JP2004284775A - Paper loading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a paper loading condition from becoming unstable due to swelling of staples even when papers are bound by staples and to avoid trouble caused by the occurrence of a clearance in a rear end part in the direction of paper conveyance of a tray when loading papers. <P>SOLUTION: This paper loading device is provided with a delivery tray delivering paper on which post-processing is applied in a loaded condition and a delivery means delivering paper on the delivery tray. A divided tray divided from a delivery tray body is provided in a rear end part in the direction of paper delivery of the delivery tray so as to turn or elevate and lower. A fixed tray is arranged below the divided tray. A recessed part and a projecting part for preventing paper from dropping by fitting mutually are provided in end guides arranged in rear end parts of the divided tray and the fixed tray and the rear end part of the delivery tray. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a paper stacking apparatus that stacks paper on which an image is formed by an image forming apparatus such as a copier, a printer, a facsimile, or a multifunction peripheral of the electrophotographic system, and more particularly, to a paper stack on which an image is formed. The present invention relates to a sheet stacking device suitably used in combination with a post-processing device that performs post-processing.
[0002]
[Patent Document 1] JP-A-2001-206613
[Patent Document 2] JP-A-2-233458
[0003]
[Prior art]
Conventionally, an image forming apparatus such as a copier, a printer, a facsimile, or a multifunction peripheral of these types that employs this type of electrophotographic method, binds a sheet on which an image is formed, performs perforation processing on the sheet, Alternatively, a sheet on which an image is formed is discharged in a state where the sheets are offset (shifted) one set at a time, and thus the sheet is sometimes used in combination with a sheet post-processing apparatus including a stapler, a puncher, or an offset catch tray. . The sheet post-processing apparatus uses a sheet stacking apparatus that discharges stapled sheets, perforated sheets, and the like in a stacked state using a stapler, a puncher, or the like.
[0004]
Various technologies relating to the paper stacking device have been already proposed and commercialized. For example, those disclosed in Japanese Patent Application Laid-Open Nos. 2001-206613 and 2-233458 are disclosed. There is.
[0005]
A sheet stacking apparatus according to the above-described Japanese Patent Application Laid-Open No. 2001-206613 is a sheet stacking apparatus including a sheet discharging unit that discharges a sheet, and a sheet stacking unit that receives and stacks a sheet discharged from the discharging unit. The sheet stacking unit includes at least two divided stacking members divided in a width direction orthogonal to the sheet discharging direction, and a lifting drive unit that independently drives at least one of the divided stacking members with respect to the other. It is configured as follows.
[0006]
Further, the sheet post-processing apparatus according to the above-mentioned Japanese Patent Application Laid-Open No. 2-233458 has an auxiliary tray that can be retracted and provided on a sheet mounting side of a tray that stores sheets to be post-processed and discharged. It is configured to have control means for selecting and controlling the hammering operation in accordance with the mode of the seat.
[0007]
[Problems to be solved by the invention]
However, the prior art has the following problems. That is, in the case of the sheet stacking device according to Japanese Patent Application Laid-Open No. 2001-206613, the sheet stacking unit includes at least two divided stacking members divided in a width direction orthogonal to the sheet discharging direction, and a plurality of divided stacking members. Although it is configured to include an elevating drive unit that drives at least one of them independently up and down with respect to the other, depending on the size of the sheet and the number of staples, for example, the staples bound by the stapler may be There is a case where it is located at both ends in the width direction perpendicular to the direction, or a case where it is also located at the center in the width direction perpendicular to the sheet discharge direction, and at least one of the divided stacking members is There is a problem that the swelling of the stapler needle cannot be absorbed even when the stapler is driven up and down.
[0008]
In the case of the sheet post-processing apparatus according to the above-mentioned Japanese Patent Application Laid-Open No. 2-233458, an auxiliary tray which can be retracted is provided on a sheet mounting side of a tray for storing sheets to be post-processed and discharged, and the auxiliary The tray is configured to select and control the retracting operation in accordance with the sheet form.However, when the auxiliary tray provided on the sheet loading side of the tray is freely retractable, the tray moves to the rear end of the tray. A problem arises in that the guide member and the tray that are erected move in a direction away from the tray to form a gap, and the rear end of the sheet enters the gap, thereby bending the rear end of the sheet or making it difficult to take out the sheet. Had a point.
[0009]
Therefore, the present invention has been made to solve the above-described problems of the related art, and an object of the present invention is to provide a case where the sheets are bound with a staple when the sheets are stacked. In addition, the present invention provides a paper stacking apparatus capable of preventing the paper stacking state from becoming unstable due to the bulging of the needle and avoiding an obstacle caused by a gap at the rear end of the tray in the paper transport direction. Is to do.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 includes a discharge tray for discharging post-processed sheets in a stacked state, and a discharge unit for discharging sheets on the discharge tray. In the sheet stacking device, at the rear end of the discharge tray in the sheet discharge direction, a split tray divided from the discharge tray main body is provided so as to be rotatable or vertically movable, and a fixed tray is disposed below the split tray, The rear end of the split tray and the fixed tray and the end guide provided at the rear end of the discharge tray are provided with a concave portion and a convex portion which are fitted to each other to prevent the sheet from falling off. Is a paper stacking device.
[0011]
According to a second aspect of the present invention, there is provided a sheet stacking apparatus including: a discharge tray configured to discharge the post-processed sheets in a stacked state; and a discharge unit configured to discharge the sheets onto the discharge tray. At the rear end of the discharge tray in the sheet discharge direction, a divided tray divided from the discharge tray main body is provided so as to be rotatable or vertically movable, and is disposed at the rear end of the divided tray and at the rear end of the discharge tray. The sheet stacking device is characterized in that at least one of a concave portion and a convex portion which are fitted to the end guide member to prevent the sheet from falling off are made to be able to expand and contract.
[0012]
Further, the invention described in claim 3 is characterized in that the detection of the height of the discharge tray is performed by detecting a portion where the displacement amount of the divided tray is small or a fixed discharge tray main body. 3. The paper loading device according to 1 or 2.
[0013]
According to a fourth aspect of the present invention, the height detecting means for detecting the height of the discharge tray is provided at two places for a binding process and a non-binding process as post-processing for a sheet. 3. The sheet stacking apparatus according to claim 1, wherein height detection is performed at a portion of the tray.
[0014]
Further, according to the invention described in claim 5, in the initial height detection of the discharge tray, after the divided tray is displaced in accordance with the type of post-processing for the sheet, the height is detected in the portion of the divided tray. 3. The sheet stacking device according to claim 1, wherein
[0015]
According to a sixth aspect of the present invention, in the height detecting means for detecting the height of the discharge tray, the detecting means for binding processing is located below the detecting means for no binding processing. The sheet loading device according to claim 1 or 2, wherein
[0016]
Further, according to the invention described in claim 7, the height detection of the discharge tray is performed at two positions, that is, the position of the divided tray and the position of the fixed discharge tray main body, and the position of the fixed discharge tray main body. 3. The sheet stacking device according to claim 1, wherein after detecting the height of the discharge tray, the height is detected at the position of the divided tray, and the divided tray is displaced.
[0017]
Further, in the invention according to claim 8, the split tray is not displaced when the sheet is conveyed with a short edge as a leading edge. It is a loading device.
[0018]
The invention according to claim 9 is the sheet stacking apparatus according to claim 1 or 2, wherein the split tray is not displaced when the post-processing for the sheet includes Z-folding.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
[0020]
Embodiment 1
FIG. 2 shows a sheet post-processing apparatus to which the sheet stacking apparatus according to the first embodiment of the present invention is applied.
[0021]
As shown in FIG. 2, the sheet post-processing apparatus 1 performs a punching process, a binding process, a saddle stitching process, and the like on a sheet on which an image is formed by an image forming apparatus such as a copying machine or a printer (not shown). It is configured to perform post-processing.
[0022]
The sheet post-processing apparatus 1 also includes an interposer 2 that appropriately supplies desired sheets such as a cover sheet and a sheet on which a color image has been formed at predetermined timing to the sheet on which an image is formed by the image forming apparatus. And a folding device 4 for performing a desired folding process such as Z-folding or C-folding on the sheet passing through the interface module 3.
[0023]
In the sheet post-processing apparatus 1, a sheet on which an image is formed by an image forming apparatus (not shown) is subjected to a punching process by a punch unit or a binding process by a stapler to create a sheet bundle or a booklet. In addition, a stack tray (discharge tray) to be offset can discharge a plurality of sheets by offsetting (shifting) each set.
[0024]
As shown in FIG. 2, the interface module 3 is provided with an inlet 5 on the left side thereof, from which a sheet 90 on which an image is formed by an image forming apparatus (not shown) is introduced. It has become so. A carry-in roll 6 for carrying the paper 90 is provided inside the inlet 5. Further, on the downstream side of the carry-in roll 6, there is provided a discharge port 8 which is opened horizontally and horizontally via a paper transport path 7 extending obliquely upward. A curl removing roll 9 for removing curls is provided.
[0025]
Further, on the upper part of the interface module 3, an interposer 2 for appropriately supplying desired paper such as a cover or a color image formed on a paper 90 on which an image is formed by the image forming apparatus is mounted. Have been. The interposer 2 includes a paper feed tray 10 on which paper is loaded, and a nudger roll 11, a feed roll 12, a retard roll which feeds the paper loaded on the paper feed tray 10 one by one. A roll 13 and an exit roll 14 for discharging the fed paper to the interface module 3 are provided. Further, inside the interface module 3, a paper transport path 16 having a transport roll 15 for transporting the paper introduced from the interposer 2 to the discharge port 8 is provided.
[0026]
On the other hand, as shown in FIG. 2, the folding device 4 has an inlet 17 for introducing the paper 90 discharged from the interface module 3 on its left side, and has a horizontal direction on its right side. Is provided with a discharge port 19 for discharging the paper 90 via the paper conveyance path 18 arranged in the printer. An introduction roll 20 is provided inside the introduction port 17, and a conveyance roll 21 is provided downstream of the introduction roll 20, and a folding paper conveyance path 22 branched downward is provided. It is provided vertically downward. The paper 90 introduced into the folding paper transport path 22 is folded in two by the folding roll 24 in a state where the leading end of the paper 90 is abutted against the abutting portion 23. The paper is conveyed to the provided three-fold paper conveyance path 26. Then, the sheet 90 conveyed to the three-fold sheet conveying path 26 is subjected to a process of being folded into three by the folding roll 28 in a state where the leading end of the sheet 90 is abutted against the abutting portion 27. Thereafter, the sheet 90 that has been folded in three is conveyed to the discharge port 19 via the discharge sheet conveyance path 30 provided with the conveyance rolls 29. In the folding apparatus 4, as shown in FIG. 3, the sheet 90 can be C-folded or Z-folded.
[0027]
FIG. 2 also shows a sheet post-processing apparatus to which the sheet stacking apparatus according to the first embodiment of the present invention is applied.
[0028]
The paper post-processing apparatus 1 is provided on its left side with an inlet 31 for introducing the paper 90 that has passed through the folding processing apparatus 4, and inside the inlet 31, the paper 90 is inclined obliquely upward. An introduction roll 33 for transporting the paper along the paper transport path 32 is provided. Further, on the downstream side of the introduction roll 33, the sheet is conveyed by the introduction roll 33, and is also fed back by the reverse rotation roll 34 located further downstream, and the rear end portion is abutted against an abutting portion (not shown). A punch unit 35 is provided as a punching means for performing a punching process on a predetermined position of the sheet 90 whose skew has been corrected. Further, on the downstream side of the punch unit 35, the paper transport path is branched into two, and among the paper transport paths, the paper transport path 36 that is branched upward is a sheet on which a punching process is performed as necessary. This is for discharging the sheet 90 on which the image is formed, or the sheet 90 on which the image is formed, as it is, performing a binding process, or performing offset discharge. On the other hand, among the above-described paper transport paths, the paper transport path 38 that is provided with the transport rolls 37 and that branches downward is subjected to a saddle stitching folding process in which the paper 90 is bound at the center and then folded at the binding portion. It is for doing.
[0029]
The paper transport path 36 branched upward is further branched into two, and the paper transport path 39 branched upward in the vertical direction is provided with a sheet 90 that has been subjected to perforation processing as necessary and an image is formed. This is for discharging the paper 90 as it is or for discharging unnecessary paper 90 onto the fixed tray 40. A transport roll 41 and a top discharge roll 42 are provided in the paper transport path 39, and a sheet 90 on which a perforation process has been performed, a sheet 90 on which an image is formed, and the like, as necessary, are fixed to a fixed tray 40. It is configured to be discharged.
[0030]
Further, among the paper transport paths branched upward, the paper transport path 43 further branched in a substantially horizontal direction performs a binding process along one edge of the paper 90 or a binding process at a corner, or a plurality of sheets. The sheet 90 is discharged in a state where it is offset for each set. A reverse rotation roll 44 for a buffer and a compile discharge roll 45 are disposed in the paper transport path 43, and the compile discharge roll 45 discharges the paper 90 onto the compile tray 46 in order. . Further, a predetermined number of sheets 90 aligned on the compile tray 46 are subjected to a binding process by a stapler 47 as required, and then are stacked by a stack tray as a discharge tray which is offset by a discharge roller 48 as a discharge unit. It is discharged on 49. As shown in FIG. 4, the stapler 47 can perform various binding processes on the paper 90.
[0031]
At the base end of the compile tray 46, a guide member 50 for abutting the base end of the paper 90 is provided so as to be retractable, and a paddle 51 for aligning the paper 90 is provided rotatably. ing. Further, a tamper 52 for arranging the sheets 90 in the width direction is provided at an intermediate portion of the compile tray 46 so as to be movable in a direction perpendicular to the drawing. An auxiliary paddle 53 for arranging the sheets 90 and a retractable shelf member 54 for guiding the sheet bundle are provided at the leading end of the compile tray 46. Further, a clamper 55 as a holding member for holding the base end of the sheet 90 discharged onto the tray 49 is rotatably disposed at the base end of the stack tray 49.
[0032]
The discharge roll 48 and the auxiliary paddle 53 serving as the discharge means can be individually moved upward at a predetermined timing.
[0033]
Further, at the upper end of the paper transport path 36, a double transport path 56 branches downward, and a buffer roll 57 is provided in the double transport path 56.
[0034]
A discharge roll 61 for discharging the paper 90 onto the alignment tray 60 is provided below the paper transport path 38 branched from the downstream side of the punch unit 35. At the lower end, an end guide 62 that abuts against the lower end of the paper 90 is provided to be movable in the vertical direction. Further, a stapler 63 for saddle stitching, a tamper driving unit 64 for driving a tamper (not shown) for aligning the paper 90, and a folding knife unit for folding the aligned paper 90 at the center are provided in the middle of the alignment tray 60. 65 are provided. The paper 90 aligned on the alignment tray 60 is folded at the center by a folding knife section 65 and two sets of folding rolls 66, and then discharged onto a book tray 68 by an exit roll 67. It is configured to: Reference numeral 69 denotes a paddle provided above and below the alignment tray 60 for aligning the paper 90.
[0035]
Further, as shown in FIG. 5, the sheet stacking device 70 according to the present embodiment includes a stack tray 49 as a discharge tray that is vertically movably arranged. A clamper 55 as a holding member is turned at a position corresponding to the rear end of the stack tray 49 in the discharge direction and at the rear end of the stack tray 49 in the discharge direction when the stack tray 49 moves to the uppermost end. It is movably arranged. As shown in FIG. 5, the clamper 55 is rotatably attached to the back surface of the end plate 71 of the stack tray 49 which is arranged to be able to move up and down.
[0036]
More specifically, as shown in FIG. 5, the end plate 71 has three recessed grooves 72 linearly formed in a vertical direction at predetermined intervals along the horizontal direction. As shown in FIG. 6, the clampers 55 are attached at positions corresponding to the upper ends of the concave grooves 72 along the axial direction of the rotating shaft 73.
[0037]
As shown in FIG. 7, these clampers 55 include a rear end portion 74 extending radially outward with respect to the rotation shaft 73, and a clockwise direction from the rear end portion 74 and a radially outer portion. An intermediate portion 75 extends in a curved state, and a tip portion 76 extends radially outward from the intermediate portion 75 in a direction substantially tangential to the rotation shaft 73. A non-slip member 77 made of rubber or the like is fixed to the distal end portion 76 of the clamper 55. Further, as shown in FIG. 7, the clamper 55 is attached rotatably over a predetermined angle with respect to the rotation shaft 73, and the clamper 55 is mounted on one side of the clamper 55 in a clockwise direction. An attachment member 78 for attaching a spring 80 as an urging member for urging is attached to the rotating shaft 73 in a fixed state. One end of each of the clampers 55 is locked by a projection 79 projecting from the intermediate portion 75 on the opposite side to the bending direction, and the other end is locked by a mounting member 78 as a biasing member. The coil spring 80 is configured to be individually urged clockwise in FIG.
[0038]
As shown in FIG. 8, a driving gear 81 is attached to one end of the rotating shaft 73 to which the clamper 55 is attached, and a sector gear 82 is attached to the driving gear 81. Are engaged. The tip of an operating rod 84 of a solenoid 83 is connected to the fan-shaped gear 82, and the rotating shaft 73 is rotatable by turning on / off the solenoid 83. A member for driving the clamper 55 such as the solenoid 83 is mounted on the back surface of the end plate 71 as shown in FIG. Further, as shown in FIG. 8, a metal arm 85 is attached to the rotating shaft 73, and a compression spring 86 is attached to a distal end of the arm 85. , Are biased in a counterclockwise direction. Then, as shown in FIG. 9, the clamper 55 is rotatable between a separated position separated from the sheet 90 and a pressing position for pressing the sheet 90 by turning on / off the solenoid 83. The clamper 55 is urged to press the upper surface of the paper 90 so as to be rotatable by a predetermined angle at a holding position for pressing the paper 90.
[0039]
Further, in this embodiment, as shown in FIGS. 6 and 10, when the clamper 55 is offset at the retracted position separated from the sheet 90, it is configured not to contact the lower discharge roll 48. Further, as shown in FIG. 10, the clamper 55 is configured to abut on the rotating shaft 48a of the lower discharge roll 48 and stop at the retracted position separated from the paper 90. Further, the clamper 55 is disposed so as not to protrude from the running surface of the sheet 90 in an operation trajectory moving from the holding position to the retracted position. As a result, even when the clamper 55 is at a position retracted from the upper surface of the sheet 90, the clamper 55 does not hinder the ejection of the sheet 90.
[0040]
Further, in the sheet stacking device 70 according to the present embodiment, as shown in FIG. 11, the stack tray 49 is disposed so as to be movable in the vertical direction, and the stack tray 49 discharges the sheet 90. It is arranged so as to be offset along a direction orthogonal to the direction.
[0041]
As shown in FIG. 11, the paper stacking device 70 includes a pair of side frames 91 and 92 fixed and arranged in parallel with each other on the in side and the out side. As shown in FIG. 5, the inner and outer side frames 91 and 92 are connected to be parallel to each other by a plurality (three in the illustrated example) of connecting angle members 93 to 95. I have. An end frame 71 is slidably attached to the upper two connection angles 93 and 94 along the horizontal direction.
[0042]
Further, as shown in FIG. 11, a movable frame 96 having a substantially U-shaped cross section located at the rear end of the stack tray 49 in the discharge direction is provided between the inner and outer side frames 91 and 92. The movable frame 96 is movably mounted in the vertical direction along guide grooves 97 and 98 provided in the side frames 91 and 92 in a state of being inclined.
[0043]
As shown in FIG. 11, a moving mechanism 99 for moving the moving frame 96 in the vertical direction is attached to one end of the moving frame 96 in the longitudinal direction. The moving mechanism 99 includes an elevator motor 100 and a gear train that reduces the rotational driving force of the elevator motor 100 and transmits the reduced rotational driving force to the pinion gear 101. As shown in FIGS. 5 and 11, the pinion gear 101 is engaged with long rack gears 102 and 103 provided along the guide grooves 97 and 98, and the one pinion gear 101 is connected to the elevator. When the motor 100 is driven to rotate in a predetermined direction, the moving frame 96 can be moved in the vertical direction.
[0044]
As shown in FIG. 1, a stack tray 49 is slidably attached to the moving frame 96 via a guide rail 104 for linear sliding along a direction perpendicular to the direction in which the paper 90 is discharged. . The lower side of the stack tray 49 is held by a tray holder 112 attached to the moving frame 96. The stack tray 49 is connected to the end frame 71, and the stack tray 49 is slidable integrally with the end frame 71 in a direction orthogonal to the paper 90 discharge direction.
[0045]
Further, as described above, the end frame 71 is also slidably attached in a direction orthogonal to the paper 90 discharge direction. On the back side of the end frame 71, as shown in FIGS. 5 and 12, an offset motor 105 and a gear train 106 for reducing the rotational driving force of the offset motor 105 and transmitting it to the eccentric cam 107. Are arranged. By driving the offset motor 105 to rotate in a predetermined direction, the eccentric cam 107 is rotated by a predetermined amount, and the end guide 71 provided with the concave portion 108 in contact with the eccentric cam 107 is moved to the paper The stack tray 49 connected to the end guide 71 is offset by a predetermined amount in the direction orthogonal to the discharge direction of the paper 90 by moving the stack tray 49 connected to the end guide 71 in the direction perpendicular to the discharge direction. .
[0046]
When the end guide 71 moves in the direction perpendicular to the direction in which the sheet 90 is discharged as described above, the three clampers 55 attached to the end guide 71 also simultaneously move in the direction perpendicular to the direction in which the sheet 90 is discharged. It is configured to move along.
[0047]
By the way, in this embodiment, in a sheet stacking apparatus provided with a discharge tray for discharging post-processed sheets in a stacked state and a discharge unit for discharging sheets on the discharge tray, At the rear end of the sheet discharge direction, a split tray divided from the discharge tray main body is provided so as to be rotatable or vertically movable. A fixed tray is disposed below the split tray, and the rear ends of the split tray and the fixed tray are provided. The unit and the end guide provided at the rear end of the discharge tray are configured to have a concave portion and a convex portion which are fitted to each other to prevent the sheet from falling off.
[0048]
Further, in this embodiment, the height of the discharge tray is detected by detecting a portion where the displacement amount of the divided tray is small or a fixed discharge tray main body.
[0049]
Further, in this embodiment, height detecting means for detecting the height of the discharge tray is provided at two locations for binding processing and no binding processing as post-processing for the paper, and at the divided tray portion, It is configured to perform height detection.
[0050]
That is, as shown in FIGS. 1 and 13, the stack tray 49 serving as the discharge tray is rotated at the rear end of the stack tray 49 in the sheet discharge direction by the divided tray 49 b divided from the stack tray body 49 a. It is provided as possible. The split tray 49b may not be rotatable but may be provided so as to be able to move up and down with respect to the stack tray main body 49a. As shown in FIG. 13, the split tray 49b transmits the rotational driving force of the stacker flap motor 130 to the rotary shaft 132 in a decelerated state via a gear tray 131 including a plurality of gears. The fixed sector-shaped gear 133 is rotatable in the direction of the arrow. The sector gear 133 is meshed with a gear (not shown) rotatably provided on the division tray 49b, and by rotating the sector gear 133, the division tray 49b can be rotated in the arrow direction. It has become. The stack tray main body 49a is provided with a no-paper sensor 134 for detecting the absence of paper and a safety switch 135.
[0051]
As shown in FIGS. 1 and 11, the end guide 71 is provided with a concave groove 72 as a concave along the vertical direction at a position corresponding to the three clampers 55. Further, at the rear end of the split tray 49b in the discharging direction, as shown in FIG. As a result, the projection 111 of the split tray 49b is configured to prevent a gap from being formed between the rear end of the split tray 49b and the end guide 71, and to prevent the sheet 90 from falling off. In FIG. 14, reference numeral 112 denotes a tray support disposed below the stack tray 49.
[0052]
Further, below the split tray 49b, a fixed tray 136 attached to a tray support 112 provided below the stack tray 49 is provided as shown in FIGS. At the rear end of the fixed tray 136, a convex portion 137 is provided so as to correspond to the concave groove 110 of the end guide 71. The convex portion 137 is fitted into the concave groove 110 of the end guide 71, The gap between the rear end of the fixed guide 136 and the end guide 71 is prevented, and the paper 90 is prevented from falling off.
[0053]
Further, as shown in FIG. 11, the upper and lower side frames 91 and 92 have a plurality of sheet height detections for detecting sheets or sheet bundles discharged onto the stack tray 49, as shown in FIG. Sensors 121 to 123 and a detection sensor 124 for detecting the position of the upper surface of the stack tray 49 are provided. The three sheet height detection sensors 121 to 123 are provided, and a first sheet height detection sensor 121, a second sheet height detection sensor 122, and a third sheet height detection sensor 123 are provided. Are configured to detect different sheet heights. The sheet height detection sensors 121 to 123 and the detection sensor 124 for detecting the upper surface position of the stack tray 49 are composed of a light emitting unit 141 and a light receiving unit 142 as shown in FIG. The height is detectable by detecting whether or not the emitted light is blocked by the sheet 90 or the stack tray 49 by the light receiving unit 142.
[0054]
As shown in FIG. 1, the first sheet height detection sensor 121 and the third sheet height detection sensor 123 include a stack main body 49a to which the stack tray 49 is fixed, and a non-rotating divided tray 49b. Are configured to detect the respective heights. Further, as shown in FIG. 17, the second sheet height detection sensor 122 is disposed so as to detect the surface of the divided tray 49b in a state where the divided tray 49b is rotated downward.
[0055]
As shown in FIG. 11, a mixed stack sensor 125 and a half stack sensor 126 are provided at the upper ends along the guide grooves 97 and 98 on the inner and outer side frames 91 and 92, respectively. At its lower end, a full stack sensor 127 and a lower limit detection sensor 128 are provided.
[0056]
In the above configuration, in the paper stacking apparatus according to the present embodiment, when the paper is stacked as described below, even if the paper is bound with a staple, The stacking state of the trays does not become unstable, and it is possible to avoid the obstacle caused by the formation of a gap at the rear end of the tray in the sheet transport direction.
[0057]
That is, as shown in FIG. 2, the sheet post-processing apparatus to which the sheet stacking apparatus 70 according to this embodiment is applied includes a sheet 90 on which an image is formed by the image forming apparatus and the interface module 3 and the folding processing apparatus. 4 through an inlet 31 provided on the left side surface. The sheet 90 introduced into the sheet post-processing apparatus 1 is subjected to a predetermined punching process by a punch unit 35 as needed, or is stapled by a stapler 47 at one edge or corner as shown in FIG. The sheets are sequentially discharged onto a stack tray 49 as a discharge tray after the binding processing is performed or as it is.
[0058]
At this time, as shown in FIG. 4, for example, as shown in FIG. 4, if one end along the width direction of the paper 90 is stapled by the stapler 47 among the rear ends in the paper discharge direction, as shown in FIG. As shown in the figure, the portion bound by the staples 150 becomes thicker, and even if the stack tray 49 is lowered by a predetermined amount, the subsequent sheet bundle is increased by the thickness of the portion bound by the staples 150. 151 would be disturbed.
[0059]
Therefore, in this embodiment, first, the height of the stack tray 49 is detected by the first sheet height detection sensor 121 and the third sheet height detection sensor 123, and the height of the sheet 90 or the sheet bundle 151 is detected. When the stapling process is not performed by the stapler 47, as shown in FIG. 19, the divided trays 49b are sequentially moved downward without rotating, while maintaining the parallel state.
[0060]
On the other hand, when the binding process is performed on the sheet 90 by the stapler 49, as shown in FIG. 20, the height of the stack tray 49 is changed to the first sheet without rotating the divided tray 49b. The split tray 49b is rotated only when the height of the rear end portion on the stack tray 49 is detected to be higher than a predetermined amount by the height detection sensor 121 and the third sheet height detection sensor 123. You may do so.
[0061]
When the stapling process is performed on the sheet 90, as shown in FIG. 17, the height of the stack tray 49 and the divided tray 49b is set to the first height while the divided tray 49b is rotated in advance. May be detected by the sheet height detection sensor 121 and the third sheet height detection sensor 123, and the stack tray 49 may be moved downward as it is.
[0062]
In this embodiment, as shown in FIGS. 1 and 14, the projection 111 provided at the rear end of the divided tray 49 b in the sheet conveyance direction is fitted into the concave groove 72 provided at the end guide 71. Since the projections 137 provided at the rear end of the fixed tray 136 in the sheet conveyance direction are fitted into the concave grooves 72 provided at the end guide 71, Even if the sheet 49b is rotated downward, a gap is formed between the rear end of the divided tray 49b and the end guide 71, so that the sheets 90 and the sheet bundle 151 can be prevented from dropping downward. .
[0063]
In this embodiment, the divided tray 49b is configured not to be displaced when the sheet 90 is conveyed with the short edge being the leading edge.
[0064]
Further, in this embodiment, the split tray 49b is configured not to be displaced when the post-processing for the sheet 90 includes the Z-fold as shown in FIG.
[0065]
The reason is that when the sheet 90 is conveyed with the short edge as the leading edge, or when the post-processing for the sheet 90 includes Z-folding as shown in FIG. This is because the leading end of the sheet 90 discharged on the stack tray 49 in the discharge direction becomes higher than usual, and the posture of the sheet 90 tends to be unstable.
[0066]
As described above, in the above-described embodiment, when the sheets 90 are stacked on the stack tray 49, even if the sheets 90 are bound by the staples 150, the stacked state of the sheets 90 is increased by the swelling of the staples 150. It does not become unstable, and it is possible to avoid an obstacle caused by a gap at the rear end of the stack tray 49 in the sheet conveying direction.
[0067]
Embodiment 2
FIG. 15 shows another embodiment of the present invention, in which the same parts as those of the above embodiment are denoted by the same reference numerals. At the rear end, a split tray divided from the discharge tray main body is provided rotatably or vertically movable, and the rear end of the split tray and an end guide member disposed at the rear end of the discharge tray include: At least one of the concave portion and the convex portion, which are relatively fitted to each other to prevent the sheet from falling off, are configured to be stretchable.
[0068]
That is, in the second embodiment, as shown in FIG. 21, the projection 111 provided at the rear end of the divided tray 49b in the sheet conveying direction is provided on the plate-like member 160 separate from the divided tray 49b. The plate-like member 160 is provided so as to be able to protrude and retract with respect to the divided tray 49b, and is urged in a projecting direction by urging means (not shown).
[0069]
Therefore, even when the divided tray 49b is rotated downward, as shown in FIG. 21, the plate-like member 160 provided with the convex 111 protrudes, and the plate-like member 160 However, by fitting into the concave groove 72 of the end guide 71, a gap is formed between the rear end of the divided tray 49b and the end guide 71, and the sheet 90 or the sheet bundle 150 is prevented from dropping downward. It is configured to be able to.
[0070]
Other configurations and operations are the same as those in the first embodiment, and thus description thereof will be omitted.
[0071]
【The invention's effect】
As described above, according to the present invention, when sheets are stacked, even if the sheets are bound with staples, the swelling of the staples does not make the stacked state of the sheets unstable. In addition, it is possible to provide a sheet stacking apparatus capable of avoiding an obstacle caused by a gap at the rear end of the tray in the sheet conveying direction.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a sheet stacking device according to a first embodiment of the present invention.
FIG. 2 is an overall configuration diagram illustrating a sheet post-processing device to which the sheet stacking device according to the first embodiment of the present invention is applied;
FIG. 3 is an explanatory diagram showing a folding process in the folding device.
FIG. 4 is an explanatory diagram showing types of binding processing in the stapler;
FIG. 5 is a rear perspective view showing the sheet stacking device according to the first embodiment of the present invention.
FIG. 6 is a configuration diagram showing an end guide and a clamper.
FIG. 7 is a configuration diagram showing a clamper.
FIG. 8 is a configuration diagram showing a driving mechanism of the clamper.
FIG. 9 is a configuration diagram showing a driving state of a clamper.
FIG. 10 is a configuration diagram illustrating a sheet stacking apparatus according to the first embodiment of the present invention.
FIG. 11 is a front perspective view showing the sheet stacking device according to the first embodiment of the present invention.
FIG. 12 is a configuration diagram showing an offset mechanism of a stack tray.
FIG. 13 is a perspective configuration diagram illustrating a main part of the sheet stacking apparatus according to the first embodiment of the present invention.
FIG. 14 is a perspective configuration diagram showing a stack tray.
FIG. 15 is a configuration diagram showing an operation of the sheet stacking device according to the first embodiment of the present invention.
FIG. 16 is a configuration diagram showing a sheet detection sensor.
FIG. 17 is a configuration diagram illustrating an operation of the sheet stacking device according to the first embodiment of the present invention.
FIG. 18 is an explanatory diagram illustrating an operation of the sheet stacking device according to the first embodiment of the present invention.
FIG. 19 is a configuration diagram showing an operation of the sheet stacking device according to the first embodiment of the present invention.
FIG. 20 is a configuration diagram illustrating a sheet stacking device according to the first embodiment of the present invention.
FIG. 21 is a configuration diagram showing a sheet stacking apparatus according to Embodiment 2 of the present invention.
[Explanation of symbols]
1: paper post-processing device, 49: stack tray, 49a: stack tray main body, 49b: split tray, 48: discharge roll, 55: clamper, 71: end guide, 72: concave groove, 111: convex portion.

Claims (9)

In a paper stacking apparatus including a discharge tray that discharges the post-processed paper in a stacked state, and a discharge unit that discharges the paper onto the discharge tray,
At the rear end of the discharge tray in the sheet discharge direction, a divided tray divided from the discharge tray main body is provided so as to be rotatable or vertically movable. A fixed tray is provided below the divided tray, and the divided tray and the fixed A sheet provided with a concave portion and a convex portion which are fitted to each other at a rear end portion of the tray and an end guide provided at a rear end portion of the discharge tray to prevent the sheet from falling off; Loading device. In a paper stacking apparatus including a discharge tray that discharges the post-processed paper in a stacked state, and a discharge unit that discharges the paper onto the discharge tray,
At the rear end of the discharge tray in the sheet discharge direction, a divided tray divided from the discharge tray main body is provided so as to be rotatable or vertically movable, and is disposed at the rear end of the divided tray and at the rear end of the discharge tray. A sheet stacking device characterized in that at least one of a concave portion and a convex portion which are fitted to an end guide member relatively to prevent the sheet from falling off are extendable. 3. The sheet stacking apparatus according to claim 1, wherein the detection of the height of the discharge tray is performed by detecting a portion of the divided tray where the displacement amount is small or a fixed discharge tray body. Height detecting means for detecting the height of the discharge tray is provided at two locations for binding processing and no binding processing as post-processing for paper, and performs height detection at a divided tray portion. The sheet stacking device according to claim 1 or 2, wherein 3. The initial height detection of the discharge tray is performed by displacing a divided tray according to the type of post-processing for a sheet and then detecting the height of the divided tray. Paper loading device according to the above. 3. The sheet stacking device according to claim 1, wherein in the height detection unit that detects the height of the discharge tray, a detection unit for binding processing is located below a detection unit for no binding processing. 4. apparatus. The detection of the height of the discharge tray is performed at two positions, that is, the position of the split tray and the position of the fixed discharge tray main body. After the height of the discharge tray is detected at the position of the fixed discharge tray main body, the division is performed. 3. The sheet stacking device according to claim 1, wherein the height of the divided tray is detected by detecting the height at the position of the tray. The sheet stacking apparatus according to claim 1, wherein the split tray is not displaced when the sheet is conveyed with a short edge as a leading edge. The sheet stacking device according to claim 1, wherein the split tray is not displaced when the post-processing for the sheet includes Z-folding.

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