JPS606063B2 - Self-shifting gas discharge panel and its manufacturing method - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a so-called self-shift type gas discharge panel that has a discharge spot shifting function, and is particularly designed to prevent accidental erroneous discharge caused by uneven distribution of abnormal charges. It concerns a new panel structure and its manufacturing method.

Self-shifting gas discharge panels are generally classified as AC memory-driven plasma displays, and have the function of shifting information written in the form of discharge spots in the same pattern and displaying it stationary at a predetermined position. There is.

However, the electrodes of the panel are naturally coated with a dielectric layer in order to achieve the memory function, but in conventional panels with such a structure, accidental abnormal discharge occurs during operation, causing the inside of the panel to be covered with a dielectric layer. The problem was that the displayed information was disturbed. The form of abnormal discharge is that it appears in the form of a unit discharge spot around a group of discharge spots corresponding to the displayed information, or that it emits light instantaneously like lightning, and then
This appears as a relatively large light emission pattern. Such accidental abnormal discharges can be avoided by adopting the so-called space charge coupling drive method, which actively utilizes the coupling of space charges in the shift operation, which is well known in Tokukan Sho 53-8058. Japanese Patent Publication No. 49-43535 (U.S.P.M.
．． This is particularly noticeable when a so-called wall charge transfer drive method is adopted, which actively utilizes the coupling of wall charges for the shift operation, as shown in No. 3,781,600.

Therefore, it is believed that the cause of this problem is that abnormal charges are accumulated in a polarized state on the surface of the electrode-corresponding power transfer layer at both ends of the shift channel as the shift operation is repeated. FIG. 1 is a diagram schematically showing such uneven distribution of charges, where the axis shows a shift channel with the writing end on the right side of the page, and the vertical axis shows the potential. When the uneven distribution of wall charges becomes significant due to repeated shift operations and exceeds a certain value, the abnormal electric field based on this abnormal wall charge, together with the external electric field such as the shift voltage, induces an avalanche phenomenon in the vicinity. However, abnormal discharge occurs that is not based on the information mentioned above. Now, in order to avoid the above-mentioned abnormal discharge, it is sufficient to provide the electrodes at both ends of the shift channel with a function of discharging the abnormally accumulated charge. The gas discharge panel employs a configuration in which the electrodes at both ends of the shift channel are directly exposed to the gas discharge space, making it impossible to accumulate electric charge.

However, when exposed electrodes as described above are used, the electrode material may be spattered due to ion bombardment during discharge, or oxidation of the electrode may occur during the baking process of the sealing material used to seal the discharge gas space. However, there is a disadvantage that the discharge characteristics near the electrode change and the operating life is short. In addition,
There is also the problem that the upper limit of the write voltage margin is lowered. In other words, when a write voltage is applied to the exposed write electrode, a large current flows there for a relatively long time, so a strong discharge will continue for a relatively long time in the write discharge cell defined by the write electrode. , this discharge causes unnecessary discharge in the adjacent shift discharge cell. Therefore, the upper limit of the write voltage needs to be kept low. On the other hand, the idea of providing pinholes or cracks for discharging charges in the dielectric layer corresponding to the electrodes at both ends of the shift channel was previously proposed by Tokusho No. 54-16431, etc.; There are situations where it is difficult to make panels with good reproducibility.

The present invention provides a new self-shifting gas discharge panel and a method for manufacturing the same, which solves the problems in the slave drive method and panel structure as described above. More specifically, it is an object of the present invention to provide the most practical panel structure and manufacturing method thereof to avoid abnormal charge accumulation at at least one end of the shift channel. Briefly stated, this invention makes part or the whole of the current transfer layer covering the electrode forming the discharge cell at at least one end of the shift channel a porous layer, and a large number of pores in this porous layer. It is characterized in that the abnormal charge is leaked and discharged through. Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings from FIG. 2 onwards.

FIG. 2 is a cross-sectional view of essential parts showing an example of the configuration of a self-shifting gas discharge panel with a meander electrode structure to which the present invention is applied. It has a 2×2 phase configuration as is well known from No. 1, etc. That is, on one of the glass substrates 2 which are arranged opposite to each other with the gas discharge space 1 in between, there are two-phase busbars Y.
2 groups of Y-side shift electrodes yl alternately connected to 1 and Y2
There are i and y2i, and the surface is covered with a dielectric layer 3 and a surface layer 4 of Mg○. Further, on the inside of the other glass substrate 5, there are x side shift electrodes xmi and x2i which are alternately connected to the bus lines X1 and x2 of another two phases, and the surface thereof is also connected to the transfer body layer 6.
and is covered with the surface layer 7 of the M nail. These x-side shift electrodes and Y-side shift electrodes face each other in a relationship offset by half a pitch, and shift discharge cell arrays al, b are formed in such a way that one electrode is shared by an adjacent cell in sequence.
l, cl, dl, a2... are defined. A shift channel 8 is constituted by such a regular arrangement of shift discharge cells, and a write electrode 9 connected to the terminal W is provided at the right end of the shift channel, and a write electrode 9 is provided between the first shift electrode yll and the write discharge cell W. It consists of Now, the structure up to this point is the Tokkan Sho 53-80 referenced above.
It is not much different from the panel configuration described in Publication No. 53.

However, in the present invention, the dielectric cells corresponding to the discharge cells at both ends of the shift channel including the write discharge cell W, that is, the outermost electrodes 9 and y2n that define the write discharge cell W and the end shift discharge cell bn, respectively The structure of the body layer (including the surface layer 4) 3 is different as follows. That is, each of these dielectric layers is provided with a porous portion 11 extending from the surface layer of the dielectric to the green end portion of the electrode. Thus, if the porous portion 11 is provided in the dielectric layer corresponding to the electrodes at both ends of the shift channel as described above, the excess wall charge unnecessary for the shift discharge on the concession layer is removed through the porous portion 11. Write electrode 9
and immediately leaks to the terminal shift electrode y2n.

In short, abnormal charge accumulation that would cause unwanted discharge no longer occurs. To explain this in more detail from the perspective of the above-mentioned wall charge transfer type driving method, FIG. 3 shows the driving voltage waveforms applied to the write electrode terminal W and each shift bus bar, with corresponding symbols. In the figure, SP is a write and shift period, and DP is a display period. As is clear from the drive voltage waveform in FIG. 3, during writing in the period To, a positive write voltage VW is applied to the write electrode 9 and a write discharge occurs, so that the dielectric surface area 7 corresponding to the write electrode is A negative wall charge is formed on top,
A positive wall charge is formed on the dielectric surface area 4 corresponding to the opposing shift electrode yll. In the subsequent shift operation, the voltage of the subsequent shift electrodes is sequentially lowered from the shift potential of Vsh to the ground potential to transfer positive wall charges, so negative charges are left behind on the cell surface after the shift. It will be. As these write operations and shift operations are repeated, the wall charges in the intermediate shift discharge cells are neutralized and eliminated due to polarity reversal each time, so the accumulated effect of the residual charges is compared as shown in Figure 1 above. Although it may be a little small, the negative charge accumulates in the write electrode corresponding portion and becomes negatively charged, and the transferred positive charge accumulates and becomes positively charged in the shift end portion. However, if the porous portion 11 is provided in the transfer body layer corresponding to the write electrode 9 and the terminal shift electrode y2n as in the present invention, the charge on the discharge surface portion will leak to those electrodes through the porous portion, causing erroneous discharge. No abnormal charge accumulation occurs. Next, three methods for forming the porous portion 11 in the dielectric layer corresponding to the electrode as described above will be explained using an example in which the porous portion 11 is applied to the write electrode 9 side.

That is, FIG. 4 shows a cross-sectional view of the write electrode enlarged to explain the first method. In this diagram,
5 is a glass substrate, 9 is chromium (Cr) 9 on a glass substrate
A write electrode having a two-layer structure is formed by vapor-depositing 1 and copper (Cu) 92, and 6 is a dielectric layer formed by vapor-depositing alumina (AI203) material. Such a write electrode 9
are formed by a well-known thin film technique, but in this example, a base Cr layer 91 with a thickness of looOA and an upper Cu layer 92 with a thickness of 1500A are sequentially deposited on the entire surface of the glass substrate 5, and then A predetermined electrode pattern is formed by photolithography. In this case, what should be noted is that the Cu vapor deposited layer 92 is etched slowly to overetch the Cr vapor deposited layer 91 to form eaves of 0.5 mm or more at both ends of the Cu layer. According to such an electrode shape, when the dielectric layer is subsequently deposited, abnormal growth occurs in the dielectric layer in such a way as to enclose air bubbles around the eaves, and as a result, the dielectric layer itself around the edge of the electrode 9 grows. The layer 11 can be made porous. In addition,
The tapered edge portion of the Cu layer 92 has an oblique angle of 8' with respect to the substrate 5 to prevent cracks from forming in the coating dielectric layer 6.
It is considered to be less than 0. Although not shown, all the shift electrodes except for the terminal shift electrode y2n are the same as the write electrode 9 except that the underlying Cr layer is not overetched.
It has almost the same Cr-Cu two-layer structure. Next, the second method for forming a porous portion will be explained. This method employs approximately the same structure as the shift electrode other than the terminal shift electrode described above without making any modification to the electrode shape, but the structure of the dielectric layer is This method is characterized in that the edge of the target electrode is oxidized prior to deposition.

After such oxidation, if a dielectric layer is deposited, abnormal growth will occur in the dielectric layer around the edge green part of the electrode (particularly the lower part of the tapered edge green of the upper Cu layer), starting from this and reaching the surface layer. The abnormally grown portion becomes a porous layer as described above.
In this case, the electrode shape may be a single-layer electrode structure without a taper in the green edge portion. The following third method for forming a porous portion is characterized in that, like the second method, there is no change in the shape of the electrode, and the dielectric layer is vapor-deposited in an oxygen atmosphere.

That is, if the dielectric layer is vapor-deposited in an oxygen atmosphere with a substrate temperature of the glass substrate of 200° C. or higher and a vacuum level of 3×10 −4 Tom or lower, similar to the second method, the structure around the edge of the electrode will be removed. The layer will be porous. In this case, a good porous portion can be formed even if the taper width of the electrode side green portion is 5 mm or more. Note that other electrodes that do not form porous portions may be masked in advance. Although one embodiment of the present invention has been described above, the essence of the present invention is not limited to this embodiment, and various other modifications and extensions are possible.

For example, the porous portion 11 for leaking abnormal charges is
As described in the previous embodiment, it is most desirable to provide the dielectric layer corresponding to the write electrode and the end shift electrode that define the discharge cells at both ends of the shift channel, but when exploring the space charge coupling driving method described above. Since the amount of abnormal charge accumulated is small, especially on the write electrode side, as is clear from Figure 1, it is smaller than on the terminal shift electrode side, and the probability of occurrence of erroneous discharge is low. A sufficient effect can be obtained even if a mass part is installed. However, when adopting the above-mentioned wall charge transfer driving method, abnormal charges accumulate rapidly in a short period of time, so it is preferable to provide the porous portions in the dielectric layer at both ends of the shift channel. In addition, a porous part for IJ may be provided in a predetermined area including the end cells of the shift channel or in the entire dielectric layer.Also, the panel to be applied is as described above. In addition to self-shifting gas discharge panels with this structure, panels with meander-shaped shift channels, panels with an electrode structure in which the number of electrode groups is increased to 2 groups x 2 groups or more, panels with a parallel electrode structure, The present invention is applicable to panels having a matrix electrode structure and a monolithic structure.

Now, as is clear from the above description, the present invention is, in short, an AC memory-driven self-shift type gas discharge panel, in which "an abnormal wall charge is created in a dielectric layer corresponding to an electrode that defines a discharge cell at at least one end of a shift channel. Since a porous wall charge leakage section is provided to prevent accumulation, it is possible to prevent accidental erroneous discharge caused by uneven distribution of abnormal charges peculiar to self-shifting panels.

Further, since the outermost electrode is protected by a dielectric layer, it will not be sputtered during the t-discharge and will not be oxidized during the sealing operation of the gas space.
Therefore, stable characteristics and long-life operation can be achieved. In addition, its manufacturing method is easy and does not require any special work. Therefore, the present invention is extremely useful for improving the performance of AC memory driven self-shifting gas discharge panels.

[Brief explanation of the drawing]

Figure 1 is a charge distribution diagram for explaining the accidental occurrence of abnormal discharge in an AC memory-driven self-shifting gas discharge panel, and Figure 2 is a self-shifting gas discharge with a meander electrode structure to which this invention is applied. 3 is a driving voltage waveform diagram for explaining the operation, and FIG. 4 is an enlarged sectional view of the write electrode to realize the dielectric layer structure in the panel shown in FIG. 2. be. 1: gas discharge space, 2 and 5: glass substrate, 3 and 6: dielectric layer, 4 and 7: surface layer, 8: shift channel, 9: writing electrode, 11: porous part for abnormal wall charge leak, 91 : Chromium (Cr) layer, 92: Steel (Cu) layer. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1 Shift electrodes regularly connected to a plurality of bus bars are coated with a dielectric layer to face a gas discharge space to form a shift channel consisting of a regular arrangement of a plurality of shift electrode cells. In addition, in a self-shifting gas discharge panel in which a write electrode is provided at one end of the shift channel to constitute a write discharge cell, an electrode corresponding to the discharge cell at least at one end of the shift channel including the write discharge cell is provided. A self-shifting gas discharge panel characterized in that a porous portion is provided in the dielectric layer to leak wall charges accumulated on the dielectric layer. 2 Shift electrodes regularly connected to a plurality of busbars are coated with a dielectric layer to face a gas discharge space to constitute a shift channel consisting of a regular arrangement of a plurality of shift discharge cells, and the shift channel In a self-shifting gas discharge panel in which a write electrode is provided at one end to constitute a write discharge cell, an electrode defining a discharge cell at at least one end of a shift channel including the write discharge cell is provided with a cross section that defines an eaves. The eaves are formed by depositing a dielectric layer by vapor deposition on the electrode-arranging surface of the insulating substrate for electrode support, on which the electrode and a plurality of electrodes defining other discharge cells are regularly arranged. A method for manufacturing a self-shifting gas discharge panel, characterized in that a porous portion is formed in a dielectric layer corresponding to an electrode. 3. The electrode corresponding to the porous dielectric layer is formed by laminating a second metal thin film having a width wider than the width of the metal thin film on a first metal thin film serving as a base layer. A method of manufacturing a self-shifting gas discharge panel according to claim 2. 4 Shift electrodes sequentially and regularly connected to a plurality of busbars are coated with a dielectric layer to face a gas discharge space to constitute a shift channel consisting of a regular arrangement of a plurality of shift discharge cells, and the shift channel In a self-shifting gas discharge panel in which a write electrode is provided at one end to constitute a write discharge cell, the surface of the electrode defining the discharge cell at at least one end of the shift channel including the write discharge cell is oxidized; A dielectric layer corresponding to the oxidation electrode is formed by vapor deposition on the electrode arrangement surface of an electrode support insulating substrate on which a plurality of electrodes defining the oxidation electrode and other discharge cells are regularly arranged. A method for manufacturing a self-shifting gas discharge panel, characterized in that a porous portion is formed inside the panel. 5 Shift electrodes sequentially and regularly connected to a plurality of busbars are coated with a dielectric layer to face a gas discharge space to constitute a shift channel consisting of a regular arrangement of a plurality of shift discharge cells, and the shift channel In a self-shift gas discharge panel in which a write electrode is provided at one end to constitute a write discharge cell, the remaining electrode-compatible surface other than the electrode defining the discharge cell at at least one end of the shift channel including the write discharge cell. By depositing a dielectric layer material in an oxidized deposition atmosphere while masking the electrode, a dielectric layer having a porous portion corresponding to the unmasked electrode is formed. A method for manufacturing a self-shifting gas discharge panel featuring features.