JP2013134351A - Sheet post-processing device and image forming apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet post-processing device having high conveyability and an image forming apparatus including the same.SOLUTION: The sheet post-processing device includes: receiving rollers 10 and 10' for receiving a sheet P; a temporary placement tray 14 which is arranged below the receiving rollers and has the sheet P temporarily placed thereon; post-processing means 20 which executes post-processing on the placed sheet P or a bundle of placed sheets P; ejecting rollers 12 and 12' which are arranged below the temporary placement tray 14 in a carrying-in direction of the sheet P and ejects, to the outside of the device, the carried-in sheet P as it is or the sheet P placed on the temporary placement tray 14 or the bundle of sheets P placed on the temporary placement tray; and a conveyance assistant flap 32 rotationally moved between a home position where the conveyance assistant flap 32 has one end freely rotatably connected to the temporary placement tray 14 in the vicinity of the ejecting rollers 12 and 12' and has the other end located substantially in parallel with the temporary placement tray 14, and a guide position where the conveyance assistant flap 32 is located so as to bridge the gap between the receiving rollers 10 and 10' and the ejecting rollers 12 and 12'. The image forming apparatus includes the sheet post-processing device.

Description

  The present invention includes a sheet post-processing apparatus that performs post-processing such as stapling, punching, and bending performed on a sheet after an image is formed in the image forming apparatus, and the sheet post-processing apparatus. The present invention relates to an image forming apparatus.

  Conventionally, in a post-processing apparatus that performs post-processing such as stapling and punching processing on a bundle of sheets such as paper, as described in Patent Document 1 and Patent Document 2, After discharging the sheets carried in from the outside (when the post-processing device is included in one image forming device, the pre-process of the post-processing device in the image forming device, the same applies hereinafter), In general, the sheet conveying direction is switched and aligned by abutting against the abutting member.

  In this case, it is a pair of receiving rollers that has a function of receiving sheets from the outside and carrying them into the interior of the post-processing apparatus, and the temporary stacking tray for temporarily stacking the loaded sheets is arranged below the pair of receiving rollers. Is done. A pair of discharge rollers is disposed downstream of the temporary stacking tray in the sheet loading direction.

  The sheets carried into the post-processing apparatus by the pair of receiving rollers are sequentially stacked on the temporary stacking tray. A stack of stacked sheets is sandwiched between the pair of discharge rollers, and is rotated in a direction opposite to the loading direction (conveying direction) by rotating the discharging rollers. The sheet bundle is abutted against the abutting member, and the post-processing is performed by the post-processing device.

  The bundle of sheets after execution of post-processing is sandwiched between the pair of discharge rollers, and the discharge rollers are rotated in the reverse direction to that before execution of post-processing, so that they are sent in the carry-in direction (conveyance direction) to the outside of the apparatus. Ejected and loaded on the loading tray.

  In the post-processing apparatus having the above-described structure, it is necessary to provide a certain length of space between the receiving roller and the discharging roller. It is difficult to regulate the conveyance, and there is a possibility of causing a conveyance defect such that the leading edge of the temporary stacking tray is caught on the temporary stacking tray and rounds when reaching the temporary stacking tray.

  Incidentally, in the image forming apparatus, in addition to a normal sheet, a Z-folded sheet (hereinafter referred to as “Z-folded sheet” in this specification) is conveyed, and post-processing is performed by the post-processing device. There is a case. A Z-folded sheet generally refers to a sheet that is folded in half in the longitudinal direction of a sheet such as A3 or B4 and then folded outward at half of the sheet, and the folded sheet is the side of the side in the longitudinal direction. It is so named because it is Z-shaped when viewed from the top.

  When this Z-folded sheet is carried into the post-processing apparatus with the Z-fold side upstream in the conveying direction, the Z-folded portion is positioned between the pair of discharge rollers, and some reverse drive means (such as a tapping roller) ) In the opposite direction by the rotation of the abutting member and abutted against the abutting member to be aligned. However, if the space between the receiving roller and the discharging roller is too close, the entire Z-folded portion is moved to The Z-folded portion is formed on the outer wall (end fence) of the pair of discharge rollers and the apparatus housing when the first pass is passed and the reverse rollers are rotated by rotation of the discharge rollers and other rollers. There is a possibility of being caught and causing a conveyance failure.

  In order to eliminate the above-mentioned conveyance failure, Patent Document 1 discloses that a distance between the first discharge unit (corresponding to the receiving roller) and the second discharge unit (corresponding to the discharge roller) is based on a predetermined calculation formula. However, if the gap between the two is set so wide, small-size paper is loaded into the post-processing device and discharged directly to the stacking tray outside the device without performing post-processing. In some cases, the distance between the two becomes too long, making it impossible to carry.

  An object of the present invention is to provide a sheet post-processing apparatus having good transportability.

The above-mentioned subject is achieved by the present invention shown below.
The invention described in claim 1 is a sheet post-processing apparatus that performs post-processing such as stapling, punching, and bending performed on a sheet after an image is formed in the image forming apparatus.

  According to the invention described in claim 1, since the conveyance auxiliary flap rises from the home position and is positioned at the guide position, this is in a state of bridging at least a part between the receiving roller and the discharging roller. It is possible to provide a sheet post-processing apparatus having good transportability between the receiving roller and the discharging roller.

It is front sectional drawing which shows the sheet | seat post-processing apparatus of embodiment which is an exemplary aspect of this invention. It is the principal part expanded sectional view which extracted the principal part of the sheet | seat post-processing apparatus shown in FIG. FIG. 2 is a perspective view of a conveyance auxiliary flap and its surroundings in the sheet post-processing apparatus shown in FIG. 1. FIG. 2 is a schematic diagram for explaining a drive mechanism of a conveyance assist flap in the sheet post-processing apparatus shown in FIG. 1. It is a principal part expanded sectional view of the location same as the location shown by FIG. 2 in the conventional sheet | seat post-processing apparatus. It is a principal part expanded sectional view which extracted the principal part of the sheet | seat post-processing apparatus of 2nd Embodiment which is an exemplary aspect of this invention. It is a principal part expanded sectional view of the location same as the location shown by FIG. 6 which shows a mode that the Z fold sheet | seat is conveyed with the conventional sheet | seat post-processing apparatus. It is a principal part expanded sectional view which extracted the principal part of the sheet | seat post-processing apparatus of 3rd Embodiment which is an exemplary aspect of this invention. FIG. 9 is a perspective view of a conveyance assist flap and its surroundings in the sheet post-processing apparatus shown in FIG. 8.

  Hereinafter, a sheet post-processing apparatus and an image forming apparatus of the present invention will be described in detail with reference to the drawings.

  In the following embodiments, the configuration using the stapler 20 that executes the stapling process as the post-processing means is taken as an example. However, in the present invention, post-processing such as drilling (drilling) processing, bending processing, etc. It may be replaced with various post-processing means for executing the above, or a plurality of these means may be provided.

[First Embodiment]
FIG. 1 is a front sectional view showing a sheet post-processing apparatus according to a first embodiment which is an exemplary aspect of the present invention. In FIG. 1, configurations not related to the present invention, such as the lower part of the apparatus, are omitted. Further, in FIG. 1, the illustration of the conveyance assist flap characteristic of the embodiment of the present application (and the present invention) is also omitted, and the detailed illustration is given to FIG.

  As shown in FIG. 1, the sheet post-processing apparatus according to the present embodiment includes an entrance roller 2, 2 ′, an entrance sensor 4, transport rollers 6, 6 ′, a transport guide 8, a receiving roller 10, a housing 40. 10 'and discharge rollers 12, 12', a stapling tray (temporary stacking tray) 14, a tapping roller 16, a staple discharging sensor 18, a stapler (post-processing means) 20, a return roller 22, a jogger The staple unit includes a fence 24 and a reference fence 26. In addition, a discharge tray 28 for placing discharged sheets and a filler 30 are disposed outside the housing 40.

  The sheet discharge port to the sheet discharge tray 8 has a pair structure in which a sheet or a bundle of sheets is sandwiched and discharged by the discharge roller 12 and the discharge roller 12 ′. That is, there are a closed state in which a sheet or a bundle of sheets can be sandwiched and ejected by an approaching / separating operation of the ejection roller 12 driven in the direction of a double arrow B with respect to a fixed ejection roller 12 ′, and an open state in which the sheet is not sandwiched. It is selected appropriately.

  Note that the concept of the sheet post-processing apparatus in the present invention includes all of the stapling portions in the present embodiment, and the receiving rollers 10 and 10 ′ and the discharging rollers 12 and 12 ′ in the conveyance path portion. ', The inlet sensor 4, the transport rollers 6, 6' and the transport guide 8 are not included. Therefore, when the sheet to be processed is upstream of the conveyance guide 8, it is assumed that it is still located outside the sheet post-processing apparatus, and is received and carried into the apparatus by the receiving rollers 10 and 10 '.

  The sheet P on which an image is formed on the surface of the image forming apparatus main body (not shown) is introduced into the housing 40 from the direction of arrow A. The entrance sensor 4 detects that the sheet P has been introduced, and the sheet P sandwiched between the entrance rollers 2 and 2 ′ is sequentially conveyed to the conveyance rollers 6 and 6 ′ and the conveyance guide 8 to receive rollers 10 and 10 ′. Sent to. The sheet P received and clamped by the receiving rollers 10 and 10 ′ is carried into the sheet post-processing apparatus, and the leading end of the sheet P once contacts the staple tray 14 and then reaches between the discharge rollers 12 and 12 ′.

  Here, the subsequent operation of the apparatus is different between the normal mode in which the loaded sheet P is discharged as it is and the stapling process execution mode (edge binding mode) in which the stapling process is performed on the loaded sheet P.

  In the normal mode, the sheet P that has reached the space between the discharge rollers 12 and 12 'is sandwiched between the discharge rollers 12 and 12' that are closed when the discharge roller 12 moves in a direction approaching the discharge rollers 12 '. Then, it is discharged out of the apparatus (outside the housing 40) as it is.

  On the other hand, in the staple processing execution mode, the end of the sheet P that has reached between the discharge rollers 12 and 12 'is discharged from the receiving rollers 10 and 10', and between the discharge rollers 12 and 12 'in the open state. And placed on the staple tray 14. At this time, when the staple paper discharge sensor 18 detects the end of the sheet P, the sheet P is pressed onto the staple tray 14 by the hitting roller 16. The hitting roller 16 performs a pendulum motion in the direction of the double arrow C about the fulcrum and advances to press the upper surface of the sheet P downward. By the operation of the hitting roller 16, the sheet P that has been traveling in the transport direction so far is placed on the lower staple tray 14.

  Positioning in the left-right direction (width direction) of the sheet P, which is a flat plate vertically cut from the staple tray 14 surface, is performed on both the left and right sides (the front side and the back side in FIG. 1) of the staple tray 14 in the sheet loading direction. There is a jogger fence 24 for doing it. Further, at the end of the staple tray 14 on the side of the stapler 20, a reference fence for positioning the end of the sheet P on the side of the stapler 20, which has a bottom portion standing vertically from the surface of the staple tray 14. 26 is arranged.

  The sheet P discharged from the receiving rollers 10 and 10 ′ and placed on the staple tray 14 has a tapping roller 16 that strikes the upper surface thereof, which is opposite to the conveying direction up to that point (direction of arrow A). By rotating in the direction, the transport direction is switched. The return roller 22 also performs a pendulum movement indicated by a double-headed arrow D. The movement makes contact with the upper surface of the sheet P placed on the staple tray 14 and moves the sheet P together with the tapping roller 16 toward the stapler 20. Transport.

  Thereafter, the sheets P are sequentially discharged (carrying in) from the receiving rollers 10 and 10 ′ and placed on the staple tray 14, and abut against the jogger fence 24 and the reference fence 26 by the action of the hitting roller 16 and the return roller 22. As a result, a bundle of sheets P is aligned.

  The bundle of sheets P aligned in this manner is bound by stapling an appropriate portion of the edge of the bundle by the stapler 20. The bundle of sheets P whose ends are closed is then held between the discharge rollers 12 and 12 ′ and discharged out of the apparatus (housing 40).

  As described above, in the normal mode, the sheet P discharged as it is outside the apparatus, or in the stapling process execution mode, the bundle of sheets P (or one sheet P) discharged outside the apparatus after the stapling process is performed. Are stacked on the paper discharge tray 28.

  The filler 30 having one end rotatably fixed above the discharge port in which the discharge roller 12 and the discharge roller 12 ′ are arranged is in contact with the upper surface at the position near the center of the stacked sheets P. There is an upper surface detection sensor (not shown) that detects the height position of the front end (the other end) of the filler 30 near the base of the filler 30 (a portion fixed rotatably), and the stacked sheets P The paper surface height is detected. When the sheet P rises to a predetermined height due to an increase in the number of sheets accumulated on the paper discharge tray 28, the upper surface detection sensor is turned on, and a drive means (not shown) for moving the paper discharge tray 28 up and down is provided as a control unit (not shown). To lower the paper discharge tray 28. When the paper discharge tray 28 is lowered and the upper surface detection sensor is turned off, the controller stops the driving means, and the paper discharge tray 28 stops being lowered. When this operation is repeated and the sheet P on the paper discharge tray 28 reaches a specified full tray height, a stop signal is issued from the control unit to the image forming apparatus main body, and the image forming operation of the system is stopped.

  FIG. 2 is an enlarged cross-sectional view of a main part extracted from the main part of the sheet post-processing apparatus according to the present embodiment shown in FIG. In the drawing, illustrations of members associated with the configuration of the present invention such as the jogger fence 24, the staple paper discharge sensor 18, the return roller 22 are omitted.

  FIG. 3 is a perspective view of the conveyance auxiliary flap 32 and its periphery in the sheet post-processing apparatus of the present embodiment.

  In this embodiment, as shown in FIGS. 2 and 3, one end is rotatably connected to a staple tray (temporary stacking tray) 14 on the same axis (reference numeral 44) as the discharge rollers 12 and 12 ′. Further, a conveyance auxiliary flap 32 configured to be pop-up at the other end is disposed. The conveyance assist flap 32 is provided with a home position (shown by a broken line in FIG. 2) HP positioned substantially parallel to the staple tray 14, rising from the home position HP, and receiving rollers 10, 10 ′ and discharge rollers 12, 12 ′. A guide position (illustrated by a solid line in FIG. 2) GP that is in a state of bridging at least a part between the two is rotated by driving means (not shown).

  FIG. 4 is a schematic diagram for explaining a drive mechanism of the conveyance assist flap 32. As shown in FIG. 4, outside the side plate (not shown), the motor 34 is used as a drive source, and the fan-shaped portion 36b of the fan-shaped gear 36 abuts on the rotating shaft 34a so that the rotational motion is propagated. The conveyance assisting flap 32 is moved to the home position (shown by a broken line in FIG. 4) HP and a guide by an arm 38 fixed to the central shaft 36b of the sector gear 36 and rotating in conjunction with the rotational drive of the sector gear 36. It is configured to rotate between a position (illustrated by a solid line in FIG. 4) GP.

  On the other hand, FIG. 5 is an enlarged cross-sectional view of a main part of the same portion as that shown in FIG. 2 in the conventional sheet post-processing apparatus. In FIG. 5, the conveyance auxiliary flap 32 characteristic of the present invention is not provided, and the other configuration is the same as that of FIG.

  In the conventional sheet post-processing apparatus shown in FIG. 5, in the staple processing execution mode in which the sheets P are temporarily stacked on the staple tray 14, the sheet P carried from the receiving rollers 10, 10 ′ is tapped and conveyed (loaded) by the rollers 16. Therefore, it is necessary to provide a wide space E between the receiving rollers 10 and 10 ′ and the discharging rollers 12 and 12 ′. Therefore, the region where the member that restricts the progress of the sheet P does not exist becomes long, and when the leading edge reaches the staple tray 14, it may be caught and rounded as shown in FIG.

  In the present embodiment, as shown in FIGS. 2 to 4, the conveyance assist flap 32 that is in the retracted state in the staple tray 14 at the home position HP rotates around the shaft 44 as the rotation axis at the guide position GP. , And appear at a position to bridge a part between the receiving rollers 10 and 10 ′ and the discharging rollers 12 and 12 ′. Therefore, the leading end of the sheet P in the conveyance (carrying-in) direction can be successfully transferred to the discharge rollers 12 and 12 '.

  Regarding the driving of the auxiliary conveyance flap 32, the user may move it in advance so as to be positioned at an appropriate position (in this case, the driving means may be manual). Although it is played, it is desirable to acquire the discharge mode in advance and control the driving of the auxiliary conveyance flap 32 by the flap control means accordingly.

  The discharge mode is the normal mode and the stapling execution mode (edge binding mode) as described above. This is selected by the user at the interface of the image forming apparatus main body or connected to the image forming apparatus main body. It is acquired as information by receiving a processed signal from the computer. Such information is acquired by using a computer provided in the image forming apparatus main body or the post-processing apparatus as an acquisition unit.

  Then, a computer as an acquisition unit, or a computer separately provided in the image forming apparatus main body or the post-processing apparatus is used as a flap control unit, and the drive unit (motor) is selected according to the discharge mode information acquired by the computer as the acquisition unit. 34) is controlled.

  When the discharge mode information acquired by the acquisition unit is “normal mode”, the flap control unit moves the drive auxiliary flap 32 from the home position HP to the guide position GP so that the driving unit (motor 34) rotates. Control the drive. This state is maintained as long as the normal mode sheet continues.

  As a result, when the sheet P carried by the receiving rollers 10 and 10 ′ is discharged to the discharging rollers 12 and 12 ′ as it is, as shown in FIG. 2, the raised and lowered conveyance assist flap 32 guides the delivery between them. Therefore, the front end of the sheet P in the conveyance (carry-in) direction can be stably sandwiched between the discharge rollers 12 and 12 ′, and good conveyance performance can be realized.

  On the other hand, when the discharge mode information acquired by the acquisition unit is “staple processing execution mode”, the leading end in the conveyance (carrying-in) direction of the sheet P conveyed from the receiving rollers 10 and 10 ′ contacts the conveyance auxiliary flap 32. Sometimes, the flap control means drives the drive means (motor 34) to rotationally move the conveyance auxiliary flap 32 from the home position HP to the guide position GP so that the conveyance auxiliary flap 32 is already at the guide position GP. Control.

  As a result, even when the sheets P carried by the receiving rollers 10 and 10 ′ are temporarily stacked on the staple tray 14, as shown in FIG. 2, the raised and lowered conveyance assist flap 32 guides the delivery between them. Therefore, the sheet P can be stably stacked in a region extending from the discharge rollers 12 and 12 ′ to the auxiliary conveyance flap 32. At this time, the upper surface of the sheet P is pressed downward by the hitting rollers 16 one by one.

  When the number of sheets P to be stacked is stacked, the flap control unit controls the driving of the driving unit (motor 34) so as to rotate the auxiliary conveyance flap 32 from the guide position GP to the home position HP. At the same time, the sheet roller P is abutted against the jogger fence 24 and the reference fence 26 by rotating the hitting roller 16 in the opposite direction to the conveying (carrying-in) direction. Next, as described above, the bundle of sheets P after the stapling process is held between the discharge rollers 12 and 12 ′ and is rotated to be discharged out of the apparatus (housing 40).

  As described above, even when the discharge mode information acquired by the acquisition unit is the “staple processing execution mode”, good transportability (especially when temporarily stacking on the staple tray 14) is realized. Can do.

  When the bundle of sheets P is discharged out of the apparatus (housing 40) after the stapling process is performed, not only the discharge rollers 12 and 12 ′ but also the tapping roller 16 advances to press down the bundle of sheets P. At the same time, it is preferable that the hitting roller 16 is configured to rotate in the same direction as the discharge rollers 12 and 12 ′ to assist the discharge of the bundle of sheets P.

[Second Embodiment]
FIG. 6 is an enlarged cross-sectional view of a main part extracted from the main part of the sheet post-processing apparatus according to the second embodiment which is an exemplary aspect of the present invention. Since the entire configuration is common to the first embodiment, refer to FIG.

  In the present embodiment, the distance between the nip of the receiving rollers 10 and 10 ′ (referring to a contact portion between the rollers, the same applies hereinafter) and the nip of the discharge rollers 12 and 12 ′ (when both rollers are in contact). However, the point which is longer than 1st Embodiment and the point from which the sheet | seat carried in from the outside is the Z fold sheet | seat Pz differ. Since all other configurations are the same as those in the first embodiment, members having the same function are denoted by the same reference numerals, and detailed description thereof is omitted.

  On the other hand, FIG. 7 is an enlarged cross-sectional view of the main part of the same part as the part shown in FIG.

  As shown in FIG. 7, when the Z-folded sheet Pz is loaded from the receiving rollers 10 and 10 ′ with the Z-folding side upstream in the transport direction, the Z-folded portion is positioned between the discharge rollers 12 and 12 ′. It becomes. Then, the upper surface of the Z-folded sheet Pz is pressed downward by the hitting roller 16, proceeds in the reverse direction by the rotation, and abuts against the reference fence 26 to be aligned.

  At this time, if the distance between the receiving rollers 10 and 10 ′ and the discharging rollers 12 and 12 ′ is too close, as shown in FIG. 7, the entire Z-folded portion once passes through the nip portion of the discharging rollers 12 and 12 ′. Therefore, when the tapping roller 16 is rotated (between the nip portions of the discharge rollers 12 and 12 ′ and may be rotated), the Z is moved in the reverse direction (direction toward the stapler 20). The folding part may be caught by the discharge rollers 12, 12 ′ and the end fence 48, which may cause a conveyance failure.

  In order to solve the above-mentioned conveyance trouble, for example, as described in Patent Document 1, if the space between the receiving rollers 10 and 10 ′ and the discharging rollers 12 and 12 ′ is set wide, a small size sheet is formed. When the paper is loaded into the post-processing apparatus and discharged directly to the paper discharge tray 28 without performing post-processing (that is, in the “normal mode”), the distance between the two becomes too long to be delivered, There was a possibility that it could not be transported.

  However, according to the configuration of the present embodiment, even if the gap between the receiving rollers 10 and 10 ′ and the discharge rollers 12 and 12 ′ is set wide as described above, as described in the section of the first embodiment, Since the transport assist flap 32 that appears and disappears guides the delivery between the two, good transportability can be realized even with a small-sized sheet (not shown).

  That is, when the discharge mode information acquired by the acquisition unit is the “normal mode” and the sheet to be carried in is a small size sheet, the conveyance assist flap 32 is rotated from the home position HP to the guide position GP. Thus, the flap control means controls the driving of the driving means (motor 34). This state is maintained as long as the normal mode sheet continues.

  As a result, when the small-size sheet carried by the receiving rollers 10 and 10 ′ is discharged to the discharge rollers 12 and 12 ′ as it is, the conveyed auxiliary flap 32 guides the delivery between the two, The leading end in the transport (carrying-in) direction can be stably sandwiched between the discharge rollers 12, 12 ′, and good transportability can be realized.

  On the other hand, the discharge mode information acquired by the acquisition unit is the “staple processing execution mode”, the sheet to be carried in is the Z-folded sheet Pz, and the receiving roller 10, When transported from 10 ′, the transport assisting flap 32 is already positioned at the guide position GP when the leading end of the sheet Pz transported from the receiving rollers 10 and 10 ′ contacts the transport assisting flap 32. As described above, the flap control means controls the drive of the drive means (motor 34) so as to rotate the conveyance auxiliary flap 32 from the home position HP to the guide position GP.

  As a result, even when the sheets P carried by the receiving rollers 10 and 10 ′ are temporarily stacked on the staple tray 14, as shown in FIG. 2, the raised and lowered conveyance assist flap 32 guides the delivery between them. Therefore, the sheet P can be stably stacked in a region extending from the discharge rollers 12 and 12 ′ to the auxiliary conveyance flap 32. At this time, the upper surface of the sheet P is pressed downward by the hitting rollers 16 one by one.

  In addition, in this embodiment, the distance between the nip of the receiving rollers 10 and 10 ′ and the nip of the discharge rollers 12 and 12 ′ (when both rollers are in contact) is sufficiently short. The entire portion does not once pass through the nip portion of the discharge rollers 12 and 12 ′, and there is no fear that the Z-folded portion is caught by the discharge rollers 12 and 12 ′ or the end fence 48. Therefore, the conveyance failure based on the Z-folded sheet Pz can be greatly reduced.

  When the number of sheets Pz to be stacked is stacked, the flap control unit controls the driving of the driving unit (motor 34) so as to rotate the auxiliary conveyance flap 32 from the guide position GP to the home position HP. At the same time, by rotating the hitting roller 16 in the direction opposite to the conveying (carrying-in) direction, the hitting roller 16 is abutted against the jogger fence 24 or the reference fence 26 to align the bundle of sheets Pz. Next, after the stapling process is performed, the paper is sandwiched between the paper discharge rollers 12 and 12 ′ and discharged out of the apparatus (housing 40).

  As described above, the discharge mode information acquired by the acquisition unit is the “staple processing execution mode”, the sheet to be carried in is the Z-fold sheet Pz, and the Z-fold side is received in the conveyance direction upstream. Even when it is carried in from the rollers 10 and 10 ', good transportability can be realized.

  The distance between the nip of the receiving rollers 10 and 10 ′ and the nip of the discharge rollers 12 and 12 ′ (when both rollers are in contact) is from the rear end of the Z-fold sheet Pz in the transport direction to the rear of the Z-fold region in the transport direction. It is set to be longer than the length to the end (the length of the short side of the region where the sheets do not overlap each other when the Z-folded sheet Pz is viewed in the sheet thickness direction; hereinafter referred to as “Z-folded outer length”). The Since the Z-fold sheet normally has a Z-fold outer length that is a quarter of the length in the longitudinal direction of the sheet, the Z-fold sheet can be set to be longer than a quarter of the length in the longitudinal direction of the Z-fold sheet that can be loaded. Good.

  For example, in a general image forming apparatus, the maximum size of the sheet is A3 size. In this case, the length of the A3 size in the longitudinal direction is 297 mm, so the nip of the receiving rollers 10 and 10 ′ and the discharge roller 12 , 12 ′ (when both rollers are in contact with each other) is set to a quarter of the distance of 74.25 mm or more. At this time, if there is a certain width in the nip, it is sufficient to obtain it based on the point that the sheet can be sandwiched with the least bite between the rolls, and it is preferable to use the center of the nip width as a reference.

  Of course, when the maximum size of the sheet is larger or smaller than A3, it is only necessary to obtain the maximum size sheet as a reference. In addition, when the Z-fold outer length is longer than a quarter of the length in the longitudinal direction of the Z-fold sheet, or when the Z-fold sheet is loaded in a short case, the Z-fold outer length is used as a reference. Find it.

[Third Embodiment]
FIG. 8 is an enlarged cross-sectional view of a main part extracted from the main part of the sheet post-processing apparatus according to the second embodiment which is an exemplary aspect of the present invention. Since the entire configuration is common to the first embodiment, refer to FIG.

  FIG. 9 is a perspective view of the conveyance assist flap and its surroundings in the sheet post-processing apparatus of this embodiment.

  In the present embodiment, the configuration of the conveyance assist flap 42 is different from the configuration of the conveyance assist flap 32 in the first embodiment. Moreover, the sheet Ps carried in from the outside is smaller than the sheet P in the first embodiment. Since all other configurations are the same as those in the first embodiment, members having the same function are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, a driven roller 46 that is driven by the rotation of the tapping roller 16 via the sheet P is disposed at a position on the auxiliary conveyance flap 42 located at the guide position GP when the tapping roller 16 advances. ing. Further, the hitting roller 16 is rotated not only in the reverse direction with respect to the transport (loading) direction but also in the reverse direction, that is, in the transport (loading) direction.

  When the discharge mode information acquired by the acquisition unit is “normal mode”, the flap control unit moves the drive auxiliary flap 32 from the home position HP to the guide position GP so that the driving unit (motor 34) rotates. Control the drive. In the conveyance auxiliary flap 42, a driven roller 46 is disposed at a position facing when the hitting roller 16 advances, a nip is formed between both rollers, and the sheet Ps inserted through the nip is driven to rotate the hitting roller 16. The driven roller 46 is in a state of being conveyed by the driven rotation. This state is maintained as long as the normal mode sheet continues.

  When the sheet Ps carried in by the receiving rollers 10 and 10 ′ is discharged as it is to the discharging rollers 12 and 12 ′, as shown in FIG. 8, the raised and lowered conveyance assist flap 32 guides the delivery between them, In the middle, the function of conveying the sheet Ps by the hitting roller 16 and the driven roller 46 appears, so that the delivery between the receiving rollers 10, 10 ′ and the discharging rollers 12, 12 ′ is performed stably, and the small size Even in the case of the sheet Ps, the leading end in the conveying (carrying-in) direction can be stably sandwiched between the discharge rollers 12 and 12 ′, and good conveying properties can be realized.

  Since the sheet post-processing apparatus of the present embodiment has good transportability of small-sized sheets in the “normal mode”, it is possible to set a wide space between the receiving rollers 10 and 10 ′ and the discharging rollers 12 and 12 ′. it can. Since it has a function of delivering the sheet Ps by the hitting roller 16 and the driven roller 46 between the receiving rollers 10, 10 ′ and the discharging rollers 12, 12 ′, the receiving rollers 10, 10 ′ are more than in the case of the second embodiment. The space between 10 'and the discharge rollers 12, 12' can be set wide.

  Accordingly, the discharge mode information acquired by the acquisition unit is the “staple processing execution mode”, the sheet to be carried in is a Z-folded sheet, and the receiving rollers 10, 10 with the Z-fold side upstream in the transport direction. Even in the case of being carried in from ', good transportability can be realized.

  In the present embodiment, a driven roller 46 that is driven by the rotation of the hitting roller 16 via the sheet P is disposed at a position on the auxiliary conveyance flap 42 that is positioned at the guide position GP when the hitting roller 16 advances. Although the example which is carried out was given, when the conveyance auxiliary | assistant flap 42 is located in the home position HP, the driven roller 46 may be distribute | arranged similarly to the position which opposes. However, in this case, not the sheet transportability in the “normal mode”, but contributes to the improvement of the transportability when stacking in the “staple processing execution mode” or when discharging the sheet or its bundle after executing the post-processing. become.

  Of course, it is most preferable that the follower roller 46 is disposed at the position where the conveyance assisting flap 42 is similarly opposed at any position of the guide position GP and the home position HP. This can be realized by making the positional relationship of the hitting roller 16 and the driven roller 46 and other members appropriate.

[Image forming apparatus]
The sheet post-processing apparatus of the present invention can be used by being attached to other various image forming apparatuses or by being incorporated in other image forming apparatuses. In this case, the entire apparatus including the sheet post-processing apparatus of the present invention corresponds to the “image forming apparatus” of the present invention. In this specification, the main body configuration of the image forming apparatus excluding the sheet post-processing apparatus of the present invention These parts are called “image forming apparatus main body” and are divided into concepts. In the present invention, the image forming apparatus main body is, for example, an electrophotographic digital multi-function peripheral, and is provided with a combination of functions such as a copy function, a printer function, and a facsimile function.

  Of course, in the present invention, the main body of the image forming apparatus is not limited to the electrophotographic digital multi-function peripheral, and may be various types of printers, copiers, and printing machines. The sheet post-processing apparatus of the present invention can be attached to or incorporated in any type of image forming apparatus.

  Although the present invention has been described with reference to the preferred embodiment, the sheet post-processing apparatus and the image forming apparatus of the present invention are not limited to the configuration of the above embodiment.

  A person skilled in the art can appropriately modify the sheet post-processing apparatus and the image forming apparatus of the present invention in accordance with conventionally known knowledge. Of course, such modifications are included in the scope of the present invention as long as the configuration of the sheet post-processing apparatus or the image forming apparatus of the present invention is provided.

2, 2 ': entrance roller 4: entrance sensor 6, 6': transport roller 8: transport guide 10, 10 ': receiving roller 12, 12': discharge roller 14: staple tray (temporary stacking tray)
16: Tapping roller 18: Staple discharge sensor 20: Stapler (post-processing means)
22: Return roller 24: Jogger fence 26: Reference fence 28: Paper discharge tray 30: Filler 32, 42: Conveyance auxiliary flap 34: Motor (drive means)
36: Fan-shaped gear 38: Arm 40: Housing 46: Follower roller 48: End fence

JP 2001-026345 A JP 2008-156074 A

Claims (9)

A pair of receiving rollers for receiving sheets from the outside into the receiving device, a temporary stacking tray disposed below the receiving rollers and temporarily stacking the loaded sheets, and stacked on the temporary stacking tray Post-processing means for performing post-processing on the sheets or a bundle thereof, and the sheets that are disposed downstream of the temporary stacking tray in the sheet loading direction and are loaded on the temporary stacking tray as they are In a sheet post-processing apparatus having a pair of discharge rollers for discharging the sheet or a bundle thereof out of the apparatus,
One end is rotatably connected to the temporary stacking tray in the vicinity of the discharge roller, and the other end is positioned in a state substantially parallel to the temporary stacking tray, the rising from the home position, the receiving roller and the A sheet post-processing apparatus comprising: a guide position positioned so as to bridge at least a portion between discharge rollers; and a conveyance assist flap that rotates between the guide positions. Furthermore, acquisition means for acquiring discharge mode information indicating a discharge mode of the sheet carried in from outside,
Driving means for driving the conveyance auxiliary flap to rotate between a home position and a guide position;
Flap control means for controlling the drive of the drive means according to the discharge mode information acquired by the acquisition means;
The sheet post-processing apparatus according to claim 1, further comprising:   When the discharge mode information acquired by the acquisition unit is a normal mode in which the loaded sheet is discharged as it is, the flap control unit drives the drive so as to rotate the conveyance assist flap from the home position to the guide position. The sheet post-processing apparatus according to claim 2, wherein the sheet post-processing apparatus is configured to control driving of the means.   When the discharge mode information acquired by the acquisition unit is in a post-processing execution mode in which post-processing is performed on the conveyed sheet, the leading edge of the sheet conveyed from the receiving roller is in contact with the conveyance assist flap. 4. The sheet post-processing apparatus according to claim 2, wherein the flap control unit controls the driving of the driving unit so that the conveyance auxiliary flap is positioned at the guide position. As the sheet received from the outside, including a Z-fold sheet conveyed with the Z-fold region forward in the conveyance direction,
The distance between the nip of the pair of receiving rollers and the nip of the pair of discharge rollers is set to be longer than the length from the rear end in the transport direction of the Z-folded sheet to the rear end in the transport direction of the Z-fold region. The sheet post-processing apparatus according to any one of claims 1 to 4.   Further, the sheet that has been carried in from the receiving roller is advanced so as to be pressed from above and pressed downward, and is rotated in a direction opposite to the loading direction by the receiving roller to place the sheet at a predetermined position on the temporary stacking tray. The sheet post-processing apparatus according to claim 2, further comprising a hitting roller to be fed. The sheet loaded on the temporary stacking tray after execution of post-processing by the post-processing means when the discharge mode information acquired by the acquisition means is in a post-processing execution mode for performing post-processing on the loaded sheet; When the bundle is discharged out of the apparatus by the discharge roller, the hitting roller advances and presses down the sheet or the bundle, and the hitting roller rotates in the same direction as the discharge roller and the sheet or the bundle thereof. The sheet post-processing apparatus according to claim 6, wherein discharging of the sheet is assisted.   The driven roller that is driven by the rotation of the hitting roller via the sheet or a bundle thereof is arranged at a position in the conveyance auxiliary flap that faces when the hitting roller advances. Or the sheet post-processing apparatus according to 7.   An image forming apparatus comprising the sheet post-processing apparatus according to claim 1.

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