JP2015013706A - Sheet processing device and image formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet processing device and an image formation system capable of restraining a binding member from being deformed by increasing folding operation, by increasing folding roller pairs, while securing the increasing folding effect.SOLUTION: The sheet processing device comprises: folding means 230 for applying folding processing by sandwiching a sheet bundle with the vicinity of a binding part bound by binding members 50a and 50b of the sheet bundle as a folding position; increasing folding roller pairs 266 for increasingly folding a fold line of the sheet bundle while moving in a sheet width direction by arranging a pair of roller members having a shaft in the orthogonal direction to the sheet width direction so as to sandwich the sheet bundle; and energizing means 265 for imparting energizing force for pressing at least one roller member of the increasing folding roller pairs to the fold line, to the roller members, and comprises: energizing force changing means for changing the energizing force when the binding members pass through a certain part when the increasing folding roller pairs move the fold line in the sheet width direction so as to become weaker than the energizing force just before the increasing folding roller pairs pass through the binding members.

Description

  The present invention relates to a sheet processing apparatus used in an image forming system including an image forming apparatus such as a printer, a facsimile machine, and a copying machine, and an image forming system including the sheet processing apparatus.

  As a sheet processing apparatus of this type, saddle stitching is performed at the center of a sheet bundle composed of a plurality of sheets on which an image has been formed by the image forming apparatus, and the bound sheet bundle is folded in half to create a saddle stitched booklet. Things are known.

  The sheet processing apparatus described in Patent Document 1 includes a stapler that is a binding unit that drives a metal needle as a binding member into a central portion of a sheet bundle to bind the sheet bundle. Further, the sheet bundle is disposed so as to face the folding position of the saddle-stitched sheet bundle, the folding plate pushing the sheet bundle in a direction perpendicular to the sheet surface, with the movement path of the folding plate interposed therebetween. A pair of folding rollers.

  Then, the front end of the folding plate is brought into contact with the binding position of the sheet bundle that is saddle-stitched by the stapler with the stapler, and the sheet bundle is pushed from the binding position into the nip of the folding roller pair, and the sheet bundle is sandwiched between the folding roller pair. By conveying, the sheet bundle is folded.

  Further, the folded sheet bundle is conveyed downstream of the pair of folding rollers in the sheet bundle conveyance direction, and receives a driving force from a drive motor to reciprocate in the sheet width direction which is a direction perpendicular to the sheet bundle conveyance direction. An additional folding roller pair that moves and further folds the folds of the sheet bundle is provided.

  The pair of additional folding rollers has an axis in the sheet bundle conveying direction, and at least one of the first roller member and the second roller member pressed against the fold by the urging force from the compression spring is folded by the pair of folding rollers. Oppositely arranged so as to sandwich the sheet bundle. Then, the additional folding roller pair reciprocates in the sheet width direction while sandwiching the fold of the sheet bundle while urging at least one of the first roller member and the second roller member with a compression spring, and the fold is further folded. Is made.

  However, during the additional folding operation of the fold by the additional folding roller pair, the metal needle binding the sheet bundle is also pushed by the roller member of the additional folding roller pair. Therefore, if the urging force is too strong, the metal needle is bent, and the quality of the saddle stitched booklet is deteriorated. On the other hand, if the urging force is simply weakened, the folding force of the pair of additional folding rollers is weakened, so that a sufficient additional folding effect cannot be obtained.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet processing apparatus capable of suppressing the deformation of the binding member due to the additional folding operation by the additional folding roller pair while ensuring the additional folding effect, and An image forming system including the sheet processing apparatus is provided.

  In order to achieve the above object, the invention of claim 1 comprises a folding means for sandwiching the sheet bundle and folding the sheet bundle with the vicinity of the binding portion bound by the binding member of the sheet bundle as a folding position. A pair of roller members having axes perpendicular to the sheet width direction are arranged so as to sandwich the sheet bundle folded by the folding means, and the folds of the sheet bundle are increased while moving in the sheet width direction. A sheet processing apparatus comprising: an additional folding roller pair that folds; and a biasing unit that applies a biasing force that presses at least one roller member of the additional folding roller pair to the fold. Moves in the sheet width direction, and the biasing force when passing through the portion with the binding member is weaker than the biasing force when passing through the portion without the binding member. It is characterized in that it has a biasing force changing means for changing the.

  As described above, according to the present invention, there is an excellent effect that the binding member can be prevented from being deformed by the additional folding operation by the additional folding roller pair.

The figure which shows the state which provided the notch part corresponding to the binding member in each of the 2nd guide route and the 5th guide route of a guide member. 1 is a diagram showing a system configuration of an image forming system according to an embodiment. FIG. 3 illustrates an image forming apparatus. The figure explaining a saddle stitch bookbinding apparatus. FIG. 6 is an operation explanatory view of the saddle stitch bookbinding apparatus and shows a state when the sheet bundle is carried into a half-fold conveyance path. FIG. 9 is an operation explanatory diagram of the saddle stitch bookbinding apparatus and shows a state at the time of saddle stitching of a sheet bundle. FIG. 6 is an operation explanatory diagram of the saddle stitch bookbinding apparatus and shows a state when the movement to the center folding position of the sheet bundle is completed. FIG. 10 is an operation explanatory diagram of the saddle stitch bookbinding apparatus, and shows a state when a sheet bundle is subjected to a middle folding process. FIG. 9 is an operation explanatory diagram of the saddle stitch bookbinding apparatus and shows a state at the time of paper discharge after the folding of the sheet bundle is completed. The principal part front view which shows an additional folding roller unit and a folding roller pair. The principal part side view which looked at FIG. 10 from the left side. The figure which shows the detail of a guide member. It is a figure which expands and shows the principal part of FIG. 12, and is a figure which shows a state when the path | route switching nail | claw is not switched. It is a figure which expands and shows the principal part of FIG. 12, and is a figure which shows the state by which the 1st path | route switching nail | claw was switched. Operation | movement explanatory drawing which shows the initial state of an additional folding operation | movement. Operation | movement explanatory drawing which shows the state at the time of the forward movement start of an additional folding roller unit. FIG. 9 is an operation explanatory diagram illustrating a state when the third folding path is reached near the center of the sheet bundle of the additional folding roller unit. Operation | movement explanatory drawing which shows a state when an additional folding roller unit pushes a 1st path | route switching claw into a 2nd guidance path | route. FIG. 10 is an operation explanatory diagram illustrating a state when the additional folding roller unit moves in the end direction while pressing the sheet bundle. Operation | movement explanatory drawing which shows a state when an additional folding roller unit moves to the final position of an outward movement along a 2nd guide route. Explanatory drawing which shows a state when an additional folding roller unit starts a backward movement from the last position of a forward movement. Operation | movement explanatory drawing which shows a state when an additional folding roller unit starts a backward movement, and reached the 6th guidance path | route. Operation | movement explanatory drawing which shows a state when an additional folding roller unit reaches the 6th guidance path | route, and transfers to a press state from a press release state. Operation | movement explanatory drawing which shows a state when it will be in a perfect press state, if an additional folding roller unit enters a 5th guide path | route. Operation | movement explanatory drawing which shows a state when an additional folding roller unit moves to a 5th guide path | route as it is, and returned to the initial position. Operation | movement explanatory drawing which shows the initial state of an additional folding operation | movement. Operation | movement explanatory drawing which shows the state at the time of the forward movement start of an additional folding roller unit. FIG. 9 is an operation explanatory diagram illustrating a state when the third folding path is reached near the center of the sheet bundle of the additional folding roller unit. Operation | movement explanatory drawing which shows a state when an additional folding roller unit pushes a 1st path | route switching claw into a 2nd guidance path | route. FIG. 10 is an operation explanatory diagram illustrating a state when the additional folding roller unit moves in the end direction while pressing the sheet bundle. Operation | movement explanatory drawing which shows a state when an additional folding roller unit moves to the final position of an outward movement along a 2nd guide route. Explanatory drawing which shows a state when an additional folding roller unit starts a backward movement from the last position of a forward movement. Operation | movement explanatory drawing which shows a state when an additional folding roller unit reaches the 6th guidance path | route, and transfers to a press state from a press release state. Operation | movement explanatory drawing which shows a state when an additional folding roller unit reaches the 6th guidance path | route, and transfers to a press state from a press release state. Operation | movement explanatory drawing which shows a state when it will be in a perfect press state, if an additional folding roller unit enters a 5th guide path | route. Operation | movement explanatory drawing which shows a state when an additional folding roller unit moves to a 5th guide path | route as it is, and returned to the initial position. Explanatory drawing of the point regarding the speed control of an additional folding roller unit.

  FIG. 2 is a diagram illustrating a system configuration of an image forming system 4 including an image forming apparatus and a sheet processing apparatus in the present embodiment. In the image forming system 4 of the present embodiment, a saddle stitch bookbinding apparatus 2 that is a sheet post-processing apparatus is provided at a subsequent stage of the image forming apparatus 3.

  The image forming apparatus 3 forms an image on a sheet based on input image data or image data of a read image. For example, a copier, a printer, a facsimile machine, or a digital multifunction machine having at least two of these functions corresponds to this. The image forming apparatus 3 is a known system such as an electrophotographic system or a droplet ejection system, and any image forming system may be used. In this embodiment, an electrophotographic copying machine is used.

FIG. 3 is a diagram illustrating the image forming apparatus 3.
In the image forming apparatus main body 400, a feeding cassette that stores a sheet as a recording medium is disposed below the image forming unit. The sheets stored in the feeding cassette are fed by feeding rollers 414 a and 414 b, respectively, and then conveyed upward along a predetermined conveyance path to reach the registration roller pair 413.

  The image forming unit includes a photosensitive drum 401 as an image carrier, a charging device 402, an exposure device 410, a developing device 404, a transfer device 405, and a cleaning device 406.

  The charging device 402 is a charging unit that uniformly charges the surface of the photosensitive drum 401. The exposure device 410 is a latent image forming unit that forms an electrostatic latent image on the photosensitive drum 401 based on image information read by the image reading device 100. The developing device 404 is a developing unit that visualizes an electrostatic latent image on the photosensitive drum 401 by attaching toner. The transfer device 405 is a transfer unit that transfers the toner image on the photosensitive drum 401 to a sheet. The cleaning device 406 is a cleaning unit that removes toner remaining on the photosensitive drum 401 after transfer.

  A fixing device 407 as a fixing unit that fixes the toner image on the sheet is disposed downstream of the image forming unit in the sheet conveyance direction.

  The exposure apparatus 410 emits laser light based on image information under the control of a control unit (not shown) and the laser light from the laser unit 411 in the rotation axis direction (main scanning direction) of the photosensitive drum 401. A polygon mirror 412 for scanning is provided.

  An automatic document feeder 500 is connected to the upper part of the image reading apparatus 100. The automatic document feeder 500 includes a document table 501, a document separating and feeding roller 502, a conveyor belt 503, and a document discharge tray 504.

  When an original is set on the original table 501 and an instruction to start reading is received, the automatic original conveying apparatus 500 sends out the originals on the original table 501 one by one by the original separation feeding roller 502. Then, the document is guided onto the platen glass 309 by the conveyance belt 503 and temporarily stopped.

  Then, the image information of the original temporarily stopped on the platen glass 309 is read by the image reading apparatus 100. Thereafter, the conveyance belt 503 resumes the conveyance of the document, and the document is discharged to the document discharge tray 504.

Next, an image reading operation and an image forming operation will be described.
When a document is transported on the platen glass 309 by the automatic document transport device 500 or a document is placed on the platen glass 309 by the user and a copy start operation is performed on an operation panel (not shown), the first traveling body 303 is operated. The upper light source 301 is turned on. At the same time, the first traveling body 303 and the second traveling body 306 are moved along a guide rail (not shown).

  The original on the platen glass 309 is irradiated with light from the light source 301, and the reflected light is guided to the mirror 302 on the first traveling body 303, the mirrors 304 and 305 on the second traveling body 306, and the lens 307. The light is received by the CCD 308. As a result, the CCD 308 reads the image information of the document, and the image information is converted from analog data to digital data by an A / D conversion circuit (not shown). The image information is sent from an information output unit (not shown) to the control unit of the image forming apparatus main body 400.

  On the other hand, the image forming apparatus main body 400 starts to drive the photosensitive drum 401, and when the photosensitive drum 401 rotates at a predetermined speed, the charging device 402 uniformly charges the surface of the photosensitive drum 401. Then, an electrostatic latent image based on image information read by the image reading device is formed by the exposure device 410 on the surface of the charged photosensitive drum 401.

  Thereafter, the electrostatic latent image on the surface of the photosensitive drum 401 is developed by the developing device 404 to become a toner image. The sheets stored in the feeding cassette are fed by feeding rollers 414 a and 414 b and temporarily stopped by a registration roller pair 413.

  The toner image formed on the surface of the photosensitive drum 401 is sent to the transfer unit by the registration roller pair 413 at the timing when the leading end of the toner image reaches the transfer unit facing the transfer device 405. When the sheet passes through the transfer portion, the toner image formed on the surface of the photosensitive drum 401 is transferred onto the sheet by the action of the transfer electric field.

  Thereafter, the sheet on which the toner image is placed is conveyed to the fixing device 407, subjected to fixing processing by the fixing device 407, and then discharged to the subsequent saddle stitch binding device 2. Note that the transfer residual toner remaining on the surface of the photosensitive drum 401 without being transferred to the sheet in the transfer portion is removed by the cleaning device 406.

  FIG. 4 is a diagram for explaining the saddle stitch bookbinding apparatus 2. The saddle stitch bookbinding apparatus 2 receives the sheet bundle SB on which an image is formed and discharged by the image forming apparatus 3, and performs a saddle stitch process and a center folding process on the sheet bundle to create a saddle stitch booklet.

  The saddle stitch bookbinding apparatus 2 includes an entrance conveyance path 241, a sheet-through conveyance path 242, a half-fold conveyance path 243, and the like. An inlet roller pair 201 is provided at the most upstream portion in the sheet conveying direction of the inlet conveying path 241, and the sheet bundle SB discharged from the image forming apparatus 3 is directed into the saddle stitch binding apparatus 2 by the inlet roller pair 201. Transport.

  A branch claw 202 is rotatably provided on the downstream side of the inlet roller pair 201 in the inlet conveyance path 241. The branching claw 202 is installed in the horizontal direction in FIG. 4 and branches the conveyance direction of the sheet bundle SB to the sheet through conveyance path 242 or the half-fold conveyance path 243.

  The sheet-through conveyance path 242 is a conveyance path that extends horizontally from the entrance conveyance path 241 and guides the sheet bundle SB to a discharge tray (not shown) or a subsequent sheet processing apparatus (not shown). Then, the sheet bundle SB conveyed through the sheet through conveyance path 242 is discharged by the upper discharge roller 203 to the discharge tray or the subsequent sheet processing apparatus.

  The middle folding conveyance path 243 is a conveyance path that extends vertically downward from the position of the branch claw 202 and performs a saddle stitching process, a middle folding process, and the like on the sheet bundle SB.

  A folding plate 215 for folding the sheet bundle SB in the middle is provided in the middle folding conveyance path 243. Further, an upper sheet bundle conveyance guide plate 207 that guides the sheet bundle SB above the folding plate 215, a lower sheet bundle conveyance guide plate 208 that guides the sheet bundle SB below the folding plate 215, and the like are also provided.

  The upper sheet bundle conveyance guide plate 207 is provided with an upper sheet bundle conveyance roller 205, a trailing edge hitting claw 221 and a lower sheet bundle conveyance roller 206 in order from the top.

  The rear end tapping claw 221 is erected on a rear end tapping claw driving belt 222 driven by a drive motor (not shown). Then, the rear end tapping claw 221 strikes (presses) the rear end of the sheet bundle SB toward the movable fence described later by the reciprocating rotation operation of the rear end tapping claw driving belt 222, and performs the alignment operation of the sheet bundle SB. Further, when the sheet bundle SB is carried in or when the sheet bundle SB is raised for the middle folding, the sheet bundle SB is retracted from the middle folding conveyance path 243 (a broken line position in FIG. 2).

  The rear end tapping claw home position sensor 294 is for detecting the home position of the rear end tapping claw 221, and indicates the position of the broken line in FIG. 2 (solid line position in FIG. 4) retreated from the center folding conveyance path 243. Detect as home position. The rear end tapping claw 221 is controlled based on this home position.

  The lower sheet bundle conveyance guide plate 208 is provided with a saddle stitch stapler 250, a saddle stitch jogger fence 225, and a movable fence 210 in order from the top.

  The lower sheet bundle conveyance guide plate 208 is a guide plate that receives the sheet bundle SB conveyed through the upper sheet bundle conveyance guide plate 207. A pair of saddle-stitched jogger fences 225 are installed in the width direction of the lower sheet bundle conveyance guide plate 208, and a movable fence 210 that can move up and down is provided below the front end of the sheet bundle.

  The saddle stitching stapler 250 is a binding tool that binds the central portion of the sheet bundle SB. The movable fence 210 moves in the vertical direction with the leading end of the sheet bundle SB in contact with the movable fence 210 and positions the center position of the sheet bundle SB at a position facing the saddle stitching stapler 250. At that position, the binding process, that is, the saddle stitching, is performed on the sheet bundle SB using a binding member such as a staple needle.

  The movable fence 210 is supported by the movable fence drive mechanism 210a, and is movable from the position of the movable fence home position sensor 292 of the movable fence drive mechanism 210a to the lowermost position of the movable fence drive mechanism 210a. .

  The movable range of the movable fence 210 with which the front end of the sheet bundle SB abuts is secured in the range that can be processed from the maximum size that can be processed by the saddle stitch binding apparatus 2 to the minimum size. For example, a rack and pinion mechanism is used as the movable fence drive mechanism 210a.

  Between the upper sheet bundle conveyance guide plate 207 and the lower sheet bundle conveyance guide plate 208, that is, at the substantially central portion of the intermediate folding conveyance path 243, the folding plate 215, the folding roller pair 230, the additional folding roller unit 260, and the lower side A paper discharge roller 231 and the like are provided.

  The additional folding roller unit 260 includes an upper additional folding roller 261a that constitutes an additional folding roller pair 266 that is a pair of rollers across a paper discharge conveyance path between the folding roller pair 230 and the lower paper discharge roller 231. A lower side additional folding roller 262a is provided.

  The folding plate 215 can reciprocate in the horizontal direction in the figure, and the nip of the pair of folding rollers 230 is located on the downstream side in the movement direction when performing the folding operation, and the paper discharge conveyance path 244 is on the extension thereof. Is installed.

  The lower discharge roller 231 is provided on the most downstream side of the discharge conveyance path 244, and discharges the sheet bundle SB that has been folded to the subsequent stage.

  A sheet bundle detection sensor 291 is provided on the lower end side of the upper sheet bundle conveyance guide plate 207, and detects the leading end of the sheet bundle SB that is carried into the middle folding conveyance path 243 and passes the middle folding position. In addition, a crease portion passage sensor 293 is provided in the paper discharge conveyance path 244, and detects the leading end of the folded sheet bundle SB to recognize the passage of the sheet bundle SB.

  In the saddle stitch bookbinding apparatus 2 configured as shown in FIG. 2, the saddle stitching operation and the middle folding operation are performed as shown in the operation explanatory diagrams of FIGS. That is, when the saddle stitching middle folding is selected from the operation panel (not shown) of the image forming apparatus 3, the sheet bundle SB for which the saddle stitching middle folding is selected is rotated by the branching claw 202 in the counterclockwise direction in the drawing. Is guided from the entrance conveyance path 241 to the half-fold conveyance path 243. In this embodiment, the branching claw 202 is driven by a solenoid, but a motor may be used instead of the solenoid.

  The sheet bundle SB carried into the middle folding conveyance path 243 is conveyed downward along the middle folding conveyance path 243 by the inlet roller pair 201 and the upper sheet bundle conveyance roller 205. Then, after the sheet bundle detection sensor 291 confirms the passage of the leading end of the sheet bundle SB, as shown in FIG. 5, the lower sheet bundle conveying roller 206 reaches a position where the leading end of the sheet bundle SB contacts the movable fence 210. Be transported.

  At that time, the movable fence 210 stands by at different stop positions in accordance with the sheet size information from the image forming apparatus 3, here, the size information in the conveying direction of each sheet bundle SB. At this time, in FIG. 5, the lower sheet bundle conveyance roller 206 holds the sheet bundle SB in the nip, and the rear end tapping claw 221 is waiting at the home position.

  In this state, as shown in FIG. 6, the nipping of the lower sheet bundle conveying roller 206 is released (in the direction of arrow a in the figure), the front end of the sheet bundle SB contacts the movable fence 210, and the rear end of the sheet bundle SB is Stacked in a free state. Then, the trailing edge tapping claw 221 is driven, and the rear end of the sheet bundle SB is tapped with the trailing edge tapping claw 221 to finally align the sheet bundle SB in the conveyance direction (the direction of arrow c in the figure).

  Next, the saddle stitching jogger fence 225 performs an alignment operation in the width direction (direction orthogonal to the sheet conveying direction) with respect to the sheet bundle SB. In this way, the alignment operation in the width direction and the conveyance direction is performed on the sheet bundle SB, and the alignment operation in the width direction and the conveyance direction of the sheet bundle SB is completed. At this time, the alignment operation is performed by changing the pushing amount of the trailing edge tapping claw 221 and the saddle stitching jogger fence 225 to the optimum values based on the sheet size information, the number information of the sheet bundle SB, the sheet bundle thickness information, and the like.

  Further, as the thickness of the sheet bundle SB increases, the space in the half-fold conveyance path 243 decreases, and therefore the sheet bundle SB cannot be aligned in a single alignment operation. Therefore, in such a case, the number of alignments of the sheet bundle SB is increased. Thereby, a better alignment state can be realized.

  Note that the standby position of the movable fence 210 is normally set to a position where the saddle stitching position of the sheet bundle SB faces the binding position of the saddle stitching stapler 250. When the sheet bundle SB is aligned at this position, the binding processing can be performed as it is at the position where the sheet bundle SB is stacked in the half-fold conveyance path 243 without moving the movable fence 210 to the saddle stitching position of the sheet bundle SB. Because it becomes. Therefore, by moving the stitcher of the saddle stitching stapler 250 to the central portion of the sheet bundle SB at this standby position in the direction of arrow b in FIG. 6, the binding process by the binding member is performed between the clincher and the sheet bundle SB. Saddle stitched.

  The movable fence 210 is positioned by pulse control from the movable fence home position sensor 292, and the rear end tapping claw 221 is positioned by pulse control from the rear end tapping claw home position sensor 294. Positioning control of the movable fence 210 and the trailing edge tapping claw 221 is executed by a CPU of a control circuit (not shown) of the saddle stitch bookbinding apparatus 2.

  The sheet bundle SB that has been saddle-stitched in the state shown in FIG. 6 is in a state in which saddle-stitching is performed as the movable fence 210 is moved upward in a state in which the holding by the lower sheet bundle conveying roller 206 is released as shown in FIG. Is transferred to a position facing the folding plate 215. This position is also controlled based on the detection position of the movable fence home position sensor 292. The saddle stitching position is a center position in the conveyance direction of the sheet bundle SB.

  When the sheet bundle SB reaches the position shown in FIG. 7, the folding plate 215 moves toward the nip direction of the pair of folding rollers 230 as shown in FIG. Then, they are brought into contact with each other in a substantially right angle direction and pushed out to the nip side of the folding roller pair 230.

  The sheet bundle SB is pushed by the folding plate 215, guided to the nip of the folding roller pair 230, and pushed into the nip of the folding roller pair 230 that has been rotated in advance. The pair of folding rollers 230 conveys the sheet bundle SB pushed into the nip while applying pressure. By this pressurizing and conveying operation, folding is performed at the center of the sheet bundle SB to form a simple bound sheet bundle SB. FIG. 8 shows a state where the tip of the fold part SB1 of the sheet bundle SB is sandwiched and pressed by the nip of the folding roller pair 230.

  In the state shown in FIG. 8, the sheet bundle SB whose center is folded in half is conveyed by the pair of folding rollers 230 as shown in FIG. 9, further conveyed by the lower discharge roller 231, and discharged to the subsequent stage. At this time, when the rear end of the sheet bundle SB is detected by the fold portion passage sensor 293, the folding plate 215 and the movable fence 210 are returned to the home position, and the lower sheet bundle conveying roller 206 is returned to the pressurized state. Prepared for carrying in the sheet bundle SB.

  If the sheet bundle SB of the next job has the same size and the same number, the movable fence 210 may be moved again to the position shown in FIG. These controls are also executed by the CPU of the control circuit.

  Next, features of the saddle stitch bookbinding apparatus 2 provided in the image forming system according to the present embodiment will be described.

  10 is a front view of essential parts of the additional folding roller unit 260 and the pair of folding rollers 230, and FIG. 11 is a side view of the essential parts when FIG. 10 is viewed from the left side in the figure.

  The additional folding roller unit 260 is installed in a paper discharge conveyance path 244 between the pair of folding rollers 230 and the lower paper discharge roller 231, and includes a unit moving mechanism 263, a guide member 264, a pressing mechanism 265, and an additional folding roller pair. 266 and the like.

  The pair of folding rollers 230 has a structure of a dumpling roller in which a plurality of rollers are arranged at intervals in the axial direction.

  The unit moving mechanism 263 reciprocates the additional folding roller unit 260 along the guide member 264 in the depth direction in the drawing (a direction orthogonal to the sheet conveying direction) by a driving source and a driving mechanism (not shown).

  The pressing mechanism 265 includes an additional folding roller upper unit 261 and an additional folding roller lower unit 262. The pressing mechanism 265 applies pressure from above and below by the additional folding roller upper unit 261 and the additional folding roller lower unit 262, and thereby forms the sheet bundle SB. It is a mechanism to press.

  The additional folding roller upper unit 261 is supported by the unit moving mechanism 263 so as to be movable in the vertical direction by a support member 265b. The additional folding roller lower unit 262 is attached to the lower end of the support member 265b of the pressing mechanism 265 so as not to move.

  The upper side folding roller 261a of the upper side folding roller upper unit 261 can be brought into pressure contact with the lower side folding roller 262a of the lower folding roller lower unit 262. Then, the sheet bundle SB is pressed between the nips of the additional folding roller pair 266 including the upper additional folding roller 261a and the lower additional folding roller 262a. The pressing force at this time is applied by a pressurizing spring 265c that pressurizes the additional folding roller upper unit 261 with an elastic force. Then, in a state where the sheet bundle SB is pressurized by the pressing mechanism 265, the sheet bundle SB moves in the width direction (in the direction of arrow D1 in FIG. 11) as will be described later, and additional folding is performed on the fold portion SB1.

  FIG. 12 is a diagram illustrating details of the guide member 264. The guide member 264 includes a guide path 270 that guides the additional folding roller unit 260 in the width direction of the sheet bundle SB. The guide route 270 includes six guide routes: a first guide route 271, a second guide route 272, a third guide route 273, a fourth guide route 274, a fifth guide route 275, and a sixth guide route 276. One route is set.

  The first guide path 271 is a path that guides the pressing mechanism 265 in the pressed release state during forward movement. The second guide path 272 is a path that guides the pressing mechanism 265 in a pressed state during forward movement. The third guide route 273 is a route that switches the pressing mechanism 265 from the release state to the pressed state during forward movement. The fourth guide path 274 is a path that guides the pressing mechanism 265 in the pressed release state during the backward movement. The fifth guide path 275 is a path that guides the pressing mechanism 265 in a pressed state during backward movement. The sixth guide path 276 is a path for switching the pressing mechanism 265 from the pressing release state to the pressing state during the backward movement.

  13 and 14 are enlarged views of the main part of FIG. In addition, the arrow in FIG. 14 has shown the movement locus | trajectory of the guide pin 265a of the press mechanism 265. FIG.

  As shown in FIGS. 13 and 14, the first route switching claw is provided at the intersection of the third guide route 273 and the second guide route 272 and the intersection of the sixth guide route 276 and the fifth guide route 275, respectively. 277 and a second path switching claw 278 are installed.

  The reason why the pressing mechanism 265 moves along the guide path 270 is that the guide pin 265a of the pressing mechanism 265 is movably fitted in the guide path 270 in a loose fit state. That is, the guide path 270 functions as a cam groove and functions as a cam follower that changes its position while the guide pin 265a moves along the cam groove.

  Then, the first route switching claw 277 is pushed down from above by the guide pin 265a of the pressing mechanism 265, so that the guide route is switched from the third guide route 273 to the second guide route 272 as shown in FIG. Move. The second path switching claw 278 rotates so as to switch the guide path from the sixth guide path 276 to the fifth guide path 275 by being pushed down from above by the guide pin 265a of the pressing mechanism 265.

  On the other hand, it is impossible to switch the guide route from the second guide route 272 to the third guide route 273 by the first route switching claw 277, and from the fifth guide route 275 to the sixth guide route 276 by the second route switch claw 278. The guide route cannot be switched. That is, the first route switching claw 277 and the second route switching claw 278 are configured so that the guide route cannot be switched in the reverse direction.

  15 to 25 are operation explanatory views of the additional folding operation by the additional folding roller unit 260 provided in the conventional saddle stitch bookbinding apparatus 2 as a comparative example. In each figure, the first guide route 271, the second guide route 272, the third guide route 273, the fourth guide route 274, the fifth guide route 275, and the sixth guide route 276 provided on the guide route 270 are as follows. FIG. 12 is the same as FIG. 12 and is not shown for easy understanding of the drawing.

  FIG. 15 shows a state in which the sheet bundle SB folded by the folding roller pair 230 is conveyed to a preset additional folding position and stopped, and the additional folding roller unit 260 is in the standby position. This state is the initial position of the additional folding operation.

  From the initial position shown in FIG. 15, the additional folding roller unit 260 starts moving forward in the right direction (arrow D2 direction) as shown in FIG. At that time, the pressing mechanism 265 in the additional folding roller unit 260 moves along the guide path 270 of the guide member 264 by the action of the guide pin 265a, and moves along the first guide path 271 immediately after the operation starts. At this time, the upper side additional folding roller 261a and the lower side additional folding roller 262a are in a pressed release state.

  Here, the “press release state” is a state in which the upper side additional folding roller 261a, the lower side additional folding roller 262a, and the sheet bundle SB are in contact, but almost no pressure is applied to the sheet bundle SB. Alternatively, the upper side additional folding roller 261a, the lower side additional folding roller 262a, and the sheet bundle SB are separated from each other.

  As shown in FIG. 17, when the additional folding roller unit 260 is applied to the third guide path 273 near the center of the sheet bundle SB, the pressing mechanism 265 starts to descend along the third guide path 273 by the action of the guide pin 265a. To do. Then, as shown in FIG. 18, the guide pin 265 a pushes the first path switching claw 277 and enters the second guide path 272. At this time, the pressing mechanism 265 presses the additional folding roller upper unit 261, and the additional folding roller upper unit 261 contacts the sheet bundle SB and is sandwiched between the upper additional folding roller 261a and the lower additional folding roller 262a. The sheet bundle SB is pressed.

  In this state with the sheet bundle SB being pressed, the additional folding roller unit 260 further moves in the direction of arrow D2 in the drawing as shown in FIG. At this time, since the second path switching claw 278 cannot move in the reverse direction, the guide pin 265a of the pressing mechanism 265 moves along the second guide path 272 without being guided by the sixth guide path 276. Then, as shown in FIG. 20, the additional folding roller pair 266 passes through the sheet bundle SB, and the additional folding roller unit 260 is positioned at the final position of the forward movement.

  When the additional folding roller unit 260 moves so far, the guide pin 265a of the pressing mechanism 265 moves from the second guide path 272 to the upper fourth guide path 274. As a result, since the position restriction of the guide pin 265a by the upper surface of the second guide path 272 is released, the upper side additional folding roller 261a is separated from the lower side additional folding roller 262a and is in a pressure released state.

  Next, as shown in FIG. 21, the additional folding roller unit 260 starts the backward movement by the unit moving mechanism 263. In the backward movement, the pressing mechanism 265 moves along the fourth guide path 274 in the left direction (arrow D3 direction) in FIG. When the pressing mechanism 265 reaches the sixth guide path 276 by this movement as shown in FIG. 22, the second path switching claw 278 is pushed downward by the guide pin 265a along the shape of the sixth guide path 276. Then, as shown in FIG. 23, the pressing mechanism 265 shifts from the pressing release state to the pressing state.

  Then, when the additional folding roller unit 260 enters the fifth guide path 275 as shown in FIG. 24, the pressing mechanism 265 is in a complete pressing state, and the fifth guide path 275 is moved in the direction of the arrow D3 in the figure as it is, As shown in FIG. 25, the additional folding roller pair 266 leaves the sheet bundle SB.

  In this way, the additional folding roller unit 260 is reciprocated in the guide path 270, and the additional folding roller pair 266 performs additional folding on the sheet bundle SB. At that time, additional folding from the central portion of the sheet bundle SB to one side in the sheet width direction is started, and the sheet bundle SB passes through one end portion. After that, the sheet is passed through the additionally folded sheet bundle SB, and the additional folding is performed by the operation of starting the additional folding from the center portion of the sheet bundle SB to the other side in the sheet width direction and exiting the other end portion.

  When operated in this way, when the additional folding is started or when one side is pulled out and then returned to the other side, the upper side additional folding roller 261a and the lower side additional folding roller from the outside of the sheet bundle SB to the end of the sheet bundle SB. 262a does not contact or pressurize. In other words, when the additional folding roller pair 266 passes through the end portion of the sheet bundle SB from the outside of the end portion, the pressing mechanism 265 is in the pressed release state. Therefore, damage to the end portion of the sheet bundle SB does not occur.

  Further, since the sheet bundle SB is further folded from near the center to the end, the pair of additional folding rollers 266 travels in contact with the sheet bundle SB at the time of folding, which may cause wrinkles and the like. Are also difficult to accumulate. Therefore, when the fold of the sheet bundle SB is increased and folded, the end portion of the sheet bundle SB is not damaged, and it is possible to suppress the occurrence of the crease due to the accumulation of wrinkles and the wrinkles and wrinkles in the vicinity thereof.

  In the additional folding roller unit 260 in the present embodiment, the additional folding roller lower unit 262 is provided, and the sheet bundle SB is sandwiched by the additional folding roller pair 266 including the upper additional folding roller 261a and the lower additional folding roller 262a, and further folding is performed. It is carried out. On the other hand, the lower folding roller lower unit 262 is not provided, but the additional folding roller upper unit 261 and a receiving member (not shown) having a contact surface facing the upper folding roller are provided so as to press the sheet bundle SB therebetween. You may comprise.

  Further, in the additional folding roller unit 260 in the present embodiment, the additional folding roller upper unit 261 is configured to be movable in the vertical direction, and the additional folding roller lower unit 262 is configured to be immovable in the vertical direction. It is not a thing. That is, the additional folding roller lower unit 262 can also be configured to be movable in the vertical direction. If comprised in this way, the upper side additional folding roller 261a and the lower side additional folding roller 262a will contact / separate symmetrically at equal intervals with respect to the additional folding position. For this reason, the additional folding position is constant regardless of the thickness of the sheet bundle SB, and damage to the sheet bundle SB such as scratches can be suppressed.

  In the saddle stitch bookbinding apparatus 2 of the present embodiment, as shown in FIG. 1, two binding members 50a binding the sheet bundle SB to the second guide path 272 and the fifth guide path 275 of the guide member 264, respectively. Corresponding to 50b, notches 264a and 264b are provided.

  26 to 36 are operation explanatory views of the additional folding operation by the additional folding roller unit 260 provided in the saddle stitch bookbinding apparatus 2 according to the present embodiment. In each figure, the first guide route 271, the second guide route 272, the third guide route 273, the fourth guide route 274, the fifth guide route 275, and the sixth guide route 276 provided on the guide route 270 are as follows. FIG. 12 is the same as FIG. 12 and is not shown for easy understanding of the drawing.

  FIG. 26 shows a state in which the sheet bundle SB folded by the folding roller pair 230 is conveyed to a preset additional folding position and stopped, and the additional folding roller unit 260 is in the standby position. This state is the initial position of the additional folding operation.

  From the initial position shown in FIG. 26, the additional folding roller unit 260 starts moving forward in the right direction (arrow D2 direction) as shown in FIG. At that time, the pressing mechanism 265 in the additional folding roller unit 260 moves along the guide path 270 of the guide member 264 by the action of the guide pin 265a, and moves along the first guide path 271 immediately after the operation starts. At this time, the upper side additional folding roller 261a and the lower side additional folding roller 262a are in a pressed release state.

  As shown in FIG. 28, when the additional folding roller unit 260 is applied to the third guide path 273 near the center of the sheet bundle SB, the pressing mechanism 265 starts to descend along the third guide path 273 by the action of the guide pin 265a. To do. Then, the first route switching claw 277 is pushed away to enter the second guide route 272 as shown in FIG.

  At this time, the pressing mechanism 265 presses the additional folding roller upper unit 261, and the additional folding roller upper unit 261 contacts the sheet bundle SB and is sandwiched between the upper additional folding roller 261a and the lower additional folding roller 262a. The sheet bundle SB is pressed.

  In this state with the sheet bundle SB being pressed, the additional folding roller unit 260 further moves in the direction of arrow D2 in the drawing as shown in FIG. At this time, since the second path switching claw 278 cannot move in the reverse direction, the guide pin 265a of the pressing mechanism 265 moves along the second guide path 272 without being guided by the sixth guide path 276.

  Then, when the guide pin 265a of the pressing mechanism 265 reaches the notch 264a provided in the second guide path 272 of the guide member 264, the guide pin 265a is displaced upward and the pressure spring 265c is extended to be further upwardly folded. The biasing force that biases the roller 261a is weakened.

  As a result, the pressing force for pressing the fold of the sheet bundle SB by the upper side additional folding roller 261a is weakened near the binding member 50a of the sheet bundle SB. Accordingly, the force applied to the binding member 50a is reduced accordingly, and the binding member 50a can be prevented from being deformed by being pushed by the upper side additional folding roller 261a by the additional folding operation by the additional folding roller pair 266. Further, it is possible to suppress the upper side additional folding roller 261a and the lower side additional folding roller 262a from being damaged by the binding member 50a.

  Thereafter, when the guide pin 265a of the pressing mechanism 265 passes through the notch 264a, the guide pin 265a is pressed downward by the guide member 264, and the pressure spring 265c is compressed, and the upper side additional folding roller 261a is urged. Energizing power increases. As a result, the pressing force pressing the fold of the sheet bundle SB by the upper side additional folding roller 261a is increased again, and the additional folding is strengthened.

  Thereafter, as shown in FIG. 31, the additional folding roller pair 266 exits the sheet bundle SB, and the additional folding roller unit 260 is positioned at the final position of the forward movement.

  When the additional folding roller unit 260 moves so far, the guide pin 265a of the pressing mechanism 265 moves from the second guide path 272 to the upper fourth guide path 274. As a result, since the position restriction of the guide pin 265a by the upper surface of the second guide path 272 is released, the upper side additional folding roller 261a is separated from the lower side additional folding roller 262a and is in a pressure released state.

  Next, as shown in FIG. 32, the additional folding roller unit 260 starts the backward movement by the unit moving mechanism 263. In the backward movement, the pressing mechanism 265 moves along the fourth guide path 274 in the left direction (arrow D3 direction) in FIG. When the pressing mechanism 265 reaches the sixth guide path 276 by this movement as shown in FIG. 33, the second path switching claw 278 is pressed downward by the guide pin 265a along the shape of the sixth guide path 276. Then, as shown in FIG. 34, the pressing mechanism 265 shifts from the pressing release state to the pressing state.

  Then, as shown in FIG. 35, when the additional folding roller unit 260 enters the fifth guide path 275, the pressing mechanism 265 enters a complete pressing state, and moves along the fifth guide path 275 in the direction of arrow D3 in the drawing.

  At this time, since the first path switching claw 277 cannot move in the reverse direction, the guide pin 265a of the pressing mechanism 265 moves along the fifth guide path 275 without being guided by the third guide path 273.

  Then, when the guide pin 265a of the pressing mechanism 265 reaches the notch 264b provided in the fifth guide path 275 of the guide member 264, the guide pin 265a is displaced upward and the pressure spring 265c is extended to be further upwardly folded. The biasing force that biases the roller 261a is weakened.

  As a result, the pressing force for pressing the fold of the sheet bundle SB by the upper side additional folding roller 261a is weakened in the vicinity of the binding member 50b of the sheet bundle SB. Therefore, the force applied to the binding member 50b is reduced correspondingly, and the binding member 50b can be prevented from being deformed by being pushed by the upper side additional folding roller 261a by the additional folding operation by the additional folding roller pair 266. Further, it is possible to suppress the upper side additional folding roller 261a and the lower side additional folding roller 262a from being damaged by the binding member 50b.

  Thereafter, when the guide pin 265a of the pressing mechanism 265 passes through the notch 264b, the guide pin 265a is displaced downward by the guide member 264, the pressure spring 265c is compressed, and the upper additional folding roller 261a is urged. Energizing power increases. As a result, the pressing force pressing the fold of the sheet bundle SB by the upper side additional folding roller 261a is increased again, and the additional folding by the additional folding roller pair 266 is strengthened.

  Thereafter, as shown in FIG. 36, the additional folding roller pair 266 passes through the sheet bundle SB, the additional folding roller unit 260 reaches the initial position, and the additional folding operation is finished.

  As described above, in the present embodiment, when the additional folding roller pair 266 passes through a portion where the binding members 50a and 50b pass, the upper side additional folding roller 261a is more than just before it passes through a portion where the binding members 50a and 50b pass. Decrease the urging force that presses the crease. Accordingly, the force applied to the binding members 50a and 50b is weakened with an urging force strong enough to obtain a sufficient additional folding effect as compared with the case where the upper additional folding roller 261a is always pressed against the fold to perform additional folding. Can do. Therefore, it is possible to prevent the binding members 50a and 50b from being pushed by the upper side additional folding roller 261a and deformed by the additional folding operation by the additional folding roller pair 260.

  Further, the biasing force from the pressure spring 265c is weakened only when the additional folding roller pair 266 passes through a portion where the binding members 50a and 50b are present. As a result, it is possible to secure an additional folding effect as compared with the case where the upper folding roller 261a is always pressed against the fold and the additional folding is performed with a weak urging force capable of suppressing the deformation of the binding members 50a and 50b. .

  In the present embodiment, the upper side additional folding roller 261a is completely separated from the sheet bundle SB at the position of the binding members 50a and 50b, but is not limited thereto. That is, the notch portions 264a and 264b may be provided on the guide member 264 so that the upper side additional folding roller 261a contacts the sheet bundle SB with a pressing force weaker than a normal pressing force at the binding members 50a and 50b. good.

  In the present embodiment, the widths of the notches 264a and 264b in the sheet width direction are made larger than the widths of the binding members 50a and 50b in the sheet width direction. Thereby, even if the position of the sheet bundle SB is shifted in the sheet width direction, deformation of the binding members 50a and 50b and damage to the upper side additional folding roller 261a and the lower side additional folding roller 262a can be suppressed.

  FIG. 37 is an explanatory diagram of points regarding speed control of the additional folding roller unit 260 (the additional folding roller pair 266).

  The additional folding roller unit 260 (the additional folding roller pair 266) starts moving at a speed V0 from a state where the guide pin 265a of the pressing mechanism 265 is positioned at the position P0 which is the initial position. When the guide pin 265a reaches a position near the position P1 located on the upstream side in the moving direction of the folding roller unit with respect to the notch 264a in the second guide path 272, the moving speed of the additional folding roller unit 260 is a speed satisfying V1 <V0. Decelerate to V1 and pass through the notch 264a.

  When the guide pin 265a reaches the position P2 immediately after passing through the notch 264a in the second guide path 272, the moving speed of the additional folding roller unit 260 is returned to the speed V0 and moved to the final position of the forward movement. .

  After reaching the final position of the forward movement, the additional folding roller unit 260 is temporarily stopped and further folded at a speed V0 toward the initial position through the fourth guide path 274, the sixth guide path 276, and the fifth guide path 275. The movement of the roller unit 260 is started.

  When the guide pin 265a reaches a position near the position P3 that is further upstream than the notch 264b in the fifth guide path 275 and is located upstream of the folding roller unit moving direction, the speed is reduced to a speed V1 of V1 <V0 and the notch 264b. Pass through.

  When the guide pin 265a reaches the position P4 immediately after passing through the notch 264b in the fifth guide path 275, the moving speed of the additional folding roller unit 260 is returned to V0, moved to the initial position, and stopped.

  As described above, in the saddle stitch bookbinding apparatus 2 of the present embodiment, the moving speed of the additional folding roller unit 260 is changed between when the notches 264a and 264b provided on the guide member 264 are guide pins 265a and before and after the guide pins 265a. This control can be executed.

  That is, immediately before the guide pin 265a of the pressing mechanism 265 passes through the notches 264a and 264b, the moving speed of the additional folding roller unit 260 is changed to a speed V1 slower than the speed V0 and passes through the notches 264a and 264b. Let Thereby, when the guide pin 265a enters or exits the notches 264a and 264b, it is possible to mitigate the impact generated in the notches 264a and 264b. For this reason, when, for example, a stepping motor is used as the drive source of the unit moving mechanism 263, it is possible to suppress motor stop due to step-out.

  Further, after the guide pin 265a passes through the notches 264a and 264b, the moving speed of the additional folding roller unit 260 is returned from the speed V1 to the speed V0. Accordingly, it is possible to keep the additional folding roller unit 260 from being moved at a slow speed (speed V1) when passing through the cutout, and to prevent the time required for the additional folding process from becoming long.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
Folding means such as a pair of folding rollers 230 that sandwich the sheet bundle and fold the sheet bundle with the vicinity of the binding portion bound by the binding members such as the binding members 50a and 50b of the sheet bundle such as the sheet bundle SB. And a pair of roller members such as an upper additional folding roller 261a and a lower additional folding roller 262a having an axis perpendicular to the sheet width direction are arranged so as to sandwich the sheet bundle folded by the folding means. The roller member is applied with an urging force that presses at least one roller member of the additional fold roller pair such as the additional fold roller pair 266 that further folds the fold of the sheet bundle while moving in the sheet width direction, and the additional fold roller pair. In a sheet processing apparatus such as the saddle stitch bookbinding apparatus 2 provided with an urging means such as a pressing mechanism 265, the additional folding roller pair A guide pin 265a or a guide member that moves in the width direction and changes the urging force when passing the portion with the binding member so as to be weaker than the urging force when passing the portion without the binding member. And urging force changing means including H.264.
In (Aspect A), when the pair of additional folding rollers moves through the fold of the sheet bundle and passes through a portion having the binding member, the rollers of the additional folding roller pair are more than when passing through the portion without the binding member. The biasing force that presses the member into the crease is weakened by the biasing force changing means. As a result, the force applied to the binding member can be weakened with an urging force strong enough to obtain a sufficient additional folding effect, as compared with the case where the roller member is always pressed against the crease to perform additional folding. Therefore, it is possible to suppress the binding member from being pushed and deformed by the roller member by the additional folding operation by the additional folding roller pair.
Further, by weakening the biasing force only when the pair of additional folding rollers passes through a portion of the binding member, the roller member is always pressed against the crease with a weak biasing force that can suppress deformation of the binding member. The additional folding effect can be ensured as compared with the case of folding.
(Aspect B)
In (Aspect A), the urging means includes a spring member such as a pressure spring 265c, and the urging force changing means is displaceable in a direction in which the roller member is pressed against the fold by the spring member. A guide member such as a guide member 264 that contacts a displacement member such as a pressing mechanism 265 that expands or contracts the member and a guided portion such as a guide pin 265a provided on the displacement member and guides the movement of the guided member in the sheet width direction. The guide member is provided with recesses such as notches 264a and 264b so as to correspond to the position of the binding member in the sheet width direction in the sheet bundle. According to this, as described in the above embodiment, when the guided portion reaches the concave portion of the guide member, the spring member is extended to reduce the biasing force and weaken the pressing of the binding member of the sheet bundle by the roller member. be able to.
(Aspect C)
In (Aspect B), it is preferable that the sheet bundle is bound by a plurality of binding members, and the guide member is provided with a plurality of the concave portions corresponding to the plurality of binding members.
(Aspect D)
In (Aspect B) or (Aspect C), the width of the concave portion in the sheet width direction is larger than the width of the binding member in the sheet width direction. According to this, as described in the above embodiment, even when the position of the sheet bundle is shifted in the sheet width direction, deformation of the binding member and damage to the roller member can be suppressed.
(Aspect E)
In (Aspect B), (Aspect C) or (Aspect D), when the additional folding roller pair is moved in the sheet width direction, the moving speed of the additional folding roller pair when the guided portion passes through the recess. Is made slower than before the guided portion passes through the recess. According to this, as described in the above embodiment, it is possible to mitigate the impact that occurs when the guided portion enters or exits the recess.
(Aspect F)
In (Espect E), when the additional folding roller pair is moved in the sheet width direction, after the guided portion passes through the concave portion, the moving speed of the additional folding roller pair is measured before the guided portion passes through the concave portion. Return to speed. According to this, as described in the above embodiment, it is possible to continue to move the additional folding roller pair as it is at a slow speed when the guided portion passes through the recess, and to increase the time required for the additional folding process. Can be suppressed.
(Aspect G)
In an image forming system including an image forming apparatus that forms an image on a sheet and a sheet processing apparatus that performs a predetermined process on a sheet on which an image is formed by the image forming apparatus, the sheet processing apparatus includes: The sheet processing apparatus of Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E) or (Aspect F) was used. According to this, as described in the above embodiment, it is possible to perform good image formation while suppressing deformation of the binding member and damage to the additional folding roller.

2 Saddle-stitch bookbinding apparatus 3 Image forming apparatus 4 Image forming system 50a Binding member 50b Binding member 100 Image reading apparatus 201 Entrance roller pair 202 Branch claw 203 Upper sheet discharge roller 205 Upper sheet bundle conveying roller 206 Lower sheet bundle conveying roller 207 Upper Sheet bundle conveyance guide plate 208 Lower sheet bundle conveyance guide plate 210 Movable fence 210a Movable fence drive mechanism 215 Folding plate 221 Rear end tapping claw 222 Rear end tapping claw drive belt 225 Saddle stitching jogger fence 230 Folding roller pair 231 Lower paper discharge Roller 241 Entrance conveyance path 242 Sheet through conveyance path 243 Middle folding conveyance path 244 Discharge conveyance path 250 Saddle stitching stapler 260 Additional folding roller unit 261 Additional folding roller upper unit 261a Upper additional folding roller 262 Additional folding Lower unit 262a Lower side additional folding roller 263 Unit moving mechanism 264 Guide member 264a Notch portion 264b Notch portion 265 Press mechanism 265a Guide pin 265b Support member 265c Pressure spring 266 Additional folding roller pair 270 Guide path 271 First guide Route 272 second guide route 273 third guide route 274 fourth guide route 275 fifth guide route 276 sixth guide route 277 first route switching claw 278 second route switching claw 291 sheet bundle detection sensor 292 movable fence home position sensor 293 Folding section passage sensor 294 Rear end tapping claw home position sensor 301 Light source 302 Mirror 303 First traveling body 304 Mirror 305 Mirror 306 Second traveling body 307 Lens 309 Platen glass 400 Image forming apparatus Body 401 Photosensitive drum 402 Charging device 404 Developing device 405 Transfer device 406 Cleaning device 407 Fixing device 410 Exposure device 411 Laser unit 412 Polygon mirror 413 Registration roller pair 414a Feeding roller 414b Feeding roller 500 Automatic document feeder 501 Document table 502 Document separation feed roller 503 Conveyor belt 504 Document discharge tray

JP 2012-20882 A

Claims (7)

Folding means for sandwiching the sheet bundle and folding the sheet bundle with the vicinity of the binding portion bound by the binding member of the sheet bundle as a folding position;
A pair of roller members having axes perpendicular to the sheet width direction are arranged so as to sandwich the sheet bundle folded by the folding means, and the folds of the sheet bundle are increased and folded while moving in the sheet width direction. A pair of additional folding rollers
In a sheet processing apparatus comprising: a biasing unit that applies a biasing force that presses at least one roller member of the additional folding roller pair to the fold;
The additional folding roller pair moves in the sheet width direction so that the urging force when passing through the portion with the binding member is weaker than the urging force when passing through the portion without the binding member. A sheet processing apparatus comprising an urging force changing means for changing. The sheet processing apparatus according to claim 1, wherein
The biasing means has a spring member,
The biasing force changing means is displaceable in a direction in which the roller member is pressed against the crease by the spring member, contacts a guided member provided on the displaced member, and a guided member provided on the displaced member. A guide member for guiding the movement of the portion in the sheet width direction,
A sheet processing apparatus, wherein a recess is provided in the guide member so as to correspond to a position in the sheet width direction of the binding member in the sheet bundle. The sheet processing apparatus according to claim 2, wherein
The sheet processing apparatus, wherein the sheet bundle is bound by a plurality of binding members in a sheet width direction, and the guide member is provided with a plurality of the concave portions corresponding to the plurality of binding members. The sheet processing apparatus according to claim 2 or 3,
The width of the concave portion in the sheet width direction is larger than the width of the binding member in the sheet width direction. The sheet processing apparatus according to claim 2, 3 or 4,
When moving the additional folding roller pair in the sheet width direction, when the guided portion passes through the recess, the moving speed of the additional folding roller pair is slower than before the guided portion passes through the recess. A sheet processing apparatus. The sheet processing apparatus according to claim 5, wherein
When the additional folding roller pair is moved in the sheet width direction, after the guided portion passes through the concave portion, the moving speed of the additional folding roller pair is returned to the speed before the guided portion passes through the concave portion. A sheet processing apparatus. An image forming apparatus for forming an image on a sheet;
In an image forming system comprising a sheet processing apparatus that performs a predetermined process on a sheet on which an image is formed by the image forming apparatus,
7. An image forming system using the sheet processing apparatus according to claim 1, 2, 3, 4, 5, or 6 as the sheet processing apparatus.

Images