JP2009067595A - Sheet stacking apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent curling and bending of sheets supported in a standing position to maintain alignment of the sheets. <P>SOLUTION: Sheets conveyed one by one are supported by a stack tray in the standing position, and lower ends of the sheets supported by the stack tray are received by a stacker of a stack part. An assisting member is rotated to the stack tray side and made abut on the conveyed sheets so as to encourage accumulation of the sheets on the stack tray. A pressing member driven and rotated by the rotation of the assisting member is used, and when the assisting member is rotated to a waiting position and separated from the sheets supported by the stack tray, the pressing member is made abut on lower ends of the sheets to push them against the stack tray side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a paper stacking device for stacking transported paper.

  A paper post-processing apparatus that performs processing such as binding and folding is disclosed in Japanese Patent Application Laid-Open No. 2004-133830.

The apparatus includes a sheet stack for placing sheets for automatic stapling and the like, and at least one finger that is movably mounted on the mount and defines a major surface that contacts the top sheet of the sheet stack in parallel. And the mount is movable relative to the stack so that the fingers continue to contact in parallel as the sheets in the stack increase. The weight of the finger prevents the sheet from being bent or bent in the stacking tray.
JP-A-2005-330108

  However, in the above apparatus, the sheet is kept in contact with the sheet in parallel by the weight of the finger, and the sheet stack is configured such that the sheet is laid down. Therefore, it cannot cope with the bending or bending of the lower end of the sheet when the sheet is supported in a standing position.

  In addition to the means for driving the stacking belt that promotes the stacking of sheets, there is a problem that a motor, a solenoid, and the like that move the fingers are required separately.

  Therefore, an object of the present invention is to provide a paper stacking device that can suppress the deflection and bending of the paper supported in the standing position and can maintain the consistency of the paper.

  In order to achieve the above object, a paper stacking apparatus according to the present invention includes a storage member that supports paper conveyed one by one in a standing position, a receiving member that receives a lower end of the paper supported by the storage unit, An auxiliary member that abuts on the sheet that has been rotated and conveyed from the predetermined position to the accumulation member side, assists the accumulation of the sheet in the accumulation means, and is driven by the rotation of the auxiliary member via the mounting portion. When the auxiliary member rotates toward the storage member and comes into contact with the paper supported by the storage member, the auxiliary member is separated from the lower end of the paper, and the auxiliary member is moved to the predetermined position. And a pressing member that contacts the lower end of the sheet and presses it toward the storage member when the sheet is separated from the sheet supported by the storage member.

  According to the present invention, it is possible to provide a paper stacking apparatus that can suppress the deflection and bending of the paper supported in the standing position and maintain the paper alignment.

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

[First Embodiment]
FIG. 1 is a schematic configuration diagram of an image forming apparatus.

  The image forming apparatus 1 includes an image reading unit 2 that reads an image to be read and an image forming unit 3 that forms an image. In addition, the image forming apparatus 1 includes an operation panel 5 having a touch panel display 6 and various operation keys 7.

  The operation keys 7 of the operation panel 5 include, for example, a numeric keypad, a reset key, a stop key, a start key, and the like. In the display unit 6, for example, various instructions such as paper size, number of copies, print density setting, and binding / folding are input.

  The image reading unit 2 includes a document table 8, a carriage 9, an exposure lamp 10, a reflection mirror 11, an imaging lens 12 that converges the reflected light, and a CCD 13 (Charge Coupled) that is a photoelectric conversion element that takes the reflected light and converts it into an electrical signal. Device). Above the document table 8 is an automatic document feeder 30 that conveys the document to the reading position.

  The image forming unit 3 includes an intermediate transfer belt 14 as a transfer member, and yellow (Y), magenta (M), cyan (C), and black (K) colors arranged along the intermediate transfer belt 14. Four process units 16Y, 16M, 16C, and 16K corresponding to toner are provided.

  The process unit 16K includes a photoconductor 18K as an image carrier, a laser unit 20K that forms an electrostatic latent image on the photoconductor 18K, a charging device 22K that is sequentially cast around the photoconductor 18K, a developing device 24K, and an intermediate transfer. A primary transfer device 26K, a cleaner 27K, and a static elimination lamp 28K that face the photosensitive drum 8K across the belt 14 are provided. The process units 16Y, 16M, and 16C have the same configuration as the process unit 16K. The following description will be made with reference to the black (K) process unit 16K.

  First, the document is placed on the reading position of the document table 8 or the automatic document feeder 30 conveys the document to the reading position. Subsequently, the exposure lamp 10 supported by the carriage 9 applies light to the original from below the original table 8. The reflection mirror 11 guides the reflected light from the document to the imaging lens 12. The imaging lens 12 projects an image of reflected light from the document onto the CCD 13. The CCD 13 takes in the reflected light and outputs the image information of the document as an analog signal. The electrical signal transmitted by the CCD 13 is converted into a digital signal. The laser unit 20K receives a digital signal subjected to image processing.

  When image formation is started in the image forming unit 3, the charging device 22K charges the outer peripheral surface of the rotating photoreceptor 18K. In order to form an electrostatic latent image on the outer peripheral surface of the photoreceptor 18K charged to a uniform potential in the axial direction by the charging device 22K, the laser unit 20K irradiates a laser beam in accordance with the digital signal subjected to image processing. . The developing device 24K supplies black developer (for example, toner) to the outer peripheral surface of the photoreceptor 18K, and develops the electrostatic latent image into a toner (K) image. The primary transfer device 26K electrostatically transfers the toner (K) image to the intermediate transfer belt 14.

  Toner remaining on the photosensitive member 18K without being transferred is removed by the cleaner 27K at a position downstream of the primary transfer device 26K in the rotation direction of the photosensitive member 18K. Residual charges on the outer peripheral surface of the photoconductor 18K are removed by the static elimination lamp 28K downstream of the cleaner 27 in the rotation direction of the photoconductor 18K. In color image formation, the above operations are similarly performed by the process units 16Y, 16M, and 16C.

  The toner image transferred to the intermediate transfer belt 14 is electrostatically transferred by the secondary transfer device 36 onto the paper transported from the paper feeding device 32 through the transport path 34. The fixing device 38 fixes the toner image on the sheet. The sheet on which the toner image is fixed is conveyed to the conveyance roller 40.

  To perform duplex printing, the transport roller 40 rotates in the reverse direction and transports the paper to the transport path 42. The secondary transfer device 36 transfers the toner image to the opposite surface of the sheet conveyed to the conveyance path 42. The fixing device 38 fixes the toner image on the sheet.

  The conveyance roller 40 discharges the sheet on which the toner image is fixed to the sheet post-processing device 4. Note that the paper here refers to, for example, plain paper, thick paper, thin paper, glossy paper, or an OHP sheet. Further, the image forming unit 3 may be an ink jet system other than the above system.

  Next, the paper post-processing device 4 will be described. FIG. 2 is a schematic diagram of the sheet post-processing apparatus.

  The sheet post-processing device 4 processes the sheet discharged from the image forming apparatus 1 in accordance with an input instruction from the operation panel 5 or an instruction from the PC. The sheet post-processing device 4 includes, for example, an end binding processing unit 50 that sorts the sheet bundle and binds the end of the sheet bundle, and a folding processing unit 60 that folds and binds the sheet bundle. The end binding processing unit 50 may be, for example, a post-processing device described in Japanese Patent Application Laid-Open No. 2007-76862.

  The folding processing unit 60 includes a conveyance roller 63, a carry-out roller 64, a carry-out roller sensor 65, an auxiliary member 70, and a stacking unit 80. The conveyance roller 63 conveys the sheet toward the stacking unit. The carry-out roller sensor 65 carries out the paper to the stacking unit 80. The carry-out roller sensor 65 detects the conveyed paper. The auxiliary member 70 assists the stacking of sheets. The stacking unit 80 stacks sheets temporarily in a standing position.

  The stacking unit 80 includes a stack tray 82, a stack unit 90, a lateral alignment member 100, a stapler 110, and a folding mechanism 120. The stack tray 82 supports the sheet surface. The stack unit 90 receives the rear end in the paper transport direction. The lateral alignment member 100 performs lateral alignment of the sheet bundle. The stapler 110 binds the aligned sheet bundle. The folding mechanism 120 folds the bound sheet bundle.

  The folding processing unit 60 includes a sheet bundle stacking tray 500 for stacking post-processed sheet bundles downstream of the stacking unit 80 in the sheet conveyance direction.

  First, the flow of paper post-processing will be briefly described.

  The entrance roller 61 carries the paper fed from the transport roller 40 of the image forming apparatus 1 into the paper post-processing device 4. The branching member 62 guides the sheet carried by the entrance roller 61 to the folding processing unit 60 when folding or binding is instructed. The sheet is conveyed by the conveyance roller 63, and the carry-out roller 64 is carried out to the stacking unit 80.

  In the stacking unit 80, the stack unit 90 receives the leading end in the conveyance direction of the unloaded paper, and the stack tray 82 supports the lower surface of the sheet. The stack unit 90 supports the lower end of the sheets stacked in a standing position, and aligns the position of the end (lower end) of the sheets in the transport direction. Hereinafter, in the stacking unit 80, the rear end in the paper transport direction is the lower end of the paper, and the front end in the paper transport direction is the upper end of the paper.

  When the paper is discharged to the stacking unit 80, the auxiliary member 70 rotates from a position apart from the paper and comes into contact with the paper. The auxiliary member 70 prompts the lower end of the sheet to abut against the stack unit 90.

  The sheets stacked on the stacking unit 80 are also aligned in the sheet width direction, which is the direction intersecting the sheet transport direction. Hereinafter, the alignment in the width direction of the sheet is referred to as lateral alignment. The configuration for performing horizontal alignment will be described later.

  The stack unit 90 moves up and down along the stack tray 82 and adjusts the position of the sheet bound by the stapler 110 and the position of the sheet folded by the folding mechanism 120. In this embodiment, as an example, a description will be given assuming that a sheet binding portion or a folding portion is a central portion in the sheet conveyance direction.

  When the stack unit 90 receives a series of sheets and forms a bundle of sheets, the stack unit 90 moves so that the position where the sheets are bound is located at the position where the stapler 110 is bound.

  A plurality of (for example, two) staplers 110 are arranged in the width direction of the sheet. The stapler 110 has a stapler head 112 and an anvil 114. When the stack unit 90 stops the position where the sheets are bound at the position where the stapler 110 binds, the stapler head 112 and the anvil 114 bind the sheet bundle. The stack unit 90 may stand by at a position where the central portion of the sheet comes to the binding position of the stapler 110 in order to receive the sheet.

  When the stapler 110 binds the bundle of sheets, the stack unit 90 moves so that the bound position of the sheets comes to the position where the folding mechanism 120 is folded. When the stack unit 90 stops, the folding mechanism 120 starts folding.

  The folding mechanism 120 includes a folding plate 122 and a folding roller pair 124. The folding plate 122 stands by at a position that does not hinder the conveyance of the paper. The folding plate 122 moves toward the folding roller pair 124 to fold the paper. The folding plate 122 pushes the paper toward the nip portion of the folding roller pair 124. The pair of folding rollers 124 folds the paper pressed by the folding plate 122 with nipping and conveying.

  The discharge roller 126 discharges the sheet bundle folded by the folding mechanism 120 to the sheet bundle stacking tray 500.

  Next, the control system of the image forming apparatus and the sheet post-processing apparatus will be briefly described. FIG. 3 is a schematic block diagram of the control system of the image forming apparatus and the sheet post-processing apparatus.

  The image forming apparatus 1 includes a main control unit 300. The main control unit 300 controls the image reading unit 2, the image forming unit 3, the operation panel 5, and the control unit 310 of the sheet post-processing device 4. The main control unit 300 further corrects, compresses, and decompresses the image data. The main control unit 300 further stores compressed image data, print data, and the like. The main control unit 300 further communicates with a PC (Personal Computer) 320 outside the image forming apparatus 1.

  Based on an instruction from the main control unit 300, the control unit 310 of the sheet post-processing device 4 performs the entrance roller 61, the branch member 62, the transport roller 63, the auxiliary member 70, the stack unit 90, the stapler 110, the folding mechanism 120, the lateral alignment. The operation of the member 100 is controlled.

  FIG. 4 is a schematic diagram for explaining the stack unit 90. FIG. 5 is a schematic view for explaining the lateral alignment member 100, and is a view seen from the direction of arrow A in FIG.

  As illustrated in FIG. 4, the stack unit 90 includes a stacker 91, a stack unit 92, and a drive unit 95. The stacker 91 receives the lower end of the sheet. The stack unit 92 supports the stacker 91. The drive unit 95 moves the stack unit 92 up and down. The drive unit 95 includes a rail 96, a pulley 97, a belt 98, and a motor M1. The rail 96 guides the stack unit 92 up and down along the sheet conveyance direction. The belt 98 is wound around the pulley 97. The belt 98 is connected to the stack unit 92. The motor M1 rotates the belt 98 via the pulley 97. The belt 98 moves the stack unit 92. The motor M1 may be a stepping motor.

  The first detection means 93 detects the position of the stacker 91. The first detection means 93 may be, for example, a microsensor or a microactuator. In the present embodiment, the first detection means 93 detects the home position (hereinafter referred to as the first HP) of the stack unit 92. The vertical movement of the stacker 91 is controlled by the number of pulses given to the motor M1 for driving based on the first HP. As an example, in the present embodiment, the stacker 91 waits for a conveyed sheet at a position where the central portion of the received sheet in the vertical direction is at the binding position (the standby position of the stacker 91). The stacker 91 includes a sheet lower end detection unit 99 that detects that the lower end of the sheet has reached the stacker 91. The paper lower end detection means 99 may be a micro sensor or a micro actuator, for example.

  The auxiliary member 70 includes a shaft 71, an arm 72, and an assist roller 73. The shaft 71 supports the arm 72. The arm 72 supports the assist roller 73 rotatably at the tip. The auxiliary member 70 rotates the shaft 71 to the branch. For example, the solenoid S rotates the shaft 71. In the present embodiment, the solenoid S rotates the auxiliary member 70. The assist roller 73 contacts the paper discharged to the stacking unit 80. The assist roller 73 rotates so that the lower end of the sheet abuts against the stack unit 90.

  As shown in FIG. 5, the stacking unit 80 includes a lateral alignment member 100 above the stack unit 90. The lateral alignment member 100 includes alignment members 102a and 102b, horizontal members 104a and 104b, a pinion gear 106, and a motor M2.

  The alignment members 102a and 102b face each other in parallel, and align the end portions (lateral ends) in the width direction of the sheets stacked on the stack portion 90.

  The horizontal members 104a and 104b are connected to the alignment members 102a and 102b, respectively. The horizontal members 104a and 104b face each other in parallel. The horizontal members 104a and 104b each have a rack on the opposing surface. The pinion gear meshes simultaneously with the racks of the horizontal members 104a and 104b. The motor M2 rotates the pinion gear 106 through the gear 107. The pinion gear 106 rotates so that the horizontal members 104a and 104b slide in opposite directions in the paper width direction. The motor M2 may be a stepping motor, for example. The second detection means 108 detects the position of the alignment members 102a and 102b in the sheet width direction. The second detection means 108 may be, for example, a microsensor or a microactuator. In the present embodiment, the second detection means 108 detects that the alignment members 102a and 102b are open in the width direction (home position, hereinafter referred to as second HP). The positions of the alignment members 102a and 102b are controlled by the number of pulses given to the motor M2 for driving with reference to the second HP. In the stacking unit 80, when a binding process instruction is issued from the operation panel 5 or the PC 320, when the lateral alignment member 100 performs alignment in the sheet width direction, the saddle stitcher stapler 112 and the anvil 114 bind the sheet bundle. When a binding instruction is input from the operation panel 5 or the PC 320, the lateral alignment member 100 is laterally aligned, and then the stapler head 112 and the anvil 114 of the stapler 110 bind the sheet bundle.

  Next, the operation of the lateral alignment member 100 will be described with reference to FIGS. FIG. 6A shows a state in which the alignment members 102a and 102b are in the first position. In an ideal transport posture, the sheet is transported in a state where the center of the interval between the alignment members 102a and 102b and the center of the transported sheet P1 in the width direction coincide with each other. Each of the alignment members 102a and 102b stands by at a first position that is a first distance away from the lateral edge of the paper P1 that is transported in an ideal transport posture. The first distance may be 15 mm, for example. The first position may be a position where the alignment members 102a and 102b are moved from the second HP by applying a predetermined number of pulses to the motor M2 and rotating it.

  The aligning members 102a and 102b move in the direction indicated by the arrow B in FIG. 6B so as to approach the lateral end of the sheet P1 being conveyed, and horizontally align the sheet P1. For example, the alignment members 102a and 102b move so that the lower end of the paper P1 reaches between the alignment member 102a and the alignment member 102b and then approaches the lateral edge of the paper P1. For example, the alignment members 102a and 102b move to a second position where the distance between the alignment members 102a and 102b is equal to the length in the width direction of the sheet (second distance) for the purpose of lateral alignment.

  After the horizontal alignment, as indicated by an arrow C in FIG. 6C, the alignment members 102a and 102b move to a third position that is a third distance away from the horizontal edge of the sheet. The alignment members 102a and 102b wait for the subsequent sheet P2 at the third position. The third distance may be shorter than the first distance. The third distance may be 3 mm, for example.

  The alignment members 102a and 102b move in the direction indicated by the arrow D in FIG. 6D so as to approach the lateral edge of the conveyed paper P2, and laterally align the paper bundle including the paper P1 and the paper P2. The alignment members 102a and 102b move so that, for example, the lower end of the paper P2 reaches between the alignment member 102a and the alignment member 102b and then approaches the lateral edge of the paper P2. The alignment members 102a and 102b move, for example, to the second position for lateral alignment. The horizontal alignment member 100 repeats the above operation every time a sheet is conveyed, and horizontally aligns the sheet bundle including the sheets P1 and P2 and the subsequent sheets.

[Embodiment of lateral alignment operation]
The operation of the lateral alignment member 100 will be described with reference to FIGS. 7 is a flowchart of the operation of the lateral alignment member 100, and FIG. 8 is a timing chart of each member corresponding to the flowchart of FIG.

  By inputting an instruction such as the number of copies of the sheet bundle or binding / folding with the operation key 7 and pressing the start key, the main control unit 300 of the image forming apparatus 1 is driven to the control unit 310 and the motors M1 and M2 are driven at 701. To start.

  In 702, the stacker 91 moves to the standby position of the stacker 91. The alignment members 102a and 102b move to the first position. If the stacker 91 is already in the standby position of the stacker 91, the motor M1 does not move at 701, and the stacker 91 does not move and waits for paper. If the alignment members 102a and 102b are already in the first position, the motor M2 does not move at 701, and the alignment members 102a and 102b do not move and wait for a sheet.

  In 703, when the carry-out roller sensor 65 detects the leading edge of the sheet conveyed by the conveyance roller 63, the output rises from a low level to a high level. Subsequently, when the carry-out roller sensor 65 detects the trailing edge of the sheet, in 704, the output falls from the high level to the low level.

  In 705, the control unit 310 causes the auxiliary member 70 to contact the paper in 706 after a predetermined time has elapsed since the output of the carry-out roller sensor 65 fell. The predetermined time may be set in advance so that the assist roller 73 comes into contact with the conveyed paper. The controller 310 may contact the auxiliary member 70 with the sheet after giving a preset number of pulses to the drive motor of the transport roller 63 after the output of the carry-out roller sensor 65 falls.

  In step 707, the process waits for a predetermined time after the auxiliary member 70 contacts the paper. The predetermined time may be from when the auxiliary member 70 comes into contact with the paper until a predetermined number of pulses are given to the drive motor of the conveying roller 63.

  In 720, the control unit 310 determines whether or not the value M is smaller than the total number N of sheets included in the sheet bundle. The value M is a reference value (threshold value) set as a predetermined number, and is an integer of 2 or more. If the value M is smaller than the total number N of sheets contained in the sheet bundle (Yes in 720), the value q is substituted into the variable m in 725. The value q is an integer less than or equal to the value M. The value q may be calculated based on the value M, for example, as half of the value M or 1/3 of the value M. If the value M is not smaller than the total number N of sheets included in the sheet bundle (No in 720), the value r is substituted into the variable m in 730. The value r is an integer smaller than the value q.

  In 708, the control unit 310 determines whether the sheet is a sheet that is m sheets or more before the last sheet of the sheet bundle. If the sheet is m or more sheets before the last sheet in the sheet bundle (Yes in 708), a value j is substituted into a variable i in 709. The value j is an integer of 1 or more. On the other hand, if the sheet is not m sheets before the last sheet in the sheet bundle (No in 708), the value k is substituted into the variable i in 710. The value k is an integer greater than or equal to 2 greater than j. The value k may be set in advance. The value k may be set by the user.

  Each of the value M, the value r, and the value q may be set in advance. The value M, the value r, and the value q may be set by the user.

  For example, if the value M is 0, the control unit 310 does not perform the operation 730. The value q is 0 because it is less than or equal to the value M. In 708, the control unit 310 determines whether or not the sheet is a sheet 0 or more sheets before the last sheet of the sheet bundle (that is, the last sheet).

  For example, if the value M is 2, the value q is 2, and the value r is 0, the variable m is set to the variable m in 725 when the total number N of sheets included in the sheet bundle is 2 or less (N = 2, 1). Substitute the value 0 as the value r. In 708, the control unit 310 determines whether or not the sheet is a sheet 0 or more sheets before the last sheet of the sheet bundle (that is, the last sheet). When the total number N of sheets included in the sheet bundle is not 2 or less (N = 3, 4, 5,...), A value 2 as a value q is substituted into a variable m in 730. In step 708, the control unit 310 determines whether the sheet is a sheet two or more sheets before the last sheet in the sheet bundle. If the total number N of sheets included in the sheet bundle is 3, the three sheets are laterally aligned k times each time the sheets are placed on the stacker 91. If the total number N of sheets included in the sheet bundle is 4, the horizontal alignment is performed j times when the first sheet is loaded on the stacker 91, and k each time the remaining three sheets are loaded on the stacker 91. Align horizontally.

  At 711, the alignment member 102 begins to move from the first position to the second position to laterally align the paper. That is, a pulse is started to be given to the motor M2.

  In 712, the control unit 310 confirms whether or not the auxiliary member 70 is in contact with the sheet. If the auxiliary member 70 is in contact with the paper, the control unit 310 causes the auxiliary member 70 to be separated from the paper in 713 after a predetermined time has elapsed after starting to give a pulse to the motor M2 at 711. In the present embodiment, the auxiliary member 70 may be separated from the sheet after the alignment member 102 starts to move in 711 until it reaches the second position. While the auxiliary member 70 is separated from the sheet, the alignment member 102 performs horizontal alignment. That is, this predetermined time may be shorter than the time from when the alignment member 102 starts to move until it arrives at the second position. Note that the arrival of the alignment member 102 at the second position and the separation of the auxiliary member 70 from the sheet may be simultaneous. The auxiliary member 70 may be separated from the paper later than the alignment member 102 arrives at the second position.

  After lateral alignment, the controller 310 begins to move the alignment member 102 from the second position to the third position at 714.

  In 715, the control unit 310 subtracts 1 from the variable i. In 716, it is confirmed whether or not the variable i is 0. If the variable i is not 0 (No in 716), the process returns to 711 to perform horizontal alignment again.

  If the variable i is 0 (Yes in 716), the control unit 310 determines in 717 whether the subsequent sheet is the last sheet in the sheet bundle. If the subsequent sheet is not the last sheet in the sheet bundle (No in 717), the process returns to 703. The alignment member 102 stops at the third position. On the other hand, if the subsequent sheet is the last sheet in the sheet bundle in 717 (Yes in 717), the stapler 110 binds the sheet bundle and the folding mechanism 120 folds the sheet bundle in 718. The sheet bundle is discharged to the sheet bundle stacking tray 500.

  After the binding and folding, at 719, the control unit 310 confirms whether or not the number of sheets bundled in the operation key 7 has been folded before the start key is pressed. If the control unit 310 determines that all the input sheet bundles have been folded (No in 719), the process returns to 702. The alignment member 102 does not stop at the third position and moves further to the first position at 702.

  On the other hand, when the control unit 310 determines that all the input sheet bundles have been folded (Yes in 719), the control unit 310 ends the operation in the stacking unit 80. Judgment as to whether or not the input number of sheets has been folded is not limited to after binding and folding. After the start key is pressed on the operation key 7, the binding and folding to the final bundle are completed. It is good also to carry out before.

  The trigger of the operation of each part is not limited to the fall of the output of the carry-out roller sensor 65. For example, the rise of the output of the carry-out roller sensor 65 may be a trigger. The trigger may be that the auxiliary member 70 is brought into contact with or separated from the paper. The output of the sheet lower end detection means 99 may be a trigger. The control unit 310 may have a timer that measures the time for generating the trigger. The temporal relationship between the start of operation of each unit and the trigger may be set in advance by calculation, experiment, or the like for each sheet size and stored in the storage unit of the control unit 310.

  The standby position of the stacker 91 is different for each paper size designated by the image forming apparatus 1. Accordingly, the time from when the auxiliary member 70 is brought into contact with the paper from 706 to 713 until it is released may be set according to the paper size.

  If the first sheet is unloaded to the stacking unit 80, the conveying speed may be reduced after the unloading roller sensor 65 detects the trailing edge of the sheet at 704 in FIG. For example, the first sheet of the sheet bundle is carried out to the stack tray 82 where the sheets are not yet placed. The friction between the stack tray 82 and the paper is small. If the conveyance speed of the first sheet is reduced, it is possible to prevent the sheet unloaded from the unloading roller 64 from jumping too much above the stack tray 82. For the second and subsequent sheets, the sheet is placed on the stack tray 82, and the friction between the sheet and the sheet is large, so the conveyance speed does not have to be reduced.

The number of horizontal alignments may increase as the number of sheets increases. For example, when the last two sheets are placed on the stacker 91, the lateral alignment may be performed twice, and when the final sheet is placed on the stacker 91, the lateral alignment may be performed three times.

  In this way, by performing the horizontal alignment a plurality of times in a state where the last sheet is stacked, all the sheets are surely aligned a plurality of times. After the lateral alignment of the final sheet is finished, binding and folding are performed. Even if the last sheet is subjected to the horizontal alignment a plurality of times, it is not necessary for the image forming apparatus 1 to wait for paper discharge. For example, by performing the horizontal alignment twice only in a state where the last sheet is stacked, the influence of the delay can be minimized and the sheet bundle can be appropriately aligned.

  When a sheet other than the final sheet is placed on the stacker 91, the sheets may be aligned a plurality of times. The number of horizontal alignments (second number) to the final sheet stacked on the stacker 91 is larger than the number of horizontal alignments (first number) performed on the sheets stacked on the stacker 91 before the final sheet. do it.

  The second position may be changed depending on the number of horizontal alignments. For example, if k = 3 and 711 to 716 are executed, the distance between the alignment member 102a and the alignment member 102b is the second distance at the second position when i = 3, and the first distance when i = 2. The distance between the alignment member 102a and the alignment member 102b at the position 2 is a fourth distance that is larger than the second distance and narrower than the third distance. When i = 1, the distance is aligned with the alignment member 102a at the second position. The distance from the member 102b may be a fifth distance that is narrower than the second distance.

  For example, if k = 3 and 711 to 716 are executed, the distance between the alignment member 102a and the alignment member 102b is the fourth distance at the second position when i = 3, and the first distance when i = 2. The distance between the alignment member 102a and the alignment member 102b at the position 2 is the fifth distance, and when i = 1, the distance between the alignment member 102a and the alignment member 102b is the second distance at the second position. It is good.

[Modification of lateral alignment operation]
In 708, the control unit 310 may determine whether the sheet is the mth sheet or less from the last sheet in the sheet bundle, and may set the value M and the value q to 1 or more. Alternatively, the value M may be 2 or more.
For example, if the value M is 2, the value q is 2, and the value r is 0, the variable m is set to the variable m in 725 when the total number N of sheets included in the sheet bundle is 2 or less (N = 2, 1). Substitute the value 0 as the value r. In step 708, the control unit 310 determines whether the sheet is a sheet equal to or smaller than the zeroth sheet counted from the last sheet of the sheet bundle. Since the zero or less sheets counted from the last sheet of the sheet bundle are sheets after the last sheet, the control unit 310 determines in 708 whether or not it is any sheet. When the total number N of sheets included in the sheet bundle is not 2 or less (N = 3, 4, 5,...), A value 2 as a value q is substituted into a variable m in 730. In 708, the control unit 310 determines whether the sheet is a second sheet or less from the last sheet of the sheet bundle. When the total number N of sheets included in the sheet bundle is 3, when the first sheet is placed on the stacker 91, the paper is aligned j times, and each time the remaining two sheets are placed on the stacker 91, k Align horizontally. If the total number N of sheets included in the sheet bundle is 4, the horizontal alignment is performed j times when the first sheet is placed on the stacker 91 and when the second sheet is placed on the stacker 91, respectively. Each time the remaining two sheets are placed on the stacker 91, they are horizontally aligned k times.
When the number of sheets included in the sheet bundle is small and the sheet bundle is easy to arrange, if the value m is larger than the total number of sheet bundles, the time for lateral alignment is saved.

[Embodiment 1 of auxiliary member and pressing member]
The auxiliary member 70 and the pressing member 130 will be described. FIG. 9 is a cross-sectional view of the auxiliary member 70 and the pressing member 130. FIG. 10 is a perspective view of the auxiliary member 70 and the pressing member 130.

  A stack of sheets stacked on the stacker 91 in a standing position may be bent due to its own weight or rotation of the assist roller 73. Hereinafter, the alignment in the sheet conveyance direction in which the original binding position of the sheet is shifted to the lower side of the stacking unit 80 due to the deflection is referred to as vertical alignment.

  The auxiliary member 70 includes a holding member 130 that holds the paper so as not to bend.

  The auxiliary member 70 includes a shaft 71, an arm 72, and an assist roller 73. The shaft 71 has a protrusion 74.

  The pressing member 130 includes a paddle 132 and an attachment member 134. The paddle 132 abuts on the lower end of the paper placed on the stacker 91. The paddle 132 is connected to the mounting member 134. The shaft 71 supports the attachment member 134. The attachment member 134 rotates around the shaft 71. The attachment member 134 has a slot into which the shaft 71 is inserted. A spring (elastic member) 138 such as a winding spring or a spring biases the paddle 132 toward the stack tray 82.

  The attachment member 134 has a first end surface 136a that contacts the protrusion 74 at one end of the arc of the slot. The attachment member 134 has a second end face 136b at the other end of the arc of the slot. The distance between the first end 136 a and the second end 136 b is shorter than the diameter of the shaft 71. The first end portion 136a and the second end portion 136b are sufficiently separated so as not to contact the protrusion 74 at the same time. The protrusion 74 is fixed to the shaft 71. The protrusion 74 moves between the first end surface 136a and the second end surface 136b. Since the pressing member 130 is biased by the spring 138, the first end surface 136 a contacts the protrusion 74 when the paddle 132 is not in contact with the sheet. The protrusion 74 does not contact the first end 136a and the second end 136b at the same time.

  Operations of the auxiliary member 70 and the pressing member 130 will be described. FIG. 11A to FIG. 11D are cross-sectional views of the auxiliary member 70 and the pressing member 130.

  As shown in FIG. 11A, the auxiliary member 70 is located at a position away from the stack tray 82 or the sheet (standby position of the auxiliary member 70). The pressing member 130 is biased toward the stack tray 82 by a spring 138. The pressing member 130 is at the stop position when the first end portion 136 a contacts the protrusion 74. The stop position may be a position where the lower end of one sheet conveyed to the stack tray 82 is pressed against the stack tray 82. The stop position may be a position where the stack tray 82 and the pressing member 72 intersect on a plane whose normal is the axial direction of the shaft 71.

  As shown in FIG. 11B, the auxiliary member 70 rotates from the standby position in order to bring the assist roller 73 into contact with the paper P <b> 1 conveyed to the stack tray 82.

  As the auxiliary member 70 rotates, the protrusion 74 pushes the first end 136a. The pressing member 130 rotates around the shaft 71 in a direction away from the stack tray 82. The pressing member 130 moves in conjunction with the rotation of the auxiliary member 70 to a position where it does not interfere with the paper P <b> 1 stacked on the stack tray 82.

  After the paper P1 is stacked on the stack tray 82, as shown in FIG. 11C, the auxiliary member 70 rotates in a direction away from the stack tray 82 and the paper P1 to return to the standby position.

  On the other hand, the pressing member 130 urged by the spring 138 presses the lower end of the paper P1 against the stack tray 82 in order to eliminate the deflection of the paper P1.

  As shown in FIG. 11D, the auxiliary member 70 rotates from the standby position in order to bring the assist roller 73 into contact with the paper P <b> 2 conveyed to the stack tray 82. The assist roller 73 rotates in contact with the paper P2.

  When the auxiliary member 70 rotates from the standby position in order to bring the assist roller 73 into contact with the paper P2, the lower end of the paper P2 only needs to be below the position where the assist roller 73 comes into contact with the paper P2.

  As the auxiliary member 70 rotates, the protrusion 74 pushes the first end 136a. The pressing member 130 rotates around the shaft 71 in a direction away from the stack tray 82. The pressing member 130 moves in conjunction with the rotation of the auxiliary member 70 to a position where it does not interfere with the paper P2 stacked on the stack tray 82. The auxiliary member 70 and the pressing member 130 repeat the operations shown in FIGS. 13A to 13D until all sheets of the sheet bundle are stacked on the stack unit 90.

  The auxiliary member 70 and the pressing member 130 at the time of binding and folding will be described. FIG. 12 is a cross-sectional view of the auxiliary member 70 and the pressing member 130 when binding the sheet bundle. FIGS. 13A and 13B are cross-sectional views of the auxiliary member 70 and the pressing member 130 when the sheet bundle is folded.

  As shown in FIG. 12, the auxiliary member 70 rotates to the standby position so as to be separated from all the sheets of the sheet bundle stacked on the stack unit 90. The pressing member 130 contacts the lower end of the uppermost sheet PN of the sheet bundle P in order to press the sheet bundle P against the stack tray 82. The stapler 110 binds the sheet bundle P in a state where the deflection of the sheet bundle P is eliminated. When the sheet bundle P is thick, the pressing member 130 comes into contact with the sheet bundle P and stops without rotating to the stop position. On the other hand, since the auxiliary member 70 rotates to the standby position, the protrusion 74 and the first end 136a are in a separated state. Even if the pressing member 70 stops without rotating to the stop position, the auxiliary member 70 can rotate to the standby position.

  After the stapler head 112 and the anvil 114 have bound the sheet bundle P, the auxiliary member 70 waits for the assist roller 73 to contact the sheet bundle P conveyed to the stack tray 82, as shown in FIG. Rotate from position. The stack unit 90 moves so that the binding position of the sheet bundle P is at a position where the folding mechanism 120 positioned below the stapler 110 is folded. The stack unit 90 moves downward along the stack tray 82 as indicated by an arrow E. The sheet bundle P moves downward as the stack unit 90 moves. The assist roller 73 abuts on the sheet bundle P while rotating to assist the lowering of the sheet bundle P as the stack unit 90 descends.

  When the binding position of the sheet bundle P comes to the position where the folding mechanism 120 is folded, the auxiliary member 70 is separated from the stack tray 82 and the sheet bundle P in order to return to the standby position, as shown in FIG. Rotate in the direction. On the other hand, the pressing member 130 is closer to the tip of the paddle 132 than the position where the sheet bundle P is in contact with the lower end of the sheet bundle P when the stapler 110 is bound to press the sheet bundle P against the stack tray 82. To contact the lower end of the sheet bundle P. The folding plate 122 and the folding roller pair 124 of the folding mechanism 120 fold the sheet bundle P from which the deflection is eliminated.

  In this way, even when the stack of sheets stacked in the standing position is bent by its own weight or due to the rotation of the assist roller 73 of the auxiliary member 70, the deflection is eliminated by the pressing member 130. can do. Accordingly, since the sheet bundle is bound or folded without being bent, it is possible to perform processing in a state in which the alignment in the vertical direction is maintained. Further, since the pressing member 130 holds the sheets each time the sheets are stacked, the possibility that all the stacked sheet bundles are bent can be reduced, and the deflection can be easily eliminated.

[Embodiment 2 of auxiliary member and pressing member]
FIG. 14 is a cross-sectional view of the stopper 140, the auxiliary member 70, and the pressing member 130. FIG. 15 is a view of FIG. 14 viewed from the direction of arrow F.

  The stopper 140 is bridged between the first stacker 91a and the second stacker 91b in the width direction of the conveyed paper. The stopper 140 is located near the stack tray 82 at the bottom of the stacker 91. The stopper 140 prevents the pressing member 130 that presses the lower end of the paper P1 against the stack tray 82 from rotating too much. If the pressing member 130 is rotated too much, the paddle 132 may bend the paper P1 to the opposite side or cause wrinkles at the lower end of the paper P1.

  Since the stopper 140 prevents the pressing member 130 from rotating too much, the auxiliary member 70 can rotate in a direction away from the stack tray 82 from the standby position that balances with the stop position.

  The stopper 140 is not limited to a configuration that spans between the first stacker 91a and the second stacker 91b. For example, it may be a protrusion attached to either the stacker 91a or the stacker 91b. Alternatively, instead of the stopper 140, the stack tray 82 may be long enough to prevent the pressing member 130 from rotating more than necessary.

[Embodiment 3 of auxiliary member and pressing member]
FIG. 16 is a cross-sectional view showing a flexible member such as rubber or plastic as the paddle 132. The stack tray 82 instructs the sheet bundle P. The auxiliary member 70 is separated from the stack tray 82.

  In this embodiment, when the sheet bundle P is stacked on the stack tray 82 and the auxiliary member 70 is separated from the stack tray 82, the pressing member 130 biased by the spring 138 is stacked on the stack tray 82. The lower end of the top sheet PN of the sheet bundle P is pressed against the stack tray 82.

  The paddle 132 having flexibility warps against the paper P1, and comes into contact with the PN stacked on the top of the paper bundle P over a wide area. The paddle 132 is deformed as the pressing member 130 rotates after contacting the sheet bundle P. The direction of the force applied from the paddle 132 to the lower end of the sheet bundle P gradually becomes perpendicular to the stack tray 82 as the pressing member 130 rotates after contacting the sheet bundle P. The force with which the paddle 132 pushes up the lower end of the sheet bundle P is reduced.

[Embodiment 4 of auxiliary member and pressing member]
The paddle 132 shown in FIG. 17 has a flexible first paddle 132a and a second paddle 132b connected to the tip of the first paddle 132a. The lower end of the second paddle 132b is fixed to the first paddle 132a. The other upper end of the second paddle 132b can be brought into contact with and separated from the first paddle 132a. The second paddle 132b may be a flexible member or may not be a flexible member. As shown in FIG. 18, the center of the second paddle 132b may be fixed to the tip of the first paddle 132a.

  The paddle 132 shown in FIG. 17 and FIG. 18 can hold the sheet bundle from a direction near the vertical direction with respect to the stack tray 82. Therefore, the paddle 132 shown in FIGS. 17 and 18 can eliminate the deflection without lifting the sheet bundle P.

[Embodiment 5 of the auxiliary member and the pressing member]
In the present embodiment, another example of the auxiliary member 70 and the pressing member 130 will be described. FIG. 19 is a cross-sectional view of the auxiliary member 70 and the pressing member 130. FIG. 20 is a perspective view of the auxiliary member 70 and the pressing member 130.

  The auxiliary member 70 includes a shaft 71, an arm 72, and an assist roller 73. The shaft 71 supports the stopper 75. The pressing member 130 includes a paddle 132 and an attachment member 134.

  The attachment member 134 of the pressing member 130 has a protrusion 134a. When the protrusion 134 a comes into contact with the stopper 75, the rotation of the pressing member 130 biased by the elastic force of the spring 138 is stopped.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

1 is a schematic diagram of an image forming apparatus. Schematic of a paper post-processing apparatus. FIG. 3 is a schematic block diagram of a control system of the image forming apparatus and the sheet post-processing apparatus. Schematic for demonstrating a stack part. The schematic seen from the arrow A direction of FIG. 4 for demonstrating a horizontal alignment member. Schematic for demonstrating operation | movement of a horizontal alignment member. The flowchart for demonstrating operation | movement of a horizontal alignment member. The timing chart of each member corresponding to the flowchart of FIG. Schematic for demonstrating an auxiliary member and a pressing member. The schematic perspective view for demonstrating the auxiliary member and pressing member of FIG. Schematic for demonstrating operation | movement of an auxiliary member and a pressing member. Schematic for demonstrating the auxiliary member and pressing member at the time of binding a sheet bundle. Schematic for demonstrating the auxiliary member and pressing member at the time of folding a paper bundle. Schematic for demonstrating a stopper. The schematic seen from the arrow F direction of FIG. 14 for demonstrating a stopper. Schematic for demonstrating another example of an auxiliary member and a pressing member. Schematic for demonstrating another example of an auxiliary member and a pressing member. Schematic for demonstrating another example of an auxiliary member and a pressing member. Schematic for demonstrating another example of an auxiliary member and a pressing member. The schematic perspective view for demonstrating the auxiliary member and pressing member of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image reading part 3 Image forming part 70 Auxiliary member 80 Stacking part 82 Stack tray 100 Horizontal alignment member 102 Alignment member 130 Holding member 310 Control part

Claims (8)

An accumulating member that supports the sheets conveyed one by one in an upright position;
A receiving member for receiving the lower end of the paper supported by the storage member;
An auxiliary member that contacts the paper that has been rotated and conveyed from the predetermined position toward the storage member and assists the storage of the paper in the storage means;
When the auxiliary member rotates following the rotation of the auxiliary member via the mounting portion, and the auxiliary member rotates toward the storage member and contacts the paper supported by the storage member, A pressing member that is spaced apart from the lower end and that contacts the lower end of the sheet and presses it toward the accumulation member when the auxiliary member rotates to the predetermined position and moves away from the sheet supported by the accumulation member; ;
A paper stacking device comprising:   The sheet stacking apparatus according to claim 1, further comprising an elastic member that urges the pressing member toward the storage member.   The mounting portion rotates the auxiliary member to the predetermined position when the pressing member abuts against the paper on the storage member before the auxiliary member rotates to the predetermined position. The paper stacking apparatus according to claim 2, wherein the pressing member is held without being driven.   3. The sheet stacking apparatus according to claim 2, wherein the pressing member includes a flexible paddle that comes into contact with a lower end of a sheet supported by the accumulation member, and the attachment portion that attaches the paddle to the auxiliary member. .   The pressing member is provided on a first paddle having flexibility to be attached to the auxiliary member via the attachment portion, and a tip side of the first paddle, and an end portion on the attachment portion side is the first paddle. 3. The sheet stacking apparatus according to claim 2, further comprising a second paddle that can contact with and separate from one paddle and abuts against a lower end of the sheet supported by the storage member. A binding member for binding the bundle of sheets stored in the storage member;
The sheet stacking device according to claim 1, wherein when the binding member binds the sheet bundle, the auxiliary member is separated from the sheet bundle, and the pressing member abuts and presses against a lower end of the sheet bundle.   2. The sheet stacking apparatus according to claim 1, wherein when the receiving member supporting the sheet bundle moves, the auxiliary member is separated from the sheet bundle, and the pressing member abuts and presses against a lower end of the sheet bundle. .   The sheet stacking device according to claim 2, further comprising a stop member that stops the rotation of the pressing member toward the storage member side on the storage member side.

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