JP4343485B2 - Sheet post-processing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet post-processing apparatus and an image forming apparatus having the sheet post-processing apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image forming apparatus such as a printer includes a sheet post-processing apparatus that performs post-processing such as stapling (stitching) on a plurality of sheets on which images have been formed (printed), aligns the ends, and discharges the sheets. There is something that is. As such a sheet post-processing apparatus, sheets printed on the image forming apparatus main body side can be sequentially supplied from the discharge port, aligned at each end, and discharged after being subjected to post-processing. Also known are sheets that can be stacked without post-processing.
[0003]
[Problems to be solved by the invention]
However, in such a conventional image forming apparatus, the size of the apparatus is increased by providing an intermediate stacking unit for aligning sheets for performing a stapling operation separately from a sheet path for discharging a sheet on which the stapling operation is not performed. There was a case.
[0004]
When the intermediate stacking unit for aligning the sheets before the stapling operation is formed on the discharge roller pair 630a and 630b disposed on the downstream side, as shown in FIG. When the sheet is conveyed when the pair of discharge rollers is stopped because the upper surface of the lower roller 630b of the pair of discharge rollers is above the sheet path (h in the figure), the front end surface of the sheet is discharged. The roller may be caught and misalignment may occur. As a result, the sheets may be stapled with a large amount of sheet misalignment. Further, there is a problem that the sheet is jammed in the apparatus when the sheet is caught.
[0005]
An object of the present invention is to improve sheet alignment when post-processing a sheet.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a typical configuration of the present invention is a sheet post-processing apparatus that has post-processing means and performs post-processing on a conveyed sheet, and is an upper roller and a lower roller that can be separated from each other A pair of discharge rollers for discharging the sheet, an intermediate stacking portion for temporarily stacking the sheets, and being orthogonal to the sheet conveying direction. Alignment means that can move in the width direction of the sheet to be aligned and abuts and aligns with the width direction end of the sheet on the intermediate stacking section, and the sheet moves by the alignment means among the lower rollers In this case, the roller in contact with the end portion in the width direction of the sheet has a shape in which the rotation radius of the roller increases toward the downstream side in the moving direction of the sheet within a range in contact with the moving sheet. Perimeter Provided with a kick-out portion that kicks out the rear end of the sheet on the downstream side in the roller rotation direction, and the kick-out portion has a taper shape or a circle that decreases from the apex having the maximum rotation radius toward the upstream side in the roller rotation direction. It is characterized by being configured in an arc shape.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings. In the following reference examples and embodiments, an example of a sheet post-processing apparatus mounted on a printer represented by a laser beam printer will be described.
[0008]
(First Reference Example )
First, a first reference example will be described with reference to FIGS. FIG. 1 is a schematic sectional view showing the overall configuration of a sheet post-processing apparatus and an image forming apparatus (printer).
[0009]
In FIG. 1, reference numeral 100 denotes a printer body, which is connected to a computer alone or connected to a network such as a LAN, and a predetermined image forming process based on image information, a print signal, etc. sent from the computer or the network. The apparatus forms (prints) an image on a sheet and discharges the sheet.
[0010]
On the other hand, the sheet post-processing apparatus 300 as a post-processing unit is a face-down state in which the sheet discharged from the printer main body 100 is discharged to the outside through the conveying unit in the sheet post-processing apparatus with the image surface facing down. The sheet is placed on the intermediate stacking unit 300B, aligned by an aligning unit, bundled for each predetermined job, stapled at one or more positions of the sheet, and discharged and stacked on the sheet stacking unit 325 of the sheet post-processing apparatus. Or a device for discharging and stacking on the sheet stacking unit 325 of the sheet post-processing apparatus simply by face-down.
[0011]
Here, the sheet post-processing apparatus 300 and the printer main body 100 are electrically connected by a cable connector (not shown). The sheet post-processing apparatus 300 includes a casing part 300A for storing each part, and is configured to be detachable from an apparatus main body 100A of the printer main body 100 described later.
[0012]
Next, the configuration of each unit of the printer main body 100 will be described along the conveyance path of the sheet S to be conveyed. In the printer main body 100, a plurality of sheets S are stacked in the feeding cassette 200, and the uppermost sheet among them is sequentially separated and fed one by one by various rollers. The sheet S fed from the feeding cassette 200 by a predetermined print signal supplied from a computer or a network is an image that forms a toner image in the printer main body 100 by a so-called laser beam type image forming process. The toner image is transferred to the upper surface of the sheet by the forming unit 101, and then the toner image is permanently fixed by applying heat and pressure to the fixing device 120 on the downstream side.
[0013]
As shown in FIG. 1, the sheet S on which the image has been fixed is folded back in a substantially U-shaped sheet conveyance path up to the discharge roller 130, so that the image surface is reversed and the image surface is on the lower side. In this state, the paper is discharged face down from the printer main body 100 by the discharge roller 130. Here, the sheet S is discharged face down (FD) provided on the upper portion of the printer body 100 by determining the position of the flapper 150 of the printer body 100 based on a control signal from a control unit (not shown). Whether the sheet is discharged to the unit 125 or the sheet stacking unit 325 of the sheet post-processing apparatus 300 is selected.
[0014]
Next, the configuration of the sheet post-processing apparatus 300 and the movement of each part when the sheet S conveyed by the discharge roller 130 goes to the sheet post-processing apparatus 300 will be described with reference to FIGS. FIG. 2 is an enlarged view of the sheet post-processing apparatus 300, and FIG. 3 is an operation explanatory view of the slide guide at each position of the sheet S.
[0015]
As shown in FIG. 2, the sheet post-processing apparatus 300 includes a discharge upper roller 330a, a discharge lower roller 330b, a jogger motor M as a driving source, a paddle 322, and a reference wall 323 for abutting the sheet rear end.
[0016]
The discharge roller pair 330 including the discharge upper roller 330a and the discharge lower roller 330b is disposed on the upstream side in the sheet conveying direction of the flapper 150 described above, and is rotationally driven by a drive motor (not shown). Further, the discharge upper roller 330 a is pivotally supported by an arm 331 that can rotate around a paddle shaft 350.
[0017]
The jogger motor M is a motor for driving slide guides (301, 302) described later, and a stepping motor is used in this embodiment. The paddles 322 are made of a flexible material such as rubber, and a plurality of paddles 322 are fixed to the paddle shaft 350 in a direction perpendicular to the sheet conveying direction. When the paddle shaft is driven and rotated clockwise, the sheet S is moved in the direction opposite to the sheet conveyance direction, and the width direction side surface of the sheet S is brought into contact with the reference wall 323 for alignment.
[0018]
As shown in FIG. 3, in the sheet post-processing apparatus 300 according to the present embodiment, a slide guide R301 and a slide guide L302, which will be described in detail later, are provided as alignment means for performing alignment by moving in the sheet width direction. ing.
[0019]
In the sheet post-processing apparatus 300, when stapling is performed based on a command output in advance from a computer or the like, a sheet S to be stapled is discharged by a solenoid (not shown) before being discharged by the discharge roller 130. The flapper 150 is rotated counterclockwise in FIG. 2 through the link, comes into contact with the stopper at the position of FIG. 2A and stops, and the sheet path is switched to the sheet post-processing apparatus 300. In this way, the sheet S is carried in through the inlet sensor 390 of the sheet post-processing apparatus 300 by the roller pair provided downstream of the fixing device 120 of the printer main body 100.
[0020]
The sheet S carried into the sheet post-processing apparatus 300 rotates the flag of the entrance sensor 390 in the clockwise direction, and the flag causes the photosensor to transmit, thereby detecting the entry of the sheet S. Thereafter, the sheet is conveyed upward by the inlet roller pair 363.
[0021]
With such a configuration, the sheet post-processing apparatus 300 can staple and stack the sheets on the sheet stacking unit 325 of the sheet post-processing apparatus, and can simply discharge and stack the sheets on the sheet stacking unit 325 of the sheet post-processing apparatus in a face-down manner. Become. Hereinafter, description will be made with different cases.
[0022]
First, an operation of discharging and stacking on the sheet stacking unit 325 of the sheet post-processing apparatus in a face down manner will be described. As shown in FIG. 4, in the sheet post-processing apparatus 300, the bottom surfaces of the right slide guide R301 and the left slide guide L302 with respect to the sheet carry-in direction are in positions where they do not come into contact with the loaded sheet S, that is, the sheet. The sheet S is retracted to a position outside by a predetermined amount from the width direction of S, and the sheet S is directly conveyed to the stacking unit of the sheet post-processing apparatus.
[0023]
The sheet conveyed by the inlet roller pair 363 passes through the staple roller 320 and then passes through the staple H opening as post-processing means, and then is conveyed by the discharge roller pair 330 to the sheet stacking unit 325 of the sheet post-processing apparatus. Loaded.
[0024]
The discharge roller pair 330 (330a, 330b) has a comb-teeth configuration as shown in FIG. 10 in order to reliably discharge a thin sheet, and the sheets are nipped by rollers arranged in a staggered manner (staggered arrangement). And convey the sheet. Further, the right and left ends of the lower discharge roller 330b are provided with a stiffening member having a diameter that increases as the distance from the sheet conveyance center increases. Take.
[0025]
When the stacking capacity of the sheet stacking unit is small, that is, when the height of the discharge roller pair 330 and the lower surface of the stacking unit is small, there is no problem in stacking even if the sheet is not stiff. However, this apparatus needs to be stiffened because it is necessary to increase the number of sheets stacked on the sheet stacking unit. Accordingly, since the sheet stacking unit 325 of the sheet post-processing apparatus increases the stacking capacity, it is possible to reliably stack even if the sheet stacking unit 325 is disposed at a low position.
[0026]
Further, the discharge roller pair 330 is provided with a right kick roller 330R and a left kick roller 330L at both ends of the lower discharge roller 330b so that the rear end of the sheet can be reliably discharged to the sheet stacking portion 325. The cross-sectional shape of these kick-out rollers is configured as shown in FIG.
[0027]
The sheet S is conveyed in the direction of the arrow, and each roller (330R, 330L) rotates clockwise. At this time, since each kick roller 330R, 330L has a kick-out portion 330K, the kick-out portion 330K is configured to reliably abut against the sheet S and kick out. Further, in order to apply stiffness to the thin sheet S, each of the kicking rollers 330R and 330L has a larger diameter toward the end of the sheet. As a result, both ends of the sheet can be lifted up and discharged, and the sheet is discharged almost linearly until the trailing end of the sheet passes the discharge roller pair 330. The right kicking roller 330R and the left kicking roller 330L have a symmetrical shape.
[0028]
Next, an operation of stapling and discharging and stacking on the sheet stacking unit 325 of the sheet post-processing apparatus will be described with reference to FIG. Note that the movement of the paddle 322 and the drawings that are not directly related to the reference example are omitted.
[0029]
At this time, as shown in FIG. 3A, in the sheet post-processing apparatus 300, the reference pin R303 and the reference pin L304 provided on the wall surfaces of the right slide guide R301 and the left slide guide L302 with respect to the sheet carry-in direction. However, the sheet S is retracted to a position outside by a predetermined amount from the width direction of the sheet S so as not to interfere with the sheet S that is carried in. The interval between the side surfaces in the width direction of the bottom surface of the slide guide is at a position smaller than the width of the sheet S (the support surface of the aligning means is inside the width of the sheet) and waits for the sheet S to enter. This position is set as a standby position.
[0030]
The first sheet passes through the entrance roller pair 363 and the staple roller 320 and then passes through the front opening of the staple H, and is then conveyed by the discharge roller pair 330, and is supported by the support surfaces of the slide guide R301 and the slide guide L302. It is conveyed onto the guide surface of the intermediate stacking unit 300B that is configured. The sheet is conveyed with a central reference. The discharge roller pair 330 is configured so that the roller pair is nipped evenly on the left and right sides because the roller portion is arranged in the direction perpendicular to the sheet conveyance direction in accordance with the sheet conveyance center. At this time, all the rollers are in a rotating state.
[0031]
As shown in FIG. 1, the guide surface of the intermediate stacking unit 300B is inclined at a predetermined angle with respect to the horizontal direction, and is inclined at different angles on the upstream side and the downstream side in the sheet loading direction. Specifically, a bent portion 300C that is bent at an inclination angle α is formed between a predetermined section on the upstream side and a predetermined section on the downstream side. By having such a bent portion 300C on the guide surface of the intermediate stacking portion 300B, bending of the central portion of the sheet S that is not guided by the slide guides 301 and 302 is prevented.
[0032]
As shown in FIG. 3A, the first sheet is nipped by the discharge roller pair 330 and conveyed onto the surface formed by the slide guide R301 and the slide guide L302.
[0033]
Immediately thereafter, as shown in FIG. 3B, the arm 331 rotates counterclockwise, so that the discharge upper roller 330a pivotally supported on the arm 331 is retracted upward, and the discharge roller pair 330 is separated. At the same time, the drive connected to the discharge roller pair 330 is released to stop the rotation of the discharge upper roller 330a and the discharge lower roller 330b. At this time, the other rollers remain rotating. When the trailing edge of the sheet S completely passes through the staple roller 320, the sheet returns to the direction opposite to the conveyance direction by its own weight and moves toward the reference wall 323.
[0034]
Next, only the left slide guide L302 is operated, and the alignment operation in the width direction of each sheet stacked on the intermediate stacking unit 300B is started. Specifically, when the slide guide L302 is driven by the motor M and moves in the direction of the slide guide R301, the reference pin L304 provided on the slide guide L302 comes into contact with the side surface of the sheet S, and the sheet S is moved toward the slide guide R301. Push in. Then, the opposite side surface of the sheet S abuts on a reference pin R303 provided on the slide guide R301 and a reference pin 305 provided on the post-processing apparatus main body, whereby alignment in the width direction of each sheet is performed.
[0035]
The surface of the roller portion of the lower discharge roller 330b of the discharge roller pair 330 is configured to protrude upward with respect to the sheet path as shown in FIG. 12 (h in the figure). Therefore, when the slide guide L302 performs the sheet aligning operation, the sheet moves upward in the drawing while the sheet abuts the right kick roller 330R of the discharge roller pair. In the conventional apparatus, the sheet to be aligned with the side wall of the abutting roller may come in contact and get caught, but the kicking roller in this reference example moves in the direction in which the sheet moves when the sheet is aligned. On the other hand, as shown in FIGS. 5 and 6, since the ribs a to d are tapered in the sheet entry direction indicated by the arrow, the sheet S is caught by the right kick roller 330R. It is reliably aligned without
[0036]
The sheet S is set to move to the position of the staple H set at the position where the sheet S is in contact with the reference pin R303 and aligned. After the alignment operation, the slide guide L302 moves in a direction wider than the width of the sheet S so that the next sheet can be conveyed again at the standby position.
[0037]
As shown in FIG. 3C, the second sheet S is conveyed on the basis of the center like the first sheet. Since the first sheet is moved to the slide guide R301 side (the upper side in the figure) by the alignment operation, when the second sheet moves on the discharge roller pair 330, it contacts the left kick roller 330L. It is conveyed while. At this time, the lower discharge roller 330b is not rotating.
[0038]
The kick rollers 330R and 330L of this reference example are subjected to R processing and chamfering in the sheet conveying direction indicated by the arrows as shown in the cross-sectional shape shown in FIG. 7, and the kicking section 330K is provided in the sheet discharging direction. Therefore, the sheet S is not caught on the lower discharge roller 330b and is smoothly conveyed on the surface formed by the slide guide R301 and the slide guide L302. As a condition for this, as shown in FIG. 11, the outer peripheral surface of the upstream portion of the right kick roller 330R needs to be formed in a continuous arc or taper. The third and subsequent sheets are similarly aligned in the same manner as the second sheet, and after a predetermined number of sheets are aligned, a stapling operation is performed.
[0039]
When the stapling operation is completed in this way, the arm 331 rotates clockwise, so that the discharge upper roller 330a pivotally supported by the arm 331 moves downward to form the discharge roller pair 330 at the same time. The drive is connected to both rollers of the discharge roller pair 330, and the rotation of the discharge upper roller 330a and the discharge lower roller 330b is started. By this operation, the bundle of sheets S is nipped by the discharge upper roller 330a and the discharge lower roller 330b and conveyed onto the surface formed by the slide guide R301 and the slide guide L302.
[0040]
When the bundle of sheets S is completely discharged from the discharge roller pair 330, as shown in FIG. 4, the jogger motor M is rotationally driven to move the slide guide R301 and the slide guide L302 outward.
[0041]
Further, the stapled sheet bundle falls downward as shown in FIG. 4 when the interval between the supported slide guides 301 and 302 becomes near or wider than the width of the sheet. As a result, the sheet bundle falls to the sheet stacking unit 325 of the sheet post-processing apparatus and is stacked.
[0042]
In this reference example, the right kicking roller 330R and the left kicking roller 330L are symmetric, and therefore effective when the alignment direction perpendicular to the sheet conveyance direction is reversed from that of the reference example . You may delete the taper part of the part which a sheet | seat does not contact | abut.
[0043]
As described above, according to the first reference example, it is possible to provide a sheet post-processing apparatus with good sheet consistency.
[0044]
(First Embodiment)
A first embodiment of the present invention will be described with reference to FIG. The same components as those in the reference example described above are denoted by the same reference numerals, and description thereof is omitted. FIG. 8 is an explanatory diagram of the right kick roller of the first embodiment.
[0045]
Right kick-out roller 440 of the present embodiment, by configuring the cylindrical rather than ribs, such as the first reference example of the roller portion kicking of lower discharge rollers 330b, to obtain the same effect as in the first reference example ing.
[0046]
According to this configuration, compared with the rib configuration of the first reference example , since the portion that contacts the sheet is entirely composed of a surface, compared with the first reference example in which the taper portion is provided in the rib shape, the curl Can sufficiently handle large sheets, and the catch of the sheets can be reduced. Further, the left kicking roller is formed in a symmetrical shape.
[0047]
( Second reference example)
A second reference example will be described with reference to FIG. FIG. 9 is an explanatory diagram of the right kick roller of the second reference example, and the arrows indicate the sheet conveyance direction.
[0048]
The kicking roller of the above-described embodiment has a diameter of the roller that increases toward the end of the sheet in order to apply stiffness to a thin sheet. However, the right kick roller 550 of the present embodiment is of a type in which the diameters at both ends of the kick roller part do not change when the number of sheets stacked is small. When the number of stacked sheets is small, it is not necessary to increase the diameters of the rollers at both ends. That is, the cross-sectional shape may be the same.
[0049]
According to this configuration, since the shape of the roller can be simplified, the configuration of the mold can be simplified.
[0050]
(Other embodiments)
In the above-described embodiment, the printer is exemplified as the image forming apparatus. However, the printer is not limited to this, and may be a facsimile machine, a copying machine, or the like.
[0051]
【The invention's effect】
As described above, in the present invention, the upper roller and the lower roller that are separable from each other are formed, and the discharge roller pair for discharging the sheet and the upper roller of the discharge roller pair are retracted. An intermediate stacking unit that temporarily stacks the sheets, and an alignment unit that is movable in the width direction of the sheet perpendicular to the sheet conveying direction and that abuts and aligns with the widthwise end of the sheet on the intermediate stacking unit; Among the lower rollers, when the sheet is moved by the aligning means, the roller that comes into contact with the end portion in the width direction of the sheet is on the downstream side in the moving direction of the sheet within the range in contact with the moving sheet. Since the roller has a shape in which the radius of rotation of the roller increases, alignment is ensured without being caught.
[0052]
The roller is provided with a kick-out portion that kicks out the rear end of the sheet on the downstream side in the sheet conveying direction, and the kick-out portion is tapered so that the rotation radius decreases from the apex having the maximum rotation radius toward the upstream in the roller rotation direction. Therefore, it is possible to improve sheet alignment when post-processing the sheet.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view illustrating the overall configuration of a sheet post-processing apparatus and an image forming apparatus.
FIG. 2 is an enlarged view of a sheet post-processing apparatus 300. FIG.
FIG. 3 is an explanatory diagram of the operation of the slide guide at each position of the sheet.
FIG. 4 is an operation explanatory view of a slide guide.
FIG. 5 is a perspective view of a kicking roller.
FIG. 6 is an explanatory view of a rib of a kicking roller.
FIG. 7 is a cross-sectional view of a kicking roller.
FIG. 8 is an explanatory diagram of a right kick roller according to the first embodiment.
FIG. 9 is an explanatory diagram of a right kick roller of a second reference example.
FIG. 10 is a perspective view of a sheet post-processing apparatus.
FIG. 11 is an explanatory diagram of an intermediate stacking unit 300B.
FIG. 12 is an explanatory diagram of a conventional sheet post-processing apparatus.
[Explanation of symbols]
H ... Staple M ... Jogger motor R ... Roller S ... Sheet a ... Rib b ... Rib c ... Rib d ... Rib
100 ... Printer body
100A ... Main unit
101 ... Image forming section
120… Fixer
125… FD discharge part
130… discharge roller
150 Flapper
200 ... Feed cassette
300 ... Sheet post-processing device
300A ... casing part
300B ... Intermediate loading section
300C ... Bent part
301… Slide guide R
302 ... Slide guide L
303… Reference pin R
304… Reference pin L
305… Reference pin
320 ... Staple roller
322 Paddle
323… reference wall
325… Loading section
330… discharge roller pair
330K ... kicking out part
330L ... Left kick roller
330R… Right kick roller
330a ... Discharge upper roller
330b ... Lower discharge roller
331… arm
350… Paddle shaft
363… Inlet roller pair
390… Inlet sensor
440… Right kick roller
550… Right kick roller

Claims (5)

A sheet post-processing apparatus that has post-processing means and performs post-processing on a conveyed sheet,
A pair of discharge rollers configured to discharge the sheet, the upper roller and the lower roller being separable from each other;
An intermediate stacking unit that is formed by retracting an upper roller of the discharge roller pair and temporarily stacks sheets;
Alignment means that is movable in the width direction of the sheet perpendicular to the sheet conveyance direction and that contacts and aligns with the width direction end of the sheet on the intermediate stacking unit,
Among the lower rollers, when the sheet is moved by the aligning means, the roller that contacts the end in the width direction of the sheet is within the range of contact with the moving sheet and moves toward the downstream side of the moving direction of the sheet. The roller has a shape with a large turning radius, and the roller is provided with a kicking portion on the outer peripheral surface where the downstream side in the roller rotation direction kicks the trailing end of the sheet, and the kicking portion is upstream from the apex having the maximum rotation radius. A sheet post-processing apparatus, wherein the sheet post-processing apparatus is configured in a taper shape or a circular arc shape in which the radius of rotation decreases toward the side. A sheet post-processing apparatus that has post-processing means and performs post-processing on a conveyed sheet,
A pair of discharge rollers configured to discharge the sheet, the upper roller and the lower roller being separable from each other;
An alignment unit that supports the sheet discharged from the pair of discharge rollers and is movable in the width direction of the sheet orthogonal to the sheet conveying direction, and abuts and aligns with the end of the supported sheet in the width direction;
An intermediate stacking unit that is formed when a support surface for supporting the sheet of the aligning unit moves inward of the width of the sheet and the upper roller of the discharge roller pair is retracted, and temporarily stacks the sheet; Have
Among the lower rollers, when the sheet is moved by the aligning means, the roller that abuts against the widthwise end of the sheet rotates the roller toward the downstream in the sheet movement direction within a range that abuts against the moving sheet. The roller has a shape with a large radius, and the roller has a kick-out portion on the outer peripheral surface where the downstream side in the roller rotation direction kicks the rear end of the sheet, and the kick-out portion is upstream from the apex having the maximum rotation radius in the roller rotation direction The sheet post-processing apparatus is configured in a taper shape or a circular arc shape in which the radius of rotation decreases toward the center. The sheet post-processing apparatus according to claim 1 or 2,
The sheet post-processing apparatus according to claim 1, wherein a driving unit that drives the pair of discharge rollers releases the drive of the pair of discharge rollers when the upper roller is retracted. The sheet post-processing apparatus according to any one of claims 1 to 3,
The sheet post-processing apparatus according to claim 1, wherein the discharge roller pair has a comb-teeth configuration in which the upper roller and the lower roller are alternately arranged. In an image forming apparatus comprising: an image forming unit that forms a toner image on a conveyed sheet; and a post-processing unit that performs post-processing on a sheet on which an image is formed by the image forming unit.
The post-processing unit, an image forming apparatus which is a sheet post-processing apparatus according to any one of claims 1 to 4.

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