JPH02204723A - Production of electrode for liquid crystal cell with color filter - Google Patents

Abstract

PURPOSE:To obtain the electrode for a liquid crystal cell with color filters having high performance with good productivity at a low cost by forming the electrodes of the same pattern on both surfaces of a plastic film substrate so as to be superposed on the front and rear surfaces and forming colored layers on one surface thereof. CONSTITUTION:Transparent conductive films 2 consisting of ITO films are formed on both surfaces of the film 1 and the same patterns 3 are formed on both surfaces thereof so as to be accurately superposed on each other. The colored layers 4 of red, blue and green are then successively formed by an electrodeposition method with the patterns 3 on one surface as electrodes and the gaps between the colored layers are filled with a black pigment to form a black matrix 5. A top coating layer may be further applied in order to protect the colored layers. The electrodes on the surface opposite to the colored layers of the resulted color filters are used as the electrodes for the liquid crystals and are intersected orthogonally with the striped electrodes which are separately provided, by which the liquid crystal cell made by using a TN liquid crystal is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrode for a liquid crystal cell with a color filter used for colorizing liquid crystal display devices and the like.

[Conventional technology]

Color filter manufacturing methods include a dispersion method, a dyeing method, a printing method, and an electrodeposition method, and the present invention relates to an electrodeposition method.

The following process is used to produce an electrode for a liquid crystal cell with a color filter using the electrodeposition method.

First, an ITO film, which is a transparent electrode, is formed on a film or glass, and a button is formed by photo-etching.Next, according to this button, red, green, and blue are sequentially colored.Next, a black mask is applied between the colored layers. Fill in the color, eliminate the difference in level caused by the colored layer, smooth it, and on top of this,
When ITOIII is formed and the electrode used for the coloring layer is used as it is as the electrode of the liquid crystal cell,
A voltage drop occurs across the colored layer, reducing the voltage applied to the liquid crystal. As a result, the duty ratio is small, that is,
In a cell with a large number of electrodes, crosstalk occurs, contrast decreases, and good image quality cannot be obtained.Therefore, it is necessary to form ITO electrodes in direct contact with the liquid crystal in addition to coloring.

[Problem to be solved by the invention]

Among the various methods for producing color filters, the electrodeposition method is most suitable for forming large-area color filters on plastic films because it allows the production of large-area color filters with high precision.

However, in order to produce an electrode for a liquid crystal cell with a color filter using the electrodeposition method, an ITO film electrode must be formed twice: once for electrodeposition and once for liquid crystal, which causes several problems.

First, the spaces between each colored layer are filled with a black mask, smoothed, and then top coated, etc. However, since it is not completely flat, the yield of the second liquid crystal electrode is poor.
Next, the electrodes for the liquid crystal, which will be formed later, are on top of the colored layer and are affected by the dielectric multilayer materials such as the substrate film, the colored layer, and the coating layer, so they are unstable and unreliable. becomes a problem.

Furthermore, in the electrodeposition processing process, it is currently difficult to perform continuous processing using hoop materials. Therefore, it is difficult to continuously form the 2nd t=th ITO, and the ITO film must be applied in a batch manner, resulting in production sexuality is severely impaired.

The present invention solves this important problem and provides an electrode for a liquid crystal cell equipped with a color filter, which has a good productivity of tJ and has high performance.

[Means to solve the problem]

The present invention solves the above-mentioned problems, and is a method for manufacturing an electrode for a liquid crystal cell with a color filter using a plastic film as a substrate using an electrodeposition method. formed into;
This is a method for manufacturing an electrode for a liquid crystal cell with a color filter, which is characterized by forming a colored layer on one side of the electrode.

To explain with drawings, a transparent conductive film (2) such as an ITO film is formed on both sides of a film (1), the same battens (3) are formed on both sides in the form of oaks that overlap with precision, and the battens (3) on one side are formed on both sides.
) are used as electrodes to sequentially form red, blue, and green colored layers (4). The gap between the zero-order colored layers is filled with black pigment to form a black mask (5). Furthermore, a top coat layer may be coated on top of this as a protective layer.

If the electrode on the surface opposite to the colored layer of the color filter thus obtained is used as an electrode for liquid crystal, the conventional problems can be solved.

[For production]

In the present invention, since the electrodes of the liquid crystal cell and the color filter are separated on both sides of the film substrate, the liquid crystal cell and the color filter are separated by the thickness of the film, causing misalignment when viewed from an angle.

Therefore, it is desirable that the dots for display are not too detailed.

For example, it is desirable that the size of the dot is greater than or equal to the thickness of the film. In other words, if the thickness of the film is 100 μm, the dot size is preferably 100 μm x 100 μm or more. The design of these values is based on the field of view of the finished liquid crystal cell. It is determined by the angle, purpose, etc.

Due to these limitations, it can be said that the present invention is suitable for liquid crystal display elements that are viewed from a distance of 50 C1 or less.

For the reasons mentioned above, the thinner the film, the better.
From the viewpoint of handling, the thicker the better, from 30 μm to 3
00 μm is preferable, and the film used is:
Examples include films that are transparent, have good optical properties, and are heat resistant, such as polyether sulfone, polyester, polycarbonate, and polyarylate.

Next, as a method for forming transparent electrodes on both sides of the film, a transparent conductive film of an oxide such as ITO, SnO, or InO is formed on both sides by a physical method, and both sides or one side are protected by photoetching. There is a way to process one side at a time.

The overlapping color layer forming method used in the present invention is a general electrodeposition method, in which a pigment is used as a coloring agent, and an anionic or cationic resin system is used as a binder.The colored layer has wavelength characteristics. It is desirable that the color be as sharp as possible, and that the colored layer itself has a light transmittance of 80% or more at the wavelength of the color.

The electrode for a liquid crystal cell with a color filter of the present invention includes:
In some cases, it is processed to a state where an alignment film for liquid crystal is coated, and in this case, a high tilt alignment film for TN liquid crystal or STN liquid crystal is used. As a material for the alignment film, a vapor-deposited film of an organic material such as polyimide or an inorganic material such as Stow is used.

[Example 1] Approximately 5ooX of ITO was sputtered on both sides of a 100 μmH polyether sulfone film, and the sheet resistance was approximately 1.
Striped battens for zero-order color filters and liquid crystal cells (40 units with 500 μm gap in the middle, 50 m square) on which a transparent conductive film of 50 Ω/hole was formed were formed on both sides. In this case, colored layers of red, green, and blue were formed by electrodeposition on one side of the zero-order processed substrate, which was simultaneously processed on both sides by projection exposure, and the spaces between them were filled with a black mask. The black used was a resin containing a black pigment, and a top coat was applied to protect the zero-order colored layer. Using the electrode on the back side of the color filter obtained in this way and the stripe electrode provided elsewhere, we made a liquid crystal cell using TN liquid crystal by orthogonally crossing them. When I drove it using an EL clamp and tried it as a transmission type, there was no drop in the voltage applied to the liquid crystal, so a fairly good contrast was obtained at a duty ratio of 1/90, and the color tone was sufficient for practical use. .

The above method is sufficiently mass-producible and is a technology that can be used in engineering.

[Example 2] I was coated on both sides of a 1001 m thick polyester film.
TO is sputtered to a thickness of 30OA, and the sheet resistance is 30
0 people Seven transparent conductive films were formed.

Colored layers are formed on both sides of this substrate with a gap of 800μ in the circuit, and the space between the colored layers is filled with black to serve as a color filter, and the circuit on the back side is used as an electrode for a liquid crystal cell.
An I-angle colored film liquid crystal cell was produced.

This time, since the area was larger, the density of the gap material was slightly larger, but the manufacturing method of the cell was the same as in Example 1. When this cell was turned on as an EL clamp backlight, the contrast was Both the color tone and the color tone were sufficiently usable for practical use.

〔effect〕

When producing color filters by electrodeposition, an ITO electrode must be formed on the colored layer in order to make the electrodes for the liquid crystal cell adhere to the colored layer, but problems such as flatness of the colored layer and coloring occur. In the case of plastic film substrates, the problem of reliability of the electrodes on the layer and the productivity of the ITO electrodes on the colored layer become particularly serious problems.

However, if the liquid crystal electrode is formed on the back side of the colored layer as in the present invention, there will be some restrictions on the application, but the above problems will be solved. It becomes possible to manufacture electrodes for liquid crystal cells with color filters using plastic film as a substrate.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an electrode for a liquid crystal cell, etc., showing the process order of the present invention.

Claims (1)

[Claims] (1) In a method of manufacturing electrodes for liquid crystal cells with color filters using a plastic film as a substrate by electrodeposition, the same pattern is formed on both sides of the film substrate so that the front and back sides overlap, and a colored layer is applied on one side. A method for manufacturing an electrode for a liquid crystal cell with a color filter, characterized by forming an electrode for a liquid crystal cell with a color filter.