JP2013230893A - Sheet processing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing device capable of reducing a binding processing time without degrading the quality of a product, and to provide an image forming device.SOLUTION: A front alignment plate 340 and a rear alignment plate 341 are provided on a sheet stacking part movably in the cross direction for restricting both side end positions in the cross direction of sheets S carried to the sheet stacking part in sequence, respectively, and a stapler 132 is used for performing binding processing at two or more positions of a bunch of sheets Sa on the sheet stacking part, both side end positions of which are restricted by the front alignment plate 340 and the rear alignment plate 341, respectively. Then, a control part controls a first drive part so that, during a time when the stapler 132 finishes the binding processing at the first position and to a time when it is moved to the second binding position to perform the binding processing, the rear alignment plate 341 on the side near the first binding position out of the front alignment plate 340 and the rear alignment plate 341 moves the bunch of sheets Sa in the cross direction.

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus, and more particularly to an apparatus in which a sheet bundle is transported while being shifted in the width direction after binding processing is performed at two or more positions on the sheet bundle.

  2. Description of the Related Art Conventionally, some image forming apparatuses such as a copying machine, a laser beam printer, a facsimile, and a composite machine of these include a sheet processing apparatus that performs a binding process on a sheet on which an image is formed. In this sheet processing apparatus, an intermediate processing tray is provided in the apparatus, a plurality of sheets are stacked on the intermediate processing tray to form a sheet bundle, and binding processing is performed on the sheet bundle by a binding unit. Yes.

  As such a sheet processing apparatus, there is one that performs stapling processing (binding processing) at one place or two or more places on a sheet bundle. FIG. 17 is a diagram for explaining the operation of the conventional sheet processing apparatus in the two-position binding mode. The sheets S conveyed from the image forming apparatus (not shown) are not printed one by one in a state where the center in the width direction orthogonal to the conveyance direction of the sheet S coincides with the center position of the conveyance guide (not shown), so-called center reference. It is conveyed to the illustrated intermediate processing tray.

  Next, the sheet S conveyed on the basis of the center by the aligning operation of the aligning plates 1141 and 1142 waiting at the positions retracted to the outside in the width direction by a predetermined amount from both ends in the width direction of the sheet S Alignment is performed while moving to a first alignment position that is shifted from the position by a predetermined amount. After that, the alignment plates 1141 and 1142 return to a position where they are retracted by a predetermined amount from the end portion of the transport sheet in preparation for a subsequent sheet that is subsequently transported on the center reference, and wait. When the subsequent sheet is conveyed, the subsequent sheet is aligned together at the same position as the preceding sheet while moving again to the first alignment position. By repeating this operation, the sheet bundle Sa is formed while moving and aligning the sheets to the first alignment position.

  Next, when the predetermined number of sheets S are conveyed and aligned, the waiting stapler 1101 first staples the first position (X1), and then the rear end of the sheet is substantially parallel to the arrow direction. To the second position (X2). When the two-point binding is completed, the sheet bundle is conveyed to a stacking tray (not shown). The subsequent sheet bundle is aligned and stapled at a second alignment position that is deviated by a predetermined amount in the opposite direction from the center position of the conveyance guide with respect to the first alignment position where the preceding sheet bundle is aligned. To be transported. As a result, the sheet bundle is stacked on the stacking tray in a state of being sorted for each sheet bundle.

  By the way, in the conventional sheet processing apparatus, the sheet bundle is formed by aligning each sheet at the center position of the conveyance guide, and then the first position binding process is performed. Some are moved to the second alignment position (see Patent Document 1). In such a sheet processing apparatus, for example, as shown in FIG. 17, the stapler 1101 starts to move to the second binding position as indicated by the arrow, and at the same time, the sheet bundle Sa is stapled by the alignment plates 1141 and 1142. It is moved by a predetermined amount L3 in the direction opposite to the moving direction. With this configuration, it is possible to shorten the binding processing time as compared with the case where the binding process is performed after the sheet is moved to the first or second alignment position for each sheet by the alignment unit. .

Japanese Patent Laid-Open No. 2001-220055

  However, in such a conventional sheet processing apparatus, when the sheet bundle is moved in the direction opposite to the stapler moving direction, the sheet bundle is opposed to the alignment plate on the first binding position side of the sheet bundle Sa. It is moved by the alignment plate 1141. Here, as physical factors that affect the behavior of the sheet when the sheet bundle is moved, (1) sheet stiffness (elasticity) T, (2) sheet surface friction coefficient μ, and (3) sheet weight N Is mentioned.

  As factors determining the sheet stiffness T in (1), there are an internal factor possessed by the sheet itself and an external factor imparted externally to the sheet. The internal factors include the sheet thickness, the curl amount, the moisture retention moisture amount, the gap direction, the air permeability, the sheet length (beam length), and the like. Generally, the sheet thickness is thin, the edge curl amount is large, the moisture retention amount is large, the gap direction perpendicular to the sheet moving direction, the air permeability is low, the sheet length The longer the length (= free long distance), the weaker the sheet. Further, as external factors, there are a moving pressure for moving the sheet, a pressing direction, and a distance from the restraint point. As the moving pressure is higher, the pressurizing direction is larger with respect to the surface, and the distance from the restraint point (= free long distance) is larger, the stiffness of the sheet becomes weaker.

  Factors of the sheet surface friction coefficient μ in (2) include the smoothness of the sheet itself, the surface smoothness of the tray supporting the sheet, and the toner concentration transferred to the sheet. Generally, the frictional resistance μ tends to increase as the degree of smoothness decreases (= surface irregularities are large) and the density of toner to be transferred decreases.

  The sheet weight N in (3) is attributed to the basis weight of the sheet, the number of sheet bundles, the moisture retaining moisture amount of the sheet, and the like. In order to move the sheet bundle, it is necessary that the movement resistance force F (F = μ · N) of the sheet and the acting pressing force P for moving the sheet have a relationship of F <P. In addition, when the movement resistance force F and the sheet stiffness (koshi) T have a relationship of T> F, the sheet moves without bending, but when the relationship of T <F is satisfied, the sheet bundle is Bends without moving. Further, as another factor of the movement resistance force F, there is a charged potential amount on the sheet surface. If the sheet potential polarity and the tray potential polarity are charged in a counter electrode relationship, the movement resistance force F increases.

  By the way, when the sheet bundle is moved by the alignment plate, as shown in FIG. 18, an acting pressing force P for moving the bundle from the restraint point of the sheet bundle Sa corresponding to the first binding portion of the sheet bundle Sa. The distance (= free long distance) to the alignment plate 1141 to which is given increases. In this case, depending on the above-described physical factor conditions, the sheet bundle Sa is likely to buckle between the first binding position and the alignment plate 1141, and the entire bundle is likely to bend.

  As a result, the sheet bundle Sa cannot be accurately moved to the second binding position. In this case, the second binding position is displaced at the second binding position in a state where the second binding position is deviated, or the sheet is buckled or bent during the movement, or the bending is generated between the binding positions. Therefore, the quality of the bound product is reduced. Further, since the sheet bundle and the stapler are respectively moved in the opposite directions, the movement resistance of the clinch opening portion of the stapler during movement of the bundle is increased, and hence the bending of the bundle accompanying the movement of the sheet bundle is more likely to occur.

  Accordingly, the present invention has been made in view of such a current situation, and provides a sheet processing apparatus and an image forming apparatus that can shorten the binding processing time without deteriorating the quality of a product. It is the purpose.

  In the sheet processing apparatus, the sheet stacking unit that sequentially stacks the sheets to be conveyed, and the sheet stacking unit are provided so as to be independently movable in a width direction orthogonal to the sheet conveying direction. A first aligning plate and a second aligning plate that regulate the positions of both side edges in the width direction of the sheets sequentially conveyed to the first portion, and a first drive unit that moves the first aligning plate and the second aligning plate in the width direction, respectively. And a binding unit that is provided so as to be movable in the width direction, and that performs binding processing at two or more locations on the sheet stacking unit on the sheet stacking unit, the positions of both side ends of which are regulated by the first alignment plate and the second alignment plate, A second driving unit that moves the binding unit in the width direction; and after the binding unit finishes the first binding process, the first alignment is performed until the binding unit moves to the second binding position and performs the binding process. Of the plate and the second alignment plate, the first location Flip is characterized in that it comprises a control unit for controlling the second driving portion and the first driving unit to move the sheet bundle in the width direction by one of the aligning plate close to the position.

  Like the present invention, by moving the sheet bundle in the width direction by the alignment plate on the side close to the first binding position before the binding unit moves to the second binding position and performs the binding process, The binding processing time can be shortened without degrading the quality of the deliverables.

1 is a diagram illustrating a configuration of an image forming apparatus including a sheet processing apparatus according to an embodiment of the present invention. The figure which shows the structure of the finisher which is the said sheet processing apparatus. The figure explaining the structure of the intermediate process tray provided in the said finisher. The figure explaining the moving mechanism of the stapler provided in the finisher. FIG. 2 is a control block diagram of the image forming apparatus. FIG. 3 is a control block diagram of the finisher. The figure explaining the structure of the front and back alignment part provided in the said intermediate processing tray. The figure explaining the structure of the drawing paddle and stopper provided in the said intermediate processing tray. The figure explaining the operation | movement at the time of the unbound binding sort mode of the said finisher. The 1st figure explaining operation | movement in the one place binding mode of the said finisher. The 2nd figure explaining operation | movement in the one place binding mode of the said finisher. The flowchart which shows the control in the one place binding mode of the said finisher. The 1st figure explaining operation | movement at the time of the two place binding mode of the said finisher. The 1st flowchart which shows the control at the time of the two place binding mode of the said finisher. The 2nd flowchart which shows the control at the time of the two place binding mode of the said finisher. The 2nd figure explaining operation | movement at the time of the two place binding mode of the said finisher. The figure which shows the structure of the conventional sheet processing apparatus. The figure explaining the subject of the conventional sheet processing apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of an image forming apparatus including a sheet processing apparatus according to an embodiment of the present invention. In FIG. 1, 600 is an image forming apparatus, 602 is an image forming apparatus main body (hereinafter referred to as apparatus main body), 650 is a document reading unit (image reader) provided on the upper part of the apparatus main body 602, and 651 is a plurality of documents automatically. This is a document conveying device for automatically reading.

  The apparatus main body 602 includes paper cassettes 909a and 909b on which normal sheets S for image formation are stacked, an image forming unit 603 that forms a toner image on a sheet using an electrophotographic process, and a toner image formed on the sheet. A fixing unit 904 and the like are provided. Further, an operation unit 601 is connected to the upper surface of the apparatus main body 602 so that the user can perform various inputs / settings on the apparatus main body 602, and a finisher 100 that is a sheet processing apparatus is connected to the side of the apparatus main body 602. Yes. A CPU circuit unit 630 is a control unit that controls the apparatus main body 602 and the finisher 100.

  In such an image forming apparatus 600, when an image of a document (not shown) is formed on a sheet, first, an image sensor transported by the document transport device 651 is used as an image sensor provided in the document reading unit 650. Read by 650a. Thereafter, the read digital data is input to the exposure unit 604, and the exposure unit 604 irradiates light corresponding to the digital data to the photosensitive drum 914 (914a to 914d) provided in the image forming unit 603. When light is irradiated in this way, an electrostatic latent image is formed on the surface of the photosensitive drum, and by developing the electrostatic latent image, toner images of colors of yellow, magenta, cyan, and black are formed on the surface of the photosensitive drum. Is formed.

  Next, the four color toner images are transferred onto the sheet fed from the sheet feeding cassettes 909 a and 909 b, and then the toner image transferred onto the sheet is permanently fixed by the fixing unit 904. If the toner image is fixed in this way and the mode is to form an image on one side of the sheet, the sheet is conveyed as it is from the conveying roller pair 907 to the finisher 100.

  In the mode in which images are formed on both sides of the sheet, the sheet is transferred from the fixing unit 904 to the reversing roller 905, and then the reversing roller 905 is reversed at a predetermined timing so that the sheet is conveyed to the duplex conveying rollers 906a to 906f. Transport in the direction of. Thereafter, the sheet is conveyed again to the image forming unit 603, and toner images of four colors of yellow, magenta, cyan, and black are transferred to the back surface. Note that the sheet having the four color toner images transferred on the back side is conveyed again to the fixing unit 904 to fix the toner image, and then conveyed from the conveying roller pair 907 to be side portions of the apparatus main body 602. The finisher 100 is connected to the finisher 100.

  The finisher 100 sequentially takes sheets conveyed from the apparatus main body 602, aligns a plurality of fetched sheets and bundles them into one bundle, and performs a punching process that forms a hole near the rear end of the fetched sheets. ing. Further, the finisher 100 is configured to perform processing such as stapling processing (binding processing) and bookbinding processing for stapling the rear end side of the sheet bundle. The stapler 100A for stapling the sheet and the sheet bundle are folded in two. A saddle unit 135 for bookbinding is provided.

  As shown in FIG. 2, the finisher 100 includes an entrance roller pair 102 for taking a sheet into the apparatus, and the sheet discharged from the apparatus main body 602 is delivered to the entrance roller pair 102. At this time, the sheet delivery timing is also detected by the entrance sensor 101 at the same time. Thereafter, the sheet conveyed by the inlet roller pair 102 passes through the conveyance path 103 and the edge position of the sheet is detected by the lateral registration detection sensor 104, and how much is the center (center) position of the finisher 100, It is detected whether a deviation in the width direction has occurred. In addition, after such a shift in the width direction (hereinafter referred to as a lateral registration error) is detected, the shift unit 108 is moved forward or backward while the sheet is being conveyed to the shift roller pair 105, 106. The sheet shift operation is performed by moving the predetermined amount.

  Next, the sheet is conveyed by the conveyance roller 110 and the separation roller 111 and reaches the buffer roller pair 115. Thereafter, when the paper is discharged to the upper tray 136, the upper path switching member 118 is moved clockwise by driving means such as a solenoid (not shown). As a result, the sheet is guided to the upper path conveyance path 117 and conveyed to the upper tray 136 by the upper discharge roller 120. When the sheet is not conveyed to the upper tray 136, the sheet conveyed by the buffer roller pair 115 is guided to the bundle conveyance path 121 by the upper path switching member 118 in the state indicated by the solid line. Thereafter, the sheet passes through the conveyance path sequentially by the conveyance roller 122 and the bundle conveyance roller pair 124.

  Next, when the conveyed sheet is conveyed to the lower stacking tray 137 as a sheet stacking unit, the sheet is conveyed to the lower path 126 by the saddle path switching member 125 in the state shown by the solid line. Thereafter, the sheet is conveyed to the intermediate processing tray 138 by the lower discharge roller pair 128. Then, the conveyed sheets are aligned while sequentially stacking the sheets by a return means such as a paddle 131 and a belt roller 158, and the sheet is stacked on an intermediate processing tray for performing processing on the aligned and stacked sheet bundle (sheet stacking). A predetermined number of sheets is aligned.

  Next, the sheet bundle thus aligned on the intermediate processing tray is subjected to a binding process by a stapler 132 constituting a binding unit as necessary, and thereafter a lower stacking tray by a bundle conveying roller pair 130. The paper is discharged to 137. The stapler 132 is movable in a direction orthogonal to the sheet conveyance direction (hereinafter referred to as a depth direction), and can bind one or more places at the rear end of the sheet bundle.

  On the other hand, when the sheet is subjected to saddle (saddle stitching) processing, the saddle path switching member 125 is moved counterclockwise by driving means such as a solenoid (not shown). As a result, the sheet is conveyed to the saddle path 133, guided to the saddle unit 135 by the pair of saddle entrance rollers 134, and subjected to saddle processing (saddle stitching processing).

  Here, the stapler 132 as a binding unit is to bind the end portion of the sheet bundle by a clinch motor M132 shown in FIG. 6 to be described later, and is fixed on the slide support 303 shown in FIG. As shown in FIG. 4, rolling rollers 304 and 305 are provided below the slide support 303. The slide support 303 is guided by the rolling rollers 304 and 305 and the guide rail groove 307 on the stapler moving table, and the sheets stacked on the intermediate processing tray 138 by a stapler moving motor M303 shown in FIG. It moves in the direction of arrow Y along the rear edge.

  The stapler 132 is maintained in a posture inclined by a predetermined angle α with respect to the trailing edge of the sheet at the corner of the sheet S stacked on the intermediate processing tray 138. The inclination angle α is set to about 30 degrees, but can be changed by changing the shape of the guide rail groove 307. Further, the stapler moving base 306 is provided with a stapler home sensor S303 shown in FIG. 6 described later for detecting the home position of the stapler 132. Normally, the stapler 132 stands by at the home position on the front side of the apparatus. In the present embodiment, the binding mode by the stapler 132 includes a one-point binding mode for binding one place of the sheet bundle and a two-position binding mode for binding two places of the sheet bundle.

  FIG. 5 is a control block diagram of the image forming apparatus 600. In FIG. 5, reference numeral 630 denotes a CPU circuit unit disposed at a predetermined position of the apparatus main body 602 as shown in FIG. The CPU circuit unit 630 includes a CPU 629, a ROM 631 that stores control programs and the like, an area for temporarily storing control data, and a RAM 660 that is used as a work area for computations associated with control.

  In FIG. 5, reference numeral 637 denotes an external interface between the image forming apparatus 600 and an external PC (computer) 620. When the external interface 637 receives print data from the external PC 620, the external interface 637 develops the data into a bitmap image and outputs it as image data to the image signal control unit 634.

  The image signal control unit 634 outputs the data to the printer control unit 635, and the printer control unit 635 outputs the data from the image signal control unit 634 to an exposure control unit (not shown). Note that the image of the original read by the image sensor 650a (see FIG. 1) is output from the image reader control unit 633 to the image signal control unit 634, and the image signal control unit 634 outputs the image output to the printer control unit 635. Output.

  The operation unit 601 includes a plurality of keys for setting various functions relating to image formation, a display unit for displaying a setting state, and the like. Then, a key signal corresponding to the operation of each key by the user is output to the CPU circuit unit 630, and corresponding information is displayed on the display unit based on the signal from the CPU circuit unit 630.

  The CPU circuit unit 630 controls the image signal control unit 634 according to the control program stored in the ROM 631 and the setting of the operation unit 601, and controls the document conveying device 651 (see FIG. 1) via the document conveying device control unit 632. Control. Further, the document reading unit 650 (see FIG. 1) via the image reader control unit 633, the image forming unit 603 (see FIG. 1) via the printer control unit 635, and the finisher 100 via the finisher control unit 636, respectively. Control.

  In the present embodiment, the finisher control unit 636 is mounted on the finisher 100 and performs drive control of the finisher 100 by exchanging information with the CPU circuit unit 630. Alternatively, the finisher control unit 636 may be disposed integrally with the CPU circuit unit 630 on the apparatus main body side, and the finisher 100 may be directly controlled from the apparatus main body side.

  FIG. 6 is a control block diagram of the finisher 100 according to the present embodiment. The finisher control unit 636 includes a CPU (microcomputer) 701, a RAM 702, a ROM 703, an input / output unit (I / O) 705, a communication interface 706, a network interface 704, and the like.

  Further, a conveyance control unit 707, an intermediate processing tray control unit 708 and a binding control unit 709 are connected to the input / output unit (I / O) 705. The conveyance control unit 707 controls sheet lateral registration detection processing, sheet buffering processing, and conveyance processing. The intermediate processing tray control unit 708 performs drive control of a front alignment plate motor M340, a back alignment plate motor M341, a paddle drive motor M155, a bundle discharge drive motor M130, and the like which will be described later.

  The intermediate processing tray controller 708 is connected to a front alignment plate home sensor S340, a back alignment plate home sensor S341, a paddle drive home sensor S155, and the like, which will be described later. The intermediate processing tray control unit 708 performs later-described alignment plate operation control, pull-in paddle operation control, and swing guide opening / closing control by a home position detection sensor and a moving motor, respectively. The binding control unit 709 performs drive control of the clinch motor M132, the stapler moving motor M303 that is the second driving unit, and the binding control unit 709 is connected to a needle presence sensor S7, a stapler home sensor S303, and the like. ing.

  Next, the configuration of the staple unit 100A provided with the intermediate processing tray 138 will be described. As shown in FIG. 3, the intermediate processing tray 138 is arranged with the downstream side (left side in FIG. 3) inclined upward and the upstream side (right side in FIG. 3) inclined downward with respect to the sheet bundle conveyance direction. A rear end stopper 150 is disposed at a lower end portion on the upstream side of the intermediate processing tray 138. The intermediate processing tray 138 may be horizontal.

  As shown in FIG. 7, front and back aligning portions 340 </ b> A and 341 </ b> A as shown in FIG. 7 are provided in the intermediate portion of the intermediate processing tray 138. Is provided. Here, the front and back alignment portions 340A and 341A independently drive the front and back alignment plates 340 and 341 having the alignment portions 340a and 341a constituting the alignment surface, and the front and back alignment plates 340 and 341, respectively. Front and back alignment plate motors M340 and M341 are provided.

  Then, when restricting the positions of both side edges of the sheet, the driving of the front and back alignment plate motors M340 and M341 as the first drive unit is transmitted to the front and back alignment plates 340 and 341 via the timing belts B340 and B341. To do. As a result, the front and back alignment plates 340 and 341 move independently along the width direction with respect to the intermediate processing tray 138, and come into contact with both side edges of the sheets stacked on the intermediate processing tray 138 so that the sheets are moved. Align.

  That is, the front alignment plate 340 as the second alignment plate and the back alignment plate 341 as the first alignment plate are disposed on the intermediate processing tray 138 with the alignment portions (alignment surfaces) 340a and 341a facing each other, and It is assembled so that it can move forward and backward in the alignment direction. As a result, even when the sheet (or sheet bundle) is shifted and conveyed in the width direction, the position of the sheet on the intermediate processing tray 138 can be aligned by the front and back alignment plates 340 and 341.

  By the way, one alignment plate, for example, an alignment portion 340a constituting an alignment surface of the front alignment plate 340 is provided to be movable in the width direction. A spring 345 that is elastically deformed is provided between the alignment portion 340a and the main body 340b of the front alignment plate 340. The aligning portion 340a protrudes by a predetermined amount L toward the sheet side, that is, the back aligning plate 341 that serves as a reference for alignment, by the moving links 346 and 347 that form the pressure contact portion together with the spring 345. .

  As will be described later, when the side edge position of the sheet is regulated, when the aligning portion 340a is pressed against the sheet, the aligning portion 340a, which is the aligning surface, moves toward the main body 340b while resisting the spring 345. Further, when the aligning portion 340a moves away from the pressed sheet, the alignment surface gradually moves while eliminating the bending of the pressed sheet until the length of the spring 345 is restored even if the main body 340b moves. It becomes like this. By configuring in this way, it is possible to prevent the alignment position from being shifted due to the restoring force due to abrupt elimination of the bending of the sheet.

  In FIG. 7, S340 and S341 are front and back alignment plate position sensors, and the front and back alignment plate position sensors S340 and S341 respectively provide home positions (HP) of the front and back alignment plates 340 and 341. Is detected. By providing such front and back alignment plate position sensors S340 and S341, when not operating, the front and back alignment plates 340 and 341 stand by at their home positions set at both ends, respectively. Can be made. Here, the home positions of the front and back alignment plates 340 and 341 are positions that do not hinder the conveyance of the sheet onto the intermediate processing tray 138.

  Further, as shown in FIG. 3, a pull-in paddle 131 and a swing guide 149 are disposed at the upper end portion on the downstream side in the pull-in direction of the intermediate processing tray 138. Here, a plurality of pull-in paddles 131 are disposed above the intermediate processing tray 138, and a plurality of pull-in paddles 131 are fixed along a drive shaft 157 rotated by a paddle drive motor M155 shown in FIG. Then, the paddle drive motor M155 rotates counterclockwise in FIG. 3 at an appropriate timing.

  In FIG. 3, reference numeral 100 </ b> C denotes a sheet rear end alignment unit that is a conveyance direction alignment unit that aligns positions in the sheet conveyance direction. The sheet trailing edge aligning portion 100C includes a belt roller 158, a trailing edge lever 159, and a trailing edge stopper 150 (150a to 150c) that is a regulating member that comes into contact with the upstream edge in the sheet conveyance direction, as shown in FIG. It has.

  Then, the sheet conveyed from the lower discharge roller pair 128 onto the intermediate processing tray is stacked on the intermediate processing tray 138 or on the intermediate processing tray 138 by the inclination of the intermediate processing tray 138 and the action of the pull-in paddle 131. Glide down on the finished sheet. The sheet sliding down in this way is then guided by the rear end lever 159 by the counterclockwise rotation of the belt roller 158, and the rear end stopper 150 (150a to 150c) whose rear end (upstream end in the conveying direction) is a stopper. ) And stop.

  Thereby, the position in the sheet conveying direction is aligned. In the present embodiment, the rear end stoppers 150a and 150b located on both sides in the width direction are movable in the width direction by a drive unit (not shown), and the center rear end stopper located in the center. 150c does not move in the width direction.

  Here, the belt roller 158, which is an endless belt, is provided so as to be movable up and down (movable) above the intermediate processing tray 138, and is a first transport roller that constitutes the lower discharge roller pair 128 shown in FIG. It is wound around the outer periphery of 128a. Then, the lower portion is rotated in the counterclockwise direction following the rotation of the first conveying roller 128a in such a positional relationship that the lower portion contacts the uppermost sheet stacked on the intermediate processing tray 138. As a result, the sheet conveyed on the intermediate processing tray 138 is conveyed in the direction opposite to the conveyance direction and abuts against the trailing edge stopper 150.

  The belt roller 158 is provided above the intermediate processing tray 138 in such a positional relationship that the lower portion thereof is in contact with the uppermost sheet stacked on the intermediate processing tray 138. The belt roller 158 is hung on the outer periphery of the first paper discharge roller 128a constituting the lower paper discharge roller pair 128, and rotates counterclockwise following the rotation of the first paper discharge roller 128a.

  On the other hand, the swing guide 149 constituting the sheet conveyance unit rotatably supports the upper conveyance roller 130b constituting the bundle conveyance roller pair 130 together with the lower conveyance roller 130a provided at the downstream end of the intermediate processing tray 138. ing. As the swing guide 149 swings, the upper transport roller 130b comes into contact with the lower transport roller 130a. Note that a bundle conveyance roller pair 130 (for example, the lower conveyance roller 130a), which is a conveyance roller pair, is rotated forward and backward by a bundle discharge driving motor M130 (see FIG. 6).

  The swing guide 149, which is a holding member that holds the upper transport roller 130b, which is one roller of the bundle transport roller pair 130, is driven in the vertical direction with the support shaft 154 as a fulcrum by driving from the swing guide opening / closing motor 180. To swing. Normally, when the sheet is conveyed onto the intermediate processing tray 138, the sheet is swung upward, and accordingly, the upper conveying roller 130b is separated from the lower conveying roller 130a that is the other roller of the bundle conveying roller pair 130. It becomes an open state.

  When the processing of the sheet on the intermediate processing tray 138 is completed, the swing guide 149 swings downward, and the sheet bundle is sandwiched between the upper transport roller 130b and the lower transport roller 130a. After that, the bundle conveying roller pair 130 rotates while the sheet bundle is sandwiched between the upper conveying roller 130b and the lower conveying roller 130a as described above, whereby the sheet bundle is conveyed to the lower stacking tray 137.

  Further, the swing guide 149 is provided with a guide guide 151 that is positioned upstream of the upper conveying roller 130b and guides the sheet to the roller nip portion of the upper conveying roller 130b. The swing guide 149 includes a first static elimination needle 152 that removes the surface charge of the sheet when the sheet is discharged from the lower discharge roller pair 128 into the intermediate processing tray 138 in the axial direction. ing. Further, a second static elimination needle 153 that is located downstream of the upper conveying roller 130b and removes the surface charge of the sheet conveyed by the bundle conveying roller pair 130 is disposed in the swing guide 149 in the axial direction. ing.

  Next, the operation of the finisher 100 configured as described above in the unbound sort mode and the staple sort mode will be described. First, the operation in the unbound sort mode will be described with reference to FIG.

  When a job in the unbound sort mode is selected, the sheet from the apparatus main body 602 passes through the entrance roller pair 102, the shift roller pairs 105 and 106, the conveyance roller 110, the separation roller 111, and the buffer roller pair 115, and is shown in FIG. The paper is conveyed to the paper discharge roller pair 128. Next, after the sheet is conveyed onto the intermediate processing tray 138 by the pair of lower discharge rollers 128 (128a and 128b), the trailing edge is moved back by the pull-in paddle 131 and the belt roller 158 as shown in FIG. It stops against the end stopper 150. Thereby, the position of the sheet S1 in the conveyance direction is aligned.

  Next, as shown in FIG. 9B, the sheet S1 whose position in the conveyance direction is aligned is centered in the width direction of the sheet S1 by the front alignment plate 340 and the back alignment plate 341, as shown in FIG. Shifting to a position shifted by 15 mm from the center of the direction (hereinafter referred to as the conveyance center position). Thereafter, each time a sheet is conveyed, this shift alignment operation is repeated on the intermediate processing tray 138 to stack a plurality of sheets, and the first sheet bundle in an overlapped state is stacked by the bundle conveying roller pair 130 (130a, 130b). Then, it is conveyed to the stacking tray 137 as shown in FIG. Thereafter, the same operation is repeated for the specified number of sorted sheets, while the second copy is shifted by a predetermined amount (15 mm) to the opposite side (back side) of the shift direction of the first copy, and the second set of sheet bundles is copied to the first copy. Similarly, the sheet is conveyed to the stacking tray 137 by the bundle conveying roller pair 130 in a state where a plurality of sheets are overlapped.

  In this way, for example, by setting the shift amount once as 15 mm from the conveyance center position, it is possible to stack the sheet bundle on the stacking tray 137 with the sort offset amount between the bundles set to 30 mm. In this embodiment, taking into consideration the transportability of the stacking tray 137, the first sheet is transported in a state where a plurality of sheets are stacked on the intermediate processing tray 138, but shift alignment is performed one by one. After each operation, the sheet may be conveyed to the stacking tray 137 each time.

  When a mode without sorting is designated, a lateral registration correction operation is performed in which the shift unit 108 returns the sheet that has been conveyed by being skewed in the upstream portion to the conveyance center position, and then the conveyance center position. Then, the sheet is conveyed to the stacking tray 137 through the bundle conveying roller pair 130. As described above, in an unbound job in which the binding process is not performed, the sheets S are conveyed to the stacking tray 137 one by one.

  Next, the staple binding mode will be described. As described above, the finisher 100 includes the one-point binding mode and the two-point binding mode. As the staple binding mode, first, the operation in the one-point binding mode will be described with reference to FIGS. 10, 11, and 12. This will be described with reference to the flowchart shown.

  As shown in FIG. 12, when a staple job is selected (S710) and printing of the image forming apparatus 600 is started (Start) (Y in S711), the sheet is then conveyed to the intermediate processing tray 138 of the finisher 100. Is started. Then, as shown in FIG. 10A, when the trailing edge of the sheet S1 passes through the nip of the lower discharge roller pair 128 and the conveyance of the sheet S1 onto the intermediate processing tray 138 is completed (Y in S712), The pull-in paddle 131 is rotated counterclockwise.

  As a result, a return process for conveying the rear end portion of the sheet S1 toward the rear end stopper 150 is performed (S713). The sheet S1 thus conveyed in the direction of the rear end stopper 150 is further drawn toward the rear end stopper 150 by the belt roller 158 that rotates counterclockwise, and is aligned while being abutted against the rear end stopper 150. Is done.

  Next, when the alignment of the sheet S1 in the conveyance direction (rear end) is completed, the sheet is shifted by 10 mm from the conveyance center position by the front alignment plate 340 and the back alignment plate 341 as shown in FIG. The sheet S1 is aligned while being shifted to (S714). This series of shift alignment operations is repeated for subsequent transport sheets until the final sheet (staple transport final sheet) Sn of the staple bundle is transported from the lower discharge roller pair 128.

  Thereafter, it is determined whether the conveyed sheet is the final conveyed sheet Sn in the bundle (S715). If the transported sheet is not the final transport sheet Sn in the bundle (N in S715), the transport operation of the next sheet to the processing tray is performed. On the other hand, if the conveyed sheet is the final conveyed sheet Sn in the bundle (Y in S715), the binding process by the stapler 132 is performed (S716). Here, in the present embodiment, the staple binding process is performed by the stapler 132 at one corner of the sheet bundle Sa, that is, at the position A or D shown in FIG. Thereafter, as shown in FIG. 11A, the swing guide 149 is lowered, the sheet bundle Sa is held between the upper conveyance roller 130b and the lower conveyance roller 130a, and the bundle conveyance roller pair 130 causes the bundle conveyance roller pair 130 to be sandwiched in FIG. As shown in FIG. 4, the sheet is conveyed to the stacking tray 137 (S717).

  Next, it is determined whether the sheet bundle thus conveyed is the final bundle (S718). If it is not the final bundle (N in S718), the second and subsequent sheet bundles are shifted by 10 mm to the opposite side (back side) from the shift direction of the immediately preceding preceding bundle, and the same alignment process is performed. A binding process is performed, and the bundle is conveyed to the stacking tray 137 by the bundle conveying roller pair 130. Such a series of operations is repeated for the designated number of bundles, and after that, when the final bundle is conveyed (Y in S718), the job ends.

  In this manner, the sheet bundle Sa is set in a state in which the sort offset amount between the staple binding bundles is set to 20 mm by alternately shifting the sheet bundle by 10 mm from the conveyance center to the opposite side to the shift direction of the immediately preceding preceding process bundle. Are stacked on the stacking tray 137. Then, by shifting the conveyance position of the sheet bundle Sa from the conveyance position of the preceding process bundle in this way, the overlap of the staple binding needles on the stacking tray is avoided, and the total height of the stacked binding sheet bundle Sa is stacked. Can be kept low.

  When the number of bundles is small, or when it is desired to stack staple bundles together, alignment processing may be performed so that the preceding processing bundle and the transport position are aligned. Further, in the present embodiment, the offset amount of the staple binding bundle is set to 20 mm with respect to the offset amount on the stacking tray in the non-binding sort mode being 30 mm. Here, each offset amount is determined based on the sorting visibility of unbound sheets, the minimum amount of shift that can avoid stapling staple overlap, and the reduction of processing time by the shift movement amount. Not a thing.

  Next, the operation in the two-point binding mode will be described with reference to the flowcharts shown in FIGS. When the two-point binding job is selected by the operation unit 601, the front alignment plate 340 is first positioned at the conveyance center standby position for aligning the sheet at the position where the center in the width direction of the sheet coincides with the conveyance center position. The front alignment plate motor is activated (S801). Thereafter, when the front alignment plate 340 comes to stand by at the transport center standby position (Y in S802), the back alignment plate motor is activated to make the back alignment plate 341 stand by at the transport center standby position (S803). When the back alignment plate 341 comes to wait at the transport center standby position (Y in S804), the stapler moving motor M303 is activated (S805).

  Next, when the sheet bundle is conveyed, it is determined whether the sheet bundle is conveyed in a state shifted to the near side of the stacking tray, that is, whether the conveyance of the sheet bundle is the near-shift position conveyance (S806). If the transport of the binding sheet bundle is the front shift position transport (Y in S806), the stapler moving motor M303 moves the stapler toward, for example, the back side position of the two-point binding, which is the C position in FIG. Thereafter, when the stapler stands by at the back side position of the two-point binding (Y in S807), the preparation for receiving the sheet is completed (S809).

  Further, when the transport of the bound sheet bundle is not the front shift position transport (Y in S806), that is, when the back shift position transport is performed, the stapler is moved by the stapler moving motor M303, for example, the two-position binding at the B position in FIG. Move it toward you. Then, when the stapler stands by at the position before the two-point binding (Y in S808), the preparation for receiving the sheet is completed (S809).

  Next, by moving the stapler according to the shift conveyance position of the binding sheet bundle in this way, after the preparation for receiving the sheet is completed, the stapler is conveyed from the lower discharge roller pair 128 in the same manner as the one-point binding job. The sheet S1 is conveyed onto the intermediate processing tray 138. Thereafter, the sheet feeding direction is aligned while abutting against the trailing edge stopper 150 by the drawing paddle 131 and the belt roller 158.

  Next, the front alignment unit 340 and the back alignment unit 341 that have been waiting at the transport center standby position are moved toward the center in the width direction, whereby the sheet S is changed to the sheet S as shown in FIG. The center of the sheet is aligned while shifting to a position that coincides with the transport center position. This shift alignment operation is repeated for the subsequent transport sheet, and is repeated until the final sheet Sn of the staple bundle is transported from the lower discharge roller pair 128.

  Next, acceptance of such a sheet is started, and as shown in FIG. 15, when the final sheet Sn is conveyed to the intermediate processing tray 138 (Y in S811), the alignment operation is also performed on this final sheet Sn. Done. Thereafter, the stapler 132 performs a binding process on the first position along the rear edge of the sheet bundle Sa (S812). At this time, when the binding sheet bundle is transported to the front shift position, the stapler 132 binds the first place at the C position shown in FIG. 4 and then moves to the B position along the guide rail groove 307 together with the slide support 303. Move to the second binding position.

  Here, in the present embodiment, after the first position is bound as described above, it is determined whether the bound sheet bundle is conveyed to the front shift position (S813). When the bound sheet bundle is transported to the front shift position (Y in S813), the front alignment plate motor is moved so that the front alignment plate 340 reaches the front reference position, that is, the front alignment plate 340 is moved 10 mm toward the front of the apparatus. Start up (S814).

  Next, when the front alignment plate 340 reaches the front reference position (Y in S815), the back alignment plate motor is activated so that the back alignment plate 341 moves the sheet bundle 10 mm toward the front side of the apparatus (S816). Further, the stapler moving motor M303 is activated to move the stapler 132 from the B position in FIG. 4 to the C position, which is the second binding position (S817).

  Then, the 10 mm movement of the sheet bundle toward the front side of the apparatus by the back alignment plate 341 moving toward the front side of the apparatus is completed (Y in S818), and then the movement of the stapler 132 to the second binding position is completed. (Y in S819), the binding process for the second place is performed (S820).

  In this way, in the present embodiment, as shown in FIG. 13A, after the first place is bound, the first place is finished as shown in FIG. 13B. The stapler 132 is moved from position B in FIG. 6 to position C, which is the second binding position. During this time, the front alignment unit 340 and the back alignment unit 341 are moved, and the sheet bundle bound at one place is shifted from the conveyance center position to a position shifted by 10 mm toward the front side. At this time, the movement direction SA of the stapler 132 to the second binding position and the shift movement direction BA of the sheet bundle are the same direction. The shift movement of the sheet bundle is completed before or simultaneously with the movement of the stapler 132 to the B position. Thereafter, the second binding process is performed by the stapler 132.

  When the bound sheet bundle is not transported to the front shift position (Y in S813), that is, when the rear shift position is discharged, the rear alignment plate 341 is moved to the rear side until the rear alignment plate 341 reaches the rear reference position. The rear alignment plate motor is started so as to move 10 mm to the side (S823). When the back alignment plate 341 reaches the 10 mm back side reference position (Y in S824), the front alignment plate motor is then activated by the front alignment plate 340 to move the sheet bundle to the back side of the apparatus by 10 mm (S825).

  Further, the stapler moving motor M303 is activated to move the stapler 132 from the position C in FIG. 4 to the position B, which is the second binding position (S826). Then, the 10 mm movement of the sheet bundle pushed by the front alignment plate 340 moving to the back side of the apparatus to the back side of the apparatus is completed (Y in S827), and then the movement of the stapler 132 to the second binding position is completed. When completed (Y in S828), the binding process for the second location is performed (S820).

  Next, when the binding process for the second place is completed, the bundle conveyance drive motor is activated (S829), and the bundle conveyance roller pair 130 is rotated, so that the sheet is placed on the stacking tray 137 as shown in FIG. Transport the bundle. When the conveyance of the sheet bundle is completed (Y in S830), the two-point binding job is completed.

  Here, by alternately shifting 10 mm on one side from the conveyance center position on the opposite side to the shift direction of the immediately preceding preceding process bundle, the sort offset amount between the bound sheet bundles is set to 20 mm as in the one-point binding process. In this state, the sheet bundle is stacked on the stacking tray 137. As a result, it is possible to reduce the total height of the bundle of bound sheets stacked while avoiding the overlap of the staples on the stacking tray, and to improve the number of stacking units. That is, for each sheet bundle, after the stapler 132 is moved to the second binding position of the sheet bundle that has been subjected to the binding process first, the binding process is performed, and then one part of the sheet bundle that has been subjected to the binding process first. By moving to the binding position of the eyes, the number of stacked parts can be improved.

  In this embodiment, when the stapler 132 moves to the second binding position, the sheet bundle is shifted in the same direction as the stapler 132. That is, in this embodiment, the movement direction when the stapler 132 moves to the second binding position and the shift movement direction of the sheet bundle are the same direction. It should be noted that the movement start timing of the sheet bundle to the two-point binding position by the front alignment unit 340 or the back alignment unit 341 is preferably the same as or just before the movement timing of the stapler 132.

  As a result, as shown in FIG. 16, the back aligning portion that applies the pressing force P generated to move the sheet bundle Sa from the restraint point of the sheet bundle Sa corresponding to the first binding portion of the sheet bundle Sa. The distance to 341 (= free long distance) can be reduced. As a result, the sheet bundle Sa when moving the sheet bundle Sa in the width direction regardless of the sheet thickness (basis weight), the gap direction (rigidity), the density (air permeability), the surface property, the use environment, and the like. The occurrence of buckling and bending can be suppressed, and a stable and highly accurate product can be produced.

  In the present embodiment, the first binding process is performed when the center in the width direction of the sheet bundle is at the transport center position, and the second binding process is performed at a position offset by 10 mm from the transport center position. Is going on. This is a case where the stapler 132 and the central fixed rear end stopper 150c shown in FIG. Because there is.

  Therefore, in the present embodiment, as the binding order at the time of two-point binding, first, the sheet bundle is aligned and stacked at the conveyance center position, and the staple binding position on the opposite direction side where the bundle shifts by 10 mm is moved later. The binding process is implemented. Thereafter, the stapler is moved to the second binding position, and at the same time, the sheet bundle is moved to a position offset from the conveyance center by 10 mm on one side (away from the fixed fixed rear end stopper 150c). The rear end stoppers 150a and 150b positioned on the side where the sheet bundle moves are configured to be movable in accordance with the sheet width size as indicated by the arrows in FIG. For this reason, the trailing end of the sheet can be abutted without interfering with the stapler 132 during the binding process.

  Further, in the sheet processing apparatus according to the present embodiment, the sheet bundle is moved to a position shifted by 10 mm on one side from the conveyance center position after the first binding process is completed. In this case, since the sheet bundle moving time is processed in parallel within the staple moving time, compared with the case where the sheet bundle is moved by 10 mm after the two-point binding is completed, the sheet processing time can be shortened. It is.

  As described above, in the present embodiment, after the stapler 132 finishes the first binding process, the stapler 132 moves to the second binding position and performs the binding process. The sheet bundle is moved in the width direction by the alignment plate on the near side. Thereby, the binding processing time can be shortened without deteriorating the quality of the deliverables.

DESCRIPTION OF SYMBOLS 100 ... Finisher, 108 ... Shift unit, 132 ... Stapler, 138 ... Intermediate processing tray, 340 ... Front aligning plate, 341 ... Back aligning plate, 600 ... Image forming apparatus, 602 ... Image forming apparatus main body, 630 ... CPU circuit part, 636 ... Finisher control unit, M303 ... Stapler moving motor, M340 ... Front alignment plate motor, M341 ... Back alignment plate motor, S ... Sheet, Sa ... Sheet bundle

Claims (6)

A sheet stacking unit for sequentially stacking conveyed sheets;
A first alignment plate that is provided in the sheet stacking section so as to be independently movable in a width direction orthogonal to the sheet transport direction, and regulates both side end positions in the width direction of the sheets sequentially transported to the sheet stacking section; A second alignment plate;
A first drive unit that moves the first alignment plate and the second alignment plate in the width direction; and
A binding unit that is provided so as to be movable in the width direction, and that performs binding processing at two or more locations on the sheet stacking unit on the sheet stacking unit, the positions of both side ends of which are regulated by the first alignment plate and the second alignment plate;
A second drive unit for moving the binding unit in the width direction;
After the binding unit finishes the first binding process, the first binding plate out of the first alignment plate and the second alignment plate is moved to the second binding position to perform the binding process. A sheet processing apparatus comprising: the first driving unit and a control unit that controls the second driving unit so as to move the sheet bundle in the width direction by one alignment plate close to the position.   The control unit is configured such that, of the first alignment plate and the second alignment plate, the other alignment plate that is close to the second binding position is positioned before the one alignment plate or simultaneously with the one alignment plate. The sheet processing apparatus according to claim 1, wherein the first driving unit is controlled to move in the width direction.   3. The control unit according to claim 1, wherein the control unit controls the first driving unit and the second driving unit to move the one alignment plate at the same timing as the movement of the binding unit. Sheet processing device.   4. The method according to claim 1, wherein the binding processing at the first location is performed at a position where a center in the width direction of the sheet bundle coincides with a center in the width direction of the sheet stacking unit. Sheet processing device.   For each sheet bundle, the control unit performs the binding process after moving the binding unit to the second binding position of the sheet bundle on which the binding process has been performed first, and then performing the binding process first. 5. The sheet processing apparatus according to claim 1, wherein the second driving unit is controlled to move to the first binding position of the sheet bundle. 6.   An image forming unit comprising: 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. apparatus.

Images