JP2008184327A - Post-processing device and image forming system with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a post-processing device capable of continuously receiving sheets from a sheet carry-in opening when performing post-processing to the sheets in a first and a second post-processing sections different from each other. <P>SOLUTION: This post-processing device comprises a first post-processing section for subjecting sheets from a sheet delivering opening to post-processing, a switch-back conveyance path for reversing the conveying direction of the sheets to transfer the sheets to a position different from the sheet carry-in route, a second post-processing section arranged on a downstream side of the switch-back conveyance path to subject the sheets to post-processing, a sheet delivery roller means arranged in the sheet delivering opening, a carry-in roller means arranged in a route inlet of the switch-back conveyance path, and a conveyance control means for controlling the sheet delivery roller means and the carry-in roller means. The conveyance control means controls a following sheet supplied to the carry-in opening during the post-processing operation in the first post-processing section so as to temporarily wait in the switch-back conveyance path, and after the post-processing operation in the first post-processing section is completed, the conveyance control means controls to transfer the following sheet waiting in the switch-back conveyance path to the first post-processing section. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a post-processing device that staples a sheet transported from an image forming apparatus such as a copying machine or a printer at a predetermined fold position, and efficiently post-processes the continuously transported sheet. It is related with the improvement of the apparatus structure which can be performed.

  In general, a post-processing apparatus that aligns sheets conveyed from an image forming apparatus and folds them into a staple or booklet is widely known. These post-processing apparatuses are provided with a plurality of sheet stacking means for post-processing the sheets. For example, the first sheet stacking means stacks the sheets in a bundle and staples them, and the second sheet stacking means in a bundle. The apparatus is configured to fold the accumulated sheets into a booklet.

  For example, Patent Document 1 discloses an apparatus that selectively carries out a sheet from an image forming apparatus through a path that branches into an upper first sheet stacking unit and a lower second sheet stacking unit. In this publication, two stapling devices are arranged in the sheet path leading to the first and second sheet stacking means, the sheets are stacked at the staple position, and the end edges of the sheets are bound with the first staple. The center of the sheet is saddle stitched with the second staple. Accordingly, the staple position is provided in one of the two branched paths, the sheets are bound, and then are carried out to the first and second trays. At this time, the second sheet stacking means positioned below is disclosed as an apparatus configuration for folding and storing stapled sheets in a booklet shape.

  Similarly, in Patent Document 2, the sheets from the image forming apparatus are switched back from the carry-in path and stacked on the sheet stacking unit, and this sheet bundle is bound on the end face by the stapling device disposed on the tray and is stored in the storage stacker on the rear side of the tray. Accommodate. On the other hand, a device configuration is disclosed in which the center of the sheet bundle on the tray is saddle-stitched and guided to the front side of the tray, and the sheet bundle is folded into a booklet shape by a folding path on the front side and stacked in a storage stacker.

  As described above, both of the above-described Patent Documents 1 and 2 have an apparatus configuration in which sheets are aligned and accumulated in a path (or tray) in which a stapling apparatus is arranged, and are distributed and conveyed to the first and second trays after stapling. Adopted. In Patent Document 3, the sheet from the image forming apparatus is guided to the first and second paths branched from each other, and the stacking and stapling are performed in each path, and one of the sheets is conveyed to the sheet discharge stacker in that state. On the other hand, there has been proposed an apparatus configuration in which a staple-bound sheet bundle is folded into a booklet shape and conveyed to a paper discharge stacker.

  In the post-processing apparatus configured as described above, the upstream image forming apparatus also performs subsequent processing even during the binding operation (staple binding operation and paper discharge operation to carry out the binding sheet to the tray) at the staple binding processing position. In general, image formation is continuously performed on subsequent sheets. Therefore, Patent Document 3 proposes an apparatus configuration in which a subsequent sheet on which an image has been formed during execution of a post-processing operation temporarily waits in a sheet carry-in path.

The publication discloses a path configuration in which a standby path is provided between a processing tray for stacking sheets for stapling and a sheet carry-in entrance, and a plurality of sheets following the standby path are temporarily standby. The standby path is composed of a switchback path.
JP 2000-63031 A JP 2000-169028 A JP 2004-269249 A

  In the case where both the staple binding mechanism and the sheet folding mechanism are incorporated into the apparatus in the apparatus for performing post-processing such as stapling, booklet folding, punch punching, etc., by aligning the sheet portion transported from the image forming apparatus as described above. The conventional apparatus configuration has the following problems.

  As described in Patent Documents 1 and 2, the sheets are guided to a common path, stapled into a bundle of sheets accumulated in this path, then distributed to the first and second stackers, and a sheet folding mechanism in one of the paths. In the apparatus configuration in which the sheets are arranged, there is a problem in the processing efficiency of the sheets that are continuously carried out. For example, during the operation time for performing stapling processing on a sheet bundle accumulated by the stapling apparatus, it is necessary to stop carrying out subsequent sheets. This is also the case when the sheet bundle to be punched is subjected to end face binding processing by the stapling device and carried out to the first stacker, and the subsequent sheet is subjected to saddle stitching processing by the stapling device and conveyed to the second stacker via the folding mechanism. Until the processing of the sheet bundle to be performed is completed, the processing of subsequent sheets cannot be executed in parallel. Further, even when a trouble such as a sheet jam occurs in the stapling apparatus or the like, if the entire apparatus is not immediately stopped, the subsequent sheet is jammed.

  As described above, if the upstream image forming apparatus is stopped during the post-processing operation and the system is operated and controlled so that the subsequent sheet does not cause a paper jam in the apparatus, the processing time is slow and inefficient. In view of this, it has been proposed that a standby path is provided in the sheet carry-in path of the post-processing apparatus as in the above-mentioned Patent Document 3, and a subsequent sheet continuously created by the image forming apparatus is temporarily held in this standby path. However, such a standby path is provided separately from the sheet carry-in path, and it is necessary to incorporate a conveyance mechanism for carrying the sheet in, then holding it, and refeeding the sheet. Problem occurs. For example, in consideration of adopting a jam processing mechanism for removing a jammed sheet on the standby path, the apparatus cannot be increased in size and complexity.

  Accordingly, the present inventor provides first and second switchback conveyance paths from the linear carry-in path for sheets from the image forming apparatus, and a post-processing apparatus such as a stapling means and a paper folding means is provided in each switchback conveyance path. In this case, the idea is to wait for the sheet following the second switchback conveyance path during the operation of performing the predetermined post-processing in the first switchback conveyance path. This makes it possible to post-process consecutive sheets without providing a special standby path.

  Accordingly, the present invention provides a post-processing apparatus capable of continuously receiving sheets from a sheet carry-in port when post-processing sheets conveyed from an image forming apparatus or the like by different first and second post-processing units. Providing is the main challenge. Further, according to the present invention, the first post-processing unit waits in the path for transporting the sheet to the second post-processing unit without specially providing a path for waiting for the subsequent sheet during the processing operation for performing post-processing on the sheet. Accordingly, it is an object of the present invention to provide a post-processing apparatus and an image forming system provided with the post-processing apparatus that can be configured to be compact and compact and can be easily controlled.

The present invention employs the following configuration in order to solve the above problems.
This is a post-processing device that transfers sheets from the sheet carry-in port to different first and second post-processing units, and performs post-processing such as stapling and sheet folding on the sheets in the first and second post-processing units. A sheet carry-in path for sequentially transferring the sheets supplied to the carry-in entrance to a predetermined paper discharge opening, and a post-process for the sheet from the paper discharge opening disposed on the downstream side of the paper discharge opening in the sheet carry-in path. A post-processing unit, and a switchback conveyance path that branches from between the carry-in entrance and the paper discharge opening of the sheet carry-in path and reverses the sheet conveyance direction to transfer the sheet to a position different from the sheet carry-in path. A second post-processing unit that is disposed downstream of the switchback conveyance path and performs post-processing on the sheet; a discharge roller means disposed at a discharge port of the sheet carry-in path; and the switchback conveyance Carry in at the route entrance of the road Comprising a chromatography La means, and a transport control means for controlling the feed-in rollers means and the discharge roller unit.

  The conveyance control means causes the succeeding sheet to be supplied to the carry-in entrance during the post-processing operation in the first post-processing unit to temporarily wait in the switchback conveyance path, and post-processing of the first post-processing unit. The discharge roller means and the carry-in roller means are controlled so that the subsequent sheet waiting in the switchback conveyance path after the operation is transferred to the first post-processing section.

  The conveyance control unit temporarily superimposes a plurality of sheets sequentially supplied to the carry-in inlet during the post-processing operation in the first post-processing unit on the switchback conveyance path, and The discharge roller means and the carry-in roller means are controlled so that a plurality of subsequent sheets waiting in the switchback conveyance path after the processing section finishes the post-processing operation are transferred to the first post-processing section.

  When the plurality of sheets are placed on the switchback conveyance path and waited, the control means intermittently drives the carry-in roller means to offset the overlapping sheets by a predetermined amount in the front-rear direction.

  The first post-processing unit is provided with a sheet stacking unit that stacks and stores sheets from the sheet discharge port. The sheet stacking unit includes a sheet end regulating unit that abuts and regulates a sheet end, and the regulating unit. An aligning / conveying means for transferring the sheet is provided. The control unit sets an offset amount when a plurality of sheets are offset to the switchback conveyance path by a predetermined amount so as to be longer than an interval between the sheet end regulating unit and the aligning conveyance unit.

  The paper discharge roller means and the carry-in roller means are configured at an interval that is at least shorter than the length in the conveyance direction of the maximum size sheet, and the paper discharge roller means is configured by a pair of rollers that can be pressed against and separated from each other. The control means superimposes the standby sheet waiting on the switchback conveyance path and the succeeding sheet supplied to the carry-in entrance with the paper discharge rollers spaced apart, and the paper discharge roller means performs the first post-processing. Control to transfer to the part.

  The first processing unit is provided with first sheet stacking means for stacking and aligning the sheets from the paper discharge port, and the second processing unit is configured to stack sheets from the switchback conveyance path. Then, the second sheet stacking means for aligning the parts is arranged. The first sheet stacking means includes end face binding staple means for binding the edges of the stacked sheets, and the second sheet stacking means includes saddle stitching staple means for binding the central portion of the stacked sheet bundle. Deploy.

  On the upstream side of the first switchback conveyance path, a sheet carry-in path having a carry-in entrance for sequentially carrying sheets, a first switchback conveyance path that branches from the sheet carry-in path and reverses the sheet conveyance direction, and A second switchback conveyance path that branches off from the sheet carry-in path and reverses the sheet conveyance direction, and is connected to the first switchback conveyance path to stack and stack the sheets in a bundle. A stacking unit, a second sheet stacking unit that is connected to the second switchback conveyance path and stacks and stacks sheets in a bundle, and an edge of the stacked sheets disposed in the first sheet stacking unit is bound. End-stitched stapling means for matching, folding roll means for folding the stacked sheets disposed in the second sheet stacking means, and paper discharge disposed in the sheet discharge path of the sheet carry-in path Comprising a chromatography La means, a feed-in rollers means disposed in the path inlet of the switchback path, a conveyance control means for controlling the feed-in rollers means and the discharge roller unit.

  The conveyance control means temporarily waits the succeeding sheet supplied to the carry-in entrance during the binding operation of the end face binding staple means in the switchback conveyance path, and the switchback after the binding operation of the staple means ends. The discharge roller means and the carry-in roller means are controlled so that the succeeding sheet waiting in the conveyance path is transferred from the first switchback conveyance path to the first sheet stacking means.

  A sheet locking member for temporarily holding a sheet reaching the second switchback conveyance path is disposed on the upstream side of the second switchback conveyance path in the sheet carry-in path.

  An image forming system according to the present invention includes an image forming apparatus that sequentially forms an image on a sheet, and a post-processing apparatus that performs post-processing such as stapling, stamping, and punching on the sheet from the image forming apparatus. And the said post-processing apparatus is provided with one of the said structures.

  In the present invention, a first post-processing unit is disposed on the downstream side of the sheet carry-in path, and a second post-processing unit is disposed on the downstream side of the switchback conveyance path branched from the sheet carry-in path. Since the subsequent sheet during the post-processing operation is temporarily held in the switchback conveyance path to the second post-processing unit, the subsequent sheet is executed during the execution of the processing operation by the first post-processing unit. The sheet can be waited on the switchback conveyance path of the second post-processing section, and there is no need to provide a special standby path. Therefore, the apparatus can be made compact and compact, and control for that is easy.

  Further, since the switchback conveyance path for waiting the subsequent sheet is a cardboard sheet for waiting the sheet in a substantially linear path, a plurality of sheets can be placed on standby.

  Further, a first switchback conveyance path is provided downstream of the sheet carry-in path for carrying in sheets, and a second switchback path is provided upstream of the first switchback path. The sheet guided from the sheet carry-in path to the first and second switchback paths by being configured to feed the sheet from the second switchback transport path to the second post-processing section is a path that is relatively straight. Therefore, even a cardboard sheet or a sheet having a small friction coefficient can be reliably and stably conveyed. Therefore, no conveyance traces such as wrinkles and image rubbing remain on the sheet.

  At the same time, the sheet supplied to the sheet carry-in path can be guided from the first switchback transport path to the first processing section and to the second post-processing section through the second switchback transport path. Even if the succeeding sheet processing operation is different, it is possible to carry the succeeding sheet into the apparatus, and it is possible to efficiently process the continuous sheet processing at high speed.

  The present invention will be described in detail below based on the preferred embodiments shown in the drawings. FIG. 1 shows an overall configuration of an image forming system according to the present invention, FIG. 2 is an explanatory diagram of the overall configuration of a post-processing apparatus, and FIG. 3 is an explanatory diagram showing a detailed configuration of a sheet folding unit. Therefore, the image forming system shown in FIG. 1 includes an image forming apparatus A and a post-processing apparatus B. The post-processing apparatus B incorporates a sheet folding apparatus C as a unit.

[Configuration of Image Forming Apparatus]
The image forming apparatus A shown in FIG. 1 sends a sheet from the sheet feeding unit 1 to the image forming unit 2, prints the sheet on the image forming unit 2, and then carries the sheet out from the main body discharge port 3. The sheet feeding unit 1 stores sheets of a plurality of sizes in sheet feeding cassettes 1 a and 1 b, and separates designated sheets one by one and feeds them to the image forming unit 2. The image forming unit 2 includes, for example, an electrostatic drum 4, a print head (laser light emitting device) 5 and a developing device 6 arranged around the electrostatic drum 4, a transfer charger 7, and a fixing device 8. An electrostatic latent image is formed by the light emitting device 5, toner is adhered to the developing device 6, an image is transferred onto the sheet by the transfer charger 7, and heat fixing is performed by the fixing device 8. The sheets on which images are formed in this way are sequentially carried out from the main body discharge port 3. 9 is a circulation path, and the sheet printed on the front side from the fixing device 8 is turned upside down through the main body switchback path 10 and then fed again to the image forming unit 2 to print on the back side of the sheet. This is the path for duplex printing. The sheet printed on both sides in this way is turned upside down by the main body switchback path 10 and then carried out from the main body discharge port 3.

  11 is an image reading apparatus, which scans a document sheet set on a platen 12 with a scanning unit 13 and electrically reads it with a photoelectric conversion element (not shown). The image data is digitally processed by an image processing unit, for example, and then transferred to the data storage unit 14 to send an image signal to the laser emitter 5. 15 is a document feeder, which is a feeder device that feeds document sheets stored in the stacker 16 to the platen 12.

  The image forming apparatus A configured as described above is provided with a control unit (controller) shown in FIG. 9, and image forming conditions such as sheet size designation, color / monochrome printing designation, print number designation, single-sided / double-sided printing designation from the control panel 18. The printout conditions such as enlargement / reduction print designation are set. On the other hand, image data read by the scan unit 13 or image data transferred from an external network is stored in the data storage unit 17 in the image forming apparatus A, and the image data is transferred from the data storage unit to the buffer memory. Data signals are sequentially transferred from the buffer memory 19 to the laser emitter 5.

  From the control panel 18, post-processing conditions are also input and specified simultaneously with the image forming conditions. As the post-processing conditions, for example, “print-out mode”, “staple binding mode”, “sheet bundle folding mode”, or the like is designated. The image forming apparatus A forms an image on the sheet according to the image forming condition and the post-processing condition. This image forming mode will be described with reference to FIG. 5. When “single-sided printing” is set as the image forming condition and “print out mode” or “staple binding mode” is set as the post-processing condition, the image forming unit 2 designates A predetermined image is formed on the sheet, and the sheet is turned upside down by the main body switchback path 10 and then carried out to the main body discharge port 3.

  Accordingly, the image forming apparatus A sequentially forms a series of sheets from the first page to the nth page. A post-processing apparatus B, which will be described later, receives sheets carried out face down from the first page. When in the “print-out mode”, the sheets are sequentially stacked and stored in the first paper discharge tray 21 arranged in the post-processing apparatus B. In the “staple binding mode”, the sheets are stacked and stored in the first stacking unit 29 disposed in the post-processing apparatus B. Then, the sheets stacked on the tray are bound together by an end face binding and stapling device 33 which will be described later in response to a job end signal, and stored in the first paper discharge tray 21.

  Also, when double-sided printing and 2-in-1 printing are specified in the image forming conditions and “sheet bundle folding mode” is set as post-processing, when the last page is n pages as shown in FIG. (N / 2) page image and (n / 2 + 1) page image on the front side of the sheet, and (n / 2-1) page image and (n / 2 + 2) page on the back side. Are formed and carried out from the paper discharge outlet 3. Then, the post-processing apparatus B described later stores the sheet in the second stacking unit 35 from the sheet carry-in path P1. Next, the image forming apparatus A prints the (n / 2-2) page image and the (n / 2 + 3) page image on the front side of the next sheet, and the (n / 2-3) page on the back side. And the (n / 2 + 4) th page image are printed out from the main body discharge port 3. Then, the post-processing apparatus B stacks and accumulates the sheets on the previous sheet. In this manner, the image forming apparatus A forms an image in an order suitable for the stacking tray structure of the post-processing apparatus B. Such a page order controls the print head (laser emitter) 5 by calculating the print order when transferring image data from the data storage unit 17 to the buffer memory 19.

[Configuration of post-processing equipment]
The post-processing apparatus B connected to the image forming apparatus A receives a sheet on which an image is formed from the main body discharge port 3 of the image forming apparatus A, and (1) stores the sheet in the first discharge tray 21. (The above-mentioned “print-out mode”) (2) The sheets from the main body discharge port 3 are aligned in a bundle and stapled, and then stored in the first discharge tray 21 (the above-mentioned “staple binding”). Mode ") (3) After the sheets from the main body discharge port 3 are aligned in a bundle, they are folded into a booklet and stored in the second discharge tray 22 (the above-mentioned" sheet bundle folding mode "). Has been.

  Therefore, as shown in FIG. 2, the post-processing apparatus A includes the first paper discharge tray 21 and the second paper discharge tray 22 in the casing 20, and a sheet carry-in path P <b> 1 having a carry-in port 23 connected to the main body discharge port 3. Is provided. The sheet carry-in path P <b> 1 is configured by a substantially horizontal straight path in the casing 20. A first switchback conveyance path SP1 and a second switchback conveyance path SP2 that branch from the sheet carry-in path P1 and transfer the sheet in the reverse direction are arranged. The first switchback transport path SP1 is branched from the sheet carry-in path P1 on the downstream side and the second switchback transport path SP2 is branched on the upstream side of the path, and the both transport paths are arranged at a distance from each other.

  In such a path configuration, the carry-in roller 24 and the paper discharge roller 25 are arranged in the sheet carry-in path P1, and these rollers are connected to a drive motor M1 (not shown) that can be rotated forward and backward. Further, a path switching piece 27 for guiding the sheet to the second switchback conveying path SP2 is disposed in the sheet carry-in path P1, and is connected to an operating means such as a solenoid. Further, a post-processing unit 28 such as a stamp unit that performs a stamping process on a sheet from the carry-in port 23 or a punch unit that performs a punching process is provided between the carry-in port 23 and the carry-in roller 24 in the sheet carry-in path P1. The illustrated post-processing unit 28 is arranged on the upstream side of the carry-in roller 24 at the carry-in entrance 23 so that it can be attached to and detached from the casing 20 according to the specifications of the apparatus.

  In the sheet carry-in path P1 described above, a sheet locking member that temporarily holds a sheet that reaches the second switchback conveyance path SP2 on the upstream side of the branch path (path switching piece 27 position) of the second switchback conveyance path SP2. A (buffer guide) 26 is arranged. Its configuration and operation will be described later.

[Configuration of the first switchback transport path SP1]
As described above, the first switchback conveyance path SP1 disposed on the downstream side (rear end portion of the apparatus) of the sheet carry-in path P1 is configured as follows. A discharge roller 25 and a discharge port 25a are provided at the exit end of the sheet carry-in path P1, and a first stacking unit 29 is provided below the discharge port 25a with a step difference. The first stacking unit 29 includes a tray (hereinafter referred to as “stacking tray 29”) for stacking and supporting sheets from the sheet discharge outlet 25a. Above the stacking tray 29, a forward / reverse roller 30 is disposed so as to be movable up and down between a position in contact with the sheet on the tray and a separated standby position (a chain line position in FIG. 3). A forward / reverse motor M2 is connected to the forward / reverse roller 30 and rotates in the clockwise direction when the sheet enters the stacking tray 29, and rotates in the counterclockwise direction after the trailing edge of the sheet enters the tray. To be controlled. Accordingly, a first switchback transport path SP1 is formed on the stacking tray 29. 31 is a caterpillar belt, and the discharge roller 25 and one end pulley side are pressed against each other, and the end pulley side is pivotally supported so as to be suspended from the collecting tray 29 around the pulley shaft 31a. A driven roller 30 b shown in the figure is engaged with the forward / reverse roller 30 and is provided on the stacking tray 29.

  A first paper discharge tray 21 is disposed on the downstream side of the first switchback conveyance path SP1, and the first paper discharge tray 21 is guided to the first switchback conveyance path SP1 and the second switchback conveyance path SP2. It is comprised so that the front-end | tip of a sheet | seat may be supported.

  With the above configuration, the sheet from the sheet discharge outlet 25a enters the stacking tray 29 and is transferred toward the first sheet discharge tray 21 by the forward / reverse rotation roller 30, and the rear end of the sheet enters the stacking tray 29 from the sheet discharge outlet. After that, when the forward / reverse roller 30 is rotated in the reverse direction (counterclockwise in the figure), the sheets on the stacking tray 29 are transferred in the direction opposite to the paper discharge direction. At this time, the caterpillar belt 31 switches back and conveys the sheet trailing edge along the stacking tray 29 in cooperation with the forward / reverse roller 30.

  A rear end regulating member 32 for regulating the position of the rear end of the sheet and an end face binding staple device 33 are disposed at the rear end of the stacking tray 29 in the paper discharge direction. The illustrated stapling device 33 is constituted by an end-face binding stapler, and staples the staple at one place or a plurality of places on the rear end edge of the sheet bundle stacked on the tray. Further, the trailing edge regulating member 32 reciprocates in the paper discharge direction along the stacking tray 29 in order to share the function of carrying out the staple-bound sheet bundle to the first paper discharge tray 21 disposed on the downstream side of the stacking tray 29. It is configured to move freely. The carry-out mechanism of the illustrated rear end regulating member 32 includes a grip claw 33a that grips the sheet bundle and a rear end regulating surface 33b that abuts and regulates the rear end of the sheet, and extends in the horizontal direction in the figure along a guide rail provided on the apparatus frame. It is configured to be movable. Reference numeral 34a in the figure denotes a drive arm that reciprocates the rear end regulating member 32, and is connected to the paper discharge motor M3.

  The stacking tray 29 is provided with a side alignment plate 34b for aligning the width direction of the sheets stacked on the tray. The side alignment plate 34b is arranged on the left and right sides (around FIG. 3) so as to align the sheets with the center reference. It is composed of a pair of alignment plates, is configured to approach and separate from the center of the sheet, and is connected to an alignment motor (not shown).

  The first switchback transport path SP1 configured as described above aligns the sheets from the sheet discharge outlet 25a on the stacking tray 29 in the “staple binding mode”, and the sheet bundle is bound by the end face binding stapler 33. Staple binding is performed at one or a plurality of locations on the trailing edge. In the “print-out mode”, the sheet fed along the stacking tray 29 is conveyed between the forward / reverse roller 30 and the driven roller 30b without the switchback conveyance of the sheet from the sheet discharge port 25a. It is carried out to the paper tray 21. In this way, the illustrated apparatus is characterized in that the apparatus is compactly configured by supporting the sheets to be stapled by the stacking tray 29 and the first discharge tray 21 in a bridge manner.

[Configuration of second switchback transport path]
The configuration of the second switchback conveyance path SP2 branched from the sheet carry-in path P1 will be described. As shown in FIG. 4, the second switchback transport path SP2 is disposed in a substantially vertical direction in the apparatus casing 20, and a transport roller 36 is disposed at the path entrance and a transport roller 37 is disposed at the path exit. Further, a second stacking unit 35 for aligning the sheets sent from the transport path is provided on the downstream side of the second switchback transport path SP2. The illustrated second stacking unit 35 includes a conveyance guide (stacking guide unit) for transporting sheets (hereinafter referred to as “stacking guide 35”). The accumulation guide 35 is provided with a saddle stitching staple device 40 and a folding roll means 45. Hereinafter, these configurations will be sequentially described.

  The transport roller 36 disposed at the path entrance of the second switchback transport path SP2 is configured to be capable of forward and reverse rotation, and a sheet carried into the first switchback transport path SP1 on the downstream side is temporarily transferred to the second switchback transport path SP2. It is held (stayed) in the transport path SP2. This is because the preceding sheets are stacked on the stacking tray 29, stapled by a job end signal, and then sent to the sheet transport path P1 from the image forming apparatus A while the sheet bundle is transported to the first paper discharge tray 21. This is for temporarily holding the sheet in the second switchback conveyance path SP2 and conveying the standby sheet from the first switchback conveyance path SP1 onto the stacking tray 29 after the processing of the preceding sheet is completed. Its operation will be described later.

  First, the accumulation guide 35 is formed by a guide member that guides conveyance of the sheet, and is configured to stack and store the sheet on the guide. The illustrated accumulation guide 35 is connected to the second switchback conveyance path SP <b> 2 and is disposed substantially vertically in the center of the apparatus casing 20. As a result, the apparatus is made compact and compact. The accumulation guide 35 is formed in a length shape that accommodates the maximum size sheet therein, and in particular, the illustrated guide is bent or bent so as to protrude to the side where the saddle stitching staple device 40 and the folding roll means 45 described later are disposed. It is configured in shape.

  A switchback entry path 35a that overlaps with the outlet end of the second switchback transport path SP2 is connected to the rear end side of the stacking guide 35 in the transport direction. This stacks by overlapping the leading edge of the loaded (following) sheet sent from the conveying roller 37 of the second switchback conveying path SP2 and the trailing edge of the stacked (preceding) sheet supported by the stacking guide 35. This is for securing the page order of sheets. Further, the accumulation guide 35 is provided with a leading edge regulating member 38 for regulating the leading edge of the sheet on the downstream side of the guide. The leading edge regulating member 38 is supported by a guide rail or the like so as to be movable along the accumulation guide 35, and shift means MS. (Not shown) is configured to move between the illustrated sh1, sh2, and sh3.

  When the leading end regulating member 38 is positioned at the illustrated position Sh3, the rear end of the sheet (bundle) supported by the stacking guide 35 enters the switchback entry path 35a and is sent from the second switchback conveyance path SP2 in this state. Subsequent sheets will surely be stacked above the stacked sheets. When the leading end regulating member 38 is positioned at the illustrated position Sh2, the center of the sheet (bundle) supported by the stacking guide 35 is positioned at the binding position X of the saddle stitching staple device 40 described later. Similarly, when the leading end regulating member 38 is positioned at the illustrated position Sh1, the center of the sheet bundle that is stapled and supported by the stacking guide 35 is positioned at a folding position Y of a folding roll means 45 described later. Accordingly, the illustrated positions Sh1, Sh2, and Sh3 are set to optimum positions according to the sheet size (length in the conveyance direction).

  A sheet side edge aligning member 39 is disposed on the accumulation guide 35 on the downstream side in the sheet conveying direction. The sheet side edge aligning member 39 is aligned so that the position in the width direction of the sheet carried into the stacking guide 35 and supported by the leading end regulating member 38 is matched with the reference. That is, the sheet side edge alignment member 39 aligns the width of the sheet side edge with the sheet side edge alignment member 39 in a state where the sheet leading edge regulating member 38 is located at the position of Sh3 and the entire sheet is supported by the accumulation guide 35. In the illustrated apparatus, the sheet side edge aligning member 39 is composed of a pair of left and right aligning plates so that the sheets are aligned with respect to each other based on the center reference. The sheet bundle supported on the sheet is aligned and aligned. For this reason, the sheet side edge alignment member 39 is connected to an alignment motor M5 (not shown).

[Configuration of Saddle Stitcher]
A binding position X is set on the upstream side and a folding position Y is set on the downstream side along the above-described accumulation guide 35, and the saddle stitching staple device 40 is disposed in the binding position X. This apparatus includes a driver unit 40A and an anvil unit 40B, and each unit is configured to be separated at opposing positions with the integrated guide 35 interposed therebetween. A needle cartridge is mounted on the driver unit 40A, and a needle connected in a belt shape is built in the cartridge. The needle member at the tip is bent into a U shape by the former member by a driver member that moves up and down between the upper dead center and the lower bottom dead center, and then this needle is inserted into the sheet bundle. Has been. Accordingly, the driver unit 40A includes a drive motor M, a drive arm that moves the driver member up and down, a drive cam that drives the arm, and the like.

On the other hand, the anvil unit 40B is provided with a bending groove (not shown) for bending the tip of the staple needle inserted into the sheet bundle. The saddle stitching and stapling apparatus 40 configured as described above is configured such that the driver unit 40A and the anvil unit 40B are separated from each other so that a sheet bundle can pass between them. Accordingly, it is possible to staple the central portion of the sheet bundle and other arbitrary positions.

[Configuration of folding roll means]
At the folding position Y arranged on the downstream side of the stapling apparatus 40, a folding roll means 45 for folding the sheet bundle and a folding blade 46 for inserting the sheet bundle at the nip position NP of the folding roll means 45 are provided. . As shown in FIG. 6A, the folding roll means 45 is composed of rolls 45a and 45b that are in pressure contact with each other, and each roll is formed to have a substantially maximum sheet width. The pair of rolls 45a and 45b are fitted in the long grooves of the apparatus frame so that the rotary shafts 45ax and 45bx are pressed against each other, and are urged in the press-contact direction by the compression springs 45aS and 45bS. In addition, at least one of the rolls may be supported by a shaft so as to be movable in the press-contact direction, and a biasing spring may be stretched over one of the rolls.

  The pair of rolls 45a and 45b are formed of a material having a relatively large friction coefficient such as a rubber roller. This is because the sheet is bent and transferred by a soft material such as rubber, and may be formed by lining the rubber material. The folding roll means 45 is formed in an uneven shape as shown in FIG. 6B, and a gap 45g is formed in the sheet value width direction. The gap 45g is arranged so as to coincide with the unevenness of the folding blade 46, which will be described later, and consideration is given so that the tip of the folding blade can easily enter between the roll nips. At the same time, the gap 45g is arranged at a width position that coincides with a staple binding portion for binding the sheet bundle. In other words, the pair of rolls 45a and 45b that are pressed against each other are formed in a concavo-convex shape having a gap (gap 45g) in the sheet width direction. The cutting edge enters.

  Each of the rolls 45a and 45b is connected to a roll driving means RM. The illustrated roll drive means RM is composed of a roll drive motor M6 and a transmission mechanism (transmission means) 47V as shown in FIG. The illustrated transmission means 47V is composed of a transmission belt that decelerates the rotation of the roll drive motor M6 and transmits it to the transmission shaft 47X. Clutch means 45c is disposed between the transmission shaft 47X and the rotation shaft 45ax of the first folding roll 45a. Similarly, a clutch means 45c is also arranged between the second folding roll 45b and the rotation shaft 45bx. This clutch means 45c is an electromagnetic clutch, a one-way clutch (one-way clutch), a sliding friction clutch (spring clutch), etc., and the driving rotation of the roll drive motor M6 is turned on to the first folding roll 45a and the fourth second folding roll 5b, Configure so that it can be turned off.

  The illustrated clutch means 45c is constituted by a one-way clutch, and is configured to transmit the rotation of the transmission shaft 47X to the transmission collar 47Z only in one direction between the transmission shaft 47X and the transmission collar 47Z. The first folding roll 45a is gear-connected to the transmission collar 47Z, and the second folding roll 45b is belt-connected. Thus, only one direction of rotation of the motor is transmitted to the first and second folding rolls 45a and 45b connected to the roll drive motor M6 via the clutch means 45c, and at the same time, the roll freely rotates in the sheet feeding direction. It is configured to be possible.

  The pair of rolls 45a and 45b described above are positioned on the curved or bent protruding side of the stacking guide 35, and are separated from the sheet bundle supported by the stacking guide 35 by a distance h shown in FIG. Has been placed. That is, the sheet (bundle) supported by the accumulation guide 35 is disposed at a position where the roll surface does not come in contact with the distance h. And the folding blade 46 which has a knife edge is provided in the position which opposes on both sides of a sheet | seat bundle. The folding blade 46 is supported by the apparatus frame so as to be able to reciprocate between the standby position in FIG. 8A and the nip position in FIG. Blade driving means BM is connected to the folding blade 46. The folding blade 46 is configured to reciprocate by a blade driving motor M7 between a standby position retracted from the sheet bundle supported by the stacking guide 35 and a nip position NP between the press-contacts of the folding roll means 45. The folding blade 46 is formed in a plate shape with a material having a relatively small coefficient of friction such as metal, and the tip thereof is formed in an uneven surface as shown in FIG. As described above, the blade tip is formed into a shape that enters the roll cap 45g.

  Therefore, in the illustrated example, the relationship between the friction coefficient ν1 between the first and second folding rolls 45a and 45b and the sheet, the friction coefficient ν2 between the sheets, and the friction coefficient ν3 between the sheet and the folding blade 46 is as follows. The relation of “ν1> ν2> ν3” is set. Therefore, in the state where the sheet bundle shown in FIG. 8C is inserted between the first folding roll 45a and the second folding roll 45b by the folding blade 46, the pressure contact force acting on both folding rolls 45a and 45b is It reaches each as equal force on the sheet bundle and folding blade. At this time, since the friction coefficient is set to the above relationship, the sheet bundle is smoothly fed in the feeding direction (left side in the figure).

  Next, the configuration of the blade driving means BM of the folding blade 46 will be described. As shown in FIG. 7B, the folding blade 46 is supported on the apparatus frame by a guide rail 46g so as to be movable in the sheet folding direction. The folding blade 46 is supported so as to be able to reciprocate between a standby position retracted from the sheet supported by the accumulation guide 35 and a nip position NP of the folding roll means 45. The blade drive means BM for reciprocating the folding blade 46 is a blade drive motor M7 and a transmission means 46V for transmitting the rotation thereof, and the illustrated one is transmitted to the transmission rotation shaft 46X by a transmission belt. The transmission rotation shaft 46X is provided with a transmission pinion 46P and meshed with a rack gear 46L attached integrally to the folding blade 46.

  Accordingly, when the blade drive motor M7 rotates forward and backward, the folding blade 46 reciprocates between the standby position and the nip position NP along the guide rail 46g. The folding blade 46 is composed of a plate-like member having a knife edge in the sheet width direction, and its tip is formed in an uneven shape as shown in the figure.

  Next, the sheet folding state by the folding roll means 45 and the folding blade 46 having the above-described configuration will be described with reference to FIGS. First, the sheet bundle supported by the stacking guide 35 in the form of a bundle is locked to the leading end regulating member 38 in the state shown in FIG. 5A, and the fold position is positioned at the folding position Y in the stapled state. Upon obtaining this sheet bundle setting end signal, the drive control means (sheet folding operation control section, which will be described later) 64d turns off the clutch means 45c. In the illustrated one-way clutch configuration, the roll drive motor M6 is stopped, or the motor M6 is rotated at a lower speed than the moving speed of the folding blade 46. This is to create a condition in which the first and second folding rolls 45a and 45b are driven to rotate by a sheet bundle inserted into the nip position by the folding blade 46, as will be described later.

  Accordingly, the drive control means 64d moves the folding blade 46 from the standby position toward the nip position NP at a predetermined speed. The rotational peripheral speed VR of the folding roll means 45 is set to zero or VB> VR with respect to the moving speed VB. Therefore, in the state of FIG. 8B, the sheet bundle is bent at the fold position by the folding blade 46 and inserted between the rolls. At this time, the first folding roll 45 a and the second folding roll 45 b are driven and rotated continuously with the sheet moving by the folding blade 46. The drive control means 64d stops the blade drive motor M7 after the expected time for the sheet bundle to reach the predetermined nip position, and stops the folding blade 46 at the position shown in FIG. Before and after this, the drive control means 64d switches the clutch means 45c to the ON state to drive and rotate the first and second folding rolls 45a and 45b. Then, the sheet bundle is sent out in the feeding direction (left side in the figure). Thereafter, the drive control means 64d moves and returns the folding blade 46 located at the nip position NP to the standby position in parallel with the feeding of the sheet bundle by the roll in the state shown in FIG.

  When the sheet bundle thus folded is first engulfed between the pair of rolls 45a and 45b, the sheet contacting the roll surface is not drawn between the rolls by the rotating roll. That is, the folding roll means 45 follows (follows) and rotates with the inserted (pushed) sheet, so that only the sheet in contact with the roll is not first wound. In addition, since the folding roll follows the inserted sheet and is driven to rotate, the roll surface and the sheet in contact therewith are not rubbed and image rubbing is not caused.

[Description of control configuration]
The control configuration of the above-described image forming system will be described with reference to the block diagram of FIG. The image forming system shown in FIG. 1 includes a control unit (hereinafter referred to as “main body control unit”) 50 of the image forming apparatus A and a control unit (hereinafter referred to as “post-processing control unit”) 60 of the post-processing apparatus B. The main body control unit 50 includes an image formation control unit 51, a paper feed control unit 52, and an input unit 53. Then, the “image forming mode” and “post-processing mode” are set from the control panel 18 provided in the input unit 53. As described above, the image forming mode sets the number of printouts, sheet size, color / monochrome printing, enlargement / reduction printing, duplex / single-sided printing, and other image formation conditions. Then, the main body control unit 50 controls the image formation control unit and the paper feed control unit according to the set image forming conditions, and after the image is formed on a predetermined sheet, the sheets are sequentially carried out from the main body discharge port 3.

  At the same time, the post-processing mode is set by input from the control panel 18. The post-processing mode is set to, for example, “print-out mode”, “staple binding finishing mode”, “sheet bundle folding finishing mode”, or the like. Therefore, the main body control unit 50 transfers the post-processing finishing mode, the number of sheets, the upper number of copies, and the binding mode (one-position binding or two or more bindings) information to the post-processing control unit 60. At the same time, the main body control unit transfers a job end signal to the post-processing control unit 60 every time image formation is completed.

  The post-processing control unit 60 includes a control CPU 61 that operates the post-processing apparatus B in accordance with a designated finishing mode, a ROM 62 that stores an operation program, and a RAM 63 that stores control data. The control CPU 61 includes a conveyance control unit 64a that performs conveyance of the sheet sent to the carry-in entrance 23, a stacking operation control unit 64b that performs the stacking operation of sheets, and a binding operation control unit 64c that performs sheet binding processing. And a sheet folding operation control unit 64d for executing a sheet folding operation.

  The conveyance control unit 64a is connected to the control circuit of the driving motor M1 for the conveyance roller 24 and the discharge roller 25 in the sheet carry-in path P1 and receives a detection signal from the sheet sensor S1 disposed in this path. It is configured. Further, the stacking operation control unit 64b includes a driving circuit for the forward / reverse rotation motor M2 of the forward / reverse rotation roller 30 and the discharge motor M3 of the rear end regulating member in order to stack sheets on the first stacking unit (stacking tray) 29. Connected. Further, the binding operation control unit 64c is connected to a drive circuit of a drive motor M incorporated in the saddle stitching stapling device 40 of the end stacking stapling device 33 and the second stacking unit (stacking guide) 35 of the first stacking unit 29. Yes.

  The sheet folding operation control unit 64d is connected to a drive circuit of a roll drive motor M6 that drives and rotates the first and second folding rolls 45a and 45b and a drive circuit of the clutch means 45c. The sheet folding operation control unit 64d is connected to a control circuit of a shift unit MS that controls the movement of the conveying rollers 36 and 37 of the second switchback conveying path SP2 and the leading end regulating unit 38 of the stacking guide 35 to a predetermined position. Wires are connected so as to receive detection signals from the sheet sensors arranged in these paths.

The control unit configured as described above causes the post-processing device to execute the next processing operation.
"Printout mode"
In this mode, the image forming apparatus A forms an image of a series of documents, for example, from the first page, and sequentially carries out face-down from the main body discharge port 3. Therefore, the post-processing apparatus B retracts the buffer guide 26 in the sheet carry-in path P1 upward in FIG. 3, and moves the path switching piece 27 to the state of the solid line in FIG. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 25. Therefore, after the expected time that the leading edge of the sheet reaches the forward / reverse roller 30 of the stacking tray 29 based on the signal that the leading edge of the sheet is detected at the paper discharge port 25a, the transport controller 64a lowers the forward / reverse roller 30 from the upper standby position onto the tray. The forward / reverse roller 30 is rotated in the clockwise direction in FIG. Then, the sheet that has entered the stacking tray 29 is carried out toward the first paper discharge tray 21 by the forward / reverse rotation roller 30 and stored on the tray. The successive sheets are sequentially carried out to the first paper discharge tray 21 and accumulated and stored on the tray.

  Accordingly, in this printout mode, the sheets on which the image is formed by the image forming apparatus A are accommodated in the first paper discharge tray 21 via the sheet carry-in path P1 of the post-processing apparatus B. The pages are stacked and stored in the order of the pages. In this mode, no sheet is guided to the first switchback conveyance path SP1 and the second switchback conveyance path SP2.

"Staple binding finish mode"
In this mode, the image forming apparatus A forms an image of a series of documents from the first page to the nth page in the same manner as in the above-described mode, and carries it out from the main body discharge port 3 in a face-down state. Accordingly, the post-processing apparatus B retracts the buffer guide 26 of the sheet carry-in path P1 upward in FIG. 3 and moves the path switching piece 27 to the state of the solid line in FIG. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 25. Therefore, after the expected time that the leading edge of the sheet reaches the forward / reverse roller 30 of the stacking tray 29 based on the signal that the leading edge of the sheet is detected at the paper discharge port 25a, the transport controller 64a lowers the forward / reverse roller 30 from the upper standby position onto the tray. The forward / reverse roller 30 is rotated in the clockwise direction in FIG. Next, the conveyance control unit 64a drives the forward / reverse rotation roller 30 to rotate counterclockwise in FIG. 3 after the estimated time when the trailing edge of the sheet is carried onto the tray 29. Then, the sheet that has entered from the paper discharge outlet 25a is switched back and conveyed onto the stacking tray 29 along the first switchback conveyance path SP1. By repeating this sheet conveyance, a series of sheets are stacked on the stacking tray 29 in a face-down state.

  Each time the sheets are stacked on the stacking tray 29, the control CPU 61 operates the side aligning plate 34b to align the width direction position of the sheets to be stacked. Next, the control CPU 61 operates the end-face binding and stapling device 33 in response to a job end signal from the image forming apparatus A, and binds the trailing edge of the sheet bundle stacked on the tray. After this stapling operation, the control CPU 61 moves the rear end regulating member 32 that also serves as a bundle carrying-out means from the solid line position in FIG. 3 to the chain line position. Then, the staple-bound sheet bundle is carried out and stored on the first paper discharge tray 21. As a result, a series of sheets formed by the image forming apparatus A are stapled and stored in the first paper discharge tray 21.

[Sheet buffer operation to the first switchback conveying path SP1]
When continuously executing the above-described staple binding finishing process, the control CPU 61 temporarily holds subsequent sheets in the second switchback conveyance path SP2. The sheet buffer operation will be described. As described above, the transport roller 36 is disposed at the transport entrance of the second switchback transport path SP2, and the transport roller 36 is configured to be capable of forward and reverse rotation. Therefore, the control CPU 61 stacks sheets from the first switchback conveyance path SP1 onto the stacking tray 29, and causes the end-face binding and stapling device 33 to execute a binding process on the sheet bundle stacked on the tray after the image forming job is completed. After the binding process, the trailing edge regulating member 32 is moved to carry out the sheet bundle on the stacking tray 29 to the first paper discharge tray 21.

  Therefore, when the succeeding sheet is carried in from the image forming apparatus A during the staple binding operation and / or the sheet bundle carrying out operation to the sheet bundle on the stacking tray 29, the control CPU 61 detects this by the sheet sensor S1, After the expected time when the trailing edge of the sheet passes the path switching piece 27 of the sheet carry-in path P1, the paper discharge roller 25 is stopped. At the same time, the control CPU 61 moves the path switching piece 27 to the position shown in FIG. 10 and then rotates the paper discharge roller 25 in the reverse direction. Then, the sheet in the sheet carry-in path P1 is guided to the second switchback transport path SP2 and nipped by the transport roller 36. Next, the control CPU 61 stops the conveying roller 36 after the estimated time for the trailing edge of the sheet to reach the conveying roller 36 has elapsed. Then, the sheet in the sheet carry-in path P1 stays in the second switchback conveyance path SP2 and stops.

  Then, the control CPU 61 rotates the transport roller 36 in the clockwise direction in FIG. 10 at the timing when the sheet bundle on the stacking tray 29 is discharged to the first discharge tray 21, and simultaneously rotates the discharge roller 25 in the discharge direction. . Then, the sheet held in the second switchback conveyance path SP2 is guided to the first switchback conveyance path SP1 and is accumulated on the accumulation tray 29. Further, the control CPU 61 guides the sheet following the standby sheet from the carry-in entrance 23 to the paper discharge roller 25 and stacks it on the stacking tray 29.

  As described above, in the present invention, the first switchback conveyance path SP1 is provided on the downstream side and the second switchback conveyance path SP2 is provided on the upstream side of the substantially straight sheet conveyance path P1. A first processing unit (the above-described stacking tray) 29 is disposed in the first switchback transport path SP1, and a second processing unit (the above-described stacking guide) 35 is disposed in the second switchback transport path SP2. Therefore, the subsequent sheet sent to the sheet carry-in path P1 during the post-processing operation such as stapling in the first processing unit 29 located on the downstream side is temporarily held in the second switchback conveyance path SP2 on the upstream side, and the first After the processing operation of the processing unit 29 is completed, the subsequent sheet held in the second switchback conveyance path SP2 is transferred to the first switchback conveyance path SP1. At the same time, as described later, the present invention temporarily holds the subsequent sheet sent to the sheet carry-in path P1 during the post-processing operation in the second processing unit 35 of the second switchback transport path SP2 in the sheet carry-in path P1. It is characterized by that.

  As described above, when the second succeeding sheet is carried into the sheet carry-in path P1 during the post-processing operation in the first switchback conveyance path SP1, the conveyance control is performed as follows. In this case, as shown in FIG. 10, the paper discharge roller 25 is composed of a pair of pressure-contactable / separable rollers, and the roller pair is configured to be separable by an operating means (not shown) such as an electromagnetic solenoid. Therefore, the conveyance control means 64a holds the first sheet (SA1 in FIG. 11A) in the path of the second switchback conveyance path SP2 as before. In this state, when the second sheet (SA2 in FIG. 11A) is carried into the sheet carry-in path P1, the sheet discharge roller 25 is separated by a signal that the sheet leading edge is detected by the sheet sensor S1. Then, the transport roller 24 sends the second sheet SA2 to the paper discharge port 25a. Then, the second sheet SA2 overlaps the first sheet SA1 that has been waiting in the second switchback conveyance path SP2. This state is shown in FIG. 11A, and the first sheet SA1 and the second sheet SA2 overlap with each other at the leading end of the sheet having the illustrated offset amount ho. That is, the subsequent first sheet SA1 and second sheet SA2 are offset by a predetermined distance ho before and after in the transport direction. Accordingly, the conveyance control means 64a shifts the discharge rollers 25 to a state where they are pressed against each other (the state shown in FIG. 11A), and rotates in the discharge direction. Then, the two overlapped sheets are transferred to the stacking tray 29 from the first switchback transport path SP1.

  Further, according to the present invention, it is possible to temporarily wait for two or more subsequent sheets in the second switchback conveyance path SP2 described above. For example, a trouble such as a jam may occur in the post-processing of the preceding sheet bundle in the stacking tray 29. If two or more subsequent sheets remain in the upstream image forming apparatus A or the like, it is necessary to wait for two or more subsequent sheets in the second switchback transport path SP2. . In such a case, the conveyance control means 64a stacks the second sheet SA2 on the first sheet SA1 in the state shown in FIG. 12 in which the paper discharge roller 25 is separated as described above. Then, the sheet discharge roller 25 is pressed against the two sheets with a predetermined amount offset ho. Next, the conveyance control means 64a moves the path switching piece 27 to the position shown in FIG. 12 and rotationally drives the paper discharge roller 25 in the reverse direction (counterclockwise in FIG. 12). Then, the first and second sheets SA1 and SA2 are held in a scale shape in a state where the first and second sheets SA1 and SA2 overlap each other on the conveyance roller 36 of the second switchback conveyance path SP2. Next, after the post-processing operation of the first processing unit 29 is completed, the conveyance control unit 64a discharges a plurality of subsequent sheets waiting in the second switchback conveyance path SP2 in the discharge direction ( It is rotated in the clockwise direction in FIG. 12 and transferred to the first switchback transport path SP1 and loaded on the stacking tray 29.

  As described above, the first sheet SA1 waiting in the second switchback conveyance path SP2 and the second sheet SA2 from the sheet carry-in path P1 are offset by a predetermined amount ho, or a plurality of second sheets SA2 are moved to the second switchback conveyance path SP2. The reason why the first and second sheets SA1 and SA2 are offset by a predetermined amount ho in a scale shape is that the aligning means (the aforementioned caterpillar belt) 31 is used when the rear end regulating member 32 disposed on the stacking tray 29 is abutted and aligned. This is for sequentially abutting and aligning with the rear end regulating member 32 from the lowermost sheet. Therefore, the offset amount ho of the succeeding sheet is set to be larger than the distance z between the contact point where the caterpillar belt (aligning means) 31 contacts the sheet and the rear end regulating member 32 (ho> z). With such an operation, the staple processing can be continuously performed by the post-processing apparatus B without stopping the image forming apparatus A.

"Sheet fold finish mode"
In this mode, the image forming apparatus A forms an image on a sheet in the order described with reference to FIG. Therefore, the post-processing apparatus B retracts the buffer guide 26 of the sheet carry-in path P1 upward in FIG. 3, and moves the path switching piece 27 to the state of the solid line in FIG. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 25. Therefore, the control CPU 61 stops the paper discharge roller 25 at the timing when the trailing edge of the sheet passes the path switching piece 27 with reference to the signal detected by the sheet sensor S1, and at the same time, sets the path switching piece 27 to the position of the broken line in FIG. Moving. Then, the paper discharge roller 25 is reversely rotated (counterclockwise in FIG. 3). Then, the sheet that has entered the carry-in path P1 is reversed in the conveyance direction and is guided from the path switching piece 27 to the second switchback conveyance path SP2. Then, it is guided to the accumulation guide 35 by the conveying rollers 36 and 37 arranged in this path.

  The control CPU 61 moves the sheet leading edge regulating member 38 to the lowermost Sh1 position at the timing when the sheet is carried into the stacking guide 35 from the second switchback conveyance path SP2. Then, the entire sheet is supported by the accumulation guide 35. In this state, the control CPU 61 operates the side edge aligning member 39 to align the sheets in the width direction. (Note that this width-alignment alignment does not have to be performed on the first sheet, and does not have to be performed every time the sheet enters).

  Next, the control CPU 61 moves the front end regulating member 38 to a position Sh3 where the rear end of the sheet enters the switchback entry path 35a. Then, the rear end of the sheet supported by the guide 35 moves back to the switchback entry path 35a. In this state, the subsequent sheets are sent from the second switchback conveying path SP2 onto the stacking guide 35, and the subsequent sheets are stacked on the preceding sheet. Then, the leading edge regulating member 38 is moved from the Sh3 position to the Sh1 position in accordance with the carry-in of the subsequent sheet.

  Next, the sheet side edge aligning member 39 is operated in the same manner as described above, and the loaded sheet and the sheet supported on the guide are aligned and aligned. By repeating such an operation, the sheet on which the image is formed by the image forming apparatus A is aligned on the stacking guide 35 via the second switchback conveyance path SP2. Therefore, when receiving the job end signal, the control CPU 61 moves the leading edge regulating member 38 to the position Sh2, and sets the center of the sheet to the binding position X.

  Therefore, the control CPU 61 operates the saddle stitching stapling device 40 to staple one or more places in the center of the sheet. In response to this operation completion signal, the control CPU 61 moves the leading end regulating member 38 to the position Sh1, and positions and sets the center of the sheet at the folding position Y. Therefore, the sheet bundle is folded in the sequence shown in FIGS. 8A to 8D and the sheet bundle is carried out to the second paper discharge tray 22.

[Sheet Buffer Operation to Second Switchback Conveyance Path SP2]
When the above-described sheet bundle folding finishing process is continuously executed, the control CPU 61 temporarily holds subsequent sheets in the sheet carry-in path P1. This sheet buffer operation will be described. As described above, the buffer guide 26 is provided in the sheet carry-in path P1, and the buffer guide 26 locks the rear end of the sheet to the sheet standby portion (area) formed above the sheet carry-in path P1 as shown in FIG. It is comprised with the latching member to do.

  Therefore, when the above-described sheet bundle folding process is continuously performed, the control CPU 61 temporarily holds the subsequent sheet sent to the carry-in path in the buffer guide 26. The operation will be described. As described above, the sheets are stacked on the stacking guide 35 from the second switchback transport path SP2, and after the image forming job is finished, the sheet bundle stacked on the guide is bound by the saddle stitching staple device 40. Execute the process. Then, after the binding process, the folding blade 46 and the folding roll means 45 are operated to fold the sheet bundle on the stacking guide 35 into a booklet shape and carry it out to the second paper discharge tray 22.

  Therefore, when the succeeding sheet is loaded from the image forming apparatus A to the sheet bundle on the stacking guide 35 during the staple binding operation and / or the sheet bundle folding operation, the control CPU 61 detects this by the sheet sensor S1. After the expected time when the trailing edge of the sheet has passed through the buffer guide 26 in the sheet carry-in path P1, the paper discharge roller 25 is stopped. At the same time, the control CPU 61 moves the buffer guide 26 to the position shown in FIG. 11, and then rotates the paper discharge roller 25 in the reverse direction. Then, the sheet rear end of the sheet carry-in path P1 is guided to the buffer guide 26. Next, the control CPU 61 stops the paper discharge roller 35 after the estimated time for the trailing edge of the sheet to reach the buffer guide 26 has elapsed. Then, the sheet in the sheet carry-in path P <b> 1 stops with its rear end being locked by the buffer guide 26.

  Then, after the sheet bundle on the stacking guide 35 is discharged to the second sheet discharge tray 22, the control CPU 61 carries in the subsequent sheet from the image forming apparatus A, and at the timing when this sheet overlaps the staying (standby) sheet. The paper discharge roller 25 is rotated clockwise in FIG. 12, and at the same time, the buffer guide 26 is moved to the broken line position in FIG. Then, the vertically stacked sheets are sent to the downstream side by the paper discharge roller 25, and then guided to the second switchback transport path SP2 by the reverse rotation of the paper discharge roller 25. The upper and lower sheets are guided to the accumulation guide 35 and aligned in an up-and-down manner. The sheets subsequent to these stacked sheets are sequentially stacked and stored in the stacking guide 35 from the sheet carry-in path P1 and the second switchback transport path SP2 in the same manner as before. By such an operation, the sheet bundle folding process can be continuously performed by the post-processing apparatus B without stopping the image forming apparatus A. In the case of superimposing sheets, the paper discharge roller 25 is composed of a pair of rollers that can be pressed and separated as shown in FIG. When stacking sheets, the paper discharge roller 25 is separated by an operating means such as an electromagnetic solenoid.

[Continuous processing operations]
In the present invention, as described above, the first and second switchback transport paths SP1 and SP2 are arranged at a distance from each other in the sea and the carry-in path P1, and the first switchback transport path SP1 performs stapling processing. Since the tray 29 and the second switchback conveying path SP2 are provided with a stacking guide 35 for bundling sheets, if the staple binding finish and the bundling finish are consecutive in the front and back, the preceding post-processing is awaited. It is possible to execute subsequent post-processing. Further, even if a trouble such as a jam occurs during the execution of the preceding post-processing, it is possible to transport a sheet staying in the system for the subsequent post-processing to the subsequent processing position.

  In the present invention, the saddle stitching stapling device 40 is disposed at the binding position X on the stacking guide 35 described above. However, the sheet processing path is disposed in the order of the stacking guide, the binding position, and the folding position. The stacking guide unit, then the stapling device, and the sheet folding unit may be arranged downstream thereof. Furthermore, it is also possible to fold the sheet bundle and carry it out to the second paper discharge tray 22 without performing the binding process with this saddle stitching stapler.

1 is an overall explanatory diagram of an image forming system according to the present invention. 1 is an overall explanatory view of a post-processing apparatus provided with a sheet folding apparatus according to the present invention. Detailed explanatory drawing which shows a part of post-processing apparatus of FIG. FIG. 3 is a detailed explanatory diagram of a sheet folding apparatus incorporated in the post-processing apparatus of FIG. 2. FIG. 2 is an explanatory diagram showing an image forming order in the apparatus of FIG. 1. It is explanatory drawing of the folding roll means of FIG. 4, (a) is sectional structure, (b) is explanatory drawing of a sheet | seat width direction plane. (A) is explanatory drawing of the drive mechanism of folding roll means, (b) is explanatory drawing of the drive mechanism of folding blade, (c) is structure explanatory drawing of a one-way clutch. FIGS. 3A and 3B are explanatory diagrams of a sheet bundle folding operation in the apparatus of FIG. 2, wherein FIG. 3A is a state diagram in which the sheet bundle is positioned and set at a folding position, FIG. 2B is an initial state diagram of the sheet bundle folding operation; Is a state diagram in which the sheet bundle is inserted into the nip position of the folding roll means, and (d) is a carrying out state diagram in which the sheet bundle is folded by the folding roll means. Explanatory drawing of the control structure in the system of FIG. Explanatory drawing of the aspect which hold | maintains the sheet | seat which reaches a stacking tray temporarily in a 2nd switchback conveyance path. FIG. 10 shows the standby state of the succeeding sheet in FIG. 10, (a) is an explanatory diagram of the state where the first sheet reaches the standby position and the second sheet reaches the carry-in entrance, and (b) processes the first and second sheets. It is explanatory drawing of the state accommodated in the tray. Explanatory drawing of the aspect which hold | maintains the sheet | seat which reaches | stacks a stacking guide temporarily in a sheet | seat carrying-in path | route. FIG. 12 shows the standby state of the succeeding sheet in FIG. 12, (a) is an explanatory view of the state where the first sheet reaches the standby position and the second sheet reaches the carry-in entrance, and (b) is a stack of the first and second sheets. It is explanatory drawing of the state loaded on a guide.

Explanation of symbols

A image forming apparatus B post-processing apparatus P1 sheet carry-in path SP1 first switchback conveyance path SP2 second switchback conveyance path 21 first paper discharge tray 22 second paper discharge tray 23 carry-in port 24 carry-in roller 25 paper discharge roller 25a discharge Paper mouth 26 Buffer guide 27 Path switching piece 28 Post-processing unit 29 First stacking unit (stacking tray) (first processing unit)
30 Forward / reverse roller 31 Caterpillar belt 32 Rear end regulating member 33 Staple device 35 Second stacking unit (stacking guide) (second processing unit)
36 Conveying roller 37 Conveying roller 38 Front end regulating member 40 Saddle stitching staple device 45 Folding roll means 45a First folding roll 45b Second folding roll 45g Gap 45c Clutch means SA1 First sheet SA2 Second sheet

Claims (9)

This is a post-processing device that transfers sheets from the sheet carry-in port to different first and second post-processing units, and performs post-processing such as stapling and sheet folding on the sheets in the first and second post-processing units. And
A sheet carry-in path for sequentially transferring sheets supplied to the carry-in entrance to a predetermined paper discharge port;
A first post-processing unit that is disposed downstream of the sheet discharge path of the sheet carry-in path and performs post-processing on a sheet from the sheet discharge port;
A switchback conveyance path that branches from between the carry-in entrance and the discharge opening of the sheet carry-in path, reverses the sheet conveyance direction, and transfers the sheet to a position different from the sheet carry-in path;
A second post-processing section that is disposed downstream of the switchback conveyance path and that performs post-processing on the sheet; and a discharge roller means that is disposed at a discharge port of the sheet carry-in path;
Carry-in roller means arranged at the path entrance of the switchback conveying path;
A conveyance control means for controlling the paper discharge roller means and the carry-in roller means;
With
The conveyance control means temporarily waits the subsequent sheet supplied to the carry-in entrance during the post-processing operation in the first post-processing unit in the switchback conveyance path,
The discharge roller means and the carry-in roller means are controlled so as to transfer a succeeding sheet waiting in the switchback conveyance path to the first post-processing section after finishing the post-processing operation of the first post-processing section. Post-processing device to do. The transport control unit temporarily waits by superimposing a plurality of sheets sequentially supplied to the carry-in entrance during the post-processing operation in the first post-processing unit on the switchback transport path,
Controlling the discharge roller means and the carry-in roller means so that a plurality of subsequent sheets waiting in the switchback conveyance path after the completion of the post-processing operation of the first post-processing section are transferred to the first post-processing section. The post-processing apparatus according to claim 1, wherein The control means is configured to intermittently drive the carry-in roller means to offset the overlapping sheets by a predetermined amount forward and backward in the conveyance direction when a plurality of sheets are placed on standby in the switchback conveyance path. The post-processing apparatus according to claim 1 or 2. In the first post-processing section, sheet stacking means for stacking and storing sheets from the paper discharge port is disposed, and sheet end regulating means for butting and regulating the sheet end against the sheet stacking means, and the regulating means Aligning transport means for transporting the sheet is provided,
The control unit sets an offset amount when a plurality of sheets are offset to the switchback conveyance path by a predetermined amount so as to be longer than an interval between the sheet end regulating unit and the aligning conveyance unit. Item 4. The post-processing device according to item 3. The discharge roller means and the carry-in roller means are configured with an interval shorter than the length in the conveyance direction of at least the maximum size sheet,
The paper discharge roller means comprises a pair of rollers that can be pressed against and separated from each other,
The control unit superimposes the standby sheet waiting on the switchback conveyance path and the succeeding sheet supplied to the carry-in entrance with the discharge roller being separated, and then the first post-processing is performed by the discharge roller unit. The post-processing apparatus according to claim 1, wherein the post-processing apparatus is controlled so as to be transferred to a section. The first processing unit is arranged with a first sheet stacking unit that stacks and aligns the sheets from the discharge port,
Second sheet stacking means for stacking and aligning sheets from the switchback conveying path is disposed in the second processing section,
The first sheet stacking means includes end-face stitching staple means for binding the edges of the stacked sheets, and the second sheet stacking means includes saddle stitching staple means for binding the central portion of the stacked sheet bundle. The post-processing apparatus according to claim 1, wherein the post-processing apparatus is arranged. A sheet carry-in route having a carry-in entrance for sequentially carrying in sheets;
A first switchback conveyance path that branches off from the sheet carry-in path and reverses the sheet conveyance direction;
A second switchback conveyance path that branches from the sheet carry-in path upstream of the first switchback conveyance path and reverses the sheet conveyance direction;
A first sheet stacking means for stacking and stacking sheets in a bundle in a continuous manner with the first switchback conveying path;
A second sheet stacking means for stacking and stacking sheets in a bundle in a continuous manner with the second switchback conveying path;
End-face stitching staple means arranged in the first sheet stacking means and binding the edges of the stacked sheets;
Folding roll means arranged in the second sheet stacking means and folding the stacked sheets;
A discharge roller means disposed at a discharge port of the sheet carry-in path;
Carry-in roller means arranged at the path entrance of the switchback conveying path;
A conveyance control means for controlling the paper discharge roller means and the carry-in roller means;
With
The conveyance control unit temporarily waits the subsequent sheet supplied to the carry-in port during the binding operation of the end-face binding staple unit in the switchback conveyance path, and
The discharge roller means and the carry-in roller means are arranged so as to transfer a succeeding sheet waiting in the switchback conveyance path after the binding operation of the staple means from the first switchback conveyance path to the first sheet stacking means. A post-processing apparatus characterized by controlling. A sheet locking member for temporarily holding a sheet reaching the second switchback conveyance path is disposed on the upstream side of the second switchback conveyance path in the sheet carry-in path. Item 8. A post-processing apparatus according to Item 7. An image forming apparatus for sequentially forming images on sheets;
A post-processing device that performs post-processing such as stapling, stamping, and punching on the sheet from the image forming apparatus,
An image forming system comprising the post-processing apparatus having the configuration according to any one of claims 1 to 8.

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