KR20040062180A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: An LCD(liquid crystal display) is provided to obtain an image having uniform luminance. CONSTITUTION: An LCD includes a color filter substrate, an array substrate, and a liquid crystal layer. The color filter substrate includes a black matrix arranged in a lattice structure on an upper substrate. The color filter substrate further includes red, green and blue color filters. The red, green and blue color filters are repeatedly arranged on the black matrix in horizontal and vertical directions. The array substrate includes data bus lines and gate bus lines arranged in an intersecting manner on a lower substrate and pixel electrodes respectively disposed at the intersections of the gate bus lines and data bus lines. The liquid crystal layer is interposed between the color filter substrate and array substrate.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device in which a color filter layer formed on a color filter substrate of an liquid crystal display device is evenly arranged to improve screen quality.

The liquid crystal display is one of the fastest growing flat panel display devices and is expected to lead the display device market in the future. For the high quality and high contrast display of such a liquid crystal display device, it is necessary to form a black matrix having excellent light blocking property between pixels of three colors of red (R), green (G), and blue (B) color filters.

In particular, in the case of an active matrix driving type TFT-LCD using a thin film transistor, high light shielding property is required. In general, a black matrix is formed by forming a metal film such as chromium on a substrate by vacuum deposition or the like, coating a photosensitive resin, and then patterning and etching chromium by a photolithography method.

The black matrix using chromium may be manufactured as a thin film, and has the advantage of obtaining chemical resistance and high light blocking performance, but the high light reflectance may reduce display quality and require a separate processing process for total reflection. And a manufacturing cost increases because a vacuum deposition processor such as chrome sputtering is involved.

In addition, since the chromium etching is required and the waste liquid generated after the etching process causes a problem of environmental pollution, recently, a black matrix using a resin has been actively studied.

In general, a method of forming a black matrix using a resin between color filter layers of red, green, and blue on a color filter substrate may be manufactured by a method such as dyeing, printing, pigment dispersion, and electrodeposition. The matrix is mainly produced by the pigment dispersion method.

The pigment dispersion method is a color filter substrate by coating a photosensitive resin composition containing a colorant on a transparent substrate provided with a black matrix, exposing the pattern to be formed, and then removing a non-exposed portion with a solvent and thermally curing the color filter substrate. It is a method of manufacturing.

The black matrix produced by the pigment dispersion method is composed of two components, a polymer compound that largely supports the role of a support and maintains a certain thickness, that is, a binder resin and a photopolymerizable monomer that reacts with light during exposure to form a photoresist image. And a photosensitive resin composition containing a pigment, a junior initiator, an epoxy resin, a solvent and other additives, etc., in addition to the above components. As the binder resin used in the pigment dispersion method, a photosensitive resin composed of the acrylic polymer and azide compound described is used.

In addition, various kinds of photosensitive resins including a radical polymerization photosensitive resin composed of a known acrylate monomer, an organic polymer binder and a photopolymerization initiator, a phenol resin, a crosslinking agent having an N-methylol structure, and a photoacid generator have been proposed.

In addition, the photosensitive resin which forms an image using an acid generated by exposure has a high sensitivity and is not affected by oxygen when exposed, but a heating process is required during exposure and development, and a heating time is required for pattern formation. It has a problem that it is difficult to control the process because of the sensitive reaction.

1A to 1C are cross-sectional views illustrating a manufacturing process of a color filter substrate of a liquid crystal display according to the related art.

As shown in FIG. 1A, the method of forming the black matrix 101 on the transparent upper substrate 100 may be formed by depositing and patterning an opaque metal having a low reflection characteristic such as chromium (Cr), or using a photosensitive black resin. After coating is formed by exposing and etching it.

Recently, when the chromium film is used as the material of the black matrix, since it is a heavy material, it has a serious effect on environmental pollution. Therefore, patterning is performed using metals other than heavy metals or synthetic resin-based materials.

The black matrix 101 formed on the transparent upper substrate 100 corresponds to the pixels of the active layer on the array substrate, and to prevent light leakage even in the areas corresponding to the gate pad and the data pad region. The black matrix 101 is formed along an edge of the upper substrate 100.

When the black matrix 101 is formed on the transparent upper substrate 100 as described above, as shown in FIG. 1B, the colors of red (103), green (105), and blue (107) are shown. Filter layers R, G, and B are formed.

Usually, the method of forming the color filter layers (R, G, B) is formed by a pigment spraying method, which repeats the process of applying, exposing and patterning a photoresist resist that has been colored and prepared by using a pigment prepared in advance. This is a method of forming a color filter of red, green, and blue.

At this time, an acrylic resin or the like may be used as a material of the color filter. In order to pattern the resin, pre-bake, exposure, development, post-bake Can be patterned through the process.

When the red color filter layer 103 is formed on the lattice space of the black matrix 101, a green photoresist film is then applied, exposed and developed to form the green color filter layer 105. In the same manner, a blue photoresist film is coated on the transparent upper substrate 100 on which the red and green color filter layers 103 and 105 are formed, and then exposed and developed to form a blue color filter layer to form the red and green blue color filter layers 107. Form.

When the R, G, and B color filter layers 103, 105, and 107 are formed as described above, as illustrated in FIG. 1C, the black matrix 101 and the red, green, and blue color filter layers are disposed on the transparent upper substrate 100. In order to planarize when 103, 105, and 107 are formed, an overcoat layer 109 is formed by coating a transparent resin having insulating properties on the upper substrate 100.

Subsequently, although not shown in the drawing, a common electrode is formed and an electric field for twisting the liquid crystal molecules together with the pixel electrode of the array substrate is formed.

FIG. 2 is a view schematically illustrating a structure of a color filter substrate manufactured according to the prior art, and as shown in the drawing, red and green (Red) and green ( Green and Blue color filter layers are formed to be repeated.

The red (R) color filter layer, the green (G) color filter layer, and the blue (B) color filter layer are repeated from left to right along the horizontal axis direction of the color filter substrate, and red from left to right along the next horizontal row. R) The color filter layer, the green (G) color filter layer, and the blue (B) color filter layer are repeated.

A red (R) color filter layer line, a green (G) color filter layer line, and a blue (B) color filter layer line appear in this order along the vertical axis of the color filter substrate.

3 is a view for explaining the structure of the liquid crystal display and the edge region of the liquid crystal display according to the prior art.

As shown in FIG. 3, the liquid crystal display device includes a black matrix 101 and color filter layers 103, 105, and 107 formed on the upper substrate 100 and the lower filter substrate 120. The active layer 123 including the pixel electrode and the switching element formed therein and the array substrate liquid crystal layer 125 having the pad layer 121 for applying driving signals and graphic signals to the array wiring are interposed therebetween.

That is, when the array substrate 200 and the color filter substrate 300 are completed, they are combined to form one liquid crystal cell. Usually, the seal line 111 is coated on the edge of the array substrate 200, and the color filter is applied. On the substrate 300, the spacers are scattered and the two substrates are bonded to each other by ultraviolet irradiation.

The bonded liquid crystal cell functions to seal the liquid crystal layer 125 while the seal line 111 supports two substrates along edges of the color filter substrate 300 and the array substrate 200.

Although not shown in the drawing, a plurality of spacers are distributed between the array substrate 200 and the color filter substrate 300 to maintain a constant cell gap between the two substrates.

The color filter layer forming region of the color filter substrate 300 corresponds to the active layer 123 of the array substrate 200 so that a light source passing through the pixel electrode formed in the active layer 123 passes through the liquid crystal molecules. Through the red, green, and blue color filter layers 103, 105, and 107 of the color filter substrate 300, various colors are realized.

However, in the related art, when the red and green blue color filter layers are repeated in the horizontal direction as in FIGS. 2 and 3, the color filter layers of the left and right edge regions exist only in red and blue.

As such, when the red color filter layer line is formed in the left edge region of the color filter substrate 300 and the blue color filter layer line is formed in the right edge region, the black matrix disposed on the color filter substrate 300 is formed. Although it is arranged to overlap the pixel area somewhat, a bright red line is formed in the left edge area of the displayed area by light diffraction, and a bright blue line is formed in the right edge area (hatching area in FIG. The problem of deterioration arises.

In addition, when the black matrix disposed in the edge region is extended to block such a line, the aperture ratio is reduced and the screen quality is degraded.

In the present invention, when the color filter layer is formed on the color filter substrate of the liquid crystal display device, a region in which R, G, and B are arranged is formed so that a constant red, green, and blue layer is formed in the horizontal and vertical directions. An object of the present invention is to provide a liquid crystal display device capable of obtaining an image having uniform luminance.

1A to 1C are cross-sectional views illustrating a process for manufacturing a color filter substrate of a liquid crystal display device according to the prior art.

2 is a view schematically showing the structure of a color filter substrate manufactured according to the prior art.

3 is a view for explaining the structure of the liquid crystal display device and the edge region of the liquid crystal display device according to the prior art.

4 shows the structure of a color filter substrate according to the invention;

5 is a view showing the structure of a color filter substrate according to another embodiment of the present invention.

6 is a plan view showing the structure of a liquid crystal display device according to the present invention;

* Description of the symbols for the main parts of the drawings *

100; Lower substrate 101: black matrix

103: red color filter layer 105: green color filter layer

107: blue color filter layer 109: overcoat layer

400: array substrate 500: color filter substrate

In order to achieve the above object, the liquid crystal display device according to the present invention,

A black matrix disposed in a lattice structure on the upper substrate;

A color filter substrate on which the red color filter layer, the green color filter layer, and the blue color filter layer are alternately arranged on the black matrix, and the red color filter layer, the green color filter layer, and the blue color filter layer are alternately arranged in the vertical axis direction; ;

An array substrate comprising data bus lines, gate bus lines, and pixel electrodes arranged in a matrix on the lower substrate;

It characterized in that it comprises a liquid crystal layer filled between the color filter substrate and the array substrate.

Here, the color filter layers of the color filter substrate may alternately show different color filter layers in the horizontal and vertical directions, and the black matrix of the edge region of the color filter substrate may reduce its width so as not to overlap the active region. It is done.

In addition, the liquid crystal display device according to another embodiment of the present invention,

A black matrix disposed in a lattice structure on the upper substrate;

The red color filter layer, the green color filter layer, and the blue color filter layer are alternately arranged on the black matrix in the horizontal axis direction, and the red color filter layer, the green color filter layer, and the blue color filter layer are arranged in the same longitudinal direction in a plurality of longitudinal axes. A color filter substrate;

An array substrate comprising data bus lines, gate bus lines, and pixel electrodes arranged in a matrix on the lower substrate;

It characterized in that it comprises a liquid crystal layer filled between the color filter substrate and the array substrate.

Here, the red color filter layer, the green color filter layer, and the blue color filter layer which are repeated in the longitudinal axis in the same direction on the color filter substrate are two to three layers, and the red color filter layer and the green color filter layer in the longitudinal axis direction on the color filter substrate. Different color filter layers are repeated in units of two to three blue color filter layers.

According to the present invention, the red, green, and blue color filter layers are sequentially formed in the color filter layer formed on the color filter substrate in the transverse direction and the longitudinal direction, thereby providing the red color filter layer line, the green color filter layer line, The screen quality is improved by preventing the blue color filter layer lines from appearing alternately.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a view showing the structure of a color filter substrate according to the present invention.

As shown in FIG. 4, the structure of the color filter substrate is formed by depositing a chromium metal film on an upper substrate made of a transparent insulating substrate and etching to form a black matrix having a plurality of lattice structures in which a color filter layer is to be formed.

Each of the black matrices corresponds to a unit pixel of an array substrate, and a red color filter layer, a green color filter layer, and a blue color filter layer are disposed in the grating.

The area where the color filter layer is disposed is an area where an image is implemented as an active area when the liquid crystal display is displayed.

In the method of forming the color filter layer formed on the black matrix, the color resin is formed by the pigment dispersion method as in the method described in the prior art.

The black matrix is formed to correspond to the gate bus lines and the data bus lines of the array substrate and the switching element TFT region of the region where the gate bus lines and the data bus lines intersect to generate light generated in the backlight. Block it.

The color filter layer disposed on the color filter substrate generally has a structure in which the red (R) color filter layer, the green (G) color filter layer, and the blue (B) color filter layer are sequentially repeated from left to right along the transverse direction. The red (R) color filter layer, the green (G) color filter layer, and the blue (B) color filter layer are alternately repeated in the longitudinal axis direction, so that the same color filter layer lines are not formed in the longitudinal axis direction as in the prior art.

That is, in the present invention, the red, green, and blue color filter layers alternately appear along the horizontal and vertical axes along the color filter substrate, thereby causing bright red lines and bright blue lines generated in the edge region. Eliminate lines to improve screen quality.

In addition, the width of the black matrix extending along the edge of the color filter substrate may be reduced outside the active area. Bright luminance was generated in spite of the black matrix formed to overlap with the interference of light, but the width of the black matrix can be reduced due to the repetition of the color filter layer.

5 is a diagram illustrating a structure of a color filter substrate according to another exemplary embodiment of the present invention.

As shown in FIG. 5, although the structure is the same as that of FIG. 4,

The color filter layer disposed on the color filter substrate generally has a structure in which the red (R) color filter layer, the green (G) color filter layer, and the blue (B) color filter layer are sequentially repeated from left to right along the transverse direction. The blue (B) color filter layer, such as the red (R) color filter layer, the green (G) color filter, is repeated in the longitudinal axis direction in one unit.

That is, although the red (R) color filter layer line, the green (G) color filter layer line, and the blue (B) color filter layer line are not formed as in the related art, two or three identical filter layers are repeated in the longitudinal axis direction.

Thus, in the present invention, red and green blue color filter layers alternately appear along the color filter substrate in the horizontal axis direction, but two to three in the vertical axis direction are alternately repeated in the vertical axis direction. As shown in the figure, it can be seen that two red color filter layers, two green color filter layers, and two blue color filter layers repeatedly appear in one unit in the vertical axis direction.

In this way, the red and green blue color filter layers alternately appear along the horizontal and vertical axes along the color filter substrate, thereby eliminating the bright red lines and the bright blue lines generated in the edge region, thereby improving screen quality.

In addition, the width of the black matrix extending along the edge of the color filter substrate may be reduced outside the active area. Bright luminance was generated in spite of the black matrix formed to overlap with the interference of light, but the width of the black matrix can be reduced due to the repetition of the color filter layer.

6 is a plan view showing the structure of a liquid crystal display according to the present invention.

As shown in FIG. 6, in the structure in which the array substrate 400 and the color filter substrate 500 are bonded together, a bright red color and a bright blue color in the related art along the left and right edge lines of the active area. Although (Blue) appears to deteriorate the screen quality, in the present invention, the red color filter layer line and the blue color filter layer line do not come on the color filter substrate of the left and right edge regions of the active area, and red (R), green (G), and blue (B) The screen quality was improved by repeating the color filter layers.

Therefore, in the present invention, the screen deterioration phenomenon occurring at the edge of the displayed area without expanding the black matrix can be solved by changing the layer shape of the color filter layer disposed on the color filter substrate.

As described in detail above, the present invention allows the red, green, and blue color filter layers formed on the color filter substrate to alternately appear in the horizontal direction and the vertical direction, thereby reducing the brightness of the specific color on the edge area and reducing the screen. It has the effect of improving elegance.

In addition, it is possible to reduce the width of the black matrix, which has been expanded to block the bright colored lines generated by the interference of light in the edge region on the color filter substrate, thereby improving the aperture ratio.

The present invention is not limited to the above-described embodiments, and various changes can be made by those skilled in the art without departing from the gist of the present invention as claimed in the following claims.

Claims (6)

A black matrix disposed in a lattice structure on the upper substrate; A color filter substrate on which the red color filter layer, the green color filter layer, and the blue color filter layer are alternately arranged on the black matrix, and the red color filter layer, the green color filter layer, and the blue color filter layer are alternately arranged in the vertical axis direction; ; An array substrate comprising data bus lines, gate bus lines, and pixel electrodes arranged in a matrix on the lower substrate; And a liquid crystal layer filled between the color filter substrate and the array substrate. The method of claim 1, The color filter layer of the color filter substrate, the liquid crystal display, characterized in that the different color filter layers appear alternately in the horizontal axis and the vertical axis direction. The method of claim 1, And the black matrix of the edge region of the color filter substrate can be reduced in width so as not to overlap the active region. A black matrix disposed in a lattice structure on the upper substrate; The red color filter layer, the green color filter layer, and the blue color filter layer are alternately arranged on the black matrix in the horizontal axis direction, and the red color filter layer, the green color filter layer, and the blue color filter layer are arranged in the same longitudinal direction in a plurality of longitudinal axes. A color filter substrate; An array substrate comprising data bus lines, gate bus lines, and pixel electrodes arranged in a matrix on the lower substrate; And a liquid crystal layer filled between the color filter substrate and the array substrate. The method of claim 4, wherein And a red color filter layer, a green color filter layer, and a blue color filter layer which are repeated in the longitudinal axis in the same direction on the color filter substrate. The method of claim 4, wherein And a different color filter layer is repeated on the color filter substrate in units of two to three red color filter layers, green color filter layers, and blue color filter layers in a longitudinal axis direction.