JP2003255351A - Substrate for liquid crystal display, method for its rubbing processing and liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce long streak irregularity of image display by contrivance of a rubbing processing method by clearing up causal association between the irregularity of image display and the rubbing processing method. <P>SOLUTION: The streak irregularity is reduced in the following way. A rubbing processing is performed by making angles from ±1° to ±10° except 0° to the side direction of orientational film printing. An angle formed by the parallel transfer direction of a substrate and a rotational axis of a rubbing roller is set to be from ±30° to ±60°. Parallel transfer speed of the substrate/the number of rotations is defined to be equal to or less than 0.5 mm/rotation. Contact width between the substrate and cloth is defined to be from 10 mm to 18 mm. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display substrate used in a liquid crystal display device, a rubbing method for the same, and a liquid crystal display device manufactured using the substrate produced by the method.

[0002]

2. Description of the Related Art At present, liquid crystal display devices are widely used for screen display of personal computers, car navigation systems, monitors and TVs. As the alignment mode of liquid crystal used for these liquid crystal displays, TN type alignment mode and STN type alignment mode using nematic liquid crystal are often used, but they have drawbacks such as slow response and narrow viewing angle. Moreover, in recent years, a liquid crystal display device of an IPS (horizontal plane drive) display mode driven by a lateral electric field has been put into practical use as a display mode having an excellent viewing angle, but it has a problem in response speed and aperture ratio. In addition, although there are display modes such as a ferroelectric liquid crystal having a fast response speed and a wide viewing angle, there are problems in shock resistance and temperature characteristics. Recently, an optical compensation (OCB) type alignment mode has attracted attention as a display mode with excellent high-speed response and a wide viewing angle for use in video equipment, and is under active development.

FIG. 6 shows a sectional view of an OCB type liquid crystal display panel 100. In FIG. 6, on the counter substrate 52,
A color filter 57, a (translucent conductive) electrode 54, and an alignment film 56 are laminated and formed, and a counter electrode (transparent conductive electrode) 53 and an alignment film 55 are sequentially formed on the substrate 51. , 52 between which a liquid crystal layer 111 is interposed, and a retardation plate 59 for optical compensation is provided outside the substrate 51.
A polarizing plate 58 is arranged, and the retardation plate 59, the polarizing plate 58, and the backlight 11 for the light source are provided outside the counter substrate 52.
In this configuration, 0 is arranged. This OCB type mode is shown in FIG.
As shown in (a), it is a cross-sectional view of a liquid crystal layer in which splay alignment is performed by rubbing alignment films 55 and 56 on both substrates 51 and 52 facing each other for a liquid crystal display panel in a parallel direction. In the splay alignment state, the liquid crystal molecules of the liquid crystal layer 111 near the surfaces of the alignment films 55 and 56 have a high tilt angle (5 ° to 12 °) with respect to the surfaces of the alignment films 55 and 56. That is, both the substrates 51 and 52
A state in which liquid crystal molecules of the liquid crystal layer 111 are transferred from the splay alignment to the bend alignment or the bend alignment including the twist alignment as shown in FIG. 6B by applying a voltage between the electrodes 53 and 54 of FIG. 6 (c) has a bend orientation state. Then, FIG. 6A and FIG.
6 is a state (commonly referred to as white display) in which the transmittance (luminance) of the light from the backlight 110 is high when a low voltage is applied.
(C) shows a state (commonly called black display) in which the transmittance (luminance) is low when a high voltage is applied, and image display is performed by the white display, the black display and the black and white intermediate display.

In order to obtain not only the TN type alignment mode, the STN type alignment mode, the ferroelectric type alignment mode, and the antiferroelectric type alignment mode but also the OCB type alignment mode, coating and forming on both substrates 51 and 52 are performed. The alignment films 55, 56 and the like are processed by the above-described method of rubbing.

FIG. 7 schematically shows a process of rotating the rayon cloth 63 wound around the rubbing roller 62 in contact with the counter substrate 52 so as to translate the counter substrate 52 mounted on the stage 61 in the x direction 65 and perform a rubbing process. FIG.

FIG. 8 is a plan view for clarifying the relationship between the conventional rubbing direction 75 and the sides AB, BC, CD, DA of the counter substrate 52. An elongated electrode 72 corresponding to the electrode 54 is formed in parallel with the side AB of the counter substrate 52. In FIG. 8, a rubbing direction 75 indicated by an arrow y is a plan view of the rubbing roller rotation direction 60 (direction perpendicular to the rubbing roller rotation axis (w direction) 66), and the rubbing angle θ1 is the above-mentioned value. Rubbing direction 75 (arrow y
Direction) and the u direction 76 of the side AB of the substrate.

The liquid crystal display panel 100 described in FIG. 6 is constructed by using the substrate subjected to the rubbing treatment described above, and a video screen is displayed when a voltage (video signal) is externally applied to the liquid crystal display panel 100. Is displayed. The display uniformity of the display screen is sensitively affected by conditions such as a translational movement direction of the substrate, a translational movement speed, a rotation speed of the rubbing roller, a rotation direction of the rubbing roller and a plunge angle to the substrate side during the rubbing process. Depending on the rubbing conditions, streak-like display unevenness, which is commonly called a vertical streak, occurs. Regarding the streaky unevenness and the rubbing condition, Japanese Patent Laid-Open No. 10-18636
As disclosed in Japanese Patent Laid-Open No. 4 and Japanese Patent Laid-Open No. 10-268311, the above-mentioned prior examples relate to the TN and STN orientation modes, the translational movement direction of the substrate, the translational movement speed, the rotation speed of the rubbing roller, and the rotation direction of the rubbing roller. And the conditions depending on the plunge angle to the side of the substrate.

That is, in Japanese Patent Laid-Open No. 10-186364 and Japanese Patent Laid-Open No. 10-268311, the rubbing process in the case of having a high pretilt angle peculiar to the OCB mode, the rotation speed of the rubbing roller and the substrate translation speed are described. Not disclosed. Regarding the flatness of the alignment film surface, for example, TFTs (not shown) are formed in a matrix on the electrodes 54 of the counter substrate 52 of FIG. 6, and the TFTs include electrode materials, insulating materials, semiconductor materials, and Since it is made of a protective film material, the surfaces of the alignment films 55 and 56 applied on the electrodes including the TFTs are not flat, but are uneven when viewed from liquid crystal molecules.

The OCB type orientation is a splay orientation as described above, and compared with a low pretilt angle when twist orientation such as TN type or STN type orientation mode is adopted,
The OCB type mode requires a high pretilt angle when splay alignment is performed. Not only the TN type and STN type,
The OCB type alignment having a high pretilt angle is also aligned by the rubbing treatment on the surfaces of the alignment films 55 and 56 having the uneven shape, but the splay alignment is present with a certain dispersion (variation) in manufacturing. However, the OCB type mode having a high pretilt angle has a larger change in the pretilt angle with respect to dispersion. The magnitude of the change in the pretilt angle is a main factor of the vertical stripe-shaped display unevenness. That is,
In the image display on the OCB type liquid crystal display device, since the change of the pretilt angle is large as described above, the change rate of the transmittance with respect to the change of the voltage becomes large in the halftone display.
The display unevenness becomes more remarkable as compared with the twist orientation mode.

[0010]

In the conventional liquid crystal alignment process as described above, the alignment film 56 in FIG.
Of the alignment film edge 64 near the edge 67 of the alignment film and the terminal surface of the electrode 54 at the edge of the counter substrate 52 in order to form a coating by transfer printing on a portion excluding the electrode terminals near the edge of the counter substrate 52. And that there is a step between the alignment film edge portion 67 and the alignment film edge portion 64 in the vicinity of the alignment film edge portion 67, and the film thickness is formed to be thick. Furthermore, when the conventional rubbing process is seen from the plan view, The processing is performed by a method in which the side direction AB of the substrate moves in parallel.

As described above, during the rubbing process, the counter substrate 52 moves in the arrow x direction 65, so that the rubbing roller 62, which is rotating at a constant high speed, comes into contact with the alignment film end portion 64 so as to rush into it. It will be. In this case, peeling of the alignment film end portion 64 easily occurs near the alignment film end portion 67 near the step portion, and the peeled alignment film adheres to the tip end of the rayon cloth 63 wound around the rubbing roller 62. The adhered alignment film is redeposited on the alignment film end portion 67 or the alignment film corresponding to the display region 68, or the alignment film 56 on the substrate is rubbed while being attached to the tip of the rayon cloth 63. A difference occurs in comparison with the condition of rubbing at the tip of the rayon cloth 63 which is not attached. If there is a difference in the rubbing condition depending on the display area,
When liquid crystal is injected, a difference occurs in the alignment of liquid crystal molecules.
This difference in the orientation of the liquid crystal molecules is caused by the difference in the pretilt angle of the liquid crystal molecules, and particularly in the OCB type mode because of the high pretilt angle as described above, it tends to appear as display unevenness in the liquid crystal display image. FIG. 9 shows long streaky irregularities 81 with equal intervals which are generated due to the above factors.

The long streak 81 is shown in FIG.
The positions 1, 2, and 3 on the rayon cloth 63 wound around the rubbing roller 62 are transferred to the positions 1, 2, and 3 on the counter substrate 52 while rotating, when performing the rubbing treatment operation described above. Show. That is, when the rubbing roller 62 at position 1 rushes into the edge (64 in FIG. 7) of the alignment film near the edge of the substrate (67 in FIG. 7), if the alignment film peels off and adheres to the tip of the cloth, Position 1 is rubbing roller 62
Is rotated, and the portion corresponding to the position 1 on the substrate is rubbed as the counter substrate 52 moves in translation. This rubbing process operation similarly occurs at the positions 2 and 3, so that a long vertical stripe-shaped display unevenness 9 as shown in FIG.
1 occurs. The vertical stripe-shaped unevenness 91 shown in FIG. 10 cannot be confirmed when the rubbing process is performed, but is visible when the image is displayed on the display device.

Also, when the alignment film 56 is formed by the transfer printing method in FIG. 10, the side AB,
Near the board edges on the sides BC, CD, DA (67 in FIG. 7)
Since the edge portion (64 in FIG. 7) of the alignment film formed in 1) has a large film thickness, it is easily peeled off during the rubbing process. When the rubbing process is performed in the rubbing direction and the substrate translational movement direction as shown in FIG. 10, peeling is likely to occur on the sides AB and DA of the four sides of the counter substrate 52. This is based on FIG. 10 or FIG.
The ends of sides AB and DA are made of rayon cloth 63 when rubbing.
Is a side that rushes into the substrate while rotating, so side B
This is because the rotational torque (impact force) applied to the alignment film by the tip of the rayon cloth is smaller at the end portions of C and side CD than the side of the rayon cloth that is farther away from the substrate.

The present invention solves the problem that the alignment film 56 is easily peeled off on the side AB and the side DA as described above, and the alignment film edge portion 67 generated during the rubbing treatment is generated.
A method for rubbing a substrate for a liquid crystal display, which can reduce peeling and re-adhesion of the film and occurrence of vertical stripe unevenness 91, and improve display uniformity of a liquid crystal display, and a liquid crystal display device using the substrate subjected to the rubbing treatment. It is intended to be provided.

[0015]

As a first invention for achieving the above object, for example, in an OCB type liquid crystal display device, a substrate for liquid crystal display used for a parallel alignment type liquid crystal display device not twist-aligned is used. A rubbing treatment method, wherein when rubbing the surface of a high pretilt angle alignment film formed on the surface of a flat rectangular substrate, the rubbing roller is formed between a direction perpendicular to the rotation axis of the rubbing roller and one side of the flat rectangular substrate. It is a method of rubbing the flat plate-shaped rectangular substrate while keeping the angle from ± 1 ° to ± 10 ° except 0 °.

A second invention is a method of rubbing a liquid crystal display substrate used in a parallel alignment type liquid crystal display device which is not twist-aligned, wherein the surface of an alignment film formed on the surface of a flat rectangular substrate. When rubbing, the value of (translational moving speed / rotation number) of the flat plate-shaped rectangular substrate was 0.
It is a method for rubbing a liquid crystal display substrate, which is characterized by being 5 mm / rotation or less.

As a third invention, in the second invention, the angle formed by the translational movement direction of the flat rectangular substrate and the rotation axis direction of the rubbing roller is in the range of ± 30 ° to ± 60 °. Is a method of rubbing a liquid crystal display substrate.

As a fourth invention, in the first or second invention, the contact width between the alignment film formed on the surface of the flat plate-shaped rectangular substrate and the rubbing cloth for rubbing the alignment film is changed from approximately 10 mm to 18 mm. A method of rubbing the liquid crystal display substrate, which comprises holding and rubbing the flat plate-shaped rectangular substrate.

That is, in the rubbing process of the alignment mode in which a high pretilt angle peculiar to the OCB type mode is required, the edge of the cloth is rubbed at an angle θ with respect to the rubbing direction so that the tip of the cloth is rubbed. This is a method of dispersing the rotational torque when the end portion of the upper alignment film is rushed. Then, from the results of (Table 1), when the stripe pitches generated at equal intervals become wider, the stripes are easily visible. Therefore, the stripe pitch is approximately equal to the stripe width by a method of increasing the rotation speed and slowing the substrate translational movement speed. This is a way to make the lines hard to see. Then, the shape of the edge portion 67 of the alignment film 56 formed by transfer printing on the substrate is formed into a zigzag pattern (FIG. 5A) or a wavy pattern (FIG. 5B), whereby vertical stripes are generated. It was found that it was possible to reduce the amount and make it easier to see.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As for the reference numerals, the same reference numerals are used for the portions common to the drawings described above.

(Embodiment 1) FIG. 1 is a plan view showing a positional relationship between a counter substrate 52 and a rubbing roller 62 in a rubbing process according to the present invention. In FIG. 1, the counter substrate 52 on the stage is translated in the arrow x direction 65.
The angle formed by B is θ1, and the angle range of θ1 is 0.
It is a top view showing what was carried out so that it may become ± 10 from ± 1 ° excluding °. If rubbing is performed in parallel with the side of printing the alignment film, the alignment film on the side of the print end is easily peeled off. This is because printing unevenness occurs at the print edge and the print film is thick, and basically the print edge is easier to peel off than the central portion. In addition, the operation of rubbing the cloth on the surface of the alignment film is continuously performed in the rubbing direction, so that peeling easily occurs.

As described above, the distance at which the cloth contacts the substrate is equal to the contact width, and the alignment film is peeled and damaged by this distance. In FIG. 9, a side parallel to the rubbing direction, such as the side AB, has a contact width (for example, 15 mm) that is entirely in contact with the end portion of the alignment film, and thus is damaged over the entire contact width. Since there is only one point on the side AD that contacts the edge of the substrate, no peeling occurs.

In this way, peeling occurs from the side of the alignment film printing parallel to the rubbing direction. In order to solve this, it is effective to incline the rubbing direction and the direction of the side of printing the alignment film. According to the study by the present inventor, this inclination angle of 1 ° was sufficient. It is more preferable that the angle is 5 ° or more.

However, while printing is performed in parallel with the outline,
If the rubbing direction is simply tilted, the viewing angle characteristic becomes asymmetric in the left-right direction. Japanese Patent Application 2000-22
Like the 2273, the OCB type liquid crystal TV has been designed with the rubbing direction as the vertical direction and the brightness in the horizontal direction as important, but when the rubbing direction is tilted from the vertical direction, for example, an image viewed from the upper right and an upper left. There was a problem that the images viewed from looked different. In the study of the present invention, it was concluded that the maximum value in the rubbing direction should be 10 ° or less. Therefore, by setting the rubbing direction at an inclination angle of 1 ° or more and 10 ° or less from the side of the alignment film printing pattern, it was possible to suppress the occurrence of rubbing streaks and further maintain good viewing angle characteristics.

As a result of the above implementation, vertical streaks as shown in FIG. 9 were generated when θ1 was an angle of 0 °, but when implemented at an angle θ1 other than 0 °, it was as shown in FIG. The vertical streaks were reduced and a display screen that was easy to see was obtained.

(Embodiment 2) FIG. 3 shows that the angle θ2 formed by the substrate translational movement direction (x direction) 65 and the rotation axis direction 66 of the rubbing roller is in the range of ± 30 ° to ± 60 °. FIG. At this time, the rotation speed of the rubbing roller was 600 rotations / minute, 1200 rotations / minute, and the translational movement speed was 10 mm / second and 20 mm.
/ Sec and 40 mm / sec. The pitch of streak unevenness generated under each condition is shown below (Table 1).

[0027]

[Table 1]

FIG. 4 is an enlarged cross-sectional view showing a state in which the alignment film 56 on the counter substrate 52 and the rayon cloth 63 of the rubbing roller 62 are in contact (contact between points G and H in the figure). In FIG. 4, the length of the bristles of the rayon cloth 63 wound around the rubbing roller 62 is about 1.6 mm, but since the cylinder diameter of the rubbing roller 62 has a curvature,
Approximately 10 mm to 18 mm when contacting the counter substrate 52
(15 mm in the figure) is set. This contact width 69 moves the stage 61 in the vertical direction (z
Direction) 70 to adjust. Contact width 6
The adjustment of 9 must be determined together with the rotation speed and the translational movement speed of the rubbing roller when the rubbing conditions are determined. That is, the contact width 69 being large means that the alignment film 56 is strongly pressed by the rayon cloth 63, so that the alignment film is likely to be peeled off (which is one of the factors of display unevenness), and the contact width 69 is small. This is because the rayon cloth 63 presses the alignment film 56 weakly, resulting in insufficient rubbing, and a weak alignment regulating force when aligning the liquid crystal molecules of the liquid crystal layer 111. The above (Table 1) was performed with a contact width of about 15 mm during the rubbing treatment.

Under the above-mentioned conditions, when the rubbing roller is rotated at 1200 rpm, and the angle θ2 is rubbed within a range of ± 1 ° to ± 10 ° except 0 ° with respect to 10 mm / sec, a streaky pitch is obtained. Since the width approaches the streak width substantially equivalently, streak unevenness is more difficult to see as compared with the other conditions in the first embodiment. This method can suppress the rubbing line of the vertical line even if the direction of the side of the alignment film printing and the rubbing direction are the same. Of course, the effect of reducing streak unevenness is also high if it also serves as the inclination in the rubbing direction in the first embodiment.

That is, from Table 1, if the value of (translational movement speed) / (number of rotations) is 0.5 mm / revolution, streaky unevenness is less likely to be seen.

(Embodiment 3) FIG. 4 shows the rubbing treatment of the substrate with the contact width between the rubbing cloth and the surface of the alignment film kept at about 10 mm to 18 mm (15 mm in the figure). . FIG. 2 shows an image display in which long streak unevenness is reduced. The rubbing method of the present invention is based on OCB.
It is particularly effective in reducing display unevenness that tends to occur in an alignment mode having a high pretilt angle such as a liquid crystal display, but other alignment modes such as an IPS liquid crystal display, a ferroelectric liquid crystal display and an anti-ferroelectric display by rubbing treatment. It is possible to reduce display unevenness even for a dielectric liquid crystal display.

(Fourth Embodiment) In the fourth embodiment, the problem of rubbing streaks is solved by changing the shape of the alignment film printing. The present invention reduces the peeling phenomenon of the alignment film by displacing the rubbing direction with the printing side of the alignment film, and realizes quality improvement and yield improvement. In the fourth embodiment, this is realized by the alignment film printing pattern.

FIG. 5 shows a zigzag pattern 67 for the shape of the vicinity of the end portion 67 of the alignment film 56 formed by transfer printing on the counter substrate 52.
FIG. 6 is a plan view in which 1 or corrugated pattern 672 is formed. It is desirable that the width of the zigzag pattern or the corrugated pattern is wide, but a width of about 1 to 2 mm is realistic from the viewpoint of the process. Further, the zigzag pitch is ideal if it is equal to or larger than the contact width of rubbing, but in reality, it is preferably equal to or larger than half the contact width. Note that if it is 2 mm or more, there is an effect.

Further, the inclination angle of the side of this zigzag pattern is effectively 10 ° or more and 45 ° or less, and preferably 15 ° or more and 30 ° or less (exaggerated in FIG. 5). However, the slope near the rubbing direction was actually good).

Although the zigzag pattern is effective as the shape, it may have a sawtooth shape or an arc shape.

[0036]

As described above, according to the present invention, when rubbing the surface of the alignment film, the angle between the direction perpendicular to the rotation axis of the rubbing roller and one side of the rectangular substrate is ± 1 ° except 0 °.
It is possible to make the streak pitch substantially equal to the streak width by keeping the value of ± 10 ° from or, or by rubbing the substrate with the value of substrate translational movement rate / rotation number of 0.5 mm / revolution or less, It was found that in the OCB type liquid crystal display screen having a high pretilt angle, it was effective in reducing the occurrence of streak unevenness. Therefore, the present invention has a great industrial advantage in producing a display screen for video equipment such as a TV that requires high-quality display.

[Brief description of drawings]

FIG. 1 is a plan view of an apparatus for carrying out a rubbing method according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an image display in which long streaky irregularities are reduced.

FIG. 3 is a plan view of an apparatus for carrying out a rubbing method according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a contact width between a substrate and a rubbing cloth.

FIG. 5 (a) is an alignment film with a zigzag edge. (B) Alignment film diagram with wavy edge

FIG. 6 is a sectional view showing the configuration of an OCB type liquid crystal display panel.

FIG. 7 is a cross-sectional view showing a state of a rubbing process.

FIG. 8 is a plan view of a conventional rubbing processing apparatus.

FIG. 9 is a diagram showing an image display in which long streak-like unevenness has occurred.

FIG. 10 is a plan view for considering the relationship between long streaky irregularities and rubbing.

[Explanation of symbols]

1,2,3 position 51 (flat plate) substrate 52 (Flat plate square) counter substrate 53 Counter electrode 54 electrodes 55,56 Alignment film 57 color filters 58 Polarizing plate 59 Phase plate 60 Rotation direction of rubbing roller 61 stage 62 rubbing roller 63 rayon cloth 64 Edge of alignment film 65 Substrate translational movement direction (x direction) 66 Rubbing roller rotation axis direction (w direction) 67 Near the edge of the alignment film 68 Display area 69 contact width 70 Vertical direction (z direction) 72 Long electrode 75 Rubbing direction (y direction) 76 Direction parallel to substrate side AB (u direction) 81 Long streaky spots 91 Vertical stripe unevenness 100 LCD display panel 110 backlight 111 Liquid crystal layer 671 Zigzag pattern alignment film 672 Corrugated pattern alignment film

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshinori Yamamoto             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Akino Shioda             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Norihisa Maeda             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 2H090 KA04 KA05 KA07 KA08 LA01                       LA08 LA09 LA16 MA02 MA08                       MA10 MA12 MB01

Claims (12)

[Claims] 1. A method for rubbing a liquid crystal display substrate used for a parallel alignment type liquid crystal display device, which is not twist-aligned, wherein a surface of a high pretilt angle alignment film formed on the surface of a flat rectangular substrate is used. When rubbing, the flat rectangular substrate is rubbed while the angle between the direction perpendicular to the rotation axis of the rubbing roller and one side of the flat rectangular substrate is held within ± 1 ° to ± 10 ° except 0 °. A method for rubbing a substrate for a liquid crystal display, which is characterized in that: 2. A method of rubbing a liquid crystal display substrate used in a parallel alignment type liquid crystal display device, which is not twist-aligned, wherein the surface of an alignment film formed on the surface of a flat rectangular substrate is rubbed. In addition, the method of rubbing a liquid crystal display substrate, wherein the value of (translational moving speed / rotation speed) of the flat plate-shaped rectangular substrate is 0.5 mm / rotation or less. 3. The angle formed by the translational movement direction of the flat plate-shaped rectangular substrate and the rotation axis direction of the rubbing roller is from ± 30 ° to ± 6.
The method of rubbing a liquid crystal display substrate according to claim 2, wherein the rubbing treatment is performed in the range of 0 °. 4. The flat rectangular substrate is rubbed while the contact width between the alignment film formed on the surface of the flat rectangular substrate and a rubbing cloth for rubbing the alignment film is maintained at about 10 mm to 18 mm. The method of rubbing a substrate for liquid crystal display according to claim 1 or 2. 5. A liquid crystal display device manufactured by using the substrate for liquid crystal display that has been rubbed according to any one of claims 1 to 4. 6. The liquid crystal display device according to claim 5, wherein the liquid crystal display device is of OCB type, IPS type, ferroelectric type or antiferroelectric type. 7. A flat substrate for liquid crystal display, which is not twist-aligned and is used for a parallel alignment liquid crystal display device, wherein an end shape of a high pretilt angle alignment film formed by printing on the substrate is A liquid crystal display substrate having a zigzag shape or a wavy shape. 8. The liquid crystal display substrate according to claim 7, wherein the pitch of the zigzag shape or the wavy shape is approximately 2 mm or more. 9. The zigzag or corrugated side is substantially the same as the rubbing direction.
The liquid crystal display substrate described in. 10. The liquid crystal display substrate according to claim 7, wherein the zigzag inclination angle is 10 ° or more and 45 ° or less. 11. The liquid crystal display substrate according to claim 7, wherein the zigzag inclination angle is 15 ° or more and 30 ° or less. 12. A liquid crystal display device using the substrate for liquid crystal display according to claim 7.