JP3112739B2 - Liquid crystal panel manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel and, more particularly, to a method for manufacturing a liquid crystal panel in which alignment division is performed to improve the viewing angle characteristics of the liquid crystal panel.

[0002]

2. Description of the Related Art Liquid crystal display devices have attracted attention as a substitute for CRTs because of their thinness, lightness, and high display quality. A liquid crystal display device includes a liquid crystal panel in which liquid crystal is sealed between a pair of transparent substrates. A transparent electrode and an alignment film are provided on the inner surface of the substrate of the liquid crystal panel, respectively, and a voltage is applied between these transparent electrodes to drive the liquid crystal to form an image. For example, when no voltage is applied, the liquid crystal molecules are oriented almost parallel to the substrate surface,
When a voltage is applied, the liquid crystal molecules rise in a predetermined direction with respect to the substrate surface in accordance with the rubbing direction, so that an image is formed by changing the light transmittance between the two states.

It is known that a liquid crystal display has a viewing angle characteristic according to a rubbing direction. That is, the display characteristics change depending on the direction in which the viewer views the screen from above, below, left, and right.
For example, when the screen is viewed from above, the display tends to be relatively dark, and when viewed from below, the screen tends to be too bright. Such a viewing angle characteristic occurs depending on from which direction the viewer views the screen with respect to the rising direction of the liquid crystal molecules.

In order to improve the viewing angle characteristics of such a liquid crystal display device, it has been proposed to perform alignment division. As described above, the alignment division rubs the alignment film of the substrate in a different direction for each minute region so as to correspond to the pixel area, so that the liquid crystal molecules alternately rise in the opposite direction for each minute region. For example, a dark characteristic when the screen is viewed from above and a characteristic that is too bright when viewed from below are averaged so that a good display can be obtained from any direction.

In order to perform the orientation division, it is necessary to rub the orientation film of the substrate in a different direction for each minute region so as to correspond to the pixel area. Conventionally, in order to perform such rubbing, first a first opening having a minute opening is provided.
The first rubbing is performed by covering the alignment film with the first mask, and then rubbing in a different direction from the first using a second mask having an opening complementary to the first mask. Was. Rubbing is performed by rubbing the alignment film using a rubbing roller wound with a fibrous rubbing material. In order to perform orientation division so as to have a pitch of several tens of μm, for example, it has been proposed to use a photolithography technique in which a resist is applied to an orientation film and this is etched to use the mask as a mask.

[0006]

However, in the orientation division using the photolithography technique, it is necessary to repeat the application, etching, and removal of the resist twice on the orientation film. There was a problem that it increased. Further, although it is effective to form the alignment film with a polyimide resin, if the developing and stripping solution is alkaline, the polyimide resin is dissolved. For this reason, if development and peeling are performed with an organic solvent such as acetone, it is necessary to provide the equipment with an explosion-proof structure due to the danger of explosion, and the equipment investment becomes large. An object of the present invention is to provide a method for manufacturing a liquid crystal panel in which alignment division can be performed relatively easily.

[0007]

According to the method of manufacturing a liquid crystal panel according to the present invention, when rubbing the liquid crystal panel substrates 10 and 12 provided with the alignment films 18 and 22 on the surface, the surface is formed at a constant fine pitch. The rubbing member 30 in which the projections and depressions 32 are located in one plane, rubs a part of the region of the alignment film in a certain direction (X), and then removes at least a part of the remaining region. Rubbing is performed in different directions (Y), and a plurality of micro regions having different alignment directions are formed in the alignment film.

[0008]

According to the above-described manufacturing method, a plurality of minute regions having different orientations can be aligned without using a mask as in the conventional method by using a rubbing member having a surface with irregularities formed at a fixed minute pitch. It can be formed into a film.

[0009]

FIG. 4 is a diagram showing an example of a liquid crystal panel with divided orientation. The liquid crystal panel has liquid crystal 14 sealed between a pair of transparent substrates 10 and 12. Lower substrate 1
The pixel electrode 16 and the alignment film 18 are provided on the inner surface of the zero.
A transparent common electrode 20 and an alignment film 22 are provided on the inner surface of the upper substrate 12. FIG. 3 is a diagram showing the pixel electrodes 16 of the lower substrate 10 and the associated active matrix driving means. The active matrix driving means includes a data bus line 24, a gate bus line 26, and a transistor (TFT) 28 disposed at the intersection thereof. A transistor (TFT) 28 is connected to the pixel electrode 16.

The liquid crystal panels shown in FIGS. 3 and 4 are divided in orientation. That is, as shown in FIG. 3, the area corresponding to one pixel includes the area A and the area B, and the area A and the area B
And the rubbing direction is changed. That is, the rubbing direction of the alignment film 18 on the lower substrate 10 is indicated by a dashed arrow, and the alignment direction of the alignment film 22 on the upper substrate 12 is indicated by a solid arrow. In the area A, the lower rubbing direction is lower left and the upper rubbing direction is upper left.
In the area B, the lower rubbing direction is upwardly sloping, and the upper rubbing direction is downwardly sloping. as a result,
The rising direction of the liquid crystal molecules is reversed as shown by the region A and the region B in FIG. Therefore, by making the liquid crystal molecules rise alternately in the opposite direction for each minute area,
The display performance is averaged so that good display can be obtained from any direction. Line YY is a common direction in FIGS. 3 and 4.

In order to perform the orientation division, it is necessary to change the rubbing direction for each minute area. In the present invention, rubbing is performed using the rubbing member 30 shown in FIG. The rubbing member 30 has a substantially flat lower part, and the lower part thereof is formed with irregularities on the surface at a constant fine pitch. In FIG. 1, the convex portion is indicated by 32. The protrusions 32 extend long at a constant fine pitch in one plane. The pitch between adjacent convex portions 32 is
When the orientation division divides one pixel into two, it corresponds to the length of one pixel. FIG. 1 shows the pixel electrode 16 so that the relationship can be understood. In the example, when the length of the pixel electrode 16 was 300 μm, the pitch between the projections 32 was 300 μm, and the width of the projections 32 was 50 μm.

At the time of rubbing, the rubbing member 30 is arranged so that each projection 32 is substantially at the center of the pixel electrode 16, and the rubbing member 30 is lightly pressed against the alignment film 16. Then, the rubbing member 30 is moved by a half pixel in the direction indicated by the arrow X in FIG. That is, a part of the region of the alignment film 16 is rubbed in a certain direction. In the case of the above dimensional relationship, it is possible to move by 100 μm and repeat this operation.

Next, the rubbing member 30 is lifted and returned to the initial position, or moved by a half pitch from the rubbing end position of the first rubbing (in the case of the above-described dimensional relationship, 150 mm).
μm) and lightly pressed against the alignment film 16. Then, the rubbing member 30 is moved by half a pixel in the direction indicated by the arrow Y in FIG. 1 (moved by 100 μm in the case of the above dimensions). That is, at least a part of the remaining region is rubbed in a different direction. This operation can be repeated. If the orientation division is two, the rubbing is completed. If the orientation division is two or more, rubbing of the remaining region is further performed. In this manner, rubbing as shown in FIG. 3 can be performed, and liquid crystal molecules can be aligned as shown in FIG. In addition,
FIG. 4 mainly shows the orientation of the liquid crystal molecules of the intermediate layer in the liquid crystal 14 between the lower substrate 10 and the upper substrate 12.

FIG. 2 is a view showing a method of manufacturing the rubbing member 30 of FIG. First, the photocurable resin layer 3 is formed on the supporting plate 34.
6 is transmitted. Next, a mask 38 having a chromium pattern is prepared on a glass substrate. The mask 38 has an opening 40 corresponding to the projection 32 of the rubbing member 30.
Then, the photo-curable resin layer 36 is covered with the mask 38 and irradiated with ultraviolet rays as shown by arrows. As a result, the photocurable resin layer 3 exposed from the opening 40 of the mask 38
The portion 6 is cured to form the convex portion 32 of the rubbing member 30. The rubbing member 30 is obtained by removing the remaining portion of the photocurable resin layer 36. When selecting the photo-curable resin layer 36, it is necessary to select a photo-curable resin layer 36 that is softer than the alignment films 16 and 22. The rubbing member 30 is provided with an alignment mark for rubbing.

FIGS. 5 and 6 show a second embodiment of the present invention. FIG. 5 shows a rubbing device, in which a liquid crystal panel support 50 and a rubbing material support 5 which are arranged vertically facing each other.
Including 1. The liquid crystal panel substrate support base 50 includes a lifting mechanism 52.
Is mounted on the transfer device 54 supported by the
2 allows the transfer device 54 to move in the horizontal direction while being movable up and down. On the other hand, the rubbing material 30 is supported at a fixed position. The liquid crystal panel substrate support base 50 is provided with a vacuum chuck groove 56 to hold the liquid crystal panel substrate by vacuum.

The rubbing material support 51 supports the rubbing material 30. The rubbing material 30 is formed in a container shape, and at least a lower part thereof is substantially flat and elastic. As in FIG. 1, irregularities are formed on the surface of the flat lower portion at a constant fine pitch. The protrusion is indicated by 32. A pressure chamber 58 is formed inside the rubbing material 30, and the tube 6
Zero is intended to supply the fluid pressure of a gas or liquid, preferably an inert gas.

At the time of rubbing, as in the case of FIG. 1, the rubbing member 30 is gently pressed toward the alignment film 16, and the rubbing member 30 rubs a partial area of the alignment film 16 in a certain direction. Rubbing at least a part of the remaining area in a different direction. In this example,
Fluid pressure is supplied to the pressure chamber 58 of the rubbing member 30, and the rubbing member 30 is pressed toward the alignment film 16 by pressure from the back surface. For this reason, the convex portion 32 of the rubbing member 30 is pressed against the alignment film 16 with a constant pressure, and uniform rubbing can be performed.

[0018]

As described above, according to the present invention,
A plurality of minute regions having different alignment directions can be formed in the alignment film without using a mask as in the related art, thus enabling a significant simplification of the rubbing process.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a view showing a production example of the rubbing material of FIG. 1;

FIG. 3 is a diagram showing one substrate surface of a liquid crystal panel and a rubbing direction.

FIG. 4 is a sectional view of a liquid crystal panel.

FIG. 5 is a diagram showing a second embodiment of the present invention.

FIG. 6 is a detailed view of the rubbing member of FIG. 5;

[Explanation of symbols]

 10, 12: substrate 16: pixel electrode 18: alignment film 20: common electrode 22: alignment film 30: rubbing member 32: convex portion

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-106624 (JP, A) JP-A-5-281545 (JP, A) JP-A-5-224209 (JP, A) JP-A-5-224209 257145 (JP, A) JP-A-4-372931 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/1337 505

Claims (3)

(57) [Claims] When rubbing a liquid crystal panel substrate (10, 12) provided with an alignment film (18, 22) on its surface, irregularities are formed on the surface at a fixed minute pitch and the projections (32) are formed. Is rubbed in a certain direction (X) by a rubbing member (30) located in one plane, and at least a part of the remaining region is rubbed in a different direction (Y). A method for manufacturing a liquid crystal panel, comprising: rubbing to form a plurality of micro regions having different alignment directions in the alignment film. 2. The method according to claim 1, wherein the rubbing member is made of a photocurable resin. 3. The method according to claim 1, wherein when the rubbing member is pressed against the liquid crystal panel substrate, a fluid pressure is applied from the back side of the rubbing member.