JP2003341930A - Sheet post-treating method and sheet post-treating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet post-treating method and a device therefor capable of preventing a drop in the appearance quality of a prepared book likely according to the conventional technique in which a swell of a thick bundle of sheets leads to a poor workmanship of the folding part when the bundle consists of a great number of sheets and is subjected to a middle folding process. <P>SOLUTION: The sheet post-treating method is to stack a plurality of sheets S delivered from an image forming device A and subject the stack to a middle stapling process and the middle folding process, wherein the central part in the carrying direction of the bundle Sa having undergone the middle stapling process is pressed by a folding plate 72 and intruded to a pinching position N of a first folding roller couple 71 so as to form a folded part a, and the bundle Sa treated with the middle folding process is stopped in the predetermined position, while a second folding roller 73 supported so that its rotary shaft 73A intersects obliquely the folded part a and movable in the direction perpendicular to the sheet carrying direction is travelled on the folded part a under applied pressure so as to strengthen the folded part a. <P>COPYRIGHT: (C)2004,JPO

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,
For sheets ejected from image forming apparatuses such as printers, facsimiles, and multifunction machines having these functions,
The present invention relates to a sheet post-processing device that performs post-processing such as punching processing, binding processing, and folding processing.

[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.

The paper folding machine described in Japanese Unexamined Patent Publication No. 59-230965 has a paper folding mechanism and a mechanism for crushing a fold portion of a sheet folded by the paper folding mechanism. The crushing mechanism has a base and a pressure roller that moves on the base in the fold line direction.

[0005]

In a conventional sheet post-processing apparatus for folding a bundle of sheets, when a saddle-stitched bundle of sheets is subjected to center folding by a pair of center folding rollers, folds are generated due to bulging of the bundle of sheets. The flattening of the part may be insufficient. In particular, when a thick sheet bundle made up of a large number of sheets is subjected to center folding processing, the bulging of the sheet near the fold is large.

If the pressure applied to the center folding roller is increased in order to strengthen the folds, wrinkles, stains, etc. occur on the sheet bundle, and the appearance quality of the produced booklet deteriorates.

In particular, when the folds of the sheet bundle that has undergone post-processing of saddle stitching and center folding are moved while being pressed by the fold strengthening means, tears are likely to occur near the binding needles of the sheet bundle.

[0008]

The above problems can be solved by the following sheet post-processing method and sheet post-processing apparatus of the present invention.

(1) In a sheet post-processing method for stacking a plurality of sheets discharged from an image forming apparatus to perform saddle stitching processing and center folding processing, a central portion in the transport direction of the saddle stitched sheet bundle is set. , While being pressed by the center folding plate member, pushed into the sandwiching position of the first folding roller pair to form a fold, and then, the center-folded sheet bundle is stopped at a predetermined position, and the rotary shaft is rotated with respect to the fold. Paper post-processing characterized in that the second folding roller, which is supported so as to be obliquely crossed and is movable in a direction orthogonal to the paper transport direction, is run while pressing the fold portion, thereby strengthening the fold portion. Method.

(2) In a sheet post-processing apparatus for accumulating a plurality of sheets discharged from the image forming apparatus to perform saddle stitching processing and center folding processing, a central portion in the conveying direction of the saddle stitched sheet bundle is It is supported by a center folding plate member to be pushed in, a first folding roller pair that sandwiches and conveys the bundle of sheets pressed by the center folding plate member to form a fold portion, and a rotation shaft in a direction oblique to the sheet conveying direction. A second folding roller that travels while pressurizing the folds of the center-folded sheet bundle by the center folding plate member and the first pair of folding rollers to strengthen the folds. A paper post-processing device characterized by:

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the sheet post-processing method of the present invention,
A sheet post-processing device will be described with reference to the drawings.

[Image Forming System] FIG. 1 is an overall configuration diagram of an image forming system including an image forming apparatus A and a sheet post-processing apparatus (hereinafter referred to as a post-processing apparatus) B. FIG. 2 is an external perspective view of the image forming system.

[Image Forming Apparatus] In the image forming apparatus A, a charging device 2 and an image exposing device (image writing unit) 3 are provided around a rotating electrostatic latent image carrier (hereinafter referred to as an image carrier) 1. , A developing device 4, a transfer device 5A, a charge eliminating device 5B, and a cleaning device 6 are arranged. The image forming unit
After the surface of the image carrier 1 is uniformly charged by the charging device 2, the latent image is formed by performing exposure scanning based on the image data read from the original by the laser beam of the image exposure device 3 to form a latent image. Is subjected to reversal development by the developing device 4 to form a toner image on the surface of the image carrier 1.

On the other hand, the sheet feeding cassettes 7A, 7B arranged in the middle stage of the image forming apparatus A, the large-capacity sheet feeding trays 7C, 7D arranged in the lower stage, the manual sheet feeding tray 7E arranged at the side, and the like are supplied. The recording sheet S that has been printed is registered by the registration roller 7
It is sent to the transfer position via F.

At the transfer position, the transfer device 5A transfers the toner image onto the recording sheet S. After that, the recording paper S is separated from the image carrier 1 by removing the electric charge on the back surface by the static eliminator 5B, transported by the reversal transport unit 9C, subsequently heated and fixed by the fixing device 8 and discharged by the discharge roller 9A. It

When images are formed on both sides of the recording paper S, the recording paper S heated and fixed by the fixing device 8 is branched from the normal paper discharge path by the transport path switching plate 9B.
After being switched back and turned upside down in the reversing / conveying unit 9C, it passes through the image forming unit again, forms an image on the back surface of the recording sheet S, passes through the fixing device 8, and is ejected outside the device by the paper ejection roller 9A. .

On the other hand, the surface of the image carrier 1 after image processing is
The cleaning device 6 removes the developer remaining on the surface to prepare for the next image formation.

[Post-Processing Device] FIG. 3 is an overall configuration diagram of the post-processing device B according to the present invention.

The post-processing apparatus B includes a receiving unit 10, a direct paper discharging unit 20, a cover paper feeding unit 30, a punching processing unit 40, a paper folding processing unit 50, a binding processing unit 60, and a sheet bundle center folding processing unit 7.
0, a paper discharge section 80.

Receiving Portion 10 The inlet 11 of the receiving portion 10 is installed at a position and height that match the paper discharge roller 9A of the image forming apparatus A.

Into the receiving section 10, the recording sheet S subjected to the image forming processing from the image forming apparatus A and the cover sheet K supplied from the cover sheet feeding section 30 are introduced.

The recording sheet S introduced into the entrance 11 is directly discharged by the transport path switching means G1 into the sheet discharge section 20 and the punching section 4.
It branches to either 0.

Direct Paper Discharging Section 20 When this paper transportation is set, the transportation path switching means G1 shuts off the transportation path to the punching processing section 40 and opens the transportation path directly to the paper discharging section 20.

The recording sheet S that directly passes through the conveying path of the sheet discharging section 20 is nipped by the conveying rollers 21 and rises, is discharged by the sheet discharging rollers 22, and is placed on the fixed sheet discharging table 23.
It is loaded in sequence. A maximum of about 200 recording sheets S can be stacked on the fixed sheet discharge table 23.

Cover sheet feeding section 30 cover sheet K accommodated in the feed tray of cover sheet feeding section 30
Are separated and fed by the sheet feeding means 31, and the transport roller 3
It is sandwiched by 2, 33 and 34 and introduced into the receiving unit 10. Hereinafter, the recording sheet S and the cover sheet K will be collectively referred to as the sheet S.
Collectively.

The sheet S branched by the transport path switching means G1 of the punching section 40 receiving section 10 is transported to the punching section 40 arranged at the uppermost stage of the post-processing apparatus B. Paper S
Passes through the inlet roller 41, is held by the gripper 42 that moves at the same linear velocity as the linear velocity of the outer peripheral surface of the inlet roller 41, and advances.

When the trailing edge of the sheet S passes through the nipping position of the entrance roller 41, the trailing edge of the sheet S becomes free and falls on the sheet loading table 43. After that, the leading edge of the sheet S held by the moving gripper 42 is moved to the sheet leading edge regulating member 4
By hitting the sheet 4, the gripper 42 releases the holding of the leading end of the sheet S. The leading edge of the sheet S whose holding of the leading edge is released falls by its own weight and quickly descends on the inclined sheet placement table 43.

The paper S placed on the paper table 43 is
It is pressed by the sheet leading edge regulating member 44 and comes into contact with the sheet abutting portion 47 of the punch 46 and stops. In the alignment process in the paper transport direction, the paper width alignment means 45 positions the paper S in the width direction. Subsequently, the perforator 46 punches a file hole h near the leading edge of the sheet S.

The punch 46 comprises a punch which is driven up and down by driving means, and a die which is fitted to the blade of the punch.

The trailing end of the perforated sheet S is pressed by the sheet ejection claw 48A fixed to the rotating sheet ejection belt 48 to move on the sheet mounting table 43 in the leftward direction in the drawing, and the sheet ejection roller is ejected. The sheet is sandwiched by 81 and placed on an elevating and discharging tray 82. Alternatively, the paper S branched by the transport path switching unit G2 is subjected to post-processing such as binding and folding.

The punching section 40 can also perform a shift process for moving the paper S in the paper width direction.

FIG. 4A is a perspective view of the sheet S punched by the punch 46. The sheet S on which the intermediate conveyance path portion binding process and the folding process are performed is downwardly converted by the conveyance path switching unit G2, and further moved rightward in the figure by the plurality of conveyance rollers R1, R2, and R3.
The transport path switching unit G3 switches the sheet S to one of the transport paths of the sheet folding processing unit 50 and the binding processing unit 60.

Paper folding processing unit 50 A plurality of folding rollers 5 are provided for the paper S that has passed through the transportation path above the transportation path switching means G3 and has advanced to the paper folding processing unit 50.
Various folding processes are performed by 1, 52, 53, 54.

The folded sheet S is conveyed to the sheet placing table 63 in the binding processing section 60, and is pressed by the sheet ejecting claw 68A fixed to the rotating sheet ejecting belt 68 to press the sheet placing table. The paper 63 is moved to the left in the drawing, is sandwiched by the paper discharge rollers 83, and is placed on the elevating paper discharge tray 82.

FIG. 4B is a perspective view of the sheet S that has been subjected to the center folding process, FIG. 4C is a perspective view of the sheet S that has been subjected to the Z folding process, and FIG. It is a perspective view of the processed paper S.

Stitching Processing Section 60 The binding processing section 60 stacks and aligns the sheets S and performs side stitching processing or saddle stitching processing.

FIG. 4E shows a sheet bundle S subjected to the side stitching process.
FIG. 4 (f) is a perspective view of a sheet bundle S subjected to saddle stitching processing.
It is a perspective view of a.

.. The paper S that has passed through the transport path below the side stitch processing transport path switching means G3 and has proceeded to the binding processing section 60 is transport rollers R4, R5, R
6, R7, passes through the inlet roller 61, is held by the gripper 62 which moves at the same linear velocity as the linear velocity of the outer peripheral surface of the inlet roller 61, and advances.

When the trailing edge of the sheet S passes through the nipping position of the entrance roller 61, the trailing edge of the sheet S becomes free and falls on the sheet loading table 63. After that, the leading edge of the sheet S held by the moving gripper 62 is moved to the sheet leading edge regulating member 6
By hitting the sheet 4, the gripper 62 releases the holding of the leading edge of the sheet S. The leading edge of the sheet S whose holding of the leading edge is released falls by its own weight, and quickly descends on the inclined sheet placing table 63.

The sheet S placed on the sheet table 63 is
It is pressed by the sheet leading edge regulating member 64 and comes into contact with the sheet abutting portion 67 of the side stitcher (side stitching means) 66A for side stitching and stops. In the alignment process in the paper transport direction, the paper width alignment means 65 positions the paper S in the width direction.

Each time a plurality of succeeding sheets S are sequentially stacked on the sheet mounting table 63 and carried in, the alignment in the sheet transport direction and the alignment in the sheet width direction are performed. When the stacking of the predetermined number of sheets is completed, the stapler 66A staples the binding needle SP near the leading end of the sheet S to form the sheet bundle Sa (see FIG. 4E).

The rear end of the side-stitched sheet bundle Sa is
It is pressed by the paper ejection claw 68A fixed to the rotating paper ejection belt 68 to move leftward in the drawing on the paper placing table 63, and is pinched by the paper ejection rollers 83 and placed on the elevating paper ejection table 82. It

.. Saddle stitching processing A saddle stitching device (saddle stitching means) 66B for saddle stitching is constructed in a two-part structure of a lower stapling mechanism 66B1 and an upper stapling mechanism 66B2, and a sheet S is placed in between. It forms a paper passage that can pass through.

When the saddle stitching process is designated, the sheet leading edge regulating member 64 moves to a predetermined position in the downstream direction of sheet conveyance corresponding to the sheet size and stops.

The sheet S having proceeded to the binding processing section 60 passes through the transport rollers R4, R5, R6, R7 and the entrance roller 61, and is transferred to the gripper 62 which moves at the same linear speed as the linear speed of the outer peripheral surface of the entrance roller 61. Hold and proceed.

When the trailing edge of the sheet S passes through the nipping position of the entrance roller 61, the trailing edge of the sheet S falls on the sheet mounting table 63. Then, the leading edge of the sheet S held by the moving gripper 62 abuts against the sheet leading edge regulating member 64, so that the gripper 62 releases the holding of the leading edge of the sheet S. The leading edge of the sheet S whose holding of the leading edge is released falls by its own weight, and quickly descends on the inclined sheet placing table 63.

The sheet S placed on the sheet table 63 is
It slides down on the inclined sheet placing table 63, contacts the sheet abutting portion 67, and stops. At the stop position of the sheet S, the sheet width aligning unit 65 positions the sheet S in the width direction.

A plurality of succeeding sheets S are successively stacked on the sheet mounting table 63, each time the sheet S is carried in, the sheet conveying direction is aligned,
When the width alignment is performed and a predetermined number of sheets have been stacked, the saddle stitcher 66B strikes the staple SP at the center of the sheet S to form the sheet bundle Sa (see FIG. 4F).

The rear end of the saddle-stitched sheet bundle Sa is
It is pressed by the paper ejection claw 68A fixed to the rotating paper ejection belt 68 to move leftward in the drawing on the paper placing table 63, and advances along the conveyance path below the conveyance path switching means G4 to fold the sheet bundle in the middle. It is conveyed to the processing unit 70.

Sheet bundle center folding processing unit 70 In the sheet bundle center folding processing unit 70, the saddle-stitched sheet bundle Sa is a first folding roller pair 71 and a center folding plate member (hereinafter referred to as a folding plate) 72. The center folding process is performed by.

In the center-folded sheet bundle Sa, the second folding roller (strengthening folding roller) 73 strengthens the fold portion a. The sheet bundle Sa that has been subjected to the center folding process has a sheet discharge belt 84.
Is discharged outside the machine.

[Folding of a bundle of sheets] -Structure of paper bundle center folding processing unit FIG. 5 is a front view of the sheet bundle half-folding processing unit 70.

The saddle-stitched sheet bundle Sa conveyed to the sheet bundle half-fold processing section 70 falls in the sheet passage 74A formed by the pair of guide plates 74, and the leading end of the sheet bundle Sa is dropped. It abuts against the abutting member 74B and stops. Abutting member 74
B is moved corresponding to the sheet size and regulates the stop position of the sheet bundle Sa during the center folding process.

The first folding roller pair 71 of the sheet bundle center folding processing unit 70 is a first folding upper roller (hereinafter referred to as an upper roller).
71A and first folding lower roller (hereinafter referred to as lower roller) 7
1B and.

The upper roller 71A and the lower roller 71B are supported by a pair of left and right pressing means which are substantially symmetrical. One of the pressing means is an upper roller 71A, a support plate 76A that rotatably supports the upper roller 71A and is swingable around a support shaft 75A, and is locked to one end of the support plate 76A. Spring 7 for urging 71A toward the clamping position
7A and.

The pressing means of the lower roller 71B is the support shaft 75.
B, a support plate 76B, and a spring 77B, and these members are substantially line-symmetrical to the pressing means of the upper roller 71A. The outer peripheral surfaces of the upper roller 71A and the lower roller 71B are made of a high friction resistance material. The upper roller 71A and the lower roller 71B are driven and rotated by a folding roller driving unit 701 described later.

Driving Mechanism of Sheet Folding Center Folding Section FIG. 6 shows a folding roller driving means (hereinafter referred to as a first driving means) 701 for rotating the upper roller 71A and the lower roller 71B of the sheet bundle centering folding section 70. FIG. 6 is a configuration diagram of a folding plate driving unit (hereinafter, referred to as a second driving unit) 702 that moves the folding plate 72. Note that the alternate long and short dash line in the figure indicates the pitch circle of the gear.

The motor M1 has gears g1, g2A, g2.
The lower roller 71B is driven and rotated through a gear train composed of B, g3A, g3B, g4, g5 and g6. Further, the motor M1 has gears g1, g2A, g2B, g3A, g3.
The upper roller 71A is driven and rotated through a gear train composed of B, g4, g7, g8, and g9.

The motor M2 rotates the eccentric cylindrical member 723 from the gear g10 via the drive transmission means. The eccentric cylindrical member 723 makes an eccentric motion about an eccentric shaft 724 as a rotation center. A roller 725 planted in the movable holding member 721 is movably transferred to the inner wall portion of the eccentric cylindrical member 723.

The movable holding member 721 is supported so as to be linearly reciprocable along two guide members 722 arranged in parallel with the fixed substrate. The rotation of the gear g10 causes the eccentric cylindrical member 723 to move eccentrically, whereby the roller 725 moves and the movable holding member 721 reciprocates linearly along the two guide members 722. The folding plate 72 fixed to the movable holding member 721 also integrally moves reciprocally.

Center-Fold Processing of Sheet Bundle FIG. 7 is a sectional view showing the center-fold processing step by the center-fold processing section 70 of the sheet bundle.

FIG. 7A is a sectional view showing a state in which the folding plate 72 presses the sheet bundle Sa so as to bring it into pressure contact with the upper roller 71A and the lower roller 71B.

In response to the center folding processing start signal, the folding plate 72 connected to the drive source projects to the left in the drawing from the sheet mounting surface. The folding plate 72 is, for example, in the form of a thin knife having a thickness of about 0.3 mm, and its tip has an acute angle.

In FIG. 7B, the folding plate 72 is the upper roller 71.
A shows a state in which the sheet bundle Sa has undergone center folding processing by entering a position beyond the nipping position N of the lower roller 71B. The front end portion of the folding plate 72, which projects straight to the left in the figure, protrudes from the sheet bundle S.
The central portion of a is pushed in, and the upper roller 7
1A, the nipping position N of the lower roller 71B is spread and separated.

In FIG. 7C, the folding plate 72 is the upper roller 71.
A shows a state in which the sheet bundle Sa subjected to the center folding process is ejected by the upper roller 71A and the lower roller 71B while retracting from the nipping position N of the lower roller 71B and returning to the initial position.

After the leading end of the folding plate 72 has passed the nipping position N of the upper roller 71A and the lower roller 72B, the folding plate 72 retracts and the central portion of the sheet bundle Sa is nipped by the upper roller 71A and the lower roller 71B. The fold line a is formed by being pressed.
The fold line a substantially coincides with the driving position of the staple SP on the sheet bundle Sa by the saddle stitching process.

FIG. 8A is a perspective view of a sheet bundle Sa after post-processing of saddle stitching and center folding, and FIG. 8B is a perspective view showing a state in which the post-processed sheet bundle Sa is opened. 8C is a schematic cross-sectional view of the sheet bundle Sa. The sheet bundle Sa created by the saddle-stitching process and the half-folding process has the first surface of the paper S facing outward, the second surface on the back side thereof, the first surface of the paper S on the inner side, and the paper on the inner side thereof. The second surface of S is arranged, and as shown in the drawing, the page bundle of a sheet bundle (booklet) Sa consisting of 8 pages can be aligned.

The sheet bundle Sa having the fold line a is carried out by the upper roller 71A and the lower roller 71B which are driven to rotate, and is ejected out of the apparatus by the sheet ejection belt 84.

Control of center-folding process of sheet bundle When performing center-folding process on a small number (1 to 3) of sheet bundle Sa for which saddle stitching process is not performed, first,
The driving of the motor M1 of the first driving means 701 shown in FIG. 6 is stopped, and the rotations of the upper roller 71A and the lower roller 71B are held in a stopped state. In this state, the driving of the motor M2 of the second driving means 702 is started to move the folding plate 72 forward from the standby position.

The tip of the folding plate 72 has a small number of sheets S
The fold line “a” of the sheet “a” is protruded, and the outer surface of the upper roller 71A and the lower roller 71B that are not rotating is pushed in the vicinity of the sandwiching position N while sliding the sheet surface into contact with the sheet bundle Sa at the same time. Formed (see FIG. 7).

The leading end of the folding plate 72 projects the fold portion a of the sheet bundle Sa to form an upper roller 71A and a lower roller 71B.
When it is slidably brought into contact with the outer peripheral surface of the upper roller 71A and is fed to the vicinity of the holding position N, the upper roller 71A,
The lower roller 71B is in sliding contact with the moving sheet S and is driven to rotate only in the sheet conveying direction (see FIG. 6).

A small number of sheets (2-5 sheets) subjected to saddle stitching processing
When the center folding process is performed on the stack of the sheet bundle Sa, the shift between the sheets during the folding process of the saddle-stitched sheet bundle Sa is larger than that of the unstitched sheet bundle Sa. Although a small amount causes misalignment of paper other than the binding portion, the above-described folding processing control is applied to a small number (2 to 5) of the sheet bundle Sa.

When performing center folding processing on a bundle of a large number (6 to 20 sheets) of saddle-stitched sheet bundles Sa,
It is difficult to push the thick sheet bundle Sa into the vicinity of the nip position N between the upper roller 71A and the lower roller 71B that are not rotating, like the folding control of the small number sheet bundle Sa described above. The folding plate 72 is advanced and pushed forward with respect to the bundle of a large number of saddle-stitched sheet bundles Sa, and is pushed in the vicinity of the nip position N between the rotating upper roller 71A and lower roller 71B, and the fold portion a is formed. Then, the sheet bundle Sa is formed.

The mode switching of the folding process of the small number of sheets bundle Sa or the folding process of the large number of sheets bundle Sa is performed by the sheet number signal of the image forming apparatus A and the sheet passage detecting means of the post-processing apparatus B. .

[Reinforcement of Folded Portion] FIGS. 9 to 12 are a perspective view, a sectional view and a plan view showing a process of forming and strengthening the fold portion a by the center folding process.

FIG. 9A is a perspective view showing the center folding step of the sheet bundle Sa that passes through the nipping position N between the upper roller 71A and the lower roller 71B of the sheet bundle center folding processing section 70.
9B is a sectional view and FIG. 9C is a plan view.

As described with reference to FIG. 7C, the folding plate 72 holds the upper roller 71A and the lower roller 71B at the nipping position N.
The sheet bundle Sa that has been subjected to the center folding process is ejected from the first folding roller pair 71 including the upper roller 71A and the lower roller 71B, and returns to the initial position.
8 (see FIG. 9B). A second folding roller 73 and a second folding roller guide member 79 are arranged on the front side in the traveling direction of the sheet bundle Sa and on the outer side in the sheet width direction.

When the sensor PS1 detects the passage of the leading end of the sheet bundle Sa, the drive of the motor M1 is stopped, the rotation of the first folding roller pair 71 including the upper roller 71A and the lower roller 71B is stopped, and the sheet bundle is Sa is stopped at a predetermined position.

Almost at the same time, the driving of the motor M3 is started and the second folding roller guide member 79 is swung upward.
The second folding roller 73 held on the upper surface of the second folding roller guide member 79 is moved above the fold portion a of the sheet bundle Sa, and further moved in the sheet width direction by a driving unit (not shown) to move the fold portion a. To the end of.

FIG. 10 is a perspective view, a sectional view, and a plan view showing a state in which the second folding roller moves up from the retracted position and moves to the end of the fold portion of the sheet bundle.

FIG. 11 is a perspective view, a sectional view, and a plan view showing a state in which the second folding roller travels while pressing the fold line portion of the sheet bundle.

The second folding roller 73 travels in the sheet width direction while pressing the fold portion a of the sheet bundle Sa, so that the fold portion a is firmly attached and reinforced.

FIG. 12A is a perspective view showing a state in which the sheet bundle Sa is discharged after the pressing process by the second folding roller 73, and FIG. 12B is a plan view.

After the second folding roller 73 pressurizes and strengthens the fold portion a of the sheet bundle Sa, the driving of the motor M1 is started, the upper roller 71A and the lower roller 71B rotate, and the sheet bundle Sa is discharged. It

[Control of Second Folding Roller] When the number of sheets in the sheet bundle Sa is set to a predetermined number or more (for example, four sheets or more), the second folding roller 73 is caused to run and the sheet bundle Sa is moved.
The fold line a is pressed. When the number of sheets in the sheet bundle Sa is, for example, three or less, the fold portion a is formed by only the upper roller 71A and the lower roller 71B.

Further, in accordance with the number of sheets of the sheet bundle Sa,
The traveling speed of the second folding roller 73 is variably controlled. That is, the traveling speed of the second folding roller 73 is increased in the case of the small number of sheets bundle Sa, and the traveling speed of the second folding roller 73 is decreased in the case of the large number of sheets bundle Sa. Control.

Further, in the case of a bundle of a large number of sheets Sa, the second folding roller 73 is reciprocated once or a plurality of times in the sheet width direction to strengthen the fold portion a.

As the number of sheets in the sheet bundle Sa increases, the crease portion a is less likely to be formed, but the time until the next sheet bundle Sa is completely stacked on the sheet bundle center folding processing unit 70 is increased. In the half-fold processing unit 70 for the sheet bundle, the second
The traveling speed and reciprocating motion of the folding roller 73 can be arbitrarily set,
It can be folded enough.

[Second Folding Roller Drive Mechanism] FIG.
It is a perspective view showing a drive mechanism of the second folding roller 73.

Rotation Mechanism The second folding roller 73 is rotatably held by the holder 731. The motor M4 fixed to the holder 731 is
The rotation shaft of the second folding roller 73 is rotated via the gear train (first driving means).

The holding body 731 is locked to the traveling body 733 via the pressing spring 732. The pressing spring 732 presses the second folding roller 73 via the holding body 731. A second folding roller unit is formed by the second folding roller 73, the holding body 731, the pressing spring 732, the traveling body 733, and the like.

The traveling mechanism 733 slides on two guide rods 734 and is supported so as to be linearly reciprocally movable in the width direction of the sheet bundle Sa. Two
Both shaft ends of the guide rod 734 of the book have side plates 735A and 735.
It is fixed to B.

A motor M fixed to one side plate 735A.
5 drives and rotates the drive roller 736A. A driven roller 736B is rotatably supported on the other side plate 735B. Drive roller 736A and driven roller 736B
The traveling member 733 is fixed to a part of the timing belt 737 around which the and are wound by a locking member 737A.

The driving roller 73 is driven by driving the motor M5.
6A is driven to rotate, the timing belt 737 is rotated,
The traveling body 733 linearly reciprocates along the two guide bars 734, and the second folding roller 73 held by the holder 731 reciprocates in the paper width direction.

The elevating mechanism side plate 735A is fixed to a part of the timing belt 738A rotated by the motor M6 by the locking member 738Aa, guided by the guide rod 739A, and moved up and down in the linear direction.

The side plate 735B is fixed by a locking member 738Ba to a part of the timing belt 738B rotated by the motor M7 synchronized with the motor M6, and is guided by the guide rod 73.
Guided by 9B, it is moved up and down in the vertical direction.

With this elevating mechanism, the second folding roller unit is raised and lowered, the second folding roller 73 is lowered from above the sheet bundle Sa, and the upper layer surface of the sheet bundle Sa is brought into pressure contact.

[Control of Traveling Speed of Second Folding Roller Unit] The peripheral speed V1 of the second folding roller 73 by the motor M4 and the second folding roller unit constituted by the second folding roller 73 and the like are conveyed by the motor M5. By controlling so that the linear velocity V2 traveling in the direction orthogonal to the direction becomes equal, slip between the sheet bundle Sa and the second folding roller 73 is prevented, and the fold portion of the sheet bundle Sa by the second folding roller 73 is prevented. It is possible to prevent wrinkles and damage from occurring in the sheet bundle Sa when strengthening a.

[Reinforcement of Fold Lines of Sheet Bundle by Second Folding Roller] First Embodiment of Second Folding Roller FIG. 14A shows a sheet bundle Sa and the second folding roller 73 of the first embodiment. 3 is a plan view showing the arrangement of FIG.

The rotation shaft 73A of the second folding roller 73 is rotatably supported by a bearing at an inclination angle θ with respect to a reference line b in a direction orthogonal to the fold line a of the sheet bundle Sa. The second folding roller 73 is urged by a pressing spring 732 shown in FIG. 13, and presses the fold portion a of the post-processed sheet bundle Sa that has undergone saddle stitching and center folding placed on the sheet bundle placement table 78. . The second folding roller 73 is rotated in parallel with the fold portion a of the sheet bundle Sa while being rotated by a driving unit (not shown).
Move straight in the direction of the outlined arrow shown.

The second folding roller 73 is made of a hard resin material,
Alternatively, it is made of a metal material and strongly presses the fold line a.

FIG. 14B is an explanatory diagram of the pressing force F acting on the sheet bundle Sa when the second folding roller 73 rotates and moves linearly.

Due to the rotation and linear movement of the inclined second folding rollers 73, the pressing force F pressing the fold portion a of the sheet bundle Sa is the horizontal component force Fa parallel to the fold portion a.
And a vertical component Fb orthogonal to the fold line a. The horizontal folding force Fa causes the second folding roller 73 to move along the fold line a and press the fold line a. The vertical component force Fb acts to push the fold portion a outward, so that the fold portion a can be pressed without causing wrinkles in the sheet bundle Sa.

Second Embodiment of Second Folding Roller In the second embodiment of the second folding roller, as shown in FIG.
The second folding roller 73 shown in is fixed to the second folding roller unit and is supported in a non-rotatable state. The second folding roller 73 supported by the second folding roller unit
Is moved in parallel with the fold line a of the sheet bundle Sa in the direction of the outlined arrow shown in the figure. The second folding roller 73 that moves
Is configured to push outwardly the fold portion a of the post-processed saddle stitching and center-folded sheet bundle Sa placed on the sheet bundle placement table 78, and linearly move and press the fold portion a to squeeze the fold portion a. Strengthen and flatten.

Third Embodiment of Second Folding Roller FIG. 14C shows a sheet bundle Sa and a second embodiment of the second embodiment.
FIG. 7 is a plan view showing the arrangement of folding rollers 73.

The rotation shaft 73A of the second folding roller 73 is rotatably supported by a bearing at an inclination angle θ with respect to a reference line b in a direction orthogonal to the fold line a of the sheet bundle Sa. The second folding roller 73 is urged by a pressing spring 732 shown in FIG. 13, and presses the fold portion a of the post-processed sheet bundle Sa that has undergone saddle stitching and center folding placed on the sheet bundle placement table 78. .

The length of the rotating body of the second folding roller 73 in the rotation axis direction is such that the locus width c by which the rotating body of the second folding roller 73 moves the fold line a in the inclination angle θ direction is the fold line of the sheet bundle Sa. The length is formed so as to cover the portion a with a margin.

The second folding roller 73 is linearly moved in the outlined arrow direction of the inclination angle θ direction with respect to the fold portion a while being rotated by the driving means (not shown). By the pressing force F in the direction of the inclination angle θ, the entire area of the fold portion a is pressed while pushing the fold portion a outward, so that the sheet bundle Sa is not wrinkled and the fold portion a is strengthened.

In the embodiment of the present invention, the paper post-processing device connected to the copying machine main body has been described. However, the paper post-processing device to be used by connecting to the image forming device such as a printer, a facsimile, and a multi-function peripheral is used. Is also applicable.

[0110]

As is apparent from the above description, the paper post-processing apparatus of the present invention has the following effects.

In a paper post-processing device in which a sheet bundle is folded in two by a pair of first folding rollers to form a fold portion, and then a fold portion is pressed by a second folding roller, the rotation axis of the second folding roller is changed to the fold portion. It is possible to strengthen and flatten the folds by arranging them at an inclination angle in the forming direction and moving the folds in parallel or at an inclination angle. Further, when the folds are strengthened, wrinkles, stains, deviations of the folds, and the like in the sheet bundle are eliminated, and the appearance quality of the produced booklet is improved.

[Brief description of drawings]

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

FIG. 2 is an external perspective view of the image forming system.

FIG. 3 is an overall configuration diagram of a sheet post-processing apparatus according to the present invention.

FIG. 4 is a perspective view of a sheet perforated by a perforator, a perspective view of a sheet subjected to center-folding processing, a perspective view of a sheet subjected to Z-folding processing, a perspective view of sheet subjected to three-fold inward winding, and side stitching. FIG. 3 is a perspective view of a processed sheet bundle and a perspective view of a saddle-stitched sheet bundle.

FIG. 5 is a front view of a center-fold processing unit for a sheet bundle.

FIG. 6 is a configuration diagram of a folding roller driving unit and a folding plate driving unit.

FIG. 7 is a cross-sectional view showing a step of a center folding process performed by a folding processing unit.

FIG. 8 is a perspective view of a sheet bundle that has undergone post-processing of saddle stitching and center folding, a perspective view of a sheet bundle in a state in which both sides are opened, and a schematic cross-sectional view of the sheet bundle.

FIG. 9 is a perspective view, a cross-sectional view, and a plan view showing a center-folding process of a sheet bundle in a folding processing unit.

FIG. 10 is a perspective view, a cross-sectional view, and a plan view showing a state in which the second folding roller moves up from the retracted position and moves to the end of the fold portion of the sheet bundle.

FIG. 11 is a perspective view, a cross-sectional view, and a plan view showing a state in which a second folding roller travels while pressing a fold portion of a sheet bundle.

12A and 12B are a perspective view and a plan view showing a state in which a bundle of sheets is discharged after a pressing process by a second folding roller.

FIG. 13 is a perspective view showing a drive mechanism of a second folding roller.

FIG. 14 is a plan view showing the arrangement of the sheet bundle and the second folding roller of the first embodiment, an explanatory view of the pressing force that acts on the sheet bundle when the second folding roller rotates and moves linearly, the sheet bundle and The top view which shows arrangement | positioning of the 2nd folding roller of 3rd Embodiment.

[Explanation of symbols]

60 binding section 70 Half-fold processing unit for sheet bundle 701 Folding roller driving means (first driving means) 702 Folding plate driving means (second driving means) 71 First Folding Roller Pair 71A First folding upper roller (upper roller) 71B 1st folding lower roller (lower roller) 72 Middle folding plate member (folding plate) 73 Second Folding Roller (Strengthened Folding Roller) 73A rotating shaft 731 holder 732 Pressing spring 74 Information board 78 Paper stack stand 79 Second folding roller guide member B Paper post-processing device (post-processing device) a Folded part θ inclination angle

Continued front page    (72) Inventor Tadahiro Takahashi             3-3 Hibarigaoka, Nishi-Tokyo, Tokyo F term (reference) 3F108 AA01 AB01 AC02 AC03 BA07                       BA09 CA02 CB03 CD07 GA03                       GB03 HA02

Claims (6)

[Claims] 1. A sheet post-processing method for stacking a plurality of sheets discharged from an image forming apparatus to perform saddle-stitching processing and center-folding processing, wherein a central portion in a conveying direction of the saddle-stitched sheet bundle is After being pressed by the center folding plate member and pushed into the sandwiching position of the first folding roller pair to form a fold portion, the center-folded sheet bundle is stopped at a predetermined position, and the rotary shaft is rotated with respect to the fold portion. A sheet post-processing method, characterized in that a second folding roller, which is supported so as to be obliquely crossed and is movable in a direction orthogonal to the sheet conveying direction, is run while pressing the fold portion to strengthen the fold portion. . 2. A sheet post-processing device for accumulating a plurality of sheets discharged from an image forming apparatus to perform saddle stitching processing and center folding processing, and pushes in a central portion in a conveying direction of the saddle stitched sheet bundle. Supported by a center folding plate member, a first pair of folding rollers for sandwiching and transporting the bundle of sheets pressed by the center folding plate member to form a fold portion, and a rotary shaft in a direction oblique to the sheet transport direction, The center folding plate member and the first
A sheet post-processing apparatus, comprising: a second folding roller that strengthens the fold portion by running while pressing the fold portion of the center-folded sheet bundle with a folding roller pair. 3. A second folding roller guide member for guiding the second folding roller so as to be vertically movable in the thickness direction of the sheet bundle at a position where the second folding roller is retracted outward in the width direction of the sheet bundle. The sheet post-processing apparatus according to claim 2, wherein the sheet post-processing apparatus is provided. 4. The control unit according to claim 2, further comprising a control unit that detects a leading end portion of the sheet bundle nipped and conveyed by the first folding roller pair and stops the sheet bundle near the second folding roller. Paper post-processing device. 5. The sheet according to claim 2, wherein when the number of sheets of the sheet bundle is set to a predetermined number or more, the second folding roller is run to press the fold portion of the sheet bundle. Aftertreatment device. 6. The sheet post-processing apparatus according to claim 2, wherein the traveling speed of the second folding roller is variably controlled according to the number of sheets in the bundle of sheets to be subjected to the center folding process.