JP6552339B2 - Sheet processing apparatus and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a processing apparatus that processes a sheet conveyed from an image forming apparatus such as a copying machine or a printer, and more particularly to an improvement of a sheet processing apparatus that enables stable sheet conveyance when conveying sheets to different trays. .

  Generally, a processing apparatus is widely known which performs binding by collating sheets discharged from an image forming apparatus. There is also known an apparatus for receiving a sheet in a tray at a different position and binding the end face of the sheet, or a saddle stitching process for binding the approximate center of the sheet conveyance direction, and stopping conveyance of subsequent sheets as much as possible. It is also shown that the preceding sheet in the apparatus waits and stays in the apparatus without being carried and is conveyed to the tray together with the subsequent sheet.

  For example, Patent Document 1 shows a straight path that guides a sheet sent from an image forming apparatus to a first tray, and a branch path that branches from this path and guides it to a second tray. The first tray is provided with an end-face binding unit for binding to the end face of the sheet, and the second tray is provided with a saddle-stitching unit for binding the middle of the sheet in the conveyance direction.

Then, in the same document, in order to secure time for binding processing and the like in the first tray, so-called standby conveyance is performed in which the subsequent sheet is temporarily switched back to the above branch path and made to stand by and conveyed together with the subsequent sheet. Is shown. In order to receive the sheet in the second tray, the sheet is once transported to the first tray side, then switched back to the branch path, and transported through the branch path. As described above, by using the branch route branched from the transport route as the standby route or as the delivery route route to the second tray, the route becomes compact and processing can be performed without stopping the subsequent sheet.

Japanese Patent No. 5248785

The present invention, when you send switchback transportable to different trays, and to provide a small device with server data Tsukuko the sheet over preparative and Problems.

The present invention adopts the following configuration in order to solve the above problems.
A transport path for receiving the sheet and transporting the sheet to the first tray; a branch path for branching from the transport path to transport the sheet to the second tray; and a downstream side of the branch position between the transport path and the branch path. A first transport roller located in the transport path and capable of transporting the sheet in either direction of the first tray or the branch path, and a sheet located in the above branch path transport the sheet in any direction of the second tray or the transport path A possible second transport roller, and a controller for controlling the first transport roller and the second transport roller,
The control unit performs switchback conveyance after the sheet conveyed on the conveyance path passes through the branch position, and temporarily conveys the sheet to the first tray along with the subsequent sheet, and conveys the conveyance path. To carry out the second tray conveyance which carries out the switchback conveyance after passing the branch position and conveys it to the second tray via the branch path, and the switchback conveyance speed at the time of this second tray conveyance and the switch at the time of standby conveyance It is a sheet processing apparatus which makes the back transport speed different.

According to the present invention, when you send switchback transportable to different trays, it can provide little device with server data Tsukuko the sheet over and.

1 is an explanatory diagram showing an overall configuration in which an image forming apparatus and a sheet processing apparatus according to the present invention are combined. 1 is an overall explanatory view of a sheet processing apparatus including an end face binding unit and a saddle stitching unit according to the present invention. FIG. Explanatory side explanatory drawing of an end surface binding part periphery. Drive explanatory drawing of a conveyance roller, an exit roller, and a branching roller. Explanatory drawing of the raising / lowering mechanism of a 1st discharge tray, and an raising / lowering stop position. FIG. 6A is an explanatory diagram of a standby conveyance operation for a sheet to be stored in the first processing tray, and FIG. 6A is an explanatory diagram for starting switchback in the conveyance path. FIG. 6B is an explanatory diagram of a state in which the transfer is continued from the transfer route to the branch route. FIG. 7A is an explanatory diagram of the standby conveyance operation subsequent to FIG. 6, and FIG. 7A is an explanatory diagram in which the preceding sheet is made to wait on the branch path and the next sheet is carried in. FIG. 7B is an explanatory diagram in which the conveyance of the next sheet and the waiting preceding sheet is continuously started. FIG. 8A is an explanatory diagram of the standby conveyance operation following FIG. 7, and FIG. 8A is an explanatory diagram of a state in which the preceding sheet and the next sheet are combined and stored in the first processing tray. FIG.8 (b) is state explanatory drawing which carries in the 3rd sheet | seat succeedingly. FIG. 9 is an explanatory view of a second tray conveyance operation for storing sheets in a stacker (second processing tray) for saddle stitching processing, and FIG. 9A is an explanatory view of starting switchback in a conveyance path. FIG. 9B is an explanatory diagram illustrating a state in which switchback conveyance is continued at a low speed from the conveyance path to the branch path. FIG. 10A is an explanatory diagram of the second tray conveying operation subsequent to FIG. 9, and FIG. 10A is an explanatory diagram in which the preceding sheet conveys the branch path and receives the next sheet to perform the passing conveyance. FIG. 10B is an explanatory view in which the preceding sheet is stored in the stacker (second processing tray) and the next sheet is conveyed. Flow explanatory drawing which changes switchback speed by end face binding or saddle stitching. FIG. 12 is a flow explanatory view for checking the sheet size and changing the speed in end face binding and saddle stitching in the modification of FIG. 11; Explanatory drawing of the control structure in the whole structure of FIG.

  The present invention will be described in detail on the basis of the preferred embodiments of the present invention shown below. FIG. 1 is an overall configuration diagram showing an image forming system including an image forming apparatus A and a sheet processing apparatus B according to the present invention, and FIG. 2 is an explanatory diagram of a detailed configuration of the sheet processing apparatus B.

[Configuration of image forming system]
The image forming system shown in FIG. 1 includes an image forming apparatus A and a sheet processing apparatus B. Then, the carry-in port 30 of the sheet processing apparatus B is connected to the main body discharge port 3 of the image forming apparatus A, and the sheet on which the image is formed by the image forming apparatus A is stapled by the sheet processing apparatus B and the first sheet discharge tray 24 or It is configured to be stored in the second paper discharge tray 26. Further, above the first sheet discharge tray 24, an escape tray 22 for directly storing sheets without performing binding processing is disposed.

[Configuration of Image Forming Apparatus A]
The image forming apparatus A will be described according to FIG. The image forming apparatus A is configured to send a sheet from the sheet feeding unit 1 to the image forming unit 2, print it on the sheet by the image forming unit 2, and then discharge the sheet from the main body discharge port 3. The sheet feeding unit 1 stores sheets of a plurality of sizes in sheet feeding cassettes 1 a and 1 b, and separates specified sheets one by one and feeds them to the image forming unit 2.

In the image forming unit 2, for example, an electrostatic drum 4, a print head (laser light emitter) 5 and a developing device 6 disposed around the electrostatic drum 4, a transfer charger 7 and a fixing device 8 are disposed. The image forming unit 2 forms an electrostatic latent image on the electrostatic drum 4 with the laser light emitting device 5, adheres the toner to this with the developing device 6, transfers the image onto the sheet with the transfer charger 7, and fixes the device In step 8, the image is formed by heat fixing. The sheets on which images are formed in this way are sequentially carried out from the main body discharge port 3. Indicated by 9 is a circulation path, which reverses the sheet printed on the front side from the fixing device 8 through the switchback path 10 and feeds it again to the image forming unit 2 to print on the back side of the sheet. This is the print path. The sheet printed on both sides in this manner is turned over in the switchback path 10, and is then discharged from the main body discharge port 3.

  11 is an image reading apparatus, which scans a document sheet set on a platen 12 with a scanning unit 13 and electrically reads it with a photoelectric conversion element (not shown). The image data is digitally processed by an image processing unit, for example, and then transferred to the data storage unit 14 to send an image signal to the laser emitter 5. Further, an illustration 15 is a document feeding device, which feeds a document sheet stored in a document stacker 16 to a platen 12.

  An image forming control unit 200 shown in FIG. 12 is provided in the image forming apparatus A configured as described above, and image forming conditions such as sheet size designation, color / monochrome printing designation, number of copies are provided from the control panel 18 via the input unit 203. Printing conditions such as designation, single-sided / double-sided printing designation, and enlargement / reduction printing designation are set. In the image forming apparatus A, image data read by the scan unit 13 or image data transferred from an external network is accumulated in the data storage unit 17. The image data is transferred from the data storage unit 17 to the buffer memory 19, and the data signal is transferred from the buffer memory 19 to the laser emitter 5 sequentially.

  From the control panel 18, sheet processing conditions are also input and specified simultaneously with the image forming conditions such as single-sided / double-sided printing, enlargement / reduction printing, and monochrome / color printing described above. As the sheet processing conditions, for example, “printout mode”, “end surface stitching mode”, “saddle stitching mode” or the like is set. These processing conditions will be described later.

[Configuration of Sheet Processing Apparatus B]
As shown in FIG. 1 and FIG. 2, the sheet processing apparatus B accumulates a sheet carry-in port 30 provided on one side of the apparatus frame 20 and a single sheet or a relatively thick sheet provided on the opposite side. An escape tray 22 is disposed. Below the escape tray 22 is a first dischargeable tray 24 capable of moving up and down for stacking end-face-stitched sheets and sheets having a relatively large amount. Further, below the first paper discharge tray 24, there is provided a second paper discharge tray 26 for collecting the saddle stitched or folded sheets. In the present invention, the end surface indicates the surface around the end of the sheet, that is, the front and back surfaces of the sheet edge.

[Sheet conveyance path 42, etc.]
A conveyance path 42 extending substantially linearly from the carry-in path 32 to the first processing tray outlet 50 is disposed from the carry-in entrance 30 of the sheet processing apparatus B. A punch unit 31 is provided in the carry-in path 32, and punch processing is carried out in the middle of the transport direction as needed for the end face of the sheet. A punch scrap box 31 b for accumulating punch scraps generated at the time of the punching process is provided below the sandwiching path 32 of the punch unit 31 so as to be removable from the apparatus frame 20.

  A carry-in roller 34 for conveying the sheet is disposed downstream of the punch unit 31 to convey the sheet at a high speed. The conveyance path 42 on the downstream side of the carry-in roller 34 is provided with a conveyance roller 44 capable of rotating in the forward and reverse direction for guiding the sheet to the first processing tray 54 which is the first tray and the first paper discharge tray 24 on the downstream side. Yes. The rear of the transport roller 44 is a sheet transport path outlet 46.

On the downstream side of the conveyance path outlet 46, an outlet roller 48 capable of forward and reverse rotation is provided. The exit roller 48 switches back the sheet and conveys the sheet to the first processing tray 54, discharges the sheet straight to the first discharge tray 24, or is stacked on the first processing tray 54 and end-face binding processing. The bundle of sheets is discharged onto the first discharge tray 24.

[Escape route, branch route]
Further, the transport path 42 guides the sheet to the escape tray 22 and guides the stacker 84 (which is also the second processing tray) to be a second tray for saddle stitching and folding a relatively long sheet. The branch path 70 is branched at a branch position 36. A path switching gate for selecting whether the sheet is conveyed to the conveyance path 42 as it is to the branch position 36, conveyed to the escape path 38, or switched back on the conveyance path 42 and guided to the branch path 70. 37 are provided.
The escape path 38 is provided with an escape roller 39 for conveying the sheet and an escape outlet roller 40 for discharging the sheet to the escape tray 22.

[End face binding section 60]
By the way, the first processing tray 54 is provided below the transport path outlet 46 of the transport path 42, and at the lower end side thereof, the end face binding portion 60 for binding the end face of the sheet temporarily accumulated on the first processing tray 54 is positioned. doing. The end face binding portion 60 will be described later with reference to FIG.
[Saddle stitching section 80]
On the other hand, a relatively long sheet is once transported along the transport path 42 toward the first processing tray 54 and transported to the downstream side of the switching gate 37, and then switched back and transported to the branch path 70 for branch exit. 76 to stacker 84 (second tray). As shown in FIG. 2, each time a sheet is carried into the stacker 84 from the branch outlet roller 74, the sheet is biased to the left side in the figure at the branch outlet 76 to prevent collision between the trailing end of the preceding sheet and the leading end of the next sheet. A flapper 78 is provided.

[Stacker (second processing tray / second tray) 84 and its surroundings]
The stacker 84 is provided with a stopper 85 that defines a sheet carry-in position. The stopper 85 is moved in the direction of the arrow by driving the moving belt 88 stretched between the upper pulley 86 and the lower pulley 87 on the side of the stacker 84 by the stopper moving motor 85M. The position of the stopper 85 is a position where the rear end of the sheet can be changed by the change flapper 78 when the sheet is carried into the stacker 84, a position where the saddle stitching unit 82 performs saddle stitching at the approximate center of the sheet conveyance direction, The saddle-stitched position is pushed by a folding blade 94 that reciprocates to the pair of folding rollers 92 and stopped at a position where the sheet bundle is folded in half.
Further, on the upper and lower sides of the folding roller 92, a saddle stitching alignment plate 81 is provided which performs the aligning operation by pressing the side edges of the sheet from the sheet width direction each time the stacker 84 of the sheet is carried in.

[Saddle stitching unit 82]
The saddle stitching unit 80 is provided with an anvil 83 provided for driving a bundle of sheets, for example, a staple by a driver in the saddle stitching unit 82, and provided at a position opposite to this to bend a leg portion of the staple. Since this saddle stitching unit 82 is already widely known, the description thereof is omitted here, but as a binding means, not only staples are pierced through the sheet bundle to be stapled, but an adhesive is provided at the center in the sheet conveyance direction. It may be a mechanism that coats and pastes the sheets into a bundle.

[Around the second discharge tray 26]
The sheet bundle stapled by the above-described saddle stitching unit 82 is folded in half by the folding roller 92 and the folding blade 94 which pushes the sheet bundle into the sheet bundle, and the bundle discharging roller 96 located downstream thereof Thus, the sheet is discharged to the second sheet discharge tray 26. The second sheet discharge tray 26 is provided with a rotatable roller at the leading end for causing the second sheet discharge tray 26 to drop the folded sheet bundle which is folded and discharged with the back side as the leading end side, and a swingable pressing roller 102, and a presser lever 104 that is pressed from above so that the bundle of folded folded sheets does not spread. The folded sheet bundle is opened by the pressing roller 102 and the pressing lever 104, and the decrease in the accumulation property is reduced.

[About bifurcation position 36, end face binding section 60]
Here, the branch position 36 and the end surface binding portion 60 will be further described with reference to FIG. As described above, here, the carry-in path 32 in which the carry-in roller 34 is disposed from the carry-in port 30, the transport path 42 linearly extending from the transport path 42 toward the first processing tray 54, and the escape path extending upward from the transport path 42 38 and a branch path 70 that curves downward and guides the sheet to the stacker 84 is shown. At the branch position 36, the change flapper 78 selectively guides the sheet carrying the sheet in the carry-in path 32 to the escape path 38 or the conveyance path 42, or switches back and conveys the conveyance path 42 to the branch path 70. It is arranged.

In this embodiment, for example, as shown in FIG. 3, the escape path 38 is closed at the solid line position to guide the sheet from the carry-in path 32 to the transport path 42, and the carry-in path at the broken line position. It is shown that the sheet conveyed from 32 is guided to the escape path 38, and the sheet that is switched back along the conveyance path 42 is guided to the branch path 70.

  In the transport path 42 described above, a transport roller 44 that rotates in the forward and reverse directions and is in contact with and away from each other is disposed immediately before the transport path exit 46 that is the final end. That is, the conveyance roller 44 can convey the sheet to the first processing tray 54 side by one-way rotation with the pressure contact state, and switchback conveyance in the opposite direction by the other rotation.

[About switchback transport]
The switchback conveyance is performed by rotating the conveyance roller 44 after the sheet sensor 42S disposed immediately after the switching gate 37 of the conveyance path 42 detects the passage of the rear end of the sheet. At the time of this other rotation, the switching gate 37 has moved to the position (the broken line position in FIG. 3) closing the carry-in path 32, whereby the sheet is conveyed to the branch path 70 and taken over by the branch roller 72. When the trailing end reaches a predetermined position, the branch roller 72 is stopped, and the sheet is placed in a standby state on the branch path 70.

  By the way, at the downstream side of the transport roller 44 and at the first processing tray outlet 50 (the outlet of the first processing tray 54), an outlet roller 48 which rotates forward and reverse and is separated from each other is disposed. The outlet roller 48 includes an outlet upper roller 48a and an outlet lower roller 48b, which cooperate with the transport roller 44 to rotate the sheet in the first sheet discharge tray 24 by one-way rotation in a pressure contact state. Transport. In addition, the exit roller 48 is also used when discharging the sheets accumulated in the first processing tray 54 as a bundle to the first sheet discharge tray 24 in cooperation with the movement of the reference surface 57 described later.

[Collection on first processing tray 54]
Here, the accumulation of sheets on the first processing tray 54 will be described. In the accumulation on the first processing tray 54, the sheet discharged from the conveying roller 44 is conveyed to the right side in FIG. 3 by the other rotation of the outlet roller 48 positioned on the downstream side. The conveyed sheet is transferred by rotating the squeezing roller 56 around which the projection belt 146 is wound in the counterclockwise direction in the drawing. By this transfer, the front end of the sheet in the conveyance direction comes into contact with the reference surface 57 serving as a binding reference for the other surface and stops. At this time, the scraping roller 56 slides on the sheet and prevents the sheet tip from buckling after contacting the reference surface. That is, the outlet roller 48 has a function of switchback conveying the sheet discharged from the conveying roller 44 and feeding the sheet to the reference surface 57 of the first processing tray 54.

[Movement of End Stitching Unit 62 and Stitching Process]
When the sheet is discharged from the conveying roller 44, the sheet is sent to the reference surface 57 and stacked on the first processing tray 54 by the rotation of the exit roller 48 and the scooping roller. In accordance with this stacking operation, the aligning plate 58 is brought into contact with both sides in the sheet width direction to align the sheet with the center in the width direction of the first processing tray 54. This process is repeated until the designated number of stacks and alignments are bundled. When the designated number is reached, the end face binding unit 62 that moves the end face of the sheet in the sheet width direction on the moving table 63 is moved to a desired binding position. This movement is made by guiding the moving pin 62b of the end face binding unit 62 into the illustrated groove rail provided on the moving base 63 in the sheet width direction.

Since the binding process of the end face binding unit 62 is already known, the description is omitted, but when the end face binding unit 62 stops at the specified binding position, the end face binding motor 62M is rotationally driven to move a driver (not shown) to staple The staples are driven into a bundle of sheets, and the staple needles that have been driven are folded by an anvil and bound. This binding process is performed at a plurality of positions on the end face of the sheet corner and the end face in the width direction.

[Delivery of edge-bound sheet]
The sheet bundle that has been subjected to the binding process by the end face binding unit 62 is moved by the reference surface moving belt 64 spanned by the right pulley 65 and the left pulley 66 below the first processing tray 54 in the counterclockwise direction in FIG. The reference surface 57 connected to the belt 64 moves in the left direction in the figure, thereby pushing out the binding end surface side of the sheet bundle toward the first paper discharge tray 24. At the same time, the sheet bundle bound by the exit roller 48 disposed at the outlet of the first processing tray 54 is pressed from the front and the back, and the sheet bundle bound to the first sheet discharge tray 24 is discharged by the clockwise rotation.

[Raising and lowering the first discharge tray 24]
The first paper discharge tray 24 for collecting the sheet bundle will be described. As shown in FIG. 3, the first sheet discharge tray 24 is disposed at substantially the same angle of inclination as the first processing tray 54, and the bundle of bound sheets discharged from the first processing tray 54 and the conveyance roller 42 from the conveyance path 42. The sheets discharged by the exit roller 48 are also collected.
An elevation motor 24M for raising and lowering the first sheet discharge tray 24 is provided on the bottom surface side of the first sheet discharge tray 24, and this drive is transmitted to the elevation pinion 109. The raising and lowering pinion 109 engages with a raising and lowering rack 107 fixed on the both sides of the rising surface 28 of the apparatus frame 20 at the top and bottom. Although not specifically shown, the elevator rail is guided up and down by an elevating rail provided on the standing surface 28 of the first paper discharge tray 24.

The position of the first paper discharge tray 24 or the position of the sheets stacked on the first paper discharge tray 24 is detected by a paper surface sensor 24S provided on the standing surface 28. And when this paper surface sensor 24S detects, the raising / lowering motor 24M will be driven and the raising / lowering pinion 109 will rotate and it will descend | fall. In the state of FIG. 3, the upper surface of the first paper discharge tray 24 is detected by the paper surface sensor 24S, and the sheet bundle is lowered slightly from here to accept the sheet bundle. Therefore, the upper surface of the exit position from the first processing tray 54 and the upper surface of the first sheet discharge tray 24 are positioned with a level difference.

Next, the configuration of rotational driving and separation / contact of the conveying roller 44 and the outlet roller 48 will be described with reference to FIG.
[Rotational Drive of the Transport Upper Roller 44a]
First, driving of the transport roller 44 including the transport upper roller 44a and the transport lower roller 44b is performed by a transport roller motor 44M. The transport roller motor 44M is composed of a hybrid type stepping motor, and a speed detection sensor 44S for detecting the rotational speed of the motor shaft is disposed. The drive of the transport roller motor 44 M is transmitted to the arm gear 126 via the transmission gears 120 and 122 and the transmission belt 124. The drive from the arm gear 126 is transmitted by the transfer belt 128 to the upper roller shaft 44 u j of the upper transport roller 44 a supported by the transport roller support arm 136.

[Detaching of Conveying Upper Roller 44a]
Further, the transport upper roller 44a is attached so as to be rotated about the axis of the arm gear 126 so as to be separated from and in contact with the fixed transport lower roller 44b. This separation is performed by the conveyance roller movement arm 130 which has a rear sector gear attached to the shaft of the arm gear 126 and a spring 134 for biasing the conveyance upper roller 44a attached to the tip of the movement arm on the tip side. That is, by driving the transport roller moving arm motor 130M engaged with the above-mentioned rear sector gear forward and reversely, the arrow is brought into pressure contact with the transport lower roller 44b of the arrow C in the release direction of the arrow O by one rotation. It moves in the pressure contact direction of C. The transport roller moving arm motor 130M is also constituted by a stepping motor, and the position of the transport roller moving arm 130 is detected by the transport roller moving arm sensor 130S.

[Rotational drive of lower roller 44b etc.]
The rotational driving of the lower conveying roller 44 b is performed by transmitting the driving of the conveying roller motor 44 M via the transmission gear 120 and the transmission belt 138 by transmitting the receiving gear 142 individually provided on the lower conveyance roller shaft 44 sj.
Further, the driving from the receiving gear 142 rotates the roller 56 by driving the gear 144 with a one-way clutch and the belt 146 with a projection that also functions as a transmission belt. Since the scraping roller 56 is transmitted through the one-way clutch gear 144, even if the receiving gear 142 rotates forward or reverse as described above, it rotates only in the direction of the solid line arrow in FIG. It is transferred only in the direction of the reference surface 57 of the processing tray 54.
The drive of the conveyance roller motor 44M is also transmitted to the lower branch roller shaft 72sj of the lower branch roller 72b of the branch roller 72 that conveys the sheet in the branch path 70 via the transmission gear 120 and the transmission belt 148.

[Speed setting of conveyance roller motor 44M]
With the above configuration, according to the forward and reverse rotation of the transport roller motor 44M, the transport roller 44 and the branch roller 72 move in one direction of the solid line arrow in the drawing and in the other direction (switchback direction) in the dashed arrow direction. Rotate in the direction of the reference plane 57 of Further, the conveyance roller motor 44M is about 1100 mm / s when conveying the sheet to the first processing tray 54 side, and about 1100 mm / s or lower when conveying switchback to the branch path 70 side. It can be arbitrarily set so that the sheet can be conveyed at a speed of about 600 mm / s. This speed is from the start to the rotation setting speed, and the average speed is lower than this setting value, but in any case, the sheet conveyance direction, sheet length, conveyance speed in the conveyance mode of standby conveyance or second tray conveyance, etc. Is variable. This speed setting will be described later.

[Rotary drive of outlet upper roller 48a]
The exit roller 48 comprising the exit upper roller 48a and the exit lower roller 48b is driven by the exit roller motor 48M. The outlet roller motor 48M is also formed of a hybrid stepping motor, and a speed detection sensor 48S for detecting the rotational speed of the motor shaft is also disposed in the same manner. The drive of the exit roller motor 48M is transmitted to the exit arm gear 156 via the transmission gears 150 and 152 and the transmission belt 154. The drive from the outlet arm gear 156 is transmitted by the transmission belt 158 to the outlet upper roller shaft of the outlet upper roller 48 a supported by the outlet roller support arm 166.

[Detaching of exit upper roller 48a, etc.]
The outlet upper roller 48a is attached so as to be rotated around the axis of the outlet arm gear 156 so as to be in contact with and away from the fixed lower outlet roller 48b. This disengaging is performed by the outlet roller moving arm 160 having a rear sector gear attached to the shaft of the outlet arm gear 156 and having a spring 164 attached to the tip moving arm tip to bias the outlet upper roller 48a. . By driving the outlet roller moving arm motor 160M engaged with the above-mentioned rear sector gear forward and reversely, the arrow C is pressed against the outlet lower roller 48b of the arrow C in the releasing direction of the arrow O by one rotation. Move in the pressure contact direction. The exit roller moving arm motor 160M is also constituted by a stepping motor, and the position of the exit roller moving arm 160 is detected by the exit roller moving arm sensor 160S.
Further, the rotational drive of the outlet lower roller 48 b is performed by transmitting the drive of the outlet roller motor 48 M to the receiving gear 169 individually provided on the outlet lower roller shaft 48 sj via the transmission gear 150 and the transmission belt 168.

[Speed setting of outlet roller motor 48M]
With the above configuration, as the outlet roller motor 48M rotates in the forward and reverse directions, the outlet roller 48 is directed in one direction indicated by the solid line arrow in the figure and in the other direction indicated by the broken line (on the first processing tray 54 after the sheet is In the direction of switchback to the reference surface 57). Further, the exit roller motor 48M is about 1100 mm / s in the case of taking over from the conveying roller 44 and about 600 mm / s in the case of switchback conveying in the direction of the takeover reference surface, and the sheet bundle of the first processing tray 54. Is discharged to the first paper discharge tray 24 in cooperation with the movement of the reference surface 57, it can be set so that the sheet can be conveyed at a speed of about 300 mm / s. That is, the outlet roller motor 48M can set the speed in the range of about 1100 mm / s to about 300 mm / s.
In this embodiment, when the sheet conveyance is performed by the conveyance roller 44 at the time of switchback conveyance in the case of standby conveyance, since the drive motor is separated and interlocking is difficult, the outlet upper roller 48a is an outlet. It is located at a separated position released from the lower roller 48b.

[Page sensor 24S of first discharge tray 24]
The elevation mechanism of the first sheet discharge tray 24 has already been described with reference to FIG. 3, but the setting of the elevation position will be described with reference to FIG. The elevation position is set by detecting the surface of the sheet sensor 24S or the upper surface of the first sheet discharge tray 24. The sheet sensor 24S detects the sensor flag 24f rotatably supported at one end. Is called. Further, an empty sensor 25 for detecting whether or not a sheet is placed is provided on the surface on which the first paper discharge tray 24 is placed. Therefore, when the empty sensor 25 is ON, the sheet sensor 24S detects the upper surface of the sheet. When the empty sensor 25 is OFF, the height of the mounting surface on which the sheet is not mounted is detected. Will be.

[Elevation position setting of first discharge tray 24]
By the way, when the sheet bundle is discharged from the first processing tray 54, the elevating surface of the first sheet discharge tray 24 is set so that the loading surface or the paper surface is positioned at 24 Sm position of L1 + L2 distance shown in FIG. It is. When the sheets are discharged one by one, the sheet is raised so that the placement surface or the paper surface is positioned at the 24Sh position of the L1 distance which shortens the falling range of the sheets. Further, when the sheet to be switched by the conveyance roller 44 is short, or when the sheet is switched back so as to make the branch path 70 stand by for edge binding, the leading end of the sheet to be switched back is attached to the first sheet discharge tray 24. The position is lowered to the 24SL position of the L1 + L2 + L3 distance so as not to touch the sheet or the mounting table placed.
Furthermore, when the sheet to be switched back by the conveyance roller 44 is long or when the sheet is switched back to be conveyed to the branch path for saddle stitching, it is possible to suppress bending or fluttering of the leading end of the sheet to be switched back. In order to guide, the ascending setting is also performed so that the placing surface or the paper surface is positioned at the 24 Sh position of the L1 distance that shortens the step range.

Here, a description will be given of the standby conveyance in which the switchback conveyance is carried out for the end face binding described above and the branch path 70 stands by. When the end processing unit 54 performs the binding process on the first processing tray 54, the sheet forming speed of the image forming apparatus A is high, and the sheet interval is short. It is necessary to prevent the next sheet from being carried in even if it is not completed. For this reason, the first or second sheet of the sheet conveyed to the conveyance path 42 via the carry-in path 32 is temporarily switched back on the conveyance path 42, and the switchback conveyed sheet is retained on the branch path 70. It is being made to wait. Then, the sheet waiting in the branch path 70 is fed out so as to be superimposed and fed to the next second or third sheet, and the interval time between the sheet bundle is secured. (This is disclosed in FIG. 10 of Japanese Patent No. 5248785, which is cited as reference 1.)

In the present invention, the switchback transport is performed from the transport path 42 to the branch path 70, and one or more sheets are held in the branch path 70 and made to stand by, and the next sheet of the waiting sheets is fed out and carried out. It is defined as “transport”. The sheet for end face binding which carries out this waiting conveyance has many sheets of relatively short length in the conveyance direction, for example, each size sheet of A4, B5, and letter. Therefore, the switchback transport of these sheets is performed without largely sticking out to the downstream side of the first processing tray 54 for standby transport, and the sheet is hardly bent during this transport. Even if it is bent slightly, the distance to the first processing tray 54 is relatively short, so that the bending is easily corrected by the alignment operation of the alignment plate 58.
In addition, completion of the above-mentioned end face binding processing is not only completion of discharging the sheet bundle from the first processing tray 54 to the first paper discharge tray 24 but also an initial setting operation of the alignment plate 58 on the first processing tray 54. And initial position return of the reference plane moving belt 64 or other initial position setting for receiving the next sheet.

Next, a case will be described in which saddle stitching is performed by the saddle stitching unit 82, and this sheet is conveyed to the stacker 84, which is a second processing tray, to be folded by the folding roller 92 and the folding blade 94 to form a folded sheet bundle. In the conveyance to the stacker 84, the sheet conveyed to the conveyance path 42 through the carry-in path 32 is temporarily switchback conveyed on the conveyance path 42, and the switchback conveyed sheet is conveyed to the stacker 84 from the branch path 70. become.

Conveying to the stacker 84 via the switch-branched sheet branch path 70 is herein defined as “second tray conveyance”. Since the middle surface binding sheet for carrying the second tray is folded in two, there are many sheets having a relatively long length in the carrying direction, for example, A3, B4 and legal size sheets. Therefore, the switchback transport for the second tray transport largely protrudes to the downstream side of the first processing tray 54 for the second tray transport, and bending or flapping occurs during switchback transport. Further, since the transport distance to the stacker 84 is relatively long in the second tray transport, the bend is amplified, and the bend may not be corrected even if it is aligned by the saddle stitch aligning plate 81.

In recent years, the sheet is conveyed at a very high speed as the speed of the image forming apparatus A increases, and considerable productivity is required particularly in end-face binding, so if this speed is applied to the second tray conveyance described above, sheet bending or fluttering occurs. Increases the date. Therefore, in the present invention, the switchback conveyance speed of the second tray conveyance is made slower than the switchback conveyance speed of the standby conveyance to suppress sheet bending or fluttering during the second tray conveyance.

Differences in speed at the time of switchback conveyance on the conveyance path 42 between the above-described standby conveyance and second tray conveyance will be described with reference to the sheet flowcharts of FIGS. 6 to 10 and the flowchart of FIG.
[Standby conveyance for end face binding]
First, according to FIGS. 6 to 8, the transport roller 44 is reversely rotated to stand on the branch path 70 in order to stack the sheet on the first processing tray 54 and bind the sheet bundle to the end face, and then transport the sheet to the first processing tray 54 again. The standby conveyance will be described.
6 to 8 take an example of A4 sideways used relatively frequently for end face binding as an example, SL is the distance from the sheet sensor 42S of the conveyance path 42 to the exit position of the exit roller 48 (first processing tray exit 50) Is shown. In this embodiment, SL is 120 mm to 130 mm. Accordingly, the sheet has a length slightly less than twice that of SL, and as shown in FIG.

First, FIG. 6A shows that the first sheet (sheet 1) for end-face binding is conveyed at about 1100 mm / s on the conveyance path, and the conveyance roller is detected when the sheet rear end is detected by the sheet sensor 42S. 44 temporarily stops, and this time switches the transport roller motor 44M to reverse to feed the sheet backward. At this time, the leading end side of the sheet is in a state of protruding about half as described above.

Next, as shown in FIG. 6 (b), prior to the reverse rotation of the transport roller motor 44M, the switching gate 37 is moved to the position shown by the solid line in advance. The sheet is conveyed toward the branch path 70 by the conveyance roller 44, and conveyed toward the downstream side of the branch path 70 by the branch roller 72 rotated by the conveyance roller motor 44M. The conveyance speed of the conveyance roller motor 44M at this time is also set to a high speed so as to convey the sheet at 1100 mm / s. Of course, since the conveyance roller motor 44M is temporarily stopped at the time of normal rotation and reverse rotation, the conveyance target speed of this 1100 mm / s is set, and the average speed becomes a little slower. It transports at high speed to make it in time.

  In FIG. 7A, when the rear end of the first sheet (sheet 1) that has been switchback conveyed reaches a position at which the next sheet (sheet 2) is not hindered at the branch position 36, the conveying roller motor 44M is stopped. As a result, the branch roller 72 also stops, and the preceding sheet waits on the branch path 70 to wait for the next sheet to be carried in. The next sheet (sheet 2) is transported from the transport path 32 toward the transport path 42 at 1100 mm / s by the transport roller motor 34M.

Subsequently, in FIG. 7B, prior to the arrival of the next sheet at the transport path 42, the switching gate 37 is moved to a position where the escape path is closed as shown in the drawing. As a result, the next sheet (sheet 2) is conveyed to the conveyance path 42. At the same time, the sheet is conveyed so as to be superimposed on the sheet (sheet 1) which has been waiting in the branch path 70. At this time, as shown in the drawing, the preceding sheet (sheet 1) is conveyed with a slight shift to the rear side with respect to the leading end of the next sheet (sheet 2). As shown in the following, when the uppermost sheet (sheet close to the scraping roller 56) is positioned far from the reference surface 57 when carried into the first processing tray 54, rotation of the scraping roller 56 causes a plurality of sheets with high accuracy. Are aligned on the reference surface 57.
When the two sheets are overlapped, both the carry-in roller motor 34M and the carry roller motor 44M are set to carry the sheet at the same speed with a carry arrival speed of 1100 mm / s.

  Next, the process proceeds to the state of FIG. 8A, and before the two overlapped sheets are discharged from the conveying roller 44, the outlet upper roller 48a of the outlet roller 48 descends toward the outlet roller 48b to remove the sheet. Nip. At this time, the exit roller 48 conveys at the same speed as the conveyance roller 44, and once the sheet is discharged from the conveyance roller 44, the sheet temporarily stops. After this stop, this time, the exit roller 48 is rotationally driven to the reference surface 57 side of the first processing tray 54. As a result, the two sheets (sheets 1 and 2) are conveyed on the mounting surface of the first processing tray 54 to the reference surface 57 side, and are continuously driven by the conveyance roller motor 44M via the one-way clutch gear 144. It is continuously conveyed by the roller 56. In addition, the conveyance to the reference surface 57 side of the exit roller 48 is easy to be aligned if the conveyance is decelerated from the rotation of 1100 mm / s to about 600 mm / s.

FIG. 8B shows a state in which the third sheet (sheet 3) is carried into the first processing tray 54. In this case as well, before the third sheet is ejected from the transport roller 44, the upper exit roller 48a is lowered and rotated in the same direction as the transport roller 44. On the contrary, it is transferred to the reference surface 57 side together with the scraping roller 56. This is repeated until the designated number of sheets is reached, and one bundle is generated, and after the binding processing is performed by the end face binding unit 62, the first sheet discharge tray 24 discharges the bundle.
As described above, in the standby conveyance for the end face binding in FIGS. 6 to 8, the switchback conveyance speed of the conveyance roller 44 is high-speed conveyance with the setting speed being 1100 mm / s.

[Second tray conveyance for saddle stitching]
Next, as shown in FIGS. 9 and 10, in order to stack the sheets on the stacker (second processing tray) 84 as the second tray and saddle-stitch the sheet bundle in the middle of the sheet conveyance direction, reverse the conveyance roller 44. The “second tray conveyance” sent to the stacker via the branch path 70 will be described.
In FIG. 9 and FIG. 10, the case of the A3 sheet which is used relatively often by saddle stitching is taken as an example, and the SL is the sheet sensor 42S of the conveyance path 42 to the exit position of the exit roller 48 (first processing tray exit 50) Indicates the distance of the eyebrow. In this embodiment, since SL is 120 mm to 130 mm, the sheet for saddle stitching is about three and a half times as long as this SL. As shown in FIG. Is in a state of sticking out of the aircraft.

First, FIG. 9A shows that the second tray is conveyed to the stacker 84 via the branch path 70 for saddle stitching, and the first sheet (sheet 1) is about 1100 mm / s on the conveyance path 42. When the rear end of the sheet is detected by the sheet sensor 42S, the conveyance roller 44 is temporarily stopped, and this time the conveyance roller motor 44M is switched to reverse so as to reverse the sheet. At this time, as described above, two thirds or more of the front end side of the sheet is out of the apparatus.

Next, as shown in FIG. 9B, prior to the reverse rotation of the transport roller motor 44M, the switching gate 37 is moved to the illustrated position. The sheet is conveyed toward the branch path 70 by the conveyance roller 44, and conveyed toward the downstream side of the branch path 70 by the branch roller 72 rotated by the conveyance roller motor 44M. The conveyance speed of the conveyance roller motor 44M at this time is also set to be changed to a low speed so as to convey the sheet by decelerating it by 600 mm / s.
Then, when the first sheet (sheet 1) is nipped by the bifurcating roller 72 rotating at the same speed of 600 mm / s, the switching gate 37 is at a position where the transport path 42 is released (a position at which the escape path is blocked). ) At the same time, the upper conveying roller 44a of the conveying roller 44 is separated from the lower conveying roller 44b and waits for the next sheet (sheet 2) to be carried.

Since the conveyance roller motor 44M is temporarily stopped at the time of normal rotation and reverse rotation, the above-mentioned 600 mm / s is set as the conveyance target speed, and the average speed is slightly slower. doing. Further, the speed is reduced from 1100 mm / s to 600 mm / s during the switchback conveyance. This is because, during switchback conveyance, which is the return conveyance of the sheet, there is much fluttering of the sheet, and since the sheet is conveyed over a relatively long distance, it is decelerated particularly during the return. As another embodiment, when the processing speed is not particularly required, the sheet to be switched back may be decelerated from 1100 mm / s to 600 mm / s in the reciprocating conveyance in which the sheet is discharged out of the apparatus.

Next, in FIG. 10A, the next sheet (sheet 2) is conveyed to the conveyance path 42 by the carry-in roller 34. In this case, since the transport roller 44 is in the separated state as illustrated, the first sheet (sheet 1) is transported by the branch roller 72 and the branch outlet roller 74 to the stacker 84 at 600 mm / s, and the next The second sheet (sheet 2) is conveyed at 1100 mm / s along the conveyance path 42 toward the first processing tray 54 side by the carry-in roller 34. In this case, the two sheets are conveyed while being passed in opposite directions (passed conveyance).
This passing conveyance is performed to reduce or reduce the waiting time of the next sheet in order to decelerate and convey the preceding sheet.

Then, in FIG. 10B, since the preceding sheet is separated from the branch roller 72 and stored in the stacker 84, the upper conveyance roller 44a is lowered to set the conveyance roller 44 in the nip state and the first sheet discharge tray 24 side. To convey the sheet at a speed of 1100 mm / s. Thereafter, the sheet is continuously conveyed in the state of FIG. 9A, and this is repeated until the designated number of sheets is reached, and is generated as one bundle in the stacker 84. Then, the sheet bundle is moved to the binding position of the saddle stitching unit 82 by the stopper 85 shown in FIG.
As described above, in the second tray conveyance for saddle stitching in FIGS. 9 and 10, the switchback conveyance speed of the conveyance roller 44 is decelerated conveyance with the setting speed of 600 mm / s, and the sheet is switched back. Reduce fluttering and bending.

Here, the standby conveyance in FIGS. 6 to 8 and the conveyance speed switching in FIGS. 9 and 10 described so far are confirmed by the flowchart in FIG. Further, another embodiment different from that described so far will be described with reference to FIG.
[Deceleration of switchback speed by edge binding or saddle stitching]
First, as shown in FIG. 11, when the “end face binding mode” and the “saddle stitching mode” are set from the control panel 18 of the image forming unit 2, this is confirmed (Step 10). If this is end-face stitching, a sheet with a relatively short length is frequently used, so the switchback conveyance speed is kept at 1100 mm / s (Step 20). As a result, for example, from one to three sheets, the switchback transport is performed once, and the branch path 70 is made to stand by (branch path standby), and switchback transport is performed to the first processing tray 54 side together with the subsequent sheet. When this standby conveyance is completed, the process ends and the process proceeds to the next step.

  Next, when saddle stitching is confirmed (Step 10), it is assumed that a relatively long sheet is frequently used, and the switchback conveyance speed by the conveyance roller 44 is 1100 mm / s to 600 mm / s as described in FIG. The speed is reduced to s and switchback transport is performed (Step 40). The presence / absence of a subsequent sheet that is carried into the stacker 84 to be bundled is confirmed (Step 50). If there is a subsequent sheet that should not be completed but made into a bundle, the passing conveyance shown in FIG. 10 (b) is executed. If there is no subsequent sheet to be bundled, it is determined that the second tray conveyance process is completed, and the process proceeds to the next process such as saddle stitching.

[Variation: Speed change by checking sheet size in end face binding and saddle stitching]
Next, a modification of the embodiment described so far will be described with reference to the flowchart of FIG.
So far in the embodiment of FIG. 11A, the binding mode is uniform depending on whether the binding is end face binding for binding the end face of the sheet bundle on the first processing tray 54 or saddle stitching for binding the sheet bundle stacked in the stacker 84. It has been selected whether the switchback conveyance speed is kept at 1100 mm / s or is reduced from 1100 mm / s to 600 mm / s. Even in this case, the rough processing can be covered, but there is a long sheet between the conveyance distances even in the case of end-face stitching, whereas a relatively short sheet occurs even in the case of saddle stitching.
By adopting the flow of FIG. 12, a relatively long sheet at the time of end binding or a relatively short sheet at the time of saddle stitching is stably fed.

[Speed change by sheet size at end face binding]
That is, when “end face stitching mode” and “saddle stitching mode” are set from the control panel 18 of the image forming unit 2, this is confirmed (Step 100). If this is end face binding, the process proceeds to the left in the figure, and it is checked whether the length of the sheet on which end face binding is performed is longer than a predetermined length (Step 110). In this modification, the sheet size is set to be short in the case of B5, A4 horizontal and letter, and the length of A3, B4, legal and A4 length is set to be longer than this. If it is short, the switchback conveyance speed is kept at 1100 mm / s (Step 120). As a result, for example, one to three sheets are temporarily switched back and transferred to the branch path 70 (standby for the branch path), and then switched back to the first processing tray 54 side again. When this standby conveyance is completed, the process ends and the process proceeds to the next step.
Note that the recognition of the sheet size in this modification is set by obtaining size information from the image formation control unit 200. Alternatively, a size detection sensor may be disposed near the carry-in entrance 30 of the sheet processing apparatus B for detection.

  On the other hand, when the length of the sheet is long as described above, the switchback transport speed is reduced from 1100 mm / s to 600 mm / s by the transport roller 44 to perform switchback transport (Step 140). In this case, when this standby conveyance is performed with the succeeding sheet, it is confirmed that the preceding sheet has been nipped by the branching roller 72, and the conveyance with the next sheet is performed (Step 160). When this standby conveyance is completed, the process proceeds to the next step.

[Speed change by sheet size at saddle stitching]
When the "end face binding mode" and the "saddle stitching mode" are set and saddle stitching is performed, the process proceeds to the right in the figure, and it is checked whether the length of the sheet on which the saddle stitching is performed is longer than a predetermined length (Step 170). In this modification, when the sheet size is A4 vertical, it is set as short, and for example, A3, B4, and legal are set as long. Here, the A4 length that is long in the end face binding is set to be short in the saddle stitching. This is because the A4 size that can be saddle-stitched is classified into a shorter sheet in the sheet length to be saddle-stitched, and relatively high-speed processing is more likely to be required, and the branch roller 72 stops due to forward and reverse rotation Since it rotates without any problem, the consistency does not deteriorate so much.

In this modification in which the sheet length of the saddle stitching sheet is short, in the case of A4 length, the switchback conveyance speed is kept at 1100 mm / s (Step 180). As a result, when it is determined that the saddle-stitched sheet has been completely carried into the stacker 84 (Step 190), the process proceeds to the next step, assuming that the second tray conveyance is completed.
If the sheet length is long as described above, the switchback transport speed is reduced from 1100 mm / s to 600 mm / s by the transport roller 44 to perform switchback transport (Step 200). In this case, it is confirmed that the second tray conveyance is to be performed with the subsequent sheet (Step 210), and after the preceding sheet is nipped by the branch roller 72, passing conveyance is performed with the next sheet (Step 220).
If there is no subsequent sheet to be bundled, it is determined that the second tray conveyance process is completed, and the process proceeds to the next process such as saddle stitching.

  As described above, in the above modification, the sheet length does not change the speed of the switchback conveyance by the conveyance roller 44 depending on whether it is end face stitching or saddle stitching, and the sheet length in any of the end face stitching or saddle stitching The above switchback speed is changed. Furthermore, for example, the most suitable switchback speed is set even when the length of the A4 length for the end face binding and the A4 length for the saddle stitching is the same, thereby achieving both stable conveyance and high speed.

[Description of control configuration]
The system control configuration of the image forming apparatus described above will be described with reference to the block diagram of FIG. The system of the image forming apparatus shown in FIG. 1 includes an image forming control unit 200 of the image forming apparatus A and a sheet processing control unit 204 (control CPU) of the sheet processing apparatus B. The image formation control unit 200 includes a paper feed control unit 202 and an input unit 203. The setting of the "print mode" and the "sheet processing mode" from the control panel 18 provided in the input unit 203 has already been described.

  The sheet processing control unit 204 is a control CPU that operates the sheet processing apparatus B in accordance with the above-described designated sheet processing mode. The sheet processing control unit 204 includes a ROM 206 storing an operation program and a RAM 208 storing control data. Further, the sheet processing control unit 204 includes a carry-in sensor 30S that detects a sheet in the carry-in path 32, a sheet sensor 42S that detects a sheet in the transport path 42, a branch sensor 70S that detects a sheet in the branch path 70, or Signals from various sensor input units such as a paper surface sensor 24S for detecting a paper surface on the paper discharge tray 24 are input.

    The sheet processing control unit 204 is configured to control a carry-in roller motor 34M for the sheet carry-in path 32, a conveyance roller motor 44M for the conveyance path 42 and the branch path, and an exit roller motor 48M for the exit of the first processing tray 54. It has. Further, the sheet processing control unit 204 controls a punch drive control unit 211 that controls a punch motor 31M that performs punching processing on a sheet by the punch unit 31, an alignment plate 58 that performs sheet stacking operation by the processing tray 29, and the like. A processing tray (first processing tray 54) control unit 212 is provided. In addition, an end face binding control unit 213 that controls an end face binding motor 62M of the end face binding unit 62 that performs end face binding to the sheet bundle on the first processing tray 54; A first tray (first paper discharge tray 24) elevating control unit 214 that controls the elevating motor 24M that elevates according to the sheet switchback is also provided.

Further, the sheet processing control unit 204 controls the saddle moving alignment plate 81 of the sheets to be stacked on the second processing tray stacker 84 for the saddle stitching process, and a stacker that controls the stopper moving motor 85 M of the stopper 85 that regulates the sheet front end. The control unit 216 includes a saddle stitching control unit 217 that controls a saddle stitching motor 82M that binds the middle of the sheet bundle in the conveyance direction.
Furthermore, the sheet processing control unit 204 also includes a folding / discharge control unit 218 that controls a folding roller / folding blade / discharge motor 92M that folds the saddle-stitched sheet bundle in half and discharges it to the second sheet discharge tray 26. Yes.
The connection between each control unit, each sensor for detecting the length of the sheet being conveyed, and each drive motor, etc. is as described in the aspect of each operation.

[Description of sheet processing mode]
The sheet processing control unit 204 of the present embodiment configured as described above causes the sheet processing apparatus B to execute, for example, “print-out mode”, “end face binding mode”, “saddle stitching mode”, and the like. Hereinafter, this processing mode will be described.
(1) "Printout mode"
An image-formed sheet is received from the main body discharge port 3 of the image forming apparatus A, and the sheet is accommodated in the first discharge tray 24 by the conveyance roller 44 and the exit roller 48.
(2) "end face binding mode"
The sheet on which an image has been formed from the main body discharge port 3 is received on the first processing tray 54, and the sheets are partially aligned in a bundle and bounded by the end face binding unit 62, and then stored in the first sheet discharge tray 24. In the end face binding process, “standby conveyance” may be performed in which the preceding sheet is switchback conveyed to temporarily stand by the branch path 70 so as not to stop the discharge of the subsequent sheet from the main body discharge port 3. is there.
(3) "Saddle stitching mode"
The sheet on which an image is formed is received from the main body discharge port 3 of the image forming apparatus A into the stacker 84, and the sheets are collated into a bundle, and the saddle stitching unit 82 staples approximately the center of the sheet in the receiving conveyance direction and folds it into a booklet. The sheet is accommodated in the second sheet discharge tray 26.
In the saddle stitching process, the sheet from the main body discharge port 3 is once discharged onto the first paper discharge tray 24, and then the switch path is transported to the branch path 70 and transported to the stacker 84 “second tray transport” It is carried out.

As described above, according to the embodiment for carrying out the present invention, the following effects can be obtained.
1. A conveyance path 42 for receiving the sheet and conveying the sheet to the first tray (first processing tray 54), and a branch path 70 for branching the conveyance path 42 to convey the sheet to the second tray (stacker 84) The sheet can be transported in either direction of the first tray (the first processing tray 54) or the branch path 70, which is located on the transport path 42 downstream of the branch position 36 between the above-mentioned transport path 42 and the branch path 70. First conveying roller (conveying roller 44), and the second conveying roller (branching roller 72) located in the branch path 70 and capable of conveying the sheet in either direction of the second tray (stacker 84) or the conveying path 42 And a control unit (sheet processing control unit 204) for controlling the first conveying roller (conveying roller 44) and the second conveying roller (branching roller 72), and this control unit (sheet processing control unit) 204), after the sheet conveyed in the conveyance path 42 passes through the branch position 36, the sheet is switchback conveyed to be temporarily kept on the branch path 70 and combined with the subsequent sheet to the first tray (first processing tray 54) The standby conveyance for conveying and the second tray for conveying the sheet conveyed in the conveyance path 42 to the second tray (stacker 84) via the branch path 70 while performing switchback conveyance after passing the branch position 36 This sheet processing apparatus is configured to make the switchback conveyance speed at the time of second tray conveyance different from the switchback conveyance speed at the time of standby conveyance.
According to this, since the speed of the switchback conveyance of the second tray conveyance roller 44 and the speed of the switchback conveyance of the standby conveyance are made different, the switchback conveyance of the sheet can be performed at a speed suitable for the conveyance. It is possible to suppress sheet fluttering and bending expansion during conveyance.

2. The sheet processing apparatus according to 1 above, wherein the switchback conveying speed at the time of conveying the second tray is made slower than the switchback conveying speed at the time of standby conveyance.
According to this, since the switchback conveyance of the second tray conveyance for conveying the relatively long sheet is made slower than the standby conveyance for which the high speed processing is required using the relatively short sheet, the fluctuation or bending of the sheet is caused. Can be suppressed.

3. A paper discharge tray (first paper discharge tray 24) for stacking sheets is arranged on the downstream side of the first tray (first processing tray 54) arranged at the downstream end of the conveyance path, and An end-face binding unit 62 for binding the end face of the sheet bundle is disposed on the tray (first processing tray 54), and a saddle-stitching unit 82 is disposed on the second tray (stacker 84) for binding substantially at the center in the sheet conveyance direction. Sheet processing apparatus.
According to this, end face binding that requires relatively high-speed processing and saddle stitching that binds a relatively long sheet can be appropriately performed.

4. The control unit (sheet processing control unit 204) recognizes the length of the sheet transported through the transport path 42, and when the transported sheet is shorter than the predetermined length, the second tray transport switchback 2. The sheet processing apparatus according to 1, wherein the conveyance speed is substantially the same as a switchback conveyance speed for standby conveyance.
According to this, since the switchback conveyance of the second conveyance is not decelerated when the sheet length is short, the request for high-speed processing can be answered.

5. The first conveyance roller (the conveyance upper roller 44a of the conveyance roller 44) is configured to be movable to a press-contacting position for nipping the sheet to be conveyed and a separation position for releasing the sheet nipping. After the sheet is nipped by the second conveyance roller (branching roller 72) during the switchback conveyance of the second tray conveyance, the control unit 204) moves the first conveyance roller (conveying upper roller 44a) to the separated position 4. The sheet processing apparatus according to 3 above, wherein the next sheet can be received.
According to this, in the case of the second tray conveyance in which the switchback conveyance is decelerated, the conveyance upper roller 44a is moved to the release position to enable the passing conveyance roller 44 of the preceding sheet and the next sheet. Stable conveyance is possible and processing can be performed without significantly reducing productivity.

6. A first tray provided with the apparatus frame 20, a conveyance path 42 for receiving the sheet and conveying the sheet, and an end-face binding unit 62 located on the downstream side of the conveyance path 42 for binding the end face of the sheet (first A processing tray 54), and a paper discharge tray (first paper discharge tray 24) located on the outer side of the apparatus frame 20 on the downstream side of the first tray on which the sheets discharged from the first tray (first processing tray 54) are stacked; The branch path 70 which branches at the branch position 36 on the upstream side of the first tray (first processing tray 54) of the transport path 42 and the downstream side of the branch path 70, while binding the middle in the sheet transport direction The second tray (stacker 84) on which the binding unit 82 is disposed, and the transport path 42 located downstream of the branch position 36, the sheet is directed to the first tray (first processing tray 54) and this direction The first conveying roller (conveying roller 44) that can convey in any direction of the branch path 70 opposite to the direction, and the sheet located on the branch path 70 and opposite to the second tray (stacker 84) direction A second conveying roller (branching roller 72) capable of conveying in any direction of the conveying path 42, and a controller for controlling the first conveying roller (conveying roller 44) and the second conveying roller (branching roller 72). (Sheet processing control unit 204), and this control unit (sheet processing control unit 204) switches back the sheet after the sheet conveyed through the conveyance path 42 passes through the branch position 36, and the branch path 70. Temporarily transports to the first tray (the first processing tray 54) along with the subsequent sheet, and the sheet transported on the transport path 42 after the sheet passes the branch position 36 and the switch bar And the second tray (stacker 84) to be transported to the second tray (stacker 84) via the branch path 70, and the switchback transport speed at the time of this second tray (stacker 84) transport is switched to standby transfer. It is a sheet processing apparatus which makes it slower than the transport speed.
According to this, since the switchback conveyance speed of the second tray conveyance using the relatively long sheet is made slower than the switchback conveyance speed of the standby conveyance using the relatively short sheet, the sheet of the second tray conveyance is reduced. You can suppress flutter and bending.

7. The first conveyance roller (the conveyance upper roller 44a of the conveyance roller 44) is configured to be movable between a press-contacting position for nipping the sheet to be conveyed and a separation position for releasing the sheet nipping. After the sheet is nipped by the second conveyance roller (branch roller 72) during switchback conveyance of the second tray conveyance, the control unit 204) moves the first conveyance roller (conveying upper roller 44a) to the separation position. 7. The sheet processing apparatus according to 6 above, wherein the next sheet can be received.
According to this, in the case of the second tray conveyance in which the switchback conveyance is decelerated, the conveyance upper roller 44a is moved to the release position to enable the passing conveyance roller 44 of the preceding sheet and the next sheet. Stable conveyance is possible and processing can be performed without significantly reducing productivity.

8. An image forming unit for forming an image on a sheet sequentially
The sheet processing apparatus is a sheet processing apparatus that performs predetermined processing on sheets from the image forming unit, and the sheet processing apparatus is an image forming apparatus having the configuration according to any one of the above 1 to 7.
According to this, an image forming apparatus having the effects 1 to 7 can be provided.

  In the description of the effects in the above-described embodiment, for each part of the present embodiment, the corresponding members of the respective constituent elements in the claims are shown in parentheses or reference symbols are attached to indicate the relationship between the two. Was clarified.

  Further, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the present invention, and all technical matters included in the technical idea described in the claims are described in the present invention. The subject of the invention. The embodiments described so far show preferred examples, but those skilled in the art will realize various alternatives, modifications, variations, and improvements from the contents disclosed in this specification. These are included in the technical scope described in the appended claims.

A image forming apparatus B sheet processing apparatus 20 apparatus frame 24 first discharge tray 26 second discharge tray 30 carry-in port 32 carry-in path 36 branch position 37 switching gate 42 transport path 44 transport roller 48 exit roller 54 first processing tray ( (First tray)
57 Reference surface 58 Alignment plate 60 Edge binding portion 62 Edge binding unit 70 Branch path 72 Branch roller 80 Saddle binding portion 81 Saddle binding alignment plate 82 Saddle stitching unit 84 Stacker (second processing tray / second tray)
204 sheet processing control unit 210 sheet conveyance control unit

Claims (8)

A transport path for receiving the sheet and transporting the sheet to the first tray;
A branch path that branches from the transport path and transports the sheet to the second tray;
A first transport roller located on the transport path downstream of the branch position of the transport path and the branch path and capable of transporting a sheet in either direction of the first tray or the branch path;
A second transport roller located in the branch path and capable of transporting the sheet in either direction of the second tray or the transport path;
A control unit for controlling the first transport roller and the second transport roller ;
Equipped with
The control section performs switchback transport of the sheet transported on the transport path after passing the branch position, and temporarily transports the sheet to the branch path, and transports the sheet to the first tray together with the subsequent sheet. The sheet conveyed in the conveyance path performs switchback conveyance after passing the branch position, and performs second tray conveyance for conveying to the second tray via the branch path, and the switch at the time of conveyance of the second tray A sheet processing apparatus, wherein the back conveyance speed is different from the switchback conveyance speed during standby conveyance. The sheet processing apparatus according to claim 1, wherein a switchback conveyance speed during the second tray conveyance is made slower than a switchback conveyance speed during the standby conveyance. A sheet discharge tray for stacking sheets is disposed on the downstream side of the first tray arranged at the downstream end of the transport path, and an end face binding unit for binding an end face of a sheet bundle is disposed on the first tray; The sheet processing apparatus according to claim 2, wherein a saddle stitching unit that binds substantially the center in the sheet conveyance direction is disposed in each of the two trays.   The control unit recognizes the length of the sheet conveyed on the conveyance path, and when the conveyed sheet is shorter than a predetermined length, the switchback conveyance speed of the second tray conveyance is set to the standby conveyance switch. The sheet processing apparatus according to claim 1, wherein the speed is substantially the same as the back transport speed. The first conveying roller is further configured to be movable between a pressure contact position for nipping a sheet to be conveyed and a separation position for releasing the sheet nip, and the control unit is configured to transfer the sheet during the switchback conveyance of the second tray conveyance. The sheet processing apparatus according to claim 3, wherein after being nipped by the second conveyance roller, the first conveyance roller is moved to a separation position so that a next sheet can be received. A device frame;
A conveyance path for receiving the sheet and conveying the sheet;
A first tray on the downstream side of the transport path and provided with an end surface binding unit that binds the end surface of the sheet;
A sheet discharge tray positioned outside the apparatus frame on the downstream side of the first tray on which the sheets discharged from the first tray are stacked;
A branch path that branches at a branch position upstream of the first tray of the transport path;
A second tray disposed on the downstream side of the branch path and provided with a saddle stitching unit for stitching the middle in the sheet conveyance direction;
A first transport roller located on the transport path downstream of the branch position and capable of transporting the sheet in either the first tray direction or the branch path direction opposite to the first tray direction;
A second transport roller located on the branch path and capable of transporting the sheet in any direction of the second tray direction and the transport path direction opposite to the second tray direction;
A control unit for controlling the first transport roller and the second transport roller ;
Equipped with
The control section performs switchback transport of the sheet transported on the transport path after the sheet passes the branch position, and temporarily transports the sheet to the branch path, and transports the sheet to the first tray and transports the sheet to the first tray. A second tray is transported to the second tray through which the sheet conveyed on the path passes the branch position and switchbacked to be conveyed to the second tray via the branch path, and the switchback conveying speed at the time of the second tray conveyance is A sheet processing apparatus, wherein the sheet processing apparatus is slower than a switchback conveyance speed of standby conveyance. The first transport roller is configured to be movable to a press-contact position for nipping a sheet to be transported and a separation position for releasing the nip of the sheet, and the control unit controls the sheet during switchback transport of the second tray transport. The sheet processing apparatus according to claim 6, wherein after being nipped by the second conveyance roller, the first conveyance roller is moved to a separation position so that a next sheet can be received. An image forming unit for sequentially forming an image on a sheet;
An image processing apparatus comprising: a sheet processing apparatus that performs a predetermined process on a sheet from the image forming unit, and the sheet processing apparatus includes the configuration according to any one of claims 1 to 7. Forming equipment.

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