JP2007091432A - Sheet processing device and image forming device with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To hold even a narrow sheet incapable of being held in a conventional device by lifting a rear end drop means for holding an upper face of a passing sheet with an aligning means. <P>SOLUTION: A sheet processing device comprises a processing tray on which delivered sheets are loaded, rear end drop members 171, 172 for dropping the sheets into the processing tray by pushing rear ends of the sheets from an upper part when the sheets are loaded on the processing tray, aligning members 141, 142 for aligning side ends along a delivery direction of the sheets loaded on the processing tray, and tilt parts 171a, 172a for pushing up the rear end drop members 171, 172 in a direction to be separated from the sheets when the aligning members 141, 142 align the side ends of the sheets with the size in a direction intersecting with the delivery direction of the sheets prescribed or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet processing apparatus that aligns a sheet bundle and performs a binding process or the like on the sheet bundle, and an image forming apparatus including the sheet processing apparatus.

  In an image forming apparatus such as a copying machine, a laser beam printer, an ink jet printer, a facsimile, and a composite device that forms an image on a sheet by an image forming unit, the sheets on which the image is formed by the image forming unit are stacked and aligned. Some have a sheet processing apparatus for binding the sheet bundle or making a hole in the sheet bundle.

  Such a sheet processing apparatus includes a processing tray for receiving and stacking sheets one by one and binding them together with a stapler, and an unbound sheet bundle discharged from the processing tray, Alternatively, a stack tray for receiving the bound sheet bundle is provided (see Patent Document 1).

  FIG. 8 is a diagram illustrating a conventional sheet processing apparatus. The sheet processing apparatus 800 includes a downstream discharge roller pair 701, a knurled belt 702, a sheet guide 703, idle rollers 704, a pulling actuator 705, a processing tray 801, a rear end stopper 802, a width aligning member 803, a bundle discharge roller pair 804, A swing guide 805, a pull-in paddle 806, a rear end dropping member 807, a guide 808, a stack tray 810, a shutter 811, a discharge port 812, a link 813, a rotation shaft 814, and the like are included.

  The downstream discharge roller pair 701 includes a lower discharge roller 701a and a discharge roller 701b, and the sheet P from the sort mode path 700 is discharged onto the processing tray 801. A plurality of knurled belts 702 are disposed at appropriate intervals in the axial direction of the lower carry-out roller 701a.

  Further, the knurled belt 702 is formed to have a required diameter by forming a knurling for preventing slip on the entire outer surface, and has elasticity that can be deformed in the radial direction. The knurled belt 702 is sandwiched between a lower carry-out roller 701a and a carry-out roller 701b. Sheet guides 703 are disposed at appropriate positions between the knurled belts 702. The idle roller 704 that freely rotates contacts the inner peripheral lower surface of the knurled belt 702. The idle roller 704 is moved by the traction actuator 705 at the time of operation of the pull-in paddle 806 and at the time of aligning operation of the width aligning member 803, particularly at the start of the aligning operation that is subsequently performed when the pull-in paddle 806 is operated. The rear end stopper 802 is pulled toward the support surface 802a side.

  The processing tray 801 is located below the knurled belt 702 with the downstream side (left side in the drawing) upward and the upstream side (right side in the drawing) positioned downward with respect to the sheet P discharge direction. It is arranged. The rear end stopper 802 is erected on the lower end (right end in the drawing) of the processing tray 801 and receives the upstream end of the sheets stacked on the processing tray 801. A pair of width alignment members 803 are arranged in a direction crossing the sheet discharge direction so as to align the sheet P from both sides in the width direction.

  The bundle discharge roller pair 804 includes a lower bundle discharge roller 804a and an upper bundle discharge roller 804b. The upper bundle discharge roller 804b is provided at the swing end portion of the swing guide 805, and comes into contact with and separates from the lower bundle discharge roller 804a by swinging the swing guide 805 in the vertical direction. The pull-in paddle 806 has a “height” shape, and rotates around an intermediate fulcrum 806 a to pull back the sheet bundle on the processing tray 801.

  The trailing edge dropping member 807 is mounted on a shaft 809 so as to be rotatable in the vicinity of the rotation center of the swing guide 805, and pressurizes the upper part of the passing sheet. The swing guide 805 moves the upper bundle discharge roller 804b up and down. A guide 808 is a guide path that guides the sheet P from the sort mode path 700 to the downstream discharge roller pair 701.

  In the above configuration, when the sheet P of the sort mode path 700 is sent, the upper bundle discharge roller 804b is moved by the lower bundle discharge roller 804a by the swing of the swing guide 805 in accordance with the entry of the sheet P into the guide 808. Away from the top. The sheet P passes between the lower carry-out roller 701a and the carry-out roller 701b, and is discharged onto the processing tray 801 through the sort mode path 700, and is placed on the upper surface of the processing tray 801. The upper bundle discharge roller 804b stands by above until the sheet P is discharged from the downstream discharge roller pair 701 onto the processing tray 801.

  When the sheet P is discharged onto the processing tray 801, the upper bundle discharge roller 804b approaches the lower bundle discharge roller 804a and sandwiches the sheet P with the lower bundle discharge roller 804a. The bundle discharge roller 804a rotates in the direction of arrow A, slides the sandwiched sheet P onto the processing tray 801, and causes the leading end of the sheet P to approach (retract) the trailing end stopper 802. When the sheet P approaches the trailing end stopper 802, the upper bundle discharge roller 804b is separated from the sheet P (lower bundle discharge roller 804a) and swings upward together with the swing guide 805.

  The sheet P that has been pulled back to the upstream side on the processing tray 801 continues to be pulled back by the contact of the pull-in paddle 806 that has started rotating, and is also width-aligned by the width aligning member 803. Further, when the knurled belt 702 rotates in contact with the arrow B direction, a pulling force is applied to the sheet P at the upstream end. As a result, the sheet P is pressed against the trailing end stopper 802 and aligned.

  At this time, the knurled belt 702 is pulled by the idler roller 704 driven by the pulling actuator 705 to the downstream side (right side in the drawing) from the seat guide 703 and deforms to extend as shown by the broken line, and the rear end stopper 802 It will be in the state which does not obstruct the butting of the sheet | seat P to.

  The above operations are repeated, and the sheets P are stacked on the processing tray 801 in a bundle shape. After the sheet bundle aligned on the processing tray 801 is bound by a stapler (not shown), the upper bundle discharge roller 804b approaches the lower bundle discharge roller 804a. The sheet bundle is sandwiched between the lower bundle discharge roller 804a and the upper bundle discharge roller 804b, and the lower bundle discharge roller 804a rotates in the direction opposite to the arrow A to be discharged onto the stack tray 810.

  Note that in the case of a sheet processing apparatus having a configuration in which a plurality of stack trays 810 are installed, the stack tray 810 moves up and down due to designation of a discharge destination by the user, full stack trays, and the like. In this elevation, when the stack tray 810 passes through the discharge port 812, the downstream discharge roller pair 701 is driven to rotate in the direction opposite to the sheet discharge direction, and the link 813 moves upward with the rotation shaft 814 as a fulcrum. By rotating, the shutter 811 ascends and closes the discharge port 812, thereby preventing the backflow of the sheets P (or sheet bundle) stacked on the stack tray 810 to the discharge port 812.

  By the way, in the conventional sheet processing apparatus described above, when the sheet P is sent from the sort mode path 700 and discharged from the downstream discharge roller pair 701 to the stack tray 810, if the sheet P is a small size, the downstream discharge roller pair 701. May cause the leading end of the sheet P to be folded. This concern will be described with reference to the drawings.

  FIG. 9 is a view showing a peripheral configuration of the downstream discharge roller pair 701 and the rear end dropping member 807. The trailing edge dropping member 807 and the downstream discharge roller pair 701 are arranged in the front and rear (left and right in FIG. 8) at a predetermined interval, and the pair of trailing edge dropping members 807 are slightly narrower than the width of the sheet P. And supported by a shaft 809. Similarly, the pair of downstream discharge rollers 701 is also pivotally supported on the shaft 815 at an interval slightly narrower than the width of the sheet P.

  FIG. 10 is a diagram showing an arrangement relationship between the trailing edge dropping member 807 and the width alignment member 803. The sheet P descends along the lower surface of the trailing edge dropping member 807, and is carried onto the processing tray 801 while the width alignment member 803 restricts the width direction.

  However, as shown in FIG. 9, the pressure applied to the upper surface of the sheet P nipped by the pair of downstream discharge rollers 701 is applied to both end portions of the sheet by the trailing edge dropping member 807, so that the leading edge of the sheet P Hangs down on the processing tray 801, and if conveyed in that state, the leading edge of the sheet P may be folded as shown in FIG.

  As a countermeasure against such a phenomenon, the width aligning member 803 is made to stand by at a position inside the sheet width (sheet discharge area) from the width of the discharged sheet P, and the discharged sheet P is guided by the upper portion of the width aligning member 803. In addition, a technique is known in which the sheet is conveyed to the downstream discharge roller pair 701 without hanging on the processing tray 801 (see Patent Document 2).

JP 2002-265117 A JP 11-322162 A

  However, in the conventional sheet processing apparatus and image forming apparatus, if the countermeasure disclosed in Patent Document 2 is applied to the sheet processing apparatus 800 having the configuration shown in FIG. 8 for a small size sheet, the width alignment member 803 is moved inward. When this is done, the width alignment member 803 interferes with the trailing edge dropping member 807, so that the width alignment member 803 cannot be kept on the inner side of the width of the sheet P. That is, the width aligning member 803 needs a certain height in order to align a plurality of sheet bundles and align the curled sheets. Further, in order for the trailing edge dropping member 807 to play the intended role, it is desirable that the trailing edge dropping member 807 hangs down in a direction to close the guide 808 that is the sheet conveyance path. Thus, the width alignment member 803 and the trailing edge dropping member 807 are in an arrangement relationship that inevitably interferes.

  Note that the above phenomenon can be avoided if the trailing edge dropping member 807 can be disposed inside the width alignment member 803. However, the trailing edge dropping member 807 could not be disposed inside due to interference with the downstream discharge roller pair 701. Even if the rear end dropping member 807 can be arranged on the inner side, the rear end dropping member 807 cannot perform its original role.

  The present invention provides a sheet processing apparatus in which a trailing edge dropping unit that suppresses an upper surface of a passing sheet is lifted by an alignment unit so that even a narrow sheet that cannot be pressed conventionally can be pressed. It is intended to provide.

  The present invention provides an image forming apparatus that includes a sheet processing apparatus that can press down even a narrow sheet that could not be pressed in the past, and has improved sheet image forming efficiency. It is an object.

  In order to achieve the above object, a sheet processing apparatus of the present invention includes a sheet stacking unit on which discharged sheets are stacked, and the rear end of the sheet is pushed from above when the sheet is stacked on the sheet stacking unit. A trailing edge dropping means for dropping into the sheet stacking means, an alignment means for aligning side edges along the discharge direction of the sheets stacked on the sheet stacking means, and the alignment means intersecting the discharge direction of the sheets And a push-up means that pushes up the trailing edge dropping means in a direction away from the sheet when aligning the side edges of the sheets having a size in a direction to be smaller than a predetermined size.

  In the sheet processing apparatus of the present invention, the trailing edge dropping means is pivotally supported so as to extend downstream in the sheet discharging direction, and disposed at a predetermined interval in a direction intersecting the sheet discharging direction. It is characterized by having a pair of rear end dropping members.

  In the sheet processing apparatus of the present invention, the aligning means has a pair of aligning members that can contact and separate from the side edges of the sheet.

  In the sheet processing apparatus of the present invention, the aligning means is a pair of aligning members that can come into contact with and separate from the side edges of the sheet and are disposed to face the outside of the pair of trailing edge dropping members. And the push-up means is capable of abutting an inclined portion provided on one of the opposing surfaces of the rear end dropping member and the alignment member and an abutting portion provided on the other. The trailing edge dropping member is pushed up by the inclination of the inclined portion.

  In order to achieve the above object, an image forming apparatus according to the present invention includes: an image forming unit that forms an image on a sheet; and a sheet processing device that processes a sheet on which an image is formed by the image forming unit. The processing apparatus is the sheet processing apparatus described above.

  The sheet processing apparatus of the present invention can accurately discharge a narrow sheet by lifting the trailing edge dropping unit that pressurizes the upper surface of the passing sheet by the width aligning unit. Therefore, the sheet processing apparatus of the present invention can reliably align the sheet bundle and can reliably process the sheet bundle, so that the appearance of the sheet bundle can be improved.

  The image forming apparatus of the present invention includes a sheet processing apparatus that lifts a trailing edge dropping unit that pressurizes the upper surface of a passing sheet by a width matching unit. Therefore, the image forming apparatus according to the present invention can reliably process the sheet bundle, so that the appearance of the sheet bundle can be improved.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of a sheet processing apparatus according to an embodiment of the present invention and a copier as an example of an image forming apparatus including the sheet processing apparatus in the apparatus main body. Since the image forming apparatus includes a copying machine, a printer, a facsimile, and a complex machine of these, the image forming apparatus of the present invention is not limited to the copying machine. Further, the sheet processing apparatus is not necessarily provided only in the apparatus main body of the copying machine, but may be provided in an apparatus main body such as a printer, a facsimile machine, and a multifunction peripheral. Further, the apparatus main body and the sheet processing apparatus of the image forming apparatus are separate, but may be integrated.

  In FIG. 1, a copier 300 includes a copier body 300 </ b> A and a sheet processing apparatus 1. Since the internal structure of the copying machine main body 300A is a known structure, a detailed description thereof will be omitted. The copying machine main body 300A includes a platen glass 906 serving as a document placement table, for example, an image forming unit 300B that forms an image by an electrophotographic method, a control device 400 that controls the entire copying machine 300, and a document supplied on the platen glass 906. An automatic document feeder 500 for feeding is provided.

  1 and 2, for example, a finisher 1 that is a sheet processing apparatus includes an entrance roller pair 2 provided at a sheet receiving port 1 a of the finisher 1, a transport roller 3, an entrance path 4, and a buffer roller 5. The second conveying roller pair 6, the discharge roller pair 7, the switching flapper 10, the pressing rollers 12, 13, and 14, the sort path 22, the buffer path 23, the sheet detection sensor 31, the sensor 32, and the bundle stacking A guide 40, a punch unit 50, a staple unit 100 having a stapler 101, a processing tray unit 129 having, for example, a processing tray 130 as sheet stacking means, a swing guide 150, a bundle discharge roller pair 180a, 180b, A knurled belt 190, idle rollers 191 and, for example, a stack tray 20 serving as a paper discharge stacking unit. , And a 201, a shutter 202, outlet 205 Doo like.

  The roller pairs 2 and 3 are first conveying roller pairs that convey the received sheet P. The buffer roller 5 is a relatively large-diameter roller, and the sheet P is sandwiched and conveyed by pressing rollers 12, 13, and 14 that are in pressure contact with the buffer roller 5. The second transport roller pair 6 is a roller installed in the sort path 22. The discharge roller pair 7 is a roller that is disposed in the sort path 22 and discharges the sheet P onto the processing tray 130. The switching flapper 10 switches between the sort path 22 and the buffer path 23 for temporarily storing sheets P.

  The sheet detection sensor 31 is a sensor that detects the passage of the sheet P. The sensor 32 is a sensor that detects the sheet P in the buffer path 23. The bundle stacking guide 40 supports the rear end (rear end with respect to the bundle discharging direction) edge of the sheet bundle stacked on the stack tray 200, and also serves as the exterior of the finisher 1 here. The punch unit 50 punches holes near the rear end of the conveyed sheet.

  The staple unit 100 includes a stapler 101 that performs a staple binding process on a bundle of sheets stacked on the processing tray 130, and the stapler 101 is moved to a binding position by a driving unit (not shown). The processing tray unit 129 includes a processing tray 130 that temporarily stacks sheets P, aligns the stacked sheets P, and performs stapling by the stapler 101 of the staple unit 100.

  On the discharge end side of the staple unit 100, one discharge roller constituting a bundle discharge roller pair, here, a lower discharge roller 180a as a fixed side is disposed. When the swing guide 150 comes to the closed position, the upper discharge roller 180b is pressed against the lower discharge roller 180a and discharges the sheet P on the processing tray 130 onto the stack tray 200. In the non-sort mode, the bundle discharge roller pair 180a and 180b receives the sheet P from the discharge roller pair 7 one by one and discharges the sheet P onto the stack tray 200 one by one. The stack trays 200 and 201 are selected when receiving copy output, printer output, or the like.

  2 and 3 are diagrams showing an endless knurled belt and a belt moving mechanism. FIG. 3 is a diagram illustrating the configuration of the swing guide and the processing tray. The processing tray unit 129 including the processing tray 130 will be described with reference to FIGS. The processing tray unit 129 includes a processing tray 130, a rear end stopper 131, an alignment unit 140 that is an alignment unit, a swing guide 150, a pull-in paddle 160, a bundle discharge roller pair 180, and the above-described discharge roller pair. 7 and the knurled belt 190 that is rotationally driven.

  The processing tray 130 is installed in an inclined state by positioning the downstream side upward and the upstream side downward with respect to the sheet bundle discharge direction. Above the processing tray 130, a plurality of sheet guides 130c, a knurled belt 190, and a rear end stopper 131 are arranged at predetermined intervals in the sheet width direction. In an intermediate portion of the processing tray 130, alignment units 140 described later are disposed at external positions corresponding to the left and right sides of the sheet P. In addition, a swing guide 150 including a pull-in paddle 160 and a bundle discharge roller pair 180, which will be described later, is disposed on the upper part which is also on the downstream side.

  The rear end stopper 131 receives the rear end of the sheet P discharged onto the processing tray 130, and is supported by a pivot pin 131b on the lower surface side of the processing tray 130 so as to be rotatable in the vertical direction. A support surface 131a for receiving the rear end of the sheet P is formed at the moving end portion.

  Here, the knurled belt 190 is formed by forming a knurled anti-slip on the entire outer periphery and molding it to a required diameter, and has flexibility that can be deformed in the rotational direction. The knurled belt 190 is wound around the discharge roller 7a on the lower side, that is, on the processing tray 130 side, between the discharge roller pair 170 so as to be rotatable. An idle roller 191 that freely rotates is in contact with the lower inner peripheral surface of the knurled belt 190. The idle roller 191 is pulled to the rear side (the support surface 131a side of the rear end stopper 131) by the traction actuator 192 at the time of a paddle and alignment operation, which will be described later, particularly at the start of an alignment operation performed following the paddle operation. Then, the knurled belt 190 is deformed by being drawn inside the upper sheet guide 130c. As a result, the knurled belt 190 does not hinder the abutment of the sheet P on the support surface 131a. The traction actuator 192 is controlled by a control device (not shown).

  2 and 3, when the knurled belt 190 is not pulled by the pulling actuator 192, the lower portion of the knurled belt 190 protrudes downward from the sheet guide 130c and can contact the sheet stacking surface 130a of the processing tray 130. Is in a state. The knurled belt 190 and the processing tray 130 are widened for the sake of clarity, but are actually narrow (or in contact).

  Further, when the knurled belt 190 is pulled by the pulling actuator 192, the knurled belt 190 enters the inside of the sheet guide 130c and is deformed to a retracted position indicated by a broken line that does not contact the sheet on the processing tray 130. The sheet P discharged from the discharge roller pair 7 is guided downward by a plurality of sheet guides 130 c by the plurality of sheet guides 130 c due to the weight of the sheet, the rotation of the pull-in paddle 160, and the rotation of the knurled belt 190. Then, it falls onto the sheet stacking surface 130a of the processing tray 130. Then, the sheet P slides on the sheet stacking surface 130 a on the processing tray 130 until it is abutted against the abutting support surface 131 a of the trailing end stopper 131.

  In FIG. 3 showing the configuration of the swing guide and the processing tray, the trailing edge stopper 131 receives the trailing edge of the sheet P on the processing tray 130. The rear end stopper 131 is formed in an L shape and is supported by a pivot pin 131 b on the lower surface side of the processing tray 130. When the trailing edge stopper 131 is swung in a direction approaching the processing tray 130 by a link mechanism and a driving device (not shown), the support surface 131a is opposed to the sheet stacking surface 130a that is the stacking surface of the processing tray 130. It stands up vertically. The support surface 131a receives and supports the rear edge of the sheet P. Further, the rear end stopper 131 is configured to rotate to a position below the processing tray 130 so that the staple unit 100 (see FIG. 1) does not interfere with the staple unit 100 when binding the sheet bundle.

  Next, the swing guide 150 will be described. The swing guide 150 is at the front end of the lower surface corresponding to the downstream side (left side in the figure), and an upper discharge roller 180b that contacts the lower discharge roller 180a of the bundle discharge roller pair 180 is pivotally mounted. The swing guide 150 is pivotally supported by a support shaft 151 at the rear end of the lower surface corresponding to the upstream side (right side in the figure), and is swingably supported by the control drive of the rotary cam 152 by the drive motor M150. It comes to move. In the present embodiment, the closed state in which the upper discharge roller 180b is in contact with the lower discharge roller 180a is the home position of the swing guide 150, and a position sensor (not shown) that detects this is provided. In a normal case, when individual sheets P are discharged onto the processing tray 130, the swing guide 150 is moved to an open state (the upper discharge roller 180b is separated from the lower discharge roller 180a), and the sheet is moved. Each operation of the discharge and the alignment of P and the pull-in paddle operation described later are not hindered.

  Further, when the sheet bundle that has been processed on the processing tray 130 is discharged onto the stack tray 200, the swing guide 150 is in a closed state (a state where the upper discharge roller 180b is in contact with the lower discharge roller 180a). Transition. In the non-sort mode, the swing guide 150 is in a closed state (a state in which the upper discharge roller 180b is in contact with the lower discharge roller 180a), and the bundle discharge roller pair 180a, 180b removes the sheet P from the discharge roller pair. 7 one by one and discharged onto the stack tray 200 one by one. The bundle discharge roller pair 180a, 180b is rotated forward and backward by a drive motor M180.

  Next, the shutter 202 will be described with reference to FIG. The shutter 202 prevents the sheet P or the sheet bundle stacked on the stack tray 200 (or 201) from flowing backward to the discharge port 205 when the stack tray 200 (or 201) passes through the discharge port 205. It is provided for. The shutter 202 allows the user to move the stack tray 200 (or 201) due to designation of a discharge destination by the user and full loading of the stack tray 200 (or 201).

  When the discharge roller pair 7 is rotationally driven in a direction opposite to the sheet discharge direction, the shutter 202 is lifted by rotating the link 203 upward about the rotation shaft 204 as a fulcrum, thereby closing the discharge port 205. It is configured as follows. At this time, the drive control unit 206 that drives the discharge roller pair 7 rotationally drives the discharge roller pair 7 in the direction opposite to the sheet discharge direction to control the rotation of the shutter 202. And the idler roller 191, and is pulled in a required direction by the traction actuator 192 so that the posture does not become unstable. Here, control is performed so as to pull to the right side of FIGS. 2 and 3. Then, after the movement operation of the stack tray (200 or 201) is completed, the idle roller 191 that has been pulled to the right in FIGS. 2 and 3 is returned to a predetermined position. It returns to the position near the surface 130a.

  Next, the pull-in paddle 160 will be described. The pull-in paddle 160 is above the processing tray 130 and fixed to the drive shaft 161, and is driven to rotate counterclockwise in FIG. 3 by an appropriate timing by the drive motor M160. The length of each paddle 160 is set to be slightly longer than the distance to the surface of the processing tray 130, and its home position is an obstacle to discharging the sheet P from the discharge roller pair 7 onto the processing tray 130. It is set at a position (upper position in FIG. 3) that does not become. In this state, when the sheet P is discharged onto the processing tray 130, the pull-in paddle 160 is driven to rotate counterclockwise, thereby causing the trailing edge (upstream end) of the sheet P to be discharged onto the processing tray 130. Edge) is retracted until it abuts against the abutting support surface 131a of the rear end stopper 131, and then stops at the home position detected by a position sensor (not shown).

  FIG. 4 is a diagram illustrating a detailed configuration of the matching unit 140. The matching unit 140 will be described with reference to FIG. The alignment unit 140 includes a pair of alignment members 141 and 142 that are disposed to face each other in the width direction of the processing tray 130. The alignment members 141 and 142 are arranged to face each other independently on the lower portion and the upper portion (corresponding to both end sides of the sheet P) in the drawing on the processing tray 130 surface. The first alignment member 141 on one lower side and the second alignment member 142 on the other upper side are each perpendicular to the surface of the processing tray 130 for pressing and supporting the sheet-side end surface. It has alignment surfaces 141a and 142a and rack gear portions 141b and 142b for supporting the back surface of the seat.

  The rack gear portions 141b and 142b are disposed on the lower surface side through a pair of guide grooves 130b and 130d parallel to the vertical direction (corresponding to the width direction of the sheet P) opened in the processing tray 130 surface. That is, the alignment surfaces 141a and 142a are arranged to face the processing tray 130 on the upper surface side, and the rack gear portions 141b and 142b are assembled on the lower surface side so as to be movable in the alignment direction. The rack gear portions 141b and 142b are engaged with pinion gears 143 and 144 that are driven to rotate in the forward and reverse directions by the respective drive motors M141 and M142. Thereby, the alignment members 141 and 142 are movable in the alignment direction.

  Note that a position sensor (not shown) that detects the respective home positions is arranged for the alignment members 141 and 142, and the alignment member 141 is normally set at the lower end and the alignment member 142 is set at the upper end. Waiting at each home position.

  Next, the flow of the sheet P in the finisher 1 as a sheet processing apparatus will be described.

  First, the non-sort mode will be described. When the user designates the sheet discharge mode setting of the copier 300 as non-sort, as shown in FIG. 1, the entrance roller pair 2, the transport roller pair 3, the buffer roller 5, the second transport roller pair 6, the discharge of the finisher 1 The roller pair 7 and the bundle discharge roller pair 180 are rotationally driven so as to convey the sheet P in the downstream direction of the finisher 1.

  As described above, in the non-sort mode, the swing guide 150 is in a closed state (the roller 180a is in contact with the roller 180a). The bundle discharge roller pair 180a, 180b receives the sheet P from the discharge roller pair 7 one by one, is driven to rotate at a speed suitable for stacking, and is discharged onto the stack tray 200 one by one. At this time, the knurled belt 190 is pulled to the right in FIG. 2 by the pulling actuator 192, and the lower part thereof is separated from the sheet stacking surface 130 a of the processing tray 130.

  Here, discharge of a small size sheet such as A5R or STMT-R will be described. When discharging a small size sheet, as will be described later, the end of the sheet is restrained downward, so that the leading edge of the sheet hangs down to the processing tray 130 and is conveyed in that state by the downstream discharge roller pair 701. When it is done, there is a possibility that it will be folded at the leading edge of the sheet. A configuration for this measure will be described with reference to FIGS.

  5 and 6 are diagrams showing a peripheral configuration of the alignment members 141 and 142. FIG. 5A is a diagram illustrating a state before the alignment members 141 and 142 are moved, and FIG. 5B is a diagram illustrating a state after the alignment member 142 is moved. 6 is a side view of FIG. 5, and FIGS. 6A and 6B correspond to FIGS. 5A and 5B.

  The alignment unit 140 includes a pair (one pair) of alignment members 141 and 142, each of which has L-shaped push-up means, for example, contact pieces 141c and 142c attached thereto. Further, a pair of rear end dropping members 171 and 172 forming rear end dropping portions 170 which are rear end dropping means, for example, facing the alignment members 141 and 142 are arranged in a state of being supported on the shaft 173. ing. The trailing edge dropping members 171 and 172 are provided with, for example, contacted pieces 171a and 172a that are push-up means inclined outward from the center in the sheet discharging direction. The abutted pieces 171a and 172a are formed in a square shape, the lower side is fixed to the side surface of the rear end dropping members 171 and 172, and the upper side is an open end from the side surface of the rear end dropping members 171 and 172. It is separated and inclined with respect to the rear end dropping members 171 and 172.

  As shown in FIGS. 5A to 5B, the alignment members 141 and 142 are slid inward by the motors M141 and M142 (see FIG. 4), so that the contact pieces 141c and 142c are contacted. The pieces 171a and 172a are pushed from the side, and the abutted pieces 171a and 172a are pushed up. By this operation, the downward holding of the discharged sheet P by the trailing edge dropping members 171 and 172 is reduced. Thus, with a simple configuration, the trailing edge drop members 171 and 172 can be moved by the alignment members 141 and 142 in a direction orthogonal to the horizontal movement of the alignment members 141 and 142 (sheet thickness direction). .

  Next, the flow of the sheet P in the staple sort mode will be described. When the user designates the mode of the copying machine 300 as a staple sort, the entrance roller pair 2, the transport roller pair 3, the buffer roller 5, the second transport roller pair 6, the discharge roller pair 7, and the bundle discharge roller pair 180 of the finisher 1 are The sheet P is rotationally driven to convey the sheet P in the downstream direction of the finisher 1. Further, the swing guide 150 is shifted to an open state (a state where the upper discharge roller 180b is separated from the lower discharge roller 180a). Then, the sheet P is discharged onto the sheet stacking surface 130a of the processing tray 130 by the knurled belt 190 and the discharge rollers 7b.

  As shown in FIG. 3, the rear end dropping portion 170 is rotatably mounted at the upper end portion in the vicinity of the rotation center portion of the swing guide 150, and the abutted pieces 171a and 172a swing up and down. The upper surface of the passing sheet P is pressurized. When the sheet P is discharged to the processing tray 130, the sheet P is discharged while lifting the trailing edge dropping portion 170, and the trailing edge portion of the sheet P is suppressed by the trailing edge dropping portion 170. Then, it is discharged onto the processing tray 130.

  The sheet P discharged onto the processing tray 130 starts to return to the rear end stopper 131 side by its own weight. At this time, the sheet P rotates in the same direction as the pull-in force due to the counterclockwise rotation of the pull-in paddle 160 stopped at the home position and the left rotation in the discharge direction of the discharge roller 7a. In response to the retraction force, the return action is promoted. The sheet P stops when the rear end is abutted against the rear end stopper 131. Accordingly, the pull-in paddle 160 stops rotating.

  At this time, when the rear end of the sheet P comes into contact with the rear end stopper 131, the knurled belt 190 is moved directly to the retracted position (right side in FIGS. 2 and 3) by the traction actuator 192. One of the alignment members 141 and 142 reciprocates the sheet in the direction intersecting the conveyance direction and the pull-in direction to the alignment position, and returns to the retracted position when the reciprocation is completed. Then, the knurled belt 190 is moved to the protruding position (left side in FIGS. 2 and 3), and the rear end of the sheet is again pressed against the rear end stopper 131 to maintain the consistency.

  The above operation is repeated until the last sheet of the sheet bundle. Thereafter, the bundle of sheets is bound by the stapler 101, and the sheet bundle is discharged onto the stack tray 200 by the discharge operation of the sheet bundle by the bundle discharge roller pair 180 in a state where the swing guide 150 is closed.

  In the above description, the knurled belt 190 is retreated in synchronization with the alignment of the sheets P for all the sheets P discharged to the processing tray 130 one by one. When the number of sheets P that have been reached reaches a predetermined number, the knurled belt 190 may be retracted. That is, when the sheet stacked on the processing tray 130 is thin and the uppermost sheet and the knurled belt 190 at the protruding position are not in contact with each other, the knurled belt 190 is always used, including the reciprocating movement of alignment. It may be kept in the protruding position.

  5 is provided with inclined contact pieces 171a and 172a on a pair of rear end dropping members 171 and 172. For example, the rear end dropping unit 170 shown in FIG. Like the dropping part 270, for example, the abutting pieces 241c and 242c which are inclined pushing-up means are provided on the matching members 241 and 242 of the matching part 240, which are the matching means, and the paired rear-end dropping members 271 and 272 are pushed up. For example, the contact pieces 271a and 272a may be provided.

  As described above, the finisher 1 according to the present embodiment is configured such that when the knurled belt 190, which is an endless belt capable of elastic deformation, is rotationally driven in a direction opposite to the sheet discharging direction, the discharge roller 7a and the idle roller 191 The knurled belt 190 is controlled to move in the required direction by the traction actuator 192 that pulls the idle roller 191 so that the posture does not become unstable, so that it is a sheet conveying rotating body. Wear of the knurled belt 190 can be suppressed and damage can be prevented. Thereby, the sheet P and the sheet bundle are reliably aligned, it is possible to prevent the binding failure of the sheet P and the sheet bundle, and the appearance of the sheet bundle can be improved.

  Further, the copying machine (image forming apparatus) provided with the finisher 1 according to the present embodiment reduces the occurrence of binding failure of the sheet bundle due to the finisher 1, so that the image-formed sheet P is not wasted. The image forming efficiency of the sheet P can be increased.

1 is an explanatory cross-sectional view schematically showing a schematic configuration of a sheet processing apparatus according to an embodiment of the present invention. It is side surface explanatory drawing which shows a knurled belt and a belt moving mechanism. It is a vertical side view of a swing guide and a processing tray. It is a top view of a processing tray and an alignment member moving mechanism. It is detailed explanatory drawing of this invention. It is detailed explanatory drawing of this invention. It is a front view which shows the periphery structure of the alignment member in other embodiment. FIG. 10 is an explanatory cross-sectional view schematically showing a schematic configuration of a sheet aligning unit in a conventional sheet processing apparatus. It is explanatory drawing of the positional relationship of a rear end dropping member, a discharge roller, and a discharge sheet. It is explanatory drawing which showed the phenomenon which generate | occur | produces with the conventional sheet processing apparatus.

Explanation of symbols

P Sheet 1 Sheet processing device (Finisher)
7 Discharge roller pair 130 Sheet stacking means (processing tray)
140,240 Matching means (matching part)
141, 241 Alignment member 141c Push-up means, contact part (contact piece)
142,242 Alignment member 142c Push-up means, contact portion (contact piece)
170,270 Rear end dropping means (rear end dropping part)
171, 271 Rear end dropping member 171 a Pushing means, inclined part (contacted piece)
172,272 Rear end dropping member 172a Push-up means, inclined part (contacted piece)
241c Push-up means, inclined part (contact piece)
242c Push-up means, inclined part (contact piece)
271a Push-up means, contact portion (contacted piece)
272a Push-up means, contact part (contacted piece)
300 Image forming device (copier)
300A copier body

Claims (5)

A sheet stacking means for stacking discharged sheets;
A trailing edge dropping means for pushing the trailing edge of the sheet from the upper side and dropping it into the sheet stacking means when the sheet is stacked on the sheet stacking means;
Alignment means for aligning side edges along the discharge direction of the sheets stacked on the sheet stacking means;
A push-up means that pushes up the trailing edge dropping means in a direction away from the sheet when the aligning means aligns the side edges of a sheet whose size in the direction intersecting the sheet discharge direction is a predetermined size or less; ,
A sheet processing apparatus comprising:   The pair of trailing edge dropping means is pivotally supported so as to extend downstream in the sheet discharging direction and disposed at a predetermined interval in a direction intersecting the sheet discharging direction. The sheet processing apparatus according to claim 1, further comprising a member.   The sheet processing apparatus according to claim 2, wherein the aligning unit includes a pair of aligning members that can contact and separate from a side edge of the sheet. The aligning means has a pair of aligning members that can be brought into contact with and separated from the side edges of the sheet and are arranged to face the outside of the pair of trailing edge dropping members;
The push-up means is capable of abutting an inclined portion provided on either one of the opposing surfaces of the rear end dropping member and the alignment member, and an abutting portion provided on the other;
The sheet processing apparatus according to claim 1, wherein the trailing edge dropping member is pushed up by the inclination of the inclined portion. An image forming unit for forming an image on a sheet;
A sheet processing apparatus that processes a sheet on which an image is formed by the image forming unit,
The image forming apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus according to claim 1.

Images