Image forming system

Abstract

The present invention aims to provide a device that allows for easy setting of perforation at desired locations when performing corner processing and perforation processing on a folded sheet bundle. [Solution] When performing corner back processing and perforation processing on a folded sheet bundle, the presence or absence of corner back processing is input, the starting position of the perforation processing is predetermined, and then the distance to the perforation processing position is input, thereby enabling perforation at the intended location without causing positional shift due to corner back processing.

Description

Technical Field

[0001] The present invention relates to an image forming system including a sheet processing apparatus that sequentially processes an image-formed sheet, receives the processed sheet to form a sheet bundle, binds the sheet bundle, and (center fold) folds it in half to create a booklet.

Background Art

[0002] In an image forming system, a sheet processing apparatus is usually connected downstream of an image forming apparatus (printer), and a stacking apparatus for stacking the post-processed sheets is further arranged downstream. There is an image forming system in which a plurality of post-processing apparatuses are connected between the image forming apparatus and the stacking apparatus so that a plurality of types of post-processing (in-line processing) can be performed.

[0003] Also, there is a sheet processing apparatus that performs staple processing and folding processing on a sheet bundle to perform sheet bundle processing (bookbinding processing).

[0004] The sheet bundle subjected to this staple processing and folding processing is likely to open due to the elasticity (sheet stiffness) of the sheet.

[0005] For this reason, conventionally, a device has been proposed that applies pressure to the back of a sheet bundle bound by saddle stitching to make the shape of the fold line on the back flat, and is provided downstream of the bookbinding processing device (see, for example, "Patent Document 1").

[0006] Such a process of forming a corner (fold line) on the back of a sheet bundle is widely known as a corner back process.

[0007] Also, continuous punching processing (continuous punch holes, perforations, etc.) in the sheet width direction is performed on both sides of the fold line for folding the sheet bundle to be bookbound in half (center fold), so that the entire bookbound sheet bundle can be filed, or there is a product in which the pages can be cut with perforations. (See, for example, Patent Document 3 and Patent Document 4).

[0008] In the apparatus described in Patent Documents 3 and 4, the position of the fold line is used as a reference, and the device is programmed to perform the perforation process at a position, for example, 10 mm away from this fold line.

[0009] As mentioned above, in the apparatus described in Patent Documents 3 and 4, the perforation position is set to a position of a certain number of millimeters from the center fold line (crease). This is because, in a typical center-folded booklet, the fold line is at the edge of the booklet.

[0010] On the other hand, in the case of the corner spine processing, which processes the shape of the spine of a folded sheet bundle into a flat surface, as described in Patent Document 1, two new folds are formed at the fold made during the initial folding process, and the spine is formed to a fixed size. Therefore, the edge of the booklet is located at the edge of the spine.

[0011] Because the perforation position is set using the fold line described in Patent Documents 3 and 4 as the starting point, when performing corner back processing, a deviation occurs from the intended perforation position. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2011-57363 [Patent Document 2] Japanese Patent Publication No. 2012-56740 [Patent Document 3] Japanese Patent Application Publication No. 9-142728 [Patent Document 4] Japanese Patent Publication No. 2002-68577 [Overview of the project] [Problems that the invention aims to solve]

[0013] When the position of the perforation process is set and then the corner backing process is set to be performed, the formation of the back causes the perforation position to shift from the desired position. The present invention aims to provide a device that allows for easy setting of the perforation process to be performed at the desired position when applying corner backing and perforation processes to a folded sheet bundle. [Means for solving the problem]

[0014] The present invention provides an operation screen for inputting the position of the perforation process after setting whether or not to perform corner back processing and perforation processing on a folded sheet bundle.

[0015] To achieve the above objective, the image forming system of the present invention comprises: an image forming apparatus for forming an image on a sheet; a perforation processing means for performing a plurality of continuous perforations in the sheet width direction on a sheet sent from the image forming apparatus; a saddle-stitching and folding processing means for forming a bundle of perforated sheets sent from the perforation processing means and performing a saddle-stitching and folding process on the sheet bundle, including saddle stitching and folding; a corner back processing unit for pressing the back of the sheet bundle that has undergone saddle-stitching and folding processing in the saddle-stitching and folding processing unit to create two folds; an operation screen in which the user can input the position for performing the perforation processing near the fold position of the sheet and whether or not to perform the corner back processing on the sheet bundle; and a control unit that controls the perforation processing apparatus, the saddle-stitching and folding processing unit and the corner back processing unit based on the information input on the operation screen, wherein the operation screen allows input of whether or not to perform the perforation processing after inputting whether or not to perform the corner back processing. [Effects of the Invention]

[0016] When perforating sheet bundles that are to be processed with a square backing, the user can set the desired perforation position. [Brief explanation of the drawing]

[0017] [Figure 1] A cross-sectional view is shown of an image forming apparatus equipped with a perforation device. [Figure 2] This shows a system block diagram of the image forming apparatus. [Figure 3] Shows a cross-sectional view of the punching device. [Figure 4] Shows a block diagram of the punching device. [Figure 5] The punching unit is also shown as an example. [Figure 6] Shows the punching positions for the first and Nth sheets (with correction of the punching hole positions). [Figure 7] Shows the punching holes of the punched and double-folded booklet (without correction of the punching hole positions). [Figure 8] Shows the punching holes of the punched and double-folded booklet (with correction of the punching hole positions). [Figure 9] Shows a cross-sectional view of the finisher. [Figure 10] Shows a perspective view of the double-folded booklet. [Figure 11] Shows a block diagram of the finisher. [Figure 12] Shows a perspective view of the corner-binding unit. [Figure 13] Shows the side state of the double-folded booklet. [Figure 14] Shows the side state of the double-folded and corner-bound booklet. [Figure 15] Shows a cross-sectional view of the corner-binding part. [Figure 16] Shows the stop position (Example 1) when performing the corner-binding process. [Figure 17] Shows the stop position (Example 2) when performing the corner-binding process. [Figure 18] Shows the control flowchart of the present invention. [Figure 19] Shows the flowchart of the corner-binding feasibility determination process of the present invention. [Figure 20] Shows the setting screen for the saddle-stitched bookbinding. [Figure 21] Shows a perspective view of the punched and double-folded booklet. [Figure 22] Shows a side view of the punched and double-folded booklet. [Figure 23]This shows a side view of a booklet that has undergone perforation, bi-folding, and corner spine finishing (without correction of perforation position). [Figure 24] This shows a side view of a booklet that has undergone perforation, bi-folding, and corner spine finishing (with corrections made to the perforation positions). [Figure 25] This shows a flowchart for adjusting the drilling position (first time) according to the present invention. [Figure 26] This flowchart shows the second drilling position adjustment procedure according to the present invention. [Figure 27] A flowchart for bookbinding settings is shown. [Figure 28] This shows the operation screen when setting up bookbinding. [Figure 29] This shows the operation screen when setting up bookbinding. [Figure 30] A flowchart for bookbinding settings is shown. [Figure 31] This shows the operation screen when setting up bookbinding. [Figure 32] A flowchart for bookbinding settings is shown. [Modes for carrying out the invention]

[0018] Hereinafter, preferred 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 modified depending on the configuration and various conditions of the apparatus to which the present invention is applied. Therefore, unless otherwise specifically stated, the scope of the present invention is not intended to be limited to those embodiments.

[0019] <Image forming apparatus> Figure 1 is a diagram showing the configuration of an image forming apparatus and a sheet processing apparatus. As shown in Figure 1, the image forming apparatus has an image forming apparatus main unit 600 that performs black and white / color image forming, and a sheet processing apparatus connected thereto, which includes a perforating device 200 and a sheet processing apparatus (hereinafter referred to as a finisher 100). Therefore, sheets discharged from the image forming apparatus main unit 600 can be processed by the perforating device 200 and finisher 100 which are connected online. The image forming apparatus main unit 600 can also be used independently without connecting the finisher 100 to the discharge port. Alternatively, the image forming apparatus main unit 600 may integrate the perforating device 200 and finisher 100 as a single sheet discharge apparatus. Here, the position from which the user faces the operation screen 601 to perform various inputs / settings to the image forming apparatus main unit 600 is referred to as the front side of the image forming apparatus (hereinafter referred to as the front side), and the rear side of the apparatus is referred to as the back side. Figure 1 shows the configuration of the image forming apparatus as seen from the front side of the apparatus. The perforating device 200 and the finisher 100 are connected to the side of the image forming apparatus body 600.

[0020] The sheets S supplied from cassettes 909a and 909b within the main body 600 of the image forming apparatus have four-color toner images transferred onto them by the yellow, magenta, cyan, and black photosensitive drums 914a to 914d, which constitute the image forming section. The sheets are then transported to the fuser 904 where the toner images are fixed, and in single-sided image forming mode, they are discharged directly from the discharge roller pair 907 to the outside of the apparatus. In double-sided image forming mode, the sheets S are passed from the fuser 904 to the reversal roller 905, and when the rear end of the sheet in the transport direction passes the reversal switching section P, the reversal roller 905 is reversed, and the sheets are transported in the direction of the double-sided transport rollers 906a to 906f, which are opposite to the transport direction. The four-color toner images are then transferred again to the back side by the yellow, magenta, cyan, and black photosensitive drums 914a to 914d, etc. The sheet S, with the toner transferred to both sides, is then transported back to the fuser 904 to fix the toner image, and is discharged outside the device body via the discharge roller pair 907.

[0021] Figure 2 is a block diagram of the image forming apparatus control unit that controls the image forming apparatus. As shown in Figure 2, the CPU circuit unit 630 has a CPU 629, a ROM 631, and a RAM 655. The CPU circuit unit 630 controls the document feeder control unit 632, the image reader control unit 633, the image signal control unit 634, the printer control unit 635, the finisher control unit 636, the perforation device control unit 638, and the external interface 637. The CPU circuit unit 630 controls according to the program stored in the ROM 631 and the settings of the operation screen 601. The document feeder control unit 632 controls the document feeder 650. The image reader control unit 633 controls the image reader. The printer control unit 635 controls the image forming apparatus main unit 600. The perforation device control unit 638 controls the perforation device 200. The finisher control unit 636 controls the finisher 100. In this embodiment, the perforation device control unit 638 is mounted on the perforation device 200, and the finisher control unit 636 is mounted on the finisher 100. However, the present invention is not limited to this, and the CPU circuit unit 630 may be integrally provided with the main body 600 of the image forming apparatus, so that the perforation device 200 and the finisher 100 are controlled from the main body 600 side. Alternatively, the finisher 100 may be controlled by the control means on the perforation device 200 side, or the perforation device 200 may be controlled by the control means on the finisher 100 side.

[0022] RAM 655 is used as a temporary storage area for control data and as a workspace for calculations related to control. The external interface 637 is an interface from the computer (PC) 620, which converts print data into an image and outputs it to the image signal control unit 634. The image read by the image sensor is output from the image reader control unit 633 to the image signal control unit 634, and the image output from the image signal control unit 634 to the printer control unit 635 is input to the exposure control unit.

[0023] The drilling device control unit 638 is mounted on the drilling device 200 and controls the drive of the entire drilling device by exchanging information with the CPU circuit unit 630 of the image forming apparatus. The finisher control unit 636 is mounted on the finisher 100 and controls the drive of the entire finisher by exchanging information with the CPU circuit unit 630 of the image forming apparatus. The drilling device control unit 638 and the finisher control unit 636 control various motors and sensors.

[0024] Furthermore, the operation screen 601 allows the user to input and configure various settings, such as print job information. For example, the operation screen 601 displays the saddle-stitch binding settings as shown in Figure 20, and the user can individually select whether or not to perform the saddle-stitching process NS, the perforation process SS, and the spine processing KS. Details of the saddle-stitching process, perforation process, and spine processing will be described later.

[0025] <Drilling device> Figure 3 is a cross-sectional view of the perforation device 200. As shown in Figure 3, the perforation device 200 is equipped with a perforation path B that sequentially takes in sheets discharged from the image forming apparatus body 600 and performs perforation processing on the taken sheets, and a bypass A that passes the sheets to the downstream finisher 100 without processing. These paths are switched by a switching member 217.

[0026] The sheet processing in the perforation device 200 operates according to user settings via the operation screen 601 provided on the image forming apparatus main unit 600. While the operation screen 601 uses the user interface of the image forming apparatus main unit, a computer connected to the image forming system may also be used.

[0027] The sheet discharged from the image forming apparatus main body 600 is then passed to the entrance roller pair 202 of the perforating device 200. At this time, the entrance sensor 201 also detects the timing of the sheet transfer.

[0028] If the sheet is not perforated, the switching member 217 switches to bypass A, and the sheet is conveyed by the conveying roller pairs 203, 204, 205 and the discharge roller pair 206, and handed over to the downstream finisher 100.

[0029] When perforating the sheet, the switching member 217 switches to perforation path B, and the sheet is transported to the processing area by transport roller pairs 208, 211, and 252, and the sheet edge detection sensor 213 detects the sheet edge. After stopping the sheet at a predetermined position in the transport direction, the perforation unit 220 is operated to perforate the sheet. The perforated sheet is then transported again by transport roller pairs 209, 210, 214, 215, and 216 and discharge roller pair 206, and handed over to the downstream finisher 100.

[0030] Figure 5 is a cross-sectional view of the perforation unit 220 as seen from downstream in the sheet conveying direction. The die plate 305 has a perforation groove 306. Shaft guides 307a and 307b are mounted on the die plate 305 and slidably support the movable plate 301 and the perforation blade holder 303. The perforation blade 304 is installed in the perforation blade holder 303 and engages with the perforation groove 306 to perforate the sheet. Compression springs 302a, 302b, and 302c are installed between the movable plate 301 and the perforation blade holder 303. When the drive motor M1 pushes down the movable plate 301, the compression springs 302a, 302b, and 302c push down the perforation blade holder 303, causing the perforation blade 304 to engage with the perforation groove 306. The release springs 308a and 308b are springs that push up the compressed drilling blade holder 303. The top dead center of the drilling blade holder 303 is the position where it abuts against the stoppers 309a and 309b, and the top dead center of the movable plate 301 is the position where it abuts against the stoppers 310a and 310b.

[0031] As shown in Figure 4, the perforation device control unit 638 includes a microcontroller (CPU) 701, RAM 702, ROM 703, input / output unit (I / O) 705, communication interface 706, and network interface 704. The transport control unit 707 controls the solenoid SL1 that drives the switching member 217, the transport drive motors M5, M6, M7, the sheet edge detection sensor 213, and the fan motor that drives the fan. The perforation drive control unit 708 controls the perforation drive motor M1. Various sensor signals are input to the input port of I / O 705. The output ports of I / O 705 are connected to various drive systems via control blocks (not shown) and various drivers (not shown).

[0032] In this embodiment, the perforation unit 220 is configured to change the perforation position relative to the midpoint of the sheet in the longitudinal direction, and the perforation unit 220 is configured, for example, to have different perforations for each sheet in one set of sheets to be perforated.

[0033] In the perforating device 200 configured as described above, as shown in Figure 6, when the leading edge of the sheet S is detected by the sheet edge detection sensor 213, the sheet edge detection signal from the sheet edge detection sensor 213 is used as a trigger to transport the sheet S by a distance (lA) according to the sheet size, and the sheet S is stopped so that the perforating blade 304 is positioned a predetermined amount A in front of the leading edge, which is the midpoint of the sheet S in the longitudinal direction, and the perforation process (first time) is performed to make a hole in the sheet S.

[0034] After the first perforation is completed, the transport of sheet S is resumed, and after traveling a distance (2A) of sheet S, it is stopped again, and the second perforation is performed to create holes in sheet S. After the second perforation is completed, the transport of sheet S is resumed.

[0035] Here, the perforating device 200 is configured to change the feed amount for each sheet S when perforating. For example, if the sheet S is plain paper, its thickness is approximately 0.1 mm. For the second sheet S, after the leading edge of the sheet S is detected by the sheet edge detection sensor 213, the sheet S is stopped after traveling a distance of (1A-0.1) and the perforating process (1st time) is performed. After the perforating process (1st time) is completed, the transport of the sheet S is resumed, and the sheet S is stopped again after traveling a distance of (2A+0.2) and the perforating process (2nd time) is performed to create a hole in the sheet S.

[0036] Expressed as an equation, the amount of sheets transported up to the first perforation process X1 is given by X1 = (1A - 0.1 * (N-1)) if the number of sheets S is the Nth sheet, and the amount of sheets transported from the end of the first perforation process to the second perforation process X2 is given by X2 = 2(A + 0.1 * (N-1)). Note that if the sheet S is cardboard, setting the coefficient K in (N-1) in the above equation to around 0.2 instead of 0.1 will allow for control according to the thickness.

[0037] As a result, when a bundle of sheets S that have been perforated by the perforating device 220 is subjected to saddle stitching or other processes as necessary, and then folded, the perforation positions of the bundle of sheets S that have been folded in half or the like will be approximately in a straight line when the sheets are folded, as shown in Figures 8(a) and (b), making it possible to perform the perforation process with high precision.

[0038] <Description of the finisher> The finisher 100 takes in sheets from the image forming apparatus main body 600 that have been transported via the perforating device 200 and processes the taken sheets. For example, it performs sheet processing such as aligning multiple taken sheets and bundling them into a single sheet bundle, stapling the rear end of the sheet bundle, sorting, unsorting, and saddle stitching to create a booklet.

[0039] As shown in Figure 9, the finisher 100 has a transport path 520 for taking sheets conveyed via the perforating device 200 into the device, and the transport path 520 is provided with multiple pairs of transport rollers.

[0040] A switching member 513 located at the end of the transport path 520 switches the route to the upper paper discharge path 521 and the lower paper discharge path 522, which are connected downstream. The upper paper discharge path 521 discharges paper to the upper stack tray 592. On the other hand, the lower paper discharge path 522 discharges paper to the processing tray 550. The sheets discharged to the processing tray 550 are sequentially aligned in the transport direction by the return paddle 552 and return belt 553, which abut the rear end of the sheet against the rear end reference wall 561, and aligned in the width direction by an alignment plate (not shown), and then stored in a bundle. The bundled sheets (sheet bundles) are then sorted and stapled according to the settings from the operation screen 601, and then discharged to the stack trays 591 and 592 by the bundle paper discharge roller pair 551.

[0041] The stapling process described above is performed by a stapler 560, which is movable in the width direction perpendicular to the transport direction and can staple at any position on the sheet. The stack trays 591 and 592 are configured to move vertically, with the upper stack tray 592 receiving sheets from the upper paper output path 521 and the processing tray 550, and the lower stack tray 591 receiving sheets from the processing tray 550. In this way, a large number of sheets can be loaded onto the stack trays 591 and 592, and the loaded sheets are aligned by a rear end guide 593 that extends vertically at their rear ends.

[0042] Next, the configuration of the saddle-stitching unit 800 in the finisher 100 will be described. A sheet switched to the right by a switching member 514 located in the middle of the lower paper output path 522 passes through the saddle paper output path 523 and is sent to the saddle-stitching unit 800. The sheet is handed over to the saddle inlet roller pair 801, and a switching member 802, which is operated by a solenoid according to the size, selects the input port, and the sheet is loaded into the storage guide 803 of the saddle-stitching unit 800. The loaded sheet is transported by the sliding roller 804 until its leading edge contacts the movable sheet positioning member 805. The saddle inlet roller pair 801 and the sliding roller 804 are driven by a motor M21 (see Figure 11). In addition, a stapler (not shown) is provided at an intermediate position in the storage guide 803, facing the storage guide 803. This stapler functions as a saddle-stitching means for saddle-stitching a sheet bundle consisting of multiple sheets. This stapler is divided into a driver 820a that extends the staples and an anvil 820b that bends the extended staples. The sheet positioning member 805 stops when the sheet is being loaded at a position where the midpoint of the sheet's longitudinal direction is the staple position of the stapler. The sheet positioning member 805 is movable under the drive of motor M22 (see Figure 11) and changes its position according to the sheet size.

[0043] Downstream of the stapler (not shown) positioned opposite the storage guide 803, a pair of folding rollers 810a and 810b, which constitute the folding mechanism, are provided. A protruding member 830 is provided opposite the pair of folding rollers 810a and 810b. The home position of this protruding member 830 is when it is retracted from the storage guide 803. Driven by the motor M23 (see Figure 11), the protruding member 830 extends toward the stored sheet bundle, folding the sheet bundle while pushing it into the nip of the folding rollers 810a and 810b. The protruding member 830 then returns to its home position. A sufficient pressure F1 for creating a crease in the bundle is applied between the folding rollers 810a and 810b by a spring (not shown). The folding rollers 810a and 810b and the protruding member 830 constitute a folding mechanism for folding the sheet bundle in half.

[0044] The folded sheet bundles are discharged to the folded bundle discharge tray 850 via the first folding conveyor roller pair 811a, 811b and the second folding conveyor roller pair 812a, 812b, which constitute the corner back processing section 814. Sufficient pressure F2 and F3 are applied to the first folding conveyor roller pair 811a, 811b and the second folding conveyor roller pair (pressure roller pair) 812a, 812b to convey and stop the folded sheet bundles. The shutter 816 moves parallel to the storage guide 803 to a position where the leading edge of the sheet does not come into contact with the folding roller pair 810a, 810b when the sheet is loaded into the storage guide 803, and to a position that clears a path toward the folding roller pair 810a, 810b when the sheet bundle is ejected by the ejector member 830. This movement is driven by the motor M26 (see Figure 11).

[0045] The folding roller pair 810a, 810b, the first folding conveyor roller pair 811a, 811b, and the second folding conveyor roller pair 812a, 812b rotate at a constant speed using the same motor M24 (see Figure 11).

[0046] Furthermore, when folding a sheet bundle fastened with staplers (not shown) positioned opposite each other with a storage guide 803 in between, after the stapling process is completed, the sheet positioning member 805 is lowered a predetermined distance from the stapling position so that the stapled positions of the sheet bundle are at the nip positions of the folding roller pair 810a and 810b. This allows the sheet bundle to be folded with the stapled position as the fold line (mid-length position).

[0047] Furthermore, the alignment plate pair 815 has surfaces that protrude towards the storage guide 803 while rotating around the outer circumferential surfaces of the folding roller pair 810a and 810b, and is an alignment plate pair that aligns the sheet stored in the storage guide 803. Driven by the motor M25 (see Figure 11), the alignment plate pair 815 moves in a clamping direction relative to the sheet, thereby positioning the sheet in the width direction.

[0048] With this configuration, the saddle-stitching unit 800, as shown in Figure 10, saddle-stitches are applied to the middle position (fold) in the longitudinal direction of the sheets, and a booklet St is created, which is a bundle of sheets folded in half at the saddle-stitched position.

[0049] If the sheet stack is thick and the fold is not tight, the resulting booklet St will have a bulging fold Sa, as shown in Figure 13. Conversely, if the sheet stack is thin and can be folded tightly, the resulting booklet may crack at the fold (spine) Sb. This cracking is particularly noticeable if the cover sheet is made of thick cardboard. To mitigate this, a creasing unit is sometimes used to create creases in the fold.

[0050] Next, the corner back processing unit 814 will be described. The corner back processing unit 814 is located downstream in the sheet transport direction of the folding roller pair 810a, 810b and the protruding member 830 that constitute the folding means. The leading edge (back) of the folded sheet bundle is stopped at a predetermined position by the second folding transport roller pair 812a, 812b that constitute the corner back processing unit 814, and then the back is subjected to corner back processing. In this embodiment, the corner back processing unit 814 is incorporated into the finisher 100 as part of the saddle stitching unit 800, but it may also be a separate device located downstream of the saddle stitching unit.

[0051] Figure 12 is a perspective view of the corner spine processing unit 814. A pair of second folding conveying rollers (pressure roller pair) 812a, 812b that grip and pressurize the booklet St from the thickness direction of the booklet, and a spine flattening roller 813 that flattens the spine of the booklet by crushing it from a direction perpendicular to the thickness, are incorporated into the frame 817. The frame 817 is movably supported by a guide part (not shown) that guides it to move parallel to the spine of the booklet, and is driven by a drive part (not shown). As the corner spine processing unit 814 moves, the folded part of the booklet is pressed by the second folding conveying roller pair (pressure roller pair) 812a, 812b while being flattened by the spine flattening roller 813, thereby making it possible to create a booklet with a flat, non-bulging spine as shown in Figure 14.

[0052] Figure 15 is a cross-sectional view of the corner back processing section 814 as seen from the side. As mentioned above, the pressure required for corner back processing to flatten the fold on the back of a folded sheet bundle varies depending on the basis weight and number of sheets forming the folded sheet bundle. In this embodiment, however, the pressure is determined by the stopping position of the folded sheet bundle when corner back processing is performed, more specifically, by how far the leading edge (back) of the folded sheet bundle protrudes from the second folding conveyor roller pair 812a and 812b. In this embodiment, as shown in Figure 15, the distance from the ends of the second folding conveyor roller pair 812a and 812b to the back crushing roller 813 is assumed to be 1.0 mm.

[0053] In corner backing, the more sheets forming a folded sheet bundle and the heavier the basis weight of the sheets, the stronger the pressure required. For example, Figure 16 shows the stopping position when corner backing is applied to a folded sheet bundle consisting of 5 sheets with a basis weight of 52 gsm. In this embodiment, the bundle is stopped when the leading edge (back) of the folded sheet bundle protrudes 1.49 mm from the second folding conveyor roller pair 812a and 812b. In this case, the corner backing will crush (flatten) the back of the folded sheet bundle by (1.49 - 1.0) = 0.49 mm. Figure 17 also shows the stopping position when corner backing is applied to a folded sheet bundle consisting of 30 sheets with a basis weight of 105 gsm. In this embodiment, the bundle is stopped when the leading edge (back) of the folded sheet bundle protrudes 4.96 mm from the second folding conveyor roller pair 812a and 812b. In other words, in this case, the back of the folded sheet bundle will be crushed (flattened) by (4.96-1.0)=3.96mm due to the corner backing process. Thus, when stronger pressure is required, the pressure necessary for corner backing is optimized by changing the stopping position of the leading edge (back) of the folded sheet bundle, such as by increasing the amount that it protrudes from the second folding conveyor rollers 812a and 812b.

[0054] As shown in Figure 11, the finisher control unit includes a microcontroller (CPU) 741, RAM 742, ROM 743, input / output unit (I / O) 745, communication interface 746, and network interface 744. The transport control unit 747 performs the transport process. In the intermediate processing tray control unit 748, the movement of the front and rear alignment plates of the processing tray 550, the rotation of the return paddle, and the rotation of the bundle discharge roller are controlled by a home position detection sensor and a drive motor, respectively. In the binding control unit 749, the clinching and movement of the stapler are controlled by a home position detection sensor and a movement motor, respectively. In the saddle stitch binding control unit 750, the movement of the alignment plate, the rotation of the folding transport roller, the movement of the protruding member, the sheet positioning, the stapler clinching, and the additional folding unit are controlled by a home position detection sensor and a movement motor. Various sensor signals are input to the input port of I / O 745. The output ports of the I / O745 are connected to various drive systems via control blocks (not shown) and various drivers (not shown).

[0055] However, in the case of the conventional technology described above, when a square spine treatment is applied to a folded sheet bundle that has perforations near the spine to flatten the shape of the fold at the spine, the amount of compression of the spine of the sheet bundle due to the square spine treatment is not taken into account. As a result, the perforation position of the folded sheet bundle (a booklet with saddle stitching) is shifted from the expected perforation position by the amount of compression of the spine of the sheet bundle due to the square spine treatment.

[0056] Therefore, in the present invention, when applying corner backing to a folded sheet bundle, the above-mentioned problem is solved by applying multiple perforations at positions approximately symmetrical to the midpoint of the longitudinal direction of the sheet, and correcting for the amount of compression of the back of the sheet bundle due to corner backing. Figures 18, 19, 25, and 26 are flowcharts for explaining the present invention. Unless otherwise specified, the following operations are performed by the CPU 701 (hereinafter referred to as CPU 701) provided in the perforation device control unit 638, or the CPU 741 (hereinafter referred to as CPU 741) provided in the finisher control unit 636.

[0057] When the printing process is executed, CPUs 701 and 741 acquire print job information notified by the CPU circuit unit 630 of the image forming apparatus control unit (S101).

[0058] Next, when the sheet is discharged from the image forming apparatus main body 600 to the perforating device 200, the CPU 701 receives the sheet and transports it into the perforating device 200 (S102).

[0059] The CPU 701 determines whether or not to perform a perforation process on the sheet to be transported based on the job information acquired in S101 (S103). If it is determined that no perforation process should be performed (S103:N), the process proceeds to S105. If it is determined that perforation should be performed (S103:Y), the CPU 701 stops the sheet at a predetermined position in the perforation path B in S104, and then performs the perforation process on the stopped sheet using the perforation motor M1. Details of this perforation process will be described later.

[0060] Subsequently, in S105, CPUs 701 and 741 determine whether the destination for the sheet is the saddle tray 850. If it is determined that the destination is not the saddle tray 850 (S105:N), then in S107, they further determine whether the destination is the upper stack tray 592. If it is determined that the destination is the upper stack tray 592 (S107:Y), CPUs 701 and 741 re-transport the stopped sheet and discharge it into the upper stack tray 592 (S108) to terminate the process. Also, in S107, if it is determined that the destination is the lower stack tray 591 (S107:N), CPUs 701 and 741 re-transport the stopped sheet and discharge it into the lower stack tray 591 (S109) to terminate the process.

[0061] On the other hand, if it is determined in S105 that the destination for the sheets is the saddle tray 850 (S105:Y), the stopped sheets are re-transported and accumulated in the saddle processing tray (S106) to form a sheet bundle. Furthermore, the CPU 741 determines in S110 whether or not the accumulated sheets are the final sheets.

[0062] In S110, if it is determined that the accumulated sheet is not the final sheet of the unit (S110:N), the process is terminated. If it is determined that the sheet is the final sheet of the unit (S110:Y), the process is then determined to determine whether or not to perform a binding process on the formed sheet bundle (S111).

[0063] If it is determined in S111 to perform a binding process (S111:Y), the CPU 741 performs a binding process on the sheet bundle using a stapler (S112) and proceeds to S113. On the other hand, if it is determined in S111 not to perform a binding process (S111:N), the CPU 701 proceeds to S113 without performing a binding process on the sheet bundle.

[0064] Subsequently, the CPU 741 performs a thrusting process on the sheet bundle in S113 and a folding process in S114 to form a folded sheet bundle.

[0065] Next, the CPU 741 determines whether or not to perform corner backing on the folded sheet bundle based on the job information obtained in S101 (S115). If it is determined that corner backing should not be performed on the folded sheet bundle (S115:N), the CPU 741 terminates the process by discharging the folded sheet bundle into the saddle tray 850 in S117 without performing corner backing. On the other hand, if it is determined that corner backing should be performed (S115:Y), the CPU 741 performs corner backing in S116, and then terminates the process by discharging the folded sheet bundle into the saddle tray 850 in S117.

[0066] Next, the perforation process in the present invention will be explained using the flowcharts in Figures 19, 25, and 26.

[0067] In the perforation process according to the present invention, the CPU 701 first detects the leading edge of the sheet with the sheet edge detection sensor 213 (S201), and in S202, performs perforation position adjustment (1st time) and calculates the sheet transport distance X1' (stop position) from the sheet edge detection sensor 213 for performing the perforation process (1st time).

[0068] In the first perforation position adjustment, the CPU 701 first calculates the sheet transport distance X1 after detecting the leading edge of the sheet using the sheet edge detection sensor 213, in the same way as in conventional technology, in S301. The amount of sheets transported up to the first perforation process X1 at this time is expressed as X1 = (1A - 0.1 * (N - 1)) if the sheet S is the Nth sheet, as described above. For example, if the sheet is cardboard instead of plain paper, setting the coefficient K in (N - 1) in the above formula to around 0.2 instead of 0.1 will enable control according to the thickness.

[0069] Next, in S302, the CPU 701 determines whether or not to perform corner back processing on the folded sheet bundle. If it is determined that corner back processing should not be performed (S302:N), the sheet transport distance X1' (stopping position) from the sheet edge detection sensor 213 for performing the first perforation process is determined as the final sheet transport distance X1' (stopping position) without any special correction processing (S304).

[0070] On the other hand, if it is determined in S302 to perform corner back processing (S302:Y), the CPU 701 corrects the distance of the back of the folded sheet bundle that will be crushed by the corner back processing (crushing amount O) from the job information acquired in S101, and determines the sheet transport distance X1' (stopping position) from the sheet edge detection sensor 213 for performing the first perforation process (the sheet transport distance X1' at this time is expressed as X1' = X1 - crushing amount O). Furthermore, as described above, the crushing amount O is 0.49 mm in the case of applying corner back processing to a folded sheet bundle consisting of 5 sheets with a basis weight of 52 gsm, and 3.96 mm in the case of applying corner back processing to a folded sheet bundle consisting of 30 sheets with a basis weight of 105 gsm, and in this embodiment, the sheet transport distance X1' is corrected by the amount of this crushing amount O.

[0071] In S202, once the sheet transport distance X1' is determined, the CPU 701 transports the sheet for the sheet transport distance X1' in S203, then stops the sheet, and in S204, performs the first perforation process on the stopped sheet.

[0072] In S204, once the sheet has undergone the first perforation process, the CPU 701 starts transporting the sheet again in S205, and then in S206 calculates the sheet transport distance X2' (stopping position) for the second perforation process.

[0073] In the second perforation position adjustment, CPU 701 first calculates the sheet transport distance X2 after the first perforation in S401, similar to conventional technology. The transport amount X2 up to the second perforation is expressed as X2 = 2(A + 0.1 * (N - 1)) if sheet S is the Nth sheet, as described above. For example, if the sheet is cardboard instead of plain paper, setting the coefficient K in (N - 1) in the above formula to around 0.2 instead of 0.1 will enable control according to the thickness.

[0074] Next, in S402, the CPU 701 determines whether or not to perform corner back processing on the folded sheet bundle. If it is determined that corner back processing should not be performed (S402:N), the sheet transport distance X2' (stopping position) for performing the perforation process (second time) is determined as the sheet transport distance X2 calculated above, without any special correction processing (S404).

[0075] On the other hand, if it is determined in S402 to perform corner back processing (S402:Y), the CPU 701 corrects the distance of the back of the folded sheet bundle that will be crushed by the corner back processing (crushing amount O) from the job information acquired in S101, and determines the sheet transport distance X2' (stopping position) for performing the perforation process (second time) (the sheet transport distance X2' at this time is expressed as X2' = X2 + crushing amount O). Furthermore, as described above, the crushing amount O is set to 0.49 mm in the case of applying corner back processing to a folded sheet bundle consisting of 5 sheets with a basis weight of 52 gsm, and to 3.96 mm in the case of applying corner back processing to a folded sheet bundle consisting of 30 sheets with a basis weight of 105 gsm, and in this embodiment, the sheet transport distance X2' is corrected by the amount of this crushing amount O.

[0076] In S206, once the sheet transport distance X2' is determined, the CPU 701 transports the sheet for the sheet transport distance X2' in S207, stops the sheet, and in S208 performs a second perforation on the stopped sheet. Then, in S209, the sheet is transported again, and the perforation process is completed.

[0077] As described above, in the present invention, when applying a corner spine treatment to a folded sheet bundle, by performing multiple perforations at positions approximately symmetrical to the midpoint of the sheet in the longitudinal direction, and by correcting for the amount of compression of the spine of the sheet bundle due to the corner spine treatment, it is possible to prevent the perforation positions of the folded sheet bundle (booklet with saddle stitching treatment) from being misaligned, as shown in Figure 24.

[0078] A more preferred embodiment for setting the perforation position when performing corner spine processing will be described in detail. This will be explained in accordance with the flowchart in Figure 27. Figure 27 shows the sequence of display of saddle-stitch binding settings on the operation screen, including corner spine processing and perforation processing (screen display flow).

[0079] Once the user has configured the system to perform saddle binding, also known as saddle stitching and folding, the next step is to select whether or not to perform corner spine processing (St401).

[0080] Next, you set whether or not to perform perforation, that is, the aforementioned center punch or center perforation process (St402).

[0081] Next, a drilling position input screen is displayed on the operation screen, but this drilling position input screen differs depending on whether corner back processing is performed (St403) or corner back processing is performed (St404).

[0082] First, let's explain how the operation screen looks when the corner back processing shown in Figure 28 is not performed. When corner back processing is not performed, the punching position is set to start from the fold line L of the center fold, and the user inputs how many millimeters away from the starting position the punch should be. In this embodiment, the position a where the punch hole or perforation M is formed is set to 10 mm, and the operation screen is displayed in a way that makes it clear that the user is setting the distance from the center fold line to the perforation.

[0083] Next, we will explain the display of the operation screen when performing the corner back processing shown in Figure 29. In corner back processing, the operation screen is designed so that the user inputs the distance a from one end K of the position where the back is formed to the drilling position. This is to prevent the back from becoming shorter than the intended dimensions by the length b of the back, as would be the case if the fold line were used as the starting position in the case of corner back processing, as described above.

[0084] The operation screen shown in Figure 29 is characterized by its ability to display the spine length (in mm) created by the corner spine processing. The dimension of this spine portion b can be set uniformly to, for example, 4 mm, or the spine length can be pre-recorded in a table based on the basis weight and number of sheets forming the sheet bundle, and the spine dimension can be displayed based on the basis weight and number of sheets entered by the user. Note that the spine length tends to increase as the basis weight increases and as the number of sheets increases.

[0085] As shown in Figure 29, the user can input the distance from one end K of the spine, which is the starting point, to the perforation position. This eliminates the need to manually calculate the perforation position while considering the spine, which was previously required, making it easy to input the position.

[0086] The flowchart in Figure 30 and Figure 31 show different operation screens when performing corner back processing. In this screen, the amount of mm of spine created by corner back processing is displayed, and the starting position for inputting the drilling position is displayed as a center fold line L, just as when corner back processing is not performed (St501). In this case, the user sets the distance to the drilling position after recognizing the dimension b of the spine created by corner back processing. Since the effect of spine length can be visually recognized without changing the operation depending on whether corner back processing is performed or not, the user may be allowed to select a display format that is easy for them to understand.

[0087] Another embodiment will be described with reference to the flowchart in Figure 32. In this embodiment, regardless of whether or not corner backing is performed on the sheet bundle to be perforated, the user only needs to input the distance from the edge of the sheet bundle, and the optimal starting position is automatically set.

[0088] If the user selects saddle stitching and center folding, the perforation position setting process begins (St601). If perforation is to be performed, the perforation position information entered by the user is obtained (St602). Next, it is checked whether or not a corner spine processing is to be performed (St603). If a corner spine processing is to be performed, the starting position is changed to the corner spine position (St604), and the spine dimensions are obtained from a table that stores in advance how many mm the spine will be depending on the basis weight and number of sheets forming the sheet bundle (St605). Subsequently, half of the spine dimension information is added to the perforation position information to update the information (St606), and the perforation process is performed accordingly.

[0089] In this embodiment, the user only needs to set the distance from the edge of the sheet bundle, and the device automatically calculates the deviation due to the spine dimensions based on the information regarding whether or not corner spine processing is performed, so the processing details can be entered with simple operation.

[0090] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the present invention. All technical matters included in the technical concept described in the claims are covered by the present invention. [Explanation of Symbols]

[0091] S Seat Sb Folding section (back) St. Folded sheet bundle (booklet) 100 Finisher (component of post-treatment device) 200 Drilling device (component of post-processing device) 217 Switching component 220 Drilling Unit 600 Image forming apparatus main unit 601 Operation screen 630 CPU circuit section 635 Printer Control Unit 636 Finisher Control Unit 638 Drilling device control unit 800 Saddle Stitching Division 810a, 810b folding roller pair 811a, 811b First folding conveyor roller pair 812a, 812b Second folding conveyor roller pair 813 Back-crushing roller 814 Corner back section 815 Matching board pair 820 Staple 830 Protruding member

Claims

1. An image forming apparatus that forms an image on a sheet, A perforation processing means for performing a series of continuous perforations in the sheet width direction on a sheet sent from the image forming apparatus, A saddle-stitching and folding processing means forms a bundle of perforated sheets sent from the perforation processing means and applies a saddle-stitching and folding process, including saddle stitching and folding, to the sheet bundle. The aforementioned saddle-stitching and folding processing unit presses the spine of the sheet bundle that has been saddle-stitched and folded to perform a corner-spine processing that creates two folds, An operation screen in which the user can input the position where the perforation process is performed near the center-fold position of the sheet, and whether or not the corner back processing is performed on the sheet bundle, Based on the information entered on the operation screen, the system comprises the perforation processing device, the saddle-stitch folding processing device, and the corner spine processing device, The aforementioned operation screen is an image forming system that allows input whether or not the corner back processing is performed, after inputting whether or not the perforation processing is performed.

2. The image forming system according to claim 1, wherein the control unit changes the position display for the perforation process shown on the operation screen based on the information about whether or not the corner back processing is performed, which is input to the operation screen.

Images