JP2003002511A - Paper after treatment device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent defective delivery by a delivering belt with delivering claws and stain on rear end of paper bundle by setting the delivering belt coping with narrowing of a space between staples at two positions in a treatment means stapling a paper bundle at two positions. SOLUTION: This paper after treatment device is provided with a delivering belt 75 arranged in a center part of a paper conveying passage of at least two pairs of stapling means 700 and rotatably stretched between a drive pulley 74A and a driven pulley 74B, and the delivering claw 76 formed as one body with the delivering belt 75 and having reinforcing part 76D reinforcing a back part of a paper butting surface 76A pushing the rear end part of a stapled paper bundle Sa in a conveying direction by rotation of the delivering belt 75 to deliver the paper bundle Sa.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic copying machine,
Receiving sheets discharged from image forming devices such as printers, facsimiles, and multifunction devices having these functions,
The present invention relates to a sheet post-processing apparatus having a function of stacking in a sheet storage unit, performing post-processing such as binding processing, and discharging the sheet to a sheet discharge unit.

[0002]

2. Description of the Related Art A large number of sheets on which an image is recorded by a main body of an image forming apparatus such as a copying machine, a printer, a facsimile, and a complex machine of these are gathered for each number of prints and bound by a binding means (stapler). A sheet post-processing device for binding together is provided. The sheet post-processing device is connected to and driven by the print function of the main body of the image forming apparatus.

As a sheet post-processing device for binding a bundle of a plurality of sheets as a set, Japanese Patent Laid-Open No. 2-276
691, No. 8-319054, Japanese Examined Patent Publication No. 5-4199
No. 1 publications and the like are disclosed.

[0004]

The conventional sheet post-processing apparatus for binding processing has the following problems.

(1) FIG. 9 is a sectional view of a sheet bundle discharging means in a conventional sheet post-processing apparatus. Paper stand 10
After the binding process is performed on the sheet bundle Sa stacked on the sheet stack 1, the sheet discharge Sa of the rotating discharge belt 102 presses the rear end portion of the sheet bundle Sa in the transport direction. Then, it is conveyed diagonally upward and discharged. Discharge belt 102
Is formed by a timing belt having a tooth profile and is stretched between a drive pulley 104 and a driven pulley 105.

[0006] The broken line in the figure shows the movement state of the paper ejection claw 103. The dashed-dotted line in the figure indicates the movement trajectory of the tip of the paper ejection claw 103. The paper tray 101 is provided with a slit through which the paper ejection claw 103 can project and move.

The base of the paper ejecting claw 103 is a discharge belt 102.
It is integrated by connecting to a part of. Drive pulley 10
4. In order to match the rotational curvature when passing through the outer peripheral surface of the driven pulley 105, the connection area of the base of the paper ejection claw 103 is set to the minimum necessary.

A bundle of sheets S stacked on the sheet table 101
The discharge belt 1 that rotates after the binding process is performed on a
The sheet stack S is formed by the sheet discharge nail 103 formed on a part of the sheet 02.
When the rear end of the sheet a in the conveying direction is pressed to be conveyed obliquely upward and moved to the ejecting unit, the sheet abutting surface of the sheet ejecting claw 103 has a load due to the weight of the sheet bundle Sa and the leading end of the sheet bundle is the ejecting unit. Due to the resistance force and the like when the sheet bundle Sa is brought into contact with the guide member, the sheet discharge claw 103 and the discharge belt 102 are bent, and the sheet bundle Sa is conveyed in a state of being tilted as shown by the solid line in the figure. When the paper ejection claw 103 falls down, the rear end portion of the sheet bundle Sa gets over the front end portion of the paper ejection pawl 103, resulting in poor conveyance. In the extreme case, the paper ejection nail 103
However, it falls down to the vicinity of the upper surface of the sheet mounting table 101 and cannot be conveyed.

(2) In the case of the flat stitching process in which the staples are driven at two locations near the side edge of the sheet bundle, when the spacing between the staples at the two locations is 165 mm, two stitches are provided between the two sets of binding means.
A book discharge belt 102 can be arranged. But,
If the distance between the two binding needles is 120 mm, 2
One discharge belt 102 is arranged in the middle of the binding means of the set. In this case, the load on one discharge belt 102 increases, the bending and the paper ejection claw 103 fall more, and the occurrence of conveyance failure is remarkable.

(3) By the rotation of the discharge belt 102,
The paper ejection claw 103 presses the rear end of the sheet bundle Sa to convey it.
It rotates along the drive pulley 104 and retracts from the upper surface of the sheet mounting table 101. Since the conventional paper ejection claw 103 uses chloroprene rubber (CR) or the like, abrasion is likely to occur at the rear end of the sheet bundle Sa with which the paper abutting surface of the paper ejection claw 103 abuts. When the paper ejection claw 103 moves while slidingly contacting the rear end portion of the sheet bundle Sa and retracts from the upper surface of the sheet mounting table 101, the paper ejection claw 103 slides and contacts the bottom surface side of the sheet bundle Sa to move the sheet bundle. Scratches on the rear edge. Further, the paper ejection claw 103 is worn, and the paper stack is contaminated.

[0011]

The above problems can be solved by a sheet post-processing apparatus, a sheet post-processing method, and an image forming apparatus of the present invention.

(1) Conveying means for conveying the sheets discharged from the main body of the image forming apparatus, a sheet storage section for aligning and stacking the conveyed sheets at a predetermined position, and binding for binding the aligned and stacked sheets In a sheet post-processing apparatus having a unit and a discharging unit for discharging the bound sheets, at least two sets of the binding units are arranged at the center of the sheet conveying path and are rotatably stretched between a drive pulley and a driven pulley. One provided discharge belt and a sheet abutting surface portion that is formed integrally with the discharge belt and that presses the trailing end portion in the transport direction of the bound sheet bundle by the rotation of the discharge belt to discharge the sheet bundle. A sheet post-processing apparatus comprising: a discharge claw having a reinforcing portion that reinforces a back portion.

(2) An image forming apparatus comprising an image forming apparatus main body composed of an image writing means, an image forming means and a sheet conveying means, and the sheet post-processing apparatus described in (1) above.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a sheet post-processing apparatus of the present invention,
An image forming apparatus including a sheet post-processing apparatus will be described with reference to the drawings.

[One Embodiment of Image Forming Apparatus] FIG. 1 is an overall configuration diagram of an image forming system including an image forming apparatus main body A, an image reading apparatus B, and a sheet post-processing apparatus FS.

The image forming apparatus main body A has a charging means 2, an image exposing means (writing means) 3, a developing means 4, and a transfer means 5 around a rotating image carrier (hereinafter referred to as a photoconductor) 1.
A, a charge removing unit 5B, a separating claw 5C, and a cleaning unit 6 are provided in the image forming unit. The charging unit 2 uniformly charges the surface of the photoconductor 1 and then the laser beam of the image exposing unit 3 is used. Exposure scanning is performed based on the image data read from the original to form a latent image, and the latent image is reversely developed by the developing means 4 to form a toner image on the surface of the photoconductor 1.

On the other hand, the paper S fed from the paper storage means 7A is sent to the transfer position. At the transfer position, the toner image is transferred onto the paper S by the transfer means 5A. After that, the electric charge on the back surface of the sheet S is erased by the charge eliminating unit 5B, separated from the photoconductor 1 by the separation claw 5C, conveyed by the intermediate conveying unit 7B, and subsequently heated and fixed by the fixing unit 8, and then discharged from the sheet discharging unit 7C. Is discharged.

When images are formed on both sides of the paper S,
The sheet S heated and fixed by the fixing unit 8 is branched from the normal sheet discharge path by the conveyance path switching plate 7D, switched back and turned upside down in the reverse conveyance 7E, and then discharged to the outside of the apparatus by the sheet discharge unit 7C. It The paper S discharged from the paper discharge unit 7C is sent to the receiving unit 11 of the paper post-processing device FS.

On the other hand, the surface of the photoconductor 1 after the image processing is cleaned by the cleaning means 6 downstream of the separation claw 5C to remove the developer remaining on the surface, to prepare for the next image formation.

An operation unit 9 for selecting and setting an image forming mode and a sheet post-processing mode is arranged on the upper front side of the image forming apparatus main body A.

On the upper part of the image forming apparatus main body A, an image reading apparatus B equipped with an automatic document feeder of a moving original reading type is installed.

[Paper Post-Processing Apparatus FS] FIG. 2 is an overall configuration diagram showing a conveyance path of the paper S in the paper post-processing apparatus (hereinafter referred to as a post-processing apparatus) FS according to the present invention.

In the post-processing apparatus FS, the first sheet feeding means 20A, the second sheet feeding means 20B and the fixed sheet discharging table 30 are arranged in the upper stage of the figure, and the punching means 40, the shift means 50 and the sheet discharging means are arranged in the middle stage. 60 are arranged in series on the same horizontal plane,
The binding processing unit (paper storage unit) 70 and the folding processing unit 80 are provided in the lower stage.
Are arranged in series on the same plane forming an inclined surface.

On the left side surface of the post-processing device FS in the drawing,
Shifted sheet S and edge-stitched sheet bundle S
An elevating and discharging tray 91 for stacking a and a fixed discharging tray 92 for stacking a processed sheet bundle Sb that has been folded in three or two are arranged.

The post-processing apparatus FS is installed with its position and height adjusted so that the receiving section 11 for the sheet S carried out from the image forming apparatus main body A coincides with the sheet discharging section 7C of the image forming apparatus main body A.

In the receiving section 11, the sheet S subjected to the image forming process from the image forming apparatus main body A, the interleaving sheet K1 for separating the sheet bundle supplied from the first sheet feeding means 20A, and the second sheet feeding means 20B. The cover sheet K2 supplied from

(Paper feeding means) The interleaving paper K1 contained in the paper feeding tray of the first paper feeding means 20A is separated by the paper feeding section 21,
It is fed and nipped by the transport rollers 22, 23, 24,
It is introduced into the receiving unit 11. Further, the cover sheet K2 stored in the sheet feeding tray of the second sheet feeding unit 20B is separated and fed by the sheet feeding section 25, nipped by the transport rollers 23 and 24, and introduced into the receiving section 11. .

(Punching means 40) A punching means 40 is arranged on the downstream side of the receiving section 11 in the sheet conveying direction. The punching means 40 has a movable punch that is driven up and down, and a fixed die that fits into the blade of the punch.

(Paper branching means) A paper branching means composed of switching means G1 and G2 is provided on the downstream side of the punching means 40 in the paper carrying direction. Switching means G1, G2
Is selectively branched to one of the three paper conveyance paths, that is, the first paper conveyance path for upper sheet ejection, the second paper conveyance path in the middle tier, and the third paper conveyance path in the lower tier by driving a solenoid (not shown).

(Simple paper discharge) When this paper transport is set, the switching means G1 shuts off the second transport path and the third transport path and opens only the first transport path.

The sheets S passing through the first conveying path are nipped by the conveying rollers 31 and ascended, discharged by the discharge rollers 32, placed on the fixed sheet discharge table 30, and sequentially stacked.

The fixed sheet discharge table 30 is so constructed that a maximum of about 200 sheets S can be stacked.

(Shift processing) When this transport mode is set, the switching means G1 retracts upward, the switching means G2 shuts off the third transport path, opens the second transport path, and allows the sheet S to pass. to enable. The sheet S is a switching means G
The sheet S is guided so as to pass between 1 and G2.

The image-formed sheet S discharged from the image forming apparatus main body A, the interleaf sheet K1 fed from the first sheet feeding means 20A, or the cover sheet fed from the second sheet feeding means 20B. The sheet K2 passes through the intermediate sheet passage of the switching units G1 and G2, is shifted by the shift unit 50 in the direction orthogonal to the sheet transport direction, and is then transported.

The shift means 50 carries out a shift process for changing the discharge position of the paper S in the carrying width direction for every predetermined number of sheets. The shift-processed sheets S are discharged by the sheet discharging unit 60 to the up-and-down sheet discharge tray 91 outside the machine and sequentially placed. The elevating and discharging tray 91 is configured to sequentially descend when discharging a large number of sheets S, and a maximum of about 3000 sheets (A4, A4
It is possible to store the sheet S of B5).

(Binding Processing) FIG. 3 is a sectional view of the post-processing unit 10 including the binding processing section 70 and the folding processing section 80.

When the binding process or the folding process is set in the operation section 9, the image-formed sheet S sent to the receiving section 11 of the post-processing apparatus FS after being subjected to the image forming processing in the image forming apparatus main body A is removed. After passing through the punching means 40, it is sent to the third conveying path below the switching means G2, is sandwiched by the conveying rollers 12, and is conveyed downward.

When a sheet S of a size larger than A4 or B5 is conveyed in the third conveying path, the solenoid S
D1 is driven, and the sheet S passes through the sheet passage 13A on the left side of the switching unit G3 in the figure, is nipped by the conveying rollers 14, and is conveyed downward. The paper S is further sandwiched and sent out by the registration rollers 15 on the further downstream side, is discharged to the space above the intermediate stacker (paper stacking table) 71 that is inclined, and the intermediate stacker 71 or the paper S stacked on the intermediate stacker 71. It contacts the upper surface of the and is transported diagonally upward.
After the trailing end of the sheet S in the traveling direction is discharged from the nipping position of the transport roller 14, the sheet S starts to descend due to its own weight, is transported on the inclined surface of the intermediate stacker 71, and is bound by stapling means (stapling means) 700. The rear end of the sheet S comes into contact with the sheet abutting surface of the first edge abutting member 72 for edge binding in the vicinity, and the sheet stops.

In the third conveyance path, small size sheets S of A4, B5 size or the like are efficiently and continuously conveyed to improve copy productivity, and movable switching means G3,
A paper passage 13B parallel to the paper passage 13A on the left side of the switching means G3 in the drawing is provided.

Solenoid S connected to switching means G3
When D1 is driven, the passage 13A is closed and the passage 13B is closed.
Open up.

The leading end of the first small-sized sheet S sent out from the conveying roller 12 passes through the sheet passing path 13B, comes into contact with the peripheral surface of the registration roller 15 in the rotation stopped state, and stops.

Next, the energization of the solenoid SD1 is turned off, the tip of the switching means G3 swings clockwise, the paper passage 13B is closed, and the paper passage 13A is opened. The leading edge of the second sheet S sent out from the transport roller 12 is
After passing through the sheet passing path 13A, it comes into contact with the peripheral surface of the registration roller 15 in the rotation stopped state and stops. Therefore, in the vicinity of the nipping position of the registration roller 15, the leading ends of the first sheet S and the second sheet S are overlapped and stopped, and a standby state is set.

At a predetermined timing, the registration roller 15 is driven to rotate, and the two sheets S are nipped and conveyed at the same time and discharged onto the intermediate stacker 71. After the 3rd one,
The registration rollers 15 discharge the sheets S one by one.

Reference numeral 73A denotes a pair of upstream side width matching members movably provided on both side surfaces of the intermediate stacker 71. The width alignment member 73A is movable in a direction orthogonal to the sheet transport direction, and when the sheet S is received on the intermediate stacker 71, the width alignment member 73A is opened wider than the sheet width and is transported on the intermediate stacker 71. When contacting the abutting member 72 and stopping, the side edge of the sheet S in the width direction is tapped to align the width of the sheet bundle Sa (width alignment). At this stop position, when a predetermined number of sheets S are stacked and aligned on the intermediate stacker 71, the binding unit 700 performs the binding process, and the sheet bundle Sa is bound.

A cutout is formed in a part of the sheet stacking surface of the intermediate stacker 71, and one discharge belt 75 wound around the drive pulley 74A and the driven pulley 74B is rotatably driven. It A discharge claw 76 is formed integrally with a part of the discharge belt 75, and the tip end portion thereof draws an elliptical locus X as shown by a dashed line in the drawing. The binding process of the sheet bundle Sa is performed by the ejection claws 76 of the ejection belt 75.
The rear end of the rear is held and placed on the discharge belt 75,
It slides on the mounting surface of the intermediate stacker 71 and is pushed up obliquely upward, and advances to the position where the discharge roller 61 of the discharge unit 60 is held. The sheet bundle Sa sandwiched by the rotating discharge rollers 61 is discharged and stacked on the elevating and discharging tray 91 (see FIG. 2).

FIG. 4 shows the case where various binding processes are executed.
7 is a plan view showing the arrangement of a sheet bundle Sa and a binding unit 700. FIG. FIG. 4A is a plan view showing a flat stitching process in which the staples SP are stapled at two locations in the center in the vicinity of the side edges of the sheet bundle Sa, and FIG. FIG. 4 is a plan view showing an edge stitching process of striking a staple SP at a position.
FIG. 7C is a plan view showing a saddle stitching process of striking the staples SP at two central portions of the sheet bundle Sa.

(Saddle Stitching Processing) As shown in FIG. 3, an intermediate stacker 71 on which the sheet bundle Sa is placed, a binding processing section 70,
The folding processing section 80 is arranged on the pedestal of the post-processing unit 10 and guided by the slide rails R1 and R2 so that it can be pulled out to the front side of the post-processing apparatus FS.

The binding means 700 has a two-divided structure including a stapling mechanism 701 and a staple receiving mechanism 702, and a sheet passage 77A through which the sheet S can pass is formed in the middle thereof.

Two sets of the binding means 700 are arranged in the direction orthogonal to the sheet conveying direction, and can be moved in the direction orthogonal to the sheet conveying direction by the driving means (not shown).

When the side-to-side binding process is set, the binding needles SP are struck by the two sets of binding means 700 at the two central locations in the sheet width direction of the sheet bundle Sa (see FIG. 4A).

When the end-stitching process is set, the stapling means 700 moves straight and swings to strike the stapling needle SP at one corner of the sheet bundle Sa corresponding to the sheet size (FIG. 4). (See (b)). When the saddle-stitching and center-folding processing is set, the staples SP are struck at two central portions of the sheet bundle Sa (see FIG. 4).
(See (c)).

FIG. 5 is a plan view showing the arrangement of the sheet bundle Sa of various sizes which have undergone the side-stitching process and the binding staple SP.

The interval between the staples SP that are stapled at two locations near the side edge of the sheet bundle Sa is 120 for all sheet bundle sizes.
It is set to mm.

When the saddle stitching process is set, the stitching means 70
The first abutting member 72 for end binding, which is arranged in the vicinity of the binding processing position of 0 (stitching position of the binding needle), retracts from the transport path, and at the same time, the second saddle-stitching and second-fold also downstream thereof.
The abutting member 78 moves in the direction of the extension surface of the sheet passing path 77A to block the sheet passing path 77B.

When the size (length in the carrying direction) of the cover sheet K2 and the sheet S is set or detected, the abutting unit that supports the second abutting member 78 is located below the sheet bundle Sa for saddle stitching. It moves to a position where it abuts the end and stops.

After the cover sheet K2 is placed at a predetermined stop position on the intermediate stacker 71, the sheet S carried out from the image forming apparatus main body A passes from the receiving section 11 of the post-processing apparatus FS to the third conveyance path. After passing, the cover sheets K2 placed on the intermediate stacker 71 are sequentially stacked on the upper surface of the cover sheet K2, and the leading end of the sheet S contacts the second abutting member 78 and is positioned.

After the final sheet S is positioned and placed on the intermediate stacker 71, a saddle stitching process is performed on the sheet bundle Sa including the cover sheet K2 and all the pages of the sheet S by the binding unit 700. By this saddle-stitching process, the binding needle SP is driven into the central portion of the cover sheet K2 and the sheet S in the transport direction. The staple SP is driven from the staple driving mechanism 701 on the staple driving side toward the staple receiving mechanism 702 on the staple clinching side.

(Folding Process) As shown in FIG. 3, a folding process unit 80 is arranged diagonally below the binding process unit 70. After the saddle stitching process, the second butting member 78 causes the sheet bundle S to move.
Linear movement is made in the downstream direction of the conveyance direction of a to open the passage downstream of the paper passage 77A. Movable second butting member 7
Reference numeral 8 regulates the stop position of the sheet bundle Sa at the time of the saddle stitching process at the upper position, and regulates the stop position of the sheet bundle Sa at the time of the center folding process at the lower position.

The saddle-stitched cover sheet K2 and the sheet bundle Sa consisting of the sheet S are conveyed obliquely downward in a sheet passage 81A formed by a guide plate (frame) 81, and then are brought to the second abutting member 78. The ends of the sheet bundle Sa in the transport direction come into contact with each other,
Stop in place. The second abutting member 78 can be moved to a predetermined position by the result of setting or detecting the sheet size and the driving unit.

Intermediate stacker 71 of the post-processing unit 10
The sheet passing paths 77A, 77B, 81A are formed on substantially the same plane and form a steep inclination of about 70 degrees.

The folding processing section 80 includes a protrusion plate 82, a pair of first folding lower rollers 83, a first folding upper roller 84, and a second folding upper roller 84.
Folding roller 85, transport belt 86, transport switching member 8
7 and the like, and enables the folding process and the tri-folding process of the sheet bundle Sa.

(Drive System of Binding Processing Section) FIG. 6 is a plan view of the essential parts of the binding processing section 70 and the paper discharge section.

The motor M1 drives and rotates the upper roller 61A of the discharge roller 61 via the belts B1 and B2, and drives and rotates the lower roller 61B of the discharge roller 61 via the belts B3 and B4. Further, the motor M1 drives and rotates the drive pulley 74A via the belts B3 and B5,
One discharge belt 75 is rotated.

The gear 74D fixed to the shaft end of the rotary shaft 74C of the drive pulley 74A meshes with the cam member 74E and rotates. The cam member 74E has a cam-shaped test portion. The photo sensor PS detects this portion to be inspected to set the standby position when the discharge claw 76 fixed to the discharge belt 75 rotated by the motor M1 is stopped.

The motor M2 moves the two upstream side width matching members 73A via the belt 731 in accordance with the sheet width. The motor M3 translates and rotationally moves the two binding units 700 via the belt 703 to set them at the binding position. The motor M4 moves the downstream width matching member 73B via the belt 732.

The first abutting member 72 is driven by a motor (not shown) to cut off and open the paper passage 77B. The second abutting member 78 is also driven by a motor (not shown), moves in the paper passages 77B and 81A, and is installed at a predetermined position.

(Paper bundle conveyance after binding processing) FIG. 7 (a)
FIG. 7 is a cross-sectional view of the vicinity of a discharge belt 75 showing a state in which the bundle of sheets Sa after edge-stitching processing is discharged.

The rear end portion of the sheet bundle Sa, which is positioned and stacked on the intermediate stacker 71 and subjected to the edge binding process, is fixed to one end of the discharge belt 75 which is rotated in the arrow direction by the forward rotation of the motor M1. The sheet is held by the ejected claws 76, slid on the intermediate stacker 71, and is pushed forward in the direction of the outlined arrow diagonally above and ejected.

Standby position HP of the discharge claw 76 during edge binding processing
1 is below the intermediate stacker 71 and the discharge belt 7
After the start of the rotation of the sheet bundle 5, the sheet bundle Sa is swung and quickly set to the position where the rear end portion of the sheet bundle Sa is brought into pressure contact. The standby position HP1 described above
Is arbitrarily positioned at a predetermined position at the time of detection by a photo sensor (not shown) and at the time measurement processing by a timer.

FIG. 7B shows a sheet bundle Sa after saddle stitching processing.
FIG. 9 is a cross-sectional view of the vicinity of a discharge belt 75 showing a state in which is conveyed to the folding processing unit 80 in the next step.

The rear end portion of the sheet bundle Sa, which has been positioned and stacked on the intermediate stacker 71 and has undergone saddle stitching processing, is at one end of the discharge belt 75 which is rotated in the arrow direction by the reverse rotation drive of the motor M1. The intermediate stacker 71 is pushed back by the fixed discharge claw 76 and the weight of the sheet bundle Sa.
It is slid above and pushed forward in the direction of the outlined arrow diagonally below and conveyed to the folding processing unit 80 in the next step.

Standby position HP of the discharge claw 76 during saddle stitching processing
After the rotation of the discharge belt 75, 2 is set at a position where the discharge belt 75 rotates and quickly comes into pressure contact with the rear end portion of the sheet bundle Sa of the maximum size in the sheet conveyance direction. The standby position HP2 can be arbitrarily set to a predetermined position by detection by a photo sensor (not shown) and timing processing by a timer.

(Discharge belt 75) The discharge belt 75 is
It is a timing belt having a tooth profile and has an endless shape. The discharge claw 76 is provided on a part of the outer peripheral portion of the discharge belt 75.
Are integrally formed. Discharge belt 75 and discharge claw 7
6 has a width of 6 mm, for example, and is made of urethane rubber. Discharge claw 76 made of urethane rubber
Has an advantage that when it comes into sliding contact with the rear end portion of the sheet bundle Sa, it is less worn than chloroprene rubber (CR) or the like used for the conventional paper ejection claw.

That is, the paper ejection claw 76 moves on the intermediate stacker 71 while slidingly contacting the rear end of the sheet bundle Sa, and the paper ejection claw 76 is discharged.
When the paper is retracted from the upper surface of the intermediate stacker 71, the paper ejection pawl 76
When the paper slides on the bottom surface side of the sheet bundle Sa and moves, the number of scratches is extremely small.

(Discharge Claw 76) FIG. 8 shows the discharge belt 75.
9 is a partial cross-sectional view showing the rotation of the discharge claw 76 of FIG.
8A shows a state before the discharge belt 75 starts discharging the sheet bundle Sa, and FIG. 8B shows a discharge state of the sheet bundle Sa by the discharge belt 75.

The discharging claw 76 is formed integrally with a part of the outer peripheral portion of the discharging belt 75, and is provided with a sheet abutting surface portion 76A, an upper end regulating portion 76B, a connecting portion 76C, a reinforcing portion 76D, a slit portion (cutting portion) 76E and the like. Are formed from.

The sheet abutting surface portion 76A presses the rear end portion of the sheet bundle Sa and conveys it to the sheet discharging means 60. The upper end regulation portion 76B regulates curl generated at the rear end portion on the upper surface side of the bundle of many sheets Sa.

The connecting portion 76C is a connecting portion for connecting the outer peripheral portion of the discharging belt 75 and the discharging claw 76, and is connected to at least one tooth portion 75A of the discharging belt 75 to form a thick shape. The connecting portion 76C having this thick shape is
It has sufficient strength required when the rear end of the sheet bundle Sa is pressed to be conveyed and discharged. Also, this connecting portion 76
C is set to a minimum length in which the discharge belt 75 has little bending when the drive pulley 74A and the driven pulley 74B rotate.

The reinforcing portion 76D has a sheet abutting surface portion 76A.
Is a thickened portion for reinforcing the back portion of the sheet, and is sufficient to prevent deformation by the pressing force when the discharging claw 76 presses the rear end of the sheet bundle Sa to convey and discharge the sheet. Have strength.

A slit portion 76E is formed between the bottom portion of the reinforcing portion 76D and the flat portion of the outer peripheral surface of the discharge belt 75. The slit portion 76E is, for example, a narrow gap having a slit width δ of about 0.5 mm, and is pressed against the flat portion of the outer peripheral surface of the discharge belt 75 when the sheet abutting surface portion 76A of the discharge claw 76 presses the sheet bundle Sa. To prevent the discharge claws 76 from falling.

The discharge belt 75 is provided at the bottom of the slit portion 76E.
Below the flat portion of the outer peripheral surface, there are a plurality of tooth portions 75B corresponding to the bottom portion of the reinforcing portion 76D.
Serves as reinforcement when the discharge claw 76 is pressed.

In the embodiment of the present invention, the paper post-processing apparatus connected to the copying machine main body has been described, but it is used by connecting to the image forming apparatus main body such as a printer, a facsimile machine, a multi-function machine, and a light printing machine. It can also be applied to a sheet post-processing device.

[0083]

As is apparent from the above description, the following effects can be obtained by the sheet post-processing apparatus and image forming apparatus of the present invention.

(1) When the rear end of the bundle of sheets in the conveying direction is pressed by the ejecting claws to be conveyed obliquely upward and moved to the ejecting section, a reinforcing section is provided on the back of the sheet abutting surface of the ejecting claws. With the provision, the bending of the paper ejection claw and the ejection belt is prevented, and the conveyance failure of the sheet bundle is prevented.

(2) In the case of the flat stitching process in which the staples are driven at two points of the sheet bundle, one sheet is discharged in the middle of the two stitching means corresponding to the case where the interval between the staples at the two points is reduced. Even if the load is increased when the belt is arranged, the reinforcing portion is provided on the paper discharge claw, so that the bending of one discharge belt and the collapse of the paper discharge claw are reduced, and the occurrence of conveyance failure is prevented.

(3) The rotation of the discharge belt causes the discharge claw to press the rear end of the sheet bundle for conveyance, and the rear end of the sheet stack due to the discharge claw generated when the sheet is retracted from the upper surface of the sheet mounting table. Scratches and stains on parts are eliminated.

(4) The sheet post-processing device connected to the main body of the image forming apparatus such as a copying machine or a printer performs desired digital processing by the main body of the image forming apparatus and performs processing such as single-sided recording, double-sided recording, and page editing. After the fixing process and the fixing process, the discharged sheet is processed at high speed, accurately and efficiently by the sheet post-processing apparatus of the present invention such as sheet conveyance, shift, edge stitching, side stitching, saddle stitching, and center folding. Be seen. The sheet discharged after being processed at high speed by the image forming apparatus main body is subjected to high speed post processing by the sheet post-processing apparatus of the present invention while maintaining high productivity.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an image forming system including an image forming apparatus main body, an image reading apparatus, and a sheet post-processing apparatus.

FIG. 2 is an overall configuration diagram showing a sheet conveyance path in a sheet post-processing apparatus according to the present invention.

FIG. 3 is a cross-sectional view of a post-processing unit including a binding processing unit and a folding processing unit.

FIG. 4 is a plan view showing an arrangement of a sheet bundle and a binding unit when performing various binding processes.

FIG. 5 is a plan view showing an arrangement of various sizes of sheet bundles subjected to the side-stitching process and a binding needle.

FIG. 6 is a plan view of a main part of a binding processing unit and a paper discharge unit.

FIG. 7 is a cross-sectional view of the vicinity of a discharge belt showing a state in which a sheet bundle after edge-stitching processing is discharged and a state in which a sheet bundle after saddle-stitching processing is conveyed to a folding processing unit.

FIG. 8 is a partial cross-sectional view showing rotation of a discharge claw of a discharge belt.

FIG. 9 is a sectional view of a sheet bundle discharging unit in a conventional sheet post-processing device.

[Explanation of symbols]

10 Post-processing unit 60 paper ejection means 70 Binding processing section 71 Intermediate stacker (paper loading table) 72 First abutting member 74A drive pulley 74B driven pulley 75 discharge belt 76 Discharge claw 76D reinforcement 76E slit part (cut part) 80 Folding section 91 Lifting / Discharging Table 700 binding means (stapling means) A Image forming apparatus body FS paper post-processing device (post-processing device) Sa paper bundle SD1 solenoid SP binding needle δ slit width

Continued front page    (72) Inventor, Masato Hattori             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company (72) Inventor Hirohiko Okabe             47, 1067 Wakamatsucho, Tokorozawa, Saitama Prefecture F-term (reference) 2H072 FB10 GA08 JA02 JA03                 3F049 AA10 BA02 BA11 LA03 LA05                       LA07 LB03                 3F054 AA01 AB01 AC02 AC03 AC05                       BA11 BB04 BE04 BG02 BH01                       BJ07 DA01                 3F108 GA02 GA03 GA04 GB01 HA02                       HA33

Claims (4)

[Claims] 1. A transport unit for transporting sheets discharged from the main body of the image forming apparatus, a sheet storage unit for aligning and stacking the transported sheets at a predetermined position, and a binding unit for binding the aligned and stacked sheets. And a discharge means for discharging the bound paper, the paper post-processing device being arranged at the center of the paper transport path of at least two sets of the binding means and rotatably stretched between the drive pulley and the driven pulley. One discharge belt formed integrally with the discharge belt, and the rotation of the discharge belt presses the rear end in the transport direction of the stapled sheet bundle and discharges the sheet abutting surface. And a discharge claw having a reinforcing portion for reinforcing the sheet. 2. The discharge claw is integrally formed with the discharge belt only at a connecting portion connected to the discharge belt, and a cut portion having a narrow gap is formed between the reinforcing portion and an outer peripheral surface of the discharge belt. The sheet post-processing apparatus according to claim 1, characterized in that. 3. The sheet according to claim 1, wherein the discharge claw is formed of a material that prevents rubbing stains generated by sliding contact with a rear end portion of the sheet bundle in the transport direction. Aftertreatment device. 4. An image forming apparatus main body comprising an image writing unit, an image forming unit, and a sheet conveying unit;
An image forming apparatus comprising the sheet post-processing apparatus according to any one of 3 above.