JP2019147678A - Sheet post-processing device and image forming system - Google Patents

Abstract

To provide a sheet post-processing device that imparts a mark on a sheet being carried, which aligns a sheet imparted with the mark and the other sheet, and places the sheets on a discharge tray.SOLUTION: A sheet post-processing device B comprises: carrying mechanisms 24, 25 and 35 that carry a sheet 33 along a carrying passage 22; a sheet corner-folding mechanism 50 that corner-folds a corner part at a tip of the sheet being carried on the carrying passage toward one side of the sheet; a discharge tray 32 having a sheet placement surface 32a on which a sheet discharged from the carrying passage is placed; a carrying-out roller pair 25 that discharges the sheet from the carrying passage to the discharge tray; and a control part 200 that controls operation of the mechanisms, the tray and the pair. The control part, when the sheet corner-folded toward the sheet placement surface is discharged by the carrying-out roller pair to the discharge tray, controls a carrying roller driving motor 109 so that a speed of discharging the sheet is slower than a speed of discharging the other sheet.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a sheet post-processing apparatus that can give a mark to a sheet to be conveyed, and an image forming system including the sheet post-processing apparatus.

  Conventionally, after alignment processing, binding processing, folding processing, punch punching processing, stamp stamping processing, etc., for recorded paper ejected from image forming apparatuses such as copiers, laser beam printers, facsimiles, and multifunction peripherals thereof Paper post-processing devices that perform processing are widely used. In general, a sheet post-processing device is connected to a sheet discharge port of an image forming apparatus, and stacks a sheet or a bundle of sheets subjected to desired post-processing on a discharge tray disposed on the downstream side.

  There are cases where it is desired to sort a large number of sheets discharged from the image forming apparatus into a discharge tray in the sheet post-processing apparatus, for example, for each set of a plurality of sheets or each document. In view of this, there has been proposed a bookmark creation apparatus that creates a bookmark by cutting a corner of a cover page of a document (sheet bundle) to be sorted and bending the cut corner to protrude outside the sheet. (For example, see Patent Document 1)

  The bookmark creating apparatus of Patent Document 1 includes a mechanism for rotating a cam using a pulse motor and moving a cutter for cutting the paper with the cam, and temporarily stops the conveyed paper. Operate and cut the paper. After that, the pulse motor is operated again, the cutter is retracted, the paper conveyance is resumed, and the cut portion is folded outward using a conveyance roller arranged downstream.

  Furthermore, the bookmark creation apparatus of Patent Document 1 is configured to change the position for creating a bookmark for each document in order to make it easier to sort documents for a plurality of received documents. For this purpose, the control unit manages how many times the cover page is output, controls the conveyance motor that drives the conveyance roller of the recording sheet, and changes the stop position of the recording sheet in the processing device that moves the cutter up and down. ing.

JP-A-9-107433

  In the paper post-processing apparatus, when marks are added to the conveyed paper, it is preferable that the discharged paper is stacked in a state in which the discharged paper is aligned vertically and horizontally. However, as in the conventional apparatus described in Patent Document 1, when a mark is given by folding a part of a sheet to be conveyed, the folded sheet portion is another sheet that has been previously stacked on the discharge tray. There is a risk of being caught on the edge of other paper discharged later.

  In many discharge trays, the leading edge of the discharged paper lands ahead of the leading edge of the stacked paper, and is scraped by a rotating roller or the like in the direction opposite to the paper discharge direction. By bringing the end into contact with the regulating surface, the sheets are stacked in alignment in the paper discharge direction. For this reason, when there is a mark bent downward at the leading edge of the subsequent paper discharged to the discharge tray, the downward bent portion of the mark is highly likely to be caught on the leading edge of the previously loaded paper. There is a risk that the alignment of the paper in the paper discharge direction is impaired.

  As a result, there arises a problem that the sheets are stacked in the vertical and horizontal directions on the discharge tray. However, even if you look at Patent Document 1 and other conventional techniques, the specific technique for stacking a sheet with a mark by folding a part of the sheet and another sheet aligned in the discharge tray is as follows: There is no disclosure or suggestion.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to align a mark-added sheet with another sheet in a sheet post-processing apparatus that adds a mark to a sheet to be conveyed. It is to be loaded on the discharge tray.

  A further object of the present invention is to provide an image forming system that includes the above-described sheet post-processing apparatus of the present invention, and that marks the sheets discharged from the image forming apparatus and can stack them on the discharge tray together with other sheets. Is to provide.

The paper post-processing apparatus of the present invention is
A paper transport path for transporting paper,
A transport mechanism for transporting paper along the paper transport path;
A corner folding processing mechanism for corner-folding at least one corner of the leading edge of the sheet conveyed in the predetermined conveying direction by the conveying mechanism to one surface side of the sheet;
A paper discharge section for discharging paper from the paper transport path;
A paper discharge stacking unit having a paper loading surface for stacking paper discharged by the paper discharge unit;
A control unit for controlling operations of the transport mechanism, the corner folding processing mechanism, and the paper discharge unit;
The control unit is configured to set a discharge speed when discharging the folded paper, which is folded at the paper loading surface side of the discharge stacking unit, to the discharge stacking unit, and to set a sheet other than the square folded sheet to the discharge stack. The paper discharge section is operated so as to be slower than the discharge speed when discharging to the section.

  In another aspect of the present invention, an image forming system of the present invention includes an image forming unit that forms an image on a sheet, and a sheet post-processing device that performs a corner folding process on the sheet sent from the image forming unit. The processing apparatus is the paper post-processing apparatus of the present invention described above.

  According to the sheet post-processing apparatus of the present invention, the control unit operates the sheet discharge unit so that the discharge speed of the corner folded sheet is slower than that of the other sheets, so that the leading end of the corner folded sheet is loaded on the sheet. It is possible to land at a position not exceeding the leading edge of the uppermost sheet on the surface. As a result, there is no possibility that the corner folded portion of the discharged corner folded paper will be caught by the leading edge of the paper previously stacked on the paper discharge stacking portion, so that the paper can be stacked on the discharge tray with good alignment. .

1 is a diagram schematically showing an overall configuration of an image forming system. The side view which shows the structure of the principal part of the paper post-processing apparatus in the system of FIG. FIG. 3 is a schematic perspective view illustrating a configuration of a sheet corner folding mechanism of the sheet post-processing apparatus according to the present invention. FIG. 4 is a cross-sectional view illustrating a configuration of a sheet corner folding mechanism illustrated in FIG. 3. FIG. 4 is a top view illustrating a configuration of a sheet corner folding mechanism in FIG. 3. Sectional drawing which shows the corner folding operation | movement by the paper corner folding mechanism of FIG. 3 in order. FIG. 4 is a top view sequentially illustrating a corner folding operation by the sheet corner folding mechanism of FIG. 3. FIG. 3 is a plan view schematically showing a configuration of an alignment mechanism. FIG. 4 is a schematic diagram illustrating a sheet discharging operation to a discharge tray. The schematic diagram explaining the inclination-angle adjustment operation | movement of a discharge tray. FIG. 6 is a schematic diagram for explaining the operation of a paper biasing unit when paper is discharged to a discharge tray. FIG. 3 is a block diagram illustrating a control configuration of a sheet post-processing apparatus. The flowchart explaining the setting of the corner folding instruction | indication in a user operation part. 9 is a flowchart for explaining a series of sheet conveyance processes including corner folding processing.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Preferred embodiments of the invention will be described below with reference to the accompanying drawings.

[Image forming system]
FIG. 1 shows the overall configuration of an image forming system according to the present invention. The image forming system shown in FIG. 1 includes an image forming apparatus A and a sheet post-processing apparatus B. After the sheets formed by the image forming apparatus A are temporarily aligned and stored in the sheet post-processing apparatus B, after staple binding or the like. After processing, it is stored in the discharge tray. The paper post-processing apparatus B is configured to store the paper in the discharge tray after finishing processing according to the post-processing (finishing processing) mode set together with the image forming conditions in the image forming apparatus A. Hereinafter, the image forming apparatus A and the sheet post-processing apparatus B will be described.

[Image forming apparatus]
The image forming apparatus A shows a case where an image is formed on a sheet by an electrostatic printing mechanism, and is constituted by a paper feed unit 2, an image forming unit 3, and a paper discharge unit 4. The apparatus housing 1 of the image forming apparatus A includes a sheet feeding unit 2 that stores sheets for image formation. The sheet feeding unit 2 includes sheet feeding cassettes 2a, 2b, and 2c that are detachable from the apparatus housing 1. The paper feed cassettes 2a, 2b, and 2c correspond to different paper sizes.

  The image forming unit 3 forms an image according to the image data transferred from the data processing unit 9 onto the sheet conveyed from the sheet feeding unit 2. The illustrated image forming unit 3 shows an electrostatic printing mechanism, and includes a beam projector that forms an electrostatic latent image on the photosensitive drum 8, a developing unit 10 that attaches toner ink to the electrostatic latent image, a transfer charger 11, and a cleaner. It consists of Since these specific configurations and operations are widely known, detailed description thereof will be omitted.

  The image ink formed on the photosensitive drum 8 is transferred by the transfer charger 11 to the sheet conveyed from the sheet feeding unit 2 to the registration roller pair 7. A fixing roller pair 12 is disposed on the downstream side of the transfer charger 11, heat-fixes the transferred image, and conveys the paper to the paper discharge unit 4. The paper discharge unit 4 includes an image forming apparatus paper discharge port 13 disposed in the apparatus housing 1 and a paper discharge roller pair 15.

  The data processing unit 9 receives the image data read by the image reading unit 5 or the image data sent from an external network, a computer input device, etc. as an electrical signal to the beam projector according to the set image forming conditions. Send.

  The illustrated image forming apparatus A includes an image reading unit 5 integrated with the image forming apparatus A, and an automatic document sheet feeder 19 for feeding document sheets to the unit. The image reading unit 5 includes a platen 16 on which a document sheet is placed and a reading carriage 17 that moves along the platen 16. The document sheet on the platen 16 is scanned by the reading carriage 17 and converted into image data. It consists of a scanner device. Further, the automatic document sheet feeder 19 is integrally attached to the image reading unit 5 as a unit for automatically feeding document sheets set on the sheet feeding tray 20 to the platen 16.

  The duplex path 14 reverses the paper on which the image is formed from the image forming unit 3 and circulates and conveys the paper to the registration roller pair 7, forms an image on the back side of the paper with the image forming unit 3, and forms an image from the paper discharge unit 4. It is carried out to the apparatus discharge port 13.

  In addition to the electrostatic printing mechanism, the image forming apparatus A can employ various image forming mechanisms such as an inkjet image forming method, an offset printing method, and a silk printing method.

"Paper finishing device"
As shown in FIG. 1, the sheet post-processing apparatus B of the present invention, when an image-formed sheet is carried in from the image forming apparatus A, stores the sheet in a processing tray 29 and then finishes it after finishing. Processing (staple binding processing, folding processing, etc.) is performed, and the processed paper (or paper bundle) is stored in the discharge tray 32.

  FIG. 2 shows the configuration of the sheet post-processing apparatus B in detail. The sheet post-processing apparatus B includes an apparatus housing 21. In the apparatus housing 21, a conveyance path 22 that conveys the sheet, a sheet corner folding mechanism 50 that performs a corner folding process on the leading corner of the conveyed sheet, and a conveyance. The processing tray 29 temporarily stores sheets conveyed from the path 22 and a discharge tray 32 that stacks and stores post-processed sheets and can be moved up and down according to the amount of sheets stacked.

  Hereinafter, the sheet post-processing apparatus B according to the first embodiment of the present invention will be described in detail.

[Transport route]
The conveyance path 22 (paper conveyance path) is formed so as to cross the apparatus housing 21 in a straight line in a substantially horizontal direction. On the entrance side of the transport path 22, a transport port 101 connected to the image forming apparatus discharge port 13 is provided so as to guide the sheet transported from the image forming apparatus A toward the processing tray 29 on the downstream side. It is configured.

  In the transport path 22, a pair of carry-in rollers 24, a pair of transport rollers 35, and a pair of discharge rollers 25 constituting a paper transport unit are sequentially arranged on the upstream side and the downstream side along the paper transport direction. The carry-in roller pair 24, the carry roller pair 35, and the discharge roller pair 25 are connected to a carry roller drive motor 109 (not shown), which will be described later, and are driven by the carry roller drive motor to feed the paper from the carry-in port 101. It is conveyed toward the paper discharge port 103.

  Further, a carry-in sensor 23 is arranged on the carry path 22 on the carry-in entrance 101 side of the carry-in roller pair 24. When the carry-in sensor 23 detects the leading edge and the trailing edge of the paper conveyed from the carry-in port 101, the carry-in sensor 23 transmits a detection signal to the control CPU 203 incorporated in the control unit 200 of the paper post-processing apparatus B described later.

"Paper folding mechanism"
The sheet corner folding mechanism 50 is positioned between the carry-in roller pair 24 and the transport roller pair 35 on the transport path 22, and performs a later-described corner folding process on the sheet 33 transported through the transport path 22. 3 is a perspective view of the sheet corner folding mechanism 50, FIG. 4 is a sectional view thereof, and FIG. 5 is a top view thereof.

  The sheet corner folding mechanism 50 includes upper and lower flappers 51 and 52, upper and lower sheet guides 53 and 54, and a pair of folding rollers 55. As shown in FIG. 4, the upper and lower flappers 51 and 52 and the upper and lower paper guides 53 and 54 are provided vertically symmetrically with respect to the transport path 22.

  As shown in FIGS. 3 and 4, the transport path 22 is limited by a narrow gap in the up and down direction on the upstream side in the paper transport direction with respect to the folding roller pair 55 except for the upper and lower paper guides 53 and 54. ing. Due to this gap, the leading edge of the sheet 33 being conveyed in the conveyance path 22 does not change to the outside of the conveyance path, that is, does not change in the vertical direction (upward or downward) with respect to the surface of the sheet 33. It is configured.

  In the gap of the conveyance path 22, the portions where the upper and lower paper guides 53 and 54 are provided are cut out, respectively, from the first side parallel to the paper conveyance direction and the upstream side of the first side in the paper conveyance direction. A second side extending outward to the side of the transport path 22 in parallel with the paper width direction, and a downstream end in the paper transport direction of the first side and an outer end in the paper width direction of the second side are connected in an oblique straight line. A triangular opening composed of the third side is formed. The upper and lower paper guides 53 and 54 project outward from the triangular opening so as to close the triangular opening of the transport path 22.

  As shown in FIGS. 3 to 5, the upper sheet guide 53 is erected from the first side and the second side of the triangular opening to the outside of the conveyance path 22 and slightly inclined to the inside of the triangle. The flat and substantially fan-shaped first and second wall portions, and the substantially triangular third wall portion curved from the third side to the outside of the conveyance path 22 and curved to the inside of the triangle. The first and second wall portions are integrally coupled with the first side and the second side at a straight side extending from the intersection, and the third wall portion has both sides on the first and first sides. The two wall portions are integrally coupled to the substantially fan-shaped curved side.

  As a result, a sealed space for bending the corner of the sheet to the outside of the transport path 22 is defined inside the upper sheet guide 53 as will be described later. The inclination angle of the corner fold formed at the corner of the sheet 33 is determined by the third side of the triangle forming the third wall of the upper sheet guide 53. Since the lower paper guide 54 is provided vertically symmetrically with the upper paper guide 53, description thereof is omitted.

  The upper flapper 51 and the lower flapper 52 are each formed of a rectangular flat plate member having the same size and shape, and project from the second side of the triangular opening above and below the conveyance path 22 so as to be within the opening. The upper and lower flappers 51 and 52 are respectively outwardly with respect to the transport path 22 around the sheet width direction, ie, upward and downward in the vertical direction, at or near the second sides of the triangular openings above and below the transport path 22. The upper and lower paper guides 53 and 54 are supported so as to swing within the space defined by the upper and lower paper guides 53 and 54.

  The upper and lower flappers 51 and 52 change the corner of the sheet 33 conveyed at a position overlapping with the upper and lower flappers to the outside in the conveying direction (vertically upward or downward), that is, the sheet corner guiding means (first step). 1 guiding means). The upper and lower paper guides 53 and 54 are paper corners for curling the corners of the paper 33 turned to the outside in the transport direction by the upper and lower flappers 51 and 52 inwardly, that is, the paper side. It has a function as a part guide means (second guide means). As will be described later, the corner portion of the sheet 33 to be subjected to corner folding is bent as shown in FIGS. 4 and 5 by the combination of the upper and lower flappers and the upper and lower sheet guides.

  A folding roller pair 55 is provided adjacent to the upstream end of the transport path 22 and the downstream end of the lower paper guides 53 and 54 in the paper transport direction as a corner folding means for folding the corner of the paper 33 bent in this way. It has been. As shown in FIG. 5, the pair of folding rollers 55 has a length, that is, a dimension in the sheet width direction, that is larger than the width of the corner folding portion applied to the sheet 33 to be conveyed. It arrange | positions so that the whole folding part may be press-contacted.

  The pair of folding rollers 55 is provided only at positions corresponding to the corners of the sheet to be subjected to the corner folding process in the sheet width direction. For this reason, if the folding roller pair 55 is set so that the same sheet conveying force as that of the carry-in roller pair 24 or the discharge roller pair 25 can be exerted between the upper and lower folding rollers, a skew is caused in the conveyed sheet 33. There is a risk of generating. Therefore, the folding roller pair 55 is set such that the sheet conveying force is smaller than that of the carry-in roller pair 24 and the discharge roller pair 25.

  The folding roller pair 55 of this embodiment is driven by the same drive source (drive motor) as the carry-in roller pair 24, but is configured to be driven by the same drive source (drive motor) as the discharge roller pair 25. You can also. In the present embodiment, as the corner folding means, the folding roller pair 55 composed of the upper and lower roller pairs similar to the carry-in roller pair 24 or the discharge roller pair 25 is employed, but other corner folding means are also possible. For example, a configuration such as a pair of driven rollers having a gap narrow enough to form a corner fold, or a pair of curved guides having a narrow gap, although the corners of the bent paper are not pressed against each other. In these cases, the corner folding means can be set so as not to have a sheet conveying force.

  Next, a corner folding operation by the sheet corner folding mechanism 50 will be described. FIG. 6 is a view in which the corners of the paper 33 being transported along the transport path 22 is folded upward by the paper corner folding mechanism 50, that is, the process of forming the upward corner folds is viewed in order from the cross-sectional direction. FIG. 7 is a view of these processes as viewed from above.

  The sheet 33 carried into the sheet post-processing apparatus B is conveyed toward the sheet corner folding mechanism 50 by the pair of carry-in rollers 24 on the conveyance path 22. At that time, the conveyance position of the sheet 33 is confirmed by the carry-in sensor 23 detecting the leading edge and the trailing edge of the sheet.

  When the sheet 33 is not subjected to the corner folding process, the upper flapper 51 and the lower flapper 52 are maintained at the same height as the transport path 22, that is, horizontally in the present embodiment, as shown in FIGS. Accordingly, the sheet 33 passes through the pair of folding rollers 55 as it is in the normal sheet conveyance without being bent or bent at the corners of the conveyance path 22. Whether or not the sheet 33 is subjected to the corner folding process is determined by the presence or absence of an instruction from the main body control unit 202 provided in the image forming apparatus A, as will be described later.

  When the main body control unit 202 gives an instruction for the upper folding process at the corner, the upper flapper 51 and the lower flapper 52 are swung upward to a predetermined angular position as shown in FIGS. 6B and 7B. As a result, as shown in FIGS. 6B and 7B, the corner portion of the paper sheet 33 that is being conveyed is turned so as to bend upward while being conveyed. Be guided to. At this time, the upper flapper 51 and the lower flapper 52 are swung while maintaining the path width of the transport path 22 so that the corner of the sheet 33 can be easily guided into the upper sheet guide 53.

  As shown in FIGS. 6C and 7C, the corner portion of the sheet 33 that is turned upward and guided into the upper sheet guide 53 is moved upward as the sheet 33 continues to be conveyed in the sheet conveying direction. Along the curved surface of the third wall portion of the paper guide 53, the paper guide 53 is bent inwardly, that is, curled and bent toward the paper side. The upper and lower flappers 51 and 52 are returned to the original horizontal position after the corner of the paper 33 reaches the upper paper guide 53 and before the leading edge of the paper reaches the nip position of the pair of folding rollers 55.

  The sheet 33 is conveyed on the conveyance path 22 toward the folding roller pair 55 as it is, with the corners being bent as described above. As a result, the bent corner of the sheet 33 is sandwiched between the folding rollers of the pair of folding rollers 55 and conveyed while being pressed and pressed from above and below. As a result, as shown in FIGS. 6D and 7D, an upward folding process is performed at the corners of the sheet 33 to form an upward corner folding part.

  When the main body control unit 202 gives an instruction for the downward folding process at the corner, the upper flapper 51 and the lower flapper 52 are swung downward to a predetermined angular position. As a result, the corner portion of the sheet 33 is turned downward, guided into the lower sheet guide 54, and bent downward. The corner portion of the sheet 33 bent downward is processed in the same manner as the above-described upper folding process of the corner portion, and is pressed by the pair of folding rollers 55 to form a downward corner folding portion.

  The sheet 33 that has been subjected to the corner folding process is transferred to the transport roller pair 35 and the discharge roller pair 25, transported, and discharged to the discharge tray 32. At this time, if the corner portion of the paper 33 is folded and conveyed by the conveyance roller pair 35 and / or the discharge roller pair 25, the corner fold portion is pressed against the discharge roller pair 25. This is advantageous because it can be further folded and the corner folds can be formed more reliably. For example, the length of the conveyance roller pair 35 and / or the discharge roller pair 25 arranged on the sheet angle folding mechanism 50 side in the sheet width direction of the conveyance path 22 is made longer than usual, or the conveyance roller pair 35 or An additional pair of conveyance rollers is arranged on the sheet corner folding mechanism 50 side in the sheet width direction of the conveyance path 22, and the corner portion of the sheet 33 subjected to corner folding processing by the sheet corner folding mechanism is nipped between these roller pairs. This is achieved by configuring to be conveyed.

  In this embodiment, the upper flapper 51 and the lower flapper 52 are used as the sheet corner portion guiding means (first guiding means) for turning the corner portion of the sheet to the outside of the conveyance path 22. It is not limited to. Various configurations different from the upper and lower flappers 51 and 52 are conceivable as long as the corners of the sheet 33 being conveyed can be bent upward or downward from the conveyance path 22.

  For example, a flexible and highly durable resin sheet member made of PET (polyethylene terephthalate) or the like is inclined at an angle of at least one of upward and downward at an angle, and the upper and lower paper guides 53 and 54 described above. It is also possible to provide the second side of the triangular opening with a fixed inclination angle, or to provide a fixed projection or the like having a shape that changes the end of the sheet in the middle of the conveyance path 22. When these fixed turning means are used, the corners of the paper passing through the position of the turning means are always subjected to corner folding processing. It is preferable to shift the transport position in the paper width direction so as not to pass.

  In the present embodiment, one sheet corner folding mechanism 50 is provided in the conveyance path 22 so that only one corner of the sheet is folded. In another embodiment, two sheet corner folding mechanisms 50 can be provided in the width direction of the conveyance path 22. In this case, both the sheet folding mechanisms 50 are configured to be bilaterally symmetric with respect to the sheet conveyance direction, and the third wall portions of the upper and lower sheet guides 53 and 54 have curved surfaces that are curved with respect to the width of the conveyance path 22. Arranged to face each other. As a result, both corners on the leading end side of the sheet or one of the corners can be selectively subjected to corner folding.

"Processing tray"
A processing tray 29 is disposed on the downstream side of the paper discharge port 103. The processing tray 29 includes a processing tray paper mounting table 29a that supports the rear end portion in the paper discharge direction (the direction from right to left in FIG. 2). The processing tray paper mount 29a is disposed so as to bridge-support the paper conveyed from the paper discharge outlet 103 to the discharge tray 32 in a substantially horizontal direction.

  The processing tray 29 is provided with a restriction stopper 105 and a staple unit 31 for restricting the position of the rear end portion in the paper discharge direction. Therefore, the paper discharged from the transport path 22 is reversely transported in the direction opposite to the discharge direction (rightward in FIG. 2) and stored in the processing tray 29 disposed below the paper discharge port 103. . The staple unit 31 is a well-known unit that has been conventionally used, and binds a bundle of sheets stacked and aligned on the processing tray paper platform 29a by reverse conveyance with a staple.

"Alignment mechanism"
As shown in FIG. 2, the processing tray 29 has an alignment mechanism 30 that is an alignment unit that moves forward and backward in the sheet width direction of the sheet conveyed from the sheet discharge outlet 103 in a direction perpendicular to the sheet conveyance direction. Is arranged. As shown in the top view of FIG. 8, the alignment mechanism 30 aligns the left edge of the paper on the processing tray 29 in order to perform alignment with reference to the center of the paper 33 carried into the processing tray 29 from the paper discharge outlet 103. And a right alignment plate 30R engaged with the right edge of the paper.

  The left and right alignment plates 30L and 30R are fitted and supported in guide grooves (not shown) formed in the processing tray paper mount 29a of the processing tray 29, respectively, and are oriented in a direction orthogonal to the paper transport direction (hereinafter, “ It can be slid and moved in the “paper width direction”. A pair of pulley pairs 111 is arranged along the guide groove on the bottom of the processing tray 29, and a belt 112 is stretched over each pulley pair 111. The left and right alignment plates 30L and 30R are fixed to each belt 112, respectively. Also, shift motors MZ1 and MZ2 are connected to one pulley of each pulley pair 111.

  The left alignment plate 30L and the right alignment plate 30R, which are formed as a pair of left and right in such a configuration, reciprocate in the paper width direction by driving the alignment plate L shift motor MZ1 and the alignment plate R shift motor MZ2. At this time, the alignment plate L shift motor MZ1 and the alignment plate R shift motor MZ2 are synchronized and driven to rotate in the opposite direction by the same amount, so that the sheets carried on the processing tray 29 can be aligned based on the center reference. Become.

"Paper carry-out mechanism"
In the processing tray 29 described above, a pair of reverse rollers 28 that conveys the paper from the paper discharge outlet 103 onto the processing tray paper mounting table 29 a and a scraping roller 104 that sends the paper on the processing tray paper mounting table 29 a to the restriction stopper 105. Is arranged. The reversing roller pair 28 is constituted by a forward / reverse roller that transports the paper sent from the paper discharge port 103 in the reverse transport direction toward the regulation stopper 105 different from the discharge direction after transporting the paper once in the discharge direction. The illustrated reverse roller pair 28 includes a reverse upper roller 28 a positioned above the processing tray 29 and a reverse lower roller 28 b positioned below, and both rollers are configured as a pair of rollers that are pressed against and separated from each other.

  The reverse lower roller 28b has a fixed roller structure embedded in the processing tray paper mount 29a, whereas the reverse upper roller 28a is configured to be movable up and down in the post-processing device housing 21. The reversing upper roller 28 a is attached to a lifting arm that is pivotally supported by the post-processing device housing 21. An actuator such as a solenoid or a motor is connected to the elevating arm to elevate the elevating arm. A reversing roller driving motor 108 (not shown) that can be rotated forward and backward is connected to the reversing upper roller 28a in order to rotate it in the discharging direction and the reversing conveyance direction.

  A control CPU 203 (described later) positions the reversing upper roller 28a at a separated ascending position until the paper leading edge reaches the roller nip position of the reversing roller pair 28 after receiving the paper leading edge detection signal from the paper discharge sensor 102. After the leading edge of the paper reaches the roller nip position, the reverse upper roller 28a is lowered to the operating position where it presses against the reverse lower roller 28b. The reverse upper roller 28a is rotated in the discharge direction until the rear end of the paper is carried out from the paper discharge port 103, and is temporarily stopped and then rotated in the reverse conveyance direction. As a result, the paper discharged from the paper discharge path 22 is first sent in the discharge direction, and the rear end of the paper enters the processing tray 29 from the paper discharge port 103 and then advances in the reverse conveyance direction.

  That is, the control CPU 203, which will be described later, detects the upper end of the reversing upper roller 28a waiting upward at the timing when the front end of the sheet reaches the roller nip position of the pair of reversing rollers 28 after the paper discharge sensor 102 detects the front end of the sheet. And then temporarily stopped after a predetermined amount of rotation in the discharging direction in a state of being pressed against the reverse lower roller 28b, and then rotated in the reverse conveyance direction. In this control, a delay circuit is configured on the basis of a signal for detecting the leading edge of the paper by the paper discharge sensor 102 and a signal for detecting the trailing edge of the paper.

  The take-in roller 104 is constituted by a belt member (not shown) that rotates integrally with the discharge roller pair 25 of the discharge port 103, and hangs down from the discharge roller pair 25 on the uppermost sheet on the processing tray paper mount 29a. Are arranged as follows. The take-in roller 104 rotates in the same direction as the discharge roller pair 25, and applies a conveying force toward the restriction stopper 105 to the paper on the processing tray paper mounting table 29a. The scraping roller 104 is not limited to the rotating belt member, and various mechanisms such as a roller structure that swings up and down and a paddle structure can be employed.

"Eject tray"
The discharge tray 32 is configured with a storage structure having a discharge tray paper mounting surface 32a for stacking and storing paper, and a paper end regulating surface 32b for controlling the end of the paper stacked on the discharge tray paper mounting surface 32a. (See FIG. 2). The discharge tray 32 is arranged such that the discharge tray paper placement surface 32a has a predetermined height distance downward from the paper discharge position (reverse roller pair 28) on the paper end regulating surface 32b at the upstream end in the discharge direction. The discharge tray 32 is provided with the above-described already loaded paper presence / absence sensor 116 (not shown) in order to detect the presence / absence of already loaded paper on the discharge tray 32.

  The discharge tray paper placement surface 32a has a lifting tray structure that moves up and down. As shown in FIG. 2, a guide rail 106 extending in the vertical direction is provided on the side of the post-processing device housing 21 where the discharge tray 32 is disposed. On the guide rail 106, a tray mounting base 32c, to which the discharge tray 32 is fixed integrally, is attached so as to be movable in the vertical direction while being guided by the guide rail.

  For example, a pulling member such as a belt or a wire wound between upper and lower pulleys is coupled to the tray mounting table 32c. The discharge tray 32 can be moved to a desired height position by rotating the upper pulley forward and backward by a discharge tray lifting / lowering motor 118 (not shown), which will be described later, and feeding or winding up the pulling member.

  As shown in FIG. 2, the discharge tray paper mounting surface 32 a is inclined so as to increase from the upstream side in the discharge direction (the post-processing device housing 21 side) toward the downstream side. The sheet discharged to the discharge tray 32 first hangs down and lands on the discharge tray paper mounting surface 32a, and is entirely fed out from the pair of reverse rollers 28, from the paper end regulating surface 32b of the discharge tray paper mounting surface. Fall forward. The paper that has fallen on the discharge tray paper mounting surface 32a slides down the discharge tray paper mounting surface 32a along the inclination, and stops by hitting the paper end regulating surface 32b.

  The inclination angle of the discharge tray paper mounting surface 32a with respect to the horizontal plane is normally set to approximately 40 ° or more, but can be changed according to the type of paper loaded on the discharge tray 32, for example, set to 35 ° or more. . Generally, when the inclination angle is increased, the paper slides down on the discharge tray paper mounting surface 32a at a high speed, and when it is reduced, the paper slides gently. Therefore, by setting the inclination angle large, the sheets are more quickly stacked on the discharge tray sheet mounting surface 32a, and the overall size of the sheet post-processing apparatus B is reduced in the sheet conveyance direction (left and right direction in the figure). be able to.

  In another embodiment, it is possible to provide an approaching roller for bringing the paper discharged to the discharge tray 32 downward toward the paper edge regulating surface 32b. The advancing roller is disposed above the discharge tray paper mounting surface 32a, for example, at a position close to the paper edge regulating surface 32b, and comes into contact with the upper surface of the paper discharged to the discharge tray 32 so as to feed the paper downward. Rotate. Thereby, the paper on the discharge tray paper mounting surface 32a can be aligned more reliably and satisfactorily by aligning the paper in the direction opposite to the discharge direction of the paper sent from the reverse roller pair 28 to the discharge tray 32.

  As described above, when discharging the succeeding sheet folded down on the discharge tray 32 on which the preceding sheet is stacked, if the leading end of the preceding sheet exceeds the leading end of the preceding sheet and lands on the downstream side in the discharging direction, the discharging direction When the succeeding sheet is scraped toward the upstream side in order to align it with the preceding sheet in the opposite direction, the downward corner folding portion of the leading end is caught on the leading end side of the preceding sheet. The problem that it is not possible arises. Therefore, the sheet post-processing apparatus B according to the present embodiment sets the sheet landing position at a normal position so that the leading end of the sheet does not exceed the leading end of the preceding sheet when the sheet folded downward at the corner is discharged to the discharge tray 32. An adjustment mechanism is provided on the upstream side of the paper.

  In order to grasp in advance which sheet to be discharged to the discharge tray 32 is folded downward, the control unit 200, as will be described later, controls the sheets that have been discharged to the discharge tray 32 and have already been discharged. A corner folding state storage unit 203k that stores the corner folding state is provided. The corner folding state storage unit 203k is non-volatile so that the control can be continued without losing the corner folding state information stored therein, for example, when the sheet post-processing apparatus B is restarted or when it is recovered from unexpected power loss. It is preferable that the memory is composed of a memory.

  The control unit 200 acquires the corner folding state information of the sheet from the corner folding state storage unit 203k before the sheet is carried from the image forming apparatus A to the sheet post-processing apparatus B. As a result, a sheet landing position adjusting mechanism described below is operated on a sheet that is folded downward at the time of being discharged to the discharge tray 32.

  When there is no sheet loaded in the discharge tray 32 first, even when the sheet folded downward is discharged, it is not necessary to operate the sheet landing position adjusting mechanism. When the control unit 200 detects from the detection signal from the loaded paper presence / absence sensor 116 that there is no sheet stacked on the discharge tray 32, the control unit 200 acquires the corner folding state information from the corner folding state storage unit 203k. The paper can be discharged as usual.

  Further, in the following description relating to the adjustment of the paper landing position, the processing tray 29, the aligning mechanism 30, the staple unit 31, A configuration for binding sheets such as the reversing roller pair 28 for stacking the sheets on the processing tray is omitted, and the sheet is directly discharged from the discharge roller pair 25 to the discharge tray 32. When this is applied to the configuration of FIG. 2, unless otherwise specified, the discharge roller pair 25 in the following description may be read as the reverse roller pair 28, whereby the same operation and control are performed, and the same action is performed. It is understood that an effect can be obtained.

“Adjusting the paper discharge speed”
As the paper landing position adjusting mechanism, the control unit 200 according to the present embodiment adjusts to reduce the discharge speed for discharging the paper folded in a downward direction to the discharge tray 32 so as to be slower than the discharge speed of other paper. It has a function. The paper discharge speed is reduced by controlling the rotation of the conveyance roller drive motor 109 that drives the discharge roller pair 25 that discharges the paper from the conveyance path 22 to the discharge tray 32.

  The discharge speed may be reduced so that the entire length is discharged at the same low speed in the paper discharge direction, or the discharge speed is gradually reduced over the entire length or partly from the leading edge toward the trailing edge. You can also Furthermore, it is also possible to decelerate only when the trailing edge of the sheet is discharged from the discharge port 103 or slightly before that. In any case, the paper landing position is set to the normal level by making the discharge speed when at least the rear end of the paper is sent out from the paper discharge port 103 in this way slower than the discharge speed normally applied to other paper. It is possible to move to the near side, that is, to the upstream side in the discharge direction, and discharge the sheet so that the leading edge does not exceed the leading edge of the previously loaded paper.

“Adjusting the height of the discharge tray paper surface”
As another adjustment mechanism for the paper landing position, the control unit 200, as shown in FIG. 9, when discharging the paper 33 that is folded downward downward to the discharge tray 32, the paper placement surface of the paper discharge tray 32 in advance. An adjustment function is provided to raise the height position of 32a from a normal height position applied to other sheets to a predetermined upper position. The discharge tray paper mounting surface 32 a is raised by driving a discharge tray lifting / lowering motor 118 that lifts and lowers the tray mounting table 32 c along the guide rail 106.

  The predetermined upper position for raising the discharge tray 32 is set so that the height of the uppermost surface of the paper 40 stacked on the discharge tray paper placement surface 32 a is at least below the paper discharge port 103. For this purpose, the control unit 200 detects the height position of the uppermost surface based on a detection signal from a discharge tray paper surface position detection sensor 119 (not shown) described later in advance.

  Thus, by raising the paper loading surface 32a of the paper discharge tray 32, the paper 33 discharged from the paper discharge port 103 is surely placed in front of the normal height position, that is, before the paper discharge tray 32 is at the normal height position. It is possible to land on the uppermost sheet 40 at a position upstream in the discharge direction. The landed sheet 33 is fed forward, that is, downstream in the discharge direction by the discharge roller pair 25 while its lower surface is in contact with the upper surface of the sheet 40 until its rear end comes out from the sheet discharge port 103.

  At this time, the frictional resistance generated between the lower surface of the paper 33 and the upper surface of the paper 40 is larger than when the paper is discharged from the normal height position. By this frictional resistance, the sheet 33 can be stacked on the discharge tray 32 so that the leading end of the sheet that is bent downward is not beyond the leading end of the sheet 40, that is, the downstream end in the discharging direction. The frictional resistance varies depending on characteristics such as the size, rigidity, paper quality, and surface roughness of the paper 33. Therefore, it is preferable to set the predetermined upper position in consideration of these characteristics.

“Adjustment of the inclination angle of the paper tray surface”
As another adjustment mechanism for the paper landing position, as shown in FIG. 10, the controller 200 preloads the paper on the paper discharge tray 32 when discharging the paper 33 that is folded downward downward to the paper discharge tray 32. It has an adjustment function for enlarging the inclination angle of the surface 32a in comparison with the normal inclination angle applied to other sheets. The discharge tray 32 is rotatably supported at its base end by a support shaft 32d extending in the paper width direction. The inclination angle of the discharge tray 32 is, for example, a gear (not shown) fixed to the discharge tray 32 side. ) And a gear such as a worm provided on the apparatus housing 21 side, and a paper discharge tray rotation motor connected to the worm is driven by the control unit 200.

  In this way, by increasing the inclination angle of the paper discharge tray paper mounting surface 32a, the front end of the paper 33 discharged from the paper discharge outlet 103 is surely placed, and the paper discharge tray paper mounting surface 32a is at the normal inclination angle. It is possible to land on the uppermost sheet 40 at a position before the case, that is, at a position upstream of the discharge direction. The landed sheet 33 is fed forward, that is, downstream in the discharge direction by the discharge roller pair 25 while its lower surface is in contact with the upper surface of the sheet 40 until its rear end comes out from the sheet discharge port 103.

  At this time, the frictional resistance generated between the lower surface of the paper 33 and the upper surface of the paper 40 is larger than when the paper discharge tray paper mounting surface 32a is arranged at the normal inclination angle. By this frictional resistance, the sheet 33 can be stacked on the discharge tray 32 so that the leading end of the sheet that is bent downward is not beyond the leading end of the sheet 40, that is, the downstream end in the discharging direction. The enlarged inclination angle of the paper discharge tray paper loading surface 32a takes into consideration the size, rigidity, etc. of the paper 33 so that the leading edge thereof does not come into contact with the upper surface of the paper 40 and is not curled. It is preferable to set in consideration of the magnitude of the frictional resistance that varies depending on characteristics such as surface roughness.

  As described above, when the discharge speed of the paper 33 sent out from the discharge roller pair 25 is delayed, the trailing edge of the paper does not fall to the discharge tray paper placement surface 32a immediately after exiting the discharge port 103, and the discharge roller pair There is a risk that the outer peripheral surface of the 25 rollers and the paper end regulating surface 32b in the middle of the roller will lean. As described above, even when the discharge tray paper mounting surface 32a is raised and the inclination angle is increased, the friction resistance between the discharged paper 33 and the stacked paper 40 is large. A similar problem can occur. In order to solve this problem, the sheet post-processing apparatus B of the present embodiment forcibly biases the rear end of the sheet 33 that has exited the discharge port 103 toward the sheet end regulating surface 32b. It has.

“Paper deviation”
As shown in FIGS. 9 and 11, the paper biasing portion of the present embodiment includes a biasing member 42 disposed above the discharge roller pair 25 of the apparatus housing 21 and a biasing member driving portion 122 (not shown). Prepare. The biasing member 42 is provided so that the distal end portion 42b on the downstream side in the discharge direction can swing in the discharge direction with the base end portion 42a on the upstream side in the discharge direction as a rotation fulcrum. The biasing member 42 is driven by the biasing member driving unit 122, and as shown in FIG. 9, the upper standby position that does not prevent the paper discharge by the discharge roller pair 25 and the paper discharge port 103 as shown in FIG. The paper trailing edge immediately after coming out of the paper swings downward in the figure between a downward biasing position pushed toward the discharge tray paper mounting surface 32a. The biasing member driving unit 122 can be constituted by, for example, a drive motor connected to the base end portion of the biasing member 42 or an actuator including a solenoid and a return spring.

  For example, the control unit 200 detects the position of the biasing member 42 by a biasing member position detection sensor 123 provided near the base end of the biasing member 42, and detects the rear end position of the paper 33 by the paper discharge sensor 102. Then, the control unit 200 controls the biasing member driving unit 122 in synchronization with the timing at which the rear end of the sheet 33 exits the paper discharge port 103, and swings the biasing member 42 from the standby position to the biasing position. As a result, the rear end of the paper 33 discharged to the paper discharge tray 32 can be pushed downward by the tip of the biasing member 42 and reliably dropped onto the uppermost paper of the discharge tray paper mounting surface 32a. Thereafter, the control unit 200 returns the biasing member 42 from the biasing position to the standby position.

  The paper biasing portion is not limited to the one using the swingable biasing member 42 described above, and various known conventional techniques can be employed. For example, by arranging a downward nozzle above the discharge roller pair 25 toward the paper discharge port 103 and injecting an air flow from the downward nozzle to the rear edge of the paper that has exited the paper discharge port 103, the rear edge of the paper is similarly obtained. Can be pushed down and reliably dropped onto the uppermost sheet of the discharge tray sheet loading surface 32a.

  In another embodiment, the paper biasing unit can be operated in the same manner for not only the paper that is folded in a downward angle but also all the paper that is discharged from the paper discharge outlet 103 to the paper discharge tray 32. As a result, all the sheets post-processed in the sheet post-processing apparatus B can be stacked on the discharge tray 32 with good alignment.

  As described above, by delaying the discharge speed of the sheet 33 sent out from the discharge roller pair 25, the interval with the sheet conveyed immediately after the conveyance path 22 is narrowed, and the sheet 33 is still nipped by the discharge roller pair 25. There is a possibility of catching up and immediately colliding after exiting the sheet discharge outlet 103. In order to solve this problem, the sheet post-processing apparatus B according to the present embodiment has a function for adjusting the interval between the sheet conveyed on the conveyance path 22 immediately after the sheet 33 that is folded downward at the corner. Yes.

"Paper interval adjustment function"
The control unit 200 delays the timing at which the sheet immediately after the sheet 33 is carried from the image forming apparatus A to the sheet post-processing apparatus B when delaying the discharge speed of the sheet 33 folded downward to the discharge tray 32. As described above, it has a function of instructing the main body control unit 203 on the image forming apparatus A side. If it is not necessary to delay the discharge speed to the discharge tray 32 even if the sheet is folded at a downward angle, the control unit 200 issues an instruction to the main body control unit 203 to delay the timing at which the immediately subsequent sheet is carried. Absent. Accordingly, the interval between the sheet 33 folded in the downward direction and the subsequent sheet is suitably maintained, and the sheet 33 can be efficiently conveyed without being brought into contact with the sheet and stacked on the discharge tray 32.

  In another embodiment, the control unit 200 controls the transport roller drive motor 109 that drives the carry-in roller pair 24 and the transport roller pair 25 to slow down the paper transport speed in the transport path 22 or temporarily The conveyance can be stopped. Thereby, similarly, the interval between the sheet 33 and the immediately following sheet can be adjusted. In this case, it is preferable that the carry-in roller pair 24 and the carry roller pair 25 can be individually controlled with respect to the reduction in the carry speed and the carrying stop.

[Control configuration]
A control configuration of the sheet post-processing apparatus B of the present embodiment will be described with reference to the block diagram of FIG. The control unit 200 of the sheet post-processing apparatus B is connected to the main body control unit 202 of the image forming apparatus A, and the main body control unit 202 is connected to the user operation unit 201 that is also provided in the image forming apparatus A.

  The control unit 200 is computer-controlled by the control CPU 203, copies the control program data stored in the ROM 204 to the RAM 205, and controls the post-processing operation accordingly. In this post-processing operation, not only the corner folding process by the above-described sheet corner folding mechanism 50 but also the sheets stored in the processing tray 29 are accommodated for the sheet 33 that is carried into the sheet post-processing apparatus B and conveyed. The post-processing such as stapling is performed on the bundle, and the post-processed sheet bundle is discharged to the discharge tray 32.

  The control CPU 203 receives paper information (conveyance direction size, paper width direction size, basis weight, etc.), job start signal, and job end signal from the main body control unit 202 of the image forming apparatus A. Upon receiving these information and signals, the control CPU 203 controls the operation of the sheet post-processing apparatus B based on the control program data copied to the RAM 205.

  The control CPU 203 receives a sheet transported from the image forming apparatus A into the transport path 22 and transports it, a sheet alignment control unit 203b, a post-processing control unit 203c, a sheet bundle discharge control unit 203d, A corner folding control unit 203e that controls the sheet corner folding mechanism 50, a corner folding state storage unit 203k, a discharge tray control unit 203m, and a sheet bias control unit 203n are provided. Also in the above-described corner folding process, the control CPU 203 controls the corner folding process of the sheet post-processing apparatus B according to the control program data copied to the RAM 205.

  The transport control unit 203 a controls the transport roller drive motor 109 based on the detection signal of the transport sensor 23 in order to transport the paper transported from the transport inlet 101 through the transport path 22 and discharge it from the paper discharge port 103. Thus, the carry-in roller pair 24, the transport roller pair 35, and the discharge roller pair 25 are rotated. In the case of discharging the folded paper sheet to the discharge tray 32, the conveyance roller driving motor 109 is controlled to reduce the sheet discharge speed by the discharge roller pair 25. Further, in order to adjust the interval with the subsequent sheet, the conveyance roller drive motor 109 is similarly controlled to reduce the conveyance speed of the carry-in roller pair 24 and / or the conveyance roller pair 35 and temporarily stop the conveyance of the sheet. . Similarly, the pair of corner folding rollers 55 is also rotated so as to allow corner folding processing of the sheet corner by controlling the transport roller drive motor 109.

  When stacking the paper 33 transported along the transport path 22 on the processing tray 29, the transport control unit 203a causes the upper reversing roller 28a to stand by at a raised position separated from the reversing lower roller 28b, and the transported paper. After the leading end of 33 passes the nip position of the pair of reverse rollers 28, the reverse roller lift motor 110 is controlled so that the reverse upper roller 28a is lowered and pressed against the reverse lower roller 28b. Further, the reversing roller pair 28 rotates so as to convey the paper in the discharge direction until the rear end of the conveyed paper 33 passes through the paper discharge sensor 102, and when the paper discharge sensor 102 detects the rear edge of the paper, The paper is transported toward the regulating stopper 105 (in the direction opposite to the discharge direction) by once reversely rotating after stopping the rotation. The reverse roller pair 28 is rotated by controlling the reverse roller drive motor 108.

  The sheet 33 conveyed toward the restriction stopper 105 by the reverse roller pair 28 is conveyed to the restriction stopper 105 by the scraping roller 104 and stacked on the processing tray 29. Similarly to the discharge roller pair 25, the take-in roller 104 is driven by a conveyance roller drive motor 109 controlled by the conveyance control unit 203a.

  When the paper 33 is discharged from the paper discharge port 103 and is not directly stored in the processing tray 29 but is directly discharged to the discharge tray 32, the reversing upper roller 28a is kept in the raised position and is transported through the transport path 22. The reversing roller lifting motor 110 is controlled so that the reversing upper roller 28a is lowered and pressed against the reversing lower roller 28b after the leading edge of the paper 33 exiting the paper discharge port 103 and passes through the nip position of the reversing upper roller 28a. To do. Further, the reversing roller pair 28 is rotated in the discharging direction without temporarily stopping or reversely rotating, and the sheets are stacked on the discharge tray 32 from the discharge port 103.

  The sheet alignment control unit 203b operates the alignment plates 30R and 30L by controlling the driving of the alignment plate L shift motor MZ1 and the alignment plate R shift motor MZ2. This alignment operation is performed based on a trailing edge detection signal of the paper 33 conveyed by the paper discharge sensor 102. Further, the sheet alignment control unit 203b does not perform the alignment operation when the sheet 33 conveyed by the conveyance control unit 203a is directly discharged to the discharge tray 32.

  The post-processing control unit 203c controls the staple unit 31 when stapling a bundle of sheets. When the job end signal is received from the main body control unit 202, the post-processing control unit 203c is activated by the drive motor of the staple unit 31 after the last sheet is stored in the processing tray 29 and the sheet bundle is aligned in the sheet width direction. Send a signal. Upon receipt of this activation signal, the staple unit 31 executes a binding operation, and sends an end signal to the post-processing control unit 203c after the binding operation is completed. The post-processing control unit 203c receives the end signal, recognizes that the binding operation is completed, and notifies the sheet bundle discharge control unit 203d.

  Upon receipt of the binding operation completion notification from the post-processing control unit 203c, the sheet bundle discharge control unit 203d presses the sheet bundle on the processing tray 29 with the reverse roller pair 28 and conveys the sheet bundle in the direction of the discharge tray 32. Therefore, the reverse roller driving motor 108 is driven. By this operation, the sheet bundle on the processing tray 29 is conveyed and stacked on the discharge tray 32 on the downstream side.

  When the corner folding control unit 203e receives from the main body control unit 202 an instruction for corner folding processing (up-folding processing, down-folding processing, no processing) input by the user through the user operation unit 201, the paper corner control unit 203e responds to the instruction. The folding mechanism 50 is controlled. When the corner folding process is performed on the conveyed paper 33, the corner folding control unit 203 e controls the corner folding flapper motor 206 based on the detection signal at the leading edge of the sheet by the carry-in sensor 23, and the upper flapper 51 and the lower flapper 52. Is swung from the horizontal position. When the corner folding process is not performed, the corner folding control unit 203e does not control the sheet corner folding mechanism 50. Accordingly, the upper flapper 51 and the lower flapper 52 are maintained in the horizontal position.

  As described above, the corner folding state storage unit 203k stores the corner folding state information of the paper discharged to the discharge tray 32. This corner folding state information includes the sheet information (characteristics such as sheet dimensions and rigidity) input from the main body control unit 202 to the control unit 200 before being carried from the image forming apparatus A as a sheet to be folded at the corner. The output order of sheets to the sheet post-processing apparatus B, the setting of the corner folding process, and the like, and the state of the corner folding process of each sheet performed in the sheet post-processing apparatus B (the positions and corners of the corner folded corners) Fold direction, etc.).

  The discharge tray lifting / lowering control unit 203m determines the height position of the uppermost surface of the paper stacked on the discharge tray 32 based on the detection signal from the discharge tray paper surface position detection sensor 119 provided near the discharge tray 32. The height of the uppermost surface is a constant or constant range from the paper discharge position (the discharge port of the reverse roller pair 28 in FIG. 2 or the discharge port 103 in FIG. 8), that is, the height distance is constant or a constant range The discharge tray lifting / lowering motor 118 is controlled according to the sheet stacking height of the discharge tray 32. Further, the discharge tray lifting / lowering control unit 203m controls the discharge tray lifting / lowering motor 118 so as to raise the discharge tray 32 to the predetermined upper position when adjusting the paper landing position as described above.

  The sheet deviation control unit 203n is based on a corner folded state determined by the conveyance control unit 203a for the sheet discharged by the discharge roller pair 25 and a signal from the sheet discharge sensor 102 that detects the leading edge and / or the trailing edge of the sheet. Thus, the biasing member driving unit 122 that swings the biasing member 42 between the standby position and the biasing position is controlled. At this time, the sheet bias control unit 203n grasps the position of the bias member 42 based on the detection signal from the bias member position detection sensor 123.

  Further, the main body control unit 202 not only forms an image in the image forming apparatus A, but also instructs a corner folding process input from the user operation unit 201 in connection with a sheet corner folding process performed by the sheet post-processing apparatus B. Based on the detection signal from the already loaded paper presence / absence sensor 116 input via the control CPU 203, image formation on the paper and output of the paper to the paper post-processing apparatus B are controlled. Specifically, when the discharge speed of the sheet folded in the downward direction to the discharge tray 32 is reduced, the subsequent sheet is moved to the rear of the sheet in order to maintain an appropriate interval between the sheet and the subsequent sheet. The output of the paper is controlled so as to delay the discharge timing to the processing apparatus B. The sheet output control can be performed by the main body control unit 202 based on the corner folding setting input from the user operation unit 201, or in response to a request from the sheet post-processing apparatus B. Do it.

  In the following, a process of setting an instruction of the sheet corner folding process executed by the sheet corner folding mechanism 50 by the user operation unit 201 in the control configuration of the above-described embodiment will be described based on the flowchart of FIG.

  First, in step S101, it is determined whether or not the uppermost sheet of the discharge tray 32 has been subjected to a corner folding process. This determination is made based on the corner folding state information of the paper stored in the corner folding state storage unit 203k and the detection signal of the loaded paper presence / absence sensor 116. If the uppermost sheet has been folded upward, the process proceeds to step S102, and if not, the process proceeds to step S103.

  In the next step S102, a downward corner folding instruction for the first sheet is prohibited. This is to prevent the alignment of the paper from being impaired if the paper that is folded downward on the paper that is folded upward is discharged.

  If it is determined in step S101 that the uppermost sheet of the discharge tray 32 is not folded upward, an instruction for corner folding processing is accepted in step S103.

  In step S104, it is determined whether or not the input corner folding instruction is upward. If it is an upward corner folding instruction, the process proceeds to step S105, and if not, the process proceeds to step S106.

  In step S105, a downward corner folding instruction is prohibited for the sheet conveyed next to the sheet instructed to be folded in step S103. This is to prevent the alignment of the paper from being lost as in step S102.

  In step S106, it is determined whether or not there is an additional corner folding instruction from the user operation unit 201. If there is an additional corner folding instruction, the process proceeds to step S103, and if there is no corner folding instruction, the setting of the corner folding process is terminated.

  Further, a process of performing the corner folding process and the conveyance of the sheet based on the setting of the corner folding process input by the user operation unit 201 in the sheet post-processing apparatus B of the present embodiment will be described based on the flowchart of FIG. .

  In the first step S201, it is determined whether or not there is an instruction for the downward corner folding process on the paper carried from the image forming apparatus A to the paper post-processing apparatus B. This determination is performed by the main body control unit 202 of the image forming apparatus A. If there is an instruction for the downward corner folding process, the process proceeds to step S202, and if not, the process proceeds to step S203.

  In the next step S202, in the image forming apparatus A, the timing for outputting the sheet to the sheet post-processing apparatus B is delayed.

  In step S203, the paper is carried from the image forming apparatus A to the paper post-processing apparatus B. The sheet post-processing apparatus B receives the sheet discharged from the sheet discharge port 13 of the image forming apparatus A, detects the leading edge of the sheet by the carry-in sensor 23, and moves the conveyance path 22 downstream in the sheet conveyance direction by the carry-in roller pair 24. Transport.

  Next, in step S <b> 204, corner folding processing is performed on the paper 33 transported along the transport path 22. Based on the corner folding instruction set by the input from the user operation unit 201, the sheet 33 is subjected to the corner folding process with the sheet corner folding mechanism 50 upward or downward, or without being folded. Transport.

  In step S205, it is determined whether or not the conveyed paper sheet 33 is folded downward. If the corner is folded downward, the process proceeds to step S206; otherwise, the process proceeds to step S210.

  In step S <b> 206, the discharge tray 32 is raised from the normal height position to the predetermined upper position, and then the paper is discharged to the discharge tray 32. Landing the discharged paper upstream of normal, widening the contact area with the previously loaded paper and increasing the frictional resistance, the downward corner folds exceed the leading edge of the previous paper This is to prevent it from occurring.

  In step S207, immediately before the trailing edge of the paper being discharged to the discharge tray 32 comes out of the discharge roller pair 25, the discharge speed of the paper being discharged is decreased. As a result, the paper being discharged is discharged to the discharge tray 32 so that the corner folding portion does not exceed the downstream end of the already loaded paper. The timing for slowing down the discharge speed of the paper being discharged to the discharge tray 32 is when a predetermined time has elapsed since the paper discharge sensor 102 detected the leading edge of the paper being discharged. Based on the size of the paper being discharged, for example, based on the paper size information received from the image forming apparatus A.

  Further, in step S208, immediately after the trailing edge of the sheet is sent out from the discharge roller pair 25, the sheet biasing portion is driven. The bias member 42 is swung to the bias position, and the rear end of the sheet is pushed downward. As a result, the sheet is surely dropped onto the uppermost sheet of the discharge tray sheet loading surface 32a.

  In the next step S209, after the discharge of the paper to the discharge tray 32 is completed, the height position of the discharge tray 32 and the position of the biasing member 42 are returned to their original positions, and the discharge speed of the discharge roller pair 25 is further reduced. Return to speed.

  If the sheet 33 is not folded in the downward direction in step S205, it is determined in step S210 whether or not the uppermost sheet previously stacked on the discharge tray 32 has been folded in the upward direction. This determination is made based on the corner folding state information of the paper stored in the corner folding state storage unit 203k. If the corner is folded upward, the process proceeds to step S211; otherwise, the process proceeds to step S213.

  If the uppermost sheet of the discharge tray 32 is folded upward in step S210, the discharge tray lifting / lowering motor 118 is driven in step S211 to lower the discharge tray 32 below the normal height position. Thereafter, the next sheet is discharged to the discharge tray 32. As a result, the leading edge of the next sheet is landed at a position on the downstream side in the discharge direction beyond the upward corner fold of the uppermost sheet.

  Next, in step S212, the discharge tray lifting / lowering motor 118 is driven to raise the discharge tray 32 and return it to the normal height position.

  If it is determined in step S210 that there is no upwardly folded sheet on the uppermost surface of the discharge tray 32, in step S213, the next sheet conveyed on the conveyance path 22 is discharged as it is to the discharge tray 32 as usual. .

  In the next step S214, it is determined whether there is a sheet to be carried into the sheet post-processing apparatus B next. If there is a sheet to be carried next, the process proceeds to step S201, and if not, the sheet conveyance is terminated. Next, the control CPU 203 determines whether there is a sheet to be carried in based on a job end signal received from the main body control unit 202.

  As mentioned above, although this invention was demonstrated in relation to preferred embodiment, this invention is not limited to the said embodiment, In the technical scope, it can implement by adding various change or deformation | transformation. Needless to say. For example, the position of the sheet corner folding mechanism 50 is not limited to the position between the carry-in roller pair 24 and the transport roller pair 25, but the upstream side of the carry-in roller pair 24 or the transport roller pair 25 and the discharge roller pair 25. It is also possible to arrange them in between, or to arrange them coaxially with these roller pairs in the paper transport direction.

A image forming apparatus B sheet post-processing apparatus 21 apparatus housing 22 conveyance path 23 sheet carry-in sensor 24 carry-in roller pair 25 discharge roller pair 28 reversing roller pair 29 processing tray 32 discharge tray 33 sheet 35 conveyance roller pair 42 bias member 50 sheet corner folding Mechanism 51 Upper flapper 52 Lower flapper 53 Upper paper guide 54 Lower paper guide 55 Folding roller pair 101 Carry-in port 103 Paper discharge port 110 Reverse roller lifting / lowering motor 119 Discharge tray paper surface position detection sensor 122 Biasing member drive unit 123 Biasing member position detection sensor 201 User operation unit 202 Main body control unit 203 Control CPU
203a Conveyance control unit 203b Paper alignment control unit 203c Post-processing control unit 203d Paper bundle discharge control unit 203e Corner folding control unit 203k Corner folding state storage unit 203m Discharge tray lifting control unit 203n Paper deviation control unit

Claims (11)

A paper transport path for transporting paper,
A transport mechanism for transporting paper along the paper transport path;
A corner folding processing mechanism for corner-folding at least one corner of the leading edge of the sheet conveyed in the predetermined conveying direction by the conveying mechanism to one surface side of the sheet;
A paper discharge section for discharging paper from the paper transport path;
A paper discharge stacking unit having a paper loading surface for stacking paper discharged by the paper discharge unit;
A control unit for controlling operations of the transport mechanism, the corner folding processing mechanism, and the paper discharge unit;
The control unit is configured to set a discharge speed when discharging the folded paper, which is folded at the paper loading surface side of the discharge stacking unit, to the discharge stacking unit, and to set a sheet other than the square folded sheet to the discharge stack. A paper transporting apparatus, wherein the paper discharge unit is operated so as to be slower than a discharge speed at the time of discharging to the unit.   The control unit, when the corner folded paper is discharged to the paper discharge stacking unit, when the rear end of the paper is discharged, the discharge speed is slower than the discharge speed of the other paper, The paper post-processing apparatus according to claim 1, wherein the paper discharge unit is operated. An elevating unit for elevating the paper loading surface of the paper discharge stacking unit;
The said control part controls the said raising / lowering part so that the said paper mounting surface may be raised, before the said square folding paper is discharged | emitted by the said paper discharge stacking part. Paper post-processing equipment. A paper biasing portion for biasing a rear end of the paper discharged to the paper discharge stacking portion toward the paper loading surface;
The control unit controls the paper biasing unit so that the rear end of the sheet is biased toward the paper loading surface when the rear end of the corner folded paper is discharged from the paper transport path. The sheet post-processing apparatus according to claim 1, wherein the sheet post-processing apparatus is provided. An inclination angle adjusting unit for changing an inclination angle of the paper loading surface with respect to a discharge direction of the paper discharged from the paper conveyance path;
The controller adjusts the inclination angle adjustment unit so that the inclination angle of the paper loading surface is made larger than when other sheets are discharged before the corner folded paper is discharged to the paper discharge stacking unit. The sheet post-processing apparatus according to claim 1, wherein the sheet post-processing apparatus is controlled.   The control unit controls the transport mechanism so as to adjust an interval between the sheet and another sheet following the sheet when the square folded sheet is discharged to the discharge stacking unit. The sheet post-processing apparatus according to claim 1.   The control unit delays a timing of receiving another sheet following the sheet into the sheet conveyance path when the square folded sheet is discharged to the sheet discharge stacking unit. The paper post-processing apparatus according to any one of the above.   8. The control unit according to claim 1, wherein the control unit determines whether or not the sheet is discharged to the discharge stacking unit based on corner folding information stored in a memory. The paper post-processing device according to any one of the above.   The sheet post-processing apparatus according to claim 9, further comprising the memory.   The corner folding processing mechanism includes a sheet corner guiding section that causes at least one corner of the leading edge of the sheet conveyed along the sheet conveying path by the conveying mechanism to bend outward with respect to the conveying direction; and the sheet 10. A sheet corner fold processing section that presses the corner portion of the sheet that has been warped back while being conveyed in the conveyance direction by the conveyance mechanism, and folds the sheet corner. Paper post-processing equipment. An image forming unit for forming an image on paper;
A paper post-processing device that performs a corner folding process on the paper sent from the image forming unit,
The image forming system according to claim 1, wherein the sheet post-processing apparatus is the sheet post-processing apparatus according to claim 1.

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