Abstract:
The present invention is method of liquid crystal alignment for a flexible LCD with micro-grooves comprising: coating a thermoplastic material onto a conductive film; heat embossing a plurality of micro-grooves formed by a mold, wherein the surface of said mold forms said plurality of micro-grooves; and aligning said plurality of micro-grooves with an aligning wall and grooves. The present invention also adds a plurality of liquid alignment technology in roll-to-toll micro cell LCD processes. The plurality of liquid alignment technology lets the micro cells of the LCD from without aligning with an alignment LCD mode (such as TN, VA or horizontal alignment) and achieves a better contrast and display quality.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method of liquid crystal alignment for a flexible LCD with micro-grooves added to a plurality of liquid alignment technology in a roll-to-roll micro cell LCD process to make a flexible LCD with micro-grooves. 
     2. Description of Related Art 
     LCD monitors are rapidly replacing CRT monitors and becoming indispensable peripheral products in computer and electronic products. 
     LCD monitor process technology is continual improving, such as the change from hard silicon or glass substrate to flexible or thin metallic substrate, capable of making assorted flexible display with bent curves and big area micro-electronic products. The roll-to-roll print process is used when making large flexible display products such as electronic paper or electronic books. 
     In the prior technology, Sipix Corporation used embossing technology and a process method of roll-to-roll to make micro-cup architecture, injecting polymer dispersed liquid crystals without alignment. Finally, with a contrast of about 10-20, the flexible LCD is finished after the sealing process. The micro-cup architecture of the flexible LCD could not align; it could only be used in scattering mode because of the lack of contrast. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method of liquid crystal alignment for a flexible LCD with micro-grooves comprising: coating of a thermoplastic material on a conductive film; thermal embossing a plurality of micro-grooves and wall from a mold, wherein the surface of said mold forms said plurality of micro-grooves and wall; and forms an aligning micro cell structure. 
     The present invention also provides a plurality of liquid alignment technology in the roll-to-roll micro cell LCD processes. The plurality of liquid alignment technology lets the micro cells of the LCD formed without aligning in LCD mode (such as TN, VA or horizontal alignment) and achieves a better contrast and display quality. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various objectives and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings, in which: 
         FIG. 1  is a process flow of embossed micro-grooves and spacing wall of the present invention; 
         FIG. 1A  is a detail of part A of  FIG. 1 ; 
         FIG. 1B  is a detail of part B of  FIG. 1 ; 
         FIG. 1C  is another detail of part B of  FIG. 1 ; 
         FIG. 2  is a flowchart of the method aligning the embossed micro-grooves and spacing wall of the present invention; 
         FIG. 3  is a process flow of UV embossed micro-grooves and wall of the present invention; 
         FIG. 4  is a flowchart of the method of UV embossed micro-grooves and wall of the present invention; 
         FIG. 5  is a process flow of making micro-grooves and wall with a gray scale mask of the present invention; 
         FIG. 5A  is a detail of part A of  FIG. 5 ; 
         FIG. 5B  is another detail of part A of  FIG. 5 ; 
         FIG. 6  is a flowchart of the method of aligning used when making micro-grooves and wall with a gray scale mask of the present invention; 
         FIG. 7  is a process flow of printing alignment material and molding wall structures with a roller of the present invention; 
         FIG. 7A  is a detail of part A of the  FIG. 7 ; 
         FIG. 7B  is a top-view chart of the bottom of the  FIG. 7A ; 
         FIG. 8  is a flowchart of printing alignment material and molding wall structures of the present invention; 
         FIG. 9  is a process flow of printing photo alignment material and molding wall structures with the roller of the present invention; 
         FIG. 10  is a flowchart showing the method of printing photo alignment material and molding wall structures with the roller of the present invention; 
         FIG. 11  is a process flow of making aligning micro cell structure with polarized ultraviolet light of the present invention; 
         FIG. 12  is a flowchart of making aligning micro cell structure with polarized ultraviolet light of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Currently, most manufacturers use the micro-cup with polarization rays alignment technology of the LCD mode (as VA, TN or Homogeneous) to produce flexible LCDs. 
       FIG. 1  shows a process flow for embossed micro-grooves and spacing wall of the present invention comprising a thermoplastic material  10 , a conductive film  12  and a mold  14 .  FIG. 1A  shows a detail of part A of the  FIG. 1 . The surface of the mold includes a plurality of micro-grooves  16 . The thermoplastic material  10  is embossed and heated to form said plurality of micro-grooves and wall of the mold  14  simultaneously.  FIG. 1B  shows a detail of part B of the  FIG. 1 .  FIG. 1B  is said plurality of micro-grooves after being embossed.  FIG. 1C  shows a detail of another part B of the  FIG. 1 .  FIG. 1C  shows another plurality of micro-grooves  36  after being embossed. Another plurality of micro-grooves is a plurality of protrusions. 
       FIG. 2  shows a flowchart of a method of aligning the embossed micro-grooves and wall of the present invention, comprising: coating a thermoplastic material on a conductive film (S 100 ); heat embossing a plurality of micro-grooves and wall formed by a mold (S 102 ); wherein the surface of said mold with said plurality of micro-grooves is formed and located inside a plurality of display locations and forming said plurality of spacing wall for supporting cell gap and micro-groove for aligning LC (S 104 ). 
       FIG. 3  shows a process flow of embossing micro-grooves and wall with ultraviolet light according to the present invention, comprising an ultraviolet seal material  18 , a conductive film  12 , a mold  14  and ultraviolet light  20 . Wherein the surface of the mold is a plurality of micro-grooves  16 . The ultraviolet seal material is embossed and the ultraviolet light and the mold  14  simultaneously forms said plurality of spacing wall for supporting cell gap and micro-groove for aligning LC. 
       FIG. 4  shows a flowchart of a method aligning the embossed micro-grooves and wall with ultraviolet light according to the present invention, comprising: coating an photo-curable polymer material on a conductive film (S 200 ); embossing a plurality of micro-grooves and wall formed by mold (S 202 ), wherein the surface of said mold and said plurality of micro-grooves is formed and located inside a plurality of display locations; sealing said plurality of micro-grooves and wall exposures by a plurality of ultraviolet light (S 204 ); forming said plurality of spacing wall for supporting cell gap and micro-groove for aligning LC (S 206 ). 
       FIG. 5  shows a process flow of making micro-grooves and wall with a gray scale mask of the present invention, comprising a photo resistant layer, a conductive film  12 , a light source  20  and a gray scale mask  22 . The photo resistant layer through said light source  20  and said gray scale mask  22  makes said plurality of micro-grooves  16 .  FIG. 5A  shows a detail of part A of the  FIG. 5 .  FIG. 5B  shows another detail of part A of the  FIG. 5 .  FIG. 5B  shows another plurality of micro-grooves  36  after being embossed. In this embodiment they are a plurality of protrusions. The photo resistant layer develops said plurality of micro-grooves by a development process  24 . Finally, after being developed, said plurality of micro-grooves is sealed by a baking process  26 . 
       FIG. 6  shows a flowchart of a method of making the micro-grooves and wall with a gray scale mask according to the present invention, comprising: coating a photo resistant layer on a conductive film (S 300 ); exposing said photo resistant layer and using a gray mask to form a plurality of micro-grooves and wall (S 302 ); developing said plurality of micro-grooves and wall formed after said exposure processed (S 304 ), wherein said exposure rays are photolithographic; baking said plurality of micro-grooves to seal a plurality of micro-grooves and wall (S 306 ), wherein said plurality of micro-grooves is located inside a plurality of display locations; forming said plurality of spacing wall for supporting cell gap and micro-groove for aligning LC (S 308 ). 
       FIG. 7  shows a process flow of making micro-grooves with a rubber roller of the present invention, comprising a thermoplastic material  10 , a conductive film  12 , gravure  28  and a roller aligner  30 . Wherein the surface of the roller structure of the gravure  28  is a hollowed out pit and sets an alignment solvent injection apparatus  280  inside said pit.  FIG. 7A  shows a detail of part A of the  FIG. 7 . The pits of the roller structure are injected with an alignment material  282 . The thermoplastic material  10  thermal embosses micro-cell walls and applies pressure to said gravure  28  simultaneously. The pit of the roller structure injects said alignment material inside said micro-cell. Wherein the surface of the pit of the roller structure includes a porous film.  FIG. 7B  shows a top-view chart of the bottom of the  FIG. 7A . The plurality of micro-cells with the aligned alignment material is formed by the process of roller rubbing alignment. 
       FIG. 8  shows a flowchart of a method of alignment when making micro-grooves with the rubber roller of the present invention, comprising: coating a thermoplastic material on a conductive film (S 400 ); thermal embossing a wall structure by a mold (the mold is a hollow structure filled with an alignment material (S 402 ); applying pressure to squeeze the alignment material out from the mold while thermal embossing the wall structure (S 404 ), wherein said surfaces of the pits of the roller structure include a porous film; printing the photo-alignment solvent onto the display locations of the micro-grooves (S 406 ); aligning the alignment material in the display locations by friction (S 408 ); and completing the micro-grooves having an alignment function (S 410 ). 
       FIG. 9  shows a process flow of making micro-grooves with the rubber roller of the present invention, comprising thermoplastic material  10 , conductive film  12 , a gravure  28 , ultraviolet light  32  and a polarization mask  34 . The surface of the roller structure of the gravure  28  is a hollowed out pit and an alignment material injection apparatus  280  injects a plurality of photo-alignment material  282  inside the space of said pit. The thermoplastic material  10  thermal embosses the micro-cell walls and applies pressure to said gravure  28  simultaneous. The pit of the roller structure injects said photo-alignment material inside said micro-cells. The polarized ultraviolet light exposure said plurality of photo-alignment material inside said micro-cells and forms said plurality of aligned micro-cells. 
       FIG. 10  shows a flowchart of a method of alignment when making aligned micro-cell with the rubber roller of the present invention, comprising: coating a thermoplastic material onto a conductive film (S 500 ); thermal embossing a wall structure by a mold (the mold is a hollow structure filled with an alignment material (S 502 ); applying pressure to squeeze the alignment material out from the mold while thermal embossing the wall structure (S 504 ), wherein said photo-alignment solvent is a photo-alignment material, and the surface of the pit of the roller structure includes a porous film; printing the photo-alignment solvent onto the display locations of the micro-grooves (S 506 ); completing the photo-aligning by using ultraviolet light and linear polarization mask. (S 508 ); and completing the micro-cells having an alignment function (S 510 ). 
       FIG. 11  shows a process flow of making aligned micro-cells with polarization ultraviolet light according to the present invention, comprising ultraviolet seal material  18 , conductive film  12 , a mold  14 , polarized ultraviolet light  32  and a polarization mask  34 . The photo curable material  18  is embossed by said mold  14 . At this stage the surface ultraviolet seal material  18  that is aligned with the polarization ultraviolet light  32  becomes solid. The sections of the photo curable material  18  that were aligned with the polarization ultraviolet light  32 , and therefore protected by the polarization mask  34 , remain flexible. In this way, a plurality of aligned micro-cell is formed. 
       FIG. 12  shows a flowchart of a method of making aligned micro-cell with polarized ultraviolet light according to the present invention, comprising: coating a photo-curable polymer onto a conductive film (S 600 ); producing a micro-cell structure by a mold, and completing the solidification and alignment by UV light and linear polarization mask (S 602 ), wherein the surface of said mold forms said plurality of micro-cells; and Completing the micro-cells having an alignment function. (S 604 ). 
     To sum up, the alignment technology and micro-cells are integrated into the roll-to-roll process. Thus, a flexible LCD is made for a lower cost and with a better display quality. 
     Although the present invention has been described with reference to the preferred embodiments thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.