Patent Publication Number: US-7708176-B2

Title: Web transportation guiding apparatus and method

Description:
BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   The present invention relates to a position guiding technology, and more particularly to a web transportation guiding apparatus and method for guiding a position shift occurred during web transportation. 
   2. Related Art 
     FIG. 1  is a schematic view illustrating that a web has a shift. Since the web  90  has had a lateral shift δ during a winding, which causes a situation that the web  90  snakes when being unwound through a roller  10 . An edge of the web  90  continuously shifts from a position of c towards a position of d during the unwinding, such that a lateral shift on the edge after the web  90  is unwound is exactly δ. The above situation is merely one of the causes for the snaking of the web. Moreover, the inconsistent parallelism between the rollers in a roll to roll equipment is a common reason why the web snakes. Therefore, a good edge tracing guiding module is needed to effectively solve the problem of the snaking of the web. 
   A swing-type edge tracing guiding apparatus available on the market is generally used during the web transportation, however, some problems cannot be directly alleviated in usage. Not because the usage of the swing-type edge tracing guiding apparatus has disadvantages, but the principle of the swing-type edge tracing restricts the overall guiding precision and response speed in some special situations.  FIG. 2  is a schematic view of the swing-type edge tracing guiding apparatus. In the swing-type guiding apparatus in the prior art, the web shift must be compensated by rotating a specific angle for the swing-type edge tracing guiding apparatus. Therefore, when a tiny shift is to be compensated, a driving apparatus must have a higher angle resolution to compensate the tiny shift precisely. 
   In addition, in  FIG. 2 , for a sensor  11 , the web before a critical line A has a tendency of shifting to the right. Therefore, when the web before the critical line A reaches the sensor, an included angle θ 1  must be formed between the swing-type edge tracing guiding apparatus and the critical line A, so as to effectively maintain the edge position of the web at a reference O. However, it should be particularly noted that once the web after the critical line A reaches the sensor, since the web has a tendency of shifting to the left for the sensor, the swing-type edge tracing guiding apparatus must be driven immediately to form an included angle θ 2  with the critical line A, so as to effectively maintain the edge position of the web at the reference O. It should be noted that the swing-type edge tracing guiding apparatus must be rotated by an angle of θ 1 +θ 2  in an extremely short time, but the swing-type edge tracing guiding apparatus is hardly able to respond with a proper angle in time, such that the edge position of the web is deviated from the reference O. 
     FIG. 3  is a schematic view illustrating an error of a swing-type edge tracing guidance in the prior art. An edge position of a web  18  is measured by a sensor  24  that is generally placed between rollers  16  and  22 , and a transportation reference of the web  18  is set at a position at a distance X from a point C. The roller  16  may swing left and right, so as to compensate the shift during the transportation of the web  18 . As shown in  FIG. 3 , when a shift occurs to the web  18  during the transportation, an included angle D is formed between the roller  16  and the roller  22  in order to compensate the shift, and thus a deflection is generated in a region  28  between the rollers  16  and  22 . Although the position of the web  18  detected by the sensor  24  has always been maintained at X, the position of the web  18  after leaving the roller  24  has been changed to Y due to a distance between the sensor  24  and the roller  22 . Therefore, a compensation error δ is generated, and δ=X−Y. 
   In another guiding manner, a translation-type guiding apparatus is used, but a situation in which a moving travel  12  of a linear moving platform reaches a travel limit (as shown in  FIG. 4A ) may occur to the apparatus, such that the function of adjusting a shift of a web  90  is restricted. Moreover, a situation in which the web  90  shifts beyond a clamping range of a roller  13  (as shown in  FIG. 4B ) may occur to the translation-type guiding apparatus. The two situations often occur during the usage of the translation-type guiding apparatus. When encountering the above situations in  FIGS. 4A and 4B , those of ordinary skill in the art often wrongly believe that the problems lie in an insufficient roller length or motor travel, and that the problems can be alleviated as long as the roller length or motor travel is increased. However, this is always not the case. Even if the roller length or motor travel is increased, the time points at which the above situations occur are delayed, but these problems cannot be solved effectively. 
   Furthermore, U.S. Pat. No. 7,267,255 has disclosed a web trace adjustment apparatus in which a driving wheel capable of adjusting a shift is disposed in a gimbal direction, so as to adjust a trace along which a web intends to move. U.S. Pat. No. 6,705,220 has disclosed a web trace adjustment apparatus in which a pair of movable angle bars is used to guide a moving web to enter into or move out of a transportation system. 
   Additionally, U.S. Pat. No. 6,124,201 has also disclosed a web guiding manner, in which a side edge position of a web is monitored, and the position of the web is guided by an upstream guiding apparatus if a shift is found. In addition, U.S. Pat. No. 4,958,111 and U.S. Pat. No. 4,453,659 have also disclosed an apparatus for adjusting a web position. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a web transportation guiding apparatus, which detects a position of a side edge of a web to compensate and adjust the position of the side edge of the web in the web transportation in real time by a mechanism having a coarse adjustment and a fine adjustment if the position of the web is shifted. 
   The present invention is directed to a web transportation guiding method, which not only detects a position of a side edge of a web to compensate and adjust the position of the web in a transportation by a mechanism having a coarse adjustment and a fine adjustment, but also is capable of determining the fine adjustment mechanism about a moving limit, and controlling the coarse adjustment mechanism to change an edge tracing determination position reference thereof if the fine adjustment mechanism satisfies a condition for the moving limit. 
   The present invention is directed to a web transportation guiding apparatus and method that uses a coarse guiding module in combination with a fine guiding module. The fine guiding module is capable of meeting the demand for a high-precision edge tracing, and the coarse guiding module is capable of effectively solving the problem that the translation-type fine guiding module reaches a limit point, thereby realizing the web edge tracing technology with high-precision. 
   In an embodiment, the present invention provides a web transportation guiding apparatus, which includes a coarse position guiding module, a fine position guiding module, and a control module. The coarse position guiding module determines a position of a specific position on a web according to a reference sensor, so as to compensate a shift generated by the web during the web transportation. The fine position guiding module is disposed at one side of the coarse position guiding module, and compensates the shift generated by the web during the transportation according to the position of the specific position on the web. The control module determines whether to send a control signal to the coarse position guiding module according to a position of the fine position guiding module, so as to change the position reference. 
   In another embodiment, the present invention further provides a web transportation guiding method including the following steps. A coarse position guiding module and a fine position guiding module are provided, which are respectively provided for a web to pass through and may adjust a position of the web. The coarse position guiding module determines whether the position of the web is shifted according to a reference. If the fine position guiding module approaches a limit of the moving travel, the coarse position guiding module is notified to change the reference. 

   
     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: 
       FIG. 1  is a schematic view illustrating that a web generates a shift; 
       FIG. 2  is a schematic view of a swing-type edge tracing guiding apparatus; 
       FIG. 3  is a schematic view illustrating an error of a swing-type edge tracing guidance in the prior art; 
       FIGS. 4A and 4B  are schematic views illustrating a moving limit of a linear moving platform; 
       FIG. 5  is a schematic view of a web transportation guiding apparatus according to a first embodiment of the present invention; 
       FIG. 6  is a schematic flow chart of processes of a web transportation guiding method according to the present invention; 
       FIG. 7  is a schematic view illustrating a moving travel of an adjustment mechanism of a fine position guiding module in  FIG. 5 ; 
       FIG. 8  is a schematic view illustrating a parameter changed reference; 
       FIGS. 9A and 9B  are top views illustrating an operation of the web transportation guiding apparatus according to the first embodiment of the present invention; 
       FIGS. 10A and 10B  are schematic enlarged views of a coarse position sensor and a fine position sensor of the web transportation guiding apparatus according to the first embodiment of the present invention; 
       FIG. 11  is a schematic view of a web transportation guiding apparatus according to a second embodiment of the present invention; 
       FIG. 12A  is a schematic view of a web transportation guiding apparatus according to a third embodiment of the present invention; 
       FIG. 12B  is a schematic structural view of a suction roller of the present invention; 
       FIGS. 13A to 13D  are schematic views of a valve of the present invention; 
       FIGS. 14A to 14C  are schematic views illustrating that the suction roller of the present invention transports an object; and 
       FIG. 15  is a schematic view of a web transportation guiding apparatus according to a fourth embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In order to make the features, objectives, and functions of the present invention become more comprehensible, the structures and design ideas and reasons of relevant details of the apparatus in the present invention are illustrated below. The detailed illustration is stated as follows. 
     FIG. 5  is a schematic view of a first embodiment of a web transportation guiding apparatus of the present invention. Referring to  FIG. 5 , in this embodiment, the web transportation guiding apparatus  3  includes a coarse position guiding module  30 , a fine position guiding module  31 , and a control module  32 . The apparatus  3  controls the coarse position guiding module  30  and the fine position guiding module  31  through the control module  32 . A web  90  is transported from the coarse position guiding module  30  towards the fine position guiding module  31 . Positions of specific positions on the web  90  can be individually detected through the coarse position guiding module  30  and the fine position guiding module  31  during the transportation of the web  90 , so as to be used as a basis for determining a compensation of the position of the web  90 , such that the web  90  is transported along preset positions. In this embodiment, the specific positions of the web  90  are, but not limited to, side edges  901  and  902 . 
   The coarse position guiding module  30  having an adjustment precision approximately in a range of hundreds of μm includes a coarse position sensor  300 , a coarse position control unit  301 , and an adjustment mechanism  302 . The coarse position sensor  300  is electrically connected to the coarse position control unit  301 , and the coarse position control unit  301  is electrically connected to the adjustment mechanism  302  and the control module  32 . The coarse position sensor  300  functions to measure a position of the side edge  901  of the web. The position value measured by the coarse position sensor  300  is returned to the coarse position control unit  301  to be analyzed. When determining that a shift occurs to the side edge  901  of the web  90 , the coarse position control unit  301  may control the adjustment mechanism  302  to compensate the shift of the web  90  in real time. The adjustment mechanism  302  may adjust the position of the side edge of the web  90  in a manner of a linear displacement motion or a swing motion. In this embodiment, the adjustment motion is the swing motion. 
   The adjustment mechanism  302  further has a pair of rollers  3020  and a linear moving platform  3021 . The pair of rollers  3020  has a pivot point  3022 . The linear moving platform  3021  is connected to the pair of rollers  3020 . The linear moving platform  3021  swings the pair of rollers  3020  about the pivot point  3022  according to the coarse position control signal, thereby driving the web  90  to swing left and right, so as to achieve the edge tracing guiding effect. In addition, a roller  33  is used to change a traveling height of the web  90 , such that the web  90  can pass by the pair of rollers  3020  during the transportation. The adjustment mechanism  302  belongs to the prior art and will not be repeated herein. Another kind of adjustment mechanism adjusts the position of the web in a manner of translational motion. 
   As shown in  FIG. 5 , the fine position guiding module  31  having a control precision in a range of tens of μm includes an adjustment mechanism  310 , a fine position sensor  311 , and a fine position control unit  312 . A position value measured by the fine position sensor  311  is returned to the fine position control unit  312  to be analyzed. When determining that a shift occurs to the side edge  902  of the web  90 , the fine position control unit  312  may control the adjustment mechanism  310  to compensate the shift of the web  90  in real time. The fine position guiding module  31  may be regarded to have the fine positioning function. The fine position guiding module  31  employs a lateral translation-type edge tracing manner, and the adjustment mechanism  310  thereof may perform the translation-type edge tracing guidance on the web in a clamping, adsorption, or friction manner. In this embodiment, the adjustment mechanism  310  is a translation-type clamping mechanism which may perform a linear displacement movement to adjust the position of the web  90 . In this embodiment, the adjustment mechanism  310  has a pair of rollers  3100  and a linear moving platform  3101 . The pair of rollers  3100  may be provided for clamping the web  90 . The linear moving platform  3101  is coupled to the pair of rollers  3100 , and drives the pair of rollers  3100  to generate a linear displacement motion according to the fine position control signal, thereby adjusting the position of the web. 
   In addition, the adjustment mechanism  310  further has an encoder  3102  electrically connected to the control module  32 . The encoder  3102  may return an absolute position of the linear moving platform  3101  of the adjustment mechanism  310  to the control module  32 , such that the control module  32  gets to know a position status of the adjustment mechanism  310  at any time. The type and principle of the encoder  3102  belong to the prior art and will not be repeated herein. When the control module  32  confirms that the position about the adjustment mechanism  310  returned by the encoder  3102  is about to reach a limit point of a certain edge according to the position, the control module  32  transfers a control instruction to the coarse position control unit  301 , and the coarse position control unit  301  changes an edge tracing reference position of the coarse position guiding module  30  according to the content of the control instruction. In addition, although the above control module  32 , coarse position control unit  301 , and fine position control unit  312  are separated from each other in the implementation, they can be integrated by those skilled in the art to similarly achieve the specific effect of the present invention. The control module  32  may be, but not limited to, various processors such as a computer, a control chip IC, or a programmable logic controller (PLC). 
   Referring to  FIGS. 5 and 6 ,  FIG. 6  is a schematic flow chart of processes of a web transportation guiding method according to the present invention. In this embodiment, the guiding method  4  includes control rules of the coarse position guiding module  30  and the fine position guiding module  31 . A block B is the control rule of the coarse position guiding module  30 , and a block A is the control rule of the fine position guiding module  31 . In Step  40 , the control rules of the coarse position guiding module  30  and the fine position guiding module  31  may be activated simultaneously, or the control rule of the coarse position guiding module  30  or the control rule of the fine position guiding module  31  may be activated alone. In Step  400 , it is first determined whether the fine position guiding module  31  approaches a moving limit of the adjustment structure.  FIG. 7  is a schematic view illustrating a moving travel of the adjustment mechanism of the fine position guiding module  31  in  FIG. 5 . In  FIG. 7 , D represents a linear movement range of the linear moving platform  3101  of the entire adjustment mechanism. In order to prevent the adjustment mechanism from moving to limits, i.e., two ends of D when compensating the web position, the present invention defines a movement interval d as a reference of safe movement, that is, uses regional ranges between boundaries of the movement interval d and boundaries of the linear movement range D as a basis for determining whether the fine position guiding module approaches the limit of the moving travel. The size of the regional ranges between the boundaries of the movement interval d and the boundaries of the linear movement range D may depend on demands and is not limited. Referring to  FIGS. 5 and 6  again, in Step  400 , it is determined whether the adjustment mechanism  310  moves beyond the range of the movement interval d. If a position of the linear moving platform  3101  of the fine position guiding module  31  is still a distance from the limit point, the flow proceeds to Step  401  in which the fine position sensor  311  is used to measure a position of the side edge  902  of the web  90 . In Step  402 , it is determined whether a shift occurs to the web  90 . If a shift occurs, the flow proceeds to Step  403  in which the fine position guiding module  31  is driven to compensate the shift of the web  90 . Then, the flow returns to Step  400  through Step  412 , and is executed repeatedly. 
   After a series of repeated executions of Steps  400 - 403 , if in Step  400  it is first determined that the fine position guiding module  31  has approached the travel limit point, i.e., exceeded the range of the movement interval d U.S. Pat. No. 4,958,111 and U.S. Pat. No. 4,453,659 in  FIG. 7 , the flow proceeds to Step  404  of sending out a signal to change an edge tracing reference of the coarse position guiding module  30 , and to Step  405  of sending out an abnormal warning. The block B is the control rule of the coarse position guiding module, in which a coarse edge tracing work on the web may be performed independently. First, in Step  407 , it is detected whether a trigger signal from Step  404  exists. Once the signal of Step  404  is received in Step  407 , the flow proceeds to Step  411  to change the edge tracing reference of the coarse position guiding module  30 . The edge tracing reference of the coarse position guiding module may be changed by moving the position of the coarse position sensor  300  or by setting a parameter, but not limited thereto.  FIG. 8  is a schematic view illustrating a parameter changed reference. Before the reference is changed by the use of a parameter, it is determined that a reference position  91  of a side edge shift of the web is at a center of the coarse position sensor  300 , i.e., a zero point. However, if the reference for determination is to be changed by the use of the parameter, the change may be made in a software manner to move the position of the zero point to the left or to the right since the position of the coarse position sensor  300  is not changed. In  FIG. 8 , the position of the zero point is moved to the left to the position of a label  92 . That is, if the reference is changed to the position  92 , the side edge of the web  90  is determined as shifted if not at the position of  92 . 
   Referring to  FIGS. 5 and 6  again, the flow immediately proceeds to Step  408  to measure the edge position of the web. Then, in Step  409 , it is determined whether a shift occurs to the web according to a new edge tracing reference changed in Step  411 . Afterwards, the coarse position guiding module  30  is driven to compensate the shift of the web  90  in Step  410 . After that, the flow returns to Step  407  again to perform an edge tracing guidance. The above illustrates the flow of the edge tracing guidance performed in the block B after the signal of Step  404  is received. When the edge tracing reference of the coarse position guiding module needs not to be changed in a normal situation, the flow directly proceeds from Step  407  to Step  408  to measure the side edge position of the web  90 . Afterwards, in Step  409 , it is determined whether a shift occurs to the web  90  according to an edge tracing reference that is set finally. Then, the coarse position guiding module  30  is driven to compensate the shift of the web  90  in Step  410 . In Step  412 , it is determined whether to stop the edge tracing on the web  90 . If the user requires stopping the edge tracing operation on the web  90 , the flow of the web transportation guiding method  4  is ended. The specific efficacy of the present invention for preventing from moving to the limit can be realized by Step  411  in the web transportation guiding method  4 , because the problem that the fine position guiding module reaches the limit point can be solved by changing the edge tracing reference of the coarse position guiding module. In addition, the steps other than Step  411  in the flow of the web transportation guiding method can be deleted or changed randomly in sequence upon demands. 
   Although the pure usage of a translation-type guiding module for performing the edge tracing guidance on the web can obtain a higher edge tracing precision than the usage of a swing-type guiding module alone, after the translation-type guiding module is used alone for a period of time, a limit point of a certain edge may be reached and the edge tracing cannot be continued, and a time point at which the situation occurs cannot be predicted. This is usually associated with an edge roughness when the web is unwound or a parallelism of rollers of the equipment. Especially when the parallelism of the rollers is undesirable, the web always tends to shift in a fixed direction, and the translation-type guiding module soon reaches a limit point of a certain edge under the effect of a recovery of the web in order to compensate the shift of the web. 
     FIGS. 9A and 9B  are top views illustrating an operation of the web transportation guiding apparatus according to the first embodiment of the present invention. Whether the linear moving platform exceeds limit points R (a right limit) and L (a left limit) of the movement interval d can be effectively grasped through the encoder  3102 . Taking  FIG. 9  as an example, since the linear moving platform  3101  is connected to the roller  3100  by a platform  3103 , the platform  3103  is driven by the linear moving platform  3101  to move on a track of the linear moving platform  3101 , thereby driving the roller  3100  to move. When the platform  3103  is moved to reach the travel limit point L of the linear moving platform  3101 , it indicates that the coarse position guiding module  30  always transports the web  90  in a certain direction. Therefore, after the web  90  enters into the fine position guiding module  31 , the fine position guiding module  31  must continuously guide the web  90  in the same direction, such that finally the platform  3103  gradually approaches the travel limit point L. Currently, the common equipment cannot effectively ensure that the web remains perpendicular to the rollers during the actual web transportation. Therefore, when the web  90  enters into the coarse position guiding module  30 , an angle difference θ exists between the web  90  and the roller  33 , and the sensor  300  of the coarse position guiding module  30  may measure a position of the edge of the web  90 . Once a shift generated by the edge of the web  90  is found, the roller  3020  is driven to swing by the linear moving platform  3021  to compensate the shift, such that the edge of the web  90  can be effectively maintained at a position of an edge tracing reference m of the coarse position guiding module  30 . After the web  90  passes through the coarse position guiding module  30 , a coarse positioning of the web  90  can be regarded as completed. The web  90  subsequently enters into the fine position guiding module  31 . The fine position guiding module  31  used in the first embodiment employs the translation-type edge tracing manner. In this manner, the sensor  311  of the fine position guiding module  31  may measure a position of the web edge. Once a shift generated by the web edge is found, the roller  3100  is driven to translate by the linear moving platform  3101  to compensate the shift, such that the web edge can be effectively maintained at a position of an edge tracing reference n of the fine position guiding module  31 . 
   It can be found from  FIG. 9A  that an error ΔX exists between the edge tracing reference n of the fine position guiding module  31  and the edge tracing reference m of the coarse position guiding module  30 , because human errors or errors in mechanism assembly are difficult to avoid when the sensors  300  and  311  are erected. Therefore, no error exists between the edge tracing references n and m cannot be effectively determined, and because of the existence of the error ΔX, the fine position guiding module  31  reaches the limit of a certain edge after operating for a period of time. In  FIG. 9A , for example, an edge of the platform  3103  of the linear moving platform  3101  reaches the left limit L, and the linear moving platform  3101  has an insufficient travel to continue performing the edge tracing guidance to the left. Since the coarse position guiding module  30  controls the web edge at the position of the edge tracing reference m but the fine position guiding module  31  needs to control the web edge at the position of the edge tracing reference n, the linear moving platform  3101  should drive the roller  3100  to translate so as to compensate the shift ΔX, such that the position of the web edge is compensated from m to n. Since the fine position guiding module  31  must compensate the shift ΔX continually, and meanwhile the web  90  is subjected to a recovery force and generates a recovery, finally the edge of the platform  3103  of the linear moving platform  3101  is moved to the left limit L under repeated actions of the compensation of the shift ΔX and the recovery. 
   Therefore, in an algorithm of the present invention, when the linear moving platform  3101  reaches or approaches the left limit L, a signal is sent to the coarse position guiding module  30  to require changing the edge tracing reference m of the coarse position guiding module  30 , such that the linear moving platform  3101  of the fine position guiding module  31  may have sufficient travel to continue compensating the shift. When the edge of the platform  3103  of the linear moving platform  3101  reaches or approaches the position of the left limit L, the algorithm of the present invention sends out the signal to the coarse position guiding module  30  and changes the edge tracing reference m of the coarse position guiding module  30 . The edge tracing reference m of the coarse position guiding module  30  is modified intentionally with the wish that the linear moving platform can be moved in a direction away from the limit point L so as to return to the center of the travel by changing the position where the web  90  enters into the fine position guiding module  31 . In addition, when the platform  3103  of the linear moving platform  3101  reaches or approaches the position of the right limit R, the algorithm similarly sends out a signal to the coarse position guiding module  30  and changes the reference. 
   How the novel solution solves the problem that the translation-type guiding module reaches the limit point by changing the edge tracing reference position of the swing-type guiding module will be illustrated below. As shown in  FIG. 9B , with the procedure in  FIG. 6 , when it is found that the limit L is to be exceeded, a signal is sent out to the coarse position guiding module  30  to require changing the edge tracing reference m of the coarse position guiding module  30 . At this time, the edge tracing reference of the coarse position guiding module  30  is changed from m to m′.  FIG. 10A  is a partial enlarged view of the edge tracing reference of the coarse position guiding module  30 , as shown in the figure, it can be found that the edge tracing reference m′ after the change is spaced at a distance of ΔP from the edge tracing reference m before the change. The distance of ΔP may be achieved by moving the position of the sensor or changing internal settings of the algorithm as described above, and will not be repeated herein.  FIG. 10B  is a partial enlarged view of the edge tracing reference of the fine position guiding module  31 , as shown in the figure, originally an error ΔX exists between the edge tracing reference m of the coarse position guiding module  30  and the edge tracing reference n of the fine position guiding module  31 , the edge tracing reference of the coarse position guiding module  30  is changed from m to m′ because of a variation of the distance ΔP generated by the change of the edge tracing reference, and ΔP≧ΔX. Therefore, a new error ΔD is generated between the edge tracing reference m′ of the coarse position guiding module  30  and the edge tracing reference n of the fine position guiding module  31 . Because of the new error ΔD between the edge tracing references of the coarse position guiding module  30  and the fine position guiding module  31 , the problem that the edge of the platform  3103  of the linear moving platform  3101  shifts towards the left limit L can be solved exactly through the error ΔD. Since the fine position guiding module  31  finds that the coarse position guiding module  30  controls the web edge at the position of the edge tracing reference m′ but the fine position guiding module  31  needs to control the web edge at the position of the edge tracing reference n, the linear moving platform  3101  should drive the roller  3100  to translate so as to compensate the shift ΔD, such that the position of the web edge is compensated from m′ to n. Since the fine position guiding module  31  must compensate the shift ΔD continually, and meanwhile the web  90  is subjected to a recovery force and generates a recovery, finally the edge of the platform  3103  of the linear moving platform  3101  is away from the left limit L under repeated actions of the compensation of the shift ΔD and the recovery, and the problem that the translation-type guiding module reaches the limit point is effectively solved. 
     FIG. 11  is a schematic view of the web transportation guiding apparatus according to a second embodiment of the present invention. This embodiment is basically the same as the embodiment in  FIG. 5 . The difference lies in that the roller  3100  in the upper side of the adjustment structure  310  of the fine position guiding module  31  has a recess  3104 . Since a circuit or pattern may be formed on the web surface due to a process, and the upper roller tends to crush the process pattern or circuit on the web surface in the manner of  FIG. 5 , a replacement with the roller  3100  having the recess  3104  may avoid the damage to the web surface. The implementation and control method of the embodiment in  FIG. 11  is as described above and will not be repeated herein. 
     FIG. 12A  is a schematic view of the web transportation guiding apparatus according to a third embodiment of the present invention. This embodiment is basically the same as that in  FIG. 5 . The difference lies in that the fine position guiding module uses a suction roller  313  to replace the roller set clamping the web  90  with a vacuum adsorption manner, and controls the position of the web  90  by adjusting a left and right position of the suction roller  313 . This is because the left and right deviation position of the web  90  can be adjusted upon an adsorption of the web  90  by the suction roller  313 , and the web  90  keeps its position never changed under a suction force.  FIG. 12B  is a schematic structural view of the suction roller according to the present invention. In this embodiment, the suction roller  313  has an outer sleeve  3130 , an outer roller  3131 , and an inner roller  3132 . The outer sleeve  3130  has a plurality of first through holes  3133 . A material of the outer sleeve  3130  is one selected from among steel, glass, ceramic, fiber, and plastic materials. The outer roller  3131  is accommodated in the outer sleeve  3130  and has a plurality of second through holes  3135  corresponding to the plurality of first through holes  3133 . Each of the second through holes  3135  is provided for accommodating a valve  3136 . In this embodiment, the second through hole  3135  is a conical hole. In order to prevent the valve  3136  from dropping off the first through hole  3133  when the outer roller  3131  is rotated to a specific position, an aperture of the first through hole  3133  is smaller than the outermost aperture of the second through hole  3135 .  FIGS. 13A to 13D  are schematic views of the valve according to the present invention. In order to match with the second through hole  3135 , the valve  3136  may be a sphere shown in  FIG. 13A  or a cone shown in  FIG. 13B . Furthermore, the valve  3136  may also be long strip shaped, for example, a circular cylinder in  FIG. 13C  or a cone cylinder in  FIG. 13D . It is understood that if the valve  3136  is cylindrical shaped, the second through hole  3135  is also an elongated hole matching therewith. A material of the valve  3136  is one selected from among steel, glass, ceramic, fiber, and plastic materials. The suction roller  313  may be connected to a negative pressure source  3138  through pipe lines  3137  at one side thereof. The negative pressure source  3138  provides a negative pressure, such that the suction roller  313  generates a suction force to adsorb the web  90 . 
     FIGS. 14A to 14C  are schematic views illustrating that the suction roller of the present invention transports an object. In  FIG. 14A , the web  90  is adsorbed upon contacting the surface of the outer sleeve  3130 . Because the valve  3136  contacting a convex portion  3134  of the inner roller  3132  is pressed open by the inner roller  3132  so as not to completely close the second through hole  3135 , the negative pressure may adsorb the web  90  through the first through hole  3133 . As shown in  FIG. 14B , when the outer sleeve  3130  is rotated, the valve  3136  is rotated accordingly. During the rotation of the outer sleeve  3130 , the valve  3136  is pressed against the convex portion  3134  on the inner roller  3132  in turn with the rotation, so as to form a vacuum air flow gap instead of originally plugging the second through hole  3135  of the outer roller  3131  to generate a vacuum adsorption to directly adsorb the web  90  and transport the web  90 . When a position of the suction roller  313  is adjusted left and right, the web  90  is pulled to move left and right and keeps its position never changed under a suction force. As shown in  FIG. 14C , after departing from the convex portion  3134 , the rotated valve  3136  is sucked again by the negative pressure passing through the second through hole  3135  to plug the second through hole  3135 , so as to close the vacuum air flow gap. At this time, the web  90  is released without the vacuum air flow adsorption. Through the rotation of the suction roller  313 , the valves  3136  above the convex portion  3134  tightly adsorb the web  90  by the vacuum air, and the valves  3136  in regions (the regions that the convex portion  3134  is not pressed against) where the web  90  is not adsorbed plug the second through holes  3135  of the outer roller  3131 , so as to transport the web  90  forward gradually. 
     FIG. 15  is a schematic view of the web transportation guiding apparatus according to a fourth embodiment of the present invention. In this embodiment, the web transportation guiding apparatus  5  includes a coarse position guiding module  50  and a fine position guiding module  51 . The fine position guiding module  51  employs a lateral translation-type edge tracing manner to perform a translation-type edge tracing guidance on the web  90  in a friction manner. The fine position guiding module  51  has a fine position sensor  510 , a fine position control module  511 , and an adjustment mechanism  512 . Functions and structures of the fine position sensor  510  and the fine position control module  511  are the same as those described above and will not be repeated herein. The adjustment mechanism  512  has a friction roller  5120  having a rough surface structure  5121  through which the friction roller  5120  have friction with the web  90 . A position of a side edge of the web  90  is measured by the fine position sensor  510 . Once a shift generated by the side edge of the web  90  is found, a linear moving platform  5122  connected to the friction roller  5120  moves the friction roller  5120 . At this time, the friction roller  5120  may have friction with the web  90  and drive the web  90  to move, so as to guide the shift of the web. A structure of the linear moving platform  5122  is as described above and will not be repeated herein. 
   Furthermore, in this embodiment, the coarse position guiding module  50  is a lateral translation-type edge tracing guiding apparatus and has a rotatable roller  500 . Since it is rotatable, the roller  500  can be used to carry a web roll  501  to unwind the web. In addition, the roller  500  may also wind up the web at the end of the process to form the web roll  501  in  FIG. 15 . The roller  500  and a linear moving platform  502  of the coarse position guiding apparatus  50  are connected to each other via a block vertical plate  503 . The detailed connection manner belongs to the prior art and will not be repeated herein. A shift of the side edge of the web  90  is measured by a coarse sensor  504 . The linear moving platform  502  is operated in a lateral translation manner, and thus drives the web  90  to translate left and right so as to achieve the edge tracing guiding effect. The interaction between the coarse position guiding apparatus  50  and the fine position guiding apparatus  51  may be as described according to the flow in  FIG. 6  and will not be repeated herein. 
   The above descriptions are merely preferred embodiments of the present invention, but not intend to limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents. 
   To sum up, the web transportation guiding apparatus and method provided in the present invention uses the coarse guiding module in combination with the fine guiding module. The fine guiding module is capable of meeting the demand for a high-precision edge tracing, and the coarse guiding module is capable of effectively solving the problem that the translation-type fine guiding module reaches a limit point, thereby realizing the web edge tracing technology with high-precision. Therefore, the present application has been able to raise the industrial competitiveness and spur the development of peripheral industries and met the requirements for an invention application according to the provisions of the Invention Patent Law. Thus, we file the present application for a patent according to the law and would be appreciated if the Examiner examines it and grants it a patent.