JP3900964B2 - Paper post-processing apparatus and image forming system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a post-sheet processing for performing a Z-folding process, a binding process, and the like on a sheet on which an image is recorded by an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile, and a multifunction machine having these functions. It relates to the device.
[0002]
[Prior art]
In recent years, post-processing devices that enable file binding by performing punching, bi-folding, and Z-folding on image recording paper on which an image is formed by an image forming apparatus such as a copying machine, a printer, or a multi-function machine. Is provided.
[0003]
2. Description of the Related Art Conventionally, as paper storage devices that store paper discharged from an image forming apparatus in a tray and perform binding processing, Japanese Patent Application Laid-Open Nos. 59-43765, 60-183461, and 60-248563 are disclosed. Those described in each publication are known.
[0004]
Also, as a device for Z-folding a sheet, Japanese Utility Model Laid-Open No. 62-68973 and Japanese Patent Laid-Open No. 4-64577 are known.
[0005]
Japanese Patent Laid-Open No. 2001-261220 is disclosed as a sheet post-processing apparatus that executes a binding process on a sheet discharged from an image forming apparatus after a Z-folding process.
[0006]
[Problems to be solved by the invention]
The paper post-processing apparatus that performs the conventional Z-folding process and binding process has the following problems.
[0007]
In the conventional sheet post-processing apparatus, sheets discharged from the image forming apparatus are stacked on the sheet mounting table to be aligned, and are discharged after being bound. In order to align the sheets sent on the sheet mounting table, for example, the one described in Japanese Patent Application Laid-Open No. 59-43765 adopts a method of rotating an impeller-like paddle wheel in one direction. ing.
[0008]
However, in this method, the sheet fed from the transport roller onto the sheet mounting table reaches the paddle wheel while sliding down on the inclined sheet mounting table in a free state, so that skew is likely to occur, and reliable. It has the problem that it cannot be matched.
[0009]
In particular, in a sheet post-processing apparatus that performs alignment processing by placing sheets ejected from the image forming apparatus on a sheet mounting table after Z-folding processing and aligning them, the overlapping surface of the Z-folded sheets When a plurality of Z-folded sheets are stacked, the bulges between the sheets increase, and the slanted sheet bends, bends, or bends, causing a problem that reliable alignment cannot be performed. . The occurrence of the bending of the paper becomes more conspicuous as the paper mounting table is inclined more steeply.
[0010]
In addition, when the Z-folded paper is transported on the paper mounting table after being bound and is held and discharged by the paper discharge roller, the paper of the bundle of papers stacked on the paper mounting table is processed. If the overlapping surface is swollen, the leading end of the sheet bundle in the discharge direction varies, and it is difficult for the sheet to be pinched by the rotating discharge roller, resulting in discharge failure.
[0011]
[Means for Solving the Problems]
The above problems are solved by the sheet post-processing apparatus and the image forming system of the present invention.
[0013]
( 1 In the paper post-processing apparatus that performs the binding process by placing the paper discharged from the image forming apparatus on the paper placement table after the Z-folding process, and aligning the sheets, the blowing unit disposed above the paper placement table And control means for controlling the air blowing of the air blowing means. The control means starts air blowing when the first Z-folded paper is conveyed to the paper placing table, and performs binding processing. When the sheet that has been Z-folded later is discharged from the sheet mounting table, the air blowing is stopped. Along with the number of the Z-folded sheets that are sequentially placed on the sheet placing table, the amount of air blown by the blowing unit is changed. A sheet post-processing apparatus.
[0014]
( 2 ) Image formation Part , An image forming apparatus including a sheet conveying unit, a first post-processing apparatus that performs Z-folding processing on a sheet discharged from the image forming apparatus, and a Z-folding process that is placed on the sheet mounting table for alignment and binding. (1) comprising the blower means for discharging after the processing and the second post-processing device having the control means. ) An image forming system comprising: the sheet post-processing device described above.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, a sheet post-processing apparatus (hereinafter referred to as a post-processing apparatus) and an image forming apparatus including the post-processing apparatus according to the present invention will be described with reference to the drawings.
[0016]
[Image forming system]
FIG. 1 is an overall configuration diagram of an image forming system including an image forming apparatus A, a first post-processing apparatus B, and a second post-processing apparatus C.
[0017]
[Image forming apparatus]
The image forming apparatus A includes a charging unit 2, an image exposure unit (writing unit) 3, a developing unit 4, a transfer unit 5A, a charge removing unit 5B, a separation claw 5C, and a cleaning unit 5D around the rotating image carrier 1. The image forming unit has an arranged image forming unit, and after the surface of the image carrier 1 is uniformly charged by the charging unit 2, exposure scanning based on image data read from the document is performed by the laser beam of the image exposure unit 3. A latent image is formed, and the latent image is reversely developed by the developing unit 4 to form a toner image on the surface of the image carrier 1.
[0018]
On the other hand, an image recording sheet (hereinafter referred to as a sheet) S fed from the sheet feeding unit 6A is sent to the transfer position via the intermediate sheet feeding unit 6B. The toner image is transferred onto the paper S by the transfer means 5A at the transfer position. Thereafter, the charge on the back surface of the sheet S is erased by the charge eliminating unit 5B, separated from the image carrier 1 by the separation claw 5C, conveyed by the conveying unit 7A, and subsequently heated and fixed by the fixing unit 8, and then by the sheet discharge roller 7C. Discharged.
[0019]
When image formation is performed on both sides of the sheet S, the sheet S heated and fixed by the fixing unit 8 is branched from the normal sheet discharge path by the conveyance path switching plate 7B, and is switched back by the reverse conveyance unit 7D. After being reversed, the sheet is discharged out of the apparatus by the sheet discharge roller 7C. The paper S discharged from the paper discharge roller 7C is sent to the inlet 10 of the first post-processing device B.
[0020]
On the other hand, the developer remaining on the surface of the image carrier 1 after the image processing is removed downstream of the separation claw 5C by the cleaning unit 5D to prepare for the next image formation.
[0021]
On the upper front side of the image forming apparatus A, an operation unit 9 for selecting and setting an image forming mode and a sheet post-processing mode is disposed.
[0022]
On the upper part of the image forming apparatus A, an image reading apparatus D provided with an automatic document feeder of a document moving type reading system is installed.
[0023]
[Paper post-processing device]
The sheet S carried into the first post-processing apparatus B is selected and processed by selecting at least one process such as a punching process, a Z-folding process, a middle folding process, and a tri-folding process, which will be described later. Is sent to. The first post-processing apparatus B and the second post-processing apparatus C are collectively referred to as a sheet post-processing apparatus.
[0024]
The first post-processing apparatus B includes an inlet portion 10, first punching means 20, first folding means 30, and paper discharge means 40.
[0025]
The paper S that has been punched and Z-folded in the first post-processing apparatus B or the paper S that has passed through the post-processing without being post-processed is discharged from the paper discharge means 40 and arranged adjacently. It is carried into the inlet 50 of the second post-processing apparatus C.
[0026]
The second post-processing apparatus C includes a first sheet feeding unit 51, a second sheet feeding unit 52, a second punching unit 60, a stacking unit 70, a binding unit (stapling unit) 700, a second folding unit 80, and a shift unit. 67, a paper discharge unit 90, a lift paper discharge tray 92, an upper paper discharge tray 93, a lower paper discharge tray 94, and the like are arranged.
[0027]
[First post-processing apparatus]
FIG. 2 is a plan view of the sheet S before the Z-folding process and the sheet S after the Z-folding process. FIG. 2A is a plan view of the paper S before the Z-folding process. C indicated by a broken line is a first fold, and d is a second fold. FIG. 2B is a plan view of the sheet S that has been Z-folded.
[0028]
A first crease c and a second crease d are formed on the sheet S that has been Z-folded by the first post-processing device B, and is folded into a Z-shape.
[0029]
Next, the configuration of the first post-processing apparatus B will be described.
FIG. 3 is a cross-sectional view showing the configuration of the first post-processing apparatus B and the paper conveyance path.
[0030]
The paper S discharged from the paper discharge roller 7C of the image forming apparatus A is introduced into the inlet 10 of the first post-processing apparatus B. An inlet guide plate 11 is swingably supported by the post-processing apparatus main body at the inlet portion 10 forming the paper entry portion.
[0031]
An inlet part sensor PS1 for detecting the passage of the leading edge and the trailing edge of the paper S is arranged on the downstream side of the inlet part 10 in the paper conveying direction, and the first punching means 20 is arranged on the downstream side thereof. Yes.
[0032]
A pair of registration rollers 31 </ b> A and 31 </ b> B are provided on the downstream side of the first punching unit 20 in the sheet conveyance direction. Further, a pair of intermediate transport rollers 33A and 33B and a switching member 34 for switching the transport direction are provided in the first transport path (1) formed by the pair of guide plates 32. The switching member 34 is swung by the solenoid SD1.
[0033]
A pair of first folding rollers 35A and 35B that are in pressure contact with each other are provided on the downstream side of the first conveyance path (1). Further, a second folding roller 35C that is in pressure contact with the first folding roller 35B is provided. The surfaces of the first folding rollers 35A and 35B and the second folding roller 35C are made of a material having a high frictional resistance such as rubber.
[0034]
On the downstream side of the first folding rollers 35A and 35B in the transport direction, a second transport path (2) is formed by a pair of guide plates 36 provided on both sides in the thickness direction of the paper S. A first stopping means (first position regulating means) 37 is arranged in the vicinity of the downstream side of the second conveying path (2) in the conveying direction.
[0035]
The first stopping means 37 has an abutting portion 37D that protrudes from a part of an endless belt 37C that can be rotated by winding a driving pulley 37A and a driven pulley 37B.
[0036]
The abutting portion 37D is driven by the stepping motor M1, and moves to a position selected from a plurality of predetermined positions according to the size of the paper S to be processed in the paper transport direction and the selection of the folding processing mode, and stops.
[0037]
By providing the abutting portions 37D at two positions in the sheet width direction orthogonal to the sheet conveying direction, the leading end of the sheet S is held at a right angle to the traveling direction, and the sheet S is abutted correctly. Yes.
[0038]
A first paper folding processing section is formed by the first folding rollers 35A and 35B, the guide plate 36, the first stopping means 37, and the stepping motor M1.
[0039]
Further, on the downstream side in the transport direction of the first folding rollers 35A and 35B, a third transport path (3) is formed by guide plates 38 provided on both sides in the thickness direction of the paper.
[0040]
On the other hand, similarly to the first stop means 37, there is a second stop means (second position restricting means) 39 for stopping the third conveying path {circle around (3)} by bringing the first fold c of the paper S into contact with the leading edge. It is provided so as to be movable in the paper transport direction. The second stop means 39 includes a drive pulley 39A, a driven pulley 39B, an endless belt 39C, an abutting portion 39D, and a stepping motor M2.
[0041]
In addition, a pair of guide plates 351 are provided on the downstream side of the sandwiching position of the second folding roller 35C and the driven roller 35D, and the fourth conveying path 4 has a function of discharging the sheet S after the folding process by the guide plates 351. ▼ is formed. The downstream side of the fourth transport path {circle around (4)} joins the third transport path {circle around (3)} and continues to the second stop means 39 and the paper discharge means 40. The paper discharge means 40 includes a paper discharge path 41 and a pair of paper discharge rollers 42A and 42B.
[0042]
PS2 is a paper passage sensor that detects the passage of the leading edge of the paper S passing through the third transport path (3). PS3 is a paper discharge sensor for paper discharge detection disposed in the vicinity of the paper discharge rollers 42A and 42B.
[0043]
The operation of the first post-processing apparatus B configured as described above, that is, post-processing that performs simple sheet passing, sheet folding, sheet Z folding, and sheet tri-folding will be described.
[0044]
・ Simple paper
The switching member 34 provided in the first post-processing apparatus B is rotated counterclockwise by the solenoid SD1. The sheet S is conveyed from the inlet 10 by the registration rollers 31A and 31B, guided to the sheet discharge path 41 of the sheet discharge means 40 by the switching member 34, and sandwiched between the sheet discharge rollers 42A and 42B, and the second post-processing apparatus C. It is conveyed to.
[0045]
When punching a sheet having a short length in the transport direction, for example, a sheet S of A4 size or less, the sheet S introduced into the entrance 10 is predetermined by registration rollers 31A and 31B and sheet discharge rollers 42A and 42B. When the length is transported, the paper is temporarily stopped, and the first punching means 20 perforates the paper S at a predetermined position. Send it in.
[0046]
When punching in the vicinity of the rear edge of a sheet having a long length in the transport direction, for example, a sheet S of A4R or B4 size or larger, first, the switching member 34 is swung by the solenoid SD1, and the first folding roller 35A The movable guide member 350 supported so as to be swingable in the vicinity is swung counterclockwise by the solenoid SD2 so as to block the second transport path (2).
[0047]
After such a conveyance path is formed, the sheet S is conveyed by the registration rollers 31A and 31B. First, the sheet S is transported to the first transport path (1), transported by the intermediate transport rollers 33A and 33B, guided by the movable guide member 350, and further rotated by the rotation of the first folding rollers 35A and 35B in the direction of the arrow. Then, the first folding rollers 35A and 35B enter the clamping position. In the mode in which the punching process is performed at the rear end of the sheet, the stepping motor M2 is operated to move the second stop means 39 and retract from the third transport path (3).
[0048]
The first folding rollers 35A, 35B, registration rollers 31A, 31B, and intermediate conveyance rollers at the timing when the trailing edge of the sheet S conveyed through the third conveyance path (3) and the paper discharge path 41 reaches the first punching means 20. After 33A and 33B are stopped and the first punching means 20 is operated to punch the paper S at a predetermined position, the rollers S are simultaneously rotated again to transport the paper S, and the paper discharge rollers 42A and 42B 2 is sent to the post-processing apparatus C.
[0049]
・ Z-fold processing
FIG. 4 is a cross-sectional view showing the transport path of the paper S to be Z-folded.
[0050]
FIG. 4A shows a process of forming the first crease c. The leading edge of the sheet S that has passed through the first conveyance path {circle around (1)} and entered the second conveyance path {circle around (2)} is abutted against the abutting portion 37D of the first stop means 37 and stops. The sheet S is continuously conveyed by the intermediate conveyance rollers 33A and 33B, so that the intermediate portion is bent, and the sheet S is inserted into the nipping position N1 of the first folding rollers 35A and 35B to be provided with the first crease c. (See FIG. 2 (b)).
[0051]
FIG. 4B shows a process of forming the second fold line d. The sheet S folded and conveyed by the first folding rollers 35A and 35B travels along the third conveyance path (3) with the first fold c as the leading edge, and stops against the abutting portion 39D of the second stopping means 39. To do. The sheet S is continuously conveyed by the first folding rollers 35A and 35B, so that the intermediate portion is bent and bent, and is wound around the holding position N2 between the first folding roller 35B and the second folding roller 35C. A second crease d is added and Z-folding is performed (see FIG. 2B).
[0052]
FIG. 4C shows a process of discharging the paper S after the Z-folding process is completed. After the Z-folding process is completed, the second stopping means 39 is driven, and the abutting portion 39D is retracted from the downstream conveyance path of the third conveyance path (3). The Z-folded sheet S passes through the sheet discharge path 41, is sandwiched between the sheet discharge rollers 42A and 42B, and is discharged out of the apparatus.
[0053]
[Second post-processing apparatus]
FIG. 5 is a cross-sectional view showing the transport path of the paper S in the second post-processing apparatus C.
[0054]
In the second post-processing apparatus C, a first paper feed unit 51, a second paper feed unit 52, and an upper paper discharge tray 93 are arranged in the upper stage of the drawing, and a second punching means 60, a shift means 67, a discharge means are arranged in the middle stage. The paper section 90 is arranged in series on the same plane that is substantially horizontal, and the stacking section 70 and the second folding means 80 are arranged in series on the same plane that forms an inclined surface in the lower stage.
[0055]
In addition, on the left side of the second post-processing apparatus C in the drawing, a lifting / discharging tray 92 on which the shifted sheet S and the edge-bound sheet bundle Sa are stacked, and the three-folded sheet S or middle A lower discharge tray 94 on which the folded sheet bundle Sa is stacked is arranged.
[0056]
・ Inlet
Into the entrance 50 of the second post-processing device C, the paper S that has been simply discharged in the first post-processing device B or the paper S that has been subjected to either punching or folding processing is introduced. The In addition, the entrance 50 includes a slip sheet (intersheet) J for partitioning a bundle of sheets supplied from the first sheet feeding unit 51 installed on the second post-processing apparatus C, and a second sheet feeding unit. The cover sheet K supplied from 52 is introduced. In the vicinity of the inlet portion 10, an inlet portion sensor PS4 that detects the passage of the leading edge of the paper S is disposed.
[0057]
・ Paper feed
The slip sheet J accommodated in the sheet feeding tray of the first sheet feeding unit 51 is separated and fed by the sheet feeding roller 511, sandwiched between the conveying rollers 512, 513, and 514 and introduced into the inlet unit 50. . Further, the cover sheet K accommodated in the sheet feeding tray of the second sheet feeding unit 52 is separated and fed by the sheet feeding roller 521, sandwiched between the conveying rollers 513 and 514, and introduced into the inlet unit 50. .
[0058]
・ Second drilling means
A second punching unit 60 is disposed downstream of the inlet unit 50 in the sheet conveyance direction. A registration roller 65 is arranged on the upstream side in the paper conveyance direction of the punching position by the second punching means 60, and a conveyance roller 66 is arranged on the downstream side in the paper conveyance direction of the punching position.
[0059]
・ Paper branching means
On the downstream side of the second punching means 60 in the paper conveyance direction, a paper branching means comprising switching gates G1 and G2 is provided. The switching gates G1 and G2 are driven by a solenoid (not shown) in three directions of paper conveyance paths, that is, a first conveyance path F1 reaching the upper sheet discharge tray 93, a second conveyance path F2 reaching the middle sheet discharge section 90, and a lower stack. It is selectively branched to any one of the third transport paths F3 that reach the section 70.
[0060]
・ Simple paper discharge
When this sheet conveyance is set, the switching gate G1 opens only the first conveyance path F1, and blocks the other second conveyance path F2 and the third conveyance path F3.
[0061]
The sheet S passing through the first conveyance path F1 is sandwiched and raised by the conveyance roller 931, is discharged by the discharge roller 932, is placed on the upper discharge tray 93, and is sequentially stacked. When the punching process is performed on the paper S, the second punching unit 60 is activated. A maximum of about 200 sheets S can be stacked on the upper discharge tray 93.
[0062]
・ Shift processing
When this transport mode is set, the switching gate G1 is retracted upward, and the switching gate G2 blocks the third transport path F3 and opens the second transport path F2 to allow the sheet S to pass. The sheet S passes between the switching gates G1 and G2.
[0063]
The paper S discharged from the first post-processing device B, the slip sheet J fed from the first paper feed unit 51, or the cover paper K fed from the second paper feed unit 52 is switched. After passing through the intermediate sheet passing path of the gates G1 and G2, the shift unit 67 performs a shift process in a direction orthogonal to the sheet conveyance direction.
[0064]
The shift means 67 performs a shift process for changing the paper discharge position of the paper S in the transport width direction every predetermined number of sheets. The shifted sheet S is discharged to a lift discharge tray 92 outside the apparatus by a pair of discharge rollers 91 of the discharge section 90 and is sequentially placed. The elevating / discharging tray 92 is configured to sequentially descend when discharging a large number of sheets S, and can accommodate a maximum of about 3000 sheets (A4 size, B5 size) of sheets S. .
[0065]
・ End binding processing
FIG. 6A is a plan view showing a state in which the binding needles SP are hit at two locations near the side edge of the sheet bundle Sa by the two sets of binding means 700, and FIG. It is a top view which shows the state which stapled the binding needle SP in the corner part of Sa.
[0066]
When the binding process or the folding process is set in the operation unit 9 of the image forming apparatus A, the image forming process is performed in the image forming apparatus A, and the entrance of the second post-processing apparatus C through the first post-processing apparatus B. The sheet S sent to the section 50 passes through the second punching means 60, is sent to the third transport path F3 below the switching gate G2, is sandwiched by the transport rollers 701 and 704, is transported, and the leading edge of the paper S The section comes into contact with the vicinity of the nipping position of the entrance conveyance roller pair (registration roller) 705 and is stopped, and the leading edge of the sheet is aligned (see FIG. 5).
[0067]
After the trailing end of the sheet S in the advancing direction is discharged from the nipping position of the transport roller 704, the sheet S turns down due to its own weight, descends on the inclined surface of the sheet placing table (intermediate stacker) 71, and the entrainment belt The leading end of the sheet is slid and conveyed by 706, and the trailing end of the sheet S comes into contact with the sheet abutting surface of the end binding position regulating means (hereinafter referred to as an end binding stopper) 72 provided in the vicinity of the binding means 700. And stop.
[0068]
Reference numeral 73 denotes a pair of width alignment members that are movably provided on both side surfaces of the paper placing table 71. When a predetermined number of sheets S are stacked and aligned on the sheet placing table 71, the binding unit 700 performs a binding process, and the sheets S are bound.
[0069]
The bundled sheet bundle Sa is held at the rear end portion of the sheet S by the discharge claw 74A of the discharge belt 74, is slid up on the mounting surface of the sheet mounting table 71, and is pushed upward obliquely. The sheet S sandwiched between the sheets 91 is discharged and stacked on the elevating / discharging tray 92.
[0070]
・ Saddle stitching
FIG. 6C is a plan view showing a state in which the binding needles SP are struck at two central positions of the sheet bundle Sa by the two sets of binding means 700.
[0071]
When the saddle stitching middle folding mode is set, the end binding stopper 72 in the vicinity of the binding processing position (binding position of the binding needle) of the binding means 700 is retracted from the conveyance path. At substantially the same time, the saddle stitching / folding combined position restricting means 75 downstream thereof moves in the direction of the extending surface of the sheet passing path and stops at a predetermined position corresponding to the size of the sheet S (length in the transport direction) (FIG. 5).
[0072]
After the final sheet S is positioned and placed on the sheet placing table 71, the saddle stitching process is performed by the binding unit 700 on the sheet bundle Sa including the cover sheet K and all the pages of the sheet S. By this saddle stitching process, the binding needle SP is driven into the central portion in the transport direction of the sheet bundle Sa.
[0073]
・ Folding process
FIG. 6D is a perspective view of the sheet bundle Sa that has been subjected to the folding process after the saddle stitching process.
[0074]
The folding plate 82 connected to the drive source projects in the left direction in the drawing from the sheet placement surface of the guide plate 81 in response to the half-folding processing start signal. The front end portion of the folding plate 82 that protrudes straightly in the left direction shown in the figure pushes in the central portion of the sheet bundle Sa, and pushes and separates the holding position N3 of the first folding rollers 83 and 84 via the sheet bundle Sa. (See FIG. 5).
[0075]
After the leading end of the folding plate 82 has passed the clamping position N3 of the first folding rollers 83 and 84, the folding plate 82 is retracted, and the central portion of the sheet bundle Sa is pinched by the first folding rollers 83 and 84. A crease g is formed. The fold line g substantially coincides with the driving position of the binding needle SP on the sheet bundle Sa by the saddle stitching process.
[0076]
The sheet bundle Sa that has been pinched and formed with the fold line g is unloaded by the first folding rollers 83 and 84 that are driven to rotate, and is placed on the lower sheet discharge tray 94 outside the apparatus (see FIG. 5).
[0077]
・ Z-fold processing
FIG. 7 is a perspective view showing a state in which the binding needles SP are hit at two locations near the side edge of the sheet bundle Sa by the two sets of binding means 700 after the Z-folding process.
[0078]
[Blower means]
FIG. 8 is a cross-sectional view of the stacking unit 70 and the paper discharge unit 90. FIG. 9 is a cross-sectional view of the stacking unit 70 showing a state in which the sheet S that has been subjected to the Z-folding process is stored.
[0079]
A blower unit 76 is disposed above the sheet placing table 71. The air blowing means 76 includes a fan motor 761 and a holding frame body 762 that holds the fan motor 761. The fan motor 761 has a central portion in the width direction perpendicular to the transport direction of the Z-folded paper S and the vicinity of the center of the transport direction length of the Z-folded paper S placed on the paper placement table 71. It is arranged near the part. For example, when the A3 size paper S is Z-folded, the length of the paper S in the transport direction is 210 mm, and the center position of the fan motor 761 is from the stop position of the end binding stopper 72 to the paper transport path. It is installed about 105 mm diagonally above.
[0080]
The sheet S having a shape in which the overlapping surface is expanded by the Z-folding process is sandwiched and conveyed by the pair of entrance conveyance rollers 705, discharged to the space above the sheet placement table 71, and slid on the inclined surface of the sheet placement table 71. Then, it descends and comes into contact with the end binding stopper 72 and stops.
[0081]
The Z-folded paper S that moves on the inclined surface of the paper mounting table 71 is pressed in the lower half-folded portion by the upper overlapping portion shown in the figure, and the paper S becomes a buckled buckled state. May occur. In addition, when a plurality of Z-folded sheets S are stacked, the bulges between the sheets increase, and the inclined sheet S bends, bends, bends, and cannot be reliably aligned. Arise. The occurrence of the bending of the paper S becomes more conspicuous as the paper placement table 71 is inclined more steeply.
[0082]
Further, when the sheet S that has been subjected to the Z-folding process is conveyed on the sheet placing table 71 after being bound, and is sandwiched and ejected by the sheet discharge roller, the sheet S that has been bound on the sheet placing table 71 is stacked. If the sheet overlapping surface of the bundle Sa is swollen, the leading end of the sheet bundle Sa in the discharge direction varies, and is difficult to be pinched by the rotating discharge roller pair 91, resulting in a discharge failure.
[0083]
The air blowing means 76 of the present invention operates the fan motor 761 when the Z-folded sheet S is placed on the inclined surface of the sheet placing table 71, and the rear surface of the Z-folded sheet S is moved. By pressing the sheet S on the sheet placing table 71 with a blast flow (the white arrow in the figure), the Z-folded sheet S is flattened and smoothly lowered on the sheet placing table 71 to be surely attached to the end binding stopper 72. Can be reached.
[0084]
When the edge-bound sheet bundle Sa is held by the discharge claw 74A of the rotating discharge belt 74 and is carried out to the paper discharge unit 90, the air flow caused by the operation of the fan motor 761 (the white arrow shown in the figure) ), The rear surface of the Z-folded paper S is pressed against the paper placement table 71 by a blow air flow, so that the Z-folded paper S is flattened and smoothly conveyed on the paper placement table 71 and discharged. The roller pair 91 can be reliably reached.
[0085]
・ Jam processing
One end portion 763 of the holding frame body 762 of the air blowing means 76 is supported on a support shaft 771 fixed to the support member 77 so as to be swingable. The support member 77 is fixed to a guide plate 707 disposed on the upstream side of the pair of entrance transport rollers 705 in the paper transport direction. The holding frame body 762 is urged by a spring 78 that winds the support shaft 771, and is swung toward the sheet conveyance path side above the sheet placing table 71.
[0086]
The other end portion 764 of the holding frame body 762 has an extended tongue shape, and comes into contact with and separates from the distal end portion 79 </ b> A of the fixing member 79 fixed to the sheet placing table 71. The holding frame body 762 urged by the spring 78 is positioned in contact with the distal end portion 79 </ b> A of the fixing member 79.
[0087]
When the paper S is poorly transported in the paper transport path above the paper mounting table 71 and the paper S is taken out, the end portion 764 of the holding frame body 762 is gripped, and the air blowing means 76 is one point shown in FIG. The paper conveyance path is opened by swinging in the direction of the chain line.
[0088]
・ Control of air blowing means
FIG. 10 is a timing chart of air blowing control by the fan motor 761 of the air blowing means 76.
[0089]
The control means changes the amount of air blown by the air blowing means 76 in accordance with the number of Z-folded sheets S that are sequentially placed on the paper placement table 71. For example, it is possible to switch to a two-speed transmission of low speed blow of 0.9 to 1.25 m / min and high speed blow of 1.25 to 3 m / min.
[0090]
In other words, the control means drives the fan motor 761 to start low-speed air blowing after a predetermined time t1 has elapsed since the paper passage sensor PS5 detects the passage of the rear end of the first Z-folded paper S. To do.
[0091]
After a predetermined time t2 has elapsed since the passage of the rear end of the third sheet S is detected by the sheet passage sensor PS5, the fan motor 761 is switched to high-speed air blowing.
[0092]
After a predetermined time t3 has elapsed since the passage of the rear end of the final sheet S, for example, the fifth sheet S, is detected by the sheet passage sensor PS5, the binding unit 700 is driven to bind the aligned sheet bundle Sa to the binding needle SP. Hit the needle.
[0093]
After the end of the stitching by the binding means 700, the air blow by the fan motor 761 is stopped after a predetermined time t4 has elapsed. During the elapse of the predetermined time t4, the bound sheet bundle Sa that has been subjected to the Z-folding process is discharged from the sheet placing table 71.
[0094]
In this way, the paper S that has been Z-folded is transported, aligned, and bound in the stacking unit 70, discharged from the paper discharge unit 90, and placed on the lift paper discharge tray 92.
[0095]
In the post-processing apparatus of the present invention, the image forming system including the image forming apparatus A, the first post-processing apparatus B, and the second post-processing apparatus C has been described. However, the first processing apparatus is connected to the image forming apparatus A. The present invention can also be applied to the post-processing apparatus B, the second post-processing apparatus C connected to the image forming apparatus A, or the single first post-processing apparatus B or the second post-processing apparatus C. It is.
[0096]
【The invention's effect】
As described above, the sheet post-processing apparatus of the present invention provides the following effects.
[0097]
(1) When a sheet that has been Z-folded and whose overlapping surface is expanded is placed on the inclined surface of the sheet placing table, and a plurality of Z-folded sheets are stacked, Corresponding to the number of the Z-folded sheets sequentially placed on the sheet placing table, the sheet surface is pressed by a blowing flow in which the blowing amount by the blowing unit is changed. As a result, the sheet on the inclined surface is prevented from being bent and bent or bent, so that reliable sheet conveyance and alignment are achieved.
[0098]
(2) When the sheet that has been Z-folded and the overlapping surface is swollen is conveyed on the sheet placing table after the binding process, and is nipped and discharged by the sheet discharge roller, Is pressed to reduce the variation of the leading edge of the sheet bundle rising on the inclined surface and flattened, so that the leading edge of the sheet bundle is securely held by the rotating paper discharge roller and discharged. , Paper discharge defects are eliminated.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an image forming system including an image forming apparatus, a first post-processing apparatus, and a second post-processing apparatus.
FIG. 2 is a plan view of a sheet before post-processing such as folding processing and a sheet after post-processing.
FIG. 3 is a cross-sectional view showing a configuration of a first post-processing apparatus and a paper conveyance path.
FIG. 4 is a cross-sectional view illustrating a conveyance path of a sheet to be Z-folded.
FIG. 5 is a cross-sectional view illustrating a sheet conveyance path in a second post-processing apparatus.
FIG. 6 is a plan view showing a state in which binding needles are hit at two locations near the side edge of the sheet bundle, a plan view showing a state in which binding needles are hit at the corners of the sheet bundle, and binding at two central positions of the sheet bundle. The top view which shows the state which struck a needle | hook, The perspective view of the sheet | seat bundle which carried out the middle folding process after the saddle stitch process.
FIG. 7 is a perspective view showing a state in which binding needles are hit at two locations near the side edge of the sheet bundle after the Z-folding process.
FIG. 8 is a cross-sectional view of a stacking unit and a paper discharge unit.
FIG. 9 is a cross-sectional view of the stacking unit illustrating a state in which a sheet that has been Z-folded is stored.
FIG. 10 is a timing chart of air blowing control by a fan motor of the air blowing means.
[Explanation of symbols]
70 Stacking unit
71 Paper loading table (intermediate stacker)
72 Edge-binding position restricting means (edge-binding stopper)
74 Discharge belt
76 Blower means
761 Fan motor
762 Holding frame
77 Support member
771 spindle
78 Spring
79 Fixing member
90 Output section
91 discharge roller pair
92 Lifting / discharging tray
A Image forming apparatus
B First aftertreatment device
C Second aftertreatment device

Claims (5)

In a sheet post-processing apparatus that performs alignment processing by placing and aligning sheets discharged from the image forming apparatus on a sheet mounting table after Z-folding processing,
An air blowing means disposed above the paper mounting table, and a control means for controlling the air blowing of the air blowing means,
The control unit starts air blowing when the first Z-folded sheet is conveyed to the sheet placing table, and the Z-folded sheet is discharged from the sheet placing table after the binding process. And an air flow amount by the air blowing means are changed in accordance with the number of the Z-folded paper sheets that are sequentially placed on the paper placement table. . When the Z-folded paper is placed on the paper placement table, the air blowing means is operated to push the back surface of the Z-folded paper onto the paper placement table by air blowing. The sheet post-processing apparatus according to claim 1, wherein the sheets are aligned. The paper post-processing apparatus according to claim 1, wherein the air blowing unit is swingably supported and can open and close a paper conveyance path above the paper placement table. The blower means includes a central portion in the width direction perpendicular to the transport direction of the Z-folded paper and the vicinity of the center of the length of the Z-folded paper that is placed on the paper placement table. The sheet post-processing apparatus according to claim 1, wherein the sheet post-processing apparatus is disposed in the vicinity of the section. An image forming apparatus comprising an image forming unit and a sheet conveying unit;
A first post-processing device that Z-folds the paper discharged from the image forming device;
5. The apparatus according to claim 1, further comprising: a second post-processing device having the blowing unit and the control unit for discharging after the Z-folding process is performed after the Z-folding process is performed on the sheet mounting table, aligned, and bound. A sheet post-processing apparatus according to claim 1;
An image forming system comprising:

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