JP2000275654A - Liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal display device, showing uniform brightness in the display screen, which is improved contrast and luminance which displays high-quality images while preventing generation of cross talk by forming columnar spacers each containing uniform density of particles, having a size which is almost the same as the thickness of the liquid crystal layer formed between a pair of substrates which constitute the liquid crystal panel. SOLUTION: Columnar spacers SP are formed on at least one of a pair of substrates. Each columnar spacer SP consists of a resin PRS containing particles RU having a size almost the same as the cell gap. The particles RU are made of spherical, spheroidal or short fiber type silica beads, polymer beads or the like. Thereby, even when the height of the resin which constitutes the columnar spacers SP is smaller than the cell gap, the desired cell gas can be maintained by the particles RU and the cell gap is made uniform. Thus, a display screen with uniform brightness can be obtd.

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, and more particularly, to a liquid crystal display device having a novel structure for keeping a distance between a pair of substrates for sealing a liquid crystal composition constituting a liquid crystal layer constant. The present invention relates to a liquid crystal display device and a method for manufacturing the same.

[0002]

2. Description of the Related Art A liquid crystal display device has been widely used as a display device capable of displaying a high-definition color image for a notebook computer or a computer monitor.

This type of liquid crystal display device basically constitutes a so-called liquid crystal panel in which a liquid crystal composition is sandwiched between at least two substrates made of transparent glass or the like at opposing gaps. A type (simple matrix type liquid crystal display device) in which a predetermined pixel is turned on and off by selectively applying a voltage to various electrodes for pixel formation formed on the substrate, and the above-mentioned various electrodes and an active element for pixel selection are formed. The active matrix type is broadly classified into a type in which predetermined pixels are turned on and off by selecting the active element (active matrix type liquid crystal display device).

An active matrix type liquid crystal display device is
Thin film transistor (TFT) as its active element
Is typical. 2. Description of the Related Art A liquid crystal display device using a thin film transistor is widely used as a monitor for a display terminal of OA equipment because it is thin and lightweight and has high image quality comparable to a cathode ray tube.

[0005] The display methods of this liquid crystal display device are roughly classified into the following two types based on the difference in the method of driving the liquid crystal. Part 1
First, the liquid crystal composition is sandwiched between two substrates each having a transparent electrode, operated by a voltage applied to the transparent electrode, and light transmitted through the transparent electrode and incident on the liquid crystal composition layer is modulated for display. Most of the products currently in wide use adopt this method.

The other is to operate a liquid crystal by an electric field formed substantially parallel to a substrate surface between two electrodes formed on the same substrate, and to enter a liquid crystal composition layer from a gap between the two electrodes. It is a method of modulating and displaying the modulated light, and has a feature that the viewing angle is extremely wide, and is a very promising method as an active matrix liquid crystal display device. The features of this method are described in, for example, Japanese Patent Publication No. 5-505247, Japanese Patent Publication No. 63-21907, and Japanese Patent Application Laid-Open No. 6-16.
No. 0878 and other documents. Hereinafter, this type of liquid crystal display device is referred to as a horizontal electric field type liquid crystal display device.

FIG. 14 is a sectional view of a principal part for explaining an electric field formed in a liquid crystal display device of a horizontal electric field type. In this liquid crystal display device, a video signal line DL, a counter electrode CT, and a pixel electrode PX are formed on one substrate SUB1 and formed at an interface with a protective film PSV and a liquid crystal composition LC layer formed thereon. Having the orientation control layer ORI1 formed. In addition, a color filter FIL partitioned by a black matrix BM on the other substrate SUB2, and a liquid crystal composition (hereinafter, also simply referred to as a liquid crystal) in which a constituent material of the color filter and the black matrix covers these upper layers and forms a liquid crystal layer LC. Overcoat layer OC formed so as not to affect
Control layer O formed at the interface with the liquid crystal LC layer
RI2.

GI and AOF on one substrate SUB1
Denotes an insulating film, the video signal line DL includes two layers of conductive films d1 and d2, the counter electrode CT includes a conductive film g1, and the pixel electrode PX includes a conductive film g2.

The distance between the pair of substrates SUB1 and SUB2 (the thickness of the liquid crystal composition layer or the interval: cell gap) is determined by dispersing spherical spacers (not shown) between the two substrates. It is common to set it to a value. Substrate S
Polarizing plates POL are respectively provided on the outer surfaces of UB1 and substrate SUB2.
1. POL2 is installed.

Although not related to the in-plane switching mode liquid crystal display device, a conical spacer is fixedly formed on the protective film of the color filter substrate instead of such a spherical spacer, or Japanese Patent Application Laid-Open No. 9-7 / 1993 describes a method in which a columnar spacer is fixedly formed by laminating color filter layers.
No. 3088 discloses this.

In the invention disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 9-73088, in the case of a spherical spacer, the contrast is reduced due to light leakage from the periphery of the spacer, and the spacer becomes uneven in the step of dispersing the spacer on the substrate. In order to solve the problem of display failure caused by being arranged, a spacer is fixedly formed on a substrate.

As a method of forming a spacer for maintaining a distance between substrates, a photosensitive sheet obtained by applying a photosensitive resin to a base film is laminated on a substrate, and a photolithography process including exposure and development through a mask is used. Is disclosed in JP-A-7-3
No. 25298. This is to make the spacer film thickness uniform to prevent color unevenness.

[0013]

There are two problems to be solved by the present invention. One of the problems is a problem in a liquid crystal display device in which a spacer is fixedly formed on a substrate. Hereinafter, the spacer formed in this manner is particularly referred to as a columnar spacer.

Since the spacer is formed for the purpose of making the cell gap uniform, it is required that the thickness of the columnar spacer be uniform. Therefore, for example, in the above-mentioned Japanese Patent Application Laid-Open No. 7-325298, a photosensitive sheet in which a photosensitive resin having a uniform thickness is previously formed on a base film is laminated on a substrate, and a columnar spacer is formed through a photolithography process.

This method is considered to be superior in the uniformity of the film thickness as compared with a method of applying a photosensitive resin to a substrate such as a spin coating method. However, in the photolithography process after laminating the photosensitive sheets, the uniformity of the in-plane distribution of the irradiation intensity of the exposure light and the in-plane non-uniformity in the developing process cause the columnar spacers in the substrate surface and in each substrate. The film thickness varies. As a result, uneven brightness occurs due to non-uniform cell gap.

In manufacturing a liquid crystal display device, the mechanical properties of the spacer are important. The substrate surface of the liquid crystal display device is not flat, and has a minute (1 μm or less) step.
Even if the spacer thickness is uniform, there is unevenness in the steps where the spacers are placed.To make the cell gap uniform, crush the spacers between the substrates or dig into the constituent layers on the substrates. I need to do it. Therefore, the columnar spacers are required to have characteristics such as elasticity and hardness as those of the spherical spacers. However, it is difficult to require a columnar spacer made of an organic substance such as a photosensitive resin to have mechanical properties equivalent to those of an inorganic spherical spacer such as glass or silica or a plastic spherical spacer.

The second problem to be solved by the present invention relates to a pixel design in a liquid crystal display device of an in-plane switching mode. As in the prior art, increasing the distance between the electrodes and increasing the optical density of the black matrix BM have the following problems.

If the distance between the video signal line DL and the counter electrode CT or the distance between the video signal line DL and the one pixel electrode PX is increased in order to reduce the electric field strength between the electrodes, the display pixel area must be narrowed. In addition, a decrease in aperture ratio causes a decrease in luminance and an increase in power consumption.

On the other hand, there are the following problems in increasing the optical density of the black matrix BM. In a horizontal electric field type liquid crystal display device, the black matrix BM needs to have high resistance (for example, Japanese Patent Application Laid-Open No. 9-43589). The electrical characteristics of the black matrix BM affect the formation of a horizontal electric field substantially parallel to the substrate,
If the resistance of M is low, an ideal horizontal electric field is not formed, and the brightness, the contrast, and the viewing angle are reduced.
And the like.

In order to increase the resistance of the black matrix BM, it is desirable to use a pigment-dispersed photosensitive resin. At this time, if the pigment concentration ratio in the photosensitive resin is increased to increase the optical density of the black matrix BM, the processability of the photolithography process deteriorates because the resin concentration decreases. Specifically, there are problems such as a decrease in resolution, a decrease in development margin, and a tendency to generate pigment residues.

When the optical density is increased by increasing the thickness of the black matrix BM, the flatness of the color filter deteriorates, and the rubbing property of the orientation control layer ORI2 and the cell gap become uniform. It becomes difficult and causes poor display quality such as deterioration of response speed.

An object of the present invention is to solve the above two problems. The first object of the present invention is to make the luminance in a display screen uniform, to reduce the aperture ratio, and to realize a relatively low optical density. It is an object of the present invention to provide a liquid crystal display device that does not cause a decrease in contrast luminance or crosstalk even when a black matrix is used.

A second object of the present invention is to provide a method for manufacturing the above liquid crystal display.

[0024]

In order to achieve the first object, the present invention provides a method for forming particles having a size substantially equal to the thickness of a liquid crystal layer formed between a pair of substrates constituting a liquid crystal panel. It is characterized in that columnar spacers containing uniform density are provided.

Typical configurations for achieving the first object of the present invention are as described in the following (1) to (3). That is, (1) a pair of substrates, at least one of which is transparent, at least two or more types of color filters having different colors for color display formed on one of the pair of substrates, and interposed between the color filters; A black matrix, an electrode group formed on the pair of substrates, a liquid crystal layer having a dielectric anisotropy between the pair of substrates, and a molecular arrangement of a liquid crystal composition forming the liquid crystal layer in a predetermined direction. A liquid crystal panel having an alignment control layer for alignment, and driving means for applying a driving voltage to the electrode group, wherein at least one of the pair of substrates has a thickness substantially equal to a desired liquid crystal layer thickness. A columnar spacer made of resin in which particles of the same size were substantially uniformly dispersed was provided.

With this configuration, a liquid crystal display device can be obtained in which the luminance in the display screen is made uniform, the contrast and the luminance are not reduced, and no crosstalk occurs.

(2) The diameter of the particles contained in the columnar spacer in (1) is smaller than the thickness of the liquid crystal layer at the center of the pixel formed between the black matrices of the liquid crystal panel.

With this configuration, it is possible to obtain a liquid crystal display device in which the luminance in the display screen is made uniform, the contrast and the luminance are not reduced, and the crosstalk is not generated without reducing the aperture ratio.

(3) The position where the dielectric constant or conductivity of the columnar spacer in (1) or (2) is higher than that of the liquid crystal composition constituting the liquid crystal layer, and the columnar spacer is hidden by the black matrix. At a part between the signal wiring and the common wiring.

With this configuration, the luminance in the display screen is made uniform, and even if a black matrix having a relatively low optical density is used without lowering the aperture ratio, the contrast and the luminance are reduced. A liquid crystal display device free of talk is obtained.

In order to achieve the second object, the present invention includes, at a uniform density, particles having a size substantially equal to the thickness of a liquid crystal layer formed between a pair of substrates constituting a liquid crystal panel. The feature is that a columnar spacer is provided.

Typical configurations for achieving the second object of the present invention are as described in the following (4) and (5). That is, (4) a pair of substrates at least one of which is transparent, at least two or more types of color filters having different colors for color display formed on one of the pair of substrates, and interposed between the color filters. A black matrix, an electrode group including a signal wiring and a common wiring formed on the other of the pair of substrates, and a dielectric anisotropy between the pair of substrates facing each other at a predetermined interval. A liquid crystal layer having and an alignment control layer for arranging the molecular arrangement of the liquid crystal layer in a predetermined direction, and at least one of the pair of substrates,
A liquid crystal panel having a columnar spacer made of a resin in which particles having a size substantially equal to the thickness of a desired liquid crystal layer are uniformly dispersed, and polarized light stacked on each of the pair of substrates with a polarizing axis crossing each other. A method for manufacturing a liquid crystal display device, comprising: a plate; and a driving unit for applying a driving voltage to the electrode group, wherein a photosensitive film having particles having a particle size substantially equal to the predetermined interval is mixed on a surface of a base film. The photosensitive resin layer side of the photosensitive transfer sheet in which the conductive resin layers are laminated is bonded to one of the substrates constituting the pair of substrates so as to face each other, and a mask having an opening pattern corresponding to a position where the columnar spacer is formed is provided. By exposing and developing the photosensitive resin layer side through and removing the unexposed portion of the photosensitive resin layer while leaving the exposed portion, particles having a size substantially equal to the thickness of the liquid crystal layer are obtained. There is formed a columnar spacer formed of substantially uniformly dispersed resins.

By using this manufacturing method, the luminance in the display screen is made uniform, the aperture ratio does not decrease, and the contrast and luminance decrease even when a black matrix having a relatively low optical density is used. A liquid crystal display device free of talk can be manufactured.

(5) A pair of substrates at least one of which is transparent, at least two or more kinds of color filters having different colors for color display formed on one of the pair of substrates, and interposed between the color filters. A black matrix, an electrode group including a signal wiring and a common wiring formed on the other of the pair of substrates, and a dielectric anisotropy between the pair of substrates facing each other at a predetermined interval. A liquid crystal layer having an alignment control layer for arranging the molecular arrangement of the liquid crystal layer in a predetermined direction; and at least one of the pair of substrates, the density of particles having a size substantially equal to a desired thickness of the liquid crystal layer. A liquid crystal panel having a columnar spacer made of a resin dispersed uniformly, a polarizing plate laminated on each of the pair of substrates with their polarization axes intersecting, and a driving voltage applied to the electrode group. A method for manufacturing a liquid crystal display device, comprising: a heat transfer resin layer formed by laminating a heat welding resin layer in which particles having a particle size substantially equal to the predetermined distance are mixed on a surface of a base film. The heat-sealing resin layer side is bonded to one of the substrates constituting the pair of substrates so as to be opposed to each other, and a portion corresponding to a position where the columnar spacer is formed on the thermal transfer sheet is selectively heated, and only the heated portion is heated. Is fused to the substrate, and the thermal transfer sheet is removed together with the non-heated portion, thereby forming a columnar spacer made of resin in which particles having a size substantially equal to the thickness of the liquid crystal layer are substantially uniformly dispersed.

By using this manufacturing method, the luminance in the display screen is made uniform, and even if a black matrix having a relatively low optical density is used without reducing the aperture ratio, the contrast and the luminance are reduced. Further, a liquid crystal display device free from crosstalk can be manufactured.

Note that the present invention is not limited to the above-described configuration, and a liquid crystal is formed by providing an electrode for pixel selection on each of a pair of substrates and forming an electric field in a direction perpendicular to the pair of substrates. It can be applied to a so-called vertical electric field type active matrix type liquid crystal display device or a simple matrix type liquid crystal display device which controls the orientation direction of a liquid crystal composition constituting a layer, and the manufacturing method needs to set other minute gaps. The present invention can be similarly applied to various types of display devices having a display.

In the present invention, various polarizations are possible without departing from the technical idea described in the claims.

[0038]

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

FIG. 1 is a plan view of a principal part schematically illustrating a configuration near a pixel of a liquid crystal panel constituting a lateral electric field type active matrix type liquid crystal display device which is a first embodiment of a liquid crystal display device according to the present invention. FIG. 2 is a cross-sectional view of a main part taken along line 1-1 ′ of FIG.

In FIGS. 1 and 2, the same reference numerals as those in FIG. 14 correspond to the same functional portions, and various electrodes and each structural film disposed between the pair of substrates SUB1 and SUB2 are the same as the columnar spacers SP. FIG. 14 is the same as FIG. 14 except for the particles RU included therein.

That is, in FIG. 1, DL is a video signal line, SD2 is a drain electrode extending from the video signal line, CL
Is a counter voltage signal line, CT is the same counter electrode as the counter voltage signal line, PX is the pixel electrode, SD1 is the same source electrode as the pixel electrode, Cstg is the storage capacitor, GL is the scanning signal line, GT
Is the same gate electrode as the scanning electrode, BM is a black matrix (indicated by the boundary of the pixel opening), TFT is a thin film transistor, SP is a columnar spacer, PRS is a resin, and RU is a particle. In FIG. 1, the hatched portion represents the region between the video signal line DL and the counter electrode CT.

In FIG. 2, SUB1 is one substrate (active matrix substrate or TFT substrate),
UB2 is the other substrate (color filter substrate), GI is a gate insulating film, PSV is a passivation layer (protective film),
ORI1 is an alignment film (alignment control layer) on one substrate side, LC
Denotes a liquid crystal layer, ORI2 denotes an alignment film (alignment control layer) on the other substrate side, OC denotes an overcoat layer (smooth layer), FIL denotes a color filter, and BM denotes a black matrix.

RU is particles contained in the resin PRS constituting the columnar spacer SP, DL (d1, d2) is a video signal line, CT (g1) is a counter electrode, PX (g2) is a pixel electrode, and AOF is aluminum. This is an insulating layer made of an oxide film.
Note that d1, d2, g1, and g2 in the parentheses indicate conductor layers for forming those wirings or electrodes.

POL1 and POL2 provided outside each of the pair of substrates SUB1 and SUB2 are polarizing plates.

The columnar spacer SP has a structure in which particles RU having substantially the same size as the cell gap are contained inside the resin PRS. The material of the particles RU may be spherical or elliptical spherical such as silica beads or polymer beads, or non-spherical (non-elliptical spherical) such as short fiber. Further, the particles are not limited to transparent particles and may be black particles.

By including the particles RU in the columnar spacer SP, even if the height of the resin portion constituting the columnar spacer SP is smaller than the cell gap, a desired cell gap is secured by the particles RU in the columnar spacer SP. it can. Therefore, the cell gap becomes uniform, and a display screen with uniform luminance can be obtained.

Further, since the mechanical properties of the particles RU are added to the mechanical properties of the columnar spacers SP, it is possible to obtain a spacer having mechanical properties similar to those obtained when a spherical spacer is used.

In this embodiment, as shown in FIG. 2, the columnar spacers SP are provided on the color filter substrate (the other substrate SUB).
Although it is formed on the 2) side, it may be formed on the active matrix substrate (one substrate SUB1) side.

As shown in FIG. 1, the columnar spacer SP is arranged so as to cover a region between the video signal line DL and the counter electrode CT (a hatched region in FIG. 1).

In the present embodiment, as shown in FIG. 1, the number of columnar spacers SP per pixel is six, and the number of particles RU included in the columnar spacers SP is seven, but this is an example. The number and the number are arbitrary. Also,
Although the six columnar spacers SP are arranged at substantially equal intervals, the present invention is not limited to this, and they may be arranged in a staggered manner or randomly.

The planar shape of the columnar spacer SP is not limited to a substantially square shape as shown, but may be other shapes, for example, a circle, an ellipse, a rhombus, or the like.

The particles RU contained in the columnar spacer SP
Is required to be one or more. When a plurality is included, it is preferable that the number is substantially uniform per unit area in the planar shape of the columnar spacer SP, and that the dispersion density is also uniform.

According to this embodiment, unwanted light leakage from the region between the video signal line DL and the counter electrode CT can be prevented.
Hereinafter, the reason will be described.

The video signal line DLLC exists only in a part between the video signal line DL and the counter electrode CT. That is, the liquid crystal layer LC exists only in a portion where there is no columnar spacer SP. Since the light transmittance changes when the liquid crystal LC is driven, if the area where the liquid crystal LC exists decreases, the area where the light transmittance changes also decreases, and the area between the video signal line DL and the counter electrode CT changes. The amount of light transmitted from the device decreases.

Therefore, the required value of the optical density of the black matrix BM can be reduced as compared with the case where there is no columnar spacer SP. Further, the columnar spacer SP
If the dielectric constant or conductivity of the liquid crystal LC is higher than that of the liquid crystal LC, an electric field is more easily formed on the columnar spacer SP than in the liquid crystal LC. Therefore, it is difficult for the liquid crystal LC to be driven by the electric field between these electrodes (between the video signal line DL and the counter electrode CT). For this reason, it becomes easy to shield light even in a portion where there is no columnar spacer SP.

Since a UV-curable photosensitive resin is generally used as the resin constituting the columnar spacer SP, it is difficult to control the above-described dielectric constant and conductivity to desired values. In the present embodiment, the electrical characteristics of the entire columnar spacer SP are controlled by using the electrical characteristics of the particles RU included in the columnar spacer SP.

When the dielectric constant and the electric conductivity of the columnar spacer SP are made higher than those of the liquid crystal, for example, carbon black or metal particles are mixed or attached to the inside or the surface of the particles RU.

Although the columnar spacer SP is formed on the color filter substrate (the other substrate SUB2) in this embodiment, the active matrix substrate (the one substrate SU) is formed.
B1) may be formed as described above.

According to the present embodiment, a liquid crystal display device for improving the contrast and brightness, preventing the occurrence of crosstalk, and displaying a high-quality image can be obtained.

FIG. 3 is a plan view schematically showing a main part of a liquid crystal display device according to a second embodiment of the present invention. is there. The same reference numerals as those in FIG. 1 correspond to the same functional parts.

This embodiment is different from the first embodiment in that a plurality of columnar spacers SP are formed between adjacent pixels, but one bank is formed between adjacent pixels. Other configurations are the same as in the first embodiment.

That is, the columnar spacer SP is formed in a bank shape in a region between the video signal line DL and the counter electrode CT located in each adjacent portion of the pixel region where the pixel electrode PX is arranged. The particles RU contained in the columnar spacers SP are uniformly dispersed so as to have substantially the same number per unit area. Further, it is desirable that the dispersion density of the particles is also uniform over the entire area of the columnar spacer SP.

According to this embodiment, unwanted light leakage from the region between the video signal line DL and the counter electrode CT can be prevented, for the same reason as described in the first embodiment.

Next, an embodiment of a method for manufacturing a liquid crystal display device according to the present invention, that is, a method for forming a columnar spacer SP will be described.

FIG. 4 is a schematic sectional view for explaining a first example of a transfer sheet for forming columnar spacers for explaining a method of manufacturing a liquid crystal display device according to the present invention.

TFS is a transfer sheet, a photosensitive transfer sheet in which a photosensitive resin layer PRS in which silica particles RU are uniformly dispersed and arranged on a base film BSF, or a silica particle RU is added to a base film BSF. It is a thermal transfer sheet in which a heat-welding resin layer TRS dispersed and arranged is laminated.

FIG. 5 is a schematic cross-sectional view for explaining a second example of a transfer sheet for forming columnar spacers for explaining a method of manufacturing a liquid crystal display device according to the present invention.

The transfer sheet TFS is made of a base film BS.
F: a photosensitive transfer sheet in which a photosensitive resin layer PRS in which silica particles RU are dispersed and arranged only at necessary portions, that is, portions where the columnar spacers SP are formed on the substrate, or silica particles RU on a base film BSF This is a thermal transfer sheet in which a heat-fusible resin layer TRS in which RUs are dispersed and arranged only at necessary locations is laminated.

FIG. 6 is a schematic sectional view for explaining a third example of a transfer sheet for forming columnar spacers for explaining a method of manufacturing a liquid crystal display device according to the present invention.

The transfer sheet TFS is made of a base film BS.
F, a photosensitive transfer sheet in which a photosensitive resin layer PRS in which silica particles RU are uniformly dispersed and arranged is disposed via a release layer SEPL, or silica particles RU are dispersed and arranged in a base film BSF. Heat-fusible resin layer TRS
Is a thermal transfer sheet laminated with a thermal adhesion preventing layer ATAL interposed therebetween.

Next, a method for manufacturing a liquid crystal display device of the present invention using the above-described transfer sheet TFS will be described.

FIG. 7 is a schematic process chart for explaining a first embodiment of a method for manufacturing a color filter substrate including a method for forming a columnar spacer using the photosensitive transfer sheet described in FIG. Processing is performed in the order of (4). That is, (1) the color filter substrate SUB2 has a thickness of 0.7 mm
Alternatively, the substrate SUB is a 1.1 mm glass substrate.
2 is coated with a black photosensitive resin, exposed through a photomask (exposure mask) having a predetermined opening pattern corresponding to the arrangement pattern of the black matrix, and developed,
By firing, a black matrix BM is formed.

Next, the same exposure, development, and baking steps as described above are repeated using photosensitive red, green, and blue resins to repeat the color filter FIL (red colored layer FIL).
(R), green colored layer FIL (G), blue colored layer FIL
(B)) are sequentially formed.

The color filter FIL thus formed
Is covered with a protective film (smooth film) OC.

Then, a photosensitive transfer sheet TFS formed by laminating a photosensitive resin layer PRS in which silica particles RU are dispersed and arranged on the base film BSF is adhered on the protective film OC. At this time, the photosensitive transfer sheet TFS is attached so that the photosensitive resin layer PRS of the photosensitive transfer sheet TFS is bonded to the protective film OC.

(2) The photosensitive resin layer PRS is covered with the protective film OC.
After that, the base film BSF is peeled off to leave only the photosensitive resin layer PRS.

(3) The photosensitive resin layer PRS is irradiated with ultraviolet rays through a photomask PMSK having an opening pattern corresponding to the position where the columnar spacer SP is to be formed (here, immediately above the black matrix BM). here,
The photosensitive resin is assumed to be a negative type in which the part irradiated with ultraviolet light is cured, but it is also possible to use a positive type photosensitive resin in which the part irradiated with ultraviolet light is removed by development. A photomask having an opening pattern corresponding to a portion other than the position where the columnar spacer SP is formed is used.

(4) After exposure, the photosensitive resin layer P is developed and exposed.
By removing the non-exposed portion of the RS and baking, the columnar spacer SP in which the silica particles RU are dispersed and formed is formed.

Although the example using the photosensitive transfer sheet shown in FIG. 4 has been described here, the manufacturing method using the photosensitive transfer sheet shown in FIG. 5 or 6 is the same. However, when the photosensitive transfer sheet of FIG. 5 is used, the position where the columnar spacer SP is formed and the position where the particles RU are dispersed on the photosensitive transfer sheet must be aligned. When the photosensitive transfer sheet shown in FIG. 6 is used, the photosensitive resin layer PR
After sticking S to the protective film OC, the operation of peeling the base film BSF becomes easy.

According to this embodiment, the mechanical strength of the columnar spacer for making the cell gap uniform can be improved, and such a columnar spacer can be formed accurately and easily.

FIG. 8 is a schematic process diagram for explaining a second embodiment of a method for manufacturing a color filter substrate including a method for forming a columnar spacer using the photosensitive transfer sheet described in FIG. 4, and is similar to FIG. Processing is performed in the order of steps (1) to (4). This embodiment differs from the first embodiment described with reference to FIG. 7 in the handling of the base film constituting the photosensitive transfer sheet. That is, (1) the color filter substrate SUB2 has a thickness of 0.7 mm
Alternatively, the substrate SUB is a 1.1 mm glass substrate.
2 is coated with a black photosensitive resin, exposed through a photomask (exposure mask) having a predetermined opening pattern corresponding to the arrangement pattern of the black matrix, and developed,
By firing, a black matrix BM is formed.

Next, using the photosensitive red, green, and blue resins, the same exposure, development, and baking steps as described above are repeated to repeat the color filter FIL (red colored layer FIL).
(R), green colored layer FIL (G), blue colored layer FIL
(B)) are sequentially formed.

The color filter FIL thus formed
Is covered with a protective film (smooth film) OC.

Then, a photosensitive transfer sheet TFS formed by laminating a photosensitive resin layer PRS in which silica particles RU are dispersed and arranged on the base film BSF is adhered on the protective film OC. At this time, the photosensitive transfer sheet TFS is attached so that the photosensitive resin layer PRS of the photosensitive transfer sheet TFS is bonded to the protective film OC. This step is the same as in the embodiment of FIG.

(2) The photosensitive resin layer PRS is covered with the protective film OC.
, The base film BSF is not peeled off and is left as it is.

(3) A photomask PMSK having an opening pattern corresponding to the position where the columnar spacer SP is to be formed (here, immediately above the black matrix BM) is laminated on the base film BSF of the photosensitive transfer sheet TFS. Resin layer PRS photosensitive through PMSK
Is irradiated with ultraviolet light. Note that, here, the photosensitive resin is assumed to be a negative type in which a part irradiated with ultraviolet light is cured, but a positive type photosensitive resin in which the part irradiated with ultraviolet light is removed by development may be used. Is as described above.

In the embodiment described with reference to FIG. 7, it is necessary to hold the photomask PMSK at a predetermined interval with respect to the photosensitive resin layer PRS by some means, but in this embodiment, the photomask PMSK is directly mounted on the base film BSF. By adopting the method of laminating the mask PMSK, the base film B
By changing the thickness of the SF, the distance between the photomask PMSK and the photosensitive resin layer PRS can be accurately set.

(4) After the exposure, the base film BSF is peeled off, the unexposed portion of the photosensitive resin layer PRS is removed by development, and the resultant is baked, whereby the columnar spacers SP in which the silica particles RU are dispersed and arranged are formed. It is formed.

The columnar spacers SP can be formed in the same steps when the photosensitive transfer sheet shown in FIG. 5 or FIG. 6 is used.

According to the present embodiment, the mechanical strength of the columnar spacer for making the cell gap uniform can be improved, and such a columnar spacer can be formed accurately and easily.

FIG. 9 is a schematic process diagram for explaining a third embodiment of a method for manufacturing a color filter substrate including a method for forming a columnar spacer using the thermal transfer sheet described in FIG. In this embodiment, a black matrix BM and a three-color color filter FIL (FIL
(R), FIL (G), FIL (B)) and the steps of forming the overcoat layer OC are the same as those in the above-described embodiments, and thus illustration and description are omitted.

In step (1) of FIG. 9, the color filter substrate SUB on which the color filters and the like are formed as described above
The thermal transfer sheet TTFS is attached to the overcoat layer OC of No. 2. This thermal transfer sheet TTFS is made of silica particles RU.
Adhesive resin TRS in which is dispersed the base film B
The heat-fusible resin TRS side is placed facing the overcoat layer OC.

Then, the thermal head TH is heated from the side of the base film BSF at the position where the columnar spacer is formed. In this embodiment, the color filter substrate S
A method is adopted in which the UB2 is fixed and the thermal head TH is moved as indicated by the arrow in the figure to sequentially heat the positions at which the columnar spacers are formed. However, the thermal head TH is fixed, and the thermal transfer sheet TTFS and the collar are fixed. The filter substrate SUB2 may be moved. in this case,
By adjusting the feed amount of the thermal transfer sheet TTFS, FIG.
(2), it is possible to prevent generation of the residue of the heat-welding resin TRS.
This is preferable from the viewpoint of reducing the material cost of FS.

The heating is not limited to the thermal head, and a method of irradiating a predetermined portion with heating radiation such as a laser beam may be adopted.

In this step, the thermal welding resin TRS at the position where the columnar spacers of the thermal transfer sheet TTFS are formed is fused to the overcoat OC.

After the heat-welding resin TRS at the columnar spacer forming position is fused to the overcoat OC, (2) the thermal transfer sheet TTFS is peeled off from the color filter substrate SUB2 to form the columnar spacer SP.

According to this embodiment, since the photolithography process as in the method described with reference to FIG. 7 or FIG. 8 is not required, the process of forming the columnar spacer SP is simplified.

In the embodiment shown in FIG. 9, the thermal transfer sheet shown in FIG. 4 is used as the transfer sheet.
Can be used in the same manner as described above.

On the other hand, the active matrix substrate SUB1
Can be manufactured by a process similar to a known thin film transistor forming process. This active matrix substrate S
A glass substrate having a thickness of 0.7 mm or 1.1 mm is used as UB1, and a thin film transistor TFT made of amorphous silicon AS, a storage capacitor Cstg and a pixel electrode PX, a source electrode SD1, and a counter electrode are formed by repeating film formation and patterning on this substrate. A plurality of video signal lines DL for forming a CT electrode group and applying a predetermined voltage to the electrode group via a thin film transistor TFT, and a drain electrode SD
2. Counter voltage signal line CL and thin film transistor TFT
Scanning signal lines GL and gate electrodes G for controlling the conduction of
T is formed in a lattice shape.

The thin film transistor TFT, each electrode group and each wiring are covered with an insulating film GI and a protective film PSV. Thereafter, an alignment film material is applied and baked, and a liquid crystal alignment control ability is imparted by a rubbing process or a photo alignment process to form an alignment control layer ORI1.

The active matrix substrate SUB1 manufactured as described above and the color filter substrate SUB2 manufactured in the above embodiment are opposed to each other, and the periphery thereof is fixed with an adhesive except for a liquid crystal sealing opening. The liquid crystal composition is sealed in the opening, and the liquid crystal filling opening is sealed with a sealant.

Thereafter, the distance between the two substrates is regulated by a columnar spacer by pressing to obtain a liquid crystal display device having a predetermined cell gap.

Next, the driving means of the liquid crystal display device to which the present invention is applied and specific examples of products will be described.

FIG. 10 is a schematic explanatory view of driving means of a liquid crystal display device to which the present invention is applied. The liquid crystal display device is constituted by a set of a plurality of pixels in which an image display section is arranged in a matrix. Is configured to independently control the modulation of transmitted light from a backlight (not shown) arranged at the back of the liquid crystal display device.

On the active matrix substrate (SUB1), which is one of the components of the liquid crystal display substrate, the active pixel region AR extends in the x direction (row direction) and the y direction (column direction).
The video signal lines DL which are insulated from the scanning signal lines GL and the counter voltage signal lines CL and extend in the y direction and are arranged in the x direction are formed.

Here, a unit pixel is formed in a rectangular area surrounded by each of the scanning signal line GL, the counter voltage signal line CL, and the video signal line DL.

The liquid crystal display device is provided with a vertical scanning circuit V and a video signal driving circuit H as external circuits, and the vertical scanning circuit V sequentially supplies a scanning signal (voltage) to each of the scanning signal lines GL. The video signal drive circuit H supplies a video signal (voltage) to the video signal line DL in accordance with the timing.

The vertical scanning circuit V and the video signal driving circuit H are supplied with power from the liquid crystal driving power supply circuit 3 and input image information from the CPU 1 after being divided into display data and control signals by the controller 2 respectively. It is supposed to be.

FIG. 11 is an explanatory diagram of an example of a driving waveform of a liquid crystal display device to which the present invention is applied. In the figure, the opposite voltage is a binary AC rectangular wave of VCH and VCL, and the non-selection voltages of the scanning signals VG (i-1) and VG (i) are synchronized with the rectangular waveform of VCH and VCL every scanning period. Is changed in two values. The amplitude width of the counter voltage and the amplitude value of the non-selection voltage are the same.

The video signal voltage is a voltage obtained by subtracting 振幅 of the amplitude of the counter voltage from the voltage to be applied to the liquid crystal layer.

The counter voltage may be DC, but by converting it to AC, the maximum amplitude of the video signal voltage can be reduced, and a video signal drive circuit (signal side driver) having a low withstand voltage can be used.

FIG. 12 is an exploded perspective view for explaining the entire structure of the liquid crystal display device according to the present invention. The liquid crystal display device (hereinafter, a liquid crystal panel formed by bonding two substrates SUB1 and SUB2, driving means, and a backlight) , A liquid crystal display module integrating other components: MDL)
This is to explain the specific structure of the above.

SHD is a shield case (also called a metal frame) made of a metal plate, WD is a display window, INS1
3 to 3 are insulating sheets, PCBs 1 to 3 are circuit boards constituting driving means (PCB 1 is a drain side circuit board: a circuit board for driving a video signal line, PCB 2 is a gate side circuit board, PCB
3 is an interface circuit board), JN1 to 3 are joiners for electrically connecting the circuit boards PCB1 to PCB3, TC
P1 and TCP2 are tape carrier packages, PNL is a liquid crystal panel, GC is a rubber cushion, ILS is a light shielding spacer, PRS is a prism sheet, SPS is a diffusion sheet,
GLB is a light guide plate, RFS is a reflection sheet, MCA is a lower case (mold frame) formed by integral molding, MO is an MCA opening, LP is a fluorescent tube, LPC is a lamp cable, and GB supports a fluorescent tube LP. A rubber bush, BAT denotes a double-sided adhesive tape, BL denotes a backlight made of a fluorescent tube, a light guide plate, and the like, and a liquid crystal display module MDL is assembled by stacking diffusion plate members in the arrangement shown in the figure.

The liquid crystal display module MDL has two kinds of storage / holding members of a lower case MCA and a shield case SHD, and includes insulating sheets INS1 to INS3 and circuit boards PCB1 to PCB1.
3. A metal shield case SHD in which a liquid crystal panel PNL is stored and fixed, and a lower case MCA in which a backlight BL including a fluorescent tube LP, a light guide plate GLB, a prism sheet PRS, and the like are stored are combined.

An integrated circuit chip for driving each pixel of the liquid crystal panel PNL is mounted on the video signal line driving circuit board PCB1, and an interface circuit board PCB3
Is mounted with an integrated circuit chip that receives a video signal from an external host, receives a control signal such as a timing signal, and a timing converter TCON that processes timing to generate a clock signal.

The clock signal generated by the timing converter is integrated on the video signal line driving circuit board PCB1 via the clock signal line CLL laid on the interface circuit board PCB3 and the video signal line driving circuit board PCB1. Supplied to the circuit chip.

The interface circuit board PCB3 and the video signal line driving circuit board PCB1 are multilayer wiring boards, and the clock signal line CLL is connected to the interface circuit board PCB3 and the video signal line driving circuit board PC
It is formed as an inner wiring of B1.

The liquid crystal panel PNL has a drain-side circuit board PCB1, a gate-side circuit board PCB2, and an interface circuit board PCB3 for driving TFTs.
Are connected by tape carrier packages TCP1 and TCP2, and the circuit boards are connected by joiners JN1, JN2, JN3.

The liquid crystal panel PNL is an in-plane switching type active matrix type liquid crystal display device according to the present invention described above. In order to maintain the distance between the two substrates at a predetermined value, the columnar structure containing particles described in the above embodiment is used. It has a spacer.

FIG. 13 is a perspective view of a notebook computer as an example of an electronic device on which the liquid crystal display device according to the present invention is mounted.

This notebook computer (portable personal computer) is composed of a keyboard section (main body section) and a display section connected to the keyboard section by a hinge. Keyboard and host (host computer), CP
U and other signal generation functions, and the display unit has a liquid crystal panel P
NL, and drive circuit boards PCB1 and PCB
2, PCB3 with control chip TCON,
In addition, an inverter power supply board serving as a backlight power supply is mounted.

The liquid crystal display module described with reference to FIG. 12 in which the liquid crystal display panel PNL, the various circuit boards PCB1, PCB2, PCB3, the inverter power supply board, and the backlight are integrated is mounted.

In the above embodiment, the configuration in which the present invention is applied to a so-called horizontal electric field type liquid crystal display device has been described.
The present invention is not limited to this, and it goes without saying that the present invention can be similarly applied to other liquid crystal display devices that need to keep the cell gap uniform at the point where particles are mixed into the spacer.

[0124]

As described above, according to the present invention,
The cell gap in the display screen is made uniform by the columnar spacer arranged between the video signal line and the counter electrode or so as to cover the area of the video signal line and the pixel electrode and the particles therein having the same size as the cell gap. Thus, the luminance in the display screen becomes uniform.

Further, since the liquid crystal in the region between the electrodes is partially excluded, the transmitted light in the region between the electrodes is hardly affected by the electric field formed between the electrodes.

Therefore, the amount of light leakage in the region is reduced, the contrast and brightness are improved, the occurrence of crosstalk is prevented, and a liquid crystal display device for displaying a high quality image is obtained.

[Brief description of the drawings]

FIG. 1 is a main part plan view schematically illustrating a configuration near a pixel of a liquid crystal panel constituting a lateral electric field type active matrix type liquid crystal display device which is a first embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a sectional view of an essential part taken along line 1-1 'of FIG.

FIG. 3 is a plan view of a principal part schematically illustrating a configuration near a pixel of a liquid crystal panel constituting a lateral electric field type active matrix type liquid crystal display device which is a second embodiment of the liquid crystal display device according to the present invention.

FIG. 4 is a schematic cross-sectional view illustrating a first example of a transfer sheet for forming columnar spacers for explaining a method of manufacturing a liquid crystal display device according to the present invention.

FIG. 5 is a schematic cross-sectional view illustrating a second example of a transfer sheet for forming columnar spacers for explaining a method of manufacturing a liquid crystal display device according to the present invention.

FIG. 6 is a schematic cross-sectional view illustrating a third example of a transfer sheet for forming columnar spacers for explaining a method of manufacturing a liquid crystal display device according to the present invention.

FIG. 7 is a schematic process diagram illustrating a first embodiment of a method of manufacturing a color filter substrate including a method of forming a columnar spacer using the photosensitive transfer sheet described in FIG.

FIG. 8 is a schematic process diagram illustrating a second embodiment of a method of manufacturing a color filter substrate including a method of forming a columnar spacer using the photosensitive transfer sheet described in FIG.

FIG. 9 is a schematic process diagram illustrating a third embodiment of a method for manufacturing a color filter substrate including a method for forming a columnar spacer using the thermal transfer sheet described in FIG.

FIG. 10 is a schematic explanatory view of a driving unit of a liquid crystal display device to which the present invention is applied.

FIG. 11 is an explanatory diagram of an example of a driving waveform of a liquid crystal display device to which the present invention is applied.

FIG. 12 is an exploded perspective view illustrating the overall configuration of the liquid crystal display device according to the present invention.

FIG. 13 is a perspective view of a notebook computer as an example of an electronic device on which the liquid crystal display device according to the present invention is mounted.

FIG. 14 is a main-portion cross-sectional view illustrating an electric field formed in a liquid crystal display device of an in-plane switching mode.

[Explanation of symbols]

DL Video signal line SD2 Drain electrode extending from video signal line CL Counter voltage signal line CT Counter electrode same as counter voltage signal line PX Pixel electrode SD1 Source electrode same as pixel electrode Cstg Storage capacitance GL Scan signal line GT Same as scan electrode Gate electrode BM Black matrix (indicated by the boundary of the opening of the pixel portion) TFT Thin film transistor SP Columnar spacer. RU particles ORI alignment film OC overcoat layer FIL color filter AOF insulating film LC liquid crystal layer GI gate insulating film PSV passivation layer (protective film) POL polarizing plate SUB substrate.

Continued on the front page F term (reference) 2H089 LA07 LA09 LA16 MA07X NA07 NA09 QA14 QA16 TA09 TA12 TA13 2H091 FA02Y FA23Z FA35Y FA42Z FB04 FC12 FD04 GA13 LA03 LA15 LA18

Claims (5)

[Claims] 1. A pair of substrates, at least one of which is transparent, at least two or more kinds of color filters having different colors for color display formed on one of the pair of substrates, and interposed between the color filters. A black matrix, an electrode group formed on the pair of substrates, a liquid crystal layer having a dielectric anisotropy between the pair of substrates, and a molecular arrangement of a liquid crystal composition forming the liquid crystal layer in a predetermined direction. A liquid crystal panel having an alignment control layer for alignment, and driving means for applying a driving voltage to the electrode group, wherein at least one of the pair of substrates has a thickness substantially equal to a desired thickness of the liquid crystal layer. A liquid crystal display device comprising a columnar spacer made of a resin in which particles of the same size are substantially uniformly dispersed. 2. The liquid crystal according to claim 1, wherein the diameter of the particles contained in the columnar spacer is smaller than the thickness of a liquid crystal layer in a central portion of a pixel formed between black matrices of the liquid crystal panel. Display device. 3. The signal wiring and the common wiring, wherein the dielectric constant or conductivity of the columnar spacer is higher than that of the liquid crystal composition forming the liquid crystal layer, and the columnar spacer is arranged at a position hidden by the black matrix. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is formed at a part between the liquid crystal display device. 4. A pair of substrates, at least one of which is transparent, at least two or more types of color filters having different colors for color display formed on one of the pair of substrates, and interposed between the color filters. A black matrix, an electrode group including a signal wiring and a common wiring formed on the other of the pair of substrates, and a dielectric anisotropy between the pair of substrates facing each other at a predetermined interval. A liquid crystal layer having the liquid crystal layer and an alignment control layer for arranging the molecular arrangement of the liquid crystal layer in a predetermined direction; A liquid crystal panel having a columnar spacer made of a resin dispersed in a liquid crystal panel; a polarizing plate laminated on each of the pair of substrates with a polarization axis intersecting; and applying a driving voltage to the electrode group. And a driving means for the liquid crystal display device, comprising: a photosensitive transfer sheet in which a photosensitive resin layer in which particles having a particle size substantially equal to the predetermined interval are mixed on a surface of a base film. The photosensitive resin layer side is attached to one of the substrates constituting the pair of substrates so as to be opposed to each other. Then, by removing the photosensitive resin layer in the non-exposed portion while leaving the exposed portion, a columnar spacer made of a resin in which particles having a size substantially equal to the thickness of the liquid crystal layer are substantially uniformly dispersed is formed. A method of manufacturing a liquid crystal display device. 5. A pair of substrates, at least one of which is transparent, at least two or more kinds of color filters having different colors for color display formed on one of the pair of substrates, and interposed between the color filters. A black matrix, an electrode group including a signal wiring and a common wiring formed on the other of the pair of substrates, and a dielectric anisotropy between the pair of substrates facing each other at a predetermined interval. A liquid crystal layer having the liquid crystal layer and an alignment control layer for arranging the molecular arrangement of the liquid crystal layer in a predetermined direction; A liquid crystal panel having a columnar spacer made of a resin dispersed in a liquid crystal panel; a polarizing plate laminated on each of the pair of substrates with a polarization axis intersecting; and applying a driving voltage to the electrode group. And a driving means for the liquid crystal display device, comprising: a heat transfer sheet comprising a heat-sealing resin layer in which particles having a particle size substantially equal to the predetermined distance are mixed on a surface of a base film. The heat-sealing resin layer side is bonded to one of the substrates constituting the pair of substrates so as to be opposed to each other, and a portion of the thermal transfer sheet corresponding to the columnar spacer forming position is selectively heated, and only the heated portion is heated. By fusing to the substrate and removing the thermal transfer sheet together with the non-heated portion, a columnar spacer made of resin in which particles having a size substantially equal to the thickness of the liquid crystal layer are substantially uniformly dispersed is formed. Manufacturing method of a liquid crystal display device.