JP2010189104A - Paper stacking device, paper postprocessing device and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper stacking device that is compatible with high speed carrying of the paper, without causing dislocation and a jam of stacked paper. <P>SOLUTION: The paper stacking device has a paper ejecting means composed of paper support tables 33b(33A) arranged slantingly and supporting the paper and a pair of rollers 37B(37A) and 32A(32B) arranged in an upper part of the paper support tables and capable of contacting with and separating from each other, and guide means 38A(38B, 38C and 38D) having a paper guide for guiding the paper. The guide means displaces the paper existing on the paper guide to a first position of not contacting with one paper carrying surface of the pair of rollers and a second position retreated from the first position. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a sheet stacking apparatus, a sheet post-processing apparatus, and an image forming system that discharge after stacking a plurality of sheets.

  In a sheet post-processing apparatus that performs post-processing on a sheet on which an image is formed by an image forming apparatus, a sheet stacking apparatus that stacks a plurality of sheets is used.

  Patent Document 1 discloses a sheet post-processing apparatus that is disposed upstream of a staple unit and includes a transport unit that stacks two sheets as a pre-stage process of stapling.

Japanese Patent Laid-Open No. 11-157741

  In Patent Document 1, two sheets are stacked, but even when a small number of sheets are stacked as in Patent Document 1, in order to improve the alignment in the transport direction of the sheet, the support inclined to the transport direction is used. A paper stacking unit having a table is excellent. That is, by dropping the paper on the inclined support table, alignment in the transport direction is automatically performed, so that the paper is aligned with high accuracy and accumulated.

  However, it has been found that there is a problem in the paper stacking unit having the inclined support base. This problem will be described with reference to FIGS.

  The paper post-processing apparatus or the like is provided with a paper stacking unit 30 arranged at an inclination. The paper S is introduced into the paper stacking unit 30 as indicated by an arrow W1. When the paper is introduced, the driven roller 32 and the driving roller 37 are separated from each other, and the paper S passes through the gap between the driven roller 32 and the driving roller 37 and proceeds to the upper left as indicated by an arrow W3. Thereafter, the paper S falls on the paper stacking unit 30 as indicated by an arrow W2, and the lower end of the paper hits the stop member 41 and stops. When the paper S is discharged from the paper stacking unit 30, the driven roller 32 descends, the rollers 32 and 37 nip the paper S, and the driving roller 37 rotates to move the paper S to the upper left as indicated by an arrow W3. Transport and eject. In the process from the introduction of the paper to the discharge in the paper stacking unit 30, the rollers 32 and 37 carry the paper only at the time of paper discharge, and therefore need only rotate at the time of paper discharge. However, when repeated operations are performed such as stopping at the time of introduction and rotating at the time of paper discharge, it becomes difficult to accurately start and stop the members constituting the conveying means, and the stability of the conveyance is lowered. is there. Especially speedup. When increasing productivity, there is a problem that the apparatus cannot be used. For this purpose, a configuration is adopted in which the drive roller 37, which is a drive roller, is always rotated. That is, the drive roller 37 always rotates as indicated by an arrow W4. When the paper is introduced, it is necessary that the paper S does not pass through the gap between the roller 32 and the driving roller 37 and the paper S is not conveyed by the rotation of the driving roller 37. That is, when the paper is introduced, it is necessary that the paper S is not transported and discharged by the drive roller 37 as indicated by the arrow W3. However, as shown in FIG. 2A, the sheet S comes into contact with the drive roller 37, so that in practice, the conveying action of the drive roller 37 with respect to the sheet passing through the gap between the separated rollers works, and the sheet is introduced at the time of introduction. May be discharged.

  In order to avoid this, as shown in FIG. 2, a guide member 38 that prevents the paper S from contacting the drive roller 37 is provided. That is, the paper guide surface of the guide member 38 is formed slightly higher than the peripheral surface of the drive roller 37, and the paper S does not contact the drive roller 37. Therefore, as shown in FIG. 37 is not conveyed.

  At the time of paper discharge, the roller 32 is lowered to bring the paper S into contact with the driving roller 37. 2C, the sheet S is conveyed by the drive roller 37 and discharged. However, the frictional resistance of the guide member 38 acts on the paper S in the state of FIG. The frictional resistance of the guide member 38 causes problems such as the occurrence of a jam and the misalignment of a plurality of sheets in the transport direction.

  The present invention solves the above-described problems in the paper stacking unit, enables high-speed transport of paper, and does not cause jamming or misalignment in the transport direction of a plurality of sheets, An object of the present invention is to provide a sheet post-processing apparatus and an image forming system.

  The object is achieved by the following invention.

1. A sheet support that is disposed at an angle and supports a sheet; a sheet discharge unit that is disposed on an upper portion of the sheet support; and includes a pair of rollers that can contact and separate from each other;
A guide means having a paper guide section for guiding paper,
The guide means is displaced to a first position where the paper on the paper guide portion is not brought into contact with one paper transport surface of the pair of rollers, and a second position retracted from the first position. Paper stacking device.

  2. The guide means is characterized in that the paper guide portion is displaced to the first position higher than the paper transport surface and the paper guide portion is displaced to the second position that is the same as or lower than the paper transport surface. 2. The paper stacking apparatus according to 1 above.

  3. The sheet guide section is located at the first position when the pair of rollers are separated from each other, and the guide means is operated at the second position when the pair of rollers are in contact with each other. 3. The paper stacking apparatus according to 1 or 2 above, wherein

  4). 4. The paper stacking apparatus according to 3, wherein the paper guide unit is pushed by the paper and retracted to the second position when the pair of rollers contact with each other through the paper.

  5. 4. The sheet accumulating apparatus according to any one of 1 to 3, further comprising a displacement unit that retracts the guide unit to the second position.

  6). 6. The sheet stacking apparatus according to 5, wherein the other of the pair of rollers constitutes the displacement unit.

  7). A paper post-processing apparatus comprising the paper stacking apparatus according to any one of 1 to 6 above.

  8). 8. The sheet post-processing apparatus according to claim 7, further comprising a shift unit provided downstream of the sheet stacking direction of the sheet stacking apparatus, wherein the sheet stacking apparatus stacks sheets when the shift unit is switched.

  9. 9. An image forming system comprising the image forming apparatus and the sheet post-processing apparatus according to 7 or 8.

  In the present invention, the sheet is fed by the guiding means having the sheet guiding portion that is displaced to the first position where the sheet does not contact the sheet conveying surface of the roller constituting the sheet discharging means and the second position retracted from the first position. I am guiding you. Therefore, it is possible to prevent the paper from being discharged by the paper discharge means other than at the time of paper discharge, and to smoothly discharge the stacked paper, thereby enabling high-speed processing of the paper in the paper stacking unit.

It is a figure for demonstrating the problem in a paper stacking apparatus. It is a figure for demonstrating the problem in a paper stacking apparatus. 1 is a diagram illustrating an image forming system according to an embodiment of the present invention. It is front sectional drawing of the post-processing apparatus which concerns on embodiment of this invention. 1 is a front view of a paper stacking apparatus according to an embodiment of the present invention. It is a figure which shows the principal part of the paper stacking apparatus which concerns on embodiment of this invention. It is a figure which shows operation | movement of the principal part of the paper stacking apparatus which concerns on embodiment of this invention.

  The present invention will be described below based on an embodiment of the present invention, but the present invention is not limited to the embodiment.

  FIG. 3 is a diagram showing the overall configuration of the image forming system according to the embodiment of the present invention.

  The image forming apparatus A includes a rotating photoconductor 1, and further includes a charging unit 2, an image exposure unit 3, a developing unit 4, a transfer unit 5A, a charge removing unit 5B, and a separation claw 5C disposed around the photoconductor 1. And a cleaning means 6. After uniformly charging the surface of the photosensitive member 1 by the charging means 2, exposure scanning based on image data read from the document is performed by the laser beam of the image exposure means 3 to form a latent image, and the latent image is The toner image is formed on the surface of the photoreceptor 1 by reversal development by the developing means 4.

  On the other hand, an image recording sheet (hereinafter referred to as a sheet) S fed from the sheet feeding means 7A is sent to the transfer position. The toner image is transferred onto the paper S by the transfer means 5A at the transfer position. Thereafter, the charge on the back surface of the sheet S is erased by the charge removing unit 5B, separated from the photosensitive member 1 by the separation claw 5C, conveyed by the intermediate conveyance unit 7B, and subsequently heated and fixed by the fixing unit 8, and then by the sheet discharge roller 7C. Discharged.

  When image formation is performed on one side of the paper S, the transport path switching plate 7D is switched to a broken line state.

  Further, the developer remaining on the surface of the photoreceptor 1 after the image processing is removed by the cleaning unit 6 downstream of the separation claw 5C to prepare for the next image formation.

  On the other hand, when image formation is performed on both sides of the sheet S, the sheet S fixed by the fixing unit 8 is conveyed downward by switching the conveyance path switching plate 7D to the solid line state, and the reverse conveying unit 7E Switched back and upside down. A new toner image is transferred to the back side of the paper S that has been turned upside down at the transfer position. Thereafter, the sheet S is fixed in the same process as described above, passes through the conveyance path switching plate 7D switched to the broken line state, and is then discharged by the sheet discharge roller 7C.

  When performing shift processing and binding processing, which will be described later, the transport path switching plate 7D is switched to the solid line state, the paper S fixed by the fixing means 8 is transported downward, and the reverse transport means 7E is switched back to reverse the front and back. The paper is discharged by the paper discharge roller 7C.

  In any state, the paper S discharged from the paper discharge roller 7C is sent to the paper post-processing apparatus C.

  An operation unit 9 for selecting and setting an image forming mode and a paper post-processing mode is disposed on the upper front side of the image forming apparatus A. An original moving type reading method is disposed on the upper part of the image forming apparatus A. An image reading apparatus B provided with an automatic document feeder is installed.

  The sheet S introduced from the image forming apparatus A to the introduction port 10 of the sheet post-processing apparatus C is guided to the first transport path 13 or the second transport path 14 by switching the transport switching member 12 and guided to the first transport path 13. The processed paper S is discharged to the fixed paper discharge tray 50 without being post-processed, and the paper S guided to the second transport path 14 is subjected to a shift process and a binding process, which will be described later, and is moved up and down. The paper is discharged to 304. There is also a mode in which the sheet S guided to the second conveyance path 14 is discharged to the lifting / lowering tray 304 without post-processing.

  The paper S on the paper stacking unit 30 is discharged to a lifting / lowering tray 304 by a paper discharge roller 302. Further, the binding process is performed on the paper S collected in the paper stacking unit 30 by the stapler 40 (binding processing means), and the paper S after the binding process is pushed up by the paper stacking unit 30 to the lifting / lowering discharge tray 304. The paper is ejected. Reference numeral 305 denotes an alignment member that shifts the paper S discharged to the lifting / lowering tray 304.

  Shifting means for shifting the sheet S on the elevating / discharging tray 304 is configured by the two alignment members 305 disposed at the end in the width direction.

  Next, the configuration of the sheet post-processing apparatus C will be described.

  As shown in the front view of the entire sheet post-processing apparatus C in FIG. 4, the sheet post-processing apparatus C is provided with a first conveyance path 13, a second conveyance path 14, a sheet stacking unit 30, a stapler 40, and the like. The paper stacking unit 30 and the stapler units 401 and 402 constituting the stapler 40 are attached to the support plates 40A and 40A ′ to constitute a detachable unit, and the frame of the paper post-processing apparatus is formed by the support units 40B and 40C. Is attached.

  The paper stacking unit 30 will be described with reference to FIGS.

  FIG. 5 is a front view of the paper stacking unit 30. In the figure, for example, the members whose numerical values are written outside and inside the parentheses, such as the restriction member 360 (361), indicate a plurality of members provided in parallel in the width direction perpendicular to the sheet conveyance direction.

  The sheet stacking unit 30 includes support plates 33A and 33B that constitute an inclined sheet support base, a timing belt 34 stretched around pulleys 39 and 391, a first stop member 411, a second stop member 41, and a regulating member 360. , 361 and the like. The pulley 391 is driven and rotated by the motor M6 to drive the timing belt 34. The first stop member 411 is driven by a motor (not shown) and is attached to the frame of the support plates 40A and 40A 'so as to be rotatable between a standing position and a lying position. On the other hand, the second stop member 41 is fixed to the timing belt 34.

  The pulley 39 is fixed to a rotatable shaft 37C.

  Restricting members 360 and 361 for restricting the position in the width direction are provided on both sides in the width direction of the paper stacking unit 30 to restrict the side edges of the paper S.

  Driven rollers 32A and 32B are provided facing the driving rollers 37A and 37B. The driven roller 32A faces the driving roller 37A, and the driven roller 32B faces the driving roller 37B. The driven roller 32A and the driving roller 37A, and the driven roller 32B and the driving roller 37B constitute a pair of rollers, respectively, and the pair of rollers constitute a paper discharge unit that discharges the paper S from the paper stacking unit 30.

  In FIG. 5, a solenoid 31 is fixed to a rotatable support member 311 and a support lever 314 is rotatably provided. The support lever 314 supports the shafts of the driven rollers 32A and 32B. A plunger 315 of the solenoid 31 is coupled to the support lever 314. 31S is a coil spring that urges the plunger 315 in the pushing direction (left direction). The support lever 314 is rotatably supported by the support member 311 by the shaft 313 and rotates according to the operation of the plunger 315. When the solenoid 31 is off, the plunger 315 is pushed by the coil spring 31S and moves to the left, and the driven rollers 32A and 32B come into contact with the driving rollers 37A and 37B, respectively. When the solenoid 31 is turned on, the plunger 315 moves to the right, and the driven rollers 32A and 32B are displaced to the solid line positions, respectively, and are separated from the driving rollers 37A and 37B.

  The operation of the sheet post-processing apparatus C having the above configuration will be described.

The paper transport / processing modes in the paper post-processing apparatus C include the following.
a. Non-processing mode The sheet S is discharged to the fixed discharge tray 50 through the first conveyance path 13.

In this mode, a small number of sheets S are discharged without post-processing.
b. Non-Processing Mode The sheet S is discharged to the lifting / discharging tray 304 by the discharge roller 302 through the second conveyance path 14.

  The lifting / lowering tray 304 is lowered according to the amount of paper, and the surface of the sheet S on the lifting / lowering tray 304 is always maintained at a constant height.

The paper S is discharged from the second transport path 14 to the paper stacking unit 30 by the paper discharge roller R4, and is transported from the paper stacking unit 30 by the driven rollers 32A and 32B and the driving rollers 37A and 37B. It is discharged by.
c. Shift processing mode The paper S is discharged from the second transport path 14 to the paper stacking unit 30 by the paper discharge roller R4, transported from the paper stacking unit 30 by the driven rollers 32A and 32B, and the driving rollers 37A and 37B. The paper is discharged by the paper roller 302. The shift process is performed by the regulating members 360 and 361 and further aligned by the alignment plate 305.

  In the shift processing mode, as described below, the sheets S are stacked on the sheet stacking unit 30 when shifting to the next shift unit of one shift unit.

  That is, a predetermined length of time is required to move the alignment member 305 and switch the paper stacking position in the width direction. In this switching time, the sheets S are stacked in the sheet stacking unit 30 in order to make the transported sheets S wait in the sheet post-processing apparatus C.

  In this stacking, the paper S discharged from the paper discharge roller R4 to the paper stacking unit 30 hits the stop member 411 and stops.

  In the shift process, two or three sheets are stacked on the sheet stacking unit 30. The accumulated sheets S are conveyed by the driving rollers 37A and 37B and the driven rollers 32A and 32B. The paper is discharged to the lift paper discharge 304.

d. Staple Mode The sheets S sent to the sheet post-processing apparatus C are stacked on the sheet stacking unit 30 so as to form a staple unit. In this case, the sheet S hits the stop member 41 and stops. Each time one of the sheets S is introduced into the sheet stacking unit 30, the regulating members 360 and 361 are operated to align the sheets. When the set number of sheets are stacked, the stapler 40 operates to bind the sheets S.

  The bundle of sheets S subjected to the binding process is pushed up to the upper left on the sheet stacking unit 30 by the stop member 41 and is discharged to the lift sheet discharge tray 304. In discharging to the lifting tray 304, the support member 311 rotates, the driven rollers 32A and 32B are greatly separated from the driving rollers 37A and 37B, and the upper roller of the discharging roller 302 is displaced upward as indicated by a dotted line. Then, the bundle of sheets S is discharged through a gap between the spaced discharge rollers 302.

  In the shift processing mode, as described above, in order to switch the alignment member 305, two or three sheets S are stacked on the sheet stacking unit 30, and a plurality of stacked sheets S are discharged. Paper.

  The operation of the sheet stacking unit 30 in such shift processing will be described with reference to FIGS.

  FIG. 6 shows a main part for introducing paper into the paper stacking unit 30 and discharging the paper from the paper stacking unit. FIG. 7 shows introducing paper into the paper stacking unit 30 and feeding paper from the paper stacking unit. It is a figure which shows operation | movement of the said principal part discharged.

  Guide members 38A and 38B are disposed on both sides in the width direction of the drive roller 37A, and guide members 38C and 38D are disposed on both sides in the width direction of the drive roller 37B. The guide members 38A to 38D constitute guide means for guiding the paper when the paper is introduced, and are made of a material having low frictional resistance, for example, POM (polyacetal resin). The guide members 38A to 38D are urged by a spring (not shown) so as to rotate in a clockwise direction indicated by an arrow in FIG. The guide members 38A to 38D are in contact with the jaw shaft 37C, and the guide members 38A to 38D are locked in the state shown in FIG. In the state shown in FIG. 6, the height (first position) of the paper guide surfaces of the paper guide portions 381A to 381D of the guide members 38A to 38D is less than the height of the paper transport surfaces of the drive rollers 37A and 37B. About 5 mm higher.

  The drive rollers 37A and 37A are always rotated through a paper introduction stage and a paper discharge stage described below.

  In the paper introduction stage where the paper S is discharged from the paper discharge roller R4 and the paper introduction stage where the rear end of the paper S passes through the paper discharge roller R4 and falls on the support plates 33A and 33B, the solenoid 31 is turned on. The driven rollers 32A and 32B and the drive rollers 37A and 37B are separated from each other. That is, the driven rollers 32A and 32B are at the positions indicated by the solid lines in FIG.

  The sheet S travels while being guided by the guide members 38A to 38D without contacting the drive rollers 37A and 37B. Therefore, when the paper is introduced, the paper S is not conveyed and discharged by the drive rollers 37A and 37B.

  In the paper discharge stage where the paper S is discharged from the paper stacking unit 30, the solenoid 31 is turned off, so that the driven rollers 32A and 32B move to positions indicated by chain lines and come into contact with the drive rollers 37A and 37B. Due to the displacement of the driven rollers 32A and 32B, as shown in FIG. 7B, the sheet S comes into contact with the drive rollers 37A and 37B. Also, as shown in FIG. 7B, the guide members 38A to 38D are pushed by the paper S, and these paper guide surfaces are the same height (second position) as the paper transport surfaces of the drive rollers 37A and 37B. ).

  In the state of FIG. 7B, the paper S is nipped and conveyed by the driving rollers 37 </ b> A and 37 </ b> B and the driven rollers 32 </ b> A and 32 </ b> B, and is discharged from the paper stacking unit 30.

  The paper S is conveyed and discharged by the drive rollers 37A and 37B rotating in the direction indicated by the arrow in FIG. In this paper discharge operation, since the guide members 38A to 38D are retracted, they do not act as a transport resistance on the paper S.

  Therefore, the conveyance and discharge of the paper S are performed smoothly, and it is possible to prevent the occurrence of a jam and the misalignment of a plurality of sheets.

  In the embodiment described above, the driven rollers 32A and 32B are used as the displacement means for retracting the guide means, and the guide means is retracted by being pushed by the driven rollers 32A and 32B. However, in the paper discharge stage, a separate displacement means for displacing the guide means to the retracted position is provided, and the paper guide surface of the guide means is displaced below the height of the paper transport surface of the paper discharge means by the separate provided displacement means. May be. Further, in the present embodiment, the guide members 38A to 38D are configured to be positioned at the same height as the paper transport surfaces of the drive rollers 37A and 37B via the paper S at the paper discharge stage. However, the height of the paper guide surfaces of the paper guide portions 381A to 381D is lower than the first position where the paper is not brought into contact with the driving rollers 37A and 37B, so that it does not substantially affect the paper discharge. For example, it may be configured to be positioned somewhat above the sheet conveyance surface.

A image forming apparatus C sheet post-processing apparatus 30 sheet stacking unit 33A, 33B support plate 34 timing belt 40 stapler 32A, 32B driven roller 37A, 37B drive roller 38A-38D guide member

Claims (9)

A sheet support that is disposed at an angle and supports a sheet; a sheet discharge unit that is disposed on an upper portion of the sheet support; and includes a pair of rollers that can contact and separate from each other;
A guide means having a paper guide section for guiding paper,
The guide means is displaced to a first position where the paper on the paper guide portion is not brought into contact with one paper transport surface of the pair of rollers, and a second position retracted from the first position. Paper stacking device. The guide means is characterized in that the paper guide portion is displaced to the first position higher than the paper transport surface and the paper guide portion is displaced to the second position that is the same as or lower than the paper transport surface. The paper stacking apparatus according to claim 1. The sheet guide section is located at the first position when the pair of rollers are separated from each other, and the guide means is operated at the second position when the pair of rollers are in contact with each other. The paper stacking apparatus according to claim 1, wherein the paper stacking apparatus is a paper stacking apparatus. 4. The paper stacking apparatus according to claim 3, wherein the paper guide unit is pushed by the paper and retracts to the second position when the pair of rollers contact with each other through the paper. The paper stacking apparatus according to claim 1, further comprising a displacement unit that retracts the guide unit to the second position. 6. The paper stacking apparatus according to claim 5, wherein the other of the pair of rollers constitutes the displacement unit. A sheet post-processing apparatus comprising the sheet stacking apparatus according to claim 1. 8. The sheet post-processing apparatus according to claim 7, further comprising shift means provided downstream of the sheet stacking direction of the sheet stacking apparatus, wherein the sheet stacking apparatus stacks sheets when the shift means is switched. . An image forming system comprising the image forming apparatus and the sheet post-processing apparatus according to claim 7.

Images