Patent Publication Number: US-2012044345-A1

Title: Panel assembly alignment system and alignment method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Taiwan Patent Application No. 099127570, filed on Aug. 18, 2010, which is hereby incorporated by reference for all purposes as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a panel assembly system, and more particularly to a panel assembly alignment system and an alignment method thereof, capable of combining a determination technology for alignment photographing of a panel and a technology for changing a pitch between alignment patterns of a panel. 
     2. Related Art 
     In a naked-eye three-dimensional (3D) display panel in the prior art, in order to enable a left eye and a right eye of a user to receive different display signals, a color filter panel (CF panel) is usually attached to a normal cell panel, and then a slit cell/black matrix (BM) barrier is attached to the CF panel, so that the slit cell/BM barrier separates a frame signal output by the normal cell panel into display signals separately received by the left eye and the right eye. 
     However, no matter which type of slit cell/BM barrier structure is adopted, more than two times of panel assembly and attachment processes are required, such as a first assembly process in which a normal cell panel and a CF panel are combined, a second assembly process in which the CF panel and a slit cell/BM barrier are combined, a third assembly process in which other assembly elements need to be arranged between the panels, and so forth. As long as a situation of an alignment offset of a panel occurs during the assembly processes, for example, the CF panel is inclinedly attached to the normal cell panel, the assembled panel cannot completely separate the display signals capable of being received the left eye and right eye, thus lowering a quality that the panel displays a 3D optical image. 
     Next, although the manufacturers configure alignment marks on each panel to assist alignment, as a panel size is excessively large, when a slight position offset occurs in any assembly process of any panel, even if the alignment is performed according to the alignment marks, the portions far away from the alignment marks have gradually increasing offsets, and the alignment marks become completely useless. 
     Thus, the manufactures consider how to avoid or mitigate a problem that the panel cannot completely separate the display signals capable of being received by the left eye and the right eye due to alignment offsets, which causes lowering of the quality that the panel displays the 3D optical image. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a panel assembly system and a method thereof capable of adjusting a pitch between alignment patterns of a panel, so as to complete assembly of a liquid crystal panel while maintaining a 3D viewing angle effect thereof. 
     To solve the above-mentioned problems, the invention provides a panel assembly alignment system, which comprises a plurality of first alignment patterns, a plurality of second alignment patterns, a plurality of third alignment patterns, an element placement unit, at least one photographing unit, and an operation unit. 
     The first alignment patterns are formed into a geometric pattern, and arranged at a calibration area of a first panel at equal pitches outwardly from a center of the geometric pattern; the second alignment patterns are formed into the geometric pattern and arranged at a calibration area of a second panel with a pitch between the adjacent second alignment patterns on a same straight line being wider as positions of the second alignment patterns are farther away from the center of the geometric pattern; the third alignment patterns are formed into the geometric pattern and arranged at a calibration area of a third panel with a pitch between the adjacent third alignment patterns on a same straight line being narrower as positions of the third alignment patterns are farther away from the center of the geometric pattern; the element placement unit is used for placing the first panel, the second panel, and the third panel in sequence, wherein the first alignment patterns correspond to the second alignment patterns, and the second alignment patterns correspond to the third alignment patterns; the at least one photographing unit is used for photographing alignment of the first alignment patterns and the second alignment patterns to form a first image, and continuously photographing alignment of the second alignment patterns and the third alignment patterns to form a second image; and the operation unit is used for acquiring the first image, so as to find out at least one first overlap pattern and at least one second overlap pattern overlapped with each other from the first alignment patterns and the second alignment patterns, and find out an offset direction of the second panel corresponding to the first panel, and overlapping at least one third overlap pattern conforming to the offset direction in the third alignment patterns with the second overlap pattern when controlling the element placement unit to place the third panel according to the second image. 
     To solve the above-mentioned problems, the invention provides a panel assembly alignment method, which comprises: placing a first panel on a carrying platform, wherein a plurality of first alignment patterns is arranged to form a geometric pattern and arranged at a calibration area of the first panel at equal pitches outwardly from a center of the geometric pattern; placing a second panel on the first panel, so the first alignment patterns correspond to a plurality of second alignment patterns of the second panel, the second alignment patterns are arranged to form the geometric pattern, and arranged at a calibration area of the second panel with a pitch between the adjacent second alignment patterns on a same straight line being wider as positions of the second alignment patterns are farther away from the center of the geometric pattern; finding out at least one first overlap pattern and at least one second overlap pattern overlapped with each other and an offset direction of the second panel corresponding to the first panel from the first alignment patterns and the second alignment patterns, so as to find out at least one third overlap pattern from a plurality of third alignment patterns of a third panel, wherein the third alignment patterns are arranged to form the geometric pattern, and arranged at a calibration area of the third panel with a pitch between the adjacent third alignment patterns on a same straight line being narrower as positions of the third alignment patterns are farther away from the center of the geometric pattern; and placing the third panel on the second panel, so the at least one third overlap pattern is overlapped with the at least one second overlap pattern. 
     The present invention is characterized in that the present invention is applicable to assembly processes of various slit cell/BM barrier structures, and assembly times are not limited. Next, when an alignment offset of the panel occurs during the assembly processes, the problem of the alignment offset of each panel can be modified by using improved alignment patterns in combination with a photographing alignment technology, so that the assembled panel can completely separate display signals capable of being received by a left eye and a right eye, thus improving a quality that the panel displays a 3D optical image, further, the present invention is applicable to an assembly process of a large-scale panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein: 
         FIGS. 1A and 1B  are schematic views of architecture of a panel assembly alignment system according to an embodiment of the present invention; 
         FIGS. 2A and 2B  are schematic views of arrangement of alignment patterns of a first panel according to an embodiment of the present invention; 
         FIGS. 2C and 2D  are schematic views of arrangement of alignment patterns of a second panel according to an embodiment of the present invention; 
         FIGS. 2E and 2F  are schematic views of arrangement of alignment patterns of a third panel according to an embodiment of the present invention; 
         FIGS. 2G to 2I  are schematic views of a pitch between alignment patterns of each panel according to an embodiment of the present invention; 
         FIG. 3A  is a schematic view of ideal overlap of alignment patterns according to an embodiment of the present invention; 
         FIG. 3B  is a schematic view of content of a first image according to an embodiment of the present invention; 
         FIG. 3C  is a schematic view of selection of third overlap patterns according to an embodiment of the present invention; 
         FIG. 3D  is a schematic view of content of a second image according to an embodiment of the present invention; 
         FIG. 4A  is another schematic view of content of a first image according to an embodiment of the present invention; 
         FIG. 4B  is schematic view of another selection of third overlap patterns according to an embodiment of the present invention; 
         FIG. 4C  is another schematic view of content of a second image according to an embodiment of the present invention; 
         FIGS. 5A and 5B  are schematic views of another architecture of a panel assembly alignment system according to an embodiment of the present invention; 
         FIG. 6A  is a schematic flow chart of a panel assembly alignment method according to an embodiment of the present invention; and 
         FIG. 6B  is a detailed schematic flow chart of a process in  FIG. 6A  according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The preferred embodiments of the present invention are illustrated below in detail with reference to the accompanying drawings. 
       FIGS. 1A and 1B  are schematic views of architecture of a panel assembly alignment system according to an embodiment of the present invention.  FIGS. 2A and 2B  are schematic views of arrangement of alignment patterns of a first panel according to an embodiment of the present invention.  FIGS. 2C and 2D  are schematic views of arrangement of alignment patterns of a second panel according to an embodiment of the present invention.  FIGS. 2E and 2F  are schematic views of arrangement of alignment patterns of a third panel according to an embodiment of the present invention.  FIGS. 2G to 2I  are schematic views of a pitch between alignment patterns of each panel according to an embodiment of the present invention. In this embodiment, assembly processes of panels of three layers are illustrated. A first panel  41  at a bottom layer is a normal cell panel, a second panel  42  at a middle layer is a CF panel, and a third panel  43  at an upper layer is a slit cell/BM barrier. 
     As shown in  FIGS. 2A ,  2 B, and  2 G, the first panel  41  includes a calibration area  411  at a periphery thereon. A plurality of first alignment patterns  51  is arranged on the calibration area  411 . The first alignment patterns  51  form a geometric pattern for positioning, here the geometric pattern is, for example, a cross arranged by two straight lines being interlaced and perpendicular to each other, but the present invention is not limited herein. 
     The first alignment patterns  51  are outwardly arranged starting with a first alignment pattern  511  at a center of the cross, in which a pitch between every two adjacent first alignment patterns  51  is the same. It should be noted that the pitch here means a distance between centers of every two alignment patterns, and may also be calculated according to outer sidelines at a periphery of the alignment patterns. Here, each pitch is R. 
     As shown in  FIGS. 2C ,  2 D, and  2 H, the second panel  42  also includes a calibration area  421  at a periphery thereon. A plurality of second alignment patterns  52  is arranged on the calibration area  421 . The second alignment patterns  52  form a geometric pattern similar to the cross formed by the first alignment patterns  51 , and are arranged outwardly in a distributed manner starting with a second alignment pattern  521  at the center of the cross. However, it is different from the first alignment patterns  51  that the two adjacent second alignment patterns  52  on the same straight line are arranged with a pitch being wider as arrangement positions are closer to outside (second alignment patterns  521  being farther away from the center). In other words, except for the second alignment pattern  521  at the center, a pitch between the second alignment pattern  52  and a previous-level second alignment pattern  52  (the second alignment pattern  521  being closer to the center) is smaller than a pitch between the second alignment pattern  52  and a next-level second alignment pattern  52  (being farther away from the center point) by a preset distance. 
     Here, the second alignment pattern  521  at the center point is regarded as a first-level second alignment pattern, an adjacent second alignment pattern  52  at a periphery thereof is regarded as a second-level second alignment pattern  522 , and an alignment pattern at a periphery of the second-level second alignment pattern  522  is a third-level second alignment pattern  523 . The pitch between the first-level second alignment pattern (the second alignment pattern  521  at the center point) and the second-level second alignment pattern  522  is R, and the preset distance is 1, so that the pitch between the second-level second alignment pattern  522  and the third-level second alignment pattern  523  is R+1, the pitch between the third-level second alignment pattern  523  and a fourth-level second alignment pattern  524  is R+2, and so forth. 
     As shown in  FIGS. 2E ,  2 F, and  2 I, the third panel  43  also includes a calibration area  431  at a periphery thereon. A plurality of third alignment patterns  53  is arranged on the calibration area  431 . The third alignment patterns  53  form a geometric pattern similar to the cross formed by the first alignment patterns  51 , and are arranged outwardly in a distributed manner starting with a third alignment pattern  531  at the center of the cross. However, it is different from the first alignment patterns  51  that the two adjacent third alignment patterns  53  on the same straight line are arranged with a pitch being narrower as arrangement positions are closer to outside (the third alignment patterns  531  being farther away from the center). In other words, except for the third alignment pattern  531  at the center, a pitch between each third alignment pattern  53  and a previous-level third alignment pattern  53  (a third alignment pattern  531  being closer to the center) is larger than a pitch between the third alignment pattern  53  and a next-level third alignment pattern  53  (a third alignment pattern  531  being farther away from the center) by a preset distance. However, the preset distance is not limited to 1. 
     Here, the third alignment pattern  531  at the center is a first-level third alignment pattern, an adjacent third alignment pattern  53  at a periphery thereof is a second-level third alignment pattern  532 , and an alignment pattern at a periphery of the second-level third alignment pattern  532  is a third-level third alignment pattern  533 . The pitch between the first-level third alignment pattern (the third alignment pattern  531  at the center) and the second-level third alignment pattern  532  is R, and the preset distance is 1, so that the pitch between the second-level third alignment pattern  532  and the third-level third alignment pattern  533  is R−1, the pitch between the third-level third alignment pattern  533  and the fourth-level third alignment pattern  534  is R−2, and so forth. 
     As shown in  FIG. 1A , an operation unit  10  first controls an element placement unit  30  to acquire the first panel  41  and then place the first panel  41  on a carrying platform  11 . After the first panel  41  is placed, the operation unit  10  controls at least one photographing unit  20  to photograph an alignment situation between the first panel  41  and the second panel  42 , that is, to photograph an overlap status between the first alignment pattern  51  and the second alignment pattern  52 , so as to form a first image. It should be noted here that the element placement unit  30  can be an element removal and placement device or component for grasping and sucking a panel, such as a hollow suction cup or a mechanical manipulator. However, the present invention is not limited herein, and any device capable of performing panel removal or placement is applicable. The photographing unit  20  is connected through a movable table or a movable lever  12 . The movable lever  12  is then controlled by the operation unit  10  to move the photographing unit  20 , so the photographing unit  20  can move according to a specific track. However, the technologies that the photographing unit  20  moves the panel in combination with the movable lever  12  and the element placement unit  30  exist in the prior art and are well known to persons of ordinary skill in the technical field of the present invention, so the technologies are shown with simplified diagrams and are not illustrated here. 
       FIG. 3A  is a schematic view of ideal overlap of alignment patterns according to an embodiment of the present invention.  FIG. 3B  is a schematic view of content of a first image according to an embodiment of the present invention.  FIG. 3C  is a schematic view of selection of a third overlap pattern according to an embodiment of the present invention.  FIG. 3D  is a schematic view of content of a second image according to an embodiment of the present invention. As shown in  FIG. 3A , when the first panel  41  and the second panel  42  are overlapped, the most ideal overlap situation is that the first alignment pattern  511  at the center of the cross is overlapped with the second alignment pattern  521  at the center. However, practical alignment situations are different from the ideal situation. 
     As shown in  FIGS. 1A and 3B , the operation unit  10  acquires a first image, and analyzes at least one first overlap pattern and at least one second overlap pattern overlapped with each other in all the first alignment patterns  51  and the second alignment patterns  52 . As shown in  FIG. 3B , it is assumed that when the first panel  41  and the second panel  42  are overlapped, the second panel  42  has a slight offset, so the overlapped alignment patterns are the third-level first alignment pattern  513  and the third-level second alignment pattern  523 , and an offset direction is −X, which represents that the first overlap pattern is the third-level first alignment pattern  513  in the −X direction, and the second overlap pattern is the third-level second alignment pattern  523  in the −X direction, that is, the two alignment patterns inside a dotted-line circle. 
     As shown in  FIG. 3C , the operation unit  10  analyzes which one among all the third alignment patterns  53  is the third overlap pattern corresponding to the first overlap pattern and second overlap pattern. As for this example, the operation unit  10  analyzes that the third-level third alignment pattern  533  in the offset direction −X is the qualified third overlap pattern. 
     As shown in  FIGS. 1B and 3D , the operation unit  10  controls the photographing unit  20  to continuously photograph an overlap position between the first overlap pattern and the second overlap pattern, so as to form a second image. The operation unit  10  then controls the element placement unit  30  to place the third panel  43  on the second panel  42 . When the third panel  43  is placed, the operation unit  10  analyzes a current alignment status of the panel according to the continuously generated second images, so the qualified third overlap pattern is overlapped with the second overlap pattern, such that the liquid crystal panel presents a display offset angle of the frame after adjustment of the panel assembly. 
     The photographing unit  20  photographs overlaps of the alignment patterns one by one by using arrangement of straight lines of the cross (no matter the first alignment pattern or the second alignment pattern is used as a reference) as a movement track. For  FIGS. 1A and 3B , the photographing unit performs displacement photographing in an X-axis direction and a Y-axis direction (having no precedence order). Afterwards, the operation unit  10  analyzes an overlap degree between the first alignment pattern  51  and the second alignment pattern  52  at the same level by using the first alignment pattern  51  as a reference, finds out the first overlap pattern and the second overlap pattern overlapped with each other, and finds out an offset direction of the second panel  42  corresponding to the first panel  41 . 
       FIG. 4A  is another schematic view of content of a first image according to an embodiment of the present invention.  FIG. 4B  is schematic view of another selection of a third overlap pattern according to an embodiment of the present invention.  FIG. 4C  is another schematic view of content of a second image according to an embodiment of the present invention. 
     As shown in  FIGS. 1A and 4A , the operation unit  10  acquires a first image, and analyzes at least one first overlap pattern and at least one second overlap pattern overlapped with each other in all the first alignment patterns  51  and the second alignment patterns  52 . As shown in  FIG. 4A , it is assumed that when the first panel  41  and the second panel  42  are overlapped, the second panel  42  has a slight offset, so the overlapped alignment patterns are a fourth-level first alignment pattern  514  and a fourth-level second alignment pattern  524 , and an offset direction is Y, which represents that the first overlap pattern is the fourth-level first alignment pattern  514  in Y direction, and the second overlap pattern is the fourth-level second alignment pattern  524  in the Y direction, that is, the two alignment patterns inside a dotted-line circle. 
     As shown in  FIG. 4B , the operation unit  10  analyzes which one among all the third alignment patterns  53  is a third overlap pattern corresponding to the first overlap pattern and the second overlap pattern. As for this example, the operation unit  10  analyzes that the fourth-level third alignment pattern  534  in the offset direction Y is the qualified third overlap pattern. 
     As shown in  FIGS. 1B and 4C , the operation unit  10  controls the photographing unit  20  to continuously photograph an overlap position between the first overlap pattern and the second overlap pattern, so as to form a second image. The operation unit  10  then controls the element placement unit  30  to place the third panel  43  on the second panel  42 . When the third panel  43  is placed, a current alignment status is analyzed according to the continuously generated second images, so the qualified third overlap pattern is overlapped with the second overlap pattern, such that the liquid crystal panel presents a display offset angle of the frame after adjustment of the panel assembly. 
     Similarly, the offset direction of the second panel  42  corresponding to the first panel  41  is an X direction or a −Y direction, and the corresponding third overlap pattern also needs to be found out in this mode, so as to control and adjust an offset direction of the third panel  43  placed on the second panel  42 . 
     In addition, the first alignment pattern  51 , the second alignment pattern  52 , and the third alignment pattern  53  are the same, the second alignment pattern  52  is larger than the third alignment pattern  53 , and a size of the first alignment pattern  51  is between sizes of the second alignment pattern  52  and third alignment pattern  53 , but the present invention is not limited herein. 
       FIGS. 5A and 5B  are schematic views of another architecture of a panel assembly alignment system according to an embodiment of the present invention. It is different from the architecture views shown in  FIGS. 1A and 1B  that a plurality of the photographing unit exists in this system, and two photographing units are taken as an example for illustration here. 
     In this embodiment, a first photographing unit  21  performs displacement photographing in an X-axis direction, and a second photographing unit  22  performs displacement photographing in a Y-axis direction. However, the pattern design and the size of the alignment pattern may cause that a group of overlap patterns exists in different axial directions, so the operation unit  10  acquires one or two groups of overlap patterns during determination of overlap patterns. 
     If two groups of overlap patterns exist, the operation unit  10  analyzes two third alignment patterns  53  conforming to the overlap pattern demand in the third alignment patterns  53 , for serving as the third overlap patterns. Afterwards, the operation unit  10  controls the element placement unit  30  to place the third panel  43  on the second panel  42 , and when the third panel  43  is placed, a current alignment offset status of the panel is analyzed according to the continuously generated second images, so the two qualified third overlap patterns are overlapped with two corresponding second overlap patterns, such that the liquid crystal panel presents a display offset angle of the frame after adjustment of the panel assembly. 
       FIG. 6A  is a schematic flow chart of a panel assembly alignment method according to an embodiment of the present invention, and  FIG. 6B  is a detailed schematic flow chart of the process in  FIG. 6A  according to an embodiment of the present invention. For ease of understanding, please refer to  FIGS. 1A and 5B  at the same time. The process of the method is described as follows. 
     A first panel  41  is placed on a carrying platform  11 . A plurality of first alignment patterns  51  is arranged to form a geometric pattern and is arranged at a calibration area  411  of the first panel  41  at equal pitches outwardly from a center of the geometric pattern (Step S 110 ). The first panel  41  includes a calibration area  411  at a periphery thereon. A plurality of first alignment patterns  51  is arranged on the calibration area  411 . The first alignment patterns  51  form a shape for positioning. Here, a cross arranged by two straight lines being interlaced and perpendicular to each other is taken as an example, but the present invention is not limited herein. The first alignment pattern  51  is outwardly arranged starting with the first alignment pattern  511  at a center of the cross, and a pitch between every two adjacent first alignment patterns  51  is the same. It should be noted that here the pitch is a distance between centers of every two alignment patterns, and may also be calculated with outer sidelines at a periphery of the alignment patterns. Here, the pitch is R. The operation unit first controls the element placement unit to acquire the first panel, and places the first panel  41  on the carrying platform  11 . 
     A second panel  42  is placed on the first panel  41 , so the first alignment patterns  51  correspond to the plurality of second alignment patterns  52  of the second panel  42 . The second alignment patterns  52  are arranged to form the geometric pattern, and arranged at a calibration area  421  of a second panel  42  with a pitch between adjacent second alignment patterns  52  on the same straight line being wider as positions of the adjacent second alignment patterns  52  farther away from the center of the geometric pattern (Step S 120 ). 
     The second panel  42  also includes a calibration area  421  at a periphery thereon. A plurality of second alignment patterns  52  is arranged on the calibration area  421 . The second alignment patterns  52  form a pattern similar to a cross formed by the first alignment patterns  51 , and are arranged outwardly starting with the second alignment pattern  521  at the center of the cross. The two adjacent second alignment patterns  52  on the same straight line are arranged with a pitch being wider as arrangement positions are closer to outside (farther away from the center point of the cross). In other words, except for the second alignment pattern  521  at the center, a pitch between each second alignment pattern  52  and a previous-level second alignment pattern  52  (the second alignment pattern  521  being closer to the center) is smaller than a pitch between the second alignment pattern  52  and a next-level second alignment pattern  52  (the second alignment pattern  521  being farther away from the center) by a preset distance. 
     The operation unit  10  controls the element placement unit  30  to place the first panel  41  on the carrying platform  11 , and then controls the at least one photographing unit  20  to photograph an overlap status between the first alignment pattern  51  and the second alignment pattern  52 , so as to form a first image. 
     At least one first overlap pattern and at least one second overlap pattern overlapped with each other and an offset direction of the second panel  42  corresponding to the first panel  41  are found out from the first alignment patterns  51  and second alignment patterns  52 , so as to find out at least one third overlap pattern from a plurality of third alignment patterns  53  of a third panel  43 . The third alignment patterns  53  are also arranged to form the geometric pattern, and are arranged at a calibration area  431  of a third panel  43  with a pitch between adjacent third alignment patterns  53  on the same straight line being narrower as positions of the third alignment patterns  53  are farther away from the center of the geometric pattern (Step S 130 ). The operation unit  10  acquires a first image, and analyzes at least one first overlap pattern and at least one second overlap pattern overlapped with each other in all the first alignment patterns  51  and the second alignment patterns  52 . 
     However, the method for analyzing the overlap of the alignment patterns is described as follows. 
     An overlap degree between the first alignment pattern  51  and the second alignment pattern  52  arranged on the same straight line and at the same level is analyzed (Step S 131 ). The photographing unit  20  photographs overlaps of the alignment patterns one by one by using arrangement of straight lines of a cross (no matter the first alignment patterns or the second alignment patterns) as a movement track. The first image formed through photographing is received by the operation unit  10 , and the overlap degree between the first alignment pattern  51  and the second alignment pattern  52  at the same level is analyzed. 
     A first overlap pattern and a second overlap pattern having the highest overlap degree are found out (Step S 132 ). The operation unit  10  may analyze the first alignment pattern  51  and the second alignment pattern  52  having the highest overlap degree and at the same level, for serving as the first overlap pattern and the second overlap pattern. Afterwards, according to an overlap position between the first overlap pattern and the second overlap pattern, an offset direction of the second panel  42  corresponding to the first panel  41  is determined (Step S 133 ). Taking  FIG. 3B  as an example, the operation unit  10  determines that the third-level first alignment pattern  513  and the third-level second alignment pattern  523  in the −X direction are overlapped with each other, and recognizes that the offset direction of the second panel  42  corresponding to the first panel  41  is −X. Further, taking  FIG. 4C  as an example, the operation unit  10  determines that the fourth-level first alignment pattern  514  and the fourth-level second alignment pattern  524  in the Y direction are overlapped with each other, and recognizes that the offset direction of the second panel  42  corresponding to the first panel  41  is Y. 
     The third panel  43  is placed on the second panel  42 , so the third overlap pattern is overlapped with the second overlap pattern (Step S 140 ). The operation unit  10  analyzes which one among all the third alignment patterns  53  is a third overlap pattern corresponding to the first overlap pattern and the second overlap pattern. Afterwards, the operation unit  10  controls the photographing unit  20  to continuously photograph an overlap position between the first overlap pattern and the second overlap pattern, so as to form a second image. The operation unit  10  then controls the element placement unit  30  to place the third panel  43  on the second panel  42 . When the third panel  43  is placed, according to the continuously generated second images, the current alignment status of the panel is analyzed, so the qualified third overlap pattern is overlapped with the second overlap pattern, such that the liquid crystal panel presents a display offset angle of the frame after adjustment of the panel assembly. 
     In conclusion, only the implementation modes or embodiments for presenting the technical means for solving the problems of the present invention are recorded, which are not intended to limit the patent scope of the present invention. All the equivalent changes and modifications that accord with the meanings of the patent scope of the present invention or that are made according to the patent scope of the present invention should fall within the scope of the present invention.