JP2003294933A - Color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter wherein voltage descent due to colored parts is suppressed and control for driving a display material is made easy, in the color filter used for a display device using the display material driven by voltage and having the colored parts on a transparent electrode formed on an insulating transparent substrate. <P>SOLUTION: In the color filter having a plurality of the colored parts 5 on the transparent electrode 2 formed on the insulating transparent substrate 1, a transparent conductive layer 3 is provided between and on a plurality of the colored parts 5, or a conductive black matrix layer 4 is provided between a plurality of the colored parts and the transparent conductive layer is provided on a plurality of the colored parts and the conductive black matrix layer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter, and in particular, when used in a display device, it suppresses a voltage drop due to a coloring portion and facilitates control of driving of a display material. Regarding

[0002]

2. Description of the Related Art With the recent increase in demand for portable information devices, there has been a demand for lighter and thinner display devices. As a result, a color filter using a plastic film as a base material is receiving attention. From the viewpoint of manufacturing efficiency, transparent electrodes,
It is desirable that both the colored portions are continuously formed on a long film, but the single-wafer method can easily obtain a highly fine colored portion. Therefore, a color filter using a plastic film as a base material is first formed into a long film on which a transparent electrode that does not require patterning is formed, and then cut into a panel size of a display device, and a colored portion is separated on the transparent electrode. Often formed by a method.

[0003]

Liquid crystal or electrophoretic display using a color filter having a colored portion provided on a transparent electrode formed on an insulating transparent base material and a back plate having an electrode provided on the base material. In a display device configured by sandwiching a voltage-driven display material such as a material, when a voltage is applied between the electrodes on both base materials, a voltage drop occurs due to the insulating colored portion, so that the voltage is applied to the display material. The voltage is reduced. Furthermore, since the insulating colored portion has a large dielectric constant and causes polarization when a voltage is applied, it becomes difficult to control the driving of the display material. The present invention, in a color filter having a colored portion on a transparent electrode formed on an insulating transparent substrate, which is used in a display device using a display material driven by voltage, suppresses a voltage drop due to the colored portion. It is an object of the present invention to provide a color filter which facilitates control of driving of the display material.

[0004]

The present invention provides a color filter having a plurality of colored portions on a transparent electrode formed on an insulative transparent base material, in a space between the plurality of colored portions and on the plurality of colored portions. The color filter is characterized in that a transparent conductive layer is provided on the.

Further, the present invention is the color filter according to the above invention, characterized in that the insulating transparent substrate is an insulating transparent substrate made of plastic.

Further, the present invention provides a color filter having a plurality of colored portions on a transparent electrode formed on an insulating transparent substrate, wherein a conductive black matrix layer is provided between the plurality of colored portions, and It is a color filter characterized in that a transparent conductive layer is provided on a plurality of colored portions and on the conductive black matrix layer.

The present invention is also the color filter according to the above-mentioned invention, wherein the insulating transparent base material is an insulating transparent base material made of plastic.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the color filter according to the present invention will be specifically described below. FIG. 1 is an explanatory view showing a cross section of a portion of an embodiment of a color filter according to the present invention. As shown in FIG. 1, this color filter comprises a transparent electrode (2) on an insulating transparent substrate (1), a plurality of colored portions (5), a space between the plurality of colored portions (5), and a plurality of the colored portions. The transparent conductive layer (3) is provided on the part (5). The plurality of colored portions (5) are composed of a red colored portion (R), a green colored portion (G), and a blue colored portion (B).

In advance, a transparent electrode having a thickness of 100 n
m indium tin oxide (ITO) film, thickness 1
A 00 μm polyethylene terephthalate (PET) film substrate was taped onto a 1.1 mm thick glass plate. Next, red, green, and blue stripe patterns having a thickness of 1.5 μm and a width of 100 μm were sequentially formed on the indium tin oxide (ITO) surface by photolithography. At this time, a gap of 5 μm was provided between each colored stripe pattern (each colored portion).

Subsequently, a dispersion of indium tin oxide (ITO) in isopropyl alcohol (IPA) (manufactured by Mitsubishi Materials Corp., (NV = 15) is formed on a film substrate provided with each colored stripe pattern (each colored portion). %)), Pentaerythritol acrylate (PETA), and a polymerization initiator Irg184 in a solid content weight ratio of [8: 2: 0.
1] was mixed and made into a coating material, and then applied by spin coating. The coating film was applied so that the film thickness before drying was 1 μm, dried at 70 ° C. for 1 minute, and then cured by ultraviolet rays to form a transparent conductive layer, thereby obtaining a color filter as shown in FIG.

The transparent conductive layer had a sufficient transmittance of 90% or more and a surface resistivity of 10E7Ω / □. When an electrophoretic display device was manufactured using this color filter, a colored stripe pattern (colored portion)
It was confirmed that the voltage drop due to was significantly reduced.

[0012]

Example 1 A 100 μm-thick polyethylene terephthalate (P) layer having a thickness of 100 nm formed of indium tin oxide (ITO) as a transparent electrode in advance.
The ET) film substrate was taped onto a 1.1 mm thick glass plate. Next, the carbon black powder (average particle size 80 nm) and the acrylic resin were mixed in a solid content weight ratio [1:
1] is applied by spin coating to a coating film thickness of 1 μm, dried, and then a photolithography method is used to form a stripe-shaped conductive black matrix with a width of 20 μm at intervals of 100 μm. Layers were formed.

Next, between the black matrix layer on the indium tin oxide (ITO) surface, a red and green layer having a thickness of 1.5 μm and a width of 100 μm was formed by photolithography.
And a blue stripe pattern were sequentially formed. Subsequently, an isopropyl alcohol (IPA) dispersion of indium tin oxide (ITO) (manufactured by Mitsubishi Materials Corp., (NV = 15%)) was formed on the film substrate provided with each colored stripe pattern (colored portion). Pentaerythritol acrylate (PETA) and polymerization initiator Irg1
84 was mixed in a solid content weight ratio of [8: 2: 0.1] to form a paint, which was applied by a spin coating method.

The coating film is applied so as to have a thickness of 1 μm before drying, dried at 70 ° C. for 1 minute, and then cured with ultraviolet rays to form a transparent conductive layer to obtain a color filter as shown in FIG. It was

Next, the adjustment of the microcapsules used as the contrast medium will be described. As the microcapsules, known ones for electrophoretic display in which charged particles cause a contrast change in a viewer by an electric field are used. That is, the white particles are titanium oxide in the polyamide resin,
Black particles are carbon black in polystyrene resin,
The particles were dispersed and fixed to obtain charged particles having an average particle size of 7 μm.

Next, charged particles produced by the above method were added to 100 cc of a 1: 1 aqueous solution of an aliphatic hydrocarbon solvent as a liquid dispersion medium and an aqueous solution of a partial sodium salt of 5% polystyrene sulfonic acid as an emulsifier. The mixture was stirred with a homogenizer at 6000 rpm for 5 minutes to obtain an emulsion in which a liquid dispersion medium containing white charged particles and black charged particles was uniformly dispersed in an aqueous solution.

Separately, a commercially available melamine powder was added to a 37% aqueous formaldehyde solution, adjusted to pH 9.0 with a sodium hydroxide solution, and heated at a water temperature of 60 ° C. for 30 minutes to obtain a melamine / formaldehyde prepolymer. Next, the melamine / formaldehyde prepolymer is added to the above emulsion, and the mixture is mixed with an Ajihomo mixer to obtain 10
While stirring at 0 to 300 revolutions, the water temperature was maintained at 80 ° C. for 5 hours while being heated, then adjusted to pH 7 and cooled to room temperature.

As a result, a wall member made of a melamine / formaldehyde resin is deposited around a liquid dispersion medium containing white charged particles and black charged particles, and the charged particles are encapsulated in the microcapsules (6 to 6) having an average particle diameter of 40 to 70 μm. )was gotten.

A mixture of the thus obtained microcapsules (6) dispersed in a binder (7) made of a urethane resin was coated on the transparent conductive layer (3) and dried. The microcapsule application surface of the color filter including the microcapsules (6) thus formed is provided on the glass substrate (8) with the pixel electrode (9) made of ITO in advance, a thin film transistor (not shown), a signal electrode, and a scanning electrode. The electrophoretic display panel (10) shown in FIG. 3 was formed by sticking it to the surface on which was formed.

According to the electrophoretic display panel (10) thus obtained, it was confirmed that the voltage drop due to the colored stripe pattern (colored portion) was significantly reduced.

[0021]

According to the present invention, in a color filter having a plurality of colored portions on a transparent electrode formed on an insulating transparent substrate, a transparent conductive layer is provided between the plurality of colored portions and on the plurality of colored portions. Since the color filter is a color filter, when used in a display device using a display material driven by a voltage, the color filter can suppress a voltage drop due to a coloring portion and can easily control driving of the display material.

Further, according to the present invention, in a color filter having a plurality of colored portions on a transparent electrode formed on an insulating transparent substrate, a conductive black matrix layer is provided between the plurality of colored portions, and further a plurality of colored black matrix layers are provided. Since it is a color filter provided with a transparent conductive layer on the colored portion and the conductive black matrix layer, when used in a display device using a display material driven by voltage, to suppress the voltage drop due to the colored portion, In addition, the color filter has a black matrix layer that facilitates control of driving of the display material.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a cross section of a portion of an embodiment of a color filter according to the present invention.

FIG. 2 is an explanatory view showing a section of a color filter in Example 1 in section.

FIG. 3 is an explanatory diagram showing a cross section of the electrophoretic display panel according to the first embodiment.

[Explanation of symbols] 1 ... Insulating transparent base material 2 ... Transparent electrode 3 ... Transparent conductive layer 4 ... Conductive black matrix layer 5 ... Coloring part 6 ... Microcapsules 7 ... Binder 8 ... Glass substrate 9 ... Pixel electrode 10 ... Electrophoretic display panel R: Red colored part G: Green colored part B: Blue colored part

Claims (4)

[Claims] 1. A color filter having a plurality of colored portions on a transparent electrode formed on an insulating transparent substrate, wherein a transparent conductive layer is provided between the plurality of colored portions and on the plurality of colored portions. Is a color filter. 2. The insulating transparent base material is an insulating transparent base material made of plastic.
Color filter as described. 3. A color filter having a plurality of colored portions on a transparent electrode formed on an insulating transparent substrate, wherein a conductive black matrix layer is provided between the plurality of colored portions.
A color filter, further comprising a transparent conductive layer provided on the plurality of colored portions and on the conductive black matrix layer. 4. The insulative transparent substrate is an insulative transparent substrate made of plastic.
Color filter as described.