JPS58163919A - Production of liquid crystal cell - Google Patents

Abstract

PURPOSE:To improve appearance and packaging of a liguid crystal cell by injecting a liquid crystal into the hermetic spacing between two sheets of substrates through an injection hole, and sealing the hole with a sealant to manufacture a liquid crystal cell then removing the part of the sealant built up to the outer side from the end face of the substrate. CONSTITUTION:A seal 3 which is partly notched is printed on a glass substrate 1, and the other substrate 2 is superposed and adhered thereto. The substrate is heated to cure the seal 3, and a liquid crystal 4 is injected therebetween through the notched part of the seal 3. The substrate is then heated to expand the liquid crystal thermally and to extrude part of the liquid crystal 4 from the injection port. The partly extruded part of the liquid crystal 4 is removed, whereafter a sealant 5 is coated so as to enclose the injection hole and the temp. of the cell is decreased gradually to shrink the liquid crystal thermally and to suck part of the sealant 5 into the cell. The part of the sealant 5 built up to the outer side from the end faces of the substrates 1, 2 is removed, whereby the intended liquid crystal cell is obtained.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a liquid crystal cell.

Conventionally, as shown in FIG. 1, the structure of a liquid crystal cell is that two glass substrates 1 and 2 are provided facing each other;
It is composed of a seal 3 adhered to the inner peripheral edge of the liquid crystal display 3 and a liquid crystal 4 filled in the seal 3. Generally, this liquid crystal cell is created by printing a seal 3 with a part cut out on one glass substrate 1, stacking the other substrate 2 and hardening the seal 3 by heating. Liquid crystal 4 was injected, and after the injection, the notch of the seal 3 was sealed with a stinging agent 5.

The reliability of the sealing degree of this cell structure largely depends on the size of the contact area between the seal 3 and the sealant 5 and between the glass substrates 1 and 2 and the sealant 5. In other words, if the contact area is large, there is less risk of moisture entering from outside the cell, whereas if the contact area is small, some external conditions or deterioration of the seal 5 over time may cause the inside of the cell to enter through the small gap. There is a risk that moisture etc. may get mixed in.

In view of this point, attempts have been made in the past to increase the above-mentioned contact area as much as possible. For example, JP-A-55-127
As shown in Publication No. 517, before sealing the cell filled with liquid crystal, the liquid crystal is heated once to cause thermal expansion and a part of the liquid crystal is extruded from the injection hole, and then the extruded part of the liquid crystal is removed. Then, apply a sealant to cover the injection hole. If the temperature of the cell is then gradually lowered, the liquid crystal will shrink due to heat, and a portion of the sealant will be sucked into the cell. The cell thus prepared is shown in FIG. 2. As shown in FIG. 2, the sealing agent 5 enters relatively deep into the injection hole, so that the above-mentioned contact area can be increased. As the sealant 5, resin is usually used.

However, in such a conventional method, the resin 5 is removed with parts of the sealing resin 5 protruding from the end surfaces of the glass substrates 1 and 2 remaining.
Since the sealing resin 5 had hardened, the protrusion of the sealing resin 5 was conspicuous and undesirable in appearance, and the presence of the protruding portion of the sealing resin 5 from the end surfaces of the glass substrates 1 and 2 was inconvenient in terms of mounting. Ta.

The present invention has been made to solve the above conventional problems, and aims to improve the appearance and mounting by removing the protrusion of the sealant 5 from the end surface of the substrate.

Hereinafter, one embodiment of the present invention will be described in detail.

FIG. 3 is a plan view after completion of an embodiment of a cell manufactured using the method for manufacturing a liquid crystal cell according to the present invention. The manufacturing process up to sealing the injection hole with the sealing resin 5 is the same as the conventional manufacturing method described above (Japanese Unexamined Patent Publication No. 55-127517).

The present invention is characterized in that the portion of the sealing resin 5 that bulges out from the end surface of the glass substrate is removed. At first glance, FIG. 3, which shows the cell after this removal process, gives the impression that the reliability in terms of sealing has deteriorated compared to the conventionally structured cell shown in FIG. 2, but in reality, the reliability has not changed compared to the conventionally structured cell.

The reason for this is as follows. The present inventor has confirmed that in the conventional cell structure shown in FIG. 2, the portion of the sealing resin 5 that bulges out from the end surfaces of the glass substrates 1 and 2 does not substantially improve the reliability regarding the degree of sealing. That is, glass substrates 1 and 2
Strictly speaking, the seal 3 adhered to the inner periphery of the glass substrates 1 and 2 does not extend to the periphery ends of the glass substrates 1 and 2, and therefore a minute gap exists at the end of the inner periphery of the glass substrates 1 and 2.

That is, since the sealing resin 5 and the outside air come into contact with each other in this minute gap, the resin portion located outside the contact area cannot contribute much to improving reliability. Therefore, the third
The liquid crystal cell shown in the figure has the same reliability of sealing as a cell with a conventional structure, and has achieved technical progress in that a part of the sealing resin 5 has been cut to improve the cell shape.

In the above embodiment, a part (the raised part) of the sealing resin 5 was cut after curing, but the liquid crystal display was removed by adjusting the amount of the sealing resin 5 before curing and gradually lowering the temperature of the cell described above. The sealing resin 5 may be applied in an amount that does not cause the sealing resin 5 to protrude beyond the end surfaces of the glass substrates 1 and 2 when the sealing resin 5 is drawn into the cell due to the thermal contraction of the glass substrates 1 and 2.

FIG. 4 is a partial plan view of a completed cell according to another embodiment of the present invention. As shown in the figure, a notch formed in a part of the seal 3 is provided with a recess connected to the liquid crystal injection path on both sides of the liquid crystal injection path. This depression is filled with sealing resin 5, which increases the contact area between the seal 3 and the sealing resin 5, thereby improving reliability.

Of course, the raised portion or portion of the sealing resin 5 outside the end surface of the substrate is removed by the same procedure as when forming the cell shown in FIG. 3.

According to the present invention described above, a part of the sealing resin is removed while the reliability regarding the degree of sealing is comparable to that of the conventional method, and improvements are obtained in terms of appearance and mounting.

[Brief explanation of drawings]

1 and 2 are plan views of a conventional liquid crystal cell, FIG. 3 is a plan view of one embodiment of a liquid crystal cell according to the present invention, and FIG. 4 is a partial plan view of another embodiment. In the figure, 1, 2: Glass substrate, 3: Seal, 4: Liquid crystal, 5
: Sealing resin,

Claims (1)

[Claims] 1. Injecting liquid crystal into a sealed gap formed between two substrates through an injection hole; sealing the injection hole with a sealant; A method for manufacturing a liquid crystal cell, comprising a step of removing an outwardly raised portion.