JP2008184324A - Sheet folding device, post-processor provided with the same, and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet folding device, capable of inserting a sheet bundle between a pair of rolls to be folded by a folding blade, without causing position deviation, wrinkles, or breakage in the sheet bundle, so as to achieve excellent finish quality. <P>SOLUTION: A clutch means is provided to be releasably engaged with a roll drive means to make a first and a second folding rolls rotate to follow inserted sheets as the sheet bundle is inserted to a nip position between a pair of folding rolls by means of the folding blade. The sheet folding device is thus provided with a guide means to hold the sheet bundle to a prescribed folding position, the first and the second folding rolls in pressure-contact with each other, the folding blade to insert the sheet bundle supported by the guide means to the nip position of the first and the second folding rolls, a roll drive means to drive the first and the second folding rolls to rotate, a blade drive means to move the folding blade from a stand-by position to the nip position of the folding rolls, and a drive control means to control the roll drive means and the blade drive means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet folding apparatus that folds a sheet conveyed from an image forming apparatus such as a copying machine or a printer at a predetermined fold position, and a post-processing apparatus including the sheet folding apparatus. The present invention relates to an improvement of a folding mechanism.

  In general, an apparatus for folding a sheet (bundle) superposed on one sheet or a plurality of sheets along a predetermined fold line is widely known as a sheet folding apparatus. Such a folding apparatus is used as a single-function (stand-alone) apparatus, and is incorporated and used as a sheet folding unit in a post-processing apparatus of an image forming apparatus, for example. For example, it is used in an apparatus for bookbinding finishing by aligning and binding sheets formed by an image forming apparatus such as a copying machine in a bundle and binding the sheets.

Therefore, as a sheet folding mechanism that folds a sheet at a predetermined crease, a mechanism that folds a sheet by entering the sheet from a crease position between a pair of press-contacted rolls is widely adopted as a relatively simple structure. For example, in Patent Document 1, sheets from an image forming apparatus are aligned in a bundle, and a stapling unit is disposed on the alignment tray to bind the sheet center. A mechanism is disclosed in which the saddle stitched sheet bundle is inserted between a pair of rolls by a blade (folded plate) and folded at a fold position when the sheet bundle is fed out by the roll. Previously, there was a problem that the blade approach speed and the rotational peripheral speed of the roll were not considered in a special relation, so there was a problem that the sheet was broken. On the other hand, it has been proposed to set the rotational peripheral speed of the folding roll to be small (see paragraph [0047] of the same publication).
Japanese Patent Laying-Open No. 2001-2317 (FIG. 6)

  As described above, the following problem occurs when a bundle of sheets is caused to enter with a folding blade between a pair of rolls pressed against each other. First, as pointed out in the above-mentioned Patent Document 1, when the peripheral speed of the roll pair is faster than the moving speed of the folding blade, the outer sheet contacting the roll pair is sandwiched between the roll pair before the inner sheet contacting the folding blade. Sent. Therefore, when the sheet bundle is stapled, troubles such as wrinkles and breakage occur on the outer sheet. Even if the roll speed and the blade speed are the same, variations such as the pressure contact force between the rolls and the frictional force between the sheets occur, or the conveyance force of the roll pair and the conveyance force of the folding blade exerted on the sheet bundle due to external impacts, etc. May cause wrinkles and damage similar to those described above.

  Further, if the moving speed of the folding blade is set faster than the peripheral speed of the roll as in the above-mentioned patent document 1, a speed difference is generated between the sheet bundle inserted between the rolls by the folding blade, particularly between the outer sheet and the roll pair. Sliding occurs between the pair and the sheet surface. There is a possibility that the image ink printed by this sliding rubs and causes image blurring. In the case of the patent document 1, a problem that this image blur cannot be prevented newly occurs. In particular, for example, when an image or the like is applied to a cover sheet located outside the sheet bundle, this problem greatly affects the finishing quality.

  It is known that such problems at the time of sheet folding occur more frequently when the folding roll diameter is reduced to reduce the size of the apparatus, and when the number of sheet bundles increases, folding failures such as wrinkles and breakage occur frequently. . For example, when a large number of sheet bundles are folded between the rolls with a folding blade along a crease from a flat posture, the outer sheet (such as a cover sheet) that comes in contact with the roll pair first and away from the other sheets is first. Entrainment between rolls causes the above-mentioned problem.

  Accordingly, the present inventor has come to investigate that problems such as wrinkles, breakage, or image rubbing when the sheet bundle is folded are caused by a difference in speed between the folding roll and the folding blade, and at the same time folding the bundle sheet. The idea that the sheet follows the moving speed of the folding blade when it is inserted into the nip position of the roll, and after reaching the nip position, these problems can be solved by configuring the sheet to follow the peripheral speed of the roll pair. It came to.

Accordingly, the present invention mainly provides a sheet folding apparatus that has excellent finishing quality without causing misalignment, wrinkles, or damage to the sheet bundle when the sheet bundle is folded by a folding blade between a pair of rolls. It is a difficult issue.
Another object of the present invention is to provide a post-processing apparatus and an image forming system capable of stacking sheets sequentially delivered from the image forming apparatus in a bundle and folding them at a predetermined crease.

  In order to achieve the above object, according to the present invention, when a sheet bundle is inserted with a folding blade at the nip position of a pair of folding rolls that fold the sheet bundle, the first and second folding rolls rotate following the inserted sheet. As described above, it is characterized in that a detachable clutch means is provided between the roll drive means. Accordingly, the structure of the sheet folding apparatus includes: a guide unit that holds the sheet bundle at a predetermined folding position; first and second folding rolls that are disposed in the folding position and pressed against each other; and a sheet that is supported by the guide unit. Folding blade for inserting the bundle toward the nip position of the first and second folding rolls, roll driving means for rotating the first and second folding rolls, and the folding blade from the standby position to the folding Blade drive means that moves toward the nip position of the roll, roll drive means, and drive control means for controlling the blade drive means. The first and second folding rolls and the roll driving means are connected via a detachable clutch means, and the drive control means uses the folding blade to fold the sheet bundle with the first and second folding rolls. When inserting into the nip position of the roll, the clutch means is controlled so that the first and second folding rolls rotate following the insertion sheet.

  Further, the post-processing apparatus according to the present invention includes a sheet stacking unit that aligns the sequentially fed sheets into a bundle, a predetermined folding position set on or downstream of the sheet stacking unit, and the folding position. A sheet folding device for folding the sheet bundle accumulated by the sheet accumulation means. And this sheet folding apparatus is comprised by the above-mentioned structure.

  The image forming system according to the present invention includes an image forming apparatus that sequentially forms images on a sheet, and a post-processing apparatus that performs post-processing such as stapling, stamping, and punching on sheets from the image forming apparatus. Constitute. This post-processing apparatus is configured as described above.

  In the present invention, a detachable clutch means is provided between the first and second folding rolls pressed against each other and a driving means thereof, and when inserting a sheet bundle between the roll nips with a folding blade, the first and second folding rolls are provided. Since the second folding roll follows the sheet and is driven to rotate, when the sheet bundle is inserted into the nip position by the folding blade, the sheet is not caught in the roll that is driven and rotated. It is possible to enter the nip position at the correct crease position. Therefore, when the sheet bundle is inserted into the nip position with the folding blade, the sheet positioned on the folding roll side is not first wound, and a plurality of sheet bundles can be folded at the correct folding position.

  At the same time, the sheet bundle is folded between a pair of folding rolls that rotate according to the moving speed of the folding blade, so that the folding process is rich in finishing quality without causing any wrinkles or breakage, especially the staple-bound sheet bundle. Is possible.

  Further, when the sheet bundle is folded between the first and second folding rolls with the folding blade, the roll driving means stops the folding of the sheet bundle by stopping the folding roll driving means or rotating it at a speed slower than the folding blade speed. The present invention has a remarkable effect such that it can be reliably folded at the correct fold position without obstruction.

  The present invention will be described in detail below based on the preferred embodiments shown in the drawings. FIG. 1 shows the overall configuration of the image forming system according to the present invention, FIG. 2 is an explanatory diagram of the overall configuration of the post-processing apparatus, and FIGS. 3 and 4 are explanatory diagrams showing the detailed configuration of the sheet folding unit. Therefore, the image forming system shown in FIG. 1 includes an image forming apparatus A and a post-processing apparatus B. The post-processing apparatus B incorporates a sheet folding apparatus C as a unit. This will be sequentially described below.

[Configuration of Image Forming Apparatus]
The image forming apparatus A shown in FIG. 1 sends a sheet from the sheet feeding unit 1 to the image forming unit 2, prints the sheet on the image forming unit 2, and then carries the sheet out from the main body discharge port 3. The sheet feeding unit 1 stores sheets of a plurality of sizes in sheet feeding cassettes 1 a and 1 b, and separates designated sheets one by one and feeds them to the image forming unit 2. The image forming unit 2 includes, for example, an electrostatic drum 4, a print head (laser light emitting device) 5 and a developing device 6 arranged around the electrostatic drum 4, a transfer charger 7, and a fixing device 8. An electrostatic latent image is formed by the light emitting device 5, toner is adhered to the developing device 6, an image is transferred onto the sheet by the transfer charger 7, and heat fixing is performed by the fixing device 8. The sheets on which images are formed in this way are sequentially carried out from the main body discharge port 3. 9 is a circulation path, and the sheet printed on the front side from the fixing device 8 is turned upside down through the main body switchback path 10 and then fed again to the image forming unit 2 to print on the back side of the sheet. This is the path for duplex printing. The sheet printed on both sides in this way is turned upside down by the main body switchback path 10 and then carried out from the main body discharge port 3.

  11 is an image reading apparatus, which scans a document sheet set on a platen 12 with a scanning unit 13 and electrically reads it with a photoelectric conversion element (not shown). The image data is digitally processed by an image processing unit, for example, and then transferred to the data storage unit 14 to send an image signal to the laser emitter 5. 15 is a document feeder, which is a feeder device that feeds document sheets stored in the stacker 16 to the platen 12.

  The image forming apparatus A configured as described above is provided with a control unit (controller) shown in FIG. 9, and image forming conditions such as sheet size designation, color / monochrome printing designation, print number designation, single-sided / double-sided printing designation from the control panel 18. The printout conditions such as enlargement / reduction print designation are set. On the other hand, in the image forming apparatus A, image data read by the scan unit 13 or image data transferred from an external network is accumulated in the data storage unit 17, and the image data is transferred from the data storage unit 17 to the buffer memory 19. The data signal is sequentially transferred from the buffer memory 19 to the laser emitter 5.

  From the control panel 18, post-processing conditions are also input and specified simultaneously with the image forming conditions. As the post-processing conditions, for example, “print-out mode”, “staple binding mode”, “sheet bundle folding mode”, or the like is designated. The image forming apparatus A forms an image on the sheet according to the image forming condition and the post-processing condition. When “single-sided printing” is set as the image forming condition and “print-out mode” or “staple binding mode” is set as the post-processing condition, a predetermined image is formed on the sheet designated by the image forming unit 2, and this sheet Is reversed on the main body switchback path 10 and then carried out to the main body discharge port 3.

  The image forming mode will be described with reference to FIG. 5. In the image forming apparatus A, a series of sheets are sequentially formed on the first page to the nth page. A post-processing apparatus B, which will be described later, receives sheets carried out face down from the first page. When in the “print-out mode”, the sheets are sequentially stacked and stored in the first paper discharge tray 21 arranged in the post-processing apparatus B. In the “staple binding mode”, the sheets are stacked and stored in the second stacking unit 29 disposed in the post-processing apparatus B. Then, the sheets stacked on the paper discharge tray are bound together by an end face binding stapler 33 described later by a job end signal and stored in the first paper discharge tray 21.

  Also, when double-sided printing and 2-in-1 printing are specified in the image forming conditions and “sheet bundle folding mode” is set as post-processing, when the last page is n pages as shown in FIG. (N / 2) page image and (n / 2 + 1) page image on the front side of the sheet, and (n / 2-1) page image and (n / 2 + 2) page on the back side. Are formed and carried out from the main body discharge port 3. Then, the post-processing apparatus B described later stores the sheet in the first stacking unit 35 from the sheet carry-in path P1. Next, the image forming apparatus A prints the (n / 2-2) page image and the (n / 2 + 3) page image on the front side of the next sheet, and the (n / 2-3) page on the back side. And the (n / 2 + 4) th page image are printed out from the main body discharge port 3. Then, the post-processing apparatus B stacks and accumulates the sheets on the previous sheet. In this manner, the image forming apparatus A forms an image in an order suitable for the stacking tray structure of the post-processing apparatus B. Such a page order controls the print head (laser emitter) 5 by calculating the print order when transferring image data from the data storage unit 17 to the buffer memory 19.

[Configuration of post-processing equipment]
The post-processing apparatus B connected to the image forming apparatus A receives a sheet on which an image is formed from the main body discharge port 3 of the image forming apparatus A, and (1) stores the sheet in the first discharge tray 21. (The above-mentioned “print-out mode”) (2) The sheets from the main body discharge port 3 are aligned in a bundle and stapled, and then stored in the first discharge tray 21 (the above-mentioned “staple binding”). Mode ") (3) After the sheets from the main body discharge port 3 are aligned in a bundle, they are folded into a booklet and stored in the second discharge tray 22 (the above-mentioned" sheet bundle folding mode "). Has been.

  Therefore, as shown in FIG. 2, the post-processing apparatus B includes the first paper discharge tray 21 and the second paper discharge tray 22 in the casing 20, and a sheet carry-in path P <b> 1 having a carry-in port 23 connected to the main body discharge port 3. Is provided. The sheet carry-in path P <b> 1 is configured by a substantially horizontal straight path in the casing 20. A first switchback conveyance path SP1 and a second switchback conveyance path SP2 that branch from the sheet carry-in path P1 and transfer the sheet in the reverse direction are arranged. The first switchback transport path SP1 is branched from the sheet carry-in path P1 on the downstream side and the second switchback transport path SP2 is branched on the upstream side of the path, and the switchback transport paths SP1 and SP2 are spaced apart from each other. Has been placed.

  In such a path configuration, the carry-in roller 24 and the paper discharge roller 25 are arranged in the sheet carry-in path P1, and these rollers are connected to a drive motor (not shown) that can be rotated forward and backward. Further, a path switching piece 27 for guiding the sheet to the second switchback conveying path SP2 is disposed in the sheet carry-in path P1, and is connected to an operating means such as a solenoid. Further, a buffer guide 26 is provided in the sheet carry-in path P1 for temporarily staying and holding the sheet reaching the second switchback transport path SP2. A post-processing unit 28 is provided between the carry-in port 23 and the carry-in roller 24 to perform post-processing such as stamping (stamping means) and punching (punching means) on the sheet from the image forming apparatus A.

[Configuration of the first switchback transport path SP1]
As described above, the first switchback conveyance path SP1 disposed on the downstream side (rear end portion of the apparatus) of the sheet carry-in path P1 is configured as follows. A discharge roller 25 and a discharge port 25a are provided at the exit end of the sheet carry-in path P1, and a second stacking unit 29 is provided below the discharge port 25a with a step. The second stacking unit 29 includes a tray (hereinafter referred to as “stacking tray 29”) for stacking and supporting sheets from the sheet discharge outlet 25a. Above the stacking tray 29, a forward / reverse roller 30 is disposed so as to be movable up and down between a position in contact with the sheet on the tray and a separated standby position (a chain line position in FIG. 3). A forward / reverse motor M2 is connected to the forward / reverse roller 30 and rotates in the clockwise direction when the sheet enters the stacking tray 29, and rotates in the counterclockwise direction after the trailing edge of the sheet enters the tray. To be controlled. Accordingly, a first switchback transport path SP1 is formed on the stacking tray 29. 31 is a caterpillar belt, and the paper discharge roller 25 and one pulley side are pressed against each other, and the tip pulley side is pivotally supported so as to hang down on the stacking tray 29 around the pulley shaft 31a. A driven roller 30 b shown in the figure is engaged with the forward / reverse roller 30 and is provided on the stacking tray 29.

  With the above configuration, the sheet from the discharge port 25a enters the stacking tray 29 and is transferred toward the first discharge tray 21 by the forward / reverse rotation roller 30, and the rear end of the sheet is transferred from the discharge port 25a to the stacking tray 29. After entering, when the forward / reverse roller 30 is rotated backward (counterclockwise in the figure), the sheets on the stacking tray 29 are transferred in the direction opposite to the paper discharge direction. At this time, the caterpillar belt 31 switches back and conveys the sheet trailing edge along the stacking tray 29 in cooperation with the forward / reverse roller 30.

  A trailing edge regulating member 32 and a stapling device 33 for regulating the position of the trailing edge of the sheet are disposed at the trailing edge of the stacking tray 29 in the paper discharge direction. The illustrated stapling device 33 is composed of an end-face stitching stapler, and staples the staple at one place or a plurality of places on the trailing edge of the sheet bundle stacked on the stacking tray. Further, the trailing edge regulating member 32 reciprocates in the paper discharge direction along the stacking tray 29 in order to share the function of carrying out the staple-bound sheet bundle to the first paper discharge tray 21 disposed on the downstream side of the stacking tray 29. It is configured to move freely. The carry-out mechanism of the illustrated rear end regulating member 32 includes a grip claw 32a for holding the sheet bundle and a rear end regulating surface 32b for regulating the rear end of the sheet against the sheet bundle, and moves in the left-right direction along the guide rail provided on the apparatus frame. It is configured to be movable. Reference numeral 34a in the figure denotes a drive arm that reciprocates the rear end regulating member 32, and is connected to the paper discharge motor M3.

  The stacking tray 29 is provided with a side alignment plate 34b for aligning the width direction of the sheets stacked on the tray. The side alignment plate 34b is arranged on the left and right sides (around FIG. 3) so as to align the sheets with the center reference. It is composed of a pair of alignment plates, is configured to approach and separate from the center of the sheet, and is connected to an alignment motor (not shown).

  The first switchback transport path SP1 configured as described above aligns the sheets from the sheet discharge outlet 25a on the stacking tray 29 in the “staple binding mode”, and the sheet bundle is stapled (end-face binding stapler). ) In step 33, one or a plurality of places on the trailing edge are stapled. In the “print-out mode”, the sheet fed along the stacking tray 29 is conveyed between the forward / reverse roller 30 and the driven roller 30b without the switchback conveyance of the sheet from the sheet discharge port 25a. It is carried out to the paper tray 21. In this way, the illustrated apparatus is characterized in that the apparatus is compactly configured by supporting the sheets to be stapled by the stacking tray 29 and the first discharge tray 21 in a bridge manner.

[Configuration of second switchback transport path]
The configuration of the second switchback conveyance path SP2 branched from the sheet carry-in path P1 will be described. As shown in FIGS. 3 and 4, the second switchback transport path SP2 is disposed in a substantially vertical direction in the apparatus casing 20, and a transport roller 36 is disposed at the path entrance and a transport roller 37 is disposed at the path exit. Further, a first stacking unit 35 for aligning the sheets sent from the transport path is provided on the downstream side of the second switchback transport path SP2. The illustrated first stacking unit 35 includes a conveyance guide (stacking guide unit) for transferring sheets (hereinafter referred to as “stacking guide 35”). The accumulation guide 35 is provided with a saddle stitching staple device 40 and a folding roll means 45. Hereinafter, these configurations will be sequentially described.

  First, the accumulation guide 35 is formed by a guide member that guides conveyance of the sheet, and is configured to stack and store the sheet on the guide. The illustrated accumulation guide 35 is connected to the second switchback conveyance path SP <b> 2 and is disposed substantially vertically in the center of the apparatus casing 20. As a result, the apparatus is made compact and compact. The accumulation guide 35 is formed in a length shape that accommodates the maximum size sheet therein, and in particular, the illustrated guide is bent or bent so as to protrude to the side where the saddle stitching staple device 40 and the folding roll means 45 described later are disposed. It is configured in shape.

  A switchback entry path 35a that overlaps with the outlet end of the second switchback transport path SP2 is connected to the rear end side of the stacking guide 35 in the transport direction. This stacks by overlapping the leading edge of the loaded (following) sheet sent from the conveying roller 37 of the second switchback conveying path SP2 and the trailing edge of the stacked (preceding) sheet supported by the stacking guide 35. This is for securing the page order of sheets. Further, a leading edge regulating member 38 for regulating the leading edge of the sheet is disposed on the downstream side of the accumulation guide 35. The leading edge regulating member 38 is supported by a guide rail or the like so as to be movable along the accumulation guide 35, and shift means ( (Not shown) is configured to move between positions Sh1, Sh2, and Sh3.

  When the leading end regulating member 38 is positioned at the illustrated position Sh3, the rear end of the sheet (bundle) supported by the stacking guide 35 enters the switchback entry path 35a and is sent from the second switchback conveyance path SP2 in this state. Subsequent sheets will surely be stacked above the stacked sheets. When the leading end regulating member 38 is positioned at the illustrated position Sh2, the center of the sheet (bundle) supported by the stacking guide 35 is positioned at the binding position X of the saddle stitching staple device 40 described later. Similarly, when the leading end regulating member 38 is positioned at the illustrated position Sh1, staple binding is performed, and the center of the sheet bundle supported by the stacking guide 35 is positioned at a folding position Y of a folding roll means described later. Accordingly, the illustrated positions Sh1, Sh2, and Sh3 are set to optimum positions according to the sheet size (length in the conveyance direction).

  A sheet side edge aligning member 39 is disposed on the accumulation guide 35 on the downstream side in the sheet conveying direction. The sheet side edge aligning member 39 aligns so that the position in the width direction of the sheet carried into the stacking guide 35 and supported by the leading end regulating member 38 is matched with the reference. In other words, the sheet side edge adjusting member 39 performs the width-alignment alignment in a state where the sheet leading edge regulating member 38 is positioned at the position of Sh3 and the entire sheet is supported by the accumulation guide 35. In the illustrated apparatus, the sheet side edge aligning member 39 is composed of a pair of left and right aligning plates so that the sheets are aligned and aligned with respect to the center, and the pair of aligning plates are supported by the guide by being equidistant from the sheet center. The aligned sheet bundle is aligned and aligned. For this reason, the sheet side edge alignment member 39 is connected to an alignment motor (not shown).

[Configuration of Saddle Stitcher]
A binding position X is set on the upstream side and a folding position Y is set on the downstream side along the above-described accumulation guide 35, and the saddle stitching staple device 40 is disposed in the binding position X. The stapling apparatus includes a driver unit 40A and an anvil unit 40B, and each unit is configured to be separated at opposing positions with the accumulation guide 35 interposed therebetween. A needle cartridge is mounted on the driver unit 40A, and a needle connected in a belt shape is built in the cartridge. The needle member at the tip is bent into a U shape by the former member by a driver member that moves up and down between the upper dead center and the lower bottom dead center, and then this needle is inserted into the sheet bundle. Has been. Accordingly, the driver unit 40A includes a drive motor M, a drive arm that moves the driver unit up and down, a drive cam that drives the arm, and the like.

  On the other hand, the anvil unit 40B is provided with a bending groove (not shown) for bending the tip of the staple needle inserted into the sheet bundle. The saddle stitching and stapling apparatus 40 configured as described above is configured such that the driver unit 40A and the anvil unit 40B are separated from each other so that a sheet bundle can pass between them. Accordingly, it is possible to staple the central portion of the sheet bundle and other arbitrary positions.

[Configuration of folding roll means]
At the folding position Y arranged on the downstream side of the saddle stitching stapler 40, the folding roll means 45 for folding the sheet bundle and the sheet bundle at the nip position NP of the folding roll means 45 (see FIG. 6A). A folding blade 46 for insertion is provided. As shown in FIGS. 6 (a) and 6 (b), the folding roll means 45 is composed of rolls 45a and 45b that are in pressure contact with each other, and each roll is formed to have a substantially maximum sheet width. The pair of rolls 45a and 45b are fitted in the long grooves of the apparatus frame so that the rotary shafts 45ax and 45bx are pressed against each other, and are urged in the press-contact direction by the compression springs 45aS and 45bS. The rolls 45a and 45b may be structured such that at least one of them is supported by a shaft so as to be movable in the press-contact direction, and an urging spring is stretched over one of the rolls.

  The pair of rolls 45a and 45b are formed of a material having a relatively large friction coefficient such as a rubber roller. This is because the sheet is bent and transferred by a soft material such as rubber, and may be formed by lining the rubber material. The folding roll means 45 is formed in an uneven shape as shown in FIG. 6B, and a gap 45g is formed in the sheet value width direction. The gap 45g is arranged so as to coincide with the unevenness of the folding blade 46, which will be described later, and consideration is given so that the tip of the folding blade can easily enter between the roll nips. At the same time, the gap 45g is arranged at a width position that coincides with a staple binding portion for binding the sheet bundle. In other words, the pair of rolls 45a and 45b that are pressed against each other are formed in a concavo-convex shape having a gap (gap 45g) in the sheet width direction, and the staple binding portion of the sheet and the folding blade 46 similarly formed in the concavo-convex shape in this gap. The cutting edge enters.

  Each of the rolls 45a and 45b is connected to a roll driving means RM. The illustrated roll drive means RM is composed of a roll drive motor M6 and a transmission mechanism (transmission means) 47V as shown in FIG. The illustrated transmission means 47V is composed of a transmission belt that decelerates the rotation of the roll drive motor M6 and transmits it to the transmission shaft 47X. Clutch means 45c is disposed between the transmission shaft 47X and the rotation shaft 45ax of the first folding roll 45a. Similarly, a clutch means 45c is also arranged between the second folding roll 45b and the rotation shaft 45bx. This clutch means 45c is an electromagnetic clutch, a one-way clutch (one-way clutch), a sliding friction clutch (spring clutch), etc., and the drive rotation of the roll drive motor M6 is turned on and off to the first folding roll 45a and the second folding roll 45b. Configure as you can.

  The illustrated clutch means 45c is constituted by a one-way clutch, and is configured to transmit the rotation of the transmission shaft 47X to the transmission collar 47Z only in one direction between the transmission shaft 47X and the transmission collar 47Z. The first folding roll 45a is gear-connected to the transmission collar 47Z, and the second folding roll 45b is belt-connected. Thus, only one direction of rotation of the roll drive motor M6 is transmitted to the first and second folding rolls 45a and 45b connected to the roll drive motor M6 via the clutch means 45c, and at the same time, the roll is in the sheet feeding direction. It is configured to be freely rotatable.

  The pair of rolls 45a and 45b are positioned on the curved or bent protruding side of the stacking guide 35, and are separated from the sheet bundle supported by the stacking guide 35 by a distance h shown in FIG. Has been placed. That is, the sheet (bundle) supported by the accumulation guide 35 is disposed at a position where the roll surface does not come in contact with the distance h. And the folding blade 46 which has a knife edge is provided in the position which opposes on both sides of a sheet | seat bundle. The folding blade 46 is supported by the apparatus frame so as to be able to reciprocate between the standby position in FIG. 8A and the nip position in FIG. Blade driving means BM is connected to the folding blade 46. The folding blade 46 is configured to reciprocate between a standby position retracted from the sheet bundle supported by the stacking guide 35 and a nip position between the pressure contacts of the folding roll means 45 by a drive motor. The folding blade 46 is formed in a plate shape with a material having a relatively small coefficient of friction such as metal, and its tip is formed in an uneven surface as shown in FIG. The blade tip is formed in a shape that enters the cap 45g of the folding roll means 45 as described above.

  Therefore, in the illustrated example, the relationship between the friction coefficient ν1 between the pair of rolls 45a and 45b and the sheet, the friction coefficient ν2 between the sheets, and the friction coefficient ν3 between the sheet and the folding blade 46 is “ν1> ν2>. The relationship of “ν3” is set. Accordingly, in the state where the sheet bundle shown in FIG. 8C is inserted between the first folding roll 45a and the second folding roll 45b by the folding blade 46, the pressure contact force acting on both the rolls 45a and 45b becomes the roll pair. It reaches each as equal force on the sheet bundle and folding blade. At this time, since the friction coefficient is set to the above relationship, the sheet bundle is smoothly fed in the feeding direction (left side in the figure).

  Next, the configuration of the blade driving means BM of the folding blade 46 will be described. As shown in FIG. 7B, the folding blade 46 is supported on the apparatus frame by a guide rail 46g so as to be movable in the sheet folding direction. The folding blade 46 is supported so as to be able to reciprocate between a standby position retracted from the sheet supported by the accumulation guide 35 and a nip position NP of the folding roll means 45. The blade drive means BM for reciprocating the folding blade 46 is a blade drive motor M7 and a transmission means 46V for transmitting the rotation thereof, and the illustrated one is transmitted to the transmission rotation shaft 46X by a transmission belt. The transmission rotation shaft 46X is provided with a transmission pinion 46P and meshed with a rack gear 46L attached integrally to the folding blade 46.

  Accordingly, when the blade drive motor M7 rotates forward and backward, the folding blade 46 reciprocates between the standby position and the nip position NP along the guide rail 46g. The folding blade 46 is composed of a plate-like member having a knife edge in the sheet width direction, and its tip is formed in an uneven shape as shown in the figure.

  Next, the sheet folding state by the folding roll means 45 and the folding blade 46 having the above configuration will be described with reference to FIGS. First, the sheet bundle supported by the stacking guide 35 in the form of a bundle is locked to the leading end regulating member 38 in the state shown in FIG. 5A, and the fold position is positioned at the folding position Y in the stapled state. Upon obtaining this sheet bundle setting end signal, the drive control means (sheet folding operation control section, which will be described later) 64d turns off the clutch means 45c. In the illustrated one-way clutch configuration, the roll drive motor M6 is stopped, or the drive motor M6 is rotated at a lower speed than the moving speed of the folding blade 46. This is to create a condition for the first and second folding rolls 45a and 45b to be driven and rotated by the sheet bundle inserted at the nip position NP by the folding blade 46, as will be described later.

  Accordingly, the drive control means 64d moves the folding blade 46 from the standby position toward the nip position NP at a predetermined speed. The rotational peripheral speed VR of the folding roll means 45 is set to zero or VB> VR with respect to the moving speed VB (see FIG. 6A). Therefore, in the state of FIG. 8B, the sheet bundle is bent at the fold position by the folding blade 46 and inserted between the rolls. At this time, the first and second folding rolls 45 a and 45 b are driven and rotated continuously with the sheet moved by the folding blade 46. The drive control means 64d stops the blade drive motor M7 after the expected time for the sheet bundle to reach the predetermined nip position, and stops the folding blade 46 at the position shown in FIG. Before and after this, the drive control means 64d switches the clutch means 45c to the ON state to drive and rotate the first and second folding rolls 45a and 45b. Then, the sheet bundle is sent out in the feeding direction (left side in the figure). Thereafter, the drive control means 64d moves and returns the folding blade 46 located at the nip position toward the standby position in parallel with the feeding of the sheet bundle by the folding roll means 45 in the state shown in FIG.

  When the sheet bundle thus folded is first engulfed between the pair of folding rolls 45a and 45b, the sheet in contact with the roll surface is not drawn between the rolls by the rotating roll. That is, since the folding roll means 45 follows (follows) the sheet to be inserted (pushed) and rotates, only the sheet in contact with the roll will not be wound first. Further, since the folding roll means 45 follows and rotates following the inserted sheet, the roll surface and the sheet in contact therewith are not rubbed, and image rubbing is not caused.

[Description of control configuration]
The control configuration of the above-described image forming system will be described with reference to the block diagram of FIG. The image forming system shown in FIG. 1 includes a control unit (hereinafter referred to as “main body control unit”) 50 of the image forming apparatus A and a control unit (hereinafter referred to as “post-processing control unit”) 60 of the post-processing apparatus B. The main body control unit 50 includes an image formation control unit 51, a paper feed control unit 52, and an input unit 53. Then, the “image forming mode” and “post-processing mode” are set from the control panel 18 provided in the input unit 53. As described above, the image forming mode sets the number of printouts, sheet size, color / monochrome printing, enlargement / reduction printing, duplex / single-sided printing, and other image formation conditions. Then, the main body control unit 50 controls the image forming control unit 51 and the paper feed control unit 52 according to the set image forming conditions to form an image on a predetermined sheet, and then sequentially carry out the sheets from the main body discharge port 3. To do.

  At the same time, the post-processing mode is set by input from the control panel 18. The post-processing mode is set to, for example, “print-out mode”, “staple binding finishing mode”, “sheet bundle folding finishing mode”, or the like. Therefore, the main body control unit 50 transfers the finishing mode of the post-processing, the number of sheets, the number of copies information, and the binding mode (one-position binding or two or more bindings) information to the post-processing control unit 60. At the same time, the main body control unit 50 transfers a job end signal to the post-processing control unit 60 every time image formation is completed.

  The post-processing control unit 60 includes a control CPU 61 that operates the post-processing apparatus B in accordance with a designated finishing mode, a ROM 62 that stores an operation program, and a RAM 63 that stores control data. The control CPU 61 includes a sheet conveyance control unit 64a that performs conveyance of the sheet sent to the carry-in entrance 23, a sheet accumulation operation control unit 64b that performs sheet accumulation operation, and a sheet binding operation that performs sheet binding processing. A control unit 64c and a sheet folding operation control unit (drive control unit) 64d that executes a sheet folding operation are provided.

  The sheet conveyance control unit 64a is connected to the control circuit of the driving motor M1 of the conveyance roller 24 and the discharge roller 25 in the sheet conveyance path P, and receives a detection signal from a sheet sensor arranged in this path. It is configured. The sheet stacking operation control unit 64b drives the forward / reverse rotation motor M2 of the forward / reverse rotation roller 30 and the discharge motor M3 of the trailing end regulating member 32 in order to stack sheets on the second stacking unit (stacking tray) 29. Connected to the circuit. Further, the sheet binding operation control unit 64c is connected to a drive circuit of a drive motor built in the end stitching stapling device 33 of the second stacking unit 29 and the saddle stitching stapling device 40 of the first stacking unit (stacking guide) 35. Yes.

  The sheet folding operation control unit 64d is connected to a drive circuit of a roll drive motor M6 that drives and rotates the first and second folding rolls 45a and 45b and a drive circuit of the clutch means 45c. Further, the sheet folding operation control unit 64d is connected to a control circuit of a shift unit that controls the movement of the conveying rollers 36 and 37 of the second switchback conveying path SP2 and the leading end regulating unit 38 of the stacking guide 35 to predetermined positions. Are connected so as to receive a detection signal from a sheet sensor arranged in the path.

The control unit configured as described above causes the post-processing apparatus B to execute the next processing operation.
"Printout mode"
In this mode, the image forming apparatus A forms an image of a series of documents, for example, from the first page, and sequentially carries out face-down from the main body discharge port 3. Therefore, the post-processing apparatus B retracts the buffer guide 26 in the sheet carry-in path P1 upward in FIG. 3, and moves the path switching piece 27 to the state of the solid line in FIG. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 25. Therefore, after the expected time that the leading edge of the sheet reaches the forward / reverse roller 30 of the stacking tray 29 based on the signal detected by the sheet discharge port 25a, the sheet conveyance control unit 64a moves the forward / reverse roller 30 from the upper standby position onto the tray. Then, the forward / reverse roller 30 is rotated clockwise in FIG. Then, the sheet that has entered the stacking tray 29 is carried out toward the first paper discharge tray 21 by the forward / reverse rotation roller 30 and stored on the tray. The successive sheets are sequentially carried out to the first paper discharge tray 21 and accumulated and stored on the tray.

  Accordingly, in this printout mode, the sheets on which the image is formed by the image forming apparatus A are accommodated in the first paper discharge tray 21 via the sheet carry-in path P1 of the post-processing apparatus B. The pages are stacked and stored in the order of the pages. In this mode, no sheet is guided to the first switchback conveyance path SP1 and the second switchback conveyance path SP2.

"Staple binding finish mode"
In this mode, the image forming apparatus A forms an image of a series of documents from the first page to the nth page in the same manner as in the above-described mode, and carries it out from the main body discharge port 3 in a face-down state. Accordingly, the post-processing apparatus B retracts the buffer guide 26 of the sheet carry-in path P1 upward in FIG. 3 and moves the path switching piece 27 to the state of the solid line in FIG. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 25. Therefore, after the expected time that the leading edge of the sheet reaches the forward / reverse roller 30 of the stacking tray 29 based on the signal detected by the sheet discharge port 25a, the sheet conveyance control unit 64a moves the forward / reverse roller 30 from the upper standby position onto the tray. Then, the forward / reverse roller 30 is rotated clockwise in FIG. Next, the sheet conveyance control unit 64a drives the forward / reverse rotation roller 30 to rotate counterclockwise in FIG. 3 after the estimated time when the trailing edge of the sheet is carried onto the stacking tray 29. Then, the sheet that has entered from the paper discharge outlet 25a is switched back and conveyed onto the stacking tray 29 along the first switchback conveyance path SP1. By repeating this sheet conveyance, a series of sheets are stacked on the stacking tray 29 in a face-down state.

  Each time the sheets are stacked on the stacking tray 29, the control CPU 61 operates the side aligning plate 34b to align the width direction positions of the sheets to be stacked. Next, the control CPU 61 operates the end-face stitching and stapling device 33 in response to the job end signal from the image forming apparatus A to bind the trailing edge of the sheet bundle stacked on the stacking tray 29. After this stapling operation, the control CPU 61 moves the rear end regulating member 32 that also serves as a bundle carrying-out means from the solid line position in FIG. 3 to the chain line position. Then, the staple-bound sheet bundle is carried out and stored in the first discharge tray 21. As a result, a series of sheets formed by the image forming apparatus A are stapled and stored in the first paper discharge tray 21.

"Sheet fold finish mode"
In this mode, the image forming apparatus A forms an image on a sheet in the order described with reference to FIG. Therefore, the post-processing apparatus B retracts the buffer guide 26 of the sheet carry-in path P1 upward in FIG. 3, and moves the path switching piece 27 to the state of the solid line in FIG. As a result, the sheet sent to the sheet carry-in path P <b> 1 is guided to the paper discharge roller 25. Therefore, the control CPU 61 stops the paper discharge roller 25 at the timing when the trailing edge of the sheet passes the path switching piece 27 with reference to the signal detected by the sheet sensor S1, and at the same time, sets the path switching piece 27 to the position of the broken line in FIG. Moving. Then, the paper discharge roller 25 is reversely rotated (counterclockwise in FIG. 3). Then, the sheet that has entered the sheet carry-in path P1 is reversed in the conveyance direction, and is guided from the path switching piece 27 to the second switchback conveyance path SP2. Then, it is guided to the accumulation guide 35 by the conveyance rollers 36 and 37 arranged in this conveyance path.

  At the timing when the sheet is carried into the stacking guide 35 from the second switchback conveyance path SP2, the control CPU 61 moves the leading end regulating member 38 to the lowermost Sh1 position. Then, the entire sheet is supported by the accumulation guide 35. In this state, the control CPU 61 operates the above-mentioned sheet side edge aligning member 39 to align the sheets by width alignment. (Note that this width-alignment alignment does not have to be performed on the first sheet, and does not have to be performed every time the sheet enters). Next, the control CPU 61 moves the front end regulating member 38 to a position Sh3 where the rear end of the sheet enters the switchback entry path 35a. Then, the rear end of the sheet supported by the accumulation guide 35 moves backward to the switchback entry path 35a. In this state, subsequent sheets are sent from the second switchback conveyance path SP2 onto the accumulation guide 35, and the subsequent sheets are stacked on the preceding sheet. Then, the leading edge regulating member 38 is moved from the Sh3 position to the Sh1 position in accordance with the carry-in of the subsequent sheet.

  Next, the sheet side edge aligning member 39 is operated in the same manner as described above, and the loaded sheet and the sheet supported on the stacking guide 35 are aligned and aligned. By repeating such an operation, the sheet on which the image is formed by the image forming apparatus A is aligned on the stacking guide 35 via the second switchback conveyance path SP2. Therefore, when receiving the job end signal, the control CPU 61 moves the leading edge regulating member 38 to the position Sh2, and sets the center of the sheet to the binding position X.

  Therefore, the control CPU 61 operates the saddle stitching stapling device 40 to staple one or more places in the center of the sheet. In response to this operation completion signal, the control CPU 61 moves the leading end regulating member 38 to the position Sh1, and positions and sets the center of the sheet at the folding position Y. Therefore, the sheet bundle is folded in the sequence shown in FIGS. 8A to 8D and the sheet bundle is carried out to the second paper discharge tray 22.

  In the present invention, the saddle stitching stapling device 40 is disposed at the binding position X on the stacking guide 35 described above. However, the sheet processing path is disposed in the order of the stacking guide, the binding position, and the folding position. The stacking guide unit, then the stapling device, and the sheet folding unit may be arranged downstream thereof. Further, it is possible to fold the sheet bundle and carry it out to the second paper discharge tray 22 without performing the binding process by the saddle stitching stapling device 40.

1 is an overall explanatory diagram of an image forming system according to the present invention. 1 is an overall explanatory view of a post-processing apparatus provided with a sheet folding apparatus according to the present invention. Detailed explanatory drawing which shows a part of post-processing apparatus of FIG. FIG. 3 is a detailed explanatory diagram of a sheet folding apparatus incorporated in the post-processing apparatus of FIG. 2. FIG. 2 is an explanatory diagram showing an image forming order in the apparatus of FIG. 1. It is explanatory drawing of the folding roll means of FIG. 4, (a) is sectional structure, (b) is explanatory drawing of a sheet | seat width direction plane. (A) is explanatory drawing of the drive mechanism of folding roll means, (b) is explanatory drawing of the drive mechanism of folding blade, (c) is structure explanatory drawing of a one-way clutch. FIGS. 3A and 3B are explanatory diagrams of a sheet bundle folding operation in the apparatus of FIG. 2, wherein FIG. 3A is a state diagram in which the sheet bundle is positioned and set at a folding position, FIG. 2B is an initial state diagram of the sheet bundle folding operation; Is a state diagram in which the sheet bundle is inserted into the nip position of the folding roll means, and (d) is a carrying out state diagram in which the sheet bundle is folded by the folding roll means. Explanatory drawing of the control structure in the system of FIG.

Explanation of symbols

A image forming apparatus B post-processing apparatus P1 sheet carry-in path SP1 first switchback conveyance path SP2 second switchback conveyance path 21 first paper discharge tray 22 second paper discharge tray 23 carry-in port 24 carry-in roller 25 paper discharge roller 25a discharge Paper mouth 26 Buffer guide 27 Path switching piece 28 Post-processing unit 29 Second stacking unit (stacking tray)
30 Forward / Reverse Roller 31 Caterpillar Belt 32 Rear End Restricting Member 33 Staple Device 34 Side Alignment Plate 35 First Stacking Unit (Stacking Guide)
36 transport roller 37 transport roller 38 leading edge regulating member 40 saddle stitching staple device 45 folding roll means 45a first folding roll 45ax rotating shaft 45b second folding roll 45bx rotating shaft 45g gap 45c clutch means 46 folding blade 64d drive control means RM Roll drive means BM Blade drive means X Binding position Y Folding position

Claims (9)

Guide means for holding the sheet bundle in a predetermined folding position;
First and second folding rolls arranged in the folding position and in pressure contact with each other;
A folding blade for inserting the sheet bundle supported by the guide means toward the nip position of the first and second folding rolls;
Roll driving means for rotationally driving the first and second folding rolls;
Blade driving means for moving the folding blade from the standby position toward the nip position of the folding roll;
A drive control means for controlling the roll drive means and the blade drive means,
The first and second folding rolls and the roll driving means are coupled via a detachable clutch means,
The drive control means is configured so that when the sheet bundle is inserted into the nip position of the first and second folding rolls by the folding blade, the first and second folding rolls are rotated by following the inserted sheet. A sheet folding apparatus for controlling the clutch means. The drive control means rotates the first and second folding rolls following the sheet entering with the folding blade, and then the first and second folding rolls with the folding blade stationary at the nip position. 2. The sheet folding apparatus according to claim 1, wherein the clutch means is controlled to drive and rotate the roll in the folding direction. The first and second folding rolls are pressed against each other at a predetermined pressure, and the friction coefficient between the first and second folding rolls and the sheet is larger than the coefficient of friction between the sheets,
The sheet folding apparatus according to claim 1, wherein a friction coefficient between the folding blade and the sheet is configured to be smaller than a friction coefficient between the sheets. The roll drive means includes a drive motor and a one-way rotary clutch that transmits the rotational force of the drive motor to the first and second folding rolls.
4. The sheet folding apparatus according to claim 1, wherein the drive control unit stops the drive motor when the folding blade is moved from a standby position to a nip position. 5. The roll drive means is composed of a roll drive motor and a transmission means having a one-way rotation clutch that transmits the rotational force of the roll drive motor to the first and second folding rolls.
The blade drive means is composed of a blade drive motor and a transmission means for converting the rotational force of the blade drive motor into a reciprocating linear motion and transmitting it to the folding blade.
When the drive control means moves the folding blade from the standby position to the nip position,
Controlling the roll drive motor and the blade drive motor so that the rotation of the roll drive motor is rotated at a peripheral speed slower than the moving speed of the folding blade, the first and second folding rolls;
(1) The first and second folding rolls are rotated by the sheet bundle moved by the folding blades according to the speed difference between the moving speed of the folding blades and the peripheral speed of the folding rolls,
(2) The sheet folding apparatus according to any one of claims 1 to 4, wherein the sheet folding device is controlled such that the folding blade is stationary and the sheet bundle is conveyed in the folding direction by rotation of the folding roll. . A post-processing apparatus that performs post-processing by aligning sheets carried out from an image forming apparatus,
Sheet stacking means for aligning sequentially fed sheets in a bundle, and
A predetermined folding position set on or downstream of the sheet stacking means;
A sheet folding device that folds the sheet bundle arranged at the folding position and accumulated by the sheet accumulating means,
A post-processing apparatus, wherein the sheet folding apparatus has the configuration according to any one of claims 1 to 5. The post-processing apparatus according to claim 6, wherein a stapler for binding the bundle of sheets reaching the folding position is disposed on the sheet stacking unit or on the downstream side thereof. The post-processing apparatus according to claim 6,
A second sheet stacking unit that arranges the sheets sequentially arranged and arranged at a position different from the sheet stacking unit in a bundle shape;
Saddle stitching staple means for binding the sheet stacking means or the center of a sheet bundle arranged downstream thereof and reaching the folding position;
Edge-bound staple means for binding the edges of the sheet bundle accumulated in the second sheet accumulation means;
And a post-processing apparatus. An image forming apparatus for sequentially forming images on sheets;
A post-processing device that performs post-processing such as stapling, stamping, and punching on the sheet from the image forming apparatus,
An image forming system comprising the post-processing apparatus having the configuration according to any one of claims 6 to 8.

Images