JP5665577B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus, and in particular, when a sheet is processed, a plurality of sheets of the next job are overlapped and waited in a state where the upper sheet precedes the lower sheet in the discharge direction. It relates to what I did.

  Conventionally, in an image forming apparatus such as a copying machine, a laser beam printer, a facsimile machine, or a combination of these, a stack process for aligning and discharging a sheet bundle on which an image is formed, and a sheet process for performing a binding process on the sheet bundle Some are equipped with devices. This sheet processing apparatus, for example, when binding a sheet bundle, forms a sheet bundle by stacking a plurality of sheets on an intermediate processing tray provided in the apparatus, and binding means for this sheet bundle, Perform binding processing.

  In such a sheet processing apparatus, when the binding process is performed on the sheet bundle, first, the sheets are discharged one by one to the intermediate processing tray. Next, the position of the upstream end in the sheet discharge direction is aligned by moving the sheet in the direction opposite to the discharge direction and bringing the upstream end in the sheet discharge direction into contact with the rear end regulating plate. Thereafter, the side end positions in the width direction orthogonal to the sheet discharge direction are aligned by a jog operation of the alignment plate to form a sheet bundle in which the upstream end and the side end positions in the discharge direction are aligned. Thereafter, such alignment processing is performed on a predetermined number of sheets that are sequentially discharged, and the binding unit is moved to the binding position to perform binding processing on the aligned sheet bundle.

  In an image forming apparatus having such a conventional sheet processing apparatus, the first sheet of the next job is placed in the main body of the image forming apparatus during the binding process in order to secure processing time during the binding process. It is made to stay and at least the 2nd sheet is piled up on this sheet. After at least the second sheet is overlaid on the first sheet in this way, when the previous job is completed, an operation is performed to discharge the plurality of sheets to the intermediate processing tray by the discharge roller. At this time, the first sheet is conveyed in a state delayed from the second sheet.

  By the way, in the conventional sheet processing apparatus, after a plurality of sheets are stacked and discharged to the intermediate processing tray, the sheet is conveyed toward the rear end regulating plate using, for example, a knurled belt and is used as a stopper (rear end regulating plate). There is one that is made to contact (see Patent Document 1). Here, in such a sheet processing apparatus, when a plurality of sheets, for example, two sheets are stacked and discharged to the intermediate processing tray, the upper second sheet is set to the lower one by the discharge roller pair and the knurled belt. The paper is discharged in a state preceding the discharge direction with respect to the first sheet.

  Then, when the sensor detects that the first of the two sheets has passed through the knurled belt, the discharge roller pair is temporarily stopped, and then the discharge roller pair is rotated in the reverse direction. The sheets are conveyed toward the stopper while being overlapped. Thereafter, by separating the pair of discharge rollers, the first and second sheets are conveyed toward the stopper by the knurled belt, and the trailing edges of the sheets are aligned.

  When the two sheets are conveyed toward the stopper in this way, the second sheet is in a state preceding the discharge direction with respect to the first sheet. Will hit the stopper, and the second sheet will then hit the stopper. A plurality of sheets can be reliably aligned by abutting the sheets against the stopper in this order.

JP-A-10-194582

  By the way, in such a conventional sheet processing apparatus, the friction coefficient between the sheets conveyed toward the stopper in the overlapped state may be lower than the friction coefficient between the intermediate processing tray and the sheet. In this case, the upper second sheet precedes the lower first sheet in the direction toward the stopper. When the second sheet is in the preceding state, the knurled belt is in contact with the second sheet from above, but the second sheet can abut against the stopper. In some cases, the first sheet cannot be brought into contact with the stopper. In this case, alignment of the lower first sheet becomes insufficient, and there is a possibility that alignment failure of the first sheet may occur.

  Therefore, in order to ensure the consistency of the lower sheet, it is necessary that the upper sheet hits the stopper after the lower sheet hits the stopper. For this purpose, the friction coefficient between the sheets needs to be higher than the friction coefficient between the intermediate processing tray and the sheet.

  As described above, in the case of the conventional sheet processing apparatus, the sheet consistency depends on the relationship between the friction coefficient between sheets and the friction coefficient between the intermediate processing tray and the sheet. For this reason, in order to ensure the consistency of the lower sheets, it is necessary to make the friction coefficient between the sheets higher than the friction coefficient between the intermediate processing tray and the sheet. However, when the alignment depends on the friction coefficient in this way, it becomes impossible to perform stable alignment due to a minute change in the type of sheet or the surface state of the intermediate processing tray, and alignment failure occurs. There is a fear.

  Therefore, the present invention has been made in view of such a current situation, and a sheet processing apparatus and an image that can improve sheet consistency regardless of a minute change in the type of sheet or the surface state of the intermediate processing tray. An object of the present invention is to provide a forming apparatus.

  The present invention provides a sheet stacking unit for stacking sheets to be processed, an alignment reference member for positioning the sheet discharged in the sheet stacking unit in contact with one end in the sheet discharge direction, and the alignment A processing unit that processes a sheet positioned in the sheet discharge direction by a reference member; a standby unit that waits in a state where the sheets conveyed while the sheets are processed by the processing unit; and the standby unit A sheet stacking unit that stacks and discharges the sheet stacking unit to the sheet stacking unit in a state where one end in the sheet discharging direction of the lower sheet is shifted closer to the alignment reference member than one end of the upper sheet in the sheet discharging direction from the unit; Is provided so as to be movable up and down, and when the sheets are stacked and discharged on the sheet stacking unit, the sheets are lowered and come into contact with the respective sheets of the stacked sheets. A plurality of sheet conveying units that convey and abut against the alignment reference member, and among the plurality of sheet conveying units, a lower sheet is used as the alignment reference member by a first sheet conveying unit that abuts a lower sheet. The upper sheet conveyed by the second sheet conveying unit that comes into contact with the upper sheet after the abutment reaches the first sheet conveying unit.

  As in the present invention, after the lower sheet is abutted against the alignment reference member by the first sheet conveying unit, the upper sheet reaches the first sheet conveying unit, so that the type of sheet and the intermediate processing tray Regardless of a minute change in the surface state, the sheet alignment can be improved.

1 is a diagram illustrating a configuration of an image forming apparatus including a sheet processing apparatus according to a first embodiment of the present invention. The figure explaining the structure of the finisher which is the said sheet processing apparatus. FIG. 3 is a first diagram illustrating a buffer mechanism provided in the finisher. The 2nd figure explaining the said buffer mechanism. FIG. 3 is a control block diagram of the finisher. FIG. 3 is a first diagram illustrating a binding operation of the finisher. The figure which shows the state of the 1st and 2nd sheet | seat when the rear-end alignment part provided in the said finisher descend | falls. The 2nd figure explaining the binding operation | movement of the said finisher. The figure explaining the structure of the sheet processing apparatus which concerns on the 2nd Embodiment of this invention. The figure explaining the structure of the sheet processing apparatus which concerns on the 3rd Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a copier that is an example of an image forming apparatus including a sheet processing apparatus according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 100 denotes a copying machine, and 100A denotes a copying machine main body. On the upper surface of the copying machine main body 100A, an image comprising a scanner unit 201 having a CCD (not shown) for reading a document image placed on the document table glass 206 and an automatic document feeder (hereinafter referred to as ADF) 202 is provided. A reading unit 200 is provided.

  The ADF 202 can be opened and closed rearward around a hinge (not shown) at the rear of the apparatus, and is opened and closed when a document is placed on the document table glass 206. The scanner unit 201 includes a movable optical carriage 207, and reads information described in a document. The scanner unit 201 reads the document description information while the optical carriage 207 scans the document placed on the document table glass 206 in the horizontal direction, and photoelectrically converts the document information using the CCD. Further, when reading the document conveyed by the ADF 202, the optical carriage 207 stops at the document reading position 205, and reads the description information of the document being conveyed at the document reading position 205.

  The copying machine main body 100A is provided with an image forming unit 100B having a photosensitive drum 108 and the like, and the sheet S stacked and stored in the paper feed cassette 102 is placed in the image forming unit 100B at the lower part of the copying machine main body 100A. A sheet feeding device 100 </ b> C for feeding is provided.

  Here, the image forming unit 100B includes a process cartridge 107 including a photosensitive drum 108, a charger (not shown), a developing sleeve, a cleaning unit, and the like. Further, a laser scanner 109 is provided as an exposure unit that exposes the surface of the photosensitive drum 108 to form an electrostatic latent image on the photosensitive drum 108.

  Further, the copying machine main body 100A is in contact with the photosensitive drum 108, the transfer roller 108a constituting the transfer portion together with the photosensitive drum 108, the fixing device 110 for fixing the toner image transferred by the transfer portion to the sheet S, and the like. It has. Further, a finisher 300, which is a sheet processing apparatus for processing an image-formed sheet discharged from the copier main body 100A, is connected to the copier main body 100A.

  In FIG. 1, reference numeral 115 denotes a first sheet conveyance path through which a sheet passes when the sheets are conveyed to the finisher 300 one by one. Reference numeral 114 denotes a second sheet conveyance path for stacking the second page of the subsequent job in a state advanced by a predetermined amount from the first page in the conveyance direction during processing of the preceding job. Reference numeral 113 denotes a switching member that switches the path of the conveyed sheet to the first sheet conveyance path 115 or the second sheet conveyance path 114, and 112 is provided between the fixing device 110 and the fixing discharge conveyance roller 111 to detect the sheet. This is a paper discharge sensor.

  In this copying machine 100, when forming an image on a sheet, the originals stacked on the stacking tray 203 are fed one by one by the feeding roller 204 of the ADF 202, and the optical carriage 207 of the scanner unit 201 is moved by the optical carriage 207. The stopped document reading position 205 is passed. At this time, an image of a document (not shown) is read by the optical carriage 207, and laser light corresponding to the read image information is output from the laser scanner 109. The output laser light is reflected by a mirror (not shown) and irradiated onto the surface of the photosensitive drum. Here, the surface of the photosensitive drum is charged in advance by a primary charger. Thus, when the laser beam is irradiated, an electrostatic latent image is formed on the surface of the photosensitive drum, and a toner image is formed on the photosensitive drum by developing the electrostatic latent image with a developing device. .

  Thereafter, when a paper feed signal is output, the sheet S is sent out from a paper feed cassette 102 detachably provided in the copying machine main body 100A by a paper feed roller 104 provided in the sheet feeding apparatus 100C. Thereafter, the sheets S are separated one by one by a separation roller 105 and conveyed along a conveyance guide 106 to a transfer unit constituted by a photosensitive drum 108 and a transfer roller 108a, and a toner image on the photosensitive drum is transferred. The Further, the sheet onto which the toner image has been transferred is conveyed to the fixing device 110, and the toner image is fixed by applying heat and pressure in the fixing device 110. Thereafter, the sheet S is discharged from the copying machine main body 100 </ b> A by the discharge roller pair 119 and conveyed to the finisher 300.

  Here, in the present embodiment, when the sheets S are conveyed to the finisher 300 one by one, the sheets are conveyed to the first sheet conveying path 115 by the fixing discharge conveyance roller 111 through the fixing device 110. Thereafter, the sheet is conveyed to the discharge roller pair 119 by the first conveyance roller 117 provided in the first sheet conveyance path 115. Then, the paper is discharged from the copying machine main body 100 </ b> A toward the finisher 300 by the discharge roller pair 119.

  As will be described later, after the image is fixed during the processing of the preceding job, the sheet of the first page of the subsequent job (hereinafter referred to as the first sheet) is guided to the first sheet conveyance path 115, Stop. Further, the second sheet of the subsequent job (hereinafter referred to as a second sheet) is conveyed to the second sheet conveyance path 114 by switching the switching member 113. Thereby, two sheets can be buffered (standby) using the second sheet conveyance path 114 and the first sheet conveyance path 115. Further, in the present embodiment, when the two sheets are made to wait in the first and second sheet transport paths 114 and 115 during the processing of the preceding job in this way, the second sheet is ejected more than the first sheet. It is made to overlap in the state which advanced predetermined amount toward (conveyance direction).

  The finisher 300 sequentially takes in the sheets discharged from the copying machine main body 100A, aligns the plurality of taken-in sheets, and bundles them into one bundle. Further, a stapling process (binding process) for binding the rear end (upstream end in the sheet discharge direction) of the bundled sheet bundle is performed.

  As shown in FIG. 2, the finisher 300 includes a first processing conveyance path 301, a first conveyance roller pair 302, an intermediate stacking unit 303 as a sheet stacking unit, a first discharge roller 304, a first stacking tray 305, and a rear end alignment. Section 306, side end alignment section 307, and full load detection flag 308. Note that a stapler (not shown) that is a processing unit that performs stapling processing is provided at one end of the intermediate stacking unit 303. An alignment reference wall X, which is an alignment reference member that contacts the upstream end of the sheet discharge direction and aligns the position of the upstream end of the sheet discharge direction, is provided on the upstream side of the intermediate stacking unit 303 in the sheet discharge direction. .

  Further, the side edge aligning portion 307 aligns the side end positions in the width direction orthogonal to the sheet discharge direction, aligns the side end positions of the sheets, and supports the sheet from below when aligning. It has a pair of alignment members 307a movable in the direction. Then, when processing the sheet bundle, the alignment member 307a is moved in the width direction to move the sheet bundle to a position where the sheet is supported, thereby aligning the side edge positions in the width direction of the sheet bundle. After processing the sheet bundle, the alignment member 307a is moved to a position where the support of the sheet is released, and the sheet bundle is dropped onto the first stacking tray 305.

  The trailing edge aligning unit 306 conveys the sheet in the direction of the alignment reference wall X, that is, the direction opposite to the sheet discharge direction, and abuts the upstream end of the sheet discharge direction on the alignment reference wall X to This is for aligning the position. Here, as shown in FIGS. 6 and 8 described later, the rear end alignment portion 306 is provided above and below the intermediate stacking portion 303 so as to be moved up and down. The trailing edge aligning unit 306 is a plurality of first and first sheet conveying units that come into contact with the first sheet S1 and the second sheet S2 discharged to the intermediate stacking unit 303 when lowered. Two alignment rollers 306a and 306b are provided. The finisher 300 further includes a second transport path 316, a third transport path 310, a second switching member 311, a second stacking tray 312, a third stacking tray 313, a second discharge roller 314, and a third discharge roller 315. .

  In the finisher 300 having such a configuration, for example, when the sheets are discharged to the first stacking tray 305, the first switching member 309 is held at the upper position in the drawing. Further, the alignment member 307a of the side end alignment portion 307 moves so as to have a wider interval than the lateral width of the sheet. Thus, the sheet conveyed by the discharge roller pair 119 of the copying machine main body 100A is discharged to the first stacking tray 305 by the first discharge roller 304 through the first processing conveyance path 301.

  Further, when the binding process is performed on the sheet, the first switching member 309 is held at the upper position in the drawing, and the alignment member 307a of the side edge alignment portion 307 moves to a position that supports the side edge of the sheet. At the same time, the first discharge roller 304 is separated. Thus, the sheet conveyed by the discharge roller pair 119 is first supported by the intermediate stacking unit 303 and the side edge aligning unit 307. Thereafter, the trailing edge aligning portion 306 descends, and the trailing edge aligning portion 306 and the side edge aligning portion 307 align the upstream end (rear end) and the side end position of the sheet in the sheet discharge direction. After the alignment of a predetermined number of sheets is completed, a binding process is performed on the sheet bundle by a stapler. Thereafter, the first discharge roller 304 is nipped and the sheet is not supported by the side edge aligning unit 307. The bundle is discharged to the first stacking tray 305.

  Further, when the sheets are discharged to the second stacking tray 312, the first switching member 309 is held at the lower position in the drawing, and the second switching member 311 is held at the upper position in the drawing. As a result, the sheet passes through the second conveyance path 316 and is discharged onto the second stacking tray 312 by the second discharge roller 314. Further, when the sheets are discharged to the third stacking tray 313, the first switching member 309 is held at the lower position in the drawing, and the second switching member 311 is held at the lower position in the drawing. Accordingly, the sheet is discharged onto the third stacking tray 313 by the third discharge roller 315 through the third conveyance path 310.

  By the way, in the present embodiment, during the processing of the preceding job, the sheet of the succeeding job is made to stand by inside the copying machine main body 100A. Next, the buffer mechanism constituting the sheet standby unit according to the present embodiment will be described with reference to FIGS.

  When the finisher 300 is processing the preceding job, the first sheet S1 of the next job is guided to the first sheet conveyance path 115 by the switching member 113 as shown in FIG. Next, the first sheet S1 is conveyed by the fixing discharge conveyance roller 111, and after the trailing edge of the first sheet S1 passes through the trailing edge sensor 112, the driving of the first conveyance roller 117 is turned off at a predetermined timing. As a result, the first sheet S1 stops at a predetermined position shown in FIG. At this time, the second sheet S2 is guided to the second sheet conveyance path 114 by the switching member 113.

  Thereafter, as shown in FIG. 4A, the second sheet S <b> 2 is transported by the second transport roller 116, and travels to a junction J between the second sheet transport path 114 and the first sheet transport path 115. When a predetermined time elapses after the trailing edge of the second sheet S2 passes through the trailing edge sensor 112, the second sheet S2 precedes the first sheet S1 by a predetermined amount α in the discharge direction (conveyance direction). It becomes a state.

  Then, at the same time as the sheet S2 is advanced by the predetermined amount α, the first transport roller 117 is turned on again, so that the first sheet S1 is transported by the first transport roller 117. Here, since the second sheet S2 is always being conveyed by the second conveying roller 116 at this time, the first sheet S1 as the lower sheet and the second sheet S2 as the upper sheet are thereafter at the same conveying speed. It is conveyed by. As a result, as shown in FIG. 4B, the first sheet S1 and the second sheet S2 are conveyed by the first conveying roller 117 and the second conveying roller 116 while securing a predetermined amount α. Thereafter, the first sheet S1 and the second sheet S2 are discharged from the copying machine main body 100A while being shifted in the transport direction by a discharge roller pair 119 serving as discharge means, and transferred to the finisher 300.

  In this way, during the stapling process of the preceding job, the second sheet S2 is buffered in a state of being advanced by a predetermined amount α in the transport direction from the first sheet S1. That is, it is possible to create a state in which the second sheet S2 precedes the first sheet S1 by a predetermined amount α in the conveyance direction only by switching the driving of the first conveyance roller 117.

  FIG. 5 is a control block diagram of the finisher 300. In FIG. 5, reference numeral 400 denotes a control unit that is provided in the finisher 300 or the copying machine main body 100 </ b> A and controls the finisher 300. The control unit 400 is connected to a rear end sensor 112 and an inlet sensor 401 provided upstream of the first conveying roller pair 302. Further, the control unit 400 includes an elevating unit 410 that moves the rear end aligning unit 306 up and down, an alignment motor 420 that rotates the first and second alignment rollers 306a and 306b provided in the rear end aligning unit 306, and a first discharge roller. A first motor 430 that drives 304 is connected.

  Next, the binding operation of the finisher 300 for the sheet discharged in a state where the second sheet S2 precedes the first sheet S1 by a predetermined amount α in the transport direction will be described.

  When the binding process is performed on the next sheet bundle, as shown in FIG. 6A, the first and second sheets S1 and S2 have the second sheet S2 facing the discharge direction more than the first sheet S1. Then, the sheet is conveyed by the discharge roller pair 119 in a state of being advanced by a predetermined amount α. Thereafter, the first and second sheets S 1 and S 2 are conveyed to the intermediate stacking unit 303 by the first conveying roller pair 302. At this time, the first discharge roller 304 is nipped.

  Next, one end of the first sheet S1 in the sheet discharge direction, in this embodiment, the upstream end in the discharge direction is detected by the entrance sensor 401 provided upstream of the first conveying roller pair 302, and the entrance sensor 401 detects the first sheet S1. The signal is output to the control unit 400. Accordingly, the control unit 400 detects the position of the upstream end of the first sheet S1 in the discharge direction based on this signal. Thereafter, when it is detected that the distance between the upstream end in the discharge direction of the first sheet S1 and the alignment reference wall X is A, the control unit 400 stops driving the first motor 430 and performs the first discharge. The roller 304 is stopped.

  Next, as shown in FIG. 6B, the first discharge roller 304 is separated and the elevating unit 410 is driven to lower the rear end aligning unit 306, so that the first end provided in the rear end aligning unit 306. The second alignment rollers 306a and 306b are simultaneously brought into contact with the first and second sheets S1 and S2. Thereafter, the alignment motor 420 is driven to rotate the first and second alignment rollers 306a and 306b clockwise.

  Thereby, alignment of the discharge direction of the first and second sheets S1, S2 is started. Thereafter, as shown in FIG. 6C, first, the first sheet S1 is first transported by the first alignment roller 306a that is the first sheet transport unit, hits the alignment reference wall X, and the first sheet S1 is discharged. The alignment (positioning) of the upstream end in the direction is completed. When the alignment of the upstream end of the discharge direction of the first sheet S1 is completed, the discharge direction of the second sheet S2 conveyed toward the alignment reference wall X by the second alignment roller 306b that is the second sheet conveyance unit. The upstream end (alignment reference wall side end) does not reach the first alignment roller 306a.

  That is, in the present embodiment, as shown in FIG. 7, the upstream end in the discharge direction of the second sheet S2 does not reach the first alignment roller 306a when the alignment in the discharge direction of the first sheet S1 is completed. In FIG. 7, A is the distance from the alignment reference wall X to the upstream end in the discharge direction of the first sheet S1 when the trailing edge aligning portion 306 is lowered, and B is the distance from the first sheet S1 of the first alignment roller 306a. This is the distance between the contact position and the upstream end of the second sheet S2 in the discharge direction.

  Here, when A> B, before the first sheet S1 hits the alignment reference wall X and the alignment in the discharge direction of the first sheet S1 is completed, the upstream end in the discharge direction of the second sheet S2 is the first alignment. The roller 306a is reached. In this case, since the rear end aligning portion 306 is in contact with the second sheet S2 from above, the second sheet S2 can be aligned. However, when the friction coefficient of the first and second sheets S1 and S2 is lower than the friction coefficient between the intermediate stacking portion 303 and the first sheet S1, the second reference sheet X is aligned with the second reference sheet X than the first sheet S1. It will be in the state preceded with respect to the alignment direction which is a direction which goes to.

  When the second sheet S2 is ahead of the first sheet S1 in the alignment direction as described above, the upstream end of the second sheet S2 in the discharge direction can be aligned. It becomes impossible to return to the alignment reference wall X. As a result, alignment failure of the first sheet S1 occurs. That is, when A> B, the consistency of the first sheet S1 depends on the friction coefficients of the first and second sheets S1, S2 and the friction coefficient between the intermediate stacking portion 303 and the first sheet S1. It will be.

  Therefore, in the present embodiment, the consistency of the first sheet S1 does not depend on the friction coefficient between the first and second sheets S1 and S2 and the friction coefficient between the intermediate stacking unit 303 and the first sheet S1. The shift amount α and the distance A between the first and second sheets S1 and S2 are set. That is, the shift amount (preceding amount) α of the first and second sheets S1 and S2 and the distance A are set so that A <B.

  As a result, even when the first and second alignment rollers 306a and 306b come into contact with the sheet at the same time, when the first sheet S1 hits the alignment reference wall X, the second sheet S2 contacts the first alignment roller 306a. You can prevent it from reaching. As a result, the first sheet S1 can be reliably abutted against the alignment reference wall X.

  Next, when the alignment in the discharge direction of the first sheet S1 is completed as described above, the upstream end in the discharge direction of the second sheet S2 reaches the first alignment roller 306a as shown in FIG. . Then, the second sheet S2 is conveyed until the upstream end in the discharge direction hits the alignment reference wall X, and when the second sheet S2 hits the alignment reference wall X, the alignment in the discharge direction of the second sheet S2 is completed.

  Next, after the alignment in the discharge direction of the first and second sheets S1 and S2 is completed, the side edge of the sheet S1 and S2 is aligned by the side edge alignment portion 307 being pressed. Is done. Then, the alignment between the upstream end and the side end in the discharge direction is repeated for the number of subsequent jobs, and after the predetermined number of alignments are completed, the staple process is performed on the sheet bundle. Next, after such a binding process is performed on the sheet bundle, the first discharge roller 304 is nipped as shown in FIG. Thus, thereafter, as shown in FIG. 8C, the sheet bundle of the subsequent job subjected to the stapling process is conveyed by the first discharge roller 304 and discharged to the first stacking tray 305.

  As described above, in the present embodiment, after the first sheet S1 is abutted against the alignment reference wall X by the first alignment roller 306a, the second sheet S1 reaches the first alignment roller 306a. As a result, the sheets can be abutted against the alignment reference wall X in the order of the first sheet S <b> 1 and the second sheet S <b> 2 regardless of a minute change in the type of sheet or the surface state of the intermediate stacking unit 303. As a result, the sheet alignment can be improved and the occurrence of alignment failure can be prevented.

  In this embodiment, the alignment in the sheet discharge direction has been described. However, the present invention is not limited to this, and the alignment in the width direction can also be handled. Further, although the first alignment roller 306a and the second alignment roller 306b are brought into contact with the first and second sheets S1 and S2 at the same timing, the present invention is not limited to this. That is, if the relationship of A <B is sufficiently established, the timing at which the first alignment roller 306a and the second alignment roller 306b abut on the first and second sheets S1 and S2 may be slightly shifted.

  Next, a second embodiment of the present invention will be described. FIG. 9 is a diagram illustrating the configuration of the sheet processing apparatus according to the present embodiment. 9, the same reference numerals as those in FIG. 6 described above indicate the same or corresponding parts.

  In FIG. 9, reference numeral 317 denotes a rotation member that rotates about the rotation center Y. Reference numeral 323 denotes a first holding member that rotatably holds the first alignment roller 306 a via the first pulley 318, and 324 denotes a second holding member that rotatably holds the second alignment roller 306 b via the second pulley 319. is there. Reference numeral 320 denotes a third pulley that is rotated by the above-described alignment motor. The third pulley 320 rotates the first pulley 318 via the first belt 321 and the second pulley 319 via the second belt 322. Let That is, in this embodiment, the first alignment roller 306a and the second alignment roller 306b are driven by one pulley 319 via the first and second belts 321 and 322.

  The first holding member 323 and the second holding member 324 rotate in the vertical direction with the shaft of the third pulley 320 as a fulcrum, and are supported by a support portion 317a provided on the rotating member 317 from below. Accordingly, when the rotation member 317 is rotated downward, the first holding member 323 and the second holding member 324 are rotated downward by its own weight or an urging member (not shown). Here, the first holding member 323 is longer than the second holding member 324.

  Therefore, when the rotation member 317 is rotated downward, the second sheet S2 as described above at the position where the first alignment roller 306a previously held by the first holding member 323 is close to the alignment reference wall X. The first sheet S1 in a state shifted by the shift amount α. Thereafter, the second alignment roller 306b held by the second holding member 324 contacts the second sheet S2 at a position away from the alignment reference wall X.

  Thus, in the present embodiment, at the time of discharge direction alignment, the timing at which the first alignment roller 306a abuts on the first sheet S1 is earlier than the timing at which the second alignment roller 306b abuts on the second sheet S2. I am doing so. In other words, in the present embodiment, the first alignment roller 306a and the second alignment roller 306b abut on the first and second sheets S1 and S2 by the rotation of the rotation member 317 about the rotation center Y. Timing is controlled.

  Next, the alignment operation of the finisher 300 as the sheet processing apparatus according to the present embodiment will be described. First, as shown in FIG. 9A, the first and second sheets S1, S2 are conveyed to the intermediate stacking unit 303 in a state of being shifted by a predetermined shift amount α. At this time, since the rotating member 317 is in a position for supporting the first holding member 323 and the second holding member 324, the first alignment roller 306a and the second alignment roller 306b do not contact the sheets S1 and S2.

  Next, as shown in FIG. 9B, the first alignment roller 306a comes into contact with the first sheet S1 when the distance between the rear end of the first sheet S1 and the alignment reference wall X becomes A. The rotation member 317 rotates downward. Along with this, the first holding member 323 and the second holding member 324 rotate downward, and the first alignment roller 306a first contacts the first sheet S1, and then the first sheet S1 moves in the alignment direction. Be started. Thereafter, when the rotation member 317 further rotates in the direction of the arrow, as shown in FIG. 9C, the second alignment roller 306b comes into contact with the second sheet S2, and thereafter, the second sheet S2 Movement in the alignment direction is started.

  Here, when the movement of the second sheet S2 is started, the first alignment roller 306a and the second sheet are more than the distance C (<A) from the alignment reference wall X to the upstream end in the discharge direction of the first sheet S1. The shift amount α and the like are set so that the distance D (= distance B) from S2 is larger. The distance D (= B) is set to be larger than the distance A. Thereby, even if the movement of the second sheet S2 by the second alignment roller 306b is started, the second sheet S2 does not reach the first alignment roller 306a when the first sheet S1 hits the alignment reference wall X. Can be. As a result, the first sheet S1 can be reliably abutted against the alignment reference wall X.

  As described above, in the present embodiment, when C (<A) <D (= B) after the first alignment roller 306a descends and comes into contact with the first sheet S1, the second sheet The second alignment roller 306b is lowered so as to come into contact with S2. Then, by setting the timing at which the alignment rollers 306a and 306b come into contact with the sheets S1 and S2 in this way, after the first alignment roller 306a starts the alignment operation of the first sheet S1, the second alignment roller 306b The alignment operation of the two sheets S2 is started.

  Thereby, the second sheet S2 does not precede the alignment direction during the alignment operation with respect to the first sheet S1, and the first sheet S1 can be reliably aligned. As a result, it is possible to reliably prevent the second sheet S2 from leading to the first sheet S1 in the alignment direction without causing alignment failure of the first sheet S1, Reliable alignment in the paper discharge direction is possible.

  Note that, when the alignment of the second sheet S2 is started by causing the first alignment roller 306a to contact the sheet earlier than the second alignment roller 306b as in the present embodiment, the above distance is set. It becomes easier to increase the distance D than C. As a result, it is possible to roughly set the distance A from the alignment reference wall X to the upstream end portion in the discharge direction of the first sheet S1 and the shift amount α of the sheets S1 and S2.

  Next, a third embodiment of the present invention will be described. FIG. 10 is a diagram illustrating the configuration of the sheet processing apparatus according to the present embodiment. 10, the same reference numerals as those in FIG. 6 described above indicate the same or corresponding parts.

  In FIG. 10, reference numeral 340 denotes a driving unit that drives the first alignment roller 306a and the second alignment roller 306a. The drive unit 340 meshes with a first gear 325, a second gear 327, and a second gear 327 that are driving gears driven by an alignment motor, and a third gear 328 that rotates the first alignment roller 306a, and a second alignment. A fourth gear 330 that rotates the roller 306b is provided. Reference numeral 326 denotes a drive transmission belt that transmits the drive of the first gear 325 to the second gear 327, and reference numerals 329a and 329b denote idler gears that transmit the drive of the second gear 327 to the fourth gear 330.

  Here, the sheet conveying speed of the first sheet S1 by the first aligning roller 306a is V1, the sheet conveying speed of the second sheet S2 by the second aligning roller 306b is V2, and the first alignment with the upstream end in the discharge direction of the second sheet S2. Let B be the distance to the roller 306a. The time until the upstream end of the first sheet S1 in the discharge direction reaches the alignment reference wall X, that is, A / V1, until the upstream end of the second sheet S2 in the discharge direction reaches the first alignment roller 306a. This time is shorter than B / V2.

  FIG. 10 shows a state when the first alignment roller 306a and the second alignment roller 306b are in contact with the first and second sheets S1 and S2. In the present embodiment, the timing when the first alignment roller 306a and the second alignment roller 306b contact the first and second sheets S1 and S2 is set to be the same. Further, the sheet conveyance speed V1 of the first alignment roller 306a and the sheet conveyance speed V2 of the second alignment roller 306b are obtained by using the reduction ratio of the third gear 328 and the fourth gear 330, so that A / V1 <B / It is set to be V1.

  Thus, in this embodiment, the sheet conveying speed V1 of the first alignment roller 306a and the sheet conveying speed V2 of the second alignment roller 306b are set so as to satisfy the relationship of A / V1 <B / V2. The same effects as in the first embodiment can be obtained. Further, by adjusting the setting of the reduction ratio of the third gear 328 and the fourth gear 330, the distance A from the alignment reference wall X to the upstream end in the discharge direction of the first sheet S1, and the first and second sheets S1, S2 The shift amount α can be set roughly.

  By the way, in the first to third embodiments described so far, the first two sheets of the succeeding job are made to wait inside, and the two reference sheets X are aligned by two alignment rollers. The case of transporting to the above has been described. However, the present invention is not limited to this. For example, the finisher is configured to convey three or more sheets to the alignment reference wall X after the lower sheet is abutted against the alignment reference wall X by three or more alignment rollers in contact with each sheet. 300 may be applied.

  In addition, until now, the alignment reference wall X has been provided on the upstream side of the intermediate stacking unit 303 in the sheet discharge direction, and when processing sheets, the first and second alignment rollers 306a, 306a, The case where 306b is rotated has been described. However, the present invention is not limited to this. For example, an alignment reference wall may be provided on the downstream side of the intermediate stacking unit 303 in the sheet discharge direction. When processing the sheet, the first and second alignment rollers 306a and 306b may be rotated so that the downstream end in the sheet discharge direction, which is one end of the sheet in the sheet discharge direction, abuts the alignment reference wall. good.

DESCRIPTION OF SYMBOLS 100 ... Copier, 100A ... Copier main body, 100B ... Image forming part, 119 ... Discharge roller pair, 300 ... Finisher, 303 ... Intermediate stacking part, 306 ... Rear end aligning part, 306a, 306b ... First and second aligning Roller, 317 ... Rotating member, 323 ... First holding member, 324 ... Second holding member, 325 ... First gear, 327 ... Second gear, 328 ... Third gear, 330 ... Fourth gear, 340 ... Drive unit , 400 ... control unit, 410 ... elevating unit, 420 ... alignment motor, S ... sheet, S1 ... first sheet, S2 ... second sheet, X ... alignment reference wall

Claims (5)

A sheet stacking unit for stacking sheets to be processed;
An alignment reference member for positioning the sheet in the sheet discharge direction by contacting one end of the sheet discharged in the sheet stacking unit in the sheet discharge direction
A processing unit that processes the sheet positioned in the sheet discharge direction by the alignment reference member;
A standby unit for waiting in a state where the sheets conveyed while the sheets are processed by the processing unit;
A discharge unit that discharges to the sheet stacking unit in a state where one end in the sheet discharge direction of the lower sheet is shifted closer to the alignment reference member than one end of the upper sheet in the sheet discharge direction from the standby unit;
The alignment reference member is provided so as to be able to move up and down above the sheet stacking unit, and when the sheets are stacked and discharged on the sheet stacking unit, the sheets are lowered to contact each sheet of the stacked sheets, and each sheet is conveyed to the alignment reference member A plurality of sheet conveying sections that abut against
Of the plurality of sheet conveying units, the lower sheet is abutted against the alignment reference member by the first sheet conveying unit that is in contact with the lower sheet, and is then conveyed by the second sheet conveying unit that is in contact with the upper sheet. A sheet processing apparatus, wherein an upper sheet reaches the first sheet conveying unit.   The distance A between one end of the alignment reference member and the lower sheet in the sheet discharge direction when the first sheet conveying unit is lowered and comes into contact with the lower sheet, and the lower sheet of the first sheet conveying unit lowered. The preceding amount of the distance A and the lower sheet of the upper sheet is set so that the relationship between the contact position and the distance B of one end of the upper sheet in the sheet discharge direction is A <B. Item 2. The sheet processing apparatus according to Item 1. An elevating unit for elevating and lowering the first sheet conveying unit and the second sheet conveying unit;
The elevating unit lowers the first sheet conveying unit, and then the distance A between one end of the alignment reference member and the lower sheet in the sheet discharge direction when the first sheet conveying unit comes into contact with the lower sheet. When the relationship between the contact position of the lowered first sheet conveying unit with the lower sheet and the distance B of one end of the upper sheet in the sheet discharge direction is A <B, the second sheet is in contact with the upper sheet. The sheet processing apparatus according to claim 1, wherein the sheet conveying unit is lowered. A driving unit for driving the first sheet conveying unit and the second sheet conveying unit;
The driving unit includes a distance A between one end of the alignment reference member and the lower sheet in the sheet discharge direction when the first sheet conveying unit is lowered and abuts the lower sheet, and the first sheet conveying unit is lowered. The relationship between the contact position with the lower sheet and the distance B between the one end in the sheet discharge direction of the upper sheet, the sheet conveying speed V1 of the first sheet conveying unit, and the sheet conveying speed V2 of the second sheet conveying unit is as follows: 2. The sheet processing apparatus according to claim 1, wherein the first sheet conveying unit and the second sheet conveying unit are driven at a sheet conveying speed such that A / V1 <B / V2.   An image forming unit that forms an image on a sheet, and the sheet processing apparatus according to claim 1 that processes the sheet on which an image is formed by the image forming unit. Image forming apparatus.

Images