintenance period is completed. Visible light emission from the phosphor 10 excited by ultraviolet rays generated by the sustain discharge is used for display.
[0014]
  In the subsequent erasing period, when a ramp voltage that gradually increases from 0 (V) to + Ve (V) is applied to all the sustain electrodes SUS1 to SUSn, the scan electrodes SCN1 to SCNn are generated in the discharge cell 12 in which the sustain discharge has occurred. The voltage between the upper protective film 3 and the protective film 3 on the sustain electrodes SUS1 to SUSn is the negative voltage on the surface of the protective film 3 on the scan electrodes SCN1 to SCNn and the sustain electrodes SUS1 to SUSn at the end of the sustain period. The positive voltage on the surface of the upper protective film 3 is added to the lamp voltage. Therefore, in the discharge cell in which the sustain discharge has occurred, a weak erasure discharge occurs between sustain electrodes SUS1 to SUSn and scan electrodes SCN1 to SCNn, and the negative voltage on the surface of protective film 3 on scan electrodes SCN1 to SCNn is maintained. The positive voltage on the surface of the protective film 3 on the electrodes SUS1 to SUSn is weakened and the sustain discharge is stopped. Thus, the erase operation in the erase period ends.
[0015]
  However, in the above operation, for discharge cells in which display is not performed, initialization discharge occurs in the initialization period, but address discharge, sustain discharge and erasure discharge are not performed, and scan electrodes of discharge cells in which display is not performed The wall voltage of the surface of the protective film 3 of SCN1 to SCNn and the sustain electrodes SUS1 to SUSn and the wall voltage of the surface of the insulator layer 7 on the data electrodes D1 to Dm were kept as they were at the end of the initialization period. It is.
[0016]
  One screen in the first subfield is displayed by all the operations described above. Hereinafter, the same operation is performed from the second subfield to the eighth subfield. The luminance of the discharge cells displayed in these subfields is determined by the number of times of application of the sustain pulse voltage + Vm (V). Therefore, although detailed description is omitted, for example, the number of times of application of the sustain pulse voltage in each subfield is set as appropriate, and eight subfields whose luminance due to sustain discharge is 20, 21, 22,. By configuring with fields, gradation display of 28 = 256 gradations becomes possible.
[0017]
  In the conventional driving method described above, there is no discharge cell to be displayed on the panel. In the so-called black screen display, the address discharge in the address period, the sustain discharge in the sustain period, and the erase discharge in the erase period do not occur. Only the initializing discharge during the resetting period occurs, the initializing discharge is weak, and the discharge light emission is also weak, so that the panel has a high contrast. For example, in a 42 "AC type plasma display panel having a matrix configuration of 480 rows and 852 x 3 columns, when 256 gradation display is performed with one field period constituted by eight subfields, the initial value of each subfield is set. The light emission luminance due to the two initializing discharges during the crystallization period is 0.15 cd / m²Met. Therefore, the sum of the 8 subfields is 0.15 × 8 = 1.2 cd / m²The maximum brightness is 420 cd / m²Therefore, the contrast of this panel is 420 / 1.2: 1 = 350: 1, and a considerably high contrast can be obtained.
[0018]
[Problems to be solved by the invention]
  However, in the conventional driving method described above, a ramp waveform that rises toward the voltage Vr is applied to the scan electrode during the initialization period, and the entire in-panel plane is applied regardless of the presence or absence of the sustain discharge immediately before the initialization period. In these cells, initializing discharge occurs between the scan electrode, the sustain electrode, and the data electrode. Furthermore, since an initializing period is provided for each subfield, an initializing discharge always occurs in every cell for each subfield, and even when light is emitted by a weak initializing discharge when the panel is displayed in a dark place, the light emission is conspicuous. There was a big problem that the brightness became higher and the visibility of black display was worse.
[0019]
  An object of the present invention is to solve such problems and to improve the visibility of black display by reducing the light emission luminance during black display.
[0020]
[Means for Solving the Problems]
  To achieve the above object, the present invention provides a plasma display driving method,Immediately before the writing period of the plurality of subfields,The scan electrode has an initializing waveform having a rising portion having a gradually inclined portion that gradually increases and a falling portion having a gradually inclined portion that gradually decreases to a voltage lower than a voltage at a low level in the sustain period. An initialization period to be applied to, andImmediately before the initialization period of any one of the plurality of subfields,For all discharge cells, a weak discharge is generated between the sustain electrode and the scan electrode so that a negative wall charge is formed on the sustain electrode side and a positive wall charge is formed on the scan electrode side. This is characterized in that a period for the initializing operation for all the cells to occur is provided.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
  That is, according to the first aspect of the present invention, a plurality of data electrodes are arranged so as to intersect with a plurality of pairs of scan electrodes and sustain electrodes, and intersections between the scan electrodes, sustain electrodes, and data electrodes are arranged. And a plasma display panel having a plurality of discharge cells, and one frame is constituted by a plurality of subfields, and a display signal writing period to the discharge cells and discharges in the discharge cells in the subfields. In a driving method of a plasma display having a sustain period in which a high level and a low level repetitive pulse is applied in order to maintainImmediately before the writing period of the plurality of subfields,The scan electrode has an initializing waveform having a rising portion having a gradually inclined portion that gradually increases and a falling portion having a gradually inclined portion that gradually decreases to a voltage lower than a voltage at a low level in the sustain period. An initialization period to be applied to, andImmediately before the initialization period of any one of the plurality of subfields,For all discharge cells, a weak discharge is generated between the sustain electrode and the scan electrode so that a negative wall charge is formed on the sustain electrode side and a positive wall charge is formed on the scan electrode side. A method for driving a plasma display, characterized in that a period of initializing operation for all cells to occur is provided.
[0022]
  The invention according to claim 2 is the invention according to claim 1,The time from the end of the application of the voltage applied to the scan electrode during the all-cell initialization operation to the rising edge of the initialization waveform applied to the scan electrode during the initialization period is 50 μsec or less.It is characterized by that.
[0023]
  The invention according to claim 3 is the invention according to claim 1,The time from the end of the final sustain discharge in the sustain period to the rising portion of the initialization waveform applied to the scan electrode in the initialization period is 50 μsec or less.It is characterized by that.
[0024]
  Hereinafter, a driving method according to an embodiment of the present invention will be specifically described with reference to the drawings. Note that the configuration of the panel and the arrangement state of the electrodes are the same as those of the conventional example, and thus the description thereof is omitted.
[0025]
  FIG. 1 is a driving operation timing chart in one frame in the driving method according to the embodiment of the present invention. For ease of understanding, this figure shows a pair of waveforms of voltages applied to the scan electrodes and sustain electrodes.Scan electrode SCNi, sustain electrode SUSiOnly the voltage waveform applied to is described, but the same voltage waveform is applied to the other electrode pairs.
[0026]
  As shown in FIG. 1, one frame is composed of a plurality of (for example, eight) subfields (only the first subfield and the second subfield are shown in the drawing). Each subfield consists of three periods: an initialization period, an address period, and a sustain period. And the address in the write operation in the write period of each subfieldSpecified by thisDischarge cell to which display signal is writtenOnly during the maintenance period,To maintain discharge in the discharge cellofSustain operation to apply high level and low level repetitive pulsesWill cause the addressed discharge cell to light up,A desired gradation is expressed.
[0027]
  During the initialization period of the first subfield,Sustain electrode is used as the period for initializing all cells A pulse voltage having an amplitude of Ve in the positive direction is applied to the scanning electrode, and a period during which a ramp voltage La1 that falls gradually decreases toward the voltage Va in the negative direction is provided on the scanning electrode side. At this time, the potential difference between the pulse voltage with the positive amplitude Ve applied to the sustain electrode and the ramp voltage La1 falling gradually decreasing toward the negative voltage Va applied to the scan electrode is the discharge voltage. This is set to a voltage exceeding the starting voltage, which causes a weak discharge between the sustain electrode and the scan electrode for all discharge cells of the panel, and a negative wall charge is formed on the sustain electrode side. A positive wall charge is formed on the scanning electrode side..
[0028]
  Since the weak discharge generated at this time emits light by the lamp voltage, the light emission is considerably smaller than the light emission by the pulse voltage during the sustain period. Also, all cell initializationActionThe state of the wall charges accumulated on the sustain electrode and scan electrode side after performing the test is very similar to the state of the wall charge on the sustain electrode and scan electrode after the sustain period of the cell discharged in the sustain period of FIG. Yes.
[0029]
  in this wayWeak discharge due to the ramp voltage La1 falling gradually decreasing toward the voltage Va, The drive waveform of the subsequent initialization period by making the state equal to the wall voltage after the end of the maintenance period,FirstSubfieldEyeIt is possible to apply a waveform similar to the drive waveform in the initialization period following the sustain period other than the above.
[0030]
  the aboveLamp voltage La1By providing a period in which weak discharge occurs between the sustain electrode and the scan electrode for all discharge cells, discharge cells that fail to discharge during one field period or discharge cells whose characteristics vary in the plane of the panel Thus, it is possible to perform initialization and prevent a non-lighting phenomenon and an erroneous discharge phenomenon due to abnormal wall charge accumulation, thereby enabling stable display.
[0031]
  Then initialization periodInBy applying a ramp voltage La2 having a rising portion with a gradual slope that gradually increases toward the voltage Vs to the scan electrode, a weak discharge occurs between the sustain electrode and the scan electrode, exceeding the discharge start voltage, The wall charges accumulated on the sustain electrodes and the scan electrodes are erased. After that, the ramp voltage of the voltage Vh is provided on the sustain electrode side, and a gentle slope portion that gradually decreases toward the voltage Va lower than the voltage at the low level during the sustain period is provided on the scan electrode side.FallingA ramp voltage La3 is applied. At this time, the voltage Va on the scan electrode side is set to the vicinity of the discharge start voltage of the scan electrode and the data electrode, and the voltage Vh on the sustain electrode side is set to a desired voltage near the discharge start voltage between the scan electrode and the sustain electrode. As a result, a normal write operation can be performed in the subsequent write period.
[0032]
  In the initialization period after the second subfield, the ramp voltage La4 gradually increases toward the maximum voltage Vs with the same slope as the ramp voltage La2 used in the first subfield described above and the first subfield. It has a ramp voltage La3 that gradually decreases toward the used voltage Va.
[0033]
  After the second subfield, the state of discharge in the initialization period varies depending on the presence or absence of discharge in the sustain period immediately before initialization. Since the cell discharged in the sustain period has a negative wall voltage on the sustain electrode side and a positive wall voltage on the scan electrode side after the end of the sustain period, the rising ramp voltage La4 rises on the scan electrode side in the subsequent initialization period. Is applied to the scan electrode, a weak discharge occurs exceeding the discharge start voltage between the scan electrode and the sustain electrode, and the positive wall voltage on the sustain electrode side and the negative wall voltage on the scan electrode side are reduced. The discharge at the rising ramp voltage La4 is a weak discharge, and this weak discharge is discharged in an initializing period in which only the cells discharged in the sustain period last. The light emission due to the weak discharge is added to the sustain light emission. It does not worsen the black visibility.
[0034]
  Next, as in the initializing period of the first subfield, a ramp voltage of voltage Vh is applied to the sustain electrode side, and a ramp voltage La3 that gradually decreases toward Va is applied to the scan electrode side. At this time, the voltage Va on the scan electrode side is such that the voltage between the scan electrode and the sustain electrode is close to the discharge start voltage, and the voltage Vh on the sustain electrode side is close to the discharge start voltage between the scan electrode and the sustain electrode. By setting to a desired voltage, a normal write operation can be performed in the subsequent write period.
[0035]
  In addition, since the wall voltage on the scan electrode and the sustain electrode after the end of the sustain period of the cell that was not discharged in the sustain period is maintained in the state after the end of the previous initialization period, and the wall voltage is near 0, No discharge occurs at the rising ramp voltage La4 in the initialization period.
[0036]
  The final voltage Vs of the rising ramp in the initialization period, but the cells that did not discharge in the immediately preceding sustain period are not discharged in this rising ramp voltage La4, and are weaker than the cells that were discharged in the immediately preceding sustain period. It is set to a voltage that causes discharge, and for example, a voltage range of Vm ≦ Vs ≦ Vm + 50 is desirable.
[0037]
  Next, as in the initializing period of the first subfield, a ramp voltage of voltage Vh is applied to the sustain electrode side, and a ramp voltage La3 that gradually decreases toward Va is applied to the scan electrode side. At this time, the voltage Va on the scan electrode side is such that the voltage between the scan electrode and the sustain electrode is close to the discharge start voltage, and the voltage Vh on the sustain electrode side is close to the discharge start voltage between the scan electrode and the sustain electrode. By setting to a desired voltage, a normal write operation can be performed in the subsequent write period.
[0038]
  In this way, the discharge was performed within the sustain period by adding the drive waveform as shown in FIG.Discharge cellHowever, by performing the initialization operation in the subsequent initialization period, it is possible to cause normal address discharge without adding all cell initialization to each subfield as in the conventional example, and all cells in each subfield. Initialization is omitted.
[0039]
  FIG. 2 shows a relationship between the time from the end of the lamp voltage La1 to the application of the lamp voltage La2 and the maximum voltage Vs. The maximum voltage Vs is a voltage necessary for causing the discharge target cell to cause a weak discharge at the lamp voltage La2 and causing the discharge without erroneous discharge. If this Vs is too low, the weak discharge at the lamp voltage La2 is not normally performed, and problems such as erroneous lighting and defective lighting occur in the subsequent writing and sustain period.
[0040]
  As shown in FIG. 2, the voltage Vs required for the lamp voltage La2 can be lowered by setting the time T1 from the end of the lamp voltage La1 to the rise of the lamp voltage La2 to 50 μsec or less. In response to the priming of the weak discharge generated at the time of the lamp voltage La1, it is easy to discharge the erasing discharge at the lamp voltage La2, and the maximum voltage Vs can be set low.
[0041]
  Similarly, in the maintenance periodFrom the end of the final sustain discharge by the sustain pulse, the initialization waveform applied to the scan electrode during the initialization periodEven during the time T2 up to the rising ramp voltage La4, by setting it to 50 μsec or less, the erasing discharge at the lamp voltage La4 can be easily discharged, the maximum voltage Vs can be reduced, and stable discharge can be performed at the same time.
[0042]
  As described above, according to the driving method of the present invention, all-cell initialization is performed.ActionIs performed only in the first subfield, and in the second and subsequent subfields, only the cells that are addressed and lighted in the sustain operation are initialized. Therefore, the black luminance level can be lowered. For example, in a 42-inch PDP having a matrix configuration of 480 rows and 852 × 3 columns, when one TV field is configured by eight subfields, the maximum luminance is 420 cd / m.²In contrast, the luminance of the initializing discharge in the initializing period of the first subfield is 0.1 cd / m.²Thus, the black luminance can be greatly reduced as compared with the conventional example. As a result, the contrast of the panel is 420 / 0.1: 1 = 4200: 1, and a very high contrast is realized.
[0043]
  In the above description, all cells are initialized within the initialization period of the first subfield.ActionHowever, not limited to this, all cells are initializedActionMay be provided during the initialization period after the second subfield.
[0044]
【The invention's effect】
  As described above, according to the driving method of the present invention, since the useless process of performing the initialization process is not performed on the discharge cells that are not lit, the effect of reducing the level of black luminance can be obtained. .
[Brief description of the drawings]
FIG. 1 is a driving operation timing chart in a driving method of a plasma display according to an embodiment of the present invention.
FIG. 2 is a graph showing a relationship between a time T1 from the end of application of the lamp voltage La1 to the application of the lamp voltage La2 and the maximum voltage Vs necessary for lamp discharge.
FIG. 3 is a perspective view showing a configuration of a plasma display panel.
FIG. 4 is an explanatory diagram showing an electrode arrangement of the plasma display panel
FIG. 5 is a driving operation timing chart in the conventional driving method.
[Explanation of symbols]
  SCN1-SCNn Scan electrode
  SUS1-SUSn sustain electrode
  D1-Dm Data electrode
  La1, La2, La3, La4 Lamp voltage
  1, 6 Glass substrate
  2 Dielectric layer
  3 Protective film
  4 Scanning electrodes
  5 Maintenance electrode
  7 Insulator layer
  8 Data electrode
  9 Bulkhead
  10 Phosphor
  11 Discharge space
  12 Discharge cell

Claims (3)

A plasma display panel having a plurality of data electrodes arranged so as to intersect a plurality of pairs of scan electrodes and sustain electrodes, and having a plurality of discharge cells at intersections of the scan electrodes, sustain electrodes and data electrodes In addition, one frame is composed of a plurality of subfields, and a high-level and low-level repetitive pulse is applied to the subfields in order to maintain a display signal writing period to the discharge cells and discharge in the discharge cells. In the method for driving a plasma display having a sustain period, a rising portion having a gradually increasing slope immediately before an address period of the plurality of subfields , and a voltage lower than a voltage at a low level in the sustain period An initialization waveform having a falling portion with a gradually inclined portion that gradually decreases An initialization period for applying the serial scan electrodes provided, and immediately before the initializing period of one of sub-fields of the plurality of sub-fields, as for all the discharge cells, negative wall to the sustain electrode side A period of an all-cell initializing operation that causes a weak discharge between the sustain electrode and the scan electrode is provided so that a charge is formed and a positive wall charge is formed on the scan electrode side. Driving method of plasma display.   The time from the end of the application of the voltage applied to the scan electrode during the all-cell initializing operation to the rising portion of the initializing waveform applied to the scan electrode during the initializing period is 50 μsec or less. The method for driving a plasma display according to claim 1.   2. The method for driving a plasma display according to claim 1, wherein the time from the end of the final sustain discharge in the sustain period to the rising portion of the initialization waveform applied to the scan electrode in the initialization period is 50 μsec or less. .

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