JP2006103844A - Sheet handling device and image forming device equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet handling device capable of improving handling efficiency. <P>SOLUTION: This sheet handling device 400 is provided with a stack tray 421 (422) for loading a sheet, an elevating device for elevating and lowering the stack tray, an inlet sensor 403 for detecting delivery of sheet onto the stack tray, a pressing member 421A for pressing the sheet on the stack tray, a pressing member driving device for moving the pressing member 421A between a pressing position where the pressing member 421A presses the sheet and a retreat position where it retreats from the pressing position, and a CPU for controlling the elevating device to lower the stack tray by predetermined amount after detecting delivery of sheet by the inlet sensor 403, controlling the pressing member driving device to move the pressing member 421A from the pressing position to the retreat position, controlling the pressing member driving device to move the pressing member 421A from the retreat position to the pressing position and abut on an upper face of sheet after that, and controlling the elevating device to start rise of the stack tray. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus including the sheet processing apparatus.

  Conventionally, image forming apparatuses such as copying machines, printers, facsimiles, and composite devices of these are used for the main body of the image forming apparatus, and for sheets discharged from the main body of the image forming apparatus after image formation is completed. Some include a sheet processing apparatus that performs processing such as binding processing.

  Then, the sheet processing apparatus conveys the sheet discharged from the main body of the image forming apparatus to the sheet processing unit, and in this sheet processing unit, stacks and aligns the discharged sheet, and binds (staples) the sheet. A stapling process or the like is performed, and the sheet or the sheet bundle after the completion of the process is discharged to the stack tray.

  A conventional sheet processing apparatus that performs such processing performs processing on a sheet bundle and the like, and discharges and stacks the sheets on a predetermined stacking tray. However, when a large number of sheets are stacked, there is a problem in that a sheet to be discharged pushes out a sheet already stacked on the stacking tray, causing a stacking deviation on the stacking tray. In view of this, a sheet processing apparatus is known in which a sheet already stacked on a stacking tray is pressed by a pressing member to prevent a deviation of a preceding sheet previously stacked by a discharged subsequent sheet (Patent Document 1). reference).

JP-A-11-147666

  A conventional sheet processing apparatus performs an operation of pressing a sheet already stacked on a stacking tray with a pressing member by raising the stacking tray. For this reason, the conventional sheet processing apparatus presses the sheet with the pressing member until the stacking tray is raised, so there is no problem when it is mounted on an image forming apparatus with low productivity, but an image with higher productivity. When mounted on the forming apparatus, it was necessary to increase the lifting speed of the stacking tray in order to quickly press the sheet with the pressing member. As a result, there are problems such as an increase in the cost of the stacking tray driving device.

  Further, in the conventional sheet processing apparatus, when the stapling process is performed on a plurality of sheet bundles, the staple portion of the sheet bundle stacked on the stacking tray is raised due to the thickness of the needle. Therefore, the stacking tray is based on the height of the maximum height of the projected sheet, which is given a margin, so that the sheet discharge port is not blocked by the rising of the sheet bundle. He had set his own lift height. For this reason, it is necessary to take up as much space for raising and lowering the stacking tray as the height that allows for a margin.

  An object of the present invention is to provide a sheet processing apparatus with improved sheet processing efficiency.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which an image forming efficiency is improved by providing a sheet processing apparatus with improved sheet processing efficiency in an apparatus main body.

  In order to achieve the above object, a sheet processing apparatus according to the present invention includes a sheet stacking unit on which sheets are stacked, an elevating unit that moves the sheet stacking unit up and down, and a sheet detection that detects discharge of the sheet to the sheet stacking unit. Means, a sheet pressing means for pressing a sheet on the sheet stacking means, and the sheet pressing means is moved between a pressing position where the sheet pressing means presses the sheet and a retracting position where the sheet is retracted from the pressing position. After the discharge of the sheet is detected by the moving means and the sheet detecting means, the lifting / lowering means is controlled to lower the sheet stacking means by a predetermined amount, and the moving means is controlled to press the sheet pressing means. The sheet pressing unit is moved from the retracted position to the pressing position by controlling the moving unit. Wherein the is brought into contact with the upper surface of the sheet, and a, and a control means for initiating an increase in the sheet stacking means by controlling the lifting means.

  The sheet processing apparatus of the present invention includes a height detection unit that detects whether or not the sheet contact position of the sheet pressing unit has reached a set value or higher when the sheet stacking unit is raised. Yes.

  In the sheet processing apparatus according to the present invention, the sheet pressing unit and the height detecting unit may operate simultaneously when operating separately depending on the state of the sheet discharged to the sheet stacking unit.

  In the sheet processing apparatus of the present invention, the height detection means is disposed at a position where the swelling of the sheet due to the post-processing applied to the upstream end corner of the sheet can be detected.

  In order to achieve the above object, an image forming apparatus according to the present invention includes: an image forming unit that forms an image on a sheet; and a sheet processing device that processes a sheet on which an image is formed by the image forming unit, The sheet processing apparatus is any one of the above sheet processing apparatuses.

  In the sheet processing apparatus of the present invention, when the succeeding sheet bundle is being discharged on the downstream side while being discharged on the downstream side, the preceding sheet stacked on the sheet stacking unit is pressed by the sheet stacking unit by the sheet pressing unit. Therefore, it does not move downstream following the succeeding sheet. For this reason, the sheet processing apparatus of the present invention can improve the alignment of the sheet bundle, and it becomes unnecessary to align the sheet bundle again when the user takes away the sheet bundle, and the handling of the sheet bundle becomes easy.

  In the sheet processing apparatus of the present invention, the control unit controls the moving unit to move the sheet pressing unit from the retracted position to the pressing position and contact the sheet upper surface, and then controls the lifting unit to control the sheet stacking unit. As a result, the sheet processing time is improved and the sheet processing time is improved as compared with the case where the sheet stacking means is raised and the sheet pressing means is used to hold the sheet bundle. Can be shortened, and the productivity of sheet processing can be improved.

  The sheet processing apparatus of the present invention includes a height detection unit that detects whether or not the sheet contact position of the sheet pressing unit has reached a set value or higher when the sheet stacking unit is raised. The height position of the uppermost sheet can always be the same, and the sheet drop distance is the same, so that the sheet alignment is not impaired.

  In the sheet processing apparatus of the present invention, when the sheet pressing unit and the height detecting unit operate separately depending on the state of the sheet discharged to the sheet stacking unit, the height detecting unit may operate at the same time. Even if the sheet stacking unit moves with some inertia after the sheet is detected, the sheet pressing unit can maintain the state of pressing the sheet, and the sheet alignment is impaired. There is no such thing.

  In the sheet processing apparatus according to the present invention, since the height detection means is disposed at a position where the swelling of the sheet due to the post-processing applied to the upstream end corner portion of the sheet can be detected, the sheet that is conventionally predicted The height of the sheet stacking means was set based on the maximum height of the raised height plus the height that allowed the margin, whereas the height that allowed the margin was This eliminates the need for a large space for lifting and lowering the sheet stacking means, thereby reducing the size of the apparatus.

  Since the image forming apparatus of the present invention includes the sheet processing apparatus that shortens the sheet processing time, the image forming efficiency can be increased and the productivity can be improved.

  Hereinafter, a sheet processing apparatus according to an embodiment of the present invention and an image forming apparatus including the sheet processing apparatus in an apparatus main body, for example, a copying machine will be described with reference to the drawings.

  FIG. 1 is a front view of a schematic configuration of a copier equipped with a sheet processing apparatus of the present invention in an apparatus main body.

  Examples of the image forming apparatus include a copying machine, a facsimile, a printer, and a complex machine of these. Therefore, the image forming apparatus is not limited to a copying machine.

  Further, the sheet processing apparatus 400 of the present invention is not connected only to the apparatus main body 500A of the copying machine 500. The sheet processing apparatus 400 is separate from the apparatus main body 500A of the copier 500, but may be incorporated in the apparatus main body 500A.

  Further, the sheet processing apparatus of the present embodiment includes a stapler unit 420 (see FIGS. 2 and 4) to bind a sheet bundle. However, instead of the stapler unit 420, a sheet punching apparatus is provided to form a sheet bundle. A hole may be made. Therefore, the sheet processing apparatus is not limited to binding a sheet bundle. Furthermore, a stapler unit and a punching device are not necessarily required. The sheet processing apparatus may have at least a function of aligning the trailing edge of the sheet.

  In the present invention, the upstream end in the sheet conveying direction of the sheet is referred to as the rear end, the downstream end is referred to as the leading end, and the end along the sheet conveying direction is referred to as the side end. Further, the direction intersecting the sheet conveying direction is called the sheet width. Therefore, aligning the rear end of the sheet is referred to as rear end alignment, and aligning the side end is referred to as side end alignment. Aligning the sheet width is called width alignment. When aligning the widths of sheets having the same width, the side edge alignment and the width alignment mean the same alignment.

  The copying machine 500 includes a reader unit 120, an image forming unit such as a printer unit 200, a sheet processing apparatus 400, and the like. An automatic document feeder 300 (hereinafter referred to as “ADF”) for supplying documents one by one onto the platen glass 102 is provided on the upper part of the apparatus main body 500A of the copying machine 500. A sheet processing apparatus 400 that performs post-processing of sheets discharged from the copying machine 500 is connected to the apparatus main body 500A of the copying machine 500.

  The copying machine 500 reads an image of a document supplied by the ADF 300 with the reader unit 120 or reads an image of a document placed on the platen glass 102 of the reader unit 120 by the user with the reader unit 120. In addition to functioning as a copying machine for copying on a sheet by the unit 200, the printer unit 200 receives an image signal sent from an external personal computer and functions as a printer for forming the image signal on a sheet. Yes. Further, the copier 500 transmits an image signal read by the reader unit 120 to another facsimile, or receives a facsimile signal from another facsimile by the printer unit 200, and prints an image on a sheet based on the signal. It also functions as a facsimile machine to be formed.

  When the copying machine 500 reads a document image to form an image, first, a document (not shown) loaded on an automatic document feeder (ADF) 300 is sequentially transferred one by one by the ADF 300 to the reader unit 120. It is conveyed on the platen glass 102.

  Next, when the document is conveyed to a predetermined position on the platen glass 102, the lamp 103 of the reader unit 120 is turned on, and the scanner unit 104 is moved 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 way is converted into a modulated optical signal by the exposure control unit 201 of the printer 200. The exposure control unit 201 irradiates the photosensitive drum 202 with an optical signal as a laser beam. A latent image is formed on the photosensitive drum 202 by the irradiation light. This latent image is developed by the developing device 203 and becomes a toner image 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. The toner image transferred to the sheet S is fixed by the fixing unit 207. Thereafter, the sheet S is discharged from the sheet discharge unit 208 to the outside of the apparatus main body 500A.

  Next, after the image formation is completed as described above, the sheet S discharged from the sheet discharge unit 208 is conveyed to the sheet processing apparatus 400, and is sorted and bound according to an operation mode designated in advance by the sheet processing apparatus 400. Are stacked on a tray (stack tray 421 or stack tray 422) which is a desired sheet stacking unit.

  Next, the sheet processing apparatus 400 will be described.

  As shown in FIG. 1, the sheet processing apparatus 400 is accommodated in a space SP formed in a side portion of the apparatus main body 500A of the copying machine 500 without protruding from the apparatus main body 500A of the copying machine. The sheet processing apparatus 400 includes a stapling function that is, for example, a binding operation by the stapler unit 420 illustrated in FIG. 4 in addition to a sorting operation for sorting sheets. As shown in FIG. 2, the sheet processing apparatus finally stacks a processing tray 410 for processing sheets S sequentially discharged from the apparatus main body 500 of the copying machine and a sheet bundle processed on the processing tray 410. A stack tray (lower bin) 421, a stack tray (upper bin) 422, and the like are formed on the processing tray, and a stack tray (lower bin) 421 is formed for each sheet bundle. Alternatively, the stack tray (upper bin) 422 can be discharged and stacked.

  The sheet processing apparatus 400 has an unconventional configuration in which a plurality (two in the present embodiment) of stack trays 421 and 422 can be moved up and down independently. Further, the sheet processing apparatus 400 is not limited to a simple copy job, but can separate and stack the stack trays 421 and 422 in order to output sheets away from an image forming apparatus such as a printer or a facsimile. It has a structure that can contribute greatly.

  Although the reader unit 120 and the automatic document feeder (ADF) 300 are provided on the upper part of the apparatus main body 500A of the copying machine 500, a sheet processing apparatus 400 may be provided instead. As described above, by providing the sheet processing apparatus 400 in the installation space of the apparatus main body, the installation space of the copying machine can be reduced.

  Next, the configuration of the sheet processing apparatus 400 will be described.

  In FIG. 2, a sheet receiving unit 401 receives the sheet S discharged from the apparatus main body 500A of the copying machine. After the sheet S received by the sheet receiving unit 401 is detected by the entrance sensor 403, the sheet S is transported and stacked on the processing tray 410 by the transport roller 405 and the offset roller 407 (see FIG. 3). The processing tray 410 is provided in the sheet processing unit 400B that processes sheets. The sheets S stacked on the processing tray 410 are detected by a sheet bundle discharge sensor 415 shown in FIG.

  The offset roller 407 is configured by a cylindrical member. The cylindrical member is formed of an elastic body whose outer peripheral portion has elasticity close to rubber, such as rubber or foam. The offset roller 407 is supported by the offset roller holder 406. The offset roller holder 406 is rotated up and down by a pickup solenoid 433 with an offset shaft 511 as a fulcrum. That is, the offset roller 407 is raised and lowered via the solenoid arm 512, the lever holder 513, the separation lever 514, and the offset roller holder 406 when the pickup solenoid 433 is turned on / off.

  Further, when the sheet S is discharged to the processing tray 410, the offset roller 407 prevents the discharge of the sheet S via the solenoid arm 512, the lever holder 513, the separation lever 514, and the offset roller holder 406 when the pickup solenoid 433 is turned on. Not to move to an upper position. Thus, the sheet S is discharged and stacked on the processing tray 410 without being obstructed by the offset roller 407.

  Further, the offset roller 407 is passed through a timing belt 523, a roller gear 524, an idler gear 525, an offset gear 526, an offset pulley 527, and a timing belt 522 by a transport motor 431 capable of rotating forward and backward to drive the transport roller 405 shown in FIG. It is designed to rotate. When the transport motor 431 rotates, the offset roller 407 rotates in the transport direction by the amount corresponding to the rotation amount of the transport motor 431 (forward rotation), or rotates in the direction opposite to the transport direction (hereinafter referred to as reverse rotation). ing.

  The pickup solenoid 433 is turned off by a detection signal that passes through the rear end of the sheet from the entrance sensor 403 shown in FIG. When the pickup solenoid 433 is turned off, the offset roller 407 descends by its own weight while rotating in the sheet conveying direction and landed (contacts) on the sheet, and after the sheet has been conveyed downstream in the sheet conveying direction for a predetermined time. Further, when a predetermined time elapses, the sheet is reversed and returned to the upstream side in the sheet conveying direction.

  As described above, the offset roller 407 is reversely rotated so that the rear end (upstream end) of the sheet abuts against the sheet rear end stopper 411 to align the rear end of the sheet S. The sheet trailing edge stopper 411 is erected on the upstream end of the processing tray 410 in the conveyance direction so as to receive the sheet trailing edge. Therefore, the trailing edge alignment of the sheet is performed by the offset roller 407 abutting the trailing edge of the sheet against the sheet trailing edge stopper 411.

  In FIG. 4, the width-direction positioning wall 416 receives the side edge of the sheet and can align the side edge of the sheet. The stapler unit 420 is disposed in the vicinity of the width direction positioning wall 416 and binds the sheet bundle formed on the processing tray 410.

  The offset roller 407 moves in the width direction of the sheet via the offset motor gear 432a, the offset pinion 516, and the offset rack 515 by driving the offset motor 432 capable of forward and reverse rotation so as to approach and separate from the width direction positioning wall 416. It has become.

  The sheet abutted against the sheet trailing edge stopper 411 and aligned at the trailing edge is dragged in the direction of the width direction positioning wall 416 by the frictional force of the offset roller 407 as the offset roller 407 approaches the width direction positioning wall 416. While being moved as described above, the curl is corrected by the sheet press 510 and brought into contact with the width direction positioning wall 416 so that the side edges are aligned. After the sheet S hits the width direction positioning wall 416, the offset roller 407 is moved by a predetermined amount toward the width direction positioning wall 416 while being slightly slid on the sheet.

  Therefore, when the sheet processing apparatus 400 includes the offset roller 407 that performs the above-described operation, the sheet discharged onto the processing tray 410 is rotated in the sheet conveyance direction as illustrated in FIG. 407 is temporarily transported to the stack trays 421 and 422 (downstream in the sheet transport direction) and then transported upstream by the reverse rotation of the offset roller 407 as shown in FIG. The rear end is aligned.

  The sheet with the rear end aligned is then dragged by the offset roller 407 contacting the sheet being moved to the width direction positioning wall 416 side along the offset shaft 511 as shown in FIG. 5C. Abutting against the width direction positioning wall 416, side end alignment is performed.

  The offset roller 407 shown in FIGS. 5 to 7 and FIG. 24 is located between a pair of offset roller holders 406, unlike the offset roller 407 shown in FIG. Is merely a design difference, and has the same configuration and operation as the offset roller 407 shown in FIG.

  4 and 5, the sheet clamp member 412 sandwiches the rear end portion of the aligned sheet S with a pair of claws 412c and 412d by the urging force of the urging portion 560 (see FIG. 4). . The upper claw 412c opens and closes with respect to the lower claw 412d. After the side alignment of the sheet S is performed, the sheet clamp member 412 is aligned when the offset roller 407 is lifted by the pickup solenoid 433 (see FIG. 4) as shown in FIG. The formed sheet S is sandwiched as shown in FIG.

  By sandwiching the sheet S, the sheet clamp member 412 prevents the sheet S previously discharged (conveyed) from the processing tray 410 from being conveyed to the downstream side by the sequentially fed sheets S. It is supposed to be.

  Further, the sheet clamp member 412 is rotated upward and opened as shown in FIG. 7A so that the sheet S can be received when the offset roller 407 is reversely rotated. Further, the sheet clamp member 412 is configured as shown in FIG. 7B so as not to be a load of movement of the sheet S even when the offset roller 407 moves the sheet whose side edge is aligned toward the width direction positioning wall 416. It pivots upward to open.

  In FIG. 8, the sheet bundle discharging member 413 is configured to discharge the processed sheet bundle to the stack tray (lower bin) 421 or the stack tray (upper bin) 422. The sheet bundle discharge member 413 includes a claw 412c on the upper side of the sheet clamp member 412 so as to be rotatable. The sheet bundle discharging member 413 holds the aligned sheet bundle or the stapled sheet bundle after being aligned by the sheet clamp member 412, as shown in FIG. It moves toward a stack tray (lower bin) 421 or a stack tray (upper bin) 422 provided on the downstream side.

  When the sheet bundle discharge member 413 reaches the front end of the processing tray 410, which is the sheet discharge position indicated by the solid line in FIG. 9, the sheet bundle discharge member 413 stops on the stack trays 421 and 422 while holding the sheet bundle SA by the sheet clamp member 412. When the sheet clamp member 412 releases the sheet bundle SA, the sheet clamp member 412 returns to the sheet trailing edge stopper 411. The released sheet bundle SA falls onto the trays 421 and 422.

  As described above, in the sheet processing apparatus 400 according to the present embodiment, the sheet bundle SA is transported to the stack trays 421 and 422 by the sheet clamp member 412 and dropped. Therefore, conventionally, the stack tray is inclined by about 30 degrees. However, the sheet bundle can be stacked in a stable state at an angle smaller than that of about 9 degrees, and can be installed in a space whose height direction is limited.

  The sheet bundle SA discharged and stacked on the stack trays 421 and 422 in this way is pressed against the stack trays 421 and 422 by, for example, a pressing member 421A which is a sheet pressing unit shown in FIG. As described above, in the sheet processing apparatus 400, since the pressing member 421A is configured to press the sheet bundle SA onto the stack trays 421 and 422, it is possible not only to prevent a decrease in the stacking amount due to the curling of the sheets, but also to be stacked. Further, it is possible to prevent a decrease in stacking performance such as the preceding sheet being pushed by the succeeding sheet and the stacking position of the preceding sheet being shifted. As a result, the sheet processing apparatus achieves stable stacking performance in a limited space with a small substantially horizontal angle as in the present embodiment without providing the conventional stack tray angle inclined about 30 degrees. be able to.

  Here, a pin A553a and a pin B554a suspended from a slide gear A553 and a slide gear B554 that rotate via a belt 551 and a pulley gear 552 by driving the sheet bundle discharge motor 430 shown in FIG. The sheet bundle discharge member 413 is moved by moving in a guide slit (not shown) formed in the sheet bundle discharge member 413 while rotating integrally with the gear B554.

  With this configuration, the sheet bundle discharge member 413 discharges the sheet to the stack tray (1 lower bin) 421 or the stack tray (2 upper bin) 422 by the sheet bundle discharge motor 430 (see FIG. 8). (See (b)), and reciprocates along the slide rail 555 (see (a) and (b) in FIG. 8) to the home position near the seat trailing edge stopper 411 (see FIGS. 2 to 7). ing. The sheet bundle discharge member 413 is normally fixed at the home position by excitation of the sheet bundle discharge motor 430.

  In FIG. 10, the clamp solenoid 434 rotates the sheet clamp member 412. The clamp solenoid 434 is turned on when the offset roller 407 conveys the sheet downstream and then stops rotating, or when the offset roller 407 moves in the width direction, and is provided in the lever 434a and the sheet clamp member 412. The upper claw 412c of the sheet clamp member is rotated upward via the release lever portion 412a.

  In addition, as shown in FIG. 11A, the pressing member 421A shown in FIG. 2 is inserted via a press member 556, a lever member 557, and a coil spring 558 by a cam B 554b installed at the lower part of the slide gear B 554. Power is transmitted and it is designed to rotate up and down. Further, as shown in FIG. 11B, the holding member 421A moves away from the sheet stacking surface of the stack trays 421 and 422 by the return coil spring 559 as shown in FIG. It is like that.

  The holding member 421 </ b> A rotates the slide gear A <b> 553 and the slide gear B <b> 554 by the rotation of the bundle discharge motor 430, so that the sheet bundle discharge member 413 discharges the sheet bundle to the stack trays 421 and 422, and When the pressing is released, the return coil spring 559 separates the sheets from the stack trays 421 and 422 so that the sheet bundle falls onto the stack trays 421 and 422.

  Thereafter, while the sheet bundle falls to the stack trays 421 and 422 and the sheet bundle discharge member 413 returns to the sheet rear end stopper 411, the cam B554b below the slide gear B554 operates the press member 556, and the lever member 557, The pressing member 421A is rotated via the coil spring 558, and the sheet bundle is held by the pressing member 412A.

  The bundle discharge motor 430, the slide gear A553, the slide gear B554, the sheet bundle discharge member 413, the cam B554b, the press member 556, the return coil spring 559, and the like constitute a pressing member driving device 508 that is a moving means. .

  In FIG. 12A, the sheet surface detection flag 570 is installed on the shaft portion 421Aa of the pressing member 421A. Here, a convex portion 570 a is formed in a part of the hole of the sheet surface detection flag 570. Further, a recess 421Aaa is formed in a part of the shaft portion 421Aa. As shown in FIG. 12A, when the sheet bundle is not stacked on the stack tray 421, the convex portion 570a of the hole of the sheet surface detection flag 570 comes into contact with the concave portion 421Aaa of the shaft portion 421Aa by the tension spring 571. Yes.

  As described above, when the convex portion 570a is formed on the sheet surface detection flag 570 and the concave portion 421Aaa is formed on the shaft portion 421Aa of the pressing member 421A, the region where the sheet surface detection flag 570 and the pressing member 421A operate simultaneously is separated. And a region that works.

  The sheet surface detection flag 570 is disposed at a position near the stapler unit 420 (see FIG. 4). Since the sheet surface detection flag 570 is originally retracted below the processing tray 410 as shown in FIG. 12B, it is in an invisible position in FIG. In order to make it easy to do, it is shown protruding as shown in FIG.

  In this embodiment, FIG. 12 and FIG. 13 show that the sheet bundle is discharged to the stack tray 421 (422) by the sheet bundle discharge member 413 and pressed by the pressing member 421A, and the stack tray 421 (422) becomes the next sheet bundle. It is a figure explaining the operation | movement which moves to the position which receives. The same applies to the case where the sheet bundle is discharged to the stack tray 422. Therefore, the case where the sheet bundle is discharged to one stack tray 421 will be described. Although the case where the bound sheet bundle is discharged will be described, the same applies to the case where the sheets that are not stapled are discharged one by one, and only the case where the sheet bundle is discharged will be described.

  First, FIG. 12A shows a state in which the sheet bundle is moved in the arrow U direction by the sheet bundle discharge member 413. Then, as shown in FIG. 12B, the stack tray 421 starts to descend, and the cam below the slide gear B554 that operates the sheet bundle discharge member 413 in accordance with the sheet bundle discharge of the sheet bundle discharge member 413. The pressing of the B554b against the pressing member 556 is released, and the return coil spring 559 retracts the pressing member 421A below the processing tray 410 so as not to prevent the sheet bundle from dropping. Here, the sheet surface detection flag 570 retracts in accordance with the operation of the pressing member 421A in a state where the convex portion 570a of the hole is in contact with the concave portion 421Aaa of the shaft portion 421Aa.

  Note that the slide gear B554 starts to move when the sheet bundle discharge motor 430 starts when a predetermined time elapses after the sheet detection means, for example, the inlet sensor 403 (see FIG. 2) detects the sheet. It has become. Therefore, the timing at which the pressing member 421A is retracted below the processing tray 410 is determined based on the sheet detection operation of the entrance sensor 403, and the sheet bundle is released by the sheet bundle discharge member 413 and falls onto the stack tray 421. It is set to be immediately before.

  Then, as shown in FIG. 13A, after the sheet bundle is placed on the stack tray 421 and the stack tray 421 is lowered by a predetermined amount, or while the stack tray 421 is lowered, the cam B 554b below the slide gear B 554 presses the press member 556. Then, the holding member 421 </ b> A is rotated via the coil spring 558. The pressing member 421A presses the sheet bundle against the stack tray 421 (422).

  The lowering amount of the stack tray 421 is smaller than the movable region of the pressing member 421A, and the spring pressure of the coil spring 558 is applied to the sheet bundle via the pressing member 421A even when the stack tray 421 (422) is lowered. Can tell.

  For this reason, the pressing member 421A can reliably press the sheet bundle against the stack tray 421 (422).

  Further, after the sheet bundle is discharged to the stack tray 421 (422), the downstream end (front end) of the sheet sent from the apparatus main body 500A of the copier 500 is stacked on the stack tray 421 (422). The time until contact with the bundle can be shortened. That is, it can contribute to productivity improvement.

  As shown in FIG. 13A, the sheet surface detection flag 570 rotates in the same direction as the pressing member 421A rotates, but the rotation is restricted by the stopper 572 and stopped. At this time, the sheet surface detection flag 570 is located away from the sheet surface detection sensor 573. The reason why the pressing member 421A is allowed to rotate in a state where the rotation of the sheet surface detection flag 570 is restricted is that the convex portion 570a moves within the concave portion 421Aaa. The sheet surface detection flag 570 and the sheet surface detection sensor 573 are an example constituting a height detection unit.

  FIG. 13B is an operation explanatory diagram of the sheet surface detection flag 570 that rotates in conjunction with the movement of the pressing member 421A.

  As shown in FIG. 13B, the stack tray 421 is raised, and the presser member 421A is pushed by the sheet bundle along with the rise, and is rotated in the retracting direction (counterclockwise direction in the figure). Thereafter, the convex portion 570a of the sheet surface detection flag 570 comes into contact with the concave portion 421Aaa of the shaft portion 421Aa, and the sheet surface detection flag 570 is rotated in the same direction to turn on the sheet surface detection sensor 573. As a result, the stack tray 421 stops rising.

  When the sheet bundle bound to the stapler unit 420 is stacked on the plural stack tray 421, the thickness of the portion bound by the staple is increased. For this reason, as the stack tray 421 rises, the sheet surface detection flag 570 comes into contact with the upstream end of the upper surface of the sheet bundle, turns on the sheet surface detection sensor 573, and stops the rise of the stack tray 421.

  As described above, the sheet processing apparatus 400 according to the present embodiment is configured to detect the portion where the sheet surface detection flag 570 is bound by the staple, and thus, conventionally, the maximum height of the projected sheet is expected to increase. Unlike the case where the height of raising and lowering the stack tray itself is set based on the height obtained by adding the height with a margin to the height, it is not necessary to lower the stack tray 421 by the margin. The space for raising and lowering the stack tray 421 can be narrowed to make the entire apparatus compact.

  As described above, the sheet processing apparatus 400 according to the present embodiment presses the sheet bundle with the pressing member before the stack tray moves up. For this reason, the sheet processing apparatus 400 according to the present embodiment improves sheet processing efficiency in comparison with a sheet processing apparatus that conventionally presses a sheet bundle with a pressing member after the stack tray has been raised. Time can be shortened and sheet processing productivity can be improved.

  In addition, the sheet processing apparatus 400 according to the present embodiment suppresses the preceding sheet bundle loaded on the stack tray 421 (422) when the succeeding sheet bundle is discharged on the downstream side while being discharged on the downstream side. Since the member 421 holds the stack tray 421 (422), it does not move downstream following the subsequent sheet bundle. For this reason, the sheet processing apparatus 400 of the present embodiment can improve the consistency of the sheet bundle discharged and stacked on the stack tray 421 (422), and the sheet bundle can be removed when the user takes away the sheet bundle. There is no need to align again, and handling of the sheet bundle becomes easy.

  When the subsequent sheet bundle is stacked on the stack tray 421, the stack tray 421 is raised again, and when the subsequent sheet bundle is detected by the sheet surface detection flag 570 and the sheet surface detection sensor 573, the rising is stopped. In this way, the stack tray 421 stops so that the uppermost sheet of the uppermost sheet bundle among the sheet bundles stacked on the stack tray 421 coincides with a predetermined position. Therefore, the pressing member 421A can press the sheet bundle with a substantially constant pressing force that is the minimum necessary regardless of the thickness of the sheet bundle.

  As described above, in the sheet processing apparatus 400 according to the present embodiment, the sheet surface detection flag 570 can operate independently. Therefore, a plurality of sheet bundles bound by the stapler unit 420 are stacked on the stack tray 421 (422). As a result, the sheet surface rises and becomes higher than the surface of the processing tray 410, and sheet conveyance jam due to contact with the subsequent sheet can be prevented.

  Further, in the sheet processing apparatus 400 of the present embodiment, the sheet surface detection flag 570 can detect partial sheet surfaces of a plurality of bound sheet bundles. When there is a situation where the movable range of the stack tray 421 (422) is restricted, it is not necessary to set 421 (422) low, and more sheets can be stacked.

  In the meantime, the sheet processing apparatus 400 according to the present embodiment moves the sheet S in the width direction as described above, performs the side edge alignment, and then corrects the deviation in the trailing edge alignment of the sheet. The rear end alignment is performed again by reversing the rotation. As a result, the sheet processing apparatus 400 according to the present embodiment can perform highly accurate rear-end alignment and side-end alignment of sheets. When the alignment process for the designated number of sheets is completed, the clamp solenoid 434 closes the sheet clamp member 412 and holds the sheet bundle.

  Next, FIG. 14 is a diagram of an elevating device 507 that is an elevating unit for elevating and lowering the stack tray. The operation of the stack trays 421 and 422 will be described based on FIG. First, the rotational force of the stack tray lifting / lowering motor 530 is transmitted to the worm gear a 534 and the worm gear b 535 at both ends of the rotating shaft via the belt 531, the pulley 532, and the rotating shaft 533.

  The rotational force of the worm gear a534 is transmitted from the gear 1a537 formed integrally with the worm wheel a536 and the worm wheel a536 to the gear 2a538, and further linearly moved from the gear 3a539 formed integrally with the gear 2a538 to the rack a540. As transmitted.

  Similarly, the rotational force of the worm gear b535 is transmitted from the gear 1b542 formed integrally with the worm wheel b541 and the worm wheel b541 to the gear 2b544, and further linearly from the gear 3b543 formed integrally with the gear 2b544 to the rack b545. It is transmitted as movement. Finally, the stack trays 421 and 422 are moved up and down by the linear motion of the rack a540 and the rack b545.

  In FIG. 14, the clutch a 560 rotates in conjunction with the pulley 532. A coil spring 561 is wound around the clutch a560. The opposite side of the coil spring 561 is wound around the clutch b562. Further, a pin 563 that is press-fitted into the rotary shaft 533 is engaged with the groove of the clutch b562. With such a configuration, a desired rotational torque of the stack tray lifting / lowering motor 530 is transmitted to the rotating shaft 533, and the rotational force is transmitted to the worm gear a534 and the worm gear b535 at both ends of the rotating shaft 533.

  By the way, when stack trays 421 and 422 are provided so as to be able to move up and down in a sheet stacking space SP1, which will be described later, when the stack trays 421 and 422 continue to rise without stopping at a predetermined position for some reason, In addition to the sheets 422 or the sheets stacked on the stack trays 421 and 422 striking the upper stack tray, the uppermost stack tray (upper bin) 422 or the reader unit 120 whose sheet is the upper surface of the sheet stacking space SP1. There is a risk of hitting the bottom surface (see FIG. 1). For this reason, the sheet post-processing apparatus 420 of the present embodiment includes an upper limit sensor 547 as an example of a sensor for restricting the movement of the stack tray (upper bin) 422 as described later.

  However, for example, when foreign matter is mixed on the stack tray (upper bin) 422 or when a large amount of sheets are stacked, before the stack tray (upper bin) 422 is detected by the upper limit sensor 547. There is a possibility that the foreign matter or the sheet may hit the upper surface of the sheet stacking space SP1.

  Here, if the stack tray (upper bin) 422 continues to rise after the foreign object or sheet hits in this way, the foreign object, sheet, or stack tray (upper bin) 422 may be damaged. In the sheet processing apparatus 400 of the present embodiment, as described above, the coil spring 561 as an example of the restricting unit is provided between the stack tray lifting / lowering motor 530 and the stack tray (upper bin) 422 (421). When the torque for raising the stack tray (upper bin) 422 is greater than a predetermined torque, the drive of the stack tray lifting / lowering motor 530 is not transmitted to the stack tray (upper bin) 422.

  That is, when a foreign object or sheet hits the upper surface of the sheet stacking space SP1 and then a load exceeding the torque set by the coil spring 561 is generated, the drive of the stack tray lifting / lowering motor 530 is transmitted to the stack tray (upper bin) 422. The rotation shaft 533 stops rotating, and the stack tray (upper bin) 422 no longer rises. After this, if the upper limit sensor 547 does not detect the stack tray (upper bin) 422 even after a predetermined time has elapsed, the CPU 100 described later stops driving the stack tray lifting / lowering motor 530 and controls the stack tray (upper bin) 422. I try to stop the climb.

  As described above, when the foreign matter or the sheet hits the upper surface of the sheet stacking space SP1, the stack spring (upper bin) 422 is restricted by the coil spring 561, whereby the stack tray (upper bin) 422 or the stack tray ( It is possible to prevent damage of sheets and the like stacked on the upper bin 422.

  FIG. 25 shows, for example, an elevating device 509 that is another elevating means for stopping the ascent of the stack tray (upper bin) 422 when a foreign object or a sheet hits the upper surface of the sheet stacking space SP1. In this configuration, equally-spaced slits (encoders) are provided in the disk portion 562a of the clutch b562, and the rotation and stop of the rotating shaft 533 are detected by the encoder and the sensor 564.

  Here, in such a configuration, if foreign matter enters before the stack tray (upper bin) 422 is fully raised, the load becomes heavy, and the rotation shaft 533 stops rotating at a load greater than the set torque. Then, the ON / OFF operation of the sensor 564 is stopped, and when this is detected by, for example, the CPU 100 as the control means, the driving of the stack tray lifting / lowering motor 530 is stopped and the raising of the stack tray (upper bin) 422 is stopped. .

  Next, the operation at the time of tray switching between the stack tray (lower bin) 421 and the stack tray (upper bin) 422 will be described.

  As described with reference to FIG. 14, the stack tray (lower bin) 421 and the stack tray (upper bin) 422 can be moved up and down independently by the stack tray lifting motor 530 via the rack and pinion. Each of the stack tray (lower bin) 421 and the stack tray (upper bin) 422 has a drive source independently, and is processed up and down to be discharged by the sheet bundle discharge member 413. Can be received selectively.

  In the state of FIG. 1 or FIG. 2 in which a plurality of (NO) (two in this embodiment) stack trays are normally placed on standby with the sheet discharge port 400A for sheets discharged by the sheet bundle discharge member interposed therebetween. Since the space is provided below the stack tray (lower bin) 421, not only can a large number of sheets be stacked, but the upper and lower bins can be switched according to the contents described later even when the stack tray (upper bin) 422 is in the retracted state. Since the upper bin can be stacked, more sheets can be stacked.

  Here, in the case where the stack tray (lower bin) 421 is in a position where sheets can be received and the stack tray (upper bin) 422 is retracted to the upper side (FIG. 15A), the stack tray (upper bin) ) The movement of 422 to a position where the sheet below the sheet discharge port 400A can be received will be described.

  A lower limit sensor 546 capable of detecting a lower limit is provided below the stack tray (lower bin) 421. In this operation, the stack tray (lower bin) 421 is first lowered to a position detected by the lower limit sensor 546. At this time, the pressing member 421A moves to the retracted position indicated by the solid line (FIG. 15B).

  Next, the pickup solenoid 433 shown in FIG. 4 is turned on, and the electromagnetic clutch 517 is turned on with the offset roller 407 moved to the upper standby position via the offset roller holder 406 as shown in FIG. After the conveying motor 431 is connected by the rotation of the conveying motor 431, the conveying motor 431 is rotated by a predetermined amount, so that the gear portion 517a, the idler gear 518, the cam gear 519, and the shutter lever of the electromagnetic clutch 517 are rotated as shown in FIG. The shutter 521 is lowered via 520.

  Then, the shutter 521 is lowered in this way and closes the sheet discharge port 400A of the processing tray 410, so that a guide surface at the rear end of the sheet is formed by the sitter 521 (FIG. 17A). As a result, in the sheet processing apparatus 400 of the present embodiment, when the stack tray (upper bin) 422 is moved up and down, sheets already stacked on the stack tray (upper bin) 422 do not flow back into the processing tray 410 and enter. It is like that.

  Next, when the lowering of the shutter 521 is completed, the stack tray (upper bin) 422 starts to lower and stops at a position where it has passed the pressing member 421A (FIG. 17B). Thereafter, the shutter 521 moves up and stops at a desired position. Then, the holding member 421A that has been retracted rotates to a position where the sheet can be pressed. The stack tray (upper bin) 422 rises to a position for receiving a sheet and stops (FIG. 18A). Thereafter, the stack tray (upper bin) 422 can receive sheets in the same manner as the stack tray (lower bin) 421.

  Next, the stack tray (upper bin) 422 is in a position where the sheet can be received, and the stack tray (lower bin) 421 is retracted downward (FIG. 18A). The operation of moving up and down will be described.

  First, the pressing member 421A returns to the retracted position. The shutter 521 descends to prevent sheets already stacked on the stack tray (upper bin) 422 from flowing back from the sheet discharge port 400A toward the processing tray (FIG. 18B). Thereafter, the stack tray (upper bin) 422 starts to rise. The stack tray 422 passes through the sheet discharge port 400A and rises to the space SPU provided above the sheet discharge port 400A.

  Then, the stack tray (upper bin) 422 moves up the space SPU 12 provided above the sheet discharge port 400A, and near the upper limit of the space SPU (in this embodiment, the bottom surface of the reader unit 120 (see FIG. 1). When the upper limit sensor 547 provided in the vicinity) is detected, the stack tray lifting / lowering motor 530 is stopped, so that the rising is stopped (FIG. 19A).

  Next, the shutter 521 moves up to a desired position, opens the sheet discharge port 400A, and then stops (FIG. 19B). Next, the holding member 421 </ b> A that has been retracted rotates to a state where the sheet can be pressed. The stack tray (lower bin) 421 moves up to a sheet receiving position and stops (FIG. 15A). By moving to this position, the stack tray (lower bin) 421 can receive sheets.

  A plurality of stack trays 421 and 422 can be independently lifted and lowered in the sheet processing apparatus 400 stored in the space SP (see FIG. 1) formed in the side portion of the apparatus main body 500A of the copying machine in this manner. By enabling the sheets to be selectively stacked on the stack trays 421 and 422, even when the sheet processing apparatus 400 is incorporated in a composite printer having a mode such as a copying machine, a printer, or a facsimile, it can be saved. It is possible to easily distinguish between the sheets that are available and in which mode the sheets are output.

  In addition, sorting and stacking according to modes such as copy, printer, and facsimile becomes possible, and an apparatus optimal for office needs can be provided.

  Further, by moving the stack tray (upper bin) 421 above the sheet discharge port 400A, the stack trays 421 and 422 can be moved up and down in the space SP formed in the side portion of the apparatus main body 500A of the copying machine. The space SPU above the sheet discharge port 400A in the sheet stacking space SP1 to be used can be used as a sheet stacking space, whereby a large number of sheets can be stacked.

  When the space SPU above the sheet discharge port 400A is used as a sheet stacking space, it is preferable to provide the sheet discharge port 400A at a substantially center in the height direction of the sheet stacking space SP1. By providing the sheet discharge port 400A at such a position, a large amount of sheets can be stacked using the sheet stacking space SP1 efficiently.

  In the description so far, the case where two stack trays are provided has been described. However, a plurality (NO) of stack trays are provided, and a space SPU above the sheet discharge port 400A is provided as a stack of a plurality (NO) of sheets. If (n-1) stack trays of the means are movable, it is possible to stack a large amount of sheets by efficiently using the limited sheet stacking space SP1.

  Further, if the sheet discharge port 400A is used as a common sheet discharge port in a mode such as a copying machine, a printer, and a facsimile, and sheets are selectively discharged from the common sheet discharge port 400A to a plurality of stack trays, space saving is achieved. And the height dimension can be suppressed.

  In addition, when the sheet discharge port 400A is a common sheet discharge port and the sheets are discharged from the sheet discharge port 400A to the stack tray by one sheet bundle discharge member 413, the configuration can be simplified. Cost can also be reduced.

  Note that, as shown in FIG. 20A, a sub-tray 421a as a spare sheet stacking unit is housed in the downstream end of the stack trays 421 and 422 in the sheet discharge direction so as to be drawable. The stack trays 421 and 422 are arranged so as not to protrude from the apparatus main body 500A of the copying machine, and A4, B5, letter size (or smaller size sheets) having a high user frequency can be stacked as they are. ing.

  On the other hand, the stack trays 421 and 422 can pull out the sub-tray 421a stored inside the stack trays 421 and 422 as necessary when large sheets such as A3, B4, and legal are stacked. ing. Further, the stack trays 421 and 422 have other sub-trays 421b slidable on the sub-tray 421a, and two sub-trays 421a and 421b are provided according to the size of the sheet as shown in FIG. It can be pulled out. For this reason, the stack trays 421 and 422 can stack sheets satisfactorily.

  FIG. 21 is a block diagram illustrating a configuration of a control unit of the sheet processing apparatus 400. The CPU 100 has a ROM 110 therein, and the ROM 110 stores flowcharts corresponding to control procedures shown in FIGS. The CPU 100 controls each unit while reading this program.

  The CPU 100 has a built-in RAM 121 in which work data and input data are stored. The CPU 100 performs control based on data stored in the RAM 121. Furthermore, sensors such as an inlet sensor 403 and a sheet bundle discharge sensor 415 are connected to the input port of the CPU 100. Further, motors and solenoids such as a conveyance motor 431, an offset motor 432, a sheet bundle discharge motor 430, a stack tray lifting motor 530, a pickup solenoid 433, and a clamp solenoid 434 are connected to the output port of the CPU 100. The CPU 100 controls loads such as various motors and solenoids connected to the output port according to a program stored in the ROM 110 based on the state of these sensors.

  In addition, the CPU 100 includes a serial interface unit (I / O) 130, exchanges control data with the control unit 140 of the apparatus main body 500 </ b> A of the copying machine, and via the serial interface unit (I / O) 130. Each unit is controlled based on control data sent from the control unit 140 of the copying machine main body 500A.

  Since the copying machine main body 500A knows the size of the sheet discharged from the sheet discharge unit 208, for example, the CPU 100 of the sheet processing apparatus 400 formed of a microcomputer system controls the control unit 140 of the copying machine main body 500A. By serial communication with the processing tray 410, the size of the sheets stacked on the processing tray 410 can be grasped.

  Therefore, each time the sheet S is discharged from the copying machine main body 500A, the CPU 100 of the sheet processing apparatus 400 grasps the size of the sheet S and controls the offset motor 432, thereby moving the offset roller 407 in the width direction. Can be controlled so as to have a movement amount corresponding to the sheet size. As a result, the offset roller 407 moves by an amount corresponding to the size of the sheet S discharged on the processing tray 410, and the side portion of the sheet can be reliably brought into contact with the width direction positioning wall 416.

  In this embodiment, since the sheet bundle stacked on the stack tray 421 constitutes a part of the processing tray 410, when the sheet bundle SA is discharged from the processing tray 410, the stack tray 421 is discharged. Is lowered by the stack tray lifting / lowering motor 530 (see FIG. 14) until the uppermost surface of the stacked sheet bundle substantially coincides with the processing tray 410.

  Next, FIG. 1 to FIG. 20, FIG. 24, FIG. 25, the block diagram showing the configuration of the control unit of the sheet processing apparatus 400 shown in FIG. 21, and the sheet processing apparatus 400 shown in FIG. 22, FIG. The operation of the sheet processing apparatus 400 will be described on the basis of a flowchart for explaining the operation.

  First, when an image forming operation is started by the copying machine main body 500A, the CPU 100 (see FIG. 21) of the sheet processing apparatus 400 checks whether a sheet discharge signal is received from the copying machine main body 500A. (S100). If a sheet discharge signal is received (YES in S100), the pickup solenoid 433 is turned on (S110), and the offset roller 407 supported by the offset roller holder 406 is pulled up.

  Next, the CPU 100 turns on the conveyance motor 431 (S120) so that the conveyance roller 405 installed in the middle of the sheet discharge path can convey the sheet in the same direction as the sheet discharge direction of the copying machine main body 500A. To do. Here, the entrance sensor 403 is turned on at the leading end of the first sheet (YES in S130), and reaches the conveying roller 405. When the sheet is separated from the sheet discharge unit 208 (see FIG. 1) of the copying machine main body 500A by the conveying roller 405 (YES in S140), the sheet is transferred to the sheet processing apparatus.

  Next, when the CPU 100 conveys the sheet to the processing tray 410 by the conveyance roller 405 and receives an OFF signal from the inlet sensor 403 through which the rear end of the sheet passes through the inlet sensor 403, the CPU 100 turns off the pickup solenoid 433 (S150). The offset roller 407 is landed on the sheet by its own weight. Thereafter, as shown in FIG. 5A, the CPU 100 causes the offset roller 407 to convey the sheet S to a predetermined position (S160). Then, when the sheet S is conveyed to a predetermined position (YES in S160), the CPU 100 stops the rotation of the conveyance motor 431 (S170) and stops the conveyance of the sheet S.

  Next, when the rotation of the offset roller 407 stops, the CPU 100 turns on the clamp solenoid 434 (S180), and as shown in FIG. 5B, the sheet installed in the vicinity of the sheet trailing edge stopper 411. The clamp member 412 is opened. Thereafter, the CPU 100 rotates the conveyance motor 431 in the direction opposite to the conveyance direction, pulls back the sheet S by the offset roller 407 (S190), and abuts the sheet trailing edge against the sheet 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 occurs when the sheet S is fed from the copying machine main body 500A. Is controlled by the CPU 100 so that it can be transported slightly more than the distance from the point of stopping and switching back to the sheet trailing edge stopper 411. That is, the CPU 100 reverses the offset roller 407 for a predetermined time even after the sheet S has been conveyed by a distance that causes the sheet S to contact the sheet trailing edge stopper 411.

  Thereby, the sheet S can be reliably brought into contact with the sheet trailing edge stopper 411. When the sheet S is in contact with the sheet trailing edge stopper 411 while being reversely rotated for a predetermined time as described above, the offset roller 407 is idled (slip) on the sheet.

  Next, the CPU 100 checks the sheet size to be discharged based on the size information from the apparatus main body 500A of the copying machine (S200), and discharges the offset movement amount according to the size of the discharged sheet S, that is, discharged onto the processing tray 410. The movement distance in the width direction of the sheet S required to press the sheet S against the width direction positioning wall 416 is calculated (S210).

  Then, the CPU 100 causes the offset roller 407 to be offset by the offset motor 432 as shown in FIG. 5C to the width direction positioning wall 416 via the offset pinion 516 (see FIG. 4) and the offset rack 515 (S220). . Here, when the offset roller 407 moves, the sheet S in contact with the offset roller 407 moves together with the offset roller 407 toward the width direction positioning wall 416 by the frictional force of the offset roller 407. At this time, the sheet clamp member 412 is opened as shown in FIG. 7B so as not to be a load of movement of the sheet S.

  Next, the offset roller 407 abuts the sheet S against the width-direction positioning wall 416, and then moves and stops slightly while sliding on the sheet S. Thereafter, the CPU 100 reversely reverses the offset roller 407 and pulls back the sheet S in order to correct misalignment of the trailing edge of the sheet caused by the offset movement of the sheet (S230). As a result, the rear end of the first sheet S is realigned, and the sheet alignment is completed.

  Next, when the alignment of the first sheet S is completed in this way, the CPU 100 turns on the pickup solenoid 433 (S240) and raises the offset roller 407 as shown in FIG. 6A. Thereafter, the clamp solenoid 434 is turned off (S250). As a result, the sheet clamp member 412 is closed as shown in FIG. 6B, and the aligned sheet S is held and held by the sheet clamp member 412. As a result, it is possible to prevent the sheet S discharged first from being conveyed to the downstream side in the sheet conveying direction by the subsequent sheet discharged next.

  Next, as shown in FIG. 6B, the offset roller 407 is returned to the home position by the offset motor 432 via the offset pinion 516 (see FIG. 4) and the offset rack 515 while being lifted. (S260).

  The CPU 100 checks whether or not the sheet S accommodated on the processing tray 410 is the last sheet corresponding to the last page of the copied document (S270), and based on the information sent from the copying machine main body 500A. If it is determined that the sheet S is not the final sheet S (NO in S270), the process returns to S100, and a sheet discharge signal sent from the apparatus main body 500A of the copier is received, and the final sheet S is transferred to the processing tray 410. The above-described flow of loading is repeated.

  Thereby, the CPU 100 of the sheet processing apparatus 400 grasps the size of the sheet S every time the sheet S is discharged from the apparatus main body 500A of the copying machine, and calculates an offset movement amount suitable for the sheet S. Based on the offset movement amount, the offset roller 407 is moved to align the side edge of the sheet with the width direction positioning wall 416.

  If the CPU 100 determines that the sheet is the final sheet (YES in S270), a sheet bundle corresponding to the copy document is formed on the processing tray 410. Next, is the stapling process selected? If it is selected (S280), if it is selected (YES in S280), the stapler unit 420 is driven and the stapling process shown in FIG. 24 is executed (S290).

  When the stapling process is not selected (NO in S280) or when the stapling process is completed, as shown in FIG. 9, the CPU 100 moves the sheet bundle discharging member 413 that has gripped the sheet bundle SA by the sheet clamp member 412. The sheet bundle discharge motor 430 is advanced toward the stack trays 421 and 422 to discharge the sheet bundle SA (S300).

  Next, the CPU 100 performs the lowering process of the stack tray 421 in accordance with the discharge operation of the sheet bundle SA (S310), and then returns the sheet bundle discharge member 413 to the home position (S320). Further, after that, the CPU 100 performs the raising process of the stack tray 421 (S321), and stops the raising of the stack tray 421 when receiving the ON signal of the sheet surface detection sensor 573 (S322). The CPU 100 stops the conveyance motor 431 in order to stop the rotation of the conveyance roller 405 and the offset roller 407 (S330), and turns off the pickup solenoid 433 (S340), thereby lowering the offset roller 407 and finishing the series of processes.

  The sheet processing apparatus 400 according to the present embodiment starts from the point at which the rotation amount of the offset roller 407 when the trailing edge of the sheet abuts against the trailing edge stopper 411 is switched back by stopping the conveyance of the sheet S. Since the rotation amount is such that it can be transported slightly more than the distance up to 411, in other words, even after the sheet S is transported by the distance at which the sheet S contacts the sheet trailing edge stopper 411 by the reverse rotation of the offset roller 407, the offset roller 407 Therefore, the sheet S can be reliably brought into contact with the sheet trailing edge stopper 411.

  The sheet processing apparatus 400 of this embodiment can align the trailing ends of the sheets S stably with a simple configuration that does not require many members. Further, since the sheet is not discharged so as to be skipped, the sheet can be stably conveyed with little fluctuation.

  In the staple processing mode, the offset roller 407 moves the sheet in the width direction and abuts against the positioning wall 416. However, if the offset roller 407 is not in the staple processing mode (the sheet is not bound), the sheet is not sorted. Alternatively, it may be discharged as it is.

  The stapler unit 420 is a fixed type and is disposed in the vicinity of the width direction positioning wall 416. However, the stapler unit 420 is not limited to this, and is movable so that it can move in the sheet conveying direction or the width direction. Also good. When the stapler unit 420 is made movable in this way, the stapler unit 420 can perform a stapling process for binding different portions or a plurality of locations in the sheet conveyance direction or width direction of the sheet bundle SA.

  Further, in the sheet processing apparatus of the present embodiment, the offset roller 407 is used to align the trailing edge and the side edge of the sheet. However, not the roller member but the member itself moves in the sheet conveyance direction to move the sheet. The same effect can be obtained by using the sheet conveying direction moving means for conveying and the sheet orthogonal direction moving means for moving the sheet in the width direction by moving in the direction orthogonal to the sheet conveying direction (width direction).

  Furthermore, the sheet processing apparatus according to the present embodiment stores a program corresponding to the control procedure shown in the flowcharts of FIGS. 22 and 23 in the ROM 110 and performs control while the CPU 100 reads the program. The same effect can be obtained even if the processing is performed by hardware.

  In the above description, the case where the CPU 100 of the sheet processing apparatus 400 performs the raising / lowering control of the stack trays 421 and 422 and the stapling operation control has been described. However, the present invention is not limited to this and is not limited to this. You may make it carry out by the control part 140 provided in the apparatus main body.

1 is a schematic front sectional view of an image forming apparatus including a sheet processing apparatus according to an embodiment of the present invention. It is a schematic front sectional view of the sheet processing apparatus shown in FIG. It is a figure which shows a mode that a sheet | seat is discharged on the processing tray of the sheet processing apparatus shown in FIG. FIG. 2 is a schematic perspective view of an offset roller and a conveyance roller driving mechanism of the sheet processing apparatus shown in FIG. 1. It is a figure for demonstrating operation | movement of the offset roller shown in FIG. 2, and the motion of a sheet | seat accompanying it. (A) is a figure of the state which has conveyed the sheet | seat discharged | emitted by the processing sheet once to the downstream side. (B) is a diagram showing a state where the sheet is conveyed back to the upstream side following (a). (C) is a figure of the state which has moved the sheet | seat to the width direction following (b). FIG. 6 is a diagram for explaining the operation following FIG. 5. (A) is a figure of the state which separated the offset roller from the sheet | seat following Fig.5 (a). (B) is the figure which returned the offset roller to the initial position following (a). It is a figure when a sheet clamp member has not pinched the sheet. (A) is a figure of the state which the sheet | seat contact | abutted to the rear-end stopper. (B) is a figure of the state which the sheet | seat contact | abutted to the width direction alignment positioning wall. FIG. 3 is a diagram for explaining a drive mechanism for a sheet bundle discharge member of the sheet processing apparatus shown in FIG. 2. (A) is a figure which has a sheet clamp member in a stand-by position. FIG. 6B is a diagram in which the sheet clamp member has moved to a position where the sheet bundle is discharged. FIG. 10 is a diagram for explaining an operation in which a sheet bundle discharge member discharges a sheet bundle to a stack tray. It is a figure for demonstrating the drive mechanism of the sheet clamp member of the sheet processing apparatus shown in FIG. It is a figure for demonstrating the drive mechanism of the pressing member of the sheet processing apparatus shown in FIG. (A) It is a figure when a pressing member exists in the position which presses a sheet | seat. (B) It is a figure when the pressing member exists in the position which is not pressing the sheet | seat. FIG. 3 is a diagram for explaining movements of a pressing member, a sheet surface detection flag, and a stack tray of the sheet processing apparatus illustrated in FIG. 2. (A) is a figure when the stack tray in which the sheet | seat is not stacked | stacked exists in a raise position. FIG. 5B is a diagram when the stack tray on which no sheets are stacked is in the lowered position. FIG. 3 is a diagram for explaining movements of a pressing member, a sheet surface detection flag, and a stack tray of the sheet processing apparatus illustrated in FIG. 2. (A) is a figure of the state in which the pressing member is pressing the sheet | seat loaded on the stack tray. FIG. 6B is a diagram illustrating a state where the sheet surface detection flag is detecting the sheets stacked on the stack tray. It is a figure of the raising / lowering apparatus which raises / lowers the stack tray of the sheet processing apparatus shown in FIG. FIG. 3 is a diagram for explaining movements of a stack tray (lower bin), a stack tray (upper bin), and a shutter of the sheet processing apparatus shown in FIG. 2. (A) The stack tray (lower bin) is in a position where sheets can be received, and the stack tray (upper bin) is retracted upward. (B) is a figure of the state which the stack tray (lower bin) fell from the state shown to (a). FIG. 3 is a diagram for explaining a shutter driving mechanism of the sheet processing apparatus shown in FIG. 2. (A) is a figure which shows the state which the shutter raised. (B) is a figure which shows the state which the shutter lowered | hung. FIG. 3 is a diagram for explaining movements of a stack tray (lower bin), a stack tray (upper bin), and a shutter of the sheet processing apparatus shown in FIG. 2. (A) is a figure showing the state where a shutter is closed. (B) is a diagram showing a state in which the stack tray (upper bin) is lowered with the shutter closed. FIG. 3 is a diagram for explaining movements of a stack tray (lower bin), a stack tray (upper bin), and a shutter of the sheet processing apparatus shown in FIG. 2. (A) is a figure which shows the state which the shutter opened from the state of FIG.17 (b). (B) is a figure which shows the state which closed the shutter following (a). FIG. 3 is a diagram for explaining movements of a stack tray (lower bin), a stack tray (upper bin), and a shutter of the sheet processing apparatus shown in FIG. 2. (A) is a figure which shows the state which closed the shutter and raised the stack tray (upper bin). FIG. 6B is a diagram illustrating a state where sheets can be stacked on the stack tray (lower bin). FIG. 3 is a diagram for explaining a configuration of a stack tray (lower bin) and a stack tray (upper bin) of the sheet processing apparatus shown in FIG. 2. (A) is a figure of the state in which the subtray is accommodated in the stack tray. (B) is a figure which shows the state by which the subtray was pulled out from the stack tray. FIG. 3 is a block diagram illustrating a configuration of a control unit of the sheet processing apparatus illustrated in FIG. 2. FIG. 3 is a flowchart for explaining a part of the sheet processing operation of the sheet processing apparatus shown in FIG. 2. FIG. 23 is a flowchart following FIG. 22. FIG. 3 is a diagram illustrating a state where a sheet offset by an offset roller illustrated in FIG. 2 is stapled. It is a figure of the other raising / lowering apparatus which raises / lowers the stack tray of the sheet processing apparatus shown in FIG.

Explanation of symbols

S sheet SA sheet bundle SP space SP1 formed in the side of the image forming apparatus main body sheet stacking space SPU space 100 above the sheet discharge port CPU (control means)
140 Control Unit 200 of Copier Main Body Printer Unit (Image Forming Unit)
300 automatic document feeder 400 sheet processing device 403 entrance sensor (sheet detecting means)
410 processing tray 412 sheet clamp member 420 stapler unit 421 stack tray (lower bin) (sheet stacking means)
421A Holding member (sheet pressing means)
421Aa Shaft 421Aaa Recess 422 Stack tray (upper bin) (sheet stacking means)
430 Sheet bundle discharging motor 431 Conveying motor 432 Offset motor 432a Offset motor gear 433 Pickup solenoid 434 Clamp solenoid 507 Lifting device (lifting means)
508 Holding member driving device (moving means)
509 Lifting device (lifting means)
500 Copying machine (image forming device)
500A Main Body 530 of Copying Machine (Image Forming Apparatus) Stack Tray Lift Motor 570 Sheet Surface Detection Flag (Height Detection Unit)
573 Sheet surface detection sensor (height detection means)

Claims (6)

Sheet stacking means for stacking sheets;
Elevating means for elevating the sheet stacking means;
Sheet detecting means for detecting discharge of the sheet to the sheet stacking means;
Sheet pressing means for pressing a sheet on the sheet stacking means;
Moving means for moving the sheet pressing means between a pressing position where the sheet pressing means presses the sheet and a retracted position where the sheet pressing means retracts from the pressing position;
After the sheet detection is detected by the sheet detecting means, the lifting / lowering means is controlled to lower the sheet stacking means by a predetermined amount, and the moving means is controlled to move the sheet pressing means from the pressing position to the retracted position. And then moving the sheet pressing unit from the retracted position to the pressing position to contact the upper surface of the sheet, and then controlling the lifting unit to control the sheet stacking. Control means for starting the ascent of the means;
A sheet processing apparatus comprising:   2. A height detecting means for detecting whether or not the sheet contact position of the sheet pressing means has become a height equal to or higher than a set value when the sheet stacking means is raised. The sheet processing apparatus according to the description.   3. The sheet processing apparatus according to claim 2, wherein the sheet pressing unit and the height detection unit operate at the same time depending on the state of the sheet discharged to the sheet stacking unit.   The sheet processing apparatus according to claim 2, wherein the height detection unit is disposed at a position where the bulge of the sheet due to post-processing applied to the upstream end corner portion of the sheet can be detected. Image forming means for forming an image on a sheet;
A sheet processing apparatus for processing a sheet on which an image is formed by the image forming unit,
The image forming apparatus, wherein the sheet processing apparatus is the sheet processing apparatus according to claim 1. Image forming means for forming an image on a sheet;
Sheet stacking means for stacking sheets;
Elevating means for elevating the sheet stacking means;
Sheet detecting means for detecting discharge of the sheet to the sheet stacking means;
Sheet pressing means for pressing a sheet on the sheet stacking means;
Moving means for moving the sheet pressing means between a pressing position where the sheet pressing means presses the sheet and a retracted position where the sheet pressing means retracts from the pressing position;
After the sheet detection is detected by the sheet detecting means, the lifting / lowering means is controlled to lower the sheet stacking means by a predetermined amount, and the moving means is controlled to move the sheet pressing means from the pressing position to the retracted position. And then moving the sheet pressing unit from the retracted position to the pressing position to contact the upper surface of the sheet, and then controlling the lifting unit to control the sheet stacking. Control means for starting the ascent of the means;
An image forming apparatus comprising:

Images