Sheet post-processing apparatus and image forming system including the same

Abstract

The invention provides a sheet post-processing apparatus and an image forming system including the same. The sheet post-processing apparatus includes a first conveying member, a processing tray, a first processing unit, a reference plate, an alignment member, an original position detection unit, a drive unit, and a control unit. The alignment member is provided with: a shaft that is connected to the drive unit and rotates; and one or more alignment paddle plates which protrude in the radial direction of the shaft and are in contact with the sheet fed onto the processing tray. The control unit calculates an expected contact section having the possibility that the rear end of the sheet comes into contact with the alignment paddle plate, and an interference time at which the alignment paddle plate interferes with the input path of the sheet. When the interference time is within the expected contact section, the control unit temporarily changes the rotation speed of the alignment member from the reference speed so that the phase of the alignment paddle plate is changed so that the interference time is outside the expected contact section.

Description

Technical Field

[0001] The present invention relates to a sheet post-processing device that performs a predetermined post-processing on a sheet after an image is formed by an image forming device, and an image forming system including the same. Background Art

[0002] A sheet post-processing device is known, which stacks multiple sheets after an image is formed by an image forming device such as a copier or a printer, and performs: a binding process of arranging the stacked sheet bundles and binding them by stapling; a perforation forming process of opening perforations by a perforation forming device; and a folding process of forming folds on the sheets.

[0003] Such a sheet post-processing device is provided with a processing tray on which a predetermined number of sheets with images formed thereon are loaded. In addition, the sheets loaded on the processing tray are subjected to binding processing, shift discharge processing (sorting processing), etc. In addition, in order to smoothly perform binding processing and shift discharge processing, etc., alignment components such as alignment paddles are also used to align the sheets on the processing tray. Summary of the invention 1. Technical issues to be resolved

[0004] An object of the present invention is to provide a sheet post-processing apparatus and an image forming system including the same, which can prevent the rear end of a sheet fed onto a processing tray from contacting an alignment member, thereby improving the alignment of the sheets. (II) Technical solution

[0005] The sheet post-processing device of the first structure of the present invention is characterized in that it comprises: a first conveying component that conveys sheets; a processing tray that carries a plurality of the sheets input along a specified input direction by the first conveying component; a first processing unit that performs specified post-processing on the sheets loaded on the processing tray; a reference plate that abuts against an end edge on the downstream side of an alignment direction in the opposite direction of the input direction of the sheets input onto the processing tray, so that the sheets are aligned in the input direction; an alignment component that has an axis and one or more alignment paddles, the axis being arranged above the processing tray and rotating, the alignment paddles protruding in the radial direction of the axis and contacting the sheets input onto the processing tray, the alignment component rotates in the alignment direction on a surface opposite to the processing tray, thereby aligning the sheets in the alignment direction. The sheet input on the processing tray moves in the alignment direction to assist the alignment of the sheet; an original position detection unit, which detects that the alignment paddle is in a reference position; a driving unit, which drives the alignment component; and a control unit, which controls the driving unit, the control unit calculates an expected contact interval based on the output information of the sheet, the expected contact interval has the possibility that the rear end of the sheet input along the input direction will contact the alignment paddle, and the control unit calculates the interference moment of the alignment paddle and the input path of the sheet based on the detection result of the original position detection unit, and when the interference moment is within the expected contact interval, the control unit temporarily changes the rotation speed of the alignment component from the reference speed to change the phase of the alignment paddle in a manner that the interference moment is outside the expected contact interval. Furthermore, the present invention is an image forming system comprising: an image forming apparatus that forms an image on a sheet; and a sheet post-processing apparatus of the above structure that performs a predetermined post-processing on the sheet on which the image is formed by the image forming apparatus. (III) Beneficial effects

[0006] According to the first structure of the present invention, when the expected contact interval calculated based on the output information of the sheet coincides with the interference moment of the alignment paddle, the phase of the alignment paddle is appropriately corrected. As a result, it is possible to suppress the alignment paddle from squeezing the sheet, and the sheet can be stably conveyed and aligned on the processing tray. In addition, since it is not necessary to stop the rotation of the alignment component, the influence on the neatness of the sheets loaded on the processing tray can be reduced. According to the second configuration of the present invention, there is obtained an image forming system including a sheet post-processing device capable of stably conveying sheets and aligning and loading the sheets on a processing tray. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 11 is a schematic diagram showing a configuration of an image forming system including a sheet post-processing apparatus 1 and an image forming apparatus 200 connected to the sheet post-processing apparatus 1 according to an embodiment of the present invention. Figure 2 It is a side cross-sectional view schematically showing the structure of the sheet post-processing apparatus 1 according to the present embodiment. Figure 3 It is a perspective view of the sheet stapling unit 92 provided in the sheet post-processing apparatus 1 according to the present embodiment. Figure 4 is a side view of the sheet binding unit 92 . Figure 5 It is a side cross-sectional view showing the structure of the first sheet conveying path 3 from the sheet input port 2 to the first sheet discharge portion 4 of the sheet post-processing apparatus 1 . Figure 6 It is a perspective view of the intermediate transport roller pair 54 and the alignment member 55 . Figure 7 yes Figure 6 An enlarged view of the vicinity of the home position detection unit 58 in FIG. Figure 8 1 is a side cross-sectional view showing the structure around the alignment member 55 , and shows a state where the alignment paddle 552 is in the original position. Fig. 9 1 is a side cross-sectional view showing the structure of the processing tray 521 and the surroundings of the alignment member 55 , and shows a state in which the alignment paddle 552 is in contact with the rear end of the sheet S. FIG. Fig.10 1 is a side cross-sectional view showing the structure of the processing tray 521 and the periphery of the alignment member 55 , and shows a state where the contact with the rear end of the sheet S is prevented by shifting the phase of the alignment paddle 552 . Fig.11 This is a flowchart showing an example of phase adjustment control of the alignment member 55 in the sheet post-processing apparatus 1 according to the present embodiment. DETAILED DESCRIPTION

[0008] (1. Configuration of image forming system) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 1 is a schematic diagram showing a configuration of an image forming system including a sheet post-processing apparatus 1 and an image forming apparatus 200 connected to the sheet post-processing apparatus 1 according to an embodiment of the present invention.

[0009] like Figure 1As shown, the image forming apparatus 200 prints an image on a sheet (paper) based on image data input from the outside via a network communication unit (not shown) or image data read by an image reading unit 201 disposed on the upper part of the image forming apparatus 200. In this embodiment, the image forming apparatus 200 is an inkjet recording apparatus that includes a recording head (not shown) for each color, and the recording head is provided with a plurality of nozzle holes for ejecting ink onto a sheet.

[0010] An operation panel 202 is arranged in front of the image reading unit 201. The operation panel 202 is an operation unit for receiving various setting inputs. For example, the user can operate the operation panel 202 to input the size information of the sheet. In addition, the operation panel 202 can also be operated to input the number of sheets to be printed or to instruct the start of a printing task. The main body control unit 203 comprehensively controls the operation of the image forming apparatus 200 as a whole and controls each unit of the image forming apparatus 200.

[0011] The sheet post-processing device 1 is detachably connected to the side of the image forming device 200. The sheet post-processing device 1 performs post-processing such as punching (punching) and stapling on the sheet after image formation (printing) by the image forming device 200. In addition, the sheet post-processing device 1 is not limited to post-processing the sheet automatically conveyed from the image forming device 200, and the user can also convey the sheet set on the tray (not shown) to the position where post-processing can be performed, and post-process the sheet.

[0012] (2. Structure of sheet post-processing device) Figure 2 1 is a side cross-sectional view schematically showing the structure of the sheet post-processing device 1 of this embodiment. Figure 2 As shown, the sheet post-processing device 1 includes: a sheet input port 2, a first sheet conveying path 3, a first sheet discharge section 4, a second sheet conveying path 5, a second sheet discharge section 6, a third sheet conveying path 7, a third sheet discharge section 8, a punching section 91, a sheet binding unit 92, a binding section 94, and a post-processing control section (control section) 10.

[0013] The sheet input port 2 is an opening provided on the side of the sheet post-processing apparatus 1 facing the image forming apparatus 200. The sheet conveyed from the image forming apparatus 200 toward the sheet post-processing apparatus 1 passes through the sheet input port 2 and is input into the sheet post-processing apparatus 1.

[0014] The first sheet conveying path 3 extends from the sheet input port 2 to the first sheet discharge portion 4 in a direction away from the image forming apparatus 200 ( Figure 2The sheet conveying path 3 is a first sheet conveying path 3 having a sheet conveying roller pair 31 and a middle sheet conveying roller pair 54, which convey the sheet input from the sheet input port 2 to the sheet post-processing device 1 toward the downstream side of the sheet conveying direction.

[0015] Two switching guides 32 are arranged on the first sheet conveying path 3. The upstream side of the first sheet conveying path 3 in the sheet conveying direction ( Figure 1 The switching guide 32 (on the right side) is arranged at the branch part of the second sheet conveying path 5 and rotates to the following position, namely: the sheet conveyed on the first sheet conveying path 3 from the sheet input port 2 side is guided along the first sheet conveying path 3 to the position of the first sheet discharge part 4; and the sheet conveyed on the first sheet conveying path 3 from the sheet input port 2 side is branched from the first sheet conveying path 3 and guided to the position of the second sheet conveying path 5.

[0016] The downstream side of the first sheet conveying path 3 in the sheet conveying direction ( Figure 1 The switching guide 32 (on the left side of the sheet conveying path 7) is arranged at the branching portion of the third sheet conveying path 7 and rotates to the following positions: a position where the sheet conveyed on the first sheet conveying path 3 from the sheet input port 2 side is guided along the first sheet conveying path 3 to the first sheet discharge portion 4; and a position where the sheet conveyed on the first sheet conveying path 3 from the sheet input port 2 side is branched from the first sheet conveying path 3 and guided to the third sheet conveying path 7. The switching guide 32 is connected to a driving mechanism (not shown), and the operation of the switching guide 32 is controlled by the post-processing control unit 10.

[0017] A retracting roller 33 is disposed below the first sheet conveying path 3. While a preceding sheet is being subjected to a predetermined post-processing, the succeeding sheet is retracted along the outer peripheral surface of the retracting roller 33. This improves the processing efficiency when the sheets are continuously post-processed.

[0018] The first sheet discharge section 4 is provided on the side surface of the sheet post-processing apparatus 1 opposite to the side surface facing the image forming apparatus 200 . The first sheet discharge section 4 includes a first discharge roller pair 42 and a first discharge tray 43 .

[0019] The first discharge roller pair 42 is arranged at the downstream end of the first sheet conveying path 3 in the sheet conveying direction. The first discharge tray 43 is located on the downstream side of the first discharge roller pair 42 in the sheet conveying direction. The sheet conveyed along the first sheet conveying path 3 and reaching the downstream end of the first sheet conveying path 3 in the sheet conveying direction is discharged by the first discharge roller pair 42 onto the first discharge tray 43. The first discharge tray 43 is one of the final discharge positions of the sheet that has been post-processed by the sheet post-processing device 1.

[0020] The second sheet conveying path 5 branches upward from the first sheet conveying path 3 and extends in a direction away from the image forming apparatus 200 ( Figure 2 The second sheet conveying path 5 branches off near the downstream side of the upstream conveying roller pair 31 in the sheet conveying direction of the first sheet conveying path 3. In addition, the direction from the upstream conveying roller pair 31 toward the second sheet discharge section 6 is referred to as the sheet conveying direction of the second sheet conveying path 5. The second sheet conveying path 5 has a plurality of conveying roller pairs, which branches off the sheet conveyed along the first sheet conveying path 3 and conveys it toward the second sheet discharge section 6.

[0021] The second sheet discharge section 6 is provided on the side of the sheet post-processing apparatus 1 opposite to the side facing the image forming apparatus 200 and is located above the first sheet discharge section 4 . The second sheet discharge section 6 includes a second discharge roller pair 62 and a second discharge tray 63 .

[0022] The second discharge roller pair 62 is arranged at the downstream end of the second sheet conveying path 5 in the sheet conveying direction. The second discharge tray 63 is located on the downstream side of the second discharge roller pair 62 in the sheet conveying direction. The sheet that has been conveyed along the second sheet conveying path 5 and has reached the downstream end of the second sheet conveying path 5 in the sheet conveying direction is discharged by the second discharge roller pair 62 onto the second discharge tray 63. The second discharge tray 63 is one of the final discharge positions of the sheet that has been post-processed by the sheet post-processing device 1. In addition, sheets that are not post-processed or small-sized sheets are also discharged to the second discharge tray 63.

[0023] The third sheet conveying path 7 branches downward from the first sheet conveying path 3 and extends downward to the third sheet discharge section 8. The third sheet conveying path 7 branches at a position on the downstream side of the branching portion of the second sheet conveying path 5 in the sheet conveying direction of the first sheet conveying path 3. In addition, the direction from the branching portion of the first sheet conveying path 3 toward the third sheet discharge section 8 is referred to as the sheet conveying direction of the third sheet conveying path 7. The third sheet conveying path 7 has a plurality of conveying roller pairs, which branches the sheet conveyed along the first sheet conveying path 3 and conveys it toward the binding section 94 and the third sheet discharge section 8.

[0024] The third sheet discharge section 8 is provided on the side of the sheet post-processing apparatus 1 opposite to the side facing the image forming apparatus 200 and is located below the first sheet discharge section 4 (near the lower end of the sheet post-processing apparatus 1). The third sheet discharge section 8 includes a third discharge roller pair (not shown) and a third discharge tray 83.

[0025] The sheet conveyed along the third sheet conveying path 7 and reaching the downstream end of the third sheet conveying path 7 in the sheet conveying direction is discharged by the third discharge roller pair onto the third discharge tray 83. The third discharge tray 83 is one of the final discharge positions of the sheets post-processed by the sheet post-processing apparatus 1.

[0026] The punching section 91 is arranged near the downstream side of the sheet input port 2 of the first sheet conveying path 3. The punching section 91 performs a punching process on the sheet conveyed on the first sheet conveying path 3 to form punched holes. A recovery container 911 is arranged below the punching section 91. Sheet scraps generated by the punching process of the punching section 91 fall from the first sheet conveying path 3 and are recovered in the recovery container 911. The recovery container 911 is removable relative to the sheet post-processing device 1.

[0027] The sheet binding unit 92 is arranged near the upstream side of the first sheet discharge portion 4 in the sheet conveying direction of the first sheet conveying path 3. The sheet binding unit 92 performs stapling processing (binding processing) on ​​a sheet bundle formed by stacking a plurality of sheets, thereby binding the sheet bundle. The detailed structure of the sheet binding unit 92 will be described later.

[0028] The binding section 94 is arranged near the upstream side of the third sheet discharge section 8 in the sheet conveying direction of the third sheet conveying path 7. The binding section 94 performs a center folding process and a center binding process on a sheet bundle formed by stacking a plurality of sheets and binding them substantially in the center in the sheet conveying direction to form a booklet.

[0029] The punching unit 91 , the sheet binding unit 92 , and the stapling unit 94 serve as post-processing units that perform predetermined post-processing on the sheet on which the image is formed by the image forming apparatus 200 and which is input into the sheet post-processing apparatus 1 .

[0030] The post-processing control unit (control unit) 10 includes a CPU, a storage unit, and other electronic circuits and electronic components (none of which are shown in the figure). The post-processing control unit 10 and the main body control unit 203 of the image forming apparatus 200 (see Figure 1) are connected in a communicative manner. The post-processing control unit 10 receives instructions from the main body control unit 203, uses the CPU and based on the control program and data stored in the storage unit, controls the actions of each component provided in the sheet post-processing device 1, and performs processing related to the function of the sheet post-processing device 1. The first sheet conveying path 3, the first sheet discharge unit 4, the second sheet conveying path 5, the second sheet discharge unit 6, the third sheet conveying path 7, the third sheet discharge unit 8, the punching unit 91, the sheet binding unit 92, and the binding unit 94 each receive instructions from the post-processing control unit 10, and perform post-processing on the sheets in a linked manner. In addition, the function of the post-processing control unit 10 can also be concurrently performed by the main body control unit 203 of the image forming device 200.

[0031] (3. Structure of sheet binding unit) Next, the structure of the sheet binding unit 92 will be described. Figure 3 It is a perspective view of the sheet stapling unit 92 installed in the sheet post-processing apparatus 1 . Figure 4 is a side view of the sheet binding unit 92 .

[0032] like Figure 3 As shown, the sheet binding unit 92 includes a processing tray 521 , a binding section 71 , and a reference plate 73 .

[0033] The processing tray 521 is a rectangular tray extending in the sheet width direction (arrow AA' direction) and the feeding direction. A plurality of sheets (sheet bundles) to be stapled can be loaded on the processing tray 521. Figure 4 The sheet bundle subjected to the stapling process is finally fed to the processing tray 521 in the alignment direction (the opposite direction of the feeding direction) toward the lower right (the direction of the arrow B). Figure 2 ) is oriented in the opposite direction to the above alignment direction ( Figure 4 ) and sent to the first discharge tray 43 (refer to Figure 2 ) is discharged. On the downstream side of the input direction of the processing tray 521 ( Figure 3 On the lower left side thereof, a discharge lower roller 421 constituting the first discharge roller pair 42 is supported.

[0034] The processing tray 521 includes a tray center portion 522 and a width restricting member 523. The tray center portion 522 is disposed at the center of the sheet width direction on the upper surface of the processing tray 521. The tray center portion 522 is a thin plate-shaped member having a small height and fixed to the processing tray 521.

[0035] A pair of width limiting components 523 are arranged across the tray center portion 522 in the sheet width direction. The width limiting components 523 limit the position of the sheet input to the processing tray 521 in the sheet width direction. The width limiting components 523 are composed of thin plate-like components like the tray center portion 522, and have side walls erected upward at the ends in the sheet width direction. A guide groove 524 extending in the sheet width direction is formed on the processing tray 521. The width limiting components 523 can reciprocate along the guide groove 524 in the sheet width direction via a drive mechanism (not shown) such as a rack and pinion. In the present embodiment, each time a sheet is input to the processing tray 521, the width limiting components 523 are reciprocated by the drive mechanism. As a result, the sheets loaded on the processing tray 521 are aligned in the sheet width direction.

[0036] The staple portion 71 is aligned with the front end side of the sheet ( Figure 4 The binding unit 71 can use the driving force of the binding unit driving motor M1 to move along the end edge of the sheet in the sheet width direction (arrow AA' direction) orthogonal to the input direction to perform binding processing on the bundle of sheets.

[0037] like Figure 4 As shown, the stapling section 71 includes: a stapling main body 711 and a stapling movable part 712. The stapling main body 711 is the main part of the stapling section 71, and contains a plurality of staples (not shown). The stapling movable part 712 can move up and down to drive staples into the sheet. A recess 713 is formed between the stapling main body 711 and the stapling movable part 712 for the end edge of the sheet to enter.

[0038] The reference plate 73 is aligned with the downstream side of the processing tray 521 ( Figure 3 The upper right side of Figure 4 The reference plate 73 is fixed at three locations spaced apart in the sheet width direction in a manner opposite to the end portion of the sheet (lower right side). Figure 4 The reference plate 73 is in a substantially U-shape that is open on the upper left side of the tray 521. The reference plate 73 abuts against the edge of the sheet fed to the processing tray 521 to align the sheet in the feeding direction.

[0039] (4. Configuration of the First Sheet Conveying Path from the Sheet Input Port to the First Sheet Discharging Port) Figure 5 1 is a side cross-sectional view showing the structure of the first sheet conveying path 3 from the sheet input port 2 to the first sheet discharge portion 4 of the sheet post-processing apparatus 1. Figure 5 The following describes the operation of the sheet S input from the sheet input port 2 , passing through the punching portion 91 and the sheet binding unit 92 , and being discharged from the first sheet discharge portion 4 .

[0040] like Figure 5 As shown, a sheet detection sensor 53 is arranged near the sheet input port 2. The sheet detection sensor 53 detects when the sheet S passes through the sheet input port 2. As the sheet detection sensor 53, for example, a PI (photo interrupter) sensor is used, which has a detection unit composed of a light emitting unit and a light receiving unit.

[0041] An intermediate conveying roller pair 54 is disposed above the processing tray 521. The intermediate conveying roller pair 54 is composed of an upper conveying roller 54a and a lower conveying roller 54b. An alignment member 55 is provided below the intermediate conveying roller pair 54.

[0042] Figure 6 54 is a perspective view of the intermediate conveying roller pair 54 and the alignment member 55. The intermediate conveying roller pair 54 is arranged at multiple locations (two locations in this embodiment) along the width direction of the sheet. A drive input gear 542 is fixed to the rotating shaft 541 of the conveying upper roller 54a. By turning the roller drive motor M2 (see Figure 5 ) is input to the drive input gear 542, thereby rotating the upper conveying roller 54a. In addition, the lower conveying roller 54b pressed against the upper conveying roller 54a is driven by the upper conveying roller 54a to rotate.

[0043] The alignment member 55 is aligned with the processing tray 521 (see Figure 5 ) moves the sheet S fed from the top of the sheet 55 toward the alignment direction close to the reference plate 73 (zigzag path), thereby assisting the alignment of the sheet S. The alignment member 55 includes a shaft 551 and an alignment paddle 552.

[0044] The shaft 551 is arranged parallel to the rotating shaft 541 of the upper conveying roller 54a. The alignment paddles 552 are fixed to multiple locations (two locations in this embodiment) of the shaft 551. The alignment paddles 552 are rubber sheets and protrude from positions of the shaft 551 that are in the same phase in the circumferential direction in the wiring direction.

[0045] A drive transmission gear 553 is fixed to the shaft 551 at a position meshing with the drive input gear 542. Thus, the rotational driving force of the roller drive motor M2 is transmitted to the shaft 551 via the drive input gear 542 and the drive transmission gear 553, and the alignment paddle 552 is rotated. More specifically, the alignment paddle 552 is directed in the direction in which the sheet S is fed in the alignment direction by the roller drive motor M2 ( Figure 5 The alignment paddle 552 contacts the upper surface of the sheet S input to the processing tray 521 and rotates, thereby moving the sheet S in the alignment direction and aligning the end edge of the sheet S against the reference plate 73.

[0046] As the roller drive motor M2, a stepping motor can be used, which can control the rotation direction and the rotation amount (rotation angle) with high accuracy by pulse control.

[0047] In addition, a home position detection unit 58 is provided to detect a reference position (home position) of the alignment member 55 (alignment paddle 552 ). The home position detection unit 58 includes a sensor unit 56 and a detection plate 57 .

[0048] Figure 7 yes Figure 6 58 is an enlarged view of the vicinity of the home position detection unit 58 in FIG. The sensor unit 56 is a transmissive PI (photointerrupter) sensor, and has a detection unit 56a in which a light emitting unit and a light receiving unit are arranged opposite to each other. The detection plate 57 is fixed to the end of the shaft 551. The sensor unit 56 is arranged in such a way that the detection unit 56a clamps the outer peripheral edge of the detection plate 57.

[0049] A notch 57a is formed on the outer periphery of the detection plate 57. The notch 57a is formed at a position where the output of the sensor unit 56 changes when the rotation angle of the shaft 551 reaches the reference angle. The output of the detection unit 56a when the detection plate 57 rotates is the output of the home position detection unit 58. The output of the detection unit 56a is sent to the post-processing control unit 10 as a detection signal. The post-processing control unit 10 detects based on the output of the home position detection unit 58 that the phase (rotation position) of the alignment paddle 552 is at the home position.

[0050] Figure 8 5 is a side cross-sectional view showing the structure around the alignment member 55, showing the state of the alignment paddle plate 552 in the original position. Figure 8 As shown, the position where the alignment paddle 552 is retracted from the first sheet conveying path 3 is set to the home position, more specifically, the upstream side ( Figure 8 A position where the alignment paddle 552 protrudes substantially parallel to the first sheet conveying path 3 (on the right side) is set as the home position of the alignment paddle 552.

[0051] In addition, the original position detection unit 58 can detect the phase (rotational position) of the alignment paddle 552 without being limited to the following. Figure 7 The structure having the sensor portion 56 and the detection plate 57 as shown may also be another structure.

[0052] (5. Phase adjustment control of the paddle board) Next, the phase adjustment control of the alignment paddle 552 is described. Figure 6As shown, in the configuration of this embodiment, the alignment member 55 is disposed close to below the intermediate conveying roller pair 54. Therefore, the rotation trajectory of the alignment paddle 552 overlaps with the first sheet conveying path 3 (the conveying trajectory of the sheet S passing through the intermediate conveying roller pair 54).

[0053] Fig. 9 5 shows the state where the paddle plate 552 is in contact with the rear end of the sheet S. Fig. 9 As shown, depending on the phase (rotational position) of the alignment paddle 552, the alignment paddle 552 may contact the rear end of the sheet S being conveyed along the first sheet conveying path 3, and press the sheet S in the conveying direction. As a result, when the sheet S is pulled onto the processing tray 521, it may not be pulled into the desired position, making it difficult to achieve stable conveyance and alignment of the sheet S.

[0054] Therefore, in the present embodiment, when there is a high possibility that the sheet S being conveyed along the first sheet conveying path 3 will contact the alignment paddle 552 , the contact with the sheet S is prevented by shifting the phase of the alignment paddle 552 .

[0055] Specifically, the post-processing control unit 10 calculates a section (hereinafter referred to as the expected contact section) in which the rear end of the sheet S may contact the alignment paddle 552. Furthermore, when the moment (hereinafter referred to as the interference moment) at which the alignment paddle 552 interferes (overlaps) with the first sheet conveying path 3 due to the rotation of the alignment member 55 is within the expected contact section, the post-processing control unit 10 sends a control signal to the roller drive motor M2 to temporarily decelerate (or accelerate) the rotation speed of the alignment member 55 (shaft 551).

[0056] Fig.10 The phase of the alignment paddle 552 is shifted. By temporarily slowing down (or accelerating) the rotation speed of the alignment member 55, Fig.10 As shown in the figure, the phase of the alignment paddle 552 is shifted to a position (solid line position) at a predetermined angle from the position (dashed line position) before deceleration (or acceleration). In this way, when the interference moment of the alignment paddle 552 coincides with the expected contact interval, the phase of the alignment paddle 552 is shifted so that the interference moment is outside the expected contact interval, thereby preventing the alignment paddle 552 from contacting the rear end of the sheet S.

[0057] The interference timing of the alignment paddle plate 552 can be calculated based on the output of the home position detection unit 58. Specifically, the time when the alignment paddle plate 552 is in the home position (see Figure 8 ) time, therefore, according to the position from the home position to the position interfering with the first sheet conveying path 3 (refer to Fig. 9 ) to calculate the interference timing.

[0058] The expected contact interval can be calculated based on the conveying speed of the sheet S in the image forming apparatus 200 and the sheet post-processing apparatus 1, the size of the sheet S in the conveying direction, and the conveying distance, and using a calculation formula stored in advance in the storage unit of the post-processing control unit 10. The expected contact interval also depends on the conditions such as the conveying speed of the image forming apparatus 200 and the sheet post-processing apparatus 1. If expressed in terms of distance (mm), it is a few millimeters to more than ten millimeters. In addition, the expected contact interval can also be expressed in terms of time (seconds).

[0059] In addition, when the sheet S is punched by the punching unit 91, or when the front end of the sheet S is brought into contact with the upstream conveying roller pair 31 to perform positioning correction (skew correction) to bend the sheet S, it is necessary to consider the time required for the punching process and the time required for the bend to form and eliminate the bend. That is, when a prescribed post-processing is performed on the upstream side of the alignment paddle 552, it is necessary to consider the time required for the post-processing (post-processing time) to calculate the expected contact interval.

[0060] In addition, by changing the parameters of the calculation formula when designing the sheet post-processing device 1, the length of the expected contact interval generated can also be changed. For example, in the case where it is desired to more reliably prevent the alignment paddle 552 from contacting the rear end of the sheet S, the parameters of the calculation formula are changed in a manner that extends the calculated expected contact interval. On the other hand, in the case where it is desired to avoid frequent phase adjustment control of the alignment paddle 552, the parameters of the calculation formula are changed in a manner that shortens the calculated expected contact interval.

[0061] Fig.11 This is a flowchart showing an example of phase adjustment control of the paddle plate 552 executed in the sheet post-processing apparatus 1 of this embodiment. Figures 1 to 10 And follow Fig.11 The phase adjustment process of the paddle 552 is described with reference to the steps. In the following description, the size of the sheet S, the conveying speed, and the information related to the post-processing performed on the sheet S are referred to as the output information of the sheet S.

[0062] When a binding processing instruction for the sheet S is input from the main body control unit 203 of the image forming apparatus 200, output information of the sheet S is input together with the binding processing instruction (step S1). Information related to the size of the sheet S among the output information of the sheet S is input from the operation panel 202 of the image forming apparatus 200. For example, the manufacturer, product name, product number, etc. of the sheet S may be associated with the type-related information of the corresponding sheet S and stored in advance in the main body control unit 203. Thus, as long as the user selects the manufacturer, product name, product number, etc. of the sheet S from the operation panel 202, the main body control unit 203 can recognize the information related to the size of the sheet S to be used.

[0063] Information on the conveyance speed of the sheet S in the image forming apparatus 200 is transmitted by the main body control unit 203 based on the printing mode (photo printing mode, text printing mode, double-sided printing mode, etc.) input from a host device such as a personal computer or the operation panel 202 .

[0064] Information on post-processing performed on the sheet S is transmitted by the main body control unit 203 based on the post-processing content (binding processing, punching processing, registration correction, etc.) input from a host device such as a personal computer or the operation panel 202 .

[0065] The post-processing control unit 10 calculates the expected contact section of the alignment paddle 552 with the sheet S based on the input output information of the sheet S (step S2 ). Thereafter, the conveyance of the sheet S is started (step S3 ).

[0066] Next, the post-processing control unit 10 detects the home position of the alignment paddle 552 (step S4). Specifically, when the sheet detection sensor 53 detects the input of the sheet S, the post-processing control unit 10 sends a control signal to the roller drive motor M2 to rotate the intermediate conveying roller pair 54 and the alignment member 55 at a reference speed. And, based on the output of the home position detection unit 58, the time when the alignment paddle 552 is in the home position is detected.

[0067] Next, the post-processing control unit 10 determines whether the phase (rotational position) of the alignment paddle 552 needs to be corrected (step S5). Specifically, based on the expected contact interval calculated in step S2 and the original position of the alignment paddle 552 detected in step S4, it is determined whether the interference timing of the alignment paddle 552 coincides with the expected contact interval when the intermediate conveying roller pair 54 and the alignment member 55 are rotated at the reference speed.

[0068] When the interference timing of the alignment paddle 552 coincides with the expected contact interval, it is determined that the phase of the alignment paddle 552 needs to be corrected. The determination of whether the phase of the alignment paddle 552 needs to be corrected is made in the interval after the front end of the sheet S is detected by the sheet detection sensor 53 and before the front end of the sheet S reaches the upstream conveying roller pair 31 ( Figure 5 R1) is carried out.

[0069] When it is determined that the phase of the alignment paddle 552 needs to be corrected (Yes in step S5), the post-processing control unit 10 sends a control signal to the roller drive motor M2 to decelerate the rotation speed of the roller drive motor M2, thereby decelerating the alignment member 55 from the reference speed (step S6). Thereafter, the alignment member 55 is restored to the reference speed (step S7).

[0070] In this embodiment, the roller drive motor M2 is used as a common drive source for the intermediate conveying roller pair 54 and the alignment member 55. Therefore, when the roller drive motor M2 is decelerated, not only the alignment member 55 but also the intermediate conveying roller pair 54 is decelerated. Therefore, the action of decelerating the alignment member 55 from the reference speed and returning to the reference speed is performed in the interval after the leading end of the sheet S passes through the upstream conveying roller pair 31 and before the leading end of the sheet S reaches the intermediate conveying roller pair 54 ( Figure 5 R2) is carried out.

[0071] On the other hand, when it is determined that the phase of the alignment paddle 552 does not need to be corrected (NO in step S5 ), the rotation speed of the roller drive motor M2 is not changed and the alignment member 55 continues to rotate at the reference speed (step S8 ).

[0072] The sheet S that has passed through the intermediate conveying roller pair 54 is knocked downward by a knocking member (not shown) and falls onto the processing tray 521. The sheet S that has fallen onto the processing tray 521 is pulled into the alignment direction ( Figure 3 , Figure 4 The width limiting member 523 (see arrow B direction) is used. Figure 3 ) are aligned in the sheet width direction and are aligned using a reference plate 73 (reference Figure 3 ) are aligned in the input direction and loaded.

[0073] Next, the post-processing control unit 10 determines whether a predetermined number of sheets S are input to the processing tray 521 (step S9). If a predetermined number of sheets S are not input (No in step S9), the process returns to step S2 and the above-mentioned flow is repeated (steps S2 to S8).

[0074] When a predetermined number of sheets S are input (YES in step S9), the post-processing control unit 10 drives the binding unit driving motor M1 (see Figure 3 ) to move the binding unit 71 to the specified binding position. After the binding unit 71 moves to the specified binding position, the post-processing control unit 10 sends a control signal to the binding unit 71 to perform binding processing on the plurality of sheets S aligned by the reference plate 73 (step S10), and ends the phase adjustment control of the alignment paddle plate 552.

[0075] according to Fig.11 In the control example shown, when the expected contact interval calculated based on the output information of the sheet S coincides with the interference timing of the alignment paddle 552, the phase of the alignment paddle 552 is appropriately corrected. Thus, the alignment paddle 552 can be prevented from squeezing the sheet S, and the sheet S can be stably conveyed and aligned on the processing tray 521.

[0076] In addition, since it is not necessary to stop the rotation of the alignment member 55 , it is possible to reduce the influence on the alignment of the sheets S loaded on the processing tray 521 .

[0077] In addition, the alignment member 55 and the intermediate conveying roller pair 54 are driven by the same driving source (roller driving motor M2 ), so that the manufacturing cost can be reduced and the device can be miniaturized.

[0078] In addition, before the sheet S reaches the intermediate conveying roller pair 54, the phase of the alignment paddle 552 is corrected by decelerating (or accelerating) the alignment member 55, and the operation of returning the alignment member 55 to the reference speed is completed. Thus, when the roller drive motor M2 is used as a common driving source for the intermediate conveying roller pair 54 and the alignment member 55, the conveyance of the sheet S can be prevented from being affected by the change in the rotation speed of the intermediate conveying roller pair 54.

[0079] In addition, the output information of the sheet S includes the content of post-processing such as the punching process and the positioning correction performed by the punching unit 91, so that an appropriate expected contact interval can be calculated in consideration of the content of the post-processing performed on the upstream side of the sheet binding unit 92. Therefore, the rear end of the sheet S can be more reliably prevented from contacting the alignment paddle 552.

[0080] The above is a description of the embodiment of the present invention, but the scope of the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the alignment member 55 is provided below the intermediate conveying roller pair 54, but the alignment paddle 552 can also be installed on the rotating shaft of the conveying lower roller 54b of the intermediate conveying roller pair 54, so that the intermediate conveying roller pair 54 and the alignment member 55 are integrally formed.

[0081] In the above embodiment, the alignment paddle plate 552 is fixed to only one location in the circumferential direction of the shaft 551 , but the alignment paddle plate 552 may be fixed to a plurality of locations in the circumferential direction of the shaft 551 at equal intervals.

[0082] In addition, in the above-mentioned embodiment, the roller drive motor M2 is used as a common drive source for the intermediate conveying roller pair 54 and the alignment member 55, but the present invention can also be applied to a structure in which the intermediate conveying roller pair 54 and the alignment member 55 are driven by different drive sources. In this case, the action of decelerating the alignment member 55 from the reference speed and restoring it to the reference speed can also be performed after the leading end of the sheet S reaches the intermediate conveying roller pair 54.

[0083] In addition, in the above-mentioned embodiment, an example is shown in which the sheets S loaded on the processing tray 521 are bound by the sheet binding unit 92, but the present invention is not limited to this. It is also possible to have a structure in which the sheets S loaded on the processing tray 521 are shifted and discharged or folded back.

[0084] In the above-described embodiment, the output information related to the characteristics of the sheet S is input from the operation panel 202 of the image forming apparatus 200, but the output information of the sheet S may be automatically acquired. For example, a medium sensor may be arranged at any position of the sheet conveying path from the image forming apparatus 200 to the sheet post-processing apparatus 1, and the medium sensor may be used to detect the size of the sheet S input from the image forming apparatus 200 to the sheet post-processing apparatus 1.

[0085] In the above embodiment, an inkjet recording apparatus is exemplified as the image forming apparatus 200 , but an electrophotographic printer or a copying machine may be used as the image forming apparatus 200 .

[0086] The present invention can be applied to a sheet post-processing apparatus that performs predetermined post-processing on a plurality of sheets.

Claims

1. A sheet post-processing device, comprising: a first conveying member that conveys a sheet; a processing tray on which the plurality of sheets fed in along a prescribed feeding direction by the first feeding member are loaded; a first processing unit that performs a predetermined post-processing on the sheet loaded on the processing tray; a reference plate that contacts an end edge of the sheet fed onto the processing tray in a direction opposite to the feeding direction, that is, in a downstream direction of an alignment direction, so as to align the sheet in the feeding direction; an alignment member having a shaft and one or more alignment paddles, wherein the shaft is arranged above the processing tray and rotates, the alignment paddles protrude in the radial direction of the shaft and contact the sheet material input onto the processing tray, and the alignment member rotates in the alignment direction on a surface opposite to the processing tray, thereby moving the sheet material input onto the processing tray in the alignment direction, thereby assisting in the alignment of the sheet material; An original position detection unit, which detects that the alignment paddle is in a reference position; a driving unit that drives the alignment component; as well as a control unit that controls the driving unit, The sheet post-processing device is characterized in that: The control unit calculates an expected contact section based on the output information of the sheet material, wherein the expected contact section has a possibility that the rear end of the sheet material input in the input direction will contact the alignment paddle. The control unit calculates the interference timing of the alignment paddle and the sheet material feeding path based on the detection result of the home position detection unit, When the interference timing is within the expected contact interval, the control unit temporarily changes the rotation speed of the alignment member from a reference speed to change the phase of the alignment paddle so that the interference timing is outside the expected contact interval.

2. The sheet post-processing device according to claim 1, characterized in that: The device comprises one driving unit, which drives the alignment member and the first conveying member to rotate. The control unit temporarily changes the rotation speed of the alignment member from the reference speed and then returns the rotation speed of the alignment member to the reference speed before the sheet reaches the first conveying member.

3. The sheet post-processing device according to claim 1, characterized in that: The output information of the sheet includes: a size, a conveying speed, and a conveying distance of the sheet in the conveying direction.

4. The sheet post-processing device according to claim 1, characterized in that: The processing tray is provided with one or more second processing units for performing a predetermined post-processing on the sheet, on the upstream side of the processing tray in the conveying direction of the sheet. The output information of the sheet includes time required for post-processing by the second processing unit.

5. The sheet post-processing device according to claim 1, characterized in that: A sheet detection unit is provided, the sheet detection unit is arranged on the upstream side of the first conveying member in the conveying direction of the sheet, and detects the passage of the sheet. The control unit calculates the interference timing after the sheet detection unit detects the passage of the sheet.

6. The sheet post-processing device according to claim 5, characterized in that: A second conveying member is provided, the second conveying member is arranged on the downstream side of the sheet detection portion and on the upstream side of the first conveying member in the conveying direction, and conveys the sheet in the conveying direction. The control unit determines whether the interference timing is within the expected contact section in a section after the leading end of the sheet is detected by the sheet detection unit and before the leading end of the sheet reaches the second conveying member.

7. The sheet post-processing device according to claim 6, characterized in that: The control unit changes the rotation speed of the alignment member from the reference speed after the leading end of the sheet passes through the second conveying member, and returns the rotation speed of the alignment member to the reference speed before the sheet reaches the first conveying member.

8. The sheet post-processing device according to claim 1, characterized in that: The control unit calculates the expected contact interval using a preset calculation formula, The calculated length of the expected contact section can be adjusted by changing the parameter of the calculation formula.

9. An image forming system comprising: an image forming device that forms an image on a sheet; and The sheet post-processing device according to any one of claims 1 to 8, which performs a predetermined post-processing on the sheet on which the image is formed by the image forming device.

10. The image forming system according to claim 9, wherein: The output information of the sheet includes a conveyance speed of the sheet in the image forming apparatus.

Images