JPS6239743B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for driving a self-shifting gas discharge panel, and in particular to a method for preventing undesirable loss of transferred charges, which is a problem when a wall charge transfer type shift operation is adopted. The invention relates to a new driving method.

One type of AC-driven gas discharge panel is a self-shifting gas discharge panel. In this method, a write electrode is provided at one end of a shift channel consisting of a periodic arrangement of shift discharge cells to define a write cell,
Discharge spots generated on write cells are sequentially shifted along a shift channel. There are two mechanisms for shift operation: one that utilizes the coupling of space charges between adjacent shift discharge cells, and another that utilizes the coupling of wall charges.Recently, the shift operation has been made faster and the flow of the display has improved. Many attempts have been made to adopt the latter wall charge transfer method from the viewpoint of preventing the image from appearing on the wall.

Here, the shift operation of the above-mentioned wall charge transfer method is performed by constructing a shift cell with shift electrodes arranged alternately and facing each other in the shift direction, as described in, for example, Japanese Unexamined Patent Publication No. 49-43535. is periodically connected to the four-phase busbar and sequentially applies a negative polarity shift voltage panel, and this shift panel is used to share the electrode with the cell to which it is applied, and the wall charge of the adjacent subsequent cell is assisted. This is done so that a shift discharge is generated and the positive wall charge accompanying the discharge is used for a shift discharge between the electrode and the next electrode. In such a wall charge transfer method, the amount of wall charge accompanying the first write discharge immediately affects the shift operation, and if the amount of wall charge generated is too small, it becomes impossible to generate a shift discharge during the shift operation. The wall charge representing the transferred information may disappear. This phenomenon of wall charge disappearance occurs when on-state cells are shifted successively, in such a way that the wall charge of the leading cell is incorporated into the adjacent subsequent on-cell, and the shift margin increases. This results in a sharp decline.

In order to compensate for the insufficient generation of wall charge as described above, it is possible to consider measures such as increasing the write voltage or applying write voltage pulses several times to increase the initial wall charge, but in this case, the write discharge There is a risk that the discharge itself will become too strong and cause the discharge to occur in adjacent channels or adjacent picture elements, and the write margin will be small and limited. For example, JP-A-53-
As shown in Publication No. 6533, it is possible to insert a stabilization cycle to establish a wall charge every time one cell is shifted, but there is a problem that the shift period becomes long and the benefits of high-speed shifting cannot be utilized.

In view of the above-mentioned circumstances, it is an object of the present invention to achieve a stable and reliable shift operation in a wall charge transfer type self-shift drive method. This invention also aims to prevent errors in information loss due to insufficient wall charge to be transferred, and more specifically, to ensure reliable shifting even with a sufficient amount of wall charge without reducing the write margin. The object of the present invention is to provide a new shifting method that achieves the desired operation.

Briefly stated, the present invention aims at stabilizing the wall charge by making the number of discharges in a shift cell of a specific phase within one pixel array period, for example, a shift discharge cell of the first phase adjacent to a write cell, multiple times. , the discharge spot depending on the wall charge is transferred to the next shifted discharge cell, and will be explained in more detail below with reference to the drawings.

Before explaining the driving method, an example configuration of a self-shifting gas discharge panel to which the present invention is applied will be described. Figures 1 and 2 are a sectional view of such a panel and a plan view of the main part of the electrode arrangement, and the basic panel configuration is substantially the same as that shown in, for example, Japanese Patent Application Laid-Open No. 10759/1983. It doesn't change.

That is, as is clear from FIG. 1 and FIG.
3, and an X-side electrode set represented by 14 and a Y-side electrode set represented by 15 are arranged on the inner surface of each glass substrate, and the surfaces thereof are covered with dielectric layers 16 and 17, respectively. ing.

The X-side electrode set 14 disposed on the upper glass substrate 12 has an electrode pattern as shown by solid lines in FIG. The two groups of shift electrodes x1i, x2j arranged, narrow connection conductors xl ₁ i, xl ₂ j connecting the shift electrodes of the same rank in each shift line in a direction crossing the shift line, and these connection conductors. It includes bus conductors X1 and X2 which are alternately connected on both sides. On the other hand, the Y-side electrode set 15 disposed on the lower glass substrate 13
has an electrode pattern as shown by the dotted line in FIG. 2, and is substantially in a shape in which the projection of the X-side electrode pattern is offset by a half pitch in the direction of the shift line and opposed to it. Therefore, each of the shift electrodes y ₁ i and y ₂ j on the Y side commonly faces two adjacent shift electrodes on the X side, and these shift electrodes on the Y side have the same rank. Connection conductors yl ₁ i and yl ₂ j alternately connected to the two bus conductors Y1 and Y2 on both sides are positioned between the X-side connection conductors.

Thus, in each opposing gap between the X-side shift electrodes x ₁ i, x ₂ j and the Y-side shift electrodes y ₁ i, y ₂ j, one electrode is sequentially shared between adjacent cells according to the combination of these electrodes. Four-phase shift discharge cells a ₁ , b ₁ , c ₁ , d ₁ ...
is defined, and this shift discharge cell array corresponds to each shift channel SC1 to SC4, and one period of the cell array corresponds to one picture element. Further, at the right end of each shift channel, a write electrode W is provided facing the first shift electrode _y11 , and a write discharge cell w is formed between them. A crevasse 18 (see Fig. 1) is formed on the surface of the dielectric layer in a portion corresponding to the write electrode W and the final shift electrode ye to provide a charge leakage path. Excess charge that accumulates is discharged from the end electrode.

In the panel configuration as described above, according to the driving method of the present invention, the following shift operation is performed. That is, FIG. 3 shows one of the shift operations according to the present invention.
The mode is schematically shown in relation to the shift channel configuration shown in FIG. The data is transferred while being discharged one time at a time.

Figure 4 is a diagram showing drive waveforms for achieving such a shift operation, and Figure A corresponds to the electrode voltage waveform applied to each group of shift electrodes through the four-phase bus bar and the write voltage waveform applied to the write electrode. Figure B shows the voltage waveform applied to each cell as a composite of the electrode voltages using corresponding cell codes. As is clear from the relationship between FIG. 4 and FIG. 3, the write cell W is driven at a timing corresponding to the shift cell group d of the fourth phase, and therefore one picture is drawn from cell d to cell c in the next cycle. elementary shift period
Become Tps. This one-pixel shift period Tps has four shift steps _t1 to _t4 , and three discharges occur only in the drive step _t2 of the first phase cell group a adjacent to the write cell. .

Each shift electrode is normally maintained at a sustaining voltage potential Vs, and is sequentially switched to ground potential during drive timing. Thus, the first shift electrode group Y1
When a write voltage Vw is applied to the write electrode W at step _t1 when the write cell W is at ground potential, the write cell W
The first discharge occurs. Along with this write discharge, positive charges (ions) are accumulated on the surface of the dielectric layer corresponding to the first shift electrode Y1. subsequent steps
At t ₂ , the potential of the electrode Y1 is raised to the sustaining voltage potential Vs, and the adjacent counter electrode The internal voltage is added and a discharge occurs, and at the same time the electrode Y
The wall charges on X1 are shifted and accumulated on the counter electrode X1 on the low potential side.

Here, if the one-pulse shift operation is repeated in such a way that the wall charge that has moved onto this shift electrode happens. Therefore, in this invention, the first phase cell a
After returning the wall charge that has shifted once onto the counter electrode X1 to the original electrode Y1, the maintenance voltage Vs is applied three times in the cell a so as to shift it again onto the electrode X1.
is switching the polarity of the In other words, the discharge spot shifted from the write cell W to the first phase cell a is stabilized by repeating the discharge three times there, and as a result, an increased wall charge can be established on the electrode X1. . The arrows and subscripts in FIGS. 3 and 4 indicate the direction of movement of positive wall charges due to discharge and the number of discharges in each cell or step.

The increased wall charge in cell a of the first phase is
After assisting the discharge in the second phase cell b in a step ts where the electrode Y2 is then switched to ground potential,
Move onto the electrode Y2. Next, the electrode X2 is switched to ground potential to cause a discharge in the third phase cell c, and when the first electrode group Y1 is subsequently activated again, the next picture element is written.

The main feature of the present invention is that, as described above, a stabilization cycle for increasing the wall charge to be transferred is inserted into one pixel shift period. It has been experimentally confirmed that it is most effective when inserted into the drive step of the first phase cell adjacent to the cell. Therefore, when high-speed shift operation is desired, a discharge stabilization cycle is inserted only in the first phase cell drive step, and one cycle is inserted in the other steps.
It is preferable to shift the discharge in pulses. Furthermore, from the viewpoint of improving the operating margin, the stabilization cycle requires at least three pulses. However, even if the number of panels is increased further, a significant improvement effect cannot be expected.

FIG. 5 is an operating characteristic diagram for explaining the effect of improving the operating margin according to the present invention. For the test panel, electrodes with the pattern shown in Figure 2 were arranged with an electrode pitch of 250 μm and a pixel pitch of 500 μm, and a mixed gas of Ne and 0.2% Xe was applied at a pressure of 500 Torr between opposing gaps of 100 μm. In FIG. 5, the vertical axis shows the sustain voltage Vs, and the horizontal axis corresponds to the write voltage Vw. The area indicated by the dotted line I is the operable range for one-pulse shift operation, and the enlarged area surrounded by the solid line is the area indicated by 3-1-1-1 according to the embodiment of the present invention.
In each case, the pulse width of the shift pulse was 6.5 μsec in a one-pixel shift cycle of 40 μsec, which is the operable range when performing a step shift operation. As is clear from FIG. 5, according to the present invention, the lower limit Vwmin of the write voltage is lowered and the margin of the write operation is greatly expanded.

Now, one embodiment of the present invention has been described above, but the point is that the shift step in the first phase cell adjacent to the write cell, or any one of the other second, third, and fourth phase cells. The characteristic is that the discharge is repeated multiple times, and if there is no problem with the shift speed, a stabilization cycle may be added to the shift step of the cells of other phases. In this case, 3-1-3-1 step or 3-3-1-
It is possible to take one step. Note that in this modified operation, if the number of discharges in the fourth phase cell d that is in the same phase as the write cell is three or more times, the write pulse is applied to the write cell W the same number of times in terms of time. However, such multiple pulse writing is not preferable because it lowers the upper limit Vwmax of the write operation margin and increases the risk of erroneous discharge. It is best to apply one write pulse in the write step (d cell drive step) with one pixel transfer period Tps. Therefore, if there are multiple timings at which a write pulse can be applied during the same step, the last timing It is best to apply the voltage at

On the other hand, FIG. 6 shows an example block configuration of a drive circuit when the above-mentioned 3-1-1-1 step shift operation is applied to an actual multi-line character display panel.

In FIG. 6, the panel 10 is the first display line.
ROW1 and second display row ROW2, each row has 7 write electrodes W11-W17 and W21-W.
27 are commonly connected to each other and connected to the write drive circuit 21. Furthermore, the two groups of shift electrodes on the X side are also connected to the X side shift drive circuit 22 through common bus terminals X1 and X2 for each row.
The two groups of shift electrodes on the Y side are connected to separate bus terminals Y for each row.
11, Y21 and Y12, Y22 to two Y-side shift drive circuits 23, 24, respectively.

The drive timing of each of the drive circuits described above is controlled by seven reference timing signal trains from a timing generation circuit 25 configured by combining a counter and a programmable read-only memory (PROM). That is, from this timing generation circuit 25, signals Xs ₁ and Xs ₂ corresponding to the two groups of X electrode drive waveforms, signals Ys ₁ and Ys ₂ corresponding to the Y electrode shift waveforms, and signals corresponding to the Y electrode sway shift waveforms are generated. The signals Ysw ₁ and Ysw ₂ and the write timing signal Ws are repeatedly read out in series on corresponding signal lines by a predetermined clock signal. Of these timing signals, the timing signals of the four systems on the Y side are as follows:
In the next decoder/gate circuit 26, the shift timing signals Ys ₁ and Ys ₂ are distributed to the shift drive circuits on the selected shift row side by the row selection signal Rs, and the sway shift timing signals are distributed to the shift drive circuits on the non-selected shift row side. Ysw ₁ and Ysw ₂ are now distributed. Further, the write timing signal Ws is such that a dot pattern signal of 7 bits per line read out from the character pattern generation circuit 27 based on the address data signal Ds is applied to the write drive circuit 21 at a predetermined timing synchronized with the shift operation. It's summery. Note that 28 represents an interface circuit, and 29 represents a control circuit.

The control circuit 29 supplies the timing generating circuit with a clock signal CL that defines the read timing of PROM contents, and a mode selection signal Ms that instructs switching between a shift operation and a fix display operation. When the mode selection signal Ms is at a high level, a timing pulse train is generated from the shift mode storage area of the timing generation circuit 25 corresponding to the 3-1-1-1 step shift voltage waveform as previously explained with reference to FIG. 4A. The data is read out repeatedly in one pixel shift period, and a shift operation is performed in the row selected by the row selection signal Rs. On the other hand, when the mode selection signal Ms is at a low level, a timing pulse train corresponding to the drive voltage waveform of the sway shift operation is read out from the display mode storage area of the timing generation circuit 25, and the character pattern transferred to a predetermined position is read out. A mode is provided in which a discharge spot representing a discharge spot is displayed while swaying between adjacent cells based on the position of the discharge spot.

As is clear from the above description, in short, the present invention is applicable to a shift cell of a specific phase within one pixel arrangement period, for example, a write cell, when a wall charge transfer driving method is adopted for a self-shift type gas discharge panel. This feature is characterized by inserting a stabilization cycle to increase the wall charge in the drive step of adjacent first phase discharge cells, which improves the write voltage margin and achieves stable and reliable shift operation. It has an extremely large effect on

[Brief explanation of the drawing]

1 and 2 are a cross-sectional view of essential parts and a plan view of electrode arrangement showing one example of the configuration of a self-shifting gas discharge panel to which the present invention is applied, and FIG. 3 is a diagram illustrating a shift operation according to the present invention with a shift channel. Figures 4A and 4B are diagrams showing the electrode voltage waveform and cell voltage waveform for the shift operation, and Figure 5 is a diagram showing the improvement effect of the shift operation margin in comparison. 6 are block diagrams showing one example of the configuration of the drive circuit. 10: panel, 11: gas discharge space, 12 and 13: glass substrate, 14: X side electrode set, 1
5: Y side electrode set, 16 and 17: dielectric layer, 18: crevice for charge leakage, W: writing electrode, Y11: first shift electrode, X11: second shift electrode, ad: 1st to 4th phase shift discharge cell,
Tps: 1 pixel shift period, Vs: Maintenance voltage, Vw:
Write voltage.

Claims (1)

[Scope of Claims] 1. A first and a second substrate arranged facing each other with a gas discharge space in between, a write electrode provided on the first substrate, and a write electrode provided on the second substrate opposite to the write electrode. a first shift electrode, a second shift electrode provided on the first substrate adjacent to the write electrode so as to commonly face the first shift electrode, and a second shift electrode successively and alternately facing the second shift electrode; and other shift electrodes arranged in a regular manner in sequence, and these shift electrodes define a periodic arrangement of shift discharge cells of a plurality of phases in the gas discharge space, and one shift electrode is alternately used in common. In a self-shift gas discharge panel configured to transfer wall charges accompanying discharge between adjacent cells, the shift operation within a unit array period of the shift discharge cells is performed to transfer wall charges between the write electrode and the first shift electrode. 1. A method for driving a self-shifting gas discharge panel, comprising the step of repeatedly discharging a discharge spot generated in a write cell in a shift discharge cell of a predetermined phase within the unit array period. 2. Claim 1, wherein the predetermined phase shift discharge cell is a first phase shift discharge cell between a first shift electrode and a second shift electrode.
A method for driving a self-shifting gas discharge panel as described in . 3. The shift operation has drive steps corresponding to the number of phases within one pixel array period of the shift discharge cell,
Claim 2, characterized in that the number of discharges in the drive step of the first phase shift discharge cell adjacent to the write cell is made greater than the number of discharges in the drive step of the other phase shift discharge cells. How to drive a self-shifting gas discharge panel.