JP3087164B2 - Liquid crystal display 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 method for manufacturing a liquid crystal display panel.

[0002]

2. Description of the Related Art As a method for aligning liquid crystal molecules in a predetermined direction, a method of applying a photosensitive substance (alignment film) on a substrate surface and then performing an alignment treatment by irradiating ultraviolet rays is disclosed in Japanese Patent Laid-Open No. 4-75.
It is shown in Japanese Patent Publication No. 20 and the like. The outline of the conventional alignment treatment by light irradiation will be described below with reference to the drawings.
FIG. 5 is a perspective view showing the outline of this photo-alignment treatment. Ultraviolet rays from an ultraviolet light source 51 such as a high-pressure mercury lamp or a laser are collimated by a collimator 52 onto a substrate 56 having a surface coated with a photosensitive substance 55 for alignment. A method of aligning a photosensitive substance 55 by irradiating a light beam and irradiating linearly polarized light 54 with a polarizing device 53 comprising a linear polarizing plate or a Glan-Thompson type optical element is shown.

At this time, the orientation direction and pretilt angle of the liquid crystal molecules can be controlled by the direction of the polarization vector, the irradiation energy, the energy angle, and the like. OCB mode (optically compensated birefringence mode),
Liquid crystal display panels of a TN mode (twisted nematic), an STN mode (super twisted nematic) and the like have been manufactured. FIG. 6 shows an example of a liquid crystal display panel manufactured using two substrates which have been subjected to the alignment treatment by the light irradiation. FIG. 1 is a cross-sectional view showing a schematic configuration of a liquid crystal panel in which the two substrates are bonded together while maintaining a predetermined gap.
The polarizing plate 57 is attached to the outside of the two substrates 56 after the two substrates 56 having the photosensitive material 55 subjected to the alignment treatment are attached with a cell gap d therebetween. Incidentally, 58 is a seal resin, and 59 is a liquid crystal.

[0004]

However, the STN
Since a mode liquid crystal display panel, a TN mode liquid crystal display panel, or the like has an electro-optical display function, a linear polarizing plate is indispensable as an optical member itself. In the conventional method, as shown in FIG. In order to irradiate the photosensitive substance (alignment film) 55 with the linearly polarized light 54 of the ultraviolet wavelength to the photosensitive material 55, an apparatus having an optical system equipped with an optical element 53 for linearly polarizing the ultraviolet is used. There is a problem that the system becomes complicated, and when forming an orientation mode unique to the liquid crystal display panel, such as HM, TN, or ST, the operation must be performed before bonding the panels. However, this was a manufacturing constraint.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, simplifies the alignment processing step, and provides a liquid crystal display panel having an alignment mode such as HM, TN, or ST even after panel bonding. It is an object of the present invention to provide a method of manufacturing a liquid crystal display panel which can be manufactured in a variety of ways.

[0006]

According to a method of manufacturing a liquid crystal display panel of the present invention, a step of applying a photosensitive substance to one side of a substrate, and a step of applying a linearly polarized light to the other side of the substrate coated with the photosensitive substance. A step of attaching a plate and a step of irradiating ultraviolet rays through the linear polarizing plate to perform a photo-alignment treatment on the photosensitive substance.

According to the present invention, the linear polarization of the ultraviolet light source and the light irradiation required for the light alignment irradiation are performed by the linear polarizing plate of the component member of the liquid crystal display panel. Since an optical system for linear polarization can be omitted, and a predetermined alignment process can be performed by light irradiation even after the liquid crystal panels are bonded, the alignment modes such as TN, STN, and OCB are provided after the panels are bonded. A liquid crystal display panel can be configured.

[0008]

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

(Embodiment 1) FIG. 1 is a perspective view showing an outline of a photo-alignment process in Embodiment 1 of a method of manufacturing a liquid crystal display panel according to the present invention. In the figure, a photosensitive substance 15 serving as an alignment film is applied to one surface of a liquid crystal panel substrate 16 (first step), and a linear polarizing plate 13 is attached to the other surface.
(Second step) The photosensitive material 15 is irradiated with light 100 that has been linearly polarized through a linear polarizer 13 by converting ultraviolet light from an ultraviolet light source 11 such as a high-pressure or low-pressure mercury lamp into a parallel beam by a collimator 12 on a substrate 16 ( Third step). At this time, the wavelength of the ultraviolet light source 11 for irradiating light can be in a region around 254 nm, 300 nm, and 365 nm. As the photosensitive material 15, polyacrylate, polyvinyl, amide, imide can be used,
Further, a material such as a silane compound or a polysilane compound, or a mixed material of the above-mentioned material systems can be used.

FIG. 2 shows an example of a liquid crystal display panel manufactured using two substrates subjected to the photo-alignment treatment in the first to third steps. FIG. 2 is a cross-sectional view showing a schematic configuration of a liquid crystal panel in which the two substrates are bonded together while maintaining a predetermined gap, and as described above, the polarizing plate 13 is provided on one side and the polarizing plate 13 is provided on the other side. The two substrates 16 having the photosensitive material 15 subjected to the alignment treatment are bonded to each other with a cell gap d therebetween, and a liquid crystal 19 is inserted into the gap d. Reference numeral 18 denotes a sealing resin. Since the photosensitive substance 15 is thus subjected to the alignment treatment by light irradiation, the molecules of the inserted liquid crystal 19 are aligned in a predetermined direction.

As described above, according to the present embodiment, the optical alignment process is performed using the linear polarizing plate used as a component member of the liquid crystal display panel, and the polarizing plate used for the optical alignment process is used. It is also used for the construction of the display panel, and by bonding this to the substrate to complete the liquid crystal display panel, the optical system in optical alignment at the time of manufacturing is simplified, and various alignment modes of the liquid crystal display panel are easily performed. Can be realized.
For example, in the alignment mode used for the liquid crystal display panel, T
In the case of forming the N (twisted nematic) mode, the liquid crystal inserted in the gap d between the two substrates in the cross-sectional view of FIG.
It can be implemented by pasting so that 19 molecules are at an angle of about 90 ° to each other on the surface of the photosensitive material 15 on both sides,
In the case of configuring an STN (super twisted nematic) mode, it can be implemented by bonding such that an angle of approximately 180 ° to 270 ° is formed. In addition,
These bonding angles are not limited to the above-described TN mode and STN mode, and it is naturally possible to perform bonding at an arbitrary angle.

(Embodiment 2) FIG. 3 is a perspective view showing an outline of a photo-alignment process in Embodiment 2 of a method of manufacturing a liquid crystal display panel of the present invention. In the figure, a photosensitive material 35 serving as an alignment film is applied and formed on one side of both sides of two substrates 36 (first step), and a linear polarizing plate 33 is attached on the other side (second step). )) After that, bonding is performed while maintaining a constant gap d (third step). In this state, light irradiation is performed in the same manner as in the first embodiment.
By means of using two sets of collimators 32, the process is performed from both the front side and the back side of the two substrates 36 (fourth step).
Further, the same region as in the first embodiment can be used for the orientation angle and the wavelength of the ultraviolet light source 31 for irradiating the light on both sides.

Next, if a liquid crystal is inserted into the gap d of the liquid crystal display panel which has been subjected to the photo-alignment processing in the first to fourth steps, the photosensitive substance 35 has been subjected to the photo-alignment processing in advance. The liquid crystal inserted in d is oriented in a predetermined direction as in the first embodiment.

As described above, according to the present embodiment, at the same time as performing the optical alignment processing using the linear polarizing plate used as a constituent element of the liquid crystal display panel, the polarizing plate is configured as a liquid crystal display panel. It is also used naturally, and by bonding this to the substrate to complete the liquid crystal display panel, the optical system at the time of manufacturing is simplified, and even after the panel bonding, various alignment modes used for the liquid crystal display panel can be used. Can be easily realized.

(Embodiment 3) FIG. 4 is a perspective view showing an outline of a photo-alignment process in Embodiment 3 of a method of manufacturing a liquid crystal display panel of the present invention. In the figure, a photosensitive substance 45 serving as an alignment film is applied and formed on one side of both sides of two substrates 46 (first step), and a linear polarizing plate 43 is attached to the other side (second step). ) After that, bonding with a certain gap d
(Third step) Then, the liquid crystal 49 is inserted into the gap d.
(4th process). Reference numeral 48 denotes a sealing resin for the liquid crystal 49. In this state, as in the second embodiment, light is irradiated from both sides of the two substrates 46 by means such as using two sets of the ultraviolet light source 41 and the collimator 42 (fifth step). Use 365nm. This is 254nm, 300n
This is because when the light of m is irradiated, the molecules of the liquid crystal 49 already inserted are likely to be decomposed.

As described above, according to the present embodiment, the linear alignment plate used for the liquid crystal display panel is used to perform the optical alignment processing, and the polarizing plate used for the optical alignment processing is constituted by the structure of the display panel. By bonding this to the substrate to complete the liquid crystal display panel, the optical system at the time of manufacturing is simplified, and various alignment modes used for the liquid crystal display panel after panel bonding are easy. Can be realized.

(Embodiment 4) A method of manufacturing a liquid crystal display panel according to Embodiment 4 of the present invention is a modification of the light irradiation by the ultraviolet light source in Embodiments 2 and 3 described above. In each of the embodiments, the light is irradiated from both sides of the substrate, but the light is irradiated only from one side of one substrate.

When light is irradiated only from one side of one substrate as described above, the photosensitive substance applied to the one side substrate is oriented in a predetermined direction, and the liquid crystal molecules on the surface are also oriented in a predetermined direction. However, the photosensitive material applied to the other substrate can also be oriented by increasing the light irradiation intensity, and in this case, the orientation is performed in the same direction on the photosensitive material surfaces on both sides, so that the homogeneous mode is used. It is suitable for manufacturing a basic liquid crystal display panel.

[0019]

As described above, according to the present invention, the linear polarization of the ultraviolet light source and the light irradiation necessary for light alignment irradiation are performed by using the linear polarizing plate as a component member of the liquid crystal display panel.
The optical system in optical alignment can be simplified, and a predetermined alignment process can be performed by light irradiation after bonding the liquid crystal panels.
An advantageous effect that a liquid crystal display panel having an alignment mode such as N or OCB can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline of a photo-alignment process in Embodiment 1 of a method for manufacturing a liquid crystal display panel of the present invention.

FIG. 2 is a cross-sectional view of the liquid crystal display panel manufactured according to the first embodiment of the method for manufacturing a liquid crystal display panel of the present invention.

FIG. 3 is a diagram showing an outline of a photo-alignment treatment in a second embodiment of the method of manufacturing a liquid crystal display panel of the present invention.

FIG. 4 is a diagram showing an outline of a photo-alignment process in a third embodiment of the method for manufacturing a liquid crystal display panel of the present invention.

FIG. 5 is a perspective view illustrating an outline of a photo-alignment process in a conventional liquid crystal display panel manufacturing method.

FIG. 6 is a cross-sectional view of a liquid crystal display panel manufactured by a conventional liquid crystal display panel manufacturing method.

[Explanation of symbols]

11, 31, 41, 51 ... ultraviolet light source, 12, 32, 42, 52 ... collimator, 13, 33, 43 ... polarizing plate, 54, 100 ... linearly polarized light, 15, 35, 45, 55 ... photosensitive Substance, 16,36,
46, 56 ... substrate, 18, 38, 48, 58 ... seal resin, 29,
49, 59: liquid crystal, d: cell gap.

Claims (4)

(57) [Claims] 1. A method for manufacturing a liquid crystal display panel, comprising inserting a liquid crystal between a pair of substrates having a surface coated with a photosensitive material for orienting liquid crystal molecules in a predetermined direction, wherein the photosensitive material is provided on one side of the substrate. Applying a linearly polarizing plate to the other side surface of the substrate coated with the photosensitive substance, and irradiating ultraviolet rays through the linearly polarizing plate to perform a photo-alignment treatment on the photosensitive substance. A method for manufacturing a liquid crystal display panel, comprising: 2. A step of bonding a pair of substrates coated with a photosensitive substance for aligning liquid crystal molecules in a predetermined direction by irradiation of ultraviolet rays while maintaining a predetermined gap, and placing a linear polarizing plate outside the pair of substrates. Laminating, inserting a liquid crystal into a predetermined gap between the pair of substrates, and irradiating ultraviolet rays through the linear polarizing plate to perform a photo-alignment process on the photosensitive material and the liquid crystal. Liquid crystal display panel manufacturing method. 3. A step of bonding a pair of substrates coated with a photosensitive substance for aligning liquid crystal molecules in a predetermined direction by irradiation of ultraviolet rays while maintaining a predetermined gap, and placing a linear polarizing plate on the outside of the pair of substrates. A step of bonding and having a step of irradiating ultraviolet rays through the linear polarizing plate to perform a photo-alignment treatment on the photosensitive substance, and after the step of performing a photo-alignment treatment on the photosensitive substance, A method for manufacturing a liquid crystal display panel, comprising a step of inserting a liquid crystal into a gap. 4. The liquid crystal display according to claim 1, wherein the ultraviolet irradiation in the step of performing the photo-alignment treatment is performed only from one of the pair of substrates. Panel manufacturing method.