JP2731286B2 - Liquid crystal display device substrate alignment processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an LCD in which an alignment film applied on a substrate of a liquid crystal display device (hereinafter referred to as LCD) is rubbed with a rubbing cloth wound around a roller. Related to the substrate orientation processing device,
In particular, the present invention relates to an alignment processing apparatus suitable for rubbing alignment processing when manufacturing an S-TN type LCD.

[Related Art] A rubbing method is one method of aligning liquid crystal molecules in an LCD cell in a predetermined direction. In the rubbing method, at the time of manufacturing an LCD, the surface of an alignment film applied to cover a transparent electrode on a glass substrate is rubbed in a specific direction with a pile (rubber) of a rubbing cloth wound around a roller. Is performed).

That is, as shown in FIG. 3, a transparent electrode 2 is patterned on a glass substrate 1, an alignment film 3 is applied and formed on the transparent electrode 2, and then the glass substrate 1 is placed on a rubbing table (not shown). When the surface of the alignment film 3 is rubbed in a specific direction by the pile 7 of the rubbing cloth 4 while rotating the roller 5 around which the rubbing cloth 4 is wound in the direction of the arrow via the drive shaft 6, the long axis direction of the liquid crystal molecules is obtained. Are oriented in a direction parallel to the rubbing direction.

Roller 5 used for such rubbing orientation treatment
The rubbing cloth 4 having a plurality of piles 7 on its surface is usually a cylindrical body having a perfect circular cross section as shown in FIGS. The rubbing cloth 4 is wound, and a cloth 8 serving as a base is fixed to the roller 5 via a double-sided adhesive tape or the like. The rubbing cloth 4 is made by weaving a pile 7 of polyester fiber or the like into a cloth 8, and the length of the pile 7 is
It is set to about 1.2mm.

Then, in the rubbing alignment treatment of the S-TN type LCD substrate, the tip of the pile 7 is set to be 0.2 to 0.3 mm
The rubbing process is performed while the roller 5 is rotated at a high speed of about 1000 rotations per minute through the drive shaft 6 to secure the contact pressure.

[Problems to be Solved by the Invention] When the rubbing cloth 4 cut into a rectangular shape is wound around the roller 5 as shown in FIGS. 3 and 4, both ends 4a and 4b of the rubbing cloth 4 become seams. Since a large pulling force is applied to the ends 4a and 4b of the roller 5 at the time of cutting or rubbing, the ends 4a and 4b of the roller 4 are, as shown in FIG. Line). When the rubbing treatment is continued while the seam of the rubbing cloth 4 is wavy, the pile 7 of the ridged portion of the seam is strongly pressed against the alignment film 3, so that the surface of the alignment film 3 is deeply damaged. Are formed to easily cause uneven alignment, and the sliding resistance between the seam of the rubbing cloth 4 and the alignment film 3 is increased to increase the pulling force acting on the seam. It is easy to peel off from the roller 5 inside.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an LCD substrate alignment processing apparatus capable of always performing good rubbing alignment processing and preventing a rubbing cloth from being peeled off.

[Means for Solving the Problems] The object of the present invention is to wrap a rubbing cloth having a large number of piles on the outer surface of a roller along a circumferential direction and fix the rubbing cloth. In an alignment processing apparatus for an LCD substrate, in which an alignment film on a substrate is rubbed in a specific direction by a pile, a portion symmetrical with respect to an axis on an outer peripheral surface of the roller is chamfered flat along the axis. This is achieved by fixing both ends of the rubbing cloth, which are seams in the wound state, to approximately the center of one of the portions.

[Operation] According to the above-mentioned means, even if the seam of the rubbing cloth is in a wavy state, the seam is fixed at a substantially central position of the flat chamfered portion of the roller. The contact pressure of the pile gradually decreases from one end of the chamfered flat portion toward the center, becomes almost non-contact only in the vicinity of the seam, and the non-contact area is reduced, so that a deep scratch may be formed on the alignment film. Is eliminated, and the pulling force acting on the seam of the rubbing cloth during rotation of the roller is suppressed, so that the rubbing cloth is less likely to be peeled off. Since the unit is provided, the balance of the rotating roller is not impaired.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view of an alignment treatment apparatus according to the present embodiment, and FIG.
The figure is a perspective view of the roller, and portions corresponding to those in FIGS. 3 and 4 are denoted by the same reference numerals.

1 and 2, the outer peripheral surface of the substantially cylindrical roller 5 is
The portions symmetrical with respect to the axis (center line of the drive shaft 6) are each chamfered flat along the axis, and the chamfered amount t of these flat chamfered portions 5a and 5b is 0.5 mm. When the rubbing cloth 4 is wound around the roller 5, the rubbing cloth 4 is placed on the outer peripheral surface of the roller 5 such that both ends 4 a and 4 b serving as seams are positioned on one chamfered flat part 5 a. Wrap along the circumferential direction and fix via double-sided adhesive tape or the like.

A large number of piles 7 having a length of about 1.2 mm are provided on a fabric 8 serving as a base of the rubbing cloth 4 wound around the roller 5 in this manner.
The roller 5 is rotated 1000 times per minute via the drive shaft 6 while the tip of the pile 7 is pressed by about 0.2 to 0.3 mm against the alignment film of the S-TN type LCD substrate (not shown). A rubbing process is performed while rotating at a high speed.

However, the chamfered flat portion of the roller 5 of the rubbing cloth 4
The pile 7 of the portion fixed to 5a, 5b hardly performs a rubbing function because the amount of pushing into the alignment film is 0.2 mm or less. For example, the pile 7 at both ends 4a, 4b of the rubbing cloth 4 is designed. Are kept out of contact with the alignment film. Therefore, even if these ends 4a and 4b are wavy and partially bulged, there is no fear that the pile 7 is strongly pressed against the alignment film.

As described above, in the above embodiment, both ends 4a and 4b serving as seams of the rubbing cloth 4 are fixed substantially at the center of the chamfered flat portion 5a of the roller 5, and the alignment film of the pile 7 of the seam is provided. Care is taken not to increase the contact pressure with respect to rubbing, so that there is no danger that deep scratches will be formed on the surface of the alignment film during rubbing, and a good rubbing alignment process can always be performed. In addition, since the pulling force acting on the joint of the rubbing cloth 4 when the roller 5 rotates is suppressed, the risk of the rubbing cloth 4 causing a peeling accident is reduced.

In the above embodiment, since the chamfered flat portions 5a and 5b are provided at positions symmetrical with respect to the axis of the roller 5, the center of the roller 5 coincides with the center of gravity of the roller 5, and the rotating roller 5 Care has been taken to ensure that the balance of 5 is not compromised.

The pile 7 of the rubbing cloth 4 at the portion fixed to the chamfered flat portions 5a and 5b of the roller 5 hardly performs the rubbing function as described above.
Since the pile 7 is rotated at a high speed of m, there is no problem even if some piles 7 do not perform the rubbing function.

[Effects of the Invention] As described above, according to the present invention, since both ends serving as seams of the rubbing cloth are fixed at substantially the center positions of the flat chamfered portions of the rollers, the alignment film at the flat chamfered portions can be prevented. The contact pressure of the pile gradually decreases from one end of the chamfered flat portion toward the center, becomes almost non-contact only in the vicinity of the seam, and the non-contact area of the pile is reduced, so that the seam is wavy. Even if the pile of the seam eliminates the risk of forming a deep scratch on the alignment film, excellent hardening that a good rubbing alignment treatment can always be performed is achieved,
Since the pulling force acting on the joint of the rubbing cloth during rotation of the roller is suppressed, the effect of preventing the rubbing cloth from peeling off is also high.

[Brief description of the drawings]

1 and 2 relate to an embodiment of the present invention, FIG. 1 is a cross-sectional view of an alignment treatment apparatus, FIG. 2 is a perspective view of a roller thereof, and FIGS. 3 to 5 are related to a conventional example. FIG. 3 is a cross-sectional view for explaining a rubbing step, FIG. 4 is a perspective view of a conventional orientation processing apparatus used therein, and FIG. 5 is a main part showing a state where a seam of the rubbing cloth is wavy. FIG. 4 ... rubbing cloth, 4a, 4b ... end, 5 ... roller, 5a,
5b flat chamfer, 6 drive shaft, 7 pile, 8
... fabric.

Claims (1)

(57) [Claims] 1. A rubbing cloth having a large number of piles on its surface is wound around the outer peripheral surface of a roller along the circumferential direction and fixed, and while rotating the roller, the alignment film on the substrate is rubbed in a specific direction by the pile. In the alignment processing apparatus for a liquid crystal display element substrate to be processed, in the outer peripheral surface of the roller, a portion symmetrical with respect to the axis is chamfered flat along each axis, and at approximately the center position of one of these chamfered flat portions, An alignment treatment apparatus for a liquid crystal display element substrate, wherein both ends of the rubbing cloth which are wound in a wound state are fixed.