JP3259713B2 - Driving method and driving apparatus for plasma display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for driving a plasma display panel, and more particularly, to a high-contrast information display terminal, a flat-panel television, etc., used for a color plasma display panel having a high definition and a large display capacity. The present invention relates to a method and an apparatus for driving a plasma display panel to be realized.

[0002]

2. Description of the Related Art Conventionally, a driving method and a driving apparatus of a plasma display panel generally perform a display operation by exciting visible light by exciting a phosphor with ultraviolet rays generated by gas discharge. Further, it can be classified into an AC type and a DC type according to a discharge method. An AC type is shown below as a conventional example. In the case of the AC type, there are mainly a two-electrode opposed discharge type and a three-electrode surface discharge type. Since a three-electrode type is excellent as a structure of a color plasma display panel, a three-electrode surface discharge type is taken as an example here. However, the present invention can be applied to any of an AC type and a DC type. In FIG. 8, which shows a cross-sectional configuration example of a three-electrode AC surface discharge type plasma display panel,
A transparent electrode 41 is formed on the front substrate 40 as a scanning electrode for performing surface discharge and a fiber electrode. The transparent electrode 41 is usually
It is formed of TO or SnO ₂ . However, since the sheet resistance is high, the pass electrode 42 is formed of, for example, an aluminum thin film, a thin film having a three-layer structure of chromium / copper / chromium, or a thick film of silver. This is covered with a transparent insulating layer 43 made of low melting point lead glass. This is formed by thick film printing. Further, black partition walls 45 are formed by thick film printing. These surfaces are covered with a protective layer 44.

The protective layer 44 is formed by electron beam evaporation of a Mg0 thin film. A data electrode 48 is formed of a thin aluminum film or a thick silver film on the rear substrate 49 and is covered with a white insulating layer 47.
In this method, a mixture of low melting point lead glass and titanium oxide or alumina powder as a white pigment is formed by thick film printing. Further, a white partition wall 46 is formed by thick film printing. The phosphor 50 is formed on the surface of the white insulating layer 47 and the side surface of the white partition 46 by thick-film printing. Then, the transparent electrode 41 formed on the front substrate 40 and the data electrode 48 formed on the rear substrate 49 face each other and are perpendicular to each other, and are sealed together with two types of partitions 45 and 46. Dischargeable gas, for example, He, Ne,
A mixed gas such as Xe is sealed in at about 500 torr.

FIG. 9 shows a conventional example of a memory drive waveform of a three-electrode AC surface discharge type plasma display panel. Every other transparent electrode 41 is a scan electrode and a sustain electrode. That is, one scan electrode and one sustain electrode are arranged in one discharge cell divided by the partition. The sustain pulse 7 is applied between the adjacent transparent electrodes 41 (scanning electrode and sustain electrode).
2 and 73 are applied to generate surface discharge to perform display discharge.
The display data is written by applying a scan pulse 74 to the scan electrode.
This is performed by applying a data pulse 75 to the data electrode to generate a write discharge between the scan electrode and the data electrode. FIG. 9 shows a case where data is written to the (n + 1) th scanning electrode. At this time, the scan pulse 74, the sustain pulse 72 and the sustain pulse 73 are negative voltage pulses, whereas the data pulse 75 applied to the data electrode is a positive voltage pulse. This is to prevent cations generated by the data writing discharge from damaging the phosphor.

The written data includes sustain pulses 72 and 7
The discharge is continued between three. This display discharge stops when a sustain discharge period to be described later ends and no sustain voltage is applied. When the plasma display panel has a large display capacity, the number of scanning electrodes increases, and the access time per scanning electrode decreases. Therefore, the time during which the scanning pulse can be applied is shortened. In order to surely generate a write discharge with a short scanning pulse, a priming discharge that causes charged particles to stay in the discharge cells may be generated before writing.

In the priming pulse 70 of FIG. 9, a sufficiently high voltage is applied to all the scanning electrodes so as to generate a priming discharge. Then, a priming erase pulse 71 is applied to erase wall charges generated by the priming discharge. Priming erase pulse 71
Applies a very dull waveform to ensure erasure. As a result, the charged particles stay in all the cells before the scan pulse is applied. The applied voltage of each pulse is, for example, a sustain pulse 150 V, a scan pulse 170
V, data pulse 70V, priming pulse 250
V, a priming erase pulse of 150 V.

FIG. 10 shows eight subfields (SF1).
ＳＦSF8), which is a sequence of 8 bits = 256 gradations, and shows examples of priming discharge timing, scanning timing, and sustain period during one field period. Each subfield is divided into a scanning period 60 and a sustain period 61. At the beginning of each subfield, a priming pulse is applied between all the scanning electrodes and the sustaining electrodes, and a priming discharge 63 is simultaneously generated on the entire screen. Thereafter, if there are n scan electrodes during the scan period 60, the n scan electrodes are sequentially scanned and data is written in the form of electric charges in each discharge cell. In the scanning period 60, the sustain period 61 is reached when the n-th scan is completed, and the sustain cells are applied with the sustain pulse and the discharge cells in which the data is written perform the sustain discharge. When the sustain period 61 ends, the sustain pulse ends, and the sustain discharge stops. Thereby, the first subfield (SF
1) is completed. Thereafter, similar scanning is performed for SF2 to SF8, and gradation display is performed by appropriately selecting these subfields.

[0008]

However, in the above-described conventional method and apparatus for driving a plasma display panel, priming discharge is generated at the beginning of each subfield over the entire screen of the panel, and then scanning is performed sequentially. This priming discharge is similarly performed at the beginning of all subfields. In the case of the above-described conventional example, one priming discharge discharges twice with a priming pulse and a priming erase pulse. If this operation is performed in eight subfields, light emission is always performed 16 times per field in total. In addition, the priming pulse has a higher voltage than the sustain pulse, and thus has a higher luminance. Therefore, even when there is no data on the entire panel, the panel emits whitish light, which is a so-called black floating state, which causes a problem that the contrast is significantly reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a driving method and a driving apparatus for a plasma display panel capable of displaying images with high contrast.

[0010]

In order to achieve the above object, a method of driving a plasma display panel according to the present invention performs gradation display using subfields and generates a priming discharge in at least one or more subfields. A plasma display panel driving method,
It is characterized in that a priming discharge is generated in a predetermined cell predetermined for at least one or more subfields.

The predetermined cell is a cell based on a count value obtained by counting display data for each subfield and a predetermined rule, and the priming discharge is applied to m scan electrodes. It is preferable that the priming discharges be generated every other or every m data electrodes and the total number of priming discharges in at least one field of each cell be substantially equal in all cells. Further, it is preferable that the priming discharge is generated alternately in the odd-numbered cells and the even-numbered cells of the scan electrodes for each subfield.

The above-described priming discharge is generated alternately in odd-numbered cells and even-numbered cells of the scan electrodes for each subfield, and the number of data in the subfield is counted. It is preferable that a discharge is generated, the number of data in the subfield immediately before the subfield is counted, and a priming discharge is generated in a cell having a small number of data.

The priming discharge is generated in the sub-fields of the odd-numbered scan electrodes and the even-numbered scan electrodes in the sub-fields by generating a priming discharge in the cell corresponding to the larger number of counted scan electrodes. The number of data in the immediately preceding subfield is counted, and a priming discharge is preferably generated in the cell corresponding to the scan electrode having the smaller counted data in the cells corresponding to the odd-numbered scan electrodes and the cells corresponding to the even-numbered scan electrodes.
Another method of driving a plasma display panel according to the present invention is a method of driving a plasma display panel that performs gradation display using a subfield and generates a priming discharge in at least one or more subfields.
A priming discharge step of generating a priming discharge by applying a priming pulse to every first (m is a natural number of 1 or more) scan electrode or data electrode first cell group along the scan electrode or data electrode; Applying a sub-pulse having a lower voltage value than the priming pulse to the second cell group different from the priming pulse to the second cell group, wherein the charged particles generated by the priming of the first cell group are discharged to the second cell group. Are attracted to the cell group.

The voltage value of the sub-pulse is a weak discharge priming pulse formed with a value equal to or higher than the occurrence of the priming discharge, and the second cell group generates a weaker priming discharge than the first cell group. May be replaced for each subfield.

Further, a method of generating a priming discharge in at least one or all of the cells of the plasma display panel is selected and used.
In this selection, the priming discharge may be generated in all the cells in the subfield having the higher luminance weight. A driving apparatus for a plasma display panel according to the present invention performs gradation display using subfields and generates a priming discharge in n (n is a natural number of 1 or more) divided subfields. It has two or more driving means for driving the subfield, and generates a priming discharge in a predetermined cell.

Further, another plasma display panel driving device performs gradation display using a subfield,
A driving apparatus for a plasma display panel for generating a priming discharge in at least one or more subfields, wherein every first (m is a natural number of 1 or more) scan electrodes or data electrodes is arranged along a scan electrode or a data electrode.
A priming discharge means for generating a priming discharge by applying a priming pulse to the second cell group; and applying a sub-pulse having a lower voltage value than the priming pulse to the second cell group to a second cell group different from the first cell group. And sub-pulse applying means for attracting charged particles generated by priming of the first cell group to the second cell group.

Therefore, according to the method and apparatus for driving a plasma display panel of the present invention, at least one
A priming discharge is generated in predetermined cells in each of at least one subfield. Therefore, it is possible to generate a priming discharge of a cell predetermined for each subfield.

According to another method and apparatus for driving a plasma display panel, priming is performed by applying a priming pulse to a first cell group every m scan electrodes or data electrodes along a scan electrode or data electrode. A discharge is generated, and a sub-pulse having a lower voltage value than the priming pulse is applied to a second cell group different from the first cell group. Therefore, charged particles generated by priming of the first cell group can be attracted to the second cell group.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a plasma display panel driving method and apparatus according to the present invention. 1 to 7 show an embodiment of a driving method and a driving apparatus of a plasma display panel according to the present invention.

Next, an embodiment of the present invention will be described with reference to a three-electrode AC surface discharge plasma display panel. Although the present embodiment is directed to a three-electrode AC surface discharge plasma display panel, the present invention can be applied not only to a two-electrode AC plasma display panel but also to a DC plasma display panel.

FIG. 1 shows an embodiment in which one field is divided into n subfields. In the present embodiment, the display area 1 includes a first subfield, a second subfield,
And a case where the lighting state of the priming discharge is configured in the n-th subfield. In FIG. 1, the description from the third subfield to the (n-1) th subfield is omitted.

In the first subfield, the priming discharge is generated only in the cell 2 for generating priming, that is, only in the small square portion in the drawing in the display area. In the second subfield, a priming discharge is generated in a different pattern from the first subfield. However, the first
It may overlap with the subfield. Hereinafter, priming discharge is generated in a predetermined pattern for each subfield. A priming effect is obtained for cells that do not generate priming discharge by diffusion of charged particles from nearby cells that have generated priming. According to the above procedure, the number of priming discharges is reduced, and the contrast is improved. Although FIG. 1 shows a checkered pattern, various patterns can be considered.

FIG. 2 is a block diagram showing a circuit configuration of a main part of a driving unit for controlling the plasma display panel of this embodiment. The drive unit of the embodiment is a signal processing circuit 1 that processes an input signal and outputs a drive signal.
1, a driving circuit 12 for driving a plasma display panel based on a driving signal, a plasma display panel 13 as a display panel, a data number counting circuit 14 for counting the number of data of the driving signal, and a priming pulse based on an output of the data number counting circuit. And a priming pulse generating circuit 15.

The driving unit for controlling the plasma display panel having the above-described configuration converts an input signal into a signal processing circuit 1
In step 1, data is converted into data for each subfield according to the luminance signal. Based on this, the drive circuit 12 generates a data pulse. The data number counting circuit 14 counts the number of data for each subfield created by the signal processing circuit 11. A priming pulse generation circuit 15 generates a priming pulse based on the counted data based on a predetermined rule, and applies the priming pulse to the plasma display panel 13. Thus, an efficient priming effect can be obtained with a small number of priming discharges.

FIG. 3 is an example of a drive waveform configuration showing the drive state of the present embodiment. This timing pulse indicates the timing of the voltage applied to the sustain electrode, scan electrode n, scan electrode n + 1, scan electrode n + 2, scan electrode n + 3, and data electrode.

FIG. 3 shows a case where the electrode spacing m = 1, in which priming discharges are generated simultaneously every m lines. In other words, at the beginning of each subfield, cells are divided into odd-numbered and even-numbered scanning electrodes, and priming discharge is generated alternately for each subfield. FIG.
, And a priming discharge is generated at the n + 2, n + 4, n + 6,. At this time, the priming effect is slightly weaker in the cells during this period, that is, the scan electrodes n + 1, n + 3, n + 5,. Thus, the priming effect can be enhanced by applying the charged particle attracting pulse 24 as a sub-pulse to attract a part of the charged particles generated by priming generated in the adjacent cell. At this time, since the discharge is not performed by the charged particle attraction pulse, the contrast is the same as the case where the priming discharge is performed every other line. The charged particle attraction pulse 24 may be applied almost simultaneously with the application timing of the priming pulse 20, or between the application of the priming pulse 20 and the application of the scanning pulse 25.
Although FIG. 3 shows a diagram in which a negative-polarity charged particle attracting pulse is applied to attract positive ions, a positive-polarity pulse may be used. In this case, electrons are attracted. The same applies to the case where the electrode interval m is 2 or more. When the electrode interval m is 2 or more, the priming discharge can be performed in a sweep manner with n, n + 1, n + 2,...

The above embodiment has various variations. Examples of changes in the priming occurrence pattern are shown below. FIG.
Is a first variation example of the priming occurrence pattern. In this modification, priming is generated using a plurality of cells 4 belonging to the same scanning electrode as one unit in the display area. Cell 4 in FIG. 4 causes priming. Priming is generated in this one unit, for example, every other scanning electrode. According to this procedure, the priming luminance of the entire display area is halved. Every two, every three,
.., Every m lines, the priming luminance becomes smaller and the contrast is improved. However, since the effect of priming gradually decreases, the electrode spacing for generating priming is preferably determined based on the ease of movement of charged particles between cells of the panel, the ease of writing drive waveform data, and the like.

FIG. 5 shows a second variation of the priming occurrence pattern. In the second modification, a plurality of cells belonging to the same data electrode are used as one unit instead of the scanning electrode of the first modification. In this case as well, it is preferable to determine the number of cells in which priming occurs from every other data electrode to every mth data electrode based on the panel structure and driving method.

In the driving waveforms of the above-described embodiment and the modified example, the rules of the driving method are set so that the priming light emission counts of all the cells coincide, for example, when one field is completed. As a result, the number of times of priming light emission of each cell over the entire screen becomes equal, so that unevenness of contrast and uneven writing due to uneven priming can be eliminated. However, it is also possible to make the number of times of priming light emission coincide with each other in a plurality of fields. For example, if this is four fields, the number of times of priming light emission of each cell in the entire screen becomes equal every four fields.

FIG. 6 shows a case in which priming discharge is generated alternately for each subfield separately for cells corresponding to odd-numbered scan electrodes and cells corresponding to even-numbered scan electrodes. Of course, the same effect can be obtained even if the priming discharge is generated separately for the odd and even data electrodes. For example, the cells are divided into two groups based on a predetermined rule. The number of data to be written in the subfield for each of these two groups is counted. When a priming pulse is applied to the group having the larger number of data, data writing on the entire panel becomes better. As a result, a priming effect can be efficiently obtained with a small amount of priming discharge.

In another example, two cells are assigned based on a predetermined rule.
Into two groups. The number of data to be written in the subfield for each of these two groups is counted. A priming pulse is applied to the group with the smaller number of data in the next subfield. That is, a priming discharge is generated in the group having less data in the immediately preceding subfield. Since the priming effect remains in the cells once displayed and discharged until the next subfield, priming discharge is not generated in these cells as much as possible, so that the priming luminance can be reduced and the contrast can be increased.

The above-mentioned two groups are divided into cells corresponding to odd-numbered and even-numbered scanning electrodes, and priming discharges are generated alternately. Of course, this may be replaced with a data electrode.

FIG. 7 shows an example of a priming discharge timing, a scanning period, a sustain period, and a scanning timing during one field period. One field is 1/60 second ($ 16.
67 mSEC). The plasma display panel performs gradation display by a combination of subfields in which the luminance weight is changed. When priming discharge is generated every m scan electrodes, if m = 1, the priming discharge is alternately performed for each subfield at the beginning of each subfield by dividing the cells into odd-numbered and even-numbered scan electrodes. generate.

In FIG. 7, n, n + 2, n + 4, n + 6,... And a priming discharge are generated. At this time, the priming effect is slightly weaker in the cells during this period, that is, the scan electrodes n + 1, n + 3, n + 5,... Therefore, a weak discharge priming pulse 34 as a sub-pulse is applied. Since priming discharge occurred in adjacent cells,
In this cell, it is possible to generate a discharge at a voltage lower than the priming pulse 30. Since the voltage is low, the priming discharge is darker than the cell to which the priming pulse 30 is applied, and the contrast is improved. It is sufficient that the weak discharge priming pulse 34 is almost simultaneously with the application timing of the priming pulse 30. The same applies to the case where m = 2 or more.

In another variation, the priming pulse 20
Alternatively, the scanning electrodes to which 30 is applied are changed every subfield. As a result, a priming effect can be obtained uniformly over the entire panel, and the contrast can be made uniform.

In still another variation, each of the above driving methods is combined for each subfield. This combination includes a conventional method of generating a priming discharge in all cells. There is also a method of combining according to the luminance weight of the subfield. Since a subfield having a high luminance weight has a large effect when insufficient writing occurs, a priming discharge is generated in all cells. For subfields with low weight, the methods are appropriately combined with priority given to contrast.

With the above-described driving method of the plasma display panel, it is possible to reduce the priming luminance and greatly improve the contrast while keeping the priming effect at a level close to the conventional method. An object of the present invention is to reduce the number of cells that generate a priming discharge. Therefore, various variations are possible. If the above method is appropriately selected according to the contents displayed on the display, the effect obtained can be enhanced. It is also effective to switch the priming method using, for example, a TV moving image signal or computer data on the same display according to an input signal.

Although the above embodiment is an example of a preferred embodiment of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

[0038]

As is apparent from the above description, the driving method and driving apparatus for a plasma display panel according to the present invention generate a priming discharge in a predetermined cell for each of at least one or more subfields. . Therefore, a priming discharge of a predetermined cell is generated for each subfield, and a priming discharge of other cells is not generated. As a result, the number of times of priming discharge can be reduced as a whole, and the display contrast can be increased.

According to another method and apparatus for driving a plasma display panel, priming is performed by applying a priming pulse to the first cell group every m scan electrodes or data electrodes along the scan electrodes or data electrodes. A discharge is generated, and a sub-pulse having a lower voltage value than the priming pulse is applied to a second cell group different from the first cell group. Therefore, charged particles generated by priming of the first cell group can be attracted to the second cell group, and the priming effect can be enhanced and the contrast can be increased.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of a display area of an embodiment of a driving method and a driving apparatus of a plasma display panel according to the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a driving unit that drives the plasma display panel of FIG.

FIG. 3 is a driving waveform showing a driving procedure of a plasma display panel used in one embodiment of the embodiment.

FIG. 4 is a diagram showing a modification example of FIG. 1;

FIG. 5 is a diagram showing a modification example of FIG. 1;

FIG. 6 is a diagram showing a modification example of FIG. 1;

FIG. 7 is a diagram showing a modification of FIG. 3;

FIG. 8 is a cross-sectional view illustrating a configuration example of a conventional plasma display panel.

FIG. 9 is a driving waveform showing a driving procedure example of a conventional plasma display panel.

FIG. 10 is a diagram showing an example of a subfield driving configuration of a conventional plasma display panel.

[Explanation of symbols]

 Reference Signs List 1 display area 2 cell generating priming 3 display area 4 cell generating priming 5 display area 6 cell generating priming 7 display area 8 cell corresponding to odd-numbered scanning electrode. 9 Cell corresponding to even-numbered scan electrode 20 Priming pulse 21 Priming erase pulse 22 Sustain pulse 23 Sustain pulse 24 Charged particle attraction pulse 25 Scan pulse 26 Data pulse 30 Priming pulse 31 Priming erase pulse 32 Sustain pulse 33 Sustain pulse 34 Weak discharge priming pulse Reference Signs List 35 scanning pulse 36 data pulse 40 front substrate 41 transparent electrode 42 bus electrode 43 transparent green layer 44 protective layer 45 black partition 46 white partition 47 white insulating layer 48 data electrode 49 rear base slope 50 phosphor

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G09G 3/28 G09G 3/20 641 G09G 3/20 642 H01J 11/00 H01J 11/02

Claims (5)

(57) [Claims] 1. A performs gray-scale display using a subfield, in a driving method of a plasma display panel for generating the priming discharge, divided more cells into two groups, the plug before the occurrence of the priming discharge
The display data of the subfield that causes the
The number of cells to which data is written is counted for each group and displayed.
Cells in the group with the larger number of cells to write data
A priming discharge is generated in the plasma display panel. 2. A gradation display using a subfield.
There, plasma display to generate a priming discharge
In the panel driving method , all display cells are divided into two groups.
Divided into over-flops, the plastic prior to the occurrence of the priming discharge
Immediately before the subfield in which the imming discharge occurs
The number of cells in which the display data of the
It counted for each group, a small number of cells for writing display data
Priming discharge occurs in cells of the group with no
Of a plasma display panel characterized by
Drive method. 3. The two groups are odd-numbered scanning electrodes.
Note that this is a cell corresponding to the eye and a cell corresponding to the even number.
The plasma display panel according to claim 1,
Drive method. 4. The two groups are odd-numbered scanning electrodes.
Note that this is a cell corresponding to the eye and a cell corresponding to the even number.
3. The plasma display panel according to claim 2,
Drive method. 5. A driving apparatus for a plasma display panel which performs gradation display using a subfield and generates a priming discharge in at least one or more subfields, wherein all display cells are divided into two groups. Generate the priming discharge before discharge occurs
To write the display data of the subfield to be generated.
It counts the Le number for each of the groups, writing display data
A driving apparatus for a plasma display panel, wherein a priming discharge is generated in cells of the group having a larger number of cells .