JPH1184384A - Liquid crystal olientation treatment and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal olientation treatment method capable of preventing the peeling at an oliented layer end and enhancing the display uniformity of a liquid crystal display by controlling the positional relation between a roller and a substrate and the number of revolutions of the roller at the time of a rubbing treatment. SOLUTION: On the oliented layer end 16 out of the oliented layer end 16 and image display region 18 on the oliented layer 13 formed on the substrate 10, a rubbing treatment is not executed by maintaining a specified spacing between the roller 15 and the oliented layer 13. In the image display region 18, the rubbing is executed by moving a stage 17 in an arrow c direction, thereby bringing the cloth 14 of the high-speed revolving roller 15 into contact with the oliented layer 13. As a result, the cloth 14 of the roller 15 is not in contact with the oliented layer 13 at the oliented layer end 16 and, therefore, the peeling of the oliented layer 13 may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rubbing process for a liquid crystal panel of a liquid crystal display device.

[0002]

2. Description of the Related Art Recently, liquid crystal displays have been widely used as screen displays for personal computers, word processors, car navigation systems, monitors, and the like. As a mode of a liquid crystal panel used for these liquid crystal displays, a mode of a TN type alignment or an STN type alignment is most often used.

In order to obtain the TN type or STN type alignment mode, a method of rubbing an alignment film applied on a substrate with a rubbing cloth is used. FIG. 2 is a cross-sectional view showing the relationship between a liquid crystal substrate and a roller of a rubbing device in a conventional rubbing process.

An alignment film 13 is formed on a substrate 10 with a color filter 11 and an electrode terminal 12 interposed therebetween. Characters R, B, and G of the color filter 11 are red, black,
It shows a green color tone, and a light shielding film (black matrix) 11a is formed between each color tone.

[0005] A rayon cloth 14 is wound around the roller 15. The stage 17 is horizontally moved in the direction of the arrow b while the position of the roller 15 is fixed and the roller 17 is constantly rotated in the direction of the arrow a. As the horizontal movement progresses, roller 1
5 is in contact with the alignment film 13, and in this state, the roller 1
Numeral 5 rubs the entire surface of the alignment film 13 while rotating. The liquid crystal panel is completed by holding a certain gap between the two substrates thus subjected to the alignment treatment, injecting liquid crystal into the gap, and sealing.

[0006]

However, in the conventional liquid crystal alignment processing method as described above, the alignment film 13 is formed by applying a printing method to a portion excluding the electrode terminals 12 at the end of the substrate 10. There is a step between the surface of the alignment film 13 at the end 16 of the alignment film and the surface of the electrode terminal 12 at the end of the substrate 10.

During the rubbing process, the substrate 10
In this case, the alignment film 13 contacts the roller 15 rotating at a constant high speed. in this case,
The alignment film 13 is easily peeled off at the edge 16 of the alignment film near the step, and there is a problem that the peeled alignment film is re-attached to the vicinity of the edge 16 of the alignment film or to the display area 18.

The gap between liquid crystal panels is typically about 5 microns, and must be kept below about 0.05 microns in order to obtain a uniform liquid crystal display. The film thickness of the alignment film 13 is about 0.5.
Since the alignment film is 1 micron, when the alignment film peeled off as described above is re-adhered, unevenness in the gap between the upper and lower substrates is generated at that portion. Unevenness occurs.

The present invention solves the above problems,
By controlling the positional relationship between the roller and the substrate during the rubbing process and the number of rotations of the roller, it is possible to prevent peeling of the end portion of the alignment film and to improve the display uniformity of the liquid crystal display, and to use the method. It is an object to provide a liquid crystal display device.

[0010]

In order to achieve the above object, a first liquid crystal alignment processing method of the present invention is to rotate a roller around which a cloth is wound on an alignment film formed on a substrate. A liquid crystal alignment treatment method for rubbing the alignment film, wherein the end portion of the alignment film and the image display region are not rubbed, and the image display region is rubbed. And

According to the liquid crystal alignment processing method as described above,
Since the roller does not contact the alignment film at the edge of the alignment film, it is possible to prevent the separation of the alignment film at the edge of the alignment film. In the first liquid crystal alignment processing method, at an end of the alignment film,
It is preferable that the alignment film and the roller are brought into contact with each other by keeping a space between the alignment film and the roller and moving the substrate in a vertical direction in an image display area of the alignment film.

Next, a second liquid crystal alignment processing method according to the present invention is directed to a liquid crystal alignment processing for rubbing the alignment film by rotating a roller around which a cloth is wound on the alignment film formed on the substrate. The method, wherein the end of the alignment film and the image display area have a roller rotation speed of 500.
A rubbing process is performed at a speed of not more than rpm, and the rubbing process is performed in a range of 1200 to 1500 rpm in the image display area.

According to the liquid crystal alignment processing method as described above,
Since the edge of the alignment film is rubbed at a low speed, peeling of the alignment film at the edge of the alignment film can be prevented. Next, the liquid crystal display device of the present invention is characterized by being formed by using each of the liquid crystal alignment treatment methods.

According to the liquid crystal display device as described above, since the peeling of the alignment film at the edge of the alignment film can be prevented, the unevenness in the gap between the upper and lower substrates due to the reattachment of the alignment film and the unevenness in the alignment of the liquid crystal can be prevented. it can.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a sectional view showing a relationship between a liquid crystal substrate and a roller of a rubbing device in a rubbing process of the present invention. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof is omitted.

FIG. 1A shows the case where the lower end of the roller 15 around which the cloth 14 made of rayon is wound is on the alignment film end 16 by moving the stage 17 horizontally in the direction of arrow b. ing. The rollers 15 are 1200 to 15
Although it rotates in the direction of the arrow a at a rotation speed in the range of 00 rpm, a certain interval is secured between the roller 15 and the alignment film 13, so that the cloth 14 of the roller 15
Not in contact with For this reason, peeling of the alignment film 13 at the alignment film end 16 can be prevented.

Further, when the stage 17 is moved horizontally in the direction of arrow b while the position of the roller 15 is fixed,
As shown in FIG. 2B, the position of the lower end of the roller 15 is on the display area 18. In this state, the cloth 14 of the roller 15 is in contact with the alignment film 13. This contact can be made by moving the stage 17 in the vertical direction (the direction of arrow c).

If the horizontal movement of the stage 17 in the direction of the arrow b is continued, the display area 18 can be rubbed. That is, in the present embodiment, the cloth 14 of the roller 15 is
At the alignment film end 16, the display region 1 is not in contact with the alignment film 13.
In No. 8, it comes into contact with the alignment film 13.

The start position of contact between the roller 15 and the alignment film 13 and the number of rotations of the roller 15 can be controlled by a control program for the rubbing device. (Embodiment 2) In Embodiment 2, unlike Embodiment 1, the cloth 14 of the roller 15 is in contact with the alignment film 13 even on the alignment film end 16. In this embodiment, the cloth 14 of the roller 15 is used.
Is in contact with the alignment film 13 at the edge 16 of the alignment film, the roller 15 is rotated at a low speed so that the cloth 14
It rotates at high speed in the state where it is in contact with.

The number of rotations of the roller 15 is preferably 500 rpm or less when the cloth 14 is in contact with the edge 16 of the alignment film, and is in the range of 1200 to 1500 rpm when the cloth 14 is in contact with the display area 18. Is preferred.

The cloth 14 has an alignment film 1 at an end 16 of the alignment film.
However, since the roller 15 rotates at a low speed, peeling of the alignment film can be prevented. Switching from low-speed rotation to high-speed rotation of the roller 15, the number of rotations of the roller 15, and the like can be controlled by a program for controlling the rubbing device.

According to the liquid crystal alignment treatment methods of Embodiments 1 and 2 described above, the peeling of the alignment film 13 at the edge of the alignment film can be prevented. It is possible to prevent unevenness in the gap between the substrates and unevenness in the alignment of the liquid crystal. Therefore, it is also useful as an alignment processing method for improving the display uniformity of a large-screen liquid crystal display device expected in the market such as a terminal monitor or a flat-screen TV in the future.

[0023]

As described above, according to the liquid crystal alignment treatment method of the present invention, the separation of the alignment film at the edge of the alignment film is maintained by maintaining the interval between the alignment film and the roller at the edge of the alignment film. Can be prevented.

Further, by performing a rubbing process at a low speed rotation at the edge of the alignment film, the peeling of the alignment film at the edge of the alignment film can be prevented. Further, the liquid crystal display device of the present invention can prevent the occurrence of unevenness in the gap between the upper and lower substrates and unevenness in the alignment of the liquid crystal, and is therefore excellent in display uniformity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a relationship between a liquid crystal substrate and a roller of a rubbing device in a rubbing process of the present invention.

FIG. 2 is a cross-sectional view of a relationship between a liquid crystal substrate and rollers of a rubbing device in a conventional rubbing process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 11 Color filter 11a Light shielding film 12 Electrode terminal 13 Alignment film 14 Cloth 15 Roller 16 Alignment film end 17 Stage 18 Image display area

Claims (4)

[Claims] 1. A liquid crystal alignment processing method for rubbing an alignment film formed on a substrate by rotating a roller on which a cloth is wound, the edge of the alignment film and an image display. A liquid crystal alignment processing method, wherein a rubbing process is performed on the image display region without performing a rubbing process on the end portion of the region. 2. An end portion of the alignment film, wherein a gap is maintained between the alignment film and the roller, and a substrate is vertically moved in an image display area of the alignment film, so that the alignment film and the roller are moved. The liquid crystal alignment treatment method according to claim 1, wherein the liquid crystal alignment treatment is performed by contacting the roller. 3. A liquid crystal alignment processing method for rubbing an alignment film formed on a substrate by rotating a roller around which a cloth is wound, wherein an edge of the alignment film and an image display are displayed. A liquid crystal alignment processing method, wherein a rubbing process is performed on the end portion at a roller rotation speed of 500 rpm or less, and a rubbing process is performed on the image display region at a roller rotation speed of 1200 to 1500 rpm. 4. A liquid crystal display device formed by using the liquid crystal alignment processing method according to claim 1.