JP2008213972A - Sheet post-processing device, and image forming device provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet post-processing device in which its mechanism is simple and the control is easy when stacking sheets to be successively conveyed in an offset manner by a predetermined amount. <P>SOLUTION: The sheet post-processing device comprises a sheet conveying path for conveying sheets to a predetermined processing position, a sheet binding means and/or a sheet folding means arranged at the processing position of the sheet conveying path, a sheet conveying means arranged on the sheet conveying path to convey the sheets on the processing position, and a control means for controlling the sheet conveying means. The sheet conveying means has a first conveying roller means arranged on the upstream side of the sheet conveying path, and a second conveying roller means arranged on the downstream side with a distance from the first conveying roller means. The first conveying roller means is constituted of a pair of rollers capable of releasing or reducing the roller pressure so as to be nipped while a succeeding sheet is superposed on a preceding sheet. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet post-processing apparatus that staples or folds a sheet conveyed from an image forming apparatus such as a copying machine or a printer at a predetermined fold position, and an image forming system including the sheet post-processing apparatus. The present invention relates to an improvement in a sheet stacking mechanism in which sheets are stacked in a state offset by a predetermined amount and bound or folded.

  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. This type of post-processing apparatus guides sheets from the image forming apparatus to a sheet stacking unit (processing tray or the like) as disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-133260, and aligns the bundle in a bundle shape with the stacking unit. Then, an apparatus configuration for folding the sheet bundle into a booklet shape is disclosed.

  Similarly, in Patent Document 2, the sheets from the image forming apparatus are switched back from the carry-in path and stacked on the processing tray, and the center of the sheet bundle is stapled and guided to the folding position on the downstream side of the tray. Has been disclosed that is folded into a booklet and accumulated in a storage stacker.

In this way, when aligning and stacking the sheet parts carried out from the image forming apparatus and performing the binding process or folding process, the sheet to be overlapped is offset (positioned) by a predetermined amount to form a heading part at the end of the booklet. It is known to perform so-called headline folding. For example, Patent Document 3 discloses a configuration in which a pair of offset rollers is provided on the tray and a sheet leading end abutting stopper is disposed on the downstream side of the tray when the sheets are aligned and stacked on the stacking tray. In addition, a mechanism is disclosed in which when the sheets are stacked on the processing tray, the stopper is moved downstream by a predetermined amount to be offset.
JP 2000-63031 A JP 2000-169028 A JP 2003-267622 A

  In a post-processing apparatus that performs a finishing process such as sheet binding or sheet folding by aligning sheets sequentially fed in a bundle as described above, the sheet is offset by a predetermined amount and a heading area (see FIG. 8E) In the prior art, for example, the offset mechanism disclosed in Patent Document 3 is known. When offsetting such a sheet by a predetermined amount, a stopper claw for locking the leading end of the sheet is provided upstream of the post-processing position, and the offset mechanism for moving the position of the stopper claw every time the sheet is carried out is complicated. There is a problem that the apparatus becomes large and the manufacturing cost becomes high.

  At the same time, when the leading end of the sheet is brought into contact with the stopper claw and locked, the thin paper sheet or the curled sheet may be bent at the leading end and damage the sheet such as a wrinkle. In addition, it is also known that such a sheet causes a paper jam (jam) with a stopper claw.

Accordingly, the main object of the present invention is to provide a sheet post-processing apparatus that has a simple mechanism and is easy to control when sheets sequentially carried out are offset and accumulated by a predetermined amount.
Further, according to the present invention, a sheet conveyed from an image forming apparatus or the like can be branched into a plurality of processing paths and selectively post-processed, and at the same time, the sheets aligned in a bundle can be found and folded. It is an object to provide a sheet post-processing apparatus and an image forming system.

  The present invention adopts the following configuration in order to solve the above problems. A sheet conveyance path that sequentially conveys the sheets supplied to the carry-in entrance to a predetermined processing position, a sheet binding unit and / or a sheet folding unit that are disposed at the processing position of the sheet conveyance path, and a sheet conveyance path. A sheet conveying unit configured to convey a sheet from the carry-in port to the processing position; and a control unit configured to control the sheet conveying unit. The sheet conveying means includes a first conveying roller means arranged on the upstream side of the sheet conveying path and a second conveying roller means arranged on the downstream side at a distance from the first conveying roller means. The first conveying roller means and the second conveying roller means are arranged at an interval shorter than the length in the sheet conveying direction, and the first conveying roller means is in a state in which the succeeding sheet is superimposed on the preceding sheet. A pair of rollers that can release or reduce the roller pressing force so as to nip the roller is configured, and the roller pair is drivingly connected so as to apply a conveying force to the subsequent sheet side.

  The control means includes the first conveyance roller means and the second conveyance roller means in a state where the preceding sheet sent from the carry-in entrance is temporarily stopped and held by the first conveyance roller means and the second conveyance roller means. The preceding sheet is conveyed so as to overlap the succeeding sheet from the carry-in entrance, and then the preceding sheet and the succeeding sheet are simultaneously offset by a predetermined amount downstream of the second conveying roller means, and then the second conveying roller means Then, control is performed so that all sheets to be aligned are overlapped in a state offset by a predetermined amount and conveyed to the processing position.

  The control means conveys the succeeding sheet to the nip position of the second conveying roller means in a state where the preceding sheet is held by the first conveying roller means and the second conveying roller means, and then the preceding sheet and the succeeding sheet are moved. At the same time, when the sheet is offset by a predetermined amount to the downstream side of the second conveying roller means, (1) the sheet is moved between the first conveying roller means and the second conveying roller means with the roller pressing force of the first conveying roller means applied. (2) The sheet is transferred by the second conveying roller means in a state where the roller pressure contact force of the first conveying roller means is released.

  When the control unit conveys the subsequent sheet to the nip position of the second conveyance roller unit while the preceding sheet is held by the first conveyance roller unit and the second conveyance roller unit, the roller of the first conveyance roller unit When the leading edge of the succeeding sheet hits the nip position of the second conveying roller unit, the roller pressing force is applied so as to prevent the sheet from rebounding.

  The roller pairs constituting the first conveying roller means can be selected in at least three stages: a separated state, a reduced state in which the mutual pressing force is reduced, and an added state in which the mutual pressing force is applied. And the control means positions the roller pair in a separated state when the subsequent sheet is nipped while holding the preceding sheet, and in a reduced state when the succeeding sheet is transferred to the second conveying roller means. Position.

  A sheet conveying path between the first conveying roller unit and the second conveying roller unit is formed to be curved so that the preceding sheet is positioned on the inner side of the curve and the subsequent sheet is positioned on the outer side of the curve.

A sheet carry-in path that is disposed substantially horizontally and has a sheet carry-in opening and a paper discharge opening, a paper discharge tray means disposed downstream of the sheet discharge opening in the sheet carry-in path, and a carry-in entrance of the sheet carry-in path A switchback path that branches from between the sheet discharge outlet and reverses the sheet conveyance direction from the carry-in opening and guides it to the downstream post-processing position, and a sheet binding means disposed at the post-processing position, and / or Or a sheet folding means, and the first conveying roller means is disposed adjacent to the sheet discharge port of the sheet carry-in path and the second conveying roller means is adjacent to the switchback path via the path switching means. The first conveying roller means and the second conveying roller means are configured at an interval shorter than the length in the sheet conveying direction. The first conveying roller means is composed of a pair of rollers capable of releasing or reducing the roller pressing force so as to nip the succeeding sheet on the preceding sheet, and the roller pair is conveyed to the succeeding sheet side. The first conveyance roller unit and the second conveyance roller unit are connected to each other so as to apply a force. In this state, the succeeding sheet from the carry-in entrance is superposed on the preceding sheet while being temporarily stopped and held.
Subsequently, the preceding sheet and the succeeding sheet are simultaneously conveyed by a predetermined amount to the downstream side of the second conveying roller unit, and thereafter, all the sheets to be aligned from the second conveying roller unit are overlaid in an offset state by a predetermined amount. Control is performed so as to convey to the processing position.

  Sheet folding means is disposed at the post-processing position, and the sheet folding means is configured to fold a sheet bundle offset by a predetermined amount in a scale shape from the center.

  An image forming apparatus that sequentially forms an image on a sheet, and a sheet post-processing apparatus that aligns the sheets from the image forming apparatus and folds them into a booklet. The sheet post-processing apparatus has the above-described configuration. An image forming system.

  In the present invention, a first conveyance roller unit and a second conveyance roller unit are arranged at intervals shorter than the length in the sheet conveyance direction on a sheet conveyance path for conveying a sheet to a post-processing position, and a preceding sheet is placed between the conveyance roller units. In the stopped state, the subsequent sheet is conveyed so as to be overlapped, and then the preceding sheet and the subsequent sheet are simultaneously offset by a predetermined amount downstream of the second conveying roller unit, and the subsequent sheets sequentially aligned are similarly offset. Then, all the sheets are conveyed to the processing position on the downstream side of the second conveying roller means.

  For example, a heading area can be formed by offsetting a plurality of sheets by a predetermined amount by controlling the rotation of a first roller pair and a second roller pair configured by a pair of rollers in pressure contact with each other. There is no need to provide a special offset mechanism such as a stopper claw for offsetting. Therefore, the offset mechanism can be simplified, and the apparatus can be provided in a small size and at a low cost.

  Further, by arranging the first conveying roller means and the second conveying roller means in the switchback path for reversing the conveying direction of the sheet from the carry-in port, the rear of the sheet is not affected by the length size of the sheet. It can always be offset at a fixed position with respect to the end. For this reason, it is not necessary to move the position of the first conveying roller means and the second conveying roller means according to the sheet size, and the offset mechanism can be simplified.

  Further, by arranging the first conveying roller means and the second conveying roller means in a curved path so that the preceding sheet is positioned on the inner side of the curve and the subsequent sheet is positioned on the outer side of the curve, the succeeding sheet is positioned on the downstream side. After the resist is corrected on the outer periphery of the roller of the second conveying roller means, the sheet is offset and conveyed simultaneously with the preceding sheet. Therefore, it is possible to overlap the sheets with an accurate offset amount without skewing.

  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. 3A 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.

  When double-sided printing and 2-in-1 printing are designated as image forming conditions and “sheet bundle folding mode” is set as post-processing, when the last page is n pages in image forming apparatus A 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 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 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 30 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 30 and a discharge port 25 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 25 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 25. Above the stacking tray 29, a forward / reverse roller 30a 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. 3A). A forward / reverse motor M2 is connected to the forward / reverse roller 30a and rotates clockwise when a sheet enters the stacking tray 29, and rotates counterclockwise 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 30 and one end pulley side are pressed against each other, and the tip pulley side is pivotally supported so as to hang from the stacking tray 29 around the pulley shaft. Reference numeral 30 b shown in the figure is a driven roller that engages with the forward / reverse rotation roller 30 a 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 outlet 25 enters the stacking tray 29 and is transported toward the first discharge tray 21 by the discharge roller 30, and the trailing edge of the sheet is transferred from the discharge outlet 25 onto the stacking tray 29. After entering, when the paper discharge roller (forward / reverse rotation 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 trailing edge of the sheet along the stacking tray 29 in cooperation with the forward / reverse roller 30a.

  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, and moves in the left-right direction along the 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.

  Further, the stacking tray 29 is provided with a side alignment plate 34b for aligning the width direction of the sheets stacked on the tray, and the side alignment plate 34b is arranged on the left and right sides (around FIG. 3A) 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 conveying path SP1 configured as described above aligns the sheets from the sheet discharge outlet 25 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 from the discharge tray 25 is not switched back and the sheet fed along the stacking tray 29 is discharged between the forward / reverse roller 30a and the driven roller 30b. 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. 3A, 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.

[Configuration of offset mechanism]
In the present invention, sheets sequentially fed to the above-described second switchback path SP2 (sheet conveyance path; the same applies hereinafter) are overlapped and stacked between the upstream discharge rollers 30 and the sheets are collected at this time. It is characterized by offset by a certain amount. For this reason, the discharge roller 30 located on the upstream side (first conveyance roller means; hereinafter the same) and the conveyance roller 36 located on the downstream side (offset roller; hereinafter referred to as “second conveyance roller means”) are as follows. Configure.

  The first conveying roller means 30 and the second conveying roller means 36 are arranged in the sheet conveying path SP2 as follows. (1) The first conveying roller means 30 and the second conveying roller means 36 are arranged at an interval (L1) shorter than the length in the sheet conveying direction. Accordingly, the sheet from the sheet carry-in path P1 is supported in a state straddling the first conveyance roller 30 and the second conveyance roller means 36. (2) The first conveying roller means 30 is composed of a pair of rollers in pressure contact with each other. The illustrated one includes the above-described paper discharge rollers 30a and 30b.

Therefore, as shown in FIGS. 3B (a) to 3 (d), the first transport roller means 30 is composed of a movable roller (forward / reverse roller) 30a and a fixed roller (driven roller) 30b, and the movable roller 30a is attached to the apparatus frame. The shaft is supported by a roller support lever 30L that is pivotally supported. 30x shown in the figure is a support shaft. The movable roller 30a is always pressed against the fixed roller 30b by a biasing spring 30S to the roller support lever 30L. A shift cam 30c is slidably disposed at the tip of the roller support lever 30L. The shift cam 30c adjusts the position of the roller support lever 30L in the following three states.
The first is a state in which the shift cam 30c is in contact with the roller support lever 30L at Cp1 (separated state). At this time, the movable roller 30a is pressed against the fixed roller 30b with the maximum tension of the biasing spring 30S. Second, when the shift cam 30c contacts the roller support lever 30L at Cp2 shown in the drawing, the movable roller 30a is pressed against the fixed roller 30b with a weak pressing force. Third, the cam surface is formed so that the movable roller 30a is separated from the fixed roller 30b when the shift cam 30C contacts the roller support lever 30L at Cp3 in the drawing. A stepping motor SM is connected to the shift cam 30c, and by adjusting the angular position of the motor, the movable roller 30a is pressed against the fixed roller 30b with a strong pressure contact force, and is separated with a weak pressure contact force. The position is controlled to the state.

  The operation of the first conveying roller means 30 configured as described above will be described with reference to FIG. 5B. The preceding sheet SA1 sent to the second switchback conveying path (sheet conveying path) SP2 is the first conveying roller means 30 and the second conveying roller. It is supported by the roller 36. When the next sheet SA2 following the preceding sheet SA1 in this state is sent from the carry-in entrance 23, the stepping motor SM shifts the movable roller 30a to a state in which it is separated from the fixed roller 30b (see FIG. 4A). Next, when the succeeding next sheet SA2 enters between the first conveying roller means 30, the stepping motor SM brings the movable roller 30a into contact with the fixed roller 30b with a weak pressure. At this time, the forward / reverse motor M2 of the first conveying roller means 30 transmits the driving rotational force to the movable roller 30a and does not transmit the driving rotational force to the fixed roller 30b. That is, the forward / reverse motor M2 is configured to selectively transmit driving to the fixed roller 30b and the movable roller 30a via the clutch CL.

  Accordingly, when driving is transmitted to the movable roller 30a, the succeeding sheet SA2 in contact with the roller is conveyed toward the downstream offset roller (conveying roller) 36, and the preceding sheet SA1 in contact with the fixed roller 30b is maintained in a stopped state. Next, when the succeeding sheet reaches the nip point of the offset roller 36, after correcting the registration, the offset roller 36 is rotated by a predetermined angle. At this time, control is performed so that the upstream sheet discharge roller 30 is separated or the sheet trailing edge is fed out in synchronization with the offset roller 36. By repeating such control, the sheets from the carry-in entrance 23 are aligned in a scale-like manner while straddling the first conveyance roller means 30 and the second conveyance roller means 36.

[Configuration of the second stacking unit]
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 is aligned and aligned by the sheet side edge alignment member 39 in a state where the front end regulating member 38 is positioned at the position 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 at 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 folding roll 45a and the second folding roll 45b connected to the roll drive motor M6 through the clutch means 45c, and at the same time, the roll is moved in the sheet feeding direction. It is configured to be freely rotatable.

  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 in a shape that enters the roll cap 45g.

  Accordingly, the illustrated ones are the friction coefficient ν1 between the first folding roll 45a, the second folding roll 45b and the sheet, the friction coefficient ν2 between the sheets, and the friction coefficient ν3 between the sheet and the folding blade 46. The relationship is set to “ν1> ν2> ν3”. 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 folding roll 45a and the second folding roll 45b are driven to rotate by the 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 folding roll 45a and the second folding roll 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, 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. 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. This post-processing mode is set to, for example, “print-out mode”, “staple binding finishing mode”, “sheet bundle finishing mode”, or the like. Further, the folding finishing mode is set to the leading folding mode and the half folding mode, and the present invention relates to the folding folding mode.
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 for the drive motors of the carry-in roller 24 and the discharge roller 30 in the sheet carry-in path P1, and receives a detection signal from the sheet sensor Se1 arranged 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 driving circuit for a roll driving motor M6 that drives and rotates the first folding roll 45a and the second folding roll 45b, and a driving circuit for 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. Accordingly, the post-processing apparatus B retracts the buffer guide 26 in the sheet carry-in path P1 upward in FIG. 3A, and moves the path switching piece 27 to the state of the solid line in FIG. 3A. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 30. Therefore, after the expected time that the leading edge of the sheet reaches the forward / reverse roller 30a of the stacking tray 29 based on the signal detected at the paper discharge port 25, the conveyance control unit 64a lowers the forward / reverse roller 30a from the upper standby position onto the tray. The forward / reverse roller 30a is rotated clockwise in FIG. 3A. Then, the sheet that has entered the stacking tray 29 is transported toward the first paper discharge tray 21 by the forward / reverse rotation roller 30a 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 in the sheet carry-in path P1 upward in FIG. 3A and moves the path switching piece 27 to the solid line state in FIG. 3A as in the previous mode. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 30. 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 at the paper discharge port 25, the transport controller 64a lowers the forward / reverse roller 30a from the upper standby position onto the tray. The forward / reverse roller 30a is rotated clockwise in FIG. 3A. Next, the conveyance control unit 64a drives the forward / reverse rotation roller 30a to rotate in the counterclockwise direction in FIG. 3A 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 port 25 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. 3A 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.

  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.

"Sheet fold finishing mode (for headline folding)"
In this mode, the image forming apparatus A forms an image on a sheet in the order described in accordance with, for example, FIG. At this time, when the headline folding is set, as described with reference to FIG. 3B, the sheets are aligned in a bundle shape between the discharge roller 30 and the conveyance roller 36 of the second switchback conveyance path SP2. This operation will be described with reference to FIGS.

  The sheet accumulation control unit 64b of the control CPU C61 described with reference to FIG. 9 sends the sheet to the sheet discharge roller 30 by the carry-in roller 24 when the sheet is carried into the sheet carry-in path P1. At this time, in the case of the first sheet SA1, the paper discharge rollers 30a and 30b are maintained in the strong pressure contact state and are rotated clockwise in FIG. 5B. Although this state is shown in FIG. 10A, the sheet sent to the sheet carry-in path P <b> 1 is transferred from the carry-in roller 24 to the paper discharge roller 30. Therefore, the control CPU 61 stops the paper discharge roller 30 at the timing when the sheet trailing edge passes through the path switching piece 27 with reference to the signal detected by the sheet sensor Se1. At the same time, the path switching piece 27 is moved to the broken line position in the figure. Then, the paper discharge roller 30 is reversely rotated (counterclockwise in FIG. 10). 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.

  At this time, the conveying roller (second conveying roller means) 36 in the second switchback path SP2 is placed in a stopped state, and the trailing edge of the sheet hits the stopped conveying roller 36 as shown in FIG. At this timing, the control CPU 61 stops the forward / reverse motor M2 of the paper discharge roller 30. Next, the control CPU 61 shifts the movable roller 30a of the paper discharge roller 30 to a strong pressure contact state, and moves the second transport roller means 36 and the paper discharge roller 30 in a preset offset amount in synchronization. Then, the trailing edge of the sheet stops in a state where it projects from the second conveying roller means 36 to the downstream side by the illustrated of1 (see FIG. 10C). Therefore, the control CPU 61 holds the preceding sheet SA1 across the second conveying roller means 36 and the paper discharge roller 30, and waits for the subsequent sheet to be carried in.

  Next, when the succeeding sheet SA2 is carried in from the carry-in entrance 23, the control CPU 61 separates the movable roller 30a of the paper discharge roller 30, and simultaneously moves the path switching piece 27 to the solid line state of FIG. Then, the succeeding sheet SA2 is sent by the carry-in roller 24 toward the sheet discharge roller 30, and is sent so as to overlap the preceding sheet SA1. At this time, the control CPU 61 turns the movable roller 30a of the paper discharge roller 30 into a weak pressure contact state at the timing when the trailing edge of the subsequent sheet SA2 passes the carry-in roller 24, and turns on the clutch of the movable roller 30a to turn on the subsequent sheet SA2. The sheet is transferred until the rear end passes through the path switching piece 27, and then the paper discharge roller 30 is stopped.

  Next, the control CPU 61 shifts the path switching piece 27 to the state shown in FIG. 11E, and then reverses (moves counterclockwise) the movable roller 30a of the paper discharge roller 30 so that only the subsequent sheet SA2 is transferred to the second transport roller means 36. send. At this time, the first conveying roller means 30 is in a weak pressure contact state, and the second conveying roller means 36 is in a stopped state. Accordingly, only the succeeding sheet SA2 is sent to the conveying roller 36, and the preceding sheet SA1 is placed in a stationary state by the fixed roller 30b and the second conveying roller means 36.

  Next, the control CPU 613 stops the drive motor M2 of the paper discharge roller 30 at the timing when the trailing edge of the succeeding sheet SA2 hits the stopped conveyance roller 36 as shown in FIG. Next, the control CPU 61 shifts the movable roller 30b of the paper discharge roller 30 to the strong pressure contact state, and moves the conveying roller means 36 and the paper discharge roller 30 in synchronization with a preset offset amount. Then, as shown in FIG. 11 (f), the succeeding sheet SA 2 is offset from the conveying roller means 36 so as to protrude downstream from the conveying roller means 36, and at this time, the preceding sheet SA 2 moves by an offset amount (of 1 + of 2).

  The control CPU 61 repeats the above-described operation (FIGS. 11D, 11E, and 11F) to accumulate a predetermined number of sheets between the sheet discharge roller 30 and the second conveying roller means 36 in a scale shape. This state is shown in FIG. In this way, after all sheets sent from the image forming apparatus A are offset by a predetermined amount and stacked and aligned, the control CPU 61 shifts the movable roller 30a of the paper discharge roller 30 to the strong pressure contact state, and this paper discharge The roller 30 and the second conveying roller means 36 are synchronized and transferred to the downstream side of the conveying roller 36.

  On the downstream side of the conveying roller means 36, a folding roll means 45 and a saddle stitching staple means 40 are prepared in the second processing section 35 described above. Therefore, the control CPU 61 transfers the sheet (bundle) accumulated on the second conveying roller means 36 to the second processing section 35, and performs the saddle stitching staple processing and the folding processing (see FIG. 12H).

“Sheet bundle folding finishing mode (1/2 folding)”
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. 3A, and moves the path switching piece 27 to the state of the solid line in FIG. 3A. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 30. Therefore, the control CPU 61 stops the paper discharge roller 30 at the timing when the sheet trailing edge passes the path switching piece 27 based on the signal detected by the sheet sensor Se1, and at the same time, the path switching piece 27 is set to the position of the broken line in FIG. 3A. Moving. Then, the paper discharge roller 30 is reversely rotated (counterclockwise in FIG. 3A). 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.

  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 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 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.

  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. FIGS. 3A and 3B are explanatory diagrams of a first conveying roller unit in the apparatus of FIG. 2, wherein FIG. 3A is a configuration diagram, FIG. 2B is an explanatory diagram of a pressure contact state of the roller, and FIG. , (D) is an explanatory diagram of the separated state of the rollers. 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. (A) thru | or (c) The operation | movement state figure of the paper discharge roller in the apparatus of FIG. 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, (d) is a carrying out state diagram in which the sheet bundle is folded by the folding roll means, and (e) is a sheet folding state diagram. Explanatory drawing of the control structure in the system of FIG. (A) thru | or (c) The sheet conveyance in the apparatus of FIG. (A) thru | or (c) The conveyance state of the succeeding sheet | seat in FIG. FIG. 3 is a state diagram of conveying a sheet bundle in the apparatus of FIG. 2, (g) is a state diagram in which a predetermined number of sheets are accumulated in a scale shape, and (h) is a case in which folding processing and stapling processing are performed on the sheet bundle. Illustration.

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 (sheet conveyance path)
21 first discharge tray 22 second discharge tray 23 carry-in port 24 carry-in roller 25 discharge port 26 buffer guide 27 path switching piece 29 first stacking unit (stacking tray)
30 Paper discharge roller (first transport roller means)
30a Forward / reverse roller (movable roller)
30b Follower roller (fixed roller)
30c Shift cam 31 Caterpillar belt 32 Rear end regulating member 33 Staple device 35 Second stacking unit (stacking guide)
36 Conveying roller (second conveying roller means) (offset roller)
37 Conveying roller 38 Tip regulating member 40 Saddle stapling device 45 Folding roll means 45a First folding roll 45b Second folding roll 45c Clutch means SA1 First sheet SA2 Second sheet

Claims (8)

A sheet conveyance path for sequentially conveying sheets supplied to the carry-in entrance to a predetermined processing position;
Sheet binding means and / or sheet folding means arranged at the processing position of the sheet conveying path;
A sheet conveying means arranged in the sheet conveying path to convey a sheet from the carry-in entrance to the processing position;
Control means for controlling the sheet conveying means,
The sheet conveying means includes a first conveying roller means arranged on the upstream side of the sheet conveying path and a second conveying roller means arranged on the downstream side at a distance from the first conveying roller means. And
The first conveying roller means and the second conveying roller means are arranged at an interval shorter than the length in the sheet conveying direction,
The first conveying roller means is composed of a pair of rollers capable of releasing or reducing the roller pressing force so as to nip the succeeding sheet on the preceding sheet, and the roller pair is conveyed to the succeeding sheet side. Drive coupled to give force,
The control means includes the first conveying roller means and the second conveying roller means.
The preceding sheet sent from the carry-in port is conveyed so that the subsequent sheet from the carry-in port is superimposed on the preceding sheet in a state where the preceding sheet is temporarily stopped and held by the first carrying roller unit and the second carrying roller unit,
Next, the preceding sheet and the succeeding sheet are simultaneously conveyed by a predetermined offset to the downstream side of the second conveying roller means,
After that, all the sheets to be aligned from the second conveying roller means are overlapped in a state offset by a predetermined amount and conveyed to the processing position,
A sheet post-processing apparatus characterized by controlling. The control means conveys the succeeding sheet to the nip position of the second conveying roller means in a state where the preceding sheet is held by the first conveying roller means and the second conveying roller means, and then the preceding sheet and the succeeding sheet are moved. At the same time, when the sheet is offset by a predetermined amount to the downstream side of the second conveying roller means, (1) the sheet is moved between the first conveying roller means and the second conveying roller means with the roller pressing force of the first conveying roller means applied. Or (2) a sheet post-processing apparatus according to claim 1, wherein the sheet is transferred by the second conveying roller means in a state where the roller pressing force of the first conveying roller means is released. . When the control unit conveys the subsequent sheet to the nip position of the second conveyance roller unit while the preceding sheet is held by the first conveyance roller unit and the second conveyance roller unit, the roller of the first conveyance roller unit Reduce or cancel the pressure contact force,
2. The sheet post-processing apparatus according to claim 1, wherein when the leading edge of the succeeding sheet hits the nip position of the second conveying roller means, a roller pressing force is applied so as to prevent the sheet from rebounding. The roller pairs constituting the first conveying roller means can be selected in at least three stages: a separated state, a reduced state in which the mutual pressing force is reduced, and an added state in which the mutual pressing force is applied. Configured,
The control means positions the roller pair in a separated state when the subsequent sheet is nipped while holding the preceding sheet, and in a reduced state when the succeeding sheet is transferred to the second conveying roller means. The sheet post-processing apparatus according to any one of claims 1 to 3. A sheet conveyance path between the first conveyance roller unit and the second conveyance roller unit is formed in a curved shape, and the preceding sheet is positioned on the curved inner side and the subsequent sheet is positioned on the curved outer side. The sheet post-processing apparatus according to any one of claims 1 to 4. A sheet carry-in path that is disposed substantially horizontally and has a sheet carry-in port and a paper discharge port;
A discharge tray means disposed on the downstream side of the discharge port of the sheet carry-in path;
A switchback path that branches from between the carry-in port and the paper discharge port of the sheet carry-in route, reverses the conveyance direction of the sheet from the carry-in port, and guides it to the downstream post-processing position;
Sheet binding means and / or sheet folding means arranged at the post-processing position;
With
The first conveying roller means is disposed adjacent to the sheet discharge port of the sheet carry-in path, and the second conveying roller means is disposed adjacent to the switchback path via the path switching means,
The first conveying roller means and the second conveying roller means are configured with an interval shorter than the length in the sheet conveying direction,
The first conveying roller means is composed of a pair of rollers capable of releasing or reducing the roller pressing force so as to nip the succeeding sheet on the preceding sheet, and the roller pair is conveyed to the succeeding sheet side. Drive coupled to give force,
The control means for the first conveying roller means and the second conveying roller means is:
The preceding sheet sent from the carry-in port is conveyed so that the subsequent sheet from the carry-in port is superimposed on the preceding sheet in a state where the preceding sheet is temporarily stopped and held by the first carrying roller unit and the second carrying roller unit,
Next, the preceding sheet and the succeeding sheet are simultaneously conveyed by a predetermined offset to the downstream side of the second conveying roller means,
After that, all the sheets to be aligned from the second conveying roller means are overlapped in a state offset by a predetermined amount and conveyed to the processing position,
A sheet post-processing apparatus characterized by controlling. Sheet folding means is disposed at the post-processing position,
The sheet post-processing apparatus according to claim 1, wherein the sheet folding unit is configured to fold a sheet bundle offset from the center by a predetermined amount in a scale shape. An image forming apparatus that sequentially forms images on a sheet;
A sheet post-processing device that aligns sheets from the image forming apparatus and folds them into a booklet;
An image forming system, wherein the sheet post-processing apparatus has the configuration according to any one of claims 1 to 7.

Images