JP2011131974A - Sheet feeding device, sheet folding device equipped with the same, and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeding device capable of surely correcting the skew with a simple structure in feeding a sheet into a sheet folding position. <P>SOLUTION: A first folding roll 41b for folding the sheet is arranged in a carry-in path 32 for feeding the sheet toward the folding position, and a pinch roller 41a is arranged to come in pressure contact with and to separate from the roll. A second folding roll 49 facing the first folding roll, and a folding guide member 53 guiding the fold position of the sheet to a pressure contact part of the folding roll pair, are arranged downstream of the pinch roller. A resist area Ar for curving and deforming the sheet is arranged upstream of the pinch roller 41a. The folding guide member is provided with a regulating surface 53S butt-locking the sheet tip, and the folding guide member is constituted to move between a standby position outside the path and an operating position inside the path with respect to the carry-in path. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sheet feeding apparatus in a sheet folding apparatus that folds an image-formed sheet, for example, and an improvement in a sheet feeding mechanism that corrects a skew of a leading edge of a sheet fed from a carry-in port and feeds the sheet to a folding processing position. About.

  In general, this type of sheet feeding apparatus is provided with a skew correction mechanism that corrects the skew of the leading edge of the sheet sent to the carry-in entrance and feeds it to the processing position. As this skew correction mechanism, there is known a mechanism (registration roller mechanism) for aligning the leading ends by retracting a sheet from the upstream side and bending it in a loop shape with the pair of rollers in pressure contact with each other being stopped. In addition to this, a gate stopper is provided on the downstream side of the roller pair, the sheet tip is abutted against the stopper surface in a state where the roller pair is separated and curved in a loop shape, and then the roller pair is pressed and rotated to align the tips. (Gate stopper mechanism) is known.

  The present invention relates to the latter gate stopper mechanism. Conventionally, a pair of rollers is arranged in a path so as to be able to be pressed and separated, and a stopper member is disposed downstream of the roller pair from a standby position outside the path to an operating position in the path. A stopper mechanism that moves its position is widely known. For example, Patent Document 1 discloses a mechanism in which a rotation stopper provided with a locking claw is disposed on the downstream side of a roller pair, and the leading end of the sheet is abutted and locked by the locking claw. Similarly, in Patent Document 2, a paddle-shaped stopper is provided on the downstream side of the roller pair to lock the leading edge of the sheet.

  Conventionally, when such a gate stopper mechanism is employed in an image forming apparatus such as a printing machine, a printer device, or a copying machine, the gate stopper mechanism is provided in the paper feed path on the upstream side of the image forming unit (processing unit). It is arranged. The sheet feeding timing by the gate stopper mechanism is to feed the roller pair by moving the roller pair from the separated position to the press-contacting position by a sheet feeding instruction signal from the processing unit.

JP-A 61-27853 JP 7-291487 A

  As described above, a skew correction mechanism that arranges a gate stopper on the upstream side of the processing position in order to feed the sheet to the processing position in the apparatus in a correct posture is widely known in Patent Document 1 and Patent Document 2 described above. . However, conventionally, a roller pair, a gate stopper, and a resist area are arranged upstream of the processing position such as paper folding. For this reason, since the apparatus is arranged in the order of the skew correction mechanism section and the sheet processing section on the downstream side thereof, the apparatus is large in size and has a large number of parts, which causes an increase in cost.

  For example, in a sheet folding apparatus that folds a sheet sent from an image forming apparatus into two, three, etc., a pair of conveyance rollers and a gate stopper for correcting skew are provided in the sheet carry-in path, and the sheet is fed. At this timing, the roller pair is pressed and separated and the stopper is actuated, and a folding mechanism such as a sheet folding roll is arranged downstream of the mechanism. For this reason, there is a known problem that the apparatus is large and the control mechanism is complicated.

  Accordingly, the present inventor has come up with the idea of correcting the skew of the front end of the sheet with a pair of folding rolls and a folding guide member (for example, a folding blade) that guides the folding line of the sheet to the pressure contact portion. This paid attention to the simplification of the mechanism for correcting the skew, and the miniaturization and cost reduction of the apparatus.

  An object of the present invention is to provide a sheet feeding apparatus capable of reliably correcting the skew with a simple structure when feeding a sheet to a sheet folding processing position. Furthermore, the present invention is capable of correcting the skew of the sheet fed out from the carry-in entrance while the roller pair for feeding the sheet to the processing position is rotated for the processing operation of the preceding sheet. An object of the present invention is to provide a sheet feeding apparatus that enables efficient sheet processing.

  In order to achieve the above object, according to the present invention, a first folding roll for folding a sheet is disposed in a carry-in path for feeding the sheet toward a folding processing position, and a pinch roller is disposed on the roll so as to be capable of being pressed and separated. To do. A second fold roll facing the first fold roll and a fold guide member for guiding the fold position of the sheet are disposed on the pressure contact portion between the pair of fold rolls on the downstream side of the pinch roller. At the same time, a resist area for bending and deforming the sheet is arranged on the upstream side of the pinch roller.

  The folding guide member is provided with a regulating surface for abutting and locking the leading end of the sheet, and the folding guide member is moved relative to the carry-in path between a standby position outside the path and an operating position within the path. It is said. With this configuration, skew correction at the front end of the sheet is shared by the pair of folding rolls and the folding guide member. Therefore, it is possible to make the apparatus compact and compact and to reduce the manufacturing cost.

  More specifically, the configuration is a sheet feeding device that aligns the leading edge of a sheet sent to the carry-in path (32) and transfers the sheet to a predetermined folding processing position (Np1, Np2). A carry-in path for feeding to the position, a first and second folding roll pair (41b, 49) disposed in the carry-in path and for folding the sheet, and a pair disposed in the carry-in path so as to be capable of being pressed and separated. A pair of conveying rollers (41a, 41b), a registration area (Ar) arranged on the upstream side of the conveying roller pair to bend and deform the sheet, and a gate stopper means arranged on the downstream side of the conveying roller pair to abut and regulate the leading edge of the sheet (42), roller raising / lowering means (operation solenoid 44 described later) for pressing and separating the conveying roller pair, and control means 95 for controlling the roller raising / lowering means.

  The gate stopper means includes a folding guide member (53) for guiding a fold position of the sheet fed from the carry-in path to the pressure contact portion of the pair of folding rolls, and a sheet leading edge regulating surface (53S) formed on the folding guide member. Shift means (MS) that moves between a standby position (Pw) where the folding guide member is retracted from the carry-in path and an operating position (Ps) that guides the sheet to the pressure contact portion (Np1) of the pair of folding rolls; Consists of.

  Accordingly, the control means (95) is configured to bend the sheet in the registration area by separating the conveying roller pair in a state where the folding guide member is positioned in the carry-in path.

  The present invention provides a gate stopper for correcting a skew by temporarily curving the leading edge of a sheet on a path, a first folding roll that folds the sheet, and a fold position of the sheet by pressing the first and second folding rolls. Since it is composed of a folding guide member that guides to the part, the following effects are produced.

  When the sheet sent to the carry-in path is aligned at the leading edge and transferred to the folding processing position, the sheet leading edge is skew-corrected by the eleventh folding roll to be folded and the folding guide member that guides the folding of the sheet to the folding position. Thus, the apparatus, in particular, the paper feeding unit can be configured in a compact and compact manner.

  At the same time, since the skew at the front end of the sheet is corrected by the folding mechanism (folding roll and folding guide), it is possible to reduce the number of parts and the apparatus failure. Therefore, the cost can be reduced by simplifying the mechanism for correcting the skew.

  Further, according to the present invention, the skew of the subsequent sheet can be corrected at a high speed while the pair of folding rollers is rotated for folding the preceding sheet by separating the pinch roller from the first folding roll. Efficient sheet folding processing is possible.

1 is an explanatory diagram of an overall configuration of an image forming system according to the present invention. The principal part expansion explanatory drawing of the post-processing apparatus in the system of FIG. FIG. 2 is an explanatory diagram of an overall configuration of a sheet folding device in the system of FIG. 1. FIG. 4 is an enlarged explanatory view of a main part in the sheet folding apparatus of FIG. 3. Explanatory drawing of the layout structure of the folding roll of FIG. FIG. 4 is an explanatory diagram of a layout configuration of a registration mechanism and a secondary folding deflecting unit in the sheet folding apparatus of FIG. 3. FIGS. 7A and 7B are explanatory views showing the operation of the registration mechanism in FIG. 6A, in which the gate stopper is in the operating position, FIG. 6B is in the middle of the movement of the gate stopper to the retracted position, and FIG. Shows the state. FIGS. 4A and 4B are diagrams illustrating a state of a sheet folding operation in the apparatus of FIG. 3, in which FIG. 3A illustrates a state where a sheet is subjected to registration correction, and FIG. FIGS. 4A and 4B are diagrams illustrating a state of a sheet folding operation in the apparatus of FIG. 3, in which FIG. 3A illustrates a state in which the sheet is primarily folded at a first nip portion, and FIG. Indicates the state. FIGS. 4A and 4B are diagrams illustrating a state of a sheet folding operation in the apparatus of FIG. 3, in which FIG. 3A illustrates a state in which the sheet is folded from the second switchback path at the second nip portion, and FIG. Is shown in a state of being carried out in the paper discharge direction. FIG. 4 is an explanatory diagram of a state of sheet folding operation, (a) is an explanatory diagram showing the action of a secondary folding deflection guide that guides the leading edge of the sheet to the second nip portion when the two-folding mode is executed, and (b) is a folding process. The flowchart which shows operation | movement. It is explanatory drawing of the sheet folding specification in the sheet folding apparatus of this invention, (a) is a mode which folds a sheet | seat inside three at 1/3 position, (b) is a mode which Z-folds a sheet | seat at 1/3 position. (C) shows a mode in which the sheet is Z-folded at a 1/4 position. Explanatory drawing of the drive mechanism in the apparatus of FIG. Explanatory drawing of embodiment different from FIG. 3 of a folding deflection | deviation guide. Explanatory drawing of the control structure in the system of FIG.

  Hereinafter, the present invention will be described in detail based on illustrated embodiments. 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 is configured as a printer, a copier, a printer, or the like that sequentially forms 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. Further, 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, punching, stamping, and binding 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 configuration will be described later)

  Therefore, the sheet folding apparatus B is shown in FIG. 3 as a whole, but the apparatus housing 29 is provided with a carry-in port 30 and a carry-out port 31, and the carry-in port 30 is connected to the main body discharge port 18 of the image forming apparatus A on the upstream side. In addition, the carry-out port 31 is arranged at a position continuous with the sheet receiving port 69 of the downstream post-processing apparatus C. As shown in FIG. 3, 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. The 2nd conveyance path | route 33 carried out to the carry-out exit 31 is arrange | positioned. In this path, a “conveying mechanism” for transferring the sheet in a predetermined direction and a “folding mechanism” for folding the sheet are arranged.

[Route configuration]
As shown in FIG. 3, 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.

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

  The second path 33 intersects with the first path 32 and includes a path end portion that guides the sheet above the first path 32 and a path end portion that guides the sheet below the first path 32. . In the embodiment of FIG. 3, the first switchback path 34 that guides the leading edge of the sheet to the first nip portion 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.

  As described above, the first path 32 and the second path 33 are arranged so as to intersect with each other, but the first switchback path 34 for guiding the sheet to the folding position (first nip portion) Np1 is provided below the first path 32. In addition, the second switchback path 35 for guiding the folded sheet to the downstream side may be disposed above the first 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 vertical first path 32, and the second switchback path 35 is on the left side of the first path 32. (Or right side). In the embodiment shown in FIG. 3, the second switchback path 35 is configured to reverse the sheet feeding direction so as to guide the folded sheet to the second nip portion Np2 in order to perform the secondary folding of the sheet. However, when the sheet is not folded second, it is possible to use a straight path.

  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 portion Np2 for secondary folding of the sheet 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 configured as described above is configured as a circularly curved path having a curvature R1 as shown in FIG. 3, and the second switchback path 35 has a curvature R2 shown in FIG. It has a circularly curved path. Further, the paper discharge path 37 connected to the third path 36 is also configured as a circularly curved path having a curvature R3.

  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 portion) 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 portion 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 portion Np2 to the storage stacker 65 is configured to satisfy L3 <L2 <L1. As a result, when the primary folding position (first nip portion) Np1 is arranged in the vicinity of the first path 32, the path length is set to L3 <L2 <L1, resulting in a compact path configuration.

  The first switchback path 34 is an arcuate path having a curvature R1, the second switchback path 35 is a curvature R2, and the paper discharge path 37 is an arcuate path having a curvature R3. The curvature is set so that the first switchback path 34 is larger than the second switchback path 35 (curvature R1> curvature R2).

  Therefore, the frictional resistance of the sheet passing through the first switchback path 34 having a large curvature is smaller than the frictional resistance of the sheet passing through the second switchback path 35 having a small curvature. Further, the curvature R3 of the sheet discharge path 37 for guiding the folded sheet to the storage stacker 65 is set such that curvature R3 <curvature R2 <curvature R1. Accordingly, the frictional resistance for the sheet to pass through each path is as follows: first switchback path 34 <second switchback path 35 <discharge path 37.

  On the other hand, the strength of the sheet is the lowest in the single sheet passing through the first switchback path 34, the secondary folded sheet passing through the second switchback path 35 is intermediate, and the secondary sheet passing through the paper discharge path 37. The folded sheet is the highest. Therefore, setting the above conditions according to the strength of the waist of the sheet conveying the path minimizes the space occupied by the path without causing sheet jam.

  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. A paper discharge path 37 from the second switchback path 35 to the storage stacker 65 is formed in an inverted S-curve. A storage stacker 65 is disposed below the second switchback path 35 and connected by a 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 is concentrated.

[Folding processing means]
A folding processing means 48 for folding the sheet is disposed in the second path 33 described above. The folding processing means 48 includes folding roll pairs 41b, 49, and 50 for folding the sheet in half or in three, and folding deflecting means 53 and 54 for guiding the sheet fold to the nip portion Np1 (Np2). When the sheet is folded in two, it is composed of two roll pairs and one folding deflecting means, and when the sheet is folded in three, it is composed of three or four roll pairs and two folding deflecting means.

  In the apparatus of FIG. 3, the folding roll pair includes a first roll 41b and a second roll forming a first nip portion Np1 and a second nip portion Np2 because of a three-fold specification relationship in which the sheet is folded first and then secondarily. 49 and a third roll 50. The folding deflection means includes a primary folding deflection guide 53 and a secondary folding deflection guide 54. 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 portion Np2 to the first path 32 is connected.

  In these routes, as shown in FIG. 3, the first route 32 and the second route 33 intersect at CP1, and the third route 36 and the first route 32 intersect 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 apparatus shown in the figure is characterized in that the above-mentioned three-way guide is composed of the following one 63. In the first route 32, route switching means 63 is arranged at the intersection CP1 with the second route 33. As shown in FIG. 3, the path switching means 63 is pivotally supported so that the base end portion 63x can swing on a device frame outside the path (the support shaft 62x of the carry-out roller 62a is shown). Guide surfaces 63a and 63b are formed.

  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 posture of the broken line in FIG. 3 to the carry-out port 31 without being carried into the second path 33.

  In short, the second path 33 intersects the first path 32 at the first intersection CP1 so as to carry in the sheet from the carry-in entrance 30, and the third path 36 directs the folding processed sheet toward the carry-out exit 31. Crossing is made at the second intersection CP2 so as to carry out, and a path switching means 63 for switching the sheet conveyance direction is arranged at the first intersection CP1 and the second intersection CP2.

  The path switching means 63 is composed of a path switching member (plate-shaped guide piece) that advances and retreats in the first path. The front guide surface 63a guides the sheet from the first path 32 to the second path 33. The sheet from the third path 36 is guided to the first path 32 by the back guide surface 63b.

  The path switching member 63 has a first guide posture (a broken line in FIG. 3) for directly sending a sheet from the carry-in entrance 30 to the carry-out port 31 through the first path 32, and a sheet fed from the carry-in entrance 30 to the first path 32. Drive means (actuation solenoid; not shown) that changes the posture between the second guide posture (solid line in FIG. 3) that guides the second route 33 and guides the sheet sent from the third route 36 to the first route 32. Is provided. That is, the illustrated path switching member 63 is formed of a plate-like piece that swings about the support shaft 63x, and an operating solenoid and a return spring are connected to a base end portion thereof.

  Thus, the path switching member 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 34 to the first nip portion 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 roll configuration]
In the second path 33, the first roll 41b, the second roll 49, and the third roll 50 are arranged so as to be in pressure contact with each other. A first nip portion (primary folding position) Np1 for primary folding of the sheet is formed at the pressure contact between the first roll 41b and the second roll 49, and the sheet is fed at the pressure contact between the second roll 49 and the third roll 50. A second nip portion (secondary folding position) Np2 to be folded next is formed.

  In particular, in the illustrated apparatus, the circumferential surface of the first roll 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 roll. As a result, the sheet in the first path 32 is conveyed by the first roll 41b and the pinch roller 41a, and there is no need to provide a special conveying member and its drive mechanism in the first path 32. The first roll 41b and the pinch roller 41a constitute a conveying roller pair.

  In addition, the first, second and third roll diameters are set such that the second roll diameter is 30 mm at the maximum, the first and third roll diameters are 20 mm, and the second roll 49 located at the center is the maximum diameter ( For example, the reason will be described later. Further, an additional folding roller (drive roller) 64 is pressed against the second roll 49 on the downstream side of the pressure contact with the third roll 50.

[Configuration of folding deflection means]
As described above, the folding roll constituted by three rolls (41b, 49, 50) has a primary folding deflection guide 53 at the first nip portion Np1 and a secondary folding deflection guide 54 at the second nip portion Np2. Are arranged to guide the sheet folds to the respective nip portions (pressure contact points). In the apparatus of FIG. 3, the primary folding deflection guide 53 and the secondary folding deflection guide 54 have the same structure, so the structure of the primary folding deflection guide 53 will be described. As shown in FIGS. 4 and 5, the folding deflection guide 53 includes a driven roller 53a, a guide surface 53b, an elevating member 53c, and a regulating surface 53S described later.

  As shown in FIG. 5, the first nip portion Np1 for first folding the sheet is composed of a first roll 41b and a second roll 49, and the first roll 41b is arranged on the upstream side and the second roll 49 is arranged on the downstream side. Yes. Therefore, the driven roller 53 a is disposed at a position in contact with the peripheral surface of the second roll 49. And the guide surface 53b is provided with the curved guide surface along the surrounding surface of the 1st roll 41b located in an upstream.

  The driven roller 53a and the guide surface 53b are supported by an elevating member 53c. The elevating member 53c is constituted by a bracket member (frame member) having an appropriate shape, and the driven roller 53a is rotatably supported by the elevating member 53c, and the guide surface 53b is fixed at the same time. The elevating member 53c is supported by a guide rail provided on the apparatus frame, and the standby position where the driven roller 53a is in contact with the peripheral surface of the second roll 49 (the broken line position in FIG. 4) and retracted out of the second path 33. It is configured to move up and down between positions (solid line positions in FIG. 4). A shift means 56, which will be described later, is connected to the elevating member 53c and moves the driven roller 53a and the guide surface 53b between the operating position and the standby position.

  Therefore, the driven roller 53a and the guide surface 53b described above are set in the positional relationship shown in FIG. In the first nip portion Np1, the sheet is fed from the carry-in port 30 by the first roll 41b and the pinch roller 41a pressed against the first roll 41b. The pressure contact of the pinch roller 41a is indicated by p1 in FIG.

  The driven roller 53a is in pressure contact with the second roll 49 located on the downstream side, and the pressure contact is indicated by p2 in FIG. Therefore, when guiding the fold position of the sheet to the first nip portion Np1, the upstream side of the sheet is given a conveying force by the pressure contact p1, and is guided to the first nip portion Np1 along the peripheral surface of the first roll 41b. . Further, the downstream side of the sheet is given a conveying force by the pressure contact p <b> 2 and is guided to the first nip portion Np <b> 1 along the peripheral surface of the second roll 49.

  At this time, the conveyance length Lx between the pressure contact p1 and the first nip portion Np1 and the conveyance length Ly between the pressure contact p2 and the first nip portion Np1 are set to Lx> Ly. The position of the driven roller 53a is set according to such a conveyance length relationship. And the above-mentioned guide surface 53b forms the curved guide surface of the curved shape along the surrounding surface of the 1st roll 41b with large conveyance length.

  In other words, conventionally, a guide member that guides the fold of the sheet to the fold nip portion (Np1, Np2) is provided separately from the sheet steering means, so that the position shift or wrinkle is generated at the fold at the timing shift acting on the sheet. It was. In order to solve this, the illustrated apparatus sets the conveyance length Lx of the first roll 41b on the upstream side of the sheet toward the first nip portion Np1 and the conveyance length Ly of the second roll 49 on the downstream side to [Lx> Ly], and at the same time, the curved guide surface of the guide surface 53b is configured so that the sheet runs along the peripheral surface of the first roll 41b having a long conveying length, and the driven roller 53a and the guide surface 53b are simultaneously moved from the standby position. The position has been moved to the operating position.

  With this configuration, the sheet fold can be accurately guided to the first nip portion Np1. As is apparent from FIG. 5, in order to set the transport length to [Lx> Ly], it is necessary to configure the roll diameter of the driven roller 53a to be smaller than the roll diameter of the first roll 41b located on the upstream side. .

  Similarly, the secondary folding deflection guide 54 applies a conveying force to the sheet at the first nip portion Np1 of the second roll 49 located on the upstream side, and the conveyance length Lx from this point to the second nip portion Np2 is applied. Thus, the pressure contact p3 between the driven roller 54a and the third roll 50 located on the downstream side and the conveyance length Ly between the second nip portion Np2 are set to [Lx> Ly].

  The curved guide surface of the guide member 54b is configured so that the sheet is placed along the peripheral surface of the second roll 49 having a long conveying length. The secondary folding deflection guide 54 and the previous primary folding deflection guide 53 move reciprocally so that when one is in the operating position, the other is in the standby position. This is because the elevating member 53c of the primary folding deflection guide 53 and the elevating member 54c of the secondary folding deflection guide 54 are moved up and down by the same driving means (described later).

[Drive mechanism]
Next, the drive mechanism of the first path 32, the second path 33, and the folding processing means 48 will be described. As shown in FIG. 4, the first path 32 is provided with a pair of carry-in rollers (first transport means) 40 at the carry-in entrance 30 and a pinch roller (second transport means) 41 a on the downstream side. A carry-out roller pair 62 is provided.

  The carry-in roller pair 40 includes a pair of rollers 40a and 40b, and a conveyance motor Mf described later is connected to one of the rollers 40b. Similarly, the carry-out roller pair 62 includes a pair of rollers 62a and 62b, and a conveyance motor Mf is connected to one of the rollers 62b. Further, the pinch roller 41a is arranged to rotate following the first roll 41b, and this roll 41b is connected to the transport motor Mf.

  As shown in FIG. 3, the first switchback path 34 and the second switchback path 35 constituting the second path 33 are provided with conveying means such as a roller and a belt for applying a conveying force to the sheet. Not. Therefore, the first switchback path 34 is provided with a first roll 41b and a pinch roller 41a that is pressed against the first roll 41, and a conveying force in the loading direction for loading the sheet into the path is provided, and a driven roller 53a that is pressed against the second roll 49 is provided. A conveying force for transferring the sheet from the path to the primary folding position Np1 is applied.

  Further, the second switchback path 35 is given a conveying force for carrying the sheet into the path at the nip portion Np1 between the first roll 41b and the second roll 49, and the secondary folding position (second nip portion) from this path. The conveying force for feeding the sheet to Np2 is applied by the driven roller 54a of the secondary folding deflection guide 54. As shown in FIG. 4, the third path 36 connected to the second switchback path 35 is provided with a conveying force by which the additional folding roller 64 in pressure contact with the second roll 49 carries the folded sheet toward the carry-out roller pair 62. is doing. 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. .

  Therefore, as shown in FIG. 13, the pair of carry-in rollers 40 and the pair of carry-out rollers 62 in the first path 32, the first roll 41 b, the second roll 49, the third roll 50, and the paper discharge path 37 of the folding processing unit 48. The drive of the conveyance motor Mf is transmitted to the paper discharge roller 67. That is, the drive of the conveyance motor Mf is transmitted to the first roll 41b by belt transmission, and the first roll 41b, the second roll 49, and the third roll 50 are driven and transmitted by gears or the like so as to have the same peripheral speed.

  The elevating member 53c of the primary folding deflection guide 53 and the elevating member 54c of the secondary folding deflection guide 54 are connected to a shift motor Ms so as to move reciprocally between the standby position and the operating position. This shift motor Ms is constituted by a forward / reverse motor, and pinions 53p, 54p are engaged with racks 53r, 54r formed on the first elevating member 53c and the second elevating member 54c. When the shift motor Ms rotates forward, the first elevating member 53c moves from the standby position to the operating position, and when it rotates in the reverse direction, the second elevating member 54c moves from the standby position to the operating position. . Therefore, the shift motor Ms, the racks 53r, 54r, and the pinions 53p, 54p constitute a shift means 56 (see FIG. 13) for moving the lifting members 53c, 54c up and down.

[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. A second sensor S2 for detecting the edge of the sheet carried into the second switchback path 35 is disposed. The first sensor S1 is disposed on the upstream side of the primary folding deflection guide 53 on the downstream side of the first roll 41b and the pinch roller 41a. The first sensor S1 and the second sensor 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 the folding specification described later.

[Modification of drive mechanism]
In the drive mechanism described above, the roller 40b, the roller 62b, and the first roll 41b are connected to the transport motor Mf and the drive is transmitted by the same motor. However, the drive mechanism transmits the roller 40b and the roller 62b to the transport motor Mf. It is also possible to connect to another motor. The embodiment will be described in detail below.

  One roller 40b of the carry-in roller pair 40 provided in the first path 32 and one roller 62b of the carry-out roller pair 62 are connected to a drive motor M (not shown), and the first roll 41b is connected to the carry motor Mf. To do. When the sheet is sent to the carry-in entrance 30, the drive motor M is driven to carry the sheet into the first path. At this time, the first roll 41b connected to the transport motor Mf does not rotate because the motor Mf is stopped, and the pinch roller 41a is retracted to a position separated from the first roll 41b.

  Then, the sheet leading edge sent to the first path 32 abuts against the sheet leading edge regulating surface 53S of the primary folding deflection guide 53 and is locked to correct the skew. After the skew of the sheet front end is corrected, the pinch roller 41a is brought into pressure contact with the first roller 41b to nip the front end of the sheet, and the primary folding deflection guide 53 is returned to the standby position. Then, the conveyance motor Mf is driven, and the sheet is conveyed downstream of the first path 32. By providing two motors in this way, skew correction can be performed more reliably.

[Registration mechanism]
In the first path 32, a registration mechanism for correcting the skew of the front end of the sheet is disposed. This registration mechanism will be described with reference to FIGS. In the first path 32, a pair of carry-in rollers 40 a and 40 b, a first roll 41 b, and a primary folding deflection guide 53 are arranged in this order from the carry-in entrance 30 toward the downstream side. A pinch roller 41a is disposed on the first roll 41b so as to be capable of being pressed and separated. On the downstream side, the first sensor S1 for detecting the leading edge of the sheet and the primary folding deflection guide 53 are arranged.

  The pinch roller 41a is disposed so as to be capable of being pressed and separated from the circumferential surface facing the first path 32 of the first roll 41b. The pinch roller 41a is made of polyacetal (POM) and is made of a material having a body friction coefficient from the first roll 41b made of a rubber material. The pinch roller 41a is supported by a bracket (elevating arm member) 43 that is rotatably supported on a device frame (not shown) by a support shaft 43x.

  As shown in FIG. 6, the pinch roller 41a moves away from the first roll 41b when the bracket 43 rotates clockwise by a predetermined angle around the support shaft 43x, and the pinch roller 41a presses against the first roll 41b when rotated counterclockwise. Is configured to do. The roller diameter of the first roll 41b is set larger than the roller diameter of the pinch roller 41a. And this large diameter 1st roll 41b is arrange | positioned under the action direction of gravity.

  A biasing spring 45 is connected to the bracket 43 in the counterclockwise direction (pressure contact direction), and an operating solenoid (roller lifting / lowering means; the same applies hereinafter) 44 in the clockwise direction (separating direction). Accordingly, in a normal state, the pinch roller 41a is pressed against the first roll 41b by the urging spring 45, and when the operation solenoid 44 is energized, the pinch roller 41a is separated from the first roll 41b.

  A registration area Ar is provided between the pair of carry-in rollers 40a and 40b on the upstream side of the above-described pinch roller 41a. The resist area Ar is formed by a space in which the paper guide 32g constituting the first path 32 is bent as shown in FIG. 6 to deform the sheet into a loop shape.

  The first sensor S1 and the primary folding deflection guide 53 are disposed downstream of the pinch roller 41a. The first sensor S1 detects the leading edge of the sheet toward the primary folding deflection guide 53 located on the downstream side, and transfers a detection signal to the control means 95 described later. On the other hand, in the primary folding deflection guide 53, a sheet leading end regulating surface 53S is formed on the elevating member 53c, and the sheet leading end regulating surface 53S constitutes a gate stopper means. As will be described later, the elevating member 53c is configured to move up and down between a position where the front end of the sheet in the first path is regulated by the shift motor Ms and a retracted position outside the path. The primary folding deflection guide 53 is provided with the driven roller 53a and the guide surface 53b.

  Thus, the gate stopper means 42 is provided with the primary folding deflection guide 53 having the sheet leading edge regulating surface 53S that abuts and latches the sheet leading edge, the locking position within the first path, and the standby outside the path. It is comprised by the shift motor Ms which moves a position between positions.

  Therefore, the control means 95 described later carries the sheet sent to the carry-in entrance 30 into the apparatus by the carry-in roller pair 40a, 40b. The pinch roller 41a feeds the sheet to the first sensor S1 on the downstream side at a position where the pinch roller 41a is in pressure contact with the first roll 41b. When the arrival of the leading edge of the sheet is detected by the first sensor S1, the control means 95 energizes the operating solenoid 44 to retract the pinch roller 41a to a position separated from the first roll 41b. At the same time, the control means 95 deflects the posture of the primary folding deflection guide 53 from the standby position (the state shown in FIG. 7A) to the locking position (the state shown in FIG. 7B).

  Then, the leading edge of the sheet sent into the first path 32 is abutted and locked against the sheet leading edge regulating surface 53S of the primary folding deflection guide 53, and is bent and deformed to the state of FIG. At this time, the sheet leading edge regulating surface 53S is formed in a planar shape orthogonal to the first path 32 so as to align the leading edge of the sheet. Therefore, the sheet is curved and deformed along the regulating surface 53S, and the skew is corrected. It becomes.

  After correcting the skew of the sheet leading edge in this way, the control means 95 returns the pinch roller 41a from the separated position to the pressure contacting position where it is pressed against the first roll 41b, and nips the sheet leading edge. At the same time, the control means 95 returns the primary folding deflection guide 53 to the standby position. Then, the sheet is conveyed to the downstream side of the first path 32.

[Second Embodiment of Folding Processing Unit]
The folding processing means 48 described with reference to FIGS. 3 to 7 includes the primary folding deflecting means 53 and the secondary folding deflecting means 54 mounted on the driven rollers 53a and 54a and the guide surfaces 53b and 54b. In this example, the lift members 53c and 54c are connected to the shift motor Ms by racks 53r and 54r and pinions 53p and 54p. This folding mechanism can also be configured as shown in FIG.

  In the embodiment shown in FIG. 14, the secondary folding deflection guide 86, the driven roller 86a, and the guide member 87 are individually mounted on the apparatus frame, and the guide member 87 waits in conjunction with the raising and lowering operation of the driven roller 86a. It is configured to move up and down between the position and the operating position.

  The secondary folding deflecting means 86 shown in FIG. 14 includes an elevating member 86b, a driven roller 86a mounted on the elevating member 86b, and a guide member 87 arranged separately from the elevating member 86b. The elevating member 86b is supported on a guide rail (not shown) of the apparatus frame so as to be reciprocally movable as in the above-described embodiment. A follower roller 86a is rotatably supported by the elevating member 86b.

  On the other hand, the guide member 87 is supported by the drive shaft 41bx of the first roll 41b so that the bracket 87b can swing, and a curved guide surface 87a along the peripheral surface of the second roll 49 is formed at the tip. The guide member 87 is provided with a return spring 88 that urges the curved guide surface 87a toward the standby position where the curved guide surface 87a is retracted from the second switchback path 35 around the support shaft of the bracket 87b.

  Therefore, the guide member 87 is engaged so that the curved guide surface 87a is moved from the standby position to the operating position in conjunction with the movement of the driven roller 86a from the standby position to the operating position. Therefore, the secondary folding deflecting means 86 configured in this manner reciprocates between the standby position and the operating position in the same manner as described above.

  Further, the apparatus shown in FIG. 14 is driven by lifting levers 89 and 90 when the lifting member 85b of the primary folding deflecting means 85 and the lifting member 86b of the secondary folding deflecting means 86 are moved from the standby position to the operating position. The drive mechanism is configured to do this. That is, the primary folding lift lever 89 and the secondary folding lift lever 90 are supported so that their base ends are swung by a rotation shaft, and a shift motor Ms is connected to the rotation shaft.

  And the front-end | tip part of the raising / lowering levers 89 and 90 is arrange | positioned so that it may engage with the raising / lowering members 85b and 86b. The elevating members 85b and 86b are provided with urging springs (not shown) and always urge the driven rollers 85a and 86a toward the operating position.

  In the apparatus of FIG. 14, the first sensor S1 disposed in the first path 32 is configured by a lever sensor as shown. Other configurations are the same as those of the apparatus shown in FIGS.

[Folding specification]
Next, the sheet folding method by the folding processing means 48 will be described with reference to FIG. A normal image-formed sheet may be folded in two or three with a margin for filing finish, or may be folded in two or three for letter finishing. In addition, when folding in three, there are cases where Z-folding and inner three-folding are performed. In FIG. 12, (a) shows an inner trifold, (b) shows a 1 / 3Z fold, and (c) shows a 1 / 4Z fold.

  In the case of folding in half, the sheet sent to the second path 33 is moved to the 1/2 position of the sheet size by the first and second rolls 41b and 49, or the 1/2 position is left at the sheet edge portion. Fold together (primary fold).

  In the case of three-fold folding, the sheet sent to the second path 33 is moved to the 1/3 position of the sheet size by the first second rolls 41b and 49, or the 1/3 position leaving a binding margin at the end of the sheet. Fold together (primary fold). The folded sheet is folded by the second third rolls 49 and 50 at the 1/3 position (secondary folding) and sent to the third path 36.

  In the case of three-fold folding, as shown in FIG. 12A, when the inner three-fold is performed, the sheet fed to the second path 33 is fed by the first second rolls 41b and 49 to the sheet rear end side 1/3. The positions are folded, and then the 1/3 position on the sheet front end side is folded. Similarly, at the time of 1 / 3Z folding, the sheet fed to the second path 33 is folded at the 1/3 position on the sheet leading end side by the first second rolls 41b and 49, and then the sheet is folded at the 1/3 position on the sheet trailing end side. Match.

  Further, in the case of three-fold folding, when the quarter position shown in FIG. 12C is Z-folded, the sheet fed to the second path 33 is fed by the first second rolls 41b and 49 to the sheet rear end side 1 / 4 positions are folded, and then the 1/2 position of the sheet is folded.

[Control means 95]
The control means 95 for folding the sheet is configured as follows. 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.

  First, stopper means (not shown) for regulating the position of the sheet leading edge in the first switchback path 34 and the second switchback path 35 of the second path 33, or sensor means (S1, S2 shown in the figure) for detecting the position of the sheet leading edge. Is provided. In the illustrated apparatus, the first sensor S1 is arranged on the first switchback path 34, and the second sensor S2 is arranged on the second switchback path 35. The control unit 95 is configured to calculate the timing at which the fold position of the sheet reaches a predetermined position based on the sheet size information sent from the image forming apparatus A and the detection signal from the first second sensor S1 (S2). ing.

  Therefore, description will be made according to the control block diagram shown in FIG. In the image forming apparatus A, the control CPU 91 is provided with a control panel 15 and a mode setting unit 92. The control CPU 91 controls the paper feeding unit 3 and the image forming unit 7 according to the image forming conditions set on the control 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 transport motor Mf, and a driver circuit for the shift motor Ms. The control CPU 95 receives detection signals from the first sensor S1 and the second sensor S2. Further, the control CPU 95 transmits the “ON” and “OFF” control signals to the operating solenoid 44 provided in the pinch roller 41 a and the path switching means 63.

  In the control CPU 95, a folding process execution program for controlling the transport motor Mf, the shift motor Ms, the operating solenoid 44, and the path switching means 63 so as to execute the folding specifications described above is stored in the ROM 96. 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 shift motor Ms as data.

  The crease position calculation means 97 is an arithmetic circuit that calculates the crease position (dimension) from the leading edge of the sheet (distal edge in the sheet discharge direction) from the “sheet length size”, “folding specification”, and “binding margin dimension”. It is configured. For example, in the two-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 crease position is calculated by, for example, [{(sheet length size) − (binding margin)} / 2].

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

[Folding operation]
The operation of the configuration of the sheet folding apparatus B will be described. FIG. 8A shows a state in which the sheet that has entered the carry-in entrance 30 is corrected, and FIG. 8B shows a state in which the sheet has been carried into the first switchback path 34 for primary folding. 9A shows a state in which the sheet is folded at the primary folding position Np1, FIG. 9B shows a state in which the folded sheet is carried into the second switchback path 35, and FIG. 10A shows a secondary folding position Np2. FIG. 6B shows a state where the sheets are folded together, and FIG. FIG. 11A is an operation state diagram showing a folding operation in the bi-fold mode, and FIG. 11B is a flowchart of the control operation.

  In FIG. 8A, the sheet is guided to the carry-in entrance 30 and is sent downstream by a carry-in roller pair (first carrying means) 40. When the first sensor S1 detects the leading edge of the sheet, the control means 95 energizes the operating solenoid 44 on the basis of the detection signal and causes the pinch roller 41a to stand by at a position separated from the first roll 41b. At the same time, the control means 95 drives and rotates the shift motor Ms to move the primary folding deflection guide 53 from the standby position to the locking position.

  Then, the leading edge of the sheet abuts against the leading edge regulation surface 53S of the primary folding deflection guide 53 and is bent and deformed in a loop shape within the resist area. At this time, the leading edge of the sheet is aligned with the regulating surface 53S.

  Next, after a predetermined delay time (timer setting time) from the detection signal of the first sensor S1, the control means 95 turns off the operating solenoid 44 and returns the pinch roller 41a to the position in pressure contact with the first roll 41b. At the same time, the control means 95 rotates the shift motor Ms in the opposite direction to move the primary folding deflection guide 53 from the locking position to the standby position outside the path. With this operation, the leading end of the sheet is aligned at the restricting surface 53S at the locking position (actuating position), and the first path 32 is maintained while following the retracting operation of the leading end restricting surface 53S of the sheet and maintaining the posture in which the leading end is aligned. Move downstream.

  In FIG. 8B, the sheet is sent to the downstream side of the first path 32 by the first roll 41b rotating simultaneously with the rotation of the first conveying means 40. Then, the control means 95 controls the path switching means 63 to guide the seat from the first path 32 to the first switchback path 34 as shown.

  Then, the sheet is carried into the first switchback path 34 by the second conveying means 41. In the first path 32, a first sheet sensor S1 is disposed on the downstream side of the second conveying means 41, and detects the leading edge of the sheet carried into the first switchback path 34.

  In FIG. 9A, the control means 95 moves the elevating member 53c of the primary folding deflection guide 53 at the timing when the fold position of the sheet is transferred to a predetermined position based on the signal detected by the first sensor S1. Move from the standby position to the operating position. Then, the sheet in the first path 32 is deformed into a V shape toward the first nip portion Np1. When the driven roller 53a attached to the elevating member 53c is brought into pressure contact with the peripheral surface of the second roll 49, the sheet leading end side is fed out in the opposite direction (rotating direction of the second roll).

  On the other hand, the sheet trailing edge feeds the sheet toward the first nip portion Np1 by the conveying force of the second conveying means 41a. At this time, the curved guide surface of the guide surface 53b regulates the sheet along the peripheral surface of the roll so as to follow the peripheral surface of the first roll 41b.

  Therefore, the sheet is fed to the primary folding position Np1 by the driven roller 53a at the leading end side and the second conveying means 41a at the trailing end side toward the first nip portion Np1, and the raising / lowering timing of the raising / lowering member 53c is set to the crease position. It will be determined. Therefore, the control means 95 previously tests the speed at which the sheet is transferred by the second conveying means 41a and the timing at which the driven roller 53a is moved from the standby position to the operating position (particularly the timing at which the roller contacts the peripheral surface of the second roll 49). Use to set the optimum value.

  Since the curved guide surface of the guide surface 53b guides the sheet along the peripheral surface of the opposing first roll 41b in synchronization with the movement of the driven roller 53a from the standby position to the operating position, the sheet fold position However, there is no fear of changing each time.

  In FIG. 9B, a sheet that has been folded at the first nip portion Np1 at the 1/2 position (folded), the 1/3 position (trifold), and the 1/4 position (trifold) is the first nip. The conveyance force is applied at the part Np1 and the sheet is sent downstream. Therefore, the control means 95 positions the elevating member 54c of the secondary folding deflection guide 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 folding in half, the elevating member 54c is positioned at the operating position, and the folded sheet is guided from the leading end to the second nip portion Np2 and sent to the carry-out port 31 on the downstream side.

  Therefore, in the three-fold mode, the control means 95 positions the elevating member 54c of the secondary folding deflection guide 54 at the standby position as shown in FIG. 9B. Then, the sheet sent from the first nip portion Np1 is sent from the leading edge to the second switchback path 35. Then, the second sensor S2 detects the leading end (fold position) of the sheet.

  In FIG. 10A, the control means 95 moves the elevating member 54c of the secondary folding deflection guide 54 from the standby position when the secondary folding position reaches the predetermined position based on the detection signal of the second sensor S2. Move to operating position. Then, the sheet in the second switchback path is fed out in the opposite direction when the driven roller 54 a comes into contact with the peripheral surface of the third roll 50.

  As a result, the front end side of the sheet is driven by the driven roller 54a, and the rear end side is fed by the first nip portion Np1 in the opposite direction to guide the sheet to the second nip portion Np2. In this case, the moving timing of the elevating / lowering member 54c from the standby position to the operating position is the same as that of the primary folding deflection guide 53 described above, and the operation of the guide member 54b is also the same.

  In FIG. 10B, the folded sheet sent to the secondary folding position (second nip portion) Np2 is reliably folded by the additional folding roller 64 pressed against the second roll 49, and the third path 36. Therefore, the control means 95 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 letter folding specifications of three-fold folding and 1 / 3Z-folding, which need not be bound by the post-processing apparatus C. To do.

  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.

[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. 11B, the image forming apparatus A receives a mode instruction signal as to whether or not folding processing is performed simultaneously with the paper discharge instruction signal. Then, the control means 95 calculates the crease position by the crease position calculation means 97 (St01). Accordingly, in the control unit 95, the first sensor S1 detects the leading edge of the sheet (St03) in the bi-fold mode (St02). The primary folding deflection guide 53 is moved from the standby position to the operating position (St05) after elapse of a sheet feeding time corresponding to the sheet length calculated by the fold position calculation means 97 from this detection signal (St04). This movement is controlled by the rotation of the shift motor Ms.

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

  At this time, the control means 95 operates the secondary folding deflection guide 54 after the expected time when the sheet fold is inserted into the first nip portion Np1 based on the detection signal from the first sensor S1 in the bi-fold mode (St06). Move to the position (St07). This estimated time is set to a time before the fold position of the sheet is inserted into the first nip portion Np1 and the leading end of the folded sheet reaches the guide member 54b. Therefore, the leading edge of the folded sheet is guided by the curved guide surface of the guide member 54b in the state of FIG.

  At the same time, the driven roller 54a located at the operating position is rotated in the direction indicated by the arrow in FIG. 11A following the rotation of the third roll 50, so that the leading edge of the folded sheet deviates from the second nip portion Np2. Even if it is curled, it is reliably guided to the second nip portion Np2 by the rotation of the driven roller 54a and the third roll 50.

  Accordingly, the control means 95 carries out the folded sheet carried out from the second nip portion Np2 to the third path 36 to the first path 32 from the third path 36. Then, the control means 95 prepares for the subsequent sheet processing with the secondary folding deflection guide 54 positioned at the operating position (St08). The illustrated one has a relationship in which the primary folding deflection guide 53 is positioned at the standby position, and the secondary folding deflection guide 54 that moves in the opposite direction is positioned at the operating position. It is also possible to configure so that the secondary folding deflection guide 54 is moved to the standby position by the detection signal of the paper sensor S3.

[Folding operation in three-fold mode]
In the mode in which the sheet is folded in three, as described with reference to FIGS. 8 to 10, the image forming apparatus A receives a mode instruction signal as to whether or not folding processing is performed simultaneously with the paper discharge instruction signal. Then, the control means 95 calculates the crease position by the crease position calculation means 97 (St01). Therefore, in the three-fold mode (St09), the control means 95 detects the leading edge of the sheet (St10).

  The primary folding deflection guide 53 is moved from the standby position to the operating position after the passage of the sheet feed time corresponding to the length of the sheet calculated by the fold position calculation 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 elevating member 53c of the primary folding deflection guide 53 moves to the operating position, the sheet of the first path 32 is distorted toward the first nip portion Np1 with reference to the fold position as described with reference to FIG. Is done. When the driven roller 53a of the primary folding deflection guide 53 comes into contact with the peripheral surface of the second roll 49, the sheet is squeezed and inserted into the first nip portion Np1 from the fold position. At this time, the control means 95 waits for the second sensor S2 to detect the leading edge of the sheet (St13) in the three-fold mode.

  Based on the signal that the second sensor S2 has detected the leading edge of the sheet, the control means 95 moves the secondary folding deflection guide 54 to the operating position after the estimated time that the secondary folding position of the sheet reaches the predetermined position (St14). (St15). This expected time is set by the calculated value of the crease position calculating means 97. Therefore, the sheet is inserted into the second nip portion Np2 with a conveying force applied from the driven roller 54a. The front end of the sheet is detected by the paper discharge sensor S3 and is carried out from the third path 36 to the first path 32 according to the folding specification, or is carried out from the paper discharge path 37 to the storage stacker 65.

  In the present invention, when the post-processing mode in which the sheet folding process is not performed is set by the mode setting unit 92 described above, it goes without saying that the sheet carried into the first path 32 is directly sent to the carry-out port 31. .

[Output path configuration]
The folded sheets folded in half as described above are sent to the third path 36 from the pressure contacts of the second and third rolls 49 and 50. Then, it is further folded by an additional folding roller 64 that is in pressure contact with the second roller 49 and guided to the third path. 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 path 37 is configured as described above with a curvature R3. Reference numeral 67 in the figure denotes a paper discharge roller disposed in the paper discharge path 37.

  Therefore, sheets that are folded into letter specifications such as inner three-fold or 1 / 3Z-fold 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 pair of discharge rollers 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 using the control panel 15 described above. 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 out the sheet from the main body discharge port 18. The sheet feeding unit 3 stores sheets of a plurality of sizes in sheet feeding cassettes 4 a and 4 b, and separates designated sheets one by one and feeds them 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 disposed 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. 13 is a circulation path. The sheet printed on the front surface side from the fixing device 12 is turned upside down via the main body switchback path 14 and then fed again to the image forming unit 7 to be printed on the back surface side of the sheet. This is the path for duplex printing. 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.

  An image reading unit 20 shown in FIG. 1 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. Reference numeral 25 denotes a document feeder, which feeds document sheets 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 91, and image forming conditions such as sheet size designation, color / monochrome printing designation, print number designation, single-sided / double-sided printing designation, enlarged / reduced printing designation from the control panel 15. The printout conditions such as 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 control 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]
As shown in FIG. 2, the post-processing device C has the following configuration. 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 the sheet from the first path 32 or the third 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. Reference numeral 73 in the drawing denotes a paper discharge port for collecting sheets from the post-processing path 71 on a processing tray 72 arranged on the downstream side. A 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 76 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. Reference numeral 78 shown in the figure denotes alignment means that aligns the sheets carried on the processing tray in the direction perpendicular to the conveyance direction. Reference numeral 79 denotes a paddle rotating body, which 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.

  Reference numeral 80 in the drawing denotes sheet bundle carrying-out means, which transfers the sheet bundle bound together by the stapler unit 77 to the sheet discharge stacker 70 on the downstream side. 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. In the drawing, Mm is a drive motor that swings the lever member 81. Although not shown, the paper discharge stacker 70 is provided with an elevator mechanism that moves up and down according to the amount of stacked sheets.

A Image forming apparatus B Sheet folding apparatus C Post-processing apparatus Mf Transfer motor Ms Shift motor Ar Registration area S1 First sensor S2 Second sensor S3 Paper discharge sensor Np1 Primary folding position (first nip portion)
Np2 secondary folding position (second nip)
30 carry-in port 31 carry-out port 32 1st conveyance path | route (1st path | route)
33 Second transport path (second path)
34 First switchback path 35 Second switchback path 36 Third transport path (third path)
37 Paper discharge path 40 Carry-in roller pair (first transport means)
41a Pinch roller (second conveying means)
41b First roll 42 Gate stopper means 43 Bracket (elevating arm member)
44 Actuation solenoid (roller lifting / lowering means)
43x support shaft 45 urging spring 48 folding processing means 49 second roll 50 third roll 53 primary folding deflection guide (deflection means)
53a Follower roller 53b Guide surface 53c Lifting member 53S Sheet leading edge regulating surface 54 Secondary folding deflection guide (deflection means)
54a Follower roller 54b Guide member 54c Elevating member 56 Shift means 62 Unloading roller pair 63 Path switching means (plate-shaped guide piece)
64 Additional folding roller (drive roller)
65 Storage Stacker 91 Control CPU (Image Forming Apparatus)
92 Mode setting means 95 Control means 97 Fold position calculation means

Claims (9)

A sheet feeding apparatus that aligns the leading edge of a sheet sent to a carry-in path and transfers the sheet to a predetermined folding processing position,
A carry-in path for feeding the sheet to a predetermined folding processing position;
A first and a second pair of folding rolls arranged in the carry-in path and for folding the sheet;
A pair of transport rollers disposed in the carry-in path so as to be capable of being pressed and separated; and
A registration area arranged on the upstream side of the pair of conveying rollers to bend and deform the sheet;
Gate stopper means arranged on the downstream side of the pair of conveying rollers to abut and regulate the leading end of the sheet;
Roller lifting and lowering means for pressing and separating the conveying roller pair;
Control means for controlling the roller lifting means;
With
The gate stopper means includes
A fold guide member for guiding a fold position of the sheet sent from the carry-in path to the pressure contact portion of the pair of folding rolls;
A sheet tip regulating surface formed on the folding guide member;
Shift means that moves between a standby position in which the folding guide member is retracted from the carry-in path and an operating position that guides the sheet to the pressure contact portion of the pair of folding rolls;
Consists of
The sheet feeding device, wherein the control unit causes the sheet to be curved in the registration area by separating the pair of conveying rollers in a state where the sheet leading edge regulating surface is positioned in the carry-in path. The carry-in path includes a first transport path that guides the sheet to the carry-out exit without folding the sheet,
The sheet feeding device according to claim 1, wherein a second conveyance path for folding the sheet and guiding the sheet to the carry-out port is connected via a path switching unit. The carry-in path is arranged so as to cross the device housing in a substantially horizontal direction,
The first folding roll is arranged so that at least a part thereof faces the carry-in route,
The second transport path is configured by a curved path that guides the leading end of the sheet so as to position the fold of the sheet at a press-contact portion between the first folding roll and the second folding roll. The sheet feeding apparatus according to the description. The first folding roll moves the sheet from the carry-in path toward the curved path of the second transport path in cooperation with the transport roller pair,
The sheet feeding device according to claim 3, wherein the second folding roll moves the sheet from the curved path to the folding processing path in cooperation with the first folding roll. The second folding roll is provided with a third folding roll that is in pressure contact with each other,
5. The sheet feeding apparatus according to claim 4, wherein the sheet folded first by the first folding roll and the second folding roll is secondarily folded by the second folding roll and the third folding roll. 6. The conveying roller pair is
It is composed of the first folding roll and a pinch roller disposed so as to be capable of being pressed and separated from the first folding roll.
The said 1st folding roll and the said pinch roller are formed so that the roll diameter of a 1st folding roll is larger than the roll diameter of a pinch roller, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. Sheet feeding device. The folding guide member is
A sliding member supported on the device frame so as to be slidable between the standby position and the operating position;
A sheet tip regulating surface formed on the sliding member and abutting and locking the sheet tip;
A driven roller rotatably attached to the sliding member;
The sheet feeding apparatus according to claim 1, comprising: A device that folds a sheet from a carry-in entrance and carries it out to a carry-out exit,
A first conveyance path that guides the sheet from the carry-in entrance to the carry-out exit without folding the sheet;
A second conveyance path for folding the sheet from the carry-in port and guiding the sheet to the carry-out port;
Folding processing means arranged in the second transport path for folding sheets from the carry-in entrance;
With
The first transport path is provided with a sheet feeding device that aligns the leading edge of the sheet sent from the carry-in entrance and transfers the sheet to a predetermined processing position.
A sheet folding apparatus comprising the structure according to any one of claims 1 to 7. An image forming apparatus for sequentially forming images on sheets;
A sheet folding apparatus for folding sheets from the image forming apparatus;
Consisting of
An image forming system comprising the sheet folding device according to claim 8.

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