JPH0980223A - Color filter, manufacturing method thereof, and liquid crystal element - Google Patents

Abstract

(57) [Summary] [Object] To provide a high-precision color filter having high color reproducibility and high surface flatness without color mixture, and a method for producing the same. In a color filter having a plurality of fine pixel portions of different colors on the same transparent substrate, a plurality of pixel portions 22 and a light shielding film 22 having a plurality of openings 31a to 31c formed at positions where the pixel portions are provided. Of different colors and the same number of plural colored layers 23 to 25, each of the colored layers being formed of a visible light transparent material and having the same color in the portion corresponding to the opening of the light shielding film. The colored layers 26 to 28 are colored, and the colored layers 23 to 25 are laminated so that the colored portions 26 to 27 colored with different colors of the colored layers do not overlap each other. A color filter in which each of the colored portions 26 to 28 forms a pixel portion 30 in which a plurality of different colors are arranged through the openings 31a to 31c of the light shielding film, and a manufacturing method thereof.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a color filter,
The manufacturing method and a liquid crystal device, particularly a color filter suitable for fine color separation of a color imaging device, a color sensor, a liquid crystal color display, and the like,
The present invention relates to a manufacturing method thereof and a liquid crystal element using the same.

[0002]

2. Description of the Related Art In recent years, there have been increasing demands for high-definition, light-weight, and low-cost input / output elements such as color image pickup devices and color image display devices. Various elemental technologies are being developed.
In particular, the image display apparatus is undergoing a radical change in method, and a liquid crystal display which is lightweight and space-saving and suitable for carrying is rapidly becoming popular in place of the conventional mainstream CTR.

Although liquid crystal displays have become very easy to use, it cannot be said that the prices for large-area displays are sufficiently low, and various methods are being used to reduce the cost. . As an example of such a method, there is an improvement from an active matrix type liquid crystal having a TFT in each pixel to a ferroelectric liquid crystal having a switching characteristic in the liquid crystal itself, and a simple matrix type S
There are improvements in TN liquid crystal.

Another of the liquid crystal displays, which makes up a large proportion of the cost, is a color filter which is indispensable for displaying a color image. In general, this color filter divides the entire screen into a large number of fine pixels, and further divides one pixel into three, into which red,
A fine (about 100 μ or less) optical filter element that transmits green and blue is formed. By covering the space between each fine filter element with an opaque grid-like mask (black matrix), the method of improving the color reproducibility by making the black blacker and preventing the color mixture with the adjacent color is popular. are doing. As described above, since the structure of the color filter is considerably complicated and fine, there has been a big problem in manufacturing the color filter with high accuracy and at low cost.

Conventionally, as a method for producing a color filter, a mordant layer made of a hydrophilic polymer such as gelatin, casein, mulberry or polyvinyl alcohol is provided on a substrate, and the mordant layer is dyed with a dye to form a colored layer. A so-called dyeing method is known in which the forming process is repeated with three colors of red, green and blue. With this method, many dyes can be used, and it is relatively easy to respond to the spectral characteristics required as a filter, but in the dyeing process of the mordant layer, the mordant layer is immersed in a dyeing bath in which the dye is dissolved. It employs a wet process that is difficult to control.It also has complicated steps such as providing an intermediate layer for dye protection for each color, and using a photolithography process for each color for the mordant layer and patterning for dye protection. It has the disadvantage of long time and poor yield. Further, there is a problem in the durability of the color filter because the dye used in the above dyeing has low heat resistance and light resistance.

On the other hand, JP-A-55-134807,
JP-A-60-129707, JP-A-60-237
In the so-called pigment dispersion method, which uses a colored resin film obtained by mixing a colorant such as a pigment with a photosensitive resin as disclosed in JP 441, JP-A-61-105505, etc. Since it contains a coloring material such as a pigment from the beginning, the step of dyeing after the formation of the color filter layer is unnecessary, and therefore, the formation of an intermediate layer for dye protection is also unnecessary. Therefore, the steps are simplified by the above dyeing method. However, it is necessary to use the photolithography process for each of the three colors for patterning the colored layer, the process is complicated, and the use efficiency of the expensive photolithography resist material is low, and the material is wasted. There was a drawback.

Various methods have been proposed for forming a color filter by a simpler method, instead of such a complicated forming method. For example, the printing method is intended to form fine pixels by a high-precision printing technique such as flat plate offset printing or screen printing. The printing method is seemingly simple and promising for cost reduction, but in reality, the conventional printing method has low accuracy for high-density color displays, and it is difficult to form a color filter with high pixel density. Is.

Further, in the electrodeposition method to which electrodeposition coating is applied, a transparent electrode is required only for electrodeposition of the coloring material, and since the electrode is used, the shape of the filter pixel is restricted, and the cost is reduced and the resolution is high. The problem remains for the conversion.

Therefore, it cannot be said that a method of manufacturing a color filter with high accuracy and low cost has been established yet, and a method different from the conventional method is required.

[0010]

As described above,
Conventionally used dyeing methods, pigment dispersion methods, printing methods, electrodeposition methods, etc. all have problems as a method of manufacturing a color filter with high accuracy and a sufficiently flat surface for a color display and at a low cost. there were.

For example, when using a ferroelectric liquid crystal,
In many cases, the liquid crystal material itself has a considerably large refractive index anisotropy, and therefore it may be necessary to reduce the thickness of the liquid crystal cell. Is an important issue.

Further, from the viewpoint of cost, it is difficult to significantly reduce the cost by the dyeing method and the pigment dispersion method, and the printing method can be expected to greatly reduce the cost. However,
In the conventional printing method, the mechanical strength is still weak at the time of application, the formed pattern is easily broken because the filter layer has to be formed by the ink itself, and the surface flatness is insufficient. As a method of flattening the surface of a color filter by a printing method, polishing (see JP-A-61-3123) or use of a spread roll (JP-A-2-2975).
No. 02) is proposed, but the problem remains that the accuracy of the pixel pattern drops during flattening.

Another method is disclosed in JP-A-59-752.
A method using an inkjet method as disclosed in Japanese Patent Publication No. 05 etc. has been proposed. However, when the inkjet method is simply applied, the drawing resolution may not be sufficiently high for drawing the pixels of the color filter. Therefore, it is not easy to accurately eject inks of different colors in adjacent pixels. Also, the ink may diffuse in the ink receiving layer and mix with the adjacent pixel. In order to prevent such ink mixture (color mixture) between pixels, for example, there is a method of forming an ink repellent layer on the surface of a colored layer in a light-shielding portion between pixels in Japanese Patent Laid-Open No. 4-123005. Etc. are disclosed.
However, in this method, when it is not possible to sufficiently prevent the ink from diffusing in the colored layer and being mixed with each other, it is necessary that the colored layer colored with the ink has high etching resistance because a photolithography process is included. In this case, costs may increase due to steps such as development and cleaning, and various means for solving the problems have been studied and developed.

Therefore, an object of the present invention is to improve the precision of pixel patterning, which is a problem thereof, while taking advantage of a printing method which is a low-cost process having a simple process and high material utilization efficiency. It is an object to provide a highly accurate color filter that has no color mixture, high color reproducibility, and high surface flatness at low cost.

It is another object of the present invention to provide a liquid crystal device which can obtain a good image by using the above-mentioned highly accurate color filter.

[0016]

That is, according to the present invention, in a color filter having a plurality of fine pixel portions of different colors on the same transparent substrate, a plurality of openings are formed at positions where the pixel portions are provided. A film and a plurality of colored layers of the same number as the number of different colors of the pixel portion, each of the colored layers being formed of a visible light transparent material and in a portion corresponding to the opening of the light shielding film. The colored layers are colored in the same color, and the colored layers are laminated so that the colored parts colored in different colors of the colored layer do not overlap with each other. Is a color filter characterized in that a pixel portion in which a plurality of different colors are arranged is formed through the opening of the light shielding film.

The present invention also provides a method for manufacturing a color filter having a plurality of fine pixel portions of different colors on the same transparent substrate, 1) a first colored layer made of a visible light transparent material on the transparent substrate. And 2) a step of curing the visible light transparent material in a region other than the region of the colored layer of the first color to form a coloring prevention region, and 3) the pixel of the first color. A step of supplying a coloring material of a first color to the region to be printed to form a colored portion by coloring, 4) a step of curing the colored first colored layer, and 5) a first coloring A step of laminating a colored layer made of a visible light transparent material different from the first colored layer on the layer, and 6) repeating the steps 2) to 5) of coloring a color different from the first color. This is done by stacking the same number of colored layers as the number of different colors in the pixel section and coloring each colored layer. There is a method for manufacturing a color filter, which comprises forming without each other overlap.

Furthermore, the present invention is a liquid crystal element in which a liquid crystal is arranged between a pair of substrates on which transparent electrodes are formed, wherein at least one substrate is a substrate having the above color filter. It is an element.

The present invention will be described in detail below. The color filter of the present invention is a color filter having a plurality of fine pixel portions of a plurality of different colors of n colors (n is an integer of 2 or more) on the same transparent substrate: 1) A large number of openings at positions where the pixel portions are provided. And a plurality of colored layers having the same number as the plurality of different colors of the pixel section, and 2) the colored layers are formed of a visible light transparent material, and the visible light transparent material. A first colored layer having a colored portion colored with the first color in the vicinity of the opening where the pixel of the first color of the light shielding film is formed, and 3) the pixel of the first color of the light shielding film. A second colored layer having a colored portion colored with a second color in the vicinity of an opening where a pixel of a second color different from the above is formed; The vicinity of the opening where the pixel of the third color different from the pixel of the second color is formed has the colored portion colored with the third color. A third colored layer; and 5) an nth colored layer having a colored portion colored with the nth color in the vicinity of the opening where the pixel of the nth color is formed by repeating the above 3) in the same manner, Each of the colored layers are laminated so that the colored portions colored with different colors of the colored layer do not overlap each other, and each of the colored portions has a plurality of openings through the opening of the light shielding film. It is characterized in that a pixel portion in which different colors are arranged is formed.

The method of manufacturing a color filter as described above is the same as the method of manufacturing a color filter having a plurality of n-color fine pixel portions of different colors on the same transparent substrate. 1) A light-shielding film is provided on the transparent substrate. Forming, and forming a large number of openings at positions where the pixel portion of the light shielding film is provided, 2) providing a first colored layer made of a visible light transparent material on the light shielding film of the transparent substrate, 3) A step of forming a coloring prevention area on the visible light transparent material in an area other than an area to be a pixel of the first color of the first colored layer by light pattern exposure, or light curing by light pattern exposure and heating, 4) above A step of supplying a coloring material of the first color by printing to form a colored portion in the color mixture prevention area pixel portion, which is an area to be a pixel of the first color, 5) the colored first coloring Curing the layer by heat or light 6) A step of laminating and providing a colored layer made of a visible light transparent material different from the first colored layer on the first colored layer, 7) Coloring a color different from the first color described above. The steps 3) to 6) are repeated to form the same number of coloring layers of the nth color as the number of different colors in the pixel portion, and the coloring portions of the respective coloring layers do not overlap with each other. It is characterized by doing.

Further, the liquid crystal element of the present invention is characterized in that it uses a color filter formed by laminating a plurality of the above-mentioned colored layers of the nth color, and has a high strength between a pair of substrates on which transparent electrodes are formed. A liquid crystal element in which a dielectric liquid crystal is disposed and the above-mentioned color filter is provided between at least one transparent electrode and the substrate.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of the color filter of the present invention. In FIG. 1, the color filter of the present invention is a color filter having fine pixel portions of three colors, for example, different colors of red, blue and green. A light-shielding film 22 is formed on a transparent substrate 21, and a large number of openings 3 are formed in the light-shielding film 22 at positions where pixel portions 30 are provided.
1 indicates a black matrix, and on the light-shielding film 22, three colored layers of the same number as the three different colors of the pixel portion are laminated.

First, the first colored layer 2 is formed on the light shielding film 22.
3 is provided. The first colored layer 23 is formed of a visible light transparent material, and the first colored layer 23 is colored with the first color in the vicinity of the opening 31a where the pixel of the first color of the light shielding film 22 is formed. Thus, the colored portion 26 of the first color is formed.

A second colored layer 24 is provided on the first colored layer 23. The second colored layer 24 is also formed of a visible light transparent material, and the second color is formed in the vicinity of the opening 31b in which the pixel of the second color different from the pixel of the first color of the light shielding film 22 is formed. A colored portion 27 that is colored is formed.

Further, a third layer is formed on the second colored layer 24.
The colored layer 25 is provided. The third colored layer 25 is similarly formed of a visible light transparent material, and the vicinity of the opening 31c where the pixel of the third color different from the pixels of the first and second colors of the light shielding film 22 is formed is the third. The colored portion 28 colored with the color is formed.

A protective layer 29 is provided on the third colored layer 25, and each of the first to third colored layers 23, 24 and 25 is colored with a different color from the colored layer. 26,
27 and 28 are laminated so as not to overlap each other, and the colored portions 26, 27, and 28 are formed in the openings 31 of the light-shielding film 22.
A pixel portion 30 in which three colors are arranged is formed through a to 31c to form a color filter.

Next, a method for manufacturing the color filter of the present invention will be described. 2 to 4 are process diagrams showing an example of the method for manufacturing a color filter of the present invention. FIG. 2 is a process diagram showing a pre-process of the method for manufacturing a color filter of the present invention, FIG.
FIG. 4 is a process diagram showing an intermediate step of the method for producing a color filter of the present invention, and FIG. 4 is a process diagram showing a subsequent step of the method for producing a color filter of the present invention.

First, in FIG. 2A, the light shielding film 2 is provided on the transparent substrate 1. A large number of openings 31 are formed in the light-shielding film 2 at the positions where the pixel portions are provided to form a black matrix. 2 (2), a colored layer is applied. In this case, the light shielding film 2 may be applied before the colored layer is applied, or the light shielding film 2 may be applied after forming the colored layer. It may be laminated on top. If necessary, a light shielding film may be formed between the colored layers of different colors.

Next, in FIG. 2B, a colored layer 3 of a first color made of a visible light transparent material transparent to visible light is applied on the transparent substrate 1. As the method for applying the colored layer, various methods described later can be used in addition to the spin coating method. A material that absorbs the coloring material is used for the coloring layer.

Next, in FIG. 2 (3), a portion other than the pixel portion 7 is photocured by light pattern exposure 4 to be crosslinked,
Except for the pixel portion, the coloring material is prevented from being absorbed in the next coloring step. At this time, the exposure pattern may be left uncured without exposing all the pixel parts of different colors, or exposing all except the pixel part of the color to be colored in the next coloring step. The pattern may be used to cure all but the pixel portion colored in the first color. After exposure, it may be heated with an oven or a hot plate to accelerate curing. Utilizing the property that the colorant is not absorbed in the cross-linking cured portion 8 is an important point for realizing the present invention. This exposure can be realized with high resolution by using a photolithography exposure device and a photomask.

Next, in FIG. 2 (4), a coloring material is supplied to the pixel portion 7 by a printing method so that the uncured visible light transparent material of the coloring layer 3 of the first color absorbs the coloring material. Reference numeral 5 in FIG. 2 (4) shows a blanket cylinder for printing the coloring material of the first color on the pixel portion when the offset printing is used. Printing plate for forming pixels of the first color (not shown in the figure)
Then, the coloring material is transferred onto the blanket cylinder 5 to color the uncured visible light transparent material and then cured to complete the coloring of the colored portion 6 of the first color.

Next, in FIG. 3 (5), after the coloring of the colored layer of the first color in FIG. 2 (4) is completed, the uncured pixel portion 7a of the colored layer of the first color is exposed to light or light. It is cured by heat 9. After the curing, the surface of the colored layer may be washed to remove the coloring material not absorbed by the colored layer.

Next, in FIG. 3 (6), on the colored layer 3 of the first color which has been colored as shown in FIG. 3 (5), the pixel of the second color different from the first color is colored. The colored layer 10 of the second color is applied in the same manner as the coating of the colored layer 3 of the first color.

Next, in FIG. 3 (7), in the same manner as in the case of coloring the first color, the portions other than the pixel portion 7 are photo-cured by light pattern exposure 4 to be crosslinked, and the portions other than the pixel portion 7 are Prevent the colorant from being absorbed in the next coloring step. At this time, the exposure pattern may be left uncured without exposing all the pixel parts of different colors, or exposing all except the pixel part of the color to be colored in the next coloring step. The pattern may be used to cure all but the pixel portion colored in the second color. Similar to the case of coloring the first color, after the exposure, heating may be performed with an oven or a hot plate to accelerate the curing.

Next, in FIG. 3 (8), the coloring material is supplied to the pixel portion 7 b of the second color by the printing method similarly to the printing of the first color, and the coloring layer 12 of the second color is not formed. Absorb into a cured visible light transparent material. Reference numeral 11 in FIG. 3 shows a blanket cylinder for printing the second color coloring material on the pixels when offset printing is used. The coloring material is transferred onto the blanket cylinder 11 for coloring with a printing plate (not shown in the figure) for the pixels of the second color and then cured to color the coloring portion 12 of the second color. Complete.

Next, in FIG. 4 (9), when the coloring of the second colored layer shown in FIG. 3 (8) is completed, the uncured pixel portion 7 b of the second colored layer 10 is exposed to light or light. It is cured by heat 9. After the curing, the surface of the colored layer may be washed to remove the coloring material not absorbed by the colored layer.

Next, FIGS. 4 (10), (11) and (12)
In the above, the same procedure as described above is performed for coloring the third color, the third color coloring layer 13 is applied on the second color coloring layer 10, and only the pixel portion is left to emit light. The pattern is exposed to light 4 and cured, and the colorant is applied to the blanket cylinder 1 with a printing plate (not shown in the figure) for pixels of the third color.
4 and transferred onto 4 to be colored, and then cured to give a third colored portion 1
Complete the coloring of 5.

Next, in FIG. 4 (13), the uncured pixel portion 7 c of the colored layer 13 of the third color is cured by light or heat 9. After the curing, the surface of the colored layer may be washed to remove the coloring material not absorbed by the colored layer.

As described above, the colored layer 16 of the first color in which only the pixels of the first color are colored, the colored layer 17 of the second color in which only the pixels of the second color are colored, and the colored layer 17 in the third color are colored. A color filter in which a colored layer 18 of a third color in which only pixels are colored is laminated can be formed. The color filter is a color filter having fine pixel portions of three colors of red (R), blue (B) and green (G).

If necessary, a translucent protective layer may be applied onto the laminated colored layers to protect the colored layers or improve the surface flatness.

As a printing apparatus which can be used in the present invention, a flat plate offset printing machine, an intaglio gravure printing machine, a screen printing machine, a letterpress printing machine and the like which have been conventionally proposed for forming a color filter can be used. By such a method, the coloring material can be supplied at low cost.

The method for producing a color filter of the present invention comprises
The difference from the printing method that is a conventional color filter manufacturing method is that, first of all, the coloring material such as ink does not form the color filter layer by itself, but the coloring material is absorbed in the coloring layer, The color filter layer is not the coloring material itself but the coloring layer. This allows
Problems such as deformation of the ink layer due to pressure in the printing process and formation of irregularities due to overlapping of ink, which deteriorate patterning accuracy, are avoided.

Secondly, only the pixel portion of the coloring layer absorbs the coloring material, and the other portions do not absorb the coloring material, so that the forming accuracy of the filter pixel is substantially determined by the above-mentioned exposure accuracy. Therefore, the decrease in precision conventionally associated with ink supply by printing is avoided thereby. For example, when offset printing is performed on a colored layer using a slightly deformable rubber blanket cylinder, the surface of the blanket cylinder is slightly deformed by the pressure, and the supply position of the coloring material (corresponding to ink) is on the substrate. Even if it is slightly deviated from the pixel portion, the liquid colorant is not absorbed in the portion deviated from the pixel portion but is drawn into the pixel portion and absorbed, and the positional deviation of the supply is automatically corrected. There is a similar correction effect for the positional deviation which is a problem in screen printing. Accurate alignment between the printing plate and the pixel portion on the substrate is necessary, but its accuracy may be approximately the same as the accuracy required by a normal printing method because of the absorption region of the coloring material. A slight misalignment is automatically corrected in the same manner as a misalignment due to the deformation of the printing plate.

In offset printing, oily ink is usually placed on the lipophilic surface of a printing plate, and water is supplied to the hydrophilic surface to suppress ink adhesion. However, in the present invention, when a hydrophilic coloring layer is used, on the contrary, a hydrophilic coloring material is placed on the hydrophilic surface of the printing plate to prevent the adhesion of the coloring material by utilizing the water repellency of the lipophilic surface. Can be suppressed.
The printing plate of the present invention has a negative / positive relationship with respect to the case of using an oil-based ink. Creation of a printing plate suitable for each of these printing methods can be devised according to each printing method. By forming the photo-cured region, higher accuracy can be obtained as compared with the method of forming a color filter by a normal printing method, and therefore, a wider variety of printing methods than conventional can be applied. Further, by applying the printing method, the same color can be simultaneously drawn for a plurality of pixels.

As described above, in the present invention, by providing different colored layers for each color, the uncured pixel portion which should not be colored during printing absorbs the colorant which should not be colored. It is possible to avoid the risk of causing it, and it is possible to reliably prevent pixels of a specific color from overlapping with another color. Further, when the absorption characteristics of the coloring layer differ depending on the color and type of the coloring material, there is an advantage that the absorption characteristics can be optimized for each color by using different absorption layer materials for each color.

In the present invention, it is necessary to accurately expose and photo-cure the portions other than the pixel portion, but unlike photolithography, steps such as development and etching are not necessary. For this reason, a developing solution and a cleaning solution are not required, and not only the direct material can be remarkably saved, but also defective products generated in this process are much smaller than those in photolithography.

As the transparent substrate used in the present invention, any transparent substrate conventionally used for color filters can be used. For example, soda lime glass, non-alkali glass, glass such as quartz glass, polycarbonate resin, acrylic resin and other plastic substrates, and thin crystals of sapphire can also be used. The thickness is not particularly limited in principle, but is practically about 0.1 to 3.0 mm. If necessary, a light-shielding film between pixels, that is, a so-called black matrix may be formed on the transparent substrate.

As the coating device for the colored layer, various types of devices other than the spin coater can be used. Various roll coaters, blade coaters, air knife coaters,
A rod bar coater or the like can be used. After coating, a solid colored layer is formed by heat drying using an oven or a hot plate or natural drying. The thickness of the colored layer is 0.1-5
It is about 0 μm, more preferably about 0.5 to 5 μm.

As the colorant, a material obtained by dissolving a hydrophilic dye in a hydrophilic solvent can be used. As an example of the solvent, a high-purity water mixed with a glycol derivative such as ethylene glycol or propylene glycol, a carbitol derivative, glycerin, or the like and having its characteristics adjusted can be used. Further, various additives may be added to control the characteristics of the coloring material. Ink jet inks can be used in a wide range. However, it is not always necessary to achieve the high purity required for ink jet. As the colorant, a pigment dispersed in a lipophilic solvent can also be used. A coloring material in which a pigment is dispersed can also be used.

The material of the colored layer is required to have a property of absorbing a coloring material, be chemically stable, and have excellent transparency to visible light. As a material for the colored layer used in the present invention, any material that can be cured by light irradiation, heating, or treatment of light irradiation and heating can be used.
For example, a hydrophilic acrylic resin, an epoxy resin, a silicone resin, or a cellulose derivative such as methyl cellulose or ethyl cellulose is used.

A photopolymerization initiator (crosslinking agent) may be used to crosslink and cure these resins by light or light and heat. As the photopolymerization initiator, dichromate, bisazide compound, radical initiator, cationic initiator,
An anionic initiator or the like can be used. Further, these photopolymerization initiators can be mixed or used in combination with other sensitizers. Note that heat treatment may be performed after light irradiation in order to further advance the crosslinking reaction. In order to select the wavelength of the light to be irradiated so that the colored film is as transparent as possible to visible light, ultraviolet rays may be used if necessary.
I-line having a main peak near 365 nm and deep UV light containing much shorter wavelength components near 254 nm can also be used.

Next, the liquid crystal element of the present invention will be described. In the liquid crystal element of the present invention, a ferroelectric liquid crystal is arranged between a pair of substrates on which transparent electrodes are formed, and the plurality of colored layers described above are laminated between at least one of the transparent electrodes and the substrate to form a plurality of different colors. It has a color filter having a fine pixel portion.

One specific example of the liquid crystal element of the present invention has a structure as shown in FIG. 2 as shown in FIG.
It is provided with a plurality of glass substrates 39a and 39b, and a light shielding film 40 having a pixel opening is formed on one of the glass substrates 39b, and color filters 41a to 41c formed by the method of the present invention are laminated thereon. . The protective layer 42 of the color filter, the wiring 43, and the wiring 43 further thereon
The pixel electrode 44 of ITO which is electrically connected to is laminated, and the orientation control film 48b is formed on the surface thereof. The wiring 50, the ITO electrode 49, and the orientation control film 48 are formed on the other glass substrate 39a.
a is laminated in this order.

The glass substrates on which the film has been thus formed are fixed to each other with an adhesive 45 with a spacer 47 interposed therebetween as shown in FIG. A liquid crystal, for example, a smectic liquid crystal, a nematic liquid crystal, etc., preferably a ferroelectric chiral smectic liquid crystal is injected into the cell gap 46 held by the spacer 47 after sealing the edge portions of the two glass substrates bonded together. Polarizing plates 51a and 51b are attached to the back and front of the liquid crystal element thus formed, and a drive circuit is connected to the wiring. A display device is obtained by incorporating the above elements into a frame incorporating a backlight.

[0055]

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

Example 1 A method for producing a color filter for a liquid crystal display in which red, blue and green three color pixels are regularly arranged will be described.

100 nm of Cr was sputtered on an alkali-free glass substrate from which dirt was sufficiently removed by washing.
To a thickness of. Next, Cr is removed in a predetermined pattern by photolithography to form an opening, thereby forming a Bragg matrix (BM).

Next, a color filter is formed in the same procedure as shown in FIGS. First, a photocurable resin composition comprising 96% by weight of a bisphenol A type epoxy resin and 4% by weight of a cationic initiator was applied as a red colored layer on the above glass substrate with BM to a thickness of about 2 μm by a spin coating method. Prebaking is performed at 90 ° C. for 25 minutes to form a colored layer.

Next, although the pattern is almost the same as BM, BM
Of the colored layer on the BM opening through a photomask having an opening slightly narrower than the opening of
Post-bake at 0 ° C. for 10 minutes to cure the exposed areas on the BM so that the colorant is not absorbed. Red,
The blue and green pixels are arranged at intervals of about 20 μm.

An opening for coloring the red coloring material into red by flat plate offset printing using a printing plate having a pattern matched with the uncured portion of the colored layer and formed with only red pixels and a blanket cylinder having a rubber surface. Part of the colored layer is printed and absorbed. Water is used as the main component of the solvent of the coloring material, and a solution in which a hydrophilic dye (CI Acid Red 35) is dissolved is used. After the red coloring is completed, the glass substrate is heated at 250 ° C. for 30 minutes to completely cure the uncured pixel portion, and only the red pixels are colored to form a color filter portion.

On the surface of the red colored layer which has been colored and cured, the photocurable composition comprising 96% by weight of the above-mentioned bisphenol A type epoxy resin and 4% by weight of a cationic initiator is prepared by the same procedure as for the red colored layer. The resin composition was applied as a blue colored layer by a spin coating method to a thickness of about 2 μm,
Pre-baking is performed for 25 minutes to form a colored layer.

Next, although the pattern is almost the same as BM, BM
The colored layer on the BM opening is exposed to ultraviolet light through a photomask having an opening slightly narrower than the opening of
Post-bake at 0 ° C. for 10 minutes to cure the exposed areas on the BM so that the colorant is not absorbed. Using a printing plate that has a pattern that matches the uncured portion of this colored layer and has only blue pixels formed on it, and a blanket cylinder with a rubber surface, the blue coloring material is colored blue by flat plate offset printing. Print on layers to absorb.

Water is used as the main component of the colorant solvent,
A hydrophilic dye (CI Direct Blue 8
A solution obtained by dissolving 6) is used. After the blue coloring is completed, heat the glass substrate at 250 ° C for 30 minutes,
The uncured pixel portion is also completely cured. In this way, a color filter section in which a colored layer colored only in blue pixels is laminated on a red colored layer colored only in red pixels is formed.

The green colored layer in which the green pixel portion is colored green is formed on the blue colored layer in the same manner as the above procedure in which the blue colored layer is laminated on the red colored layer.

For the green colored layer, a photocurable resin composition containing 96% by weight of a bisphenol A type epoxy resin and 4% by weight of a cationic initiator is used. Water is used as the main component of the solvent of the green colorant, and a solvent in which a hydrophilic dye (PC Green FOP) is dissolved is used.

In this way, a color filter section in which red, blue and green pixels are arranged can be formed. An acrylic resin was applied to this surface by spin coating to a thickness of about 1 μm to form a protective film.

When the color filter thus formed was observed with an optical microscope, no color mixing occurred, and the red, blue, and green pixels were regularly arranged to have good color reproducibility, and the surface was very flat. A color filter was obtained.

Example 2 A black photosensitive resin in which pigments of six colors of red, blue, green, cyan, violet, and yellow were dispersed on a non-alkali glass substrate from which stains were sufficiently removed by washing to about 1 μm.
To the thickness of B, and an opening is formed by the photolithography method.
Form M.

A color filter is formed on this by the same procedure as in the first embodiment. First, a water-soluble negative resist prepared by mixing 97% by weight of polyvinylpyrrolidone and 3% by weight of a bisazide compound as a photoinitiator on the above glass substrate with BM is applied to a thickness of about 3 μm with a Mayer bar coater, and 90
Prebaking is performed at 20 ° C. for 20 minutes to form a photocurable colored layer.

Next, although the pattern is almost the same as BM, BM
Of the colored layer on the BM opening through a photomask having an opening slightly narrower than the opening of
Post-baking is performed at 0 ° C. for 15 minutes to cure the exposed area on the BM so that the coloring material is not absorbed. Red,
The blue and green pixels are arranged at about 20 μ intervals.

An opening for coloring the red coloring material to red by flat plate offset printing using a printing plate having a pattern matching only the uncured portion of the colored layer and formed with only red pixels and a blanket cylinder having a rubber surface. Part of the colored layer is printed and absorbed. Water is used as the main component of the solvent of the coloring material, and a solution in which a hydrophilic dye (Red 137P) is dissolved is used. After the red coloring is completed, 250 together with the glass substrate
By heating at 30 ° C. for 30 minutes, the uncured pixel portion is completely cured, and only the red pixels are colored to form a color filter portion.

On the surface of the red colored layer which had been colored and cured, 97% by weight of the above polyvinylpyrrolidone and 3% by weight of a bisazide compound as a photoinitiator were mixed in the same procedure as that for the red colored layer. The resist is applied to a thickness of about 3 μm with a Meyer bar coater and prebaked at 90 ° C. for 20 minutes to form a photocurable colored layer.

Next, although the pattern is almost the same as BM, BM
Of the colored layer on the BM opening through a photomask having an opening slightly narrower than the opening of
Post-bake at 0 ° C. for 15 minutes to cure the exposed areas on the BM and prevent the colorant from being absorbed. Using a printing plate that has a pattern that matches the uncured portion of this colored layer and has only blue pixels formed on it, and a blanket cylinder with a rubber surface, the blue coloring material is colored blue by flat plate offset printing. Print on layers to absorb.

Water is used as the main component of the solvent of the coloring material,
A solution in which a hydrophilic dye (PC Blue 50P) is dissolved is used. After the blue coloring is completed, the glass substrate is heated at 250 ° C. for 30 minutes to completely cure the uncured pixel portion. In this way, a color filter section in which a colored layer colored only in blue pixels is laminated on a red colored layer colored only in red pixels is formed.

The green colored layer in which the green pixel portion is colored green is formed on the blue colored layer in the same manner as the above procedure in which the blue colored layer is laminated on the red colored layer.

For the green colored layer, a water-soluble negative resist containing 97% by weight of the above polyvinylpyrrolidone and 3% by weight of a bisazide compound as a photoinitiator is used. Further, water is used as the main component of the solvent of the green colorant, and a solvent in which a hydrophilic dye (320ABG) is dissolved is used.

In this way, a color filter section in which red, blue and green pixels are arranged can be formed. An acrylic resin was applied to this surface by spin coating to a thickness of about 1 μm to form a protective film.

When the color filter thus formed was observed with an optical microscope, no color mixing occurred, and the red, blue, and green pixels were regularly arranged to have good color reproducibility, and the surface was very flat. A color filter was obtained.

Example 3 A method for producing a color filter for a liquid crystal display in which red, blue and green three color pixels are regularly arranged will be described.

100 nm of Cr was sputtered on a non-alkali glass substrate from which dirt was sufficiently removed by washing.
To a thickness of. Next, Cr is removed in a predetermined pattern by photolithography to form an opening, thereby forming a Bragg matrix (BM).

Next, a color filter is formed by the same procedure as shown in FIGS. First, a photocurable resin composition comprising 96% by weight of a bisphenol A type epoxy resin and 4% by weight of a cationic initiator was applied as a red colored layer on the above glass substrate with BM to a thickness of about 2 μm by a spin coating method. Prebaking is performed at 90 ° C. for 25 minutes to form a colored layer.

Next, although the pattern is almost the same as BM, BM
Of the colored layer on the BM opening through a photomask having an opening slightly narrower than the opening of
Post-bake at 0 ° C. for 10 minutes to cure the exposed areas on the BM so that the colorant is not absorbed. Red,
The blue and green pixels are arranged at intervals of about 25 μm.

Screen printing is performed using a screen having a pattern matched to the uncured portion of the colored layer and only the red pixels are formed, and the red coloring material is printed on the colored layer in the opening portion for coloring red and absorbed. Let Water is used as the main component of the solvent of the coloring material, and a solution in which a hydrophilic dye (CI Acid Red 35) is dissolved is used. After the red coloring is completed, the glass substrate is heated at 250 ° C. for 30 minutes to completely cure the uncured pixel portion, and only the red pixels are colored to form a color filter portion.

On the surface of the red colored layer which had been colored and was cured, the photocurable composition comprising 96% by weight of the above bisphenol A type epoxy resin and 4% by weight of a cationic initiator was prepared by the same procedure as for the red colored layer. The resin composition was applied as a blue colored layer by a spin coating method to a thickness of about 2 μm,
Pre-baking is performed for 25 minutes to form a colored layer.

Next, although the pattern is almost the same as BM, BM
The colored layer on the BM opening is exposed to ultraviolet light through a photomask having an opening slightly narrower than the opening of
Post-bake at 0 ° C. for 10 minutes to cure the exposed areas on the BM so that the colorant is not absorbed. By screen printing using a screen in which only blue pixels have a pattern that matches the uncured portion of this colored layer,
The blue coloring material is printed on the coloring layer of the opening for coloring blue to absorb it.

Water is used as the main component of the solvent of the coloring material,
A hydrophilic dye (CI Direct Blue 8
A solution obtained by dissolving 6) is used. After the blue coloring is completed, heat the glass substrate at 250 ° C for 30 minutes,
The uncured pixel portion is also completely cured. In this way, a color filter section in which a colored layer colored only in blue pixels is laminated on a red colored layer colored only in red pixels is formed.

The green colored layer in which the green pixel portion is colored green is formed on the blue colored layer in the same manner as the above procedure in which the blue colored layer is laminated on the red colored layer.

For the green colored layer, a photocurable resin composition containing 96% by weight of a bisphenol A type epoxy resin and 4% by weight of a cationic initiator is used. Water is used as the main component of the solvent of the green colorant, and a solvent in which a hydrophilic dye (PC Green FOP) is dissolved is used.

Thus, a color filter section in which red, blue, and green pixels are arranged can be formed. An acrylic resin was applied to this surface by spin coating to a thickness of about 1 μm to form a protective film.

When the color filter thus formed was observed with an optical microscope, no color mixing occurred, and the red, blue, and green pixels were regularly arranged to have good color reproducibility, and the surface was very flat. A color filter was obtained.

Example 4 By the same method as in Example 1, a coloring layer having a pixel portion which absorbs a coloring material and a color mixing prevention region which does not absorb the coloring material on BM is formed on non-alkali glass. A gravure roll that completely matches the red pixel portion is prepared, and a red coloring material is printed on the red pixel portion of this colored layer by gravure printing. After printing the red pixels, the entire colored layer of the red pixels is heat-cured and the surface is washed.

Similarly, a blue colored layer in which a blue coloring material is printed on the blue pixel portion is formed on the red coloring layer, and a green coloring material is printed on the green coloring portion on the green pixel portion. The colored layers of are sequentially formed. After printing all the colors, the whole is heat-cured, and a similar protective layer is further formed thereon to form a color filter.

The color filter thus produced had good color reproducibility with no color mixture between pixels, and exhibited good characteristics with excellent surface flatness.

Example 5 A color filter having a protective layer on its surface is formed on an alkali-free glass by offset printing in the same manner as in Example 1.

Wirings and transparent segment electrodes are formed on this color filter in accordance with each pixel by a sputtering method and a photolithography method, and an alignment film is applied on the wirings and rubbing to give orientation.

On a similar alkali-free glass prepared separately, a transparent common electrode is formed and an alignment film is formed. The SiO ₂ particles having a diameter of about 2 μm are used as spacers to join the above two glasses with the glass surfaces facing outward, and a ferroelectric liquid crystal is injected into a gap of about 2 μm between them to completely seal the glass. A polarizing plate was attached to the surface of the above-mentioned two sheets of glass to form a liquid crystal display panel. When the panel thus obtained was driven to display an image, a good image was obtained.

[0097]

As described above, according to the present invention, it is possible to improve the low pattern forming accuracy, which is a drawback of the printing method, which has the advantages that the process is simple and the capital investment can be suppressed. It is possible to obtain a highly accurate color filter having no color mixture, high color reproducibility, and high surface flatness at low cost.

Further, according to the present invention, it is possible to obtain a liquid crystal element which can obtain a good image by using the above-mentioned highly accurate color filter.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a color filter of the invention.

FIG. 2 is a process drawing showing a previous process of the method for manufacturing a color filter of the present invention.

FIG. 3 is a process drawing showing an intermediate step of the method for manufacturing a color filter of the present invention.

FIG. 4 is a process drawing showing a post-process of the method for manufacturing a color filter of the present invention.

FIG. 5 is a schematic sectional view showing an example of a liquid crystal element of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 transparent substrate 2 light-shielding film 3 first colored layer 4 exposure 5 blanket cylinder 6 first colored portion 7 pixel portion 7a first colored pixel portion 7b second colored pixel portion 7c third Pixel portion of color 8 Cross-linked cured portion 9 Light or heat 10 Colored layer of second color 11 Blanket cylinder 12 Colored portion of second color 13 Colored layer of third color 14 Blanket cylinder 15 Colored portion of third color 16 Colored Layer of First Color 17 Colored Layer of Second Color 18 Colored Layer of Third Color 21 Transparent Substrate 22 Light-Shielding Film 23 First Colored Layer 24 Second Colored Layer 25 Third Colored Layer 26 Colored part of 1 color 28 Colored part 29 Protective layer 30 Pixel part 30 Pixel part 31 Opening 31a Opening 31b in which pixels of the first color are formed 31b Opening 31c in which pixels of the second color are formed 31c Third Openings 39a, 39b in which pixels of different colors are formed Plate 40 light-shielding film 40 41a to 41c color filter 42 protective layer 43, 50 wiring 44 pixel electrode 45 adhesive 46 cell gap 47 Spacer 48a, 48b alignment layer 49 ITO electrodes 51a, 51b polarizing plate

Claims (3)

[Claims] 1. A color filter having a plurality of fine pixel portions of different colors on the same transparent substrate, a light-shielding film having a plurality of openings formed at positions where the pixel portions are provided, and a plurality of different colors of the pixel portions. And a plurality of colored layers, each of which is formed of a visible light transparent material and has a colored portion colored in the same color in a portion corresponding to the opening of the light shielding film. Each of the colored layers is laminated so that the colored parts colored with different colors of the colored layer do not overlap with each other, and the respective colored parts are different from each other through the openings of the light shielding film. A color filter characterized by forming a pixel portion in which colors are arranged. 2. A method of manufacturing a color filter having a plurality of fine pixel portions of different colors on the same transparent substrate, 1) providing a first colored layer made of a visible light transparent material on the transparent substrate. , 2) a step of curing the visible light transparent material in an area other than the area of the first color pixel of the colored layer to form a color prevention area, and 3) forming a color prevention area in the area of the first color pixel. Supplying a coloring material of a first color by printing to form a colored part, 4) curing the colored first colored layer, and 5) forming a colored portion on the first colored layer. 1) a step of laminating a colored layer made of a visible light transparent material different from the 1st colored layer and 6) coloring the color different from the first color by repeating the steps 2) to 5), The number of different colored layers and the same number of colored layers are laminated, and the colored portions of each colored layer overlap each other. A method for producing a color filter, which is characterized by forming without a break. 3. A liquid crystal element in which liquid crystal is arranged between a pair of substrates on which transparent electrodes are formed, wherein at least one of the substrates is a substrate having a color filter according to claim 1. .