JPH0729499A - Electrode assembling structure for porous electrode plate type display discharge lamp - Google Patents

Abstract

PURPOSE:To reduce power loss and enhance the light emitting efficiency of a display device by forming a dot adhesive part between electrodes, adhering two electrode plates to each other, and limiting the thickness of the adhesive part to a specified value or lower. CONSTITUTION:Two porous discharge electrode plates 1, 2 are adhered to each other by a dot adhesive part 9 having a small area. The adhesive part 9 is formed in only a part of the boundary part with the adjacent hole. The contact area of the two electrode plates 1, 2 through the adhesive part 9 is extremely small, and the electrostatic capacity is thus also minimized. The height of the adhesive part 9, or the clearance between the electrode plates 1, 2 is limited to several mum to about 20mum or lower. The presence of the clearance, when it is within this range, never cause a problem of unnecessary discharge or crosstalk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode assembly structure for a perforated electrode plate type display discharge tube which is a kind of display discharge tube.

[0002]

2. Description of the Related Art FIG. 3 shows the structure of a discharge tube for display according to the inventions of prior applications (1991 patent application No. 356127 and 1992 patent application 74603). The feature of this discharge tube is that two perforated electrode plates whose surfaces are covered with an insulating layer 10 are used as a pair of discharge electrode plates A1 and B2, and a sufficient AC voltage for gas discharge is applied between the electrodes, The discharge is excited inside the hole and used for display or illumination. Figure 3
Then, a large number of holes 3 provided in the two discharge electrode plates 1 and 2
Must have their corresponding holes perfectly aligned. Therefore, in manufacturing, it is desirable that the two plates are pre-bonded before the subsequent steps. For the adhesion, for example, low melting glass is printed on a screen or the like, and baked at about 600 ° C. to adhere. FIG. 4 is a sectional view of a part of the display discharge tube showing a state of adhesion and the discharge path 8. In this way, if the two electrode plates are bonded in advance with the adhesive layer 4, the linear X electrodes 5 and the Y electrodes will be formed in a later step.
It is extremely easy to make the electrode 6 and the hole 3 coincide with each other, and there is no fear that they will be displaced from each other even when vacuum sealing with frit glass.

[0003]

In the case of the above-mentioned conventional bonding method, a large capacitance is generated between the two electrodes due to the low melting point glass used for the bonding layer 4. Since this capacitance enters in parallel to the discharge path 8 passing through the gas space 7 of the discharge, when an alternating current is applied between both electrodes, the alternating current flowing through this capacitance is Power loss. Usually about 200v between these electrodes,
Since a rectangular wave of 10 KHz to 200 KHz is applied, this loss becomes so large that it cannot be ignored.

[0004]

In order to solve the above-mentioned problems of the prior art, the present invention minimizes the contact area of the low melting point glass for adhesion and at the same time, eliminates unnecessary discharge in the resulting gap. In order to prevent the occurrence of the above problem, we propose a condition that defines the difficulty in distance between two electrodes.

Means for solving the problem and its operation will be described with reference to FIG. 1, which is one of the embodiments of the present invention.
FIG. 1 shows two perforated electrode plates with a small area dot-shaped adhesive portion 9.
The structure shown in FIG. The adhesive portion is formed only in a part of the boundary portion between the adjacent holes.
Although the area of the adhesive portion 9 varies depending on the forming means, the size of the hole, the width of the boundary portion, and the like, it is sufficient if the area is sufficient as a spacer for holding the gap between the two electrode plates. That is, the contact area between the two electrode plates through the adhesive portion 9 is significantly smaller than that in the conventional case where the entire surface other than the holes is used as the contact surface, and therefore the electrostatic capacitance between both electrodes is also reduced.

By the way, when the adhesive portion 9 is a so-called dot-shaped spacer as described above, there is a concern.
The discharge, which has conventionally been generated independently inside each hole, leaks from the gap between the dot-shaped spacers and causes a so-called crosstalk phenomenon in which they interfere with each other. Furthermore, since the new gap becomes the shortest distance between the two electrode plates, there is a concern that an abnormal discharge unrelated to the original discharge may occur here, impairing the display effect. However, in the present invention, it has been confirmed that the above-mentioned concern is not caused at all by setting the height of the spacer to a certain value or less.

Normally, the gas filled in this type of discharge tube is
In the case of a monochromatic type in which the emission color of discharge is used for direct display, a mixture of a small amount of argon, etc., with neon at the center is used.
Enclose 0 to 450 torr. In the case of a color type that utilizes the coloring of phosphors by ultraviolet rays, a mixture of xenon and helium is also filled at the same gas pressure. By the way, there is a well-known Paschen's law for the voltage that excites the discharge between the pair of electrodes, and the distance between the electrodes and the gas pressure. If the gas pressure is kept constant, the distance between the electrodes that can excite the discharge at the lowest voltage Has an optimum value, and it is known that the discharge start voltage is high regardless of whether the distance is longer or shorter. By the way, it has been confirmed that when the above gas is sealed at the above gas pressure, the discharge start voltage becomes minimum when the distance between the electrodes is 100 to 150 μm, and if this is set to 10 to 20 μm, almost no discharge occurs.

When there is a gap between adjacent independent discharge spaces, if the gap is large, there is a so-called crosstalk phenomenon in which discharges interfere due to diffusion of charged particles and metastable atoms, but the gap is negative. It has been confirmed that when the thickness is smaller than the thickness of the glow, its diffusion is significantly suppressed. By the way, the thickness of the negative glow when the above gas is sealed at the above gas pressure is about 10 to 20 μm from the negative electrode side.
Is. Therefore, if the gap is less than this, there is no concern of crosstalk.

From the above theoretical consideration and experiment, in the present invention, the dot-shaped adhesive portion is formed between the electrode plates to bond the two electrode plates, and the thickness of the adhesive portion is set to about 20 μm or less. By doing so, an electrode assembly structure is proposed in which the capacitance between electrodes is small and the crosstalk between discharge spaces is small.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is one of the embodiments of the present invention.
The adhesive portion 9 is made of the low melting glass ink and the discharge electrode plate 1 or 1
After printing by screen printing on both No. 2 and No. 2, they are dried, and after aligning the positions of both electrode plates, they are baked at about 600 ° C. to adhere. The position of the adhesive portion 9 may be different from the position shown in FIG. 1 depending on the shape and size of the hole. Further, since the adhesive portion 9 has a role of preventing the positional displacement of the two electrode plates and a spacer for keeping the gap between the two electrode plates constant,
As long as it plays its role, it is not always necessary that all the adhesive parts are melted and fixed.

The height of the adhesive portion 9, that is, the discharge electrode plates 1 and 2
Is limited to a few μm to about 20 μm or less.
In other words, in this range, the problems of unnecessary discharge and crosstalk do not occur even if there is a gap for the reason described above.

Further, it is desirable that the low-melting-point glass of the adhesive portion 9 be made of a material having a dielectric constant as small as possible in order to reduce the electrostatic capacitance as much as possible. Further, in order to lower the dielectric constant, it is effective to use a porous material after firing.

[0013]

According to the present invention, in a perforated electrode plate type display discharge tube, unnecessary capacitance between the discharge electrodes is significantly reduced, thereby reducing power loss and improving the luminous efficiency of the display device. It can be greatly increased.

[0014]

[Brief description of drawings]

FIG. 1 is an assembly drawing of an embodiment.

FIG. 2 is a sectional view of an example.

FIG. 3 is an assembly diagram of a conventional perforated electrode plate type display discharge tube.

FIG. 4 is a cross-sectional view of a conventional discharge tube for a perforated electrode plate type display.

[Explanation of symbols]

 1 Discharge electrode plate A (including an insulating layer) 2 Discharge electrode plate B (including an insulating layer) 3 Hole 4 Adhesive layer 5 X electrode 6 Y electrode 7 Gas space 8 Discharge path 9 Adhesive part 10 Insulating layer

Claims (1)

[Claims] 1. A metal plate having a plurality of through-holes, all surfaces including the hole inner surface are covered with an insulating layer, the metal plates are stacked, for example, as a pair, and both metal plates are filled with a discharge gas. In a display discharge tube, which is enclosed in a tube, and an AC voltage is applied between the pair of metal plates to excite a gas discharge between the inner wall surfaces of the through hole to perform illumination or image display. When bonding a pair of metal plates as a pair,
The adhesive insulator is formed only on a part of the adhesive surface, and the height of the adhesive insulator is smaller than the optimum inter-electrode distance difficulty for obtaining the minimum discharge firing voltage calculated from the gas discharge principle. For example, the assembly structure of the electrode plate is formed to have a thickness of about 20 μm or less.