JPH11237636A - Production of liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain satisfactory display quality while reducing non-uniformity in display by raising rubbing cloth so that the top end part of pile can be located backward rather than the root part of pile with the rotating direction of a roller as a reference. SOLUTION: Rubbing cloth is worked so that the central axis of a pile 5 is inclined in a fixed direction from the vertical direction of warp 3. An inclination angle θ of the pile 5 is not especially limited but it is preferable that this angle is settled within the range of 5 to 45 deg.. By winding such rubbing cloth around the outer peripheral surface of the rotary roller while using a double coated adhesive tape or the like, a rubbing roller is constituted. The rubbing cloth is added so that the top end part of the pile 5 can be located backward rather than the root part with the rotating direction of the rubbing roller as a reference, namely, the direction of an arrow can be almost coincident with the rotating direction of the roller. Thus, since the pile 5 is inclined backward in the rotating direction of the roller beforehand, the falling direction of the pile 5 can be controlled at the time of rubbing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a method for manufacturing a liquid crystal display device having less display unevenness due to uneven rubbing.

[0002]

2. Description of the Related Art At present, liquid crystal display devices are used in various fields such as notebook personal computers. However, with the improvement of image quality of personal computer software, display quality has been improved, that is, more uniform display over the entire screen has been achieved. Realization is a challenge. In particular, a super twisted nematic (hereinafter, referred to as “STN”) liquid crystal display element is liable to cause display unevenness due to a display system using a birefringence index. The precision of smoothness is improved.

In addition to the display unevenness caused by the above-described display method, unevenness in alignment of liquid crystal molecules may be considered as a factor affecting display uniformity. One of the causes of such alignment unevenness is uneven rubbing in the alignment treatment. Rubbing is a method of rubbing (rubbing) the surface of an alignment film such as a polyimide resin formed on a substrate in a certain direction and aligning liquid crystal molecules in a rubbing direction, and is widely adopted as an alignment treatment method for liquid crystal molecules. ing. In general, rubbing is performed by winding a rubbing cloth in which a bundle of short fibers (pile 5) is woven into a base weft composed of warp and weft and raised as shown in FIG. This is performed by bringing the roller into contact with the substrate while rotating the roller.

There are various types of luminance unevenness caused by the unevenness of the rubbing, and different countermeasures are taken for each of them. In Japanese Patent Application Laid-Open No. 9-73087, FIG.
It has been pointed out that, as shown in FIG. 0, streak-like uniform brightness unevenness caused by unevenness of pile contact occurs when the liquid crystal display element is turned on. As a countermeasure, in the above-mentioned publication, a rubbing roller wound with a rubbing cloth is used so that the direction in which the piles are arranged is inclined with respect to the rotation direction. As shown in FIG.
It has been proposed that the rubbing is performed while the substrate 2 is inclined with respect to the moving direction while the rotation axis of the substrate 2 is kept perpendicular to the moving direction of the substrate 2. In Japanese Unexamined Patent Application Publication No. Hei 22-22624, as shown in FIG. 4, the pile axis is inclined by ± 1 ° to ± 45 ° with respect to the vertical direction of the moving direction of the substrate 2. A method for avoiding linear unevenness due to the cracks of the hair tips is disclosed.

[0005]

However, even if the above-described countermeasures for improving the rubbing non-uniformity are taken, even if the above-described measures are taken, the rubbing may be performed in a direction parallel to the moving direction of the substrate as shown in FIGS. It has been difficult to reduce random unevenness in the occurrence position and width, such as the streaky display unevenness a1 and b1 and the wide band-shaped unevenness a2 and b2.

An object of the present invention is to provide a method for manufacturing a liquid crystal display element having less display unevenness and good display quality.

[0007]

In order to achieve the above object, a method of manufacturing a liquid crystal display device according to the present invention comprises forming a pile raised on a rubbing cloth on a substrate as a step for controlling the alignment of liquid crystal molecules. A method of manufacturing a liquid crystal display element, comprising the step of rubbing the surface of the alignment film by moving in a certain direction while making contact with the surface of the alignment film, wherein the rubbing cloth has a tip of the pile with respect to the direction. The portion is raised so that the portion is located behind the hair root of the pile. With such a configuration, the pile of the rubbing cloth is
Since the pile is tilted backward with respect to the moving direction of the pile in advance, it is possible to control the direction in which the pile tips fall when the pile comes into contact with the substrate. Accordingly, uniform rubbing can be realized over the entire surface of the alignment film, and a liquid crystal display device with high display quality can be obtained.

In the method of manufacturing a liquid crystal display device, the rubbing step is usually performed by rotating a rotating roller around which the rubbing cloth is wound while approaching a substrate moving in a predetermined direction. .

In the method of manufacturing a liquid crystal display element,
The rubbing cloth is arranged so that the piles form a line in at least one direction, and the parallel direction of the piles is inclined with respect to the rotating direction of the rotating roller. Preferably, it is wound. At this time, it is preferable that the angle between the parallel direction of the pile and the rotation direction of the rotating roller is 3 ° to 45 °. According to this preferred example, since the parallel direction of the piles is inclined with respect to the rotation direction of the rollers, the positions where the piles contact on the substrate are appropriately dispersed, and uniform rubbing can be reliably realized. .

In the method for manufacturing a liquid crystal display device, it is preferable that a rotation axis of the rotation roller is inclined with respect to a direction perpendicular to a direction in which the substrate moves.
The angle between the rotation axis and the direction perpendicular to the substrate moving direction may be less than 20 °, but is preferably 20 ° to 90 °. According to this preferred example, since the moving direction of the substrate and the rotating direction of the roller do not match, it is also possible to reduce unevenness due to the tip cracks of the pile,
Further, uniform rubbing can be reliably performed.

[0011] In the manufacturing method, the rubbing cloth may have an elongation of 1 kg / cm in a direction corresponding to a rotation direction of the rotating roller.
It is preferable to have a characteristic of being 10% or less.

Further, in the manufacturing method, n rubbing cloths whose dimension in the direction corresponding to the rotation direction of the rotating roller is less than 1 / n of the circumference of the rotating roller are provided on the rotating roller. Preferably, it is wound at intervals. Where n is a natural number of 2 or more,
Preferably it is 2-4.

According to these preferred examples, it is possible to reduce the deflection of the rubbing cloth during the rubbing process, and it is possible to more reliably realize uniform rubbing.

In the above-mentioned manufacturing method, in the rubbing step, the shortest distance between the root of the pile and the surface of the alignment film is determined by setting the length of the pile to P (mm), the inclination angle of the pile. Is θ (°), Pcos θ
Is preferably performed in a state 0.2 to 0.7 mm smaller than the value represented by However, the inclination angle θ of the pile
Is the angle formed by the pile and a normal to the outer peripheral surface of the rotating roller passing through the root of the pile.

In the above-described manufacturing method, it is preferable that one substrate is rubbed a plurality of times in the same direction.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of a manufacturing process of a liquid crystal display device will be described with reference to FIGS. 5 and 6 are a bird's-eye view and a sectional view of the liquid crystal display element. The transparent electrodes 11a and 11b are formed on the surfaces of the transparent substrates 10a and 10b. Usually, a glass substrate or a flexible film substrate is used for the transparent substrates 10a and 10b, and the transparent electrodes 11a and 11b are formed by a metal oxide film such as an ITO film or a NESA film. This transparent substrate 10a, 1
On the surface on which the electrode 0b is formed, an alignment film 1 of polyimide or the like is formed.
After forming the films 2a and 12b, the surface of the alignment film is rubbed. The two transparent substrates 10a, 1
After the sealing material 13 is printed and dried on the outer end portion inside the inner surface of Ob, and the spacer 14 is scattered over the entire display portion surrounded by the sealing material, the two transparent substrates 10a and 10b are opposed to each other with an arbitrary gap. Adhesive assembly to produce a liquid crystal cell. A liquid crystal 15 is injected into the cell, and a retardation plate 16 and deflection plates 17a and 17b are provided on the front and back surfaces of the cell.

The method for manufacturing a liquid crystal display element of the present invention is characterized by the rubbing step of the above manufacturing steps, and the other steps can be performed by a conventional method. In the rubbing step, the substrate on which the alignment film is formed is disposed close to a rubbing roller formed by winding a rubbing cloth in which a bundle (pile) of a large number of short fibers is planted around the outer peripheral surface of the rotating roller, This is performed by moving the substrate in one direction while rotating the roller and rubbing the surface of the alignment film in one direction. Hereinafter, the rubbing step in the present invention will be described in detail.

As shown in FIG. 1, the rubbing cloth used in the production method of the present invention is composed of several dozen short fibers (filaments) bundled on a base woven so that the warp yarns 3 and the weft yarns 4 are orthogonal to each other. The pile 5 is woven into the weft yarn 3 and has a raised structure. As shown in FIG. 1, the normal pile 5 is planted so as to be arranged in a direction substantially parallel to the warp. FIG. 2 is a diagram showing a cross section of the rubbing cloth. Strictly speaking, the pile 5 has a substantially conical shape in which the respective filaments are spread at the distal end portion. However, for simplicity, FIG. 2 shows only the central axis of the cone formed by the pile. In the conventional rubbing cloth, as shown in FIG. 2A, the pile 5 is raised so that the center axis thereof substantially coincides with the perpendicular direction of the ground surface. As shown in FIG. 2B, the rubbing cloth is processed such that the central axis of the pile is inclined in a certain direction from the direction perpendicular to the ground surface. The pile inclination angle θ is not particularly limited, but is preferably 5 to 4
5 °.

A rubbing roller is formed by winding such a rubbing cloth around the outer peripheral surface of a rotating roller with a double-sided adhesive tape or the like. The rubbing cloth is arranged such that the tip of the pile is located on the rear side of the hair root based on the rotation direction of the rubbing roller, that is, in FIG. It is provided so as to substantially coincide with the rotation direction. Since the pile is tilted backward with respect to the rotation direction of the roller in advance by providing in this manner, the direction in which the pile falls during rubbing can be controlled.
It is possible to reduce random display unevenness of the occurrence position and width as shown in FIGS.

In the above rubbing roller, the angle between the direction in which the piles are arranged in parallel, usually the direction of the warp of the rubbing cloth, and the direction of rotation of the rubbing roller is 3-4.
5 °, more preferably 5 ° to 30 °.
°. If the rotation direction of the rubbing roller matches the parallel direction of the piles, the positions where the piles contact each other on the substrate surface are likely to overlap. On the other hand, according to this preferred example, since the rotation direction of the rubbing roller is different from the parallel direction of the piles, the contact positions of the piles are dispersed in the rotation axis direction, so that more uniform rubbing is possible. As shown in FIG. 3, such a rubbing roller is used to cut the rubbed cloth in the direction of the length of the cut rubbing cloth (L in FIG. 3) (in the direction of rotation of the roller when attached to the rotating roller). (Corresponding direction) so as to be inclined by a predetermined angle (α) with respect to the warp, and winding this so that the L direction is parallel to the end face of the rotating roller.

The rubbing roller is preferably formed so that the rubbing cloth does not bend during rubbing. This is because the deflection of the rubbing cloth may cause uneven brightness running in a direction parallel to the rotation axis as shown in FIG. 12 to appear at equal intervals in the rotation direction. Therefore, it is preferable that the rubbing cloth has a small elongation percentage in the direction corresponding to the rotation direction in the rubbing roller. Specifically, the rubbing cloth preferably has an elongation of 10% or less when a tensile stress of 1 kg / cm is applied in a direction corresponding to the rotation direction. The elongation percentage of the rubbing cloth is related to the cutting angle (α in FIG. 3) when the rubbing roller is manufactured by the above-described method, as well as the type of the base of the rubbing cloth to be used. , Α increase, the elongation percentage also increases. Therefore, the value of α is set in consideration of the characteristics of the rubbing cloth to be used, while balancing the effect obtained by inclining the attachment direction of the rubbing cloth and the effect obtained by avoiding the bending. Is preferred.

Also, by manufacturing the rubbing roller using a plurality of rubbing cloths having a relatively short length in the rotation direction, the unevenness caused by the deflection of the rubbing cloth can be reduced. That is, the rubbing roller can be manufactured by winding n rubbing cloths whose length in the direction corresponding to the rotation direction is less than 1 / n of the circumference of the rotation roller at equal intervals on the outer peripheral surface of the rotation roller. preferable. At this time, 2 to 4 is appropriate for n.

The substrate is rubbed using the rubbing roller as described above. At this time, it is preferable that the rotation axis of the rubbing roller has an inclination with respect to a direction perpendicular to the moving direction of the substrate. This is because if the rotation direction of the rubbing roller matches the moving direction of the substrate, the bristle tip of the pile is likely to be broken, making uniform rubbing difficult. It is preferable that the angle (β shown in FIG. 4) formed by the rotation axis and the direction perpendicular to the substrate moving direction is 20 ° to 90 ° because unevenness due to the deflection of the rubbing cloth can be reduced. Further, the arrangement of the substrate is not particularly limited, but if the rectangular substrate is arranged so that one side thereof is parallel to the moving direction, the unevenness generated when the corner portion of the substrate contacts the rubbing roller is reduced. Can be preferred. The rotation speed of the rubbing roller is 600 to 12 with a roller having a diameter of 150 mm.
The rotation speed of the substrate is preferably 00 to 80 mm / sec.

In the rubbing, the shortest distance between the root of the pile and the surface of the alignment film is determined by setting the length of the pile to P
(Mm), when the inclination angle of the pile is θ (°), P
It is preferable to perform the process in a state 0.2 to 0.7 mm smaller than the value represented by cos θ. At this time, the length P of the pile is suitably 1.7 to 2.0 mm. As a result, while keeping the deflection of the rubbing cloth and the damage to the surface of the alignment film sufficiently small, it is possible to make the filament hit the substrate more densely than when only the tip of the pile contacts the substrate surface. , More uniform rubbing is realized. Further, it is preferable that rubbing is performed a plurality of times on the same substrate in the same direction. The number of rubbings in this case is preferably two to three times.

Through the above-mentioned rubbing step, uniform alignment of liquid crystal molecules can be realized, and good display quality can be obtained. In addition, the manufacturing method of the present invention can be applied to an alignment method such as an STN liquid crystal display, a twisted nematic (TN) liquid crystal display, an in-plane switching (IPS) liquid crystal display, an optically compensated bend (OCB) liquid crystal display, and the like. The present invention can be applied to the manufacture of any liquid crystal display element requiring processing.

[0026]

The present invention will be described below with reference to specific examples. In the examples, in order to more clearly confirm the effects of the present invention, the manufacture of an STN liquid crystal display element in which rubbing non-uniformity is easily reflected as luminance unevenness is illustrated.

(Measurement of Elongation Ratio of Rubbing Cloth) A rubbing cloth having a structure as shown in FIG. 7 was used. Cupra rayon manufactured by Asahi Kasei Kogyo Co., Ltd. was used for the warp yarns 3 and weft yarns 4 of the base, and the pile 5 used was a 120 denier pile diameter made of viscose rayon manufactured by Kuraray having a filament diameter of 3 denier. A vinyl acetate resin 7 was applied to the back surface of the rubbing cloth on which the pile was planted (the surface on which the hair tips of the pile did not protrude) to prevent the pile from coming off and the base from being deformed. The total thickness D of the rubbing cloth was 1.8 mm, the average length P of the pile was 1.8 mm, and the average inclination angle θ of the pile was 15 °.

In order to measure the elongation percentage of the rubbing cloth, the rubbing cloth was measured by setting the angle α shown in FIG.
Width 5c so as to be 0 °, 15 °, 30 °, 45 °
m and 30 cm in length were cut into six test pieces. For each test piece, a tensile stress of 5 kg (that is, 1 kg / cm per width) was applied in the length direction (L direction), and the elongation was measured. Table 1 shows the results. However, the elongation percentage S (%) is
Assuming that the original length is L ₀ and the length when stress is applied is L ₁ , this is a value represented by S = (L ₁ −L ₀ ) / L ₀ × 100.

[0029]

[Table 1]

(Example 1) A rubbing cloth raw material similar to that used for measuring the elongation percentage of the rubbing cloth was cut into a rectangle having a length equal to the outer circumference of the rotating roller to obtain a rubbing cloth. Was wound with a double-sided adhesive tape so that the length (L in FIG. 3) direction of the rubbing cloth was parallel to the end face of the rotating roller to produce a rubbing roller. As shown in FIG. 4, the rubbing roller was installed such that the rotation axis was inclined with respect to a direction orthogonal to the direction of movement of the substrate, and the substrate was rubbed. On the substrate, a polyimide prepolymer (PSI2204 manufactured by Chisso Petrochemical Co., Ltd.) was applied and cured by a conventional method on the surface on which the transparent electrode was formed, and an alignment film was formed. The inclination angle of the roller (β in FIG. 4) is 10 ° for the first transparent substrate and 60 ° for the second transparent substrate, and the twist angle in the alignment direction between the upper and lower substrates when a liquid crystal cell is manufactured is The angle was set to 250 °. A rubbing roller having a diameter of 150 mm was used, the rotation speed of the roller was 900 rpm, and the moving speed of the substrate was 4 mm.
0 mm / sec. After 200 spacers per 1 mm ² were scattered on the rubbed upper and lower substrates, a sealing material was applied to the outer end of the substrate, and the upper and lower substrates were attached to each other to produce a liquid crystal cell. As the spacer, the particle diameter is 6.1.
Using Sekisui Fine Co., Ltd.
The thickness of the liquid crystal layer was 6 μm. Liquid crystal was injected from an injection port formed in a part of the seal by a vacuum injection method. The liquid crystal material has a refractive index anisotropy (Δ
A composition with n) of 0.15 was used. A polarizing plate and a retardation plate were attached to the top and bottom of a liquid crystal cell whose inlet was sealed with an ultraviolet curable resin to obtain a liquid crystal display device.

In the above manufacturing method, as shown in Table 2, 30 kinds of samples were prepared by changing the cutting angle (α in FIG. 3) of the rubbing cloth and the pile pushing amount during rubbing. The pushing amount is Pcos
With θ (= 1.74 mm) as the reference (pressing amount 0),
The vertical distance between the rubbing roller and the substrate during rubbing is represented by the amount of decrease with respect to the reference.

[0032]

[Table 2]

For each of the prepared samples, an electric signal is applied between the electrodes at a voltage equal to or higher than the threshold value of the liquid crystal to generate display irregularities (streak-like irregularities a1, b1 and band-like irregularities a1 and a2 shown in FIG. 11).
Table 2 shows the results of observation of 2, b2 and unevenness at equal intervals shown in FIG.

[0034]

[Table 3]

The observation results are based on the degree of unevenness observed in a sample manufactured using a conventional rubbing cloth as shown in FIG. 2A, in which the brushing direction of the pile coincides with the perpendicular direction of the base. (X), Δ indicates that the unevenness is smaller than the reference, and O indicates that the unevenness is significantly reduced than the reference, and is evaluated in three steps.

Example 2 A manufacturing method similar to that of Example 1 was adopted except that the inclination angle (β in FIG. 4) of the rotation axis of the rubbing roller was 35 ° for both the first and second substrates. By changing the cutting angle (α in FIG. 3) of the rubbing cloth and the amount of pile pushed in during rubbing, 15 types of samples were produced as shown in Table 4.

[0037]

[Table 4]

For each of the prepared samples, an electric signal is applied between the electrodes at a voltage equal to or higher than the threshold value of the liquid crystal, and the resulting display unevenness (streak-like unevenness a1, b1 and band-like unevenness a shown in FIG. 11).
Table 2 shows the results of observation of 2, b2 and unevenness at equal intervals shown in FIG. However, evaluation criteria are the same as in the first embodiment.

[0039]

[Table 5]

(Example 3) Two rubbing cloths obtained by cutting the same rubbing cloth as used in the measurement of the elongation of the rubbing cloth into a rectangle having a length of less than 1/2 of the outer circumference of the rotating roller. Produced. The two rubbing cloths are wound around the outer peripheral surface of the rotating roller at an equal interval with a double-sided adhesive tape so that the length of the rubbing cloth (L in FIG. 3) is parallel to the end face of the rotating roller. Produced. FIG. 8 shows a cross section of the rubbing roller manufactured in this example.

Except for using the rubbing roller as described above, the same manufacturing method as in Example 1 was used to change the cutting angle of the raw rubbing cloth (α in FIG. 3) and the amount of pile pushed in during rubbing. As shown in Table 6, nine types of samples were prepared.

[0042]

[Table 6]

For each of the prepared samples, an electric signal is applied between the electrodes at a voltage equal to or higher than the threshold value of the liquid crystal, and the resulting display unevenness (streak-like unevenness a1, b1 and band-like unevenness a shown in FIG. 11).
Table 2 shows the results of observation of 2, b2 and unevenness at equal intervals shown in FIG. However, evaluation criteria are the same as in the first embodiment.

[0044]

[Table 7]

[0045]

According to the method of manufacturing a liquid crystal display device of the present invention, in the step of moving a pile raised from a rubbing cloth in a predetermined direction while contacting the surface of an alignment film formed on a substrate, By using a rubbing cloth whose tip is located behind the hair root of the pile with respect to the direction, it is possible to improve rubbing non-uniformity which causes display unevenness and improve display quality. , A liquid crystal display element excellent in the above can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic view of a rubbing cloth.

FIG. 2A is a cross-sectional view of a rubbing cloth used in a conventional manufacturing method. (B) It is sectional drawing of the rubbing cloth used in the manufacturing method of this invention.

FIG. 3 is a view showing a method of cutting a rubbing cloth used in the production method of the present invention.

FIG. 4 is a view showing an arrangement of a rubbing roller and a substrate in a rubbing step in the manufacturing method of the present invention.

FIG. 5 is a bird's-eye view of the liquid crystal display element.

FIG. 6 is a sectional view of a liquid crystal display element.

FIG. 7 is a sectional view of a rubbing cloth used in an example of the present invention.

FIG. 8 is a sectional view showing a rubbing roller used in Embodiment 3 of the present invention.

FIG. 9 is a view showing an arrangement of a rubbing roller and a substrate in a rubbing step in a conventional manufacturing method.

FIG. 10 is a diagram illustrating display unevenness that occurs in a liquid crystal display element manufactured by a conventional manufacturing method.

FIG. 11 is a diagram illustrating display unevenness that occurs in a liquid crystal display element manufactured by a conventional manufacturing method.

FIG. 12 is a diagram illustrating display unevenness that occurs in a liquid crystal display element manufactured by a conventional manufacturing method.

[Explanation of symbols]

 Reference Signs List 1 rubbing roller 2 transparent substrate 3 warp yarn 4 weft yarn 5 pile 6 cutting die 7 resin 10a, 10b transparent substrate 11a, 11b transparent electrode 12a, 12b alignment film 13 sealing material 14 spacer 15 liquid crystal 16 retardation plate 17a, 17b deflection plate 18 liquid crystal Display element 20a, 20b Rubbing cloth a1, b1 Striped display unevenness a1, b2 Band-shaped display unevenness

Continued on the front page. (72) Inventor Naito Natsuki 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (11)

[Claims] 1. A process for controlling the alignment of liquid crystal molecules, in which a pile raised from a rubbing cloth is moved in a certain direction while being in contact with the surface of an alignment film formed on a substrate, so that the surface of the alignment film is adjusted. In a method for manufacturing a liquid crystal display element including a rubbing step, the rubbing cloth is
A method for manufacturing a liquid crystal display element, wherein the pile is raised so that the tip of the pile is located behind the root of the pile with respect to the direction. 2. The method according to claim 1, wherein the rubbing step is performed by rotating a rotating roller around which the rubbing cloth is wound while approaching a substrate that moves in a predetermined direction. . 3. The rubbing cloth, wherein the piles are arranged so as to form a row in at least one direction, such that a parallel direction of the piles is inclined with respect to a direction in which the rotating roller rotates. 3. The method according to claim 2, wherein the liquid crystal display element is wound around the rotating roller. 4. The method according to claim 3, wherein an angle between the direction in which the piles are arranged in parallel and the direction in which the rotating roller rotates is 3 ° to 45 °. 5. The liquid crystal display device according to claim 2, wherein a rotation axis of the rotation roller is inclined with respect to a direction perpendicular to a direction in which the substrate moves. Production method. 6. The method according to claim 5, wherein an angle formed between a rotation axis of the rotation roller and a direction perpendicular to a direction in which the substrate moves is less than 20 °. 7. An angle formed between a rotation axis of the rotation roller and a direction perpendicular to a direction in which the substrate moves is 20 ° to 20 °.
The method according to claim 5, wherein the angle is 90 °. 8. The rubbing cloth has a characteristic that an elongation percentage when applying a tensile stress of 1 kg / cm in a direction corresponding to a direction in which the rotating roller rotates is 10% or less. 8. The method for manufacturing a liquid crystal display device according to any one of items 7. 9. A method in which n rubbing cloths having a dimension in a direction corresponding to a direction in which the rotating roller rotates is less than 1 / n of a circumference of the rotating roller are wound around the rotating roller at equal intervals. A method for manufacturing a liquid crystal display device according to any one of claims 2 to 8, wherein: Where n is
It is a natural number of 2 or more. 10. The rubbing step is such that the shortest distance between the root of the pile and the surface of the alignment film is such that the length of the pile is P (mm) and the inclination angle of the pile is θ.
(°), it is more than 0 than the value represented by Pcosθ.
The method for manufacturing a liquid crystal display element according to claim 2, wherein the method is performed in a state of being smaller by 2 to 0.7 mm. However, the inclination angle θ of the pile is an angle formed by the pile and a normal to the outer peripheral surface of the rotating roller passing through the root of the pile. 11. The method for manufacturing a liquid crystal display device according to claim 2, wherein one substrate is rubbed a plurality of times in the same direction.