JP2004013168A - Method for driving ac type plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the serious problem of a plasma display panel that visibility of black display is poor in the case of panel display in a place which is not sufficiently bright. <P>SOLUTION: In an initialization period of at least one of a plurality of sub-fields, a voltage dropping from a voltage equal to or lower than a discharge start voltage for a maintaining electrode toward a voltage higher than the discharge start voltage is applied to a scanning electrode after voltage rising from a voltage equal to or lower than a discharge start voltage for the maintaining electrode toward a voltage higher than the discharge start voltage is applied to the scanning electrode. In the remaining initialization periods of the other sub-fields, voltage slowly changing from a voltage equal to or lower than a discharge start voltage for the maintaining electrode toward a voltage higher than the discharge start voltage is applied to the scanning electrode in a period after the end of the sub-field maintaining period to the write period. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a method for driving an AC-type plasma display panel used for image display of a television receiver, a computer terminal, and the like.

FIG. 2 is a partial perspective view of a conventional AC plasma display panel (hereinafter, referred to as a panel). As shown in FIG. 2, 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 a dielectric layer 7 are provided on the second glass substrate 6, and a partition 9 is provided on the dielectric layer 7 between each of the data electrodes 8 in parallel with the data electrodes 8. Is provided. Phosphors 10 are formed on the surface of the dielectric layer 7 and on both sides of the partition wall 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 sustain electrodes 5 are orthogonal to the data electrodes 8. The discharge space 11 is filled with at least one rare gas of helium, neon, argon, and xenon as a discharge gas. Discharge cells 12 are formed in the discharge spaces at the intersections of the scan electrodes 4 and the sustain electrodes 5 which are sandwiched between two adjacent partitions 9 and face the data electrodes 8.

Next, FIG. 3 shows an electrode arrangement diagram of this panel. As shown in FIG. 3, the electrode array of this panel has an M × N matrix configuration, M columns of data electrodes D _{1 to} D _M are arranged in the column direction, and N rows of scans are arranged in the row direction. electrodes SCN ₁ ~SCN _N and sustain electrodes SUS ₁ ~SUS _N are arranged. Further, the discharge cells 12 shown in FIG. 2 are provided in a region as shown in FIG.

FIG. 4 shows an operation drive timing chart of a conventional drive method for driving this panel. This driving method is for displaying 256 gradations, and one field period is composed of eight subfields. Hereinafter, a conventional panel driving method will be described with reference to FIGS.

(4) As shown in FIG. 4, the first to eighth sub-fields each include an initialization period, a writing period, a sustain period, and an erasing period. First, the operation in the first subfield will be described.

As shown in FIG. 4, in the initializing operation in the first half of the initializing period, all the data electrodes D _{1 to} D _M and all the sustain electrodes SUS _{1 to} SUS _N are held at 0 (V), and all the scanning electrodes are held. the SCN ₁ ~SCN _N, all the sustain electrodes SUS ₁ ~SUS _N respect to the discharge starting voltage following voltage Vp (V), gradually rises toward the voltage Vr (V) exceeding the discharge start voltage Apply lamp voltage. While the ramp voltage rises, in all the discharge cells 12, all the scanning electrodes SCN ₁ from ～SCN _N all the data electrodes D ₁ to D _M and all the sustain electrodes SUS ₁ ~SUS _N at a time of each occur weak setup discharges, along with the negative wall voltage on the surface of the protective film 3 on all the scanning electrodes SCN ₁ ~SCN _N is accumulated, the dielectric layer on all the data electrodes D ₁ to D _M 7 And the surface of the protective film 3 on all the sustain electrodes SUS _{1 to} SUS _N accumulates a positive wall voltage.

Further, in the initialization operation of the second half of the setup period, keeping all the sustain electrodes SUS ₁ ~SUS _N to a positive voltage Vh (V), to all the scanning electrodes SCN ₁ ~SCN _N, all the sustain electrodes SUS ₁ applying a ramp voltage that gently decreases from ～SUS _N to the discharge starting voltage following voltage Vq (V) to 0 (V) exceeding the discharge start voltage. While this ramp voltage is lowered, in all the discharge cells 12 again, 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 negative wall voltage and all the sustain electrodes SUS ₁ ~SUS _N positive wall voltage stored on the protective film 3 surface on which is accumulated in the protective film 3 surface on the scanning electrode SCN ₁ ~SCN _N of weakened. On the other hand, the positive wall voltage accumulated on the surface of the dielectric layer 7 on all the data electrodes D _{1 to} D _M is kept as it is.

The initialization operation in the initialization period is completed as described above.

In the writing operation of the next write period, holds all the scanning electrodes SCN ₁ ~SCN _N to Vs (V), among the data electrodes D ₁ to D _M, predetermined corresponding to the discharge cells 12 to be displayed on the first line , A positive write pulse voltage + V _W (V) is applied to the data electrode D _j (j represents an integer of 1 to M), and a scan pulse voltage 0 (V) is applied to the scan electrode SCN1 in the _first row. At this time, the voltage between the predetermined data electrode D _j and the scanning electrode SCN ₁ dielectric layer 7 surface at the intersection between the scanning electrodes SCN ₁ on the protective film 3 on the surface, the write pulse voltage + V _W ( since the positive wall voltage stored on the surface of the dielectric layer 7 on the data electrodes D ₁ to D _M in V) is that obtained by adding, in the cross section, the scanning electrodes SCN and the predetermined data electrode D _{j 1} and between the sustain electrode SUS ₁ and the scan electrode SCN ₁ , a write discharge occurs, and a positive wall voltage is accumulated on the surface of the protective film 3 on the scan electrode SCN _{1 at the} intersection, and the sustain electrode SUS ₁ negative wall voltage is accumulated in the protective film 3 surface of the upper, negative wall voltage on the surface of the dielectric layer 7 on the data electrode D _j is accumulated.

Next, among the data electrodes D ₁ to D _M, the predetermined data electrode D _j to the positive write pulse voltage + V _W corresponding to a discharge cell 12 to be displayed on the second line (V), the second line scan scan pulse voltage to the electrode SCN ₂ 0 (V) is applied respectively. At this time, the voltage between the predetermined data electrode D _j and the scanning electrode SCN ₂ dielectric layer 7 surface at the intersection between the scanning electrode SCN ₂ on the protective film 3 on the surface, the write pulse voltage + V _W ( since the positive wall voltage stored on the surface of the dielectric layer 7 on the predetermined data electrode D _j to V) is that obtained by adding, in the cross section, scanning the predetermined data electrode D _j electrode SCN ₂ And between the sustain electrode SUS ₂ and the scan electrode SCN ₂ , a write discharge occurs, and a positive wall voltage is accumulated on the surface of the protective film 3 on the scan electrode SCN _{2 at the} intersection, and the write discharge occurs on the sustain electrode SUS ₂ . , A negative wall voltage is accumulated on the surface of the protective film 3.

It performed subsequent similar operation, and finally, 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 + V _W ( the V), respectively applied scan pulse voltage 0 (V) to the N-th scanning electrode SCN _N. At this time, at the intersection of the predetermined data electrode D _j and the scanning electrode SCN _N, a write discharge occurs between the predetermined data electrode D _j and between sustain electrode SUS _N and scan electrodes SCN _N and the scanning electrode SCN _N occurs, the protective film 3 surface on the scanning electrode SCN _N at the intersection positive wall voltage accumulates negative wall voltage is accumulated in the protective film 3 surface on the sustain electrodes SUS _N, the predetermined data electrode D _A negative wall voltage is accumulated on the surface of the dielectric layer 7 on _j .

書 き 込 み The writing operation in the writing period is completed as described above.

In subsequent sustain period, first, after returning once to all the scanning electrodes SCN ₁ ~SCN _N and sustain electrodes SUS ₁ ~SUS _N to 0 (V), all the scanning electrodes SCN ₁ ~SCN _N a positive sustain pulse voltage + is applied Vm to (V), scanning electrode SCN _i in a discharge cell 12 having generated the address discharge (i is an integer of 1 to N) on the protective film on the third surface and the sustain electrodes SUS _i a protective film 3 of the voltage between the surface, sustain pulse voltage + Vm (V), the protective film on the wall voltages accumulated in the accumulated protective film 3 surface on the scanning electrode SCN _i positive and sustain electrode SUS _i at the write period The negative wall voltage accumulated on the three surfaces is the sum of the negative wall voltages, and exceeds the discharge starting voltage. Therefore, in the discharge cells having generated the address discharge, a sustain discharge occurs between sustain electrode SUS _i and the scanning electrode SCN _i, the negative wall voltage on the protective film 3 surface on the scanning electrode SCN _i at the discharge cells There are accumulated, the protective film 3 surface on the sustain electrode SUS _i and a positive wall voltage is accumulated. Thereafter, the sustain pulse voltage returns to 0 (V).

Then, applying all sustain electrodes SUS ₁ ~SUS _N a positive sustain pulse voltage + Vm (V), the surface and the scanning electrodes of the protective film 3 on the sustain electrode SUS _i in a discharge cell having undergone an address discharge SCN _i voltage between the protective film 3 on the surface of the above, the sustain pulse voltage + Vm (V), negative wall voltage of the protective film 3 surface on the scanning electrode SCN _i accumulated by the immediately preceding sustain discharge and the sustain electrodes SUS The positive wall voltage on the surface of the protective film 3 on _i is added. Therefore, in the discharge cells having generated the address discharge, by the sustain discharge occurs between the sustain electrode SUS _i and the scanning electrode SCN _i, the negative wall protective film 3 surface on the sustain electrode SUS _i at the discharge cell voltage is accumulated, and positive wall voltage is accumulated on the protective film 3 surface on the scanning electrode SCN _i. Thereafter, the sustain pulse voltage returns to 0 (V).

Hereinafter, similarly, by applying all the scanning electrodes SCN ₁ ~SCN _N and all the sustain electrodes SUS ₁ ~SUS _N and the positive sustain pulse voltage + Vm (V) is alternately 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), and the protective film 3 on the surface on the scanning electrode SCN _i in the discharge cells having generated the address discharge voltage between the protective film 3 on the surface of the sustain electrode SUS _i is the sustain pulse voltage + Vm (V), the accumulated scan electrode SCN _i on the protective film 3 surface by the immediately preceding sustain discharge positive wall voltage negative wall voltage of the protective film 3 surface on the sustain electrode SUS _i is what is added to. Therefore, in the discharge cells having generated the address discharge, by the sustain discharge occurs between the sustain electrode SUS _i and the scanning electrode SCN _i, the negative wall protective film 3 surface on the scanning electrode SCN _i at the discharge cell voltage is accumulated, and positive wall voltage is accumulated on the protective film 3 surface on the sustain electrode SUS _i. 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.

In the subsequent erasing period, when a ramp voltage that gradually increases from 0 (V) to + Ve (V) is applied to all sustain electrodes SUS _{1 to} SUS _N , scan electrodes SCN are generated in discharge cells 12 that have undergone a sustain discharge. voltage between the protective film 3 on the surface of the _i and sustain electrode SUS _i on the protective film 3 on the surface is the sustain period at the last point, the scanning electrodes on the SCN _i protective film 3 surface negative accumulated in becomes the positive wall voltage stored on the protective film 3 surface on the wall voltage and the sustain electrode SUS _i is added to the lamp voltage. Therefore, in the discharge cells having undergone the sustain discharge, sustain a weak erase discharge between the electrode SUS _i and the scanning electrode SCN _i occurs, negative wall voltage stored in the protective film 3 surface on the scanning electrode SCN _i a sustain discharge sustain electrodes SUS _i on the protective film 3 accumulated positive wall voltage is weakened on the surface is stopped.

(4) The erasing operation in the erasing period is completed as described above.

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 the write discharge, the sustain discharge and the erase discharge are not performed, and the scan electrodes of the discharge cells in which no display is performed are performed. SCN _i and the sustain electrode SUS _i accumulated wall voltage on the surface of the protective film 3, and the wall voltage accumulated on the surface of the dielectric layer 7 on the data electrode D _j is at the end of the state of the initialization period Will be kept as it is.

One screen in the first subfield is displayed by all the above operations. 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 the sustain pulse voltage + Vm (V) is applied. Thus, for example, by setting the number of application times of sustain pulse voltage in each subfield appropriate, 1 ⁰ luminance by the sustain discharge in the field period 2, 2 ^1, 2 ^2, eight subfields are ... 2 ⁷ , Gray scale display of 2 ⁸ = 256 gray scales becomes possible.

In the conventional driving method described above, there is no discharge cell to be displayed on the panel, that is, in the display of a so-called black screen, the write discharge in the write period, the sustain discharge in the sustain period, and the erase discharge in the erase period do not occur, and the Only the initializing discharge during the reset period occurs, the initializing discharge is weak, and the discharge light emission is also weak, so that there is a feature 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 gradation display is performed, 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 and the maximum luminance is 420 cd / m ² , so that the contrast of this panel is 420 / 1.2: 1 = 350. : 1 and a considerably high contrast is obtained.

However, in the above-described conventional driving method, when a panel display is performed under normal illumination, a considerably high contrast is obtained. However, since the initialization discharge always occurs twice for each subfield, the surrounding discharge is generated. However, when a panel is displayed in a dark place, there is a big problem that the luminance is so high that even the light emission due to the weak initializing discharge is conspicuous, and the visibility of black display is poor when the panel is displayed in a place that is not very bright. Was.

In order to solve such a problem, a driving method of an AC plasma display panel according to the present invention performs gradation display by forming one field period by a plurality of subfields having an initialization period, a writing period, and a sustaining period. A method of driving an AC type plasma display panel, wherein during an initialization period of at least one of a plurality of subfields, a discharge start voltage is applied to the scan electrode from a voltage lower than or equal to a discharge start voltage with respect to a sustain electrode. After applying a voltage that increases toward a voltage that exceeds the voltage, a voltage that decreases from a voltage that is equal to or less than the discharge start voltage to a voltage that exceeds the discharge start voltage is applied to the scan electrode, and the remaining subfields During the initialization period, the scan electrodes are maintained during the writing period after the end of the sustain period of the previous subfield. And applying a voltage gradually changes toward a voltage exceeding the discharge start voltage from the voltage to be discharge start voltage or less with respect to the pole.

According to the driving method of the AC plasma display panel of the present invention, the last sustaining operation of the sustaining period in at least one of the plurality of subfields constituting one field, and the subfield following the subfield Is performed simultaneously with the initialization operation of the initialization period, so that the brightness in the so-called black screen display without display on the panel becomes extremely low, so that the visibility of black is greatly improved and the contrast of the panel is greatly enhanced. be able to.

(2) The 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 description will be given of a panel driving method according to an embodiment of the present invention for driving the panel. FIG. 1 shows an operation driving timing chart of the driving method.

As shown in FIG. 1, one field period is composed of first to eighth subfields having an initialization period, a writing period, a sustaining period, and an erasing period, thereby displaying 256 gradations. It is. In the seven subfields excluding the first subfield out of these eight subfields, the initialization operation of the initialization period is performed simultaneously with the last maintenance operation of the sustain period of the previous subfield. I have. That is, in the first subfield, the initialization period is provided independently, and the write period and the sustain period are provided, but the erase period is not provided. In addition, at the same time as the sustain operation by applying the last sustain pulse voltage in the sustain period, the initialization operation in the initialization period of the second subfield is performed. Similarly, in the subsequent third to seventh subfields, an initialization period, a writing period, and a sustain period are provided, but an erasing period is not provided, and the initialization operation in the initialization period is performed in the previous subfield. It is performed simultaneously with the last maintenance operation of the field maintenance period. In the eighth sub-field, a sustain period is provided independently, and an erase period is provided after the sustain period. Further, the initializing operation in the initializing period of the eighth subfield is performed simultaneously with the final maintaining operation of the sustaining period of the seventh subfield.

In FIG. 1, operations up to the end of the initializing period, the writing period, and the sustaining period of the first subfield are the same as the operations described in the conventional example, and a description thereof will be omitted. The fact that the operation of the last part of the sustain period and the operation of the initialization period of the second subfield are performed at the same time is the focus of the present invention, and will be described in detail below with reference to FIGS. .

As shown in FIG. 1, the last part of the sustain period of the first subfield overlaps with the first half of the initialization period of the second subfield. In this overlap period, all the scan electrodes SCN ₁ to SCN ₁ to are overlapped. positive pulse voltage Vr (V) is applied to SCN _N, it is applied to all the sustain electrodes SUS ₁ ~SUS _N a positive pulse voltage of (Vr-Vm) (V). Subsequently, in the second half of the initializing period of the second subfield, a positive voltage Vh to all the sustain electrodes SUS ₁ ~SUS _N (V) is applied to all the scanning electrodes SCN ₁ ~SCN _N, voltage Vq ( A ramp voltage that gradually decreases from V) to 0 (V) is applied.

In the above operation, paying attention to the operation of the last sheet of the sustain period of the first subfield, the voltage between all the scanning electrodes SCN ₁ ~SCN _N and all the sustain electrodes SUS ₁ ~SUS _N is, Vr- (Vr-Vm) = Vm ( V) , and the relationship between all the scanning electrodes SCN ₁ ~SCN _N and all the sustain electrodes SUS ₁ ~SUS _N is similar to the operation before the last part of the sustain period to all the sustain electrodes SUS ₁ ~SUS _N and 0 (V), it happens when the equivalent is being applied positive sustain pulse voltage Vm (V) is in all the scanning electrodes SCN ₁ ~SCN _N. Therefore, as explained in the conventional example, protecting the scanning electrodes SCN i in a discharge cell 12 having generated the address discharge _(i is an integer that the 1 to N) on the protective film 3 on the surface and the sustain electrode SUS _i voltage between the surface of the film 3, the sustain pulse voltage Vm (V), its on scan electrode SCN _i in discharge cell 12 protective film 3 is accumulated on the surface the positive wall voltage on sustain electrode SUS _i The sum of the negative wall voltages accumulated on the surface of the protective film 3 is higher than the discharge starting voltage. Therefore, in the discharge cells 12 having generated the address discharge, a sustain discharge occurs between sustain electrode SUS _i and the scanning electrode SCN _i, the negative wall protective film 3 surface on the scanning electrode SCN _i at the discharge cell 12 voltage is accumulated, and positive wall voltage is accumulated on the protective film 3 surface on the sustain electrode SUS _i. Therefore, the final maintenance operation is performed in the same manner as described in the conventional example. Such a sustain discharge does not occur in a discharge cell in which no writing is performed.

Then, during the focusing on initializing period of the second subfield, the initializing operation in the first half of the initializing period, all the scanning electrodes SCN ₁ ~SCN _N and all the data electrodes D ₁ to D _M the voltage Vr (V) and the voltage between all the scanning electrodes SCN ₁ ~SCN _N and all the sustain electrodes SUS ₁ ~SUS _N becomes Vm (V). In the discharge cells having generated the address discharge, the voltage of the surface of the protective film 3 on the surface and the scanning electrode SCN _i of the dielectric layer 7 on the data electrode D _j is, Vr (V) and a protective film on the scanning electrode SCN _i the accumulated positive wall voltage from those added to the third surface, minus the negative wall voltage stored at the surface of the dielectric layer 7 on the data electrode D _j during the write operation, that is, the absolute value The sum is the sum, and exceeds the discharge starting voltage. Therefore, in the discharge cells having generated the address discharge, a discharge occurs from the scanning electrode SCN _i to the data electrode D _j, to all the sustain electrodes SUS ₁ ~SUS _N from the scanning electrodes SCN ₁ ~SCN _N is dragged into the discharge discharge occurs, which becomes a first-time setup discharges, negative wall voltage is accumulated on the surface of the protective film 3 on the scanning electrode SCN _i, surface and sustain electrodes SUS _i a dielectric layer 7 on the data electrode D _j A positive wall voltage is accumulated on the surface of the upper protective film 3.

However, the first initializing discharge is not weak, but rather a strong discharge.

On the other hand, in the discharge cells in which writing has not been performed, the voltage of the surface of the protective film 3 on the data electrode D _j on the dielectric layer 7 surface and the scanning electrode SCN _i of, Vr (V) and the scanning electrode SCN _i and from the result of the addition of the wall voltage of the accumulated positive on the surface of the protective film 3 becomes a minus a positive wall voltage is accumulated on the surface of the dielectric layer 7 on the data electrode D _j, discharge starting voltage Does not exceed. Therefore, the first setup discharge does not occur in the discharge cells in which no writing has been performed in the first subfield.

Further, the initialization operation in the second half of the initializing period is the same as the second half of the operation of the initializing period in the first subfield, a positive voltage Vh to all the sustain electrodes SUS ₁ ~SUS _N (V) is applied , to all the scanning electrodes SCN ₁ ~SCN _N, gently toward 0 (V) exceeding the discharge start voltage from the voltage becomes the discharge start voltage or less with respect to all the sustain electrodes SUS ₁ ~SUS _N Vq (V) A falling ramp voltage is applied. While this ramp voltage is lowered, the first time the discharge cells 12 that initializing discharge occurs, and occurs weak setup discharges a second time to scan electrode SCN _i from the sustain electrode SUS _i, on the scanning electrode SCN _i positive wall voltage stored on the surface of the negative wall voltage stored on the surface of the protective film 3 and the sustain electrode SUS _i are weakened. On the other hand, positive wall voltage on the surface of the dielectric layer 7 on the data electrode D _j is maintained as it is. For first time discharge cell initializing discharge did not occur in the by the operation of the second half of the initializing period in the first subfield, the wall voltage on the surface of the protective film 3 on the sustain electrode SUS _i and the scanning electrode SCN _i is The second initializing discharge described above does not occur because it has already been weakened.

As can be understood from the above description, the initializing operation in the second half of the initializing period in the second sub-field is performed immediately after the end of the last sustain discharge in the first sub-field, and the discharge cell performing the display is displayed. in 12, maintained by the weak setup discharges are induced in the electrodes SUS ₁ ~SUS _N from the scanning electrodes SCN ₁ ~SCN _N, accumulated negative wall surface of the protective film 3 on the scanning electrodes SCN ₁ ~SCN _N since the voltage and the sustain electrodes SUS ₁ ~SUS _N positive wall voltage stored on the surface of the protective film 3 on the weakened, results in the erase operation of the sustain discharge has been performed, dare it is not necessary to provide a blanking period .

At this time, in the discharge cells displayed in the first subfield, the first initializing discharge by the initializing operation in the first half of the initializing period in the second subfield is not weak, but is caused by this initializing discharge. The luminance is considerably higher than the luminance of the second weak initializing discharge due to the initializing operation in the latter half of the initializing period. However, since these two setup discharges are performed only in the discharge cells 12 to be displayed, the brightness of the setup discharge in the second subfield is only added to the brightness of the sustain discharge.

For a discharge cell in which no display is performed, an initialization discharge occurs during the initialization period of the first subfield, but a write discharge, a sustain discharge, and an erase discharge are not performed, and the scan electrode SCN corresponding to the discharge cell is not performed. ₁ ～SCN _N and sustain electrodes SUS ₁ to S the wall voltage on the surface of the protective film 3 on the _N and the data electrodes D ₁ to D wall voltage on the surface of the dielectric layer 7 on _M, the initial of the first subfield At the end of the activation period.

As is clear from the above description, no erase period is provided in the second to seventh subfields, but the write operation, the sustain operation, the erase operation, and the initialization operation of the next subfield are reliably performed. . Further, in each of the sub-fields after the second sub-field, the initialization discharge, the write discharge, the sustain discharge, and the erase discharge are not performed for the discharge cell in which no display is performed, and the scan electrode SCN ₁ corresponding to the discharge cell is not performed. ～SCN _N and the wall voltage on the surface of the dielectric layer 7 on the wall voltages and the data electrodes D ₁ to D _M of the sustain electrode group SUS ₁ ~SUS _N on the protective film 3 on the surface of the previous sub of each subfield Retained at the end of the field initialization period.

{Circle around (8)} In the eighth sub-field, a single sustain period and an erase period are provided, and the erase operation is performed continuously from the normal sustain operation, as in the conventional example. That is, the operation from the sustain period and the erasing period of the eighth subfield shown in FIG. 1 to the initializing period of the next first subfield is the same as the operation shown in the conventional example.

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. In the subfields after the second subfield, the initializing discharge in the initializing period is performed as an initializing operation for the next subfield only for the discharge cells for displaying the panel, and the luminance of this discharge is This is only added to the luminance of the sustain discharge, and such an initializing discharge does not occur in a discharge cell that does not display.

For example, in a 42-inch AC plasma display panel having a matrix configuration of 480 rows and 852 × 3 columns, when one field period is formed of eight subfields and a 256-gradation display is performed, the maximum luminance is 420 cd. / m ² that whereas now, the luminance by two times of the initialization discharge in the initialization period in the first subfield was 0.15 cd / m ^2. Here, Vp = Vq = Vm = 190 V, Vr = 370 V, Vs = 70 V, and Vh = 210 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 dimly lit place, the visibility of black display is significantly improved as compared with the conventional case. Further, the contrast of the panel according to the present embodiment was 420 / 0.15: 1 = 2800: 1, and an extremely high value of contrast was obtained.

In the above embodiment, the voltage Vr (V) applied during the initializing period of the first subfield and the voltage Vr (V) applied during the initializing period of the second to eighth subfields Although the case where the same value is used has been described, a different value may be used.

Further, in the above-described embodiment, in the driving method of the AC type plasma display panel for performing gradation display by forming one field period by eight subfields having an initialization period, a writing period, and a sustain period, The driving method for simultaneously performing the sustaining operation of the last part of the sustaining period and the initializing operation of the initializing period of the next subfield for seven subfields among the seven subfields has been described. Limit the number of constituent subfields, the number of subfields without an erasing period, and the number of subfields that simultaneously perform the sustaining operation of the last part of the sustaining period and the initializing period of the next subfield It does not do. Further, 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.

As described above, according to the present invention, the brightness in the so-called black screen display is extremely low, so that the visibility of black is greatly improved and the contrast of the panel can be greatly increased.

Operation driving timing chart showing a driving method of an AC type plasma display panel according to one embodiment of the present invention Partial cutaway perspective view of a conventional AC type plasma display panel. Electrode arrangement diagram of conventional AC type plasma display panel Operation drive timing diagram showing a conventional AC plasma display panel driving method

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 First glass substrate 2 Dielectric layer 3 Protective film 4 Scan electrode 5 Sustain electrode 6 Second glass substrate 7 Dielectric layer 8 Data electrode

Claims (1)

A substrate on which scan electrodes and sustain electrodes are formed and another substrate on which data electrodes are formed are opposed to each other to form an AC plasma display panel having a plurality of discharge cells, and one subfield constitutes one field period. In the driving method for performing gradation display by performing a gradation display, a plurality of sub-fields include an initializing period in which an initializing discharge is generated by applying a voltage to at least a scan electrode and a sustain electrode, and a write discharge in a discharge cell after the initializing period. And a sustain period in which a sustain pulse voltage is applied to the scan electrode and the sustain electrode to cause a sustain discharge after the write period, and an initialization period of at least one subfield of the plurality of subfields is A voltage exceeding the discharge starting voltage from a voltage lower than the discharge starting voltage with respect to the sustain After applying a voltage that increases toward the scan electrode, a voltage that decreases from the voltage below the discharge start voltage to the voltage above the discharge start voltage is applied to the scan electrode to the sustain electrode, and the remaining subfields are initialized. The period is a voltage that gradually changes from a voltage lower than the discharge start voltage to a voltage higher than the discharge start voltage with respect to the sustain electrode in the scan electrode during a period from the end of the sustain period of the previous subfield to the write period. A method for driving an AC-type plasma display panel, characterized in that:

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