JP2016109984A - Color filter, liquid crystal display prepared therewith and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter having a touch panel function and a method of producing the same.SOLUTION: A color filter has a transparent base material, a conductive black matrix formed on a one principal face of the transparent base material where a coloring part is formed, and a conductive electrode formed on the other principal face of the transparent base material where the coloring part is not formed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a color filter having a touch panel function used for a liquid crystal display or the like.

  In recent years, color liquid crystal display devices have formed a large market as liquid crystal color televisions and liquid crystal display device-integrated notebook personal computers. In addition to mobile phones, personal digital assistants, car navigation systems, touch panel type liquid crystal displays that use a touch panel as an input / output device for image information, with the touch panel integrated with the liquid crystal display panel, have become popular in the market. It was.

  There are various types of touch panels, such as a resistive film type, a capacitance type, an ultrasonic method, and an optical method, depending on the structure and detection method. Among these, the capacitive touch panel has a translucent conductive film (translucent electrode) on a single substrate, and has a capacitance formed by contact (touch) with a finger or a pen. The position to be touched is specified by detecting a change in the amount of weak current flowing through the liquid crystal display device, receiving the instructed content as an input signal and driving the liquid crystal display device. A capacitive touch panel that does not have a movable part has high optical characteristics (transmittance), and is superior in durability and operating temperature characteristics to a resistive touch panel.

  Conventionally, when a touch panel type liquid crystal display is manufactured, as disclosed in, for example, Patent Document 1, a technique in which a touch panel electrode and a color filter are formed on separate substrates and bonded together to form a module has been mainstream. However, there were problems in display performance, such as interference fringes due to subtle deviations between the touch panel stripe and the color filter stripe, and parallax in oblique display due to the distance between the touch panel surface and the color filter surface. . Therefore, for example, as disclosed in Patent Document 2 and Patent Document 3, for the purpose of reducing the bonding process between the touch panel electrode and the color filter substrate, and for preventing optical characteristics from being reduced due to the gap generated when the bonding is performed. Techniques for forming touch panel electrodes and color filters on the front and back surfaces of the same glass substrate have been studied.

  Of the technologies for forming the touch panel electrodes and color filters on the front and back of the same glass substrate, the TFT (thin film transistor) -LCD cell with a built-in touch panel function is an in-cell type. An on-cell type has a built-in touch panel function between provided glass substrates. Since the in-cell type needs to incorporate a touch sensor function inside the pixel on the TFT substrate, there is a concern that the yield may decrease. In addition, since the in-cell type incorporates a touch sensor function inside a pixel, the area of an effective display area that can be used for display in the pixel is reduced, and the image quality is deteriorated. On the other hand, since the on-cell type forms an electrode pattern between the color filter substrate and the polarizing plate, it is easy to ensure the yield. In the on-cell type, since the area of the effective display area in the pixel is not reduced, the image quality is hardly deteriorated.

JP 2007-178758 A JP 2008-009750 A JP 2010-072584 A

  By the way, in the conventional on-cell type touch panel, two of the Y electrode pattern and the X electrode pattern for touch sensing are formed on the surface side where the colored layer of the transparent substrate is not applied. For this reason, the layer where the X electrode pattern (or Y electrode pattern) is formed and the layer where the Y electrode pattern (or X electrode pattern) is formed are separated by an insulating layer so that the intersection is not short-circuited. The structure was necessary and the manufacturing process was heavy.

  An object of the present invention is to provide a color filter having a touch panel function and a method for manufacturing the same, which solves this problem.

  One aspect of the present invention for solving the above problems is that a colored black matrix having a conductive color formed on one main surface on which a colored portion of a transparent substrate is formed and a colored portion of a transparent substrate are not formed. It is a color filter provided with the conductive electrode formed on the main surface.

  Further, the sheet resistance of the conductive black matrix may be 270Ω / □ or less.

  Further, the conductive black matrix may include a conductive material made of any of metal nanowires, metal particles, carbon nanotubes, graphite, conductive polymers, or a combination thereof.

  Moreover, among the black matrix having conductivity, a plurality of black matrices formed in parallel in one direction may be electrically connected by a conductive black matrix formed in a direction intersecting with these.

  Further, the conductive electrode may include a conductive material made of any one of ITO, metal mesh, metal nanowire, conductive black matrix resin, or a combination of a plurality of conductive materials.

  Moreover, you may have the touchscreen function which performs the sensing of a touch position by reading the electrostatic capacitance between the black matrix which has electroconductivity, and an electroconductive electrode.

  Further, a TFT substrate and a liquid crystal may be formed on the color filter of the above aspect to form a liquid crystal display.

  Another aspect of the present invention is a step of laminating a pixel layer in which a conductive black matrix is formed on one main surface of a transparent substrate, and a step of sequentially bonding a liquid crystal and a TFT substrate on the pixel layer. And a step of forming a conductive electrode on the other main surface of the transparent base material on which the pixel layer is not laminated.

  Another aspect of the present invention includes a step of laminating a pixel layer in which a conductive black matrix is formed on one main surface of a transparent substrate, and the other main surface of the transparent substrate on which no pixel layer is laminated. And a step of forming a conductive electrode and a step of sequentially bonding a liquid crystal and a TFT substrate on the pixel layer.

  According to the present invention, one electrode pattern (Y or X electrode pattern) is formed with a conductive black matrix resin on one main surface of the color filter where the colored portion is formed, and the colored portion is formed. The other electrode pattern (X or Y electrode pattern) is formed by using a conductive material such as a metal film on the other main surface. Thereby, since touch sensing between the electrode pattern on the one main surface and the electrode pattern on the other main surface can be performed, an on-cell touch panel integrated color filter can be obtained.

It is sectional drawing explaining the structure of the color filter 1 which concerns on one Embodiment of this invention. It is an A direction arrow top view of the color filter 1 shown in FIG. FIG. 2 is a plan view of the color filter 1 shown in FIG. It is sectional drawing explaining the structure of the liquid crystal display using the color filter 1 which concerns on one Embodiment of this invention. It is a figure explaining the manufacturing method of the color filter 1 which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the color filter of the present invention will be described with reference to the drawings.

[Color filter configuration]
FIG. 1 is a cross-sectional view illustrating the configuration of a color filter 1 according to an embodiment of the present invention. FIG. 2 shows a plan view of the color filter 1 shown in FIG. FIG. 3 shows a plan view of the color filter 1 shown in FIG.

  A color filter 1 according to this embodiment shown in FIG. 1 includes a transparent base material 10, a pixel layer 11 laminated on one main surface of the transparent base material 10, and a transparent insulation laminated on the pixel layer 11. The layer 15 and the conductive electrode layer 16 laminated on the other main surface opposite to the one main surface of the transparent substrate 10 are configured. The pixel layer 11 includes a non-conductive black matrix 12, a conductive black matrix 13, a red colored portion 14R, a green colored portion 14G, and a blue colored portion 14B. The conductive electrode layer 16 includes a conductive electrode 16a.

  As shown in FIG. 2, on one main surface of the transparent substrate 10, a red colored portion 14 </ b> R, a green colored portion 14 </ b> G, and a blue colored portion 14 </ b> B are striped parallel to the Y-axis direction of the transparent substrate 10. A plurality are formed side by side in parallel. Further, on one main surface of the transparent substrate 10, a non-conductive black matrix 12 and a conductive black matrix 13 are arranged so as to divide the red colored portion 14R, the green colored portion 14G, and the blue colored portion 14B into pixels, respectively. Crossed and patterned. Here, the conductive black matrix 13 is composed of a plurality of stripe patterns arranged in parallel to the Y-axis direction of the transparent substrate 10. Desirably, the conductive black matrixes 13 arranged in parallel to the Y-axis direction are electrically connected by the conductive black matrix 13 formed in a direction intersecting with the conductive black matrix 13 (X-axis direction of the transparent substrate 10). Has been. Furthermore, an electrode wire 17 for electrically connecting the conductive black matrix 13 to an integrated circuit (IC) used for touch panel control is formed on one main surface of the transparent substrate 10.

  As shown in FIG. 3, a conductive electrode 16 a configured by a plurality of stripe patterns arranged in parallel in the X-axis direction of the transparent substrate 10 is formed on the other main surface of the transparent substrate 10. In addition, an electrode line 17 for electrically connecting the conductive electrode 16a to an integrated circuit (IC) used for touch panel control is formed on the other main surface of the transparent substrate 10.

  As the transparent substrate 10 used in the present invention, one having a transmittance of 80% or more with respect to visible light can be used, and one having a transmittance of 95% or more can be preferably used. Generally, it may be one used for a liquid crystal display device, and an inorganic transparent substrate such as glass or a transparent resin substrate such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate, and cyclic olefin copolymer can be used. These may be used alone or in combination of two or more materials. Since the touch panel function according to the present invention is an electrostatic capacity type, there is no need for distortion due to external force as in the conventional touch screen system, and the material and thickness can be appropriately selected depending on the specifications of the display panel to be applied. A glass substrate is optimal in view of heat resistance.

  The non-conductive black matrix 12 is a black matrix made of a material that does not have conductivity. For this non-conductive black matrix 12, it is desirable to use, for example, an acrylic resin having a thickness of 0.5 to 3.0 μm in which a black pigment is dispersed, but if it is an insulating material having a reflectance of 10% or less, There is no particular limitation.

  The conductive black matrix 13 is a black matrix made of a conductive material. The conductive black matrix 13 is not particularly limited as long as the sheet resistance is 270Ω / □ or less, the film thickness is 0.5 to 3.0 μm, and the reflectance is 10% or less. However, it is desirable to obtain conductivity by mixing the non-conductive black matrix 12 with a conductive material made of metal nanowires, metal particles, carbon nanotubes, graphite, conductive polymers, or a combination thereof. .

  The red colored portion 14R is a portion colored in red. The green coloring portion 14G is a portion colored green. The blue colored portion 14B is a portion colored in blue. The materials of the red coloring portion 14R, the green coloring portion 14G, and the blue coloring portion 14B are made of, for example, an acrylic resin having a thickness of 0.5 to 3.0 μm in which pigments of respective colors are dispersed.

  As a coating method for the non-conductive black matrix 12, the conductive black matrix 13, the red colored portion 14R, the green colored portion 14G, and the blue colored portion 14B, spin coating or spinless coating is usually used. The method is not limited to these as long as it can be applied with a uniform film thickness.

  The transparent insulating layer 15 is formed for the purpose of protecting the red colored portion 14R, the green colored portion 14G, and the blue colored portion 14B. As a material of the transparent insulating layer 15, it can form using a well-known material, For example, organic type materials, such as transparent resin provided with photosensitivity, are mentioned. As the organic material, a UV curable coating composition containing a polymerizable group-containing oligomer, monomer, photopolymerization initiator and other additives can be used.

  The conductive electrode 16a of the conductive electrode layer 16 is made of indium oxide, zinc oxide, tin oxide, or a dry oxide such as a vacuum deposition method or a sputtering method using a material composed of two or three kinds thereof. It is formed by laminating with, or a coating type conductive material such as metal nanowire, PEDOT, carbon nanotube, or conductive black matrix resin is formed by a known coating method such as spin coating, spinless coating, knife coating, etc. However, the material and the laminating method are not particularly limited.

  As a method of forming each of the non-conductive black matrix 12, the conductive black matrix 13, the red colored portion 14R, the green colored portion 14G, the blue colored portion 14B, and the conductive electrode 16a, a photolithography method is usually used. .

  The electrode wire 17 connects the conductive black matrix 13 formed on one main surface of the transparent substrate 10 or the conductive electrode 16a formed on the other main surface of the transparent substrate 10 to an IC used for touch panel control. Formed for the purpose of. Examples of the material of the electrode wire 17 include a conductive metal paste, a conductive metal nanowire, and a thin film metal. A sufficient resistance value is obtained so that the conductive black matrix 13 or the conductive electrode 16a can be electrically connected to the IC. As long as it can be used, there is no particular limitation. Examples of the method for forming the electrode lines 17 include wet coating such as gravure offset printing, screen printing, and flexographic printing, and dry coating such as sputtering, vapor deposition, and CVD, but are not limited thereto.

  In the color filter 1 of the present embodiment, one electrode pattern (Y electrode pattern in this embodiment) for touch sensing is formed on one main surface of the transparent substrate 10 with the conductive black matrix 13. The other electrode pattern (X electrode pattern in this embodiment) for touch sensing is formed of the conductive electrode 16a on the other main surface. With the structure of the color filter 1, the touch position can be determined (sensing) by reading the change in capacitance generated between the conductive black matrix 13 and the conductive electrode 16 a. That is, the color filter 1 of this embodiment can function as the color filter 1 integrated with the on-cell touch panel.

  Since the on-cell touch panel integrated color filter 1 obtained in this way is formed with the X electrode pattern and the Y electrode pattern through the transparent base material 10, the gap between the X electrode pattern and the Y electrode pattern that has been required so far is used. Insulating layer formation is not required, no jumper layer is required at the intersection of electrode patterns, and the electrode pattern is provided by applying the black matrix structure that has always existed in color filters, reducing the manufacturing load. can do.

  Also, as shown in FIG. 4, a liquid crystal display 40 having a touch panel function can be obtained by bonding the color filter 1 integrated with the on-cell touch panel to a known liquid crystal layer 20 and the TFT substrate 30.

[Liquid crystal display manufacturing method]
FIG. 5 is a diagram for explaining an example of a manufacturing method of the liquid crystal display 40 using the color filter 1 according to an embodiment of the present invention.

  First, the transparent base material 10 is prepared (FIG. 5A). On one main surface of the transparent substrate 10, a pattern of a non-conductive black matrix 12 is formed, a pattern of a conductive black matrix 13 is formed, and an electrode line 17 is formed (FIG. 5B). . At this time, it is formed as one electrode pattern used for touch sensing. Subsequently, a red colored portion 14R, a green colored portion 14G, and a blue colored portion 14B are sequentially formed on one main surface of the transparent substrate 10 (FIG. 5C). By this step, the image layer 11 is completed.

  Next, a transparent insulating layer 15 is formed on the image layer 11 (FIG. 5D). Next, the conductive electrode layer 16 and the electrode wire 17 are formed on the other main surface of the transparent substrate 10 (FIG. 5E). Finally, the liquid crystal layer 20 and the TFT substrate 30 are sequentially bonded onto the transparent insulating layer 15 (FIG. 5F). The liquid crystal display 40 is completed through the above steps.

  In the above manufacturing method, the last step of forming the conductive electrode layer 16 and the electrode wire 17 on the other main surface of the transparent substrate 10, that is, the liquid crystal layer 20 and the TFT substrate on the transparent insulating layer 15. You may perform after the process of bonding 30 in order.

[Example]
A non-alkali glass is used as the transparent substrate 10, a non-conductive black matrix resin is applied to one main surface of the glass by a spin coating method, and dried at 100 ° C. for 5 minutes on a hot plate. Dried. After that, exposure was performed through a photomask having a desired opening at 100 mJ / cm ² using a high-pressure mercury lamp as a light source, and then shower development was performed for 30 seconds with a 0.2% by mass sodium bicarbonate aqueous solution. did. After washing with water, heat treatment was performed at 230 ° C. for 30 minutes in a hot air circulation oven to form a non-conductive black matrix 12. Subsequently, a conductive black matrix resin was applied and formed in the same manner as the nonconductive black matrix 12 to form a conductive black matrix 13. Further, the conductive black matrix 13 can be used as a Y pattern electrode for touch sensing, and 100 to 150 pattern lines arranged in parallel to the Y axis direction of the transparent substrate 10 are arranged in a direction perpendicular to the Y axis. It was made into the shape bundled with the pattern line (X-axis direction of the transparent base material 10). At this time, the thickness of the nonconductive black matrix 12 and the conductive black matrix 13 was 2 μm.

  A conductive black matrix resin coating solution was obtained by mixing silver nanowires with a non-conductive black matrix resin. The reflectance of the non-conductive black matrix 12 and the conductive black matrix 13 after the formation was 5 to 8%. Furthermore, the sheet resistance value of the conductive black matrix 13 was 230 to 255Ω / □.

Next, a red colored portion 14R, a green colored portion 14G, and a blue colored portion 14B were sequentially formed with a thickness of 2.5 μm. The forming method is that an acrylic resin colored in each color is applied by a spin coating method, and then cured by exposing the light amount of 100 mJ / cm ² using a high-pressure mercury lamp. It was obtained by developing with a 0.2% by weight aqueous sodium hydrogen carbonate shower for 30 seconds. Thereby, the pixel layer 11 was formed. Thereafter, the transparent insulating layer 15 was applied by spin coating using an overcoat agent V-259PA manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. as a coating liquid, and dried at 100 ° C. for 5 minutes on a hot plate to dry the coating film. After drying, a high pressure mercury lamp was used as a light source, and the coating film was cured by exposure with a light amount of 100 mJ / cm ² to form.

  Subsequently, on the other main surface of the transparent substrate 10 on which the pixel layer 11 is not formed, ITO is formed as a conductive electrode layer 16 on one side by a sputtering method, and then by photolithography and ferric chloride solution. Etching was performed to form X-pattern electrode shapes arranged in parallel with the X-axis direction of the transparent substrate 10. Next, the electrode wire 17 was formed with a thickness of 2 μm after gravure offset printing of Mino Group MP-704GO, followed by drying at 130 ° C. for 10 minutes.

  Through the above-described materials and processes, the color filter 1, that is, the color filter 1 integrated with the on-cell touch panel was produced. Thereafter, the surface of the pixel layer 11 of the color filter 1 integrated with the on-cell touch panel and the TFT substrate 30 are bonded together with a sealing material, and a liquid crystal material is injected into the gap to form the liquid crystal layer 20. A liquid crystal display 40 having a touch panel function. It was created.

  When the liquid crystal display 40 having a touch panel function was connected to the IC and the touch sensing and the liquid crystal driving were confirmed, it was confirmed that both of them operated well.

  The color filter of the present invention can be used for a liquid crystal display using a touch panel as an input / output device, such as a liquid crystal color television, a liquid crystal notebook personal computer, a mobile phone, a portable information terminal, and a car navigation system.

DESCRIPTION OF SYMBOLS 1 Color filter 10 Transparent base material 11 Pixel layer 12 Nonelectroconductive black matrix 13 Conductive black matrix 14R Red colored part 14G Green colored part 14B Blue colored part 15 Transparent insulating film 16 Conductive electrode layer 16a Conductive electrode 17 Electrode line 20 Liquid crystal layer 30 TFT substrate 40 Liquid crystal display

Claims (9)

A transparent substrate;
A black matrix having conductivity formed on one main surface where the colored portion of the transparent substrate is formed;
A color filter comprising: a conductive electrode formed on the other main surface where the colored portion of the transparent substrate is not formed.   The color filter according to claim 1, wherein the conductive black matrix has a sheet resistance of 270Ω / □ or less.   The color according to claim 1 or 2, wherein the conductive black matrix includes a conductive material made of metal nanowires, metal particles, carbon nanotubes, graphite, a conductive polymer, or a combination thereof. filter.   2. The plurality of black matrices formed in parallel in one direction among the black matrixes having conductivity are electrically connected by a conductive black matrix formed in a direction crossing these. The color filter in any one of -3.   5. The conductive electrode according to claim 1, wherein the conductive electrode includes a conductive material made of any one of ITO, metal mesh, metal nanowire, conductive black matrix resin, or a combination thereof. Color filter.   The color filter according to claim 1, further comprising a touch panel function that senses a touch position by reading a capacitance between the conductive black matrix and the conductive electrode. A color filter according to claim 6;
Liquid crystal,
A liquid crystal display comprising a TFT substrate. A step of laminating a pixel layer on which a conductive black matrix is formed on one main surface of the transparent substrate;
A step of sequentially bonding a liquid crystal and a TFT substrate on the pixel layer;
Forming a conductive electrode on the other main surface of the transparent base material on which the pixel layer is not laminated. A step of laminating a pixel layer on which a conductive black matrix is formed on one main surface of the transparent substrate;
Forming a conductive electrode on the other main surface of the transparent substrate on which the pixel layer is not laminated;
A method of manufacturing a liquid crystal display, comprising: sequentially bonding a liquid crystal and a TFT substrate on the pixel layer.

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