JP2006151591A - Sheet handling device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet handling device capable of excellently delivering sheets, which are delivered onto a first stacking means, onto the first stacking means with a bundle delivering means, while preventing delivery of a sheet, which is curled large upward, onto the first stacking means. <P>SOLUTION: A sheet existence flag 101 is provided to appear/disappear from a surface of a handling tray. When the sheets are stacked on the handling tray, the flag 101 pushed downward by the sheets is detected by a flag sensor 102, and existence of the sheets is thereby detected. When a sheet P<SB>1</SB>having a large curl in a rear end thereof is delivered onto the handling tray, the sheet P<SB>1</SB>, of which rear end is caught by a guide member 7, does not push the flag 101 downward, and no-existence of sheet is thereby detected. In this case, a through-put of of an image forming device on an upstream side is lowered to reduce the curl. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus that process a sheet after image formation, for example.

  In Patent Document 1, a sheet discharged from an image forming apparatus such as a copying machine or a printer is temporarily discharged onto a processing tray (first stacking unit), and alignment or binding processing is performed on the processing tray. Thereafter, a sheet processing apparatus has been proposed in which the sheet is discharged onto a stack tray (second stacking means) by a claw bundling means (bundle discharging means).

JP 2000-169028 A

  However, the sheet processing apparatus disclosed in Patent Document 1 may not be able to stack orderly on the processing tray when the sheet discharged from the image forming apparatus has an upper curl. In such a case, the claw bundling means may not be able to discharge the stack tray.

  For example, when the upper curl of the sheet discharged from the image forming apparatus to the sheet processing apparatus is large, the upper curl portion of the sheet leans against the sheet discharge port even if the sheet is pulled into the processing tray by the sheet scraping unit. Therefore, the sheets cannot be neatly stacked on the processing tray. When such a phenomenon occurs, the claw bundling means passes under the upper curled portion of the sheet, and the leading edge of the sheet cannot be gripped well. Can no longer be discharged.

  Therefore, in the present invention, the sheet discharged on the first stacking unit is favorably placed on the first stacking unit by the bundle discharging unit so that the sheet having a large upper curl is not discharged onto the first stacking unit. It is an object of the present invention to provide a sheet processing apparatus and an image forming apparatus that can be discharged to each other.

  The present invention includes a discharge unit that discharges a sheet conveyed from a sheet supply unit, a first stack unit that stacks sheets discharged from the discharge unit as a sheet bundle, and a stack on the first stack unit. Sheet processing means for processing the sheet bundle, a bundle discharge means for discharging the processed sheet bundle from the first stacking means, and a second stack for stacking the sheets discharged from the bundle discharge means A sheet processing apparatus comprising: means for outputting a sheet presence / absence detecting means for detecting the presence / absence of a sheet on the first stacking means and a signal for changing control of the sheet conveying system on the sheet supply means side Control means, and the control means controls the sheet conveying system on the sheet supply means side based on the detection result of the sheet presence / absence detection means.

  According to the present invention, the control unit can control the sheet conveyance system on the sheet supply unit side based on the detection result of the sheet presence / absence detection unit. Therefore, if the sheet presence / absence detection unit is configured to detect the presence of a sheet when the sheets stacked on the first stacking unit are normal, for example, and detect the absence of a sheet when the sheets are not normal, The control unit can appropriately control the sheet conveyance system so that the sheet conveyed and stacked on the first stacking unit is normal. As a result, the sheet bundle processed by the sheet processing means can be satisfactorily discharged from the first stacking means onto the second stacking means by the bundle discharging means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, what attached | subjected the same code | symbol in each drawing has the same structure or the same effect | action, The duplication description about these was abbreviate | omitted suitably.

<Embodiment 1>
FIG. 1 is a front longitudinal sectional view schematically showing an image forming apparatus to which the present invention can be applied. As shown in FIG. 1, the image forming apparatus is configured by combining an image forming apparatus main body 1 and a sheet processing apparatus 2. Here, as the image forming apparatus main body 1, a copying machine, a printer, a facsimile, a printing machine, or the like can be used. In the following description, the case where the image forming apparatus main body 1 is a copying machine will be described as an example. .

  The image forming apparatus main body 1 optically reads a document automatically fed from an automatic document feeder (ADF) 20 disposed at an upper portion thereof by a reader unit (image reading unit) 22 and uses the read information as a digital signal. A toner image (image) is formed on a sheet P such as plain paper or a transparent film for OHP (overhead projector) by transmitting to a printing unit (image forming unit) 23.

  A plurality of paper feed cassettes 24 that store sheets P of various sizes are mounted at the bottom of the image forming apparatus main body 1. A manual feed tray 28 is provided on the right side surface of the image forming apparatus main body 1. The sheet P fed from the paper feed cassette 24 or the manual feed tray 28 and transported by the transport roller 25 is supplied to the transfer section between the photosensitive drum 23b and the transfer device 23c of the print section 23 by the registration roller 29.

  On the other hand, in the printing unit 23, a toner image is formed by an electrophotographic method. That is, the laser beam emitted from the exposure device 23a based on the information read by the reader unit 22 is applied to the uniformly charged photosensitive drum 23b, and the charge of the irradiated portion is removed to form an electrostatic latent image. It is formed. The electrostatic latent image is developed as a toner image with toner attached thereto by the developing device 23d. The toner image thus formed on the photosensitive drum 23b is transferred by the transfer device 23c to the sheet P supplied to the transfer portion as described above. After the toner image has been transferred, the toner remaining on the surface of the photosensitive drum 23b (transfer residual toner) is removed by a cleaning device (not shown) and used for the next image formation. On the other hand, the sheet P after the transfer of the toner image is conveyed to the fixing device 26 where it is heated and pressed to permanently fix the toner image on the surface.

  Thus, the sheet P having the toner image fixed on one side (front side) is sent to the sheet processing apparatus 2 in the single-sided recording mode. On the other hand, in the double-sided recording mode, the sheet P after fixing the toner image is turned upside down by switchback, and then conveyed to the retransmission path 27 and again conveyed to the printing unit 23 to the other side (back side). After the toner image is formed, the sheet is fed into the sheet processing apparatus 2.

  FIG. 2 is a longitudinal sectional view showing the configuration of the sheet processing apparatus 2, and FIG. 3 is an enlarged top view in the vicinity of the processing tray (described later) in FIG. The sheet processing apparatus 2 will be described in detail with reference to FIGS.

  The sheet processing apparatus 2 is connected to the image forming apparatus main body 1 and constitutes an image forming apparatus together with the image forming apparatus main body 1. A conveyance guide 3 is disposed on the upper portion of the sheet processing apparatus 2. The conveyance guide 3 guides the sheet P discharged from the paper discharge rollers 1 a and 1 b of the image forming apparatus main body 1. The conveyance guide 3 includes, in order from the upstream side in the conveyance direction of the sheet P (right side in FIG. 1), a sheet detection sensor 4 that detects the sheet P conveyed to the conveyance guide 3, and a conveyance roller pair that nipping and conveying the sheet P. 5. A discharge roller pair 6 exemplified as discharge means for holding and discharging the sheet P is disposed. A guide member 7 for guiding a sheet P on a processing tray 8 (described later) is provided in the vicinity of the discharge roller pair 6. Below the guide member 7, a processing tray 8 exemplified as a first stacking unit is disposed. The processing tray 8 is inclined so that the end portion on the image forming apparatus main body 1 side (the right end portion in the figure) is positioned below, and the sheet P discharged from the discharge roller pair 6 is stapled. When processing or folding processing is performed, it is once loaded. As shown in FIG. 3, the processing tray 8 is divided into three in the sheet width direction (direction orthogonal to the sheet conveying direction), and a transfer belt 12 (described later) is disposed between the processing trays 8. . An alignment plate 9 is disposed on the processing tray 8. The alignment plates 9 are respectively disposed at both ends of the processing tray 8 in the sheet width direction. A rack 16 is fixed to the lower portion of each alignment plate 9 in the sheet width direction, and a pinion 15 meshed with the rack 16 is rotated by a motor (alignment motor on the front side and the back side) 14 to rotate the rack 16. The alignment plate 9 can be moved in the sheet width direction via the rack 16.

  A paddle 17 (see FIG. 2) is disposed above the processing tray 8. The paddle 17 is for drawing the sheet P discharged onto the processing tray 8 so as to further overlap the sheet P onto the processing tray 8.

  In the vicinity of one end of the processing tray 8 (the right end in the figure), a stopper 21 is provided for receiving the rear end of the sheet P loaded on the processing tray 8 and sliding down by its own weight. . Below the processing tray 8, two transfer belts 12 constituting a conveying unit are disposed. The transfer belt 12 is stretched between the two first pulleys 10 fixed to the first pulley shaft 10a and the two second pulleys 11 fixed to the second pulley shaft 11a. ing. The transfer belt 12 will be described in detail later. An extrusion claw 13 exemplified as a bundle discharging means is attached to a part of the outer periphery of each transfer belt 12. Further, four lower conveying rollers 18 are attached to the first pulley shaft 10a.

  As shown in FIG. 2, the sheet processing apparatus 2 includes, for example, a stapler 30 as sheet processing means. The stapler 30 is composed of a lower stapler 31 and an upper stapler 32 that are disposed across the transport path. The lower stapler 31 has a needle cartridge, a driving portion for driving the needle, a needle feeding portion for feeding the needle from the needle cartridge to the driving portion, and the like. The upper stapler 32 has a bent portion that bends a needle hit from the lower stapler 31. Further, the upper stapler 32 and the lower stapler 31 are respectively guided by shafts 37 and 38 and can move in the thrust direction (sheet width direction). The lower stapler 31 has a threaded portion that engages with a screw shaft 36 having a helical thread groove on the outer periphery, and can move in the thrust direction by the rotation of the screw shaft 36. The upper stapler 32 has a threaded portion that engages with a screw shaft 35 having a helical thread groove on the outer periphery, and can move in the thrust direction by the rotation of the screw shaft 35.

  The sheet processing apparatus 2 includes an elevating tray 90 exemplified as the second stacking unit. The elevating tray 90 is attached to an elevating mechanism 92 that can elevate in the vertical direction, and can move between a solid line and a two-dot chain line in FIG. The lift tray 90 is provided with a freely accessible auxiliary tray 91 for accommodating a large sheet P. A paper surface sensor 93 that detects the uppermost surface of the sheets P stacked on the lifting tray 90 is disposed at the base end of the lifting tray 90. The rear end guide 94 provided in the vicinity of the base end portion of the elevating tray 90 is formed substantially vertically and guides the rear end of the sheet P on the elevating tray 90 that moves in the vertical direction.

  A sheet folding device 50 is provided in the sheet processing apparatus 2 shown in FIG. The sheet folding device 50 includes conveyance rollers 51 and 52 for nipping and conveying the sheet bundle, a conveyance guide 53 for guiding the conveyed sheet bundle, a rear end detection first sensor 54, a thrust plate 55, folding rollers 57a and 57b, a folding guide. 59a, 59b and paper discharge rollers 60a, 60b.

  The rear end detection sensor 54 described above is configured by a reflection type photosensor, and is used when controlling the staple position during stapling. In the present embodiment, the thrust plate 55 is configured by a plate having a tip thickness of about 0.3 mm. The folding rollers 57a and 57b are pressed against each other, and both rollers are driven to rotate. The above-mentioned thrust plate 55 enters or retreats to the vicinity of the nip between the folding rollers 57a and 57b. One of the paper discharge rollers 60a and 60b is a driving roller that is driven and rotated, and the other is a driven roller that is driven by the driving roller and rotates.

  Below the sheet folding device 50, a sheet bundle tray 80 as a second stacking unit is disposed. The sheet bundle tray 80 is a tray on which the sheet bundle folded by the sheet folding device 50 is discharged and stacked. The sheet bundle tray 80 has a weight 81 for ensuring good stackability by pressing the stacked sheet bundle from above.

  Two transfer belts 12 are disposed on the processing tray 8 (see FIG. 3). The transfer belt 12 is stretched around the first pulley 10 and the second pulley 11, respectively, and is disposed on both sides of the substantially center in the sheet width direction. On the first pulley shaft 10a, two conveyance lower rollers 18 are provided on both sides of the substantially center in the sheet width direction. The lower conveyance roller 18 is a tire-type hollow roller.

  Two first pulleys 10 for rotating the transfer belt 12 as described above are disposed on the first pulley shaft 10a. The first pulley 10 is driven and rotated by the counterclockwise rotation of the first pulley shaft 10a in FIG. 2 by a one-way clutch 75 interposed between the first pulley 10 and the first pulley shaft 10a. In the clockwise rotation, the drive is cut and stopped. The first pulley shaft 10a is connected to a motor shaft 70a of a conveyance stepping motor 70 as a conveyance drive source via a pulley 73b fixed to the first pulley shaft 10a, a timing belt 74, and gear pulleys 72 and 71. Yes.

  Therefore, when the stepping motor 70 rotates the sheet P on the processing tray 8 in the direction of moving in the stapling direction (arrow B direction) in FIGS. 1 to 3, the lower conveying roller fixed to the first pulley shaft 10a. 18 is driven to rotate, but the driving force is not transmitted to the transfer belt 12 by the one-way clutch 75, and the transfer belt 12 is in a stopped state. When the stepping motor 70 rotates so as to move the sheet P toward the lifting tray 90, the lower conveying roller 18 and the transfer belt 12 are both in the direction of the lifting tray 90 (the direction of arrow A in FIGS. 1 to 3). Rotate.

  The transfer belt 12 will be further described with reference to FIG. The transfer belt 12 stretched between the first pulley 10 attached to the first pulley shaft 10a via the one-way clutch 75 and the second pulley 11 is provided with the pushing claw 13 as described above. ing. As the transfer claw 13 rotates and moves in the direction of arrow A, the tip of the push-out claw 13 moves in a track shape along the two-dot chain line shown in FIG. In order to locate the home position (HP) of the push-out claw 13, a push-out claw detection arm 77 that engages with the push-out claw 13 and a push-out claw sensor 76 are provided on the lower surface of the processing tray 8. The position at which the pushing claw 13 is moved by the transfer belt 12 to push the pushing claw detection arm 77 and the pushing claw sensor 76 is switched from OFF to ON is defined as a home position (HP).

  Further, the transport upper roller 19 is moved up and down by a cam, a drive link, and a driven link (all not shown) so as to contact and separate from the transport lower roller 18. That is, it can swing between a first position (separated position) indicated by a solid line and a second position (contact position) indicated by a two-dot chain line in FIG. The transport upper roller 19 is disposed at the second position, and forms a nip with the transport lower roller 18 when the transport lower roller 18 is pressed.

  By the operation of a cam or the like, the transport upper roller 19 is lowered and disposed at the second position, and is pressed against the transport lower roller 18. Thereafter, when the conveyance stepping motor 70 is rotated and the first pulley shaft 10a is rotated counterclockwise in FIGS. 2 and 4, the conveyance lower roller 18 is rotated and the sheet bundle is directed toward the lifting tray 90. Move in the direction of arrow A. The above-described transport upper roller 19 is also rotated by the transport stepping motor 70 in conjunction with a transport stepping motor 70 (see FIG. 3) via a belt and a gear (not shown). Accordingly, the sheet bundle moves from the position of the stopper 21 entering the stapler 30 side in the direction of arrow A due to the rotation of the lower conveyance roller 18 and the upper conveyance roller 19, but the rear end of the sheet bundle is between the two rollers. After passing the nip, the sheet is conveyed in the direction of arrow A by the push-out claw 13 as the transfer belt 12 rotates.

  However, when the sheet P having a large upper curl is discharged from the paper discharge roller 6, the rear end of the sheet is leaned against the guide member 7 in the vicinity of the paper discharge roller 6. For this reason, the sheet P cannot be pulled onto the processing tray 8 by the paddle 17 (see FIG. 2), and the sheet P cannot be pulled back to the trailing edge stopper 21 (state shown in FIG. 6). If the normal operation is performed in this state, the pushing claw 13 passes under the sheet P, and thus the sheet P cannot be conveyed to the lifting tray 90. Further, in the staple mode, there is a possibility that the staple operation is performed even if the sheet P is not present, and the staple unit is adversely affected.

  In order to prevent such a problem, as shown in FIGS. 4, 5, and 6, for example, a sheet presence / absence sensor (processing tray sheet detection sensor) 100 is provided as a sheet presence / absence detection unit in the processing tray 8. The sheet presence / absence sensor 100 is disposed in the vicinity of the rear end of the sheet stacked on the processing tray 8 and in the vicinity of the push-out claw 13 disposed in the home position. As the sheet presence sensor 100, for example, a sensor having a sheet presence flag 101 and a flag sensor 102 can be used. In the present embodiment, as shown in FIGS. 4 and 6, the sheet presence / absence flag 101 has a detection unit 101a and a light shielding unit 101b, and is substantially centered on an axis 101c at the base end of the detection unit 101a. It is configured to be swingable in the vertical direction. That is, the detection unit 101a is configured to be able to enter and exit (exit and retract) on the surface of the processing tray 8. The sheet presence / absence flag 101 is lightly urged upward by an urging member (not shown), and when there is no sheet P on the processing tray 8, the detection unit 101a protrudes upward from the surface of the processing tray 8. To do. At this time, the light shielding unit 101b opens the optical path of the flag sensor 102. On the other hand, the sheet presence / absence flag 101 is retracted from the surface of the processing tray 8 by the sheet P when the sheet P is on the processing tray 8. At this time, the light shielding unit 101b blocks the optical path of the flag sensor 102. Thereby, it is detected that the sheet P is on the processing tray 8.

As described above, the sheet presence / absence sensor 100 used in the present embodiment detects the absence of a sheet when the detection unit 101a of the sheet presence / absence flag 101 protrudes from the surface of the processing tray 8, and detects the sheet presence / absence flag 101. When the portion 101a is pushed down by the sheet P and retracted from the surface of the processing tray 8, it is configured to detect the absence of the sheet. Therefore, even after the sheet P is discharged from the discharge roller pair 6 and discharged onto the processing tray 8 and the drawing operation for the sheet P is completed by the paddle 17, for example, at the rear end of the sheet P. state as the trailing edge of the sheet upward large curl is not generated is caught by the guide member 7 (the state shown by the sheet P ₁ in FIG. 6. in other words if spacing amount of the sheet P from the processing tray surface is large.) Then, this sheet P cannot push down the detection unit 101a of the sheet presence sensor 101 from the surface of the processing tray 8. In this case, the sheet presence / absence detection sensor 100 detects the absence of a sheet. In other words, the sheet presence / absence sensor 100 according to the present embodiment functions as a sheet presence / absence sensor for a sheet P having no or even a curl at the rear end, and for a sheet P having a large curl at the rear end. Therefore, it functions as a sensor for notifying that the push-out pawl 13 does not normally engage with the rear end of the sheet because the curl amount is large (or the rear end is caught by the guide member 7). That is, the sheet presence / absence detection sensor 100 is also used as a sensor for estimating the curl amount at the trailing edge of the sheet. Thereby, compared with the case where two separate sensors are arrange | positioned, the whole structure can be simplified.

  Immediately after the sheet P is discharged from the paper discharge roller 6 and the sheet P is pulled by the paddle 17, the state of the sheet presence sensor 100 provided on the processing tray 8 is monitored. If it is detected that the sheet P is present, a normal operation is performed. If it is detected that the sheet P is not present, the information is sent to the image forming apparatus main body 1 and the control is changed to a curl control.

  The curl amount of the sheet P greatly depends on the roll pressure applied to the sheet P and the amount of heat required for fixing when the sheet P passes through the fixing device 26 (see FIG. 1). If the sheet P is transported by a small distance or a large amount of sheets P is transported at a time when the interval between the sheets P is narrowed, the temperature of the fixing device 26 becomes unstable because the sheet P rapidly takes heat from the fixing device 26. Large sheet P may be discharged.

  Therefore, when the sheet P is conveyed at a low speed or when the interval between successive sheets is increased, the temperature of the fixing device 26 can be appropriately adjusted and stabilized, and the curl amount is reduced.

  In the present embodiment, when the image forming apparatus main body 1 used continuously forms an image, the amount of curling of the sheet P is reduced when the interval between two continuous sheets P is increased more than usual. Therefore, for example, when the throughput of the image forming apparatus main body 1 during normal image formation is 50 sheets / minute, the sheet conveying system of the image forming apparatus main body 1 is controlled so that the throughput is reduced to 31 sheets / minute. By performing such control, a sheet P with less curling is supplied from the image forming apparatus main body 1 to the sheet processing apparatus 2, and the sheet processing apparatus 2 can perform normal processing on the sheet P. .

  FIG. 7 shows a schematic block diagram relating to the control of the sheet processing apparatus 2. The control block 110 includes a central processing unit (CPU), a ROM preliminarily storing control means (control program or the like) corresponding to a control procedure to be described later executed by the CPU, CPU arithmetic data, and the image forming apparatus main body 1. It consists of RAM etc. which memorize | stores the received control data.

  This control block 110 is provided with various I / Os. An arrow pointing to the control block 110 side is an input side, and an arrow pointing away from the control block 110 is an output side.

  As shown in the figure, the control block 110 includes a block 111 related to conveyance and bundle conveyance, a block 112 related to paddle, a block 113 related to stapling / folding, a block 114 related to alignment, a block 115 related to lifting tray, and a sheet. A detection-related block 116, a door opening / closing device detection-related block 117, and an interface controller 120 are connected.

In the present embodiment, the sheet P after the image is formed by the image forming apparatus main body 1 is discharged from the image forming apparatus main body 1 by the discharge rollers 1a and 1b, supplied to the sheet processing apparatus 2, and further The paper is discharged onto the processing tray 8 by the paper discharge roller pair 6, and is pulled on by the paddle 17 and stacked on the processing tray 8. At this time, when the sheet P on the processing tray 8 is not curled or when the curl is small, the sheet P (sheet P _{2 in} FIG. 5) is pulled by the paddle 17 as shown in FIG. The end comes into contact with the stopper 21 and is normally stacked on the processing tray 8. In this case, the sheet presence / absence flag 101 is pushed down below the processing tray 8 by the sheet P on the processing tray 8, and the light shielding unit 101 b blocks the optical path of the flag sensor 102. That is, the presence / absence of a sheet is detected by the sheet presence / absence sensor 100.

On the other hand, when the curl of the sheet P discharged onto the processing tray 8 by the pair of discharge rollers 6 and pulled by the paddle 17 and stacked on the processing tray 8 is large, it is shown in FIG. As described above, the sheet P (the sheet P _{1 in} FIG. 6) cannot be pushed down by the trailing end of the sheet P being caught by the guide member 7. Therefore, the optical path of the flag sensor 102 is not blocked by the light shielding portion 102b. That is, the presence / absence of the sheet P is detected by the sheet presence / absence sensor 100.

  Therefore, in the present embodiment, after the sheet P is discharged from the discharge roller 6 and the pulling-in operation of the paddle 17 is finished, the sheet presence sensor 100 is monitored, and the CPU of the control block 110 indicates that the sheet P is not present. For example, when the count is performed three times, the sheet conveying and discharging unit on the image forming apparatus main body 1 side is controlled via the interface controller 120. The curl amount of the sheet P discharged from the image forming apparatus main body 1 is reduced by controlling the interval (interval) between the sheets P sequentially discharged from the image forming apparatus main body 1 to be larger than usual. .

  As described above, according to the sheet processing apparatus 2 according to the present invention, when the sheet P having a large upper curl is discharged from the image forming apparatus body 1, the curl is detected by the sheet processing apparatus 2, and a part of the control block 110 is detected. Acts as a sheet conveyance system control means, and by increasing the interval at which the sheets P of the image forming apparatus main body 1 are discharged, the curl amount of the discharged sheets P can be reduced and good stackability can be obtained. .

  For example, a plurality of sheet presence / absence sensors 100 similar to those described above may be provided along the sheet passing width direction of the sheet P. In this case, the sheet presence / absence sensor 100 can detect the presence / absence of the sheet with higher accuracy. That is, for example, when even one of the plurality of sheet presence / absence sensors 100 is detected, the sheet on the processing tray 8 is sequentially discharged from the image forming apparatus main body 1 as having a large upper curl. It is preferable to control the interval (sheet interval) between the sheets P to be larger than usual.

  Further, as control with less curl, in this embodiment, when the normal image formation throughput of the image forming apparatus main body 1 is 50 sheets / minute, the throughput is reduced to 31 sheets / minute, and the interval between sheets P (paper However, other than that, the sheet P may be kept at the same interval and the conveyance speed of the sheet P may be decreased. By reducing the conveying speed of the sheet P passing through the fixing device 26, it is possible to adjust the temperature appropriately, and the curl amount of the discharged sheet P can be reduced to obtain good stackability.

  In addition, as a control with less curl, a normal curl removal mechanism (not shown) is separately provided downstream of the fixing device 26 so that the transport path can be switched, and the transport path is configured to transport the curl removal mechanism when control with less curl is performed. You may control to switch. By controlling in this way, the curl amount of the discharged sheet P can be reduced, and good stackability can be obtained.

  The case where the sheet supply apparatus is the image forming apparatus main body 1 has been described above as an example, but the sheet processing apparatus according to the present invention is not limited to this. In other words, according to the present invention, the sheet feeding apparatus can be any apparatus other than the image forming apparatus as long as it supplies sheets to the sheet processing apparatus.

  Further, the control block (CPU) 110 of the sheet processing apparatus 2 controls the image forming apparatus main body 1 via the interface controller 120. However, the CPU 110 may be integrated with the image forming apparatus main body 1, The forming apparatus main body 1 may control the image forming apparatus main body 1 by receiving detection signals from the various sensors. By configuring the CPU of the sheet processing apparatus 2 in the image forming apparatus main body 1, the sheet processing apparatus 2 can be simplified. The image forming apparatus can integrally control the entire image forming apparatus.

1 is a longitudinal sectional view schematically illustrating a schematic configuration of an image forming apparatus including an image forming apparatus main body and a sheet processing apparatus. It is a longitudinal cross-sectional view which shows the structure of a sheet processing apparatus. It is a top view of the vicinity of the processing tray. It is a front view of the processing tray vicinity. FIG. 6 is a diagram for explaining a state in which a sheet having no curl at the rear end is stacked on a processing tray and the rear end is in contact with a stopper. FIG. 10 is a diagram illustrating a state where a sheet with a curl at the rear end is stacked on a processing tray and the rear end is caught by a guide member. It is a schematic control block diagram of a sheet processing apparatus.

Explanation of symbols

1 Image forming device body (sheet feeding device)
2 Sheet processing device 6 Paper discharge roller pair (discharge means)
8 processing tray (first stacking means)
13 Extrusion claw (bundle discharging means)
23 Print section (image forming section)
30 Stapler (sheet processing means)
90 Lifting tray (first loading means)
100 Sheet presence sensor (sheet presence detection means, processing tray sheet detection sensor)
110 Control block (control means)

Claims (8)

A discharge unit that discharges the sheet conveyed from the sheet supply unit; a first stacking unit that stacks the sheets discharged from the discharge unit as a sheet bundle; and a sheet bundle stacked on the first stacking unit A sheet processing means for processing the sheet, a bundle discharging means for discharging the processed sheet bundle from the first stacking means, and a second stacking means for stacking the sheets discharged from the bundle discharging means. In the sheet processing apparatus,
Sheet presence / absence detection means for detecting the presence / absence of sheets on the first stacking means;
Control means capable of outputting a signal for changing the control of the sheet conveying system on the sheet supply means side,
The control unit controls a sheet conveyance system on the sheet supply unit side based on a detection result of the sheet presence / absence detection unit;
A sheet processing apparatus. The control means controls the sheet supply interval to be larger than normal when a sheet is discharged from the discharge means onto the first stacking means and the sheet presence / absence detection means detects no sheet. Emit a signal,
The sheet processing apparatus according to claim 1. The sheet presence / absence detecting means is disposed in the vicinity of the rear end side of the sheet on the first stacking means and in the vicinity of the bundle discharging means.
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. The sheet presence / absence detection means detects the absence of a sheet when a separation amount of the rear end side of the sheets stacked on the first stacking means from the first stacking means is large;
The sheet processing apparatus according to claim 3. A plurality of the sheet presence / absence detection means are provided,
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. The sheet processing means is a stapler that performs a binding process on a sheet bundle on the first stacking tray;
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. An image forming main body as a sheet supply device having an image forming unit for forming an image on the sheet; and a sheet processing device for processing the sheet supplied from the image forming main body,
The sheet processing apparatus is the sheet processing apparatus according to any one of claims 1 to 6.
An image forming apparatus. An image forming unit that forms an image on a sheet;
A stacking means for stacking image-formed sheets;
Sheet conveying and discharging means for conveying and discharging an image-formed sheet to the stacking means;
Sheet conveyance system control means for controlling the sheet conveyance discharge means;
Sheet presence / absence detection means for detecting the presence / absence of sheets on the stacking means,
The sheet conveyance system control means controls the sheet conveyance discharge means based on a detection result of the sheet presence / absence detection means;
An image forming apparatus.

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