JP2001019270A - Sheet folding treatment device and picture image formation device furnished with this device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent production of creases on a sheet bundle even in the case of folding the sheet bundle by continuously rotating a folding roller pair without stopping it once. SOLUTION: A sheet folding treatment device is furnished with a pair of rotor pairs 178 free to rotate by press fitting on each other and an ejection means 79 to eject a sheet bundle by bending it in a bent shape by pressurizing an intermediate part of the sheet bundle to nip parts of a pair of the rotor pairs 178, and a run off part 178h is formed by leaving a part in a direction in parallel with a shaft of a rotor and the rotating direction on an outer periphery of at least one rotor 178a (or 178b) out of a pair of the rotor pairs. When a pair of the rotor pairs start rotating, remaining parts 178g in the axial direction in a direction in parallel with the shaft of the remaining rotor make contact with each other by the run off part, and while a pair of the rotor pairs 178 rotate, remaining parts 178b2 in the rotating direction of a rotating direction of the remaining rotor sandwich the sheet bundle by the run off parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet folding apparatus for folding a sheet without causing wrinkles on the sheet, and a copier, a printer, and a printer provided with the apparatus.
The present invention relates to an image forming apparatus such as a facsimile, a composite device thereof, and the like.

[0002]

2. Description of the Related Art Conventionally, there is an image forming apparatus in which a sheet processing apparatus is connected to a main body of the image forming apparatus.

This sheet processing apparatus sequentially takes in the sheets on which an image has been formed by the image forming apparatus main body, binds the sheet bundle in the vicinity of substantially the center thereof with a stapler unit, and conveys the sheet bundle to a sheet folding processing apparatus in the sheet processing apparatus. It is designed to be folded.

The sheet folding apparatus comprises a pair of column-shaped folding rollers, a pushing means having a pushing plate, and the like, and pushes the bound portion of the sheet bundle to the nip portion of the folding roller pair by the pushing plate. Then, the folded sheet bundle is nipped and conveyed by a pair of folding rollers, folded in two, and discharged.

Thus, the sheet bundle discharged to the discharge tray is folded in two at the binding portion at the center of the sheet, and discharged in a bound state.

[0006]

However, since the folding roller pair of the sheet folding apparatus has a columnar shape, a clamping force is constantly applied to the sheet bundle from the time when the sheet bundle is folded until the end of conveyance. Distortion and misalignment accumulate in the bundle,
Wrinkles were sometimes generated in the sheet bundle.

In order to prevent the occurrence of wrinkles in the sheet bundle, as shown in FIGS. 34 to 39, the sheet bundle P protruded by the pushing plate 79a is eaten by a pair of folding rollers 78. After the sheet bundle P is folded by applying pressure (see FIGS. 34 and 35) and the sheet bundle P is conveyed to the conveying roller pair 9 on the downstream side, the pressure is released to remove the load applied to the sheet bundle P. (See FIGS. 36 and 37) to prevent the occurrence of wrinkles in the sheet bundle P.

However, in this configuration, since the pressure is released during the conveyance of the sheet bundle P, the conveyance force to the sheet bundle P is lost when the pressure reaches the pressure release point.

For this reason, it is necessary to always provide the transport roller pair 9 near the downstream side of the folding roller pair 78.

Further, in order to completely release the pressure, a part (flat portions 78aa, 78ba) where the pair of folding rollers 78 is completely separated is formed in a part of the pair of folding rollers 78, so that the pair of folding rollers 78 is always provided. Since the sheet bundle P cannot be rotated, it rotates when folding the sheet bundle P to nip the sheet bundle P, and when the sheet bundle P reaches the next pair of conveying rollers 9, the two folding rollers 78a and 78b are flattened. Part 78a
It is necessary to stop a and 78ba to oppose each other (see FIG. 37).

In this case, as shown in FIG. 38, the sheet bundle P being conveyed to the edge A of the folding rollers 78a, 78b that have stopped rotating (the boundary between the flat portions 78aa, 78ba of the rollers and the curved surface). Were rubbed, and the edge A had a large conveyance resistance.

In order to prevent this conveyance resistance, as shown in FIG. 39, when the folding roller pair 78 is stopped and the sheet bundle P is being conveyed, the portion where the folding roller pair 78 and the sheet bundle P come into contact is covered. It is necessary to dispose the folding roller pair guides 110, 110, and the configuration of the sheet folding apparatus becomes complicated.

Further, since the flat portions 78aa and 78ba are formed over the entire length direction of the folding roller pair 78, during the rotation of the folding roller pair 78, when the folding roller pair 78 transitions from the separated state to the nip state. There is a problem that a concentrated load is applied to the edge A and damages the surface of the pair of folding rollers 79.

According to the present invention, during folding and conveying of a sheet bundle,
A sheet folding processing apparatus having a simple structure, in which even if the folding roller pair is continuously rotated without being temporarily stopped, a wrinkle generated in the sheet bundle is reduced and the folding roller pair is less damaged. It is an object to provide an image forming apparatus provided with the device.

[0015]

According to the present invention, there is provided a sheet folding apparatus comprising: a pair of rotating members rotatable by pressing against each other;
The nip portion of the pair of rotating members includes a projecting unit that presses an intermediate portion of the sheet bundle and bends and projects the sheet bundle in a “<” shape. Inside, on the outer periphery of at least one of the rotating bodies, forming a relief portion leaving a part in the direction parallel to the axis of the rotating body and the rotating direction,
At the time of starting rotation of the pair of rotating bodies, the remaining axial parts in the direction parallel to the axis of the rotating body left by the escape portion contact each other, and during rotation of the pair of rotating bodies, The rotation direction remaining portions in the rotation direction of the rotating body that are left by the escape portion sandwich the sheet bundle.

In the sheet folding apparatus according to the present invention, the intermediate portion of the sheet bundle is bound by a binding member, and the relief portion is formed at a portion facing the binding member in the rotation direction of the rotating body. .

In the sheet folding apparatus according to the present invention, the intermediate portion of the sheet bundle is bound by a binding member, and the remaining portion in the rotational direction is formed at a position where the binding member has escaped.

In the sheet folding apparatus according to the present invention, a plurality of the remaining portions in the rotation direction are formed within a range of the width of the sheet bundle.

In the sheet folding apparatus according to the present invention, the remaining portion in the rotation direction may have at least one sheet within the width of the sheet bundle.
One each is formed on both sides outside the range of the sheet bundle width.

In the sheet folding apparatus according to the present invention, at least one of the pair of rotating bodies escapes from the other.

The sheet folding apparatus according to the present invention includes a home position detecting means for detecting a rotation start position of the pair of rotating members.

According to the image forming apparatus of the present invention, there is provided a sheet stacking unit for stacking sheets, an image forming unit for forming an image on the sheet supplied from the sheet stacking unit, and folding the sheet on which the image is formed. And any one of the above sheet folding processing apparatuses.

The sheet folding apparatus of the image forming apparatus according to the present invention is configured to fold the sheet with the image forming surface inside.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet folding apparatus according to an embodiment of the present invention and an image forming apparatus provided with the sheet folding apparatus will be described below with reference to FIGS.

FIG. 1 is a schematic front sectional view of a copying machine as an example of an image forming apparatus.

The copying machine E is composed of a main body A and a sheet processing apparatus B connected thereto.

The sheet processing apparatus B has a finisher unit C capable of sorting sheets of images recorded by the copying machine main body A by the number of copies, and a stitcher unit D capable of binding and folding and binding a plurality of sheets. ing. The sheet folding apparatus F is incorporated in the stitcher unit D.

First, the overall configuration of the copying machine E will be described, and then, the finisher unit C and the stitcher unit D constituting the sheet processing apparatus B will be described separately.
Finally, the sheet folding apparatus F will be described.

(Copier E) The copier main body A optically reads a document automatically fed from a document feeder 1 mounted on the upper portion of the main body A by an optical unit 2 and converts the information into a digital signal to form an image. It is sent to the forming means 3 to send plain paper or OH
The information is recorded on a sheet such as a P sheet.

A plurality of sheet cassettes 4 (only one is shown and others are not shown) are mounted in the lower part of the copying machine main body A, and accommodate sheets of various sizes. An image is formed (recorded) on the sheet conveyed by the conveying roller 5 from the sheet cassette 4 by the electrophotographic method in the image forming unit 3.

That is, the copying machine E irradiates the photosensitive drum 3b with laser light from the light irradiating means 3a based on the information read by the optical means 2 to form a latent image, and develops the latent image with toner to form a sheet. After the transfer, the sheet is conveyed to the fixing means 6 and permanently fixed by applying heat and pressure.

The copier E feeds the sheet to the sheet processing apparatus B in the single-sided recording mode. In the case of the double-sided recording mode, the sheet conveyed to the retransmission path 7 by switchback and the sheet recorded on one side
The sheet is conveyed to the sheet processing apparatus B after forming an image on the other surface.

The sheet is fed in the sheet cassette 4
Not only from the multi tray 8 but also from the multi tray 8.

The finisher unit C (see FIG. 2) of the sheet processing apparatus B can perform a discharge process according to each mode such as an offset mode and a staple mode in addition to a normal discharge mode when discharging a sheet. Has become.

In the offset mode, when the sheets are sorted and discharged by the number of copies, the side guide 11 is moved when the first sheet of each portion is discharged, and the sheet width is shifted by a predetermined amount. (In the direction orthogonal to the sheet conveyance direction), the first sheet is discharged to a position shifted from the normal processing apparatus, and the second and subsequent sheets of each part are discharged to the normal position. This is an operation mode in which the sheet is discharged so that each boundary can be recognized.

However, if there is no space for moving the sheet by a predetermined amount with respect to the sheet width direction size, the reference guide is retracted below the staple tray 12, which is a temporary stacking means, so that a sufficient amount of sheet movement is ensured. It has become.

The staple mode is an operation mode in which, when sorting and discharging each copy, stacking and alignment are performed on the staple tray 12, the staples are stapled by the stapler 13, and binding and discharging are performed for each copy. is there.

The finisher unit C can perform two-sheet discharge control capable of simultaneously discharging two sheets in addition to the normal discharge control for discharging sheets one by one when discharging sheets. ing. This two-sheet ejection control
The buffer path 1 provided in the finisher unit C for the sheet sent from the copying machine main body A to the sheet processing apparatus B
4 is an operation control in which two sheets are retained at the same time, and two sheets are discharged simultaneously while being overlapped with the next discharged sheet.

On the other hand, the stitcher unit D (see FIG. 3) in the sheet processing apparatus B aligns the sheets discharged from the copying machine main unit A by the number of copies, staples them with a staple unit, and folds the sheets into two. The book is then bound.

In brief, the sheet discharged from the copying machine main body A is transferred to the vertical path 60 of the stitcher unit D.
And the sheets are stacked and aligned by the number of copies so that the lower end of the sheet abuts against the stopper 62.
The stapling is performed at two places at the center position in the sheet length direction (sheet conveying direction).

Next, the stopper 62 is moved downward to move the sheet bundle P so that the binding position reaches the nip position of the folding roller pair 178. The sheet bundle P is pushed by the pushing plate 79, and the sheet bundle P is moved. The nip is conveyed by a pair of folding rollers 178 so as to be folded in two at the binding position.

As a result, the sheet bundle P bound at the center in the sheet length direction and folded and bound in two is formed.
Is discharged onto the stacking tray 106.

(Offset Ejection Processing) As described above, the finisher unit C can perform the sort processing in the offset mode. In this mode, as shown in FIG. When the number of copies is discharged and the number of copies is discharged, the first sheet of each part is shifted in the sheet width direction from the second and subsequent sheets, and the boundaries between the parts are clarified.

(Stitcher Unit D) Next, the stitcher unit D in the sheet processing apparatus B (see FIG. 3)
The sheet ejected from the copying machine main body A passes through the path guide 6
The sheet is conveyed into a vertical path 60 composed of Oa and 60b, bound by the stapler unit 61 at the center of the sheet, and then folded and discharged.

The sheet P discharged from the copying machine main body A is
By the operation of the first flapper 21, the stitcher unit D
Is fed to the vertical path 60, and the lower end thereof is brought into contact with the stopper 62 to be stacked and aligned. An upper roller pair 63 serving as a conveying means is provided above the vertical path 60, and a plurality of flappers 64 are provided downstream of the upper roller pair 63. The flapper 64 includes two first flappers 64a and a second flapper 64b, and can selectively switch the transport path according to the size of the sheet P.

The movable guide 6 is located near the flapper 64.
5 are provided. The movable guide 65 includes an urging means 65
a, the vertical path 6 is urged toward the flapper 64.
0 of the transport path.

The movable guide 65 exposes the inside of the vertical path 60 in the vicinity of the flapper 64 by gripping and rotating the handle 65b so that a jam sheet can be processed.

A plurality of sheet sensors 66 are provided at positions facing the flapper 64 via the vertical path 60.
The first upper sensor 66a is located between the upper roller pair 63 and the first flapper 64a, and the second upper sensor 66a is located at a position facing the first flapper 64a.
A third upper sensor 66c is provided at a position facing the upper sensor 66b and the second flapper 64b. These sheet sensors 66 are sensors that detect the presence or absence, or the leading or trailing end, of the passing sheet P.

(Lower Roller Pair 67) A stapler unit 61 described later is provided substantially at the center of the vertical path 60.
An anvil 61d is provided at a position facing the stapler unit 61 via the vertical path 60. Downstream of the stapler unit 61, a lower roller pair 67 as a transport unit is provided. The lower roller pair 67 includes a driving roller 68 as a driving rotating body to which a driving force is transmitted from a driving source (not shown), and a pickup roller 69 as a moving rotating body that presses a sheet against the driving roller 68 and rotates following the sheet. Have been.

As shown in FIG.
Is attached to one end of the transport roller arm 69a. The other end of the transport roller arm 69a is rotatably supported by a path guide 60b of the vertical path 60 by a rotating shaft 69b. An elastic member 69c is attached between a substantially central portion of the transport roller arm 69a and the vertical path 60. The elastic member 69c presses the pickup roller 69 against the drive roller 68.

On the other hand, the transport roller arm 69a is provided with a compression release arm 70 which can be driven by a solenoid (not shown).
8 can be separated. Thus, the pickup roller 69 can be displaced between a position where the sheet is pressed against the drive roller 68 and a separation position where the sheet is separated from the drive roller 68.

(Pressing Operation of Pickup Roller 69) When the sheet P is conveyed by the lower roller pair 67, the tip of the sheet P first passes through the pickup roller 69 as shown in FIG. Press against
The sheet P is nipped and conveyed by the pickup roller 69 and the driving roller 68.

At this time, the sheet P sent later
Enters the drive roller 68 side of the sheet P already stacked on the stopper 62, and is conveyed while sliding on the sheet already stacked on the stopper 62.

Here, if the pickup roller 69 is always kept in pressure contact with the drive roller 68, a conveying force is also applied to the sheet P which has already reached the stopper 62 and has been received. Buckling may occur. Therefore, by bringing the pickup rollers 69 into pressure contact only when necessary, the sheet alignment can be improved, and accurate loading on the vertical path 60 can be performed.

(Separation Operation of Pickup Roller 69) When the leading end of the sheet P approaches the stopper 62 by a predetermined distance, the pickup roller 69 is separated from the drive roller 68 as shown in FIG. Stopper 6
The predetermined distance from 2 is set to about 10 mm. After the pickup roller 69 is separated from the drive roller 68, the sheet P falls to the stopper 62 due to the inertia of its movement and its own weight.

The position of the leading end of the sheet P is recognized by the distance that the leading end of the sheet has conveyed after passing through the sheet sensor 66.

Here, if the pickup roller 69 is kept pressed against the drive roller 68 until the sheet P reaches the stopper 62, the sheet P may buckle,
When the pickup roller 69 is separated from the drive roller 68, rebound may occur and alignment may be disturbed. Therefore, by separating the pickup roller 69 from the drive roller 68 at an early stage, the sheet P is not excessively conveyed, and the above problem can be avoided.

(Operation of the Drive Roller 68 When the Pickup Roller 69 is Separated) As described above, if the pickup roller 69 is separated from the drive roller 68 before the sheet P is stacked on the stopper 62, the number of stacked sheets is still small. In this case, the sheet P may vigorously advance in the vertical path 60, rebound, and disturb the alignment. In addition, when the number of stacked sheets increases, the inside of the vertical path 60 becomes narrower, so that the friction required to pass the vertical path 60 increases.

Therefore, the drive roller 68 continues to rotate even after the pickup roller 69 is separated from the drive roller 68. At this time, since the sheet P being conveyed is not pressed against the drive roller 68, a weak conveying force is given only by the contact pressure. Thereby, the sheet P
Is securely transported to the stopper 62 and pressed against the stopper 62, so that it is securely aligned.

(Shape of the vertical path 60) The sheets P received and stacked by the stopper 62 are aligned in the width direction by the alignment member 71 (see FIGS. 6 and 8). At this time, since the sheet P is in an upright state, buckling may occur if the sheet P has no waist. Therefore, the path guide 60a is provided with a raised portion 60c that protrudes into the transport path of the vertical path 60, and the vertical path 60 is bent in the horizontal direction. As a result, the stacked sheets P also bend in the horizontal direction, that is, a vertical waist occurs in the sheets.

Accordingly, the sheets P are stacked on the stopper 62 without buckling.

On the other hand, if the sheet P remains bent in the horizontal direction, it is not preferable to perform the binding processing by the stapler unit 61. Therefore, as shown in FIG. 6, a vertical path 60 is provided between the upper and lower portions of the stapler unit 61.
, So that the sheet P is bent in the vertical direction at substantially the center.

That is, as shown in FIG. 7, the sheet P has a lower portion bent in the horizontal direction and a substantially central portion bent in the vertical direction to be stacked on the stopper 62. Thereby, the sheet P
Are stacked on the stopper 62 without buckling, and the position where the binding process is performed can be made flat.

(Mechanism of Stopper 62) A drive mechanism of the stopper 62 will be described with reference to FIG.

The stopper 62 is slidably supported along a stopper frame 72 via slide members 62a, 62a attached to both ends. Further, the stopper 62 has stopper driving belts 73, 73 stretched over a driving pulley 73a and an idler pulley 73b fixed thereto. The rotation shaft 73c of the drive pulley 73a is linked to a stopper drive motor 74 via a fixed drive gear 73d.

That is, when the stopper drive motor 74 rotates, the drive gear 73d, the rotating shaft 73c, the drive pulley 7
The stopper 62 can be driven in the vertical direction via the pulley 3a, the idler pulley 73b, and the stopper driving belt 73.

A stopper sensor 75 provided on the sheet stacking surface of the stopper 62 detects that the leading end of the sheet P has hit the stopper 62.
Further, a flag 62b is formed below the stopper 62, and when the stopper 62 is lowered, it is detected by the stopper home sensor 76 that the home position has been reached.

(Stapler Unit 61) Next, the mechanism of the stapler unit 61 as sheet binding means for binding the sheet bundle P will be described.

As shown in FIG. 9, the stapler unit 6
1 is a vertical path 6 by a support plate 77 fixed to a frame.
At the center position in the transport direction of the sheet bundle P aligned with 0, two sheets are arranged at symmetric positions with respect to the center in the sheet width direction.

In FIG. 9, the stapler unit 61
Is composed of an upper forming portion 61b, which is swingably supported about a rotation shaft 61a, as a needle driving means, a drive unit 61c, and an anvil 61d.

On the side of the stapler unit 61, a vertical path 60 for guiding the sheet bundle P by path guides 60a and 60b and an anvil 61d is formed. The vertical path 60 is formed such that the guide surface 60b1 of the path guide 60b for guiding the sheet bundle P and the binding surface 61d1 of the anvil 61d for binding the guided sheet bundle P have an angle α with each other. .

With the angle α, the vertical path 60
When the forming portion 61b of the stapler unit 61 swings, the upper side path guide 60a forming
A notch hole 60a1 of a size that does not interfere is formed.

A needle cartridge 61e is detachably mounted on the forming portion 61b, and about 2,000 to 5,000 binding needles 61f connected in a plate shape are loaded in the needle cartridge 61e.

The plate-like binding needle 61f loaded in the staple cartridge 61e is urged downward by a spring 61g provided on the uppermost side of the staple cartridge 61e.
It receives the conveying force of the needle feed roller 61h arranged at the lowermost side.

The binding staple 61f sent out by the staple feed roller 61h swings the forming portion 61b around the rotation shaft 61a in the direction of the arrow in FIG. Each is formed in a U-shape.

That is, when the stapler motor 61i is started, the eccentric cam gear 61k rotates via the gear train 61j, and the eccentric cam attached integrally with the eccentric cam gear 61k acts to form the forming portion 61b.
Swings in the direction of the arrow in FIG. 9 (toward the anvil 61d) to perform a staple driving operation (clinch operation), and folds the driven staples 61f by the anvil 61d (see FIG. 10) on the lower surface of the sheet bundle P. P is stapled.

A flag (not shown) is provided coaxially with the eccentric cam gear 61k. By detecting this flag with a stapler sensor (not shown), it is determined whether the stapler unit 61 is clinching or has ended clinching. Or before the clinch starts).

(Loading of staples) In the above-described binding process, if the staples are removed from the staple cartridge 61e as the staple loading section, it is necessary to replace the staples. Here, loading of the stapler into the stapler unit 61 will be described.

The stapler unit 61 is provided with two staple cartridges 61e for binding at two locations in the sheet width direction. When one of the staple cartridges 61e has no more staples, the staple cartridge 61e is staple. None is detected.

If the absence of the staple is detected, the stapler unit 61 is pulled out in the direction of the arrow, and the staple cartridge 61e is removed.
Is loaded with a new staple, but one staple cartridge 6
When only one needle cartridge 61e has no staple and the other staple cartridge 61e has staples remaining, the staples of the other staple cartridge 61e may be exhausted immediately after the staple cartridge 61e is loaded. Shut down the device,
It is inefficient to pull out the stapler unit 61 and load the needle.

When the absence of the staple is detected, the stapler unit 61 is pulled out, the staple is loaded into one staple cartridge 61e having no staple, and the staple remains in the other staple cartridge 61e. The remaining needles are replaced with new binding needles even when the needles are set, and a message prompting the user to simultaneously load the two needle cartridges 61e is displayed on an operation panel as a display unit.

According to this display, by simultaneously loading the needles into the two needle cartridges 61e, the two needle cartridges 61e are in a needleless state at the same time.

Even if the needles do not run out at the same time, when one of the needle cartridges 61e runs out of needles, the number of needles remaining in the other needle cartridge 61e becomes small.

Then, by simultaneously loading them, each needle cartridge 61e is
Loading can be performed more efficiently than when needle loading is performed.

Although two staple cartridges 61e are provided, the stapler unit 61 provided with three or more staple cartridges 61e is also required to simultaneously replace the staples of all the staple cartridges.

After the needle is loaded as described above, the stapler motor 61i (see FIG. 9) is driven to perform the cueing of the needle. It is necessary to detect whether or not the cueing of the needle has been performed. This cueing can be detected by a sensor or the like, but detection of cueing of the needle is performed by detecting a drive current value of the stapler motor 61i. This cueing detection may be performed by a sensor or the like.

That is, when the stapler motor 61i is driven to perform the cueing, before the cueing of the needle (idling state), the load applied to the stapler motor 61i is small. The driving current becomes smaller. On the other hand, when the cue of the needle is performed (staple driving state), the load applied to the stapler motor 61i increases, and the current for driving the stapler motor 61i becomes larger than in the idle driving state. Accordingly, a current value for driving the stapler motor 61i is detected, and if this current value is smaller than a predetermined value, it is detected that the cue has not yet been performed, and if the current value is larger than the predetermined value, it is detected that the cue has been performed. is there.

As described above, by detecting the cueing of the needle based on the drive current of the stapler motor 61i, it is not necessary to provide a special sensor for cueing, and the number of parts can be reduced and the cost can be reduced.

(Post-Stapling Process) After the stapler unit 61 is driven to bind the sheet bundle P conveyed and aligned to the vertical path 60 as described above at the center in the sheet conveying direction, the stopper 62 is moved downward. Then, the sheet bundle P is transported to the folding position. At this time, as shown in FIG. 10, the stapling staple 61f is inserted into the groove 61d2 of the anvil 61d.
When the stopper 62 is moved downward, the binding needle 61f may be caught in the groove 61d2, and the sheet bundle P may be transported poorly.

Therefore, as shown in FIG. 10, the pickup roller 69 of the lower roller pair 67 is swung once in the direction of the arrow in FIG. 10 before the sheet bundle P after stapling is conveyed downward. It has become.

As a result, the sheet bundle P is pressed toward the path guide 60a by the pickup roller 69, so that the binding needle 61f fitted in the groove 61d2 of the anvil 61d surely comes out of the groove 61d2. Therefore, the stopper 62 does not move downward in a state where the binding needle 61f is fitted in the groove 61d2, and it is possible to reliably prevent sheet conveyance failure.

Here, in the above embodiment, an example was shown in which the sheet bundle P was displaced by swinging the pickup roller 69 so that the binding needles 61f came out of the grooves 61d2. Instead, a configuration may be adopted in which a dedicated member is provided as a displacement unit for displacing the sheet so that the binding needle 61f comes out of the groove 61d2, and this member is operated to perform the operation.

When the sheet bundle P is conveyed downward by lowering the stopper 62, the pickup roller 69 is separated from the driving roller 68, and the driving roller 68 is driven to rotate in the direction of lowering the sheet P. It is made to let.

As a result, when the sheet bundle P falls due to its own weight, even if the sheet bundle P is in contact with the drive roller 68 formed of a material having a high friction coefficient, there is little occurrence of a frictional load when descending. Therefore, the descending sheet bundle P can reliably follow the stopper 62, and the accuracy of the folding position is guaranteed.

(Fine adjustment of binding position and folding position)
In order to accurately bind the center (center) in the transport direction of the sheet bundle P and perform the folding process described later, the sheet bundle P
It is necessary to move the stopper 62 so that the center of the sheet is accurately located at the binding position and the folding position.

However, the length of the sheet is not constant due to an error at the time of cutting, expansion and contraction due to humidity, and the like. Therefore, the binding position and the folding position may not be at the center of the sheet bundle P. In that case, it is necessary to finely adjust the position of the stopper 62 for supporting the lower end of the sheet.

Conventionally, the stopper 61 is screwed into a long hole formed in the frame supporting the stopper 61,
Fine adjustment is possible within the range of the long holes, and the sheet bundle P
The binding position and the folding position are finely adjusted.

However, in order to perform the fine adjustment as described above, it is necessary to loosen the screw, tighten the screw after the fine adjustment, and it takes time and effort to perform the adjustment operation, and it is difficult to accurately perform the fine adjustment. . In addition, this adjustment work can only be performed by a service person.

Then, the movement amount of the stopper 62 by the above-described drive mechanism (see FIG. 8) can be finely adjusted by a user's instruction from an input means such as an operation panel provided in the copying machine main body A or the sheet processing apparatus B. Like that.

Specifically, before the stapling, the stopper 62
The movement amount (elevation amount) when moving from the home position to the lower end stop position (binding stop position), which is the stop position of the binding process according to the sheet size, is determined by an operation panel (not shown) provided on the copying machine main body A. The fine adjustment is performed automatically.

For example, the amount of movement from the home position to the lower end position of each size sheet is usually constant for each sheet size, but this amount of movement is an amount corresponding to an instruction from the operation panel as input means. The amount of movement of the stopper 62 when it is raised is finely adjusted, and the stop position is changed by the fine adjustment.

Alternatively, the amount of movement (the amount of descent) when the stopper 62 moves from the lower end stop position (binding stop position) according to the sheet size to the lower end stop position (folding stop position) during folding processing after stapling is determined by A fine adjustment can be made by operating a dip switch (not shown) of the electrical board provided in the processing apparatus B or from an operation panel.

The movement amount of the stopper 62 from the lower end stop position during the binding process to the lower end stop position during the folding process is constant regardless of the sheet size (about 70 mm in the present embodiment).
It is. The amount of movement is adjusted by an amount corresponding to the operation of the dip switch of the electrical board, and the amount of movement of the stopper 62 when it is lowered is finely adjusted, and the stop position is changed by the amount of fine adjustment.

With this configuration, fine adjustment of the stopper 62 that receives the lower end of the sheet can be performed accurately and easily.

Further, the sheet may be elongated in the course of conveyance due to roller pressure, temperature, humidity, etc., though the length is very small. Therefore, the length of the sheet may be detected by the sheet length detecting means during sheet conveyance, and the stop position of the stopper 62 may be configured to be able to be automatically adjusted according to the detection result.

For example, when a sheet is conveyed to the vertical path 60, the upper sensors 66a to 66a-6
6c detects this, but when this sensor detects the leading edge of the sheet, the pulse counter (not shown) of the conveyance motor is turned on, and the trailing edge of the sheet passes through the sensor position. The number of pulses until this sensor is turned off is counted. Thus, the length of the sheet sent to the vertical path 60 can be accurately detected. And the conveyed sheet (slightly elongated sheet)
The amount of movement of the stopper 62 from the home position to the binding stop position and the amount of movement from the binding stop position to the folding stop position of the stopper 62 are automatically calculated and fine-tuned by the control means in accordance with the length of the stopper 62. The stopper 62 is moved according to.

If the amount of movement of the stopper is automatically and finely adjusted according to the sheet length detected during conveyance as described above, the user does not need to make fine adjustment settings, and the sheet can be more accurately and easily adjusted. It can be stopped at the binding position and the folding position.

(Folding of Sheet Bundle P) As described above, the binding position of the sheet bundle P is moved by the downward movement of the stopper 62 to the position of the folding roller pair 178 (see FIG. 11) disposed below the stapler unit 61. When the sheet bundle P is moved to the binding position by the pushing plate 79a (see FIG. 12), the sheet bundle P is nip-conveyed in a state of being folded in two by the folding roller pair 178, and is folded in two.

Next, the folding structure of the sheet bundle P will be described with reference to FIGS.

As shown in FIG. 11, a folding roller pair 178 is provided.
Is a fixed roller 178a rotatable about an immovable rotation shaft 178c, and a fulcrum 80 on a frame of the sheet processing apparatus B.
and a movable roller 178b rotatably attached to a support arm 80 that is rotatable about a.

The movable roller 178b is fixed to the fixed roller 178a by a spring 81 locked at one end of the support arm 80.
Is pressed against.

With this configuration, the pitch between the pair of folding rollers 178 is corrected according to the thickness of the sheet bundle P to be nipped.

A structure for driving the pair of folding rollers 178 will be described with reference to FIGS.

The motor pulley 83 is fixed on the output shaft 82a of the folding motor 82. This motor pulley 83
Is transmitted to the pulley portion of the idler gear pulley 85 via the timing belt 84.

Incidentally, on the idler gear pulley 85 shaft,
The pulley portion and the gear portion are provided.

A folding gear 86 is fixed to the shaft of the pair of folding rollers 178 described above. A gear 87 meshes with the folding gear 86. The folding gear 86 meshes with a gear portion of the idler gear pulley 85.

A flag 230 is provided on the gear 86 of the fixed roller 178a, and a D home sensor 229 is disposed at a position where the D portion of the pair of folding rollers 178 is detected. The D home sensor 229 includes a folding roller pair 178.
The nip is released so that the sheet bundle P can be detected at a position where a space through which the sheet bundle P can freely pass is provided.

The rotational force of the folding motor 82 is transmitted from the motor pulley 83 to the idler gear pulley 85 via the timing belt 84. And the idler gear pulley 8
5 is transmitted from the folding gear 86 to the folding gear 87,
The folding roller pair 178 is driven.

The standby position of the folding roller pair 178 is a position where the D portion of the pair of fixed roller 178a and the movable roller 178b is opposed. Before the sheet bundle P reaches the folding roller pair 178 by the protruding unit 79, the folding motor 82 drives the folding roller pair 178 at the timing of pressing, and after one rotation, stops.

In FIG. 12, a projecting unit 79 as projecting means includes a projecting plate 79a, a holder 79b,
79d, shafts 79c and 79e, and the like. The pushing plate 79a is held by holders 79b and 79d. Shafts 79c and 79e are fixed to the holder 79b. “Rollers” (not shown) are rotatably attached to the outer circumferences of the shafts 79c and 79e. The "rollers" slide in grooves 89 formed in the body frame.

A motor pulley 90a is fixed on the output shaft of the protruding motor 90. The idler gear pulley 91 has a pulley portion and a gear portion formed coaxially. A timing belt 92 is wound between the pulley portion of the idler gear pulley 91 and the motor pulley 90a. The gear portion of the idler gear pulley 91 meshes with a gear 94 having a shaft 93 in part.

As shown in FIG. 13, the rotating shaft 9 of the gear 94
Flags 95a and 95b are fixed on 4a.
These flags 95a and 95b have notches partially. A protruding home sensor 96a and a protruding position sensor 96b are provided at positions where the notches of the flags 95a and 95b are detected. This protruding home sensor 9
Reference numeral 6a denotes a position where the pushing plate 79a is drawn from the sheet conveying surface formed by the path guides 60a and 60b, and is arranged so as to detect the notch of the flag 95a. The thrust position sensor 96b is provided so as to detect the notch of the flag 95b at the position where the thrust plate 79a has thrust.

Further, as shown in FIG.
, A rotating plate 97 having a shaft 97a is fixed thereto. The rotating plate 97 rotates in synchronization with the gear 94.

The rotational force of the protruding motor 90 is transmitted from the motor pulley 90a to the idler gear pulley 91 via the timing belt 92. As the idler gear pulley 91 rotates, the gear 94 rotates, and the shaft 9 rotates.
3 makes a circular motion. One end of a link 98 is rotatably fitted to the shaft 93, and the other end of the link 98 is rotatably fitted to a shaft 79 c of the protruding unit 79.

Similarly, one end of a link 98 is rotatably fitted to a shaft 97a on the rotating plate 97, and the link 98
Is fitted on the shaft 79c of the protruding unit 79. As a result, the circular motion of the shaft 93 is transmitted to the shaft 79c of the projecting unit 79 via the link 98, and the shaft 79c moves along with the shaft 79c along the groove 89 of the frame fitted via rollers (not shown). Perform a linear motion.

Similarly, the other end of the projecting unit is also
The rotational movement of the rotation plate 97 and the shaft 97 a on the rotation plate 97 is converted into a linear movement of the protruding unit 79 via the link 98.

In this manner, the projecting unit 79
Receives the driving force at both ends, and always slides parallel to the folding roller pair 178 in the direction of the arrow in FIG.

As shown in FIGS. 13, 14 and 15, stopper shafts 97b and 97c are provided on the surface of the rotating plate 97 opposite to the shaft 97a. A stopper member 99 is provided on the main body frame so as to be swingable about a shaft 99a. The stopper member 99 is pulled by the tension spring 100 toward the rotation shaft 94a.

As described above, the rotation of the rotation plate 97 causes the protrusion unit 79 to slide, but the rotation plate 97 rotates in the direction of the arrow in FIG. When the stopper shaft 99c and the stopper member 99 are fitted when reaching the position (the leftmost position in FIG. 12) detected by the protrusion position sensor 96b,
The rotating plate 97 does not rotate any more. For this reason, the projecting unit 79 moves
Fixed.

When returning the ejecting unit 79 to the home position, the ejecting motor 90 is rotated in the direction opposite to the direction in which the ejecting unit 79 is ejected, and the engagement between the stopper member 99 and the stopper shaft 97c is released. Then, the projecting unit 79 returns to the home position, and at the position detected by the home sensor 96a (the rightmost position in FIG. 13), the stopper shaft 97b and the stopper member 99 are fitted and rotated as shown in FIG. The plate 97 does not rotate any more.

Therefore, the projecting unit 79 moves in the left-right direction in FIGS. 12 and 13 by the forward / reverse rotation of the projecting motor 90.

(Distance between Nip of Fold Roller 178 and Centering of Push Plate 79a) As shown in FIG. 11, the movable roller 178b of the fold roller 178 is moved from the fixed roller 178a in accordance with the thickness of the sheet bundle P. Move away. That is, the distance between the nips of the pair of folding rollers 178 is variable.

On the other hand, if the pushing position of the pushing plate 79a is always constant, the pushing plate 79a does not necessarily strike the center between the nips of the pair of folding rollers 178, and the sheet bundle P may not be folded at the binding position. is there.

Therefore, the pushing plate 79a always projects at the center between the nips even if the distance between the nips of the pair of folding rollers 178 changes due to the cam member. The configuration will be specifically described with reference to FIG.

As shown in FIG. 16, the projecting unit 7
Reference numeral 9 indicates that the sliding roller 79g is rotatable about a fulcrum (the outer diameter of the sliding roller 79f is set smaller than the width of the groove 89). Double shaft 178 of folding roller pair 178
The cam member 101 is attached to c and 178d. The cam member 101 has a cam groove 101a that can be engaged with the movable roller shaft 178d, and a guide portion 101b of the protruding unit 79. Projection unit 79
Is urged downward by a spring 102 to
It slides with respect to b.

The cam member 101 is rotatably mounted around a shaft 178c of a fixed roller 178a, and the movable roller 178b is rotated about a fulcrum 80a (see FIG. 11) to move the movable roller 178b to the fixed roller. 178
When it moves in the direction away from a, the shaft 178d of the movable roller 178b pushes up the cam groove 101a. As a result, the cam member 101 rotates in the counterclockwise direction in FIG. 16, and the guide portion 101b lifts the protruding unit 79 as shown in FIG. The cam groove 101a and the guide portion 101b are formed in such a shape that the pushing plate 79a always projects at the center of the distance between the nips of the pair of folding rollers 178.

By providing the cam member 101 as described above, the folding roller pair 1
Even if the distance between the nips 78 changes, the thrust position of the thrust plate 79a is aligned, and the thrust plate 79a always strikes the center of the distance between the nips so that the sheet bundle P is reliably folded at the binding position. Has become. Further, since the centering of the pushing plate 79a can be performed only by attaching the cam member 101 as described above, the structure does not become complicated.

The sheet bundle P is bent by pushing the pushing plate 79a to nip the folding roller pair 178. Even after the folding roller pair 178 nips the sheet bundle P, the pushing plate 79a pushes the pushing unit 79. If it is in the position, the inner sheet may be wrinkled due to the frictional force between the folded sheet and the pushing plate 79a.

Therefore, in the present embodiment, as shown in FIG. 18, after the sheet bundle P is nipped by the pair of folding rollers 178, the pushing plate 79a is returned to the home position. If the timing of pulling back the pushing plate 79a is too early, the folding roller pair 178 may cause the sheet bundle P
Before the nip, the pushing plate 79a returns. For this reason, in this embodiment, in order to fold the sheet bundle P, the folding roller pair 178 pulls back the pushing plate 79a at the time when the folding roller pair 178 rotates a predetermined amount.

As a result, the sheet bundle P is moved to the folding roller pair 1
At the time when the sheet is conveyed to the nip, the pushing plate 79a is retracted to the home position, so that the folded sheet bundle P does not rub against the pushing plate 79a, thereby preventing wrinkles from being generated.

(Folding Operation) As described above, the folding roller pair 178 conveys the center of the sheet bundle P on which the binding process has been performed while nipping the center portion of the sheet bundle P struck by the pushing plate 79a. Folds the sheet bundle P.

Fixed roller 178a of folding roller pair 178
A nip releasing portion 178h which is a relief portion is formed on the outer periphery of the movable roller 178b and a part in a direction parallel to the axis of the roller and in a rotating direction. Nip release unit 17
8h is formed at a portion facing the binding needle in the rotation direction of the rollers 178a and 178b so that a part of the folding roller pair 178 does not pinch the binding needle.

The remaining portion left by the nip releasing portion h is
178 g of the entire press-contact portions press against each other. The entire pressure contact portion 178g includes an axial pressure contact portion 178g1 which is a remaining portion in the axial direction parallel to the axis of the roller, and a rotation direction pressure contact portion 178g2 which is a remaining portion in the rotational direction of the roller. The rotation direction pressure contact portion 178g2 is located between the two binding needles so as not to pinch the two binding needles. Note that the axial pressing portions 178g1 sandwich the binding needle.

At the time of folding the sheet bundle P, the folding roller pair 178 firstly contacts the axial pressing portions 178g1 of the entire pressing portion 178g which can be pressed in the entire longitudinal direction of the roller, as shown in FIGS. Waiting in pressure.

At the start of the folding operation, the folding roller pair 178
Rotates, as shown in FIG. 21, before the sheet bundle P protruded by the protruding plate 79a reaches the folding position, presses against the axial press contact portions 178g1 of the entire press contact portion 178g,
The sheet bundle P is folded.

As shown in FIG. 22, the folding roller pair 178 nips and conveys the sheet bundle P as it is, and discharges and stacks the sheet bundle on a tray by a conveying roller (not shown).

Although a conveyance roller for the sheet bundle is provided downstream of the folding roller pair 178, this may be omitted, and the sheet bundle may be conveyed to the tray by the folding roller pair 178 and stacked. .

After the sheet bundle is conveyed, the D home sensor 22
9 (see FIG. 13), the folding roller pair 178 stops at the position shown in FIG.
The entire press-contact portion 178g is brought into a standby state in a press-contact state.
(At this time, the roller is in pressure contact with the entire area in the longitudinal direction of the roller.) If the nip releasing portion 178h, which is a relief portion, is not formed in the folding roller pair 178, there is no dent in the entire roller, and the sheet bundle Since the sheet P is always pressed and conveyed, distortion is accumulated on the front side of the sheet bundle P, and wrinkles are easily generated.

Therefore, the sheet folding apparatus F of the present embodiment is used.
Before the sheet bundle P reaches the folding roller pair 178,
The axial pressing portions 178g1 of the entire pressing portion 178g of the folding roller pair 178 are pressed against each other to nip and fold the sheet bundle, and the nip releasing portion 178h is detected by the D home sensor 229 and the roller central portion ( Release the pressure in places other than the rotation direction pressure contact portion 178g2) and reduce the pressure applied to the sheet bundle to the central portion (rotation direction pressure contact portion 178g2).
Only by doing so, the sheet deflection is released.

As a result, distortion in the sheet bundle can be prevented, and wrinkles can be suppressed.

For example, as shown in the flowchart of FIG. 23, the sheet bundle conveyed to the folding position moves the pushing plate 79a by starting the pushing motor 90 (S
1) After the specified clock has elapsed (S2), the folding motor 82 is started (S3). This time is protruding unit 7
9 is set so that the sheet bundle P comes into pressure contact with the entire pressure contact portion 178g of the pair of folding rollers 178 before reaching the folding position.

After the sheet bundle P is folded in two by the folding roller pair 178, the folding roller pair 178 always rotates, and after discharging the sheet bundle, the D home sensor 229 detects the nip release portion 178h of the folding roller pair 178. The position is detected (S
4) After reaching the specified clock (S5), the motor is stopped (S6).

On each sheet of the sheet bundle, an image is formed (recorded) on the upstream half surface and the downstream half surface in the transport direction with reference to the center of the sheet. Similarly, the image formation as described above is performed on both sides of the sheet. In addition, this image formation is performed such that the sheet bundle subjected to the binding and folding processing is arranged in page order.

As described above, the sheet bundle is folded into the pair of folding rollers 1.
When an image is formed in the center of the sheet bundle when the sheet is pulled in at 78, the image (toner) lowers the sheet friction coefficient. Wrinkles and tears may occur.

Here, the mechanism of sheet tearing and wrinkling during folding processing will be briefly described with reference to FIG. Here, two sheets P11, P1
The following describes an example of a sheet bundle composed of two sheets.

The folding roller pair 178 and the first sheet P1
Assuming that the frictional force between the first sheet P1 and F1 is F1, the frictional force between the first sheet P11 and the second sheet P12 is F2, and the binding force of the binding needles that bind the sheet bundle is F3, F1 =
When the relational expression of F2 + F3 holds, a normal folding process is performed.

However, when the frictional force F2 between the sheets P11 and P12 decreases, the binding force F3 of the binding staple needs to be larger in order to satisfy the above expression. At this time, even if the strength of the sheet can withstand the binding force F3 of the binding staple, the second sheet P12 is pulled by the binding staple, and a deviation occurs between the sheets as shown in FIG. Further, bending occurs as shown in FIG.

When the sheet passes through the pair of folding rollers 178 in this state, wrinkles are generated as shown in FIG.

Further, when the strength of the sheet cannot withstand the binding force F3 of the binding needle, the sheet is torn as shown in FIG.

Therefore, the folding roller pair 178 of this embodiment is used.
As described above, a portion for releasing the pressure applied to the sheet bundle other than the central portion of the sheet bundle during conveyance of the sheet bundle (nip release portion 178)
When h) is provided, as shown in FIG. 25B, even when the bending occurs, the sheet bundle is nipped only at the central portion (rotational pressure contact portion 178g2), and the bending is caused by the folding roller pair 178. The sheet P12 can move freely without being constrained by this, and the deflection during the sheet bundle conveyance is eliminated.

In this state, even if the sheet bundle is nipped again at the entire pressure contact portion 178g, there is no wrinkle because there is no distortion in the sheet bundle.

A sheet P (sheet bundle) to be a folding portion
Is provided with a constant margin portion (folding allowance t). Specifically, the image formation on the sheet P to be processed by the stitcher unit D is performed in advance at the time of image formation in the copying machine main body A by using a folding allowance t (t = about 5 mm to about 8 mm in this embodiment) of the sheet center portion. And the width of the blank portion is set to be about 10 mm to about 16 mm).

In the figure, reference symbol Ps indicates the center (center in the transport direction) of the sheet P, and reference symbol Pg indicates the sheet P
2 shows an image forming portion.

As described above, when the folding allowance t is provided on the sheet, when the sheet bundle is pulled in by the folding roller pair 178, a margin portion (folding allowance t) previously provided on the sheet P is provided.
As a result, the frictional force between the sheet P and the pair of folding rollers 178 increases, and the sheet bundle P is reliably drawn into the pair of folding rollers 178 without causing the above-described wrinkles and tears.

If the width of the margin is smaller than about 10 mm, a sufficient frictional force cannot be obtained when the sheet bundle is pulled in. When the margin width exceeds about 16 mm, the image forming area decreases. Therefore, the margin width is about 10 mm
It is preferably set to about 16 mm.

The sheet folding apparatus F is set to form an image by providing a margin portion of a predetermined width for the sheet to be folded. However, when it is necessary to increase the image forming area, the sheet The setting of the unit may be canceled.
In particular, when the number of folds is small, there is a small possibility that tearing will occur even if the margin of the fold is narrowed. Therefore, the setting of providing a margin having a predetermined width is canceled, and a normal margin width (for example, about 4 mm) is used. To form an image. This makes it possible to increase the image forming area.

When the sheet bundle to be bound and folded as described above has a cover sheet (in the cover mode), the cover sheet (hereinafter referred to as “cover sheet”) is used.
When image formation is also performed on the back surface of the cover sheet, when the toner image transferred to the back surface of the cover sheet is fixed by the fixing unit, silicon oil or the like adheres to the back side of the cover sheet, Has a reduced coefficient of friction. In addition, high quality paper (and thick paper) is often used for the cover sheet,
When silicone oil adheres to this high quality paper, the friction coefficient is further reduced as compared with other sheets (plain paper).

When this cover sheet is sandwiched by a pair of folding rollers to be bent and pulled in, slippage occurs between the sheets because the coefficient of friction between the back sheet and the sheet in contact with the back sheet is small. There is a risk of being pulled in.

Therefore, in the cover mode, no image is formed on the back surface of the cover sheet. Specifically, at the time of image formation in the copying machine main body A, after forming an image on the surface of the cover sheet, the cover sheet is discharged as it is without passing through the re-sending path 7 (see FIG. 1), and the stitcher unit D I send it to.

The cover sheet (such as high quality paper) is supplied from the multi tray 8 (see FIG. 1).
When the last sheet sent to the stitcher unit D is supplied from the multi-tray 8, the sheet can be discharged without passing through the retransmission path 7.

As described above, since the back side of the cover sheet does not come into contact with the fixing means (fixing roller on the image side), silicone oil does not adhere to the back side of the cover sheet, and the friction coefficient decreases. Is prevented, and only the cover sheet is prevented from being pulled in by the folding roller pair 178.

(Sheet Bundle Detecting) If a break occurs in the sheet bundle during normal folding processing, a configuration is conceivable in which such a break is detected by detecting means such as a sensor, but such a break is detected. If the detecting means is separately provided, the number of parts increases and the cost increases. Further, at the time when the tear is detected, the next sheet may have been conveyed, and since the previous sheet is staying, there is a possibility that a more severe jam may occur.

In order to prevent the occurrence of a jam due to the breakage of the sheet bundle, the sheet folding apparatus F includes an intermediate sensor 103 provided near the folding roller pair 178 (upstream side), as shown in FIG. When each sensor detects the presence of a sheet at the same time using the stopper sensor 75 provided on the stopper 62 and the discharge sensor 105 provided near the discharge roller 104, the sheet (or sheet bundle) is torn, and The sheet unit (or sheet bundle) is detected by the tea unit D to be staying.

Note that the sheet folding apparatus F includes an intermediate sensor 103, a stopper sensor 75, and a discharge sensor 105.
Detects the occurrence of a sheet tear at the same time when the presence of a sheet is detected. However, the present invention is not limited to this. For example, when both the stopper sensor 75 and the discharge sensor 105 detect the presence of the sheet, the sheet tear is detected. May be detected.

With this configuration, it is not necessary to separately provide a detecting means for detecting that the sheet (or sheet bundle) has been torn, thereby preventing an increase in the number of parts and an increase in cost. it can. Further, since the tearing of the sheet can be detected early at the folding timing of the sheet, the conveyance of the next sheet can be stopped early to prevent the sheet from jamming.

(Discharge Operation) The sheet bundle subjected to the folding process is discharged onto the stacking tray 106 by the discharge rollers 104 and stacked. As shown in FIG. 29, a sheet bundle holding member 107 for holding the sheet bundle P is provided on the upper portion of the discharge roller 104 so as to be rotatable around the rotation shaft 107a. The holding member 107 presses the end of the folded sheet bundle P when the folded sheet bundle P is discharged from the discharge port onto the stacking tray 106 by the discharge roller 104. As a result, even if the sheet bundle P is insufficiently folded, the sheet bundle P can be stacked so as not to open on the stacking tray 106.

The pressing member 107 is regulated so that the rotating roller 107b provided at the tip thereof does not become lower than a predetermined height h (height not in contact with the stacking tray 106). Can move freely in the direction of lifting. For this reason, the ejection failure of the sheet bundle P caused by the front end portion of the weak sheet bundle P being pressed by the pressing member 107 is eliminated.
The sheet bundle P is reliably stacked on the stacking tray 106.

When the discharge roller 104 discharges the folded sheet bundle P onto the stacking tray 106 in this manner, the sheet bundle folding side (downstream in the discharge direction) expands as compared with the sheet bundle open side. If the sheet bundle P is stacked as it is, only the folding side of the sheet bundle becomes high, and there is a possibility that the stacking property becomes unstable.

Thus, as shown in FIG. 28, the sheet bundle P discharged by the discharge roller 505 is
An apparatus is conceivable in which the sheet bundle P is sequentially shifted so as to be stacked like a roof tile that forms a roof on the stack 4 and discharged and stacked.

However, in the above configuration, when a large number of sheet bundles are to be discharged, the stacking tray needs to be enlarged.
There is a problem that the device becomes larger and the installation space becomes larger.

Therefore, as shown in FIG. 29, the portion of the stacking tray 106 near the discharge roller 104 of the stacking tray 106 is made higher than the stacking surface 106b (projection 106a).
The folding side of the sheet bundle P rests on the stacking surface 106b on the leading end side (downstream in the discharge direction) of the stacking tray 106, and the open side rests on the protrusion 106a. As a result, the folded side is lower than the open side, and even when the folded side is larger than the open side, the difference in height from the open side can be reduced to facilitate stacking of the sheet bundle P.

Specifically, when the sheet bundle P is thick (that is, when the folding side is a particularly swelling sheet bundle), the speed of discharging the sheet bundle by the discharge roller 104 is reduced, and the open side of the sheet bundle P becomes the protrusion 106a. It is discharged so that it is put on. When the sheet bundle P is thin (that is, in the case of a sheet bundle whose fold side does not expand relatively), the sheet bundle discharging speed by the discharge roller 104 is increased, and the open side of the sheet bundle P does not rest on the protrusion 106a. Thus, the paper is discharged onto the loading surface 106b.

As a result, the sheet bundle P discharged onto the stacking tray 106 does not rise on only one side (folding side), and the stackability of the sheet bundle P is stabilized. Also,
Since the sheet bundle P does not have to be stacked like a roof tile, it is not necessary to enlarge the stacking tray 106.

The stacking tray 106 is
a, but the present invention is not limited to this. That is, the loading tray 106 may be provided with an inclined portion, or the loading tray 106 itself may be inclined, or a projection that can be inserted into or removed from the bottom surface of the loading tray 106 may be provided on the loading tray 106. .

(Explanation of Control System) Here, based on FIG. 30, the configuration of the main part of the control system for controlling the drive of each member of the stitcher unit D will be described.

In FIG. 30, MPU as a control means
200 is a first upper sensor 66 for detecting the presence or absence or the leading end or the trailing end of the sheet conveyed to the stitcher unit D.
a to third upper sensors 66c, an alignment member home sensor 220 for detecting the home position of the alignment member 71, a stopper home sensor 76 for detecting the home position of the stopper 62, a stopper sensor 75 provided for the stopper 62 to detect a sheet, Signals are received from sensors such as a discharge sensor 105 provided near the discharge roller 104, a protruding position sensor 96b for detecting the protruding position of the protruding plate 79a, and an intermediate sensor 103 provided near the folding roller pair 178. ing.

The MPU 200 drives the first flapper 21 for feeding the sheet to the vertical path of the stitcher unit D via the drivers D20 to D28 based on the signals from the sensors and the signal from the copier body A. Flapper solenoid 201 for switching, first solenoid 221 for switching first flapper 64a and second flapper 64b on the vertical path, and second solenoid 22 for switching
2. A conveying motor 223 for driving the upper roller pair 63 and the lower roller pair 67 to convey the sheet, a stapler motor 61i for driving the stapler unit 61, a width adjusting motor 224 for operating the alignment member 71, and a stopper 62. , A folding motor 82 for driving the folding roller pair 178, a protruding motor 90 for driving the protruding plate 79a, and the like, so that the above-described operation is performed. ing.

(Other Embodiments) In the above-described stitcher unit D, a sheet bundle conveying roller is disposed downstream of the pair of folding rollers 178, but this is omitted, and as shown in FIG. With the pair 178, the sheet bundle can be transported to the tray 106 and stacked.

Also, the folding roller pair 178 shown in FIG.
Is a portion that always applies a conveying force to the sheet bundle (the entire pressing portion 1
A rotation pressure contact portion 178g2) of 78 g is formed at one center, but like the fixed roller 278a and the movable roller 278b of the folding roller pair 278 shown in FIG.
The rotation direction pressure contact portions 278g2 of the entire pressure contact portion 278g may be formed at two places near the outside and near the two binding needles, or at two places inside the two binding needles.

Thus, after the folded end portion of the sheet bundle is sandwiched between the axial pressing portions 178g1 of the entire pressing portion 178g, the bending accumulated outside the binding needle is released by the nip releasing portion 278h. Wrinkles generated in the bundle can be reduced.

The folding roller pair 278 shown in FIG.
Has two rotation-direction press contact portions 278g2,
In a sheet bundle bound by one binding needle, the binding needle can be positioned between the two rotation-direction pressing portions 278g2 to bend the sheet bundle.

As in the case of a pair of folding rollers 378 shown in FIG. 33, the pair of folding rollers 378 always forms a nip at one location near the center of the sheet bundle and at two locations not in contact with the sheet bundle. , Fixed roller 378a and movable roller 378b, axial pressing portion 37 of total pressing portion 378g.
When 8 g 1, three rotation direction pressure contact portions 378 g 2, and two nip release portions 378 h are formed, one rotation direction pressure contact portion 378 g 2 at the center applies a conveying force to the sheet bundle P, and the two nip release portions 378 h Thus, the bending of the sheet bundle P is released, wrinkles are prevented from occurring, and the fixed roller 378a and the movable roller 378b can be brought into parallel contact with each other at the two outer rotational contact portions 378g2.

The pair of folding rollers 178, 278, and 378 described above are rubber rollers or resin rollers having elasticity.

A pair of folding rollers 178, 27
8,378 are nip release parts 178h, 278h, 37
8h, fixed rollers 178a, 278a, 378a,
Although it is formed on both the movable rollers 178b, 278b, and 378b, the same object can be achieved even if it is formed on any one of them.

In the folding roller pairs 178 and 378 shown in FIGS. 19 and 33, the nip releasing portions 178h and 178h are provided.
378h may be formed on the fixed rollers 178a, 378a and the movable rollers 178b, 378b, one by one so as not to face each other. In the folding roller pair 278 shown in FIG. 32, the nip releasing portion 278h may be formed at two places at one of the fixed roller 178a and the movable roller 178b and at one place at the other so as not to face each other.

In any case, fixed rollers 178a, 178
78a, 378a, and movable rollers 178b, 278b,
It is sufficient that a nip releasing portion that does not pinch the sheet is formed on the surface that is in pressure contact with the 378b.

Further, the above-described sheet folding apparatus is designed to bend a sheet bundle bound by a binding staple, but when a sheet bundle not bound by a binding staple is folded, wrinkles may be generated by the nip releasing portion. Can be prevented.

[0198]

According to the sheet folding apparatus of the present invention, a relief portion is formed on the outer circumference of a pair of rotating members, and the entire folded portion of the sheet bundle is pressed against the remaining portions in the axial direction to bend the sheet bundle. After that, the sheet bundle bent between the remaining portions in the rotation direction is nipped and conveyed, and while the sheet bundle is being rotationally conveyed,
Since the pressure applied to the sheet bundle can be released by the relief portion, the pushing operation of the sheet bundle by the ejecting means and the distortion in the sheet bundle generated during the conveyance operation are released, and the wrinkles of the sheet bundle are released. This can reduce the occurrence of the sheet bundle and smoothly perform the bending and conveying of the sheet bundle.

Further, when the occurrence of wrinkles is reduced, the rotating body is not over-concentrated, and damage to the rotating body can be prevented.

Furthermore, the guide required to cover the rotator, which is conventionally required, can be omitted, and the structure can be simplified.

Further, since the wrinkles that occur in the sheet bundle are small even when the pair of rotating members are continuously rotated without stopping the rotation of the pair of rotating members once during the sheet folding conveyance, the folding efficiency of the sheet bundle can be improved. it can.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view of a copying machine which is an image forming apparatus provided with a sheet folding apparatus according to an embodiment of the present invention.

FIG. 2 is a front sectional view of the finisher unit.

FIG. 3 is a front sectional view of a main part of the stitcher unit.

FIG. 4 is a diagram for explaining the operation of a pickup roller.
FIG. 6A is a diagram illustrating a state in which pickup rollers are in contact with each other. (B) It is a figure in the state where pickup rollers were separated from each other.

FIG. 5 is a diagram for explaining the operation of a pickup roller.
FIG. 6A is a diagram illustrating a state in which pickup rollers are in contact with each other. (B) It is a figure in the state where pickup rollers were separated from each other.

FIG. 6 is a front view for explaining the shape of a vertical path.

FIG. 7 is a diagram illustrating the shape of a sheet leaning on a vertical path.

FIG. 8 is a front view of a stopper driving mechanism.

FIG. 9 is a front view of the stapler unit.

FIG. 10 is a front view for explaining the loading of the needle into the needle cartridge.

FIG. 11 is a diagram for explaining a mechanism that enables the movable roller of the folding roller pair to move.

FIG. 12 is a schematic front cross-sectional view of a drive mechanism of a folding unit that is a protruding means.

FIG. 13 is a schematic plan view of a drive mechanism of a folding unit that is a protruding means.

FIG. 14 is a view for explaining the operation of the stopper structure of the pushing plate, and is a state diagram before the pushing plate is ejected.

FIG. 15 is a view for explaining the operation of the stopper structure of the pushing plate, and is a state diagram when the pushing plate is projected.

FIG. 16 is a view for explaining the operation of a cam member for centering the thrust plate.

FIG. 17 is a diagram for explaining the operation of a cam member for centering the thrust plate.

FIG. 18 is a diagram for explaining the operation of the cam member when the pushing plate is pulled back.

FIG. 19 is a perspective view for explaining the operation of the folding roller pair.

FIG. 20 is a front view for explaining the operation of the pair of folding rollers, and is a state diagram before a sheet bundle starts to be folded.

FIG. 21 is a front view for explaining the operation of the pair of folding rollers, and is a diagram illustrating a state where folding of a sheet bundle is started.

FIG. 22 is a front view for explaining the operation of the pair of folding rollers, showing a state in which a sheet bundle is bent and conveyed.

FIG. 23 is a flowchart for explaining the operation of the sheet folding apparatus.

FIG. 24 is a diagram for explaining the mechanism of sheet tearing and wrinkling during folding processing. FIG. 6A is a front view of the pair of folding rollers showing a state in which sheets are shifted when folding of a sheet bundle is started by the pair of folding rollers. (B) It is the figure which looked at (a) from the right side. FIG. 3C is a perspective view of the sheet bundle when wrinkles occur on the inner sheet. (D) is a perspective view of the sheet bundle when the inner sheet is torn.

FIG. 25 is a diagram for explaining a sheet bundle conveyance resistance reducing state. FIG. 6A is a front view of the pair of folding rollers showing a state in which sheets are shifted when folding of a sheet bundle is started by the pair of folding rollers. (B) It is the figure which looked at (a) from the right side. FIG. 4C is a front view of the sheet bundle when wrinkles do not occur.

FIG. 26 is an explanatory diagram illustrating an image recording portion and a folding allowance portion on a sheet.

FIG. 27 is a layout diagram of an intermediate sensor, a stopper sensor, and a discharge sensor for detecting a sheet tear.

FIG. 28 is an explanatory diagram illustrating a state in which a sheet bundle is stacked on a stacking tray by a roof tile.

FIG. 29 is a diagram illustrating a state in which a sheet bundle is stacked on a stacking tray.

FIG. 30 is a block diagram schematically showing a control system of the stitcher unit.

FIG. 31 is a front view for explaining the shape of a vertical path.

FIG. 32 is a perspective view of a folding roller pair according to another embodiment.

FIG. 33 is a perspective view of a folding roller pair according to another embodiment.

FIG. 34 is a front view for explaining the operation of a pair of folding rollers in the conventional sheet folding apparatus, and is a state diagram before starting to bend a sheet bundle.

FIG. 35 is a front view for explaining the operation of a pair of folding rollers in a conventional sheet folding processing apparatus, and is a diagram illustrating a state where folding of a sheet bundle is started.

FIG. 36 is a front view for explaining the operation of a pair of folding rollers in a conventional sheet folding apparatus, and is a state diagram in which a sheet bundle is bent and conveyed.

FIG. 37 is a front view for explaining the operation of the pair of folding rollers in the conventional sheet folding apparatus, and is a state diagram immediately before the conveyance of the sheet bundle is completed.

FIG. 38 is a front view for explaining the operation of a pair of folding rollers in a conventional sheet folding apparatus, and is a state diagram immediately before the conveyance of a sheet bundle is completed.

FIG. 39 is a front view for explaining the operation of the pair of folding rollers in the conventional sheet folding apparatus, and is a state diagram immediately before the conveyance of the sheet bundle is completed.

[Explanation of symbols]

A Body of Image Forming Apparatus (Copier) B Sheet Processing Apparatus C Finisher Unit D Stitcher Unit E Copying Machine (Image Forming Apparatus) F Folding Roller Pressing Force P Sheet Pg Image Recording Portion Ps Center t Folding Allowance 1 Document Feeder 3 Image forming unit 4 Sheet cassette (sheet stacking unit) 8 Multi tray (sheet stacking unit) 61 Stapler unit 178, 278, 378 Folding roller pair (one pair of rotating bodies) 178a, 278a, 378a Fixed roller (rotating body pair) 178b, 278b, 378b Movable roller (rotator pair) 178c, 278c, 378c Rotating shaft 178d, 278d, 378d Movable roller shaft 178g, 278g, 378g Overall pressure contact portion 178g, 278g1, 378g1 Axial pressure contact portion (remaining axial portion) ) 178g2, 278g , 378g2 Rotation direction pressure contact part (Rotation direction remaining part) 178h, 278h, 378h Nip release part (Escape part) 79 Projection unit (Projection means) 79a Thrust plate 80 Support arm 80a Support point 81 Spring 229 D home sensor (Home position detection means) )

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H072 AA22 CA01 GA01 GA08 JA02 3F108 AA01 AB01 AC02 AC03 BA03 CD07 GA02 GA03 GA04 GB01 GB03 HA02 HA39 HA44

Claims (9)

[Claims] An intermediate portion of a sheet bundle is pressed against a pair of rotating body pairs that can rotate while being pressed against each other, and the nip portion between the pair of rotating body pairs, thereby forming the sheet bundle into a “<” shape. Protruding means that bends and protrudes in a shape, and escapes on the outer periphery of at least one of the pair of rotating bodies while leaving a part of a direction parallel to the axis of the rotating body and a part of the rotating direction. Forming a portion, when the pair of rotating bodies starts to rotate, the axially remaining portions in a direction parallel to the axis of the rotating body left by the escape portion are in contact with each other; The sheet folding processing apparatus, wherein during rotation of the rotating member, the remaining portions in the rotation direction of the rotating body left by the escape portion sandwich the sheet bundle. 2. The method according to claim 1, wherein the intermediate portion of the sheet bundle is bound by a binding member, and the relief portion is formed at a portion facing the binding member in a rotation direction of the rotating body. The sheet folding apparatus according to claim 1. 3. The sheet bundle according to claim 1, wherein the intermediate portion of the sheet bundle is bound by a binding member, and the rotation-direction remaining portion is formed at a position where the binding member has escaped. Sheet folding processor. 4. The sheet folding apparatus according to claim 1, wherein a plurality of the remaining portions in the rotation direction are formed within a range of the width of the sheet bundle. 5. The apparatus according to claim 1, wherein at least one of the remaining portions in the rotation direction is formed within a range of the width of the sheet bundle and one at each side outside the width of the sheet bundle. Or the sheet folding apparatus according to 3. 6. A sheet folding apparatus according to claim 1, wherein at least one of said pair of rotating bodies is adapted to escape from the other. . 7. A sheet folding process according to claim 1, further comprising a home position detecting means for detecting a rotation start position of said pair of rotating bodies. apparatus. 8. A sheet stacking unit on which sheets are stacked, an image forming unit for forming an image on the sheet supplied from the sheet stacking unit, and folding the sheet on which the image is formed. 3,
An image forming apparatus comprising: the sheet folding processing apparatus according to any one of 4, 5, 6, and 7. 9. The image forming apparatus according to claim 8, wherein the sheet folding processing apparatus folds the sheet with an image forming surface inside.