JPH04261503A - Manufacture of color filter - Google Patents

Abstract

PURPOSE:To enlarge the size of an image and to reduce cost. CONSTITUTION:Each color element is formed on a flexible sheet 30 and the sheet 30 is fixed with an adhesive 40 to the side of a transparent substrate 20, such as glass.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for manufacturing color filters used in color display panels such as liquid crystal color televisions, and in particular to a technology effective for increasing the screen size and reducing costs.

0002

[Prior art and its problems] In general, this type of color filter basically consists of multiple color pixels having different spectral characteristics such as red, green, and blue on one side of a transparent substrate such as a glass substrate. In many cases, a light-shielding pattern is provided at the boundary between each color pixel. The light-shielding pattern is said to be effective in increasing the clarity of images displayed by the display panel. Such a color filter performs not only a color display function but also a liquid crystal support function in a display panel. Therefore, conventionally, substrates for forming color pixels have to be rigid enough to support liquid crystals, such as glass substrates, that is, they can maintain a certain shape by themselves. It is used.

On the other hand, in recent years, color filters have been made larger in size, for example, 30 cm x 30 cm, and at the same time, there is a demand for lower costs. Therefore, a manufacturing method suitable for larger screens and lower costs is desired, but in cost-effective technologies such as inkjet methods, printing methods, and transfer methods, the rigidity of the transparent substrate is insufficient for color pixels. It becomes an obstacle in forming. Further, as screens become larger, inspection and correction techniques for each color pixel are indispensable, but it is disadvantageous in terms of efficiency to inspect and correct them at the stage of forming a single glass substrate or the like. The method for manufacturing color filters using the inkjet method is described in Japanese Patent Application Laid-Open No. 59-75.
No. 205, regarding the manufacturing method using the printing method,
No. 28738, and regarding the manufacturing method using the transfer method,
Each publication of JP-A-2-176703 shows an example of each.

0004

OBJECTS OF THE INVENTION An object of the present invention is to provide a technique that is advantageous in reducing costs even when the screen is enlarged.

[0005]

[Means and effects thereof] In the present invention, after each color pixel is formed on a flexible transparent film, the film is bonded and fixed to a transparent substrate such as glass having a rigidity higher than a predetermined value. In that case, it is preferable that the light-shielding pattern covering the boundary area of each color pixel be formed in advance on the transparent substrate side. This is because a clearer display image can be obtained and it can also be used as a reference for positioning when bonding a film and a transparent substrate to each other. Since the flexible film can be wound up, pixels of each color can be formed efficiently using the above-mentioned cost-effective manufacturing method, and it is also very convenient for inspecting and correcting the formed pixels of each color. good. The method of forming color pixels on a film is not limited, but an inkjet method, in particular a method that uses high viscosity ink, performs overlapping spraying with the same dot diameter, and controls the transmission density. is preferred. In the color filter obtained by this invention, each color pixel is sandwiched between a film and a transparent substrate with a transparent adhesive sandwiched between them, so there is no need for a so-called overlay process to protect the color pixels. Furthermore, the surface of the color filter can also be made flat.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a cross-sectional structure of a color filter 10 for liquid crystal display manufactured according to the present invention. The color filter 10 has a structure in which a transparent glass substrate 20 and a flexible plastic sheet 30 are bonded to each other with a transparent adhesive 40 and integrated. The glass substrate 20 has a first surface 21 and a second surface 22 that are parallel to each other, and has a thickness of about 1 to 2 mm. Therefore, it goes without saying that the glass substrate 20 can maintain a certain shape by itself. This glass substrate has a first surface 21
A light shielding pattern 50 is previously formed on the side. The light shielding pattern is made of metal chromium, and its thickness is very thin, on the order of 0.1 μm. On the other hand, the plastic sheet 30 overlapping the glass substrate 20 has a thickness of, for example, about 20 to 50 μm, and can be relatively freely deformed. sheet 3
In addition to transparency, a material with high surface smoothness, heat resistance, and dimensional stability is preferable as the material 0. For example, polycarbonate, polyimide, polyethylene terephthalate, etc. can be used. This sheet 30 also has a first surface 31 and a second surface 32 that are parallel to each other, and color pixels 60 of three colors, red, green, and blue, are formed in advance on the first surface side. When forming these color pixels 60, a cost-effective method such as an inkjet method, a printing method, or a transfer method is used, and since the sheet 30 is flexible, it can be efficiently performed by a winding method. Among these, the inkjet method is preferred. In the inkjet method, a piezo element is driven by ultrasonic waves to eject ink drop by drop from a capillary nozzle, but in this case, the viscosity of the ink is set slightly higher, and multiple sprays are applied to obtain a predetermined permeation viscosity. For example, when the size of each color pixel 60 is 160 μm x 160 μm, the ink diameter is 40 μm.
Color pixels 60 having a predetermined shape and transmission density are sequentially formed by spraying a plurality of particles of about .mu.m so as to fill the color pixel area. In this invention, sheet 3
0 is adhered and fixed to the first surface 21 of the glass substrate 20 using the first surface 31 side on which the color pixels 60 are formed as the adhesive surface. Prior to this fixing, the sheet 30 or the glass substrate 20
The adhesive 40 is applied to one side of the sheet 30, but from the viewpoint of workability, it is preferable to apply the adhesive to the sheet 30 side that can be rolled up. However, in any case, the adhesive 40 fills the gaps between each color pixel 60 and effectively protects each color pixel 60. Therefore, the material for the adhesive 40 should be one that is not only transparent but also has excellent resistance such as heat resistance and applicability. Note that since the thickness of each color pixel 60 is, for example, about 2 to 3 μm, the layer of adhesive 40 only needs to cover it, and is preferably made as thin as possible. When adhering the sheet 30 and the glass substrate 20, it is important to accurately align each color pixel 60 and the light shielding pattern 50. Therefore, it is desirable to provide positioning standards as well as temperature control during bonding. Usually, so-called register marks are provided, but each color pixel 60 and the light-shielding pattern 50 themselves can also be used as marks for alignment. In the color filter 10 obtained as described above, the second
The surface 32 side faces the liquid crystal. Therefore, each color pixel 60 is closer to a liquid crystal, and the clarity of the displayed image viewed from the second surface 22 side of the glass substrate 20 can be improved. Note that although the light-shielding pattern 50 is useful for increasing the clarity of the displayed image, it may be omitted depending on the type of display device. Further, the light-shielding pattern 50 may be formed not on the transparent substrate 20 side but on the transparent sheet 30 side similarly to the pixels 60 of each color.

[0007]

According to the present invention, after forming each color pixel 60 on the flexible sheet 30, the sheet 30
Since it is fixed by adhering to the side of the transparent substrate 20 such as glass, it is very advantageous in terms of formation of each color pixel 60, inspection and correction thereof. Furthermore, when the sheet 30 and the transparent substrate 20 are bonded together using the adhesive 40, the color pixels 6
Since the side on which 0 is formed is the adhesive surface, each color has 60 pixels.
can be embedded in adhesive 40 and sandwiched between sheet 30 and transparent substrate 20. Thereby, it is possible to obtain a color filter 10 with excellent durability and a flat surface.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a color filter obtained by applying the present invention.

[Explanation of symbols]

10 Color filter 20 Transparent substrate 30 Flexible transparent film 40 Transparent adhesive 50 Shade pattern 60 color pixels

Claims (3)

[Claims] 1. A first step of forming color pixels of a plurality of colors having mutually different spectral characteristics on one side of a flexible transparent film, and after the first step, the side on which the color pixels are formed is used as an adhesive surface. , a second step of fixing the transparent film to one surface of a transparent substrate, which has first and second surfaces parallel to each other and can maintain a certain shape by itself, with a transparent adhesive. How to manufacture filters. 2. The method of manufacturing a color filter according to claim 1, wherein a light-shielding pattern covering the boundary area of the color pixel is provided on one surface of the transparent substrate to which the transparent film is adhered. [Claim 3] The color filter is for liquid crystal display.
The method for manufacturing a color filter according to claim 1 or 2.