JPS6197623A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE:To inject a liquid crystal compsn. in a short period into a cell without requiring many stages by providing an open position to part of a display panel and dispersing spacers between both substrates then filling the liquid crystal compsn. into the cell and reducing the pressure to maintain the prescribed thickness of the liquid crystal layer. CONSTITUTION:Oriented films 14, 15 are formed to each of a pair of plastic substrates 12, 13 provided with electrodes 10, 11 and the substrates are mated in such a manner that the electrode sides face each other. The peripheral part is sealed in a manner that an injection port 16 for the liquid crystal compsn. remains to constitute the bag-shaped cell. The liquid crystal compsn. 17 mixed with the prescribed spacers 8 so as t maintain the specified spacing in the bag is filled into the bag-shaped cell by a syringe, etc. and thereafter the pres sure in the cell is reduced by using a vacuum packaging machine until the liquid crystal layer has 7mum thickness. The port 16 is sealed by thermocom pression bonding after the excess liquid crystal compsn. is removed. The direct contact of the liquid crystal with the sealant is thus obviated. The reliability is improved and a liquid crystal container for the purpose of injecting the liquid crystal is made unnecessary, by which working efficiency is improved.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a 14-channel liquid crystal display.

(Structure of conventional example and its problems) As shown in FIG. 1, a conventional liquid crystal display panel has a transparent electrode l on at least one side. Alignment films 5 and 6 are formed on the electrodes 1 and 3 of the substrate 2 and the substrate 4 with electrodes 3, and a sealing material 7 mixed with a spacer is applied to the periphery of the alignment films and bonded together to form a cell. After placing the cell in a vacuum device and sufficiently reducing the pressure from the outside of the cell through the injection port to the inside of the cell, the injection port is immersed in the liquid crystal composition, and while the inside of the vacuum device is returned to atmospheric pressure, the liquid crystal composition is poured into the cell. The method used was to inject water and seal the injection port. However, in order to inject the liquid crystal composition without leaving any air bubbles inside the cell, the pressure of K must be sufficiently reduced to the inside of the cell. For this reason, the process of injecting the liquid crystal composition took a lot of time.

On the other hand, when the area of the cell becomes large, not only is it time consuming, but there is also the problem that the gap between the center and the periphery of the cell becomes non-uniform. Particularly when the substrates are plastic films, the upper and lower plastic substrates are in close contact with each other, making it extremely difficult to inject the liquid crystal composition.

Furthermore, as shown in Fig. 2, even in the case of the T4 channel, which has a structure in which a step of dispersing spacers 8 over the entire surface of the substrate is added between the step of applying the sealant 7 and the step of laminating the sheets, the number of steps is reduced. Not only does this increase the number of spacers, but it also requires large-scale equipment to uniformly disperse the spacers, resulting in a significant increase in cost. Further, after dispersing the spacers, until the two substrates are bonded together, dust tends to get mixed in, and great care is required to prevent the spacers from moving and becoming lopsided, resulting in a reduction in work efficiency.

(Objective of the Invention) The object of the present invention is to eliminate the drawbacks of the conventional art and provide an excellent liquid crystal display with high quality and high yield using a new liquid crystal injection method that can inject a liquid crystal composition with a simple configuration. / J' flannel.

(Structure of the Invention) The liquid crystal display panel of the present invention is a liquid crystal display panel in which a pair of electrode-attached plastic film substrates, at least one of which is transparent, are sealed so that the respective electrode surfaces face each other. An open area is provided in the cell, a liquid crystal composition is poured in, the liquid crystal layer is made to a predetermined thickness, and the open area is then sealed. A liquid crystal composition can be injected into the liquid crystal composition.

(Explanation of Examples) An embodiment of the present invention will be described based on FIG.

As shown in the figure, an alignment film 14.1 is provided on each of the plastic film substrates 12.13 with a pair of electrodes to and xt.
5 are formed, and the electrode surfaces face each other, and the periphery is sealed leaving an injection port 16 for the liquid crystal composition to form a bag-like cell. Next, the liquid crystal composition 17 mixed with a predetermined (for example, 7 μm) spacer so as to maintain a constant gap inside the bag is put into the bag-shaped cell using a syringe or the like, and then a liquid crystal layer with a thickness of 7 μm is placed using a vacuum packaging machine. After the pressure is reduced to a thickness of , and excess liquid crystal composition is removed, the injection port 16 is sealed by thermocompression bonding. In this way, the gap can be maintained within 7.0±0.2 μm without the need for a spacer dispersion process. In addition, the liquid crystal does not come into direct contact with the sealing material, making it highly reliable.
This eliminates the need for high-vacuum equipment to create a sufficient vacuum state inside the panel, as well as the necessary jigs and tools, such as mechanical parts to move the liquid crystal cell up and down, which greatly reduces the time required to produce panels and increases work efficiency. can be significantly improved.

After forming the bag-like cells, a spacer of a predetermined size (for example, 7 μm) is blown into the bag-like cells to disperse the liquid crystal composition, and a liquid crystal composition is put into the bag-like cells using a syringe or the like, and a weight is used to uniformly distribute the liquid crystal until the thickness of the liquid crystal reaches 7 μm. Even with the method of applying a load and sealing the injection port 16 with adhesive, there is no need for large-scale equipment for uniformly distributing the spacers as in the past, and there is no need to worry about contamination with dust. Therefore, it is possible to prevent a decrease in work efficiency, and as in the above embodiment, the gear, f
This results in a significant cost reduction due to the uniformity of the liquid crystal and the need for no equipment or jigs during liquid crystal injection.

(Effects of the Invention) According to the present invention, a large-scale spacer dispersion device for making the panel gap uniform, equipment such as a high vacuum device, and the necessary jigs and tools are not required, so the cost can be significantly reduced. Can be done. Even when using a plastic film substrate, the liquid crystal composition can be easily injected in a short time without going through many steps as in the conventional method.

Furthermore, defects such as air bubbles remaining in the cells and deterioration of appearance due to non-uniform gaps due to insufficient or excessive vacuum reduction are eliminated, and this is highly effective in improving quality, yield, and reliability.

[Brief explanation of drawings]

Figures 1 (a) and (b) are a plan view and a cross-sectional view of a conventional liquid crystal display panel, Figure 2 is a cross-sectional view of a conventional liquid crystal display panel in which spacers are dispersed, and Figures 3 (a) and (b). 1 is a plan view and a sectional view of a liquid crystal display panel according to an embodiment of the present invention. 1...Transparent electrode, 2,4...Substrate, 3,10.11
...electrode, 5,6,14.15...alignment film, 7...
・Sealing material, 8...Spacer, 12.13...Plasti, film board, 16...Injection port, 17...
liquid crystal composition. Figure 1 (a) Figure 2

Claims (6)

[Claims] (1) A pair of plastic film substrates with electrodes, at least one of which has a transparent electrode, are sealed so that the electrode surfaces thereof face each other. An open part is provided in a part of the sealed liquid crystal display panel, and a liquid crystal composition is placed in the liquid crystal layer. A liquid crystal display panel characterized in that an open area is sealed after the thickness has been set to a predetermined value. (2) The liquid crystal display panel according to claim (1), wherein the liquid crystal composition is introduced after spacers are dispersed between both substrates. (3) The liquid crystal display panel according to claim (1), wherein the liquid crystal layer is made to have a predetermined thickness by reducing the pressure after putting the spacer and the liquid crystal composition therein. (4) The liquid crystal display panel according to claim (1), wherein the liquid crystal layer is made to have a predetermined thickness by applying pressure after putting the spacer and the liquid crystal composition therein. (5) The liquid crystal display panel according to claim (1), characterized in that after the spacer and the liquid crystal composition are put in, the liquid crystal layer is made to a predetermined thickness and the opening is sealed by thermocompression bonding. (6) The liquid crystal display panel according to claim (1), wherein the liquid crystal layer is formed to a predetermined thickness and the opening is sealed with an adhesive material after the spacer and the liquid crystal composition are placed therein.