JPH02228605A - Production of color filter - Google Patents

Abstract

PURPOSE:To improve the quality of a color display by forming a high-polymer resin film consisting of polyimide, etc., by a coating method on a transparent insulating substrate, half-curing the surface layer by heating using irradiation of heat rays, etc., and pressurizing the surface layer uniformly by a pressurizing means, etc., to flatten the layer, then thermally curing the resin film. CONSTITUTION:The high-polymer resin material consisting of the polyimide, etc., is applied on the transparent substrate 1 formed with the color filters 2 having plural colors of dyestuff film patterns of different film thicknesses to form the high-polymer resin film 21. The surface of the formed high-polymer resin film 21 is heated to half cure the surface layer thereof; thereafter, the surface of the resin film is flattened by a pressurizing means 32 and the entire part of the high-polymer resin film 21 having the flattened surface is further thermally cured. The surface of the color filters having plural colors of the dyestuff film patterns 2a to 2c of different film thicknesses is, therefore, easily flattened by the high-polymer resin film 21 of the min. required thickness. The gap for sealing a liquid crystal is uniformized in this way and the reproducibility of the colors of the color display is improved without having unequal colors and the change in the color tones. The display quality is thus improved.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for manufacturing a color filter that is incorporated into a liquid crystal display device for color display, the surface of a polymer resin film formed on a plurality of color filters with different film thicknesses can be easily formed. The purpose of this technology is to flatten the surface of the film to enable color display without color unevenness or color tone changes. The process of applying a resin material to form a polymer resin film, heating the surface of the formed polymer resin film to semi-cure the surface layer, and then flattening the surface of the resin film using pressure means. and a step of thermally curing the entire polymer resin film whose surface has been flattened.

[Industrial application field]

The present invention relates to a method for manufacturing a color filter that is incorporated into a two-layer STN liquid crystal display device or the like for color display.

In recent years, display STN (Super Twist)
d Nematic) overlapping the liquid crystal layer and the optical compensation layer,
A simple matrix type black and white display liquid crystal panel, which has a structure in which coloration caused by birefringence of the display STN liquid crystal layer is compensated for by an optical compensation layer, is being actively developed. In combination, there is a demand for the realization of a color liquid crystal display device with good color characteristics and capable of large-capacity display.

The color filters incorporated into such a color liquid crystal display device include red (R) and green (G).

Since the intensity of light transmitted through each of the plurality of pigment film patterns made of blue (B) differs depending on the color,
The thickness of each dye film pattern is made to vary according to the light intensity, and the gap between the liquid crystals is kept constant by controlling the distance between each dye film having different thicknesses and the liquid crystal layer provided above. The difference in color tone is adjusted by

Therefore, there is a need for a method for manufacturing a color filter having a flat surface in which the distance between each dye film having different thicknesses and the liquid crystal layer provided above can be easily controlled without changing the thickness of the liquid crystal layer. It is said that

[Conventional technology]

Conventionally, a color liquid crystal display device that combines a two-layer STN liquid crystal display device and a color filter is constructed as shown in FIG. That is, the two-layer STN liquid crystal display device is
Striped transparent electrodes 4 are formed perpendicularly to each other on opposing surfaces of a pair of transparent insulating substrates 1.9 arranged oppositely.
．． 8, a display liquid crystal panel P1 on which an alignment film 5.7 is disposed, and an STN liquid crystal layer 6 sealed between the alignment films 5.7, and a pair of transparent insulating substrates 1 similarly arranged facing each other.
A compensating liquid crystal panel P2 in which an STN liquid crystal layer 13 having liquid crystal molecules twisted in a direction opposite to the twist direction of the liquid crystal molecules in the STN liquid crystal layer 6 is enclosed between alignment films 12 and 15 through alignment films 12 and 15. One transparent insulating substrate 1 in the display liquid crystal panel P1, which is configured to be stacked one on top of the other,
and the transparent electrode 4, red (R).

A color filter 2 having a plurality of green (G) and blue (B) dye film patterns 2a, 2b, and 2c having different film thicknesses is placed between the intersection of the transparent electrodes 4 and 8 and each of the dye film patterns 2a, 2b. . The structure is such that a resin film 3 is interposed therebetween.

[Problem to be solved by the invention]

By the way, when realizing a color liquid crystal display device having the above-mentioned configuration, since the intensity of light transmitted through the color filter 2 differs depending on the color, red (R) and green (G) are used as the color filter 2.
), each blue (B) dye film pattern 2a.

Differences in color tone are adjusted and protected by making the film thicknesses of the pigment film patterns 2b and 2c different and by controlling the spacing between the liquid crystal layers 6 provided above each of the pigment film patterns 2a, 2b, and 2c. A resin film 3 for this purpose is provided by a coating method or the like.

However, as shown in FIG.
Since the resin film 3 is formed on the color filters 2b and 2c only by a coating method and a heat curing process, the surface of the resin film 3 is uneven on each color filter 2 and has poor flatness. For this reason, an STN is provided on the resin film 3 via a transparent electrode 4 and an alignment film 5.
There is a problem in that the thickness of the liquid crystal layer 6, that is, the sealing gap thereof becomes non-uniform, causing color unevenness and changes in color tone, resulting in a significant deterioration of color display quality.

In view of the above-mentioned conventional problems, the present invention has been developed to easily flatten the surface of a polymer resin film formed on a color filter having a pigment film pattern of multiple colors with different film thicknesses, thereby eliminating color unevenness and color tone changes. The object of the present invention is to provide a method for producing a color fill that enables color display.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention forms a polymer resin film by coating a polymer resin material such as polyimide on a transparent substrate on which a color filter having a pigment film pattern of a plurality of colors with different film thicknesses is formed. After heating the surface of the formed polymer resin film to semi-cure the surface layer, a step of flattening the surface of the resin film with a pressure means is performed to flatten the surface. The entire polymer resin film is further configured to be thermally cured.

[For production]

In the manufacturing method of the present invention, a polymer resin film made of polyimide or the like is formed by a coating method on a transparent insulating substrate on which a color filter having a dye film pattern of a plurality of colors with different film thicknesses is formed. The surface layer is semi-cured by heating with heat ray irradiation, etc., and the surface of the resin film is evenly pressed and flattened by pressure means such as a pressure roller, press processing, or vacuum pack method, and then the entire resin film is Since it is thermoset, the flatness of the surface of the resin film provided on the color filter is improved, and the thickness of the resin film can be reduced to the minimum necessary thickness.

Therefore, when combined with a two-layer STN liquid crystal display device, the reproducibility of color display is good and the quality of color display is improved.

(Example) Examples of the present invention will be described in detail below using the drawings.

FIGS. 1(a) to 1(C) are sectional views of main parts showing the first embodiment of the method for manufacturing a color filter according to the present invention in the order of steps.

First, as shown in FIG. 1(a), a film of red (R), green (G), and blue (B) with a thickness (1.5 to 1.8 μ-) is deposited on a transparent insulating glass substrate 1. A color filter 2 having a plurality of dye film patterns 2a, 2b, and 2c having different colors is formed, and a polymeric resin material made of, for example, polyimide is applied onto the color filter 2 to a thickness of 1.0 μm.

Thereafter, the surface of the polymer resin film 21 made of polyimide formed on the color filter 2 is heated at 200° C. for 15 seconds by irradiation with heat rays such as infrared rays to semi-cure only the surface layer.

Next, as shown in FIG. 1(B), the glass substrate 1 having the resin film 21 with only the surface layer semi-cured is placed on the flat plate stand 31.
A pressure means consisting of a pressure roller 32 placed above the glass substrate 1 is moved in the direction of arrow A to uniformly press the surface of the resin film 21. After applying pressure to flatten the resin film 21, the entire flattened resin film 21 is heated to 200° C.
By heating and curing for 60 minutes at
As shown in C), a desired color filter 2 having a resin film 21 with a flattened surface can be easily obtained.

Therefore, by incorporating the color filter 2 obtained by such a forming method into a two-layer STN liquid crystal display device to perform color display, it is possible to reduce the thickness of the STN liquid crystal layer in the display liquid crystal panel, that is, the liquid crystal encapsulation. The gap becomes uniform, there is no color unevenness or change in color tone, and color display quality is improved.

Moreover, FIGS. 2(a) to 2(C) are sectional views of main parts showing the second embodiment of the method for manufacturing a color filter according to the present invention in order of steps.

The second embodiment shown in these figures is shown in FIGS.
) The difference from the first embodiment shown in FIG. , 2c, the surface of a resin film 21 made of polyimide or the like coated to a thickness of 1.0 μ- is heated at 200° C. for 15 seconds by irradiation with heat rays such as infrared rays to remove only the surface layer. After semi-curing, the glass substrate l in that state is placed on a mounting flat plate stand 41 which is placed opposite to the pressurizing flat plate 42 in the press device, as shown in FIG. 2(c), and only the surface layer is removed. The surface of the resin film 210 is flattened by applying pressure evenly on the semi-cured resin film 21 using the pressing flat plate 42 . after that,
By heating and curing the entire flattened resin film 21 at 200° C. for 60 minutes using a heater heating device or the like,
A resin film 2 with a flattened surface as shown in FIG. 2(C)
1 is obtained.

The method of this second embodiment can also achieve the same object as the method of the first embodiment.

Furthermore, FIGS. 3(a) to 3(C) are sectional views of main parts showing the third embodiment of the method for manufacturing a color filter according to the present invention in order of steps.

The difference between this third embodiment and the first embodiment is that, as shown in FIG. Pattern 2a, 2b, 2
The surface of a resin film 21 made of polyimide or the like coated to a thickness of 1.0 μm on the color filter 2 having a color filter 2 is heated at 200° C. for 15 seconds by irradiation with heat rays such as infrared rays to partially remove only the surface layer. After curing, the glass substrate 1 in that state is placed between a pair of pressing flat plates 52 and 53 that are placed opposite each other in the vacuum bag 51.

Then, as shown in FIG. 3(b), the inside of the vacuum bag 52 is pumped to a pressure of 10-"torr by a vacuum evacuation device (not shown).
At a certain degree of vacuum, the pair of pressing flat plates 52 and 53 are each moved toward the center of the vacuum bag 51 by atmospheric pressure, and the surface of the resin film 21 is flattened by uniformly pressurizing it. By continuing to heat the entire flattened resin film 21 at 200° C. for 60 minutes and curing it, the resin film 21 has a flattened surface as shown in FIG. 3(C). The purpose is to obtain a desired color filter 2.

The method of the third embodiment can also achieve the same object as the method of the first embodiment.

〔Effect of the invention〕

As is clear from the above description, according to the method for manufacturing a color filter according to the present invention, the surface of a color filter having a pigment film pattern of a plurality of colors with different film thicknesses is coated with a resin film having a thickness of the minimum necessary thickness. The thin polymer resin film allows easy planarization. Therefore, by combining a color filter with such a formation method in a two-layer STN liquid crystal display device, etc., it is possible to make the thickness of the liquid crystal layer in the display liquid crystal panel, that is, the liquid crystal filling gap, uniform. As a result, there is no color unevenness or change in color tone, the reproducibility of color display is good, display quality is improved, and other excellent effects are achieved.

[Brief explanation of the drawing]

FIGS. 1(a) to (C) are cross-sectional views of main parts showing the first embodiment of the method for producing a color filter according to the present invention in order of steps, and FIGS. 2(a) to (C) are color filters according to the present invention. FIGS. 3(a) to 3(C) are cross-sectional views of main parts showing a second embodiment of a method for manufacturing a filter in order of steps; FIGS. 4 is a configuration explanatory diagram for explaining a two-layer STN liquid crystal color display device, and FIG. 5 is a sectional view of a main part for explaining problems of a conventional color filter. (α) cb) In Figures 1) to (C) to Figures 3 (a) to (C),
1 is a glass substrate, 2 is a color filter, 2a, 2b,
2c is a dye film pattern, 21 is a resin film, 31 and 41 are a mounting plate base, 32 is a pressure roller, 42 is a pressure plate, 51
52 and 53 indicate a vacuum bag and a pressing flat plate, respectively. (C3, [F3yI Mezai 1 Sharp Serving Bonkosha Rei 1; Tree 11 Le Eye Closed 1st Figure + b) Figure (CJ, IN's Moon Meshi r 3 Trade 1 Case to Enezuka Tsu!r Show Hei 4
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Claims (2)

[Claims] (1) Pigment film patterns of multiple colors with different film thicknesses (2a, 2
b, 2c) on the transparent substrate (1) on which the color filter (2) is formed, a step of forming a polymer resin film (21), and heating the surface of the formed polymer resin film (21). a step of flattening the surface of the resin film (21) with a pressure means after semi-curing the surface layer; and a step of thermosetting the entire surface of the polymer resin film (21) with the flattened surface. A method for producing a color filter, comprising: (2) The method for manufacturing a color filter according to claim 1, wherein the polymer resin film (21) is made of polyimide.