JP2017081665A - Post-processing device and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a post-processing device which can accurately perform alignment processing to sheets loaded on a loading part without increase in the size and cost of the device and an image formation apparatus.SOLUTION: A post-processing device includes: a discharge claw 67 (conveyance means) which conveys sheets P loaded in a loading part 61 in a state of abutting against a fence part 66 toward the side of a sheet discharge port 50b; and a sheet discharge roller pair 55 (discharge means) which conveys and discharges the sheets P conveyed by the discharge claw 67 to the outside of the device. After the desired number of sheets P is loaded on the loading part 61 and before the sheets P are conveyed to the position of the fence part 66, the sheets P are conveyed by the discharge claw 67 and made to abut in such a manner that they are held between the discharge claw 67 and the sheet discharge roller pair 55, and the sheets P are conveyed to the position of the fence part 66.SELECTED DRAWING: Figure 4

Description

  The present invention provides a post-processing device that performs post-processing on a sheet on which an image is formed by the image forming device, and an image forming device such as a copying machine, a printer, a facsimile, or a multi-functional device including the post-processing device. In particular, the present invention relates to a post-processing apparatus that performs alignment processing on sheets stacked on a stacking unit inside the apparatus, and an image forming apparatus.

Conventionally, in post-processing devices installed in image forming apparatuses such as copiers and printers, after alignment processing on sheets (sheet bundles) stacked on a stacking unit (tray) installed in the apparatus A technique of discharging these sheets to the outside of the apparatus after processing is widely used (see, for example, Patent Documents 1 and 2).
Specifically, sheets on which images are formed in the main body of the image forming apparatus are sequentially conveyed into the post-processing apparatus and stacked on the mounting surface of the stacking unit. Then, after a desired number of sheets (sheet bundle) are stacked on the stacking section, the sheet stack is conveyed so as to abut against a fence section installed so as to stand on one end side of the stacking section. Alignment processing is performed on the bundle. Then, post-processing such as binding processing is further performed on the sheet bundle after the alignment processing is performed. Then, the sheet bundle after the post-processing is transported to the vicinity of the paper discharge port by a claw-like member (discharge claw) as a transport means, and thereafter, a pair of paper discharge rollers (discharge means) outside the apparatus. The paper is discharged toward the external tray installed in the printer and loaded on the external tray.

A conventional post-processing apparatus transports a desired number of sheets of paper (sheet bundle) so as to abut against a fence section installed so as to stand up on one end side of the stacking section after being stacked on the stacking section. Therefore, when the alignment process is performed on the paper, the alignment accuracy of the paper may be insufficient.
On the other hand, it is also conceivable to separately provide an alignment mechanism for aligning the sheets stacked on the stacking unit in the vicinity of the stacking unit. However, in that case, the apparatus may be increased in size and cost as much as a new alignment mechanism is provided.

  The present invention has been made to solve the above-described problems, and can accurately perform alignment processing on sheets stacked on a stacking unit without increasing the size and cost of the apparatus. It is another object of the present invention to provide a post-processing apparatus and an image forming apparatus.

  The post-processing apparatus according to the present invention is a post-processing apparatus that performs post-processing on a sheet on which an image has been formed by the image forming apparatus. The post-processing apparatus is installed inside the apparatus and includes a stacking unit on which sheets are stacked, A fence unit installed on one end side of the stacking unit away from the paper mouth and formed to stand on the mounting surface of the stacking unit, and stacked on the stacking unit in a state of being abutted against the fence unit A conveying unit that conveys the discharged paper toward the discharge port, and a sheet that is installed in the vicinity of the discharge port, conveys the sheet conveyed by the conveying unit toward the outside of the apparatus, and discharges the sheet. Discharging means, and after the desired number of sheets are stacked on the stacking unit and before the sheets are transported to the position of the fence unit, the sheets are transported by the transporting unit. The conveying means and the discharging means; Abutted against so as to be interposed between, is intended to subsequently convey the sheet to the position of the fence unit.

  According to the present invention, there is provided a post-processing device and an image forming apparatus that can accurately perform alignment processing on paper stacked on a stacking unit without increasing the size and cost of the device. be able to.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. It is a schematic block diagram which shows a post-processing apparatus. It is an enlarged view which shows the principal part of a post-processing apparatus. It is a figure which shows operation | movement of a post-processing apparatus. It is a figure which shows operation | movement of the post-processing apparatus following FIG.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

First, the overall configuration and operation of the image forming apparatus 1 will be described with reference to FIG.
In FIG. 1, 1 is a copying machine as an image forming apparatus, 2 is a document reading unit that optically reads image information of a document D, and 3 is a photosensitive member that exposes light L based on the image information read by the document reading unit 2. An exposure unit for irradiating the drum 5, 4 an image forming unit for forming a toner image (image) on the photosensitive drum 5, and 7 for transferring the toner image formed on the photosensitive drum 5 to a sheet P (sheet) A transfer unit (image forming unit), 10 is a document transport unit that transports a set document D to the document reading unit 2, 12 to 14 are paper feed units that store paper P such as transfer paper, and 17 and 18 are A registration roller (timing roller) that conveys the paper P toward the transfer unit 7, a fixing device 20 that fixes an unfixed image on the paper P, a fixing roller 21 installed in the fixing device 20, and a fixing device 20. The pressure roller 30 is installed on the front side. It inverts the paper P after but formed shows a two-sided conveyance unit, which transported toward the image forming unit.
Reference numeral 50 denotes a post-processing device that performs post-processing on the paper P discharged from the image forming apparatus main body 1 and carried in. Reference numeral 61 denotes a stacking unit (internal tray) installed in the post-processing device 50. Indicates a tray (paper discharge tray) on which the post-processed paper P (or paper bundle) is discharged and stacked. The post-processing device 50 is detachably installed on the image forming apparatus main body 1.

With reference to FIG. 1, an operation during normal image formation in the image forming apparatus main body 1 will be described.
First, the document D is conveyed from the document table in the direction of the arrow in the drawing by the conveyance roller of the document conveyance unit 10 and passes over the document reading unit 2. At this time, the document reading unit 2 optically reads the image information of the document D passing above.
Then, the optical image information read by the document reading unit 2 is converted into an electric signal and then transmitted to the exposure unit 3 (writing unit). Then, exposure light L such as laser light based on the image information of the electrical signal is emitted from the exposure unit 3 toward the photosensitive drum 5 of the image forming unit 4.

On the other hand, in the image forming unit 4, the photosensitive drum 5 is rotated in the clockwise direction in the drawing, and image information is transferred onto the photosensitive drum 5 through a predetermined image forming process (charging process, exposure process, development process). An image (toner image) corresponding to is formed.
Thereafter, the image formed on the photosensitive drum 5 is transferred onto the paper P conveyed by the registration rollers 17 and 18 in the transfer unit 7 as an image forming unit.

On the other hand, the sheet P conveyed to the transfer unit 7 (image forming unit) operates as follows.
First, one of the plurality of paper feeding units 12, 13, and 14 of the image forming apparatus main body 1 is automatically or manually selected (for example, the uppermost paper feeding unit 12 is selected). To do.)
Then, the uppermost sheet P of the paper P stored in the paper feeding unit 12 is transported toward the position of the transport path K1.

  Thereafter, the sheet P passes through a conveyance path K1 in which a plurality of conveyance rollers are arranged, and reaches the position of the registration rollers 17 and 18. Then, the sheet P that has reached the position of the registration rollers 17 and 18 is conveyed toward the transfer unit 7 (image forming unit) at the same timing in order to align with the image formed on the photosensitive drum 5. Is done.

  Then, after the transfer process, the sheet P passes through the position of the transfer unit 7 and then reaches the fixing device 20 through the conveyance path. The sheet P that has reached the fixing device 20 is fed between the fixing roller 21 and the pressure roller 22, and the image is fixed by the heat received from the fixing roller 21 and the pressure received from both members 21 and 22. . The sheet P on which the image is fixed is delivered from between the fixing roller 21 and the pressure roller 22 (a nip portion), and then discharged from the image forming apparatus main body 1.

  Note that when the “double-sided printing mode” for performing printing on both sides of the paper P (the front side and the back side) is selected, the paper P that has undergone the fixing process on the front side is described above. The paper is not discharged as it is when the “single-sided printing mode” is selected, but is guided to the double-sided conveyance path K2, and the conveyance direction is reversed by the double-sided conveyance unit 30, and then the transfer unit 7 ( It is conveyed toward the position of the image forming unit. Then, an image is formed on the back surface of the sheet P by the same image forming process as described above at the position of the transfer unit 7, and then passes through the conveyance path through a fixing process in the fixing device 20. And discharged from the image forming apparatus main body 1.

Here, in the present embodiment, the post-processing device 50 is installed in the image forming apparatus 1, and the paper P discharged from the image forming apparatus main body 1 is transported to the post-processing device 50, and the transported paper P Is post-processed.
Referring to FIG. 1, post-processing device 50 in the present embodiment transports paper P transported from device main body 1 to one of three transport routes K3 to K5, and performs different post-processing. It is comprised so that it can give. The first transport path K3 is a transport path for discharging the paper P transported from the image forming apparatus main body 1 to the first paper discharge tray 71 as it is without performing post-processing. The second transport path K4 stacks the paper P transported from the image forming apparatus main body 1 on the stacking unit 61 (internal tray), and performs alignment processing and binding processing to the rear end of the paper by the first stapler 90. This is a transport path for discharging the processed paper P (paper bundle) from the paper discharge outlet 50b toward the external tray 72 (second paper discharge tray) by the paper discharge roller pair 55. In the third transport path K5, after the paper P transported from the image forming apparatus main body 1 is transported to the second transport path K4 and switched back, the binding process to the center of the paper by the second stapler 83, This is a conveyance path for performing a folding process by the sheet folding blade 84 and the like and discharging the sheet to the third sheet discharge tray 73 (see also FIG. 2).
The above-described switching of the three transport paths K3 to K5 is performed by a switching operation (rotation) of the branch claw 81.

More specifically, referring to FIG. 2, a first transport roller 51 and a paper detection sensor are installed in the vicinity of the carry-in port 50a of the post-processing apparatus 50, and the paper P detected by the paper detection sensor is the first. 1, and transported into the apparatus 50 by the second transport rollers 51 and 52. Then, based on the post-processing mode selected in advance by the user, the branching claw 81 rotates so that the paper P is guided to the desired transport paths K3 to K5.
When the mode in which no post-processing is performed is selected, the paper P transported to the first transport path K3 is discharged by the third transport roller 53 and is discharged onto the first paper discharge tray 71.

When the “sort mode (sorting processing mode)” is selected, the paper P transported to the second transport path K4 is configured to be movable in the width direction (the vertical direction in FIG. 2). Each paper P is transported while being shifted in the width direction by a predetermined amount for each sheet P, and is transported by a pair of paper discharge rollers 55 (fifth transport roller) and on the external tray 72 (second paper discharge tray). Are sequentially loaded.
The paper discharge roller pair 55 is configured to be able to release (contact / separate) the pressure contact state between the driving roller 55a and the driven roller 55b, and during the shift movement of the paper P by the fourth transport roller 54. Is controlled to be in a separated state (the state shown in FIG. 3). Specifically, as shown in FIG. 3, a pair of paper discharge rollers 55 as discharge means includes a drive roller 55a that is rotatably supported in the vicinity of the paper discharge port 50b, and a support plate 65 (centering on a support shaft 65a). And a driven roller 55b that is rotatably supported by the roller. Then, the support plate 65 is rotated about the support shaft 65a by a contact / separation mechanism (not shown), so that the driven roller 55b is pressed against the drive roller 55a and functions as the discharge roller pair 55 to convey the paper P. In other words, the driven roller 55b is separated from the driving roller 55a and does not function as the paper discharge roller pair 55.

  Referring to FIG. 2, a filler 82 is provided above the external tray 72 so as to be rotatable about a support shaft at the upper end, and the external tray 72 is configured to be movable up and down by a moving mechanism (not shown). ing. Then, a state in which the central portion in the transport direction of the sheets P sequentially stacked on the external tray 72 is in contact with the filler 82 is detected by a sensor installed in the vicinity of the support shaft of the filler 82, thereby The height of the stacked paper P is recognized. Then, the vertical position of the external tray 72 is adjusted according to the increase or decrease of the number of sheets P stacked on the external tray 72. Further, when the vertical position of the external tray 72 reaches the lower limit position, it is assumed that the number of sheets P stacked on the external tray 72 has reached the upper limit (full) and the post-processing device 50 to the image forming apparatus 1. A stop signal is transmitted to stop the image forming operation.

  When the “stapling mode (binding processing mode)” is selected, the sheet P transported to the second transport path K4 is transported by the fourth transport roller 54 without being shifted, and loaded in the stacking unit 61 ( It is sequentially stacked on the internal tray. When a desired number of sheets P (sheet bundle) are stacked on the mounting surface 62 of the stacking unit 61, as will be described in detail later with reference to FIG. A first alignment process (a process of aligning the positions in the transport direction of the paper P) with respect to the paper P (paper bundle) by the paper discharge roller pair (discharge means) is performed. Then, with respect to the sheet P (sheet bundle) on which the first alignment processing has been performed, the tapping roller 64 disposed above the sheet P moves to a position where it abuts on the uppermost sheet P, and the tapping roller 64 is shown in FIG. By rotating and driving in the counterclockwise direction 2, a plurality of sheets P (sheet bundle) are conveyed (moved) toward the fence unit 66. As a result, the rear end (rear end in the transport direction) of the plurality of sheets P (sheet bundle) abuts against the fence 66, and the positions in the transport direction of the plurality of sheets P are aligned (second alignment). Processing).

At this time, referring to FIG. 2, jogger fences 68 installed at both ends in the width direction of stacking unit 61 move in the width direction so as to sandwich a plurality of sheets P stacked on stacking unit 61. Thus, the positions in the width direction of the plurality of sheets P are aligned. Then, the first stapler 90 performs the binding process on the rear end of the paper P (paper bundle) in which the transport direction and the width direction are aligned.
Thereafter, the sheet P (sheet bundle) on which the binding process has been performed moves obliquely upward along the inclination of the placement surface 62 by the movement of the discharge claw 67 (claw-like member) serving as a conveying unit in the paper discharge direction. The paper is discharged onto the external tray 72 by conveyance by a pair of paper discharge rollers 55 as discharge means.

Referring to FIG. 3, the discharge claw 67 as the transport means is driven in the forward direction (in the counterclockwise direction in FIG. 3) and in the reverse direction (in the clockwise direction in FIG. 3) by driving by the driving means. The claw-like member is disposed on the belt member 91 so as to be able to travel in any of the directions, and extends from one end side to the other end side (or from the other end side to the other end along the mounting surface 62 of the stacking portion 61. Side). The belt member 91 is stretched and supported by a plurality of roller members 92 to 94, and is forwardly or reversely driven by the rotation of one roller member 92 connected to a forward / reverse direction rotation type drive motor (drive means). Travel in the direction. A part of the belt member 91 is disposed along the placement surface 62 of the stacking unit 61, and the discharge claw 67 fixed at a predetermined position on the belt member 91 travels together with the belt member 91. Thus, the discharge claw 67 moves from the lower right side in FIG. 3 toward the upper left side (or from the upper left side to the lower right side) along the placement surface 62. As described above, together with the discharge claw 67, the belt member 91, the roller members 92 to 94, the driving means, and the like are obliquely directed toward the paper discharge port 50b with the paper P stacked on the stacking unit 61 in a state of being in contact with the fence unit 66. It functions as a transport means for transporting upward. Note that the stacking unit 61 is provided with a notch so that the discharge claw 67 can move along the mounting surface 62 in a state of protruding on the mounting surface 62.
In addition, after the operation | movement which the sheet | seat P loaded on the stacking part 61 conveys toward the position of the fence part 66 is complete | finished, the discharge nail | claw 67 is FIG. The position of the belt member 91 in the traveling direction is controlled so as to be located at the retracted position shown in FIG.

When the “folding processing mode” is selected, the sheet P is first transported to the second transport path K4 and the fourth transport roller 54 is moved in a state where the rear end portion is sandwiched between the fourth transport rollers 54. The reverse rotation causes the switchback to be transferred to the third transfer path K5. Then, the paper P transported to the third transport path K5 is transported by the sixth to eighth transport rollers 56 to 58 to a position where the central portion of the paper P faces the second stapler 83. Then, after a desired number of sheets P (sheet bundle) is stacked at that position, the second stapler 83 performs a binding process on the central portion of the sheet bundle. Thereafter, the plurality of sheets P (sheet bundle) subjected to the binding process are moved to a position where the central portion of the sheet P (sheet bundle) faces the sheet folding blade 84 by the seventh and eighth transport rollers 57 and 58. Be transported. At this time, the sheet P (sheet bundle) is in a state where the leading end of the sheet P abuts against a stopper portion 85 (configured to be movable in the transport direction by a moving mechanism not shown).
Then, the sheet P (sheet bundle) is subjected to folding processing in a state where the center portion is folded by the sheet folding blade 84 moving to the left in FIG. Will be. Thereafter, the paper P (paper bundle) after the folding process is transported by the ninth transport roller 59 and discharged onto the third paper discharge tray 73.

Hereinafter, the characteristic configuration and operation of the post-processing device 50 in the present embodiment will be described in detail.
As described above with reference to FIGS. 2 and 3, the post-processing device 50 according to the present embodiment has a stacking unit 61 (internal tray) on which sheets P are stacked (loaded). is set up. In addition, the post-processing device 50 has a discharge claw 67 (as a transporting unit) that transports the paper P stacked (mounted) on the stacking unit 61 toward the paper discharge port 50b in a state of being in contact with the fence unit 66. Claw-like member) is provided. Specifically, the loading surface 61 of the stacking unit 61 is directed upward from one end side (the right side in FIGS. 2 and 3) to the other end side (the left side in FIGS. 2 and 3). It is formed so as to be inclined. Further, a fence portion 66 formed so as to stand up with respect to the placement surface 62 is provided on one end side of the stacking portion 61 away from the paper discharge outlet 50b. Further, as described above with reference to FIG. 3, the discharge claw 67 (conveying means) is installed on the belt member 91 that travels in the forward and reverse directions by driving by the driving means, and extends along the placement surface 62. Thus, it is configured to move from one end side to the other end side (or from the other end side to one end side).
Further, in the post-processing device 50 in the present embodiment, the paper P conveyed by the discharge claw 67 (conveying means) is directed to the outside of the post-processing device 50 (external tray 72) in the vicinity of the paper discharge port 50b. A paper discharge roller pair 55 is installed as a discharge means for conveying and discharging. The paper discharge roller pair 55 includes a driving roller 55a and a driven roller 55b, and is configured such that the driven roller 55b can contact and separate from the driving roller 55a.

  Here, the post-processing device 50 according to the present embodiment refers to FIGS. 4A and 4B, when the “staple mode (binding processing mode)” described above is selected. After the desired number of sheets P (sheet bundle) is stacked on the section 61 and before the sheet P (sheet bundle) is conveyed to the position of the fence section 66, the sheet P (sheet bundle) is loaded. It is transported by a discharge claw 67 (conveying means) as a claw-shaped member and abuts against the discharge claw 67 and the paper discharge roller pair 55 so as to be sandwiched between the discharge claw 67 and the paper discharge roller pair 55 (discharge means). Then, as shown in FIGS. 4C and 5A, the paper P (paper bundle) is subsequently transported to the position of the fence portion 66.

That is, in the present embodiment, after a desired number of sheets P (sheet bundle) are stacked on the stacking unit 61, the sheet P is rotated with the tapping roller 64 in contact with the uppermost sheet P. (Sheet of sheets) is conveyed obliquely toward the fence portion 66 and the paper P is abutted against the fence portion 66 and the alignment process is not performed once. Alignment processing that is used and alignment processing that uses the fence portion 66 are performed twice.
Thereby, the alignment accuracy of the conveyance direction with respect to the paper P (paper bundle) can be reliably improved. In particular, the single alignment process that hits the fence unit 66 using the hitting roller 64 as described above is performed depending on the magnitude of the frictional force generated between the sheets P stacked on the stacking unit 61. The conveying force of the hitting roller 64 with respect to the bundle may change, and the sheet bundle that hits the fence portion 66 may be misaligned (alignment failure). Since the magnitude of the frictional force generated between the paper P and the paper P varies depending on the type of the paper P, the image formed on the paper P, and the like, it is a problem that cannot be ignored.
On the other hand, in the present embodiment, the alignment process is performed using the fence unit 66 after the discharge claw 67 and the discharge roller pair 55 sandwich the paper P (paper bundle) in the transport direction. Therefore, as described above, misalignment (alignment failure) hardly occurs in the sheet bundle regardless of the magnitude of the frictional force generated between the sheets P.
Further, in the present embodiment, an aligning mechanism for performing alignment processing of the sheets P stacked on the stacking unit 61 is not separately provided in the vicinity of the stacking unit 61, but a discharge claw 67 that functions as a transport unit, and a discharge unit Since the aligning process is performed using the paper discharge roller pair 55 that functions as the post-processing device 50, it is possible to suppress a problem that the post-processing device 50 is increased in size and cost.

Hereinafter, the operation of the main part of the post-processing device 50 when the “stapling mode (binding processing mode)” is executed will be described in more detail with reference to FIGS. 4 and 5.
First, as shown in FIG. 4A, in the stacking unit 61, the discharge claw 67 (conveying means) is on the upstream side (obliquely upward) of the fence unit 66 (the position in FIG. 4A). In this state, the sheets P sequentially conveyed by the fourth conveying roller 54 are stacked so as to abut against the discharge claw 67. At this time, each time the paper P is placed on the stacking unit 61, the tapping roller 64 (see FIG. 2) is brought into contact with the paper P so as to be conveyed toward the discharge claw 67. Can also be rotationally driven.

At this time, referring to FIG. 4A, the standby position of the discharge claw 67 (conveying means) when a desired number of sheets P (sheet bundle) is stacked on the stacking unit 61 is the size M of the sheet P. It is variable according to (the size in the transport direction). Specifically, when a sheet P having a short size M is stacked on the stacking unit 61, the sheet P is closer to the paper discharge roller pair 55 than when a sheet P having a long size M is stacked on the stacking unit 61. The standby position of the discharge claw 67 is adjusted. However, in any case, the standby position of the discharge claw 67 is a position where the stacking of the paper P on the stacking unit 61 is not hindered, and is at least smaller than the size M in the transport direction of the paper P. The distance H1 in the transport direction from the abutting position to the nip portion of the paper discharge roller pair 55 is set to be large (H1> M).
With this configuration, the distance that the discharge claw 67 moves from the standby position to the position where the paper P abuts against the paper discharge roller pair 55 can be shortened almost uniformly regardless of the size M of the paper P. Further, it is possible to reduce a problem that the time required for the alignment process (the time for which the discharge claw 67 moves) is increased and the productivity of the post-processing is reduced.

In the present embodiment, the standby position of the discharge claw 67 is configured to vary according to the size M in the conveyance direction of the paper P. However, the standby position of the discharge claw 67 is changed according to other characteristics of the paper P. Further, it can be configured to be variable. Specifically, the standby position of the discharge claw 67 (conveying means) when a desired number of sheets P are stacked on the stacking unit 61 is the size of the sheet P (not limited to the size in the conveying direction) and the sheet thickness. , Stiffness, curl amount, moisture content, image (image formed on paper P and image area), and charge amount can be varied according to at least one of them. .
When the size of the paper P is large, the frictional force acting on the paper P and the paper P when stacked on the stacking unit 61 is larger than when the size of the paper P is small, and the transport direction in the stacking unit 61 is increased. Therefore, the sheet P loaded on the stacking unit 61 is surely discharged by shifting the standby position of the discharge claw 67 with a margin to the downstream side in anticipation of the shift. It is possible to abut against the abutment portion of the nail 67. Even when the paper thickness, stiffness, curl amount, moisture content, image, and charge amount of the paper P are large, loading is greater than when the paper thickness, stiffness, curl amount, moisture content, image, and charge amount of the paper P is small. Since the frictional force acting on the paper P and the paper P when loaded on the section 61 is increased, the standby position of the discharge claw 67 is similarly finely adjusted.
The various characteristics of the paper P described above can be detected by known detection means. Based on the detection result of the detection means, the drive means of the discharge claw 67 (belt member 91) is controlled.

  Then, after a desired number of sheets P (sheet bundle) are stacked on the stacking unit 61 as shown in FIG. 4A, the sheets P (sheet bundle) are discharged as shown in FIG. 4B. While being pushed by the claw 67 (claw-like member), it moves in the direction of the white arrow from one end side to the other end side, and the paper discharge roller pair is sandwiched between the discharge claw 67 and the paper discharge roller pair 55. The sheet P is abutted against 55 (and the discharge claw 67). Accordingly, the plurality of sheets P (sheet bundle) are aligned so as to be sandwiched between the abutting portion of the discharge claw 67 and the nip portion of the discharge roller pair 55, and the alignment process in the transport direction is good. Will be done.

Here, in the present embodiment, as shown in FIG. 4B, the paper P is moved from one end side to the other end side while being pushed by the discharge claw 67, and the discharge claw 67 and the discharge roller pair. The paper ejection roller pair 55 is rotated in the reverse direction with respect to the forward rotation direction along the transport direction of the paper P. Specifically, the drive roller 55a is driven to rotate clockwise in FIG. 4B, and the driven roller 55b is driven to rotate counterclockwise in FIG. 4B.
Thus, even if the paper P (paper bundle) pushed by the discharge claw 67 hits the nip portion of the paper discharge roller pair 55, it does not enter the nip portion of the paper discharge roller pair 55. Therefore, as the next operation, the operation of transporting the paper P toward the fence portion 66 is smoothly performed without entering or being caught in the nip portion.

Further, in the present embodiment, referring to FIG. 4B, when the paper P is conveyed by the discharge claw 67 and abutted so as to be sandwiched between the discharge claw 67 and the paper discharge roller pair 55, The stop position of the discharge claw 67 is adjusted so that the distance H2 in the transport direction between the discharge claw 67 and the paper discharge roller pair 55 is shorter by a predetermined amount α than the size M in the transport direction of the paper P (M = H2 + α).
As a result, even if there is a slight variation in the length in the transport direction of the plurality of sheets P, all the plurality of sheets P are sandwiched between the discharge claw 67 and the discharge roller pair 55 and aligned. Processing can be performed reliably.
Further, with the above-described configuration, the paper P (paper bundle) sandwiched between the discharge claw 67 and the paper discharge roller pair 55 is bent by a predetermined amount α, and the reaction force due to the bending is generated. As a result, the sheet P is aligned properly by the forces that come into contact with the discharge claw 67 and the discharge roller pair 55, respectively.

Note that the predetermined amount α described above is preferably varied according to the size M in the transport direction of the paper P. This is because if the amount of deflection of the paper P when sandwiched between the discharge claw 67 and the paper discharge roller pair 55 becomes large instead of the size M of the paper P, the discharge claw 67 and the paper discharge roller pair 55. This is because there is a possibility that misalignment may occur due to the sheet P bouncing when the nipping is released. Therefore, when the paper P having a small size M is stacked, the predetermined amount α is adjusted to be smaller than when the paper P having a large size M is stacked.
For example, when a sheet P having a size M of less than 110 mm is stacked, the predetermined amount α is set to 1 mm. When a sheet P having a size M of 110 mm or more and less than 150 mm is stacked, the predetermined amount α is 2 mm. When a sheet P having a size M of 150 mm or more is stacked, the predetermined amount α is set to 3 mm, and the distance H2 described above is adjusted.

  Then, as shown in FIG. 4 (B), the sheet P (sheet bundle) subjected to the first alignment process sandwiched between the discharge claw 67 and the discharge roller pair 55 is shown in FIG. 4 (C). As shown in FIG. 4, the discharge claw 67 with the paper P abutted is moved in the direction of the white arrow along the placement surface 62 toward the fence portion 66, and the paper P (paper bundle) is conveyed together with the discharge claw 67. Will do. At this time, the tapping roller 64 (see FIG. 2) disposed above the sheet P (sheet bundle) in a state of being in contact with the discharge claw 67 moves to a position where it abuts on the uppermost sheet P. Then, the tapping roller 64 is driven to rotate counterclockwise in FIG. 2, whereby a plurality of sheets P (sheet bundle) are conveyed toward the fence unit 66.

Here, in the present embodiment, when the sheet P subjected to the first alignment process described above is transported toward the fence section 66, as shown in FIG. The paper discharge roller pair 55 is separated. In other words, the paper P is moved from one end side toward the other end side while being pushed by the discharge claw 67 (claw-like member), and is abutted so as to be sandwiched between the discharge claw 67 and the paper discharge roller pair 55. Later, the driving roller 55a and the driven roller 55b of the paper discharge roller pair 55 are separated from each other.
As a result, when the sheet P that has been subjected to the first alignment process is started to be transported toward the fence unit 66, the sheet P is caught by the paper discharge roller pair 55, resulting in an alignment failure. Can be prevented.

4C, in this embodiment, when the drive roller 55a and the driven roller 55b of the paper discharge roller pair 55 are separated as described above, the drive roller 55a is moved in the conveyance direction of the paper P. Is rotated in the reverse direction (the clockwise direction in FIG. 4C) with respect to the forward direction of rotation along the direction.
Thus, even when the lowermost sheet P of the sheet bundle is likely to be caught by the drive roller 55a, the lowermost sheet P is conveyed toward the fence 66 by the drive roller 55a rotating in the reverse direction. Therefore, it is possible to suppress a problem that alignment failure occurs.

The operation of rotating the driving roller 55a in the reverse direction when the paper discharge roller pair 55 is separated in this way can be performed only when the size M in the transport direction of the paper P is equal to or larger than the predetermined value X. That is, as shown in FIG. 4C, when the driving roller 55a and the driven roller 55b of the paper discharge roller pair 55 are separated from each other, and the size M in the transport direction of the paper P is equal to or larger than the predetermined value X. The drive roller 55a can be rotated in the reverse direction (the clockwise direction in FIG. 4C) with respect to the forward rotation direction along the conveyance direction of the paper P.
This is because, when paper P having a small size M is stacked, the drive roller 55a is rotated in the reverse direction with the paper discharge roller pair 55 being spaced apart, and the paper P pops out along the rotation, resulting in poor alignment. This is because there is a possibility of occurrence. Note that the predetermined value X serving as the threshold value of the size M is set to about 182 mm.

Then, when the paper P moves further obliquely downward together with the discharge claw 67 in a state where it hits the discharge claw 67 as shown in FIG. 4C, eventually the paper P (paper bundle) as shown in FIG. ) Hits the fence 66, and the second alignment process is performed. At this time, the discharge claw 67 moves along the locus of the belt member 91 shown in FIG. 3 to a retreat position that does not hinder the operation of the paper P hitting the fence portion 66.
Then, as shown in FIG. 5A, the sheet P is subjected to the second alignment process by hitting against the fence unit 66 (the sheet P stacked on the stacking unit 61 in the state of hitting the fence unit 66). ) Is moved in the direction of the white arrow along the loading surface 62 toward the position of the paper discharge roller pair 55 as shown in FIG. 5B by the discharge claw 67 moving in the forward direction from the retracted position described above. (Conveyed).
Then, as shown in FIG. 5C, the paper P (paper bundle) that has reached the position of the paper discharge roller pair 55 is sandwiched and conveyed by the paper discharge roller pair 55 that rotates in the forward direction, and the paper discharge port 50b is discharged and placed on the external tray 72.

As described above, the post-processing device 50 according to the present embodiment has the discharge claw 67 (carrying the paper P stacked on the stacking unit 61 in a state of being in contact with the fence unit 66 toward the discharge port 50b. And a paper discharge roller pair 55 (discharge means) that conveys and discharges the paper P conveyed by the discharge claw 67 toward the outside of the apparatus. Then, after the desired number of sheets P are stacked on the stacking unit 61 and before the sheet P is transported to the position of the fence unit 66, the sheet P is transported by the discharge claw 67 and discharged. The sheet P is abutted so as to be sandwiched between the sheet discharge roller pair 55 and the sheet discharge roller pair 55, and then the sheet P is conveyed to the position of the fence portion 66.
As a result, it is possible to accurately perform the alignment process on the paper P stacked on the stacking unit 61 without increasing the size and cost of the post-processing device 50.

In the present embodiment, the present invention is applied to the post-processing apparatus 50 installed in the monochrome image forming apparatus 1. However, the present invention is naturally applied to the post-processing apparatus installed in the color image forming apparatus. The present invention can be applied.
In the present embodiment, the present invention is applied to the post-processing apparatus 50 installed in the electrophotographic image forming apparatus 1. However, the application of the present invention is not limited to this, and other systems. Naturally, the present invention can also be applied to a post-processing apparatus installed in an image forming apparatus (for example, an inkjet image forming apparatus or a stencil printing apparatus).
Further, the post-processing device 50 is not the post-processing device 50 connected to the image forming apparatus 1, but a post-processing device as a single device (for example, a paper feed cassette is set in the carry-in port 50a, and the post-processing device itself has a processing mode, etc. The present invention can also be applied to a case where an operation panel for inputting is installed.
Even in those cases, the same effects as in the present embodiment can be obtained.

In the present embodiment, another post-processing device (for example, a device that performs Z-folding processing on the paper P) is installed between the image forming apparatus main body 1 and the post-processing device 50. You can also.
In the present embodiment, the present invention is applied to the post-processing device 50 that can perform the binding process, the sorting process, and the folding process. However, the application of the present invention is not limited to this, and the punching is performed. Alignment processing is also performed for post-processing devices that perform processing (punch processing), post-processing devices that perform only one of the above-described processing, and post-processing devices that perform processing in a different combination Of course, the present invention can be applied.

  It should be noted that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be modified as appropriate within the scope of the technical idea of the present invention, other than suggested in the present embodiment. is there. In addition, the number, position, shape, and the like of the constituent members are not limited to the present embodiment, and the number, position, shape, and the like suitable for implementing the present invention can be achieved.

  In the present application, the state in which sheets are stacked on the stacking unit is defined to include a state in which one sheet is placed in addition to a state in which a plurality of sheets are stacked.

1 image forming apparatus body (apparatus body),
50 aftertreatment devices,
50b paper exit,
55 discharge roller pair (discharge means),
55a driving roller, 55b driven roller,
61 Loading section (inner tray),
62 Placement surface (tray surface),
66 Fence part (abutment part),
67 discharge claw (claw-like member, conveying means),
72 External tray,
P Paper (sheet).

Japanese Patent No. 5151711 JP 2013-139335 A

Claims (10)

A post-processing apparatus that performs post-processing on a sheet on which an image is formed by an image forming apparatus,
A loading unit installed inside the apparatus and on which paper is loaded;
A fence portion installed on one end side of the stacking portion away from the paper discharge port and formed to stand with respect to a mounting surface of the stacking portion;
Conveying means for conveying the paper stacked on the stacking unit in a state of being abutted against the fence unit toward the discharge port;
A discharge unit installed in the vicinity of the discharge port and configured to convey and discharge the sheet conveyed by the conveyance unit toward the outside of the apparatus;
With
After the desired number of sheets are stacked on the stacking unit and before the sheet is conveyed to the position of the fence unit, the sheet is conveyed by the conveying unit, and the conveying unit and the discharging unit A post-processing apparatus, wherein the paper is conveyed to a position of the fence unit. The loading portion is formed such that the placement surface is inclined upward from one end side to the other end side,
The transport means includes a claw-like member configured to be movable in the forward and reverse directions along the placement surface of the stacking unit,
The post-processing apparatus according to claim 1, wherein the discharge unit is a pair of discharge rollers including a driving roller and a driven roller.   When the paper is pushed by the claw-like member and moved from one end side to the other end side and is struck between the claw-like member and the paper discharge roller pair, the paper discharge The post-processing apparatus according to claim 2, wherein the roller pair is rotated in a reverse direction with respect to a normal rotation direction along the sheet conveyance direction.   The paper is moved from one end side to the other end side while being pushed by the claw-like member and abutted so as to be sandwiched between the claw-like member and the paper discharge roller pair, and then the paper discharge The post-processing apparatus according to claim 2 or 3, wherein the driving roller and the driven roller of the roller pair are separated from each other.   The drive roller and the driven roller of the paper discharge roller pair are separated from each other in a reverse direction with respect to a normal rotation direction along the sheet conveyance direction. Item 5. A post-processing apparatus according to item 4.   When the drive roller and the driven roller of the paper discharge roller pair are separated from each other and the size in the paper transport direction is equal to or larger than a predetermined value, the drive roller is moved in the positive direction along the paper transport direction. 6. The post-processing apparatus according to claim 5, wherein the post-processing apparatus is rotated in a direction opposite to the direction of rotation.   When the desired number of sheets are stacked on the stacking unit, the standby position of the conveying means is at least one of the size, sheet thickness, stiffness, curl amount, moisture content, image, and charge amount of the sheet. The post-processing apparatus according to any one of claims 1 to 6, wherein the post-processing apparatus is variable according to the above.   The distance in the transport direction between the transport unit and the discharge unit when the sheet is transported by the transport unit and abutted so as to be sandwiched between the transport unit and the discharge unit is the transport direction of the sheet The post-processing apparatus according to claim 1, wherein the stop position of the conveying unit is adjusted so as to be shorter than the size by a predetermined amount.   The post-processing apparatus according to claim 8, wherein the predetermined amount is varied according to a size in a conveyance direction of the paper.   An image forming apparatus comprising the post-processing device according to claim 1.

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