JPH052181A - Liquid crystal display - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a highly reliable liquid crystal display device. [Structure] When a transparent conductive film (electrode) 7 is covered with an insulating film 4 and the conductive member 8 is electrically connected to a circuit board, the conductive member is in contact with the transparent conductive film at a portion where the insulating film 4 is removed. It was smaller than the gained part. [Effect] The conductive member prevents moisture from entering the insulating film removal end, and the transparent conductive film is hard to be damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which a transparent conductive film for leading out an electrode is prevented from being broken even under an environment of high humidity and drastic temperature change.

[0002]

2. Description of the Related Art When mass producing liquid crystal display elements,
A large number of cells are simultaneously formed between the upper and lower plate glasses and then separated into individual cells (for example, see Japanese Patent Laid-Open No. 55-73020). In this case, the sealing portion (sealing portion) that connects the upper plate and the lower plate is located slightly inside the outer shape of the element.

Further, the connection between the terminals of the liquid crystal display element and the liquid crystal driving control circuit is generally made via a conductive rubber or a conductive flexible substrate. In this case, the conductive rubber or the conductive flexible substrate is located slightly inside the outer shape of the element.

[0004]

On the other hand, when the ambient temperature changes rapidly from high temperature and high humidity or from low temperature to high temperature, dew may form on the outer surface of the liquid crystal display element. If this dew condensation occurs when the sealing portion between the upper plate and the lower plate is located slightly inside the element outer shape, that is, the peripheral end faces of the upper plate and the lower plate, the narrow gap between the upper plate and the lower plate causes a water gap. And the transparent conductive film formed on the plate surface is also covered with water. Further, if this dew condensation occurs when there is some clearance between the conductive rubber or the conductive flexible substrate and the element outer shape, that is, the periphery of the upper plate and the lower plate, between the element outer shape and the conductive rubber or the conductive flexible substrate. The narrow gap is filled with water, and the transparent conductive film on the plate surface formed between them is also covered with water. Since these transparent conductive films have substantially the same potential as either the upper plate electrode or the lower plate electrode, the condensed water becomes an electrolytic solution, and the transparent conductive film components such as indium and tin are dissolved and precipitated as ions. It will be easier. As a result, the risk that the transparent conductive film, which is the electrode connecting terminal or the lead wire, will be broken increases.

It is an object of the present invention to provide a liquid crystal display device in which the above-mentioned drawbacks do not occur, that is, terminal disconnection does not occur even in an environment where the humidity is high and the temperature changes drastically.

[0006]

In order to achieve the above object, in the present invention, a part of the transparent conductive film for connecting terminals exposed outside the region where the upper plate and the lower plate are bonded and sealed is joined. It was covered with an insulating film to prevent the transparent conductive film from being covered by an electrochemical reaction.

That is, according to the present invention, the first substrate, the second substrate, the circuit board, the first conductive film provided on the first substrate, and the second conductive film provided on the second substrate. The second
A conductive film, a liquid crystal provided between the first substrate, the second substrate, and the seal portion, and a conductive member that electrically connects the first conductive film and the circuit board. In the liquid crystal display device having at least the above, the entire seal portion is provided inside the peripheral end faces of the first substrate and the second substrate, and the first conductive film is covered with an insulating film, and The insulating film is provided between the seal portion and the first conductive film to the side where the liquid crystal does not exist, and the conductive member is in contact with the first conductive film. The insulating film is removed, and the removed portion of the insulating film is a liquid crystal display device smaller than the portion where the conductive member and the first conductive film can contact each other. Further, the conductive member is Designed to hold down the area around the removed insulating film. Is a liquid crystal display device is further the conductive member is a liquid crystal display device is a conductive rubber, furthermore, the conductive member is a liquid crystal display device is an electrically conductive flexible substrate.

[0008]

In the present invention, since the electrode (conductive film) is covered with the insulating film and the conductive member electrically connecting the electrode and the circuit board is larger than the removed portion of the insulating film, the insulating film is removed. The electrode is less likely to be placed from the end of the part.

[0009]

The present invention will be described below with reference to the drawings. 1 is a sectional view taken along a plane orthogonal to the display surface of Example 1 of the present invention, and FIG. 2 is a sectional view taken along a plane orthogonal to the display surface of Example 2 of the present invention. In FIG. 1, 1 is an upper (electrode) plate and 1'is a lower (electrode)
A plate, 2 is a seal portion for joining and sealing an upper plate and a lower plate, 3 is an alignment film, 4 is an insulating film according to the present invention, 5 is a liquid crystal, 6 and 6'are respectively an upper plate, a lower plate polarizing plate, and 7 Is a transparent conductive film, 8 is a conductive rubber, 9 is a liquid crystal driving circuit board, and 10 is a conductive pattern formed on the circuit board 9. In FIG. 1, the distance between the upper plate and the lower plate (thickness of the liquid crystal layer) is greatly exaggerated. Actually, this distance is about 10 to 15 μm, which is much larger than the thickness of the upper plate 1 or the lower plate 1 ′ itself. Small.

Further, the portion provided with the insulating film 4 (for example, the material is formed of SiO ₂ ) shown in FIG. 1 has a high possibility of dew condensation under conditions such as high humidity and change of outside air from low temperature to high temperature. Therefore, if this portion is the insulating film 4
When not covered, the exposed water is exposed to the dew condensation condition for a long time, and when the electricity is further applied, the dewed water becomes an electrolytic solution to cause an electrochemical reaction to cause components of the transparent conductive film 7, such as indium and tin. Has a high probability of being dissolved as an ion and progressing to a transparent conductive film cutting accident. The present invention can prevent the transparent conductive film from being damaged by the above electrochemical reaction.

In the embodiment shown in FIG. 1, the insulating film 4 is provided from the outside of the seal portion to the seal portion. In contrast,
In the embodiment of FIG. 2, the insulating film 4 is provided on the entire upper surfaces of the substrates 1 and 1 ', and only the necessary portions are removed. As a result, the alignment film 3 is provided on the single base film (insulating film 4), and the reliability is improved. Further, the removed portion of the insulating film 4 is provided smaller than the conductive member 8, and the conductive member 8 presses the end of the removed portion of the disconnection film 4, further improving the reliability. .

In the above embodiment, the upper plate 1 and the lower plate 1'were described as glass, but it goes without saying that the same effect can be obtained by using a plasticized electrode plate.

Further, since the alignment film 3 is cut before the seal portion 2, the reliability is further improved.

That is, the alignment film is usually an organic substance,
Adhesion to the seal is poorer than that of an insulating film such as SiO ₂ which is an inorganic substance.

Further, the alignment film 3 and the insulating film 4 do not have to be made of different materials, and the process can be shortened by forming these two layers of film at the same time by using an appropriate material. Further, by forming the insulating film 4 between the alignment film 3 and the transparent conductive film 7 in FIG. 2 or in an external region which is held by the conductive rubber, the insulating property inside the element or the outside of the conductive rubber is not covered. The insulating property of the part can also be improved.

[0016]

As described above, according to the present invention, a highly reliable liquid crystal display which does not cause a disconnection accident of a connection terminal even when used under bad conditions in which humidity is high and temperature fluctuates drastically and condensation is apt to occur The device is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a surface perpendicular to a display surface according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along a plane perpendicular to a display surface according to a second embodiment of the present invention.

[Explanation of symbols]

1 ... Upper plate, 1 '... Lower plate, 2 ... Seal part, 4
... Insulating film, 5 ... Liquid crystal, 6 ... Upper polarizing plate,
6 '... lower plate polarizing plate, 7 ... transparent conductive film, 8 ...
Conductive rubber, 9 ... Circuit board for driving liquid crystal display element, 1
0 ... Conductive pattern.

Continued front page    (72) Inventor Akio Miyauchi             Hitachi, Ltd. 3300 Hayano, Mobara-shi, Chiba             Mobara Factory

Claims (4)

[Claims] 1. A first substrate, a second substrate facing the first substrate, a circuit substrate, a first conductive film provided on the first substrate, and the second substrate. The second provided on the substrate
A conductive film, a liquid crystal provided between the first substrate, the second substrate, and the seal portion, and a conductive member that electrically connects the first electrode and the circuit board. In the liquid crystal display device having at least the seal portion, the entire seal portion is provided inside the peripheral end faces of the first substrate and the second substrate, and the first conductive film is covered with an insulating film, and The insulating film is provided from between the seal portion and the first conductive film to the side where the enclosed liquid crystal does not exist, and the conductive member and the first conductive film are in contact with each other. The liquid crystal display device, wherein the insulating film is removed from the existing portion, and the removed portion of the insulating film is smaller than the portion where the conductive member and the first conductive film can come into contact with each other. 2. The liquid crystal display device according to claim 1, wherein the conductive member is provided so as to press the periphery of the removed portion of the insulating film. 3. A liquid crystal display device according to claim 1, wherein the conductive member is a conductive rubber. 4. The liquid crystal display device according to claim 1, wherein the conductive member is a conductive flexible substrate.