JPH01303494A - Driving method for gas discharge display panel - Google Patents

Abstract

PURPOSE:To reduce the sputter and minus glow light emission of an anode by connecting one kind of electrodes of respective discharge cells to electrode leads through resistances and capacitors which are parallel to one another, applying voltage pulses to the electrode leads, and maintaining pulse discharge for light emission display. CONSTITUTION:A cathode lead 2, a resistance 3, a conductor 40, and a cathode 4 covering them are formed on an insulation substrate 1, the cathode 4 is connected to the cathode lead 2 through the resistance 3 and further to a cathode driving circuit 13, and the anode 10 is connected to the anode lead 12 and further to an anode driving circuit 16. Further, the arrangement of the cathode 4 and cathode lead 2 and the thickness and material of an insulation layer 42 are adjusted to adjust the capacity between the cathode 4 and cathode lead 2. A capacitor Cb is added to a resistance interposed between an electrode and a driving circuit in parallel to secure fast-rising discharge. In a discharge cell where anode-cathode discharge is caused, display discharge is maintained between the anode and cathode with maintaining pulses applied to the cathode because of the ignition effect of residual charges. Consequently, the sputtering of the anode and the generation of minus glow light nearby the anode can be suppressed.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a gas discharge display panel for displaying 9 character images, which is constructed of a discharge display element that utilizes visible light or ultraviolet light generated by gas discharge. This relates to a driving method.

[Conventional technology]

The gas discharge display panel is driven by turning each discharge cell on and off.
A combination of an address discharge to select off and a sustain discharge to cause the selected cell to emit light with high brightness is performed. Among these, regarding sustaining discharge, the rise is fast;
For example, it is discussed in JP-A-58-021-293 that the luminous efficiency is improved by using a voltage pulse with a short pulse width and utilizing only the light emitted immediately after the start of discharge.

[Problem to be solved by the invention]

The aforementioned pulses are usually applied to the electrodes without passing through a resistor to prevent "rounding" of the waveform. At this time, the electrode to which the pulse is applied or the vicinity thereof undergoes sputtering as will be explained later. As a result, the electrode itself deteriorates and the discharge characteristics deteriorate. Furthermore, since a sputtered film is formed near the electrode, visible light transmittance decreases when the electrode is provided on a light-transmitting face plate. Furthermore, luminescence of the enclosed gas may be observed near the electrodes. This light emission causes deterioration of display image quality.

[Means to solve the problem]

The above problems can be solved by taking measures to reduce spatter caused by discharge.

In the present invention, an impedance is inserted between the anode and the drive circuit to limit the flow of current into the anode. Further, if necessary, a positive bias voltage is superimposed on the voltage pulse of the anode, and together with the effect of inserting a resistor, electrode sputtering can be suppressed more effectively. Furthermore, by adding a capacitor Cb in parallel to the resistor R inserted between the electrode and the drive circuit, a fast rising discharge is ensured.

[Effect]

The reason why sputtering occurs at or near the electrode when a discharge is caused using a pulse voltage is as follows.

In a gas discharge display panel, there are many electrodes in the vicinity of one discharge cell, so a capacitance is formed between the inner wall of the discharge cell and these electrodes. Now, if we consider the case where a positive pulse is applied to the anode, part of the discharge current flows into this stray capacitance, charging up the inner wall of the discharge cell with positive ions. As a result, the wall potential gradually increases, and when the difference between the applied voltage and the wall voltage becomes equal to or less than the discharge sustaining voltage, the discharge stops. Next, when the applied pulse voltage is removed, the potential of the anode becomes lower than that of the wall, and a discharge of opposite polarity to the above-mentioned discharge occurs. At this time, the positive ions collide with the anode, causing sputtering on the anode and generating negative glow light near the anode. Further, when the applied pulse is removed, discharge occurs even between the inner wall where positive ions are not accumulated or between the cathode and the inner wall.

In the above example, if an impedance is inserted between the anode and the drive circuit, the flow of current into the anode can be restricted. Therefore, electrode sputtering can be suppressed. Also, as you can see from the above explanation, the problem is the potential difference between the anode voltage and the wall potential after the voltage pulse is applied, so if a positive bias voltage is superimposed on the anode voltage pulse, the effect of inserting the resistor can be reduced. In addition, electrode spatter can be suppressed more effectively.

By the way, in a gas discharge display panel, each electrode forms a capacitance C3 between each electrode and other electrodes. Therefore, when a resistor R is inserted between the electrode and its drive circuit, the applied voltage is transmitted to the electrode in a rounded form with a time constant RCs. For example, C5=2pF.

If R=500 and Ω, the time constant RCs::1 μs. This makes it impossible to generate a discharge that rises quickly.

This problem can be solved by adding a capacitor Cb in parallel to the resistor R inserted between the electrode and the drive circuit.

This will be explained using FIG. 11. In FIG. 11, point A corresponds to the output terminal or cathode lead of the drive circuit. R is resistance and Cb is capacitance. Point B corresponds to the electrode in question. As shown, electrode B has a stray capacitance C8.

A voltage waveform indicated by the solid line in FIG. 12 is applied to point A. That is, when the voltage is instantaneously changed from 0 to EO at time = 0, the voltage at point B shows a time change as shown by the dotted line a in FIG. This can be expressed numerically as follows. That is, 1 point B
After reaching Ez=YEo at t=Q, the voltage approaches Eo with a time constant (Cs+Cb)XR. In reality, a discharge current flows from electrode B to point C, so the value R2 approaches the value obtained by subtracting the voltage drop due to resistor R. This is shown in FIG. 12 with a dashed dotted line. Therefore, if E1=γEo is a value sufficient to start the discharge, the discharge will rise sufficiently quickly. For this, Cb must be approximately 0.8 of C8, for example.
It would be better if it were more than double.

Next, consider the case where the applied pulse voltage returns to O.

At this time, the equivalent circuit of the discharge cell is shown in Figure 13 or Figure 1.
It will look like Figure 4. In FIG. 13, 60 is a discharge cell;
61 is a portion of the wall surface of the discharge cell where charges are accumulated, and 63 is a stray capacitance formed between the portion 61 and the external core.

If the value of this stray capacitance is Ct and the current flowing through the electrode 10 is i, then the voltage between the electrode 1o and the charge storage section 61 is v
The theory is P Ct P Cb R+ 1 . Here, Vo is the initial value of Ct charge pressure, p
is the Heaviside operator. Conventionally, R=O, so equation (3) is V-=Vo i / P Ct ・
...(4), but it can be seen that by inserting R1 and Cb, V becomes smaller by the component of the third term on the right side of equation (3).

For example, Ct=2 p F, Cb=0.5 p F, R
: LookΩ, assuming the discharge decay time constant to be 0.1 μm,
Equations (3) and (4) are respectively V+a=Vo 2 X 1012f 1 d t
・=(3')Vm=Vo O, 5X 10"f
i d t −(4'), and the (3'th
), it can be seen that when the pulse is applied through an impedance, the inter-electrode voltage attenuates about four times faster, and therefore the discharge period is shorter.

The current flowing out from the charge-accumulating portion 61 of the discharge cell wall does not necessarily all flow to the electrode 10. It can also flow to another wall with a sufficient potential difference or to another electrode. FIG. 14 shows an equivalent circuit of a discharge cell having another electrode 62, for example, the electrode 62 is grounded.

Assuming that the voltage between the electrodes 10 and 61 is V B , the voltage between the electrodes 62 and 61 is 2,', the current flowing into the electrode 10 is i, and the current flowing into the electrode 62 is i', Vm=Vo
)/PCt-iZ...(5)=v,'-
i z , −(6) Therefore.

1=(V,'V,)/Z-(7)
becomes. Here, Z is an impedance formed by the resistor 3 and the capacitor 50. Usually, the difference between ■,′ and ■ is v,
' and Vyo, the current flowing into the electrode 10 becomes significantly smaller when the electrode 62 is present. in this case,
As in the conventional case, impedance 2 is 0, and v, <
v,'.

The current flowing into the electrode 10 remains the same whether or not the electrode 62 is present. Also from this point of view, it is important to provide the resistor 3.

The above describes the means for preventing the electrode gas from being sputtered when a positive pulse is applied to the electrode 10, but the means for preventing the vicinity of the electrode from being spattered when a negative pulse is applied to the electrode is also exactly the same. .

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3. FIG. 2 is a cross-sectional view of a discharge cell in a gas discharge display panel according to the present invention, FIG. 3 is a diagram showing the electrode wiring in the panel and the connection of the drive circuit, and FIG. 1 is a diagram showing the output waveform of each drive circuit. It is a diagram.

The groove structure of the panel will be explained using FIG. A spacer 8 for forming a discharge space is sandwiched between an insulating substrate 1 made of soda glass or ceramic, and a translucent UfI plate 11 made of soda glass or the like. For the spacer 8, a laminated layer of chemically etched thin glass or etched photosensitive glass may be used. Place the insulating plate on top of the cathode lead 2. Resistance 3. The conductor 40 and the cathode 4 covering it are formed by a thick film printing method or the like. For example, the resistance is 1. OOkΩ~2M. Resistance 3. An insulating layer 4 is formed between the cathode lead 2 and the cathode 4 using a thick film printing method or the like.
2 is formed. By adjusting the three-dimensional arrangement of the cathode 4 and the cathode lead 2, the thickness and material of the insulating layer 42, the amount '6 between the cathode 4 and the cathode lead 2 is adjusted.

An anode 10 is formed on the transparent face plate 11 by a thick film printing method or the like. The auxiliary discharge space 6 is provided with an auxiliary anode 5,
An auxiliary discharge is generated between the cathode 4 and the cathode 4. The auxiliary anode 5 is formed by printing and baking a conductive paste on the spacer 8, using a metal wire, or depositing it by sputtering. Auxiliary anode 5 and l! It is arranged to intersect with the three-pole lead 2 to form a matrix. A phosphor 9 is provided on the wall surface of the display discharge space 7, and a display anode 10 - a cathode 4
For example, if each cell is painted with red, green, and blue phosphors that emit light in one color, it is possible to display images on a color television. The gas discharge display panel configured as described above is completed after further filling each discharge space with a mixture of one or more rare gases such as Xs, Ar, He, Ne, Kr, etc., airtight from the outside world. do.

FIG. 3 shows the connections of the electrode wiring within the panel and the drive circuit. Inside the broken line is the gas discharge display panel 31.
The cathode 4 is connected via a resistor 3 to a cathode lead 2 wired in a horizontal direction, and is further connected to a cathode drive circuit 14 . The anode 10 is connected to an anode lead 12 that is wired in a horizontal direction, and is further connected to an anode drive circuit 16 .

In FIG. 1, V^1. v^1VA3 is the first
．． Second. This is a voltage waveform applied to the third anode lead and is generated by the anode drive circuit 16. Vxz, VxzyVxa are the first. Second. This is a voltage waveform applied to the third cathode lead and is generated by the cathode drive circuit 13. Vst+VS
21 VS3 is the 1st. Second. The voltage waveform applied to the third auxiliary anode is generated by the auxiliary anode drive circuit 14. t
Since the cathode pulse 23 is applied between l<tz, K
An auxiliary anode-cathode discharge occurs in the cell above l. At this time, since the auxiliary anode pulse 22 is applied to the discharge cells (K1.31) and (Kl, S3), the discharge changes to an anode-cathode discharge. Regarding this discharge transition, for example, JP-A-52-
123125. In a discharge cell where an anode-cathode discharge has occurred, a display discharge is maintained between the anode and cathode by the sustaining pulse 21 that is subsequently applied to the cathode due to the pilot effect of the residual charge. When the pulse width of the sustain pulse 21 is set to about 0.2 to 0.5 μs, the luminous efficiency of the gas discharge display panel increases. This display discharge includes
Since there is a pulse memory effect, the sustain pulse 21 continues until it disappears. Therefore, the cells in which the display discharge is occurring at time 7 are (Kl, SL), (Kl.

There are four cells: S3), (K2.Sl), and (K3.S2). In order to prevent discharge from occurring between the auxiliary anode 5 and the cathode 4 when the sustain pulse 21 is applied to the cathode, the auxiliary anode 5 is
Then, a discharge prevention pulse 25 synchronized with the sustain pulse 21 is applied. The discharge prevention pulse has a pulse width of 0, 2 to 1 μ
m, an amplitude of about 50-100V is appropriate.

In this embodiment, the sustain pulse 21 was applied only to the cathode, but as shown in FIG. good. In this way, the anode sustain pulse 20. Since the voltage amplitude of each cathode sustaining pulse 21 is reduced, reactive power caused by charging and discharging stray capacitance within the panel can be reduced. Another advantage is that the withstand voltage of the drive circuit can be small.

Further, by making the anode wiring pattern as shown in FIG. 6 and shifting the phase of the anode sustaining pulses 20 applied to adjacent anodes, crosstalk between adjacent cells is reduced and the operating margin is widened. On this occasion.

The wiring pattern of the cathode lead 2 is also made as shown in FIG. 6, and the phase of the cathode sustaining pulse 21 is also matched to the anode sustaining pulse 20.

If the voltage of the anode sustaining pulse 20 is set lower than the one-display (pulse) discharge sustaining voltage, the same display as in the above embodiment can be obtained even if the voltage waveform shown in FIG. 5 is applied.

That is, the anode sustaining pulse 20 is always applied, and the period of display discharge is set depending on the presence or absence of the cathode sustaining pulse 21. In this way, as shown in FIG.
I.

Since the voltage waveform applied to A3 is the same, the drive circuit can be shared. That is, even if the number of anodes is increased, only two anode 1 drive circuits 16 are required.

In addition, in Figures 4 and 5, discharge prevention pulse 2 is applied to the auxiliary anode.
5 is not applied, but it can be applied in the same manner as in FIG. 1 if necessary.

Another embodiment of the present invention will be described with reference to FIGS. 15 and 16. FIG. 15 shows the structure of the gas discharge display panel used in this example. The difference from FIG. 2 is that the anode 10 and the anode lead 10' are connected through a resistor 3'. Additionally, a transition electrode 201 is added. The transition electrodes 201 are short-circuited in all cells,
For example, a metal plate with holes corresponding to the display discharge spaces 7 is used. Resistor 3' is, for example, 10Ω to 2Ω
shall be.

FIG. 16 shows driving waveforms of the panel having the structure shown in FIG. 15. The electrode connection is the same as the third time.

However, the transition electrode 201 is connected to a transition electrode drive circuit (not shown). In FIG. 16, positive pulses are continuously applied to the anode lead 10'.

This continuous pulse has a pulse memory effect.

Further, the positive pulse applied to the transition electrode 201 is for preventing discharge between the anode 10 and the transition electrode 201.

The method of driving a panel to which transitional electrodes are added as in this embodiment is described in detail in, for example, Japanese Patent Application No. 61-203673.

Another embodiment of the present invention will be described with reference to FIGS. 7, 8, and 9.

FIG. 7 is a diagram showing the structure of a gas discharge display panel used in this example. An insulating substrate 1 made of soda glass or the like and a translucent face plate 11 made of soda glass or the like are separated by about 100 to 500 μm.
Xe, Ar, He, N
A cathode 4 made of a material such as nickel is formed by a thick film printing method or the like on a 6-substrate 1 in which one or more rare gases such as E and Kr are sealed. On the face plate 11, an anode 10 is formed using a material such as gold or nickel by a thick film printing method or the like. The cathode 4 and the anode 10 are orthogonal to each other so that the intersection points serve as display pixels. When displaying in color,
A phosphor (not shown) is applied on the face plate 11 in advance.

FIG. 8 is a drive circuit connection diagram of the panel 31. An anode drive circuit 16 is connected to the anode 10 . A cathode drive circuit 13 is connected to the cathode 4 via a resistor 3 and a cathode capacitor 5o. The resistor 3 is preferably about 500Ω to 2MΩ.

The capacitance value of the cathode capacitor 50 is 0 of the stray capacitance of the cathode 4.
．． Set to 8x to 8x. The cathode capacitor 50 may be formed by actually attaching a capacitor, or may be formed on the substrate 1 by a thick film printing technique or the like as shown in FIG.

In FIG. 10, by overlapping the cathode 4 and the cathode drive circuit output terminal 101 with an insulating layer 105 in between, the cathode capacity 5
It forms an o.

FIG. 9 shows the output voltage waveform of the drive circuit. ■＾1y VAST VA3 are respectively 1st and 2nd. The output voltage waveform of the third anode drive circuit 16.

VKll VK2. VKaLtSotL respectively 1st. Second
．． It is an output voltage waveform of the third cathode drive circuit 13. The pulse width of the cathode scanning pulse 23 and address pulse 25 is 1
The pulse width of the cathode sustain pulse 21 is preferably about 0.2 μs to 1 μs.

The voltage values V+r, s of the cathode scanning pulse 23 and the voltage value ■^D of the address pulse 25 are set so as to satisfy the following conditions.

V AD + V xs> V b dr rnax
VAn<Vn, min; VKs<Vn, min
Here, Vbd, max indicates the maximum value within the panel among the discharge starting voltages at each discharge point (the intersection of the anode 10 and the cathode 4). V, mj, and n indicate the minimum value of the cathode drop voltage within the panel at each discharge point.

■＾If D, v, and s are set in this way, the discharge point (KL
, Al).

Discharge occurs at (Kl, A3), and no discharge occurs at other discharge points. At the detour point where the discharge occurs, the pulse discharge continues to occur due to the cathode sustaining pulse 21 that is continuously applied due to the pilot flame effect.

This pulse discharge continues until the cathode sustaining pulse 21 is no longer applied.

〔Effect of the invention〕

In this way, it is possible to reduce the sputtering of the anode that occurs during DC pulse discharge, and also to reduce the negative glow emission observed near the anode.

[Brief explanation of the drawing]

FIG. 1 is a diagram of applied voltage waveforms in a discharge display panel according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a gas discharge display cell used in the embodiment, and FIG. 3 is a diagram showing internal wiring and driving in the panel of the embodiment. Circuit connection diagram, Fig. 4 is an applied voltage waveform diagram of another embodiment, Fig. 5 is an applied voltage waveform diagram of yet another embodiment, Fig. 6 is an l'A pole wiring pattern diagram, and Fig. 7 is a further A perspective view showing the structure of a gas discharge display panel according to another embodiment, FIG. 8 is a drive circuit wiring diagram of the embodiment, FIG. 9 is an applied voltage waveform diagram of the embodiment, and FIG. 10 is a cathode capacitor formation method. FIG. 11 is a top view of the cathode section showing the model circuit diagram of the present invention, and FIG.
The figure is a voltage transfer characteristic diagram of the model circuit, FIG. 13 is an equivalent circuit diagram showing a model of stray capacitance in a discharge cell, and
Fig. 4 is an equivalent circuit diagram when another electrode is included in the above model, Fig. 15 is a cross-sectional view of a discharge cell showing another embodiment according to the present invention, and Fig. 16 is a drive voltage waveform used in the above embodiment. FIG. 2... Cathode lead, 3... Resistance, 4... Cathode, 5...
...Auxiliary anode, 10...Anode, 21...Cathode sustaining pulse, 20￥ IZ Py between Sakima and S Monshokaku Tsugi Otsu Zume 7 Figure/〆 Intestine a Gunmyo circuit broom 2 Ward play Figure 70 Hitomi Figure 77 & b-o Ima

Claims (1)

[Claims] 1. In a pulse memory type DC discharge display panel consisting of gas discharge cells arranged in a matrix, each discharge cell has at least two types of electrodes, and at least one of the electrodes has , a method for driving a gas discharge display panel, which is connected to an electrode lead through a resistor and a capacitor that are parallel to each other, and which applies a voltage pulse to the electrode lead to maintain a pulsed discharge for light emitting display. 2. In a pulse memory DC discharge display panel consisting of gas discharge cells arranged in a matrix, each discharge cell has at least two types of electrodes, and at least one of the electrodes has resistors in parallel with each other. It is connected to the electrode lead through a capacitor and a capacitor, and at the same time a voltage pulse is applied to the above electrode lead, a voltage pulse of the same phase and opposite polarity is applied to the other electrode lead to generate a pulsed discharge for light emitting display on the fiber. A method for driving a gas discharge display panel. 3. A gas discharge display panel consisting of gas discharge cells arranged in a matrix, each discharge cell having at least three types of anodes and cathodes wired in parallel to each other, and an auxiliary anode wired perpendicularly thereto. Using a gas discharge display panel having an electrode, the cathode being wired to the cathode lead through a resistor and a capacitor in parallel with each other, a negative electrode is used to maintain a pulsed discharge for light emitting display between the anode and the cathode. A method of driving a gas discharge display panel that applies voltage pulses to the cathode lead. 4. A method for driving a gas discharge display panel according to claim 3, characterized in that a negative voltage pulse is applied to the auxiliary anode in synchronization with the light emitting display voltage pulse applied to the cathode lead. How to drive the display panel. 5. A gas discharge display panel consisting of discharge cells arranged in a matrix, each discharge cell having at least three types of electrodes: an anode and a cathode wired parallel to each other, and an auxiliary anode wired perpendicularly thereto. and the anode is wired to the anode lead through a resistor and a capacitor connected in parallel to each other. Using a gas discharge display panel, the anode is connected to the anode lead through a resistor and a capacitor connected in parallel to each other. A method of driving a gas discharge display panel that applies a positive voltage pulse to the anode lead. 6. A gas discharge display panel consisting of discharge cells arranged in a matrix, each discharge cell having at least three electrodes: an anode and a cathode wired parallel to each other, and an auxiliary anode wired perpendicularly thereto. Using a gas discharge display panel, the cathode is wired to the cathode lead through a resistor and a capacitor in parallel with each other, a positive voltage pulse is applied to the anode, and a negative voltage pulse of opposite phase is applied to the anode. is applied to the cathode to maintain a pulsed discharge for luminescent display between the anode and the cathode, and the discharge is not maintained by applying only one voltage pulse, and depending on the number of voltage pulses on either one, A method for driving a gas discharge display panel that determines the number of pulse discharges to be generated.