Sheet discharge apparatus, sheet processing apparatus, and image forming system

Abstract

A sheet discharge apparatus includes a stacking portion, a first conveying portion, a detecting portion, a second conveying portion, a third conveying portion, and a control portion. The control portion is configured to perform a discharge operation by causing the sheet discharge apparatus to: reverse a conveying direction of a first sheet conveyed from the first conveying portion to the second conveying portion, and convey the first sheet to the third conveying portion by using the second conveying portion; convey the first sheet toward the second conveying portion by the third conveying portion; and discharge the first sheet and a second sheet to the stacking portion in a state where the first sheet and the second sheet are superimposed on each other by using the second conveying portion. The present application also relates to a sheet processing apparatus and an image forming system.

Description

[0001] This application is a divisional application of the invention patent application filed on November 23, 2021, with application number 202111399374.1 and invention title "Sheet Discharge Device, Sheet Processing Device and Imaging System". Technical Field

[0002] The present invention relates to a sheet discharge device for discharging sheets, a sheet processing device for performing processing on sheets, and an imaging system for forming images on sheets. Background Technology

[0003] Known imaging systems include sheet handling equipment (also called trimmers) that perform processing on sheets on which images have already been formed, such as sorting, binding, or alignment. Sheet handling equipment can be an option for imaging devices such as electrophotographic copiers or laser beam printers. In cases where the sheet handling equipment continuously processes multiple stacks of sheets, if the sheet handling equipment temporarily stops receiving sheets from the imaging device before completing processing the previous stack, the productivity (output) of the imaging system will decrease.

[0004] As a countermeasure, in known methods, when processing is performed on a stack of sheets, one or more sheets received from the imaging device are temporarily held or buffered in the sheet processing device while being stacked on top of each other, and after processing for the previous stack of sheets is completed, the sheets are then stacked as a stack on a processing tray. Japanese Examination Patent Application Publication No. H06-099070 describes a configuration in which two sheets received from the imaging device are held using two transport paths that branch off from each other in a trimmer. The two sheets are then discharged onto a processing tray, with one sheet stacked on top of the other.

[0005] Incidentally, if the sheet conveying speed is increased to further improve the productivity of the imaging system, the sheet will be ejected from the imaging device or sheet handling device with great force. As a result, the stacking position of the sheet ejected to its destination (such as an ejection tray) tends to be easily and unfavorably altered. Summary of the Invention

[0006] The present invention provides a sheet discharge device, a sheet processing device, and an imaging system, which can improve sheet stacking performance while maintaining productivity.

[0007] According to one aspect of the invention, a sheet discharge apparatus includes: a stacking portion on which sheets are stacked; a first conveying portion disposed on a first conveying path extending toward the stacking portion and configured to convey sheets toward the stacking portion; a detection portion configured to output a detection signal in response to sheets passing through the first conveying path; a second conveying portion disposed downstream of the first conveying portion in the first conveying path and configured to reverse the conveying direction of sheets already received by the second conveying portion from the first conveying portion, and convey sheets to a second conveying path, the second conveying path being a path branching from the first conveying path between the first and second conveying portions; and a third conveying portion disposed on the second conveying path and configured to reverse the conveying direction of sheets and... The system includes a sheet conveying section and a control section configured to control a first conveying section, a second conveying section, and a third conveying section. The control section is configured to perform a discharge operation by reversing the conveying direction of the first sheet conveyed from the first conveying section to the second conveying section by causing a sheet discharge device. Based on a detection signal output by a detection section in response to a second sheet conveyed following the first sheet, the system conveys the first sheet to the third conveying section via the second conveying section, conveys the first sheet towards the second conveying section via the third conveying section, and discharges the first sheet and the second sheet to a stacking section via the second conveying section, wherein the first sheet and the second sheet are stacked on top of each other such that the edge portions of the first sheet and the second sheet in their conveying direction are aligned with each other.

[0008] Other features of the invention will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating an imaging system according to a first embodiment of the present disclosure.

[0010] Figure 2 This is a cross-sectional view of the overlay processing portion of the first embodiment.

[0011] Figure 3 This is a hardware configuration diagram of the imaging system in the first embodiment.

[0012] Figure 4 This is a functional block diagram of the imaging system of the first embodiment.

[0013] Figure 5A This is a diagram illustrating the operation of the overlay processing section of the first embodiment.

[0014] Figure 5B This is a diagram illustrating the operation of the overlay processing section of the first embodiment.

[0015] Figure 5CThis is a diagram illustrating the operation of the overlay processing section of the first embodiment.

[0016] Figure 5D This is a diagram illustrating the operation of the overlay processing section of the first embodiment.

[0017] Figure 5E This is a diagram illustrating the operation of the overlay processing section of the first embodiment.

[0018] Figure 5F This is a diagram illustrating the operation of the overlay processing section of the first embodiment.

[0019] Figure 5G This is a diagram illustrating the operation of the overlay processing section of the first embodiment.

[0020] Figure 6 This is a flowchart illustrating an example of the control of the overlay processing section in the first embodiment.

[0021] Figure 7A This is a diagram illustrating a method for controlling the amount of protrusion between sheets in the superposition processing portion of the first embodiment.

[0022] Figure 7B This is a diagram illustrating a method for controlling the amount of protrusion between sheets in the superposition processing portion of the first embodiment.

[0023] Figure 7C This is a diagram illustrating a method for controlling the amount of protrusion between sheets in the superposition processing portion of the first embodiment.

[0024] Figure 8A This is a diagram illustrating a method for controlling the amount of protrusion between sheets in the superposition processing portion of the second embodiment.

[0025] Figure 8B This is a diagram illustrating a method for controlling the amount of protrusion between sheets in the superposition processing portion of the second embodiment.

[0026] Figure 8C This is a diagram illustrating a method for controlling the amount of protrusion between sheets in the superposition processing portion of the second embodiment.

[0027] Figure 8D This is a diagram illustrating a method for controlling the amount of protrusion between sheets in the superposition processing portion of the second embodiment.

[0028] Figure 9 This is a functional block diagram of the imaging system of the second embodiment. Detailed Implementation

[0029] Some embodiments of this disclosure will be described with reference to the accompanying drawings.

[0030] First Embodiment

[0031] Figure 1 This is a schematic diagram of the imaging system 1S as viewed from the front side of the first embodiment. The imaging system 1S includes: an imaging device 1 that forms an image on a sheet; a sheet processing device 4 that processes the sheet on which the image formed by the imaging device 1 performs processing; a relay unit 14 that transfers the sheet from the imaging device 1 to the sheet processing device 4; and an image reading device 2. The sheet as the recording material can be: a paper sheet, such as a plain paper sheet or a thick paper sheet; a plastic film; a cloth sheet; a sheet material, such as a coated paper sheet that has undergone certain surface treatments; a sheet material with a special shape, such as an envelope or index paper sheet; or any of various sheets with different sizes and materials. The operation of each component of the imaging system 1S will be briefly described below, and the operation of the sheet processing device 4 will be described in detail thereafter.

[0032] Imaging apparatus 1 includes: an electrophotographic imaging section 8, which serves as the imaging unit; and a feeding device 6, which feeds sheets one by one into the imaging section 8. The imaging section 8 is a housing in which a photosensitive drum 9, a charger, and a developing unit are arranged as a single unit. The photosensitive drum 9 is the image-carrying component (i.e., the photosensitive element in electrophotography). The charger and developing unit perform electrophotographic processing on the photosensitive drum 9. Furthermore, a scanner unit 15 is disposed above the imaging section 8 as an exposure unit; and a transfer roller 10 is disposed facing the photosensitive drum 9 as a transfer unit. Furthermore, above the transfer roller 10, a fixing device 11, an ejector roller 12a, and a reversal roller 12b are disposed. The fixing device 11 employs a thermal fixing system and may include a cylindrical film, a heater unit, and a pressure roller. The heater unit has a heater and is disposed inside the film. The pressure roller is in pressure contact with the heater via the film.

[0033] Below the imaging section 8, a plurality of feeding devices 6 are provided for feeding sheets. Each of the feeding devices 6 includes a cassette 6a and a feeding unit 6b. The cassette 6a serves as a storage section or sheet memory for storing multiple sheets, and the feeding unit 6b feeds the sheets one by one from the cassette 6a.

[0034] In the imaging section 8, when the imaging device 1 performs an imaging operation, the charger uniformly charges the surface of the photosensitive drum 9, and the scanner unit 15 forms an electrostatic latent image on the surface of the photosensitive drum 9 based on image information by emitting a laser beam onto the surface of the photosensitive drum 9. Then, the electrostatic latent image is developed (i.e. visualized) using toner supplied from the developing unit and used as a developer, thereby forming a toner image on the surface of the photosensitive drum 9.

[0035] In parallel with the operation of the imaging section 8, sheets are fed one after another from the housing 6a of any of the feeding devices 6 by the feed unit 6b toward the alignment roller 7. The alignment roller 7 corrects the skewness of the sheets; then, synchronously with the formation of the toner image performed by the imaging section 8, the sheets are sent to the transfer section between the photosensitive drum 9 and the transfer roller 10. In the transfer section, the toner image is transferred from the photosensitive drum 9 onto the sheet.

[0036] The sheet that has passed through the transfer section is sent to the fixing device 11. In the fixing device 11, while the sheet is held between a film and a pressure roller, the toner on the sheet is heated and pressurized as the sheet passes through the fixing clamping section (which is the clamping section between the heater unit and the pressure roller). In this operation, the toner image is fixed onto the sheet.

[0037] If single-sided printing is performed, the sheet that has passed through the fixing device 11 is discharged from the imaging device 1 via the discharge roller 12a and received by the relay unit 14. If double-sided printing is performed, the sheet with a toner image formed on the first surface and that has passed through the fixing device 11 is guided to the reversing roller 12. The sheet is then folded back by the reversing roller 12 and conveyed again to the alignment roller 7 via the retransmission path 13. The sheet then passes through the transfer section and the fixing device 11, thereby forming an image on the second surface of the sheet opposite to the first surface. Thereafter, the sheet is conveyed to the relay unit 14 via the discharge roller 12a.

[0038] Image reading device 2 is positioned above imaging device 1. Image reading device 2 includes a reading sensor 2s and a document transport section. The reading sensor 2s reads image information from document sheets, and the document transport section transports document sheets one after another to the reading sensor 2s. Imaging device 1 can perform both copying and printing operations. In the copying operation, imaging device 1 forms an image based on the image information obtained by image reading device 2. In the printing operation, imaging device 1 forms an image based on image information already received from an external device.

[0039] In this embodiment, the relay unit 14 is disposed in the space between the imaging device 1 and the image reading device 2 in a vertical direction (i.e., the vertical direction obtained when the imaging system 1S is placed on a horizontal plane) (also referred to as the in-body discharge space). When viewed from the front of the imaging system 1S, the relay unit 14 conveys the sheet discharged from the imaging device 1 toward the sheet processing device 4 in a substantially horizontal direction. The sheet processing device 4 is disposed adjacent to the imaging device 1 on the plane on which the imaging device 1 is disposed. In the relay unit 14, a sheet sensor 52 is provided as a detection part that detects the sheet passing through the relay unit 14. For example, the sheet sensor 52 is a reflective photoelectric sensor that detects the sheet by emitting infrared light into the conveying path and detecting the light reflected by the sheet passing through the conveying path. It should be noted that although the imaging system 1S includes the relay unit 14, by way of example, in this embodiment, the sheet can be directly conveyed from the imaging device 1 to the sheet processing device 4.

[0040] The imaging device 1 also includes a display section 5 (also called an operation section, operation and display section), which is the user interface of the imaging system 1S. The display section 5 has the function of displaying the operating status of the system (such as blockage or malfunction) and the operations required by the user (such as replacing consumables used in the device or removing blocked sheets). By operating the touch panel function or the ten-key numeric keypad function of the display of the display section 5, the user can perform various types of settings and commands on the imaging system 1S.

[0041] It should be noted that the imaging equipment system may not be... Figure 1 The direct transfer system is shown. For example, the imaging device system can be an intermediate transfer system, in which a toner image formed by the imaging portion is transferred onto the sheet via an intermediate transfer member. In another case, the imaging device can be a color imaging device using multiple imaging portions. Furthermore, the imaging mechanism does not have to be an electrophotographic system. For example, the imaging mechanism can use an inkjet printing unit, or it can be an offset printing mechanism.

[0042] Sheet processing equipment

[0043] The sheet processing equipment 4 includes a sheet processing section 71 for processing sheets. The sheet processing equipment 4 has the function of receiving sheets from the imaging device 1, then processing the sheets, and discharging the sheets as products. The sheet processing equipment 4 can receive sheets from the imaging device 1; and discharge the sheets as products without performing any processing on the sheets.

[0044] In the sheet processing apparatus 4, a receiving path 81, an internal discharge path 82, a first discharge path 83, and a second discharge path 84 are configured as transport paths for conveying the sheet. Furthermore, in the sheet processing apparatus 4, an upper discharge tray 25 and a lower discharge tray 37, protruding from the apparatus body 4A, are configured as destinations for sheet discharge. The apparatus body 4A is a housing in which the receiving path 81, the internal discharge path 82, the first discharge path 83, and the second discharge path 84 are provided. The receiving path 81 is a transport path for receiving and conveying the sheet from the imaging device 1. The internal discharge path 82 is a transport path for conveying the sheet toward the sheet processing section 71. The first discharge path 83 is a transport path for discharging the sheet onto the upper discharge tray 25. The second discharge path 84 is a transport path for discharging the sheet onto the lower discharge tray 37. In this embodiment, receiving path 81 and first discharge path 83 serve as a first conveying path extending toward upper discharge tray 25 (which serves as a stacking portion, the first stacking portion), and inner discharge path 82 serves as a second conveying path branching from the first conveying path. Second discharge path 84 serves as a third conveying path extending from sheet processing section 71 toward lower discharge tray 37, which serves as the second stacking portion.

[0045] On the receiving path 81, an inlet roller 21, a branching pre-roller 22, and an inlet sensor 27 are provided. On the first discharge path 83, a discharge and reversing roller 24 is provided as a reversing and conveying unit. On the internal discharge path 82, an internal discharge roller 26, an intermediate conveying roller 28, an ejection roller 29, and an intermediate stacking pre-sensor 38 are provided. On the second discharge path 84, a stack discharge roller 36 is provided. The branching pre-roller 22 is the first conveying section of this embodiment, the discharge and reversing roller 24 is the second conveying section of this embodiment, and the internal discharge roller 26 is the third conveying section of this embodiment. Each of the inlet roller 21, branching pre-roller 22, discharge and reversing roller 24, internal discharge roller 26, intermediate conveying roller 28, ejection roller 29, and stack discharge roller 36 is a roller pair. The outer peripheral surface of one element of the roller pair abuts against the outer peripheral surface of the other element of the roller pair to form a clamping portion through which the sheet is conveyed while being clamped by the roller pair.

[0046] Each of the inlet sensor 27 and the intermediate stack front sensor 38 is an example of a detection section positioned at a predetermined detection location in the conveyor path of the sheet handling apparatus, and detecting sheet material passing through the conveyor path at that location (i.e., the sensor outputs a detection signal in response to sheet material passing through the conveyor path). For example, each of the inlet sensor 27 and the intermediate stack front sensor 38 is a reflective photoelectric sensor that detects sheet material by emitting infrared light into the conveyor path and detecting the light reflected by the sheet material passing through the conveyor path. In another case, the sheet detection section may consist of a marker protruding in the conveyor path and a photoelectric sensor such as a light interruptor. In this case, when the sheet material abuts the marker, the marker pivots, and the pivoting of the marker is detected by the photoelectric sensor.

[0047] The sheet conveying path in the sheet processing apparatus 4 will be described below. The sheet, which has been conveyed from the imaging apparatus 1 via the relay unit 14, is received by the inlet roller 21 of the sheet processing apparatus 4 and then conveyed to the branch front roller 22 via the receiving path 81. The inlet sensor 27 detects the sheet at a detection position between the inlet roller 21 and the branch front roller 22. The branch front roller 22 receives the sheet from the inlet roller 21 and conveys the sheet toward the first discharge path 83.

[0048] It should be noted that at a predetermined moment after the inlet sensor 27 detects the trailing edge of the sheet passing through, the branch front roller 22 increases the sheet conveying speed from the conveying speed generated by the relay unit 14 to a speed faster than that speed. Alternatively, the sheet conveying speed generated by the inlet roller 21 can be set to be faster than the conveying speed generated by the relay unit 14, and the sheet conveying speed can be increased by the inlet roller 21 located upstream of the branch front roller 22. In this case, preferably, a one-way clutch is provided between the conveying roller of the relay unit 14 and the motor driving the conveying roller, so that the conveying roller idles when the sheet is pulled by the inlet roller 21.

[0049] To discharge the sheet to the upper discharge tray 25, the discharge and reversing roller 24 receives the sheet from the branch front roller 22 and discharges the sheet to the upper discharge tray 25. In this case, at a predetermined time after the trailing edge of the sheet passes the branch front roller 22, the discharge and reversing roller 24 is decelerated to a predetermined discharge speed.

[0050] To discharge the sheet to the lower discharge tray 37, the discharge and reversing roller 24 receives the sheet from the branch front roller 22, folds the sheet back, and conveys the sheet to the inner discharge path 82. That is, the discharge and reversing roller 24 first conveys the sheet towards the outside of the sheet handling equipment 4 in the discharge direction, and then conveys the sheet in the opposite direction by reversing the rotation direction of the discharge and reversing roller 24 before the trailing edge of the sheet passes the discharge and reversing roller 24 in the discharge direction. A check guide 23 is provided in the branch section (between the branch front roller 22 and the discharge and reversing roller 24), which is located upstream of the discharge and reversing roller 24 in the discharge direction, and in which the inner discharge path 82 branches from the receiving path 81 and the first discharge path 83. The check guide 23 functions as a guide (control member, backflow check valve, or one-way guide) to prevent the sheet folded back by the discharge and reversing roller 24 from moving backward toward the receiving path 81. In other words, after the trailing edge of the sheet passes the check guide 23 in the discharge direction, the sheet is reversed by the discharge and reversal rollers 24.

[0051] An internal discharge roller 26, an intermediate conveyor roller 28, and an ejector roller 29, positioned on the internal discharge path 82, convey the sheet material sent from the discharge and reversing roller 24 toward the sheet handling section 71, such that the sheet material is sequentially conveyed from one roller to another. An intermediate stacking pre-sensor 38 detects the sheet material at a location between the intermediate conveyor roller 28 and the ejector roller 29. For example, the intermediate stacking pre-sensor 38 is a reflective photoelectric sensor that detects the sheet material by emitting infrared light into the conveying path and detecting the light reflected by the sheet material passing through the conveying path.

[0052] The sheet processing apparatus 4 includes a stacking processing section 4B, which includes a discharge and reversal roller 24 and an internal discharge roller 26. The sheet processing apparatus 4 causes the stacking processing section 4B to stack multiple sheets conveyed from the imaging apparatus 1 one by one. Operating the stacking processing section 4B of this embodiment, a first sheet conveyed via receiving path 81 is held in an internal discharge path 82 by the discharge and reversal roller 24 and the internal discharge roller 26, and then a second sheet conveyed via receiving path 81 is stacked on top of the first sheet. The stacking processing section 4B has the function of discharging the stacked sheets to an upper discharge tray 25 (stacking and discharging function) and the function of conveying the stacked sheets to the sheet processing section 71 (buffering function). The detailed configuration and operation of the stacking processing section 4B will be described later.

[0053] The sheet processing section 71 receives multiple sheets from the internal discharge path 82, aligns the sheets, and then performs a binding process for binding the stack of sheets at predetermined positions. The sheet processing section 71 includes a stapler 50, an upper intermediate stack guide 31, and a lower intermediate stack guide 32. The stapler 50 serves as the processing section, and the upper intermediate stack guide 31 and the lower intermediate stack guide 32 constitute an intermediate stack section (i.e., a processing tray) in which the sheets to be processed are stacked.

[0054] A vertical alignment reference plate 39 is positioned as a reference member at the downstream end of the sheet processing section 71 in the conveying direction of the ejector roller 29. Therefore, the edge portion of the sheet in the conveying direction abuts against the vertical alignment reference plate 39, aligning the stacked sheets in the longitudinal direction (conveyor direction). A semi-circular roller 33 is positioned downstream of the pressing guide 56 and is rotatably supported by the intermediate stack upper guide 31.

[0055] The semi-circular roller 33 is a moving member (also referred to as a paddle-shaped member or a conveying member) that brings the sheet that has passed through the ejector roller 29 against the vertical alignment reference plate 39. Specifically, after the trailing edge of the sheet passes the intermediate stack pre-sensor 38, the semi-circular roller 33 conveys the sheet toward the vertical alignment reference plate 39 at a predetermined moment. The contact pressure of the semi-circular roller 33 on the sheet is set such that the semi-circular roller 33 slides on the sheet while the sheet is in contact with the vertical alignment reference plate 39. Note that the flexible pressing guide 56 is fixed to the intermediate stack upper guide 31. The pressing guide 56 applies a predetermined pressure to press down on the sheet located in the sheet handling section 71 to prevent the sheet from floating. In addition, a stacking pressure mark 30 is provided downstream of the ejector roller 29 and is rotatably supported. The stacking pressure mark 30 prevents the trailing edge of the sheet stacked on the sheet handling section 71 from rising, so that the trailing edge does not interfere with the leading edge of the subsequent sheet discharged from the ejector roller 29.

[0056] When a predetermined number of sheets (i.e., multiple sheets to be processed into one product) are aligned in the intermediate stacking section, the sheets are stapled by stapler 50. Then, the stack discharge guide 34, which acts as a pushing member driven by guide drive section 35, passes through from... Figure 1 The waiting position shown moves toward the stack discharge roller 36 in the direction of stack discharge (stack discharge direction) to push the sheet stack out of the intermediate stacking section. When the leading edge of the sheet stack in the stack discharge direction reaches the stack discharge roller 36, the stack discharge guide 34 stops and then returns to the waiting position. The stack discharge roller 36, which serves as the discharge section (fourth conveying section), receives the sheet stack from the stack discharge guide 34 and discharges the sheet stack to the lower discharge tray 37.

[0057] The upper discharge tray 25 and the lower discharge tray 37 are vertically movable relative to the housing of the sheet handling apparatus 4. Furthermore, sheet sensors 51 and 53 are respectively disposed on the upper discharge tray 25 and the lower discharge tray 37 for detecting sheets on trays 25 and 37. Each of the sheet sensors 51 and 53 is a reflective photoelectric sensor that detects sheets by emitting infrared light into the space above the stacked surfaces of the trays and detecting the light reflected by the sheets. Additionally, the sheet handling apparatus 4 includes a sheet surface detection sensor that detects the position of the upper surface of the sheets stacked on the upper discharge tray 25 (i.e., the height of the sheet stack) and a sheet surface detection sensor that detects the position of the upper surface of the sheets stacked on the lower discharge tray 37 (i.e., the height of the sheet stack).

[0058] If the sheet surface detection sensor detects a sheet, the corresponding upper discharge tray 25 or lower discharge tray 37 moves downward along the A2 or B2 direction. If the sheet sensor 51 or 53 detects that the sheet stacked on the upper discharge tray 25 or lower discharge tray 37 has been removed, the upper discharge tray 25 or lower discharge tray 37 moves upward along the A1 or B1 direction. Depending on the amount of stacked sheet, lifting control is performed on the upper discharge tray 25 and lower discharge tray 37 such that the top surface of the sheet stacked on the upper discharge tray 25 is vertically lower than the discharge and reversing roller 24, and the top surface of the sheet stacked on the lower discharge tray 37 is vertically lower than the stack discharge roller 36. In this embodiment, both the upper discharge tray 25, used as the first stacking portion, and the lower discharge tray 37, used as the second stacking portion, are driven by a motor. However, each of the upper discharge tray 25 and lower discharge tray 37 can be moved vertically by a pushing portion such as a spring.

[0059] It should be noted that the stapler 50 described above is an example of a processing unit. As an example, a sorting unit that performs sorting processing or a saddle stitching unit that performs saddle stitching can be set as a processing unit.

[0060] Overlay processing section

[0061] Figure 2This is an enlarged view of the superimposed processing section 4B. The sheet conveying path (receiving path 81) between the inlet roller 21 and the branch front roller 22 is formed by the inlet upper guide 40 and the inlet lower guide 41. The sheet conveying path (internal discharge path 82) between the inner discharge roller 26 and the intermediate conveying roller 28 is formed by the inner discharge upper guide 46 and the inner discharge lower guide 47. The reversing upper guide 42 is a conveying guide formed between the branch front roller 22 and the discharge and reversing roller 24, and is formed on the same side as the inlet upper guide 40 used for guiding the sheet. The reversing lower guide 43 is a conveying guide formed between the discharge and reversing roller 24 and the inner discharge roller 26, and is formed on the same side as the inner discharge lower guide 47 used for guiding the sheet. Therefore, the first discharge path 83 is formed by the reversing upper guide 42 and the reversing lower guide 43.

[0062] The sheet conveyed by the inlet roller 21 is guided to the branch front roller 22 via the upper inlet guide 40 and the lower inlet guide 41. An inlet sensor 27 is disposed on the upper inlet guide 40. The inlet sensor 27 may be a reflective photoelectric sensor that detects the sheet at the detection position by emitting infrared light into the receiving path 81 and detecting the light reflected by the sheet. In this case, a hole is formed in the portion of the lower inlet guide 41 facing the inlet sensor 27 to prevent reflection of infrared light when no sheet passes through the inlet sensor 27. The size of the hole is equal to or larger than the diameter of the dot beam from the inlet sensor 27.

[0063] A check guide 23 is disposed in the portion downstream of the branch front roller 22, wherein the receiving path 81 and the internal discharge path 82 branch from the first discharge path 83. The check guide 23 is supported such that it can rotate relative to the internal discharge upper guide 46 via a rotation shaft 23a. Furthermore, the check guide 23 is always supported by a spring (not shown) along the C2 direction (…). Figure 2 Push in the clockwise direction (in the middle) Figure 2 The position shown is where the leading edge of the check guide 23 overlaps with the reversing upper guide 42 when viewed from the direction extending from the rotation axis 23a (i.e., the sheet width direction). Furthermore, the spring constant of the aforementioned spring is set such that when the sheet fed from the branch front roller 22 abuts against the check guide 23, the check guide 23 overcomes the spring's pushing force and moves towards the C1 direction (…). Figure 2 (in the counterclockwise direction). Therefore, the check guide 23 allows the sheet conveyed from the branch front roller 22 toward the discharge and reversing roller 24 to pass through the check guide 23. After the trailing edge of the sheet conveyed through the receiving path 81 passes the check guide 23, the check guide 23 pivots in the C2 direction and prevents the sheet from moving backward from the discharge and reversing roller 24 to the branch front roller 22.

[0064] The discharge and reversing roller 24 consists of an upper roller 24a and a lower roller 24b. In this embodiment, each of the upper roller 24a and the lower roller 24b is driven, and the rotation of the upper roller 24a and the rotation of the lower roller 24b are always synchronized with each other.

[0065] The discharge and reversing rollers 24 can be brought into contact with each other (closing operation) and separated from each other (opening operation) via the plunger solenoid 45. Specifically, one end of the separating rod 44 is connected to the roller shaft of the upper roller 24a, and the separating rod 44 is supported such that it can rotate relative to the reversing upper guide 42 on the rod pivot shaft 44a. The solenoid connecting shaft 44b, connected to the other end of the separating rod 44, is connected to the plunger of the plunger solenoid 45.

[0066] When the plunger solenoid 45 is powered, the plunger is pulled magnetically in the D1 direction, and the separating rod 44 rotates in the E1 direction. As a result, the discharge and reversing rollers 24 are separated (that is, the clamping portion of the roller pair is open). When the power supply to the plunger solenoid 45 is cut off, the upper roller 24a is pushed against the lower roller 24b by the pushing force of the pressing spring 48 connected to the roller shaft of the upper roller 24a. As a result, the discharge and reversing rollers 24 are in the abutting state (that is, the clamping portion is closed). When the upper roller 24a is pushed against the lower roller 24b by the pushing force of the pressing spring 48, the separating rod 44 rotates in the E2 direction due to the movement of the upper roller 24a, and the plunger of the plunger solenoid 45 moves in the D2 direction. It should be noted that the mechanism for opening and closing the discharge and reversing rollers 24 can be another mechanism. For example, the separating rod 44 can be oscillated by a cam that is rotated by the driving force of a motor.

[0067] The internal discharge roller 26 is a pair of rollers arranged adjacent to the discharge and reversing roller 24 in the internal discharge path 82 along the sheet conveying direction, and it is capable of rotating in both forward and reverse directions. That is, the internal discharge roller 26 can convey the sheet in both the direction extending from the discharge and reversing roller 24 toward the sheet processing section 71 (hereinafter referred to as the G1 direction) and the direction extending from the sheet processing section 71 toward the discharge and reversing roller 24 (hereinafter referred to as the G2 direction).

[0068] Hardware configuration

[0069] Next, we will refer to Figure 3 The hardware configuration of the imaging system 1S in this embodiment is described. Figure 3 The main illustration shows the hardware configuration of the sheet processing device 4 in the imaging system 1S. The video controller 601 controls the entire imaging system 1S, including the imaging device 1 and the sheet processing device 4. The engine control unit 602 controls the imaging device 1.

[0070] The main control unit 603 controls the sheet processing equipment 4. Signal line 604 is a signal line for serial command transmission; via this signal line, the video controller 601 transmits commands to the engine control unit 602 via serial communication. Signal line 605 is a signal line for serial command transmission; via this signal line, the video controller 601 transmits commands to the main control unit 603 via serial communication. Signal line 606 is a signal line for serial status transmission; via this signal line, the engine control unit 602, in response to a command, transmits status data to the video controller 601 via serial communication. Signal line 607 is a signal line for serial status transmission; via this signal line, the main control unit 603, in response to a command, transmits status data to the video controller 601 via serial communication. To perform imaging operations, the video controller 601 controls the engine control unit 602 and the main control unit 603 by transmitting serial commands to and receiving status data from them. In this way, when operating an imaging system 1S in which multiple devices are connected to each other, the video controller 601 controls the devices and manages their status to maintain consistency in device operation.

[0071] The main control section 603 includes a CPU 608 and RAM 609. The CPU 608 controls various operations of the sheet processing equipment 4, and the RAM 609 temporarily stores control data required for operating the sheet processing equipment 4. The main control section 603 also includes a non-volatile ROM 610, which stores programs and control tables required for operating the sheet processing equipment 4. The main control section 603 also includes a communication section 611, a system timer 612, and I / O ports 613. The communication section 611 performs communication with the video controller 601. The system timer 612 generates timings required for various types of control. The I / O ports 613 send / receive control signals to / from various units of the sheet processing equipment 4. The main control section 603 is a control circuit in which the above components are interconnected via a bus 614.

[0072] Input signals from inlet sensor 27 are transmitted to main control unit 603 via input circuit 615; input signals from sheet sensor 51 of upper discharge tray 25 are transmitted to main control unit 603 via input circuit 626; and input signals from sheet sensor 53 of lower discharge tray 37 are transmitted to main control unit 603 via input circuit 628. Furthermore, control signals from main control unit 603 are transmitted via drive circuits 618, 619, 620, 621, or 623 to inlet motor 641, branch pre-motor 642, discharge and reverse motor 643, internal discharge motor 644, or plunger solenoid 45. This operation drives and controls each actuator.

[0073] Function block

[0074] Next, we will refer to Figure 4 The functional blocks of this embodiment are described. Figure 4 The main control unit 603 shown has the function of performing sheet conveying operations of the sheet processing equipment 4. The main control unit 603 has at least the functions of a communication unit 611, a system timer 612, a sheet conveying control unit 701, a sensor control unit 720, a motor control unit 721, and a solenoid control unit 722.

[0075] The sensor control unit 720 receives signals from the inlet sensor 27 and the sheet sensor 51 of the upper discharge tray 25, and sends the signals to the sheet conveying control unit 701. The sheet conveying control unit 701 includes a stacking conveying control unit 711 and a sheet quantity control unit 712. The sheet conveying control unit 701 controls the motor control unit 721 and the solenoid control unit 722 based on the signals sent from the sensor control unit 720, thereby operating the stacking processing unit 4B, the upper discharge tray 25, and the lower discharge tray 37. The stacking conveying control unit 711 controls the conveying of sheets to the stacking processing unit 4B and the upper discharge tray 25. Specifically, the stacking conveying control unit 711 controls the conveying of sheets based on the signals sent from the sensor control unit 720, while simultaneously controlling the position of the sheets.

[0076] When performing a job of continuously forming images on multiple sheets, the sheet quantity control unit 712 manages the number of sheets stacked in the overlay processing unit 4B. Based on the maximum sheet quantity, the currently stacked sheet quantity, and sheet information, the sheet quantity control unit 712 determines whether to convey the stacked sheets towards the upper discharge tray 25 or the sheet processing unit 71, or to stack subsequent sheets on top of the stacked sheets. The maximum sheet quantity is the number of sheets that can be stacked together by the overlay processing unit 4B.

[0077] It should be noted that the inlet motor 641 drives the inlet roller 21, the branching motor 642 drives the branching roller 22, and the discharge and reversing motor 643 drives the discharge and reversing roller 24. Furthermore, the internal discharge motor 644 drives the internal discharge roller 26, and the plunger solenoid 45 drives the separating rod 44. The operation of the components driven by the aforementioned motors will be described in detail later.

[0078] Superimposed discharge operation

[0079] refer to Figures 5A to 5FThe following describes the operation (overlay discharge operation) in which the overlay conveying control section 711 overlays multiple sheets and discharges them from the overlay processing section 4B. In the following text, the sheet sent from the imaging device 1 to the sheet processing device 4 for the overlay discharge operation (first sheet) is referred to as sheet S1, and the sheet sent from the imaging device 1 to the sheet processing device 4 for the overlay discharge operation (second sheet) is referred to as sheet S2. Furthermore, the pre-acceleration conveying speed (i.e., the conveying speed generated by the relay unit 14) generated by the branch front roller 22, the discharge and reversal roller 24, and the internal discharge roller 26 is represented by V1, and the post-acceleration conveying speed is represented by V2.

[0080] Typically, in the stacking discharge operation, the discharge and reversing roller 24 (second conveying section) reverses the conveying direction of the sheet S1 sent from the branch front roller 22 (first conveying section) and conveys the sheet S1 to the inner discharge roller 26 (third conveying section). Figures 5A to 5D Subsequently, if the inlet sensor 27 (detection section) outputs a detection signal in response to the sheet S2 being conveyed along with the sheet S1, the inner discharge roller 26 (third conveying section) conveys the sheet S1 toward the discharge and reversing roller 24 (second conveying section). Figure 5E Then, the discharge and reversing roller 24 (second conveying section) discharges sheets S1 and S2 onto the upper discharge tray 25 (stacked section), wherein sheets S1 and S2 are stacked on top of each other with the edge portions of sheet S1 in the conveying direction aligned with the edge portions of sheet S2 in the conveying direction. Figure 5F ).

[0081] exist Figure 5A In the process where the trailing edge of the preceding sheet S1 passes the inlet sensor 27, the speeds of the branch front roller 22 and the discharge and reversing roller 24 increase from speed V1 to speed V2. Due to the increased conveying speed of sheet S1, even if the imaging device 1 is a high-performance machine with high throughput, the required sheet distance for folding back between sheet S1 and the subsequent sheet S2 can be ensured. However, if sheets S1 and S2 do not collide with each other, the conveying speed at the inlet sensor 27 may not increase. In this case, the conveying speed in the overlay processing section 4B can remain constant at V1. Figure 5A In the middle, the discharge and reversing roller 24 conveys the sheet S1 along the F2 direction.

[0082] exist Figure 5BIn the process, after the trailing edge of sheet S1 passes the inlet sensor 27 and moves a predetermined distance, at the moment when the trailing edge of sheet S1 has passed the check guide 23, the conveying of sheet S1 is temporarily stopped. The predetermined distance is determined such that when the trailing edge of sheet S1 has moved a predetermined distance in the F2 direction, the trailing edge of sheet S1 has passed the check guide 23, but has not reached the clamping portion of the discharge and reversing roller 24.

[0083] exist Figure 5C In the middle, the discharge and reversing roller 24 changes its rotation direction and conveys the sheet S1 in the F1 direction at a speed V2. The inner discharge roller 26 is driven before the leading edge of the sheet S1 in the F1 direction reaches the inner discharge roller 26, and further conveys the sheet S1 in the G1 direction.

[0084] exist Figure 5D In this process, after the leading edge of sheet S1 passes through the internal discharge roller 26 along the G1 direction (F1 direction), the conveying of sheet S1 is stopped at a position reached by sheet S1 after being conveyed a predetermined distance, while sheet S1 is clamped by the internal discharge roller 26. The predetermined distance is less than the distance that the leading edge of sheet S1 can move to reach the intermediate conveying roller 28. At the moment sheet S1 is clamped by the internal discharge roller 26, the upper roller 24a of the discharge and reversing roller 24 moves along the E1 direction via the separating rod 44, causing the upper roller 24a to separate from the lower roller 24b. It should be noted that the discharge and reversing roller 24 is driven so that the upper roller 24a separates from the lower roller 24b before the leading edge of subsequent sheet S2 reaches the discharge and reversing roller 24.

[0085] exist Figure 5E In the process, after the trailing edge of the subsequent sheet S2 has passed the inlet sensor 27, the speeds of the branch front roller 22 and the discharge and reversing roller 24 increase to speed V2, as increased for the previous sheet S1. At a predetermined time T_wait elapsed since the trailing edge of sheet S2 passed the inlet sensor 27, the inner discharge roller 26 begins to rotate again and conveys sheet S1 toward the discharge and reversing roller 24 in the G2 direction. The predetermined time T_wait will be described later. At the moment when the relative speed of sheet S1 relative to sheet S2 (or the relative speed of sheet S2 relative to sheet S1) becomes zero, the upper roller 24a of the discharge and reversing roller 24 is driven in the E2 direction and abuts against the lower roller 24b, causing the discharge and reversing roller 24 to simultaneously clamp both sheet S1 and sheet S2. At this time, the leading edges of sheet S1 and sheet S2 in the F2 direction are aligned with each other. Furthermore, the rotational speed of the discharge and reversal roller 24 is adjusted so that the rotational speed becomes equal to the conveying speed V2 of the sheet S1 and the sheet S2 before the sheet S1 and the sheet S2 are clamped by the discharge and reversal roller 24.

[0086] exist Figure 5FIn the process, when the trailing edge of sheet S2 passes the anti-return guide 23, sheets S1 and S2 become a sheet stack S', wherein the leading edges of sheet S1 and sheet S2 in the F2 direction are aligned with each other, and the trailing edges of sheet S1 and sheet S2 in the F2 direction are aligned with each other. If the destination to which the sheet stack S' is discharged is set as the upper discharge tray 25, the sheet stack S' is discharged to the upper discharge tray 25 by the discharge and reversing rollers 24 while maintaining a speed V2.

[0087] exist Figure 5G If the destination to which the sheet stack S' is discharged is set to the lower discharge tray 37, then when the trailing edge of the sheet that is the last sheet added to the sheet stack S' (i.e., sheet S2 in this embodiment) passes the check guide 23, the discharge and reversing roller 24 is temporarily stopped. Then, the sheet stack S' is conveyed towards the sheet processing section 71 by the discharge and reversing roller 24 at a speed V2.

[0088] In this way, the operation of superimposing two sheets S1 and S2 onto each other while aligning them, and then expelling them from the superposition processing section 4B (superposition-expulsion operation) is completed. In the case of continuously performing imaging operations on multiple sheets, by repeating the above superposition-expulsion operation, stacks of sheets, each consisting of two sheets, are successively stacked on the upper discharge tray 25.

[0089] Next, the advantages of this embodiment will be described by comparing it with the case where sheets S1 and S2 are discharged one by one without performing a stacking discharge operation. If sheets S1 and S2 are discharged one by one, the sheets S1 and S2 that have passed through the discharge and reversing rollers 24 fall onto the top surface of the upper discharge tray 25 or onto the top surface of the sheets stacked on the upper discharge tray 25. However, the position and orientation of sheet S1 may change before sheet S1 falls onto the top surface of the upper discharge tray 25, and the position and orientation of sheet S2 may change before sheet S2 falls onto the top surface of sheet S1. This is because, when viewed from above, sheets S1 and S2 fall while moving in the front-back direction and the left-right direction due to air resistance.

[0090] Conversely, in this embodiment, since sheets S1 and S2 are discharged while aligned and stacked on top of each other in the sheet conveying direction, the position and orientation changes of sheets S1 and S2 are minimal. This is because the stack of sheets discharged through the stacking discharge operation has twice the weight of a single sheet, yet its projected area when viewed from above is the same as that of a single sheet, thus experiencing less air resistance compared to discharging individual sheets one by one. Therefore, even if the sheet discharge speed generated by the discharge and reversing rollers 24 is increased to improve the productivity of the imaging system 1S and the sheet processing equipment 4, a decrease in sheet stacking performance can be prevented. In other words, in this embodiment, the sheet stacking performance in the upper discharge tray 25 can be increased while maintaining productivity. Furthermore, in this embodiment, unlike methods that stack, align, and discharge sheets through intermediate stacking sections (such as the sheet processing section 71), sheets can be stacked and discharged in a simple and compact configuration.

[0091] It should be noted that in this embodiment, the upper discharge tray 25, which serves as the stacking section, protrudes outward toward the main body 4A of the equipment. Therefore, the sheets discharged by the discharge and reversing rollers 24 into the space above the upper discharge tray 25 fall onto the upper discharge tray 25 due to gravity and are not conveyed to any other conveying section besides the discharge and reversing rollers 24. Even in this configuration, which is more susceptible to air resistance, the sheet stacking performance in the upper discharge tray 25 can be improved by performing a stacking discharge operation.

[0092] Stacking and stacking of three or more sheets

[0093] The above description has described the conveying of two sheets. However, the sheet processing apparatus 4 of this embodiment can perform a stacking discharge operation in which three or more sheets are stacked on top of each other while being aligned and discharged into the upper discharge tray 25 in the stacking processing section 4B.

[0094] When performing a stacking and ejection operation on three sheets, first, by executing the above reference... Figures 5A to 5F The described process involves stacking two sheets S1 and S2 on top of each other, then conveying the stack of sheets S' again in the G1 direction by rotating the discharge and reversing rollers 24 in opposite directions. Then, while performing the process on the stack of sheets S'... Figures 5C to 5F When an operation is performed on sheet S1, an operation already performed on the third sheet S3 (the third sheet) is also performed. Figures 5C to 5F The operation performed on the sheet S2 in the middle.

[0095] In these operations, after the sheet stack S' is temporarily stopped while being held by the internal discharge roller 26 located on the internal discharge path 82, the sheet stack S' is conveyed along the G2 direction by the internal discharge roller 26 at a predetermined time T_wait elapsed since the trailing edge of the third sheet was detected by the inlet sensor 27. Thereafter, the previously opened discharge and reversing roller 24 closes, so that the three sheets S1, S2, and S3 are simultaneously held by the discharge and reversing roller 24. When the trailing edge of sheet S3 passes the check guide 23, sheets S1, S2, and S3 form a sheet stack, wherein the leading edges of sheets S1, S2, and S3 are aligned with each other, and the trailing edges of sheets S1, S2, and S3 are aligned with each other.

[0096] If the number of sheets to be stacked and discharged is three, the stack is discharged directly along the G2 direction via the discharge and reversal rollers 24 and stacked on the upper discharge tray 25. If the number of sheets to be stacked and discharged is four or more, the number of stacked sheets can be increased by repeating the following operation, in which the stack is again conveyed along the G1 direction via the discharge and reversal rollers 24 and undergoes... Figures 5C to 5F The operation shown.

[0097] Based on the number of sheets that can be stacked on top of each other through the stacking processing section 4B and information about the sheets being conveyed, the sheet quantity control section 712 manages the number of sheets stacked on top of each other through the stacking processing section 4B. That is, the sheet quantity control section 712 determines whether the sheets already sent to the stacking processing section 4B are directly conveyed (discharged) to the upper discharge tray 25 or the sheet processing section 71, or whether subsequent sheets are stacked on top of the sheets.

[0098] An example of the determination method will be described. If the number of sheets that can be stacked on top of each other by the stacking processing section 4B is N, the sheet quantity control section 712 forms a stack of sheets with a quantity of N-1 sheets and discharges the stack of sheets to the upper discharge tray 25. That is, when the control section of this embodiment performs the operation of discharging multiple sheets to the stacking section, the control section repeats the stacking discharge operation as a discharge operation, such that for each predetermined number of sheets of multiple sheets to be discharged in the operation, a predetermined number of sheets are stacked on top of each other and discharged. In addition, if the control section determines that the Nth sheet is the last sheet in the operation, the control section sets N to the number of sheets stacked by the stacking processing section 4B. Therefore, the Nth sheet is prevented from being discharged to the upper discharge tray 25 alone.

[0099] For example, suppose that in the configuration of this embodiment, the number of sheets that can be stacked on top of each other by the stacking processing section 4B is five. In this case, the sheet quantity control section 712 repeats the stacking and discharge operation performed on four sheets, and stacks the sheet stacks, each containing four sheets, one by one on the upper discharge tray 25. If the sheet quantity control section 712 determines that the fifth sheet is the last sheet, and if the stacking and discharge operation is performed on four sheets, the last sheet will be discharged separately, the sheet quantity control section 712 performs the stacking and discharge operation on the five sheets including the last sheet, and discharges the sheets to the upper discharge tray 25. If the sheet quantity control section 712 determines that even if the stacking and discharge operation is performed on four sheets, the last sheet will be stacked on top of another sheet, then when a sheet stack is formed, the sheet quantity control section 712 discharges the sheet stack including the last sheet to the upper discharge tray 25.

[0100] In other words, when the sheet quantity control unit 712 performs the operation of discharging a predetermined number of sheets onto the upper discharge tray 25, the sheet quantity control unit 712 changes the number of sheets in the sheet stack formed by the stacking discharge operation based on the predetermined number of sheets. In this case, each of the predetermined number of sheets is included in the sheet stack, which comprises two or more sheets and is formed by the stacking discharge operation, and the sheet stack is discharged onto the upper discharge tray 25. In other words, the control unit in this embodiment changes the number of sheets to be stacked on top of each other by the stacking discharge operation based on the number of sheets discharged in the operation. In this case, each of the multiple sheets to be discharged during the operation is discharged to the stacking section, and the sheet is stacked on top of another sheet in the multiple sheets. Through this operation, since the sheets are not discharged individually to the upper discharge tray 25, the sheet stacking performance is prevented from deteriorating. It should be noted that the method of controlling the number of sheets stacked on top of each other by the stacking discharge operation is not limited to this, as long as it can prevent the sheets from being discharged individually. For example, the number of sheets superimposed on each other by the stacking and discharge operation can be changed, such that the number changes in order of 4, ..., 4, 3 and 2.

[0101] Determine T_wait

[0102] Next, the timing control performed by the superposition transfer control section 711 for aligning the leading edges of sheets S1 and S2 in the superposition processing section 4B (i.e., determining the aforementioned T_wait) will be described.

[0103] Figure 7AThe positional relationship between sheets S1 and S2 is shown when the trailing edge of sheet S2 is detected by inlet sensor 27. Distance L1 is the distance from the detection position of inlet sensor 27 to the clamping position of discharge and reversal roller 24 (distance L1 measured along receiving path 81 and first discharge path 83). Distance L2 is the distance from the position where the leading edge of sheet S1, whose conveying direction has been reversed, stops to the clamping portion of discharge and reversal roller 24 (distance L2 measured along first discharge path 83 and inner discharge path 82). The leading edge of sheet S1 stops at the position after the leading edge has passed the inner discharge roller 26 and moved a predetermined distance d1.

[0104] Figure 7B It shows in Figure 7A The positional relationship between sheet S1 and sheet S2 is obtained at the moment when the conveying speeds of sheet S1 and sheet S2 become equal after sheet S1 is started being conveyed along the F2 direction (G2 direction) in the state shown. Assume that at this moment, the trailing edge of sheet S1 in the F2 direction protrudes by an offset of Kt from the trailing edge of sheet S2 in the F2 direction.

[0105] Figure 7C It shows in Figure 7A and Figure 7B The velocity changes of sheets S1 and S2 obtained in the operation shown. Figure 7C In the text, time TA indicates that the trailing edge of sheet S2 is detected by the inlet sensor 27 (e.g., ...). Figure 7A (As shown) and the moment when the branch front roller 22 begins to uniformly accelerate from speed V1 to speed V2. Time TB represents the time when the sheet S2 completes its acceleration to speed V2. Time TC represents the moment when a predetermined time T_wait has elapsed since the inlet sensor 27 detected the trailing edge of the sheet S2, that is, the moment when the inner discharge roller 26 begins to convey the sheet S1 along the G2 direction. Time TD represents the moment when the relative speed of the sheet S1 relative to the sheet S2 (or the relative speed of the sheet S2 relative to the sheet S1) becomes zero.

[0106] In the following text, T_merge represents the time elapsed from TA to TD. Time T1 is the time required to increase the speed of the branch front roller 22 from speed V1 to speed V2 (i.e., the time elapsed from TA to TB). Time T2 is the time from when the acceleration of the branch front roller 22 to speed V2 is completed until the rotation of the inner discharge roller 26 begins (i.e., the time elapsed from TB to TC). Since T1, T2, and T_wait are defined as described above, time T_wait is expressed as: T_wait = T1 + T2. Time T3 is the time from when the uniform acceleration of sheet S1 begins in the stopped state until the speed of sheet S1 reaches speed V2 (i.e., the time elapsed from TC to TD).

[0107] As can be seen from the above description, sheet S1 from Figure 7A Move to the position shown Figure 7B The distance X2 that the position shown moves is equal to the distance from the sheet S1. Figure 7C The distance that TC moves to TD is given by equation (1). Therefore, the distance X2 is represented by the following equation (1).

[0108] X2 = (V2 × T3) / 2 (1)

[0109] In addition, sheet S2 from Figure 7A Move to the position shown Figure 7B The distance X1 that the position shown moves is equal to the distance from which sheet S2 moves. Figure 7C The distance that TA moves to TD is given by equation (2). Therefore, the distance X1 is represented by the following equation (2).

[0110] X1 = (V1 + V2) × T1 / 2 + V2 × (T2 + T3) (2)

[0111] According to Figure 7B The positional relationship between sheet S1 and sheet S2 at the time shown satisfies the following equation (3).

[0112] L1 - X1 = L2 - X2 – Kt (3)

[0113] If we substitute equations (1) and (2) into equation (3) and simplify equation (3), we get the following equation (4).

[0114] L1 - L2 + Kt = (T1 / 2) × V1 + (T1 / 2 + T2 + T3 / 2) × V2 (4)

[0115] If we substitute the equation T_wait = T1 + T2 into equation (4) and simplify equation (4), we get the following equation (5). Equation (5) represents the waiting time T_wait obtained when the protrusion Kt is provided, and the waiting time T_wait is the time from when the trailing edge of sheet S2 passes the inlet sensor 27 until the sheet S1 is conveyed from the internal discharge roller 26.

[0116] T_wait = (L1 - L2 + Kt) / V2 - (T1 / 2) × (V1 / V2) + (T1 - T3) / 2(5)

[0117] To stack sheets S1 and S2 such that the leading edges of sheet S1 and sheet S2 are aligned, and the trailing edges of sheet S1 and sheet S2 are aligned, a waiting time T_wait is calculated using equation (5) with Kt = 0. If sheet S1 is conveyed via the internal discharge roller 26 at a time based on the calculated waiting time T_wait, the sheet stack S' can be formed such that the leading edges of sheet S1 and sheet S2 are aligned, and the trailing edges of sheet S1 and sheet S2 are aligned. That is, a predetermined time (T_wait) is preset such that the edge portions of sheet S1 and sheet S2 in the conveying direction are aligned at the discharge and reversing roller 24, the predetermined time being from when sheet S2 is detected by the inlet sensor 27 until when the conveying of sheet S1 begins via the internal discharge roller 26. Furthermore, the same value T_wait can be used to form a stack of sheets when three or more sheets are stacked on top of each other, where the leading edges of one sheet are aligned with the leading edges of another sheet, and the trailing edges of one sheet are aligned with the trailing edges of another sheet.

[0118] Example of control

[0119] Next, we will refer to Figure 6 The flowchart below illustrates an example of a method for controlling sheet processing equipment 4, and its implementation is referenced. Figures 5A to 5F The described stacking and ejection operation. Whenever the main control unit 603 of the sheet processing equipment 4 receives a notification from the video controller 601 to eject a single sheet from the imaging equipment 1, the process described in the flowchart is executed. It should be noted that, unless otherwise specified, the process is executed by... Figure 4 The superimposed transmission control section 711 shown executes each process of the flowchart.

[0120] In the following description, the first sheet is the sheet that is first conveyed to the sheet processing device 4 to form a stack of sheets to be stacked in the stacking processing section 4B. For example, in the case where four sheets are stacked on top of each other and discharged to the upper discharge tray 25, the first sheet is the sheet that is conveyed to the sheet processing device 4 after the last sheet of the previous sheet stack, i.e., the (4n+1)th sheet. Furthermore, the last sheet is the sheet that is last conveyed to the sheet processing device 4 to form a stack of sheets to be formed in the stacking processing section 4B (in the example above, the last sheet is the 4nth sheet).

[0121] In step S101, the superimposed conveying control section 711 initiates the rotation of the inlet roller 21 and the branching pre-roller 22 at a speed V1. Then, the superimposed conveying control section 711 proceeds to step S102. It should be noted that if the inlet roller 21 and the branching pre-roller 22 have already rotated at speed V1 in step S101, the superimposed conveying control section 711 maintains the rotation of the inlet roller 21 and the branching pre-roller 22. In step S102, the superimposed conveying control section 711 determines whether the current sheet is the first sheet. If it is, the superimposed conveying control section 711 proceeds to step S103. If it is not, the superimposed conveying control section 711 proceeds to step S106.

[0122] In step S103, the superimposed conveying control section 711 brings the discharge and reversing rollers 24 abut against each other and begins rotating them at a speed V1 in the direction (G2 direction) toward conveying the first sheet towards the upper discharge tray 25. Then, the superimposed conveying control section 711 proceeds to step S104. In step S104, the superimposed conveying control section 711 determines whether the trailing edge of the first sheet has passed the inlet sensor 27. If yes, the superimposed conveying control section 711 proceeds to step S105. If no, the superimposed conveying control section 711 proceeds to step S104. In step S105, the superimposed conveying control section 711 accelerates the branch front roller 22 and the discharge and reversing rollers 24 to a speed V2 (see...). Figure 5A The sheet shown is S1). Then, the stacking and conveying control section 711 proceeds to step S111.

[0123] In step S106, the superimposed conveying control section 711 determines whether the trailing edge of the current sheet (i.e., the second sheet or another sheet following the second sheet) has passed the inlet sensor 27. If it is determined to be yes, the superimposed conveying control section 711 proceeds to step S107. If it is determined to be no, the superimposed conveying control section 711 proceeds to step S106. In step S107, the superimposed conveying control section 711 accelerates the branch front roller 22 and the discharge and reverse roller 24 to speed V2. Through this operation, the conveying speed of the current sheet increases from speed V1 to speed V2 (see...). Figure 5D (Showing sheet S2). Then, the overlay transfer control unit 711 proceeds to step S108. In step S108, the overlay transfer control unit 711 determines whether a predetermined time T_wait has elapsed since the trailing edge of the current sheet passed through the entry sensor 27. If it is determined to be yes, the overlay transfer control unit 711 proceeds to step S109. If it is determined to be no, the overlay transfer control unit 711 proceeds to step S108.

[0124] In step S109, the superimposed conveying control section 711 causes the inner discharge roller 26 to start rotating again at a speed V2 in the direction (F2 direction) in which the first sheet is conveyed toward the discharge and reversing roller 24 (see...). Figure 5D The sheet S1 shown is then moved to step S110. In step S110, at the moment when the conveying speed of the sheet (stack) being conveyed by the internal discharge roller 26 becomes equal to the conveying speed of the current sheet, the stacking conveying control unit 711 moves the upper roller 24a of the discharge and reverse roller 24 in the E2 direction, causing the upper roller 24a to abut against the lower roller 24b (see [reference]). Figure 5E Through this operation, the sheet (stack) being conveyed by the internal discharge roller 26 and the current sheet are simultaneously held by the discharge and reversing rollers 24 (see...). Figure 5E Then, the superimposed transfer control section 711 proceeds to step S111.

[0125] In step S111, the overlay transfer control unit 711 determines whether the current sheet is the last sheet. If it is determined to be yes, the overlay transfer control unit 711 proceeds to step S112. If it is determined to be no, the overlay transfer control unit 711 proceeds to step S115.

[0126] In step S112, the superimposed conveying control section 711 causes the stack of sheets, including the last sheet, to be discharged onto the upper discharge tray 25 (see...). Figure 5F In other words, the stacking conveying control section 711 maintains the sheet conveying performed by the discharge and reversing rollers 24 and the inner discharge roller 26, which begins in S107 and S109, such that the sheet stack is discharged to the upper discharge tray 25. The sheet stack includes the current sheet and has a predetermined number of sheets. Furthermore, in the sheet stack, the leading edge of one sheet is aligned with the leading edge of another sheet, and the trailing edge of one sheet is aligned with the trailing edge of another sheet.

[0127] In step S113, the overlay conveying control unit 711 determines whether the trailing edge of the sheet stack has passed the discharge and reversal roller 24. If yes, the overlay conveying control unit 711 proceeds to step S114. If no, the overlay conveying control unit 711 proceeds to step S113. In step S114, the overlay conveying control unit 711 decelerates the branch front roller 22 to speed V1, stops the discharge and reversal roller 24 and the inner discharge roller 26, and ends the process. It should be noted that if the current sheet is the last sheet in operation (that is, if no more sheets are to be sent from the imaging device 1), the overlay conveying control unit 711 also stops the inlet roller 21 and the branch front roller 22 in step S114.

[0128] In step S115, the superimposed conveying control section 711 determines whether the trailing edge of the current sheet (i.e., the sheets excluding the last sheet) has passed the check guide 23. If yes, the superimposed conveying control section 711 proceeds to step S116. If no, the superimposed conveying control section 711 proceeds to step S115. In step S116, the superimposed conveying control section 711 temporarily stops the discharge and reverse roller 24 and the internal discharge roller 26 (see...). Figure 5B The sheet (S1) shown. Then, the stacking conveying control section 711 proceeds to step S117. In step S117, the stacking conveying control section 711 causes the discharge and reversing rollers 24 and the inner discharge rollers 26 to start rotating in the rotational direction at a speed V2, so that the sheet (stack) is conveyed in the reverse direction (F1 direction, G1 direction). Then, the stacking conveying control section 711 proceeds to step S118.

[0129] In step S118, the superimposed conveying control unit 711 determines whether the leading edge of the sheet (stack) has passed the inner discharge roller 26. If it is determined to be yes, the superimposed conveying control unit 711 proceeds to step S119. If it is determined to be no, the superimposed conveying control unit 711 proceeds to step S118. In step S119, the superimposed conveying control unit 711 separates the upper roller 24a and lower roller 24b of the discharge and reversing roller 24. Then, the superimposed conveying control unit 711 proceeds to step S120. In step S120, at a position where the leading edge of the sheet (stack) has been conveyed a predetermined distance after passing the inner discharge roller 26, the superimposed conveying control unit 711 decelerates the branch front roller 22 to speed V1, stops the discharge and reversing roller 24 and the inner discharge roller 26, and ends the process.

[0130] Through these operations, the sheet (stack) on which the stacking discharge operation has already been performed and on which another sheet is to be stacked (see) is held and maintained by the internal discharge roller 26. Figure 5D The sheet S1 shown. It should be noted that the timing of steps S109, S113, S115, and S118 can be determined from system timer 612 (…). Figure 6 The timing is determined by the timing signal sent. For example, the timing is determined based on the operating history of the discharge and reversal rollers 24 and the internal discharge rollers 26, which is obtained over a period of time from when the inlet sensor 27 detects the trailing edge of the sheet S1.

[0131] As described above, in this embodiment, when multiple sheets are continuously conveyed and discharged into the stacking section, the sheets are stacked on top of each other in the stacking processing section 4B with the edges of one sheet aligned with the edges of another sheet, and then discharged into the stacking section. Therefore, while maintaining productivity, the sheet stacking performance in the stacking section can be improved. Furthermore, discharging the stacked sheets into the upper discharge tray 25 eliminates the need for an intermediate tray in the sheet handling equipment that includes a sheet alignment function. Therefore, the need for larger equipment and the resulting cost increases can be prevented.

[0132] It should be noted that although the maximum number of sheets (i.e., the number of sheets that can be superimposed on each other by the superposition processing section 4B) is five in the example configuration of this embodiment, the number of sheets that can be superimposed on each other by the superposition processing section 4B can be appropriately changed depending on the specific configuration of the superposition processing section 4B and the desired performance.

[0133] Buffering operations performed during sheet processing.

[0134] When the sheet processing section 71 processes the sheet, the overlay processing section 4B in this embodiment also functions as a buffer. That is, if the overlay processing section 4B receives a sheet from the imaging device 1 while the sheet processing section 71 is processing the sheet, the overlay processing section 4B overlays the sheet onto another sheet and holds these sheets in place. By performing this buffering operation, sheet collisions in the sheet processing section 71 are prevented without reducing the productivity of the imaging device 1. Therefore, the productivity of the imaging system 1S is increased.

[0135] In the buffering operation, the operation of the stacking processing section 4B is basically the same as the stacking discharge operation, except that the stacking processing section 4B conveys the stacked sheets to the sheet processing section 71 through the internal discharge path 82. That is to say, through Figures 5A to 5F The operation shown is as follows: Figure 5F The stacked sheets shown are not conveyed to the upper discharge tray 25, but are instead conveyed to the sheet processing section 71 via the internal discharge roller 26. After the sheet stack is conveyed to the sheet processing section 71 during the buffering operation, subsequent sheets that do not require a buffering operation are folded back one by one via the discharge and reversing rollers 24 and conveyed to the sheet processing section 71.

[0136] It should be noted that in buffering operations, the bulge amount Kt ( Figure 7B The sheet can be configured such that the leading edge of one stacked sheet is offset from the leading edge of another stacked sheet. In this case, the protrusion Kt is preferably set such that the lower sheet stacked lower in the sheet processing section 71 (i.e., Figure 7BThe sheet S1 shown protrudes in the sheet conveying direction extending toward the sheet processing section 71. If the protrusion amount Kt is set as described above, the alignment operation can be effectively performed by bringing the semi-circular roller 33 into contact with each sheet of the sheet stack formed by the buffering operation. In particular, it is preferable that the protrusion amount Kt is greater than the distance between the contact position between the semi-circular roller 33 and the sheet and the vertical alignment reference plate 39.

[0137] As described above, the stacking processing section 4B of this embodiment has the function of performing a stacking discharge operation when the sheet is discharged outside the sheet processing equipment 4 without being processed in the sheet processing section 71, and the function of buffering the sheet to be processed in the sheet processing section 71. Therefore, compared with the configuration that provides two mechanisms to stack the sheet in order to achieve the above functions, the configuration of this embodiment can reduce the size of the equipment and reduce the cost of the equipment.

[0138] Second Embodiment

[0139] In the first embodiment described above, a method for improving stacking performance by performing a stacking and ejection operation of stacked sheets has been described. In the second embodiment, in the stacking and ejection operation described in the first embodiment, the waiting position of a sheet on which another sheet is to be stacked changes according to the length of the sheet in the transport direction. Hereinafter, components given the same symbols as those in the first embodiment are considered to have the same structure and effects as those components in the first embodiment, and therefore their description will be omitted.

[0140] In the stacking operation described in the first embodiment, by Figures 5A to 5D The operation shown involves reversing the conveying direction of the previous sheet S1 and stopping the sheet S1 at a certain position. Figure 5D The location at which sheet S1 stops will be described below. In this description, the length of sheet S1 in the conveying direction is represented by Ls. Furthermore, the length from the clamping position of the discharge and reversing roller 24 to the edge portion S1a of sheet S1 on the G1 direction side (i.e., on the side of the inner discharge roller 26) is represented by L2. Additionally, the length from the clamping position of the discharge and reversing roller 24 to the edge portion S1b of sheet S1 protruding outwards toward the sheet processing equipment 4 is represented by L3. Therefore, lengths Ls, L2, and L3 satisfy the following relationship: Ls = L2 + L3.

[0141] like Figure 8A and Figure 8BAs shown, the length Ls of the longer sheet in the conveying direction (e.g., an A4 sheet whose long side is parallel to the conveying direction) is represented by Ls1, and the length Ls of the shorter sheet in the conveying direction (e.g., an A5 sheet whose long side is parallel to the conveying direction) is represented by Ls2. Length Ls1 is an example of a first length, and length Ls2 is an example of a second length.

[0142] In this embodiment, regardless of whether the length Ls of the sheet S1 is Ls1 or Ls2, the length L3 of the edge portion S1b of the sheet S1 protruding from the discharge and reversing roller 24 is equal to or less than a predetermined value Lmax. It should be noted that the predetermined value Lmax is determined in advance to prevent the edge portion S1b of the sheet S1 (or stack of sheets) protruding from the clamping position of the discharge and reversing roller 24 by the predetermined value Lmax from resting against the upper discharge tray 25. Figure 8C As shown. This is because if the edge portion S1b of the temporarily stopped sheet S1 rests against the sheet St stacked on the upper discharge tray 25, the sheet S1 will rub against the sheet St when it is discharged later, which may change the position of the stacked sheet St.

[0143] It should be noted that the discharge and reversing rollers 24 are designed such that, when the discharge and reversing rollers 24 clamp the sheet, the cross-sectional shape of the sheet is slightly curved (or undulating) in the sheet width direction when viewed from the downstream side in the sheet discharge direction. For example, the discharge and reversing rollers 24 can be so-called comb rollers. In this case, the sheet-contacting portions of the upper roller 24a (roller body on the roller shaft) and the sheet-contacting portions of the lower roller 24b (roller body on the roller shaft) are arranged alternately in the sheet width direction. Furthermore, the outer peripheral surfaces of the roller bodies of the upper roller 24a and the lower roller 24b are arranged to overlap each other when viewed in the sheet width direction.

[0144] As described above, the discharge and reversing rollers 24 convey the sheet while simultaneously giving it a curved shape. As a result, as Figure 8D As shown, sheets are discharged by stacking stacks S' of sheets together in a stacking discharge operation, wherein the stacks S' maintain their straight orientation and wherein the edge portions S1b do not bend downwards. Therefore, the possibility of the stacks S' of sheets rubbing against the sheets St stacked on the upper discharge tray 25 and deteriorating the stacking performance of the sheets St can be reduced.

[0145] Figure 9 A functional block diagram of the imaging system 1S of this embodiment is shown. The functional block diagram of this embodiment is similar to... Figure 4 The functional block diagram of the first embodiment shown differs in that, in addition to the sheet quantity control section 712, the stacking and conveying control section 711 also includes a stop position control section 713. When multiple sheets are stacked on top of each other in the stacking processing section 4B, the stop position control section 713 controls the position (stop position) where the previous sheet is temporarily stopped.

[0146] The stop position control section 713 determines the length L2 according to the following equation (6). The length Ls of the sheet in the conveying direction is obtained from the video controller 601 via the communication section 611.

[0147] L2 = Ls - Lmax (6)

[0148] The method for controlling sheet processing equipment 4 is basically the same as the reference. Figure 6 The method described in the first embodiment is the same. In the first embodiment described above, in step S120, after the leading edge of the sheet S1 passes through the inner discharge roller 26, when the leading edge of the sheet S1 has been conveyed a predetermined distance (i.e., Figure 7B When the sheet S1 is at a predetermined distance d1, the discharge and reversal roller 24 and the inner discharge roller 26 are stopped. However, in this embodiment, the discharge and reversal roller 24 and the inner discharge roller 26 are stopped at a point in time when the sheet S1 has been conveyed a distance d2 after the leading edge of the sheet S1 has passed the inner discharge roller 26. The distance d2 corresponds to the length L2, which is determined by equation (6) and calculated by equation d2 = L2 - d4, where d4 is the distance from the clamping position of the discharge and reversal roller 24 to the inner discharge roller 26. Therefore, the distance d2 is a variable that varies according to the sheet length Ls. It should be noted that the distance can be determined according to the system timer 612 ( Figure 6 The timing signal sent determines the timing of the distance d2 that the leading edge of sheet S1 has been conveyed after passing through the internal discharge roller 26. For example, the timing is determined based on the operation history of the discharge and reversal rollers 24 and the internal discharge roller 26, which is obtained over a period of time from when the inlet sensor 27 detects the trailing edge of sheet S1. Another timing control performed by the superimposed conveying control section 711 (e.g., determining the aforementioned waiting time T_wait) is the same as the timing control in the first embodiment.

[0149] By using the above method, the waiting position of the sheet S1 when it is temporarily stopped changes according to the length Ls of the sheet. As a result, the protruding length L3 of the sheet S1 at the point when the sheet S1 is temporarily stopped can be set to be equal to or less than the predetermined value Lmax. In this method, during the process of stacking the sheets S1 and S2 on each other in the stacking processing section 4B, the edge portion S1b of the sheet S1 that is temporarily stopped to wait for the subsequent sheet S2 can be prevented from bending downward and rubbing against the sheet St that has already been stacked on the upper discharge tray 25. As a result, the possibility that the sheet S1 drags the stacked sheet St and changes the position of the sheet St when the sheets S1 and S2 are discharged can be reduced. Therefore, the stacking performance of the discharged sheets can be improved for sheets of various sizes. In addition, even if the sheet S1 is curled (that is, the sheet S1 has a curved shape), the temporarily stopped sheet S1 will hardly curl noticeably outside the discharge and reversing roller 24. Therefore, the possibility of the edge portion S1b becoming rounded when the sheets S1 and S2 are discharged can be reduced.

[0150] It should be noted that there are cases where the range of length L2 is limited depending on the configuration of the equipment. For example, the lower limit of length L2 may be set such that the conveying of sheet S1 temporarily stops after the edge portion S1a of sheet S1 is clamped by the inner discharge roller 26. In this case, the lower limit of length L2 may be a value obtained by adding the distance from the clamping position of the discharge and reversing roller 24 to the clamping position of the inner discharge roller 26 to a margin determined to make the inner discharge roller 26 clamp the edge portion S1a more reliably.

[0151] Furthermore, if the edge portion S1a of sheet S1 reaches the intermediate conveyor roller 28 after passing through the internal discharge roller 26 ( Figure 1 After temporarily stopping the conveying of sheet S1, not only the inner discharge roller 26 but also the intermediate conveyor roller 28 must be driven synchronously with the inner discharge roller 26 in the opposite conveying direction to stack sheets S1 and S2 on top of each other. Therefore, an upper limit for length L2 is set to achieve a simple configuration where the intermediate conveyor roller 28 is driven only in one direction. In this case, the upper limit for length L2 can be a value obtained by subtracting a margin from the distance from the clamping position of the discharge and reversing roller 24 to the clamping position of the intermediate conveyor roller 28. This margin is determined to more reliably prevent the edge portion S1a from contacting the intermediate conveyor roller 28.

[0152] As described above, in this embodiment, the waiting position is changed according to the length of the sheet in the conveying direction. In this case, the waiting position can be changed only when the sheet is about to be discharged onto the upper discharge tray 25. This is because if the sheet is to be discharged onto the lower discharge tray 37, the sheet stack S' will eventually be discharged in the direction extending from the stacking processing section 4B toward the sheet processing section 71. In this case, the sheet stack S' hardly interferes with the sheet stacked on the upper discharge tray 25. Therefore, if the sheet is to be discharged onto the lower discharge tray 37, the distance the sheet is conveyed before stopping and in the reverse direction of the conveying direction and after the leading edge of the sheet passes through the inner discharge roller 26 can be set independently of the length of the sheet in the conveying direction.

[0153] Variant

[0154] In the first and second embodiments described above, the internal discharge path 82, which serves as the second conveying path, is connected to the sheet processing section 71. However, the second conveying path may be connected to the destination to which the sheet is discharged, rather than the sheet processing section 71. For example, the sheet processing section 71 may not be provided, and the sheet conveyed via the internal discharge path 82 may be discharged to the lower discharge tray 37 without being processed. Furthermore, the second conveying path may have a closed-end configuration, wherein the second conveying path is not connected to the outside of the sheet processing device 4.

[0155] Furthermore, in the first and second embodiments described above, the sheet discharge device of the sheet processing device 4, which is separately provided from the imaging device 1, has been described. However, the technology of this disclosure can also be applied to a sheet discharge device that discharges a sheet from the imaging device 1 or from another device that processes the sheet.

[0156] Other embodiments

[0157] Embodiments of the present invention can also be implemented by a computer of a system or device that reads and executes computer-executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more fully referred to as a "non-transitory computer-readable storage medium") to perform one or more functions of the above embodiments and / or includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing one or more functions of the above embodiments, and by a method performed by the computer of the system or device, for example, by reading and executing computer-executable instructions from a storage medium to perform one or more functions of the above embodiments and / or controlling one or more circuits to perform one or more functions of the above embodiments. The computer may include one or more processors (e.g., a central processing unit (CPU), a microprocessor unit (MPU)) and may include a network of individual computers or individual processors to read and execute computer-executable instructions. The computer-executable instructions may be provided to the computer, for example, from a network or a storage medium. The storage medium may include one or more of, for example, a hard disk, random access memory (RAM), read-only memory (ROM), the memory of a distributed computing system, an optical disk (such as an optical disk (CD), a digital versatile optical disk (DVD), or a Blu-ray disc (BD)™), a flash memory device, and a memory card.

[0158] Other embodiments The embodiments of the present invention can also be implemented by providing software (programs) that perform the functions of the above embodiments to a system or device via a network or various storage media, and the computer or central processing unit (CPU) or microprocessor unit (MPU) of the system or device reads out and executes the program.

[0159] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims should be given the broadest interpretation in order to cover all such variations and equivalent structures and functions.

Claims

1. A sheet discharge device, comprising: Equipment body; The stacked portion, on which sheets are stacked; First transmission section; The second conveying section includes an upper roller and a lower roller forming a clamping portion, wherein the upper roller is movable between a contact position in which the upper roller contacts the lower roller and a separation position in which the upper roller separates from the lower roller; The third transmission section; as well as The control section is configured to perform the discharge operation by causing the sheet discharge device to perform the following operations: The first sheet is transferred to the second transfer section using the first transfer section; The first sheet is received at the second conveying section when the upper roller is in the contact position; The first sheet is conveyed toward the third conveying section by using the second conveying section; After the first sheet is conveyed to the third conveying section and held by the third conveying section, and before the second sheet, which is conveyed after the first sheet, arrives at the second conveying section, the upper roller is moved to the separation position. While the upper roller is in the separated position, the second sheet is conveyed to the second conveying section by using the first conveying section, such that the first sheet and the second sheet are superimposed on each other at the second conveying section; The upper roller moves from the separation position to the contact position to clamp the first sheet and the second sheet; and While the first sheet and the second sheet are held and stacked on top of each other by the second conveying section, the first sheet and the second sheet are discharged by using the second conveying section so that the first sheet and the second sheet are stacked on the stacking section.

2. The sheet discharge device according to claim 1 further includes a detection section, the detection section being configured to respond to a sheet output detection signal. in, In the discharge operation, the control section is configured such that the third conveying section conveys the first sheet to the second conveying section at a time elapsed since the detection section responded to the second sheet outputting a detection signal.

3. The sheet discharge device according to claim 2, The predetermined time is preset such that the first sheet and the second sheet overlap each other at the second conveying section.

4. The sheet discharge device according to claim 1, in, The first sheet and the second sheet are discharged from the second conveying section into the space above the stacking section and fall onto the stacking section due to gravity, and are not conveyed by any other conveying section after passing through the second conveying section.

5. The sheet discharge device according to claim 1, wherein, In the discharge operation, the control section is configured to form a stack of sheets consisting of three or more sheets, including a first sheet and a second sheet, and is configured such that the second conveying section discharges the stack of sheets to the stacking section.

6. The sheet discharge device according to claim 5, wherein, When the control unit performs the operation of discharging multiple sheets into a stacking section, the control unit is configured to repeat the discharge operation such that for each predetermined number of sheets in the multiple sheets, the predetermined number of sheets are stacked on top of each other and discharged into the stacking section.

7. The sheet discharge apparatus of claim 6, wherein the control portion is configured to change the number of sheets stacked on top of each other in the discharge operation based on the number of the plurality of sheets discharged by the operation, such that each of the plurality of sheets is discharged into a stacking portion while the sheet is stacked on top of another sheet of the plurality of sheets.

8. The sheet discharge device according to claim 1, in, When the first sheet stops after being conveyed to the third conveying section, a portion of the first sheet protrudes from the second conveying section toward the exterior of the device body on the side where the stacking portion is located, and The control unit is configured to change the stopping position of the first sheet according to the length of the first sheet in the conveying direction of the first sheet.

9. The sheet discharge device according to claim 8, The control unit is configured to change the stop position such that the distance from the third conveying section to the stop position of the first sheet having a first length is greater than the distance from the third conveying section to the stop position of the first sheet having a second length less than the first length.

10. The sheet discharge device according to claim 8, The stacked portion is used as a first stacked portion. The sheet discharge device further includes a second stacking section, and The control portion is configured to change the stop position of the first sheet when the first sheet and the second sheet are to be discharged into the first stack portion, and not to change the stop position of the first sheet when the first sheet and the second sheet are to be discharged into the second stack portion.

11. A sheet processing apparatus, comprising: Sheet discharge device according to any one of claims 1 to 10; as well as The sheet processing section is configured to process sheets in pairs.

12. The sheet processing apparatus of claim 11, wherein the control unit is configured to perform a buffering operation instead of a discharge operation by causing the sheet discharge device to perform the following operations: (i) stacking multiple sheets of sheet material transferred from outside the sheet processing apparatus onto each other using a first conveying unit, a second conveying unit, and a third conveying unit; and (ii) transferring the multiple sheets of sheet material to the sheet processing unit after the processing performed by the sheet processing unit is completed. The control section is configured to control the buffering operation such that the edge portions of multiple sheets stacked on top of each other in the buffering operation are offset from each other in their transport direction, and The sheet processing section includes: The middle stacked section; A reference member is positioned downstream of the intermediate stack in the sheet discharge direction; A movable component configured to move the sheet discharged into the intermediate stack toward the reference component and align the sheet with the reference component; as well as A pushing member configured to push the sheet that has already been processed by the sheet processing section in a direction opposite to the sheet discharge direction.

13. An imaging system comprising: An imaging device configured to form an image on a sheet; as well as The sheet processing equipment according to claim 11 or 12.

Images