JPH1068952A - Production of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a liquid crystal display device capable of obtain the liquid crystal display device having a high contrast by dispersedly arranging spacers in non-pixel regions at the time of or after injection of a liquid crystal material. SOLUTION: Color filters 2 and light shielding layers 3 are formed on a counter substrate 1 and counter electrodes 5 are formed over the entire surface of this counter substrate 1. An oriented film 7 for orienting the liquid crystal material 6 is formed. Display electrodes 8 and signal lines 9 are formed on an active matrix substrate 4. The oriented film 7 is so formed as to cover these display electrodes 8 and signal lines 9. The counter substrate 1 and the active matrix substrate 4 are stuck to each other via the spacers 10a dispersedly arranged in the non-pixel regions, the spacers 10b dispersedly arranged in the pixel regions and sealants. The liquid crystal material 6 is injected between the counter substrate 1 and the active matrix substrate 4 stuck to each other. The spacers 10b dispersedly arranged in the pixel regions are moved by the flow of the liquid crystal material 6 in this injection and are stopped and fixed at the non-pixel regions. The spacers 10b dispersedly arranged in the pixel regions are all moved to the non-pixel regions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal display device used for a direct-view display device such as a transmission type or a reflection type, a projection type display device and various information processing devices. More specifically, the present invention relates to a method for manufacturing a liquid crystal display device in which spacers for controlling the distance between a pair of substrates with a liquid crystal material interposed therebetween are selectively dispersed between the pair of substrates.

[0002]

2. Description of the Related Art A liquid crystal display device has a structure in which a pair of substrates, at least one of which has a light-transmitting property, is arranged at a predetermined distance, and a liquid crystal material is injected between the pair of substrates.

In order to maintain the above-mentioned predetermined interval,
For example, after the spacers are dispersedly arranged on the surface of the substrate on the liquid crystal material side, the pair of substrates is bonded to each other, so that the distance between the pair of substrates is kept substantially equal to the size of the spacer. Generally, the spacers are distributed over substantially the entire surface of the substrate on the liquid crystal material side.

[0004] When dispersing spacers on a substrate, if the spacers are present in a region (pixel) actually involved in display, the spacers exhibit optical anisotropy different from that of a liquid crystal material. Light leakage occurs, which causes a problem of lowering contrast.

In order to solve such a problem, a method has been proposed in which spacers are dispersed only in non-pixel regions. As a method of dispersing spacers only in non-pixel regions, a method of dispersing spacers only in non-pixel regions using a thermoplastic resin, a method of dispersing spacers only in non-pixel regions using electric potential, A method of dispersing and disposing them in a black mask has already been proposed.

[0006]

A method of dispersing and disposing spacers only in non-pixel regions using a thermoplastic resin is as follows.
Before applying the alignment film, a thermoplastic resin film is formed on the substrate, and after patterning the thermoplastic resin film, the spacers are sprayed and heated, thereby bonding and fixing the spacers only to the non-pixel regions. Is the way.

Therefore, when the alignment film is applied by the offset printing method or the flexographic printing method, the spacer may be peeled off from the substrate when the relief is pressed onto the substrate. Will adhere to

Further, when the alignment film is applied on the next substrate, the spacer attached to the relief plate is transferred to the substrate. Since the transferred spacer is not fixed on the substrate, it is peeled off in the subsequent rubbing step, washing step, etc., particularly when the spacer is transferred on the pixel area, the area where the transferred spacer is peeled off is oriented. This results in a state where no film is formed.

In other words, when a pinhole is present on the alignment film and the liquid crystal display device is completed, it becomes impossible to align the liquid crystal at the pinhole portion on the alignment film, resulting in poor display and non-defective products. Has a problem such as a decrease in

In the rubbing step, the rubbing cloth comes into contact with the spacer fixed on the substrate.
The fluff of the rubbing cloth in contact with the spacer is disturbed. The alignment film rubbed at the portion where the nap of the rubbing cloth is disturbed has a variation in the tilt angle, so that when it is completed as a liquid crystal display device, display defects occur.

Further, the spacers adhered and fixed to the non-pixel regions may be peeled off during rubbing, and if rubbing is continued in that state, the alignment film will be damaged, resulting in a display failure and a decrease in non-defective products. It also has the problem of causing

The method of dispersing and disposing the spacer only in the non-pixel region using the electric potential is performed by charging the spacer and charging the non-pixel region to a polarity opposite to that of the spacer.
This is a method of attaching a spacer to a non-pixel region.

However, since the spacers scattered in the sealed device settle down and adhere to the substrate, if the potential difference between the spacers and the non-pixel regions is small, the spacers adhere to the pixel regions as well. When completed as a liquid crystal display device, there is a problem that light leaks from a spacer existing on the pixel region, leading to a reduction in contrast.

Conversely, when the potential difference between the spacer and the non-pixel region is large, when the liquid crystal display device is completed,
There is also a problem that a display defect occurs due to the charged spacers and non-pixel regions, which lowers the non-defective rate. Further, in an active matrix type liquid crystal display device, the active element may be broken.

In the method of disposing the spacers in the black mask, the rubbing is performed after the spacers are fixed to the black mask. The fur of the cloth is disturbed. The alignment film rubbed at the portion where the nap of the rubbing cloth is disturbed has a variation in the tilt angle, so that when it is completed as a liquid crystal display device, display defects occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. The present invention is directed to dispersing spacers in a non-pixel region at the time of injecting a liquid crystal material or after injecting a liquid crystal material to thereby improve contrast. It is an object of the present invention to provide a method for manufacturing a liquid crystal display device capable of obtaining a high liquid crystal display device.

[0017]

In order to achieve the above-mentioned object, a method of manufacturing a liquid crystal display device according to the first aspect of the present invention controls a distance between a pair of substrates disposed to face each other with a liquid crystal material interposed therebetween. In the method for manufacturing a liquid crystal display device, the spacers to be selectively dispersed and disposed between the pair of substrates are arranged such that the substrate interval in a non-pixel region is smaller than the substrate interval in a pixel region, and when the liquid crystal material is injected or After the injection of the liquid crystal material, the spacer is dispersedly arranged in the non-pixel region by moving the liquid crystal material.

According to a second aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device according to the first aspect.
A light-shielding layer formed to shield the non-pixel region from light may reduce the distance between the substrates in the non-pixel region to be smaller than the distance between the substrates in the pixel region.

According to the method of manufacturing a liquid crystal display device of the present invention, the distance between the substrates in the non-pixel region is made smaller than the distance between the substrates in the pixel region, and the liquid crystal material is moved at the time of injecting the liquid crystal material or after injecting the liquid crystal material. Accordingly, by dispersing the spacers in the non-pixel region, the spacers existing on the pixel region are eliminated, so that it is possible to prevent the scattering of light in the spacer and the decrease in contrast due to the light leakage from the spacer.

Further, since the spacers can be dispersedly arranged in the non-pixel region after the alignment film application step, the spacers do not peel off from the substrate, and the spacers do not peel off from the substrate. Pinholes and scratches on the alignment film are eliminated, and display defects caused by these are eliminated.

Further, since the spacers can be dispersedly arranged in the non-pixel region after the rubbing step, the rubbing cloth does not come into contact with the spacer fixed on the substrate. Hairs are not disturbed, and display defects caused by these are eliminated.

Further, since there is no need to charge the spacer, display defects and destruction of the active element due to this do not occur.

Further, by making the substrate interval of the non-pixel region smaller than the substrate interval of the pixel region by a light-shielding layer formed to shield the non-pixel region, a new thickness can be obtained by forming the light-shielding layer thicker. Since a step is not required, there is no increase in cost.

Further, the light shielding performance can be improved by increasing the thickness of the light shielding layer.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a liquid crystal display device according to the present invention, and FIG. 2 is a perspective view showing an example of a method of moving a spacer.

As shown in FIG. 1, a color filter 2 made of a pigment is formed on a counter substrate 1 made of glass, and a light-shielding layer 3 is formed in a non-pixel region using the same pigment.

By forming the color filter 2 and the light-shielding layer 3 with the same pigment, the formation of the color filter 2 and the formation of the light-shielding layer 3 can be performed in the same manner, so that the cost is not increased.

Further, by increasing the thickness of the light-shielding layer 3, the light-shielding performance of the light-shielding layer 3 can be improved, and the distance between the opposing substrate 1 and the active matrix substrate 4 in the non-pixel region can be reduced. The distance between the opposing substrate 1 and the active matrix substrate 4 can be made smaller,
The spacer can be fixed to the non-pixel region.

On the color filter 2 and the light shielding layer 3,
A counter electrode 5 for performing display is formed on the entire surface of the counter substrate 1, and an alignment film 7 for aligning the liquid crystal material 6 is formed on the counter electrode 5.

A display electrode 8 for performing display is formed on an active matrix substrate 4 made of glass, and a signal line 9 connected to the display electrode 8 via a TFT or the like is formed. The signal line 9 supplies a signal for supplying charges to the display electrode 8 or controlling the supply of charges. Then, an alignment film 7 is formed so as to cover the display charges 8 and the signal lines 9.

The opposing substrate 1 and the active matrix substrate 4 are arranged in a spacer 10 in a non-pixel region.
a, bonding is performed via a spacer 10b and a sealant dispersedly arranged in the pixel region.

Spacers 10 distributed in non-pixel areas
a controls the distance between the opposing substrate 1 and the active matrix substrate 4, while the spacers 10 b dispersed in the pixel region are used to control the distance between the opposing substrate 1 and the active matrix substrate 4.
Because it is not sandwiched between them, it is in a state where it can move freely.

A liquid crystal material 6 is injected between the bonded opposing substrate 1 and the active matrix substrate 4. Due to the flow of the liquid crystal material 6 in this injection, the spacers 10b dispersedly arranged in the pixel region move, stop and be fixed in the non-pixel region, and are dispersed in the pixel region.
0b all move to the non-pixel area. At this time, the spacers 10a dispersedly arranged in the non-pixel region are
And the active matrix substrate 4, it does not move.

Spacers 10b dispersed in the pixel area
When the movement of the liquid crystal material 6 is insufficient, it is possible to move the spacers 10b dispersedly arranged in the pixel region by various methods. As an example, as shown in FIG. , Roller 11 and liquid crystal display device 1
By rolling while applying pressure to 2, the liquid crystal material 6 can be moved, and the spacers 10b dispersed in the pixel region can be moved to the non-pixel region.

As described above, a liquid crystal display device with high contrast can be obtained without any spacer in the pixel region.

[0036]

As described above, according to the method of manufacturing a liquid crystal display device of the present invention, the distance between the substrates in the non-pixel region is made smaller than the distance between the substrates in the pixel region. After the injection of, the liquid crystal material is moved to disperse the spacers in the non-pixel region, so that there is no spacer present on the pixel region.
A liquid crystal display device with high contrast can be obtained.

Furthermore, since the spacers can be dispersedly arranged in the non-pixel region after the alignment film coating step, display defects caused by pinholes in the alignment film and scratches on the alignment film are eliminated.

Furthermore, since the spacers can be dispersedly arranged in the non-pixel regions after the rubbing step, display defects due to the disorder of the rubbing cloth in the portion in contact with the spacers are eliminated.

Further, display defects and destruction of the active element due to charging of the spacers do not occur.

Further, by making the substrate interval of the non-pixel region smaller than the substrate interval of the pixel region by a light-shielding layer formed for shielding the non-pixel region, a new thickness can be obtained by forming the light-shielding layer thicker. Since a step is not required, there is no increase in cost.

Further, by increasing the thickness of the light-shielding layer, the light-shielding performance can be improved, and the deterioration of the characteristics of the TFT or the like can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a perspective view illustrating an example of a method of moving a spacer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Counter substrate 2 Color filter 3 Shield layer 4 Active matrix substrate 5 Counter electrode 6 Liquid crystal material 7 Alignment film 8 Display electrode 9 Signal line 10a Spacer dispersed in non-pixel region 10b Spacer dispersed in pixel region 11 Roller 12 Liquid crystal display apparatus

Claims (2)

[Claims] 1. A method of manufacturing a liquid crystal display device, wherein spacers for controlling a distance between a pair of substrates disposed opposite to each other with a liquid crystal material interposed therebetween are selectively dispersed between the pair of substrates. The distance between the substrates is made smaller than the distance between the substrates in the pixel region, and the spacer is dispersedly arranged in the non-pixel region by moving the liquid crystal material during or after the injection of the liquid crystal material. A method for manufacturing a liquid crystal display device characterized by the above-mentioned. 2. A light-shielding layer formed to shield the non-pixel region from light, wherein the substrate interval in the non-pixel region is made smaller than the substrate interval in the pixel region. Of manufacturing a liquid crystal display device.