JP2002350874A - Liquid crystal display device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Conventionally, when a liquid crystal panel is manufactured by a vacuum injection method, even though the seal is already completely cured in an empty cell state in which the liquid crystal is not yet filled, the liquid crystal panel is manufactured. In some cases, the seal and the liquid crystal material show compatibility, and the alignment around the seal may be abnormal. SOLUTION: By providing a seal barrier 10 which forms a pattern parallel to the seal 6 inside the seal 6, it is possible to prevent the seal material from being eluted into the liquid crystal 3 and to prevent the occurrence of an abnormal alignment state around the seal 6. To prevent.

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 device used for OA equipment such as a personal computer, a word processor, a monitor display and a portable information communication equipment.

[0002]

2. Description of the Related Art Originally, an injection method and a dropping method are considered as a method of filling a liquid crystal in a liquid crystal cell in a method of manufacturing a liquid crystal display element. The former injection method is generally used in mass production. The liquid crystal is filled from the inlet of an empty cell by utilizing the capillary phenomenon and the pressure difference in a vacuum.

FIG. 7 shows a process chart for manufacturing a liquid crystal display element by an injection method. FIG. 8 shows a cross-sectional configuration diagram of the liquid crystal display element completed in this step. Reference numerals 2a and 2b denote substrates provided with a color filter, a black matrix or an active element. Reference numeral 3 denotes a liquid crystal sandwiched between the substrates 2a and 2b and sealed by a seal 6. Reference numeral 4 denotes a spacer for holding a gap between the substrates 2a and 2b. , 5b are deflection plates, and 7 is an alignment film for aligning liquid crystal molecules.

In this liquid crystal display device, a liquid crystal 3 is interposed between two substrates 2a and 2b having display electrodes and the like, spacers 4 are dispersed so as to form a predetermined gap, and ends of the substrates 2a and 2b are formed. The liquid crystal 3 is sealed by providing a seal 6 in the portion, and polarizing plates 5a, 5b are provided on each of the two substrates 2a, 2b.
And other optical films are installed in the most suitable locations.
The polarizing plates 5a and 5b may be one, two, or not used depending on the principle mode.

[0005] The liquid crystal display device thus formed is
In the case of the transmissive type, a display is illuminated from the opposite side of the display surface with a three-wavelength cold-cathode tube, etc., and in the case of the reflective type, a reflector is installed on the opposite side of the display surface to make it look brighter using external light be able to. In such a form, the liquid crystal display element can be driven as a display by voltage driving.

Hereinafter, a method of manufacturing a liquid crystal display element by a conventional injection method will be described with reference to FIG. In FIG. 7, first, the substrates 2a and 2b are cleaned (S1a, S1
b) After applying the liquid alignment film 7 to the substrates 2a and 2b by offset printing or the like, the alignment film 7 is formed through preliminary firing and main firing (S2a, S2b), and an alignment process such as rubbing is performed (S3a). , S3b). Generally, after rubbing, water washing is performed to remove foreign substances and dirt on the surface. Next, a seal material is applied to the substrate 2a by a drawing device or screen printing to form a seal 6 (S4a). FIG. 9 shows the seal pattern. Then, a spacer 4 having a predetermined size is sprayed to form a gap in the substrate 2b (S4b), and both substrates 2a and 2b are bonded together in the air (S5). Now, in order to control the gap of the liquid crystal display element, the entire two substrates 2a and 2b are pressurized by an air press or the like (S6), and the seal 6 is hardened when an optimum gap comes out (S7). Thereafter, the portion outside the substrate display area is cut (S8). In the injection method, the empty cell thus formed and the pool of the liquid crystal 3 are put in a vacuum chamber, and 0.2 × 1.3332 × 10 ² 〜
0.7 × 1.33322 × 10 ² [Pa] (0.2 to
The injection port of the empty cell is brought into contact with the liquid crystal 3 at about 0.7 [Torr], and the entire inside of the tank is opened to the atmosphere to fill the empty cell with the liquid crystal 3 (S9). Then, the injection port is sealed with a resin or the like (S10), and the liquid crystal 3 adhering to the liquid crystal display element is
Is cleaned and the entire liquid crystal display element is annealed to perform a realignment treatment of the liquid crystal 3 (S11).

As described above, the liquid crystal display device manufactured by the conventional manufacturing method includes TN mode, STN mode, ferroelectric liquid crystal,
It can correspond to any liquid crystal mode such as VA mode and IPS mode. At this time, the liquid crystal material and the alignment state are different for each purpose, and the relationship between the seal and the liquid crystal material is important.

[0008]

However, in a liquid crystal panel manufactured by a vacuum injection method, the seal has already been completely cured in an empty cell state in which the liquid crystal has not yet been filled. However, abnormalities in the orientation around the seal sometimes occurred during mass production. This is due to the difference in liquid crystal material composition, the alignment state and the driving method due to the difference in the mode of the liquid crystal panel, and in connection with the difference, slight elution component from the sealing material causes the boundary between the liquid crystal material and the alignment film. It is considered that some abnormality has occurred.

Various methods have been considered to solve the above-mentioned problems. However, at present, cost reduction of liquid crystal panels is most strongly required, and the number of steps is reduced as much as possible.
In addition, there is a strong demand for making panels with good performance.

In order to solve the above-mentioned problems, the present invention stabilizes the alignment state of any liquid crystal material in a compatible relationship with a seal, reduces the number of steps, and reduces the cost. It is an object of the present invention to provide a liquid crystal display device capable of realizing a manufacturing method.

[0011]

According to a first aspect of the present invention, there is provided a liquid crystal display element provided between a pair of opposed substrates and having a liquid crystal sealing seal having an injection port.
The spacer includes a spacer that keeps a space between the pair of substrates and a seal barrier that is provided inside a position where the seal is provided and prevents elution of the sealant.

According to the first aspect of the present invention, since the seal barrier is provided inside the seal to prevent elution of the seal material, the seal material can be prevented from being dissolved in the liquid crystal. Therefore, the alignment state around the seal is also stabilized, and display defects of the liquid crystal display element can be prevented. Providing the seal barrier also contributes to making the gap uniform in the plane.

The liquid crystal display device according to the second aspect is the first aspect.
In the described invention, the spacer is a columnar projection.

According to the second aspect of the invention, the same effects as those of the first aspect of the invention are exhibited.

According to a third aspect of the present invention, there is provided a liquid crystal display device.
In the described invention, the seal barrier and the spacer are made of a photosensitive material.

According to the third aspect of the present invention, in the second aspect of the present invention, since the seal barrier and the spacer of the columnar projection are made of the same photosensitive material, it is possible to manufacture them simultaneously. Therefore, an inexpensive manufacturing method that does not increase the number of steps can be realized.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid crystal display device and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1 is a cross-sectional configuration diagram of a liquid crystal display element according to an embodiment.
In FIG. 1, 1 to 7 are the same as those shown in FIG. The substrates 2a and 2b are made of a color filter substrate, an array substrate on which active elements are arranged, a substrate on which transparent electrodes are formed, and the spacer 4 is made of a resin-based material such as benzoquanamine or a spherical material made of SiO _2. In some cases, a rod-shaped member is used, and the spacer 4 is fixed to the substrates 2a and 2b in order to improve gap uniformity. In addition, the seal 6 formed around the liquid crystal display element is of a thermosetting type made of an epoxy resin, and an ultraviolet curing type such as a radical type or a cationic type.

The difference from the conventional liquid crystal display device is that the seal 6
The point is that the barrier 10 is formed inside. The height of the seal barrier 10 is desirably equal to or less than the height of the spacer 4, and should be equal to or less than the cell gap when the cell is completed. Also, seal barrier 1
It is suitable to form a pattern by a photolithography method or a printing method as a method of forming 0, and the material of the seal barrier 10 is also determined by a forming method such as photosensitivity and thermosetting.
Specifically, in the case of forming by a photolithography method, an ultraviolet curable composition based on an acrylic polymer which is a main component of a color filter, and in the case of forming by a printing method, a main component of a color filter. A composition based on a certain acrylic polymer and including a thermosetting agent is employed as the material of the seal barrier 10. Note that even when a composition including a thermosetting agent based on an acrylic polymer which is a main component of a color filter is employed, it can be formed by a photolithography method by mixing an ultraviolet curing agent. FIG. 2 shows the barrier pattern.

Next, FIG. 3 is a process diagram showing a process for manufacturing a liquid crystal display element. In FIG. 3, first, a substrate in which the seal barrier 10 is formed on one of the substrates 2a (2b) is prepared. Then, the substrates 2a and 2b are cleaned (S1
a, S1b), after applying the liquid alignment film 7 to the substrates 2a, 2b by offset printing or the like, forming the alignment film 7 through preliminary firing and main firing (S2a, S2b), and performing an alignment process by rubbing or the like. (S3a, S3b). Generally, after rubbing, water washing is performed to remove foreign substances and dirt on the surface. Next, a seal material is applied to the substrate 2a by a drawing device or screen printing to form a seal 6 (S4).
a), the seal 6 is a seal barrier 1 as shown in FIG.
It is formed so as to be outside 0. Then, spacers 4 of a predetermined size are scattered to form a gap in the substrate 2b (S4b), and both substrates 2a and 2b are bonded together in the air (S5). Now, in order to control the gap of the liquid crystal display element, the whole of the two substrates 2a and 2b is pressurized by an air press or the like (S6), and the seal 6 is hardened when an optimum gap comes out (S7). Thereafter, the portion outside the substrate display area is cut (S8). In the injection method, the empty cell thus formed and the pool of the liquid crystal 3 are put in a vacuum chamber, and 0.2 * 1.3332 * 10 < ² >
0.7 × 1.33322 × 10 ² [Pa] (0.2 to
The liquid crystal 3 is brought into contact with the injection port of the empty cell at about 0.7 [Torr], and the entire interior of the tank is opened to the atmosphere to fill the empty cell with the liquid crystal 3 (S9). Then, the injection port is sealed with a resin or the like (S10), the liquid crystal 3 attached to the liquid crystal display element is washed, the entire liquid crystal display element 1 is annealed, and the liquid crystal 3 is realigned (S11).

As described above, in the present invention, since the seal barrier 10 for preventing the elution of the seal material is provided inside the seal 6, a display defect phenomenon caused by impurities dissolved from the seal can be suppressed beforehand. Further, an inexpensive manufacturing process can be realized, and in addition, performance such as gap uniformity can be overcome because the seal barrier 10 is newly formed. Therefore, it is possible to provide a beautiful liquid crystal display device by improving the narrow gap accuracy and gap in-plane uniformity required in a new mode in the future, and realize a bright liquid crystal display device with improved alignment accuracy.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
1 is a cross-sectional configuration diagram of a liquid crystal display element according to an embodiment.
In FIG. 5, 1 to 7 are the same as those shown in FIG. The difference from the liquid crystal display device of the first embodiment is that a plurality of columnar projections 12 are formed at regular positions so as to form a predetermined gap. In the present embodiment, the projections 12 are formed on the substrate 2a, but there is no problem if they are formed on the substrate 2b. Generally, the projections 12 are formed by a photolithography method, and in the present embodiment, the seal barrier 10 is formed at the same time as the projections 12 are formed. The height of the seal barrier 10 may be the same as the height of the projection 12 forming the gap. However, the height of the seal barrier 10 is desirably equal to or less than the height of the protrusion 12, and the height of the seal barrier 10 must be equal to or less than the cell gap when the cell is completed. In addition, it is suitable to form a pattern by a photolithography method as a method of forming the seal barrier 10 and the protrusions 12, and the material of the seal barrier 10 has the same photosensitivity as the protrusions 12. Specifically, as described in the first embodiment, an ultraviolet curable composition based on an acrylic polymer as a main component of a color filter, or an acrylic polymer as a main component of a color filter is used as a base. A material obtained by adding an ultraviolet curing agent to a composition containing a heat curing agent is used as the material of the seal barrier 10. The barrier pattern is the same as that shown in FIG.

Next, FIG. 6 shows a process chart of a method of manufacturing a liquid crystal display element by the injection method using the above substrate. First, a substrate in which the protrusion 12 and the seal barrier 10 are formed on one substrate 2a (2b) by the method described above is prepared. The substrates 2a and 2b are cleaned (S1a and S1b), and the liquid alignment film 7 is coated with the substrates 2a and 2b by offset printing or the like.
After the application, the alignment film 7 is formed through preliminary firing and main firing (S2a, S2b), and an alignment process such as rubbing is performed (S3a, S3b). Generally, after rubbing, water washing is performed to remove foreign substances and dirt on the surface. Next, a seal material is applied to the substrate 2a by a drawing device or screen printing to form a seal 6 (S4a), and the seal 6 is formed outside the seal barrier 10 as shown in FIG. Then, both substrates 2a and 2b are bonded in the air (S5). Now, in order to control the gap of the liquid crystal display element, the whole of the two substrates 2a and 2b is pressurized by an air press or the like (S6), and the seal 6 is cured when an optimum gap comes out (S7). Thereafter, the portion outside the substrate display area is cut (S8). In the injection method, the empty cell thus formed and the pool of the liquid crystal 3 are put in a vacuum chamber, and 0.2 * 1.3332 * 10 < ² >
0.7 × 1.33322 × 10 ² [Pa] (0.2 to
The liquid crystal 3 is brought into contact with the injection port of the empty cell at about 0.7 [Torr], and the entire interior of the tank is opened to the atmosphere to fill the empty cell with the liquid crystal 3 (S9). Then, the injection port is sealed with a resin or the like (S10), the liquid crystal 3 attached to the liquid crystal display element is washed, the entire liquid crystal display element 1 is annealed, and the liquid crystal 3 is realigned (S11).

As described above, in the present invention, since the seal barrier 10 for preventing the elution of the sealing material is provided inside the seal 6, a display defect phenomenon caused by impurities dissolved from the seal can be suppressed beforehand. In addition, since the projection 12 and the seal barrier 10 are formed at the same time, the number of manufacturing steps of the liquid crystal display element is not increased, and in addition, since the seal barrier 10 is newly formed, performance such as gap uniformity can be overcome. Therefore, it is possible to provide a beautiful liquid crystal display device by improving the narrow gap accuracy and gap in-plane uniformity required in a new mode in the future, and realize a bright liquid crystal display device with improved alignment accuracy.

[0025]

According to the first aspect of the present invention, since the seal barrier is provided inside the seal to prevent elution of the seal material, it is possible to prevent the seal material from being dissolved in the liquid crystal. it can. Therefore, the alignment state around the seal is also stabilized, and display defects of the liquid crystal display element can be prevented. Providing the seal barrier also contributes to making the gap uniform in the plane.

According to the second aspect of the invention, the same effect as that of the first aspect of the invention is exhibited.

According to the third aspect of the present invention, in the second aspect of the present invention, since the seal barrier and the spacer of the columnar projection are made of the same photosensitive material, it is possible to manufacture them simultaneously. Therefore, an inexpensive manufacturing method that does not increase the number of steps can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal display element according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a barrier pattern according to the embodiment of the present invention.

FIG. 3 is a manufacturing process diagram of the liquid crystal display element according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram showing a seal pattern according to the embodiment of the present invention.

FIG. 5 is a sectional view of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 6 is a manufacturing process diagram of a liquid crystal display element according to a second embodiment of the present invention.

FIG. 7 is a manufacturing process diagram of a conventional liquid crystal display element.

FIG. 8 is a cross-sectional view of a conventional liquid crystal display device.

FIG. 9 is a schematic diagram showing a seal pattern of a conventional liquid crystal display element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 Substrate 2a, 2b Substrate 3 Liquid crystal 4 Spacer 5a, 5b Deflector 6 Seal material 7 Alignment film 10 Seal barrier 12 Projection

Claims (3)

[Claims] A liquid crystal sealing seal provided between a pair of opposed substrates and having an inlet; a spacer for maintaining a distance between the pair of substrates; and a spacer inside a position where the seal is provided. A liquid crystal display device comprising: a seal barrier provided to prevent elution of a seal material. 2. The liquid crystal display device according to claim 1, wherein the spacer is a columnar projection. 3. The liquid crystal display device according to claim 2, wherein the seal barrier and the spacer are made of a photosensitive material.