JP5564976B2 - Paper post-processing device - Google Patents

Description

  The present invention relates to a sheet post-processing apparatus that stacks sheets ejected from an image forming apparatus such as a copying machine or a printer, performs saddle stitching on the stacked sheet bundle, and performs folding processing at a saddle stitching position.

  Conventionally, a plurality of sheets discharged from an image forming apparatus such as a copying machine or a printer are stacked and aligned on a staple tray, and the intermediate position in the transport direction of the aligned sheet bundle is bound by a staple unit (saddle stitching). In this case, a sheet post-processing apparatus is known in which a saddle-stitched sheet bundle is folded and bound at the saddle-stitching position, and is discharged as a booklet. In this type of paper post-processing apparatus, even when the number of paper sheets constituting the paper bundle is large, an appropriate folding process is performed so that the booklet that has been bound does not bulge and a good finished state can be obtained. Various techniques for appropriately folding the sheet bundle at the saddle stitching position have been studied.

  For example, in Patent Document 1, a push-blade pushes the saddle stitching position of a bundle of paper until it abuts against a stopper plate, and then lowers a pair of press blades disposed obliquely on both sides of the push blade, and the pair of presses A technique is disclosed in which folding is performed so that the booklet does not bulge by being pressed while sandwiching both sides of the saddle stitching position of the sheet bundle with the tip of the blade and squeezing downward.

  In Patent Document 2, a folding blade is applied to a saddle stitching position of a bundle of sheets to make a crease, and then the bundle of sheets is drawn with the saddle stitching position creased by a pair of rollers (pre-press rollers) as the head. In addition, a technique is disclosed in which folding is performed so that the booklet does not bulge by being temporarily folded and then transported while being sandwiched between a pair of rollers (press rollers).

JP 2004-210436 A JP 2000-143081 A

  However, in the technique disclosed in Patent Document 1, since the sheet bundle is pressed while squeezing it with the tip of the press blade, the surface of the sheet bundle may be damaged. Further, there is a problem that wrinkles occur near the saddle stitching position of the sheet bundle and a good finished state cannot be obtained.

  In the technique disclosed in Patent Document 2, folding is performed by conveying a temporarily folded sheet bundle while being sandwiched between a pair of rollers, so that generation of scratches and wrinkles is suppressed. However, a roller (press roller) that performs such a folding process is an expensive part, and thus there is a problem that the cost is increased.

  The present invention has been made in view of the above, and provides a sheet post-processing apparatus capable of appropriately folding a sheet bundle without causing scratches or wrinkles without causing an increase in cost. It is an object.

In order to solve the above-described problems and achieve the object, a sheet post-processing apparatus according to the present invention is aligned by an alignment tray that stacks and aligns a plurality of sheets discharged from an image forming apparatus, and the alignment tray. A binding unit that performs a saddle stitching process on the sheet bundle, a folding blade that folds the saddle stitching position of the sheet bundle that is saddle-stitched by the binding unit, and a saddle stitching position that is folded by the folding blade. Conveying means for conveying the sheet bundle starting from the top, a pair of folding plates sandwiching the saddle stitching position of the sheet bundle conveyed by the conveying means, and pressurizing one of the pair of folding plates to the other side and means, wherein the pressurizing means, which are connected via one pressure member of the pair of folding plates, and the press axis direction and axial direction intersecting the pressing direction, of the press shaft Comprising a guide member for restricting the movement direction, the crank plate to rotate by a motor, coupled to the position where one end is eccentric of the crank plate, and a crank rod which has the other end coupled to the press axis, wherein the The press shaft passes through the guide member, and the pressure member and one folding plate connected to the pressure member are disposed on one side of the guide member in the axial direction, and the guide member in the axial direction is disposed. The crank rod connected to the crank rod and the crank plate connected to the crank rod are disposed on the other side, the rotation of the crank plate is converted into a linear motion of the crank rod, and the press shaft connected to the crank rod is guided to the guide By moving to one side of the pair of folding plates along the member, one of the pair of folding plates is moved by the pressure member. The pressurizing the other side, characterized by.

  According to the present invention, the saddle stitching position of the sheet bundle is sandwiched between a pair of inexpensive folding plates as parts, and the folding process is performed on the sheet bundle by pressing one folding plate to the other side by the pressing means. Therefore, there is an effect that the folding can be appropriately performed without causing an increase in cost and without causing scratches and wrinkles on the sheet bundle.

FIG. 1 is a schematic configuration diagram of a sheet post-processing apparatus. FIG. 2 is a perspective view showing a mechanism for moving the folding blade. FIG. 3 is a schematic diagram illustrating a configuration of a press unit exemplified in the first embodiment. FIG. 4 is a perspective view showing a mechanism for rotationally driving the folding plate moving crank plate. FIG. 5 is a perspective view illustrating a configuration of a press unit exemplified in the first embodiment. FIG. 6 is a schematic diagram illustrating a configuration of a press unit exemplified in the second embodiment. FIG. 7 is a perspective view illustrating a configuration of a press unit exemplified in the second embodiment. FIG. 8 is a schematic diagram illustrating a configuration of a press unit exemplified in the third embodiment.

  Exemplary embodiments of a sheet post-processing apparatus according to the present invention will be explained below in detail with reference to the accompanying drawings. In addition, the following embodiment shows an example of application of the present invention by way of example, and the present invention is not limited to this embodiment. In addition, the constituent elements of the embodiments described below can be appropriately changed to those that can be easily replaced by those skilled in the art or substantially the same.

(First embodiment)
FIG. 1 is a schematic configuration diagram of a sheet post-processing apparatus FR according to the present embodiment. This sheet post-processing apparatus FR performs post-processing on a recorded sheet discharged from an image forming apparatus PR such as a copying machine or a printer, and is disposed adjacent to the image forming apparatus PR. .

  Inside the paper post-processing apparatus FR, there are provided an entrance conveyance path A, an upper conveyance path B, an intermediate conveyance path C, and a lower conveyance path D. The entrance conveyance path A is a conveyance path that receives a sheet discharged from the image forming apparatus PR. The upper transport path B is a transport path that guides the paper that has passed through the entrance transport path A to the proof tray 18. The intermediate transport path C is a transport path that guides the paper that has passed through the entrance transport path A to the paper discharge tray 17 after being moved a certain amount in a direction perpendicular to the transport direction. The lower transport path D is a transport path that guides the paper that has passed through the entrance transport path A to the staple tray (alignment tray) 10. The sorting of the paper from the entrance conveyance path A to the upper conveyance path B, the intermediate conveyance path C, and the lower conveyance path D is performed by the operation of the branch claw 24 and the turn guide 36 and the branch claw 25 and the turn guide 37.

  An entrance sensor 301 that detects a sheet received from the image forming apparatus PR is provided in the entrance transport path A that is located upstream of each of the transport paths B, C, and D. The punch unit 3, the transport roller 31, the branching claw 24, and the turn guide 36 are sequentially arranged on the downstream side. Further, on the further downstream side of the branching claw 24 and the turn guide 36, the conveying roller 32, the branching claw 25, and the turn guide 37 are sequentially arranged.

  The sheet received from the image forming apparatus PR to the entrance conveyance path A of the sheet post-processing apparatus FR is punched at a predetermined position by the punch unit 3 as necessary, and is conveyed downstream by the conveyance roller 31. The branching claw 24 is held at the position of the solid line in FIG. 1 by a spring (not shown), and is turned to the position of the one-dot chain line in FIG. 1 by turning on the solenoid (not shown). When the solenoid is OFF and the branching claw 24 is at the position of the solid line in FIG. 1, the sheet is guided to the upper conveyance path B. On the other hand, when the solenoid is turned on and the branching claw 24 rotates to the position of the one-dot chain line in FIG. 1, the sheet is guided to the intermediate conveyance path C and the lower conveyance path D, and further downstream by the conveyance roller 32. It is conveyed.

  Further, the branch claw 25 is held at the position of the solid line in FIG. 1 by a spring (not shown), and is turned to the position of the one-dot chain line in FIG. 1 by turning on the solenoid (not shown). When the solenoid is OFF and the branching claw 25 is at the position of the solid line in FIG. 1, the sheet is guided to the lower conveyance path D. On the other hand, when the solenoid is turned on and the branching claw 25 rotates to the position of the one-dot chain line in FIG. 1, the sheet is guided to the intermediate conveyance path C.

  A proof paper discharge roller 7 is disposed in the upper conveyance path B. The sheet guided from the entrance conveyance path A to the upper conveyance path B is discharged to the proof tray 18 by the proof discharge roller 7 and stacked on the proof tray 18.

  A shift roller 9 and a discharge roller 15 are sequentially arranged in the intermediate conveyance path C. The sheet guided from the entrance conveyance path A to the intermediate conveyance path C through the conveyance roller 32 and the turn guide 37 moves by a certain amount in the direction perpendicular to the conveyance direction by the action of the shift roller 9, and is discharged in that state. The paper is discharged to the paper discharge tray 17 by the rollers 15 and stacked on the paper discharge tray 17. The timing at which the shift roller 9 moves the paper is determined based on paper detection information by the entrance sensor 301, paper size information, and the like.

  In the lower conveyance path D, a staple tray discharge sensor 302 is provided. The sheet detection information by the staple tray discharge sensor 302 is used as a trigger when the sheet in the lower conveyance path D is confirmed, the sheet is discharged to the staple tray 10 and an alignment operation is performed. In the lower conveyance path D, conveyance rollers 33, 34, and 35 are sequentially arranged. The paper guided from the entrance transport path A to the lower transport path D through the transport roller 32 and the turn guide 37 is sequentially transported to the downstream side by the transport rollers 33, 34, and 35 and stacked on the staple tray 10. The staple tray 10 stacks and aligns a plurality of sheets.

  The sheets stacked on the staple tray 10 are aligned on the staple tray 10 in a direction perpendicular to the conveyance direction by the jogger fence 12, and the conveyance direction is a trailing end that is a sheet abutting member by the action of the tapping roller 8. The fence 27 is used as a reference. Thereafter, the staple unit 5 performs a binding process on the bundle of sheets aligned on the staple tray 10. Here, in the case of performing edge binding, the staple unit 5 performs binding processing on the bundle of sheets stacked on the staple tray 10. Then, the edge-bound paper bundle is conveyed upward by the discharge claw 11 attached to the discharge belt 14, and discharged and stacked on the discharge tray 17 by the discharge roller 15. Note that a paper surface detection sensor 303 for detecting the paper surface height of the paper loaded on the paper discharge tray 17 is provided at the exit to the paper discharge tray 17, and the paper surface height of the paper loaded on the paper discharge tray 17 is provided. Accordingly, the height position of the paper discharge tray 17 can be adjusted.

  On the other hand, when performing saddle stitching, one of the bundle conveying rollers 13a and 13b moves from the position of the solid line in FIG. A bundle of sheets aligned on the staple tray 10 is sandwiched between the bundle conveying rollers 13a and 13b so that the sheet can be conveyed. Thereafter, the trailing edge fence 27 is retracted, and the sheet bundle is conveyed downward by the bundle conveying rollers 13a and 13b in an unbound state. When the intermediate position in the conveyance direction of the sheet bundle reaches the binding position of the staple unit 5, conveyance of the sheet bundle by the bundle conveyance rollers 13a and 13b is stopped, and the staple needle is driven into the sheet bundle by the staple unit 5 ( Saddle stitching process).

  The staple unit (binding means) 5 includes a driver unit 5a that drives out a binding needle and a clincher unit 5b that bends the leading end of the binding needle that has been driven into a sheet bundle. In the staple unit 5 in the present embodiment, the driver unit 5a and the clincher unit 5b are configured separately, and can be moved in the direction perpendicular to the sheet bundle conveyance direction by the stapler moving guide 6, and the driver unit 5a and the clincher are configured. The part 5b includes a relative positioning mechanism and a moving mechanism (not shown).

  When the saddle stitching process by the staple unit 5 is completed, one of the bundle conveying rollers 26a and 26b moves from the position of the solid line in FIG. 1 to the position of the one-dot chain line to apply pressure to the sheet bundle. Then, the saddle-stitched sheet bundle is nipped by the bundle conveying rollers 26a and 26b so that the sheet can be conveyed. After that, one of the bundle conveying rollers 13a and 13b moves to the position indicated by the solid line in FIG. 1 to release the nipping of the sheet bundle by the bundle conveying rollers 13a and 13b, and the saddle-stitched sheet bundle. Is conveyed downward by the bundle conveying rollers 26a and 26b. When the intermediate position (saddle stitching position) in the transport direction of the sheet bundle reaches the crease position by the folding blade 19, the transport of the sheet bundle by the bundle transport rollers 26 a and 26 b is stopped, and the saddle stitching position by the folding blade 19 is reached. A crease process is performed.

  As shown in FIG. 2, the folding blade 19 is tapered at the distal end side and provided with a shaft at the proximal end side, and both ends of the shaft of the folding blade 19 are fixed inside the paper post-processing apparatus FR. It is connected to the folding blade moving crank rod 122 through a folding blade guide 121 provided in the above manner. The folding blade movement crank rod 122 is connected to the folding blade crank drive motor 125 via the folding blade movement crank plates 126 and the crankshaft drive large gear 124 at both ends of the folding blade crankshaft 123.

  In the above configuration, the folding blade crank drive motor 125 is driven to rotate by one turn of the folding blade moving crank plate 126 when the saddle stitched sheet bundle is conveyed to the crease position by the bundle conveying rollers 26a and 26b. Is done. When the folding blade crank drive motor 125 rotates, the rotation of the folding blade crank drive motor 125 is transmitted to the folding blade movement crank plate 126, and the rotation of the folding blade movement crank plate 126 becomes the linear motion of the folding blade movement crank rod 122. Converted. When the folding blade moving crank rod 122 moves linearly, the folding blade 19 connected to the folding blade moving crank rod 122 linearly moves while the moving direction is regulated by the folding blade guide 121, and the tip end side of the tapered shape is moved. The sheet bundle is abutted against the saddle stitching position to make a crease, and then driven to retract from the sheet bundle.

  The sheet bundle having the crease at the saddle stitching position by the folding blade 19 is transported to the press unit by the transport roller 38 in a state of being folded in two so that the saddle stitching position is at the head.

  The press unit sandwiches the saddle stitching position of the sheet bundle conveyed by the conveying roller 38 with a pair of upper and lower folding plates 20a and 20b, and in this state, the pressing mechanism (pressurizing means) 21 holds one folding plate 20a to the other. The sheet bundle is folded by applying pressure to the folding plate 20b side.

  A specific example of the press unit is shown in FIGS. The press unit exemplified in this embodiment includes a pair of flat plates 20a and 20b made of a metal plate or a synthetic resin plate having a predetermined rigidity. As shown in FIG. 3, the pair of folding plates 20 a and 20 b are opposed to each other so that the main surface portions are attached to each other with a predetermined interval. Of the pair of folding plates 20a and 20b, one folding plate 20a is connected to the pressurizing mechanism 21, and the other folding plate 20b is fixed inside the sheet post-processing apparatus FR. In addition, it is preferable that surface treatment processing for reducing friction with the sheet bundle S is performed on the opposing main surface portions of the pair of folding plates 20a and 20b.

  The pressurizing mechanism 21 connected to the folding plate 20a converts the rotation of the folding plate moving crank plate 134 into a linear motion of the folding plate moving crank rod 135, and folds the press shaft 133a connected to the folding plate moving crank rod 135. It is lowered along the plate guide 136 toward the folding plate 20a. And it is the structure which presses the folding plate 20a to the folding plate 20b side by making urging | biasing force act on press pressurization members 133b, such as a compression spring connected with the press shaft 133a, by the fall of the press shaft 133a.

  As shown in FIG. 4, the folding plate moving crank plate 134 is provided at both ends of the folding plate crankshaft 137 and is connected to a folding plate crank drive motor 139 via a crankshaft drive large gear 138. Further, as shown in FIG. 5, the folding plate guide 136 is joined to a side plate 151 that is fixedly provided inside the sheet post-processing apparatus FR.

  In the above configuration, the folding plate crank drive motor 139 is transported in a state in which the sheet bundle S creased by the folding blade 19 is folded in two by the transport roller 38 so that the saddle stitching position is at the head. When reaching between the folding plates 20a and 20b, the folding plate moving crank plate 134 is driven to rotate by one round. When the folding plate crank driving motor 139 rotates, the rotation of the folding plate crank driving motor 139 is transmitted to the folding plate moving crank plate 134, and the rotation of the folding plate moving crank plate 134 becomes the linear motion of the folding plate moving crank rod 135. Converted. When the folding plate moving crank rod 135 moves linearly, the press shaft 133a connected to the folding plate moving crank rod 135 moves linearly while the moving direction is regulated by the folding plate guide 136. By the linear movement of the press shaft 133a, the press pressing member 133b connected to the press shaft 133a presses the folding plate 20a toward the folding plate 20b, and the sheet bundle S sandwiched between the folding plates 20a and 20b. Then, the folding plate 20a is driven so as to be separated from the folding plate 20b.

  In the above example, the folding plate moving crank plate 134 is rotated by one turn so that the press pressing member 133b presses the folding plate 20a only once toward the folding plate 20b. It is also possible to increase the number of times of pressurization by the press pressure member 133b by further rotating the moving crank plate 134. For example, the number of pressurizations may be increased as the number of sheets increases according to the number of sheets constituting the sheet bundle.

  The sheet bundle that has been subjected to the folding process by the press unit is conveyed by the conveying roller 38 to the middle folded paper discharge roller 22. Then, the paper is discharged to the middle folded paper discharge tray 23 by the middle folded paper discharge roller 22 and stacked on the middle folded paper discharge tray 23.

  As described above in detail with specific examples, the sheet post-processing apparatus according to the present embodiment is aligned on the staple tray 10 and is stapled by the staple unit 5 when the sheet bundle is saddle stitched. The folding roller 19 is acted on the bound sheet bundle to crease the saddle stitching position, and the conveyance roller 38 in a state where the sheet bundle is folded in two so that the folded saddle stitching position is at the top. Is conveyed to the press unit. Then, in a state where the saddle stitching position of the sheet bundle is sandwiched between the pair of folding plates 20a and 20b of the press unit, the pressurizing mechanism 21 presses one folding plate 20a toward the other folding plate 20b, so that saddle stitching is performed. The folded sheet bundle is folded. As described above, the sheet post-processing apparatus FR according to the present embodiment uses inexpensive folding plates 20a and 20b as components, and the sheet bundle is sandwiched and pressed by the folding plates 20a and 20b to be folded into the sheet bundle. It is the structure to apply. For this reason, it is possible to appropriately fold the sheet bundle without causing an increase in cost and without causing scratches or wrinkles on the sheet bundle, and it is possible to discharge a booklet having a good finished state.

(Second Embodiment)
Next, a paper post-processing apparatus according to the second embodiment will be described. This embodiment is different from the above-described first embodiment in the configuration of a press unit that performs a folding process on a saddle-stitched sheet bundle. Since the configuration other than the press unit of the sheet post-processing apparatus is the same as that of the first embodiment, the same reference numerals are given to the same parts as those of the first embodiment, and duplicate descriptions are given below. Omitted, only the configuration of the press unit characteristic of this embodiment will be described.

  A press unit provided in the sheet post-processing apparatus according to the present embodiment is shown in FIGS. The press unit exemplified in this embodiment includes a moving mechanism (moving means) 200 that moves the pressurizing mechanism 21 in a state in which one folding plate 20a is pressed toward the other folding plate 20b in the transport direction of the sheet bundle S. Is added.

  In the press unit exemplified in the first embodiment described above, the press shaft 133a is connected to the folding plate moving crank rod 135, but in the press unit exemplified in this embodiment, the press shaft 133a of the pressurizing mechanism 21 is provided. A movable support frame 201 is supported so as to be movable in the conveyance direction of the sheet bundle S. The movable support frame 201 is connected to the folding plate moving crank rod 135 via the connecting shaft 202. The movable support frame 201 is formed by bending, for example, a metal plate, and a guide rail 203 that guides the movement of the press shaft 133a is formed on a flange portion that rises along the conveyance direction of the sheet bundle S. It is attached.

  A press pressure member 133b such as a compression spring is connected to the press shaft 133a that is movably supported with respect to the movable support frame 201, as in the first embodiment. In the present embodiment, however, a press roller 133c is rotatably attached to the tip of the press pressure member 133b. The pressurizing mechanism 21 of this embodiment is configured to press the folding plate 20a toward the folding plate 20b by pressing the rotatable press roller 133c against the folding plate 20a. The mechanism for moving the movable frame 201 that supports the press shaft 133a so as to be movable in the transport direction of the paper S is the same as that in the first embodiment.

  As the moving mechanism 200 that moves the press shaft 133a (that is, the pressurizing mechanism 21) in the conveyance direction of the sheet bundle S, for example, a linear moving mechanism using a rack 204 and a pinion 205 is used. In this case, the end of the press shaft 133 a is connected to the rack 204 via the guide rail 203, and the pinion drive motor 206 is connected to the pinion 205 that meshes with the rack 204. As a result, the rotation of the pinion 205 driven by the pinion drive motor 206 is converted into a linear motion of the rack 204, and the press shaft 133a connected to the rack 204 is moved along the guide rail 203 in the conveyance direction of the sheet bundle S. be able to.

  In the pressurizing mechanism 21 of the present embodiment configured as described above, the sheet bundle S creased by the folding blade 19 is conveyed in a folded state by the conveying roller 38 so that the saddle stitching position is at the head. When it reaches between the pair of folding plates 20a and 20b, the folding plate crank drive motor 139 starts rotating. Then, the rotation of the folding plate moving crank plate 134 is converted into a linear motion of the folding plate moving crank rod 135, and the movable support frame 201 descends along the folding plate guide 136. When the movable frame 201 is lowered, an urging force is applied to the press pressure member 133b by the press shaft 133a supported by the movable frame 201, and a press roller 133c provided at the tip of the press pressure member 133b causes the folding plate 20a to move. Pressurize toward the folding plate 20b. In this state, the rotation of the folding plate crank drive motor 139 is stopped, and the state where the press roller 133c presses the folding plate 20a is maintained.

  Thereafter, the pinion drive motor 206 starts to rotate, and the rotation of the pinion drive motor 206 is transmitted to the pinion 205 and converted into a linear motion of the rack 204. When the rack 204 moves linearly, the press shaft 133 a connected to the rack 204 moves along the guide rail 203 in the conveyance direction of the sheet bundle S. Along with the movement of the press shaft 133a, the press pressure member 133b and the press roller 133c connected to the press shaft 133a move in the transport direction of the sheet bundle S (position indicated by a one-dot chain line in FIG. 6), and the press roller 133c. Presses the folding plate 20a while rolling on the folding plate 20a.

  As described above in detail with specific examples, the paper post-processing apparatus according to the present embodiment uses the pressurizing mechanism 21 that presses the folding plate 20a toward the folding plate 20b. A moving mechanism 200 for moving in the transport direction is provided, and the press roller 133c of the pressurizing mechanism 21 presses the folding plate 20a while rolling on the folding plate 20a. Folding can be performed, and the finished state of the booklet can be further improved.

(Third embodiment)
Next, a paper post-processing apparatus according to the third embodiment will be described. The present embodiment is a modification of the above-described second embodiment, in which the folding plate 20a pressed by the pressurizing mechanism 21 is curved along the transport direction of the sheet bundle, and the pressurizing mechanism 21 is a sheet. The folding plate 20a swings as it moves in the bundle conveying direction. In addition, since the structure of the pressurization mechanism 21 and the moving mechanism 200 is common to 2nd Embodiment, below, the same code | symbol is attached | subjected about the same part as 2nd Embodiment, and the overlapping description is given. Omitted, only the parts characteristic of this embodiment will be described.

  FIG. 8 shows a press unit provided in the paper post-processing apparatus according to this embodiment. In the press unit illustrated in this embodiment, one of the pair of folding plates 20a and 20b has a shape that is curved along the conveyance direction of the sheet bundle S. Specifically, the folding plate 20a has a convex curved surface on the surface facing the folding plate 20b, and a concave curved surface on the opposite side of the folding plate 20b. The press roller 133c rolls.

  When the press roller 133c rolls in the conveying direction of the sheet bundle S while the bent folding plate 20a is pressed toward the folding plate 20b as described above, the pressing action point of the press roller 133c against the folding plate 20a moves. As a result, the folding plate 20a swings as shown by the one-dot chain line in FIG. Then, the folding plate 20a swings in this manner, so that the folding is performed reliably without distributing pressure to the saddle stitching position of the sheet bundle S sandwiched between the folding plates 20a and 20b. Can be applied.

  As described above, in the sheet post-processing apparatus according to the present embodiment, one folding plate 20a of the pair of folding plates 20a and 20b sandwiching the saddle stitching position of the sheet bundle is curved along the sheet bundle conveying direction. The pressurizing mechanism 21 pressurizes the curved folding plate 20a toward the other folding plate 20b while swinging the curved folding plate 20a. Accordingly, folding can be performed at the saddle stitch position of the sheet bundle without dispersing the pressure, and the finished state of the booklet can be further improved. Further, although pressure is concentrated on the sheet bundle while the folding plate 20a is swung, the sheet bundle comes into contact with the surfaces of the folding plates 20a and 20b, so that the sheet bundle is damaged such as scratches and wrinkles. I will not let you.

  As described above, the present invention is useful as a technique for appropriately folding a saddle stitching position so that the booklet does not bulge when binding a plurality of sheets discharged from the image forming apparatus. is there.

5 Staple unit 10 Staple tray 19 Folding blades 20a, 20b Folding plate 21 Pressure mechanism 38 Conveying roller 200 Moving mechanism

Claims (3)

An alignment tray for stacking and aligning a plurality of sheets discharged from the image forming apparatus;
Binding means for performing saddle stitching on the bundle of sheets aligned in the alignment tray;
A folding blade that creases the saddle stitching position of the sheet bundle that has been saddle-stitched by the binding means;
Conveying means for conveying the sheet bundle with the saddle stitch position where the crease is made by the folding blade as a head;
A pair of folding plates that sandwich the saddle stitching position of the sheet bundle conveyed by the conveying means;
Pressurizing means for pressurizing one of the pair of folding plates to the other side,
The pressurizing means is
A press shaft connected to one of the pair of folding plates via a pressure member and having a direction intersecting the pressure direction as an axial direction ;
A guide member for restricting the moving direction of the press shaft;
A crank plate that rotates by driving the motor;
A crank rod having one end connected to an eccentric position of the crank plate and the other end connected to the press shaft;
The press shaft passes through the guide member;
The pressure member and one folding plate connected to the pressure member are arranged on one side in the axial direction of the guide member,
The crank rod and the crank plate connected to the crank rod are disposed on the other side of the guide member in the axial direction,
The rotation of the crank plate is converted into a linear motion of the crank rod, and the press shaft connected to the crank rod is moved to one side of the pair of folding plates along the guide member, whereby the pressurization is performed. One of the pair of folding plates is pressed against the other side by a member. Both of the pair of folding plates have a flat shape,
The sheet post-processing according to claim 1, further comprising a moving unit that moves the pressing unit in a state in which one of the pair of folding plates is pressed to the other side in the transport direction of the sheet bundle. apparatus.   3. The sheet post-processing according to claim 1, wherein a surface treatment process for reducing friction between the pair of folding plates and the sheet bundle is performed on opposing main surface portions. apparatus.

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