KR20080059868A - Apparatus for fabricating liquid crystal display panel, liquid crystal display panel and method for fabricating using the same - Google Patents

Abstract

An apparatus for manufacturing an LCD(Liquid Crystal Display) panel, an LCD panel using the same and a manufacturing method thereof are provided to make non-refractivity values between upper and lower sides or left and right sides of the LCD panel be same, thereby preventing color difference between the upper and lower sides or left and right sides. A TFT(Thin Film Transistor) array substrate(280) is deposited with a color filter array substrate(270) as leaving a space for LC(252). In the TFT array substrate, a pixel electrode(216) and a common electrode(218) for forming a horizontal electric field are formed. A first alignment layer(208) is formed in the color filter array substrate. A second alignment layer(238) is formed in the TFT array substrate. Each of the first and second alignment layers is divided into first and second alignment areas. The first alignment areas are aligned in a first direction. The second alignment areas are aligned in a second direction opposite to the first direction.

Description

Apparatus for Fabricating Liquid Crystal Display Panel, Liquid Crystal Display Panel And Method for Fabricating Using The Same}

1A to 1C are views illustrating a rubbing process and liquid crystal alignment of an S-IPS mode liquid crystal display panel.

2A to 2C are views illustrating a rubbing process and liquid crystal alignment of an H-IPS mode liquid crystal display panel.

3A and 3B are diagrams for explaining causes of color difference in S-IPS mode and H-IPS mode liquid crystal display panels, respectively.

4 is a cross-sectional view showing a liquid crystal display panel in IPS mode according to an embodiment of the present invention.

FIG. 5 is a diagram schematically illustrating a liquid crystal alignment state by upper and lower alignment layers in an H-IPS mode liquid crystal display panel. FIG.

FIG. 6 is a diagram schematically illustrating a liquid crystal alignment state by upper and lower alignment layers in an S-IPS mode liquid crystal display panel. FIG.

7A and 7B illustrate an apparatus and a rubbing process for manufacturing an S-IPS mode liquid crystal display panel.

8A and 8B illustrate an apparatus and a rubbing process for manufacturing an H-IPS mode liquid crystal display panel.

   <Description of the symbols for the main parts of the drawings>

70,170,270: Color Filter Array Substrate

80,180,280: Thin Film Transistor Array Board

202: upper substrate 204: black matrix

218: common electrode 232: lower substrate

206: color filter 290: liquid crystal display panel

52,252: liquid crystal 215: thin film transistor

213: spacer 216: pixel electrode

62: stage 60, 160: rubbing device

The present invention relates to a liquid crystal display panel, and more particularly, to an apparatus for manufacturing a liquid crystal display panel capable of improving display quality and a method for manufacturing a liquid crystal display panel using the same.

In general, a liquid crystal display (LCD) displays an image corresponding to a video signal on a liquid crystal display panel in which liquid crystal cells are arranged in a matrix form by adjusting light transmittance of liquid crystal cells according to a video signal. To this end, the liquid crystal display device includes a liquid crystal display panel in which liquid crystal cells are arranged in an active matrix form, and driving circuits for driving the liquid crystal display panel.

Such liquid crystal displays are roughly classified into twisted nematic (TN) mode and in plan switch (IPS) mode using a vertical electric field according to the electric field driving the liquid crystal.

The TN mode is a mode in which a liquid crystal is driven by a vertical electric field between a pixel electrode and a common electrode arranged to face the upper substrate. The TN mode has an advantage that the aperture ratio is large while the viewing angle is folded. The IPS mode is a mode in which a liquid crystal is driven by a horizontal electric field between a pixel electrode and a common electrode arranged side by side on a lower substrate, and has a large viewing angle, but a small aperture ratio.

The liquid crystal display panel of the IPS mode has a configuration in which a liquid crystal is injected after the color filter array substrate and the thin film transistor array substrate formed by separate processes are bonded.

The color filter array substrate includes a black matrix, a color filter, an overcoat layer, and an upper alignment layer on the upper substrate.

The thin film transistor array substrate includes a gate line and a data line formed to cross each other, a thin film transistor positioned at an intersection of the data line and the gate line, a pixel electrode in contact with the thin film transistor, a common electrode forming a horizontal electric field with the pixel electrode, and the like. .

The liquid crystal display panel is completed by forming a thin film transistor array substrate and a color filter array substrate by a separate process, forming an alignment layer using a rubbing process, and then bonding the liquid crystal by incorporating a bonding process.

The IPS liquid crystal display panel having such a configuration has a form in which the pixel electrode and the common electrode are bent, and the S (super) -IPS liquid crystal display panel, the pixel electrode and the common electrode, having a structure arranged in parallel to each other in a vertical direction. It can be classified into a H (horizon) -IPS mode liquid crystal display panel having a shape and a structure arranged side by side in the horizontal direction.

Due to the above-described structural differences, the S-IPS mode liquid crystal display panel and the H-IPS mode liquid crystal display panel have different rubbing directions in the process of rubbing the alignment layer.

1A to 1C are views showing a step of rubbing the alignment film of the S-IPS mode liquid crystal display panel, and FIGS. 2A to 2C are views showing a step of rubbing the H-IPS mode liquid crystal display panel.

First, referring to FIG. 1A, a color filter array substrate 70 and a thin film transistor array substrate 80 in an S-IPS mode are formed and then loaded onto a stage 62. Subsequently, after the alignment material such as polyimide is applied, the initial alignment of the liquid crystal on the color filter array substrate 70 and the thin film transistor array substrate 80 is performed by rubbing in the vertical direction using the rubbing device 60. An upper alignment layer and a lower alignment layer are formed to be aligned in the vertical direction. The rubbing device 60 has a structure in which a rubbing cloth 60b is wound around the roller 60a.

Subsequently, as shown in FIG. 1B, when the color filter array substrate 70 and the thin film transistor array substrate 80 are bonded together using the sealant 75, the liquid crystal 52 is injected, and the liquid crystal 52 is the color filter array. The substrate 70 is arranged to have an alignment film and a pretilt angle α. At the same time, the liquid crystal 52 is initially oriented in the vertical direction so that the long axis of the liquid crystal 52 is vertical as shown in FIG. 1C.

Next, referring to FIG. 2A, the color filter array substrate 170 and the thin film transistor array substrate 180 in the H-IPS mode are formed and then loaded on a stage 62. Subsequently, after an alignment material such as polyimide is applied, the liquid crystal is initially rubbed on the color filter array substrate 170 and the thin film transistor array substrate 180 by rubbing in a horizontal direction using the rubbing device 60. An upper alignment layer and a lower alignment layer are formed to be aligned in the horizontal direction.

Subsequently, as shown in FIG. 2B, when the color filter array substrate 170 and the thin film transistor array substrate 180 are bonded together using the sealant 175, the liquid crystal 152 is injected, and the liquid crystal 152 is the color filter array. The substrate 170 is arranged to have a pretilt angle α and an alignment layer of the substrate 170. At the same time, the liquid crystal 152 is initially aligned in a horizontal direction such that the long axis of the liquid crystal 52 is horizontal as shown in FIG. 2C.

The liquid crystal display panel of the conventional IPS mode has a pretilt angle α and the peaks B arranged in the liquid crystals 52 and 152 face the same direction on one alignment layer. Accordingly, as shown in FIG. 3A (only the color filter array substrate 70 is illustrated in the drawing), the color difference between the upper viewing angle and the lower viewing angle of the liquid crystal display panel appears in the S-IPS mode liquid crystal display panel. That is, at the upper viewing angle, which is the direction of the peak of the average director A of the liquid crystals or the direction B parallel to the peak B of the liquid crystal 52, the shortening of the liquid crystal 52 is observed, and the long axis of the liquid crystal 52 at the lower viewing angle. As can be seen, the actual effective refractive index (dΔn) felt by the light passing through the liquid crystal 52 depends on the viewing angle. As a result, the color difference between the upper viewing angle and the lower viewing angle of the liquid crystal display panel of the S-IPS mode appears.

In the same principle, in the H-IPS mode liquid crystal display panel, the long axes of the liquid crystals 152 are arranged in the horizontal direction, have a pretilt angle α, and the peaks B of the liquid crystals 52 and 152 arranged in the same direction on one alignment layer. Will face. Accordingly, in the H-IPS mode liquid crystal display panel, as shown in 3b (only the color filter array substrate 170 is shown in the drawing), the refractive index (effective dΔn) is changed between the left viewing angle and the right viewing angle. Color difference will appear. Accordingly, the display quality is degraded as the color difference appears not only in the S-IPS but also in the H-IPS mode liquid crystal display panel.

Accordingly, an object of the present invention is to provide an apparatus for manufacturing a liquid crystal display panel and a method for manufacturing a liquid crystal display panel using the same that can improve the display quality.

In order to achieve the above object, a liquid crystal display panel according to an embodiment of the present invention includes a color filter array substrate; A thin film transistor array substrate bonded to the color filter array substrate with liquid crystals interposed therebetween and having a pixel electrode and a common electrode forming a horizontal electric field; A first alignment layer formed on the color filter array substrate; A second alignment layer formed on the thin film transistor array substrate, wherein each of the first and second alignment layers is aligned in a first alignment region oriented in a first direction and in a second direction opposite to the first direction Divided into treated second alignment regions.

The first alignment region and the second alignment region are formed in a horizontal line shape and alternately arranged with each other.

The first alignment region and the second alignment region are formed in a vertical line shape and alternately arranged with each other.

As the liquid crystals are oriented to have a pretilt angle by the first and second alignment layers and are oriented to have the pretilt angle, the peaks of the liquid crystals face a specific direction.

The peaks of the liquid crystals corresponding to the first alignment region may face the first direction, and the peaks of the liquid crystals corresponding to the second alignment region may face the second direction.

The first direction is characterized in that the vertical direction.

The first direction is characterized in that the horizontal direction.

A method of manufacturing a liquid crystal display panel of the present invention includes the steps of forming a color filter array substrate; Forming a thin film transistor array substrate including a pixel electrode and a common electrode forming a horizontal electric field; Forming an alignment material on the color filter array substrate and the thin film transistor array substrate; First aligning the entire surface of the alignment material in a first direction; Selectively aligning the first oriented alignment material in a direction opposite to the first direction.

The first alignment region formed by the first alignment treatment and the second alignment region oriented by the second alignment treatment are alternately arranged.

An apparatus for manufacturing a liquid crystal display panel according to the present invention includes a stage on which a color filter array substrate and a thin film transistor array substrate on which an alignment material is formed are loaded; A first rubbing device for orienting the first region of the alignment material in a first direction; And a second rubbing device for orienting the second region of the alignment material in a second direction opposite to the first direction, wherein the second rubbing device has a shape in which a rubbing cloth of a line shape is wound around a roller. do.

The second region of the alignment material is a region oriented by a rubbing cloth in the form of a line of the second rubbing device.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 4 to 6E.

4 is a cross-sectional view illustrating a liquid crystal display panel in IPS mode. 4 shows the same structure regardless of the S-IPS and H-IPS modes.

Referring to FIG. 4, the liquid crystal display panel 290 in the IPS mode may include a black matrix 204, a color filter 206, an overcoat layer 207, a spacer 213, and an upper portion sequentially formed on the upper substrate 202. A color filter array substrate 270 composed of an alignment layer 208, a thin film transistor 15 formed on the lower substrate 232, a common electrode 218, a pixel electrode 216, and a lower alignment layer 238. The thin film transistor array substrate 280, and the liquid crystal 252 is injected into the interior space between the color filter array substrate 270 and the thin film transistor array substrate 280.

In the color filter array substrate 270, the black matrix 24 is formed to overlap the region of the thin film transistor 215 of the lower substrate 22 and the region of gate lines and data lines, not shown, and the color filter 226. Partitions the cell region to be formed. The black matrix 204 prevents light leakage and absorbs external light to enhance contrast. The color filter 206 is formed in the cell region separated by the black matrix 204. The color filter 206 is formed for each of R, G and B to implement R, G, and B colors. The overcoat layer 207 is formed to cover the color filter 206 to planarize the upper substrate 202. The spacer 213 serves to maintain a cell gap between the upper substrate 202 and the lower substrate 232.

In the thin film transistor array substrate 280, the thin film transistor 215 includes a gate electrode 209 formed on the lower substrate 232 together with a gate line (not shown), the gate electrode 209, and a gate insulating film ( The semiconductor layers 214 and 247 overlap each other with the 244 interposed therebetween, and the source / drain electrodes 240 and 242 formed together with the data lines (not shown) with the semiconductor layers 214 and 247 interposed therebetween. The thin film transistor 215 supplies a pixel signal from the data line to the pixel electrode 216 in response to a scan signal from the gate line. The pixel electrode 216 is a transparent conductive material having a high light transmittance and contacts the drain electrode 242 of the thin film transistor 215 with the passivation layer 250 therebetween. The common electrode 218 is formed in a stripe shape so as to alternate with the pixel electrode 216. The common electrode 218 supplies a common voltage which is a reference when driving the liquid crystal. The liquid crystal rotates with respect to the horizontal direction by the horizontal electric field between the common voltage and the pixel voltage supplied to the pixel electrode 216.

The upper and lower alignment layers 208 and 238 for liquid crystal alignment are formed by applying an alignment material such as polyimide and then performing a rubbing process.

In the present invention, the upper and lower alignment layers 208 and 238 align the initial alignment of the liquid crystals 152 horizontally (in the H-IPS mode) or vertically (in the S-IPS mode) as in the related art. The pretilt angle? Formed between the major axis (or director) and the alignment film is formed.

However, each of the upper and lower alignment layers 208 and 238 has a pretilt angle α and two regions in which the peak of the director A of the aligned liquid crystals 252 or the direction of the peak B of the liquid crystal is opposite to each other. It is oriented to separate it.

This will be described in more detail with reference to FIGS. 5 and 6 as follows.

First, FIG. 5 illustrates a state in which liquid crystals are aligned on upper and lower alignment layers 208 and 238 in the H-IPS mode. The upper and lower alignment layers 208 and 238 are alternately formed with the first alignment region P1 and the second alignment region P2 in a horizontal line shape, respectively. For example, the first alignment region P1 is a region rubbed in a left to right direction, and the second alignment region P2 is a region rubbed in a right to left direction. Accordingly, the liquid crystals positioned on one alignment layer are all aligned in the horizontal direction, but the liquid crystals 152 oriented by the first alignment region P1 are aligned to have a predetermined pretilt angle α and at the same time the liquid crystal 152 All of the peaks B face the right side, and the peaks B of the liquid crystals 152 oriented by the second alignment region P2 all face the left side. Here, the peak B of the liquid crystal 152 means the uppermost end of the liquid crystal 252 positioned relatively far from the surface of the alignment layer as the pretilt angle α is formed.

As a result, the average value of the effective refractive index n at the left viewing angle and the right viewing angle becomes equal to each other, so that color difference does not appear.

6 illustrates a state in which liquid crystals are aligned on upper and lower alignment layers 208 and 238 in the S-IPS mode.

The upper and lower alignment layers 208 and 238 are alternately formed with the first alignment region P1 and the second alignment region P2 in the form of vertical lines, respectively. For example, the first alignment region P1 is a region rubbed downward from the top, and the second alignment region P2 is a region rubbed downward from the top. Accordingly, the liquid crystals 152 positioned on one alignment layer are all aligned in the vertical direction, but the liquid crystals 152 aligned by the first alignment region P1 are aligned to have a predetermined pretilt angle α and at the same time The peaks B of the 152s all face downward, and the peaks B of the liquid crystals 152 oriented by the second alignment region P2 all face upward.

As a result, the average values of the effective refractive indices (effective dΔn) at the upper viewing angle and the lower viewing angle are equal to each other, so that color difference does not appear.

That is, the first and second alignment regions P1 such that the directions indicated by the peak B of the liquid crystal 152 or the peak B of the director are opposite to each other in one alignment layer as shown in FIGS. 5 and 6. , P2). As a result, the refractive index value between the upper, lower, and left and right sides of the liquid crystal display panel can be made the same, thereby improving display quality such that color difference does not appear.

Hereinafter, an apparatus and a method for manufacturing an alignment layer that may be divided into first and second alignment regions P1 and P2 will be described.

7A and 7B illustrate an apparatus and a rubbing process for rubbing an alignment layer of an S-IPS mode liquid crystal display panel.

First, a color filter array substrate including a black matrix, a color filter, and the like is formed, and a thin film transistor array substrate including a thin film transistor, a gate line and a data line, and a pixel electrode is formed by a separate process.

Referring to FIG. 7A, after the color filter array substrate 270 and the thin film transistor array substrate 280 are loaded onto the stage 62, an alignment material such as polyimide is coated. Here, the alignment material may be applied by a separate process and then loaded on the stage 162.

Subsequently, the color filter array substrate 70 is rubbed (hereinafter referred to as a “first rubbing process”) from the top to the bottom (hereinafter referred to as a “first direction”) using the first rubbing device 160. And an upper alignment layer and a lower alignment layer are formed on the thin film transistor array substrate 80 so that the major axis of the liquid crystal is vertical.

Next, referring to FIG. 7B, the second rubbing is performed in the upward direction (hereinafter, referred to as a “second direction”) using the second rubbing device 165 having an uneven shape. Here, since the rubbing cloth 165b is wound around the entire roller 165a, the rubbing cloth 165b comes into contact with the entire alignment material. On the contrary, the uneven second rubbing device 165 is a form in which the rubbing cloth 165b of the line shape of the roller 165a is wound, and only the alignment material contacted by the rubbing cloth 165b of the line type is selectively made. It is rubbed in two directions.

Accordingly, the second alignment region P2, which is a region rubbed by the line-like rubbing cloth 165b on the surfaces of the upper and lower alignment layers 208, 238, and the first non-contact region, which is in contact with the line-type rubbing cloth 165b. It can be divided into the alignment region (P1). The first alignment region P1 is also a region rubbed by only the first rubbing device 60.

Accordingly, each of the upper and lower alignment layers 208 and 238 may be divided into a first alignment region P1 and a second alignment region P1 as shown in FIG. 6.

Thereafter, the liquid crystal is injected after the color filter array substrate and the thin film transistor array substrate are bonded together.

Accordingly, as shown in FIG. 6, the liquid crystals 252 of the region corresponding to the first alignment region P1 are aligned so that their peak B faces downward, and the second alignment region P2 is aligned. The liquid crystals 252 in the region corresponding to) are oriented such that their peaks B face upwards.

8A and 8B illustrate an apparatus and a rubbing process for rubbing an alignment layer of an H-IPS mode liquid crystal display panel.

First, a color filter array substrate including a black matrix, a color filter, and the like is formed, and a thin film transistor array substrate including a thin film transistor, a gate line and a data line, and a pixel electrode is formed by a separate process.

Referring to FIG. 8A, after the color filter array substrate 270 and the thin film transistor array substrate 280 are loaded onto the stage 62, an alignment material such as polyimide is coated. Here, the alignment material may be applied by a separate process and then loaded on the stage 162.

Subsequently, the color filter array substrate 70 is subjected to rubbing (hereinafter referred to as "first rubbing process") from the left to the right (hereinafter referred to as "first direction") using the first rubbing device 160. And an upper alignment layer and a lower alignment layer are formed on the thin film transistor array substrate 80 so that the major axis of the liquid crystal is horizontal.

Next, referring to FIG. 8B, the second rubbing is performed from the right side to the left side (hereinafter referred to as “second direction”) using the second rubbing device 165 having an uneven shape. Here, in the first rubbing device 160 and the second rubbing device 165, the first rubbing device 160 and the second rubbing device 165 shown in FIGS. 7A and 7B may be used in the same manner.

Accordingly, the second alignment region P2, which is a region rubbed by the line-like rubbing cloth 165b on the surfaces of the upper and lower alignment layers 208 and 238, and a region which is not in contact with the line-like rubbing cloth 165b, are formed. It can be divided into one alignment region (P1). The first alignment region P1 is also a region rubbed by only the first rubbing device 60.

Accordingly, each of the upper and lower alignment layers 208 and 238 may be divided into a first alignment region P1 and a second alignment region P1 as shown in FIG. 5.

Thereafter, the liquid crystal is injected after the color filter array substrate and the thin film transistor array substrate are bonded together.

Accordingly, as shown in FIG. 5, the liquid crystals 252 of the region corresponding to the first alignment region P1 have a pretilt angle and their peaks B are oriented in the right direction. The liquid crystals 252 in the region corresponding to the two alignment regions P2 are aligned such that their peaks B face the left direction.

As described above, the apparatus for manufacturing a liquid crystal display panel according to an exemplary embodiment of the present invention, the liquid crystal display panel using the same, and a method for manufacturing the liquid crystal display panel using the same are opposite to each other in the direction indicated by the peak of the liquid crystal or the peak of the liquid crystal director. It is divided into a first and a second alignment region to be a. As a result, the refractive index values of the upper, lower, and left and right sides of the liquid crystal display panel can be made equal. As a result, it is possible to improve display quality such that color difference does not appear between the top, bottom, left and right sides of the liquid crystal display panel.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (13)

A color filter array substrate; A thin film transistor array substrate bonded to the color filter array substrate with liquid crystals interposed therebetween and having a pixel electrode and a common electrode forming a horizontal electric field; A first alignment layer formed on the color filter array substrate; A second alignment layer formed on the thin film transistor array substrate, Each of the first and second alignment layers, And first alignment regions oriented in a first direction and second alignment regions oriented in a second direction opposite to the first direction. The method of claim 1, And the first alignment region and the second alignment region are formed in a horizontal line shape and alternately arranged with each other. The method of claim 1, And the first alignment region and the second alignment region are formed in a vertical line shape and alternately arranged with each other. The method of claim 1, And the liquid crystals are oriented to have a pretilt angle by the first and second alignment layers, and the peaks of the liquid crystals are directed in a specific direction as the liquid crystals are oriented to have the pretilt angle. The method of claim 4, wherein A peak of liquid crystals corresponding to a first alignment region faces the first direction, and a peak of liquid crystals corresponding to the second alignment region faces the second direction. The method of claim 5, wherein And the first direction is a vertical direction. The method of claim 5, wherein And the first direction is a horizontal direction. Forming a color filter array substrate; Forming a thin film transistor array substrate including a pixel electrode and a common electrode forming a horizontal electric field; Forming an alignment material on the color filter array substrate and the thin film transistor array substrate; First aligning the entire surface of the alignment material in a first direction; And selectively performing a second alignment treatment on the first alignment-oriented alignment material in a direction opposite to the first direction. The method of claim 8, And the first alignment region formed by the first alignment treatment and the second alignment region oriented by the second alignment treatment are alternately arranged. The method of claim 8, And the first direction is a vertical direction. The method of claim 8, The first direction is a horizontal direction manufacturing method of the liquid crystal display panel, characterized in that. A stage on which the color filter array substrate and the thin film transistor array substrate on which the alignment material is formed are loaded; A first rubbing device for orienting the first region of the alignment material in a first direction; A second rubbing device for orienting the second region of the alignment material in a second direction opposite to the first direction, The second rubbing device is a manufacturing apparatus of a liquid crystal display panel, characterized in that the line-shaped rubbing cloth wound around the roller. The method of claim 12, And the second area of the alignment material is an area processed by a rubbing cloth in the form of a line of the second rubbing device.

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