JPS6160438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for shifting a discharge spot in a gas discharge panel, particularly an improved discharge spot for obtaining sufficient operating margin in a self-shifting gas discharge panel of the AC discharge type. This relates to the method of shifting.

Conventionally, a gas discharge panel employing a meandering electrode structure has been proposed in Japanese Patent Application No. 51-82410 as one of the self-shift type gas discharge panels having a discharge spot shifting function. This gas discharge panel has, for example, first electrodes X ₁₁ , which are alternately connected to common conductors X1 and X2 on one substrate 1, as shown in FIGS. A group of X _{12 .} . . and a second electrode group X ₂₁ , X ₂₂ . Third electrodes y ₁₁ , y alternately connected to the common conductors Y1 and Y2
₁₂ ... and a fourth electrode group y ₂₁ , y ₂₂ .... The surface of each electrode is covered with dielectric layers 3 and 4 made of low melting point glass, etc., and a gas consisting of neon (Ne) and a small amount of xenon (Xe) is filled in the opposing gap 5 between them. .
Thus, in the gas filling gap 5, four types of discharge points ai, bi, ci, and di (i is an integer) are regularly arranged in each electrode facing area according to the combination of the electrodes. , by sequentially switching and applying pulse voltages to the four common conductors X ₁ , X ₂ and Y ₁ , Y ₂ , information on the shape of the discharge spot given to every third discharge point according to the input signal can be obtained. It becomes possible to sequentially shift to adjacent discharge points.

By the way, the shift operation of the discharge spot in a gas discharge panel as described above is such that, as is already well known, when a discharge spot exists at a certain discharge point, electrons, ions, and metastable atoms generated at that discharge point shift to neighboring discharge points. This is done by utilizing the so-called pilot effect, in which the ignition voltage at the adjacent discharge point is lower than normal. Therefore, the lower limit of the pulse voltage level for such a shift operation is determined by the ignition voltage of the adjacent discharge point reduced by the pilot effect, and the upper limit of the pulse voltage level for not exceeding a misshift. will be limited by the ignition voltage and erase condition of the discharge points on opposite sides of the shift direction and simultaneously pulsed with voltage through the common conductor. That is, referring to FIG. 1B, when shifting the discharge spot of discharge point _a2 to the adjacent discharge point _b2 , the pulse voltage applied to the discharge point _b2 is lower than the reduced ignition voltage _Vf1 of the discharge point. must also be selected to be high and at the same time lower than the ignition voltage Vf ₃ of the discharge point b ₁ to which the voltage is applied. Here, the difference in ignition voltage at these two discharge points (Vf ₃ -Vf ₁ ) is defined as a margin for the shift operation.

The object of the present invention is to provide a new shift method that can significantly improve the margin of the shift operation in the discharge spot shift operation as described above. A further object of the present invention is to provide a new shifting method for achieving stable and reliable shifting operations in a self-shifting gas discharge panel equipped with the meandering electrode structure as described above.

Briefly stated, in the present invention, when a discharge spot is shifted from one discharge point to the other discharge point between two adjacent discharge points in which one electrode is common and the opposite electrodes are separate, the opposite electrode is It is characterized in that pulse voltages which have positive polarity with respect to the common electrode and which fall first at the opposing electrode belonging to the one discharge point are applied to both in a temporally overlapping relationship. By performing such a pulse voltage application operation, the strength of the discharge at one discharge point on the side where the discharge spot is passed during the shift operation is suppressed, and the influence of unnecessary pilot flame effect on the discharge point one cycle before is suppressed. After the pulse voltage at one discharge point falls, a transverse electric field is generated between the other adjacent discharge point to actively attract the electrons generated by the discharge at one discharge point, and the discharge This promotes ignition at the discharge point on the receiving side. Embodiments of the present invention will be described in more detail below with reference to the drawings.

In the model of the discharge cell shown in FIG. 2, a discharge point A is set between the common electrode y and the counter electrode X ₁₁ and a discharge point B is set between the common electrode y and the other counter electrode X ₂₁ . According to the principle of the present invention, when shifting the polarity of these two adjacent discharge points, the opposite electrode side is positive, and the polarity shown in FIG.
Pulse voltages as shown by OP and SP are applied to each in an overlapping relationship. The overlap pulse OP applied to the discharge point A has a time width of _T0 and the voltage value of Vol, and the shift pulse SP applied to the discharge point B on the receiving side of the discharge spot is
It has a time width of Ts and a voltage value of Vs wider than _T0 . When such a pulse voltage is applied, a discharge occurs due to the overlap pulse OP at the discharge point A where information is stored in the form of wall charges, and the electrons, ions, and metastable atoms generated by the discharge are adjacent to each other. While diffusing to the discharge point B and supplying an initial current, as the overlap pulse OP falls, the electrons at the discharge point A are rapidly attracted to the discharge point B side by the positive potential of the electrode _X21 . Thus, the ignition voltage at discharge point B decreases and the shift pulse SP
A discharge occurs due to Once such a shift discharge occurs, an erase pulse may be applied to the discharge point A to erase the remaining wall charge, and a new discharge spot at the discharge point B may be maintained at that point. , the discharge point may be sequentially shifted to the next adjacent discharge point by a similar shift operation.

Now, as understood from the above explanation, the overlap pulse OP used in the shift operation of the present invention has a time width To and a peak value Vo sufficient to cause discharge at the discharge point on the side passing the discharge spot. However, on the other hand, qualitatively, a shift pulse is applied simultaneously to adjacent discharge points via a common conductor to suppress discharges that are too strong in order to reduce the influence of unnecessary pilot effects on other discharge points of the same rank. In the sense of
Also, considering the effect of increasing the pilot flame effect only on adjacent discharge points due to the transverse electric field of shift pulse SP,
The time width To is relatively narrow and the shift pulse
It will be chosen to fall before SP. However, in actual shift operation, the quantitative parameters of these two pulses are such that the shift operation margin is maximized depending on the discharge gap length of the target gas discharge panel, the composition of the filled gas, the filled pressure, etc. Such a value should be set to a value that is easily confirmed by experiment.

Figure 4 shows the dependence of the minimum shift voltage Vsmin and maximum shift voltage Vsmax on the overlap pulse experimentally for three self-shifting gas discharge panels with meandering electrode structures as shown in Figure 1. The horizontal axis shows the time width To of the overlap pulse OP (in this case, the two pulses rise at the same time, so
To is equivalent to the overlap period), and the vertical axis is the voltage value Vs of the shift pulse SP (equivalent to the voltage value Vol of the pulse OP). The discharge gap length d of the three test panels was increased in that order from 100 to 120μ, and the Xe concentration of Ne+Xe used as the filler gas was 0.2 to 0.1%.
The Pd value expressed as the product of the sealing pressure P and the discharge gap length d is also 5 to 4 Torr.
It is small between cm.

As is clear from this figure 4, the minimum shift voltage
The shift operation margin defined in the region between Vsmin and the maximum shift voltage Vsmax increases significantly depending on the time width of the overlap pulse OP.
And for the panel, overlap pulse
The maximum margin is obtained when the OP time width To is 0.3 to 1 μsec, and for the panel it is 1 to 1 μsec.
It can be seen that the maximum margin is obtained between 2 μsec, and for the panel, the maximum margin is obtained around 4 μsec. If the time width of the overlap pulse becomes too short than the discharge delay time, the discharge probability will decrease and the margin will decrease, and if it becomes too long, charged particles generated by the discharge will be attracted to the dielectric layer. A sufficient amount of space charge cannot be supplied to adjacent discharge points. In the experiment, the time width Ts of the shift pulse SP was set to 9 μsec,
Further, a narrow erasing pulse having the same voltage value as the shift pulse and a time width of 1 to 1.5 μsec was applied to the discharge point after the shift. Therefore, the overlap pulse OP
may have the same time width as the erase pulse.

Incidentally, in order to apply pulse voltages as shown in FIG. 3A to the discharge points A and B in FIG. 2 during the shift operation, a method as shown in FIG. 3B, C, or D, for example, can be used. FIG. 3B shows the most orthodox method, in which Vl is applied to the opposing electrodes X ₁₁ and X ₂₁ , respectively, with the common electrode y ₁₁ set at the reference potential Vo.
A positive potential (Vl=Vol=Vs) is applied for a predetermined period of time. In the method shown in Fig. 3C, the common electrode _{y 11 is} connected with _the counter electrode
The electrode is clamped to _V2 potential during To+Ts, and the counter electrode _X21 is clamped to _V2 potential during Ts ( _V3 - _V2 =Vol= _V3 ). Furthermore, in FIG. 3D, the common electrode y ₁₁ is clamped to the potential of V ₆ for a period of To with the counter electrode X ₁₁ set to a positive reference potential V ₄ , and then the potential of _the counter electrode It raises the potential to V ₅ (V ₅ −V ₄ =V ₄ −V ₆ =Vol
= Vs). In any of these methods, the discharge point A
A pulse voltage as shown in FIG. 3A is applied to and B.

In addition, the essence of this invention is to suppress the discharge at the discharge point on the side where the discharge spot is passed, and to enhance the pilot effect by the transverse electric field, so the falling edge of the overlap pulse OP is the shift pulse. The rise may be earlier or later than the rise of the shift pulse SP to some extent as long as it is earlier than the rise of the shift pulse SP.
It is also possible to suppress excessively strong discharge by lowering the voltage value Vol of the overlap pulse OP.

Figure 5 shows the first concept of this invention as described above.
It is a diagram showing an example of a specific drive waveform when applied to the self-shift type gas discharge panel as shown in the figure, in which Vw is the voltage applied to the write electrode W, and VY1 is the voltage applied to the first Y A voltage is applied to the electrodes y ₁₁ , y ₁₂ ... of the third electrode group through the side common conductor Y1, and VY2 is applied to the electrodes y ₂₁ , y ₂₂ ... of the fourth electrode group through the second Y-side common conductor Y2. The voltage VX1 is the voltage applied to the electrodes X ₁₁ and X ₁₂ of the first electrode group through the first X-side common conductor X1, VX
2 indicates the voltage applied to the electrodes X ₂₁ , X _{22 .} . . of the second electrode group through the second X-side common conductor X2. FIG. 5B shows a composite voltage waveform applied to each of the four types of discharge points as a composite of the voltages to these four groups of electrodes.

As is clear from the drive waveform in Figure 5, this panel is driven using a write voltage pulse WP, a shift pulse SP which also acts as an overlap pulse OP and a sustain voltage pulse, and a narrow erase pulse EP. It will be done. The discharge spot generated at the discharge point W1 between the electrodes W and _y11 by the write pulse WP is changed to the discharge point between the electrodes _y11 and the electrode _X11 by the overlap pulse OP1 and the shift pulse SP1.
After passing through two stabilization cycles using shift pulses, electrode _{X 1 is} shifted to
₁ and the discharge point b ₁ between the electrode y 21 and the electrode y ₂₁ . In this way, the discharge spots are sequentially shifted from now on, but during this time the overlap pulse
It is noted that the relative polarities of OP and shift pulse SP are alternately switched for the first and second electrodes on the X side and the third and fourth electrodes on the Y side. In other words, in this type of gas discharge panel, there are cases where the common electrode between two adjacent discharge points belongs to the first or second electrode group, and cases where the electrode belongs to the third or fourth electrode group. These two situations occur, and accordingly, the overlap pulse and the shift pulse are alternately applied to the opposing electrodes so that they have positive polarity with respect to the common electrode potential. In this way, the maximum shift operation margin can be obtained, and a reliable and stable shift operation can be performed at any point.

Figure 6 is a block diagram showing the configuration of a drive circuit for driving a self-shifting gas discharge panel with the drive waveform shown in Figure 5 above.
A shift driver SD consisting of a pair of an up transistor Q1 connected to a power supply Vs and a down transistor Q2 connected to a ground potential is connected to the four electrode group terminals X1, X2 and Y1 and Y2, respectively.
For example, nine write electrode terminals W1 to W9 corresponding to the number of shift lines are connected to transistors _Q3 and SD4 connected to the write power supply Vw.
Write drivers WD1 to WD9 consisting of _Q4 are connected. And each shift driver SD1 to SD4
are sequentially driven by the shift timing signal Sht, overlap timing signal OLT, and erase timing signal ert given from the signal synthesis circuits MX1 to MX4 based on the outputs of the basic timing signal generators TGX and TGY and the output of the gate signal generator GSG. A pulse voltage train as shown in FIG. 5 is applied to each electrode of the panel. Also write driver
Each of WD1 to WD9 is connected to a character generator CG via AND gates G1 to G9 gated by a write timing signal Wt generated by the shift gate signal of SHX2 and the frequency division counter CNT output of the clock generator CL. The output of is added selectively.

Now, as is clear from the above explanation, the discharge spot shifting method according to the present invention is extremely effective in increasing the margin of the shifting operation, and has a remarkable effect in putting self-shifting gas discharge panels into practical use. It is something.

[Brief explanation of the drawing]

1A and 1B are a plan view and a sectional view of essential parts of a self-shifting gas discharge panel to which the present invention is applied; FIG. 2 is a diagram showing a model of a discharge cell for explaining the principle of the present invention; Figure 3 is a diagram for explaining the waveform of the pulse voltage used in the shift operation and its application method. Figure 4 is a characteristic diagram showing the relationship between the margin of the shift operation and the time width of the overlap pulse. FIG. 6 is a waveform diagram of a pulse voltage used in an actual shift operation, and is a diagram showing an example of a drive circuit. X ₁₁ , X ₁₂ ... first electrode group, X ₂₁ , X ₂₂ ... second electrode group
Electrode group, y ₁₁ , y ₁₂ ... Third electrode group, y ₂₁ , y ₂₂ ...
...Fourth electrode group, W...Write electrode, OP...Overlap pulse, SP...Shift pulse, EP...
Erase pulse.

Claims (1)

[Claims] 1. First and second electrode groups arranged in a predetermined direction at approximately equal intervals on one substrate and alternately connected in common; and adjacent first and second electrode groups on the other substrate. A third and a fourth electrode group are arranged facing each other across two electrodes and are alternately connected to a common bus bar, and a discharge spot is formed between adjacent discharge points defined at each opposing portion of these electrodes. In a gas discharge panel designed to shift,
When shifting a discharge spot between adjacent discharge points that share an electrode belonging to one of the four electrode groups, two adjacent electrodes facing the common electrode are shifted to the potential of the common side electrode. A pulse voltage that has a positive polarity and falls earlier than a shift pulse of the same polarity applied to the electrode receiving the discharge spot on the side passing the discharge spot is placed in a relationship that temporally overlaps with the shift pulse. By adjusting the time width of the overlapping pulse voltages, a suppressed discharge is generated, and the space charge generated by the discharge is suppressed horizontally by the potential difference between adjacent electrodes after the fall of the overlapping pulse. The electric field attracts the discharge spot to the discharge point on the receiving side to promote ignition by the shift pulse, and furthermore, after the overlap pulse is applied, an erase pulse of a predetermined pulse width is applied to the electrode after the shift pulse is applied. A method for shifting a discharge spot, characterized in that the discharge spot is erased.