Patent Application
20250197158
The present invention relates to a sheet binding processing apparatus capable of executing binding processing for a sheet with an image formed thereon, and an image forming system including the sheet binding processing apparatus.
A sheet post-processing apparatus is known as an apparatus connected to the discharge port of an image forming apparatus and configured to temporarily hold, on a tray, a sheet with an image formed, perform post-processing, and store the sheet in a storage stacker. As the post-processing, processing of stacking sheets and binding a sheet bundle is known.
Japanese Patent Laid-Open No. 2013-230891 describes a sheet loading apparatus capable of preventing a deviation when aligning a plurality of sheets loaded on a loading tray. Japanese Patent Laid-Open No. 2018-47964 discloses an apparatus in which, to improve productivity in continuous bundle processing, if sheets of a subsequent bundle are conveyed during post-processing of a preceding bundle, the sheets are switchback-conveyed and buffered.
When continuously performing bundle processing, in the buffer operation disclosed in Japanese Patent Laid-Open No. 2018-47964, it is impossible to feed a sheet onto the processing tray and buffer it. For example, when a bundle under processing or discharge is nipped by a discharge roller, a subsequent sheet whose length is longer than a predetermined length is blocked by the discharge roller and cannot be buffered.
The present invention provides a sheet binding processing apparatus capable of performing a buffer operation even if a subsequent sheet whose length is longer than a predetermined length is accepted during post-processing, and an image forming system including the sheet binding processing apparatus.
The present invention in one aspect provides a sheet binding processing apparatus comprising: a conveyance path configured to convey a sheet from a path inlet to a path outlet; a conveyance unit provided in the conveyance path and configured to convey the sheet; a tray configured to accept, from above, the sheet conveyed on the conveyance path; a binding unit configured to perform a binding process for binding a sheet bundle on the tray; a pair of discharge rollers configured to discharge the sheet bundle that is performed the binding process by the binding unit; a buffer path branching downward from the conveyance path and configured to, if a preceding sheet bundle exists on the tray, buffer a sheet that forms a subsequent sheet bundle; a buffer conveyance unit provided on the buffer path and configured to convey the sheet; an upper branching path branching upward from the conveyance path; an upper conveyance unit provided on the upper branching path and configured to convey the sheet; and a control unit configured to, when performing the binding process for continuously binding a sheet bundle including a predetermined sheet which is longer than a predetermined length in a conveyance direction, control the conveyance unit, the buffer conveyance unit, and the upper conveyance unit such that a sheet that forms a subsequent sheet bundle is sent from the conveyance path to the upper branching path, and the sheet is then conveyed in a switchback direction from the upper branching path to the buffer path.
According to the present invention, it is possible to buffer a subsequent sheet whose length is longer than a predetermined length even if a sheet exists on a processing tray.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but limitation is not made an invention that requires all such features, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.
An image forming apparatus A in an image forming system shown in
The feeding unit 2 is configured to include cassette mechanisms 2a to 2c that store sheets of a plurality of sizes to form images, and feeds a sheet of a size designated by a main body control unit 90 to a feeding path 6. Hence, the plurality of cassettes 2a to 2c are detachably arranged in the apparatus housing 1, and each cassette incorporates a separation mechanism that separates the sheets inside one by one, and a feeding mechanism that feeds the sheets. In the feeding path 6, conveyance rollers 7 that feed sheets supplied from the plurality of cassettes 2a to 2c to the downstream side are provided, and a registration roller pair 8 that aligns the leading edge of each sheet is provided at the path end portion.
Note that a large-capacity cassette 2d and a manual tray 2e are connected to the feeding path 6. The large-capacity cassette 2d is configured to include an optional unit that stores sheets of a size to be consumed a lot. The manual tray 2e is configured to supply a special sheet difficult to separately feed, such as a thick sheet, a coating sheet, or a film sheet.
The image forming unit 3 is shown as an example of an electrostatic printing mechanism, and a photosensitive member 9 (a drum or a belt) is provided, and a light emitting device 10 that emits an optical beam to the photosensitive member 9, a developing device 11 (developer), and a cleaner (not shown) are arranged around the rotating photosensitive member. The illustrated mechanism indicates a monochrome printing mechanism, in which a latent image is optically formed on the photosensitive member 9 by the light emitting device 10, and the developing device 11 adheres toner ink to the latent image. In accordance with a timing of forming an image on the photosensitive member 9, a sheet is fed from the feeding path 6 to the image forming unit 3, and the image is transferred to the sheet by a transfer charger 12 and fixed by a fixing unit (roller) 13 arranged in a discharge path 14. In the discharge path 14, discharge rollers 15 and a discharge port (path outlet) 16 are arranged, and the sheet is conveyed to a sheet post-processing apparatus B to be described later.
The scanner unit A2 is configured to include a platen 17 on which an image original is placed, a carriage 18 that reciprocally moves along the platen 17, a light source mounted on the carriage 18, and a reduction optical system 20 (a combination of mirrors and lenses) that guides reflected light from the original on the platen 17 to a photoelectric conversion unit 19. Reference numeral 21 in
The feeder unit A3 is configured to include a feeding tray 22, a feeding path 23 that guides a sheet fed from the feeding tray to the traveling platen 21, and a discharge tray 24 that stores the original that has undergone image reading by the platen.
The image forming apparatus A is not limited to the above-described mechanism, and a printing mechanism such as an offset printing mechanism, an inkjet printing mechanism, or an ink ribbon transfer printing mechanism (thermal transfer ribbon printing, sublimation ribbon printing, or the like) can be employed.
As an apparatus that post-processes a sheet discharged from the discharge port 16 of the image forming apparatus A, the sheet post-processing apparatus B has, for example, (1) a function of loading and storing sheets with images formed thereon (printout mode), (2) a function of sorting and storing sheets with images formed thereon (jog sorting mode), (3) a function of aligning, stacking, and binding sheets with images formed thereon (binding processing mode), and (4) a function of aligning and binding sheets with images formed thereon and then folding the sheets to do bookbinding-finishing (bookbinding processing mode).
Note that in this embodiment, the sheet post-processing apparatus B need not have all the functions described above and is configured appropriately in accordance with apparatus specifications (design specifications). In this embodiment, as an example, the sheet post-processing apparatus B is assumed to have the function of aligning and binding sheets with images formed thereon and then folding the sheets to do bookbinding-finishing.
The processing unit B1 is arranged at the path outlet (straight path discharge port 35) of the straight path 28, and aligns, stacks, and binds sequentially sent sheets and then stores these in the first tray 49. The saddle unit B2 is a post-processing unit that is arranged at the path outlet (saddle path discharge port) of a saddle path 32 branched from the straight path 28 and aligns, stacks, and saddle-stitches (sometimes does not saddle-stitch) sequentially sent sheets, then folds the sheets, and stores these in the second tray 61. The components will be described below in detail.
As shown in
The housing 27 of the sheet post-processing apparatus is configured to include an apparatus frame 70. The apparatus frame 70 forms, for example, a box-shaped apparatus framework as shown in
As shown in
In the straight path 28, as shown in
In the above-described paths, the saddle path 32, the saddle buffer path P2, and the processing unit buffer path P1 are each formed as a switchback path that conveys a sheet in a direction reverse to the conveyance direction from the straight path inlet 26 to the straight path discharge port 35 and loads the sheet to each path. Also, the upper conveyance path 30 is configured to convey a sheet in the same direction as the conveyance direction from the straight path inlet 26 to the straight path discharge port 35, thereby loading the sheet.
The saddle path flapper 33b, the saddle buffer path flapper 33a, and the processing unit buffer path flapper 200, which are the sheet branching mechanisms, are each formed by a flapper guide capable of moving to switch the conveyance path of a sheet loaded from the straight path inlet 26, and connected to a driving mechanism (not shown) such as an electromagnetic solenoid or a mini motor. The saddle path flapper 33b guides a sheet sent from the straight path inlet 26 to the saddle path 32. The saddle buffer path flapper 33a guides a sheet sent from the straight path inlet 26 to the saddle buffer path P2. The processing unit buffer path flapper 200 guides a sheet sent from the straight path inlet 26 to the processing unit buffer path P1 via processing unit buffer rollers 301a and 301b. The upper conveyance path flapper 34 is configured to include a flapper guide capable of moving to switch the conveyance path to convey a sheet sent from the straight path inlet 26 to one of the straight path discharge port 35 and the upper conveyance path 30, and connected to a driving mechanism (not shown) such as an electromagnetic solenoid or a mini motor.
The upper conveyance path 30 (printout discharge path) that loads sheets other than those to be discharged to the straight path discharge port 35 is connected to the straight path 28, and the path branching portion is provided with the upper conveyance path flapper 34 configured to guide a sheet to the upper conveyance path 30. Also, the upper conveyance path 30 includes upper conveyance rollers 303 (303a and 303b) that guide a sheet to the third tray 71. The sheet guided by these to the upper conveyance path 30 is discharged from an upper conveyance path discharge port 40 to the third tray 71 (overflow tray). Note that in this embodiment, the upper conveyance path 30 is also used as a sheet retreat path.
The saddle path 32 configured to load a sheet to the saddle unit B2 is connected to the straight path 28, and the path branching portion is provided with the saddle path flapper 33b configured to guide the sheet to the saddle path 32. The sheet guided from the saddle path 32 to the saddle unit B2 via the saddle path discharge port undergoes saddle-stitching processing and folding processing and is then discharged to the second tray 61 via a saddle discharge path 68 in a substantially horizontal direction.
The saddle buffer path P2 configured to temporarily load a sheet that should undergo saddle-stitching processing and folding processing in the saddle unit B2 and make the sheet stand by is connected to the straight path 28, and the saddle buffer path flapper 33a configured to guide a sheet to the saddle buffer path P2 is formed. Also, the saddle buffer path P2 includes conveyance rollers 302 (302a and 302b) that load a sheet and make it temporarily stand by.
A fourth tray discharge port 305 is provided on the extension on the downstream side of the saddle buffer path P2 and, therefore, a sheet loaded into the saddle buffer path P2 can be discharged onto a fourth tray 310 and loaded on it. In this case, the fourth tray 310 is arranged vertically above the saddle buffer path P2. Note that the fourth tray 310 may be shared as an exterior component of the top surface of the sheet post-processing apparatus B, or may be fixed to apparatus housing. The fourth tray 310 may be configured to include a driving mechanism and be movable up/down in a substantially vertical direction.
Note that when the saddle buffer path P2 is arranged at a position to overlap vertically above the punch unit 100, the apparatus can be made more compact. However, if a space is needed to spring the punch unit 100 up to remove a sheet staying in the punch unit 100, the saddle buffer path P2 may be arranged at a position not to overlap vertically above the punch unit 100.
A conveyance shift mechanism of conveyance rollers on the conveyance path will be described here with reference to
Each conveyance roller described above is rotatably attached to a shift member 117 that connects the driving roller shaft 113 and the driven roller shaft 114. By the shift member 117, the driving roller shaft 113 and the driven roller shaft 114 are connected to integrally move in the axial direction (thrust direction), and can independently rotate in the radial direction. The driving roller shaft 113 is supported, via bearings, by the left and right side frames 70f and 70r, an end portion of the driving roller shaft 113 is located in a range indicated by the axial-direction moving region of the conveyance roller on the front side of the side frame 70f, and the other end portion is located on the rear side of the side frame 70r. The shift member 117 (for example, a block member of a synthetic resin) is supported by the driving roller shaft 113 and the driven roller shaft 114 and integrally connects the two roller shafts.
A rack 117a is integrally formed on the shift member 117 and meshed with a shift motor M9 attached to the side frame 70r (the apparatus housing: the same applies hereafter) and a transmission pinion 117b. In this configuration, the shift member 117 can be moved (shift-moved) in the axial direction of the conveyance roller by the rotation of the shift motor M9 (a stepping motor capable of rotating in forward and reverse directions is shown).
A passive gear 118 is integrally formed on the driving rotation shaft 115, and the rotation of the driving motor is transmitted to the passive gear 118. In addition, a conveyance roller pair (a driving roller and a driven roller) is in pressure contact with a driven rotation shaft 119 such that it is driven and rotated by the rotation of the driving rotation shaft 115.
In this embodiment, the driving rotation shaft 115 and the driven rotation shaft 119 are connected to each other and configured such that when one of the rotation shafts moves in the axial direction, the other is driven. In addition, one of the driving roller 111 and the driven roller 112 may be attached to a rotation shaft such that it can slidably move (slide) in the axial direction, and the other roller may be moved in the axial direction such that it is linked with the movement.
A shift operation (jog sorting mode) of a sheet loaded into the sheet post-processing apparatus B will be described here. A sheet sent from the image forming apparatus A is conveyed to the straight path inlet 26, the inlet rollers 29, the first conveyance rollers 201, the second conveyance rollers 202, and the third conveyance rollers 203 in this order. At this time, the transfer timing of the sheet is simultaneously detected by the inlet sensor S1. While the sheet loaded by the inlet rollers 29 passes through the straight path 28, an end position of the sheet is detected by the lateral registration detection sensor S0. The lateral registration detection sensor S0 detects how much a lateral registration error X of the sheet has occurred with respect to the center position.
If the lateral registration error X is detected by the lateral registration detection sensor S0, the rollers of the first conveyance rollers 201, the second conveyance rollers 202, and the third conveyance rollers 203 move by predetermined amounts to near and far sides while sequentially conveying the sheet, thereby performing the shift operation of the sheet (to be also referred to as “lateral registration detection processing”). After that, the sheet is distributed and conveyed to the straight path discharge port 35 or the upper conveyance path 30 by the upper conveyance path flapper 34 that is a branching mechanism, and discharged onto the first tray 49 or the third tray 71.
The processing unit B1 is a post-processing unit configured to include a processing tray 37 that is arranged on the downstream side of the straight path 28 and aligns and stacks a sheet sent from the straight path discharge port 35, and a binding processing mechanism that binds a stacked sheet bundle. As shown in
A sheet loading mechanism that loads the sheet from the discharge port onto the tray is arranged between the straight path discharge port 35 and the processing tray 37. In the processing tray 37, a positioning mechanism that positions a sheet at a predetermined binding position and a sheet bundle unloading mechanism that discharges the bound sheet bundle to the first tray 49 on the downstream side are arranged. The components will be described later.
Note that the processing tray 37 shown in
The saddle unit B2 is a post-processing unit that aligns and stacks sheets sent from the straight path 28, binds the sheets at the center portion, and fold these inward (to be referred to as “magazine finishing” hereinafter). The second tray 61 is arranged on the downstream side of the saddle unit B2 to store the sheet bundle that has undergone bookbinding processing. Note that the saddle unit may be configured to align and stack one or a plurality of sheets and only fold these inward at the center portion without performing saddle-stitching processing.
The saddle unit B2 is configured to include a guide member 66 that stacks sheets in a bundle, a leading edge regulating stopper 67 that positions a sheet at a predetermined position on the guide member 66, a staple device 63 (saddle-stitching staple unit) that saddle-stitches, at the center portion, the sheets positioned by the leading edge regulating stopper 67, and a folding processing mechanism (a folding roll pair 64 and a folding blade 65) that folds the sheet bundle at the center portion after the binding processing.
As the saddle-stitching staple unit 63, a generally known mechanism that moves, along a sheet center portion (line), a sheet bundle sandwiched between a head unit and an anvil unit and performs binding processing is employed. The folding processing mechanism is configured such that, as shown in
The processing unit B1 and the straight path 28 shown in
The second tray 61 is arranged on the downstream side of the saddle unit B2, and a sheet bundle folded like a magazine can be stored. The second tray 61 is arranged on the lower side of the first tray 49. This is because the use frequency of the first tray 49 is assumed to be higher than the use frequency of the second tray 61, and the position of the first tray 49 is set as a height to easily extract a sheet on the tray.
The punch unit 100 that is arranged in the straight path 28 and punches punch holes in a sheet sent from the straight path inlet 26 will be described with reference to
Reference numeral 104 in
As shown in
The drive cam is formed by a cylindrical cam member pivotally attached to the driving rotation shaft 107 and corresponding to the plurality of punch members 101, and each punch member is connected to the cam member via a connecting pin. When the driving rotation shaft 107 rotates by a predetermined angle, the punch members 101 vertically move in the punching direction. At this time, the punch members 101b and 101d of a first group (for example, two-hole punching) in the plurality of punch members vertically move in the punching direction at a first rotation angle of the driving rotation shaft 107. At a different second rotation angle, the punch members 101a, 101c, and 101e of a second group (for example, three-hole punching) vertically move in the punching direction.
Hence, when the driving rotation shaft 107 is reciprocally rotated within a preset angle range under the control of the motor M7, a binding processing control unit 95 to be described later causes the punch members 101b and 101d of the first group to make a punching motion. When the driving rotation shaft 107 is reciprocally moved within a different angle range, the punch members 101a, 101c, and 101e of the second group can be caused to make a punching motion.
The waste box 104 is arranged under the punch members 101 and supported by a guide rail (not shown) provided in the apparatus frame, and can be detached from the apparatus front side.
The driving motor M7 is connected to the driving rotation shaft 107 via a deceleration mechanism (gear transmission mechanism). To allow an operator to manually make rotation, a rotation member is inserted to a hole provided in the side frame 70f and arranged on the front side of the side frame 70f. A front cover is openably and closably arranged on the apparatus front side, and in an open state, the rotation operation member 106 can be operated. Note that in the cover open state, the driving power to the driving motor M7 is not supplied (blocked).
The configurations of the sheet loading mechanism, the sheet positioning mechanism, the binding processing mechanism, and the sheet bundle unloading mechanism of the processing unit B1 will be described next.
As shown in
The reversing conveyance mechanism is configured to include an elevating roller 41 that vertically moves between an operating position at which it engages with a sheet loaded onto the processing tray 37 and a standby position at which it is apart from the sheet, and a paddle rotation body 42 that transfers the sheet to the discharge opposing direction, and the elevating roller 41 and the paddle rotation body 42 are attached to a swing bracket 43.
In the apparatus housing 27, the swing bracket 43 is arranged to be able to swing about a rotation shaft (for example, a discharge roller shaft). The rotation shafts of the elevating roller 41 and the paddle rotation body 42 are supported by the swing bracket 43 via bearings. An elevating motor (not shown) is connected to the swing bracket 43, and the swing bracket 43 vertically moves the elevating roller 41 and the paddle rotation body 42, which are mounted thereon, between the operating position at which the elevating roller 41 engages with a sheet and the standby position at which it is apart from the sheet.
Also, a driving motor (not shown) is connected to the elevating roller 41 and the paddle rotation body 42 to transmit driving such that the elevating roller 41 rotates in forward and reverse directions, and the paddle rotation body 42 rotates in the reversing direction (discharge opposing direction). A driven roller 48 that is in pressure contact with the elevating roller 41 is arranged in the processing tray 37 to nip a single sheet or a bundle of sheets and discharge it to the downstream side.
A guide mechanism that guides the trailing edge of a sheet loaded onto the processing tray 37 toward a sheet end regulating portion 38 is arranged between the elevating roller 41 and the raking rotation body 46 to be described later. The guide mechanism is configured to include the sheet guide member 44 that vertically moves from a dotted line state to a solid line state in
Positioning mechanisms 38 and 39 that position a sheet at a predetermined binding position are arranged on the processing tray 37, and those shown in
As shown in
As shown in
That is, the moving stroke of the left and right side edge alignment plates 39F and 39R is set based on the moving amount to align a different size sheet and the offset amount of a sheet bundle after alignment. Note that in corner binding, the side edge alignment plates 39F and 39R move a sheet unloaded with the center reference, by a predetermined amount, to the right side in a case of right corner binding or to the left side in a case of left corner binding (offset movement). The offset movement is executed every time a sheet is loaded to the processing tray 37 (for each loaded sheet), or executed to move a bundle to perform binding processing after sheets are aligned into the bundle.
Hence, as shown in
The side edge alignment plates 39F and 39R are slidably supported by a plurality of guide rolls 80 on the tray rear surface, and racks 81 are integrally formed. Alignment motors M1 and M2 are connected to the left and right racks 81 via pinions 82. The left and right alignment motors M1 and M2 are each formed by a stepping motor, and are configured to detect the positions of the left and right side edge alignment plates 39F and 39R by position sensors (not shown) and, based on detection values, move the alignment members in both left and right directions by a designated moving amount. Note that the configuration is not limited to the rack-and-pinion mechanism shown in
In the above-described configuration, the binding processing control unit 95 to be described later makes the left and right side edge alignment plates 39F and 39R stand by at predetermined standby positions (width size of sheet+α position) based on sheet size information provided from the image forming apparatus A. In “multi-binding”, a sheet is loaded onto the processing tray 37, and an alignment operation is started at a timing when a sheet end abuts against the sheet end regulating portion 38. The alignment operation is performed by rotating the left and right alignment motors M1 and M2 by the same amount in opposite directions (approaching directions). Then, the sheet loaded onto the processing tray 37 is positioned based on the sheet center as the reference, and stacked into a bundle. The sheet loading operation and the alignment operation are repeated, thereby aligning and stacking sheets in a bundle on the processing tray 37. At this time, sheets of different sizes are positioned with the center reference. In “corner binding”, a sheet is loaded onto the processing tray 37, and an alignment operation is started at a timing when a sheet end abuts against the sheet end regulating portion 38. The alignment operation is performed by setting different moving amounts for the alignment plate on the binding position side and the alignment plate on the opposite side of the binding position. The moving amounts are set such that a sheet corner is located at a preset binding position.
On the processing tray 37, a binding processing mechanism 47 that binds a sheet bundle stacked on the sheet placement surface 37a is arranged. The sheet placement surface 37a of the processing tray 37 is positioned to a predetermined binding position by a positioning mechanism (the sheet end regulating portion 38 and the side edge alignment portion 39). The binding processing mechanism 47 is formed as a binding unit 47 (“staple unit”: the same applies hereafter) that needle-binds a sheet bundle using staple needles.
On the processing tray 37, the binding processing mechanism 47 that binds the trailing edge of a sheet loaded from the straight path discharge port 35 is arranged. As shown in
Note that in binding processing other than binding processing of binding the sheet corner, for example, in a multi-binding mode to be described later, the binding processing control unit 95 to be described later aligns a sheet with the center reference. In this case, the left and right side edge alignment plates 39F and 39R move from the standby positions toward the sheet center by the same amount, thereby positioning the sheet to the binding position.
This will be described with reference to
As shown in
On the first traveling rail 53 and the second traveling rail 54, the rail surface 53x and the traveling cam surface 54x are formed such that the moving unit reciprocally moves in its moving range. As shown in
The staple unit 47 engages with the first traveling rail 53 and the second traveling rail 54 in the following way. As shown in
With the above-described configuration, the staple unit 47 is supported on the apparatus frame 27b such that is can be moved by the sliding roller 47x and the guide roller 47y. Also, the first rolling roller 83 and the second rolling roller 84 travel in accordance with the rail surface 53x and the cam surface 54x, respectively, while rotating along the traveling rail surface 53x and the traveling cam surface 54x.
As shown in
A sheet bundle unloading mechanism that unloads a sheet bundle that has undergone binding processing to the first tray 49 on the downstream side is arranged on the processing tray 37. As a configuration for conveying a sheet bundle to the downstream side, a method (unloading roller mechanism) of conveying a sheet bundle by rollers in pressure contact with each other and a conveyor mechanism that extrudes a sheet trailing edge by an extruding member that moves along the tray surface from the upstream side to the downstream side are known. The apparatus shown in the drawings employs both methods.
Hence, the conveyor mechanisms 45 and 45v that transfer the sheet bundle by extruding it from the upstream side to the downstream side and the unloading roller mechanisms 48 and 41 that nip the sheet bundle and unload it are arranged on the processing tray 37.
The configuration of the above-described staple unit will be described with reference to
In the drive cam 47d, a staple head 47b and an anvil member 47c are arranged at the binding position to face each other. The staple head 47b is biased by a biasing spring (not shown) of the drive cam 47d from the standby position on the upper side to the staple position (anvil member) on the lower side and vertically moves. A needle cartridge 52 is detachably attached to the unit frame 47a.
The needle cartridge 52 stores linear blank needles, and the needles are supplied to the staple head 47b by a needle feed mechanism. The staple head portion 47b incorporates a former member that bends a linear needle into a U shape, and a driver that presses a bent needle into a sheet bundle. With this configuration, the drive cam 47d is rotated by the driving motor M4 to energize the biasing spring. When the rotation angle reaches a predetermined angle, the staple head portion 47b moves down to the side of the anvil member 47c with great force. By this operation, a staple needle is bent into a U shape and then inserted into the sheet bundle by the driver. The tips of the needle are bent by the anvil member 47c, thereby performing staple binding.
The needle feed mechanism is incorporated between the needle cartridge 52 and the staple head 47b, and a sensor (empty sensor) that detects absence of needles is arranged in the needle feed mechanism. Also, a cartridge sensor (not shown) that detects whether the needle cartridge 52 is inserted or not is arranged in the unit frame 47a.
The needle cartridge 52 employs a structure in which layers of staple needles connected in a band are stacked and stored in a cartridge having a box shape, and a structure in which staple needles are stored in a roll shape. The unit frame 47a is provided with a circuit that controls the above-described sensors, and a circuit board that controls the driving motor M4, and is configured to generate an alarm signal when the needle cartridge 52 is not stored or stable needles are absent. The staple control circuit is configured to control the driving motor M4 to execute the staple operation by a staple needle signal, and generate an “operation end signal” when the staple head portion 47b moves from the standby position to the staple position and returns to the standby position again.
A control configuration in the image forming system shown in
“Image forming mode” and “post-processing mode” are set based on a user operation accepted via the input unit 93 (control panel). In the image forming mode, for example, a mode such as color/monochrome printing or doubles-sided/single-sided printing is set, and image forming conditions such as a sheet size, sheet quality, the number of printout copies, and resizing printing are set. Also, in the “post-processing mode”, for example, “printout mode”, “bookbinding processing discharge mode”, “staple binding processing mode”, or “jog sorting mode” is set.
Also, the main body control unit 90 transfers, to the binding processing control unit 95, data indicating that the mode is the post-processing mode and data indicating the number of sheets, copy count information, and sheet thickness information of sheets to form images. At the same time, the main body control unit 90 transfers a job end signal to the binding processing control unit 95 every time image formation is ended.
The post-processing mode will be described. The “printout mode” is a mode in which sheets from the straight path discharge port 35 are stored in the stack tray 49 via the processing tray 37 without binding processing. In this case, the sheets are stacked on the processing tray 37 in an overlapped state, and a sheet bundle after stacking is unloaded to the stack tray 49 in accordance with the job end signal from the main body control unit 90.
The “bookbinding processing discharge mode” is a mode in which sheets with images formed thereon are aligned and bound and then folded to do bookbinding-finishing. Details will be described with reference to
The “staple binding processing mode” is a mode in which sheets from the straight path discharge port 35 are stacked and aligned on the processing tray 37, and the sheet bundle is bound and then stored in the stack tray 49. In this case, an operator designates such that the sheets to form images have the same sheet thickness and the same size. In the staple binding processing mode, one of “multi-binding”, “right corner binding” and “left corner binding” is selected and designated.
In the “jog sorting mode”, sheets with images formed by the image forming apparatus A are divided into a group to be offset-moved and stacked and a group to be stacked without being offset-moved. Sheet bundles that are offset-moved and sheet bundles that are not offset-moved are alternately stacked on the stack tray.
The binding processing control unit 95 causes the sheet post-processing apparatus B to operate in accordance with the post-processing mode set by the main body control unit 90. The binding processing control unit 95 is configured to include a control CPU. A ROM 96 and a RAM 97 are connected to the binding processing control unit 95, and the operation of the sheet post-processing apparatus B according to this embodiment is executed based on a control program stored in the ROM 96 and control data stored in the RAM 97. Hence, the binding processing control unit 95 controls the driver circuits of all the driving motors described above, thereby starting/stopping the motors and controlling forward/reverse rotations.
Even during post-processing in the processing unit B1, image formation is continuously performed by the image forming apparatus A. In this embodiment, a buffer operation of accumulating, in the sheet post-processing apparatus B, sheets conveyed from the image forming apparatus A is performed. This makes it possible to continuously perform post-processing without lowering the frequency of supplying sheets from the image forming apparatus A, that is, without lowering productivity of the image forming apparatus A.
The outline of the sheet buffer operation in the sheet post-processing apparatus B will be described with reference to
In
Possible positions of the sheet support 401 will be described here.
For example, in the sheet post-processing apparatus B, an operation of making a sheet conveyed from the side of the second conveyance rollers 202 pass through the third conveyance rollers 203 causing the processing unit buffer path flapper 200 to pivot downward at the timing when the trailing edge of the sheet passes through the second conveyance rollers 202, reversing the conveyance direction of the sheet, and guiding and conveying it to the processing unit buffer path P1 (reversing conveyance) is performed. To quickly perform the operation, the arm length of the processing unit buffer path flapper 200 is formed long. On the other hand, when the pivot space of the processing unit buffer path flapper 200 is large, the interval between the second conveyance rollers 202 and the third conveyance rollers 203 is large. As a result, the leading edge of the sheet conveyed from the side of the second conveyance rollers 202 may hang down to cause jam or the like. In this embodiment, when conveying a sheet on the straight path 28 formed by the second conveyance rollers 202 and the third conveyance rollers 203, the sheet support 401 is moved to the support position, as shown in
In
The upper conveyance path 30 aims at preventing the subsequent sheet to be buffered from projecting to the side of the elevating roller 41 and the driven roller 48 at the time of buffering. The subsequent sheet is conveyed at various timings. If a sheet exists on the processing tray 37 of the binding unit 47, the elevating roller 41 and the driven roller 48 may nip and stop, or may nip and discharge a bundle at a low speed. At this timing, the subsequent sheet that is longer than a predetermined length and conveyed at a speed higher than the bundle discharge speed is blocked at the nip position between the elevating roller 41 and the driven roller 48 of the binding unit 47 and cannot be conveyed to the position where it can be buffered. For this reason, the subsequent sheet that is longer than the predetermined length is temporarily sent to the upper conveyance path 30 to perform the buffer operation without making the subsequent sheet that is longer than the predetermined length projecting to the side of the elevating roller 41 and the driven roller 48.
The buffer operation according to this embodiment is effective when a preceding sheet bundle exists on the processing tray 37 of the binding unit 47, and a subsequent sheet is a predetermined size sheet longer than a predetermined length. More specifically, the predetermined size sheet indicates, for example, a sheet type like A3 size that is long in the conveyance direction and requires high productivity. For special long paper for which the productivity of the image forming apparatus main body needs to be low, the necessity of buffering cannot occur. Note that as the information of the sheet size, sheet information included in print setting information transmitted from the image forming apparatus main body is used.
Whether the subsequent sheet is the predetermined size sheet is determined based on how much the leading edge of the subsequent sheet projects onto the processing tray 37 when the trailing edge of the sheet is located at the branch of the processing unit buffer path P1. During binding processing of the binding unit 47, the elevating roller 41 and the driven roller 48 nip and stop. Hence, if the subsequent sheet projecting from the discharge rollers 36 reaches the nip point between the elevating roller 41 and the driven roller 48, the sheet is blocked and cannot be buffered. On the other hand, if the subsequent sheet projecting from the discharge rollers 36 does not reach the nip point between the elevating roller 41 and the driven roller 48, instead of sending the sheet to the upper conveyance path 30, the sheet may be switchback-conveyed to the processing unit buffer path P1 from a state in which the sheet stays on the straight path 28. In this case, since the sheet can be conveyed only by the third conveyance rollers 203, the number of rollers to be driven can be decreased.
Also, in this embodiment, a case where above-described predetermined size sheets, that is, sheets long in the conveyance direction are continuously bound has been described. The configuration is also effective even when connecting different jobs. For example, if a sheet bundle with A4 size on the processing tray 37 of the binding unit 47 is bound by a preceding job, and at least one sheet of A3 size is discharged to the first tray 49 by the subsequent job, the sheet can be sent without delaying image formation of the A3 sheet.
As described above, according to this embodiment, in the configuration in which post-processing is executed for sheets continuously supplied from the image forming apparatus A, the productivity can be further improved.
Note that an operation in a case where the preceding sheet bundle SS1 exists has been described above. If the preceding sheet bundle SS1 does not exist, the above-described buffer operation is not performed for a sheet supplied from the image forming apparatus A. In this case, for example, the above-described buffer operation to the upper conveyance path 30 is not performed for the sheet supplied from the image forming apparatus A, reverse conveyance from the straight path 28 to the processing unit buffer path P1 is performed, and after that, the sheet is conveyed up to the elevating roller 41 and the driven roller 48 in synchronism with a sheet newly supplied from the image forming apparatus A to the straight path inlet 26. Then, the elevating roller 41 and the driven roller 48 are rotated in the reverse direction, thereby conveying the sheet bundle to the binding unit 47.
In addition, the upper conveyance path 30 also serves as a path used to discharge a sheet to the third stack tray 71. Sheets of another job are loaded on the third stack tray 71 to prevent loading mixture with the first stack tray 49. The third stack tray 71 can also be used to discharge a sheet determined as an error sheet by an image error recognition unit (not shown) or a sheet remaining in the apparatus at the time of occurrence of an apparatus jam.
As for binding processing of the binding unit 47, in this embodiment, binding processing for binding sheets using needles has been described as an example. Various methods such as crimp binding for crimping and binding sheets and binding processing performed for several points can be employed. Even when performing post-processing that takes time, the operation can be performed without stopping the operation of the image forming apparatus. Also, when the subsequent sheet is sent to the upper conveyance path 30, it is possible not only to avoid the nip point between the elevating roller 41 and the driven roller 48 but also to avoid contact with a sheet on the processing tray 37, prevent disturbance to alignment of already loaded sheets, and avoid contact with other mechanisms in the processing tray 37.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2023-212307, filed Dec. 15, 2023, and Japanese Patent Application No. 2024-190841, filed Oct. 30, 2024 which are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-212307 | Dec 2023 | JP | national |
| 2024-190841 | Oct 2024 | JP | national |
