JP5778973B2 - Sheet folding apparatus and image forming system provided with the same - Google Patents

Description

  The present invention relates to a sheet folding apparatus that folds an image-formed sheet, and more particularly to a sheet folding apparatus that can fold a sheet at an accurate crease position with a simple structure and an image forming system including the sheet folding apparatus.

  In general, this type of sheet folding apparatus is widely known as an apparatus for folding and finishing a sheet image-formed by an image forming apparatus such as a printing machine, a printer apparatus, or a copying machine at a predetermined folding position. In addition, there is a device that is connected to a paper discharge port of an image forming apparatus and folds an image-formed sheet for filing and carries it out to a subsequent binding processing apparatus. Thus, the sheet folding apparatus that folds the sheet in half or one-third and carries it out is configured as a post-processing apparatus of the image forming apparatus, or is built in the image forming apparatus or the binding processing apparatus. It is configured as a unit.

  The folding specifications by such a sheet folding apparatus are known in various forms depending on the purpose of use, such as 1/2 folding, 1 / 3Z folding, and 1/3 letter folding, for example. For those that need to be folded in three, such as / 3Z fold and 1/3 letter fold, the folding process is performed twice.

  By the way, when the folding process is performed twice, for the primary folding, since the sheet is conveyed while being held and regulated by the conveying means, the primary folding is performed by measuring the timing after detecting the leading edge of the sheet. It can be said that it is easy to accurately detect the crease position. However, since the secondary fold is formed by nipping a sheet that is primarily folded and fed in a relatively free state to form a secondary fold, the fold position at the time of nip varies and an accurate fold is formed. There was a problem of not being.

  Therefore, there is a configuration in which a sheet is nipped and folded at a certain position by applying a restriction to the stopper by abutting the leading end of the sheet conveyed to form a secondary fold with a stopper. However, since the sheet folding apparatus using such a stopper regulates the leading end of the sheet against the stopper, the distance between the stopper and the folding roller pair becomes relatively long. There was a problem that the sheet was easily loosened between the pair.

  For this reason, a sensor is provided on the downstream side of the pair of folding rollers in the sheet conveyance direction. When the sensor detects that the sheet has reached a predetermined distance downstream, the brake means stops the sheet, but the sheet conveyance is continued. A configuration has been known in which a loop of a sheet generated by the nip is nipped by a pair of folding rollers to form a crease (see, for example, Patent Document 1).

  When a roller pair capable of forward / reverse rotation is provided on the downstream side of the folding roller pair and the front end of the sheet comes into contact with the stopped roller pair, the roller pair rotates forward to hold the sheet, and then reverses. A configuration is known in which a loop is formed on a sheet, and a pair of folding rollers nips the loop to form a fold (see, for example, Patent Document 2).

JP 2000-44115 A JP 2006-76776 A

  Thus, in the prior art, a loop is formed by using a brake member or a roller pair instead of a stopper to stop the movement of the sheet in one direction and at the same time carry it in the reverse direction. However, since there is a distance from the stop / conveyance position of the sheet to the space where the loop is formed, the sheet becomes unstable in the conveyance path, and even these methods cannot provide sufficient folding accuracy.

  Therefore, the present invention eliminates the variation in the folding position caused by the looseness of the sheet and performs highly accurate secondary folding while utilizing the superiority of the stopper that can reliably regulate the sheet when the sheet hits. A realizable sheet folding apparatus is provided.

In order to achieve the above object, a sheet folding device according to the present invention is a sheet folding device for forming a fold in a sheet conveyed in a conveyance path, and a first folding roller located upstream in the sheet conveying direction; A second folding roller that is positioned on the downstream side and rotates in contact with the outer peripheral surface of the first folding roller, and forms a first fold on the sheet; the second folding roller; A second folding roller pair configured to form a secondary fold on the sheet on which the primary fold is formed , and a third fold roller that rotates in contact with the outer peripheral surface of the second fold roller ; A folding deflecting member that is in contact with the outer peripheral surface of the second folding roller and guides the fold of the sheet to a nip position of the first folding roller pair; and a leading end of the sheet on which the primary folding is formed at a predetermined position. Hit A stopper member intoxicated provided, the tip of the sheet to the stopper member is a guide member for guiding the sheet to the nip position of the second folding roller pair when it reaches a Bei obtain this and characterized.

The guide member is movable between a standby position and an operating position, and when the sheet folded primarily by the first folding roller pair is conveyed to the stopper member, the standby position And when the leading edge of the sheet reaches the stopper member, the sheet moves to the operating position .

Further, the guide member starts to move from the retracted position to the operating position immediately before the sheet comes into contact with the stopper member .

The predetermined position of the stopper member where the leading edge of the sheet abuts moves according to the size and folding position of the sheet .

The stopper member may be moved in a switchback path for forming the secondary fold formed along a direction substantially orthogonal to the conveyance direction of the sheet conveyed to the conveyance path .

  The folding deflection member includes a driven roller in which the first folding roller pair is in contact with the outer peripheral surface of the second folding roller at an operating position near the nip position of the sheet.

  The folding deflecting member is further disposed along a roller circumferential surface of the first folding roller, and a nip formed by the first folding roller and the second folding roller is formed on the primary folding line of the sheet. It is characterized by having a curved guide having a curved shape leading to the part.

  The guide member has a protrusion corresponding to the nip position so as to guide the sheet to the nip position for the secondary folding in the second folding roller pair, and both sides extending from the protrusion. Each of the second folding roller and the third folding roller is opposed to each other and has a shape along the outer peripheral surface.

  Further, the guide member is movable between a standby position and an operating position, and when the sheet primarily folded by the first folding roller pair is conveyed to the stopper member, the standby position And when the leading edge of the sheet reaches the stopper member, the sheet moves to the operating position.

  A sheet folding apparatus that forms a fold in a sheet conveyed in a conveyance path, and is in contact with an outer peripheral surface of a first folding roller located on an upstream side in a sheet conveying direction and a downstream side. And a second folding roller that rotates in the opposite direction and forms a primary fold on the sheet, and presses against the outer peripheral surface of the second folding roller, and the sheet is at the nip position of the first folding roller pair. The sheet is formed of a fold deflecting member that guides the fold of the fold, a second fold roller, and a third fold roller that rotates in the opposite direction in contact with the outer peripheral surface of the second fold roller. A second folding roller pair for forming a next fold, a stopper member provided so as to abut against a leading edge of the sheet on which the primary fold has been formed, and the sheet on which the primary fold has been formed And operating position to guide the nip position of the second folding roller pair, is characterized by and a guide member movable between a retracted position retracted from the operating position.

  An image forming system according to the present invention includes an image forming apparatus that sequentially forms an image on a sheet and the sheet folding apparatus that folds a sheet from the image forming apparatus.

  According to the present invention, since the sheet to be secondarily folded is regulated at the abutment with the stopper member and then guided to the nip position of the secondary folding roller, the sheet is not loosened. It was possible to accurately and stably apply the sheet folds without causing variations in position.

1 is an explanatory diagram of an overall configuration of an image forming system according to the present invention. FIG. FIG. 2 is an explanatory diagram of an overall configuration of a sheet folding apparatus in the system of FIG. 1. The principal part expansion explanatory drawing in the sheet folding apparatus of FIG. 3 is shown. Explanatory drawing of a guide member in a folding roller and a standby position is shown. Explanatory drawing of a guide member in a folding roller and an operation position is shown. The schematic explanatory drawing of each drive mechanism of a guide member and a stopper member is shown. The perspective view for demonstrating the arrangement configuration of three folding rollers, a guide member, and a stopper member is shown. The explanatory view which shows Drawing 7 from the back is shown. It is explanatory drawing of the sheet folding specification in the sheet folding apparatus of this invention, (a) part folds a sheet | seat inside three at 1/3 position, (b) part Z-folds a sheet | seat at 1/3 position. Mode (c) shows a mode in which the sheet is Z-folded at a 1/4 position. The control structure in the system of FIG. 1 is shown. FIG. 3 is a state explanatory diagram of a sheet folding operation in the apparatus of FIG. 2 and shows a state in which a sheet is carried into a first switchback path. FIG. 3 is a state explanatory diagram of a sheet folding operation in the apparatus of FIG. 2 and illustrates a state in which the sheet is primarily folded at a first nip position. FIG. 4 is a state explanatory diagram of a sheet folding operation in the apparatus of FIG. 2, showing a state in which a primarily folded sheet is carried into a second switchback path. FIG. 4 is a state explanatory diagram of a sheet folding operation in the apparatus of FIG. 2 and illustrates a state in which a sheet is folded from a second switchback path at a second nip position. FIG. 4 is a state explanatory diagram of a sheet folding operation in the apparatus of FIG. FIG. 4 is a state explanatory diagram of a sheet folding operation in the apparatus of FIG. 2, and shows an operation of a guide member that guides the sheet leading end to the second nip position when the bi-folding mode is executed. 3 is a flowchart showing a folding processing operation by the apparatus of FIG. The principal part expansion explanatory drawing of the post-processing apparatus in the system of FIG. 1 is shown.

  Hereinafter, the present invention will be described in detail based on the illustrated embodiment.

  FIG. 1 shows an image forming system according to the present invention. This system includes an image forming apparatus A and a post-processing apparatus C, and a sheet folding apparatus B is attached to the post-processing apparatus C as a unit.

  The image forming apparatus A includes a printer, a copier, a printing machine, and the like that sequentially form images on sheets. The illustrated one is an image forming unit 7, a document reading unit 20, and a feeder unit (document feeding device) 25 as a composite copying machine having a copying machine function and a printer function. The post-processing apparatus C is connected to the main body discharge port 18 of the image forming apparatus A, and is configured to perform post-processing such as folding processing, punching, stamping processing, and binding processing on the image-formed sheet. Has been. A folding processing unit (sheet folding device) B for folding the image-formed sheet is integrally provided in the post-processing device C. Hereinafter, the sheet folding apparatus B, the image forming apparatus A, and the post-processing apparatus C will be described in this order.

[Sheet folding device]
The sheet folding apparatus B is built in the image forming apparatus A or the post-processing apparatus C, or is configured as an independent apparatus (stand-alone configuration). The illustrated one is arranged between the image forming apparatus A and the post-processing apparatus C to constitute an image forming system. The sheet folding apparatus B is attached to the post-processing apparatus C as an optional unit.

  The entire structure of the sheet folding device B is shown in FIG. 2, but a carry-in port 30 and a carry-out port 31 are provided in the device housing 29, and the carry-in port 30 is located at a position connected to the main body discharge port 18 of the upstream image forming apparatus A. The carry-out port 31 is arranged at a position continuous with the sheet receiving port 69 of the downstream post-processing apparatus C. In this way, the carry-in port 30 and the carry-out port 31 are disposed so as to cross the device housing 29.

  Between the carry-in port 30 and the carry-out port 31, the sheet from the carry-in port 30 is folded without being folded, and the sheet from the carry-in port 30 is folded. A second transport path 33 for carrying out to the carry-out port 31 is provided. Therefore, a “conveying mechanism” for transferring the sheet in a predetermined direction and a “folding mechanism” for folding the sheet are arranged in this path.

[Route configuration]
As shown in FIG. 2, a first transport path (hereinafter referred to as “first path”) 32 is disposed in the apparatus housing 29 between the carry-in port 30 and the carry-out port 31. As shown in the figure, this path may be arranged in a horizontal direction as a straight path, or may be arranged in a vertical direction even if it is constituted by a curved path. As described above, the first path 32 guides the sheet from the carry-in entrance 30 to the carry-out exit 31 without folding the sheet.

  A second conveyance path (hereinafter referred to as “second path”) 33 is configured as a path for folding the sheet from the carry-in entrance 30. In the second path 33, a folding processing means 48 described later is disposed at a folding position Np1 (Np2), and a first switch for guiding a sheet leading end for primary folding to the folding position (first nip position described later) Np1. The back path 34 and a second switchback path 35 that guides the leading end of the folded sheet for folding the folded sheet to a folding position (second nip position described later) Np2. The second path 33 is continuously provided with a third transport path (hereinafter referred to as “third path”) 36 for transporting the folded sheet from the second nip position Np2 toward the transport outlet 31.

  The second path 33 intersects the first path 32 in a substantially orthogonal direction, and a path end that guides the sheet above the first path 32 and a path end that guides the sheet below the first path 32. It consists of parts. In the embodiment of FIG. 2, the first switchback path 34 that guides the leading edge of the sheet to the first nip position Np <b> 1 to be folded is located above the first path 32, and the second switchback that guides the folded sheet to the downstream side. The path 35 is disposed below the first path 32.

  Thus, the first path 32 and the second path 33 are arranged so as to intersect in a substantially orthogonal direction, but the first switchback path 34 that guides the sheet to the primary folding position (first nip position described later) Np1. May be disposed below the first path 32 and a second switchback path 35 for guiding the folded sheet downstream may be disposed above the path 32.

  When the first path 32 is arranged in the vertical direction, the first switchback path 34 is on the right side (or left side) of the first path 32 in the vertical direction, and the second switchback path 35 is on the left side (or right side) of the path. ). In the embodiment shown in FIG. 3, the second switchback path 35 reverses the sheet feeding direction in order to guide the folded sheet to the second nip position Np2 (see FIG. 5) for secondary folding of the sheet. However, when the sheet is not subjected to secondary folding, a straight path may be used.

  A third path 36 that guides the folded sheet to the carry-out port 31 is connected to the second path 33. The illustrated third path 36 is provided between the second nip position Np2 where the sheet is secondarily folded and the carry-out port 31. The third path 36 is provided with a paper discharge path 37 for guiding the folded sheet from the paper discharge outlet 51 different from the carry-out port 31 to the storage stacker 65.

  The first switchback path 34 for forming the primary fold configured as described above and the second switchback path 35 for forming the secondary fold are each configured by a path curved in an arc shape. Further, the paper discharge path 37 connected to the third path 36 is also configured as a path curved in an arc shape.

  Then, the path length (L1) of the first switchback path 34 for guiding the sheet from the first path 32 to the primary folding position (first nip position) Np1, and the primary folded sheet at the secondary folding position (L1). The path length (L2) of the second switchback path 35 for guiding to the second nip position) Np2 is configured such that path length L1> path length L2.

  Further, the path length L3 of the sheet discharge path 37 for guiding the folded sheet from the second nip position Np2 to the storage stacker 65 is configured to satisfy L3 <L2 <L1. This is because when the primary folding position (first nip position) Np1 is arranged in the vicinity of the first path 32, each path length becomes L3 <L2 <L1, resulting in a compact path configuration.

  The first switchback path 34 and the second switchback path 35 constituting the second path 33 are formed in an S-shaped curve as shown in FIG. The second switchback path 35 is connected to the storage stacker 65 and the paper discharge path 37.

  Accordingly, the first switchback path 34 having the longest path length is arranged above the first path 32, the second switchback path 35 and the paper discharge path 37 having short paths are arranged below the first path 32, and further below that. A storage stacker 65 is disposed in the storage. With such a layout configuration, the inner space of the device housing 29 can be concentrated.

[Folding processing means]
The folding processing means 48 for folding the sheet in the second path 33 guides the sheet fold to the folding rollers 41b, 49, 50 for folding the sheet in half or in three and its nip position Np1 (Np2). Therefore, it is composed of a folding deflection member 53 and a guide member 54 for deflecting the sheet conveyance direction. The first folding roller pair 100 that forms a primary fold on the sheet at the nip position Np1 is formed by folding the sheet into the three-folded sheet by performing the second-folding and then the folding roller 41b and the folding roller 49 that rotate in opposite directions. The folding roller 49 and the folding roller 50, which also rotate in opposite directions, are configured as a second folding roller pair 101 that forms a secondary fold on the sheet at the nip position Np2 (FIG. 4 and FIG. 5). And FIG. 5). The folding processing mechanism of this tri-fold specification will be described below.

[Route switching means]
As described above, the first path 32 and the second path 33 are arranged to intersect each other, the first switchback path 34 is above the first path 32, and the second switchback path 35 is below the first path 32. In the second path 33, a third path 36 for returning the folded sheet from the second nip position Np2 to the first path 32 is connected.

  As shown in FIG. 2, the first route 32 and the second route 33 intersect with each other at Cp1, and the third route 36 and the first route 32 intersect with each other at Cp2. Therefore, the path switching for guiding the seat from the first path 32 to the first switchback path 34, the path guide for guiding the seat from the first switchback path 34 to the second switchback path 35, and the second switchback path 35 A route guide for guiding the sheet to the first route 32 is required.

  The illustrated apparatus achieves the above-described three-way guide with the following one path switching means 63. A route switching means 63 is disposed on the first route 32 at the intersection with the second route 33. As shown in FIG. 3, the path switching means 63 has a base end portion 63x that is pivotally supported by an apparatus frame support shaft 62x outside the path, and a front guide surface 63a and a back guide surface 63b are formed at the tip portion. Has been.

  The front guide surface 63a guides the sheet sent to the first path 32 in the solid line posture of FIG. 3 from the first path 32 to the first switchback path 34 of the second path 33. At the same time, the back guide surface 63 b returns the folded sheet sent to the third path 36 to the first path 32. Further, the path switching unit 63 directly sends the sheet sent to the first path 32 in the broken line posture (only the base end portion 63 x is illustrated) in FIG. 3 without being carried into the second path 33.

  In this way, the path switching means 63 is sent from the carry-in entrance 30 to the first transport path, and the first guide posture (the broken line in FIG. 3) that directly sends the sheet from the carry-in entrance 30 to the carry-out exit 31 through the first path 32. The posture of the sheet is changed between the second guide posture (solid line in FIG. 3) for guiding the sheet to the second conveyance path and guiding the sheet sent from the third path 36 to the first path 32. This is achieved by the driving means 45 (FIG. 10). The path switching drive means 45 is a solenoid whose drive is controlled by a folding processing control unit 95a that will become apparent later. Therefore, the solenoid and the return spring are coupled to the base end portion of the path switching means 63 formed of a plate-like piece that swings around the support shaft 62x.

  In this way, the path switching means 63 guides the sheet from the first path 32 to the first switchback path 34 in the second guide posture, and guides the sheet from the switchback path to the first nip position Np1. At the same time, the folded sheet from the third path 36 is returned to the first path 32 in the second guide posture.

[Folding roller configuration]
As shown in FIG. 3, the first folding roller 41 b, the second folding roller 49, and the third folding roller 50 that constitute the folding processing unit 48 are arranged in the second path 33 in pressure contact with each other. The second folding roller 49 is located on the downstream side of the first folding roller 41 b in the sheet conveying direction of the first path 32 and at a position away from the first path 32. The first folding roller 41b rotates in the forward direction that feeds the sheet from the carry-in entrance 30 to the carry-out exit 31, the second folding roller 49 rotates in the reverse direction, and the third folding roller 50 rotates in the forward direction. A first nip position (first folding position) Np1 for primary folding of the sheet is formed at the pressure contact point between the first folding roller 41b and the second folding roller 49, and the second folding roller 49 and the third roller 50 are A second nip position (second folding position) Np2 for secondary folding of the sheet is formed at the pressure contact.

  In particular, in the illustrated apparatus, the circumferential surface of the first folding roller 41b is disposed at a position facing the first path 32, and a pinch roller (floating roller) 41a is pressed against the circumferential surface of the roller. As a result, the sheet in the first path 32 is conveyed by the first folding roller 41b and the pinch roller 41a, and there is no need to provide a special conveying member and its driving mechanism in the first path 32. An additional folding roller (drive roller) 64 is pressed against the second folding roller 49 on the downstream side of the pressure contact with the third folding roller 50.

[Configuration of folding deflection means]
The configuration of the deflection member 53 and the guide member 54, which are folding deflecting means that constitute the above-described folding processing means together with the folding rollers (41b, 49, 50), will be described. The three folding rollers (41b, 49, 50) are provided with a folding deflecting member 53 at a first nip position Np1 and a guide member 54 at a second nip position Np2, and a sheet at each nip position (pressure contact). Guide the folds. As shown in FIG. 3, the folding deflecting member 53 includes a driven roller 53a, a curved guide 53b, and a rack 53c.

  The first nip position Np1 for primary folding of the sheet is formed by a first folding roller pair 100 including a first folding roller 41b disposed on the upstream side and a second folding roller 49 disposed on the downstream side. However, the driven roller 53a is disposed at a position in contact with the peripheral surface of the second folding roller 49 during operation indicated by a broken line. The curved guide 53b includes a curved guide surface along the circumferential surface of the first folding roller 41b located on the upstream side.

  The folding deflection member 53 is supported by the guide rail and reciprocates in the vertical direction by forward and reverse rotation of the pinion 53p meshing with the rack 53c, so that the driven roller 53a is in contact with the peripheral surface of the second folding roller 49 ( The position moves up and down between the position of the broken line in FIG. 4 and the standby position retracted out of the second path 33 (solid line position in FIG. 4).

  A sheet to be folded that is introduced from the carry-in entrance 30 is nipped and fed out by a first folding roller 41b and a pinch roller 41a that is in pressure contact with the first folding roller 41b. When the driven roller 53a is pressed against the second folding roller 49 located on the downstream side by the lowering of the folding deflecting member 53, the front end portion of the sheet fed from the first folding roller 41b and the pinch roller 41a becomes the curved guide 53b. While receiving the conveying force in the opposite direction from the driven roller 53a and the second folding roller 49, the rear end portion of the sheet newly fed out from the first folding roller 41b and the pinch roller 41a is guided by the curved guide 53b to be nipped. In order to move toward the position Np1, the entire sheet is guided to the first nip position Np1 along the peripheral surface of the second folding roller 49 while forming a loop. The loop is nipped by the first folding roller 41b and the pinch roller 41a, thereby forming a fold in the sheet.

  On the other hand, the guide member 54 has a protrusion corresponding to the nip position so as to guide the sheet to the nip position Np2 of the second folding roller pair 101, and the second folding in which both sides extending from the protrusion face each other. It has a substantially triangular shape along the outer peripheral surfaces of the roller 49 and the third folding roller 50, and is configured to be movable between a retracted position and an operating position as shown in FIG. As a result, when the guide member 54 moves from the retracted position to the operating position, the sheet on which the primary folding is formed by the first folding roller pair 100 is guided to the nip Np2 position of the second folding roller pair 101 and is nipped. A secondary fold will be formed.

  As will become apparent later, the stopper member 86 restricts the sheet, so that the sheet forms a loop in the space formed by the outer peripheral surfaces of the second folding roller 49 and the third folding roller 50. By guiding this loop to the nip position Np2, the sheet is secondarily folded.

  As shown in FIGS. 4, 5, and 6, the guide member 54 is attached to a rotation plate 54a that is pivotally supported about the rotation axis of the first folding roller 41b, and the rotation plate 54a. Is biased by a spring 56 in a direction in which the guide member 54 is positioned at the retracted position. The guide member 54 has an abutment piece 54 b, and resists the urging force of the spring 56 and presses the abutment piece 54 b with the cam 57 toward the nip Np 2 position of the second folding roller pair 101. Move to reach operating position.

  A free wheel 58 is attached to the rotation shaft 57b of the cam 57, and is coupled to the drive shaft of the motor M1 via a pulley 89 and a gear group (not shown) on which a belt is mounted together with the free wheel 58. Yes. Accordingly, when the motor M1 stops driving after the cam 57 moves the guide member 54 to the operating position by pressing the contact piece 54b by driving the motor M1, the load from the motor M1 side is applied by the free wheel 58. Without being hooked, the rotating plate 54a is rotated by the return force of the spring 56, and the guide member 54 is returned to the retracted position. At the same time, the cam 57 also returns to the state where the pressing force of the contact piece 54b is started. In addition to the drive of the cam 57, the motor M1 supplies each drive force of the drive mechanism described below through the gear group.

[Drive mechanism]
Next, the drive mechanism of the first path 32, the second path 33, and the folding processing means 48 will be described. The roller 40b is arranged on the carry-in entrance 30 side of the first path 32, the roller 62b is arranged on the carry-out exit 31 side, and the folding roller 41b is arranged in the middle. These rollers 40b and 62b and the roller 41b are respectively connected to the drive shaft of the same motor through gears. Then, the roller 40a is in contact with the roller 40b, the pinch roller 41a is in contact with the folding roller 41b, and the roller 62a is in contact with the roller 62b to rotate.

  The first switchback path 34 and the second switchback path 35 constituting the second path 33 are not provided with conveying means such as a roller and a belt for applying a conveying force to the sheet. Therefore, the first switchback path 34 is provided with a first folding roller 41b and a pinch roller 41a that is in pressure contact with the first folding roller 41b so as to convey the sheet in the loading direction, and is in contact with the second folding roller 49. The roller 53a is configured to apply a conveying force for transferring the sheet from the path to the primary folding position Np1.

  Further, the second switchback path 35 is given a conveying force for carrying the sheet into the path at the nip position between the first folding roller 41b and the second folding roller 49, and the sheet is fed out from the path to the secondary folding position Np2. The conveying force is configured to be applied by the guide member 54. In the third path 36 connected to the second switchback path 35, as shown in FIG. 4, an additional folding roller 64 pressed against the second folding roller 49 is folded toward the rollers 62a and 62b of the carry-out port 31. The conveyance force to carry out is given. Therefore, no conveying means having a special drive mechanism is arranged in the third path 36.

  Further, in the above-described third path 36, a paper discharge path 37 that guides the folded sheet to the storage stacker 65 without being transferred to the carry-out port 31 is disposed, and a paper discharge roller 67 is provided in this path. .

[Sheet edge detection sensor]
As described above, the first sensor S <b> 1 that detects the edge of the sheet is disposed in the first path 32, and detects the edge (leading edge and trailing edge) of the sheet that is carried into the first switchback path 34. Further, a second sensor S2 for detecting the edge of the sheet carried into the second switchback path 35 is disposed. The sensors S1 and S2 detect the edge of the sheet in order to determine the fold position of the sheet, and the operation thereof will be described later together with a folding specification described later.

[Stopper member]
The sheet on which the primary folding is formed by the first folding roller pair 100 is sent to the second switchback path 35, and then the second folding is formed by the second folding roller pair 101, but an accurate fold is formed. In order to control the position of the sheet, the stopper member 86 is provided in the second switchback path 35 so that the leading edge of the moving sheet abuts.

  As shown in FIG. 7, the stopper member 86 constitutes the second switchback path 35 in order to support the front end surface in the moving direction of the sheet conveyed in the second switchback path 35 over the entire width. A claw 86a is projected into the path 35 from a plurality of long holes 35c formed in the partition wall 35b. The position of the sheet is regulated by abutting against the claw 86 a of the stopper member 86.

  Then, the sheet forms a loop in the second switchback path 35 by the restriction of the stopper member 86, but the guide member 54 moves from the retracted position to the operating position so as to guide the sheet to the nip position Np2 following the loop. To do. At this time, the guide member 54 has a substantially triangular shape along the outer peripheral surfaces of the second folding roller 49 and the third folding roller 50 that have projections and both sides extending from the projections face each other. Therefore, when it moves to the operating position, it becomes a wedge to the space formed by the outer peripheral surfaces of the second folding roller 49 and the third folding roller 50, and the space in which the sheet forms a loop is narrowed. As a result, the sheet always forms a constant loop, and the guide member 54 guides the sheet to the nip position Np2 of the second folding roller pair 101 for each sheet at an accurate crease position, thereby providing a highly accurate secondary. Can be folded.

  Since the fold position of the sheet varies depending on the size of the sheet and the specifications of the folding process, the stopper member 86 is formed in the second switchback path 35 along a direction substantially perpendicular to the sheet conveyance direction by the first path 32. The position can be varied by moving within the straight portion 35a according to these conditions. That is, the stopper member 86 is attached to a rack 87 provided so as to be movable in the vertical direction along the straight portion 35 a of the second switchback path 35, and the rack 87 is moved by the rotation of the pinion 88. The position of contact with the front end of the sheet can be varied within the range of the straight portion 35a of the second switchback path 35. Therefore, by controlling the forward / reverse rotation and rotation speed of the motor M2 of the pinion 88 according to the paper size and folding processing specifications, the leading edge of the sheet can abut against the stopper member 86 at a position suitable for the conditions.

[Registration mechanism]
In the first path 32, a registration mechanism is disposed between the pair of carry-in rollers 40a and 40b and the pinch roller 41a. This registration mechanism is provided with a registration member 43 provided with a regulating surface 43s that abuts and locks the leading end of the sheet between the carry-in roller 40b and the first folding roller 41b, and a registration area Ar (space) for bending and deforming the sheet. It consists of The registration member 43 is supported at its base end by the apparatus frame so as to swing around the support shaft 43x, and a regulating surface 43s for locking the leading end of the sheet moving in the first path 32 is formed at the leading end. ing.

  When the swingable resist member 43 is in the state shown in FIG. 3, the sheet fed from the carry-in rollers 40a and 40b loses its place in order to prevent the sheet moving along the first path 32 from moving. The sheet guide plate 32g constituting the one path 32 is curved in a loop shape within the resist area Ar formed. As a result, the skew which is a state in which the sheet is misaligned with respect to the traveling direction is corrected.

  When the resist member 43 is swung upward from this state, the sheet blocking by the regulating surface 43s is released, and the leading edge of the sheet is guided to the nip position between the pinch roller 41a and the folding roller 41b.

[Folding specification]
Next, the sheet folding method by the folding processing means 48 will be described with reference to FIG. A sheet on which an ordinary image is formed may be folded in two or three with a binding margin left for filing finish, or may be folded in two or three for letter finishing. In addition, in the case of tri-folding, there are cases where Z-folding and inner tri-folding are performed. In FIG. 9, the (a) part shows an inner trifold, the (b) part shows a 1 / 3Z fold, and the (c) part shows a 1 / 4Z fold.

  In the case of folding in half, the sheet fed to the second path 33 is folded by the first folding roller pair 100 at a half position of the sheet size or at a half position with a binding margin left at the end of the sheet ( Primary fold).

  In the case of tri-folding, the sheet sent to the second path 33 is folded by the first folding roller pair 100 at the 1/3 position of the sheet size or at the 1/3 position leaving a binding margin at the sheet edge. (Primary fold). The folded sheet is folded by the second folding roller pair 101 at the 1/3 position (secondary folding) and sent to the third path 36.

  At this time, in the case of folding in three as shown in FIG. 9A, the sheet fed to the second path 33 is folded at the 1/3 position of the sheet trailing edge side by the first folding roller pair 100. Next, the 1/3 position of the sheet front end side is folded. Similarly, in the case of 1 / 3Z folding shown in FIG. 9B, the sheet fed to the second path 33 is folded at the 1/3 position on the sheet leading end side by the first folding roller pair 100, and then the sheet trailing end. Fold the side 1/3 position.

  Further, in the case of three folding, when the 1/4 position shown in FIG. 9C is Z-folded, the sheet fed to the second path 33 is fed by the first folding roller pair 100 to the sheet trailing end side 1/4. The position is folded, and then the half position of the sheet is folded.

[Control means]
The configuration of the control means for folding the sheet will be described. A control CPU is mounted on the sheet folding apparatus B described above, or a folding processing control unit is provided in the control unit of the image forming apparatus A. The control unit is configured so that the following operation is possible.

  This will be described with reference to the control block diagram shown in FIG. In the image forming apparatus A, the controller panel 15 and the mode setting unit 92 are provided in the control CPU 91. The control CPU 91 controls the paper feeding unit 3 and the image forming unit 7 in accordance with the image forming conditions set on the controller panel 15. Then, the control CPU 91 transfers data and commands necessary for post-processing such as “post-processing mode”, “job end signal”, and “sheet size information” to the control unit 95 of the post-processing apparatus C.

  The control unit 95 of the post-processing apparatus C is a control CPU and includes a “folding processing control unit 95a” and a “post-finishing processing control unit 95b”. The folding processing control unit 95a includes a fold position calculating unit 97, a driver circuit for the motor M1, and a driver circuit for the motor M2. The control CPU 95 is transmitted with detection signals from the sensors S1 and S2. Further, an “ON” and “OFF” control signal is transmitted to the path switching means 63.

  The control CPU 95 stores in the ROM 96 a folding process execution program for controlling the motor M1, the motor M2, and the path switching means 63 so as to execute the folding specifications described above. Further, the RAM 98 stores data for calculating the sheet crease by the crease position calculation means 97 and the operation timing time of the motor M2.

  The fold position calculation means 97 calculates a fold position (dimension) from the leading end of the sheet (distal end in the paper discharge direction) from the “sheet length size”, “folding specification”, and “binding margin dimension”. It consists of For example, in the bi-fold mode, the sheet is folded at a half position in the paper discharge direction, or folded at a half position leaving a preset binding margin. The calculation of the crease position is calculated by, for example, [{(sheet length size) − (binding margin)} / 2].

  In the tri-fold mode, the fold position is calculated according to the folding specifications such as letter fold (inner fold, 1 / 3Z fold), filing fold (1 / 4Z fold, 1 / 3Z fold).

[Folding operation]
The operation of the configuration of the sheet folding apparatus B will be described. FIG. 11 shows a state in which the sheet is carried into the first switchback path 34 for primary folding. 12 shows a state where the sheet is folded at the primary folding position Np1, FIG. 13 shows a state where the folded sheet is carried into the second switchback path 35, and FIG. 14 shows a state where the sheet is folded at the secondary folding position Np2. Reference numeral 15 denotes a state where the folded sheet is carried out. FIG. 16 is an operation state diagram showing a folding operation in the bi-fold mode, and FIG. 17 is a flowchart of the control operation.

  In FIG. 11, the sheet guided to the carry-in entrance 30 is sent to the downstream side by the carry-in roller pair (first carrying means) 40, and after the skew is corrected by the above-described registration mechanism, the first path 32 first passes. A state of being introduced into the switchback path 34 is shown. The operation of the registration mechanism at this time is achieved by the folding processing control unit 95a controlling the stopper driving means 44. When the sheet is carried into the first switchback path 34 by the second conveying means 41, the sheet sensor S1 detects the leading edge of the sheet carried into the first switchback path 34.

  In FIG. 12, the folding processing control unit 95a moves the folding deflection member 53 from the standby position to the operating position at the timing when the sheet fold position is transferred to a predetermined position based on the signal detected by the sheet sensor S1. To do. Then, the sheet in the first path 32 is deformed into a V shape toward the first nip position Np1. When the driven roller 53a attached to the elevating member 53 comes into pressure contact with the peripheral surface of the second folding roller 49, the leading end of the sheet is fed out in the opposite direction (rotating direction of the second roller).

  On the other hand, the sheet rear end side feeds the sheet toward the first nip position Np1 by the conveying force of the second conveying means 41. At this time, the curved guide surface of the curved guide 53b regulates the sheet along the peripheral surface of the roller along the peripheral surface of the first folding roller 41b.

  Accordingly, the sheet is fed to the primary folding position Np1 at the leading end side thereof by the driven roller 53a and the trailing end side thereof by the second conveying means 41 toward the first nip position Np1. It will be determined. Therefore, the folding processing control unit 95a moves the sheet by the second conveying means 41 and the timing for moving the driven roller 53a from the standby position to the operating position (particularly when the roller contacts the peripheral surface of the second folding roller 49). Is previously set to an optimum value by experiment.

  Then, in synchronism with the movement of the driven roller 53a from the standby position to the operating position, the curved guide surface of the curved guide 53b guides the sheet along the peripheral surface of the opposing first folding roller 41b. There is no fear of the position changing each time.

  In FIG. 13, at the first nip position Np1, the ½ position (two folds), the （position (three folds), or the ¼ position (three folds) at the first nip position Np1 according to the timing when the folding deflecting member 53 advances to the operating position. The sheet that is primarily folded in step 1 is fed downstream at the first nip position Np1 and fed downstream.

  Therefore, the folding processing control unit 95a controls the motor M1 to place the guide member 54 in the operating position in the two-fold mode and in the standby position in the three-fold mode. The figure shows the control in the tri-fold mode. When the sheet is folded in half, the guide member 54 is positioned at the operating position, and the folded sheet is guided from the leading end to the second nip position Np2 and sent to the carry-out port 31 on the downstream side.

  In the three-fold mode, the folding processing control unit 95a positions the folding guide member 54 at the standby position as shown in FIG. Then, the sheet sent from the first nip position Np1 is sent from the leading edge to the second switchback path 35. The folding processing control unit 95a detects that the sheet primarily folded by the sensor S2 is sent to the second switchback path 35.

  Then, after a predetermined time has elapsed since the leading edge of the sheet folded primarily by the sensor S2, the folding processing control unit 95a controls the motor M1 to move the guide member 54 from the standby position to the operating position. The predetermined time at this time is the time from when the leading edge of the sheet is detected by the sensor S2 until it abuts against the stopper member 86, preferably until just before it abuts against the stopper member 86.

  At this time, the folding processing control unit 95a controls the motor M2 according to the sheet size of the sheet and the folding processing specifications to move the stopper member 86 in the linear portion 35a of the second switchback path 35. The time from when the leading edge of the sheet is detected by the sensor S2 until it abuts against the stopper member 86 is preset in the folding processing control unit 95a in accordance with the sheet size and folding processing specifications of the sheet, and the second switch When a predetermined time corresponding to the sheet being conveyed through the back path 35 has elapsed, the guide member 54 is moved from the standby position to the operating position.

  The guide member 54 has a substantially triangular shape along the outer peripheral surfaces of the second folding roller 49 and the third folding roller 50 that each have a protrusion and both sides extending from the protrusion face each other. Therefore, when the sheet is moved to the operating position, the space formed by the outer peripheral surfaces of the second folding roller 49 and the third folding roller 50 in which the sheet forms a loop is narrowed as described above. As a result, the sheet always forms a constant loop, and the guide member 54 guides an accurate fold position, so that a highly accurate secondary fold is formed.

  The position of the sheet in the second switchback path 35 is regulated by the stopper member 86 and guided to the nip position Np2 by the guide member 54, so that the sheet is not loosened by the second folding roller pair 101. As a result of the nip, there is no variation in the crease position. In addition, the space for forming a loop is narrowed when nipping by the second folding roller pair 101, and there is no fold position variation caused by the unstable loop shape for each sheet. Therefore, if the sheet size is the same and the folding specifications are the same, the sheet folded and conveyed by the first folding roller pair is always formed at the fixed folding position by the second folding roller pair 101.

  As shown in FIG. 15, the folded sheet sent to the secondary folding position (second nip position) Np2 is reliably folded by the additional folding roller 64 pressed against the second folding roller 49, and the third It is transferred to the path 36. Therefore, the folding process control unit 95a sends the folded sheet to the paper discharge path 37 or returns it to the first path 32 according to a preset sorting specification. The illustrated apparatus controls the path switching flapper 66 and guides it from the sheet discharge path 37 to the storage stacker 65 in the case of the three-fold or 1 / 3Z-fold of the letter fold specification that does not need to be bound by the post-processing apparatus C. .

  Further, in the three-fold mode such as bi-folding or 1 / 4Z-folding that requires post-processing such as filing or bookbinding and binding processing, the paper is transferred from the third path 36 to the first path 32, and the post-processing device 31 is transferred from the carry-out port 31. Send to C.

  In the apparatus of the present embodiment, the first fold roller 100 is guided to fold the sheet to form the primary fold, but when the primary fold is performed by providing a stopper member in the first switchback path 34 instead, Since the stopper member needs to be moved in the first switchback path 34 having the longest path length in accordance with the size of the sheet and the folding processing specifications, the structure becomes complicated and the apparatus becomes large. . However, by using the folding deflection member 53, this problem can be solved and the apparatus can be made compact with a simple configuration. Further, the folding deflecting member 53 abuts on the outer peripheral surface of the second folding roller 49 and guides the sheet fold to the nip position Np1 of the first folding roller pair 100, so that the sheet fold is reliably aligned with the first folding roller pair 100. So that the folding position can be reliably folded without causing variations in the fold position.

  Similar to the folding deflecting member 53, the guide member 54 is brought into contact with the circumferential surface of the folding roller 50 on the downstream side of the second folding roller pair 101 to guide the sheet fold to the nip position Np2 in the operating position. There is a conventional technology that has been achieved. However, when such a driven roller method is used for the second folding, the portion where the sheet formed by the primary folding is overlapped and conveyed by the driven roller and the folding roller 50 is conveyed to the peripheral surface of the driven roller. There is a difference in the conveyance amount between the touched sheet portion and the sheet portion touching the peripheral surface of the folding roller 50.

  Then, when the fold formed by the primary fold is nipped by the second folding roller pair 101, a fold is formed at a position different from the fold formed by the primary fold, and a double fold, so-called "" May occur. However, since the guide member 54 does not contribute to the conveyance of the sheet, a problem that a double fold is formed due to the difference in the conveyance amount of both folded sheet portions is prevented.

  Therefore, by providing the folding deflecting member 53 to form the primary fold and providing the stopper member 86 and the guide member 54 to form the secondary fold, a sheet folding apparatus with high folding accuracy can be provided.

[Folding operation in bi-fold mode]
In the folding operation described above, in the mode in which the sheet is folded in half, as shown in FIG. Then, the folding processing control unit 95a calculates the crease position by the crease position calculation unit 97 (St01). Therefore, in the folding processing control unit 95a, the sensor S1 detects the leading edge of the sheet (St03) in the bi-folding mode (St02).

  After the elapse of the sheet feeding time corresponding to the sheet length calculated by the fold position calculating means 97 from this detection signal (St04), the folding deflecting member 53 is moved from the standby position to the operating position (St05). This movement is controlled by the rotation of the shift motor Ms.

  In the process in which the elevating member 53c of the folding deflection member 53 moves to the operating position, the sheet in the first path 32 is distorted toward the first nip position Np1 with reference to the fold position as described with reference to FIG. When the driven roller 53a of the primary folding deflection member 53 comes into contact with the peripheral surface of the second folding roller 49, the sheet is squeezed and inserted from the fold position to the first nip position Np1.

  At this time, the folding processing control unit 95a sets the guide member 54 to the operating position after the expected time (St06) when the sheet fold is inserted into the first nip position Np1 based on the detection signal from the sensor S1 in the bi-fold mode. Move (St07). This estimated time is set to a time before the sheet fold position is inserted into the first nip position Np1 and reaches the side of the guide member 54 on the first folding roller pair 100 side. Accordingly, the leading edge of the folded sheet is guided by the side of the guide member 54 on the first folding roller pair 100 side along the circumferential surface of the second folding roller 49, and the leading edge of the folded sheet is in the second nip position. Even if it loops in a direction deviating from Np2, it is guided to the second nip position Np2.

  Then, the folding processing control unit 95a carries out the folded sheet carried out from the second nip position Np2 to the third path 36 to the first path 32 from the third path 36. Next, the folding processing control unit 95a prepares for the subsequent sheet processing with the guide member 54 positioned at the operating position (St08). In the figure, the folding deflecting member 53 is positioned at the standby position, and the guide member 54 that moves in a reciprocal position is positioned at the operating position. However, the sheet discharge sensor S3 ( It is also possible to configure the guide member 54 to move to the standby position by the detection signal of FIG.

[Folding operation in tri-fold mode]
In the mode in which the sheet is folded in three, as described with reference to FIGS. 12 to 14, the image forming apparatus A receives a mode instruction signal indicating whether or not to perform folding processing simultaneously with the paper discharge instruction signal. Then, the folding processing control unit 95a calculates the crease position by the crease position calculation unit 97 (St01). Therefore, in the folding process control unit 95a, in the tri-fold mode (St09), the sensor S1 detects the leading edge of the sheet (St10).

  The primary folding deflecting member 53 is moved from the standby position to the operating position after the passage of the sheet feeding time corresponding to the length of the sheet calculated by the fold position calculating means 97 from this detection signal (St11) (St12). This movement is controlled by the rotation of the shift motor Ms.

  In the process in which the folding deflection member 53 moves to the operating position, the sheet in the first path 32 is distorted toward the first nip position Np1 with reference to the fold position, as described with reference to FIG. When the driven roller 53a of the primary folding deflection member 53 comes into contact with the peripheral surface of the second folding roller 49, the sheet is squeezed and inserted from the fold position to the first nip position Np1. At this time, the folding process control unit 95a waits for the second sensor S2 to detect the leading edge of the sheet (St13) in the tri-fold mode.

  The folding processing control unit 95a moves the guide member 54 to the operating position after the expected time that the leading edge of the sheet reaches the stopper member 86 (St14) based on the signal that the second sensor S2 detects the leading edge of the sheet (St15). .

  As described above, the estimated time is the time from when the leading edge of the preset sheet is detected by the sensor S2 until it hits the stopper member 86 according to the sheet size and folding processing specification of the sheet. Thus, the sheet is guided by the guide member 54 to the second nip position Np2. Then, the sheet discharge sensor S3 (FIG. 16) detects the leading edge of the sheet, and the sheet is unloaded from the third path 36 to the first path 32 or unloaded from the sheet discharge path 37 to the storage stacker 65 according to the folding specification.

  Note that when the post-processing mode in which the sheet folding process is not performed is set by the mode setting unit 92 described above, the sheet carried into the first path 32 is directly sent to the carry-out port 31.

[Output path configuration]
The folded sheet folded in half as described above is fed from the second folding roller pair 101 to the third path 36. Then, it is further folded by the roller 64 that is in pressure contact with the second roller 49 and guided to the third path 36. The third path 36 joins the first path 32 as described above. Branching from the third path 36, a paper discharge path 37 is continuously provided via a path switching flapper 66, and this paper discharge path 37 guides the folded sheet to a storage stacker 65 disposed below the second path 33. To do. The paper discharge roller 67 is disposed in the paper discharge path 37.

  Therefore, sheets that are folded in letter specifications such as inner folds or 1 / 3Z folds that do not need to be transferred to the post-processing apparatus C are accommodated in the storage stacker 65 without being transferred to the carry-out port 31.

  Of the folded sheets sent to the third path 36, the sheet to be transferred to the post-processing apparatus C and to be post-processed is transferred toward the outlet 31 by the carry-out roller 62. In this case, the determination as to whether or not to perform post-processing is configured such that, for example, the post-processing conditions are set simultaneously with the image forming conditions on the aforementioned controller panel. Then, it is configured to be carried out to the storage stacker 65 or to be transferred to the post-processing apparatus C according to the set finishing conditions.

[Image forming apparatus]
The image forming apparatus A has the following configuration as shown in FIG. This apparatus sends a sheet from the sheet feeding unit 3 to the image forming unit 7, prints the sheet on the image forming unit 7, and then carries the sheet out from the main body discharge port 18.

  A plurality of sizes of sheets are stored in the sheet feeding cassettes 4 a and 4 b in the sheet feeding unit 3, and the designated sheets are separated one by one and fed to the image forming unit 7. The image forming unit 7 includes, for example, an electrostatic drum 8, a print head (laser light emitting device) 9 and a developing device 10 arranged around the electrostatic drum 8, a transfer charger 11, and a fixing device 12. An electrostatic latent image is formed by the light emitting device 9, toner is attached to the developing device 10, an image is transferred onto the sheet by the transfer charger 11, and heat fixing is performed by the fixing device 12.

  The sheets on which images are formed in this way are sequentially carried out from the main body discharge port 18. The circulation path 13 is a double-sided printing method in which a sheet printed on the front side from the fixing device 12 is turned upside down through the main body switchback path 14 and then fed again to the image forming unit 7 to be printed on the back side of the sheet. It is a route. The sheet printed on both sides in this way is turned upside down by the main body switchback path 14 and then carried out from the main body discharge port 18.

  The image reading unit 20 scans an original sheet set on the platen 21 with a scan unit 22 and electrically reads it with a photoelectric conversion element (not shown). The image data is digitally processed by an image processing unit, for example, and then transferred to the data storage unit 16 to send an image signal to the laser emitter 9. Further, the feeder device 25 feeds the document sheet stored in the stacker 26 to the platen 21.

  The image forming apparatus A having the above-described configuration is provided with a control unit (controller) (not shown), and image forming conditions such as sheet size designation, color / monochrome printing designation, print number designation, single-sided / double-sided printing designation, and enlargement from the controller panel 15. -Printout conditions such as reduced print designation are set.

  On the other hand, in the image forming apparatus A, image data read by the scan unit 22 or image data transferred from an external network is accumulated in the data storage unit 16, and the image data is transferred from the data storage unit 16 to the buffer memory 17. The data signal is sequentially transferred from the buffer memory 17 to the print head 9.

  From the controller panel 15, the post-processing conditions are also input and designated simultaneously with the image forming conditions. As the post-processing conditions, for example, “print-out mode”, “staple binding mode”, “sheet bundle folding mode”, or the like is selected. As the post-processing conditions, the folding specifications in the sheet folding apparatus B described above are set.

[Post-processing equipment]
The post-processing apparatus C has the following configuration as shown in FIG. This apparatus includes a sheet receiving port 69, a sheet discharge stacker 70, and a post-processing path 71 in an apparatus housing 68. The sheet receiving port 69 is connected to the carry-out port 31 of the above-described sheet folding apparatus B, and is configured to receive a sheet from the first conveyance path 32 or the third conveyance path 36.

  The post-processing path 71 is configured to guide the sheet from the sheet receiving port 69 to the paper discharge stacker 70, and a processing tray 72 is provided in this path. The sheet discharge port 73 accumulates sheets from the post-processing path 71 on the processing tray 72 disposed on the downstream side. The punch unit 74 is disposed in the post-processing path 71. A paper discharge roller 75 is disposed at the paper discharge port 73, and sheets from the sheet receiving port 69 are stacked on the processing tray 72.

  The processing tray 72 switches back the sheet from the post-processing path 71 (conveying direction reverse) and collects and aligns it on a rear end regulating member (not shown) provided on the tray. For this reason, a forward / reverse roller 75 for switching back the sheet from the sheet discharge port 73 is provided above the tray. Further, the processing tray 72 is connected to the paper discharge stacker 70, and the sheet from the paper discharge port 73 is supported by the paper discharge stacker 70 at the front end side and the processing tray 72 at the rear end side (bridge support).

  The processing tray 72 is provided with a stapler unit 77 for binding the sheet bundle positioned on the rear end regulating member. The aligning unit 73 aligns the sheets carried out on the processing tray in the widthwise alignment direction. The paddle rotator 79 is drivably coupled to the rotation shaft of the paper discharge roller 75 so as to transfer the sheet from the paper discharge roller 75 toward the trailing edge regulating member.

  The sheet bundle carry-out means 80 transfers the sheet bundle bound by the stapler unit 77 to the downstream paper discharge stacker 70. For this reason, the illustrated sheet bundle carrying-out means 80 includes a lever member 81 whose base end is pivotally supported so as to be swingable, and a sheet end engaging member 82.

  The sheet end engaging member 82 is mounted on the processing tray so as to reciprocate in the paper discharge direction along the processing tray 72, and is connected to the lever member 81. The drive motor Mm swings the lever member 81. The paper discharge stacker 70 is provided with an elevator mechanism (not shown) that moves up and down according to the amount of stacked sheets.

  As described above, the illustrated sheet folding apparatus according to the present invention conveys the first folding roller pair 100 that primarily folds the sheet to the conveyance path 33 that conveys the sheet and the second folding roller pair 101 that performs the second folding of the sheet. A stopper member 86 is provided in the second switchback path 35 of the conveyance path 33 in order along the direction, and the leading edge of the sheet that is primarily folded and conveyed at the nip position Np1 of the first folding roller pair. When the sheet abuts against the stopper member 86, the fold where the sheet folded first by the guide member 54 is guided to the nip position Np2 of the second folding roller pair 101 to form a second fold on the sheet.

  Accordingly, the sheet is nipped by the second folding roller pair 101 without being loosened by being pushed into the nip position Np by the guide member 54, so that there is no variation in the fold position, and the second folding roller pair. Since a space for forming a loop is narrowed when nipping at 101, there is no variation in the crease position caused by the unstable loop shape for each sheet. Therefore, if the sheet size is the same and the folding specifications are the same, the sheet folded and conveyed by the first folding roller pair can always form a crease by the second folding roller pair 101 at a fixed fold position. .

  The present invention relates to an apparatus that folds a sheet on which an image has been formed by an image forming apparatus such as a printing machine, a printer, or a copying machine at a predetermined folding position, and has industrial applicability.

A Image forming apparatus B Sheet folding device (folding processing unit)
Np1 first nip position (primary folding position)
Np2 2nd nip position (secondary folding position)
30 carry-in port 31 carry-out port 32 1st conveyance path | route (1st path | route)
33 Second transport path (second path)
41b first folding roller 49 second folding roller 50 third folding roller 53 folding deflecting member 53a driven roller 53b curved guide 54 guide member 100 first folding roller pair 101 second folding roller pair

Claims (11)

A sheet folding device for forming a fold in a sheet conveyed in a conveyance path,
A first folding roller located on the upstream side in the sheet conveying direction and a second folding roller located on the downstream side and rotating in contact with the outer peripheral surface of the first folding roller to form a primary fold on the sheet A first folding roller pair;
A second fold roller pair configured to form a second fold on the sheet on which the first fold is formed, the second fold roller and a third fold roller rotating in contact with an outer peripheral surface of the second fold roller; ,
A folding deflection member that guides the sheet fold to the nip position of the first folding roller pair in contact with the outer circumferential surface of the second folding roller when forming the primary folding;
A stopper member provided so as to abut against a leading end of the sheet on which the primary fold is formed;
And a guide member that guides the sheet to the nip position of the second folding roller pair when the leading edge of the sheet reaches the stopper member.   The guide member is movable between a standby position and an operating position, and is in the standby position when the sheet primarily folded by the first folding roller pair is conveyed to the stopper member. 2. The sheet folding apparatus according to claim 1, wherein when the leading edge of the sheet reaches the stopper member, the sheet folding apparatus moves to the operating position. The sheet folding apparatus according to claim 2 , wherein the guide member starts moving from the retracted position to the operating position immediately before the sheet contacts the stopper member.   The sheet folding apparatus according to any one of claims 1 to 3, wherein a predetermined position of the stopper member where a leading end of the sheet abuts moves according to a size and a folding position of the sheet.   2. The stopper member moves in a switchback path for forming the secondary fold formed along a direction substantially orthogonal to a conveyance direction of a sheet conveyed to the conveyance path. The sheet folding apparatus according to any one of 4 to 4.   6. The folding member according to claim 1, further comprising a driven roller in contact with an outer peripheral surface of the second folding roller at an operating position near the nip position of the sheet. A sheet folding apparatus according to claim 1.   The folding deflecting member is further disposed along a roller circumferential surface of the first folding roller, and a fold portion of the primary fold of the sheet is formed in a nip portion formed by the first folding roller and the second folding roller. The sheet folding apparatus according to any one of claims 1 to 6, further comprising a curved guide that guides the curved shape.   The guide member has a protrusion corresponding to the nip position so as to guide the sheet to the nip position for the second folding in the second folding roller pair, and each of both sides extended from the protrusion. The sheet folding device according to any one of claims 1 to 7, wherein the sheet folding device has a shape along outer peripheral surfaces of the second folding roller and the third folding roller that face each other. When the guide member is in the operating position, the second folding roller pair conveys the primary folded sheet to the second folding roller pair, and nips and conveys the sheet while maintaining the primary folding. The sheet folding apparatus according to claim 2 , wherein the sheet folding apparatus is provided.   The sheet folding apparatus according to claim 1, wherein the second folding roller is configured by a roller having an outer diameter larger than that of the first folding roller or the third folding roller. An image forming apparatus for sequentially forming images on sheets;
A sheet folding apparatus for folding sheets from the image forming apparatus;
And consists of
An image forming system comprising: the sheet folding apparatus having the configuration according to claim 1.

Images