JP4724892B2 - Color filter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color filter, and more particularly to a color filter capable of manufacturing a large-area color liquid crystal display device excellent in display quality.
[0002]
[Prior art]
Conventionally, a monochrome or color liquid crystal display (LCD) has been used as a flat display. Color liquid crystal display devices include an active matrix system and a simple matrix system for controlling the three primary colors, and color filters are used in both systems. In the liquid crystal display device, the constituent pixels are composed of three primary colors (R, G, B), and color display is performed by controlling the transmission of each light of the three primary colors by electrical switching of the liquid crystal.
[0003]
This color filter includes, for example, R, G, and B primary color layers arranged in a predetermined pattern on a glass substrate, and a black matrix positioned at the boundary between the color layers. Such a color filter is a dyeing method in which a dyeing base material is applied on a glass substrate, and a pattern formed by exposure and development through a photomask is dyed. A coloring pigment is dispersed in advance in a photosensitive resist. A pigment dispersion method that exposes and develops through a photomask, a printing method that prints each color with printing ink, and a colored layer of each color is formed by electrodeposition using a transparent electrode patterned on a glass substrate It can be formed by an electrodeposition method or the like.
[0004]
On the other hand, a glass substrate used in the manufacture of a color filter has been shifted to a substrate having a larger area due to a recent demand for a larger display screen. However, with the increase in the area of glass substrates, it is necessary to increase the size of photomasks and exposure equipment used in the manufacturing process, and there are limits to increasing the area of glass substrates to accommodate the increase in the size of display screens. Yes.
[0005]
To solve this problem, use a photomask or exposure device that is smaller than the substrate area from the conventional method of forming a color filter using a large photomask or exposure device that corresponds to the area of the substrate. Then, a method for forming a color filter of a large area by forming a black matrix or a pattern of a colored layer on a substrate to be connected has begun to be studied.
[0006]
[Problems to be solved by the invention]
FIG. 5 is a partial plan view showing an example of the color filter as described above. In the example shown in FIG. 5, the color filter 101 is configured by repeatedly arranging colored layers 105R, 105G, and 105B of three primary colors of R, G, and B on a glass substrate 102 at equal intervals (W ₁ ). A black matrix 103 is provided at the boundary portion. A color filter 101A formed on the glass substrate 102 so as to connect the black matrix and the coloring layer pattern at the connecting portion J by setting the connecting portion J (indicated by a chain line) in one black matrix 103. , 101B constitute a color filter 101.
[0007]
However, in the color filter 101 described above, the spacing W ₁ between the colored layers (the line width W ₁ of the black matrix 103 interposed between the colored layers) and the spacing W between the colored layers at the joint J of the color filters 101A and 101B. ₂ It is difficult in terms of mechanical accuracy to completely match (the line width W ₂ of the black matrix 103 in which the joint portion J is set), and a difference of about 1 μm is inevitable. Usually, in the black matrix having a line width of about 10 μm, when the difference between the width W ₁ and the width W ₂ as described above occurs, the vicinity of the joint portion J is recognized as a difference in image quality, and this is the difference in the display image. There was a problem of incurring quality degradation.
[0008]
In order to solve this problem, as shown in FIG. 6, colored layers 115R, 115G, and 115B of three primary colors of R, G, and B are equally spaced (W ₁ ) on a glass substrate 112 through a black matrix 113a. A black matrix 113b having a wide width (W ₂ ) is arranged for each set of the colored layers 115R, 115G, and 115B, and a joining portion J (indicated by a chain line) set to one of the wide black matrix 103b is arranged. A large screen color filter 111 is considered, which is composed of color filters 111A and 111B in which a black matrix or a colored layer is formed on a glass substrate 112 so as to be joined together. In the color filter 111, the line width W ₂ 'of wide black matrix 103b is present joining portion J, between the line width W ₂ of the other wide black matrix 103b, the machine accuracy as described above Even if a difference of about 1 μm occurs, the line width W ₂ itself of the black matrix 113b is wide, so that the difference in image quality in the vicinity of the joint portion J is hardly recognized. However, widening the line width of the black matrix as described above for the purpose of not recognizing the presence of the joint portion J causes a problem that the aperture ratio of the color filter is lowered and the display image becomes dark. .
[0009]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a color filter that enables the manufacture of a large-screen color liquid crystal display device excellent in display quality.
[0010]
[Means for Solving the Problems]
In order to achieve such an object, the present invention includes a substrate, a plurality of pixels arranged in a predetermined pattern on the substrate, and a black matrix formed in a non-pixel formation region. In the color filter formed so that the pattern of the black matrix and the pixels are connected at the connecting portion by performing multiple exposures using a photomask or exposure apparatus smaller than the area of each pixel, each pixel is colored in multiple colors consists sequences layers adjacent, the black matrix has a pattern which the black matrix of the same width which is set within the range of 10~50μm are periodically arranged, wherein the stitched portion is present in the black matrix It was set as such.
[0011]
In addition, the plurality of color layers constituting each pixel are configured to be repeatedly arranged in a predetermined color order a plurality of times .
[0012]
In the present invention, when a joining portion is set to one black matrix and a plurality of color filters are joined to form a color filter for a large screen, black matrices having the same width are periodically arranged. Therefore, even if there is a difference in the line width in terms of processing accuracy between the black matrix of the joining portion and the other black matrix, it cannot be recognized as a difference in image quality in the liquid crystal display device, Since the aperture ratio in each pixel composed of an array of colored layers of a plurality of colors is extremely large, the aperture ratio of the entire color filter becomes high.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the drawings.
[0014]
FIG. 1 is a partial plan view showing an example of an embodiment of a color filter of the present invention, and FIG. 2 is a longitudinal sectional view taken along line AA. 1 and 2, the color filter 1 of the present invention is composed of color filters 1A and 1B, and the color filters 1A and 1B are exposed a plurality of times using a photomask, an exposure apparatus or the like that is smaller than the area of the substrate. In this way, the pattern of the black matrix and the colored layer is joined at the joining portion J (indicated by a chain line).
[0015]
The color filter 1 of the present invention includes a substrate 2, a black matrix 3 formed on the substrate 2, and pixels 4 arranged in a predetermined pattern. Each pixel 4 has a red colored layer 5R and a green colored layer 5G. And the blue colored layer 5B is arranged and configured to be adjacent in this order in a certain direction (the direction of arrow a in FIG. 1).
[0016]
In the color filter 1, the pixels 4 are arranged at equal intervals W ₁ in the direction of arrow a in FIG. 1 (colored layer arrangement direction), and in the direction perpendicular to this (in the direction of arrow b in FIG. 1 (length of the colored layer). In the vertical direction)), constant intervals W ₂ and W ₃ are alternately arranged.
[0017]
The black matrix 3 is formed on the non-formation region of the pixel 4, therefore, a black matrix 3a linewidth in the direction of the arrow b in FIG. 1 have the same width W ₁ are periodically arranged, which perpendicular in the direction (direction of arrow a in FIG. 1), a black matrix 3b line width is the same width W _2, a black matrix 3c line width is the same width W ₃ is periodically arranged pattern Have.
[0018]
In such a color filter 1, the line width W ₁ of the black matrix 3a periodically arranged in the arrangement direction of the colored layers 5R, 5G, and 5B can be set within a range of 10 to 50 μm. Further, colored layers 5R, 5G, 5B length line width W of the line width W ₂ and a black matrix 3c of periodically disposed a black matrix 3b in direction ₃ can be set in the range of 50μm or less . If the line width of the black matrix 3 is less than the above range, the quality of the display image is deteriorated due to an error in processing accuracy in the black matrix 3a in which the color filters 1A and 1B are connected, and the line width is If the above range is exceeded, the aperture ratio of the color filter is lowered, and the display image on the liquid crystal display device becomes dark, which is not preferable.
[0019]
Each colored layer 5R, 5G, 5B constituting each pixel 4 has a width (length in the direction of arrow a in FIG. 1) of 50 to 100 μm and a length (length in the direction of arrow b in FIG. 1) of 150 μm or more. Moreover, it is preferable to set the length of the pixel 4 in the direction of arrow a in FIG. 1 to 150 to 300 μm and the length in the direction of arrow b to 150 μm or more. Note that the arrangement order of the colored layers 5R, 5G, and 5B constituting the pixel 4 is not limited to the illustrated example.
[0020]
Color filter 1A, the color filter 1 for a large screen by connecting the 1B in one of the black matrix. 3a, the width W ₁ of the black matrix 3a of the boundary portion of each pixel 4, a black matrix 3a there is a joining portion J between the width W ₁ 'of, even if a 1μm about differences in processing precision, since those width W ₁ of the black matrix 3a is wide, as the difference of the image quality of the stitching unit J vicinity in the liquid crystal display device It is not recognized and the quality of the displayed image is not degraded. Furthermore, since each pixel 4 is formed by arranging a plurality of colored layers 5R, 5G, and 5B adjacent to each other and the aperture ratio is extremely large, the aperture ratio of the entire color filter 1 is high, and the display image on the liquid crystal display device becomes bright. .
[0021]
In the color filter 1 (1A, 1B) described above, the black matrix that is periodically arranged in the direction of the arrow a in FIG. 1 has one line width. The black matrix having two or more line widths may be periodically arranged. In addition, the black matrix arranged in the direction of the arrow b in FIG. 1 has two types of line widths, but may be one type or three or more types within the settable range of the above line widths.
[0022]
The substrate 2 constituting the color filter 1 has flexibility such as a non-flexible transparent rigid material such as quartz glass, pyrex glass, and synthetic quartz plate, or a transparent resin film and an optical resin plate. A transparent flexible material can be used. Among them, Corning 7059 glass is a material having a small coefficient of thermal expansion, excellent dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the active matrix. Suitable for color filters for color liquid crystal display devices.
[0023]
Further, the black matrix 3 constituting the color filter 1 is formed on the substrate 2 so as to be joined at the joining portion J. As a forming method, a thickness of 1000 to 2000 mm is formed by a sputtering method, a vacuum deposition method or the like. A method of forming a metal thin film such as chromium and patterning the thin film, and forming a resin layer of polyimide resin, acrylic resin, epoxy resin, etc. containing light shielding particles such as carbon fine particles and metal oxide Then, this resin layer is patterned by a photosensitive resin, and is formed by etching and peeling. A photosensitive resin layer containing light shielding particles such as carbon fine particles and metal oxide is formed. Any method such as patterning may be used.
[0024]
The colored layers 5R, 5G, and 5B are formed on the substrate 2 so as to be joined at the joining portion J, and may be formed by a pigment dispersion method using a photosensitive resin containing a desired coloring material. Furthermore, it can be formed by a known method such as a printing method, an electrodeposition method, or an electrolytic micelle method. In addition, the colored layers 5R, 5G, and 5B, for example, the red colored layer 5R is the thinnest, the green colored layer 5G and the blue colored layer 5B are thickened in this order, so that the optically optimal liquid crystal thickness for each color of the colored layer A so-called multi-gap color filter may be used.
[0025]
The color filter of the present invention can include a transparent conductive film and an oxygen blocking film so as to cover the black matrix and the pixels. The transparent conductive film uses indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), etc., and alloys thereof, etc., and a general film forming method such as a sputtering method, a vacuum evaporation method, a CVD method, etc. Can be formed. The thickness of such a transparent conductive film is about 0.01 to 1 μm, preferably about 0.03 to 0.5 μm. As the oxygen barrier film, polyvinyl alcohol is usually used.
[0026]
FIG. 3 is a partial plan view showing another example of the embodiment of the color filter of the present invention. In FIG. 3, the color filter 11 of the present invention performs a plurality of exposures using a photomask, an exposure apparatus, or the like that is smaller than the area of the substrate, so that a black matrix or coloring is formed at the joint J (indicated by a chain line). The color filters 11A and 11B are formed so as to connect the layer patterns.
[0027]
The color filter 11 of the present invention includes a substrate 12, a black matrix 13 formed on the substrate 12, and pixels 14 arranged in a predetermined pattern. Each pixel 14 has a red colored layer 15R and a green colored layer 15G. In addition, the blue colored layer 15B is repeatedly arranged twice so as to be adjacent in this order in a certain direction (the direction of arrow a in FIG. 3).
[0028]
In the color filter 11, the pixels 14 are arranged at equal intervals W ₁ in the direction of arrow a in FIG. 3, and are arranged at equal intervals W ₂ in the direction perpendicular to this (in the direction of arrow b in FIG. 3).
[0029]
In the black matrix 13 formed in the non-formation region of the pixel 14, the black matrix 13 a having a line width W ₁ is periodically arranged in the direction of the arrow a in FIG. 3 of arrow b direction) to the black matrix 13b line width is the width W ₂ has periodically arranged pattern.
[0030]
In such a color filter 11, the line width W ₁ of the black matrix 13 a can be set within the range of 10 to 50 μm, similarly to the line width W ₁ of the black matrix 3 a in the color filter 1 described above, and the black matrix 13 b The line width W ₂ can be set within a range of 50 μm or less, like the line widths W ₂ and W ₃ of the black matrix 3b in the color filter 1 described above.
[0031]
Since the formation of the substrate 12, the black matrix 13, and the colored layers 15R, 15G, and 15B constituting the color filter 11 can be the same as that of the color filter 1 described above, description thereof is omitted here.
[0032]
The color filter of the present invention may include a fine black matrix between the colored layers constituting the pixels. FIG. 4 is a plan view showing an example of a pixel of such a color filter. In FIG. 4, the pixels 24 constituting the color filter of the present invention are arranged so that the red colored layer 25R, the green colored layer 25G, and the blue colored layer 25B are adjacent to each other in this order in a certain direction. Is provided with a fine black matrix 23 ′, and a black matrix 23 is provided between the pixels 24. The line width of the black matrix 23 ′ interposed between such colored layers is preferably 30 μm or less, and if the line width exceeds 30 μm, the aperture ratio of the pixel is undesirably lowered.
[0033]
In the example of the color filter described above, the color filters are connected in the arrangement direction of the colored layers constituting each pixel (the direction of the arrow a in FIGS. 1 and 3), but the length of the colored layer constituting each pixel is long. Color filters can also be connected in the vertical direction (the direction of arrow b in FIGS. 1 and 3).
[0034]
【Example】
Next, an Example is shown and this invention is demonstrated further in detail.
[0035]
As a substrate for a color filter, a glass substrate (Corning 7059 glass) having a thickness of 650 mm × 550 mm and a thickness of 1.1 mm was prepared. A light-shielding layer (thickness 0.2 μm) made of chromium metal is formed on the entire surface of one side of this substrate by sputtering, and a joining portion is set at the position of one black matrix having a line width W ₁ with respect to this light-shielding layer. As described above, a black matrix having a pattern as shown in FIG. 1 was formed by performing operations including photosensitive resist coating, mask exposure, development, etching, and resist layer peeling twice by an ordinary photolithography method. The line widths W ₁ , W ₂ , W ₃ and the formation pitch of this black matrix were set as follows.
[0036]
・ W ₁ = 30μm, Pitch = 300μm
・ W ₂ = 30μm, Pitch = 300μm
・ W ₃ = 30 μm, Pitch = 300 μm
Next, a photosensitive coloring material for a red coloring layer (Color Mosaic CR-7000 manufactured by Fuji Film Orin Co., Ltd.) is applied to the entire surface of the substrate on which the black matrix is formed by a spin coating method, and a red photosensitive resin layer ( A thickness of 1.5 μm) was formed and prebaked (100 ° C., 3 minutes). Next, a joining portion is set at the same position as the above-described black matrix formation, and the red photosensitive resin layer is subjected to alignment exposure twice using a predetermined coloring pattern photomask, and a developer (Fuji Film Ohlin Co., Ltd.) Development was performed using CD), and then post-baking (200 ° C., 30 minutes) was performed to form a red colored layer at a predetermined position with respect to the black matrix pattern.
[0037]
Similarly, the green coloring layer was formed in the predetermined position with respect to the black matrix pattern using the photosensitive coloring material for green coloring layers (Fuji Film Orin Co., Ltd. color mosaic CG-7000). Furthermore, a blue colored layer is formed at a predetermined position with respect to the black matrix pattern by using a photosensitive colored material for a blue colored layer (Color Mosaic CB-7000, manufactured by Fuji Film Orin Co., Ltd.), a red colored layer, Pixels (270 μm × 270 μm) were formed in which the green colored layer and the blue colored layer were arranged so as to be adjacent in this order in a certain direction.
[0038]
Next, a transparent conductive layer (thickness 0.15 μm) was formed by sputtering under the following conditions so as to cover the black matrix and the colored layer, and a large area (608 mm × 465 mm) color filter was formed.
[0039]
Sputtering conditions / equipment: DC magnetron sputtering apparatus / substrate temperature: 220 ° C.
And discharging gas: Ar-O ₂
・ Target: Indium tin oxide (ITO)
The line width of the black matrix at the joining portion in this color filter was W ₁ ± 1 μm.
[0040]
Next, after providing a polyimide alignment layer on the transparent conductive layer of this color filter and performing an alignment treatment (rubbing), it is bonded to a TFT array substrate using an epoxy resin sealant, and the TN type liquid crystal is combined with the color filter and the TFT array. It was enclosed in the gap between the substrate. The produced liquid crystal display device obtained good display quality without causing color unevenness or the like in the joining portion.
[0041]
On the other hand, a color filter having a large area (608 mm × 465 mm) was prepared in the same manner as the color filter except that a black matrix having a pattern as shown in FIG. 6 was formed under the following setting conditions.
[0042]
・ W ₁ = 50 μm, Pitch = 300 μm
・ W ₂ = 30μm, Pitch = 300μm
The line width of the black matrix at the joining portion in this color filter was W ₂ ± 1 μm.
[0043]
Next, using this color filter, a liquid crystal display device was produced in the same manner as described above. Although the produced liquid crystal display device did not show color unevenness or the like at the joining portion, the screen was dark and good display quality could not be obtained.
[0044]
【The invention's effect】
As described above in detail, according to the present invention, a plurality of pixels comprising an array of colored layers of a plurality of colors are provided in a predetermined pattern on a substrate, and a black matrix is provided in a non-formation region of the pixels. Since the color filter has a pattern in which black matrices of the same width are periodically arranged, when a black matrix pattern and a colored layer pattern are connected in a single black matrix to form a color filter for a large screen In addition, since the black matrix with the same width is periodically arranged, even if there is a difference in the line width in terms of processing accuracy between the black matrix at the joining portion and the other black matrix, in the liquid crystal display device It will not be recognized as a difference in image quality, and it will not degrade the displayed video quality. Furthermore, since each pixel is composed of an array of colored layers of multiple colors and the aperture ratio is extremely large, the aperture ratio of the entire color filter is high, and the display image on the liquid crystal display device is bright, which results in a large display quality. A color liquid crystal display device for the screen becomes possible.
[Brief description of the drawings]
FIG. 1 is a partial plan view showing an example of an embodiment of a color filter of the present invention.
2 is a longitudinal sectional view taken along line AA of the color filter of the present invention shown in FIG.
FIG. 3 is a partial plan view showing another example of the embodiment of the color filter of the present invention.
FIG. 4 is a partial plan view showing another example of the embodiment of the color filter of the present invention.
FIG. 5 is a partial plan view showing an example of a conventional color filter.
FIG. 6 is a partial plan view showing another example of a conventional color filter.
[Explanation of symbols]
1 (1A, 1B), 11 (11A, 11B) ... color filters 2, 12 ... substrates 3 (3a, 3b, 3c), 13 (13a, 13b), 23, 23 '... black matrices 4, 14, 24 ... Pixels 5R, 5G, 5B, 15R, 15G, 15B, 25R, 25G, 25B ... colored layers

Claims (2)

A substrate, a plurality of pixels arranged in a predetermined pattern on the substrate, and a black matrix formed in a non-formation region of the pixels, and a plurality of pixels using a photomask or exposure apparatus smaller than the area of the substrate In the color filter formed by stitching the black matrix and pixel pattern at the stitching part by performing the double exposure,
Each pixel consists of an arrangement in which multiple colored layers are adjacent ,
The color filter, wherein the black matrix has a pattern in which black matrices of the same width set within a range of 10 to 50 μm are periodically arranged, and the joining portion exists in the black matrix. .   The color filter according to claim 1, wherein the colored layers of the plurality of colors constituting each pixel are repeatedly arranged in a predetermined color order a plurality of times.

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