KR20050061192A - Rubbing method of liquid crystal display device - Google Patents

Abstract

The present invention relates to a rubbing method of a liquid crystal display device capable of shortening the rubbing process time of the liquid crystal display device to improve productivity, and preparing first and second substrates, and preparing the first and second substrates on the first and second substrates. Applying an alignment layer, arranging the first and second substrates so that the alignment layers face each other at a predetermined distance, placing a rubbing roll on one side between the two substrates, and then moving the rubbing roll to the other side of the substrate. It provides a rubbing method for a liquid crystal display device comprising the step of moving.

Description

Rubbing method of liquid crystal display device {RUBBING METHOD OF LIQUID CRYSTAL DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a rubbing method of a liquid crystal display device capable of improving productivity by rubbing two substrates simultaneously through one rubbing process.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, and notebook computers, there is a growing demand for flat panel display devices for light and thin applications. Such flat panel displays are being actively researched, such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), FED (Field Emission Display), VFD (Vacuum Fluorescent Display), but mass production technology, ease of driving means, Liquid crystal display devices (LCDs) are in the spotlight for reasons of implementation.

1 schematically illustrates a cross section of a general liquid crystal display device. As shown in the figure, the liquid crystal display device 1 is composed of a lower substrate 5 and an upper substrate 3 and a liquid crystal layer 7 formed between the lower substrate 5 and the upper substrate 3. . Although the lower substrate 5 is a driving element array substrate, although not shown in the drawing, a plurality of pixels are formed on the lower substrate 5, and each pixel is driven such as a thin film transistor. An element is formed. The upper substrate 3 is a color filter substrate, and a color filter layer for realizing color is formed. In addition, a pixel electrode and a common electrode are formed on the lower substrate 5 and the upper substrate 3, respectively, and an alignment film for aligning liquid crystal molecules of the liquid crystal layer 7 is coated.

The lower substrate 5 and the upper substrate 3 are bonded by a sealing material 9, and a liquid crystal layer 7 is formed therebetween, and is driven by a driving element formed on the lower substrate 5. Information is displayed by controlling the amount of light passing through the liquid crystal layer by driving the liquid crystal molecules.

The manufacturing process of the liquid crystal display device can be largely divided into a driving element array substrate process of forming a driving element on the lower substrate 5, a color filter substrate process of forming a color filter on the upper substrate 3, and a cell process. However, the process of the liquid crystal display will be described with reference to FIG. 2.

First, a plurality of gate lines and data lines arranged on the lower substrate 5 to define a pixel region are formed by a driving element array process, and the gate line and the data are formed in each of the pixel regions. A thin film transistor which is a driving element connected to the line is formed (S101). In addition, the pixel electrode is connected to the thin film transistor through the driving element array process to drive the liquid crystal layer as a signal is applied through the thin film transistor.

In addition, the upper substrate 3 is formed with a color filter layer and a common electrode of R, G, B to implement the color by the color filter process (S104).

Subsequently, an alignment layer is applied to the upper substrate 3 and the lower substrate 5, respectively, and then the alignment control force or surface fixing force (ie, the liquid crystal molecules of the liquid crystal layer formed between the upper substrate 3 and the lower substrate 5). In order to provide a pretilt angle and an orientation direction, the alignment layer is rubbed (S102 and S105). Subsequently, a spacer is disposed on the lower substrate 5 to maintain a constant cell gap, and a sealing material is applied to an outer portion of the upper substrate 3. Then, the lower substrate 5 and the upper substrate are dispersed. Pressure is applied to (3), and it adheres (S103, S106, S107). On the other hand, the lower substrate 5 and the upper substrate 3 is made of a large area glass substrate. In other words, a plurality of panel regions are formed on the glass substrate of a large area, and a TFT and a color filter layer serving as driving elements are formed in each of the panel regions, so that the glass substrates are cut to produce a single liquid crystal panel. Must be processed (S108). Thereafter, the liquid crystal is injected into the liquid crystal panel processed as described above through the liquid crystal inlet, and the liquid crystal inlet is encapsulated to form a liquid crystal layer. Then, the liquid crystal display is manufactured by inspecting each liquid crystal panel (S109 and S110). .

The liquid crystal display device fabricated through the above process uses the electro-optic effect of the liquid crystal. The electro-optic effect is determined by the anisotropy of the liquid crystal itself and the molecular arrangement state of the liquid crystal. The rubbing process has a great influence on the stabilization of the display quality of the liquid crystal display device.

In the rubbing process, as shown in FIG. 3, after uniformly applying the alignment layer on the substrate 130 on the stage 150, the roller 120 having the rubbing cloth wound by passing the spage 150 passes the alignment layer. It is a process of forming a fine groove on an oriented film by making it so. At this time, since the alignment layer rubbing is performed by the movement of the page 150, it is possible to rub only one substrate during one rubbing. Therefore, the rubbing process time becomes long, which is a factor of lowering the production efficiency.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display device capable of shortening the process time and improving the production efficiency by rubbing two substrates at the same time. To provide a rubbing method.

In addition, the objects and features of the present invention will be described in detail in the configuration and claims of the invention below.

The present invention for achieving the above object is the steps of preparing a first and a second substrate, applying an alignment layer on the first and second substrate, and the first and second substrate a constant distance And arranging the alignment layers so as to face each other, and placing the rubbing roll on one side between the two substrates, and then moving the rubbing roll to the other side.

In this case, the first and second substrates are thin film transistor array substrates, defining a pixel region in a matrix form on the transparent first and second substrates, forming a thin film transistor in each pixel region, The pixel electrode is connected to the thin film transistor and is formed by forming a pixel electrode formed on an entire surface of each pixel region.

In addition, the first and second substrates may be color filter substrates. In the case of the color filter substrates, the preparing of the first and second substrates may include a black matrix and a color filter on the transparent first and second substrates. And forming a common electrode on the color filter.

That is, the first and second substrates may be thin film transistor substrates or color filter substrates in a twisted nematic liquid crystal display device. Therefore, in the general TN type liquid crystal display device, since the rubbing direction of the alignment layer has a direction substantially diagonal to the substrate, the rubbing roll has a predetermined angle with respect to the long side of the substrate when the rubbing roll moves from one side to the other side between the two substrates. In addition, since the rubbing directions of the thin film transistor array substrate and the color filter substrate are opposite to each other and constitute 90 °, when the rubbing roll moves in a diagonal direction, the rubbing rolls move in opposite directions.

Meanwhile, the first and second substrates may be thin film transistor array substrates of an in plane switching (IPS) type liquid crystal display device, and the method may include defining a pixel region in a matrix form on the transparent substrate, and in each of the pixel regions. Forming a thin film transistor and connecting the thin film transistor, and forming a common electrode and a pixel electrode for generating a horizontal electric field in each pixel region.

Further, the first and second substrates may be color filter substrates of an IPS (in plane switching) type liquid crystal display device, which includes forming a black matrix on the transparent substrate and forming a color filter on the black matrix. It is produced through the steps.

In this case, when the rubbing roll moves from one side to the other side between the two substrates, the rubbing roll has a predetermined angle with respect to the long side of the substrate.

The first and second substrates may be thin film transistor array substrates or color filter substrates of S-IPS type liquid crystal display devices in which a common electrode and a pixel electrode are arranged in a zigzag structure. In this case, in the case of a thin film transistor array substrate, this method includes defining a pixel region in a matrix form on a transparent substrate, forming a thin film transistor in each pixel region, and connecting the thin film transistor to each pixel region. A common electrode and a pixel electrode having a zigzag structure for generating an electric field are formed, and the color filter substrate is formed by forming a black matrix on a transparent substrate and a color filter on the black matrix. It is produced through the step of forming.

As described above, the S-IPS type liquid crystal display device having a zigzag-folded common electrode and a pixel electrode moves in a direction parallel to the long side or the short side of the substrate when the rubbing roll moves from one side to the other side between the two substrates. Done.

In addition, the rubbing method of the liquid crystal display device according to the present invention comprises the steps of preparing a thin film transistor array substrate, preparing a color filter substrate, the thin film transistor array substrate and the color filter substrate so that the alignment film is facing each other at a constant distance. And placing the rubbing roll on one side between the two substrates, and then moving the rubbing roll to the other side.

The preparing of the thin film transistor array substrate may include defining a pixel region in a matrix form on the transparent first substrate, forming a thin film transistor in each pixel region, and connecting the thin film transistor, Generating a horizontal electric field in the pixel region, and forming a common electrode and a pixel electrode having a zigzag structure, the forming of the color filter substrate is a step of forming a black matrix on the transparent second substrate And forming a color filter on the black matrix. In addition, when the rubbing roll moves from one side to the other side between the two substrates, the rubbing roll has a direction parallel to the long side or short side of the substrate.

Further, in the case of the S-IPS type liquid crystal display device, since the rubbing directions of the thin film transistor array substrate and the color filter substrate are the same, it is possible to rub different substrates at the same time. The rubbing roll is moved in the direction.

However, the general IPS type and TN type liquid crystal display devices cannot rub two substrates at the same time because the rubbing directions of the thin film transistor array substrate and the color filter substrate are not the same, but two thin film transistor array substrates or color filter substrates cannot be rubbed at the same time. It is possible to rub at the same time. That is, the thin film transistor array substrate or the color filter substrates are disposed so that the surfaces on which the alignment films are applied face each other, and then the rubbing roll is rotated therebetween, and the rubbing roll is moved from one side of the substrate to the other side, that is, in a diagonal direction. In the process, two identical substrates can be rubbed simultaneously.

As described above, the present invention can reduce the rubbing process time by rubbing the thin film transistor array substrate and the color filter substrate at the same time according to the manner in which the liquid crystal is driven, thereby further improving the production efficiency.

Hereinafter, a method of manufacturing a liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 shows the rubbing direction of the liquid crystal display of the TN method (twisted nematic mode) formed by the rubbing method of the present invention, the solid line represents the optical axis direction of the polarizing plate, the dotted line represents the rubbing direction. And ① and ② indicate the starting point of rubbing, and ③ and ④ indicate the end point of rubbing. Therefore, the rubbing direction of the upper substrate is made of ① → ③, made of ② → ④.

As shown in the drawing, in the TN type liquid crystal display device 200, a pixel electrode (not shown) is formed on the first substrate 210, and a common electrode (not shown) is formed on the second substrate 220. When an electric field is applied between them, the liquid crystal 230 formed between the first substrate 210 and the second substrate 220 rotates to pass or block light to display characters or images. In addition, first and second polarizing plates 215 and 225 are provided on the outer peripheries of the first and second substrates 210 and 220, and polarization directions of the polarizing plates 215 and 225 correspond to rubbing directions. That is, the polarization direction of the first polarizing plate 215 is the same as the rubbing direction of the first substrate 210, and the polarization direction of the second polarizing plate 225 is the same as the rubbing direction of the second substrate 220. The living direction has a diagonal direction with respect to the substrates 210 and 220. The polarization directions of the first and second polarizing plates 215 and 225 are perpendicular to each other. At this time, the rubbing direction is the same substrate is made by one rubbing process, a detailed description of the rubbing method will be described with reference to the following drawings.

In the TN type liquid crystal display device configured as described above, when no voltage is applied, the liquid crystal 230 is arranged along the rubbing directions of the first and second substrates 210 and 220, and the upper liquid crystal and the lower liquid crystal are arranged in opposite directions. The upper and lower liquid crystals are in a twisted state. Therefore, the light incident from the backlight is transmitted through the second polarizing plate 225, the liquid crystal layer 230, and the first polarizing plate 215 as it is, and displays white on the screen.

On the other hand, when a voltage is applied, an electric field is formed between the pixel electrode and the common electrode, and the liquid crystal 230 is driven along the electric field direction. At this time, the liquid crystal 230 adjusts the amount of light transmitted according to the intensity of the voltage, and when the liquid crystal is arranged in the vertical direction, the liquid crystal 230 shows a black screen.

As described above, the TN liquid crystal display device has a rubbing direction formed in a diagonal direction with respect to the substrate, and the directions of the first and second substrates should be formed perpendicular to each other. Should be.

5 and 6 illustrate a rubbing method of the TN type liquid crystal display device configured as described above, FIG. 5 shows a rubbing method of a thin film transistor array substrate, and FIG. 6 shows a rubbing method of a color filter substrate, respectively. will be. In addition, reference numerals A to N denote unit panels of the liquid crystal display device for each position.

First, as shown in FIG. 5, first and second thin film transistor array substrates 220a and 220b coated with an alignment layer are prepared, and then the first and second thin film transistor array substrates face each other with the alignment layer coated surface. Place 220a and 220b. In this case, the first and second thin film transistor array substrates 220a and 220b may include a gate line and a data line defining a pixel area in a matrix form on a transparent substrate, and a thin film transistor in each pixel area. Next, a pixel electrode electrically connected to the thin film transistor is formed over the entire pixel region.

In addition, when the first and second thin film transistor array substrates 220a and 220b are disposed at regular intervals, the first and second thin film transistor array substrates 220a and 220b should be uniformly spaced over the entire substrate. As such, when the first and second thin film transistor array substrates 220a and 220b coated with the alignment layer are disposed at uniform intervals, a rubbing roll having a predetermined angle with a short side or long side of the substrate in the first corner region ⓛ ( After positioning 250, the rubbing is performed by rotating the rubbing roll 252 in the diagonal direction, that is, the third corner region ③. At this time, depending on the moving direction of the rubbing roll 250, a constant valley is formed on the alignment films of the first and second thin film transistor array substrates 220a and 220b to determine the initial alignment direction of the liquid crystal.

In addition, the rubbing process of the color filter substrate is performed in the same manner. However, the rubbing roll should be moved so that the thin film transistor array substrate and the rubbing direction are orthogonal to each other due to the characteristics of the TN type liquid crystal display device. That is, as shown in Figure 6, after preparing the first and second color filter substrate (210a, 210b), the rubbing roll 250 to form a predetermined angle with the short side or long side of the substrate in the second corner region (②) After positioning, by moving the rubbing roll 250 in the diagonal direction, that is, the fourth corner region (4), rubbing is performed. At this time, according to the moving direction of the rubbing roll 250, a constant valley for determining the initial alignment direction of the liquid crystal is formed in the alignment film of the first and second color filter substrate (210a, 210b). In addition, the first and second color filter substrates 210a and 210b are manufactured by forming a black matrix and a color filter on a transparent substrate and then forming a common electrode on the color filter.

As shown in FIGS. 5 and 6, the rubbing method of the TN type liquid crystal display device according to the present invention is arranged on the same substrate, that is, the thin film transistor array substrate or the color filter substrate so that the alignment layer to face each other, and then between the rubbing rolls While moving while rotating, rubbing is performed in the moving direction, that is, diagonal direction. Therefore, the rubbing method of the present invention has the advantage that the rubbing process time can be reduced by half because the rubbing method of the present invention can rub two substrates at the same time by moving the rubbing roll once.

The present invention can be equally applied to the IPS mode, and even in this case, the same substrates can rub two substrates at the same time. However, in the case of the IPS type liquid crystal display device, since the angle formed between the color filter substrate and the thin film transistor array substrate is smaller than TN, the angle formed by the rubbing roll with respect to the substrate must be adjusted to suit the designed rubbing direction.

That is, as shown in FIG. 7, the IPS type liquid crystal display device 300 includes a pixel electrode and a common electrode (not shown) formed on the second substrate 320 on which the thin film transistor is formed. The first and second polarizing plates 315 and 325 are provided outside the 310 and the second substrate 320. The rubbing directions of the first and second substrates 310 and 320 are the same, and the polarization direction of the second polarizing plate 325 is the same as the rubbing direction. The polarization direction of the first polarizer 315 is perpendicular to the polarization direction of the second polarizer 325.

In the IPS type liquid crystal display device configured as described above, when no electric field is applied, the liquid crystals are arranged along the rubbing direction, and the light incident from the backlight may pass through the second polarizing plate 325 and the liquid crystal layer 330. The black screen is blocked by the first polarizer 315.

On the other hand, when a voltage is applied, a horizontal electric field is formed between the pixel electrode and the common electrode, and the liquid crystal 330 is driven along the electric field direction. When the driving direction of the liquid crystal is 45 ° to the rubbing direction, the transmittance is maximum. Becomes At this time, the rubbing direction is formed at an angle with respect to the electrode direction.

Also in this case, since the rubbing directions of the color filter substrate and the thin film transistor array substrate are opposite to each other, the same substrates can be rubbed.

However, among the IPS type liquid crystal display devices, a structure in which the pixel electrode and the common electrode are bent in a zigzag shape to improve the viewing angle and color characteristics, that is, the S-IPS (super in plane switching) liquid crystal display device has a rubbing direction. Since the color filter substrate and the thin film transistor array substrate are the same as each other, the color filter substrate and the thin film transistor array substrate can be rubbed simultaneously.

That is, as illustrated in FIG. 8, the thin film transistor array substrate 420 of the super-plane switching (S-IPS) type liquid crystal display device having the bent structure of the pixel electrode 407 and the common electrode 406 is formed of a pixel. The rubbing direction is made parallel to the longitudinal direction, and although not shown in the drawing, the rubbing direction of the color filter substrate is also parallel to the thin film transistor and has the same direction.

Accordingly, super in plane switching (S-IPS) can perform rubbing between identical substrates or different substrates (ie, color filter substrate and thin film transistor array substrate).

That is, as shown in FIG. 9, in the S-IPS type liquid crystal display device, after the alignment layer is applied to the color filter substrate 410 and the thin film transistor array substrate 420, they are fixed so as to face each other. After arranging at intervals, the rubbing roll 450 is positioned to be parallel to the short side direction or the long side direction of the substrate, and then the rubbing roll 450 is rotated and moved to advance the rubbing.

As described above, the present invention provides a rubbing method for a liquid crystal display device by reducing the process time by rubbing two substrates at the same time. That is, as described in the detailed description, the present invention is to rub two substrates at the same time as the rubbing roll rotates while the rubbing roll is in contact with the two substrates. As such, by rubbing the two substrates at the same time, the process time can be reduced, and productivity can be improved by reducing the process time. In addition, according to the present invention, the liquid crystal is driven, that is, TN or IPS (S-IPS), by adjusting the angle between the substrate and the rubbing roll can be rubbed appropriately for the driving method, rubbing the same substrate at the same time Alternatively, another substrate, that is, a color filter substrate and a thin film transistor array substrate may be rubbed at the same time.

As described above, according to the present invention, by arranging two substrates to face each other at regular intervals, and then moving the rubbing roll therebetween, rubbing of the two substrates can be performed simultaneously in one rubbing process. In this way, by rubbing the two substrates at the same time, the rubbing process time can be reduced by almost half, thereby further improving the production efficiency.

1 is a cross-sectional view of a general liquid crystal display device.

2 is a flowchart illustrating a manufacturing process of a general liquid crystal display device.

3 is a view showing a conventional rubbing method.

4 is a view showing a rubbing direction of a TN type liquid crystal display device.

5 is a view showing a color filter substrate rubbing method of a TN type liquid crystal display device according to the present invention;

6 is a view showing a rubbing method of a thin film transistor array substrate of a TN type liquid crystal display device according to the present invention;

7 is a view showing a rubbing direction of an IPS type liquid crystal display device.

8 is a view briefly showing a thin film transistor array substrate and its rubbing direction of an S-IPS type liquid crystal display device.

9 is a view showing a rubbing method of the S-IPS type liquid crystal display device according to the present invention.

*** Explanation of symbols for main parts of drawing ***

210a: first color filter substrate 210b: second color filter substrate

220a: first thin film transistor array substrate

220b: second thin film transistor array substrate

310,410: color filter substrate

320,420: thin film transistor array substrate

250,450: rubbing roll

Claims (17)

Preparing first and second substrates; Applying an alignment layer on the first and second substrates; Arranging the first and second substrates so that the alignment layers face each other at a predetermined distance; And And positioning the rubbing roll on one side between the two substrates, and then moving the rubbing roll to the other side of the substrate. The method of claim 1, wherein the preparing of the first and second substrates comprises: Defining a pixel area in a matrix form on the transparent first and second substrates; Forming a thin film transistor in each pixel region; And And forming a pixel electrode connected to the thin film transistor and formed on an entire surface of each pixel region. The method of claim 1, wherein the preparing of the first and second substrates comprises: Forming a black matrix and a color filter on the transparent first and second substrates; And Forming a common electrode on the color filter. The rubbing method according to claim 2 or 3, wherein the rubbing roll has a predetermined angle with respect to the long side of the substrate when the rubbing roll moves from one side to the other side between the two substrates. The rubbing method of claim 1, wherein the rubbing roll rotates when the rubbing roll moves from one side to the other side between the two substrates. The method of claim 1, wherein the preparing of the first and second substrates comprises: Defining a pixel region in a matrix form on the transparent substrate; Forming a thin film transistor in each pixel region; And And forming a common electrode and a pixel electrode connected to the thin film transistor to generate a horizontal electric field in each pixel region. The method of claim 1, wherein the preparing of the first and second substrates comprises: Forming a black matrix on the transparent substrate; And Forming a color filter on the black matrix. The rubbing method according to claim 6 or 7, wherein the rubbing roll has a predetermined angle with respect to the long side of the substrate when the rubbing roll moves from one side to the other side between the two substrates. The method of claim 1, wherein the preparing of the first and second substrates comprises: Defining a pixel region in a matrix form on the transparent substrate; Forming a thin film transistor in each pixel region; And And forming a common electrode and a pixel electrode having a zigzag structure connected to the thin film transistor and generating a horizontal electric field in each pixel region. 10. The rubbing method according to claim 7 or 9, wherein the rubbing roll has a direction parallel to the long side of the substrate when the rubbing roll moves from one side to the other side between the two substrates. 10. The rubbing method according to claim 7 or 9, wherein the rubbing roll has a direction parallel to a short side of the substrate when the rubbing roll moves from one side to the other side between the two substrates. Preparing a thin film transistor array substrate; Preparing a color filter substrate; Disposing the thin film transistor array substrate and the color filter substrate so that the alignment layer faces each other at a predetermined distance; And And positioning the rubbing roll on one side between the two substrates, and then moving the rubbing roll to the other side. The method of claim 12, wherein preparing the thin film transistor array substrate comprises: Defining a pixel area in the form of a matrix on the transparent first substrate; Forming a thin film transistor in each pixel region; And Connecting to the thin film transistor, generating a horizontal electric field in each pixel region, and forming a common electrode and a pixel electrode having a zigzag structure. The method of claim 12, wherein preparing the color filter substrate comprises: Forming a black matrix on the transparent second substrate; And Forming a color filter on the black matrix. The rubbing method of claim 13 or 14, wherein the rubbing roll has a direction parallel to the long side of the substrate when the rubbing roll moves from one side to the other side between the two substrates. 15. The rubbing method according to claim 13 or 14, wherein the rubbing roll has a direction parallel to a short side of the substrate when the rubbing roll moves from one side to the other side between the two substrates. The rubbing method of claim 12, wherein the rubbing roll rotates when the rubbing roll moves from one side to the other side between the two substrates.