JPH10170892A - Image display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of peel-off and a crack due to stress of a common electrode by respectively connecting one end parts of drive electrodes to the common electrode and providing a reticulate pattern on this common electrode. SOLUTION: Although terminal electrodes 15 of cathode electrodes 9K side are provided separately corresponding to respective cathode electrodes 9K, the terminal electrode in an anode electrode 9A side is made the common electrode 16 to which all anode electrodes are connected. This common electrode 16 is formed by the reticulate pattern. When the common electrode 16 is formed by the reticulate pattern, time stress hardly be stored in film, and the crack and peel-off are suppressed. Further, though the common electrode 16 of the reticulate pattern is formed easily by printing conductive paste, e.g. golden paste, at this time, a width of lines constituting a net is preferred to be made 200-500μm. Thus, the peel-off and crack of the common electrode 16 are prevented, and the common electrode without disconnection of wire and with high reliability is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display panel in which one of driving electrodes (anode or cathode) is connected to a common electrode, for example, an electro-optical material layer is driven by using plasma to display an image. The present invention relates to improvement of an image display panel (so-called plasma address display panel) to be performed.

[0002]

2. Description of the Related Art For example, as a method for increasing the resolution and contrast of a liquid crystal display, a method of providing an active element such as a transistor for each display pixel and driving the same, that is, a so-called active matrix address method is known. is there.

However, in this case, since it is necessary to provide a large number of semiconductor elements such as thin film transistors,
In particular, when the area of the display is increased, there is a concern about the yield problem, and there is a problem that the cost is inevitably increased.

Therefore, as a means for solving this problem,
A method has been proposed in which discharge plasma is used as an active element instead of a semiconductor element such as a MOS transistor or a thin film transistor.

[0005] An image display panel (hereinafter, referred to as a plasma address display panel) that drives liquid crystal using the discharge plasma includes a liquid crystal layer that is an electro-optical material layer and a plasma cell that discharges plasma. , Adjacent to each other via a dielectric thin plate made of glass or the like.

In the above-mentioned plasma addressed display panel, the plasma cell is divided into linear plasma chambers by partition walls, the plasma chambers in which plasma discharge is performed are sequentially switched and scanned, and the transparent electrodes opposed to each other with the liquid crystal layer interposed therebetween. The liquid crystal layer is driven by applying a signal voltage in synchronization with this.

[0007]

By the way, not only in the above-mentioned plasma addressed display panel but also in an image display panel such as a normal plasma display, it is possible to simplify the connection to an external circuit by using common electrodes. Are being considered.

For example, in a plasma addressed display panel, a cathode electrode among discharge electrodes is used as an individual electrode, an anode electrode is shared, and a flexible wiring board for external connection is joined to the common electrode.
This is supported.

In the case of adopting such a configuration, it is necessary to form the pattern of the common electrode to a certain extent and to make the electric resistance sufficiently small. If the electric resistance of the common electrode is large, the resistance value up to the anode electrode at the position from the flexible wiring board changes, and uniform discharge becomes difficult.

However, if this wide common electrode is formed as a so-called solid pattern, cracks are likely to occur due to stress due to mismatch in the coefficient of thermal expansion between the substrate glass and the solid pattern common electrode. When the cover glass is formed in such a manner, a crack may occur along the edge of the cover glass to cause disconnection. Further, when the above-mentioned stress is applied to the interface between the solid pattern common electrode and the substrate glass, a situation occurs in which the common electrode peels off along the portion where the flexible wiring board is joined.

The present invention has been proposed to solve such a problem, and an object of the present invention is to provide an image display panel free from cracks due to peeling of the common electrode and stress.

[0012]

In order to achieve the above-mentioned object, the present invention provides a method for forming a plurality of drive electrodes substantially parallel to each other on one principal surface of a substrate. In the image display panel connected to the common electrode, the common electrode has a mesh pattern.

In the network pattern, unlike the solid pattern, stress does not easily accumulate in the film, and the possibility of cracking is extremely small.

Further, the stress applied to the interface between the common electrode material and the substrate is reduced, and the common electrode is hardly peeled off.

Further, when adhesion by an anisotropic conductive film or the like is considered, since the surface has moderate irregularities, the adhesion is also improved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

This embodiment is an example in which the present invention is applied to a plasma addressed display panel. As shown in FIGS. 1 and 2, an electro-optical display cell 1, a plasma cell 2, and a dielectric sheet 3 interposed therebetween. And a so-called flat panel structure.

The dielectric sheet 3 is made of thin glass or the like and functions as a capacitor by itself. Therefore, in order to sufficiently secure the electrical coupling between the electro-optical display cell 1 and the plasma cell 2 and to suppress the two-dimensional spread of electric charges, it is preferable that the dielectric sheet 3 is as thin as possible. Specifically, for example, a thin glass plate having a thickness of about 50 μm is used.

The electro-optical display cell 1 is formed by bonding a glass substrate (upper substrate) 4 on the dielectric sheet 3 with a predetermined gap maintained by a spacer 6.

The gap between the dielectric sheet 3 and the upper substrate 4 is filled with a liquid crystal material as an electro-optic material, and a liquid crystal layer 7 is formed. In addition, as the electro-optic material, a material other than the liquid crystal can be used.

Here, the dimension of the gap between the upper substrate 4 and the dielectric sheet 3 is, for example, 4 to 10 μm, and is kept substantially uniform over the entire display surface.

On the surface of the upper substrate 4 facing the dielectric sheet 3, a plurality of data electrodes 5 made of a transparent conductive material and extending in the row direction, for example, are arranged in parallel in the column direction while maintaining a predetermined interval. Are arranged.

On the other hand, the plasma cell 2 is composed of the dielectric sheet 3 and a glass substrate (lower substrate) 8 disposed below the dielectric sheet 3.

On a surface of the lower substrate 8 facing the dielectric sheet 3, a plurality of anode electrodes 9A and cathode electrodes 9K extending in a direction orthogonal to the data electrodes 5, that is, in a column direction.
Are alternately arranged in parallel while maintaining a predetermined interval, and constitute a discharge electrode group as a drive electrode.

The center of the upper surface of each of the anode electrode 9A and the cathode electrode 9K is extended along the electrodes.
A partition 10 having a predetermined width is formed. And each partition 1
The top of 0 is in contact with the lower surface of the dielectric sheet 3, and the gap between the lower substrate 8 and the dielectric sheet 3 is kept substantially constant.

Further, the dielectric sheet 3 has a frit seal 11 made of low melting point glass or the like at the outer peripheral edge.
Accordingly, the plasma cell 2 is hermetically bonded to the lower substrate 8, and the plasma cell 2 is configured as a closed space.
An ionizable gas such as helium, neon, argon, or a mixture thereof is sealed in the closed space.

In the above-mentioned plasma addressed display panel, each partition 10 is provided in the gap between the lower substrate 8 and the dielectric sheet 3.
Are formed in parallel in the row direction. This discharge channel 12 is orthogonal to the data electrode 5.

Therefore, each data electrode 5 is a unit for driving a column, and each discharge channel 12 is a unit for driving a row. As shown in FIG.

In the plasma addressed display panel having the above structure, when a driving voltage is applied between the anode electrode 9A and the cathode electrode 9K corresponding to a predetermined discharge channel 12, the gas sealed in the discharge channel 12 is discharged. When ionized, plasma discharge occurs and is maintained at the anode potential.

When a data voltage is applied to the data electrode 5 in this state, the data voltage is applied to the liquid crystal layer 7 corresponding to the plurality of pixels 13 arranged in the column direction corresponding to the discharge channel 12 in which the plasma discharge has occurred. Written.

When the plasma discharge ends, the discharge channel 12 becomes a floating potential, and the data voltage written in the liquid crystal layer 7 corresponding to each pixel 13 is held until the next writing period (for example, after one field or one frame). Is done. In this case, the discharge channel 12 functions as a sampling switch, and the liquid crystal layer 7 of each pixel 13 functions as a sampling capacitor.

The liquid crystal operates by the data voltage written in the liquid crystal layer 7, and display is performed in pixel units. Therefore, the discharge channel 12 for generating the plasma discharge
Are sequentially scanned, and a data voltage is applied to each data electrode 5 in synchronization with the scanning, whereby the liquid crystal layer 7 is driven in the same manner as in the active matrix addressing method, and a two-dimensional image can be displayed.

The above is the basic configuration of the plasma addressed display device. In this plasma addressed display device, as described above, the periphery is sealed by the frit seal 11 as shown in FIG. It is necessary to bond a dielectric sheet (thin glass) 3.

At this time, the partition 10 formed on the discharge electrode 9 needs to be formed slightly apart from the frit seal 11, and in this region, a cover glass 14 is formed to cover these electrodes. The area where the cover glass 14 is formed is a hatched area in FIG.

In addition, the discharge electrodes (anode electrodes 9A,
In order to connect the cathode electrode 9K) to an external drive circuit,
The terminal electrode 15 is formed as an external lead electrode,
One end is connected to a discharge electrode (anode electrode 9A, cathode electrode 9K), and the other end is a frit seal 1
1 and drawn out of the plasma cell 2.

The discharge electrodes (anode electrode 9A or cathode electrode 9K) are formed in stripes by applying a paste containing Ni or Al and baking the paste. This discharge electrode is a so-called rough film.

On the other hand, the terminal electrode 15 is made of gold (Au) or silver (A) in consideration of the adhesion to the frit seal 11 and the like.
The paste is formed by applying and firing the paste of g). In addition, as a paste used at this time, a gold paste which does not cause migration is preferable.

In this embodiment, the terminal electrodes 15 on the side of the cathode electrode 9K are individually provided corresponding to the respective cathode electrodes 9K. On the side of the anode electrode 9A, a common electrode to which all the anode electrodes 9A are connected is provided. 16 is set.

The common electrode 16 has a wide pattern, and its electric resistance is suppressed to a small value.

Usually, the common electrode 16 is formed as a so-called solid pattern. However, in that case, cracks and peeling become problems.

Therefore, here, the common electrode 16 is formed in a mesh pattern (mesh). If the common electrode 16 is formed in a mesh pattern, stress is unlikely to accumulate in the film, and cracks and peeling are suppressed.

The common electrode 16 having a mesh pattern is
It is easily formed by printing a conductive paste, for example, a gold paste. At this time, it is preferable that the width of the line forming the mesh is 200 to 500 μm. Also,
The mesh pattern does not need to be a complete mesh, and may be in a state where the mesh is crushed due to, for example, insufficient printing accuracy or sagging during firing. In short, it is only necessary that a mesh-like uneven pattern is formed.

The common electrode 16 is usually connected to a flexible wiring board for connection to a drive circuit. This flexible wiring board is mechanically joined to the common electrode 16 by being pressure-bonded via an anisotropic conductive film, and is simultaneously electrically connected.

Further, a cover glass may be formed to cover the common electrode 16, so that the surface of the common electrode 16 is protected from moisture, dirt and the like.

When the common electrode 16 has a solid pattern, if the common electrode 16 is covered with the cover glass as described above, the stress due to the sintering of the cover glass is superimposed, and cracks are generated at the edges of the cover glass, which may cause disconnection.

On the other hand, if the common electrode 16 is formed in a mesh pattern, the possibility of cracking becomes extremely small even when stress due to sintering of the cover glass is superimposed.

Further, in the portion where the flexible wiring board is joined, the stress applied to the interface between the material forming the common electrode 16 and the lower substrate 8 (glass) is reduced, and the portion is not easily peeled.

Further, in the case of bonding by pressure bonding with an anisotropic conductive film, it is preferable that the surface has moderate irregularities because the adhesion is improved, and this is also preferable.

The specific embodiment to which the present invention is applied has been described above. However, it is needless to say that the present invention is not limited to this example, and various modifications are possible.

For example, the plasma address display panel has been described as an example, but the image display panel can also be applied to an ordinary plasma display panel or the like.

[0051]

As is apparent from the above description, according to the present invention, peeling and cracking of the common electrode can be prevented, and a highly reliable image display device without disconnection can be provided. It is.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a configuration example of a plasma addressed display device with a part cut away.

FIG. 2 is a schematic sectional view illustrating a configuration example of a plasma addressed display device.

FIG. 3 is a schematic diagram showing an arrangement of data electrodes, discharge electrodes, and discharge channels.

FIG. 4 is a schematic plan view schematically illustrating a planar arrangement of terminal electrodes and a common electrode.

[Explanation of symbols]

1 electro-optical display cell, 2 plasma cell, 3 dielectric sheet, 4 upper substrate, 5 data electrodes, 7 liquid crystal layer, 8
Lower electrode, 9A anode electrode, 9K cathode electrode,
10 partition, 11 frit seal, 14 cover glass, 15 terminal electrode, 16 common electrode

Claims (3)

[Claims] 1. An image display panel comprising a plurality of substantially parallel drive electrodes formed on one principal surface of a substrate, and one end of each of the drive electrodes connected to a common electrode. An image display panel having a mesh pattern. 2. The image display panel according to claim 1, wherein a flexible wiring board for external connection is joined to said common electrode via an anisotropic conductive film. 3. A dielectric thin plate is disposed on the substrate with a predetermined gap, and a plasma cell is formed by sealing the periphery with a sealing portion. The image display panel according to claim 1, wherein a second substrate on which an electrode substantially orthogonal to the electrode is formed is overlapped via an electro-optic material layer.