JP2007114320A - Liquid crystal display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display apparatus capable of enhancing the display quality. <P>SOLUTION: The liquid crystal display apparatus is provided with a color filter substrate, wherein color filters comprising color layers of at least four colors are disposed in each pixel region. In the color filter substrate, light-shielding layers are disposed in between the color filters and between the color layers and the width of the light-shielding layers between the color filters is wider than that between the color layers. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a liquid crystal display device. More specifically, the present invention relates to a liquid crystal display device suitably used for a large liquid crystal television (TV) that performs multi-primary color display.

Liquid crystal display devices are now widely used, and further spread is expected in the future. Under such circumstances, there are active activities aimed at reproducing a wider range of colors than ever before, and in the future, as a matter of course, it is a highly promising technical field including television (TV).

In general, in order to realize color display, a liquid crystal display device is provided with a color filter substrate in which colored layers of several colors are arranged on a substrate for each pixel. However, most conventional liquid crystal display devices use three primary color layers of red (R), green (G), and blue (B), and only the colors inside the RGB triangles in the xy chromaticity diagram. Since it cannot be reproduced, there is room for improvement in that the saturation of cyan (C), which is the complementary color of R, magenta (M), which is the complementary color of G, and yellow (Y), which is the complementary color of B, is reduced. It was.

On the other hand, attempts to display a wide color reproduction range using more than three colors have recently been activated. For example, in addition to the RGB colored layers, cyan (C), magenta (M), and yellow (Y) colored layers may be added. As a form having such a colored layer of six primary colors, as shown in FIG. 3, one in which the area ratio between sub-pixels is adjusted is disclosed (for example, see Patent Document 1). However, according to this embodiment, since the number of colored layers constituting one color filter is larger than in the case having three primary color layers, the interference between pixels increases and the image becomes unclear. There was room for improvement in terms of becoming. In addition, since the pixel pitch is increased, the resolution is reduced, and as a result, when the pixel size is large, there is room for improvement in that a feeling of roughness appears on the screen when a specific color is produced. Note that a color reproduction system that can accurately reproduce the side colors, has continuity between XYZ and signal values, and uses the color reproduction range to the maximum is disclosed (for example, see Patent Document 2). )), This color reproduction system does not reduce the unclearness of the image or the roughness of the screen.
International Publication No. 03/088203 Pamphlet JP 2000-253263 A

The present invention has been made in view of the above-described present situation, and an object thereof is to provide a liquid crystal display device capable of improving display quality.

The inventor conducted various studies on a liquid crystal display device including a color filter substrate in which a color filter composed of at least four colored layers is arranged for each pixel region, and focused attention on interference between pixels. Then, by arranging a light shielding layer between the color filters and between the colored layers, and by making the width between the color filters larger than the width between the colored layers, it is possible to reduce the interference between the pixels, resulting in image blurring. It has been found that the display quality can be reduced and the above problems can be solved brilliantly, and the present invention has been achieved.

That is, the present invention is a liquid crystal display device including a color filter substrate in which a color filter composed of at least four colored layers is arranged for each pixel region, and the color filter substrate is shielded between color filters and between colored layers. The light shielding layer is a liquid crystal display device in which the width between the color filters is larger than the width between the colored layers.
The present invention is described in detail below.

The liquid crystal display device of the present invention includes a color filter substrate in which a color filter composed of at least four colored layers is arranged for each pixel region. The colored layer is not particularly limited as long as it selectively transmits visible light in a predetermined wavelength range of incident light, and examples thereof include a film made of a photosensitive resin in which a pigment is dispersed. It is done. In the present invention, a set of at least four colored layers is arranged for each pixel region as a color filter, and the luminance of light transmitted through each colored layer is adjusted to display a desired color for each pixel. Is possible. The color combination of the colored layers is not particularly limited. For example, the four primary colors of red (R), green (G), blue (B) and yellow (Y) or cyan (C), R, G, B , Y and C, and R, G, B, Y, C, and magenta (M). The pixel is a minimum display unit of a color image, and in the present invention, it is composed of at least four color dots (subpixels). Note that in this specification, the pixel region is a region corresponding to one pixel in the liquid crystal display device of the present invention.

In the color filter substrate, a light shielding layer is disposed between the color filters and between the colored layers, and the light shielding layer has a width between the color filters larger than a width between the colored layers. By disposing a light shielding layer between the color filters and between the colored layers, it is possible to prevent light leakage in a region that is not effective for display, such as between pixel electrodes, and to ensure contrast. Also, by making the width between the color filters larger than the width between the colored layers, interference between pixels can be reduced, and a color with high saturation can be exhibited for each pixel, thereby reducing image blurring. Can do. The light shielding layer preferably has a width between color filters of 2.5 times or more a width between colored layers. If it is less than 2.5 times, a clear image may not be provided.

Examples of the light-shielding layer include those formed of a resin material containing a black colorant, those provided with light-shielding properties by superimposing a plurality of colored layers, and those made of chromium. From the viewpoint of low cost, those formed of a resin material containing a black colorant and those provided with light shielding properties by overlapping a plurality of colored layers are preferable. Examples of the black colorant include carbon black, a black organic pigment, and a black inorganic pigment. Examples of the resin material include an acrylic photosensitive resin and a polyimide non-photosensitive resin.

The liquid crystal display device of the present invention is not particularly limited as long as it includes the color filter substrate as a component, and may or may not include other components. The liquid crystal display device of the present invention usually comprises various optical films such as a TFT array substrate, a liquid crystal layer, a polarizing plate and a retardation film as constituent elements.

A preferred embodiment of the liquid crystal display device of the present invention will be described in detail below.
The color filter is preferably one in which at least four colored layers are fitted and arranged. According to this, since the individual colored layers constituting the color filter are arranged in an intricate manner, the feeling of roughness of the screen can be reduced as compared with a normal structure.
In the present specification, the fitting arrangement means that a set of colored layers arranged in a row and another set of colored layers arranged in a row are fitted when viewed in plan. It means that there is a relationship that looks like. Further, the planar shape of the color filter is preferably a square such as a square or a substantially rectangular shape, and more preferably a substantially rectangular shape. In the present specification, the term “substantially rectangular” includes not only a rectangular shape but also what can be equated with a rectangular shape from the viewpoint of the present invention and its effects.

In the fitting arrangement, it is preferable that the light shielding layer between the colored layers has a stepped structure in at least one of the row direction and the column direction. According to this, the feeling of roughness of the screen can be further reduced. As a preferable form of the color filter, for example, it is composed of six colored layers of a quadrangle arranged in two rows and three columns, and the three colored layers arranged in the first row in a plan view form a convex shape. The three colored layers arranged in the second row form a concave shape, and the convex shape and the concave shape are fitted (for example, the form shown in FIG. 2A). Is mentioned. The planar shape of the color filter is preferably a square such as a square or a substantially rectangular shape, and more preferably a substantially rectangular shape.

In the color filter, the light shielding layer between the colored layers preferably has a wave shape in at least one of the row direction and the column direction. Also by this, since the individual colored layers constituting the color filter are arranged in an intricate manner, the feeling of roughness of the screen can be reduced as compared with a normal structure. As a preferred form of the color filter, for example, it is composed of 6 colored layers arranged in 2 rows and 3 columns, and is arranged in 3 colored layers arranged in the 1st row and 2nd row when viewed in plan. The form (for example, the form shown to FIG.2 (b) and (c)) which the light shielding layer arrange | positioned between three colored layers is bent is mentioned.
The planar shape of the color filter is preferably a square such as a square or a substantially rectangular shape, and more preferably a substantially rectangular shape.

In the liquid crystal display device, it is preferable that the sub-pixel is driven in an inverted manner for each pixel. As a result, the polarity of the driving voltage of the corresponding sub-pixel of each pixel is inverted for each pixel, so that flicker, image sticking, etc. that occur when a specific color is produced can be reduced. For example, when the color filter is composed of 6 colored layers arranged in a matrix of 3 rows and 2 columns, the liquid crystal display device is driven (vertically) so that the polarity of the drive voltage is inverted every 2 dots in the column direction. 2 dot inversion drive) is preferable.

The liquid crystal display device has a liquid crystal alignment control structure on the liquid crystal layer side of the color filter substrate and / or the substrate facing the color filter substrate, and the liquid crystal alignment control structure has substantially the same structure for each subpixel. It is preferable to have. Thereby, since the viewing angle characteristics can be made substantially the same between the sub-pixels, the color shift when viewed from an oblique direction can be reduced. Examples of the orientation control structure include a protrusion structure and a slit. Examples of the material of the protruding structure include a low dielectric insulating material, and examples of the slit include those provided on the pixel electrode and the counter electrode.

In the liquid crystal display device, the display mode is preferably a vertical alignment mode, and the liquid crystal alignment control structure is preferably substantially cross-shaped. By adopting the vertical alignment mode as the display mode of the liquid crystal display device, the contrast can be improved, and the substantially cross-shaped liquid crystal alignment control structure faces the color filter substrate and / or the color filter substrate. By providing on the liquid crystal layer side of the substrate, the viewing angle characteristics can be made substantially the same between the sub-pixels. The substantially cross-shaped liquid crystal alignment control structure can be applied to color filters of various layouts.

Note that the vertical alignment mode is a method in which liquid crystal molecules are aligned substantially perpendicular to the substrate surface when no voltage is applied, and display is performed by tilting the liquid crystal molecules when a voltage is applied. Examples of the vertical alignment mode include an MVA (Multi-domain Vertical Alignment) mode in which the liquid crystal cell is divided into a plurality of domains by the liquid crystal alignment control structure. Note that in the vertical alignment mode liquid crystal display device, the liquid crystal molecules preferably have negative dielectric anisotropy.

According to the color filter substrate of the present invention, the interference between pixels can be reduced by making the width of the light shielding layer between the color filters larger than the width of the light shielding layer between the colored layers. And display quality can be improved.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1
FIG. 1 is a schematic plan view illustrating a configuration of a color filter according to Embodiment 1 of the present invention.
In this embodiment, the width between the BM color pixels is 100 μm, the width within the color pixels (colored layers) is 40 μm, the color pixel pitch is about 1000 μm, and the total number of color pixel units is 1365 (horizontal) × 768 (vertical). A part of the 60-inch panel was designed and prototyped. Table 1 shows the color pixel pitch and the width of the BM.

(Comparative Example 1)
This comparative example is the same as Example 1 except that the width between BM color pixels is 40 μm. Table 1 shows the color pixel pitch and the width of the BM.

<Comparison between Example 1 and Comparative Example 1>
In multi-primary color display, the pixel arrangement becomes more complex than in the prior art, and the number of color sub-pixels (colored layers) constituting the color pixel is approximately doubled. The panel manufactured in this example was clarified in units of color pixels (color filters) by being surrounded by a black matrix (BM) 11 having a large width for each pixel. That is, since there is no interference between adjacent color pixels, a clear color can be exhibited for each color pixel, and it was confirmed that a clear display was possible as compared with the panel prototyped in Comparative Example 1.

As in the present embodiment, by making the width between the color pixels of the BM wider than the width within the color pixels, it is possible to improve image quality and provide a particularly clear image. In this embodiment, the width between BM color pixels is set to 100 μm, but this value may be appropriately selected according to the size of the display, the pixel size, and the like.

(Examples 2 to 4)
FIGS. 2A to 2C are schematic plan views illustrating configurations of color filters according to Embodiments 2 to 4 of the present invention.
As shown in FIGS. 2A to 2C, the color filters according to Examples 2 to 4 have red (R), green (G), blue (B), cyan (C), magenta (M), and It consists of colored layers of six primary colors of yellow (Y). As shown in FIG. 2 (a), the color filter according to Example 2 has a quadrangular planar shape and is composed of six colored layers of quadrangles arranged in two rows and three columns. The three colored layers 10R, 10M, and 10B arranged in the eyes form a concave shape, and the three colored layers 10C, 10G, and 10Y arranged in the second row form a convex shape. And a convex shape are fitted. In addition, as shown in FIG. 2 (b), the color filter according to Example 3 has a square planar shape, and is composed of six colored layers arranged in two rows and three columns. The light shielding layer 11 is bent between a set of three colored layers 10R, 10G, and 10B arranged in the eye and a set of three colored layers 10C, 10M, and 10Y arranged in the second row. ing. Further, as shown in FIG. 2C, the color filter according to Example 4 has a quadrangular planar shape, and is composed of six colored layers arranged in two rows and three columns. The light-shielding layer 11 is bent between a set of three colored layers 10R, 10M and 10B arranged in the eye and a set of three colored layers 10C, 10G and 10Y arranged in the second row. ing. 2A and 2C, the R, G, and B colored layers are arranged at positions corresponding to different scan lines, and in FIG. 2B, the R, G, and B colored layers are arranged. Are placed on the same line.

(Comparative Example 2)
FIG. 3 is a schematic plan view illustrating a configuration of a color filter according to Comparative Example 2.
As shown in FIG. 3, the color filter according to Comparative Example 2 is also composed of colored layers of six primary colors of R, G, B, C, M, and Y. Note that the colored layers of R, G, and B are arranged in the same row.

<Comparison between Examples 2 to 4 and Comparative Example 2>
According to the configuration of the color filter according to the second to fourth embodiments, since the sub-pixels of the respective primary colors are arranged in an intricate manner, the comparative example is good even when the pixel size is large from the viewpoint of resolution. Compared with the configuration of the color filter according to 2, it was possible to reduce the roughness of the screen.

<Comparison between Examples 5 and 6 and Comparative Example 3>
FIGS. 4A and 4B are schematic plan views showing configurations of color filters according to Examples 5 and 6 of the present invention. FIG. 5 is a schematic plan view showing a configuration of color filters according to Comparative Example 3. FIGS. FIG.
In this embodiment, the drive polarity is limited. One driving polarity widely used in conventional TFT liquid crystal displays is vertical and horizontal 1-dot inversion driving. As shown in FIG. 5, when vertical and horizontal 1-dot inversion driving is applied to a multi-primary color system composed of 6 subpixels arranged in a matrix of 3 rows and 2 columns, subpixels corresponding to the respective primary colors are obtained. When the same polarity is displayed in the vertical direction and a specific color is displayed, flicker becomes conspicuous. In addition, the fact that the flicker is conspicuous affects the burn-in characteristics in terms of reliability. In this case, the burn-in becomes noticeable when a specific color is displayed instead of the colorless burn-in, so that it is remarkably noticeable as compared with the burn-in in the gray display, and improvement is essential.

For this, as shown in FIG. 4A, vertical two-dot inversion driving may be applied. FIG. 4B shows another example in which vertical two-dot inversion driving is applied. According to this, all the subpixels and the surrounding corresponding subpixels of the same color can be in a dot inversion relationship. Therefore, when the same panel was used and the difference by the drive method was confirmed, when the drive method shown to FIG. 4 (a) and (b) is applied, compared with the case where the drive method shown in FIG. 5 is applied. Flicker and image sticking were reduced.

In addition, considering the capacitance between the gate electrode, the pixel electrode, and the data electrode so that the same voltage (absolute value) is applied to each pixel with positive and negative polarities as much as possible, the size of the storage capacitor Cs is also sub It is premised on optimization including pixels. This is because sufficient characteristics and reliability cannot be obtained even if only the driving conditions are changed.

(Examples 7 to 10)
FIGS. 6-9 (a) is a schematic plan view showing the configuration of the color filter according to Examples 7-10 of the present invention, and FIG. 6 (b) is a schematic plan view showing the configuration of the liquid crystal alignment control structure. 6 to 9 (b), solid black lines and broken lines indicate liquid crystal alignment control structures (projection structures or electrode slits made of a low dielectric insulating material), and the substrates to be formed are different. It is shown that.
In a multi-primary color display panel, the pixel layout is more complicated than in the prior art. Therefore, if the viewing angle characteristics are not the same for each sub-pixel, the color shift when viewed from an oblique angle will increase, and even if a wide color reproduction range is obtained by multi-primary color display, high-quality display will be significantly impaired. It will be.

Therefore, the display mode is set to the vertical alignment mode, and as shown in FIGS. 6B and 7B, the shape of the liquid crystal alignment control structure is a cross shape having excellent symmetry. Visual angle characteristics can be aligned. Also, as shown in FIGS. 6A and 7A, the cross-shaped liquid crystal alignment control structure is made efficient by designing the area of the CYM subpixel to be approximately ½ of the RGB subpixel. Can be arranged. This sub-pixel ratio is considered to be suitable for minimizing the difference in response speed between the sub-pixels as much as possible.

As described above, the display quality of the multi-primary color display liquid crystal panel can be improved by aligning the viewing angle characteristics of the individual sub-pixels (preferably including the response characteristics). In particular, in a vertical alignment type liquid crystal display panel, since it is currently essential to adopt a multi-domain structure, the characteristics of individual sub-pixels can be easily matched by using a cross-shaped arrangement pattern as a domain control means. be able to. Also, as shown in FIGS. 8B and 9B, the cross-shaped arrangement pattern is between three subpixels arranged in the first row and three subpixels arranged in the second row. It can be easily applied to a layout in which the boundary line is bent.

It is a plane schematic diagram which shows the structure of the color filter which concerns on Example 1 of this invention. (A)-(c) is a plane schematic diagram which respectively shows the structure of the color filter which concerns on Examples 2-4 of this invention. 10 is a schematic plan view illustrating a configuration of a color filter according to Comparative Example 2. FIG. (A) And (b) is a plane schematic diagram which shows the structure of the color filter which concerns on Example 5 and 6 of this invention. 10 is a schematic plan view illustrating a configuration of a color filter according to Comparative Example 3. FIG. (A) is a plane schematic diagram which shows the structure of the color filter which concerns on Example 7 of this invention, (b) is a plane schematic diagram which shows the structure of the liquid crystal orientation control structure which concerns on Example 7. FIG. (A) is a plane schematic diagram which shows the structure of the color filter which concerns on Example 8 of this invention, (b) is a plane schematic diagram which shows the structure of the liquid crystal alignment control structure based on Example 8. FIG. (A) is a plane schematic diagram which shows the structure of the color filter which concerns on Example 9 of this invention, (b) is a plane schematic diagram which shows the structure of the liquid crystal alignment control structure concerning Example 9. FIG. (A) is a plane schematic diagram which shows the structure of the color filter which concerns on Example 10 of this invention, (b) is a plane schematic diagram which shows the structure of the liquid crystal alignment control structure concerning Example 10. FIG.

Explanation of symbols

10B, 50B: Blue colored layer (blue subpixel)
10C, 50C: cyan colored layer (cyan subpixel)
10G, 50G: green colored layer (green subpixel)
10M, 50M: magenta colored layer (magenta subpixel)
10R, 50R: Red colored layer (red subpixel)
10Y, 50Y: Yellow colored layer (yellow subpixel)
11, 51: Black matrix (light shielding layer)
12: Liquid crystal alignment control structure

Claims (9)

A liquid crystal display device comprising a color filter substrate in which a color filter composed of at least four colored layers is arranged for each pixel region,
In the color filter substrate, a light shielding layer is disposed between the color filters and between the colored layers,
The liquid crystal display device, wherein the light shielding layer has a width between the color filters larger than a width between the colored layers. The liquid crystal display device according to claim 1, wherein the color filter is formed by fitting and arranging colored layers of at least four colors. 3. The liquid crystal display device according to claim 2, wherein the fitting arrangement is such that the light shielding layer between the colored layers has a stepped structure in at least one of the row direction and the column direction. The color filter is composed of six rectangular colored layers arranged in two rows and three columns. When viewed in plan, the three colored layers arranged in the first row form a convex shape. 2. The liquid crystal display device according to claim 1, wherein the three colored layers arranged constitute a concave shape, and the convex shape and the concave shape are fitted together. 2. The liquid crystal display device according to claim 1, wherein the color filter has a light-shielding layer between colored layers having a wave shape in at least one of a row direction and a column direction. The color filter is composed of six colored layers arranged in two rows and three columns. When viewed in plan, the color filter includes three colored layers arranged in the first row and three colored layers arranged in the second row. 2. The liquid crystal display device according to claim 1, wherein the light shielding layer disposed therebetween is bent. 2. The liquid crystal display device according to claim 1, wherein in the liquid crystal display device, the sub-pixel is driven in an inverted manner for each pixel. The liquid crystal display device has a liquid crystal alignment control structure on the liquid crystal layer side of the color filter substrate and / or the substrate facing the color filter substrate,
2. The liquid crystal display device according to claim 1, wherein the liquid crystal alignment control structure has substantially the same structure for each sub-pixel. In the liquid crystal display device, the display mode is a vertical alignment mode,
9. The liquid crystal display device according to claim 8, wherein the liquid crystal alignment control structure is substantially cross-shaped.

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