Abstract:
Transport of strip-shaped workpieces, including those that have through openings, is control based on the output of upper and lower sensors provided between the delivery reel and processing part for detecting sagging of the workpiece at two points. The strip-shaped workpiece is subjected to processing and transport with a preset frequency, and upon occurrence of a state in which the upper sensor has determined the absence of sagging of the workpiece on the delivery side of the processing part and the lower sensor of this side has determined the presence of the workpiece, a fault is recognized, and processing and transport are interrupted if this detected state does not change during an interval that is a multiple of the preset frequency.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a device for processing of a strip-shaped workpiece, which device transports and processes a strip-shaped workpiece. The invention relates especially to a device for processing of a strip-shaped workpiece in which the operation of a delivery reel and/or a take-up reel can be carried out without problems even in the case in which the strip-shaped workpiece has through openings when a mask pattern is exposed onto the strip-shaped workpiece. 
     2. Description of the Related Art 
     In a device which transports and processes a strip-shaped workpiece (hereinafter also called a “workpiece”) generally a method is used in which a strip-shaped workpiece is pulled off a delivery reel which supplies it, positioned in a processing part of the device at the desired position, and is wound onto a take-up reel. Hereinafter, a continuous workpiece with a great length, such as a rolled film of organic compound, foil metal or the like, is called a “strip-shaped workpiece”. 
     In one such processing device, there are cases in which, between the delivery reel and the processing part, and between the processing part and the take-up reel, there is a dip of the workpiece in which part of the strip-shaped workpiece sags, i.e., the length of the workpiece between the delivery reel and first guide roller is longer than the distance between them so that the workpiece sags between them. The reason for producing this sag is to keep the tension which is exerted on the strip-shaped workpiece constant, and to adjust for the changes in diameter of the workpiece being unwound off of the delivery reel and wound onto the take-up reel, and to transport the workpiece in the processing part with high stop positioning accuracy. In this way, the transport of the strip-shaped workpiece and operation of the delivery reel and the take-up reel can be carried out independently of one another. 
     The strip-shaped workpiece is transported by a transport roller located downstream of the processing part in terms of transport together with a pressure roller clamping and turning the workpiece. The delivery reel and the take-up reel are operated such that the length of the strip-shaped workpiece is determined in the dips by sensors and based on these determination signals the rotation and stopping of the reels are controlled. Japanese patent disclosure document HEI 2-100036 describes a device for exposing a strip-shaped workpiece which is provided with the above described dips. 
     FIG. 6 shows the arrangement of a transport system for a strip-shaped workpiece which is provided with the above described dips. In the figure, a delivery reel  1  is wound with a strip-shaped workpiece W. The strip-shaped workpiece W is delivered by the delivery reel  1  which is driven by a drive device  25 , sent via a first dip A and the guide roller  3  to a processing part  10  and subjected to processing. 
     Transporting of the strip-shaped workpiece W is carried out by a pressure roller  5  and a transport roller  6  which are each located upstream and downstream of the transport direction of a carrier  15  of the processing part  10 . The strip-shaped workpiece W is sent by a drive control of the transport roller  6  onto the carrier  15  of the exposure part  10  which is downstream in the transport direction at a set position. 
     In the processing part  10 , there are, for example, a lamp  11  which emits light which contains UV light, a reflector  12 , a condenser lens  13 , a mask M with a mask pattern, a projection lens  14  and the like. The light which contains UV light and which is emitted by the lamp  11  is reflected by the reflector  12  and is emitted via the condenser lens  13 , the mask M and the projection lens  14  onto the strip-shaped workpiece on the carrier  15 . Thus the mask pattern of the mask M is exposed on the strip-shaped workpiece W. The above described processing part is hereinafter also called the “exposure part”. After completion of exposure, the strip-shaped workpiece W is wound via a guide roller  4  and a second dip B onto a take-up reel  2  which is driven by a drive device  26 . 
     Determination of the strip-shaped workpiece Win dips A and B and operation on the delivery side and the take-up side as shown in FIG. 6 are shown and is described briefly below. 
     The strip-shaped workpiece W is determined using pairs of sensors of the transmission type  21 ,  22 ;  23 ,  24  which are located one above the other, i.e. at two vertically spaced points of each of the dips A and B. 
     In the above described sensors of the transmission type  21 ,  22 ;  23 ,  24 , the emission elements  21   a ,  22   a ,  23   a ,  24   a  belong to one group and the light receiving elements  21   b ,  22   b ,  23   b , and  24   b  belong to one group. When the sensor light emitted by the emission elements  21   a ,  22   a ,  23   a ,  24   a  is shielded by the strip-shaped workpiece Wand is not received by the light receiving elements  21   b ,  22   b ,  23   b ,  24   b , it is determined that the strip-shaped workpiece W is located between the two elements. Hereinafter, the sensors  21 ,  23  are called the “upper sensors” and the sensors  22 ,  24  are called the “lower” sensors. Furthermore, the state in which the light receiving elements  21   b ,  22   b ,  23   b ,  24   b  of sensors  21 ,  22 ,  23  and  24  are not shielded by the strip-shaped workpiece W is called “transmission” and the state in which they are shielded by the strip-shaped workpiece W is called “shielding”. 
     (1) Control of the delivery reel 
     Using FIGS.  7 ( a ) to  7 ( f ), control of a conventional delivery reel is described. FIGS.  7 ( a ) to  7 ( f ) show part on the delivery or takeoff side shown in FIG.  6 . The strip-shaped workpiece W is transported by the transport roller  6  shown in FIG. 6 in the direction toward the exposure part  10  which is located on the right side in the figure. 
     (a) As is shown in FIG.  7 ( a ), the delivery reel  1  turns and begins to deliver the strip-shaped workpiece W and the amount of sagging of the strip-shaped workpiece W is small so that both the upper sensor  21  and also the lower sensor  22  of the dip A are in the transmission state. In this state, the strip-shaped workpiece W is allowed to sag in the dip A. 
     (b) The delivery reel  1  turns and the strip-shaped workpiece W shields the upper sensor  21 , as shown in FIG.  7 ( b ), the delivery reel  1  continues to turn. 
     (c) As is shown in FIG.  7 ( c ), the strip-shaped workpiece W shields the upper sensor  21  and the lower sensor  22 . When this state occurs, the delivery reel  1  stops rotation and delivery of the strip-shaped workpiece W. 
     (d) As is shown in FIG.  7 ( d ), the strip-shaped workpiece W continues to be transported so that the lower sensor  22  is shifted into the transmission state, while the upper sensor  21  is still located in the shielding state. The delivery reel  1  continues the state in which its rotation is stopped. 
     (e) As is shown in FIG.  7 ( e ), as the strip-shaped workpiece W continues to be transported, both the upper sensor  21  and also the lower sensor  22  are shifted into the transmission state (in the same state as the state described above in  7 ( a )), the delivery reel  1  again turns and delivery of the strip-shaped workpiece W begins again. 
     (f) The state which is shown in FIG.  7 ( f ), in which transmission takes place to the upper sensor  21  but the lower sensor  22  is shielded is one that cannot properly occur when the strip-shaped workpiece W is being transported normally. Occurrence of this state is presumably produced because the lower sensor  22  is shielded by scrap and foreign bodies (hereinafter called “barrier”). The rotation of the delivery reel  1  and the transport and processing of the strip-shaped workpiece W are therefore stopped and a fault indication is output. 
     The above described control is summarized below using Table 1. 
     
       
         
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
             
             
               
                 Upper 
                 Transmission 
                 Shielding 
                 Shielding 
                 Transmission 
               
               
                 Sensor 21 
               
               
                 Lower 
                 Transmission 
                 Transmission 
                 Shielding 
                 Shielding 
               
               
                 Sensor 22 
               
               
                 Delivery 
                 Rotation 
                 Continuation of 
                 Stopping 
                 Fault 
               
               
                 Reel control 
                   
                 operation 
               
               
                   
               
             
          
         
       
     
     (2) Control of the Take-Up Reel 
     Using FIGS.  8 ( a ) to  8 ( f ), control of a conventional take-up reel is described. FIGS.  8 ( a ) to  8 ( f ) show part of the take-up side shown in FIG.  6 . The strip-shaped workpiece W is transported from the exposure part  10  to the right by the transport roller  6 ; in FIG. 6, the exposure part is located on the left side of the take-up side. 
     (a) As is shown in FIG.  8 ( a ), the upper sensor  23  and the lower sensor  24  are located in the dip B in the transmission state and the take-up reel  2  is stopped. The strip-shaped workpiece W is transported after completion of exposure by the exposure part  10  and delivered to the dip B. 
     (b) When the strip-shaped workpiece is being delivered, the strip-shaped workpiece W shields the upper sensor  23 , as is shown in FIG.  8 ( b ). The take-up reel  1  remains stopped. 
     (c) As is shown in FIG.  8 ( c ), the strip-shaped workpiece W shields the upper sensor  23  and the lower sensor  24 . The take-up reel  2  begins to turn and take up the strip-shaped workpiece W. 
     (d) As is shown in FIG.  8 ( d ), the strip-shaped workpiece W is taken up and the lower sensor  24  is shifted into the transmission state. The upper sensor  23  is in the shielding state. The take-up reel  2  continues to turn. 
     (e) As is shown in FIG.  8 ( e ), the strip-shaped workpiece W continues to be taken up. When both the upper sensor  23  and also the lower sensor  24  are shifted into the transmission state (in the same state as the state described above in (a)), the take-up reel  22  stops turning. 
     (f) Here, it can be imagined that the state which is shown in FIG.  8 ( f ) and in which transmission to the upper sensor  23  takes place and the lower sensor  24  is shielded is caused by shielding of the lower sensor  24  by a barrier. It is assumed that there cannot properly be this state, as described above relative to the delivery side. Rotation of the take-up reel  2  and transport and processing of the strip-shaped workpiece Ware therefore stopped and a fault indication is output. 
     The above described control is summarized below using Table 2. 
     
       
         
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
             
             
               
                 Upper 
                 Transmission 
                 Shielding 
                 Shielding 
                 Transmission 
               
               
                 Sensor 23 
               
               
                 Lower 
                 Transmission 
                 Transmission 
                 Shielding 
                 Shielding 
               
               
                 Sensor 24 
               
               
                 Take-up 
                 Stopping 
                 Continuation of 
                 Rotation 
                 Fault 
               
               
                 Reel 
                   
                 Operation 
               
               
                 Control 
               
               
                   
               
             
          
         
       
     
     Both on the above described delivery side and also on the above described take-up side, the operation of the reels is called “continuation of previous operation” when the upper sensor is in the shielding state and the lower sensor is in the transmission state. When the upper sensor is in the transmission state and the lower sensor is in the shielding state, operation of the reels is called “stopping of operation due to a problem.” 
     As was described above, in the transport system shown in FIG. 6, the transport of the strip-shaped workpiece for processing by the transport roller  6 , delivery of the delivery reel  1  and take-up of the take-up reel  2  are carried out independently of one another. 
     There are cases in which the strip-shaped workpiece W has through openings which are called “device holes.” FIG. 9 shows one example of a strip-shaped workpiece W with device holes. As FIG. 9 shows, in the strip-shaped workpiece W there are device holes Wd and perforation holes Ph which are used, for example, for transport of the strip-shaped workpiece W. In the areas which are provided with device holes Wd, various devices are installed in a later process. Using these through openings, wiring is connected and devices are installed. 
     The device holes Wd are through openings and therefore pass sensor light. In the dips A and B which are shown in FIG. 6, there are therefore cases in which, depending on the length of the sag of the strip-shaped workpiece W and depending on the pitch with which the device holes Wd are provided, the sensor light passes through the through openings, and in which the existence of the strip-shaped workpiece W cannot be determined even if it is present. 
     There are, for example, the following cases: 
     The light from the upper sensors  21 ,  23  passes through the device holes Wd and a transmission state is determined; and 
     The light from the lower sensors  22 ,  24  is shielded by the area outside the device holes Wd and a shielding state is determined. 
     In this case the above described conventional device indicates a fault and stops treatment even if transport could be carried out without problems. 
     The above described defect is eliminated when the sensors  21 ,  24  are positioned at locations which are not provided with device holes Wd, for example, at locations at which the peripheral area of the strip-shaped workpiece W is determined. The shape and the size of the device holes Wd are however different depending on the pattern formed in the strip-shaped workpiece W, such as a circuit pattern or the like, and there are very many patterns thereof. 
     Therefore, according to the pattern the positions of the sensors  21  to  24  must be changed in the dip, by which a working step is required each time. Furthermore, at the positions at which the sensors  21  to  24  are attached, artificial faults often creep in. Therefore, practical execution is difficult. 
     SUMMARY OF THE INVENTION 
     The invention was devised to eliminate the above described defects in the prior art. 
     The object of the invention is achieve in a device for processing a strip-shaped workpiece in which: 
     a strip-shaped workpiece is provided with a dip, which has been formed by sagging of a strip-shaped workpiece, between the delivery reel and the processing part, and between the processing part and take-up reel; 
     the length of the dips is determined; 
     the strip-shaped workpiece is delivered by one reel and taken up by one reel; and 
     a device is provided for driving the delivery reel; 
     an upper sensor and a lower sensor are located on top of one another at two locations of the dips; and 
     moreover, regardless of the above described delivery and the above described take-up, transport and processing of the strip-shaped workpiece are performed so as to enable the transport of the strip-shaped workpiece, its delivery by a reel and its take-up onto a reel to be continued even if the strip-shaped workpiece has partial through openings, such as device holes or the like, and even if sensor light passes through the above described through holes. 
     by the following being done in accordance with the invention: 
     (1) generally, a control element carries out processing and transport of the strip-shaped workpiece with a preset frequency when the upper sensor has determined the absence of the workpiece, and the lower sensor has determined the presence of the workpiece, and which detects a fault and interrupts processing and transport when the workpiece determination state by the above described upper sensor and the above described lower sensor does not change during the interval during which the above described processing and the above described transport are carried out. 
     The delivery reel is controlled as follows by the above described control element. 
     (a) In the case of a strip-shaped workpiece with through openings, there is not always a barrier in the optical path of the lower sensor, as was described above, even if in the dip transmission of the upper sensor and shielding of the lower sensor were determined. In this case, the device is therefore not immediately considered “disrupted,” but is considered “in a fault reservation state”. The strip-shaped workpiece is processed and transported with a preset frequency, for example three times. 
     (b) When, during the above described interval, the determination state of the strip-shaped workpiece by the above described upper sensor and the above described lower sensor does not change, the device is considered “faulty” and operation of the device is stopped. 
     (c) If at any time during the above described interval the states of the upper sensor and of the lower sensor change, at this point the “fault reservation state” is canceled. Only afterwards, based on the determination signals of the sensors is operation of the delivery reel controlled. This means that the length and the position of the strip-shaped workpiece in the dip change during the intervals during which processing and transport are repeated several times, when the strip-shaped workpiece is correctly delivered. Here, the positions of the through openings and of the shielding area of the strip-shaped workpiece change, and a change arises with certainty in the determination state of the strip-shaped workpiece by the sensors. 
     When the determination state of the strip-shaped workpiece changes, it is recognized that the strip-shaped workpiece is being correctly delivered. Thus, the “fault reservation state” is canceled and operation of the delivery reel is controlled based on the determination signals of the sensors, as is normally the case. 
     On the other hand, it can be imagined that, in the vicinity of the sensor located downstream, there is a barrier which shields the sensor light, or that the lower sensor is faulty when in the determination state of the strip-shaped workpiece no change occurs even with several repetitions of processing and transport. In this case, the device is considered “faulty” and stopped. 
     A strip-shaped workpiece with through openings can be easily transported by the above described control. 
     (2) Additionally, in device described above in (1) for processing of a strip-shaped workpiece there is, generally, a control element which starts operation of the take-up reel when both the upper sensor and the lower sensor have determined the presence of the workpiece and which stops operation of the take-up reel when the upper sensor has determined the absence of a workpiece. 
     The take-up reel is controlled as follows specifically by the above described control element. 
     In the case in which transmission of the upper sensor and shielding of the lower sensor have been determined, in a strip-shaped workpiece with through openings there is not always a barrier in the optical path of the lower sensor, as was described above. In this case, the device is therefore not immediately considered “faulty”. In this state, the rotation of the take-up reel is only started when the drive of the take-up reel has been stopped and when both the upper sensor and lower sensor have determined shielding. The rotation of the take-up reel is stopped when the upper sensor has determined transmission. In this case, the length and the position of the strip-shaped workpiece in the dip change when the strip-shaped workpiece is being transported. Thus, a case arises in which both the upper sensor and also the lower sensor determine shielding. When the sensors are shifted into this state, the take-up reel is turned and the strip-shaped workpiece is taken up. 
     As was described above, the transport of the strip-shaped workpiece, its delivery by a reel and its take-up onto a reel can be continued even if the strip-shaped workpiece has partial through openings, such as device holes or the like, through which sensor light passes by the measure as according to the invention that processing and transport of the strip-shaped workpiece are carried out with a preset frequency when the upper sensor has determined the absence of the workpiece and the lower sensor has determined the presence of the workpiece, these sensors being located in the transition on the side of the delivery reel, and furthermore that a fault is recognized and processing and transport are interrupted, when during the interval, during which the above described processing and the above described transport are carried out, the workpiece determination state by the above described upper sensor or the above described lower sensor does not change. 
     In the case in which the sensor located downstream of the dip on the side of the delivery reel due to a barrier or the like is shifted into a shielding state, or in the case in which in this sensor a fault or the like occurs, it is recognized that a fault has occurred and thus operation of the device can be stopped. 
     On the side of the take-up reel, the operation of the take-up reel is started only when both the upper sensor and lower sensor have determined the presence of a workpiece and furthermore, here, operation of the take-up reel is stopped when the upper sensor has determined the absence of the workpiece. In this way, the strip-shaped workpiece can be taken up without stopping operation of the device even in the case in which the sensor located downstream of the dip on the side of the take-up reel due to a barrier or the like is shifted into a shielding state, or that in this sensor a fault or the like occurs. 
     The invention is explained in detail below with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a schematic of the arrangement of one embodiment of the device in accordance with the invention for processing a strip-shaped workpiece; 
     FIGS.  2 ( a ) to  2 ( c ) each show a schematic of a first control of a delivery reel; 
     FIGS.  3 ( d ) to  3 ( g ) each show a schematic of a second control of a delivery reel; 
     FIGS.  4 ( a ) to  4 ( c ) each show a schematic of a first control of a take-up reel; 
     FIGS.  5 ( d ) to  5 ( g ) each show a schematic of a second control of a take-up reel; 
     FIG. 6 shows a schematic of the arrangement of the transport system for a strip-shaped workpiece which has been provided with dip in accordance with the prior art; 
     FIGS.  7 ( a ) to  7 ( f ) each show a schematic of the control of a conventional delivery reel; 
     FIGS.  8 ( a ) to ( f ) each show a schematic of the control of a conventional take-up reel; and 
     FIG. 9 shows a schematic of one example of a known strip-shaped workpiece with through openings which are called device holes. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a schematic of the arrangement of one embodiment of the device in accordance with the invention for processing a strip-shaped workpiece. A case is described below in which a mask pattern is projection-exposed onto the strip-shaped workpiece by projection exposure. However, the processing of the strip-shaped workpiece is not limited to the above described projection exposure, but other processing can be done. 
     In FIG. 1, as was described above, the strip-shaped workpiece W with which the delivery reel  1  is wound is delivered by the delivery reel  1 , which is driven by the device  25 , and is sent via a first dip A and the guide roller  3  to the exposure part  10  and undergoes exposure. 
     A control element  30  comprises a delivery reel control element  30   a  for drive control of the delivery reel  1 , a take-up reel control element  30   b  for control of the take-up reel  2  and a transport roller control element  30   c  for control of the transport roller  6 . The transport roller  6  is controlled in the same way as in the conventional case and is explained in detail, for example, in the above described Japanese patent disclosure document HEI 2-100036. 
     The delivery reel control element  30   a  of the control element  30  subjects the above described device  25  for driving the delivery reel to drive control based upon the outputs of the upper sensor  21  and the lower sensor  22 , these sensors  21 ,  22  being provided in the dip A, and controls the amount of sag of the strip-shaped workpiece Win the dip A. 
     Transporting of the strip-shaped workpiece W is, as was described above, carried out by the pressure roller  5  and the transport roller  6  which are located upstream and downstream of the exposure element  10  relative to transport direction of the carrier  15  of the exposure part (processing part)  10 . The transport roller control element  30   c  of the control element  30  by the device  27  for driving the transport roller subjects the transport roller to drive control, sends the strip-shaped workpiece W onto the carrier  15  of the exposure part  10  and positions it at a predetermined position. 
     The strip-shaped workpiece W which has been positioned on the carrier  15  is exposed in the exposure part  10 . This means that the light which contains UV light and which is emitted by the lamp  11  is reflected by the reflector  12  and is emitted via the condenser lens  13 , the mask M and the projection lens  14  onto the strip-shaped workpiece on the carrier  15 . Thus, the mask pattern of the mask M is exposed on the strip-shaped workpiece W. After completion of exposure the strip-shaped workpiece W is taken up via a guide roller  4  and second dip B onto a take-up reel  2  which is driven by a device  26  for driving the take-up reel. 
     The take-up reel control element  30   b  of the control element  30  by the outputs of the upper sensor  23  and the lower sensor  24  subjects the above described device  26  for driving the take-up reel to drive control, these sensors  23  and  24  being provided in the dip B, and controls the amount of sag of the strip-shaped workpiece Win the dip B. 
     The strip-shaped workpiece W is determined in the dips A and B in the same manner as described above with FIG. 6 using sensors  21 ,  22 ,  23 ,  24  of the transmission type which are located in pairs, with one sensor above the other, i.e. at two points. In the above described sensors  21 ,  22 ,  23 ,  24  of the transmission type, the emission elements  21  a,  22   a ,  23   a ,  24   a  belong to one group and light receiving elements  21   b ,  22   b ,  23   b , and  24   b  belong to another group. The first group emits sensor light which is received by the respective element of the second group which is located opposite the respective element of the first group. Because the sensor light emitted by the emission elements  21   a ,  22   a ,  23   a ,  24   a  is shielded by the strip-shaped workpiece W, it is determined that the strip-shaped workpiece W is present. 
     In this embodiment, the strip-shaped workpiece W, as was shown using FIG. 9, is provided with device holes Wd as through openings. As was described above, there are cases where the sensor light passes through the above described through openings even in the case in which the strip-shaped workpiece W is located at a position at which it shields the upper sensor  21 , or the upper sensor  21  and the lower sensor  22 , and in which the upper sensor  21  or the lower sensor  22  are shifted into the transmission state. 
     In the above described device for processing of a strip-shaped workpiece, the control of the delivery reel  1  by the delivery reel control element  30   a  of the control element  30  and the control of the take-up reel  2  by the take-up reel control element  30   b  of the controllers are described below. 
     A. Control of the Delivery Reel 
     In this embodiment, the delivery reel control element  30   a  of the control element  30  controls the delivery reel  1  in the manner shown below using Table 3 based on the outputs of the upper sensor  21  and the lower sensor  22  of the dip A. 
     
       
         
               
               
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
             
             
               
                 Upper 
                 Transmission 
                 Shielding 
                 Shielding 
                 Transmission 
               
               
                 Sensor 21 
               
               
                 Lower 
                 Transmission 
                 Transmission 
                 Shielding 
                 Shielding 
               
               
                 Sensor 22 
               
               
                 Delivery reel 
                 Rotation 
                 Continuation of 
                 Stopping 
                 Fault 
               
               
                 Control 
                   
                 Operation 
                   
                 reservation; 
               
               
                   
                   
                   
                   
                 continuation 
               
               
                   
                   
                   
                   
                 of operation 
               
               
                   
               
             
          
         
       
     
     This means that, in the case in which the amount of sag of the strip-shaped workpiece Win dip A is small and both the upper sensor  21  and also the lower sensor  22  are in the transmission state, the delivery reel  1  is turned. In this way, if the amount of sag of the strip-shaped workpiece W is increased and both the upper sensor  21  and also the lower sensor  22  are shifted into the shielding state, rotation of the delivery reel  1  is stopped. By stopping the delivery reel  1 , the amount of sag of the strip-shaped workpiece W is reduced. When both the upper sensor  21  and also the lower sensor  22  are shifted again into the transmission state, the delivery reel  1  is turned. In this way, control is exercised such that the lower end of the strip-shaped workpiece W is in the dip A between the upper sensor  21  and the lower sensor  22 . During the above described operation, the sensor light is passed, for example, by the device holes which are through holes provided in the strip-shaped workpiece W. There are the following cases. 
     (1) Transmission state of the upper sensor  21  and transmission state of the lower sensor  22   
     (2) Shielding state of the upper sensor  21  and transmission state of the lower sensor  22   
     (3) Transmission state of the upper sensor  21  and shielding state of the lower sensor  22   
     In the above described case (1), the delivery reel  1  is turned. In the above described case (2), the previous operating state is continued. If, for example, the delivery reel  1  turns, the rotary state is continued. When the delivery reel  1  stops, the stopped state is continued. The above described case (3) is called the “fault reservation state” in this example. The control element  30  recognizes a fault and stops the device only when this state has been continued by the upper sensor  21  and the lower sensor  22  during the interval with a frequency of transport and exposure (for example, three times) which was set beforehand in an adjustment part  30   d  of the control element  30 . 
     The control of the delivery reel  1  by the above described delivery reel control element  30   a  is described below using FIGS.  2 ( a ) to  2 ( c ) and FIGS.  3 ( d ) to  3 ( g ). The transport direction or the like of the strip-shaped workpiece W is identical to the transport direction or the like described above using FIGS.  7 ( a ) to  7 ( f ). 
     (1) As is shown in FIG.  2 ( a ), the delivery reel  1  is turned and the strip-shaped workpiece W is delivered when the amount of sag of the strip-shaped workpiece W is small and when both the upper sensor  21  and also the lower sensor  22  of the dip A are in the transmission state. In this way, the strip-shaped workpiece W begins to sag in dip A. 
     (2) When the delivery reel  1  turns, the tip of the dip of the strip-shaped workpiece W is between the upper sensor  21  and the lower sensor  22 . Here, the sensors can be in the following two states; 
     (i) As is shown in FIG.  2 ( b ), the shielding area of the strip-shaped workpiece W shields the upper sensor  21 . This is the same state as in the conventional example shown in FIG.  7 ( b ). In this case of the shielding state of the upper sensor  21  and the transmission state of the lower sensor  22 , the previous state is continued; this relates to operation of the delivery reel  1 . This means that rotation of the delivery reel  1  continues. 
     (ii) As is shown in FIG.  2 ( c ), the sensor light of the upper sensor  21  passes through the through openings of the strip-shaped workpiece W. In this way, both the upper sensor  21  and also the lower sensor  22  are shifted into the transmission state. This is the same state as the state shown above using FIG.  2 ( a ). As was described above using FIG.  2 ( b ), the delivery reel  1  turns. 
     (3) By continuing the rotation of the delivery reel  1 , delivery of the strip-shaped workpiece W to the dip A advances, by which the tip of the dip is located underneath the lower sensor  21 . The upper sensor  21  and the lower sensor  22  can be in any of the following four states here. 
     (i) As is shown in FIG.  3 ( d ), the shielding area of the strip-shaped workpiece W shields the upper sensor  21  and the lower sensor  22 . In this case, the delivery reel  1  stops rotation and delivery of the strip-shaped workpiece W. 
     (ii) As is shown in FIG.  3 ( e ), the sensor light of the upper sensor  21  passes through the through openings of the strip-shaped workpiece W. The upper sensor  21  is shifted into the transmission state and the lower sensor  22  is shifted into the shielding state. 
     Conventionally, this was considered “faulty”. In this embodiment, the device is not immediately considered “faulty,” but rather is put in “a fault reservation state.” In this case of “transmission of the upper sensor  21 ” and “shielding of the lower sensor  22 ,” the previous state is continued; this relates to operation of the delivery reel  1 . In this state, the control element  30  continues operation of the device for processing of the strip-shaped workpiece. The control element  30  recognizes a fault and stops the device only when the state as shown in FIG.  3 ( e ) is continuously maintained by the upper sensor  21  and the lower sensor  22  during an interval with a frequency of transport and processing (exposure), for example, during triple exposure and triple transport, which was set beforehand in an adjustment part  30   d  of the control element  30 . 
     If, during this interval, the sensor states change from the states shown in FIG.  3 ( e ), the control element  3  at this instant resets “fault reservation” and continues operation according to the sensor states at this instant. 
     When, due to factors such as a barrier, a fault of the lower sensor  22  and the like, the upper sensor  21  is in the transmission state and the lower sensor is in the shielding state, the state does not change even if the strip-shaped workpiece W is being transported. Therefore, as was described above, a fault can be recognized and the device can be stopped. However, if depending on the state of the position of the strip-shaped workpiece W, the upper sensor  21  is randomly in the transmission state and the lower sensor  22  is in the shielding state, the position of the strip-shaped workpiece W changes as a result of the delivery of the strip-shaped workpiece W by the delivery reel  1  or as a result of the transport of the strip-shaped workpiece W to the exposure part  10  during triple transport and triple processing of the strip-shaped workpiece W. Thus, a change into the states as shown in FIGS.  3 ( d ),  3 ( f ) and  3 ( g ) must inevitably occur. In this case, as was described above, “fault reservation” is reset and operation is continued proceeding from one of the states as shown in FIGS.  3 ( d ),  3 ( f ) and  3 ( g ). 
     (iii) As shown in FIG.  3 ( f ), the upper sensor  21  is in the shielding state. The sensor light of the lower sensor  22  passes through the passage area of the strip-shaped workpiece W, and the lower sensor  22  is shifted into the transmission state. 
     This is the same state as in FIG.  2 ( b ). Rotation of the delivery reel  1  is continued. However, the position of the strip-shaped workpiece W is changed by the delivery of the strip-shaped workpiece W and is inevitably shifted into one of the states as shown in FIGS.  3 ( d ),  3 ( e ) and  3 ( g ). When the state as shown in FIG.  3 ( d ) is obtained, the rotation of the delivery reel  1  is stopped. When the state as shown in FIG.  3 ( e ) is obtained, as was described above, the “fault reservation state” is obtained. When there is neither a barrier nor a fault of the sensor or the like, “fault reservation” is reset. Operation is continued according to the sensor states at this time. 
     (iv) As is shown in FIG.  3 ( g ), the sensor light passes through the passage area of the strip-shaped workpiece W both for the upper sensor  21  and also for the lower sensor  22 . Thus, the sensors  21 ,  22  are shifted into the transmission state. 
     This is the same state as shown in FIG.  2 ( c ) or the state shown in FIG.  2 ( a ). The delivery reel continues to turn. The position of the strip-shaped workpiece W is changed by the delivery of the strip-shaped workpiece W, as was described above, and is inevitably shifted into one of the states as shown in FIGS.  3 ( d ),  3 ( e ) and  3 ( f ). When the state as shown in FIG.  3 ( d ) is obtained, the rotation of the delivery reel  1  is stopped. When there is neither a barrier nor a fault or the like, the state proceeding from the state as shown in FIG.  3 ( e ) or FIG.  3 ( f ) is changed. When the state as shown in FIG.  3 ( d ) is obtained, the rotation of the delivery reel  1  is stopped. 
     (4) If proceeding from the state as shown in FIG.  3 ( d ) the strip-shaped workpiece W is transported, soon one of the states according to FIGS.  2 ( b ),  2 ( c ), FIGS.  3 ( e ),  3 ( f ), and  3 ( g ) is obtained. In the case of the state as shown in FIG.  2 ( b ), the previous state is continued. The delivery reel therefore remains stopped and is soon shifted into the state as shown in FIG.  2 ( a ). In this way, the delivery reel  1  begins to turn. In the case of the state as shown in FIG.  2 ( c ), the same state as the state which is shown in FIG.  2 ( a ) is present. The delivery reel  1  therefore turns. In the cases as shown in FIG.  3 ( e ) and FIG.  3 ( g ), the situation proceeds in the above described manner. When the sensor state passes only into the state as shown in FIGS.  3 ( e ),  3 ( f ), or  3 ( g ), it can be imagined that rotation of the delivery reel  1  does not stop and the strip-shaped workpiece W collects more and more in the dip A. In a transport test in practice using several types of strip-shaped workpieces with a different shape of the device holes, there was not, however, any case in which the strip-shaped workpiece W collected in the dip A. 
     B. Control of the Take-Up Reel 
     In this embodiment, the take-up reel control element  30 ( b ) of the control element  30  controls the take-up reel  2  based on the outputs of the upper sensor  23  and the lower sensor  24  of the dip B in the manner shown in the following table. 
     
       
         
               
               
               
               
               
             
           
               
                   
                 TABLE 4 
               
               
                   
                   
               
             
             
               
                   
                 Upper 
                 Transmission 
                 Shielding 
                 Shielding 
               
               
                   
                 Sensor 23 
               
               
                   
                 Lower 
                 Transmission 
                 Transmission 
                 Shielding 
               
               
                   
                 Sensor 24 
                 or Shielding 
               
               
                   
                 Take-up Reel 
                 Stopping 
                 Continuation of 
                 Rotation 
               
               
                   
                 Control 
                   
                 Operation 
               
               
                   
                   
               
             
          
         
       
     
     This means that, in the case in which the amount of sag of the strip-shaped workpiece W is small and both the upper sensor  23  and also the lower sensor  24  are in the transmission state, the take-up reel  2  is stopped. When the strip-shaped workpiece W is being transported, if the amount of sagging of the strip-shaped workpiece W in the dip B becomes large, and also when the upper sensor  23  is shifted into the shielding state, the stopped state of the take-up reel  2  is maintained. When both the upper sensor  21  and also the lower sensor  22  are shifted into the shielding state, the take-up reel  2  is turned and the strip-shaped workpiece W is taken up. This reduces the amount of sagging of the strip-shaped workpiece W. The rotary state of the take-up reel  2  is maintained even if the upper sensor  23  is shifted into the shielding state. When both the upper sensor  23  and also the lower sensor  24  are shifted again into the transmission state, the take-up reel  2  is stopped. In this way, control is exercised such that the lower end of the strip-shaped workpiece W is in the dip B between the upper sensor  23  and the lower sensor  24 . During the above described operation, the sensor light is transmitted, for example, by the device holes which are through holes provided in the strip-shaped workpiece W. There are the following cases. 
     (1) Transmission state of the upper sensor  23  and transmission state of the lower sensor  24   
     (2) Shielding state of the upper sensor  23  and transmission state of the lower sensor  24   
     (3) Transmission state of the upper sensor  23  and shielding state of the lower sensor  24   
     In the above described case (1), the take-up reel  2  is stopped. In the above described case (2), the previous operating state is continued. If, for example, the take-up reel  2  turns, the rotary state is continued. When the take-up reel  2  stops, the stopped state is continued. In the above described case (3), the take-up reel  2  is stopped in this embodiment. In the state described above in (3), it is possible to imagine a case in which the sensor light is transmitted by the through openings which are located in the strip-shaped workpiece W and in which the upper sensor  23  in spite of the shielding state of the lower sensor  24  has been shifted into a transmission state, and a case in which, in the dip B, there is a barrier or that the lower sensor  24  has a fault. In any case, if the take-up reel  2  is controlled in the manner described in FIG. 4, no problem occurs. 
     If specifically the sensor light is transmitted by the through openings located in the strip-shaped workpiece W, and when the upper sensor  23  in spite of the shielding state of the lower sensor  24  has been shifted into the transmission state, the positions of the through openings are moved by the transport of the strip-shaped workpiece W until soon the upper sensor  23  is also shifted into the shielding state. When this state is reached, the take-up reel  2  begins to turn. Therefore, the problem does not arise that in the dip B the strip-shaped workpiece W collects more and more even if the take-up reel  2  is stopped in the state described above in (3). 
     In the state in which, in the dip B, there is a barrier or in which the state described above in (3) is obtained due to a fault of the lower sensor  24 , by transport of the strip-shaped workpiece W during the stoppage of the take-up reel  2  the upper sensor  23  is soon shifted into the shielding state, by which the take-up reel  2  begins to turn. When the take-up reel  2  begins to turn, the upper sensor  23  is shifted into the transmission state and the lower sensor  24  into the shielding state and the take-up reel  2  stops turning. Then, the same processes are repeated and the amount of sagging of the strip-shaped workpiece W in the dip B is essentially constantly controlled. 
     The control of the take-up reel  2  by the above described take-up reel control element  30 ( b ) is described below using FIGS.  4 ( a ) to  4 ( c ) and FIGS.  5 ( d ) to  5 ( g ). The transport direction or the like of the strip-shaped workpiece W is identical to the one in FIGS.  8 ( a ) to  8 ( f ). 
     (1) As shown in FIG.  4 ( a ), the take-up reel  2  stops when the upper sensor  23  and the lower sensor  24  which are present in the dip B are shifted into the transmission state. The transport roller  6  turns and delivers the strip-shaped workpiece W after completion of exposure to dip B. 
     (2) The bottom end of the sagging strip-shaped workpiece W is located between the upper sensor  23  and the lower sensor  24 . Here, the upper sensor  23  and the lower sensor  24  can be located in the following two states. 
     (i) As shown in FIG.  4 ( b ), the strip-shaped workpiece W shields the upper sensor  23 . This is the same state as in the conventional example. In the case of the shielding state of the upper sensor  23  and the transmission state of the lower sensor  24 , the previous state is continued; this relates to operation of the take-up reel  2 . In this case, the take-up reel  2  remains stopped. 
     (ii) As shown in FIG.  4 ( c ), the sensor light of the upper sensor  23  passes through the through openings of the strip-shaped workpiece W. This shifts the upper sensor  23  into the transmission state. This is the same state as the state shown above using FIG.  4 ( a ). The take-up reel remains stopped. 
     (3) The delivery of the strip-shaped workpiece W to the dip B continues, by which the tip of the dip is located underneath the lower sensor  24 . The upper sensor  23  and the lower sensor  24  can be in the following four states here. 
     (i) As shown in FIG.  5 ( d ), the strip-shaped workpiece W shields the upper sensor  23  and the lower sensor  24 . In this case, the take-up reel  2  starts to turn and to take up the strip-shaped workpiece W. This is the same state as in the conventional example. 
     (ii) As shown in FIG.  5 ( e ), the sensor light of the upper sensor  23  passes through the through openings of the strip-shaped workpiece W. The upper sensor  23  is shifted into the transmission state and the lower sensor  24  is shifted into the shielding state. Conventionally, this is immediately considered “faulty.” However, in this embodiment, the rotation of the take-up reel is stopped. The take-up reel remains stopped until the strip-shaped workpiece W is exposed, transported, and shifted into the state as shown in FIG.  5 ( d ). 
     (iii) As shown in FIG.  5 ( f ), the upper sensor  23  is in the shielding state. The sensor light of the lower sensor  24  passes through the through openings of the strip-shaped workpiece W, and the lower sensor  24  is in the transmission state. This is the same state as in FIG.  4 ( b ). The take-up reel  2  remains stopped. The stoppage of the take-up reel  2  is maintained until the strip-shaped workpiece W is exposed, transported and shifted into the state as shown in FIG.  5 ( d ). 
     (iv) As shown in FIG.  5 ( g ), the sensor light passes through the through openings of the strip-shaped workpiece W both for the upper sensor  23  and also the lower sensor  24 . These sensors  23 ,  24  are in the transmission state. This is the same state as the state as shown in FIG.  4 ( c ) or FIG.  4 ( a ). The take-up reel  2  remains stopped. The stoppage of the take-up reel  2  is maintained until the strip-shaped workpiece W is exposed, transported and shifted into the state as shown in FIG.  5 ( d ). 
     (4) If, proceeding from items (i) to (iv), the state as shown in FIG.  5 ( d ) is reached, the take-up reel  2  turns and it begins to take up the strip-shaped workpiece W. In the case in which, by taking up the strip-shaped workpiece W, the states of the upper sensor  23  and the lower sensor  24  have passed into the state as shown in FIG.  4 ( b ) or FIG.  5 ( f ), the previous state is continued; this relates to operation of the take-up reel. The take-up reel therefore continues to turn and takes up the strip-shaped workpiece W. When the strip-shaped workpiece W has been taken up, and when the state as shown in FIG.  4 ( a ) is reached, the take-up reel  2  stops turning. 
     Furthermore, if, proceeding from FIG.  5 ( d ) a transition into one of the states as shown in FIG.  4 ( c ), FIG.  5 ( e ) and FIG.  5 ( g ) has taken place, the take-up reel  2  stops. The take-up reel  2  continues to be stopped as was described above until the state as shown in FIG.  5 ( d ) has been reached. 
     When the states of the upper sensor  23  and the lower sensor  24  pass only into the state as shown in FIGS.  5 ( e ),  5 ( f ) or  5 ( g ), as on the side of the delivery reel, it can be imagined that the take-up reel  2  is not turning and that the strip-shaped workpiece W is collecting more and more in the dip B. However, in a transport test in practice using several types of strip-shaped workpieces with a different shape of the device holes, there was not any case in which the strip-shaped workpiece W collected in the dip B. 
     Action of the Invention 
     As was described above, the following effects can be obtained in accordance with the invention: 
     (1) Even if the strip-shaped workpiece has partial through openings, such as device holes or the like, through which sensor light passes, the transport of the strip-shaped workpiece, its delivery by a reel and its take-up onto a reel can be continued. 
     (2) In the case in which the sensor which is located downstream of the dip on the side of the delivery reel, due to a barrier or the like, is shifted into a shielding state or a fault or the like occurs in this sensor, occurrence of a fault can be recognized and operation of the device can be stopped. Furthermore, in the case in which the sensor which is located downstream of the dip on the side of the take-up reel due to a barrier or the like is shifted into a shielding state, or that a fault or the like occurs in this sensor, the strip-shaped workpiece can be taken up without stopping operation of the device.