JPH0873108A - Sheet after-treatment device - Google Patents

Abstract

PURPOSE: To prevent a sheet bundle from occurring folds or creases in the case of performing afterprocess such as stapling so as to smoothly discharge it by detecting the load current value of the drive source of a delivery means feeding a sheet bundle kept on file to a discharge belt, and controlling a drive means to be variable in speed following to the detected result. CONSTITUTION: When sheets P after staple processing are pushed up by the delivery lever 442 of a sheet delivery part 440 so as to feed them to an intermediate stacker 426, the load current value of a first motor driving the delivery lever 442 is changed according to the number of sheets of the sheet bundle. After stopping drive of the first motor, a discharge belt 425 is driven by a second motor so as to being the rotational movement, but when the load current value of the first motor at this time is over a specific value, it is judged to be the sheet bundle of many sheets over the specific number of sheets, and the rotating speed of the second motor driving the discharge belt 425 is controlled to be decelerated. Meanwhile, when it is judged to be the sheet bundle of the small number of sheets under the specific number, the driving rotating speed is controlled to be high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet post-processing apparatus for automatically binding and discharging recording sheets (sheets) on which images are recorded by an image forming apparatus, and particularly to a high-speed image forming apparatus. The present invention relates to a sheet post-processing device that can handle the above.

[0002]

2. Description of the Related Art A sheet post-processing device called a finisher is used as a device for collating a plurality of image-recorded sheets discharged from an image forming apparatus for each number of copies and binding them by a stapler.

The finisher has a function connected to the image forming apparatus main body and is driven in response to the sequence operation of the copying process.

Therefore, for an image forming apparatus capable of high-speed processing of the copy process, a finisher capable of high-speed processing capable of following the speed and performing its function is required.

Regarding the finisher capable of such high speed processing, Japanese Patent Laid-Open Nos. 60-142359 and 60-158463 have already been disclosed.
No. 62-239169, and JP-A Nos. 62-288002 and 63-267.
The proposals disclosed in Japanese Patent Publication No. 667, Japanese Patent Laid-Open No. 2-276691, and Japanese Patent Publication No. 5-41991 are disclosed.

In the sheet post-processing apparatus, the image-recorded sheets carried out from the main body of the image forming apparatus are sequentially stacked while being aligned in the intermediate stacker to store a set of sheet bundles, and then the stapler or the like. The sheet post-processing is performed, and the bound sheet bundle is placed on a discharge belt provided at the bottom of the intermediate stacker and conveyed, and is sandwiched by a pair of upper and lower discharge rollers and discharged to a discharge tray. .

[0007]

A sheet bundle placed on the discharge belt and conveyed is sandwiched and discharged by a pair of upper and lower sheet discharge rollers provided on the downstream side in the conveying direction. When the number of sheet bundles is small, the sheets are normally sandwiched by the discharge rollers and discharged, but when the number of sheet bundles is large, the leading edge of the sheet bundle is immediately before the nip portion of the upper sheet discharge rollers. It is difficult for the sheet to enter the gap, and the sheet comes into contact with the peripheral surface of the sheet discharge roller, and the tip of the sheet is bent, and wrinkles and tears occur.

The object of the present invention is to solve the above-mentioned problems and improve the results. As a result, a large number of sheets can be aligned and stapled sufficiently for an image forming apparatus of high speed printing of about 90 to 100 sheets per minute. Another object of the present invention is to provide a sheet post-processing device (finisher) that can perform post-processing to prevent the sheet bundle from being folded or wrinkled and smoothly discharge the sheet.

[0009]

The above object is to provide a stacker for introducing and stacking a plurality of sheets of various sizes conveyed from an image forming apparatus, and temporarily storing the stacker, and a leading end portion of the plurality of sheets in the conveying direction. A stopper member to be aligned, an aligning unit that aligns the plurality of sheets in a direction orthogonal to the transport direction, a stapling unit that binds the bundle of sheets stacked and aligned on the stacker, and a transport of the bound sheet bundle. In a sheet post-processing apparatus including a rotatable discharge belt for discharging and a discharge tray for storing a sheet bundle discharged by the discharge belt, sheets stacked, aligned, aligned and bound on the stacker A delivery unit that sends the bundle to the discharge belt, a drive unit that can change the discharge linear velocity of the discharge belt in a plurality of stages, and the sheet bundle. Detecting a load current value of a drive source that movably drives the transfer means when sending out to the exit belt side, and detecting the number of sheet bundles sent to the discharge belt from the load current value detected by the detecting means. And a control unit that controls the drive unit at a variable speed according to the number of the sheet bundle. When the load current value is greater than a preset number of sheets, the control unit and the drive unit cause the discharge belt to move. The sheet post-processing apparatus is characterized in that the linear velocity of the sheet is decelerated.

Further, the above object is to detect the thickness of the sheet bundle by detecting a movable paper pressing means for pressing the sheet bundle before the binding processing by the stapling means and the moving range of the paper pressing means. Detecting means, a driving means capable of shifting the discharge linear velocity of the discharge belt in a plurality of stages, and the driving means can be operated in accordance with the thickness of the sheet bundle detected by the detecting means according to the number of the sheet bundle. When the number of sheets of the sheet bundle is larger than a predetermined number, the control means and the drive means,
This is achieved by a sheet post-processing apparatus characterized by controlling the linear velocity of the discharge belt to be decelerated.

Further, the above-mentioned objects are: a passage sensor for detecting passage of the sheets carried out from the image forming apparatus and introduced into the stacker; and a first sheet bundle of one sheet detected by the passage sensor. Measuring means for measuring the conveyance time from passage to passage of the final sheet, driving means for changing the discharge linear velocity of the discharge belt in a plurality of stages, and conveyance of a bundle of sheets detected by the measuring means. And a driving means for controlling the driving speed of the discharge belt in a variable speed according to time, and when the conveying time of the sheet bundle is longer than a predetermined number, the controlling means and the driving means decelerate the linear velocity of the discharge belt. And a sheet post-processing device.

[0012]

Embodiments of the sheet post-processing apparatus of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of a copying machine equipped with a sheet post-processing device. 100 is a copying machine main body, 200 is a paper feeding unit (PFU device), and 300 is a circulation type automatic document feeder (RDH device). ), 400 is a sheet post-processing device (finisher, hereinafter also referred to as FNS device).

The copying machine main body 100 includes a scanning exposure unit 110, an image forming unit 120, a paper feeding unit 130, a conveying unit 140, a fixing unit 150, a paper discharge switching unit 160, a plurality of paper feeding cassettes 170, and a double-sided recording sheet reprocessing unit. It is composed of a sheet feeding device (ADU device) 180.

In the figure, the alternate long and short dash line indicates the conveyance path of the sheet P. The sheet P stored in the paper feed cassette 170 or the paper feed unit (PFU device) 200 at the bottom of the copying machine main body 100 is
After the image is formed by the image forming unit 120, the conveying unit 140
Then, the main route stored in the FNS device 400 via the fixing unit 150 and the paper discharge switching unit 160, and the sheet P branched from the paper discharge switching unit 160 are temporarily stocked in the ADU device 180 and then re-fed. And a circulation route to the paper feeding unit 130 of the copying machine main body 100.

The document D stacked on the document placing table of the RDH device 300 is started to be fed by the operation of the copy button on the operation panel of the copying machine main body 100, and is fed by the conveying belt 302 via the feeding unit 301. It is transported onto the platen glass 111 and installed at the exposure position.

The document D is read by receiving the exposure scan of the document image by the operation of the scanning exposure unit 110, and after the reading is completed, the conveyor belt 302 is rotated again and fed, and is fed through the reverse sheet discharge path 303. It is accommodated in the lowermost layer of the original stack on the original placing table.

Although the circulation of the original document D has been described above, the RDH device 300 has the automatic document feeder (AD).
F is also provided with the function of F). In that case, the document D whose image has been read goes straight and is ejected through the ejection rollers to the ejection tray 30.
4 Discharge and stack on top.

A copy image of the original D obtained by the exposure scanning passes through the image processing process of the copying machine main body 100, and the sheet P fed from the paper feeding cassette 170 or the PFU device 200.
Recorded in.

The sheet P on which the image is recorded is the ADU described above.
The sheet is once fed to the apparatus 180, turned upside down, and discharged from the sheet discharge switching unit 160 in a posture with the image surface facing downward.
The paper is fed to the S device 400.

FIG. 2 is a sectional view showing the structure of the FNS device 400. The FNS device 400 is installed by adjusting the position and height so that the receiving roller 401 of the sheet P is aligned with the sheet discharge port of the copying machine main body 100, and is controlled so as to be driven according to the operation of the copying machine main body 100. Connected to the system.

The conveying path of the sheet P connected to the rear side of the receiving roller 401 is an upper offset conveying path 410 (first
A conveyance path), a second conveyance path 420 in the middle stage, and a third conveyance path 430 in the lower stage, and the sheet P is fed to one of the conveyance paths by selecting the angle occupied by the switching gates G1 and G2. It will be sent. U1 is the first
A first unit forming a conveyance path, U2 is a second unit forming a second conveyance path, and U3 is a third unit forming a third conveyance path.
It is a unit.

The second transport path 420 and the third transport path 430 described above.
Is equipped with guide belts 422 and 432 at each end on the downstream side of the conveyance, and feeds the trailing end of the sheet P to the stapler section. Further, at positions facing the guide belts 422 and 432, discharge belts (timing belts) 425 and 435 provided with discharge claws 424 and 434, respectively, and a first position at a position sandwiching these discharge belts 425 and 435. The stacker 426 and the second stacker 436 are installed with a predetermined inclination angle. Of the three rollers wound around the guide belts 422 and 432, the lowermost roller is the impellers 423 and 433, so that the sheet P
When the switch backs, the sliding contact action of the impellers 423 and 433 may surely abut the stoppers 441 and 451 described later.

Further, a first stapler ST1 and a second stapler ST2 are arranged at positions facing the respective lower end portions of the first stacker 426 and the second stacker 436.

On the downstream side of the sheet conveying of the first stacker 426, near the sheet discharging section of the FNS device 400, there is provided a first discharging means 460 consisting of a pair of upper and lower discharging rollers. Similarly, a second sheet discharging unit 470 is provided on the downstream side of the second stacker 436.

Further, a discharge tray elevating means 480 is arranged on the right side of the FNS device 400. The paper output tray elevating means 480 is provided with a pair of support members 482 before and after vertically moving by engaging a plurality of guide rollers 481.
The first discharge tray T1 and the second discharge tray T2 are respectively sandwiched by the support member 482 and vertically moved separately.

The staplers ST1 and ST2, the stackers 426 and 436, the discharge belts 425 and 435, etc. are supported by a pair of front and rear unit substrates II and III, respectively, and a pair of guide rails R1 and R2 are provided on the unit substrates II and III, respectively. FNS device 400
Since it has a structure that can be attached and detached inside, if the front side in the figure of the device can be opened by a door, the stapler etc. can be removed in the unit state, and maintenance such as jam handling etc. can be done easily. You can do it.

The pair of supporting members 482 is a lifting wire 484 stretched between individual dedicated motors M1 and M2 and a pulley 483.
The first paper discharge tray T1 and the second paper discharge tray T2 are individually moved in parallel in the vertical direction by rotation of the motors M1 and M2.

The control circuit built in the copying machine main body 100 and the FNS device 400 is composed of a basic circuit as shown in the block diagram of FIG. Prior to the start of the copy operation, the paper discharge mode (staple mode or non-sort mode) is selected, and the number of originals and the number of copies are set.

When the non-sort mode that does not require binding is set, the switching gates G1 and G2 are held in the initial state, the sheet P moves straight, and the receiving roller 40
1, the intermediate roller 402, the conveyance belt 403, and the discharge roller 404, and a first conveyance path (offset conveyance path) 410 is ejected to the outside of the machine, and the sheet is placed and stored on the upper first ejection tray T1.

When the offset mode is selected as the sheet discharge mode, the switching gates G1 and G2 are held in the initial state, the sheet P is fed upward, and the sheet P is fed to the first conveying path 410. Conveyor belt 403 and discharge roller 40
The sheet is discharged onto the first sheet discharge tray T1 via the sheet 4. A pair of the discharge rollers 40 including a driving roller and a driven roller.
Numeral 4 is provided with an offset driving unit capable of reciprocating in the direction perpendicular to the drawing, and shift-driving after detecting the trailing edge passage of the discharged sheet P to make the sheet P zigzag in the left and right direction with respect to the discharged sheets. It is configured so that they can be stacked and sorted easily.

When the binding mode is selected as the paper discharge mode, the switching gate G2 rotates, and the sheet P fed by the receiving roller 401 advances straight and is fed to the second transport path 420. , The guide belt 4 in the second unit U2
The sheet P is temporarily pushed up and placed on the first stacker 426 via the guide belt 422.
And the weight of the sheet P slides down on the first stacker 426 and is guided to the binding portion of the first stapler ST1 (stopper 441 of the sheet delivery means 440).

First set of sheets P corresponding to the number of documents D
After the last sheet of the sheet is detected by the sensor S1, the switching gate G1 is rotated, and the sheet P of the second copy is fed downward and fed to the third conveyance path 430, and is guided in the same manner as described above. Belt 4
By the action of 32, the push-up mounting is started on the second stacker 436. The transfer unit 450 of the third unit U3
Has the same structure as the sheet passing portion 440 of the second unit U2.

On the other hand, during the feeding of the second set of sheets P,
The sheets P of the first set, which have been stacked, are bound by the operation of the first stapler ST1, and then the first stacker 426 is pushed by the pushing back operation of the delivery lever 442.
It is pushed up against the gravity to a predetermined position and held.

FIG. 4 is a sectional view of the sheet discharging portion. Figure 5
5A is a plan view of the sheet discharging portion, FIG. 5B is a sectional view taken along line AA, and FIG. 5C is a sectional view taken along line BB.

The delivery lever 442 of the sheet delivery section 440 reciprocates only when the bound sheet bundle is discharged.

The first discharge belt 425 is driven by the motor M3 to rotate the gears Z1 and Z2 and the timing pulley TP1.
Through the TP2 and the timing belt TB1, the first copy of the sheet P that has been bound while starting to rotate in the direction of the arrow and pushing up the rear end surface of the sheet P by the discharge claws 424 and stopping for one round is stopped. The sheet is discharged onto the first sheet discharge tray T1.

During this time, the stacking of the sheets P of the second copy is completed and the switching gate G2 is restored again.
The second set of sheets P is bound by the operation of the second stapler ST2, and the second set of sheets P bound by the protrusion of the stopper 451 and the rotation of the second discharge belt 435 are the same as those described above. 2 The sheet is discharged onto the sheet discharge tray T2.

As described above, according to the FNS device 400 of the present invention, a plurality of sheets P on which images are recorded can be collated and bound in parallel at two places without a particular time difference. Therefore, the post-processing of the sheet P is quickly performed.

The motor M3 operates according to the discharge amount of the sheet P, and the first and second discharge trays T1 and T2 are lowered by the number corresponding to the number of processed sheets so that the sheet P can be discharged. .

The above-mentioned first and second staplers S
Both T1 and ST2 are the first and second stackers 426.
And 436 are installed on the front side of the drawing,
When the sheet P is placed vertically long and ejected, the upper left one place can be bound with staples, but if a stapler is additionally installed on the back side of the drawing, it is also possible to bind with two staples. When the paper is ejected horizontally, it is possible to staple the upper left one place with staples.

The matching process of the present invention will be described below.

The first transfer path 420 provided in the upper second transfer path 420
Since the aligning means 427 of the stacker (intermediate stacker) 426 and the aligning means of the second stacker 436 provided on the lower third transport path have the same structure, the upper aligning means 427 will be described below as a representative.

Sheet P discharged onto the first stacker 426
The width direction (direction orthogonal to the transport direction) mounting position is the first
The reference surface (rising surface) 426A of the stacker 426, the drive pulley 4271 and the driven pulley that are rotated by the drive of the motor M4.
It is regulated within the interval between the rising surface 4274A of the movable matching plate 4274 locked by the timing belt 4273 that winds the 4272. The bearing portion 4274B of the movable matching plate 4274 is the second unit U.
The movable aligning plate 4274 is fitted to a guide shaft 4275 installed on the second machine frame, and is supported so as to be capable of reciprocating in a direction orthogonal to the sheet conveying direction. Further, a resin guide 4276 is integrated with the other end of the movable matching plate 4274, and is fitted and movably supported by a guide member 4277 fixed to the unit machine frame.

The bearing portion 4274B side of the movable matching plate 4274 is locked to the timing belt 4273 and is rotated by the driving rotation of the stepping motor M4.
Moves back and forth with 4273. An optical path shielding plate portion 4274C projects near the bearing portion 4274B, and detects a predetermined home position position of the movable matching plate 4274 by turning on / off the detection optical path of the photo interrupter type home position sensor S14.

The number of copies to be copied and the set value (N1) of the number of sheets for each part are sent by communication from the main body of the copying machine.

Intermediate stacker 426 of the sheet post-processing device 400
(436) The number of passing sheets P is sequentially counted by the sensor S42 (S43) provided near the entrance (N2).

The sheet P is conveyed onto the intermediate stacker 426 (436), slides down the inclined surface, contacts the stopper 441 (451), and stops.

At this stop position, the movable aligning plate 4274 of the aligning means 427 moves toward the side edge of the sheet P from a position about 20 mm away from the outer side in the width direction of the sheet P, and the sheet P is moved.
Is pressed against the reference surface 426A, and further about 3 m from the width of the sheet P.
m Return to the original position by flipping to the inner position.

Stacker 426 (436) for each sheet P
The movable aligning plate 4274 reciprocates once every time it is conveyed to perform the paper aligning operation. The sheet P stacked on the intermediate stacker 426 (436) slides toward the stopper 441 (451) due to its own weight and sliding contact with the subsequent sheet P when the subsequent sheet P slides down. .

When the number of sheets P conveyed on the intermediate stacker 426 (436) is counted by the sensor S42 (S43) and it is detected that the set value N1 is met (N2 = N1), the final process is completed. With respect to the sheet bundle in which the sheets P are stacked, the movable aligning plate 4274 is set to 1 by the paper aligning operation.
After reciprocating movement, the sheet bundle is moved again to the side edge of the sheet bundle and is pressed against the sheet bundle side edge (final alignment operation).

In this sheet bundle pressure contact state, a paper pressing lever 443, which will be described later, is raised to press the rear end of the sheet bundle, and the stapling operation is performed.

When the number of sheets N2 is 25 or less, the above-described paper aligning operation for each sheet and the final aligning operation after the final sheet is stopped are performed.

When the number of sheets N2 is 25 or more,
After the paper aligning operation described above is performed and the final sheet P is placed on the sheet bundle on the stacker 426 (436), about 1
After a lapse of seconds, the final alignment operation is performed, and the paper pressing lever 443 is lifted and the stapling operation is performed while the side ends of the sheet bundle are pressed against each other. This is a stacker for many sheets of 25 or more
When stacked on 426 (436), the final paper will stop without contacting the stopper. On the other hand, by leaving a margin of about 1 second after the paper alignment for the final alignment operation, the final sheet P slides down on the preceding sheet P by its own weight and moves toward the stopper 441 (451). Advance and stop. In this way, the final sheet P can surely slide down to the predetermined stop position. This sheet alignment result is particularly large when the sheet is conveyed at high speed. The margin time of about 1 second is not limited to this.
It depends on the sheet conveying speed, the surface friction of the sheet, the weight of the sheet, the inclination angle of the intermediate stacker 426 (436), etc., and the optimum margin time is determined by these setting conditions.

The paper discharge means 460 is connected to a drive source (stepping motor M5) and driven and rotated by a lower roller 461, an upper roller 462, and an arm 46 for swingably supporting the upper roller 462.
3, a support shaft 464 that supports the swingable arm 463, a spring 465 that biases the arm 463 with a spring, and a sheet introduction guide plate 466 that is provided near the peripheral surface of the lower roller 461. There is. The lower roller 461 is rotatably supported at a predetermined position on the frame of the FNS device 400. The upper roller 462 is driven by its own weight and the predetermined urging force of the spring 465 to cause the lower roller 4 to move.
Pressed against 61. 468 is an F guide plate for sheet introduction fixed near the lower roller 461. The lower surface of the arm 463 also serves as an upper guide plate 463A for sheet introduction.

The paper discharge means 4 at the most downstream side of the third conveyance path 430
Reference numeral 70 has substantially the same structure as the paper discharge means 460.

FIG. 6 is a perspective view of the stapler ST1 and the sheet delivery means 440, FIG. 7 is a front view of the sheet delivery means 400, and FIG. 8 is a plan view thereof. The sheet delivery means 440 and the stapler ST1 provided at the end of the upper second transport path 420 have the same structure as the sheet delivery section 450 and the second stapler ST2 provided at the end of the lower third transport path 430. The common structure will be described below.

The sheet transfer section 440 and the first stapler ST1 are integrated with each other, and can slide on a slide rail (not shown) to move in the direction orthogonal to the sheet conveying direction, and between the drive pulley and the driven pulley. It is fixed to a part of a rotatable timing belt stretched around and is connected to a stepping motor M5 as a drive source via a gear train.
Then, the sheet transfer section 440 and the first stapler ST
The driving and the position control of No. 1 are performed by the stepping motor M5.

The sheet transfer section 440 is introduced from the second conveyance path 420, slides on the first discharge belt 425 and the first stacker 426 by the guide belt 422 to rise, and after the discharge, the rear end of the sheet P. Is temporarily held and stopped, and after the binding process (stapling process) at this stop position, it is sent out again and sent out by the discharge claws 424 of the first discharge belt 425.

The sheet transfer unit 440 is a stopper 441 for abutting reference for abutting and aligning the rear end of the sheet P.
And a pair of movable left and right delivery levers 442 for sending the sheet P to the first discharge belt 425 side, and a pair of movable left and right sheet pressing levers 443 for holding the sheet P at the time of stapling.

The delivery lever 442 has a guide surface portion 442A for introducing the sheet P and an abutting surface portion 442B for pushing out the rear end of the sheet P. The pair of left and right delivery levers 442 are two connecting bars 4421, 4422. Are connected and integrated by. The delivery lever 442 is a sheet delivery unit 440.
It is slidable and movable in the guide groove portion 444A formed in the frame body 444 (broken line shown in FIGS. 7 and 8). The delivery lever
The spring 442 biases the spring 442 in one direction. The transfer lever 442 is moved by a first link member 4451 and a second link member driven by a motor M6 as a drive source.
Done through 4452. That is, the driving force of the motor M6 is reduced through the gear train including the worm Z3 and the worm wheel Z4 to rotate the drive shaft 446. A cam 4461 is fixed near the center of the drive shaft 446. A roller-shaped cam follower 4462 is rotatably supported at one end of the first link member 4451. The rotation of the cam 4461 causes the cam follower 4462 to follow the pressure contact, and the first link member 4451 is illustrated in FIG. It can move to the left and right (broken line).
The left end of the first link member 4451 is rotatably connected to the second link member 4452 by a pin 4453. The second link member 4452 is swingably supported about a fulcrum pin 4454, and the other end of the second link member 4452 is connected to the delivery lever 442 by a pin 4455.

7 and 8, the solid line indicates the initial position and the stop position during stapling, and the broken line indicates the state in which the stapled sheet P has been sent to the first discharge belt 425 side. The drive rotation of the motor M6 causes the drive shaft 446 to rotate via the worm Z3 and the worm wheel Z4, and the rotation of the cam 4461 integrated with the drive shaft 446 presses the cam follower 4462 to form the first link member 4451 integral therewith. It is moved to the right and the second link member 4452 is swung in the clockwise direction in the drawing around the fulcrum pin 4454, and the delivery lever 442 is moved.
To the right in the figure. By the movement of the delivery lever 442, the abutting surface portion 442B of the delivery lever 442 pushes out the rear end of the sheet P and sends it to the first discharge belt 425 side.

Next, prior to the stapling operation, the sheet P is
The paper pressing operation by the paper pressing lever 443 for pressing is described.

Two cams 4563 and 4464 having the same shape are fixed near both ends of the drive shaft 446, and are pressed against a cam follower 4431 fixed to the lower portion of the paper pressing lever 443. By the drive rotation of the drive shaft 446, the cam follower 4431, which is in pressure contact with the cams 4465 and 4464, rises together with the paper pressing lever 443 in the urging direction of the spring 4432, and the U-shaped stopper 441.
Press the area near the rear end of the sheet bundle against the inner upper surface of the sheet and press it into contact therewith.
In this sheet pressing state, the first stapler ST
The binding by 1 is performed. The sensor S16 is a photo interrupter type optical sensor that detects the paper pressing by the paper pressing lever 443, and generates a signal by turning on / off the optical path by an optical path blocking unit provided on the cam 4363.

FIG. 9 is a sectional view of the sheet discharging means 460. The sheet bundle P placed on the first discharge belt 425 is obliquely lifted on the first discharge belt 425 and the surface of the first stacker 426 which rotate while the rear end of the sheet is held by the paper discharge claw 424. Then, after the leading end of the sheet bundle P passes through the paper discharge means 460, it is placed on the first paper discharge tray T1.

The paper discharging means 460 is connected to a drive source (motor M3) and driven and rotated by a lower roller 461, an upper roller 462, an arm 463 for swingably supporting the upper roller 462, and a swingable arm. A support shaft 464 for supporting the 463, a spring 465 for urging the arm 463 with a spring, and a guide plate 466 for introducing a sheet provided near the peripheral surface of the lower roller 461. The lower roller 461 is rotatably supported at a predetermined position on the frame of the FNS device 400. The upper roller 462 has its own weight and the spring 465.
Is pressed against the lower roller 461 by a predetermined biasing force. 468 is an F guide plate for sheet introduction fixed near the lower roller 461. The lower surface of the arm 463 also serves as an upper guide plate 463A for sheet introduction.

It should be noted that the paper discharge means 4 at the most downstream side of the third transport path 430
Reference numeral 70 has substantially the same structure as the paper discharge means 460.

FIG. 10 shows a flowchart of the above-mentioned sheet post-processing process.

FIG. 11 shows a sheet post-processing apparatus 400 according to the present invention.
FIG. 6 is a configuration diagram showing the sensor arrangement and the movement of the discharge tray of FIG.

First, a sheet passage sensor S1 is provided near the sheet introduction opening of the FNS device 400, and the passage of the sheet P detects the presence of the sheet in the FNS device 400. A sheet trailing edge passage detection sensor S4 is provided on the upstream side of the ejection roller 404 in the offset conveyance path 410, and the ejection roller 404 is shifted in the direction perpendicular to the paper surface by the trailing edge passage detection during the offset mode conveyance. Discharge roller 404 further downstream
A sheet discharge sensor S5 is provided on the downstream side of, to detect the presence of a sheet.

Paper passage sensors S6 and S42 are provided upstream of the conveyance rollers 421 of the second conveyance path 420 below the offset conveyance path 410 to detect the passage of the sheet P.
The sensor S8 detects that there is no sheet on the upper first stacker 426. S16 is a sensor for detecting the paper pressing position of the upper transfer unit. S24 is a home position sensor for the first discharge belt 425. S9 is a paper discharge sensor.

Similarly, the third paper path 430 is also provided with paper passage sensors S11, S43, paper out detection sensor S12, paper pressing position detection sensor S18, and paper ejection sensor S13.

Next, in the elevating and lowering drive unit of the paper discharge trays T1 and T2, the offset upper stage detection sensor S69 and the offset paper removal detection sensor S70 are arranged near the discharge port of the uppermost offset conveyance path 410, and the interruption A tray upper limit detection sensor S27 and a tray paper ejection detection sensor S for controlling the raising and lowering of the first paper discharge tray T1 near and below the discharge port of the second transport path 420
29, a tray collision detection sensor S63, and a tray lower position detection sensor S28 are provided, and a tray upper limit position detection sensor S65 for controlling the raising and lowering of the second paper ejection tray T2 near the discharge port of the lower third conveyance path 430, A tray paper ejection detection sensor S30 is provided, and a tray lower limit position detection sensor S66 for controlling the lowering of the second paper ejection tray T2 is provided at the lowermost stage.

In FIG. 11, T1A is the first paper discharge tray T.
1 is the initializing position (initial setting position) during stapling, T1B is the lower limit position when stacking up to 1500 sheets, and T1C is the lower limit offset position when placing up to 2000 sheets. , T1D indicates the offset initialization position.

Further, as an ascending / descending position of the lower second discharge tray T2, T2A is the initializing position for stapling operation, and T2B is the second discharge tray 2 when a maximum of 2000 sheets are stacked on the first discharge tray T1. Shows the lower limit position for withdrawal. At the lower limit position T2B of the second discharge tray T2, discharge from the second stacker 436 as well as the first stacker 426 is prohibited.

FIG. 12 is a diagram showing a load current characteristic of the motor M5 when the transfer lever 442 is driven forward at a predetermined speed. FIG. 12A shows a change in current value when 50 A4 size sheets P are stacked and sent out. When driving the motor M5, a current value of about 3 A (ampere) at maximum is required due to the load of a large number of sheets (50 sheets). Figure 12 (B) is A4
A change in current value when only one size sheet P is sent out is shown. At this time, since the torque at the time of starting the motor M5 is small, a maximum current value of 2 A (ampere) is shown.

FIG. 13 is a timing chart of the sheet delivery operation by the sheet delivery section 440 and the first delivery belt 425 of the sheet post-processing apparatus according to the present invention (first embodiment).

When the sheet P after stapling is pushed up by the delivery lever 442 of the sheet delivery unit 440 and sent out to the intermediate stacker 426, the load current value of the motor M5 that drives the delivery lever 442 is the number of sheet bundles. Depends on That is, when the number of sheet bundles is large, the load current value is large. Here, the load current value is detected by the detection means, and the control means compares and detects whether the load current value exceeds a predetermined set value.

After the driving of the sheet delivery / paper pressing motor M5 is stopped, the first discharge belt 425 is driven by the motor M3 to start rotation. At this time, if the load current value of the motor M5 is equal to or more than a set value (for example, 2.5 A), it is determined that the number of sheets exceeds a predetermined number, and the motor M that drives the first discharge belt 425 is determined.
The driving rotational speed of 5 is controlled to be decelerated, and the conveying linear velocity of the first discharge belt 425 is decelerated to a low speed rotation of, for example, 500 mm / s,
The stapled multi-sheet bundle is sent to the paper discharge unit 460.

If the load current value of the motor M5 is equal to or less than a set value (for example, 2.5 A described above), it is determined that the sheet bundle is a small number of sheets equal to or less than a predetermined number, and the first discharge belt 425.
The driving rotational speed of the motor M5 for driving the sheet is set to the high speed side, the conveying linear velocity of the first discharge belt 425 is set to a high speed rotation of, for example, 1000 mm / s, and a small number of stapled sheets are discharged to the sheet discharging means. The sheet is discharged to the outside of the machine by 460 and placed on the sheet discharge tray T1. The drive means of the paper discharge means 460 is connected to the drive source (motor M3) of the first discharge belt 425, and the paper discharge vertical rollers 461 and 462 are connected to the first discharge belt 42.
The sheet bundle is discharged at a linear velocity which is approximately equal to or slightly higher than the conveying linear velocity of 5.

FIG. 14 is a timing chart showing a second embodiment of the discharge belt traveling control of the sheet post-processing apparatus according to the present invention.

When the drive of the motor M5 is started, the drive shaft
446 and the two cams 4363 and 4464 which are integrated with it start rotating, and the cams 4363 and 4464 press the cam follower 4431 to raise the paper pressing lever 443 and the stopper 441.
The rear end of the sheet bundle having the sheets aligned therein is pushed upward and compressed. By installing the sensor S16 at a predetermined position, in the process of raising the paper pressing lever 443,
The predetermined thickness of the sheet bundle can be detected. That is, by installing the sensor S16 so as to be able to detect a sheet bundle having a predetermined thickness, it is possible to detect a larger number of sheets and a smaller number of sheets. When the control unit judges a bundle of a small number of sheets by this detection signal, the first discharge belt 425 is conveyed at a high speed (for example, 1000 mm / s), and when it is judged that a bundle of a large number of sheets is conveyed, the first discharge belt 425 is conveyed at a low speed ( For example, 500 mm / s).

FIG. 15 is a timing chart showing a third embodiment of the discharge belt traveling control of the sheet post-processing apparatus according to the present invention.

Any of the sheet passage sensors S1, S6, S42 passes the first sheet P of the sheet stack loaded on the first tray (intermediate stacker) 426 or the second tray (intermediate stacker) 436, and the final sheet P. When the passage of the sheets P is detected, the control unit controls the transport time t of the total number of sheets.
Measure ₁ with a timer. When the conveyance time t ₁ by this timer is shorter than the predetermined time t ₀ set in advance, the comparison circuit of the control unit judges that the sheet bundle is a small number, the motor M3 is rotated at high speed, and the discharge belt 425 (4
35) is set to a high conveying linear velocity (for example, 100 mm / s), and the stapled sheet bundle is conveyed at high speed and discharged from the sheet discharging means 460 (470) to the sheet discharging tray T1 (T2) outside the apparatus. . Further, the total sheet conveyance time t ₂ by the timer is
Is greater than the predetermined time t ₀ , the control unit determines that the sheet bundle is a large number, rotates the motor M3 at a low speed, and causes the discharge belt 425 (435) to move at a low conveying linear velocity (for example,
Set to 500 mm / s) and eject the stapled sheet bundle at low speed.

In this embodiment, the sheet post-processing device connected to the copying machine is shown, but it is also possible to use it by connecting it to an image forming device such as a printer or a famicular or a light printing machine.

[0086]

EFFECTS OF THE INVENTION According to the present invention, the sheet post-processing can be performed at an optimum conveying speed for a plurality of thick multiple sheet bundles or a small number of sheet bundles without causing wrinkles or scratches on the sheet bundle. The device will be provided.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a copying machine including a sheet post-processing device of the present invention.

FIG. 2 is a sectional view of a sheet post-processing device.

FIG. 3 is a block diagram showing the basics of a control system.

FIG. 4 is a sectional view of a sheet receiving portion and a sheet discharging portion.

FIG. 5 is a plan view of a sheet discharging portion, a sectional view taken along line AA, and B.
-B sectional drawing.

FIG. 6 is a perspective view of a stapler and a sheet delivery unit.

FIG. 7 is a front view of a sheet delivery means.

FIG. 8 is a plan view of a sheet passing means.

FIG. 9 is a cross-sectional view of a sheet discharging unit.

FIG. 10 is a flowchart of a sheet post-processing process.

FIG. 11 is a configuration diagram showing a sensor arrangement and sheet discharge tray movement of the sheet post-processing apparatus.

FIG. 12 is a load current characteristic diagram of a sheet transfer unit driving motor.

FIG. 13 is a timing chart of a sheet discharging operation (first
Example).

FIG. 14 is a timing chart of the sheet discharge operation (second
Example).

FIG. 15 is a timing chart of the sheet discharging operation (third part)
Example).

[Explanation of symbols]

100 Copier body 400 Sheet post-processing device (FNS device, finisher) 420 (430) Second (third) transport path 422,432 Guide belt 425 (435) First (second) discharge belt 426 (436) First (Second) Tray (intermediate stacker) 427 (437) Aligning means 4274 Movable aligning plate 440,450 Sheet transfer section 441,451 Stopper 442 Transfer lever 443 Paper pressing lever 460,470 Paper discharging means M3 Discharge belt driving motor M5 sheet Stepping motor for delivery and paper pressing drive P sheet (recording paper), sheet bundle S1, S6, S11, S42, S43 paper passage sensor S16, S18 paper pressing position detection sensor ST1 first stapler (stitching means) ST2 second stapler (Binding means) T1 first paper ejection tray (upper tray) T2 second paper ejection tray (lower tray)

Claims (3)

[Claims] 1. A stacker for introducing and stacking a plurality of sheets of various sizes discharged from an image forming apparatus for temporary storage, a stopper member for aligning the leading end portions of the plurality of sheets in the transport direction, and the plurality of sheets. Aligning means for aligning the sheets in a direction orthogonal to the conveying direction, stapling means for binding the bundle of sheets stacked and aligned on the stacker, and a rotatable discharge belt for transferring and discharging the bound sheet bundle. And a discharge tray for storing the sheet bundle discharged by the discharge belt, in a sheet post-processing apparatus, which delivers the sheet bundle stacked, aligned, aligned and bound on the stacker to the discharge belt. Means, driving means for changing the discharge linear velocity of the discharge belt to a plurality of stages, and before feeding the sheet bundle to the discharge belt side. Detection means for detecting a load current value of a drive source for movably driving the transfer means, and the number of sheet bundles to be sent to the discharge belt from the load current value detected by the detection means to detect the number of sheet bundles. According to the control means for variable speed control of the driving means, the linear speed of the discharge belt is controlled by the control means and the driving means when the load current value is larger than a preset number of sheets. A sheet post-processing apparatus characterized by: 2. A stacker for introducing and stacking a plurality of sheets of various sizes discharged from an image forming apparatus for temporary storage, a stopper member for aligning the leading end portions of the plurality of sheets in the transport direction, and the plurality of sheets. Aligning means for aligning the sheets in a direction orthogonal to the conveying direction, stapling means for binding the bundle of sheets stacked and aligned on the stacker, and a rotatable discharge belt for transferring and discharging the bound sheet bundle. And a sheet post-processing device including a sheet discharge tray that stores the sheet bundle discharged by the discharge belt, and a movable sheet pressing unit that presses the sheet bundle before the binding process by the stapling unit. Detecting means for detecting the thickness of the sheet bundle by detecting the moving range of the paper pressing means, and the discharging linear velocity of the discharging belt can be changed in a plurality of steps. And a control means that controls the driving means at a variable speed according to the number of sheet bundles detected by the detection means, and the number of sheet bundles is predetermined. When the number of sheets is larger than the number of sheets, the sheet post-processing apparatus is characterized in that the linear speed of the discharge belt is controlled to be decelerated by the control means and the driving means. 3. A stacker for introducing and stacking a plurality of sheets of various sizes discharged from an image forming apparatus for temporary storage, a stopper member for aligning the leading ends of the plurality of sheets in the transport direction, and the plurality of sheets. Aligning means for aligning the sheets in a direction orthogonal to the conveying direction, stapling means for binding the bundle of sheets stacked and aligned on the stacker, and a rotatable discharge belt for transferring and discharging the bound sheet bundle. And a sheet post-processing apparatus including a sheet ejection tray that stores a sheet bundle ejected by the ejection belt, and a passage sensor that detects passage of a sheet that is unloaded from the image forming apparatus and introduced into the stacker, Measuring means for measuring a conveying time from the passage of the first sheet of the bundle of sheets detected by the passage sensor to the passage of the final sheet; The driving means for changing the discharging linear velocity of the discharging belt in a plurality of stages and the control means for controlling the driving speed of the driving means in accordance with the conveying time of one sheet bundle detected by the measuring means. A sheet post-processing device configured to decelerate the linear velocity of the discharge belt by the control unit and the driving unit when the transport time of the sheet bundle is more than a predetermined number.