JPH1062616A - Color filter and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the fluctuation of wiring height on a picture element by irregularities of a surface and allow a uniform and high resolution display by mutually isolating small picture elements in which one colored picture element is subsided into a plurality of pieces by a non-colored area having colorant repellency. SOLUTION: When area gradation is performed, a picture element of the same color is further subsided into small picture elements, and a non-colored area having colorant repellency is provided also between the small picture elements of the same color, so that a wiring is set only in this part. Since a non-colored area 7 is necessarily present under an Al wiring 5, and the colorant is never absorbed, this area is not colored, and swelling of a colorant receiving layer is hardly caused. Therefore, the areas for placing the wirings of a color filter have substantially the same height, and the wirings can be arranged in the same height. Even when the size of the colorant drop imparted by ink jet is not so sufficiently small as to independently dot the small picture elements of the same color, the adjacent small picture elements to be colored to the same color can be collectively colored with the same colorant drop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter, and more particularly to a mosaic color filter suitable for fine color separation of a color image sensor, a color sensor, a liquid crystal color display, and the like.

[0002]

2. Description of the Related Art In recent years, demands for higher definition, lighter weight, lower cost, and the like of input / output devices such as color imaging devices and color image display devices have been increasing. The development of various elemental technologies is progressing.

In particular, fundamental improvements have been made in color image display devices, and liquid crystal displays which are lightweight, take up little space and are suitable for portable use have rapidly spread in place of the conventional mainstream CRT. I've been.

However, in a liquid crystal display, the larger the area, the higher the price tends to be, and attempts to reduce the cost by various methods are being continued. The liquid crystal display includes an active matrix type liquid crystal having a TFT in each pixel (a so-called TFT panel), a ferroelectric liquid crystal (FLC) in which the liquid crystal itself has switching characteristics, a TN
STN liquid crystals with improved ON / OFF characteristics of liquid crystals are used.

[0005] One of the large production costs of these liquid crystal displays is a mosaic color filter which is indispensable for a color image display panel. In a liquid crystal display panel, the pixel portion has a function of modulating the amount of light transmitted therethrough. In that case, the direction of the liquid crystal molecules in the liquid crystal layer sandwiched between two polarizing plates is controlled by an electric field, the birefringence of the liquid crystal in a direction perpendicular to the polarizing plate is controlled, and light transmitted through the liquid crystal panel is controlled. Is generally modulated.

In this method, it is necessary to form a color filter in each of the pixel portions. Therefore, normally, the entire screen of the panel is divided into a number of fine picture elements, the picture pixels in the picture are further divided into three or more pixels, and red (R), green ( A fine (usually about several tens to 100 μm) optical filter that transmits light having a wavelength corresponding to G) or blue (B) and cuts light having another wavelength is formed. And in that case,
A grid-like light-shielding portion that blocks light between the fine filters (a part of the wiring is used as a light-shielding portion, or a light-shielding layer called a black matrix (BM) is formed). By covering it, you can make black more intense,
A method of improving color reproducibility by preventing color mixture between adjacent pixels is used. As described above, since the structure of the color filter is considerably complicated and fine, there are many problems to be solved in order to manufacture it at low cost.

Various methods have been proposed to reduce the cost of the color filter. Among them, as one of the promising methods, for example, an ink-jet method disclosed in Japanese Patent Application Laid-Open No. 59-75202 has been used. There is a way. That is, if the coloring material can be supplied only to the pixel portion by the ink jet method, the manufacturing process of the color filter is greatly simplified, and it can be expected that the color filter can be produced at a much lower cost than before.

However, for example, the drawing resolution of an ink jet head for a printer is not sufficient for drawing pixels of a color filter. That is, since the size of the pixel of the color filter is as small as about 100 μm or less, it is difficult to draw by the inkjet head method for a printer. Therefore, it is not easy to accurately strike different colors of ink into adjacent pixels. Further, the injected ink frequently diffuses in the colorant receiving layer or spreads and mixes on the surface (color mixing). If color mixing occurs in a color filter, color control becomes impossible.

In order to prevent such color mixing of ink between pixels, for example, a method of forming a layer for repelling ink on the surface of a region where the pixel is not desired to be colored while leaving the pixel portion as a colorant receiving region. Is disclosed in JP-A-4-123005.

However, in this method, there is a limit in preventing color mixing due to the diffusion of the ink inside the colorant receiving layer below the ink repelling layer, and the coloring material colored with the ink due to the photolithography process. There have been problems such as the necessity of the etching resistance of the receiving layer and an increase in cost due to steps such as development and washing.

In order to avoid these problems, the pixel portion is left as a colorant receiving region (colored region) into which the ink easily penetrates, and only the portion between the pixels around the pixel is cured to prevent the ink from penetrating. A method of forming a region to be suppressed (non-colored region) has been proposed (Japanese Patent Application No. 6-28).
No. 6616). By using such a method, it is possible to avoid a problem caused by insufficient resolution of the inkjet method when drawing pixels of a color filter.

[0012]

However, there are several problems that need to be solved when the above-described ink-jet method is actually used.

In the conventional color filter forming method, as described above, when drawing the pixels of the color filter by the ink jet method, if the resolution is insufficient, a non-colored area having a color repellent property is formed around the pixels. It can be supplemented by providing.

However, in some cases, it is difficult to draw even if a non-colored area is provided. that is,
For example, this occurs when halftone display is to be performed by area gradation. When realizing the area gradation method, it is necessary to further divide the pixels of the same color. In particular, in order to increase the gradation of the area gradation while keeping the resolution of the image constant, it is necessary to finely divide each color pixel without changing the overall size of each color pixel. However, it is difficult to individually draw these subdivided small pixels by the inkjet method because there is a practical limit to reducing the size of the ink droplet. It is difficult to strike the ink without overflowing the pixels smaller than the ink droplets even if a non-colored area having a color repellent property for preventing color mixture is provided around the pixels.

In order to solve this difficulty, when forming small pixels obtained by subdividing pixels of the same color, the colored pixels themselves are collectively colored without being subdivided, and a black matrix (B
M) and / or a method of subdividing pixels by wiring.
In the case of using a wiring, the wiring is arranged above the colored portion.

However, when an ink which is a colorant is applied to the colorant receiving layer (93) by an ink jet method, it depends on the material of the colorant receiving layer and the characteristics of the colorant.
As shown in (2), the region (98) to which the coloring material has been applied may be swollen due to the absorption of the coloring material and swell. The thickness of the colorant receiving layer (93) is 1
In the case of μm, there is often seen a rise of about 0.1 to 0.5 μm under practical conditions. When the wiring (95) is placed thereon, the wiring portion also rises and the fluctuation of the cell gap increases, so that a uniform liquid crystal display cannot be performed.
For example, Japanese Patent Application Laid-Open No. 2-63019 and Japanese Patent Application No. 5-1
No. 58182 discloses a method of forming a flattening layer (94) by filling the space between wirings with a resin. However, even when such a method is applied, the height of the wiring is high. Therefore, a large unevenness on the surface of the color filter on which the wiring is placed causes a large difference in height between the wirings. As a result, the wiring (95) and the transparent electrode ( 96) may occur. The flatness of the color filter surface is
It can be improved to some extent by forming a flattening layer (94) on its surface, but if it is to be completed completely, it will be 4-5 μm.
A thick flattening layer is required, which may cause new problems such as degassing and film peeling due to internal stress of the film, which is not preferable.

Further, another problem may occur when pixels larger than ink droplets are colored by the ink jet method. In order to have sufficient color reproducibility as a color filter, it is natural that the optical density of each color pixel must be sufficiently high, but it is also necessary to ensure uniform optical density within the pixel. Even if the optical density in the central part of the pixel is sufficiently high, if the density is low in the peripheral part in the pixel, the color reproducibility as a color filter will deteriorate.
In order to achieve such optical density uniformity in a pixel, it is necessary to uniformly diffuse the coloring material applied to each pixel to every corner of the pixel portion surrounded by the non-colored portion.

However, if the size of the pixel to be colored is too large with respect to the size of the coloring material (ink droplet), the coloring material applied to the pixel does not sufficiently spread within the pixel, and There is a case where a phenomenon occurs in which the color is biased in the vicinity of the place where the coloring material is injected, and the density is high only in the place, and the density is low in a place away from the place. When pixels of the same color are further subdivided into several small pixels by shielding light with a BM or wiring for area gradation, if the above-mentioned uneven distribution of the coloring material occurs, the subdivided small pixels There is a problem that a large difference occurs depending on the density of the color filter, and the color reproducibility of the color filter deteriorates.

Accordingly, an object of the present invention is to enable uniform and high-resolution display in which the variation in wiring height on a pixel due to unevenness of the surface of a color filter is avoided in subdivision of the same pixel for area gradation. It is to provide a color filter.

It is another object of the present invention to provide a color filter having uniform color density in a pixel and excellent in color reproducibility.

[0021]

Means for Solving the Problems The present inventors have conducted various studies to achieve the above object, and as a result, completed the present invention.

According to a first aspect of the present invention, a non-colored region having a color repellent property is provided on at least a part of a non-pixel region between pixels of the colorant receiving layer which has a colorant receiving layer on a transparent substrate. Is formed, in the color filter in which the colorant is applied to the remaining colorant receiving region and the pixel portion is colored, pixels of one color are subdivided into a plurality of small pixels, and these small pixels are divided in the non-colored region. The present invention relates to a color filter characterized by being separated from each other or two or more sets.

The second invention relates to the color filter according to the first invention, in which a colorant is applied to a colorant receiving region by an ink jet method and a pixel portion is colored.

The third invention relates to the color filter according to the first or second invention, wherein a wiring is formed on at least a part of the non-colored area and the wiring is not formed on the colorant receiving area.

According to a fourth aspect of the present invention, at least a coloring material receiving layer is provided on a transparent substrate, and at least a part of the non-pixel region between pixels of the coloring material receiving layer is provided with a non-colored region having a color repellent property. In a method for producing a color filter formed by light irradiation and applying a coloring material to a remaining colorant receiving region to color a pixel portion, a plurality of coloring material receiving regions separated from each other by the non-colored region are formed by non-coloring. A color filter characterized by being colored with the same coloring material droplet across a colored region, and forming a plurality of small pixels separated from each other or two or more sets in the non-colored region in a pixel of one color. It relates to a manufacturing method.

The fifth invention relates to a method of manufacturing a color filter according to the fourth invention, wherein a colorant is applied to a colorant receiving region by an ink jet method.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When performing area gradation, pixels of the same color must be further subdivided into smaller pixels. But,
If it is attempted to subdivide the pixels by shading the light between the small pixels by BM or wiring, it becomes necessary to provide wiring on the pixel portion to which the coloring material is applied, and the above-described problem caused by unevenness on the surface occurs.

Therefore, as described above, a non-colored region having a color repellent property is also provided between small pixels of the same color, and wiring is provided only in that portion. The influence can be substantially avoided.

In the case of this embodiment, as shown in FIG.
Since there is always a non-colored area (7) under the wiring (5) and there is no absorption of the colorant, this area is not colored, and the swelling of the colorant receiving layer as described above hardly occurs. For this reason, the areas where the wirings of the color filters are mounted have substantially the same height, and the wirings can also be aligned at the same height. Even if the size of the colorant droplet applied by the ink jet method is not small enough to individually separate the small pixels of the same color, adjacent small pixels to be colored in the same color are collectively colored in the same manner. It can be colored with material droplets.

At this time, as shown in FIGS. 3 (a) and 3 (b), as shown in FIG. 3 (a) and FIG. 3
2)) can be colored to form a plurality of adjacent pixels of the same color that are separated from each other by non-colored regions. on the other hand,
FIGS. 3C and 3D show an example of a case where a coloring material is supplied across a non-colored area in a conventional color filter. In the case of FIGS. 3A and 3B, the colorant droplet is also applied to the non-colored area where the colorant is not absorbed, but the colorant placed on the non-colored area is repelled without being absorbed. Since the colorant flows on the surface in the direction of the surface and is absorbed by the coloring region of the adjacent small pixel, the coloring material does not actually remain on the non-coloring region. After coloring, even if there is some residue, the coloring material receiving layer is heated and cured to fix the infused coloring material, and then the surface is washed with water or the like, and the coloring material that has not soaked into the non-colored area remains. Can be easily removed.

When coloring is performed with the same coloring material droplet across the non-colored area in this manner, the coloring material is not applied to the non-colored area which is shielded by the wiring, and the pixel through which light is transmitted. Since the coloring material can be supplied only to the portion and all the applied coloring materials are effectively disposed, the pixel density can be improved and the density in the pixel can be made uniform.

In the method for forming a color filter of the present invention,
First, a colorant receiving layer is uniformly formed on a transparent substrate on which a BM and its pixel openings are formed. Next, in order to prevent color mixture between adjacent pixels, which is likely to occur when a color material is applied, at least a part of a region shielded by the BM between pixels has a wavelength at which the color material receiving layer has sensitivity. And light-curing to impart water repellency to that portion so that the coloring material does not penetrate. At that time, if necessary, heat after exposure (P
EB: post exposure baking) may be performed. Therefore, as the resin of the colorant receiving layer used in the present invention, a negative photosensitive resin which is cured by light irradiation and the portion of which does not absorb the colorant is desirable.

In order to expose and cure the non-colored area of the colorant receiving layer corresponding to the area shielded by the BM, for example, exposure is performed from the colorant receiving layer side through a photomask corresponding to the BM pattern. By doing so, portions of the mask other than the light-shielding portions are exposed. The portion shielded by the mask remains colorable, and the portion irradiated with light becomes a non-colored region having a color repellent property. In order to form such a non-colored region, it is desirable to use a resin which is substantially colorless and transparent, and which is cured by being exposed to light. In order to impart photosensitivity to the resin, it is possible to use a method in which the resin itself has photosensitivity, or a method of adding a cationic or other photoinitiator to impart sensitivity. Since the colorant receiving layer itself is desirably colorless and transparent, the light used for exposure is preferably ultraviolet light.

The procedure of the color filter manufacturing method according to the present embodiment will be described below.

FIG. 2 is a process chart conceptually showing one example of a large flow of the procedure for manufacturing the color filter of the present embodiment. In this figure, 21 is a transparent substrate (glass substrate),
Reference numeral 22 denotes a black matrix (BM) which is a light shielding portion;
Is a colorant receiving layer (resin layer), 24 is a photomask, 25
Is an inkjet head, 26 is a protective layer, 28 is a non-colored area, and 29 is a colored area.

In the ink jet method, it is necessary to discharge ink of the same color from one ink jet nozzle. Therefore, paying attention to one nozzle, one-color ink ejection is performed in one drawing main scan in one direction. Therefore, a pixel array including the BM openings is designed in advance and arranged in the main scanning direction so that the pixel portion can be colored in the same color. A large area pixel array is formed by collecting a plurality of the pixel columns. An example is shown in FIG. A BM (22) having a pattern according to the pixel arrangement is formed on a glass substrate (21) (FIG. 2A).

Next, a material having a property of being penetrated by ink as a coloring material and being colored is applied on the BM pattern by spin coating or the like to form a coloring material receiving layer (23) (FIG. 2 ( b)).

Thereafter, in order to prevent the ink from overflowing to the adjacent pixel portion when the ink is applied, the portion where the ink is not applied between the plurality of pixel rows is arranged along the main scanning direction. Non-colored areas (2
8) (FIG. 2C). In this case, a photomask (2) that transmits ultraviolet light only in a portion corresponding to the non-colored region
Using 4), a mask corresponding to a portion (not shown) to be a colorant flow suppression region appropriately set as described above in a BM region between pixel columns and a region between pixels of the same color. A method of aligning an ultraviolet transmitting portion with the portion, irradiating the coloring material receiving layer with ultraviolet light, and photo-curing can be performed. By doing so, it is possible to form a non-colored region having a low ink wettability and a low penetration of ink between adjacent pixel columns. Note that the pixel row portion is not exposed to light by the photomask, so that photocuring does not occur and ink permeability is maintained.

Next, in the pixel portion of the colorant receiving layer in which a non-colored region is formed between adjacent pixel columns, a colorant is formed by using an ink jet head (25) with the direction of the pixel column being the main scanning direction. The ink is applied (FIG. 2D). In this figure, the main scanning direction is a direction perpendicular to the paper surface. At the time of ink ejection, one color may be ejected at a time, or ink jet nozzles for each color of red (R), green (G), and blue (B) may be arranged and simultaneously ejected in multiple colors.

After the necessary pixels have been colored, the entire surface is then light-cured or heat-cured to fix the coloring material (FIG. 2).
(E)).

A protective layer (26) is appropriately formed thereon by a method such as coating (FIG. 2 (f)).

As a display on which the color filter of the present invention can be mounted, a normal TN liquid crystal, so-called STN
There is no particular limitation, for example, an improved threshold value characteristic called an active matrix type in which a switching element such as a TFT is attached to each pixel, or a type using a ferroelectric liquid crystal. The color filter is generally installed on the inside of the two substrates to which the liquid crystal panel is attached, but may be outside the substrate, and there is no particular limitation as the color filter.

The pixel shape and pixel pattern of the present invention are as follows:
Any pixel may be used as long as the pixels are arranged in the main scanning direction. Each pixel may be any pixel, such as a rectangle, a square, a triangle, and a circle, as long as they can all be arranged evenly.

As a coloring method, an ink jet method can be used, and as a coloring material, ink for ink jet can be used. As the ink jet method used in the present invention, a method using an electrothermal converter as an energy generating element (so-called bubble jet type) or a piezo jet type using a piezoelectric element can be used. Can be set to

As the transparent substrate used in the present invention, various ones can be used according to the use of the color filter. For a liquid crystal display, a transparent glass substrate or a plastic substrate can be used. It is also possible to provide a BM at the interface with the substrate below the colorant receiving layer or to provide a BM or a wiring on the color filter according to the purpose. In such a case, if necessary, after forming the color filter, a transparent protective layer may be provided on the surface to protect the colored portion of the color filter.

The ink used in the present invention includes a dye-based ink,
It can be used with pigments, liquid inks,
It can be used with solid ink.

The coating method of the colorant-receiving layer used in the present invention may be a spin coating method, a roll coating method, a bar coating method, a spray coating method, a dip coating method, or the like. Absent.

The light shielding portion in the present invention can be formed by forming a BM. As a BM, a metal film is formed on a substrate by a film forming method such as sputtering or vacuum evaporation, and an opening or the like is patterned by a photolithographic method, or a black resin is applied and then patterned by a photolithographic method, or a BM is formed by a printing method. A formed one can be used. Further, the BM may be formed on a protective layer such as a resin film formed on the color filter after forming the color filter. Further, wiring used for driving the liquid crystal of the pixel can be used.

The colorant-receiving layer in the present invention is formed by applying a material which can be colored by an ink-jet method or the like and is capable of forming a non-colored area by spin coating or another method after the formation of the colorant-receiving layer. be able to. Materials having such properties include, for example, (i) a homopolymer of a monomer having a structural unit represented by the following structural formula (I) and / or a copolymer with another vinyl monomer. And (i
i) It can be realized by a resin containing at least a compound selected from a halogenated triazine compound, a diphenyliodonium salt derivative and a triphenylsulfonium salt derivative.

[0050]

Embedded image In the formula, R1 is a hydrogen atom or a methyl group, and R2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

Examples of the monomer comprising the structural unit represented by the above formula (I) include N-methylolacrylamide,
N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, N-isopropoxymethyl acrylamide, N-methylol methacrylamide, N-methoxymethyl methacrylamide, N-ethoxymethyl methacrylamide, and the like, but are not limited thereto. Absent. These monomers are polymerized alone or copolymerized with other vinyl monomers. Other vinyl monomers include acrylic acid, methacrylic acid, acrylates such as methyl acrylate / ethyl acrylate, methacrylates such as methyl methacrylate / ethyl methacrylate, hydroxymethyl methacrylate / hydroxyethyl acrylate, etc. Vinyl monomers having a hydroxyl group of, styrene, α-methylstyrene, acrylamide, methacrylamide, acrylonitrile, acrylamine, vinylamine, vinyl acetate, vinyl propionate, and the like, but are not limited thereto. .

(Ii) with respect to the resin of (i)
About 10% by weight is required. Examples of the halogenated triazine compound (ii) include compounds represented by the following formula (II).

[0053]

Embedded image In the formula, Y represents CZ ₃ , phenyl, halogenated phenyl and other substituents, and Z represents a halogen atom.

Specifically, for example, 6-bis (trichloromethyl) -S-triazine, 2-styryl-4,6-
Bistrichloromethyl-S-triazine and other compounds include, but are not limited to.

The diphenyliodonium salt derivative which is another compound (ii) includes a compound represented by the following formula (III).

[0056]

Embedded image In the formula, R ₄ and R ₅ are a hydrogen atom, an alkoxy group having 1 to 5 carbon atoms or a t-butyl group, and X ⁻ is BF ₄ ⁻ , PF ₆ ⁻ ,
SbF ₆ ^- or CF ₃ SO ₃ ^- is.

Specific examples include, but are not limited to, compounds such as diphenyliodonium hexafluoroantimonate and diphenyliodonium tetrafluoroborate.

As the other compound (ii), a triphenylsulfonium salt derivative, a compound represented by the following formula (IV) can be mentioned.

[0059]

Embedded image In the formula, R ₆ is a hydrogen atom, an alkoxy group having 1 to 5 carbon atoms or an alkyl group having 1 to 5 carbon atoms, —SPh or a fluorine atom, and X ⁻ is the same as in the above formula (III).

Specific examples include, but are not limited to, compounds such as triphenylsulfonium hexafluoroantimonate and triphenylsulfonium hexafluoroborate.

The compound of (ii) functions as a photoinitiator when the monomer of (i) is subjected to a photo-polymerization treatment for preventing color mixture.

The colorant receiving layer in which these materials are laminated on a substrate absorbs a colorant such as an ink for ink jet and is colored. The portions having ink repellency to prevent color mixing are cured by ultraviolet light before coloring. In the part irradiated with ultraviolet rays, the monomer polymerizes and the dye molecules of the ink become difficult to move,
In addition, the OH group is reduced, and the property of repelling ink appears. As a result, the area is hardly permeated by ink and hardly wetted. This makes it difficult for the ink to diffuse and move to this area, and an effect of preventing color mixing can be obtained.

[0063]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.

Example 1 In this example, a mosaic color filter for a liquid crystal display device was formed on a glass substrate (see FIGS. 4 and 8).

First, a Cr film is formed to a thickness of 700 ° on a glass substrate by a sputtering method, and a pixel having an opening in a pixel portion having a shape as shown in FIG. 4 corresponding to an exposure pattern of a non-colored region is formed by a photolithographic method. A light shielding BM was formed. The size of the pixel (45) for one color is 100 × 300 μ
The pixel was further divided into four by m to form a small pixel (46). Such pixel division makes it possible to perform multi-tone area gradation of each color. The pixel pitch of the same color is 300 μm.
The distance between adjacent pixels of different colors was 100 μm.

Next, the structural formula (I) (R ₁ = H, R ₂ =
H) A resin obtained by adding triphenylhexafluoroantimonate to an acrylic resin having 4% by weight based on the resin is dissolved in an ethyl cellosolve solvent, and the solution is spin-coated on a BM to a thickness of about 1 μm. It was applied and dried at 50 ° C. for about 30 minutes.

After drying, the colorant receiving layer is exposed to ultraviolet light having a wavelength of 290 nm or less through a photomask having a pixel division pattern shown in FIG. 4, and further subjected to PEB heating (post exposure bake) at 110 ° C. for 90 seconds. Then, a non-colored area (41) having a color repellent property was formed around the small pixels in accordance with the pixel division.

Next, the colored region (4
In 2), three kinds of inks of red (R), green (G), and blue (B), which are coloring materials, were ejected according to the initial design by the ink jet method in the manner shown in FIG. The ink was absorbed by the pixel portion, but was repelled in the non-colored area formed around the pixel portion, did not leak to adjacent pixels, and did not mix. In addition, with respect to the above procedure, when it is intended to accurately apply the ink as the coloring material on the pixel,
Since it is not possible to strike at equal intervals, complicated control is required according to the position of the pixel.

The distribution of the optical density within the small pixel was ± 5% or less, which was a level that was not problematic in practical use. In addition, since the coloring material was not absorbed in the non-colored area between the divided small pixels, no swelling of the coloring material receiving layer occurred in this portion. Although a slight swell occurred in the colored region of the pixel portion, there was no problem.

After the ink ejection, the entire substrate was heated at 50 ° C. for 30 minutes.
After drying for a minute, the pixel portion which was not irradiated with light at 200 ° C. was heated and cured for 1 hour. As a result, the entire colorant receiving layer was cured.

After washing with water and drying, an acrylic resin-based protective layer was applied to a thickness of about 1 μm to complete a color filter.

The colored portion of the pixel had a swell of about 0.1 to 0.2 μm, but the non-colored portion had a uniform thickness.

The non-colored area on the color filter thus formed is formed by sputtering and photolithography.
When an Al wiring (85) was formed as shown in FIG.
The height of the wiring was equal everywhere.

After the formation of the wiring, the colored pixel portion between the wirings was buried with a resin in the same manner as in JP-A-2-63019 to planarize (form the flattening layer (84)) and obtain a surface. The unevenness was extremely flat at about ± 15 nm.

After curing, a transparent electrode (86) was formed, and an orientation control film was further formed to complete a segment substrate.
The common substrate was not formed with a color filter, but was formed in the same manner, and was laminated to form a cell. The ferroelectric liquid crystal was injected and a drive circuit and other components were mounted to complete a liquid crystal display device. When this was driven, good halftone reproducibility was exhibited and a very good image was obtained.

COMPARATIVE EXAMPLE 1 In order to compare the effect of the present invention with the conventional method, an example will be described in which subdivision of pixels of the same color for area gradation is performed only by light shielding by BM and wiring.

A color filter was formed in substantially the same manner as in Example 1. However, the shape of the non-colored region was the configuration shown in FIG. 5 in which the same color pixel was not divided. FIG. 3 shows an ink-jet method using such a non-colored region shape.
The pixels were colored in the manner shown in (c).

As a result, color mixing with another adjacent color pixel did not occur, and the pixel could be colored in an accurate shape. However, the density distribution in the pixel became large, and the optical density particularly at the corner of the pixel became low.
The difference in optical density between the highest density portion and the lowest density portion is 10 to 15%, and the area of the low density region is also 1%.
It was large at about 0 to 20%.

When a protective layer was provided on the central portion of the pixel that was colored and raised, and a wiring was formed thereon, the difference in height (bump) from the wiring on the non-colored area was 0.2.
It was about μm. Therefore, a difference occurs in the height of the wiring, and when a flattening layer is formed by filling the resin between the wirings, the resin remains on the wiring, and the wiring and the transparent electrode formed on the flattening layer and the wiring are not covered by the resin. Contact deteriorated, and a predetermined voltage could not be applied to the pixel electrode. For this reason, the image when formed as a liquid crystal display device was defective.

Example 2 A color filter was formed in substantially the same manner as in Example 1. However, in order to simplify the control of the application of the coloring material by the ink jet method, coloring was performed by scanning in the longitudinal direction of the pixel in the manner shown in FIG. 3B using the non-colored area pattern shown in FIG.

As a result, the coloring material was applied to the portion of the coloring material receiving layer which was shielded by the BM between the BM openings adjacent to each other in the scanning direction and was colored, but no practical problem occurred. There was an effect that coloring control by the ink jet method was simplified.

As shown in FIG. 3B, adjacent colored regions (62) of the same color are provided with a coloring material across the non-colored region (61) therebetween. The colorant flowed over the surface without being absorbed there, and was absorbed by the colored regions (62) adjacent on both sides thereof, and as a result, almost no colorant remained in the non-colored regions.

Further, since a non-colored area is formed in the longitudinal direction of the portion shielded by the BM, there is no absorption of the colorant there, and the colorant is not absorbed by the non-colored area on the BM opening. Since the pixel was effectively used for coloring, the optical density of the pixel was sufficiently high, and the density distribution in the pixel became very uniform.

After the coloring was completed, the coloring material receiving layer was heated and cured to fix the coloring material, and further washed with water to wash away a little coloring material remaining in the non-colored area. The coloring material that could be removed and absorbed in the colored portions of the pixels was not removed at all by washing with water.

After drying, a protective layer was applied to a thickness of about 1 μm and thermally cured. The thickness of the non-colored area on which the wiring was placed and the color filter were uniform, and the unevenness was 30 nm or less.

Next, an Al wiring was formed in this portion to a thickness of 500 nm by sputtering and photolithography. The height of the surface was uniform.

After forming the wiring, a resin was buried between the wirings to form a flattening layer, and a transparent electrode was formed on the flattening layer and the Al wiring. The electrical contact between the transparent electrode and the Al wiring was extremely good.

The color filter thus prepared, A
A liquid crystal panel was manufactured using a substrate provided with a wiring and a transparent electrode and a separately prepared substrate with a counter electrode. With this liquid crystal panel, an extremely good image was obtained.

Comparative Example 2 A color filter was manufactured in substantially the same manner as in Example 2. However, the non-colored region was formed by using the pattern shown in FIG. 7 instead of FIG. 6, and coloring was performed by the inkjet method in the manner shown in FIG. 3D.

As a result, the portion on which the wiring running in the same color pixel was mounted was raised as shown in FIG. After heating and curing for fixing the coloring material, washing was performed, but the surface of the coloring material receiving layer remained raised without any change in the unevenness of the wiring portion. The image of the liquid crystal panel using the color filter produced as described above was defective.

[0091]

According to the present invention as described above,
When the same color pixel is further subdivided into small pixels for area gradation, etc., a color filter with a flat surface and a uniform optical density distribution within the pixel can be obtained. A liquid crystal display device formed and manufactured can obtain a uniform image with high resolution and excellent color reproducibility.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a color filter of the present invention.

FIG. 2 is a manufacturing process diagram of the color filter of the present invention.

FIG. 3 is an explanatory diagram of a method of applying a coloring material in a coloring step of a pixel portion in the present invention and a conventional color filter manufacturing process.

FIG. 4 is a diagram showing an example of a non-colored area pattern of the color filter of the present invention.

FIG. 5 is a diagram showing an example of a non-colored area pattern of a conventional color filter.

FIG. 6 is a diagram showing an example of a non-colored area pattern of the color filter of the present invention.

FIG. 7 is a diagram illustrating an example of a non-colored area pattern of a conventional color filter.

FIG. 8 is a sectional view of the color filter of the present invention.

FIG. 9 is a sectional view of a conventional color filter.

[Explanation of symbols]

1, 21, 81, 91 Transparent substrate 2, 22, 43, 53, 63, 73, 82, 92 Black matrix (BM) 3, 23, 83, 93 Colorant receiving layer 4, 84, 94 Flattening layer 5, 85, 95 Al wiring 6, 86, 96 Transparent electrode 7, 28, 31, 41, 51, 61, 71, 87, 97
Non-colored area 8, 29, 32, 42, 52, 62, 72, 88, 98
Coloring region (coloring material receiving region) 24 Photomask 25 Inkjet head 26, 89 Protective layer 33 Coloring material droplet 34, 44, 54, 64, 74 Black matrix opening (BM opening) 45, 55, 65, 75 One color Minute pixel 46 Small pixel

Claims (5)

[Claims] 1. A non-colored area having a color repellent property is formed on at least a part of a non-pixel area between pixels of the colorant-receiving layer, the non-colored area having a color repellent material formed on a transparent substrate.
In the color filter in which the colorant is applied to the remaining colorant receiving region and the pixel portion is colored, pixels of one color are subdivided into a plurality of small pixels, and these small pixels are mutually or two sets in the non-colored region. A color filter characterized by being separated as described above. 2. The color filter according to claim 1, wherein a colorant is applied to the colorant receiving region by an ink jet method, and the pixel portion is colored. 3. The color filter according to claim 1, wherein a wiring is formed on at least a part of the non-colored area, and is not formed on the colorant receiving area. 4. A coloring material receiving layer is provided at least on a transparent substrate, and a non-coloring region having a color repellent property is formed by light irradiation on at least a part of a non-pixel region between pixels of the coloring material receiving layer. Then, in the method of manufacturing a color filter for coloring the pixel portion by applying a coloring material to the remaining coloring material receiving region, a plurality of coloring material receiving regions separated from each other by the non-coloring region, straddling the non-coloring region. A method for producing a color filter, characterized in that a plurality of small pixels separated from each other or two or more pairs in the non-colored area are formed in a pixel of one color by coloring with the same colorant droplet. 5. The method for producing a color filter according to claim 4, wherein the colorant is applied to the colorant receiving region by an ink jet method.