JP2001183680A - Liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal device which can solve the problem that a sealing stage after liquid crystal injection brings about deformation of liquid crystal substrates at the time of hardening of a sealant and causes unevenness of a gap between two substrates because the sealant has generally hardening and contracting properties, the problem that this unevenness of the gap and a stress to substrates cause degradation in quality of liquid crystal characteristics represented by the picture quality, and the problem that the effective active area of liquid crystal is reduced because of the existence of a guard island which is conventionally provided in the vicinity of a liquid crystal injection port in order to exclude these causes. SOLUTION: The guard island is arranged in a liquid crystal material injection port constituted by projection integrally formed with a sealing frame, and the front end of the guard island is extended to the same position as the front ends of projections, and preferably, both front ends are extended up to the outer peripheral part of a substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing portion for sealing a liquid crystal after injecting a liquid crystal in manufacturing a liquid crystal device.

[0002]

2. Description of the Related Art A liquid crystal device in which a liquid crystal is sandwiched between two electrode substrates has a simple structure, so that the display device of a television, a personal computer, an input device of a touch panel, an optical shutter device, etc. Used in a wide range of fields. The liquid crystal in this liquid crystal device is loaded between two substrates which are kept at a narrow interval. This gap needs to be managed on the order of several microns, and is delicately susceptible to the effects of sealing after liquid crystal injection, and improvements have been made for that.

[0003] An example of the structure of a sealing portion of a liquid crystal device is disclosed in Japanese Patent Application Laid-Open No. 10-153787.
FIG. 7 is a plan view showing a conventional liquid crystal device as an example of a display device having a sealing portion equivalent thereto, and FIG.
It is AA sectional drawing of. In the liquid crystal device, two projections 3 are formed in an opening in a space 6 in which transparent substrates 1 and 2 each having a transparent electrode disposed inside as shown by a dotted line in FIG.
The liquid crystal material is injected from the injection port formed in step 1, and after the liquid crystal material is injected, the sealing material is loaded and sealed. Although it depends on the size and application of the liquid crystal device,
The thickness of the transparent electrode is usually several 0.1 microns or more, while the gap between the two substrates is about 5 microns. In the cross-sectional view of FIG. 8, the relative gap is shown large for convenience of explanation. Since the seal is a lid for preventing the injected liquid crystal substance from flowing out, it is not desirable to mix the liquid crystal substance with the liquid crystal substance and enter the device. Elements 41 and 42 constitute the guard island 4, and by arranging the guard island near the injection port, the sealing material is prevented from being mixed into the liquid crystal. The guard island 42 plays the main role. In addition, a UV (ultraviolet) curable material is generally used for the sealing material, and the substrate shrinks while being adhered with a strong force during curing. Glass is often used for the transparent substrate, but the shrinkage of the sealing material causes the transparent substrate near the injection port to be deformed. As a result, the gap of the liquid crystal device becomes uneven, and the screen quality is greatly hindered, for example, color unevenness occurs. In the embodiment disclosed in Japanese Patent Application Laid-Open No. H10-153787, a projection 41 is provided on the sealing side of the guard island for the purpose of reducing this effect.

Several guard islands have been proposed in addition to the above publication. For example, JP-A-2-553
No. 33 is one of them. In any case, at least a part of the guard island is located further inside than the inside of the sealing frame, so that the operation area of the liquid crystal is narrowed. Originally, we would like to use the entire sealing frame as the active area of liquid crystal, that is, the area for displaying images.
Due to the presence of the guard island, the area becomes narrower by the extent that the guard island enters the inside of the sealing frame. In FIG. 7, the range serving as the active area is indicated by a two-dot chain line B. On the guard island side, a dead area occurs between the guard island and the sealing frame,
It can be seen that the actual active area has become narrower.

[0005]

The liquid crystal is slightly affected by the gap. Partial gap unevenness is the most desired requirement. In particular, when it is used for a display device, it must be avoided because it also determines the image quality. Since the sealing of the liquid crystal injection port is easily affected,
You must be especially careful. JP-A-10-153
No. 787 has the same purpose, but it has been found that the content disclosed therein does not sufficiently fulfill the purpose. That is, the guard island 41 in the conventional embodiment is located in the injection port to cover the rigidity of the opening of the sealing frame. Certainly, the deformation of the liquid crystal device is smaller and the display quality is improved as compared with the case where there is no liquid crystal device. That is, at the time of sealing, the sealing material contracts with a strong force, so that the transparent substrates 1 and 2 strongly adhered to the two sealing materials are pulled by a strong force in the direction of arrow C in FIG. The guard island is in the form of a fulcrum of a lever, and a force is exerted on the active area containing the liquid crystal to spread in the direction of arrow D, causing a partial gap unevenness while applying a strong stress to the substrate. In other words, if there is a portion on the outside of the guard island where a large amount of sealing material is loaded, the influence of the sealing island causes gap unevenness. If gap unevenness occurs, it may appear as display unevenness and brightness unevenness, and may have a problem of deteriorating display quality. A first problem is to prevent the gap unevenness from occurring with a simple structure.

In a liquid crystal device, since the liquid crystal portion operates to fulfill the purpose of the device, it is desirable that the active area in which the liquid crystal operates can be made wider. Desirably, all of the inside of the liquid crystal sealing frame can be used. In the conventional embodiment, since the guard island is arranged inside the sealing frame, that part does not become a liquid crystal area, and the active area is reduced accordingly. A second object of the present invention is to increase the active area of the liquid crystal.

[0007]

In order to solve the above-mentioned problems, the present invention comprises a sealing frame and a guard island which are sandwiched between two opposing substrates and have a liquid crystal injection port composed of two projections for injecting liquid crystal. In the liquid crystal device, the tip of the guard island is located near the tip of the projection.

[0008] More preferably, the tip of the guard island and the tip of the projection of the liquid crystal injection port extend to the outer periphery of the substrate.

Further, the rear end of the guard island is located outside the inner periphery of the sealing frame.

Further, the tip of the guard island is thinner than the trunk.

Further, the guard island has a substantially barrel shape.

Further, the guard island includes a first guard island having a longitudinal shape in a direction along the two projections and a guard island 2 having a longitudinal shape in a direction perpendicular to the first guard island. Features.

[0013] The first guard island and the second guard island are arranged in a substantially T shape.

[0014]

Embodiments of the present invention will be described below based on embodiments with reference to the drawings. FIG. 1 is a plan view showing a first embodiment of the present invention. Since the basic configuration of the liquid crystal device is the same as that shown in the conventional example, the same numbers are given to the respective elements. That is, 1 and 2 are transparent substrates, 3 is a sealing frame, 31 is a projection forming an injection port, 4 is a guard island composed of two elements, and 5 is a sealing material for sealing the injected liquid crystal substance. is there. The difference from the conventional example shown in FIG. 7 lies in the arrangement of guard islands. The sealing portion, which is a main part of the present invention, is indicated by area E. FIG. 2 is an enlarged view of a key point in which the sealing portion (E) of FIG. 1 is enlarged, and FIG. 3 is a cross-sectional view of a guard island portion of FIG. 2 corresponding to the line AA of FIG. In the present embodiment, the distal end of the first guard island 41 having a longitudinal direction along the two projections 31 extends to substantially the same position as the distal end of the projection 31. Also, the first
Having a longitudinal direction orthogonal to the guard island
The rear end of Guard Island 42 is in the inlet,
It is positioned so as not to protrude inside the sealing frame. That is, the entire guard island is located in the inlet.

At the time of sealing after injection of the liquid crystal substance, the sealing material 5 is stopped near the second guard island.
The sealing material 5 is prevented from flowing into the active area of the liquid crystal. Since the position of the second guard island can be restricted to the outer peripheral side of the liquid crystal device as compared with the conventional position, the force for pulling the two substrates 1 and 2 when the sealing material 5 is cured and compressed can also be limited. Also, the tip 4 of the first guard island
Since the distal end of the projection 1 is located at the same level as the distal end of the projection 31, the rigidity of the missing portion of the sealing frame opened as the injection port is covered together with the two projections. Referring to FIG. 3, when the suction force C of the substrate due to the hardening and compression of the sealing material is restricted by the second guard land than before, and the rigidity increases due to the extension of the first guard island. At the same time, the deformation outside the guard island is also limited, so that the force for spreading the active area in the direction D with the guard island as a fulcrum is also reduced. As a result, the deformation of the active area does not occur as in the prior art, so that the operation of the liquid crystal is stabilized and the display quality is further improved. As a matter of course, the second guard island has an effect of preventing the sealing material 5 from entering the active area and preventing dust from entering the active area.

FIG. 4 is a second embodiment of the present invention having a greater effect, and is an enlarged view of a main part similar to FIG. FIG. 5 is a sectional view of FIG. 4 showing the same position as FIG. In FIG. 4, the two projections 31 and the tip of the first guard island 41 extend to the outer periphery of the liquid crystal device. As is clear from comparison with FIG. 3 in FIG. 5 showing a cross section, in this embodiment, the projection 31 of the injection port and the guard island 41 act as a pier and receive all the hardening / compression force of the sealing material 5. Therefore, the influence on the active area can be almost eliminated. Therefore,
A higher quality liquid crystal device can be provided.

By arranging the guard island in the injection port as described above, the entire inner circumference of the inside of the sealing frame 3 is used as the active area so that the active area B 'of the liquid crystal device is shown as shown in FIG. As a result, more free design is possible, and the second problem can be solved.

FIG. 6 is an enlarged view of a main point showing a third embodiment of the present invention. In the present embodiment, the guard island 43 has a barrel shape. It has been confirmed that if the viscosity of the sealing material and the distance between the projection 31 and the guard island 43 are appropriately set, the inflow of the sealing material can be suppressed even without the second guard island described in the first embodiment. . At that time, it is effective to make the tip shape narrower than the trunk portion (also to make the trunk portion thicker) in order to load the sealing material to a predetermined range. This shape is also useful for securing a reliable sealing area while suppressing deformation to the active area. Specifically, this is achieved by rounding the tip. This shape makes the flow of the sealing material smooth, which is effective for ease of loading, stability, and reliability of sealing. Also in this case, it is more desirable that the protrusion and the tip of the guard island extend to the outer periphery of the liquid crystal device.

The process of actually manufacturing a liquid crystal device can be summarized as follows.
Similarly, a plurality of sealing frames and guard islands are printed on one of two upper and lower large substrates on which electrodes corresponding to a plurality of liquid crystal cells are arranged, and this is printed on the two upper and lower substrates. A predetermined gap is provided in a sandwiched manner to form a space filled with liquid crystal, and the two large substrates are bonded and fixed using the thermosetting property of the sealing frame material. This is a so-called multi-piece batch process. Next, it is scribed to each liquid crystal cell, and then a liquid crystal substance is injected and sealed with a sealing material. That is, the positional relationship between the injection port portion and the outer periphery is determined by the scribe. The significance of the fact that the tip of the injection port projection and the tip of the guard island are scribed and extended to the outer periphery of the substrate is as described above. The patterning is performed so that the pattern overlaps, and cut off at the scribe stage. The problem is that it is not easy to scribe a portion having a sealing frame or the like at the scribe stage. If possible, it is desirable to remove it from the cut.
Normal scribing only needs to cut the substrate material portion (glass), but cutting the portion fixed by the sealing frame is difficult to cut and causes cracking and chipping. If the tip of the projection that forms the injection port, which is a part of the sealing frame as well as the guard island, is thinned, it can be easily scribed by patterning so that the thin part is selected as the scribe line. It will be easier. Thus, narrowing the tip is also useful in manufacturing for realizing the present invention.

[0020]

As described above, according to the present invention, when the liquid crystal material is injected into the liquid crystal device and the injection port is sealed with a sealing material, the tip of the guard island is formed by the tip of the projection forming the injection port. By disposing these tips at almost the same position as the part, preferably by extending these tips to the outer periphery of the substrate, the effect of substrate deformation due to the hardening and compression of the sealing material is reduced, and stable quality liquid crystal with little gap unevenness The device can be provided.

Further, by arranging the guard island in the injection port constituted by the projection and arranging the rear end of the guard island outside the inner periphery of the sealing frame, the sealing material is hardened and compressed. It is possible to provide a liquid crystal device in which the influence of substrate deformation is further reduced and stable quality is provided and the active area of the liquid crystal is widened.

Further, by making the tip shape of the guard island narrower than the body, the loading of the sealing material is facilitated, and the protrusion of the injection port and the guard island are extended to the outer periphery of the liquid crystal device. In this case, the manufacturing of the liquid crystal device is facilitated.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment according to the present invention.

FIG. 2 is an enlarged view of a main part showing a part B of FIG. 1 which is a main part of the present invention.

FIG. 3 is a sectional view of FIG. 2 showing a section of an inlet;

FIG. 4 is an enlarged view of a main part showing a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of FIG. 4 showing a cut surface of the injection port.

FIG. 6 is an enlarged partial view of a main part in another embodiment of the present invention, in which a guard island has a barrel shape as an example.

FIG. 7 is a plan view showing a conventional embodiment according to the present invention.

FIG. 8 is a sectional view taken along line AA of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 2 Transparent substrate 3 Sealing frame 31 Projection integral with the sealing frame to form an injection port 4 Guard island 41 First guard eye line 42 Second guard eye line 43 Barrel-shaped guard island 5 Sealing material 6 LCD loading space

Claims (7)

[Claims] 1. A liquid crystal device having a sealing frame and a guard island having a liquid crystal injection port composed of two projections for injecting liquid crystal sandwiched between two opposing substrates, and a tip of the guard island is formed of the projection. A liquid crystal device, which is located near the tip. 2. The liquid crystal device according to claim 1, wherein the tip of the guard island and the tip of the projection extend to the outer periphery of the substrate. 3. The guard island according to claim 1, wherein a rear end of the guard island is located outside an inner periphery of the sealing frame.
Or the liquid crystal device according to claim 2. 4. The liquid crystal device according to claim 1, wherein a tip portion of the guard island is thinner than a body portion. 5. The liquid crystal device according to claim 1, wherein the guard island has a substantially barrel shape. 6. A first guard island having a longitudinal shape in a direction along the two projections of the liquid crystal device, and a second guard island having a longitudinal shape in a direction perpendicular to the first guard island. The liquid crystal device according to claim 1, comprising a guard island. 7. The liquid crystal device according to claim 5, wherein the first guard island and the second guard island are arranged in a substantially T shape.