KR100820105B1 - A means of rubbing a big size substrate - Google Patents

Abstract

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 means for performing a rubbing process on a large area substrate constituting a large area liquid crystal panel.

A plurality of rubbing cloths cut in the same size are wound in one direction on a rubbing roller having the same length in the transverse direction of the large area substrate.

The cut rubbing cloth is cut according to the trapping of the rubbing cloth.

By using a rubbing roller in which the plurality of rubbing cloths are wound, a rubbing process may be performed on a large area substrate without rubbing defects.

Description

A rubbing means of a large area substrate             

1 is a view schematically showing a liquid crystal display device;

2 is a flowchart illustrating a procedure of manufacturing a liquid crystal display device;

3 is a view showing a rubbing means and a substrate according to the prior art,

4 is a view showing a rubbing cloth,

5 is a view showing a rubbing cloth according to the present invention,

Figure 6 is a view showing a rubbing roller wound rubbing cloth according to the present invention,

7 is a view showing a rubbing means according to the present invention and a large area substrate in which a rubbing process is performed by the rubbing means.

<Brief description of the main parts of the drawing>

102: cutting the rubbing cloth 104: rubbing roller

200: substrate 202: cutting line

204: rubbing means 206: alignment film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to rubbing means for rubbing a large area substrate constituting a large area liquid crystal panel.

In general, the driving principle of the liquid crystal display device uses the optical anisotropy and polarization of the liquid crystal. Since the liquid crystal is thin and long in structure, the liquid crystal has directivity in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal.

Accordingly, if the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light is refracted in the molecular arrangement direction of the liquid crystal by optical anisotropy to express an image.

The liquid crystal display includes a color filter substrate (upper substrate) on which a common electrode is formed, an array substrate (lower substrate) on which a pixel electrode is formed, and a liquid crystal filled between upper and lower substrates. The liquid crystal is driven by an electric field applied up and down by the pixel electrode, so that the characteristics such as transmittance and aperture ratio are excellent.

Currently, an active matrix liquid crystal display (AM-LCD: Active Matrix LCD) in which a thin film transistor and pixel electrodes connected to the thin film transistor are arranged in a matrix manner is attracting most attention.

Hereinafter, a configuration of the liquid crystal display device will be described with reference to FIG. 1.

As shown, a general color liquid crystal display device 11 includes a color filter 7 including a black matrix 6 and a sub color filter (red, green, blue) 8, and a common electrode transparent on the color filter. And an upper substrate 5 having an 18 formed thereon, and a lower substrate 22 having an array wiring including a pixel region P and a pixel electrode 17 formed on the pixel region and a switching element T. The liquid crystal layer 14 is filled between the upper substrate 5 and the lower substrate 22.

The lower substrate 22 is also referred to as an array substrate, and the thin film transistor T, which is a switching element, is positioned in a matrix type, and the gate wiring 13 and the data wiring 15 passing through the plurality of thin film transistors cross each other. Is formed.

The pixel area P is an area defined by the gate line 13 and the data line 15 intersecting each other. The pixel electrode 17 formed on the pixel region P uses a transparent conductive metal having relatively high light transmittance, such as indium-tin-oxide (ITO).

In the liquid crystal display, the liquid crystal layer 14 positioned on the pixel electrode 17 is aligned by a signal applied from the thin film transistor T, and the liquid crystal layer 14 is disposed according to the degree of alignment of the liquid crystal layer. The image can be expressed by controlling the amount of light transmitted.

Hereinafter, a manufacturing process of the above-described liquid crystal display device will be described with reference to the flowchart of FIG. 2.

FIG. 2 is a flow diagram illustrating a manufacturing process of a liquid crystal cell that is generally applied. In the st1 step, a lower substrate is first prepared. A plurality of thin film transistors (TFTs) are arranged on the lower substrate as switching elements, and pixel electrodes are formed in one-to-one correspondence with the TFTs.                         

The st2 step is to form an alignment layer on the lower substrate.

Formation of the alignment layer includes coating and rubbing of the polymer thin film. The polymer thin film is generally referred to as an alignment layer, and should be coated with a uniform thickness over the entire lower substrate, and rubbing should be uniform.

The rubbing is a main process of determining the initial alignment direction of the liquid crystal. The rubbing of the alignment layer enables the normal liquid crystal to be driven and has a uniform display characteristic.

In general, a polyimide series, which is an organic organic alignment layer, is mainly used for the alignment layer.

The rubbing process refers to rubbing the alignment layer in a predetermined direction using a cloth, and the liquid crystal molecules are aligned according to the rubbing direction.

The st3 step represents a process of printing a seal pattern.

The seal pattern in the liquid crystal cell has two functions of forming a gap for liquid crystal injection and preventing leaking of the injected liquid crystal. The seal pattern is a step of uniformly forming a thermosetting resin into a desired pattern, and screen printing has become mainstream.

The st4 step represents a process of dispersing a spacer.

In the manufacturing process of the liquid crystal cell, a spacer having a constant size is used to maintain a precise and uniform gap between the upper substrate and the lower substrate. Therefore, the spacer should be distributed at a uniform density with respect to the lower substrate.

After the spacer spreading process is completed, the process proceeds to the bonding process of the upper substrate as the color filter substrate and the lower substrate as the thin film transistor array substrate (st5).

The joining arrangement of the upper substrate and the lower substrate is determined by the margin given in the design of each substrate, and usually a precision of several μm is required. If the two substrates are out of the bonding error range, light leaks out, so that the desired image quality characteristics cannot be expected when the liquid crystal cell is driven.

The st6 step is a step of cutting the liquid crystal cell prepared in the st1 to st5 step into a unit cell. In general, a liquid crystal cell undergoes a process of forming a plurality of liquid crystal cells on a large area glass substrate and then separating them into a single liquid crystal cell, which is a cell cutting process.

The cell cutting process is a diamond pen having a hardness higher than that of a glass substrate, which is a first cutting process for forming a cutting line on a substrate surface (hereinafter referred to as a “slit formation process”) and a force applied for cutting. It consists of a break process (henceforth a "cutting process") which is a 2nd cutting process.

The st7 step is a step of injecting liquid crystal into the liquid crystal cell cut into each unit cell.

The unit liquid crystal cell has a gap of several μm in an area of several hundred cm ² . Therefore, the vacuum injection method using the pressure difference between the inside and outside of the cell is most widely used as a method of effectively injecting the liquid crystal into the cell of this structure.

A liquid crystal display device can be manufactured by the above-described method, and since the rubbing cloth corresponds to the substrate size in the current step of the rubbing process, it does not matter, but the rubbing size is limited because the larger the substrate size, the rubbing. In the fabrication process, the fabric is cut vertically to fit the size, but there is a problem in that rubbing scratches occur due to the nonuniformity of the aeration generated on the cutting surface.

A description with reference to FIGS. 3 and 4 is as follows.

3 is a view illustrating a rubbing roller wound around a substrate and a rubbing cloth, and FIG. 4 is a view illustrating a rubbing cloth.

As shown in the drawing, the rubbing process is performed while moving the rubbing roller 32 on which the rubbing cloth 30 is wound in one direction 24 on the substrate 22 on which the alignment film 40 is applied. The fine shape (not shown) having a predetermined angle is formed on the surface of the alignment film 40 by the surface shape of the ().

At this time, as shown in Figure 4, the size of the currently used rubbing cloth 30 is short in the transverse direction (I-I cutting direction) to use for a large area substrate as shown. In order to solve this problem, a method of cutting the rubbing cloth 30 in the longitudinal direction (II-II cutting direction) and winding the rubbing roller 32 in the longitudinal direction (II-II cutting direction) can be considered. In this case, since the cutting is vertically cut (horizontal direction), the non-uniformity of the collecting occurs at the time of cutting.

Since the cutting surface (II-II cutting direction) in which the aeration is uneven is wound on the roller, it merely leaves a problem of rubbing scratches on the surface of the substrate.

The rubbing scratches cause a misalignment of the liquid crystals, thereby degrading the image quality of the liquid crystal panel.

In order to solve such a problem, a cotton cloth can be used, and when using the cotton cloth, a size can be corresponded, but since foreign substances are generated by cotton, cotton is not used at present.

The present invention has been made for the purpose of solving the problems as described above, by dividing the rubbing cloth according to the number of panel surface defined in the large-area substrate, winding the divided rubbing cloth parallel to a single rubbing roller rubbing process Suggest how to proceed.

In this manner, the rubbing process can be performed without rubbing defects on the large-area substrate.

Rubbing means according to the present invention for achieving the above object is a rotary roller having the same size as the transverse direction of a large area substrate of 1m × 1m or more; It includes a plurality of rubbing cloth of a predetermined area wound in one direction on the rotary roller.

At this time, the plurality of rubbing cloth is produced by cutting a large area of the rubbing cloth produced with a constant horizontal length and vertical length in the direction of the ablation.
In addition, each of the plurality of rubbing cloths has a spacing interval of a predetermined distance, and the spacing interval corresponds to the dummy area of the substrate.

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

Example

A characteristic of the present invention is to separate the rubbing cloth of a predetermined area which is currently manufactured in the direction of sacking, that is, in the transverse direction of the rubbing cloth, and to wind the rubbing process on a large area substrate by winding them in parallel with each other on a single rubbing roller. It features.

5 and 6 are views showing a rubbing roller and a rubbing roller wound around the rubbing cloth according to the present invention.

As shown in FIG. 5, the large area of the rubbing cloth 100 currently produced is cut along the sacking, ie, in the transverse direction of a rubbing cloth, and several rubbing cloth 102 of the same area is produced.

For example, if 18.1 inches are arranged in 3x3 at the substrate size of 1000x1200, the rubbing cloth may be divided into three.

As shown in FIG. 6, the divided rubbing cloth 102 is wound around the rubbing roller 104 in one direction.

At this time, since the rubbing cloth wound around the rubbing roller 104 and the rubbing cloth D correspond to a dummy area of a large-area glass substrate (not shown), there is no problem in the rubbing process.

A description with reference to FIG. 7 is as follows. 7 is a view illustrating a rubbing roller wound with a rubbing cloth as described above and a substrate in which a rubbing process is performed using the rubbing roller.

The large-area substrate 200 is subjected to a process of cutting to produce a liquid crystal panel of a desired size after a number of processes.                     

At this time, the area where the cutting line 202 is located is a dummy area E not included in the actual size of the liquid crystal panel, and the area D between the rubbing cloth and the rubbing cloth 102 is the dummy. It is located in correspondence with the region E.

As shown in the drawing, a rubbing process is applied to the surface of the substrate 200 to which the alignment layer 206 is applied using the rubbing means (rubbing roller 104 on which the rubbing cloth 102 is wound) 204 according to the present invention. As it proceeds, a region E in which rubbing does not proceed in one direction exists in the substrate 200 as much as the region between the rubbing cloth and the rubbing cloth 102.

As described above, the unrushed region E is a dummy region in the large area substrate 200, and thus is not actually visible in the cut liquid crystal panel.

Therefore, there is no problem in manufacturing the liquid crystal panel.

By using the rubbing means manufactured as described above, it is possible to perform a rubbing process without rubbing defects on a large area substrate of 1m × 1m or more.

The rubbing means according to the present invention as described above can improve the yield of the product because the rubbing defect such as rubbing scratch does not occur on the surface of the substrate during the process of rubbing the large area substrate can reduce the defect of the liquid crystal panel .

Claims (3)

A rotating roller having the same size as the transverse direction of the large-area substrate of 1 m × 1 m or more; A plurality of rubbing cloths of a predetermined area wound in one direction and having a predetermined distance apart from the rotating roller Rubbing means comprising. The method of claim 1, The plurality of rubbing cloth is a rubbing means produced by cutting a large area of the rubbing cloth produced with a constant horizontal length and vertical length in the direction of sacking. The method of claim 1, Rubbing means corresponding to the dummy area of the substrate.

Images