JPH0772489A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To speed up the intrusion of a sealing material into a liquid crystal injection part and to enhance the production efficiency of the element by providing the terminal part of the sealing material stuck to transparent substrates with a liquid crystal injection port and providing the part near this liquid crystal injection port with a recessed part for accepting the sealing material. CONSTITUTION:This liquid crystal display element 1 consists of two sheets of the transparent substrates 2 and transparent electrodes are formed on the surfaces of the respective transparent substrates 2e Further 7 oriented films 3 are laminated thereon. The sealing material 3 for forming the liquid crystal injection port 4 for injecting a liquid crystal material into the element is interposed between the transparent substrates 2. The part near the liquid crystal injection port 4 is provided with the recessed part 7 and a stopper 5. The sealing material is sucked into the element along with shrinkage of the liquid crystal material and arrives at the recessed part 7 and a stopper 5 when the liquid sealing material is dropped and the element is cooled down to about 0 deg.C after the liquid crystal is injected between the respective transparent substrates 2. The sealing material is then cured to seal the liquid crystal injection port 4.

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 having a light shielding film formed on the inner surface of a transparent substrate.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display element used for a display portion of automobile instruments, office equipment, clocks and the like is often a negative type display for displaying bright characters and figures on a dark background. ing. In this type of liquid crystal display element, no voltage is applied to the liquid crystal layer in the background portion other than the display portion,
The liquid crystal molecules are in a twisted state, and the light that has twisted and traveled along this is blocked by a pair of polarizing films with their polarization axes aligned in parallel, so that the light in the background is not transmitted. There is. However, when the light twists and advances in the liquid crystal layer, the degree of polarization is usually lowered, so that light of a specific color is transmitted to some extent, resulting in insufficient contrast.

To solve this problem, a method of forming a light-shielding film on the background portion other than the display portion by printing or the like is generally adopted. That is, as shown in FIGS. 3 and 4, the liquid crystal display device A has a transparent electrode (not shown) on its surface.
It is composed of one transparent substrate B, and an alignment film C is laminated on each transparent substrate B so as to cover the transparent electrodes. Transparent substrate B
On one side, the light-shielding film D is provided between the transparent electrode and the alignment film C.
Is installed. The light-shielding film D is formed on almost the entire surface of one of the transparent substrates in order to prevent the transmission of light in the background portion. More specifically, the light-shielding film D is formed in a rectangular shape such that each peripheral edge thereof is overlapped with the sealing material E provided in a strip shape on the transparent substrate B and is parallel to each peripheral edge of the transparent substrate B. There is.

[0004]

However, in this type of liquid crystal display device, the sealing material has a liquid crystal injection port F as an opening near one peripheral edge of the transparent substrate so that the liquid crystal material can be injected into the device. Although provided so as to be formed, in the above-described conventional element A, the light shielding film D is formed in a rectangular shape regardless of the shape of the liquid crystal injection port F. On the other hand, in the case of mass-producing elements, it is necessary to seal the liquid crystal injection port F after injecting the liquid crystal material. Generally, this sealing is performed by dropping a certain amount of the sealing material onto the liquid crystal injection port of each element. This is performed by curing the sealing material after a predetermined amount of the sealing material has entered the liquid crystal injection port. However, in the above-described conventional element A, the light-shielding film D is formed so as to close the liquid crystal injection port F regardless of the shape of the liquid crystal injection port F, so that the sealing material does not enter when the element is sealed. To prevent this, if a sealing material with a viscosity of, for example, 9000 cP is used before entering,
It took a long time of almost 1 hour, and the work efficiency of sealing was significantly reduced. Furthermore, since the effective opening area of the liquid crystal injection port F is narrowed by the light-shielding film D, variations occur among the elements such as uneven distribution of the sealing material entering the liquid crystal injection port F, and the liquid crystal material is sealed. Had reduced the reliability of.

Therefore, an object of the present invention is to provide a liquid crystal display device having improved reliability of sealing the liquid crystal inlet.

Another object of the present invention is to speed up the penetration of the sealing material into the liquid crystal injection port and improve the production efficiency of the device.

[0007]

To achieve the above object, according to the present invention, two transparent substrates having transparent electrodes and transparent substrates provided along each peripheral edge of the transparent substrates are attached to each other. A liquid crystal display element comprising a sealing material to be attached, a light-shielding film formed so as to cover at least one transparent electrode of a transparent substrate, and a liquid crystal material filled between the transparent substrates,
The sealing material has an end portion that terminates toward one peripheral edge of the transparent substrate, the end portion defines a liquid crystal injection port that communicates the inside and outside of the element between the transparent substrates, and the light shielding film is concave near the liquid crystal injection port. A liquid crystal display device is provided, which has a concave portion formed in the pattern of 1 and has a liquid crystal injection port sealed with a sealing material.

The sealing material seals the liquid crystal injection port so as not to come into contact with the region on the transparent substrate on which the light shielding film is formed.

A stopper having a symmetrical shape with respect to the direction substantially perpendicular to the one peripheral edge may be formed between the liquid crystal injection port between the transparent substrates and the concave portion of the light shielding film.

[0010]

When the liquid sealing material is dropped on the liquid crystal injection port of the device in which the liquid crystal material is injected and the device is cooled to, for example, about 0 ° C., the liquid crystal material shrinks and the sealing material enters the device. Get in quickly. In this case, the viscosity of the sealing material is, for example, 90
When it is about 00 cP, the required penetration is completed in about 10 minutes without the light-shielding film preventing the encapsulation material from entering the inside of the element. By forming a stopper symmetrical between the liquid crystal injection port between the transparent substrates of the element and the concave part of the light-shielding film with respect to the direction substantially perpendicular to the peripheral edge of the transparent substrate, the encapsulating material will enter the element. At this time, since the stopper acts as a guide, the intrusion can be made uniform.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a plan view of a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a main part of the device shown in FIG. The liquid crystal display element 1 of the present invention, like the conventional element,
A transparent electrode (not shown) is formed in a required shape on the surface of each transparent substrate 2, and an alignment film 3 is laminated so as to cover the transparent electrode. A sealing material 3 is provided between the transparent substrates 2 along each peripheral edge of the substrates so as to form a liquid crystal injection port 4 as an opening for injecting a liquid crystal material inside the element. A triangular stopper 5 is formed in the vicinity of the liquid crystal injection port 4 using the same material as the sealing material. On one transparent substrate 2, a light shielding film 6 is formed in a substantially rectangular shape between a transparent electrode and an alignment film 3. . This light-shielding film 6
Is formed on the transparent electrode so that its peripheral edge overlaps with the band-shaped sealing material 4, but a concave portion 7 having a concave pattern is provided near the liquid crystal injection port 4.

The liquid crystal display element 1 of the present invention having such a structure
Since the concave portion 7 is provided near the liquid crystal injection port 4 as described above, a sufficient effective opening area can be secured at the liquid crystal injection port. Therefore, when the liquid crystal injection port 4 is sealed after the liquid crystal material is injected into the device,
The sealing material 8 dropped on the top quickly enters the stopper 5 inside the liquid crystal injection port due to contraction of the liquid crystal material due to cooling of the element.

Next, a method of manufacturing the liquid crystal display element of the present invention will be described.

First, two transparent substrates 2 having a transparent electrode (not shown) made of an ITO film formed on a surface thereof by printing are prepared. To one of the transparent substrates, a sealing material 4 made of, for example, a thermosetting resin is applied by screen printing so that both transparent substrates 2 are attached to each other along each peripheral edge. The sealing material 4 is formed so as to have an end portion that terminates toward one peripheral edge of the transparent substrate 2 so that the inside and outside of the element communicate with each other. The end of this sealing material is the transparent substrate 2
When they are attached to each other, the liquid crystal injection port 4 is defined between the transparent substrates. When printing the sealing material, the stopper 5 is formed between the liquid crystal injection port between the transparent substrates of the element and the concave portion 7 of the light-shielding film 6 in a shape symmetrical with respect to a direction substantially perpendicular to one peripheral edge of the transparent substrate. . The one transparent substrate is further formed in a required pattern so as to cover the transparent electrode layer and the inner edge of the sealing material 4 and to have the concave portion 7 near the liquid crystal injection port. The light-shielding film 6 can be formed by depositing a metal such as nickel, aluminum, or chromium, but may be formed by printing using ink.

The two transparent substrates 2 thus constructed are attached to each other by heating and curing the sealing material 4 to obtain an empty element in which no liquid crystal is injected. After injecting a liquid crystal material into the element through the liquid crystal injection port 4 by a known method, the element is arranged in a desired state, and an ultraviolet (UV) curable resin as the sealing material 8 is housed inside the element. When a fixed amount is dropped on the liquid crystal injection port 4 of the device using a dispenser (not shown) and cooled to about 0 ° C., the sealing material 8 quickly enters the inside of the device as the liquid crystal material shrinks. In this case, when the viscosity of the sealing material 8 is, for example, about 9000 cP, the required penetration is completed in about 10 minutes without being blocked by the light shielding film 6 to prevent the sealing material from entering the inside of the element. After the encapsulation material is completely inserted, the encapsulation material is irradiated with ultraviolet rays and cured to obtain the liquid crystal display element of the present invention.

[0017]

As described above in detail, since the liquid crystal display element of the present invention has the above-mentioned structure, the encapsulating material can quickly enter the element without being obstructed by the light shielding film. Since the required entry is completed in an extremely short time, the productivity can be greatly improved.
Further, by forming a stopper having a symmetrical shape with respect to the longitudinal direction of the element between the liquid crystal injection port between the transparent substrates of the element and the concave portion of the light-shielding film, the stopper is provided when the sealing material enters the inside of the element. Since it acts as a guide, uneven distribution hardly occurs in the sealing material liquid crystal injection port, and uniform sealing can be achieved, and the reliability of the device can be improved.

[Brief description of drawings]

FIG. 1 is a plan view illustrating a liquid crystal display device according to an exemplary embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the liquid crystal display element of FIG. 1, taken along line II-II.

FIG. 3 is a conventional liquid crystal display device.

4 is an enlarged cross-sectional view of the waist of the liquid crystal display device of FIG. 3, taken along line IV-IV.

[Explanation of symbols]

 1. ． ． Liquid crystal display device 2. ． ． Transparent substrate 3. ． ． Alignment film 4. ． ． Sealing material 5. ． ． Stopper 6. ． ． Light-shielding film 7. ． ． Recessed portion 8. ． ． Curable adhesive

Claims (3)

[Claims] 1. Two transparent substrates having transparent electrodes, a sealing material provided along each peripheral edge of the transparent substrate for adhering the transparent substrates to each other, and at least one transparent electrode of the transparent substrates. A liquid crystal display device having a light-shielding film formed so as to cover the transparent substrate and a liquid crystal material filled between the transparent substrates, wherein the sealing material has an end portion terminating toward one peripheral edge of the transparent substrate. The end portion defines a liquid crystal injection port that communicates the inside and outside of the element between the transparent substrates, and the light shielding film has a concave portion formed in a concave pattern in the vicinity of the liquid crystal injection port, And a liquid crystal display device characterized in that the liquid crystal inlet is sealed with a sealing material. 2. The liquid crystal display element according to claim 1, wherein the sealing material seals the liquid crystal injection port so as not to come into contact with a region on the transparent substrate on which the light shielding film is formed. 3. A stopper having a symmetrical shape with respect to a direction substantially perpendicular to the one peripheral edge is formed between the liquid crystal injection port between the transparent substrates and the concave portion of the light shielding film. Liquid crystal display element.