JP6579646B2 - Sheet processing device - Google Patents

Description

  The present invention relates to a sheet processing apparatus that performs a folding process on a sheet central portion after a sheet bundle is bound, and relates to an improvement in each processing mechanism of a sheet bundle binding process, a folding process, and a cutting process.

  In Patent Document 1, sheets sent from an image forming apparatus are stacked in a bundle at a processing position (post-processing stage), the center portion is bound, and then folded (folded in two) from the center portion to be stacked. A bookbinding processing apparatus is disclosed, and a trimmer mechanism for cutting the edge of the folded edge of the sheet is disposed in the sheet discharge path.

  The apparatus disclosed in this document forms an image on a sheet with an image forming apparatus and sends it to a post-processing apparatus. After the sheets are aligned and collected in a bundle by the post-processing apparatus, the sheets are folded and bound from the center of the sheet. Finished. And the variation which arises in a sheet edge edge by folding operation is cut and finished with a trimming mechanism. Note that the apparatus disclosed in this document staples the center portion of a sheet bundle and folds the binding position into a crease.

  Patent Document 2 proposes a mechanism (crimp binding mechanism) for performing post-processing of a sheet bundle by deforming a sheet without using a staple, and performing crimp binding processing. At this time, if the folding position of the sheet bundle is crimped and bound, there is a problem that the binding processing unit is peeled off by the folding processing operation after the binding processing. Therefore, this document introduces as a conventional technique that folding processing is performed on the center portion of a sheet bundle and binding processing is performed at a position offset by a predetermined amount from the fold position.

  Further, Patent Document 3 proposes that when the sheet center portion is folded, the binding process of the previous process is bound at a position offset by a predetermined amount in both the left and right directions from the fold position.

JP 2009-292639 A JP 2014-118300 A Japanese Patent Application Laid-Open No. 2014-3268

  As described above, when binding a sheet bundle by folding it in half from the center, it is known to perform a crimping binding process in which the sheet bundle is subjected to pressure deformation to press the sheets together for a needleless binding process. In this case, it has been proposed in Patent Document 2, Patent Document 3, and the like to process the sheet fold position and the binding position to different positions.

  However, when the binding process and the folding process are performed at different positions on the sheet, the crease line is conventionally set at the center of the sheet as disclosed in Patent Document 2, and the position is shifted to either the left or right from this line. The binding position is set. In such a process, the edge of the fore edge that has been subjected to the binding process based on the crease line is finished to an orderly end face without being displaced, and the edge of the opposite edge (the side not subjected to the binding process) is greatly displaced. The positional deviation amount is twice the positional deviation amount obtained by binding the crease line.

  In this way, when one end of the edge of the fore edge is aligned and the other side is greatly displaced, it is necessary to increase the trimming amount at the fore edge (see FIG. 8 of Patent Document 2). At this time, if the binding processing side edge aligned in a relatively aligned state is also displaced and cut by the same amount as the edge, a cutting area occupying the sheet becomes large.

  When the trimming area for trimming finishes becomes large, a bookbinding error that cuts the print processing area beyond the margin area of the sheet and a problem that the margin balance becomes unnatural. At the same time, there is a problem that the processing amount of the cutting waste of the apparatus increases.

  An object of the present invention is to provide a sheet processing apparatus that has a simple processing mechanism and can easily perform a trimming process of a misalignment edge by folding when a sheet bundle is bound and folded in two.

  In the present invention, the sheet center portion refers to a folding center portion for folding a preset sheet in two. Therefore, in order to achieve the above-described problem, the present invention binds the sheet bundle at a binding position that is a predetermined distance away from the center of the sheet by the binding processing means when folding the sheet central portion in two after the sheet bundle is bound, The folding unit is configured to fold the sheet bundle at a folding position displaced by a predetermined amount from the sheet center to the binding position side between the binding position and the sheet center.

  Further, the configuration will be described in detail. A sheet processing apparatus that folds the sheet central portion after the sheet bundle is bound by the sheet processing unit, and includes a processing unit, a binding processing unit disposed in the processing unit, A folding processing unit; and a cutting unit disposed downstream of the folding processing unit.

  The binding processing means binds the sheet bundle at a binding position that is a predetermined distance away from the center of the sheet, and the folding processing means places the sheet bundle between the binding position and the sheet center from the sheet center to the binding position side. The folding process is performed at the folding position where the displacement is fixed.

  The present invention has the following effects. Since the binding position and the folding position are set at different positions in the sheet bundle, the binding mechanism and the folding mechanism can be configured with a simple structure without performing folding processing on the binding position.

  In the present invention, the binding position is set at a position away from the center of the sheet by a predetermined distance, and the folding position is set between the binding position and the center of the sheet and is displaced by a predetermined amount from the center of the sheet. The edge that is displaced from the edge (the binding processing side) where the folded sheet edge edge is not displaced protrudes outward. Therefore, it is possible to trim only by trimming only the edge that is misaligned, or trimming by using a small amount of the edge that is not misaligned as a margin for trimming, minimizing the trim amount of the edge edge of the sheet bundle. Can be trimmed close by.

  Furthermore, according to the present invention, the amount of displacement between the sheet center and the folding position of the sheet bundle is made different depending on the bundle thickness of the sheet bundle. For example, when the bundle thickness is greater than or equal to a predetermined amount, the displacement amount is set larger than when the bundle thickness is less than or equal to the predetermined thickness, so that the edge of the edge of the fore edge after the folding process is not displaced. The end edge is projected outward, and the trimming cutting area can be further reduced.

1 is an explanatory diagram of an overall configuration of an image forming system including a sheet processing apparatus according to the present invention. FIG. 2 is an explanatory diagram of an overall configuration of a sheet processing apparatus (post-processing apparatus) in the image forming system of FIG. 1. FIG. 2 is a conceptual explanatory diagram of a binding process and a folding process in a sheet processing apparatus, where (a) shows the binding position and folding position of the sheet, (b) shows the folded state, and (c) shows the binding position and folding on the sheet plane. Indicates the position. FIG. 3 is an explanatory diagram of one embodiment (first embodiment) of a binding processing mechanism and a folding processing mechanism in the sheet processing apparatus of FIG. 2. Explanatory drawing of the folding process state of the sheet bundle in 1st Embodiment of FIG. Explanatory drawing of the trimming state of the sheet bundle in 1st Embodiment of FIG. It is explanatory drawing of a binding process mechanism, (a) shows the front state of a press binding mechanism, (b) shows the plane state. FIG. 8 is an explanatory diagram of a press binding mechanism different from FIG. 7 in the sheet processing apparatus of FIG. 2. Explanatory drawing of embodiment (2nd Embodiment) different from FIG. 4 of a folding process mechanism. Explanatory drawing of embodiment (3rd Embodiment) different from FIG. 4 of a folding process mechanism. 4A and 4B are explanatory diagrams of a different embodiment (fourth embodiment) of the binding processing mechanism and the folding processing mechanism, in which FIG. 4A shows the binding processing state and FIG. 4B shows the folding processing state. FIG. 2 is an explanatory diagram of a control configuration in the image forming system of FIG. 1. 3 is a flowchart showing a binding processing operation in the sheet processing apparatus of FIG. 2. 3 is a flowchart showing a folding processing operation in the sheet processing apparatus of FIG. 2.

  Hereinafter, the present invention will be described in detail according to the illustrated embodiment. FIG. 1 is an explanatory diagram of the overall configuration of an image forming system provided with a sheet processing apparatus according to the present invention. The image forming system shown in FIG. 1 includes an image forming apparatus A and a post-processing apparatus B. The post-processing apparatus B includes a stacking unit B1 that stacks sheets sent from the image forming apparatus A shown in FIG. 2 in units (groups), a folding processing unit B2 that performs folding processing on the stacked sheet bundle, and a folding unit. A cutting section B3 for trimming the processed sheet bundle is incorporated. Hereinafter, the image forming apparatus A and the post-processing apparatus B will be described in this order.

[Image forming apparatus]
The image forming apparatus A is disposed on the upstream side of the post-processing apparatus B, forms an image on the sheet, and sends the image from the paper discharge port 10 to the downstream post-processing apparatus B. The illustrated image forming apparatus A includes a paper feed unit 2, an image forming unit 3, a paper discharge unit 4, and a data processing unit 8 in the apparatus housing 1.

  The sheet feeding unit 2 includes sheet stackers 2a, 2b, and 2c for forming images, and feeds sheets of a size selected by the operator to the image forming unit 3 on the downstream side one by one. The image forming unit 3 forms an image with the image data designated on the sheet of the size selected and fed from the sheet feeding unit 2. As the image forming mechanism, various image forming mechanisms such as an electrostatic printing mechanism, an ink jet printing mechanism, a transfer ribbon printing mechanism, a thermal printing mechanism, and an offset printing mechanism are illustrated.

  The electrostatic printing mechanism shown in the figure will be described. A latent image is formed on the photosensitive drum 5 by an optical beam (light emitting device) 6, and toner ink is attached by a developing device 7 to form an image on the drum surface. Then, the image is transferred by the charger 9 to the sheet sent from the paper feeding unit 2. The paper discharge unit 4 heats the sheet sent from the charger 9 to fix the image, and transfers the sheet from the paper discharge path 11 to the paper discharge port 10. A duplex path 12 is connected to the sheet discharge port 10, the conveyance direction of the sheet carried out from the sheet discharge port 10 is reversed (switchback conveyance), the sheet is reversed, and the sheet is fed again to the image forming unit 3. Then, after the image is formed on the back side of the sheet, it is carried out from the paper discharge port 10.

  13 is a scanner unit, which includes a platen 14 for setting an original, a reading carriage 15 for scanning the original on the platen and reading an image, and an image for transferring the read image data to the data processing unit 8 of the image forming apparatus A. A processing unit 16 is provided.

In FIG. 17, a feeder unit 17 separates the original sheets set on the paper feed stacker one by one and feeds them to the platen 14, and stores the read original sheets in the paper discharge stacker.

[Post-processing equipment]
As shown in FIG. 2, the post-processing apparatus B may be configured by the apparatus housing 20 and the first and second post-processing units 35 and 40 (one post-processing unit 40 only) disposed in the housing. And a transport path 25 for feeding sheets from the carry-in entrance 21 to the post-processing section 40, and a storage section 50 for storing post-processed sheets.

  A first post-processing unit 35 is arranged on the downstream side of the conveyance path 25 in the sheet conveyance direction, and a second post-processing unit 40 is arranged on the upstream side. In the illustrated apparatus, the conveyance path 25 is in a substantially horizontal direction, the branch conveyance path 26 that guides the sheet to the second post-processing unit is in a substantially vertical direction, and the first post-processing unit 35 is inclined in the direction inclined from the conveyance path 25. It is arranged. The second post-processing unit 40 is disposed below the first post-processing unit 35.

  The first post-processing unit 35 is configured by a post-processing mechanism that stacks sheets fed from the conveyance path 25 on the processing tray 33 and performs binding processing, and stores the processed sheet bundle in the stack tray 36. For this reason, the sheet tray regulating means 32 and the staple binding unit 31 are disposed on the processing tray 33.

  The second post-processing unit 40 is disposed on the downstream side of the branch conveyance path 26 branched from the conveyance path 25, and includes a stacking guide 41 having a sheet support surface 41a, a binding processing device 39, and a folding processing mechanism 43. ing. Further, a paper discharge path 46 is disposed on the downstream side of the second post-processing section 40, and the processed sheet bundle is stored in the magazine tray 50 (folded sheet storage section). In the paper discharge path 46, a trimmer unit 49 (cutting means; the same applies hereinafter) for cutting the edge portion of the folded sheet bundle is disposed.

  As shown in FIG. 2, the conveyance path 25 is configured by a straight path (which may be a curved path) for guiding a sheet from the path carry-in port 21 to the path sheet discharge port 30, and a branch conveyance path at the center of the path. 26 is provided with a route branching portion 25x for guiding the sheet. A path switching member 23 is disposed in the path branching section 25x, and the sheet fed to the carry-in entrance 21 is transferred from the transport path 25 to the first post-processing section 35 and from the branch transport path 26 to the second post-processing section 40. Guide the sheet. For this reason, the path switching member 23 includes a swing guide piece that changes the sheet conveyance direction and a drive source (motor, solenoid, actuator, etc.) connected thereto.

  In addition, a roller pair (first roller pair 22, second roller pair 24, third roller pair 28, fourth roller pair 29) that conveys the sheet is disposed in the conveyance path 25, and a drive motor (not shown) (hereinafter referred to as “conveyance”). A motor)). The carry-in entrance 21 has a carry-in roller 22 (the first roller pair) and a sheet sensor (entrance sensor) Se1, and the paper discharge port 30 has a paper discharge roller 29 (the fourth roller pair) and a sheet sensor (exhaust). A paper sensor Se2 is arranged.

  Each sensor detects the leading edge and the trailing edge of the sheet passing through the path, and controls the conveyance motor based on the detection signal. The illustrated sheet sensor includes a photo sensor. As this sensor, a mechanical limit sensor, an ultrasonic sensor, a magnetic sensor, or the like can be used.

  In the illustrated conveyance path 25, a buffer path 27 for temporarily retaining the sheet sent from the carry-in entrance 21 toward the first post-processing unit 35 is disposed. The sheet sent from the carry-in entrance 21 by the forward / reverse rotation of 28 (the third roller pair) is temporarily retracted and retained in the path 7.

  The first post-processing section 35 is provided with a sheet end regulating means 32 for positioning the sheet on the processing tray 33 and a side aligning means (not shown) for positioning the sheet side. The sheet sent from the transport path 25 is predetermined. Are collected in a bundle. The processing tray 33 is provided with stapling means 31 (staple binding unit) for binding a bundle of sheets. 34 is an elevating roller that guides the sheet sent from the transport path 25 to the processing tray 33, and guides the sheet one by one to the processing tray, and simultaneously stacks the bundle of sheets after the binding processing on the downstream stack tray 36. To guide.

[Second post-processing section]
The detailed configuration of the second post-processing unit 40 (processing unit; the same applies hereinafter) will be described. On the branch conveyance path 26, the sheet sent from the conveyance path 25 is carried out from the path sheet discharge port 26x. The above-described accumulation guide 41 is disposed on the downstream side of the sheet discharge outlet 26x. For this reason, a conveyance roller 26r is disposed at the outlet end of the branch conveyance path 26 and is connected to a drive motor (not shown).

  The stacking guide 41 stacks and stacks the sheets sent from the paper discharge outlet 26x in a bundle. The guide 41 includes a paper guide member having a sheet support surface 41a, a tray member, a paper loading member, and the like. The one shown in the figure is a stacking guide because it is composed of paper guides arranged in a path for conveying sheets (exactly, an extension path of the branch conveyance path 26). Any structure may be used as long as they are stacked on the sheet support surface and accumulated in a bundle.

  The stacking guide 41 is disposed in the apparatus housing 20 at an inclination angle in a direction in which a sheet sent from the sheet discharge outlet 26x falls along the sheet support surface 41a by its own weight (sliding down direction). A binding processing unit 39, a folding processing unit 43, and a sheet end regulating unit 42 are disposed on the sheet support surface 41a.

  The sheet end regulating means 42 is constituted by a stopper member 42 having a stopper surface 42s for locking the leading edge of the sheet supported by the sheet supporting surface 41a. The stopper member 42 is slidably supported by the frame 20f so as to move in position along the sheet support surface 41a.

  A shift mechanism is connected to the stopper member 42. In the illustrated shift mechanism, a shift motor Ms is connected to a pinion 42p that is pivotally supported by a frame 20f, and a rack 42r that meshes with the pinion 42p is formed integrally with the stopper member 42. Therefore, the pinion 42p rotates forward and backward by forward and reverse rotation of the shift motor Ms, and the rack 42r moves in a predetermined direction along the sheet support surface 41a.

  In addition, as a shift mechanism, a pair of pulleys are arranged at positions spaced along the seat support surface 41a, a belt is bridged between the pulleys, and a stopper member 42 that locks the leading end of the seat on the belt. (Pulley and belt moving mechanism). When one of the pulleys is rotated forward and backward by the shift motor Ms, the stopper member 42 can be moved in the same manner as in the rack and pinion mechanism described above.

  The above-described sheet end regulating means (stopper member) 42 is a position that regulates the front end of the sheet so that the sheet fed to the sheet support surface 41a is positioned at a predetermined binding position, or an arbitrary position different from the binding position. The sheet is locked and accumulated at the position of the sheet, and the position of the sheet bundle is moved to a predetermined binding position after the accumulation is completed, or the position is controlled by any method.

  The binding processing means 39 will be described. The binding processing unit 39 binds the sheet bundle accumulated on the sheet support surface 41a. The binding position Sp on the sheet is set to a position that is a predetermined amount away from the center of the sheet (the center of folding of the two folded sheets; hereinafter referred to as the sheet center Sc).

  The binding processing unit 39 binds the sheet bundle with staples, a press binding apparatus that presses and presses the sheet bundle and performs stapleless binding processing, and binds the sheet bundle with a thread such as resin. It is composed of a yarn binding device to be processed.

"Known technology of staplers"
The structure of the stapler device is disclosed in Japanese Patent Application Laid-Open No. 08-108377, Japanese Patent Application Laid-Open No. 08-108378, Japanese Patent Application Laid-Open No. 2010-254435, Japanese Patent Application Laid-Open No. 2010-150002, and the like. The structure will be explained. A cartridge containing a belt-like staple (blank), a feeding mechanism for feeding out the sheet, a bending block for bending the fed-out linear staple, and a staple inserted into the sheet bundle. A drive plate is provided in the staple head. An anvil unit that bends the staple tip of the staple needle is provided at a position facing the staple head.

  The staple head and the anvil unit are arranged on the apparatus frame so as to be movable in the sheet width direction, and a shift means is provided in each unit. Both units arranged opposite to each other across the sheet bundle are moved to the same position in the sheet width direction. With such a structure, staple binding processing can be performed at a plurality of locations in the center of the sheet.

The illustrated press binding mechanism 39 will be described below. The press binding mechanism binds a plurality of sheets without using staple needles (metal needles).
The unity method is
(1) The sheet bundle is pressed from the front and back with the concavo-convex surface, and the sheets are pressed and deformed to bind.
(2) A sheet of paper to be polymerized by punching a sheet is woven and bound.
(3) The sheet is pierced with a needle-like body to bind a plurality of paper pieces.
For the methods (2) and (3), refer to the patent document described later.

  The bundling structure (1) will be described. FIG. 7 shows that the first and second pressure members 51a and 51b are separated from each other when the sheet bundle is pressure-deformed by a pair of pressure members 51a and 51b facing each other with the sheet bundle interposed therebetween. Then, a mechanism for moving in the sheet width direction is shown.

  The first unit 39A and the second unit 39B are supported by the apparatus frame 20f so as to be movable in the sheet width direction at positions facing each other across the sheet support surface 41a. The first unit 39A is slidably supported by a guide rail 37 (guide rods 37a and 37b) whose unit frame 52 is disposed on the apparatus frame 20f.

  Similarly, the second unit 39B is slidably supported by a guide rail 38 (guide rods 38a and 38b) whose unit frame 53 is disposed on the apparatus frame 20f. Each of the guide rails 37 and 38 is composed of one rail member or a plurality of rail members arranged in parallel to each other in a direction orthogonal to the sheet conveying direction (the fold direction of the folded sheet).

  The first unit 39A is provided with a concavo-convex pressure surface (first pressure surface) 54a and a concavo-convex pressure surface (second pressure surface) 54b meshing with the first unit 39A. At least one of the first pressure surface 54a and the second pressure surface 54b is attached to the unit frame 52 (53) so as to be movable in a direction in which the sheet edge approaches the pressure surface.

  Hereinafter, the case where the 2nd pressurization surface 54b is comprised so that a movement to the direction which approaches and separates with respect to the 1st pressurization surface 54a is demonstrated. At this time, the first pressure surface 54a is integrally fixed to the first unit frame 52 (including a case where the first pressure surface 54a is connected by a fixing tool such as a screw or a rivet and a case where the first pressure surface 54a is integrally formed by metal processing or the like).

  A drive motor Mp (referred to as a pressure motor), a speed reduction transmission mechanism 56, a pressure cam mechanism 57, and an operation lever 58 are attached to the second unit frame 53, respectively. The drive motor Mp is mounted on the second unit frame 53 and is constituted by a DC motor, a stepping motor, or the like that can be rotated forward and backward.

  The rotation of the drive shaft (output shaft) of the drive motor Mp is decelerated by a reduction transmission mechanism 56 (reduction gear, reduction belt, etc.), and the drive is transmitted to the rotation shaft 57x of the pressure cam 57. The pressure cam 57 is configured as a cam curve in which the displacement amount of a follower member 59 (the illustrated one is a floating roller) engaged with a peripheral surface, such as an eccentric cam, varies depending on the rotation angle.

  An operating lever 58 is pivotally supported on the second unit frame 53 by a support shaft 58x. A follower member 59 (floating roller) is pivotally supported at the distal end portion of the operating lever 58, and a second pressurizing surface 54b is integrally attached to the proximal end portion. The actuating lever 58 is provided with a biasing spring 60 and biases the second pressurizing surface 54b to a standby position in a state of being separated from the first pressurizing surface 54a. 61 shown in the figure is a locking stopper for positioning the operating lever 58 in the standby posture.

  When the pressure motor Mp is rotated in a predetermined direction in the above configuration, the pressure cam mechanism 57 causes the second pressure surface 54b to move in the direction approaching the first pressure surface 54a from the standby position, and the sheet is moved on both pressure surfaces. Clamp the bundle.

  The transmission mechanism 56 incorporates a torque limiter (not shown) so that substantially the same pressure is applied according to the thickness of the sheet bundle. For example, the torque limiter is configured to rotate the output side shaft with a spring clutch that is tensioned in the driving rotation direction, and to rotate when the load (pressurized load) exceeds a predetermined pressure.

  The first and second units 39A and 39B described above are configured to move to an arbitrary position in the sheet width direction and perform a binding process at a plurality of locations. The position moving mechanism will be described. The first and second units 39A and 39B are supported by guide rods 37 and 38 of the apparatus frame. The first and second units 39A and 39B are provided with a unit moving mechanism such as a rack and pinion mechanism or a pulley and belt mechanism in the direction of the guide rods 37 and 38 (not shown).

  In the rack and pinion mechanism, a drive motor and a transmission pinion are arranged on one side of the unit frame and the apparatus frame, and a rack that meshes with the pinion on the other side. In the pulley and belt mechanism, a pair of pulleys and a hoisting motor are disposed between the unit frame and the apparatus frame at a distance from each other, and the unit is connected to a belt spanned between the pulleys. Each of the drive motors is a stepping motor, such as a stepping motor, which selects a drive motor excellent in angle control, and is provided with a position sensor for detecting the position.

  In addition, a linear motor mechanism, an inch worm drive mechanism, or the like can be adopted as the position moving mechanism. Then, by moving the first and second units 39A, 39B by the same amount in the same direction from the home position, a plurality of locations in the sheet width direction can be bound by a single mechanism.

  Next, an embodiment different from the binding processing mechanism shown in FIG. 7 will be described. The binding processing mechanism 72 shown in FIG. 8 is provided with independent press bind units 62 and 63 on the left and right sides (the left and right sides in the sheet width direction) of the sheet bundle that face each other. By operating the pair of press bind units 62 and 63 simultaneously or before and after, it is possible to bind both sides of the sheet bundle with respect to the crease line direction.

  The illustrated press bind units 62 and 63 have the same structure, and one (62) will be described. A right unit frame 64 and a left unit frame 65 are fixed to both side portions of the seat support surface 41a on the side frame constituting the apparatus frame 20f. Drive motors Mr1 and Mr2 are mounted on the unit frames 64 and 65, respectively, and are composed of DC motors and stepping motors that can be rotated in the forward and reverse directions. A pressure cam 69 is connected to the output shaft via a gear transmission mechanism 66.

  The transmission mechanism 66 includes a torque limiter (not shown), and generates a sliding motion when a constant load torque acts on the rotational output of the motor. The load torque of the torque limiter is set to an optimum value so that a substantially constant pressure is applied according to the bundle thickness of the sheet bundle.

  In the unit frame 64 (65), a first pressure surface 62a and a second pressure surface 62b are disposed at positions facing each other with the sheet support surface 41a interposed therebetween. The first and second pressure surfaces 62a and 62b are formed in an uneven shape that meshes with each other, and one is fixed, and the other is configured to be movable toward and away from the fixed side. The first pressure surface 62 a is fixedly attached to the unit frame 64. The second pressure surface 62 b is attached to an operating lever 67 that is pivotally supported by the unit frame 64.

  The operating lever 67 is supported so as to be swingable about a support shaft 67x, and a second pressure surface 62b is fixed to the base end portion thereof. Further, a cam follower member 68 (floating roller) is attached to the distal end portion and is engaged with the pressure cam 69. The actuating lever 67 is provided with an urging spring for positioning the first and second pressure surfaces 62a, 62b at home positions (standby positions) separated from each other, and a locking stopper (not shown).

  Accordingly, when the drive motor Mr1 is rotated in a predetermined direction, the pressure cam 69 is rotated, and the operating lever 67 is swung by a predetermined angle about the support shaft 67x. By the swinging operation of the operating lever 67, the second pressure surface 62b approaches the first pressure surface 62a and pinches the sheet bundle on the sheet support surface.

  In addition, as a needleless binding processing mechanism, it is disclosed in Japanese Patent Application Laid-Open No. 2010-027117, Japanese Patent Application Laid-Open No. 2013-178638, Japanese Patent Application Laid-Open No. 2013-126905, and the like, and any of the present invention can be adopted.

"Folding mechanism"
A folding processing mechanism that processes a sheet bundle that has been subjected to binding processing will be described.
As a mechanism for folding the sheet bundle in which the sheet center is bound,
(1) A mechanism is adopted in which a fold position of a sheet bundle is inserted by a folding blade into a nip portion of a pair of rollers in pressure contact with each other, and the fold position is set at an operation timing of the folding blade. (First embodiment)
(2) A mechanism is adopted in which a sheet that travels in a separated state is pressed against the roller circumferential surface by a deflecting unit on the outer periphery of a pair of rollers that rotate in pressure contact with each other, and the crease position is set at the timing of sheet pressing by the deflecting unit. To do. (Second Embodiment)
(3) A mechanism that forms a first nip point and a second nip point with a plurality of pairs of rollers that can rotate forward and backward, conveys the sheet to the folding position at the first nip point on the upstream side, and folds the sheet at the second nip point. The crease position is set at the forward / reverse switching timing for reversing the rotation direction of the roller. (Third embodiment)
(4) In a mechanism for folding a sheet bundle at the nip point of a pair of rollers, the folding roll unit is moved relative to the sheet bundle, and the roll nip position is moved to a set sheet fold position (fourth embodiment). Form).

  Next, the folding position (fold line) of the sheet bundle in the present invention will be described. As shown in FIG. 3A, when the sheet is folded in half, the sheet is folded with reference to a half position in the folding direction (left-right direction in FIG. 3). This position is defined as a sheet center part Sc (sheet center Sc). Further, a position where the sheet bundle is bound is defined as “binding position Sp”, and a position where the sheet bundle is folded is defined as “fold position (folding position) Sf”.

  At this time, a folding processing method in which the sheet center Sc, the binding position Sp, and the folding position Sf are set to the same position is known as conventional magazine binding (see Patent Document 1). Further, Patent Document 2 proposes a folding processing method in which a folding position Sf is set at a sheet center Sc and a position offset from the center by a predetermined amount is used as a binding position Sp.

  In the present invention, the “binding position” Sp is set at a position separated from the sheet center Sc by a predetermined offset amount δ, and the “folding position” Sf is set from the sheet center Sc between the sheet sensor Sc and the binding position Sp. It is set at a position separated by a fixed amount γ (hereinafter referred to as a crease offset amount). At this time, geometrically, “0 <γ <δ” is established, and “δ” is set in the central margin area formed on the sheet.

  “Γ” is set according to the cutting amount (Ce) of the fore edge. When “γ” = “Ce”, the edge ends of the sheet bundle can be aligned with a minimum cutting amount. The cutting amount of the sheet is set to the same cut amount, slightly larger than this, or slightly smaller than the crease offset amount “γ”.

  When “γ”> “Ce” is set, the cutting amount of the sheet bundle is set to be small, and waste disposal is easy (because the amount of waste is small). Further, when “γ” <“Ce” is set, the cutting edge of the sheet bundle is surely cut without being left, so that the finishing quality is improved. By setting “γ” ≈ “Ce”, it is easy to dispose of waste and a process with excellent finishing quality can be expected.

  FIG. 3B shows a state of the sheet bundle that is folded after the binding process. The folded sheet and bundle have the following characteristics. The first feature is that a position different from the binding position Sp is folded after folding a position a predetermined amount (δ) away from the sheet center Sc. ), The edges of each sheet are aligned.

  On the other hand, the overlapped sheet is displaced in the other X portion of the sheet fore edge (downward in the drawing) and protrudes outward from the fore edge Y portion. That is, the edge ends of the half (Y part) of the folded sheet bundle are aligned, and the other half (X part) protrudes outward from the aligned edge edge so that the sheet edge is misaligned. A cutting device (trimmer unit) 49, which will be described later, cuts the edge portion (X portion) that protrudes outward and is displaced.

[First Embodiment of Folding Mechanism]
An embodiment of the folding processing mechanism shown in FIG. 2 will be described. FIG. 4 is a sheet bundle binding process state in this embodiment, FIG. 5 is an explanatory view of a folding process state, and FIG. 6 is an explanatory view of a cutting state.

  The second post-processing unit 40 includes a binding processing unit 39 that binds sheets (bundles) stacked on the stacking guide 41, a folding roll unit 44 that folds the sheet bundle from the center, and a folding blade unit 45. It is configured. The folding roll means 44 is composed of a pair of rollers that are in pressure contact with each other, and is connected to a drive motor (not shown) (hereinafter referred to as “folding processing motor”) that is rotatable in the direction of folding the sheet bundle. The folding blade means 45 is composed of a plate member for inserting the fold position (Sf) of the sheet bundle between the nips of the pair of folding rolls, and is connected to the shift motor M1 (see FIG. 4) by a rack-pinion mechanism. Yes.

  The folding roll means 44 is composed of a pair of rollers that come into pressure contact with each other or a pair of rollers that can be pressed and separated from each other, and tightly clamps the sheet bundle when folding the sheet bundle. Further, in the case where the roller pair is configured so as to be able to be pressed and separated, the sheet bundle is pressed when folded, and after the folded, it is separated to prevent the rear end portion of the sheet from being wrinkled and damaged.

  The stacking guide 41 is constituted by a guide member (plate member) that stacks and stores sheets sent from the upstream branch conveyance path 26, and the illustrated stacking guide 41 is arranged in the vertical direction of the apparatus housing 20. A stopper member 42 that locks the leading end of the sheet is disposed at the lower end of the stacking guide 41. The illustrated sheet end regulating means (stopper member) 42 is attached to the apparatus frame so as to be slidable (slider bridging) along the accumulation guide 41, and moves the sheet according to the size.

[Second Embodiment]
As shown in FIG. 9, a folding roller mechanism 76 composed of a pair of folding rollers is arranged in the transport path 25. The first roller 76a, the second roller 76b, and the third roller 76c are disposed so as to be in pressure contact with each other at the intersection of the conveyance path 25 and the branch conveyance path 77.

  A first nip portion (first folding position) Np1 is formed at the pressure contact between the first roller 76a and the second roller 76b to primarily fold the sheet, and the sheet is applied to the pressure contact between the second roller 76b and the third roller 76c. A second nip portion (second folding position) Np2 for secondary folding is formed.

  Further, as shown in FIG. 9, the first roller 76 a is arranged at a position where a part of the outer periphery faces the conveyance path 25, and a pinch roller (floating roller) 78 is pressed against the roller peripheral surface. The first roller 76a and the pinch roller 78 that are in pressure contact with each other constitute a sheet feeding / conveying means of the conveying path 25, whereby the sheet from the carry-in entrance 21 is conveyed downstream.

[Configuration of folding deflection means]
As described above, the folding roller 79 composed of the three rollers (76a, 76b, 76c) is provided with the folding deflection means 79 at the first nip portion Np1. In the illustrated apparatus, the folding deflection means 79 has a function of “inserting the folding position of the sheet into the roller nip portion”. For this reason, the folding deflection means 79 includes a driven roller 79a and is configured to move from a retracted position outside the path to an operating position that is in pressure contact with the circumferential surface of the folding roller. The movement of the driven roller 79a from the standby position to the operating position acts to retract the sheet end portion into the roller nip portion.

  The configuration of the folding deflection means 79 is shown in FIG. The folding deflection means 79 includes a driven roller 79a, a curved guide 79b, and an elevating member 79c. As shown in the figure, the driven roller 79a is rotatably supported by the elevating member 79c, and the curved guide 79b is integrally attached.

  The driven roller 79a is in contact with the peripheral surface of the second roller 76b located on the downstream side in the sheet moving direction of the transport path 25, and the curved guide 79b is in position along the peripheral surface of the first roller 76a located on the upstream side. Has been placed.

  The elevating member 79c is supported by a guide rail (not shown) provided on the apparatus frame and can reciprocate at a predetermined stroke. The lifting member 79c is provided with a rack 80r and meshes with the pinion 80p. A shift motor (not shown) is connected to the pinion 80p, and the elevating member 79c moves from the solid line state to the broken line state by the rotation of the motor.

  In FIG. 9, the pressure contact point of the sheet feeding and conveying means 76a and 78 is P1, the contact point of the driven roller 79a in contact with the peripheral surface of the second roller 76b is P2, and the driven roller 79a is first in contact with the sheet moving on the conveying path 25. When the contact point is P3, the sheet conveyance length LS2 between P1 and P2 (the figure: the length of the broken line) is set longer than the sheet conveyance length between P1 and P3 (LS1) and LS2> LS1.

  As a result, when the sheet fed by the sheet feeding and conveying means 76a and 78 is guided to the first nip portion Np1 by the driven roller 79a, LS2> LS1 is set and V1> V2 is set at the same time. The end portion is not pulled from the pressure contact P1 of the sheet feeding / conveying means 76a, 78. Accordingly, the sheet is guided to the first nip portion Np1 based on the pressure contact P1 at the rear end.

Further, when the stroke from the contact point P3 to the contact point P2 is LS3, the speed is set so that the following equation is established.
(LS2-LS1) / V2≈LS3 / V1 (Formula 1)

  As a result, when the moving speed of the driven roller 79a is slow, the point (contact point) P3 in contact with the sheet is displaced. At the same time, sagging occurs in the sheet between the pressure contact P1 of the pair of paper feeding and conveying rollers 41 and the driven roller 79a. It is possible to prevent the occurrence of folding misalignment, folding folds and the like due to the misalignment of the sheet engaging point and the sagging of the sheet.

[Third Embodiment]
The embodiment shown in FIG. 10 (referred to as the third embodiment) is a modification of the above-described second embodiment. Similar to the second embodiment, a conveyance path 25 that conveys a sheet in the horizontal direction and a branch path 81 are arranged in a direction that intersects the conveyance path. Conveying means (rollers, belts, etc.) for conveying sheets, an accumulating portion (accumulating guide) for accumulating sheets, and a binding processing means 82 for binding the central portion of the accumulated sheets are arranged in the conveying path 25. .

  The binding processing means 82 employs the stapler device, press binder device, or the like described in the first embodiment. Then, the operator inserts the sheet bundle that is aligned at the carry-in port 21. Then, the conveying unit 83 is configured to index the sheet center from a leading end detection sensor (not shown), and to bind the binding position Sp offset by a predetermined amount with respect to the position Sc by the binding processing unit 82.

  In the branch path 81, a path switching member 84, a folding roll mechanism 85, and a paper discharge path (not shown) are arranged. The folding roll mechanism 85 includes a first roller 73, a second roller 74, and a third roller 75. The first nip point Np3 is between the first roller 73 and the second roller 74, the second nip point Np4 is between the second roller 74 and the third roller 75, and the third roller 75 and the first roller 73 are A third nip point Np5 is provided in between.

  The first roller 73 rotates in one direction, and the second and third rollers 74 and 75 are drivingly connected so as to be switchable in the forward and reverse directions, and the peripheral speeds of the respective rollers are set to be the same. A rotation direction switching means (clutch means) is disposed between the second and third rollers 74 and 75 and the drive unit.

"Roller rotation direction control"
The sheet bundle that has been subjected to post-binding processing in the conveyance path 25 with the above-described configuration is sent to the branch path 81. Therefore, the control means 100 (post-processing control CPU, which will be described later), detects the sheet bundle detected by the leading edge detecting means (photo sensor, mechanical sensor, etc.) Se3 and the nip point Np3 of the first and second rollers and the nip of the second and third rollers. The material is conveyed to the state shown in FIG.

  At this time, the first and second rollers 73 and 74 and the second and third rollers 74 and 75 rotate in the same direction (arrow direction) to convey the sheet bundle in the arrow A direction. When the fold position of the sheet bundle reaches the third nip point Np5 from the detection signal at the sheet leading edge, the rotation of the second and third rollers 74 and 75 is stopped, and both rollers are rotated in the opposite directions. Then, the sheet bundle is folded into the state shown in FIG. 10B and carried out to the paper discharge path. The paper discharge path and the mechanism of the trimmer discharged to this path will be described later.

  In such a configuration, the control means 100 uses the signal that detects the leading edge of the sheet bundle as a reference so that the fold position is the sheet length (L) × ½− (δ−γ) position. Guide to 3 nip point Np5. The fold position is set at a position separated from the sheet center by a predetermined amount (offset value γ) between the sheet center (1 / 2L) and the binding position (offset amount δ from the sheet center).

[Fourth Embodiment]
The embodiment shown in FIG. 11 shows a modification of the first embodiment described above, and the folding processing mechanism 43 and the binding processing device 39 are mounted on a unit frame 86 separated from the device frame 20f. The unit frame 86 is supported by a guide rail (not shown) so that the position of the unit frame 86 can be moved, and the unit frame 86 is moved by a driving mechanism such as a pulley & belt mechanism or a rack & pinion mechanism and a driving motor (not shown). Other configurations include the same transport path 25, branch transport path 26, transport roller 26r, and the like as in the first embodiment described above.

  The operation of the above-described embodiment will be described in accordance with the sheet bundle binding processing state of FIG. 11A and the sheet bundle folding processing state of FIG. In the same configuration as in the first embodiment, sheets are fed to the carry-in entrance 21 of the conveyance path 25, and the sheets are stacked and stacked on the sheet support surface 41a. When a predetermined sheet bundle is accumulated on the sheet support surface, the control means (post-processing control CPU) 100 moves the unit frame 86 to a position where the binding position is offset by a predetermined amount (δ) from the sheet center. Set.

  This state is shown in FIG. 11A, and the binding process is performed at this position. Next, the control unit 100 moves the position of the unit frame 86 so that the fold position of the sheet bundle coincides with the nip point of the folding roll unit 44. Then, the folding roll means 44 is rotated, and at the same time, the folding blade 45 is moved from the standby position to the operating position. Since the operation and the specific configuration are the same as those of the first embodiment, description thereof is omitted.

[Configuration of trimmer unit]
The trimmer unit 49 shown in FIG. 6 will be described. A paper discharge path 46 is disposed downstream of the folding processing unit (second post-processing unit) 40, and the folded sheet bundle is stored in a stacker (magazine tray) 50. A trimmer unit 49 is disposed in the paper discharge path 46, and cuts the edge of the folded sheet bundle.

  The trimmer unit 49 includes a cutting blade 47 that cuts the sheet bundle, a paper pressing member 87 that presses and holds the sheet bundle against the paper mounting table 48, and a bundle conveyance unit 88 that conveys the sheet bundle to the cutting position. Yes. The paper table 48 is arranged in the paper discharge path 46 and is rotated and guided in the sheet discharge direction. The cutting blade 47 is supported by the unit frame 90 so as to be movable up and down, and is configured to be moved up and down between a standby position and a cutting position by a lifting mechanism. Although not shown, the elevating mechanism includes a drive cam connected to a drive motor. For example, the cutting blade 47 is provided with a pair of left and right eccentric cams (drive cam; not shown) at a distance, and this cam is connected to a drive motor ( The cutter is driven to rotate.

  The paper pressing member 87 is constituted by a pressurizing mechanism that presses the cutting edge of the sheet bundle cut by the cutting blade 47. For example, a pressure member that moves up and down in conjunction with the movement of the cutting blade 47 that moves up and down is supported by the unit frame 90 so as to be movable up and down. An urging spring 92 that urges the pressing member in the paper pressing direction is disposed between the unit frame 90. Then, the urging spring 92 acts to press the sheet bundle in conjunction with the up and down movement of the cutting blade 47.

  In the paper discharge path 46, a bundle conveying means (paper discharge roller pair 88) for conveying the sheet bundle folded from the folding roll means 44 to the downstream cutting position Cp is disposed. Further, a tip regulating means (not shown) for locking the tip of the sheet bundle is disposed in this path. The illustrated tip regulating means is constituted by a stopper member that is swingably disposed on the apparatus frame 20f. This stopper member is configured to be able to change the position in the paper discharge direction according to the sheet size and the cutting amount of the sheet bundle.

  For example, although not shown, the stopper member is supported by the frame so as to be movable in the paper discharge direction, and is connected to a shift motor (for example, a stepping motor) via an interlocking mechanism such as a pulley & belt mechanism and a rack and pinion mechanism. . Then, at the same time as driving to a position corresponding to the sheet size, it moves according to the cutting amount with reference to that position.

  In the illustrated apparatus, the sheet bundle sent from the folding roll means 44 is positioned on the paper platform 48 in the posture shown in FIG. Specific means will be described later.

[Control configuration]
A control configuration in the image forming system including the sheet processing apparatus B of FIG. 1 will be described. FIG. 12 is a block diagram of the control configuration. The illustrated system includes an image formation control unit 95 and a post-processing control unit 100. The image forming control unit 95 includes a mode selecting unit 96 and an input unit 97, and controls the image forming apparatus A according to the image forming mode set by the operator. At the same time, the post-processing mode set by the mode selection means 96 is transferred to the post-processing control unit 100 as a command.

  A post-processing control unit (CPU; central processing means) 100 includes a stacking operation control unit 101, a binding processing operation control unit 102, a folding processing operation control unit 103, and a paper discharge operation control unit 104. The paper discharge operation control unit 104 is provided with a trimmer control unit 105 and a paper discharge conveyance control unit 106.

  The binding processing operation control unit 102 includes a calculation unit 107 (executed by the CPU) that calculates a sheet center Sc based on a sheet size (information shown from the image formation control unit 95 is illustrated), and a sheet. Binding position setting means 108 (executed by the CPU) is provided for setting a binding position at a distance from the center Sc.

  The binding position setting means 108 (1) reads the offset value δ stored in advance in the RAM 98 in accordance with the sheet size and sets the “binding position Sp”. Alternatively, (2) “binding position Sp” is calculated according to the bundle thickness of the sheet bundle. For example, when the bundle thickness is small, the binding position is calculated at a position close to the sheet center Sc, and when the bundle thickness is thick, it is calculated at a position away from the sheet center Sc. The calculation method will be described later.

  The folding processing operation control unit 103 sets a “folding position Sf” between the sheet center Sc calculated by the CPU 100 and the binding position Sp. The setting is made by (1) a method in which the crease offset amount (displacement value; γ) between the sheet center Sc and the folding position Sf is previously determined and stored in the ROM 99 (in this case, γ <δ (minimum binding). Set the position offset amount). (2) Either the sheet center Sc from the bundle thickness of the sheet bundle or a method of calculating the offset amount of the fold (for example, an operation for setting the offset amount larger than that when the sheet bundle is thick) is adopted.

  Next, the operation procedure of the image forming system in FIG. 1 will be described with reference to FIG. When system operation is started (system power ON), image forming conditions are set (St01). The image forming conditions are specified by the operator from the control panel, such as color, monochrome, reduction ratio, number of copies, and sheet size. At the same time, a processing mode for post-processing the image-formed sheet is set (St02). As the post-processing mode, a printout mode, a jog sorting mode, a staple binding mode, a magazine binding mode, or the like is designated. The present invention relates to a magazine binding mode in which sheets on which images have been formed are collected in a bundle and the sheet center is bound and then folded. This bookbinding mode will be described below.

  When the image forming conditions and the post-processing mode are set, the image forming apparatus A forms the designated image on the designated size sheet (St03). The image-formed sheet is sent from the image forming apparatus A to the sheet post-processing apparatus B, and the post-processing operation is executed in the designated mode (St04).

  When the post-processing operation is the magazine binding mode (St05), the post-processing control unit 100 “sets the binding position Sp” simultaneously with the reception of the mode designation command (St06). The binding position Sp is set by (1) setting sheet size information and a binding position (binding position offset value; δ) in advance for each sheet size, and calling data recorded in the ROM 99 (hereinafter referred to as “case 1”). explain). Alternatively, (2) the binding position offset value (δ) is read from the ROM 99 from the sheet size information and the sheet bundle thickness information, and is corrected according to the sheet bundle thickness (hereinafter described as “Case 2”).

“Case 1 (St07)”
The control means (post-processing CPU) 100 reads offset amount (δ) data set for each sheet size and stored in the ROM 99 from the sheet size information (St08) (St09). At this time, the binding position offset amount δ is preferably set within a margin area (δ <minimum margin area) formed in the center of the sheet. In addition, the amount of misalignment of the edge edge when folded according to the bundle thickness of the sheet is more outward than the folded upper part (FIG. 3 (b) Y part) and the folded lower part (FIG. 3 (b) X part). The length is set so as to protrude (Ce). The offset amount (δ) at this time is preferably determined by experiment, and the bundle thickness (δ when thick)> (δ when thin) is set.

“Case 2 (St10)”
The control means (post-processing CPU) 100 is a case where the sheet bundle adjusts the offset amount (δ) from the sheet center Sc to the binding position according to the bundle thickness. The control unit 100 calls the offset amount reference value (δ) stored in the ROM 99 from the sheet size information (St11) and the sheet bundle thickness (St12) (St13). Then, the offset amount reference value (δ) is corrected by the sheet bundle thickness, and the offset amount (δ) is set to the binding position Sp to be executed (St14).

The correction method is calculated as follows, for example.
The bundle thickness of the sheet bundle is calculated by (1) calculating the number of pages for image formation from the data volume designated by the image forming apparatus A, or (2) or “page total number × average from page information included in the image formation data” Calculated by “sheet thickness”. Alternatively, (3) a sheet sensor (a photo sensor, a limit sensor, a magnetic sensor, an ultrasonic sensor, a mechanical sensor, or the like) that detects a sheet is disposed in the conveyance path. Then, the bundle thickness is determined by “total number of pages × average sheet thickness” counted by the sensor.

Next, the control means 100 corrects the offset reference value (δ) stored in the ROM 99 according to the sheet size and read out with the sheet bundle thickness. This correction formula is calculated as follows, for example.
(Reference value from ROM 99; δ) × (calculated bundle thickness; total number of pages * paper thickness) / reference bundle thickness (standard bundle thickness stored in ROM 99).
In such a calculation method, the offset amount (δ) is set to be large if the bundle thickness of the sheet bundle is thick, and the offset amount (δ) is set to be small if the sheet bundle is thin.

  The offset amount (δ) of the binding position is set by any one of the above case 1 and case 2 or other methods (St15). Based on this offset amount δ, the control means 100 moves the position of the sheet end regulating means 42 (first embodiment of the folding roll means 44). The setting of the binding position Sp will be described later for each of the first to fourth embodiments of the folding roll means 44.

  The control unit 100 sets the position of the sheet end regulating unit 42 according to the sheet size and the binding position offset amount δ, and stops at that position (St16). In this state, the image-formed sheet is sent out from the image forming apparatus A, and the post-processing apparatus B is conveyed and accumulated on the sheet support surface 41a of the post-processing unit 40 (St17).

  Next, when the control unit 100 receives a job end signal from the image forming apparatus A (St18). The binding process is executed (St19). This binding process is performed at a position shifted by a predetermined offset amount (δ) from the sheet center Sc of the sheet bundle (St20).

  Next, the control means 100 moves to the folding process shown in FIG. The control means 100 sets the fold position Sf (St21). This fold position is set by one of the following methods.

“Case 1 (St22)”
The control unit 100 obtains sheet size information (size information transferred from the image forming apparatus A) (St23), and reads the fold position offset value (γ) corresponding to the size (St24). The ROM 99 stores a preset “offset amount (γ) of a fold position that is set between the sheet center Sc and the binding position Sp and is offset from the sheet center Sc by a predetermined amount”.

“Case 2 (St25)”
The control unit 100 calls a binding position offset value (γ) to be executed from a data table preset from the sheet size information (St26) and the sheet bundle thickness information (St27) and stored in the ROM 99 (St28). In this case, the sheet size information is sent from the image forming apparatus A and uses data (or stored data thereof). Further, the sheet bundle thickness information is calculated from the total number of pages constituting the sheet bundle and the average paper thickness, or the thickness of the sheet bundle is actually measured although not shown. The ROM 99 prepares the “folding position offset value (γ)” divided into a plurality of a segments, b segments, c segments, and the like by sheet bundle thickness (or the number of sheets) for each sheet size. By this method, the fold position of the sheet bundle is set according to the sheet bundle size.

“Case 3 (St29)”
The control unit 100 reads an offset amount reference value that is preset according to the sheet size and stored in the ROM 99 from the sheet size information (St30) and the sheet bundle thickness information (St31) (St32). Then, the control unit 100 calculates the folding position offset amount (γ) based on the offset amount reference value and the bundle thickness of the sheet bundle (St33).

  The folding position offset amount (γ) is calculated as follows, for example. The bundle thickness of the sheet bundle is calculated from the data volume designated by the image forming apparatus A or the number of pages on which image formation is performed, or calculated as “total number of pages × average sheet thickness” from the page information included in the image formation data. To do. Alternatively, the number of sheets carried into the sheet support surface 41a is counted, and the sheet bundle thickness is determined by (total sheet count × paper thickness) (St31).

  Then, the control means 100 corrects the reference offset value with the sheet bundle thickness and sets “the folding position offset value (γ) to be executed”. The correction value is, for example, (reference value from ROM 99; γ) × (bundle thickness; total number of pages * paper thickness) / reference bundle thickness (standard bundle thickness stored in ROM). With such a calculation method, the offset value is large (away from the sheet center Sc) when the bundle thickness of the sheet bundle is thick, and the offset value is small (closer to the sheet center Sc) when the bundle thickness is thin. Set the standard bundle thickness.

  As described above, the control unit 100 sets the folding position offset value (γ) by any one of the cases 1 to 3 (St34). Next, the control unit 100 sets the movement amount of the sheet bundle (movement amount from the binding position to the folding position in the first embodiment of FIG. 2). The movement amount (conveyance amount) of the sheet bundle is calculated by the physical distance (distance) between the binding processing means 39 and the folding processing means 44 and the folding position offset value (γ). For example, [sheet bundle movement amount = (binding position−folding distance) − (offset value; γ)] is set (St35).

  Next, the control means 100 operates the conveyor means 42 that conveys the sheet bundle according to the sheet bundle movement amount (γ) set in step St35. This conveyor means has a function of conveying the sheet bundle that has been bound at the binding position Sp to the folding position Sf, and in the first embodiment shown in FIG. 2, the sheet support surface 41a is inclined so that the sheet bundle falls under its own weight. The leading end portion (the leading portion in the dropping direction) of the sheet bundle is locked by the sheet end regulating means 42. When the sheet end regulating means 42 is moved, the sheet bundle is driven following the movement.

  That is, in the first embodiment, the sheet end regulating means 42 is configured as a conveyor means for moving the sheet bundle by moving from the binding position Sp to the folding position Sf. In addition, the conveyor means 42 can employ a belt conveyance mechanism, a roller conveyance mechanism, and the like that nip and convey the sheet bundle.

  Then, the control means 100 operates the conveyor means 42 to move the sheet bundle to the folding processing position (nip position of the folding roller pair) (St36).

  The control unit 100 positions the fold position Sf of the sheet bundle between the sheet center Sc and the binding position Sp at a position offset by a predetermined amount (offset value γ) from the sheet center. In the first embodiment described above, the offset amount is set by the transport amount of the sheet bundle by the conveyor means 42, and in the second, third, and fourth embodiments described above, positioning is performed by a method that will be described later, which is different from this.

  Next, the control means 100 operates the folding processing means 44. In the first embodiment, the pair of folding rolls 44a and 44b are rotated in the folding processing direction, and at the same time, the folding blade 45 is moved from the standby position separated from the sheet bundle (set in the folding processing position) to the roller nip portion. Move to position. In this blade movement, the rack 45r formed integrally with the folding blade 45 is rotated forward and backward by the pinion 45p connected to the shift motor M1 (St37).

  The sheet bundle is folded at the positioned fold position Sf by the rotation of the folding roll pair 44, and is conveyed to the downstream side by the rotation of the roller pair 44 (St38). A trimmer unit 49 is disposed in the paper discharge path 46 on the downstream side of the folding roller pair 44.

  Therefore, the control unit 100 determines whether or not to trim the sheet bundle (St39). This determination follows the instruction selected by the operator as to whether or not to trim in the setting of the post-processing mode. When the trimming process is not performed, the control unit 100 rotates the paper discharge roller pair 88 (conveyance roller) in the paper discharge path and stores the sheet bundle in the stack tray 50 disposed on the downstream side (St44).

  When trimming is performed, the control unit 100 detects the leading edge of the sheet bundle by the sheet discharge path sensor Se4 (St40), and conveys the sheet bundle by a predetermined amount upon receiving the detection signal (St41). Then, the paper discharge roller pair 88 is stopped, and the sheet bundle is set at the cutting position Cp.

  Next, the control unit 100 presses and holds the sheet bundle at the cutting position Cp with the paper pressing mechanism 87 (St42), and performs cutting processing with the cutting blade 47 (St43). After executing the cutting operation, the control unit 100 carries the sheet bundle from the paper discharge path 46 to the stack tray 50 (St44).

A Image forming apparatus B Post-processing apparatus 21 Carriage entrance 25 Conveying path 39 Binding processing means (press binding mechanism)
40 Second post-processing section 41 Accumulation guide 41a Sheet support surface 42 Sheet edge regulating means (stopper member)
42s Stopper surface 42p Pinion 42r Rack 43 Folding mechanism 44 Folding roll means 45 Folding blade 46 Discharge path 47 Cutting blade 48 Paper mount 49 Trimmer unit 50 Storage section (magazine tray)
72 Binding processing means (modified example)
73 First Roller (Third Embodiment)
74 Second Roller (Third Embodiment)
75 Third roller (third embodiment)
76 Folding roller mechanism (second embodiment)
85 Folding roll mechanism (Third embodiment)
86 Unit frame 87 Paper holding member 88 Bundle conveying means (paper discharge roller pair)
100 Post-processing control unit Sp Binding position Sc Sheet center Sf Folding position Cp Cutting position

Claims (8)

A binding processing means for processing binding the substantially central portion of the sheet over sheet bundle, and a processing unit comprising a folding processing means for folded handle sheet substantially central portion after the stapling process,
A cutting means for cutting process the fore side of the folding process sheet bundle is arranged downstream of the pre-Symbol folding means,
With
The binding processing means includes:
The sheet bundle mentioned binding processing at the binding position a predetermined distance away from the sheet center,
The folding processing means includes
Against the innermost sheet in the sheet bundle, the sheet processing apparatus, which comprises the folding process by a predetermined amount displaced folding position to the binding position side from the sheet center between the binding position and the sheet center. In the processing unit,
A sheet bundle conveyor means is arranged,
The conveyor means includes
The sheet processing apparatus according to claim 1, further comprising a shift mechanism that moves the sheet bundle from a binding processing position of the binding processing unit to a folding processing position of the folding processing unit. When conveying a sheet bundle from the binding processing position to the folding processing position,
The control means of the conveyor means
The sheet processing apparatus according to claim 2, wherein the movement amount of the shift mechanism is set so that the folding processing position of the sheet bundle is located between the binding position and the center of the sheet. On the upstream side of the processing unit,
Sheet transport path is arranged,
In the processing unit,
A sheet support surface disposed on the downstream side of the transport path;
A restriction stopper member of a sheet edge disposed on the sheet support surface;
A shift mechanism that moves the stopper member in a direction perpendicular to the fold direction of the sheet bundle;
Is placed,
The sheet support surface is disposed at an inclination angle at which the sheet falls by its own weight,
The sheet processing apparatus according to claim 1, wherein the restriction stopper member has a stopper surface that locks a lower end edge of the sheet. On the upstream side of the processing unit,
Sheet transport path is arranged,
In the processing unit,
The sheet support surface disposed on the downstream side of the transport path;
Sheet bundle binding means;
Sheet folding processing means;
Is provided,
The binding processing means and / or folding processing means,
The unit frame is mounted on a unit frame that is movable with respect to the sheet support surface, and the unit frame is provided with a shift unit that moves the binding processing unit or the folding processing unit. The sheet processing apparatus according to claim 1. The cutting means is
A paper platform for supporting the sheet bundle sent from the folding processing means;
A cutting blade that moves up and down with respect to the sheet bundle on the paper platform;
Consists of
The paper platform is
The folded sheet bundle is folded up with the folding half having the binding position on top.
2. The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is disposed so that the folded half on the opposite side faces downward. The folding processing means includes
Folding processing mechanism,
Positioning means for relatively moving the folding processing mechanism and the sheet bundle;
Consists of
The sheet processing apparatus according to claim 1, wherein the positioning unit varies the amount of displacement between the sheet center and the folding position according to the bundle thickness of the sheet bundle. The positioning means is provided with a bundle thickness discriminating means for the sheet bundle,
The bundle thickness determining means is a bundle thickness detecting means for detecting the sheet bundle of the processing unit or a sheet number counting means for counting the number of sheet bundles.
The sheet processing apparatus according to claim 7, wherein the sheet processing apparatus is configured.

Images