JP2005132610A - Sheet handling device and image forming device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet handling device capable of increasing the loading property of sheets by a simple structure and an image forming device having the sheet handling device. <P>SOLUTION: The displacement of a stacked sheet bundle SB can be prevented by pressing the sheet bundle SB stacked on a second sheet stacking means 421 by a sheet pressing means 422, and a sheet bundle SA can be discharged without being obstructed by the sheet pressing means 422 by moving the sheet pressing means 422 to a retracted position in conjunction with the movement of a sheet bundle discharge means 413 in the sheet discharge direction. Also, a sheet bundle rear end abutting member 418 is projected when the sheet bundle discharge means 413 is moved to a sheet bundle discharge position to abut the rear end of the sheet bundle SA on the sheet bundle rear end abutting member 418 when the sheet bundle discharge means 413 is returned. Thus, a sheet bundle drop position can be kept unchanged. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus including the sheet processing apparatus, and more particularly to a configuration for preventing a positional deviation of a sheet bundle that is discharged after being processed.

  2. Description of the Related Art Conventionally, in image forming apparatuses such as copying machines, printers, facsimiles, and composite devices of these, a sheet processing apparatus that performs processing such as binding processing on sheets discharged from the image forming apparatus main body is provided on the image forming apparatus main body. There is something to be provided.

  As such a sheet processing apparatus, a sheet stacking operation for transporting a sheet discharged from the image forming apparatus main body to a sheet processing unit, and stacking and aligning the discharged sheet in the sheet processing unit, and a sheet In some cases, processing such as stapling is performed.

  Here, the conventional sheet processing apparatus that performs such processing is configured to discharge and stack the sheets on a predetermined stacking tray after performing the processing. However, when a large number of sheets are stacked on the stacking tray, there is a problem in that the sheet to be ejected pushes out the sheet already stacked on the stacking tray, causing a stacking deviation on the stacking tray. there were.

  Therefore, in order to solve the problem of such a drop in stackability, for example, as shown in FIG. 15, a sensor 601 for detecting the position of the discharged sheet is provided upstream of the discharge roller 600, and on the stacking tray 602. An alignment arm 603 for pressing the sheet is provided, and a time during which the conveying force of the paper discharge roller 600 is not applied to the sheet is detected based on the detection result from the sensor 601, and the sheet on the stacking tray is moved by the alignment arm 603 until this time. There is something to be pressed.

  By pressing the sheets on the stacking tray by the aligning arm 603 in this way, even when a newly discharged sheet comes into contact with the sheet on the stacking tray, the pressing force by the aligning arm 603 has already placed the sheet on the stacking tray. It is possible to prevent the misalignment of the stacked sheets on the tray. After that, when it is time to prevent the conveying force from being applied to the sheet, the discharge arm can be stacked on the stacking tray by retracting the alignment arm 603 using power such as a solenoid (see Patent Document 1). .

JP 2000-272808 A (FIG. 1)

  However, such a conventional sheet processing apparatus and an image forming apparatus including the same require a sensor 601 for detecting the discharge timing of the discharged sheet and a power for retracting the alignment arm 603. Therefore, there is a problem that the configuration becomes complicated and the manufacturing cost increases. Further, since the alignment arm 603 is retracted by the control by the CPU, there is a problem that the control becomes complicated.

  Accordingly, the present invention has been made in view of such a current situation, and an object thereof is to provide a sheet processing apparatus capable of improving the stackability of sheets with a simple configuration and an image forming apparatus including the sheet processing apparatus. It is what.

  The present invention is provided with a first sheet stacking unit for stacking sheets to be processed and a downstream of the first sheet stacking unit in the sheet conveying direction, and after being processed on the first sheet stacking unit, the sheet is discharged. In the sheet processing apparatus including the second sheet stacking unit that stacks the sheet bundle, after the processing of the sheet bundle is finished, the sheet is moved in the direction of the second sheet stacking unit, and the processed first A sheet bundle discharging means for discharging the sheet bundle on the sheet stacking means to the second sheet stacking means, a sheet bundle pressing means for pressing the sheets stacked on the second sheet stacking means from above, and the sheet A pressing position for pressing the sheet from above, and a pressing means moving means for selectively moving the bundle pressing means to a retracted position below the first sheet stacking means. In conjunction with the movement of the sheet bundle discharging means in the sheet bundle discharging direction, the sheet bundle pressing means is moved to the retracted position, and after the sheet bundle discharging operation of the sheet bundle discharging means is completed, the sheet bundle pressing means is pressed. It is characterized by being moved to a position.

  In the invention, it is preferable that the pressing means moving means is a cam that moves as the sheet bundle discharging means moves.

  In the invention, it is preferable that the sheet bundle discharge unit includes a sheet bundle holding unit that holds the processed sheet bundle, and the sheet bundle holding unit moves to a position where the sheet bundle discharge unit discharges the sheet bundle. The holding of the sheet bundle by the means is released.

  According to the present invention, a sheet bundle rear end abutting member provided at a second sheet stacking means side end portion of the first sheet stacking means so as to protrude and retract, and the sheet bundle rear end abutting member are provided in the first sheet stacking means. Abutting member moving means that projects from the end of the sheet stacking means on the second sheet stacking means side, and the abutting member moving means moves to a position where the sheet bundle discharging means discharges the sheet bundle. Then, the sheet bundle trailing edge abutting member is protruded upstream of the sheet bundle discharging means, and the sheet bundle released by the sheet bundle holding means is released when the sheet bundle discharging means returns to the position before the movement. It is characterized by striking the rear end of the head.

  In the invention, it is preferable that the abutting member moving means is a cam that moves in accordance with the movement of the sheet bundle discharging means.

  According to the present invention, in the image forming apparatus, the image forming unit includes an image forming unit that forms an image on the sheet, and the sheet processing device according to any one of the above that processes the sheet on which the image is formed by the image forming unit. It is characterized by.

  According to the present invention, in the image forming apparatus, an image forming unit that forms an image on a sheet, a first sheet stacking unit that stacks sheets processed from the image forming unit, and a sheet of the first sheet stacking unit A second sheet stacking unit that is provided downstream in the conveying direction and that is processed on the first sheet stacking unit and then stacks the discharged sheet bundle; and after the processing of the sheet bundle is completed, the second sheet stacking unit A sheet bundle discharging unit that moves in the direction of the sheet stacking unit and discharges the processed sheet bundle on the first sheet stacking unit to the second sheet stacking unit; A sheet bundle pressing means for pressing the sheet from above, a pressing position for selectively pressing the sheet bundle pressing means from above, and a pressing mechanism for selectively moving to a retreat position below the first sheet stacking means. The sheet bundle pressing means is moved to the retracted position in conjunction with the movement of the sheet bundle discharging means in the sheet bundle discharging direction, and after the sheet bundle discharging operation of the sheet bundle discharging means is completed, And a means for moving the sheet bundle pressing means to the pressing position.

  According to the present invention, the sheet bundle stacked on the second sheet stacking unit is pressed from above by the sheet pressing unit, so that the deviation of the already stacked sheet bundle can be prevented and the processed sheet bundle can be By moving the sheet pressing means to the retracted position in conjunction with the movement of the sheet bundle discharging means to be discharged to the second sheet stacking means in the sheet discharging direction, the second sheet bundle is not obstructed by the sheet pressing means. The sheet can be discharged to the sheet stacking means. Thereby, the stackability of sheets can be improved with a simple configuration.

  Further, the sheet bundle trailing edge abutting member is protruded when the sheet bundle discharging means moves to the sheet discharging position, and when the sheet bundle discharging means returns to the position before the movement, the sheet bundle trailing edge is pushed to the trailing edge of the sheet bundle. By abutting the contact member, the sheet bundle falling position can be made constant, and the sheet bundle can be aligned on the second sheet stacking means.

  Further, by moving the sheet pressing unit and the sheet bundle rear end abutting member in conjunction with the movement of the sheet bundle discharging unit, a simple configuration can be achieved.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a configuration of an image forming apparatus provided with a sheet treatment apparatus according to an embodiment of the present invention, in which A is an image forming apparatus, 500 is an image forming apparatus main body, and 300 is an image. An automatic document feeder (ADF) 400 provided on the upper surface of the forming apparatus main body 500 is a sheet processing apparatus that processes sheets discharged from the image forming apparatus A.

  In the figure, reference numeral 120 denotes a reader unit (image input device) that converts a document into image data, and 200 includes a plurality of types of sheet cassettes 204 and 205, and the image data is converted into a visible image on the sheet by a print command. It is a printer unit which is an image forming unit to output.

  In the image forming apparatus A configured as described above, when an original image is read to form an image, first, the originals stacked on the automatic original feeder (ADF) 300 are sequentially placed on the platen glass one by one. It is carried on the surface 102.

  Next, when the document is conveyed to a predetermined position on the glass surface 102 in this way, the lamp 103 of the reader unit 120 is turned on, and the scanner unit 104 moves to irradiate the document. Then, the reflected light from the original is input to the CCD image sensor unit 109 through the mirrors 105, 106, 107 and the lens 108, and electrical processing such as photoelectric conversion is performed in the CCD image sensor unit 109, and normal digital processing is performed. Is given.

  Next, the image signal subjected to the electrical processing in this manner is converted into a modulated optical signal by the exposure control unit 201 of the printer unit 200, and irradiates the photosensitive drum 202. Then, a latent image is formed on the photosensitive drum 202 by the irradiation light, and the latent image is developed by the developing device 203. As a result, a toner image is formed on the photosensitive drum 202.

  Next, the sheet S is conveyed from the sheet cassettes 204 and 205 in synchronization with the leading edge of the toner image, and the toner image is transferred to the sheet S by the transfer unit 206. Thereafter, the toner image transferred to the sheet S is fixed by the fixing unit 207. After the toner image is fixed in this way, the sheet S is discharged from the paper discharge unit 208 to the outside of the apparatus.

  Then, the sheet S output from the paper discharge unit 208 is conveyed to the sheet processing apparatus 400, and processing such as sorting and binding is performed in accordance with an operation mode designated in advance by the sheet processing apparatus 400.

  When outputting sequentially read images on both sides of one sheet S, first, the direction switching member 209 is once switched in the solid line direction in the drawing for the sheet S on which the toner image is fixed on one side by the fixing unit 207. Then, the direction switching member 217 is switched to the solid line direction, and the direction switching member 213 is switched to the solid line direction, so that the sheet is conveyed to the reverse path 212 via the path 218.

  Next, after the trailing edge of the sheet passes through the direction switching member 213, the direction switching member 213 is switched to the broken line direction, and the rotation direction of the roller 211 is reversed to guide the sheet to the path 210, and then to the transfer unit 206. The sheet is conveyed to form an image on the back surface of the sheet S.

  On the other hand, the sheet processing apparatus 400 has a stapling function that is a binding operation by a stapling unit in addition to a sorting operation for sorting sheets, and is sequentially discharged from the image forming apparatus main body 500 as shown in FIG. A processing tray 410 for processing the sheet S and a stack tray 421 for finally stacking a sheet bundle processed on the processing tray 410 are provided, and a sheet bundle corresponding to the number of documents is displayed on the processing tray. The sheet is formed and discharged to the stack tray 421 for each sheet bundle.

  In the figure, reference numeral 401 denotes a sheet receiving unit that receives the sheet S discharged from the image forming apparatus main body 500. The sheet S received by the sheet receiving unit 401 is detected by the entrance sensor 403, and then the conveyance roller. 405 and an offset roller 407, and thereafter discharged onto a processing tray 410 as a first sheet stacking unit as shown in FIG. The sheets S stacked on the processing tray 410 in this way are detected by a sheet bundle discharge sensor 415 shown in FIG.

  Here, the offset roller 407 is held up and down by an offset roller arm 406 that can move up and down about a shaft 406 a shown in FIGS. 4 and 5, and when the sheet S is discharged to the processing tray 410. The sheet S is moved upward via the offset roller arm 406, whereby the sheet S is discharged onto the processing tray 410 without being obstructed by the offset roller 407.

  The offset roller arm 406 can be moved up and down by a pickup solenoid 433 with a shaft 406a as a fulcrum. That is, the offset roller 407 moves up and down when the pickup solenoid 433 is turned on / off.

  Further, as shown in FIG. 5, the offset roller 407 is driven via belts 431a and 431b by a conveyance motor 431 that drives the conveyance roller 405. When the conveyance motor 431 rotates, the conveyance motor 431 is driven. Rotate in the transport direction or in the opposite direction of the transport direction (hereinafter referred to as reverse rotation) by an amount corresponding to the amount of rotation.

  In the present embodiment, when the sheet bundle discharge sensor 415 detects a sheet, the pickup solenoid 433 is turned off, whereby the offset roller 407 is lowered by its own weight and landed on the sheet. Thereafter, the sheet rotates in the sheet conveying direction for a predetermined time, and reverses when the predetermined time elapses.

  By reversing in this way, the trailing edge of the sheet is brought into contact with the sheet trailing edge stopper 411 provided at the upstream end of the processing tray 410 in the conveying direction so as to align the sheet S in the conveying direction. ing.

  In FIG. 4, reference numeral 416 denotes a positioning wall serving as an alignment position reference at the end of the sheet in a direction orthogonal to the sheet conveyance direction (hereinafter referred to as the width direction), and 420 is disposed near the positioning wall of the processing tray 410. This is a stapler unit that performs a stapling process on a sheet bundle formed on the processing tray 410. The offset roller 407 is moved in the width direction via the rack and pinion by driving the offset motor 432, and close to the positioning wall 416. Can be done.

  When the offset roller 407 approaches the positioning wall 416 in this way, the sheet that is abutted against the sheet trailing edge stopper 411 and aligned in the conveyance direction moves to the positioning wall 416 by the frictional force of the offset roller 407. Thus, positioning in the width direction is performed. After the sheet S hits the positioning wall 416, the offset roller 407 moves and stops while sliding on the sheet.

  By providing such an offset roller 407, the sheet discharged onto the processing tray 410 is conveyed to the stack tray side by the offset roller 407 rotating in the sheet conveying direction as shown in FIG. 6B, the sheet is returned to the sheet trailing edge stopper 411 by the reverse rotation of the offset roller 407, and then the trailing edge is brought into contact with the trailing edge stopper 411 for alignment.

  In FIG. 6 and FIGS. 7 and 8 to be described later, unlike FIG. 4 described above, the offset roller 407 is described as having a configuration arranged inside the offset roller arm 406. This difference in configuration is merely a difference in design, and there is no difference in function and operation from the configuration shown in FIG.

  Thereafter, as shown in FIG. 6C, the offset roller 407 is moved to the positioning wall side along the shaft 406a while being grounded to the sheet S, so that the end in the width direction of the sheet S is positioned. The sheet S is pressed against the wall 416 and the sheet S is aligned in the width direction.

  On the other hand, in FIG. 5, reference numeral 412 denotes a sheet clamp member that is a sheet bundle holding unit that presses the rear end portion of the aligned sheet S from above by a biasing force by a biasing unit (not shown). Then, as shown in FIG. 7A, after the offset roller 407 is lifted by the pickup solenoid 433, the aligned sheet S is moved by the sheet clamp member 412 as shown in FIG. 7B. It can be pressed from above. As a result, the sheet S previously discharged to the processing tray 410 can be held at a predetermined position without being affected by the subsequent feeding by the sequentially fed sheets S. .

  The sheet clamp member 412 rotates upward as shown in FIG. 8A so that the sheet S can be received when the offset roller 407 is reversely rotated, and is offset to align the ends. When the sheet S moves in the width direction together with the roller 407, the sheet S is rotated upward as shown in FIG.

  In FIG. 5, reference numeral 413 denotes a sheet bundle discharge member which is a sheet bundle discharge unit for discharging the processed sheet bundle to the stack tray 421. The sheet bundle discharge member 413 rotatably holds the sheet clamp member 412. At the same time, the aligned sheet bundle, or the aligned sheet bundle after being aligned, is held on the downstream side of the processing tray 410 as shown in FIG. It moves in the direction of the stack tray 421 which is the second sheet stacking means.

  Further, after this, when the leading end of the processing tray 410, which is the sheet discharge position indicated by the solid line in FIG. The paper is discharged to the tray 421.

  Here, as shown in FIG. 5, the sheet bundle discharge member 413 has a position at which the sheet is discharged to the stack tray 421 and a trailing end stopper when power is transmitted through the rack and pinion by the sheet bundle discharge motor 430. It can move back and forth to the home position near 411. The sheet bundle discharge member 413 is normally fixed at the home position by excitation of the sheet bundle discharge motor 430.

  In FIG. 5, reference numeral 434 denotes a clamp solenoid for rotating the sheet clamp member 412. This clamp solenoid 434 is used when the offset roller 407 stops rotating after conveying the sheet and when the offset roller 407 moves in the width direction. It is turned on when moving, and the sheet clamp member 412 is rotated upward via a lever 434a.

  In this embodiment, after the sheet S is moved in the width direction, the offset roller 407 is reversely rotated again to complete the alignment operation in order to correct the deviation in the sheet conveyance direction. High-precision matching is achieved. When the specified number of sheets have been aligned, the clamp solenoid 434 closes the sheet clamp member 412 to hold the sheet bundle.

  FIG. 10 is a block diagram showing the configuration of the control unit of the sheet processing apparatus 400 having such a configuration, and 100 is a CPU. Here, the CPU 100 has a ROM 110 therein, and controls each unit while reading a program stored in the ROM 110 and corresponding to the flowcharts of FIGS. 13 and 14 described later.

  Further, the CPU 100 has a built-in RAM 120 in which work data and input data are stored, and the CPU 100 performs control based on data stored in the RAM 120. Further, a sensor such as an inlet sensor 403 is connected to the input port of the CPU 100, and the CPU 100 reads out and executes a program corresponding to the flowcharts of FIGS. 13 and 14 stored in the ROM 110 based on the state of these sensors. Thus, a load such as a transport motor connected to the output port is controlled.

  In addition, the CPU 100 includes a serial interface unit (I / O) 130, which transmits and receives control data to and from the image forming apparatus main body 500 (control unit thereof), and also transmits an image via the serial interface unit (I / O) 130. Each unit is controlled based on control data sent from the forming apparatus main body 500 (control unit thereof).

  Since the image forming apparatus main body 500 knows the size of the sheet discharged from the sheet discharge unit 208, the control unit of the sheet processing apparatus 400 performs serial communication with the control unit of the image forming apparatus main body 500 to perform processing. The size of the sheet inserted on the tray 410 can be grasped.

  Therefore, each time the sheet S is discharged from the image forming apparatus main body 500, the control unit (CPU 100) of the sheet processing apparatus 400 grasps the size of the sheet S and controls the offset motor 432 so that the offset roller 407 in the width direction is controlled. The movement amount can be controlled to be a movement amount according to the sheet size. As a result, the offset roller 407 moves by an amount corresponding to the size of the sheet discharged onto the processing tray 410, and the side edge of the sheet S can be reliably pressed against the positioning wall 416.

  By the way, as shown in FIG. 11, a pressing arm 422 as a sheet bundle pressing unit is rotatably provided below the processing tray 410. Here, the pressing arm 422 is for pressing the sheet bundle SB discharged and stacked on the stack tray 421 from above, and by pressing the sheet S by the pressing arm 422 in this way, the sheet is discharged to the processing tray 410. At this time, the sheet bundle SB already stacked on the stack tray 421 is prevented from being pushed out by the leading end portion of the discharged sheet.

  Further, when the sheet bundle is discharged by the sheet bundle discharge member 413, the pressing arm 422 rotates upward and retracts below the processing tray 410 as shown in FIG. Yes. By retreating below the processing tray 410 in this way, the discharge of the sheet bundle SA onto the stack tray 421 is not hindered.

  As described above, the sheet bundle SB stacked on the stack tray 421 is pressed from above by the pressing arm 422, so that the deviation of the already stacked sheet bundle SB can be prevented and the sheet discharge direction of the sheet bundle discharge member 413 can be prevented. The sheet bundle SA can be discharged to the stack tray 421 without being obstructed by the pressing arm 422 by moving the pressing arm 422 to the retracted position in conjunction with the movement to. Thereby, the stackability of sheets can be improved with a simple configuration.

  Further, as shown in FIG. 11, a sheet bundle rear end abutting member 418 is provided at the discharge end portion (stack tray side end portion) of the processing tray 410 so as to appear and retract. Here, the sheet bundle rear end abutting member 418 protrudes from the processing tray 410 when the sheet bundle discharge member 413 reaches the sheet bundle discharge position shown in FIG.

  After the sheet bundle rear end abutting member 418 protrudes in this way, the sheet clamp member 412 is opened, and when the sheet bundle discharge member 413 moves in the direction returning to the home position, the sheet bundle discharge member 413 holds it until then. As shown in FIG. 12B, the rear end of the sheet bundle SA that has been made falls in contact with the sheet bundle rear end abutting member 418 protruding from the discharge end portion of the processing tray 410. Here, the sheet bundle SA is brought into contact with the sheet bundle rear end abutting member 418 and dropped so that the sheet bundle falling position can be made constant, and the sheet bundle SB on the stack tray can be moved. Can be aligned.

  In FIG. 11, reference numeral 417 denotes a rotating member that is rotated by the sheet bundle discharge motor 430, and the rotating member 417 is provided with a cam portion 417 a that is a pressing means moving unit that rotates the pressing arm 422. Yes.

  When the sheet bundle discharging member 413 is moved, the rotating member 417 is rotated, and the rotating member 417 is moved to the top dead center of the cam portion 417a as the sheet bundle discharging member 413 reaches the sheet bundle discharging position. , The pressing arm 422 is moved from the sheet pressing position above the stack tray 421 through the lever 423 provided integrally with the pressing arm 422 by the action of the cam portion 417a, as shown in FIG. Move to the retreat position below 410.

  Further, when the sheet bundle discharge member 413 discharges the processed sheet bundle SA and then returns to the home position, that is, after the sheet bundle SA is stacked on the stack tray 421, the rotation member 417 is rotated thereafter. Accordingly, as shown in FIG. 12C, the pressing arm 422 is moved from the retracted position below the processing tray 410 to the sheet pressing position above the stack tray 421 by the action of the cam portion 417a. The sheet bundle SA stacked on 421 is pressed from above.

  In the present embodiment, after the sheet bundle SA is discharged, the stack tray 421 is lowered by a predetermined distance by a stack tray lifting motor (see FIG. 10), whereby the pressing arm 422 is The sheet bundles SA and SB can be pressed at substantially the same height position.

  Further, in this embodiment, when the pressing arm 422 moves in accordance with the movement of the sheet bundle discharge member 413 as described above, the sheet bundle rear end abutting member 418 is also a turning member 417 that is an abutting member moving means. After the sheet bundle discharge member 413 reaches the sheet bundle discharge position shown in FIG. 12A, the sheet bundle discharge member 413 protrudes on the processing tray 410 by a cam portion (not shown) provided in FIG.

  The cam portion (not shown) is formed so that the sheet bundle rear end abutting member 418 protrudes for a predetermined time when the sheet bundle discharging member 413 returns to the home position. When the sheet bundle is moved to the discharge position and then returned to the home position, the sheet bundle SA released from being held (held) by the sheet clamp member 412 comes into contact with the sheet bundle rear end abutting member 418, and thereby the sheet bundle. SA always falls to the same position on the stack tray 421.

  In this way, by projecting the sheet bundle rear end abutting member 418 in conjunction with the movement of the sheet bundle discharging member 413, the sheet bundle falling position can be always fixed and the sheet bundle SB on the stack tray can be aligned. it can. Further, by moving not only the sheet bundle rear end abutting member 418 but also the pressing arm 422 as described above in conjunction with the movement of the sheet bundle discharge member 413, a simple configuration can be achieved.

  In FIG. 11, reference numeral 422 a denotes a spring that urges the pressing arm 422 in the direction of rotating upward via the lever 423, and when the pressing arm 422 is pressed by the cam portion 417 a of the rotating member 417, While rotating against the spring 422a in the direction of pressing the sheet on the stack tray 421, when the pressing by the cam portion 417a is released, the spring 422a moves to the retracted position.

  Reference numeral 418a denotes a spring that urges the sheet bundle rear end abutting member 418 in a direction to rotate upward, and normally a sheet bundle rear end abutting located at a retracted position below the processing tray 410 against the spring 418a. When the sheet bundle discharge member 413 returns to the home position, the member 418 protrudes on the processing tray 410 by the action of the cam portion (not shown) and the spring 418a.

  Next, the sheet processing operation of the sheet processing apparatus 400 of the present embodiment configured as described above will be described with reference to the flowcharts shown in FIGS.

  First, when an image forming operation by the image forming apparatus main body 500 is started, the CPU 100 (see FIG. 10) of the sheet processing apparatus 400 checks whether or not a sheet discharge signal is received from the image forming apparatus main body 500 (S100). ). If a sheet discharge signal is received (Y in S100), the pickup solenoid 433 is turned on (S110), and the offset roller 407 supported by the offset roller arm 406 is pulled up.

  Next, the transport motor 431 is turned on (S120), so that the transport roller 405 installed in the middle of the path can transport the sheet in the same direction as the paper discharge direction of the image forming apparatus main body 500. Here, the leading edge of the first sheet passes through the inlet sensor 403 and turns on the inlet sensor 403 (Y in S130). Thereafter, the sheet reaches the conveying roller 405 and power is transmitted from the conveying roller 405 to the sheet. Then, when the sheet is separated from the paper discharge unit 208 (see FIG. 1) of the image forming apparatus main body 500 (Y in S140), the delivery of the sheet is completed.

  Next, while the sheet is conveyed to the processing tray 410 by the conveying roller 405, the pickup solenoid 433 is turned off before the sheet is completely removed from the conveying roller 405 (S150), and the offset roller 407 is landed on the sheet by its own weight. Let Thereafter, as shown in FIG. 6A, the sheet S is conveyed to a predetermined position by the offset roller 407 (S160). When the sheet S is conveyed to a predetermined position (Y in S160), the rotation of the conveyance motor 431 is stopped (S170), and the conveyance of the sheet S is stopped.

  Next, when the rotation of the offset roller 407 stops, the clamp solenoid 434 is turned on (S180), and the sheet clamp member 412 installed in the vicinity of the rear end stopper 411 is opened as shown in FIG. 6B. . Thereafter, the conveyance motor 431 is rotated in the direction opposite to the conveyance direction, the sheet S is pulled back by the offset roller 407 (S190), and the trailing edge of the sheet is abutted against the trailing edge stopper 411.

  Note that the rotation amount of the offset roller 407 when the trailing edge of the sheet abuts against the trailing edge stopper 411 takes into account the skew of the sheet S that is generated when the sheet S is fed from the image forming apparatus main body 500, and conveys the sheet S. It is rotated so that it can be transported slightly more than the distance from the point of stopping and switching back to the rear end stopper 411.

  Next, the sheet size to be discharged is checked based on the size information from the image forming apparatus main body 500 (S200), and the offset movement amount according to the size of the discharged sheet S, that is, the sheet S discharged onto the processing tray 410 is checked. The movement distance in the width direction of the sheet S necessary for pressing the sheet to the positioning wall 416 is calculated (S210).

  Thereafter, the offset roller 407 is offset to the positioning wall 416 via the rack and pinion by the offset motor 432 as shown in FIG. 6C (S220). Here, when the offset roller 407 moves in this way, the sheet S in contact with the offset roller 407 moves together with the offset roller 407 in the direction of the positioning wall 416 by the frictional force of the offset roller 407. At this time, the sheet clamp member 412 is rotated upward as shown in FIG. 8B so as not to be a load of movement of the sheet S.

  Next, after the offset roller 407 abuts the sheet S against the positioning wall 416, the offset roller 407 slides slightly on the sheet S and stops. Thereafter, in order to correct the misalignment in the transport direction after the offset movement, an alignment operation is performed in which the offset roller 407 is reversed again and the sheet S is pulled back (S230). Alignment is complete.

  Next, when the alignment of the first sheet S is completed as described above, the pickup solenoid 433 is turned on (S240), and the offset roller 407 is lifted as shown in FIG. Turn off (S250). As a result, as shown in FIG. 7B, the sheet clamp member 412 is closed and the aligned sheet S is held and held. As a result, the first discharged sheet S is discharged next. It is possible to prevent the sheet from being carried by the used sheet.

  Next, as shown in FIG. 7B, the offset roller 407 is moved back to the home position via the rack and pinion by the offset motor 432 in a lifted state (S260).

  Thereafter, it is checked whether or not the sheet S accommodated on the processing tray 410 is the final sheet corresponding to the final page of the copy original (S270), and the final sheet is determined based on the information sent from the image forming apparatus main body 500. If it is determined that the sheet S is not the current sheet S (N in S270), the process returns to S100 and the next sheet discharge signal sent from the image forming apparatus main body 500 is received until the final sheet S is accommodated in the processing tray 410. Repeat the above flow.

  Thus, each time the sheet S is discharged from the image forming apparatus main body 500, the control unit (CPU) of the sheet processing apparatus 400 grasps the size of the sheet S and calculates an offset movement amount suitable for the sheet S. Thus, the sheet S in contact with the offset roller 407 is subjected to an alignment process based on the calculated movement amount and is aligned with the positioning wall 416.

  On the other hand, if it is determined that the sheet is the final sheet (Y in S270), a sheet bundle corresponding to the copy document is formed on the processing tray 410, so whether the stapling process is selected next. If it is selected (Y in S280), the stapling unit 420 is driven to execute the stapling process (S290).

  Next, when the stapling process is not selected (N in S280) or after the stapling process is completed, as shown in FIG. 11, the sheet bundle discharging member 413 is turned by the sheet bundle discharging motor 430 by the rotating member 417. Then, the sheet bundle SA is advanced in the direction of the stack tray 421 while being gripped by the sheet clamp member 412, and the sheet bundle SA is discharged and moved (S300).

  At this time, the pressing arm 422 presses the already stacked sheet bundle SB on the stack tray by the cam portion 417a formed on the rotating member 417, thereby preventing the already stacked sheet bundle SB from being pushed out. Yes. Further, the sheet bundle rear end abutting member 418 is retracted in the processing tray.

  Next, when the sheet bundle discharging member 413 reaches the sheet bundle discharging position (the top dead center of the rotating member 417), the pressing arm 422 released from the pressing by the cam portion 417a of the rotating member 417 is below the processing tray 410. Move to the retreat position. Further, the sheet bundle rear end abutting member 418 projects on the processing tray 410 by a cam portion (not shown) provided on the rotating member 417.

  Thereafter, when the sheet bundle discharge member 413 moves back in the direction to return to the home position as shown in FIG. 12B, for example, the sheet clamp member is attached to a not-illustrated engaging portion formed on the top surface of the processing tray 410. As a result, the sheet clamp member 412 that has gripped the sheet bundle SA as shown in FIG. 12A rotates upward to release (hold) the sheet bundle SA.

  As a result, when the sheet bundle discharge member 413 is further moved thereafter, the rear end of the sheet bundle SA held by the sheet bundle discharge member 413 hits the sheet bundle rear end abutting member 418 and hits the stack tray 421. Fall. In this way, the trailing edge of the sheet bundle SA is brought into contact with the sheet bundle trailing edge abutting member 418 and dropped, so that the dropping position of the sheet bundle SA becomes constant, and the sheet bundle is aligned and stacked on the stack tray. Can do.

  Next, the stack tray 421 is moved (lowered) in accordance with the discharge operation of the sheet bundle SA (S310), and then the sheet bundle discharge member 413 is returned to the home position as shown in FIG. (S320). When the sheet bundle discharge member 413 returns to the home position in this way, the pressing arm 422 is returned to the position where the sheet bundle SB is pressed by the cam portion 417a provided on the rotating member 417, and provided on the rotating member 417. The sheet bundle rear end abutting member 418 is moved to a retracted position below the processing tray 410 by the cam portion (not shown).

  Thereafter, the conveyance motor 431 is stopped to stop the rotation of the conveyance roller 405 and the offset roller 407 (S330), the pickup solenoid 433 is turned off (S340), and the offset roller 407 is lowered to complete a series of processing. To do.

  In this embodiment, the sheet bundle discharging means is performed by the rotational movement of the cam. However, the same effect can be obtained by using a belt drive having a clamp mechanism or a reciprocating movement of a rack and pinion. In this embodiment, the stack tray 421 is substantially horizontal, but better alignment can be obtained even if it is adopted in an apparatus having an inclined stack tray 421.

  Furthermore, in this embodiment, the CPU performs control while reading the program on the RAM in which the program corresponding to the flowcharts of FIGS. 13 and 14 is stored, but the configuration is such that the processing on the control program is performed by the hardware. However, the same effect can be obtained.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus including a sheet treatment apparatus according to an embodiment of the present invention. The figure explaining the structure of the said sheet processing apparatus. The figure which shows a mode that a sheet | seat is discharged on the processing tray of the said sheet processing apparatus. The figure explaining the drive mechanism of the offset roller of the said sheet processing apparatus, and a conveyance roller. The figure explaining the drive mechanism of the offset roller of the said sheet processing apparatus, a conveyance roller, a sheet bundle discharge member, and a sheet clamp member. FIG. 6 is a first diagram illustrating the operation of the offset roller and the accompanying sheet movement. FIG. 9 is a second diagram illustrating the operation of the offset roller and the accompanying sheet movement. The figure explaining operation | movement of the said sheet clamp member. FIG. 4 is a diagram illustrating a state where the sheet bundle discharge member discharges a sheet bundle to a stack tray. The block diagram which shows the structure of the control part of the said sheet processing apparatus. The figure explaining the structure of the press arm of the said sheet processing apparatus, and a sheet bundle rear end butting member. The figure explaining the sheet | seat bundle discharge operation | movement of the said sheet processing apparatus. 6 is a flowchart for explaining a part of the sheet processing operation of the sheet processing apparatus. 6 is a flowchart for explaining the remaining part of the sheet processing operation of the sheet processing apparatus. The figure explaining the structure of the conventional sheet processing apparatus.

Explanation of symbols

100 CPU
200 Printer unit 400 Sheet processing device 407 Offset roller 410 Processing tray 411 Sheet rear end stopper 412 Sheet clamp member 413 Sheet bundle discharge member 417 Rotating member 417a Cam unit 418 Sheet bundle rear end abutting member 420 Stapler unit 421 Stack tray 422 Press Arm 433 Pickup solenoid 434 Clamp solenoid 500 Image forming apparatus main body A Image forming apparatus S Sheet SA, SB Sheet bundle

Claims (7)

A first sheet stacking unit configured to stack sheets to be processed; and a sheet bundle that is provided downstream of the first sheet stacking unit in the sheet conveying direction and processed on the first sheet stacking unit and then discharged. A sheet processing apparatus including a second sheet stacking unit for stacking;
After the processing of the sheet bundle is completed, the sheet bundle moves in the direction of the second sheet stacking unit and discharges the processed sheet bundle on the first sheet stacking unit to the second sheet stacking unit. Discharging means;
Sheet bundle pressing means for pressing the sheets stacked on the second sheet stacking means from above;
A pressing position for pressing the sheet bundle pressing means from above; a pressing means moving means for selectively moving the sheet bundle pressing means to a retracted position below the first sheet stacking means;
With
The pressing means moving means moves the sheet bundle pressing means to the retracted position in conjunction with the movement of the sheet bundle discharging means in the sheet bundle discharging direction, and after the sheet bundle discharging operation of the sheet bundle discharging means is completed. A sheet processing apparatus, wherein the sheet bundle pressing means is moved to a pressing position.   2. The sheet processing apparatus according to claim 1, wherein the pressing means moving means is a cam that moves as the sheet bundle discharging means moves.   The sheet bundle discharging means includes a sheet bundle holding means for holding the processed sheet bundle, and after the sheet bundle discharging means has moved to a position for discharging the sheet bundle, the sheet bundle holding means 3. The sheet processing apparatus according to claim 1, wherein the holding is released. A sheet bundle rear end abutting member provided so as to be capable of appearing and retracting at an end of the first sheet stacking unit on the second sheet stacking unit side;
An abutting member moving means for projecting the sheet bundle rear end abutting member from the second sheet stacking means side end of the first sheet stacking means;
With
The abutting member moving means causes the sheet bundle trailing edge abutting member to project upstream of the sheet bundle discharging means after the sheet bundle discharging means has moved to a position for discharging the sheet bundle, and the sheet bundle 4. The sheet processing apparatus according to claim 3, wherein when the discharge means returns to the position before movement, the sheet processing apparatus abuts on the rear end of the sheet bundle released from the holding by the sheet bundle holding means.   5. The sheet processing apparatus according to claim 4, wherein the abutting member moving unit is a cam that moves in accordance with the movement of the sheet bundle discharging unit.   An image forming unit that forms an image on a sheet, and the sheet processing apparatus according to claim 1 that processes a sheet on which an image is formed by the image forming unit. Image forming apparatus. An image forming unit for forming an image on a sheet;
First sheet stacking means for stacking sheets to be processed from the image forming unit;
A second sheet stacking unit that is provided downstream of the first sheet stacking unit in the sheet conveying direction and stacks the sheet bundle that is discharged after being processed on the first sheet stacking unit;
After the processing of the sheet bundle is completed, the sheet bundle moves in the direction of the second sheet stacking unit and discharges the processed sheet bundle on the first sheet stacking unit to the second sheet stacking unit. Discharging means;
Sheet bundle pressing means for pressing the sheets stacked on the second sheet stacking means from above;
A pressing position for pressing the sheet bundle pressing means from above; a pressing means moving means for selectively moving the sheet bundle pressing means to a retracted position below the first sheet stacking means;
In conjunction with the movement of the sheet bundle discharging means in the sheet bundle discharging direction, the sheet bundle pressing means is moved to the retracted position, and after the sheet bundle discharging operation of the sheet bundle discharging means is completed, the sheet bundle pressing means is Means for moving to the pressing position;
An image forming apparatus comprising:

Images