JP2010120705A - Sheet stacking device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent failure of delivering or aligning sheets by suppressing a sheet from rising from a loading face to prevent interference due to the sheet rise. <P>SOLUTION: This device includes a housing guide 803 for loading delivered sheets, a sheet positioning member for receiving the downstream end of the sheet delivered to the housing guide 803 in a sheet delivery direction, and a plurality of presser members 12a, 12b provided in a width direction orthogonal to the sheet delivery direction, and pressing the sheets received by the sheet positioning member to the housing guide 803. Among a plurality of the presser members 12a, 12b, the presser member 12b at a center in the sheet width direction presses the sheet in prior to the presser member 12a on the sheet width end. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sheet stacking apparatus that stacks and holds conveyed sheets to create a sheet bundle, and an image forming apparatus having the sheet stacking apparatus.

  2. Description of the Related Art Conventionally, there has been known a sheet processing apparatus in which a sheet on which an image is formed by a main body of an image forming apparatus is stacked in a bundle on a stacking tray and bound, and then folded into a booklet (see Patent Document 1). ). In this sheet processing apparatus, sheets on which images are formed are sequentially received by a stacking tray, aligned and bundled, and the central portion thereof is stapled. Subsequently, the central portion of the sheet bundle is projected by a protruding member and pushed into the nip of the pair of folding rollers, and the sheet bundle is folded while being conveyed by the pair of folding rollers to form a booklet.

  When the sheets having the images formed thereon are sequentially received by the stacking tray as described above, if the trailing edge of the preceding sheet already stacked on the stacking tray is lifted from the stacking surface, the succeeding sheet is subsequently conveyed to the stacking tray. The leading edge of the sheet may interfere. In order to prevent this, a technique is disclosed in which a rear end pressing member that presses the rear end of the preceding sheet already stacked on the stacking tray is provided (see Patent Document 2).

JP 2007-76793 A JP 2006-306522 A

  In recent years, the speed of image forming apparatuses has been increased, and as a result, the amount of heat in the fixing unit has increased, and the sheet that has passed through the fixing unit has been curled (deformed into a loop shape). Sent to the device.

  The rear end pressing member disclosed in Patent Document 2 is configured to press both ends in the width direction orthogonal to the sheet conveying direction. For this reason, when the central portion in the width direction of the sheet is curled in a direction away from the stacking surface of the stacking tray, the central portion in the width direction cannot be pressed even if the sheet is pressed by the trailing edge pressing member. It will be in a state of being lifted from the loading surface. As a result, the leading edge of the succeeding sheet interferes with the trailing edge of the preceding sheet, resulting in sheet stacking failure or misalignment, which may adversely affect subsequent processing.

  Accordingly, an object of the present invention is to suppress sheet lift from the stacking surface, prevent sheet interference caused by sheet lift, and prevent sheet conveyance failure and alignment failure.

  In order to solve the above-described problems, the present invention provides a sheet stacking unit that stacks conveyed sheets, a sheet positioning member that receives an end on the downstream side in the transport direction of the sheet transported to the sheet stacking unit, and a sheet A sheet pressing member that is provided in the width direction orthogonal to the conveying direction of the sheet and presses the sheet received by the sheet positioning member against the sheet stacking unit, and the width of the sheet among the plurality of sheet pressing members The sheet pressing member on the center side in the direction presses the sheet before the sheet pressing member on the end side in the width direction of the sheet.

  According to the present invention, it is possible to hold a sheet parallel to the stacking surface. Accordingly, it is possible to prevent sheet interference caused by lifting of the sheet end, and to prevent sheet conveyance failure and alignment failure. In particular, it is possible to process a sheet sent to a sheet stacking apparatus in a non-flat state such as a curled sheet without causing a conveyance failure or alignment failure.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. Therefore, unless specifically stated otherwise, the scope of the present invention is not intended to be limited thereto.

  First, the image forming apparatus will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing a schematic configuration of the image forming apparatus. Here, a copying machine is illustrated as the image forming apparatus.

(Image forming device)
As shown in FIG. 2, a copier 1000 as an image forming apparatus includes a document feeding unit 100, an image reader unit 200, a printer unit 300, a folding processing unit 400, a finisher 500, and an inserter 900. The folding processing unit 400 and the inserter 900 can be equipped as options.

  On the tray 1001 of the document feeder 100, the document D is set in an upright state as viewed from the user and in a face-up state (the surface on which the image is formed is facing upward). Yes. The binding position of the document D is assumed to be located at the left end portion of the document. Documents D set on the tray 1001 are conveyed by the document feeder 100 one by one from the top page in the left direction, that is, with the binding position at the top. Then, the document D passes through a curved path, is conveyed from the left to the right on the platen glass 102, and is then discharged onto the discharge tray 112. At this time, the scanner unit 104 is stopped at a predetermined document reading position.

  The scanner unit 104 reads an image of a document that passes from the left to the right on the scanner unit 104. Such a method of reading a document is referred to as “scanning scanning”. When the document passes over the platen glass 102, the document is irradiated by the lamp 103 of the scanner unit 104. The reflected light from the original is guided to the image sensor 109 via the mirrors 105, 106, 107 and the lens 108.

  The image reader unit 200 can also perform document reading processing by temporarily stopping the document on the platen glass 102 by the document feeding unit 100 and moving the scanner unit 104 from left to right in this state. This reading method is called “fixed reading”. When reading a document without using the document feeding unit 100, the user opens and closes the document feeding unit 100 and sets the document on the platen glass 102. Thereafter, the scanner unit 104 reads the document in a fixed manner.

  The document image data read by the image sensor 109 is subjected to predetermined image processing and sent to the exposure control unit 110. The exposure control unit 110 outputs laser light corresponding to the image signal. The laser light is irradiated onto the photosensitive drum 111 while being scanned by the polygon mirror 110a. An electrostatic latent image corresponding to the scanned laser beam is formed on the photosensitive drum 111.

  The electrostatic latent image formed on the photosensitive drum 111 is developed by the developing unit 113 and visualized as a toner image. On the other hand, the sheet P such as recording paper is conveyed to the transfer unit 116 from any of the cassettes 114 and 115, the manual feed unit 125, and the double-sided conveyance path 124. The visualized toner image is transferred to the sheet in the transfer unit 116. The transferred image is fixed with a toner image by a fixing unit 177. The photosensitive drum 111, the developing unit 113, and the like constitute an image forming unit.

  The sheet that has passed through the fixing unit 177 is once guided to the path 122 by the switching member 121. When the rear end of the sheet passes through the switching member 121, the sheet is conveyed in a switchback and guided to the discharge roller 118 by the switching member 121. The sheet is discharged from the printer unit 300 by the discharge roller 118. Thus, the sheet is discharged from the printer unit 300 with the surface on which the toner image is formed facing downward (face down). These operations are called “reverse discharge”.

  When the sheet is discharged to the outside in the face-down state, the image forming process can be performed in order from the first page. For example, the page order can be aligned when image forming processing is performed using the document feeder 100 or when image forming processing is performed on image data from a computer.

  When forming images on both sides of the sheet, the printer unit 300 guides the sheet straight from the fixing unit 177 to the discharge roller 118. Immediately after the trailing edge of the sheet passes through the switching member 121, the sheet is switched back and guided to the duplex conveyance path 124 by the switching member 121.

(Folding processing unit 400)
Next, configurations of the folding processing unit 400 and the finisher 500 will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view of the finisher 500.

  In FIG. 2, the folding processing unit 400 includes a conveyance path 131 that receives a sheet discharged from the printer unit 300 and guides it to the finisher 500 side. The conveyance path 131 is provided with a conveyance roller pair 130 and a discharge roller pair 133. A switching member 135 provided in the vicinity of the discharge roller pair 133 guides the sheet conveyed by the conveyance roller pair 130 to the folding path 136 or the finisher 500 side.

  When performing the sheet folding process, the switching member 135 switches to the folding path 136 side and guides the sheet to the folding path 136. The sheet conveyed to the folding path 136 is abutted against the stopper 137 to form a loop, and then folded by the folding rollers 140 and 141. The sheet is Z-folded by further folding the loop formed by abutting the folded portion against the upper stopper 143 by the folding rollers 141 and 142. The Z-folded sheet is guided through the conveyance paths 145 and 131 and discharged to the finisher 500 by the discharge roller pair 133. Note that the folding processing operation by the folding processing unit 400 is selectively performed.

  When the folding process is not performed, the switching member 135 is switched to the side that guides the sheet to the finisher 500. The sheet discharged from the printer unit 300 passes through the conveyance path 131 and the switching member 135 and is directly sent to the finisher 500.

(Finisher 500)
The finisher 500 aligns a plurality of sheets conveyed from the printer unit 300 via the folding processing unit 400 and processes the sheets. The sheet processing includes a process of bundling as one sheet bundle, a stapling process (binding process) for stapling the rear end side of the sheet bundle, a sort process, a non-sort process, and the like.

  As shown in FIG. 1, the finisher 500 has a conveyance path 520 for taking the sheet conveyed through the folding processing unit 400 into the apparatus. The conveyance path 520 is provided with conveyance roller pairs 502 to 508 in order from the inlet roller pair 501 toward the downstream side in the sheet conveyance direction.

  A punch unit 530 is provided between the conveyance roller pair 502 and the conveyance roller pair 503. The punch unit 530 operates as necessary to make holes (perforate processing) at the rear end of the conveyed sheet.

  A switching member 513 provided at the end of the transport path 520 switches the route between an upper discharge path 521 and a lower discharge path 522 connected downstream. The upper discharge path 521 guides the sheet to the sample tray 701 by the upper discharge roller 509. On the other hand, the lower discharge path 522 is provided with conveyance roller pairs 510, 511, and 512. These conveyance roller pairs 510, 511, and 512 convey the sheet to the processing tray 550 and discharge it.

  The sheets discharged to the processing tray 550 are stacked in a bundle while being sequentially aligned, and sorting processing and stapling processing are performed according to settings from the operation unit 1 (FIG. 2). The processed sheet bundle is selectively discharged to the stack tray 700 and the sample tray 701 by the bundle discharge roller pair 551.

  The stapling process is performed by the stapler 560. The stapler 560 moves in the sheet width direction (direction intersecting the sheet conveyance direction) and binds an arbitrary portion of the sheet bundle. The stack tray 700 and the sample tray 701 are moved up and down along the main body of the finisher 500. The upper sample tray 701 receives sheets from the upper discharge path 521 and the processing tray 550. In addition, the lower stack tray 700 receives sheets from the processing tray 550. As described above, a large number of sheets are stacked on the stack tray 700 and the sample tray 701. The stacked sheets are received and aligned by a rear end guide 710 extending in the vertical direction at the rear end.

(Saddle Stitch Binding 800)
Next, the configuration of the saddle stitch bookbinding unit 800 as the sheet stacking device will be described.

  In the following description, the process of bending the sheet bundle with the pair of folding rollers 810 and the protruding member (medium folding plate member) 830 is referred to as a bending process. Further, the process of forming a crease with the press roller pair 861 on the sheet bundle subjected to the bending process is referred to as a crease process.

  A switching member 514 provided in the middle of the lower discharge path 522 switches the sheet to the right side, guides it to the saddle discharge path 523, and guides it to the saddle stitch bookbinding section 800.

  From the entrance of the saddle stitch bookbinding section 800, a saddle entrance roller pair (discharge means) 801, a pressing member 12, a storage guide (stacking means) 803 for storing sheets, a transport roller 804, and a sheet positioning member along the sheet transport direction. (Regulating member) 805 is disposed in order.

  Here, the pressing member 12 will be described with reference to FIGS. 4, 6, and 7. As shown in FIG. 4, a plurality of pressing members 12 are provided in the width direction orthogonal to the sheet conveying direction. Here, as the pressing member 12, a pressing member 12a on the end portion side in the width direction of the sheet and a pressing member 12b on the center side are illustrated, but the number and arrangement configuration of the pressing members are limited to this. It is not a thing. Further, the center side in the width direction of the sheet on which the pressing member is disposed does not necessarily need to be the center, and may be inside (closer to the center) in the sheet width direction than the end side. Further, as will be described later, the pressing member 12a and the pressing member 12b are provided on the same axis and simultaneously start rotating. The pressing member 12a shown in FIGS. 6 (a), 6 (b), and 6 (c) and the pressing member 12b shown in FIGS. 7 (a), 7 (b), and 7 (c) represent the same timing state after the rotation of the pressing member. ing.

  The pressing member 12a on the end side in the width direction of the sheet is supported by the pressing holding member 13a so as to be rotatable about the rotation shaft 23b. The holding member 12a is urged by a spring 16a that is in contact with the holding member 14 in the direction away from the sheet passing surface (sheet stacking surface) on the upstream side in the conveyance direction, and is provided on the upper end side of the holding member 13a. It abuts against the stopper and is held at the standby position (see FIG. 6A). One side of the presser holding member 14 is in contact with the presser holding member abutting member 17 and is held in a posture.

  On the other hand, the pressing member 12b on the center side in the width direction of the sheet is supported rotatably about the rotation shaft 23c. The pressing member 12b is urged in the direction away from the sheet passing surface (sheet stacking surface) by the spring 16b supported by the pressing holding member 13b, and is provided on the upper end side of the pressing holding member 13b. It abuts against the stopper and is held at the standby position (see FIG. 7A).

  As shown in FIG. 4, the holding members 13a and 13b are fixed to the rotating shaft 23a. The pressing member drive motor 22 transmits drive to the rotary shaft 23 a via the drive transmission means 25 and 27, and rotates the pressing member 12 via the pressing and holding member 13 and the pressing and holding member 14. The pressing member position detection sensor (detecting means) 24 detects the position of the pressing member 12 and is used to control the position of the pressing member 12.

  The pressing operation of the pressing member 12 will be described. The pressing member 12 is driven by the pressing member driving motor 22 and rotates toward the sheet stacking surface 15 via the drive transmission means 25 and 27 and the pressing holding member 13. The pressing member 12 is configured such that the pressing member 12a on the center side in the width direction of the sheet presses the sheet before the pressing member 12b on the end side in the width direction of the sheet. This will be described below.

  First, the pressing member 12b on the center side rotates around the rotating shaft 23a in response to the driving of the pressing member driving motor 22 from the state shown in FIG. 7A held by the holding member 13b and the spring 16b. Then, first, the lower end (end on the downstream side in the transport direction) of the pressing member 12b comes into contact with the sheet stacking surface 15 before the upper end (end on the upstream side in the transport direction) (see FIG. 7B). The pressing member 12b further rotates about the rotation shaft 23a, and at the same time, rotates about the rotation shaft 23c, so that the entire pressing surface of the pressing member 12b contacts the sheet stacking surface 15 (see FIG. 7C).

  On the other hand, the pressing member 12a on the end side rotates from the state shown in FIG. 6A linked and held with the pressing holding member 14 from the pressing member drive motor 22 to rotate around the rotation shaft 23a. . Then, while the pressing member 12a only rotates about the rotation shaft 23a, the holding member 14 rotates about the rotation shaft 23a and at the same time rotates about the rotation shaft 23b. Accordingly, as shown in FIG. 6B, the pressing member 12a has a lower end (end on the downstream side in the conveying direction) and a sheet stacking surface at the lower end (end on the upstream side in the conveying direction) until the pressing operation is in progress. In the state close to 15, it rotates around the rotation shaft 23a. At this time, the upper end of the central pressing member 12b is in contact with the sheet stacking surface 15 as shown in FIG.

  Then, when further rotated, both the pressing member 12a and the holding member 14 rotate about the rotating shaft 23a and at the same time rotate about the rotating shaft 23b. As a result, as shown in FIG. 6C, the pressing member 12a is in a state in which the lower end and the upper end are close to the sheet stacking surface 15 just before pressing the sheet. At this time, the entire pressing surface of the pressing member 12b on the center side is in contact with the sheet stacking surface 15 as shown in FIG.

  The pressing member 12 a further rotates from the state shown in FIG. 6C after the central pressing member 12 b contacts the sheet stacking surface 15, and the entire pressing surface contacts the sheet stacking surface 15.

  As described above, since the pressing member 12a and the pressing member 12b have different link mechanisms, the contact timing of the central pressing member 12b and the end pressing member 12a to the sheet can be shifted. In other words, the sheets can be pressed in order from the center side in the width direction of the sheet toward the end side, and even if the central portion in the width direction of the sheet is curled away from the sheet stacking surface, the sheet bulges. be able to.

  A method of removing the sheet bulge will be described with reference to FIG. FIG. 8 is an explanatory view of the operation of the pressing member 12 as viewed from the sheet conveying direction. As shown in FIG. 8A, the sheet P swelled in the direction away from the sheet stacking surface 15 in the direction orthogonal to the sheet conveying direction is stacked on the sheet stacking surface 15 of the storage guide 803.

  At this time, as shown in FIG. 8 (b), the center side pressing member 12b comes into contact with the sheet P before the end side pressing member 12a, and the curl (bulge) of the sheet P is removed. The sheet P is pressed against the sheet stacking surface 15.

  Thereafter, the pressing member 12a on the end side comes into contact with the sheet P. After the center side pressing member 12b removes the central bulge of the sheet P, the both end side pressing members 12a come into contact with each other, so that the bulge on the outer side (both sides) of the sheet P shown in FIG. As a result, the entire curled sheet P can be pressed onto the sheet stacking surface 15 as shown in FIG.

  As shown in FIG. 1, the storage guide 803 is inclined such that the downstream side in the sheet conveyance direction is lower than the upstream side. Here, a storage guide 803 that is inclined substantially vertically (75 ° with respect to the horizontal direction in FIG. 1) is illustrated. A holding member 11 that holds the end portion of the sheet is provided above the storage guide 803. The holding member 11 moves in the sheet discharge direction in accordance with the movement of the rear end position of the stacked sheets, and holds the rear end portion (rear end in the discharge direction) of the stacked sheets in the conveyance direction.

  The saddle entrance roller pair 801 and the transport roller 804 are rotated by the transport motor M1. The conveyance roller 804 is supported by the conveyance roller separation motor M10 so as to be able to come into contact with and separate from the sheet, and can contact and separate at a predetermined timing. The conveyance roller position detection sensor 64 detects the position of the conveyance roller 804, and controls the position of the conveyance roller 804 moved by the conveyance roller separation motor M10 based on this detection. While the conveying roller 804 is in contact with the sheet to be discharged, the holding member 11 holds the rear end in the discharge direction of the sheet already stacked.

  A stapler (binding means) 820 is provided in the middle of the storage guide 803 so as to face the storage guide 803. The stapler 820 includes a driver 820a that projects a needle and an anvil 820b that bends the projected needle.

  The sheet positioning member 805 is movable in the conveyance direction so as to receive the leading end (lower end) of the ejected sheet and carry out stapling processing (binding processing) at the center of the sheet conveyance direction when the sheet is carried in. . The sheet positioning member 805 is moved up and down by the sheet positioning member moving motor M2 so that the central portion in the sheet conveyance direction becomes the binding position of the stapler 820, and stops at a position corresponding to the sheet size. The sheet positioning member detection sensor 63 detects the position of the sheet positioning member 805, and controls the position of the sheet positioning member 805 rotated by the sheet positioning member moving motor M2 by this detection.

  That is, the rear end position of the sheet that is abutted against and aligned with the sheet positioning member 805 is different depending on the size. As shown in FIG. 3, the holding member 11 is operable in the vertical direction (conveying direction; arrow (A) direction) in FIG. 3 so that the trailing edge of the stacked sheets of different sizes can also be held.

(Holding member 11)
The holding member 11 will be described in detail with reference to FIGS. 3 and 5.

  As shown in FIG. 5, the holding member 11 is supported so as to be rotatable by a predetermined angle with respect to the rotation support member 32, and one end thereof is spring-biased by a pressing spring 33. The holding spring 33 is supported by the rotation support member 32. The rotation support member 32 is fixed to the holding member shaft 31. The holding member shaft 31 is supported rotatably with respect to the support member 35.

  The holding member rotating motor 43 applies a driving force to the driving gear unit 42 to rotate the driving shaft 41. The drive shaft 41 rotates the drive unit 40 disposed on the support member 35. As a result, the holding member shaft 31 to which the driving unit 40 is fixed rotates. The holding member position detection sensor 44 detects the position of the holding member 11, and controls the position of the holding member 11 rotated by the holding member rotation motor 43 based on this detection.

  By rotating the holding member shaft 31, the holding member 11 can move from the sheet pressing position (solid line in FIG. 3) to the retracted position (broken line in FIG. 3) against the urging force of the pressing spring 33. The holding member 11 applies a pressing force to the sheet by the spring force of the pressing spring 33 at the sheet pressing position.

  The support member 35 is fixed to the slide bush 50, and is supported so as to be capable of thrust movement with respect to the moving shaft 49 via the slide bush 50. Slide bushes 36 and 37 are fixed to both ends in the longitudinal direction of the support member 35. The support member 35 can slide on the slide rails 38 and 39 via the slide bushes 36 and 37. A timing belt 48 is fastened to a substantially central portion in the longitudinal direction of the support member 35.

  The holding member moving motor 45 transmits the driving force to the timing belt 48 via the driving unit 46. As a result, the support member 35 fixed to the timing belt 48 moves along the slide rails 38 and 39. The support member position detection sensor 51 detects the position of the support member 35, and controls the position of the support member 35 moved by the holding member moving motor 45 by this detection.

  As the support member 35 moves, the holding member 11 can rotate and move in the transport direction. With this configuration, the sheets are separated from each other so that the trailing edge of the stacked sheets and the leading edge of the next conveyed sheet do not collide while pressing the trailing edge of the stacked sheet bundle even with small-sized sheets. It also makes it possible.

(Folding roller pair 810, protruding member 830)
As shown in FIGS. 1 and 3, folding roller pairs 810 a and 810 b are provided on the downstream side of the stapler 820. A protruding member 830 is provided at a position facing the pair of folding rollers 810a and 810b. The pair of folding rollers 810a and 810b and the protruding member 830 constitute a bending portion (folding means).

  The protruding member 830 has a position retracted from the storage guide 803 as a home position. The protruding member 830 protrudes toward the stored sheet bundle by driving the motor M3, and pushes the sheet bundle into the nip between the pair of folding rollers 810a and 810b. Thereafter, the protruding member 830 returns to the home position again. Between the pair of folding rollers 810a and 810b, a pressure sufficient for a folding process for folding the sheet bundle is applied by a spring (not shown).

  The sheet bundle folded by the folding roller pair 810 is discharged to the folding bundle tray 840 via the first folding conveyance roller pair 811a and 811b and the second folding conveyance roller pair 812a and 812b.

  Sufficient pressure is applied between the first fold conveyance roller pair 811 and the second fold conveyance roller pair 812 to convey and stop the folded sheet bundle.

  The conveyance guide 813 guides the sheet bundle between the folding roller pair 810 and the first folding conveyance roller pair 811. The conveyance guide 814 guides the sheet bundle between the first fold conveyance roller pair 811 and the second fold conveyance roller pair 812. The pair of folding rollers 810, the first pair of folding and conveying rollers 811 and the second pair of folding and conveying rollers 812 sandwich the folded sheet bundle from both sides and rotate at the same speed by the same motor M4.

  In folding the sheet bundle bound by the stapler 820, the sheet positioning member 805 lowered the sheet bundle by a predetermined distance from the position at the time of stapling, and matched the staple position of the sheet bundle with the nip position of the pair of folding rollers 810. Done later. As a result, the sheet bundle is folded around the portion subjected to the stapling process (binding process).

  The alignment plate pair 815 performs alignment in the width direction perpendicular to the conveyance direction of the sheet stored in the storage guide 803. The alignment plate pair 815 moves the sheet in the nipping direction (width direction orthogonal to the conveyance direction) by the motor M5 and performs positioning (alignment) in the width direction of the sheet.

  A crease press unit 860 serving as a bending portion processing unit is provided downstream of the second fold conveyance roller pair 812. The crease press unit 860 includes a press holder 862 that supports a press roller pair 861. The fold is strengthened by moving the press holder 862 in the crease direction while the pair of press rollers 861 nips the fold. A first conveyor belt 849 is disposed directly below the crease press unit 860. The sheet bundle is conveyed from the first conveyor belt 849 to the second conveyor belt 842 and is stacked on the discharge tray 843 from the second conveyor belt 842.

(Inserter 900)
Next, the inserter 900 provided in the upper part of the finisher 500 is demonstrated based on FIG. The inserter 900 is a device that inserts a sheet (insert sheet) different from a normal sheet into the first page, last page, or intermediate page of a sheet (recording paper) on which an image is formed by the printer unit 300. The insert sheets on the first page and the last page are cover sheets.

  The inserter 900 feeds sheets set on the insert trays 901 and 902 by the user to any of the sample tray 701, the stack tray 700, and the folding tray 840 without passing through the printer unit 300. The inserter 900 sequentially separates sheet bundles stacked on the insert trays 901 and 902 one by one and sends them to the conveyance path 520 at a desired timing.

(Control part)
Here, the configuration of the control system of the entire copying machine will be described. FIG. 12 is a functional block diagram showing the configuration of the finisher control unit 515 of the finisher 500. As shown in FIG. FIG. 13 is a control block diagram of the copying machine 1000. First, the finisher control unit 515 of the finisher 500 will be described, and then the control configuration of the entire copying machine will be described.

  As illustrated in FIG. 12, the finisher control unit 515 is configured by a microcomputer system and includes a CPU 60, a ROM 59, and a RAM 61. The ROM 59 stores a puncher processing program and a stapling processing program in advance. The CPU 60 executes each program and creates a predetermined control signal by performing input data processing while appropriately exchanging data with the RAM 61.

  Detection signals from the inlet detection sensor 62, the pressing member position detection sensor 24, the holding member position detection sensor 44, the support member position detection sensor 51, the sheet positioning member detection sensor 63, and the conveyance roller position detection sensor 64 are input to the CPU 60. These detection signals are input to the CPU 60 as input data via the input interface circuit 57.

  Various control signals are output from the CPU 60 via the output interface circuit 58. The output signal is transmitted to a control device such as a motor driver, and controls the control device to control the conveyance motor M1, the pressing member driving motor 22, the holding member rotating motor 43, the holding member moving motor 45, and the sheet positioning member moving motor M2. Then, the conveyance roller separation motor M10 is operated. Further, data communication is transmitted and received between the CPU circuit unit 150 (see FIG. 13) provided on the image forming apparatus main body (copier main body) side and the CPU 60 of the finisher 500.

  FIG. 13 is a control block diagram of the copying machine 1000. The CPU circuit unit 150 has a CPU (not shown). The CPU circuit unit 150 controls the document feed control unit 101, the image reader control unit 201, the image signal control unit 202, the printer control unit 301, the folding processing control unit 401, the finisher control unit 515, and the external I / F 203. The control by the CPU circuit unit 150 is based on the control program stored in the ROM 151 and the setting of the operation unit 1.

  The document feeding control unit 101 controls the document feeding unit 100, the image reader control unit 201 controls the image reader unit 200, the printer control unit 301 controls the printer unit 300, and the folding processing control unit 401 controls the folding processing unit 400. . The finisher control unit 515 controls the finisher 500, the saddle stitch bookbinding unit 800, and the inserter 900, respectively.

  The operation unit 1 includes a plurality of keys for setting various functions relating to image formation, a display unit for displaying a setting state, and the like. The operation unit 1 outputs a key signal corresponding to the operation of each key by the user to the CPU circuit unit 150 and displays corresponding information based on the signal from the CPU circuit unit 150 on the display unit.

  The RAM 152 is used as an area for temporarily storing control data and a work area for computations associated with control. An external I / F 203 is an interface between the copying machine 1000 and an external computer 204, develops print data from the computer 204 into a bitmap image, and outputs the image data to the image signal control unit 202. An image of the original read by the image sensor 109 is output from the image reader control unit 201 to the image signal control unit 202. The printer control unit 301 outputs the image data from the image signal control unit 202 to the exposure control unit 110.

  Further, sheet information and conditions relating to sheet type (plain paper, coated paper, special paper), sheet size, and the like are input from the operation unit (operation panel) 1 of the image forming apparatus main body by a user's operation, and the CPU circuit unit 150 receives these sheets. Can acquire and recognize conditions. In addition to the above sheet size, the sheet conditions include physical properties such as stiffness, thickness, basis weight, surface resistance, and smoothness (surface properties), sheet types such as punched paper, tab paper, and the like.

  The control unit may be provided in any of the sheet stacking device (saddle stitch bookbinding unit 800), the finisher 500, and the apparatus main body (printer unit 300).

(Sheet processing operation in the saddle stitch bookbinding section 800)
Next, a sheet processing operation in the saddle stitch bookbinding unit 800 will be described with reference to FIGS.

  As shown in FIG. 14, first, a sheet size identification process is performed (S1). Based on the identified sheet size, the sheet positioning member 805 moves to a position corresponding to the size (S2). The holding member 11 is moved in accordance with the rear end position of the stacked sheets (S3). The holding member 11 rotates to the sheet holding position (S4).

  As shown in FIG. 9A, the sheet P is transferred from the saddle entrance roller pair 801 to the conveying roller 804 (S5). At this time, in order to hold the sheet P stacked on the sheet stacking surface 15 of the storage guide 803, the transport roller 804 is positioned at a holding position (contact position).

  As shown in FIG. 9B, the sheet P passes through the entrance detection sensor 62 and is conveyed by the conveying roller 804, and the leading end is conveyed to the vicinity of the sheet positioning member 805. Then, after the trailing edge of the sheet P passes through the entrance detection sensor 62, the conveyance roller 804 is separated from the sheet P at a predetermined timing.

  As shown in FIG. 10A, after the conveying roller 804 is separated from the sheet P, the holding member 11 is rotated from the holding position (11a position) to the retracted position (11b position) (S6). In this state, alignment operation in the direction orthogonal to the sheet conveying direction is performed by the alignment plate pair 815 (S7).

  As shown in FIG. 10B, after the alignment operation is completed, the holding member 11 starts to rotate to the holding position, and the holding member 13 starts to rotate to the pressing position (S8). Then, the center side pressing member 12b comes into contact with the sheet P before the end side pressing member 12a (S9), and starts pressing the center in the width direction of the sheet P on the sheet stacking surface 15.

  As shown in FIG. 11A, the holding member 13 and the holding member 12 further rotate, and the pressing member 12a on the end side comes into contact with the sheet P following the pressing member 12b on the center side (S10). Then, after the center side pressing member 12 b presses the sheet P onto the sheet stacking surface 15 with the pressing surface, the end side pressing member 12 a presses the sheet P onto the sheet stacking surface 15 with the pressing surface. Thus, even if the sheet conveyed to the storage guide 803 is curled, the bulge of the sheet P is gradually pressed from the center toward the outside, and the pressing surface of the pressing member 12 holds the sheet P to the sheet. It is in a state where it is completely pressed against the loading surface 15. The timing at which the sheet is pressed against the sheet stacking surface by the plurality of pressing members is such that at least a part of the center side pressing member 12b presses the sheet P first in the width direction of the sheet, and then the end side pressing member 12a. However, it may be configured to hold the sheet P.

  As shown in FIG. 11B, the holding member 11 rotates to the holding position while holding the entire sheet P against the sheet stacking surface 15 by the pressing member 12, and holds the rear end portion of the sheet P1 (S11). . As described above, the operations from S4 to S11 are repeated until the last sheet is stacked (S12).

  Even if the curled sheet is conveyed to the substantially vertical storage guide 803 by the above operation, the bulge of the sheet may be pressed in order from the center side to the end side, and the entire curled sheet may be pressed against the sheet stacking surface. it can. Thereby, it is possible to prevent the sheet bundle from partially bulging, and to suppress the conveyance failure and alignment failure of the next conveyed sheet. Further, since the sheet is reliably pressed, the sheet can be reliably held by the holding member 11.

  The sheet bundle in which the final sheets are stacked and aligned is stapled by the stapler 820 (S13). Subsequently, it is detected whether the sheet bundle is in the folding position (S14). If the sheet bundle is not in the folding position, the sheet positioning member 805 is moved to the folding position and the sheet bundle is moved to the folding position (S15).

  If the sheet bundle is in the folding position, folding processing is performed by the protruding member 830 and the folding roller pair 810 (S16). Then, the crease processing is performed by the crease press unit 860 (S17). The sheet bundle subjected to the crease processing is discharged to the discharge tray 843 (S18).

  When the final sheet bundle has been discharged, the job is ended (S19, S20). If the final sheet bundle has not been discharged, the process returns to S4 (S19).

  As described above, the pressing member 12b on the center side in the width direction of the sheet presses the sheet earlier than the pressing member 12a on the end side, whereby the sheet swollen due to curl or the like is moved from the center side toward the end side. The sheets can be pressed in order and completely pressed onto the sheet stacking surface 15. As a result, it is possible to prevent the sheet from partially swelling, and to suppress the conveyance failure and alignment failure of the next sheet to be conveyed.

  In the above-described embodiment, the configuration in which one pressing member on the center side and two pressing members on the end side are arranged as a plurality of sheet pressing members provided in the width direction of the sheet. The arrangement is not limited to this. If necessary, arrange two holding members on the center side and two holding members on the end side, or arrange one on the center side, two on both outsides, and two holding members on both outsides. What is necessary is just to set suitably. Also, other configurations are possible as long as the sheet can be pressed in order from the center in the width direction to the end side without having to be symmetrical about the center in the width direction of the sheet.

  In the above-described embodiment, as a processing unit that performs processing on a sheet, a binding unit (stapler 820) that performs sheet bundle binding processing, and a folding unit (extruding member 830, folding roller pair 810) that performs folding processing of a sheet bundle. Although illustrated, it is not limited to this. Any other processing means may be used as long as it is a processing means for processing the sheet.

  In the above-described embodiment, the copying machine is exemplified as the image forming apparatus, but the present invention is not limited to this. For example, the image forming apparatus may be another image forming apparatus such as a printer or a facsimile apparatus, or another image forming apparatus such as a multi-function machine that combines these functions. The same effect can be obtained by applying the present invention to a sheet stacking apparatus used in such an image forming apparatus.

  In the above-described embodiment, the sheet processing apparatus (finisher 500 including the saddle stitch bookbinding unit 800) that can be attached to and detached from the main body of the image forming apparatus is illustrated as the sheet stacking apparatus according to the present invention. However, the present invention is not limited thereto. Is not to be done. For example, the image forming apparatus may be a sheet stacking apparatus that is integrally provided, and the same effect can be obtained by applying the present invention to the sheet stacking apparatus.

Sectional drawing which shows the structure of the finisher which has a saddle stitch bookbinding part Sectional view showing configuration of image forming apparatus Schematic cross-sectional view showing the configuration of the saddle stitch bookbinding Perspective view of pressing member in saddle stitch bookbinding The perspective view of the holding member in a saddle stitch bookbinding part Operation explanatory diagram of the pressing member on the end side Operation explanatory diagram of the pressing member on the center side Operation explanatory diagram of the holding member Explanatory drawing of operation of pressing member and holding member in saddle stitch bookbinding Explanatory drawing of operation of pressing member and holding member in saddle stitch bookbinding Explanatory drawing of operation of pressing member and holding member in saddle stitch bookbinding Control block diagram of saddle stitch bookbinding Control block diagram of the entire copier The flowchart figure which shows the flow of a processing operation of the sheet | seat of a saddle stitch bookbinding part

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Holding member 12,12a, 12b ... Pressing member 15 ... Sheet stacking surface 111 ... Photosensitive drum 113 ... Developer 800 ... Saddle stitch bookbinding part 803 ... Storage guide 805 ... Sheet positioning member 1000 ... Copier

Claims (4)

A sheet stacking means for stacking the conveyed sheets;
A sheet positioning member for receiving an end portion on the downstream side in the conveyance direction of the sheet conveyed to the sheet stacking means;
A plurality of sheets in the width direction orthogonal to the sheet conveying direction, and a sheet pressing member that presses the sheet received by the sheet positioning member against the sheet stacking unit,
A sheet stacking apparatus, wherein a sheet pressing member on a center side in the width direction of the sheet presses a sheet earlier than a sheet pressing member on an end portion side in the width direction of the sheet among the plurality of sheet pressing members.   2. The sheet stacking apparatus according to claim 1, wherein the sheet stacking unit is inclined such that the downstream side in the sheet transport direction is lower than the upstream side. A holding member that is movable according to the position of the upstream end of the sheet stacked on the sheet stacking means and holds the upstream end of the sheet in the transport direction;
3. The sheet stacking apparatus according to claim 1, wherein the holding member holds an end portion of the sheet after the sheet pressing member presses the sheet against the sheet stacking unit.   An image forming apparatus comprising: an image forming unit that forms an image on a sheet; and the sheet stacking apparatus according to claim 1 that processes the sheet on which the image is formed.

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