JP2016093936A - Sheet-processing equipment, and image formation equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-quality booklet by constituting the back of the booklet into a generally rectangular shape and by preventing the inward fold of the innermost sheet from protruding to the inner side of a sheet bundle S.SOLUTION: In order that the innermost sheet to come to the innermost side when a sheet bundle is folded along a folding part 830 such that the mountain side of the fold given by a fold applying part 404 may direct the outermost sheet to become on the outermost side when the sheet bundle is folded by the folding part, and either the innermost sheet or said outermost sheet is turned upside down or back to front and transferred to the loading part 810 so that the mounting side of the fold applied by the fold applying part 404 may face the innermost sheet.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet processing apparatus and an image forming apparatus that perform saddle stitching by binding and folding a sheet bundle composed of a plurality of sheets.

2. Description of the Related Art Conventionally, a bookbinding apparatus that binds the center of a sheet bundle composed of a plurality of sheets on which images are formed and folds the binding portion of the sheet bundle to perform saddle stitching is known. In general, when booklet binding is performed by a bookbinding apparatus, for example, a booklet using a relatively thick sheet having a basis weight of 105 g / m ² is used, for example, a booklet using a relatively thin sheet having a basis weight of 64 to 80 g / m ^2. Compared to this, the so-called “back cracking” that breaks the booklet tends to occur. In addition, when a sheet on which a toner image using a thermoplastic resin toner is folded by the bookbinding apparatus, the toner image may be broken and the appearance may be impaired.

  Therefore, as shown in FIG. 17, a sheet is disposed between the convex teeth 901 having convex portions and the concave grooves 902 that can be engaged with the convex teeth 901, and the sheets are sandwiched by the convex teeth 901 and the concave grooves 902. Thus, an apparatus for applying a crease to a sheet has been proposed (see Patent Document 1). In this proposed apparatus, when the saddle stitch bookbinding is performed, a crease is given to the folding position of the sheet in advance before binding the sheet bundle, thereby reducing the back crack and the toner image crack.

  Conventionally, a saddle stitch folding machine has been proposed that continuously performs a binding operation for binding a sheet bundle and a crease applying operation for applying a crease to the sheet bundle in a lump (see Patent Document 2). In the proposed saddle stitch folding machine, a pair of folding rollers (for example, FIG. 19 and FIG. 19) is formed by a projecting plate (for example, a projecting plate 903 shown in FIGS. 19 and 20) at the center of the sheet bundle subjected to the binding operation and the crease imparting operation. 20 toward the nip of the pair of folding rollers 904) shown in FIG. Thereby, the center of the sheet bundle is compressed by the nip of the pair of folding rollers, and the sheet bundle is folded.

JP-T-2004-522610 JP 2000-301851 A

  As shown in FIG. 18A, when a convex fold X is applied to the sheet bundle S by the device described in Patent Document 1 or the saddle stitch folding machine described in Patent Document 2, a line Y is formed at both ends of the fold X. , Y are formed. Then, as shown in FIG. 18B, when the sheet bundle S is folded so that the top portion of the fold line X faces the outside of the sheet bundle S, the folding position is stabilized at the top portion of the fold line X, but the line Y , Y is conspicuous in appearance. Further, as shown in FIG. 18C, when the sheet bundle S is folded so that the top of the fold line X faces the inside of the sheet bundle S, the shape of the back of the booklet (sheet bundle S) becomes substantially rectangular. Therefore, the streaks Y and Y are not conspicuous and the appearance of the sheet bundle S is good. However, the fold line X is compressed during the folding process and protrudes to the inside of the sheet bundle S. In particular, when the sheet bundle S is folded, the innermost sheet (hereinafter referred to as the innermost sheet) is the sheet bundle S. If it protrudes inside, the quality of the booklet will be reduced. Further, when folding the sheet bundle S so that the top of the fold line X faces the inside of the sheet bundle S, the folding position is the center of the sheet bundle S as shown in FIGS. 18 (d) and 18 (e). Instead, it may be shifted to the streaks Y and Y, thereby reducing the quality of the booklet.

  Such a shift in the folding position of the sheet bundle S will be described using a protruding plate 903 and a folding roller pair 904 included in the saddle stitch folding machine described in Patent Document 2. First, as shown in FIG. 19, both the innermost sheet of the sheet bundle S and the outermost sheet (hereinafter referred to as the outermost sheet) when the sheet bundle S is folded project toward the protruding plate 903. A case where the fold line X is given will be described. When the protruding plate 903 tries to push out the center of the sheet bundle S, as shown in FIGS. 19B and 19C, the protruding plate 903 slips due to the fold line X1 of the innermost sheet and the fold line X2 of the outermost sheet. The tip of the protruding plate 903 is located at the end of the fold line X1. In this state, when the protruding plate 903 enters the sheet bundle S and pushes the sheet bundle S to the pair of folding rollers 904, as shown in FIG. 18D or FIG. It will be a booklet shape folded in. Similarly, as shown in FIG. 20, even when the fold line X2 is formed only on the outermost sheet, the projecting plate 903 slides by the fold line X2 when entering the sheet bundle S, and the sheet bundle S moves along the lines Y and Y. The booklet will be folded.

  Accordingly, the present invention provides a sheet processing apparatus and an image forming apparatus that solve the above-described problems by forming the back of the booklet into a substantially rectangular shape and preventing the fold of the innermost sheet from protruding inside the sheet bundle S. The purpose is to provide.

  The present invention provides a sheet processing apparatus, a crease imparting unit that imparts a crease to the sheet, a stacking unit that bundles and stacks a plurality of sheets that have been creased by the crease imparting unit, and forms the sheet bundle. A conveyance unit capable of conveying a sheet with a crease provided by the applying unit to the stacking unit by reversing the front and back and front and back, a folding unit for folding the sheet bundle, and an innermost side when folding the sheet bundle by the folding unit The fold crest provided by the crease applying section faces the outermost sheet that is the outermost when the sheet bundle is folded by the fold, and the outermost sheet is Either the innermost sheet or the outermost sheet is turned upside down and front and back so that the ridge of the crease provided by the applying unit faces the innermost sheet Allowed and a control unit that controls the transport unit so as to transport to the stacking section, it is characterized.

  According to the present invention, the outermost sheet is folded into a substantially rectangular shape, and the innermost sheet does not protrude inward, so that a high-quality booklet can be provided.

1 is an overall schematic diagram showing a copying machine according to a first embodiment of the present invention. 1 is an overall schematic diagram illustrating a sheet processing apparatus. The perspective view which shows a crease | fold giving part. The side view which shows a crease | fold giving part. (A) is a side view showing a state in which the sheet forms a loop, (b) is a side view showing a state in which a crease is given to the sheet at the crease applying position, c) A side view showing a state in which a sheet with creases is conveyed. 4A and 4B are diagrams illustrating a sheet reversal operation, in which FIG. 4A is a side view illustrating a state in which the leading edge of the sheet is detected, FIG. The side view which shows the state by which is conveyed downstream. The whole side view which shows a saddle stitch binding unit. FIG. 2 is a control block diagram of a copying machine. 5 is a flowchart showing a saddle stitch folding bookbinding operation according to the first embodiment of the present invention. FIGS. 4A and 4B are diagrams illustrating a state in which an extruding member is pushed out into a bundle of two sheets, where FIG. 5A is a diagram before the extruding member is extruded, and FIG. (C) is a diagram showing a state where a sheet bundle is pushed out to the nip portion by the push member, and (d) is a diagram showing a state where the push member is pulled out from the nip portion. 3A and 3B are diagrams illustrating a state in which an extrusion member is pushed out to a bundle of three or more sheets, where FIG. 3A is a diagram before the extrusion member is extruded, and FIG. 2B is a diagram illustrating a state in which the extrusion member is engaged with the innermost sheet. . (C) is a diagram showing a state where a sheet bundle is pushed out to the nip portion by the push member, and (d) is a diagram showing a state where the push member is pulled out from the nip portion. The booklet produced by 1st Embodiment is shown, (a) is a figure which shows two booklets, (b) is a figure which shows three or more booklets. The whole side view which shows the sheet processing apparatus which concerns on the 2nd Embodiment of this invention. The side view which shows a 1st crease provision part and a 2nd crease provision part. FIGS. 2A and 2B show a crease applying operation by the first and second crease applying units, FIG. 3A is a side view showing a state in which a crease is applied by the second crease applying unit, and FIG. 2B is a crease applied by the first crease applying unit. FIG. The flowchart which shows the saddle stitch folding bookbinding operation | movement which concerns on the 2nd Embodiment of this invention. The schematic diagram which shows the apparatus which provides the conventional crease | fold. The booklet produced with the conventional saddle-stitching folding machine is shown, (a) is a perspective view which shows the booklet in the state where the crease was given, (b) is the booklet which has been subjected to the folding process with the crease facing outward. The perspective view which shows, (c) is a perspective view which shows the booklet which the folding process was performed in the state in which a fold is inward. (D) And (e) is a perspective view which shows the booklet which the folding position shifted | deviated. A state in which a veneer is pushed out to a sheet bundle in which a fold is given to the innermost sheet and the outermost sheet by a conventional saddle stitch folding machine is shown, (a) is a view before the veneer is pushed out, and (b) and (c) are folds. The figure which shows the state which the protrusion plate shifted | deviated. A state in which a veneer is pushed out to a sheet bundle in which a fold is given only to the outermost sheet by a conventional saddle stitch folding machine is shown, (a) is a view before the veneer is pushed out, (b) and (c) are verges due to the crease. FIG.

(First embodiment)
First, a first embodiment of the present invention will be described. A copying machine 1 (image forming apparatus) as an image forming apparatus includes an image forming apparatus main body 100, a document reading apparatus 200, and a sheet processing apparatus 300, as shown in FIG. The image forming apparatus main body 100 includes a sheet feeding unit 10 that feeds sheets, an image forming unit 20 that forms an image on a sheet fed from the sheet feeding unit 10, and a sheet formed by the image forming unit 20. And a fixing unit 30 for fixing the upper image. The image forming apparatus main body 100 includes a discharge unit 40 that discharges the sheet to the sheet processing apparatus 300, a double-sided conveyance path 50 that conveys the sheet that has passed through the fixing unit 30 to the image forming unit 20, and a main body control unit 60. And an operation unit 70.

  The document reading apparatus 200 includes a document feeding unit 210 and an image reader unit 220. The document feeding unit 210 places an automatic feeding tray 211 on which the document D is automatically fed. And a platen glass 212 and a discharge tray 213. The image reader unit 220 includes a scanner unit 221 that reads an image of the document D, and an image sensor 225 that reads light from the scanner unit 221 via mirrors 222 and 223 and a lens 224.

  Here, an image forming operation by the image forming apparatus main body 100 and the document reading apparatus 200 will be described. On the automatic feeding tray 211, the document D is placed in a face-up state (the surface on which the image is formed is facing upward), and the document D is fed one by one toward the platen glass 212. . The scanner unit 221 irradiates the document D passing over the platen glass 212 with light, and the image sensor 225 reads the light to read the image of the document D. The document D from which the image has been read is discharged from the discharge tray 213 to the outside of the apparatus. It is also possible to read the image of the document D while moving the scanner unit 221 by placing the document D on the platen glass 212 without placing the document D on the automatic feeding tray 211.

  Image data of the document D read by the image sensor 225 is subjected to predetermined image processing and transmitted to the exposure control unit 21 of the image forming unit 20. The exposure control unit 21 irradiates the photosensitive drum 22 whose surface is uniformly charged in advance while scanning the laser beam corresponding to the image data with the polygon mirror 21a. An electrostatic latent image corresponding to the irradiated laser beam is formed on the photosensitive drum 22, and the electrostatic latent image is developed by the developing device 23 and visualized as a toner image.

  On the other hand, in the sheet feeding unit 10, the sheet P is fed from the cassettes 11 and 12 or the manual feed unit 13. The sheet P is conveyed to the transfer unit 24 of the image forming unit 20, and the transfer unit 24 transfers the toner image on the photosensitive drum 22 to the sheet P. The sheet P is applied with heat and pressure in the fixing unit 30 to fix the toner image. The sheet P on which the toner image is fixed is guided to the double-sided conveyance path 50 by the moving member 41 in the discharge unit 40. The moving member 41 switches the conveyance path of the sheet P by rotating. When the rear end of the sheet P passes through the moving member 41, the sheet P is conveyed in a switchback and is discharged from the image forming apparatus main body 100 to the sheet processing apparatus 300 by the discharge roller 42.

  As a result, the sheet P is discharged from the image forming apparatus main body 100 in a face-down state (the surface on which the toner image is formed faces downward). When the sheet P 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 made uniform when image forming processing is performed using the document feeder 210 or when image forming processing is performed on image data transmitted from a computer or a facsimile. Note that the copying machine 1 does not necessarily require the document reading device 200, and may be reduced in size and cost without providing the document reading device 200.

  When images are formed on both sides of the sheet P, the image is transferred to the first surface of the sheet by the transfer unit 24, and the sheet P that has passed through the fixing unit 30 is guided to the discharge roller 42 by the moving member 41. The When the rear end of the sheet P passes through the moving member 41, the sheet P is switched back and guided to the double-sided conveyance path 50 by the moving member 41. Then, the image of the sheet P is transferred to the second surface of the sheet by the transfer unit 24 and is discharged from the image forming apparatus main body 100 to the sheet processing apparatus 300 in a face-down state.

  Next, the sheet processing apparatus 300 will be described. As shown in FIG. 2, the sheet processing apparatus 300 includes a crease applying apparatus 400 that applies a crease to the sheet, and a finisher 500 that performs a staple (binding) process on the sheet. The crease imparting device 400 includes a conveyance path 401, an entrance roller pair 402, a registration roller pair 403, a crease imparting unit 404, and conveyance roller pairs 405 and 406. The entrance roller pair 402 is driven by the entrance roller drive motor M1 (see FIG. 8), and the registration roller pair 403 and the transport roller pairs 405 and 406 are driven by the transport motor M2 (see FIG. 8). The entrance roller drive motor M1 and the transport motor M2 are controlled by the crease application controller 400a. Further, the crease imparting device 400 includes a sheet detection sensor S1, a front end detection sensor S2 (front end position detection unit), and a rear end detection sensor S3 (rear end position detection unit). The sheet detection sensor S <b> 1 is disposed between the entrance roller pair 402 and the registration roller pair 403. The tip detection sensor S <b> 2 is disposed between the registration roller pair 403 and the crease imparting unit 404. The rear end detection sensor S3 is disposed upstream of the entrance roller pair 402 in the sheet conveyance direction.

  As shown in FIGS. 3 and 4, the crease imparting portion 404 is formed in a substantially U shape, and has a support frame 409 that rotatably supports the cam shaft 408 via a bearing 407. Are fixed with a plurality of eccentric cams 418. Further, slide shafts 410 and 410 are erected from the support frame 409, and a slide support member 411 and a cam receiving base 421 are slidably supported on the slide shafts 410 and 410, respectively. A convex portion 412 that can project into the conveyance path 401 is formed on the lower surface of the slide support member 411, and a concave portion 413 that can be engaged with the convex portion 412 is formed at a position facing the convex portion 412 of the support frame 409. ing. A plurality of springs 414 are contracted between the slide support member 411 and the cam cradle 421, and the springs 414 have sufficient elastic force to give a crease to the sheet P by the convex portions 412 and the concave portions 413. Holding.

  Lifting plates 415 and 415 that support a lifting shaft 417 are fixed to the slide support member 411, and a cam shaft 408 is inserted into a long hole 415 a formed in the lifting plate 415. The cam shaft 408 is driven by the crease applying motor M3, and the eccentric cam 418 presses the cam receiving base 421 on the lower side and presses the lifting shaft 417 on the upper side.

  Next, the operation of the crease applying device 400 will be described. As shown in FIG. 5A, the crease imparting control unit 400 a drives the entrance roller drive motor M 1 to convey the sheet P conveyed from the image forming apparatus main body 100 to the registration roller pair 403. The registration roller pair 403 is stopped when the leading edge of the sheet P reaches, and the leading edge of the sheet P comes into contact with the nip of the stopped registration roller pair 403. Thereby, a loop is formed in the sheet P, and the skew of the sheet P is corrected. The crease application control unit 400a drives the conveyance motor M2 a predetermined time after the sheet detection sensor S1 detects the sheet P to drive the registration roller pair 403 and the conveyance roller pairs 405 and 406. This predetermined time is set to a time sufficient for forming a loop on the sheet P in the registration roller pair 403.

  When the sheet P is conveyed, the eccentric cam 418 of the crease imparting section 404 is stopped at a position where it abuts on the lifting shaft 417 so that the convex section 412 is positioned at the upper position. At this time, the convex portion 412 does not protrude into the conveyance path 401 and does not hinder the conveyance of the sheet P. As shown in FIG. 5B, the crease imparting control unit 400a places the sheet P in a position where the convex portion 412 and the concave portion 413 are located at a position that is half the length in the conveyance direction of the sheet P (hereinafter referred to as a crease). To the application position), and the sheet P is stopped at the crease application position. Based on the detection of the leading edge of the sheet P by the leading edge detection sensor S2, the time until the conveying roller pairs 405 and 406 are stopped is calculated from the sheet conveying speed and the like. Based on the calculated time, the sheet P can be stopped at the crease applying position by controlling the conveying roller pairs 405 and 406.

  The crease application controller 400a drives the crease application motor M3 with the sheet P stopped at the crease application position. As a result, the cam shaft 408 rotates, and the plurality of eccentric cams 418,... Push the cam receiving base 421 downward and move it. When the cam cradle 421 moves downward, the slide support member 411 also moves downward while being guided by the slide shafts 410, 410 via the plurality of springs 414,. Thereby, the convex part 412 formed in the lower surface of the slide support member 411 engages with the concave part 413, and the sheet P is sandwiched between the convex part 412 and the concave part 413. The sheet P is sandwiched between the convex portion 412 and the concave portion 413, whereby a fold line X (see FIG. 5C) is given to the sheet P. Note that the convex portion 412 protrudes into the conveyance path 401 when a crease is given to the sheet P.

  The eccentric cam 418 continues to rotate even after the fold line X is given to the sheet P, and moves the lifting shaft 417 upward. As the lifting shaft 417 moves upward, the slide support member 411 and the convex portion 412 move upward via the lifting plates 415 and 415. Thereby, the engagement state of the convex part 412 and the concave part 413 is released, and the sheet P can be conveyed. Then, the crease application controller 400a stops the crease application motor M3 and drives the conveyance motor M2 to convey the sheet P to the finisher 500 as shown in FIG.

  When the sheet P passes through a reverse conveyance path 503 of the finisher 500 described later, the front and back of the sheet and the front and back are reversed in the course of conveyance. Therefore, for the sheet P passing through the reverse conveyance path 503, the crease application control unit 400a does not fold the crease based on the position of the trailing edge of the sheet P detected by the trailing edge detection sensor S3, not the leading edge detection sensor S2. Determine the grant position. As a result, even if a sheet whose front and back and front and back are reversed and a sheet that is not reversed are bundled, a high-quality booklet can be created without shifting the position of the applied fold.

  Next, the finisher 500 will be described. As shown in FIG. 2, the finisher 500 includes a punch unit 510, a sheet processing unit 520, and a saddle stitch binding unit 800. The punch unit 510 is disposed on a finisher conveyance path 501 through which the sheet P conveyed from the crease imparting device 400 passes, and the finisher conveyance path 501 includes an upper discharge conveyance path 502, a reverse conveyance path 503, and the like. Branch to A reversal rotation member 504 that switches the conveyance path by rotating is provided at a branch portion between the upper discharge conveyance path 502 and the reverse conveyance path 503. The upper discharge conveyance path 502 branches to the lower discharge conveyance path 505 in the middle, and a discharge rotation member 506 that switches the conveyance path by rotating is provided at this branch portion. The lower discharge conveyance path 505 joins the reverse conveyance path 503 on the way, and further branches into a processing conveyance path 507 and a saddle stitch conveyance path 508. A saddle stitch rotation member 518 is provided at a branch portion between the processing conveyance path 507 and the saddle stitch conveyance path 508 to switch the conveyance path by rotating. The finisher conveyance path 501, the upper discharge conveyance path 502, the lower discharge conveyance path 505, and the saddle stitch conveyance path 508 constitute a sheet processing conveyance path 509.

  As shown in FIG. 6, a pair of conveyance rollers 511 to 513 and a reverse detection sensor S <b> 4 that detects the leading edge of the sheet P are provided on the upper discharge conveyance path 502. In the lower discharge conveyance path 505, conveyance roller pairs 514 and 515 are provided. In the reverse conveyance path 503, conveyance roller pairs 516 and 517 are provided. The finisher transport path 501, the upper discharge transport path 502, the reverse transport path 503, the lower discharge transport path 505, the processing transport path 507, and the saddle stitch transport path 508 have other transport roller pairs as shown in FIG. Although provided, the description is omitted. The conveyance roller pairs 511 to 517 are driven by a conveyance drive motor M4 (see FIG. 8), and the conveyance drive motor M4 is controlled by a finisher control unit 500a (control unit, see FIGS. 1 and 8).

  Next, a case where the sheet P is transported through the sheet processing transport path 509 without passing through the reverse transport path 503 will be described. The sheet P on which the crease X is given in the crease imparting device 400 is subjected to punching processing as necessary by the punch unit 510 and is conveyed to the upper discharge conveyance path 502. Further, the sheet P is discharged from the upper discharge conveyance path 502 to the sample tray 701 as it is, or the conveyance path is switched by the discharge rotation member 506 and conveyed to the lower discharge conveyance path 505. The sheet P conveyed to the lower discharge conveyance path 505 is conveyed to the saddle stitch bookbinding unit 800 via the saddle stitch conveyance path 508 or the conveyance path is switched by the saddle stitch rotation member 518, and the processing conveyance path 507. It is conveyed to.

  The sheets P conveyed to the processing conveyance path 507 are discharged to the processing tray 521 of the sheet processing unit 520, and are stacked in a bundle while being sequentially aligned. The sheets P stacked in a bundle on the processing tray 521 are subjected to, for example, a binding process using staples 522 or a sorting process according to the setting of the operation unit 70. A sheet P (sheet bundle) processed on the processing tray 521 is selectively discharged to the stack tray 700 and the sample tray 701.

  Next, the reversing operation of the sheet P in the finisher 500 will be described with reference to FIG. When the sheet P is conveyed from the finisher conveyance path 501 to the upper discharge conveyance path 502 and the leading edge of the sheet P is detected by the reverse detection sensor S4, the finisher control unit 500a stops the conveyance of the sheet P. Then, the finisher controller 500a drives a solenoid (not shown) to rotate the reverse rotation member 504 and reverses the conveyance roller pairs 512 and 513 to guide the sheet P to the reverse conveyance path 503 (FIG. 6 (a) (b)). Note that the reverse rotation member 504 and the pair of conveyance rollers 512 and 513 constitute a reverse conveyance unit 530. In the finisher 500, a conveyance system that conveys the sheet P to the saddle stitch binding unit 800 is a conveyance unit 540 (see FIG. 2). The sheet P guided to the reverse conveyance path 503 is joined to the lower discharge conveyance path 505 by the conveyance roller pairs 516, 517, and 515, and then conveyed to the saddle stitch conveyance path 508 (see FIG. 6C). As a result, the sheet P can be conveyed to the saddle stitch bookbinding unit 800 with the front and back sides and the front and back sides of the sheet P reversed.

  Next, the saddle stitch binding unit 800 will be described with reference to FIG. The saddle stitch binding unit 800 includes a stacking unit 810 that stacks a plurality of sheets P, a stapler 820 (binding unit), a folding unit 830 that folds a sheet bundle, a press unit 860, and a folded bundle discharge tray 850. doing. The stacking unit 810 includes a sheet guide 811 that guides the sheet, a switching member 812 that switches the carry-in port of the sheet P according to the sheet size, and a stacking stopper that is mounted when the sheet P guided by the sheet guide 811 hits. 813. Further, the stacking unit 810 includes sliding rollers 814 to 816 that transport the sheet P to the stacking stopper 813 and a pair of alignment members 817 that align the sheets P stacked on the stacking stopper 813. The sliding rollers 814 to 816 are made of, for example, metal rollers and have high sliding properties with respect to the sheet, and the sliding rollers 815 and 816 are configured to be swingable around fulcrum shafts 815a and 816a, respectively. Yes.

  The stacking stopper 813 is configured to be movable up and down by a moving motor (not shown), and moves, for example, to an upper position indicated by a solid line in FIG. 7 and a lower position indicated by a broken line according to the sheet size. The stacking stopper 813 is positioned so that the central position (folding position) in the conveyance direction of the sheet P coincides with the position where the staple is bound by the driver 820a and the anvil 820b of the stapler 820. The sliding rollers 814 to 816 are appropriately swung so that the plurality of sheets P are supported by the stacking stopper 813 without buckling, and a sheet bundle is formed by the plurality of sheets P.

  The folding unit 830 includes a plurality of (three pairs in the present embodiment) folding roller pairs 831, 832 and 833, and an extrusion member 834 that pushes the sheet bundle toward the nip N of the folding roller pair 831 (a pair of rollers). ,have. The pushing member 834 is driven by the pushing motor M5 (see FIG. 8). Sufficient pressure is applied between the folding rollers 831, 832 and 833 by a spring (not shown) to fold the sheet bundle. The folding roller pairs 831, 832, and 833 are rotated at a constant speed by a motor (not shown), and the sheet bundle is sequentially folded by the folding roller pairs 831, 832, 833 and conveyed to the press unit 860. The

  When the sheet bundle is folded without performing the binding process by the stapler 820, the stacking stopper 813 is positioned in advance so that the central portion in the sheet bundle conveyance direction faces the nip portion N of the folding roller pair 831. On the other hand, when the binding process is performed on the sheet bundle by the stapler 820, the stacking stopper 813 is first positioned so that the central portion in the sheet bundle conveyance direction is positioned at the binding position of the stapler 820. After the sheet bundle is bound, the stacking stopper 813 is moved and positioned so that the central portion in the sheet bundle conveyance direction faces the nip portion N of the pair of folding rollers 831.

  The press unit 860 includes a press roller pair 861 that can move a fold portion of the folded sheet bundle in a width direction perpendicular to the sheet conveyance direction while maintaining a nip. The sheet bundle that has been subjected to the folding process by the folding unit 830 is compressed by the press roller pair 861 and discharged to the folded bundle discharge tray 850.

  FIG. 8 is a control block diagram of the copying machine 1. The main body control unit 60 includes a ROM 61 that stores control programs and the like, and a RAM 62 that holds temporary data and the like. The main body control unit 60 controls the document feeding control unit 63, the image reader control unit 64, the image signal control unit 65, and the printer control unit 66 in accordance with the control program and the setting of the operation unit 70. The main body control unit 60 is configured to control the finisher control unit 500 a and the crease application control unit 400 a, and a signal from another computer 68 is input through the external interface 67.

  A sheet detection sensor S1, a leading edge detection sensor S2, and a trailing edge detection sensor S3 are connected to the input side of the crease application control unit 400a, and an inlet roller drive motor M1 and a conveyance motor are connected to the output side. M2 and a crease applying motor M3 are connected. The crease application control unit 400a calculates the crease application position based on the length information in the sheet conveyance direction transmitted from the main body control unit 60 and the detection by the leading edge detection sensor S2 or the trailing edge detection sensor S3. A reversal detection sensor S4 and the like are connected to the input side of the finisher control unit 500a, and a conveyance drive motor M4 and an extrusion motor M5 are connected to the output side.

  Next, the saddle stitch folding and bookbinding operation by the copying machine 1 will be described with reference to the flowchart shown in FIG. In the booklet produced by the copying machine 1, the innermost sheet Sa when folded by the folding unit 830 is the innermost sheet Sa, and the outermost sheet is the outermost sheet Sb. A sheet sandwiched between the innermost sheet Sa and the outermost sheet Sb is defined as an intermediate sheet Sc.

  When the saddle stitch folding bookbinding operation starts, the main body control unit 60 causes the image forming apparatus main body 100 to form an image on the sheet P. At this time, the main body control unit 60 determines whether or not the sheet on which the image is to be formed is the innermost sheet Sa. If the sheet is not the innermost sheet Sa, the main body control unit 60 forms the image on the sheet and then folds the sheet. It is conveyed to 404 (steps ST1, ST2, ST4). In the case of the innermost sheet Sa, an image is formed by reversing the innermost sheet Sa in advance and conveyed to the crease imparting section 404 (steps ST1, ST3, ST4).

  When the conveyed sheet is the outermost sheet Sb, the crease application unit 404 determines the crease application position based on the information of the front end detection sensor S2 with reference to the front end of the outermost sheet Sb ( Step ST5). In the crease imparting section 404, as described above, the fold X is imparted to the outermost sheet Sb at the crease imparting position, and the outermost sheet Sb is conveyed to the finisher 500 (step ST7b).

  When the conveyed sheet is the innermost sheet Sa, the crease application unit 404 determines a crease application position based on the information of the rear end detection sensor S3 with reference to the leading edge of the innermost sheet Sa (step). ST5). In the crease imparting section 404, as described above, the fold X is imparted to the innermost sheet Sa at the crease imparting position, and the innermost sheet Sa is conveyed to the finisher 500 (step ST7a). In the crease imparting section 404, when the conveyed sheet is the intermediate sheet Sc, the intermediate sheet Sc is conveyed to the finisher 500 without being creased (steps ST5 and ST6).

  In the finisher 500, when the conveyed sheet is the innermost sheet Sa, the finisher control unit 500a controls the reverse conveyance unit 530 as described above. As a result, the innermost sheet Sa is conveyed to the saddle stitch bookbinding unit 800 with the front and back sides and the front and rear sides reversed (steps ST8, ST9, ST10). In the finisher 500, when the conveyed sheet is not the innermost sheet Sa, the sheet is conveyed to the saddle stitch binding unit 800 without being inverted (steps ST8 and ST10).

  In this way, the sheets are stacked in order from the innermost sheet Sa on the stacking stopper 813 of the saddle stitch binding unit 800, and the main body control unit 60 performs the image forming operation until the outermost sheet Sb is stacked. Continue (steps ST11 and ST12). When the outermost sheet Sb is stacked on the stacking stopper 813, the innermost sheet Sa to the outermost sheet Sb are aligned and stacked on the stacking stopper 813 to form a sheet bundle. The sheet bundle is bound by the stapler 820 and subsequently folded by the folding unit 830 (steps ST11, ST13, ST14).

  Here, a case where a sheet bundle is formed by two sheets when the sheet bundle is folded by the folding unit 830 will be described. As shown in FIG. 10, in the sheet bundle stacked on the stack stopper 813, since the innermost sheet Sa is turned upside down and back and forth, the fold peak side given to the innermost sheet Sa faces the outermost sheet Sb. Composed. In addition, the ridge side of the fold provided to the outermost sheet Sb is stacked on the stacking stopper 813 so as to face the innermost sheet Sa. In this state, the finisher controller 500a drives the extrusion motor M5 to move the extrusion member 834 toward the sheet bundle. The pushing member 834 pushes the sheet bundle toward the nip portion N of the folding roller pair 831, and the sheet bundle is folded by the nip portion N.

  In addition, the front-end | tip of the extrusion member 834 is comprised in the shape which has a curved surface substantially the same as the crease | fold X given to the innermost sheet Sa. Thereby, the pushing member 834 engages with the fold line X given to the innermost sheet Sa, and the relative movement between the pushing member 834 and the sheet bundle can be prevented. Further, since the sheet bundle is fixed by the needle V driven by the stapler 820, relative movement between the pushing member 834 and the sheet bundle when the pushing member 834 pushes out the sheet bundle can be prevented. Therefore, the sheet bundle can be folded accurately, and the quality of the booklet can be improved.

  Further, even when the sheet bundle is formed by three or more sheets, as shown in FIG. 11, the ridges of the folds given to the innermost sheet Sa are stacked on the stacking stopper 813 facing the outermost sheet Sb. ing. In addition, the ridge side of the fold provided to the outermost sheet Sb is stacked on the stacking stopper 813 so as to face the innermost sheet Sa. In this state, the finisher controller 500a drives the extrusion motor M5 to move the extrusion member 834 toward the sheet bundle. The pushing member 834 pushes the sheet bundle toward the nip portion N of the folding roller pair 831, and the sheet bundle is folded by the nip portion N.

  The sheet bundle subjected to folding processing by the folding unit 830 is as shown in FIG. 12A in the case of two sheet bundles, and as shown in FIG. 12B in the case of three or more sheet bundles. A sheet bundle S (booklet) is discharged to the folded bundle discharge tray 850 (step ST15). Through the above-described saddle stitch folding bookbinding operation, the outermost sheet Sb can be folded into a substantially rectangular shape, and the innermost sheet Sa can be obtained a booklet folded in a normal half-fold. Further, the protrusion Z of the outermost sheet Sb is hidden by overlapping the innermost sheet Sa, and the quality of the booklet can be improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. However, with respect to the same configuration as that of the first embodiment, the illustration is omitted or the same reference numerals are given to the drawings and the description is omitted. The second embodiment of the present invention is different from the first embodiment in that there are two crease imparting portions and no reverse conveyance path, and these will be mainly described.

  As illustrated in FIG. 13, the sheet processing apparatus 300 </ b> A includes a crease imparting device 400 </ b> A in which a second crease imparting unit 430 is disposed downstream of the first crease imparting unit 404 </ b> A in the sheet conveyance direction. 404 A of 1st crease provision parts are the structures similar to the crease provision part 404 of 1st Embodiment, and form the crease | fold which becomes a downward convex.

  Moreover, since the 2nd crease provision part 430 is substantially the same structure as 404 A of 1st crease provision parts, only a different part from 404 A of 1st crease provision parts is demonstrated. As shown in FIGS. 14 and 15, the support frame 409 of the second crease imparting portion 430 is formed with a convex portion 431 that protrudes upward, and the lower surface of the slide support member 411 faces the convex portion 431. Thus, a recess 432 is formed. The support frame 409 is provided with an elastic guide 433 to prevent the leading end of the sheet P from coming into contact with the convex portion 431 and being caught when the sheet P is conveyed. Further, when the slide support member 411 is lowered, the guide 433 is bent toward the support frame 409 and does not hinder the engagement by the convex portion 431 and the concave portion 432. And the 2nd crease provision part 430 can form the crease which becomes convex on the sheet | seat P by pinching the sheet | seat P by the convex part 431 and the recessed part 432. FIG.

  Next, the saddle stitch folding and bookbinding operation by the copying machine 1 will be described with reference to the flowchart shown in FIG. When the saddle stitch folding bookbinding operation starts, the main body control unit 60 causes the image forming apparatus main body 100 to form an image on the sheet P, forms an image on the sheet, and then applies the sheet to the first crease imparting unit 404A and the second crease. Transported to section 430 (steps ST16 and ST17).

  If the conveyed sheet is the outermost sheet Sb, the first crease applying unit 404A applies a crease to the outermost sheet Sb, and the outermost sheet Sb is conveyed to the saddle stitch binding unit 800 (step). ST18, ST20b, ST21). When the conveyed sheet is the innermost sheet Sa, the second fold applying unit 430 applies a crease to the innermost sheet Sa, and the innermost sheet Sa is conveyed to the saddle stitch binding unit 800 (step ST18, ST20a, ST21). That is, one of the first crease imparting section 404A and the second crease imparting section 430 is driven depending on whether the conveyed sheet is the innermost sheet Sa or the outermost sheet Sb. When the conveyed sheet is the intermediate sheet Sc, the intermediate sheet Sc is conveyed to the saddle stitch binding unit 800 without giving a crease (steps ST18, ST19, ST21).

  In this way, the sheets are stacked in order from the innermost sheet Sa on the stacking stopper 813 of the saddle stitch binding unit 800, and the main body control unit 60 performs the image forming operation until the outermost sheet Sb is stacked. Continue (steps ST22 and ST23). When the outermost sheet Sb is stacked on the stacking stopper 813, the innermost sheet Sa to the outermost sheet Sb are aligned and stacked on the stacking stopper 813 to form a sheet bundle. The sheet bundle is bound by the stapler 820 and subsequently folded by the folding unit 830 (steps ST22, ST24, ST25). Since the folding process is the same as that of the first embodiment, the description thereof is omitted. The sheet bundle subjected to the folding process by the folding unit 830 becomes a booklet and is discharged to the folded bundle discharge tray 850 (step ST26).

  According to the above-described saddle stitch folding bookbinding operation, the outermost sheet Sb can be folded into a substantially rectangular shape, and the innermost sheet Sa can be obtained a booklet folded in a normal half-fold. Further, the protrusion Z of the outermost sheet Sb is hidden by overlapping the innermost sheet Sa, and the quality of the booklet can be improved. Also, depending on whether the innermost sheet Sa or the outermost sheet Sb, either the first crease imparting part 404A or the second crease imparting part 430 is driven, and a crease is imparted to the first surface or the second surface of the sheet. . As a result, it is not necessary to provide a reverse conveyance path in the conveyance unit 540A, and accordingly, it is not necessary to reverse the front and back of the sheet to form an image. Therefore, the saddle stitch folding and bookbinding operation can be performed efficiently, and the tact time can be shortened.

  In the above-described embodiment, the copying machine has been described as an example of the image forming apparatus. However, for example, other image forming apparatuses such as a scanner, a printer, and a facsimile apparatus, and other multifunction apparatuses that combine these functions are used. The present invention may be applied to an image forming apparatus.

  In the sheet processing apparatus, the crease applying device and the finisher may be provided separately or integrally.

  Further, the transport units 540 and 540A may be controlled by the finisher control unit 500a or the main body control unit 60. Also, the first crease imparting section 404A and the second crease imparting section 430 may be controlled by the crease imparting control section 400a or the main body control section 60.

  Further, in the first embodiment, the arrangement of the convex portions and the concave portions of the crease imparting portion 404 may be upside down, and in that case, the reverse conveyance path 503 may be controlled so that the outermost sheet Sb passes. Moreover, in 2nd Embodiment, arrangement | positioning of the convex part and recessed part of 404 A of 1st crease provision parts and the 2nd crease provision part 430 may be upside down. That is, a fold is given to one of the innermost sheet Sa and the outermost sheet Sb by the first fold giving part 404A, and a crease is given to the other of the innermost sheet Sa and the outermost sheet Sb by the second fold giving part 430. May be given.

  Further, in the saddle stitch binding unit 800, the sheet bundle may be folded without binding with a needle, or the sheet bundle may be bound with glue or string instead of the needle.

1: image forming apparatus (copier), 20: image forming section, 300, 300A: sheet processing apparatus, 400, 400A: crease imparting apparatus, 404: crease imparting section, 404A: first crease imparting section, 412: convex section 413: recessed portion, 430: second crease applying portion, 500a: control portion (finisher control portion), 503: reverse conveying path, 509: sheet processing conveying path, 530: reverse conveying portion, 540, 540A: conveying portion, 810 : Stacking part, 820: Binding part (stapler), 830: Folding part, 831: Pair of rollers (folding roller pair), 834: Extruding member, N: Nip part, P: Sheet, Sa: Innermost sheet, Sb: Outermost sheet, S2: front end position detection unit (front end detection sensor), S3: rear end position detection unit (rear end detection sensor)

Claims (17)

A crease imparting portion for imparting a crease to the sheet;
A stacking unit that bundles and stacks a plurality of sheets with creases provided by the crease applying unit, and forms a sheet bundle;
A conveyance unit capable of conveying the sheet with the crease provided by the crease applying unit to the stacking unit by reversing the front and back and front and back;
A folding part for folding the sheet bundle;
The innermost sheet that is the innermost when the sheet bundle is folded by the folding part, and the ridge side of the fold given by the crease imparting part faces the outermost sheet that is the outermost when the sheet bundle is folded by the folding part. And reverse the front and back and front and back of either the innermost sheet or the outermost sheet so that the ridge of the fold provided by the crease applying portion faces the innermost sheet. And a control unit that controls the transport unit so as to be transported to the stacking unit.
A sheet processing apparatus. The conveyance unit has a sheet processing conveyance path provided between the crease applying unit and the stacking unit, a reverse conveyance path branched from the sheet processing conveyance path, and a sheet conveyed through the sheet processing conveyance path. And a reversing conveyance unit that reverses the front and rear and guides the reversing conveyance path,
The control unit controls the reversal conveyance unit so that either the innermost sheet or the outermost sheet is guided to the reversal conveyance path.
The sheet processing apparatus according to claim 1. A leading edge position detector for detecting the position of the leading edge of the sheet;
A rear end position detector for detecting the position of the rear end of the sheet,
When the control unit applies a crease to the sheet by the crease applying unit, one of the innermost sheet and the outermost sheet is based on the position of the leading edge of the sheet detected by the leading edge position detecting unit. A crease application position for crease the sheet is determined, and either the innermost sheet or the outermost sheet determines the crease application position based on the rear end of the sheet detected by the rear end position detection unit. ,
The sheet processing apparatus according to claim 1 or 2. The crease imparting portion has a convex portion protruding in the sheet conveyance path and a concave portion that engages with the convex portion, and imparts a crease to the sheet by sandwiching the sheet by the convex portion and the concave portion.
The sheet processing apparatus according to any one of claims 1 to 3. A first crease imparting section for imparting a crease to the sheet such that the ridge side of the fold is located on the first surface of the sheet; and a second crease for imparting a crease to the sheet such that the crease side of the fold is located on the second surface of the sheet. A crease applicator having an applicator,
A stacking unit that bundles and stacks a plurality of sheets with creases provided by the crease applicator, and forms a sheet bundle;
A transport unit that transports the sheet with the crease provided by the crease applying device to the stacking unit;
A folding part for folding the sheet bundle;
The innermost sheet that is the innermost side when the sheet bundle is folded by the folding part faces the innermost sheet that is the outermost side when the fold line provided by the crease imparting device is folded by the folding part. In this way, the outermost sheet is selectively driven so that the ridges of the folds provided by the crease application device face the innermost sheet. A control unit,
A sheet processing apparatus. The folding portion includes an extruding member that can extrude a crease provided to the sheet bundle, and a pair of rollers that fold the compressing sheet bundle pushed out by the extruding member at a nip portion.
The sheet processing apparatus according to any one of claims 1 to 5. The tip of the pushing member has a shape that engages with the fold.
The sheet processing apparatus according to claim 6. Before folding the sheet bundle by the folding unit, provided with a binding unit for binding the sheet bundle,
The sheet processing apparatus according to claim 1. An image forming unit for forming an image on a sheet;
A crease imparting section for imparting a crease to a sheet on which an image is formed by the image forming section;
A stacking unit that bundles and stacks a plurality of sheets with folds provided by the crease applying unit;
A conveyance unit capable of conveying the sheet with the crease provided by the crease applying unit to the stacking unit by reversing the front and back and front and back;
A folding part for folding the sheet bundle;
The innermost sheet that is the innermost when the sheet bundle is folded by the folding part, and the ridge side of the fold given by the crease imparting part faces the outermost sheet that is the outermost when the sheet bundle is folded by the folding part. And reverse the front and back and front and back of either the innermost sheet or the outermost sheet so that the ridge of the fold provided by the crease applying portion faces the innermost sheet. And a control unit that controls the transport unit so as to be transported to the stacking unit.
An image forming apparatus. The conveyance unit has a sheet processing conveyance path provided between the crease applying unit and the stacking unit, a reverse conveyance path branched from the sheet processing conveyance path, and a sheet conveyed through the sheet processing conveyance path. And a reversing conveyance unit that reverses the front and rear and guides the reversing conveyance path,
The control unit controls the reversal conveyance unit so that either the innermost sheet or the outermost sheet is guided to the reversal conveyance path.
The image forming apparatus according to claim 9. A leading edge position detector for detecting the position of the leading edge of the sheet;
A rear end position detector for detecting the position of the rear end of the sheet,
When the control unit applies a crease to the sheet by the crease applying unit, one of the innermost sheet and the outermost sheet is based on the position of the leading edge of the sheet detected by the leading edge position detecting unit. A crease application position for crease the sheet is determined, and either the innermost sheet or the outermost sheet determines the crease application position based on the rear end of the sheet detected by the rear end position detection unit. ,
The image forming apparatus according to claim 9 or 10. The crease imparting portion has a convex portion protruding in the sheet conveyance path and a concave portion that engages with the convex portion, and imparts a crease to the sheet by sandwiching the sheet by the convex portion and the concave portion.
The image forming apparatus according to claim 9. The control unit controls the image forming unit to form an image by reversing the front and back in advance with respect to the sheet reversed by the conveying unit.
The image forming apparatus according to claim 9. An image forming unit for forming an image on a sheet;
A first crease-applying unit that applies a crease to the sheet so that a crease crest is located on the first surface of the sheet on which an image is formed by the image forming unit; and a crease crest is disposed on the second surface of the sheet. A crease imparting device comprising: a second crease imparting portion that imparts a crease to the sheet;
A stacking unit that bundles and stacks a plurality of sheets with creases provided by the crease applicator, and forms a sheet bundle;
A transport unit that transports the sheet with the creases provided by the crease applying device to the stacking unit;
A folding part for folding the sheet bundle;
The innermost sheet that is the innermost side when the sheet bundle is folded by the folding part faces the innermost sheet that is the outermost side when the fold line provided by the crease imparting device is folded by the folding part. In this way, the outermost sheet is selectively driven so that the ridges of the folds provided by the crease application device face the innermost sheet. A control unit,
An image forming apparatus. The folding portion includes an extruding member that can extrude a crease provided to the sheet bundle, and a pair of rollers that fold the compressing sheet bundle pushed out by the extruding member at a nip portion.
The image forming apparatus according to claim 9. The tip of the pushing member has a shape that engages with the fold.
The image forming apparatus according to claim 15. Before folding the sheet bundle by the folding unit, provided with a binding unit for binding the sheet bundle,
The image forming apparatus according to claim 9.

Images