JP3004532B2 - Film sticking device for liquid crystal display element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for attaching a film having a pressure-sensitive adhesive layer, such as a polarizing plate, to a substrate such as a liquid crystal cell.

[0002]

2. Description of the Related Art In general, a liquid crystal display element comprises a liquid crystal cell in which liquid crystal is filled between a pair of substrates having a transparent electrode for display, and a polymer film disposed on at least one surface of the liquid crystal cell. And a polarizing plate comprising: For this reason, in a manufacturing process of a liquid crystal display element, an operation of attaching a polarizing film to a liquid crystal cell is performed.

A conventional method of attaching a polarizing plate to a liquid crystal cell includes a method called a pressure roller method. In this pressure roller method, a polarizing plate placed on the surface of a liquid crystal cell is applied. When the pressure roller runs 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 for attaching a polarizing plate by the above-mentioned pressure roller method will be described with reference to FIGS.

[0005] First, as shown in FIG.
The polarizing plate 52 with the adhesive surface facing up on the surface of the polarizing plate support 5
1 is placed along a guide (not shown) provided in the apparatus 1. At this time, the left end of the polarizing plate 52 is allowed to protrude from the polarizing plate support 51 by about 20 mm.

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 from 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 a guide provided on the liquid crystal cell support 54. The liquid crystal cell 53 is fixed to the liquid crystal cell support 54 in the same manner as in the case of the polarizing plate 52.

Next, as shown in FIG. 5A, after the glue surface laminator of the polarizing plate 52 is peeled off, the polarizing plate support 51 is removed.
Is reversed by a motor (not shown) to maintain the inclined state, and the glue 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 a motor drive (in FIG.
Move down. Next, air is introduced into a pressing chamber arranged on a support (not shown) of the polarizing plate attaching roller 55 to lower the polarizing plate attaching 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, at the contact portion between the polarizing plate 52 and the liquid crystal cell 53, the polarizing plate 5
The sliding amount of the liquid crystal cell support 54 is adjusted so that the edge protruding from the second polarizing plate support 51 and the edge of the liquid crystal cell 53 corresponding thereto are matched.

Next, as shown in FIG. 5C, the polarizing plate sticking roller 55 is pressed against the polarizing plate 52, and the liquid crystal cell support 54 is slid to the right, so that the polarizing plate 52 is supported by the polarizing plate. It is peeled off along the body 51 and attached to the liquid crystal cell 53. Thereafter, as shown in FIG. 5D, when the polarizing plate sticking roller 55 is separated from the polarizing plate 52, 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 adhered due to its structure, the polarizing plate 52 may be internally strained.

On the other hand, as another method of attaching a polarizing plate to a liquid crystal cell while preventing air bubbles from entering, see, for example,
There are those disclosed in JP-A-5-147612 and JP-A-2-277022. As disclosed in these publications, as shown in FIGS. 6 and 7, the polarizing plate sticking roller 55 is eliminated and the polarizing plates 62 and 72 have curved curved portions protruding at the center of the polarizing plate supports 61 and 71. Forming a surface.

[0012] The polarizing plate 62.
In any method of attaching 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 vertices of the polarizing plate supports 61 and 71 are fixed. It is pressed down vertically as it is. Thereby, the sticking proceeds sequentially from the center to the outside together with the distortion of the elastic body, and the polarizing plates 62 and 72 are stuck to the liquid crystal cells 63 and 73.

However, the above-described method of attaching the polarizing plates 62 and 72 has a problem that the pressing force is concentrated on the central portions of the liquid crystal cells 63 and 73 and uneven pressing tends to occur. Further, in the above disclosed example, the large polarizing plate 62.
When using 72, a predetermined curvature is required for the polarizing plate supports 61 and 71 in order to adhere while removing air bubbles, so that the polarizing plate supports 61 and 71 are inevitably On the other hand, the distance between the polarizers 62 and 72 on the end side increases. For this reason, it can easily be imagined that the polarizing plates 62 and 72 cannot be stuck well.

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

[0015]

As described above, any of the above-mentioned conventional film sticking apparatuses for liquid crystal display elements has a problem that a film such as a polarizing plate causes internal distortion or uneven pressing. I have.

In particular, in current liquid crystal display devices, a retardation plate laminated type polarizing plate in which a retardation plate for compensating birefringence of liquid crystal is laminated on a polarizing plate main body occupies most of the use.
The retardation plate-laminated polarizing plate has a problem that the retardation value of the retardation plate is extended due to the internal distortion and the retardation value of the retardation plate is shifted, so that good display quality cannot be obtained. In addition, if the deviation of the retardation value is to be minimized by the conventional polarizing plate sticking device, a great effort is required for adjusting the sticking device. Note that the above retardation value is determined by a spectrophotometric method when a sample is arranged so that the optical axis is 45 degrees between crossed Nicols.
The wavelength at which the transmitted light is minimized.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a liquid crystal display device having a simple structure without causing internal distortion or uneven pressing in a liquid crystal display device film. An object of the present invention is to provide a film sticking device.

[0018]

According to a first aspect of the present invention, there is provided an apparatus for attaching a film for a liquid crystal display element according to the first aspect of the invention. In a device for attaching a film for a liquid crystal display element to be attached to a substrate, a film-facing surface has a curved surface that is convex to support the film, and is temporarily formed along the curved surface so that the adhesive layer is outside. The fixed film is brought into contact so that the edge of the film coincides with the edge of the substrate, and the film is attached to the substrate.
In this case, the rotation is free, and a support means for sticking along the substrate while rotating and pressing following the advance movement of the substrate is provided.

The liquid crystal display element filter according to the second aspect of the present invention.
Lum sticking equipment is an adhesive material to solve the above problems.
For a liquid crystal display device, in which a film having a layer is attached to a substrate.
In order to support the film in the film sticking device
The film facing surface has a convex curved surface, and
Temporarily fixed along the curved surface so that the adhesive layer is on the outside
Make sure that the film edge matches the substrate edge.
So that the clutch connected to the rotating shaft
By making it free, it follows the advance movement of the board
Support means to stick along the substrate while rotating and pressing
It is characterized by being provided.

The filter for a liquid crystal display element according to the third aspect of the present invention.
In the Lum sticking device, the supporting means is connected to the rotating shaft.
Is rotated by the pulse motor with clutch
With the means temporarily stopped, lower the film and substrate
The edge of the film and the
With the edge of the substrate facing
By setting the clutch of the pulse motor with
The instruction means follows the movement advance of the substrate,
Is attached to a substrate.

According to a fourth aspect of the present invention, there is provided a liquid crystal display element film sticking apparatus according to any one of the first to third aspects, wherein the film has a polarizing property. And a retardation plate laminated type polarizing plate in which a retardation plate for compensating birefringence of liquid crystal is laminated.

[0022]

According to the first to third aspects, when the film for a liquid crystal display element is affixed to a substrate, first, a film such as a polarizing plate is formed along a curved surface so that the adhesive layer is on the outside. Temporarily fixed to the support means. Next, the film temporarily fixed to the supporting means is brought into contact with the substrate so that the edge coincides with the edge of the substrate. Then, a film is adhered along the substrate by the support means while rotating and pressing the substrate following the advance movement of the substrate.

By adopting the above-mentioned sticking device,
A constant pressing force is always applied to the film, and the film and the substrate are stuck together without pulling each other.
Therefore, it is possible to provide a simple display device film sticking device, since the film does not cause internal distortion or uneven pressing, and the structure only requires rotating the support means having a curved surface. Can be.

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

For this reason, even in a retardation plate laminated type polarizing plate which occupies most of the use in recent liquid crystal display devices, the retardation value of the retardation plate does not deviate, and as a result, display quality as designed can be achieved. It is possible to prevent display unevenness due to variations in retardation value obtained.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

The film to which the film for a liquid crystal display device of the present embodiment is to be attached is a functional film used for manufacturing a liquid crystal display device, for example, a polarizing plate, AR
Polymer films such as (Anti-Reflection) films, AG (Anti-Glare) films, reflection films, and ultraviolet absorption films. Here, the polarizing plate is taken up for explanation, and particularly, an example of application to a retardation plate-laminated polarizing plate, which occupies most of recent uses in liquid crystal display devices, is explained.

As shown in FIG. 2, the state before the lamination of the retardation plate laminated type polarizing plate 1 is such that the polarizing plate side protective film 11, the polarizing plate main body 12, the retardation plate 13,
Glue surface 14 and glue 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 polarizing property as described above, while the retardation plate 13 is laminated to compensate for the birefringence of the liquid crystal, and is also made of a polymer film. .

The liquid crystal display element is shown in FIG.
As shown in (b), generally, a liquid crystal cell (substrate) 3 in which liquid crystal is filled between a pair of rigid substrates having a transparent electrode 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. For this reason, 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 moving the liquid crystal cell support 4 in the traveling direction (rightward in the figure). ing.

Further, a 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), the section has a substantially T-shape, is rotatable about a rotation axis 2a, and a support surface for the polarizing plate 1 is formed as a curved surface protruding toward the polarizing plate 1 side. Have been. In this embodiment, the rotating shaft 2
The radius of curvature R from a to the curved surface is, for example, 150 mm.

A cavity (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 side of the polarizing plate 1. A temporary fixing of the polarizing plate 1 can be performed by sucking the polarizing plate 1 from the suction hole using a vacuum pump which is not used. The fixing of the liquid crystal cell 3 by the liquid crystal cell support 4 shown in FIG.

FIG. 3 (a) shows the step of attaching the polarizing plate 1 fixed to the polarizing plate support 2 to the liquid crystal cell 3.
This will be described with reference to FIG. 1B and FIGS.

First, as shown in FIG. 3 (b), a polarizing plate 1 with the adhesive side protective film 15 facing up on the surface of the polarizing plate support 2 is provided with a guide (not shown) provided on the polarizing plate support 2. Place along. Next, 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 glue surface side protective film 15 is peeled off to expose the glue 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 is conveyed to the polarizing plate support 2 side.

Next, 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.

Next, as shown in FIG. 1B, the liquid crystal cell support 4 is slid by a motor to be moved below the polarizing plate support 2. Then, air is introduced into a pressing chamber arranged in a support (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 are lowered.
And contact. 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 edge coincide.

Next, as shown in FIG. 1C, the liquid crystal cell support 4 is moved in the direction indicated by the arrow from the state where the edge of the polarizing plate 1 and the edge of the liquid crystal cell 3 are in contact with each other. Slide in the direction. At this time, the polarizing plate support 2 is
By setting the clutch of the pulse motor with clutch (not shown) connected to the motor to be free, the sliding amount of the liquid crystal cell support 4 is followed. Then, FIG.
As shown in (d), when the polarizing plate support 2 separates from the polarizing plate 1, the attachment of the polarizing plate 1 to the liquid crystal cell 3 is completed. Further, thereby, it is possible to attach the polarizing plate 1 and the liquid crystal cell 3 while preventing air bubbles from entering.

As described above, when the polarizing plate 1 is attached to the liquid crystal cell 3 in the present embodiment, the polarizing plate 1 is first polarized along the curved surface so that the adhesive 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 the edge thereof coincides with the edge of the liquid crystal cell 3. Thereafter, the polarizing plate 1 is adhered along the liquid crystal cell 3 while being rotationally pressed by the polarizing plate support 2 following the advance movement of the liquid crystal cell 3.

By employing the above-described device for attaching 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 attached without being pulled together. Therefore, the polarizing plate 1 does not cause internal distortion or unevenness in the pressure, and the structure is only required to rotate the polarizing plate support 2 having a curved surface. Can be provided.

Further, it is possible to easily determine the conditions of the apparatus. Furthermore, even when the large polarizing plate 1 is attached, it can be attached without any trouble.

Furthermore, in the liquid crystal display element film sticking apparatus of the present embodiment, a polarizing plate body 12 having a polarizing property as a film and a retardation plate 13 for compensating birefringence of the liquid crystal are laminated. This is applicable to the polarizing plate 1 of the retardation plate laminated type.

Therefore, the retardation value of the retardation plate 13 (see the above definition) does not deviate even in the retardation plate-laminated polarizing plate 1 occupying most of recent liquid crystal display elements. Thus, display quality as designed can be obtained, and display unevenness due to variation in retardation value deviation can be prevented.

Here, the performance evaluation test in the pasting device of the polarizing plate 1 of the present embodiment was performed in comparison with the conventional example, and is shown below.

In the test, a polarizing plate 1 of a phase difference plate type having a length of 200 mm in the long side direction, 150 mm in the short side direction, and a thickness of 0.4 mm was used as the polarizing plate 1. The same thing was used also in the conventional example. This retardation plate laminated polarizing plate 1
Means 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 430n.
This is a stack of the retardation plates 13 of m.

The sticking conditions at this time were set to a sticking pressure of 2.5 kgf / cm ² and a sticking speed (stage speed) of 100 mm / sec in both the embodiment and the conventional example. Table 1 shows the amount of change in the retardation value in the example and the conventional example. In measuring the retardation value, “TFM-120AFT” manufactured by Oak Co. was used.

From the results shown in Table 1, it can be seen that there is no change in the retardation value in the example. Further, the change in the retardation value in the conventional example was 5 nm, but originally there was some variation in the plane of the retardation plate 13 itself, and the portion where this variation was large and the change in the retardation value observed in the conventional example were large. It has been found that when these overlap, the display quality is reduced as display unevenness.

[0046]

[Table 1]

[0047]

As described above, the film sticking device for a liquid crystal display element according to the first aspect of the present invention has a curved surface in which the film-facing surface is convex to support the film, and the pressure-sensitive adhesive layer has an outer surface. The film temporarily fixed along the curved surface is brought into contact with the film so that the edge of the film coincides with the edge of the substrate, and the film is attached to the substrate.
In this case, the rotation is free, and a supporting means is provided for sticking along the substrate while rotating and pressing the substrate following the advance movement of the substrate.

A film for a liquid crystal display device according to the invention of claim 2
Should be able to support the film as described above.
The film facing surface has a convex curved surface
Temporarily fix along the curved surface so that the adhesive layer is on the outside.
The edge of the film matches the edge of the substrate
And the clutch connected to its rotating shaft
Following the board movement
Means to stick along the substrate while rotating and pressing
Is provided.

The film for a liquid crystal display device according to claim 3
As described above, the attaching device of
Rotated by a pulse motor with clutch connected to the
Then, with the support means stopped temporarily,
The edge of the film by contacting the
And the edge of the substrate facing it,
Release the clutch of the above pulse motor with clutch.
This allows the indicating means to follow the movement advance of the substrate.
In this configuration, the film is attached to the substrate.

As a result, a constant pressing force is always applied to the film, and the film and the substrate are stuck together without being pulled. Therefore, it is possible to provide a simple display device film sticking device, since the film does not cause internal distortion or uneven pressing, and the structure only requires rotating the support means having a curved surface. This has the effect that it can be performed.

The liquid crystal display device film sticking apparatus according to the fourth aspect of the present invention is, as described above, any one of the first to third aspects.
In the patch device for a liquid crystal display element film or the film in the structure consisting of a phase difference plate laminated polarizing plate by laminating a phase difference plate for compensating a polarizing plate having a polarization, a birefringence of the liquid crystal is there.

As a result, even in a retardation plate laminated type polarizing plate which occupies most of recent liquid crystal display devices,
A retardation value shift of the retardation plate does not occur, whereby display quality as designed can be obtained, and display unevenness due to a variation in retardation value shift can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a sticking step by a sticking apparatus for a polarizing plate according to one embodiment of the present invention. FIG. 1 (a) shows a polarizing plate and a liquid crystal cell formed by rotating a polarizing plate support on which a polarizing plate is temporarily fixed. (B) is a state where the ends of the polarizing plate and the liquid crystal cell are in contact with each other, (c) is a state where the polarizing plate is adhered so as to follow the movement of the liquid crystal cell, (d) ) Indicates a state where the attachment 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 shows a liquid crystal cell fixed to a liquid crystal cell support, and FIG. 3B shows a liquid crystal cell temporarily fixed to a polarizing plate support. It is.

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

FIG. 5 is an explanatory view showing a sticking step by the sticking device of the polarizing plate, in which (a) shows a state in which a polarizing plate support on which the polarizing plate is temporarily fixed is rotated so that the polarizing plate and the liquid crystal cell face 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 stuck by a polarizing plate sticking roller, and (d) is a state in which the sticking is completed. It is shown.

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

FIG. 7 is a view showing still another conventional example and is an explanatory view showing a structure of a polarizing plate sticking apparatus.

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

[Explanation of symbols]

 Reference Signs List 1 polarizing plate (film) 2 polarizing plate support (supporting means) 3 liquid crystal cell (substrate) 4 liquid crystal cell support 12 polarizing plate body 13 retardation plate 14 adhesive surface (adhesive layer)

Claims (4)

(57) [Claims] 1. An apparatus for attaching a film having a pressure-sensitive adhesive layer to a substrate for bonding a film for a liquid crystal display element to a substrate, wherein the pressure-sensitive adhesive layer has a curved surface having a convex surface facing the film to support the film. The film temporarily fixed along the curved surface so as to be on the outside is brought into contact with the film so that the edge of the film coincides with the edge of the substrate.
When attaching the above film to the
And a support means for sticking along the substrate while rotating and pressing the substrate following the advance movement of the substrate. 2. A film having an adhesive layer is attached to a substrate.
In a device for attaching a film for a liquid crystal display device, a bay in which the film facing surface is convex to support the film.
With a curved surface, so that the adhesive layer is on the outside
Place the film temporarily fixed along the curved surface on the edge of the film.
Part of the board is aligned with the edge of the board.
By releasing the clutch connected to the shaft,
While following the advance movement of the substrate, the pressure
It is characterized in that support means for attaching
For sticking films for liquid crystal display devices. 3. The support means is connected to a rotating shaft thereof.
The film is rotated by a pulse motor with a clutch and lowered while the support means is stopped once.
The edge of the film and its edge are brought into contact with the substrate.
The edge of the substrate opposing this is made coincident, and the clutch of the pulse motor with clutch is released.
This allows the indicating means to follow the movement advance of the substrate.
3. A film is attached to a substrate by pressing.
A sticking device for the film for a liquid crystal display element according to the above. 4. The film comprises a polarizing plate having a polarizing property,
The film sticking device for a liquid crystal display element according to any one of claims 1 to 3, comprising a retardation plate laminated type polarizing plate in which a retardation plate for compensating birefringence of liquid crystal is laminated. .