JP2002366092A - Plasma display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of an abnormal (erroneous) electric discharging caused by the reduction in a driving margin of a plasma display panel(PDP) used to display an image for a computer and a television set or the like and to realize a PDP having a superior picture quality. SOLUTION: In the driving method of a PDP, a pulse width PWn of a last sustaining pulse in a sustaining interval is made narrower than a pulse width PWn-1 of the prior sustaining pulses. Thus, abnormal electric discharging time during an erasing pulse applying for a PDP having a low discharging start voltage is suppressed. Moreover, by stably conducting an initialization operation and an address operation later, reduction in picture quality caused by an erroneous discharging is improved and a high quality and superior PDP is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel used for displaying images on a computer, a television, and the like, and an image display device using the same.

[0002]

2. Description of the Related Art A conventional PDP generally has a structure as shown in FIG.

In FIG. 1, a band-shaped electrode group 19a and a band-shaped electrode group 19b are formed on a front substrate 11, and the electrode groups 19a and 19b are covered with a dielectric glass layer 17 made of lead glass or the like. In addition, the surface of the dielectric glass layer 17 is covered with a protective layer 18 made of a vapor-deposited MgO film or the like.
A band-shaped data electrode group 14 and an insulator layer 13 made of lead glass or the like covering the surface are provided on the rear substrate 12, and a partition wall 15 is provided thereon. The front substrate 11 and the rear substrate 12 are combined so that respective electrode groups are orthogonal to each other. The partition 15 is adhered to the rear substrate 12 and is in contact with the front substrate 11. Normally, the front substrate 11 and the rear substrate 12 face each other and are sealed by the partition walls 15 at intervals of about 100 to 200 microns.

By selectively applying a voltage between the electrode groups 19a and 19b on the front substrate 11 and the data electrode group 14 on the rear substrate 12, the charge generated by the gas discharge at the intersection of the selected electrodes is reduced. By scanning the electrode that is accumulated on the dielectric glass insulating film 17 and to which a voltage is to be applied, 1
After an address operation for accumulating information of pixels for a screen, a sustain discharge operation for applying an AC pulse voltage between the electrode group 19a and the electrode group 19b on the front substrate 11 allows discharge cells selected in the address operation to be simultaneously performed. An image is displayed by emitting light. Since the discharge occurs in the space separated by the front substrate 11, the rear substrate 12, and the partition 15, the light emission does not diffuse. That is, the partition 15 has the purpose of defining the distance between the front substrate 11 and the rear substrate 12 and the purpose of performing high-resolution display.

[0005] In the case of performing color display, a phosphor 16 is applied to a peripheral portion of a discharge space which is blocked by a partition. Since the phosphor is formed by converting ultraviolet light generated by the discharge into visible light, three primary colors of red (R), green (G), and blue (B) are used, and the emission intensity of each is reduced. By appropriate adjustment, color display becomes possible.

As a discharge gas, in the case of a single color display, a mixed gas mainly composed of neon, which emits light in the visible region at the time of discharge, and in the case of a color display, the emission of light during discharge is in an ultraviolet region. A mixed gas centered on xenon is selected. The gas pressure assumes the use of PDP under atmospheric pressure,
Usually, the pressure inside the substrate is reduced to 2
It is set in the range of about 00 Torr to 500 Torr (26.6 kPa to 66.5 kPa). FIG. 2 shows an electrode matrix diagram of a conventional PDP.

Next, a conventional PDP driving method will be described with reference to FIGS.

FIG. 3 is a block conceptual diagram of an image display device using a conventional PDP, and FIG. 4 shows an example of a driving waveform applied to each electrode of the panel. In FIG. 4, first, an initialization pulse is applied to the electrode groups 19b1 to 19bN to initialize wall charges in the discharge cells of the panel. Next, a scan pulse is applied to the first electrode 19a1 of the electrode group 19a and the data electrode group 1
Lines 141 to 14 corresponding to discharge cells performing display of No. 4
A write pulse is simultaneously applied to M to perform a write discharge to accumulate wall charges on the surface of the dielectric layer. Next, the electrode group 19a
Scan pulse is applied to the second line electrode 19a2 of the line 14a corresponding to the discharge cell for displaying the data electrode group 14.
A write pulse is simultaneously applied to 1 to 14M to perform a write discharge to accumulate wall charges on the surface of the dielectric layer. Subsequently, similarly, a latent image for one screen is written by sequentially accumulating wall charges corresponding to cells to be displayed by continuous scanning on the surface of the dielectric layer.

Next, in order to perform a sustain discharge, the data electrode group 14 is grounded, and a sustain pulse is alternately applied to the electrode group 19a and the electrode group 19b. In this case, a discharge occurs when the potential on the dielectric surface exceeds the discharge start voltage, and the main discharge of the display cell selected by the write pulse is maintained during a period in which the sustain pulse is applied (sustain period). Thereafter, an incomplete discharge is generated by applying a narrow erasing pulse, and the wall charges disappear, so that erasing is performed.

When displaying a television image, the image is composed of 60 fields per second in the NTSC system. Originally, in a plasma display panel, only two gradations of lighting or extinguishing can be expressed, and in order to display an intermediate color, the lighting time of each color of red (R), green (G), and blue (B) is time-divided. A method is used in which one field is divided into several subframes, and an intermediate color is represented by a combination of the subframes. FIG. 5 shows a method of dividing a subfield when expressing 256 gradations for each color in a conventional AC-driven plasma display panel. The ratio of the number of sustain pulses applied during the discharge sustain period of each subfield is 1,
Weighting is performed in binary such as 2, 4, 8, 16, 32, 64, and 128, and 265 gradations are expressed by a combination of these 8 bits.

Further, by increasing the number of subfields to further improve the image quality and using a plurality of combinations of weighting of the subfields for displaying the gradation, a pseudo contour generated due to a movement of a line of sight in displaying a moving image. Has been used.

As described above, in the conventional PDP driving method, display is performed by a series of sequences including an initialization period, a writing period, a sustaining period, and an erasing period.

[0013]

However, in the above-mentioned conventional configuration, when the main discharge gap or the thickness of the dielectric layer is reduced to lower the discharge starting voltage, abnormal discharge (erroneous discharge) which is the upper limit of the driving margin is required. ) The generated voltage also drops,
There is a big problem that the driving margin is narrowed.

In the present invention, these problems are solved, the initializing discharge and the erasing discharge in the initializing period (setup period) for adjusting the wall voltage in the discharge cell are improved, and the driving margin is widened and stabilized. It is an object of the present invention to realize a high-definition and high-definition plasma display device which performs operation and has high image quality without erroneous discharge.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a discharge device comprising a plurality of opposing electrodes covered with a dielectric between a pair of parallel substrates, and a discharge wall formed by a phosphor having a phosphor formed on the surface. A plasma display panel which constitutes a cell, fills in a discharge gas and displays an image by gas discharge, and a setup unit,
What is claimed is: 1. A plasma display apparatus comprising a driving unit driven by a driving method having an address unit, a discharge sustaining unit and a discharge stopping unit, wherein the driving unit applies a pulse voltage to a first electrode group to perform initialization. Duration and
An address period in which a pulse voltage is applied to a selected electrode in the third electrode group while sequentially applying a pulse voltage to the first electrode group to accumulate wall charges in a dielectric layer at a selected location; The driving unit includes a sustain period in which a pulse voltage is applied between the first electrode group and the second electrode to maintain the discharge, and a discharge stop period in which the sustain discharge is stopped. It is assumed that a driving method is used in which the pulse width PWn of the pulse is smaller than the pulse width PWn-1 of another sustain pulse preceding it.

Further, in order to achieve the above object, the present invention provides a method for controlling the pulse width PWn of the last sustain pulse in the sustain period.
Is the pulse width PWn-1 of another sustain pulse preceding it.
And the pulse voltage applied during the initialization period is a positive pulse voltage, and the pulse PWe having a pulse width narrower than PWn-1 is applied to the first electrode group during the discharge stop period preceding the setup section. Is applied.

According to another aspect of the present invention, there is provided a discharge cell comprising a plurality of opposing electrodes covered with a dielectric between a pair of parallel substrates, and a partition having a surface on which a phosphor is formed. A plasma comprising a plasma display panel for filling a discharge gas and displaying an image by gas discharge, and a driving unit for driving the plasma display panel by a driving method having a setup unit, an address unit, a discharge sustaining unit and a discharge stopping unit. The display display device, wherein the driving unit divides one television field into a plurality of subfields and drives the subfield by an in-field time division gray scale display method having an address period, a discharge sustain period, and an erasing period for each subfield. A plasma display device comprising: a driving unit; Initialization period for reduction performed one or more times with at least the television field, the pulse width PWn of the last sustain pulse prior to the erase pulse for stopping the discharge of the sustain pulse for sustaining a discharge light emission
However, it is assumed that a driving method narrower than the pulse width PWn−1 of the sustain pulse other than the leading sustain pulse preceding it is used.

According to another aspect of the present invention, a discharge cell is initialized in a plasma display device that divides one television field into n sub-fields to display a luminance gradation. The initializing period is performed only once within at least one television field, and the pulse width PWn of the last sustain pulse preceding the erase pulse for stopping the discharge among the sustain pulses for maintaining the discharge light emission is different from the other. Pulse width PWn-1 of the sustain pulse
It is assumed that a narrower driving method is used.

According to another aspect of the present invention, there is provided a discharge cell comprising a plurality of opposing electrodes covered with a dielectric between a pair of parallel substrates, and a partition having a phosphor formed on the surface. A plasma comprising a plasma display panel for filling a discharge gas and displaying an image by gas discharge, and a driving unit for driving the plasma display panel by a driving method having a setup unit, an address unit, a discharge sustaining unit and a discharge stopping unit. The display device, wherein the driving unit is configured to apply a pulse voltage to a first electrode group to perform an initialization period, and to apply a pulse voltage to the first electrode group while sequentially applying a pulse voltage to the first electrode group. A pulse voltage is applied to the selected electrode to accumulate wall charges in the dielectric layer at the selected location;
A sustain period in which a pulse voltage is applied between the electrode group and the second electrode to maintain the discharge, and a discharge stop period in which the sustain discharge is stopped, wherein the pulse width of the sustain pulse in the sustain period gradually decreases. It is assumed that a driving method is used.

Further, in order to achieve the above object, the present invention provides a method of manufacturing a semiconductor device according to the present invention, wherein the pulse widths PWn-2, PWn-1, and PWn of the second and subsequent sustain pulses in the sustain period are set to be equal to those of other sustain pulses preceding the sustain pulse. It is assumed that a driving method that is narrower than the width and gradually decreases and decreases is used.

In order to achieve the above object, the present invention provides a discharge cell comprising a plurality of opposed electrodes covered with a dielectric between a pair of parallel substrates, and a partition having a phosphor formed on the surface. In a plasma display panel in which a discharge gas is sealed and an image is displayed by a gas discharge, a sustain electrode for maintaining discharge emission has a plurality of divided electrodes in one discharge cell. A plasma display device comprising a driving unit driven by a driving method having a setup unit, an address unit, a discharge sustaining unit and a discharge stopping unit,
The driving unit is configured to apply a pulse voltage to the first electrode group to perform an initialization period, and to sequentially apply a pulse voltage to the first electrode group while applying a pulse voltage to a selected electrode in the third electrode group. An address period in which a voltage is applied to accumulate wall charges in the dielectric layer at a selected location; and a sustain period in which a pulse voltage is applied between the first electrode group and the second electrode to maintain a discharge. , Consisting of a discharge stop period for stopping the sustain discharge,
The pulse width PWn of the last sustain pulse of the sustain period is
The pulse width is smaller than the pulse width PWn-1 of the other sustain pulse preceding the pulse width, and the pulse voltage applied in the initialization period is a positive pulse voltage. , PWn-1 and a driving method of applying a pulse PWe having a smaller pulse width than PWn-1.

Further, in order to achieve the above object, the present invention provides a method as described above, wherein PWn and PWn-1 are set to 2 μs ≦ PWn−
1 ≦ 10 μs, 0.5 μs ≦ (PWn-1-PWn) ≦
It is set to 8.5 μs.

Further, in order to achieve the above object, the present invention provides an ink jet printer, wherein the PWn and the PWe are 0.3 μs ≦ PWe ≦
1 μs, 0.2 μs ≦ (PWn−PWe) ≦ 7.5 μs
And

In order to achieve the above object, according to the present invention, the pulse voltage applied in the initialization period is a positive pulse voltage, and the first electrode is supplied in a discharge stop period preceding the setup section. It is assumed that a driving method of applying a positive gradient pulse waveform having a gradient at a rising portion of the voltage to the group is used.

Further, in order to achieve the above object, the present invention uses a driving method in which the rising speed of the voltage of the ramp pulse waveform during the discharge stop period is 0.5 V / μs or more and 20 V / μs or less. I do.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) Conventionally, a narrow pulse having a pulse width shorter than that of a sustain pulse is used as an erase pulse for the second electrode group, discharge is completed, wall charges are inverted, and are sufficiently accumulated. By removing the voltage applied to the discharge cell before the discharge, the wall voltage in the discharge cell is reduced to stop the discharge, and erroneous discharge due to noise or interference from priming particles from other cells is suppressed. Was.
However, when the discharge starting voltage is reduced by the electrode structure of the discharge cell such as reducing the main discharge gap or decreasing the thickness of the dielectric layer, the sustain pulse width of the driving waveform is smaller than the half width of the discharge current peak. If a sufficiently wide driving waveform is used, the discharge current per pulse increases, and the wall charge accumulated in the cell increases. The voltage at which abnormal discharge (erroneous discharge) occurs in the period from the stop period to the initialization period also decreases, thereby causing a problem that the drivable voltage range is narrowed and the drive margin is reduced.

FIG. 6 is a timing chart of driving waveforms in the plasma display device according to the first embodiment. The difference from the conventional example is that the pulse width PWn of the last sustain pulse in the sustain period is changed to the pulse width PW of the previous sustain pulse.
By making the width narrower than Wn-1, the discharge by the sustain pulse at the end of the sustain period is weakened, and the wall voltage that has increased excessively is reduced, thereby causing an abnormal discharge (self-erase) when the erase pulse voltage subsequently falls. And the erase operation is stably performed. FIG. 7 shows a timing chart of the differential voltage waveform between the first electrode and the second electrode, the voltage in the cell, and the light emission waveform. Here, the solid line indicates the differential voltage applied between the first electrode and the second electrode, and the broken line indicates the cell voltage (= wall voltage + applied voltage). Further, the wall voltage on the first electrode side is the difference between the cell internal voltage and the applied voltage.

FIG. 8 shows the dependence of the discharge start voltage Vf, the abnormal discharge occurrence voltage Vabn and the drive margin Vm on PWn in the conventional drive method and the drive method of the first embodiment. Conventionally, Vabn is as low as about 185 V, Vm is also only about 5 V, and erroneous discharge occurs in which cells are randomly turned on in a panel even in a cell in which a writing operation is not performed in an address period. This phenomenon occurs when a weak discharge occurs in the first sustain pulse of the sustain period, which triggers the discharge to be sustained in the subsequent sustain pulse.If the discharge in the first sustain pulse of the sustain period is very weak No discharge occurs even in the subsequent sustain pulse. However, since the wall voltage in the discharge cell in the non-lighting state can take any value equal to or lower than the discharge starting voltage, as time passes from the next subfield or the next subfield, interference from adjacent cells or darkness occurs. If the wall charge increases due to current etc.,
Even in a discharge cell that is not performing an address operation, a discharge occurs in the sustain period, and the cell is turned on. Normally,
In order to suppress these abnormal discharges (erroneous discharges), the wall charges are reset by a setup pulse or an erase pulse applied during the initialization period or the discharge stop period, and the wall voltage is reduced to a voltage that suppresses erroneous lighting other than address operation. Is lowering. However, when the discharge start voltage is low, the discharge current per sustain pulse increases, and the wall charges accumulated in the cell increase, so that the discharge generated when the erase pulse is applied also increases, and the discharge current during the erase discharge increases. Also increase. For this reason, originally, even in an erasing pulse in which the discharge cell is turned off by lowering the wall voltage in the discharge cell, a discharge as strong as at the time of applying the sustain pulse is generated,
As the discharge current increases, the wall charges increase, and the state becomes the same as that of the normal sustain discharge, not the erase operation. The potential difference across the discharge gas in the discharge cell increases, so that interference from other cells (crosstalk) and It is considered that the voltage at which abnormal discharge (erroneous discharge) occurs when the power supply voltage is increased to be higher than the discharge start voltage due to the influence of power supply noise becomes lower.

On the other hand, in the driving method according to the first embodiment, there is no abnormal discharge which occurs when the erase pulse voltage falls in the conventional driving method, that is, there is no self-erasing discharge, and Vabn rises to about 200 V. It can be seen that Vm is also about 20 V and has a sufficient drive margin for performing stable drive.

This is because, in the first embodiment, the last sustain pulse width of the sustain period is made narrower than the other sustain pulse widths, the wall voltage is somewhat reduced, and the discharge is completed on the second electrode side. After accumulating negative wall charges on the second electrode side and positive wall charges on the first electrode side in the cell, a narrow pulse is applied to the first electrode side as a subsequent discharge stop period. By removing the applied voltage on the way, the discharge is stopped before the positive wall charges on the first electrode side are inverted, and at the same time, the positive wall charges are left on the first electrode side and the next initialization period is started. By suppressing the increase of the discharge current peak at the time of the erase discharge, and suppressing the abnormal increase of the wall voltage before the initialization period, the abnormal discharge is suppressed and the weak discharge is sustained in the subsequent initialization period. This makes it possible to keep the wall voltage in the discharge cell constant. It is considered to have.

From the above, even if the driving method according to the first embodiment has a discharge cell structure with a low discharge starting voltage, it is possible to suppress a drop in the abnormal discharge generation voltage and realize a stable operation with a wide driving margin. It can be seen that an excellent driving method with high image quality without erroneous lighting can be realized.

In the first embodiment, the pulse width PWn of the last sustain pulse in the sustain period is defined as PWn = PW
Although n−1−1.0 μs, the present invention is not limited to this, and 0.5 μs ≦ (PWn−1−PWn) ≦ 8.5.
Needless to say, a remarkable effect is similarly obtained in the range of μs.

The PWn and PWe are 0.3
μs ≦ PWe ≦ 1 μs, 0.2 μs ≦ (PWn−PW
e) Needless to say, a remarkable effect is similarly obtained in the range of ≤7.5 μs.

(Embodiment 2) FIG. 9 is a timing chart of driving waveforms in a plasma display device according to Embodiment 2 of the present invention. The difference from the first embodiment is that the reset period for resetting the wall charges in the discharge cells is set only once in one field, the reset period is provided only at the beginning of the first subfield, and each subfield is Address period,
It is constituted by a discharge sustain period and a discharge stop period, and the pulse width of the last sustain pulse in the sustain period is set to be smaller than the pulse width PWn-1 of the previous sustain pulse. In the conventional driving method, since the initialization is performed for each subfield, the reduction of the contrast ratio due to the initialization light emission has been a problem. In order to solve this, it has been attempted to reduce the number of times of initialization and lower the luminance at the time of black display. There is a problem that the lighting state of the subfield influences, erroneous discharge occurs frequently, and the image quality is greatly reduced. In order to suppress the influence of the previous subfield, it is necessary to surely perform the erasing operation during the erasing period of each subfield, but the wall voltage due to the sustain pulse when driving the panel having a low discharge start voltage is required. Due to the increase, the discharge by the erase pulse becomes as strong as that of the normal sustain discharge, so that the normal erase operation is not performed, erroneous discharge frequently occurs, and the driving margin is narrowed.

FIG. 10 shows the correlation between the self-erasing discharge and PWn when driving the panel with various discharge start voltages Vf by the driving method according to the second embodiment. By reducing the main discharge gap and lowering Vf, a self-erasing discharge occurs at the time of the falling edge of the erasing pulse, and accompanying this, abnormal discharge such as erroneous writing and crosstalk increases. It can be seen that these abnormal discharges were reduced by using the driving method according to the second embodiment. This is because, by reducing the pulse width of the sustain pulse at the end of the sustain period, the sustain discharge at the end of the sustain period is weakened and the wall voltage is reduced. It is considered that the suppression and the normal erasing operation were realized.

From the above, it can be seen that the driving method according to the second embodiment can realize a stable erasing operation even in a PDP having a low discharge start voltage, and can realize a high-quality and high-speed driving method without erroneous discharge. I understand.

(Embodiment 3) FIG. 11 shows Embodiment 3 of the present invention.
Electrode and second electrode in the plasma display device of
4 shows a timing chart of a differential voltage waveform between electrodes, a voltage in a cell, and a light emission waveform. The difference from the first embodiment is that a drive waveform in which the pulse width of the sustain pulse in the sustain period gradually decreases as approaching the discharge stop period is used.

Table 1 shows a comparison of the presence or absence of erroneous discharge and the image quality when driving a panel with various discharge start voltages by the conventional driving method and the driving method of the third embodiment. By reducing the main discharge gap and lowering the firing voltage,
The self-erasing discharge occurs at the time of the falling edge of the erasing pulse, and the abnormal discharge such as erroneous writing and crosstalk increases in accordance with the self-erasing discharge. However, by using the driving method according to the third embodiment, It can be seen that abnormal discharge has been reduced. This is because, by gradually reducing the pulse width of the sustain pulse in the sustain period, the sustain discharge at the end of the sustain period is weakened, the wall voltage is reduced, and the self-erase discharge occurs when the voltage of the subsequent erase pulse falls. It is considered that the suppression and the normal erasing operation were realized.

[0040]

[Table 1]

From the above, it can be seen that the driving method according to the second embodiment can realize a stable erasing operation even in a PDP having a low discharge starting voltage, and can realize a high-quality and high-speed driving method without erroneous discharge. I understand.

In the third embodiment, the driving method in which the width of the third and subsequent sustain pulses from the last sustain pulse in the sustain period is gradually reduced is used. However, the present invention is not limited to this. It goes without saying that a remarkable effect can be obtained by using a driving method in which the pulse width is gradually reduced from any pulse before the last sustain pulse.

Further, in the third embodiment, the driving method in which the sustain pulse width in the sustain period is gradually reduced by an arithmetic progression is used. However, the present invention is not limited to this.
It goes without saying that a remarkable effect can also be obtained by using a driving method in which the pulse width is gradually reduced in geometric progression.

(Embodiment 4) The driving waveforms in the plasma display device of Embodiment 4 are the same as those of Embodiment 2
Is the same as The difference from the first embodiment is that an electrode structure divided into a plurality of lines in a discharge cell is used as the first electrode and the second electrode.

FIG. 12 is a schematic diagram of an electrode configuration in the plasma display device according to the fourth embodiment. In general,
In the PDP, by dividing the display electrode and reducing the electrode area, the capacitance of the panel decreases, and the sustain pulse 1
Since the discharge current around the discharge is reduced, the discharge efficiency is improved. However, since the electrodes are discontinuous, the time required for the discharge plasma generated in the main discharge gap to spread to the outer edge of the electrodes is increased, and the time from the occurrence of the address discharge in the address period to the end of the discharge is extended. As a result, the half width of the emission waveform or the discharge current peak waveform was widened. For this reason, if the address pulse is shortened during high definition, the discharge is not completed within the pulse width of the address pulse in a state where the discharge delay caused by the distribution of the discharge delay time is relatively large, and the wall charge due to the address discharge is reduced. Is not sufficiently stored, a writing failure occurs and image quality is degraded.
To improve this, a setup pulse for resetting all the discharge cells of the panel is applied at the beginning of the field during the initialization period, but an initialization period is set between each subfield to improve the contrast ratio. Since the self-erase discharge occurs at the fall of the erase pulse during the discharge stop period, the wall voltage in the discharge cell decreases, so the pulse voltage for selecting the cell in the address period of the next subfield is not provided. The discharge delay at the time of application increases, and the discharge probability within the address pulse decreases, thereby causing a writing failure.

Table 2 shows PWn, PWn-1 and the address discharge probability Fadd in the conventional driving method and the driving method of FIG.
[%] And comparison of image quality are shown. In the conventional driving method, Fadd [%] is about 86%, and the flicker is severe and the image quality is very low. However, the PDP having the electrode structure of the fourth embodiment is driven by the driving wave of FIG. As a result, Vdset is reduced by about 140 V, and Fadd [%] is improved to 99.9%, so that flicker is completely eliminated and the image quality is greatly improved.

[0047]

[Table 2]

This is because, in the fourth embodiment, the sustain pulse at the end of the sustain period is reduced, so that the sustain discharge at the end of the sustain period is weakened and the wall voltage is reduced. Because the self-erasing discharge was suppressed at the fall and the abnormal decrease of the wall voltage was suppressed, the discharge delay when applying the address pulse in the subsequent subfield was reduced, and the discharge probability within the address pulse was improved. Conceivable. Furthermore, since the self-erasing discharge of the last erasing pulse of the field is also suppressed, the abnormal drop of the wall voltage in the discharge cell is also suppressed during the subsequent initialization period of the field,
It is considered that the discharge probability of the address discharge increased despite such a discrete electrode structure because the initializing discharge spread sufficiently and the wall charge accumulated at the outermost electrode at the end of the initializing period. Can be

From these facts, the driving method in the fourth embodiment realizes a stable erasing operation even if the electrodes in the discharge cells have a discrete structure composed of a plurality of separated portions, and eliminates erroneous discharge. It is understood that a high-speed driving method with high image quality can be realized.

In the fifth embodiment, the electrode structure divided into four lines in the discharge cell is used as the first electrode and the second electrode. However, the present invention is not limited to this. Needless to say, the use of an electrode structure divided into 2 to 6 lines in the discharge cell as the first electrode and the second electrode also has a remarkable effect.

[0051]

As described above, the present invention provides a method of driving a plasma display panel in which a plurality of opposing electrodes covered with a dielectric are provided between a pair of parallel substrates, a discharge gas is enclosed, and an image is displayed by gas discharge. In the method, by using a driving method in which the pulse width PWn of the last sustain pulse of the sustain period is narrower than the pulse width PWn-1 of another sustain pulse preceding the sustain pulse, the discharge at the end of the sustain period prior to the discharge stop period is performed. By lowering the wall voltage in the cell to a value necessary and sufficient for the erasing operation during the discharge suspension period to suppress self-erasing discharge at the time of the falling edge of the erasing pulse, and performing a stable and reliable erasing operation, Stabilizes discharge during the initialization period or address period, improves image quality degradation due to poor writing, and realizes excellent PDP that can be driven at high speed for high definition That.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional plasma display panel.

FIG. 2 is an electrode matrix diagram of a conventional plasma display panel.

FIG. 3 is a block diagram of a driving circuit of an image display device using a conventional plasma display panel.

FIG. 4 is a timing chart of a conventional plasma display panel driving method.

FIG. 5 is a diagram showing a sub-field division method when expressing 256 gradations for each color in a conventional method of driving a plasma display panel.

FIG. 6 is a timing chart of driving waveforms in the plasma display device to which the first embodiment is applied.

FIG. 7 is a timing chart of a differential voltage waveform, a cell internal voltage, and a light emission waveform between a first electrode and a second electrode in the plasma display device to which the first embodiment is applied.

FIG. 8 is a diagram showing the dependence of a discharge start voltage Vf, an abnormal discharge generation voltage Vabb, and a drive margin Vm on PWn in the plasma display device to which the first embodiment is applied.

FIG. 9 is a timing chart of a differential voltage waveform between a first electrode and a second electrode, a voltage in a cell, and a light emission waveform in a plasma display device to which the second embodiment is applied.

FIG. 10 is a diagram showing a correlation between a self-erasing discharge and PWn when driving a panel with various discharge start voltages Vf in a plasma display device to which the second embodiment is applied.

FIG. 11 is a timing chart of a differential voltage waveform, a voltage in a cell, and a light emission waveform between a first electrode and a second electrode in a plasma display device to which Embodiment 3 is applied;

FIG. 12 is a diagram showing an example of an electrode configuration in a plasma display device to which the fourth embodiment is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Front substrate 12 Back substrate 13 Insulator layer 14 Data electrode group 15 Partition wall 16 Fluorescent substance 17 Dielectric glass layer 18 Protective layer 19a Electrode group 19b Electrode group 191,194 Metal electrode 192,193 Transparent electrode

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Seiki Nishimura 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 5C058 AA11 BA02 BA35 BB03 5C080 AA05 BB05 CC03 DD09 GG16 HH05 JJ02 JJ04 JJ05 JJ06 KK02 KK43

Claims (11)

[Claims] 1. A discharge cell is formed by a plurality of opposing electrodes covered with a dielectric between a pair of parallel substrates, and a partition formed by forming a phosphor on the surface is filled with a discharge gas, and an image is displayed by gas discharge. A plasma display panel, and a driving unit for driving the plasma display panel by a driving method having a setup unit, an address unit, a discharge sustaining unit and a discharge stopping unit, wherein the driving unit is , An initialization period in which a pulse voltage is applied to the first electrode group for setup, and a third period in which the pulse voltage is sequentially applied to the first electrode group.
Apply a pulse voltage to a selected electrode in the electrode group,
An address period for accumulating wall charges in the selected portion of the dielectric layer, a sustain period for applying a pulse voltage between the first electrode group and the second electrode to maintain a discharge, and stopping the sustain discharge. A plasma display device comprising a discharge suspension period, wherein the driving unit has a pulse width PWn of a last sustain pulse of the sustain period smaller than a pulse width PWn-1 of another sustain pulse preceding the sustain pulse. 2. A pulse width PWn of a last sustain pulse of the sustain period is smaller than a pulse width PWn-1 of another sustain pulse preceding the sustain pulse, and a pulse voltage applied in the initialization period is a positive pulse voltage. In addition, during the discharge stop period prior to the set-up section, PW is applied to the first electrode group.
2. The plasma display device according to claim 1, wherein a pulse PWe having a pulse width smaller than n-1 is applied. 3. A discharge cell is formed by a plurality of opposing electrodes covered with a dielectric between a pair of parallel substrates, and a partition having a phosphor formed on the surface forms a discharge cell, discharge gas is enclosed, and an image is displayed by gas discharge. A plasma display panel, and a driving unit for driving the plasma display panel by a driving method having a setup unit, an address unit, a discharge sustaining unit and a discharge stopping unit, wherein the driving unit is A driving unit that divides one television field into a plurality of subfields and drives the subfield by an in-field time division gray scale display method having an address period, a discharge sustain period, and an erasing period for each subfield. The drive unit has an initialization period for initializing the inside of the discharge cell of at least one television. The pulse width PWn of the last sustain pulse preceding the erase pulse for stopping the discharge among the sustain pulses for sustaining the discharge light emission, which is performed at least once in the befield, is a sustain pulse other than the leading sustain pulse preceding the sustain pulse. A plasma display device characterized by having a pulse width smaller than a pulse width PWn-1. 4. In a plasma display device which divides one television field into n sub-fields to display gradation of luminance, an initialization period for initializing the inside of a discharge cell is at least one television field. Is performed only once, and the pulse width PWn of the last sustain pulse preceding the erase pulse for stopping the discharge among the sustain pulses for maintaining the discharge light emission is set to the pulse width P of the other sustain pulses.
4. The plasma display device according to claim 3, wherein the width is smaller than Wn-1. 5. A discharge cell is formed by a plurality of opposed electrodes covered with a dielectric material provided between a pair of parallel substrates and a phosphor is formed on a surface of the discharge cell, a discharge gas is sealed, and an image is displayed by gas discharge. A plasma display panel comprising: a plasma display panel to be driven; and a driving unit that drives the plasma display panel by a driving method having a setup unit, an address unit, a discharge sustaining unit, and a discharge stopping unit. , An initialization period in which a pulse voltage is applied to the first electrode group for setup, and a third period in which the pulse voltage is sequentially applied to the first electrode group.
Apply a pulse voltage to a selected electrode in the electrode group,
An address period for accumulating wall charges in the selected portion of the dielectric layer, a sustain period for applying a pulse voltage between the first electrode group and the second electrode to maintain a discharge, and stopping the sustain discharge. A plasma display device comprising a discharge stop period, wherein a pulse width of a sustain pulse in the sustain period gradually decreases. 6. The pulse widths PWn-2, PWn-1, and PWn of the second and subsequent sustain pulses of the sustain period.
6. The plasma display device according to claim 5, wherein the width is gradually narrower than a pulse width of another sustain pulse preceding it. 7. A discharge cell is formed by a plurality of opposing electrodes covered with a dielectric between a pair of parallel substrates, and a partition having a phosphor formed on the surface forms a discharge cell, discharge gas is enclosed, and an image is displayed by gas discharge. In a plasma display panel, a sustain electrode for maintaining discharge emission in one discharge cell has a plurality of divided electrodes, and a setup unit, an address unit, and a discharge sustain unit are provided for the plasma display panel. And a drive unit driven by a drive method having a discharge stopping unit, wherein the drive unit applies a pulse voltage to a first electrode group, sets up an initial period, and a first electrode. While sequentially applying a pulse voltage to the group, a pulse voltage is applied to a selected electrode in the third electrode group, and wall charges are applied to the dielectric layer at the selected location. The address period to be stored and the first
A sustain period in which a pulse voltage is applied between the electrode group and the second electrode to maintain the discharge, and a discharge stop period in which the sustain discharge is stopped, the pulse width PWn of the last sustain pulse in the sustain period being: The pulse width is smaller than the pulse width PWn-1 of the other sustain pulse preceding the pulse width, and the pulse voltage applied in the initialization period is a positive pulse voltage. , PW
A plasma display device, wherein a pulse PWe having a pulse width smaller than n-1 is applied. 8. The PWn and PWn−1 are set to 2 μs
≦ PWn−1 ≦ 10 μs, 0.5 μs ≦ (PWn−1−
PWn) ≦ 8.5 μs.
The plasma display device according to the above. 9. The PWn and PWe are 0.3 μs
≦ PWe ≦ 1 μs, 0.2 μs ≦ (PWn−PWe) ≦
8. The plasma display device according to claim 1, wherein the time is 7.5 μs. 10. A pulse voltage applied in the initialization period is a positive pulse voltage, and a positive electrode having a slope in a rising portion of the voltage applied to the first electrode group in a discharge stop period preceding the setup section. 9. The plasma display device according to claim 1, wherein a gradient pulse waveform is applied. 11. The rising speed of the voltage of the ramp pulse waveform during the discharge stop period is 0.5 V / μs or more and 20 V or more.
The plasma display device according to any one of claims 1 to 9, wherein the time is not more than / μs.