JP4554244B2 - Paper processing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet processing apparatus that performs processing such as alignment, binding, and punching on sheets, and an image forming apparatus that includes the sheet processing apparatus integrally or separately.

Various types of paper post-processing devices that automatically perform sorting / punching / stapling processing on paper discharged from image forming apparatuses such as copiers and printers have been provided. Sheet post-processing with a single-end binding that binds along the edge, a multi-point binding along the center line that divides the paper into two parts, and a center folding function that folds the central part and then binds Equipment needs are increasing. Therefore, the inventions disclosed in Patent Documents 1-4 have been proposed.
JP-A-8-192951 Japanese Patent Laid-Open No. 10-148983 JP-A-10-167562 JP 2000-21805 A

  In general, when stapling is performed on a matched sheet bundle, the stapler is operated by positioning the sheet bundle. As a means for positioning the sheet bundle, there are a method of stopping the sheet bundle being conveyed at a predetermined timing, a position where the sheet bundle is abutted at a predetermined position to align the end of the sheet, and the abutting means is moved for positioning. Conceivable. In the prior art, the latter method aims to increase the accuracy of the binding position and the folding position.

  However, in the prior art, when the shape of the abutting means varies or the abutting means varies, the binding position and the folding position vary for each apparatus. Furthermore, depending on how the abutting means is attached, the abutting means bends due to the weight of the paper, and there is a problem that the binding position and the folding position vary depending on the paper size and type even in the same apparatus.

  For this reason, control for detecting the edge of the sheet and performing the binding operation has been devised, but the behavior of the sheet bundle differs depending on the conveyance direction of the sheet bundle up to the binding, and the backlash of the driving unit of the bundle moving means is affected. The binding position could not be stabilized.

  In other words, when performing saddle stitching, the saddle stitching position of the sheet bundle is accurately transported to the binding position of the saddle stitching stapler by shortening the transport distance of the sheet bundle from the detection position to the saddle stitching position regardless of the minimum size or maximum size. In the case where the sheet bundle is forward / reversely conveyed from the detection position according to the size, it is difficult to stop at the target position due to the influence of the backlash of the drive system when the sheet bundle is reversely conveyed.

  The present invention has been made in view of the above points, and an object of the present invention is to increase the accuracy of the saddle stitching position with a simple configuration so that the binding position varies even in a plurality of apparatuses as well as in the same apparatus. The purpose is to enable high quality paper processing.

In order to achieve the above object, the first means includes: a conveying means that conveys paper; and a sheet processing apparatus that performs a predetermined process on the sheet bundle conveyed by the conveying means. A control unit that determines a binding position at the time of the saddle stitching process based on information from the detection unit that detects the edge of the sheet bundle and performs the binding process. The sheet bundle to be conveyed is conveyed by a preset amount more than the binding position, and is then moved in the reverse direction for saddle stitching.
The second means is characterized in that, in the first means, the preset amount is set within a distance from a reference fence to the detection means.
A third means is characterized in that, in the first or second means, the saddle stitching process is performed by a staple processing tray that temporarily stores and aligns sheets.
The fourth means is characterized in that, in the third means, the detection means is arranged on the staple processing tray.
The fifth means is characterized in that, in the fourth means, the detection means has a paper presence / absence detection function in the staple processing tray.
The sixth means is characterized in that the image forming apparatus is provided with the sheet processing apparatus according to any one of the first to fifth means as a single body or as a separate body.

  According to the present invention, since the sheets are aligned in the same direction, the saddle stitching position is highly accurate with a simple configuration, and the binding position varies even in a plurality of apparatuses as well as in the same apparatus. Can not be.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
<Overall configuration>
FIG. 1 is a diagram illustrating a system configuration of an image forming system including a sheet post-processing apparatus and an image forming apparatus as a sheet processing apparatus according to an embodiment of the present invention. In FIG. Part of the device is shown.

In FIG. 1, the sheet post-processing apparatus PD is attached to the side of the image forming apparatus PR.
The paper (recording medium) discharged from the image forming apparatus PR is guided to the paper post-processing device PD. The sheet passes through a conveyance path A having post-processing means (in this embodiment, a punch unit 100 as a punching means) for post-processing one sheet, and then to the conveyance path B and the shift tray 202 which are led to the upper tray 201. The branching claw 15 and the branching claw 16 are configured to be distributed to a conveyance path C that leads to a conveyance path D that leads to a conveyance path C that leads to a processing tray F that performs alignment and stapling (hereinafter also referred to as a staple processing tray). The tray surface 66 on which the sheets of the staple processing tray F are stacked is inclined so that the downstream side in the conveyance direction of the sheets discharged from the staple discharge roller 11 described later is upward, and the inclination angle is in the direction of gravity. On the other hand, the angle is set to a minimum angle that does not interfere with a later-described middle folding plate 74 on the lower side of the inclined surface and its driving mechanism and a mechanism such as the end surface binding stapler S1.

The paper guided to the staple processing tray F through the transport paths A and D and aligned and stapled by the staple processing tray is transported to the shift tray 202 by the branch guide plate 54 and the movable guide 55 which are deflecting means. The sheet is configured to be distributed to a path C, a processing tray G that performs folding or the like (hereinafter also referred to as a middle folding processing tray). Led to. Further, a branching claw 17 is disposed in the conveyance path D, and is held in the state shown in the figure by a low load spring (not shown). After the paper trailing edge passes through this, the conveyance rollers 9, 10 and the staple discharge roller 11 by reversing at least the conveying roller 9 to guide the trailing edge of the paper to the paper storage E to retain the paper,
It is configured such that it can be conveyed while being superimposed on the next sheet. By repeating this operation, it is possible to convey two or more sheets in a superimposed manner.

In the conveyance path A common to the upstream of the conveyance path B, the conveyance path C, and the conveyance path D, an inlet sensor 301 that detects a sheet received from the image forming apparatus, an inlet roller 1, a punch unit 100, and a punch downstream thereof. Waste hopper 101, conveying roller 2, branch claw 15 and branch claw 16
Are arranged sequentially. The branch claw 15 and the branch claw 16 are held in the state shown in FIG. 1 by a spring (not shown), and when the solenoid (not shown) is turned on, the branch claw 15 rotates upward and the branch claw 16 rotates downward. The paper is distributed to the conveyance path B, the conveyance path C, and the conveyance path D.

When guiding the paper to the conveyance path B, the branching claw 15 is in the state of FIG. 1 and the solenoid is OFF. When guiding the paper to the conveyance path C, the branching claw 15 is turned on by turning on the solenoid from the state of FIG. When the paper is guided to the transport path D, the branch claw 16 is in the state of FIG. 1, the solenoid is OFF, and the branch claw 15 is in the state of FIG. By turning on the solenoid, the solenoid is turned upward.

In this paper post-processing apparatus, punching (punching unit 100), paper alignment + edge binding (jogger fence 53, edge binding stapler S1), paper alignment + saddle stitching (jogger fence 53, saddle stitching stapler) for the paper. S2), paper sorting (shift tray 202),
Each process such as the middle folding (folding plate 74, folding rollers 81 and 82) can be performed.

  In this embodiment, the image forming apparatus PR performs optical writing on an image forming medium such as a photosensitive drum based on the input image data to form a latent image on the surface of the photosensitive drum, and the formed latent image is displayed. This is an image forming apparatus using a so-called electrophotographic process in which toner is developed, transferred to a recording medium such as paper, fixed, and discharged, and the image forming apparatus using the electrophotographic process itself is well known, so the details here Description and illustration of this configuration are omitted. In this embodiment, an image forming apparatus using an electrophotographic process is illustrated. However, a system using a known image forming apparatus such as an inkjet or a printing machine and a printing machine (printer) may also be used. Needless to say.

<Staple processing tray>
The configuration of the processing tray F that performs sheet alignment and stapling will be described.
FIG. 2 is a perspective view of a main part showing the configuration of the processing tray F that performs sheet alignment and stapling processing. In the drawing, the sheets guided to the processing tray F by the staple discharge roller 11 are sequentially stacked on the tray surface 66. In this case, each sheet of paper is tapped with a roller 12 in the vertical direction (paper transport direction).
The jogger fence 53 performs alignment in the horizontal direction (paper width direction orthogonal to the paper transport direction). Thereafter, the end-face stitching stapler S1 is driven by a stapling signal from the control means 350 between job breaks, that is, between the last sheet of the sheet bundle and the first sheet of the next sheet bundle, and the binding process is performed. The sheet bundle subjected to the binding process is immediately sent to the shift paper discharge roller 6 by the discharge belt 52 having the discharge claw 52a, and is discharged to the shift tray 202 set at the receiving position.

As shown in FIG. 3, the home position of the discharge claw 52a is detected by the discharge belt HP sensor 311, and the discharge belt HP sensor 311 is connected to the discharge belt 5a.
2 is turned on and off by the discharge claw 52a provided in the second. Two discharge claws 52a are arranged at opposing positions on the outer periphery of the discharge belt 52, and the sheet bundle accommodated in the processing tray F is moved and conveyed alternately. Further, if necessary, the discharge belt 52 is reversely rotated, and the sheet bundle accommodated in the processing tray F on the back surface of the discharge claw 52a 'opposite to the discharge claw 52a waiting to move the sheet bundle. The tips in the transport direction may be aligned.

As shown in FIG. 4, the discharge belt 52 driven by the discharge motor 157 has a discharge belt 52 and its drive pulley arranged at the center of alignment in the paper width direction and symmetrically with the discharge roller 56. The peripheral speed of the discharge roller 56 is set to be faster than the peripheral speed of the discharge belt 52.

As shown in FIG. 2, the hitting roller 12 is given a pendulum motion by the hitting SOL 170 about the fulcrum 12 a and intermittently acts on the sheet fed to the processing tray F to hit the sheet against the rear end fence 51. The hitting roller 12 rotates counterclockwise. The jogger fence 53 is driven via a timing belt by a jogger motor 158 capable of forward and reverse rotation, and reciprocates in the paper width direction.

The end-face stitching stapler S1 is driven via a timing belt by a forward / reversely movable stapler moving motor (not shown), and moves in the sheet width direction in order to bind a predetermined position of the sheet edge. A stapler movement HP sensor for detecting the home position of the end face binding stapler S1 is provided at one end of the moving range, and the binding position in the paper width direction is controlled by the amount of movement of the end face binding stapler S1 from the home position. The

As shown in FIGS. 1, 4 and 11, the saddle stitching stapler S2 has a distance from the rear end fence 51 to the needle striking position of the saddle stitching stapler S2 that is half the conveyance direction length of the maximum sheet size capable of saddle stitching. Two are arranged so as to be equal to or more than the corresponding distance, and two are arranged symmetrically with respect to the alignment center in the paper width direction and are fixed to the stay 63. Further, the saddle stitching stapler S2 includes a needle portion and is divided into two units of a stitcher (driver) unit S21 for driving out the needle and a clincher unit S22 for bending the needle, and the stitcher unit S21 conveys the processing tray F. It is arranged on the road D side. In the figure, reference numeral 64a denotes a front side plate, 64b denotes a rear side plate, and reference numeral 310 denotes a paper presence / absence sensor that detects the presence / absence of paper on the staple processing tray F.

The sheet bundle that has undergone saddle stitching in the staple processing tray F is folded in the middle of the sheet. This middle folding is performed in the middle folding processing tray G. For this purpose, it is necessary to transport the bound sheet bundle to the middle folding processing tray G. In this embodiment, a sheet bundle deflecting unit is provided on the most downstream side in the conveyance direction of the staple processing tray F, and conveys the sheet bundle to the middle folding processing tray G side.

The sheet bundle deflection mechanism includes the staple processing tray F and the center folding processing tray G shown in FIGS.
As shown in the enlarged view of the part, it consists of a branch guide plate 54 and a movable guide 55. As shown in the operation explanatory diagrams of FIGS. 5 to 7, the branch guide plate 54 is provided so as to be swingable in the vertical direction around a fulcrum 54 a, and a rotatable pressure roller 57 is provided on the downstream side of the branch guide plate 54. The pressure is applied to the discharge roller 56 side. The position of the branch guide plate 54 is set at the bundle branch drive motor 16.
1 is defined by the contact position with the cam surface 61a of the cam 61 rotating by obtaining a driving force from 1.

The movable guide 55 is swingably supported on the rotation shaft of the discharge roller 56, and is linked to one end of the movable guide 55 (the end opposite to the branch guide plate 54) by a connecting portion 60a. An arm 60 is provided. The link arm 60 is composed of a shaft fixed to the front plate 64a shown in FIG. 3 and a long hole portion 60b, whereby the swing range of the movable guide 55 is restricted.

Further, it is held at the position shown in FIG. Further, when the link arm 60 is pushed by the cam surface 61b of the cam 61 that rotates by obtaining drive from the bundle branching drive motor 161, the connected movable guide 55 rotates upward. The bundle branching guide HP sensor 315 detects the shield 61c of the cam 61 and detects the home position of the cam 61. Accordingly, the cam 61 controls the stop position by counting the drive pulses of the bundle branching drive motor 161 with the home position as a reference.

FIG. 5 shows the branch guide plate 54 and the movable guide 5 when the cam 61 is located at the home position.
5 is an operation explanatory diagram showing the positional relationship of FIG. The guide surface 55 a of the movable guide 55 has a function of guiding the paper in the path to the shift paper discharge roller 6.

In FIG. 6, as the cam 61 rotates, the branch guide plate 54 rotates counterclockwise (downward) in the drawing around the fulcrum 54a, and the pressure roller 57 contacts the discharge roller 56 and pressurizes. It is an operation explanatory view showing the state.

In FIG. 7, when the cam 61 further rotates, the movable guide 55 rotates in the clockwise direction (upward) in the figure, and the path leading from the staple processing tray F to the half-fold processing tray G is guided along the branch guide plate 54 and the movable guide. FIG. FIG. 3 shows the positional relationship in the depth direction.

  In this embodiment, the branch guide plate 54 and the movable guide 55 are operated by a single drive motor. However, each drive motor is provided so that the movement timing and stop position can be controlled according to the paper size and the number of sheets to be bound. You may do it.

<Folding processing tray>
8 and 9 are explanatory views of the operation of the moving mechanism of the folding plate 74 for performing the middle folding.
The folding plate 74 has a long hole portion 7 on each of two shafts 64c standing on the front and rear side plates 64a and 64b.
4a is supported by loosely fitting, and further, a shaft portion 74 erected from the folding plate 74
b is loosely fitted in the long hole 76b of the link arm 76, and the link arm 76 swings around the fulcrum 76a, whereby the folding plate 74 reciprocates left and right in FIGS. That is, the shaft portion 75b of the folding plate driving cam 75 is loosely fitted in the long hole portion 76c of the link arm 76, and the link arm 76 swings by the rotational movement of the folding plate driving cam 75.
Accordingly, in FIG. 11, the folding plate 74 reciprocates in a direction perpendicular to the upper bundle conveying guide plates 91 and 92.

The folding plate drive cam 75 is rotated by the folding plate drive motor 166 in the direction of the arrow in FIG. The stopping position is that the half-moon shaped shield 75a is folded at both ends, and the plate HP sensor 32 is folded.
5 is determined by detection.

FIG. 8 shows the home position position completely retracted from the sheet bundle accommodation area of the processing tray G. When the folding plate drive cam 75 is rotated in the direction of the arrow, the folding plate 74 moves in the direction of the arrow and protrudes into the sheet bundle accommodation area of the processing tray G. FIG. 9 shows a position where the center of the sheet bundle of the processing tray G is pushed into the nip of the folding roller 81. When the folding plate drive cam 75 is rotated in the direction of the arrow, the folding plate 74 moves in the direction of the arrow and retracts from the sheet bundle accommodation area of the processing tray G.

  In this embodiment, it is assumed that the sheet folding is performed by folding the sheet bundle. However, the present invention can be applied to the case of folding one sheet. In this case, since only one sheet does not require saddle stitching, when one sheet is discharged, the sheet is fed to the middle folding processing tray G side, folded by the folding plate 74 and the folding roller, and discharged to the lower tray. To do.

<Control device>
As shown in FIG. 11, the control device 350 includes a CPU 360, an I / O interface 37.
Each of the switches on the control panel of the image forming apparatus PR main body, the inlet sensor 301, the upper discharge sensor 302, the shift discharge sensor 3
03, pre-stack sensor 304, staple discharge sensor 305, paper presence sensor 310,
Release belt home position sensor 311, staple movement home position sensor 31
2. Signals from various sensors such as the stapler oblique home position sensor 313, the bundle arrival sensor 321, the movable rear end fence HP sensor 322, and the paper surface detection sensor 330 are input to the CPU 360 via the I / O interface 370.

Based on the input signal, the CPU 360 moves a tray raising / lowering motor for the shift tray 202, a discharge guide plate opening / closing motor for opening / closing the opening / closing guide plate, a shift motor for moving the shift tray 202, and a tapping roller motor for driving the tapping roller 12. , Solenoids such as the hitting SOL 170, a transport motor that drives each transport roller, a paper discharge motor that drives each paper discharge roller, a discharge motor 157 that drives the discharge belt 52, a stapler moving motor that moves the end surface binding stapler S 1, and an end surface Diagonal motor for rotating the binding stapler S1 diagonally, jogger fence 5
3 controls the driving of a jogger motor 158 or the like that moves 3. A pulse signal of a staple transport motor (not shown) that drives the motor staple discharge roller is input to the CPU 360 and counted, and the hitting SOL 170 and the jogger motor 158 are controlled according to this count. Further, the punch unit 100 also controls the CPU 3 by controlling the clutch and the motor.
Execute drilling according to 60 instructions.

The sheet post-processing device PD is controlled by the CPU 360 executing a program written in a ROM (not shown) while using a RAM (not shown) as a work area. In addition, the program data is downloaded from a server via a network or from a recording medium such as a CD-ROM or SD card to a storage medium such as a hard disk device (not shown) via a recording medium driving device instead of or in addition to the ROM. It can also be used after being rolled or upgraded.

<Operation>
Hereinafter, the operation of the sheet post-processing apparatus according to this embodiment executed by the CPU 360 will be described.

In the present embodiment, the non-stipple mode a in which the paper passes through the transport path A and the transport path B and is discharged to the upper tray 201, and the non-stipple mode b in which the paper passes through the transport path A and the transport path C and is discharged to the shift tray 202; Sorting and stacking modes that are discharged to the shift tray 202 through the transport path A, the transport path C, and alignment and binding are performed on the processing tray F through the transport path A and the transport path D, and then discharged to the shift tray 202 through the transport path C. The stapled mode (end stitching mode) and the processing path F are aligned and centrally bound by the processing tray F through the transport path A and the transport path D, and are further folded at the processing tray G and passed through the transport path H to the lower tray 203. Although there is a saddle stitch binding mode to be discharged, here, the end face binding mode and the saddle stitch binding mode will be described.

《End binding mode》
When the end face binding mode is selected, the jogger fence 53 moves from the home position as shown in FIG. 4 and waits at a standby position that is 7 mm away from the width of the paper discharged to the processing tray F. The paper is sorted from the conveyance path A by the branching claw 15 and the branching claw 16, guided to the conveyance path D, and discharged to the processing tray F by the conveyance roller 7, the conveyance roller 9, the conveyance roller 10, and the staple discharge roller 11. At this time, when the paper is conveyed by the staple paper discharge roller 11 and the trailing edge of the paper passes the staple paper discharge sensor 305, the jogger fence 53 is 5 m from the standby position.
m Moves to the inside and stops.

Further, the staple paper discharge sensor 305 detects that when the trailing edge of the paper passes, and the signal is C
Input to the PU 360 (see FIG. 10). The CPU 360 counts the number of pulses transmitted from a staple transport motor (not shown) that drives the staple paper discharge roller 11 from the time of receiving this signal, and hits the SOL 170 after transmitting a predetermined pulse. The tapping roller 12 performs a pendulum motion by turning on / off the tapping SOL 170. When the tapping roller 12 is on, the tapping roller 12 strikes the paper and returns it to the lower side, and abuts against the rear end fence 51 to align the paper.

At this time, every time the paper stored in the processing tray F passes the entrance sensor 101 or the staple paper discharge sensor 305, the signal is input to the CPU 360, and the number of sheets is counted.

After a lapse of a predetermined time after the beating SOL 170 is turned off, the jogger fence 53 is further moved inward by 2.6 mm by the jogger motor 158, temporarily stops, and the horizontal alignment is finished. The jogger fence 53 then moves outward by 7.6 mm, returns to the standby position, and waits for the next sheet. This operation is performed up to the last page. After that, it moves again inward by 7 mm, stops, and prepares for the stapling operation by pressing both ends of the sheet bundle. Thereafter, after a predetermined time, an end face binding stapler S1 is actuated by a staple motor (not shown), and a binding process is performed. At this time, if two or more bindings are designated, the staple moving motor 159 is driven after the binding processing at one place is completed, and the end-face binding stapler S1 is moved to an appropriate position along the rear end of the sheet. The second stitching process is performed. If the third and subsequent locations are specified, this is repeated.

  When the binding process is completed, the discharge motor 157 is driven, and the discharge belt 52 is driven.

At this time, the paper discharge motor is also driven, and the shift paper discharge roller 6 starts to rotate to receive the sheet bundle lifted by the discharge claw 52a, and is discharged to the shift tray 202. At the same time, the state of paper discharge is monitored by a shift paper discharge sensor 303 which is arranged in the vicinity of the shift paper discharge roller 6 and detects paper discharge. The jogger fence 53 is a paper presence sensor 310 or a discharge belt H.
After a predetermined pulse of detection by the P sensor 311, the sheet is retracted 2 mm, and the restriction on the paper by the jogger fence 53 is released. This predetermined pulse is set after the discharge claw 52a comes into contact with the rear end of the paper and passes through the front end of the jogger fence 53.

《Saddle stitch binding mode》
When the saddle stitch binding mode is selected, the paper sorted by the branching pawl 15 and the branching pawl 16 from the transport path A is guided to the transport path D, and the transport roller 7, the transport roller 9, the transport roller 10, and the staple paper discharge. The paper is discharged to the processing tray F by the roller 11. In the processing tray F, the sheets sequentially discharged by the staple discharge roller 11 are aligned in the same manner as in the end face binding mode, and the same operation is performed until just before stapling (see FIG. 12). Thereafter, the sheet bundle is carried to the position shown in FIG. 13 downstream by a predetermined distance set for each sheet size by the discharge claw 52a, and the center thereof is bound by the saddle stitching stapler S2.

Whether the conveyance distance at this time is detected by the paper presence / absence sensor 310 at the rear end of the sheet bundle conveyed by the discharge claw 52a, and is conveyed downstream (the folding processing side is downstream) based on the detection information and the sheet size information. , It is determined whether the sheet is conveyed upstream (the direction opposite to the folding process is the upstream). At this time, the sheet bundle conveyed to the upstream side is conveyed by a predetermined amount for the distance to the binding position, and after the completion of conveyance, a predetermined amount is conveyed again to the downstream side, and the saddle stitching stapler S2 after completion of conveyance is conveyed. Is bound. The predetermined amount at this time is
Distance between rear edge fence 51 and sheet edge detection sensor 310 serving as a reference for the sheet end surface> Upstream transport distance + predetermined amount,
Any value can be used as long as the above holds, but if the amount is large, the productivity decreases, so that is taken into consideration when setting.

  FIG. 10 is a diagram specifically showing this example, and a paper presence / absence sensor (paper end detection sensor) 310 is provided at the rear end (lower end in FIG. 1) of the processing tray F in the paper transport direction. When the paper end detection sensor 310 is provided at this position, in the processing tray F according to this embodiment, the distance between the trailing edge fence 51 serving as the reference of the paper end surface and the saddle stitching position is 250 mm, and the paper presence / absence detection sensor 310 is provided. The distance between the center and the saddle stitching position is 182 mm. The processing procedure for determining the binding position when such a dimensional relationship exists is shown in the flowchart of FIG. A flowchart is shown in FIG.

  In this processing procedure, first, the discharge motor 157 is rotated forward to rotate the discharge belt 52 (step S101). When the discharge belt HP sensor 311 is turned on and the position of the discharge claw 52a can be confirmed (step S102), the discharge claw 52a is moved from the home position to the standby position (step S103) so as not to interfere with the paper. In this state, each time the sheet is discharged to the processing tray F, the jogger fence 53 operates to align the sheets. When the alignment of the sheet bundle is completed (step S104), the discharge motor 157 rotates forward (step S105) and lifts the sheet bundle upward (conveys the sheet bundle downstream in the sheet conveyance direction of the apparatus). When the paper presence / absence sensor 310 is turned on, in other words, when the end of the sheet bundle is detected by the paper presence / absence sensor 310 (step S106), it is determined whether or not the size of the sheet bundle is a size that requires the reverse of the discharge motor 157. A check is made (step S107). That is, in this embodiment, if half the size of the paper in the paper transport direction is larger than the distance between the saddle stitching position and the paper presence sensor 310 (here, 182 mm), the position where the trailing edge of the paper is detected. If it is not moved to the upstream side in the sheet conveyance direction, it cannot be bound at the center of the sheet.

  Therefore, if it is determined in step S107 that the paper size needs to be reversed, a value obtained by adding a predetermined amount to the distance to the binding position is set as a predetermined amount as the amount of reversal of the discharge motor 157 (step S107). In step S108, the discharge motor 157 is reversely rotated by the predetermined amount (steps S109, S110, S111). Then, the predetermined amount is set as a predetermined amount (step S112), the discharge motor 157 is rotated forward (step S113), and when the discharge claw 52a is moved by the predetermined amount (step S114), the discharge motor 157 is stopped (step S115). ), The saddle stitching stapler S2 is turned on to perform saddle stitching (step S116). The predetermined amount here is arbitrarily set as long as it can absorb the backlash of the drive mechanism.

  On the other hand, if the size is not required to be reversed in step S107, that is, if half the size of the paper in the paper transport direction is smaller than the distance between the saddle stitching position and the paper presence sensor 310 (here, 182 mm). The distance from the position where the paper presence sensor 310 is turned on to the binding position is set as a predetermined amount (step S117), the discharge motor 118 is rotated forward (step S118), and the discharge claw 52a is moved to the predetermined amount. (Step S119), the discharge motor 157 is stopped (Step S115), and saddle stitching is executed (Step S116).

  The sheet bundle bound at the position shown in FIG. 13 is transported downstream by a discharge claw 52a for a predetermined distance set for each sheet size, and temporarily stops. This moving distance is managed by the drive pulse of the discharge motor 157.

  Thereafter, as shown in FIG. 14, the leading end of the sheet bundle is sandwiched between the discharge roller 56 and the pressure roller 57, and is guided to the processing tray G formed by turning the branch guide plate 54 and the movable guide 55. Is again conveyed downstream by the discharge claw 52 a and the discharge roller 56. As shown in FIG. 4, the discharge roller 56 is provided on the drive shaft of the discharge belt 52 and is driven in synchronization with the discharge belt 52.

  Then, as shown in FIG. 15, the sheet bundle is moved from the home position to the position corresponding to the sheet size in advance by the upper bundle conveying roller 71 and the lower bundle conveying roller 72 and stopped to guide the lower end face. It is conveyed to the movable rear end fence 73 (FIG. 16). At this time, the folding roller 81 rotates in the direction indicated by the arrow until the leading end of the sheet bundle passes the portion indicated by Q, and the sheet bundle line is smoothly conveyed from the upper bundle conveying guide plate 92 to the lower bundle conveying guide plate 91. To be. Further, the discharge claw 52a stops at the position where another discharge claw 52a ′ arranged at a position facing the outer periphery of the discharge belt 52 reaches the vicinity of the rear end fence 51, and the branch guide plate 54 and the movable guide 55 are Return to the home position and prepare for the next sheet. As shown in FIG. 16, the sheet bundle abutted against the movable rear end fence 73 is released from the pressurization of the lower bundle conveying roller 72. Thereafter, as shown in FIG. 17, the vicinity of the bound needle portion is pushed by the folding plate 74 in a substantially right-angle direction and guided to the nip of the opposing folding roller 81. The folding roller 81 that has been rotated in advance folds the center of the sheet bundle by conveying the sheet bundle under pressure.

  As shown in FIG. 18, the folded sheet bundle is strengthened by the second folding roller 82, and is discharged to the lower tray 203 by the lower discharge roller 83. At this time, when the rear end of the sheet bundle is detected by the folding portion passage sensor 323, the folding plate 74 and the movable rear end fence 73 are returned to the home position, and the pressurization of the lower bundle conveying roller 72 is also returned to the next sheet. Prepare. If the next job is the same sheet size and the same number of sheets, the movable rear end fence 73 may stand by at that position. Reference numeral 324 denotes a lower paper discharge sensor.

  In this embodiment, the second folding roller 82 for enhancing folding is functioning as a folding roller. When the folding is performed, the second folding roller 82 folds the sheet bundle. Folding is performed by passing the nip of the roller 82 a plurality of times (odd times).

As shown in FIG. 5, the end-face stitching stapler S1 is driven through a timing belt by a forward / reversely movable stapler moving motor 159, and moves in the paper width direction in order to bind a predetermined position of the paper edge. A stapler movement HP sensor 312 for detecting the home position of the end face binding stapler S1 is provided at one end of the moving range, and the binding position in the paper width direction is the amount of movement of the end face binding stapler S1 from the home position. Controlled by As shown in FIGS. 1 and 4, the saddle stitching stapler S2 is a distance in which the distance from the rear end fence 51 to the needle striking position of the saddle stitching stapler S2 corresponds to half of the conveyance direction length of the maximum sheet size that can be saddle stitched. Arranged as described above and fixed to the stay 63. (In FIG. 4, the number is two for simplification, but may be three or more.)
As described above, according to the present embodiment, post-conveying binding processing is performed in the same direction as can be seen in the predetermined steps S112 and S113 and steps S117 and S118 for all sizes in which the sheet bundle is moved when binding. Since the bundle conveying and moving means are controlled in this way, the saddle stitching position can be achieved with a simple configuration without being affected by the behavior of the sheet bundle depending on the conveying direction of the sheet bundle or the backlash of the drive system of the sheet bundle moving means. It is possible to prevent variation.

  Further, according to the present embodiment, depending on the paper size to be subjected to the saddle stitching process, when detecting the end of the sheet bundle moved by the moving unit and then moving the moving unit in the reverse direction, A predetermined amount is conveyed (steps S108 to S111), and the predetermined amount is set within the distance of the sheet edge detection sensor from the reference fence, so that it is conveyed more in the reverse direction than the reference fence. The problem that the binding position is shifted is solved, and the saddle stitching position does not vary.

[Second Embodiment]
Since the second embodiment also has the same configuration and basic operation as those of the first embodiment, only differences from the first embodiment will be described.

  The operation in the saddle stitch binding mode will be described below.

  The paper sorted by the branching claw 15 and the branching claw 16 from the conveyance path A is guided to the conveyance path D and discharged to the processing tray F by the conveyance roller 7, the conveyance roller 9, the conveyance roller 10, and the staple paper discharge roller 11. In the processing tray F, the sheets sequentially discharged by the staple discharge roller 11 are aligned in the same manner as in the end-face binding staple mode, and the same operation is performed until just before stapling (see FIG. 12).

Then, the sheet bundle is conveyed to the position (saddle stitching position) in FIG. 13 by the discharge claw 52a which is a conveying means. The transport distance at this time is detected by one of the first to third end surface detection sensors 310a, 310b, and 310c for the front end surface or the rear end surface of the transported sheet bundle. It is set for each paper size.

  For example, when the size in the longitudinal direction of the sheet is not less than LG as shown in FIG. 21, the detection position is set to the leading end of the sheet bundle and the detection sensor is set to 310b in order to reduce the influence of bending due to the weight of the trailing end of the sheet. Yes. Also, when the size in the longitudinal direction of the sheet is equal to or greater than DLT, the detection position is set to the leading end of the sheet bundle and the detection sensor is set to 310c in order to reduce the influence of bending due to its own weight at the trailing end of the sheet. Conversely, when the size in the longitudinal direction of the sheet is A4T or less, the detection position is the rear end of the sheet bundle and the detection sensor is 310a in order to ignore the influence of bending due to its own weight at the rear end of the sheet.

  The end surface detection sensors 310a, 310b, 310c, the rear end fence 51, and the saddle stitching position in this embodiment are in a positional relationship as shown in FIG. 22, and when the sheet bundle is conveyed from the rear end fence 51 to the saddle stitching position. The discharge claw 52a, which is a conveyance means, is set at a position where it can be conveyed only by normal rotation. The positional relationship between the end face detection sensor and the saddle stitching position that can be conveyed only by the normal rotation is the sheet length L, the distance from the rear edge fence 51 to the saddle stitching position S, the rear edge fence 51 to the end face detection sensor. The distance is up to d and the adjustment width of the saddle stitching position (adjustment width by the user) is a, and is determined under the conditions of the following equations (1) and (2).

<When detecting the trailing edge of a stack of paper>
(1) Sda ≧ L / 2
<When detecting the leading edge of a stack of paper>
(2) dsa ≦ L / 2
The first to third end face detection sensors 310a, 310b, and 310c also serve as means for detecting paper presence / absence information in the processing tray F during the initial operation of the apparatus. In this embodiment, the number of rear end detection sensors is set to three. However, when the number is four or more, the paper size can be further subdivided and assigned to each sensor.

  The sheet bundle conveyed to the saddle stitching position is bound by the saddle stitching stapler S2. The sheet bundle bound at the position shown in FIG. 13 is transported downstream by a discharge claw 52a for a predetermined distance set for each sheet size, and temporarily stops. This moving distance is managed by the drive pulse of the discharge motor 157. Thereafter, as shown in FIG. 14, the leading end of the sheet bundle is sandwiched between the discharge roller 56 and the pressure roller 57, and is formed by turning the branch guide plate 54 and the movable guide 55 to be guided to the processing tray G. In order to pass, it is again conveyed downstream by the discharge claw 52a and the discharge roller 56.

  The discharge roller 56 is provided on the drive shaft of the discharge belt 52 and is driven in synchronization with the discharge belt 52. Then, as shown in FIG. 15, the sheet bundle is moved from the home position to a position corresponding to the sheet size in advance by the upper bundle conveying roller 71 and the lower bundle conveying roller 72 and stopped to guide the lower end face. It is conveyed to the movable rear end fence 73. At this time, the discharge claw 52a stops at the position where another discharge claw 52a ′ arranged at a position facing the outer periphery of the discharge belt 52 reaches the vicinity of the rear end fence 51, and the branch guide plate 54 and the movable guide 55 are stopped. Returns to the home position and prepares for the next sheet.

Thereafter, as shown in FIG. 16, the press of the bundle conveying roller lower 72 is released from the sheet bundle abutted against the movable rear end fence 73. Then, as shown in FIG. 17, the vicinity of the bound needle portion is pushed by the folding plate 74 in a substantially right angle direction, and is guided to the nip of the opposing folding roller 81. The folding roller 81 that has been rotated in advance folds the center of the sheet bundle by conveying the sheet bundle under pressure.

  As shown in FIG. 18, the folded sheet bundle is strengthened by the second folding roller 82, and is discharged to the lower tray 203 by the lower discharge roller 83. At this time, when the trailing edge of the sheet bundle is detected by the folding portion passage sensor 323, the folding plate 74 movable trailing edge fence 73 is returned to the home position, and the pressurization of the lower bundle conveying roller 72 is restored to the next sheet. Prepare. If the next job is the same sheet size and the same number of sheets, the movable rear end fence 73 may stand by at that position.

<Operation>
The operation (processing procedure) in the second embodiment is shown in the flowchart of FIG. In this example, as shown in FIG. 22, three end face detection sensors 310a, 310b, and 310c are provided.

  In this process, first, the driving of the discharge motor 157 is started (step S201), and when the discharge claw 52a reaches the rear end position of the sheet bundle (step S202), the suspension motor 157 is stopped (step S203). Next, the jogger fence 53 is operated to align the sheets (step S204), and the discharge motor 157 is driven (step S205).

  Then, it is checked whether or not the paper length is A4T (A4 vertical size) or less (step S206). If the paper length is A4T or smaller (in FIG. 22, A4T, LTT (letter size vertical), B5T) When the end surface detection sensor 301a is turned on (step S207) and the discharge claw 52a is set to a predetermined position for each paper size (step S209), the discharge motor 157 is stopped (step S209) and the saddle stitching process is executed (step S209). S210). When the saddle stitching process is finished, the discharge motor 157 is turned on (step S211), and when the discharge claw 52a reaches a predetermined position, here, the position where the leading end of the sheet bundle is bitten by the sheet bundle deflection mechanism (step S212), The discharge motor 157 is stopped (step S213), and the push-up operation of the good bundle is stopped.

  On the other hand, in the bundle deflection mechanism, a deflection process for deflecting the sheet bundle toward the middle folding processing tray G by the discharge roller 57, the branch guide plate 54, and the movable guide 55 is executed (step S214). Is sent to. Next, the discharge motor 157 is turned on (step S215) and is driven until the discharge claw 52a reaches the home position (steps S216 and S217). Thereafter, the branch guide plate 54 and the movable guide 55 of the bundle deflection mechanism return to the home position (step S218), and prepare for the next processing.

  If the paper length is not A4T or less in step S206, it is further checked whether the paper length is LG (legal size) or more and A3 portrait or less (step S219). When the second end face detection sensor 310b is turned on, the process proceeds to step S208 and subsequent steps, and each process is executed.

  If the sheet length is longer than A3T in step S206 (DLT (double letter size portrait) in FIG. 22), when the third end face detection sensor 310c is turned on, the process proceeds to step S208 and subsequent steps. Execute the process.

  Other parts that are not particularly described are configured in the same manner as the first embodiment and function in the same manner.

  According to this embodiment, there are a plurality of detection means for detecting the end of the sheet bundle to be moved, and the binding process is performed based on information from the detection means set for each paper size among the plurality of detection means. Therefore, even if the paper size is different, the saddle stitching position does not vary.

  Further, according to the present embodiment, the plurality of detecting means for detecting the end portion of the sheet bundle is divided into a detecting means for detecting the leading end portion of the sheet bundle and a detecting means for detecting the trailing end portion, and the sheet size for saddle stitching. If the paper is large size paper (B4T or higher), the leading edge of the sheet bundle is detected, and the binding process is performed based on the detected information, so that the saddle stitching position varies even if the stiffness of the paper is different. There is no.

  In addition, according to the present embodiment, the plurality of end surface detection sensors 310a, 310b, and 310c that detect the sheet bundle end portion have a predetermined interval in the sheet conveyance direction and are aligned in the staple processing tray F. Since the moving means for moving the sheet bundle is arranged at a position where the sheet bundle can be moved to the binding position without operating in the reverse direction, it is affected by the drive system backlash (backlash) of the sheet bundle moving means. It is possible to prevent the saddle stitching position from varying with a simple control configuration.

  Furthermore, according to the present embodiment, the plurality of end surface detection sensors 310a, 310b, and 310c that detect the end portion of the sheet bundle also serve as the paper presence / absence detection unit in the staple processing tray F, so that the saddle stitching can be achieved with minimum cost. A sheet post-processing apparatus with a saddle stitching function can be provided with minimal changes from an apparatus having no function.

1 is a diagram illustrating a system configuration of a sheet post-processing apparatus according to a first embodiment of the present invention. FIG. 5 is a perspective view of a main part showing a configuration of a staple processing tray that performs sheet alignment and stapling processing. FIG. 5 is a perspective view showing a relationship between a staple processing tray and a discharge claw for carrying out paper from the staple processing tray. FIG. 6 is a plan view of a staple processing tray of the sheet post-processing apparatus according to the embodiment of the present invention. It is operation | movement explanatory drawing which shows the positional relationship of a branch guide plate and a movable guide when a cam is located in a home position. It is operation | movement explanatory drawing which shows the state which a branching guide plate rotates centering | focusing on a fulcrum by the rotation of a cam, and the pressurizing roller contacts the discharge roller side and is pressurizing. FIG. 11 is an operation explanatory view showing a state in which a path that guides the movable guide from the staple processing tray to the half-fold processing tray is formed by the branch guide plate and the movable guide by further rotating the cam. FIG. 5 is an operation explanatory view of a folding plate moving mechanism for performing a middle folding, and shows a home position position completely retracted from a sheet bundle accommodation area of a middle folding processing tray. FIG. 6 is an operation explanatory diagram of a folding plate moving mechanism for performing a folding process, and shows a position where the center of a sheet bundle of a folding process tray is pushed into a nip of a folding roller. 3 is a block diagram illustrating a control circuit of the sheet post-processing apparatus according to the first embodiment. FIG. FIG. 4 is an enlarged view of a staple processing tray and a half-fold processing tray portion according to the first embodiment. FIG. 10 is an operation explanatory diagram illustrating a state of a stack of sheets stacked on a staple processing tray in the saddle stitch binding mode. FIG. 10 is an operation explanatory diagram illustrating a state when the sheets are stacked on the staple processing tray and are saddle-stitched in the saddle stitch binding mode. FIG. 11 is an operation explanatory diagram illustrating an initial state in which a sheet bundle that is saddle-stitched on a staple processing tray is deflected by a sheet bundle deflection mechanism in the saddle stitching bookbinding mode. FIG. 10 is an operation explanatory diagram illustrating a state when a sheet bundle that is saddle-stitched in a staple processing tray is deflected by a sheet bundle deflection mechanism and sent to a half-folding processing tray in the saddle stitch binding mode. FIG. 10 is an operation explanatory diagram illustrating a state when a sheet bundle is positioned at a center folding position on the center folding processing tray in the saddle stitch binding mode. FIG. 11 is an operation explanatory diagram illustrating a state when a middle folding operation of a sheet bundle is started by operating a middle folding plate in a middle folding processing tray in the saddle stitching bookbinding mode. FIG. 10 is an operation explanatory diagram illustrating a state when a sheet bundle is folded from a middle folding processing tray by a middle folding roller and discharged in a saddle stitch binding mode. It is a figure which shows the relationship between the installation position of the rear-end | tip detection sensor 310 in 1st Embodiment, and a saddle stitch position. It is a flowchart which shows the control procedure in 1st Embodiment. It is a figure which shows the state of the bending of a large sized sheet bundle. It is a figure which shows the relationship between the three end surface detection sensors in 2nd Embodiment, a rear-end fence, and a saddle stitch position. It is a flowchart which shows the control procedure in 1st Embodiment.

Explanation of symbols

52 discharge belt 52a discharge claw 54 branch guide plate 55 movable guide 56 discharge roller 57 pressure roller 157 discharge motor 161 bundle branch drive motor 310 rear end detection sensor 310a, 310b, 310c end surface detection sensor 350 controller 360 CPU
370 I / O
F Staple processing tray G Half-fold processing tray PD Paper post-processing device PR Image forming device S1 Edge-stitched stapler S2 Saddle-stitched stapler F Staple processing tray G Middle-folding processing tray A, B, C, D, H, I Transport path PD Paper Post-processing device PR Image forming device S1 End stitching stapler S2 Saddle stitching stapler

Claims (6)

In a transporting means for transporting paper and a paper processing apparatus for performing a predetermined process on a paper bundle transported by the transporting means,
The predetermined processing is saddle stitching processing, and includes a control unit that determines a binding position at the time of saddle stitching processing based on information from a detection unit that detects a sheet bundle end portion, and executes the binding processing.
The sheet processing apparatus, wherein the control unit conveys a bundle of sheets conveyed by the conveyance unit by a preset amount from the binding position, and then moves the sheet bundle in the reverse direction to perform saddle stitching processing. The sheet processing apparatus according to claim 1, wherein the preset amount is set within a distance from a reference fence to the detection unit . The sheet processing apparatus according to claim 1, wherein the saddle stitching process is performed in a staple processing tray that temporarily stores and aligns sheets. The sheet processing apparatus according to claim 3 , wherein the detection unit is disposed on the staple processing tray . The sheet processing apparatus according to claim 4 , wherein the detection unit has a function of detecting the presence or absence of paper in the staple processing tray . An image forming apparatus comprising the sheet processing apparatus according to claim 1, either integrally or separately .

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