JP2007078946A - Driving method for plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display an image hardly causing pseude contour while shortening a write period without degrading an image display quality. <P>SOLUTION: In the driving method for a plasma display panel, a one-field period comprises a plurality of sub-fields each having a write period and a sustain period, and includes a sub-field group comprising two or more successive sub-fields, and discharge cells which do not have write discharge in a write period of one of sub-fields belonging to the sub-field period has no write discharge even in the write period from the sub-field to the final sub-field belonging to the sub-field group so that scanning pulses temporally overlap with none of other scanning pulse in a write period of a sub-field which do not belong to the sub-field group and portions of scanning pulses temporally overlap with portions of other scanning pulses in a write period of a sub-field belonging to the sub-field group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for driving a plasma display panel.

  A typical AC surface discharge type panel as a plasma display panel (hereinafter abbreviated as “panel”) has a large number of discharge cells formed between a front plate and a back plate arranged to face each other. In the front plate, a plurality of pairs of display electrodes made up of a pair of scan electrodes and sustain electrodes are formed on the front glass substrate in parallel with each other, and a dielectric layer and a protective layer are formed so as to cover the display electrodes. The back plate has a plurality of parallel data electrodes on the back glass substrate, a dielectric layer so as to cover them, and a plurality of barrier ribs in parallel with the data electrodes formed on the back glass substrate. A phosphor layer is formed on the side walls of the barrier ribs. Then, the front plate and the back plate are arranged opposite to each other so that the display electrode and the data electrode are three-dimensionally crossed and sealed, and a discharge gas is sealed in the internal discharge space. Here, a discharge cell is formed at a portion where the display electrode and the data electrode face each other. In the panel having such a configuration, ultraviolet light is generated by gas discharge in each discharge cell, and phosphors of red, green, and blue colors are excited and emitted by the ultraviolet light to perform color display.

  The subfield method is used as a method for driving the panel. This is a method of performing gradation display by dividing one field period into a plurality of subfields and controlling each discharge cell to emit or not emit light in each subfield. Each of the subfields has an address period and a sustain period, and an initialization period as necessary. In the initializing period, initializing discharge is performed in the discharge cells, and wall charges necessary for the subsequent address operation are formed. In the address period, a scan pulse is sequentially applied to the scan electrode and an address pulse corresponding to the input image signal is applied to the data electrode, and the scan electrode is selectively between the scan electrode and the data electrode and between the scan electrode and the sustain electrode. An address discharge is generated to form wall charges. In the subsequent sustain period, sustain pulses of the number of times corresponding to the luminance to be displayed are applied between the scan electrodes and the sustain electrodes, and the discharge cells in which the wall charges are formed by the address discharge are selectively discharged to emit light. The ratio of the luminance to be displayed for each subfield is hereinafter referred to as “luminance weight”.

  Among the subfield methods, Patent Document 1 discloses a novel driving method in which the contrast ratio is improved by reducing light emission in an initialization period not related to gradation expression. Specifically, for example, among all the subfields, an all-cell initializing operation is performed in which all discharge cells are discharged in the initializing period of one subfield, and a sustain discharge is performed in the initializing period of the other subfield. A selective initialization operation for initializing only the performed discharge cells is performed. As a result, the light emission not related to the display is only the light emission associated with the discharge in the all-cell initializing operation, and an image display with a high contrast is possible.

In the subfield method, consecutive M (2 ≦ M ≦ N) subfields in N subfields constituting one field are defined as subfield groups, and each subfield group includes For example, Patent Document 2 discloses a novel panel driving method for controlling the discharge cells so that subfields that should emit light are continuous. According to this driving method, there is an advantage that the pseudo contour can be suppressed because the change in the light emission pattern accompanying the change in the gradation of the display image can be relatively small.
JP 2000-242224 A JP 2003-76322 A

  However, the number of gradations that can be displayed is reduced by controlling the subfields that should emit light to each discharge cell to be continuous. Therefore, in practice, the number of gradations that can be displayed is increased by increasing the number of subfields. In order to sufficiently increase the number of subfields, it is necessary to shorten the writing time in order to secure the time required for driving.

  The present invention has been made in view of these problems, and it is an object of the present invention to provide a panel driving method capable of shortening the writing time without deteriorating the image display quality and enabling image display in which pseudo contours are not easily generated. And

  The present invention relates to a panel driving method in which discharge cells are formed at intersections of scan electrodes, sustain electrodes, and data electrodes, and sequentially applies scan pulses to the scan electrodes and selectively applies write pulses to the data electrodes. A plurality of sub periods each having an address period for selectively generating an address discharge in the discharge cells and a sustain period for generating a sustain discharge for causing the discharge cells that selectively generate the address discharge in the address period to emit light One field period is constituted by a field, and at least one subfield group composed of two or more subfields continuous to one field period is provided. In the subfield group, writing is performed in the writing period of any subfield. A discharge cell that did not generate a discharge starts from the subfield to the last subfield. The address discharge is not generated in the address period up to and a part of each scan pulse does not overlap with a part of the other scan pulse in the address period of the subfield not belonging to the subfield group. In addition, in the writing period of the subfield belonging to the subfield group, a part of each scanning pulse overlaps with a part of other scanning pulses in time. By this method, it is possible to provide a panel driving method capable of shortening the writing time without deteriorating the image display quality and enabling the image display in which the pseudo contour does not easily occur.

  In the present invention, it is preferable that a subfield subsequent to the subfield group among subfields not belonging to the subfield group further includes an initializing period in which initializing discharge is generated in all the discharge cells displaying an image. By this method, crosstalk at the time of writing can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to shorten the writing time without deteriorating the image display quality, and to provide a panel driving method that enables image display in which pseudo contour is unlikely to occur.

  Hereinafter, a panel driving method according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is an exploded perspective view showing a main part of a panel used in the embodiment of the present invention. The panel 10 is configured such that a glass front substrate 21 and a rear substrate 31 are arranged to face each other and a discharge space is formed therebetween. On the front substrate 21, a plurality of scanning electrodes 22 and sustaining electrodes 23 constituting display electrodes are formed in parallel with each other. A dielectric layer 24 is formed so as to cover the scan electrodes 22 and the sustain electrodes 23, and a protective layer 25 is formed on the dielectric layer 24. A plurality of data electrodes 32 covered with an insulating layer 33 are provided on the back substrate 31, and a grid-like partition wall 34 is provided on the insulating layer 33. A phosphor layer 35 is provided on the surface of the insulator layer 33 and the side surfaces of the partition walls 34. The front substrate 21 and the rear substrate 31 are arranged to face each other so that the scan electrode 22 and the sustain electrode 23 and the data electrode 32 intersect each other, and in the discharge space formed therebetween, for example, neon And a mixed gas of xenon. Note that the structure of the panel is not limited to the above-described structure, and for example, a structure having a stripe-shaped partition may be used.

FIG. 2 is an electrode array diagram of the panel according to the embodiment of the present invention. In the row direction, n scan electrodes SC _{1 to} SC _n (scan electrode 22 in FIG. 1) and n sustain electrodes SU _{1 to} SU _n (sustain electrode 23 in FIG. 1) are arranged, and m scan electrodes are arranged in the column direction. Data electrodes D _{1 to} D _m (data electrodes 32 in FIG. 1) are arranged. A discharge cell is formed at a portion where a pair of scan electrode SC _i and sustain electrode SU _i (i = 1 to n) intersects with one data electrode D _j (j = 1 to m). M × n are formed in the discharge space.

FIG. 3 is a circuit block diagram of a plasma display device for implementing the panel driving method according to the embodiment of the present invention. The plasma display device includes a panel 10, an image signal processing circuit 51, a data electrode drive circuit 52, a scan electrode drive circuit 53, a sustain electrode drive circuit 54, a timing generation circuit 55, and a power supply circuit (not shown). The image signal processing circuit 51 converts the image signal sig into image data corresponding to the number of pixels of the panel 10, divides the image data of each pixel into a plurality of bits corresponding to a plurality of subfields, and outputs the divided data to the data electrode driving circuit 52. To do. Data electrode driving circuit 52 converts the signals corresponding to image data of each subfield to each of the data electrodes D ₁ to D _m for driving the data electrodes D ₁ to D _m. The timing generation circuit 55 generates a timing signal based on the horizontal synchronization signal H and the vertical synchronization signal V, and supplies the timing signal to each drive circuit block. Scan electrode drive circuit 53 supplies drive waveforms to scan electrodes SC _{1 to} SC _n based on the timing signals, and sustain electrode drive circuit 54 supplies drive waveforms to sustain electrodes SU _{1 to} SU _n based on the timing signals.

  Next, a driving voltage waveform for driving the panel and its operation will be described. In the present embodiment, one field is divided into 12 subfields (first SF, second SF,..., Twelfth SF), and the all-cell initializing operation is performed in the initializing period of the first SF. In the initializing period of the subfield, the contrast is improved by performing the selective initializing operation. The luminance weights of the first to fifth SFs are set to “1”, “2”, “4”, “8”, and “16”, respectively, and the luminance weights of the sixth to twelfth SFs are all “32”. "Is set.

  FIG. 4 is a diagram showing a relationship (hereinafter, abbreviated as “coding”) indicating in which subfield the discharge cell emits light in order to display a certain gradation in the embodiment of the present invention. In each of the first SF to fifth SF subfields, gradations “1” to “31” are displayed by controlling each discharge cell to emit light randomly or not emit light for each subfield. On the other hand, the sixth SF to the twelfth SF constitute a subfield group that is controlled so that the discharge cells emit light continuously. In this subfield group, the discharge cells that have been controlled so as not to emit light after that are sub Control is performed so that light is not continuously emitted until the last subfield of the field group. That is, a discharge cell that did not generate an address discharge in the address period of any subfield belonging to this subfield group generates an address discharge in the address period from that subfield to the last subfield belonging to the subfield group. I won't let you. For example, the discharge cells that did not emit light in the sixth SF do not emit light in the subsequent seventh SF to the twelfth SF, and the discharge cells that emit light in the sixth SF to the ninth SF but not the tenth SF are the eleventh SF and the twelfth SF. Do not fire. In this way, by controlling the discharge cells that have been controlled so as not to emit light once in the sixth SF to the 12th SF so as not to emit light continuously until the last subfield of the subfield group, “0”, “32”, Each gradation of “64”, “96”, “128”, “160”, “192”, “224” can be displayed.

  An arbitrary gradation of “0” to “255” can be displayed by combining the gradation displayed using the first SF to the fifth SF and the gradation displayed using the sixth SF to the twelfth SF. .

  In the present invention, the configuration and coding of the subfields are not limited to those described above, and the discharge cells that have been controlled so as not to emit light do not emit light continuously until the last subfield of the subfield group. The present invention can be applied to any subfield configuration having subfield groups to be controlled as described above.

  FIG. 5 is a diagram showing a driving voltage waveform applied to each electrode of the panel in the embodiment of the present invention. First, drive voltage waveforms in the first to fifth SFs will be described.

In a 1SF initialization period, first, in the first half, the data electrodes _D 1 to D _m and sustain electrodes _SU 1 to SU _n held to 0V, and the discharge start voltage or less with respect to the scan electrodes _SC 1 to SC _n and A ramp voltage that gradually rises from the voltage Vi ₁ to the voltage Vi ₂ that exceeds the discharge start voltage is applied. Then, cause weak initializing discharge in all the discharge cells, the scan electrodes _SC 1 to SC _n negative wall voltage on is accumulated, the positive sustain electrode _SU 1 to SU _n and the data electrodes _D on 1 to D _m The wall voltage is accumulated. Here, the wall voltage on the electrode refers to a voltage generated by wall charges accumulated on the dielectric layer covering the electrode, the phosphor layer, or the like.

Applying in the second half portion, maintaining the sustain electrodes _SU 1 to SU _n to a positive voltage Ve1, a ramp voltage that gently decreases from voltage Vi ₃ to the voltage Vi ₄ to the scan electrodes _SC 1 to SC _n subsequent initialization period To do. Then, a weak initializing discharge is caused again in all the discharge cells, the wall voltage between scan electrodes SC _{1 to} SC _n and sustain electrodes SU _{1 to} SU _n is weakened, and data on data electrodes D _{1 to} D _m The wall voltage is adjusted to a value suitable for the write operation. Thus, the all-cell initialization operation is performed in the initialization period of the first SF.

In a 1SF address period, applying a voltage Ve2 once the voltage Vc is applied to scan electrodes _SC 1 to SC _n sustain electrodes _SU 1 to SU _n. Then, while applying a negative scan pulse voltage Va to scan electrodes SC ₁ of the first row, the data electrode _D k of the discharge cells to be lit in the first row among data electrodes _D 1 ~D _m (k = _1~ A positive write pulse voltage Vd is applied to m). Then, address discharge occurs between data electrode D _k and between sustain electrode SU ₁ and scan electrodes SC ₁ and the scan electrodes SC _1, positive wall voltage on scan electrodes SC ₁ of the discharge cell, sustain electrodes negative wall voltage is accumulated on SU _1. In this way, the address operation is performed in which the address discharge is caused in the discharge cell to emit light in the first row and the wall voltage is accumulated on each electrode. On the other hand, no address discharge occurs at the intersection between the data electrode D _h (h ≠ k) and the scan electrode SC _{1 to} which the address pulse voltage Vd is not applied.

Then, return scan electrodes SC ₁ of the first row to the voltage Vc, is applied with scan pulse voltage Va in the second row to the scan electrodes SC _2, be emitted in the second row among data electrodes _D 1 to D _m An address pulse voltage Vd is applied to the data electrode _Dk of the power discharge cell. Then, an address operation is performed in which the address discharge is caused in the discharge cell to emit light in the second row and the wall voltage is accumulated on each electrode. The above address operation is sequentially performed until the discharge cell in the nth row, and the address period ends.

Here, the timing of the scan pulse waveform is set so that the scan pulses applied to the scan electrodes SC _{1 to} SC _n do not overlap in time. FIG. 6 is a drive waveform diagram showing details of the scan pulse waveform in the embodiment of the present invention. FIG. 6A is a drive waveform showing details of the scan pulse waveform in the write period of the subfield not belonging to the subfield group. FIG. Thus, a gap of time T1 is provided between the scan pulses so that the scan pulse applied to the i-th scan electrode SC _i and the scan pulse applied to the (i + 1) -th scan electrode SC _{i + 1} do not overlap in time. Yes. Although details of this will be described later, this is to prevent the address discharge of the adjacent discharge cells from crosstalking during the address period to prevent normal address discharge and prevent normal image display. In this embodiment, T1 = 0.1 μs is set. However, it is sufficient that the scanning pulses do not overlap each other, for example, T1 = 0.

Continues in the first 1SF the sustain period, return the sustain electrodes _SU 1 to SU _n to 0V, and sustain pulse voltage Vs is applied to scan electrodes _SC 1 to SC _n. In the discharge cell in which the address discharge has occurred at this time, the voltage between scan electrode SC _i and sustain electrode SU _i is equal to sustain pulse voltage Vs, and the magnitude of the wall voltage on scan electrode SC _i and sustain electrode SU _i. Exceeds the discharge start voltage. Then, a sustain discharge occurs between scan electrode SC _i and sustain electrode SU _i to emit light. At this time, a negative wall voltage is accumulated on scan electrode SC _i , and a positive wall voltage is accumulated on sustain electrode SU _i . Then return the scan electrodes _SC 1 to SC _n to 0V, and sustain pulse voltage Vs is applied to sustain electrodes _SU 1 to SU _n. Then, in the discharge cell having undergone the sustain discharge, sustain discharge occurs between the sustain electrode SU _i again sustain electrode SU _i and the voltage exceeds the discharge start voltage between the scan electrodes SC _i and the scanning electrode SC _i Occurs, a negative wall voltage is accumulated on the sustain electrode SU _i , and a positive wall voltage is accumulated on the scan electrode SC _i . Thereafter, in the same manner, by applying the number of sustain pulses proportional to the luminance weight to the scan electrodes SC _{1 to} SC _n and the sustain electrodes SU _{1 to} SU _n , the sustain discharge occurs in the discharge cells that have caused the address discharge in the address period. Will continue. Note that a sustain discharge does not occur in a discharge cell in which no address discharge has occurred in the address period, and the wall voltage at the end of the initialization period is maintained. Thus, the maintenance operation in the maintenance period is completed.

In setup periods of the subsequent third 2SF, sustain electrodes _SU 1 to SU _n to a voltage Ve1, respectively hold the data electrodes _D 1 to D _m to 0V, and the voltage Vi3 'to voltage Vi4 to the scan electrodes _SC 1 to SC _n Apply a ramp voltage that gradually falls. Then, a weak initializing discharge is generated in the discharge cell in which the sustain discharge is performed in the sustain period of the previous subfield, the wall voltage on scan electrode SC _i and sustain electrode SU _i is weakened, and on data electrode D _k . The wall voltage is also adjusted to a wall voltage suitable for the writing operation. On the other hand, the initializing discharge does not occur in the discharge cells where the address discharge and the sustain discharge are not performed in the previous subfield. Thus, the selective initialization operation is performed in the initialization period of the second SF.

  In the subsequent writing period of the second SF, the same operation as that of the first SF is performed, and in the sustain period, the same operation as that of the first SF is performed except for the number of sustain pulses. Also, in the third to fifth SFs, the same operation as that of the second SF is performed except for the number of sustain pulses in the sustain period, and thus detailed description thereof is omitted.

  Next, driving in the sixth SF to the twelfth SF constituting the subfield group will be described.

The initialization period of the sixth SF is the same as the initialization period of the second SF. That is, maintaining the sustain electrodes _SU 1 to SU _n to a positive voltage Ve1, and a ramp voltage that gently decreases from voltage Vi3 'to voltage Vi4 to the scan electrodes _SC 1 to SC _n. Then cause an initializing discharge in the discharge cells where the sustain discharge has occurred in the immediately preceding sub-field, scan electrodes _SC 1 to SC _n, the wall voltage on sustain electrodes _SU 1 to SU _n and the data electrodes _D 1 to D _m is a write operation It is adjusted to a value suitable for.

In the address period of the sixth SF, and applies the voltage Ve2 once the voltage Vc is applied to scan electrodes _SC 1 to SC _n sustain electrodes _SU 1 to SU _n. Then, while applying a negative scan pulse voltage Va to scan electrodes SC ₁ of the first row, the data electrode _D k of the discharge cells to be lit in the first row among data electrodes _D 1 ~D _m (k = _1~ A positive write pulse voltage Vd is applied to m). Then, the write operation of accumulating wall voltage on the write discharge occurs on each electrode during and between the sustain electrode SU ₁ and the scan electrodes SC ₁ to the data electrode D _k and scan electrodes SC ₁ is performed. On the other hand, no address discharge occurs at the intersection of the write pulse voltage Vd data electrode D _h applied with no scan electrode SC _1.

Next, the scan electrodes SC ₁ of the first row before returning to the voltage Vc, is applied with scan pulse voltage Va in the second row to the scan electrodes SC _2, the second row among data electrodes _D 1 to D _m An address pulse voltage Vd is applied to the data electrode _Dk of the discharge cell to emit light. And then returned to the scan electrodes SC ₁ of the first row to the voltage Vc. Then, an address operation is performed in which the address discharge is caused in the discharge cell to emit light in the second row and the wall voltage is accumulated on each electrode. The above address operation is sequentially performed until the discharge cell in the nth row, and the address period ends.

Here, the operation in the address period of the first SF is different from the operation in the address period in the first SF to the fifth SF. A part of each scan pulse sequentially applied to each of the scan electrodes SC _{1 to} SC _n is another scan pulse. The timing of the scanning pulse waveform is set so as to overlap with a part of the time. FIG. 6B is a drive waveform diagram showing details of the scan pulse in the address period of the subfield belonging to the subfield group. Thus, as the scan pulse overlap during time T2 to be applied to the scan pulse and the i-th scan electrode SC _i to be applied to the i-1 th scan electrode SC _i-1, i-th scan electrode SC _i Is set so that the scan pulse applied to _{i + 1} and the scan pulse applied to the (i + 1) th scan electrode SC _{i + 1} overlap each other during time T2. In this way, the writing time can be shortened by temporally overlapping a part of the scan pulses sequentially applied to each of the scan electrodes SC _{1 to} SC _n . Although details will be described later, in the subfield group for which continuous lighting control is performed, the address discharge of the adjacent discharge cells does not crosstalk in the address period even if a part of the scan pulse is overlapped.

In the subsequent sustain period of the sixth SF, similarly to the initial period of the first SF, the number of sustain pulses proportional to the luminance weight is alternately applied to the scan electrodes SC _{1 to} SC _n and the sustain electrodes SU _{1 to} SU _n. As a result, the sustain discharge is continuously performed in the discharge cells that have caused the address discharge in the address period. Note that a sustain discharge does not occur in a discharge cell in which no address discharge has occurred in the address period, and the wall voltage at the end of the initialization period is maintained. Thus, the maintenance operation in the maintenance period is completed.

  Since the initialization period of the seventh SF is the same as the initialization period of the sixth SF, description thereof is omitted.

In the subsequent address period of the seventh SF, similarly to the address period of the sixth SF, the timing of the scan pulse waveform is set so that a part of the scan pulses sequentially applied to the scan electrodes SC _{1 to} SC _n overlap. That is, as shown in FIG. 6B, the scan pulse applied to the i-th scan electrode SC _i and the scan pulse applied to the i + 1-th scan electrode SC _{i + 1} are set to overlap during time T2. , Writing time is shortened.

  Since the seventh SF is a subfield belonging to the subfield group, the discharge cells that perform the address discharge are limited to the discharge cells that have performed the address discharge also in the immediately preceding subfield, that is, the sixth SF. In other words, no address discharge occurs in the discharge cells that did not cause the address discharge in the sixth SF.

In the subsequent sustain period of the seventh SF, as in the sustain period of the sixth SF, the number of sustain pulses proportional to the luminance weight is alternately applied to the scan electrodes SC _{1 to} SC _n and the sustain electrodes SU _{1 to} SU _n . Then, in the discharge cell that has caused the address discharge in the address period of the seventh SF, a sustain discharge occurs between the scan electrode SC _i and the sustain electrode SU _i and emits light.

In the subsequent eighth SF to twelfth SF, the same operation as in the seventh SF is performed. Particularly in the address period, the timing of the scan pulse waveform is set so that a part of the scan pulse sequentially applied to each of the scan electrodes SC _{1 to} SC _n overlaps. Further, the discharge cells that perform the address discharge are limited to the discharge cells that have performed the address discharge in the immediately preceding subfield. As a result, in the continuous light emission subfield group of the sixth SF to the twelfth SF, the discharge cells that are once controlled to be non-light emission are controlled so as not to continuously emit light until the last subfield of the subfield group. It will be.

  The initialization period of the first SF of the next field is a subfield following the subfield group among the subfields not belonging to the subfield group. In the initialization period of the subfield that satisfies this condition, the all-cell initialization operation is performed as described above.

  Next, in the writing period of the subfield not belonging to the subfield group, each of the scanning pulses is set so as not to overlap in time, and in the writing period of the subfield belonging to the subfield group, each scanning pulse is set. The reason why a part is set so as to overlap with a part of another scanning pulse in time will be described.

  First, crosstalk that may occur during a write operation will be described. Crosstalk is a phenomenon in which an address discharge does not occur in a certain subfield, and a discharge cell in which an address discharge has occurred in an adjacent discharge cell cannot perform an address discharge in the subsequent subfield address period. There are still many points about the mechanism of its occurrence, but it can be considered as follows. In the address period, charged particles flying from adjacent discharge cells that have been subjected to the address discharge immediately before the scan pulse is applied neutralize the wall voltage between the data electrode and the scan electrode. As a result, it can be considered that the wall voltage is insufficient in the subsequent sub-field write period, causing a write failure. Since neutralization of the wall voltage occurs in the state where an electric field is applied to the discharge space, in order to prevent crosstalk, the electric field is not applied to the discharge space while the charged particles fly. It is not necessary to apply a scan pulse.

In the present embodiment, in order to suppress crosstalk in the writing periods of the first SF to the fifth SF that do not belong to the subfield group, the scan pulses applied to the scan electrodes SC _{1 to} SC _n do not overlap each other. The timing of the scanning pulse waveform is set. On the other hand, in the sixth SF to the twelfth SF belonging to the subfield group, even if the wall voltage for the address discharge is insufficient in the discharge cells that are once controlled to emit no light, the last subfield of the subfield group is displayed. Since there is no continuous light emission up to the field, there is no opportunity for crosstalk. Therefore, the timing of the scan pulse waveform is set so that a part of the scan pulse sequentially applied to each of the scan electrodes SC _{1 to} SC _n overlaps to shorten the writing time.

  However, if the time for overlapping a part of the scan pulse is too long, a malfunction may occur in which an address discharge occurs in a discharge cell in which no address is performed. Experimentally, this malfunction occurred when T2> 0.4 μs. Therefore, it is desirable to set the time T2 for overlapping a part of the scanning pulse to 0.4 μs or less. In this embodiment, since T2 = 0.2 μs and the number of scan pulses applied sequentially = 384, the writing period of one subfield can be shortened by 0.2 μs × 384 line = 76.8 μs. Since the continuous light emission subfield group is composed of seven subfields, it is possible to shorten the writing time of 76.8 μs × 7SF = 537.6 μs per field.

  In the present embodiment, it has been described that the all-cell initialization operation is performed in the initialization period of the first SF and the selective initialization operation is performed in the initialization period of the other subfields. Even in the 12SF initialization period, the all-cell initialization operation can be performed as necessary. For example, the initialization operation of the first subfield of the continuous light emission subfield group may be the all-cell initialization operation. However, in the subfields that do not belong to the subfield group, the subfield that follows the subfield group may cause crosstalk at the time of writing. In this case, the all-cell initialization operation may be performed in the initialization period. desirable.

  Further, in the embodiment of the present invention, the description has been given on the assumption that among the plurality of subfields constituting one field, the sixth to twelfth SFs, which are the latter subfields, constitute a subfield group. The subfields constituting the subfield group are not limited to the above. For example, one field is divided into 14 subfields (first SF, second SF,..., 14th SF), and the luminance weight of each subfield is (1, 2, 4, 8, 16, 32, 32, 4, 8, 16, 32, 32, 32, 32), the fifth SF and the sixth SF constitute the first subfield group, and the eleventh SF to the fourteenth SF constitute the second subfield group. The present invention can be applied even if it is. In this case, it is desirable to perform the all-cell initializing operation in the subfield following the subfield group among the subfields not belonging to the subfield group, that is, in the initializing period of the first SF and the seventh SF.

  The present invention is useful as a panel driving method because the writing time can be shortened without deteriorating the image display quality and the image display in which the pseudo contour is hardly generated can be realized.

The disassembled perspective view which shows the principal part of the panel used for embodiment of this invention. Electrode arrangement of the panel Circuit block diagram of plasma display device for implementing the panel driving method The figure which shows the coding used for embodiment of this invention The figure which shows the drive voltage waveform applied to each electrode of the panel used for embodiment of this invention Drive waveform diagram showing details of scan pulse applied to scan electrode of panel

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Panel 22 Scan electrode 23 Sustain electrode 32 Data electrode 51 Image signal processing circuit 52 Data electrode drive circuit 53 Scan electrode drive circuit 54 Sustain electrode drive circuit 55 Timing generation circuit

Claims (2)

A method of driving a plasma display panel in which discharge cells are formed at intersections of scan electrodes, sustain electrodes, and data electrodes,
An address period in which a scan pulse is sequentially applied to the scan electrodes and an address pulse is selectively applied to the data electrodes to selectively generate an address discharge in the discharge cells, and an address discharge is selectively performed in the address period. A plurality of subfields each having a sustain period for generating a sustain discharge for causing the generated discharge cells to emit light constitutes one field period, and the subfield is composed of two or more subfields consecutive in one field period At least one group is provided, and in the subfield group, discharge cells that did not generate an address discharge in the address period of any of the subfields perform an address discharge in the address period from the subfield to the last subfield. Configured to not generate,
In addition, in the address period of the subfield not belonging to the subfield group, a part of each scan pulse is configured not to overlap with a part of another scan pulse in time,
A method for driving a plasma display panel, wherein a part of each scanning pulse overlaps with a part of another scanning pulse in a writing period of a subfield belonging to the subfield group. The subfield subsequent to the subfield group among the subfields not belonging to the subfield group further includes an initializing period in which initializing discharge is generated in all discharge cells displaying an image. 2. A driving method of a plasma display panel according to 1.

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