JP2667330B2 - 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 relates to a sheet post-processing apparatus which is used in an image forming apparatus such as a copying machine or a laser beam printer and performs post-processing such as binding or punching on copied sheets.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine for copying an image of a document on a sheet is disclosed in, for example, Japanese Patent Laid-Open No. 2-144.
As disclosed in Japanese Patent Publication No. 370, there is an apparatus provided with a sheet post-processing apparatus for binding a plurality of sheets. As shown in FIG. 13A, such a sheet post-processing apparatus aligns and stacks the copied sheet S conveyed from the machine body 71 side on the staple plate 72, and then incorporates the sheet. The stapler 73 binds the sheets S with staples and performs bookbinding. The bound sheets S are sandwiched between the discharge rollers 74 and 75 and discharged onto the discharge tray 76.

In the above-mentioned sheet post-processing apparatus, the first and second conveyances having different path lengths from the carry-in port 77 of the sheet S, which is opened on the machine body 71 side, to the staple plate 72. Roads 78a and 78b are formed,
A deflector 79 is disposed at a branch point between the first and second transport paths 78a and 78b, and the first and second transport paths 78a and 78b are connected to the first
The mode is switched to either the transport path 78a or the second transport path 78b. The first transport path 7
8a has a longer path length than the second conveyance path 78b, and is joined again to the second conveyance path 78b on the downstream side. At the front end of the path, the sheet S is stapled from within the path. Discharge roller 8 that discharges paper onto the plate 72
0 is provided.

When performing bookbinding of a plurality of sets, the sheet post-processing apparatus performs a predetermined bookbinding process on a first set of sheets S on a staple plate 72 as shown in FIG. during there, while conveying the sheet S ₁ of the first sheet of the next conveyed from the machine body 71 side in the first conveying path 78a, so as to convey the second sheet S ₂ in the second transport path 78b It has become. As a result, the sheet post-processing apparatus performs the above-mentioned sheet S ₁ as shown in FIG.
In a state where S ₂ is overlapped, the sheet is discharged from the sheet discharging roller 80 onto the staple plate 72 and the first sheet S
It is designed to increase the time lost and the speed of bookbinding.

[0005]

However, as in the prior art, the path length of the first transport path 78a is changed to the second transport path 78b.
In the configuration in which the first and second sheets S ₁ and S ₂ of the _{second set} are discharged onto the staple plate 72 in synchronization with each other, Although it is possible to perform bookbinding at high speed, in order to allow the same configuration as described above even in a large-sized sheet S,
The length of each of the transport paths 78a and 78b must be increased, which inevitably leads to an increase in the size of the apparatus. Further, in order to avoid the increase in the size of the apparatus and to increase the distance by complicatingly curving the shape of each of the conveyance paths 78a and 78b, the conveyance path of the sheet S is complicatedly curved. However, there is a problem that the sheet quality is deteriorated.

[0006] The sheet post-processing apparatus of the present invention has been made in view of the above-mentioned conventional problems, and does not increase the size of the apparatus or reduce the sheet quality due to the curving of the conveyance path. It increases the time loss when performing post-processing such as bookbinding on sheets, reduces the size of parts, reduces the number of parts, enables downsizing and cost reduction of equipment, and aligns multiple sheets during bookbinding. The purpose of the present invention is to perform the process more reliably and to suppress the occurrence of alignment failure and the like.

[0007]

In order to solve the above-mentioned problems, a sheet post-processing apparatus according to the present invention includes a conveying roller for dropping sequentially conveyed sheets from a front end of a conveying path onto a post-processing plate below. In a sheet post-processing apparatus provided with conveying direction aligning means for slidingly contacting the trailing end of the dropped sheet and moving backward from the falling position to align the trailing end, the conveying path branches up and down into a plurality of conveying paths. While the sheet on the post-processing plate is subjected to a predetermined post-processing and is discharged from the post-processing plate, the sheet conveyed to the lower conveyance path is temporarily put on standby, and then the lower sheet is removed. There is provided conveyance control means for controlling the conveyance roller so as to drop together with the sheet conveyed to the upper side, and each end of the plurality of conveyance paths projects in the sheet feeding direction as the upper side conveyance path. Is characterized by That.

[0008]

According to the above arrangement, in the sheet post-processing apparatus, when post-processing is performed on a plurality of sheets, the post-processing is performed on the first sheet on the post-processing plate and discharged from the post-processing plate. During this time, the transport control means stops the transport rollers formed in the lower transport path, temporarily stops the first sheet of the second set transported in the lower transport path, and waits for Then, the rotation of the transport roller is restarted at a predetermined timing, and the first sheet is dropped in synchronization with the second sheet transported on the upper transport path,
The time required to perform post-processing on the first sheet is increased. Therefore, the first sheet, the second sheet, and the sheet can be synchronously discharged without increasing the path length of the first sheet conveyance path as in the related art.

[0009] Further, since the transport path branched into a plurality of sections protrudes in the sheet feeding direction toward the upper transport path, a shift occurs at the drop position of each sheet discharged from the plurality of transport paths, The sheet discharged from the lower conveyance path falls closer to the conveyance direction alignment means. Therefore,
When the conveying direction aligning unit slides on the trailing end of the dropped sheet and aligns the trailing edge, the sheet is inevitably aligned sequentially from the sheet located on the lower side, so that poor alignment hardly occurs.

[0010]

1 to 12 show an embodiment of the present invention.
The following is a description based on (a), (b) and (c). In this embodiment, a case where the sheet post-processing apparatus is applied to a copying machine as an image forming apparatus is illustrated.

As shown in FIG. 2, the copying machine according to the present embodiment has a body main body 1 for copying an image of a document M onto a sheet S. A document transporting device 30 for transporting the document M to the exposure section 2 formed on the upper end surface of the document is provided.

The body 1 has an exposure section 2 at its upper end.
And an optical system 9 including a light source lamp 4, mirrors 5, 6 and 7, and a lens 8, and a photosensitive drum 10 are disposed below the exposure glass 3. Have been. The optical system 9 optically scans the original M conveyed to the exposure unit 2 by the original conveying device 30 to be described later with the light emitted from the light source lamp 4, and reflects the reflected light to each of the mirrors 5 and 6. By irradiating the exposure point A on the surface of the photoconductor drum 10 via the lens 7 and the lens 8, the surface of the photoconductor drum 10 uniformly charged by the main charger unit 11, which will be described later, is statically corresponding to the image of the original M An electrostatic latent image is formed.

Around the photosensitive drum 10, a main charger unit 11 for charging the surface of the photosensitive drum 10 to a predetermined potential as described above, and a developing unit 12
, A transfer charger 13 and a peeling charger 14 are provided, and the electrostatic latent image formed on the surface of the photosensitive drum 10 is developed as a toner image by the developing unit 12, and then this toner image is transferred. The image is transferred to a sheet S conveyed by a charger 13 through a sheet conveying path 15 described later. The release charger 14 separates the sheet S on which the toner image is transferred from the photosensitive drum 10.

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 having sheet feeding rollers 16, 17, and 18, a sheet feeding cassette 20, and a sheet feeding deck 21 are provided, respectively. The sheets S placed or accommodated on the table 19, the sheet cassette 20, and the sheet deck 21 are fed to the photosensitive drum 10 through the sheet conveying path 15. On the other hand, a transport belt 22 that transports the sheet S to which the toner image has been transferred and a fixing device 23 that fixes the toner image onto the sheet S are disposed downstream of the sheet transport path 15.

Downstream of the fixing unit 23, the sheet S is conveyed in the sheet post-processing device 40, which will be described later,
5 is provided. 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 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. A feeding belt 33 for feeding,
A transport belt 34 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. Then, the original transport device 3
Reference numeral 0 indicates that the document M on the document tray 32 is fed to the exposure unit 2 by the feeding belt 33 and the document M is positioned at a predetermined position on the exposure glass 3 by the transport belt 34. 4, the original M is arranged in the state of the optical scanning.

Further, in the copying machine according to the present embodiment, a sheet post-processing device 40 is provided downstream of the above-described sheet conveying path 15.

As shown in FIG. 1, the sheet post-processing apparatus 40 is provided with a post-processing conveyance path 41 for conveying the sheet S conveyed from the machine body 1 in the apparatus 40 and a staple staple for aligning the sheet S. Post-processing means 45 for performing bookbinding processing by
And a discharge unit 51 for discharging the bound sheets S from the inside of the apparatus 40, and a discharge tray 56 for placing the sheets S discharged from the inside of the apparatus 40.

The post-processing conveyance path 41 has, at one end thereof, a carry-in port 41a for carrying the sheet S conveyed from the machine body 1, and is bifurcated in the middle of the path to form a two-stage upper and lower section. Bypass 41b and main path 41c
Are formed. The distal ends of the bypass 41b and the main path 41c are formed before and after in the sheet conveyance direction, which is the sheet feeding direction, and the bypass 41b
Is formed ahead of the front end of the main path 41c. A pair of upper and lower conveying rollers 42 and 43 are disposed at the respective ends of the bypass 41b and the main path 41c, and the sheets conveyed through the paths 41b and 41c are disposed below. The staple tray 46 is ejected.
On the other hand, at a branch point between the bypass 41b and the main path 41c, a deflector 44 as a path switching means rotatable in the B ₁ -B ₂ direction is disposed, and the conveyance path of the sheet S is changed to the bypass 41b or The path is switched to one of the main paths 41c.

Further, the post-processing transport path 41 is
As shown in the figure, the bypass 41b and the main path 41c
The sheet detection switches SW ₁ and SW ₂ for detecting the sheet S are provided in the middle of each path. These sheet detection switches SW ₁ and SW ₂ and a sheet detection switch (not shown) that detects a sheet S on the staple plate 46 described later are connected to a control system (not shown) provided in the sheet post-processing apparatus. Controls the driving of the transport roller 43, which will be described later, based on detection signals from these detection switches. That is, each of the sheet detection switches SW ₁ · S
W ₂ , the sheet detection switch on the staple plate 46, and the control system constitute the transport control means of the present invention.

The post-processing means 45 is composed of a staple plate 46 as a post-processing plate, a width shift plate 47, a paddle 48, and a stapler 49.

The staple plate 46 has a first end disposed at a discharge port 40a formed on the outer surface of the apparatus 40 and a second end inclined at a lower position than the one end. The sheet S to be bound (stapled) is disposed below the path 41 and is stacked. The staple plate 46 is provided with a sheet detection switch (not shown) as described above, so that the presence or absence of the sheet S on the staple plate 46 is detected.

The width shift plate 47 includes a staple plate 46.
And a staple plate 46 which is provided so as to be able to advance and retreat in a direction perpendicular to the paper surface of FIG.
The upper sheet S is aligned in the width direction. A stopper 50 is provided at a lower end side of the staple plate 46, and the stopper 50 is used for positioning a rear end portion of the sheets S stacked on the staple plate 46. The paddle 48, which is a conveying direction adjusting means, is provided with its blades abutting on the upper surface of the staple plate 46, and is provided rotatably in the C direction. The blades are slid in contact with the trailing edge of the sheet S, and the sheet S is moved to the stopper 50 so that the trailing edge of the sheet S is aligned, thereby aligning the sheet S in the transport direction. The stapler 49 is disposed at a side position of the staple plate 46 to which the paddle 48 is in contact, and is configured to bind the sheets S stacked on the staple plate 46 with staples and bind the book.

The discharge means 51 comprises a pushing member 52 and discharge rollers 53 and 54.

The extruding member 52 is provided on an extension of the lower end of the staple plate 46, and is provided so as to be able to advance and retreat in the direction D ₁ -D ₂ along the upper surface of the staple plate 46, and to form a bound sheet. S is pushed out from the staple plate 46 toward the discharge port 40a. The discharge roller 53 is rotatably supported by the upper end portion of the staple plate 46 so as to be rotatable in the G ₁ -G ₂ directions. On the other hand, the discharge roller 54
Has its rotating shaft is pivotally supported at one end of the arm member 55, the other end of the arm member 55 is rotatably provided on the F ₁ -F ₂ direction about the fulcrum E . Then, discharge rollers 53 described above, the staple mode to be described later, the staple plate 4 by the rotation of the G ₂ direction
While assist alignment of the conveying direction of the sheet S to be stacked on the 6, so as to discharge the sheet S bound by the rotation of the G ₁ direction to the discharge tray 56. The discharge roller 54 is offset mode to be described later, in accordance with the rotation of the G ₁ direction of the discharge roller 53, the arm member 5
5 by being rotated in the F ₂ direction, and sandwiched the sheets S between the discharge roller 53, which is directly sheet S from the post-processing transport path 41 to discharge onto the discharge tray 56.
The discharge rollers 53 and 54 are, as shown in FIG.
At contact state between each other in the offset mode, so as to constitute a sheet detection switch SW ₃ for detecting the sheet S.

The discharge tray 56 is attached to the apparatus 40 at a position below the discharge roller 53, and the elevator unit 57 and the shift unit 5
By 8 and is arranged, and H ₁ -H ₂ direction which is the vertical direction, is provided to be retractable in the direction perpendicular to the plane of FIG. 2, the tray position is adjusted according to the bearing for the sheet S It has become so.

In the above configuration, the process of conveying the sheet S in the sheet post-processing apparatus 40 will be described below. In the following description, the offset mode in which the sheets S conveyed from the main body 1 are discharged to the discharge tray 56 one by one without performing post-processing on the sheets S conveyed from the main body 1, After the post-binding process, the staple (single) mode in which only one copy of a sheet S (hereinafter, referred to as a bookbinding sheet S) is discharged to a discharge tray 56, and the sheet S conveyed from the machine body 1 After a post-binding process is performed, a description will be given of the staple (multi) mode in which a plurality of sets of bound sheets S are sequentially discharged to the discharge tray 56.

First, in the offset mode, as shown in the flow chart of FIG. 5, when the sheet post-processing apparatus 40 receives the number of offset sheets from the body 1 (S1), the number of offset sheets is set in the apparatus 40 (S2). ). Next, when the device 40 receives an operation start from the body 1 (S3), a start process is performed (S4), and the number of processed sheets is cleared (S5).

Thereafter, the sheet S on which the image of the document M has been copied by the body 1 is carried into the apparatus 40 through the carry-in port 41a, passes through the main path 41c, and is then moved between the discharge rollers 53 and 54. And is discharged to the discharge tray 56. At this time, the sheet S described above is conveyed in the main path 41c by the ON state of the sheet detection switch SW ₂ is detected (S6), also, O of the sheet detection switch SW ₃
In the N state (S7) and the OFF state (S8), conveyance and passage between the discharge rollers 53 and 54 are detected, and the number of processed sheets is increased (S9).

Next, it is determined whether or not the number of processed sheets increased as described above matches the number of offset sheets (S1).
0). If the number of processed sheets does not match the number of offset sheets in S10, the process returns to S6 again. On the other hand, if the processed number matches the offset number, the processed number is cleared (S
11) Then, the lowering (S12), the offset (S13) and the raising (S14) of the discharge tray 56 are sequentially performed.

Then, the presence or absence of the end reception from the body main body 1 to the apparatus 40 is determined (S15). When there is no end reception, the process returns to S6 again. When there is the end reception, the end processing is performed. (S16) The offset mode as described above is terminated.

Next, in the staple (single) mode, as shown in the flowchart of FIG. 6, when the sheet post-processing apparatus 40 receives the number of staples from the machine body 1 (S21), the number of staples is set in the apparatus 40. Is performed (S22). Next, when the apparatus 40 receives an operation start from the body 1 (S23), a start process is performed (S24), and the number of processed sheets is cleared (S25).

Thereafter, the sheet S on which the image of the document M has been copied by the body 1 is carried into the apparatus 40 through the carry-in port 41a, passes through the main path 41c, and is discharged onto the staple plate 46. Paper. At this time, the sheet S described above, the sheet detection switch SW ₂ in the ON state (S2
6) and the OFF state (S27), the main path 41
The conveyance at c is detected, whereby the timer of the device 40 is cleared (S28), and the number of processed sheets is increased (S29). When the predetermined time set by the timer elapses (S30), it is determined that the discharge of the sheet S onto the stapling plate 46 is completed.
The sheet S on the stapling plate 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 increased as described above matches the number of staples (S3).
2). If the number of processed sheets does not match the number of offset sheets in S32, the process returns to S26. On the other hand, if the number of processed sheets coincides with the number of staples, the number of processed sheets is cleared (S33), and then the sheet S on the staple plate 46 is rotated by the paddle 48 in the direction C and the discharge roller 53 is rotated by G. _The paper is aligned in the transport direction by rotation in _two directions, and is stapled by the staples of the stapler 49 (S34).

[0035] Then, the bookbinding sheet S which stapling processing has been performed as described above is extruded advancing movement in the D ₁ direction member 52, and the staple plate upper 46 by the rotation of the G ₁ direction of the discharge roller 53 From the output tray 56
(S35). Then, after the discharge tray 56 is adjusted (S36), when the apparatus 40 receives an operation end from the machine body 1 (S37), an end process is performed (S38), and the above-described staple (single) is performed. The mode is terminated.

Next, in the staple (multi) mode, as shown in the flowcharts of FIGS.
When the sheet post-processing device 40 receives the number of staples from the body 1 (S41), the number of staples is set in the device 40 (S42). Next, when the apparatus 40 receives an operation start from the body 1 (S43), a start process is performed (S44), and the number of processed sheets is cleared (S45).

Thereafter, the sheet S on which the image of the document M has been copied by the body 1 is carried into the apparatus 40 through the entrance 41a, passes through the main path 41c, and is discharged onto the staple plate 46. Paper. At this time, the sheet S described above is conveyed in the main path 41c by the ON state of the sheet detection switch SW ₂ is detected (S46), then whether or not the sheet detection switch SW ₂ is turned OFF is determined (S47 ).

[0038] At S47, if the sheet detection switch SW ₂ is still ON state, the process proceeds to S48, the bookbinding sheet S is whether already discharged from above the staple plate 46 is determined. If the bookbinding sheet S has not yet been discharged from the staple plate 46 in S48, the bookbinding sheet S is discharged to the discharge tray 56 by the pushing member 52 and the discharge roller 53 (S49), and the process returns to S47 again. On the other hand, the bookbinding sheet S is placed on the staple plate 46.
If the output tray 5 has been discharged, the process proceeds to S50.
It is determined whether or not 6 has been adjusted. In 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), and the process returns to S47. Then, in S47, when the OFF state of the sheet detection switch SW ₂ is detected, along with this, the timer device 40 is cleared (S52), also the number of processing sheets is up (S5
3).

Next, it is determined whether the number of processed sheets increased as described above is the first number (S54). S54
If the number of processed sheets is not the first sheet, the process proceeds to S66 described later.
On the other hand, if the number of sheets to be processed is the first sheet, the process proceeds to S55, and it is determined whether or not the preparation of the stapling plate 46 is OK. In S55, the staple plate 4
If the staple plate 46 has not been prepared, the process proceeds to S66. If the staple plate 46 has not been prepared, the rotation of the transport roller 43 is stopped to stop the transport of the first sheet S. (S56), and the deflector 4
4 is rotated in the B ₁ direction, the conveying 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 state of ₁ (S58).
At S58, if it is not the sheet detection switch SW ₁ is still ON, the process proceeds to S59, whether bookbinding sheet S is already discharged is determined. If the bookbinding sheet S has not yet been discharged from the staple plate 46 in S59, the bookbinding sheet S is discharged to the discharge tray 56 by the pushing member 52 and the discharge roller 53 (S6).
0), while returning to S58 again, the staple plate 4
6. If the bookbinding sheet S has been discharged from above, the process proceeds to S61.
Then, it is determined whether or not the discharge tray 56 has been adjusted.
If the discharge tray 56 has been adjusted in S61,
On the other hand, if the ejection tray 56 has not been adjusted, the ejection tray 56 is adjusted (S62), and the process returns to S58. Then, in S58, the ON state of the seat detection switch SW ₁ is detected, then the sheet detection switch S
By the OFF state of the W ₁ is detected (S63), the deflector 44 is rotated in the B ₂ direction, the conveying path of the sheet S is switched to the main path 41c (S64), also the transport roller 43 is rotated Then, the conveyance of the first sheet S is restarted (S65). As a result, the first sheet S passing through the main path 41c and the second sheet S passing through the bypass 41b are discharged synchronously on the staple plate 46.

Next, returning to S52, the timer of the apparatus 40 is cleared, and the number of processed sheets is increased (S52).
53), and proceed to S54. If it is determined in S54 that the number of processed sheets is not the first sheet, then the process proceeds to S66, in which it is determined whether or not a predetermined time set by the timer has elapsed. When the predetermined time has elapsed, it is determined that the discharge of the sheet S onto the staple plate 46 is completed, and the sheet S on the staple plate 46 is aligned in the width direction by the width diverter 47 (S67). Then, 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 in S68, the process returns to S46. on the other hand,
If the number of processed sheets matches the number of staples, the number of processed sheets is cleared (S69), and then the sheet S on the staple plate 46 is rotated by the paddle 48 in the C direction.
And while being aligned in the conveying direction by the rotation of the G ₂ direction of the discharge roller 53, the staple processing stapled by staple of the stapler 49 is subjected (S70),
After that, the process returns to S46 again.

[0042] Then, at S46, when the detection of the sheet S by the sheet detection switch SW ₂ is eliminated, the process proceeds to S71, whether bookbinding sheet S is already discharged is determined.
If the bookbinding sheet S has not yet been discharged from the staple plate 46 at S71, the bookbinding sheet S is discharged by the pushing member 52 and the discharge roller 53 to the discharge tray 5 (S71).
6 (S72), and returns to S46 again. If the bookbinding sheet S has been discharged from the staple plate 46, the process proceeds to S73, where it is determined whether or not the discharge tray 56 has been adjusted. If the ejection tray 56 has not been adjusted in S73, the ejection tray 56 is adjusted (S7).
4) While returning to S46, if the discharge tray 56 has been adjusted, the process proceeds to S75, where it is determined whether or not the apparatus 40 has received an operation end from the machine body 1. In S75, if the operation end has not been received, the process returns to S46. On the other hand, if the operation end has been received, an end process is performed (S7).
6), the staple (multi) mode is terminated.

As described above, when binding a plurality of copies,
As shown in FIG. 12 (a), the staple plate 46
The sheet S of the first copy above while applying a predetermined binding process while conveying the sheet S ₁ of the first sheet of the second set conveyed from the machine body 1 side at the main path 41c, stop the rotation of the conveying roller 43 during conveyance, temporarily stops the conveyance of the sheet S _1, in this state, as shown in FIG. 12 (b), carried by the second sheet S ₂ the bypass 41b I do. Then, the transport rollers 4 that are temporarily stopped are synchronized with the timing at which the _second sheet S2 is discharged.
3 is resumed, and as shown in FIG. 12C, the first sheet S ₁ and the second sheet S are placed on the staple plate 46 from which the discharge of the first sheet S has been completed. and synchronizing the S ₂ is adapted to discharge the paper. As a result, unlike the related art, the size of the apparatus is not increased, and it is possible to increase the time loss of the bookbinding time of the first sheet S with a small apparatus.

Further, the main path 41c and the bypass 4 of the post-processing conveyance path 41 in the above-described sheet post-processing apparatus 40 are used.
1b are formed so as to be shifted in the front and rear direction in the sheet conveying direction, and the front end of the bypass 41b provided on the upper side is connected to the main path 41 provided on the lower side.
It is formed forward of the leading end of the sheet c in the sheet conveying direction. Therefore, on the staple plate 46, when discharged in synchronization with the sheet S ₁ of the first sheet and the second sheet S _2, paddler 48 is inevitably sequential from the sheet S ₁ positioned on the lower side Since they are aligned, the risk of misalignment is avoided. Further, since the leading ends are formed so as to be shifted from each other, even if the disposing positions of the bypass 41b and the main path 41c are brought closer, the conveying rollers 42 and 43 provided at the respective leading ends come into contact with each other. Since there is no fear, the size of the device can be further reduced.

The present embodiment does not limit the present invention, and various changes can be made within the scope of the present invention.
For example, in the above-described embodiment, the transport roller 43 performs the detection based on the detection signals from the sheet detection switches SW ₁ and SW ₂ and a sheet detection switch (not shown) provided on the stapling plate 46. It is not necessary to limit the conveyance control means to such a configuration. By controlling not only the conveyance roller 43 but also the rotation of the conveyance roller 42 at the same time, the _first sheet S ₁ conveyed on the main path 41c can be It is also possible to synchronously discharge the _second sheet S2 conveyed through the bypass 41b onto the stapling plate 46 at a finer timing.

[0046]

As described above, in the sheet post-processing apparatus according to the first aspect of the present invention, the conveying path is divided into a plurality of conveying paths vertically, and a predetermined post-processing is performed on the sheet on the post-processing plate. While being discharged from the post-processing plate, the sheet conveyed to the lower conveying path is temporarily made to stand by, and then the conveying roller is used to drop the lower sheet together with the sheet conveyed to the upper side. A transport control unit for controlling the transport path is provided, and each end of each of the plurality of transport paths protrudes in the sheet feeding direction toward the upper transport path.

As a result, a time loss in post-processing time can be obtained even for a large-sized sheet without increasing the path length of each branch path of the conveying path. For this reason,
Without inviting larger equipment and lowering sheet quality,
This has the effect of speeding up post-processing of the sheet. Also, the lower the sheet discharged from each transport path is, the closer the sheet is located to the transport direction aligning means, and the greater the deviation of the trailing end of each sheet, the more the sheet ejected from each transport path is shifted. The alignment by the means is reliably performed, the alignment failure does not occur, and the sheet quality can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a sheet post-processing apparatus constituting a copying machine according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of the copying machine.

FIG. 3 is an explanatory diagram showing each sheet detection switch provided in a post-processing conveyance path constituting the above-described sheet post-processing apparatus.

FIG. 4 is an explanatory diagram showing a sheet detection switch constituted by each discharge roller constituting the sheet post-processing apparatus.

FIG. 5 is a flowchart illustrating an operation process of the sheet post-processing apparatus in an offset mode.

FIG. 6 is a flowchart showing an operation process in a staple (single) mode of the sheet post-processing apparatus.

FIG. 7 shows a staple (multi) of the sheet post-processing apparatus.
9 is a flowchart showing a part of an operation process in a mode.

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

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

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

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

FIGS. 12A, 12B, and 12C are explanatory diagrams each illustrating a sheet conveyance operation in a post-processing conveyance path in a staple (multi) mode.

FIGS. 13A and 13B are explanatory views showing a sheet conveying operation by a conventional sheet post-processing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Body main body 40 Sheet post-processing apparatus 41 Post-processing conveyance path (conveyance path) 41b Bypass (conveyance path) 41c Main path (conveyance path) 43 Conveyance roller 44 Deflector 46 Staple plate (post-processing plate) 48 Paddle (conveyance direction alignment) Means) SW ₁ sheet detection switch SW ₂ sheet detection switch S sheet

Claims (1)

(57) [Claims] 1. A conveying roller for dropping a sequentially conveyed sheet from the front end of a conveying path onto a post-processing plate below, and a sheet that slides on the rear end side of the dropped sheet and moves rearward from the drop position to move the rear end. In a sheet post-processing apparatus provided with a conveying direction aligning means for aligning, the conveying path is branched into a plurality of conveying paths up and down, a predetermined post-processing is performed on a sheet on the post-processing plate, and While the sheet is discharged, the sheet conveyed to the lower conveying path is temporarily put on standby, and then conveyance control means for controlling the conveying roller is provided to drop the lower sheet together with the sheet conveyed to the upper side. A sheet post-processing apparatus, wherein each of the leading ends of the plurality of transport paths protrudes in the sheet feeding direction toward the upper transport path.