JPH08273548A - Gas-discharge panel - Google Patents

Abstract

PURPOSE: To provide a gas-discharge panel which is enlarged and has a protective film that resists cracking by providing the protective film as islands covering X and Y electrodes, over a dielectric material and opposite at least to a display electrode inside one display cell. CONSTITUTION: A glass substrate is used as a back substrate 10, and stripes of X and Y electrodes 12, 14 (dual indicating electrode 15) are formed on the substrate 10 using screen printing method. Next, using screen printing method a dielectric layer 16 is formed over the substrate 10 including the electrodes 12, 14. Islands of a protective film 18 are formed on the upper surface of the layer 16. An MgO paste in which MgO powders, an MgO binder, and a resin component are blended is used in the protective film 18. The gas-discharge panel 28 comprises the substrate 10 and a front substrate 20 spaced a certain distance by a partition 26 and stacked. The front substrate 20 is provided with an address electrode 22, a phosphor 24, and the partition 26. The space between the substrate 10 and the front substrate 20 is sealed by the partition 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC type gas discharge panel.

[0002]

2. Description of the Related Art A conventional AC type gas discharge panel is composed of a rear substrate and a front substrate. This panel
Display electrodes including X electrodes and Y electrodes are provided on the rear substrate. Further, the display electrodes are formed on the back substrate in parallel with each other and as a pair. Further, a dielectric layer is provided on the upper side of the substrate having the display electrodes so as to cover the display electrodes, and a protective film (MgO) for protecting the dielectric layers from sparks at the time of discharge is provided on the rear substrate. Membrane).

On the other hand, address electrodes are provided on the front substrate so as to be orthogonal to and opposed to the display electrodes. Also,
A partition wall is provided in parallel with the address electrode to keep the space between the front substrate and the rear substrate. A phosphor is applied to a region of the front substrate which is not covered with the address electrodes and the partition walls. The back substrate and the front substrate are sealed with lead glass, and a discharge gas (for example, a mixed gas of Ne and Xe) is present in the sealed space between the back substrate and the front substrate.
Is included in the hundreds of torr.

[0004]

However, when the size of the gas discharge panel is increased, the area for providing the protective film formed on the rear substrate side is also increased, and the occurrence of cracks becomes a problem.

In the conventional gas discharge panel, since the protective film is formed by using the sputtering method, when the film thickness of the protective film is increased, cracks are easily generated on the surface of the protective film. When the protective film is formed using the screen printing method,
Although the protective film can be formed thick, the volume of the protective film is reduced due to evaporation of the resin component contained in the MgO paste when the MgO paste is fired, so that the protective film is cracked.

On the other hand, when the protective film is formed on the dielectric layer provided on the rear substrate side, the dielectric layer and the protective film have different coefficients of thermal expansion, so that distortion occurs especially in the protective film. There is a problem that cracks occur in the protective film due to the generation of this strain. If a crack is generated in the protective film, the discharge voltage of the gas discharge panel is increased when the gas discharge panel is discharged, and a dielectric breakdown due to a spark occurs to deteriorate the insulation resistance.

Therefore, there has been a demand for a gas discharge panel having a protective film which is less likely to generate cracks even if the panel is enlarged to increase the area of the protective film.

[0008]

Therefore, according to the gas discharge panel of the present invention, the X electrodes extending parallel to each other are provided on the upper side of one of the two substrates forming the AC gas discharge panel. A gas discharge panel including a display electrode including a Y electrode, a dielectric layer, and a protective film in order, and a display panel on a dielectric layer in a single display cell facing at least the display electrode in a gas discharge panel. An island-shaped protective film covering the electrodes is provided.

The protective film is preferably provided so as to extend from the outer edge of the X electrode to the outer edge of the Y electrode.

Further, it is preferable that the protective film is individually provided only in a region covering the outer edge to the inner edge of the X electrode and the Y electrode.

[0011]

According to the gas discharge panel of the present invention, the island-shaped protective film covering the display electrode is provided on the dielectric layer so as to face at least the display electrode in one display cell.
Therefore, the area of the portion where the protective film is formed is smaller than that in the case where the protective film is provided over the entire surface of the plurality of display cells as in the conventional case. It is possible to suppress the volume reduction caused when the resin component contained in the MgO paste, which is the material of the film, evaporates. Further, since the contact area between the dielectric layer and the protective film is reduced by using the island-shaped protective film, the occurrence of strain due to the difference in thermal expansion coefficient between the dielectric layer and the protective film is suppressed. Therefore, cracks generated in the protective film can be reduced.

[0012]

Embodiments of the gas discharge panel of the present invention will be described below with reference to the drawings. 1 to 4 are
The shapes, sizes, and positional relationships of the respective constituents are only schematically shown to the extent that the present invention can be understood. Also,
Numerical conditions such as the materials used, the amount used, the processing time, the temperature, the film thickness, and the like described in the following description are only suitable examples within the scope of the present invention. Therefore, it should be understood that the present invention is not limited to only these conditions.

FIG. 1 is a perspective view schematically showing the structure of a gas discharge panel used in the first embodiment of the present invention. In addition, FIGS. 2A to 2D are perspective views schematically showing a process of manufacturing a back substrate which constitutes the gas discharge panel of the first embodiment. In the following description, prior to the description of the structure of the gas discharge panel of the present invention, a method of forming the back substrate used in this embodiment will be described with reference to FIGS.

In the first embodiment, the back substrate 10 is prepared in advance ((A) in FIG. 2). A glass substrate, for example, is used as the back substrate 10. Stripe-shaped X electrodes 12 and Y electrodes 14 extending in parallel to each other are formed on the rear substrate 10 by using a screen printing method (FIG. 2).
(B)). Note that, here, the X electrode 12 and the Y electrode 14 are collectively referred to as the display electrode 15. X electrode 12 and Y
The method of forming the electrode 14 is as follows.

The material for the X electrode 12 and the Y electrode 14 is, for example, Electro Science Laboratory (ESL).
A paste (product name: # 590) manufactured by the company is used to print the paste on the rear substrate 10. After the paste is dried (150 ° C., 15 minutes), the paste is further baked (580 ° C.) to form the X electrode 12 and the Y electrode 14. At this time, for example, when Au is used as the electrode material, the film thickness g of the X electrode 12 and the Y electrode 14 is about 0.
2 μm.

Next, the X electrode 1 is formed by using the screen printing method.
2 and a dielectric layer 1 on a back substrate 10 including Y electrodes 14.
6 is formed ((C) of FIG. 2). Here, the film thickness h of the dielectric layer 16 is set to 20 to 30 μm.

Next, a protective film 18 is formed on the upper surface of the dielectric layer 16 ((D) of FIG. 2). The protective film 16 forms an island-shaped protective film so as to cover the surface portions of the X and Y electrodes 12 and 14. In the first embodiment, the protective film 16 is formed so as to extend over at least the outer edge of the X electrode 12 and the outer edge of the Y electrode 14 and be located above the X and Y electrodes. For example, MgO is used as the material of the protective film 16.
When forming the protective film 16 of MgO, an MgO paste prepared by preparing MgO powder, a MgO binder, and a resin component (eg, ethyl cellulose) is used. This Mg
The O paste is applied to the dielectric layer 16 using a screen printing method.
Printed on the surface and then dried the paste (150 ℃,
15 minutes) and baking (580 ° C.) to form an island-shaped protective film 18
To form. The protective film 18 is also referred to as a MgO film or protective film pattern. In this step, Mg
By drying the O paste, a part of the ethyl cellulose contained in the MgO paste is evaporated. Further, by baking the MgO paste, ethyl cellulose contained in the paste is evaporated. In this embodiment, the film thickness i of the protective film 18 after firing is about 1
0 μm.

Next, the structure of the gas discharge panel will be described with reference to FIG. In addition, although hatching is attached to a part of the drawing, this is a hatched line for clarifying a part of the cross section.

Gas discharge panel 28 used in this embodiment
Is formed by stacking the back substrate 10 and the front substrate 20 formed by the above-described steps with a partition wall 26 at a predetermined distance.

The distance between the X electrodes 12 and the Y electrodes 14 arranged in parallel, that is, the distance e between the X and Y electrodes 12 and 14 is, for example, 50 to 100 μm. For example, gold (Au) is used for the display electrodes. In this case, the film thickness g of the X and Y electrodes is set to about 0.2 μm, and the electrode widths d ₁ and d measured in the direction along the arrangement direction of the X and Y electrodes.
₂ is about 200 μm, for example.

A dielectric layer 16 is provided so as to cover the surface of the rear substrate 10 including the X electrodes 12 and the electrodes 14.
The film thickness h of the dielectric layer 16 is set to 20 to 30 μm.

Further, an island-shaped protective film 18 is provided on the dielectric layer 16 so as to cover the display electrode 15 so as to face at least the display electrode 15 in one display cell.
In addition, in the first embodiment, the protective film 18 is at least X.
It is provided so as to extend from the outer edge of the electrode 12 to the outer edge of the Y electrode 14. The width f of the protective film 18 measured along the arrangement direction of the X and Y electrodes is, for example, about 600 μm, and the distance at which the protective film 18 is separated between adjacent display electrodes is, for example, about 400 μm.

On the other hand, the front substrate 20 has an address electrode 2
2, the phosphor 24, and the partition wall 26 are provided. The address electrode 22 is a display cathode 15 (X electrode 12 and Y electrode 1).
It is provided orthogonal to 4) and facing each other. Phosphor 24
Is the discharge side of the front substrate 20 and the address electrodes 22
And a partition described later. Also, the partition wall 2
6 is provided with a space (space) maintained between the rear substrate 10 and the front substrate 20, and a partition wall 26 seals between the both substrates 10 and 20. A space in which the space between the rear substrate 10 and the front substrate 20 is sealed by the partition wall 26 is called a cell.

Next, a method of driving the gas discharge gas panel (hereinafter, also referred to as a panel) 28 will be described with reference to FIG.

To turn on any cell of this panel 11, first, a negative voltage pulse (1
At the same time as applying 80 V), a positive voltage pulse (80 V) with different polarity is applied to the address electrode 22. At this time, discharge is generated between the address electrode 22 and the X electrode 12. Due to this discharge, electric charges are accumulated on the X electrode 12.

Next, a negative voltage pulse (18
0 V) is applied. At this time, the X electrode 12 and the Y electrode 14
A discharge is generated between them and the phosphor 24 provided on the front substrate 20 side emits light. After that, the X electrode 12 and the Y electrode 14 are provided with a
Voltage pulses are applied alternately.

Next, when ending the light emission period of the panel 28, an erase pulse (about 100 V) is applied to the X electrode 12. After that, no discharge occurs between the X electrode 12 and the Y electrode 14 unless a voltage pulse is applied to the address electrode 22.

As described above, the discharge in this embodiment is
It is performed between the X electrode 12 and the address electrode 22 and between the X electrode 12 and the Y electrode 14.

FIG. 5 is a diagram for explaining the state of cracks occurring in the protective film of the panel of the present invention and the conventional panel. In the figure, (A) is a model diagram schematically showing a state in which a sample, which is manufactured by a conventional back substrate process and has a protective film formed on the entire surface of a dielectric layer, is observed with a microscope.
The sample (A) is 1600 mm on the back substrate 50.
^{A 2} (40 mm × 40 mm square) dielectric layer (not shown) and a protective film 52 are sequentially provided. In the sample of the conventional example,
The film thickness of the dielectric layer is 20 to 30 μm, and the film thickness of the protective film is 5 to 10 μm.

On the other hand, the sample of (B) uses a back substrate corresponding to the first embodiment of the present invention, and is provided with a rectangular dielectric layer and a protective film which are close to the actual surface area of the protective film. There is. And in the sample of (B), three rectangular protective films are formed, and the area of one protective film is about 13.2 mm.
² (0.4 mm width × 33 mm length). The area of one rectangular protective film corresponds to 64 electrodes when converted into the area of the X electrode or the Y electrode which constitutes the actual panel.

As can be understood from FIG. 5, a large number of cracks a are generated on the surface of the protective film 52 of the conventional example. However, on the surface of the sample corresponding to the protective film 54 of the present invention, the crack b is slightly generated at the corner of the rectangle.

As can be understood from the above-described micrograph of the upper surface of the protective film, the cracks generated in the protective film can be reduced by reducing the area of the protective film as in the embodiment of the present invention. It is considered that this is because the volume reduction of the MgO paste, which is caused by firing when forming the protective film, becomes small. Further, by making the area of the protective film smaller than the conventional one, the area of contact of the protective film with the dielectric layer also becomes smaller, so that the strain generated in the protective film due to the difference in thermal expansion coefficient at the boundary surface is also suppressed. .
Therefore, it is considered that the occurrence of cracks is reduced.

Table 1 shows the measurement results comparing the electrical characteristics of the panel used in the first embodiment of the present invention and the conventional panel.

[0034]

[Table 1]

In the panel of the conventional example used in Table 1, the X electrode and the Y electrode are provided on the rear substrate, and the dielectric layer is provided so as to cover the entire exposed surface of the substrate including the X and Y electrodes. . Further, a protective film is provided on the entire surface of the dielectric layer. In this panel, the thickness of the dielectric layer is 20 to 30 μm and the thickness of the protective film is 5 to 10 μm.

On the other hand, the panel of the first embodiment is constructed by using the back substrate manufactured by the above-described back substrate manufacturing process. In the first embodiment, the dielectric layer has a thickness of 20 to 30 μm, and the protective film has a thickness of about 10 μm.
It is as m.

As can be seen from Table 1, in the first embodiment, the ignition voltage was 297V, the sustain voltage was 200V, the discharge current was 4.2 μA, and the brightness was 313 cd.
/ M ² .

On the other hand, in the conventional example, the ignition voltage is 3
The voltage becomes 14 V, the sustain voltage becomes 213 V, the discharge current becomes 4.1 μA, and the brightness becomes 340 cd / m ² .

As can be understood from the measurement results of Table 1, the electric characteristics of the first embodiment are substantially the same as those of the conventional example, and therefore even if the area of the protective film is reduced. It was found that the panel of the first example had substantially the same electrical characteristics as the conventional one.

Therefore, in the first embodiment, as the number of cracks generated in the protective film is reduced, the insulation resistance between the X electrode and the Y electrode is improved, the rise of the discharge voltage is suppressed, and the spark is generated. Dielectric breakdown can also be prevented.

FIG. 3 is a perspective view schematically showing the structure of a gas discharge panel used in the second embodiment of the present invention. In addition, FIGS. 4A to 4D are perspective views schematically showing a process of manufacturing the back substrate which constitutes the gas discharge panel of the second embodiment. In the following description, prior to the description of the structure of the gas discharge panel of the present invention, the method of forming the back substrate will be described with reference to FIGS.

In the second embodiment, the step of forming the X and Y electrodes 12, 14 on the rear substrate using the rear substrate, that is, the steps up to the so-called steps (A) and (B) of FIG.
This is the same as the steps (A) and (B) of FIG. 2 of the embodiment.
Therefore, detailed description is omitted.

In the second embodiment, the X and Y electrodes 12, 1
A dielectric layer 30 covering the X and Y electrodes 12 and 14 is formed on the back substrate 10 including 4 by screen printing (FIG. 4C). At this time, the width f of the dielectric layer 30 measured along the arrangement direction of the X and Y electrodes arranged in parallel is, for example, about 600 μm, and the film thickness h is, for example, about 20 to 30.
μm.

Next, a protective film 32 having the same area as that of the upper surface of the dielectric layer 30 is formed on the upper surface of the dielectric layer 30 by using the screen printing method (FIG. 4D). The method of forming the protective film is the same as the step (D) of FIG. 2 of the first embodiment, which has already been described, and thus detailed description thereof will be omitted. Here, the width of the protective film is the same as the width f of the dielectric layer, for example, about 600 μm, and the film thickness i is, for example, about 10 μm.
μm.

Next, the structure of the gas discharge panel of the second embodiment will be described with reference to FIG. In the second embodiment, the area of the upper surface of the dielectric layer 30 is set to the dielectric layer 16 of the first embodiment.
Is smaller than the area of the upper surface of the. Then, a protective film 32 having the same width as that of the dielectric layer 30 is formed on the dielectric layer 30. At this time, the dielectric layer 30 and the protective film 32
Is preferably provided so as to cover the X and Y electrodes 12 and 14. Therefore, the dielectric layer 30 is not provided between the X and Y electrodes 12 and 14 (display electrode 15) provided on the rear substrate 10 and the adjacent display electrode (not shown). Therefore, the dielectric layers 30 including the adjacent display electrodes 15 are separated (or separated) from each other.

On the other hand, the front substrate 20 has an address electrode 2
2, phosphor 22, and partition wall 26 are provided. Since this front substrate 20 is the same as that of the first embodiment, detailed description is omitted. The gas discharge gas 34 of the second embodiment is formed by stacking the rear substrate 10 and the front substrate 20 so that the address electrodes 22 and the X and Y electrodes 12 and 14 are orthogonal to each other.

In the second embodiment, since the dielectric layer 30 including the display electrode 15 is formed separately (or isolated) from the dielectric layer including the adjacent display electrode, a voltage is applied between the electrodes of the panel. When applied, the electrostatic capacitance between the adjacent display electrodes 15 becomes small, so that the effect that the applied voltage at the time of discharge can be reduced can be expected. In addition, in the second embodiment, when observing the occurrence of cracks in the protective film,
It was found that the state was equivalent to the result of the micrograph described in the first example. Further, the electrical characteristics (ignition voltage, sustaining voltage, discharge current and brightness) are almost the same as those of the first embodiment.

In the above-mentioned first and second embodiments, the example in which the display electrodes (X and Y electrodes) are formed on the rear substrate has been described, but the present invention is not limited to such a structure.
For example, it can be applied to a panel having a structure in which address electrodes are provided on a back substrate. When the address electrodes are provided on the back substrate side, first, the address electrodes are formed on the back substrate, and subsequently, the dielectric layer is formed over the entire surface of the substrate including the display electrodes. Then, a display electrode is formed on the dielectric layer so as to be orthogonal to the address electrode, and the exposed surface of the display electrode is covered with the dielectric layer and the protective film to form a back substrate. The protective film of the present invention can be applied to such a panel. In this case, the address electrodes on the front substrate are unnecessary.

In the first embodiment, the protective film is made of X.
An example was described in which the electrode was formed to extend from the outer edge of the electrode to the outer edge of the Y electrode, but only the region covering the outer edge to the inner edge of the X electrode 12 and the Y electrode 14 is protected. The films 36a and 36b may be formed individually (see FIG. 6).
When such a protective film is formed, the area of the protective film is first
Since it is smaller than that in the second embodiment, it is possible to reduce the occurrence of cracks as compared with the above-described embodiments.

Further, in the second embodiment, an example in which the adjacent dielectric layers are separated from each other has been described.
The dielectric layers 38a and 38b may be separately provided between the Y electrode 14 and the Y electrode 14 (see FIG. 7). In this case, protective films 40a and 40b are provided on the upper surfaces of the separated dielectric layers 38a and 38b, respectively. In this case, the capacitance between the display electrodes 15 is further smaller than that in the second embodiment described above, so that the discharge voltage can be reduced as compared with the above-described embodiment.

[0051]

As is apparent from the above description, according to the gas discharge panel of the present invention, an island which covers at least the display electrode in one display cell and covers the X electrode and the Y electrode on the dielectric. The protective film is provided. Therefore, when the protective film is formed as compared with the conventional case, the volume of the protective film is reduced by the reduction of the area of the protective film, so that the volume reduction of the paste caused by firing is also reduced. Therefore, cracks generated in the protective film are reduced. Also,
Since the contact area between the protective film and the dielectric layer can be reduced, the strain caused by the difference in thermal expansion coefficient is also reduced. Therefore, as the strain is reduced, cracks generated in the protective film can be suppressed. As a result, the insulation resistance between the X electrode and the Y electrode is improved. Further, since the number of cracks in the protective film is reduced, it is possible to prevent an increase in discharge voltage during discharge or to prevent dielectric breakdown due to sparks, so that the service life of the gas discharge panel can be extended. Further, by separating the adjacent dielectric layers from each other, the capacitance between the display electrodes can be reduced, so that the discharge voltage can be expected to be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing the structure of a gas discharge panel showing a first embodiment.

2A to 2D are perspective views schematically showing a process of manufacturing a back substrate which constitutes the gas discharge panel of the first embodiment.

FIG. 3 is a perspective view schematically showing the structure of a gas discharge panel showing a second embodiment.

4A to 4D are perspective views schematically showing a process of manufacturing a back substrate which constitutes the gas discharge panel of the second embodiment.

FIG. 5 is a modeled photomicrograph showing the occurrence of cracks in a protective film.

FIG. 6 is a cross-sectional view of a back substrate provided for explaining a modification of the first embodiment.

FIG. 7 is a cross-sectional view of a back substrate used for explaining a modification of the second embodiment.

[Explanation of symbols]

 10: Rear substrate 12: X electrode 14: Y electrode 15: Display electrode 16, 30: Dielectric layer 18, 32: Protective film 20: Front substrate 22: Address electrode 24: Phosphor 26: Partition 28, 34: Gas discharge panel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Takasaki 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Katsuaki Sakamoto 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Aya Yamanaka 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (3)

[Claims] 1. A display electrode comprising an X electrode and a Y electrode extending in parallel with each other, a dielectric layer and a protective film are sequentially provided on the upper side of one of the two substrates constituting the AC gas discharge panel. In a gas discharge panel having a plurality of display cells, an island-shaped protective film covering the display electrodes is provided on the dielectric layer so as to face at least the display electrodes in one display cell. Gas discharge panel. 2. The gas discharge panel according to claim 1, wherein the protective film is provided so as to extend from the outer edge of the X electrode to the outer edge of the Y electrode. 3. The gas discharge according to claim 1, wherein the protective film is individually provided only in a region covering an outer edge to an inner edge of the X electrode and the Y electrode. panel.