JP2013205589A - Sheet post-processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fast and efficiently perform processing by simultaneous execution of an operation of carrying a sheet into a processing tray and an operation of carrying out another sheet.SOLUTION: A sheet post-processing device includes: a sheet ejection path 31; a processing tray 32 arranged blow an outlet port of the sheet ejection path 31; a stack tray arranged below the processing tray; sheet carrying-in means 40 which carries a sheet from the sheet ejection path into the processing tray; sheet carrying-out means 68 which carries out a sheet from the processing tray to the stack tray; and control means which controls the sheet carrying-in means and the sheet carrying-out means. The sheet carrying-in means comprises a pair of carrying-in rollers which transport a sheet sent from the sheet ejection path to the processing tray, and the sheet carrying-out means is arranged between the processing tray and the stack tray and comprises a pair of carrying-out rollers 40b and 68 for transporting a sheet on the processing tray to the stack tray. The control means simultaneously executes, in parallel, sheet carrying-in by the pair of carrying-in rollers and sheet carrying-in by the pair of carrying-out rollers when a processed sheet is carried out from the processing sheet and a following sheet is carried in.

Description

  The present invention relates to a sheet post-processing apparatus that feeds an image-formed sheet to a processing tray, performs post-processing, and stores the sheet in a downstream stack tray, and a control mechanism that efficiently executes post-processing of consecutive sheets at high speed. Regarding improvement.

  In general, this type of post-processing apparatus is connected to a paper discharge port of the image forming apparatus, and finishes by performing post-processing such as binding processing, punching processing, and sealing processing by aligning and stacking image-formed sheets. It is known as an apparatus for storing sheets (bundles) in a stack tray.

  For example, in Patent Document 1, a sheet sent from an image forming apparatus is switched back and conveyed to a processing tray disposed below a paper discharge port, and a binding process is performed by a post-processing device such as a stapler device disposed on the tray. A device for storing the bound sheet bundle in the downstream stack tray is disposed.

  This document discloses a post-processing apparatus having an inner finisher structure in which a post-processing unit is mounted in a paper discharge area provided in a housing of an image forming apparatus.

  In Patent Document 2, a sheet discharged at high speed from the image forming apparatus is collected in a buffer path, and a subsequent sheet whose preceding sheet is sent during post-processing by a processing tray is accumulated in a buffer path. A mechanism for dropping and storing a sheet in a processing tray is disclosed.

JP 2011-037591 A JP 2007-308215 A

  As described above, various structures are already known for post-processing apparatuses that send sheets sent from the image forming apparatus to the processing tray, perform post-processing such as binding processing, and then store the sheets in the stack tray. Conventionally, in such an apparatus, a sheet is transferred from an image forming apparatus or the like to a processing tray for post-processing, and the post-processed sheet (bundle) is stored in a downstream stack tray. After the process is completed, the next sheet is transferred from the paper discharge path to the processing tray. In other words, the sheet conveyance timing for stacking sheets on the processing tray and the sheet conveyance timing for carrying out post-processed sheets to the stack tray and loading subsequent sheets into the tray are greatly different. The problem of long time is known.

  In order to eliminate the interval at the end of the job, Japanese Patent Application Laid-Open No. 2004-228561 proposes arranging a buffer path for temporarily retaining sheets in the sheet discharge path. However, the arrangement of such a buffer path necessitates a space for that purpose and a transport mechanism, which leads to an increase in size and cost of the apparatus.

  Accordingly, the present inventor has come up with the idea that a mechanism for carrying in a sheet and a mechanism for carrying out a sheet are separately arranged in the carry-in entrance of the processing tray, and the carry-in and carry-out of the sheet are executed in parallel.

  The present invention increases the processing speed by simultaneously performing a sheet carry-in operation to the processing tray and a carry-out operation when the sheet is carried from the paper discharge path into the processing tray and then post-processed and stored in the stack tray. The purpose is to improve efficiency.

  In order to achieve the above object, the present invention has a pair of carry-in rollers and a pair of carry-out rollers arranged at the entrance / exit of the process tray, the sheets are carried into the process tray by the pair of carry-in rollers, and the sheets are stacked from the process tray by the pair of carry-out rollers. Transfer to tray. In view of this, it is characterized in that the carry-out and carry-in of the sheet are carried out in parallel by rotating the carry-out roller pair at the same time or overlapping in time.

In this case, after the carry-out roller pair is rotated, the rotation of the carry-in roller pair is simultaneously rotated so that the rear end portion of the sheet to be carried out and the front end portion of the carry-in sheet are not overlapped with each other. As a result, it is possible to prevent the front end of the sheet from being caught on the staple needle at the rear end of the sheet.

  Further, the configuration will be described in detail. An apparatus for storing sheets carried out from the paper discharge path 31 in a stack tray 33 after being post-processed by a processing tray 32 disposed in the downstream of the paper discharge opening 30, and having a paper discharge opening 30. A processing tray disposed on the downstream side of the paper discharge port, a stack tray 33 disposed on the downstream side of the processing tray, a sheet carry-in means 40 for carrying sheets into the processing tray from the paper discharge path, and a processing tray. A sheet unloading means 68 for unloading sheets to the stack tray, and a control means for controlling the sheet loading means and the sheet unloading means are provided.

  The sheet carry-in means is constituted by a pair of carry-in rollers (first and second rollers 40a and 40b described later) that are arranged at the paper discharge port and transfer the sheet sent from the paper discharge path to the processing tray. A pair of carry-out rollers (second and third rollers 40b and 68 to be described later) are arranged between the tray and the stack tray and transfer sheets on the processing tray to the stack tray. Therefore, when the processed sheet is unloaded from the processing tray and the subsequent sheet is loaded, the control unit 83 causes the rotation of the pair of carry-in rollers and the pair of carry-out rollers to be simultaneously carried out or overlapped to carry out the sheet from the process tray. Carry in in parallel.

  In this case, the paper discharge path and the processing tray are arranged so that the sheet carried out from the paper discharge outlet is reversed and conveyed into the processing tray, and the processing tray and the stack tray are separated from the paper discharge path. It arrange | positions so that a sheet may be carried out in the same direction as the sheet carried out. The first, second, and third rollers that are in pressure contact with each other are disposed at the paper discharge port. The first roller 40a and the second roller 40b serve as a pair of carry-in rollers, and the second roller 40b and the third roller 68 serve as a carry-out roller. Configure a pair.

  The present invention has a configuration in which a pair of carry-in rollers and a pair of carry-out rollers are arranged at the entrance / exit of the processing tray, the sheet is carried into the processing tray by the pair of carry-in rollers, and the sheet is carried out to the stack tray by the pair of carry-out rollers. Since the pair carry-out operation and the carry-in operation of the carry-in roller pair are performed simultaneously, the following effects are obtained.

  Since the operation of carrying out the succeeding sheet is performed simultaneously with the operation of carrying out the processed sheet from the processing tray, it is possible to efficiently perform the post-processing of the continuously placed sheets at high speed. In particular, it is possible to set a short interval for carrying in the succeeding sheet from carrying out the post-processed sheet, which is suitable for, for example, post-processing of a sheet that is continuously carried out from the image forming apparatus.

  In the present invention, the second roller pair for carrying out the sheet from the processing tray is rotated, and then the first roller pair is rotated so that the trailing edge of the sheet carried out from the processing tray and the leading edge of the sheet carried in are rubbed with each other. In combination, it is possible to prevent the jam.

  Further, according to the present invention, the first roller pair and the second roller pair are constituted by the first, second, and third rollers that are pressed against each other, and the first roller and the third roller can be pressed against and separated from the second roller located in the middle. Configure. As a result, the sheet (bundle) carried out from the processing tray is nipped by the second roller and the third roller and lifted upward from the processing tray, so that the friction between the tray paper loading surface and the carried sheet can be reduced and carried out smoothly. Can do.

1 is an overall configuration explanatory diagram of an image forming system according to the present invention. Explanatory drawing of the principal part of the post-processing apparatus C in the system of FIG. FIG. 3 is an explanatory perspective view illustrating a relationship between a partition guide, which is a paper discharge mechanism of the post-processing apparatus in FIG. FIG. 3 is an explanatory diagram of a detailed configuration of a paper discharge mechanism of the post-processing apparatus of FIG. 2. (A) is explanatory drawing which shows the relationship (paper discharge mechanism) of the partition guide of FIG. 3, a roller, and a side edge alignment member, (b) is explanatory drawing of the different surface of the paper discharge mechanism. 2 is an explanatory view showing the configuration of the skew correction means and the side edge alignment means of the paper discharge mechanism section, (a) is a planar configuration, (b) is an elevational configuration. 2A shows an operation state of the paper discharge mechanism, FIG. 2A shows an initial state where the sheet enters the paper discharge path, and FIG. 2B shows a state where the rear end of the sheet is detached from the conveying roller. 2A and 2B show the operation state of the paper discharge mechanism, in which FIG. 2C shows a state in which the rear end of the sheet is guided from the discharge path to the back conveyance path, and FIG. Each hit state is shown. 2 shows an operation state of the paper discharge mechanism, FIG. 2E shows a state in which the roller and the partition guide plate are retracted sideways from the sheet engagement position, and FIG. 2F shows a sheet stapled after the post-processing operation. A state in which the bundle is nipped between the carry-out roller and the roller and carried to the stack tray is shown. 2 shows the operation state of the paper discharge mechanism, (g) shows the initial state of the operation of carrying out the processed sheet from the processing tray and each operation of carrying in the subsequent sheet, and (h) shows the leading end of the subsequent sheet. FIG. 4B is an explanatory diagram illustrating a state where a tray is loaded, and (i) is a diagram illustrating a state where a processing sheet is unloaded and a subsequent sheet is unloaded. (A) shows the structure of the sheet pressing means, (b) shows an embodiment different from FIG. 3 of the stacked sheet alignment means in the processing tray, and the alignment surface and the guide surface of the partition guide plate are located at different positions in the sheet width direction. Explanatory drawing to arrange | position. Explanatory drawing which shows the raising / lowering mechanism of a stack tray. The block diagram which shows the control structure in the system of FIG. Explanatory drawing which shows the operation program of the control means in the control structure of FIG. Explanatory drawing which shows the specific operation | movement flow of the control means in the control structure of FIG. FIG. 14 is an operation flow explanatory diagram showing sheet carry-in to a processing tray and processed sheet carry-out operation in the control configuration of FIG. 13.

  The present invention will be described in detail below according to the preferred embodiments shown in the drawings. FIG. 1 shows an image forming system according to the present invention. This system includes an image forming unit A, an image reading unit B, and a post-processing unit C. The original image is read by the image reading unit B, and an image is formed on the sheet by the image forming unit A based on the image data. Then, finishing processing such as binding processing is performed on the image-formed sheet by the post-processing unit C.

  The illustrated post-processing unit C is configured as an apparatus that performs a binding process by aligning and stacking sheets on which images are formed and incorporated in the paper discharge area 15 of the image forming unit A. The image reading unit B is mounted above the image forming unit A, and a post-processing unit C is disposed between the two units.

  In addition, the image forming unit A, the image reading unit B, and the post-processing unit C may be configured as independent stand-alone structures, and each apparatus may be connected by a network cable to form a system. In this case, the carry-in port 34 of the post-processing unit C is connected to the paper discharge port 16 of the image forming unit A. Hereinafter, the image forming unit A, the image reading unit B, and the post-processing unit C shown in the figure position will be described in this order.

[Image forming unit]
As shown in FIG. 1, the image forming unit A includes a paper feeding unit 1, an image forming unit 2, a paper discharge unit 3, and a signal processing unit (not shown), and is built in the apparatus housing 4. The sheet feeding unit 1 includes a cassette 5 that stores sheets. The illustrated unit includes a plurality of cassettes 5a, 5b, and 5c, and can store sheets of different sizes. Each of the cassettes 5a to 5c has a built-in sheet feeding roller 6 for feeding out the sheet and separation means (separation claw, separation roller, etc .; not shown) for separating the sheets one by one.

  Further, the sheet feeding unit 1 is provided with a sheet feeding path 7 to feed sheets from each cassette 5 to the image forming unit 2. A pair of registration rollers 8 is provided at the end of the sheet feeding path 7 so that the sheets fed from the respective cassettes 5 are aligned at the leading edge, and waits until the sheet is fed according to the image forming timing of the image forming unit 2.

  As described above, the sheet feeding unit 1 is configured by a plurality of cassettes according to the apparatus specifications, and is configured to feed a sheet having a size selected by the control unit to the image forming unit 2 on the downstream side. Each cassette 5 is detachably attached to the apparatus housing 4 so that sheets can be replenished.

  The image forming unit 2 can employ various image forming mechanisms for forming an image on a sheet. The illustrated one shows an electrostatic image forming mechanism. As shown in FIG. 1, a plurality of drums 9 a to 9 d made of a photoconductor (photoconductor) are arranged in the apparatus housing 4 according to color components. Each drum 9a, 9b, 9c, 9d is provided with a light emitter (laser head or the like) 10 and a developing device 11. Then, a latent image (electrostatic image) is formed on each of the drums 9 a to 9 d by the light emitter 10, and toner ink is attached by the developing device 11. The ink images attached on the drums are transferred to 12 for each color component and are combined.

  The transfer image formed on the belt is transferred onto the sheet sent from the paper feeding unit 1 by the charger 13, fixed by the fixing device (heating roller) 14, and then sent to the paper discharge unit 3.

  The paper discharge unit 3 includes a paper discharge port 16 for carrying out a sheet to a paper discharge area 15 formed in the apparatus housing 4 and a paper discharge path 17 for guiding the sheet from the image forming unit 2 to this paper discharge port. Yes. Note that a duplex path 18 (described later) is connected to the paper discharge unit 3 so that a sheet having an image formed on the front surface is reversed and fed to the image forming unit 2 again.

[Duplex route]
In the duplex path 18, the sheet on which the image is formed on the front side by the image forming unit 2 is reversed and retransmitted to the image forming unit 2. Then, after the image forming unit 2 forms an image on the back surface side, the image is discharged from the paper discharge port 16. For this reason, the duplex path 18 includes a switchback path 18a for returning the sheet sent from the image forming unit 2 to the inside of the apparatus by reversing the conveyance direction, and a U-turn path 18b for turning the sheet returned to the inside of the apparatus upside down. Has been. In the illustrated apparatus, the switchback path 18a is formed in the paper discharge path 31 of the post-processing unit C described later.

[Image reading unit]
The image reading unit B includes a platen 22 and a reading carriage 23 that reciprocates along the platen. The platen 22 is made of transparent glass, and includes a still image reading surface that scans a still image by moving the reading carriage 23 and a traveling image reading surface that reads a document image traveling at a predetermined speed.

  The reading carriage 23 includes a light source lamp, a reflection mirror that changes reflected light from the document, and a photoelectric conversion element (not shown). The photoelectric conversion element is composed of line sensors arranged on the platen in the document width direction (main scanning direction), and the reading carriage 23 reciprocates in the sub-scanning direction orthogonal to this to read the document image in line order. It has become. Further, an automatic document feeder 24 that moves the document at a predetermined speed is mounted above the traveling image reading surface of the platen 22. The automatic document feeder 24 is composed of a feeder mechanism that feeds original sheets set on a paper feed tray one by one to a platen and stores them in a paper discharge tray after reading an image.

[Post-processing unit]
The processing unit C performs post-processing on the sheet sent from the image forming unit A and stores it in the stack tray 33. FIG. 2 shows the overall configuration of the post-processing unit C. A device for mounting the post-processing unit C as an option is built in a paper discharge area 15 (see FIG. 1) provided in the image forming unit A. The post-processing unit C is configured to store the sheets sent to the main body discharge port 16 of the image forming unit A in a stack tray 33 after the sheets are aligned and stacked and then bound.

  Therefore, the post-processing unit C is disposed on the downstream side of the processing tray 32, the paper discharge path 31 having the paper discharge outlet 30, the processing tray 32 that forms a step h with the paper discharge outlet 30, and the downstream side. The stack tray 33 stores post-processed sheet bundles. The processing tray 32 and the stack tray 33 shown in the figure have a bridge support structure in which the front end of the sheet is supported by the stack tray 33 and the rear end is supported by the processing tray 32, and the sheet sent from the paper discharge port 30 is stacked with the processing tray 32. A layout configuration that is carried on the uppermost sheet supported by the tray 33 is employed.

[Output path]
As shown in FIG. 2, the paper discharge path 31 includes a carry-in port 34 that is continuous with the main body discharge port 16, and a path guide 35 that guides the sheet from the carry-in port 34 toward the paper discharge port 30, and the path guide 35. The conveyance roller 36 is provided. The path guide 35 constitutes a path for conveying the sheet by the upper guide member 35a and the lower guide member 35b. In the figure, Se1 is a carry-in sensor, and Se2 is a paper discharge sensor. Each sensor is constituted by, for example, a photo sensor, a mechanical switch sensor, or the like that detects the leading edge and the trailing edge of the sheet. As shown in FIG. 2, a back conveyance path 44 is branched and disposed in the paper discharge path 31, and the sheet sent from the paper discharge path 31 is transferred toward the processing tray 32.

  The back conveyance path 44 will be described with reference to FIG. The path guide 35 constituting the sheet discharge path 31 is provided with a branch portion 35y (a branch portion of the sheet discharge path), and the back conveyance path 44 transfers the sheet from the branch portion 35y so that the sheet is carried out above the processing tray. Is arranged.

  A path switching unit 45 is provided at the branching portion 35y and guides the sheet rear end to the processing tray 32 side in the state of FIG. 4 after the sheet rear end passes through the branching portion 35y. The illustrated path switching means 45 is configured to switch the path direction by an operating means M3 (motor, electromagnetic solenoid, or other actuator) common to a sheet pressing means 48 described later.

  As shown in FIG. 4, the back conveyance path 44 has a guide structure that is separated from the sheets stacked on the processing tray by a partition guide member 46. This is to avoid rubbing between the already loaded stacked sheets and the loaded sheets when the sheets are carried from the branch portion 35y onto the processing tray. Therefore, the partition guide member 46 may be formed of a resin plate as illustrated, or may be formed by hanging a resin film (for example, a mylar sheet). A sheet carry-in means 40 (a pair of carry-in rollers 40a and 40b, which will be described later) is provided at the paper discharge port 30, and a switch that carries the sheet fed from the paper discharge path 31 back in the opposite direction after being sent in the paper discharge direction. It consists of a back path.

[Sheet loading means]
The sheet discharge port 30 of the sheet discharge path 31 is provided with a sheet carry-in means 40 that conveys the sheet from the back conveyance path 44 toward the processing tray 32. In the illustrated embodiment, the sheet carry-in means 40 is constituted by a pair of rollers (first roller 40a, second roller 40b) that are in pressure contact with each other. The sheet carry-in means 40 is composed of a conveying rotating body (member) such as a roller and a belt that are pressed against each other, and the first roller 40a that engages with the upper surface of the sheet fed from the paper discharge path 31 is connected to the second roller 40b. It consists of lifting rollers that are pressed against and separated from each other.

  As shown in FIG. 4, a first roller 40a is rotatably supported at the distal end portion of an arm member 41 whose base end portion is axially supported by an apparatus frame (not shown). A lift motor M2 is connected to the base end portion of the arm member 41, and the first roller 40a is controlled to move up and down between the operating position indicated by the solid line and the standby position indicated by the broken line by the rotation of the lift motor. At the same time, a drive motor (not shown) is connected to the base end portion of the arm member 41 so that the rotation is transmitted to the first roller 40a by a transmission member (not shown) such as a belt. This drive motor is composed of a stepping motor capable of forward and reverse rotation.

  The second roller 40b is a driven roller (idle roller) and is driven to rotate in accordance with the sheet conveying force driven by the first roller 40a. In particular, the illustrated second roller 40b accommodates the sheet by conveying the sheet from the paper discharge path 31 to the processing tray 32 and then retracting the sheet to the side of the sheet and dropping the sheet onto the processing tray. For this reason, the second roller 40b is configured to be slidable in the direction orthogonal to the sheet conveyance integrally with the partition guide plate 46.

  A back conveyance path 44 is connected to the paper discharge path 31 via a path switching unit 45, and the sheet sent from the paper discharge path 31 is guided toward the processing position on the processing tray by reversing the conveyance direction. Therefore, the second roller 40b is integrally provided with a partition guide plate 46, and guides the sheet along the guide surface of the partition guide plate 46. Then, the second roller 40b and the partition guide plate 46 reverse the conveying direction of the sheet sent from the paper discharge path 31 and send it to the processing tray 32 to stop against the trailing edge regulating means 47. At this time, the interval between the second roller 40b and the trailing edge regulating means 47 is set to be shorter than the length in the sheet conveying direction. This is to make the device compact and compact.

  In such a configuration, the second roller 40b and the partition guide plate 46 need to retract from the sheet after the sheet is conveyed to the processing tray 32. The illustrated apparatus is configured to slide the second roller 40b, which engages with the lower surface side of the sheet from the sheet discharge port 30 toward the processing tray 32, to the sheet side to retract from the sheet. The second roller 40b engages with the lower surface of the sheet while the sheet is sent from the paper discharge path 31 to the rear end regulating member 47 of the processing tray 32, and after the sheet rear end abuts against the rear end regulating member 47, The second roller 40b moves to the sheet side together with the partition guide plate 46 and retracts from the sheet.

[Processing tray configuration]
As shown in FIG. 2, the processing tray 32 forms a step h from the paper discharge port 30 and is disposed below, and supports the sheet fed from the paper discharge port 30 in cooperation with a stack tray 33 described later. To do. The processing tray 32 is formed by molding a synthetic resin or the like, and includes a paper mounting surface 32x. The processing tray 32 is provided with a trailing edge regulating means 47 that regulates the trailing edge of the sheet, a aftertreatment means 39, a sheet pressing means 48, and a stacked sheet alignment means 38, which will be described later. Each configuration will be described later.

[Rear edge regulating means]
As shown in FIGS. 2 and 4, the trailing edge regulating means 47 is configured by a stopper member (sheet edge regulating member) that abuts and regulates the trailing edge of the sheet that has been fed from the paper discharge path 31 with its conveying direction reversed. Yes. The stopper member is configured to align the sheet at a processing position set on the processing tray 32, and the illustrated stopper member is formed of a bent piece (plate) attached to the rear end of the tray.

[Sheet unloading means]
As described above, the sheet carry-in means 40 is disposed on the processing tray 32. Together with the sheet carry-in means 40, sheet carry-out means 68 for carrying out sheets (bundles) to the downstream stack tray 33 is provided. The sheet carry-out means 68 is composed of a conveyance mechanism for carrying out sheets (bundles) processed by a post-processing means 39 described later to the stack tray 33 on the downstream side. In the illustrated apparatus, the sheet carry-out means 68 and the sheet carry-in means 40 are constituted by first, second and third rollers 40 a, 40 b, 68 arranged in the opening 32 y of the processing tray 32. Hereinafter, the configuration will be described.

  As shown in FIG. 4, a first roller 40 a, a second roller 40 b, and a third roller 68 are disposed in the paper discharge outlet 30 from the top to the bottom in this order. The second roller 40b located in the center is placed in a stationary state, and the first roller 40a and the third roller 68 are arranged so as to be movable to a position where they are pressed against and separated from the second roller 40b. Then, the sheet sent from the paper discharge path 31 between the nips of the first roller 40a and the second roller 40b is transferred to the processing tray 32, and the sheet is transferred from the processing tray 32 between the second roller 40b and the third roller 68. Transfer to the stack tray 33.

<First roller>
The first roller 40a engages with the upper surface of the sheet, and is positioned above the sheet fed through the paper discharge path 31, and the first roller 40a is configured by a roller that can move up and down so as to be pressed against and separated from the second roller 40b. Has been. The first roller 40a is configured to be movable up and down between a standby position retracted upward from the sheet movement locus and an operating position in pressure contact with the second roller 40b. This is to wait at a position where the sheet is retracted upward so as not to prevent the sheet fed from the sheet discharge path 31 from being moved, and to lower the first roller 40a to the nip operation position after the leading end of the sheet has passed the second roller 40b. is there.

  The lifting mechanism will be described with reference to FIG. An arm member 41 is swingably provided on the apparatus frame, and a first roller 40a is axially supported at the end of the arm. A lift motor (shift motor) M2 is connected to the base end portion of the arm member 41, and the first roller 40a is pressed against the second roller 40b by forward / reverse rotation of the arm member 41. It moves up and down between the standby position (the broken line position in FIG. 4). An example of the lifting mechanism will be described. A rotating shaft (not shown) of the lifting motor M2 and a support shaft 42 of the arm member 41 are connected by a spring clutch. When the lifting motor M2 rotates in one direction, the spring clutch of the support shaft 42 of the arm member is relaxed, and the arm member 41 is moved from the standby position to the operating position. Further, the spring clutch is contracted by the reverse rotation of the elevating motor M2, and the arm member 41 is moved from the operating position to the standby position, and thereafter, the position is held by hitting a stopper (not shown).

  Further, the support shaft 42 of the arm member is provided with a pulley (not shown). A drive motor (not shown) is connected to the pulley, and the rotation is transmitted to the first roller 40a by a transmission belt or the like. It is supposed to be. Accordingly, the first roller 40a moves up and down between the standby position and the operating position by forward and reverse rotation of the lift motor M2, and rotates to convey the sheet in the paper discharge direction and the counter paper discharge direction by forward and reverse rotation of the drive motor. . The arm member 41 has been described as being swung up and down by a motor, but may be swung by an actuator such as an operating solenoid.

  In such a configuration, when the first roller 40a is in the standby position, the sheet conveyed to the paper discharge port 30 is free without being restrained by the roller, and is rotated while being held by the roller when in the operating position. It will be conveyed in the direction.

<Second roller>
The second roller 40b is an idle roller that is disposed at a position that engages with the first roller 40a and that is driven by the rotation of the first roller 40a. At the same time, the second roller 40b is disposed at a position to engage with a third roller 68 described later. That is, the second roller 40 b is disposed at an optimum position for carrying the sheet sent from the paper discharge path 31 to the processing tray 32 from the back conveyance path 44. At the same time, the second roller 40b is set to a height position for carrying out the sheet from the processing tray 32 to the stack tray 33. The second roller 40b is configured to be slidable in the conveyance orthogonal direction (= the side of the sheet) so as to retreat from the movement locus (path) of the sheet, as will be described later.

  The second roller 40b includes a roller that engages with the peripheral surface of the first roller 40a, and a shaft pin 43 that rotatably supports the shaft. The shaft pin 43 is an alignment member that will be described later (stacked sheet alignment that will be described later). Means 38). The illustrated second roller 40b is a lightweight resin roller such as Delrin. In contrast, the first roller 40a and the third roller 68 are made of a material having a high friction coefficient such as rubber. Thus, the friction coefficient of the first roller 40a> the friction coefficient of the second roller 40b is set, and similarly, the friction coefficient of the third roller 68> the friction coefficient of the second roller 40b. Thus, the reason why the friction coefficient of the second roller 40b is made smaller than that of the other rollers is that the sheet sent from the paper discharge path 31 to the paper discharge port 30 moves while sliding on the peripheral surface of the second roller 40b. This is to reduce the friction load.

<3rd roller>
The third roller 68 is configured to be movable between an unloading position (a broken line position in FIG. 4) in pressure contact with the second roller 40b and an unloading position (a solid line position in FIG. 4) separated from the roller 40b. The carry-out position is set to a height position (step) h from the paper placement surface 32x of the processing tray. This level difference h is set to a height position where the thickness is larger than the maximum bundle thickness loaded on the processing tray and the frictional resistance of the sheet bundle to be carried out is reduced. The frictional resistance in this case is set by experiment so that the sheet bundle is sufficiently smaller than the conveying force for nipping the sheet bundle between the second roller 40b and the third roller 68 and carrying it out.

  The carry-in position of the third roller 68 is set to a height position so that the sheets are stacked in an orderly manner along the paper placement surface 32x of the processing tray. For example, the position is set to either a position built in the processing tray from the paper mounting surface 32x, a position that is the same surface as the paper mounting surface 32x, or a position slightly protruding upward from the paper mounting surface 32x.

  The illustrated third roller 68 is disposed at the outlet end (opening 32y) of the processing tray 32 so as to be built in the inside of the tray, and this roller is attached to the tip of a lifting arm 69 that is pivotally supported by the apparatus frame. Installed. A drive motor (not shown) for imparting rotation to the third roller 68 is connected, and an actuator (not shown) that moves up and down between the raised position and the lowered position is connected to the lift arm 69.

  When the lifting arm 69 is in the lowered position by this actuator (not shown), the third roller 68 is located in the carry-in position and is built in the processing tray. When the elevating arm 69 is in the raised position, the third roller 68 is located at the carry-out position where it is in pressure contact with the second roller 40b. That is, the third roller 68 is built in the processing tray 32 and has a sheet stacked thereon, and when the stacked sheet is unloaded, the sheet is pushed upward and nipped with the second roller 40b. A sheet bundle is transferred from the processing tray 32 to the stack tray 33 by rotating the third roller 68 in the paper discharge direction.

  Further, when the third roller 68 moves up and down between a lower retracted position (a broken line position in FIG. 12) and an upper carry-out position (a solid line position in FIG. 12), the opening 32y of the processing tray 32 is interlocked with the third roller 68. The shutter plate 70 that shields is moved up and down. This is because the stack tray 33 has a “post-processing discharge mode” for storing post-processed sheets (bundles) that are unloaded from the processing tray 32, and a “straight sheet discharge” for storing sheets that are directly unloaded from the discharge path 31. This is because the opening 32y of the processing tray 32 is shielded in the straight sheet discharge mode.

[Stack tray]
A stack tray 33 is arranged on the downstream side of the processing tray 32, and both trays are substantially the same so that the sheet fed from the paper discharge port 30 is bridge-supported by the processing tray 32 at the rear end and the stack tray 33 at the leading end. It is arranged at the height position. The raising / lowering mechanism of the stack tray 33 will be described later.

  In the layout configuration in which the processing tray 32 is disposed with a step h formed downward from the sheet discharge outlet 30 and the stack tray 33 is disposed downstream from the processing tray 32, A sheet carry-in means 40 for carrying the sheets into the processing tray and a sheet carry-out means 68 for carrying out the sheets from the processing tray 32 to the stack tray 33 are arranged. Then, the “sheet carrying-in operation” by the sheet carrying-in means 40 and the “sheet carrying-out operation” by the sheet carrying-out means 68 are performed simultaneously or overlapping with each other and executed in parallel.

  It is impossible, for example, with the structure of the conventional post-processing apparatus, to simultaneously execute the “sheet carry-in” and “sheet carry-out” operations of the processing tray 32. That is, the conventional post-processing apparatus is provided with a roller that can be moved up and down above the processing tray when the sheet is carried from the sheet discharge path onto the uppermost sheet accumulated on the processing tray. Then, after the sheet sent from the paper discharge path enters the uppermost sheet, a conveying method is adopted in which the elevating roller is lowered to reverse the conveying direction. In such a structure in which a sheet sent from the paper discharge path is sandwiched between the lifting roller and the uppermost sheet on the processing tray, the sheet is conveyed to the processing position, and the processing sheet is unloaded by reversing the lifting roller. Loading and unloading cannot be performed at the same time.

  Therefore, in the present invention, as described above, the sheet carry-in means 40 and the sheet carry-out means 68 are disposed at the sheet outlet end (opening) 32y of the processing tray 32, and both the means are operated simultaneously in parallel. In the illustrated apparatus, the sheet carry-in means is constituted by the first roller 40a and the second roller 40b, and the sheet carry-out means is constituted by the third roller 68 and the second roller 40b. The parallel operation of each roller will be described later.

The “post-processing means”, “sheet pressing means”, and “stacked sheet alignment means” of the processing tray described above will be described below.
[Post-processing means]
The post-processing means 39 is disposed on the processing tray 32. The illustrated post-processing means 39 is constituted by a stapler unit that binds a bundle of sheets that are aligned and stacked on the processing tray 32. The description of the stapler unit is omitted because various structures are known, but the blank needle on the straight line is folded over the U-shape, inserted into the sheet bundle, and the tip is folded with the anvil member to bind the staples. Known as a mechanism to

[Sheet presser]
The processing tray 32 is provided with a sheet pressing unit 48 that presses the leading end portion (rear end portion in the paper discharge direction) of the sheet sent from the back conveyance path 44. The sheet pressing unit 48 maintains the posture of the sheet by pressing (pressing) the leading edge of the sheet conveyed back from the paper discharge path 31 onto the processing tray from above the processing tray. This posture holding prevents the sheet posture from being disturbed when the rear end portion of the sheet whose front end portion is abutted and restricted by the rear end regulating means 47 is dropped from the partition guide plate 46.

  FIG. 11 (a) shows the structure thereof. The sheet pressing means 48 is constituted by a swing lever structure whose base end is supported by a frame so as to be swingable by a support shaft 49, and a paper pressure part 48a is provided at the tip. It is formed on a shape that presses the sheet. As shown in FIG. 11A, the sheet pressing means 48 is configured to apply a pressing force to the sheet with an urging spring 50 and reduce the pressing force with an operating means (an actuator such as a solenoid or a motor) M3. Yes.

  The sheet pressing means 48 is provided with a carry-in guide 48 b for guiding the sheet sent from the back conveying path 44 to the trailing edge regulating means 47. This carry-in guide 48b is for reliably guiding a sheet with a curled tip or a thin sheet (a sheet with weak waist) to the rear end regulating means 47. In addition, the form in which the pressure of the paper pressure unit 48a is released by the actuating means M3 includes a form in which the paper pressure part 48a is retracted to a position spaced upward from the uppermost sheet on the processing tray, and a hindrance to the progress of the loaded sheet. Any form that reduces the applied pressure while in contact with the uppermost sheet on the processing tray to such an extent that it does not become possible can be adopted. The specific structure is possible, for example, by adjusting the operating stroke of the operating means M3.

  The above-described sheet pressing means 48 and the above-described path switching means 45 may be configured to be opened / closed or pressed by separate operating means, but the illustrated means is a common operating means M3 and both means are interlocked. It is comprised so that it may do. As shown in FIG. 11A, when the paper pressure unit 48a of the sheet pressing unit 48 presses the sheet, the path switching unit 45 moves the sheet carried out to the sheet discharge port 30 from the rear end side to the back conveying path 44. It is made to interlock | cooperate with the broken-line state of the same figure so that it may guide. Further, when the paper pressure unit 48a is in the non-operating state in which the applied pressure is released, the path switching unit 45 is interlocked with the solid line state in which the sheet is guided from the paper discharge path 31 toward the paper discharge port. For example, this interlocking mechanism is provided with a winding spring on the support shaft 49 so that one-way rotation links the path switching means 45 to the solid line position, and when rotating in the opposite direction, the path switching means 45 moves to the broken line position by its own weight. Configure.

[Loaded sheet alignment means]
Further, the processing tray 32 is provided with a stacked sheet aligning means 38 that matches the width direction of the stacked sheets with the reference point position. This reference point position is preset as a center reference point or a side reference point. The illustrated stacked sheet alignment means 38 includes a pair of left and right alignment members (alignment plates) 51a and 51b disposed on the processing tray, and an alignment motor (shift motor) M4 that moves the alignment members in the sheet width direction. ing. The detailed configuration of the stacked sheet alignment unit 38 will be described later.

[Single sheet alignment mechanism]
A single sheet aligning means 52 that aligns the width direction posture of the sheet with a reference point line (the center line in the drawing) when the sheet sent from the carry-in port 34 is sent to the sheet discharge port 30 is disposed in the sheet discharge path 31. Has been. This is because the position in the width direction (conveyance orthogonal direction) of the sheet coincides with a preset reference point line in the course of transporting the sheet from the carry-in entrance 34 to the delivery exit 30.

  In the present invention, “single sheet aligning means” means means for aligning the postures of sheets conveyed one by one (in the path), and “bundle sheet aligning means” is (stacked on the processing tray). I) Means for aligning the posture of the upper sheet. In either case, “alignment” means that the sheet is aligned with a preset reference point position. A sheet having a different alignment position, a center reference point with the sheet center as a reference point, and the sheet One of the side reference points with the one side edge as a reference point is set. Hereinafter, although the center reference point will be described for convenience of explanation, it may be a side reference point.

  The single sheet aligning means 52 includes a pair of left and right side edge aligning members 53a and 53b that engage with the sheet side edges, and an aligning drive means 54 that moves each side edge aligning member in the sheet width direction. Each of the side edge alignment members 53a and 53b is provided with an alignment surface 53x that engages with the side edge of the sheet, and is slidably fitted to and supported by the apparatus frame (the illustrated one is the path guide member 35).

  As shown in FIG. 6, a slit 35c is formed in the path guide (lower guide member) 35b in a direction perpendicular to the sheet conveyance direction, and side edge alignment members 53a and 53b are fitted in the slit. The side edge alignment members 53a and 53b are provided with alignment surfaces 53x that engage with the sheet side edges. A pair of left and right side edge alignment members 53a and 53b are supported by a slit 35c and endless toothed belts (timing belts) fitted with a pair of toothed pulleys arranged on the back side of the lower guide member 35b. ) 56 is fixed. A shift motor M5a (M5b) is connected to one of the pulleys.

  Accordingly, the side edge alignment members 53a and 53b approach or separate from the sheet center by forward and reverse rotation of the shift motor M5a (M5b). The pair of left and right side edge alignment members 53a and 53b are disposed between the conveyance roller 36 and the sheet carry-in means 40 described above. Note that the pair of left and right side edge alignment members 53a and 53b are driven by the left and right shift motors M5a and M5b, respectively, so that the sheet center approaches or separates from the reference point as shown in the figure.

  In addition, it is also possible to connect the rack provided on each of the left and right side edge alignment members 53a and 53b with a pinion provided on the apparatus frame, and transmit the rotation of the shift motor to this pinion. In this case, the left and right side edge alignment members 53a and 53b move in the opposite directions by the same amount by the rotation of the pinion.

[Scuation correction means]
The paper discharge path 31 is provided with the following skew correcting means 57 together with the single sheet aligning means 52. Then, the sheet width direction is made to coincide with the reference point line by the single sheet aligning means 52, and at the same time, the sheet inclination (skew) is corrected. The skew correction means 57 aligns the leading edge or the trailing edge of the sheet in the conveyance direction with a line (right angle line) perpendicular to the conveyance direction.

  The illustrated skew correcting means 57 includes a pair of engaging claws 58a and 58b spaced in the sheet width direction and a conveying belt (toothed belt) 59 integrally formed with the engaging claws. A conveying belt 59 provided with 58a and 58b is disposed between the conveying roller 36 and the sheet carry-in means 40 described above. Then, the trailing edge of the sheet sent from the conveyance roller 36 (away from the nip point) is engaged with the pair of engagement claws 58a and 58b, and pushed by the movement of the conveyance belt 59 in the paper discharge direction to the engagement claws 58a and 58b. It moves in the direction of the paper exit.

  As shown in FIGS. 4 and 6, a pair of engaging claws 58 a and 58 b having a distance L <b> 5 in the sheet width direction sent through the paper discharge path 31 in the direction of the paper discharge port are formed integrally with the conveyance belt 59. . The transport belt 59 is fitted to the pair of toothed pulleys 60a and 60b, and is rotated in the paper discharge direction by a transport motor (not shown) connected to one of the pulleys. The engagement claws 58a and 58b arranged on the downstream side of the conveying roller 36 are pushed in the sheet discharge direction at two points (or three or more points) by the movement in the sheet discharge direction. At this time, even if the sheet is skewed as shown by a broken line in FIG.

[Stack tray]
Next, the configuration of the stack tray 33 will be described. As shown in FIG. 1, the stack tray 33 is disposed on the downstream side of the processing tray 32. The stack tray 33 includes a paper platform 33a on which sheets are placed, a tray lifting / lowering means 61 that moves the paper platform up and down in accordance with the stacking amount, a level sensor Se3 that detects sheets on the stack tray, The lower limit sensor Se4 detects the lower limit position.

  The stack tray 33 is supported by guide rails 62 arranged on the apparatus frame of the image forming unit A, and is configured to be movable up and down. A winding pulley 63 and a support pulley are disposed at the upper and lower ends of the guide rail 62, and a wire 65 is stretched between the pulleys. A lift motor M6 is connected to the winding pulley 63, and a paper platform 33a is fixed to the wire 65.

  When the lift motor M6 is rotated forward and backward in such a configuration, the winding pulley 63 rotates in the forward and reverse directions, and the wire 65 wound around the pulley 65 moves up and down on the paper platform (tray) 33a in the upward or downward direction. Further, in the level sensor Se3, a paper touch piece 66a and a sensor flag 66b are attached to a swing arm member 66 that pivots upward from the apparatus frame (not shown).

  The swing arm member 66 is provided with an actuator 67 such as an actuating solenoid and a motor so as to pivot from a standby position outside the tray to a detection position above the tray at the timing when the sheet is carried out to the stack tray 33. . The sensor flag 66b at the base end portion of the arm member is detected in a state where the paper touch piece 66a at the front end is in contact with the uppermost sheet.

  The control unit 83 to be described later includes a determination unit that determines whether the stack tray 33 needs to be raised or lowered by a detection signal from the level sensor Se3. By this determination means, the control means 83 controls the height of the paper table to an appropriate position by rotating the lift motor M6 forward and backward by a predetermined amount. The lower limit sensor Se4 is a limit sensor that detects that the paper platform 33a has reached the lower limit position.

[Loaded sheet alignment means]
The processing tray 32 is provided with a stacking sheet aligning means 38 that aligns the position of the stacked sheets in the width direction with the reference point line. The stacked sheet aligning means 38 presets sheets of different sizes in the same manner as the single sheet aligning means 52 described above, and matches the sheet width direction position (paper discharge orthogonal direction) to the reference point line. Therefore, the processing tray 32 is provided with a slit groove 32a in a direction orthogonal to the paper discharge direction, and a pair of left and right alignment members 51a and 51b are slidably fitted in the slit groove 32a.

  The pair of left and right aligning members 51a and 51b are configured so that the left and right approach or separate from each other by the same amount with respect to a preset center line, or with the side line set at one side edge as the reference point. One is fixed and movable so that the other approaches or separates.

  As shown in FIG. 3, the processing tray 32 is provided with a slit groove 32a (hereinafter referred to as “tray groove”) in a direction orthogonal to the paper discharge direction, and a pair of left and right alignment plate members 51a and 51b are provided in the tray groove 32a. It is slidably fitted. Each alignment member 51a, 51b is provided with an alignment surface 51x that engages with the side edges of the sheets stacked on the processing tray. When the left and right alignment surfaces 51x move simultaneously in the approaching direction, the alignment members 51a, 51b are positioned on the processing tray. The stacked sheets are aligned and aligned.

  For this reason, an alignment motor M4 is connected to each alignment member 51a, 51b, and a pinion 64 connected to the motor and a rack 51r formed on the alignment member are engaged with each other. The left and right aligning members 51a and 51b approach or separate from each other by forward and reverse rotation of the aligning motor M4, and when approaching, the sheets are narrowed to match the reference point lines.

[Linkage between partition guide plate and stacked sheet alignment means]
In the above configuration, the partition guide plate 46 provided in the path guide 35 and the back transport path 44 and the processing tray 32 constituting the paper discharge path 31 are arranged in this order in the vertical direction. This is to reduce the size of the apparatus in the paper discharge direction by reversing the paper discharge direction and storing the sheet conveyed from the paper discharge path 31 in the processing tray 32.

  Therefore, the illustrated apparatus moves the partition guide plate 46 disposed above and the stacked sheet alignment means 38 disposed below in the sheet width direction by a common driving means, and shortens the operation stroke of both. It is characterized by doing. The configuration will be described below.

  First, as shown in FIG. 5, the partition guide plate 46 and the second roller 40b in contact with the lower surface of the sheet are respectively formed in a pair of left and right in the sheet width direction. This is to simplify the mechanism in which the left and right guide plates and rollers are retracted to a position away from the sheet side edge. Each of the left and right partition guide plates 46a and 46b is provided with a guide surface 46x that contacts the lower surface of the sheet and guides it on the processing tray, and a roller holder portion 46y that rotatably supports the second roller 40b.

  On the other hand, the alignment members 51a and 51b arranged on the processing tray 32 are provided as a pair on the left and right sides in the sheet width direction as described above, and are movably supported on the processing tray 32 (may be an apparatus frame other than the tray). .

  Therefore, the left and right alignment members 51a and 51b and the partition guide plate 46 are integrated by molding of synthetic resin, for example. A guide surface 46x and a roller holder portion 46y are formed on the partition guide plate 46. The alignment members 51a and 51b are provided with alignment surfaces 51x that engage with the side edges of the sheet. Then, the alignment members 51a and 51b and the partition guide plates 46a and 46b that are opposed to the left and right are integrated with each other on the left and right.

  As a result, the guide surface 46x, the second roller 40b, and the alignment surface 51x face each other in an integrated state. An alignment motor M4 is coupled to the alignment member 51 and the partition guide plate 46 thus configured. The alignment motor M4 moves integrally in the sheet width direction by forward and reverse rotation.

  With such a configuration, the sheet loading unit 40 that conveys the sheet from the sheet discharge port 30 onto the processing tray so as to align the sheets stacked on the processing tray so as to match the reference point line, and the sheet processing A guide surface 46x for guiding onto the tray is configured as a unit, and is attached to the processing tray 32 so as to be movable in the sheet direction, for example, as illustrated. At this time, the width L1 of the sheet loaded into the processing tray 32, the interval L2 between the alignment surfaces (referred to as alignment surface interval), the sheet support interval L3 (referred to as guide surface interval) between the left and right guide surfaces 46x, and the left and right rollers 40b. The sheet engagement interval L4 (referred to as roller surface interval) is shown in FIG.

  In FIG. 5, the left and right width adjusting units D (units in which the partition guide plate 46 and the alignment member 51 are integrated; the same applies hereinafter) reciprocate at a predetermined stroke Ls. Hereinafter, the stroke Ls will be described. The standby position Wp of the width adjusting unit D is set such that the distance L2 between the left and right alignment surfaces is longer (wider) than the width of the maximum size sheet. This is to make the width-adjusting unit D stand by at a position away from the maximum size width of the sheets stacked on the processing tray, and even if a sheet enters the processing tray in a distorted posture, this is obstructed. It is set to an area that should not be. This standby position Wp is set to the home position when the apparatus is initialized.

  The operating position Ap of the width adjusting unit D is set to a position that engages with the side edge of the sheet. This position is set according to the sheet size with a preset sheet center (CL in the drawing) as a reference point. Therefore, even if the sheet carried into the processing tray 32 is sent in a biased manner or skewed and sent, the correct position on the processing tray is determined by the movement of the width adjusting unit D from the standby position Wp to the operating position Ap. Will be set.

  Further, the interval L2 between the alignment surfaces, the guide surface interval L3, and the roller surface interval L4 are configured such that the interval (length) can be changed according to the sheet size L position. The width adjusting unit D is moved at an interval according to the width size. This unit movement is executed by the control means 83 described later. In this case, the roller surface interval L4 and the guide surface interval L3 have substantially the same width, and the positional relationship is shown in FIG. 5, but the outer surface position where the roller or guide surface supports (contacts) the sheet is the roller surface interval L4, the guide surface. This is defined as an interval L3.

  Note that the illustrated apparatus includes the single sheet aligning means 52 that matches the position in the width direction of the sheet with the reference point line in the sheet discharge path 31 described above, and therefore it is necessary to align the position in the width direction of the sheet on the processing tray. If there is no sheet misalignment and whether or not the sheet aligned in the conveying process is stacked on the processing tray 32 and then aligned again is the “use method that does not require alignment of the sheet bundle during bookbinding” or “alignment degree” It may be set depending on whether or not the usage method requires. The control unit 83 to be described later is configured so that the operator can select whether the sheet width direction is aligned only on the sheet discharge path 31 or whether the sheet width direction is aligned on each of the sheet discharge path 31 and the processing tray.

  The width adjusting unit D described above integrally includes the alignment surface 51x, the guide surface 46x, and the sheet support surface 40x of the roller, and reciprocates the width adjusting unit D between the standby position Wp and the operating position Ap. The standby position Wp is set to the outside of the maximum size sheet, and the operation position Ap is set to a position where the alignment surface 51x is aligned with the alignment surface 51x according to the sheet size. In addition, the width adjusting unit can be configured as shown in FIG.

  The width adjusting unit D is characterized in that the sheet guided from the paper discharge port 30 to the processing tray 32 is bent and carried in. In the above-described embodiment, the alignment surface interval L2, the guide surface interval L3, and the roller surface interval L4 are set to substantially the same length. The alignment surface interval L2 is a length that matches the sheet size L1, and the guide surface interval L3 and the roller surface interval L4 are set to dimensions that are set slightly longer than the sheet size L1.

[Different forms of width alignment unit]
A configuration of the width adjusting unit E shown in FIG. The width adjusting unit E is formed as a pair on the left and right sides, and the alignment surface 51x, the guide surface 46x, and the sheet support surface 40x are integrally formed on the left and right. The left and right alignment surface distance L2 is set to be approximately the same length as the sheet size L1. Therefore, in the illustrated example, the guide surface interval L3 and the roller surface interval L4 are set to be shorter than the sheet size L1, and the both sides of the sheet are curved so as to hang downward, and are carried into the processing tray 32 from the sheet discharge outlet 30. It is said.

  In this way, when the sheet is guided to the processing tray 32 along the guide surface 46x, when the sheet is loaded while curving both ends of the sheet, it enters the uppermost sheet on the processing tray by the strength of the waist, and along that surface. It strikes against the rear end regulating means 47. As a result, problems such as bending of the leading edge of the sheet and bending of the skew do not occur.

[Control configuration]
A control configuration of the image forming system shown in FIG. 1 will be described with reference to FIG. The image forming unit A is provided with a control CPU 73, and a ROM 74 storing an operation program and a RAM 75 storing control data are connected to the control CPU. The control CPU 73 is provided with a paper feed controller 76, an image formation controller 77, and a paper discharge controller 78. Along with these, the control CPU 73 is connected with a mode setting means 79 and a control panel 81 having an input means 80.

  The control CPU 73 is configured to select a “print-out mode”, a “jog mode”, and a “post-processing mode”. In the “print-out mode”, the image-formed sheet is stored in the stack tray 33 without finishing. In the “jog mode”, an image-formed sheet is stored in the stack tray 33 in an offset manner so that the sheets can be sorted. In the “post-processing mode”, the sheets on which the images are formed are aligned and collected, and after being bound, are stored in the stack tray 33.

  A post-processing control CPU 83 is provided in the post-processing unit C, and a ROM 84 that stores a control program and a RAM 85 that stores control data are connected to the post-processing unit C. Then, the post-processing control CPU 83 receives from the control CPU 73 of the image forming unit A the upper sheet size, the paper discharge instruction signal, and the mode setting commands for the post-processing mode and the print-out mode.

  The post-processing control CPU 83 includes a paper discharge operation control unit 86, a stacking operation control unit 87 that stacks and stacks sheets on the processing tray 32, a binding processing control unit 88, and a stack control unit 89.

[Description of operation]
The control CPU 73 of the image forming unit A described above executes the following image forming operation in accordance with the image forming program stored in the ROM 74. Similarly, the control CPU 83 of the above-described post-processing unit C executes the following post-processing operation according to the post-processing program stored in the ROM 84.

"Image formation operation"
When the “single-sided printing mode” is selected, the control CPU 73 operates the set size sheet from the cassette 5 and feeds it to the registration roller pair 8. Around this time, the control CPU 73 forms an image on the transfer belt 12 in accordance with predetermined image data. The image data is stored in a data storage unit (not shown) or transferred from an external device connected to the image forming unit A.

  Therefore, the control CPU 73 transfers the toner image formed on the transfer belt 12 to the sheet sent from the registration roller pair 8 by the image forming unit 2 and fixes it by the fixing device 14 on the downstream side. Thereafter, the control CPU 73 sends the image-formed sheet to the paper discharge path 17 and transfers it to a post-processing unit C described later.

When the “double-sided printing mode” is selected, the control CPU 73 executes the above-described operation to form an image on the front side of the sheet, and then reverses the front and back through the duplex path 18 provided continuously with the paper discharge unit 3. Then, the sheet is fed again to the image forming unit 2, formed on the back side of the sheet, and then sent to the paper discharge path 17. At this time, the control CPU 73 causes the post-processing unit C to execute the following operation. The control CPU 83 of the post-processing unit C sends the sheet sent to the paper discharge path 31 based on the detection signal of the sensor that has reached the paper discharge path 31 from the paper discharge path to the back transport path 44.

  Simultaneously with this path switching control, the control CPU 83 moves the first roller 40a from the standby position to the operating position and simultaneously rotates this roller when the leading edge of the sheet is carried into the processing tray 32 from the back conveying path 44. Then, the sheet carried into the processing tray 32 is sent to the downstream side along the processing tray 32 by the rotation of the first roller 40a.

  The above-described control means (post-processing control CPU) 83 executes the following sheet discharge operation in accordance with programs built in the ROM 74 of the image forming unit A and the ROM 84 of the post-processing unit. The illustrated control unit 83 includes a “straight discharge mode (printout discharge mode)”, a “jog discharge mode”, and a “post-processing discharge mode”.

  In the “straight paper discharge mode”, the sheet sent to the carry-in port 34 is carried out from the paper discharge path 31 to the stack tray 33 and stored. In the illustrated apparatus, the sheet fed by the sheet carry-in means 40 through the sheet discharge path 31 is dropped directly from the sheet discharge port 30 onto the stack tray 33 by the first and second rollers 40a and 40b (without being guided to the back conveyance path 44). Let me store. For this reason, the third roller 68 is shifted to a state where it is pressed against the second roller 40 b by the lifting arm 69, and the outlet end (opening) 32 y of the processing tray 32 is shielded by the shutter plate 70. At this time, the third roller 68 is connected to the motor in an idle state by, for example, a one-way clutch.

  In this state, the third roller 68 and the first roller 40a are rotated in the paper discharge direction, and the sheet is carried out from the paper discharge port 30 to the outside. Then, the sheet falls onto the stack tray, the opening 32x at the exit end of the processing tray 32 is covered with the shutter plate 70, and the sheets are stacked and stored on the uppermost sheet.

  In the “jog paper discharge mode”, the sheets sent to the carry-in entrance 34 are separated from the paper discharge path 31 into the stack tray 33 and stored in a state of being aligned. When this mode is executed, the single sheet aligning means 52 is operated at the timing when the trailing edge of the sheet sent to the paper discharge path 31 is detached from the conveying roller 36 with the first roller 40a in the separated position. At this time, the sheet is supported by the path guide 35 of the sheet discharge path 31 in a free state without being nipped by the roller.

  Therefore, the pair of left and right side edge alignment members 53a and 53b perform width alignment. The width alignment position at this time is set to an offset position determined in advance for each sheet alignment. Further, when this mode is executed, the third roller 68 is held at the raised position in pressure contact with the second roller 40b, and the shutter plate 70 covers the tray opening 32x.

  In the “post-processing discharge mode”, the sheets sent to the carry-in port 34 are stacked on the processing tray 32 from the discharge path 31, and are bound and stored in the stack tray 33. The paper discharge operation in this mode will be described with reference to the drawings. FIG. 7A shows a state where a sheet is carried into the paper discharge path 31, and FIG. 7B shows a case where the sheets are aligned in the direction perpendicular to the conveyance by the single sheet aligning means 52 in the path.

[Import operation]
In the initial carry-in state, the sheet is fed into the path from the carry-in entrance 34, the position of the leading end of the sheet is detected by the carry-in sensor Se1, and then carried toward the paper discharge port 30 by the carry roller 36. (Fig. 7 (a))

[Width alignment operation]
The aforementioned control means 83 uses the sheet size signal sent from the image forming unit A and the detection signal detected by the carry-in sensor Se1 as the reference point, and the trailing edge of the sheet separates from the conveying roller 36 to the downstream side. Determine the unloading timing. Based on this determination, the control means 83 operates the single sheet aligning means 52. In the operation of the aligning means, the side edge aligning member 53 is moved from the standby position to the aligning position, and the sheet center is aligned with a preset center line. At the same time, the control means 83 operates the skew correction means 57. The skew correcting means 57 is composed of a conveying belt 59 having an engaging claw 58, and corrects the skew (skew) of the sheet by control of a conveying motor (not shown) connected to the drive pulleys 60a and 60b. (See Fig. 7 (b))

  With such an operation, the sheet is sent to the paper discharge port 30 and the sheet width direction is corrected by the single sheet aligning unit 52, and at the same time, the front and rear in the transport direction are corrected to the correct posture by the skew correcting unit 57. When the trailing edge of the sheet passes through the branching portion 35y of the paper discharge path 31, the control unit 83 moves the first roller 40a from the separation position to the pressure contact position. At the same time, the path switching means 45 is operated to configure a path for guiding the trailing edge of the sheet to the processing tray side.

  Therefore, the control unit 83 reverses the first roller 40a in the direction opposite to the paper discharge direction. Then, the sheet is guided to the back conveyance path 44 from the rear end side via the path switching means 45. One of the rollers (second roller: second roller 40b) and a partition guide plate 46 are disposed in the back conveyance path 44, and the sheet moves along the back conveyance path 44 toward the processing tray 32 by these. At this time, the paper pressure unit 48a of the sheet pressing unit 48 is held at a position floating from the sheet on the processing tray. Further, the carry-in guide 48 b of the sheet pressing unit 48 assists in guiding the sheet from the paper discharge path 31 along the partition guide plate 46 onto the processing tray. (See Fig. 8 (c))

  Next, FIG. 8D shows a state in which the sheet is abutted and aligned from the discharge port 30 to the trailing edge regulating means 47 on the processing tray, and FIG. The operation of retracting the partition guide plate 46 and the second roller 40b engaged with the end portion to the side of the sheet and dropping the trailing end portion of the sheet onto the processing tray is shown.

  In FIG. 8D, the sheet is guided from the back conveying path 44 to the trailing edge regulating means 47 on the processing tray, and the trailing edge is abutted and aligned. At this time, the sheet pressing unit 48 is held in a state in which the paper pressure unit 48 a is lifted from the stacked sheet on the processing tray, and the carry-in guide 48 b guides the sheet toward the rear end regulating unit 47. At this time, the lower surface of the sheet is supported by the partition guide plate 46 and the second roller 40b, and both side edges of the sheet are regulated by the alignment surface 51x.

  In FIG. 9 (e), the control means 83 takes the sheet at the expected time (after a predetermined time has passed from the signal detected by the sheet discharge sensor Se2 as the reference point) when the trailing edge of the sheet comes into contact with the trailing edge regulating means 47. The pressure unit 48a is pressed by the actuator (not shown) of the pressing unit 48 and presses the trailing end of the sheet and holds it on the processing tray. Thereafter, the control means 83 moves the partition guide plate 46 and the second roller 40b from the operating position Ap that engages the sheet to the standby position Wp.

  In FIG. 9 (f), predetermined sheets are stacked and collected on the processing tray 32 by repeatedly executing the above-described operation. Therefore, the control means 83 sends a processing start signal to the post-processing means (stapling apparatus) 39 in response to a job end signal from the image forming unit A. The figure shows the state of the subsequent processing operation. When the subsequent sheet is sent to the paper discharge path 31 during the post-processing operation, the control unit 83 waits the subsequent sheet at the skew correction position. This figure also shows this standby state.

  FIG. 10G shows a state where the sheet bundle is carried out to the processing tray 32 and the subsequent sheets are carried in simultaneously. A state is shown in which the subsequent sheet is nipped by the first roller 40a and the second roller 40b and carried into the processing tray 32, and at the same time, the processed sheet is carried out to the stack tray 33 by the second roller 40b and the third roller 68. In the bundle of processed sheets, a binding needle projects from the sheet surface at the rear end of the sheet shown in FIG. The state is shown in which the leading edge of the carry-in sheet is carried into the binding position so as not to interfere (not rub against each other).

  Timings for starting the operation of the carry-out sheet and for starting the operation of the carry-in sheet are set so that such troubles as jam due to mutual interference between the sheets do not occur. FIG. 11 (h) shows a state in which processed sheets are unloaded from the processing tray 32 and a state in which subsequent sheets are loaded. Thus, high-speed processing and high efficiency can be achieved by simultaneously carrying out the processed sheet and the subsequent sheet into the processing tray 32. When the processing sheet is unloaded and the subsequent sheet is unloaded, the first roller 40a is raised to the upper standby position, and the third roller 68 is lowered to the lower loading position. Thereafter, the second roller 40b retracts from the position where it engages with the lower surface of the sheet to the side of the sheet, and drops and stores the sheet on the processing tray. After this operation, the process returns to the state shown in FIG.

[Output operation]
Next, the control means 83 will be described with reference to the flowchart of FIG. This figure is a conceptual diagram showing the post-processing operation of the image forming system of FIG. 1, and the control means 73 of the image forming unit A sets the finishing processing mode simultaneously with the setting of the image forming conditions. The setting of the finishing processing mode is input from the control panel 81 or the like, for example, whether or not to post-process the sheet on which the operator has formed an image, or whether or not to stack the sheet without post-processing (St01).

  The apparatus shown in the figure selects one of the finishing processing modes from among [printout mode], “jog stack mode”, and “post-processing mode”. The post-processing mode is set to a processing mode in which sheets are aligned and stacked on the processing tray 32 and stapled. Hereinafter, the post-processing mode refers to bookbinding binding finishing processing. As post-processing means, stamp processing or punching processing is known in addition to staple binding processing. Any selection is possible for the present invention.

  The operation when the post-processing mode is set (St02) will be described with reference to the drawings. The control means 83 of the post-processing unit C sets whether to align the sheet width direction in the paper discharge path 31 (St03) and whether to perform the alignment operation in the sheet width direction on the processing tray 32 (St04). It is configured. At least one of the alignment operations is selected. For example, when priority is given to the processing speed, it is possible to set a mode in which sheet alignment in the width direction is not executed.

  The width alignment operation (St03) in the paper discharge path 31 executes the above-described single sheet alignment unit with 2. The operation of aligning the width in the processing tray 32 (St04) is executed by the above-described stacked sheet alignment means 38. When the width alignment operation of the paper discharge path 31 and the width alignment operation of the processing tray 32 are selected in this alignment condition setting (St02), the sheet is positioned in an accurate posture by the post-processing position on the processing tray. Further, when the width alignment operation is executed only in the paper discharge path 31, there is some variation in the sheets set at the processing position, but there is convenience in the case of speedy post-processing.

  Regardless of which alignment operation is selected, the control unit 83 is located on the upper side of the sheet size sent from the image forming unit A and at a preset reference point position (whether it is a centerline reference point or a sideline reference point). The alignment position of the alignment member 3 is set to the position 3x and the operating position Ap and the standby position Wp. Then, the width aligning operation is executed by a timing signal when the sheet is carried onto the processing tray (for example, a predetermined time has elapsed since the signal at which the sheet trailing edge is detected by the sheet discharge sensor Se2).

  Next, the specific operation of the control means 83 will be described with reference to FIG. The control means 83 of the post-processing unit C performs setting of the post-processing mode and matching conditions by the control CPU 73 of the image forming unit A. When receiving the paper discharge instruction signal from the image forming unit A, the control unit 83 moves the first roller 40a to the standby position in the “post-processing mode”. Further, the third roller 68 is moved to a non-operating position (a standby state in which the roller is built in the processing tray).

  The control means 83 causes (1) the engagement claw 58 of the skew correction means 57 to wait in the home position (standby position outside the paper discharge path: the state shown in FIG. 7A). Further, the path switching means 45 is positioned in the paper discharge direction (state shown in FIG. 7). (2) The sheet pressing unit 48 is positioned in a pressure release state in which the paper pressure unit 48a floats from the uppermost sheet on the processing tray. (3) The aligning surface 53x of the single sheet aligning means 52 (side edge aligning member 53) is positioned at a standby position away from the sheet side edge. (4) The alignment surface 53x of the stacked sheet alignment means 38, the sheet, the guide surface 46x of the partition guide plate 46, and the sheet support surface 40x of the second roller are moved to positions that engage with the sheet.

  Thus, the paper discharge initial state is set. In this initial discharge state, substantially the same operation is performed regardless of which finishing mode is selected. Next, a case where the post-processing mode is selected according to FIG.

  The control means 83 executes the paper discharge operation after setting the paper discharge initial state. In this operation, the sheet sent to the paper discharge path 31 is transferred from the back conveying path 44 onto the processing tray, and the sheets are sequentially stacked and stacked. For this reason, the control means 83 rotates the transport roller 36. For the rotation of the conveying roller 36, either a driving motor is activated by a paper discharge instruction signal or a signal by detecting the leading edge of the sheet by the carry-in sensor Se1 is employed.

Next, the control unit 83 operates the single sheet aligning unit 52 at a timing (delay timer) at which the sheet trailing edge separates from the conveying roller 36 in response to a signal that the carry-in sensor Se1 detects the sheet trailing edge. This single sheet aligning means 52 brings the pair of left and right side edge aligning members 53a and 53b described above closer to a reference point line set in advance according to the sheet size by rotating the alignment motors M5a and M5b.

  At this time, the leading end portion of the sheet in the path is carried out from the discharge port 30, and the trailing end portion is at a position separated from the conveying roller 36. At this time, the sheet is in a free state without being constrained by a roller or the like, and the sheet moves without being curled by the movement of the side edge alignment member 53 in the alignment direction, and is aligned with the reference point line. The first roller 40a is held at a standby position retracted upward.

  Concurrently with the alignment in the width direction of the sheet, the control unit 83 drives the conveyance belt 59 to rotate in the paper discharge direction. Then, the engaging claw 58 provided on the belt engages with the rear end of the sheet and moves the sheet in the paper discharge direction. At this time, even if the sheet is skewed, the skew is corrected. After the single sheet aligning means 52 and the skew correcting means 57 are operated in this way, the control means 83 presses the first roller 40a. This operation lowers the first roller 40a to a position where it engages with the second roller (second roller) 40b, and simultaneously rotates it in the direction opposite to the paper discharge direction. At this time, the path switching means 45 is deflected so as to guide the rear end of the sheet to the back conveyance path 44 branched from the paper discharge path 31 as shown in FIG.

  Next, the sheet presser 48 is moved to a pressurized state after an estimated time when the rear end of the sheet is abutted against the rear end restricting unit 47 on the processing tray. This timing is set, for example, as an estimated time for the sheet trailing edge to reach the trailing edge regulating means 47 with a signal that the sheet discharge sensor Se2 detects the sheet trailing edge as a reference point. Further, the sheet pressing means 48 is set so that the paper pressure section 48a presses the sheet and holds its posture by an actuator (not shown) and an urging spring 50.

  With the rear end of the sheet being pressed and held, the partition guide plate 46 and the second roller 40b are retracted to the side of the sheet. In the illustrated embodiment, this operation moves to a standby position away from a position where the alignment surface 51x of the stacked sheet alignment means 38 is engaged with the sheet side edge.

  By repeatedly executing such an operation, a predetermined number of sheets are stacked on the processing tray. Therefore, when the control unit 83 receives a job end signal from the image forming unit A, the control unit 83 operates the post-processing unit 39 (for example, a stapler device). By this operation, the sheet on the processing tray is post-processed (the illustrated one is a binding process).

  Next, the control means 83 moves the third roller 68 from the standby position to the operating position above the processing tray. At the same time, the first roller 40a is rotated in the paper discharge direction. Then, the sheet bundle on the processing tray is carried out to the downstream stack tray 33 while being sandwiched between the third roller 68 and the second roller 40b. The sheets that have been aligned and stacked on the processing tray by the above operation are post-processed by the post-processing unit 39, and then are stacked and stored on the downstream stack tray 33 by the unloading unit.

  In the present invention, the “single sheet aligning means 52” and the “stacked sheet aligning means 38” adopt the same structure as a mechanism for aligning the sheets in the orthogonal direction of conveyance and aligning them with the reference point line. Of course it is possible. As this alignment mechanism, a pair of left and right alignment plates are interlocked to move the same amount in the opposite direction (such as a rack and pinion coupling mechanism), and a mechanism that reciprocates with the rotation of a single motor, and a pair of left and right alignment It is also possible to drive the plates by independent motors, and in this case, it is possible to perform jog conveyance in which the sheet is offset by a predetermined amount and transferred to the stack tray on the downstream side.

  The illustrated apparatus shows a configuration in which the left and right side edge alignment members 53a and 53b are driven by individual drive motors so that the sheet is offset in the conveyance orthogonal direction in the sheet discharge path 31 and is jog-out. Further, the stacked sheet aligning means 38 disposed on the processing tray 32 is configured to reciprocate between a standby position away from the side edge of the sheet and an aligning position where the sheets are aligned in the width direction.

  The left and right aligning members 51a and 51b can be configured to move from the standby position to the aligning position each time a sheet is loaded into the processing tray 32 (each time the sheet is loaded). In this case, since the partition guide plate 46 and the second roller 40b are integrally attached to the alignment member 51, the width adjusting unit D is positioned at the alignment position when the sheet is carried into the processing tray 32, and the sheet After loading, it moves to the standby position and returns to the alignment position. The sheet is aligned by this returning operation.

[Post-processing operation]
In view of this, in the present invention, an operation for carrying a sheet into the processing tray 32 (“sheet carrying-in operation”) and an operation for carrying out a processed sheet from the processing tray 32 (“sheet carrying-out operation”) are performed simultaneously or overlapping. It is characterized by parallel processing. This will be described according to the control flow shown in FIG.

  When the control unit 83 receives a job end signal (St10) from the control CPU 73 of the image forming unit A, the control unit 83 (after the expected time when all the sheets existing in the paper discharge path are carried into the processing tray 32 (paper discharge). After a predetermined time has passed from the sensor Se2; St11), a processing start signal is transmitted to the post-processing means 39 (St12). When the control unit 83 receives a succeeding sheet from the image forming unit A after the transmission of this signal, the control unit 83 detects this with the carry-in sensor Se1. When the carry-in sensor Se1 recognizes the presence of the succeeding sheet or receives a discharge instruction signal (command signal) from the image forming unit A, it recognizes that the succeeding sheet exists (St12).

  After transmitting the processing start signal, the control unit 83 recognizes that there is a subsequent sheet by using a command signal (for example, a discharge instruction signal) from the carry-in sensor Se1 or the image forming unit A. When the succeeding sheet is sent to the paper discharge path 31, the succeeding sheet is put on standby in the path. The apparatus shown in the drawing detects the succeeding sheet by the carry-in sensor Se1 (St13), and then rotates the transport roller 36 (St14) to carry the sheet to the outlet end of the roller. In this position, a pair of left and right side edge alignment members 53 and a conveyor belt 59 are arranged as the skew correction position described above.

  Therefore, the control unit 83 aligns the width direction of the sheet sent from the conveyance roller 36 (St15), waits at that position (St16), and waits for the post-processing of the preceding sheet to end. In this standby, the control means 83 stops the conveying belt 59 at the home position without operating it. As a result, the sheet that has passed through the conveying roller 36 does not receive the conveying force from any of the sheets and stops at that position.

  Next, the post-processing means (stapler unit) 39, which describes the post-processing operation, executes the post-processing operation when receiving a start signal from the control means 83 (St17). For example, in the case of the illustrated stapler unit, the drive motor is rotated by a predetermined amount, the staple is inserted into the sheet bundle, and the leading end is bent. When this series of operations is completed, an end signal is transmitted to the control means 83. Accordingly, when the control means 83 receives the end signal from the post-processing unit C (St18), the control means 83 performs the “sheet carry-out operation” and the “sheet carry-in operation” in parallel.

  The “sheet carry-out operation” is an operation for carrying out processed sheets from the processing tray 32 to the stack tray 33, and the “sheet carry-in operation” carries the subsequent sheets waiting in the paper discharge path 31 toward the processing tray 32. Is the action. Both of these operations are executed by overlapping the carry-out operation and the carry-in portion operation at the same time or in a superimposed manner at the timing recorded in advance in the ROM 74 (St19). The timing setting for this transition process will be described later.

  In the “sheet carry-out operation”, the third roller 68 is moved from the carry-in position to the carry-out position. This movement is performed by swinging an elevating arm 69 supporting the roller by an actuator. At this carry-out position, the third roller 68 is in pressure contact with the second roller 40b, and both rollers rotate in the paper discharge direction by the rotation of the drive motor connected to the third roller 68 (St20). At this time, the third roller 68 pulls the sheet upward from the paper loading surface 32 x of the processing tray 32 by a distance H. Then, the sheet is nipped between the second rollers 40 b and sent toward the stack tray 33.

  In the “sheet carry-in operation”, a subsequent sheet that has already been waiting in the paper discharge path 31 is carried into the processing tray 32. This operation is executed simultaneously or temporally without waiting for the processed sheets to be carried out from the processing tray 32. The conveyance belt 59 (skew correction belt) is rotated from the home position in the conveyance direction, and the engaging claw 58 moves the sheet in the sheet discharge direction. Next, the first roller 40a is lowered from the standby position to the operating position.

  With this operation, the first and second rollers 40a and 40b are pressed against each other, and the sheet is nipped therebetween. Then, the first roller 40a is rotated by a preset rotation amount in the paper discharge direction. At the same time, the control unit 83 shifts the path switching unit 45 to guide the sheet to the back conveyance path 44. At the same time, the first roller 40a rotates in the reverse direction. Then, the sheet is fed from the sheet discharge path 31 to the back transfer path 44 through the sheet discharge outlet 30 and fed to the processing tray 32 from the rear end of the sheet (St21).

[Timing setting]
Next, timing setting for the sheet carry-out operation and the sheet carry-in operation will be described. The conveyance length (path length; Lin) and the conveyance time for transferring the sheet from the standby position of the paper discharge path 31 to the end regulating means 47 of the processing tray 32 can be set as the path length when the apparatus is designed. Similarly, the transported length (tray length; Lout) of the sheet positioned by the end regulating unit 47 and post-processed from the processing tray 32 to the stack tray 33 can be set as the tray size. In the illustrated embodiment, the peripheral speeds of the first roller 40a, the second roller 40b, and the third roller 68 are set at the same position.

  From these conditions, it is possible to set the timing at which (1) the sheet carry-out operation and the sheet carry-in operation are most efficiently executed. For example, when Lin = Lout, it is most efficient to execute the carry-out operation and the carry-in operation at the same time. When Lin> Lout, the carry-out operation is executed after a predetermined time after the carry-in operation is executed. Similarly, when Lin <Lout, the carry-in operation is executed after the carry-out operation is executed.

  Further, (2) in order to execute the sheet carry-out operation and the carry-in operation in parallel, the operation timing is set so that the operations do not interfere with each other. For example, in the case of a stapler device as post-processing means, the leading edge of the succeeding sheet that is carried into the binding needle of the processing sheet is caught, causing a sheet jam. In order to eliminate this problem, sheet unloading is executed in advance, and the subsequent sheet loading operation is set to a timing at which the leading edge of the sheet does not rub against the unloaded sheet (after the unloaded sheet has passed the entry end of the loaded sheet).

  The imming set in this way is stored in the ROM 84 as a data table, for example, as a time lag between the start of the carry-out operation and the start of the carry-in operation according to the sheet size.

A Image forming unit B Image reading unit C Post-processing unit 30 Paper discharge port 31 Paper discharge path 32 Processing tray 32x Paper loading surface 32y Opening portion 33 Stack tray 34 Carry-in port 35 Route guide 35y Branching portion 36 Conveying roller 38 Stacked sheet alignment means 40 Sheet carrying means 40a First roller 40b Second roller 44 Back conveyance path 45 Path switching means 46 Partition guide plate 47 Rear end regulating means 48 Sheet pressing means 51a Alignment member (alignment plate)
51b Alignment member (alignment plate)
52 Single sheet aligning means 53a Side edge aligning member 53b Side edge aligning member 53x Alignment surface 54 Alignment drive means 56 Toothed belt (timing belt)
57 Skew correcting means 58a Engaging claw 58b Engaging claw 68 Third roller (sheet carrying means)
73 Control CPU
83 Control means

Claims (9)

An apparatus for storing a sheet carried out from a paper discharge path in a stack tray after post-processing by a processing tray disposed in a downstream of a paper discharge port,
A paper discharge path having a paper discharge port;
A processing tray disposed downstream of the paper outlet,
A stack tray disposed downstream of the processing tray; and
A sheet carry-in means for carrying the sheet from the paper discharge path to the processing tray;
Sheet unloading means for unloading sheets from the processing tray to the stack tray;
Control means for controlling the sheet carry-in means and the sheet carry-out means;
With
The sheet carrying means is
It is composed of a pair of carry-in rollers that are arranged at the paper discharge port and transfer the sheet sent from the paper discharge path to the processing tray.
The sheet unloading means is
It is arranged between the processing tray and the stack tray, and is composed of a pair of carry-out rollers for transferring the sheet on the processing tray to the stack tray,
When the processing unit carries out the processed sheet from the processing tray and carries in the succeeding sheet, the rotation of the pair of carry-in rollers and the pair of carry-out rollers is temporally or overlapped with each other to carry out and carry out the sheets from the processing tray. A sheet post-processing apparatus that is executed in parallel. The paper discharge path and the processing tray are arranged so that the sheet carried out from the paper discharge port is carried into the processing tray with the conveyance direction reversed.
The processing tray and the stack tray are arranged to carry out the sheet in the same direction as the sheet carried out from the paper discharge path,
First, second, and third rollers that are in pressure contact with each other are disposed at the discharge port,
The first roller and the second roller make a pair of carry-in rollers,
The pair of carry-out rollers is composed of the second roller and the third roller.
The sheet post-processing apparatus according to claim 1, wherein the sheet post-processing apparatus is configured. The first roller, the second roller, and the third roller are arranged in this order from the top to the bottom at the paper discharge port,
3. The sheet post-processing apparatus according to claim 2, wherein the first roller and the third roller are lifting rollers that can be pressed against and separated from a second roller located in the middle. The sheet post-processing apparatus according to claim 3, wherein the third roller is configured to be movable up and down between a position built in the paper loading surface of the processing tray and a position pressed against the second roller. . The control unit rotates the carry-out roller pair in advance, and then rotates the carry-in roller pair simultaneously with the carry-out roller pair to execute the sheet carry-out operation and the sheet carry-in operation on the processing tray in parallel. The sheet post-processing apparatus according to claim 1. The processing tray is provided with stapling means for binding the stacked sheets,
The control means rotates the carry-out roller pair ahead of the carry-in roller pair so that the leading edge of the carry-in sheet does not rub the binding position of the carry-out sheet when performing the sheet carry-out operation and the sheet carry-in operation on the processing tray in parallel. The sheet post-processing apparatus according to claim 1, wherein the sheet post-processing apparatus is used. 3. The sheet post-processing apparatus according to claim 2, wherein the pressure contact force between the second roller and the third roller is set larger than the pressure contact force between the first roller and the second roller. The sheet post-processing apparatus according to claim 2, wherein the friction force of the second roller is set to be smaller than the friction coefficient of the first roller and the third roller. 3. The sheet post-processing apparatus according to claim 2, wherein the second roller is configured to be movable between an engagement position in contact with the lower surface of the sheet and a retracted position away from the sheet in the sheet width direction. .

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