JPS6315204A - Color filter - Google Patents

Abstract

PURPOSE:To prevent a light beam from being condensed and scattered by a colored image, by providing a transparent resin layer in which a difference of a refractive index to the colored image is <=0.005, and smoothness of the surface is within + or -0.5mum, on a substrate on which the colored image has been provided. CONSTITUTION:On a substrate 10, colored images 11a-11c are provided, and on the substrate 10 provided with the colored images 11a-11c, a transparent resin 12 in which a difference of a refractive index to the colored image is <=0.005, and also, smoothness of the surface is within + or -0.5mum is provided. As for a constituting material of the transparent resin layer 12, it is the easiest forming method to use the same vehicle as ink. In this way, it can be prevented that a light beam is condensed and scattered due to the colored image.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a color filter, and more specifically, to a color filter for color separation in an image pickup tube, a solid-state image sensor color facsimile sensor, etc., and a color filter for color separation in a color liquid crystal display device, etc. Related to color filters for color synthesis.

[Conventional technology]

A color filter has a structure in which fine colored pixels of a plurality of colors are sequentially and repeatedly formed on a substrate such as glass, plastic, an image sensor, a thin film transistor, etc., and an S-retaining film is further provided thereon.

Various methods of forming colored pixels have been proposed.

Practical examples include: (1) Photolithography method (using proteins such as gelatin, grue, and casein, water-soluble polymers with dyeing groups introduced into PTA, etc., and photoreactive hardening agents such as ammonium dichromate and diazo compounds). By using, plate making and dyeing process,
A method of sequentially forming colored images. ) (2) Printing method (a method in which a transparent pigment or dye is used, dispersed in a vehicle, and colored pixels are sequentially formed by screen printing, offset printing, flexographic intaglio printing, etc.). ) (31iJ deposition method (Ionized pigment is dispersed in water, voltage is applied to a transparent electrode patterned in advance, the ionized pigment is deposited on the transparent electrode, and this is repeated sequentially to form colored pixels. (4) Vapor deposition method (sublimation pigment, etc. is deposited on the substrate in a high vacuum, lift-off method, etching method, etc.) to sequentially color pixels, or to apply a high refractive index material to a low refractive index material. A method of sequentially obtaining pixels by using a lift-off method or an etching method on a multilayer interference film in which materials are alternately laminated to a predetermined thickness.

[Problem that the invention seeks to solve]

By the way, when colored pixels are formed by photolithography, curing due to photoreaction may be insufficient, or depending on the dyeing conditions, the pixels may swell or even shrink, as shown in Figure 6.
As shown in a+, the surface of the pixel (21) may become matte. In this case, light is scattered on the matte surface, and the spectral characteristics of the pixel (21) are lower than those without matte. However, each purity decreases significantly.

In FIG. 6(a), (1) indicates the substrate.

When viewing pigment particles as described in item (3) above, the surface is matte because the pigment is attached to the transparent electrode, which is also disadvantageous in terms of spectral characteristics. become.

Furthermore, when colored pixels are formed by a printing method as in (2), other problems arise in addition to matting the surface. That is, as shown in FIG. 6(b), the cross-sectional shape of the colored pixel (3) formed by the printing method is generally so-called lens-shaped, with a thinner film at the outer periphery and a thicker film at the center. If parallel light is transmitted in this state, the light will be concentrated and scattered by the colored pixel portions, resulting in uneven brightness and reduced resolution of the display device.

Therefore, the problem to be solved by the present invention is to provide a color filter that prevents light from being focused and scattered by colored images.

[Means for solving problems]

In the present invention, fine colored images of multiple colors are provided on an r substrate, and the difference in refractive index between the colored image and the colored image is 0.
005 or less, and the color filter is provided with a transparent resin layer having a surface smoothness within ±α5 μm. ” is the gist.

Figure $1 shows the color filter of the present invention.

Colored images (11a) (11b) (11c) on substrate aO
The difference in refractive index with the colored images is 0.00 on the substrate αG on which colored images (11a) (11b) (11c) are provided.
5 or less, and a transparent resin layer whose surface smoothness is within α5 μm is provided.

To explain the manufacturing process of the color filter of the present invention step by step, as shown in FIG. 2(a), a first color u! is applied by a printing method onto a predetermined glass substrate αO. iIl! II (11a) is formed. The cross-sectional shape at this time is so-called lens-shaped, with a thin film at the outer periphery and a thick film at the center. This is cured to form the second and third colors, and fJ12 diagram (b) consisting of green and blue colored images (11a) (Nb) (11c)
) color filters are sequentially formed. The surface unevenness at this time is 3 to 4 μm.

Next, as shown in Figure 1, a transparent resin layer is coated. Coating and forming at a thickness of 10 μm and curing. The surface unevenness at this time is 0.
The diameter shall be 1 μm or less.

As for the constituent material of the duct structure resin layer, it is possible to use a material whose refractive index difference from that of the colored image is within o, o o s, and the most economical method of formation is to use the same vehicle as the ink.

Note that the present invention is applicable not only to the case where a colored image is formed by printing, but also to the case where a colored image is formed by a photolithography method.

[For production]

The principle of the color filter of the invention will be briefly explained below.

As shown in Figure 3, when light is incident on the interface between medium xA and medium B, the angle of incidence is θA1, the angle of refraction is θB, the refractive index of medium A is n, the refractive index of medium B is nB, then Snell's law Therefore, nB/nA-mθ), /smθB.

In general, the refractive index of transparent resin is 15 to t6, and the refractive index of air is about to, so in the case of a color filter made by printing, for example, the light path shown in Figure 5 (IL) is used to collect and collect light.
Scatter.

Furthermore, using FIG. 4, colored pixels by the printing method will be explained below.

The colored image produced by the printing method has a lens shape as shown in Figure 4 (a), but this is approximated to a triangle as shown in Figure 4 tb>, and the approximate focal length is calculated.

Now, here, a"5μ" b=10011m 8 colors (2) Assume that the refractive index of the image is -500, semi-linear light passes through the colored image, and the image is formed in air (refractive index 1,000). .

Incident angle θ1+'L718, refraction angle θ2+2,578°
Therefore, the focal length C of this colored image is approximately 6.
It will be 67mm.

Next, consider the same colored image as the previous ffe, and assume that a transparent resin with a refractive index of 1.501 is imaged on this colored image, the incident angle θ is +1,718°, the refraction angle θ2 + 1.72
0' and the focal length aate is approximately 5 shoulders,
Deterioration in image quality due to focusing and divergence of colored images can be almost ignored.

In fact, the refractive index of the ink vehicle alone and the refractive index after dispersing the pigment are approximately equal, θ1=θ2, &+c
−+oeC, * 5 II (e11 diagram (7) j
, 5A--light path is taken, and the effect according to the present invention is fully achieved.

Table 1 lists the refractive index of transparent resins often used in color filters and the like.

Table 1 Refractive Index of Transparent Resin The above color filters and the color filters before coating with pelvic resin were prepared, and using these, a multicolor electro-optical display device using liquid crystal was created.

The color filters mentioned above that do not have the transparent resin on the wall are
Overall, uneven brightness was noticeable, and it was difficult to read type below 5 points. - 10,000, the color filter of the present invention shows no uneven brightness! It was possible to read 1.5 point type.

Using the same principle, it is possible to prevent light scattering at the interface where the surface is matte, such as in colored pixels formed by photolithography, which improves the spectral characteristics.

〔Example〕

Example 1 Soda lime glass with a thickness of 1111 m and an outer diameter of 100 + n
A color filter was formed.

The PB plate was made as follows.

Using a Ps plate LKP-man (Fuji Pharmaceutical) for offset printing, a film pattern of a predetermined pixel shape is exposed to dense N light, and L
It was developed with a KPfIA image solution and dried, and the desired plate was obtained by gumming the ciscoat gum with a gum coder.

The @Giki Pa version was installed on an offset proofing machine C: and printed using red ink and heat cured. For this red ink,
The 2-day plate was shifted by a predetermined pitch, and green ink was used to heat cure the plate. Further, color viewing pixels were formed in the same manner using blue ink to obtain a single layer of color filter in which red, green, and blue were regularly arranged. When I measured the ag thickness at this time, it was 3~
It was 4 μm.

Rosin-modified phenol is placed on top of this color filter layer.
A paste-like transparent material made of linseed η1 was rolled with a roller to obtain a 10 μm thick layer. The surface unevenness at this time is α1
It was less than μ. This was heat cured to obtain the desired color filter.

Before making the color filter, paste transparent rollers, 15251 and t5263. t5261゜15
The refractive index was 261.

Liquid crystal 1: multicolor by using the color filter of the present invention
When the device was mounted on a 9-channel optical display device and evaluated, excellent image quality was obtained.

The composition of each ink is shown in Table 2 below.

Table 2 Ink composition Red ink Green ink Blue ink Paste duct structure Example 2 An infrared-shielding transparent substrate with a thickness of 0.5 I was washed, and a water-soluble photosensitive solution consisting of ammonium chromate with one point of casein was added to it.
After coating to a film thickness of 118P and drying, it was placed in close contact with a predetermined photomask, exposed, and developed with warm water, and this layer to be dyed was dyed with a red dyeing bath to form a red colored layer. Then, after carrying out a prescribed resist dyeing treatment, a water-soluble photosensitive solution was applied to the cloth to a film thickness of 0.8 μm using the same method as above, drying, exposing, developing, and dyeing with a green dyeing bath. A green colored layer having a predetermined pattern is formed, and a second color colored layer is formed.

Furthermore, if a sixth colored stomach dyed layer with a predetermined pattern is formed using a blue dyeing bath using the same method as the method for forming the second colored layer, red, green, and blue dyed layers with a predetermined pattern can be formed. A color separation filter layer consisting of colored layers is obtained.

Thereafter, the casein-ammonium dichromate water-soluble photosensitive solution was applied to one layer of the color separation filter to a film thickness of 15 μm after being dried under a vehicle load, and then exposed to light and cured to form a protective film FjpA.

Before creating a color filter, a C-nicazein-ammonicum chromate film and films dyed red, green, and blue were prepared, and the results were measured using an Apbe refractometer 3L model manufactured by Shimadzu Corporation in the same manner as in Example 1. 1
5401.

t5409. t5410. It was found that the refractive index was t5412.

The composition of the dye bath used above is shown in Table 3.

Table 3 Dyeing bath composition Red dyeing bath Green dyeing bath Blue dyeing bath When the spectral characteristics of the color filter thus formed were measured, the color filter of the present invention had a top filtration rate of RG- Both B increased by 5 to 7%, and color purity improved.

〔Effect of the invention〕

As described in detail above, the color filter of the present invention has the advantage that condensation and scattering of light due to colored images is prevented, and it has excellent spectral characteristics.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the color filter of the present invention, Figure 2 f
an, (b) is a sectional view showing the manufacturing process of the uninvented color filter, 1st! J (a), (1)) is a schematic diagram showing the path of light at the interface between different refractive index media, Figure 4 fa
) is colored by printing! ! Figure 5fa) is a schematic diagram showing the cross-sectional shape of the I image, Figure 4iJf)) is a schematic diagram showing the light path when the cross-sectional shape of the colored image is approximated to a triangle, and Figure 5fa) is the light path of a conventional color filter. Schematic diagram showing the funeral 5
Figure fbl is a schematic diagram showing the light path of the color filter of the present invention, and Figure 6fal and (b) are cross-sectional views of a conventional color filter. 10・・・・・・・・・・・・・・・・・・Substrate 11a, 11t+, 11c・・・・Colored image 12・・・・・・・・・・・・......Transparent Tree B ¥110I Patent Applicant Dainippon Printing Hayashiki Company Agent Patent Attorney Atsumi Konishi Figure 2 (b) 11c 11a llb Figure 3 (a) 3 Figure (b)

Claims (1)

[Claims] Fine colored images of multiple colors are provided on a substrate, and the transparent substrate with the colored image has a difference in refractive index of within 0.005 and the surface smoothness is within ±0.5 μm. Color filter with resin layer