JP5248785B2 - Post-processing apparatus and image forming system having the same - Google Patents

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.
JP 2000-63031 A JP 2000-169028 A JP 2004-269158 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.

  On the other hand, as in the above-mentioned Patent Document 3, the image forming apparatus empty sheet is distributed and conveyed to the first and second paths at the carry-in entrance, and the end-bound staple or sheet folding process is performed in each path. It becomes a curved path. For this reason, it is difficult to handle cardboard sheets such as color printing. Thus, in order to distribute from the carry-in entrance to the first and second paths, the path must be distorted in order to obtain a compact device configuration. In such a distorted apparatus configuration, it is difficult to smoothly convey a sheet having a relatively large paper thickness and a small friction coefficient, particularly a color printed sheet. Therefore, there arises a problem that the apparatus becomes large or sheet jam frequently occurs.

  Therefore, the present inventor can stably convey the sheet by carrying the sheet from the image forming apparatus into the apparatus from the linear carry-in path through the switchback conveyance path, and the first is separated from the carry-in path. The second switchback transport path is configured, and the idea is that each of the above problems can be solved by folding a staple mechanism or a paper folding mechanism in each switchback transport path.

  Accordingly, it is a main object of the present invention to provide a post-processing apparatus capable of performing stable processing by forming a compact and compact apparatus for stapling and folding sheets conveyed from an image forming apparatus or the like and performing sheet folding. It is said. Furthermore, the present invention enables continuous sheets to be carried into the apparatus for the post-processing of the other during the post-processing operation of one of the sheets continuously fed and stapled and folded. An object of the present invention is to provide a post-processing apparatus that can efficiently perform the post-processing.

The present invention adopts the following configuration in order to solve the above problems.
A post-processing apparatus that transports a sheet from a carry-in port to different first and second post-processing units and performs post-processing on the sheet by the first and second post-processing units, the carry-in port and a paper discharge port A substantially straight sheet carrying path arranged in the horizontal direction and a first carrying path arranged in the lower direction of the sheet carrying path by reversing the carrying direction of the sheet sent from the sheet discharge port of the sheet carrying path. A first switchback conveyance path that guides the stacking tray; a first post-processing section that is disposed at a position continuous with the first switchback conveyance path and that performs post-processing on the sheet; and the first switchback conveyance path. A second switchback conveyance path that diverges from the sheet carry-in path on the upstream side and reverses the conveyance direction of the sheet sent to the sheet discharge port, and a position that is continuous with the second switchback conveyance path. Second to post-process the sheet It comprises a post-processing unit.
The first and second switchback conveyance paths include a first switchback conveyance path on the downstream side of the sheet discharge path and a second switchback conveyance path on the upstream side of the sheet discharge path. In the sheet carry-in path, a sheet discharge port and a sheet discharge roller capable of rotating forward and backward from the sheet discharge port are disposed at a position where a step is formed above the first stacking tray . and the sheet discharge roller, after the the second switchback conveying path, carries the leading edge of the sheet fed from the inlet port from the discharge outlet above the first collecting tray, conveying the sheet The direction is reversed and the rear end portion of the sheet is disposed at a position where it is carried into the second switchback conveyance path.
At the same time, the second switchback path is disposed in a vertical direction that forms a space surrounding the stapling means disposed on the first stacking tray between the sheet carry-in path and the first switchback path. Consists of curved paths.

The sheet conveyance path is arranged in Ryakusui horizontal direction, the second switchback conveying path is disposed Ryakunamari straight direction.

The first post-processing unit includes a first stacking tray that stacks and supports sheets sent from the first switchback conveyance path, and a stapling unit that binds and processes the sheets supported by the first stacking tray. And a paper discharge tray disposed downstream of the first stacking tray, and the paper discharge tray is guided to the first switchback transport path and the second switchback transport path. The front end of the sheet is configured to be supported.

The second post-processing unit includes a second stacking tray for stacking and stacking sheets fed from the second switchback conveyance path, and a folding process for folding the sheets supported by the second stacking tray. Means .

  In the second switchback conveyance path, a sheet conveyance roller capable of forward and reverse rotation that temporarily holds the sheet reaching the first sheet stacking unit located on the downstream side of the sheet carry-in path in the switchback conveyance path. Place.

  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.

The sheet carry-in path is configured to guide the sheet from the carry-in entrance to the first or second switchback conveyance path and to guide the sheet from the carry-in entrance to the outside of the apparatus.

  Consists of 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. Image forming system.

  According to the present invention, a first switchback conveyance path is provided on the downstream side of the sheet carry-in path, a second switchback conveyance path is provided on the upstream side, and the first sheet stacking is provided on the first switchback conveyance path. The sheet is aligned and accumulated by the means, stapled and processed, and the sheet is folded by the sheet accumulating means provided in the second switchback conveyance path.

  Since the sheet guided from the sheet carry-in path to the first and second switchback transport paths is transported along a path that is relatively straight, even a thick paper sheet or a sheet having a small friction coefficient can be reliably and stably transported. Is possible. Therefore, no conveyance traces such as wrinkles and image rubbing remain on the sheet.

  The sheets from the image forming apparatus are guided to the first sheet stacking unit from the first switchback conveying path for the sheets to be stapled, and the second sheet stacking is performed from the second switchback conveying path to the sheets to be folded. Since it is guided by the means, subsequent sheets having different finishing processes can be carried into the apparatus even during the processing operation of the preceding sheet, and continuous sheet processing can be processed efficiently at high speed. In particular, for example, even if a failure such as a jam occurs in the preceding sheet processing, the succeeding sheet can be carried into the apparatus without being stopped, and the jam processing can be performed at an optimal timing.

  Further, since the first switchback conveyance path for finishing staple binding is disposed on the downstream side of the sheet carry-in path, and the second switchback conveyance path for finishing sheet folding is disposed on the upstream side, the sheet folding mechanism or the saddle stitching stapler is provided. The second switchback conveyance path to be arranged can be arranged in the central part of the apparatus, and the apparatus can be made compact and small.

  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 a first stacking unit (first sheet stacking unit; the same applies hereinafter) 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 main body discharge port 3. Then, the post-processing apparatus B, which will be described later, stores the sheet into the second stacking unit (second sheet stacking means; the same applies hereinafter) 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 B 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 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 paper discharge roller 25 and one pulley side are pressed against each other, and the tip pulley side is pivotally supported so as to hang 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 discharge port 25a enters the stacking tray 29 and is transferred toward the first discharge tray 21 by the forward / reverse rotation roller 30, and the rear end of the sheet is transferred from the discharge port 25a to the stacking tray 29. After entering, when the forward / reverse roller 30 is rotated backward (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 32a for holding the sheet bundle and a rear end regulating surface 32b for regulating the rear end of the sheet against the sheet bundle. 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) 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 leading edge regulating member 38 is positioned at the position Sh3, and the sheet side edge is aligned with the sheet side edge aligning member 39 while the entire sheet is supported by the stacking 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. Therefore, an alignment motor M5 (not shown) is connected to the sheet side edge alignment member 39.

[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 FIGS. 6 (a) and 6 (b), 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 width direction. The gap 45g is arranged so as to coincide with the unevenness of the folding blade 46 described later, and consideration is given so that the front end 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, and the staple binding portion of the sheet and the folding blade 46 similarly formed in the concavo-convex shape in this gap. 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 FIGS. 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 drive rotation of the roll drive motor M6 is turned on and off to the first folding roll 45a and the second folding roll 45b. Configure as you can.

  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 drive motor M7 between a standby position retracted from the sheet bundle supported by the stacking guide 35 and a nip position between the pressure 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 its tip is formed in an uneven surface as shown in FIG. As described above, the blade tip is formed in a shape that enters the cap 45g of the rolls 45a and 45b.

  Therefore, in the figure, the relationship between the friction coefficient ν1 between the 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 “ν1> ν2> ν3”. It is set to the relationship. Accordingly, when 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 the folding roll. The means 45, the sheet bundle and the folding blade 46 are each applied as equal force. 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 reciprocate between a standby position retracted from the sheet supported by the stacking guide 35 and a nip position 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.

  Therefore, when the blade drive motor M7 rotates forward and backward, the folding blade 46 reciprocates between the standby position and the nip position 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 based on the solstice (d) of FIG. 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 64d described later; the same applies hereinafter) turns off the clutch means 45c. In the illustrated one-way clutch configuration, the roll drive motor M6 is stopped or 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.

  Therefore, the drive control means 64d moves the folding blade 46 from the standby position toward the nip position 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 toward the standby position in parallel with the feeding of the sheet bundle by the folding roll means 45 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 in contact with the roll surface is not drawn between the rolls by the rotating rolls 45a and 45b. That is, since the folding roll means 45 follows (follows) the inserted sheet (rotates) and rotates, only the sheet in contact with the roll will not be wound first. Further, since the folding roll means 45 follows and rotates following the inserted sheet, 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 sheet conveyance control unit 64a that performs conveyance of the sheet sent to the carry-in entrance 23, a sheet accumulation operation control unit 64b that performs sheet accumulation operation, and a sheet binding operation that performs sheet binding processing. A control unit 64c and a sheet folding operation control unit 64d for performing a sheet folding operation are provided.

  The sheet conveyance control unit 64a is connected to the control circuit of the driving motor M1 of the conveyance roller 24 and the discharge roller 25 of the sheet conveyance path P1 and receives a detection signal from the sheet sensor S1 disposed in this path. It is configured as follows. Further, the sheet stacking operation control unit 64b is configured to drive the forward / reverse rotation motor M2 of the forward / reverse rotation roller 30 and the discharge motor M3 of the trailing end regulating member in order to stack sheets on the first stacking unit (stacking tray) 29. It is connected to. Further, the sheet 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 surface binding stapling device 33 and the second stacking unit (stacking guide) 35 of the first stacking unit 29. ing.

  The sheet folding operation control unit 64d is connected to a drive circuit for a roll drive motor RM that drives and rotates the first and second folding rolls 45a and 45b and a drive circuit for the clutch means 45c. The control unit 64d is connected to a control circuit of a shift unit MS that controls the movement of the conveyance rollers 36 and 37 of the second switchback conveyance path SP2 and the tip regulation unit 38 of the accumulation guide 35 to predetermined positions. It is wired so that a detection signal may be received from the sheet sensor arranged in the.

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 detected by the sheet discharge port 25a, the sheet conveyance control unit 64a moves the forward / reverse roller 30 from the upper standby position onto the tray. Then, the forward / reverse roller 30 is rotated clockwise 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. In this way, the subsequent sheets are sequentially carried out to the paper discharge tray and stacked 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 detected by the sheet discharge port 25a, the sheet conveyance control unit 64a moves the forward / reverse roller 30 from the upper standby position onto the tray. Then, the forward / reverse roller 30 is rotated clockwise in FIG. Next, the sheet 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 stacking 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 to bind the trailing edge of the sheet bundle accumulated on the tray 29. 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 in the first 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 stitching and stapling device 33 to execute a binding process on the sheet bundle stacked on the stacking tray after the end of the image forming job. 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. In this case, as shown in FIG. 10, the discharge roller 25 is composed of a pair of rollers that can be pressed and separated from each other, and the subsequent sheet from the carry-in entrance 23 is overlapped simultaneously with the standby sheet on the discharge roller 25. In this case, the paper discharge roller 25 is preferably separated by an operating means such as an electromagnetic solenoid. 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 sheet 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.

  At the timing when the sheet is carried into the stacking guide 35 from the second switchback conveyance path SP2, the control CPU 61 moves the leading end regulating member 38 to the lowermost Sh1 position. Then, the entire sheet is supported by the accumulation guide 35. In this state, the control CPU 61 operates the above-mentioned sheet side edge aligning member 39 to align the sheets by width alignment. (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 accumulation guide 35 moves backward 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 stacking 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. The 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 is formed in the sheet standby portion (area) formed above the sheet carry-in path P1 as shown in FIG. ) To the rear end of the seat.

  Therefore, when the above-described sheet bundle folding process is continuously performed, the control CPU 61 temporarily holds the subsequent sheet sent to the sheet carry-in path P1 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. 11, 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 stacking the sheets, as shown in FIG. 11, the sheet discharge roller 25 is composed of a pair of rollers that can be pressed and separated from each other. When the sheets are overlapped, it is preferable that 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 in the sheet carry-in path P1 with a vertical distance therebetween, and the stacking tray 29 for stapling the first switchback transport path SP1. Since the stacking guide 35 for bundling sheets is arranged in the second switchback conveyance path SP2, when the staple binding finish and the bundling finish are consecutive in the front and rear, the subsequent without waiting for the preceding post-processing. Post processing can be executed. 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.

  Further, as shown by a broken line in FIG. 1, it is also possible to provide a third paper discharge tray 21b and to carry out the sheet carried into the sheet carry-in path P1 to the third paper discharge tray 21b. With this configuration, the sheet can be carried out to a position different from the first and second switchback paths, for example, outside the apparatus.

  Further, in the above-described apparatus, the end-face stitching stapling device 33 and the saddle stitching device for binding the edge of the sheet in the space surrounded by the sheet carry-in path P1, the first switchback transport path SP1, and the second switchback transport path SP2. The stapling device 40 is arranged vertically. This makes the device compact.

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. 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.

Explanation of symbols

A Image forming 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 Paper discharge port 26 Buffer Guide 27 Path switching piece 28 Post-processing unit 29 First stacking unit (stacking tray) (first sheet stacking means)
30 Forward / Reverse Roller 31 Caterpillar Belt 32 Rear End Restricting Member 33 End Binding Stapling Device 34 Side Alignment Plate 35 Second Stacking Unit (Stacking Guide) (Second Sheet Stacking Unit)
36 Conveying roller 37 Conveying roller 38 End regulating member 40 Saddle stitching staple device 45 Folding roll means 45a First folding roll 45ax Rotating shaft 45b Second folding roll 45bx Rotating shaft 45g Gap 45c Clutch means

Claims (8)

A post-processing apparatus that transfers sheets from a carry-in port to different first and second post-processing units, and performs post-processing on the sheets in the first and second post-processing units,
A substantially straight sheet carry-in path arranged in a horizontal direction having a carry-in port and a paper discharge port;
A first switchback conveyance path that reverses the conveyance direction of the sheet sent from the sheet discharge port of the sheet carry-in path and guides it to a first stacking tray disposed below the sheet carry-in path;
A first post-processing section that is disposed at a position continuous with the first switchback conveyance path and performs post-processing on the sheet;
A second switchback conveyance path that branches upstream from the sheet carry-in path upstream from the first switchback conveyance path and reverses the conveyance direction of the sheet sent to the paper discharge port;
A second post-processing unit that is disposed at a position continuous with the second switchback conveyance path and performs post-processing on the sheet;
With
The first and second switchback transport paths are
A first switchback conveyance path is provided downstream of the sheet discharge path of the sheet carry-in path.
A second switchback transport path is disposed upstream of the discharge port;
In the sheet carry-in path, a paper discharge opening and a paper discharge roller capable of moving forward and backward from the paper discharge opening are arranged at a position where a step is formed above the first stacking tray.
The paper discharge roller and the second switchback transport path are:
After the leading edge of the sheet sent from the carry-in port is carried out from the paper discharge port to the upper side of the first stacking tray, the sheet conveyance direction is reversed and the trailing edge of the sheet is conveyed to the second switchback. Placed in the position to carry into the road,
With this,
The second switchback path is a curved path disposed in a vertical direction that forms a space surrounding the staple unit disposed in the first stacking tray between the sheet carry-in path and the first switchback path. A post-processing device comprising: The post-processing apparatus according to claim 1, wherein the sheet carry-in path is arranged in a substantially horizontal direction, and the second switchback conveyance path is arranged in a substantially vertical direction. The first post-processing unit includes:
A first stacking tray for stacking and supporting sheets sent from the first switchback conveyance path;
Stapling means for binding the sheets supported on the first stacking tray;
A paper discharge tray disposed downstream of the first stacking tray;
Consists of
The paper discharge tray according to claim 1 or 2, characterized in that it is configured to support the leading end of the sheet guided by said first switchback conveying path and the second switchback conveying path Post-processing equipment. The second post-processing unit includes:
A second stacking tray for stacking and stacking sheets fed from the second switchback transport path;
Folding processing means for folding the sheet supported by the second stacking tray;
The post-processing apparatus according to claim 3 , comprising: In the second switchback conveyance path, a sheet that reaches the first sheet stacking means located on the downstream side of the sheet carry-in path is temporarily held in the second switchback conveyance path and can be rotated forward and backward. The post-processing apparatus according to any one of claims 1 to 4, wherein a sheet conveyance roller is disposed. 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 6. The post-processing apparatus according to any one of Items 1 to 5 . The sheet carry-in path is configured to guide the sheet from the carry-in entrance to the first or second switchback carrying path and to guide the sheet from the carry-in entrance to the outside of the apparatus. The post-processing apparatus according to any one of claims 1 to 6 . 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,
Imaging system the post-processing apparatus, characterized in that it comprises a structure according to any one of claims 1 to 7.

Images