JPS59226324A - Method for sticking polarizing plate to liquid crystal panel - Google Patents

Abstract

PURPOSE:To improve the display quality and the reliability and improve the yield by putting a liquid crystal panel into a pressurizing vessel while heating at a temp. in a specific temperature range after a polarizing plate is stuck to the liquid crystal panel and applying a pressure to the panel with air to remove easily minute air bubbles which are generated at the sticking time. CONSTITUTION:For the purpose of removing minute air bubbles 5 which are generated by inevitable surface rugged parts 1b and 2c on production of a polarizing plate 2 and a liquid crystal panel substrate when the polarizing plate 2 is stuck to the substrate, panels 8 having air bubbles are arranged and attached to a holder and are put longitudinally in an air pressurizing vessel 6 immediately after being heated by a drier. Heated air 7 is press-charged to apply 1-6kg/cm<2> pressure at 70-100 deg.C. The heating time is made the shorter if the temperature in the higher. For example, air bubbles are removed with 1kg/cm<2> pressure at 70 deg.C for >=10min or with 6kg/cm<2> pressure at 100 deg.C for about 2min. Thus, a difference due to the shape, the size, or the like of the panel is not generated, and air bubbles are removed completely without restricting setting of sticking conditions even if various kinds of products are manufactured in a small quantity with the same polarizing plate sticking machine, and air bubbles are hot generated in products thereafter.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for attaching a polarizing plate to a liquid crystal panel with a polarizing plate used as a display element in various fields such as consumer use and industrial use.

Structure of conventional example and its problems Conventionally, the method of pasting a polarizing plate on a liquid crystal panel C. In clean air, as shown in FIG. Place the polarizing plate 20 on the vacuum suction holder 3 with the adhesive side of the polarizing plate facing the liquid crystal panel 1.
Pressure is applied to one end surface 2a while rotating the rubber roller 4, and the other end surface 1 of the polarizing plate is sequentially attached to the polarizing plate 2 and the liquid crystal pile surface 1a.
It is pasted by pressing it together.

At this time, in order to paste between the liquid crystal panel surface 1a and the polarizing plate 2 without introducing air bubbles that impair display quality, the hardness of the roller 4 and the
Pressure force, application speed, uniformity of pressure, etc. are important factors, but it is very complicated to mass produce a wide variety of products in small quantities using the same application machine.

Also, even if these conditions are determined, as shown in Figure 2,
Since the polarizing plate 2 is subjected to a tensile force in one direction during its manufacturing process, the surface has wavy unevenness 2c, and the unevenness is uneven depending on the location.

Furthermore, the liquid crystal panel surface 1a also has unevenness on the glass surface 1b used for it, and due to these factors during mass production, even if careful attention is paid to the polarizing plate pasting work and management, the polarizing plate 2 and the liquid crystal panel Between surface 1a and V? -1 The number of air bubbles 5 that are introduced is several percent. Therefore, if bubbles occur, remove the polarizing plate with a knife, remove the adhesive glue with a bath salt, clean the surface, and then reapply it. This recycling work involves a lot of material and man-hour loss, and there are many problems such as the danger of handling cutlery and easily broken glass. In addition, from a reliability standpoint, even if air bubbles are not introduced into the highly uneven areas of the polarizing plate or glass after pasting and the adhesive strength between the polarizing plate and the glass surface is not improved, the polarizing plate will not last long. Second, there is the problem of bubbles forming over time.

Purpose of the Invention The present invention eliminates such conventional drawbacks, and makes it possible to easily remove air bubbles that occur due to the unevenness of the glass surface of a general polarizing plate, regardless of the size of the panel. The present invention provides a method for attaching a polarizing plate to a liquid crystal panel.

Structure of the Invention The present invention requires 70 to 100 seconds to attach a polarizing plate to a liquid crystal panel.
1 to 6 K with a fluid such as air in a heated state of °C
This is to remove air bubbles generated by pressurizing at a pressure of P/cA. Air bubbles can be removed by taking time to maintain adhesiveness in the above state, and after that, the adhesion between the polarizing plate and the liquid crystal panel surface improves due to the force field that creates the gap, so there is no air bubble generation and it is possible to regenerate. This eliminates the time and effort required to create a highly reliable liquid crystal panel.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below. A polarizing plate is pasted on the liquid crystal panel by the usual method, the liquid crystal panel with bubbles is placed in a holder, heated in a dryer, and then immediately placed in an air pressure container 6 as shown in Fig. 3 and heated. Air pressure was applied by introducing Air 7. In FIG. 3, reference numeral 8 denotes liquid crystal panels with polarizing plates arranged by holders.

The percentage of bubble-remaining liquid crystal panels (residual rate) of the bubble-generated liquid crystal panels attached in this manner was as shown in FIG. 4. From this result, it can be seen that heating and pressurizing at 1 KJ'/cA to 7o°C or higher is sufficient. Father, the higher the temperature, the shorter the charging time should be, 1 yen/++ 70°C
For about 10 minutes or more at 60°C, 71i, and about 2 minutes at 100°C, it is sufficiently effective. Further, the same effect can be obtained by heating the liquid crystal panel in advance and then putting it into a pressurizing container, or by putting it into a pressurizing container and applying pressure.

Effects of the Invention As described in 2, according to the present invention, it is possible to easily remove minute air bubbles that occur in the polarizing plate pasting machine due to surface irregularities that cannot be avoided during the manufacture of polarizing plates and glass, thereby improving display quality. This is an extremely advantageous method in practice, as it greatly contributes to improving yield, improving reliability, and improving workability. In addition, this method does not differ depending on the shape or size of the panel, and even when producing a wide variety of products in small quantities using the same polarizing plate pasting machine, there is no need to strictly control the setting of conditions, making the work easy, and its practical effects are extremely high. expensive.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a polarizing plate pasting method using a roller method, Fig. 2 is a cross-sectional view of an example showing the state of bubbles generated when pasting is performed using a roller method, and Fig. 3 is an example of an embodiment of the present invention. FIG. 4 is a cross-sectional view of the device shown, and is a graph showing an effect of implementing the present invention. 1. LCD panel panel 2. Polarizing plate, 3. Vacuum suction holder, 4. Rubber roller, 5. Air bubble 6.
... Air pressurized container, 7 - Heating air, 8...
...Liquid crystal panel with polarizing plate. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
figure? W Figure 4 Natural humidity C)

Claims (1)

[Claims] A method for attaching a polarizing plate to a liquid crystal panel, which includes the steps of: after attaching a polarizing plate to a liquid crystal panel, heating the panel at 70 to 100°C and applying pressure of 1 to 6 b/cA.