lcd panel rubbing cloth factory

G02F1/13378—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation

G02F1/133784—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation by rubbing

The present invention relates to a rubbing cloth material for manufacturing a liquid crystal panel. In the liquid crystal panel manufacturing process, alignment treatment is performed using a rubbing roller in which a rubbing cloth material having a raised pile is attached to the outer peripheral surface of a metal roller with a double-sided adhesive tape. The alignment treatment is an operation of uniformly rubbing the surface of the alignment film formed on the surfaces of the two substrates constituting the liquid crystal panel with the pile on the surface of the rubbing roller that rotates at a high speed. The object is to impart molecular orientation. Although this process is called an alignment process or a rubbing process, the present invention relates to a rubbing cloth material used in a rubbing process essential for liquid crystal panel production.

The rubbing process will be briefly described with reference to FIG. 5. In rubbing, a cloth material 2 having a pile standing on its surface is attached to the outer peripheral surface of a metal roller 1 with a double-sided adhesive tape and rotated at high speed. The surface of the alignment film formed on the surface of the substrate 5 constituting the liquid crystal panel is rubbed at high speed with the pile of the cloth material, and unidirectional molecular alignment is imparted to the surface of the alignment film. It is the purpose.

In addition, the code | symbol d in FIG. 5 is commonly called the amount of cutting, and has shown the length which the pile of a cloth material touches an alignment film (board | substrate), and influences alignment performance.

A liquid crystal display element used for a transmissive liquid crystal display panel is opposed to a TFT substrate on which a driving element (TFT) made of a thin film transistor is formed and a CF substrate on which a color filter (CF) is formed with a small gap therebetween. The liquid crystal is sealed in the gap. An ITO electrode patterned as a pixel electrode is disposed on the surface of the TFT substrate, and an alignment film is formed so as to cover the surface of the ITO electrode.

The TFT substrate and the CF substrate are arranged so that the alignment films face each other, and the alignment films on both substrates are in contact with the sealed liquid crystal. The alignment film on the TFT substrate surface and the CF substrate surface is subjected to an alignment process using a rubbing cloth material to align liquid crystal molecules. The rubbing cloth material is usually attached to the outer peripheral surface of a roller such as aluminum or stainless steel. The surface of the alignment film is rubbed with the rubbing cloth material by bringing the rubbing cloth material on the outer peripheral surface into contact with the alignment film surface while rotating the roller. As described above, when the alignment film is subjected to a rubbing treatment, ultrafine grooves are formed on the surface of the alignment film itself, or uniaxial alignment is imparted to polyimide molecules that are polymers forming the alignment film. When the liquid crystal comes into contact with the alignment film subjected to the rubbing treatment in this way, liquid crystal molecules are arranged in the direction rubbed with the rubbing cloth material, thereby realizing uniform switching characteristics of the liquid crystal by the electric field. The performance of liquid crystal alignment by rubbing affects the uniformity of display characteristics, which is the most important for a liquid crystal panel.

As the rubbing cloth material, a velvet fabric composed of a ground cloth and a pile woven in a raised state on the ground cloth is generally used. As materials for piles, those using long fibers (filaments) such as rayon and nylon and those using short fibers such as cotton are known. As the velvet fabric structure used for the rubbing cloth material, a known first pile velvet fabric as shown in FIG. 7 using cupra rayon for warp and weft of the fabric structure and viscose rayon for the pile (Patent Document) 1) is common, and a velvet structure of a V-shaped pile as shown in FIG. 8 using cotton as a pile (see Patent Document 2) is also used. These combinations are not fixed, and even if cotton is used for the pile, it is possible to weave with the first pile structure, and any structure is velvet fabric of thermoplastic synthetic fibers such as acetate fiber and polyester fiber. It can also be applied to.

In the rubbing cloth material using this type of velvet fabric, the pile is not erected vertically with respect to the ground cloth, but the direction in which the tip of the pile follows the root of the pile with respect to the rotation direction of the rubbing roller. It is known that inclining to an effective angle is an effective means for avoiding uneven alignment due to non-uniform rubbing (see Patent Document 3).

However, in the velvet structure according to the prior art, the pile cannot be inclined at an arbitrary angle with respect to the normal direction of the surface of the cloth material only by the action of the fiber weaving structure.

As a conventional method of inclining a pile of a rubbing cloth material, a velvet using rayon for a pile portion is described in detail in Patent Document 3. Specifically, a velvet cloth woven by a general manufacturing method is immersed in a glyoxal-based cellulose-reactive resin, combed with a brush in a curing machine, and then the resin is heated and cured to maintain the inclination. . This method is called resin impregnation and uses a cellulose-reactive resin, so that it is used for fibers composed of regenerated cellulose fibers other than rayon, polynosic fibers, lyocells and the like and cellulose derivatives (hereinafter referred to as cellulosic fibers). It is valid. There are some problems in providing the slope to the pile by such resin processing, and there is an urgent need to solve it in the future for higher definition and higher yield of liquid crystal panels.

Moreover, in the rubbing cloth which consists of a cotton pile, there is no effective means to incline a pile uniformly irrespective of resin impregnation.

In the above conventional resin processing method, there is a high possibility that the processing shape and the cloth characteristics will vary for each processing lot. For this reason, in the manufacturing process of the liquid crystal display panel, it was confirmed whether or not the velvet fabric of the lot can withstand use by carrying out trial rubbing in advance using the received velvet fabric and checking the orientation quality. Above, used in the manufacturing process. Even if such an arrival check is executed, the variation itself in the cloth quality itself is not improved, and it is said that unexpected rubbing failure does not end.

In addition, the conventional rayon velvet also has a problem related to the resin itself used for processing. That is, since the rubbing cloth material (velvet) is immersed in the cellulose reaction type resin, the resin adheres to the surface of each single fiber constituting the pile of the velvet. This resin tends to be relatively hard and brittle, and during rubbing, it becomes a foreign substance due to wear and drop off, and may adhere to the alignment film surface and cause defects such as display unevenness (see Non-Patent Document 1). ). Moreover, the foreign material wound in the pile may cause a damage | wound on the surface of an alignment film.

Further, the cellulose-reactive resin is an aqueous emulsion, and a rubbing cloth material using cupra as a ground yarn is very easily deformed in a state containing moisture. For this reason, the weft of the rubbing cloth material is deformed into a bow shape (commonly referred to as “boeing”), so that the so-called bend in which the weft does not intersect the warp at a right angle easily occurs.

Therefore, the present invention (1) provides a stable inclination to the pile of the rubbing cloth material of the velvet fabric, (2) reduces the elongation of the fabric, ensures the shape accuracy and the shape stability, and (3) the rubbing. The primary purpose is to suppress the generation of static electricity that naturally occurs.

In this case, without expecting the above-mentioned deviation, when the rubbing cloth is attached in parallel with the direction of the rubbing roller"s warp (weaving direction), the pile touches the minute unevenness of the object to be rubbed and vibrates. It is known that horizontal alignment spots are generated in the alignment film.

For this reason, conventionally, when cutting the rubbing cloth material from the original fabric after weaving, it has been necessary to cut it slightly obliquely from the warp direction (weaving direction) in anticipation of the above-mentioned deviation, and there is a problem that a large loss occurs in the fabric It was.

As a means for giving a stable inclination to the pile of the rubbed cloth of the velvet structure, it is desirable to devise the cloth structure itself without relying on resin processing, heat brushing, or the like. The pile of the rubbing cloth material is inclined in a certain direction with respect to the normal of the surface of the cloth material, and the inclination angle is stable in the range of 5 to 60 degrees, preferably 10 to 45 degrees. A velvet fabric that can be controlled is desired.

Further, the weaving method and processing method of the cloth is that there is no generation of foreign matter that causes scratches and contamination on the alignment film surface in the rubbing step of the liquid crystal panel manufacturing process.

In the present invention, in order to obtain a rubbing cloth material in which a pile is erected while maintaining a stable inclination, the present inventors have focused on a method for controlling the tension balance of warp in a velvet fabric.

As a means for alternately increasing or decreasing the warp tension, there is, for example, a method of supplying warp with a double beam and weaving under a condition in which the warp tension of one beam is stronger than the warp tension of the other beam. Actually, when a velvet cloth is woven by this method, the pile can be erected while being inclined in the warp direction. As another means for alternately increasing or decreasing the tension of the warp, there is a method in which highly shrinkable synthetic fibers and ordinary synthetic fibers are alternately arranged and used for the warp. In this case, an appropriate heat treatment is performed after weaving to increase the tension by shrinking the highly shrinkable synthetic fiber. Even in this method, as a result, the tension of the warp can be alternately increased and decreased, and the same effect as that of the double beam method can be obtained.

Next, as a problem to be improved for the rubbing cloth, there is a problem of dimensional stability. This is a problem of fabric stretch during rubbing. A typical velvet rubbing cloth material currently in use uses cupra rayon as a fiber material of the ground cloth. In the liquid crystal panel manufacturing process, in order to prevent electrostatic breakdown of TFT elements (thin film transistor elements), the relative humidity of the atmosphere is set high (about 60%) in order to reduce the generation of static electricity. . It is well known that in a high humidity state, the cellulosic fiber is a fiber that is easily stretched compared to a polyester fiber that is a hydrophobic synthetic fiber. In a liquid crystal display device manufactured using a substrate in which an alignment film is rubbed with a velvet fabric, linear unevenness may occur in a direction parallel to the rubbing roller. As one cause of the occurrence of this unevenness, the ease of elongation of the rubbing cloth material has been reported (see Patent Document 1).

By using a hydrophobic synthetic fiber that is difficult to stretch in a high humidity state, the elongation of the rubbing fabric material can be reduced. In addition, the occurrence of fabric bending can be reduced.

Patent Document 4 states that the rubbing cloth material easily expands and contracts due to environmental temperature and humidity and is difficult to cut with dimensional accuracy. The use of hydrophobic synthetic fibers such as polyester fibers and highly shrinkable synthetic fibers is also effective in dealing with this problem.

Static electricity generated in the rubbing process of the alignment film may destroy the TFT element of the liquid crystal panel. For this reason, it is necessary to leak the generated static electricity to the outside and prevent the accumulation of static electricity. 10 or more for one or both of the warp and weft of the woven fabric of the velvet fabric that is a rubbing fabric -2 Ωcm or more 10 0 Copper sulfide fiber sanderlon having a specific resistance value of Ωcm or less (registered trademark of Nippon Kashiwa Dyeing Co., Ltd.), 10 -2 Ωcm or more 10 6 Conductive fiber kneaded with Ωcm carbon powder, 10 0 Ωcm or more 10 6 If Beltron (registered trademark of Kanebo Co., Ltd.) having a specific resistance value of Ωcm or less is used in the ground yarn, the generated static electricity is leaked by corona discharge, and the accumulation of static electricity is reduced. In addition, coating the conductive resin mixed with carbon powder on the back side of the velvet is also effective in reducing static electricity. Furthermore, if a conductive fiber and a conductive resin are used in combination, a higher effect can be obtained.

In cutting the rubbing cloth material, it is extremely important to accurately cut the warp yarn at a desired angle (see, for example, Patent Document 5). If the base fabric structure of the rubbing cloth material is a single color, it is not easy to accurately set the cutting angle with respect to the warp. At present, the fabric is cut on the premise that the weft intersects with the warp at a right angle, but the current rubbing cloth has a lot of fabric bends. This is estimated to be one of the factors that cause the orientation characteristics to fluctuate.

Therefore, it is important that the rubbing cloth is made of a material that is not easily deformed by temperature and humidity. In order to make it easy to cut at an accurately significant angle, weaving yarns of different colors from the whole ground yarn at regular intervals to the warp, weft or both of the ground yarn of the rubbing cloth material Is effective.

As shown in FIG. 1 (a), the velvet structure is formed of a fabric structure 11 and a pile 12 woven in a standing state on the fabric structure 11. The base fabric braid 11 is woven with the wefts 13 by the warp yarns 14a, 14b, 14b ′ supplied from the double beam. In the rubbing fabric, it is important that one or both of the warp and the weft is made into a hydrophobic ligament fiber such as a polyester fiber.

The velvet structure according to the present invention is not limited to the velvet structure shown in FIG. 1, and for example, a structure such as that shown in FIGS. In the structure shown in FIGS. 2A and 2B, every two piles are inserted into the weft. In FIGS. 2 (a) and 2 (b), warps are abbreviated, but finally, as in FIG. 1, every other piece is woven with a strong and weak tension. That is, weaving is performed by supplying the warp 24a with a strong tension and the warps 24b and 24b "with a weak tension. In this structure, as shown in FIG. 11, the weft yarns C and D are crushed above the weft yarns B to form dumplings. In such a state, the pile 12 is pressed by the weft yarns A to D and given a predetermined angle of inclination in the direction along the warp direction as shown in the figure. Further, even in other velvet structures, it is possible to incline the pile by arranging the ground warp yarn of the velvet cloth material alternately with two kinds of strength and weakness.

In the structure shown in FIG. 1, as another means for alternately increasing or decreasing the warp tension, there is a method in which one warp is a heat-shrinkable fiber. That is, one warp 14a is made of heat-shrinkable fibers, and the warps 14b and 14b "are woven with a normal one beam with almost the same tension, and then heat treatment is applied to the velvet to shrink the warp 14a of heat-shrinkable fibers. Thus, the tension is higher than that of the other warps 14b and 14b ′. In this method, the fiber that thermally shrinks in the machine direction plays the role of a warp with high tension. Accordingly, the pile can be inclined by the same action as the method using the double beam. The ground yarn used in the present invention is preferably a highly shrinkable synthetic fiber, more preferably a polyester fiber having a shrinkage rate of 10% or more (130-150 ° C. dry ripening) or a boiling water shrinkage rate (BWS) of 8% or more. It is preferable that The advantage of using a highly shrinkable synthetic fiber (polyester fiber) for the ground yarn is that the ground yarn shrinks by heat treatment after weaving so that the structure can be made denser. It is known that when a gap is formed between piles in a rubbing cloth for producing a liquid crystal panel, it is known that the rubbing unevenness is generated. A major feature of this method is that a dense structure can be formed beyond the limit of weaving of the loom.

The velvet cloth material was cut into a width of 5 cm and a length of 30 cm so that the angles with respect to the warp were 0.5 degrees, 10 degrees, 15 degrees, 30 degrees, and 45 degrees, thereby preparing test pieces. The elongation in the standard state and the moisture absorption state for each angle from the warp of each sample when 5 kg tensile stress is applied to each test piece is shown. By this measurement, it is possible to know the elongation (particularly humidity dependency, anisotropy) of the fabric structure.

The sample for the comparative example is a rayon velvet using as a base yarn a cupra manufactured by Asahi Kasei Kogyo Co., Ltd., currently marketed for liquid crystal rubbing.

As a result, in the standard state, the elongation with respect to the stress of 5 kg / 5 cm does not show a large difference between the samples 1 and 2 and the comparative product until the angle from the warp is 10%. A clear difference was clearly observed between Samples 1 and 2 and the comparative control product. The elongation in the hygroscopic state was that of the samples 1 and 2 in which polyester fibers were used for the ground yarn. It is clearly less than the comparative control product, and in any case, it is shown that the sample 2 using the high shrinkage yarn for the weft is less likely to elongate than the sample 1. Therefore, it can be said that the dimensional stability as the rubbing cloth material is superior in the order of sample 2> sample 1> comparison target product in the sample 1, the sample 2, and the comparison target product.

Table 2 shows the velvet weaving conditions in which the pile of the rubbing cloth material is inclined by the velvet weave structure according to the present invention, and the pile inclination angle observed in the length direction of the fabric (angle with respect to the vertical direction of the fabric structure). It is.

The generation level of static electricity of the rubbing cloth material according to the present invention was comparatively evaluated. First, the liquid crystal alignment film was rubbed with each rubbing cloth in a state of 60% humidity. At this time, the depth of cut (d in FIG. 5) was 0.5 mm, and the amount of static electricity generated on the roller during rubbing was evaluated by measuring the charged voltage.

Sample 9 is obtained by backing a conductive resin in which carbon particles (powder) are mixed into a resin on the back surface of sample 7 in the same manner as sample 8. In Sample 9, the most remarkable effect of decreasing the charged voltage was recognized. This is because static electricity is released to the conductive resin more quickly and discharged from the entire back of the rubbing cloth material.

According to the present invention, a stable slope is imparted to the pile of the rubbed cloth material of the velvet fabric, the elongation of the fabric is reduced, the shape accuracy and the shape stability are ensured, and the generation of static electricity that is inevitably associated with the rubbing is generated. Is suppressed. Further, the present invention can form a structure that reduces the inclination of the pile in the direction parallel to the weft.

前記経糸として、張力の異なる合成繊維を組み合わせて製織したことにより構成されることを特徴とする液晶パネル製造用ラビング布材。A rubbing cloth material for producing a liquid crystal panel of a velvet woven fabric having a ground fabric composed of warps and wefts, and a pile yarn woven in the warp direction of the fabric structure,

A rubbing cloth material for producing a liquid crystal panel, characterized in that the warp yarn is formed by weaving synthetic fibers having different tensions.

前記地布組織の経糸の、地布面内の張力分布を変えることによって、地布材の表面の法線に対して経糸の方向の傾斜を前記パイルに与えたことを特徴とする液晶パネル製造用ラビング布材。A rubbing cloth material for manufacturing a liquid crystal panel according to claim 1,

Manufacturing the liquid crystal panel, wherein the pile is inclined in the direction of the warp with respect to the normal of the surface of the fabric by changing the tension distribution in the fabric surface of the warp of the fabric structure Rubbing cloth material.

前記パイル糸が、地布材の表面の法線に対して経糸の方向に傾斜し、前記パイル糸の、前記法線に対する傾斜角度が１０度以上４５度以下であることを特徴とする液晶パネル製造用ラビング布材。A rubbing cloth material for manufacturing a liquid crystal panel according to claim 1 or 2,

The pile yarn is inclined in the warp direction with respect to the normal line of the surface of the fabric material, and the inclination angle of the pile yarn with respect to the normal line is not less than 10 degrees and not more than 45 degrees. Rubbing cloth material for manufacturing.

前記地布組織を構成する複数の経糸のうち、所定の本数おきの経糸に、他の経糸よりも弱い張力をかけながら製織されたことを特徴とする液晶パネル製造用ラビング布材。A rubbing cloth material for manufacturing a liquid crystal panel according to claim 1 or 2,

A rubbing cloth material for manufacturing a liquid crystal panel, wherein a predetermined number of warp yarns are woven while applying a weaker tension than other warp yarns among a plurality of warp yarns constituting the base fabric structure.

前記二重ビームの一方の経糸が他方の経糸より強い張力で製織され、強い張力の経糸と弱い張力の経糸が交互に配置されることにより構成されることを特徴とする液晶パネル製造用ラビング布材。A rubbing cloth material for manufacturing a liquid crystal panel according to claim 4,

A rubbing cloth for manufacturing a liquid crystal panel, wherein one warp of the double beam is woven with a stronger tension than the other warp, and a high tension warp and a weak tension warp are alternately arranged. Wood.

前記地布組織を構成する地糸の一部に高収縮性の合成繊維を用いて製織され、当該高収縮性の合成繊維を収縮させたことを特徴とする液晶パネル製造用ラビング布材。A rubbing cloth material for manufacturing a liquid crystal panel according to claim 1 or 2,

A rubbing cloth material for manufacturing a liquid crystal panel, characterized in that a part of the ground yarn constituting the base fabric structure is woven using a high-shrinkage synthetic fiber and the high-shrinkage synthetic fiber is shrunk.

The rubbing cloth material for producing a liquid crystal panel, wherein the highly shrinkable synthetic fiber is a polyester fiber having a boiling water shrinkage of 8% or more.

前記パイル糸は、電気比抵抗値が１０8Ωｃｍ以上１０10Ωｃｍ以下の合成繊維よりなる液晶パネル製造用ラビング布材。It is a rubbing cloth material for liquid crystal panel manufacture according to any one of claims 1 to 4,

The pile yarn is a rubbing cloth material for manufacturing a liquid crystal panel comprising a synthetic fiber having an electrical specific resistance value of 10 8 Ωcm or more and 10 10 Ωcm or less.

前記ラビング布材の地布組織の経糸及び緯糸のうちの少なくとも一方は、電気比抵抗値が１０-2Ωｃｍ以上１０6Ωｃｍ以下の導電性合成繊維を含むことを特徴とする液晶パネル製造用ラビング布材。It is a rubbing cloth material for liquid crystal panel manufacture according to any one of claims 1 to 7,

A rubbing for manufacturing a liquid crystal panel, wherein at least one of the warp and the weft of the base fabric structure of the rubbing cloth material includes a conductive synthetic fiber having an electric specific resistance value of 10 −2 Ωcm or more and 10 6 Ωcm or less. Cloth material.

A rubbing cloth material for manufacturing a liquid crystal panel, wherein a resin containing a conductive material is applied and cured on the back side of the ground cloth structure of the rubbing cloth material.

Rubbing cloth for aligning liquid crystal and method for fabricating thereof and apparatus for fabricating thereof and method for fabricating liquid crystal display device using the same

Rubbing cloth for aligning a liquid crystal, method of manufacturing the same, apparatus for manufacturing the same and method of manufacturing a liquid crystal display using the same

First, a rubbing cloth material 1 made of the woven fabric structure of FIG. 1 was produced. A velvet with a pile height of 2.5mm is used as the ground warp yarn, using twisted double yarns of polyester fiber 56 dtex, as the weft yarn using polyester fiber 84 dtex double yarn, as the pile yarn using cotton No. 60 twin yarn. Woven fabric. The density of ground warp was 35 per cm, and the density of ground weft was 75 per cm. A rubbing cloth material 1 was obtained by coating an acrylic resin on the pile-free side of the fabric. Next, S50C steel manufactured by Nakayama Co., Ltd. is used to prepare a cutting blade with a thickness of 1 mm and a cutting edge taper of 35 ° to 40 °. The heater is energized with heat to melt the rubbing cloth material 1 almost parallel to the ground warp. Cut. The temperature of the blade edge at this time was 265 ± 5 ° C.

First, a rubbing cloth material 2 having a woven fabric structure as shown in FIG. 5 was produced. A velvet fabric was woven using double twisted yarns of polyester fiber 56 dtex as the ground warp, using polyester 56 dtex as the weft and using triacetate 84 dtex double as the pile yarn. The density of the ground warp was 23 per cm, and the density of the ground weft was 45 per cm. A rubbing cloth material 2 was obtained by coating an acrylic resin on the pile-free side of the fabric. Next, the same cutting blade as in Example 1 was prepared, the heater was energized and heat was applied, and the rubbing cloth material 2 was melt cut in a direction substantially parallel to the ground warp and 15 degrees apart from the ground warp. The temperature of the blade edge at this time was 245 ± 5 ° C.

First, a rubbing cloth material 3 made of the woven fabric structure of FIG. 5 was produced. Nylon fiber (nylon 6) 56 dtex (17 filaments) is used as the ground warp and ground weft. The ground warp yarn is used as various twisted yarns having a lower twist of 900 times / m and an upper twist of 600 times / m. The ground warp density is 23. The yarn / cm, the weft yarn density was 47.5 yarns / cm, and the pile yarn was triacetate 84 dtex double yarn. A velvet fabric was woven and finished by a normal processing method to obtain a rubbing cloth 3. Next, the same cutting blade as in Example 1 was prepared, the heater was energized by applying heat, and the rubbing cloth material 3 was melt cut in a direction substantially parallel to the ground warp and 15 degrees away from the ground warp. The temperature of the blade edge at this time was 210 ± 5 ° C.

First, a rubbing cloth material 4 made of the woven fabric structure of FIG. 5 was produced. Polypropylene fiber 56 dtex (24 filaments) is used as the ground warp and ground weft, the ground warp is used as plied yarns of 750 times / m for the lower twist and 450 times / m for the upper twist, and the density of the ground warp is 23 / cm, The weft yarn density was 42 yarns / cm, and the pile yarn was triacetate 84 dtex double yarn. A velvet fabric was woven and finished by a normal processing method to obtain a rubbing cloth 4. Next, the same cutting blade as in Example 1 was prepared, and the heater was energized with heat, and the rubbing cloth material 4 was melt cut in a direction substantially parallel to the ground warp and 15 degrees apart from the ground warp. The temperature of the blade edge at this time was 160 ± 5 ° C.

First, a commercially available cotton rubbing cloth material 5 having the woven fabric structure of FIG. 6 was prepared. The commercially available ground warp, ground weft and pile yarn are all made of cotton No. 40 twin yarn. The pile length is 2.5 mm. The back of this fabric is said to be coated with vinyl acetate resin. Next, a Thomson blade made of steel made by Nakayama Co., Ltd. was prepared, and the rubbing cloth material 5 was press-cut in a direction substantially parallel to the ground warp and 15 degrees away from the ground warp. The temperature of the blade edge at this time was normal temperature.

The end face of the rubbing cloth material cut in Examples 1 to 4 and Comparative Example 1 was rubbed with a velvet cloth, and the falling state of the pile was visually observed.

As for the rubbing cloth materials of Examples 1 to 4 which were melt-cut, both the melt-cut material almost parallel to the ground warp yarn and the melt-cut material in the direction deviated by 15 degrees are melted and deformed. There was little loss of pile.

On the other hand, for the rubbing cloth material of Comparative Example 1 which was subjected to press cutting at room temperature, the warp and weft of the ground cloth were not melted at all, so the base of the pile was coated on the woven structure and the back of the fabric In the part where the fabric structure collapsed by press cutting, the root of the pile was insufficiently fixed, and the material cut almost parallel to the ground warp was also separated by 15 degrees from the ground warp. There were many piles that were cut off in the direction. Therefore, in the rubbing cloth material of Comparative Example 1, there is a possibility that the pile falls off during the alignment film rubbing of the liquid crystal display.

As we view the television today, the warbled picture on a 1950s TV set seems almost a distant dream. The impressive Liquid Crystal displays (LCD) technology has been a ubiquitous part of our everyday lives for decades. Liquid Crystal Displays (LCDs) are used in all electronic devices such as in televisions, laptops, computers, cell phones and so on.

Rubbing is one of the most crucial processes required for LCD fabrication. The proper anchoring of liquid crystal, a component required for visual image production, is achieved via rubbing. Internationally, the display manufacturing industries have large rubbing machines for in-house consumption and R&D purposes. But even in the present day of globalization, researchers in India rely on manual rubbing process with not-so-well-reproducible results.

In view of its importance, a group of researchers from the University of Hyderabad have developed and designed a low-cost, indigenous rubbing machine—employed for the manufacturing of LCDs. Having the potential of creating new market forces across the globe, the machine is first of its kind in India and the cheapest in the world.

Liquid crystal display (LCD) screens are manufactured by assembling two transparent electrically conducting glass substrates in which the liquid crystal is confined. Aligning the sandwiched liquid crystal in a twisted fashion is very crucial for LCDs fabrication. The steps involved in creating the alignment layer include deposition of a thin layer of polymer, thermal treatment and a controlled uni-directional mechanical rubbing using soft velvet. Rubbing process creates microgrooves, where the liquid crystals get in, and so, a required alignment of liquid crystals is achieved over the entire LCD. Thus a uniform rubbing of substrate is very crucial for LCDs.

Dr Surajit Dhara, Professor, University of Hyderabad has been working actively in the field of liquid crystals for several years. The rubbing machine designed by Dr Dhara is simple to operate, portable, and inexpensive. A rotating spindle, stringed by a special velvet rubbing cloth is positioned above a vertically movable stage. The stage is put on a track so that it can move forward and backwards in the horizontal direction with specified speed. The glass plate is held by a vacuum chuck for which a vacuum pump has been included and integrated with the system. The glass plate along with vacuum chuck is held on a rotation stage so that it can be rotated and positioned at any required angle. Well defined microgrooves are created on the polymer coated glass plate as it moves along the stage on the track. The rubbing pressure is adjusted by changing the gap between the spindle and the glass plates at different vertical planes.

For various rubbing orientations, the entire process is repeated two or three times under similar conditions. While assembling the LCD panel, two plates are arranged in such a way that the microgrooves are orientated perpendicular to each other giving a twisted structure to the inserted liquid crystal.

Though LCDs are not manufactured in India yet the advent of this technology in advance is a step ahead in future. Transferred to Holmarc Opto-Mechatronics Pvt. Ltd. India, the machine is commercially sold in India and abroad. Currently, the technology is being used for R&D purposes—for making prototypes and in studying fundamental aspects of liquid crystals & LC based vehicles. It is expected that the machine will not only encourage LCDs fabrication in India but will also significantly lower the production cost.

The present invention relates to a rubbing cloth and an LCD (Liquid Crystal Display), and more particularly to a rubbing cloth for aligning a liquid crystal, method of manufacturing the same, apparatus for manufacturing the same and method of manufacturing an LCD using the same.

In general, an LCD apparatus displays image information using electro-optics properties of a liquid crystal. Some LCD apparatus transmits a light when an electric field is not applied to the liquid crystal. But some LCD apparatus intercepts a light when an electric field is not applied to the liquid crystal, and transmits the light when the electric field is applied to the liquid crystal.

Some LCD apparatus intercepts a light when an electric field is not applied to the liquid crystal, and the LCD apparatus transmits the light when the electric field is applied to the liquid crystal.

The alignment film is as a polyimide thin film layer. When rubbing the alignment film against a rubbing cloth toward the uniform direction, an alignment groove is formed on the alignment film. The alignment of the liquid crystal is performed by means of the alignment groove. The rubbing cloth wind around an outer circumference of a rubbing roller, and the alignment groove is formed on the alignment film by rubbing the rubbing roller having the rubbing cloth against the alignment film.

Hereinafter, manufacturing processes of the rubbing cloth will be described with reference to FIGS. 1A to 1F. Here, a term referred to as a “rubbing cloth fabric” indicates a cloth having a length and a width shorter than the length.

Referring to FIG. 1A, the rubbing cloth fabric 100 is manufactured by interweaving a weft 1 with a warp 2, the warp 2 intersecting the weft 1 and having a length longer than that of the weft 1. The rubbing cloth fabric 100 includes a rubbing pile 110 irregularly formed on the rubbing cloth fabric 100 as shown in FIGS. 1B and 1C.

Referring to FIG. 1D, a roller brush 200 for rearranging the rubbing pile 110 is disposed in a direction parallel to a width direction of the rubbing cloth fabric 100. The width direction is the same direction in which the weft 1 is formed on the rubbing cloth fabric 100. When the roller brush 200, which is in contact with the rubbing cloth fabric 100, is transferred, the rubbing pile 110 is realigned in a direction parallel to the warp 2. The realigned rubbing pile has been allowed to have a reference numeral “115”.

As shown in FIG. 1E, the rubbing cloth fabric 100 having the realigned rubbing pile 115 is cut into pieces. A piece of rubbing cloth fabric which is cut from the rubbing cloth fabric 100 is defined as a rubbing cloth 150.

The rubbing cloth 150 is attached onto a rubbing roller 300 which has a length longer than a width of the alignment film. In order to attach the rubbing cloth 150 onto the rubbing roller 300, the rubbing cloth 150 has a length similar to a length of the rubbing roller 300, and has a width similar to a length of the circumference surface of the rubbing roller 300. That is, the warp 2 of the rubbing cloth 150 is aligned along the circumference surface of the rubbing roller 300, the weft 1 is aligned in the length direction of the rubbing roller 300, and the rubbing pile 110 is aligned parallel to the weft 1.

As shown in FIG. 1F, when the rubbing roller 300, on which the rubbing cloth 150 is wound, rotates and simultaneously applies pressure to the alignment film 400, the alignment groove is formed on the alignment film 400.

However, when the alignment groove is formed by means of the conventional rubbing roller 300 to which the rubbing cloth 150 is attached, the liquid crystal cannot be precisely aligned with the alignment groove due to a scratch formed on the alignment film 400. It is difficult to totally control a tension of the rubbing cloth fabric 100 when the rubbing roller 300 is rubbed against the alignment film 400 along the warp 2. When the tension of the rubbing cloth fabric 100 is not precisely controlled, the rubbing pile 110 is irregularly distributed on the rubbing cloth fabric 100. Therefore, the liquid crystal cannot be precisely aligned with the alignment groove.

Also, when the alignment film 500 has a larger size than that of the rubbing cloth 150, as shown as reference numeral 500 in FIG. 1E, it is not possible to form the alignment groove by means of the rubbing cloth fabric 100 having a width shorter than that of the alignment film 500.

In one aspect of the invention, there is provided a rubbing cloth for aligning a liquid crystal, the rubbing cloth being formed by cutting a portion of a rubbing cloth fabric in a length direction of a warp on the rubbing cloth fabric, wherein the rubbing cloth fabric comprising: a warp having a first length; a weft having a second length shorter than the first length and being interweaved with the warp; and a rubbing pile aligned along the length direction of the weft.

In another aspect, there is provided a method for manufacturing a rubbing cloth for aligning liquid crystal, comprising: making a rubbing cloth fabric including a warp having a first length, a weft having a second length shorter than the first length and being interweaved with the warp, and a rubbing pile irregularly formed on the rubbing cloth fabric; aligning the rubbing pile in a length direction of the weft; and cutting the rubbing cloth fabric in a length direction of the warp.

In further aspect, there is provided an apparatus for manufacturing a rubbing cloth, comprising: a rubbing belt installed in a width direction of a rubbing cloth fabric, wherein the rubbing cloth fabric includes a warp having a first length, a weft having a second length shorter than the first length and being interweaved with the warp, and a rubbing pile formed on a surface of the rubbing cloth fabric; a pulley for receiving a rotating force and rotating the rubbing belt in response to the rotating force; and means for supplying the rotating force to the pulley.

In still another aspect, there is provided a method for manufacturing an LCD, comprising: fabricating a TFT substrate having a TFT, a power supply line for supplying a power to the TFT, and a pixel electrode for receiving the power outputted from the TFT; fabricating a color filter substrate having RGB pixels and a common electrode, and being coupled to the TFT substrate; forming a rubbing groove by rubbing a rubbing roller against an alignment film formed on the TFT substrate and the color filter substrate, wherein the rubbing roller is wound with a rubbing cloth formed by cutting a rubbing cloth fabric, and wherein the rubbing cloth fabric has a warp having a first length, a weft having a second length shorter than the first length and being interweaved with the warp, and a rubbing pile aligned along the length direction of the weft; assembling the TFT substrate with the color filter substrate; and interposing a liquid crystal between the TFT substrate and the color filter substrate.

According to the present invention, the rubbing cloth is formed by interweaving the warp with the weft having a length shorter than that of the warp and the rubbing pile is aligned parallel to the warp. Accordingly, it is able to manufacture the rubbing cloth having a various size without a length of the alignment film and increase yield of the rubbing cloth.

The rubbing cloth fabric 600 is fabricated by interweaving a weft 1 with a warp 2 having a length longer than that of the weft 1. The rubbing pile 118 having a length shorter than that of the weft 1 is disposed on the rubbing cloth fabric 600. The rubbing pile 118 is aligned at an angle about ±30 degrees with respect to the weft 1. Preferably, the rubbing pile 118 is aligned parallel to the weft 1 of the rubbing pile 118.

Disposing the rubbing pile 118 to have the direction parallel to the weft 1 is for precisely controlling a tension of the rubbing cloth fabric 600. When the rubbing pile 118 is aligned to have a direction parallel to the warp 2 having the length longer than that of the weft 1, the tension of the rubbing cloth fabric 600 cannot be precisely controlled, and the rubbing pile 118 is irregularly aligned, so that rubbing processes are not precisely performed. When the rubbing pile 118 is aligned to have a direction parallel to the weft 1 having the length shorter than that of the warp 2, the tension of the rubbing cloth fabric 600 can be precisely controlled, thereby preventing the rubbing pile 118 from being irregularly aligned.

Hereinafter, a method for manufacturing the rubbing cloth will be described with reference to FIGS. 2A to 2C and rubbing processes performed by the rubbing cloth will be described with reference to FIG. 2D.

Referring to FIG. 2A, the rubbing cloth fabric 600 includes the weft 1 and the warp 2 having the length longer than that of the weft 1. The weft 1 is interweaved with the warp 2 in order to fabricate the rubbing cloth fabric 600. The rubbing pile 110 is irregularly disposed on the rubbing cloth fabric 600.

The direction that the warp 2 is formed on the rubbing cloth fabric 600 is defined as a length direction of the rubbing cloth fabric 600, and a direction that the weft 1 is formed on the rubbing cloth fabric 600 is defined as a width direction of the rubbing cloth fabric 600.

As shown in FIG. 2B, the rubbing pile 110 disposed on the rubbing cloth fabric 600 is realigned by means of a belt shape rubbing apparatus 700. The realigned rubbing pile has been allowed to have a reference numeral “118”.

The rubbing apparatus 700 includes a rubbing belt 710 for realigning the rubbing pile 110, first and second pulleys 720 and 730 for receiving a rotating force and driving the rubbing belt 710, and a motor 740 for supplying the rotating force to the first or second pulley 720 and 730 to rotate the first and the second pulleys 720 and 730. The rubbing pile 118 is aligned at an angle about ±30 degrees with respect to the weft 1 by means of the rubbing belt 710. FIG. 2B shows exemplary rubbing piles aligned at an angle of ±30 degrees with respect to the dotted lines that are parallel to the weft.

As shown in FIG. 2C, the rubbing cloth fabric 600 is cut to fabricate the rubbing cloth 800. Particularly, the rubbing cloth 800 is cut to have a width similar to the length of the circumference of the rubbing roller 300, and to have a length similar to the length of the rubbing roller 300.

Accordingly, it possible to prevent a scratch from being formed on the alignment film 400 due to the rubbing pile 115 irregularly disposed on the rubbing cloth 800 during rubbing process of the alignment film 400.

Also, even though the alignment film 400 has a size larger than the width of the rubbing cloth fabric 600, it is able to obtain the rubbing cloth 800 having a size appropriate to the size of the alignment film 400 by controlling a cutting length in the length direction of the rubbing cloth fabric 600.

The LCD includes a TFT substrate and a color filter substrate. A polyimide thin film layer is formed on the TFT substrate having a TFT, a gate line, a data line and a pixel electrode. A rubbing process is performed on the polyimide thin film layer so as to align the liquid crystal.

The rubbing cloth 800 wound around the rubbing roller 300 is fabricated by interweaving the weft 1 and the warp 2 having the length longer than that of the weft 1, and the rubbing pile 118 parallel to the weft 1 thereon is disposed on the rubbing cloth 800.

The alignment groove is formed on the polyimide thin film layer by rubbing the rubbing pile 118 of the rubbing cloth 800 against the polyimide thin film layer. The alignment groove is formed to have a direction parallel to the aligning direction of the rubbing pile 118, so that the liquid crystal is aligned parallel to the aligning direction of the rubbing pile 118.

The alignment groove is formed on the color filter substrate by the process similar to above process. The alignment groove is tilted by a predetermined angle with respect to the alignment groove formed on the TFT substrate. An LCD panel is manufactured by interposing the liquid crystal between the color filter substrate and the TFT substrate after assembling the color filter substrate with the TFT substrate. The LCD is manufactured by assembling parts such as a lamp, a light guiding plate, a power supply device, etc., with the LCD panel.

According to the present invention, the rubbing cloth is formed by interweaving the warp with the weft having a length shorter than that of the warp, and the rubbing pile is formed on the rubbing cloth and is aligned parallel to the warp.

Accordingly, it is possible to manufacture a various size of rubbing cloth regardless of a length of the alignment film, and to increase yield of the rubbing cloth.

The present invention relates to a method for fabricating a liquid crystal display (LCD) device. More particularly, the present invention relates to an apparatus and method for rubbing an alignment layer of an LCD device, in which rubbing uniformity of the alignment layer is improved.

Generally, LCD devices are widely used for clocks, calculators, monitors for PCs, notebook computers, TVs, monitors for spacecraft, PDAs, cellular phones, etc. LCD devices are used because of their characteristics and they have the advantages of low voltage driving, low power consumption, full color, thin profile, and lightness in weight.

An LCD panel may include a thin film transistor (TFT) substrate provided with a TFT array, a color filter (CF) substrate provided with a color filter array, and a liquid crystal layer formed between the two substrates. Alignment layers may be respectively provided on each surface of the TFT substrate and the CF substrate to face each other. The alignment layers determine an alignment direction of the liquid crystal layer.

The CF substrate may include a black matrix layer that prevents light from reaching the pixel regions, R/G/B color filter layers corresponding to the respective pixel regions to display various colors, and a common electrode formed on the entire surface including the color filter layers. The common electrode may be formed on the TFT substrate in an in-plan switching (IPS) mode LCD device. An alignment process may then be performed for the alignment layers of the TFT substrate and the CF substrate to arrange liquid crystal molecules.

An example of the alignment process includes a rubbing method in which a surface of an alignment layer is rubbed with a rubbing cloth. The rubbing cloth is adhered to an outer circumference of a roller. If the roller is rotated, the rubbing cloth adhered to the outer circumference of the roller contacts the surface of the alignment layer so that the surface of the alignment layer is rubbed with the rubbing cloth.

If liquid crystal molecules are arranged along a direction of the alignment layer rubbed with the rubbing cloth, it may be possible to obtain uniform display characteristics.

FIGS. 2A to 2C illustrate a related art process for rubbing an alignment layer. FIG. 2A is a perspective view illustrating an apparatus for rubbing an alignment layer, FIG. 2B is a side view illustrating an apparatus for rubbing an alignment layer, and FIG. 2C is a plan view illustrating an apparatus for rubbing an alignment layer.

As shown in FIGS. 2A to 2C, the related art apparatus for rubbing an alignment layer includes a cylindrical rubbing roller 61, a rubbing cloth 62 adhered to an outer circumference of the rubbing roller 61 using a double-sided tape, a rotary shaft 63 connected with both sides of the rubbing roller 61 and rotated along one direction while supporting the rubbing roller 61, and a rotary motor 66 connected with the rotary shaft 63 to rotate the rotary shaft 63.

The rubbing roller 61 connected with the rotary shaft 63 contacts the alignment layer 65 of the substrate 64 loaded on the stage 60 at the bottom, and forms a groove on a surface of the alignment layer 65 while being rotated by the rotary motor 66 in one direction.

That is, the related art rubbing process is performed in such a manner that the rubbing roller 61 wound with the rubbing cloth 62 is rotated to rub the surface of the alignment layer 65 using physical friction.

In order to obtain uniform display characteristics in the LCD device, it is important that the groove is uniformly formed in a wide area. The groove can uniformly be formed by rubbing the surface of the alignment layer with the rubbing cloth at uniform pressure and speed to align a high molecular chain on the surface of the alignment layer in a certain direction.

The aforementioned related art method for rubbing an alignment layer uniformly arranges the liquid crystal molecules by rubbing the alignment layer with the rubbing cloth. The related art method also uniformly displays images on the entire surface of the LCD device by arranging the alignment layer in one direction.

However, with the trend towards larger sized LCD devices, LCD devices having dimensions of 1100 mm or greater have been commercially used. Under these circumstances, the rubbing roller used for the rubbing process is contrived to have a large size.

In this case, as shown in FIG. 3, a middle portion in a longitudinal direction of the rubbing roller 61 is bent by self-load as the rubbing roller 61 of metal material has a longer cylindrical length. Also, the alignment layer 65 formed on the substrate 64 is rubbed by uneven pressure. As a result, display quality is deteriorated over the entire surface of the LCD device.

Furthermore, for the alignment process, the rubbing roller 61 is adhered with the rubbing cloth 62 using a general adhesive. Furthermore, static electricity occurs due to friction between the rubbing cloth 62 and the alignment layer 65. Friction is caused by rotation of the rubbing roller 61. For this reason, dust, dirt in the air, and/or particles generated from the rubbing cloth 62 is adsorbed into the alignment layer 65, thereby causing a pin hole.

Accordingly, the present invention is directed to an apparatus and method for rubbing an alignment layer of an LCD device, which substantially obviates one or more problems due to limitations and disadvantages of the related art.

An advantage of the present invention is to provide an apparatus and method for rubbing an alignment layer of an LCD device, in which the alignment layer is rubbed over an entire surface of a substrate at uniform pressure.

Another advantage of the present invention is to provide an apparatus and method for rubbing an alignment layer of an LCD device, in which dust and/or particle is not adsorbed into the alignment layer during the rubbing process.

To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described, an apparatus for rubbing an alignment layer of an LCD device includes a rubbing means to rub the alignment layer while the rubbing means is rotated along one direction to contact a surface of the alignment layer formed on a substrate, and a liquid jet to jet liquid when the alignment layer is rubbed by the rubbing means.

In another aspect of the present invention, a method for rubbing an alignment layer of an LCD device includes forming the alignment layer on a substrate, rubbing the alignment layer by rotating a rubbing roller adhered with a rubbing cloth while moving the substrate provided with the alignment layer in one direction, and simultaneously jetting liquid using a liquid jet.

FIGS. 6A and 6B are side views illustrating a rubbing roller in an apparatus for rubbing an alignment layer of an LCD device according to a third exemplary embodiment of the present invention;

FIGS. 7A and 7B are perspective views illustrating a rubbing roller in an apparatus for rubbing an alignment layer of an LCD device according to the third exemplary embodiment of the present invention;

FIG. 9 illustrates a rubbing process performed when a middle portion of a rubbing roller bends when an alignment layer of an LCD according to an exemplary embodiment of the present invention is rubbed.

As shown in FIG. 4, the apparatus for rubbing an alignment layer of an LCD device according to a first exemplary embodiment of the present invention includes a cylindrical rubbing roller 101, a rubbing cloth 102 that may be adhered to an outer circumference of the rubbing roller 101 using a double-sided tape, a rotary shaft 103 connected with both sides of the rubbing roller 101, a rotary motor 104 connected with the rotary shaft 103, and a liquid jet 110. The rotary shaft 103 may rotate along one direction while supporting the rubbing roller 101 and the rotary motor 104 may rotate the rotary shaft 103 along one direction. The liquid jet 110 may jet liquid onto a substrate 100 during rotation of the rubbing roller 101.

Also, the rubbing roller 101 may include an inner cylinder of carbon fiber reinforcing plastic and an outer cylinder of plated stainless steel. A rubbing cloth is adhered to a surface of the plated stainless steel using a conductive adhesive.

The rubbing roller 101 connected with the rotary shaft 103 contacts the alignment layer 120 of the substrate 100 loaded on the stage 200 at the bottom. The rotary shaft 103 is rotated in one direction by the rotary motor 104 to rotate the rubbing roller 101. The rubbing cloth 102 adhered to the rubbing roller 101 forms a groove on a surface of the alignment layer 120.

The rubbing process is performed in such a manner that the rubbing roller 101 wound by the rubbing cloth 102 is rotated to rub the surface of the alignment layer 120 using physical friction.

As described above, the rubbing process is performed in such a manner that a groove is formed on the surface of the alignment layer 120 using the rubbing apparatus while the liquid is being jetted onto the entire surface of the substrate 100 using the liquid jet 110. The middle portion of the rubbing roller 101 is filled with the liquid even if it is bent. Therefore, it is possible to uniformly perform the rubbing process.

In the apparatus for rubbing an alignment of an LCD device according to a first exemplary embodiment of the present invention, the liquid jet 110 jets the liquid onto the substrate 100 provided with the alignment layer 120. In the apparatus for rubbing an alignment of an LCD device according to a second exemplary embodiment of the present invention, the liquid jet 110 jets the liquid onto the rubbing roller 101 adhered with the rubbing cloth 102.

As shown in FIG. 5, the apparatus for rubbing an alignment layer of an LCD device according to a second exemplary embodiment of the present invention includes a cylindrical rubbing roller 101, a rubbing cloth 102 that may be adhered to an outer circumference of the rubbing roller 101 using a double-sided tape, and a liquid jet 110. The liquid jet 110 jets liquid 114 onto the rubbing roller 101.

A method for rubbing an alignment layer using the aforementioned apparatus according to a second exemplary embodiment of the present invention will now be described.

The rubbing roller 101 connected with the rotary shaft 103 contacts the alignment layer 120 of the substrate 100 loaded on the stage 200 at the bottom. The rotary shaft 103 is rotated in one direction by the rotary motor 104 to rotate the rubbing roller 101. The rubbing cloth 102 adhered to the rubbing roller 101 forms a groove on a surface of the alignment layer 120.

The rubbing process is performed in such a manner that the liquid 114 is jetted onto the rubbing roller 101 provided with the rubbing cloth 102 using the liquid jet 110 when the alignment layer 120 is rubbed using the rubbing apparatus according to a second exemplary embodiment of the present invention.

As described above, the rubbing process is performed in such a manner that a groove is formed on the surface of the alignment layer 120 using the rubbing apparatus while the liquid is being jetted onto the rubbing roller 101 adhered with the rubbing cloth 102 using the liquid jet 110. The middle portion of the rubbing roller 101 is filled with the liquid 114 even if it is bent. Therefore, it is possible to uniformly perform the rubbing process.

FIGS. 6A and 6B are side views illustrating a rubbing roller in an apparatus for rubbing an alignment layer of an LCD device according to a third exemplary embodiment of the present invention, and FIGS. 7A and 7B are perspective views illustrating a rubbing roller in an apparatus for rubbing an alignment layer of an LCD device according to the third exemplary embodiment of the present invention.

In the apparatus for rubbing an alignment of an LCD device according to the first and second exemplary embodiments of the present invention, the liquid is jetted onto the substrate 100 provided with the alignment layer 120 or the rubbing roller 101 adhered with the rubbing cloth 102 through the jet nozzle 112 of the liquid jet 110. In the apparatus for rubbing an alignment of an LCD device according to a third exemplary embodiment of the present invention, the rubbing roller 101 may be provided with a plurality of holes 150 and may be directly connected with the pipe 113 to supply the liquid to the substrate 100 through the holes 150.

A method for rubbing an alignment layer using the aforementioned apparatus according to a third exemplary embodiment of the present invention will now be described.

The rubbing roller 101 connected with the rotary shaft 103 contacts the alignment layer 120 of the substrate 100 loaded on the stage 200 at the bottom. The rotary shaft 103 is rotated in one direction by the rotary motor 104 to rotate the rubbing roller 101. The rubbing cloth 102 adhered to the rubbing roller 101 forms a groove on a surface of the alignment layer 120.

The rubbing process is performed in such a manner that the cylindrical rubbing roller 101 wound by the rubbing cloth 102, which may be made of nylon, is rotated to rub the surface of the alignment layer 120 using physical friction.

The rubbing process is performed in such a manner that liquid is injected into the rubbing roller 101 provided with the plurality of holes 150 using the liquid jet 110 when the alignment layer 120 is rubbed using the rubbing apparatus according to a third exemplary embodiment of the present invention.

As described above, the rubbing process is performed in such a manner that if the liquid 114 is injected into the rubbing roller 101 using the liquid jet 110, the liquid flows toward the substrate 100 through the holes 150 formed in the rubbing roller 101 to form a groove on the surface of the alignment layer 120. The middle portion of the rubbing roller 101 is filled with the liquid 114 even if it is bent. Therefore, it is possible to uniformly perform the rubbing process.

In the aforementioned liquid jet 110, the liquid storage tank 111 may be externally supplied with N2gas. The liquid may then be supplied to the rubbing roller 101 through the pipe 113 if the pressure inside the liquid storage tank 111 reaches a maximum caused by the N2gas.

As shown in FIG. 8, the rubbing process of the alignment layer 120 formed on the substrate 100 is performed using the rubbing cloth 102 adhered to the rubbing roller 101 while the liquid 114 is being jetted onto the substrate 100. The rubbing process may determine the alignment direction of the liquid crystal.

FIG. 9 illustrates a rubbing process performed when a middle portion of a rubbing roller is bent when an alignment layer of an LCD according to an exemplary embodiment of the present invention is rubbed.

As shown in FIG. 9, if the middle portion of the rubbing roller 101 is downwardly bent by gravity, it is filled with the liquid 114 so as to obtain uniform alignment.

The rubbing process may be performed after the liquid is jetted onto the substrate or the rubbing cloth. The middle portion of the rubbing roller is filled with the liquid even if it is downwardly bent. Therefore, it is possible to uniformly perform the rubbing process and to prevent static electricity from occurring between the rubbing cloth and the alignment layer. Also, it is possible to reduce a defect caused by particles generated from the rubbing cloth.

On non-touch LCDs apply no pressure to the LCD surface and ensure no impact can be made by end users to it. There is no specification for pressure or impact on non-touch LC