JP3619735B2 - Paper transport device and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine or a printer. In particular, the present invention relates to a paper transport device for transporting paper.
[0002]
[Prior art]
For example, an image forming apparatus such as a copying machine may be provided with a staple processing unit for collecting a predetermined number of sheets on which images are fixed and binding them with staples.
The staple processing unit has, for example, an intermediate tray that receives and stacks sheets conveyed from the image forming apparatus main body one by one. The plurality of sheets stacked on the intermediate tray are positioned by being pressed against a plate-like stopper provided at the end of the intermediate tray, and are bound by staples, and then sandwiched between rotating conveyance rollers and pressing rollers. Discharged.
[0003]
The pressing roller is provided so as to be displaceable with respect to the conveying roller by a driving mechanism including a motor, a gear mechanism, and the like so that it can approach and separate. When the sheets are stacked, the pressing roller is arranged away from the conveying roller, and approaches when discharging the sheets bound with staples.
Some stoppers are arranged at the end of the intermediate tray on the side from which paper is discharged. This stopper is provided by a drive mechanism including a solenoid, a link mechanism, and the like so that it can be displaced between a standing posture for positioning and a recumbent posture so as not to hinder paper discharge.
[0004]
[Problems to be solved by the invention]
Incidentally, there is a demand for downsizing of the image forming apparatus. In particular, since an image forming apparatus having a staple processing unit tends to be larger than an image forming apparatus having no staple processing unit, it is preferable to reduce the size of the staple processing unit.
For this reason, if it is assumed that the paper transport device related to the above-described pressing roller and stopper is downsized, it is not preferable that the paper is caught during transport even if the paper transport device can be downsized. It is also not preferable that the edges of the printed paper vary, since the appearance after post-processing deteriorates.
[0005]
Therefore, it is preferable that such a paper transport device can be further miniaturized while maintaining at least the same performance as the conventional one in terms of smoothly transporting the paper and positioning the paper with high accuracy.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the technical problems described above, and to provide a small paper transport device including a stopper and a pressing roller that can smoothly transport the paper and accurately position the paper, and an image forming apparatus including the same. It is to be.
[0006]
[Means for Solving the Problems and Effects of the Invention]
According to a first aspect of the present invention, there is provided a stopper that is displaceable to a first position that abuts and positions an end portion of a sheet stacked on a stacking base and a second position that allows conveyance of the sheet, and a stack. A pressing roller that can be displaced to a first position that applies a conveying force to the conveying roller to press the conveyed sheet toward the conveying roller and convey it to the stopper side, and a second position that is separated from the sheet, and the stopper to the first position. An elastic member that urges the pressing roller to the first position, an elastic member that urges the pressing roller to the first position, and first and second cams that are arranged coaxially and are driven out of phase. And the second cam drive the stopper and the pressing roller against the corresponding elastic member, respectively.And a sector gear which is driven to rotate by pressing the side surface by the first cam, and the stopper is displaced via the sector gear.There is provided a sheet conveying apparatus characterized by the above.
[0007]
According to the present invention, since the first and second cams are driven out of phase, the stopper and the pressing roller are moved to the first and second positions in conjunction with both cams, and the rotation angles of both cams. It can be displaced at a desired timing according to each.
For example, when the paper is positioned, the stopper is positioned at the first position in a biased state by the elastic member, so that the paper can be positioned with high accuracy. Further, the pressing roller is at the second position, and there is no possibility of disturbing the positioning of the paper. When the first and second cams are driven from this state, after the stopper is set to the second position, the pressing roller can be moved to the first position to start transporting the paper. As a result, the pressing roller can smoothly convey the paper without being disturbed by the stopper.
[0008]
In addition, since the pressing roller is urged by the elastic member, the paper can be transported more smoothly by the pressing force suitable for transport regardless of the thickness of the paper. Further, the first and second cams arranged on the same axis can simplify the structure for interlocking the stopper and the pressing roller, and further, for example, can share the drive source for both cams. As a result, the paper conveying device can be simplified and downsized..
[0009]
Also,Since the sector gear can enlarge the movement of the first cam and transmit it to the stopper, the first cam can be miniaturized while securing the necessary displacement amount of the stopper. As a result, the paper transport device can be further reduced in size.
Claim2The invention described in claim 11The swivel arm that rotatably supports the pressing roller at the tip thereof, and the swivel support shaft that fixes the base end of the swivel arm so as to be integrally rotatable.TogaProvided,The sector gear is rotatably supported by a turning support shaft.There is provided a sheet conveying apparatus characterized by the above.
According to the present invention, since the turning support shaft serves as both the sector gear and the turning arm support shaft, the paper conveying device can be further reduced in size.
[0010]
According to a third aspect of the present invention, in the paper conveying apparatus according to the second aspect, a cam follower that rotates integrally with the pivot support shaft is provided, and the cam follower is pressed by a second cam to press the pressing roller into the second roller. Disclosed is a paper transport device that is displaced to a position.
According to the present invention, since the movement of the second cam can be enlarged and transmitted to the pressing roller by the cam follower and the turning arm, the second cam can be reduced in size while ensuring the necessary displacement amount of the pressing roller. As a result, the paper conveying device can be further reduced in size..
[0011]
Also,Since the turning support shaft serves as the support shaft for the sector gear, the cam follower, and the turning arm, the paper conveying device can be further reduced in size.
Claim4The invention described in claim 11 to 3In the paper conveying device according to any one of the above, a side plate that rotatably supports the first and second cams is provided, and the first and second cams are disposed on both sides of the side plate. Provided is a paper transporting device.
[0012]
According to the present invention, the side plate can be used as a partition plate between the mechanisms for drivingly connecting the stopper and the pressing roller and the first and second cams. As a result of not having an unnecessarily wide gap between them, the sheet conveying device can be further miniaturized.
Claim5The invention described in claim 11 to 4An image forming apparatus including the paper transport device according to any one of the above, wherein the stack base is provided in a staple processing unit for binding a predetermined number of sheets on which images are fixed in a main body of the image forming apparatus. An image forming apparatus comprising: an intermediate tray provided; a stopper including a rear end stopper for positioning a rear end of paper stacked on the intermediate tray; and a transport roller being a roller for transporting to a paper discharge unit I will provide a.
[0013]
According to the present invention, since the structure for the stopper and the pressure roller provided around the staple processing unit can be reduced in size, for example, even when the space prepared in the main body of the image forming apparatus is small, the staple processing is performed. Can be built in the image forming apparatus main body.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an image forming apparatus provided with a sheet conveying apparatus according to an embodiment of the present invention will be described with reference to the drawings, taking a copying machine as an example. FIG. 1 is a front view showing a schematic configuration of a copying machine according to an embodiment of the present invention. In addition, in FIG. 1 and each figure mentioned later, the arrow which shows a direction is shown.
The copier 1 has an apparatus main body 2 as an image forming apparatus. A document feeder 5 is mounted on the upper surface 3 of the apparatus body 2. The document feeder 5 places the documents one by one on a transparent document placement window 4 provided on the upper surface 3 of the apparatus body 2. The document placed on the document placement window 4 is exposed and scanned by the reading unit 6 provided on the upper portion of the apparatus body 2. The reading unit 6 outputs a signal corresponding to the document.
[0015]
A lower part of the apparatus main body 2 has a sheet tray 7 on which a plurality of sheets are placed, a conveyance path 8 for taking out and conveying the sheet from the sheet tray 7, and a photosensitive drum based on a signal from the reading unit 6. 9 includes an image forming unit 10 for forming a toner image, a transfer unit 11 for transferring the formed toner image onto a sheet, and a fixing unit 12 for fixing the transferred toner image on the sheet. The sheet passes between the photosensitive drum 9 and the transfer unit 11 and the fixing unit 12, is sent upward along the conveyance path 8, and is then sent to the inner paper discharge unit 13. The inner paper discharge unit 13 is an intermediate portion in the vertical direction (arrow Z) of the apparatus main body 2, for example, a space provided between the reading unit 6 and the image forming unit 10. (Not shown) and extends rearward from this opening.
[0016]
In particular, the copying machine 1 incorporates a staple processing unit 14 in the apparatus main body 2 for binding a predetermined number of sheets on which images are fixed and binding them with staples. The staple processing unit 14 is disposed at a position above the inner paper discharge unit 13 and below the reading unit 6. Correspondingly, the conveyance path 8 is branched downstream of the fixing unit 12, one branched conveyance path 15 is directed to the inner paper discharge unit 13, and the other branched conveyance path 16 is a staple processing unit. Leading to 14. In order to selectively guide the paper to the inner paper discharge unit 13 and the staple processing unit 14, a displaceable paper discharge switching claw 17 is provided at a branch portion of the conveyance path 8.
[0017]
The staple processing unit 14 is operated in cooperation with the reading unit 6 and the image forming unit 10 according to a command from an operation panel (not shown). For example, the reading unit 6 reads a plurality of documents, and images corresponding to these documents are fixed on a plurality of sheets by the fixing unit 12 or the like. A plurality of sheets are conveyed one by one to the staple processing unit 14, where they are bound by staples to form a sheet bundle. Thereafter, the sheet bundle is discharged to an outer paper discharge unit 18 provided on the side of the apparatus main body 2.
[0018]
In the staple processing unit 14, for example, a sheet is carried from the conveyance path 16 to the intermediate tray 34 for performing staple processing in the left-right direction (arrow X) in FIG. 1. The rear end of the paper in the carry-in direction (which is the left end in FIG. 1) is aligned and stapled, and then the paper is carried out in the direction opposite to the carry-in direction.
As shown in the plan views of FIGS. 1 and 2, the staple processing unit 14 staples a plurality of sheets stacked at a predetermined position, conveys the sheet to a predetermined position for the stapler 40, and And a paper transport device 33 for carrying out the bound paper.
[0019]
The sheet conveying device 33 includes an intermediate tray 34 as a stacking table on which sheets fed out from the conveying path 16 are stacked and placed, and a trailing end stopper for positioning and aligning the trailing ends of the sheets stacked on the intermediate tray 34 (Hereinafter also referred to as “stopper”) 35, a front-end member 36 that pushes the front edge of the paper to align the paper along the stopper 35, and the width of the paper (dimension along the depth direction Y) A plurality of width adjusting members 37, 38, a conveying roller 41 for conveying the paper bound by the stapler 40 to the outer paper discharge unit 18, and a plurality of elastic members arranged to face the conveying roller 41; For example, there are two pressing rollers 42 and a displacement mechanism 44 for displacing the pressing rollers 42 and the stopper 35.
[0020]
In addition, a conveyance path 43 that guides paper from the intermediate tray 34 to the outer paper discharge unit 18 is provided. The conveyance path 43 intersects with the conveyance path 16 described above, and a switching claw 39 is provided at the intersecting portion so that the sheet passes along one of the conveyance path 16 and the conveyance path 43. .
The intermediate tray 34 is provided with an entrance of the transport path 43 at the left end, and the exit of the transport path 16 is disposed above the entrance. A rear end stopper 35 is disposed at the entrance of the conveyance path 43. Further, a conveyance roller 41 and a pressing roller 42 are disposed in the vicinity of the rear end stopper 35 and at a position inside the intermediate tray 34. The transport roller 41 is fixedly disposed above the left end portion of the intermediate tray 34 and is driven to rotate. On the other hand, the pressing roller 42 is rotatably supported below the conveying roller 41. The sheet is sandwiched between the pressing roller 42 and the conveyance roller 41 and is conveyed by the rotation of the conveyance roller 41.
[0021]
The pressing roller 42 can be displaced to a first position that applies a conveying force to the conveying roller 41 to press the stacked sheets to the conveying roller 41 side and convey them to the stopper 35 side, and a second position that is separated from the sheet. Is provided. The pressing roller 42 and the transport roller 41 cooperate with each other to transport the paper from the intermediate tray 34 toward the stopper 35. For this reason, the stopper 35 can be displaced to a first position where the end of the sheet stacked on the intermediate tray 34 is abutted and positioned and a second position where the conveyance of the sheet is allowed.
[0022]
The staple processing unit 14 staples a plurality of sheets as follows. In other words, in response to a command from the operation panel, each unit of the staple processing unit 14 is in a state where it can receive and position a sheet from the fixing unit 12. For example, the stopper 35 is set to the first position, the pressing roller 42 is set to the second position, the leading member 36 is positioned far from the stopper 35, and the width adjusting members 37 and 38 are positioned far from each other (see FIG. 7A). Further, the paper discharge switching claw 17 is switched to guide the paper to the intermediate tray 34. The switching claw 39 is switched so that the paper can be transported along the transport path 16 (see FIG. 7B).
[0023]
The sheets are fed and positioned one by one on the intermediate tray 34 through the transport path 16 and a predetermined number of sheets are superimposed. That is, one sheet is sent out to the intermediate tray 34 (see FIG. 7C). Each time, the leading member 36 moves toward the stopper 35 (see FIG. 7D), thereby bringing the trailing edge of the sheet into contact with the stopper 35 and aligning the trailing edge of the sheet. Next, the width adjusting member 37 on the back side moves to the near side, the sheet is brought into contact with the width adjusting member 38, and the end on the near side of the sheet is aligned (see FIG. 7E). 7C to 7E are repeated in this manner, a predetermined number of sheets are stacked, positioned at a predetermined position for stapling, and bound by the stapler 40 fixed corresponding to this position. (See FIG. 7F). The sheet bundle made up of a plurality of bound sheets is displaced to a position for carrying it out when both width adjusting members 37 and 38 are displaced toward the back side.
[0024]
Next, the switching claw 39 is switched so that the paper can be transported along the transport path 43. The stopper 35 is set to the second position. Then, the pressing roller 42 is set to the first position (see FIG. 7G). When the conveyance roller 41 is rotated in a predetermined direction, for example, clockwise in FIG. 1, the sheet bundle is carried out to the conveyance path 43 (see FIG. 7H) and received by the paper discharge unit 18 (see FIG. 7I). ).
In the copying machine 1 of the present embodiment, the above-described displacement mechanism 44 is simplified.
[0025]
As shown in the perspective view of FIG. 3 and the partial cross-sectional plan view of FIG. 4, the displacement mechanism 44 attaches the elastic member 50 that urges the stopper 35 to the first position and the pressing roller 42 to the first position. The stopper 35 and the pressing roller 42 are driven against the corresponding elastic members 50 and 60 by the elastic member 60 that is energized and the first and second cams 51 and 61 that are coaxially arranged and driven out of phase. First and second drive mechanisms 52 and 62, and a drive shaft 71 that rotationally drives the first and second cams 51 and 61 and is regulated at a predetermined rotational position.
[0026]
The drive shaft 71 and the transport roller 41 share a motor (not shown) as a drive source and a power transmission mechanism (not shown) such as a gear mechanism and a one-way clutch. When the motor is driven, the transport roller 41 rotates in a predetermined direction, for example, the clockwise direction in FIG. 1, whereby the paper for stapling is carried into the intermediate tray 34 through the transport path 16, or The stapled paper is carried out from the intermediate tray 34 to the conveyance path 43. The power transmission mechanism and the drive shaft 71 are drivingly connected via a gear 72 and a step clutch 73, and the drive shaft 71 is also driven by a motor.
[0027]
The step clutch 73 is a one-way spring clutch that transmits the rotation of the motor in a predetermined rotation direction. Even when the motor is driven, the rotation transmission is canceled and the drive shaft 71 that is the output side member is set in a predetermined manner. It can be positioned by stopping at the rotational angle position. The step clutch 73 is a cylindrical member that drives and connects the input side member and the output side member so as to be disconnected, and two protrusions 74 and 75 that are provided on the outer peripheral surface of the cylindrical member to stop the rotation of the drive shaft 71. And have. These protrusions 74 and 75 are arranged at different positions in the axial direction with a phase difference of 180 degrees, for example, and are engaged with a lever 77 that is displaced by a solenoid 76. When the projections 74 and 75 are not engaged with the lever 77, when the input side member rotates, the cylindrical member and the drive shaft 71 also rotate. On the other hand, when one of these protrusions is locked with the lever 77, the transmission of rotation is cut off at the rotation position corresponding to the locked state. For example, when the motor rotates and the solenoid 76 is turned on, the protrusion 75 is locked with the lever 77, and the drive shaft 71 stops at the first rotation position. When the solenoid 76 is turned off, the projection 74 is locked with the lever 77, and the drive shaft 71 stops at the second rotation position rotated 180 degrees from the first rotation position.
[0028]
The first and second cams 51 and 61 are, for example, substantially disc-shaped plate cams provided so as to be rotatable integrally with the drive shaft 71. Each of the cams 51 and 61 includes a contour for displacing the driven member on the outer peripheral surface of the disc, and the contour includes a portion 85 far from the rotation center 78 and a near portion 86. The cams 51 and 61 are displaced to displace the driven members brought into contact along the contours of the cams 51 and 61.
The first and second cams 51 and 61 have contours having substantially the same shape, and are driven with a phase shift. For example, the cams 51 and 61 are arranged at positions that are approximately 180 degrees out of phase with each other so that the distant portions 85 of the contours of the cams 51 and 61 are substantially opposite to each other across the rotation center 78. (See FIG. 6 (a)).
[0029]
The second drive mechanism 62 can integrally rotate the above-described second cam 61, a turning arm 64 that rotatably supports the pressing roller 42 via a support shaft 63, and a base end 65 of the turning arm 64. And a cam follower 67 that rotates integrally with the swivel support shaft 66. The cam follower 67 is a rod-shaped member as a driven member for the second cam 61, and is arranged so that the upper surface thereof can contact the outer peripheral surface of the second cam 61 and immediately below the rotation center 78. . The distance from the swing support shaft 66 to the support shaft 63 is from the portion of the cam follower 67 in contact with the cam 61 to the swing support shaft 66 so that the displacement amount of the cam follower 67 by the cam 61 is enlarged and transmitted to the pressing roller 42. Has been longer than the distance.
[0030]
The cam follower 67 is urged by the above-described elastic member 60 via the turning arm 64 and the turning support shaft 66 in the direction in which the cam follower 67 comes into contact with the cam 61. The elastic member 60 is formed of a torsion coil spring, and the turning support shaft 66 passes through the inside of the coil portion, and one end thereof is attached to the turning arm 64 and the other end is attached to a connecting plate 83 described later. The elastic member 60 urges the cam follower 67 and urges the pressing roller 42 toward the conveying roller 41.
[0031]
In the second drive mechanism 62, as shown in FIG. 5, as the second cam 61 rotates counterclockwise in FIG. 5, for example, the cam follower 67 and the swing arm 64 swing around the swing support shaft 66. It is displaced dynamically, and the pressing roller 42 is displaced in the vertical direction via these.
When the drive shaft 71 is in the first rotation position, the portion 85 of the second cam 61 that is far from the contour is positioned directly below the rotation center 78. At the second rotation position, the posture of the second cam 61 is reversed. As shown in FIG. 5B, when the second cam 61 is in the second rotation position, the cam follower 67 is biased so as to approach the portion 86 having a close contour of the second cam 61. The pressing roller 42 is in the first position. As shown in FIG. 5A, when the second cam 61 is rotated to the first rotation position, a portion 85 of the second cam 61 which is far from the contour pushes down the cam follower 67, and the pressing roller 42 is moved to the first position. 2 position.
[0032]
As shown in FIG. 3, the first drive mechanism 52 includes a first cam 51. The first drive mechanism 52 includes a sector gear 53 as a driven member that is rotated by pressing the side surface 57 by the first cam 51, and a plurality of, for example, two gears 54 and 55 that mesh with the sector gear 53. Is rotated and displaced. The number of teeth of the driven gear 55 is smaller than the number of teeth of the driving gear 54 so that the rotation angle of the two gears 54 and 55 is increased. The gear 55 and the stopper 35 are connected via a shaft 56 so as to be integrally rotatable.
[0033]
The sector gear 53 is formed in a sector shape, and is supported at the center of the sector shape so as to be relatively rotatable around the turning support shaft 66. The sector gear 53 has gear teeth 58 formed on a peripheral surface that forms a sector-shaped arc, and a side surface 57 that receives a force to rotate around the pivot support shaft 66. The side surface 57 is disposed so as to be in contact with the outer peripheral surface of the first cam 51 in the vicinity immediately below the rotation center 78 thereof. Further, the sector gear 53 has a pitch circle radius of the gear teeth 58 around the turning support shaft 66 of the sector gear 53 in contact with the cam 51 so that the displacement amount of the first cam 51 can be enlarged and transmitted to the gear 54. The arm length is longer. Further, the side surface 57 of the sector gear 53 is urged by the elastic member 50 toward the outer peripheral surface of the first cam 51.
[0034]
The elastic member 50 is formed of a torsion coil spring, and one end of the elastic member 50 is attached to the sector gear 53 and the other end is attached to the connecting plate 83 so that the turning support shaft 66 passes through the inside of the coil portion.
In the first drive mechanism 52, as the first cam 51 rotates counterclockwise in FIG. 1, for example, the sector gear 53 swings and displaces around the turning support shaft 66, and the gears 54 and 55 rotate. Through these, the stopper 35 is rotationally displaced within a range of approximately 90 degrees. The angular range in which the stopper 35 rotates is larger than the angular range in which the sector gear 53 swings.
[0035]
When the drive shaft 71 is set to the first rotation position, a portion 85 of the first cam 51 which is far from the contour is positioned directly above the rotation center 78, and at the second rotation position, the first cam 51 The posture is reversed. As shown in FIG. 6B, when the first cam 51 is in the second rotational position, the portion 85 of the contour of the first cam 51 that is far from the contour pushes down the side surface 57 of the sector gear 53, and the stopper 35 is 2 position. When the first cam 51 is rotated counterclockwise in FIG. 6, for example, the sector gear 53 is urged by the elastic member 50 to maintain contact with the first cam 51 while rotating. It rotates about the axis 66. As shown in FIG. 6A, when the first cam 51 is in the first rotation position, the portion 86 having a close contour of the first cam 51 contacts the side surface 57 of the sector gear 53, and the stopper 35 is 1 position.
[0036]
A support member that supports each part of the displacement mechanism 44 is provided. The support member includes a rear side plate 81 erected on the rear side, a front side plate (not shown) erected on the front side, and a connecting plate 83 that connects the front side plate and the rear side plate 81. . The rear plate 81 supports the first and second cams 51 and 61 via a drive shaft 71 in a rotatable manner. The first and second cams 51, 61 are arranged on both sides of the rear plate 81, and each part corresponding to both the cams 51, 61 is also arranged on both sides of the rear plate 81. A first cam 51, a sector gear 53, and gears 54 and 55 are arranged on the front side of the rear plate 81, and a second cam 61, a step clutch 73, and the rear side of the rear plate 81 are arranged. A power transmission mechanism for the transport roller 41 and a cam follower 67 are disposed.
[0037]
By driving the cams 51 and 61 while shifting the phases of the cams 51 and 61 as described above, the stopper 35 and the pressing roller 42 are moved to the first and second positions in conjunction with the cams 51 and 61, respectively. The cams 51 and 61 can be displaced at desired timings according to the rotation angles.
For example, at the time of positioning, as shown in FIGS. 3, 4, 5 (a) and 6 (a), the solenoid 76 is turned on, and the drive shaft 71 and the two cams 51, 61 are in the first rotation position. To be. Accordingly, the stopper 35 is set to the first position as described above, and the contact surface 87 stands up substantially perpendicularly to the upper surface of the intermediate tray 34. At this time, the stopper 35 is positioned at the first position in a biased state by the elastic member 50, so that the sheet can be positioned with high accuracy. Further, since the pressing roller 42 is stored below the intermediate tray 34 at the second position and is separated from the paper on the intermediate tray 34, there is no possibility of disturbing the positioning of the paper.
[0038]
At the time of paper conveyance, as shown in FIGS. 5B and 6B, the solenoid 76 is turned off, and the drive shaft 71 and the cams 51 and 61 are set to the second rotation position. Accordingly, the stopper 35 is set to the second position, and the contact surface 87 is flush with the upper surface of the intermediate tray 34 in the lying state. Then, the pressing roller 42 is set to the first position, and when the upper portion of the pressing roller 42 comes out from the upper surface of the intermediate tray 34, the pressing roller 42 pushes up the lower surface of the sheet, and the upper surface of the sheet is conveyed. It is made to contact with the roller 41. When the conveying roller 41 is driven, the sheet is smoothly conveyed without being interrupted by the stopper 35.
[0039]
In this manner, the pressing roller 42 that is elastically biased appropriately secures the necessary conveying force for the conveying roller 41 according to the thickness of the sheet sandwiched between the conveying roller 41. Can do. At this time, when the thickness of the sheet sandwiched between the pressing roller 42 and the transport roller 41 at the first position is thick, a gap corresponding to the thickness is opened between the cam follower 67 and the cam 61. Also good.
Further, since the pressing roller 42 is urged by the elastic member 60, the paper can be transported more smoothly by the pressing force suitable for transport regardless of the thickness of the paper.
[0040]
Thus, according to the present embodiment, as described above, the stopper 35 can position the sheet with high accuracy, so that the ends of the bundle of sheets bound by staples can be aligned and can be improved in appearance. Further, the pressing roller 42 can smoothly convey the paper.
Further, the first and second cams 51 and 61 arranged on the same axis can simplify the structure in which the stopper 35 and the pressing roller 42 are interlocked. Further, the drive sources of both the cams 51 and 61 are shared. Yes. In addition to this, the cams 51 and 61 and the conveying roller 41 share a motor as a drive source. As a result, the entire displacement mechanism 44, and consequently the sheet conveying device 33, the staple processing unit 14, and the copying machine 1 as the image forming apparatus can be simplified and downsized. Therefore, for example, the outer shape of the copying machine 1 can be reduced in size, the inner paper discharge unit 13 can be opened widely, and the paper can be easily taken out.
[0041]
Since the movement of the first cam 51 can be enlarged and transmitted to the stopper 35 by the sector gear 53 of the first drive mechanism 52 for the stopper 35, the first cam 51 can be reduced in size while ensuring the necessary displacement amount of the stopper 35. Can be As a result, the image forming apparatus can be further downsized.
By utilizing the cam follower 67 and the turning arm 64 that rotate integrally to drive the pressing roller 42, the movement of the second cam 61 can be expanded and transmitted to the pressing roller 42, so that the necessary displacement amount of the pressing roller 42 is ensured. However, the second cam 61 can be reduced in size. As a result, the image forming apparatus can be further downsized.
[0042]
Since the turning support shaft 66 also serves as a support shaft that supports the sector gear 53, the cam follower 67, and the turning arm 64, the image forming apparatus can be further reduced in size.
Also, as shown in FIG. 4, by arranging the first and second cams 51 and 61 on both sides of the rear side plate 81, the rear side plate 81 is moved to the stopper 35, the pressing roller 42, and the first and second cams. 51 and 61 can also be used as a partition plate between the mechanisms for driving and connecting them, so that it is not necessary to separately provide a partition plate or unnecessarily widen a gap between the mechanisms. The apparatus can be further downsized.
[0043]
Further, as described above, the present invention is applied to the rear end stopper 35 provided on the intermediate tray 34 of the staple processing unit 14 built in the apparatus main body 2 and the transport roller 41 for discharging the processed paper. It is preferable to do this. This is because the structure for the stopper 35 and the pressing roller 42 provided around the staple processing unit 14 according to the present invention can be reduced in size, so that the staple processing unit 14 can be reduced in size. Even when the space to be used is small, the staple processing unit 14 can be built in the apparatus main body 2. Here, the staple processing unit 14 is not limited to the above-described configuration. In short, any staple processing unit 14 may be used as long as it has a stopper 35 for positioning the rear end portion of the sheet and a transport roller 41 for paper discharge.
[0044]
In particular, the trailing edge of the sheet on the intermediate tray 34 is the staple processing section 14 in which the direction in which the sheet is carried into and out of the intermediate tray 34 is opposite and the trailing end of the sheet is positioned and stapled. Since the conveyance roller 41, the stopper 35, the stapler 40, and the like can be arranged together in the vicinity of the section, it is preferable for reducing the size of the staple processing section 14.
In addition, although the pair of cams 51 and 61 are separately formed and fixed to the shaft so as to be integrally rotatable, the present invention is not limited to this. For example, the pair of cams 51 and 61 may be integrally formed, for example, integrally with the drive shaft 71. In short, it is only necessary to have a member that becomes a cam having an outline that displaces the driven member that is in contact with the rotating member.
[0045]
Further, the sheet conveying device 33 of the present invention may be applied to an image forming apparatus such as a printer or a facsimile in addition to the copying machine 1. In addition, the paper transport device 33 may be applied to a post-processing device configured separately from the image forming device, for example, for staple processing.
In addition, various design changes can be made without changing the gist of the present invention.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing a schematic configuration of a copying machine according to an embodiment of the present invention.
FIG. 2 is a plan view showing a schematic configuration of a staple processing unit of the copying machine shown in FIG.
3 is a perspective view of a displacement mechanism of the copying machine shown in FIG. 1. FIG.
4 is a partial cross-sectional view of a plane of the displacement mechanism shown in FIG. 3;
5 is a front view for explaining the operation of the pressing roller of the displacement mechanism shown in FIG. 3. FIG. 5 (a) shows the state at the second position and FIG. The state at the time of conveyance in FIG.
6 is a front view for explaining the operation of the stopper of the displacement mechanism shown in FIG. 3; FIG. The state at the time of a certain conveyance is illustrated.
7 is a front view for explaining the operation of the staple processing unit shown in FIG. 1; FIG.
[Explanation of symbols]
1 Copying machine (image forming device)
14 Staple processing section
18 Outer discharge unit
33 Paper transport device
34 Intermediate tray (stack base)
35 Rear end stopper
41 Conveying roller
42 Press roller
50 Elastic member for urging the stopper
51 First cam
53 Sector gear
57 Side of sector gear
60 Elastic member for urging the pressing roller
61 Second cam
64 swivel arm
66 Rotating spindle
67 Cam Follower
81 Rear side plate
P paper
P1 Rear edge of paper

Claims (5)

A stopper that is displaceable to a first position that abuts and positions the end of the paper stacked on the stacking base and a second position that permits paper transport;
A pressing roller that is displaceable to a first position that applies a conveying force to the conveying roller to press the stacked sheets to the conveying roller side and convey the sheet to the stopper side, and a second position that is separated from the sheet;
An elastic member for urging the stopper to the first position;
An elastic member for biasing the pressing roller to the first position;
And first and second cams to be driven out of phase are arranged coaxially, each driven against the stopper and the pressing roller to the corresponding elastic member by the first and second cams, the A paper conveying apparatus comprising a sector gear that is driven to rotate by pressing a side surface by a first cam, and a stopper is displaced via the sector gear . In the paper conveying apparatus according to claim 1,
A swivel arm that rotatably supports the pressing roller at the tip;
A turning support shaft for fixing the base end of the turning arm so as to be integrally rotatable, and
The paper conveying apparatus , wherein the sector gear is rotatably supported by a turning support shaft . In the paper conveyance device according to claim 2 ,
Cam follower is provided to rotate integrally with the pivot member, the sheet conveying apparatus characterized by displacing the pressing roller in the second position the cam follower is pressed by the second cam. In the paper conveying apparatus in any one of Claims 1 thru | or 3 ,
A sheet transporting apparatus , comprising: a side plate rotatably supporting the first and second cams, wherein the first and second cams are disposed on both sides of the side plate . An image forming apparatus comprising the paper conveying device according to claim 1,
The stacking table includes an intermediate tray provided in a staple processing unit for collecting a predetermined number of sheets on which images are fixed in the image forming apparatus main body and binding them with staples, and a stopper is provided after the sheets stacked on the intermediate tray. An image forming apparatus comprising a rear end stopper for positioning an end, wherein the transport roller is a roller for transporting to a paper discharge unit.

Images