JPH04333801A - Production of color filter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to color filters used in liquid crystal display devices, and more particularly to a method for manufacturing color filters using electrophotography.

0002

2. Description of the Related Art Many methods for manufacturing color filters used in liquid crystal display devices have been proposed, and some of these methods have been put into practical use. For example, by coating a photosensitive resin on a transparent substrate,
There is a method of manufacturing a color filter by forming a desired pattern according to a conventional method, dyeing the pattern red, for example, and forming green/blue in the same manner (this is called a dyeing method). In addition, there is a method in which a photosensitive resin in which pigments or dyes are dispersed in advance is used to form a desired pattern according to a conventional method, and red, green, and blue pixels are sequentially formed (this is the colored resin method). ), a method in which a desired pattern made of a transparent conductive film is formed on a transparent substrate, and then electrodeposited while applying electricity only to the pattern to be colored to form pixels (this is called an electrodeposition method), offset printing, etc. There are printing methods for producing color filters using

Other methods have been proposed, including a method of forming pixels on a substrate by vacuum evaporation, and a method of forming pixels using a silver halide emulsion as in color photography.

[0004] Among the color filter manufacturing methods that have been put to practical use to date, the dyeing method and the colored resin method require a relatively long process for applying a photosensitive liquid and soft baking and hard baking. In the electrodeposition method, a coloring material is electrodeposited by applying electricity to ITO patterned for each color. Therefore, in ITO, patterns of the same color must be connected to each other, which imposes restrictions on pixel shape and arrangement. Further, ITO must not conduct between different colors, and patterning of ITO requires advanced microfabrication technology.

[0005] The printing method does not require so-called photolithography such as applying a photosensitive liquid, exposing, and developing, and the manufacturing process is relatively short. However, the shape and positional accuracy of the pattern must be maintained at a high level, and advanced and special printing technology is required.

Therefore, as a simpler method for manufacturing color filters, a method for manufacturing color filters using an electrophotographic method is disclosed in Japanese Patent Laid-Open Nos. 48-16529 and 5.
This method is disclosed in Japanese Patent Application Laid-Open No. 6-69604, Japanese Patent Application Laid-Open No. 117210-1982, and Japanese Patent Application Laid-Open No. 234203-1983.

[0007]

[Problems to be Solved by the Invention] In manufacturing color filters by electrophotography, a photoconductor layer is charged and then exposed to light through a predetermined mask to remove charges from areas other than the pixel areas and remove static electricity. Since the process of forming and developing an electrostatic latent image is used, the process is simpler than other color filter manufacturing processes.

However, in the electrophotographic color filter, a signal line for driving the liquid crystal panel must be newly provided on the color filter. In order to form a signal line, it is necessary to first provide an insulating overcoat layer on the color filter, then provide a conductive film over the entire surface, and then pattern it to form the signal line.

Furthermore, even if an overcoat layer and a signal line are formed on a color filter, since an electrophotographic color filter has a conductor layer under the photoconductor layer, the overcoat layer is not pinned. If there is a hole, there is a problem in that the signal lines and the conductor layer of the color filter are short-circuited, resulting in a short-circuit between the signal lines.

0010

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and provides a base material for a color filter in which a pixel-shaped conductive pattern and a photoconductor layer are successively laminated on a transparent substrate. A step of charging the photoconductor layer on the conductive pattern of the non-pixel forming area of the color filter base material, a step of leaving an electrostatic latent image on the photoconductor layer, and developing using a toner having a charge of the same polarity as the charge. The above problem has been solved by a method of manufacturing a color filter in which the steps of . . . and . . . attaching toner to the pixel forming portion to form pixels are repeated multiple times.

[0011] After forming the pixels, a step may be added in which development is performed using a black toner having a polarity opposite to that of the charged charges to form a black pattern.

0012

[Operation] The method for manufacturing a color filter according to the present invention is as follows:
Since we use a color filter base material in which a pixel-shaped conductive pattern and a photoconductor layer are sequentially laminated on a transparent substrate, the conductive pattern can be used as a conductor in electrophotography when forming pixels, and also as a liquid crystal. After manufacturing the panel, it can be used as a driving signal line.

The present invention will be explained in detail below. FIG. 1 shows a cross-sectional view of an example of a color filter manufactured by the manufacturing method of the present invention. The transparent substrate 3 is usually made of glass, but any organic or inorganic material can be used as long as it is transparent and can hold each layer. Furthermore, various types of glass such as soda lime glass and silicate borate glass can be used.

A conductive pattern 2 is formed on a transparent substrate 3. The conductive pattern is created using lithographic methods.
A method of patterning a transparent conductive film such as O (indium tin oxide) can be used, but other pattern forming methods may be used as long as they can form a good shape. Furthermore, the material for the conductive pattern is not limited to inorganic materials, but also conductive organic polymers. The conductive pattern 2 extends perpendicularly to the plane of the paper in FIG. Furthermore, since the line will be used as a signal line after manufacturing the liquid crystal panel, it must be continuous and must not be short-circuited with adjacent patterns. Although several patterns can be considered that satisfy these conditions, a striped pattern is convenient for use.

A photoconductor layer 1 is formed on the top surface of the transparent substrate 3. The photoconductive material used for the photoconductor layer is PVK (
Polyvinylcarbazole) etc. can be used. A material in which a conductive pattern is provided on a transparent substrate and a photoconductor layer is further provided is called a color filter substrate.

FIG. 1 shows a case where pixels of red 4, green 5, and blue 6 are formed on a color filter base material.

FIGS. 2(a) to 2(e) are cross-sectional views showing an example of the manufacturing process of the color filter of the present invention.

FIG. 2(a) explains the process of charging the color filter substrate. Using the charger 10, the entire surface of the color filter base material is negatively charged. In addition,
Although the figure shows the case of negative charging, the process is similar even if the battery is positively charged.

FIG. 2(b) explains the process of leaving an electrostatic latent image on the photoconductor layer on the conductive pattern in the non-pixel forming area of the color filter substrate. After charging in the above step, exposure light 8 is irradiated through the mask 7. Exposure is performed so that the portion of the mask through which light passes matches the pixel portion. During exposure, there is a conductive pattern in the lower part of the photoconductor layer 1, and the charge on the exposed part (pixel forming area) decreases, while the non-pixel forming area becomes charged (electrostatic latent image). ) remains.

FIG. 2(c) explains the process of performing development using toner having the same polarity as the charge and depositing the toner on the pixel forming portion to form pixels. After exposure, if development (reversal development) is performed using a toner having the same polarity as the charge, that is, a negative charge, a pixel 4 can be formed in the pixel forming area after development (see FIG. 2(d)). Note that when positive charging is performed in the charging step, development may be performed using a toner having a positive charge in this step.

[0021] By changing the toner color and repeating the same process two more times, a color filter having pixels of three colors of red 4, green 5, and blue 6 can be manufactured (see Fig. 2 (e).
) reference).

Furthermore, in the method of manufacturing a color filter of the present invention, a black pattern for light shielding may be provided as necessary.

After forming each red, green, and blue pixel, it is charged again and exposed so that the black pattern portion becomes a non-exposed portion. The part where the black pattern is formed corresponds to the part where there is no conductive pattern in the color filter base material. Therefore, in this portion, the charge does not drop due to exposure, and a black pattern can be formed by developing with a black toner having a polarity opposite to that of the charge after exposure.

In this series of steps, the conductive pattern is preferably grounded to a common potential.

[0025]

EXAMPLE An example of the present invention will be described in detail.

A film of ITO (indium tin oxide) was formed on a transparent substrate of glass (low expansion glass manufactured by Corning, trade name 7059) by sputtering. The film thickness is approximately 0.
It was 1 μm. Next, a positive photoresist (product name S-1400-27, manufactured by Shipley) is applied, and the parts corresponding to the red, green, and blue pixels of the color filter block light, and these light-blocking parts After exposure using a photomask prepared so that the parts corresponding to the colors were connected to each other, a resist pattern for conductive patterning was obtained by development. The light-shielding portion of this photomask was striped. Next, using the resist pattern as a mask, the ITO film was etched using an etching solution containing hydrochloric acid as a main component, and the photoresist film was removed to form a conductive pattern of ITO.

On the other hand, 100 parts by weight of poly-N-vinylcarbazole (trade name Tubicol 210, manufactured by Anan Perfumery Co., Ltd.);
was dissolved in 900 parts by weight of cyclohexanone to prepare a mother liquor for the photoconductor layer. This mother liquor was applied to a thickness of about 3 μm using a wire coater on the transparent substrate on which the conductive pattern was formed, and dried in an oven at 150°C for 30 minutes.
It was used as a base material for color filters.

After all ends of the conductive pattern are grounded, -6 kV is applied to this color filter base material using a corona charger to cause a negative corona discharge to the photoconductor layer, and the entire surface is charged.

A red pattern mask for color filters is positioned over the conductive pattern over the charged color filter base material, and exposed to light so that the charged potential of the portions that will become pixels is reduced. An electrolatent image was formed.

Next, a red colorant (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name: Spilon Read G) was added to the white latex obtained by the reaction of the cyclized rubber and halogen-containing methacrylate described in JP-A-62-269101.
A red toner liquid, which is a negatively charged liquid toner, is prepared by dispersing RLH) and adding an isoparaffin solvent (trade name: Isopar G, manufactured by Esso Chemical Co., Ltd.), and the color filter substrate is immersed in the red toner liquid for development. As a result, red pixels were well formed.

Next, the color filter base material on which the red pixels have been formed is charged so that an electrostatic latent image with a lower charging potential than other parts is formed in the area adjacent to the red pixel. Exposure was performed by aligning the mask position with the conductive pattern, and development was performed with a green toner liquid to form green pixels. Furthermore, a similar process was performed using a blue toner solution to form blue pixels.

Through the above steps, pixels of three colors, red, green, and blue, could be formed, and a good color filter could be formed.

In the image forming process, the ends of the conductive pattern were constantly grounded to a common potential.

When the color filter manufactured by the above process was incorporated into a simple matrix type liquid crystal display device and the conductive pattern was driven as a signal line, a good image display was achieved.

Note that the photoconductivity of PVK was lowered by heating after forming the color filter. This improves the insulation required for liquid crystal display.

[0036]

Effects of the Invention In the color filter produced by the manufacturing method of the present invention, unlike conventional methods, the conductive film is patterned to form a conductive pattern, and the conductive pattern is used as an electrophotographic conductor when forming pixels. Furthermore, it can now be used as a signal line for driving liquid crystals when creating liquid crystal panels. Therefore, manufacturing is simplified and short circuits between signal lines are eliminated.

[0037]

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a color filter according to the present invention.

FIGS. 2(a) to 2(e) are explanatory diagrams of the method for manufacturing a color filter according to the present invention, in which (a) is a step of charging a color filter base material, and (b) is a color filter manufacturing method; (c) is a step of leaving an electrostatic latent image on the photoconductor layer on the conductive pattern in the non-pixel forming area of the base material; (c) is developing using a toner having the same polarity as the electrostatic charge; a step of attaching toner to form pixels, (d)
(e) shows pixels after development, and (e) shows a color filter having three color pixels.

[Explanation of symbols]

1 Photoconductor layer 2 Conductive pattern 3 Transparent substrate 4 Red pixel 5 Green pixel 6 Blue pixels 7 Mask 8. Light for exposure 9 Toner 10 Charger

Claims (2)

[Claims] 1. A method for manufacturing a color filter using a color filter base material in which a pixel-shaped conductive pattern and a photoconductor layer are sequentially laminated on a transparent substrate, the method comprising: (a) a color filter base material; a step of charging the material, (b) a step of leaving an electrostatic latent image on the photoconductor layer on the conductive pattern in the non-pixel forming area of the color filter base material, and (c) a charge of the same polarity as the charging. Performing development using a toner having
A method for producing a color filter, comprising repeating the steps (a) to (c) described above, a step of depositing toner on a pixel forming portion to form pixels, a plurality of times. 2. The method of manufacturing a color filter according to claim 1, further comprising the step of performing development using a black toner having a polarity opposite to that of the charged charges after forming the pixels to form a black pattern.