JP2008184318A - Sheet post-processing device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet post-processing device capable of improving appearance and quality of a bundle of sheets after trimming by cutting a stapled part of a bundle of sheets and cut fore ends of the bundle of sheets for alignment. <P>SOLUTION: A bundle of sheets T after a stitching process is conveyed by a skew correcting conveyor belt 646, and an end of the bundle of sheets is made to abut on a stopper 641 so as to correct skew of the bundle of sheets T. The conveyor belt 646 (646a, 646b) conveys, by positioning in a position of a stitched part (a figure 5) by staples S and bringing in contact with the stitch part, and position of the conveyor belts 655 and 656 in the cross direction are arranged separate from the staples (needle) S being a stitched part of the bundle of sheets T. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is provided in an image forming apparatus such as a copying machine, a facsimile machine, a printer, and a multifunction machine, and performs a binding process or the like with a staple (needle) on a bundle of sheets such as recording paper for recording image information of a document. The present invention relates to a sheet post-processing apparatus.

  In the image forming apparatus, the image information of the original is read to form a toner image, and the recorded toner image is bundled and conveyed to a sheet post-processing apparatus. In the sheet post-processing apparatus, so-called saddle stitch binding is widely performed in which a sheet bundle is bound by a staple (needle) in the conveyance direction, for example, near the center, folded in two from a bound portion, and discharged in a booklet form. Further, many have been proposed in which the edge of a folded sheet bundle is trimmed by trimming with a cutting device to improve the appearance and quality of a booklet (for example, see Patent Document 1).

JP 2000-198613 A

  Incidentally, the conventional sheet post-processing apparatus including the sheet cutting method and the cutting apparatus described in Patent Document 1 has the following problems to be solved.

  One is when a sheet bundle is sent to a stapler which is a staple binding device, a planned portion is stapled (staple), then sent to a downstream conveyance path, and the sheet bundle passes through a curved portion of the conveyance path. It may be bent forcibly. The bent sheet bundle is bent due to a difference in circumference between the inside and outside of the bent sheet bundle. When the sheet bundle in the bent state is sandwiched between the belt member or roller member nip and conveyed with rotational frictional force, the staple binding hole of the staple processing unit is forcibly expanded and the vicinity of the staple binding hole is broken, or There is a problem that wrinkles occur and the appearance and quality deteriorate.

  One is that if a position apart from the staple (needle) binding portion of the sheet bundle is sandwiched in the nip by a belt member or a roller member and conveyed to the skew correction position, the positioning of the sheet bundle becomes inaccurate. As a result, the quality of trimming that cuts and aligns the leading edge of the sheet bundle is deteriorated.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a sheet post-processing apparatus that can improve the appearance and quality after trimming by trimming the staple (needle) binding portion of the sheet bundle and the front edge of the bundle.

  In order to achieve the above object, a typical sheet post-processing apparatus of the present invention includes a skew correction conveying member that conveys a sheet bundle in which a plurality of sheets are bound, and is conveyed by the skew correction conveying member. A skew correction mechanism having a regulating member that corrects skew of the sheet bundle when the end of the sheet bundle hits, and a conveyance path provided on at least one of the upstream side or the downstream side of the skew correction mechanism. A sheet bundle conveying member that conveys the sheet bundle that is arranged and skew-corrected, and the skew correction conveying member is arranged so as to match the position of the binding portion of the sheet bundle, and the sheet The bundle conveying member is arranged apart from the position of the binding portion of the sheet bundle.

  According to the sheet post-processing apparatus of the present invention, the sheet bundle after the binding process is conveyed by the skew correction conveyance member of the skew correction mechanism, and the sheet bundle is skewed by abutting the leading end of the sheet bundle against the regulating member. Correct. At that time, the skew correction conveying member is conveyed so as to match the position of the sheet bundle binding portion, so that the positioning accuracy of the sheet bundle is improved. If the sheet bundle can be positioned with high accuracy simultaneously with the skew correction, for example, the trimming accuracy for cutting the edge of the front end of the sheet bundle is improved.

  In addition, if there is a curved part in the conveyance path provided on at least one of the upstream side or the downstream side of the skew correction mechanism, the conveyance path is determined by the difference in circumferential length between the inside and outside of the curved part. Bends or bends in the sheet bundle being conveyed. Here, since the sheet bundle conveying member provided in the conveying path is arranged away from the binding portion position of the sheet bundle being conveyed, the sheet bundle conveying member avoids bending and bending portions generated in the sheet bundle. Therefore, the force that pulls the binding portion and the periphery is not applied as long as it does not contact the binding portion. As a result, it is possible to prevent the binding portion from being torn and wrinkled and to obtain a high-quality sheet bundle.

  Hereinafter, preferred embodiments of a sheet post-processing apparatus according to the present invention and an image forming apparatus provided with the sheet post-processing apparatus will be described in detail with reference to the drawings.

  FIG. 1 shows a copier 1000 as a specific example of an image forming apparatus equipped with the sheet post-processing apparatus of this embodiment. Referring to the functional block diagram of FIG. 7, the copying machine 1000 includes a document feeding unit 100, an image reader unit 200, a printer unit 300 as an image forming unit, a folding processing unit 400, a finisher 500, a trimmer unit 600, and saddle stitching. A unit 800 and an inserter 900 are included. However, the folding processing unit 400, the saddle stitch binding unit 800, and the inserter 900 can be retrofitted to the copying machine as options.

  In FIG. 7, a CPU circuit unit 150 has a CPU (central processing unit: not shown). The CPU circuit unit 150 controls the above-described units in an integrated manner based on the control program stored in the ROM 151 and the setting of the operation unit 1. That is, the CPU circuit unit 150 controls the document feeding control unit 101, the image reader control unit 201, the image signal control unit 202, the printer control unit 301, the folding processing control unit 401, the finisher control unit 501, and the external I / F 203, respectively. To do. The document feeding control unit 101 controls the document feeding unit 100. The image reader control unit 201 controls the image reader unit 200. The printer control unit 301 controls the printer unit 300. The folding processing control unit 401 controls the folding processing unit 400. The finisher control unit 501 controls the finisher 500. The trimmer unit 600 controls the saddle stitch binding unit 800 and the inserter 900. The operation unit 1 includes a plurality of keys for setting various functions relating to image formation, a display unit for displaying a setting state, and the like. The operation unit 1 outputs a key signal corresponding to the operation of each key by the user to the CPU circuit unit 150 and displays corresponding information on the display unit based on the operation signal from the CPU circuit unit 150.

  The RAM 152 is used as an area for temporarily storing control data and a work area for operations associated with control. An external I / F 203 is an interface between the copying apparatus 1000 and an external computer 204, develops print data from the computer 204 into a bitmap image, and outputs it to the image signal control unit 202 as image data. Further, an image of a document read by an image sensor (not shown) is output from the image reader control unit 201 to the image signal control unit 202. The printer control unit 301 outputs the image data from the image signal control unit 202 to an exposure control unit (not shown). The configuration and operation of each of the above parts are as follows.

  On the tray 1001 of the document feeding unit 100, the document is placed and set up face up with the document surface on which the image information is recorded facing up when viewed from the user. In this case, the left end of the document is shown. Documents set on the tray 1001 are sent out one by one from the first page, starting from the document binding position in the left direction indicated by the arrow in the figure. The document moves from the left to the right on the platen glass 102 through a curved conveyance path and passes on the scanner unit 104, whereby image information is read. Such a reading method of reading a document while being conveyed is sometimes referred to as “flowing reading”. That is, when the original moves on the platen glass 102, the lamp 103 of the scanner unit 104 irradiates the reading surface of the moving original. Reflected light from the document is guided to the image sensor 109 by mirrors 105, 106, 107 and a lens 108 arranged at a plurality of locations. The document that has been scanned and read in this manner is discharged onto the discharge tray 112.

  In contrast to the reading method based on the original flow reading, so-called “static reading” is also performed in which an original that is stationary on the platen glass 102 is read. In that case, the document fed from the document feeding unit 100 is temporarily stopped on the platen glass 102 to be in a stationary state, and the scanner unit 104 is moved from the left to the right in the figure with respect to the stationary document. By doing so, the image information of the document is read.

  On the other hand, when reading a document without using the document feeding unit 100, the user lifts and opens the document feeding unit 100 that is not used at this time, places the document on the platen glass 102, and presses it from above. . In this state, the scanner unit 104 is moved to read the image information of the document. That is, in this case as well, the document is read statically as described above.

  As described above, the image data of the document read by the image sensor 109 by any of the reading methods is sent to the exposure control unit 110. The exposure control unit 110 outputs a laser beam corresponding to the image signal, and irradiates the photosensitive drum 111 constituting the image carrier while scanning the laser beam with the polygon mirror 110a. An electrostatic latent image corresponding to the scanned laser beam is formed on the photosensitive drum 111. The electrostatic latent image formed on the photosensitive drum 111 is developed by the developing device 113 and visualized as a toner image.

  The toner image is transferred by the transfer unit 116 onto a sheet of recording paper or the like conveyed from any of the cassettes 114 and 115, the manual paper feeding unit 125, and the double-sided conveyance path 124. The sheet onto which the toner image has been transferred is further sent to the fixing unit 177, where the toner image is permanently fixed by heating and pressing. After the fixing process, the sheet that has passed through the fixing unit 177 is once guided to the conveyance path 122 by the flapper 121. When the trailing edge of the sheet passes through the flapper 121, this is detected and the switchback operation is performed. By switching the path of the flapper 121, the sheet is guided to the discharge roller 118 to be conveyed and discharged from the printer unit 300. As described above, the sheet having the surface on which the toner image is formed through a series of procedures is turned downward (face-down) is discharged from the printer unit 300 as reverse paper discharge.

  When the sheets are discharged out of the apparatus in the face-down state, the image forming process can be performed in order from the first page, or when the image forming process is performed using the document feeder 100, the page order can be made uniform. Further, the page order can be made uniform even when image forming processing is performed on image data transmitted from a host device such as a personal computer.

  Although the image forming process on both sides of the sheet will not be described in detail, the sheet is guided straight from the fixing unit 177 toward the discharge roller 118, and the sheet is switched back immediately after the trailing edge of the sheet passes through the flapper 121. In 121, it is guided to the duplex conveyance path.

<Folding section>
Next, the configuration of the folding processing unit 400 will be described with reference to FIGS. 1 and 2.

  The folding processing unit 400 has a conveyance path 131 for introducing the sheet discharged from the printer unit 300 and leading it to the finisher 500 of the next process. On the transport path 131, several pairs of, for example, transport rollers 130 and 133 each having a pair of opposing faces are arranged. A switching flapper 135 is disposed in the vicinity of the conveyance roller 133 and performs a switching operation to guide and guide the sheet conveyed by the conveyance roller 130 to either the folding path 136 or the finisher 500.

  Therefore, when the sheet is folded, the switching flapper 135 is switched to guide the sheet to the folding path 136, and the sheet is guided to the folding path 420. The sheet guided to the folding path 420 is conveyed to a folding roller 421 where it is folded into, for example, a Z shape. On the other hand, when the sheet folding process is not performed, the switching flapper 410 is switched so that the sheet is guided to the finisher 500 and taken in, and the sheet discharged from the printer unit 300 is directly passed through the transport path 131. Send it in.

  The sheet conveyed through the folding path 136 forms a loop by abutting the leading end of the sheet against the stopper 137 and is folded by the folding rollers 140 and 141 with the formed loop. The loop formed by abutting the bent portion against the upper stopper 143 is further folded by the folding rollers 141 and 142 to be folded into a Z shape. The Z-folded sheet is sent to the conveyance path 131 via the conveyance path 145 and discharged toward the finisher 500 disposed on the downstream side by the discharge roller 133.

Finisher
Next, the configuration and operation of the finisher 500 will be described with reference to FIGS. 1 and 2.

  The finisher 500 performs processing to take in the sheets from the printer unit 300 conveyed through the folding processing unit 400 and bundle them together as a single sheet bundle while aligning the plurality of taken-in sheets. In addition, in the finisher 500, for example, the rear end side of the sheet bundle is stapled (staple), and a sort process or a non-sort process is performed.

  As shown in FIG. 2, the finisher 500 has a conveyance path 520 for introducing the sheet conveyed through the folding processing unit 400 into the finisher, and the conveyance path 520 is provided with a plurality of conveyance rollers. A punch unit 530 is disposed in the middle of the conveyance path 520 and operates when necessary to perform a punching (piercing) process at the rear end of the sheet. Further, conveyance rollers 502 to 508 that are paired in order from the entrance side roller 501 toward the downstream side in the sheet conveyance direction are arranged. The punch unit 530 is provided between the transport roller 502 and the transport roller 503. The punch unit 530 operates as necessary, and performs punching processing on the rear end portion of the conveyed sheet.

  Further, a flapper 513 disposed at the end of the transport path 520 switches the path between an upper discharge path 521 and a lower discharge path 522 connected downstream. In the upper discharge path 521, the upper discharge roller 509 guides the sheet to the sample tray 701. On the other hand, the lower discharge path 522 is provided with a pair of transport rollers 510, 511, and 512, respectively. These conveyance rollers 510 to convey the sheet to the processing tray 550 and discharge it. The sheets discharged to the processing tray 550 are accommodated in a bundle while being sequentially aligned, and sorting and stapling are performed according to settings from the operation unit. The processed sheet bundle is selectively discharged to the stack tray 700 and the sample tray 701 by a bundle discharge roller pair 551.

  Here, the stapling process is performed by a stapler 560 which is a staple binding device. The stapler 560 moves in the sheet width direction orthogonal to the sheet conveyance direction, and performs binding processing on an arbitrary portion of the sheet bundle. The stack tray 700 and the sample tray 701 can be moved up and down along the finisher 500. The upper sample tray 701 receives sheets from the upper discharge path 521 and the processing tray 550. The lower stack tray 700 receives sheets from the processing tray 550. As described above, a large number of sheets can be stacked on the stack tray 700 and the sample tray 701, and the stacked sheets are received by the rear end guide 710 extending in the vertical direction at the rear end and aligned.

《Saddle stitch binding unit》
Next, the configuration and operation of the saddle stitch binding unit 800 included in the finisher 500 will be described with reference to FIG.

  The saddle stitch bookbinding unit 800 includes a pair of opposed press rollers 861. The sheet switched to the right by the switching flapper 514 disposed in the middle of the lower paper discharge path 522 passes through the saddle paper discharge path 523 and is sent to the saddle stitch binding unit 800. The sheet is transferred to a pair of opposed saddle inlet side rollers 801, and a carry-in port is selected by a flapper 802 operated by a solenoid according to the size, and is carried into a storage guide 803 of the saddle stitch binding unit 800. The carried-in sheet is conveyed by the sliding roller 804 to a position where the leading end abuts against the movable sheet positioning member 805 and is regulated. The saddle inlet side roller 801 and the sliding roller 804 rotate by obtaining rotational power from the motor M1. Further, a stapler 820 is provided at a position opposite to the storage guide 803 with the storage guide 803 interposed therebetween. The stapler 820 includes a driver 820a that protrudes the binding needle and an anvil 820b that bends the protruding binding needle. The stapler 820 binds the sheet bundle with the binding needle.

  Here, the sheet positioning member 805 can be moved and adjusted to a position corresponding to, for example, the center portion of the sheet, which is bound in the sheet conveyance direction when the sheet is loaded, by the stapler 820. The movement of the sheet positioning member 805 is configured to be variable to a position corresponding to the size of the sheet by receiving rotational power from the motor M2.

  In addition, a pair of opposed folding rollers 810a and 810b are disposed on the downstream side of the stapler 820, and a protruding member 830 is provided at a position facing it. The protruding member 830 is at the home position at a position retracted from the storage guide 803, and protrudes toward the stored sheet bundle under the rotational power of the motor M3, thereby folding the sheet bundle into the folding rollers 810a and 810b. Fold while pushing into the nip between. Thereafter, the protruding member 830 moves backward and returns to the home position.

  Note that a spring member (not shown) is applied between the shafts of the folding rollers 810 to apply a pressure F1 necessary and sufficient to crease the sheet bundle. The creased sheet bundle is discharged to the fold bundle discharge tray 850 by the first fold conveyance rollers 811a and 811b and the second fold conveyance rollers 812a and 812b, which are a pair of opposed folds. Necessary and sufficient pressures F2 and F3 are applied to the first fold conveying roller 811 and the second fold conveying roller 812 to convey or stop the folded sheet bundle. The pair of folding rollers 810, the first folding conveyance roller 811 and the second folding conveyance roller 812 are rotated at a constant speed by one common motor M4 (not shown).

  Further, when a sheet bundle bound by the stapler 820 is folded from the staple binding portion into two folds, the sheet positioning member 805 is lowered by a necessary distance so that the position of the staple binding portion matches the nip position of the folding roller 810. . By the lowering, the sheet bundle is folded into two or the like with the stapled portion as a base point.

  A pair of opposing alignment plates 815 has a surface protruding to the storage guide 803 while rotating around the outer peripheral surfaces of the folding rollers 810a and 810b, and aligns the sheets stored in the storage guide 803. The alignment plate 815 is movable in the direction of sandwiching the sheet by obtaining power from the motor M5, and performs positioning in the width direction of the sheet.

  Further, a crease press unit 860 is provided downstream of the second fold conveying roller pair 812 so as to spatially overlap the fold bundle discharge tray 850. The crease press unit 860 moves in a direction perpendicular to the sheet bundle conveying direction, and nips and moves the fold portion of the sheet bundle by the press roller 861 to reinforce the crease.

《Trimmer unit》
Here, with reference to FIG. 2, a structure and an effect | action of the trimmer unit 600 are demonstrated based on FIGS.

  The trimmer unit 600 includes a first transport unit 610, a second transport unit 620, a cutting unit 630, a third transport unit 640, a fourth transport unit 650, and a paper discharge unit 660 in order from the upstream side. Configured.

  The first transport unit 610 has a lower transport belt 611 only on the lower side in order to receive a sheet bundle from the saddle stitch binding unit 800, and side guides 612 are provided on both sides of the lower transport belt 611. The side guide 612 is a movable type that can move in the width direction of the sheet bundle, and can correct skew during conveyance of the sheet bundle. Conveying claws 613 (see FIG. 2) are arranged on both sides of the lower conveying belt 611. The conveyance claw 613 can move in the sheet bundle conveyance direction, and conveys the sheet bundle while pushing the rear end of the bundle in order to deliver the sheet bundle to the second conveyance unit 620.

  The second transport unit 620, the third transport unit 640, and the fourth transport unit 650 are each composed of a pair of transport belts on the top and bottom or on the left and right, and each of the top and bottom transport belts is rotated by a single motor. Thus, it is configured to be synchronized with the conveyance speed.

  Therefore, the third transport unit 640 and the fourth transport unit 650 are provided with the following mechanisms that are the main points of the present embodiment.

  First, as shown in FIG. 2 and FIG. 3, the third transport unit 640 is provided with a pair of transport belts (skew correction transport members) 645 and 646 that are opposed to each other in the vertical direction, and appear in and out of the transport path. A protruding abutting stopper (regulating member) 641 that can also move in the transport direction is provided. The conveyance belts 645 and 646 and the abutting stopper 641 constitute a “skew correction mechanism” that corrects the skew of the conveyed sheet bundle folded in half from the staple binding portion. That is, as shown in FIG. 3, the end portion of the sheet bundle T conveyed with the staple (needle) S of the staple binding portion as the head is abutted against the abutting stopper 641 with the staples (needles) S on both sides. The conveying belts 645 and 646 convey the sheet bundle to correct the skew of the sheet bundle T. In that case, as shown in FIG. 5, in one conveyance belt 646, a pair of narrow belt bodies 646a and 646b on both sides match the positions of staples (needles) S on both sides so as to contact the sheet bundle T. It is positioned. The abutting stopper 641 is actuated by receiving rotational power from the motor via the cam 642 around the portion indicated by the symbol K in FIG.

  The sheet bundle T is accurately positioned simultaneously with the skew correction by bringing the conveying belts 646a and 646b into contact with the abutting stopper 641 by contact at the position where the conveying belts 646a and 646b are aligned with the staple (needle) S of the sheet bundle T. Is done. If the leading edge of the sheet bundle T positioned with high accuracy is trimmed and trimmed, a sheet bundle T having a good appearance can be created.

  That is, each of the transport paths of the first to third transport units 610, 620, and 640 is formed in a shape extending substantially linearly. In the cutting unit 630 disposed between the conveyance paths, the cutter 633 of the cutter unit 631 is provided in the vertical direction perpendicular to the direction in which the conveyance path extends. The cutter unit 631 has a cutter 633 that receives power from a motor (not shown) and moves up and down perpendicularly to the conveyance path surface, and has a pressing member 632 for the cutter 633. When the cutter unit 631 descends, the pressing member 632 descends in advance with a time difference and presses against the sheet bundle. The holding member 632 is urged downward by a return spring (not shown), and the cutter unit 631 descends while holding the sheet bundle, and the cutter 633 cuts and cuts the edge of the sheet bundle. Trimming nicely as a booklet.

  In addition, the cutter unit 631 includes a cam, and the shutter 625 disposed on the downstream side of the second transport unit 620 is opened and closed in conjunction with the downward movement of the cutter unit 631. Further, a chip box 635 is disposed below the cutter unit 631 and stores sheet bundle chips cut by the cutter unit 631. A paper discharge unit 660 is disposed on the most downstream side, and stacks and accommodates the sheet bundle conveyed from the fourth conveyance unit 650.

  Next, the fourth transport unit 650 includes a paper discharge path that discharges the sheet bundle T that has been skew-corrected by the third transport unit 640 and that has been trimmed by edge cutting. As shown in FIG. 2, the sheet discharge passage is curved in an S shape and is provided in the vertical direction in the drawing. A pair of opposed sheet bundle conveying belts (sheet bundle conveying members) 655 and 656 shown in FIG. 4 are provided along the S-shaped sheet discharge path. The reason why the sheet discharge path and the sheet bundle conveying belts 655 and 656 are arranged in an S shape in the vertical direction from the lower side to the upper side in the drawing is that the user bends at the lower position and takes out the processed sheet bundle. This is so that it can be taken out in a standing posture so as not to be in a posture. In this case, in one sheet bundle conveying belt 655, a pair of narrow belt bodies 655a and 655b on both sides are separated from the staples (needles) S on both sides at a position apart from the sheet bundle T as shown in FIG. It is positioned so that it touches. However, although not shown, it is of course possible to adopt a configuration in which the belt main bodies 655a and 655b are in contact with the sheet bundle T inside the staples (needles) S on both sides.

  As described above, by setting the positional relationship of the belt with respect to the sheet bundle T in the third conveyance unit 640 and the fourth conveyance unit 650, the following effects can be obtained.

  (1) As shown in FIG. 5, the position of the conveyance belt 646 of the third conveyance unit 640 is made to coincide with the position of the binding portion by the staple (needle) S. As a result, the sheet bundle T after the binding process is conveyed by the conveyance belt 646 and the binding portion is brought into contact with the abutting stopper 641 to correct the skew. By reliably abutting the binding portion against the abutting stopper 641, the positioning accuracy is improved simultaneously with the skew correction of the sheet bundle T, and for example, the trimming accuracy for cutting the edge of the front end of the sheet bundle is improved.

  (2) As shown in FIG. 6, while the sheet bundle T that has undergone skew correction and the like is being conveyed in the sheet discharge passage, the sheet bundle conveying belt 655 of the fourth conveying unit 650 is bound by the staple (needle) S of the sheet bundle T. It contacts so that it may be located outside the part. Therefore, when there is a curved portion in the sheet discharge path, the sheet bundle T during sheet conveyance is bent or bent due to the difference in circumference between the inside and outside of the curved portion. Avoids such bending and bending parts and absorbs them, and does not contact the binding part. As a result, it is possible to obtain a high-quality sheet bundle without applying a force that pulls the binding portion and the periphery forcibly and preventing the binding portion from being torn or leaning.

Inserter
The inserter 900 is arranged at the upper part of the finisher 500. This inserter 900 is prepared for feeding a sheet set by the user on the insert trays 901 and 902 to either the sample tray 701, the stack tray 700, or the folded bundle discharge tray 850 without passing through the printer unit 300. ing. The sheet bundles stacked on the insert trays 901 and 902 are separated one by one in order and merged at the finisher path 520 at a required timing.

  The following is a general operation and action along the flow of the sheet bundle in the sheet post-processing apparatus of this embodiment with reference to the functional block diagram of FIG.

  The sheet bundle T reinforced by the press unit 860 is resumed and delivered to the first conveyance unit 610 of the trimmer unit 600. The lower conveyance belt 611 of the first conveyance unit 610 rotates to convey the sheet bundle T. When the sheet bundle T is detected by a position detection sensor (not shown), the conveyance is temporarily stopped. After that, the width direction alignment of the sheet bundle T is performed by the side guides 612 on both sides of the conveyance path, and then the lower conveyance belt 611 pushes the sheet bundle T while pushing the conveyance claw 613 disposed upstream of the first conveyance unit 610. Resume transport. The sheet bundle T passes through the cutting unit 630 from the second conveyance unit 620 and is conveyed to the third conveyance unit 640. In the third transport unit 640, an abutting stopper 641 projects in advance from the transport path and waits at an appropriate position according to the size of the sheet bundle T to be transported. The sheet bundle T comes into contact with the abutting stopper 641 at the binding portion with the staple (needle) S at the head, and the skew is corrected and stopped (see FIG. 3).

  The conveyance belts 645 and 646 of the third conveyance unit 640 are in contact with each other so as to match the position of the binding portion by the staple (needle) S of the sheet bundle T. Accordingly, an excessive tensile force does not act between the binding portions of the sheet bundle T due to the belt conveyance force, and the positioning can be performed with high accuracy at the time of the trimming process without causing any bending. The conveying belts 645 and 646 of the third conveying unit 640 are temporarily stopped, the cutter unit 631 of the cutting unit 630 starts to descend, and the cutter 633 cuts and aligns the rear end of the sheet bundle. The cutter unit 631 once stops near the bottom dead center and then returns to the initial position. Thereafter, the butting stopper 641 in the third transport unit 640 is retracted, and transport in the third transport unit 640 is resumed. The sheet bundle T is transferred to the fourth conveyance unit 650 in the sheet discharge path which is an S-shaped conveyance path on the downstream side of the third conveyance unit 640, and is conveyed to the sheet discharge unit by the sheet bundle conveyance belts 655 and 656. Be transported.

  FIG. 4 illustrates a state in which the sheet bundle T is being conveyed in the fourth conveyance unit 650 in the sheet discharge path curved in an S shape. While the thick sheet bundle T is passing through the S-shaped sheet discharge path, a deflection occurs due to a difference in curvature between the inner and outer sheets of the sheet bundle T due to a difference in circumferential length between the inner side and the outer side of the S-shaped sheet discharge path. Sometimes. If the conveying belt 655 overlaps or is close to the binding portion (see FIG. 6) of the staple (needle) S of the sheet bundle T, an action of pushing and pulling the bending generated in the sheet bundle T is added. May cause tears and wrinkles. In consideration of this, in the trimmer unit 600 of this embodiment, the positions in the width direction of the conveying belts 655 and 656 are arranged away from the staple (needle) S that is the binding portion of the sheet bundle T. As a result, the deflection generated in the sheet bundle T is absorbed between the conveying belts 655 and 656 and the staple (needle) S, and can pass through the bending path without causing tearing. The positions in the width direction of the conveyance belts 655 and 656 may be arranged apart from the inside of a staple (needle) S that is a binding portion of the sheet bundle T.

  The sheet bundle T transported upward by the fourth transport unit 650 is discharged to the paper discharge tray unit 660 and is sequentially stacked. By disposing the paper discharge port on the upper portion by the fourth transport unit 650, the user's ability to take out the sheet bundle T is also improved.

  In addition, although it explained in full detail that the conveyance belt of the 4th conveyance part 650 was arrange | positioned away from the binding part of a sheet bundle, the conveyance belt provided in the 1st conveyance part 610 and the 2nd conveyance part 620 is also the same. It is arranged away from the binding portion of the sheet bundle.

  The preferred embodiment of the sheet post-processing apparatus according to the present invention has been described above, but the present invention is not limited to that embodiment, and other embodiments, application examples, and the like are within the scope of the present invention. Variations and combinations thereof are also possible.

  For example, as a gist member of the present embodiment, conveyance belts (skew correction conveyance members) 645 and 646 are shown in each figure for specific examples of the skew correction conveyance member. The present invention can also be applied to a conveyance roller that conveys T with rotational frictional force.

1 is a diagram showing a copying machine of an example of an image forming apparatus equipped with a sheet post-processing apparatus according to an embodiment of the present invention. The figure which shows the whole sheet | seat post-processing apparatus of this embodiment. FIG. 9 is a perspective view illustrating a positional relationship between a sheet bundle and a conveyance belt in a third conveyance unit of the present embodiment. FIG. 10 is a perspective view illustrating a positional relationship between a sheet bundle and a conveyance belt in a fourth conveyance unit according to the present embodiment. FIG. 9 is a perspective view schematically showing a positional relationship between a sheet bundle and a conveyance belt in a third conveyance unit. The perspective view which shows typically the positional relationship of the sheet bundle and conveyance belt in a 4th conveyance part. FIG. 2 is a functional block diagram showing a control system configuration of a copying machine including a sheet post-processing apparatus according to the present embodiment.

Explanation of symbols

300 Printer unit 400 Folding unit 500 Finisher 600 Trimmer unit
610 1st conveyance part 620 2nd conveyance part 630 Cutting part 640 3rd conveyance part 641 Butting stopper (Regulating member: Skew correction mechanism)
645 Upper conveying belt of third conveying unit (skew correction conveying member: skew regulating mechanism)
646 Lower conveyance belt of the third conveyance unit 650 Fourth conveyance unit 655 One sheet bundle conveyance belt (sheet bundle conveyance member) of the fourth conveyance unit
656 The other sheet bundle conveyance belt (sheet bundle conveyance member) of the fourth conveyance unit
800 Saddle Stitch Binding Unit 820 Stapler S Staple Needle
T sheet bundle

Claims (7)

A regulation that includes a skew correction conveying member that conveys a sheet bundle in which a plurality of sheets are bound, and corrects the skew of the sheet bundle by abutting an end portion of the sheet bundle conveyed by the skew correction conveying member. A skew correction mechanism having a member;
A sheet bundle conveying member that is arranged in a conveyance path provided on at least one of the upstream side and the downstream side of the skew feeding correction mechanism and that feeds the sheet bundle that is skew-corrected;
In a sheet post-processing apparatus comprising:
The skew correction conveying member is disposed so as to coincide with the position of the binding portion of the sheet bundle, and the sheet bundle conveying member is disposed away from the position of the binding portion of the sheet bundle. Processing equipment.   2. The sheet post-processing apparatus according to claim 1, wherein the sheet bundle conveying member is arranged to be spaced outward or inward in the sheet bundle width direction from a position of a binding portion of the sheet bundle.   3. The sheet post-processing apparatus according to claim 1, wherein the conveyance path in which the sheet bundle conveyance member is disposed has a curved portion and is provided in a vertical direction.   Each of the skew correction conveying member and the sheet bundle conveying member is a pair of opposed members, and is a belt member that draws the sheet bundle into a nip formed between the opposed members by a rotational friction force and conveys the sheet bundle. The sheet post-processing apparatus according to any one of claims 1 to 3, wherein the sheet post-processing apparatus is characterized by the following.   Each of the skew correction conveying member and the sheet bundle conveying member is composed of a pair of opposed members, and is a roller member that draws the sheet bundle into a nip formed between the opposed members by a rotational friction force and conveys the sheet bundle. The sheet post-processing apparatus according to any one of claims 1 to 3, wherein the sheet post-processing apparatus is characterized by the following.     The sheet post-processing apparatus according to claim 1, wherein the binding portion of the sheet bundle is bound by a staple. An image forming unit for forming an image on a sheet;
The image forming apparatus according to claim 1, wherein post-processing is performed on a sheet on which an image is formed by the image forming unit.

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