JPH1124084A - Liquid crystal display device and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: Provided is a liquid crystal display device in which light leakage from a spacer portion is prevented, and a method for manufacturing the same. A spacer is scattered on a first substrate having pixel electrodes corresponding to respective color filters of red (R), green (G) and blue (B), and a second substrate is formed thereon. What is claimed is: 1. A liquid crystal display device comprising: a liquid crystal display device in which liquid crystals are injected to a gap between the liquid crystal display devices, wherein the spacer is a colored spacer having a black color development color with respect to a color of a color filter corresponding to a pixel electrode on which the spacer is dispersed. Display device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Liquid crystal display devices are widely used in personal computers, portable electronic devices and the like. As shown in FIG. 2, the liquid crystal display device generally has a liquid crystal 7 sandwiched between two substrates 1 on which a color filter 4, a transparent electrode 3, an alignment film 9 and the like are formed. Here, the spacer 8 regulates the interval between the two substrates 1 and maintains an appropriate thickness of the liquid crystal layer.

In a conventional method of manufacturing a liquid crystal display device, spacers are randomly and uniformly dispersed on a substrate having pixel electrodes formed by forming transparent electrodes in a predetermined pattern, as shown in FIG. The spacers are arranged on the pixel electrodes, that is, also on the display portion of the liquid crystal display device.
The spacer is generally formed of a synthetic resin, glass, or the like. When the spacer is disposed on the pixel electrode, light leakage occurs in the spacer portion due to the depolarizing effect. Also, light leakage occurs due to disorder of the orientation of the liquid crystal on the spacer surface,
Contrast and color tone decrease, and display quality deteriorates.

In order to solve the above-mentioned problem, Japanese Patent Application Laid-Open No. 4-198919 discloses a color filter for blue (B) by arranging spacers by screen printing using a mask having openings. A liquid crystal display device in which spacers are arranged only on portions, that is, only on pixel electrodes constituting blue pixels, is disclosed. In this device, the spacer is disposed only in the blue pixel portion having the lowest visibility among the red, green and blue pixels, so that light leakage in the spacer portion is made inconspicuous.

However, in such a technique, light leakage is less noticeable in terms of luminosity than when a spacer is disposed in a green pixel portion or the like, but blue light leakage still remains from a spacer disposed in a blue pixel portion. Will occur. Also, in the manufacturing process, the mask comes into contact with the alignment film, which causes abnormal alignment of the liquid crystal, lowers the display quality, and also requires time for alignment and the like.
There were problems such as a decrease in productivity.

[0006]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a liquid crystal display device in which light leakage from a spacer portion is prevented and a method for manufacturing the same.

[0007]

According to the present invention, a spacer is scattered on a first substrate having pixel electrodes corresponding to red (R), green (G) and blue (B) color filters. A liquid crystal display device in which a second substrate is disposed facing the second substrate and liquid crystal is injected into a gap between the second substrate and the spacer. Is a liquid crystal display device which is a colored spacer having the following. Hereinafter, the present invention will be described in detail.

In the liquid crystal display device of the present invention, spacers are scattered on a first substrate having pixel electrodes corresponding to red (R), green (G) and blue (B) color filters, respectively. A second substrate is disposed on the upper side, and liquid crystal is injected into the gap. In this specification,
“Pixel electrode” is an electrode formed on the substrate in the same pattern as each of the red (R), green (G), and blue (B) color filters among the transparent electrodes constituting the liquid crystal display device. Means

A spacer made of a synthetic resin, glass, or the like,
When disposed on the pixel electrode, that is, in the color filter portion, the spacer portion causes light leakage due to the depolarizing effect.
Therefore, in the liquid crystal display device of the present invention, a colored spacer having a black color development color for a color filter corresponding to the pixel electrode on which the spacer is dispersed is used as the spacer. By using such a colored spacer, light leakage from the spacer portion can be prevented.

[0010] The above-mentioned black color development color for the color filter means a color which absorbs light of the color of the color filter when the liquid crystal display device is driven, and as a result, the spacer itself is observed to be substantially black. Say. Such a color is not particularly limited as long as it can absorb light of the color of the color filter. For example, the above-mentioned colored spacer is disposed on a pixel electrode corresponding to a red (R) color filter. In the case of being arranged on the pixel electrode corresponding to the color filter of cyan and green (G), the case of being arranged on the pixel electrode corresponding to the color filter of magenta and blue (B) Yellow color and the like.

In general, the colors of the red (R), green (G) and blue (B) color filters are shown in a chromaticity diagram (CIE diagram) in FIG. In the chromaticity diagram of FIG. 3, each vertex of the triangle indicates the color of each color filter of red (R), green (G), and blue (B) as a numerical value, and
The white point, which is a mixture of these three colors, is shown near the center of the triangle. Therefore, in the chromaticity diagram, the black expression color refers to the color of each of the red (R), green (G), and blue (B) color filters as shown in the chromaticity diagram of FIG. In the direction of the arrow, that is, the color of the color filter corresponding to the pixel electrode on which the colored spacers are scattered and the color having a relationship on both sides of the white point in the chromaticity diagram.

The liquid crystal display of the present invention includes any of the following three embodiments. (1) As the colored spacer, one of those having a black color development color for each of red (R), green (G), and blue (B) is used, and one type of the colored spacer is included in the colored spacer. A liquid crystal display device that is scattered on pixel electrodes corresponding to a color filter that is a black color development color. (2) Two types of colored spacers are used among those having a black color development color for each of red (R), green (G) and blue (B), and the two types of colored spacers are included in the colored spacers A liquid crystal display device which is scattered on pixel electrodes corresponding to a color filter which is a black color development color. (3) The colored spacer has a black developing color for each of red (R), green (G), and blue (B).
A liquid crystal display device in which three types of colored spacers are used, and three types of colored spacers are scattered on pixel electrodes corresponding to a color filter that is a black color development color with respect to the color of the colored spacers.

In the liquid crystal display device of the present invention, the dispersion of the colored spacers is performed by applying a DC voltage having a polarity opposite to the charging polarity of the colored spacers to a pixel corresponding to a color filter which is a black developing color with respect to the color of the colored spacers. Performed while applying to the electrode, or performed while applying a DC voltage having a polarity opposite to the charging polarity of the colored spacer to a pixel electrode corresponding to a color filter that is a black color development color with respect to the color of the colored spacer, and It can be manufactured by applying a DC voltage having the same polarity as the charged polarity of the colored spacer to a pixel electrode corresponding to a color filter that is not a black color developing color with respect to the color of the colored spacer.

As shown in FIG. 1, the colored spacers can be dispersed by spraying an appropriate amount with compressed air or the like. When the colored spacer is made of a synthetic resin or the like during the spraying, the colored spacer is frictionally charged between the spacers, compressed air, a container wall, a pipe wall, and the like, and is usually negatively charged. Therefore, when a negative voltage of the same polarity is applied to the pixel electrode, the colored spacer is repelled by repulsion, and when a positive voltage of the opposite polarity is applied, the colored spacer is concentrated on the pixel electrode by attractive force.

In the present invention, an object is achieved by applying a DC voltage having a polarity opposite to the charged polarity of the colored spacer to a pixel electrode corresponding to a color filter which is a black color developed to the color of the colored spacer. The colored spacer is disposed on the pixel electrode. For example, when the colored spacer is negatively charged, as shown in FIGS. 5 and 6, when a positive DC voltage is applied only to the pixel electrode corresponding to the blue (B) color filter, the blue ( The colored spacer can be arranged only on the pixel electrode corresponding to the color filter of B). Further, if a DC voltage having the same polarity as the charging polarity of the colored spacer is applied to a pixel electrode corresponding to a color filter that is not a black color developing color with respect to the color of the colored spacer, the arrangement of the colored spacer is performed. Selectivity can be further improved.

In the method of manufacturing a liquid crystal display device according to the present invention, the colored spacers may be sprayed not only once but also twice or three times. In other words, when the two types of colored spacers are used, the two types of colored spacers are sprayed once, for each of the two types of colored spacers, two times in total. Each of the two types of colored spacers can be arranged on a pixel electrode corresponding to a color filter having a black color for each of the above. When the three types of colored spacers are used, the three types of colored spacers are sprayed once for each of the three types of colored spacers, three times in total. Each of the above three types of colored spacers can be arranged on a pixel electrode corresponding to a color filter having a black color development color for each of the above.

The liquid crystal display device of the present invention may have a structure in which the pixel electrode and the color filter are arranged on the same substrate, or a structure in which the pixel electrode and the color filter are arranged on different substrates. May be used. Therefore, in the method of manufacturing a liquid crystal display device of the present invention, a color filter may be provided on the first substrate having the pixel electrodes on which the colored spacers are scattered, and the pixel on which the colored spacers are scattered may be provided. A color filter may be provided on a second substrate that is arranged to face the first substrate having electrodes.

Since green has high visibility, various defects are often noticeable when the colored spacer is arranged in the green pixel portion. Therefore, in the method of manufacturing a liquid crystal display device of the present invention, red or blue is used. Alternatively, it is preferable to dispose the colored spacers in both pixel portions because the display quality is improved.

In the method of manufacturing a liquid crystal display device according to the present invention, the voltage may be applied to the pixel electrode directly from a power source, but as shown in FIG. 7, the voltage is indirectly applied using a conductive stage. May be. In this case, the surface of the glass has the same polarity as the conductive stage due to the electrostatic induction.

The substrate used in the present invention is not particularly limited, and examples thereof include a glass substrate and a film substrate made of a synthetic resin or the like. The voltage applied in the present invention is preferably several tens to several hundreds of volts.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

(Examples) Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A STN substrate formed by forming a stripe-shaped ITO electrode (line width: 100 μm, spacing: 20 μm) as a transparent electrode on a glass substrate, forming an alignment film of polyimide, and performing a rubbing treatment is shown in FIG. As shown in FIG. 1, it was installed in the container body 11, and a voltage application device 13 was connected so that a DC voltage could be arbitrarily applied to all the transparent electrodes. (R of the color filter
The stripe direction of the GB pixel matches the stripe-shaped ITO electrode direction, and each of the ITO lines corresponds to an RGB pixel. )

As a spacer, an organic pigment is dispersed in a monomer of divinylbenzene, tetramethylolmethanetetraacrylate, and acrylonitrile, polymerized and classified, thereby forming a cyan, yellow, and magenta colored particle having a particle size of 6.0 μm. A spacer was prepared.

An appropriate amount of the yellow spacer was charged into the spacer blow-out tube 12 and sprayed on the substrate with 1.5 kgf / cm ² of compressed air. While spraying the spacer, a DC voltage of +500 V is applied to the pixel electrode corresponding to blue,
A DC voltage of -500 V was applied to the pixel electrodes corresponding to red and green. When the scattered substrate was superimposed on the color filter substrate and the arrangement of the scattered yellow spacers was observed with a transmission optical microscope, it was arranged only on the blue pixels, and no light leaked from the spacer portion. , Was observed as black.

Example 2 A substrate was placed in close contact with a stage made of A1 and a DC voltage of +500 V was applied to a pixel electrode corresponding to blue, and a DC voltage of -500 V was applied to a stage made of A1. The same operation as in Example 1 was performed. When the scattered substrate was superimposed on the color filter substrate and the arrangement of the scattered yellow spacers was observed with a transmission optical microscope, it was arranged only on the blue pixels, and no light leaked from the spacer portion. , Was observed as black.

Example 3 By the same operation as in Example 1, a DC voltage of +500 V was applied to the pixel electrode corresponding to red while a cyan spacer was being sprayed as the first color, and green and blue were applied. A DC voltage of -500 V was applied to the corresponding pixel electrode. next,
As a second color, a DC voltage of +500 V is applied to a pixel electrode corresponding to blue while spraying a yellow spacer,
A DC voltage of -500 V was applied to the pixel electrodes corresponding to red and green. The scattered substrate was superimposed on the color filter substrate, and the arrangement of the scattered cyan and yellow spacers was observed with a transmission optical microscope.
The cyan spacer was disposed only on the red pixel, and the yellow spacer was disposed only on the blue pixel. Light was not leaked from the spacer portion, and the pixel was observed as black.

Embodiment 4 First, a DC voltage of +500 V is applied to a pixel electrode corresponding to red while a cyan spacer is being sprayed as the first color by the same operation as in Embodiment 1, and green and blue are applied. A DC voltage of -500 V was applied to the corresponding pixel electrode. next,
As a second color, a DC voltage of +500 V is applied to the pixel electrode corresponding to green while spraying magenta spacers,
A DC voltage of -500 V was applied to the pixel electrodes corresponding to red and blue. Further, as a third color, a DC voltage of +500 V is applied to the pixel electrode corresponding to blue while spraying a spacer of yellow color, and −50 is applied to the pixel electrode corresponding to red and green.
A DC voltage of 0 V was applied. The scattered substrate was superimposed on the color filter substrate, and the arrangement of the scattered cyan, magenta, and yellow spacers was observed with a transmission optical microscope.As a result, the cyan spacer appeared only on the red pixels. The magenta spacer was disposed only on the green pixel, and the yellow spacer was disposed only on the blue pixel. Light was not leaked from the spacer portion, and the pixel was observed as black.

Comparative Example 1 A mask having stripe-shaped openings (80 μm × 400 μm openings arranged in a stripe pattern (longitudinal direction) at an interval of 30 μm) corresponding to one color interval of the substrate of Example 1 was prepared. After the mask was mounted on the substrate manufactured in the same manner as in Example 1, alignment was performed so that the opening portion matched the region of the blue pixel on the substrate. Next, in this state, the squeegee is moved in a certain direction while pressing the mask with a squeegee (applicator) used for screen printing,
After applying the same yellow spacer as in Example 1, the mask was removed. When the sprayed substrate was observed with a microscope, scratches due to the alignment of the mask and further pressing with a squeegee were observed on the alignment film. In addition, many aggregations were observed in the yellow spacer. Further, compared to the embodiment, much time was required for alignment and the like.

Comparative Example 2 By the same operation as in Example 1, a DC voltage of +500 V was applied to the pixel electrode corresponding to blue while a colorless spacer was being sprayed, and -500 V was applied to the pixel electrodes corresponding to red and green. DC voltage was applied. When the scattered substrate was superimposed on the color filter substrate and the arrangement of the scattered colorless spacers was observed with a transmission optical microscope, it was arranged only on the blue pixels, but light leaked from the spacer portion, Like the pixel, it was observed blue.

Comparative Example 3 By the same operation as in Example 1, a DC voltage of +500 V was applied to the pixel electrode corresponding to green while the yellow spacer was being sprayed, and -500 V was applied to the pixel electrodes corresponding to blue and red. Was applied. When the scattered substrate was superimposed on the color filter substrate and the arrangement of the scattered yellow spacers was observed with a transmission optical microscope, it was arranged only on the green pixels. , A yellow-green color was observed.

[0031]

The liquid crystal display device of the present invention is as described above, so that light leakage from the spacer portion is prevented, the contrast is high, and the display quality is excellent. According to the method of manufacturing a liquid crystal display device of the present invention,
Spacers can be selectively and efficiently arranged on specific pixel electrodes, and a liquid crystal display device with good display quality can be efficiently obtained in a short time. Further, when the thickness of the RGB pixels is different, the thickness (gap) of the liquid crystal layer can be maintained with higher accuracy than the conventional random arrangement by selectively disposing the spacers on the pixels. Is possible.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for explaining a method of manufacturing a liquid crystal display device according to an embodiment.

FIG. 2 is a conceptual sectional view of a conventional liquid crystal display device.

FIG. 3 is a chromaticity diagram (CIE chromaticity diagram) of a color filter.

FIG. 4 is a chromaticity diagram (CIE chromaticity diagram) for explaining the relationship between the color of a color filter and the color of a colored spacer.

FIG. 5 is a diagram showing a state in which colored spacers are arranged only on pixel electrodes corresponding to blue (B) color filters.

FIG. 6 is a cross-sectional view showing a state where a colored spacer is arranged only on a pixel electrode corresponding to a blue (B) color filter.

FIG. 7 is a cross-sectional view showing a state where a colored spacer is arranged on a specific pixel electrode by indirect voltage application.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Polarizing plate 3 Transparent electrode 4 Color filter 5 Black matrix 6 Overcoat 7 Liquid crystal 8 Spacer 9 Alignment film 10 Conductive stage 11 Container main body 12 Spacer blowing pipe 13 Voltage applying device

Claims (7)

[Claims] 1. A spacer is scattered on a first substrate having pixel electrodes corresponding to red (R), green (G) and blue (B) color filters, and a second substrate is scattered thereon. And a liquid crystal display device in which a liquid crystal is injected into a gap between the spacers, wherein the spacer is a colored spacer having a black color development color for a color filter corresponding to a pixel electrode on which the spacer is dispersed. Characteristic liquid crystal display device. 2. A color spacer having one of black color development colors for red (R), green (G), and blue (B) is used, and one type of the color spacer is the color spacer. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is scattered on pixel electrodes corresponding to a color filter that is a black color development color with respect to the color of the color filter. 3. The color spacers include two types of color spacers having a black color development color for each of red (R), green (G), and blue (B), and two types of the color spacers are the color spacers. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is scattered on the pixel electrodes corresponding to the color filters that are black color development colors with respect to the color of the liquid crystal. 4. A colored spacer having three types of colors having a black expression color for each of red (R), green (G) and blue (B) is used, and the three types of colored spacers are 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is scattered on each of the pixel electrodes corresponding to the color filters that are black color development colors with respect to the color. 5. The manufacturing method for manufacturing a liquid crystal display device according to claim 2, wherein the dispersion of the colored spacer is performed by applying a DC voltage having a polarity opposite to a charging polarity of the colored spacer to the color of the colored spacer. It is performed while applying to a pixel electrode corresponding to a color filter that is a black color developing color, or a DC voltage having a polarity opposite to the charging polarity of the color spacer, a color filter that is a black color developing color with respect to the color of the color spacer. While applying a DC voltage having the same polarity as the charged polarity of the colored spacer to a pixel electrode corresponding to a color filter that is not a black color development color with respect to the color of the colored spacer. A method for manufacturing a liquid crystal display device. 6. A method for manufacturing a liquid crystal display device according to claim 3, wherein the two types of colored spacers are dispersed by one for each of the two types of colored spacers.
Each of the two times of spraying of the spacer is performed by applying a DC voltage having a polarity opposite to the charging polarity of the colored spacer to a pixel corresponding to a color filter which is a black color development color with respect to the color of the colored spacer. Performing while applying to the electrode, or while applying a DC voltage having a polarity opposite to the charging polarity of the colored spacer to the pixel electrode corresponding to the color filter that is a black color development color with respect to the color of the colored spacer, and And applying a DC voltage having the same polarity as the charged polarity of the colored spacer to a pixel electrode corresponding to a color filter that is not a black developing color with respect to the color of the colored spacer. . 7. A method for manufacturing a liquid crystal display device according to claim 4, wherein the three types of colored spacers are dispersed by one for each of the three types of colored spacers.
Each of the three times of dispersing the spacer is performed by applying a DC voltage having a polarity opposite to the charging polarity of the colored spacer to a pixel corresponding to a color filter which is a black color development color with respect to the color of the colored spacer. Performing while applying to the electrode, or while applying a DC voltage having a polarity opposite to the charging polarity of the colored spacer to the pixel electrode corresponding to the color filter that is a black color development color with respect to the color of the colored spacer, and And applying a DC voltage having the same polarity as the charged polarity of the colored spacer to a pixel electrode corresponding to a color filter that is not a black developing color with respect to the color of the colored spacer. .