JPH07134565A - Method of driving discharge display device - Google Patents

Abstract

PURPOSE:To eliminate the instability of trickle discharge and to stably obtain trickle discharge luminescence by dividing a trickle discharge pulse for performing the trickle discharge into plural groups in accordance with pulse waveforms. CONSTITUTION:The trickle discharge pulses are divided into a first group and a second group, and the first group trickle pulse 1a is applied to electrodes C1, C2,..., Cm. The pulse width is made sufficiently longer than the time when a discharge electrode of initial trickle discharge generated by the pulse is converged and diminished. Further, a normal trickle pulse 1b is applied as the second group trickle pulse. Further, the so-called thick erase pulse whose voltage is lower but the pulse width is wider is used as an erase pulse 4. In such a manner, by expanding the pulse width of the initial trickle pulse positioned just after a scanning pulse, the discharge strength of the initial trickle pulse is strengthened, and thus, the stable trickle discharge is obtained even when the width of the trickle pulse thereafter is made the width of the normal trickle pulse.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called dot matrix type AC memory type plasma display panel for use in personal computers, office workstations, wall-mounted televisions, etc., which are expected to grow in recent years. The present invention relates to a driving method of a discharge display device used.

[0002]

2. Description of the Related Art A conventional AC type plasma display panel has a structure shown in FIG. In FIG. 5, the partial diagram (a) is a plan view and the partial diagram (b) is FIG.
It is an XX sectional view in (a). This plasma display panel 10 includes an insulating substrate 11 made of glass, an insulating substrate 12 also made of glass, a sustain electrode 13a, a scan electrode 13b, a column electrode 14, a discharge gas space 15 filled with discharge gas such as He and Xe, A partition wall 16 that secures a discharge gas space and divides pixels, a phosphor 17 that converts ultraviolet light generated by discharge of the discharge gas into visible light, and a sustain electrode 13.
a, the insulating layer 18a covering the scanning electrodes 13b and the column electrodes 14
And an insulating layer 18b for covering the insulating layer 18a and a protective layer 19 made of MgO or the like for protecting the insulating layer 18a from discharge. In addition,
In FIG. 5A, the section surrounded by the vertical and horizontal partition walls is the pixel 20. If the phosphor 17 is applied to each pixel in three colors, a color display discharge display device can be obtained.

Next, FIG. 6 shows a diagram focusing only on the electrodes of the plasma display panel. In FIG. 6, reference numeral 21 denotes a seal portion for bonding the insulating substrate 11 and the insulating substrate 12 to each other, enclosing the discharge gas therein and hermetically sealing it, C ₁ ,
C _2, ..., C _m is the sustain electrode _{13a, S 1, S 2,} ..., S
_m scanning electrodes _{13b, D 1, D 2 ...} , the D _n-1, D _n is a column electrode. In the plasma display panel having the configuration shown in FIGS. 5 and 6, when the scan pulse and the data pulse are applied between the scan electrode 13b and the column electrode 14 with the same timing to perform the write discharge, the adjacent discharge is maintained thereafter. The sustain discharge is sustained by an alternating sustain discharge pulse (hereinafter referred to as sustain pulse) applied between the electrode 13a and the scan electrode 13b. Such a function is called a memory function. Further, the sustain discharge can be stopped by applying a pulse having a narrow pulse width called an erase pulse, a low voltage pulse, or a pulse with a gradual rise of the pulse to the scan electrode 13b or the sustain electrode 13a.

FIG. 7 shows a driving waveform of the plasma display panel based on the above principle. 7, a waveform (A) is a voltage waveform applied to the sustain electrodes C ₁ , C ₂ , ..., C _m , a waveform (B) is a voltage waveform applied to the scan electrode S ₁ , and a waveform (C) is Voltage waveform applied to scan electrode S ₂ ,
A waveform (D) shows a voltage waveform applied to the scan electrodes S _m , and a waveform (E) shows a voltage waveform applied to the column electrodes D _j (j = 1 to n).

A sustain pulse 31 and an erase pulse 34 are applied to the sustain electrodes C ₁ , C ₂ , ..., C _m . In addition to the sustain pulse 32 common to these electrodes, scan pulses 33 are line-sequentially applied to the scan electrodes S ₁ , S ₂ , ..., S _m at independent timings. When it is desired to cause the pixel a _ij at the intersection of the i-th scan electrode S _i (i = 1 to m) and the j-th column electrode D _j to emit light, the data pulse 35 is set to i.
It is applied in synchronization with the scan pulse 33 applied to the th scan electrode. A method for driving the plasma display panel by separating the time for writing and the time for sustaining discharge as shown in FIG. 7 is disclosed in, for example, Japanese Patent Laid-Open No. 63-151.
Japanese Patent Application No. 997 (Japanese Patent Application No. 61-300576) and Japanese Patent Application Laid-Open No. 4-195188 (Japanese Patent Application No. 2-331589).
Japanese patent publication).

Next, a case of performing gradation display using such a plasma display panel will be described. In FIG. 8, the horizontal axis represents time and the vertical axis represents each scan electrode. Also, the diagonal line marked as the write timing WR is
The timing of writing discharge in each scan electrode is
The time LD indicated by m horizontal lines corresponding to each scan electrode indicates the sustain emission time, and the vertical thick line indicated as the erase timing ER indicates the timing of the erase discharge. The brightness gradation is expressed by the number of times of light emission. As shown in FIG. 8, one field is divided into a plurality of subfields (six subfields SF1 to SF6 in the case of FIG. 8), the number of times of light emission in each subfield is weighted by 2 ⁿ , and luminance gradation is obtained. Is expressed as follows.

[0007]

A _n is a variable that takes a value of 1 or 0.
FIG. 8 shows the case of k = 6, and 2 ⁶ = 64 gradations can be expressed.

[0009]

However, the conventional drive waveform shown in FIG. 7 has a problem that the sustain discharge becomes unstable and normal display cannot be performed. An object of the present invention is to eliminate the instability of sustain discharge and realize a method of driving a discharge display device using a plasma display panel, which can stably emit sustain discharge. Another object of the present invention is to use the above-described method of driving a discharge display device using a plasma display panel to stably obtain sustain discharge light emission, so that sustain discharge light emission with higher efficiency can be obtained. is there.

[0010]

According to the present invention, there is provided a method of driving a discharge display device using an AC memory type plasma display panel, wherein a period for performing scanning and writing collectively to the plasma display panel. And a driving method of a discharge display device in which a period during which only a sustain discharge is performed after that is driven, a sustain discharge pulse for performing the sustain discharge is divided into a plurality of groups by a pulse waveform, and the scan writing is performed. At least one of the pulse width value and the pulse voltage value of the sustain discharge pulse belonging to the first group, which includes at least the sustain discharge pulse to be applied first, is compared with the respective values of the sustain discharge pulses belonging to the other groups. A driving method of a discharge display device is obtained which is characterized in that it has a large size.

A method of driving a discharge display device according to claim 1, wherein an AC memory type plasma display panel is used to perform scanning and writing in a lump and then only sustain discharge in a lump. , The pulse width of the sustain discharge pulse belonging to the first group is made longer than the time for which the discharge current generated by the application of one sustain discharge pulse converges and disappears, and the sustain discharge pulse having the minimum pulse width in the second and subsequent groups. According to another aspect of the present invention, there is provided a driving method of a discharge display device, characterized in that the sustain discharge pulse width of the group consisting of is shorter than the time for which the discharge current generated by the application of one sustain discharge pulse converges and disappears.

[0012]

The present invention has solved the problems in the conventional driving method of the discharge display device by adopting the above-mentioned structure. That is, upon carefully observing the instability of the sustain discharge, it was found that the unstable sustain discharge is often observed in the cells in which the time from the write discharge to the sustain discharge due to the scan pulse and the data pulse is long. This will be described with reference to FIG. In FIG. 9, the waveform (A) is the sustain electrode C.
Voltage waveform applied to ₁ , C ₂ , ..., C _m , waveform (B)
Is a voltage waveform applied to the scan electrode S ₁ , and the waveform (E) is
The voltage waveform applied to the column electrode D _j (j = 1 to n), waveform (F), shows the discharge light emission waveform of the pixel a _{1j at} the intersection of the first scan electrode and the jth column electrode D _j .

In FIG. 9, when the sustain discharge is normally performed, discharge light emission grows as shown by the broken line in the light emission waveform (F) in FIG. However, in some cases, since the initial discharge of the sustain discharge is weak, it was found that the sustain discharge does not grow and disappears as shown by the solid line in the waveform (F). This instability phenomenon of the sustain discharge was particularly remarkable in the cell in which the time from the writing discharge by the scan pulse and the data pulse to the sustain discharge is long. Therefore, considering the strength of the initial sustain discharge to be sufficiently strong, widening the pulse width of the initial sustain discharge or increasing the voltage of the sustain pulse strengthens these weak sustain discharges. It became possible to remove the qualitative.

Further, according to the present invention, the sustain pulse widths of the sustain pulse groups after the second group are set to the conventional pulse width (2 to 3).
It has become possible to make it even shorter than (μsec).
That is, conventionally, when the sustain pulse width is narrowed, the instability of the sustain discharge is further increased, so that the sustain pulse having a short pulse width cannot be used. However, by using the driving method of the present invention, stable sustain discharge can be obtained even when a sustain pulse having a short width is used.

When a sustain pulse having a shorter width than the conventional one, particularly a sustain pulse having a pulse width shorter than the time for which the discharge current generated by applying one sustain pulse converges and disappears, is used, it is disclosed in Japanese Patent Laid-Open No. 3-78789. As disclosed in Japanese Patent Application No. 1-216497), the luminous efficiency of sustain discharge can be increased. When driving a panel with a large area and a large amount of heat generated by sustain discharge emission, it is possible to suppress the heat generation of the panel and reduce the power consumption of the device by using a pulse of a short width with high sustain discharge emission efficiency. It was

Further, as described above, by using the present invention, the pulse width of the sustain pulse group after the second group can be shortened. As a result, the sustain pulse cycle of this portion can be shortened. Therefore, the sustain emission period LD in FIG. 8 can be shortened. As a result, it is possible to expand the width of the scan pulse and the data pulse to generate the reliable writing discharge by allocating the extra time to the time required for the writing discharge. Alternatively, by using the extra time, the number of subfields is further increased, and higher gradation display can be realized.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described with reference to the drawings. As the plasma display panel for carrying out the present invention, the one shown in FIGS. 5 and 6 was used.
The sustain electrodes C ₁ , C ₂ , ..., C _m , and the scan electrodes S ₁ ,
S ₂ , ..., S _m are each 240, and the column electrodes D ₁ ,
The number of D ₂ , ..., D _n−1 , D _n is 960. The number of sub-fields was set to 8 and display with 2 ⁸ = 256 gradations was performed.

FIG. 1 shows drive waveforms according to the first embodiment of the present invention. In FIG. 1, the waveform (A) shows the sustain electrodes C ₁ and C.
₂ , ..., C _m , the waveform (B) is the voltage waveform applied to the first scan electrode S ₁ , and the waveform (C) is the voltage waveform applied to the next scan electrode S ₂ , D) is the voltage waveform applied to the last scan electrode S _m , and waveform (E) is
7 is a voltage waveform applied to the column electrodes D _j (j = 1 to 960).

In this embodiment, the sustain pulse is divided into the first group and the second group.
It was divided into two groups. The sustain pulse 1a of the first group (pulse width 20 μsec, voltage −160 V) was applied to the sustain electrodes C ₁ , C ₂ , ..., C _m . This pulse width was set to be sufficiently longer than the time that the discharge current of the first sustain discharge generated by this pulse converges and disappears. Further, as the sustain pulse of the second group, sustain pulse 1b having a normal sustain pulse width (pulse width 3 μsec, cycle 10 μsec, voltage is the same as sustain pulse 1a of the first group) was applied. As the erase pulse 4, a so-called wide erase pulse having a wide pulse width (20 μsec) but a low voltage (-100 V) was used. Of course, instead of such an erase pulse, an erase pulse having a narrow width, an erase pulse having a blunted waveform, or a composite pulse of these may be used.

The scan electrodes S ₁ , S ₂ , ..., S _m have a second group of sustain pulses 2b common to these scan electrodes (the pulse width, period, and voltage are the same as those of the second group sustain pulse 1b). ), Scan pulse 3 (pulse width 5 μsec, voltage −180 V) was applied to each scan electrode at an independent timing.

When light emission data is present in each column electrode D _j , a data pulse 5 (having the same pulse width as the scan pulse 3,
The voltage of 80 V) was applied in synchronization with the scan pulse 3.

As described above, the discharge intensity of the first sustain pulse can be increased by widening the pulse width of the first sustain pulse located immediately after the scan pulse, and as a result, the width of the subsequent sustain pulse is usually increased. Even with the sustain pulse width of, a stable sustain discharge can be obtained.

Further, the sustain pulse of the second group has a width of 1 μsec,
Even if the cycle was further shortened to 5 μs, stable sustain discharge was obtained. When the width is 1 μsec, the pulse voltage is removed before the discharge current converges and disappears. Therefore, by setting the pulse width to 1 μsec, the luminous efficiency by the sustain pulse can be increased by 1.5 times, and the sustain pulse current required for light emission can be reduced to 1 / 1.5 while obtaining the same brightness. did it. As a result, the heat generation of the panel can be reduced, and the power consumption of the entire display device can be reduced by about 20%. Also, the cycle is 5
The sustain emission period LD (see FIG. 8) was able to be shortened to μ seconds.
Was reduced to half, and this time was further devoted to the increase of the pulse width of the scan pulse and the data pulse, and these pulse widths could be extended to 6 μsec.

Next, FIG. 2 shows drive waveforms in the second embodiment of the present invention. In FIG. 2, waveforms (A) to (E) are waveforms applied to the same electrodes as in FIG. 1, respectively. In this embodiment, the sustain pulse is divided into three groups from the first group to the third group.

As shown in the waveform (A), the sustain electrodes C ₁ , C ₂ , ..., C _m have a sustain pulse 1c of the first group (pulse width 20 μsec, voltage −160 V) and a normal sustain pulse. A sustain pulse 1e of the third group having a width (pulse width 3 μsec, period 10 μsec, voltage is the same as the sustain pulse 1c of the first group),
Thick erase pulse 4 (pulse width 20 μs, voltage -100
V) and were applied.

The scan electrodes S ₁ , S ₂ , ..., S _m have the same sustain pulse 2 d of the second group (pulse width 5 μsec, voltage equal to the sustain pulse 1 c of the first group) in common to these scan electrodes. ),
The sustain pulse 2e of the third group (pulse width, period, voltage is the third
The same as the sustain pulse 1e of the group) and the scan pulse 3 (pulse width 5 μsec, voltage-1
80 V) was applied.

If light emission data is present in each column electrode D _j , a data pulse 5 (having the same pulse width as the scan pulse 3,
The voltage of 80 V) was applied in synchronization with the scan pulse 3.

As described above, by widening the pulse width of the sustain pulse positioned immediately after the scan pulse and also widening the second sustain pulse width, the discharge intensity of the initial sustain pulse after the scan discharge can be strengthened. As a result, as compared with the first embodiment, stable sustain discharge can be obtained even if the width of the sustain pulse thereafter is reduced to the normal sustain pulse width or less.

Next, FIG. 3 shows the drive waveforms in the third embodiment of the present invention. In FIG. 3, waveforms (A) to (E) are waveforms applied to the same electrodes as in FIG. 1, respectively. In this embodiment, the sustain pulse is divided into three groups from the first group to the third group.

As shown in the waveform (A), the sustain electrodes ₁ f (pulse width 20 μsec, voltage −160 V) of the first group and the second group of sustain electrodes C ₁ , C ₂ , ..., C _m are provided. Sustain pulse 1g (pulse width 5 μsec, voltage is 1f sustain pulse 1f)
Same as the above), and sustain pulse 1h of the third group having a normal pulse width.
(Pulse width 3 μsec, cycle 10 μsec, voltage is the same as sustain pulse 1f of the first group) and erase pulse 4 (pulse width 20 μsec.
Seconds, and a wide erase pulse having a voltage of −100 V) was applied.

The scan electrodes S ₁ , S ₂ , ..., S _m have the first group of sustain pulses 2f (the pulse width and voltage are the same as those of the first group of sustain pulses 1f) common to these scan electrodes. Sustain pulse 2g of the second group (pulse width, voltage is the same as sustain pulse 1g of the second group), sustain pulse 2h of the third group (pulse width, period, voltage is the same as sustain pulse 1h of the third group), Scan pulse 3 (pulse width 5 μsec, voltage −180 V) was applied to each scan electrode at an independent timing.

If light emission data is present in each column electrode D _j , a data pulse 5 (having the same pulse width as the scan pulse 3,
The voltage of 80 V) was applied in synchronization with the scan pulse 3.

As described above, by widening the sustain pulse widths of the first to fourth pulses positioned immediately after the scan pulse, the discharge intensity of the initial sustain pulse after the scan discharge can be strengthened. As a result, It became possible to obtain a particularly stable sustain discharge even when the width of the sustain pulse after that was set to be equal to or less than the normal pulse width as compared with the second embodiment.

Next, FIG. 4 shows the drive waveforms in the fourth embodiment of the present invention. In FIG. 4, waveforms (A) to (E) are waveforms applied to the same electrodes as in FIG. 1, respectively.

The sustain electrodes C _1, C _2, ..., the C _m, the first
Group sustain pulse 1i (pulse width 3 μs, voltage −180
V), sustain pulse 1j of the second group (the pulse width is the same as sustain pulse 1i of the first group, cycle 10 μs, voltage −160 V)
And erase pulse 4 (pulse width 20 μs, voltage −100 V
Thick erase pulse) was applied.

The scan electrodes S ₁ , S ₂ , ..., S _m have a second group of sustain pulses 2j common to these electrodes.
In addition to the same pulse width, period, and voltage as the sustain pulse 1j of the second group, scan pulse 3 (pulse width 5 μsec, voltage −180 V) was applied to each scan electrode at an independent timing.

When light emission data is present, a data pulse 5 (pulse width is the same as scan pulse 3, voltage 80 V) is applied to each column electrode D _j in synchronization with scan pulse 3.

As described above, by increasing the sustain pulse voltage located immediately after the scan pulse within the range where the false discharge does not occur due to this pulse, the discharge intensity of the sustain pulse immediately after the scan discharge can be strengthened. As a result, The stable sustain discharge can be obtained even if the width of the sustain pulse thereafter is set to the normal pulse width.

In the fourth embodiment, the pulse voltage is increased only for the first sustain pulse, but as in the second and third embodiments, the voltage may be increased for a plurality of pulses at the initial stage of sustain discharge. Not to mention good things.

In the above embodiment, the sustain pulse width or the sustain pulse voltage is independently changed to increase the discharge intensity at the initial stage of the sustain discharge, but these two means may be used in combination.

Further, in the second to fourth embodiments, the case where the sustain pulse width of the last sustain pulse group is the normal sustain pulse width has been described. However, not limited to this, as in the first embodiment, the sustain pulse width of the last sustain pulse group may be shortened to increase the luminous efficiency of the sustain pulse and to widen the pulse width of the scan pulse or the data pulse. Not to mention good things.

In the above embodiments, the case where the discharge display device using the surface discharge AC memory type plasma display panel shown in FIGS. 5 and 6 is driven has been described, but the present invention is not limited to this. Needless to say, it can be applied to any type of AC memory type plasma display panel.

[0043]

As described above, according to the driving method of the present invention, when scanning writing is performed collectively and then only sustaining discharge is performed collectively, the luminous efficiency of the sustaining discharge is increased and the writing discharge is performed. It is possible to reliably perform the transition to the sustain discharge and display the correct display.

Further, by narrowing the sustain pulse width of the second and subsequent groups, the sustain discharge luminous efficiency can be increased and the power consumption can be reduced, and the time required for the sustain discharge can be shortened. The present invention is industrially very useful because it can be assigned to writing discharge to further increase the writing probability, or the number of subfields can be increased to support high gradation display.

[Brief description of drawings]

FIG. 1 is a diagram showing drive waveforms in a first embodiment of the present invention.

FIG. 2 is a diagram showing drive waveforms in a second embodiment of the present invention.

FIG. 3 is a diagram showing drive waveforms in a third embodiment of the present invention.

FIG. 4 is a diagram showing drive waveforms in a fourth embodiment of the present invention.

FIG. 5 is a plan view and a sectional view of a plasma display panel.

FIG. 6 is a configuration diagram of a plasma display panel focusing on the electrode arrangement.

FIG. 7 is a time chart showing driving waveforms in a conventional plasma display panel.

FIG. 8 is a time chart diagram showing a gradation display method in the plasma display panel.

FIG. 9 is a diagram illustrating the operation of the driving method of the present invention.

[Explanation of symbols]

1a, 1c, 1f, 1i, 2f 1st group sustain pulse 1b, 1g, 1j, 2b, 2d, 2g, 2j 2nd group sustain pulse 1e, 1h, 2e, 2h Third group sustain pulse 3, 33 Scan pulse 4,34 Erase pulse 5,35 Data pulse 10 Plasma display panel 11,12 Insulating substrate 13a Sustaining electrode 13b Scan electrode 14 Column electrode 15 Discharge gas space 16 Partition wall 17 Phosphor 18a, 18b Insulating layer 19 Protective layer 20 Pixel 21 sealing portions 31 and 32 sustain pulses SF1, ..., SF6 subfield D _1, ..., D _n column electrodes C _1, ..., C _m sustain electrodes S _1, ..., S _m scanning electrodes

Claims (2)

[Claims] 1. A method of driving a discharge display device using an AC memory type plasma display panel, wherein a period during which scan writing is collectively performed on the plasma display panel and a period during which only sustain discharge is performed thereafter. In the driving method of the discharge display device for separately driving and, the sustain discharge pulse for performing the sustain discharge is divided into a plurality of groups by a pulse waveform, the sustain discharge pulse applied first after the scan writing First including at least
Discharge display characterized in that at least one of a pulse width value and a pulse voltage value of a sustain discharge pulse belonging to a group is set to be larger than respective values of sustain discharge pulses belonging to another group. Device driving method. 2. The method for driving a discharge display device according to claim 1, wherein the pulse width of the sustain discharge pulse belonging to the first group is defined as a time when a discharge current generated by applying one sustain discharge pulse converges and disappears. In addition to increasing the length, the sustain discharge pulse width of the sustain discharge pulse group having the minimum pulse width after the second group is set shorter than the time for which the discharge current generated by the application of one sustain discharge pulse converges and disappears. A driving method of a discharge display device characterized.