JP2819245B2 - How to fix color filters - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method formed by a printing method.
For more information on how to correct color filters, see
Color liquid crystal display device, color facsimile, EL, PD
The present invention relates to a method for correcting a color filter formed by a printing method used for displays such as P. 2. Description of the Related Art A color filter for a color liquid crystal display device is formed by repeatedly forming fine colored pixels of a plurality of colors repeatedly on a substrate such as glass, plastic, or a thin film transistor, and further forming a protective film thereon. The following various methods have been proposed for forming colored pixels of the color filter. (1) Photolithography method Proteins such as gelatin, glue, casein, and PVA
A method in which colored pixels are sequentially formed by a plate-making and dyeing process using a water-soluble polymer having a dye group introduced therein and a photoreactive curing agent such as ammonium dichromate and a diazo compound. (2) Electrodeposition method The ionized pigment is dispersed in water, a voltage is applied to a pre-patterned transparent electrode, and the ionized pigment is deposited on the transparent electrode. How to get. (3) Evaporation method Sublimation dyes and pigments are applied on a substrate in a high vacuum, and colored pixels are sequentially obtained by a lift-off method, an etching method, or the like, or a low-refractive-index substance and a high-refractive-index substance are applied to a predetermined film. A method of sequentially obtaining colored pixels by a lift-off method or an etching method of a multilayer interference thin film laminated alternately in thickness. (4) Printing method A method in which pigments or dyes having good transparency are dispersed in a vehicle, and each colored pixel is sequentially formed by a screen printing method, an offset printing method, or a flexographic intaglio printing method. In particular, the printing method of (4) has the characteristics that the cost can be reduced because the productivity is very excellent, and further, the physical properties of the colored pixels are robust. It was a drawback in the past,
Accuracy aspects such as pixel dimensions and total pitch have also been improved, and are now at a level where they can be sufficiently used for color filters. [0004] The printing method has the above advantages, but has the disadvantage that pinholes often occur in colored pixels. For example, offset printing
Adhesion of ink to plate, blanket, substrate, water, etc.
Because the balance is established based on the balance by physical factors such as contact angle, viscosity, tack value, and thixotropy, these balances are locally lost by dust, unpurified components of ink, water, solvent, etc. Pinholes occur. For this reason, careful attention was paid to the ink refining method and the color filter production environment.
Efforts have been made to reprint and minimize pinholes. In the case of a color filter for a color liquid crystal display device, the purpose is to improve color purity and contrast, and in a color liquid crystal display device using a thin film transistor system, to prevent dark current due to light from the transistor. Attempts have been made to provide a black light-shielding portion between colored pixels. Although it is possible to provide these black light-shielding portions by combining lines having a width of several tens of μm by a printing method, there are the following problems. First, it is necessary to prepare a plate for a black light-shielding portion in addition to a plate for a colored pixel, and there is a problem that it is difficult for the two to register in the XY-θ direction. Also, there is a problem that an aperture ratio of the color filter is reduced because an overlap portion is formed between the colored pixel portion and the black light shielding portion. Due to the above-described problems, the formation of the black light-shielding layer by the conventional printing method has not been able to provide a sufficient effect at a rate requiring much time and effort. Therefore, the problem to be solved by the present invention is to solve the drawbacks of the color filter by the conventional printing method, and to easily provide the color filter in which the substrate surface area other than the colored pixels is shielded by the black light shielding portion. It is an object of the present invention to provide a method for modifying a color filter that can be manufactured. Means of the present invention is to provide a colored pixel in a color filter in which a plurality of colored pixels are formed on a transparent substrate by a printing method at a predetermined pitch and sequentially and repeatedly. Is a method of correcting the pinholes of the above. When the vehicle of the colored pixel is oily, the black colored negative photosensitive resin is used on the entire surface of the transparent substrate on which the colored pixel is provided, and the vehicle of the colored pixel is soluble in water. In this case, apply a water-soluble black-colored negative-type photosensitive resin, expose it from the side opposite to the side where the colored pixels are provided, and develop it to fill the pinhole with black-colored negative-type photosensitive resin And a method of correcting a color filter. Hereinafter, each component of the present invention will be described in detail with reference to the drawings. FIGS. 1 (a) and 1 (b) show the present invention, respectively.
FIGS. 2A and 2B show a top view and a cross-sectional view of a color filter to be corrected in FIGS. The color filters formed by the printing method are sequentially arranged like the colored pixels 3, but the bright and white backlight light leaks due to the pinholes (or chips) 1, so that the overall color purity is reduced. In addition, since the pinholes 1 scattered irregularly are almost transparent, the brightness is
There are about 3-5 times of red and blue colored pixels, about 2-3 times of green,
In the case of pixel display, the stars just appear to shine and the display quality is remarkably reduced. In the present invention, these portions are filled with a black material, and these are optically shielded. Further, the gap 2 between the colored pixels 3 is filled with a black material for the same purpose. As the black material, a material obtained by preliminarily dispersing carbon or the like in a resin and curing the same can be used.
You . The above color filter can be obtained by the following manufacturing method. First, the color filter of the present invention is used.
The method of correcting the luter will be described with reference to FIGS. Colored pixels 5 are sequentially formed on a transparent substrate 6 such as glass or plastic by an offset printing method or a silk screen printing method. Next, a negative photosensitive resin 7 in which a black dye and a pigment are dispersed is applied. The selection of the negative photosensitive resin depends on the vehicle of the colored pixel 5 obtained by the printing method, and is determined in consideration of the wettability to the colored pixel 5. That is, when the vehicle of the colored pixel 5 is oily, the negative photosensitive resin also uses oily,
If the vehicle is water-soluble, apply a water-soluble photosensitive resin. However, even if the vehicle is a water-soluble resin, if the hydrophilic group is lost due to a dehydration reaction or the like during curing, an oil-based photosensitive resin is preferred. When a negative photosensitive resin capable of satisfying the above conditions is oily, E.C. Kodak KPR, KO
R, KAR-3, KMER, KMR series, Dyna
Chem DCR, Hunt Chem Way CO
AT series, Fuji Pharma FSR, FPER series,
FVR, Tokyo Ohkasha EPPR, OMR series, OS
R, OTER, ONNR series, TPR, Toray Photo Nice UR-3000, Nippon Synthetic Rubber CIR-77
1, CBR-M or various UV curable resins are used. For water-based, Morohishi Ink MR-S, Fuji Pharmaceutical FVR, FR Series, Tokyo Oka G-90, NONC
RON, Noland NPR-29, Ueno Chemical COM
SIST and the like. Since these photosensitive resins are used for forming a light-shielding layer, they are not necessarily required to be colorless and transparent, and are selected according to adhesion, sensitivity, and resolution. The black material is dissolved or uniformly dispersed in the photosensitive resin. In the pigment system, carbon black (CI. 77265) and acetylene black (C.I.
I. 77266), lamp black (CI. 7726)
6), bone black (CI. 77267), graphite (CI. 77265), iron black (CI. 7949)
9), aniline black (C.I. 50440), cyanine black, and dyes. In the case of uniformly dispersing in the same manner as the pigment, any black coloring dye may be used. When using a direct dye, C.I. I. Direct Black 17 (C.I.
I. 27700), C.I. I. Direct Black
19 (CI. 35255), C.I. I. Direct
Black 22 (CI. 35435), C.I. I.
Direct Black 32 (CI. 3544)
0), C.I. I. Direct Black 38 (C.I.
I. 30235), C.I. I. Direct Black
(CI. 27720), C.I. I. Direct Bl
ack 56 (C.I. 34170), C.I. I. Dir
ectBlack 71 (CI. 25040), C.I.
I. Direct Black 74 (CI. 3418)
0), C.I. I. Direct Black 75 (C.I.
I. 35870), C.I. I. Direct Black
77 (CI. 35860) and the like, and oil-soluble photosensitive resins include oil-soluble dyes, specifically, C.I. I. Solven
t Black 3 (CI. 26150), C.I. I.
SolventBlack 5 (CI. 5041)
5), C.I. I. Solvent Black 7 (C.I.
I. 50415), C.I. I. Acid Black 1
23 (Solvent Black) (CI. 121)
95) etc. are used. It is necessary to carefully select these black materials in order to maintain the presence or absence of reaction with the photosensitive resin, sufficient sensitivity and resolution, adhesion to the substrate, and coatability. Also, the black material does not need to be single black, for example, red,
It can also be obtained by mixing colors with blue and green materials. A substrate 6 coated with a black photosensitive resin 7;
As shown in FIG. 2 (c), U
V irradiation is performed. At this time, if the amount of exposure is excessive, the colored pixels 5 are also exposed, so that it is important to determine the optimum amount of exposure. Photosensitive resin portion corresponding to the pin holes of Richaku color pixel by the exposure is made to light-sensitive. Further, FIG.
The color filter is corrected by developing with a specified developer as described in Immersion method, spray method, etc.
Can be . EXAMPLES ( Examples ) Preparation of Colored Pixels Corning Co., Ltd. 5 inch □ 7059 material (1.1 mm thick)
t) was ultrasonically cleaned using a 1% RBS cleaning solution manufactured by Wako Pure Chemical Industries, washed with water, dried, and then subjected to offset printing to obtain colored pixels. The plate used for printing was Toraysha, a waterless planographic plate.
The mosaic pattern was printed on the original plate by exposure and developed by the company's dedicated developing machine TWL-650. This was mounted on an Ecta printing machine (offset proofing machine) of Red Sheep Co., Ltd., printed with red ink, and thermally cured. The plate was shifted by a predetermined pitch with respect to the red ink, and was thermally cured using a green ink. Further, colored pixels were similarly formed using blue ink to obtain colored pixels in which red, green, and blue were regularly arranged. Table 1 shows the composition of each ink. [Table 1] Preparation of light-shielding portion, etc. A black colored negative photosensitive resin in which 5% by weight of Daido Kasei Co., Ltd. diamond black (CI. 50440) is dispersed in 30 cp of OMR-85 Tokyo Oka Co., Ltd. Spin coating to 0.5μm, 90 ° C, 30
Prebaking was performed in a clean oven for minutes. Subsequently, only the ultraviolet light of a 2 kW mercury lamp is irradiated from the back side of the colored pixel pattern surface for 60 seconds through a 300-400 nm transmission type color filter manufactured by Toshiba, spray-developed with a dedicated developer for 1 minute, and then rinsed with a dedicated rinse solution. And baked in a clean oven at 150 ° C. for 30 minutes. Finally, a silicone resin SR2406 manufactured by Torre Silicone Co., Ltd. was spin-coated at a film thickness of 1 μm, and thermally cured in a clean oven at 1500 ° C. for 30 minutes to obtain a desired color filter. The color filter obtained in this manner had no pinholes and had a flatness of 0.2 μm in a range, which was extremely excellent in characteristics. According to the color filter obtained by the method for correcting a color filter of the present invention, the pinhole is shielded by the black light-shielding portion, so that a display with excellent image quality can be displayed. Since the substrate area other than the colored pixels is shielded from light by the black light-shielding part, color purity and contrast
Etc. can be displayed. In addition, since the flatness is excellent, there is no variation in the distance between the electrodes, and thus a uniform display can be performed. Further, according to the modification <br/> method of the present invention, by a simple process, a pinhole-free Ku
Since it is Succoth, image quality good, and no aperture ratio decreases by the light shielding portion, it is possible to obtain a color filter flatness have good properties.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a top view and a cross-sectional view of a color filter modified by the present invention. FIG. 2 is a cross-sectional view illustrating a process of a method for correcting a color filter according to the present invention. FIG. 3 is a cross-sectional view illustrating steps of a method for manufacturing a color filter . FIG. 4 is a cross-sectional view illustrating steps of another method for manufacturing a color filter . [Description of Signs] 1 Pinhole (or chipped) 2 Gap between colored pixels 3 Colored pixels 5, 8, 12 Colored pixels 4, 6, 9, 13 Transparent substrate 7, 10 Negative photosensitive resin 14 Positive photosensitive resin 16 Shading layer

Claims (1)

(57) [Claims] A method of correcting pinholes of a colored pixel in a color filter having a plurality of colored pixels formed in a predetermined pitch and in a repeating arrangement on a transparent substrate by a printing method, wherein the transparent substrate provided with the colored pixels is provided. If the vehicle of the colored pixel is oily, apply an oil-based black-colored negative photosensitive resin on the entire upper surface. If the vehicle of the colored pixel is water-soluble, apply a water-soluble black-colored negative-type photosensitive resin and color. A method for repairing a color filter, characterized in that a pinhole is filled with a black-colored negative photosensitive resin after exposure from the side opposite to the side where pixels are provided and development.