JPH08320668A - Driving method for gas discharge display panel - Google Patents

Abstract

PURPOSE: To improve display quality by surely causing writing discharge in a large capacity gas discharge display panel. CONSTITUTION: When writing discharge is performed by line successive scanning in a gas discharge display panel, the panel is controlled so that applying times tpw1 , tpw2 ,... tpw N of writing discharge voltage VS, VD are made different depending on a writing discharge voltage applying time. A long writing time tpw is provided for a discharge cell or a discharge cell block having a long elapse time from a priming discharge finish time. when priming discharge of one time is caused preceding plural writing discharge periods, a long writing discharge voltage applying time is provided for a writing discharge period having a longer elapse time from a priming discharge finish time. Sufficient brightness and display quality is obtained by shortening a writing discharge time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas discharge display panel used for a display device or the like, and more specifically, an AC drive type gas discharge display which enables to obtain good display quality especially in a large capacity display device. The present invention relates to a driving method of a panel.

[0002]

2. Description of the Related Art The structure of a general gas discharge display panel will be described with reference to FIG. In the figure, a plasma display panel (PD
P) is scan electrode groups S _C1 , S _C2 , ..., S _CN and sustain electrode groups S _u1 , S arranged parallel to each other on one insulating substrate.
_u2, · · ·, and the row electrode group consisting of S _uN, on the other insulating substrate perpendicular to these group of row electrodes (crossing) to the data electrode group D ₁ has been arranged, D _2, ..., and D _M The discharge cells 11 are arranged in a matrix of N rows × M columns at the intersections of the electrodes.

In the gas discharge display panel of FIG. 6, a light emitting cell is selected by line-sequential scanning and gradation control is performed by a subfield method to display an image. In this case, at least two electrode groups orthogonal to each other are line-sequentially scanned to selectively discharge the discharge cells to emit light in the subfield. The selective discharge is obtained by selectively causing the address discharge, and the scan electrodes S _C1 , S _C2 , ...
A predetermined scanning voltage and a selective data voltage are applied to S _CN and the data electrodes D ₁ , D ₂ , ... D _M. The address discharge voltage application time is set to a sufficient length so that the address discharge is surely generated in all the selected discharge cells.

FIG. 7 (a) is a timing chart of drive voltage waveforms showing a method of driving the gas discharge display panel having the above structure. 1 subfield 12 has address discharge period 1
3 and sustain discharge period 14 and address discharge period 13
Is represented by N × t _pw depending on the number of scan electrodes (N) and the write voltage application time (t _pw ) for each scan electrode.
Therefore, when the number of subfields forming one frame is F, the total period T _w assigned to the address discharge is T _w = N × t _pw × F.

FIG. 7B is a timing chart showing the overall structure of one frame, where the number of fields F is 6, that is,
The case where the gradation display is 64 gradations (2 ⁶ ) is shown. The period T _{0 of} one frame is composed of six address discharge periods 13 and corresponding sustain discharge periods 14. Sustain discharge period 14 of each subfield 12 is the ratio of as long shown in the figure is set to 2 ^{0-2 5} controls the brightness by selecting the light emission time of the cells in one field ing. Here, when each address discharge voltage application time t _pw increases, the address period T _w also increases as in the previous equation, and the time (T ₀₎ that can be divided for the sustain discharge in the period T ₀ of one frame.
-T _W ) is oppressed.

[0006]

In the above-mentioned gas discharge display panel driving method, the write discharge voltage application time t _pw.
When the value is large, it is difficult to obtain a sufficient length for the sustain discharge period in a gas discharge display panel with a large number of scanning lines due to a large display capacity and a large number of gradations.
There is a problem that the required brightness cannot be obtained. in this case,
Not only is it not possible to obtain sufficient brightness for practical use, but it is even difficult to guarantee a normal display operation.

It is an object of the present invention to obtain a normal image discharge operation and a sufficient sustain discharge period even if the display capacity and the number of gray scales are large, so that a good image display and sufficient brightness can be easily obtained. It is to provide a driving method of a discharge display panel.

[0008]

In order to achieve the above object, a method of driving a gas discharge display panel according to the present invention is arranged such that discharge cells are arranged in a matrix at each intersection of a plurality of scan electrodes and a plurality of data electrodes. A gas for displaying a picture according to the selective writing discharge of the discharge cell, which is provided with an addressing discharge period for applying a selective data pulse to the data electrode while applying a scanning pulse line-sequentially to the scanning electrode. In the discharge display panel driving method, the application time of the address discharge voltage to which the scan pulse and the data pulse are simultaneously applied is controlled to be different depending on the application time of the address discharge voltage. .

In the gas discharge display panel driving method of the present invention, the type of the target gas discharge display panel is not particularly limited, and the gas discharge of the type in which the light emitting cells are selected by performing selective address discharge. Any type of display panel may be used. However, the driving method of the present invention is particularly preferably applied to a driving method of a gas discharge display panel of the type that causes priming discharge.

In the method for driving a gas discharge display panel according to the present invention, the application time of the address discharge voltage is (1) from the end time of the priming discharge when, for example, priming discharge is performed prior to the address discharge. Setting the application time of the address discharge voltage longer for discharge cells having a longer elapsed time until the address of the address discharge voltage is applied, (2)
The discharge cells are divided into a plurality of blocks along the scan electrodes, the application time of the address discharge voltage is selected for each block, and the block including the discharge cells having a large elapsed time from the end time of the priming discharge to the address time of the address discharge voltage Setting the application time of the writing discharge voltage longer, or (3)
In the case of adopting a driving method in which a priming discharge is generated once for each of a plurality of address discharge periods, the address discharge voltage of the address discharge period increases as the elapsed time from the end time of the priming discharge to the address discharge period increases. It is preferable to set the application time longer.

Further, in the present invention, the above (1) or (2)
It is also a preferred embodiment to combine the configuration of (3) and the configuration of (3).

[0012]

In general, a gas discharge display panel selects a light emitting (discharge) cell by line-sequential scanning and adopts gradation control by a subfield method to display a desired image. In other words, rewriting of one screen requires the number of times of writing as many as the number of subfields per discharge cell. Here, particularly in a gas discharge display panel having a large display capacity, it is important to surely generate the address discharge in a short time for good display quality. For this reason,
In the DC drive type gas discharge display panel where the discharge electrode is exposed, the pilot discharge is often used in addition to the display discharge.
An AC drive type gas discharge display panel in which at least a part of the discharge electrodes is covered with a dielectric utilizes a priming discharge that facilitates generation of a writing discharge. The priming discharge plays a role of supplying electrons, ions, or excited atoms or molecules that facilitate discharge to the discharge cell.

The occurrence of discharge includes a stochastic factor, and the time from when the address discharge voltage is applied between the discharge electrodes to when the address discharge actually occurs varies statistically. Therefore, the presence or absence of discharge occurrence when a voltage with a predetermined amplitude is applied is probabilistic, and the larger the pulse width, the more reliable the occurrence of discharge. Between the pulse width t _pw of the write discharge voltage and the discharge occurrence probability P is the ratio of discharge occurrence within a unit time after the voltage is applied, and is determined by the state of the discharge cell when the voltage is applied. , Using a constant k indicating the easiness of discharge, there is a relation expressed by the following equation P = 1-exp {-k · (t _pw −t _f )} (Equation 1) ( However, when t _pw <t _f ,
P = 0). Here, t _f is the discharge delay time determined by the structure of the discharge cell and the gas composition. In the gas discharge display panel, a good display can be obtained by making the discharge occurrence probability at the address discharge sufficiently close to 1. For that purpose, it is necessary to apply an address discharge voltage having a sufficiently large pulse width to the given t _f and k.

For example, in a gas discharge display panel having a discharge cell in which at least one of them is covered with a dielectric to generate a discharge, one frame (in order to ensure selective generation of address discharge). The priming discharge is generated at least once during a period of rewriting one screen. As time passes from the priming discharge,
The easiness k of the address discharge within a unit time becomes small.
Therefore, conventionally, the discharge occurrence probability P at the application time of the address discharge voltage in the discharge cell in which the address discharge is performed at the time when the maximum time has elapsed from the priming discharge is 1
, And each writing discharge time t _pw is set based on this.

The inventor of the present invention, as shown in FIG. 9, shows the elapsed time from the end time of the priming discharge to the application time of the address discharge voltage and the easiness k of the address discharge within a unit time.
We confirmed the relationship with. The behavior of k in FIG. 9 is
It is shown that the shorter the elapsed time from the priming discharge end time to the address discharge voltage application time, the shorter t _pw may be. Therefore, according to this relationship, the address discharge voltage application time t _pw can be shortened according to this relationship. It is controlled so as to differ depending on the application time of the writing discharge voltage. Thus, t _pw
By individually controlling the above, it is possible to obtain a sufficient discharge occurrence probability for the entire address discharge and to shorten the overall period required for the address discharge.

[0016]

EXAMPLES Hereinafter, a method of driving a gas discharge panel according to the present invention will be described in detail based on examples. FIG. 5 is a cross-sectional view of one discharge cell of an AC-driven surface discharge type gas discharge display panel manufactured to apply the method for driving a gas discharge display panel of the present invention. The gas discharge display panel is configured by arranging the illustrated discharge cells in a plane in a matrix of N rows × M columns. In manufacturing the panel, first, a pair of surface discharge electrode (row electrode) 3 composed of transparent and transparent scan electrodes 3a and sustain electrodes 3b is formed on the first glass substrate 1 over N rows, and then each After covering the surface discharge electrode pair 3 with the dielectric layer 5, the magnesium oxide layer 7 is formed to obtain a first substrate.

On the second glass substrate 2, data electrodes (column electrodes) 4 for selectively controlling discharge are formed over M columns, and after covering the data electrodes 4 with a dielectric layer 6, a phosphor is formed. 9 is applied to obtain a second substrate. Lattice-shaped partition walls 8 are formed on the dielectric layers 5 and 6, respectively. When the first substrate 1 and the second substrate are bonded together, the internal space is partitioned by the grid-shaped partition walls 8, and each partition is formed as a discharge cell (display cell) forming the discharge space 10.
The two substrates are adhered to each other at an interval of 0.1 to 0.5 mm so that the electrode pair on the surface discharge side and the data electrode are orthogonal to each other. The periphery of the glass substrate was shielded from the outside by frit glass, and the glass tube for gas introduction was removed to form an airtight structure. The discharge cell is evacuated through a gas introducing glass tube, and a discharge gas containing a rare gas as a main component is introduced and sealed, whereby a gas discharge display in which gas discharge display elements are two-dimensionally arranged in a matrix form. A panel was obtained.

Scan electrode 3 of the produced gas discharge display panel
The drive voltage pulse train (drive waveform) shown in FIG. 8 was applied to a, the sustain electrode 3b, and the data electrode 4, and the device characteristics were evaluated. This driving method follows the following basic driving procedure. First, a priming pulse VP for causing a priming discharge that more easily generates an address discharge
Is applied, and then the scan electrode 3a is line-sequentially scanned by the scan voltage pulse V _s , and the data voltage pulse Vd is applied to the data electrode 4 corresponding to the discharge cell whose light emission is selected to generate the address discharge. . After the address discharge is performed, an alternating sustain voltage V _c is applied between the sustain electrode 3b and the scan electrode 3a to sustain the discharge of the discharge cells in which the address discharge is performed, thereby maintaining the light emission.

According to the driving method of the present invention and the conventional driving method, various driving waveforms are applied to the gas discharge display panel manufactured as described above, and it is determined whether or not the address discharge is correctly generated in the discharge cell selected to emit light. It was decided to evaluate.
Here, the period of one frame is set to 16.7 ms, and 500 to 1000 main scans are performed by the non-interlaced drive system, 64
A control for displaying ~ 256 gradations was adopted.

FIGS. 1 and 4 are driving waveforms of the gas discharge display panel adopted as the first embodiment of the present invention adopted in the above evaluation and the conventional driving method, respectively. In the driving method of the first embodiment, each scan electrode S _C1 , S _C2 , ... S
The write pulse V _S having a different pulse width is applied to each _CN . A data pulse 21 having a different pulse width corresponding to each pulse width is applied to each data electrode D ₁ , ... D _M.

In order to obtain each pulse width in the first embodiment,
First, the constant k (T) and the discharge delay time t _f with respect to the elapsed time T from the end time of the priming discharge are measured and evaluated in accordance with the actual drive waveform, and P is sufficiently brought close to 1 by using Expression 1 and is good. So that you can get a nice display. Here, the address pulse width for each address discharge, that is, the scan pulse V
The overlapping width of the application time of _S and the corresponding application time of the data pulse 21 was set to increase as T increased. That is, when the scanning line number according to the scanning order is n (n = 1 to N: N is the number of scanning lines scanned by one priming discharge), the respective scanning electrodes S _C1 and S _C1
The write pulse widths t _pwi and t _pwj for generating the write discharge in _{C 2} , ..., S _CN are _set to _satisfy t _pwi ≦ t _pwj (1 ≦ i <j ≦ N).

By adopting the driving waveform as shown in FIG. 1, the elapsed time T ₁ = t _pwc x which is the condition that the conventional constant write pulse width t _pwc of FIG. 4 must be satisfied.
As compared with the case where the writing pulse width is such that the discharge occurrence probability P is sufficiently large with respect to k (T ₁ ) in N, the accurate writing operation can be performed in a shorter time. In particular,
The number of scanning lines N and the number of gradations are large, and therefore, even when all the writing operations cannot be normally performed by the conventional driving method, the driving method of the present invention can surely perform the writing operation. Met.

FIG. 2 shows drive waveforms used in the method of driving the gas discharge display panel according to the second embodiment of the present invention. In the figure, each scan electrode is _divided into a plurality of blocks, a first block S _C1, 1, ..., S _{C1, N} , a second block S _C2,1 ,.
_.. , S _{C2, N} , ..., L-th block S _{CL, 1} ,.
Divide into L scan electrode blocks such that S _{CL, N} ,
The same writing time is adopted in each scan electrode block. Final scan electrodes S _C1 final scan is performed in each _{block, N,} · · ·, S _CM, the address discharge generation time in _N, elapsed time from the priming discharge end time, i.e. the maximum elapsed time for each block T _max I asked. The constant k (T _max ) and the discharge delay time t _f with respect to the maximum elapsed time for each block are measured and evaluated, and each scan is performed so that the discharge occurrence probability P at T _max is sufficiently close to 1 by using Expression 1. The write pulse width of the block was set.

In the above example, the number of scanning electrodes included in each block is the same as each other. However, instead of this, the number of scanning electrodes included in each block is different for each block. Good. In this case, for example, the number of scan electrodes is increased in a block including discharge cells having a short address discharge time. As a result, the time required for the address discharge of each block is made approximately the same.

By adopting the drive waveform having the write pulse width as described above, as in the first embodiment,
A conventional write pulse width T _pwc is a condition that must be satisfied, and the write pulse width is such that the discharge occurrence probability P becomes sufficiently large with respect to k (T) at the elapsed time T = t _pwc × N. As compared with the above case, the accurate write operation could be performed in a shorter time. The drive method of the second embodiment has a slightly longer writing time as a whole than the drive method of the first embodiment, but has an advantage that the drive circuit can be simplified.

FIG. 3 shows a write voltage waveform in a method for driving a gas discharge display panel according to a third embodiment of the present invention.
The present embodiment is an example in which the priming discharge 15 is performed once for a plurality of address discharge periods 13. In the figure, one priming discharge 15 is applied to three subfields 12 ₁ , 12 ₂ and 12 ₃ for addressing discharges 13 ₁ , 13.
The example used for 2 and 13 ₃ is shown. In general, reducing the number of priming discharges improves the black display and improves the contrast, and thus one priming discharge may be used for a plurality of subfield address discharges. In the present embodiment, in order to deal with such a case, the pulse width of the scan pulse V _S is unified in each of the subfields 12 ₁ , 12 ₂ and 12 _{3 and} in the subfield 12 ₁ close to the priming discharge 15. short pulse width of the scan seen pulse V _S, and longer pulse width of a scan pulse V _S in the sub-field 12 ₃ away from the priming discharge. Each sub-field 12 ₁ , 12 ₂ ,
The address pulse width of 12 ₃ is set so that the discharge is surely generated at the last application time of the address discharge voltage in the subfield.

By adopting the drive waveform shown in FIG. 3, it is possible to surely generate the address discharge even for the address discharge of the subfield 12 ₃ having the longest elapsed time from the priming discharge. As a result of actually adopting the driving method of this embodiment and confirming writing, it was confirmed that an accurate writing operation can be performed in a shorter time than the conventional driving method in which a constant writing pulse width is set. . Further, the configuration of the third embodiment is adopted, and the writing pulse width is different for each scanning electrode adopted in the first embodiment when writing in each subfield, and the second embodiment. It was confirmed that the writing pulse widths that are different for each block of the scanning electrodes adopted in 1 are adopted, and that a good writing operation can be performed in a shorter time.

In each of the above embodiments, the case where the present invention is applied to the gas discharge display panel in which the sustain discharge is the surface discharge type and the address discharge is the counter discharge type has been described. However, not limited to such a case, when the driving method of the present invention is applied to a gas discharge display panel having scan electrodes and data electrodes which are orthogonal to or intersect with each other, generally the same effect can be obtained. Also, the polarity of the applied voltage, the discharge gas composition, or
It was actually confirmed that these effects were obtained regardless of the structure of the discharge cell. Further, in the above-mentioned embodiment, the case where the present invention is applied to the gas discharge display panel utilizing the priming discharge has been described, but the present invention does not necessarily require the utilization of the priming discharge.

Each of the above embodiments is merely an example, and a method of driving a gas discharge display panel which is modified or changed in various ways from the above embodiments is also included in the scope of the present invention.

[0030]

As described above, according to the driving method of the gas discharge display panel of the present invention, it is possible to surely perform the writing discharge in a short time, and the present invention provides the gas discharge display of a large display capacity. The panel has the remarkable effect of easily realizing sufficient brightness and good display characteristics.

[Brief description of drawings]

FIG. 1 is a timing chart showing a write voltage waveform in a method of driving a gas discharge display panel according to a first embodiment of the present invention.

FIG. 2 is a timing chart showing a write voltage waveform in a method of driving a gas discharge display panel according to a second embodiment of the present invention.

FIG. 3 is a timing chart showing write voltage waveforms in a method of driving a gas discharge display panel according to a third embodiment of the present invention.

FIG. 4 is a timing chart showing a write voltage waveform in a conventional gas discharge display panel driving method.

FIG. 5 is a cross-sectional view of one discharge cell of a gas discharge display panel to which a driving method according to the related art or the present invention is applied.

FIG. 6 is a schematic plan view showing a discharge cell and an electrode configuration of a gas discharge display panel.

7A and 7B are driving voltage waveforms and 1 in a driving method of a gas discharge display panel for performing gradation display, respectively.
The timing chart which shows the structure of a frame.

FIG. 8 is a timing chart showing drive voltage waveforms in a conventional method for driving a gas discharge display panel.

FIG. 9 is a graph for explaining the operation of the present invention and is a graph of experimental results showing a change in easiness k of address discharge with respect to an elapsed time T from the priming discharge end time to the address discharge occurrence time.

[Explanation of symbols]

 1 First Glass Substrate 2 Second Glass Substrate 3 Surface Discharge Electrode 4 Data Electrode 5 Dielectric Layer 6 Dielectric Layer 7 Magnesium Oxide Layer 8 Partition 9 Phosphor 10 Discharge Gas 11 Discharge Cell 12 Subfield 13 Write Discharge Period 14 Sustain discharge period

Claims (6)

[Claims] 1. Discharge cells are arranged in a matrix at respective intersections of a plurality of scan electrodes and a plurality of data electrodes, and a scan pulse is applied to the scan electrodes line-sequentially while selectively applying to the data electrodes. An address discharge period for applying a data pulse is provided,
In a method of driving a gas discharge display panel, which displays an image in accordance with selective address discharge of the discharge cells, an application time of an address discharge voltage in which the scan pulse and the data pulse are simultaneously applied to the discharge cells is A method of driving a gas discharge display panel, which is controlled so as to be different depending on an application time of an address discharge voltage. 2. A priming discharge is generated prior to the address discharge period, and the application time of the address discharge voltage is set according to the length of time elapsed from the end time of the priming discharge to the application time of the address discharge voltage. The method of driving a gas discharge display panel according to claim 1. 3. The method for driving a gas discharge display panel according to claim 2, wherein the scan electrode having a later application time of the address discharge voltage is set to have a longer application time of the address discharge voltage. 4. The discharge cell is divided into a plurality of blocks along the scan electrodes, the application time of the address discharge voltage is selected for each block, and the time from the end time of the priming discharge to the time of application of the address discharge voltage is selected. 3. The method of driving a gas discharge display panel according to claim 2, wherein the application time of the address discharge voltage is set longer for a block including a discharge cell having a longer time. 5. The address discharge voltage is increased as an elapsed time from the end time of the priming discharge to the address discharge period is longer by generating the priming discharge once prior to the address discharge periods of a plurality of times. The method for driving a gas discharge display panel according to claim 2, wherein the application time of is set to be long. 6. The method of driving a gas discharge display panel according to claim 5, wherein the scan electrode having a later application time of the address discharge voltage is set to have a longer application time of the address discharge voltage.