JPH061511A - Sheet delivering mechanism - Google Patents

Abstract

PURPOSE:To manage the following sheet without loss of time after delivering a sheet. CONSTITUTION:A carrying unit 52 moves upward to protrude a carrying belt 55 from the opening 46a of a sheet receiving base 46. The carrying belt 55 abuts on the lower face of a staple-processed sheet S. The carrying belt 55 rotates, and the sheet S is delivered onto a delivering tray by a friction section. A carrying unit 52 plunges into the opening 46a of the sheet receiving base 46 to lead the following sheet onto the sheet receiving base 46.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet discharging mechanism that is used in an image forming apparatus such as a copying machine or a laser beam printer, and discharges a sheet carried in from these apparatuses onto a discharging tray.

[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 the purpose of automating copying and stapling or punching of sheets after copying. ing. The automatic document feeder is provided on a document table of a copying machine and conveys a plurality of documents one by one onto the document table of the copying machine. Further, the post-processing device performs post-processing work such as stapling or punching on the copied sheets discharged from a copying machine or the like every predetermined number of sheets.

In a conventional post-processing apparatus, for example, as disclosed in Japanese Patent Application Laid-Open No. 2-144370, sheets discharged from a copying machine are stacked on a processing tray, stapled by a stapler, and then discharged. It is discharged to the discharge tray on the upper end side of the processing tray by the roller. At this time, since the discharge roller abuts and conveys only the uppermost and lowermost sheets of the plurality of sheets after the stapling process, the sheets are likely to be misaligned and the sheets may be jammed.

Therefore, in this type of post-processing apparatus, as shown in FIG. 15, there is provided a sheet discharging mechanism V for pushing out the post-processed bound sheet S by the pushing means U provided at the lower end side of the processing tray T. There is something.

This conventional sheet discharge mechanism V is composed of an extruded piece U.
Moves in parallel to the processing tray T and pushes the lower end side of the sheet S to discharge the sheet S to the discharge tray W. In FIG. 14, X and Y are discharge rollers.

[0006]

In the conventional sheet discharging mechanism, since the extruded piece U projects from the upper surface of the processing tray T, the extruded piece U is discharged from the processing tray T after the sheet S is discharged.
The next sheet S cannot be processed unless it returns to the original position on the lower end side of. Therefore, there is a time loss until the extruded piece U returns to its original position.

In view of the above, the present invention is to provide a sheet discharging mechanism capable of processing the next sheet after discharging the sheet to the discharging tray without time loss.

[0008]

The means for solving the problems according to claim 1 of the present invention is as follows.
A conveyor belt 55 that conveys a sheet is provided, and the conveyor belt 55 is provided between a conveyance attitude that protrudes above the upper surface of the sheet receiving stand 46 and a sheet receiving attitude that retracts below the upper surface of the sheet receiving stand 46. Switching means 58 is provided which is switchable and switches the posture of the transport belt 55.

According to a second aspect of the present invention, a frictional portion 59 is provided on the upper surface of the conveyor belt 55 for increasing the frictional force with the sheet.
Is provided.

[0010]

In the means for solving the problems according to the above claims 1 and 2, when the sheet S on the sheet receiving stand 46 is discharged, the conveyor belt 55 is projected from the upper surface of the sheet receiving stand 46 by the switching means 58, and the friction portion 59 forms the sheet. Contact the lower surface of S. Then, the conveyor belt 55 rotates, and the sheet S is discharged onto the discharge tray 65 by the friction portion 59 without slipping. After that, the conveyor belt 55 is retracted below the upper surface of the sheet receiving stand 46 by the switching means 58. Therefore, the conveyance belt 55 does not get in the way, and the next sheet S can be immediately conveyed onto the sheet receiving tray 46.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of the essential parts of a sheet discharging mechanism showing an embodiment of the present invention, FIG.
4 is a block diagram showing the switching means of the transport unit, FIG. 4 is a block diagram of a copying machine equipped with a post-processing apparatus, FIG. 5 is a block diagram of the sheet post-processing apparatus, and FIG. 6 is each sheet in the offset mode of the sheet post-processing apparatus. FIG. 7 is a layout view of the detection switches, FIG. 7 is a layout view of each sheet detection switch in the staple mode of the sheet post-processing apparatus, FIG. 8 is a flowchart showing an operation process of the sheet post-processing apparatus in the offset mode, and FIG. FIG. 10 to FIG. 14 are flowcharts showing an operation process in the staple (single) mode of the apparatus, and FIGS. 10 to 14 are flowcharts showing an operation process in the staple (multi) mode of the sheet post-processing apparatus.

As shown in FIG. 4, the copying machine according to the present embodiment has a document M.
Has a copying machine main body 1 for copying the image of FIG. 1 to a sheet S, and an original document conveying unit for conveying an original document M to an exposure unit 2 formed at the upper end of the copying machine main body 1 at the upper portion of the copying machine main body 1. A device 30 is provided.

The copying machine main body 1 has an exposure unit 2 on the upper portion thereof.
The exposure glass 3 forming the optical system 9 is disposed below the exposure glass 3, and the optical system 9 including the light source lamp 4, the mirrors 5, 6, 7 and the lens 8 is disposed below the exposure glass 3.
Performs optical scanning on the document M transported to the exposure unit 2 by the document transport device 30 by the irradiation light from the light source lamp 4, and reflects the reflected light on the mirrors 5, 6, 7 and the lens 8.
By irradiating the exposure point A on the surface of the photoconductor drum 10 through the, an electrostatic latent image corresponding to the image of the original 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 are provided.
And a peeling charger 14 are provided. The electrostatic latent image formed on the surface of the photosensitive drum 10 is developed as a toner image by the developing device 12, and the toner image is transferred to the sheet S by the transfer charger 13. 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 the sheet S for transferring the toner image is provided below the photosensitive drum 10. On the upstream side of the sheet conveying path 15, there are provided a paper feed table 19 including paper feed rollers 16, 17, and 18, a paper feed cassette 20, and a paper feed deck 21, respectively. The sheet S placed or accommodated in these is fed to the photosensitive drum 10 through the sheet conveying path 15. On the other hand, on the downstream side of the sheet conveyance path 15, a conveyance belt 22 that conveys the sheet S on which the toner image is transferred, and a fixing device 2 that fixes the toner image on the sheet S
And 3 are provided.

On the downstream side of the fixing device 23, a deflector 24 is provided which branches the conveying direction of the sheet S into a sheet post-processing device 40 and a re-conveying path 25. The re-conveyance path 25 forms a circulation path for re-conveying the sheet S on which the toner image has been transferred by the photoconductor drum 10 to the photoconductor drum 10, and an intermediate tray 26 is disposed in the middle of the path to convey the sheet S to the sheet S. It enables double-sided copying.

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

Then, the document feeder 30 feeds the document M on the document tray 32 to the exposure section 2 by the feeding belt 33, and at the same time, exposes the exposure glass 3 by the feeding belt 34.
By positioning the document M at a predetermined upper position, the document M is arranged in a state in which it can be optically scanned by the light source lamp 4.

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

As shown in FIG. 5, 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 mechanism 45 for performing binding processing with staples and a post-processing apparatus main body 4 for binding the bound sheets S.
The sheet discharge mechanism 51 discharges the sheet S from the inside of the sheet 0a, and the discharge tray 65 on which the sheet S discharged by the discharge mechanism 51 is placed.

As shown in FIGS. 6 and 7, the post-processing conveyance path 41 has a carrying-in port 41a at one end thereof for carrying in the sheet S conveyed from the copying machine main body 1. In the middle of the path, it is bifurcated into a two-step bypass 41b and a main path 41c, and a pair of upper and lower transport rollers 42 and 43 are arranged at each end. At the branch point between the bypass 41b and the main path 41c, a deflector 44 serving as a path switching unit that is rotatable in the B ₁ -B ₂ direction is provided to bypass the sheet S transport path to the bypass 41b or the main path 41c. It is designed to switch to either path.

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. 5, the post-processing mechanism 45 includes a width side plate 47 for aligning the sheets S accumulated in the sheet receiving base 46 from the post-processing conveying path 41 in the width direction, and the sheet S similarly.
And a stapler 49 for binding the aligned sheets S with staples and binding them.

The sheet pedestal 46 is arranged at a lower position of the post-processing conveyance path 41 with one end side thereof being arranged near the discharge port 40b and the other end side being inclined downward as compared with the one end side. ing. A reference guide for positioning the side of the sheet S is attached to the center of the side of the sheet receiving base 46, and a stopper 50 for positioning the lower end of the sheet S is provided at the lower end of the sheet receiving base 46. Has been formed.

The width-wise plate 47 is arranged so as to face the reference guide, and is arranged so as to be movable back and forth in the width direction of the sheet S. The paddler 48 is rotatably supported by the post-processing apparatus main body 40a in the C direction, and the blades of the paddler 48 are provided in the sheet receiving tray 4
6 is in contact with the upper surface of the lower end side. The stapler 49
Is disposed on the side of the paddle 48 on the lower end side of the sheet receiving base 46.

The sheet discharge mechanism 51 includes a transport unit 52 for transporting the sheet S toward the discharge port 40b of the main body 40a of the post-processing apparatus, and discharge rollers 53 and 54 arranged near the discharge port 40b. It consists of

The transport unit 52 includes the sheet receiving table 4
6, an endless conveyor belt 55, a pair of rollers 56 wound around the conveyor belt 55, and a unit for rotatably holding the rollers 56, as shown in FIGS. And a main body 57. In addition, the transport unit 5
2 is a conveyance posture in which the conveyance belt 55 projects upward from the upper surface of the sheet receiving base 46 through an opening 46a formed in the sheet receiving base 46, and a sheet receiving position in which the conveyance belt 55 is recessed below the upper surface of the sheet receiving base 46. A switching means 58 is provided which is switchable between the posture and the posture of the transport unit 52.

As shown in FIG. 2, the conveyor belt 55 has a protrusion-shaped friction portion 59 on its surface for increasing the friction force with the sheet S.
Are formed. The pair of rollers 56 are connected to the drive motor 60 via a gear or the like when the transport unit 52 is in the transporting posture.

As shown in FIG. 3, the switching means 58 includes a rack 61 formed on the side wall of the central projecting portion 57a of the unit body 57, and a pinion 62 which meshes with the rack 61.
And a drive motor 63 for rotating the pinion 62.

The discharge roller 53 has a rotating shaft 53a.
Is rotatably disposed on the upper end of the sheet receiving table 46. On the other hand, the rotation shaft 54a of the discharge roller 54 is pivotally supported on one end side of the arm member 64, and the other end side of the arm member 64 is F _{1 about the} fulcrum E.
It is arranged to be rotatable in the −F ₂ direction.

In the staple mode, the discharge roller 53 assists the alignment of the sheets S stacked on the sheet receiving table 46 in the transport direction by rotating in the G ₂ direction, while rotating in the G ₁ direction by the rotation. The bound sheet S is discharged to the discharge tray 65.

Further, the discharge roller 54, in the offset mode, according to the rotation of the discharge roller 53 in the G ₁ direction,
By rotating the arm member 64 in the F ₂ direction, the sheet S is sandwiched between the sheet S and the discharge roller 53, and the sheet S is directly discharged from the post-processing conveyance path 41 to the discharge tray 65. Note that the discharge roller 54 is disposed a sheet detection switch SW _3, the sheet detection switch SW ₃ is as shown in FIG. 6, detects the sheet S when the contact of the discharge rollers 53 and 54 in the offset mode.

The discharge tray 65 is attached to the main body 40a of the post-processing device below the discharge roller 53, and the elevator unit 66 and the shift unit 67 arranged in the vicinity of the attachment portion make the discharge tray 65 in the vertical direction. _It is movable in the direction perpendicular to the _1- H ₂ direction and the discharge direction.
By these movements, the uppermost bound sheet S of the discharge tray 65 always keeps a certain distance from the discharge roller 53, and the bound sheets S do not overlap each other at the same position but are alternately shifted and overlapped. The position is adjusted.

Further, a control unit 68 including a microcomputer for controlling the post-processing device 40 is provided, and the control unit 68 sequentially performs the post-processing on the sheet S conveyed from the copying machine main body 1 without performing post-processing. The offset mode in which the sheets are discharged one by one to the discharge tray 65, and after the sheets S conveyed from the copying machine body 1 are subjected to the bookbinding post-processing, only one copy of the sheets S (hereinafter referred to as a bookbinding sheet SS) In a staple (single) mode for discharging the sheets to the discharge tray 65 and a staple mode for sequentially discharging a plurality of bookbinding sheets SS to the discharge tray 65 after post-binding processing for the sheets S conveyed from the copying machine body 1. A program for executing the (multi) mode is stored.

Then, the control unit 68 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. To do. The control unit 68 also controls the copying machine side, and the rotation operation of the transport roller 43 is controlled by a timer (not shown) in terms of time.

In the above configuration, in the offset mode, as shown in the flowchart of FIG. 8, when the offset number is input, the control unit 68 receives the offset number (S1) and sets the offset number (S2). Next, when the post-processing device 40 receives the start signal from the control unit 68 (S3), the start process in the offset mode is performed (S4), and the number of processed sheets is cleared (S).
5).

After that, the sheet S on which the image of the original M is copied by the copying machine main body 1 is carried into the post-processing apparatus main body 40a through the carry-in port 41a, and when the main path 41c is passed, the sheet detection switch SW ₂ is turned on. When turned on (S6), conveyance on the main path 41c is detected. Then, the sheet detection switch SW ₃ when passing between the respective discharge rollers 53 and 54 is turned on (S7), when it is discharged to a discharge tray 65 sheet detection switch SW ₃ is turned off (S8), the processing number count It is updated (S9).

Next, it is judged whether or not the processed number counted up as described above matches the offset number (S10). When the number of processed sheets does not match the number of offset sheets, the process returns to S6 again, and the conveyance of the sheet S on the main path 41c is detected. On the other hand, when the processed number matches the offset number, the processed number is cleared (S11),
Next, the discharge tray 65 is sequentially lowered (S12), offset (S13), and raised (S14).

When the copying is completed, the control unit 68
When the post-processing device 40 receives the end signal (S15), the end reception is performed (S16), and the offset mode as described above is ended. If the copying is not completed, the post-processing device 40 does not receive the completion signal and the process returns to S6 again.

Next, in the staple (single) mode, as shown in the flowchart of FIG. 9, when the number of staples is input, the control unit 68 receives the number of staples (S21) and sets the number of staples (S22). .
Next, when the post-processing device 40 receives the start signal from the control unit 68 (S23), the start process in the staple (single) mode is performed (S24), and the number of processed sheets is cleared (S25).

After that, the sheet S on which the image of the original M is copied by the copying machine main body 1 is carried into the post-processing apparatus main body 40a through the carry-in port 41a, and when the main path 41c is passed, the sheet detection switch SW ₂ is turned on. The conveyance in the main path 41c is detected by turning on (S26) and turning off (S27), and the sheet is discharged onto the sheet receiving tray 46 by the discharging roller 43. At this time, the transport belt 55 moves the sheet receiving stand 46.
It is a seat receiving posture that is immersed from the upper surface of the. Then, the timer of the post-processing device 40 is cleared and the timer is started (S28), and the number of processed sheets is counted up (S29). Then, when a predetermined time elapses (S3
0), it is determined that the sheet S on the sheet receiving tray 46 has been discharged, and the sheet S on the sheet receiving tray 46 is aligned in the width direction by the width-wise plate 47 (S31).

Next, it is judged 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 stapled sheets, the process returns to S26 again, and the main path 41 of the sheet S is returned.
The conveyance at c is detected. On the other hand, if the number of processed sheets matches the number of staples, the number of processed sheets is cleared (S3
3) Next, the sheet S on the sheet tray 46 is rotated in the C direction of the paddler 48 and the rotation of the discharge roller 53 in the G ₂ direction, so that the lower end of the sheet S contacts the stopper 50 and is aligned in the transport direction. The staples of the stapler 49 are stapled and stapled (S3).
4).

The transport unit 52 is driven by the drive motor 6
By the rotation of 3, the pinion 62 and the rack 61 move upward, the conveyor belt 55 projects from the opening 46a of the sheet receiving stand 46, and the friction portion 59 contacts the lower surface of the bookbinding sheet SS. Further, the drive motor 60 drives the roller 56.
Rotates to move the transport belt 55, and the bookbinding sheet SS is transported in the direction of the discharge port 40b. In accordance with this, the binding roller SS is rotated in the G ₁ direction to bind the bookbinding sheet SS.
When the sheet detection switch SW ₃ is turned on and off, the conveyance near the discharge port 40b is detected, and the discharge tray 65
(S35). Then, after the transport unit 52 is moved downward and the discharge tray 65 is adjusted (S3
6) When a copy end signal is received from the control unit 68 (S37), end processing is performed (S38), and the staple (single) mode as described above is ended.

Next, in the staple (multi) mode, as shown in the flowcharts of FIGS. 10 to 14, when the number of staples is input, the control unit 68 receives the number of staples (S41) and sets the number of staples (S).
42). Next, when the post-processing device 40 receives the start signal from the control unit 68 (S43), the start process in the staple (multi) mode is performed (S4).
4) The number of processed sheets is cleared (S45).

After that, the sheet S on which the image of the original M is copied by the copying machine main body 1 is carried into the post-processing apparatus main body 40a through the carry-in port 41a, and when the main path 41c is passed, the sheet detection switch SW ₂ is turned on. When turned on (S46), the conveyance on the main path 41c is detected. Next, it is determined whether or not the sheet detection switch SW ₂ is turned off (S4).
7). If the seat detection switch SW _{2 is} still on,
As shown in FIG. 11, it is determined whether or not the bookbinding sheet SS has been discharged from the sheet receiving table 46 (S48).

The binding sheet S is still on the sheet cradle 46.
When S is not discharged, the transport unit 52 moves upward and the transport belt 55 rotates as described above, and the discharge rollers 53 rotate in the G ₁ direction, so that the bookbinding sheet SS is discharged to the discharge tray 65. Then, (S49), the process returns to S47 for carrying in the next sheet.

When the bookbinding sheet SS is discharged from the sheet receiving tray 46, it is judged whether or not the discharge tray 65 has been adjusted (S50). If the discharge tray 65 has been adjusted, the process directly returns to S47. If the discharge tray 65 has not been adjusted, the discharge tray 65 is adjusted (S5
1) and returns to S47.

When the sheet detection switch SW ₂ is detected to be off, the timer of the post-processing device 40 is cleared (S52), and the number of processed sheets S is counted up (S53). ).

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

When the sheet receiving tray 46 is prepared, the sheet S is transferred to the sheet receiving tray 4 by the discharge roller 43.
6 is discharged, and the process proceeds to S66. When the sheet receiving tray 46 is not prepared, the rotation of the discharge roller 43 is stopped and the conveyance of the first sheet S is stopped (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 conveyed to the bypass 41b is determined by the sheet detection switch SW.
It is determined by detecting the turning on of ₁ (S58). When the sheet detection switch SW ₁ has not been turned on yet, the bookbinding sheet SS is moved to the sheet receiving stand 46 as shown in FIG.
Then, it is determined whether or not it has been discharged (S59).

When the bookbinding sheet SS is not discharged from the sheet receiving tray 46, the bookbinding sheet SS is discharged to the discharge tray 56 by the transport unit 52 and the discharge roller 53 (S60), and the process returns to S58. When the bookbinding sheet SS is discharged from the sheet receiving tray 46, it is determined whether the discharge tray 56 has been adjusted (S61).

If the discharge tray 65 has been adjusted, the process directly returns to S58. If the discharge tray 65 has not been adjusted, the discharge tray 65 is adjusted (S62) and the process returns to S58.

When the sheet detection switch SW ₁ is detected to be on, the sheet detection switch SW ₁ is then detected to be off (S63), causing the deflector 44 to move to the B position.
The conveyance path of the sheet S is switched to the main path 41c by being rotated in _two directions (S64), and the conveyance roller 4
3 is rotated, and the conveyance of the first sheet S is restarted (S65). At this time, 2 transferred to the bypass 41b
The first sheet S and the second sheet S are discharged by the discharge roller 42, and the sheet receiving base 4
6 are discharged simultaneously.

Then, the process returns to S52 again, and the post-processing device 40
The timer is cleared (S52), the number of processed sheets is counted up (S53), and when it is determined that the number of processed sheets is not the first sheet (S54), the sheet S is discharged from the sheet receiving tray by the discharge roller 43. It is discharged to FIG.
As described above, it is determined whether or not the predetermined time set by the timer has elapsed (S66). Then, after a lapse of a predetermined time, the sheets S on the sheet receiving tray 46 are aligned in the width direction by the widthwise plate 47 (S67), and 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, the process returns to S46 and the conveyance of the sheet S on the main path 41c is detected. On the other hand, if the number of processed sheets matches the number of staples, the number of processed sheets is cleared (S69).
Next, the sheet S on the sheet receiving table 46 is rotated in the C direction of the paddler 48 and the rotation of the discharge roller 53 in the G ₂ direction so that the lower end of the sheet S abuts the stopper 50 and is aligned in the conveying direction. At the same time, the staples of the stapler 49 are bound and stapled (S70), and then the process returns to S46 to detect the conveyance of the sheet S on the main path 41c.

When the sheet S is no longer detected by the sheet detection switch SW _2, it is determined whether or not the bookbinding sheet SS has been discharged as shown in FIG. 14 (S7).
1). If the bookbinding sheet S is not yet discharged from the sheet receiving tray 46, the bookbinding sheet SS is discharged by the transport unit 52 and the discharge rollers 53 as described above.
(S72), and the process returns to S46 again. When the bookbinding sheet SS is discharged from the sheet receiving tray 46, it is determined whether the discharge tray 65 has been adjusted (S).
73).

If the discharge tray 65 has not been adjusted, the discharge tray 65 is adjusted (S74) and the process returns to S46.
When the discharge tray 65 has been adjusted, it is determined whether the post-processing device 40 has received the copy end signal from the control unit 68 (S75). If the signal end is not received, the process returns to S46 again. When the end signal is received, end processing is performed (S76), and the staple (multi) mode as described above is ended.

Further, the sheet post-processing apparatus 40 of this embodiment
Then, in the staple (multi) mode, if the sheet detection switch SW ₁ is not detected to be turned on (S58) within a predetermined time from the timer clear (S52), the rotation of the conveyance roller 43 is automatically restarted, Only the first sheet S is discharged onto the sheet receiving tray 46 without waiting for the synchronous discharge with the second sheet S.

As described above, in the case where the sheet post-processing device 40 performs bookbinding for a plurality of copies, the copying machine main body 1 is operated while the predetermined bookbinding processing is performed on the first sheet S on the sheet receiving stand 46. The next first sheet S ₁ conveyed from the side is conveyed by the main path 41c, and thereafter, the rotation of the conveyance roller 43 is stopped, so that the conveyance of the sheet S ₁ is temporarily stopped. Next, by switching the deflector 44, the second sheet S ₂ is conveyed by the bypass 41b.

Then, by restarting the rotation of the transport roller 43, the transport of the first sheet S ₁ is restarted, and the sheet pedestal 46 on which the discharge of the first bound sheet SS is completed.
First, the first sheet S ₁ and the second sheet S ₂ are ejected in synchronization. Therefore, since the next sheet S is effectively conveyed even when the sheet S on the sheet receiving tray 46 is stapled, the post-processing work can be speeded up.

Further, since the conveyor belt 55 is projected from the upper surface of the sheet receiving base 46 when the bookbinding sheet SS is discharged, and is retracted after the bookbinding sheet SS is discharged, the bookbinding sheet SS is extruded as in the conventional case. Compared with the case where the next sheet S cannot be conveyed onto the sheet receiving stand 46 unless the pushing member is surely returned to the original position after being pushed out,
Immediately after the bookbinding sheet SS is conveyed, the next sheet S can be conveyed onto the sheet receiving tray 46. Therefore, the efficiency of the post-processing work is improved.

Further, since the protrusion-shaped friction portion 59 is provided on the surface of the conveyor belt 55, the bookbinding sheet SS does not slip and the conveyor belt 55 does not run idle, so that it can be reliably discharged.

The present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention. For example, a plurality of transport units 52 may be provided, and these may be brought into contact with the lower surface of the bookbinding sheet SS to transport the bookbinding sheet SS. In addition, as a switching unit for switching the posture of the transport unit 52,
A cam or solenoid may be used.

[0065]

According to the present invention, when the sheet on the sheet receiving tray is discharged, the conveyor belt protrudes from the upper surface of the sheet receiving tray and is retracted after the sheet is discharged. For this reason, the next sheet can be conveyed onto the sheet receiving base immediately after the sheet is discharged, and the efficiency of the post-processing work is improved.

According to the second aspect, since the friction portion is provided on the surface of the conveying belt, there is an excellent effect that the sheet can be surely discharged without slipping during conveyance.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a sheet ejection mechanism showing an embodiment of the present invention.

FIG. 2 is a partial sectional view of a conveyor belt.

FIG. 3 is a configuration diagram showing a switching unit of a transport unit.

FIG. 4 is a block diagram of a copying machine equipped with a post-processing device.

FIG. 5 is a configuration diagram of a sheet post-processing device.

FIG. 6 is a layout view of each sheet detection switch in an offset mode of the sheet post-processing apparatus.

FIG. 7 is a layout view of each sheet detection switch in a staple mode of the sheet post-processing apparatus.

FIG. 8 is a flowchart showing an operation process of the sheet post-processing apparatus in the offset mode.

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

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

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

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

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

FIG. 14 is a flowchart showing an operation process of the sheet post-processing apparatus in the staple (multi) mode.

FIG. 15 is a configuration diagram of main parts of a conventional sheet discharging mechanism.

[Explanation of symbols]

 S sheet 46 sheet cradle 55 transport belt 58 switching means 59 friction portion 65 discharge tray

Claims (2)

[Claims] 1. In a sheet discharging mechanism for discharging a sheet on a sheet receiving tray to an output tray, a conveying belt for conveying the sheet is provided on the sheet receiving tray, and the conveying belt is provided from an upper surface of the sheet receiving tray. A sheet discharging mechanism, which is provided with a switching unit that is switchable between a projecting posture that projects upward and a sheet receiving posture that is recessed below the upper surface of the sheet receiving table, and that switches the posture of the transport belt. . 2. The sheet discharging mechanism according to claim 1, wherein a friction portion for increasing a frictional force with the sheet is provided on an upper surface of the conveying belt.