JP2011107487A - Method of manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubbing process to make the pre-tilt angle small. <P>SOLUTION: The surface of an alignment film 12 is rubbed by rubbing cloth 14 wound on a roller 10 while the alignment film 12 is moved relatively with respect to a rotating roller 10. The rubbing process is performed so that the rubbing direction of the alignment film 12 by the rubbing cloth 14 is opposite to the moving direction of the alignment film 12, then is performed so that the rubbing direction of the alignment film 12 by the rubbing cloth 14 is the same as the moving direction of the alignment film 12. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a liquid crystal display device.

  In the manufacturing process of a liquid crystal display device, a rubbing process is performed in order to align liquid crystal molecules in a certain direction after forming an alignment film (see Patent Document 1). It is important that the rubbing process is performed so as to adjust the angle (pretilt angle) between the major axis direction of the liquid crystal molecules and the substrate.

JP 2000-275743 A

  The pretilt angle differs depending on the liquid crystal driving method, and it may be required to reduce the pretilt angle. However, in the conventional rubbing process, the pretilt angle is increased and the display quality is lowered.

  An object of this invention is to perform a rubbing process so that a pretilt angle may become small.

  (1) In the method for manufacturing a liquid crystal display device according to the present invention, a rubbing step of rubbing the surface of the alignment film with a rubbing cloth wound around the roller while moving the alignment film relative to a rotating roller. The rubbing step is performed such that the rubbing cloth rubs the alignment film in a direction opposite to the moving direction of the alignment film, and then the rubbing cloth rubs the alignment film in the direction of the alignment film. The moving direction is the same as the moving direction. According to the present invention, it has been clarified through experiments by the inventors that the pretilt angle is reduced.

  (2) In the method of manufacturing a liquid crystal display device according to (1), the roller includes a first roller, and a second roller positioned ahead of the first roller in the moving direction of the alignment film. The rubbing cloth is wound around each of the first roller and the second roller, and the rotation direction of the first roller and the side on the side where the first roller and the second roller face the alignment film The moving direction of the alignment film is opposite, and the rotation direction of the second roller and the moving direction of the alignment film may be the same.

  (3) In the method for manufacturing a liquid crystal display device according to (2), the pressing amount of the rubbing cloth wound around the second roller with respect to the alignment film is the amount of the rubbing cloth wound around the first roller. It may be characterized by being larger than the amount of pressing into the alignment film.

  (4) In the method of manufacturing a liquid crystal display device described in (2) or (3), the rotation speed of the second roller may be larger than the rotation speed of the first roller.

  (5) In the method of manufacturing a liquid crystal display device according to (1), the first time so that a direction in which the rubbing cloth rubs the alignment film is opposite to a moving direction of the alignment film by the roller. After performing the rubbing, the second rubbing may be performed by the roller so that the rubbing cloth rubs the alignment film in the same direction as the movement direction of the alignment film.

  (6) In the method for manufacturing a liquid crystal display device according to (5), the amount of pressing of the rubbing cloth with respect to the alignment film in the second rubbing is the amount of the rubbing cloth in the first rubbing. It may be characterized by being larger than the amount of pressing into the alignment film.

  (7) In the method for manufacturing a liquid crystal display device according to (5) or (6), the number of rotations of the roller in the second rubbing is the number of rotations of the roller in the first rubbing. It may be characterized by being larger.

It is a figure explaining the manufacturing method of the liquid crystal display device which concerns on embodiment of this invention. It is a figure explaining the modification of the manufacturing method of the liquid crystal display device which concerns on embodiment of this invention. It is a figure explaining the modification of the manufacturing method of the liquid crystal display device which concerns on embodiment of this invention. It is a figure explaining the experimental process to which the conventional rubbing method is applied. It is a figure explaining the experimental process to which this embodiment is applied.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating a method for manufacturing a liquid crystal display device according to an embodiment of the present invention. In the present embodiment, the surface of the alignment film 12 is rubbed with a rubbing cloth 14 wound around the roller 10 while the alignment film 12 is moved relative to the rotating roller 10. The alignment film 12 is formed on a substrate 16 made of, for example, glass. The substrate 16 may be a TFT substrate on which a thin film transistor is formed, or a CF substrate on which a color filter is formed. In the example of FIG. 1, the position of the roller 10 is fixed and the stage 18 on which the substrate 16 is placed is moved. However, the roller 10 may be moved without moving the stage 18.

  The roller 10 includes a first roller 20 and a second roller 22 positioned in front of the first roller 20 in the moving direction of the alignment film 12. A rubbing cloth 14 is wound around each of the first roller 20 and the second roller 22. On the side where the first roller 20 and the second roller 22 face the alignment film 12, the rotation direction of the first roller 20 and the movement direction of the alignment film 12 are opposite, and the rotation direction of the second roller 22 and the alignment film 12 are opposite. The direction of movement is the same.

Push-in amount F ₂ of the alignment film 12 of the rubbing cloth 14 wound around the second roller 22 is larger than the push-in amount F ₁ for the alignment layer 12 of the rubbing cloth 14 wound around the first roller 20. The rotational speed of the second roller 22 is larger than the rotational speed of the first roller 20.

  The rubbing process is performed so that the rubbing cloth 14 rubs the alignment film 12 in a direction opposite to the moving direction of the alignment film 12, and then the rubbing cloth 14 rubs the alignment film 12 in the moving direction of the alignment film 12. Do the same. As a result, the inventors have found that rubbing can be performed so as to reduce the pretilt angle. The manufacturing method of the liquid crystal display device according to the embodiment of the present invention further includes a known process.

  2 and 3 are diagrams illustrating a modification of the method for manufacturing the liquid crystal display device according to the embodiment of the present invention.

  In this modified example, as shown in FIG. 2, the first rubbing is performed by the roller 110 so that the rubbing cloth 114 rubs the alignment film 12 in the opposite direction to the moving direction of the alignment film 12. After that, as shown in FIG. 3, the roller 110 shown in FIG. 2 is used again, so that the rubbing cloth 114 rubs the alignment film 12 in the same direction as the movement direction of the alignment film 12. Rubbing is performed once. That is, in this example, one roller 110 performs rubbing twice.

Push-in amount F ₂ of the alignment film 12 of the rubbing cloth 114 in the second round of rubbing as shown in FIG. 3 is greater than the push-in amount F ₁ for the alignment layer 12 of the rubbing cloth 114 in the first rubbing shown in FIG. 2 . The rotation speed of the roller 110 in the second rubbing shown in FIG. 3 is larger than the rotation speed of the roller 110 in the first rubbing shown in FIG. Also in this modification, the pretilt angle is reduced as in the above-described embodiment.

  Next, an experimental result in which the method for manufacturing the liquid crystal display device according to this embodiment is applied will be described.

  FIG. 4 is a diagram for explaining an experimental process to which a conventional rubbing method is applied. In this experiment, the first roller 1 and the second roller 2 are rotated in the same direction, and the substrate 3 (color filter substrate) on which the alignment film is applied in the same direction as the movement of the rubbing cloth 4 on the side facing the rubbing cloth 4. And the TFT substrate) were moved. The moving speed was 40 mm / s. It should be noted that the pressing amount representing the magnitude of the force with which the rubbing cloth 4 of the first roller 1 and the second roller 2 presses the substrate 3 was made different between the color filter substrate and the TFT substrate.

  FIG. 5 is a diagram for explaining an experimental process to which the present embodiment is applied. In this experiment, the 1st roller 1 and the 2nd roller 2 were rotated in the opposite direction, and the board | substrate 3 was moved so that the content demonstrated by the said embodiment may correspond. In addition, experiment of 3 patterns of specifications 1, 2, and 3 was performed by changing the amount of pushing. The other conditions are the same as in the experiment shown in FIG.

  The results of each experiment are as follows.

  In the column of “push amount” in the table, “CF” represents the push amount with respect to the alignment film formed on the color filter substrate, and “TFT” represents the push amount with respect to the alignment film formed on the TFT substrate. . Further, the numerical value of the pushing amount is described in the order of “the pushing amount of the first roller 1 / the pushing amount of the second roller 2”.

  As can be seen from the table, the pretilt angle that was 2.66 ° in the conventional method is 2.17 °, 2.16 °, and 2.35 ° in the specifications 1, 2, and 3, respectively, when this embodiment is applied. Thus, it was found that the pretilt angle is small in any specification.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the configuration described in the embodiment can be replaced with substantially the same configuration, a configuration that exhibits the same operational effects, or a configuration that can achieve the same purpose.

10 roller, 12 alignment film, 14 rubbing cloth, 16 substrate, 18 stage, 20 first roller, 22 second roller, 110 roller, 114 rubbing cloth, F ₁ pushing amount, F ₂ pushing amount.

Claims (7)

A rubbing step of rubbing the surface of the alignment film with a rubbing cloth wound around the roller while moving the alignment film relative to the rotating roller;
The rubbing step is performed so that the rubbing cloth rubs the alignment film in a direction opposite to the moving direction of the alignment film, and then the rubbing cloth rubs the alignment film in the moving direction of the alignment film. A method for manufacturing a liquid crystal display device, wherein In the manufacturing method of the liquid crystal display device described in Claim 1,
The roller includes a first roller, and a second roller positioned in front of the first roller in the direction of movement of the alignment film,
The rubbing cloth is wound around each of the first roller and the second roller,
On the side where the first roller and the second roller face the alignment film, the rotation direction of the first roller and the movement direction of the alignment film are opposite, and the rotation direction of the second roller and the alignment film The liquid crystal display device manufacturing method is characterized in that the moving direction of the liquid crystal display device is the same. In the manufacturing method of the liquid crystal display device described in Claim 2,
An amount of pressing of the rubbing cloth wound around the second roller into the alignment film is larger than an amount of pressing of the rubbing cloth wound around the first roller into the alignment film. Production method. In the manufacturing method of the liquid crystal display device described in Claim 2 or 3,
The method of manufacturing a liquid crystal display device, wherein the rotation speed of the second roller is larger than the rotation speed of the first roller. In the manufacturing method of the liquid crystal display device described in Claim 1,
After performing the first rubbing by the roller so that the rubbing cloth rubs the alignment film opposite to the moving direction of the alignment film,
A method of manufacturing a liquid crystal display device, characterized in that the rubbing is performed a second time by the roller so that the rubbing cloth rubs the alignment film in the same direction as the movement direction of the alignment film. In the manufacturing method of the liquid crystal display device described in Claim 5,
A manufacturing method of a liquid crystal display device, wherein a pressing amount of the rubbing cloth with respect to the alignment film in the second rubbing is larger than a pressing amount of the rubbing cloth with respect to the alignment film in the first rubbing. Method. In the manufacturing method of the liquid crystal display device according to claim 5 or 6,
The method of manufacturing a liquid crystal display device, wherein a rotation speed of the roller in the second rubbing is larger than a rotation speed of the roller in the first rubbing.

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