JPS6329925B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a gas discharge panel and a method for driving the same, and more particularly to a method for extending the life and increasing the operating margin in a surface discharge type or monolithic type gas discharge panel. It concerns a new panel structure and drive method to achieve this.

(b) Background of the Technology A type of gas discharge panel known as a plasma display panel is a surface discharge type display panel. In this type of gas discharge panel, the electrodes constituting the discharge cells are covered with a dielectric layer and disposed only on one of a pair of substrates that are placed opposite each other with a discharge gas filled space in between. In addition to significantly relaxing the requirements for the gap accuracy of the discharge gas-filled space, by attaching an ultraviolet-excitable phosphor to the inner surface of the cover substrate, which is the other of the substrates constituting the discharge cell, multicolor fluorescent material can be produced. It has the advantage that optical display can be easily performed. However, on the other hand, since the electrodes forming the discharge cells are buried in the dielectric layer, various problems arise in terms of manufacturing and discharge operation.

(c) Conventional technology and problems This type of surface discharge type gas discharge panel uses thin film technology to sandwich a dielectric layer on one substrate.
A panel is known in which an electrode and an X electrode are arranged to cross each other, the X electrode is further covered with a dielectric layer, and the surface thereof is covered with a protective layer of MgO. However, in this panel, because the Y electrode and the X electrode are arranged with a step difference, the X-Y
Current concentration occurs at the edge of both electrodes at the electrode intersection. As a result, the dielectric layer and surface protective layer near the affected area may be locally heated, resulting in local thermal alteration or recrystallization, or in some cases, cracking may occur, resulting in fluctuations in operating voltage and reduction in withstand voltage. There were also disadvantages such as shortening the lifespan. Additionally, in order to suppress thermal damage to the dielectric layer due to local concentration of discharge current as described above, attempts have been made to thicken the dielectric layer using low melting point glass, etc. However, it has the following drawbacks: That is, after the X electrode is disposed on the dielectric layer made of low melting point glass on the Y electrode, the dielectric material between the X and Y electrodes is The layer softens and flows, causing a short circuit between the Y electrode and the X electrode at the intersection,
Also, disconnections occurred.

In order to solve this problem, a panel has been proposed in Japanese Patent Laid-Open No. 78751/1983 by the present applicant. As shown in the plan view of the electrode arrangement in FIG. 1 and the cross-sectional view of the main part of the panel in FIG. Part 2
Vertical discharge sustaining electrodes 2 and 3 having electrodes a and 3a are provided, and both comb-tooth protrusions 2a are closely opposed to each other.
and 3a constitute a discharge sustaining cell Sc. Further, a lateral write electrode 5 is disposed on the pair of discharge sustaining electrodes 2 and 3 with a vapor deposited layer 4 of borosilicate glass or the like interposed therebetween. A surface protective layer 7 consisting of the following is coated. A write discharge cell Wc is formed at each intersection between the write electrode 5 and one of the discharge sustaining electrodes, for example, the electrode indicated by 2. An upper glass substrate 8 for a cover is sealed opposite to the electrode substrate assembly 1 constructed in this way, and a predetermined discharge gas is filled in the gap 9 between them to complete the panel. The operation is to generate a discharge by applying a voltage exceeding the discharge start voltage to the write discharge cell Wc determined between the selected write electrode 5 and the discharge sustaining electrode 2, and to apply that discharge to the adjacent discharge sustaining electrode. In the cell Sc, a sustaining voltage lower than the discharge starting voltage is repeatedly applied alternately to the discharge sustaining electrode pair 2 and 3 constituting the sustaining cell, thereby continuously generating the discharge. In this way, the discharge cell is functionally separated into two types, the write discharge cell and the sustain discharge cell, and the sustain discharge that damages the dielectric layers 4 and 6 continuously over time is generated by using electrodes located on the same surface. By performing this between pairs 2 and 3, current concentration on the opposing electrodes is prevented.

As described above, according to the panel structure described in JP-A-57-78751, damage to the dielectric layer can be reduced and the life span can be extended. However, in this panel, the coating layer of the write electrode 5 is formed from a fairly thick dielectric layer 6 with a thickness of 6 μm and a surface protection layer 7 with a thickness of 0.5 μm, so that the coating layer corresponding to the write electrode is There is a problem in that wall charges generated with discharge are accumulated abnormally, and the abnormal wall charges cause accidental erroneous discharge in the write discharge cell, causing erroneous display. Such erroneous discharge will now be explained in a little more detail. When a discharge is generated in a write discharge cell, charges are accumulated on the surface of the surface protection layer corresponding to the cell and its vicinity. The charge accumulated on the protective layer corresponding to the write discharge cell gradually increases during the subsequent discharge in the discharge sustaining cell.
Eventually, the abnormal electric field based on the abnormal wall charge, together with an external electric field such as a sustaining voltage, induces an avalanche phenomenon in the vicinity of the write discharge cell, resulting in the accidental erroneous discharge as described above.

On the other hand, since the upper dielectric layer is thick, the upper and lower dielectric layers must be manufactured using a thin film technique in order to prevent the above-mentioned short circuit between the upper and lower electrodes, which requires a large number of manufacturing steps. There were drawbacks such as:

(d) Purpose of the Invention In view of the above-mentioned circumstances, the present invention aims to prevent accidental erroneous discharges and to prevent accidental erroneous discharges and to The purpose of this project is to provide a new panel structure and drive method that will make it cheaper and have a longer lifespan.

(e) Structure of the invention A gas discharge panel for achieving the above object is:
A plurality of discharge sustaining electrodes are arranged adjacent to each other on one of a pair of substrates facing each other with a gas discharge space in between, and a dielectric layer is provided thereon in a direction intersecting the discharge sustaining electrodes. In the panel structure having write electrodes arranged in a row, an insulating layer with a thickness of 1 μm or less is provided on the write electrodes, thereby providing an insulating layer corresponding to the write electrodes. Wall charges accumulated on the layer can be leaked to the write electrode and dissipated.

On the other hand, a first driving method for driving the gas discharge panel generates a discharge based on input information between at least one sustain electrode and a write electrode of the selected discharge sustain electrode pair of the panel. At this time, a write voltage having a positive polarity relative to the potential of the discharge sustaining electrode is applied to the write electrode, so that when a write discharge occurs, the insulating layer corresponding to the write electrode is Damage is suppressed by being bombarded only by negative charges, that is, electrons, of the space charges generated with the discharge.

Further, the second driving method of the gas discharge panel is as follows:
When generating a discharge based on input information between at least one sustain electrode of the selected discharge sustain electrode pair and the write electrode, a write voltage having a positive polarity relative to the potential of the discharge sustain electrode is applied to the write electrode. The write electrode is maintained at a higher potential than the sustaining voltage applied to the discharge sustaining electrode when the discharge is applied and the generated discharge is maintained between the selected discharge sustaining electrode pair. As a result, when a write discharge and a sustain discharge occur, the insulating layer corresponding to the write electrode is bombarded only by electrons generated with each discharge, thereby suppressing damage.

(f) Embodiments of the Invention Preferred embodiments of the invention will now be described in detail with reference to the drawings.

FIG. 3 is a cross-sectional view of essential parts showing one example of the gas discharge panel of the present invention, and structurally shows the write electrode 5.
The structure is not much different from the conventional structure except for the insulating layer 11 covering the . Therefore, the constituent parts other than this insulating layer 11 are shown with the same reference numerals as in FIG. 2. The insulating layer 11 is made of MgO with a thickness of 0.5 μm, and is manufactured using a thin film technique such as electron beam evaporation. Further, in this embodiment, the write electrode 5 and the discharge sustaining electrode pair 2, 3
has a thin film three-layer structure of chromium (Cr)-copper (Cu)-chromium (Cr), and the dielectric layer 4 is formed of low melting point glass mainly composed of lead oxide (PbO).

In this way, the covering insulating layer 1 on the write electrode 5 is
According to the panel structure in which 1 is made thinner, charges that are once accumulated on the surface of the insulating layer corresponding to the write electrode due to write discharge and sustain discharge are easily transferred to the write electrode through pinholes in the insulating layer. leak. Therefore, electrodes are not accumulated on the surface of the insulating layer corresponding to the write electrode, and the induction of erroneous discharge as described above is prevented. Further, the number of manufacturing steps and time is smaller than that of the conventional two-layer structure of dielectric layer 6 and surface protection layer 7, and the lower dielectric layer can be manufactured using a thick film technique, so that manufacturing costs can be significantly reduced.

Note that in the above panel configuration, the thickness of the insulating layer 11 is 1 μm as long as it is possible to leak the charges accumulated there onto the write electrode 5.
You can select within the following range. For example, 0.5μm
It is also possible to provide a 0.5 μm low melting point glass or alumina oxide layer under the MgO surface layer to form a two-layer structure like the conventional one. In addition to MgO, calcium oxide (CaO) and strontium oxide (SrO) are also used as materials for the surface layer of the insulating layer 11.
Alkaline earth metals such as Incidentally, it is conceivable to expose the write electrode 5 to the gas discharge space to eliminate any charge accumulation, but in this structure, the MgO surface layer provided on the dielectric layer 4 of the discharge sustaining electrode pair 2 and 3 is is contaminated during the manufacturing process of the write electrode, which has the drawback of making the operating characteristics of the panel unstable.

Next, a driving method for extending the life of the gas discharge panel described above will be explained with reference to the driving voltage waveform shown in FIG. 4 and the electrode arrangement configuration diagram shown in FIG. 1. In FIG. 4, VS1s and VWs are the waveforms of the voltages applied to the selected discharge sustaining electrode 21 and write electrode 51, and VS1n and VWn are the waveforms of the voltages applied to the other unselected discharge sustaining electrode 22 and write electrode 52. The waveform VS2 is the waveform of the voltage applied to the other discharge sustaining electrode 3. As is clear from FIG. 4, the selected discharge sustaining electrode 21 has -
When a sustaining voltage VS of 120V and a write voltage VW of +80V are simultaneously applied to the write electrode 51 and their combined voltage is set above the discharge start voltage, a write discharge occurs in the write discharge cell Wc at the intersection of these electrodes, as in the conventional case. do. This write discharge is accompanied by the generation of wall charges on the surface of the insulating layer corresponding to the write discharge cell, and the wall charges are accumulated extending to the surface of the insulating layer corresponding to the adjacent sustain discharge cell Sc. Therefore, the sustaining voltage VS is subsequently applied to the other discharge sustaining electrode 3.
When the voltage is applied, a discharge occurs in the sustaining discharge cell Sc that has received the inflow of the wall charge, taking over the initial write discharge, and thereafter, all the sustaining electrodes 21, 22, and 3 are given a discharge as shown in the figure. If the sustain voltage VS is repeatedly applied, the discharge of the sustain discharge cell Sc will continue to occur. To erase this discharge, -
This is done by applying a narrow voltage pulse of 120V.

Here, the wall charges accumulated on the surface of the insulating layer corresponding to the selected write electrode 51 when the write discharge and sustain discharge occur will be considered. First, when a write discharge occurs, since the write electrode 51 is at a positive potential, it attracts electrons among the charges generated by the discharge. Therefore, since the surface of the insulating layer on the write electrode is not subjected to positive charges, that is, ion bombardment, there is little risk of damage. In addition,
The negative charge once accumulated on the surface of the insulating layer slowly leaks to the write electrode and disappears due to its thin film thickness as described above. Further, when the next sustaining discharge occurs, the write electrode 51 is at zero potential and is always maintained at a positive potential with respect to the negative potential applied to the sustaining discharge electrode pair 21 and 3. attracts only the electrons from the charge generated by the Therefore, in this case as well, the surface of the insulating layer corresponding to the write electrode 51 is not bombarded by ions. As described above, according to the drive waveform shown in FIG. 4, there is no ion bombardment on the surface of the insulating layer on the write electrode 51 during discharge, thereby preventing damage and further extending the life of the panel.

Note that the relationship between the write voltage VW applied to the write electrode and the sustain voltage VS applied to the discharge sustain electrode pair may be set to voltages with the same polarity, instead of having voltages with opposite polarities as in the above embodiment. However, even in that case, the write voltage VW is selected to be larger than the reference potential of the sustain voltage VS, and the write electrode is set so that a positive potential is always applied to the discharge sustain electrode.

As described above, according to the panel structure and driving method of the present invention, it is possible to achieve a long life and a high operating margin for a surface discharge type gas discharge panel. Therefore, by using a gas that emits a large amount of ultraviolet rays and coating the inner surface of the cover glass substrate 8 with an ultraviolet-excitable phosphor, it is possible to extend the display to multicolor display.

(g) Effects of the Invention As is clear from the above explanation, the gas discharge panel of the present invention has a surface discharge type panel structure in which a write discharge cell and a sustain discharge cell are separated, so that accidental errors in the write discharge cell are prevented. Discharge can be prevented, and as a result, the discharge operation margin can be increased. Furthermore, since the dielectric layer covering the discharge sustaining electrode pair can be manufactured using a thick film technique, the manufacturing process can be provided at low cost. Further, according to the driving method of the present invention, ion bombardment on the surface of the insulating layer corresponding to the write electrode in the gas discharge panel can be completely eliminated, thereby preventing damage and extending the life of the panel.

[Brief explanation of the drawing]

1 and 2 are electrode layout diagrams and a sectional view of essential parts showing a conventional gas discharge panel to which the present invention is applied, and FIG. 3 is a diagram showing a conventional gas discharge panel according to the present invention.
FIG. 4 is a sectional view of a main part showing an example configuration, and is a diagram showing an example of a driving voltage waveform of the present invention for driving the panel. 1: Lower glass substrate for electrode support, 2 and 3:
A pair of discharge sustaining electrodes, 4: dielectric layer, 5: writing electrode, 8: upper glass substrate for cover, 9: discharge gas space, 11: insulating layer, Wc: writing discharge cell,
Sc: Sustain discharge cell, VW: Write voltage, VS: Sustain voltage.

Claims (1)

[Scope of Claims] 1. A plurality of discharge sustaining electrodes arranged in a pair adjacent to each other on one of a pair of substrates facing each other with a gas discharge space in between; 1. A gas discharge panel comprising a write electrode arranged in a direction intersecting a discharge sustaining electrode, wherein an insulating layer with a thickness of 1 μm or less is provided on the write electrode. 2. A plurality of discharge sustaining electrodes each adjacent to each other on one of a pair of substrates facing each other across a gas discharge space, and intersecting with the discharge sustaining electrodes with a dielectric layer thereon. For a gas discharge panel having write electrodes arranged in the direction of the discharge electrode and covered with an insulating layer having a thickness of 1 μm or less, at least one sustain electrode of the selected discharge sustain electrode pair of the panel and a write electrode. A method for driving a gas discharge panel, characterized in that when generating a discharge based on input information between the electrode and the electrode, a writing voltage having a positive polarity relative to the potential of the discharge sustaining electrode is applied to the writing electrode. . 3. A plurality of discharge sustaining electrodes each adjacent to each other on one of a pair of substrates facing each other across a gas discharge space, and intersecting with the discharge sustaining electrodes through a dielectric layer thereon. A method for driving a gas discharge panel comprising write electrodes arranged in a direction and covered with an insulating layer having a thickness of 1 μm or less, the method comprising: at least one sustain electrode of the selected pair of discharge sustain electrodes; When generating a discharge based on the input information between the write electrode and the write electrode, a write voltage having a positive polarity relative to the potential of the discharge sustaining electrode is applied to the write electrode, and the generated discharge is maintained as the selective discharge sustaining electrode. A method for driving a gas discharge panel, characterized in that the write electrode is maintained at a potential higher than a sustaining voltage applied to the discharge sustaining electrode when maintaining the potential between the electrode pair. 4. Claim 1, wherein the insulating layer on the write electrode has a two-layer structure including a lower layer made of a dielectric material and a surface protection layer made of a material with a high secondary electron emission coefficient. Gas discharge panel described in. 5. The gas discharge panel according to claim 1, wherein the insulating layer on the write electrode is made of a material with a high secondary electron emission coefficient. 6 The dielectric layer covering the discharge sustaining electrode pair is
The gas discharge panel according to claim 1, characterized in that it is made of low melting point glass.