JP2012126531A - Sheet processing device, image forming apparatus, method for controlling the sheet processing device, and program for controlling the sheet processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing device capable of properly performing sheet processing for various kinds of sheets mutually different in stiffness.SOLUTION: In the sheet processing device having a slanted processing tray, a plurality of sheets are positioned by a stopper and accumulated in the processing tray, so as to process the sheets. Depending on sizes and flexibilities of the sheets, the position of the stopper is adjusted. In processing the sheet processing (YES in S11), a control part of the sheet processing device makes the stopper move to a thin paper position (S17) if the sheet has a property easy to bend and the number of the accumulated sheets is not more than a predetermined number (YES in S13, NO in S15), while making it move to a normal position (S19) if not. Also, when the sheets are accumulated in the processing tray (S21, S23), filing processing is performed (S25). Since the thin paper position is set higher than the normal position, the sheets are processed at the appropriate position even though the sheets are bent while the sheet is easy to bend and the accumulated number is few.

Description

  The present invention relates to a sheet processing apparatus, an image forming apparatus, a control method for a sheet processing apparatus, and a control program for a sheet processing apparatus, and in particular, a sheet processing apparatus that executes processing of a plurality of sheets stacked in an inclined state, The present invention relates to an image forming apparatus, a sheet processing apparatus control method, and a sheet processing apparatus control program.

  For example, it is attached to an image forming apparatus (MFP (Multi Function Peripheral), facsimile apparatus, copying machine, printer, etc.) having a scanner function, a facsimile function, a copying function, a printer function, a data communication function, and a server function. There is a sheet processing apparatus that performs sheet processing (for example, binding processing or folding processing) on a sheet that is used and conveyed. As such a sheet processing apparatus, there is an apparatus in which a plurality of sheets conveyed sequentially are overlapped and combined, and a saddle stitching process, a center folding process, or the like is performed on the combined sheets.

  In such a sheet processing apparatus that performs sheet processing on a plurality of sheets, the plurality of sheets are stacked on a stacking unit provided in the sheet processing apparatus. The loading part is inclined. When the front end of the sheet conveyance direction comes into contact with a stopper provided below the stacking unit, the sheets are stacked on the stacking unit in an inclined state, and the sheets are collected as a sheet bundle.

  In the following Patent Document 1, in a sheet processing apparatus for positioning a plurality of sheets in contact with a stopper and binding the center of the sheet bundle in the conveying direction, the sheet is provided with a roller that conveys the sheet while nipping the sheet. It is disclosed that the sheet is separated from the sheet immediately before coming into contact with the sheet. This sheet processing apparatus prevents the occurrence of over-conveyance due to the force that conveys the sheet after the sheet abuts against the stopper, and prevents the sheet from buckling due to over-conveyance.

  In the following Patent Document 2, in a sheet processing apparatus that stacks a plurality of sheets on a vertical sheet path and binds the center of the sheet bundle in the conveyance direction, the sheet is bent in a direction orthogonal to the conveyance direction. It has been disclosed to prevent buckling of the seat by generating a waist.

JP-A-11-322163 JP-A-11-322179

  By the way, in the paper processing apparatus having the mechanism as described in Patent Document 1 as described above, it is possible to prevent the paper from buckling (bending) due to so-called over conveyance, but the paper is caused by its own weight. Flexing is not prevented. The deflection due to the weight of the paper mainly occurs due to the following causes. That is, the stacking portion is inclined and the stacking portion is formed so as to be wide in the thickness direction of the sheet, so that a plurality of sheets can be introduced. In such an inclined stacking section, a space for the sheet to bend is always formed, and therefore it is not possible to prevent the sheet having a relatively low waist from being bent by its own weight.

  When the sheet bends in this way, the distance between the leading edge and the trailing edge in the sheet conveyance direction becomes smaller than when no deflection occurs. For this reason, when the deflection due to the weight of the sheet is generated, if the binding process or the folding process is performed, the position where the process is originally performed may be shifted from the position where the process is originally performed.

  Regarding such a problem, in the sheet processing apparatus described in Patent Document 2, a raised portion for bending the paper is provided in the stacking portion on which the paper is stacked. However, when the raised portions are provided in this way, the number of sheets that can be stacked in the stacking portion is reduced. Further, it is necessary to convey the sheet to a predetermined position while curving it at the raised portion, and there is a high possibility that a conveyance failure of the sheet will occur.

  The present invention has been made to solve such a problem, and is a sheet processing apparatus, an image forming apparatus, and a sheet that can appropriately process various types of sheets having different stiffness. It is an object of the present invention to provide a control method for a processing apparatus and a control program for a sheet processing apparatus.

  In order to achieve the above object, according to one aspect of the present invention, a sheet processing apparatus includes: a conveyance unit that conveys a sheet; a stacking unit that stacks sheets conveyed by the conveyance unit; And a stopper for positioning the vertical position of the paper stacked on the stacking unit, a processing unit for processing paper on the paper positioned by the stopper and stacked on the stacking unit, and stacking on the stacking unit Acquired by a first acquisition unit that acquires information on the size of the paper to be printed, a second acquisition unit that acquires information on the flexibility of the paper stacked on the stacking unit, and the first acquisition unit A stopper control unit that performs control related to the position of the stopper when paper processing is performed by the processing unit according to the information and the information acquired by the second acquisition unit.

  Preferably, the stopper control unit is configured such that when the second acquisition unit acquires information regarding that the paper stacked on the stacking unit is easily bent, the stopper does not acquire information on the same size paper. Control is performed so as to be positioned at the second position above the first position at which the stopper is positioned.

  Preferably, each of the first position and the second position is a position set in advance corresponding to information on the size and the flexibility of the sheets stacked on the stacking unit.

  Preferably, when the second acquisition unit acquires information on the fact that the sheets stacked on the stacking unit are easily bent, the stopper control unit determines the degree of flexibility of the sheets for the same size of sheets. In response to this, control for changing the second position is performed.

  Preferably, the stopper control unit performs control according to the number of sheets stacked on the stacking unit.

  Preferably, when the second acquisition unit acquires information related to the fact that the paper stacked on the stacking unit is easily bent, the stopper control unit has a predetermined number or more of sheets stacked on the stacking unit. The control is performed so that the stopper is positioned at the first position.

  Preferably, the stopper control unit is configured to process the sheet in a state where the stopper is in the second position when the second acquisition unit acquires information regarding that the sheet stacked on the stacking unit has a property of being easily bent. When all sheets are stacked on the stacking unit and the number of sheets stacked on the stacking unit is equal to or greater than a predetermined number, control for moving the stopper to the first position is started.

  Preferably, the stopper control unit has a predetermined number of sheets in the stacking unit in a state where the stopper is in the second position when the second acquisition unit acquires information regarding that the paper stacked on the stacking unit is easily bent. Control is performed to move the stopper to the first position from the point of time when sheets are stacked beyond the limit.

  Preferably, the stopper control unit is configured such that when the second acquisition unit acquires information regarding that the sheets stacked on the stacking unit are easily bent, the sheet is loaded in the state where the stopper is in the second position. Each time one sheet is stacked, the stopper is moved stepwise toward the first position, and the stepwise movement control is performed when the number of sheets stacked on the loading section reaches a predetermined number. Thus, the stopper is positioned at the first position and the movement is completed.

  Preferably, the information on the flexibility of the paper loaded on the stacking unit is information on at least one of the basis weight of the paper and the type of the paper.

  Preferably, the sheet processing apparatus includes a holding unit that holds information preset by the user regarding the sheet, a basis weight detection unit that detects information about the basis weight of the sheet, and a thickness detection unit that detects information about the sheet thickness. And a waist detection unit that detects information about the strength of the waist of the paper, and the second acquisition unit is at least one of the holding unit, the basis weight detection unit, the thickness detection unit, and the waist detection unit. The information on the flexibility of the paper loaded on the stacking unit is acquired from one.

  According to another aspect of the present invention, an image forming apparatus includes an image forming apparatus main body and any one of the above-described paper processing apparatuses, and the paper processing apparatus supplies paper to a sheet sent from the image forming apparatus main body. Dispose after processing.

  According to still another aspect of the present invention, a conveyance unit that conveys a sheet, a stacking unit that stacks sheets conveyed by the conveyance unit in an inclined state, and is arranged so as to be displaceable along the stacking unit. A control method for a paper processing apparatus comprising a stopper for positioning a vertical position of a paper loaded on the paper and a processing unit for processing paper on the paper positioned by the stopper and stacked on the stacking unit is provided on the stacking unit. Acquired by a first acquisition step of acquiring information on the size of the paper to be printed, a second acquisition step of acquiring information on the flexibility of the paper stacked on the stacking unit, and the first acquisition step A stopper control step for controlling the position of the stopper when paper processing is performed by the processing unit according to the information and the information acquired by the second acquisition step.

  According to still another aspect of the present invention, a conveyance unit that conveys a sheet, a stacking unit that stacks sheets conveyed by the conveyance unit in an inclined state, and is arranged so as to be displaceable along the stacking unit. A control program for a paper processing apparatus that includes a stopper for positioning the vertical position of the paper loaded on the paper and a processing unit that performs paper processing on the paper that is positioned by the stopper and loaded on the stacking unit is loaded on the stacking unit. Acquired by a first acquisition step of acquiring information on the size of the paper to be printed, a second acquisition step of acquiring information on the flexibility of the paper stacked on the stacking unit, and the first acquisition step A stopper control step for controlling the position of the stopper when paper processing is performed by the processing unit according to the information and the information acquired in the second acquisition step. To be executed by a computer.

  According to these inventions, the position of the stopper when paper processing is performed by the processing unit is controlled according to the size of the paper loaded on the stacking unit and the flexibility. Accordingly, it is possible to provide a paper processing apparatus, an image forming apparatus, a control method for the paper processing apparatus, and a control program for the paper processing apparatus that can appropriately perform paper processing on various types of paper having different stiffness. Can do.

1 is a side view showing an image forming apparatus using a sheet processing apparatus according to an embodiment of the present invention. 1 is a block diagram illustrating an image forming apparatus. It is a side view showing a paper processing device. It is a side view which shows a saddle stitching process part. It is a sectional side view which shows a saddle stitching process part. It is a table | surface which shows an example of the normal position and thin paper position which were preset about the stacking position of a stopper. It is a flowchart which shows an example of the control which changes the position of the stopper when a binding process and a folding process are performed. It is a flowchart which shows the 1st modification of the control which changes the position of a stopper in case the paper has the property which bends easily. 12 is a flowchart illustrating a second modification of control for changing the position of a stopper when a sheet has a property of being easily bent. 12 is a flowchart illustrating a third modification of control for changing the position of a stopper when a sheet has a property of being easily bent. FIG. 6 is a side view of a saddle stitching processing unit having a deflection sensor that detects the presence or absence of deflection of a sheet. FIG. 10 is a diagram illustrating a case where sheets stacked in the saddle stitching processing unit are bent. It is a figure explaining the saddle stitching process part in the other modification of a paper processing apparatus.

  Hereinafter, a sheet processing apparatus according to an embodiment of the present invention will be described.

  [Overview]

  The sheet processing apparatus is used together with an image forming apparatus main body such as an MFP (Multi Function Peripheral) having a scanner function, a copying function, a printer function, a facsimile function, a data communication function, and a server function. Here, for example, the scanner function is a function of reading an image of a set original and storing it in an HDD (Hard Disk Drive) or the like. The copying function is a function for printing (printing) it on a sheet (sheet) or the like. The function as a printer is a function for printing on a sheet based on an instruction received from an external terminal such as a PC. The facsimile function is a function for receiving facsimile data from an external facsimile machine and storing it in an HDD or the like. The data communication function is a function for transmitting / receiving data to / from a connected external device. The server function is a function that allows a plurality of users to share data stored in the HDD or the like. The user can use the image forming apparatus main body and the sheet processing apparatus together as one image forming apparatus.

  The sheet processing apparatus sequentially stacks sheets sent one by one from the image forming apparatus main body on the processing tray, and performs sheet processing on the plurality of stacked sheets. As the paper processing performed by the paper processing apparatus, there is one in which a plurality of sheets are stacked one by one on a processing tray, stapled or the like, and then discharged as a booklet. In the present embodiment, the paper processing is executed after the position of the stopper for positioning the paper is adjusted according to the size of the paper loaded on the processing tray and the flexibility. Thus, it is possible to appropriately perform a good-looking paper process on various papers of different types (thin paper, plain paper, thick paper, etc.).

  [Embodiment]

  FIG. 1 is a side view showing an image forming apparatus using a sheet processing apparatus according to an embodiment of the present invention.

  In the figure, the sheet processing apparatus 1 is used together with the image forming apparatus main body 110. The user can use the sheet processing apparatus 1 as the image forming apparatus 100 including the image forming apparatus main body 110. In other words, it can be said that the image forming apparatus 100 is the sheet processing apparatus 1 and has an image forming function by the image forming apparatus main body 110.

  [Configuration of Image Forming Apparatus Main Body 110]

  The image forming apparatus main body 110 includes a control unit 120, an image forming unit 130, an image reading unit 140, and the like.

  The control unit 120 controls the operation of each unit of the image forming apparatus main body 110. A more specific configuration of the control unit 120 will be described later.

  For example, the image forming unit 130 forms an image on the sheet while conveying the sheet loaded in the sheet cassette 131 inside the image forming apparatus main body 110. The image forming unit 130 forms an image by, for example, an electrophotographic method or an inkjet method. The sheet on which the image is formed by the image forming unit 130 is sent out from the image forming apparatus main body 110 toward the paper discharge tray 135 provided on the upper part of the image forming apparatus main body 110 by the main body discharge roller 133.

  The image reading unit 140 reads a document placed at a predetermined position of the image reading unit 140 with an imaging device or the like, and outputs it as image data. The image reading unit 140 can read a document while conveying the document using, for example, an ADF (Auto Document Feeder). Further, the image reading unit 140 can scan a document placed on a document table provided on the upper surface of the image forming apparatus main body 110 with an imaging device and read the document.

  FIG. 2 is a block diagram illustrating the image forming apparatus 100.

  Referring to the figure, image forming apparatus main body 110 further includes an operation unit 111 and a sheet processing apparatus connection unit 117.

  The control unit 120 includes a CPU 121, a ROM 123, a RAM 125, an HDD 127, and a network control unit 129. The control unit 120 is connected to the system bus together with the operation unit 111, the sheet processing apparatus connection unit 117, the image forming unit 130, the image reading unit 140, and the like. Thereby, the control unit 120 and each unit of the image forming apparatus main body 110 are connected so as to be able to transmit and receive signals.

  The HDD 127 stores job data sent from the outside via the network control unit 129, image data read by the image reading unit 140, and the like. The HDD 127 stores setting information of the image forming apparatus main body 110, a control program (program) 127a for performing various operations of the image forming apparatus main body 110, and the like. The HDD 127 can store a plurality of jobs transmitted from one client PC or a plurality of client PCs.

  For example, the network control unit 129 is configured by combining a hardware unit such as a NIC (Network Interface Card) and a software unit that performs communication using a predetermined communication protocol. The network control unit 129 connects the image forming apparatus main body 110 to an external network such as a LAN. As a result, the image forming apparatus main body 110 can communicate with an external apparatus such as a client PC connected to the external network. The image forming apparatus main body 110 can receive a print job and transmit image data read by the image reading unit 140 via an external network. The network control unit 129 may be configured to be connectable to an external network by wireless communication. The network control unit 129 may be, for example, a USB (Universal Serial Bus) interface. In this case, the network control unit 129 enables communication between the external apparatus connected via the communication cable and the image forming apparatus main body 110.

  The CPU 121 controls various operations of the image forming apparatus main body 110 by executing a control program 127a or the like stored in the ROM 123, RAM 125, HDD 127, or the like. When an operation signal is transmitted from the operation unit 111 or an operation command is transmitted from an external PC or the like, the CPU 121 executes a predetermined control program 127a in response thereto. Accordingly, a predetermined function of the image forming apparatus main body 110 is executed in accordance with the operation of the operation unit 111 by the user.

  The ROM 123 is, for example, a flash ROM (Flash Memory). The ROM 123 stores data used for operating the image forming apparatus main body 110. Like the HDD 127, the ROM 123 may store various control programs, function setting data of the image forming apparatus 100, and the like. The CPU 121 reads data from the ROM 123 and writes data to the ROM 123 by performing predetermined processing. The ROM 123 may be non-rewritable.

  The RAM 125 is a main memory of the CPU 121. The RAM 125 is used to store data necessary when the CPU 121 executes the control program 127a.

  The operation unit 111 is disposed on the housing of the image forming apparatus main body 110 so that it can be operated by the user. The operation unit 111 includes a plurality of operation buttons that can be pressed by the user and a display panel 113. The display panel 113 is, for example, an LCD (Liquid Crystal Display) provided with a touch panel. The display panel 113 displays a guidance screen to the user or displays an operation button to accept a touch operation from the user. The display panel 113 performs display under the control of the CPU 121. When the operation button or the display panel 113 is operated by the user, the operation unit 111 transmits an operation signal or a predetermined command corresponding to the operation to the CPU 121. That is, the user can cause the image forming apparatus 100 to execute various operations by operating the operation unit 111. The control unit 120 can accept user operation input via the operation unit 111.

  The paper processing device connection unit 117 is provided so as to be connectable to the connection unit 17 provided in the paper processing device 1 via, for example, a cable or a connector. The paper processing device connection unit 117 is configured by combining a hardware unit and a software unit for communicating with the paper processing device 1 using a predetermined communication protocol. By connecting the sheet processing apparatus connection unit 117 to the connection unit 17, the image forming apparatus main body 110 can operate as one image forming apparatus 100 in conjunction with the sheet processing apparatus 1.

  [Configuration of Paper Processing Apparatus 1]

  Returning to FIG. 1, the sheet processing apparatus 1 roughly includes a horizontal conveyance unit 2, a processing unit main body 3, a sheet tray 4, a booklet tray 5, and a control unit 10. The processing unit main body 3 includes, for example, a side stitching processing unit 7 that performs a side stitching process and a saddle stitching processing unit 8 that performs a saddle stitching process. The sheet is conveyed by the horizontal conveyance unit 2 and the processing unit main body 3 and conveyed to these processing units 7 and 8.

  The horizontal conveyance unit 2 introduces the paper sent from the main body discharge roller 133 of the image forming apparatus main body 110 into the paper processing apparatus 1 and conveys the paper to the subsequent processing unit main body 3.

  The processing unit main body 3 performs paper processing such as punching processing, sorting processing, binding processing, folding processing, and the like on the paper delivered from the horizontal conveyance unit 2 and discharges the paper to the paper tray 4 or the booklet tray 5. The punching process is, for example, a process of making a hole for each sheet at a predetermined position of each sheet, or a process of making a hole for a plurality of sheets. The sorting process is, for example, a process of collecting a plurality of sheets in different positions or different trays for each copy so that each portion can be easily distinguished. As described later, the binding process is a process of binding a plurality of sheets together with staples. The folding process is a process of folding a sheet into two or three. The paper that has undergone paper processing in the side stitching processing unit 7 is discharged onto the paper tray 4. The paper that has undergone paper processing by the saddle stitching processing unit 8 is discharged onto the booklet tray 5.

  The control unit 10 controls the operation of each unit of the sheet processing apparatus 1 as will be described later.

  With reference to FIG. 2, the sheet processing apparatus 1 further includes a connection unit 17 and a drive unit 19.

  The control unit 10 includes a CPU 11, a ROM 13, and a RAM 15. The control unit 10, the connection unit 17, and the drive unit 19 are all connected to the system bus and can communicate with each other. Various sensors described later are also connected to the system bus and can communicate with the control unit 10 and the like.

  The ROM 13 is, for example, a flash ROM (Flash Memory). The ROM 13 stores setting information for the sheet processing apparatus 1 and data used for operating the sheet processing apparatus 1. Further, the ROM 13 stores a control program (program) 13a for performing various operations of the sheet processing apparatus 1.

  The RAM 15 is a main memory of the CPU 11. The RAM 15 is used for storing data necessary when the CPU 11 executes the control program 13a.

  The CPU 11 controls various operations of the sheet processing apparatus 1 by executing a control program 13a stored in the ROM 13 or the like. The CPU 11 reads data from the ROM 13 and writes data to the ROM 13 by performing predetermined processing. The ROM 13 may be non-rewritable.

  The drive unit 19 is, for example, a motor including drive motors 61 and 62 described later. The drive unit 19 operates based on the control of the control unit 10 and drives the horizontal transport unit 2 and the processing unit main body 3.

  The connection unit 17 can be connected to the paper processing device connection unit 117 of the image forming apparatus main body 110. The connection unit 17 includes a hardware unit capable of connecting a cable, a connector, or the like used to connect to the paper processing apparatus connection unit 117, and a software unit for communicating with the image forming apparatus main body 110 using a predetermined communication protocol. Are combined.

  In a state where the connection unit 17 is connected to the sheet processing apparatus connection unit 117, the control unit 10 can communicate with the control unit 120 of the image forming apparatus main body 110. Information about the operation status of the image forming apparatus main body 110 is transmitted from the control unit 120 to the control unit 10. The information to be transmitted includes, for example, information related to the paper ejected from the image forming apparatus main body 110 and carried into the paper processing apparatus 1. The control unit 10 receives information transmitted from the control unit 120, drives the drive unit 19 in accordance with the information, and controls the operation of each unit of the sheet processing apparatus 1. In addition, the control unit 10 transmits information about the operation status of the sheet processing apparatus 1 to the control unit 120. As a result, the image forming apparatus main body 110 and the paper processing apparatus 1 are linked. For example, the control unit 120 changes the image formation timing of a plurality of sheets so that the sheet processing apparatus 1 appropriately performs sheet processing, and the sheets are conveyed to the sheet processing apparatus 1 at appropriate intervals. Can be controlled.

  The control unit 10 is operable based on an instruction input from the operation unit 111 of the image forming apparatus main body 110 or an instruction sent from an external device connected to the image forming apparatus main body 110. The sheet processing apparatus 1 may have an operation panel that can be operated by a user, and may be operable based on an instruction input to the operation panel.

  FIG. 3 is a side view showing the sheet processing apparatus 1.

  Referring to the drawing, the horizontal transport unit 2 includes a horizontal transport path 21 that is a paper transport path, three transport rollers 22, 23, and 24, and sensors 25 and 26 that detect the paper.

  The horizontal conveyance path 21 is disposed so as to be connected substantially horizontally from the paper carry-in port 2 a to the paper discharge port 2 b to the processing unit main body 3. The three transport rollers 22, 23, 24 are provided along the horizontal transport path 21 in order from the upstream side of the horizontal transport path 21 (the transport inlet 2 a side). The paper discharged from the main body discharge roller 133 of the image forming apparatus main body 110 is introduced into the horizontal transport unit 2 from the carry-in entrance 2a. The introduced paper is sent to the processing unit main body 3 by driving the transport rollers 22 to 24.

  The processing unit main body 3 roughly includes a first transport path 31, a second transport path 32, and a third transport path 33 as paper transport paths. The first transport path 31 is disposed so as to connect substantially horizontally from the paper inlet 3 a provided at the top of the processing unit main body 3 to the start point of the second transport path 32. The second transport path 32 is disposed so as to connect the end point of the first transport path 31 to the discharge port on the paper tray 4 substantially horizontally. The vicinity of the part (upstream side) connected to the first conveyance path 31 in the second conveyance path 32 is a switchback point 34. The third conveyance path 33 is arranged to convey the sheet from the end point of the first conveyance path 31, that is, the start point of the second conveyance path 32, to the saddle stitching processing unit 8 disposed at the lower part of the processing unit main body 3. Yes. That is, the third transport path 33 is a paper transport path from the switchback point 34 to the lower part of the processing unit main body 3.

  The first conveyance path 31 is provided with a registration sensor 35, a registration roller 36, a punch 37, and an intermediate roller 38 from the upstream side. The registration sensor 35 detects the paper transported to the first transport path 31. The registration roller 36 adjusts the conveyance timing of the conveyed paper and starts conveyance again at a predetermined timing. The punch 37 makes a hole (perforation processing) at a predetermined position of the conveyed paper. The intermediate roller 38 conveys the sheet to the second conveyance path 32.

  A switchback sensor 40 is provided at the switchback point 34 on the upstream side of the second transport path 32. In addition to the switchback sensor 40, the second conveyance path 32 is provided with a storage sensor 41 and a storage roller 42 from the upstream side. A discharge roller 43 is provided on the downstream end of the second conveyance path 32, that is, on the sheet tray 4 side. The switchback sensor 40 and the storage sensor 41 each detect the presence / absence of a sheet to be conveyed. The accommodation roller 42 can be rotated forward and backward. That is, the accommodation roller 42 can transport the paper to the paper tray 4 or in the reverse direction. The sheet in the second conveyance path 32 is conveyed to the third conveyance path 33 when the accommodation roller 42 is reversed. The discharge roller 43 can discharge or not discharge the paper by bringing the pair of rollers into contact with each other or separating them.

  Here, the side stitching processing unit 7 is disposed in the vicinity of the second conveyance path 32. The side stitching processing unit 7 includes a side stitching processing tray 70 inclined so that an upper end portion thereof is close to the discharge roller 43, a storage belt 71 arranged along the side stitching processing tray 70, and a side stitching processing tray 70. It has a main processing tray sensor 72 that detects a sheet that is positioned, and a flat binding stapler 73 positioned at the lower end of the flat binding processing tray 70. An accommodation upper paddle 74 is disposed above the vicinity of the upper end side of the flat stitching processing tray 70. An accommodation lower paddle 75 is provided above the vicinity of the lower end portion of the flat stitching processing tray 70.

  The third transport path 33 is provided with a switchback roller 44, a saddle carry-in roller 45, and a saddle carry-in sensor 46 from the upstream side (switchback point 34 side). A portion of the third conveyance path 33 on the downstream side of the saddle carry-in sensor 46 is located inside the saddle stitching processing unit 8. The switchback roller 44 conveys the sheet located in the second conveyance path 32 along the third conveyance path 33 when the accommodation roller 42 is reversed and introduced into the third conveyance path 33. The saddle carry-in roller 45 conveys the sheet to the saddle stitching processing unit 8. The saddle carry-in sensor 46 detects the paper conveyed to the saddle stitching processing unit 8.

  In the saddle stitching processing unit 8, a saddle stitching processing tray (an example of a stacking unit) 80 is disposed along the third conveyance path 33. In the vicinity of the saddle stitching processing tray 80, a stopper 81, a stopper home sensor 82, a stapler 83, alignment plates 84 and 85, a folding knife 86, a first paper detection sensor 87, and a second paper detection sensor 88, Is provided. Above the saddle stitching processing tray 80, a saddle upper paddle 89a is provided on the upstream side of the third conveyance path 33, and a saddle lower paddle 89b is provided on the downstream side. In the saddle stitching processing unit 8, a pair of folding rollers 90 are disposed so as to face the folding knife 86. The folding roller 90 is disposed above the booklet tray 5. A booklet tray full detection sensor 91 and a booklet tray empty detection sensor 92 are disposed nearer the outside of the sheet processing apparatus 1 than the folding roller 90.

  As will be described later, the stopper 81 is arranged so as to be displaceable in the vertical direction (the arrow Y direction in the figure) along the saddle stitching processing tray 80. The folding knife 86 is disposed so as to be displaceable in a direction substantially perpendicular to the saddle stitching processing tray 80 (in the direction of arrow X in the figure).

  FIG. 4 is a side view showing the saddle stitching processing unit 8.

  Referring to the figure, the saddle stitching processing tray 80 is configured to incline from the upper right side to the lower left side in the figure in a state where the image forming apparatus 100 is placed on a substantially horizontal floor shape. The sheet is conveyed to the saddle stitching processing tray 80 from above the saddle stitching processing tray 80 (from the upper right side in the figure) as indicated by an arrow T in the figure. The sheets are stacked (stacked) on the saddle stitching processing tray 80 in an inclined state. That is, the sheet is stacked on the saddle stitching processing tray 80 with the leading end in the transport direction positioned on the lower left side in the drawing and the trailing end positioned on the upper right side in the drawing and substantially perpendicular to the paper surface. .

  The stapler 83 is divided into two parts, a loading part 83a on the front side (left side in the figure) and a clincher part 83b on the back side (right side in the figure) of the saddle stitching processing tray 80. The loading portion 83a has a mechanism for driving staples toward the clincher portion 83b. Staples (stapler staples) are loaded on the loading portion 83a. The clincher portion 83b has a clincher (not shown) that bends the leading end portion of the staple driven out from the loading portion 83a. The stapler 83 performs the binding process by driving staples from the loading unit 83a toward the sheets stacked on the saddle stitching processing tray 80, and bending the staples penetrating the sheets by the clincher unit 83b.

  The saddle stitching processing unit 8 further includes a knife drive motor 61, a stopper drive motor 62, and a stopper drive belt 63.

  The knife drive motor 61 displaces the folding knife 86 toward the folding roller 90. The folding knife 86 has a sharp straight-blade tip. The folding knife 86 folds the sheet by abutting the tip of the folding knife 86 against the sheet bundle and sandwiching the folded portion between the folding rollers 90.

  The stopper drive motor 62 rotates the stopper drive belt 63. The stopper driving belt 63 is a belt arranged in an annular shape on the back side (lower right side in the drawing) of the saddle stitching processing tray 80 so that the vertical direction is the longitudinal direction along the saddle stitching processing tray 80. A stopper 81 is attached to a part of the stopper driving belt 63. When the stopper drive motor 62 is driven and the stopper drive belt 63 rotates, the stopper 81 is displaced along the saddle stitching processing tray 80 accordingly. That is, the stopper 81 is disposed so as to be displaced in the vertical direction along the saddle stitching processing tray 80. The stopper drive motor 62 is, for example, a stepping motor, and the control unit 10 accurately obtains the current position of the stopper 81 by calculating the amount of displacement of the stopper 81 from the home position, etc. Can be displaced. For example, the controller 10 may be configured to control the position of the stopper 81 using a stopper drive motor that is a DC motor and an encoder.

  In the present embodiment, when the sheet processing is performed by the saddle stitching processing unit 8, the stopper 81 is displaced to an appropriate position at any time as described later. This control is performed by the control unit 10 of the sheet processing apparatus 1. That is, the control unit 10 appropriately drives the stopper drive motor 62 to control the position of the stopper 81.

  The saddle stitching processing unit 8 further includes a three-fold mechanism 93 and a three-fold roller 94. By using the three-fold mechanism 93 and the three-fold roller 94 in addition to the folding knife 86 and the folding roller 90, the saddle stitching processing unit 8 can perform so-called three-folding as the sheet processing.

  [Description of paper processing]

  Paper processing in the paper processing apparatus 1 is performed based on the control of the control unit 10. The control unit 10 appropriately executes designated sheet processing in accordance with the instruction input content from the user via the operation unit 111 of the image forming apparatus main body 110 or the like. In other words, the control unit 10 receives an instruction input from the user via the operation unit 111 of the image forming apparatus main body 110 via the control unit 120 of the image forming apparatus main body 110, and the control unit 10 of the sheet processing apparatus 1 according to the received content. Control the behavior.

  The sheet processing apparatus 1 sequentially conveys sheets sent one by one from the image forming apparatus main body 110 on the conveyance paths 21, 31 to 33 and stacks them on the side stitching processing tray 70 or the saddle stitching processing tray 80. The side stitching processing unit 7 or the saddle stitching processing unit 8 performs sheet processing for each bundle of a plurality of sheets stacked on the processing trays 70 and 80, and then discharges the sheets.

  The side stitching processing unit 7 stacks the conveyed sheets one by one on the side stitching processing tray 70 and stitches a predetermined number of sheets with the side stitching stapler 73 to form a booklet. The side-bound booklet is discharged onto the paper tray 4.

  That is, returning to FIG. 3, in the side stitching processing unit 7, the registration roller 36, the intermediate roller 38, and the accommodation roller 42 are driven, and the sheets fed one by one from the horizontal transport unit 2 are transported toward the paper tray 4. The When the trailing edge of the sheet passes through the accommodation roller 42, driving of the accommodation upper paddle 74, the accommodation lower paddle 75, and the accommodation belt 71 is started, and the sheets are stacked on the side stitching processing tray 70. In parallel with the sheet stacking operation, a side-stitch alignment plate (not shown) is operated to perform an alignment operation in the sheet width direction. In this way, when the operations up to stacking and aligning the final sheets of a plurality of sheets in the set of sheet bundles are completed, the flat binding stapler 73 is driven, and the flat binding is performed at a predetermined position of the paper. When the side stitching operation is completed, the discharge roller 43 is pressed and driven, and the paper subjected to the side stitching processing is ejected from the side stitching processing tray 70 to the paper tray 4.

  For example, the saddle stitching processing unit 8 moves the stopper 81 to a predetermined sheet storage position, collects a plurality of sheets, and performs saddle stitching with the stapler 83 (binding process). Then, the folding knife 86 and the folding roller 90 fold the sheet in the middle (folding process) to form a plurality of sheets into a booklet shape. A plurality of booklet sheets are discharged to the booklet tray 5.

  When the sheet processing is performed in the saddle stitching processing unit 8, the sheet sequentially follows the horizontal transport path 21, the first transport path 31, the second transport path 32, and the third transport path 33 to the saddle stitch processing tray 80. To reach. The conveyance of the sheet to the saddle stitching processing unit 8 is performed by switching back the sheets sent one by one from the horizontal conveyance unit 2 to the processing unit main body 3. The switchback is performed under the control of the control unit 10. That is, the accommodation roller 42 is decelerated and stopped immediately after the trailing edge of the sheet conveyed to the second conveyance path 32 passes through the switchback sensor 40. After the accommodation roller 42 is stopped, when the accommodation roller 42 is driven in a direction opposite to that during conveyance, the sheet is conveyed to the third conveyance path 33. When the switchback roller 44 and the saddle carry-in roller 45 are driven in the direction indicated by the arrows in the drawing, the sheet is conveyed to the saddle stitching processing unit 8.

  When the leading edge of the sheet reaches the saddle carry-in sensor 46, the saddle upper paddle 89a and the saddle lower paddle 89b are driven, and the sheets are stacked on the saddle stitching processing tray 80. The sheet is supported by the stopper 81 in a state where the front end of the sheet in the conveyance direction is in contact with the stopper 81. That is, the stopper 81 positions the vertical position of the sheets stacked on the saddle stitching processing tray 80. With the sheet positioned by the stopper 81, sheet processing by the saddle stitching processing unit 8 is performed.

  FIG. 5 is a side sectional view showing the saddle stitching processing unit 8.

  The figure shows a cross section of the saddle stitching processing section 8 on a plane parallel to the side surface of the saddle stitching processing section 8 and passing through the central portion in the width direction of the saddle stitching processing tray 80. In the drawing, the illustration of cross sections in hatching or the like is omitted.

  Here, the operation of the saddle stitching processing unit 8 when a process of folding a plurality of sheets after being stapled by the stapler 83, that is, when the binding process and the folding process are performed will be described. In this case, after the sheet is bound by the stapler 83 at the position indicated by the alternate long and short dash line A (binding position A) in the figure, the position indicated by the dashed line B (folding position B), that is, the position below the binding position A in the figure. At the folding knife 86 or the like. At this time, by changing the position of the stopper 81 after the sheets are bound, the folding process is performed after the sheets are displaced downward, and the binding position and the folding position are substantially the same.

  In this case, the stopper 81 is displaced in three stages as follows. That is, first, the stopper 81 is displaced upward from its home position (a reference position of the stopper 81 indicated by a solid line in the drawing). When the sheets stacked on the saddle stitching processing tray 80 are received one by one and when the binding process is performed, the stopper 81 is positioned at the stacking position (the position of the stopper 81a indicated by a broken line in the drawing). When the binding process is performed, the stopper 81 is displaced downward. When the folding process is performed, the stopper 81 is located at a discharge position below the stacking position (a position of the stopper 81b indicated by a broken line in the drawing). When the movement amount of the stopper 81 from the position at the home position is indicated by D, the movement amount D is larger when the stopper 81 is at the loading position than when the stopper 81 is at the discharge position.

  With the stopper 81 positioned at the stacking position, a plurality of sheets are sequentially conveyed to the saddle stitching processing tray 80 and stacked on the saddle stitching processing tray 80. The stacked sheets are stacked such that the portion to be bound is positioned at the binding position A (hereinafter, this may be expressed as “the sheet is positioned at the binding position A”). When the final paper stacking operation and alignment operation are completed, one side of the stacked paper is clamped by a paper clamping member (not shown) attached to the stopper 81. Thereafter, the stapler 83 is driven to perform saddle stitching to a predetermined position of the sheet.

  Note that the position of the stopper 81 when the sheets are stacked may be different from the position of the stopper 81 when the sheets are saddle-stitched. In this case, after the sheets are stacked, the stopper 81 holds the sheets and descends along the saddle stitching processing tray 80. The stopper 81 is moved so that the sheet is positioned at the binding position A.

  When the binding process is completed, the stopper 81 is lowered and the portion of the paper to be folded is located at the folding position B (hereinafter, this may be expressed as “the paper is located at the folding position B”). Is moved. The movement to the folding position is performed by controlling the lowering amount of the stopper 81 so that the approximate center in the length direction of the sheet coincides with the folding position B. In the present embodiment, the amount of movement from the saddle stitching position to the folding position is constant regardless of the size (size) of the paper. That is, the sheet is moved by the same dimension as the distance between the binding position A and the folding position B. After the movement of the stopper 81 is completed, the nipping of the paper is released.

  The folding process is performed as follows. That is, when the folding knife 86 is driven and displaced toward the paper, the central portion in the length direction of the paper is abutted against the nip portion of the folding roller 90. Further, when the folding roller 90 is driven, the sheet is creased. When the creased sheet is folded and pressed between the folding rollers 90 and conveyed by the folding roller 90, the sheet is folded into two approximately evenly at a substantially central position in the length direction. The paper folded into a booklet is ejected as indicated by an arrow V in the figure and stacked on the booklet tray 5.

  When the saddle stitching process is subsequently performed, the stopper 81 is moved upward along the saddle stitching processing tray 80 and returned to the stacking position. When the movement of the stopper 81 is completed, it becomes possible to start stacking the next set of plural sheets.

  The saddle stitching processing unit 8 may simply perform the folding process and discharge the sheet without performing the saddle stitching by the stapler 83. Further, in addition to the above-described paper processing, the saddle stitching processing unit 8 may perform perforation processing for each paper as paper processing.

  The saddle stitching processing unit 8 can fold a plurality of sheets into three by folding processing. In this case, first, one of the two portions of the paper to be bent is bent by the operation of the folding knife 86 and the folding roller 90. The paper folded by the folding knife 86 and the folding roller 90 is conveyed to the three-fold mechanism 93 and then sandwiched between the three-fold roller 94 and the folding roller 90. As a result, the remaining one of the folded portions is folded, and the sheet is discharged to the booklet tray 5 in a state of being folded in three through a path indicated by an arrow W in the drawing.

  [Control of the position of the stopper 81]

  In the present embodiment, the position of the stopper 81 in each sheet processing scene is the information regarding the sheet processing mode, the size (size) of the sheets stacked on the saddle stitching processing tray 80, and the flexibility (sheets). It is determined according to the information regarding the weakness of the waist and the number of sheets. The information relating to the form of paper processing refers to information indicating whether to perform saddle stitching (two-folding) or three-folding. The information regarding the size of the paper refers to information indicating whether the paper is A4 size, A3 size, B4 size, B5 size, or the like. The information on the number of sheets refers to information indicating how many sheets are stacked to form a set of sheets and to perform binding processing and folding processing, for example.

  Here, in the present embodiment, the information regarding the flexibility of the paper refers to information indicating the type of the paper. Examples of the paper type include plain paper, thick paper, thin paper, and an OHP (overhead projector) sheet. The flexibility of the paper differs depending on the type. Thin paper (for example, paper whose basis weight is less than 60 grams per square meter is called thin paper, but is not limited to this) has a flexible property, and other types of paper are flexible here. It does not have properties. That is, when the paper type is thin paper, it can be said that the paper has a property of being easily bent, and when the paper type is other than thin paper, it can be said that the paper does not have the property of being easily bent.

  For example, the control unit 10 may acquire the basis weight of the paper and the thickness of the paper as information regarding the flexibility of the paper. For example, when the basis weight or thickness is smaller than a predetermined threshold value, it may be determined that the sheet has a property of being easily bent.

  For example, what kind of paper has a property of being easily bent, and how much the basis weight or thickness is to have a property of a paper to be easily bent can be determined in advance by experiments, for example. In the present embodiment, when a sheet is placed in a state similar to the state in which the sheet is actually stacked on the saddle stitching processing tray 80, the sheet has a certain amount (for example, the leading and trailing ends of the sheet in the transport direction). When it is recognized that the distance is deflected (to the extent that the distance is shortened by a predetermined amount (for example, 2 millimeters) or more), it can be determined that the sheet is a flexible sheet. Note that the criteria for determining whether or not the sheet is flexible is not limited to this.

  The control unit 10, for example, specifies the number of sheets stacked on the saddle stitching processing tray 80 and the sheets according to the content of the sheet processing to be executed by the sheet processing apparatus 1 specified by the user via the operation unit 111. Information on the mode of processing is acquired.

  In addition, the control unit 10 acquires information on the size of the paper stacked on the saddle stitching processing tray 80 and information on the flexibility of the paper as follows, and controls the position of the stopper 81 accordingly. I do. That is, in the present embodiment, information relating to the size of a sheet set in the sheet cassette 113 of the image forming apparatus main body 110, that is, a sheet conveyed from the image forming apparatus main body 110 to the sheet processing apparatus 1 is stored in advance. Information relating to the flexibility (such as information indicating the type of paper) is set in the image forming apparatus 100. This information is input to the image forming apparatus main body 110 via the operation unit 111 by the user. Information set in advance regarding these sheets is stored in the control unit 120 of the image forming apparatus 100. The control unit 10 receives information from the control unit 120 of the image forming apparatus 100 and holds information including information regarding the size of the paper and information regarding the flexibility. The control unit 10 acquires information on the size and the flexibility of the paper from information preset by the user regarding the held paper. Note that the information regarding the size and the flexibility of the paper may be information automatically detected by a sensor provided in the paper cassette 113.

  Specifically, the control for changing the position of the stopper 81 is performed as follows.

  First, the loading position and discharge position of the stopper 81 are roughly determined according to the sheet processing mode and the sheet size. That is, when the sheet processing is folded in half, the position of the stopper 81 is controlled so that the binding position A and the folding position B are approximately the center in the longitudinal direction of the sheet. On the other hand, when the sheet processing is folded in three, the position of the stopper 81 is controlled so that the binding position A and the folding position B are, for example, positions that divide the sheet approximately 1: 2 in the longitudinal direction. Even when the same folding process is performed, for example, when the paper is A4 vertical size, the position of the stopper 81 is controlled to be lower than when the paper is B5 vertical size. . Thereby, it is possible to appropriately perform folding processing and the like on various sizes of paper.

  Here, the position of the stopper 81 when the sheets are stacked on the saddle stitching processing tray 80 (that is, the stacking position when the binding process is performed, and the discharge position when the binding process is not performed). Fine adjustment is made according to the flexibility of the paper and the number of papers. The control unit 10 determines whether the number of sheets stacked on the saddle stitching processing tray 80 at a time and subjected to sheet processing is less than a predetermined number (for example, five sheets) that is a threshold value or more than a predetermined number. The control content is changed according to. In the present embodiment, when the number of sheets is equal to or greater than a predetermined number, or the sheets do not have a tendency to bend, the stopper 81 is positioned at the normal position (first position) with respect to the stacking position and the discharge position. In addition, control is performed by the control unit 10. On the other hand, when the number of sheets is less than the predetermined number and the sheet has a tendency to bend, the control unit is configured so that the stopper 81 is positioned at the thin sheet position (second position) above the normal position. 10 is controlled.

  The thin paper position is a position that is set relative to the normal position in consideration of the occurrence of paper deflection. The thin paper position is a position where the position where the sheet processing is performed on the bent paper becomes an appropriate position when the paper is bent. When the paper processing stopper 81 is positioned at the stacking position, it is positioned at the normal position of the stacking position or the thin paper position of the stacking position above it according to the ease of deflection and the number of sheets. Further, when the stopper 81 is located at the paper discharge position, the stopper 81 is located at the normal position of the paper discharge position or at the thin paper position of the paper discharge position above it according to the flexibility and number of sheets.

  Note that the threshold value of the number of sheets stacked on the saddle stitching processing tray 80 may be determined by experiment, for example. That is, in the present embodiment, when a plurality of sheets (such as thin sheets) having a flexible property are placed in a state similar to the state in which a plurality of sheets are actually stacked on the saddle stitching processing tray 80 (for example, the sheet) It is observed whether or not the distance between the front end portion and the rear end portion in the transport direction is bent by a predetermined amount (for example, 2 mm) or more. A flexible sheet bends when its number is small. However, as the number of stacked sheets increases, the entire sheet bundle becomes stiff and the amount of deflection decreases. The threshold value of the number of sheets stacked on the saddle stitching processing tray 80 can be set according to the accumulated number of sheets, which is a boundary on whether or not the above-mentioned certain degree of deflection occurs. The threshold value for the number of sheets is not limited to that set in this way.

  Here, in the present embodiment, the normal position and the thin paper position are set in advance corresponding to the size and type of the sheets stacked on the saddle stitching processing tray 80. Information on the set normal position and thin paper position is stored in the ROM 13, for example. The control unit 10 can quickly determine the position where the stopper 81 should be displaced by referring to the information on the normal position and the thin paper position set in advance based on the information on the size and type of the paper.

  FIG. 6 is a table showing an example of a normal position and a thin paper position that are set in advance for the stacking position of the stopper 81.

  The figure shows an example of the stop position of the stopper 81 when the sheet size is A4 and the saddle stitching process is performed. The number of sheets stacked on the saddle stitching processing tray 80 is a predetermined number (for example, 5 sheets). ) It is shown for each paper type, whether it is above or not. Referring to the figure, here, as paper types, plain paper (paper with a basis weight of 60 to 90 grams per square meter), thick paper (paper with a basis weight of over 90 grams per square meter), and thin paper (with a basis weight of Suppose there are three types of paper (less than 60 grams per square meter). In the figure, the distance value is a value corresponding to the movement amount D of the stopper 81 from the home position shown in FIG.

  Referring to the figure, when the number of sheets stacked on the saddle stitching processing tray 80 at one time and subjected to sheet processing is less than a predetermined number, that is, 1 to 4, the sheet is plain paper or thick paper. The position of the stopper 81 is different between the case and the case where the paper is thin. When the paper is plain paper or thick paper, the value of the movement amount D is 67.4 millimeters. On the other hand, when the paper is thin paper, the value of the movement amount D is 68.9 millimeters. When the paper is thin paper, the movement amount D is larger than when the paper is plain paper or thick paper. That is, in this case, when the paper is thin, that is, when the paper has a property of being easily bent, the position of the stopper 81 is such that the stopper 81 is positioned higher than when the paper is of other types. Be controlled.

  Further, when the number of sheets that are stacked on the saddle stitching processing tray 80 at a time and are subjected to sheet processing is equal to or greater than a predetermined number, that is, five or more, the sheet is plain paper or thick paper and the sheet is thin paper. In this case, the position of the stopper 81 does not change. That is, in this case, the value of the movement amount D is 67.4 millimeters regardless of the type of paper.

  FIG. 7 is a flowchart illustrating an example of control for changing the position of the stopper 81 when the binding process and the folding process are performed.

  With reference to the drawings, a flow of control performed by the control unit 10 to change the position of the stopper 81 when paper processing is performed as an image is formed on the paper by the image forming apparatus 100 will be described. Here, the paper processing is assumed to be performed by binding processing and folding processing.

  When image formation is performed, in step S11, the control unit 10 confirms whether or not to execute paper processing. Whether or not to execute the sheet processing is determined based on, for example, the instruction content instructed by the user when the image forming apparatus 100 performs image formation. The control unit 10 can confirm whether or not to perform paper processing by communicating with the control unit 120 of the image forming apparatus main body 110. When the sheet processing is not executed, the sheet is conveyed through the processing unit 3 as it is and discharged to the sheet tray 4 or the like, so that the stopper 81 is not controlled.

  When paper processing is executed in step S11, in step S13, the control unit 10 checks whether or not the paper has a property of being easily bent.

  When the sheet is easily bent in step S13, in step S15, the control unit 10 checks whether or not the number of sheets stacked on the saddle stitching processing tray 80 at a time is equal to or greater than a predetermined number.

  If it is not more than the predetermined number in step S15, in step S17, the control unit 10 performs control to move the stopper 81 to the thin paper position. In this example, since the binding process is performed, the stopper 81 is moved to the thin paper position of the stacking position. Note that the stacking position is determined by the size of the paper and the manner of paper processing.

  On the other hand, when the number is greater than or equal to the predetermined number in step S15, or when the sheet does not have a property of being easily bent in step S13, in step S19, the control unit 10 performs control to move the stopper 81 to the normal position of the stacking position. In this example, since the binding process is performed, the stopper 81 is moved to the normal position of the stacking position.

  When the stopper 81 is moved to the stacking position in steps S17 and S19, in step S21, the control unit 10 starts stacking sheets. In other words, the control unit 10 moves the stopper 81 to the stacking position until the sheets are stacked on the saddle stitching processing tray 80. The sheets are sequentially stacked on the saddle stitching processing tray 80 one by one.

  In step S <b> 23, the control unit 10 confirms whether or not final sheets of a plurality of sheets to be stacked on the saddle stitching processing tray 80 are stacked. The control unit 10 stacks sheets on the saddle stitching processing tray 80 until the final sheet is stacked.

  When the last sheet is stacked in step S23, in step S25, the control unit 10 performs a binding process. That is, in the binding process, the stopper 81 is set to the thin paper position according to whether the paper is easily bent and whether the number of stacked sheets is equal to or more than a predetermined number at which the deflection is eliminated. It is executed after fine adjustment.

  When the binding process is finished in step S25, in step S27, the control unit 10 moves the stopper 81 by a predetermined amount and positions it at the discharge position. The amount of movement of the stopper 81 at this time is the distance between the binding position A and the folding position B. In the present embodiment, the amount of movement of the stopper 81 from the stacking position to the discharge position is constant regardless of how easily the sheet bends and the number of stacked sheets. That is, when the stopper 81 is at the thin paper position at the stacking position, the stopper 81 is moved to the thin paper position at the discharge position above the normal position at the discharge position. When the stopper 81 is at the normal position of the loading position, the stopper 81 is moved to the normal position of the discharge position.

  In step S29, the control unit 10 performs a folding process. As a result, the sheet is folded by the folding knife 86 and the folding roller 90 and discharged to the booklet tray 5. When the operation in step S29 ends, a series of operations ends.

  In addition, when the sheet processing is performed for a plurality of sets of sheets, the processes of steps S13 to S29 may be performed repeatedly. At this time, if the same paper is used and the paper processing is performed in the same manner, the control unit 10 omits the processes of steps S13 and S15 for the second and subsequent sets of paper and for the first set of paper. The same control as that performed may be performed.

  In the above description, the control when the folding process is performed after the binding process is performed, that is, when the stopper 81 is first displaced to the stacking position has been described, but the folding process is not performed by the stapler 83. Even when only the control is performed, the control is performed in the same manner as described above. That is, in this case, the processing from step S11 to S15 described above is performed, and in accordance with the result, the stopper 81 is moved to the normal position of the discharge position or the thin paper position above it in steps S17 and S19. The Thereafter, the processes of steps S21 and S23 are performed, and when the final sheet is stacked on the saddle stitching processing tray 80, the folding process of step S29 is executed.

  As described above, in the present embodiment, when the sheet is a thin sheet having a tendency to bend, the stopper 81 is moved to a thin sheet position above the normal position, and the sheet is stacked on the saddle stitching processing tray 80. Is done. Since the stopper 81 is arranged at a position in consideration of the occurrence of deflection as described above, the position where the binding process and the folding process are performed even when the sheet is bent is approximately the same as the case where the sheet is not bent. Become position. In other words, it is possible to prevent the sheet processing position from being shifted due to sheet deflection. Therefore, the sheet processing apparatus 1 can be used to perform the sheet processing to the target position, and the sheet processing with good appearance can be performed.

  Even if the paper is thin, when a predetermined number of sheets or more are stacked and paper processing is performed at once, the stopper 81 is disposed at the normal position. In other words, even when individual sheets are easily bent, if the sheet does not bend when a predetermined number of sheets are actually stacked, the sheet is arranged at a position corresponding to the sheet and sheet processing is performed. Therefore, the position at which the processing is performed is not shifted during the processing for a small number of thin papers and the processing for a large number of thin papers, and the binding processing and the folding processing are always performed at appropriate positions.

  In the present embodiment, one thin paper position is set relative to the normal position, and the stopper 81 is only positioned at one of the two positions of the normal position and the thin paper position. However, the thin paper position may be changed according to the degree of flexibility of the paper. That is, when the sheets stacked on the saddle stitching processing tray 80 have a tendency to bend, the control unit 10 controls to change the position of the thin sheet according to the degree of flexibility of the sheets of the same size. May be performed. The thin paper position may be changed in multiple stages, or may be a position appropriately calculated according to the degree of flexibility (for example, the basis weight or thickness of the paper). In this manner, by setting the position of the stopper 81 according to the flexibility of the paper such as the basis weight and type of the paper, the paper is placed at an appropriate position under the most suitable conditions for the paper according to the degree of the paper deflection. Processing can be performed.

  In the present embodiment, since the ease of bending of the paper is determined based on the paper information input by the user, it is possible to reliably determine whether the paper has a property of being easily bent. Therefore, the sheet processing position can be surely set to an appropriate position.

  [Explanation of Modified Example Regarding Timing of Displacement of Stopper 81]

  The timing for displacing the stopper 81 is not limited to that of the above-described embodiment, and the control of the position of the stopper 81 can be executed in various ways. The control unit 10 can control the position of the stopper 81 as follows when the sheets stacked on the saddle stitching processing tray 80 have a property of being easily bent. Each example below is an example in which only folding processing is performed.

  FIG. 8 is a flowchart showing a first modified example of the control for changing the position of the stopper 81 when the sheet has a property of being easily bent.

  In the above case, the control unit 10 moves the stopper 81 to the normal position when all sheets to be processed are stacked on the saddle stitching processing tray 80 in a state where the stopper 81 is in the thin paper position and the number of sheets exceeds a predetermined number. You may perform control to move to. In the example shown below, the stopper 81 is once moved to the thin paper position. After all sheets to be stacked are stacked on the saddle stitching processing tray 80, if there are more sheets than the predetermined number, the stopper 81 is moved to the normal position.

  In step S101, the control unit 10 moves the stopper 81 to the thin paper position.

  In step S <b> 103, the control unit 10 conveys one sheet and stacks it on the saddle stitching processing tray 80.

  In step S <b> 105, the control unit 10 confirms whether or not the conveyed sheet is the final sheet of a plurality of sheets to be stacked on the saddle stitching processing tray 80. If it is not the final sheet, the control unit 10 repeats the processes of steps S103 and S105. Thus, the sheets are conveyed one by one by the control unit 10 and stacked on the saddle stitching processing tray 80 until the final sheet is stacked.

  If it is the last sheet in step S105, in step S107, the control unit 10 checks whether or not the number of stacked sheets is 5 (an example of a predetermined number) or more.

  If the number of sheets stacked is 5 or more in step S107, the control unit 10 moves the stopper 81 from the thin paper position to the normal position (plain paper position) in step S109.

  When the process of step S109 is completed, or when the accumulated number of sheets is less than 5 in step S107, the control unit 10 ends the control relating to the position of the stopper 81 and executes the folding process.

  FIG. 9 is a flowchart showing a second modification of the control for changing the position of the stopper 81 in the case where the sheet is easily bent.

  In the above case, the control unit 10 may perform control to move the stopper 81 to the normal position from the time when a predetermined number of sheets or more are stacked on the saddle stitching processing tray 80 with the stopper 81 in the thin paper position. . In the example shown below, the stopper 81 is once moved to the thin paper position, and the stacking of paper is started. When the number of sheets stacked on the saddle stitching processing tray 80 exceeds a predetermined number, the stopper 81 is moved to the normal position, and the remaining sheets are stacked.

  In step S201, the control unit 10 moves the stopper 81 to the thin paper position.

  In step S <b> 203, the control unit 10 conveys one sheet and stacks it on the saddle stitching processing tray 80.

  In step S205, the control unit 10 confirms whether or not the number of stacked sheets has reached 5 (an example of a predetermined number).

  If there are five or more sheets in step S205, in step S207, the control unit 10 moves the stopper 81 from the thin paper position to the normal position (plain paper position).

  When the number of stacked sheets is not five or more in step S205, or when the process of step S207 is completed, in step S209, the control unit 10 determines that the conveyed sheets are to be stacked on the saddle stitching processing tray 80. Check whether it is the last sheet of paper. If it is not the final sheet, the control unit 10 repeats the processing from step S203 to step S207.

  If it is the last sheet in step S209, the control unit 10 ends the control relating to the position of the stopper 81 and executes the folding process.

  FIG. 10 is a flowchart showing a third modification of the control for changing the position of the stopper 81 in the case where the sheet is easily bent.

  In the above case, the control unit 10 may move the stopper 81 stepwise from a predetermined thin paper position to the normal position as the sheets are stacked. That is, the control unit 10 performs control to move the stopper 81 stepwise toward the normal position each time sheets are stacked one by one on the saddle stitching processing tray 80 with the stopper 81 in the thin paper position. . At this time, the control unit 10 moves the stopper 81 so that the stopper 81 is positioned at the normal position when the number of sheets stacked on the saddle stitching processing tray 80 reaches a predetermined number.

  In step S301, the control unit 10 moves the stopper 81 to the thin paper position.

  In step S <b> 303, the control unit 10 conveys one sheet and stacks it on the saddle stitching processing tray 80.

  In step S <b> 305, the control unit 10 confirms whether or not the conveyed sheet is a final sheet of a plurality of sheets to be stacked on the saddle stitching processing tray 80. If it is the final sheet, the control unit 10 causes the folding process to be performed while the stopper 81 is kept at the thin sheet position.

  If it is not the last sheet in step S305, in step S307, the control unit 10 checks whether or not the number of stacked sheets is 5 (an example of a predetermined number).

  If the number is not five or more in step S307, in step S309, the control unit 10 moves the stopper 81 from the thin paper position toward the normal position (plain paper position) by a predetermined movement amount. The movement amount at this time is an amount to be moved per sheet, for example, calculated as follows. That is, in this example, it is assumed that the thin paper position and the normal position are separated by, for example, 1.2 millimeters, and the predetermined number of sheets serving as the threshold is five. In this case, 0.3 mm obtained by dividing 1.2 mm by 4 sheets is the moving amount. In other words, the movement amount is set so that the stopper 81 is positioned at the normal position when the number of sheets stacked on the saddle stitching processing tray 80 reaches a predetermined number.

  When the number of sheets is five or more in step S307, or when the process of step S309 ends, the control unit 10 repeats the processes of step S303 to step S309 until the final sheet is stacked. When the last sheet is stacked, the control unit 10 ends the control related to the position of the stopper 81 and executes the folding process.

  In these modified examples, it is not necessary to control the number of stacked sheets before stacking the first sheet, and the control for finely adjusting the position of the stopper 81 can be relatively simplified. In these modified examples, the control unit 10 does not acquire information on the number of sheets stacked before stacking the first sheet, but detects the actual sheet conveyance status and stacking status, thereby detecting the number of stacked sheets. Even when acquiring information about In these modified examples, when sheet processing is performed for a plurality of sets of sheets, the processing shown in each figure may be repeated for each set.

  In particular, in the third modification, the position of the stopper 81 is changed step by step until a predetermined number of sheets are stacked until the final sheet is stacked. Therefore, when the number of stacked sheets is less than the predetermined number, the stopper 81 can be displaced from a predetermined thin paper position to the normal position according to the number of stacked sheets to perform sheet processing.

  [Explanation of Variations on Means for Obtaining Information on Flexibility of Paper]

  A deflection sensor (an example of a waist detection unit) that detects the presence / absence of deflection of the paper may be provided, and the control unit 10 may acquire information on the ease of deflection of the paper according to the detection result of the deflection sensor.

  The deflection sensor is disposed on the saddle stitching processing tray 80 as described below, for example, and detects whether or not the sheet is optically bent. In other words, the deflection sensor detects information about the weakness of the sheet, that is, the degree of flexibility, by detecting whether the sheet is bent or not. When the deflection sensor detects that the sheet is bent, it can be determined that the sheet is easily bent. The control unit 10 can acquire information related to the ease of deflection of the sheet according to the detection result of the deflection sensor.

  The deflection sensor may be configured as follows, for example.

  FIG. 11 is a side view of the saddle stitching processing unit 108 having a deflection sensor that detects the presence or absence of deflection of the paper.

  As shown in the drawing, the saddle stitching processing tray 80 is provided with deflection sensors 188a and 188b. The deflection sensors 188a and 188b are configured, for example, by combining a pair of a light transmission / reception unit 188a provided on the saddle stitching processing tray 80 and a reflection unit 188b provided on the stopper 81. That is, the light transmitting / receiving unit 188a emits, for example, a laser beam L toward the reflecting unit 188b. The reflection unit 188b reflects the laser beam L emitted from the light transmission / reception unit 188a toward the light transmission / reception unit 188a. The light transmitting / receiving unit 188a receives the laser beam L reflected by the reflecting unit 188b.

  The deflection sensors 188a and 188b are arranged so that the laser beam L is emitted / reflected along the saddle stitching processing tray 80 above the sheets stacked on the saddle stitching processing tray 80. Therefore, as shown in the figure, when the paper P1 stacked on the saddle stitching processing tray 80 is not bent, the laser beam L is reflected by the reflecting portion 188b and received by the light transmitting / receiving portion 188a. That is, the deflection sensors 188a and 188b detect that there is no paper deflection. At this time, the control unit 10 can determine that the sheet P1 is not bent, and can acquire information indicating that the sheet does not have a property of being easily bent.

  FIG. 12 is a diagram illustrating a case where sheets stacked in the saddle stitching processing unit 108 are bent.

  As shown in the drawing, when the sheet P2 stacked on the saddle stitching processing tray 80 is bent, the sheet P2 is positioned on a line connecting the reflection unit 188b and the light transmission / reception unit 188a. Therefore, in this case, the laser beam L is blocked by the paper P2, and is not received by the light transmitting / receiving unit 188a. That is, it is detected by the deflection sensors 188a and 188b that the sheet is bent. At this time, the control unit 10 can determine that the sheet P1 is not bent, and can acquire information indicating that the sheet is easily bent.

  Instead of the light transmitting / receiving unit 188a and the reflecting unit 188b, a deflection sensor may be configured by providing a pair of a light emitting unit that emits a laser beam and a light receiving unit that receives the light.

  FIG. 13 is a diagram illustrating a saddle stitching processing unit 208 in another modification of the sheet processing apparatus 1.

  A thickness sensor for measuring the thickness of the paper may be provided in the paper processing apparatus 1, and the control unit 10 may acquire information regarding the flexibility of the paper according to the detection result of the thickness sensor.

  As the thickness sensor, for example, an ultrasonic sensor can be used. The thickness sensor is provided on the paper transport paths 21, 31 to 33, the saddle stitching processing tray 80, and the like, and measures the thickness of the paper stacked on the saddle stitching processing tray 80. In the example shown in the figure, a thickness sensor 281 is disposed on the sheet conveyance path above the saddle stitching processing tray 80. The control unit 10 can acquire the thickness of the sheet measured by the thickness sensor as information indicating the ease of bending of the sheet. As the thickness sensor, for example, a sensor that detects the thickness according to transmitted light or a sensor that detects the thickness by being displaced according to the thickness of the paper may be used.

  Also, a basis weight sensor (an example of a basis weight detection unit) that detects information about the basis weight of the paper is provided in the paper processing apparatus 1, and information about the flexibility of the paper is displayed according to the detection result of the basis weight sensor. You may make it the control part 10 acquire.

  As the basis weight sensor, for example, a weight sensor can be used. In other words, in the example shown in the drawing, a weight sensor 288 as a basis weight sensor is disposed on the stopper 81 so that the weight of the sheets stacked on the saddle stitching processing tray 80 can be measured. The control unit 10 can calculate and acquire the basis weight based on the weight of one sheet measured by the weight sensor and information on the size (size, etc.) of the sheet loaded at that time. At this time, the control unit 10 may determine the paper type (thick paper, plain paper, thin paper, etc.) based on the calculated basis weight, and acquire the determination result as information on the flexibility of the paper.

  [Others]

  In the above embodiment, when the sheet has a property of being easily bent regardless of the number of sheets stacked on the saddle stitching processing tray, control for displacing the stopper to the thin sheet position may be performed. .

  Control of the position of the stopper and control accompanying it may be performed by the control unit of the image forming main body. Even in this case, it can be said that the control unit of the image forming apparatus as the sheet processing apparatus controls the position of the stopper.

  The sheet processing apparatus and the image forming apparatus main body may be housed in the same casing to constitute one image forming apparatus.

  In the sheet processing apparatus, the sheet conveyance path may be configured so that the sheet is conveyed to the stacking unit in a consistent conveyance direction without being switched back.

  A plurality of sheet cassettes may be provided, and each sheet feeding cassette may be capable of loading a plurality of types of sheets having different types (for example, types such as basis weight and paper quality) and sizes. In this case, the image forming apparatus forms an image on the paper loaded in the paper feeding cassette designated by the user or the paper loaded in the paper feeding cassette automatically designated by the control unit of the image forming apparatus main body. be able to. In this case, the user may input in advance the basis weight information of the paper loaded in each paper feed cassette to the image forming apparatus main body or the paper processing apparatus in association with each paper feed cassette. . In this case, the paper processing apparatus receives the information such as the basis weight of the paper to be processed from the control unit or the image forming apparatus main body so that the paper processing is appropriately performed. You may make it control the position of a stopper according to information. Information related to the paper feed cassette corresponding to the transported paper may be acquired.

  In addition to the above, the sheet processing apparatus may be able to execute a binding process (a process for collecting a plurality of sheets) or the like as a sheet process.

  The main body of the image forming apparatus may be a monochrome / color copying machine, a printer, a facsimile machine, or a complex machine (MFP) thereof. It is not limited to the one that forms an image by an electrophotographic method, and may be one that forms an image by a so-called inkjet method, for example.

  The processing in the above embodiment may be performed by software or by using a hardware circuit.

  A program for executing the processing in the above-described embodiment can be provided, or the program can be recorded on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, or a memory card and provided to the user. It may be. The program may be downloaded to the apparatus via a communication line such as the Internet. The processing described in the text in the above flowchart is executed by the CPU or the like according to the program.

  The above embodiment should 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 Paper processing apparatus 2 Horizontal conveyance part (an example of a conveyance part)
3 Processing unit body (an example of a transport unit)
8, 108, 208 Saddle stitching processing unit (an example of processing unit)
10 Control part (an example of a stopper control part, an example of a holding part)
80 Saddle stitching processing tray (an example of a stacking unit)
81 Stopper 83 Stapler 86 Folding knife 90 Folding roller 100 Image forming apparatus (an example of paper processing apparatus)
110 Image forming apparatus main body 120 Image forming apparatus main body control unit 188a, 188b Deflection sensor (an example of waist detection unit)
281 Thickness sensor (an example of a thickness detector)
288 Basis weight sensor (an example of basis weight detector)

Claims (14)

A transport unit for transporting paper;
A stacking unit on which the sheets conveyed by the conveying unit are stacked in an inclined state;
A stopper that is arranged to be displaceable along the stacking unit, and that positions a vertical position of the sheets stacked on the stacking unit;
A processing unit that performs paper processing on the paper that is positioned by the stopper and stacked on the stacking unit;
A first acquisition unit that acquires information about the size of the paper loaded on the stacking unit;
A second acquisition unit for acquiring information on the flexibility of the paper loaded on the stacking unit;
A stopper control unit that controls the position of the stopper when paper processing is performed by the processing unit according to the information acquired by the first acquisition unit and the information acquired by the second acquisition unit; A paper processing apparatus.   When the second acquisition unit acquires information related to the fact that the paper stacked on the stacking unit is easily bent, the stopper control unit receives the information about the same size paper. The sheet processing apparatus according to claim 1, wherein the control is performed so as to be positioned at a second position above the first position where the stopper is positioned when the stopper is not acquired.   3. The position according to claim 2, wherein each of the first position and the second position is a position set in advance corresponding to information on the size and flexibility of sheets stacked on the stacking unit. Paper processing equipment.   The stopper control unit is configured to determine whether or not the sheet having the same size is easily bent when the second acquisition unit acquires information on the fact that the sheet stacked on the stacking unit is easily bent. 4. The sheet processing apparatus according to claim 2, wherein control is performed to change the second position in accordance with the degree.   5. The sheet processing apparatus according to claim 2, wherein the stopper control unit performs the control according to the number of sheets stacked on the stacking unit.   The stopper control unit is configured such that when the second acquisition unit acquires information related to the fact that the sheets stacked on the stacking unit are easily bent, the number of sheets stacked on the stacking unit exceeds a predetermined number. The paper processing apparatus according to claim 5, wherein the control is performed such that the stopper is positioned at the first position.   The stopper control unit is configured to perform sheet processing in a state where the stopper is in the second position when the second acquisition unit acquires information regarding that the paper stacked on the stacking unit has a property of being easily bent. The control for moving the stopper to the first position is started when all the sheets to be printed are stacked on the stacking section and the number of sheets stacked on the stacking section is equal to or more than a predetermined number. 6. The paper processing apparatus according to 6.   The stopper control unit is configured such that when the second acquisition unit acquires information regarding that the sheets stacked on the stacking unit are easily bent, the stacking unit is in the state where the stopper is in the second position. 7. The sheet processing apparatus according to claim 5, wherein control is performed to move the stopper to the first position from a point in time when a predetermined number of sheets or more are stacked on the section. The stopper control unit is configured such that when the second acquisition unit acquires information on the fact that the paper stacked on the stacking unit is easily bent, the stopper is in the second position. Each time the sheet is loaded one by one on the loading unit, the stopper is moved stepwise toward the first position,
6. The stepwise movement control is performed so that the stopper is positioned at the first position and the movement is completed when a predetermined number of sheets are stacked on the stacking unit. Or the paper processing apparatus of 6.   The paper processing apparatus according to claim 1, wherein the information related to the flexibility of the paper loaded on the stacking unit is information related to at least one of a paper basis weight and a paper type. A holding unit that holds information preset by the user regarding the paper, a basis weight detection unit that detects information about the basis weight of the paper, a thickness detection unit that detects information about the paper thickness, and the strength of the paper And further comprising at least one of a waist detecting unit for detecting information,
The second acquisition unit acquires information on the flexibility of the paper loaded on the stacking unit from at least one of the holding unit, the basis weight detection unit, the thickness detection unit, and the waist detection unit. The sheet processing apparatus according to claim 1. An image forming apparatus main body;
A sheet processing apparatus according to any one of claims 1 to 11,
The sheet processing apparatus is an image forming apparatus that performs sheet processing on a sheet sent from the image forming apparatus main body and discharges the sheet. A transport unit for transporting paper;
A stacking unit on which the sheets conveyed by the conveying unit are stacked in an inclined state;
A stopper that is arranged to be displaceable along the stacking unit, and that positions a vertical position of the sheets stacked on the stacking unit;
A control method of a paper processing apparatus comprising: a processing unit that performs paper processing on the paper positioned by the stopper and stacked on the stacking unit;
A first acquisition step of acquiring information relating to the size of the paper loaded on the stacking unit;
A second acquisition step of acquiring information relating to the flexibility of the paper loaded on the stacking unit;
A stopper control step for controlling the position of the stopper when paper processing is performed by the processing unit according to the information acquired in the first acquisition step and the information acquired in the second acquisition step; A control method for a sheet processing apparatus. A transport unit for transporting paper;
A stacking unit on which the sheets conveyed by the conveying unit are stacked in an inclined state;
A stopper that is arranged to be displaceable along the stacking unit, and that positions a vertical position of the sheets stacked on the stacking unit;
A control program for a paper processing apparatus, comprising: a processing unit that performs paper processing on the paper that is positioned by the stopper and stacked on the stacking unit;
A first acquisition step of acquiring information relating to the size of the paper loaded on the stacking unit;
A second acquisition step of acquiring information relating to the flexibility of the paper loaded on the stacking unit;
A stopper control step for controlling the position of the stopper when paper processing is performed by the processing unit according to the information acquired in the first acquisition step and the information acquired in the second acquisition step; A method for controlling a paper processing apparatus that causes a computer to execute the above.

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