JPH11322171A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of binding a book of a bundle of sheets without generating a tear, even when a cover of high quality paper is provided. SOLUTION: In this image forming device forming images on a sheet, binding the sheet for which images are formed and two-folding the sheet, the device has an image forming means main body A having an image forming means forming images on the sheet and a sheet processor D binding plural numbers of sheets for which images are formed by the image forming device main body A and further two-folding and binding a book of the sheets. For a sheet to be a cover to be two-folded and bound, images are formed for only a cover surface by the image forming device main body A and the cover surface is fed to the sheet processor D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a sheet processing apparatus capable of sequentially taking in sheets formed with images by image forming means, binding a plurality of sheets by binding means, and folding the sheets in half.

[0002]

2. Description of the Related Art Today, some image forming apparatuses such as copiers are capable of binding a sheet processing apparatus, binding a plurality of sheets and folding the sheets into two, thereby enabling bookbinding. In such an apparatus, an image is formed on both sides of a sheet by the image forming apparatus main body, the sheets are sequentially taken in, the stapler unit is driven to bind the sheet bundle at approximately the center of the sheet bundle, and this is conveyed to the folding means. And then fold it in half.

[0003] The structure for folding in two is constituted by a folding roller composed of a pair of rollers and a protruding means composed of a pushing plate or the like, and the binding position of the sheet bundle is projected to the nip portion of the pair of rollers by the pushing plate. Folded
The folded sheet bundle is pressed and conveyed by a pair of rollers and folded in two. As a result, the sheet bundle discharged to the discharge tray is discharged in a state where the sheet bundle is folded at the binding position at the center of the sheet and bound.

[0004]

When the folding process is performed in the sheet processing apparatus, if the coefficient of friction between the sheets is low, a slip occurs when the folded sheet bundle is pulled in by the folding roller, and the binding is performed. There is a risk that tearing will occur at the location. Therefore, it is desirable to use a sheet having a high coefficient of friction between the sheets.

However, in the case of recording by the electrophotographic method at the time of forming the image, the sheet on which the toner image has been transferred is conveyed to a fixing means and fixed by applying heat and pressure.
At this time, it is general that silicone oil or the like is adhered to the transfer roller in contact with the toner image transfer surface of the sheet so that the toner is not reversely transferred. Will drop.

[0006] When a sheet bundle to be bound and folded is provided with a cover sheet on the surface thereof, high-quality paper is often used only for the cover, and when the silicon oil adheres to the high-quality paper, friction occurs. The decrease in the coefficient is remarkable as compared with the case of plain paper, and there is a possibility that only the front cover portion is torn during the folding process.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide an image forming apparatus capable of binding a sheet bundle without tearing even if it has a cover of high quality paper. Is provided.

[0008]

A typical configuration according to the present invention for achieving the above object is to form an image on a sheet, bind the image-formed sheet and fold it in two in an image forming apparatus. An image forming means main body having an image forming means for forming an image, and a sheet processing apparatus for binding a plurality of sheets formed by the image forming apparatus main body and further folding the book in two; For a sheet to be a cover, the image forming apparatus main body forms an image only on the front side and sends the image to the sheet processing apparatus.

In the above configuration, since the back surface of the sheet serving as the cover does not come into contact with the fixing roller in the image forming apparatus main body, silicon oil or the like does not adhere to the back surface or the amount of adhesion is extremely small. And thus the coefficient of friction does not decrease. Therefore, even if high-quality paper is used as the cover, tearing or the like does not occur in the folding process.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment according to the present invention will be described with reference to the drawings.

FIG. 1 is a diagram illustrating the internal structure of a copying machine as an example of an image forming apparatus to which the present invention can be applied. This copying machine is configured by connecting a sheet processing apparatus B to an image forming apparatus main body A. I have. Further, the sheet processing apparatus B includes a finisher unit C capable of sorting the sheets on which images are recorded by the image forming apparatus main body A by the number of copies, and a stitcher unit D capable of binding and folding and binding a plurality of sheets.

Here, first, the overall configuration of the image forming apparatus will be briefly described, and then the configuration of the sheet processing apparatus B will be described in detail for the finisher unit C and the stitcher unit D.

[Overall Configuration of Image Forming Apparatus] The image forming apparatus main body A optically reads a document automatically fed from a document feeding apparatus 1 mounted on the upper portion of the apparatus by an optical unit 2, and
The information is transmitted as a digital signal to the image forming means 3 and is recorded on a recording sheet such as plain paper or an OHP sheet.

A plurality of sheet cassettes 4 containing sheets of various sizes are mounted in the lower portion of the image forming apparatus main unit A. Images are recorded by a photographic method. That is, based on the information read by the optical unit 2, a laser beam is irradiated from the light irradiating unit 3 a to the photosensitive drum 3 b to form a latent image, which is developed with toner and transferred to a sheet. And is permanently fixed by applying heat and pressure.

In the case of the single-sided recording mode, the sheet is fed to the sheet processing apparatus B. In the case of the double-sided recording mode, the sheet is conveyed to the re-sending path 7 by switchback, and the sheet recorded on one side is re-imaged by the image forming means 3. After forming an image on the other surface by conveying the sheet to the other side, the sheet is sent to the sheet processing apparatus B.

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

The finisher unit C in the sheet processing apparatus B is configured as shown in FIG. 2, and is adapted to discharge a sheet according to each mode such as an offset mode and a staple mode in addition to a normal discharge mode. This enables discharge processing.

Here, in the offset mode, when the sheets are sorted and discharged for each number of copies, the side guide 11 is moved when the first sheet of each portion is discharged, and the sheet is moved by a predetermined amount in the sheet width direction (sheet width). This is an operation mode in which the second and subsequent sheets of each section are normally ejected so that the boundaries between the sections can be seen.

If there is no space for moving the sheet by a predetermined amount with respect to the sheet width direction size, the reference guide 37 is used.
Is retracted below the staple tray 12, which is a temporary stacking means, to secure a sufficient amount of sheet movement.

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 stapling is performed by the stapler 13, and binding and discharging are performed for each copy.

In discharging the sheets, in addition to the normal discharge control for discharging the sheets one by one, a two-sheet discharge control capable of discharging two sheets simultaneously is possible.
In the two-sheet discharge control, the sheet sent from the image forming apparatus main body A to the sheet processing apparatus B is retained in the buffer path 14 provided in the finisher unit C, and is superposed on the next sheet to be discharged. This is an operation control for discharging simultaneously.

On the other hand, the stitcher unit D in the sheet processing apparatus B is configured as shown in FIG. 3, and aligns the sheets discharged from the image forming apparatus main body A by the number of copies, and performs stapling by the staple unit. And
In addition, this is folded into two and bound. In brief, the sheet discharged from the image forming apparatus main body A is conveyed to the vertical path 60 of the stitcher unit D, and stacked and aligned by the number of copies so that the lower end of the sheet abuts against the stopper 62. At 61, the sheet is stapled and stapled at two places at the center position in the sheet length direction (sheet conveyance direction).

Next, the stopper 62 is moved downward so as to move the sheet bundle so that the binding position reaches the nip position of the folding roller 78. The sheet bundle is pushed by the pushing plate 79, and the sheet bundle is moved at the binding position. Fold roller to be folded in two
Carry the nip at 78. As a result, the sheet bundle bound at the center in the sheet length direction and folded and bound in two are discharged to the stacking tray 106.

[Finisher Unit] Next, the configuration of each part of the finisher unit C in the sheet processing apparatus B will be described in detail.

The sheet P discharged from the image forming apparatus main body A to the finisher unit C according to the present embodiment is conveyed by the conveying rollers 15 in the normal mode, and the pair of upstream discharge rollers 16 and the pair of downstream discharge rollers. At 17 the sheet is discharged to the stack tray 18. A plurality of stack trays 18 are provided so as to be movable in the vertical direction, and are moved in the vertical direction by a driving source built in a lower part thereof. In the case of sorting and discharging, the sheets P can be discharged in a state of being sorted for each copy by sequentially moving the plurality of stack trays 18 to the discharging port. In the offset mode and the staple mode, it is possible to perform offset processing or stapling processing on one stack tray 18 and discharge the sheets in a sorted state. Further, in the case of the interruption mode, the sheet can be discharged to the upper tray 19 without being discharged to the stack tray 18.

{Offset Ejection Processing} As described above, the finisher unit C according to the present embodiment can perform the sort processing in the offset mode. In this mode, as shown in FIG. When discharging all copies on the tray 18 and discharging them in units of copies,
By shifting the first sheet P1 of each part in the sheet width direction from the second and subsequent sheets P, the boundaries between the parts are clarified.

For this purpose, the downstream discharge roller pair 17 is provided with a downstream discharge roller 17a provided on the unit body and a swing guide 20 which can swing about a rotation axis with respect to the unit body.
When the swing guide 20 is opened upward, as shown in FIG. 4, the downstream discharge roller pair 17 is separated from the movable discharge roller 17b. Also,
A side guide 11, which is alignment means for guiding one side in the width direction of the sheet P, between the upstream discharge roller pair 16 and the downstream discharge roller pair 17, is configured to be movable in the sheet width direction. Thus, in the offset mode, when the first sheet P1 of each set to be sorted is discharged, as shown in FIG. The swing guide 20 is opened upward when the sheet P is conveyed and falls on the staple tray 12, and then the side guide 11 is moved in the direction of the arrow to move the first sheet P1 by a predetermined amount. Then, the swing guide 20 is closed and the sheet P1 is discharged to the stack tray 18. After that, the second and subsequent sheets P are normally discharged, so that the sheet P shown in FIGS.
As shown in (1), the first sheet P1 of each copy is ejected in a shifted state. As described above, when there is no space for moving the sheet by a predetermined amount with respect to the sheet width direction size, the reference guide 37 is retracted below the staple tray 12 to secure a sufficient sheet moving amount.

{Two-sheet discharge control at offset} In the above-described offset discharge, when the first sheet P1 of each copy is discharged, the offset processing of the sheet P1 is necessary as described above. Until the processing is completed, the second and subsequent sheets P cannot be discharged. For this reason, it is necessary to wait for the discharge of the second sheet, which requires a long processing time.

Therefore, in the present embodiment, the second sheet P is retained in the buffer path 14 during the offset processing, and the second sheet and the third sheet are discharged at the same time. Even in the offset mode, the sheet can be discharged without waiting for the sheet to be discharged, thereby shortening the processing time.

The two-sheet ejection control for that will be described. While the first sheet is being offset processed,
When the second sheet is conveyed from the image forming apparatus main body A to the finisher unit C, the upstream ends of the first flapper 21 and the second flapper 22 are positioned downward as shown in FIG. It is sent to the buffer path 14. The preceding sheet (the second sheet in the case of the offset mode) P2 sent to the buffer path 14 is a buffer roller 23 driven and rotated.
And a buffer roller that rotates by being pressed against the sheet.
By 24, it is sent in the direction of the arrow shown in the figure so as to wind around the buffer roller 23. Here, the third flapper 25 is the preceding sheet P
2 so as to be fed in the direction of winding around the buffer roller 23.

The leading edge of the preceding sheet P2 is detected by the buffer sensor 26, and when the leading edge of the preceding sheet P2 reaches a predetermined position, the driving of the buffer roller 23 is stopped and stopped in the buffer path 14. Then, as shown in FIG. 6, when the succeeding sheet (third sheet in the offset mode) P3 enters, the buffer roller 23 starts rotating, and as shown in FIG. P2 and the succeeding sheet P3 are conveyed in an overlapping manner. Further, when the trailing edge of the preceding sheet P2 passes the position of the third flapper 25, the third flapper 25 is moved toward the upstream discharge roller pair 16 in the direction of the two sheets P2,
The sheet P3 is rotated so as to be fed, and is discharged onto the stack tray 18 with two sheets P2 and P3 stacked.

By performing the above-described two-sheet discharge control operation, the upstream discharge roller pair can be operated during the offset processing operation.
There is no need to discharge the sheet from the printer 16, so that it is not necessary to stop the operation of the image forming apparatus main body. For this reason, even in the offset mode, the processing time does not become long, and quick offset discharge can be performed.

In this embodiment, one sheet P is wound around the buffer roller 23. However, in order to increase the time for performing the offset operation, two or more sheets are wound, and three or more sheets are wound. Can be simultaneously discharged. Also, the sheet wound around the buffer roller 23 can be used even if there is no subsequent sheet.
Only the sheet wound around 23 can be discharged and stacked.

Also, the case where the sheet to be offset is the first sheet of each unit during the sorting process in the offset mode has been described as an example, but the present invention is not limited to this. For example, the last sheet of each unit may be used. The present invention is effective even when is offset. Further, the number of sheets to be offset is not limited to one, but may be a plurality of sheets.

The two-sheet discharge control is performed not only at the time of offset processing, but also at the time of staple processing in a staple mode described later, so that the time required for staple processing can be effectively used. .

{Sheet standby position for two-sheet discharge control} In the above-described two-sheet discharge control, the preceding sheet P2 waiting in the buffer path 14 and the following sheet P3 discharged from the image forming apparatus main assembly A are used. Is required to be conveyed so that the amount of deviation of the leading end of the sheet P3 becomes constant. Therefore, when the trailing sheet P3 passes the position of the approach sensor 27 shown in FIG. The rotation of the buffer roller 23 is started after a lapse of a predetermined clock after the elapse of a predetermined clock, so that the amount of deviation between the leading ends of the preceding sheet P2 and the following sheet P3 is constant.

However, the conveying speed of the succeeding sheet P3 discharged from the image forming apparatus main body A is changed depending on the image forming mode, the type of the sheet, and the like. On the other hand, since the activation timing of the buffer roller 23 is constant, if the conveying speed of the preceding sheet P2 and the following sheet P3 are different, the leading ends of both sheets P2 and P3 may be shifted.

In the present embodiment, the transport speed of the succeeding sheet P3 according to the image forming mode and the type of sheet can be obtained from the image forming apparatus main body. The position of the leading edge of the preceding sheet P2 to be stopped in the buffer path 14 is changed. Specifically, in FIG. 6, when the preceding sheet P2 is made to stand by in the buffer path 14, the transport amount from when the leading edge of the preceding sheet passes through the buffer sensor position to when it stops is determined by the transport speed of the succeeding sheet P3. Is set to be large when the speed is fast, and to be low when the speed is slow. As a result, from the start of rotation of the buffer roller 23, the preceding sheet P
The time until the leading edge of No. 2 reaches the confluence with the following sheet P3 is short when the conveying speed of the following sheet P3 is high, and long when the conveying speed of the following sheet P3 is low. Therefore, even if the start timing of the buffer roller 23 is constant, the leading end of the preceding sheet P2 and the leading end of the following sheet P3 are always conveyed so as to have a predetermined deviation amount.

In order to make the leading end of the preceding sheet P2 coincide with the leading end of the succeeding sheet P3, the rotation start timing of the buffer roller 23 is changed in addition to the method of changing the standby position of the preceding sheet P2 as described above. It is also possible. For example, the preceding sheet P2 is made to stand by at a fixed position in the buffer path 14, and when the conveying speed of the following sheet P3 is high, the rotation of the buffer roller 23 is performed immediately after the succeeding sheet P3 has passed the entry sensor 27. And the following sheet P
In the case where the transport speed of the third sheet is slow, control is performed such that the rotation of the buffer roller 23 is started after a lapse of a predetermined time after the succeeding sheet P3 has passed the entry sensor 27. Thus, the following sheet P
By changing the transport start timing of the preceding sheet P2 according to the transport speed of No. 3, it is also possible to keep the amount of deviation between the leading ends of both sheets P2 and P3 constant.

The transport speed of the succeeding sheet P3 may be obtained from the image forming apparatus main body A as described above. However, since the transport speed is generally the same as that of the preceding sheet P2, It may be obtained by detecting the transport speed of the preceding sheet P2.

{Discharge Signal Sending Timing in Two-Sheet Discharge Control} A sheet is sent from the image forming apparatus main body A to the sheet processing apparatus B, and when a predetermined process is performed, a sheet discharge signal is sent. However, as shown in the flowchart of FIG. 8, in the two-sheet discharge control, when the sheet is detected by the carry-in sensor 28 (see FIGS. 2 and 6) (S1), and when the preceding sheet P2 is conveyed into the buffer path 14, Sends a discharge signal for the preceding sheet P2 (S2), and then outputs the following sheet P2.
3 is conveyed to a predetermined position, and a discharge signal of the succeeding sheet P3 is transmitted after two sheets have been discharged (S3 to S5). After the discharge signal is transmitted (S2 in FIG. 8).
If the apparatus stops due to a jam (paper jam) or the like occurring in the succeeding sheet P3, the preceding sheet P2 in the buffer path 14 together with the succeeding sheet P3 by the jam processing.
Will also be removed. For this reason, when the image formation is resumed after returning from the jam, the preceding sheet P
Although 2 has not been discharged to the stack tray 18 or the like, the apparatus body recognizes that it has been discharged by sending a discharge signal. Therefore, the page is skipped and processed.

Therefore, in the present embodiment, as shown in the flowchart of FIG. 9, when the preceding sheet P2 is conveyed to the buffer path 14, no discharge signal is sent out, and the preceding sheet P2 is superimposed on the succeeding sheet P3. Both sheets are discharged from the buffer path 14, and the leading ends of both sheets P2 and P3 are connected to the upstream discharge roller pair 1.
6 and the preceding sheet P2 at the time when it is detected by the discharge sensor 29 (see FIGS. 2 and 6) immediately before the sheet P3.
(S11 to S15).

With this configuration, when the preceding sheet P2 is waiting in the buffer path 14 (FIG. 9).
(S11 and S12), even if the apparatus stops due to the jam of the succeeding sheet P3, the discharge signal of the preceding sheet P2 is not sent at that time. Therefore, after the preceding sheet P2 is removed from the buffer path 14 by the jam processing, when the jam is recovered and the image formation is restarted, the image can be formed again from the preceding sheet P2, and the page is skipped and the processing is performed. It can be prevented from being done.

The above-described two-sheet ejection control is effective when performed during the offset processing or the later-described stapling processing. However, in other cases, the two-sheet ejection control may be performed. Conversely, it is naturally possible to set so that the two-sheet ejection control is not performed.

{Shape of Side Guide} Sheets discharged by the above-described two-sheet discharge control or by the normal discharge mode are discharged to the stack tray 18 by the upstream discharge roller pair 16 and the downstream discharge roller pair 17 in FIG. However, at this time, the staple tray 12 located between the pair of discharge rollers 16 and 17 has fallen downward (see FIG. 2).
For this reason, as shown in FIG.
When the leading end of the sheet is curled downward, it hangs down on the staple tray 12, and when conveyed in that state, when the sheet is nipped by the downstream discharge roller pair 17, FIG.
As shown in (b), the sheet may be folded at the leading end.

For this reason, in this embodiment, as shown in FIG. 11, the side guide 11 is formed in a substantially triangular shape, and the upper portion is formed so as not to fall into the staple tray 12.
The side guide 11 is made to stand by at a position inside (a sheet discharge area) of the width of the discharged sheet, whereby the discharged sheet P is moved to the side guide 11 as shown in FIG.
And is conveyed to the downstream discharge roller pair 17 without hanging down on the staple tray 12. Accordingly, the sheet is discharged without being folded by the downstream discharge roller pair 17 as described above.

If the shape of the side guide is cut off in front of the downstream discharge roller pair 17 as shown in FIG. 10A, the sheet P can be guided above the side guide 500. The sheet P may hang down on the staple tray 12 after the guide by the side guide 500 disappears. For this reason, like the side guide 11 (see FIG. 11) of the present embodiment, the upstream discharge roller pair 16 and the downstream discharge roller pair
It is desirable that the sheet P has a shape capable of guiding the sheet P up to 17.

If an auxiliary guide 30 for guiding the sheet P is provided between the upstream discharge roller pair 16 and the side guide 11, it is more effective to prevent the sheet P from sagging.

As described above, the side guide 11 guides the sheet P by being located in the discharge area of the sheet P. In the offset mode or the staple mode, the side guide 11 drops the sheet P onto the staple tray 12, and It is necessary to push the width direction end to align. Therefore, in offset mode and staple mode,
Immediately after the leading edge of the first sheet is nipped by the downstream discharge roller pair 17 (the state in FIG. 11), the side guide 11 is retreated to the outside of the sheet width (outside the sheet discharge area) as shown in FIG. Let it. Even in this case, since the leading edge of the first sheet has already passed through the downstream discharge roller pair 17, the leading edge of the sheet will not be folded, and the side guide 11 will be located in the next sheet alignment standby state. it can.

{Stacking on Staple Tray} In the staple mode, as shown in FIG. 14, the swing guide 20 is opened, and the sheet P is discharged onto the staple tray 12 by the pair of upstream discharge rollers 16, and then the oscillating guide is opened. The knurled belt 32, which is rotated by the driving of the paddle 31 and the upstream discharge roller pair 16 provided on the moving guide 20, is rotated in the direction of the arrow to return the sheet P to the position where the rear end of the sheet P contacts the rear end stopper 33.
After the sheet P is pushed to one side by the side guide 11 and aligned, the stapler 13 staples the sheet.

When the sheet P is discharged to the staple tray 12, if the discharge speed of the upstream discharge roller pair 16 is high, the sheet that has passed through the upstream discharge roller pair 16 is opened because the swing guide 20 is open. The P is ejected so as to jump out, and proceeds forward (toward the stacker tray) too much, and it takes time to pull it back. Further, if the sheet has advanced too far forward, the sheet may not be returned to the knurled belt 32 even if the sheet is pulled in by hitting with the paddle 31, and the sheet may not be aligned on the staple tray.

Therefore, in the present embodiment, in the staple mode, when the rear end of the sheet passes through the pair of upstream discharge rollers 16, the rotation speed of the pair of upstream discharge rollers 16 is controlled to be low. As a result, the trailing end of the sheet discharged to the staple tray 12 falls near the knurl belt 32, and the rotation of the paddle 31 and the knurl belt
The rotation of 32 ensures that the sheet P is pulled in, and the rear end alignment can be performed.

Whether or not the trailing edge of the sheet passes through the upstream discharge roller pair 16 can be determined by detecting a predetermined time after the sheet has passed a predetermined sensor or by detecting the number of rotations of the motor. is there.

After the trailing edge of the sheet has fallen into the staple tray 12, the rotation of the pair of upstream discharge rollers 16, which has been switched to low-speed driving, is switched to high-speed. Since the pair of upstream discharge rollers 16 is also a driving source for rotating the knurl belt 32, the sheet P dropped into the staple tray 12 is quickly pulled back by the knurl belt 32, and the rear end of the sheet is hit against the rear end stopper 33. Become like

As described above, in the staple mode, the conveyance speed is reduced only when the rear end of the sheet passes through the pair of upstream discharge rollers 16, so that quick alignment can be achieved as a whole.

{Swing Guide} Here, the swing guide 20 will be briefly described with reference to FIG. The swing guide 20
The movable discharge roller 17b is rotatably held, and when the sheet is discharged, the movable discharge roller 17b is slid downward about the pivot shaft 20a by a driving mechanism 39 described later to press the movable discharge roller 17b against the downstream discharge roller 17a. Further, in the staple mode, similarly, the movable discharge roller 17b is separated upward from the downstream discharge roller 17a by the drive mechanism 39, which will be described later, pivots upward about the pivot shaft 20a. That is, the swing guide 20 plays a role as a switching means for setting the downstream discharge roller pair 17 composed of the moving discharge roller 17b and the downstream discharge roller 17a to a sheet dischargeable state or a sheet discharge disabled state.

In FIG. 13, reference numeral 34 denotes a stopper having a shutter portion 34a, which is linked when the stack tray is moved.
When the stack tray 18 passes through the discharge port 36 by closing the discharge port 36 by raising the shutter portion 34a formed at the end of the stack tray 35, The sheet (or sheet bundle) stacked on the stack tray 18 is prevented from flowing back to the discharge port 36.
When the sheet is discharged, the link 35 rotates downward about the rotation shaft 35 a as a fulcrum, and the stopper 34 opens the discharge port 36.

{Operation of Stack Tray During Two Sheet Discharge Control} Next, the operation of the stack tray 18 when only two sheets P are stapled will be described with reference to FIG. FIG. 13 is a cross-sectional view of a main part showing a position of a stack tray.

Normally, when performing staple processing, a plurality of sheets (two or more sheets) sequentially discharged onto the staple tray 12 are used.
The sheet S is a paddle 31 and a knurl belt 32, which will be described later.
As a result, the sheet is pulled back on the staple tray 12 in a direction opposite to the discharge direction, and the rear end thereof is brought into contact with a rear end stopper 33 described later to be aligned. At this time, the stack tray 18 is raised (the position indicated by the broken line in FIG. 13) so that the leading end side of the sheet P is higher than the trailing end side on the staple tray 12, so that the sheet P can be easily pulled back by using gravity. I have to.

However, when the number of sheets P to be stapled is only two (including the case of the above-described two-sheet discharge control), the lower sheet is reversed by the drive mechanism 39 described later together with the swing of the swing guide 20. Rotating downstream discharge roller 17
By a, the sheet is pulled back on the staple tray 12 in the direction opposite to the discharge direction, and the upper sheet is similarly pulled back in the direction opposite to the discharge direction by a paddle 31 and a knurl belt 32 described later. Accordingly, since the first and second discharged sheets can be pulled back and aligned without using gravity, there is no need to raise the stack tray 18 to lift the sheet front end. .

Therefore, in this embodiment, when only two sheets P are to be stapled (including the case of the two-sheet discharge control), the stack tray 18 is not moved up (down). That is, when the number of sheets P to be stapled is three or more, the stack tray 18 is raised from the solid line position in FIG. 13 to the broken line position, but when only two sheets P are stapled, the stack tray 18 is raised. Instead, the pull-back operation as described above is performed while holding at the solid line position in FIG.

With this configuration, when a bundle of two sheets is stapled, the stack tray 18
It is not necessary to move the stack tray 18 up and down.
Time can be saved, and the processing time can be greatly reduced.

{Swinging Amount of Swing Guide and Paddle Shape} Next, referring to FIGS. 14 to 16, a paddle 31 for pulling back the sheet P discharged onto the staple tray 12 in a direction opposite to the discharging direction, and The swing amount of the swing guide 20 that rotatably supports the paddle 31 will be described. 14 and 15 are enlarged views of a main part showing the state of the swing guide and the paddle when the sheet is pulled back, and FIG. 16 is an explanatory view showing the shape of the paddle.

The swing guide 20 is provided on the staple tray 12
A paddle 31 for pulling back the sheet P discharged upward in a direction opposite to the discharge direction is rotatably provided. This paddle
Numeral 31 indicates that each time one sheet P is discharged onto the staple tray 12 when the swing guide 20 is opened, the sheet P rotates in the direction opposite to the sheet discharging direction and contacts the rear end of the sheet P on the staple tray 12. The sheet P is pulled back by the frictional force generated between the sheet P and the sheet P.

Here, when the swing guide 20 is swung upward and is held back at a fixed position and is pulled back by the paddle 31 each time a sheet is ejected, sheets are ejected onto the staple tray 12 one after another. Therefore, the contact area and contact pressure of the paddle 31 in contact with the uppermost sheet P change in accordance with the change in the height (level) of the sheet on the staple tray 12, and the sheet P is returned too much. There is a risk.

Therefore, in the present embodiment, the paddle 31
Are configured so that the contact pressure on the uppermost sheet discharged onto the staple tray 12 is kept substantially constant. More specifically, as shown in FIG. 16, the shape of the paddle 31 is formed into a tapered shape in which the tip portion 31a is made thin. Fig. 16 (a)
FIG. 16 (b) shows a case where a step portion is provided on both surfaces of a front end portion 31a of the paddle 31 to form a tapered shape, and FIG. 16 (b) shows a case where a step portion is provided on one surface (the sheet contact surface side) of the front end portion 31a of the paddle 31. FIG. 16 (c) shows a case in which a step portion is provided on the other surface (non-sheet contact surface side) of the front end portion 31a of the paddle 31 to form a tapered shape. Note that the tapered shape of the tip portion 31a of the paddle 31 is not limited to the shape as shown in FIG.

By forming in this way, the tip of the paddle, which is the contact portion with the sheet, is easily elastically deformed when it comes into contact with the sheet, so that a stable return force is obtained irrespective of the number of stacked sheets, and further durability. The performance is improved.

In this embodiment, a plurality of the paddles 31 are provided in the rotation direction so that the paddle 31 comes into contact with one sheet a plurality of times in one rotation.
Thus, for example, when the paddle 31 is brought into contact with a sheet having a relatively large size twice and pulled back, only one rotation is required, and the processing time is longer than rotating one paddle 31 twice. Can be shortened. FIG. 16
(a) illustrates the case where two paddles 31 are provided in the rotation direction (twin paddle), but the present invention is not limited to this. Further, the paddle 31 is connected to each of FIGS. 16 (d), (e), (f),
The same effect can be expected even if the shape is as shown in FIG.

Further, the contact area of the paddle 31 with the sheet P discharged onto the staple tray 12 may be kept constant. More specifically, the swing amount of the swing guide 20 when it is opened (when it swings upward) is changed in accordance with a change in the height (level) of the sheet P on the staple tray 12. Specifically, for example, as the number of sheets P discharged to the staple tray 12 increases, the swing guide 20 is swung upward to keep the contact area of the paddle 31 with the uppermost sheet P constant. I keep it.

As shown in FIG. 15, the distance from the swing center (swing axis 20a) of the swing guide 20 to the rotation center of the paddle 31 is r, the swing angle of the swing guide 20 is θ, and the sheet P Assuming that the thickness of the bundle is t, the thickness t can be represented by t = rsin θ. Therefore, based on this equation, the swing amount (swing angle θ) of the swing guide 20 may be changed according to the change in the thickness t of the bundle of sheets P.

With this configuration, the contact area between the uppermost sheet P on the staple tray 12 and the paddle 31 is always kept constant irrespective of the number of stacked sheets P. Is obtained, and excessive return of the sheet P due to a change in the contact area of the paddle 31 with the sheet P can be prevented.

{Operation Timing of Paddle} The operation timing of the paddle 31 is such that the upstream discharge roller pair 16 on the upstream side of the staple tray discharges the rear end of the sheet P as shown in FIG. After the rear end is settled as shown by a broken line in the figure, the operation is performed as shown in FIG. Specifically, the rear end of the sheet P is the upstream discharge roller pair.
The paddle 31 is rotated in a direction opposite to the sheet discharging direction after a lapse of a predetermined time after passing through the discharging sensor 29 provided on the upstream side of the 16.

{Rotation speed of paddle according to sheet size}
Next, the number of times the paddle 31 is driven will be described. For example, in a configuration in which the paddle 31 is uniformly driven and rotated regardless of the size of the sheet, since the large-sized sheet has a large mass and is difficult to be pulled back, even if the paddle 31 is hit with the paddle 31 similarly to the small-sized sheet, the knurled belt 32 In some cases, it may not be possible to pull back the sheet, and there is a possibility that sheet alignment failure may occur.

Therefore, in the present embodiment, the number of times the paddle 31 is driven is changed according to the sheet size. More specifically, when the length of the sheet in the sheet conveying direction is relatively long, the number of times the paddle 31 is driven is increased. More specifically, for example, as shown in FIG.
4. Paddle 31 for LGL and LDR size sheets
The number of times of driving is two times, and A4, LTR,
In the case of B5, A4R, LTRR size sheets, the number of times the paddle 31 is driven is set to one.

With this configuration, even a sheet having a large mass can be reliably pulled back to the knurled belt 32, and the sheet alignment can be improved.

Although the number of revolutions is changed according to the sheet size here, the same control can be performed for thick paper designation or special paper (with a low surface friction coefficient).

{Moving Speed of Side Guide According to Sheet Size} Next, the moving speed of the side guide 11 for aligning the sheet P in the width direction will be described. When the sheets P are stacked on the staple tray 12, alignment in the sheet conveyance direction is performed by the paddle 31 and the knurl belt 32 as described above, and the sheet is guided by the side guide 11 to the rear end side of the sheet (the side end on the side of the rear end stopper 33). ) To move the sheet P in the width direction toward the reference guide 37 on the opposite side, thereby performing alignment in the sheet width direction. Here, when the size of the sheet P is large, its center of gravity is far from the pressing position by the side guide 11, and since its mass is large, its inertia is also high. Therefore, the leading edge of the sheet follows the movement of the side guide 11 in the sheet width direction. No, there is a possibility that sheet misalignment may occur.

Therefore, in this embodiment, the moving speed of the side guide 11 in the sheet width direction is changed according to the sheet size. More specifically, the side guide 11
The side guide 11 is moved at a low speed when the sheet has a relatively long length in the direction (sheet conveying direction) orthogonal to the moving direction (sheet width direction). More specifically, for example, as shown in FIG. 17, side guides are used for A4, LTR, and B5 sheets having a short length in the sheet conveyance direction, and A3 and LDR size sheets having a small movement amount in the sheet width direction. The moving speed of the side guide 11 is set to be low in the case of B4, LGL, and A4R, LTRR size sheets having a large moving amount in the sheet width direction.

With this configuration, the influence of inertia can be reduced, and the alignment in the width direction can be improved even for a large-sized sheet (a sheet having a long length in the conveying direction). It is also effective for a sheet size having a large moving amount in the sheet width direction.

<< Rear End Stopper >> Next, the rear end stopper 33 which contacts the rear end of the sheet P when the sheet P is aligned in the transport direction will be described with reference to FIGS. 18 and 19. FIG.

The sheet P discharged onto the staple tray 12 is conveyed in a direction opposite to the discharge direction by the paddle 31 and the knurl belt 32 described above, and abuts against a rear end stopper 33 provided at a predetermined interval in the sheet width direction. Then, alignment in the sheet conveying direction is performed.

Here, for example, as shown in FIG.
When the sheet abutting surface 501a of the rear end stopper 501 is flat, if the sheet P enters the sheet abutting surface 501a slightly obliquely, the sheet P buckles (and sinks). Rolled over or sheet butted surface 501
The edge of the sheet may hit the corners (edges) on both sides in the width direction of a and may be damaged.

Therefore, in this embodiment, as shown in FIG. 18B, both side portions in the width direction of the sheet abutting surface 33a of the rear end stopper 33 are formed in a tapered shape (tapered portion 33b).

With this configuration, FIG.
As shown in FIG. 7, even if the sheet P enters the sheet abutting surface 33a obliquely, the buckling (and sneaking) of the sheet P can be prevented by the tapered portions 33b, and the sheet edge is damaged. Sticking can be prevented.

As shown in FIG. 19, one knurl belt 32L in the sheet width direction has one rear end stopper 33L.
However, since the other rear end stopper 33R is slightly shifted in the width direction and corresponds to the other knurl belt 32R, the vicinity of the corner of the sheet abuts against the other rear end stopper 33R. In such a case (especially in the case of an R-type sheet), the sheet edge between the rear end stoppers may be drawn too much by the other knurl belt 32R, and the vicinity of the sheet corner may be bent and buckled.

Here, during the sorting process in the offset mode, it is necessary to move the side guide 11 in the sheet width direction. However, since the movable area is up to the vicinity of the knurl belt 32R, as shown in FIG. The knurl belt 32R and the other rear end stopper 33R have a configuration corresponding to a slight shift in the sheet width direction.

With this configuration, it is possible to perform offset processing on a short B5R size sheet in the sheet width direction, and to reduce the size of the entire apparatus.

Therefore, in this embodiment, as shown in FIG. 19, at the time of stapling the sheet bundle (especially at the time of binding one position of the R system sheet), the rear end stopper 33L which abuts and aligns the rear end of the sheet bundle. , 33R (in the present embodiment, the center portion), the stapler 13 is made to wait, and the stapler 13 is made to function in the same manner as the rear end stoppers 33L, 33R.
More specifically, the cover member 38 of the stapler 13 is provided with a rib 38a for regulating the rear end of the sheet bundle.

With this configuration, even when the sheet is pulled in by the other knurled belt 32R when the vicinity of the sheet corner is abutted against the other rear end stopper 33R, a standby state is provided between the rear end stoppers. Since the sheet is regulated by the stapler 13 (the rib 38a), the sheet is not pulled in too much, so that it is possible to prevent the sheet from buckling.

{Press Control of Side Guide} Next, the alignment of the sheet P in the width direction by the side guide 11 will be described. As described above, the alignment of the sheet P in the width direction is performed by pressing the one end on the rear end side of the sheet by the side guide 11 to move the sheet P in the width direction, and moving the other end to the reference guide 37 on the opposite side.
It is consistent by striking. At this time, the sheet P moved in the width direction by the side guide 11 is in contact with the knurl belt 32. For this reason, the knurled belt 32 may be twisted along with the sheet P moved in the width direction by the side guide 11, and the sheet P does not reach the reference guide 37 due to the influence of the knurled belt 32.
There is a risk of inconsistency.

Therefore, in the present embodiment, as shown in FIGS. 20 and 21, when the side guide 11 performs the widthwise alignment of the sheet P (especially for an R-type sheet having a large width alignment amount), By pressing the side guide 11 stepwise, the sheet is aligned while releasing the influence of the knurl belt 32. That is, the side guide 11
By pressing the sheet P step by step, even if the knurl belt 32 twists at the time of the pressing, the knurl belt 32
Therefore, the knurled belt 32 can be easily returned to the normal position (the state as shown in the drawing), and the restoration time until the knurled belt 32 returns to the normal position can be shortened.

Further, the side guide at the time of this sheet width alignment
The stepwise pressing control of the sheet 11 is changed according to the size of the sheet. Specifically, for example, as shown in FIG. 17, the pressing control of the first sheet of the A4, LTR, B4, and LGL size and the pressing control of the second and subsequent sheets of the LTR, B5 size are two-stage pressing. .

[0093] The term "two-stage pressing" used herein means to temporarily stop after the first pressing and then perform the second pressing. Note that the number of steps is not limited to this. Furthermore, the side guide 11 after this last pushing is
As will be described later in detail, at the pushed-in position, the sheet functions as a guide until the leading edge of the next sheet reaches the downstream discharge roller pair 17 or for a certain period of time, that is, the sheet is pressed by the side guide 11. It is in the state as it was.

Further, when the side guide 11 presses the sheet stepwise a plurality of times, the side guide 11 stops once each time the sheet is pressed, and after a lapse of time for the knurled belt 32 to return to the normal position (the return of the twist). Subsequent pressing is started.

Therefore, by aligning the sheet in the width direction by stepwise pressing the sheet with the side guide 11 as described above, the effect of the knurled belt 32 is quickly released, and the alignment of the sheet is quickly performed. Can be performed accurately.

{Shape of knurl belt} Next, FIG.
The shape of the knurl belt 32 will be described with reference to FIG. The knurl belt 32 is to further pull back the sheet pulled back by the paddle 31 in the direction opposite to the sheet discharging direction, and abut the sheet P against the rear end stopper 33 to perform alignment in the sheet conveying direction. Here, as shown in FIG. 22, if the contact surface of the knurled belt 502 with the sheet P is formed flat, the edge portion 502a of the knurled belt 502 moves in the width direction when the side guide 11 presses the sheet. The sheet S may be caught on the sheet S to be misaligned.

Therefore, in the present embodiment, the edge 32a of the knurled belt 32 is formed into a tapered shape as shown in FIG. 23 (a), or the knurled belt is formed as shown in FIG. 23 (b).
The outer peripheral surface of 32 is formed in an R-shaped cross section.

By forming in this way, the resistance to the sheet P moved in the width direction by the side guide 11 at the time of alignment is reduced, and it is possible to reduce the sheet mismatch caused by the edge portion being caught.

{Restoration of the knurl belt} Further, as described above, the alignment of the sheet in the width direction is performed by pressing one side of the rear end side of the sheet by the side guide 11 to move the sheet in the width direction and moving the other side end. The sheet P is aligned by abutting the reference guide 37 on the opposite side. At this time, the sheet P moved in the width direction by the side guide 11 is in contact with the knurl belt 32. For this reason, the knurl belt 32 may be twisted along with the sheet P moved in the width direction by the side guide 11, and the knurl may be moved when the side guide 11 moves (retreats) in a direction opposite to the sheet pressing direction. There is a possibility that the sheet P may move with the restoration of the skew of the belt 32, resulting in inconsistency.

Therefore, in this embodiment, the side guide 11
After pressing the sheet, the knurl belt 32 continues to press until it returns to the normal position (the return of the twist), and after the knurl belt 32 returns to the normal position, the pressing of the sheet by the side guide 11 is released. I have.

The side guide 11 functions as a guide for the next sheet to be fed by continuously pressing the sheet at the position shown in FIG. 21, but even if the knurled belt 32 is distorted as described above, It returns to the normal position while the pressing is continued. The side guide 11 retreats to a retreat position outside the sheet discharge area after the leading end of the sheet P being guided approaches the downstream discharge roller pair 17.

With this configuration, it is possible to prevent the sheet from being inconsistent due to the influence of the knurl belt 32.

{Reverse rotation of the downstream discharge roller when the swing guide is opened} Next, the downstream discharge roller 17 when the swing guide 20 is opened
The state of “a” and the state of the side guide 11 will be described.
When the swing guide 20 is opened, the downstream discharge roller 17a is configured to rotate in a direction opposite to the sheet discharge direction by a driving mechanism 39 described later. Normally, after the reverse rotation conveyance of the downstream discharge roller 17a is completed, the side guide
11 is performed in the sheet width direction.

However, since the first sheet (two sheets at the time of the two-sheet discharge control) is in contact with the downstream discharge roller 17a by its own weight, this becomes a resistance when the side guide 11 aligns the width. There is a possibility that sheet inconsistency may occur. This sheet and the downstream discharge roller 17a
Is smaller when the roller is rotating than when the roller is stationary.

Therefore, in the present embodiment, the sheet width alignment work by the side guide 11 is completed by the end of the reverse rotation of the downstream discharge roller 17a that pulls back the first sheet.

With this configuration, when the width of the first sheet is adjusted by the side guide 11, the influence of the frictional resistance between the first sheet and the downstream discharge roller 17a can be reduced, and the alignment of the sheet can be reduced. The performance is improved.

{Locking of Downstream Discharge Roller While Holding Swing Guide} Further, when subsequent sheets are stacked and aligned on the staple tray 12, the downstream discharge roller 17a is in a free state (rotatable). State),
The lowermost sheet on the staple tray 12 may be shifted during sheet alignment.

Therefore, in the present embodiment, when the sheets are stacked on the staple tray 12 and aligned by the drive mechanism 39 described later, the downstream discharge roller 17a is locked so as not to rotate.

With such a configuration, it is possible to reduce the displacement of the sheet due to the collision at the time of the paddle operation when the sheets are stacked and aligned on the staple tray 12.

{Reverse rotation of the downstream discharge roller when the swing guide is closed} When a bundle of sheets is stacked on the staple tray 12 and aligned, the sheet bundle is moved to the swing guide 20.
Is closed and pinched and fixed, and then stapled by the stapler 13.

Here, the paddle 31 on the staple tray 12
When the sheets are aligned by the side guide 11 or the like, the lowermost sheet of the sheet bundle may be slightly shifted.

Accordingly, in the present embodiment, the swing guide
At the time of closing and fixing the sheet bundle by closing 20, the downstream discharge roller 17a is moved by a predetermined amount (slightly) by the drive mechanism 39 described later.
When the sheet is reversed, a conveying force in a direction opposite to the discharge direction is applied to the lowermost sheet of the sheet bundle on the staple tray 12.

With this configuration, the paddle 31
Even if the lowermost sheet of the sheet bundle slightly shifts when the sheets are aligned by the side guide 11 or the like, the shift can be corrected and aligned.

{Driving Mechanism of Swing Guide and Downstream Discharge Roller} Next, the drive mechanism 39 of the swing guide 20 and the downstream discharge roller 17a will be described with reference to FIGS. 25, 26 and 27.
In the figure, reference numeral 39 denotes a drive mechanism which opens and closes the swing guide 20 and drives the downstream discharge roller 17a to rotate forward and backward.
The drive mechanism 39 includes one drive motor 40 as a drive source.
And a gear train for transmitting the driving force from the motor 40.

Further, the drive motor 40 is provided with an encoder 56 for detecting the number of rotations and a drive motor rotation detection sensor 55 for detecting the rotation speed of each roller and the amount of movement of the swing guide.

In the drive mechanism 39, the downstream discharge roller 17a rotates forward (rotates in the sheet discharging direction) when the drive motor 40 rotates forward, and the opening and closing operation of the swing guide 20 when the drive motor 40 rotates reversely. Reverse rotation (rotation in the direction opposite to the sheet discharge direction) of the downstream discharge roller 17a during the opening operation, swing guide
The closing operation of 20 and the reverse rotation of the downstream discharge roller 17a at the time of the closing operation are performed. Further, when the drive motor 40 is temporarily stopped, the swing guide 20 is held and the downstream discharge roller 17a is locked at the time of holding. Hereinafter, the configuration of the drive mechanism will be described in detail along the flow of the operation.

As shown in FIG. 25, when the drive motor 40 is rotated forward, a driving force is applied to the fixed gear 42a of the pendulum gear unit 42 meshing with the pinion gear 41 of the motor 40 to rotate and swing. The gear 42b swings to the illustrated position and meshes with the discharge gear 43 of the downstream discharge roller 17a, and the downstream discharge roller 17a rotates (forward) in the sheet discharge direction (the direction of the arrow in the drawing) to discharge and convey the sheet S. I do.

As shown in FIG. 26, when the driving motor 40 rotates in the reverse direction, a driving force is applied to the fixed gear 42a of the pendulum gear unit 42 meshing with the pinion gear 41 of the motor 40, whereby the swing gear is rotated. 42b swings to the position shown in the figure and the intermediate gear 44
The operation gear 46 rotates in the direction of the arrow in the figure via the intermediate gear 45 meshing with the intermediate gear 44. The operating gear 46 includes a gear portion 46a meshed with the intermediate gear 45,
A projection 46b that opens and closes the swing guide 20 by contacting an open / close arm 47 integrally attached to the swing guide 20, and a toothless gear portion 46c that can mesh with an intermediate gear 48 that meshes with the discharge gear 43. It has.

Therefore, when the operating gear 46 rotates in the direction of the arrow in the figure, the missing gear portion 46c meshes with the intermediate gear 48, and the discharge gear 43 meshed with the intermediate gear 48 rotates in the direction of the arrow in the figure. Then, the downstream discharge roller 17a rotates (reversely rotates) in a direction opposite to the sheet discharge direction (the direction of the arrow in the drawing) to start pulling back and conveying the sheet P, and as shown in FIG.
46b contacts the opening / closing arm 47 and pushes up the opening / closing arm 47 to push up the swing guide 20 in the direction of the arrow in the figure.

Then, when it reaches the position as shown in FIG. 27, for example, the drive of the drive motor 40 is temporarily stopped, and the swing guide 20 is kept open. At this time, the operating gear
Since the toothless gear portion 46c of the stop gear 46 is stopped while being engaged with the discharge gear 43 via the intermediate gear 48, the downstream discharge roller
17a is locked and cannot rotate.

Note that the holding position of the swing guide 20 is as follows.
As described above, in order to keep the contact area of the paddle 31 with the sheet discharged on the staple tray 12 constant,
The position can be changed according to a change in the height (level) of the sheet.

Thereafter, when the stacking alignment of the sheets on the staple tray 12 is completed and the drive motor 40 is again rotated in the reverse direction,
The discharge gear 43 rotates by the amount of engagement with the toothless gear portion 46c of the operation gear 46, and the downstream discharge roller 17a rotates by a predetermined amount (the above-described engagement) in the direction opposite to the sheet discharge direction to pull back the sheet P. Transport. At the same time, the closing operation of the swing guide 20 is performed, and after the closing is completed, the next process is prepared.

With the above configuration, it is not necessary to separately provide a drive mechanism for driving the swing guide 20 and the downstream discharge roller 17a, so that the cost can be reduced and the apparatus can be simplified.

{Close Operation of Swing Guide} As described above, the swing guide 20 is rotatable about the swing shaft 20a, and as shown in FIG. 27, when the operation gear 46 rotates in the direction of the arrow, The projection 46b provided on the operation gear 46 is a swing guide.
The swing guide 20 is opened by pushing up an opening / closing arm 47 attached to one side of the swing guide 20. And the operating gear 46
When the gear further rotates in the direction of the arrow in FIG. 27, the swing guide 20 starts to close, and when the operating gear 46 further rotates, the engagement between the projection 46 b and the opening / closing arm 47 is released, and the swing guide 20 drops by its own weight and closes. Will be.

Here, when the swing gear 20 is closed, the operating gear 46 is rotated at a high speed to increase the initial speed of the closing operation.
The impact when the swing guide 20 falls by its own weight increases,
There is a risk of disturbing the aligned sheet. In addition, the impact on the durability of the device due to the impact is unfavorably affected.

Therefore, in the present embodiment, as shown in the flowchart of FIG. 28, in the motor control for closing the swing guide 20, the swing guide 20 is closed at a high speed until the predetermined position 1 after the motor is started. (S21) When the swing guide 20 is closed to the predetermined position 1 (S22, S23), the motor output is changed (S24), and the closing operation of the swing guide 20 is configured to be delayed. When the guide 20 is closed to the next predetermined position 2 (S28, S26), the motor output is changed again (S27), and the motor drive is stopped after the swing guide is detected to be closed (S28, S29).

As a result, the swinging guide 20 rotates gently immediately before falling by its own weight, and the initial speed at the time of falling by its own weight is reduced. For this reason, the impact of the swinging guide 20 that falls by its own weight is reduced, and the aligned sheet is not disturbed, the impact noise is also reduced, and the durability of the apparatus is not adversely affected.

Note that when the swing guide 20 is closed,
When the specified time has elapsed since the motor was started, the swing guide 20
The closing operation of the opening / closing arm 47 is completed as shown in FIG.
Turns the sensor flag 49 to turn on a close sensor (not shown). Thereby, the device recognizes that the swing guide 20 is closed.

Therefore, if the closing sensor does not turn on even after the lapse of the specified time, it means that an error has occurred in the closing operation. However, actually, the protrusion 46b of the operation gear 46
There is a case where the rotation of the drive motor 40 is stopped due to the impulse resistance between the drive motor 40 and the opening / closing arm 47 and the fluctuation of the load of the connected gear. In such a case, the work can be continuously and smoothly continued by transmitting the larger rotational force to rotate the operation gear 46.

That is, in the present embodiment, as shown in the flow chart of FIG. 29, when the swing sensor 20 is closed (S31 to S37), the closing sensor is not turned on even after a specified time has elapsed after the motor is started. (S32), the motor output is changed to transmit a larger torque (S32).
33). Thereafter, if the closing sensor does not turn on even after the set time has elapsed, a closing error display of the swing guide 20 is displayed, and the apparatus is stopped.

If the closed state of the swing guide 20 cannot be detected in the initial closing operation as described above, the motor output is further increased and the closing operation is performed again to reduce the occurrence of error stoppage of the apparatus. And a continuous and smooth sheet post-processing becomes possible.

{Rotation direction switching control} When the drive motor 40 is driven in the reverse direction to switch the pendulum gear unit 42, the swing gear 42b is driven to rotate with the rotation of the fixed gear 42a. Ejection gear 43 if rotating
Alternatively, it is difficult to mesh with the intermediate gear 44, and there is a risk of causing tooth skipping. This causes noise and
Unnecessary wear of the gears reduces durability and equipment reliability.

Therefore, in this embodiment, as shown in FIG. 30, it is first determined whether or not the rotation direction of the drive motor 40 is switched according to the control of the apparatus (S41). If the rotation directions do not match (S42), The drive of the drive motor 40 is controlled to a low speed (S43). When a predetermined time sufficient for switching has elapsed (S44), the drive motor is driven at a normal control speed (S45).

With such a structure, the swing gear
Engagement between the gear 42b, the discharge gear 43, and the intermediate gear 44 can be ensured, tooth skipping and noise can be prevented, and a device having excellent durability can be obtained.

{Staple Operation} As described above, the bundle of sheets P stacked on the staple tray 12 is fed to the discharge gear.
The sheet is nipped by the downstream discharge roller pair 17 fixed by 43, and is bound by the stapler 13 in this state. Although various combinations of closing positions are conceivable, in the present embodiment, a mode for binding one corner and a mode for binding two sides can be selected as shown in FIG.

When the stapler 13 is not at the predetermined stapling position, it is necessary to move the stapler 13, but this may cause the sheet bundle stacked on the staple tray 12 to move. Therefore, when moving the stapler 13, the end of the sheet bundle is pressed by the side guide 11. Accordingly, there is no possibility that the alignment of the stacked sheets P is disturbed.

However, if the binding operation is performed with the side guide 11 pressed, the sheet bundle may be deflected in the width direction due to the pressing of the side guide 11, so that a staple defect may occur. is there.

In order to perform the binding operation, the side guide 11 is released from the bundle of sheets P as shown by the solid line in FIG. It is configured to perform a binding operation. Thus, the folding of the sheet bundle caused by the pressing of the side guide 11 can be released, and stapling failure can be prevented.

{Needle Replacement} As shown in FIG.
13 is configured to mount the needle cartridge 50,
When refilling the needle, the needle cartridge 50 is replaced.
In the staple cartridge 50, a plurality of staple plates 50a formed by connecting a plurality of binding needles can be loaded.

The stapler 13 has a needle cartridge 50 inside.
Needle cartridge sensor 13a that detects the frame of the needle, a needle detection sensor that directly detects the needle exposed on the lower surface of the needle cartridge 50
13b, a stylus detection sensor 13 provided at the tip of the stapler 13
c is provided.

FIG. 33 is a flowchart showing the control performed when the needle cartridge 50 is replaced. When a job involving the binding process is started (S51), or when the absence of a staple is detected while the job is being continued (S52), the user is notified of the absence of the staple, and the user is prompted to replace the staple cartridge 50 (S53). ). The user operates the stapler door 51 on the front of the finisher unit C.
1 (see FIG. 1) is opened, and the needle cartridge 50 filled with the needle plate 50a is mounted on the stapler 13.

At this point, the fact that the needle cartridge 50 is mounted on the stapler 13 is detected by the sensor. When the needle cartridge 50 is inserted to some extent, the needle detection sensor 13b detects the lower surface of the needle cartridge 50 and determines that there is a needle. However, at this time, the cartridge is not yet mounted and fixed at a predetermined position, which causes inconvenience in feeding and ejecting the needle.

Therefore, in the present embodiment, it is determined whether or not both the needle cartridge sensor 13a and the needle detection sensor 13b are turned on (S54), thereby recognizing that there is a needle. Thus, not only the presence of the needle can be detected, but also the state in which the needle can be ejected can be recognized, and a reliable needle replacement operation can be performed.

{Needle cueing processing} Detection of needle presence (S54)
Then, when it is detected that the stapler door 51 is closed (S55), a needle leading process is performed (S56). Conventionally, the processing has been performed by performing blank hitting a predetermined number of times as needle leading. However, in this case, even when the needle plate 50a has already reached the leading end of the needle cartridge 50, this cannot be recognized, so that unnecessary hitting is performed.

In this embodiment, the stapler 13 is provided with a head needle detection sensor 13c, which is disposed at a position facing the tip of the needle cartridge 50. By detecting the end of the needle heading process by this head needle detection sensor 13c,
There is no longer a risk of wasting the needle by blind hitting. On the other hand, in the control of performing the blank hitting until the head needle detection sensor 13c detects the needle, there is no limit to the number of times of blanking, so even if a needle jam occurs in the needle cartridge 50, the blanking is performed forever. There is a possibility that the processing will not end continuously.

Therefore, as shown in FIG.
When 56) is started, first, the counter n is reset (S
61). Then, the needle plate 50a is conveyed by one stitch (S62). When the head needle detection sensor 13c detects a stitch (S6).
3) The process is terminated, and if not detected, the counter n is incremented by one (S64). Here, it is determined whether or not the counter n has reached a specified number of times (S65). If the number of times is within the specified number, idling is further repeated. If the number of times exceeds the specified number, the user is notified that a needle jam has occurred. It notifies (S66).

As described above, even when the needle is detected by the head needle detection sensor 13c, an infinite loop of the operation of the needle cueing process can be avoided by setting a limit on the number of times of idling. If a staple jam (S66) occurs in the staple head search process (S56), it is recognized that there is no staple in the staple cartridge replacement process (S57).

{Needle Jam Processing} In some cases, a staple jam occurs while the binding operation is continued. When the finisher unit C detects a staple jam, it is conventionally determined whether or not a staple jam has occurred after performing the binding process (S71) as shown in FIG. 35 (S72), and no staple jam has occurred. In this case, the sheet bundle is discharged (S73) and the process is continued, and if it has occurred, this is notified to the user (S74) and the process is interrupted. However, in this case, the stapler 13 remains at the position where the binding operation has been performed, and even if the user tries to clear the jam by opening the stapler door 51, it may be difficult to reach the stapler.

Accordingly, in this embodiment, as shown in FIG. 36, after performing the binding processing (S81), first, the sheet bundle is discharged (S82), and then it is determined whether or not a staple jam has occurred (S83). . If a staple jam has not occurred, the process is continued.If a staple jam has occurred, the stapler
13 is moved to the initial position near the stapler door 51 (S84), and then the user is notified of the jam (S85), and the process ends. Here, the initial position is near the stapler door 51,
When this is opened, it is the position where the user can most easily clear the jam. The reason why the sheet bundle is discharged is that there is a risk that the stapler 13 may come into contact with the stapler 13 when the stapler 13 is moved to the initial position and cause damage.

By moving the stapler to the initial position even when a staple jam occurs, there is no danger that the user will not easily reach the stapler.
The device can be easily maintained.

{Stapler Initialization During Jam Clearing} The stapler door 51 of the finisher unit C is opened and closed at the time of needle replacement as described above, but is opened and closed when the sheet being conveyed has jammed. No need. However, it is possible for the user to open and close this,
At that time, the stapler may be mistakenly moved.

Here, the position control of the stapler is controlled by the amount of movement from the initial position, and the current position is not always confirmed by means such as a sensor. Therefore, when the position of the stapler is moved during the sheet jam processing, the apparatus cannot recognize this, and
If the binding process is performed as it is, the stapling will be performed at an incorrect position.

Therefore, in this embodiment, as shown in FIG. 37, when the opening and closing of the stapler door 51 is detected (S91).
When the binding process is performed (S92), the stapler 13 is temporarily returned to the initial position before performing the binding process (S93).
After that, it is configured to move to the closed position again (S94) and perform the binding process (S95). Since the binding process is performed after confirming the position of the stapler 13 as described above, even if the stapler 13 is moved by the user, there is no possibility that the stapler 13 will be stapled to an incorrect position.

{Sheet Bundle Discharge} As described above, when the binding process is completed, the drive motor 40 rotates in the forward direction, the pendulum gear unit 42 meshes with the discharge gear 43, and the downstream discharge roller pair.
17 rotates in the transport direction and stacks the sheets P in a stack tray.
Discharge to 18.

At this time, when a sheet bundle that has been bound at one corner is discharged, the end face on which the binding process has not been performed is likely to shift. This phenomenon depends on the sheet size,
The influence is different depending on the number of sheets, and the smaller the size of the sheet, the smaller the friction between the sheets.

Conventionally, the control for discharging the sheet bundle by the downstream discharge roller pair 17 is fixed, and the control of the drive motor 40 is performed with 100% output as shown in FIG. 38 (a). For example, if the ejection speed is reset based on a medium number of sheet bundles in this state, excessive conveyance force is applied to a small number of sheet bundles, and the sheet bundle is likely to be shifted. Also increases the mass, thereby lowering the discharge speed.

Therefore, in the present embodiment, first, when discharging a sheet bundle that has been stapled at one location, the stack tray 18 is raised, and the stacking surface on the stack tray 18 is brought closer to the downstream discharge roller pair 17. It is discharging in the state. As a result, the resistance between the sheet bundle and the stacking surface on the stack tray 18 is reduced, and the shift is less likely to occur.

Further, the stack tray 18 which is brought closer to the downstream discharge roller pair 17 is moved to the downstream discharge roller pair 17 at the rear end of the sheet bundle.
Just before exiting, is lowered by a certain amount. Thus, it is possible to prevent the sheet bundle rear end from flowing back into the apparatus due to contact with the downstream discharge roller pair 17 or the like.

Further, as shown in the figure, the rising speed of the drive motor 40 at the time of discharge is controlled to be slow depending on the size and number of sheets, so that a sheet bundle having different sizes and numbers of sheets can be handled. That is, driving is started with a driving force of about 80% for a large-sized sheet and about 60% for a small-sized sheet.

More specifically, as shown in FIG. 38 (b), when the size of the sheet is small, the rising speed is made slower than in the case of the large size, thereby preventing the displacement caused by rapid acceleration. . Also, when the number of stacked sheets is large, the driving torque at startup is lower than when the number is small,
Control is performed so that the torque from the drive roller is sufficiently and evenly transmitted to the lowermost sheet of the sheet bundle. Then, the speed gradually shifts to the normal conveyance speed and drive torque, and finally, a sheet bundle of any size and number of sheets is discharged at substantially the same speed.

Thus, even when a sheet bundle that has been stapled at one location is discharged, displacement of the unbound end face can be prevented, the stacking performance on the stack tray 18 can be improved, and the size or size can be improved. It is possible to discharge at the same speed regardless of the number of bundles. Also, the drive motor 40
Is not driven at 100% output, so that the operation noise generated by the device can be reduced.

Further, by bringing the stack tray 18 closer to the downstream discharge roller pair 17, the sheet bundle to be discharged can be prevented from bending and the lowermost sheet of the sheet bundle can be prevented from buckling.

{Mixed Load Detection} When the discharged sheets already stacked on the stack tray 18 are discharged in a different sheet size or in a sheet processing mode, the stackability is higher than that of stacking sheets of the same size or stacking sheets by the same processing. Therefore, it is necessary to set a limit on the number of sheets that can be stacked as mixed loading.

For this reason, a stack sensor 53 for detecting whether or not sheets are stacked on the tray is provided substantially at the center of the stack tray 18. When the sheets P are stacked on the stack tray 18, Will be treated as a consolidation under the following conditions.

(1) The case where the sheets P stacked on the tray are not the sheets discharged and stacked from the finisher unit C.

(2) When sheets P of different sheet sizes are discharged and stacked on the stack tray 18 by the finisher unit C.

(3) A case where the sheets are discharged and stacked on the stack tray 18 in different processing modes by the finisher unit C.

The finisher unit C in this embodiment is configured to refer to the detection signal of the stack sensor 53 when starting image formation, and not to refer to this signal after image formation has started. This is because if the detection signal of the stack sensor 53 is referred to even after the image formation is started and the sheets are further discharged, the first discharged sheet may be erroneously recognized as being mixed. .

{Detection of Load Amount} The level detection of the uppermost surface of the sheets or sheet bundles stacked on the stack tray 18 is performed by the distance measuring sensor 54 provided above the swing guide 20. The distance measurement sensor has a light emitting unit that irradiates a sheet bundle with light rays such as infrared rays, and a light receiving unit that receives light rays that are irregularly reflected by the sheet bundle, and performs level detection by measuring the angle of the reflected light. Things.

When a sheet or the like is discharged onto the stack tray 18, the trailing end of the sheet P may be caught by the finisher unit C as shown in FIG. If level detection is performed in such a state, accurate level detection may not be performed. Therefore, when the sheet P is discharged, the stack tray 18 once moves downward and rises again,
The sheet P is configured to settle on the stack tray 18.

When detecting the level of the sheets P stacked on the stack tray 18, it is desirable that the distance measuring sensor 54 detect the level when the stack tray 18 is raised.
However, actually, when the stack tray 18 moves up, the next sheet P has already been discharged, so that the sheet on the stack tray 18 cannot be seen because of the interruption.

When the level is detected when the sheet P descends, the sheet P may not be settled at that moment. Therefore, the level is detected twice or more at predetermined intervals, and the error range is continuously detected. It is configured to acquire as a detection result when the value in is acquired. Thus, the determined actual level detection can be performed, and the production capability of the device can be exhibited.

The position of the stack tray 18 after being raised is controlled based on data obtained by level detection so that the height of the stacking surface is always constant (paper surface height control).

Here, the stack tray will be described with reference to FIG.
A configuration for recognizing the stacking amount of sheets (the height of stacked sheets) on the sheet 18 will be briefly described. The detailed configuration is disclosed in JP-A-9-48549. Fig. 39 (b)
FIG. 2 is a perspective view of a main part showing a schematic configuration of a tray unit, a driving unit of the tray unit, and a position detecting unit of the tray unit.

In this embodiment, the three stack trays 18 are respectively fixed to the tray frame 57 to form a tray unit 58, and the three stack trays 18 are integrally formed with the finisher frame 59 of the finisher unit C. It can be moved up and down. The vertical movement of the tray unit 58, that is, the vertical movement of the stack tray 18, causes the forward and reverse rotation of the stacker motor 209 to rotate.
The rack part 58a provided in a part of the tray unit 58 by 5
, The tray unit itself is moved up and down relative to the finisher frame 59 in the direction of the arrow in the figure.

An encoder 226 is mounted on the output shaft of the stacker motor 209. By detecting the pulse amount of the encoder 226 by the stacker motor clock sensor 227, the tray unit 58 is moved from the home position which is the initial position. The number of pulses moved, that is, the amount of movement of the stack tray 18 can be known. still,
The detection of the home position of the stack tray 18 is performed by the tray home position sensor 228 detecting a tray unit flag 57a provided below the tray frame 57.

The tray unit 58 is operated by a copy operation signal or the like.
After the home position is detected (the tray unit flag 57a is detected by the tray home position sensor 228), the predetermined stack tray 18 is moved to the predetermined position with respect to the downstream discharge roller pair 17 based on the detection signal of the distance measuring sensor 54. The sheet discharged by the downstream discharge roller pair 17 is positioned and received by the stack tray 18.

In order to keep the uppermost position of the sheet on the stack tray 18 at a predetermined amount from the downstream discharge roller pair 17, the stack tray 18 is lowered by a predetermined amount every time a sheet (or a sheet bundle) is stacked. It is supposed to.

The number of clocks the tray unit 58 has moved from the home position, that is, the stack tray
The movement amount of 18 is the MPU of the finisher unit C described later.
200 (see FIG. 42).

With the above configuration, the position of the stack tray 18 and the position of the uppermost surface of the sheets on the stack tray 18 (level detection) are determined, and the stacking amount of the sheets stacked on the stack tray 18 (the Height) can be recognized.

As described above, by detecting the position and the level of the stack tray 18, the stacking amount of the sheets P stacked on the stack tray 18 is detected, and exceeds the predetermined stacking amount determined by the processing mode and the sheet size. If it is judged that there is, it recognizes that it is full.

However, even when it is detected that the sheet is full, the sheet P on the stack tray 18 may not be settled due to the curl or the state where the rear end is caught. For this reason, there is a case where the apparatus is determined to be full but not fully loaded, and the apparatus is stopped, which may cause a decrease in productivity.

Therefore, in this embodiment, the stack tray
When the top surface of the sheet on the stack 18 is higher than a predetermined height, that is, when the stacking amount of the sheet on the stack tray 18 is detected a plurality of times in succession, the sheet is fully loaded for the first time. Is determined, and the apparatus is stopped. More specifically, the stack tray 18 is moved up and down, and the stacking amount of sheets on the stack tray 18 is detected for each operation (or after the operation ends), and the stacking amount of the sheets exceeds a predetermined amount. If this is continuously detected a plurality of times (three times in the present embodiment), it is determined that the sheet is full, and the apparatus is stopped for the first time.

Further, in the present embodiment, the full sheet detection as described above is performed every time a predetermined number of sheets (for example, five sheets) are discharged to the stack tray 18.

As a result, it is possible to detect whether or not the sheet stacking amount exceeds a predetermined amount after eliminating the curl of the sheet generated on the stack tray 18 or the jam of the sheet rear end. Nevertheless, if it is still detected that the stacking amount of sheets exceeds the predetermined amount continuously, it is determined that the sheets are full and the apparatus is stopped. Can be prevented, and sufficient productivity can be exhibited.

It should be noted that, when the full sheet is detected as described above and the apparatus is stopped, the user is prompted to remove the stacked sheets (or sheet bundle) from the stack tray 18. I have.

{System stop timing when full load is detected}
However, even when the sorting process is being performed, if the image formation is always stopped by the detection of the full load as described above, the sheet bundle that is being sorted is stacked on the stack tray 18. Since the processing is completed, the handling of the stacked sheets may be complicated. On the other hand, a certain allowance is usually set for the full load detection on the stack tray 18, so that even when the stack tray 18 is full, it is still possible to load.

Therefore, in this embodiment, as shown in FIG. 40, when full loading is detected during the image forming and stacking operation (S101) (S102), it is determined whether or not one bundle is completed (S103). If the image formation of the bundle is not completed, the image formation is continued without stopping the image formation.
With such a configuration, even when the sheet bundle is removed from the stack tray 18 by the full load detection, there is no sheet bundle in the middle of the sorting process, and the handling is simplified.

[0189] Then, the distance measuring sensor 54 detects the full load, and if the sort processing is not being performed, it is determined that the full load is detected, and the image recording is stopped (S104).

{Special Sheets} The sheets conveyed and discharged and stacked on the stack tray 18 are special sheets, especially OH sheets.
In the case of a P sheet, the light emitted from the distance measuring sensor 54 is not diffusely reflected on the surface of the OHP sheet and is almost specularly reflected.
An error of 20 to 30 mm (experimental value) will occur. For this reason, if normal control is performed and full load detection is performed, or if stack height control is performed, the stack tray 18 will be lifted because the upper surface of the stack is recognized as being farther (lower) than reality. Depending on the loaded sheet, the discharged sheet collides with the discharge port, and the discharged sheet may collide with the discharged sheet and damage the sheet.

Therefore, in this embodiment, as shown in FIG. 41, the stacked sheets including the sheets fed from the main body multi-tray (manual tray) are stacked on the stack tray.
It is determined whether or not it has been extracted from above (S111), and if it has been extracted, the about detection flag is cleared (S112).
), That is, it is not about detection.

Then, the about detection flag is turned off (S11).
In the case of 3), normal tray control is performed assuming that no stacked sheets are present on the stack tray 18 or that sheets having no detection error of the distance measuring sensor are stacked on the stack tray 18 (S114). If the about detection flag is ON (S113), the about detection control (S11) is performed.
5) Do it.

Here, about detection means that the distance measurement sensor 54
If the level of the discharge sheet loading surface on the stack tray 18 measured in the above is not reliable due to special sheets etc.,
This error is preliminarily estimated and corrected. In the present embodiment, there is a possibility that sheets fed from the main body multi-tray (manual tray) may be stacked on the stack tray 18. I have.

[0194] About detection control indicates that the control is made lower than a predetermined height of the loading surface, specifically, about 30 mm lower, taking into account the error of the sensor.

After stacking the discharged sheets on the stack tray 18 (S116), it is determined whether or not the stacked sheets are targets for about detection (S117). This determination is made in the same manner as described above, based on whether or not the stacked sheets are fed from the main body multi-tray (manual tray).

According to this determination, if the object is to be subjected to about detection, the about detection flag is set (S118), and in the next tray control, the about detection flag (S118) is set.
115) is configured to do.

If the object is not subjected to the about detection, the loading amount detection and the sheet surface height control (S121) are performed.
) Is performed, but when the object is not the target of the about detection, only the above-mentioned load amount detection is performed (S119).

In the above-described embodiment, control for processing all sheets fed from the main body manual feed slot as special sheets has been described. Here, it is determined whether the stacked sheets are special sheets and the Turn on the detection flag,
The control for turning off will be described.

This determination is made by moving the stack tray 18 to two points at different heights where the movement amount is known in advance.
The distance is calculated by the distance measuring sensor 54 at the point. On the other hand, the distance by which the stack tray 18 has been moved is measured by a movement amount detecting means (not shown), and the difference between the measured value and the difference between the distances measured by the distance measuring sensor is larger than a predetermined amount (generally, the distance measured by the distance measuring means). If the measured value is large), it is determined that the loaded sheet is a target of the about detection.

Thus, the sheet to be conveyed can be measured by a distance measuring sensor.
In the case of 54, even if it is a special sheet such as an OHP sheet whose distance is difficult to measure, or if it is changed to a special sheet in the middle, almost the same sheet processing as a normal sheet can be performed.

The measurement of the OHP sheet by the distance measuring sensor is a fixed value (20 to 30 mm) as compared with the plain paper as described above.
However, the variation of the measured value according to the number of sheets is the same as that of plain paper. Therefore, when it is recognized that the sheet to be discharged is an OHP sheet, the stack tray 18 is shifted downward by the predetermined value, so that the full load detection and the height control using the distance measuring sensor 54 can be performed in the same manner as usual. it can.

{Configuration of Control System of Finisher Unit}
Here, a configuration of a control system in the finisher unit C of the sheet processing apparatus B will be briefly described with reference to FIG.

In FIG. 42, 200 is M as control means.
PU, the MPU 200 includes a carry-in sensor 28, an entry sensor 27, a buffer sensor 26, a discharge sensor 29, a distance measurement sensor
54, stack sensor 53, drive motor rotation detection sensor 55 for detecting the number of rotations of drive motor 40, needle cartridge sensor
13a, a needle detection sensor 13b, a cue sensor 13c, a stacker motor clock sensor 227 for detecting a pulse amount of an encoder 226 provided on an output shaft of the stacker motor 209, and a home position of the tray unit 58 (the stack tray 18 thereof). A signal from the tray home position sensor 228 or the like is input.

The first flapper solenoid 201 for switching the first flapper 21, the second flapper solenoid 202 for switching the second flapper 22, and the third flapper 25 via the respective drivers D 1 to D 11 based on the signals. Switchable third flapper solenoid 203, buffer roller 23
And the upstream discharge roller pair 16 and the knurl belt 32,
In addition, the shutter unit 34 is moved up and down by rotating the shutter unit 34 in the reverse direction.
In order to rotate the paddle 31, the buffer transport motor 20
Paddle solenoid for connecting / disconnecting the driving force from 4
206, a side guide motor 207 for slidingly moving the side guide 11, a reference guide solenoid 20 for retracting the reference guide 37 from above the staple tray 12 during a sheet shift
8, a driving motor 40 for oscillating the oscillating guide 20 and for driving the downstream discharge roller 17a in a normal / reverse direction, a stacker motor 209 for moving the stack tray 18 up and down, a stapler motor 210 for binding the stapler 13 and feeding staples, It controls a stapler moving motor 211 for moving the position of the stapler 13 and the like.

Each motor controls a moving amount, a speed and the like by a control input pulse or an encoder coder input for detecting a rotation amount.

[Stitcher Unit] Next, the configuration of each part of the stitcher unit D in the sheet processing apparatus B will be described in detail. As described above, the stitcher unit D shown in FIG. 3 conveys the sheet discharged from the image forming apparatus main body A into the vertical path 60 including the path guides 60a and 60b, and binds the sheet center by the stapler unit 61. Later, the sheet is folded and discharged.

The sheet P discharged from the image forming apparatus main body A is fed to the vertical path 60 of the stitcher unit D by the operation of the first flapper 21, and the lower end thereof is brought into contact with the stopper 62 to be stacked and aligned. An upper roller pair 63, which is a conveying means, is provided above the vertical path 60, and a plurality of flappers 64 are provided downstream thereof. In this embodiment, the flapper
Numeral 64 is composed of two first flappers 64a and second flappers 64b, so that the transport path can be selectively switched according to the size of the sheet P.

A movable guide 65 is provided in the vicinity of the flapper 64, and is urged toward the flapper 64 by the urging means 65a to form a part of the transport path of the vertical path 60. The movable guide 65 can expose the inside of the vertical path 60 near the flapper 64 by gripping and rotating the handle 65b, and can process a jammed sheet.

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

{Lower Roller Pair} A stapler unit 61 described later is provided substantially at the center of the vertical path 60.
An anvil 61d is disposed at a position facing the stapler unit 61 with the anvil 61d interposed therebetween. Downstream of the stapler unit 61, there is provided a lower roller pair 67 which is a conveying means, and a driving roller 68 as a driving rotating body to which a driving force is transmitted from a driving source (not shown), and presses a sheet against the driving roller 68. And a pickup roller 69 as a moving rotator that is driven and rotated.

As shown in FIG. 43, the pickup roller 69 is attached to one end of a transfer roller arm 69a, and the other end of the transfer roller arm 69a is connected to a vertical path 60 by a rotating shaft 69b.
Is rotatably supported by the path guide 60b. An elastic member 69c is attached to a substantially central portion of the transport roller arm 69a to urge the pickup roller 69 against the drive roller 68. On the other hand, a compression release arm 70 that can be driven by a solenoid (not shown) is provided on the transport roller arm 69a, and the pickup roller 69 can be separated from the drive roller 68. Thus, the pickup roller 69 can be displaced between a pressing position where the sheet is pressed against the driving roller 68 and a separating position where the sheet is separated from the driving roller 68.

{Pressing Contact of Pickup Roller} Lower Roller Pair 67
When the sheet P is conveyed, the tip of the sheet P first passes through the position of the pickup roller 69, and then the roller 69 is pressed against the sheet as shown in FIG. The sheet P is pinched and transported. At this time, the sheet P sent later enters the drive roller 68 side of the already stacked sheets P, and is conveyed while sliding with the already stacked sheets.

[0213] Here, the pickup roller 69 is driven by the drive roller 68.
If the sheet P is constantly pressed against the sheet P, a conveying force is applied to the sheet P that has already reached the stopper 62 and is stacked, and the sheet may be buckled. Therefore, as shown in the present embodiment, by bringing the pickup roller 69 into pressure contact only when necessary, the consistency of the sheets is improved, and accurate loading on the vertical path 60 can be performed.

{Separation of Pickup Roller} Further, at a position where the leading end of the sheet P approaches the stopper 62 by a predetermined distance, FIG.
As shown in (b), the pickup rollers 69 are separated from each other. In this embodiment, the predetermined distance from the stopper 62 is set to 10 mm, and the pickup roller
After the sheet 69 is separated, the sheet P is conveyed to the stopper 62 by the inertia of its movement and its own weight. Note that the position of the leading end of the sheet P is recognized based on the distance conveyed after the leading end of the sheet passes through the sheet sensor 66.

Here, if the pickup roller 69 is conveyed while being pressed against the drive roller 68 until the sheet P reaches the stopper 62, the sheet P buckles or rebounds when the pickup roller 69 separates, and the alignment becomes poor. It may be disturbed. Therefore, by separating the pickup rollers 69 at an early stage as shown in the present embodiment, the sheet P is not conveyed excessively, and the above problem can be avoided.

{Driving Roller When Pickup Roller is Separated}
As described above, if the pickup rollers 69 are separated before the sheets P are stacked on the stopper 62, if the number of stacked sheets is still small, the sheets P vigorously advance in the vertical path 60, rebound, and disturb the alignment. There is a risk. Also, when the number of stacked sheets increases, the inside of the vertical path 60 becomes narrower, the friction required to pass the vertical path 60 increases, and the vertical path 60 may not reach the stopper 62.

Therefore, in the present embodiment, the drive roller 68 is configured to maintain the drive rotation even after the pickup roller 69 is separated. 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. As a result, the sheet P is reliably conveyed to the stopper 62 and pressed, so that the sheet P can be surely aligned.

{Vertical Pass Shape} The sheets P stacked against the stopper 62 are aligned in the width direction by the alignment member 71. At this time, since the sheet P is in the upright state, if the sheet P has no waist, buckling will occur. Therefore, in the present embodiment, the path guide 60a is provided with a raised portion 60c that protrudes into the transport path of the vertical path 60, and is formed by bending the vertical path 60 in the horizontal direction. As a result, the stacked sheets P also bend in the horizontal direction, that is, a vertical waist occurs. Therefore, the sheets P can be stacked without buckling.

On the other hand, if the sheet P is bent in the horizontal direction, it is not preferable when the stapler unit 61 performs the binding process. Therefore, in the present embodiment, as shown in FIG. 45, the vertical path 60 is bent between the upper and lower portions of the stapler unit 61, and the sheet P is configured to bend in the vertical direction at substantially the center. That is, as shown in FIG. 46, the sheets P are stacked with the lower part bent in the horizontal direction and the substantially central part bent in the vertical direction. Thus, the sheets can be stacked without buckling, and the position where the binding process is performed can be made flat.

{Stopper Mechanism} The drive mechanism of the stopper 62 will be described with reference to FIG. Slide members 62 a are attached to both ends of the stopper 62, and are slidably supported along the stopper frame 72. Further, a stopper drive belt 73 stretched over a drive pulley 73a and an idler pulley 73b is fixed to the stopper 62. A drive gear 73d is fixed to a rotation shaft 73c of the drive pulley 73a, and a stopper drive motor 74 is connected to the drive gear 73d. That is, when the stopper driving motor 74 rotates, the driving force is transmitted, the stopper driving belt 73 rotates, and the stopper 62 can be driven up and down.

A stopper sensor 75 is provided on the sheet stacking surface of the stopper 62, and can detect that the leading end of the sheet P has hit the stopper 62. A flag 62b is formed below the stopper 62, and is configured to be detected by the stopper home sensor 76 when the stopper 62 reaches the home position.

{Stapler Unit} Next, the mechanism of the stapler unit as sheet binding means for binding a sheet bundle will be described.

As shown in FIG. 48, the stapler unit 61
Are arranged at symmetric positions with respect to the center in the sheet width direction at the center position in the transport direction of the sheet bundle aligned with the vertical path 60 by the support plate 77 fixed to the frame.

Referring to FIG. 48, the stapler unit 61 includes
A forming unit 61b as an upper needle driving means supported so as to be swingable about a rotation shaft 61a, and a drive unit
61c and an anvil 61d.

Below the stapler unit 61, a vertical path 60 for guiding a sheet bundle by path guides 60a and 60b and an anvil 61d is formed. This vertical path 60
Guide surface 60b of path guide 60b for guiding the sheet bundle
1 and the binding surface 61d1 of the anvil 61d for binding the guided sheet bundle are configured to have an angle α with each other. The path guide 60a on the upper surface having the angle α and forming a vertical path has a cutout hole 60a1 of a size that does not interfere when the forming portion 61b of the stapler unit 61 swings.

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. . This needle cartridge 61
e, the plate-shaped binding needle 61f is inserted into the staple cartridge 61.
e is urged downward by a spring 61g provided on the uppermost side of e, and is configured to apply a conveying force to the needle feed roller 61h disposed on the lowermost side.

The binding needle 61f sent out by the needle feed roller 61h swings the forming part 61b in the direction of the arrow in FIG. 48 (counterclockwise direction in FIG. 48) around the rotation shaft 61a. Each book 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 gear 61k is rotated.
By the action of the eccentric cam that is attached integrally with k,
The forming portion 61b is moved in the direction of the arrow in FIG.
d) to perform a staple driving operation (clinch operation), and the driven staples 61f are moved to the anvil 61 on the lower surface of the sheet bundle.
The sheet bundle is stapled by folding at d.

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 them. Here, loading of the stapler into the stapler unit 61 will be described.

The stapler unit 61 according to the present embodiment
As shown in FIG. 49, two staple cartridges 61e are attached to bind two locations in the sheet width direction, and when one of the staple cartridges 61e has no binding staples, as shown in FIG. The absence of a needle is detected.

When the absence of the staple is detected, the stapler unit 61 shown in FIG. 49 is pulled out in the direction of the arrow, and a new binding staple is loaded in the staple cartridge 61e. cartridge
If the needle remains in 61e, one of the needle cartridges 61e
There is a possibility that the staples of the other staple cartridge 61e may be exhausted immediately after the staple is loaded with only e, and it is inefficient to stop the apparatus and pull out the stapler unit 61 and load the staple each time.

Therefore, in the present embodiment, when the absence of the staple is detected, the stapler unit 61 is pulled out, and
A staple is loaded into one of the staple cartridges 61e having no staples, and the remaining staples are replaced with new staples even if the other staples remain in the other staple cartridge 61e. A message prompting the user to load the needle at the same time is displayed on the operation panel as a display unit.

According to this display, two needle cartridges
By simultaneously loading the needles into the 61e, the two needle cartridges 61e are in principle in a needleless state at the same time,
Even if the needles do not run out simultaneously, if 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 loading them simultaneously, each needle cartridge 61
e can be loaded more efficiently than when the needle is loaded each time.

In this embodiment, two needle cartridges 61e are provided. However, in the case of a stapler unit 61 provided with three or more needle cartridges 61e, similarly, the needles of all the needle cartridges are simultaneously replaced. .

After the needle is loaded as described above, the stapler motor 61i (see FIG. 48) is driven to perform the cueing of the needle. It is necessary to detect whether the cueing of the needle has been performed.
Although this cueing can be detected by a sensor or the like, in the present embodiment, this is performed by detecting the drive current value of the stapler motor 61i.

That is, when the stapler motor 61i is driven to perform cueing, before the cueing of the needle (idling state), the load applied to the stapler motor 61i is small. Fig. 50
As shown in FIG. 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 is
As shown in Fig. 50 (b), it becomes larger than the idling state. Therefore, the current value for driving the stapler motor 61i is detected,
If the current value is smaller than the predetermined value, it is before the cueing, and if the current value is larger than the predetermined value, it is detected that the cue has been performed.

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

{Staple Post-Processing} After the stapler unit 61 is driven to bind the sheet bundle P conveyed and aligned to the vertical path 60 at the center in the sheet conveyance direction as described above,
The stopper 62 is moved downward to convey the sheet bundle to the folding position. At this time, as shown in FIG. 51, if the stapled binding needle 61f is fitted into the groove 61d2 of the anvil 61d, even if the stopper 62 is moved downward, the binding needle 61f
May be caught in the groove 61d2, and the sheet bundle P may cause conveyance failure.

Therefore, in this embodiment, as shown in FIG. 51, before conveying the stapled sheet bundle P downward, the pickup roller 69 of the lower roller pair 67 is moved once in the direction of the arrow in FIG. It is configured to swing. This allows
The sheet bundle P is pressed toward the path guide 60a by the pickup roller 69 as a displacement unit, and the groove portion of the anvil 61d is formed.
The binding needle 61f fitted into 61d2 surely comes out of the groove 61d2. Accordingly, the binding needle 61f is
Since the stopper 62 does not move downward in the state of being fitted in d2, it is possible to reliably prevent sheet conveyance failure.

Here, in the present embodiment, an example is shown in which the sheet is displaced by swinging the pickup roller 69 so that the binding needle 61f comes out of the groove 61d2. The binding needle 61f has the groove 61
A special member may be provided as a displacement means for displacing the sheet so as to escape from d2, and the member may be operated to perform the operation.

When the sheet bundle is conveyed downward by lowering the stopper 62, the pickup roller 69 is driven by a driving roller.
68 and the drive roller 68 is
Is driven to rotate in the direction of lowering.

As a result, when the sheet bundle falls due to its own weight, the driving roller 68 made of a material having a high friction coefficient is used.
Does not generate a frictional load when descending. Therefore, it is possible to reliably follow the stopper 62 that descends, and to guarantee the accuracy of the folding position.

{Fine adjustment of binding position and folding position}
In order to accurately perform the binding process and the later-described folding process at the center (center) in the transport direction of the sheet bundle, it is necessary to move the stopper 62 so that the center of the sheet bundle is accurately located at the binding position and the folding position. . However, the length of the sheet may not be constant due to an error at the time of cutting, expansion and contraction due to humidity, and the like, and the binding position and the folding position may not be at the center of the sheet bundle P. It is necessary to finely adjust the position of the stopper 62 as a supporting means.

Conventionally, a stopper is screwed into a long hole provided in a frame supporting the stopper, and the position of the stopper can be finely adjusted within the range of the long hole. Is fine-tuned.

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

Therefore, in this embodiment, the movement amount of the stopper 62 by the above-described drive mechanism (see FIG. 47) is controlled by an instruction from input means such as an operation panel provided in the image forming apparatus main body A or the sheet processing apparatus B. It is configured to allow fine adjustment.

More specifically, the amount of movement (elevation amount) when the stopper 62 is moved 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, before stapling, is It is configured to be finely adjustable in accordance with an instruction from an operation panel (not shown) provided in the image forming apparatus main body A. For example, the movement amount from the home position to the lower end position of the sheet of each size is usually constant for each sheet size, but this movement amount is adjusted by an amount according 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 is moved 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 the sheet. A fine adjustment can be made by a dip switch (not shown) or an operation panel of an electric board provided in the processing apparatus B. The amount of movement 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 (70 mm in the present embodiment) regardless of the sheet size. The amount of movement of the stopper 62 at the time of lowering is finely adjusted by adding or subtracting an amount corresponding to the dip switch, and the stop position is changed by the 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.

In addition, the sheet may be slightly elongated during conveyance due to roller pressure, temperature, humidity and the like. 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 automatically adjusted according to the detection result.

For example, as shown in the flowchart of FIG. 52, when a sheet is conveyed to the vertical path 60, one of the upper sensors 66a to 66c detects this according to the sheet size. From the time when the sensor detects the leading edge of the sheet (S131), the pulse counter (not shown) of the conveying motor is turned on (S132), and the pulse from when the trailing edge of the sheet passes the sensor position to when the sensor is turned off is turned on. The number is counted (S133, S134). This allows
The length of the sheet sent to the vertical path 60 can be accurately detected. 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 are automatically controlled by the control means in accordance with the length of the conveyed sheet (slightly stretched sheet). The calculated value is finely adjusted (S135), and the stopper 62 is moved according to the movement amount after the fine adjustment.

If the amount of movement of the stopper is automatically and finely adjusted according to the sheet length detected at the time of conveyance as described above, it is not necessary for the user to make fine adjustment settings, and the sheet can be adjusted more accurately and easily. It is possible to stop at the binding position and the folding position.

{Folding of Sheet Bundle} As described above, the binding position is conveyed by the downward movement of the stopper 62 until the binding position reaches the position of the folding roller 78 disposed below the stapler unit 61, where it is pushed by the pushing plate 79a. While being stuck at the binding position, the sheet is nip-conveyed by the folding roller 78 in a two-fold state and is folded in half. Next, this sheet folding configuration will be described with reference to FIGS.

As shown in FIG. 53, the folding roller 78 includes a fixed roller 78a rotatable about a fixed rotating shaft 78c.
And a movable roller 78b rotatably attached to a support arm 80 rotatable about a fulcrum 80a on the apparatus frame, and a spring locked to one end of the support arm 80.
The two rollers 78a and 78b are configured to be pressed against each other by 81. With this configuration, the pitch between the folding rollers 78 is corrected according to the thickness of the sheet bundle P to be nipped.

The structure for driving the folding roller 78 is shown in FIG.
As shown in FIG. 55, a motor pulley 83 is fixed on the output shaft 82a of the folding motor 82. This motor pulley
The driving force of 83 is transmitted to the pulley portion of the idler gear pulley 85 via the timing belt 84.
The idler gear pulley 85 has the pulley portion and the gear portion coaxially.

Also, folding gears 86 and 87 are fixed to the shaft of the above-mentioned folding roller 78, and both gears 86 and 87 mesh with each other. One end of the folding gear 86 meshes with a gear portion of the idler gear pulley 85. Further, the folding gear 86 meshes with the idler gear 88.

The turning force of the folding motor 82 is
Idler gear pulley 85 from timing belt 84
Is transmitted to Then, the rotation of the idler gear pulley 85 is transmitted from the folding gear 86 to the folding gear 87, and the folding roller 78 is driven. At the same time, the rotational force is also transmitted to the idler gear 88 meshing with the folding gear 86. The idler gear 88 transmits a rotational force to a discharge roller described later.

In FIG. 54, reference numeral 79 denotes a protruding unit as protruding means, which includes a protruding plate 79a, holders 79b, 79
d, shafts 79c, 79e, etc. The veneer
79a is held by holders 79b and 79d.
The shafts 79c and 79e are fixed to. This shaft 79c, 79e
A roller (not shown) is rotatably attached to the outer periphery of the device, and the roller slides in a groove 89 formed in the main body frame.

Reference numeral 90 denotes a projecting motor, and a motor pulley 90a is fixed on the output shaft. Reference numeral 91 denotes an idler gear pulley, which has a pulley portion and a gear portion 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 is meshed with a gear 126 having a shaft 93 in a part. As shown in FIG. 55, flags 95a and 95b are fixed on the rotating shaft 94a of the gear 94, and the flags 95a and 95b have partially cutouts. A protruding home sensor 96a and a protruding position sensor are provided at positions where the notches of the flags 95a and 95b are detected.
96b is provided. This protruding home sensor 96a
Is disposed so as to detect at a position where the pushing plate 79a is pulled in from the sheet conveying surface formed by the path guides 60a and 60b, and a pushing position sensor 96b detects at a position where the pushing plate 79a is completely pushed. It is arranged to be.

As shown in FIG. 55, a rotating plate 97 having a shaft 97a is fixed to the other end of the gear 94 on the rotating shaft 94a in the same manner as the gear 94, and synchronized with the gear 94. It is configured to rotate.

The torque of the protrusion 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 93 moves circularly. One end of a link 98 is fitted to the shaft 93, and the other end of the link 98 is fitted to a shaft 79c of the projecting unit 79. Similarly, one end of the link 98 is fitted to the shaft 97a on the rotating plate 97, and the other end of the link 98 is connected to the protrusion unit 79.
Is fitted to the shaft 79c. 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 a roller (not shown). Perform a linear motion.

Similarly, the other end of the projecting unit is also
The rotational movement of the rotating plate 97 and the shaft 97a on the rotating plate 97 is converted into a linear movement of the projecting unit via a link. In this way, the protruding unit 79 is driven by both ends thereof, and always slides in the direction of the arrow in FIG. 54 in parallel with the folding roller 78.

As shown in FIGS. 55 and 56, the rotating plate
Stopper shafts 97b and 97c are provided on a surface of the 97 opposite to the shaft 97a, and a stopper member 99 is provided on the main body frame.
It is arranged so as to be swingable about 99a, and is urged toward the rotating shaft 94a by a tension spring 100. As described above, the projecting unit 79 slides due to the rotation of the rotating plate 97, but the rotating plate 97 rotates in the direction of the arrow in FIG. When it reaches the position detected by 96b (the leftmost position in FIG. 54),
The stopper shaft 97c and the stopper member 99 are fitted, and the rotating plate 97
Is no longer rotated. For this reason, the protrusion unit 79 is fixed at the position where the protrusion unit 79 is completely protruded. Further, when returning the ejection unit 79 to the home position, the engagement between the stopper member 99 and the stopper shaft 97c is released by rotating the ejection motor 90 in the direction opposite to the direction of the ejection. Then, the projecting unit returns to the home position, and at the position detected by the home sensor 96a (the rightmost position in FIG. 54), as shown in FIG.
And the stopper member 99 are fitted so that the rotating plate 97 does not further rotate.

As described above, the projecting unit 79 is configured to move left and right by the forward / reverse rotation of the projecting motor 90.

{Distance between Nips of Folding Roller and Center of Abutting Plate} As described above, the movable roller 78b of the folding roller 78 moves upward according to the thickness of the sheet bundle P. That is, the distance between the nips of the folding roller 78 changes. 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 folding rollers 78, and the sheet bundle P may not be folded at the binding position.

Therefore, in this embodiment, even if the distance between the nips of the folding roller 78 is changed by the cam member, the pushing plate is not used.
79a is configured to always pierce the center between the nips. The configuration for that will be specifically described with reference to FIG.

As shown in FIG. 57, the projecting unit 79 is rotatable about a sliding roller 79g (the outer diameter of the sliding roller 79f is smaller than the width of the groove 89). A cam member 101 is attached to both shafts 78c and 78d. The cam member 101 is provided with a cam groove 101a engageable with the movable roller shaft 78d and a guide portion of the protrusion unit 79.
101b, and the projecting unit 79 is provided with the guide portion 101
b and is urged downward by a spring 102.

The cam member 101 is connected to the shaft 10 of the fixed roller 78a.
When the movable roller 78b rotates around the fulcrum 80a (see FIG. 53) and the movable roller 78b moves upward, the shaft 78d of the movable roller 78b is moved by a cam. Push up the groove 101a. As a result, the cam member 101 rotates in the counterclockwise direction in FIG. 57, 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 so that the pushing plate 79a always projects from the center of the nip distance of the folding roller 78.

By providing the cam member 101 as described above, even if the distance between the nips of the folding roller 78 changes due to a change in the thickness of the sheet bundle, the abutting position of the abutting plate 79a is aligned, and the distance between the nips is always maintained. By hitting the center, the sheet bundle P is reliably folded at the binding position. 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 and nipped by the folding roller 78. Even after the folding roller 78 nips the sheet bundle P, the pushing plate 79a is pushed by the projecting unit 79. If it is at the position, the inner sheet may be wrinkled due to the frictional force between the folded sheet and the pushing plate 79a.

Thus, in the present embodiment, as shown in FIG. 58, after the sheet bundle P is nipped by the folding roller 78, the pushing plate 79a is pulled back to the home position. If the timing of pulling back the pushing plate 79a is too early, the pushing plate 79a returns before the folding roller 78 nips the sheet bundle P. Therefore, in the present embodiment, a folding roller is used to fold the sheet bundle P.
It is configured such that the pushing plate 79a is pulled back when the 78 has rotated a predetermined amount.

Thus, at the time when the sheet bundle P is nip-conveyed to the folding roller 78, the pushing plate 79a is retracted to the home position.
Does not rub against the abutting plate 79a, thereby preventing the occurrence of wrinkles.

{Folding Operation} As described above, the center of the bound sheet bundle P is pushed by the pushing plate 79a, and the center portion of the sheet bundle P pushed by the pushing plate 79a is held by the folding roller 78. The sheet bundle P is folded while being conveyed.

On each of the sheets forming the sheet bundle, an image is recorded on the upstream half surface and the downstream half surface in the conveying direction with reference to the center of the sheet. Similarly, the image recording is performed on both sides of the sheet. The image recording is performed such that the sheet bundle subjected to the binding and folding processing is in the page order.

When an image is recorded at the center of the sheet bundle when the sheet bundle is pulled in by the folding roller as described above, the image (toner) lowers the sheet friction coefficient. The sheet cannot be reliably pulled in, and the sheet may be wrinkled or torn.

Here, the mechanism of sheet tearing and wrinkling during folding processing will be briefly described with reference to FIG. Here, a sheet bundle including two sheets P11 and P12 will be described as an example.

The frictional force between the folding roller 503 and the first sheet P11 is F1, the frictional force between the first sheet P11 and the second sheet P12 is F2, and the sheet bundle is bundled. Assuming that the binding force of the binding needle is F3, normally, F1 = F2 + F3
When the expression is established, normal folding processing is performed. However, in order to satisfy the above equation when the frictional force F2 between the sheets P11 and P12 decreases, the binding force F3 of the binding staple needs to be larger. At this time, even if the strength of the sheet can withstand the binding force F3 of the binding needle, the second sheet P12 is pulled by the binding needle, and FIG.
The displacement as shown in FIG. 59A occurs, and the deflection as shown in FIG. 59B occurs. Then, when the sheet passes through the folding roller 503 in this state, wrinkles as shown in FIG. 59 (c) occur. Further, when the strength of the sheet cannot withstand the binding force F3 of the binding staples, tearing occurs as shown in FIG. 59 (d).

Therefore, in the present embodiment, as shown in FIG. 60, a fixed margin portion (folding allowance t) is provided at the center portion of the sheet P (sheet bundle) serving as a folding portion. Specifically, the image recording on the sheet P to be processed by the stitcher unit D is performed in advance at the time of image recording in the image forming apparatus main body A, by inserting a margin t in advance in the sheet center portion.
(In the present embodiment, t = about 5 mm to about 8 mm, and the width of the margin is set to be about 2t = about 10 mm to 16 mm).

In the figure, Ps is the center (center in the transport direction) of the sheet P, and Pg is the image recording portion of the sheet P.

With this configuration, when the sheet bundle is pulled in by the folding roller 78, the frictional force between the sheet P and the folding roller 78 increases due to a margin (folding allowance t) provided in the sheet P in advance. Therefore, the sheet bundle P is reliably pulled in without causing wrinkles or tears as described above.

Here, 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, and if the width of the margin exceeds about 16 mm, the image forming area decreases. For this reason, the margin width is about 10 mm to 16 mm
It is desirable to set to.

In the present embodiment, the sheet to be folded is formed so as to form a margin with a predetermined width as described above, but it is necessary to increase the image forming area. In some cases, the setting of the margin may be configured to be releasable. In particular, when the number of folds is small, since there is little possibility that tearing will occur even if the margin of the fold is narrowed, the setting of providing the margin with the predetermined width is canceled, and the normal margin width (for example, about 4 mm) is released. ) 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), image recording is also performed on the back surface of the cover sheet (hereinafter referred to as a cover sheet). When fixing the toner image transferred to the back surface of the cover sheet by the fixing unit, silicon oil or the like adheres, and the coefficient of friction between the back surface of the cover sheet and the sheet in contact with the cover image decreases. Note that high-quality paper (and thick paper) is often used for the cover sheet. However, 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 and folded by a folding roller, and is attempted to be pulled in, slippage occurs between the sheets because the coefficient of friction between the back surface of the cover sheet and the sheet in contact therewith is small, and only the cover sheet is drawn in. There is a possibility that it will.

Therefore, in the present embodiment, no recording is performed on the back surface of the cover sheet in the cover mode. Specifically, at the time of image recording in the image forming apparatus main body A, after performing image recording 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 is discharged. I send it to D.

In this embodiment, since the cover sheet (such as high-quality paper) is fed from the multi-tray 8 (see FIG. 1), the last sheet to be sent to the stitcher unit D starts from the multi-tray 8. Re-sending path 7 for paper feeding
Is controlled so as not to pass through.

With this configuration, since the back surface of the cover sheet does not contact the fixing means (fixing roller on the image surface side), silicone oil does not adhere to the back surface of the cover sheet. A reduction in the coefficient of friction is prevented, and only the cover sheet is prevented from being pulled in.

{Sheet Bundle Detecting} Usually, when a break occurs in the sheet bundle during the folding process as described above, a configuration is conceivable in which this tear is detected by detecting means such as a sensor. Is provided separately, the number of parts increases and the cost increases. Further, when the tear is detected, the next sheet is conveyed, and there is a possibility that a more severe jam may occur because the previous sheet is staying.

Therefore, in the present embodiment, as shown in FIG. 61, an intermediate sensor provided near (upstream) the folding roller 78 is used.
103, a stopper sensor 75 provided on the stopper 62, and a discharge sensor 105 provided near the discharge roller 104, when each of the sensors detects the presence of a sheet at the same time,
The sheet (or sheet bundle) is configured to be torn and the stitcher unit D detects that the sheet (or sheet bundle) is staying.

In this embodiment, when the intermediate sensor 103, the stopper sensor 75, and the discharge sensor 105 detect the presence of a sheet at the same time, it is detected that a sheet is torn. 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 a sheet, it is also possible to detect that the sheet is torn.

With this configuration, there is no need to separately provide a detecting means for detecting that the sheet (or sheet bundle) has been torn, so that an increase in the number of parts and an increase in cost can be prevented. It becomes possible. Also,
Since the breakage of a 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} As described above, the sheet bundle that has been subjected to the folding process is loaded onto the stacking tray by the discharge roller 104.
It is discharged on 106 and loaded. As shown in FIG. 63, 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 a rotation shaft 107a. By the pressing member 107, when the folded sheet bundle P is discharged onto the stacking tray 106 from the discharge port by the discharge roller 104, the end of the sheet bundle P can be pressed. Even a sufficient sheet bundle P can be stacked so as not to open on the stacking tray 106.

The pressing member 107 has a rotating roller 107b provided at a tip end thereof having a predetermined height h (loading tray 106).
(A height at which the roller 107b does not come into contact with the rotary roller 107b), while allowing the rotary roller 107b to move freely in the lifting direction. Therefore, the ejection failure caused by the front end of the sheet bundle P having a weak waist being pressed by the pressing member 107 is eliminated, and the stacking tray 10
6 can be loaded.

As described above, when the folded sheet bundle P is discharged onto the stacking tray 106 by the discharge roller 104, the sheet bundle folding side (downstream in the discharge direction) is larger than the sheet bundle open side. However, if the sheets are stacked as they are, only the folded side of the sheet bundle becomes high, and the stackability of the sheet bundle may become unstable. Therefore, as shown in FIG. 62, the sheet bundle P discharged by the discharge roller 505 is
There is proposed an apparatus in which the sheet bundles P are sequentially shifted and discharged and stacked so that the sheets are stacked in a bale stack on the stacking tray 504.

However, in the above-described configuration, when a large number of sheet bundles are to be discharged, the stacking tray needs to be enlarged, and the apparatus becomes large, and the installation space also increases.

Accordingly, in this embodiment, as shown in FIG. 63, the portion of the stacking tray 106 near the discharge roller 104 is made higher than the stacking surface 106b (projection 106a), and the folding side of the sheet bundle P is The discharge is performed so that the open side is placed on the protrusion 106a on the loading surface 106b on the leading end side (downstream side in the discharge direction) of the 106. As a result, the fold side is lower than the open side, and even when the fold side is larger than the open side, the difference in height from the open side can be reduced.

More specifically, when the sheet bundle P is thick (that is, in the case of a sheet bundle whose fold side is particularly swollen), the discharge roller
The sheet bundle discharging speed by the sheet bundle 104 is reduced so that the open side of the sheet bundle P is discharged so as to be placed on the protrusion 106a.
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 discharge speed by the discharge roller 104 is increased, and the open side of the sheet bundle P does not rest on the protrusion 106a. As described above, the air 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. Further, since it is not necessary to stack the sheet bundle P in a bale, the stacking tray 106
Does not need to be increased.

Although the projections are provided in this embodiment, the present invention is not limited to this. For example, an inclined portion may be provided, or the stacking tray 106 may be provided in an inclined shape. A configuration may be employed in which a protruding portion that can be inserted into and removed from the bottom surface of the stacking tray 106 is provided.

{Explanation of Control System} Here, the configuration of the main part of the control system for controlling the driving of each member of the stitcher unit will be briefly described with reference to FIG.

Referring to FIG. 64, MPU 20 as a control means
0 denotes a first upper sensor 66a to a third upper sensor 66c for detecting the presence or absence or leading end or trailing end of the sheet conveyed to the stitcher unit, a matching member home sensor 220 for detecting the home position of the matching member 71, and a stopper 62. Stopper home sensor 76 and stopper 62 that detect the home position
, A stopper sensor 75 for detecting a sheet, a discharge sensor 105 provided near the discharge roller 104, and a pushing plate 79a.
Thrust position sensor 96b for detecting the thrust position of the
A signal from each sensor such as the intermediate sensor 103 provided near 78 is input.

Based on the signals from the sensors and the image forming apparatus main body A, the MPU 200
The first flapper solenoid 201 for driving the first flapper 21 for feeding the sheet to the vertical path of the stitcher unit through 20 to D28, the first flapper 64a and the second flapper 64b on the vertical path Switching upper solenoid 221 for switching, switching lower solenoid 222, upper roller pair
A conveying motor 223 for driving the 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 aligning member 71, and for moving the stopper 62. The stopper driving motor 74, the folding motor 82 for driving the folding roller 78, the ejection motor 90 for driving the ejection plate 79a, and the like are controlled to perform the above-described operations.

[0302]

The present invention is constructed as described above.
The back surface of the sheet serving as the cover does not contact the fixing roller of the image forming apparatus main body, and silicon oil or the like does not adhere to the back surface of the cover. Therefore, even if high-quality paper is used for the cover, the coefficient of friction does not decrease, and the cover does not break during folding.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating the entire configuration of an image forming apparatus.

FIG. 2 is an explanatory diagram of a cross-sectional configuration of a finisher unit.

FIG. 3 is an explanatory diagram of a cross-sectional configuration of a stitcher unit.

FIG. 4 is an explanatory perspective view illustrating a state of a sheet discharged by an offset process.

FIG. 5 is an explanatory diagram of a state of a sheet shifted by an offset process and a state of the discharged sheet.

FIG. 6 is a diagram illustrating a state in which a preceding sheet in a two-sheet discharge control is retained in a buffer path.

FIG. 7 is a diagram illustrating a state in which two sheets are simultaneously conveyed in the two-sheet discharge control.

FIG. 8 is a flowchart illustrating a timing of sending a discharge signal of a preceding sheet in the two-sheet discharge control.

FIG. 9 is a flowchart showing a timing of sending a discharge signal of a preceding sheet in the two-sheet discharge control according to the present invention.

FIG. 10 is a diagram illustrating a state of a sheet when the upper portion of the side guide is not used as a guide when discharging the sheet.

FIG. 11 is a diagram illustrating a state of a sheet when the upper portion of the side guide according to the present invention is used as a guide for discharging a sheet.

FIG. 12 is a diagram illustrating a state in which the side guide is retracted after the leading end of the sheet is nipped by the downstream discharge roller pair.

FIG. 13 is a sectional view of a main part showing a position of a stack tray.

FIG. 14 is an enlarged view of a main part showing a state of a swing guide and a paddle when the sheet is pulled back.

FIG. 15 is an enlarged view of a main part showing a state of a swing guide and a paddle when a sheet is pulled back.

FIG. 16 is a diagram showing an example of a paddle shape.

FIG. 17 is a diagram exemplifying the number of times of driving a paddle, the moving speed of a side guide, and alignment control according to a sheet size.

FIG. 18 is an explanatory diagram of a rear end stopper.

FIG. 19 is a diagram illustrating a standby position when the stapler functions as a rear end stopper.

FIG. 20 is a diagram illustrating a sheet width alignment state by a side guide.

FIG. 21 is a diagram illustrating a sheet width alignment state by a side guide.

FIG. 22 is a diagram illustrating a state of a knurled belt at the time of sheet width alignment by a side guide.

FIG. 23 is a diagram illustrating an example of a shape of a knurl belt.

FIG. 24 is a diagram illustrating a sheet width alignment state by a side guide.

FIG. 25 is an explanatory diagram illustrating an operation state of a drive mechanism of a swing guide and a downstream discharge roller.

FIG. 26 is an explanatory diagram illustrating an operation state of a drive mechanism of a swing guide and a downstream discharge roller.

FIG. 27 is an explanatory diagram illustrating an operation state of a drive mechanism of a swing guide and a downstream discharge roller.

FIG. 28 is a flowchart showing a flow of position control during the swing guide closing operation.

FIG. 29 is a flowchart showing a flow of an abnormal end process at the time of the swing guide closing operation.

FIG. 30 is a diagram illustrating low-speed drive control when the drive motor rotation direction is switched.

FIG. 31 is a diagram illustrating a binding operation according to the embodiment.

FIG. 32 is a diagram illustrating a stapler and a needle cartridge.

FIG. 33 is a flowchart illustrating a needle cartridge replacement process.

FIG. 34 is a flowchart illustrating a needle leading process.

FIG. 35 is a view for explaining conventional control when a needle jam occurs.

FIG. 36 is a diagram illustrating control when a needle jam occurs according to the present embodiment.

FIG. 37 is a diagram illustrating stapler initialization when the stapler door is opened and closed.

FIG. 38 is a diagram for explaining a rising speed of a discharge motor.

FIG. 39 is a diagram illustrating a state in which sheets are discharged to a stack tray, and a perspective view illustrating a schematic configuration of a main part of a tray unit.

FIG. 40 is a flowchart illustrating control at the time of full load detection.

FIG. 41 is a flowchart illustrating detection of full loading of a special sheet.

FIG. 42 is a block diagram schematically showing a control system of the finisher unit.

FIG. 43 is a partially enlarged view illustrating the configuration of a pickup roller.

FIG. 44 is a diagram illustrating the operation of the pickup roller.

FIG. 45 is a diagram illustrating the shape of a vertical path.

FIG. 46 is a diagram illustrating the shape of a stacked sheet.

FIG. 47 is a diagram illustrating a stopper driving mechanism.

FIG. 48 is an explanatory diagram of a configuration of a stapler unit.

FIG. 49 is an explanatory diagram of loading of a needle into a needle cartridge.

FIG. 50 is an explanatory diagram of a motor drive current waveform at the time of needle leading.

FIG. 51 is a diagram illustrating a state in which the needle fitted into the groove of the anvil is pulled out by the pickup roller.

FIG. 52 is a flowchart in a case where the amount of movement of the stopper to the binding stop position and the folding stop position can be automatically adjusted.

FIG. 53 is an explanatory diagram of a moving configuration of a movable roller.

FIG. 54 is an explanatory side view of a drive configuration of the folding unit.

FIG. 55 is an explanatory plan view of a drive configuration of the folding unit.

FIG. 56 is an explanatory diagram of a stopper structure of a pushing plate.

FIG. 57 is a configuration explanatory view of a cam member for centering a thrust plate.

FIG. 58 is an explanatory diagram of a state in which the pushing plate is pulled back.

FIG. 59 is an explanatory diagram showing a mechanism of occurrence of a sheet tear or a wrinkle during a folding process.

FIG. 60 is an explanatory diagram illustrating an image recording portion and a folding allowance portion on a sheet.

FIG. 61 is a layout diagram of an intermediate sensor, a stopper sensor, and a discharge sensor for detecting a sheet tear.

FIG. 62 is an explanatory diagram illustrating a state of bale stacking of a sheet bundle on a stacking tray.

FIG. 63 is an explanatory diagram illustrating a state in which a sheet bundle is stacked on a stacking tray.

FIG. 64 is a block diagram schematically showing a control system of the stitcher unit.

[Explanation of symbols]

 A: Image forming apparatus body B: Sheet processing apparatus C: Finisher unit D: Stitcher unit P: Sheet P1: Sheet P2: Previous sheet P3: Trailing sheet Pg: Image recording portion Ps: Center t: Insertion allowance 1: Original Feeding device 2 ... Optical means 3 ... Image forming means 3a ... Light irradiating means 3b ... Photoconductor drum 4 ... Sheet cassette 5 ... Convey roller 6 ... Fixing means 7 ... Resending path 8 ... Multi tray 11 ... Side guide 12 ... Staple tray 13 stapler 13a needle cartridge sensor 13b needle detection sensor 13c head needle detection sensor 14 buffer path 15 transport roller 16 upstream discharge roller pair 17 downstream discharge roller pair 17a downstream discharge roller 17b moving discharge roller 18 … Stack tray 19… Upper tray 20… Swing guide 20a… Swing axis 21… First flapper 22 2nd flapper 23… buffer roller 24… buffer roller 25… third flapper 26… buffer sensor 27… entry sensor 28… inlet sensor 29… discharge sensor 30… auxiliary guide 31… paddle 31a… tip 32 knurled belt 32a… edge Part 33… Rear end stopper 33a… Abutting surface 33b… Tapered part 34… Stopper 34a… Shutter part 35… Link 35a… Rotating shaft 36… Discharge port 37… Reference guide 38… Cover member 38a… Rib 39… Driving mechanism 40 … Drive motor 41… Pinion gear 42… Pendulum gear unit 42a… Fixed gear 42b… Swing gear 43… Discharge gear 44… Intermediate gear 45… Intermediate gear 46… Operation gear 46a… Gear 46b… Protrusion 46c… Missing gear Part 47… Opening / closing arm 48… Intermediate gear 49… Sensor flag 50… Needle cartridge 50a… Needle plate 51… Stapler door 52… Front cover 53… Stack cell C 54 ... distance measuring sensor 55 ... drive motor rotation detection sensor 56 ... encoder 57 ... tray frame 57a ... tray unit flag 58 ... tray unit 58a ... rack unit 59 ... finisher frame 60 ... vertical path 60a, 60b ... path guide 60a1 ... notch Hole 60b1 Guide surface 60c Raised portion 61 Stapler unit 61a Rotating shaft 61b Forming portion 61c Drive unit 61d Anvil 61d1 Surface 61d2 Groove 61e Needle cartridge 61f Binding needle 61g Spring 61h Needle feed roller 61i stapler motor 61j gear train 61k eccentric cam gear 62 stopper 62a slide member 62b flag 63 upper roller pair 64 flapper 64a first flapper 64b second flapper 65 movable guide 65a urging means 65b … Handle 66… seat sensor 66a… first upper sensor 66b… second upper Sensor 66c Third upper sensor 67 Lower roller pair 68 Drive roller 69 Pickup roller 69a Transport roller arm 69b Rotating shaft 69c Elastic member 70 Compression release arm 71 Alignment member 72 Stopper frame 73 Stopper drive Belt 73a Drive pulley 73b Idler pulley 73c Rotating shaft 73d Drive gear 74 Stopper drive motor 75 Stopper sensor 76 Stopper home sensor 77 Support plate 78 Fold roller 78a Fixed roller 78b Movable roller 78c, 78d … Shaft 79… Projecting unit 79a… Protruding plate 79b, 79d… Holder 79c, 79e… Shaft 79f, 79g… Sliding roller 80… Support arm 80a… Support point 81… Spring 82… Fold motor 82a… Output shaft 83… Motor pulley 84… Timing belt 85 ... Idler gear pulley 86, 87 ... Folding gear 88 ... Idler gear 89 ... Groove 90 ... Projection motor 90a … Motor pulley 91… Idler gear pulley 92… Timing belt 93… Shaft 94… Gear 94a… Rotating shafts 95a, 95b… Flag 96a… Home sensor 96b… Push position sensor 97… Rotating plate 97a… Shafts 97b, 97c… Stopper shaft 98 ... Link 99 ... Stopper member 99a ... Shaft 100 ... Tension spring 101 ... Cam member 101a ... Cam groove 101b ... Guide part 102 ... Spring 103 ... Intermediate sensor 104 ... Discharge roller 105 ... Discharge sensor 106 ... Loading tray 106a ... Protrusion Portion 106 b Loading surface 107 Pressing member 107 a Rotating shaft 107 b Rotating roller 200 MPU 201 First flapper solenoid 202 Second flapper solenoid 203 Third flapper solenoid 204 Buffer motor 205 Discharge motor 206 … Paddle solenoid 207… side guide motor 208… reference guide solenoid 209… stacker motor 210… stapler motor 211… stap Moving motor 212… Stapler home sensor 220… Alignment member home sensor 221… Changeover solenoid 222… Changeover solenoid 223… Transport motor 224… Width adjustment motor 225… Pinion gear 226… Encoder 227… Stacker motor clock sensor 228… Tray home position Sensor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seichiro Adachi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Mitsushige Murata 3-30-2 Shimomaruko, Ota-ku, Tokyo Non Corporation

Claims (4)

[Claims] An image forming apparatus for forming an image on a sheet, binding the image-formed sheet and folding the sheet in two, comprising: an image forming means main body having an image forming means for forming an image on a sheet; A sheet processing apparatus for binding a plurality of sheets on which images have been formed, and further folding the book in two, and for the cover sheet to be folded in two, forming an image only on the cover surface in the image forming apparatus body. An image forming apparatus configured to send the sheet to a sheet processing apparatus. 2. The image forming apparatus main body has a re-sending path for conveying a sheet on one surface of which is formed by the image forming unit to the image forming unit again in order to form images on both sides of the sheet. 2. The image forming apparatus according to claim 1, wherein the sheet to be fed is sent to a sheet processing apparatus without passing through the resending path. 3. The image forming apparatus according to claim 1, wherein the cover sheet is fed from a multi-tray. 4. The image forming apparatus according to claim 1, wherein the image forming unit transfers the toner image to a sheet, fixes the toner image by a fixing unit, and records the image.