JP4557846B2 - Sheet processing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet processing apparatus capable of receiving a sheet discharged from an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine or a business machine and performing a so-called bookbinding process.

  Each sheet discharged from an image forming apparatus such as a copying machine, a printer, or a facsimile machine is received one by one to form a sheet bundle, and a staple binding process is performed on the fold line of the formed sheet bundle. A sheet processing apparatus capable of so-called bookbinding processing that folds a bundle of sheets along a folding line (bundle folding) has been put into practical use. In some models of the image forming apparatus, a sheet processing apparatus capable of bookbinding processing is integrated or connected as a purchase option (so-called option).

  Many of the sheet processing apparatuses capable of bookbinding processing include a so-called end binding process in which one end of a formed sheet bundle is stapled, a simple stacking process in which sheets are simply stacked one by one without forming a sheet bundle, It is possible to execute by selecting one from several processing menus such as a punching process for forming a hole for a file in a sheet or sheet bundle.

  In the sheet processing apparatus disclosed in Patent Document 1, a dedicated processing unit that performs bookbinding processing is disposed below a general-purpose processing unit that can perform edge binding processing and simple stacking processing. A process can be selected and executed.

  In the sheet processing apparatus disclosed in Patent Document 2, a folding mechanism for folding a sheet bundle in half is disposed on the back side of a processing tray that receives sheets one by one to form a sheet bundle, and performs an end binding process. The saddle stitching device is used to perform the saddle stitching process in the bookbinding process.

  The sheet processing apparatus shown in Patent Document 3 has a discharge path that conveys a sheet bundle that has been folded in half to a position that overlaps with a sheet that is simply stacked. It is loaded onto a fixed dedicated loading tray through this discharge path.

  An image forming apparatus disclosed in Patent Document 4 is housed in a plane of an image reading apparatus under an image reading apparatus (scanner apparatus), and an image forming unit using a photosensitive drum, a processing tray for forming a sheet bundle, and a liftable unit. A stacking tray is arranged, and after binding the rear end side of the sheet bundle formed by stacking sheets on the processing tray, the sheet bundle is discharged from the processing tray to the stacking tray and stacked.

Japanese Patent Laid-Open No. 10-279163 JP 2001-72310 A JP 2003-241578 A JP 2001-72311 A

  In recent years, in order to save the installation space of the image forming apparatus including the sheet processing apparatus and increase the degree of freedom of the indoor layout around the installation space, downsizing of the image forming apparatus including the sheet processing apparatus is desired. As described above, image forming apparatuses that narrow the number of possible sheet processes and enable sheet bundles to be discharged into the cylinder have been commercialized.

  However, in the image forming apparatus that performs in-cylinder discharge, the stacking space for sheets and sheet bundles is secured in the plane of the apparatus while suppressing the overall height of the apparatus, so the arrangement space of the mechanism in the sheet processing apparatus is limited. Further, it is impossible to additionally arrange a dedicated processing unit that performs bookbinding as shown in Patent Document 2.

  However, providing only a dedicated processing unit that performs bookbinding processing, which is only an additional function convenient for a normal user, and eliminating the essential general-purpose processing unit greatly impairs the merchantability of the image forming apparatus. .

  Therefore, as shown in Patent Document 2, it has been proposed to perform a saddle stitching process in a bookbinding process using a staple binding apparatus that performs an end binding process of a sheet bundle. In this case, the number of staple binding apparatuses However, the length and floor area of the sheet processing apparatus is larger than that of the sheet processing apparatus shown in Patent Document 1 because a space for moving a large sheet before folding in half in the horizontal direction is required in the cylinder. Will become even larger.

  In addition, since the sheet bundle that has been folded in two is loaded in a stacking location different from the lifting type stacking tray that stacks the edge-bound sheet bundle, when mounted on a sheet processing apparatus that performs in-cylinder discharge, If the total height of the sheet processing apparatus cannot be reduced and two stacking places are forcibly secured, the stacking places become narrower and the full load is accelerated, and the sheet bundle is frequently taken out.

  However, in recent years, with the improvement of color printing accuracy of image forming devices, the opportunity to create presentation materials and booklet materials including photographs has increased, and ordinary sheets that can be bound are processed. If bookbinding processing can be incorporated into the processing device, the merchantability of the sheet processing device and the image forming device will be greatly increased, and if the number of components can be reduced and the device can be made compact, lightweight, and low price, it will stimulate great demand for the image forming device. can do.

  SUMMARY OF THE INVENTION A first object of the present invention is to provide a low-cost sheet processing apparatus that is compact, lightweight, and versatile, enabling bookbinding processing by using more members and mechanisms of a sheet processing apparatus that performs edge binding processing. It is.

  The second object of the present invention is to discharge the bookbinding-processed sheet bundle into the stacking space of the edge-bound sheet bundle and stack it efficiently, thereby allowing the interior of the sheet processing apparatus (planar surface of the image forming apparatus). And a small sheet processing apparatus that suppresses the overall height and floor area while securing a loading space having a practical loading capacity.

The sheet processing apparatus according to the present invention includes a sheet stacking unit capable of stacking sheets and sheet bundles , a transport path for transporting sheets stacked on the sheet stacking unit, and the transport path. A bundle forming unit capable of forming a sheet bundle by superimposing received sheets, and a sheet bundle formed by the bundle forming unit disposed in the conveyance path between the bundle forming unit and the sheet stacking unit the direction of one end stapling possible stapling means, discharging means for loading and discharging the sheet bundle of one end is stapled into the sheet stacking means and conveyed sheet by said stapling means the transport path It is equipped with. The needle binding means is capable of needle binding on a fold line when the sheet bundle formed by the bundle forming means is folded in two, and the conveyance path between the bundle forming means and the needle binding means The sheet bundle that is branched from the center and is saddle-stitched on the fold line by the needle binding means is fed back to the upstream side, so that the acceptable branch path and the sheet bundle received in the branch path are separated by the fold line. A bi-folding means for folding the sheet, and a discharge path for guiding the sheet bundle discharged in a double-folded state from the bi-folding means to the conveyance path between the staple binding means and the discharge means, and merging means for a sheet bundle discharged in two-folded state is merged into the discharge means from said bundling means, said stapling means, and Tantsuzuri loading the sheet bundle of the controls the discharge means sheet And a control means for selectively executing the process and the binding process.

  In the sheet processing apparatus of the present invention, the bound sheet bundle is guided to the discharge means by the merging means and is stacked on the sheet stacking means by the discharge means. The sheet bundle that has been bound is discharged and stacked as it is, and there is no need to separately provide a dedicated discharge unit and sheet stacking unit. Therefore, a space lower than the discharge means is used in common, and the sheet bundle can be efficiently stacked in both the edge binding process and the bookbinding process, and the overall height and floor are secured while ensuring a stacking space with a practical capacity in the cylinder. A small sheet processing apparatus with a reduced area can be realized.

  Further, since the bundle forming means and the needle binding means used in the edge binding process are used as they are in the bookbinding process with only the positioning of the sheet bundle being changed, it is necessary to provide a bundle forming means and a needle binding means dedicated to the bookbinding process. There is no.

  In the sheet processing apparatus of another invention, the sheet is buffered in the sheet conveyance path to form a sheet bundle, and therefore it is necessary to provide a sheet bundle forming space independent from the conveyance path such as the processing tray shown in Patent Document 2. No. Further, since the upstream end of the sheet is sandwiched by the sandwiching means to withstand the friction of the succeeding sheet, a considerable number of sheet bundles can be formed even in a narrow conveyance path.

  In the sheet processing apparatus according to still another aspect of the invention, the bi-folding means is arranged on the branch path branched from the conveyance path to the upstream side, so that the sheet bundle can be pulled back from the staple binding means side and folded in half. The moving distance of a large sheet bundle before folding can be designed to be short (the interference area is narrow).

  Further, since the branch path is branched to the upstream side, when the sheet is folded in half while leaving a part of the sheet bundle before the folding in the conveyance path, the resistance when the sheet bundle is drawn into the branch path along with the folding ( Bending and friction) are less than when branching downstream.

  In addition, since the radius that connects the conveyance path and the branch path can be set smaller than the case where it is branched downstream, the mechanism of the two-folding means (eg, a bundle folding roller) can be arranged at a position close to the conveyance path, The overall length is shortened, and the amount of movement when positioning the sheet bundle to the bi-folding means can be reduced.

  And since the bi-folding means is arranged on the branch path independent from the conveyance path, the spatial arrangement and performance of the bi-folding means can be achieved without affecting the arrangement of the devices on the conveyance path such as the staple binding means and the conveyance roller. It can be optimized, and the housing structure with reduced overall height and floor space can be designed.

  Hereinafter, a sheet processing apparatus 400 according to an embodiment of the present invention and a copying machine 500 as an embodiment of an image forming apparatus including the sheet processing apparatus 400 will be described with reference to the drawings. The image forming apparatus of the present invention is not limited to the copying machine 500 of the present embodiment, and may be implemented by a facsimile, a printer, a complex machine of these, or the like.

  Further, the sheet processing apparatus 400 according to the present embodiment is not limited to an electrostatic printing type image forming apparatus such as the apparatus main body 500A of the copying machine 500, but other image forming apparatuses such as an image forming apparatus using ink, An ink jet image forming apparatus, a printing apparatus, or the like can be connected, and the image forming system is not limited.

  In addition, the sheet processing apparatus 400 of the present embodiment may be configured as a separate casing that can be attached to and detached from the apparatus main body 500A, or may be incorporated in the casing of the apparatus main body 500A so as not to be separable. It may be implemented as an automatic saddle stitch bookbinding machine that is covered with a single frame and combined with an automatic paper feeder or the like, and further, as a saddle stitch bookbinding machine that manually inserts sheets one by one.

  In the present embodiment, the control unit 600 that controls the apparatus main body 500A controls each unit related to sheet processing, but the sheet processing apparatus 400 includes another microcomputer control device that is independent from the control unit 600. The sheet processing may be controlled while performing bidirectional communication with the control unit 600.

  In the following description, the upstream end in the sheet conveying direction of the sheet is the rear end, the downstream end is the leading end, the end along the sheet conveying direction is the side end, and the direction intersecting the sheet conveying direction is the sheet. Aligning the rear end of the sheet is the rear end alignment, and aligning the side end is the side end alignment.

<Image forming apparatus>
FIG. 1 is a front view of a copying machine provided with a sheet processing apparatus according to an embodiment of the present invention. The copier 500, which is an image forming apparatus of the present invention, includes an apparatus main body 500A, which is an image forming unit, and a sheet processing apparatus 400, which is a processing unit.

  As shown in FIG. 1, the copier 500 collects an image forming printer unit 200 in an apparatus main body 500A, and an end of an image-formed sheet between a reader unit 120 that reads an image of a document and the apparatus main body 500A. A sheet processing apparatus 400 that can perform binding processing and bookbinding processing is provided. An automatic document feeder 300 (hereinafter referred to as “ADF”) that feeds documents one by one onto the platen glass 102 is attached to the upper portion of the apparatus main body 500A so as to be openable and closable rearward.

  The copying machine 500 functions as a copying machine that copies a document image read by the reader unit 120 to a sheet by the printer unit 200, and also receives image data sent from an external personal computer or the like by the printer unit 200 and forms a sheet. It also functions as a printer that prints images. Further, the copier 500 also functions as a facsimile that transmits a facsimile signal of an original image read by the reader unit 120 to another facsimile, or receives a facsimile signal from another facsimile and prints it by the printer unit 200. To do.

  When copying a plurality of originals, the originals are stacked on the ADF 300, sequentially conveyed to the reader unit 120 one by one, and passed over the stopped scanner unit 104 to perform so-called flow reading. When copying a document that cannot be handled by the ADF 300, the ADF 300 is opened rearward, the document is placed on the platen glass 102, and the scanner unit 104 is moved in the left-right direction in the figure to perform so-called scanning reading.

  In any case, the image of the band-like region illuminated by the light source 103 of the scanner unit 104 is imaged on the CCD image sensor unit 109 via the mirrors 106 and 107 and the optical system 108, and a line image is formed by the CCD image sensor unit 109. It is read and converted into an image signal, and digital processing such as image data conversion and image processing is performed.

  The digitally processed image data is transmitted to the exposure control unit 201 of the printer 200, developed, modulated, and converted into an optical signal of laser light. The exposure control unit 201 scans the optical signal of the laser beam and irradiates the photosensitive drum 202, and an electrostatic latent image is formed on the surface of the photosensitive drum 202 by the irradiation light, and the developing unit 203 causes the toner to adhere. The latent image is developed to form a toner image on the photosensitive drum 202.

  The sheet is conveyed from the sheet cassettes 204 and 205 in synchronization with the leading edge of the toner image, and the toner image is transferred to the sheet by the transfer unit 206. The toner image transferred to the sheet is fixed to the sheet by being subjected to high temperature and pressure at the fixing unit 207. In the case of single-sided printing, the sheet that has been fixed is transferred to the sheet processing apparatus 400 through the sheet discharge unit 208.

  However, in the case of double-sided printing, the sheet on which one side has been fixed is sent from the sheet discharge unit 208 to the reverse path 210, conveyed in a switchback manner, and sent again to the transfer unit 206 in a reverse state. Then, the sheet on which the toner image is transferred also on the back surface is transferred to the sheet processing apparatus 400 through the sheet discharge unit 208 after the toner image is fixed by the fixing unit 207.

  The sheet processing apparatus 400 is disposed without protruding from the plane of the apparatus main body 500A including the sheet bundle stacking unit 470, and performs simple stacking processing and image stacking by discharging sheets on which images are formed one by one onto the stacking unit 470. One of the three processes is formed by stacking the formed sheets to form a sheet bundle, and then binding the end of the formed sheet bundle, and the bookbinding process of folding the center of the formed sheet bundle into two after folding. Can be selected and executed.

  Regardless of which process is selected, sheets and sheet bundles are stacked on a common stacking unit 470, and even a sheet bundle obtained by binding a maximum-size (A3) sheet that can be handled does not protrude from the plane of the apparatus main body 500A. 470 can be loaded.

<Sheet processing device>
2 is an explanatory diagram of the configuration of the sheet processing apparatus, FIG. 3 is a perspective view of a driving mechanism of the conveying roller, FIG. 4 is an explanatory diagram of positioning of the conveying direction alignment reference portion, and FIG. 5 is an operation of the conveying direction alignment reference portion. FIG. The sheet processing apparatus 400 according to this embodiment includes, for example, a stacking unit 470 that is a sheet stacking unit, a conveyance direction alignment reference unit 430 that is a bundle forming unit, a stapler 480 that is a staple binding unit, and a veneer plate that is a bi-folding unit, for example. 445, for example, a discharge roller 410c that is a discharge unit, and a discharge path 451 that is a junction unit, for example.

  As shown in FIG. 2, the sheet discharged from the apparatus main body 500A is guided to the stapler 480 through the conveyance path 436, guided to the nip between the discharge roller 410c and the discharge roller 410g through the conveyance path 437, and rotated. Is discharged to the stacking portion 470 by the discharge roller 410c.

  The conveyance rollers 410a and 410b and the discharge roller 410c that convey the sheet along the normal conveyance paths 436 and 437 are rotationally driven by a common pulse motor (not shown) and rotated by a conveyance roller driving mechanism 418 shown in FIG. Controlled. The transport rollers 410a and 410b and the discharge roller 410c are supported so that their rotation shafts are rotatable, and can contact and separate from the transport path wall surfaces 410e and 410f and the discharge roller 410g, respectively.

  A conveyance direction alignment reference unit 430 that aligns sheets in the conveyance direction is disposed on the entrance side of the conveyance path 436. The conveyance direction alignment reference unit 430 buffers a plurality of sheets in the conveyance path 436 by sandwiching and overlapping the upstream side (rear end) of the sheets received one by one in the conveyance path 436.

  The conveyance direction alignment reference part 430 is adjusted to the sheet size by the conveyance direction alignment reference part rotation mechanism 435 within the range from the rotation position shown in FIG. 4A to the rotation position shown in FIG. It is positioned at the corresponding rotation position. In other words, by positioning the conveyance direction alignment reference portion 430, the staple binding position of the stapler 480 is automatically positioned on the folding line at the center of the sheet bundle sandwiched by the conveyance direction alignment reference portion 430, and after the bundle formation Saddle stitching by the stapler 480 is immediately performed without additional positioning movement.

  The alignment unit 420 is a pair of members supported so as to be movable in a direction perpendicular to the paper surface, and reciprocates up to the sheet width interval to align the sheet width direction. The discharge roller 410c is in pressure contact with the discharge roller 410g to form a discharge roller pair, and discharges and stacks the sheet conveyed on the conveyance path 437 and the end-bound sheet bundle to the stacking unit 470.

  A conveyance direction switching unit 441 is disposed at an upstream position of the stapler 480. The conveyance direction switching unit 441 opens the branch path 440 after the saddle-stitched sheet bundle is conveyed to the stapler 480 and opens the branch path 440, thereby enabling switchback conveyance of the sheet bundle to the branch path 440.

  Near the entrance of the branch path 440, bundle folding rollers 446a, 446b are arranged. The bundle folding rollers 446a and 446b are rotationally driven by a folding roller driving mechanism 447, and the rotation direction and the contact state are controlled.

  The folding roller driving mechanism 447 supports the bundle folding roller 446b so as to be able to be pressed and separated from the bundle folding roller 446a, and presses the bundle folding rollers 446a and 446b when folding the sheet bundle in half. When the sheet bundle is conveyed toward the leading end side of the branch path 440, the bundle folding rollers 446a and 446b are separated as indicated by broken lines. Further, the bundle folding roller driving mechanism 447 reverses the rotation direction of the bundle folding roller 446a in the forward direction rotating toward the nip with the bundle folding roller 446b and driving the sheet bundle toward the front end side of the branch path 440. Can be switched to rotation.

  The folding roller driving mechanism 447 also supports the bundle conveying rollers 443a and 443b so that they can be pressed and separated from the bundle folding rollers 446a and 446b, and conveys the sheet bundle toward the leading end side of the branch path 440. At this time, the bundle conveying rollers 443a and 443b are pressed against the bundle folding rollers 446a and 446b. On the other hand, when the sheet bundle is folded in two, the bundle conveying rollers 443a and 443b are separated from the bundle folding rollers 446a and 446b. Thus, the folded sheet bundle is pulled into the nip of the bundle folding rollers 446a and 446b without resistance.

  The branch path 440 is bent with a large radius along the external appearance of the housing structure 401 on the tip side of the bundle folding rollers 446a and 446b. The fold is started while being held in a substantially U-shaped curve along the branch path 440.

  The light shielding sensors 442a and 442b arranged on the branch path 440 are arranged at positions where the leading ends of the sheet bundles of the respective sheet sizes are detected in a state where the folding line of the sheet bundle is positioned at the nip of the bundle folding rollers 446a and 446b. Has been. The light shielding sensor 481 disposed on the upstream side of the stapler 480 is disposed at a position for detecting the rear end of the sheet bundle in a state where the end binding position of the sheet bundle is positioned at the staple binding position of the stapler 480.

  As shown in FIG. 3, the transport rollers 410a and 410b and the discharge roller 410c are supported by the transport roller support portions 413a and 413b and the discharge roller support portion 413c, respectively, and the transport roller separation drive portions (electromagnetic solenoids) 411a and 411b. When the discharge roller separation drive unit 411c is not driven, the discharge roller separation drive unit 411c is lifted away from the sheet by the conveyance roller separation springs 412a and 412b and the discharge roller separation spring 412c.

  When the conveyance roller separation drive units 411a and 411b and the discharge roller separation drive unit 411c are energized, the drive transmission support units 414a, 414b and 414c are centered on the fulcrum shafts 415a, 415b and 415c, and the conveyance roller separation springs 412a and 412b. Then, the discharge roller separation spring 412c is rotated in a direction to further extend. As a result, the engaging portions with the transport roller support portions 413a and 413b and the discharge roller support portion 413c are retracted, and the transport rollers 410a and 410b and the discharge roller 410c are dropped by their own weight.

  As shown in FIG. 4A, when the conveyance direction alignment reference drive unit (electromagnetic solenoid) 432 is operated, the conveyance direction alignment reference unit 430 closes the conveyance path 436 and abuts against the reversely fed sheet. Consistency.

  The conveyance direction alignment reference portion 430 can be moved to a rotation position corresponding to the sheet size together with the guide plate 433 by a conveyance direction alignment reference portion rotation mechanism 435 (FIG. 2). 4A is an alignment reference position when forming a large-size sheet bundle, and FIG. 4B is an alignment reference position of a small-size sheet.

  As shown in FIG. 5A, the conveyance direction alignment reference unit 430 is always pressurized in the direction in which the sheet is nipped by the conveyance direction alignment reference spring unit 431, and the conveyance direction alignment reference drive unit 432 operates. When not, the pressurized state is maintained between the guide plate 433, but when the conveyance direction alignment reference driving unit 432 is activated, the conveyance plate 433 rises through the thickness direction of the conveyance path 436 and aligns with the guide plate 433 in the conveyance direction. The sheet can be received at a distance from the reference unit 430.

<Control of sheet processing apparatus>
6 is a flowchart of control of the sheet processing apparatus, FIG. 7 is an explanatory diagram of operations of each unit from sheet reception to widthwise alignment, and FIG. 8 is an explanatory diagram of operations of each unit from sheet bundle formation to folding line positioning, FIG. 9 is an explanatory diagram of the operation of each part from folding in half to discharging the sheet bundle.

  As shown in FIG. 1, a control unit 600, which is a microcomputer control device mounted on the apparatus main body 500A of the copier 500, controls the printer unit 200 to form an image on the sheet, and controls the reader unit 120 to control the document. To read the image. When the sheet processing apparatus 400 is connected to the apparatus main body 500A, each part of the sheet processing apparatus 400 is controlled to perform a specified process.

  As shown in FIG. 2, the control unit 600 has written therein processing programs for image formation, document reading, and sheet processing and data necessary for program execution. However, detailed description will be given regarding image formation and document reading. Only the sheet processing will be described with reference to the flowchart of FIG.

  The control unit 600 reads and holds the written sheet processing program and various data, performs necessary data transmission and reception with an external device, reads various sensors and communication data according to the program, and executes necessary calculations. Then, the selected sheet processing is executed by operating various connected motors and actuators.

  As shown in FIG. 6 with reference to FIG. 2, when sheet processing is selected through an operation panel (not shown) and the start of image formation is instructed, the control unit 600 specifies sheet information such as the sheet size or the designated information. Processing information such as processing contents is acquired (S110), and it is determined whether or not bundle formation is included (S120).

  In the case of bookbinding processing and edge binding processing (YES in S120), the conveyance direction alignment reference portion rotation mechanism 435 is operated to position the conveyance direction alignment reference portion 430 at a rotation position corresponding to the sheet size (S130). Thereafter, image formation and sheet discharge are permitted (S140), and sheet reception is awaited (S150).

  The sheet S discharged from the apparatus main body 500A (FIG. 1) reaches the sheet processing apparatus 400 as shown in FIG. 7A (YES in S150). The conveyance rollers 410a and 410b are retracted in a direction away from the sheet S, and when the sheet S enters the sheet processing apparatus 400, the conveyance rollers 410a and 410b start to rotate in the forward direction and drop, as shown in FIG. The sheet S is nipped and conveyed downstream to the alignment unit 420 (S170).

  When the sheet S is conveyed to a predetermined position of the alignment unit 420, the conveyance direction alignment reference unit 430 is projected by the conveyance direction alignment reference driving unit 432 so as to block the conveyance path (S180), and the conveyance rollers 410a and 410b are Then, as shown in FIG. 7C, it stops and retracts in a direction away from the sheet S. Subsequently, the width direction aligning section 420 is reciprocated in the width direction by a driving mechanism (not shown) to perform width direction alignment (S190).

  When the alignment in the width direction is finished, as shown in FIG. 7B, the conveyance rollers 410a and 410b fall again and rotate in the reverse direction for a predetermined time, and the sheet S is abutted against the conveyance direction alignment reference portion 430. The conveyance direction is aligned (S200). At this time, the conveying force F applied to the sheet S by the conveying roller 410b is set to such an extent that the sheet S does not buckle, and after the sheet S is pressed against the conveying direction alignment reference portion 430, the conveying roller 410b moves on the surface of the sheet S. It slips and removes the skew of the sheet S.

  After the conveyance roller 410b is stopped, the conveyance direction alignment reference unit 430 is closed and the conveyance direction alignment reference side of the sheet S is sandwiched (S210), and the conveyance roller 410b is separated from the sheet S. The controller 600 determines whether or not a predetermined number of bundles have been formed (S220), and if not completed (NO in S220), the control in steps S140 to S220 is repeated.

  The conveyance path 436 and the conveyance direction alignment reference unit 430 are designed so that a space is formed in the conveyance path 436 even when about 10 to 20 sheets S are sandwiched, and the subsequent sheet S discharged from the apparatus main body 500A. Is conveyed on the sheet S sandwiched by the conveyance direction alignment reference unit 430 by the conveyance rollers 410a and 410b, and alignment and bundle formation are repeatedly performed, so that a conveyance path 436 including the conveyance direction alignment reference unit 430 is performed. Inside, as shown in FIG. 8A, a sheet bundle S1 is formed.

  When the accumulation of the predetermined number of sheets S is completed (YES in S220), it is determined whether or not the bookbinding process is performed (S230). If the bookbinding process is performed (YES in S230), the sheet bundle S1 is loaded by the conveyance direction alignment reference unit 430. By operating the stapler unit 480 while being held, the staple binding process is automatically executed on the fold line at the center of the sheet bundle (S240).

  Next, the conveyance rollers 410a and 410b drop to nip the sheet bundle S1, and the conveyance direction alignment reference unit 430 releases the nipping of the sheet bundle S1. Next, the transport rollers 410a and 410b rotate in the forward direction to exit the bundle transport path switching unit 441 and to turn on the light shielding sensor 481 as shown in FIG. 8B (end binding position by the stapler 480). The sheet bundle S1 is conveyed up to (S250).

  When the sheet bundle S1 stops at the above position, the bundle conveyance path switching unit 441 is deflected (S260), and the bundle folding rollers 446a and 446b are separated and start to rotate in the same direction. Thereafter, the conveying rollers 410a and 410b start to rotate in the reverse direction, and the sheet bundle that has been saddle-stitched enters the switched branch path 440 and is sent to the nip between the bundle folding roller 446b and the bundle conveying roller 443, and then continues. Then, the sheet is fed into the nip between the bundle folding roller 446a and the bundle conveying roller 443. Then, the conveyance of the sheet bundle is entrusted to the bundle folding rollers 446a and 446b, and the conveyance roller 410b is retracted upward.

  The sheet bundle conveyed by the bundle folding rollers 446a and 446b travels further along the branch path 440, and a position where the light shielding sensor 442a (442b) corresponding to the sheet size is turned on as shown in FIG. 8C. Then, the conveyance is stopped (S270).

  Next, as shown in FIG. 9A, the sheet bundle S1 is folded by pushing the folding line into the bundle folding rollers 446a and 446b by the pushing plate 445 (S280). At this time, the conveyance rollers 410a and 410b and the bundle conveyance roller 443 are separated from the sheet.

  However, the conveyance rollers 410a and 410b and the bundle conveyance roller 443 may be rotationally driven in a direction in which the sheet bundle S1 is pushed into the nip of the bundle folding rollers 446a and 446b. In this case, the rotational speed of the bundle folding rollers 446a and 446b is set to a value as low as the ejection speed of the abutting plate 445 so that the sheet folding is performed without the sheet bundle slipping too much with respect to the bundle folding rollers 446a and 446b. It may be.

  Next, as shown in FIG. 9B, the sheet bundle S1 bundle-folded by the bundle-folding rollers 446a and 446b is conveyed to the bundle conveying unit 450, and the bundle conveying unit 450 and the discharge rollers 410c and the discharge rollers are conveyed. The sheet is conveyed to the 410 g nip and discharged onto the stacking portion 470 by the discharge roller 410 c as shown in FIG. 9C (S 300).

  By the way, in the case of the end binding process (NO in step S230), as shown in FIG. 8B, the sheet bundle is conveyed to the end binding position by the stapler 480 and stopped (S320), and the stapler 480 is operated. Edge binding is performed (S330). As described above, the end binding position is the return position of the conveyance in the bookbinding process.

  If the bundle is not formed (NO in S120), the sheet discharge permission is issued (S310), the conveying rollers 410a and 410b and the discharge roller 410c are rotated in contact with each other, and discharged to the stacking unit 470 one by one. Simply load.

<Another embodiment>
FIG. 10 is an explanatory diagram of a configuration of an image forming apparatus according to another embodiment. In another embodiment, a sheet processing apparatus 1400 having the same operation and function as the sheet processing apparatus 400 described with reference to FIGS. 1 to 9 is disposed under the apparatus main body 1500A of the color printer 1500. 10, members having the same functions as those of the sheet processing apparatus 400 described with reference to FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 10, the apparatus main body 1500 </ b> A of the color printer 1500 includes a printer unit 1200 that can form a color image on sheets taken out from the sheet cassette 1204 (or 1205) one by one. In the printer unit 1200, four photosensitive drums 1202 corresponding to each color of cyan, magenta, yellow, and black are arranged in a line, and an exposure head and a developing unit (not shown) are respectively developed for the four photosensitive drums 1202. A container 1203 is arranged.

  In the color printer 1500 having such a configuration, when image data is formed by receiving document data from an external device such as a personal computer, the exposure head is operated based on the document data transmitted from the personal computer or the like, and the photosensitive drum 1202 is operated. A latent image is formed. The formed latent image is developed by the developing device 1203, whereby a toner image is formed on the photosensitive drum 1202.

  Cyan, magenta, yellow, and black toner images respectively formed on the four photosensitive drums 1202 using the exposure head and the developing device 1203 are successively transferred onto the surface of the sheet conveyed by the conveyance belt 1206. The fixing unit 1207 receives heat and pressure and is fixed to the sheet. The sheet on which the image has been formed proceeds from the discharge unit 1208 to the conveyance path switching unit 1510, guided downward by the conveyance path switching unit 1510, and enters the sheet processing apparatus 1400.

  The sheet processing apparatus 1400 is the same as the sheet processing apparatus shown in FIG. 1 except that the conveyance path 436 is formed upward in accordance with the sheet receiving direction and the conveyance direction alignment reference unit 430 is disposed on the apparatus main body 1500A side. 400 is configured in the same manner, and is controlled in the same manner, the same processing, that is, a simple stacking process in which image-formed sheets are discharged and stacked one by one on the stacking unit 470, and the image-formed sheets are stacked. It is possible to select and execute one of three processes: an end binding process in which a sheet bundle is formed and one end is stapled, and a bookbinding process in which the center of the formed sheet bundle is folded in half after the saddle stitching is performed. .

  When these processes are not performed, the conveyance path is switched by the conveyance path switching unit 1510, and the sheets on which images are formed are discharged one by one to the unprocessed sheet stacking unit 1530 via the unprocessed sheet discharge unit 1520 and stacked. Is done.

  Note that the color printer 1500 can be replaced with a model that supports double-sided printing, and after the images are formed on both sides of the sheet, the sheet processing apparatus 1400 can perform the bookbinding process.

  Furthermore, as in the image forming apparatus of the embodiment described with reference to FIGS. 1 to 9, an electrostatic printing type image forming apparatus is used as an example in another embodiment, but other image forming apparatuses such as ink The same applies to an image forming apparatus using an image forming apparatus and an inkjet image forming apparatus, and the image forming system is not limited.

<Another embodiment>
FIG. 11 is an explanatory diagram of a configuration of an image forming apparatus according to another embodiment. The sheet processing apparatus 400 according to the embodiment described with reference to FIGS. 1 to 9 can be configured with the color shown in FIG. 10 by making slight changes to the conveyance path 436, the conveyance direction alignment reference unit 430, the housing structure 401, and the like. In addition to the printer 1500, various mounting and connection forms are possible.

  As shown in FIG. 11A, the sheet processing apparatus 400 may be disposed above the apparatus main body 500A, and priority may be given to taking out the sheet bundle from the sheet processing apparatus 400.

  As shown in FIG. 11B, the overall height of the system may be lowered by arranging the sheet processing apparatus 400 so as to overlap the apparatus main body 500A.

  As shown in FIG. 11C, the sheet processing apparatus 400 may be placed between the reader unit 120 and the apparatus main body 500A without any gap, and priority may be given to downsizing of the entire apparatus.

  As shown in FIG. 11D, a large-size sheet stacking unit 570 is provided between the reader unit 120 and the apparatus main body 500A, and only the folded sheet bundle is stacked on the stacking unit 470. , Complete in-cylinder (complete in plane) discharge may be achieved.

<Effects of Sheet Processing Apparatus and Image Forming Apparatus of Embodiment>
As described above, the sheet processing apparatus 400 according to the present embodiment performs the stacking and alignment processing for bookbinding processing in the conveyance path 436, performs saddle stitching and folding in half, and then binds to the discharge path 451. The printed booklet is conveyed, discharged at least partially with the unprocessed sheet discharge roller 410c, and further used with at least part of the stacking unit 470, thereby forming a very compact bookbinding processing unit. Therefore, the layout flexibility of the sheet processing apparatus 400 can be improved with respect to the apparatus main body 500A, and the advantage of the apparatus main body 500A, for example, an image forming apparatus with excellent operability or a compact image can be obtained. An image forming apparatus system including a bookbinding processing unit can be provided without damaging the forming apparatus.

  In the copier 500 of this embodiment, the sheet processing apparatus 400 is arranged on the apparatus main body 500A. Therefore, like the color printer 1500 of another embodiment, the sheet processing apparatus 1400 is arranged below the apparatus main body 1500A. As a result, the booklet that has been bound is discharged to a higher position of the apparatus main body 500A, and the operability such as visibility and take-out of the booklet is improved.

The sheet processing apparatus 400 of the present embodiment is
(1) At least one sheet conveying unit that conveys the sheets for discharging and stacking, and a saddle stitch bookbinding unit that sequentially stacks and aligns the sheets for the saddle stitch bookbinding process and then folds them into a booklet. And the stacking process of the saddle stitching bookbinding process in the sheet conveyance unit,
(2) The booklet transport unit is a booklet transport unit that combines the sheet transport unit and the booklet transport unit, and at least a part of the sheet stacking unit and the booklet stacking unit. After that, it is joined again to the sheet conveyance unit and discharged to the sheet discharge unit and sheet stacking unit,
(3) By stacking large-sized sheets at the transport direction alignment position for saddle stitching, even a large-sized sheet is configured to fit within a substantially occupied area of the image forming apparatus,
(4) At the time of alignment in the conveyance direction, the conveyance direction alignment reference portion serving as the conveyance direction alignment reference, the conveyance portion of the aligned and saddle stitched sheet bundle, and at least a part of the conveyance direction alignment reference portion are used to Since it was configured to carry,
As described above, since the functions (1) to (4) are greatly combined, the number of components is reduced compared to a product in which each function is individually configured, and the mechanism and configuration. In addition, it is possible to provide a small and inexpensive product that can be easily installed even in a limited space such as an office desk or a general home. It has become possible.

  In addition, since the stacking unit can be arranged at a position where the finished booklet is most easily viewed and taken out by arranging in a vertical direction, it is possible to provide a user-friendly product.

  By the way, in recent years, a product has been proposed in which a sheet processing apparatus that performs edge binding and sorting processing and a small-size sheet stacking unit are accommodated within the floor area of the image forming apparatus. It goes out of the forming device. In addition, when a general user tries to create a booklet, the booklet that binds the edges can be substituted with a handy-type stepper that is available at general mass retailers, although it depends on the number of sheets to be bound. On the other hand, when trying to create a saddle-stitched booklet, a special needle-stitching device having a large span or a large-scale positioning device is required, and it is difficult to easily create a saddle-stitched booklet. Therefore, a product that can produce a saddle stitch booklet at low cost has been desired.

  The sheet processing apparatus 400 according to the present embodiment solves these problems and satisfies the market requirements as necessary. The purpose of the sheet processing apparatus 400 is to increase the number of bookbinding processes with the spread of color printing. An object of the present invention is to provide a small and inexpensive image forming apparatus and an image forming system including the image forming apparatus by disposing a possible sheet processing apparatus 400 in an occupied floor area of the image forming apparatus.

  That is, the sheet processing apparatus according to the present embodiment guides the sheet bundle folded in two by the bundle folding rollers 446a and 446b through the discharge path 451, and uses the same stacking unit from the same discharge roller 410c as in the case of simple stacking or edge binding processing. Since the sheet is discharged to 470, there is no need to separately provide a discharge roller dedicated to bookbinding and a stacking unit. In addition, a space lower than the nip of the discharge roller 410c is commonly used to efficiently stack a large amount of sheet bundles in both the end binding process and the bookbinding process, and a stacking space having a practical capacity in the cylinder is provided. A small sheet processing apparatus 400 with a reduced overall height and floor area can be realized while ensuring.

  In addition, the conveyance direction alignment reference unit 430 and the stapler 480 used in the end binding process are used as they are in the bookbinding process with only the positioning of the sheet bundle being changed. There is no need to provide.

  In addition, since the conveyance direction alignment reference unit 430 that is commonly used for the end binding process and the bookbinding process is arranged on the conveyance path 436 for conveying the sheet not to be bundled, the bundle formation is performed. Compared to the case where a separate bundle forming unit is provided for processing, or a bundle forming unit independent of a conveyance path for conveying a sheet that is not bundled is provided, the conveyance path and the bundle formation unit are simple and small. The required number of parts is also greatly reduced.

  Further, since the pushing plate 445 and the bundle folding rollers 446a and 446b are provided in the branch path 440, the pushing plate 445 and the bundle folding rollers 446a and 446b are placed at positions where the influence of members and mechanisms arranged on the transport paths 436 and 437 is avoided. The sheet bundle can be guided to a position that does not interfere with the members and mechanisms arranged in the conveyance paths 436 and 437 and can be folded in half.

  Further, since the sheet bundle is merged with the discharge roller 410c by the bundle conveyance unit 450 and the discharge path 451 arranged at positions away from the conveyance path 436, the floor area is increased by these newly added members, and the sheet bundle The transport distance does not increase.

  Further, since the folding is performed by the combination of the bundle folding rollers 446a and 446b and the veneer plate 445 supported by the history and results, the folding can be performed with high accuracy and high yield.

  Further, since the discharge side of the bundle folding rollers 446a and 446b is set to the discharge roller 410c side, the discharge path 451 can be shorter than the case of setting in another direction.

  Further, since the bundle folding rollers 446a and 446b are separable and reversible so that they also serve as a roller for conveying the sheet bundle along the branch path 440, a dedicated roller for conveyance is unnecessary.

  Further, since the branch path 440 is bent along the casing structure 401 at the point where the bundle folding rollers 446a and 446b are passed, the sheet processing apparatus 400 can be configured to be thinner than the case where the branch path 440 is not bent.

  Further, the nip of the discharge roller 410 is set at a high position, and a space area lower than the nip of the discharge roller 410 on the downstream side of the nip of the discharge roller 410 is allocated to the stacking unit 470 and is placed in the cylinder of the sheet processing apparatus 400. Since it is arranged, it is possible to secure a large and large stacking section 470 that is larger than the volume of the sheet processing apparatus 400, stack large sheets or a large number of sheet bundles, reduce the number of full loading, increase work efficiency, and copy machine The operating rate of 500 is also increased.

  Even if it is called in-cylinder discharge, the right side portion of the stacking unit 470 of the sheet processing apparatus 400 in FIG. 1 is opened, and the sheet cassette 204 is connected by connecting an attached fixed tray to the right side of the stacking unit 470. The same size sheets can be discharged and stacked. That is, a large size sheet can be stacked on the stacking unit 470 without performing the folding process. Then, a conveyance direction alignment reference unit 430 that is commonly used for the edge binding process and the bookbinding process is arranged on the conveyance path 436 for conveying the sheet that is not formed into a bundle, and the upstream side of the sheet that has been pulled back is sandwiched. Since the sheet bundle is formed, the sheet is buffered in the sheet conveyance path to form the sheet bundle. Therefore, it is not necessary to provide a sheet bundle forming space independent of the conveyance path such as the processing tray shown in Patent Document 2. Further, since the upstream end of the sheet is sandwiched by the sandwiching means to withstand the friction of the succeeding sheet, a considerable number of sheet bundles can be formed even in a narrow conveyance path.

  Further, since the conveyance direction alignment reference unit 430 is disposed on the conveyance path 436 where the staple binding position by the stapler 480 is positioned on the fold line of the sandwiched sheet bundle, the saddle stitching can be performed immediately after the bundle is formed. There is no worry that the transport and alignment will be disturbed. On the other hand, in the case of edge stitching, conveyance is performed up to the stapler 480. However, the poor accuracy of edge stitching is not as noticeable as in the case of saddle stitching, and thus does not pose a serious problem.

  Further, since the conveyance direction alignment reference portion 430 is positioned by the conveyance direction alignment reference portion rotating mechanism 435 at a position where the saddle stitching can be immediately performed according to the sheet size, the sheet bundle other than the A3 size is the same as the A3 size. Bookbinding is possible with accuracy and efficiency.

  Further, since the conveyance direction alignment reference portion 430 is rotated and positioned, it can be realized by a simple mechanism with a smaller floor area than that in the case of linear movement.

  Since the bundle folding rollers 446a and 446b and the pushing plate 445 are disposed on the branch path 440 branched from the transport path 436 toward the upstream side at a position between the transport direction alignment reference portion 430 and the stapler 480, the stapler The sheet bundle can be pulled back from the 480 side and folded in half, and the moving distance of the large sheet bundle before folding can be designed to be short (the interference area is narrow).

  In addition, since the branch path 440 is branched to the upstream side, when a part of the sheet bundle before the folding is left in the conveying path 437 and the folding is performed, the sheet bundle is pulled into the branch path 440 along with the folding. Resistance (bending, friction) is less than in the case of branching downstream.

  Further, since the radius that connects the conveyance path 437 and the branch path 440 can be set smaller than when branched to the downstream side, the bundle folding rollers 446a and 446b are positioned closer to the conveyance path 437 than when branched to the downstream side. The total length of the branch path 440 is shortened, and the amount of movement when positioning the sheet bundle on the bundle folding rollers 446a and 446b can be reduced.

  Since the bundle folding rollers 446a and 446b are arranged on the branch path 440 independent of the conveyance paths 436 and 437, the arrangement of the stapler 480, the conveyance rollers 410a and 410b and the like on the conveyance paths 436 and 437 is not affected. In addition, the spatial arrangement and performance of the bundle folding rollers 446a and 446b can be optimized, and the housing structure 401 can be designed with reduced overall height and floor area.

  Further, since the position where the saddle stitched sheet bundle is conveyed to the downstream side of the branch path 440 is the position where the stapler 480 binds the sheet bundle, the positioning stop control is executed by using one light shielding sensor 481 in common. it can.

  In addition, the sheet bundle folded in two by the bundle folding rollers 446a and 446b is guided by the discharge path 451 and discharged from the same discharge roller 410c to the same stacking unit 470 as in the case of simple stacking or edge binding processing. There is no need to provide a separate discharge roller and stacking unit. In addition, a space lower than the nip of the discharge roller 410c is commonly used to efficiently stack a large amount of sheet bundles in both the end binding process and the bookbinding process, and a stacking space having a practical capacity in the cylinder is provided. A small sheet processing apparatus 400 with a reduced overall height and floor area can be realized while ensuring.

  By providing such a sheet processing apparatus, an image forming apparatus capable of bookbinding processing can be designed to have a small floor area, a low overall height, a small number of parts, a lightweight design, a highly accurate bookbinding process, and a low cost. A highly reliable image forming apparatus can be provided.

  Further, since the sheet processing apparatus 400 is arranged so as to overlap the apparatus main body 500A and the reader unit 120, the image processing apparatus unnecessary for the sheet processing apparatus 400, the image forming apparatus unnecessary for the reader unit 120, and a special processing other than bookbinding processing. An image forming apparatus that performs processing can be easily realized by combining units of the same basic configuration, and mass production of each unit realizes cost reduction, high reliability, and refinement of design by shortening the new product launch span.

  Further, since the sheet processing apparatus 400 is controlled using the control unit 600 that controls the apparatus main body 500A, the number of necessary microcomputer control apparatuses is reduced by one, and a dedicated microcomputer control apparatus is provided in the sheet processing apparatus 400. The housing structure 401 can be downsized as compared with the case of providing the image forming apparatus, and the degree of freedom of arrangement of the internal devices is increased, and the space-efficient device arrangement is adopted, so that an image forming apparatus that is small but does not have difficulty in sheet conveyance or the like. realizable.

1 is a front view of a copying machine including a sheet processing apparatus according to an embodiment of the present invention. It is explanatory drawing of a structure of a sheet processing apparatus. It is a perspective view of the drive mechanism of a conveyance roller. It is explanatory drawing of positioning of a conveyance direction alignment reference | standard part. It is explanatory drawing of operation | movement of a conveyance direction alignment reference | standard part. 6 is a flowchart of control of the sheet processing apparatus. It is explanatory drawing of each part operation | movement from reception of a sheet | seat to alignment of the width direction. It is explanatory drawing of each part operation | movement from formation of a sheet bundle to positioning of a folding line. It is explanatory drawing of each part operation | movement from folding to sheet bundle discharge | emission. It is explanatory drawing of a structure of the image forming apparatus of another embodiment. It is explanatory drawing of the structure of the image forming apparatus of another embodiment.

Explanation of symbols

120 Reader unit 400 Sheet processing device 401 Housing structure 410a, 410b Conveying rollers 410c, 410g Discharging means (discharging roller, discharging roller)
420 Alignment part 430 Bundle formation means, clamping means (conveyance direction alignment reference part)
436 Conveyance path 440 Branch path 441 Conveyance direction switching unit 445, 446a, 446b Bi-folding means (abutting plate, bundle folding roller)
450, 451 Junction means (bundle transport unit, discharge path)
470 Sheet stacking means (stacking unit)
480 Needle binding means (stapler)
500 Image forming apparatus 500A Image forming means (apparatus body)
600 Control means (control unit)

Claims (14)

Sheet stacking means capable of stacking sheets and sheet bundles;
A transport path for transporting sheets stacked on the sheet stacking means;
A bundle forming unit arranged in the conveyance path and capable of forming a sheet bundle by superimposing sheets received in the conveyance path ;
A needle binding unit disposed in the transport path between the bundle forming unit and the sheet stacking unit and capable of staple binding one end in the transport direction of the sheet bundle formed by the bundle forming unit;
In a sheet processing apparatus comprising: a sheet transported through the transport path and a sheet bundle having the one end stapled by the needle binding unit and discharging the sheet bundle to the sheet stacking unit;
The needle binding means is capable of needle binding on a folding line when the sheet bundle formed by the bundle forming means is folded in two;
A branch path that can be received by branching from the conveyance path between the bundle forming means and the needle binding means, and feeding the sheet bundle that is saddle stitched on the fold line by the needle binding means to the upstream side. When,
Folding means for folding the sheet bundle received in the branch path into two at the fold line;
A sheet bundle discharged from the bi-folding means in a folded state is guided to the conveying path between the staple binding means and the discharging means, and is discharged from the bi-folding means in a folded state. Merging means for merging the sheet bundle with the discharging means;
Control means for controlling the bundle forming means, the staple binding means, and the discharge means to selectively execute stacking of sheets, end binding processing of the sheet bundle, and bookbinding processing; apparatus. The sheet processing apparatus according to claim 1 , wherein the control unit transports the sheet bundle, which is saddle-stitched by the staple binding unit, to the downstream side of the conveyance path and then reversely feeds the sheet bundle to the branch path . 3. The sheet processing apparatus according to claim 2 , wherein the position where the saddle-stitched sheet bundle is conveyed downstream of the conveyance path is a position where the staple-binding means end-stitches the edge-bound sheet bundle. . The bi-folding means has a bundle folding roller that is pressed against and rotated toward the discharge means, and a projecting member that is disposed to face the bundle folding roller and protrudes from the pressure contact line of the bundle folding roller,
The discharge path, the sheet processing apparatus according to any one of claims 1 to 3, characterized in that connected to the outlet side of the pressure-rotation of the bundle folding rollers. The sheet processing apparatus according to claim 4 , wherein the branch path is bent along an outline of a housing structure of the sheet processing apparatus at a point after passing the bundle folding roller . The bundle forming unit includes a clamping unit that sandwiches a plurality of sheets integrally by sequentially sandwiching upstream end portions of sheets that are reversely fed after being received from the upstream side into the conveyance path. The sheet processing apparatus according to any one of claims 1 to 5. The clamping means is an operation in which after the succeeding sheet passes through the surface of the sheet clamped by the clamping means, the clamping means is released and the succeeding sheet is fed back upstream to be clamped by the clamping means. The sheet processing apparatus according to claim 6 , wherein a sheet bundle is formed by repeating the steps. The clamping means, the sheet processing apparatus that claim 7, wherein the stapling position are determined position on the transport path so as to be positioned by said stapling means in a predetermined folding line sandwiching the sheet bundle . The clamping means is arranged to be movable along the transport path,
Prior to receiving the first sheet to be clamped , the control means sets the clamping means to a position corresponding to the sheet size so that the position of the sheet bundle after clamping is the saddle stitching position by the needle binding means. The saddle stitching process is performed on the folding line at the center of the sheet bundle by operating the needle binding means while the sheet bundle formed by the clamping means is held by the clamping means. The sheet processing apparatus according to claim 8. The clamping means is arranged at a portion of the conveyance path that is bent in an arc shape,
The sheet processing apparatus according to claim 9, further comprising a rotation mechanism that rotates the holding unit to move along the conveyance path. A housing structure in which the sheet stacking unit is disposed in the cylinder, and a space area downstream of the discharge unit and lower than the discharge unit in the housing structure is allocated to the sheet stacking unit; The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. Image forming means for forming an image on a sheet;
An image forming apparatus comprising: a processing unit that receives and processes a sheet on which an image is formed by the image forming unit;
An image forming apparatus characterized in that a sheet processing apparatus according to any one of the processing means according to claim 1 to 11. The image forming apparatus according to claim 12 , wherein the casing of the processing unit is placed in a plane of the casing of the image forming unit and is disposed so as to overlap the casing of the image forming unit. Wherein the controlling the image forming means microcomputer control unit for forming an image on a sheet, said processing means the image forming apparatus according to claim 12 or 13, wherein the processing of the sheet, characterized in that it is controlled by.

Images