JP2012254869A - Sheet processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the takeout of a sheet from a sheet tray.SOLUTION: A control part determines a prescribed number on the basis of the number of sheets of a sheet bundle, an attribute of the sheet, a fold mode that refers to the state of the folding, a print mode referring to the state of printing, and a temperature and humidity in the circumstance where a sheet processor is installed (S5). A sheet tray includes a conveying belt for conveying the sheet bundle. The control part stacks the prescribed number of the sheet bundles, discharges them to the sheet tray (S9) in a state that the conveying belt is stopped, and then moves the conveying belt by a prescribed distance (S13).

Description

  The present invention relates to a sheet processing apparatus that receives a recorded sheet discharged from an image forming apparatus and performs post-processing.

  2. Description of the Related Art In recent years, sheet processing apparatuses that receive recorded paper (sheets) discharged from an image forming apparatus such as a printer or a copying machine and perform predetermined post-processing on a bundle of sheets have been widely used.

  Specifically, the sheet processing apparatus is provided with post-processing means such as staple (staple) binding, punching (round hole punching), and paper folding for the sheet bundle with respect to the paper after image formation.

  Among them, many proposals have been made for a sheet processing apparatus in which a recorded sheet (sheet) discharged from an image forming apparatus is bound and taken out. For example, the sheets discharged and stacked from the image forming apparatus are bound at the center, the sheets are saddle-stitched at the binding position, folded into two, and the book is placed on the sheet tray and taken out. A sheet processing apparatus has been proposed.

  For example, Japanese Patent Application Laid-Open No. 2004-284762 discloses a technique in which a large number of sheets are stacked and aligned on a sheet tray on which sheets discharged from an image forming apparatus are stacked.

JP 2004-284762 A

  In the above-mentioned patent document, the belt of the sheet tray is conveyed so that the overlapping amount of the bundles to be discharged is constant. Therefore, even when the number of sheets in the bundle is small, the belt is moved one bundle at a time. Therefore, when the number of sheets in the bundle is small, the conveying belt is immediately filled with the bundle. In addition, since the user has to collect thin bundles in order to take out the sheet bundle, it is difficult to take out the bundle from the sheet tray. Furthermore, if the number of times the conveyor belt moves is large, noise is generated and the amount of power consumption increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a sheet processing apparatus that facilitates the removal of a sheet from a sheet tray.

  A sheet processing apparatus according to an aspect of the present invention is a sheet processing apparatus that processes a sheet after an image is formed by printing of the image forming apparatus, and is configured to fold one or more sheets after the image is formed. A sheet folding unit that generates a bundle, a sheet tray that is stacked to take out the sheet bundle folded by the sheet folding unit, and a control unit that controls the sheet tray are provided.

  The sheet tray includes a conveyance belt that conveys the sheet bundle, and the control unit stacks a predetermined number of sheet bundles and discharges them to the sheet tray with the conveyance belt stopped, and then moves the conveyance belt by a predetermined distance. In addition, the control unit determines the predetermined number based on the number of sheets in the sheet bundle, the sheet attribute, the folding mode indicating the folding mode, the printing mode indicating the printing mode, and the temperature and humidity in the environment where the sheet processing apparatus is installed. Determine the number of copies.

  Preferably, the control unit moves the conveyor belt by a predetermined distance when a predetermined instruction is input in a process in which the sheet bundle is overlapped and discharged to the sheet tray in a state where the conveyor belt is stopped.

Preferably, the predetermined instruction indicates a print job switching instruction by the image forming apparatus.
Preferably, the control unit determines a speed at which a predetermined number of stacked sheet bundles are conveyed by the movement of the conveyance belt based on the number of sheets, sheet attributes, folding mode, printing mode, temperature, and humidity.

  Preferably, the control unit determines the predetermined distance based on the number of sheets, sheet attributes, folding mode, printing mode, temperature, and humidity.

  Preferably, the control unit determines the predetermined distance based on the number of sheets, sheet attributes, folding mode, printing mode, temperature, humidity, continuous printing time by the image forming apparatus, and image density.

  Preferably, the control unit determines the predetermined number of copies based on the number of sheets, sheet attributes, folding mode, printing mode, temperature, humidity, continuous printing time by the image forming apparatus, and image density.

  The control unit of the sheet processing apparatus according to the present invention stacks a predetermined number of sheet bundles and discharges them to the sheet tray in a state where the conveyance belt is stopped, and then moves the conveyance belt by a predetermined distance. The predetermined number of copies is determined based on the number of sheets in the sheet bundle, the sheet attributes, the folding mode indicating the folding mode, the printing mode indicating the printing mode, and the temperature and humidity in the environment where the sheet processing apparatus is installed. This facilitates removal of the sheet from the sheet tray.

1 is a schematic cross-sectional view of an image forming system including a post-processing apparatus (sheet processing apparatus) FS and an image forming apparatus A according to an embodiment of the present invention. It is a principal part expanded sectional view of the saddle 100 of the post-processing apparatus FS according to embodiment of this invention. It is a figure explaining the middle folding (bi-folding) process according to embodiment of this invention. It is a figure explaining the trifold process according to embodiment of this invention. It is a perspective view of sheet tray 800 according to an embodiment of the present invention. It is a schematic diagram of a sheet tray 800 according to an embodiment of the present invention. 1 is a schematic block diagram of an image forming apparatus A according to an embodiment of the present invention. It is a schematic block diagram of post-processing apparatus FS according to an embodiment of the present invention. It is a general-view figure of the operation panel 13 according to embodiment of this invention. It is a flowchart of the sheet alignment conveyance mode according to the embodiment of the present invention. It is a figure explaining the state which the sheet | seat according to embodiment of this invention accumulates. It is a figure explaining the other state in which the sheet | seat according to embodiment of this invention accumulates. It is a flowchart of the sheet bundle discharge conveyance mode according to the embodiment of the present invention. It is a block diagram of table TB1 according to an embodiment of the present invention. It is a process flowchart of the conveyance belt drive according to embodiment of this invention. It is another process flowchart of the conveyance belt drive according to embodiment of this invention. It is a block diagram of table TB2 according to an embodiment of the present invention. It is a processing flowchart of the conveyance speed determination according to the modification of embodiment of this invention. It is a process flowchart of additional conveyance distance determination according to the modification of embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

(Image forming system)
FIG. 1 is a schematic sectional view of an image forming system including a post-processing apparatus (sheet processing apparatus) FS and an image forming apparatus A according to an embodiment of the present invention.

(Image forming apparatus A)
The image forming apparatus A includes an image reading unit 1, an image processing unit 2, an image writing unit 3, an image forming unit 4, a paper feed cassette 5, a paper feed roller 6, a fixing device 7, and paper discharge. A roller 8 and an automatic double-sided copy paper feeding unit 9 are provided. An image is printed on the surface of the sheet S, which is a recording sheet, by the cooperative operation of these units.

  The fixing device 7 includes a heating roller 41, a pressure roller 42, and an electromagnetic induction coil (not shown) for heating the heating roller 41. When the heating roller 41 and the pressure roller 42 are pressed against each other, a fixing nip through which the sheet S passes is formed.

  An automatic document feeder 10 is mounted on the upper part of the image forming apparatus A. Further, a post-processing device FS is connected to the left side of the image forming apparatus A in the drawing on the paper discharge roller 8 side. The document placed on the document table of the automatic document feeder 10 is transported along the transport path, and an image on one or both sides of the document is scanned by the optical system of the image reading unit 1 to obtain a CCD (Charge Coupled Device) image. It is read by the sensor 1A.

  The analog signal photoelectrically converted by the CCD image sensor 1A is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit 2, and then sent to the image writing unit 3. The semiconductor laser is driven to emit light based on the image data sent to the image writing unit 3 and irradiated onto the photosensitive drum 4A of the image forming unit 4 to form a latent image. In the image forming unit 4, processes such as charging, exposure, development, transfer, separation, and cleaning are performed, and a toner image is formed on the photosensitive drum 4A.

  The sheet S fed from the sheet feeding cassette 5 by the sheet feeding roller 6 reaches the photosensitive drum 4A, and the toner image is transferred to the sheet S by the transfer unit 4B. The sheet S carrying the toner image is fixed by the fixing device 7 and sent from the paper discharge roller 8 to the post-processing device FS. In the case of double-sided copying, the sheet S that has undergone single-sided image processing is sent to the automatic double-sided copy paper feeding unit 9 by the conveyance path switching plate 8A, and after the toner image is transferred and fixed on the back side in the image forming unit 4, It is sent from the paper discharge roller 8 to the post-processing device FS.

(Post-processing device FS)
The post-processing device FS includes a paper carry-in unit 20 and a plurality of post-processing units. The post-processing unit includes a punching processing unit 40, a folding unit 50, an end binding (flat binding) processing unit 71, a saddle stitching processing unit 72, and a paper discharge unit 80.

  The sheet S after image formation sent from the paper discharge roller 8 of the image forming apparatus A to the post-processing apparatus FS is conveyed by the paper carry-in unit 20 into the post-processing apparatus FS.

  The punching processing unit 40 is disposed on the left-hand downstream side of the paper carry-in unit 20 and punches holes in the sheet S. Specifically, an entrance sensor 28 is provided in the vicinity of the entrance of the post-processing device FS, and when the sheet S is loaded into the post-processing device FS, the entrance sensor 28 detects the loading of the sheet S. Then, the conveyance of the sheet S is stopped after a predetermined time after the carry-in of the sheet S is detected, and the punching processing unit 40 opens a punch hole in the sheet S (punch processing).

  The conveyance path is branched into two conveyance paths H0 and H1 from the downstream of the punching processing unit 40. The conveyance paths H0 and H1 are switched by the conveyance path switching member 30. The conveyance path H <b> 1 branched downward is connected to a saddle (may be abbreviated as SD in the drawing) 100 via a conveyance roller 23. As will be described later, the saddle 100 includes a saddle stitching processing unit 72 and a folding unit 50, which will be described in detail later.

The other transport path H 0 is connected to the paper discharge unit 80 via the transport roller 24.
In the post-processing device FS, when a large amount of image formation is performed without processing by the post-processing unit, the sheet S passes from the paper carry-in unit 20 through the conveyance path H0 to the discharge paddle 22 of the paper discharge unit 80, and the post-processing device FS. It is discharged to an elevator tray 81 provided at the outlet.

  The elevator tray 81 moves downward as indicated by a chain line in the drawing so that the uppermost surface of the discharged sheet S is always at a constant height. Therefore, thousands of sheets can be stacked on the elevator tray 81. In addition, a paper detection sensor 26 is provided in the conveyance path H0, detects the passage of the sheet S in the conveyance path H0, and executes drive timing control for the conveyance roller 24, the discharge paddle 22, and the like.

  Further, the discharge paddle 22 is configured to be movable between a pressed state and a separated state. When the discharge paddle 22 is in pressure contact, the sheet S is discharged to the elevator tray 81 as described above. On the other hand, when the discharge paddle 22 is separated, the sheet is not immediately discharged to the elevator tray 81, and after the sheet S reaches the discharge paddle 22, the trailing end of the sheet S falls on the accommodation belt 70. The accommodation belt 70 and the accommodation paddle 74 rotate to convey the sheet in the direction in which the end binding processing unit 71 is provided. Then, the processing is executed a plurality of times for the plurality of sheets S, the processing tray sensor 77 detects that a predetermined number of sheets is stored in the end binding processing unit 71, and the end binding processing is executed. Thereafter, the accommodation belt 70 and the accommodation paddle 74 convey the sheet bundle bound in the direction of the discharge paddle 22, and the sheet bundle is discharged from the discharge paddle 22 to the elevator tray 81.

  The saddle 100 is disposed obliquely with respect to the horizontal direction downstream of the conveying roller 23, and includes a plurality of guide members and leading end stoppers for guiding the sheet S, a saddle stitching processing unit 72, a folding unit 50, and sheet width alignment. The sheet is processed in each of the half-fold (two-fold) mode, the half-fold / saddle-binding mode, and the three-fold mode for one or more sheets S, and discharged to the sheet tray 800. In this example, the saddle 100 is subjected to a two-fold or three-fold process on one sheet S or a bundle of a plurality of sheets S, and then is discharged to the sheet tray 800. Therefore, a sheet S or a bundle of a plurality of sheets S discharged in this way is simply referred to as “bundle” or “sheet bundle”, and the number of sheets S constituting the sheet bundle is referred to as “bundle number”. ".

  FIG. 2 is an enlarged cross-sectional view of a main part of saddle 100 of post-processing device FS according to the embodiment of the present invention.

With reference to FIG. 2, the sheet S is carried in from obliquely upward to obliquely downward. Also, as described in the lower right in the figure, in the following description, the direction going diagonally downward is the X direction, the direction orthogonal to the X direction on the paper is the Y direction, and the direction perpendicular to the paper is the Z direction.

  The guide members constituting the saddle 100 are composed of upstream guide members 101 and 102 and downstream guide members 103 and 104. The sheet width aligning portion 110 is located on the upper side of the upstream guide members 101 and 102, and the upstream side. The saddle stitching processing section 72 is positioned in the middle of the guide members 101 and 102, and the folding section 50 is positioned between the upstream guide members 101 and 102 and the downstream guide members 103 and 104.

  The sheets S carried into the saddle 100 via the conveyance path H1 are detected one by one by the saddle carry-in sensor 62. And the sheet | seat S carried in is conveyed along a guide member with dead weight. At that time, the upper paddle 75 and the lower paddle 76 rotate in contact with the surface of the sheet, whereby the sheets are smoothly conveyed one by one.

The sheet width aligning unit 110 performs alignment in the width direction (Z, reverse Z direction) of the sheet S.
A distal end stopper 105 that is movable along the downstream guide members 103 and 104 is provided downstream of the folding unit 50. The leading end stopper 105 restricts the lower end of the sheet S to a predetermined position, and is moved according to the paper size.

  The upstream guide member 101 and the downstream guide member 103 are located on the lower side (reverse Y direction side) of the saddle 100, and constitute a stack surface on which the sheets S slide down along the surface. Further, the upstream guide member 102 and the downstream guide member 104 are disposed to face the upstream guide member 101 and the downstream guide member 103 at a predetermined interval.

  The saddle stitching processing unit 72 includes a needle receiving mechanism 72a and a needle striking mechanism 72b. The saddle stitching processing unit 72 operates when the central portion in the sheet transport direction of the bundle of sheets S is positioned by the leading end stopper 105, and the bundle of sheets S is saddle stitched. To do. Specifically, the leading end stopper 105 moves in the sheet conveyance direction (X, reverse X direction) of the sheet S, so that the central portion of the plurality of sheets S is aligned with the saddle stitching processing unit 72 and stacked. After a plurality of sheets S are stacked, the bundle of sheets S is saddle-stitched by the saddle stitching processing unit 72. When the saddle stitching processing unit 72 does not perform the saddle stitching process, the sheets S are stacked so that the center portion of the sheet S fits the folding unit 50.

  The folding unit 50 includes a first folding plate 51, a first folding roller 52, a second folding roller 53, a third folding roller 54, a fourth folding roller 56, a fifth folding roller 58, a transport path switching member 55, and a guide member 57. The first folded plate sensor 59, the second folded plate 60, and the second folded plate sensor 61 are provided, and the sheet S is subjected to middle folding (folding) processing or three folding processing.

FIG. 3 is a diagram for explaining a half-folding process in accordance with the embodiment of the present invention.
With reference to FIGS. 2 and 3, in the half-folding process, first, the leading end stopper 105 is moved so that the center portion of the length of the sheet S becomes the position of the first folding plate 51. Next, as shown in FIG. 3A, the first and second folding rollers 52 and 53 rotate, and the first folding plate 51 causes the sheet S to pass between the first folding roller 52 and the second folding roller 53. Insert into. Since the first folding roller 52 and the second folding roller 53 are urged to come into pressure contact with each other by a spring member (not shown), the sheet S is folded at the center in FIG. 3B. Then, the sheet S folded by the guide member 57 provided below the transport path switching member 55 is transported to the fourth and fifth folding rollers 56 and 58. As shown in FIG. 3C, the fourth and fifth folding rollers 56 and 58 rotate to convey the folded sheet S. In FIG. 3D, the fourth and fifth folding rollers 56 and 58 discharge the folded sheet S to the sheet tray 800. The first folded plate sensor 59 detects the home position of the first folded plate 51, and the moved first folded plate 51 is returned to the home position.

FIG. 4 is a diagram illustrating tri-fold processing according to the embodiment of the present invention.
2 and 4, first, in the tri-fold process, the transport path switching member 55 moves and is set to the position indicated by the dotted line in FIG. The sheet S is moved by the leading end stopper 105 so that the position of one third of the length of the sheet S becomes the position of the folding plate 51. Next, as shown in FIG. 4A, the first and second folding rollers 52 and 53 rotate, and the first folding plate 51 causes the sheet S to pass between the first folding roller 52 and the second folding roller 53. Insert into. In FIG. 4B, the sheet S is folded and creased at one third of its length. Next, in FIG. 4C, the sheet S is guided upward along the shape of the transport path switching member 55 with the fold as the head. The sheet S guided along the shape of the conveyance path switching member 55 is stopped by a stop member (not shown). The stop member is used for positioning the sheet S when the second folding plate 60 performs the folding process, and a position where the second folding plate 60 makes a crease at the center of the length of the sheet S subjected to the folding process. Adjust so that

  Next, in FIG. 4D, while the second folding roller 53 and the third folding roller 54 rotate, the second folding plate 60 puts the sheet S between the second folding roller 53 and the third folding roller 54. insert. It is assumed that the second folding roller 53 and the third folding roller 54 are urged so as to be pressed against each other by a spring member (not shown). The folded sheet S is further folded and folded by the second folding plate 60 at the center of the remaining length. In FIG. 4E, the second and third folding rollers 53 and 54 rotate and discharge the folded sheet S to the sheet tray 800. The first folded plate sensor 59 detects the home position of the first folded plate 51, and the moved first folded plate 51 is returned to the home position. The second folded plate sensor 61 detects the home position of the second folded plate 60, and the moved second folded plate 60 is returned to the home position. As for the tri-folding process, the sheet S is first folded at a position that is one third of the length, and the half of the remaining length is creased so that the folded side is folded. A folding process is performed.

  Here, the two-fold or three-fold processing of one sheet S has been described, but the processing is not limited to one, and the same processing can be performed for a bundle of sheets S composed of a plurality of sheets.

FIG. 5 is a perspective view of sheet tray 800 according to the embodiment of the present invention.
Referring to FIG. 5, the sheet tray 800 includes a placement member 820 and a stopper member 822.

  The stopper member 822 is connected to the mounting member 820 at the end, and can be folded so as to overlap the mounting member 820, and can be housed on the side surface of the post-processing device FS together with the mounting member 820. It is.

  Further, the stopper member 822 is provided with a gripping portion 826, and the angle of the sheet tray 800 can be adjusted by holding the gripping portion 826, which will be described later.

  The mounting member 820 is provided with two conveying belts 827A and 827B. The sheet S or the sheet bundle placed on the sheet tray 800 is transported via the transport belts 827A and 827B.

  In addition, the mounting member 820 is provided with movable members 823 and 824. Here, the movable member 824 is not shown. When the sheet S or the sheet bundle placed on the sheet tray 800 is transported via the transport belt, it contacts the movable members 823 and 824, and the movable members 823 and 824 move downward.

  Further, the placement member 820 is provided with a transport button 825. When the transport button 825 is pressed, the transport belts 827A and 827B can be driven.

FIG. 6 is a schematic diagram of a sheet tray 800 according to the embodiment of the present invention.
FIG. 6A is a view of the sheet tray 800 as viewed from above. FIG. 6B is a cross-sectional view of the sheet tray 800.

  Two conveying belts 827A and 827B, which are conveying units for conveying the sheet S or the sheet bundle, are installed on the placing member 820 of the sheet tray 800, and the conveying belts 827A and 827B are rotated by the rotation of the belt conveying rollers 821A and 821B. Is rotated in the direction of arrow c shown in FIG. 5A and in the direction of arrow d shown in FIG.

  As shown in FIG. 6A, a movable member 823 that is moved by the sheet S or a sheet bundle is installed in the vicinity of the stopper member 822 and in the vicinity of the approximate center between the two conveying belts 827A and 827B. Yes.

  Further, a movable member 824 that is moved by the sheet S or the sheet bundle is installed near the entrance opposite to the stopper member 822 and in the vicinity of the approximate center between the two transport belts 827A and 827B.

  The sheet S or the sheet bundle discharged to the placing member 820 of the sheet tray 800 is stacked as illustrated (the stacked state of the sheets S in FIG. 6B is schematically illustrated). It is gradually conveyed by 827A and 827B.

  As illustrated, the movable member 823 is moved to a hidden position inside the placement member 820 by the contact of the leading sheet S or the sheet bundle. In the placement member 820, a detection member (sheet tray tip sensor) that detects that the movable member 823 has moved to a position inside the placement member 820 is disposed. By the movement of the movable member 823, the detection member can grasp that the sheet S or the sheet bundle has reached the position.

  The movable member 824 is provided at a position where the sheet S is discharged so as to cover the movable member 824 when the sheet S or the sheet bundle is discharged from the folding unit 50 to the sheet tray 800. . Therefore, when the sheet S is discharged, the movable member 824 is moved to a hidden position inside the placement member 820 in the same manner as the movable member 823. A detection member (sheet tray inlet sensor) that detects that the movable member 824 has moved to a position inside the placement member 820 is disposed in the placement member 820. By the movement of the movable member 824, the detection member can detect that the folded sheet is discharged to the position, that is, the sheet tray 800.

FIG. 7 is a schematic block diagram of image forming apparatus A according to the embodiment of the present invention.
Referring to FIG. 7, an image forming apparatus A includes a main control unit 150 that controls the entire apparatus, an image reading unit 1, an image processing unit 2, an image writing unit 3, an image forming unit 4, and an automatic unit. A document feeder (ADF (Auto Document Feeder)) 10, an operation panel 13, an audio output unit 14, an external device interface 15, and a communication interface 16 are provided.

  The main control unit 150 includes a CPU (Central Processing Unit) 151 for executing various programs including an operating system (OS), and a ROM (Read Only Memory) 152 in which programs executed by the CPU 151 are stored in advance. And a RAM (Random Access Memory) 153 that temporarily stores data necessary for executing the program portion of the CPU 151.

  The main control unit 150 reads the image from the document loaded on the ADF 10 using the image reading unit 1 and converts it into electronic data, and performs various image processing on the read image using the image processing unit 2. Image processing control to be performed, image formation control for forming an image processed image on a sheet by a known electrophotographic process using the image writing unit 3 and the image forming unit 4, and conveying the sheet S on which the image is formed The sheet feeding control is executed.

  The operation panel 13 has a touch panel, can set the type of post-processing to be applied to the sheet S, perform operation settings for various other functions, and can confirm the set functions and display various warnings. It is configured. As will be described later, for example, a numeric keypad for setting the number of copies, a start key for instructing operation start, a stop key for instructing operation stop, a reset key for initializing various setting conditions, and the like are displayed on the operation panel 13. The

  From the operation panel 13 to the main control unit 150, based on the user's operation, information on paper media indicating attributes (features) unique to the paper such as the size of the sheet S, and post-processing type information (whether folding / binding is performed) Job including a folding mode, a printing mode and their types, and the number of sheet bundles).

  The main control unit 150 transmits these jobs to the post-processing device FS through the communication interface 16.

  The sound output unit 14 outputs an error sound when an error such as an operation sound, a warning sound, or a paper jam occurs. An external network 17 is connected to the external device interface 15. Thereby, it is comprised so that communication with the other apparatus on a network is possible.

  In addition to the copying function, the image forming apparatus A has a scanning function for acquiring image data, and a printing function for receiving and printing image data from a device such as an external personal computer (not shown). A FAX function capable of facsimile transmission is provided.

FIG. 8 is a schematic block diagram of post-processing device FS according to the embodiment of the present invention.
Referring to FIG. 8, post-processing device FS includes a finisher control unit 200 that controls the entire post-processing device FS, and a communication interface 87 for communicating information with image forming apparatus A.

  The finisher control unit 200 temporarily stores a CPU 201 for executing various programs including an operating system, a ROM 202 in which a program executed by the CPU 201 is stored in advance, and data necessary for executing a program portion of the CPU 201. RAM 203 is provided. In the ROM 202, tables TB1 and TB2 described later are stored in advance.

  The finisher control unit 200 controls each unit in the post-processing device FS based on the job output from the image forming apparatus A.

  The finisher control unit 200 is connected to various sensors. Specifically, the paper detection sensors 26 and 73, the saddle carry-in sensor 62, the inlet sensor 28, the sheet tray inlet sensor 38, the sheet tray leading edge sensor 39, the first folding plate sensor 59, and the second folding plate. The sensor 61, the sheet tray upper sensor 82, and the sheet tray lower sensor 84 are connected to the finisher control unit 200. Further, a temperature sensor 111 and a humidity sensor 112 for measuring the temperature and humidity of the surrounding environment where the image forming system of FIG. 1 is installed are connected to the finisher control unit 200. The finisher control unit 200 inputs detection signals from various sensors.

  The finisher control unit 200 controls the changeover switches 86 and 88. The changeover switches 86 and 88 are connected to the conveyance path switching members 30 and 55, respectively. By switching the changeover switches 86 and 88, the positions of the transport path switching members 30 and 55 are changed to switch the transport path.

The finisher control unit 200 controls various motors.
Tip stopper 105, upper paddle 75, lower paddle 76, transport rollers 23 and 24, first folding plate 51, folding rollers 52 to 54, 56, and 58, discharge paddle 22, transport belts 827A and 827B, elevator tray 81, first tray The two folded plates 60 are respectively a front end stopper motor 90, an upper paddle motor 91, a lower paddle motor 92, a transport motor 93, a first folded plate motor 94, a folding roller motor 95, a discharge paddle motor 96, a transport belt motor 97, and an elevator. The motor 98 and the second folded plate motor 99 are respectively driven.

  Here, the CPU 201 outputs a level instruction (voltage signal) according to the conveyance speed to the conveyance belt motor 97. The period during which the voltage signal is output follows the transport distance. The rotation shaft of the conveyance belt motor 97 is connected to the rotation shafts of the belt conveyance rollers 821A and 821B.

  In operation, the conveyor belt motor 97 rotates in the direction (forward / reverse rotation) and amount according to the voltage signal from the CPU 201. The belt conveyance rollers 821A and 821B rotate in conjunction with the rotation of the conveyance belt motor 97. As the belt conveying rollers 821A and 821B rotate, the conveying belts 827A and 827B move, and the sheet S on the sheet tray 800 is conveyed. Further, the conveyance belt motor 97 is stopped by stopping the output of the voltage signal (that is, the belt conveyance rollers 821A and 821B are stopped), and the movement of the conveyance belts 827A and 827B is also stopped in conjunction with this. As a result, the conveyance of the sheet S on the sheet tray 800 is also stopped.

  The finisher control unit 200 controls the punching processing unit 40, the edge binding processing unit 71, the saddle stitching processing unit 72, the paper width matching unit 110, and the like.

  Here, in order to simplify the explanation, illustration of motors for driving the accommodation belt 70 and the accommodation paddle 74 is omitted. The same applies to other parts.

FIG. 9 is an overview diagram of operation panel 13 according to the embodiment of the present invention.
Referring to FIG. 9, operation panel 13 according to the embodiment of the present invention includes a display unit 312, a numeric keypad 302, and a start button 310. Other keys are omitted.

  A touch panel is provided on the display unit 312, and a predetermined operation can be performed on the display unit 312. A numeric keypad 302 is a button for inputting the number of copies. The start button 310 is a button for instructing execution of processing such as copying / scanning.

  The display unit 312 displays various modes and other displays. And various settings according to the display content can be performed by the touch panel. For example, the display unit 312 is provided with a tab button 314 for basic / applied settings that are normally performed when a copy operation or a scan operation is executed. When each tab button is pressed, a hierarchical screen for performing detailed setting is displayed. In this example, a case where an application tab button is pressed is shown, and detailed setting instructions for various post-processing in the post-processing device FS are possible. Specifically, “booklet mode”, “binding margin mode”, “folding mode”, and “staple mode” can be designated, but detailed description thereof will be omitted.

  In this example, a case where a tray discharge mode switching button 316 is provided is shown. The tray discharge mode can be designated by pressing the tray discharge mode switching button 316. Here, a sheet alignment conveyance mode and a sheet bundle conveyance mode, which will be described later, are illustrated as tray discharge modes for simplifying the description.

(Sheet alignment transport mode)
FIG. 10 is a flowchart of the sheet alignment conveyance mode according to the embodiment of the present invention. This process is executed by the CPU 201 controlling the conveyor belt motor 97.

  Referring to FIG. 10, in the sheet alignment conveyance mode, first, it is determined whether or not it is the sheet discharge timing (step S2). The CPU 201 determines whether or not the folded sheet S processed by the folding unit 50 is the discharge timing based on the output of the first folded plate sensor 59 or the second folded plate sensor 61.

  If it is determined in step S2 that it is the sheet discharge timing (YES in step S2), the conveyor belt is rotated forward (step S4). Specifically, immediately before the folded sheet comes into contact with the sheet tray 800, the conveyor belt motor 97 is instructed to rotate the conveyor belts 827A and 827B in the forward direction (discharge direction).

  Next, it is determined whether or not the sheet tray entrance sensor 38 is ON (step S6). The CPU 201 determines whether or not the sheet tray entrance sensor 38 provided at the position where the folded sheet is discharged to the sheet tray 800 is ON.

  If it is determined in step S6 that the sheet tray entrance sensor 38 is ON (YES in step S6), the state is maintained, and the sheet tray entrance sensor 38 is turned off while the transport belt is rotated forward. Determine whether or not.

  In step S6, the conveyance belt is rotated forward until the sheet tray entrance sensor 38 is turned off, and when the sheet tray entrance sensor 38 is turned off (NO in step S6), the conveyance belt is stopped (step S8). .

  Then, it is determined whether there is a next job (step S10). If there is a next job, the process returns to step S2 to repeat the above processing. On the other hand, if there is no next job, the process ends (END). In step S10, if it is determined that the sheet tray leading edge sensor 39 is turned on and a predetermined number of copies have been output, the processing may be terminated.

  That is, in the sheet alignment conveyance mode, when the folded folded sheet reaches the sheet tray 800 at the sheet discharge timing, the above-described movable member 824 moves, so that the sheet tray entrance sensor 38 is turned on. Then, the discharged folded sheet is conveyed by the conveyance belt until the sheet tray entrance sensor 38 is turned off, and when the rear end portion of the discharged folded sheet passes through the movable member 824, the movable member 824 is Return to the initial position. That is, the sheet tray entrance sensor 38 is turned OFF, and the conveyance belt stops at that position. Again, at the sheet discharge timing of the next job, the folded sheet discharged turns on the movable member 824 and the sheet tray entrance sensor 38. For example, when the movable member 824 is provided in the central portion of the discharged folded sheet, the folded sheet discharged before and the folded sheet discharged next overlap each other by half the length. . By repeating this process, the folded sheets discharged at regular intervals are overlapped and aligned and conveyed. In other words, the sheet alignment conveyance mode is a conveyance mode in which the folded sheet is conveyed by moving (stepping) the conveying belt by a predetermined distance every time the folded sheet is discharged.

  FIGS. 11 and 12 are diagrams illustrating a state in which the sheets S are stacked on the sheet tray 800. FIG.

  FIG. 11A shows a case where a plurality of sheets S are placed on the sheet tray 800.

  In this state, when the conveyance belt of the sheet tray 800 is rotated forward, a state in which a plurality of sheets are stacked via the stopper member 822 is shown as shown in FIG.

  FIG. 12A shows a state in which a 13-sheet sheet bundle composed of one sheet S is placed on the sheet tray 800. In this state, in order to collect the sheet S from the sheet tray 800, the user has to collect 13 sheets of sheet bundles.

  On the other hand, FIG. 12B shows a case where the number of overlapping parts is set to five. An example is shown in which five sheets of sheet bundles are stacked one by one, conveyed by the conveyor belts 827A and 827B and then discharged while being shifted. In FIG. 12B, a total of 30 sheet bundles can be stacked on the sheet tray 800, and the user can easily collect the sheets S from the sheet tray 800. In the present embodiment, the sheet S is easily collected from the sheet tray 800 by stacking the sheet bundle according to the number of overlapped sheets and then transporting the sheet bundle by the transport belts 827A and 827B.

(Sheet bundle conveyance mode)
FIG. 13 is a flowchart of sheet bundle discharge processing according to the number of overlapping copies according to this embodiment. When the sheet bundle conveyance mode is designated, the processing is executed. In this process, an overlay counter is used as a variable for counting the sheet bundle discharged from the saddle 100 to the sheet tray 800. It is assumed that the value of the overlap counter is initialized to 0 at the start of processing.

  Referring to FIG. 13, first, CPU 201 determines whether or not to accept a sheet S discharge request from saddle 100 (step S1). That is, the CPU 201 determines the discharge request of the folded sheet S processed by the folding unit 50 based on the output of the first folded plate sensor 59 or the second folded plate sensor 61. The process waits in step S1 until the discharge request is accepted.

  If it is determined that the discharge request has been received (YES in step S1), it is determined whether there is an instruction to switch jobs based on the input via the communication interface 87 (step S3). The job switching instruction is based on, for example, a print / print job switching instruction from the operation panel 13.

  If it is determined in step S3 that the job has been switched (YES in step S3), a sheet tray belt conveyance driving process is executed (step S13). Details of the sheet tray belt conveyance driving process will be described later. Thereafter, the value of the overlay counter is set to 0 (step S15), and the process returns to step S1.

  On the other hand, if it is determined that there is no job switching (NO in step S3), the number of overlapping copies is acquired (step S5). Details of acquiring the number of overlapping copies will be described later.

  Subsequently, the CPU 201 compares the number of overlapping copies with the value of the overlapping counter, and determines whether or not the condition (the number of overlapping copies> the value of the overlapping counter) is satisfied based on the comparison result (step S7). . If it is determined that the condition is not satisfied (NO in step S7), the process proceeds to step S13.

  On the other hand, if it is determined that the above condition is satisfied (YES in step S7), the CPU 201 stops the conveyor belt motor 97. That is, the bundle of sheets S is discharged from the saddle 100 to the sheet tray 800 while the conveyance belts 827A and 827B are stopped (step S9). When it is determined that the sheet bundle is discharged to the sheet tray 800, that is, when it is determined that a predetermined time has elapsed since the first folded plate sensor 59 or the second folded plate sensor 61 is turned on, the CPU 201 determines the value of the overlay counter. Is incremented (step S11), and the process returns to step S1.

  In this way, each time the sheet bundle is discharged to the sheet tray 800 by a predetermined number of overlapping sheets, the conveyance belt motor 97 moves the conveyance belts 827A and 827B, and the superimposed sheet bundle on the sheet tray 800 is conveyed. The When a predetermined instruction is input and the job detects switching, the conveying belts 827A and 827B are moved by the conveying belt motor 97 even if the number of overlapped sheets has not been reached, and the superimposed sheets on the sheet tray 800 are overlapped. A bundle is conveyed. As a result, as shown in FIG. 12, a stack of sheets stacked by the number of overlapping copies can be stacked and conveyed on the sheet tray 800 while being shifted from each other by a predetermined number of overlapping copies or for each job.

Next, details of the above-described process for acquiring the number of overlapping copies (step S5) will be described.
In the present embodiment, the number of overlapped sheets of the sheet bundle may be acquired based on a user operation from the operation panel 13. Here, the number of overlapped sheets is the number of bundles, paper media, folding mode, print mode, In the following description, it is determined based on temperature and humidity.

  The paper medium indicates information unique to the sheet S, and in the present embodiment, indicates the thickness and weight of the paper. The folding mode refers to either a two-fold (saddle stitching) mode or a three-fold mode. The print mode indicates either color printing or monochrome (black and white) printing. The temperature and humidity refer to the temperature and humidity measured by the temperature sensor 111 and the humidity sensor 112. Note that the number of bundles, paper media, folding mode, and print mode are input, for example, for each job by a user operation via the operation panel 13. The main control unit 150 acquires these pieces of information from a user operation on the operation panel 13 and transmits them to the CPU 201 of the finisher control unit 200. The CPU 201 receives the information.

  In the present embodiment, the number of overlapping parts is determined based on these conditions for the following reason. That is, if the number of bundles increases or the sheet S is thick paper, the crease becomes weak and the folded sheet swells and becomes bulky, so it is not preferable to increase the number of overlapping parts. Further, in the case of bi-folding (saddle stitching), the thickness of the sheet bundle itself can be reduced by the number of times of folding compared to tri-folding, and the number of overlapping parts can be increased.

  In the present embodiment, the degree of curling (curving) of the sheet S is also considered in determining the number of overlapping portions. In the present embodiment, a state in which the degree of curling of the sheet S (hereinafter also referred to as curl degree) is large is referred to as “curl strength”, and a state in which the sheet S is small is referred to as “curl weakness”. The curl degree is determined from the print mode, paper media, temperature, and humidity.

  Further, curling is also caused by a temperature difference between the heating roller 41 and the pressure roller 42 of the fixing device 7. Specifically, when the sheet S is conveyed to the fixing device 7, the toner is fixed to the sheet S by heat and pressure at the nip portion between the heating roller 41 and the pressure roller 42. In the fixing process, since the surface temperature of the heating roller 41 is higher than that of the pressure roller 42, a large amount of moisture in the sheet S evaporates from the heating roller 41 side, and the evaporation amount from the pressure roller 42 side is relatively large. Very few. As a result, the moisture on the heating roller 41 side in the sheet S decreases, the moisture on the pressing roller 42 side increases, and the moisture in the central portion of the sheet S and the pressing roller 42 moves to the heating roller 41 side at once. To do.

  As a result, the heating roller 41 side of the sheet S expands due to the collected water, and the pressure roller 42 side contracts due to the reduced water content. This expansion and contraction causes the sheet S to curl.

  Regarding the curl degree, a thick paper sheet S containing a lot of moisture is more likely to curl than a thin paper sheet S, and color printing that requires a high fixing temperature is easier to curl than monochrome printing. Also, curling is easier in high temperature and high humidity environments.

  Therefore, in the present embodiment, the CPU 201 determines the strength of the curl degree from the print mode, the paper medium, the temperature, and the humidity as follows.

  Here, the thickness of the sheet S indicated by the paper medium has a relationship of thin paper <plain paper <thick paper <thick paper (2).

  If the sheet S is thin paper or plain paper, it is determined as “curl weak” if the temperature is 30 ° C. or higher, the humidity is 70% or higher and color printing is performed, and “curl weak” is determined otherwise.

  When the sheet S is thick paper or thick paper (2), it is determined as “curl weak” if the temperature is 30 ° C. or higher, the humidity is 50% or higher and color printing is performed, and “curl weak” is determined otherwise.

  A method for determining the conveyance speed V and the additional conveyance distance AD for conveying the sheet bundle superimposed on the sheet tray 800 will be described with reference to the table TB1.

  The table TB1 in FIG. 14 includes a plurality of different sets PA each including the number of bundles NB, the paper medium, the curl degree (strong and weak) determined as described above, and the folding mode (middle folding and trifolding). Corresponding to PA, a conveyance speed V (unit: mm / sec) and an additional conveyance distance AD (unit: mm) are stored in advance. The transport speed V and the additional transport distance AD corresponding to each set PA in the table TB1 are acquired in advance through experiments or the like. Note that, as indicated by the symbol (* 1) in the table TB1, in the present embodiment, the transport speed V is 50 mm / sec when the number of bundles NB is “1” regardless of the conditions indicated by the set PA. The additional transport distance AD is 0 mm.

(Conveyor belt drive processing)
Next, the conveyance belt driving process (step S13) will be described in detail.

  On the sheet tray 800, the sheet bundle is conveyed in the state where the number of overlapping sheets is overlapped. In this way, a sheet bundle that is overlapped by the number of overlapping portions is referred to as a “group”.

  There is a case where the position of the sheet bundle of the group is shifted during conveyance, or the sheet bundle that is shifted and protrudes from the group is mixed into another group. Since a group of sheet bundles is generally output for each job, mixing in this way makes it impossible to determine the sheet bundle for each job on the sheet tray 800.

  Therefore, in the present embodiment, the sheet belt position shift as described above is prevented by slowing the conveying speed of the conveying belts 827A and 827B. In addition, after the group is formed by stacking the sheet bundle, the conveyance distance by the movement of the conveyance belts 827A and 827B is increased, and the interval between the adjacent groups is increased. Thereby, even if the position of the sheet bundle shifts and protrudes from the group, the user can distinguish from the sheet bundle of another group.

  In order to realize this, when the CPU 201 determines that the sheet tray entrance sensor 38 is turned off and the discharge of the group of sheet bundles is completed, the CPU 201 controls the conveyance belt motor 97 to control the conveyance belts 827A and 827B. The transport belts 827A and 827B are stopped after transporting by the additional transport distance AD of the table TB1. Details of the processing in step S13 are shown in FIG.

  FIG. 15 is a process flowchart for controlling the conveyance by the conveyance belts 827A and 827B according to the present embodiment.

  Referring to FIG. 15, first, CPU 201 searches table TB1 and reads transport speed V and additional transport distance AD as described above. Thereby, the conveyance speed V and the additional conveyance distance AD are determined (steps S21 and S23).

  The CPU 201 determines that a sheet bundle has been discharged from the saddle 100 by detecting that a predetermined time has elapsed since the turning on of the first or second folded plate sensor 59 or 61 (step S25). The process of step S25 is repeated until it is determined that it has been discharged.

  If it is determined that the sheet is discharged (YES in step S25), the CPU 201 instructs the conveying belt motor 97 to rotate the conveying belts 827A and 827B in the forward direction (discharging direction) and at the conveying speed V determined in step S21. The movement is started (step S27). As a result, conveyance of a group of sheet bundles already stacked on the sheet tray 800 is started.

  Thereafter, the CPU 201 determines whether or not the sheet tray entrance sensor 38 is turned off (step S29). The processing in step S29 is repeated until it is determined that the group of sheet bundles has been conveyed and the sheet tray entrance sensor 38 has been turned off. That is, the conveyance is performed at the conveyance speed V while it is determined to be ON. As a result, the sheet bundle superimposed on the sheet tray 800 by the number of overlapping copies is conveyed in the discharge direction according to the conveyance speed V.

  Thereafter, when the CPU 201 determines that the sheet tray entrance sensor 38 has been turned off (OFF in step S29), the CPU 201 instructs the conveyance belt motor 97 to carry out the additional conveyance acquired in step S23 at the conveyance speed V by the conveyance belts 827A and 827B. The sheet is further conveyed by the distance AD (step S31). Thereby, the group of sheet bundles discharged to the sheet tray 800 immediately before is further conveyed by the additional conveyance distance AD.

  When the conveyance is completed for the additional conveyance distance AD, the conveyance belt motor 97 outputs a drive completion signal. When the CPU 201 inputs a drive completion signal (YES in step S31), the CPU 201 instructs the conveyor belt motor 97 to stop the conveyor belts 827A and 827B (step S33). Above, the process of step S13 is complete | finished and it transfers to the process of step S15 of FIG.

  According to the processing in FIG. 15, the next group of sheet bundles can be placed and conveyed at the conveyance speed V at an interval corresponding to the additional conveyance distance AD on the sheet tray 800. Accordingly, it is possible to prevent the sheet bundle from being displaced on the sheet tray 800 because the conveyance speed is high. Further, even if the theta bundle is lost, the interval for each group can be set to a distance corresponding to the additional conveyance distance AD, so that it is possible to prevent a situation where the sheet bundle for each job (that is, for each group) cannot be determined. be able to.

(Adjustment of additional transport distance based on fixing tacking)
Here, the number of overlapping portions of each bundle in the sheet tray 800 may be determined in consideration of fixing tacking. In the fixing tacking, when the sheet S is discharged to the sheet tray 800 without drying the fixed toner (especially color toner), the toner becomes an adhesive and the sheets S stick to each other on the sheet tray 800. It refers to a phenomenon that becomes a state. When sheet bundles are overlapped as in this embodiment, fixing tacking is likely to occur.

  Generally, when an image having a high CW (color / white) ratio and BW (black / white) ratio is printed, fixing tacking is likely to occur, and the temperature around the fixing device 7 increases due to continuous printing. In this case, the toner on the sheet S is melted more than usual, so that fixing tacking is likely to occur.

  When the printed sheet S is discharged under such a condition that fixing tacking is likely to occur and left on the sheet tray 800 for a long time, the toner adheres with the weight of the sheet S (or sheet bundle). Resulting in. In addition, it is not possible to specify when the sheet S discharged to the sheet tray 800 is collected by the user.

  Therefore, if there is a possibility that the sheet is left on the sheet tray 800 for a long time, the bundle is not stacked, and the amount of overlap during conveyance is reduced. That is, the additional transport distance AD determined in step S23 is adjusted (updated). This update process will be described with reference to the flowchart of FIG. FIG. 16 shows a modification of the flowchart of FIG.

  FIG. 16 differs from the flowcharts of FIGS. 15 and 16 in that an additional conveyance distance AD adjustment process (step S24) considering fixing tacking is added between the processes of steps S23 and S25 of FIG. It is in the point. The other processes in FIG. 16 are the same as those in FIG.

  Referring to FIG. 16, when determining the additional transport distance AD as described above (step S23), the CPU 201 performs an adjustment process (step S24) of the additional transport distance AD. The table TB2 in FIG. 17 is searched for the adjustment process of the additional transport distance AD.

  The table TB2 in FIG. 17 includes a set of continuous printing time (less than 10 minutes, less than 10 minutes to less than 20 minutes, more than 20 minutes) and a CW ratio (less than 20%, more than 20%) representing the image density to be printed. Corresponding to each of these, information on whether or not fixing tacking occurs is stored in advance. Information in the table TB2 is acquired in advance for each model by experiment.

  17 indicates that fixing tacking does not occur regardless of the CW ratio if the continuous printing time is less than 10 minutes, and CW if the continuous printing time is less than 10 to 20 minutes. When the ratio is 20% or more, it indicates that fixing tacking occurs, and when the continuous printing time is 20 minutes or more, it indicates that fixing tacking occurs regardless of the CW ratio.

  The CPU 201 calculates a continuous printing time. Here, the continuous printing time is calculated based on a predetermined number of sheets to be printed and a print start command input based on a user operation on the operation panel 13. In the embodiment, since the predetermined time required to print an image on one sheet S is determined in advance, the time from the input of the print start command to the end of printing the predetermined number of sheets (that is, the predetermined number of sheets) X Predetermined time) is calculated as the continuous printing time.

  The CW ratio (or BW ratio) is acquired by image processing by the image processing unit 2, and the acquired CW ratio (or BW ratio) is given from the main control unit 150 to the CPU 201. Thereby, CPU201 acquires CW ratio (or BW ratio).

  In another method, the high / low ratio of the video signal related to the image to be printed may be measured, and the CW ratio may be calculated based on the measurement result.

  The CPU 201 searches the table TB2 based on the calculated continuous printing time and the acquired CW ratio, and reads the corresponding information on whether or not fixing tacking has occurred. If it is determined that the read presence / absence information indicates “no fixing tacking”, the CPU 201 ends the process without adjusting (updating) the additional transport distance AD determined in step S23, but if “fixing tacking” is indicated. When the determination is made, the CPU 201 adds α to the value of the additional transport distance AD determined in step S203, that is, read from the table TB1, and updates the value so that the value of the additional transport distance AD becomes larger. It is assumed that the value of “α” to be added is predetermined as a predetermined value.

  When the adjustment process (step S24) of the additional conveyance distance AD based on the presence or absence of occurrence of fixing tacking is completed, the subsequent process of step S25 is performed using the additional conveyance distance AD after the adjustment (or update). Although the table TB2 that can be searched based on the CW ratio is used here, similarly, a table that can be searched based on the continuous printing time and the BW ratio indicating the image density is prepared to determine the presence or absence of fixing tacking. You may do it.

  As described above, the CPU 201 instructs the conveyance motor 93 according to the adjusted additional conveyance distance AD, and controls the conveyance of the sheet S by the conveyance belts 827A and 827B, thereby superimposing the sheet bundles discharged to the sheet tray 800. It is possible to prevent the occurrence of fixing tacking.

  Note that which of the processes in FIGS. 15 and 16 is activated may be determined by an instruction based on a user operation via the operation panel 13.

  Further, it is desirable to determine the number of overlapping copies in consideration of the presence or absence of fixing tacking. That is, when determining the number of overlapping copies in step S5, if the table TB2 is searched as described above and it is determined that there is fixing tacking, the number of overlapping copies determined in step S5 is reduced ( Alternatively, the adjustment (update) may be performed so as not to overlap (the number of copies = 0), and if it is determined that there is no fixing tacking, the adjustment (update) process may be passed.

(Modification)
FIG. 18 is a process flowchart for determining the conveyance speed according to the present embodiment. FIG. 19 is a process flowchart for determining the additional conveyance distance according to the present embodiment. A modification according to the present embodiment will be described with reference to FIGS. In the modified example, the curl degree is acquired in the same manner as the above-described procedure.

  In FIGS. 15 and 16, the transport speed V and the additional transport distance AD are determined by searching the table TB1 (steps S21 and S23). However, instead of searching the table TB1, FIGS. It may be determined according to the process flowchart.

  In the modification, the process of FIG. 18 is executed in step S21. Referring to FIG. 18, CPU 201 determines a designated paper medium based on an input from operation panel 13 (step S41).

  If it is determined that the sheet S is “light paper”, the conveyance speed V is set to 40 mm / sec (step S43), and then the process proceeds to step S45.

  On the other hand, if the sheet S is determined to be “plain paper”, the curl degree acquired in advance is determined (step S49). When the curl degree is determined to be “weak”, 40 mm / sec is set to the conveyance speed V (step S51), and when the curl degree is determined to be “strong”, 30 mm / sec is set to the conveyance speed V ( Step S53), and then the process proceeds to Step S45.

  If the sheet S is determined to be “thick paper”, the curl degree acquired in advance is determined (step S55). When the curl degree is determined to be “weak”, 30 mm / sec is set to the conveyance speed V (step S57), and when the curl degree is determined to be “strong”, 20 mm / sec is set to the conveyance speed V ( Step S59), and then the process proceeds to Step S45.

  If the sheet S is determined to be “thick paper (2)”, the curl degree acquired in advance is determined (step S61). If the curl degree is determined to be “weak”, 20 mm / sec is set to the conveyance speed V (step S63), and if the curl degree is determined to be “strong”, 50 mm / sec is set to the conveyance speed V ( Step S65), and then the process proceeds to Step S45.

  In step S45, the bundle number NB is determined. If the bundle number NB is determined to be “1”, it is updated by setting the transport speed V to 50 mm / sec (step S47), but if it is determined that the number is greater than “1”, the step The process of S47 is passed and the conveyance speed V is not updated. Thereafter, the processing shifts to the original processing (step S23).

  In the modification, the process of FIG. 18 is executed in step S23. Referring to FIG. 19, CPU 201 determines a paper medium designated for sheet S based on an input from operation panel 13 (step S <b> 71).

  If it is determined that the sheet S is “light paper”, the additional transport distance AD is set to 30 mm (step S73), and then the process proceeds to step S75.

  On the other hand, if the sheet S is determined to be “plain paper”, the additional transport distance AD is set to 30 mm (step S79), and then the process proceeds to step S75.

  If the sheet S is determined to be “thick paper”, the curl degree acquired in advance is determined (step S81). When the curl degree is determined to be “weak”, 30 mm is set to the additional conveyance distance AD (step S83), and when the curl degree is determined to be “strong”, 50 mm is set to the additional conveyance distance AD (step S85). Thereafter, the process proceeds to step S75.

  If the sheet S is determined to be “thick paper (2)”, the curl degree acquired in advance is determined (step S87). If the curl degree is determined to be “weak”, 50 mm is set to the additional conveyance distance AD (step S89). If the curl degree is determined to be “strong”, 0 mm is set to the additional conveyance distance AD (step S91). Thereafter, the process proceeds to step S75.

  In step S75, the bundle number NB is determined. If it is determined that the number of bundles is “1”, the additional transport distance AD is updated by setting 0 mm (step S77). If it is determined that the number of bundles is greater than “1”, step S77 is performed. The process is passed and the additional transport distance AD is not updated. Thereafter, the processing shifts to the original processing (step S24 or S25).

  According to the processing flowcharts of FIGS. 18 and 19, the transport speed V and the additional transport distance AD can be determined without using the table TB1.

  The embodiment disclosed this time 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.

  1A image sensor, 2 image processing section, 13 operation panel, 38 sheet tray inlet sensor, 39 sheet tray leading edge sensor, 50 folding section, 97 transport belt motor, 100 saddle, 111 temperature sensor, 112 humidity sensor, 150 main control section, 800 sheet tray, 821A belt conveyance roller, 827A, 827B conveyance belt, A image forming apparatus, AD additional conveyance distance, FS post-processing apparatus, NB bundle number, PA group, S sheet, TB1, TB2 table, V conveyance speed.

Claims (7)

A sheet processing apparatus for processing a sheet after an image is formed by printing of the image forming apparatus,
A sheet folding section for generating a sheet bundle by folding one or more sheets after the image formation;
A sheet tray to be stacked to take out the sheet bundle folded by the sheet folding unit;
A control unit for controlling the sheet tray,
The sheet tray includes a conveyance belt that conveys the sheet bundle,
The controller is
In a state where the transport belt is stopped, the sheet bundle is overlapped with a predetermined number of sheets and discharged to the sheet tray, and then the transport belt is moved by a predetermined distance,
The controller is
Based on the number of sheets of the sheet bundle, the sheet attributes, the folding mode indicating the folding mode, the printing mode indicating the printing mode, and the temperature and humidity in the environment where the sheet processing apparatus is installed, the predetermined number of copies is determined. The sheet processing apparatus to be determined. The controller is
2. The sheet processing apparatus according to claim 1, wherein when a predetermined instruction is input in a process in which the sheet bundle is overlapped and discharged to the sheet tray in a state where the conveyance belt is stopped, the conveyance belt is moved by a predetermined distance.   The sheet processing apparatus according to claim 2, wherein the predetermined instruction indicates a print job switching instruction by the image forming apparatus. The controller is
The speed at which the predetermined number of the stacked sheet bundles are conveyed by the movement of the conveying belt is determined based on the number of sheets, the sheet attributes, the folding mode, the printing mode, the temperature, and the humidity. The sheet processing apparatus according to claim 1. The controller is
5. The sheet processing apparatus according to claim 1, wherein the predetermined distance is determined based on the number of sheets, the attribute of the sheet, the folding mode, the printing mode, the temperature, and the humidity. The controller is
The predetermined distance is determined based on the number of sheets, the sheet attributes, the folding mode, the printing mode, the temperature, the humidity, the continuous printing time by the image forming apparatus, and the image density. The sheet processing apparatus according to any one of 4. The controller is
The predetermined number of copies is determined based on the number of sheets, the sheet attributes, the folding mode, the printing mode, the temperature, the humidity, the continuous printing time by the image forming apparatus, and the image density. The sheet processing apparatus according to claim 6.

Images