JP3736078B2 - Sheet post-processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet post-processing apparatus that aligns recording sheets sequentially discharged from an image forming apparatus such as an electrophotographic copying machine to form a predetermined sheet bundle and then performs post-processing such as stapling on the sheet bundle. In particular, the present invention relates to an improvement in a sheet post-processing apparatus capable of automatically performing a so-called saddle stitch binding process.
[0002]
[Prior art]
In the so-called saddle stitch bookbinding process, after a recording sheet is aligned with a predetermined sheet bundle, a stapling process is performed at a position that bisects the surface of the sheet bundle, and a booklet is formed by folding the sheet bundle at this stapling position. This process is suitable for bookbinding of a relatively small number of recording sheets and has a good appearance after bookbinding, and is optimal for bookbinding of recording sheets output from an electrophotographic copying machine, a printer, or the like.
[0003]
In order to perform such saddle stitch binding processing, two types of processing, that is, stapling processing and folding processing, are required. Of these, the latter folding processing uses a folding knife to fold a sheet bundle between a pair of folding rolls. There are known a knife edge method in which the recording sheet is pushed in between and a stopper method in which a recording sheet bent against the stopper is held between a pair of folding rolls.
[0004]
Here, as the former knife edge method, one disclosed in Japanese Utility Model Laid-Open No. 64-45660, specifically, as shown in FIG. 15, the aligned sheet bundle 100 is conveyed onto a horizontal processing tray 101. After that, the folding knife 102 is brought into contact with the sheet bundle 100 from above the processing tray 101, and the sheet bundle 100 is pushed between the pair of folding rolls 103 disposed on the lower side of the processing tray 101. A folding device is known in which the sheet bundle 100 is folded in half by a folding roll 103.
[0005]
On the other hand, the latter stopper method is disclosed in Japanese Patent Laid-Open No. 6-72064. Specifically, as shown in FIG. After the bundle 104 is bent in the sheet conveyance path 106, the middle portion of the sheet bundle 104 is sandwiched between the pair of folding rolls 107 using the waist of the sheet bundle 104, and the folding roll 107. An apparatus is known in which the sheet bundle 104 is bent in half.
[0006]
[Problems to be solved by the invention]
However, in the case of the former knife edge method, when the processing tray on which the sheet bundle is placed is disposed obliquely, the sheet bundle accommodated in the processing tray bends downward due to the influence of gravity. Therefore, there is a problem that the contact position of the folding knife with respect to the sheet bundle is easily shifted from the center of the sheet bundle, and the quality of the folding process is deteriorated. Even when the processing tray is horizontally disposed, when the pair of folding rolls are disposed on the upper side of the processing tray and the folding knife is disposed on the lower side of the processing tray, the folding knife When the sheet bundle is lifted between the folding rolls, the center of the sheet bundle is likely to be displaced with respect to the folding knife, and in this case also, there is a problem that the sheet bundle cannot be folded in half. .
[0007]
Therefore, in order to perform the folding process of the sheet bundle accurately using this knife edge method, the processing tray must be disposed horizontally and the folding roll must be disposed below the processing tray. The apparatus disclosed in Japanese Utility Model Laid-Open No. 64-45660 adopts this layout. However, when such a configuration is adopted, when the saddle stitching process is performed on an A3 size recording sheet, the width of the apparatus becomes remarkably large, so that the sheet post-processing apparatus of the copying machine used in Otis is used. Is extremely inconvenient. In such a configuration, since the sheet bundle that has been subjected to the folding process is transported to the lower side of the processing tray, a booklet tray that discharges the sheet bundle that has undergone the saddle stitching process must be provided at a low position. In addition, it is difficult to take out the completed saddle stitch booklet.
[0008]
On the other hand, when the latter stopper method is adopted, such a problem does not occur. However, the sheet bundle is held between the pair of folding rolls using the deflection of the sheet bundle locked to the stopper. Therefore, when the sheet bundle becomes thick, it cannot be held in the folding roll, and the way of bending is different depending on the strength of the waist of the sheet bundle. In order to bend the sheet, the position of the stopper and the gap in the sheet conveyance path must be finely adjusted, and the adjustment work is troublesome.
[0009]
The present invention has been made in view of such problems, and an object of the present invention is to perform high-quality saddle stitch binding without performing troublesome adjustment work, as well as a copying machine, An object of the present invention is to provide a small sheet post-processing apparatus that can be used in an office alongside a printer or the like.
[0010]
[Means for Solving the Problems]
That is, the sheet post-processing apparatus according to the present invention is a sheet post-processing apparatus that forms a sheet bundle by storing recording sheets sequentially discharged from the image forming apparatus in a compiler tray and then folding the sheet bundle. A folding knife disposed so as to be movable in and out with respect to the compiler tray, and disposed facing the compiler tray at a position facing the folding knife, and the sheet on the compiler tray by the folding knife. A pair of folding rolls into which the bundle is pushed, and a booklet tray from which the sheet bundle folded by the folding roll is discharged; and when the sheet bundle is pushed into the folding roll by the folding knife, the sheet bundle Is placed on the compiler tray, and the sheet bundle can be pulled out only in the folding roll direction. It is characterized in that the door pressing member is disposed.
[0011]
According to such a technical means, the sheet bundle formed on the compiler tray is lifted by the folding knife protruding from the compiler tray and pushed between a pair of folding rolls opposed to the folding knife. Further, the sheet bundle pushed between the folding rolls is folded into two by the folding roll and then discharged to the booklet tray.
[0012]
That is, in the apparatus of the present invention, the sheet bundle is folded by the knife edge method described above. When the folding knife pushes the sheet bundle between the folding rolls, the sheet bundle is compiled by the sheet restraining member. Because the sheet bundle is held on the tray, the sheet bundle lifted from the compiler tray is not displaced with respect to the folding knife, and the folding knife is always brought into contact with the position that bisects the sheet bundle. be able to. In addition, even when the sheet bundle is sandwiched between the sheet restraining members, the sheet bundle can be pulled out from the sheet restraining member in the direction to be fed to the folding roll. It is not disturbed by the restraining member.
[0013]
For this reason, the compiler tray is disposed obliquely, and even when a folding roll is provided on the upper side of the compiler tray, the sheet bundle can be folded in half, and the lateral width is small. In addition, it is possible to manufacture a sheet post-processing apparatus in which the booklet tray is located at a position with good workability.
[0014]
Here, the sheet restraining member may have any configuration as long as it holds the sheet bundle so that the sheet bundle accommodated in the compiler tray does not move when the folding process is performed. Even if the sheet bundle is sandwiched so that the folding knife does not interfere with pushing the sheet bundle into the pair of folding rolls, the sheet bundle can be pulled out only in the direction of the folding roll. Must. For example, a pad having a high friction coefficient in a certain direction and a low friction coefficient in the reverse direction or a roll incorporating a one-way clutch can be used as the sheet restraining member.
[0015]
In addition, when there is a sheet conveyance roll that matches the center of the sheet bundle with the folding knife on the compiler tray, a one-way clutch is incorporated in the sheet conveyance roll to exhibit the function as the sheet suppression member. You may comprise as follows.
[0016]
Furthermore, the sheet holding member may be provided only on one side of the pair of folding rolls, but when the compiler tray is disposed at an inclination, in order to prevent the sheet bundle from being bent downward, It is preferable to dispose at least the lower side of the folding roll pair.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the sheet post-processing apparatus of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a sheet post-processing apparatus (finisher) 20 according to the present invention which is used by being attached to an image forming apparatus 10 such as a laser beam printer. The finisher 20 is a finisher body 30 fixed to the image forming apparatus. And an elevator tray portion 40 arranged to be movable up and down with respect to the finisher body.
[0018]
The finisher 20 aligns the recording sheets 1 sequentially discharged from the image forming apparatus 10 to form a predetermined number of sheet bundles 2 and then performs a stapling process on the edge of the sheet bundle 2. In addition, a so-called saddle stitch bookbinding process in which the stapling process is performed on the center position of the sheet bundle 2 and the sheet bundle 2 is folded at the stapling position to form a booklet can be selectively performed. The edge binding processing function is mainly provided in the finisher main body 30 and the saddle stitching processing function is mainly provided in the elevator tray unit 40.
[0019]
A sheet discharge port 31 through which the sheet bundle is discharged from the finisher body 30 is opened on the side surface of the finisher body 30 to which the elevator tray section 40 is mounted. By moving the elevator tray section 40 up and down, Any one of the plurality of trays provided in the elevator tray section 40 can be set as the sheet discharge port 31. A fixed tray 32 is disposed in the finisher body 30 corresponding to the sheet discharge port 31, and the tray on the elevator tray side and the fixed tray 32 are flush with each other via the sheet discharge port 31. A compiler tray for stacking the recording sheets 1 is formed continuously.
[0020]
On the other hand, a sheet conveying roll 33 for sending the recording sheet 1 conveyed from the image forming apparatus 10 toward the sheet discharge port 31 is disposed above the fixed tray 32. A part of the recording sheet 1 fed out by the above-mentioned is projected out of the finisher body 30 from the sheet discharge port 31 and is accommodated across the fixed tray 32 and the tray on the elevator tray side. A paddle wheel 34 for sliding the recording sheet 1 toward the lower end edge of the fixed tray 32 is disposed on the upper side of the fixed tray 32, and side edges of the recording sheet 1 are provided on both sides thereof. A tamper (not shown) for aligning is provided, and the recording sheets 1 stacked on the compiler tray are aligned by the operation of the paddle wheel 34 and the tamper so that a predetermined sheet bundle 2 is formed. It has become.
[0021]
Further, an end binding stapler 35 is provided at the lower end edge of the fixed tray 32, and the stapling process is selectively performed on the edge of the sheet bundle 2 aligned at a predetermined position on the fixed tray 32. It is configured to apply.
[0022]
Further, a pair of discharge rolls 36 and a support roll 37 are disposed inside the sheet discharge port 31 with the fixed tray 32 interposed therebetween, and the sheet bundle 2 on the fixed tray 32 is rotated by the rotation of the discharge roll 36. Are discharged to the stacking trays 42 and 43. Further, the discharge roll 36 is configured so that it can be retreated from the fixed tray 32 by swinging the arm 38 so that the discharge operation of the recording sheet 1 to the fixed tray 32 is not hindered. It is set on the tray 32 and is configured to sandwich the sheet bundle 2 on the fixed tray 32 together with the support roll 37.
[0023]
On the other hand, the elevator tray section 40 is provided with a saddle stitching processing unit 41 for performing saddle stitching bookbinding processing, and a sheet bundle 2 that is disposed above the saddle stitching processing unit 41 at an interval and subjected to edge stitching processing. Alternatively, the first stacking tray 42 from which the sheet bundle 2 not subjected to the binding process is discharged is provided, and the saddle stitching processing unit 41 and the first stacking tray 42 move up and down integrally with respect to the finisher body 30. It is configured as follows. The saddle stitching processing unit 41 further includes an upper unit 41a and a lower unit 41b. The upper surface of the upper unit 41a is used as a second stacking tray 43 similar to the first stacking tray 42, The upper surface of the lower unit 41b is an alignment tray (hereinafter referred to as a saddle stitching tray) 44 for the sheet bundle 2 on which saddle stitch bookbinding processing is performed.
[0024]
Of these first and second stacking trays 42 and 43 and the saddle stitching tray 44 provided in the elevator tray section 40, the saddle stitch bookbinding process is required for the recording sheet 1 discharged from the image forming apparatus. In this case, the saddle stitching tray 44 is set to the sheet discharge port 31 of the finisher body 30 (see FIG. 1), and the first or second stacking trays 42 and 43 are set to the sheet discharge port 31 in other cases. Thus, a compiler tray corresponding to the content of the stapling process (binding process) is formed between the finisher body 30 and the elevator tray unit 40.
[0025]
Next, details of the saddle stitching processing unit 41 will be described.
In the saddle stitching processing unit 41, a stapling process and a folding process are performed on the center position of the sheet bundle 2 aligned by the saddle stitching tray 44, and the booklet subjected to these processes is finally the upper unit. It is configured to be discharged to a booklet tray 45 provided in 41a.
[0026]
A stitcher head 46 with a built-in staple needle is built in the upper unit 41 a, while a clincher head 47 that bends the tip of the staple needle is built in the lower unit 41 b, and the sheet bundle 2 accommodated in the saddle stitching tray 44. The sheet bundle 2 is subjected to a stapling process by the heads 46 and 47 opposed to each other. However, in order to sequentially store the recording sheets 1 in the saddle stitching tray 44, a gap of a certain size must be formed between the upper unit 41a and the lower unit 41b, and the clincher head 47 is connected to the lower unit 41a. If it is fixedly arranged with respect to 41b, the gap between the sheet bundle 2 accommodated in the saddle stitching tray 44 and the stitcher head 46 is widened, and the staple position is accurately set to the center position of the sheet bundle 2. It becomes impossible to perform processing.
[0027]
For this reason, the lower unit 41 b is provided with a bottom plate 48 for lifting the sheet bundle 2 accommodated in the saddle stitching tray 44 toward the upper unit 41 a, and the clincher head 47 is fixed to the tip of the bottom plate 48. When the sheet bundle 2 is lifted by the bottom plate 48, the stitcher head 46 and the clincher head 47 are brought close to each other with the sheet bundle 2 interposed therebetween.
[0028]
As shown in FIG. 2, one end of the bottom plate 48 is fixed to the lower unit 41b by a support shaft 49, while the other end to which the clincher head 47 (not shown) is fixed is slightly bent downward. The entire bottom plate 48 is configured to swing around the support shaft 49. The bottom plate 48 is configured to swing according to the movement of the lift-up roll 50 that contacts the lower surface of the bottom plate 48, and the lift-up roll 50 is driven by the drive shaft 51. Is moved in a planetary shape, and the bottom plate 48 is pushed up from below. Therefore, when the drive shaft 51 is rotated by the motor 52, the front end of the bottom plate 48 protrudes from the saddle stitching tray 44 in accordance with the movement of the lift-up roll 50, and the sheet bundle stored in the saddle stitching tray 44. 2 is lifted toward the stitcher head 46 in the upper unit 41a, and the clincher head 47 located at the tip of the bottom plate 48 is close to and faces the stitcher head 46. 2 is a position sensor for detecting that the drive shaft 51 is set at a specific rotational position. By checking the output signal of the sensor 53, the bottom plate 48 is moved to the home position. That is, it can be determined whether or not it is accommodated in the lower unit 41b.
[0029]
On the other hand, the folding process for the sheet bundle 2 subjected to the saddle stitching process in this way is disposed in the first and second folding roll pairs 54 and 55 disposed in the upper unit 41a and the lower unit 41b. This is performed by a folding knife 56 for pushing the sheet bundle 2 from below between the first folding roll pair 54 (see FIG. 1).
[0030]
In order to accurately match the folding position of the sheet bundle 2 with the stapling processing position, as shown in FIG. 3, the first folding roll pair 54 has a stapling processing position where the stitcher head 46 and the clincher head 47 face each other. , And the sheet bundle 2 pushed between the first folding roll pair 54 by the folding knife 56 is folded in two by the first folding roll pair 54, and then in FIG. The second folding roll pair 55 is inserted along the arrow line, and is discharged to the booklet tray 45 of the upper unit 41a through the pair of booklet discharge rolls 57. A timing belt 58 is wound around the first and second folding roll pairs 54 and 55 and the booklet discharge roll 57, and the driving force of the motor 59 is supplied to the rolls 54, 55 and 56 via the timing belt 58. To be communicated to. A driving force is transmitted to one roll of the first folding roll pair 54 from one roll of the second folding roll pair 55 via the gear train 60.
[0031]
The folding knife 56 is disposed so as to be swingable with respect to the lower unit 41 b, and its leading edge portion 56 a faces the middle of the first folding roll pair 54, so that the sheet in the saddle stitching tray 44 is arranged. When the alignment process of the bundle 2 and the stapling process for the sheet bundle 2 are performed, the bundle 2 is stored in the lower unit 41 b without being pushed out from the saddle stitching tray 44. When the folding process is performed, the entire folding knife 56 is swung so that the tip edge portion 56a protrudes from the lower side to the upper side of the bottom plate 48, and between the bottom plate 48 and the upper unit 41a. The sandwiched sheet bundle 2 is configured to be pushed into the first folding roll pair 54.
[0032]
As shown in FIGS. 4 and 5, the first folding roll pair 54 is spaced apart in the axial direction so that the folding knife 56 can reliably push the sheet bundle 2 into the first folding roll pair 54. On the other hand, the tip edge portion 56a of the folding knife 56 is formed in a comb-tooth shape so as to avoid interference with the folding roll 54. Further, as described above, in the finisher of this embodiment, the stapling processing position by the stitcher head 46 and the clincher head 47 and the processing position of the folding process for the sheet bundle 2 overlap each other. The one-fold roll pair 54 is arranged so as to avoid interference with the stitcher head 46, and the tip edge portion 56 a is formed in a comb shape so as to avoid interference with the clincher head 47.
[0033]
As described above, the first folding roll pairs 54 are arranged while being spaced apart in the axial direction, and it is impossible to reliably form a fold with respect to the sheet bundle 2 with only the first folding roll pair 54. As shown in FIG. 6, the second folding roll pair 55 is disposed uniformly along the width direction of the sheet bundle 2, so that the folds can be formed uniformly along the width direction of the sheet bundle 2. It has become. Further, a spring 61 is stretched around the shaft ends of the two folding rolls constituting the second folding roll pair 55, and the folding rolls 55 are firmly pressed against each other, so that the sheet bundle 2 can be reliably secured. A crease can be formed.
[0034]
On the other hand, as shown in FIG. 5, when the stitcher head 46 is present on the conveyance path of the sheet bundle 2 by the first folding roll pair 54, the sheet bundle 2 is placed between the first folding roll pair 54. Therefore, the stitcher head 46 is configured to retract from the pair of first folding rolls 54 arranged so as not to interfere with the conveyance of the sheet bundle 2 after the stapling process is completed. Yes.
[0035]
FIG. 7 shows a moving mechanism of the stitcher head 46. The stitcher head 46 is configured to move freely along the lower surface of the upper unit 41a, and is always urged toward the stapling position (the one-dot chain line position in FIG. 7) by its own weight. . Further, the roller follower 62 is erected on the stitcher head 46, and an eccentric cam 63 that contacts the roller follower 62 is disposed on the upper unit 41a. The cam 63 and the roller follower 62 are always in contact with each other. Accordingly, when the rotation of the motor 64 is transmitted to the eccentric cam 63 by the belt 65, the stitcher head 46 moves in the direction of the arrow according to the rotational position of the eccentric cam 63, and the step moves from the stapling position to the retracted position indicated by the broken line. The tea head 41a can be retracted, and the stapling processing position can be reset from the retracted position. Reference numeral 66 in FIG. 7 is a home position sensor for checking whether or not the stitcher head 46 is set at the retracted position.
[0036]
Further, in the finisher of this embodiment, in order to improve the maintenance of staple needle supply to the stitcher head 46 and the needle clogging trouble, the stitcher head 46 is moved to a work position further rearward than the retracted position. It can be pulled out and various maintenance operations can be performed at this position. That is, as shown in FIG. 8, one end of a link 68 that rotates about a support shaft 67 is locked to the stitcher head 46, and when the other end of the link 68 is lifted and the link 68 is rotated. The stitcher head 46 is configured to largely retract from the retracted position indicated by the solid line to the working position indicated by the alternate long and short dash line. In particular, in this embodiment, the booklet tray 45 provided in the upper unit 41a is provided with an opening / closing lid 69, and the opening / closing lid 69 is connected to the link 68. When the opening / closing lid 69 is lifted, the stitcher head 46 is moved. It is pulled out to a work position directly below the opening / closing lid 69.
[0037]
FIG. 9 shows various setting positions of the stitcher head 46. FIG. 9A shows the stapling process position for performing the saddle stitching process on the sheet bundle 2, and FIG. 9B shows the folding process position. FIG. 9C shows the working position when the staple needle is replenished or the like. As shown in this figure, when the opening / closing lid 69 provided on the booklet tray 45 is lifted, the stitcher head 46 is pulled out from the retracted position to the working position immediately below the opening / closing lid 69 by the rotation of the link 68 described above. Therefore, the operator can easily perform maintenance work on the stitcher head 46, and the workability is improved.
[0038]
On the other hand, the saddle stitching processing unit 41 is provided with a sheet holding member that operates in conjunction with the bottom plate 48. In other words, when the bottom plate 48 lifts the sheet bundle 2 toward the upper unit 41a, in other words, a sheet. When the stapling process is performed on the bundle 2 and the folding process is performed on the sheet bundle 2, the sheet pressing member is configured to press the sheet bundle 2 and prevent the positional deviation thereof. Yes. The sheet pressing member is provided between the sheet discharge port 31 and the first folding roll pair 54 and is in pressure contact with the sheet bundle 2 accommodated in the saddle stitching tray 44 from above, and the bottom. The support roll 71 is arranged so as to be rotatable with respect to the plate 48 and sandwiches the sheet bundle 2 together with the pinch roll 70 (see FIG. 1). The pinch roll 70 or the support roll 71 Includes a one-way clutch capable of conveying the sheet bundle 2 only toward the first folding roll pair 54. As shown in FIG. 2, the pinch roll 70 is configured to move up and down in accordance with the rotation of the transmission shaft 72. The transmission shaft 72 includes a drive shaft 51 and a crank 73 that are responsible for the vertical movement of the bottom plate 48. Are connected through. Therefore, when the drive shaft 51 is rotated by the motor 52, the bottom plate 48 on which the support roll 71 is mounted rises in accordance with the operation of the lift-up roll 50 as described above, while the transmission shaft 72 rotates to pinch roll. The sheet bundle 2 accommodated in the saddle stitching tray 44 is held down by the pinch roll 70 and the support roll 71.
[0039]
10 and 11 show the operation of the finisher of the present embodiment when the saddle stitch bookbinding process is performed on an A3 size recording sheet.
First, when the saddle stitch bookbinding process is selected, the entire elevator tray unit 40 moves up and down with respect to the finisher body 30, and the saddle stitch tray 44 is set to a position corresponding to the sheet discharge port 31 of the finisher body 30. The saddle stitching tray 44 and the fixed tray 32 form a compiler tray for the recording sheet 1. In this state, the recording sheets 1 are sequentially accommodated in the saddle stitching tray 44 as shown in FIG. 10A, and a sheet bundle 2 in which these recording sheets 1 are aligned is formed. At this time, the discharge roll 36 is retracted from the tray so as not to hinder the discharge of the recording sheet 1 to the compiler tray. When the alignment of the sheet bundle 2 is completed, the support is provided as shown in FIG. In combination with the roll 37, the sheet bundle 2 is sandwiched, and the alignment state of the sheet bundle 2 is prevented from being lost in the subsequent processing.
[0040]
Next, when the alignment process of the sheet bundle 2 in the saddle stitching tray 44 is finished, as shown in FIG. 10C, the bottom plate 48 is raised as a preparation for performing the stapling process, and the sheet bundle 2 is moved. It is sandwiched between the stitcher head 46 of the upper unit 41a and the clincher head 47 of the lower unit 41b. In conjunction with the rising of the bottom plate 48, the pinch roll 70 comes into contact with the sheet bundle 2 and sandwiches the sheet bundle 2 together with the support roll 71 provided on the bottom plate 48. Then, the stitcher head 46 is operated in a state where the sheet bundle 2 is fixed in this manner, and the stapling process is performed on the sheet bundle 2.
[0041]
When the stapling process is finished, the stitcher head 46 moves from the stapling process position to the retracted position as shown in FIG. 10D, while the sheet bundle 2 by the discharge roll 36 as shown in FIG. 10E. Is released. However, in this state, the bottom plate 48 still lifts the sheet bundle 2 toward the first folding roll pair 54, so the pinch roll 70 is in a state of sandwiching the sheet bundle 2 together with the support roll 71. .
[0042]
Then, as shown in FIG. 10 (f), when the folding knife 56 swings from this state, the center portion of the sheet bundle 2 is pushed between the first folding roll pair 54 by the leading edge portion 56 a of the folding knife 56. Then, the folding process is performed by passing between the first folding roll pair 54 and the second folding roll pair 55 in a folded state. Further, the folded sheet bundle 2 is discharged to the booklet tray 45.
[0043]
During the folding process, the sheet bundle 2 is sandwiched between the pinch roll 70 and the support roll 71 adjacent to the lower side of the first folding roll pair 54, and is firmly fixed by these rolls 70 and 71. Even if the folding knife 56 pushes the sheet bundle 2 between the first folding roll pair 54, the alignment state of the sheet bundle 2 is not lost, and the sheet bundle 2 does not slide down in the saddle stitching tray 44. Absent. Therefore, in the finisher of this embodiment, the center position of the sheet bundle 2 on which the staple needle is driven can be accurately matched with the leading edge portion 56a of the folding knife 56, and the folding process can be performed accurately. It can be done.
[0044]
Further, the pinch roll 70 or the support roll 71 incorporates a one-way clutch and can freely rotate in the direction in which the sheet bundle 2 is fed to the first folding roll pair 54. When the sheet 2 is pushed between the first folding roll pair 54, the pushing operation of the sheet bundle 2 is not hindered by the pinch roll 70, and the folding process of the sheet bundle 2 can be performed smoothly. is there.
[0045]
On the other hand, FIG. 12 shows the operation of the finisher of this embodiment when the saddle stitch bookbinding process is performed on an A4 size recording sheet.
In this finisher, the arrangement position of the stitcher head 46 and the like is determined on the basis of the case where the A3 size recording sheet 1 is accommodated in the saddle stitching tray 44. Therefore, the A4 size recording sheet 1 is placed on the saddle stitching tray 44. When the container is accommodated, the stapling process and the folding process cannot be performed as they are. Therefore, in such a case, each process is performed as follows.
[0046]
First, as shown in FIG. 12A, the recording sheets 1 are sequentially accommodated in the saddle stitching tray 44, and a sheet bundle 2 in which these recording sheets 1 are aligned is formed. However, at this time, the center position of the sheet bundle 2 does not coincide with the stapling processing position where the stitcher head 46 is disposed, and the stapling processing cannot be performed as it is.
[0047]
Therefore, when the alignment of the sheet bundle 2 is completed, the discharge roll 36 sandwiches the sheet bundle 2 together with the support roll 37 as shown in FIG. The sheet is conveyed in the line direction, and the center position of the sheet bundle 2 is matched with the stapling processing position where the stitcher head 46 and the clincher head 47 face each other. From this state, the bottom plate 48 is raised as shown in FIG. 12C, and the stapling process and the folding process are performed in the same manner as in the case of the A3 size recording sheet.
[0048]
In the finisher of the present embodiment described above, a pinch roll 70 is provided in the saddle stitching processing unit 41, and this is used as a sheet restraining member of the present invention. The configuration is not necessarily provided. For example, in the finisher of the present embodiment, a one-way clutch is built in the discharge roll 36 and used as a sheet restraining member of the present invention, and the pinch roll 70 and the support roll 71 can be omitted to simplify the structure. is there.
[0049]
13 and 14 show the procedure of the saddle stitch binding process when the pinch roll 70 and the support roll 71 facing the pinch roll 70 are omitted.
First, as shown in FIG. 13A, the recording sheets 1 are sequentially stored in the saddle stitching tray 44, and a sheet bundle 2 in which these recording sheets 1 are aligned is formed. At this time, the discharge roll 36 is retracted from the tray so as not to prevent the recording sheet 1 from being discharged to the compiler tray. However, when the alignment of the sheet bundle 2 is completed, the support is provided as shown in FIG. In combination with the roll 37, the sheet bundle 2 is sandwiched, and the alignment state of the sheet bundle 2 is prevented from being lost in the subsequent processing.
[0050]
Next, when the alignment process of the sheet bundle 2 in the saddle stitching tray 44 is completed, as shown in FIG. 13C, the bottom plate 48 is raised as a preparation for performing the stapling process, and the sheet bundle 2 is It is sandwiched between the stitcher head 46 of the upper unit 41a and the clincher head 47 of the lower unit 41b. Then, the stitcher head 46 is operated in a state where the sheet bundle 2 is fixed in this manner, and the stapling process is performed on the sheet bundle 2.
[0051]
When the stapling process is completed, the stitcher head 46 is moved from the stapling process position to the retracted position as shown in FIG. 14D, but the discharge roll 36 still holds the sheet bundle 2 and fixes it. 14E, when the folding knife 56 swings from this state, the central portion of the sheet bundle 2 is pushed into the first folding roll pair 54 by the leading edge portion 56a of the folding knife 56. Then, the folding process is performed by passing between the first folding roll pair 54 and the second folding roll pair 55 in a folded state. Further, the folded sheet bundle 2 is discharged to the booklet tray 45. At this time, the discharge roll 36 with a built-in one-way clutch prevents the alignment state of the sheet bundle 2 from collapsing due to the pushing operation of the folding knife 56.
[0052]
【The invention's effect】
As described above, according to the sheet post-processing apparatus of the present invention, when the sheet bundle is folded by the so-called knife edge method, the sheet bundle is sandwiched on the compiler tray by the sheet holding member. Therefore, regardless of the orientation of the compiler tray and the arrangement of the folding rolls, the folding knife can be accurately brought into contact with the sheet bundle, and the sheet bundle can be accurately divided into two to be folded. The degree of freedom regarding the layout of the rolls can be increased, and a sheet post-processing apparatus having a small size and good workability can be manufactured.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a sheet post-processing apparatus of the present invention.
FIG. 2 is a perspective view showing a bottom plate and a pinch roll according to an embodiment.
FIG. 3 is a cross-sectional view showing an internal structure of an upper unit of the saddle stitching processing unit according to the embodiment.
4 is a detailed view of a part A in FIG. 3;
FIG. 5 is a detailed view of part B in FIG. 3;
6 is a detailed view of a part C in FIG. 3. FIG.
7A and 7B are a front view and a plan view showing a moving mechanism of the stitcher head according to the embodiment.
FIG. 8 is a front view showing a mechanism for pulling out the stitcher head according to the embodiment from the retracted position to the working position.
FIG. 9 is a schematic diagram illustrating a stapling processing position, a retracted position, and a working position of the stitcher head according to the embodiment.
FIG. 10 is a diagram illustrating a procedure of saddle stitch binding processing for an A3 size recording sheet of the sheet post-processing apparatus according to the embodiment.
11 is a diagram showing a continuation of the processing procedure shown in FIG.
FIG. 12 is a diagram illustrating a part of a saddle stitch bookbinding process for an A4 size recording sheet of the sheet post-processing apparatus according to the embodiment.
FIG. 13 is a diagram showing a procedure of saddle stitch bookbinding processing when a discharge roll is used as a sheet restraining member.
14 is a diagram showing a continuation of the processing procedure shown in FIG.
FIG. 15 is a schematic diagram illustrating folding processing of a sheet bundle by a knife edge method.
FIG. 16 is a schematic diagram illustrating folding processing of a sheet bundle by a stopper method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus, 20 ... Finisher (sheet post-processing apparatus), 30 ... Finisher main body, 40 ... Elevator tray part, 41 ... Saddle stitch processing unit, 45 ... Booklet tray, 46 ... Stitcher head, 47 ... Clincher head, 54 ... 1st folding roll, 55 ... 2nd folding roll, 56 ... Folding knife, 70 ... Pinch roll (sheet restraining member), 71 ... Support roll (sheet restraining member)

Claims (3)

A sheet post-processing apparatus for forming a sheet bundle by storing recording sheets sequentially discharged from the image forming apparatus in an inclined compiler tray, and then performing a folding process on the sheet bundle,
A folding knife disposed so as to be movable in and out with respect to the compiler tray, and disposed facing the compiler tray at a position facing the folding knife, and the sheet bundle on the compiler tray is pushed in by the folding knife. A pair of folding rolls, a booklet tray from which a bundle of sheets folded by the folding roll is discharged, and a stitcher head and a clincher head that apply a stapling process to the sheet bundle,
A sheet post-processing apparatus, wherein a stapling processing position by the stitcher head and the clincher head and a folding processing position by the pair of folding rolls overlap each other in the compilation tray . 2. The sheet post-processing apparatus according to claim 1, further comprising a sheet pressing member for performing the stapling process and the folding process in a state where the sheet bundle is suppressed, and the sheet pressing member is configured to fold the sheet bundle by the folding knife. A sheet post-processing apparatus characterized in that, when being pushed into a roll, the sheet bundle can be sandwiched on the inclined compiler tray, and the sheet bundle can be pulled out only in the folding roll direction. 3. The sheet post-processing according to claim 1, wherein the sheet bundle is aligned based on a lower end edge portion of the compiler tray, and an end binding stapler is disposed at the lower end edge portion of the compiler tray. apparatus.

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