JP2017132572A - Post-processing device and image formation apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a post-processing device which can be miniaturized and has high convenience and an image formation apparatus having the same.SOLUTION: A post-processing device includes: a center roller 11; a folding roller 12 which forms a nip N1 by contacting with the center roller 11; and a folding roller 13 which forms a nip N2 by contacting with the center roller 11. The center roller 11 and the folding roller 12 perform folding of a sheet at the nip N1 and convey the sheet to a conveyance path TR2a via the nip N1. The center roller 11 and the folding roller 13 perform folding of a sheet at the nip N2 and convey the sheet to a conveyance path TR2b via the nip N2.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a post-processing apparatus and an image forming apparatus including the post-processing apparatus. More specifically, the present invention relates to a post-processing apparatus that folds a sheet and an image forming apparatus including the same.

  Electrophotographic image forming apparatuses include a scanner function, a facsimile function, a copying function, a function as a printer, a data communication function, and a server function, an MFP (Multi Function Peripheral), a facsimile apparatus, a copying machine, a printer, and the like. is there.

  2. Description of the Related Art Post processing apparatuses that perform post processing on paper printed by an image forming apparatus are known. The post-processing apparatus is usually attached to the image forming apparatus. The processing that can be performed by the post-processing device includes a process of saddle-stitching and folding a plurality of sheets at the center, a Z-folding process for folding a large-sized page into a three-page Z-shape, and a hole in the sheet. There is a process for opening or stapling a sheet.

  In addition, the technique regarding the conventional Z folding apparatus is disclosed by the following patent documents 1-3 etc., for example. Patent Document 1 below discloses a sheet post-processing apparatus that performs a stacking process in which sheets are reversed and stacked without performing a folding process on a sheet that has been formed and loaded.

  In the following Patent Document 2, a first folding unit that forms a first fold on a sheet, a second folding unit that forms a second fold on a sheet on which a first fold is formed by the first folding unit, A sheet post-processing apparatus is disclosed that includes a conveyance destination switching unit that switches a conveyance destination of a sheet on which a first fold is formed by a first folding unit to a second folding unit or a first discharge unit.

  In the following Patent Document 3, a pair of conveying rollers, a central roller provided on the downstream side of the conveying roller pair, two folding rollers driven to rotate by the central roller, and both sides of a sheet fed by the conveying roller pair are provided. A paper folding apparatus having a pair of extruded rollers is disclosed. In this paper folding apparatus, the pair of extrusion rollers is connected to the first position for extruding the sheet to the one folding roller side and the other folding roller side in conjunction with the movement of the driven roller constituting the conveying roller pair. Move between the second position to push out.

JP 2012-250791 A JP 2011-201649 A JP 07-179265 A

  FIG. 13 is a diagram schematically showing the appearance of a conventional image forming apparatus 1100.

  Referring to FIG. 13, in the conventional image forming apparatus 1100, when the Z-folding apparatus 1010 is mounted on the image forming apparatus main body 1002 together with the post-processing apparatus 1001 having other functions, the Z-folding apparatus 1010 is conventionally configured to perform image formation. It is provided between the image forming apparatus main body 1002 that performs the above and another post-processing apparatus 1001.

  From the viewpoint of reducing the size and space of the entire image forming apparatus, it has been attempted to provide the post-processing device 1001 and the Z-folding device 1010 in one housing. In this case, the Z-folding device 1010 is disposed in the paper passing path of the post-processing device 1001.

  Incidentally, some post-processing apparatuses 1001 have a post-insert function. The post-insert function refers to a case where a plurality of sheets output from the image forming apparatus are processed by a post-processing apparatus (for example, when a plurality of sheets are saddle-stitched to produce a booklet). This is a function for inserting (post-inserting) paper (such as a booklet cover or cover) different from the paper output from the image forming apparatus.

  However, many of the Z-folding apparatuses 1010 convey the sheet downstream after reversing (switching back) the traveling direction of the sheet after Z-folding from the viewpoint of simplifying the apparatus configuration. For this reason, when the post-processing apparatus 1001 has a post-insert function, the post-inserted paper is output in a state where the page order (paper feed order) is changed due to the reversal of the traveling direction, which is extremely inconvenient. There was a problem.

  Further, in order to maintain the page order of post-inserted paper, if the paper passing path of the Z-folded paper and the paper passing path of the post-inserted paper are separated, the transport path and the paper passing path are switched. There is a need to provide a nail or a new transport roller, and there is a problem that the post-processing apparatus is increased in size or complexity, or costs are increased.

  The problem of lack of convenience or the increase of the size of the post-processing apparatus is a problem that may also occur when the Z-folding device is arranged in the paper passing path of the post-processing apparatus having functions other than the post-insert function. It was.

  SUMMARY An advantage of some aspects of the invention is that it provides a post-processing device that can be reduced in size and an image forming apparatus including the post-processing device.

  Another object of the present invention is to provide a convenient post-processing apparatus and an image forming apparatus including the post-processing apparatus.

  The post-processing apparatus according to one aspect of the present invention includes a central roller, a first roller that forms a first nip by contacting the central roller, and a second roller that is different from the first nip by contacting the central roller. A central roller and a first roller for folding the paper at the first nip and feeding the paper to the first transport path via the first nip. The central roller and the second roller fold the paper at the second nip, and transport the paper to the second transport path different from the first transport path via the second nip.

  Preferably, in the post-processing apparatus, a first conveyance unit that conveys a target sheet to be Z-folded to a first conveyance path through a first nip, and the first conveyance unit causes the first sheet to be a target sheet. After transporting a required distance to the transport path, the first fold is formed on the target paper by the second nip, and the first fold is formed on the target paper by the first fold. And a second folding unit configured to form a second fold on the target sheet by the first nip.

  Preferably, in the post-processing apparatus, the first transport unit rotates each of the central roller and the first roller in a direction in which the target sheet is transported to the first transport path, and the first folding unit includes the first folding unit. The central roller is rotated in the direction opposite to the direction of rotation by the conveying means, the second roller is rotated in the direction of conveying the target paper to the second conveying path, and the second folding means The central roller is rotated in the direction of conveyance to the first conveyance path, and the second roller is rotated in a direction opposite to the direction of rotation by the first folding means.

  Preferably, in the post-processing apparatus, an inlet for introducing paper printed on the image forming apparatus main body into the post-processing apparatus, and the post-processing apparatus without passing through the inlet from the outside of the post-processing apparatus and the image forming apparatus main body. A paper feeding mechanism for introducing paper into the printer, a printing paper transporting means for transporting the paper that is not Z-folded introduced from the inlet to the first transport path via the first nip, and paper feeding The apparatus further includes an external sheet conveyance unit that conveys the sheet, which is not Z-folded, introduced by the mechanism to the second conveyance path via the second nip.

  Preferably, in the post-processing apparatus, the first conveyance path and the second conveyance path are merged to form a third conveyance path, and the sheet that is not Z-folded introduced from the introduction port is provided. A reversing device for reversing the advancing direction of the paper being transported on the transport path, a half-folding device for folding the paper introduced through the third transport path in the center, and a center portion in the center folding device And a paper output tray for discharging the paper after being folded in half, and the intermediate folding device is configured such that the lower end of the paper to be folded in the center is facing the discharge tray. Contains paper to be folded in half.

  In the post-processing device, preferably, the half-folding device is provided below the second nip.

  In the post-processing apparatus, the paper feed mechanism is preferably detachable.

  Preferably, the post-processing apparatus further includes a switching member that switches the paper transport path between the first transport path and the second transport path.

  Preferably, in the post-processing apparatus, the switching member presses a portion of the target paper that becomes the first fold when the first fold is formed on the target paper that is the target of Z-folding.

  In the post-processing apparatus, preferably, the pressure of the first nip when the Z-folding of the sheet is performed at the first nip is the same as the first nip when the sheet that is not Z-folded is transported to the first transport path. 1st pressure control means to make it higher than the pressure of this is further provided.

  In the post-processing apparatus, preferably, the first pressure control means is detachable.

  Preferably, in the post-processing apparatus, the first unit including the first pressure control unit and a switching member that switches the paper transport path between the first transport path and the second transport path is the first unit. It is possible to replace the second unit including the switching member without including the pressure control means.

  In the post-processing apparatus, preferably, the pressure of the second nip when the sheet is Z-folded at the second nip is set to the second nip when the sheet that is not Z-folded is conveyed to the second conveyance path. 2nd pressure control means to make it higher than the pressure of this is further provided.

  Preferably, in the post-processing apparatus, the first transport path is a transport path for discharging the sheet to the side surface of the post-processing apparatus opposite to the side surface of the post-processing apparatus on which the image forming apparatus main body is provided.

  In the post-processing apparatus, preferably, when the sheet is not transported to the second transport path, the second roller can be replaced with a guide for guiding the sheet to the first nip.

  An image forming apparatus according to another aspect of the present invention includes an image forming apparatus main body that prints on a sheet, and the post-processing apparatus that performs post-processing on the sheet printed on the image forming apparatus main body.

  According to the present invention, it is possible to provide a post-processing apparatus that can be reduced in size and an image forming apparatus including the post-processing apparatus. Further, according to the present invention, it is possible to provide a convenient post-processing apparatus and an image forming apparatus including the post-processing apparatus.

1 is a diagram schematically illustrating an appearance of an image forming apparatus 100 according to a first embodiment of the present invention. 1 is a block diagram illustrating a functional configuration of an image forming apparatus 100 according to a first embodiment of the present invention. It is sectional drawing which shows the structure of the post-processing apparatus 1 in the 1st Embodiment of this invention. In the first embodiment of the present invention, a conveyance path through which each of a sheet introduced from the post inserter 50 that does not perform Z-folding and a sheet introduced from the image forming apparatus main body 2 that does not perform Z-folding passes. FIG. It is sectional drawing which shows the structure of the Z folding apparatus 10 in the 1st Embodiment of this invention. FIG. 5 is a cross-sectional view illustrating an operation when the Z-folding device 10 switches a paper transport path in the first embodiment of the present invention. FIG. 6 is a cross-sectional view showing a first operation when the Z-folding device 10 performs Z-folding on a sheet in the first embodiment of the present invention. FIG. 6 is a cross-sectional view showing a second operation when the Z-folding device 10 performs Z-folding on a sheet in the first embodiment of the present invention. FIG. 6 is a diagram showing a booklet BL1 produced when sheets SH1 and SH2 are fed from a post inserter 50 in the first embodiment of the present invention. As a comparative example of the present invention, it is a diagram showing a booklet BL2 produced when the transport direction of the paper SH1 and SH2 fed from the post inserter 50 is reversed. In the 2nd Embodiment of this invention, it is sectional drawing which shows the structure of the post-processing apparatus 1 with which the guide unit 30A was mounted | worn. In the 3rd Embodiment of this invention, it is a fragmentary sectional view which shows the structure of the post-processing apparatus 1 with which 10 A of conveyance path switching apparatuses were mounted | worn. FIG. 11 is a diagram schematically showing the appearance of a conventional image forming apparatus 1100.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the following embodiment, a case where the post-processing device is a part of an image forming apparatus will be described. Examples of the image forming apparatus include an MFP, a printer, a copier, and a facsimile. The post-processing apparatus is configured separately from the image forming apparatus main body, and may be detachable from the image forming apparatus main body as necessary.

  [First Embodiment]

  FIG. 1 is a diagram schematically showing an external appearance of an image forming apparatus 100 according to the first embodiment of the present invention.

  With reference to FIG. 1, an image forming apparatus 100 in the present embodiment includes a post-processing apparatus 1 and an image forming apparatus main body 2. The image forming apparatus main body 2 performs printing on paper. The post-processing device 1 includes a Z-folding device 10, a post inserter (an example of a paper feed mechanism) 50, a saddle unit 60 (an example of a middle folding device), and the like. The Z folding device 10 and the saddle unit 60 are provided inside the housing of the post-processing device 1. The post inserter 50 is provided in the upper part of the casing of the post-processing apparatus 1. Each of the Z folding device 10, the post inserter 50, and the saddle unit 60 is detachable from the post-processing device 1.

  Since the Z-folding apparatus 10 is provided inside the post-processing apparatus 1, the image forming apparatus 100 is downsized in the horizontal direction (machine width) in FIG. 1 compared to the image forming apparatus 1100 in FIG. ing.

  The post-processing apparatus 1 performs, for example, a half-folding process or a Z-folding process on the paper after printing by the image forming apparatus main body 2 or the paper introduced into the post-processing apparatus 1 by the post inserter 50. Perform post-processing. The post-processing apparatus 1 may further perform post-processing such as punching processing and stapling processing.

  FIG. 2 is a block diagram showing a functional configuration of the image forming apparatus 100 according to the first embodiment of the present invention.

  Referring to FIG. 2, an image forming apparatus 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a scanner 104, a network interface 105, and an operation. A panel 106, an auxiliary storage device 107, an image forming unit 108, and a post-processing control unit 109 are included. The CPU 101, the ROM 102, the RAM 103, the scanner 104, the network interface 105, the operation panel 106, the auxiliary storage device 107, the image forming unit 108, and the post-processing control unit 109 are mutually connected by a bus or the like.

  The CPU 101 operates according to the control program and controls the entire image forming apparatus 100.

  The ROM 102 stores a control program.

  A RAM 103 is a working memory for the CPU 101 and temporarily stores various data.

  The scanner 104 reads an image of a document.

  The network interface 105 transmits and receives information to and from an external device connected to the image forming apparatus 100 through a network (not shown).

  The operation panel 106 displays various information and accepts various operations.

  The auxiliary storage device 107 stores various data such as image data to be printed.

  The image forming unit 108 performs printing on a sheet inside the image forming apparatus main body 2. The image forming unit 108 is roughly composed of a toner image forming unit, a fixing device, a paper transport unit, and the like. The image forming unit 108 forms an image on a sheet by, for example, electrophotography. The toner image forming unit combines four color images by a so-called tandem method, and forms a color image on a sheet. The toner image forming unit includes a photoconductor provided for each color of C (cyan), M (magenta), Y (yellow), and K (black), and an intermediate in which a toner image is transferred (primary transfer) from the photoconductor. The image forming apparatus includes a transfer belt and a transfer unit that transfers an image from the intermediate transfer belt to a sheet (secondary transfer). The fixing device has a heating roller and a pressure roller. The fixing device conveys the sheet on which the toner image is formed between the heating roller and the pressure roller, and heats and presses the sheet. As a result, the fixing device melts the toner adhering to the paper and fixes it on the paper to form an image on the paper. The paper transport unit includes a paper feed roller, a transport roller, and a motor that drives them. The paper transport unit feeds paper from the paper feed cassette and transports it inside the image forming apparatus main body 2. The paper transport unit introduces the paper printed by the image forming apparatus main body 2 from the image forming apparatus main body 2 into the post-processing apparatus 1.

  The post-processing control unit 109 controls the overall operation of the post-processing device 1 under the control of the CPU 101.

  FIG. 3 is a cross-sectional view showing the configuration of the post-processing apparatus 1 according to the first embodiment of the present invention. Note that the right side surface in FIG. 3 is the side surface to which the image forming apparatus main body 2 is adjacent.

  Referring to FIG. 3, post-processing apparatus 1 includes main tray 71, belt tray 72 (an example of a discharge tray), transport roller pairs 81 to 85, transport paths TR0, TR1, and TR2a (first transport path). ), TR2b (an example of a first transport path), TR2c (a bypass path), TR3 (an example of a third transport path, a saddle path), and TR4. The driving state of each of the conveyance roller pairs 81 to 85 is controlled by the post-processing control unit 109.

  The post inserter 50 introduces paper into the post-processing apparatus 1 from outside the post-processing apparatus 1 and the image forming apparatus main body 2 without passing through the introduction port IL. The post inserter 50 includes a paper feed tray 51 and a paper feed roller 52. In the paper feed tray 51, paper to be introduced into the post-processing apparatus 1 is placed. The paper feed roller 52 feeds the paper placed in the paper feed tray 51 to the transport path TR1.

  The paper introduced by the post inserter 50 is the image forming apparatus main body 2 when the saddle unit 60 performs half-folding and saddle stitching processing on the paper printed by the image forming apparatus main body 2 (when producing a booklet). A cover provided for the paper printed in step 1, a document inserted between a plurality of papers printed by the image forming apparatus main body 2, and the like.

  The transport path TR <b> 1 extends downward from the paper feed roller 52, curves to the left in FIG. 3 on the downstream side of the transport roller pair (finisher entrance roller) 83, and reaches the Z-folding device 10. The transport roller pairs 81 to 83 are provided along the transport path TR1. The transport roller pairs 81 to 83 transport the paper fed by the paper feed roller 52 to the Z-folding device 10 along the transport path TR1.

  The introduction port IL is an introduction port for introducing a sheet printed by the image forming apparatus main body 2 from the image forming apparatus main body 2 into the post-processing apparatus 1. The transport path TR0 extends in the left direction in FIG. 3 from the introduction port IL, and is connected to the transport path TR1 on the upstream side of the transport roller pair 83.

  The transport path TR1 branches into a transport path TR2a and a transport path TR2b inside the Z-folding apparatus 10. When the conveyed sheet is a sheet that is not Z-folded, the Z folding device 10 switches the sheet conveyance path between the conveyance path TR2a and the conveyance path TR2b and passes the sheet. The detailed configuration and operation of the Z-folding device 10 will be described later.

  The transport path TR <b> 2 a extends to the left in FIG. 3 and reaches the main tray 71. The transport path TR <b> 2 a is a transport path for temporarily discharging the paper to the main tray 71. The transport roller pair 84 (an example of a reversing device) is provided along the transport path TR2a. The transport path TR2a is connected to the transport path TR2c on the right side of the transport roller pair 84 in FIG. The transport path TR2c extends downward from the transport path TR2a.

  The conveying roller pair 84 reverses the traveling direction of the paper that is not Z-folded introduced from the inlet IL. Specifically, the transport roller pair 84 transports the paper transported from the Z-folding device 10 in the left direction in FIG. 3 and temporarily discharges it onto the main tray 71 outside the post-processing device 1. Subsequently, the conveyance roller pair 84 conveys the sheet discharged to the outside of the post-processing apparatus 1 in the right direction in FIG. 3 by reversing the rotation direction. The transport roller pair 84 introduces the paper discharged to the outside of the post-processing apparatus 1 again into the post-processing apparatus 1 and transports the paper along the transport path TR2c.

  The transport path TR2b extends downward in FIG. The transport path TR2b and the transport path TR2c merge to form a transport path TR3. The transport path TR3 extends downward in FIG. 3 and reaches the saddle unit 60. The transport roller pair 85 is provided along the transport path TR3. The transport roller pair 85 transports the sheet from the transport path TR2b or TR2c to the saddle unit 60 along the transport path TR3.

  The saddle unit 60 performs half-folding (two folding at the center) on the paper introduced through the transport path TR3. The saddle unit 60 includes conveying roller pairs 61 and 62, a folding member 63, a folding roller pair 64, and a stack unit 65. The transport path TR3 is connected to the transport path TR4 on the right side of the folding roller pair 64 in FIG. The transport path TR4 extends leftward in FIG. 3 and reaches the belt tray 72. The transport roller pair 61 is provided along the transport path TR3. The transport roller pair 62 and the folding roller pair 64 are provided along the transport path TR4. The folding member 63 is provided to face the folding roller pair 64 with the transport path TR3 interposed therebetween. The post-processing control unit 109 controls the driving states of the transport roller pairs 61 and 62, the folding member 63, and the folding roller pair 64.

  The transport roller pair 61 accommodates (stacks) the paper transported into the saddle unit 60 in the stack unit 65. When a plurality of sheets are folded in the middle, the plurality of sheets are stored in the stack unit 65. The saddle unit 60 stacks the paper with the lower end of the paper facing the belt tray 72 side (left side in FIG. 3) and the upper end of the paper faces the image forming apparatus main body 2 side (right side in FIG. 3). 65. After the sheets are stored in the stack unit 65, the folding member 63 moves in the direction indicated by the arrow AR21. Thereby, the folding position of the sheet is pressed by the folding member 63 and introduced into the nip of the folding roller pair 64. The pair of folding rollers 64 rotates in the direction of transporting the paper along the transport path TR4. As a result, the sheet is folded in half. The pair of transport rollers 62 transports the folded paper along the transport path TR4 and discharges it to the belt tray 72. The main tray 71 and the belt tray 72 are provided on the side surface opposite to the side surface on which the image forming apparatus main body 2 is provided.

  FIG. 4 is a diagram illustrating a case where a sheet that is not Z-folded introduced from the post inserter 50 and a sheet that is not Z-folded introduced from the image forming apparatus main body 2 are used in the first embodiment of the present invention. It is a figure which shows the conveyance path which passes.

  Referring to FIG. 4, the sheet introduced from post inserter 50 and not Z-folded passes through conveyance paths TR1, TR2a, TR2c, and TR3 in this order as shown by arrow AR1, and saddle unit 60 To reach. The sheet that is not Z-folded introduced from the image forming apparatus main body 2 through the inlet IL passes through the transport paths TR1, TR2b, and TR3 in this order as shown by the arrow AR2, and reaches the saddle unit 60.

  The paper introduced from the image forming apparatus main body 2 through the introduction port IL is reversed in the traveling direction by the conveying roller pair 84, and therefore the page order (paper feeding order) is changed. Therefore, the image forming unit 108 forms an image on a sheet with a layout (printing order) in consideration of reversal of the sheet traveling direction.

  FIG. 5 is a cross-sectional view showing the configuration of the Z-folding device 10 according to the first embodiment of the present invention.

  Referring to FIG. 5, the Z-folding device 10 includes a central roller 11, a folding roller 12 (an example of a first roller), a folding roller 13 (an example of a second roller), and a swinging claw 14 (switching). An example of a member), a movable guide 15, motors 21 and 22, cams 23 and 24, and sensors SE1 (FIG. 7B) and SE2 (FIG. 8A) are included. The driving state of each of the central roller 11 and the motors 21 and 22 is controlled by the post-processing control unit 109. The operations of the swing claw 14 and the movable guide 15 are also controlled by the post-processing control unit 109.

  The central roller 11 is rotationally driven by a motor (not shown), and each of the folding rollers 12 and 13 is rotated following the central roller 11. Each of the folding rollers 12 and 13 may be rotationally driven independently of the rotational driving of the central roller 11.

  The central roller 11 can rotate in both the direction in which the paper is transported from the transport path TR1 to the transport path TR2a and the direction in which the paper is transported from the transport path TR1 to the transport path TR2b.

  The folding roller 12 is in contact with the central roller 11 to form a nip N1 (an example of a first nip). The center roller 11 and the folding roller 12 perform the first folding at the nip N1 by a method described later on the sheet to be Z-folded. Further, the central roller 11 and the folding roller 12 are introduced by the post inserter 50, and convey the sheet which is conveyed from the conveyance path TR1 and which is not Z-folded, to the conveyance path TR2a via the nip N1.

  The folding roller 13 is in contact with the center roller 11 to form a nip N2 (an example of a second nip). The center roller 11 and the folding roller 13 perform the second folding at the nip N <b> 2 by a method to be described later on the sheet to be Z-folded. Further, the central roller 11 and the folding roller 13 convey the sheet, which is introduced from the introduction port IL and is conveyed from the conveyance path TR1, and which is not Z-folded, to the conveyance path TR2b via the nip N2.

  The swinging claw 14 rotates about the fulcrum 14a to switch the transport path of the paper that is transported from the transport path TR1 and is not Z-folded between the transport path TR2a and the transport path TR2b. Further, when the first fold is formed on the sheet to be Z-folded, the swinging claw 14 presses the portion that becomes the first fold in the sheet.

  When the movable guide 15 forms the second fold on the sheet to be Z-folded, the movable guide 15 presses the portion of the sheet that becomes the first fold. The movable guide 15 rotates around the fulcrum 15a.

  The cam 23 is in contact with the rotating shaft of the folding roller 12 and is driven to rotate by the motor 21. The rotation of the motor 21 is controlled by the post-processing control unit 109. As the cam 23 rotates, the pressing force that the cam 23 applies to the rotation shaft of the folding roller 12 changes. Thereby, the motor 21 and the cam 23 (first pressure control means) control the pressure of the nip N1. The motor 21 and the cam 23 make the pressure of the nip N1 when folding the sheet at the nip N1 higher than the pressure of the nip N1 when conveying the sheet to the transport path TR2a via the nip N1.

  The cam 24 is in contact with the rotation shaft of the folding roller 13 and is driven to rotate by the motor 22. The rotation of the motor 22 is controlled by the post-processing control unit 109. As the cam 24 rotates, the pressing force that the cam 24 applies to the rotation shaft of the folding roller 13 changes. Thereby, the motor 22 and the cam 24 (second pressure control means) control the pressure of the nip N2. The motor 22 and the cam 24 make the pressure of the nip N2 when folding the sheet at the nip N2 higher than the pressure of the nip N2 when conveying the sheet to the transport path TR2b via the nip N2.

  The post-processing device 1 may further include a sensor for detecting the positions of the swinging claw 14, the movable guide 15, the cam 23, the cam 24, and the like in order to increase the positional accuracy.

  FIG. 6 is a cross-sectional view showing an operation when the Z-folding device 10 switches the paper transport path in the first embodiment of the present invention.

  In FIG. 6A, each of the swinging claw 14 and the movable guide 15 exists at the initial position. In this state, the sheet conveyed from the conveyance path TR1 is guided to the conveyance path TR2a as indicated by an arrow AR1.

  From the state shown in FIG. 6A, the movable guide 15 moves to the folding position as shown by the arrow ME1 (FIG. 6B), and the swinging claw 14 moves to the paper guide position as shown by the arrow ME2. (FIG. 6C). In the state of FIG. 6C, the sheet conveyed from the conveyance path TR1 is guided to the conveyance path TR2b as indicated by an arrow AR2.

  From the state shown in FIG. 6C, the swinging claw 14 moves to the initial position as shown by the arrow ME3 (FIG. 6D), and the movable guide 15 moves to the initial position as shown by the arrow ME4 ( FIG. 6 (e)). Thereby, each of the swinging claw 14 and the movable guide 15 returns to the initial position.

  7 and 8 are cross-sectional views showing the operation when the Z-folding device 10 performs Z-folding on a sheet in the first embodiment of the present invention.

  Referring to FIG. 7A, each of the swinging claw 14 and the movable guide 15 is in the initial position. The transport roller pair 83 rotates with the central roller 11 and the folding roller 12 stopped. As a result, the front end of the sheet SH (an example of the target sheet) conveyed by the conveyance roller pair 83 is subjected to registration correction by the nip N1, and the sheet SH is subjected to skew correction by the nip N1.

  With reference to FIG.7 (b), the center roller 11 and the folding roller 12 start rotation. As a result, the leading edge of the sheet SH is transported to the transport path TR2a by the nip N1. A sensor SE1 (first sheet end surface detecting means) provided on the downstream side of the nip N1 detects the leading edge of the sheet SH and a predetermined time has elapsed (the sheet SH is transported to the transport path TR2a by a required distance). After), the central roller 11 and the folding roller 12 stop. The conveyance roller pair 83 continues to rotate.

  With reference to FIG. 7C, a loop is formed in the vicinity of the nip N2 of the paper SH by the rotation of the transport roller pair 83. After the loop is formed on the paper SH, the transport roller pair 83 temporarily stops.

  Referring to FIG. 7D, the swinging claw 14 moves to the paper guide position (folding position). As a result, the loop of the paper SH (the position of the first fold) is pressed by the swinging claw 14 and pushed into the nip N2. Next, the central roller 11, the folding rollers 12 and 13, and the conveyance roller pair 83 start to rotate. At this time, the central roller 11 and the folding roller 13 rotate in the direction in which the paper SH is transported to the transport path TR2b. The folding roller 12 rotates in the direction opposite to that in the case of FIG. As a result, the loop of the paper SH is caught in the nip N2, and a first fold is formed in the paper SH by the nip N2.

  Referring to FIG. 8A, a sensor SE2 (second sheet end face detecting means) provided on the downstream side of the nip N2 detects the leading end of the sheet SH and a predetermined time has elapsed (on the sheet SH). After forming the first fold), the central roller 11 and the folding rollers 12 and 13 stop. The conveyance roller pair 83 continues to rotate. As a result, a loop is formed near the nip N1 of the paper SH.

  Referring to FIG. 8B, the swinging claw 14 moves to the initial position, and the movable guide 15 moves to the folding position. As a result, the loop of the paper SH (position to be the second fold) is pressed by the movable guide 15 and is pushed into the nip N1. Next, the central roller 11 and the folding rollers 12 and 13 start to rotate. At this time, the central roller 11 and the folding roller 12 rotate in the direction in which the paper SH is transported to the transport path TR2a (the same direction as in the case of FIG. 7A). The folding roller 13 rotates in the direction opposite to that in the case of FIG. As a result, the loop of the paper SH is caught in the nip N1, and a second fold is formed on the paper SH by the nip N1.

  With reference to FIG. 8C and FIG. 8D, the overlapping portion of the paper SH due to folding passes through the nip N1, and the Z-folding is completed.

  Then, the effect of this Embodiment is demonstrated.

  FIG. 9 is a diagram showing a booklet BL1 produced when the sheets SH1 and SH2 are fed from the post inserter 50 in the first embodiment of the present invention.

  Referring to FIG. 9, here, the sheets SH1 and SH2 are arranged in the sheet feed tray 51 in a state where the sheet SH2 is superimposed on the sheet SH1. Images of pages 1 and 8 are printed on the lower surface of the paper SH1, and images of pages 2 and 7 are printed on the upper surface. Images of pages 3 and 6 are printed on the lower surface of the paper SH2, and images of pages 4 and 5 are printed on the upper surface.

  Each of the sheets SH1 and SH2 fed from the post inserter 50 arrives at the saddle unit 60 without being reversed in its traveling direction as indicated by an arrow AR2. In the saddle unit 60, the sheet SH1 is overlaid on the sheet SH2. Images of pages 1 and 8 are formed on the upper surface of the sheet SH1, and images of pages 2 and 7 are formed on the lower surface. Images of pages 3 and 6 are formed on the upper surface of the sheet SH2, and images of pages 4 and 5 are formed on the lower surface. Each of the sheets SH1 and SH2 is accommodated with its lower end facing the belt tray 72 side (left side in FIG. 9) and its upper end facing the image forming apparatus main body 2 side (right side in FIG. 9). The The sheets SH1 and SH2 are subjected to half-fold processing by the saddle unit 60, and are discharged to the belt tray 72 in the state of the booklet BL1. The booklet BL1 has the correct page order.

  FIG. 10 is a view showing a booklet BL2 produced as a comparative example of the present invention when the transport direction of the papers SH1 and SH2 fed from the post inserter 50 is reversed.

  Referring to FIG. 10, sheets SH1 and SH2 are arranged on sheet feed tray 51 in the same state as in FIG. Each of the sheets SH1 and SH2 fed from the post inserter 50 is conveyed to the main tray 71 as indicated by an arrow AR101. When the paper SH1 is on the main tray 71, images of 1 page and 8 pages are formed on the upper surface of the paper SH1, and images of 2 pages and 7 pages are formed on the lower surface. Thereafter, the sheet SH1 reaches the saddle unit 60 with its traveling direction reversed as indicated by an arrow AR102.

  In the saddle unit 60, the sheet SH1 is overlaid on the sheet SH2. Images of pages 2 and 7 are formed on the upper surface of the paper SH1, and images of pages 1 and 8 are formed on the lower surface. Images of pages 4 and 5 are formed on the upper surface of the paper SH2, and images of pages 3 and 6 are formed on the lower surface. The sheets SH1 and SH2 are subjected to half-folding processing by the saddle unit 60, and are discharged to the belt tray 72 in the state of the booklet BL2. In the booklet BL2, the page order is disordered. In the present embodiment, since the post-inserted paper passes through the transport path TR2b, it is not necessary to reverse the traveling direction, and page order disturbance such as the booklet BL2 can be suppressed.

  According to this embodiment, since the Z-folding device can be built in the post-processing device having the post insert function, the post-processing device can be downsized. In addition, each of two nips constituted by three rollers that perform Z-folding can convey a sheet to each of two different conveyance paths, and the sheet can be conveyed to an appropriate conveyance path according to the introduction destination of the sheet. Paper can be passed through. As a result, the consistency of the page order of the post-inserted sheets can be ensured while forming the branch path using the configuration originally provided in the Z-folding apparatus, and the convenience can be improved.

  [Second Embodiment]

  FIG. 11 is a cross-sectional view showing the configuration of the post-processing apparatus 1 to which the guide unit 30A is attached in the second embodiment of the present invention.

  Referring to FIGS. 5 and 11, in the first embodiment, for example, when post-processing apparatus 1 does not include post inserter 50, all sheets are conveyed through conveyance path TR2a. TR2b becomes unnecessary. As described above, when it is not necessary to transport the sheet to the transport path TR2b, the folding roller 13 may be removed, and a guide 16 that guides the sheet transported from the transport path TR1 to the nip N1 may be attached instead. The folding roller 13 and the guide 16 are exchanged by exchanging the roller unit 30 constituted by the folding roller 13, the swinging claw 14, the movable guide 15 and the like and the guide unit 30 </ b> A constituted by the guide 16. It may be broken.

  [Third Embodiment]

  FIG. 12 is a partial cross-sectional view showing the configuration of the post-processing apparatus 1 to which the conveyance path switching device 10A is attached in the third embodiment of the present invention.

  With reference to FIGS. 5 and 12, in the first embodiment, for example, when post-processing device 1 does not include Z-folding device 10 (when the user does not need the Z-folding function of post-processing device 1), Control of the pressures at the nips N1 and N2 by the post-processing control unit 109 becomes unnecessary. In this case, the motors 21 and 22 and the cams 23 and 24 (pressure contact mechanism for folding) may be removed. The removal of these members may be performed by exchanging the Z folding device 10 (an example of the first unit) and the transport path switching device 10A (an example of the second unit). The conveyance path switching device 10 </ b> A is a device that includes a central roller 11, a folding roller 12, a folding roller 13, a swinging claw 14, and a movable guide 15.

  [Others]

  The post-processing function included in the post-processing device is arbitrary. The post-processing apparatus has, for example, a punching function, a stapling process, or a tri-fold function (three areas where the areas of the three surfaces are equal) in addition to the Z-fold function (tri-fold where the areas of the two surfaces are equal). Fold) and the like.

  The present invention is not limited to the case where the post-processing apparatus includes a post inserter. For example, when the post-processing device includes another post-processing function (such as a hole punching function) on the downstream side of the sheet passing path of the Z-folding device, the paper that performs processing using the other post-processing function without performing Z-folding Is passed through one transport path (for example, transport path TR2a), and a sheet that is not Z-folded and is not subjected to processing using the other post-processing function is passed through the other transport path (for example, transport path TR2b). You may do it.

  The processing in the above-described embodiment may be performed by software or by using a hardware circuit. It is also possible to provide a program for executing the processing in the above-described embodiment, and record the program on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, or a memory card and provide it to the user. You may decide to do it. The program is executed by a computer such as a CPU. The program may be downloaded to the apparatus via a communication line such as the Internet.

  The above-described embodiment is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1,1001 Post-processing apparatus 2,1002 Image forming apparatus main body 10,1010 Z folding apparatus 10A Conveyance path switching apparatus 11 Central roller 12,13 Folding roller 14 Oscillating claw 14a Oscillating claw fulcrum 15 Movable guide 15a Movable guide fulcrum 16 Guide 21, 22 Motor 23, 24 Cam 30 Roller unit 30A Guide unit 50 Post inserter 51 Paper feed tray 52 Paper feed roller 60 Saddle unit 61, 62, 81-85 Transport roller pair 63 Folding member 64 Folding roller pair 65 Stack Unit 71 Main tray 72 Belt tray 100, 1100 Image forming apparatus 101 CPU (Central Processing Unit)
102 ROM (Read Only Memory)
103 RAM (Random Access Memory)
104 Scanner 105 Network Interface 106 Operation Panel 107 Auxiliary Storage Device 108 Image Forming Unit 109 Post Processing Control Unit 109 Post Processing Control Unit BL1, BL2 Booklet IL Inlet N1, N2 Nip SE1, SE2 Sensor SH, SH1, SH2 Paper TR0, TR1 , TR2a, TR2b, TR2c, TR3, TR4

Claims (16)

A central roller,
A first roller that forms a first nip by contacting the central roller;
A second roller that forms a second nip different from the first nip by contacting the central roller;
The center roller and the first roller fold paper at the first nip, and convey the paper to the first conveyance path via the first nip.
The central roller and the second roller fold the paper at the second nip, and transport the paper to a second transport path different from the first transport path via the second nip. A post-processing device. First conveying means for conveying a target sheet to be Z-folded to the first conveying path by the first nip;
A first folding unit configured to form a first fold on the target sheet by the second nip after the target sheet is transported to the first transport path by a predetermined distance by the first transport unit; ,
And a second folding unit for forming a second fold on the target sheet by the first nip after the first fold is formed on the target sheet by the first folding unit. Item 4. A post-processing apparatus according to item 1. The first transport unit rotates each of the central roller and the first roller in a direction of transporting the target paper to the first transport path,
The first folding means rotates the central roller in a direction opposite to the direction of rotation by the first conveying means, and the second folding paper is conveyed in the direction of conveying the target paper to the second conveying path. Rotate the roller,
The second folding means rotates the central roller in a direction in which the target paper is conveyed to the first conveyance path, and the second folding means is in a direction opposite to the direction of rotation by the first folding means. The post-processing apparatus according to claim 2, wherein the roller is rotated. An inlet for introducing paper printed by the image forming apparatus main body into the post-processing apparatus;
A paper feed mechanism for introducing paper into the post-processing apparatus without passing through the introduction port from the outside of the post-processing apparatus and the image forming apparatus main body;
Printing paper transporting means for transporting the paper that is not Z-folded introduced from the introduction port to the first transport path via the first nip;
The apparatus according to claim 1, further comprising an external sheet conveying unit that conveys the sheet that is not Z-folded introduced by the sheet feeding mechanism to the second conveying path via the second nip. The post-processing apparatus in any one. The first conveyance path and the second conveyance path merge to form a third conveyance path,
A reversing device that does not perform Z-folding introduced from the introduction port, and reverses the traveling direction of the paper that is being conveyed on the first conveyance path;
A half-folding device that folds the paper introduced through the third conveyance path in a central portion;
A discharge tray that discharges the paper after being folded in the middle by the center folding device;
5. The post-processing according to claim 4, wherein the half-folding device accommodates a sheet to be folded in the center portion in a state where a lower end portion of the sheet to be folded in the center portion faces the discharge tray side. apparatus.   The post-processing apparatus according to claim 5, wherein the half-folding device is provided below the second nip.   The post-processing apparatus according to claim 4, wherein the paper feeding mechanism is detachable.   The post-processing apparatus according to claim 1, further comprising a switching member that switches a paper conveyance path between the first conveyance path and the second conveyance path.   The post-processing device according to claim 8, wherein the switching member presses a portion of the target paper that becomes the first fold when forming a first fold on the target paper that is a target of Z-folding.   The pressure of the first nip when the sheet is Z-folded at the first nip is greater than the pressure of the first nip when the sheet that is not Z-folded is transported to the first transport path. The post-processing apparatus according to any one of claims 1 to 9, further comprising first pressure control means for increasing the pressure.   The post-processing apparatus according to claim 10, wherein the first pressure control means is detachable.   The first unit including the first pressure control means and a switching member that switches a paper conveyance path between the first conveyance path and the second conveyance path includes the first pressure control means. The post-processing apparatus according to claim 11, wherein the post-processing apparatus is replaceable with a second unit including the switching member.   The pressure of the second nip when the sheet is Z-folded at the second nip is greater than the pressure of the second nip when the sheet that is not Z-folded is transported to the second transport path. The post-processing apparatus according to any one of claims 1 to 12, further comprising a second pressure control means for increasing the pressure.   The first transport path is a transport path for discharging a sheet to a side surface of the post-processing device opposite to a side surface of the post-processing device on which the image forming apparatus main body is provided. The after-treatment device described in   The post-processing device according to claim 1, wherein when the sheet is not conveyed to the second conveyance path, the second roller is replaceable with a guide that guides the sheet to the first nip. . An image forming apparatus main body for printing on paper;
An image forming apparatus comprising: the post-processing device according to claim 1, wherein post-processing is performed on a sheet printed by the image forming device main body.

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