JP2000242224A - Method for driving ac type plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an AC type plasma display panel driving method capable of drastically improving the visibility of black and contrast. SOLUTION: One field period is composed of a 1st to 8th sub-fields containing an initializing period, a writing period, and a maintaining period. By making a low level value (Vt(V)) of a maintaining pulse voltage applied to maintaining electrodes SUS1-SUSn for a maintaining period to a higher potential than a low level value (0(V)) of a scanning pulse voltage to be applied to scanning electrodes SCN1-SCNn for a write period, a part of an initializing operation during an initializing period of each sub-field is made to operate at the same time as a maintaining operation during a maintaining period of the immediately preceding sub-field in the 2nd to 8th sub-fields.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving an AC type plasma display panel used for displaying an image on a television receiver or a computer terminal.

[0002]

2. Description of the Related Art FIG. 3 is a partial perspective view of a conventional AC plasma display panel (hereinafter referred to as a panel).
As shown in FIG. 3, a scan electrode 4 and a sustain electrode 5 covered with a dielectric layer 2 and a protective film 3 are provided in parallel on a first glass substrate 1 in pairs. A plurality of data electrodes 8 covered with an insulator layer 7 are provided on the second glass substrate 6, and the insulator layer 7 between each of the data electrodes 8 is provided.
On the upper side, a partition 9 is provided in parallel with the data electrode 8. Further, phosphors 10 are formed on the surface of the insulator layer 7 and on both side surfaces of the partition 9. The first glass substrate 1 and the second glass substrate 6 are arranged to face each other with the discharge space 11 interposed therebetween so that the scanning electrodes 4 and the sustaining electrodes 5 are orthogonal to the data electrodes 8. The discharge space 11 is filled with xenon and at least one of helium, neon, and argon as a discharge gas. A discharge cell 12 is formed in a discharge space at an intersection of the scan electrode 4 and the sustain electrode 5 which form a pair with the data electrode 8.

Next, FIG. 4 shows an electrode arrangement diagram of this panel. As shown in FIG. 4, the electrode arrangement of this panel is m × n
And m columns of data electrodes D _{1 to} D _m are arranged in the column direction, and n rows of scan electrodes SCN _{1 to} SCN _n and sustain electrodes SUS _{1 to} SUS _n are arranged in the row direction. Have been. Also, the discharge cell 12 shown in FIG.
Are provided in a region as shown in FIG.

FIG. 5 shows an operation drive timing chart of a conventional drive method for driving this panel. This driving method is for performing 256 gradation display, and one field period is composed of eight subfields.
Hereinafter, a conventional panel driving method will be described with reference to FIGS.
This will be described with reference to FIG.

[0005] As shown in FIG. 5, the first to eighth subfields are each composed of an initialization period, a writing period, a sustaining period and an erasing period. First, the operation in the first subfield will be described.

As shown in FIG. 5, in the initializing operation in the first half of the initializing period, all data electrodes D _{1 to} D _m and all sustain electrodes SUS _{1 to} SUS _n are held at 0 (V), Scan electrodes SCN _{1 to} SCN _n have all sustain electrodes S
US ₁ ~SUS voltage below the discharge start voltage with respect to _n Vp
(V), the voltage Vr (V) exceeding the discharge starting voltage
A ramp voltage that gradually rises toward is applied. While the ramp voltage rises, in all the discharge cells 12, all the data electrodes D ₁ from all the scanning electrodes SCN ₁ ~SCN _n ~D _m and all the sustain electrodes SUS ₁ ~SUS _n
To occur weak setup discharges one time each, negative wall voltage is accumulated on the surface of the protective film 3 on the scanning electrodes SCN ₁ ~SCN _n, insulation on all the data electrodes D ₁ to D _m Surface of body layer 7 and all sustain electrodes SUS _{1 to} SUS _n
A positive wall voltage is accumulated on the surface of the upper protective film 3.

Furthermore, in the initialization operation of the second half of the initializing period, all the sustain electrodes SUS ₁ ~SUS _n positive voltage Vh
(V), and all the scan electrodes SCN _{1 to} SCN _n
For all of the sustain electrodes SUS _{1 to} SUS _n , the voltage Vq (V) which is lower than the discharge start voltage is set to 0 exceeding the discharge start voltage.
A ramp voltage gradually falling toward (V) is applied. While this ramp voltage is lowered, in all the discharge cells 12 again, it occurs all the scanning electrodes SCN ₁ ~SCN _n each second time weak setup discharges from all the sustain electrodes SUS ₁ ~SUS _n, all Scan electrodes SCN _{1 to} S
The negative wall voltage on the surface of the protective film 3 on CN _n and the positive wall voltage on the surface of the protective film 3 on all sustain electrodes SUS _{1 to} SUS _n are weakened. Also, between all the data electrodes D ₁ to D _m and all the scanning electrodes SCN ₁ ~SCN _n occurs weak discharge, all the data electrodes D ₁ to D _m on the surface of the insulator layer 7 The positive wall voltage is adjusted to a value suitable for a write operation.

Thus, the initialization operation in the initialization period is completed.

In the writing operation in the next writing period, all the scan electrodes SCN _{1 to} SCN _n are held at Vs (V), and the discharge electrodes 12 to be displayed on the first row among the data electrodes D _{1 to} D _m The corresponding predetermined data electrode D _j (j is 1
Ｍm), a positive write pulse voltage + Vw
(V), a scanning pulse voltage 0 (V) is applied to the scanning electrode SCN1 in the _first row. At this time, the voltage between the predetermined data electrode D _j and the scanning electrode SCN ₁ surface of the insulator layer 7 at the intersection between the scanning electrodes SCN ₁ on the protective film 3 on the surface, the write pulse voltage + Vw (V ), the positive wall voltage on the surface of the insulator layer 7 on the data electrodes D ₁ to D _m is what is added to, during in the intersection, the predetermined data electrode D _j and the scanning electrode SCN ₁ And sustain electrode SU
Write discharge occurs between S ₁ and scan electrode SCN ₁ ,
A positive voltage is accumulated on the surface of the protective film 3 on the scan electrode SCN _{1 at the} intersection, and a negative voltage is accumulated on the surface of the protective film 3 on the sustain electrode SUS _1.
A negative voltage is accumulated on the surface of the insulator layer 7 on _j .

[0010] Next, among the data electrodes D ₁ to D _m, a positive write pulse voltage to a predetermined data electrode D _j that corresponds to the discharge cell 12 to be displayed on the second line + Vw and (V), the second line applying the scanning electrode SCN ₂ in the scan pulse voltage 0 (V), respectively. At this time, the voltage between the predetermined data electrode D _j and the scanning electrode SCN ₂ surface of the insulator layer 7 at the intersection between the scanning electrode SCN ₂ on the protective film 3 on the surface, the write pulse voltage + Vw (V because) to be accumulated on the surface of the insulator layer 7 on the predetermined data electrode D _j the positive wall voltage is what is added, in the intersection, the predetermined data electrode D _j and the scanning electrode SCN ₂ And sustain electrode SUS
_A write discharge occurs between the scan electrode ₂ and the scan electrode SCN ₂ , a positive voltage is accumulated on the surface of the protective film 3 on the scan electrode SCN _{2 at the} intersection, and a negative voltage is accumulated on the surface of the protective film 3 on the sustain electrode SUS _2. Stored.

A similar operation is subsequently performed.
Among the data electrodes D ₁ to D _m, the predetermined data electrode D _j to the positive write pulse voltage corresponding to the discharge cells 12 to be displayed on the n th row + Vw and (V), n-th scanning electrode SCN _n
Is applied with a scanning pulse voltage of 0 (V). At this time, at the intersection of the predetermined data electrode D _j and the scanning electrode SCN _n, a write discharge between and between sustain electrode SUS _n and the scanning electrode SCN _n of the predetermined data electrode D _j and the scanning electrode SCN _n occurs, a positive wall voltage is accumulated on the protective film 3 surface on the scanning electrode SCN _n of the intersection, the sustain electrodes SU
S negative wall voltage on the protective film 3 surface on the _n is accumulated, negative wall voltage is accumulated on the surface of the insulator layer 7 on the data electrode D _j that write discharges have been induced.

Thus, the writing operation in the writing period is completed.

In the subsequent sustain period, first, all the scan electrodes SCN _{1 to} SCN _n and the sustain electrodes SUS _{1 to} SUS _n
Is once returned to 0 (V), and then all the scan electrodes SCN ₁ to
When applying a positive sustain pulse voltage + Vm (V) to SCN _n, a protective film 3 on the scanning in the discharge cell 12 having generated the address discharge electrode SCN _i (i is an integer of 1 to n)
Voltage between the surface and the sustain electrodes SUS ₁ ~SUS _n on the protective film 3 on the surface of, the sustain pulse voltage + Vm (V), the accumulated protective film 3 surface on the scanning electrode SCN _i at the write period Stored positive wall voltage and sustain electrode SUS
_The sum of the negative wall voltages accumulated on the surface of the protective film 3 on _i is higher than the discharge starting voltage. Therefore, in the discharge cell in which the write discharge has occurred, the scan electrode SCN
sustain discharge between the _i and the sustain electrode SUS _i occurs, negative wall voltage is accumulated on the protective film 3 surface on the scanning electrode SCN _i in a discharge cell having undergone the sustain discharge, sustain electrodes S
Positive wall voltage is accumulated in the protective film 3 surface on the US _i.
Thereafter, the sustain pulse voltage returns to 0 (V).

Subsequently, all the sustain electrodes SUS _{1 to} SUS _n
By applying positive sustain pulse voltage + Vm to (V), the voltage between the protective film 3 surface and the scanning electrode SCN _i on the protective film 3 surface on the sustain electrode SUS _i in a discharge cell having undergone the sustain discharge, the the sustain pulse voltage + Vm (V), the positive wall voltage at the negative wall voltage and the sustain electrode SUS _i on the protective film 3 surface of the protective film 3 surface on the scanning electrode SCN _i accumulated by the immediately preceding sustain discharge addition It was done. Therefore, in the discharge cell having undergone the sustain discharge, by the sustain discharge occurs between the sustain electrode SUS _i and the scanning electrode SCN _i, negatively protective film 3 surface on the sustain electrode SUS _i at the discharge cell The wall voltage is accumulated and the scan electrode SC
Positive wall voltage is accumulated in the protective film 3 surface on the N _i. Thereafter, the sustain pulse voltage returns to 0 (V).

Similarly, all the scan electrodes SCN _{1 to} SCN
By alternately applying a positive sustain pulse voltage + Vm (V) to CN _n and all sustain electrodes SUS _{1 to} SUS _n ,
Sustain discharge is continuously performed. In the last sustain period is applied to all the scanning electrodes SCN ₁ ~SCN _n a positive sustain pulse voltage + Vm (V), maintaining the protective film 3 surface on the scanning electrode SCN _i in a discharge cell having undergone the sustain discharge electrodes voltage between the protective film 3 surface on the SUS _i is the sustain pulse voltage + Vm (V), the protective film 3 surface on the stored scanning electrodes SCN _i to the sustain discharge just before the positive wall voltage and the sustain electrode The negative wall voltage on the surface of the protective film 3 on the SUS _i is added. Therefore, in the discharge cell having undergone the sustain discharge, the scan electrodes SCN _i and the sustain electrodes S
By a sustain discharge occurs between the US _i, negative wall voltage is accumulated in the protective film 3 surface on the scanning electrode SCN _i at the discharge cell, the sustain electrode SUS _i on the protective film 3 surface positive wall Voltage accumulates. Thereafter, the sustain pulse voltage returns to 0 (V). Thus, the maintenance operation of the maintenance period ends. Visible light emission from the phosphor 10 excited by ultraviolet rays generated by the sustain discharge is used for display.

In the subsequent erasing period, all the sustain electrodes S
US₁~ SUS_nFrom 0 (V) to + Ve (V)
When a gradually increasing lamp voltage is applied, sustain discharge
In the raised discharge cell, the scan electrode SCN_iProtection on
Membrane 3 surface and sustain electrode SUS_iBetween the upper protective film 3 surface
The voltage is the scan electrode SCN at the end of the sustain period.
_iNegative wall voltage on the surface of the protective film 3 and the sustain electrode SUS_i
The positive wall voltage on the surface of the upper protective film 3 is added to this lamp voltage
It was done. Therefore, a discharge that caused a sustain discharge
In the cell, the sustain electrode SUS_iAnd scanning electrode SCN_iWith
A weak erase discharge occurs between the scan electrodes SCN_iUpper guard
Negative wall voltage on the surface of protective film 3 and sustain electrode SUS_iUpper protective film
The positive wall voltage on the three surfaces is weakened, and the sustain discharge stops.

Thus, the erasing operation in the erasing period is completed.

However, in the above operation, with respect to the discharge cells in which no display is performed, an initialization discharge occurs during the initialization period, but no write discharge, sustain discharge and erase discharge are performed, and discharge cells in which no display is performed are performed. Scan electrode SCN _i
And sustain electrode SUS _i accumulated wall voltage on the surface of the protective film 3, and the data electrode D _j on the accumulated wall voltage on the surface of the insulator layer 7 is maintained while the state at the end of the initializing period It is.

With the above operations, one screen in the first subfield is displayed. Hereinafter, the same operation is performed from the second subfield to the eighth subfield. The luminance of the discharge cell displayed in these subfields is equal to the sustain pulse voltage + Vm
It is determined by the number of applications of (V). So, for example,
The number of application times of sustain pulse voltage in each subfield is set appropriately, the brightness due to the sustain discharge in one field period 2 ^0, 2 ^1, 2 ^2, be composed of eight subfields is ... 2 ⁷ Accordingly, gray scale display of 2 ⁸ = 256 gray scales becomes possible.

In the conventional driving method described above,
In a so-called black screen display where there are no discharge cells to be displayed on the panel, no write discharge in the write period, no sustain discharge in the sustain period and no erase discharge in the erase period occur,
Only the initializing discharge in the initializing period occurs, and the initializing discharge is weak, and the discharge light emission is also weak.
The feature is that the contrast of the panel is high. For example, in a 42-inch AC type plasma display panel having a matrix configuration of 480 rows and 852 × 3 columns, when one field period is composed of eight subfields and 256 gradations are displayed, the initial period of each subfield is set. The emission luminance due to the ^two setup discharges during the activation period was 0.15 cd / m ² . Therefore, the sum of the eight subfields is 0.15 × 8 = 1.2 cd / m ²
Since the maximum luminance is 420 cd / m ² , the contrast of this panel is 420 / 1.2: 1 = 350:
1, which is a very high contrast value.

[0021]

However, in the above-described conventional driving method, when a panel display is performed under normal illumination, a considerably high contrast is obtained.
Since the reset discharge always occurs twice for each subfield, when the panel is displayed in a dark place, the brightness is so high that even the light emission due to this weak reset discharge is conspicuous, and the panel is not so bright. There is a big problem that the visibility of black display when displaying is poor.

[0022]

Means for Solving the Problems In order to solve such problems, the present inventors have completed the present invention by examining the role of the initialization operation during the initialization period. .

Next, the reason why an initialization operation is required for each subfield in the conventional driving method will be described. Here, in the conventional driving waveform shown in FIG.
= 70V and Vm = 200V.

[0024] In the writing period, in order to cause a write discharge at a predetermined discharge cell, the discharge starting voltage (for example, about 250V) in the discharge space between the data electrodes D _j of the discharge cells with the scan electrodes SCN _i or voltage Must be applied. In the write operation, the write voltage of 70V is applied to the scanning electrode SCN _i is 0V data electrode D _j, to reliably perform the write operation, the data electrodes D
It is necessary to previously store a wall voltage of about 200 V on the insulator layer 7 on _j . The wall voltage required for this writing is defined as V _write (（200 V).

Further, although the wall voltage on the insulator layer 7 on the data electrode D _j by the sustain operation in the sustain period are accumulated, the value of the wall voltage at the sustain period ends, applied to the scan electrodes SCN _i considered to be a voltage value approximately intermediate between the voltage applied to the voltage between the sustain electrode SUS _i to be.
This wall voltage is set to V _sustain (（100 V).

[0026] Therefore, while moving from the end of the sustain operation in a certain subfield to the write operation of the next subfield, the wall voltage on the insulator layer 7 on the data electrode D _j from V _{sus tain} the V _write We need to change it. _{Compensating for} the difference V _write −V _sustain (（100 V) in the wall voltage is one of the main roles of the initialization operation, and the initialization operation is indispensable for driving the panel stably.

[0027] From the above consideration, the insulating layer 7 on the data electrode D _j at the sustain period ends at a certain sub-field
By performing the driving such that the upper wall voltage V _sustain is substantially the same as the wall voltage V _write required in the writing period in the next subfield, the initialization operation is simplified, and the unnecessary operation accompanying the initialization operation is unnecessary. It has been found that light emission can be eliminated. Based on this finding, it was possible to obtain a panel driving method capable of greatly improving the visibility of black and greatly increasing the contrast.

A method of driving an AC plasma display panel according to the present invention is a method of driving an AC plasma display panel which performs gradation display by forming one field period by a plurality of subfields having an initialization period, a writing period, and a sustain period. A driving method, wherein a sustaining operation of a sustaining period in at least one subfield of the plurality of subfields and an initializing operation of an initializing period of a subfield following the at least one subfield are simultaneously performed. It is.

According to this method, in the subfields subsequent to the second subfield, an initializing discharge occurs only in the discharge cells that have performed the display in the immediately preceding subfield, and an initializing discharge occurs in the discharge cells that do not perform the display. Can be eliminated.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An AC type plasma display panel (hereinafter referred to as a panel) used in the present invention is the same as the conventional example shown in FIG. The electrode arrangement of this panel is the same as that shown in FIG. Therefore, their description is omitted.

A panel driving method according to an embodiment of the present invention for driving the panel will be described.
FIG. 1 shows an operation driving timing chart of the driving method.

As shown in FIG. 1, one field period is
First having an initialization period, a write period, and a sustain period
Through the eighth subfield, thereby displaying 256 gradations. In the seven sub-fields of the eight sub-fields except the first sub-field, part of the initialization operation in the initialization period is performed simultaneously with the operation of maintaining the sustain period of the previous sub-field. I have to. In the first subfield, an initialization period, a writing period, and a sustaining period are provided independently, and no independent erasing period is provided. In the second subfield, a part of the initialization period overlaps with the sustain period of the first subfield, is provided with a write period and a sustain period, and is provided with an erase period. Absent. That is, at the same time as the sustaining operation in the sustaining period of the first subfield, the initialization operation in the initializing period of the second subfield is performed. Similarly, in the subsequent third to eighth subfields, an initialization period, a writing period, and a sustain period are provided. However, an erasing period is not provided, and the initialization operation in the initialization period of each subfield is performed. Some are performed simultaneously with the sustain operation in the sustain period of the immediately preceding subfield.

In FIG. 1, the operations in the initialization period and the writing period of the first subfield are the same as the operations described in the conventional example, so that the description thereof will be omitted. The fact that the operation in the sustain period of the first subfield and the operation in the initialization period of the second subfield are performed simultaneously is the main feature of the present invention, and will be described below with reference to FIGS. explain in detail.

As shown in FIG. 1, the sustain period of the first subfield overlaps with the period before the initialization period of the second subfield. In this overlap period, all the scan electrodes SCN ₁ are overlapped. ~ SCN _n and all sustain electrodes S
US ₁ to ~SUS _n, are applied so as to overlap the sustain pulse voltage Vm to DC voltage Vt (V) (V). That is, for low-level value of the scan pulse voltage applied to scan electrodes SCN ₁ ~SCN _n in the write period (0 (V)),
Low-level value of the sustain pulse voltage applied to the sustain electrodes SUS ₁ ~SUS _n and the scanning electrodes SCN ₁ ~SCN _n in the sustain period (Vt (V)) is at a high potential. Then, the pulse width of the last sustain pulse in the sustain period is made shorter than the pulse width of the other sustain pulses, and then the voltages of scan electrodes SCN _{1 to} SCN _n and sustain electrodes SUS _{1 to} SUS _n are changed to a fixed voltage Vu (V ).

[0035] Subsequently, in a period after following the previous period of the setup period of the second subfield, a positive voltage is applied Vh (V) to all the sustain electrodes SUS ₁ ~SUS _n, all the scanning electrodes SCN ₁ To SCN _n from voltage Vq ′ (V) to 0
A ramp voltage gradually falling toward (V) is applied. At this time, the voltage Vq '(V) does not need to be equal to the voltage Vq (V), and the voltage Vq' (V) is equal to the voltage Vq (V).
A lower voltage can be set.

In the above operation, the first subfield
Focusing on the operation during the sustain period of the scan electrodes, all the scan electrodes SC
N₁~ SCN_nAnd all sustain electrodes SUS₁~ SUS_nTo
Overlaps the DC voltage Vt (V) with the sustain pulse voltage Vm (V).
Tatami is applied. Therefore, all the scan electrodes SC
N₁~ SCN_nAnd all sustain electrodes SUS₁~ SUS_nBetween
Is related to the operation in the conventional driving method, that is,
All sustain electrodes SUS ₁~ SUS_nAnd all scan electrodes SC
N₁~ SCN_nAlternately with the positive sustain pulse voltage Vm (V)
Is equivalent to the case where For this reason,
In the same way as in the case above, it is maintained in the discharge cell
Discharge continues.

The pulse width of the last sustain pulse voltage applied during the sustain period is set to be shorter than 2 μs, which is the time when the discharge forms wall charges and stably ends. Subsequent scan electrode SCN ₁
To SCN _n and sustain electrodes SUS _{1 to} SUS _n are set to a constant voltage Vu (V). Thus, approximately equal to the wall voltage of the protective film 3 surface on the scanning electrode SCN ₁ ~SCN _n on the protective film 3 surface of the wall voltage and the sustain electrodes SUS ₁ ~SUS _n, so that the erasing operation is carried out . Also,
Such a sustain discharge does not occur in a discharge cell in which no write discharge has occurred.

Next, focusing on the initializing period of the second subfield, in the initializing operation before the initializing period, all the scan electrodes SCN _{1 to} SCN _n and all the data electrodes D _{1 to} D _m Is Vt (V) or Vt + V
m (V). In the discharge cells having generated the address discharge, the surface and the scanning electrode S of the insulator layer 7 on the data electrode D _j
The maximum voltage applied between the surfaces of the protective film 3 on CN _i is Vt
From + Vm (V) and the result of the addition of the positive wall voltage stored on the protective film 3 surface on the scanning electrode SCN _i, negative accumulated by the writing operation to the surface of the insulator layer 7 on the data electrode D _j (I.e., the sum of absolute values), and exceeds the discharge starting voltage. Therefore, the discharge from the scan electrodes SCN _i to the data electrode D _j occurs in the discharge cells having generated the address discharge. This is the initialization discharge for the data electrode D _j, and positive wall voltage is accumulated on the surface of the insulator layer 7 on the data electrode D _j. This setup discharge is generated every time a sustain pulse voltage is applied during a period before the setup period.

On the other hand, in the discharge cells in which writing is not carried out, the maximum voltage applied between the data electrodes D _j on the insulator layer 7 surface and the scanning electrode SCN _i on the protective film 3 surface is
A positive wall voltage stored on the protective film 3 surface of vt + Vm (V) and scanning electrode SCN _i from those obtained by adding, subtracting the positive wall voltage stored on the insulator layer 7 surface on data electrode D _j And does not exceed the discharge starting voltage. For this reason,
In the first subfield discharge cell write it was not, in the previous period of the setup period does not occur initializing discharge for the data electrode D _j.

Further, an initialization operation in a period after the initialization period
Then, all the sustain electrodes SUS₁~ SUS_nHas a positive voltage Vh
(V) is applied. In addition, all scan electrodes SCN₁~ S
CN _nHas all the sustain electrodes SUS₁~ SUS_nAgainst
From the voltage Vq ′ (V) that is lower than the discharge starting voltage,
The scanning pulse applied to the scanning electrode during the writing period exceeding the starting voltage
Towards 0 (V), which is equal to the low level value of the loose voltage
A ramp voltage that gradually decreases is applied. This run
During the period before the reset period, while the
In the discharge cell where the reset discharge has occurred, the sustain electrode SUS_iOr
Scan electrode SCN_iThe reset discharge occurs again. This first
Reset discharge is weak, and the scan electrode SCN_iUpper protective film 3
A positive wall voltage is applied to the surface of the_iNegative on the surface of
Each wall voltage accumulates slightly. Also, the data electrode
D_jAnd scanning electrode SCN_iAnd a weak discharge occurs between
Data electrode D_jThe positive charge accumulated on the surface of the upper insulator layer 7
The wall voltage is adjusted to a value suitable for a write operation. First time
For the discharge cells in which the initialization discharge did not occur,
Wall voltage already write operation in subfield
Is adjusted to a value suitable for
No chemical discharge occurs.

As is apparent from the above description, although the erasing period is not provided in the second to eighth subfields, the writing operation, the sustaining operation, the erasing operation, and the initializing operation of the next subfield are ensured. Done in Further, in each of the sub-fields after the second sub-field, the initializing discharge, the writing discharge, the sustaining discharge and the erasing discharge are not performed with respect to the discharge cells where no display is performed, and the scan electrode SCN ₁ corresponding to the discharge cell is not performed. ~ SCN _n
And the wall voltage of sustain electrodes SUS ₁ a wall voltage on the surface of the protective film 3 on ～SUS _n and data electrodes D ₁ to D _m on the surface of the insulator layer 7 is initialized in the immediately preceding subfield of each subfield It is kept at the end of the period.

As described above, in the embodiment of the present invention shown in FIG. 1, the weak initializing discharge in the initializing period in the first subfield is performed regardless of the presence or absence of display on the panel. On the other hand, in each of the subfields subsequent to the second subfield, the initializing discharge in the initializing period is performed only for the discharge cells for displaying the panel as the initializing operation for the next subfield. Also,
The brightness of the setup discharge is only added to the brightness of the sustain discharge, and such a setup discharge does not occur in a discharge cell that is not displayed.

For example, in a 42-inch AC type plasma display panel having a matrix configuration of 480 rows and 852.times.3 columns, when one field period is constituted by eight subfields and 256 gray scales are displayed, the maximum is obtained. The luminance was 420 cd / m ² , whereas the luminance due to ^two setup discharges in the setup period of the first subfield was 0.15 cd / m ² . Here, Vp = 1
90V, Vq = 190V, Vm = 200V, Vt = 10
0 V, Vu = 200 V, Vh = 300 V, Vq ′ = 10
0 V and Vs = 70 V. As a result, in the display of a so-called black screen where there are no discharge cells to be displayed on the panel, only the light emission of the initializing discharge in the first subfield is performed, so that the brightness of the black display is 0.15 cd / m ^2. When the panel is displayed in a dim place, the visibility of black display can be significantly improved as compared with the related art. Also, the contrast of the panel according to the present embodiment is 420 / 0.15: 1 = 2800: 1,
Very high contrast values were obtained.

Further, since a part of the initializing operation in the initializing period of the second to eighth subfields and the sustaining operation in the sustaining period of the immediately preceding subfield are simultaneously performed, the initialization is required. The time can be greatly reduced, and it is not necessary to provide an independent erasing period. Therefore, the driving time can be significantly reduced as compared with the conventional driving method. In the present embodiment, the initialization period in one field period is 1 ms, which can be significantly reduced as compared with the initialization period and the erasing period of 2.8 ms in the conventional driving method. Therefore, the driving method can be an effective driving method for a large panel or a high-definition panel whose driving time increases.

Next, FIG. 2 shows a drive waveform timing chart according to the second embodiment.

In the AC type plasma display panel, since the periphery of the discharge cell is surrounded by a dielectric and the drive waveform of each electrode is applied to the discharge cell in a capacitively coupled manner, each drive waveform is level-shifted in a DC manner. Also has the property that its operation does not change. Utilizing this property, the driving waveform as shown in FIG. 2, that is, the scanning electrode driving waveform and the sustain electrode driving waveform shown in FIG.
A drive waveform that is lowered only is applied. In this case, since the sustain pulse Vm can be created based on 0 V, the implementation is easy in circuit design.

In the above embodiment, the case where the last sustain pulse width in the sustain period is shortened and the erase operation for stopping the sustain discharge at the same time as the last sustain operation is performed has been described. An erasing operation may be performed.
Further, in the driving method of the AC type plasma display panel for performing the gray scale display by forming one field period by eight subfields having an initialization period, a writing period, and a sustaining period, of the eight subfields, With respect to the seven subfields, the driving method for simultaneously performing the sustaining operation in the sustaining period of a certain subfield and the initializing operation in the initializing period in the next subfield has been described, but the subfields constituting one field period are described. , The number of subfields without an erasing period, and the number of subfields for simultaneously performing the operation of maintaining the last part of the sustaining period and the operation of initializing the next subfield can be arbitrarily set. . Also, the driving waveform in the subfield is not limited. Further, the present invention can be applied to an AC plasma display panel having another configuration.

[0048]

As described above, according to the AC plasma display panel driving method of the present invention, the sustaining operation of the sustaining period in at least one of a plurality of subfields constituting one field. And the initialization operation of the initialization period in the subfield following the subfield at the same time,
Since the brightness in the so-called black screen display without display on the panel is extremely low, the visibility of black is greatly improved, and the contrast of the panel can be greatly increased.

Furthermore, the time required for initialization is greatly reduced, and the time required for erasure is not required, so that the driving time can be significantly reduced as compared with the conventional driving method. Therefore, the present invention is an effective driving method for a large-sized or high-definition panel.

[Brief description of the drawings]

FIG. 1 is an operation drive timing chart showing a method for driving an AC plasma display panel according to a first embodiment of the present invention;

FIG. 2 is an operation drive timing chart showing a method for driving an AC plasma display panel according to a second embodiment of the present invention;

FIG. 3 is a partial perspective view of a conventional AC plasma display panel.

FIG. 4 is an electrode arrangement diagram of a conventional AC plasma display panel.

FIG. 5 is an operation drive timing chart showing a method for driving a conventional AC plasma display panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 First glass substrate 2 Dielectric layer 3 Protective film 4 Scan electrode 5 Sustain electrode 6 Second glass substrate 7 Insulator layer 8 Data electrode 9 Partition wall 10 Phosphor 11 Discharge space 12 Discharge cell

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Kawachi 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 5C080 AA05 BB05 DD03 DD30 EE29 EE30 FF12 GG12 HH02 HH04 JJ04 JJ06

Claims (3)

[Claims] 1. A method of driving an AC-type plasma display panel for performing a gray scale display by forming one field period by a plurality of subfields having an initialization period, a writing period, and a sustain period, the method comprising: A method for driving an AC-type plasma display panel, wherein the sustaining operation of the sustaining period in at least one subfield and the initializing operation of the initializing period of the subfield subsequent to the at least one subfield are simultaneously performed. 2. A method of driving an AC plasma display panel in which a substrate on which a scan electrode and a sustain electrode are formed and another substrate on which a data electrode is formed are opposed to each other, wherein one field period is initialized. A plurality of sub-fields having a period, a writing period, and a sustain period. In the sustain period in at least one sub-field of the plurality of sub-fields,
The low-level value of the sustain pulse voltage applied to the scan electrode and the sustain electrode is set higher than the low-level value of the scan pulse voltage applied to the scan electrode in the writing period. A method for driving an AC plasma display panel, wherein a sustaining operation of a sustaining period in one subfield and an initializing operation of an initializing period of a subfield subsequent to the at least one subfield are simultaneously performed. 3. The method according to claim 1, wherein a last sustain pulse width applied to the scan electrode or the sustain electrode in the sustain period of the at least one subfield is set shorter than other sustain pulse widths. 3. The method of driving an AC-type plasma display panel according to claim 2, wherein an erasing operation for stopping the sustaining discharge is performed simultaneously with the sustaining operation.