JPH10339878A - Manufacturing method for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To selectively and efficiently arrange spacers at specific pixel electrode parts by applying the DC voltage having the same polarity as that of the electrification of spacers only on the pixel electrode part of green or on the pixel electrode part of green and either red or blue at the time of dispersing light shielding spacers. SOLUTION: A substrate 1 on which stripe shaped ITO electrodes are formed and stripe shaped color filters are formed so as to be overlapped on the ITO electrodes is installed in the container main body 11 of a dispersing device and a voltage applying device 13 (DC power source) is connected so as to be able to arbitrarily apply voltages on ITO electrodes respectively corresponding to parts of red, green, blue of color filters. Then, light shielding spacers 8 are dispersed on the substrate 1 by compressed air while putting the spacers 8 into a spouting pipe 12. At the time of this dispersion, the DC voltage having the same polarity as that of the electrification of the spacers 8 is applied only on the pixel electrode part of green or on the pixel electrode part of green and either red or blue.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[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, as shown in FIG. 2, the display of the liquid crystal display device is performed on the pixel electrode in order to randomly and uniformly scatter spacers on the substrate on which the pixel electrode is formed. The spacer is also arranged in the portion. 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.
In addition, light leakage occurs due to the disorder of the orientation of the liquid crystal on the spacer surface, which lowers the contrast and color tone and deteriorates the display quality. Among the red, green, and blue pixel portions, green has the highest visibility, so that the influence of light leakage from the spacer is particularly large.

In order to solve the above-mentioned problem, it is necessary to dispose a spacer only in a red or blue portion, which is inferior to green in luminosity. From such a concept, Japanese Patent Laid-Open No.
No. 8919 discloses that a mask having an opening is arranged on a lower substrate with the positions of the opening and the blue pixel precisely aligned, and a squeegee used in screen printing is slid on the mask. A color liquid crystal panel in which a spacer is disposed only in a region on a blue pixel by a technique of attaching the spacer to the blue pixel through an opening is disclosed.
However, in such a technique, the mask comes into contact with the alignment film, which causes abnormal alignment of the liquid crystal, thereby deteriorating the display quality. In addition, there is a problem that time is required for positioning and the like, and productivity is reduced.

[0005]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a method of manufacturing a liquid crystal display device in which spacers can be selectively and efficiently arranged at specific pixel electrode portions.

[0006]

According to the present invention, a spacer is scattered on a first substrate having red (R), green (G), and blue (B) pixel electrode portions and a color filter.
A method for manufacturing a liquid crystal display device, comprising: disposing a second substrate on the second substrate, and injecting a liquid crystal into a gap between the second substrate and the spacer, wherein the spacer is a light-shielding spacer, and when the spacer is dispersed, the spacer is charged. A DC voltage having the same polarity as the polarity is applied to only the green (G) pixel electrode portion, or the green (G) pixel electrode portion and the red (R) pixel electrode portion or the blue (B) pixel electrode portion. This is a method for manufacturing a liquid crystal display device in which a voltage is applied to one of pixel electrode portions. Hereinafter, the present invention will be described in detail.

In the present invention, spacers are scattered on a first substrate having respective pixel electrode portions of red (R), green (G), and blue (B) and a color filter, and a second substrate is formed thereon. Are opposed to each other, and liquid crystal is injected into the gap.

The spacer used in the present invention is a light-shielding spacer. When a spacer made of a synthetic resin or glass is disposed on the pixel electrode, the spacer portion causes light leakage due to the depolarizing effect. In this case, if the spacer absorbs such light, no light leaks. Therefore, the spacer needs to be light-shielding. The light-shielding spacer can be obtained by dispersing a pigment in a raw material such as a monomer when producing a spacer made of a synthetic resin. Also, it can be obtained by dyeing or the like. From such a viewpoint, in the present invention, a light-shielding spacer made of a synthetic resin is particularly preferable.

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

In the present invention, as shown in FIGS. 3 and 4, a DC voltage having the same polarity as the charging polarity of the spacer is applied only to the green (G) pixel electrode portion, so that the green (G) pixel electrode portion is not applied. Spacers can be arranged in the pixel electrode portions of the above. At this time, by applying a DC voltage having a polarity opposite to that of the spacer to the red (R) pixel electrode portion and the blue (B) pixel electrode portion, it is possible to further enhance the selectivity of the spacer arrangement. it can.

As shown in FIGS. 5 and 6, a spacer is provided on one of the green (G) pixel electrode portion and the red (R) pixel electrode portion or the blue (B) pixel electrode portion. By applying a DC voltage having the same polarity as the charging polarity, the spacers can be arranged in the remaining one color pixel electrode portion. At this time, by applying a voltage having a polarity opposite to the charged polarity of the spacer to the pixel electrode portion of the remaining one color, the selectivity of the arrangement of the spacer can be further improved.

In the present invention, the voltage may be applied to the electrodes directly from a power supply, but may be applied indirectly using a conductive stage as shown in FIG. 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.

In the present invention, of the red, green, and blue pixels of the liquid crystal display device, the spacer can be arranged in a pixel other than the green pixel in which light leakage of the spacer is most visible from the viewpoint of luminosity. The use of the spacer eliminates light leakage at the spacer portion, so that a liquid crystal display device with good display quality can be obtained. In the present invention,
The spacers can be selectively arranged in a short time without contact without damaging the alignment film or the like. Furthermore, when the thicknesses of the red, green and blue pixels of the color filter are different, for example,
By arranging the spacers selectively on the pixels, the thickness (gap) of the liquid crystal layer can be maintained with higher accuracy than in the random arrangement.

[0015]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A striped ITO electrode (line width 80 μm) was formed on a glass substrate.
m, an interval of 15 μm), and a stripe-shaped color filter (R: red, G:
Green, B: blue), a resin black matrix is further formed, an overcoat layer and a polyimide alignment film are sequentially formed thereon, and then a rubbing process is performed.
A substrate (STN substrate) was obtained. This substrate is placed in the container body 11 of the spraying device as shown in FIG. 1, and a voltage is applied so that a voltage can be arbitrarily applied to each of the ITO electrode portions corresponding to the RGB portions of the color filter. The device 13 (DC power supply) was connected.

An appropriate amount of a light-shielding spacer (particle size: 6 μm, Micropearl BB, manufactured by Sekisui Fine Chemical Co., Ltd.) was charged into the spacer blowing tube 12 and sprayed on the substrate by compressed air of 1.5 kgf / cm ² . During spraying, a DC voltage of -600 V was applied to the pixel electrode portion corresponding to green. Observation with a microscope of the arrangement of the scattered light-shielding spacers revealed that 90% or more of the light-shielding spacers were arranged on red and blue pixels other than green.

Example 2 During spraying, the pixel electrode portion corresponding to green was applied with -300 V, red,
The same operation as in Example 1 was performed except that a DC voltage of +600 V was applied to a pixel electrode portion corresponding to blue. When the arrangement state of the scattered light shielding spacers was observed with a microscope,
Almost 100% of the light shielding spacers were arranged on the red and blue pixels other than green.

Example 3 During spraying, a pixel electrode portion corresponding to green and red was applied with -300 V
The same operation as in Example 1 was performed except that a DC voltage of +600 V was applied to a pixel electrode portion corresponding to blue. When the arrangement state of the scattered light shielding spacers was observed with a microscope,
Almost 100% of the light-shielding spacers were arranged only on the blue pixels.

Example 4 A substrate was placed in close contact with an aluminum stage.
The same operation as in Example 1 was performed except that a DC electrode of +600 V was applied to the pixel electrode portion corresponding to blue, and a -600 V DC electrode was applied to the aluminum stage. When the arrangement state of the scattered light-shielding spacers was observed with a microscope, almost 100% of the light-shielding spacers were arranged only on the blue pixels.

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 the 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 light-blocking 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 light shielding spacer. Further, as compared with Examples 1 to 4, much time was required for alignment and the like.

[0022]

Since the method of manufacturing the liquid crystal display device of the present invention is as described above, the spacer can be selectively and efficiently arranged at a specific pixel electrode portion, and the display quality is good. Can be obtained.

[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 diagram showing a state where spacers are arranged on pixel electrode portions of two colors other than green.

FIG. 4 is a cross-sectional view showing a state where spacers are arranged on pixel electrode portions of two colors other than green.

FIG. 5 is a diagram showing a state in which a spacer is arranged on a blue pixel electrode portion.

FIG. 6 is a cross-sectional view showing a state where a spacer is arranged on a blue pixel electrode portion.

FIG. 7 is a cross-sectional view showing a state where spacers are arranged on pixel electrode portions of one color 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 (1)

[Claims] 1. A spacer is scattered on a first substrate having red (R), green (G), and blue (B) pixel electrode portions and a color filter, and a second substrate is formed thereon. A method for manufacturing a liquid crystal display device, comprising a liquid crystal display device in which liquid crystal is injected into a gap between the spacers, wherein the spacer is a light-shielding spacer, and when the spacers are dispersed, a DC voltage having the same polarity as the charged polarity of the spacers is applied. , Or only to the green (G) pixel electrode portion, or to the green (G) pixel electrode portion and either the red (R) pixel electrode portion or the blue (B) pixel electrode portion. A method for manufacturing a liquid crystal display device, comprising applying a voltage.