JP2007045620A - Sheet postprocessor and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of delivery failure such as buckling and rounding and poor visibility or taking-out performance for a user since the abutting angle of a landing sheet tip becomes large when a hanging quantity of the tip is large, in a sheet processor for binding a book by binding the center by processing a sheet such as in a twofold state. <P>SOLUTION: Stable bundle delivery operation is realized by reducing an abutting angle of both by putting a first carrying means in an inclined shape in the same direction as the hanging direction of the bundle tip for receiving the tip of a bundle delivered from a delivery means. Visibility and taking-out performance of a paper bundle to the user are also improved by upwardly displacing a position of the paper bundle by putting a second carrying means positioned on the downstream side of the first carrying means in an inclined shape of upwardly turning the downstream side in the carrying direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet post-processing apparatus. More specifically, for example, an image-formed sheet sequentially discharged from an image forming apparatus such as a copying machine or a laser beam printer is taken into the apparatus, and a portion near the center of the sheet is taken up. The present invention relates to a sheet processing apparatus that performs saddle stitching and performs saddle stitching by performing sheet processing such as folding in half.

  Conventionally, after aligning a plurality of sheets on which images have been formed in the storage tray and binding the vicinity of the center, the sheets are folded together by inserting the central portion into the nip of the pair of folding rollers. There is a device that performs saddle stitch binding by discharging from a discharge port on a discharge side of a pair of folding rollers to a lower discharge tray with a folded portion at the top.

  As an apparatus of this type, as disclosed in Japanese Patent Application Laid-Open No. 2004-284762, as shown in FIG. 18, first, a plurality of sheets are aligned on the compile tray 31, and then the center in the conveying direction is stapled. Subsequently, after being folded in half by the folding rolls 37 and 38, the paper is discharged to the booklet tray 43 by the transport roll 39. The booklet tray 43 has a horizontal stacking surface, and is provided with a tray belt 432 for moving the stacked booklets in the horizontal direction.

Note that a paper take-out tray 431 is provided at the end portion of the booklet tray 43 with the downstream in the transport direction inclined upward, but the paper take-out tray 431 is not provided with a means for transferring the booklet.
JP 2004-284762 A

  In the above-described conventional apparatus, the folded booklet is conveyed while being dropped downward by its own weight in the discharging process by the conveying roll 39. As described above, since the booklet tray 43 has a horizontal shape, when the amount of sagging at the tip is large, the contact angle at the tip landing becomes large, and discharge defects such as buckling and rounding occur. This problem is particularly noticeable with thin paper having a low sheet rigidity.

  Further, since the booklet tray 43 receives the booklet discharged by the transport roll 39, the position thereof is set to a low position. The paper take-out tray 431 has an upward inclined surface in the downstream in the transport direction. However, since the paper take-out tray 431 has no booklet transfer means, its position cannot be increased. Therefore, the visibility and take-out property are not good for the user.

  In order to solve the above problem, in the present invention, a means for discharging the sheet bundle, a first bundle conveying means for receiving and conveying the discharged sheet bundle located under the discharge means, and the first In the post-processing apparatus having a second bundle conveying means provided on the downstream side of the conveying means and a bundle stacking tray for stacking the sheet bundle conveyed by the second conveying means, the first bundle conveying The means has a sheet bundle conveying surface inclined downward as it goes downstream in the conveying direction, and the second bundle conveying means has a sheet bundle conveying surface inclined upward as it goes downstream in the conveying direction, The first and second bundle conveying means conveys a plurality of discharged sheet bundles in a half-stacked state, thereby stabilizing the behavior at the time of discharging and stacking the stacked sheet bundles This improves the take-out property.

  With the above configuration, the first conveying means is inclined in the same direction as the drooping direction of the leading end of the sheet bundle to be discharged, so the contact angle between the leading end of the sheet bundle and the first conveying means is small, The contact load is also lightened. As a result, it is possible to perform a stable bundle discharge operation without causing problems such as buckling, rounding, and catching even for a sheet bundle having a low sheet rigidity and a large amount of sagging at the front end.

  Further, since the second transport unit is inclined upward in the downstream in the transport direction, the stacked sheet bundle is displaced upward as it is transported. As a result, it is possible to contribute to improving the visibility and take-out property of the sheet bundle for the user.

  Furthermore, since the second conveying means is inclined upward in the conveying direction, the capacity in the height direction between the downstream end in the conveying direction and the floor surface can be increased. As a result, if a paper bundle storage box for storing paper bundles is provided between them, a large amount of paper bundles can be accommodated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The main part of the sheet processing apparatus according to the present invention is shown in FIG.

  FIG. 1 is a sectional view showing the internal structure of a copying apparatus 1000 as an image forming apparatus to which the sheet processing apparatus of the present invention can be applied. The copying apparatus 1000 includes a document feeding unit 100, an image reader unit 200 and a printer unit 300, a folding processing unit 400, a finisher 500, a saddle stitch binding unit 800, an inserter 900, and the like. The folding processing unit 400, the saddle stitch binding unit 800, the inserter 900, and the like can be provided as options.

  Referring to FIG. 1, a document is set on tray 1001 of document feeder 100 in an upright state as viewed from the user and in a face-up state (the surface on which an image is formed is facing upward). It is assumed that the binding position of the document is located at the left end portion of the document. Documents set on the tray 1001 are conveyed by the document feeder 100 one by one from the first page in the left direction (arrow direction in the figure), that is, with the binding position at the leading edge. Further, the original is conveyed from the left direction to the right direction on the platen glass 102 through a curved path, and is then discharged onto the paper discharge tray 112. At this time, the scanner unit 104 is held in a predetermined position, and a document reading process is performed when the document passes through the scanner unit 104 from left to right. The above-described reading method is assumed to be document scanning. When the document passes over the platen glass 102, the document is irradiated by the lamp 103 of the scanner unit 104, and reflected light from the document is guided to the image sensor 109 via the mirrors 105, 106, 107 and the lens 108. .

  It is also possible to perform document reading processing by temporarily stopping the document conveyed by the document feeding unit 100 on the platen glass 102 and moving the scanner unit 104 from left to right in this state. This reading method is referred to as fixed document reading. When reading a document without using the document feeding unit 100, the user lifts the document feeding unit 100 and sets the document on the platen glass 102. In this case, the above-described original fixed reading is performed.

  The document image data read by the image sensor 109 is subjected to predetermined image processing and sent to the exposure control unit 110. The exposure control unit 110 outputs laser light corresponding to the image signal. The laser light is irradiated onto the photosensitive drum 111 while being scanned by 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 together with the photosensitive drum 111 by a developing device 113 that forms an image forming unit, and is visualized as a toner image. On the other hand, the recording paper is conveyed to the transfer unit 116 from any of the cassettes 114 and 115, the manual paper feeding unit 125, and the double-sided conveyance path 124. Then, the visualized toner image is transferred to the recording paper in the transfer unit 116. The recording sheet after the transfer is subjected to a fixing process by a fixing unit 177.

  The recording paper that has passed through the fixing unit 177 is once guided to the path 122 by the flapper 121, and after the trailing edge of the recording paper has passed through the flapper 121, the recording paper is switched back and conveyed to the discharge roller 118 by the flapper 121. Then, the recording paper is discharged from the printer unit 300 by the discharge roller 118. As a result, the surface on which the toner image is formed can be discharged from the printer unit 300 in a downward state (face down). This is called reverse paper discharge.

  As described above, when the image forming process is performed sequentially from the first page by discharging the recording paper face-down as described above, for example, when performing the image forming process using the document feeding unit 100, or from the computer When the image forming process is performed on the image data, the page order can be made uniform.

  When image forming processing is performed on both sides of the sheet, 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. Guide to the duplex transport path.

  Next, the configuration of the folding processing unit 400 and the finisher 500 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 guiding the sheet to the finisher 500 side. On the conveyance path 131, conveyance roller pairs 130 and 133 are provided. The switching flapper 135 provided in the vicinity of the conveyance roller pair 133 is for guiding the sheet conveyed by the conveyance roller pair 130 to the folding path 136 or the finisher 500 side.

  When performing the sheet folding process, the switching flapper 135 is switched to the folding path 136 side, and the sheet is guided to the folding path 420. The sheet guided to the folding path 420 is conveyed to the folding roller 421 and is folded into a Z shape. On the other hand, when the folding process is not performed, the switching flapper 410 is switched to the finisher side 500 and the sheet discharged from the printer unit 300 is directly fed through the conveyance path 131.

  The sheet conveyed through the folding path 136 is folded by the folding rollers 140 and 141 by a loop formed by abutting the leading end against the stopper 137. By further folding the part loop formed by abutting the bent part against the upper stopper 143 by the folding rollers 141 and 142, the sheet is Z-folded. The Z-folded sheet is sent to the conveyance path 131 via the conveyance path 145 and is discharged to the finisher 500 attached downstream by the discharge roller 133. The folding processing operation by the folding processing unit 400 is selectively performed.

  The finisher 500 takes in the sheets from the printer unit 300 conveyed via the folding processing unit 400, aligns the plurality of taken-in sheets, bundles them as one sheet bundle, and staples the rear end side of the sheet bundle. This is for performing sheet processing such as stapling (binding processing), sorting, and non-sorting.

  As shown in FIG. 2, the finisher 500 has a conveyance path 520 for taking the sheet conveyed via the folding processing unit 400 into the apparatus, and the conveyance path 520 includes a pair of entrance rollers 501 to 508 in order. A conveyance roller pair is provided.

  A punch unit 530 is provided between the conveying roller 502 and the conveying roller 503, and the punch unit 530 operates as necessary to perform a punching process at the trailing edge of the conveyed sheet.

  A flapper 513 provided 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 paper discharge path 521, the upper paper discharge roller 509 discharges paper to the upper stack tray 701. On the other hand, the lower paper discharge path 522 is provided with a pair of transport rollers 510, 511, and 512, and discharges paper to the processing tray 550. The sheets discharged to the processing tray 550 are accommodated in a bundle while being sequentially aligned, and are subjected to sorting processing and stapling processing according to settings from the operation unit 1, and then stacked by a bundle discharge roller pair 551. It is selectively discharged to the trays 700 and 701.

  Note that the above-described stapling process is performed by the stapler 560, and the stapler 560 is movable in the width direction and can be stapled at an arbitrary position on the sheet. The stack trays 700 and 701 are configured to be movable in the vertical direction. The upper stack tray 701 is a sheet from the upper discharge path 521 and the processing tray 550, and the lower stack tray 700 is the processing tray 550. You can receive a sheet from. In this manner, a large number of sheets can be stacked on the stack trays 700 and 701, and the stacked sheets are regulated and aligned by the rear end guide 710 extending in the vertical direction at the rear end.

  Next, the configuration of the saddle stitch bookbinding unit 800 will be described.

  The sheet switched to the right by the switching flapper 514 provided 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 bookbinding unit 800. The sheet is transferred to the saddle entrance roller pair 801, the carry-in entrance is selected by a flapper 802 operated by a solenoid according to the size, and is carried into the storage guide 803 of the saddle stitch bookbinding portion 800. The loaded sheet is conveyed by the sliding roller 804 until the leading end comes into contact with the movable sheet positioning member 805. The saddle entrance roller pair 801 and the sliding roller 804 are driven by a motor M1. In addition, a stapler 820 is provided in the middle of the storage guide 803 so as to face the storage guide 803. The stapler 820 is divided into a driver 820a that projects a needle and an anvil 820b that bends the projected needle. The sheet positioning member 805 stops at a position where the center portion in the sheet conveyance direction is the binding position of the stapler 820 when the sheet is carried in. The sheet positioning member 805 is movable under the driving of the motor M2, and changes its position according to the sheet size.

  A pair of folding rollers 810a and 810b are provided on the downstream side of the stapler 820, and a protruding member 830 is provided at a position opposite to the pair of folding rollers 810a and 810b. The protruding member 830 has a position retracted from the storage guide 803 as a home position, and protrudes toward the sheet bundle stored by driving the motor M3, whereby the sheet bundle is brought into the nip of the pair of folding rollers 810a and 810b. Fold while pushing. Thereafter, the protruding member 830 returns to the home position again. Note that a pressure F1 sufficient to crease the bundle is applied between the folding roller pair 810 by a spring (not shown). The creased bundle is discharged to the folded bundle discharge tray 850 via the first fold conveyance roller pair 811a and 811b and the second fold conveyance roller pair 812a and 812b. The first fold conveyance roller pair 811 and the second fold conveyance roller pair 812 are also applied with pressures F2 and F3 sufficient to convey and stop the folded bundle.

  813 is a conveyance guide that connects between the folding roller pair 810 and the first fold conveyance roller pair 811, and 814 is a conveyance guide that connects the first fold conveyance roller pair 811 and the second fold conveyance roller pair 812. The folding roller pair 810, the first folding transport roller pair 811 and the second folding transport roller pair 812 are rotated at a constant speed by the same motor M4 (not shown).

  The folding operation of the sheet bundle bound by the stapler 820 is performed by moving the sheet positioning member 805 from the position at the time of the stapling process so that the staple position of the sheet bundle becomes the nip position of the folding roller pair 810 after the stapling process ends. It is executed after the distance is lowered. Thus, the sheet bundle can be folded at the position where the stapling process has been performed.

  Reference numeral 815 denotes an alignment plate pair that has a surface protruding from the storage guide 803 across the outer peripheral surfaces of the folding roller pairs 810a and 810b, and aligns the sheets stored in the storage guide 803. The alignment plate pair 815 is positioned in the width direction of the sheet by moving in the pinching direction with respect to the sheet under the driving of the motor M5.

  A crease press unit 860 is provided downstream of the second fold conveying roller pair 812 so as to spatially overlap with the fold bundle discharge tray 850. This crease press unit 860 has a press holder 862 that supports a pair of press rollers 861, and reinforces the fold by moving the press holder 862 in the crease direction while the pair of press rollers 861 nips the crease. It is.

  Next, the crease press unit 860 will be described with reference to the drawings. 3 is a perspective view of the crease press unit, FIG. 4 is a front view, FIG. 5 is a view as seen from the arrow A in FIG. 2, and FIG. 6 is a view as seen from the arrow C in FIG. The crease press unit 860 includes a base metal plate 863 incorporating a main part and two slide shafts 864 and 865 and is fixed to the front and rear side plates. The two slide shafts 864 and 865 are arranged side by side in the longitudinal direction of the apparatus, and support the press holder 862 through the slide bearings 874 and 875 fixed to the press holder 862, respectively. The belt 868 is stretched around pulleys 866 and 867 that are rotatably disposed in front of and behind the base metal plate 863, and a part of the belt 868 is fixed to the press holder 862 by a connecting metal plate 869. Further, a belt 870 is hung on the pulley 866, and is connected to a motor M6 attached to the base metal plate 863 via a drive transmission means. Therefore, the press holder 862 can move in the front-rear direction of the apparatus as the motor M6 rotates. The home position of the press holder 862 is the back side of the apparatus, and this position is detected by the home sensor S1 (FIG. 6). When the press holder 862 is at the home position, the bundle can be discharged to the folding tray 840 by the second folding conveying roller pair 812.

  Next, the press holder 862 will be described with reference to the drawings. Note that the sheet guide 871 for the press roller pair 861 is originally attached to the press holder 862, but the sheet guide 871 is removed from the following drawings for ease of explanation. 7 is a perspective view of the press holder 862, FIG. 8 is a front view, FIG. 9 is a view taken along arrow B in FIG. 2, and FIG. 10 is a sectional view taken along line XX in FIG. The press holder 862 has a frame 840 to which the slide bearings 874 and 875 are screwed. The press roller pairs 861a and 861b are fixed to roller shafts 872a and 872b, respectively, and are rotatably supported by press arms 873a and 873b via bearings. The press arms 873a and 873b are supported by swinging shafts 874a and 874b fixed to the frame 840 via bearings. The tension springs 875a and 875b are hung on one end of the press arms 873a and 873b and the frame 840, and the pair of press rollers 861a and 861b are nipped with pressure in a direction approaching each other. However, when a bundle is inserted into the press roller pair, the press arms 873a and 873b rotate about the swing shafts 874a and 874b, and the rollers are separated. The gears 876 and 877 are fixed to one end portions of the roller shafts 872a and 872b at positions where they are out of the frame 840. The frame 840 supports gears 880, 879, and 878 that are in mesh with each other but are rotatably supported. The gear 878 is engaged with the gear 876 and the gear 879 is engaged with the gear 877. The gear 880 meshes with the frame 840 with a gear 881 fixed to a gear shaft 882 supported via a bearing. A gear 883 is fixed to the other end of the gear shaft 881, and when the gear 883 rotates, the press roller pair 861a and 861b are rotated by driving transmitted through the gear train. This rotation direction is the same direction as the nipped sheet.

  Further, the gear 883 extends in parallel with the slide shafts 864 and 865 and meshes with a rack gear 841 fixed to the base metal plate 863. Accordingly, when the motor M6 rotates, the press holder 862 moves while being supported by the slide shafts 864 and 865 as the timing belt 868 moves. During this movement, the gear 883 of the press holder 862 rotates while meshing with the rack gear 841, so that the drive is also transmitted to the press roller pair 861a and 861b. The gear trains are set so that the moving speed of the press holder 862 and the peripheral speeds of the two press roller pairs 861a and 861b are equal.

  When the folding process is performed by the press roller pair 861, the middle folded bundle is held in a stopped state by one or more roller pairs across the center in the conveyance direction of the middle folded bundle regardless of the size to be processed. The That is, in the middle folded bundle, the nip pressure F3 of the second folding conveying roller pair 812 on the front end side, the nip pressure F2 of the first folding conveying roller pair 811 on the rear end side, and the size of the middle folded bundle (conveying direction). Depending on the length, the nip pressure F1 of the pair of folding rollers 810 is also applied at the same time, and even if a rotational moment occurs when the pair of press rollers 861 nips the bundle, the middle folded bundle can be efficiently pressed. Note that a sensor 884 provided on the conveyance guide 814 is provided so that the front end stop position (press front end position) of the middle fold bundle during the crease process is constant regardless of the size. It is controlled using. On the other hand, the rear end position (press rear end position) at the time of crease processing is determined so that the two rear ends are regulated by the storage guide 803 and the like, and the positions of the respective parts are not taken. . Therefore, the curl in the direction in which the rear ends of the bundle are opened is not applied while the crease processing is performed by the press roller pair 861. Further, the arrangement of each part is determined so that the press rear end position is outside the area of the storage guide 803. Therefore, even when the crease processing is performed by the press roller pair 861, the storage and alignment operations of the next bundle of sheets in the storage guide 803 are enabled. This contributes to an improvement in device productivity.

  In addition, each portion is set such that the press rear end position of the maximum size (conveyance direction length L1) of the middle fold bundle to be creased and the linear distance L2 between the press front end positions are shorter than the intermediate fold bundle transport direction length L1. The arrangement of is decided. That is, the folded bundle conveying guides 813 and 814 have a gently curved shape that does not curl the bundle. Further, the bundle conveyance guides 813 and 814 are arranged so as to be accommodated between the storage guide 803 and the rear end guide 710 including the press holder 862 (FIG. 2). This has the effect of reducing the size in the apparatus transport direction together with the spatial overlapping arrangement of the fold tray 840 and the crease press unit 860 described above. The second fold conveying roller pair 812 that discharges the bundle to the folding bundle tray 840 at the most downstream side of the curved path has a nip angle determined so that the bundle is inclined downward and discharged. This is because even if a large-capacity sheet is stacked on the stack tray 700 and the stack tray 700 is lowered, the discharge operation can be performed without any trouble.

  Next, the configuration of the folding tray 840 will be described with reference to FIG. The folding tray 840 has a continuous first stacking surface 841, second stacking surface 842, and third stacking surface 843, and stacks the middle folded bundle discharged from the second folding transport roller pair 812. The first stacking surface 841 spatially overlaps the crease press unit 860, and the downstream side in the transport direction is inclined downward. This inclination angle is substantially equal to the discharge angle of the second bundle conveying roller pair 812 described above, and the apex of the inclination is raised as much as possible to a height that does not interfere with the operation of the crease press unit 860. Therefore, the amount of fall from the second folding conveying roller pair to the first stacking surface is set short. The second loading surface 842 is bent from the inclined surface of the first loading surface 841, and has an inclination opposite to the first loading surface 841 (the downstream side in the transport direction is inclined upward). The third loading surface 843 is parallel to the second loading surface with a step, and can be expanded and contracted to be stored in the second loading surface. The inclination angle of the first loading surface 841 is preferably about 20 to 25 degrees downward, and the inclination angle of the second loading surface 842 is preferably about 10 to 15 degrees upward.

  Conveyor belts 844 and 845 are provided on the first stacking surface 841 and the second stacking surface for transporting the stacked folded bundles, both of which are hung at one end on a driving pulley 846 near the bent portion. It has been. The other end of the first conveyor belt 844 is hung on an idler pulley 847 and the second conveyor belt 845 is hung on an idler pulley 848 so as to be parallel to the loading surface. The conveyor belt rotates forward and backward in the same direction under the drive of the conveyor motor M7 connected to the shaft of the drive pulley 846.

  On the first stacking surface, a bundle detection sensor 849 capable of detecting a bundle stacked immediately below the operation area of the crease press unit 860 is provided, and the stack position of the middle folded bundle discharged based on the detection signal is provided. Is controlled.

  As described above, the third stacking surface 843 can be stored in the second stacking surface 842. When the third stacking surface 843 is stored (a broken line position), the storage box 850 having a height from the floor surface to the idler pulley 848 is located at that position. By placing (broken line diagram), the stacking capacity of the bundle can be increased.

  Next, the inserter 900 provided in the upper part of the finisher 500 will be described with reference to FIG. The inserter 900 is for inserting a sheet (insert sheet) different from the normal recording paper into the first page, last page, or intermediate page of the recording paper, and an image is formed by the printer unit 300. This is for inserting an insert sheet or a cover sheet between the two sheets.

  The inserter 900 is for feeding sheets set on the insert trays 901 and 902 by the user to any of the sample tray 701, the stack tray 700, and the folded bundle discharge tray 850 without passing through the printer unit 300. The sheet bundles stacked on the insert trays 901 and 902 are sequentially separated one by one and joined to the finisher path 520 at a desired timing.

  FIG. 11 is a block diagram of the copying apparatus 1000. The CPU circuit unit 150 has a CPU (not shown), and according to the control program stored in the ROM 151 and the setting of the operation unit 1, the document feeding control unit 101, the image reader control unit 201, the image signal control unit 202, and the printer It controls the control unit 301, folding processing control unit 401, finisher control unit 501, and external I / F 203. The document feeding control unit 101 is the document feeding unit 100, the image reader control unit 201 is the image reader unit 200, the printer control unit 301 is the printer unit 300, the folding processing control unit 401 is the folding processing unit 400, The finisher control unit 501 controls the finisher 500, the saddle stitch bookbinding 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, and a key signal corresponding to the operation of each key by the user is sent to the CPU circuit unit 150. While outputting, corresponding information is displayed on the display unit based on the 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).

  Next, based on the above configuration, regarding the saddle stitch bookbinding by the saddle stitcher unit 800 of the present invention, the operation of each unit will be described together with the flow of sheets.

  When the user sets the saddle stitching bookbinding mode, sheets that are appropriately impositioned and formed with images are sequentially discharged from the paper discharge roller 118 of the printer unit 300. The sheet passes through the folding unit 400, is transferred to the inlet roller pair 501, passes through the conveyance path 520, and enters the lower discharge path 522. The subsequent sheet is guided to the saddle discharge path 523 by the switching flapper 514 in the middle of the lower discharge path 522. As shown in FIG. 12, the sheet is discharged to the storage guide 803 while being guided by a flapper 802 corresponding to the size of the sheet, and is stopped at a position that matches the sheet size in advance while receiving the conveying force of the sliding roller 804. The sheet is abutted against the sheet positioning member 805 and positioned in the conveyance direction. Subsequently, sandwiching alignment is performed by the alignment plate pair 815 that has been waiting at a position where there is no problem when the sheet is discharged, and positioning in the width direction is also performed. The above sheet storage and alignment operations are performed each time a sheet is discharged. When the alignment of the final sheet as a bundle is completed, the stapler 820 staples the central portion in the conveyance direction of the sheet bundle. As shown in FIG. 13, the staple-bound bundle moves downward (in the direction of arrow D) as the sheet positioning member 805 moves. In the sheet positioning member 805, the central portion of the sheet bundle, that is, the staple binding portion, stops at a position corresponding to the nip of the folding roller pair 810. Next, the protruding member 830 that has been in the standby position starts to move to the nip of the pair of folding rollers 810 (in the direction of arrow E), and the sheet bundle P1 moves while the center of the sheet bundle P1 spreads the pair of folding rollers 810 to enter the nip of the rollers. It is inserted and folded (FIG. 14). At this time, the folding roller pair 810 is rotated in the direction of the arrow by driving the motor M4 together with the first folding conveyance roller pair 811 and the second folding conveyance roller pair 812, and a folded sheet bundle (medium folded bundle). P1 is conveyed through the conveyance guides 813 and 814 with the crease at the top. Then, as shown in FIG. 15, when the crease is conveyed to a position where it is nipped by the press roller pair 861, the motor M4 stops. The stop position control is performed by the sensor 884 detecting the tip of the middle folded bundle P1. At this time, as described above, the middle fold bundle P1 has the second fold conveyance roller pair 812 at the front end, the first fold conveyance roller pair 811 at the rear end side, and the size ( Depending on the length in the conveying direction, the folding roller pair 810 can reliably hold it. The protruding member 830 moves again to the retracted position when the protruding is completed.

  As shown in FIG. 16, prior to the conveyance of the middle folded bundle P1, the press holder 862 waits at a standby position (back side) corresponding to the size (width direction) of the middle folded bundle P. When the stop of the bundle P is completed and the fold of the middle folded bundle P is inserted into the sheet guide 871 (chain line), the front side (in the direction of arrow F) receives the drive of the motor M6 and rotates the press roller pair 861. Start moving to.

  After that, the press roller pair 861 comes into contact with the side surface of the middle folded bundle P1 that is stopped and held, but since the press puller 861 pair itself is rotated by driving on both sides, the rollers on both sides smoothly run up the side surface. The fold can be nipped (FIG. 17). This effect does not change even if the thickness of the middle folded bundle increases, and the bundle can be nipped between the press roller pair 861 without delay in response in synchronization with the movement of the press holder 862. It means no damage such as wrinkles, tears, or roller marks.

  After the press roller pair 862 reciprocates a predetermined number of times, the crease press unit 860 moves to the home position and opens the path in the transport direction of the middle fold bundle P1. Subsequently, as shown in FIG. 19, the middle folded bundle that has been stopped by the motor M <b> 4 starts to be transported again, and is discharged by the second folding transport roller pair 812. The tip of the middle folded bundle P in the discharging process is transferred while drooping due to its own weight, but is smoothly delivered by the first stacking surface 841 that has a short drop amount and is set to be substantially equal to the discharging angle. Therefore, even in the case of thin paper with low rigidity, the bundle leading edge lands on the first stacking surface 841, so that a stable bundle discharging operation is performed without causing problems such as buckling and curling.

  As shown in FIG. 20, the conveyor belts 844 and 845 start rotating in the transport direction at a predetermined timing by the conveyor motor M <b> 7, and transfer the middle folded bundle P <b> 1 discharged to the folded tray 840. Then, when the bundle detection sensor-849 detects the rear end of the middle folded bundle P1, the conveyor motor M7 stops. As described above, since the bundle detection sensor 849 is disposed immediately below the operation area of the fold press unit 860, the rear end of the stopped middle fold bundle P1 is also outside the operation area of the fold press unit 860 (first stacking). Position). In the meantime, the paper discharge and alignment operation for the next bundle P2 is continued, and the next middle fold bundle P2 is similarly subjected to the crease reinforcement processing by the crease press unit 860, but is in the first stacking position. The middle fold bundle P1 does not interfere with the crease reinforcement processing by the press unit 860.

  Then, as shown in FIG. 21, when the crease process of the middle fold bundle P2 is completed and the crease press unit 860 shifts to the home position, the conveyor belts 844 and 845 receive the drive of the conveyor motor M7 and are opposite to the conveying direction. And the middle folded bundle P1 of the first stacking position is moved by a predetermined amount L so as to approach the second folding conveying roller pair 812 (second stacking position).

  Thereafter, the middle fold bundle P2 is discharged from the second fold conveying roller pair 812 again by the motor M4. The front end of the middle folded bundle P2 hangs down by its own weight, but the rear end of the middle folded bundle P1 in the second stacking position is inside the locus, and therefore moves while sliding on the folded bundle P1 (FIG. 22). Further, the fold of the middle fold bundle P1 is sufficiently strengthened by the crease press unit 860, and the rear end is not opened. In this way, by moving the already loaded bundle P1 to the second loading position and performing the discharge operation of the next bundle P2, the next bundle P2 is stably stacked and discharged without any trouble such as catching. A loading operation is performed.

  When the conveyor belts 844 and 845 are activated in the conveying direction during the discharge and the bundle detection sensor 849 detects the rear end of the middle folded bundle P2, the middle folded bundle P2 is stopped at the first stacking position (FIG. 23). ). This operation is repeated until the final bundle, and the desired number of medium-fold bundles P are stacked on the folding tray 840 in a tiled manner.

As the number of stacks increases, the first middle folded bundle P1 runs up the second stacking surface 842 that is inclined downstream in the discharge direction. Since the fold of the middle fold bundle P is conveyed at the head, the rear end of the bundle is hardly opened when the inclined surface is transferred, and stable bundle transfer is possible.
Further, since the middle folded bundle is conveyed upward, the take-out property for the user is improved.

  Furthermore, as described above, when the third stacking surface 843 is stored in the second stacking surface 842 and the storage box 850 at that position is attached, the downstream end of the second stacking surface 842 is in the raised position. The capacity of the storage box 850 can be increased.

Vertical front view of an image forming apparatus to which the present invention is applicable Longitudinal front view of sheet post-processing apparatus according to the present invention Perspective view of press unit Front view of press unit A view of the press unit in the direction of arrow A in FIG. C view of the press unit in Fig. 2 Perspective view of press holder Front view of press holder B arrow view of the press holder in Figure 2 XX sectional view of the press holder in FIG. Block diagram related to control The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. Diagram showing a conventional device The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention. The figure which shows the flow of the sheet | seat of the sheet | seat post-processing apparatus concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 300 Printer part 400 Folding process part 500 Finisher 700,701 Stack tray 800 Saddle stitch bookbinding part 803 Storage guide 805 Sheet positioning member 810 Folding roller pair 811 First folding conveyance roller pair 812 Second folding conveyance roller pair 813, 814 Conveyance guide 820 Stapler 830 Protruding member 850 Folding tray 840 Folding tray 841 First stacking surface 842 Second stacking surface 843 Third stacking surface 860 Crease press unit 861 Press roller pair 862 Press holder

Claims (6)

  A means for discharging the sheet bundle; a first bundle conveying means for receiving and conveying the discharged sheet bundle; and a second provided on the downstream side of the first conveying means. In the post-processing apparatus having a bundle conveying unit and a bundle stacking tray for stacking the sheet bundle conveyed by the second conveying unit, the first bundle conveying unit is inclined downward toward the downstream side in the conveying direction. The second bundle conveying means has a sheet bundle conveying surface inclined upward as it goes downstream in the conveying direction, and the first and second bundle conveying means A post-processing apparatus that conveys a plurality of sheet bundles in a semi-superimposed state.   2. The post-processing device according to claim 1, wherein the sheet bundle is at least one sheet of middle folded bundle, and the folded portion is conveyed to the top.   2. The post-processing device according to claim 1, wherein the sheet bundle is a saddle stitch bundle of at least two sheets and is conveyed with the binding portion at the head.   4. The post-processing apparatus according to claim 1, wherein the first or second bundle conveying unit includes at least one conveying belt. 5. The post-processing apparatus according to claim 1, wherein the stacking tray can be stored, and the bundle stacking capacity of the post-processing apparatus can be increased by storing the stacking tray. An image forming unit that forms an image on paper, and a post-processing device that performs processing on the paper image-formed by the image forming unit,
6. The image forming apparatus according to claim 1, wherein the post-processing apparatus is a post-processing apparatus according to claim 1.

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