JP4942533B2 - Image forming system - Google Patents

Description

  The present invention relates to a post-processing system that performs post-processing such as bookbinding, stamping, and sheet folding on a sheet carried out from an image forming apparatus such as a copying machine or a printer. A punch unit is attached to the post-processing apparatus. The present invention relates to an improvement of a unit configuration in which a punch unit is small and compact and can be easily attached in a system capable of punching filing holes in a sheet to be post-processed.

  2. Description of the Related Art Generally, a post-processing device that is attached to an image forming apparatus and sorts and stores image-formed sheets in a paper discharge tray or a post-processing device that aligns sheets in a bundle and staples them is widely known. Recently, a bookbinding apparatus that aligns sheets from an image forming apparatus in a bundle shape and binds them in a stack or a folding apparatus that performs filing folds has been widely used as a post-processing apparatus. Therefore, a punching device (puncher unit) that punches filing punch holes in a sheet that is attached to such a post-processing device and is sequentially fed is also known.

  For example, Patent Document 1 discloses a post-processing device that is connected to a paper discharge port of an image forming apparatus, and that collects and stacks sheets on which an image has been formed, and binds and binds with a stapling apparatus. FIG. 1 discloses a configuration in which a punch mechanism is built in the sheet carry-in path, and FIG. 2 discloses a configuration in which the punch device is connected between the post-processing apparatus and the image forming apparatus.

  As described above, conventionally, a post-processing device for post-processing an image-formed sheet has a built-in punch mechanism for punching filing holes, or a punch mechanism is arranged in a housing separated from the post-processing device to form an image. A layout is employed between the forming apparatus and the forming apparatus. As a punching mechanism, a sheet conveyance guide is provided with a punch member that can move up and down in a direction perpendicular to the sheet conveyance guide, and the punch member is moved up and down by a cam member connected to a drive motor to pass over the conveyance guide. Punch holes are drilled at predetermined positions.

  For this reason, the punch mechanism is composed of a punch member, a transport roller (transport mechanism) for setting a sheet at a predetermined punch position, a sheet sensor for controlling the transport roller, a waste box for storing punch scraps, and the like. Has been. As a punch member in this case, there are known a mechanism for perforating a sheet from an image forming apparatus temporarily and a mechanism for perforating a sheet moving at a predetermined speed.

  A case where a conventional post-processing apparatus incorporates a punch mechanism will be described with reference to FIG. 1 of Patent Document 1. A sheet carry-in path connected to a sheet discharge port of the image forming apparatus is provided, and a roller for controlling sheet conveyance is provided at the path entrance. A sensor (not disclosed in Document 1) for detecting the leading edge or trailing edge of the sheet is disposed. A punch member is arranged on the downstream side of the roller and sensor in a direction perpendicular to the conveying sheet so as to be movable up and down, and the punch member is moved up and down by a cam member connected to a drive motor. These punch mechanisms are each incorporated in the housing of the post-processing apparatus, and are configured to be driven and controlled by a power supply circuit and a control circuit prepared in the apparatus.

Therefore, depending on the apparatus specifications of the post-processing apparatus, a method in which a punch mechanism is provided and an apparatus that does not include the punch mechanism are individually produced in a factory or the like. Therefore, it is required to attach a punch mechanism as an option to the post-processing apparatus. Patent Document 1 discloses a configuration in which an optional device (punch unit) having a built-in punch mechanism is provided between the image forming apparatus and the post-processing apparatus in FIG. The punch unit includes a casing, a transport roller disposed in the casing, a punch member, and a sheet sensor (not disclosed in the publication). The punch unit has a function of independently conveying the sheet, a function of stopping the sheet at a predetermined position, and a function of punching punch holes in the stopped sheet.
JP 2003-128306 A

  As described above, when a punch unit for punching a filing hole is attached to a post-processing apparatus that performs post-processing such as bookbinding and folding on a sheet carried out from the image forming apparatus, a conventional punch mechanism is used for the post-processing apparatus. Built in the housing. In such an apparatus configuration, it is difficult to attach a punch mechanism as an option according to the usage environment and needs, and there is a problem that an apparatus that does not require (does not incorporate) the punch mechanism is large and requires a large installation space.

  Therefore, a unit housing different from these apparatus housings is provided between the image forming apparatus and the post-processing apparatus as in the apparatus disclosed in FIG. 2 of the aforementioned Patent Document 1, and a punch mechanism is provided in the unit housing. It has been proposed to do. The unit disclosed in FIG. 2 simply includes a punch mechanism between the image forming apparatus and the post-processing apparatus, a control mechanism for controlling the punch mechanism, and a mechanism for controlling the conveyance of the sheet to the punch position. Since it is built-in, there is a problem that the new structure is large and requires installation space, and the manufacturing cost increases.

  In particular, the sheet discharge roller of the image forming apparatus is disposed upstream of the sheet to be punched, and the carry-in roller of the post-processing apparatus is disposed downstream of the sheet. Even during conveyance, the sheet must be conveyed normally in synchronization with the front and rear rollers (the discharge roller and the carry-in roller). Therefore, the control is complicated, and when the carry-out speed varies depending on the sheet image forming conditions (for example, monochrome printing and color printing), the control of the conveyance roller of the punch unit is complicated and it is difficult to perform an accurate operation.

  Therefore, the present inventor arranges a punch mechanism for punching a filing hole in a sheet, a sheet transport system and a control circuit are arranged in a post-processing device (unit), and a hole punching mechanism is arranged in a punch unit so that the mechanism is simple. The idea was that it would be compact and compact, and at the same time it would be easier to control sheet transport.

  The present invention provides a post-processing system in which a punch unit having a punch mechanism can be easily attached to a post-processing apparatus, and an apparatus having a punch mechanism and an apparatus not having the punch mechanism can be easily configured as options. Providing is the main challenge. Another object of the present invention is to provide a post-processing system that can be securely installed without requiring an installation space when the punch unit is attached, and without requiring an installation space.

The present invention adopts the following configuration in order to solve the above problems. An image forming apparatus that forms an image on a sheet and a post-processing apparatus that performs post-processing on the image-formed sheet. The post-processing apparatus is arranged to be continuous with the sheet carry-in path and the sheet carry-in path, A punch unit that punches punch holes in a sheet sent to the sheet carry-in path, a tray unit that collects and stacks sheets from the sheet carry-in path, and a binding process and / or a folding process on a sheet bundle stacked in the tray unit Post-processing means for performing processing, processing operation control means for controlling post-processing operation by the post-processing means, and a first apparatus frame equipped with the sheet carry-in path, tray means, and post-processing means.

The punch unit includes a carry-in port for carrying in the sheet sent from the image forming apparatus , a sheet guide for transferring the sheet from the carry-in port to the sheet carry-in path, and punching processing on the sheet on the sheet guide. A punch member to be applied; punch driving means for moving the punch member up and down ; the sheet guide; and a second apparatus frame equipped with the punch member and punch driving means. The second device frame is composed of a member separated from the first device frame, and the first device frame has a carry-in port of the second device frame protruding toward the image forming apparatus. A pedestal support portion is provided for mounting and supporting the second device frame, and the pedestal support portion supports the impact force of the punch member in a state in which a part of the second device frame protrudes outward. Configure as follows.

The first apparatus frame includes conveyance roller means for nipping and conveying the sheet downstream of the sheet guide of the second apparatus frame, and the conveyance roller means is constituted by a roller capable of rotating in the forward and reverse directions. the guide, arranged a stopper means for restricting abut the trailing edge of the sheet, the sheet sensor for detecting the sheet rear end. And said processing operation control means reverses the conveying roller unit on the basis of the sheet trailing edge detection signal from the sheet sensor, drives and controls the punch drive means of the sheet trailing end while restricting abutted on the stopper means Configure as follows. As a result, the sheet can be positioned and set at an accurate punching position without using a special aligning mechanism.

  The sheet guide is composed of a pair of upper and lower guide plate members arranged at a predetermined interval, and a punch member is arranged on the upper guide plate member so as to move up and down between a top dead center and a bottom dead center. Further, the lower guide plate member is provided with a blade receiving hole that matches the punch member.

The sheet carry-in path is arranged in a substantially horizontal direction on the first apparatus frame, and the tray means branches from the sheet carry-in path and is arranged in a switchback path curved downward.

  The present invention comprises a housing member in which the (first) device frame of the post-processing unit and the (second) device frame of the punch unit are separated, and the second device frame is detachably attached to the first device frame. The first apparatus frame is provided with conveying roller means for nipping and conveying the sheet in the sheet carry-in path, and the second apparatus frame is provided with a sheet sensor for detecting the trailing edge of the sheet at the sheet carry-in entrance. Deploy. The punch driving means disposed in the second apparatus frame is electrically connected to receive power supply and drive control signals from the processing operation control means of the first apparatus frame, and the processing operation control means The conveying roller means is stopped based on the end detection signal, and the punch member is driven to punch the sheet while the sheet is nipped, and then the punched sheet is transferred to the sheet stacking means by the conveying roller means. Since it is configured, the following effects are produced.

  The punch unit is not equipped with a transport unit that transports a sheet and sets it at the punch hole position and its control unit. Therefore, when the punch unit is configured as an optional device, the configuration is simple, small and compact. At the same time, the space in the transport direction can be reduced and the space can be saved.

  Further, since the sheet guide disposed in the punch unit can be used as a die plate having a blade receiving hole for punching the sheet in cooperation with the punch member, the number of parts can be reduced and the structure can be reduced in size and cost.

  Further, the conveying roller means for stationaryly setting the sheet at the punch hole forming position is arranged on the post-processing unit side and configured to punch the rear end of the sheet. The sheet is synchronized with the sheet discharge roller of the image forming apparatus. Therefore, the image forming apparatus can perform image formation of the subsequent sheet during the punching operation.

  Further, since the second apparatus frame equipped with the punch unit is fixedly installed on the first apparatus frame of the post-processing unit, the apparatus can be firmly supported without requiring an independent installation mechanism.

  Further, the conveying roller means on the post-processing unit side is configured to be capable of forward and reverse rotation, and stopper means (such as a step wall) for restricting the rear end of the sheet against the sheet guide on the punch unit side are arranged, thereby It is possible to set the sheet at an accurate punching position by the control, and the effect is that the configuration becomes simple and the like.

  The present invention will be described in detail below based on the preferred embodiments shown in the drawings. FIG. 1 shows the 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 unit, and FIG. 3 is an explanatory diagram showing the configuration of a punch unit. FIG. 4 is an explanatory diagram showing a detailed configuration of the sheet folding unit.

  The image forming system shown in FIG. 1 includes an image forming unit A, a post-processing unit B, and a punch unit C. Further, a sheet folding device D is incorporated in the post-processing unit B. This will be sequentially described below.

[Configuration of image forming unit]
The image forming unit 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). This image data is digitally processed by the image processing unit, for example, and then transferred to the data storage unit 17 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 unit 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 printing conditions such as enlargement / reduction printing designation are set. The control unit is provided with a data storage unit 17 for accumulating image data read by the scan unit 13 or image data transferred from an external network. Then, image data for each page for image formation is transferred from the data storage unit 17 to the buffer memory 19, and a data signal is sent from the buffer memory 19 to the laser emitter 5.

  In the illustrated apparatus, post-processing conditions are also input and specified from the control panel 18 at the same time as image forming conditions. As the image forming conditions, a printing format such as “color / monochrome” and “single-sided / double-sided printing” and a printing format such as “enlargement / reduction” and “2 in 1” are designated. Further, the post-processing conditions are configured to set, for example, “print-out mode”, “staple binding mode”, “sheet bundle folding mode”, “punch processing mode”, and the like according to post-processing means of a post-processing apparatus to be described later.

[Configuration of post-processing unit]
A post-processing unit B is connected to the main body discharge port 3 of the image forming unit A described above. The post-processing unit B receives a sheet on which an image has been formed from the main body discharge port 3 of the image forming unit A, and (1) whether to store the sheet in the first discharge tray 21 (a “print-out mode” described later) (2) Sheets from the main body discharge port 3 are aligned in a bundle and stapled and then stored in the first discharge tray 21 (“staple binding mode” described later). (3) Main body discharge After the sheets from the opening 3 are arranged in a bundle, the sheets are folded into a booklet and stored in the second sheet discharge tray 22 (“sheet bundle folding mode” described later). At the same time, (4) a punch unit C is provided for punching filing punch holes in a sheet processed in each of the above modes (described later in “Punch Processing Mode”).

  Therefore, in the post-processing unit B, as shown in FIG. 2, a sheet carry-in path P1 connected to the main body discharge port 3 of the image forming unit A, the first discharge tray 21 on the downstream side of the path, and the second A paper discharge tray 22 is provided. Reference numeral 20 denotes a casing, to which the sheet carry-in path P1 and the first and second paper discharge trays 21 and 22 are attached, and a device frame 20F (hereinafter referred to as “first device frame”) is built therein.

  The sheet carry-in path P1 is a straight path that crosses the apparatus in a substantially horizontal direction in the casing 20, and the carry-in port 23 is disposed at a position that is continuous with the main body discharge port 3 of the image forming unit A. A stacking tray 29 and a first paper discharge tray 21 connected to the stacking tray 29 are disposed at the paper discharge port 25a of the sheet carry-in path P1. The stacking tray 29 is disposed so as to stack the sheets from the sheet discharge outlet 25a in a reversed manner, and a switchback transport path (hereinafter referred to as “first switchback path”) SP1 is formed between the stacking tray 29 and the sheet discharge outlet 25a. ing. Further, a second switchback path SP2 branched from the sheet carry-in path P1 is disposed, and an accumulation guide 35b for aligning and stacking sheets and a sheet folding device (folding means described later) D are disposed on the downstream side of the path. Has been. Accordingly, in the sheet carry-in path P1, the second switchback path SP2 and the stacking guide 35b are disposed on the upstream side, and the first switchback path SP1 and the stacking tray 29 are disposed on the downstream side.

  In such a path configuration, a carry-in roller (conveying roller means; the same applies hereinafter) 24 and a 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) capable of rotating forward and backward. Has been. A path switching piece 27 for guiding the sheet to the second switchback path SP2 is disposed in the sheet carry-in path P1, and is connected to an operating means such as a solenoid. 26 shown in the figure is a buffer guide, which is arranged in the sheet carry-in path P1 in order to temporarily stay and hold the sheet reaching the second switchback path SP2, and is configured to wait for the fed sheet above the path. .

[Configuration of the first switchback path SP1]
As described above, the first switchback 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 stacking tray 29 is provided below the discharge port 25a with a step difference. 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 broken line position in FIG. 3). In addition, 30b in the drawing is a driven roller, and is provided on the stacking tray 29 at a position where it is engaged with the forward / reverse roller 30. 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, the sheet from the paper discharge outlet 25 a is reversed in the conveying direction above the stacking tray 29 and stored in the stacking tray 29, and the first switchback path SP 1 is formed on the stacking tray 29. 31 is a conveyor belt (endless belt), and its proximal end is pivotally supported by a pulley shaft 31a so as to be brought into pressure contact with the paper discharge roller 25 and carry out a sheet from the paper discharge port 25a. The front end side of the conveyor belt 31 is supported so as to be swingable about a proximal pulley shaft 31 a so as to hang down on the stacking tray 29.

  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 in the reverse direction (counterclockwise in the figure), the sheet on the tray is transferred in the direction opposite to the paper discharge direction. At this time, the conveyance belt 31 switches back and conveys the trailing edge of the sheet along the stacking tray 29 in cooperation with the forward / reverse roller 30.

  A trailing edge regulating member 32 and a stapling device 33 for regulating the position of the trailing edge of the sheet are disposed at the trailing edge of the stacking tray 29 in the paper discharge direction. The illustrated stapling device 33 is constituted by an end-face stitching stapler, and staples one or more places on the trailing edge of the sheet bundle stacked on the stacking tray 29. The stacking tray 29 is provided with a sheet bundle carrying-out mechanism for carrying out the staple-bound sheet bundle to the first paper discharge tray 21 arranged on the downstream side of the stacking tray 29. The sheet bundle carrying-out mechanism has various structures. For example, a claw member 32a that engages with the rear end of the sheet, a drive arm 34a that moves the claw member 32a along the stacking tray 29 in the left-right direction in FIG. 3, and a drive motor M3. Consists of.

  Further, the stacking tray 29 is provided with a side aligning plate 34b for aligning the width direction of the sheets stacked on the tray. For example, the side aligning plate 34b is arranged so that the sheet is aligned with a center reference (may be a side reference). It is composed of a pair of right and left (around FIG. 3) alignment plates so as to be aligned, and is connected to an alignment motor M4 (not shown) so as to approach and leave the sheet center independently.

  The first switchback 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” to be described later, 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 path]
The configuration of the second switchback path SP2 branched from the sheet carry-in path P1 will be described. As shown in FIG. 4, the second switchback path (sheet processing path) SP2 is disposed substantially vertically in the casing 20, and includes a sheet entry path 35a, an accumulation guide 35b, and a switchback entry path 35c. Yes. The sheet entry path 35a and the accumulation guide 35b are connected to form a step as illustrated, and the switchback entry path 35c is connected to the rear end side of the accumulation guide 35b. In the sheet entrance path 35a, a transport roller 36 is disposed at the path entrance, and a transport roller 37 is disposed at the path exit. A saddle stitching stapling device 40 and folding roll means 45 are disposed on the accumulation guide 35b. Hereinafter, these configurations will be sequentially described.

  First, the accumulation guide 35b is formed by a guide member for guiding the conveyance of the sheet, and is configured to stack and store the sheet on the guide. The illustrated accumulation guide 35 b is configured as a part of the second switchback path (sheet processing path) SP <b> 2 and is disposed substantially vertically in the central portion of the casing 20. As a result, the apparatus is made compact and compact. The accumulation guide 35b 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 35c that overlaps the exit end of the sheet entry path 35a is connected to the rear end side in the transport direction of the stacking guide 35b. This is because the leading edge of the loaded (following) sheet sent from the conveying roller 37 in the second switchback path SP2 and the trailing edge of the stacked (preceding) sheet supported by the stacking guide 35b are overlapped. This is to secure the page order. The accumulation guide 35b is provided with a sheet leading edge regulating means 38 for regulating the sheet leading edge on the downstream side of the guide.

[Configuration of sheet tip regulating means]
As shown in FIG. 10, the sheet leading edge regulating means 38 holds a locking member 38a for locking the leading edge of the sheet carried along the stacking guide 35b, and a sheet bundle stacked and supported on the locking member 38a. The grip member 38b is used. The sheet front end regulating means 38 is supported by a guide rail 38g so as to be movable along the accumulation guide 35b. The grip member 38b is axially supported by the locking member 38a and nips the sheet supported by the locking member 38a. An energizing spring 38s and an actuating solenoid 38L are connected to the grip member 38b, and the energizing spring 38s always acts in the grip releasing direction of the seat so that the sheet is gripped and gripped when the actuating solenoid 38L is energized. It has become.

  The sheet leading edge regulating means 38 configured in this way is configured to move between the sh1, sh2, and sh3 shown in the figure by the shift means MS. The shift means MS is composed of a stepping motor 38M, a pinion 38p connected to the stepping motor 38M, and a rack gear 38r integrally formed with the sheet leading edge regulating means 38, and the stepping motor 38M is rotated by a predetermined signal by a detection signal from the home position sensor. By driving, the sheet leading edge regulating means 38 is configured to move to Sh1, Sh2, and Sh3 shown in the figure. The grip member 38b grips the sheet bundle accumulated in the accumulation guide 35b by turning on and off the operation solenoid 38L. In this case, when the sheet leading edge regulating means 38 is moved from the upstream side to the downstream side (Sh3 → Sh1, etc.), the operation solenoid 38L is turned on to control the grip of the sheet bundle. Although the locking member 38a for supporting the leading end of the sheet and the grip member 38b for gripping the sheet bundle supported by this are integrally formed as shown in the figure, they are separated and individually attached to the apparatus frame. Also good.

  The shift means MS moves the sheet leading edge regulating means 38 at least between the illustrated positions Sh1, Sh2, and Sh3. (1) When a sheet enters the stacking guide 35b from the sheet entrance path 35a, the sheet leading edge regulating means 38 is moved to the illustrated position Sh3 so that the rear end of the sheet supported by the stacking guide 35b is returned to the switchback entrance path 35c. (2) When the sheets are stapled by the saddle stitching stapling device 40, the sheet leading edge regulating means 38 is moved to the illustrated position Sh2 so as to position the sheet supported by the accumulation guide 35b at the binding position X. 3) When folding by the folding roll means 45, the sheet leading edge regulating means 38 is moved to the illustrated position Sh1 so that the sheet supported by the stacking guide 35b is positioned at the folding position Y.

  That is, when the sheet leading edge regulating means 38 is positioned at the illustrated position Sh3, the rear end of the sheet (bundle) supported by the stacking guide 35b enters the switchback entry path 35c as shown in FIG. Subsequent sheets sent from the sheet entry path 35a are surely stacked above the accumulated sheets. When the sheet leading edge regulating means 38 is positioned at the illustrated position Sh2, the center of the sheet (bundle) supported by the stacking guide 35b is positioned at the binding position X of the saddle stitching staple device 40 as shown in FIG. Similarly, when the sheet leading edge regulating means 38 is positioned at the illustrated position Sh1, the center of the sheet bundle stapled and supported by the stacking guide 35b as shown in FIG. 12D is set to a folding position Y of a folding roll means 45 described later. It is designed to be positioned. Accordingly, the illustrated positions Sh1, Sh2, and Sh3 are set to optimal positions according to the sheet size (length in the conveyance direction), and are prepared in advance on a memory table or the like.

[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 35b, and a saddle stitching staple device 40 is disposed at the binding position X. This apparatus is composed of a driver unit 40A and an anvil unit 40B, and each unit is configured to be separated at opposing positions with the integrated guide 35b 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 has a driver unit 40A and an anvil unit 40B separated from each other, and each is attached to the apparatus frame so as to be movable in the sheet width direction. Accordingly, the sheet bundle carried between the driver unit 40A and the anvil unit 40B is stapled at the center or at an arbitrary position according to the width size.

[Configuration of folding roll means]
The folding roll means 45 that folds the sheet bundle at the folding position Y arranged on the downstream side of the saddle stitching stapler 40 described above, and the sheet bundle at the nip position NP (near the roll nip; the same applies hereinafter) of the folding roll means 45. Folding blade 46 is provided. As shown in FIGS. 6 (a) and 6 (b), the folding roll means 45 is composed of folding rolls 45a and 45b that are in pressure contact with each other, and each roll is formed substantially in the width of the maximum sheet. A biasing spring is provided on one of the pair of folding rolls 45a and 45b so as to be in pressure contact with each other. The pair of folding rolls 45a and 45b are formed of a material having a relatively large friction coefficient such as a rubber roller.

  Each of the folding rolls 45a and 45b is connected to roll driving means. 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, for example, 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 the folding rolls 45a and 45b are simultaneously fed out of the sheet. It is configured to be freely rotatable in the direction.

  The pair of folding rolls 45a and 45b described above are positioned on the curved or bent protruding side of the stacking guide 35b, and are separated from the sheet bundle supported by the stacking guide 35b by a distance h shown in FIG. Is arranged. That is, the sheet (bundle) supported by the accumulation guide 35b is arranged 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 drive motor M7 between a standby position retracted from the sheet bundle supported by the stacking guide 35b 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 folding rolls 45a and 45b.

  Therefore, in the figure, the relationship between the friction coefficient ν1 between the folding rolls 45a and 45b and the sheet, the friction coefficient ν2 between the sheets, and the friction coefficient ν3 between the sheet and the folding blade 46 is “ν1> ν2> ν3. "Is set. Therefore, in the state where the sheet bundle shown in FIG. 8B 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 the both folding rolls 45a and 45b is It reaches each as a force equal to the sheet bundle and 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 reciprocate between a standby position retracted from the sheet supported by the stacking guide 35b and a nip position of the folding rolls 45a and 45b. The blade drive means BM for reciprocating the folding blade 46 is constituted by 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 constituted by a plate-like member having a knife edge in the sheet width direction, and the tip thereof 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 35b in the form of a bundle is locked by the sheet leading edge regulating means 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 is rotated at a lower speed than the moving speed of the folding blade 46. This is to create a condition for the first and second folding rolls 45a and 45b to be driven and rotated by the sheet bundle inserted at 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 speed VR of the folding rolls 45a and 45b 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. Around this time, the drive control means 64d switches the clutch means 45c to the ON state to drive and rotate the 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 to the standby position in parallel with the feeding of the sheet bundle by the folding rolls 45a and 45b in the state shown in FIG.

  When the sheet bundle thus folded is first engulfed between the pair of folding rolls 45a and 45b, the sheet in contact with the roll surface is not drawn between the rolls by the rotating roll. That is, since the folding rolls 45a and 45b are rotated (followed) by the inserted (pushed) sheet, only the sheet that comes into contact with the roll is not first wound. Further, since the folding rolls 45a and 45b follow and rotate following the inserted sheet, the roll surface and the sheet in contact therewith are not rubbed, and image rubbing is not caused.

  As described above, the “post-processing unit B” is connected to the first apparatus frame 20F provided in the casing 20, the sheet carry-in path P1, the sheet stacking means (the stacking tray 29 and the stacking guide 35b described above), and the sheet binding. Processing means (the above-described end-face stitching stapling device 33 and saddle stitching stapling device 40) are provided. And the control part which controls these post-processing apparatuses is comprised so that it may mention later.

"Punch unit configuration"
In the above-described post-processing unit B, the punch unit C is attached to the sheet carry-in path P1 as follows. As shown in FIG. 3 and an enlarged view of FIG. 5A, the punch unit C includes an apparatus frame (hereinafter referred to as “second apparatus frame”) 70 and an outer casing 71 (not shown). A sheet guide 73, a punch member 72, a punch drive motor M8, and a sheet sensor S1 disposed in the sheet guide 73 are incorporated in the apparatus frame 70, respectively.

  The second device frame 70 is configured separately from the device frame (first device frame) 20F of the post-processing unit B described above, and is detachably connected to the first device frame 20F with a bolt or the like. This is because the punch unit C is attached to the post-processing unit as an option according to the use needs in the apparatus specifications, and is attached at the factory or attached by a dealer or the like according to the configuration. An outer casing 71 that matches the outer dimensions and exterior design of the post-processing unit B is attached to the second apparatus frame 70.

  The second apparatus frame 70 is provided with a sheet guide 73 connected to the above-described sheet carry-in path P1. The sheet guide 73 includes an upper guide plate 73a and a lower guide plate 73b, and is arranged so as to guide the sheet from the main body discharge port 3 of the image forming unit A to the sheet carry-in path P1 of the post-processing unit B. Yes. A punch member 72 is attached to the upper guide plate 73a so as to be vertically movable between a top dead center and a bottom dead center. The punch members 72 are arranged at two places in the sheet width direction (the front-rear direction in FIG. 5) or at four places, and a plurality of punch members 72 according to the standard so that two holes, three holes, four holes or more file holes are formed in the sheet. It is comprised by the punch member. Thus, the punch member 72 is attached to the second apparatus frame 70 so as to be vertically movable between a top dead center set above the sheet guide 73 and a bottom dead center set below.

  A punching blade 72a is provided at the tip of the punch member 72, and an engagement hole is provided in the upper guide plate 73a to match the punching blade 72a. The second device frame 70 is provided with a punch drive motor M8 that moves the punch member 72 up and down, and a drive cam member 74 that transmits the rotation of the motor to the punch member 72. 75 in the figure is a drive shaft connected to the drive motor M8, and a drive cam member 74 constituted by an eccentric cam is supported on the shaft. The punch member 72 is provided with a return spring (not shown) between the punch device 72 and the second device frame 70. Although not shown, the drive shaft 75 is provided with a position sensor, an encoder, and the like for detecting the rotational angle position, thereby controlling the vertical position of the punch member 72.

  The lower guide plate 73b is constituted by a die plate having a blade receiving hole 72b that fits (fits) with the punching blade 72a of the punch member 72. Below the lower guide plate 73b, a waste box 76 is provided for storing a piece of paper falling from the blade receiving hole 72b. Further, the lower guide plate 73b is provided with a rear end abutting stopper 77 for positioning the sheet by a stepped wall, and as described later, the rear end of the sheet is moved to the punch position in cooperation with the carry-in roller 24 of the post-processing unit B. It is designed to be positioned. The upper guide plate 73a and the lower guide plate 73b are provided with a sheet sensor S1 for detecting the rear end of the sheet over one or both of them. The illustrated sensor S1 is constituted by a reflection type photosensor, and is attached to the upper guide plate 73a.

  As shown in FIG. 5A, the first device frame 20F is provided with a base support portion 20G for mounting and supporting the lower frame 70b of the second device frame 70. The pedestal support 20G is detachably connected to the lower frame 70b by a fixing means such as a bolt. The second device frame 70 is disposed so as to protrude outward (image forming apparatus A side) from the first device frame 20F (the distance L in the drawing). As described above, the second device frame 70 is protruded outward from the first device frame 20F. The impact of the punching operation that occurs in the punch member 72 is reliably caused by the pedestal support portion 20G provided on the first device frame 20F. It is for supporting.

  As is clear from the above description, the first device frame 20F and the second device frame 70 are (1) constituted by separate housing members, and the second device frame 70 is detachably attached to the first device frame 20F. It has been. (2) The first apparatus frame 20F is provided with a conveyance roller means (the above-described carry-in roller 24) for nipping and carrying the sheet in the sheet carry-in path P1. (3) In the second apparatus frame 70, a sheet sensor S1 for detecting the trailing end of the sheet is disposed at the carry-in entrance 23. Therefore, the punch drive motor M8 is electrically connected so as to receive power supply and motor ON / OFF control signals from the operation control means (control circuit) of the first apparatus frame 20F, and the sheet rear end from the sheet sensor S1. Based on the detection signal, the conveying roller means 24 is stopped, and the punch member 72 is moved from the top dead center to the bottom dead center in a state where the sheet is nipped to punch the sheet. The sheet after the punching operation is configured to be transported to the downstream sheet stacking unit (the stacking tray 29 or the stacking guide 35b) by the conveying roller unit 24.

  The carry-in roller (conveying roller means) 24 disposed in the sheet carry-in path P1 of the post-processing unit B described above can be rotated forward and backward to position the sheet rear end at a predetermined punch position with the above-described rear end abutting stopper 77. It is connected to a drive motor M1 (not shown). The driving motor M1 is driven to rotate in the reverse direction after the expected time when the sheet trailing edge has passed the stopper 77 with reference to the sheet trailing edge detection signal from the sheet sensor S1. As a result, the rear end of the sheet backs against the stopper 77 that has passed through one end and is abutted against the stopper. Accordingly, the sheet from the carry-in port 23 can be set at an accurate punch position without variation, and at the same time, the skew (skew) of the sheet can be corrected. The drive motor M1 is controlled to stop after the expected time when the trailing edge of the sheet is regulated by the stopper 77, and wait for the end of the punching operation with the sheet nipped. The drive motor M1 rotates, for example, in response to the punching operation end signal of the punch member 72 described above, and transports the punched sheet in the paper discharge direction (left side in FIG. 5A).

  Next, the configuration of the post-processing unit B that is not provided with the above-described punch unit C shown in FIG. 5B will be described. The carry-in unit E is attached to the first apparatus frame 20F of the post-processing unit B configured as described above. The carry-in entrance unit E includes a third device frame 78, an outer casing 79, a carry-in guide 80, and a sheet sensor S1 disposed in the guide. The third device frame 78 is attached to the first device frame 20F with a bolt or the like, and the outer casing 79 is provided on the third device frame 78 so that the size and the design of the casing 20 match the casing 20 of the post-processing unit B. . Further, the third apparatus frame 78 is provided with a carry-in guide 80 for guiding the sheet from the main body discharge port 3 of the image forming unit A to the carry-in roller 24. A sheet sensor S1 having the same configuration as described above is disposed in the carry-in entrance guide 80.

[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 unit A and a control unit (hereinafter referred to as “post-processing control unit”) 60 of the post-processing unit 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 50 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. In the RAM 63, position data of the sheet locking positions Sh1, Sh2, Sh3 of the sheet leading edge regulating means 38 is prepared in a data table, for example, in accordance with the size (length in the conveying direction) of the sheet transferred to the sheet processing path P2. ing. The control CPU 61 includes a sheet conveyance control unit 64 a that performs conveyance of the sheet sent to the carry-in entrance 23, a sheet accumulation operation control unit 64 b that performs sheet accumulation operation, and a sheet binding process that performs sheet binding processing. An operation 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 drive motor M1 for the carry-in roller 24 and the discharge roller 25 in the sheet carry-in path P1 and receives a detection signal from the sheet sensor S1 arranged in this path. It is configured as follows. Further, the sheet stacking operation control unit 64b drives the forward / reverse rotation motor M2 of the forward / reverse rotation roller 30 and the discharge motor M3 of the trailing end regulating member 32 in order to stack sheets on the first stacking unit (stacking tray) 29. Connected to the circuit. Further, the sheet binding processing operation control unit 64c is connected to a driving circuit of a driving motor M built in the end-stitching stapling device 33 of the stacking tray 29 and the saddle stitching stapling device 40 of the second stacking unit (stacking guide) 35b. Yes.

  The sheet folding operation control unit 64d is connected to a drive circuit of a roll drive motor M6 that drives and rotates the folding rolls 45a and 45b and a control circuit of the clutch means 45c. The sheet folding operation control unit 64d is connected to a control circuit of a shift unit MS that controls the movement of the transport rollers 36 and 37 of the sheet entrance path 35a and the sheet leading end regulating unit 38 of the stacking guide 35b to predetermined positions. It is wired so as to receive a detection signal from a sheet sensor arranged in the route.

The control unit configured as described above causes the post-processing unit B to execute the next processing operation. Hereinafter, the operation of the apparatus configuration in which the post-processing unit B is provided with the punch unit C described in FIG. 5A will be described. In the control unit 50 of the above-described image forming unit A, the “print-out mode”, “staple binding finishing mode”, and “sheet bundle folding finishing mode” post-processing mode are selected by the mode setting unit.
In the “print-out mode”, the sheet from the image forming unit A is carried out to the first paper discharge tray 21 without any post-processing.
In the “staple binding finishing mode”, the sheets from the image forming unit A are stacked on the stacking tray 29 through the sheet carry-in path P1 and aligned, and then the trailing edge of the sheet is bound by the end-face binding stapler 33 disposed on the tray. After matching, the bundle is carried out to the first paper discharge tray 21.
In the “sheet folding finishing mode”, the sheets from the image forming unit A are stacked on the stacking guide 35b through the second switchback path SP2 from the sheet carry-in path P1 and aligned. Then, after the center portion of the sheet bundle is bound by the saddle stitching staple device 40, the sheet bundle is folded into a booklet by the folding roll means 45, and is carried out and stored in the second paper discharge tray 22.

"Punch processing mode"
Further, the above-described control unit 50 sets a “punch processing mode” as to whether or not punch holes are to be punched in a sheet image-formed by the image forming unit A simultaneously with the setting of the post-processing mode. That is, in any of the above-described post-processing modes, it is possible to select whether or not to punch holes on the image-formed sheet. The punch processing mode will now be described. The image forming unit A forms a series of documents from, for example, the first page and sequentially carries out from the main body discharge port 3.

  The post-processing unit B guides the sheet from the main body discharge port 3 to the carry-in roller 24 of the post-processing unit B by the sheet guide 73 of the punch unit C. Then, the sheet is transferred by the carry-in roller 24 to the downstream side of the sheet carry-in path P1. For this reason, the control CPU 61 of the post-processing unit B starts to rotate the drive motor M <b> 1 in response to the leading edge detection signal from the sheet sensor S <b> 1 disposed in the sheet guide 73. The rotation direction at this time rotates the carry-in roller 24 in the clockwise direction in FIG. 3, and transports the sheet toward the path sheet discharge port 25a. When the sheet sensor S1 detects the trailing edge of the sheet, the control CPU 61 stops the driving motor M1 after the estimated time that the trailing edge of the sheet passes the stopper 77 based on this detection signal, and then reversely rotates the driving motor M1. Then, the carry-in roller 24 rotates counterclockwise in FIG. 3, and the sheet backs the sheet carry-in path P1 in the direction opposite to the paper discharge direction. As a result, the trailing edge of the sheet is regulated against the stopper 77, and then the carry-in roller 24 slides and rotates on the stationary sheet.

  Next, the control CPU 61 stops the carry-in roller 24 after the expected time when the sheet trailing edge is restricted against the stopper 77. Then, the sheet comes to rest while being nipped by the carry-in roller 24. Next, the control CPU 61 supplies power to the punch drive motor M8, rotates the drive shaft 75, and drives and rotates the drive cam member 74. Then, the punch member 72 engaged with the drive cam member 74 moves from the top dead center to the bottom dead center, and punches a punch hole in the sheet stationaryly set on the lower guide plate 73b. Therefore, the control CPU 61 stops the punch drive motor M8 when a position sensor (for example, a home position sensor; not shown) arranged on the drive shaft 75 detects the return to the top dead center of the punch member 72.

  Next, after the drive motor M8 is stopped, the control CPU 61 rotates the carry-in roller 24 again in the paper discharge direction (clockwise in FIG. 3) and conveys the punched sheet to the downstream side of the sheet carry-in path P1. This sheet is processed as follows according to the post-processing mode described above.

"Printout mode"
In this mode, the image forming unit A forms an image of a series of documents from, for example, the first page and sequentially carries out from the main body discharge port 3. Therefore, the post-processing unit 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 and reverse rollers are 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. 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 formed with the image forming unit A are accommodated in the first paper discharge tray 21 via the sheet carry-in path P1 of the post-processing unit B. The pages are stacked and stored in the order of the pages. In this mode, no sheet is guided to the first switchback path SP1 and the second switchback path (sheet processing path) SP2.

"Staple binding finish mode"
In this mode, the image forming unit A forms an image of a series of documents in the order from the first page to the nth page as in the above-described printout mode, and carries it out from the main body discharge port 3 in a face-down state. Accordingly, the post-processing unit B retracts the buffer guide 26 of the sheet carry-in path P1 upward in FIG. 3 as in the previous mode, 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 and reverse rollers are 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 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 unit A to bind the trailing edge of the sheet bundle stacked on the stacking 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 on the first paper discharge tray 21. As a result, a series of sheets formed by the image forming unit A is stapled and stored in the first paper discharge tray 21.

"Sheet fold finish mode"
In this mode, the image forming unit A forms an image on a sheet, and the post-processing unit B finishes it in a booklet shape. Therefore, the post-processing unit 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, 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 sheet entry path 35a. And it guides to the accumulation | aggregation guide 35b with the conveyance rollers 36 and 37 arrange | positioned in this path | route.

  The control CPU 61 moves the sheet leading edge regulating means 38 to the lowermost position Sh1 at the timing when the sheet is carried into the stacking guide 35b from the sheet entry path 35a (state shown in FIG. 11A). The control CPU 61 moves the position of the sheet leading edge regulating means 38 to an optimum position corresponding to the sheet length from the sheet size information (length in the conveying direction) from the image forming apparatus A and the position data stored in the RAM 63. . Then, the entire sheet is supported by the accumulation guide 35b. In this state, the control CPU 61 operates the aforementioned sheet side edge aligning means 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 sheet leading edge regulating means 38 to a position Sh3 where the sheet trailing edge enters the switchback entry path 35c described above. FIG. 11B shows this state, and the control CPU 61 moves the sheet leading edge regulating means 38 from the position data stored in the RAM 63 to a position Sh3 where the trailing edge of the sheet enters the switchback entry path 35c. Then, the rear end of the sheet supported by the accumulation guide 35b moves backward to the switchback entry path 35c. In this state, subsequent sheets are fed from the sheet entry path 35a onto the accumulation guide 35b, and the subsequent sheets are stacked on the preceding sheet. Then, the sheet leading edge regulating means 38 is moved from the Sh3 position to the Sh1 position in accordance with the carry-in of the succeeding sheet (the state shown in FIG. 11A).

  Next, the control CPU 61 operates the sheet side edge aligning means 39 in the state shown in FIG. 11A to align the loaded sheet and the sheet supported on the stacking guide. By repeating such an operation, the sheets formed with the image by the image forming apparatus A are aligned on the stacking guide 35b through the sheet entrance path 35a.

  Next, when receiving a job end signal, the control CPU 61 moves the sheet leading edge regulating means 38 to the position Sh2, and sets the center of the sheet to the binding position X. FIG. 12C shows this state, and the control CPU 61 sends a command signal for executing a stapling operation to the saddle stitching stapler 40 after moving the sheet leading edge regulating means 38 to Sh2. Then, the saddle stitching staple device 40 staples one or a plurality of locations in the center of the sheet.

  In response to the staple operation completion signal, the control CPU 61 moves the sheet leading edge regulating means 38 to the position Sh1 and positions the sheet center at the folding position Y (state shown in FIG. 12D). 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.

1 is an overall explanatory diagram of an image forming system according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall explanatory view of a post-processing unit 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. It is explanatory drawing of the punch unit in the apparatus of FIG. 3, (a) shows the mounted state, (b) is a non-mounted state diagram. 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. FIG. 5 is an explanatory diagram illustrating a configuration of a sheet leading edge regulating unit in the apparatus of FIG. 4. FIGS. 5A and 5B are operation state explanatory diagrams of the sheet leading edge regulating unit in the apparatus of FIG. 4, in which FIG. 5A is a state in which the first sheet enters the stacking guide, and FIG. FIGS. 5A and 5B are operation state explanatory views of the sheet leading edge regulating means in the apparatus of FIG. 4, in which FIG. 5C is a state diagram for positioning the sheet bundle accumulated in the accumulation guide at a binding position, and FIG. The state figure which positions a bundle in a folding position.

Explanation of symbols

A Image forming unit B Post-processing unit C Punch unit P1 Sheet carry-in path SP1 First switchback path SP2 Second switchback path (sheet processing path)
20 Casing 20F First device frame 20G Pedestal support portion 21 First paper discharge tray 22 Second paper discharge tray 23 Carry-in port 24 Carry-in roller (carrying roller means)
25 Paper discharge roller 29 Stack tray (first stack unit)
33 End-bound staple device 35a Sheet entry path 35b Stack guide (second stack section)
35c Switchback entry path 36 Conveying roller 37 Conveying roller 38 Sheet leading edge regulating means 40 Saddle stitching stapling device 45 Folding roll means 46 Folding blade 60 Post-processing control unit 70 Second device frame 72 Punch member 73 Sheet guide 74 Drive cam member 75 Drive Shaft 76 Waste box 77 Stopper M8 Punch drive motor S1 Sheet sensor

Claims (4)

An image forming apparatus that forms an image on a sheet, and a post-processing apparatus that post-processes the image-formed sheet,
The post-processing device is
Sheet carry-in route,
A punch unit that is arranged to be continuous with the sheet carry-in path, and punches punch holes in the sheet that is sent to the sheet carry-in path;
Tray means for collecting and collecting sheets from the sheet carry-in path;
Post-processing means for performing a binding process and / or a folding process on the sheet bundle stacked on the tray means ;
Processing operation control means for controlling the post-processing operation by the post-processing means;
A first apparatus frame equipped with the sheet carry-in path, tray means and post-processing means;
With
The punch unit is
A carry-in entrance for carrying in a sheet sent from the image forming apparatus;
A sheet guide for transferring the sheets from the entrance to the sheet conveyance path,
A punch member for perforating the sheet on the sheet guide;
Punch driving means for moving the punch member up and down;
A second apparatus frame equipped with the sheet guide, the punch member and punch driving means;
With
The second device frame is composed of a member separated from the first device frame,
The first device frame is provided with a pedestal support portion for placing and supporting the second device frame in a state where the carry-in port of the second device frame protrudes toward the image forming device.
The pedestal support unit supports the impact force of the punch member in a state in which a part of the second apparatus frame protrudes outward . The first apparatus frame is provided with conveying roller means for nipping and conveying the sheet downstream of the sheet guide of the second apparatus frame,
This conveying roller means is composed of a roller capable of forward and reverse rotation,
In the sheet guide ,
Stopper means for restricting butting the rear end of the sheet ;
A sheet sensor for detecting the trailing edge of the sheet is arranged,
The processing operation control means reversely rotates the conveying roller means based on a sheet trailing edge detection signal from the sheet sensor, and drives and controls the punch driving means in a state where the sheet trailing edge is abutted against the stopper means. The image forming system according to claim 1. The sheet guide is composed of a pair of upper and lower guide plate members arranged at a predetermined interval,
In the upper guide plate member, the punch member is arranged to be movable up and down between the top dead center and the bottom dead center,
3. The image forming system according to claim 1, wherein a blade receiving hole adapted to the punch member is formed in the lower guide plate member. The sheet carry-in path is arranged in a substantially horizontal direction on the first device frame,
Said tray means is the branch from the sheet conveyance path, the image forming system according to claim 1, characterized in Tei Rukoto disposed switchback path curved downwardly.

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