JPH07294902A - Sticking device of film for liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide the polarizing prate sticking device which doesn't internally distort a polarizing plate and doesn't unevenly press it and has a simple structure. CONSTITUTION:A polarizing plate 1 having a paste face 14 is stuck to a liquid crystal cell 3. A polarizing plate support body 2 has a curved face, whose side facing the polarizing plate 1 is convex, to support the polarizing plate 1, and the polarizing plate 1 which is temporarily fixed along the curved face with the paste face 14 on the outside is brought into contact with the liquid crystal cell 3 so that the edge part of the polarizing plate 1 coincides with that of the liquid crystal cell 3, and the polarizing plate support body 2 sticks the polarizing plate along the liquid crystal cell 3 while rotating and pressing it in accordance with going of the liquid crystal cell 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film sticking device for a liquid crystal display device, which sticks a film having an adhesive layer such as a polarizing plate on a substrate such as a liquid crystal cell.

[0002]

2. Description of the Related Art Generally, a liquid crystal display device includes a liquid crystal cell in which liquid crystal is filled between a pair of substrates having transparent electrodes for display, and a polymer film arranged on at least one surface of the liquid crystal cell. And a polarizing plate consisting of. Therefore, in the manufacturing process of the liquid crystal display element, the work of attaching the polarizing film to the liquid crystal cell is performed.

A conventional method for attaching a polarizing plate to a liquid crystal cell is called a pressure roller method. In this pressure roller method, a polarizing plate placed on the surface of the liquid crystal cell is added. By rotating the pressure roller while rotating in a pressed state, the polarizing plate is attached to the liquid crystal cell so that air bubbles do not enter between the polarizing plate and the liquid crystal cell.

A specific example of the method of sticking a polarizing plate by the above pressure roller method will be described with reference to FIGS. 4 and 5.

First, as shown in FIG. 4, a polarizing plate support 5
1. A polarizing plate 52 having a glue surface on the surface of 1 is a polarizing plate support 5
It is placed along a guide (not shown) provided on the No. 1. At this time, the left end of the polarizing plate 52 is protruded by about 20 mm from the polarizing plate support 51.

Since a cavity is formed inside the polarizing plate support 51 and a plurality of holes are formed on the surface, the polarizing plate 52 is sucked through the holes using a vacuum pump (not shown). Thus, the polarizing plate 52 is temporarily fixed. Next, the liquid crystal cell 53 is placed along the guide provided on the liquid crystal cell support 54. The liquid crystal cell 53 is fixed to the liquid crystal cell support 54 by the same method as in the case of the polarizing plate 52.

Next, as shown in FIG. 5 (a), after the adhesive surface laminator of the polarizing plate 52 is peeled off, the polarizing plate support 51 is formed.
Is reversed by a motor (not shown) to maintain the inclined state, and the adhesive surface of the polarizing plate 52 is opposed to the liquid crystal cell 53.

Next, as shown in FIG. 5 (b), the liquid crystal cell support 54 is slid by motor drive (in the figure, it is slid to the right side), and the polarizing plate support 51 is formed.
Below. Next, air is introduced into a pressing chamber arranged on a column (not shown) of the polarizing plate pasting roller 55 to descend the polarizing plate pasting roller 55, and one end of the polarizing plate 52 is brought into contact with one end of the liquid crystal cell 53. At this time, in the contact portion between the polarizing plate 52 and the liquid crystal cell 53, the polarizing plate 5
The slide amount of the liquid crystal cell support 54 is adjusted so that the edge part protruding from the second polarizing plate support 51 and the edge part of the liquid crystal cell 53 corresponding to the edge part coincide with each other.

Next, as shown in FIG. 5 (c), the polarizing plate attaching roller 55 is pressed against the polarizing plate 52, and the liquid crystal cell support 54 is slid to the right side. It is peeled off along the body 51 and attached to the liquid crystal cell 53. Thereafter, as shown in FIG. 5D, the polarizing plate sticking roller 55 is separated from the polarizing plate 52, and the sticking of the polarizing plate 52 to the liquid crystal cell 53 is completed.

By the way, in the above pressure roller method, since the polarizing plate 52 is pulled in the moving direction when the polarizing plate 52 is attached due to its structure, there is a possibility that internal distortion occurs in the polarizing plate 52.

On the other hand, as another method for sticking a polarizing plate to a liquid crystal cell so that air bubbles do not enter, for example, Japanese Patent Laid-Open No. Sho 5 (1999) -58138.
There are those disclosed in JP-A-5-147612 and JP-A-2-277021. As shown in FIGS. 6 and 7, the publications disclosed in these publications eliminate the polarizing plate attaching roller 55, and bend the polarizing plate supports 61 and 71 of the polarizing plates 62 and 72 at the central portion. Forming a surface.

Then, the polarizing plate 62
In each of the pasting methods of 72, an elastic body such as rubber is formed on the polarizing plate supports 61 and 71, and the polarizing plates 62 and 72 are temporarily fixed thereto, and the curved surface apex of the polarizing plate supports 61 and 71 is fixed. It is pressed down vertically as it is. As a result, the sticking progresses from the center to the outside sequentially with the strain of the elastic body, and the polarizing plates 62 and 72 are stuck to the liquid crystal cells 63 and 73.

However, the above-mentioned method of attaching the polarizing plates 62 and 72 has a problem that the pressing force tends to be concentrated on the central portions of the liquid crystal cells 63 and 73, resulting in uneven pressing. Further, in the above disclosed example, the large polarizing plate 62.
When 72 is used, the polarizing plate supports 61 and 71 need to have a predetermined curvature in order to attach them while removing air bubbles. On the other hand, the distance from the polarizing plates 62 and 72 increases on the end side. Therefore, it can be easily imagined that the polarizing plates 62 and 72 cannot be adhered well.

Next, as another method for attaching a polarizing plate using another curved surface, for example, Japanese Patent Laid-Open No. 2-1014.
There is one disclosed in Japanese Patent No. 26. This disclosed technology
As shown in FIG. 8, the support 82 on the liquid crystal cell 81 side is curved, and the pressure roller method is used to attach the polarizing plate 83. Exists as well.

[0015]

As described above, all of the above-mentioned conventional film sticking devices for liquid crystal display elements have a problem that internal distortion or uneven pressing is caused in a film such as a polarizing plate. There is.

In particular, most of the current liquid crystal display elements use a retardation plate laminated type polarizing plate in which a retardation plate for compensating the birefringence of liquid crystal is laminated on the polarizing plate body.
This retardation plate-laminated polarizing plate has a problem that the retardation value of the retardation plate shifts due to the internal strain of the retardation plate being stretched, and a good display quality cannot be obtained. Further, if the deviation of the retardation value is to be minimized by the conventional sticking device for the polarizing plate, a great amount of labor is required for adjusting the sticking device. The above retardation value means that when a sample is arranged by a spectrophotometric method such that the optical axis is 45 degrees between crossed Nicols,
The wavelength at which the transmitted light is minimum.

The present invention has been made in view of the above conventional problems, and an object thereof is a liquid crystal display device having a simple structure without causing internal distortion or unevenness in the film for liquid crystal display device. It is to provide a sticking device for a film for use.

[0018]

In order to solve the above-mentioned problems, the film sticking device for liquid crystal display element according to the invention of claim 1 is provided with a film such as a polarizing plate having an adhesive material layer such as a liquid crystal cell. In a device for sticking a film for a liquid crystal display device to be stuck to a substrate of, the film facing surface has a curved surface that is convex to support the film, and the adhesive layer is temporarily arranged along the curved surface so that the adhesive layer is on the outside. Supporting means is provided for abutting the fixed film so that the edge portion of the film coincides with the edge portion of the substrate, and sticking the film along the substrate while rotating and pressing it following the advancing movement of the substrate. It is characterized by being.

An apparatus for laminating a film for a liquid crystal display element according to a second aspect of the present invention is the apparatus for laminating a film for a liquid crystal display element according to the first aspect, wherein the film is a polarizing plate having polarization and birefringence of liquid crystal. It is characterized by comprising a retardation plate laminated type polarizing plate in which a retardation plate for compensating the property is laminated.

[0020]

According to the structure of claim 1, when the liquid crystal display element film is attached to the substrate, first, a film such as a polarizing plate is supported along the curved surface so that the adhesive layer is on the outside. Temporarily fixed to. Next, the film temporarily fixed to the supporting means is brought into contact so that the edge portion of the film coincides with the edge portion of the substrate. Then, the support means adheres the film along the substrate while rotating and pressing the substrate while following the advancing movement of the substrate.

By adopting the above-mentioned pasting device,
A constant pressing force is always applied to the film, and the film and the substrate are attached without pulling each other.
Therefore, it is only necessary to rotate the supporting means having a curved surface without causing internal distortion or unevenness in the film, and to provide a simple sticking device for a display element film. You can

According to a second aspect of the present invention, the film comprises a retardation plate laminated type polarizing plate in which a polarizing plate having a polarizing property and a retardation plate for compensating the birefringence of liquid crystal are laminated. There is.

Therefore, the retardation value of the retardation plate does not shift even in the retardation plate type polarizing plate, which accounts for most of the use in the recent liquid crystal display element, and thereby the display quality as designed is obtained. In addition, it is possible to prevent display unevenness due to variations in retardation value shift.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

The film to which the film for a liquid crystal display device of the present embodiment is attached is a functional film used in the manufacture of a liquid crystal display device, such as a polarizing plate or AR.
It is a polymer film such as an (Anti-Reflection) film, an AG (Anti-Glare) film, a reflection film or an ultraviolet absorbing film. Here, a polarizing plate will be described as an example, and an application example of a retardation plate laminated type polarizing plate which accounts for most of the recent use in a liquid crystal display element will be described.

As shown in FIG. 2, the state of the retardation plate laminated type polarizing plate 1 before being attached is, as shown in FIG.
Adhesive surface 14 and adhesive surface side protective film 15 as an adhesive member
It is composed of The polarizing plate body 12
Is made of a polymer film having a polarization property as described above, while the retardation plate 13 is laminated in order to compensate the birefringence of the liquid crystal, and is also made of a polymer film. .

By the way, the liquid crystal display device is shown in FIG.
As shown in (b), generally, a liquid crystal cell (substrate) 3 formed by filling a liquid crystal between a pair of rigid substrates having transparent electrodes for display, and a liquid crystal cell 3 disposed on at least one surface of the liquid crystal cell 3. And a polarizing plate 1. Therefore, in the manufacturing process of the liquid crystal display element, as shown in FIG.
The liquid crystal cell 3 is fixed to the liquid crystal cell support 4 along a guide (not shown), and the liquid crystal cell 3 is conveyed by the movement of the liquid crystal cell support 4 in the traveling direction (the right direction in the figure). ing.

Further, the polarizing plate support 2 as a supporting means for supporting the polarizing plate 1 in this embodiment is shown in FIG.
As shown in (b), it has a substantially T-shaped cross section, is rotatable about the rotating shaft 2a, and the supporting surface for the polarizing plate 1 is a curved surface protruding toward the polarizing plate 1 side. Has been done. In the present embodiment, the rotating shaft 2
The radius of curvature R from a to the curved surface is, for example, 150 mm.

A hollow portion (not shown) is provided inside the polarizing plate support 2, while a plurality of suction holes (not shown) are formed on the surface of the polarizing plate support 2 on the polarizing plate 1 side. It is possible to temporarily fix the polarizing plate 1 by sucking the polarizing plate 1 from the suction hole using a vacuum pump that does not exist. The liquid crystal cell 3 is fixed by the liquid crystal cell support 4 shown in FIG. 3 (a) in the same manner.

The process of attaching the polarizing plate 1 fixed on the polarizing plate support 2 to the liquid crystal cell 3 is shown in FIG.
A description will be given based on (b) and FIGS. 1 (a) to 1 (d).

First, as shown in FIG. 3B, a guide plate (not shown) provided on the polarizing plate support 2 is a polarizing plate 1 having the adhesive surface side protective film 15 on the surface of the polarizing plate support 2. Place along. Then, the polarizing plate 1 is temporarily fixed by sucking the polarizing plate 1 from a suction hole (not shown) using a vacuum pump (not shown), and the adhesive surface side protective film 15 is peeled off to expose the adhesive surface 14. On the other hand, as shown in FIG. 3A, the liquid crystal cell 3 is fixed to the liquid crystal cell support 4 in advance and conveyed to the polarizing plate support 2 side.

Then, as shown in FIG. 1A, the polarizing plate support 2 is rotated by a pulse motor with a clutch (not shown) connected to the rotating shaft 2a of the polarizing plate support 2, and the end of the polarizing plate 1 is rotated. The polarizing plate support 2 is temporarily stopped at a position where the portion faces the liquid crystal cell 3.

Then, as shown in FIG. 1B, the liquid crystal cell support 4 is slid by a motor to move it below the polarization plate support 2. Then, air is introduced into a pressing chamber arranged in a column (not shown) of the polarizing plate support 2 to lower the polarizing plate support 2, and the polarizing plate 1 and the liquid crystal cell 3
Contact with. At this time, the slide amount of the liquid crystal cell support 4 is adjusted so that the edge of the polarizing plate 1 and the edge of the liquid crystal cell 3 facing the same are aligned with each other.

Then, as shown in FIG. 1 (c), the liquid crystal cell support 4 advances from the state in which the edge of the polarizing plate 1 and the edge of the liquid crystal cell 3 are in contact with each other, as shown by an arrow. Slide in the direction. At this time, the polarizing plate support 2 has the rotating shaft 2a.
The clutch of the pulse motor with a clutch (not shown) connected to is released so as to follow the sliding amount of the liquid crystal cell support 4. Then, Figure 1
As shown in (d), when the polarizing plate support 2 is separated from the polarizing plate 1, the attachment of the polarizing plate 1 to the liquid crystal cell 3 is completed. Further, this makes it possible to attach the polarizing plate 1 and the liquid crystal cell 3 so that air bubbles do not enter between them.

As described above, in the sticking device for the polarizing plate 1 of this embodiment, when the polarizing plate 1 is stuck to the liquid crystal cell 3, first, the polarizing plate 1 is polarized along the curved surface so that the glue surface 14 is on the outside. The plate 1 is temporarily fixed to the polarizing plate support 2. Next, the polarizing plate 1 temporarily fixed to the polarizing plate support 2 is brought into contact with the liquid crystal cell 3 so that its edge portion coincides with the edge portion of the liquid crystal cell 3. After that, the polarizing plate 1 is attached along the liquid crystal cell 3 while rotating and pressing the polarizing plate support 2 while following the advancing movement of the liquid crystal cell 3.

By adopting the above-mentioned sticking device for the polarizing plate 1, a constant pressing force is always applied to the polarizing plate 1, and the polarizing plate 1 and the liquid crystal cell 3 are stuck without pulling each other. Therefore, it is only necessary to rotate the polarizing plate support 2 having a curved surface in terms of structure without causing internal distortion or uneven pressing of the polarizing plate 1, and thus a simple device for sticking the polarizing plate 1 Can be provided.

Moreover, the condition of the apparatus can be easily set. Further, even when the large polarizing plate 1 is stuck, it can be stuck without any trouble.

Further, in the device for laminating a film for a liquid crystal display device of this embodiment, a polarizing plate body 12 having a polarizing property as a film and a retardation plate 13 for compensating the birefringence of liquid crystal are laminated. It is applicable to the polarizing plate 1 of the retardation plate laminated type.

Therefore, even in the retardation plate laminated type polarizing plate 1 which occupies most of the use in the recent liquid crystal display element, the retardation value (see the above definition) of the retardation plate 13 does not deviate. With this, it is possible to obtain a display quality as designed, and it is possible to prevent display unevenness due to variations in retardation value shifts.

Here, the performance evaluation test of the sticking device for the polarizing plate 1 of this example was conducted in comparison with the conventional example, and is shown below.

In the test, as the polarizing plate 1, a retardation plate laminated type polarizing plate 1 having a long side direction of 200 mm, a short side direction of 150 mm and a thickness of 0.4 mm was used. The same thing was used also in the conventional example. This retarder laminated type polarizing plate 1
Indicates that the polarizing plate body 12 has a single transmittance of 41.5% and a polarization degree of 9
9.95% neutral gray type (for example, "G1220DU" manufactured by Nitto Denko Corporation),
The polarizing plate body 12 is made of a uniaxially stretched polymer film (polycarbonate) and has a retardation value of 430 n.
The retardation plates 13 having a thickness of m are laminated.

Further, the sticking conditions at this time were such that the sticking pressure was 2.5 kgf / cm ² and the sticking speed (stage speed) was 100 mm / sec in both the embodiment and the conventional example. Table 1 shows the amount of change in retardation value in Examples and Conventional Examples. When measuring the retardation value, "TFM-120AFT" manufactured by Oak Co. was used.

From the results shown in Table 1, it can be seen that the retardation value does not change in the example. Further, the change in retardation value in the conventional example was 5 nm, but originally there was some variation within the plane of the retardation plate 13 itself, and the variation in retardation value seen in the large variation part and the conventional example. It has been found that when and overlap, the display quality deteriorates as display unevenness.

[0044]

[Table 1]

[0045]

As described above, the device for sticking a film for a liquid crystal display device according to the present invention has a curved surface having a convex surface facing the film to support the film, and the adhesive layer is outside. The film temporarily fixed along the curved surface is brought into contact so that the edge of the film is aligned with the edge of the substrate, and is pressed against the substrate while rotating and pressing in accordance with the advancing movement of the substrate. This is a configuration in which a supporting means for sticking along is provided.

As a result, a constant pressing force is always applied to the film, and the film and the substrate are attached without pulling each other. Therefore, it is only necessary to rotate the supporting means having a curved surface without causing internal distortion or unevenness in the film, and to provide a simple sticking device for a display element film. There is an effect that can be.

As described above, the device for sticking the film for liquid crystal display element of the invention of claim 2 is the same as the device for sticking the film for liquid crystal display element of claim 1, wherein the film comprises a polarizing plate having a polarizing property and a liquid crystal. The retardation plate laminated polarizing plate is formed by laminating a retardation plate for compensating the birefringence.

As a result, even in the retardation plate laminated polarizing plate which occupies most of the recent liquid crystal display elements,
The retardation value of the retardation plate does not shift, and thus display quality as designed can be obtained, and display unevenness due to variations in retardation value shift can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a sticking process by a sticking device for a polarizing plate according to an embodiment of the present invention, in which (a) shows a polarizing plate and a liquid crystal cell by rotating a polarizing plate support on which a polarizing plate is temporarily fixed. In a state where they are opposed to each other, (b) is a state in which the ends of the polarizing plate and the liquid crystal cell are in contact with each other, (c) is a state in which the polarizing plate is attached so as to follow the movement of the liquid crystal cell, (d) ) Indicates a state where the application is completed.

FIG. 2 is a schematic view showing a structure of the polarizing plate.

3A and 3B are explanatory views showing a structure of the above-mentioned polarizing plate sticking apparatus, wherein FIG. 3A is a liquid crystal cell fixed to a liquid crystal cell support, and FIG. 3B is a liquid crystal cell temporarily fixed to the polarization plate support. Is.

FIG. 4 shows a conventional example and is an explanatory view showing a structure of a sticking device for a polarizing plate.

FIG. 5 is an explanatory view showing a sticking process by the sticking device for the polarizing plate, wherein (a) shows a state in which the polarizing plate support on which the polarizing plate is temporarily fixed is rotated to make the polarizing plate and the liquid crystal cell face each other.
(B) shows a state where the ends of the polarizing plate and the liquid crystal cell are in contact with each other, (c) shows a state where the polarizing plate is pasted with a polarizing plate pasting roller, and (d) shows a state where the pasting is completed. It is shown.

FIG. 6 shows another conventional example and is an explanatory view showing the structure of a polarizing plate sticking device.

FIG. 7 shows still another conventional example, and is an explanatory view showing the structure of a sticking device for a polarizing plate.

FIG. 8 shows still another conventional example, and is an explanatory view showing the structure of a sticking device for a polarizing plate.

[Explanation of symbols]

 1 Polarizing Plate (Film) 2 Polarizing Plate Support (Supporting Means) 3 Liquid Crystal Cell (Substrate) 4 Liquid Crystal Cell Support 12 Polarizing Plate Main Body 13 Retardation Plate 14 Adhesive Surface (Adhesive Layer)

Claims (2)

[Claims] 1. A sticking device for a film for a liquid crystal display device, which sticks a film having an adhesive material layer on a substrate, wherein the film facing surface has a convex curved surface for supporting the film, and the adhesive material layer is The film, which is temporarily fixed along the curved surface so as to be on the outside, is brought into contact so that the edge of the film is aligned with the edge of the substrate, and the substrate is rotated and pressed while following the advancing movement of the substrate. A sticking device for a film for a liquid crystal display element, which is provided with a supporting means for sticking along. 2. The film comprises a polarizing plate having a polarizing property,
The device for sticking a film for a liquid crystal display element according to claim 1, comprising a retardation plate laminated type polarizing plate in which a retardation plate for compensating the birefringence of liquid crystal is laminated.