JP2010168202A - Sheet stacker and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet stacker and an image forming device capable of rapidly suppressing any uncontrolled motion of a sheet by a simple constitution with less number of components. <P>SOLUTION: The sheet stacker 1 includes first paddles 37a, 37b and second paddles 39a, 39b for allowing a sheet S to be abutted on a butting member 34 by abutting each rotary blade 41 on the sheet S discharged onto an elevating/lowering tray 9 from a sheet discharging unit 32, and stacks the sheets S on the tray 9 by abutting the sheets S on the butting member 34 with sheet ends being aligned to each other. The first paddles 37a, 37b, and the second paddles 39a, 39b are provided at a plurality of parts in the sheet width direction, and the angle of arrangement of the rotary blades 41 is deviated from each other. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a sheet stacking apparatus and an image forming apparatus that stack sheets on a tray that is provided so as to be movable up and down.

  In this type of sheet stacking apparatus, if the sheets discharged from the sheet discharge unit are discharged onto the tray in a curled state, there is a problem that the alignment of the sheets is deteriorated.

  As an example of dealing with such a problem, Patent Document 1 discloses that paddles are provided at a plurality of positions in the sheet width direction for curling the edge of the sheet, and the sheet is transferred while rotating blades are in contact with the upper surface of the sheet. Then, it is disclosed that the abutting member is brought into contact. In the technique of Patent Document 1, the plurality of paddles are arranged so that the rotation blades are arranged at the same angle, and the plurality of paddles are configured such that the rotation blades simultaneously hit the sheet.

  However, since the rotating blades of a plurality of paddles simultaneously hit the sheet, the time interval until the rotating blades contact the sheets one after another has been limited. For this reason, there is a problem that it is not possible to quickly suppress the violence of the paper discharged on the tray and the alignment of the paper is deteriorated.

  On the other hand, if it is attempted to reduce the time interval until the rotating blades successively hit the sheet, it may be possible to increase the number of rotating blades and narrow the arrangement angle, but the number of parts increases and the configuration is complicated. There is a problem of becoming.

  SUMMARY An advantage of some aspects of the invention is that it provides a sheet stacking apparatus and an image forming apparatus that can quickly suppress the sheet swaying with a small number of parts and a simple configuration.

  The present invention includes a paddle that abuts the rotating blades against the sheet discharged onto the tray that can be raised and lowered from the sheet discharging unit, and causes the sheet to abut against the abutting member. In the sheet stacking apparatus for stacking sheets with the sheet edges aligned on the tray, the paddles are provided at a plurality of positions in the sheet width direction, and the arrangement angles of the rotary blades are shifted from each other.

  According to the present invention, in the plurality of paddles, the arrangement angles of the rotating blades are shifted from each other. Therefore, the time interval at which the rotating blades abut on the sheet can be shortened without increasing the number of rotating blades, and the sheet can be moved quickly. Can be suppressed. Thereby, the sheet alignment accuracy can be improved with a simple configuration.

It is a perspective view of the paddle unit concerning a 1st embodiment. It is the perspective view which looked at the paddle unit shown in FIG. 1 from the other direction. It is AA sectional drawing shown in FIG. It is a perspective view which shows the structure of the sheet | seat discharge part provided with the paddle unit. FIG. 2 is a cross-sectional view illustrating a schematic configuration of a sheet stacking apparatus. It is a top view which shows the relationship between the position of a paddle and sheet size. It is a top view which shows the relationship between the position of a paddle and sheet size. It is a top view which shows the relationship between the position of a paddle and sheet size. It is a top view which shows the relationship between the position of a paddle and sheet size. It is a top view which shows the relationship between the position of a paddle and sheet size.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings.

  A sheet stacking apparatus (stacker) 1 according to the present embodiment is connected to an image forming apparatus main body 3 such as a copying machine and a post-processing apparatus 5 as shown in FIG. The formed sheet is introduced. The stack device (stacker) 3 can select an operation mode of a proof paper discharge mode, a straight paper discharge mode, and a shift paper discharge mode.

  The proof discharge mode is an operation mode in which the introduced sheet S is stacked by guiding the sheet from the sheet conveyance path L1 onto the proof tray 7. The straight sheet discharge mode is an operation mode in which the sheet discharge path L2 is guided to the post-processing apparatus 5 provided at the rear stage of the sheet stacking apparatus 1 through the sheet conveyance path L2. The shift discharge mode is an operation mode in which sheets are discharged and stacked on the shift tray (tray) 9 through the sheet conveyance path L3. In the shift paper discharge mode, as shown in FIG. 6, the sheets are stacked at different shift positions (described later) on the shift tray 9.

  As shown in FIG. 5, the shift tray 9 is placed on an elevator 11 that can move up and down. The four corners of the elevator 11 are suspended by a total of four timing belts 13, and each timing belt 13 is wound around a total of four timing pulleys 15. These timing pulleys 15 are linked by a gear train composed of a worm gear 17 and a plurality of gears, and are synchronously rotated by a driving force of a tray lifting / lowering motor 19 to lift and lower the elevator 11 together with the shift tray 9. . Since the power transmission system is via the worm gear 17, the shift tray 9 can be kept at a fixed position. When the elevator 11 is lowered to the lowest position, the shift tray 9 is placed on the carriage 21, and the sheets stacked on the shift tray 9 are carried out by the carriage 21 together with the shift tray 9.

  Reference numeral 37a denotes a paddle that rotates in the direction of arrow E in conjunction with the paper discharge roller 25 in the sheet conveyance path L3, and strikes and presses the rear end of the sheet S discharged onto the shift tray 9 downward. Rotate. Further, the sheet S stacked on the shift tray 9 pushes up the filler 27. The optical paper surface sensor S <b> 3 detects the stack height of the sheet S on the shift tray 9 based on the movement of the filler 27.

  When the paper surface sensor S3 is ON, the shift tray 9 is lowered by the tray lifting motor 19, and the tray lifting motor 19 is stopped after the paper surface sensor S3 is turned OFF. Therefore, each time the paper surface sensor S3 is turned on by the paper S stacked on the shift tray 9, the shift tray 9 is lowered by a predetermined distance.

  In FIG. 5, S1 is a sheet conveyance path sensor (hereinafter referred to as “entrance sensor”) provided at the sheet carry-in entrance for detecting passage of the sheet, and S2 is a sheet in the sheet conveyance path L3. Is a paper conveyance path sensor (hereinafter referred to as “paper ejection sensor”) for detecting the passage of the paper. A driven roller 29 urged by a spring is pressed against the paper discharge roller 25, and the sheet S is nipped between these rollers 25 and 29. Reference numeral 31 denotes an entrance roller that carries the sheet discharged from the image forming apparatus main body 3 by being driven.

  As shown in FIG. 4, the shift conveyance mechanism unit 50 moves the paper discharge roller 25 and the driven roller 29 in the direction of the arrow in FIG. 4 (the arrow G1 is the front side of the stack device 1 and the arrow G2 is the back side of the stack device 1). By moving the sheet by a predetermined amount, the sheet discharge position on the shift tray 102 is shifted to the near side or the far side. In FIG. 5, the back side is the back side in the direction penetrating the paper surface, and the near side is the near side of the paper surface in FIG.

  The paper discharge roller 25 and the driven roller 29 are connected to holders 51 and 52 that move in the arrow directions G1 and G2 and their connecting shafts 53 and 54, respectively. The paper discharge roller 25 is rotated by the motor 55 regardless of the movement position in the directions of the arrows G1 and G2. That is, the driven gear 56 attached to the paper discharge roller 25 is in the arrow direction G1 of the paper discharge roller 25 with respect to the drive gear 60 rotated by the motor (stepping motor) 55 via the gears 57 and 58 and the belt 59. , Meshing regardless of the movement position of G2.

  The holder 51 is provided with a rack gear 61, and the rack 61 is connected to the rotation shaft of the shift motor 63 via a pinion 62. The paper discharge roller 25 and the driven roller 29 are slid by a predetermined amount (about 10 mm) in the directions of the arrows G1 and G2 with the position in FIG. 4 as the center position. The home positions of the paper discharge roller 25 and the driven roller 29 are set to the paper discharge center position M (width direction center position) of the sheet discharge section 32 shown in FIGS. Detected by S4. By rotating the pulse motor 63 by a predetermined amount with reference to the home position, the paper discharge roller 25 and the driven roller 29 are moved to the shift position. A paddle unit 33 is provided below the paper discharge roller 25.

  Next, the paddle unit 33 will be described with reference to FIGS. The paddle unit 33 includes a rotation shaft 35, two first paddles 37a and 37b attached to the rotation shaft, and four second paddles 39a and 39b. An abutting member 34 (see FIGS. 1 and 4) that contacts the rear end in the sheet discharge direction and aligns the sheets S is provided on the sheet discharge portion 32 side of the paddle unit 33.

  As shown in FIGS. 6 to 10, the two first paddles 37 a and 37 b are provided at the center position in the width direction of the sheet discharge section 32 with the center position of the sheet discharge section 32 interposed therebetween.

  The four second paddles 39a and 39b are provided at two symmetrical positions on the left and right sides with the center position M as the symmetry axis. In the left and right second paddles 39a and 39b, as shown in FIG. 8, the second paddle (outer second paddle) 39a on the end side of the rotating shaft 35 is B5 side (long side) at each back side or front shift position. As shown in FIG. 9, the second paddle (inner second paddle) 39b located inside the dimension end (center position M side) and closer to the center position side than the outer second paddle 39a It is located near the inside of the B5 vertical (short side) dimension end at the shift position.

  The first paddles 37a and 37b and the second paddles 39a and 39b have the same configuration, but the mounting angles of the first rotary blades 41 are different, and the rotary blades 41 are in a shifted position.

  That is, as shown in FIGS. 1 and 2, the first paddles 37a and 37b and the second paddles 39a and 39b are respectively attached to the cylindrical body 43 and the outer periphery of the body 43 at intervals of 90 degrees. In addition, as shown in FIG. 3, the second paddles 39a and 39b are attached by shifting the position of the rotary blades by 45 degrees with respect to the first paddles 37a and 37b. . In FIG. 3, hatching indicates the rotary blades 41 of the first paddle 37 b, and those without hatches indicate the rotary blades 41 of the second paddle 39.

  Each paddle 37 a, 37 b, 39 a, 39 b has a pin 45 fitted in a key groove provided on the inner peripheral side of the barrel 43 and the outer periphery of the rotary shaft 35 to fix the rotation direction. A resin E-ring 47 attached to the direction end is fitted to fix the axial direction.

  The rotary blade 41 is made of a resin material, the thickness is adjusted by polishing one surface, and the other surface that is not polished is used as a contact surface with the sheet S.

  Next, the function and effect of the present embodiment will be described. In the sheet discharge section 32 (see FIG. 4), the sheet S discharged onto the shift tray 9 from the nip between the discharge roller 25 and the driven roller 29 is driven by the paddle unit 33 as shown in FIG. The rotating blades 41 of 37a, 37b, 39a, 39b abut against the trailing edge of the sheet S so as to wipe down, and the sheet is transferred to the abutting member 34 side while correcting the curl of the sheet edge. The sheet is aligned by abutting against the abutting member 34.

  According to the present embodiment, as shown in FIGS. 1 to 3, the first paddles 37 a and 37 b and the second paddles 39 a and 39 b are attached by shifting the position of the rotary blade 41. Since the rotary blades 41 of the second paddles 39a and 39b abut after the rotary blades 41a and 37b abut the sheet and before the next rotary blade 41 abuts, the rotary vane 41 contacts the sheet S. The contact time interval can be shortened and the sheet rampage can be quickly suppressed. That is, the sheet alignment accuracy can be improved with a simple configuration. Furthermore, it is possible to increase the transfer speed of the sheet S and apply it to the abutting member 34, thereby shortening the time required for paper alignment.

  In addition, the first paddles 37a and 37b and the second paddles 39a and 39b only have the same type of paddles attached at different angles of attachment to the rotary shaft 35, so the configuration is simple.

  In the present embodiment, the first paddles 37a and 37b are provided at the center in the width direction of the sheet discharge unit 32 (near the center line M in FIG. 6), and the second paddle 39b has the long side of the sheet size B5 in the discharge direction. When the sheet size is A3, A4, as shown in FIG. 6, both the rear shift and the front shift are all the first paddles 37a, 37b. And the second paddles 39a and 39b can be brought into contact with the sheet. When the sheet size shown in FIG. 7 is A4 portrait and A5 landscape, when the sheet size shown in FIG. 8 is B4, A5 landscape, and when the sheet size shown in FIG. The first paddles 37a and 37b and the inner second paddle 39a can be brought into contact with each other.

  In addition, when the sheet size shown in FIG. 10 is A5 vertical, the second paddles 39a and 39b cannot be in contact with each other in both the rear shift and the front shift, but at least the first paddles 37a and 37b can be contacted. The sheet can be corrected and transferred to the abutting member.

  That is, in the frequently used sheet sizes (A3, A4 horizontal, A4 vertical, A5 horizontal, B4, B5 horizontal), the paddle rotary blade 41 hits the center and both ends of the sheet S, and curling of the rear end can be suppressed. .

  Since the contact surface of the rotary blade 41 with the sheet S is a non-polished surface, it is possible to prevent the rotary blade 41 itself from being scraped by the contact between the sheet S and the rotary blade 41 of the paddle. It is possible to prevent the scraped dust from adhering to a location where the sheet S and the rotary blade 41 meet, and the stacked sheets S from being contaminated.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  For example, the arrangement angle of the rotary blades 41 of the first paddles 37a and 37b may be 90 degrees, the arrangement angle of the rotary blades of the second paddles 39a and 39b may be 120 degrees, and the first paddles 37a and 37b and the second paddles may be arranged. The arrangement angle may be different between 39a and 39b.

  Further, the mounting angle of the rotary blades 41 of the first paddles 37a and 37b may be set to 120 degrees, the mounting angle of the rotary blades of the second paddles 39a and 39b may be set to 120 degrees, and the mounting position with respect to the rotary shaft 35 may be shifted.

  The first paddles 37a and 37b and the second paddles 39a and 39b are not limited to two, but one first paddle 37a may be provided at the center, and one second paddle 39a may be provided on the left and right. The first paddle 37a may be provided on one of the left and right without providing the paddle, and the second paddle 39a may be provided on the other of the left and right.

DESCRIPTION OF SYMBOLS 1 Sheet stacking apparatus 3 Image forming main body 32 Sheet discharge part 33 Paddle unit 35 Rotating shaft 34 Abutting member 37a, 37b First paddle 39a, 39b Second paddle 41 Rotating blade S Sheet M Center in the width direction

JP 2008-24506 A

Claims (4)

The sheet discharged from the sheet discharge unit onto the tray that can be moved up and down is provided with a paddle that makes the rotating blades come into contact with the contact member and makes the sheet contact the contact member. In a sheet stacking device that stacks the edges aligned,
The paddle is provided at a plurality of locations in the sheet width direction, and the arrangement angle of the rotary blades is shifted from each other.   The sheet stacking apparatus is characterized in that the installation position of the paddle is provided in the center position in the width direction of the sheet discharge portion and in the vicinity of the inner end of the side that intersects the discharge direction of the sheet size B5 discharged from the discharge portion.   3. The sheet stacking apparatus according to claim 1, wherein the rotating blade is one whose surface is polished to adjust the thickness, and a contact surface with the sheet is a non-polishing surface.   An image forming apparatus comprising: the sheet stacking apparatus according to claim 1; and an image forming main body that supplies an image-formed sheet to the sheet stacking apparatus.

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