Sheet post-processing device and image forming device including the same

Abstract

To provide a sheet post-processing device capable of preventing contact between the rear end of a sheet conveyed onto a processing tray and an alignment member and improving the alignment of the sheet, and an image forming system including the same.SOLUTION: A sheet post-processing device includes: a first conveyance member; a processing tray; a first processing part; a reference plate; an alignment member; a home position detection part; and a control part. The alignment member has a shaft that rotates connected to a drive part, and one or more alignment paddles that protrude in a radial direction of the shaft and contact a sheet conveyed onto the processing tray. The control part calculates: an assumed contact section in which a real edge of the sheet may come into contact with the alignment paddle and an interference timing at which the alignment paddle interferes with a sheet carrying-in route. When the interference timing is inside the assumed contact section, the control part temporarily changes a rotation speed of the alignment member from a reference speed to change a phase of the alignment paddle so that the interference timing is outside the assumed contact section.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a sheet post-processing device that performs a predetermined post-processing on a sheet on which an image has been formed by an image forming apparatus, and an image forming system including the same. [Background technology]

[0002] There are known sheet post-processing devices that stack multiple sheets after images have been formed on them by an image forming device such as a copier or printer, and perform a binding process in which the stacked sheet bundle is bound together with staples, a punch hole forming process in which punch holes (perforations) are made using a punch hole forming device, and a folding process in which creases are formed in the sheets.

[0003] In such a sheet post-processing device, a processing tray is provided on which a predetermined number of sheets on which images are formed are stacked. Then, the multiple sheets stacked on the processing tray are subjected to a binding process, a shift discharge process (sorting process), etc. In order to smoothly perform the binding process, the shift discharge process, etc., the sheets on the processing tray are aligned using an alignment member such as an alignment paddle.

[0004] Patent document 1 discloses a sheet processing device including an inclined tray that receives and stacks transported sheets, a stopper that aligns the sheets by aligning the trailing ends of the sheets stacked on the inclined tray, and an alignment rotor that applies a predetermined conveying force to sheets sequentially supplied to the inclined tray to press the sheets against the stopper.

[0005] In the sheet processing device of Patent Document 1, it is determined whether the sheet material at the position to be punched has reached a handover position between the first transport roller and the second transport roller, and if it is determined that the sheet material has not yet reached the handover position, the second motor is continued to operate, and if it is determined that the sheet material has reached the handover position, the second motor is temporarily stopped.

[0006] According to the configuration of Patent Document 1, when a motor is used as a drive source for the second transport roller and the alignment rotator, the alignment rotator does not stop if the preceding sheet material has not reached the position of the alignment rotator on the inclined tray. Therefore, when the alignment rotator rotates again from a stopped state, there is no risk of the sheet material being bounced diagonally upward or being blocked, and it is possible to suppress misalignment of the sheet material. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2017-36115 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, when the rotation path of the alignment member and the conveying path of the sheet conveyed by the conveying roller pair overlap, depending on the phase (rotation position) of the alignment member, the alignment member may come into contact with the rear end of the sheet being conveyed and push the sheet in the conveying direction. As a result, the sheet is not conveyed to the specified conveying position, resulting in problems such as poor drawing into the processing tray and poor alignment.

[0009] In view of the above problems, the present invention aims to provide a sheet post-processing device and an image forming system equipped with the same that can improve sheet alignment by avoiding contact between the rear end of a sheet transported onto a processing tray and an alignment member. [Means for solving the problem]

[0010] In order to achieve the above object, a first configuration of the present invention is a sheet post-processing device including a first conveying member, a processing tray, a first processing section, a reference plate, an alignment member, a home position detection section, and a control section. The first conveying member conveys a sheet. The processing tray is stacked with a plurality of sheets that are carried in along a predetermined carry-in direction by the first conveying member. The first processing section performs a predetermined post-processing on the sheets stacked on the processing tray. The reference plate abuts against an edge downstream of the alignment direction, which is the opposite direction to the carry-in direction of the sheet carried in to the processing tray, to align the sheet in the carry-in direction. The alignment member is disposed above the processing tray, and has a shaft that is connected to a drive section and rotates, and one or more alignment paddles that protrude in the radial direction of the shaft and contact the sheet carried in to the processing tray, and rotates in the alignment direction on the surface facing the processing tray to move the sheet carried in to the processing tray in the alignment direction to assist in aligning the sheet. The home position detection section detects that the alignment paddle is at a reference position. The control section controls the drive section. The control unit calculates an expected contact zone where the rear end of the sheet being fed in along the feed direction may come into contact with the alignment paddle based on the sheet output information. The control unit calculates an interference timing where the alignment paddle interferes with the feed path of the sheet based on the detection result of the home position detection unit. If the interference timing is within the expected contact zone, 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 zone. Effect of the Invention

[0011] According to the first configuration of the present invention, when the expected contact section calculated based on the output information of the sheet and the interference timing of the alignment paddle overlap, the phase of the alignment paddle is appropriately corrected. This makes it possible to suppress the pushing of the sheet by the alignment paddle, and to stably transport the sheet and align it on the processing tray. In addition, since there is no need to stop the rotation of the alignment member, the effect on the alignment of the sheets loaded on the processing tray can be reduced. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an image forming system including a sheet post-processing device 1 according to an embodiment of the present invention and an image forming device 200 to which the sheet post-processing device 1 is connected; [Diagram 2] FIG. 1 is a side cross-sectional view showing a schematic configuration of a sheet post-processing device 1 according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a perspective view of a sheet binding unit 92 mounted in the sheet post-processing device 1 of the present embodiment; [Figure 4] A side view of the sheet binding unit 92 [Diagram 5] FIG. 2 is a side cross-sectional view showing the configuration of a first sheet transport path 3 from a sheet entrance 2 to a first sheet discharge section 4 of the sheet post-processing device 1. [Figure 6] 5 is a perspective view of the intermediate conveying roller pair 54 and the alignment member 55. [Figure 7] An enlarged view of the home position detection unit 58 and its surroundings in FIG. [Figure 8] FIG. 1 is a side cross-sectional view showing the structure around the alignment member 55, showing a state in which the alignment paddle 552 is in the home position. [Figure 9] FIG. 13 is a side cross-sectional view showing the structure around the processing tray 521 and the alignment member 55, illustrating a state in which the alignment paddle 552 contacts the rear end of the sheet S. [Figure 10] FIG. 13 is a side cross-sectional view showing the structure around the processing tray 521 and the alignment member 55, illustrating a state in which contact with the rear end of the sheet S is avoided by shifting the phase of the alignment paddle 552. [Figure 11] A flowchart showing an example of phase adjustment control of the alignment member 55 in the sheet post-processing device 1 of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [1. Image formation system configuration] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of an image forming system including a sheet post-processing device 1 according to an embodiment of the present invention and an image forming device 200 to which the sheet post-processing device 1 is connected.

[0014] 1, 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 device provided with a recording head (not shown) for each color, the recording head having a large number of nozzle holes for ejecting ink onto the sheet.

[0015] An operation panel 202 is disposed in front of the image reading unit 201. The operation panel 202 is an operation unit for receiving various setting inputs. For example, a user can operate the operation panel 202 to input sheet size information. The user can also operate the operation panel 202 to input the number of sheets to be printed and to instruct the start of a print job. A main body control unit 203 supervises the operation of the entire image forming apparatus 200 and controls each unit of the image forming apparatus 200.

[0016] The sheet post-processing device 1 is detachably connected to a side surface of the image forming apparatus 200. The sheet post-processing device 1 performs post-processing such as punching (hole punching) and binding on sheets after an image is formed (printed) by the image forming apparatus 200. Note that the sheet post-processing device 1 is not limited to a device that performs post-processing on sheets automatically transported from the image forming apparatus 200, but may be a device that transports sheets set by a user on a tray (not shown) to a position where the sheets can be post-processed by itself and performs post-processing on the sheets.

[0017] [2. Configuration of sheet post-processing device] Fig. 2 is a side cross-sectional view showing a schematic configuration of the sheet post-processing device 1 of this embodiment. As shown in Fig. 2, the sheet post-processing device 1 includes a sheet entrance 2, a first sheet transport path 3, a first sheet discharge section 4, a second sheet transport path 5, a second sheet discharge section 6, a third sheet transport path 7, a third sheet discharge section 8, a hole punching section 91, a sheet binding unit 92, a binding section 94, and a post-processing control section (control section) 10.

[0018] The sheet entrance 2 is an opening provided on the side of the sheet post-processing device 1 facing the image forming device 200. A sheet conveyed from the image forming device 200 toward the sheet post-processing device 1 passes through the sheet entrance 2 and is carried into the inside of the sheet post-processing device 1.

[0019] The first sheet transport path 3 extends substantially horizontally from the sheet entrance 2 to the first sheet discharge section 4 in a direction away from the image forming apparatus 200 (to the left in FIG. 2). The direction from the sheet entrance 2 toward the first sheet discharge section 4 is referred to as the sheet transport direction in the first sheet transport path 3. The sheet entrance 2 is located at the upstream end of the first sheet transport path 3 in the sheet transport direction. The first sheet transport path 3 has an upstream transport roller pair 31 and an intermediate transport roller pair 54, and transports a sheet carried into the sheet post-processing device 1 from the sheet entrance 2 toward the downstream side in the sheet transport direction.

[0020] Two switching guides 32 are disposed on the first sheet transport path 3. The switching guide 32 on the upstream side (right side in FIG. 1) in the sheet transport direction on the first sheet transport path 3 is disposed at a branching portion of the second sheet transport path 5 and rotates between a position where the sheet transported on the first sheet transport path 3 from the sheet entrance 2 side is guided along the first sheet transport path 3 to the first sheet discharge portion 4 and a position where the sheet is branched off from the first sheet transport path 3 and guided to the second sheet transport path 5.

[0021] The switching guide 32 on the downstream side (left side in FIG. 1) in the sheet conveying direction in the first sheet conveying path 3 is disposed at the branching portion of the third sheet conveying path 7, and rotates between a position where the sheet conveyed on the first sheet conveying path 3 from the sheet entrance 2 side is guided along the first sheet conveying path 3 to the first sheet discharge section 4, and a position where the sheet is branched off from the first sheet conveying path 3 and guided to the third sheet conveying path 7. The switching guide 32 is connected to a drive mechanism (not shown), and its operation is controlled by the post-processing control section 10.

[0022] A retraction roller 33 is disposed below the first sheet transport path 3. While a predetermined post-processing is being performed on the preceding sheet, the succeeding sheet is retracted along the outer circumferential surface of the retraction roller 33. This improves the processing efficiency when the sheets are successively subjected to post-processing.

[0023] The first sheet discharge section 4 is provided on the side of the sheet post-processing device 1 opposite to the side facing the image forming device 200. The first sheet discharge section 4 has a first discharge roller pair 42 and a first discharge tray 43.

[0024] The first discharge roller pair 42 is disposed at the downstream end of the first sheet transport path 3 in the sheet transport direction. The first discharge tray 43 is located downstream of the first discharge roller pair 42 in the sheet transport direction. The sheet transported through the first sheet transport path 3 and reaching the downstream end of the first sheet transport path 3 in the sheet transport direction is discharged onto the first discharge tray 43 by the first discharge roller pair 42. The first discharge tray 43 is one of the final discharge locations for the sheet that has been post-processed by the sheet post-processing device 1.

[0025] The second sheet transport path 5 branches upward from the first sheet transport path 3 and extends diagonally upward in a direction away from the image forming apparatus 200 (to the left in FIG. 2 ) to the second sheet discharge section 6. The second sheet transport path 5 branches immediately downstream of the upstream transport roller pair 31 with respect to the sheet transport direction in the first sheet transport path 3. The direction from the upstream transport roller pair 31 toward the second sheet discharge section 6 is referred to as the sheet transport direction in the second sheet transport path 5. The second sheet transport path 5 has multiple transport roller pairs, and branches the sheet transported in the first sheet transport path 3 to transport it toward the second sheet discharge section 6.

[0026] The second sheet discharge section 6 is provided above the first sheet discharge section 4 on the side of the sheet post-processing device 1 opposite to the side facing the image forming device 200. The second sheet discharge section 6 has a second discharge roller pair 62 and a second discharge tray 63.

[0027] The second discharge roller pair 62 is disposed at the downstream end of the second sheet transport path 5 in the sheet transport direction. The second discharge tray 63 is located downstream of the second discharge roller pair 62 in the sheet transport direction. The sheet transported through the second sheet transport path 5 and reaching the downstream end of the second sheet transport path 5 in the sheet transport direction is discharged onto the second discharge tray 63 by the second discharge roller pair 62. The second discharge tray 63 is one of the final discharge locations for sheets that have been post-processed by the sheet post-processing device 1. In addition, sheets that are not post-processed and small-sized sheets are also discharged to the second discharge tray 63.

[0028] The third sheet transport path 7 branches downward from the first sheet transport path 3 and extends downward to the third sheet discharge section 8. The third sheet transport path 7 branches downstream of the branching point of the second sheet transport path 5 with respect to the sheet transport direction in the first sheet transport path 3. The direction from the branching point of the first sheet transport path 3 toward the third sheet discharge section 8 is referred to as the sheet transport direction in the third sheet transport path 7. The third sheet transport path 7 has multiple transport roller pairs, and branches the sheet transported on the first sheet transport path 3 to transport it toward the binding section 94 and the third sheet discharge section 8.

[0029] The third sheet discharge section 8 is provided below the first sheet discharge section 4 (near the lower end of the sheet post-processing device 1) on the side of the sheet post-processing device 1 opposite to the side facing the image forming device 200. The third sheet discharge section 8 has a third discharge roller pair (not shown) and a third discharge tray 83.

[0030] The sheet that has been conveyed along the third sheet conveying path 7 and has reached the downstream end of the third sheet conveying path 7 in the sheet conveying direction is discharged onto a third discharge tray 83 by a third discharge roller pair. The third discharge tray 83 is one of the final discharge locations for the sheet that has been post-processed by the sheet post-processing device 1.

[0031] The punching section 91 is disposed immediately downstream of the sheet entrance 2 on the first sheet transport path 3. The punching section 91 performs a punching process on the sheet transported on the first sheet transport path 3 to form punch holes. A collection container 911 is disposed below the punching section 91. Sheet pieces generated by the punching process of the punching section 91 drop from the first sheet transport path 3 and are collected in the collection container 911. The collection container 911 is detachable from the sheet post-processing device 1.

[0032] The sheet binding unit 92 is disposed immediately upstream of the first sheet discharge section 4 in the sheet conveying direction of the first sheet conveying path 3. The sheet binding unit 92 staples (binds) a sheet bundle formed by stacking a plurality of sheets, and binds the sheet bundle. A detailed configuration of the sheet binding unit 92 will be described later.

[0033] The binding part 94 is disposed immediately upstream of the third sheet discharge unit 8 in the sheet conveying direction of the third sheet conveying path 7. The binding part 94 performs center folding and saddle stitching on a sheet bundle formed by stacking a plurality of sheets, in which the sheets are folded and bound at approximately the center in the sheet conveying direction, to form a booklet.

[0034] The punching section 91, the sheet binding unit 92, and the binding section 94 constitute a post-processing section that performs a predetermined post-processing on the sheets on which the images have been formed by the image forming apparatus 200 and which have been carried into the sheet post-processing device 1.

[0035] The post-processing control unit (control unit) 10 includes a CPU, a storage unit, and other electronic circuits and electronic components (all not shown). The post-processing control unit 10 is connected to the main body control unit 203 (see FIG. 1) of the image forming apparatus 200 so as to be able to communicate with it. The post-processing control unit 10 receives a command from the main body control unit 203, and controls the operation of each component provided in the sheet post-processing device 1 based on a control program and data stored in the storage unit using the CPU to perform processing related to the functions 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 a command individually from the post-processing control unit 10 and perform post-processing on the sheet in cooperation with each other. The function of the post-processing control unit 10 may also be performed by the main body control unit 203 of the image forming apparatus 200.

[0036] [3. Configuration of the sheet binding unit] Next, a description will be given of the configuration of the sheet binding unit 92. Fig. 3 is a perspective view of the sheet binding unit 92 mounted on the sheet post-processing device 1. Fig. 4 is a side view of the sheet binding unit 92.

[0037] As shown in FIG. 3, the sheet binding unit 92 includes a processing tray 521, a staple portion 71, and a reference plate 73.

[0038] The processing tray 521 is a rectangular tray extending in the sheet width direction (arrow AA′ direction) and the carry-in direction. A plurality of sheets (sheet stack) to be stapled are stacked on the processing tray 521. At this time, the sheets are carried into the processing tray 521 along an alignment direction (opposite to the carry-in direction) toward the lower right direction (arrow B direction) in FIG. 4. The stapled sheet stack is finally sent out in the opposite direction to the alignment direction (upper left direction in FIG. 4) by the first discharge roller pair 42 (see FIG. 2) and discharged to the first discharge tray 43 (see FIG. 2). A discharge lower roller 421 constituting the first discharge roller pair 42 is supported on the downstream side of the processing tray 521 in the carry-in direction (lower left side in FIG. 3).

[0039] The processing tray 521 includes a tray center portion 522 and a width regulating member 523. The tray center portion 522 is disposed in the center in the sheet width direction on the upper surface portion of the processing tray 521. The tray center portion 522 is a thin plate-like member that has a slight height and is fixed onto the processing tray 521.

[0040] A pair of width regulating members 523 are disposed to sandwich the tray center portion 522 in the sheet width direction. The width regulating members 523 regulate the position in the sheet width direction of the sheet carried into the processing tray 521. The width regulating member 523 is made of a thin plate-like member similar to the tray center portion 522, and has a side wall erected upward at the end portion in the sheet width direction. The processing tray 521 is formed with a guide groove 524 extending along the sheet width direction. The width regulating member 523 can be reciprocated in the sheet width direction along the guide groove 524 via a drive mechanism (not shown) such as a rack and pinion gear. In this embodiment, the width regulating member 523 is reciprocated by the drive mechanism every time a sheet is carried into the processing tray 521. As a result, the sheets stacked on the processing tray 521 are aligned in the sheet width direction.

[0041] The staple unit 71 is disposed to face the edge of the sheet on the leading edge side in the alignment direction (the right side in FIG. 4). The staple unit 71 can move in the sheet width direction (arrow AA' direction) perpendicular to the feed direction along the edge of the sheet by the driving force of the staple unit drive motor M1, and staples the stack of sheets.

[0042] As shown in Fig. 4, the staple portion 71 includes a staple body portion 711 and a staple movable portion 712. The staple body portion 711 is the main body of the staple portion 71, and houses a plurality of staples (not shown) therein. The staple movable portion 712 is movable up and down, and drives the staples into the sheet. A recess 713 is formed between the staple body portion 711 and the staple movable portion 712, into which the edge of the sheet enters.

[0043] The reference plate 73 is fixed at three locations spaced apart in the sheet width direction so as to face the end of the processing tray 521 on the downstream side in the alignment direction (upper right side in FIG. 3, lower right side in FIG. 4). The reference plate 73 is substantially U-shaped in a cross section perpendicular to the sheet width direction with the upstream side in the alignment direction (upper left side in FIG. 4) open. The reference plate 73 abuts against the edge of a sheet being carried into the processing tray 521 and aligns the sheet in the carry-in direction.

[0044] [4. Configuration of the first sheet transport path from the sheet entrance to the first sheet discharge section] 5 is a side cross-sectional view showing the configuration of the first sheet transport path 3 from the sheet entrance 2 to the first sheet discharge section 4 of the sheet post-processing device 1. The operation of the sheet S carried in from the sheet entrance 2 through the punching section 91 and the sheet binding unit 92 until it is discharged from the first sheet discharge section 4 will be described with reference to FIG.

[0045] 5, a sheet detection sensor 53 is disposed near the sheet entrance 2. The sheet detection sensor 53 detects the timing when the sheet S passes through the sheet entrance 2. As the sheet detection sensor 53, for example, a PI (photointerrupter) sensor having a detection unit made up of a light emitting unit and a light receiving unit is used.

[0046] An intermediate transport roller pair is disposed above the processing tray 521. The intermediate transport roller pair is composed of an upper transport roller a and a lower transport roller b. An alignment member 55 is provided below the intermediate transport roller pair .

[0047] 6 is a perspective view of the intermediate transport roller pair 54 and the alignment member 55. The intermediate transport roller pair 54 is arranged at a plurality of locations (two locations in this embodiment) along the sheet width direction. A drive input gear 542 is fixed to a rotation shaft 541 of the upper transport roller 54a. The upper transport roller 54a is rotationally driven by inputting a rotational driving force of a roller drive motor M2 (see FIG. 5) to the drive input gear 542. Then, the lower transport roller 64b, which is pressed against the upper transport roller 54a, rotates following the upper transport roller 54a.

[0048] The alignment member 55 assists in aligning the sheet S by moving (switching back) the sheet S carried onto the processing tray 521 (see FIG. 5) in an alignment direction approaching the reference plate 73. The alignment member 55 has a shaft 551 and an alignment paddle 552.

[0049] The shaft 551 is disposed parallel to the rotation axis 541 of the upper transport roller 54a. The alignment paddle 552 is fixed to a plurality of locations (two locations in this embodiment) on the shaft 551. The alignment paddle 552 is a rubber sheet, and protrudes in the tangential direction from positions in the same phase in the circumferential direction of the shaft 551.

[0050] A drive transmission gear 553 is fixed to the shaft 551 at a position where it meshes with the drive input gear 542. As a result, the rotational drive 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 rotates. More specifically, the alignment paddle 552 rotates in a direction (counterclockwise in FIG. 5) in which the sheet S is sent in the alignment direction by the roller drive motor M2. The alignment paddle 552 rotates in contact with the upper surface of the sheet S carried into the processing tray 521, thereby moving the sheet S in the alignment direction and abutting the edge of the sheet S against the reference plate 73 for alignment.

[0051] A stepping motor capable of precisely controlling the direction and amount of rotation (angle of rotation) through pulse control is used as the roller drive motor M2.

[0052] In addition, a home position detection unit 58 is provided to detect the reference position (home position) of the alignment member 55 (alignment paddle 552). The home position detection unit 58 has a sensor unit 56 and a detection plate 57.

[0053] Fig. 7 is an enlarged view of the vicinity of the home position detection unit 58 in Fig. 6. The sensor unit 56 is a transmission type PI (photointerrupter) sensor, and has a detection unit 56a in which a light emitting unit and a light receiving unit are arranged opposite each other. The detection plate 57 is fixed to the end of the shaft 551. The sensor unit 56 is arranged so that the detection unit 56a sandwiches the outer periphery of the detection plate 57.

[0054] 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 becomes a 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 transmitted to the post-processing control unit 10 as a detection signal. The post-processing control unit 10 detects that the phase (rotational position) of the alignment paddle 552 is at the home position based on the output of the home position detection unit 58.

[0055] 8 is a side cross-sectional view showing the structure around the alignment member 55, and shows a state in which the alignment paddle 552 is in the home position. In this embodiment, the home position of the alignment paddle 552 is a position where the alignment paddle 552 is retracted from the first sheet transport path 3 as shown in FIG. 8, more specifically, a position where the alignment paddle 552 protrudes substantially parallel to the first sheet transport path 3 toward the upstream side (the right side in FIG. 8) with respect to the sheet transport direction of the first sheet transport path 3.

[0056] Note that the home position detection unit 58 is not limited to the configuration having the sensor unit 56 and the detection plate 57 as shown in FIG. 7, and may have another configuration as long as it can detect the phase (rotational position) of the alignment paddle 552.

[0057] [5. Matching paddle phase adjustment control] Next, a description will be given of the phase adjustment control of the alignment paddle 552. As shown in Fig. 6, in the configuration of this embodiment, the alignment member 55 is disposed close to and below the intermediate transport roller pair 54. Therefore, the rotation path of the alignment paddle 552 overlaps with the first sheet transport path 3 (the transport path of the sheet S passing through the intermediate transport roller pair 54).

[0058] 9 is a diagram showing a state in which the alignment paddle 552 comes into contact with the rear end of the sheet S. As shown in FIG. 9, depending on the phase (rotational position) of the alignment paddle 552, the alignment paddle 552 may come into contact with the rear end of the sheet S being transported through the first sheet transport path 3, and push the sheet S out in the transport direction. As a result, when the sheet S is pulled onto the processing tray 521, it may not be pulled to a desired position, making it difficult to stably transport and align the sheet S.

[0059] Therefore, in this embodiment, when there is a high possibility that the sheet S being conveyed through the first sheet conveying path 3 will come into contact with the alignment paddle 552, the phase of the alignment paddle 552 is shifted to avoid contact with the sheet S.

[0060] Specifically, the post-processing control unit 10 calculates a section (hereinafter referred to as an expected contact section) in which the rear end of the sheet S may come into contact with the alignment paddle 552. Then, when the timing (hereinafter referred to as an interference timing) at which the alignment paddle 552 interferes with (overlaps) 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 transmits a control signal to the roller drive motor M2 to temporarily decelerate (or accelerate) the rotation speed of the alignment member 55 (shaft 551).

[0061] Fig. 10 is a diagram showing a state in which the phase of the alignment paddle 552 is shifted. By temporarily decelerating (or accelerating) the rotational speed of the alignment member 55, as shown in Fig. 10, the phase of the alignment paddle 552 becomes a position (solid line position) shifted by a predetermined angle from the position (dashed line position) before deceleration (or acceleration). In this way, when the interference timing of the alignment paddle 552 overlaps with the expected contact zone, it is possible to avoid contact between the alignment paddle 552 and the rear end of the sheet S by shifting the phase of the alignment paddle 552 so that the interference timing is outside the expected contact zone.

[0062] The interference timing of the alignment paddle 552 can be calculated from the output of the home position detection unit 58. Specifically, since the timing when the alignment paddle 552 reaches the home position (see FIG. 8) can be detected from the output of the home position detection unit 58, the interference timing is calculated from the drive pulse of the roller drive motor M2 from the home position to the position where it interferes with the first sheet transport path 3 (see FIG. 9).

[0063] The assumed contact section can be calculated by an arithmetic expression stored in advance in the storage unit of the post-processing control unit 10, based on the conveying speed of the sheet S in the image forming apparatus 200 and the sheet post-processing device 1, the size of the sheet S in the conveying direction, and the conveying distance. The assumed contact section is approximately several mm to tens of mm when expressed in distance [mm], depending on conditions such as the conveying speed of the image forming apparatus 200 and the sheet post-processing device 1. The assumed contact section can also be expressed in time [sec].

[0064] Furthermore, when punching the sheet S in the punching section 91, or when performing a resist correction (skew correction) in which the leading edge of the sheet S is struck against the upstream transport roller pair 31 to bend the sheet S, it is necessary to take into consideration the time required for the punching process, and the time required for forming and eliminating the bend. That is, when a predetermined post-processing is performed upstream of the alignment paddle 552, it is necessary to calculate the expected contact section taking into consideration the time required for the post-processing (post-processing time).

[0065] It should be noted that the length of the estimated contact section can be changed by changing the parameters of the calculation formula when designing the sheet post-processing device 1. For example, if it is desired to more reliably prevent contact between the alignment paddle 522 and the rear end of the sheet S, the parameters of the calculation formula are changed so that the calculated estimated contact section is extended. On the other hand, if it is desired to prevent the phase adjustment control of the alignment paddle 522 from being frequently performed, the parameters of the calculation formula are changed so that the calculated estimated contact section is shortened.

[0066] Fig. 11 is a flowchart showing an example of phase adjustment control of the alignment paddle 552 executed in the sheet post-processing device 1 of this embodiment. The phase adjustment procedure of the alignment paddle 552 will be described along the steps of Fig. 11, with reference to Figs. 1 to 10 as necessary. In the following description, information regarding the size and conveying speed of the sheet S and post-processing to be performed on the sheet S is simply referred to as sheet output information.

[0067] When a binding process command for sheets S is input from the main body control unit of the image forming apparatus 200, output information for sheets S is input together with the binding process command (step S1). Of the output information for sheets S, information regarding the size of sheets S is input from the operation panel 202 of the image forming apparatus 200. For example, the manufacturer, product name, model number, etc. of sheets S may be associated with information regarding the corresponding type of sheets S and stored in advance in the main body control unit 203. This allows the main body control unit 203 to recognize information regarding the size of sheets S to be used simply by the user selecting the manufacturer, product name, model number, etc. of sheets S from the operation panel 202.

[0068] Information regarding the conveying speed of sheet S in image forming apparatus 200 is transmitted from main body control unit 203 based on a printing mode (photo printing mode, text printing mode, double-sided printing mode, etc.) input from a host device such as a personal computer or operation panel 202.

[0069] Information regarding post-processing for the sheets S is transmitted from the main body control unit 203 based on the contents of post-processing (binding, punching, registration correction, etc.) input from a host device such as a personal computer or an operation panel 202.

[0070] The post-processing control unit 10 calculates an assumed contact section of the alignment paddle 522 with respect to the sheet S based on the input output information of the sheet S (step S2), and then starts conveying the sheet S (step S3).

[0071] Next, the post-processing control unit 10 detects the home position of the alignment paddle 522 (step S4). Specifically, when the sheet detection sensor 53 detects the introduction of the sheet S, the post-processing control unit 10 transmits 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. Then, based on the output of the home position detection unit 58, the post-processing control unit 10 detects the timing when the alignment paddle 522 reaches the home position.

[0072] Next, the post-processing control unit 10 determines whether or not it is necessary to correct the phase (rotational position) of the alignment paddle 552 (step S5). Specifically, based on the assumed contact section calculated in step S2 and the home position of the alignment paddle 552 detected in step S4, it determines whether or not the interference timing of the alignment paddle 552 overlaps with the assumed contact section when the intermediate conveying roller pair 54 and the alignment member 55 are rotated at a reference speed.

[0073] When the interference timing of the alignment paddle 552 and the expected contact section overlap, it is determined that it is necessary to correct the phase of the alignment paddle 552. The determination of whether or not it is necessary to correct the phase of the alignment paddle 552 is performed in the section (R1 in FIG. 5) from when the leading edge of the sheet S is detected by the sheet detection sensor 53 until the sheet S reaches the upstream transport roller pair 31.

[0074] If 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 transmits a control signal to the roller drive motor M2 to reduce the rotation speed of the roller drive motor M2, thereby decelerating the alignment member 55 from the reference speed (step S6). After that, the alignment member 55 is returned to the reference speed again (step S7).

[0075] In this embodiment, the roller drive motor M2 is used as a drive source shared by the intermediate transport 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 transport roller pair 54 is decelerated. Therefore, the operation of decelerating the alignment member 55 from the reference speed and returning it to the reference speed again is performed in the section (R2 in FIG. 5) from when the leading edge of the sheet S passes through the upstream transport roller pair 31 until it reaches the intermediate transport roller pair 54.

[0076] On the other hand, if it is determined that correction of the phase of the alignment paddle 552 is not necessary (No in step S5), the rotation speed of the roller drive motor M2 is not changed and the alignment member 55 is continuously rotated at the reference speed (step S8).

[0077] The sheet S that has passed through the intermediate transport roller pair 54 has its rear end struck downward by a striking member (not shown) and falls onto the processing tray 521. The sheet S that has fallen onto the processing tray 521 is pulled along the processing tray 521 in the alignment direction (the direction of the arrow B in FIGS. 3 and 4) by the rotating alignment paddle 522, aligned in the sheet width direction by the width regulating member 523 (see FIG. 3), aligned in the carry-in direction by the reference plate 73 (see FIG. 3), and stacked.

[0078] Next, the post-processing control unit 10 determines whether or not a predetermined number of sheets S have been carried into the processing tray 521 (step S9). If the predetermined number of sheets S have not been carried into the processing tray 521 (No in step S8), the process returns to step S2 and repeats the above procedure (steps S2 to S8).

[0079] When the predetermined number of sheets S have been conveyed (Yes in step S9), the post-processing control unit 10 sends a control signal to the staple unit drive motor M1 (see FIG. 3) to move the staple unit 71 to a predetermined staple position. After the staple unit 71 has moved to the predetermined staple position, the post-processing control unit 10 sends a control signal to the staple unit 71 to perform stapling on the multiple sheets S aligned by the reference plate 73 (step S10), and ends the phase adjustment control of the alignment paddle 552.

[0080] 11, when the expected contact section calculated based on the output information of the sheet S overlaps with the interference timing of the alignment paddle 552, the phase of the alignment paddle 522 is appropriately corrected. This makes it possible to suppress the alignment paddle 522 from pushing out the sheet S, and to stably transport the sheet S and align it on the processing tray 521.

[0081] In addition, since there is no need to stop the rotation of the alignment member 55, the influence on the alignment of the sheets S stacked on the processing tray 521 can be reduced.

[0082] Furthermore, by driving the alignment member 55 and the intermediate transport roller pair 54 with the same drive source (roller drive motor M2), it is possible to reduce manufacturing costs and make the device more compact.

[0083] Furthermore, before the sheet S reaches the intermediate transport roller pair 54, the alignment member 55 is decelerated (or accelerated) to correct the phase of the alignment paddle 552, and the operation of returning the alignment member 55 to the reference speed again is completed. This makes it possible to prevent the influence of the change in rotation speed of the intermediate transport roller pair 54 on the transport of the sheet S when the roller drive motor M2 is used in common as a drive source for both the intermediate transport roller pair 54 and the alignment member 55.

[0084] Furthermore, by including the contents of post-processing such as punching by the punching unit 91 and registration correction in the output information of the sheet S, it is possible to calculate an appropriate contact expected section taking into account the contents of post-processing executed upstream of the sheet binding unit 92. Therefore, contact between the rear end of the sheet S and the alignment paddle 522 can be more reliably avoided.

[0085] Although the embodiment of the present invention has been described above, the scope of the present invention is not limited thereto, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, the alignment member 55 is provided below the intermediate transport roller pair 54, but the intermediate transport roller pair 54 and the alignment member 55 may be integrally configured by attaching an alignment paddle 552 to the rotation shaft of the lower transport roller 54b of the intermediate transport roller pair 54.

[0086] Furthermore, in the above embodiment, the alignment paddle 552 is fixed to only one location in the circumferential direction of the shaft 551, but the alignment paddle 552 may be fixed to a plurality of locations in the circumferential direction of the shaft 551 at equal intervals.

[0087] In the above embodiment, the roller drive motor M2 is used as a drive source shared by the intermediate transport roller pair 54 and the alignment member 55, but the present invention is also applicable to a configuration in which the intermediate transport roller pair 54 and the alignment member 55 are driven by separate drive sources. In that case, the operation of decelerating the alignment member 55 from the reference speed and returning it to the reference speed again may be performed after the leading edge of the sheet S reaches the intermediate transport roller pair 54.

[0088] In addition, in the above embodiment, an example is shown in which the sheets S stacked on the processing tray 521 are bound by the sheet binding unit 92, but the present invention is not limited to this, and the configuration may also be such that the sheets S stacked on the processing tray 521 are subjected to a shift discharge process or a folding process.

[0089] In addition, in the above embodiment, the output information regarding 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 acquired automatically. For example, a media sensor may be disposed at any position on the sheet transport path from the image forming apparatus 200 to the sheet post-processing apparatus 1, and the size of the sheet S conveyed from the image forming apparatus 200 to the sheet post-processing apparatus 1 may be detected by the media sensor.

[0090] Furthermore, in the above embodiment, an inkjet recording apparatus is exemplified as the image forming apparatus 200, but an electrophotographic printer or copying machine can also be used as the image forming apparatus 200. [Industrial Applicability]

[0091] The present invention can be used in a sheet post-processing device that performs a predetermined post-processing on a plurality of sheets. [Explanation of symbols]

[0092] 1 Sheet post-processing device 2 Sheet entrance 3 First sheet transport path 4 First sheet ejection section 5 Second sheet transport path 6 Second sheet ejection section 10 Post-processing control section (control section) 31 upstream transport roller pair (second transport member) 42 First discharge roller pair 521 Processing Tray 53 Sheet detection sensor (sheet detection section) 54 Intermediate conveying roller pair (first conveying member) 55 Alignment member 551 Shaft 552 Matching Paddle 56 Sensor section 57 Detection plate 58 Home position detector 71 Stapling section (first processing section) 73 Reference plate 91 Perforation section (second processing section) 92 Sheet binding unit 200 Image forming device 202 Operation Panel 203 Main unit control section M2 Roller drive motor (drive unit) S Seat

Claims

1. A first conveying member that conveys a sheet; a processing tray on which a plurality of the sheets are stacked and which are conveyed by the first conveying member along a predetermined conveying direction; a first processing section that performs a predetermined post-processing on the sheets stacked on the processing tray; a reference plate that abuts against an edge of the sheet conveyed onto the processing tray on a downstream side in an alignment direction, which is the opposite direction to the conveying direction, to align the sheet in the conveying direction; a shaft disposed above the processing tray and connected to a drive unit to rotate; one or more alignment paddles that protrude radially from the shaft and contact the sheet conveyed onto the processing tray; an alignment member that rotates in the alignment direction on a surface facing the processing tray to move the sheet carried onto the processing tray in the alignment direction to assist alignment of the sheet; a home position detector for detecting that the alignment paddle is in a reference position; A control unit that controls the drive unit; In a sheet post-processing device comprising: The control unit is calculating an assumed contact section in which the rear end of the sheet conveyed along the conveying direction may come into contact with the alignment paddle based on the output information of the sheet; calculating an interference timing at which the alignment paddle interferes with a carry-in path of the sheet based on a detection result of the home position detection unit; A sheet post-processing device characterized in that, when the interference timing is within the expected contact zone, the rotational speed of the alignment member is temporarily changed from a reference speed to change the phase of the alignment paddle so that the interference timing is outside the expected contact zone.

2. a single driving unit configured to rotate the alignment member and the first conveying member; 2 . The sheet post-processing device according to claim 1 , wherein the control unit temporarily changes the rotation speed of the alignment member from the reference speed, and then returns the alignment member to the reference speed again before the sheet reaches the first conveying member.

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

4. one or more second processing units that perform a predetermined post-processing on the sheet are provided upstream of the processing tray in a conveying direction of the sheet, The sheet post-processing device according to claim 1 , wherein the output information of the sheet includes a time required for post-processing in the second processing section.

5. a sheet detection unit that is disposed upstream of the first conveying member in a conveying direction of the sheet and detects the passage of the sheet; The sheet post-processing device according to claim 1 , wherein the control unit calculates the interference timing after the sheet detection unit detects the passage of the sheet.

6. a second conveying member disposed downstream of the sheet detection unit and upstream of the first conveying member with respect to the conveying direction, the second conveying member conveying the sheet in the conveying direction; The sheet post-processing device according to claim 5, characterized in that the control unit determines whether the interference timing is within the expected contact zone in the zone until the leading edge of the sheet reaches the second conveying member after the leading edge of the sheet is detected by the sheet detection unit.

7. 7. The sheet post-processing device according to claim 6, wherein the control unit changes the rotation speed of the alignment member from the reference speed after the leading edge of the sheet has passed the second conveying member, and returns the alignment member to the reference speed again before the sheet reaches the first conveying member.

8. The control unit calculates the contact assumed section using a preset calculation formula, The sheet post-processing device according to claim 1 , wherein the calculated length of the estimated contact section is adjustable by changing a parameter of the calculation formula.

9. an image forming apparatus for forming an image on a sheet; 9. A sheet post-processing device according to claim 1, which performs a predetermined post-processing on the sheet on which an image is formed by the image forming device; An image forming system comprising:

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

Images