JPH02304530A - Color liquid crystal display element - Google Patents

Abstract

PURPOSE:To prevent the rupture of a cell and the disconnection of a band- shaped transparent electrode at the time of peeling an adhesive by providing a reinforcing seal between the surface part of a second transparent substrate projecting from a first transparent substrate and the end face part of the first transparent substrate. CONSTITUTION:Adhesive seals 6a and 6b serving also as spacers are applied to the peripheral parts of surfaces facing each other of a pair of transparent substrates 1a and 1b and adhered and hardend to seal a liquid crystal 7. An epoxy resin reinforcing seal 8 is linearly applied between the surface part projecting from the first transparent substrate 1a of the second transparent substrate 1b and the end face part of the transparent substrate 1a by a dispenser and is hardened. This reinforcing seal 8 has a very high adhesion strength since transparent substrates 1a and 1b are directly adhered to each other without interposing an organic transparent smooth layer 3. Thus, the fear of rupture of the liquid crystal cell and the danger of disconnection of a band-shaped transparent electrode 4a crossing over the sealing part 6b are eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a color liquid crystal display element using a transparent substrate having a smooth layer provided on a color filter layer.

BACKGROUND ART In order to realize a color liquid crystal display element, it is necessary to form a color filter layer on the inner surfaces of a pair of transparent substrates that constitute a liquid crystal cell. In order to prevent voltage drop in the color filter layer of the driving voltage for driving the liquid crystal, a method of configuring a transparent electrode on the color filter layer is common. There is also a method of forming a smooth layer of a transparent organic film between the color filter layer and the transparent electrode in order to reduce unevenness on the surface of the color filter layer and prevent display unevenness. However, although this organic transparent smooth layer is extremely effective in making display image quality uniform, it lacks adhesion with transparent electrodes and liquid crystal cell sealants, and the reliability of color liquid crystal display elements is not always guaranteed. It wasn't perfect.

A conventional example will be described below with reference to the drawings.

FIG. 3 is a sectional view showing the structure of a conventional color liquid crystal display element. This is an example of what is generally called a simple matrix color liquid crystal element. Transparent substrates 1a facing each other
, lb, a color filter layer 2 is formed on one side of the transparent substrate 1a. Color filter layer 2 is printed,
It can be painted in multiple colors such as red, green, and blue (R, G, B) using methods such as electrodeposition and dyeing. In order to reduce the unevenness of the color filter layer 2, an organic transparent smooth layer 3 is formed thereon.
is formed. This organic transparent smooth layer 3 is applied over the entire surface by a spinner method or a roll coater method. As the material, resins such as acrylic, urethane, and polyimide are used. A transparent electrode layer is deposited on the organic transparent smooth layer 3 by sputtering and etched into a predetermined pattern to form a band-shaped transparent electrode 4a. In FIG. 3, a plurality of strip-shaped transparent electrodes 4a are arranged separately at right angles to the depth direction, but this state is not illustrated.

On the other hand, a band-shaped transparent electrode 4b is also formed on the transparent substrate 1b on the opposite side so as to be perpendicular to the band-shaped transparent electrode 4a. However, this is formed directly on the transparent substrate 1b. Orientation control films 5a and 5b are printed and formed on the display portions of the transparent substrates 1a and 1b, and subjected to a rubbing treatment. transparent substrate 1a,
With the transparent substrates 1a and 1b facing each other, adhesive seals 6 which also serve as spacers are provided on the four peripheral parts of the opposing surfaces, and a liquid crystal 7 is sealed between the transparent substrates 1a and 1b. The color liquid crystal display element is then completed by attaching a polarizing plate, mounting a driver LSI, and attaching a backlight.

Problems to be Solved by the Invention In the conventional color liquid crystal display device as described above, the biggest problem is that the adhesive strength at the interface between the organic transparent smooth layer 3 and the adhesive seal 6 is not very strong. In other words, the smoother the surface of the organic transparent smooth layer 3, the better the display performance, but on the contrary, the adhesive strength decreases.Compared to the adhesive strength without the organic transparent smooth layer 3, it is 1/2 to 115.Adhesion If the strength is weak, it will cause the liquid crystal cell to burst, significantly impairing its reliability.In addition, as in the conventional example shown in FIG. In recent years, especially with the advent of 5TN (super twisted nematic) liquid crystal and ferroelectric liquid crystal, smoothness of the inner surface of liquid crystal cells has become increasingly required. A color filter layer is essential for colorization,
The quality of the smoothing greatly influences display performance. On the other hand, there is a need for a solution to the contradiction that the smoother the seal, the more the adhesive strength of the seal is sacrificed.

The present invention was made in view of the above problems, and an object of the present invention is to provide a highly reliable color liquid crystal display element by improving the adhesive strength of the seal.

Means for Solving the Problems In order to achieve the above object, the present invention provides a plurality of color filter layers on a first transparent substrate of a pair of opposing transparent substrates, and a color filter layer on the color filter layer. An organic transparent smooth layer is provided, a transparent electrode is provided on the organic transparent smooth layer, and an adhesive seal is provided on the periphery of the opposing surfaces of the pair of opposing transparent substrates to encapsulate a liquid crystal. The present invention is characterized in that a reinforcing seal is provided between the surface portion of the transparent substrate protruding from the first transparent substrate and the end surface portion of the first transparent substrate.

Effect: By adding the reinforcing seal as described above, the adhesive strength between the opposing transparent substrates is significantly improved, eliminating the problem of liquid crystal cell rupture, and preventing disconnection of the transparent electrode across the seal. The danger will also be eliminated.

Example Below, regarding a color liquid crystal display element according to an example of the present invention,
This will be explained with reference to the drawings.

(Example 1) FIG. 1 is an explanatory diagram of a color liquid crystal display element in a first example of the present invention.

FIG. 1A is a plan view thereof, and FIGS. 1B and 1C are sectional views taken along line AA' and line BB' in FIG. 1A, respectively. The method of processing the pair of transparent substrates 1a and 1b constituting the liquid crystal cell is exactly the same as in the conventional example. That is, an organic transparent smooth layer 3 is formed on the entire surface of the transparent substrate 1a, covering the color filter layer 2. Further, a band-shaped transparent electrode 4a is formed thereon, and these three layers are shown together in FIGS. 1B and 1C. - There is also a band-shaped transparent electrode 4b on the transparent substrate 1b facing the opposite side, but this is also not shown because it is similar to the conventional example.

An alignment control film 5a is provided on the display portion of both constituent substrates.

5b is printed and subjected to a rubbing process, but this is also not shown because it is the same as in the conventional example shown in FIG.

In order to form a liquid crystal cell by bonding the opposing transparent substrates 1a and lb through the above steps, a pair of transparent substrates 1a and lb are bonded together.
Adhesive seal 6 that also serves as a spacer on the periphery of the facing surface of b
A and 6b are applied, adhesively cured, and liquid crystal 7 is encapsulated. A printing method is used as a method for applying the adhesive seals 6a and 6b, and an epoxy resin or the like is used as the material.

Further, a reinforcing seal 8 is applied linearly between the surface portion of the second transparent substrate 1b protruding from the first transparent substrate 1a and the end surface portion of the transparent substrate 1a, and then hardened. This reinforcing seal 8 directly adheres to the transparent substrates 1a and 1b without intervening the organic transparent smooth layer 3, so that the adhesive strength is extremely strong. The application method is performed using a dispenser. Moreover, epoxy resin or the like is used as the material.

In the color liquid crystal display element configured as described above, the adhesive strength between the two transparent substrates 1a and lb is increased by providing the reinforcing seal, so there is no risk of the liquid crystal cell bursting or disconnection of the transparent electrode as in the conventional example. A highly reliable color liquid crystal display element can be realized without the risk of

Embodiment 2 Next, the same applies to the second embodiment of the present invention (Fig. 1 A, B).
, C will be used for explanation. The reinforcing seal 8 is the same as that of the first embodiment up to the point where it is applied and cured in a straight line between the end face of the transparent substrate 1a having the color filter layer 2 and the organic transparent smooth layer 3 and the surface part of the opposing transparent substrate 1b. All (no change.

However, in this embodiment, the widths of the opening-shaped adhesive seals 6a and 6b, which also serve as spacers at the periphery, are changed. That is, the adhesive strength is further increased by widening the width of the adhesive seal 6b on the side without the reinforcing seal 8 compared to the width of the adhesive seal 6a on the side with the reinforcing seal 8. This increases the adhesive strength of the relatively weak adhesive seal 6b on the side without the reinforcing seal 8, making it possible to provide a color liquid crystal display element with even higher reliability than the first embodiment. Especially adhesive seal 6
This is effective when the length of b is long.

Embodiment 3 Next, a third embodiment of the present invention will be described using FIG. 2. FIG. 2 is a sectional view of a main part showing a third embodiment of the present invention. The difference is that after the organic transparent smooth layer 3 is formed on the entire color filter layer 2, the surface of the organic transparent smooth layer 3 in the area facing the adhesive seal 6b and in the peripheral area is roughened. be. The surface of the organic transparent smooth layer 3 can be roughened by mechanical roughening, oxygen plasma or alkali treatment. By roughening the surface of the organic transparent smooth layer 3, the adhesive area with the band-shaped transparent electrode 4a increases, and the adhesive strength also increases. Especially in this case, the band-shaped transparent electrode 4a
In the past, when making an electrical connection to the outside, the band-shaped transparent electrode 4a sometimes peeled off from the organic transparent smooth layer 3, but this risk is eliminated by the roughening described above.

In the embodiment, reinforcing seals were provided on all two sides in a straight line, but even partial reinforcing seals can exhibit their effects. Furthermore, although the present invention has been described as an example of a so-called simple matrix type color liquid crystal display element, it can also be applied to a so-called two-terminal type active matrix type color liquid crystal display element using MIM elements and ring diode elements.

Effects of the Invention As described above, according to the present invention, by providing this reinforcing seal, the conventional problems such as rupture of the liquid crystal cell due to peeling of the adhesive between the organic transparent smooth layer and the adhesive seal and the failure of the band-shaped transparent electrode can be avoided. There is no disconnection, and a highly reliable color liquid crystal display element can be realized.

[Brief explanation of the drawing]

1A, B, and C are plan views and sectional views of color liquid crystal display elements according to the first and second embodiments of the present invention, and FIG. 2 is a sectional view of main parts showing the third embodiment, and FIG. 3 is a cross-sectional view of a conventional color liquid crystal display element. la, lb...Transparent substrate, 2...Color filter layer, 3...Organic transparent smooth layer, 4a
, 4b... Band-shaped transparent electrode, 5a, 5b...
... Orientation IQ membrane, 6a. 6b... Adhesive seal 7... Liquid crystal, 8
...Reinforcement seal. Name of agent: Patent attorney Shigetaka Awano and one other person Shige 25!
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Claims (3)

[Claims] (1) A plurality of color filter layers are provided on the first transparent substrate of a pair of opposing transparent substrates, an organic transparent smooth layer is provided on the color filter layer, and an organic transparent smooth layer is further provided on the organic transparent smooth layer. A transparent electrode is provided, and an adhesive seal is provided on the periphery of the opposing surfaces of the pair of opposing transparent substrates to encapsulate liquid crystal, and the surface portion of the second transparent substrate protruding from the first transparent substrate and the first A color liquid crystal display device characterized in that a reinforcing seal is provided between the transparent substrate and the end face portion of the transparent substrate. (2) The color liquid crystal display element according to claim 1, characterized in that the width of the adhesive seal on the peripheral side where the reinforcing seal is not provided is widened. (3) The color liquid crystal display element according to claim 1 or 2, characterized in that the surface of the organic transparent smooth layer on the peripheral side where the reinforcing seal is not provided is roughened in the area corresponding to the adhesive seal and on the outside thereof. .