Abstract:
A conveyor apparatus including a control module, an unwinding module, at least one tension sensing module, and a rewinding module is provided. The tension sensing module includes a load cell disposed between a set of rollers. An objet is conveyed along a conveying direction perpendicular to an axis of the roller. A wrap angle is formed by the object and the roller with a fulcrum of the loadi cell served as a center, and the wrap angle is less than 180°. The rewinding and unwinding modules have different actuating units electrically connected to the control module respectively, such that the object is wound or unwound by the rewinding and the unwinding modules.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority benefits of U.S. provisional application Ser. No. 61/719,510, filed on Oct. 29, 2012 and Taiwan application serial no. 101149584, filed on Dec. 24, 2012. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification. 
     
    
     BACKGROUND OF THE DISCLOSURE 
       [0002]    1. Field of the Disclosure 
         [0003]    The disclosure generally relates to a conveyor apparatus. 
         [0004]    2. Description of Related Art 
         [0005]    Glasses can be bent when the thickness is decreased to a certain degree and formed a flexible glass having properties of flexibility and high hardness, and become applicable to planar substrates for electronic papers (e-Paper), and protecting covers, contact sensing devices, solid state light emitting devices, electronic devices and the like for photovoltaic modules. 
         [0006]    The materials of flexible substrates can also be glasses, polymers, metals or the like in the application. 
         [0007]    Presently, thin glasses can be conveyed by the application of roll-to-roll method. Although the flexible glasses already have a certain degree of flexibility due to the ultra-thin thickness, they still have hard and brittle properties, and thus the strength of the flexible glasses may be reduced 2 to 4 times because of the stress concentration generated due to the micro-crack on edge, surface crack or scratch. Any unstable conveying force or force of dragging and torsion may cause the thin glass to be broken. Two important issues have to be solved when the flexible glasses are conveyed by using the roll-to-roll method, then the possibility of breakage of the flexible glasses during conveying can be reduced. One issue is the overstress including over-tension and conveying misalignment during conveying process of the flexible glasses, and the other issue is the stress fluctuation of the flexible glasses being repeatedly subjected to tension force and compression force. 
         [0008]    The misalignment of flexible glasses during conveying process may lead to wavy winding, knurl or being disorder of side edge of the substrates, wrinkling or even breakage when the flexible substrates are wound. Moreover, for the flexible high-precision electronic products, since the misalignment of the flexible substrate during the conveying process restricts high-precision manufacturing process to be fulfilled, high-precision requirement cannot be satisfied. 
         [0009]    Since in the roll-to-roll production line the flexible substrates have to be conveyed and changed directions by using a plurality of rollers, the flexible substrates are usually sandwiched and wound among the rollers. Then, the upper and lower surfaces of the flexible substrates are contact with the rollers and the upper and lower surfaces of the flexible substrates are subjected to the tensile and compressive forces. Thus, the flexible substrates may be taken fluctuated tensile and compressive stress and broken. 
       SUMMARY OF THE DISCLOSURE 
       [0010]    The disclosure provides a conveyor apparatus capable of preventing the upper and lower surfaces of an object being subjected to a tensile and compressive force during the conveying process of the object, and providing capability of the processed surface not contact with rollers and aligning the conveying path. 
         [0011]    The disclosure provides a conveyor apparatus suitable for conveying an object along a conveying path. The conveyor apparatus includes a control module, an unwinding module, at least one tension sensing module and a rewinding module. The unwinding module includes a first actuating unit, wherein the first actuating unit is electrically connected to the control module. The object is adapted to be wound around the unwinding module and unwound via the first actuating unit. The at least one tension sensing module is disposed on the conveying path, and each of the tension sensing modules includes a set of rollers and a load cell. The load cell is disposed at the set of rollers and electrically connected to the control module, and the object is conveyed along the set of rollers and forms a wrap angle smaller than 180 degrees. The rewinding module includes a second actuating unit, wherein the second actuating unit is electrically connected to the control module. The object is adapted to be wound into the rewinding module via the second actuating unit. 
         [0012]    In the conveyor apparatus of the disclosure, the conveying tension of the object between the rewinding module and the unwinding module is determined by the rotational speed or torque of the first actuating unit and the second actuating unit controlled by the control module. Via the set of rollers an included angle is formed and called the warp angle. The load cell can detect the magnitude of the tension of the object under the wrap angle and feed back to the control module, so that the tension of the object can be controlled to be in a certain range by the control module, so that the object is stably conveyed. In the conveyor apparatus of the disclosure, through the misalignment guiding module sensing the offset status of the object and driving the unwinding module or the rewinding module to move to a reverse direction of the offset direction, the misalignment of the object can be reduced. The object is contact with the first set of rollers and the second set of rollers by a specific wrap angle, so as to reduce the possibility of breakage occurrence of the object when the object is alternately subjected to a tensile and compressive force during the conveying process, and thus the processed surface does not contact with the rollers to prevent the process failure. 
         [0013]    In order to make the aforementioned and other features of the disclosure more comprehensible, embodiments accompanying figures are described in detail below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The accompanying drawings constituting a part of this specification are incorporated herein to provide a further understanding of the disclosure. Here, the drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. 
           [0015]      FIG. 1  schematically shows a perspective view of a conveyor apparatus according to an exemplary embodiment of the disclosure. 
           [0016]      FIG. 2  is a schematic side view of the conveyor apparatus of  FIG. 1 . 
           [0017]      FIG. 3  is a schematic view of the unwinding module of the conveyor apparatus of  FIG. 1 . 
           [0018]      FIG. 4  is a schematic view of the first roller and the rotary encoder of the conveyor apparatus of  FIG. 1 . 
           [0019]      FIG. 5  is a schematic view of the second roller and the meter wheel of the conveyor apparatus of  FIG. 1 . 
           [0020]      FIG. 6A  illustrates the testing result of the thin glass which is measured by the first load cell of the conveyor apparatus of  FIG. 1 . 
           [0021]      FIG. 6B  illustrates the testing result of the thin glass which is measured by the second load cell of the conveyor apparatus of  FIG. 1 . 
           [0022]      FIG. 7A  illustrates the testing result of the first position sensing unit of the conveyor apparatus of  FIG. 1 . 
           [0023]      FIG. 7B  illustrates the testing result of the second position sensing unit of the conveyor apparatus of  FIG. 1 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0024]      FIG. 1  schematically shows a perspective view of a conveyor apparatus according to an exemplary embodiment of the disclosure.  FIG. 2  is a schematic side view of the conveyor apparatus of  FIG. 1 . Referring to  FIG. 1  and  FIG. 2 , a conveyor apparatus  100  of the embodiment is suitable for conveying a thin glass  10 . In the embodiment, the thin glass  10  can be a flexible substrate, wherein the material of the flexible substrate can be glass, polymer, metal or the like, and the disclosure is not limited thereto. In the embodiment, the thin glass  10  has a thickness not greater than 150 μm, particularly under 100 μm; a width not smaller than 100 mm, particularly above 200 mm; a length not smaller than 1 m, particularly above 10 m, but the dimension of the thin glass  10  is not limited thereto. 
         [0025]    The conveyor apparatus  100  of the embodiment includes a control module  110 , an unwinding mechanism  112  and a rewinding mechanism  114 . The unwinding mechanism  112  includes a first unwinding module  120 , a first tension sensing module  130  and a first misalignment guiding module  140 . The rewinding mechanism  114  includes a rewinding module  150 , a second tension sensing module  160  and a second misalignment guiding module  170 . 
         [0026]    The unwinding module  120  includes a first actuating unit  122 , wherein the first actuating unit  122  is electrically connected to the control module  110 . The first actuating unit  122  can be a servo motor, an inverter motor, a regulating speed motor or any other power system as long as speed and torque can be adjusted. The thin glass  10  wound as a glass spool is held by the unwinding module  120  and unwound via the first actuating unit  122 . 
         [0027]    The first tension sensing module  130  includes a first set of rollers and a first load cell  134 . According to the embodiment, the first set of rollers includes at least three first rollers  132 . In the embodiment, the three first rollers  132  are positioned so that a first wrap angle smaller than 180 degrees is formed when the thin glass  10  passes through the first rollers  132 . The first load cell  134  is disposed at two ends of the first roller  132  located in the middle. The first load cell  134  can be connected outside or hidden in the two ends of the rollers and electrically connected to the control module  110 . The first load cell  134  calculates the conveying tension of the thin glass  10  via the magnitude of subjected pressure. The first load cell  134  can transmit the measured tension value to the control module  110 . Then the control module  110  may compare the difference between the measured tension and the target tension, and send signals so as to adjust the rotational speed or torque of the first actuating unit  122 . In an exemplary embodiment, the range of the first wrap angle is between 90 degrees and 160 degrees, and preferably, the first wrap angle is 129 degrees. 
         [0028]    The first misalignment guiding module  140  includes a first position sensing unit  142  and a third actuating unit  144  electrically connected to the control module  110 . The first position sensing unit  142  is used for detecting the offset status of the thin glass  10 . The first position sensing unit  142  may be a linear type sensor, an ultrasonic sensor, an optical sensor, an active charge-coupled device (CCD) or a compressed air flow rate detecting sensor. However, the type of the first position sensing unit  142  is not limited thereto. The third actuating unit  144  is used for driving the unwinding module  120  to move along an axis A perpendicular to the conveying direction of the thin glass  10 . The third actuating unit  144  can be a power system capable of forward and reverse motion such as a servo motor, a reversible motor, a rotary cylinder, a linear motor, an air cylinder or a hydraulic cylinder. 
         [0029]    The rewinding module  150  includes a second actuating unit  152 , wherein the second actuating unit  152  is electrically connected to the control module  110 . The second actuating unit  152  can be a servo motor, an inverter motor, a regulating speed motor or any other power system as long as speed and torque can be adjusted. After the thin glass  10  unwound from the unwinding module  120  passes through the first rollers  132 , the thin glass  10  can pass through a processing area B for printing process, laser process or lamination process, then the thin glass  10  is wound into the rewinding module  150  via the second actuating unit  152 . 
         [0030]    The second tension sensing module  160  includes a second set of rollers and a second load cell  164 . In the embodiment, the second set of rollers includes at least three second rollers  162 , and the three second rollers  162  are positioned so that a second wrap angle smaller than 180 degrees is formed when the thin glass  10  passes through the second rollers  162 . The second load cell  164  is disposed at two ends of the second roller  162  located in the middle. The second load cell  164  can be connected outside or hidden in the two ends of the rollers and electrically connected to the control module  110 . The second load cell  164  calculates the conveying tension of the thin glass  10  via the magnitude of subjected pressure. The second load cell  164  can transmit the measured tension value to the control module  110 . Then the control module  110  may compare the difference between the measured tension and the target tension, and send signals so as to adjust the rotational speed or torque of the second actuating unit  152 . In an exemplary embodiment, the range of the second wrap angle is between 90 degrees and 160 degrees, and preferably, the second wrap angle is 128 degrees. In addition, it has to be mentioned that, the first wrap angle and the second wrap angle mentioned in the embodiment are not the same, but both are still between 90 degrees and 160 degrees. In another embodiment which is not shown with figures, through the control of the position of the rollers, the first wrap angle formed when the thin glass passes through the first rollers and the second wrap angle formed when the thin glass passes through the second rollers can be formed equal to each other. 
         [0031]    The second misalignment guiding module  170  includes a second position sensing unit  172  and a fourth actuating unit  174  electrically connected to the control module  110 . The second position sensing unit  172  is used for detecting the offset status of the thin glass  10 . The second position sensing unit  172  may be a linear type sensor, an ultrasonic sensor, an optical sensor, an active charge-coupled device (CCD) or a pressure flow sensor. However, the type of the second position sensing unit  172  is not limited thereto. The fourth actuating unit  174  is used for driving the rewinding module  150  to move along the axis A. The fourth actuating unit  174  can be a power system capable of forward and reverse motion such as a servo motor, a reversible motor, a rotary cylinder, a linear motor, an air cylinder or a hydraulic cylinder. 
         [0032]    The thin glass  10  in the roll-to-roll processing apparatus is affected by the factors such as the parallelism between the first rollers  132  and the second rollers  162 , uniformity of the tension or deformation of the thin glass  10 , so that the thin glass  10  is easy to offset laterally or vacillate during conveyance. Therefore, it is necessary to appropriately correct the position of the thin glass  10  through the first misalignment guiding module  140  and the second misalignment guiding module  170 , nearby the unwinding module  120 , the processing area B and the rewinding module  150 , in order that the thin glass  10  can be conveyed stably according to a specific reference conveying path, so as to ensure the position accuracy of the product in the processing area B and to improve the rewinding quality of the thin glass  10 . The function of the first position sensing unit  142  and the second position sensing unit  172  is to determine whether the edge of the thin glass  10  is beyond the preset range. A direct driving method can be used for correcting the unwinding module  120  and the rewinding module  150  to drive the unwinding module  120  and the rewinding module  150  to perform offsetting laterally, so that the misalignment of conveying direction of the thin glass  10  can be corrected. 
         [0033]    In addition, in order to avoid the breakage of the thin glass  10  due to the alternating tensile and compressive stress applying on the thin glass  10  because the upper and lower surfaces of the thin glass  10  are repeatedly contact with the first rollers  132  and the second rollers  162 , and in order to avoid the processed surface being contact with the rollers during the specific fabricating process (e.g., coating process), in the embodiment, alternately conveying method is avoided in the conveying path of the thin glass  10 . In other words, the thin glass  10  is conveyed in a manner that merely one surface  12  (the lower surface as shown in  FIG. 2 ) of the thin glass  10  is contact with the first rollers  132  and the second rollers  162 , so as to reduce the possibility of breakage due to the alternating tensile and compressive stress subjected to the thin glass  10  or to avoid the chance of the processed surface caused damage. 
         [0034]    Giving consideration to during the conveyance, when the thin glass  10  passed through the first rollers  132  and the second rollers  162 , small dimension of the first rollers  132  and the second rollers  162  may cause the thin glass  10  to have a larger bending stress and so that the difference between the tensile stress and the compressive stress subjected to the upper and lower surfaces of the thin glass  10  may be increased and the thin glass  10  may be broken. In order to reduce the above mentioned circumstances, in the embodiment, the diameter of each of the first rollers  132  and the second rollers  162  is greater than 3 inches, so as to reduce the bending stress of the thin glass  10 . 
         [0035]    During the conveyance of the thin glass  10 , if foreign materials enter between the thin glass  10  and the first rollers  132  or the second rollers  162 , or if there is a slip between the thin glass  10  and the first rollers  132  or the second rollers  162 , the surface of the thin glass  10  may get scrapes. For the application field of the flexible electronic products, the thin glass  10  is required to be performed by processes such as electronic screen printing, laminating, exposure, developing, etching and the like according to different products. Thus, the scrapes may cause defects like the electric circuit damage and the display transparency decrease. 
         [0036]    In order to avoid above mentioned circumstances, in the embodiment, the conveyor apparatus  100  further includes an air floating stage  180  disposed in the processing area B which is located between the first rollers  132  and the second rollers  162 . The air floating stage  180  is used for spouting out airflow, so as to avoid the scraping between the thin glass  10  and the mechanisms or components of the processing area B. The air floating stage  180  includes a porous surface  180   a , wherein the material of the porous surface  180   a  may be ceramic, metal, high polymer or fiber. Porous surface may be achieved by using the powder metallurgy or drilling holes on metal plates. In the embodiment, the conveyor apparatus  100  can reduce the conveying dragging force of the thin glass  10  and the possibility of surface scraping through the air floating stage  180 . In addition, the width of the air floating stage  180  may correspond to the width of the thin glass  10 , so as to provide the thin glass  10  a better floating effect. 
         [0037]    Additionally, the thin glass  10  is wound to the unwinding module  120  and the rewinding module  150  in layered structure, in order to reduce scrapes caused to each layer due to direct contact. The conveyor apparatus  100  of the embodiment further includes a medium layer unwinding module  182 , a medium layer rewinding module  184  and a medium layer  186 . The medium layer  186  can be plastic, and each layer of the thin glass  10  can be protected by attaching the medium layer  186  to the thin glass  10  so as to reduce the possibility of scrapes between the layers of thin glass  10 . 
         [0038]    The medium layer unwinding module  182  includes a fifth actuating unit  182   a , wherein the fifth actuating unit  182   a  is electrically connected to the control module  110 . The fifth actuating unit  182   a  includes a servo motor, an inverter motor, a regulating speed motor or any other power system as long as speed can be adjusted. As shown in  FIG. 2 , the medium layer unwinding module  182  is disposed at a side of the rewinding module  150 , wherein the wound medium layer  186  is set up around the medium layer unwinding module  182 , the first actuating unit  182   a  drives the medium layer  186  to be unwound from the medium layer unwinding module  182 , and the medium layer  186  is wound into the rewinding module  150  together with the thin glass  10 . 
         [0039]    Similarly, the medium layer  186  is wound between each layer of the thin glass  10  of the unwinding module  120 , if the layers of the thin glass  10  are separated by the medium layer  186  to reduce scraping, when the thin glass  10  is unwound, the medium layer  186  may be unwound simultaneously. The medium layer  186  is wound by using the medium layer rewinding module  184 . The medium layer rewinding module  184  is disposed at a side of the unwinding module  120 , wherein the medium layer rewinding module  184  includes a sixth actuating unit  184   a , and the sixth actuating unit  184   a  is electrically connected to the control module  110 . The sixth actuating unit  184   a  can be a servo motor, an inverter motor, a regulating speed motor or any other power system as long as speed can be adjusted. After the medium layer  186  is unwound from the unwinding module  120  together with the thin glass  10 , the medium layer  186  is wound into the medium layer rewinding module  184  by the driving of the sixth actuating unit  184   a.    
         [0040]    In order to maintain the tension of the medium layer  186  during conveyance, in the embodiment, the medium layer unwinding module  182  further includes at least three third rollers  182   b  and a third load cell  182   c , the third load cell  182   c  is disposed on one third roller  182   b  located at middle of the at least three third rollers  182   b  and electrically connected to the control module  110 . In addition, the medium layer rewinding module  184  further includes at least three fourth rollers  184   b  and a fourth load cell  184   c , the fourth load cell  184   c  is disposed on the third roller  184   b  located at middle and electrically connected to the control module  110 . As such configuration, the medium layer  186  is disposed between each layer of the thin glass  10  to stabilize the conveying tension. In addition, besides the layers of the thin glass  10  being separated by the medium layer  186  during rewinding condition, attaching plastic materials on the edge can also increase the strength and reduce the possibility of breakage during conveyance. 
         [0041]    The conveyor apparatus of the embodiment further includes a first base  190 , a second base  192  and a second moving stage  194 . The unwinding module  120 , the first tension sensing module  130  and the first misalignment guiding module  140  are located on the first base  190 .  FIG. 3  is a schematic view of the unwinding module of the conveyor apparatus of  FIG. 1 . The unwinding module  120  further includes a first moving stage  124 , a first quick release plate  126  and a first air shaft  128 . When the thin glass  10  misaligns while unwinding, the third actuating unit  144  may drive the first moving stage  124  to move along the axis A related to the first base  190 . The first quick release plate  126  is detachably disposed on the first moving stage  124 , wherein an end of the first air shaft  128  is connected to the first actuating unit  122  and the other end of the first air shaft  128  is pivoted to the first quick release plate  126 , and the roll of the thin glass  10  can be wound around the first air shaft  128 . 
         [0042]    As shown in  FIG. 1  and  FIG. 2 , in the embodiment, after leaving the processing area B, the thin glass  10  may pass through the second position sensing unit  172 , and via the second position sensing unit  172  the offset status of the thin glass  10  in the processing area B may be measured and transmitted to the control module  110 . When the control module  110  determines that there is a misalignment status, the control module  110  may send signals so that the fourth actuating unit  174  drives the second moving stage  194  to move along the axis A related to the second base  192  for correcting the misalignment. The proceeding tension measurement and rewinding process are performed after the thin glass  10  is corrected its misalignment. Therefore, in the embodiment, the first moving stage  124  merely carries the unwinding module  120 , and the second moving stage  194  carries the rewinding module  150 , the second tension sensing module  160  and the second misalignment guiding module  170 . 
         [0043]    In order to facilitate taking off the roll of thin glass  10  from the rewinding module  150  after the thin glass  10  is wound by the rewinding module  150 , in the embodiment, the rewinding module  150  further includes a second quick release plate  154  and a second air shaft  156 . The second quick release plate  154  is detachably disposed on the second moving stage  194 , wherein the thin glass  10  is wound around the second air shaft  156 , and an end of the second air shaft  156  is connected to the second actuating unit  152  and the other end of the second air shaft  156  is pivoted to the second quick release plate  154 . 
         [0044]    In the embodiment, the thin glass  10  is unwound from the first air shaft  128  and wound into the second air shaft  156 , and the first quick release plate  126  and the second quick release plate  154  are respectively located at a side of the first air shaft  128  and the second air shaft  156  so as to assist in supporting the edges of the thin glass  10 . Positioning pins  126   a ,  154   a  are used for positioning of the first quick release plate  126  and the first moving stage  124 , and the second quick release plate  154  and the second moving stage  194 , respectively. When the roll of the thin glass  10  is put onto the first air shaft  128  or taken off from the second air shaft  156 , by removing the positioning pins  126   a ,  154   a , the first quick release plate  126  and the second quick release plate  154  can be detached, and in this way the roll of thin glass  10  is easily placed and detached. Furthermore, bearings on the first quick release plate  126  and the second quick release plate  154  are pivoted to the first air shaft  128  and the second air shaft  156 , so as to increase the stability of the roll of the thin glass  10  during rotation. 
         [0045]    The conveyor apparatus  100  further includes a speed measuring module  196  electrically connected to the control module  110 . The speed measuring module  196  is used for measuring a conveying speed of the thin glass  10 . The speed measuring module  196  can be a rotary encoder  196   a  or a meter wheel  196   b .  FIG. 4  is a schematic view of the first roller and the rotary encoder of the conveyor apparatus of  FIG. 1 . Referring to  FIG. 4 , the rotary encoder  196   a  is disposed on an end of the first roller  132  and calculates the conveying speed of the thin glass  10  through the revolution numbers of the rotation of the first roller  132  in a preset time period.  FIG. 5  is a schematic view of the second roller and the meter wheel of the conveyor apparatus of  FIG. 1 . Referring to  FIG. 5 , the meter wheel  196   b  is contact with the second rollers  162  or the thin glass  10 , so as to directly measure the moving distance of the thin glass  10  in a preset time period to obtain the conveying speed of the thin glass  10 . In other embodiments, a yard wheel can also be used instead of the meter wheel  192   b , and the type of speed measuring module  196  is not limited thereto. The speed measuring module  196  transmits the signals to the control module  110  after the conveying speed of the thin glass  10  is measured, and the control module  110  may correct the rotational speed or torque of the first actuating unit  122  and the second actuating unit  152  according to the measurement value. In addition, the control module  110  may also control the first actuating unit  122  and the second actuating unit  152  to continuously convey the glass in a constant speed, or interruptedly convey in a jog movement method. Herein the first rollers  132  may be the second rollers  162 , and the second rollers  162  may also be the first rollers  132 . 
         [0046]    Referring to  FIG. 2 , in the embodiment, the conveyor apparatus  100  further includes an ionizer  198 , wherein the ionizer  198  is disposed at a side of the unwinding module  120 , the first rollers  132 , the second rollers  162  or the rewinding module  150 . The ionizer  198  is used for releasing the residual static electricity of the surface of the thin glass  10  when the thin glass  10  is unwound from the unwinding module  120 , wound into the rewinding module  150 , or conveyed by the first rollers  132  or the second rollers  162  during the conveying process. 
         [0047]    In the embodiment, the control module  110  can control the conveying tension and the conveying speed of the thin glass  10 , correct the offset of the thin glass  10  during conveying, and actuate the relative components of the conveyor apparatus  100 , for example, the air floating stage  180  and the ionizer  198 . However, the components controlled by the control module  110  are not limited thereto. 
         [0048]    In addition, in the embodiment, the tension of the thin glass  10  of the conveyor apparatus  100  can be controlled in the following manner, first, the first load cell  134  or the second load cell  164  reads the tension value of the thin glass  10  on the first rollers  132  or the second rollers  162 , and then the result is sent to the control module  110 . Next, the control module  110  compares the target tension and the measured tension value for calculating the relative tension error value. After that, the control module  110  adjusts the rotational speed or torque of the first actuating unit  122  and the rotational speed or torque of the second actuating unit  152 , so as to perform the tension control.  FIG. 6A  illustrates the testing result of the thin glass which is measured by the first load cell of the conveyor apparatus of  FIG. 1 .  FIG. 6B  illustrates the testing result of the thin glass which is measured by the second load cell of the conveyor apparatus of  FIG. 1 . Referring to  FIG. 6A  and  FIG. 6B , before the unwinding and after the winding, the tension values of the thin glass  10  are substantially very close to the target tension. As such, the conveyor apparatus  100  of the embodiment can stably perform the conveyance of the thin glass  10 . 
         [0049]    Moreover, the position of the thin glass  10  of the conveyor apparatus  100  described in the embodiment can be controlled by the following method. First, the measurement values related to the edge position of the thin glass  10  of the first position sensing unit  142  and the second position sensing unit  172  are read, and the result is sent to the control module  110 . Next, the control module  110  compares the standard position and the measured value for calculating the offset of the edge position of the thin glass  10 . Next, the control module  110  controls the third actuating unit  144  or the fourth actuating unit  174  to correct the unwinding module  120  or the rewinding module  150 .  FIG. 7A  illustrates the testing result of the first position sensing unit of the conveyor apparatus of  FIG. 1 .  FIG. 7B  illustrates the testing result of the second position sensing unit of the conveyor apparatus of  FIG. 1 . The position at 4000 μm of the vertical axis of  FIG. 7A  and  FIG. 7B  represents the standard position of the edge of the thin glass  10 . As shown in  FIG. 7A  and  FIG. 7B , after being unwound and passing through the processing area B, the edge of the thin glass  10  can be maintained at the position very close to the standard position. 
         [0050]    The control module  110  of the conveyor apparatus  100  of the embodiment drives the first actuating unit  122  to drive the first air shaft  128  to rotate, so that the thin glass  10  may pass through the first rollers  132  after the thin glass  10  is unwound from the unwinding module  120 . Then the first load cell  134  detects the tension value of the thin glass  10  and the first position sensing unit  142  detects the edge position of the thin glass  10 , and the first load cell  134  and the first position sensing unit  142  respectively response the results to the control module  110 . The control module  110  can adjust the rotational speed or torque level of the first actuating unit  122  so as to change the tension of the thin glass  10 , and control the third actuating unit  144  so that the first moving stage  124  moves laterally to achieve the effect of adjustment. Then, the thin glass  10  is conveyed to the processing area B for printing process, laser process, lamination process, or the like. After the thin glass  10  leaves the processing area B, the second position sensing unit  172  detects the edge position of the thin glass  10 , so as to ensure the position of the thin glass  10  is correct. If offset occurs, the control module  110  can control the fourth actuating unit  174  to drive the second moving stage  194  laterally to preset position. Next, the thin glass  10  passes through the second rollers  162 . The second load cell  164  detects the tension value of the thin glass  10  before the thin glass  10  is wound and responds the tension value to the control module  110 . The control module  110  adjusts the rotational speed or torque level of the second actuating unit  152  so as to change the tension of the thin glass  10 . Finally, the thin glass  10  is wound into the second air shaft  156  of the rewinding module  150 . 
         [0051]    In light of the foregoing, in the conveyor apparatus of the disclosure, the conveying tension of the thin glass between the rewinding module and the unwinding module is determined by the rotational speed or torque level of the first actuating unit and the second actuating unit controlled by the control module. Via the three first rollers and the three second rollers, constant wrap angles are formed, respectively. The first load cell and the second load cell can detect the tension value of the thin glass under the wrap angles and feed back to the control module, so that the tension of the thin glass can be controlled to be in a certain range by the control module, so that the thin glass is stably conveyed. Furthermore, in the conveyor apparatus of the disclosure, through the first position sensing unit and the second position sensing unit detecting the offset status of the thin glass and the feed back to the control module, the control module controls the third actuating unit or the fourth actuating unit to drive the unwinding module or the rewinding module to move to a reverse direction of the offset direction, and the offset of the thin glass can be reduced. In addition, the thin glass is contact with the first rollers and the second rollers merely by one single surface, so as to reduce the possibility of breakage occurrence of the thin glass when the thin glass is alternately subjected to a tensile and compressive force during the conveying process, so as to avoid the chance of damage of the processed surface. Moreover, through the spouting out airflow to the surface of the thin glass by using the air floating stage, the possibility of scraping between the thin glass and the mechanism or components in the conveying area and the processing area is reduced, and facility of guiding the thin glass is improved. The thin glass of the disclosure can be any other flexible substrate, wherein the material of the flexible substrate can be glass, high polymer, metal or the like, and the disclosure is not limited thereto. 
         [0052]    Although the disclosure has been described with reference to the above embodiments, it is apparent to one of the ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit of the disclosure. Accordingly, the scope of the disclosure will be defined by the attached claims not by the above detailed descriptions.