JP2834621B2 - Sheet post-processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an image forming apparatus such as a copying machine, a laser beam printer, or the like, and performs post-processing on a sheet carried in from these apparatuses and discharges the sheet onto a discharge tray. It relates to a post-processing device.

[0002]

2. Description of the Related Art In recent years, copying machines have been used in combination with an automatic document feeder and a post-processing device for automating a copying operation and stapling or punching a copied sheet. ing. The automatic document feeder is provided on a document table of a copying machine, and sequentially transports a plurality of documents to a document table of the copying machine. The post-processing apparatus performs post-processing such as stapling or punching for a predetermined number of sheets on the copied sheets discharged from the copying machine.

A conventional post-processing apparatus, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-144370, stacks sheets discharged from a copying machine on a processing tray, staples them with a stapler, and then moves the sheets up and down. The sheet is discharged to a discharge tray on the upper end side of the processing tray by a pair of discharge rollers. Further, in this type of post-processing apparatus, there is a type in which a post-processed sheet is pushed out by a pusher provided at a lower end side of a processing tray.

[0004]

In a conventional post-processing apparatus, in order to quickly discharge a sheet after stapling, the sheet is discharged by a pusher or a discharge roller so as to fly out toward a discharge tray. The sheet discharging speed is constant regardless of the size of the sheet. For this reason, the amount of protrusion to the discharge tray varies depending on the size of the sheet, and there is a problem in the stacking property to the discharge tray.

[0005] When the sheet discharging speed is low, B4,
As shown in FIG. 19, the sheet S having a large size such as A3 is bent or bent due to its leading edge being gripped by friction with the discharge tray T. When the sheet discharge speed is high, for the small-sized sheets S such as B5 and A4, FIG.
It jumps out as far as 0. For this reason, it has been difficult to smoothly discharge sheets of all sizes at a constant discharge speed.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a sheet post-processing apparatus that varies a sheet discharging speed according to a sheet size.

[0007]

According to a first aspect of the present invention, there is provided a control unit for controlling the driving of a discharge unit in accordance with the size of a sheet.
When the sheet S has a large size of B4 or more , the discharging unit 5
1 is provided with a large sheet discharging means for increasing the discharging speed of the sheet S, and a small sheet discharging means for lowering the discharging speed of the sheet S by the discharging unit 51 when the sheet S has a small size of A4 or less .

[0008] The means for solving the problem according to claim 2 is the sheet S
Control unit 7 that controls the driving of discharge unit 51 according to the size of
0 is provided to the control unit 70, and a large sheet discharging means sheet S is to increase the discharging speed of the sheet S by the discharge unit 51 when the large size or B4, the sheet S is A4 or less
A discharge speed changing means for switching the discharge speed of the sheet S by the discharge unit 51 from a high speed to a low speed during discharge when the size is small below .

According to a third aspect of the present invention, the sheet S
Discharge unit 5 according to the size of the sheet and the number of sheets after the post-processing.
A control unit 80 for controlling the driving of the control unit 8 is provided.
0, a large number of large sheets discharging means for slowing down the discharging speed of the sheet S by the discharging section 51 when the size of the sheet S is larger than B4 and the number of sheets is large,
Sheet S by the discharge unit 51 when the number of sheets is small
And large sheet small number discharging means to increase the discharge speed of the miniature sheet number of sheets discharging means sheet S is to increase the discharging speed of the sheet S by the discharge unit 51 when the number is large in small size A4 or less, the sheet S is Small size less than A4
When the number of sheets is small, the discharging speed of the sheet S by the discharging unit 51
And means for discharging a small number of small sheets for reducing the degree .

[0010]

According to the first aspect of the present invention, the sheet S on the sheet receiving table 46 is subjected to post-processing by the post-processing section 45. Then, the large-sized sheets S of A3 and B4 are discharged to the discharge tray 56 at a high speed so that the leading end does not bend due to friction with the discharge tray 56. Also, a sheet S having a small size of A4 and B5
Is discharged at a slow speed so that it does not fly out. For this reason, the stacking property is improved.

According to the second aspect of the present invention, the small-sized sheet S after the post-processing is first discharged at a high speed and then discharged to the discharge tray 56 at a low speed from the middle. The sheet S, while ensuring the stacking property,
The sheets are stacked on the discharge tray 56. For this reason, the discharge time of the small-sized sheet S can be reduced.

According to the third aspect of the present invention, a large number of large-sized sheets S after the post-processing are discharged to the discharge tray 56 at a low speed. At this time, since the large sheets S are many, the leading end of the sheets S does not bend due to friction with the discharge tray 56. In addition, many small-sized sheets S after the post-processing are discharged to the discharge tray 56 at a high speed. At this time, the small sheet S
However, because it is a large number, it does not jump out far away with its weight.

[0013]

【Example】

<First Embodiment> FIG. 1 is a configuration diagram of a sheet post-processing apparatus, and FIG.
Is a configuration diagram of a copier equipped with a sheet post-processing apparatus, FIG. 3 is an arrangement diagram of each sheet detection switch in an offset mode of the sheet post-processing apparatus, and FIG. 4 is an arrangement of each sheet detection switch in a staple mode of the sheet post-processing apparatus. Figure,
FIG. 5 is a diagram showing a driving state of the pulse motor at the time of discharging a large sheet in the first embodiment, FIG. 6 is a diagram showing a driving state of the pulse motor at the time of discharging a small sheet in the first embodiment, and FIG. 8 is a flowchart showing the operation process of the post-processing device in the offset mode, FIG. 8 is a flowchart showing the operation process of the sheet post-processing device in the staple (single) mode, and FIGS. 9 to 13 are staples of the sheet post-processing device. 6 is a flowchart illustrating an operation process in a multi-mode.

First, a general copier equipped with a post-processing device will be described. As shown in FIG. 2, the copying machine has a copying machine main body 1 for copying an image of a document M onto a sheet S, and is formed on an upper end portion of the copying machine main body 1 at an upper portion of the copying machine main body 1. Document transport device 30 that transports document M to exposed section 2
Is provided.

The copying machine main body 1 has an exposure section 2
An exposure system 3 comprising a light source lamp 4, mirrors 5, 6, 7 and a lens 8 is disposed below the exposure system 3.
Performs optical scanning on the original M conveyed to the exposure unit 2 by the original conveying device 30 using irradiation light from the light source lamp 4 and reflects the reflected light to each of the mirrors 5, 6, 7 and the lens 8.
Irradiation is performed on the exposure point A on the surface of the photoconductor drum 10 through the interface, so that an electrostatic latent image corresponding to the image of the document M is formed on the surface of the photoconductor drum 10.

Around the photosensitive drum 10, a main charger 11 for charging the surface of the photosensitive drum 10 to a predetermined potential, a developing device 12, and a transfer charger 13
And a peeling charger 14, and the electrostatic latent image formed on the surface of the photosensitive drum 10 is
The toner image is transferred to the sheet S by the transfer charger 13, and then the transferred sheet S is peeled off from the photosensitive drum 10 by the peeling charger 14.

A sheet conveying path 15 for conveying a sheet S for transferring a toner image is provided below the photosensitive drum 10. On the upstream side of the sheet conveying path 15, a sheet feeding table 19 provided with each of the sheet feeding rollers 16, 17, and 18, a sheet feeding cassette 20, and a sheet feeding deck 21 are respectively disposed. The sheets S placed or accommodated therein are fed to the photosensitive drum 10 through the sheet conveying path 15. On the other hand, on the downstream side of the sheet conveying path 15,
Conveyor belt 2 that conveys sheet S to which the toner image has been transferred
2 and a fixing device 23 for fixing the toner image on the sheet S are provided.

Downstream of the fixing device 23, a deflector 24 is provided which branches the sheet S in the conveying direction to a sheet post-processing device 40 and a re-conveying path 25. The re-conveying path 25 forms a circulation path for conveying the sheet S on which the toner image has been transferred by the photosensitive drum 10 to the photosensitive drum 10 again. It enables double-sided copying.

The document transport device 30 has a document transport path 31 for transporting the document M to the exposure unit 2 formed on the upper end surface of the copying machine main body 1. The document conveying path 31 forms a circulation path. In the path, a document tray 32 for stacking the documents M and a document M stacked on the document tray 32 are sequentially supplied to the exposure unit 2. Feeding belt 33 to feed
And a transport belt 34 that is provided in contact with the exposure glass 3 forming the exposure unit 2 and forms a transport path for the original M with the exposure glass 3.

The document feeder 30 feeds the document M on the document tray 32 to the exposure unit 2 by the feed belt 33, and exposes the exposure glass 3 by the feed belt 34.
By positioning the document M at the upper predetermined position, the document M is arranged in a state where light scanning by the light source lamp 4 is possible.

Further, a sheet conveying path 15 in the copying machine main body 1 is provided.
A sheet post-processing device 40 for performing a stapling operation on a copied sheet is connected to the downstream side of the sheet.

As shown in FIG. 1, the sheet post-processing apparatus 40 aligns the sheet S with the post-processing conveyance path 41 for conveying the sheet S conveyed from the copying machine main body 1 in the post-processing apparatus main body 40a. A post-processing unit 45 for performing a bookbinding process using staples;
The sheet discharge unit 51 includes a sheet discharge unit 51 that discharges the sheet S from the inside of the printer 1 and a discharge tray 56 that stacks the sheets S discharged by the sheet discharge unit 51.

As shown in FIGS. 3 and 4, the post-processing conveyance path 41 is formed at one end thereof with a carry-in port 41a for carrying the sheet S conveyed from the copying machine body 1. The path branches bifurcated in the middle of the path to form a two-stage upper and lower bypass 41b and a main path 41c. A pair of upper and lower transport rollers 42 and 43 are disposed at each end. The branch point of the bypass 41b and the main path 41c is, B ₁ over B ₂ deflector 44 as the direction rotatable path switching means is provided, the bypass 41b the transport path of the sheet S or the main path 41c, any Or one of the paths.

Further, the post-processing conveyance path 41 is provided with sheet detection switches SW ₁ and SW ₂ for detecting the sheet S in the middle of each of the bypass 41b and the main path 41c.

As shown in FIG. 1, the post-processing section 45 includes a width-shifting plate 47 for aligning the sheets S accumulated in the sheet receiving table 46 from the post-processing conveyance path 41 in the width direction. It is composed of a paddle 48 to be aligned and a stapler 49 for binding and binding the sheets S with staples.

The sheet receiving table 46 is disposed below the post-processing conveyance path 41 with one end thereof being disposed near the discharge port 40b and the other end thereof being inclined lower than the one end. I have. Also, in the center of the side of the sheet receiving base 46,
A reference guide 47a for positioning the side of the sheet S is attached, and a stopper 50 for positioning the lower end of the sheet S is attached to the lower end of the sheet receiving base 46.

The width shift plate 47 is provided with the reference guide 47a.
Are arranged so as to be able to advance and retreat in the width direction of the sheet S. The paddle 48 includes a post-processing device main body 40a.
Are supported rotatably in the C direction, and their blades are in contact with the upper surface on the lower end side of the sheet receiving base 46. The stapler 49 is disposed on the lower side of the sheet receiving base 46 on the side of the paddle 48.

The sheet discharging section 51 includes a sheet receiving table 46 as a discharging path, an extruding means 52 disposed to be able to advance and retreat along the sheet receiving table 46 and extruding the sheet S, and a discharge section of the post-processing apparatus main body 40a. And discharge rollers 53 and 54 disposed near the outlet 40b.

The pushing means 52 is provided with the stopper 50
It consists from the rear and a pair of pushing piece 52a which is a retractable to D ₁ -D ₂ directions, a drive unit which is arranged below the seat pedestal 46 to drive the pushing piece 52a.

The extruded piece 52a has a flat plate shape and is guided by the elongated hole of the sheet receiving base 46 when driven. The driving unit is attached to the base of the pushing piece 52a and a pair of rollers 5
An endless belt 52c wound around 2b and a pulse motor 52d for rotating one roller 52b via a gear or the like. The pulse motor 52d is provided separately from a driving unit (motor) of another component.

The discharge roller 53 has a rotating shaft 53a.
Are rotatably mounted on the upper end of the sheet receiving base 46 so as to be rotatable. On the other hand, the discharge roller 54 has a rotation shaft 54 a pivotally supported at one end of an arm member 55, and the other end of the arm member 55 has F ₁ around a fulcrum E.
And it is rotatable in the -F ₂ directions.

[0032] Then, discharge rollers 53, the staple mode, while assisting the alignment of the conveying direction of the sheet S to be stacked on the sheet receiving tray 46 by the rotation of the G ₂ direction by the rotation of the G ₁ direction The bound sheet S is discharged to the discharge tray 56.

Further, the discharge roller 54 is offset mode, in accordance with the rotation of the G ₁ direction of the discharge roller 53,
By the arm member 55 is rotated in the F ₂ direction, sandwiching the sheet S between the discharge roller 53 to discharge the sheet directly S onto the discharge tray 56 from the post-processing transport path 41.

[0034] Note that the discharge roller 54, the sheet detection switch SW ₃ is disposed, the sheet detection switch SW
₃ detects the sheet S when the discharge rollers 53 and 54 abut in the offset mode as shown in FIG.

The discharge tray 56 is attached to the post-processing apparatus main body 40a below the discharge roller 53, and is vertically moved by an elevator unit 57 and a shift unit 58 disposed near the attachment portion. and it is movable in the direction perpendicular to the ₁ -H ₂ direction to the discharge direction. Then, the sheet S of the uppermost bound already discharge tray 56 by these movements are always discharging rollers 53 keeping a certain distance, the bookbinding already sheet S is adjusted tray position to overlap displaced alternately.

A control unit 59 comprising a microcomputer for controlling the post-processing device 40 is provided. The control unit 59 sequentially performs the post-processing on the sheets S conveyed from the copying machine main body 1 without performing post-processing. An offset mode for discharging the sheets S one by one to the discharge tray 56, and a staple for discharging the sheet S conveyed from the copying machine main body 1 to the discharge tray 56 after performing a post-binding process on the sheets S conveyed from the copying machine main body 1; A (single) mode and a staple (multi) mode in which sheets S conveyed from the copying machine body 1 are subjected to post-binding processing and then a plurality of sets of bound sheets S are sequentially discharged to the discharge tray 56 are executed. A program is stored.

The control section 59 executes each mode in response to a detection signal of each sheet S from the sheet detection switches SW ₁ , SW ₂ , SW ₃ and a sheet detection switch (not shown) provided on the sheet receiving base 46. I do. The control section 59 also controls the copying machine main body 1 , and the rotation operation of the transport roller 43 is temporally controlled by a timer (not shown).

Further, the control unit 59 has a function for detecting the size of the sheet S by the time the sheet detection time switch SW ₁ is turned on or the sheet detection switch SW ₂ is turned on, the sensed sheet S It has a function of controlling the driving of the pulse motor 52d of the pushing means 52 according to the size. That is, when the sheet S has a large size such as A3 or B4, as shown in FIG.
Large sheet discharging means for increasing the number of output pulses to the sheet S to increase the speed of discharging the sheet S by the extruded piece 52a, and when the sheet has a small size such as A4, B5, etc., as shown in FIG. Reduce the number of extruded pieces 5
2a, a small sheet discharging means for reducing the sheet discharging speed according to 2a.

In the above configuration, in the offset mode, as shown in the flowchart of FIG. 7, when the offset number is input, the control section 59 receives the offset number (S1) and sets the offset number (S2). Next, when the post-processing device 40 receives a start signal from the control unit 59 (S3), start processing in the offset mode is performed (S4), and the number of processed sheets is cleared (S4).
5).

The sheet S on which the image of the original M has been copied by the copying machine main body 1 passes through the carry-in port 41a, and the post-processing apparatus main body 4
It is carried into 0a, and when passing through the main path 41c sheet detection switch SW ₂ is turned on (S6), the main path 41c
Is detected. Then, each discharge roller 53,5
When passing between the 4 sheet detection switch SW ₃ is turned on (S7), the sheet detection switch SW ₃ when it is discharged to the discharge tray 56 is turned off (S8), the process number is counted up (S9).

Next, it is determined whether or not the number of processed sheets counted up as described above matches the number of offset sheets (S10). If the number of processed sheets does not match the number of offset sheets, the process returns to S6, and the conveyance of the sheet S in the main path 41c is detected. If the processed number matches the offset number, the processed number is cleared (S11).
Lowering of the discharge tray 56 (S12), offset (S1)
3) and ascending (S14) are sequentially performed.

When the copying is completed, the control unit 59
Outputs a copy end signal (S15), and when the post-processing device 40 receives the end signal, end processing is performed (S16), and the offset mode as described above is ended. If the copy has not been completed, the post-processing device 40 does not receive the end signal and returns to S6 again.

Next, in the staple (single) mode, as shown in the flowchart of FIG. 8, when the number of staples is input, the control section 59 receives the number of staples (S21) and sets the number of staples (S22).
Next, when the post-processing device 40 receives a start signal from the control unit 59 (S23), a start process in the staple (single) mode is performed (S24), and the number of processed sheets is cleared (S25).

Thereafter, the sheet S on which the image of the original M has been copied by the copying machine body 1 is carried into the post-processing apparatus body 40a through the carry-in port 41a, and passes through the main path 41c.

[0045] At this time, the main path 4 by ON (S26) and off the sheet detection switch SW ₂ (S27)
The size of the sheet S is detected based on the time of conveyance and ON in 1c, and the sheet S is discharged onto the sheet receiving table 46 by the discharge roller 43. As a result, the timer of the post-processing device 40 is cleared and the timer starts (S28), and the number of processed sheets is counted up (S29). When the predetermined time has elapsed (S30), it is determined that the discharge of the sheet S onto the sheet receiving table 46 is completed, and the sheet S on the sheet receiving table 46 is aligned in the width direction by the width shift plate 47 (S31). .

Next, it is determined whether or not the number of processed sheets counted up as described above matches the number of staples (S32). If the number of processed sheets does not match the number of staples, the process returns to S26, and the main path 41 of the sheet S is returned.
The conveyance at c is detected. If the number of processed sheets matches the number of staples, the number of processed sheets is cleared (S33).
Rotation in the direction, and its lower end portion by rotation of the G ₂ direction of the discharge roller 53 are aligned in the conveying direction abuts against the stopper 50, the staple processing stapled by staple of the stapler 49 is performed (S34 ).

The bookbinding sheet S stapling as described above has been performed, pushing piece 52a of the pushing means 52 at its lower end abuts, is pushed out by the movement of the D ₁ direction of the pushing piece 52a.

At this time, a drive pattern corresponding to the size of the sheet S is selected from the preset drive pattern of the pulse motor 52d to drive the pulse motor 52d.
The discharge speed of the sheet S by the extruded piece 52a is set.

Large-size bound sheets S such as A3 and B4 are discharged at a high speed, and small bound sheets S such as A4 and B5 are discharged at a low speed. Further, by the rotation of the G ₁ direction of the discharge roller 53 to fit thereto, bookbinding the sheet S is discharged to the discharge tray 56 (S3
5).

After the adjustment of the discharge tray 56 (S36), when the post-processing device 40 receives a copy end signal from the control section 59 (S37), the post-processing device 40 performs an end process (S38). The staple (single) mode is terminated.

Next, in the staple (multi) mode, as shown in the flow charts of FIGS. 9 to 13, when the number of staples is input, the control unit 59 receives the number of staples (S41) and sets the number of staples (S4).
2). Next, when the post-processing device 40 receives the start signal from the control unit 59 (S43), the stapling (multi) is performed.
The start processing in the mode is performed (S44), and the number of processed sheets is cleared (S45).

[0052] Thereafter, the sheet S on which the image of the document M is copied by the copying machine main body 1 passes through the entrance 41a is carried to the post-processing apparatus main body 40a, a sheet detection switch SW ₂ when passing through the main path 41c On (S46), conveyance on the main path 41c is detected. Then, the sheet detection switch SW ₂ is whether it is turned off is determined (S4
7). If the sheet detection switch SW _{2 is} still on,
As shown in FIG. 10, it is determined whether or not the bookbinding sheet S has been discharged from the sheet receiving table 46 (S48).

The bookbinding sheet S is still placed on the sheet tray 46.
But if not discharged, bookbinding sheet S is pushed by the movement of the discharge rate is set according to the size the D ₁ direction pushing piece 52a. Rotation of the G ₁ direction of the discharge roller 53 to fit thereto, bookbinding sheet S is discharged to a discharge tray 56 (S49), the flow returns to S47 again for the loading of the next sheet S.

If the bookbinding sheet S has been discharged from the sheet receiving table 46, it is determined whether or not the discharge tray 56 has been adjusted (S50). If the discharge tray 56 has been adjusted, the process directly returns to S47. If the discharge tray 56 has not been adjusted, the discharge tray 56 is adjusted (S51).
It returns to S47.

[0055] Then, when the off-sheet detection switch SW ₂ is detected, the size of the sheet S is detected, the timer of the post-processing apparatus 40 is cleared (S52), also,
The number of processed sheets S is counted up (S5).
3).

Next, it is determined whether or not the number of processed sheets counted up as described above is the first one (S5).
4). If the number of processed sheets is not the first sheet, the discharge roller 43
As a result, the sheet S is discharged to the sheet receiving table 46, and the process proceeds to S66 described later. If the number of processed sheets is the first sheet, it is determined whether or not the preparation of the sheet receiving tray 46 is OK (S).
55).

When the sheet tray 46 is ready, the sheet S is discharged by the discharge roller 43 to the sheet tray 4.
6 and the process proceeds to S66. If the sheet receiving table 46 is not ready, the conveyance of the first sheet S is stopped by stopping the rotation of the discharge roller 43 (S5).
6), also the deflector 44 is rotated in the B ₁ direction,
The conveyance path of the sheet S is switched to the bypass 41b (S57).

Next, whether or not the second sheet S is being conveyed to the bypass 41b is determined by the sheet detection switch SW.
It is determined by detecting the ON of ₁ (S58). If not the sheet detection switch SW ₁ is still on, as shown in FIG. 11, the bookbinding sheet S is whether already discharged from the sheet receiving tray 46 is determined (S59).

The bookbinding sheet S is still placed on the sheet receiving table 46.
Is not discharged, the bookbinding sheet S is discharged to the discharge tray 56 by the pushing means 52 and the discharge roller 53 according to the size of the sheet S as described above (S60), and the process returns to S58 again. From the sheet tray 46, the bound sheet S
Is discharged, it is determined whether or not the discharge tray 56 has been adjusted (S61). If the discharge tray 56 has been adjusted, the process directly returns to S58. If the discharge tray 56 has not been adjusted, the discharge tray 56 is adjusted (S6).
2) Return to S58.

[0060] The sheet S is turned on and the sheet detection switch SW ₁ is as it passes through the bypass 41b, the sheet S is past, the sheet detection switch SW ₁ is turned off.
(S63), the sheet detection switch SW ₁ from on to that time are sensed size of the sheet S, is rotated deflector 44 in the B ₂ direction transport path of the sheet S is switched to the main path 41c (S64 Also, the conveyance roller 43 is rotated, and conveyance of the first sheet S in the main path 41c is restarted (S65). At this time,
The second sheet S conveyed to the bypass 41b is discharged by the discharge roller 42, and the first sheet S and the second sheet S are simultaneously discharged onto the sheet receiving table 46.

Next, returning to S52, the post-processing device 40
Is cleared (S52), the number of processed sheets is counted up (S53), and if it is determined that the processed number is not the first sheet (S54), the sheet S is discharged by the discharge roller 43 to the sheet receiving tray. Is discharged to 46, FIG.
It is determined whether the predetermined time set by the timer has elapsed (S66). When the predetermined time has elapsed, the sheets S on the sheet receiving table 46 are aligned in the width direction by the width shift plate 47 (S67). Thereafter, it is determined whether or not the number of processed sheets S matches the number of staples. (S68).

If the number of processed sheets does not match the number of staples, the process returns to step S46 to detect the conveyance of the sheet S on the main path 41c. On the other hand, if the processed number matches the staple number, the processed number is cleared (S69).
Then, the sheet S on the sheet receiving tray 46 is rotated in the C direction of the paddler 48, and the lower end portion of the sheet S by the rotation of the G ₂ direction of the discharge roller 53 are aligned in the conveying direction abuts against the stopper 50 At the same time, the sheets are stapled by the staples of the stapler 49 and subjected to stapling processing (S70), and thereafter, the flow returns to S46 again to detect the conveyance of the sheet S on the main path 41c.

[0063] When the detection of the sheet S by the sheet detection switch SW ₂ is eliminated, as shown in FIG. 13, whether bookbinding sheet S is present at the already discharged is determined (S71).
If the bound sheet S has not yet been discharged from the sheet receiving table 46, the bound sheet S is discharged to the discharge tray 56 by the pushing means 52 and the discharge roller 53 according to the size of the sheet S as described above (S72). It returns to S46 again. If the bookbinding sheet S has been discharged from the sheet receiving table 46, it is determined whether or not the discharge tray 56 has been adjusted (S73).

If the ejection tray 56 has not been adjusted, the ejection tray 56 is adjusted (S74), and the process returns to S46.
If the discharge tray 56 has been adjusted, it is determined whether the post-processing device 40 has received a copy end signal from the control unit 59 (S75).

If the end signal has not been received, S
Return to 46. When the end signal is received, the end processing is performed (S76), and the staple (multi) as described above is performed.
The mode is terminated.

Further, the sheet post-processing device 40 of the present embodiment
So the staple (multi) mode, if there is no detection of the on-sheet detection switch SW ₁ (S58) is in the from the timer cleared (S52) a predetermined time by automatically restarting the rotation of the conveying roller 43, Only the first sheet S is discharged onto the sheet receiving table 46 without waiting for the simultaneous discharge with the second sheet S.

As described above, when performing bookbinding of a plurality of sets, the sheet post-processing apparatus 40 performs a predetermined bookbinding process on the first set of sheets S on the sheet receiving base 46 while the copier main body 1 is being processed. the sheet S ₁ of the next first sheet conveyed from the side and conveyed by the main path 41c, then, by stopping the rotation of the transport roller 43 temporarily stops the conveyance of the sheet S _1. Then, by switching the deflector 44, to convey the second sheet S ₂ to the bypass 41b.

When the bookbinding process and discharge of the first copy are completed, the rotation of the conveying roller 43 is resumed, thereby
The conveyance of the _first sheet S ₁ is resumed, and the sheet
Synchronization with discharging the first sheet S ₁ and a second sheet S ₂ above. Therefore, the sheet S on the sheet receiving table 46 is
Since the next sheet S is effectively conveyed even at the time of stapling, the speed of the post-processing operation can be increased.

The bookbinding sheet S on the sheet receiving table 46 is
When the sheet S has a large size of A3 and B4, the discharge speed is increased so that the bound sheet S can be discharged without being bent due to friction with the discharge tray 56. Further, when the sheet S has a small size of A4 and B5, the discharging speed is slowed down, so that the bound sheet S does not fly out. For this reason, the bound sheet S is placed in the discharge tray 56.
The stacking is carried out at a position corresponding to the size, thereby improving the stacking property.

<Second Embodiment> FIG. 14 is a diagram showing a driving state of a pulse motor at the time of discharging a small sheet in the second embodiment. The members having the same functions as in the first embodiment are denoted by the same reference numerals, and the configuration and operation similar to those in the first embodiment are omitted.

The control section 7 of the sheet post-processing apparatus according to the second embodiment.
0, the sheet detection switch and a function for detecting the size of the sheet S by the time the SW ₁ is turned on to have time or the sheet detection switch SW ₂ is turned on, pushing means 52 in accordance with the size of the sensed sheet S Has a function of controlling the driving of the pulse motor 52d.

That is, when the control section 70 has a large sheet discharging means and the sheet S has a small size such as A4 or B5, the number of output pulses to the pulse motor 52d is switched as shown in FIG. Discharging speed changing means for switching the sheet discharging speed from a high speed to a low speed and discharging the sheet.

For this reason, a small-sized bookbinding sheet S
Is initially discharged at a high speed by the extruded piece 52a,
It is discharged at a slow speed from the middle.

[0074] For example, as shown in FIG. 5, when discharging the booklet sheet S large size at a high speed v _1, it is discharged from the sheet receiving tray 46 at a distance l ₁ apart discharge tray 56 from the discharge start after t _1. However, as shown in FIG. 6, when discharged at a slower rate v ₂ so as not to jump out far bookbinding sheet S of small size, it is discharged to the discharge tray 56 Distance l ₂ away from the sheet receiving tray 46 after t ₂ from the discharge start You.

That is, t ₁ = l ₁ / v ₁ and t ₂ = l ₂ / v ₂
And v ₁ > v ₂ , so that t ₁ <t ₂ . At this time, if the discharge time of the small-sized bookbinding sheet S is reduced, the operation can be speeded up.

[0076] Therefore, in the second embodiment, the bookbinding sheet S of small size, as shown in FIG. 14, is discharged at a faster rate v ₃ First, is switched from the middle to the slower rate v ₄ after t ₃ has elapsed Is discharged. Here, since the discharge time t ₃ of the small-sized bookbinding sheet S is shorter than t ₂ , the discharge time is shortened, and the stacking property is secured as in the case of discharging at a low speed. 5
6 is loaded.

Therefore, it is possible to shorten the time required for discharging the small-sized bookbinding sheet S while securing the stacking property to the discharge tray 56, and it is possible to speed up the post-processing work.

<Third Embodiment> FIG. 15 is a view showing a driving state of a pulse motor when 50 sheets of A3 size are discharged in the third embodiment, and FIG. 16 is a view showing A in the third embodiment.
FIG. 17 is a diagram showing a driving state of the pulse motor when discharging 50 sheets of 4 sizes, and FIG. 17 is a diagram showing a driving state of the pulse motor when discharging 2 sheets of A3 size in the third embodiment. FIG. 9 is a diagram illustrating a driving state of a pulse motor when two A4 size sheets are discharged in the third embodiment.

The members having the same functions as in the first embodiment are denoted by the same reference numerals, and the configuration and operation similar to those in the first embodiment are omitted.

The control section 8 of the sheet post-processing apparatus according to the third embodiment.
0, a function for detecting the size of the sheet S by the time the sheet detection time switch SW ₁ is turned on or the sheet detection switch SW ₂ is turned on, depending on the size and staple number of detected sheets S Extrusion means 5
And a function of controlling the driving patterns of the second pulse motor 52 d.

That is, when the control section 80 has a large number of sheets S such as 50 sheets of a large size such as A3,
As shown in FIG. 15, a large number of large-sheet discharging means for reducing the number of output pulses to the pulse motor 52d to reduce the discharging speed of the sheet S, and a sheet S having a small size of A4 or the like.
As shown in FIG. 16, when there are a large number of sheets, such as zero, a large number of small sheet discharging means for increasing the number of output pulses to the pulse motor 52d to increase the discharging speed of the sheet S is provided.

For this reason, the bookbinding sheet S obtained by stapling a large number of large sheets S is discharged at a low speed by the extruded pieces 52a, and the bookbinding sheet S obtained by stapling a large number of small sheets S is an extruded piece. 52a
Is discharged at a faster rate.

In the case of discharging a bookbinding sheet S composed of a small number of large sheets S such as two sheets, the leading end of the bookbinding sheet S is not bent by friction with the discharge tray 56.
As shown in FIG. 17, it is necessary to increase the number of output pulses to the pulse motor 52d to increase the discharge speed. However, when a large number of sheets S are used, the sheet S does not bend with a little friction, and the stacking property is secured. The discharging speed can be slowed down.

Also, as few as two small sheets S
In the case of discharging the bookbinding sheet S composed of the following, it is necessary to reduce the number of output pulses of the pulse motor 52d and to reduce the discharging speed as shown in FIG. Since the sheets become heavier, the discharging speed can be increased while ensuring the stacking property.

As described above, since the bookbinding sheet S composed of a large number of large sheets S is discharged slowly while ensuring the stacking property, the driving energy of the pulse motor 52d can be suppressed, and the pulse motor 52d can be downsized. .
Furthermore, since the bookbinding sheet S including a large number of small sheets S is quickly discharged while securing the stacking property, the speed of the post-processing operation can be increased.

Note that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention.

For example, the size of the sheet S may be detected by the control units 59, 70, and 80 by detecting a sheet S size signal input in advance. The large sheet and the small sheet are conceptual ones, and the control amount may be varied according to the size of the sheet for more precise control.

[0088]

As is apparent from the above description, according to the first aspect of the present invention, since the discharging speed of a small-sized sheet is reduced, the sheet does not fly out. Further, since the discharging speed of the large-sized sheet is increased, the leading end does not bend due to friction with the discharging tray. For this reason, the stackability of sheets to the discharge tray is improved as compared with the conventional method of discharging sheets at a constant speed regardless of the size.

According to the second aspect, the small-size sheet is discharged at a high speed at first, and then discharged at a low speed from the middle, so that the stacking property to the discharge tray is improved and the discharge time can be reduced. . Therefore, the speed of the post-processing operation can be increased.

According to the third aspect, since the discharge speed of a large number of large-sized sheets is reduced, the leading end of the sheet does not bend due to the friction of the discharge tray, and the driving of the discharge unit is performed while improving the stacking property to the discharge tray. Energy can be suppressed. Further, since a large number of small-sized sheets are discharged at a high speed, the sheets do not fly out far, and the post-processing work can be sped up while improving the stacking property to the discharge tray.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a sheet post-processing apparatus.

FIG. 2 is a configuration diagram of a copier equipped with a sheet post-processing device.

FIG. 3 is a layout diagram of each sheet detection switch in an offset mode of the sheet post-processing apparatus.

FIG. 4 is a layout diagram of each sheet detection switch in a staple mode of the sheet post-processing apparatus.

FIG. 5 is a diagram illustrating a driving state of a pulse motor when a large sheet is discharged in the first embodiment.

FIG. 6 is a diagram showing a driving state of a pulse motor when a small sheet is discharged in the first embodiment.

FIG. 7 is a flowchart showing an operation process of the sheet post-processing apparatus in an offset mode.

FIG. 8 is a flowchart showing an operation process in a staple (single) mode of the sheet post-processing apparatus.

FIG. 9 is a flowchart illustrating an operation process of the sheet post-processing apparatus in a staple (multi) mode.

FIG. 10 is a flowchart showing an operation process in a staple (multi) mode of the sheet post-processing apparatus.

FIG. 11 is a flowchart showing an operation process in a staple (multi) mode of the sheet post-processing apparatus.

FIG. 12 is a flowchart illustrating an operation process in a staple (multi) mode of the sheet post-processing apparatus.

FIG. 13 is a flowchart showing an operation process of the sheet post-processing apparatus in a staple (multi) mode.

FIG. 14 is a diagram illustrating a driving state of a pulse motor when a small sheet is discharged in the second embodiment.

FIG. 15 shows an example in which an A3-size sheet is set to 5 in the third embodiment.
The figure which shows the drive state of the pulse motor at the time of discharging 0 sheets.

FIG. 16 shows a case where an A4 size sheet is set to 5 in the third embodiment.
The figure which shows the drive state of the pulse motor at the time of discharging 0 sheets.

FIG. 17 shows a case where two sheets of A3 size are used in the third embodiment.
Diagram showing the driving state of the pulse motor when discharging sheets

FIG. 18 shows a case where two sheets of A4 size are used in the third embodiment.
Diagram showing the driving state of the pulse motor when discharging sheets

FIG. 19 is a diagram illustrating a conventional state of discharging large sheets to a discharge tray.

FIG. 20 is a diagram showing a conventional state of discharging small sheets to a discharge tray.

[Description of Signs] S sheet 45 post-processing section 46 sheet receiving table 51 discharge section 56 discharge tray 59, 70, 80 control section

Claims (3)

(57) [Claims] 1. A sheet post-processing apparatus comprising: a post-processing section for performing post-processing on a sheet on a sheet receiving table; and a discharge section for discharging the post-processed sheet to a discharge tray, according to a sheet size. A control unit for controlling the driving of the discharge unit is provided. The control unit includes a large sheet discharging unit for increasing a discharge speed of the sheet by the discharge unit when the sheet has a large size of B4 or more , and a small sheet discharging unit of A4 or less. A sheet post-processing apparatus comprising: a small sheet discharging unit configured to reduce a sheet discharging speed of a sheet discharging unit when the sheet is of a size. 2. A sheet post-processing apparatus comprising: a post-processing section for performing post-processing on a sheet on a sheet receiving table; and a discharge section for discharging the post-processed sheet to a discharge tray. A control unit for controlling the driving of the discharge unit is provided. The control unit includes a large sheet discharging unit for increasing a discharge speed of the sheet by the discharge unit when the sheet has a large size of B4 or more , and a small sheet discharging unit of A4 or less. A sheet post-processing apparatus comprising: a discharge speed changing unit that switches a discharge speed of a sheet by a discharge unit from a high speed to a low speed during discharge when the size is a size. 3. A sheet post-processing apparatus comprising: a post-processing section for performing post-processing on a sheet on a sheet receiving table; and a discharge section for discharging the post-processed sheet to a discharge tray. A control unit is provided for controlling the driving of the discharge unit in accordance with the number of sheets thereafter, and the control unit
And large sheets large number discharging means number in B4 above large size to slow the discharging speed of the sheet by the discharging unit time increases, the sheet is small number in a large size or B4
Large sheet that increases the sheet ejection speed by the sheet ejection section
A small number of sheets ejection means and sheets are small size of A4 or less
A miniature sheet large number discharging means to increase the discharge speed of the sheet by the discharge unit when the number is large, the sheet is A4 following sub
When the number of sheets is small and the number of sheets is
A sheet post-processing apparatus comprising : a small-sheet small-number sheet discharging means for lowering an output speed .