Device for further processing after copying

Abstract: A transport path is branched into a main pass and a bypass. A deflector is provided at a branch point, for switching the path either to the bypass or to the main pass. Sheet detection switches are respectively provided along the bypass and the main pass, and also on a stapler plate, for controlling the rotation of a transfer roller. In this way, a first sheet being transported through the main pass and a second sheet being transported through the bypass can be discharged onto the stapler plate at the same time. As a result, the problem of the device being made larger or reducing the quality of the sheets can be prevented, and a faster process after copying can be achieved.

Description: FIELD OF THE INVENTION The present invention relates to a device according to the preamble of claim 1, for further processing after copying, provided for image forming apparatuses such as copying machines, laser printers, etc., such process being the binding and/or punching of a plurality of copied sheets. BACKGROUND OF THE INVENTION Recently, many copying machines are combined with automatic document feeders and devices for further processing after copying such as binding or punching the copied sheets in order to automate the process. The automatic document feeder is placed on a document tray of the copying machine, for example, for transporting a plurality of documents one by one onto the document tray of the copying machine. The device for further processing after copying is for carrying out a process after copying, such as stapling, punching, etc., on every predetermined number of sheets fed from the copying machine. A device according to the preamble of claim 1 is disclosed in document EP-A-0,315,734 A1. Document EP-A-0,315,734 A1 discloses a sheet handling apparatus including a first sheet transport path and a second sheet transport path branched therefrom. The first sheet transport path and the second sheet transport path join together at the downstream side. The sheet handling apparatus is arranged such that the first sheet having an original copied thereto after having gone through a cycle is held in the second sheet transport path, while passing the second sheet to the first sheet transport path, and a timing is adjusted so that the first and second sheets can be discharged onto a processing tray at the same time. The device disclosed in Japanese Laid-Open Publication 144370/1990 (Tokukaihei 2-144370) corresponding to EP-A-0 371 403 as an example of the conventional device for further processing after copying has the following arrangement. As shown in Fig. 29(a), first, the copied sheets S being transported from the side of a main body 301 are stacked on a stapler plate 302 where the copied sheets S are aligned. Then, the sheets S are bound by a stapler 303 provided within the device. Thereafter, the bound set of sheets S is sandwiched between discharge rollers 304 and 305 to be discharged onto a discharge tray 306. The device is also provided with first and second transport paths 308a and 308b, whose lengths are different, placed between an entry opening 307 for the sheets S on the side of the main body 301 and the stapler plate 302. Furthermore, a deflector 309 is provided at a branch point between the first and the second transport paths 308a and 308b so as to switch the transport path for the sheet either to the first path 308a or to the second path 308b. Here, the first path 308a is set longer than the second path 308b, and the downstream of the first path 308a joins again the second path 308b. A discharge roller 310 is provided at the end of the path for releasing the sheets S onto the stapler plate 302 through the path. As shown in Fig. 29(a), when binding a plurality of sets of sheets S, the device for further processing after copying operates as follows. While a predetermined binding operation is carried out on a first set of sheets S on the stapler plate 302, a first sheet S 1 of the next set fed from the main body 301 is transported through the first path 308a, and a second sheet S 2 of the next set is transported through the second path 308b. With this arrangement, the second sheet S 2 is stacked on the first sheet S 1 so as to be discharged onto the stapler plate 302 through the discharge roller 310 at the same time as shown in Fig. 29(b). As a result, the time loss due to the time required for binding the first set of sheets S can be reduced, thereby permitting a faster binding process. The first and the second sheets S 1 and S 2 released onto the stapler plate 302 at the same time are sandwiched between the rollers 304 and 305. In this state, the ends of the sheets S 1 and S 2 are respectively aligned by rotating the discharge roller 305 in an opposite direction to its rotation direction for discharging the sheets S. As described, the first transport path 308a is set longer than the second transport path 308b so as to release the first and the second sheets S 1 and S 2 onto the stapler plate 302 at the same time. This arrangement enables a faster process for binding a plurality of sheets S. However, in the case of adopting sheets S of a large size, the transport paths must be set long in order to maintain the above arrangement. This makes the size of the device larger. In order to avoid the device being made larger, the first and the second transport paths 308a and 308b may be curved instead of being straight. However, this makes the transport paths for the sheets S complicated, and is likely to create the problem of lowering the quality of the bound set of sheets S by being creased. With the above arrangement, when aligning the ends of the discharged sheets S 1 and S 2 , the sheets S 1 and S 2 are sandwiched between the rollers 304 and 305, and are aligned by rotating the discharge roller 305 in the opposite direction. However, it is difficult to precisely align a stack of the sheets S 1 and S 2 , thereby lowering the quality of the bound set of sheets S. The device for further processing after copying having the above configuration is shown in Figs. 30(a)(b) and Fig. 31. In the case of the staple mode wherein the sheets S being transported from the side of the main body 301 are bound before being discharged out of the device, the copied sheets S, which have been transported from the side of the main body 301 through the transport path 311, are aligned on the stapler plate 312 as shown in Fig. 30(a). Then, the sheets S are bound by the stapler 313 provided within the device, thereafter the bound set of sheets S is discharged onto a discharge tray 316 using the rotation of a discharge roller 314 and the forward motion of a push-out member 315. On the other hand, in the case of the offset mode wherein the sheets S being transported from the side of the main body are discharged one by one out of the device without being further processed after copying, the sheets S are discharged as follows. As shown in Fig. 30(b), a driven roller 317 placed above the discharge roller 314 is rotated so as to be in contact with the discharge roller 314. Then, the copied sheets S being transported through the transport path 311 from the side of the main body 301 are sandwiched between the rollers 314 and 317 to be directly discharged onto the discharge tray 316. Further, the device shown in Fig. 31 is provided with an offset tray 324 for placing thereon the sheets S in the offset mode separately from a staple tray 329 for placing thereon the sheets S in the staple mode. With this arrangement, in the case of the offset mode, with a path switching operation of the deflector 322, first the sheets S being transported from the side of the main body 301 are passed through the first transport path 321a. Then, the sheets S are sandwiched between the discharge rollers 323 to be discharged onto the discharge tray 324. On the other hand, in the staple mode, with the path switching operation of the deflector 322, the sheets S being transported through the second transport path 321b are aligned on the stapler plate 325. Then, the sheets S are bound by the stapler 326 provided in the device, and are discharged onto the discharge tray 329 with the rotation of the discharge roller 327 and the forward motion of the push-out member 328. In the conventional device shown in Figs. 30(a)(b), the sheet transporting direction in the offset mode is different from the sheet transporting direction in the staple mode, and the sheets S are discharged onto the same discharge tray 316 in both modes. However, since the tray angle of the discharge tray 316 is constant, the ability to discharge sufficient in both modes is difficult to be obtained. Moreover, there is a level difference between the discharge roller 314 and the stapler plate 312 which causes the buckling and the creasing of the bound set of sheets S. On the other hand, in the device of Fig. 31 provided with the offset tray 324 and the stapler tray 329, the tray angles are separately set for the trays 324 and 329 so as to satisfy the ability to discharge in both modes. However, since the relative positions between the stapler tray 329 and the stapler plate 325 are not improved, the problem that the quality of the sheets is lowered due to the creasing of the bound set of sheets S still exists. Furthermore, the discharge tray 316 of the device shown in Figs. 30(a)(b) has a recessed portion 316a shown in Fig. 33 at the corner on the side of the device so that the stapled corners St of the bound set of sheets S drop by the dead weight of the corners St into the recessed portion 316a. In this way, the preciseness in aligning the bound sets of sheets S on the discharge tray 316 can be improved. As described, the alignment of the bound sets of sheets S on the discharge tray 316 can be improved by making the stapled corners St of the bound sets of sheets S drop into the recessed portion 316a by the dead weight of the corners St. However, with the above arrangement, the number of the corners St which drop into the recessed portion 316a differs depending on the number of the bound sets of sheets S to be placed on the discharge tray 316 and on the material used for the sheets S. For this reason, in the case where the number of the bound sets of sheets S to be placed is large, or thicker paper is used for the sheets S, since there is a limit which the recessed portion 316a can accept the stapled corners St dropped by the dead weight of the corners St, the stapled corners St may be pushed back, which reduces the preciseness in aligning the bound sets of sheets S. The acceptable number of the stapled corners St to be dropped into the recessed portion 316a may be slightly improved by making larger the area of the recessed portion 316a. However, the area of the recessed portion 316a to be formed on the discharge tray 316 also has a limit. Therefore, it is difficult to accurately drop the stapled corners St into the recessed portion 316a. SUMMARY OF THE INVENTION An object of the present invention is to provide a device for further processing after copying which permits a plurality of sheets to be processed in a shorter time and which ensures the quality of the processed sheets. An advantage of the present invention is to provide a device for further processing after copying which permits a more precise alignment of the processed sheets discharged out of the device. In order to achieve the object, the device for further processing after copying in accordance with the present invention includes at least the features as indicated in Claim 1. Further, the device for further processing after copying of the present invention operates as follows. While a current set of sheets is being processed by the means for processing after copying, the transport control means stops transporting a first sheet of the next set to be fed into the device through the first path, and transports a second sheet of the next set through the second path so as to release the first sheet and the second sheet of the next set onto the sheet holding means at the same time when the first processed set has been discharged. According to the above arrangement, with a control of the transport control means, while the current set of sheets is being processed, the transportation of the first sheet of the next set is temporarily stopped. As a result, the first and the second sheets of the next set are released onto the sheet holding plate at the same time. This permits a reduction in time loss due to the process after copying without making the device larger nor lowering the quality of the processed sheets even when sheets of a large size are adopted, and also permits a faster process after copying. According to the above arrangement, with the control of the support control means, the first sheet of the next set to be fed into the device is temporarily supported by the support means. As a result, the first and the second sheets of the next set are released onto the sheet holding plate at the same time. This permits a faster process after copying. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal sectional view showing a copying machine adopted in an embodiment of the present invention. Fig. 2 is a longitudinal sectional view showing the device for further processing after copying contained in the copying machine. Fig. 3 is an explanatory view showing each sheet detection switch provided along a transport path of the device for further processing after copying. Fig. 4 is an explanatory view showing a sheet detection switch composed of discharge rollers of the device for further processing after copying. Fig. 5 is a perspective view showing an actuator provided on the discharge roller. Figs. 6(a)(b) are explanatory views respectively showing upper limit detecting operations for the discharge tray by the actuator. Fig. 7 is a perspective view showing a recessed portion formed on the discharge tray. Fig. 8 is a longitudinal sectional view showing a spring provided on the discharge tray. Fig. 9 is a flow chart showing a process in an offset mode with a device for further processing after copying. Fig. 10 is a flow chart showing a process in a single staple mode with a device for further processing after copying. Fig. 11 is a flow chart showing a part of a process in a multiple staple mode with the device for further processing after copying. Fig. 12 is a flow chart showing a part of a process in a multiple staple mode with the device for further processing after copying. Fig. 13 is a flow chart showing a part of a process in a multiple staple mode with the device for further processing after copying. Fig. 14 is a flow chart showing a part of a process in a multiple staple mode with the device for further processing after copying. Fig. 15 is a flow chart showing a part of a process in a multiple staple mode with the device for further processing after copying. Figs. 16(a)(b)(c) are explanatory views respectively showing sheet transporting operations through the transport path in the multiple staple mode. Figs. 17(a)(b)(c) are explanatory views respectively showing bound sheets aligning operation on the discharge tray in the multiple staple mode. Fig. 18 is a perspective view showing a plurality sets of bound sheets being stacked. Fig. 19 is a perspective view showing the bound sheets stacked on the discharge tray. Figs. 20(a)(b) are explanatory views respectively showing the bound sheets sandwiched between the discharge roller and the discharge tray. Figs. 21(a)(b) are explanatory views respectively showing a tray angle between a support face and a resting face, which varies depending on the volume of the bound sheets to be stacked on the discharge tray. Fig. 22 is an explanatory view showing a buckling of the bound sheets on the discharge tray due to a level difference between the support face and the resting face. Fig. 23 is a longitudinal sectional view showing a sponge roller capable of rotating around the rotation axis of the discharge roller. Fig. 24 is an explanatory view showing an angle change means composed of a cam unit. Fig. 25 is an explanatory view showing an angle change means composed of a crank unit. Fig. 26 is an explanatory view showing a device for further processing after copying used in one embodiment of the present invention. Fig. 27 is an explanatory view showing a transport path of the device for further processing after copying. Figs. 28(a)(b)(c) are explanatory views respectively showing the sheet transport operations through the transport path. Figs. 29(a)(b) are explanatory views respectively showing sheet transporting operations through the transport path in the conventional device for processing after copying. Fig. 30(a) is an explanatory view showing a process in the staple mode with the conventional device for further processing after copying. Fig. 30(b) is an explanatory view showing a process in an offset mode with the conventional device for further processing after copying. Fig. 31 is a longitudinal sectional view showing another conventional device for further processing after copying. Fig. 32 is an explanatory view showing the state where the sheets are discharged onto the conventional discharge tray. Fig. 33 is a perspective view showing the conventional discharge tray having a recessed portion. DESCRIPTION OF THE EMBODIMENT [BASIC STRUCTURE AND BASIC FUNCTION] The following description will discuss an image forming apparatus to which the present invention is applied with reference to Figs. 1 through 25. The description is given through the case where a device for further processing after copying is contained in a copying machine. As shown in Fig. 1, the copying machine adopted has a main body 1 which copies an image on a document M to a sheet S. Further, a document feeder 30 is provided above the main body 1, which transports the document M to an exposure area 2 formed on the top surface of the main body 1. A glass plate 3 having the exposure area 2 formed on the surface thereof is placed on the upper side of the main body I. Further, an optical system 9 and a photoreceptor drum 10 are placed under the glass plate 3. The optical system 9 includes a light source 4, mirrors 5, 6, and 7, and a lens 8. The optical system 9 is provided for scanning the document M using a light emitted from the light source 4, the document M being transported to the exposure area 2 by the document feeder 30 (to be described later). Further, a reflected light is projected onto an exposure point A on the surface of the photoreceptor drum 10 through mirrors 5, 6 and 7, and the lens 8. As a result, a static latent image is formed on the surface of the photoreceptor drum 10 which is uniformly charged by a main charger unit 11 (to be described later), the static latent image corresponding to the image on the document M. A main charger unit 11, a developer unit 12, a transfer charger 13, and a separation charger 14 are provided along the circumference of the photoreceptor drum 10. As described, the main charger unit 11 charges the surface of the photoreceptor drum 10 to a predetermined electric potential. The developer unit 12 develops the electrostatic latent image formed on the surface of the photoreceptor drum 10 to be a toner image. Then, the transfer charger 13 transfers the toner image onto the sheet S which has been transported through a sheet transport path 15 (to be described later). In addition, the separation charger 14 is provided for separating the sheet S, whereon the toner image is to be transferred, from the photoreceptor drum 10. A sheet transport path 15 is provided under the photoreceptor drum 10, for transporting the sheets S, whereon the toner image is to be transferred. Further, a feed board 19, a feed cassette 20, and a feed deck 21 are placed on the upstream of the sheet transport path 15, respectively provided with feed rollers 16, 17 and 18. It is arranged such that the sheets S placed on the feed plate 19 or the feed deck 21, or the sheets S stored in the feed cassette 20 are fed to the photoreceptor drum 10 through the sheet transport path 15. On the downstream of the sheet transport path 15, a transport belt 22 and a fuser 23 are provided. The transfer belt 22 transports the sheet S whereon the toner image has been transferred. The toner image is made permanent on the sheet S by the fuser 23. On the downstream of the fuser 23, a deflector 24 is provided by which a feeding path of the sheet is branched into both a path connected to a device 40 for further processing after copying (to be described later), and a re-transport path 25. The re-transport path 25 serves as a recirculation path through which the sheet S, whereon the toner image has been transferred by the photoreceptor drum 10, is transported again to the photoreceptor drum 10. Further, an intermediate tray 26 is provided along the path, which allows copying on both sides of the sheet S. The document feeder 30 has a document transport path 31 for transporting the document M to the exposure area 2 formed on the top surface of the main body 1. The document transport path 31 serves as a recirculation path, and is provided with a document tray 32 (whereon the document M is placed), a feed belt 33, and a transport belt 34. The feed belt 33 is provided for feeding the document M placed on the document tray 32 to the exposure area 2 in order. The transport belt 34, which forms a transport path between the glass plate 3 and itself, is in contact with the glass plate 3 having the exposure area 2 formed on the surface thereof. The document feeder 30 feeds the document M placed on the document tray 32 to the exposure area 2. Further, the document feeder 30. sets the document M at a predetermined position on the glass plate 3 by the transport belt 34 so that the document M becomes ready to be scanned by the described light source 4. Further, the copying machine adopted in the present embodiment is provided with the device 40 for further processing after copying at the lower end of the sheet transport path 15. As shown in Fig. 2, the device 40 of the present embodiment is provided with a transport path 41 (to be described later), binding means 45 (means for processing after copying), sheet discharge means 51, and a discharge tray 56. The transport path 41 transports the sheet S fed from the main body 1 within the device 40. The binding means 45 arranges the sheets S and bind them using a stapler. The sheet discharge means 51 discharges the arranged and bound set of sheets S from the device 40. The bound set of sheets S discharged from the device 40 is placed on the discharge tray 56. The transport path 41 has an entry opening 41a formed on one end thereof, through which the sheets S are fed from the main body 1. The transport path 41 is branched into upper and lower paths, i.e., a bypass 41b (second path) and a main pass 41c (first path). The transport path 41 is further provided with a pair of upper and lower transport rollers 42 and 43 (sheet transport means), placed at respective ends of the bypass 41b and the main pass 41c, and a deflector 44 placed at a branch point between the bypass 41b and the main pass 41c. The deflector 44, which serves as a means for switching the path, is capable of rotating in the direction of B 1 - B 2 , and switches the transport path for the sheet S either to the bypass 41b or to the main pass 41c. As shown in Fig. 3, the transport path 41 is provided with sheet detection switches SW 1 and SW 2 (for detecting the sheet S), respectively placed along the bypass 41b and the main pass 41c. With the respective detections of the sheets S by the sheet detection switches SW 1 and SW 2 , and another sheet detection switch (not shown) provided on the stapler plate 46 (to be described later), the rotation of the transport roller 43 is controlled. The rotation of the transport roller 43 is also controlled by a timer (not shown). Namely, the transport control means of the present invention is composed of sheet detection switches SW 1 and SW 2 , and another sheet detection switch (not shown) for detecting the sheets S, provided on the stapler plate 46 (to be described later). The binding means 45 is composed of the stapler plate 46 (whereon the process after copying is carried out), an edge aligner 47, a paddler 48, and a stapler 49. The stapler plate 46, placed under the transport path 41, is provided with a discharge opening 40a having one end attached to the side surface of the device 40. The other end of the stapler plate 46 is placed at a lower level than the end attached to the side surface so as to form a slope. The sheets S to be bound (stapled) are placed on the stapler plate 46. As mentioned earlier, the sheet detection switch (not shown) on the stapler plate 46 is provided for detecting whether or not the sheet S exists on the stapler plate 46. The edge aligner 47, provided at substantially the center of the stapler plate 46, is capable of moving up and down in the direction perpendicular to the sheet surface of Fig. 2. The edge aligner 47 is provided for aligning the sides of the sheets S placed on the stapler plate 46. The paddler 48, which is capable of moving in the direction of arrow C, is provided so that a blade section is in contact with the lower end surface of the stapler plate 46. The paddler 48 is provided for aligning the ends of the sheets S placed on the stapler plate 46. The stapler 49 is placed beside the stapler plate 46 having the paddler 48 attached thereto. The stapler 49 is provided for binding the sheets S placed on the stapler plate 46. A stopper 50 is also provided at the lower end of the stapler plate 46 which aids the paddler 48 in aligning the ends of the sheets S by stopping the rear edges of the sheets S. The sheet discharge means 51 is composed of a push-out member 52 and discharge rollers 53 and 54. The push-out member 52 is placed along an extended line from the lower end of the stapler plate 46, and is capable of moving forward and backward in the direction of D 1 - D 2 along the top surface of the stapler plate 46. The push-out member 52 pushes out the sheet S, placed on the stapler plate 46, towards the discharge opening 40a after the sheets S are bound. The discharge roller 53 is placed so that its rotation axis is supported by the upper end of the stapler plate 46, and is capable of rotating in the direction of G 1 - G 2 . On the other hand, the discharge roller 54 is provided so that its rotation axis is supported by the end of an arm member 55, the other end being capable of rotating around a fulcrum E in the direction of F 1 - F 2 . When it is set in the staple mode (to be described later), the discharge roller 53 serves to aid in aligning the ends of the sheets S, placed on the stapler plate 46, by rotating in the direction of G 2 . On the other hand, the discharge roller 53 discharges the bound set of sheets S by rotating in the direction of G 1 after the sheets S are bound. When it is set in the offset mode (to be described later), the discharge roller 54 is arranged so as to sandwich the sheets S between the discharge roller 53 and itself, and discharges the sheet S onto the discharge tray 56 directly from the transport path 41 as the arm member 55 rotates in the direction of F 2 with the rotation of the discharge roller 53 in the direction of G 1 . In addition, in the offset mode, the discharge rollers 53 and 54 become the sheet detection switch SW 3 for detecting the sheet S when they are in contact with one another. The discharge tray 56 is fitted in the device 40 under the discharge roller 53. An elevator unit 57 and a shift unit 58 are provided in the vicinity of the portion attached to the device. Therefore, the discharge tray 56 can move both in the up-down direction of H 1 - H 2 and in the direction perpendicular to the plane of Fig. 2, so that the position of the discharge tray 56 is adjusted according to the sheets S to be held. The forward motion of the discharge tray 56 in the direction of H 1 has an upper limit detected by the actuator 59 provided on the discharge roller 53 as shown in Fig. 5. Furthermore, as shown in Figs. 6(a)(b), the actuator 59 rotates in the direction of J around a fulcrum I with the forward motion of the discharge tray 56 in the direction of H 1 so as to insert an edge part of the actuator 59 into a sensor 60. As a result, the discharge tray 56 is stopped at the position where the sheet S is sandwiched between the discharge roller 53 and itself. The portion attached to the device of the discharge tray 56 is made concave so as to form a resting face 56a for the discharge roller 53. Furthermore, the corner of the surface facing the discharge roller 53 is recessed as shown in Fig. 7 to be a recessed portion 56b so that the stapled corners St of complete sets (to be described later) drop into the recessed portion 56b. The support face 56c for the sheets of the discharge tray 56 is set parallel to the top surface of the stapler plate 46. As shown in Fig. 8, the discharge tray 56 is arranged as follows. The support face 56c is provided at the lower end of the resting face 56a so as to be capable of rotating around a fulcrum K. Further, the resting face 56a is provided so as to be capable of rotating around the corner L at the upper end of the resting face 56a. Furthermore, a spring 61 (angle change means) is provided at the fulcrum K so that the tray angle α between the support face 56c and the resting face 56a varies in response to the sheets S placed on the discharge tray 56. With the above arrangement of the device 40, the following will explain the process for transporting the sheets S. Here, the explanation is given for each of an offset mode, a single staple mode, and a multiple staple mode. In the offset mode, the sheets S transported from the main body 1 are discharged one by one onto the discharge tray 56 without being further processed. Whereas, in the single staple mode, the sheets S, transported from the main body 1, go through a predetermined binding process. Then, the bound set of sheets S (hereinafter referred to as a complete set) is discharged onto the discharge tray 56, and accordingly, a plurality of complete sets are discharged set by set in the multiple staple mode. The flowchart of Fig. 9 explains the process in the offset mode. First, the device 40 receives a signal of an offset number from the main body 1 (S1). Then, the offset number is set in the device 40 (S2). Next, the device 40 receives a signal to start the operation from the main body 1 (S3). Then, the process is started (54), and the processed number is cleared (S5). The sheet S, whereon the image on the document M is copied in the main body 1, is fed into the device 40 through the entry opening 41a. It passes through the main pass 41c, and is sandwiched between the discharge rollers 53 and 54. Then, it is discharged onto the discharge tray 56. This transportation of the sheet S through the main pass 41c is detected as the sheet detection switch SW 2 is turned ON (S6). Similarly, the transporting and passing of the sheet S between discharge rollers 53 and 54 are detected as the sheet detection switch SW 3 is turned ON (S7) and OFF (S8). Then, the processed number increases by 1 (S9). Then, it is determined whether or not the processed number coincides with the offset number (S10). If not, the sequence goes back to S6. If so, the processed number is cleared (S11). Thereafter, the descending of the discharge tray 56 (S12), setting of the offset number (S13), and ascending of the discharge tray 56 (S14) are executed in order. Then, it is determined whether or not the device 40 received a signal to stop the operation from the main body 1 (S15). If not, the sequence goes back to S6. If so, the process is ended (S16), and the above sequence in the offset mode is terminated. The flow chart of Fig. 10 explains the process in the single staple mode. First, the device 40 receives a number of sheets to be stapled from the main body 1 (S21). Then, the number is set in the device 40 (S22). Next, the device 40 receives a signal to start the operation from the main body 1 (S23). Then, the process is started (S24), and the processed number is cleared (S25). The sheet S, whereon the image on the document M is copied in the main body 1, is fed into the device 40 through the entry opening 41a, and passes through the main pass 41c. Then, it is discharged onto the stapler plate 46. This transportation of the sheet S through the main pass 41c is detected as the sheet detection switch SW 2 is turned ON (S26) and OFF (S27). As a result, the timer set in the device 40 is cleared (S28). Then, the processed number increases by 1 (S29). After a predetermined time set by the timer has passed (S30), it is determined that the discharge of the sheet S onto the stapler plate 46 has completed, and the sides of the sheets S, placed on the stapler plate 46, are aligned by the edge aligner 47 (S31). Then, it is determined whether or not the processed number coincides with the offset number (S32). If not, the sequence goes back to S26. If so in S32, the processed number is cleared (S33). Then, with the rotation of the paddler 48 in the direction of C, and the rotation of the discharge roller 53 in the direction of C 2 , the ends of the sheets S, placed on the stapler plate 46, are aligned, and the sheets S are bound by the stapler 49 (S34). Then, the complete set is discharged onto the discharge tray 56 from the stapler plate 46 using the forward motion of the push-out member 52 in the direction of D 1 and the rotation of the discharge roller 53 in the direction of G 1 (S35). Then, after the discharge tray 56 has been adjusted (S36), the device 40 receives a signal to end the operation from the main body 1 (S37). Then, the process is ended (S38), and the above sequence in the staple mode is terminated (single). The flow charts of Figs. 11 through 15 explain the process in the multiple staple mode. First, the device 40 for further processing after copying receives a number of sheets to be stapled from the main body 1 (S41). Then, the number is set in the device 40 (S42). Next, the device receives a signal to start the operation from the main body 1 (S43). Then, the process is started (S44), and the processed number is cleared (S45). Each of the sheet S, whereon the image on the document M is copied in the main body 1, is fed into the device 40 through the entry opening 41a, and passes through the main pass 41c. Then, the sheets S are discharged onto the stapler plate 46. This transportation of the sheets S through the main pass 41c is detected as the sheet detection switch SW 2 is turned ON (S46). Then, it is checked whether or not the sheet detection switch SW 2 is turned OFF (S47). If the sheet detection switch SW 2 is still turned ON in S47, the sequence moves on to S48 where it is determined whether or not the complete set has been discharged from the stapler plate 46. If not in S48, the complete set is discharged onto the discharge tray 56 using the push-out member 52 and the discharge roller 53 (S49). Then, the sequence goes back to S47. On the other hand, if the complete set has been discharged from the stapler plate 46, the sequence moves on to S50 where it is determined whether or not the adjustment of the discharge tray 56 has been completed. If so, the sequence directly goes back to S47. If not, the discharge tray 56 is adjusted (S51) before the sequence moves on to S47. When it is detected that the sheet detection switch SW 2 is turned OFF in S47, the timer set in the device 40 is cleared (S52), and then the processed number increases by 1 (S53). Then, it is checked whether or not the processed number is 1 (S54). If not, the sequence skips to S66 (to be described later). If so, the sequence moves on to S55 where it is determined whether or not the stapler plate 46 is ready. If so, the sequence skips to S66. If not, the rotation of the transport roller 43 is stopped so as to stop the transportation of the sheet S (S56). Then, the deflector 44 is rotated in the direction of B 1 so as to switch the transport path for the sheet S to the bypass 41b (S57). Next, it is determined whether or not the second sheet S is being transported through the bypass 41b by detecting whether or not the sheet detection switch SW 1 is turned ON (S58). When it is detected that the sheet detection switch SW 1 is not turned ON in S58, the sequence moves on to S59 where it is determined whether or not the complete set has been discharged. If not, the complete set is discharged on the discharge tray 56 using the push-out member 52 and the discharge roller 53 (S60). Then, the sequence goes back to S58. If so, the sequence moves on to S 61 where it is determined whether or not the adjustment of the discharge tray 56 has been completed. If so, the sequence directly moves back to S58. If not, the discharge tray 56 is adjusted (S62) before the sequence moves back to S58. Then, immediately after the sheet detection switch SW 1 is turned ON in S58, the sheet detection switch SW 1 is turned OFF in preparation for the next set of sheets (S63). With the detection of the OFF state of the switch SW 1 , the deflector 44 rotates in the direction of B 2 , and the transport path for the sheets S is switched to the main pass 41c (S64). In the meantime, with the rotation of the transport roller 43, the transportation of the first sheet S 1 is restarted (S65). As a result, the first sheet S having passed through the main pass 41c, and the second sheet S having passed through the bypass 41b are discharged on the stapler plate 46 at the same time. Then, the sequence moves back to S52 where the timer set in the device 40 is cleared, and the processed number increases by 1 (S53). Then, the sequence moves on to S54. In S54, if it is detected that the processed number is not 1, the sequence skips to S66 where it is determined whether or not a predetermined time set by the timer has passed. After the predetermined time set by the timer has passed, it is determined that the sheet S has been discharged onto the stapler plate 46, and the sides of the sheets S, placed on the stapler plate 46, are aligned by the edge aligner 47 (S67). Then, it is determined whether or not the processed number coincides with the number of sheets S to be stapled (S68). If not, the sequence goes back to S46. If so, the processed number is cleared (S69). Then, with the rotation of the paddler 48 in the direction of C, and the rotation of the discharge roller 53 in the direction of G 2 , the ends of the sheets S, placed on the stapler plate 46, are aligned, and the sheets S are bound using the stapler 49 (S70). Then, the sequence moves back to S46. If the sheet S is no longer detected by the sheet detection switch SW 2 in S46, the sequence moves on to S71 where it is determined whether or not the complete set has been discharged from the stapler plate 46. If not, the complete set is discharged onto the discharge tray 56 using the push-out member 52 and the discharge roller 53 (S72). Then, the sequence goes back to S46. If so, the sequence moves on to S73 where it is determined whether or not the adjustment of the discharge tray 56 has been completed. If not, the discharge tray 56 is adjusted (S74) before the sequence moves on to S46. If so, the sequence moves on to S75 where it is determined whether or not the device 40 receives a signal to end the operation from the main body 1. If not, the sequence moves back to S46. If so, the process is ended (S76), and the above sequence in the multiple staple mode is terminated. The device 40 for further processing after copying of the present embodiment is arranged as follows. In the multiple staple mode, if the ON state of the sheet detection switch SW 1 is not detected (S58) within a predetermined time after the time set by the timer is cleared (S52), the rotation of the transport roller 43 is automatically restarted. In this way, only the first sheet S 1 can be discharged onto the stapler plate 46 without waiting for the synchronous discharge of the second sheet S. As described, the device 40 for further processing after copying has the transport path 41 which is branched into the bypass 41b and the main pass 41c. Further, the deflector 44 is placed at the branch point between the bypass 41b and the main pass 41c. Along the paths 41b and 41c, the sheet detection switches SW 1 and SW 2 are respectively provided, and the sheet detection switch (not shown) is provided on the stapler plate 46 in order to control the rotation of the transport roller 43. With the above arrangement of the device 40 for further processing after copying, when it is set in the multiple staple mode, while the first set of sheets S is being bound on the stapler plate 46, the first sheet S 1 of the second set is being transported through the main pass 41c. Thereafter, the rotation of the transport roller 43 is stopped so as to temporarily stop the transportation of the sheet S 1 as shown in Fig. 16(a). As shown in Fig. 16(b), with the switch of the deflector 44, a second sheet S 2 of the second set is transported through the bypass 41b so as to reduce the time loss due to the time required for binding the first set of sheets S. Then, the rotation of the transport roller 43 is restarted so as to restart the transportation of the first sheet S 1 . As a result, the first sheet S 1 and the second sheet S 2 are discharged onto the stapler plate 46 (wherefrom the first set of sheets S was discharged), at the same time as shown in Fig. 16(c). The sheets S 1 and S 2 discharged at the same time onto the stapler plate 46 are sandwiched between the rollers 53 and 54 with the rotation of the arm member 55 in the direction of F 2 . In this state, the end of the first sheet S 1 is aligned by the rotation of the discharge roller 53 in the direction of G 2 ; whereas, the end of the second sheet S 2 is aligned by the rotation of the paddler 48 in the direction of C. This means that the respective ends of the sheets S 1 and S 2 being stacked on the stapler plate 46 are aligned separately, and a precise alignment can be obtained. As a result, high quality binding operations can be maintained. In addition, the timer for controlling the rotation of the transport roller 43 is provided in the described device 40 for further processing after copying. Therefore, when it is set in the multiple staple mode, even if the second sheet S 2 is not transported through the bypass 41b within the predetermined time as a result of being stuck in the device, the first sheet S 1 is automatically discharged onto the stapler plate 46. This avoids the external force from the transport roller 43 being exerted on the sheet for a long time, which prevents a change in the shape of the first sheet S 1 . The following will describe the process for aligning the sheets S placed on the discharge tray 56 using the discharge roller 53 and the discharge tray 56. The explanation will be given through the case of the multiple staple mode in which precise alignment of the sheets is necessary. First, as shown in Fig. 17(a), the complete set of sheets S having gone through the binding process on the stapler plate 46 is discharged on the support face 56c using both a forward motion of the push-out member 52 in the direction of D 1 , and the rotation of the discharge roller 53 in the direction of G 1 . When the complete set has been discharged onto the support face 56c, the discharge tray 56 moves downward in the direction of H 2 for the maximum number of complete sets set beforehand. Next, as shown in Fig. 17(b), the push-out member 52 moves downward in the direction of D 2 after discharging the complete set as described above, in preparation for the next binding process. On the other hand, the discharge tray 56, which supports the complete set, moves upward in the direction of H 1 to the position at which the complete set is sandwiched between the discharge roller 53 and itself. Then, as shown in Fig. 17(c), the complete set, which is sandwiched between the discharge roller 53 and the discharge tray 56, is transported in the direction of N with the rotation in the direction of G 1 of the discharge roller 53. In the meantime, the rear edge of the complete set is aligned by the stopper 62, and the set of sheets is aligned on the discharge tray 56. In the above process for aligning the complete sets on the discharge tray 56, the stapled corner St of the complete set becomes thicker than the other part of the complete set as a plurality of complete sets are stacked as shown in Fig. 18. However, by the dead weight of the complete set, the stapled corners St of the complete sets fall into the recessed portion 56b as shown in Fig. 19. Moreover, even when the stapled corner St of the complete set cannot fall in the recessed portion 56b by its dead weight as shown in Fig. 20(b), by pressing the complete set by the discharge roller 53 onto the discharge tray 56, the stapled corner St is pressed into the recessed portion 56b. In this way, the lowering of the quality of the binding operation on the discharge tray due to the spring of the stapled corner St can be prevented. Furthermore, when the complete set is placed on the discharge tray 56 thus described the discharge tray 56 of the device for further processing after copying 40 is arranged such that a spring 61 shrinks according to the volume of the complete set placed on the support face 56c, and the tray angle α between the support face 56c and the resting face 56a changes. With this arrangement, when the volume of the complete set on the discharge tray 56 is small as shown in Fig. 21(a), the spring 61 hardly shrinks. Therefore, the support face 56c of the discharge tray 56 is on substantially the same plane as the top surface of the stapler plate 46 so as to support the complete set to be appropriately discharged from the stapler plate 46. On the other hand, when the volume of the complete sets on the discharge tray 56 is large as shown in Fig. 21(b), the spring 61 shrinks by the dead weight of the complete set. As a result, the tray angle α between the support face 56c and the resting face 56a becomes substantially 180°. This prevents the bulge of the sheets S due to the difference in the slopes between the support face 56c and the resting face 56a. In addition, the present invention is not intended to be limited to the above preferred embodiment, it can be varied in many ways within the scope of the present invention. For example, according to the arrangement of the present embodiment, with the upward motion of the discharge tray 56, which supports the complete set in the upward direction, the complete set is sandwiched between the discharge roller 53 and the discharge tray 56, and the present invention is not intended to be limited to this arrangement. Other than the above arrangement, for example, as shown in Fig. 23, if a sponge roller 63 is provided, so as to be capable of rotating in the direction of O 1 - O 2 around the rotation axis of the discharge roller 53, and an interlocking belt 64 is provided so as to surround the sponge roller 63 and the discharge roller 53, the sponge roller 63 rotates in the direction of O 1 by its dead weight and rotates in the direction of P with the rotation in the direction of G 1 of the discharge roller 53 so as to sandwich the complete set on the discharge tray 56 between the sponge roller 63 and the discharge roller 53 in aligning the complete sets. With the above arrangement, the sponge roller 63, which sandwiches the complete set between the discharge tray 56 and itself is capable of rotating in the direction of O 1 - O 2 . Therefore, even if a deviation occurs in the stop position of the discharge tray 56, the sponge roller 63 absorbs the deviation. As a result, the pressing force exerted on the complete set can be maintained substantially constant. Moreover, as to the angle change means, which varies the tray angle α between the support face 56c and the resting face 56a of the discharge tray 56, it is not intended to be limited to the spring 61. Other than the spring 61, for example, counting means (not shown) can be provided for counting the volume of the complete set placed on the discharge tray 56. In this case, for example, by controlling the driving of the cam unit 65 of Fig. 24 or the crank unit 66 of Fig. 25, the tray angle α can be automatically controlled. As a note, the present invention does not intend to be limited to the above preferred embodiment, it can be varied in many ways within the scope of the present invention. In the above embodiment, the transport control means for controlling the rotation of the transport roller 43 is composed of the sheet detection switches SW 1 and SW 2 , and the sheet detection switch (not shown) provided on the stapler plate 46. However, the transport control means is not limited to the above arrangement. For example, by controlling the rotation of transport roller 42 as well as the rotation of the transport roller 43, the first sheet S 1 being transported through the main pass 41c and the second sheet S 2 can be discharged at the same time with a more subtle timing. [EMBODIMENT] The following description will discuss one embodiment of the present invention with reference to Figs. 26 through 28(a)(b)(c). For convenience, members having the same function as in the first embodiment will be designated by the same code and their description will be omitted. As shown in Fig. 26, a device 90 for further processing after copying is provided with a transport path 91 which is arranged as follows. The transport path 91 is composed of a linear path having an entry opening 91a and a pair of upper and lower feed rollers 92 at one end, so that the sheets S are fed into the device 90 from the main body 1. On the other end of the.linear path, a pair of upper and lower discharge rollers 93a and 93b are provided for discharging the sheets S fed through the entry opening 91a onto the stapler plate 46. The discharge rollers 93a and 93b are arranged as follows. While the sheet S is sandwiched between the discharge rollers 93a and 93b, the discharge roller 93a is driven, thereby discharging the sheet S. On the other hand, when the discharge roller 93a separates from the discharge roller 93b and the discharge roller 93a stops rotating, the discharging operation of the sheets S is stopped. As shown in Fig. 27, the device 90 for further processing after copying has a deflector 94 as a path switching means and a sheet pressing member 95 provided along the path between the feed rollers 92 and the discharge rollers 93a and 93b. Furthermore, a sheet detection sensor 96 is provided along the path between the entry opening 91a and the feed rollers 92. The deflector 94, which rotates in the direction of V 1 - V 2 , is provided so that the leading edge of the deflector 94 is at the side of feed rollers 92. On the other hand, the sheet pressing member 95, which rotates in the direction of W 1 - W 2 , is provided so that the leading edge of the sheet pressing member 95 is at the side of the discharge rollers 93a and 93b. Furthermore, a dividing plate 97 is provided between the deflector 94 and the sheet pressing member 95, which divides the path into the upper part and the lower part. The sheet detection sensor 96 detects the sheets S fed through the entry opening 91a. With the detection of the sheet S by the sheet detection sensor 96, the rotation of the deflector 94, the rotation of the sheet pressing member 95, and the discharge roller 93a are controlled. With the above arrangement, the following will describe the process for transporting the sheets S through the transport path 91 of the device for further processing after copying 90. The explanation is given through the case where the first and the second sheets of the second set are transported through the transport path 91 in the multiple staple mode. Other operations of the device 90 are fundamentally the same as the device 40 for further processing after copying of the first embodiment, thus the explanations thereof shall be omitted here. As shown in Fig. 28(a), when all of the sheets S of the first set are discharged on the stapler plate 46, the deflector 94 rotates in the direction of V 1 , and the sheet pressing member 95 rotates in the direction of W 1 , thereby forming the transport path below the dividing plate 97. Then, the first sheet S 1 of the next set fed through the entry opening 91a is transported through the path provided below the dividing plate 97 by the feed rollers 92. Next, after a predetermined time from when the sheet detection sensor 96 detects the rear edge of the first sheet S 1 , the discharge rollers 93a and 93b are released from the contact state with the sheet S 1 interposed in between as shown in Fig. 28(b). In the meantime, the discharge roller 93a stops rotating, thereby stopping the transportation of the first sheet S 1 . In this state, the sheet pressing member 95 holds the first sheet S 1 in the path by rotating in the direction of W 2 , and the deflector 94 switches the transport path provided above the dividing plate 97 by rotating in the direction of V 2 . Then, the second sheet S 2 fed through the entry opening 91a is transported through the path provided above the dividing plate 97. Next, after a predetermined time from when the sheet detection sensor 96 detects the rear edge of the second sheet S 2 , the sheet pressing member 95 releases the hold state of the second sheet S 2 in the path by rotating in the direction of W 1 , and the deflector 94 switches the transport path to the path provided below the dividing plate 97 by rotating in the direction of V 1 . The discharge roller 93a starts rotating with the first and the second sheet S 1 and S 2 interposed between the discharge roller 93b and itself, the first sheet S 1 and the second sheet S 2 are superimposed and discharged onto the stapler plate 46 at the same time. As described, the device 90 for further processing after copying has the transport path 91 composed of a linear path. Further, the deflector 94 and the dividing plate 97 are provided along the transport path 91 so that the transport path for the sheets S can be switched either to the upper path or to the lower path having the dividing plate 97 as a border. With this arrangement of the device 90 for further processing after copying, it is not necessary to divide the transport path into the main pass and the bypass, and the time loss due to the binding operation in the multiple mode can be reduced, thereby achieving faster binding operations in the multiple mode.

Claims: A device (90) for further processing after coping, comprising: sheet holding means (46) for placing thereon a plurality of sheets; a transport path (91) for guiding sheets fed into the device to said sheet holding means (46), said transport path (91) including an upper path and a lower path; path switching means (94, 95) for switching said transport path (91) either to the upper path or the lower path; sheet transport means (92, 93a, 93b) for transporting the sheets through said transport path (91); transport control means for controlling a transportation of a sheet to said sheet holding means (46) by controlling respective operations of said sheet transport means (92, 93a, 93b) and said path switching means (94. 95); means (45) for processing after copying, which carries out a predetermined process on a plurality of sheets stacked on said sheet holding means (46); and sheet discharge means (51) for discharging the processed set of sheets from said sheet holding means (46), wherein, while a current set of sheets is being processed by said means (45) for processing after copying, said transport control means passes a first sheet of the next set fed into the device through the lower path and thereafter temporarily stops the transportation of the first sheet and passes a second sheet of the next set through the upper path so as to discharge the first and second sheets of the next set onto said sheet holding means (46) at the same time when the current processed set of sheets has been discharged by said sheet discharge means (51), said device (90) being characterized in that an inside of said sheet transport path (91) is divided into the upper path and the lower path, and said sheet transport means (92, 93a, 93b) are disposed so as to share the upper path and the lower path. The device according to claim 1, wherein said transport path (91) includes a dividing plate (97), which divides said transport path (91) into the upper and lower paths. The device according to claim 2, wherein said path switching means (94, 95) includes: a deflector (94) rotatably provided at one end of a sheet entry side of said dividing plate (97); and a sheet pressing member (95) rotatably provided at the other end of a sheet discharge side of said dividing plate (97). The device according to claim 1, wherein said sheet transport means (92, 93a, 93b) includes: a feed roller (92) provided at one end of a sheet entry side of said transport path (91); and a discharge roller (93a, 93b) provided at the other end of a sheet discharge side of said transport path. The device according to claim 1, wherein said transport control means includes: a sheet detection switch (96) provided along a sheet entry side of said transport path (91); and a sheet detection switch provided on said sheet holding means.

Inventors: ANDO EIITI, ANDO TADAHIRO, MIURA HIROSHI, NAKA HIROSHI, NAKABAYASHI MASAYOSHI, OHATA TOMONORI, SAWADA MITSUTOSHI, SUZUKI KAORU, ANDO, EIITI, ANDO, TADAHIRO, MIURA, HIROSHI, NAKA, HIROSHI, NAKABAYASHI, MASAYOSHI, OHATA, TOMONORI, SAWADA, MITSUTOSHI, SUZUKI, KAORU
Applicants: SHARP KK, SHARP KABUSHIKI KAISHA
Application year: 1992
Main classification: G03G15
IPC codes: B65H29, B42C1, G03G15